JP2007262332A - Ink composition, method for inkjet-recording, printed matter, method for producing printing plate for lithography, and printing plate for lithography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition cured by irradiating radioactive rays with high sensitivity thereto to thereby form an image having high quality which can have satisfactory adhesion and a method for inkjet-recording using the ink composition, and to provide further a printed matter obtained using the ink composition curable by irradiating radioactive rays with high sensitivity thereto, a printing plate for a lithography and a method for producing the printing plate for a lithography. <P>SOLUTION: This ink composition contains a compound represented by General Formula (I): wherein R represents a coupling group having an atomic number of 4 or more. <P>COPYRIGHT: (C)2008,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 composition, and a method for producing the lithographic printing plate. It is.

  Cyclic ether compounds such as three-membered rings and four-membered rings are known to exhibit high reactivity, and the polymerizability contained in curable compositions to which photocationic polymerization or thermal polymerization using acid anhydrides is applied. It is used as a compound (see, for example, Patent Documents 1 and 2).

On the other hand, 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 melt type thermal transfer method, an ink jet method and the like. In particular, the ink jet method can be implemented with an inexpensive apparatus, and the ink can be used efficiently because the image is directly formed on the recording medium by ejecting the ink only to the required image portion. Cost is low. Furthermore, there is little noise and it is excellent as an image recording method.
According to the inkjet system, printing is possible not only on plain paper but also on non-water-absorbing recording media such as plastic sheets and metal plates. However, high speed and high image quality are important issues for printing. The time required for drying and curing the droplets after printing has a property of greatly affecting the productivity of printed matter and the sharpness of the printed image.

As one of the ink jet methods, there is a recording method using an ink for ink jet recording that can be cured by irradiation of radiation. According to this method, the productivity of printing can be improved and a sharp image can be formed by irradiating the ink immediately after ink ejection or after a certain time and curing the ink droplets.
By achieving high sensitivity of ink for ink jet recording that can be cured by irradiation with radiation such as ultraviolet rays, high curability is imparted to radiation, improving productivity of ink jet recording, reducing power consumption, and applying to radiation generators. There are many benefits such as longer life by reducing the load and prevention of volatilization of low molecular weight materials due to insufficient curing. In addition, high sensitivity improves the strength of the image formed by the ink for ink jet recording, particularly when applied to the formation of a lithographic printing plate. Will be obtained.

  Such a curable ink jet method using radiation, for example, ultraviolet rays has been attracting attention in recent years because it has a relatively low odor, and can be recorded on a recording medium having no quick drying and no ink absorption. An ultraviolet ray curable ink composition for inkjet that is used is disclosed (for example, see Patent Documents 3 to 7). Further, even for a support that is usually difficult to directly record with an ink jet recording method, an image having no bleeding, high sensitivity, high adhesion to a recording medium can be recorded, and skin irritation or For the purpose of providing an inkjet recording ink with low sensitization and high safety, a composition containing a polymerizable compound consisting of a specific radical polymerization type acrylate compound group and a coloring material has been proposed ( For example, see Patent Documents 8 and 9). Although these radical polymerization type inks are excellent in curing speed and can form images without bleeding, they have a problem that adhesion to a recording medium is reduced due to volume shrinkage during curing.

For this reason, for the purpose of improving the adhesion to a recording medium, a cationic polymerization type ink composition having a small shrinkage rate upon UV curing has been proposed (for example, see Patent Document 10). However, these cationic polymerization type inks are not sufficiently stable at the time of storage due to a reaction based on an acid generated with the passage of time, which has been a major obstacle to practical use. For this reason, as an attempt to improve the storage stability, a technique of adding a basic compound or a thermal base generator has been proposed (for example, see Patent Documents 11 to 13). It has been found that a new problem arises that the curing sensitivity of the ink is lowered due to the inhibition of the function of the ink.
In addition, the polyfunctional cyclic ether used for the purpose of improving the sensitivity of the cationic polymerization type ink has a three-dimensional structure in which the polymer obtained by curing is highly crosslinked, so that the flexibility of the film after ink curing is reduced, On the recording medium, cracks and peeling easily occur, and there is a problem in durability of the formed image.

As described above, a UV curable ink composition having a high sensitivity to radiation irradiation and a high strength film-forming property has not yet been provided.
Japanese Patent Laid-Open No. 11-43540 Japanese Patent Laid-Open No. 11-60702 JP-A-63-235382 JP-A-3-216379 Japanese Patent Laid-Open No. 5-214280 Japanese Patent Publication No.6-212256 Japanese Patent Publication No. 6-62905 JP 2003-192943 A JP 2003-192944 A Japanese Patent Laid-Open No. 9-183928 JP 2003-312121 A JP 2003-341217 A JP 2004-91558 A

An object of the present invention is to cure with high sensitivity to radiation irradiation and form a high-quality image. Further, the image formed by curing has sufficient adhesion to a recording medium. An ink composition and an ink jet recording method using the ink composition are provided.
A further object of the present invention is to provide a printed matter, a lithographic printing plate, and a method for producing the lithographic printing plate obtained using an ink composition that can be cured with high sensitivity by irradiation with radiation.

Means for solving the above problems are as follows. That is,
<1> An ink composition comprising a compound represented by the following general formula (I) (hereinafter appropriately referred to as “specific polymerizable compound”).

式中、Ｒは主骨格を構成する原子数が４以上の連結基を表す。
＜２＞ 着色剤を含有する＜１＞に記載のインク組成物である。
＜３＞ インクジェット記録用である＜１＞又は＜２＞に記載のインク組成物である。
＜４＞ 被記録媒体上に、＜１＞乃至＜３＞のいずれか１つに記載のインク組成物をインクジェット記録装置により吐出する工程、及び、吐出されたインク組成物に活性放射線を照射して、該インク組成物を硬化する工程、を含むインクジェット記録方法である。
＜５＞ 前記活性放射線が、発光ピーク波長が３５０〜４２０ｎｍの範囲にあり、且つ、被記録媒体表面での最高照度が１０〜２，０００ｍＷ／ｃｍ²となる紫外線を発生する発光ダイオードにより照射される紫外線である＜４＞に記載のインクジェット記録方法である。
＜６＞ ＜４＞又は＜５＞に記載のインクジェット記録方法によって記録された印刷物である。
＜７＞ 支持体上に、＜１＞乃至＜３＞のいずれか１つに記載のインク組成物を吐出する工程、及び、吐出されたインク組成物に活性放射線を照射して、該インク組成物を硬化させることにより、当該インク組成物が硬化してなる疎水性画像を前記支持体上に形成する工程、を含む平版印刷版の製造方法である。
＜８＞ ＜７＞に記載の平版印刷版の製造方法によって製造された平版印刷版である。

In the formula, R represents a linking group having 4 or more atoms constituting the main skeleton.
<2> The ink composition according to <1>, which contains a colorant.
<3> The ink composition according to <1> or <2>, which is for inkjet recording.
<4> A step of ejecting the ink composition according to any one of <1> to <3> onto a recording medium using an ink jet recording apparatus, and irradiating the ejected ink composition with active radiation. And a step of curing the ink composition.
<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>, wherein the ultraviolet ray is ultraviolet light.
<6> A printed matter recorded by the inkjet recording method according to <4> or <5>.
<7> A step of discharging the ink composition according to any one of <1> to <3> on a support, and irradiating the discharged ink composition with actinic radiation to thereby form the ink composition A method for producing a lithographic printing plate comprising a step of curing a product to form a hydrophobic image formed by curing the ink composition on the support.
<8> A lithographic printing plate produced by the method for producing a lithographic printing plate according to <7>.

The curable composition of the present invention is useful as an optical modeling material for resists, color filters, optical disks, and the like, in addition to ink compositions such as UV curable inks, paints, and adhesives.
In particular, the ink composition of the present invention can be suitably used as an ink composition for inkjet recording, and can be cured with high sensitivity by radiation such as ultraviolet rays to form a high-quality image.
The specific polymerizable compound in the present invention has a long distance between cross-linking points due to the presence of a long-chain linking group, and also has a high degree of freedom of rotation of the linking group, so that the formed cured film is excellent in flexibility.
In addition, by applying an ink jet recording method, even when an ink composition is ejected onto a non-absorbable recording medium, it is cured with high sensitivity and a high-strength image area is directly formed based on digital data. sell. Therefore, the ink composition of the present invention is also suitably used for preparing a lithographic printing plate, particularly a lithographic printing plate having a large area of A2 or larger, and the lithographic printing plate obtained thereby has excellent printing durability. It will be a thing.

According to the present invention, it is possible to form a high-quality image by curing with high sensitivity to radiation irradiation, and the image formed by curing has sufficient adhesion to a recording medium. An ink composition and an ink jet recording method using the ink composition are provided.
Furthermore, a further object of the present invention can provide a printed matter, a lithographic printing plate, and a method for producing a lithographic printing plate obtained using an ink composition that can be cured with high sensitivity by irradiation with radiation.

<Ink composition>
The ink composition of the invention contains a compound represented by the following general formula (I).

〔式中、Ｒは主骨格を構成する原子数が４以上の連結基を表す。〕

[Wherein R represents a linking group having 4 or more atoms constituting the main skeleton. ]

The ink composition of the present invention is a composition that can be cured by irradiation with radiation.
The “radiation” as used in the present invention is not particularly limited as long as it can impart energy capable of generating an initiation species in the composition by irradiation, and is widely α-ray, γ-ray, X-ray, Including ultraviolet rays, visible rays, electron beams, and the like. Among these, from the viewpoints of curing sensitivity and device availability, ultraviolet rays and electron beams are preferable, and ultraviolet rays are particularly preferable. Therefore, the ink composition of the present invention is preferably an ink composition that can be cured by irradiating ultraviolet rays as radiation.
The specific polymerizable compound in the present invention is preferably a compound that initiates a polymerization reaction and cures with an acid generated from a compound that generates an acid upon irradiation with radiation, which will be described later.

  A particularly preferred embodiment of the ink composition of the present invention is an ink composition comprising a specific polymerizable compound. Below, although the structure of an ink composition is demonstrated as an example, naturally this invention is not limited to this.

[Compound represented by the following general formula (I) (specific polymerizable compound)]
The specific polymerizable compound according to the present invention will be described.
The specific polymerizable compound in the present invention is a compound represented by the following general formula (I), and (A) a cyclic ether optionally having a substituent and a phenyl group are represented by (B) R. The main skeleton is connected by a linking group having 4 or more atoms.

((A) cyclic ether)
The general formula (I) representing the specific polymerizable compound contains (A) a cyclic ether as a partial structure. The cyclic ether has 3 or more ring members, and preferably 3 to 4 ring members from the viewpoint of reactivity. Moreover, it is preferable that the carbon atom number contained in cyclic ether is 2-9, and it is more preferable that a carbon atom number is 2-6. Moreover, it may be monocyclic or polycyclic.

  The cyclic ether is particularly preferably a cyclic ether shown below from the viewpoint of cationic polymerizability.

A substituent may be introduced into these cyclic ethers. Examples of the substituent that can be introduced include an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 14 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and 6 carbon atoms. -10 aryloxy group, C1-C18 alkylamino group, C6-C10 arylamino group, etc. are mentioned.
Moreover, in general formula (I), the bonding position of these cyclic ethers and the linking group (B) described below is arbitrary, and may be bonded to any carbon atom forming the ring structure.

((B) a linking group having 4 or more atoms constituting the main skeleton represented by R)
The general formula (I) representing the specific polymerizable compound includes (B) a linking group having 4 or more atoms constituting the main skeleton represented by R (hereinafter, referred to as “specific linking group” as appropriate). . This specific linking group is a divalent linking group, and from the viewpoint of flexibility, the number of atoms constituting the main skeleton of the linking group represented by R is 4 or more, and the number of atoms is 6 to 6 It is preferable that it is 20, and it is more preferable that it is 6-12. In the present invention, the “linking group having 4 or more atoms constituting the main skeleton” means an atom having 4 or more atoms used only for connecting the cyclic ether and the phenyl group in the general formula (I). Refers to a group. Examples of the specific linking group include the following, and include a linking group formed by including a linking block, and a divalent group formed by arbitrarily bonding bonds between two or more linking blocks. A linking group can be mentioned.
As a connection block, the following (L-1)-(L-23) can be mentioned, for example.

In the above formula, R ^L each independently represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a hydrogen atom, a halogen atom, a hydroxyl group, a mercapto group, or a monovalent organic group. The main skeleton can further have a hydrogen atom and a substituent. Examples of the substituent that the main skeleton may have include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxyl group, and a mercapto group.
Z ⁻ is not particularly limited as long as it is an anion corresponding to a conjugate base of an organic acid and an inorganic acid, and may be a polyvalent anion. These anions include R ^a1 —SO ₃ ⁻ , R ^a1 —SO ₂ ⁻ , R ^a1 —CO ₂ ⁻ , R ^a1 —CS ₂ ⁻ , R ^a1 —O—CS ₂ ⁻ , R ^a1 —S—CS _{2. ^{-, R a1 -O-PO 2}} -, (R a1 -O) 2 PO 2 -, R a1 (R a1 -O) PO 2 -, R a1 -EW 1 -Z - -EW 2 -R a1, ( R ^a1 ) Anions corresponding to organic acid conjugate bases such as B ⁻ , Ar ^x O ⁻ , or F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , SbF ₆ ⁻ , ClO _{4 ^{-, SO 4 2-, NO 3}} -, CO 3 2-, SCN -, CN -, SiF 6 -, FSO 3 -, I 3 -, Br 3 -, IBr 2 -, corresponding to inorganic acids conjugate base of an equal And anions. Here, R ^a1 is an organic substituent, and represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, or a group further substituted with them. They may be selected and may be combined with each other to form a ring. —EW ¹ — and —EW ² — represent an electron-withdrawing group, and specific examples thereof include —SO—, —CO—, —SO ₂ —, and the like. In addition, in R ^a1 -EW ¹ -Z ^-- EW ² -R ^a1 , when R ^a1 is absent, that is, when EW ¹ and EW ² are terminal, as specific examples of -EW ¹ and -EW ² , CN can be mentioned. -Z ^- - is ^{-C - R z1 -, - N} - - (R z1 is hydrogen atom or a substituent group). Ar ^x represents an aryl group.
In (L-1) to (L-23), the solid line represents a covalent bond, and the wavy lines of (L-8), (L-11), (L-13), and (L-16) are Represents an isomer.

A preferred embodiment of the linking block is preferably a linking group having at least one block of (L-1), more preferably at least one block of (L-1) and (L-4). And more preferably a linking group having at least two blocks of (L-1) and (L-4), most preferably of (L-1) and (L-4). It has at least two blocks, R ^{L in} (L-4) is a hydrogen atom, and the total number of blocks constituting the linking group is preferably 4 to 30, more preferably 8 to 25. 10 to 18 linking groups are preferred.

  The general formula (I) representing the specific polymerizable compound contains a phenyl group. This phenyl group may have a substituent such as an alkyl group, an alkenyl group, an alkynyl group, an aryl group or an aralkyl group, and is more preferably unsubstituted.

  The following are typical specific examples (a-1 to a-26) of the specific polymerizable compound in the present invention, but the present invention is not limited to these specific examples.

The specific polymerizable compound in the present invention can be synthesized, for example, by the following method.
(1) Raw material In accordance with Motoi's method (Motoi, et. Al., Bull. Chem. Soc. Jpn. 61, 1998), which is a dehydrohalogenation reaction, and a similar desulfonic acid reaction, a cyclic ether compound is prepared. Any raw material can be used as long as it can be produced. Specifically, a specific polymerizable compound can be produced by an etherification reaction between a cyclic ether alcohol compound represented by the following general formula (II) and a halogenated aralkyl compound or a sulfonic acid ester.

  In general formula (II), m represents an integer of 1 or more.

  More specific examples of the oxetane alcohol compound represented by the general formula (II) include 3-methyl-3-oxetanemethanol, 3-methyl-3-oxetaneethanol, 3-methyl-3-oxetanepropanol, 3- Ethyl-3-oxetanemethanol, 3-ethyl-3-oxetaneethanol, 3-ethyl-3-oxetanepropanol, 3-propyl-3-oxetanemethanol, 3-propyl-3-oxetaneethanol, 3-propyl-3-oxetane One type alone or a combination of two or more types such as propanol may be mentioned.

  More specific examples of the halogenated aralkyl compound include 1-bromo-5-phenylpentane and 1-bromo-5-phenoxypentane.

  Further, the reaction ratio between the oxetane alcohol compound represented by the general formula (II) and the halogenated aralkyl compound is not particularly limited, but per 1 mole of the oxetane alcohol compound represented by the general formula (II), It is preferable to react the halogenated aralkyl compound within a range of 0.05 to 0.6 mol. Furthermore, it is more preferable to react the halogenated aralkyl compound within a range of 0.2 to 0.5 mol per 1 mol of the oxetane alcohol compound represented by the general formula (II).

(2) Reaction temperature The reaction temperature at the time of manufacturing the oxetane compound represented by the general formula (I) will be described. The reaction temperature for reacting the two components is determined in consideration of the yield of the oxetane compound, etc., such as reactivity between raw material compounds and improvement in yield, and freedom of selection of usable organic solvent. From the viewpoint, a temperature in the range of 0 to 100 ° C is preferable, a value in the range of 10 to 90 ° C is more preferable, and a value in the range of 20 to 80 ° C is more preferable.

(3) Reaction time Next, the reaction time at the time of manufacturing the oxetane compound represented by the general formula (I) will be described. The reaction time is determined in consideration of the yield of the oxetane compound, the reaction temperature, and the like. A value is preferred. Within the range of this reaction time, the remaining unreacted raw material can be suppressed and high productivity can be achieved. The reaction time for producing the oxetane compound is more preferably a value within the range of 30 minutes to 50 hours, and even more preferably a value within the range of 1 to 10 hours.

(4) Reaction atmosphere (pH)
The reaction atmosphere (pH) when producing the oxetane compound represented by the general formula (I) will be described. The reaction atmosphere (pH value) is determined in consideration of the yield of the oxetane compound and the like, but from the viewpoint of suppression of side reactions and the freedom of selection of raw materials used, for example, a value in the range of 5 to 14 is used. Is preferred. The pH value when producing the oxetane compound is more preferably in the range of 6 to 14, and still more preferably in the range of 7 to 14. In order to adjust the pH value to a value within such a range, it is preferable to add and use an alkali such as sodium hydroxide or potassium hydroxide.

(5) Phase transfer catalyst The phase transfer catalyst used when manufacturing the oxetane compound represented by general formula (I) will be described. For the purpose of improving the reactivity between the oxetane alcohol compound and the halogenated aralkyl compound, it is preferable to add a phase transfer catalyst during the reaction. In terms of the amount of addition, reactivity, improvement in yield and other effects, and ease of purification of the obtained oxetane compound, for example, when the total amount of raw materials is 100 parts by weight, the phase transfer The addition amount of the catalyst is preferably set to a value within the range of 0.1 to 30 parts by weight. The value is more preferably in the range of 1.0 to 20.0 parts by weight per 100 parts by weight of the raw material, and further preferably in the range of 2.0 to 10.0 parts by weight.

  The type of the phase transfer catalyst is not particularly limited, but is preferably at least one compound selected from the group consisting of a quaternary ammonium salt compound and a quaternary phosphonium salt compound, for example. More specifically, tetra-n-butylammonium bromide, tetramethylammonium bromide, benzyltriethylammonium bromide, hexadecyltrimethylammonium bromide, triethylhexadecylammonium bromide, trioctylmethylammonium bromide, methyltriphenylphosphonium bromide, triethylhexa Examples include decylphosphonium bromide, tetraphenylphosphonium bromide, and tetrabutylphosphonium bromide. These may be used alone or in combination of two or more.

(6) Organic solvent The organic solvent used when manufacturing the oxetane alcohol and halogenated aralkyl compound represented by general formula (II) is demonstrated. Such an organic solvent is preferably a liquid having a boiling point of 250 ° C. or lower under atmospheric pressure from the viewpoint of being a good solvent for the raw material and facilitating production. Examples of such organic solvents include hydrocarbons such as hexane, heptane and octane, halogenated hydrocarbons such as dichloromethane and chloroform, ethers such as diethyl ether, dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran and dioxane. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate, butyl acetate, amyl acetate and γ-butyrolactone, and aromatic hydrocarbons such as benzene, toluene and xylene. May be used individually by 1 type, and may be used in combination of 2 or more type.

The structure of the compound obtained by the above production method can be confirmed by ¹ H-NMR and IR spectrum.

  In the curable composition of the present invention, the content of the specific polymerizable compound is preferably 1 to 90 mass%, more preferably 1 to 70 mass%, and more preferably 1 to 50 mass% with respect to the total solid content constituting the composition. % Is more preferable.

In the ink composition of the present invention, other polymerizable compounds (cationic polymerizable compounds) described in detail below can be used in combination with the specific polymerizable compound as long as the effects of the present invention are not impaired.
In the present invention, from the viewpoint of effectively suppressing shrinkage during curing of the composition, an epoxy compound or a specific polymerizable compound as described below as a specific polymerizable compound and another polymerizable compound. It is preferable to use a vinyl ether compound in combination with at least one compound selected from other oxetane compounds not included in the above.

[Other polymerizable compounds]
The cationically polymerizable compound that can be used in combination with 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 compound that generates an acid upon irradiation with radiation, and is cured, and is photocationically polymerizable. Various known cationic polymerizable monomers known as 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, and other oxetane compounds not included in the specific polymerizable compound described in each publication such as 220526.

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

As the alicyclic epoxide, cyclohexene oxide obtained by epoxidizing a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or peracid. Or a cyclopentene oxide containing compound is mentioned preferably.
Examples of the aliphatic epoxide include dihydric polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof. 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, diglycidyl 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 ethers of polyalkylene glycols typified by diglycidyl ethers of ethers, polypropylene glycols or alkylene oxide adducts thereof And the like. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

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

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

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

  Examples of 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, diethylene glycol monovinyl ether, and octadecyl vinyl ether.

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

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

  As other oxetane compounds that can be used in combination with the present invention, known oxetane compounds are arbitrarily selected and used as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217. it can. As the compound having an oxetane ring that can be used in combination with the specific polymerizable compound in the present invention, a compound having 1 to 4 oxetane rings in its structure is preferable. By using such a compound, it becomes easy to maintain the viscosity of the composition in a favorable range of handling properties, and when applied to an ink composition or the like, the cured composition and the recording medium High adhesion can be obtained.

  Examples of the compound having 1 to 2 oxetane rings in the molecule used in the present invention 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 is a linear or branched alkylene group, a linear or branched unsaturated hydrocarbon group, an alkylene group containing a carbonyl group or a carbonyl group, an alkylene group containing a carboxyl group, an alkylene group containing a carbamoyl group, or Represents 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: Toagosei Co., Ltd.). ), Bis (3-ethyl-3-oxetanylmethyl) ether (OXT-221: Toagosei Co., Ltd.) is exemplified.

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

In the formula (4), R ^a1 has the same ^{meaning as} in the formula (1). 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-A-2004-91556 can also be used in the present invention. The compound is described in detail in paragraphs [0022] to [0058] of the publication.
Among the other oxetane compounds used in combination with the present invention, it is preferable to use a compound having one oxetane ring from the viewpoint of the viscosity and tackiness of the composition.

  In the present invention, when the specific polymerizable compound and another cationic polymerizable compound are used in combination, the content ratio of the specific polymerizable compound and the other cationic polymerizable compound is 10: 1 to 10: 100 in terms of mass ratio. Preferably, 10: 3 to 10:80 is more preferable, and 10: 5 to 10:60 is still more preferable.

[Compounds that generate acid upon irradiation]
The curable composition and the ink composition of the present invention preferably contain a compound that generates an acid upon irradiation with radiation (hereinafter also referred to as a “photoacid generator”). In the present invention, the polymerization reaction of the polymerizable compound described above occurs due to the acid generated by the irradiation of radiation and is cured.
Examples of the photoacid generator include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, and light (400 to 200 nm) used in microresists. A compound that generates an acid upon irradiation with ultraviolet rays, far ultraviolet rays, 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. Can be appropriately selected and used.

  Examples of such a photoacid generator include an onium salt compound such as a diazonium salt, a phosphonium salt, a sulfonium salt, and an iodonium salt that decomposes upon irradiation with radiation, an imide sulfonate, an oxime sulfonate, a diazodisulfone, a disulfone, Examples thereof include sulfonate compounds such as o-nitrobenzyl sulfonate.

  Other compounds (photoacid generators) that generate an acid upon irradiation with actinic rays or radiation used in the present invention include, 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, Teh, 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. MoI. 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. PolymerSci. , 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, J.A. 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. 0290,750, 046,083, 156,535, 271,851, 0,388,343, US Patent 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 No. 0199,672, No. 84515, No. 044,115, No. 618,564, No. 0101,122, US Pat. No. 4,371 , 605, 4,431,774, JP-A 64-18143, JP-A-2-245756, JP-A-3-140109, and the like. Compounds generating an acid, disulfone compounds described in JP-A-61-1166544 and JP-A-2-71270, diazo compounds described in JP-A-3-103854, JP-A-3-103856, and JP-A-4-210960 Examples thereof include ketosulfone and diazodisulfone compounds.

  Further, a group in which an acid is generated by the light, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, 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 in 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 preferably a perfluoroalkyl group 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.

As the organic group of Rc ¹ and Rc ^{3 to} Rc ⁵ , the most preferred is 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 generally 1-30, preferably 1-20.
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, 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 for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms (for example, Methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).

Preferred examples of the cycloalkyl group represented by R ^{1c to} R ^7c include cycloalkyl groups 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.

  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 or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

Preferable examples of the photoacid generator include compounds represented by formulas (b1) to (b3).
Preferred compound examples ((b-1) to (b-96)) of (b) photoacid generator that can be used in the present invention are listed below, but the present invention is not limited thereto.

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 photo-acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the photoacid generator in the curable composition of the present invention and the ink composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% in terms of the total solid content of the composition. % By mass, more preferably 1 to 7% by mass.

[Colorant]
The ink composition of the present invention preferably contains a colorant in order to obtain a colored image.
The 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, and are selected from any known colorant such as a soluble dye. Can be used. The colorant that can be suitably used in the ink composition of the present invention 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.

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

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

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

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

As a pigment exhibiting green, C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. And azo metal complex pigments such as CI Pigment Green 8 (Nitroso Green).
As a pigment exhibiting an orange color, C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. And anthraquinone pigments such as CI Pigment Orange 51 (dichloropyrantron orange).

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

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

For dispersing the pigment, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, or a wet jet mill is used. be able to.
It is also possible to add a dispersant when dispersing the pigment. Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a high molecular weight unsaturated acid ester, a high molecular copolymer, a modified polyacrylate, an aliphatic Examples thereof include polyvalent carboxylic acids, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl phosphate esters, and pigment derivatives. It is also preferable to use a commercially available polymer dispersant such as the Solsperse series from Zeneca.
Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment.

  In the ink composition, as a dispersion medium for various components such as pigments, a solvent may be added, or a cationic polymerizable compound which is a low molecular weight component without a solvent may be used as a dispersion medium. The ink composition to which the invention is applied is a radiation curable ink, and is preferably solvent-free in order to cure the ink after it is applied to a recording medium. This is because if the solvent remains in the cured ink image, the solvent resistance is deteriorated or a VOC (Volatile Organic Compound) problem of the remaining solvent occurs. From such a viewpoint, it is preferable to use a cationically polymerizable compound as the dispersion medium, and in particular, to select a cationically polymerizable monomer having the lowest viscosity from the viewpoint of improving dispersibility and handling properties of the ink composition.

The average particle diameter of the pigment is preferably 0.02 to 0.4 μm, more preferably 0.02 to 0.1 μm, and more preferably 0.02 to 0.07 μm.
Selection of pigments, dispersants, and dispersion media, dispersion conditions, and filtration conditions are set so that the average particle diameter of the pigment particles falls within the above preferred range. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained.

(dye)
The dye that can be used in the present invention is preferably oil-soluble. Specifically, it means that the solubility in water at 25 ° C. (the mass of the dye 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, so-called water-insoluble oil-soluble dyes are preferably used.

The dye that can be used in the present invention preferably has an oil-solubilizing group introduced into the dye mother nucleus described above in order to dissolve the necessary amount in the ink composition.
As the oil-solubilizing group, long chain, branched alkyl group, long chain, branched alkoxy group, long chain, branched alkylthio group, long chain, branched alkylsulfonyl group, long chain, branched acyloxy group, long chain, branched alkoxycarbonyl group, Long chain, branched acyl group, long chain, branched acylamino group long chain, branched alkylsulfonylamino group, long chain, branched alkylaminosulfonyl group and these long chains, aryl groups containing branched substituents, aryloxy groups, aryloxycarbonyl Group, arylcarbonyloxy group, arylaminocarbonyl group, arylaminosulfonyl group, arylsulfonylamino group and the like.
In addition, for water-soluble dyes having carboxylic acid and sulfonic acid, long chain, branched alcohol, amine, phenol, aniline derivatives are used as oil-solubilizing alkoxycarbonyl groups, aryloxycarbonyl groups, alkylaminosulfonyl groups, A dye may be obtained by conversion to an arylaminosulfonyl group.

The oil-soluble dye preferably has a melting point of 200 ° C. or lower, more preferably has a melting point of 150 ° C. or lower, and still more preferably has a melting point of 100 ° C. or lower. By using an oil-soluble dye having a low melting point, the precipitation of dye crystals in the ink composition is suppressed, and the storage stability of the ink composition is improved.
Further, it is desirable that the oxidation potential is noble (high) in order to improve fading, particularly resistance to oxidizing substances such as ozone and curing characteristics. For this reason, as the oil-soluble dye used in the present invention, those having an oxidation potential of 1.0 V (vs SCE) or more are preferably used. The oxidation potential is preferably higher, the oxidation potential is more preferably 1.1 V (vs SCE) or more, and particularly preferably 1.15 V (vs SCE) or more.

As the yellow dye, a compound having a structure represented by the general formula (Y-I) described in JP-A No. 2004-250483 is preferable.
Particularly preferred dyes are dyes represented by general formulas (Y-II) to (Y-IV) described in paragraph [0034] of JP-A No. 2004-250483. And the compounds described in paragraph numbers [0060] to [0071] of JP-A-250483. The oil-soluble dye of the general formula (Y-I) described in the publication may be used not only for yellow but also for inks of any color such as black ink and red ink.

The magenta dye is preferably a compound having a structure represented by the general formulas (3) and (4) described in JP-A No. 2002-114930. Specific examples include paragraphs of JP-A No. 2002-114930. Examples include the compounds described in [0054] to [0073].
Particularly preferred dyes are azo dyes represented by the general formulas (M-1) to (M-2) described in paragraph numbers [0084] to [0122] of JP-A No. 2002-121414, and specific examples Examples thereof include compounds described in paragraph numbers [0123] to [0132] of JP-A No. 2002-121414. The oil-soluble dyes represented by the general formulas (3), (4) and (M-1) to (M-2) described in the publication are used not only for magenta but also for any color ink such as black ink and red ink. May be.

Examples of the cyan dye include dyes represented by formulas (I) to (IV) described in JP-A No. 2001-181547, and paragraphs [0063] to [0078] of JP-A No. 2002-121414. The dyes represented by the general formulas (IV-1) to (IV-4) described above are preferred, and specific examples include paragraph numbers [0052] to [0066] of JP-A No. 2001-181547. Examples thereof include the compounds described in paragraph Nos. [0079] to [0081] of Kai 2002-121414.
Particularly preferred dyes are phthalocyanine dyes represented by general formulas (CI) and (C-II) described in paragraphs [0133] to [0196] of JP-A No. 2002-121414, A phthalocyanine dye represented by formula (C-II) is preferred. Specific examples thereof include the compounds described in JP-A No. 2002-121414, paragraph numbers [0198] to [0201]. The oil-soluble dyes of the formulas (I) to (IV), (IV-1) to (IV-4), (CI) and (C-II) are not only cyan but also black ink or green ink. The ink may be used for any color ink.

  These colorants are preferably added in an amount of 1 to 20% by mass in terms of solid content in the ink composition, and more preferably 2 to 10% by mass.

  Hereinafter, various additives that can be used in the curable composition and the ink composition of the present invention as needed are described.

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

[Sensitizer]
In the present invention, a sensitizer may be added as necessary for the purpose of improving the acid generation efficiency of the photoacid generator and increasing the photosensitive wavelength.
Any sensitizer may be used as long as the photoacid generator is sensitized by an electron transfer mechanism or an energy transfer mechanism. Preferably, aromatic polycondensed compounds such as anthracene, 9,10-dialkoxyanthracene, pyrene and perylene, aromatic ketone compounds such as acetophenone, benzophenone, thioxanthone and Michlerketone, and heterocyclic compounds such as phenothiazine and N-aryloxazolidinone Is mentioned.
The addition amount is appropriately selected depending on the purpose, but is preferably 0.01 to 1 mol%, more preferably 0.1 to 0.5 mol%, based on the photoacid generator.

〔Antioxidant〕
In the present invention, an antioxidant can be added to improve the stability of the composition.
Examples of the antioxidant include European published patents, 223739, 309401, 309402, 310551, 310552, 359416, and 3435443. JP, 54-85535, 62-262417, 63-113536, 63-163351, JP-A-2-262654, JP-A-2-71262, Examples thereof include those described in Kaihei 3-121449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.
Although the addition amount is appropriately selected according to the purpose, it is preferably 0.1 to 8% by mass in terms of solid content.

[Anti-fading agent]
In the present invention, various organic and metal complex antifading agents can be used.
Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, and the like.
Examples of the metal complex-based anti-fading agent include nickel complexes and zinc complexes. No. 17643, No. VII, I to J, i. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of representative compounds described in JP-A-62-215272, pages 127 to 137 can be used. .
Although the addition amount is appropriately selected according to the purpose, it is preferably 0.1 to 8% by mass in terms of solid content.

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

〔solvent〕
In order to improve the adhesion to the recording medium, it is also effective to add a very small amount of an organic solvent to the ink composition of the present invention.
Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone, alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol, and chlorine such as chloroform and methylene chloride. Solvents, aromatic solvents such as benzene and toluene, ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, glycols such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether And ether solvents.
In this case, it is effective to add the solvent within a range that does not cause the problem of solvent resistance and VOC, and the amount is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass with respect to the whole ink composition. % Range.

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

[Surfactant]
In the present invention, a surfactant can be added.
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. An organic fluoro compound may be used in place of the surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compounds include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). No. (columns 8 to 17) and those described in JP-A Nos. 62-135826.

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

[Preferred embodiment of ink composition]
As described above, the ink composition to which the curable composition of the present invention is applied (the ink composition of the present invention) includes, as described above, a specific polymerizable compound, a compound that generates an acid upon irradiation with radiation, and other optionally contained compounds. It contains a polymerizable compound, a colorant and the like. These components are preferably 1 to 10% by mass, more preferably 2 to 8% by mass, and all polymerizable compounds including a specific polymerizable compound, preferably 1 to 10% by mass with respect to the total mass of the ink composition. 1 to 97% by mass, more preferably 30 to 95% by mass. The compound that generates an acid upon irradiation with radiation is preferably 0.01 to 20% by mass, more preferably 0.1 to 20% by mass, based on the total polymerizable compound including the specific polymerizable compound. It is suitable to contain.

  When the ink composition of the present invention is used as an ink for inkjet recording, the viscosity is preferably at a temperature at the time of ejection (for example, 40 to 80 ° C., preferably 25 to 30 ° C.) in consideration of ejection properties. It is 7-30 mPa * s, More preferably, it is 7-20 mPa * s. For example, the viscosity of the ink composition of the present invention at room temperature (25 to 30 ° C.) is preferably 35 to 500 mPa · s, more preferably 35 to 200 mPa · s. It is preferable that the composition ratio of the ink composition of the present invention is appropriately adjusted so that the viscosity is in the above range. By setting the viscosity at room temperature high, even when a porous recording medium is used, ink penetration into the recording medium can be avoided, and uncured monomers and odors can be reduced. Furthermore, it is preferable because ink bleeding at the time of ink droplet landing can be suppressed, and as a result, the image quality is improved.

  The surface tension of the ink composition of the present invention is 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.

  The ink composition of the present invention is suitably used as an inkjet recording ink. When used as an ink for ink jet recording, the ink composition is ejected onto a recording medium by an ink jet printer, and then the ejected ink composition is cured by irradiation with radiation to perform recording.

  The cured coating obtained by the ink composition of the present invention is cured by irradiation with radiation such as ultraviolet rays, and has excellent strength. Therefore, in addition to image formation, for example, an ink receiving layer (image portion) of a lithographic printing plate It can be used for various applications such as formation of.

<Inkjet recording method and printed matter>
The ink jet recording method to which the ink composition of the present invention is suitably applied (the ink jet recording method of the present invention) will be described below.
The inkjet recording method of the present invention comprises a step of ejecting the above-described ink composition of the present invention onto a recording medium (support, recording material, etc.) by an inkjet recording apparatus, and active radiation to the ejected ink composition. And a step of curing the ink composition. An image is formed on the recording medium with the cured ink composition.

The recording medium applied to the ink jet recording method of the present invention is not particularly limited, and various non-absorbing resin materials used for ordinary non-coated paper, coated paper, and so-called soft packaging, or the like. A resin film formed into a film can be used, and examples of the various plastic films include PET film, OPS film, OPP film, ONy film, PVC film, PE film, and TAC film. In addition, examples of the plastic that can be used as the recording medium material include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers. Metals and glasses can also be used as the recording medium.
In addition, the ink composition of the present invention has little heat shrinkage at the time of curing and excellent adhesion to the substrate (recording medium). Films that are easily deformed, such as heat-shrinkable PET film, OPS film, OPP film, ONy film, PVC film, etc., have the advantage that a high-definition image can be formed.
Furthermore, as one of the recording materials applicable to the present invention, there is a lithographic printing plate support described later.

Examples of the actinic radiation applied to the ink jet recording method of the present invention include α rays, γ rays, X rays, ultraviolet rays, visible rays, infrared rays, and electron beams. The peak wavelength of the actinic radiation is preferably 200 to 600 nm, more preferably 300 to 450 nm, and still 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 .
In particular, in the inkjet recording method of the present invention, irradiation with radiation generates ultraviolet rays having an emission peak wavelength of 350 to 420 nm and a maximum illuminance on the surface of the recording medium of 10 to 1,000 mW / cm ^2. Irradiation from a light emitting diode is preferred.

  In addition to the above, various conditions applied to the ink jet recording method of the present invention and details of the ink jet recording apparatus and the like are suitable applications of the ink jet recording method of the present invention. This will be described later in the plate manufacturing method.

  According to the ink jet recording method of the present invention, the dot diameter of the landed ink can be kept constant even on various supports (recording media) having different surface wettability, and the image quality can be improved. it can. In order to obtain a color image according to the present invention, 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.

Moreover, the printed matter of the present invention is an image in which an image is formed from the ink composition of the present invention by the above-described ink jet recording method (the ink jet recording method of the present invention).
Therefore, the printed matter has an image with high quality and excellent flexibility.

<Lithographic printing plate and lithographic printing plate manufacturing method>
The method for producing a lithographic printing plate of the present invention comprises a step of ejecting the ink composition of the present invention onto a support, and irradiating the ejected ink composition with actinic radiation to cure the ink composition. A process for producing a lithographic printing plate comprising a step of forming a hydrophobic image formed by curing the ink composition on the support.
The lithographic printing plate of the present invention is a lithographic printing plate produced by the above-described method for producing a lithographic printing plate of the present invention, and has a support and a hydrophobic 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 techniques for electronically processing, storing, and outputting image information using a computer have become widespread, and a new image output method corresponding to the technique 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.

As a method for obtaining a lithographic printing plate that enables such scanning exposure, a method of directly producing a lithographic printing plate with an ink composition can be mentioned. This is because the ink is ejected onto a support (preferably a hydrophilic support) by an ink jet method or the like, and this is exposed to actinic radiation, whereby a portion of the ink composition is exposed to form a desired image ( Preferably, a printing plate having a hydrophobic image is obtained. An ink composition suitable for such a system is the ink composition of the present invention.
Hereafter, each process of the manufacturing method of the lithographic printing plate of this invention is demonstrated.

[Step of discharging the ink composition of the present invention onto a support]
(Support)
The support (recording medium) used in this step is not particularly limited as long as it is a support for a lithographic printing plate, and may be a dimensionally stable plate-like support. The support is preferably a hydrophilic support. Examples of the support include paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), and plastic film (eg, cellulose diacetate, triacetic acid). Cellulose, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. . 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 mass 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 (roughening treatment for dissolving the electrochemical surface), chemical surface treatment, etc. Roughening treatment (roughening treatment that selectively dissolves the surface chemically) can be mentioned.
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 mass 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 lithographic printing plate of the present invention, the surface treatment as described above may be used as it is, and the substrate having the anodized film may be used as it is, but the adhesion with the upper layer, hydrophilicity, stain resistance, In order to further improve the heat insulation and the like, if necessary, the micropore enlargement treatment and sealing treatment of the anodized film described in JP-A-2001-253181 and JP-A-2001-322365, and hydrophilic The surface hydrophilization treatment soaked in an aqueous solution containing a functional compound can be appropriately selected and performed. 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.
Among these, a sealing treatment with an aqueous solution containing an inorganic fluorine compound, a sealing treatment with water vapor, and a sealing treatment with hot water are preferable. Each will be described below.

-Sealing treatment with aqueous solution containing 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 mass or more, and more preferably 0.05% by mass 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 mass or less, and more preferably 0.5% by mass 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. It is preferable.
The concentration of the phosphate compound in the aqueous solution is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, in terms of improvement in on-press developability and stain resistance. Moreover, it is preferable that it is 20 mass% or less at a soluble point, and it is more preferable that it is 5 mass% or less.

The ratio of each compound in the aqueous solution is not particularly limited, but the mass 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, 100 ° C. or lower, and 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 processing using the dipping method, the processing time is preferably 1 second or longer, more preferably 3 seconds or longer, 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 a 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.
The time for immersion in hot water is preferably 1 second or longer, more preferably 3 seconds or longer, 100 seconds or shorter, 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.
The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the image recording layer, good printing durability and good stain resistance are obtained, which is preferable.

  When the ink composition of the present invention is discharged onto the surface of a hydrophilic support, the ink composition is preferably heated to 40 to 80 ° C., more preferably 25 to 30 ° C., so that the viscosity of the ink composition is preferable. Is preferably discharged after being lowered to 7 to 30 mPa · s, more preferably 7 to 20 mPa · s. In particular, it is preferable to use an ink composition having an ink viscosity of 35 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, and therefore has a large viscosity fluctuation due to temperature fluctuations during ejection. The ink viscosity fluctuation has a great influence on the change of the droplet size and the change of the droplet discharge speed, and further causes the deterioration of the image quality. 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.

(Inkjet recording device)
There is no restriction | limiting in particular as an inkjet recording device used for this invention, A commercially available inkjet recording device 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 4000 × 4000 dpi, preferably 400 × 400 to 1600 × 1600 dpi, and more preferably 720 × 720 dpi. It can drive so that it can discharge with the resolution of. 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 heat energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

[Step of forming a hydrophobic image on the support by curing the ink composition by irradiating the ejected ink composition with actinic radiation]
The ink composition ejected on the surface of the support is cured by irradiation with actinic radiation. At this time, when a sensitizing dye is present together with a polymerization initiator (photoinitiator) in the ink composition, the sensitizing dye in the system absorbs actinic radiation to be in an excited state and comes into contact with the polymerization initiator. By promoting the decomposition of the polymerization initiator, a more sensitive curing reaction can be achieved.

Here, α rays, γ rays, electron beams, X rays, ultraviolet rays, visible light, infrared rays, or the like can be used as the active radiation used. The peak wavelength of the actinic radiation is, for example, 200 to 600 nm, preferably 300 to 450 nm, and more preferably 350 to 420 nm, although it depends on the absorption characteristics of the sensitizing dye. In the present invention, the polymerization initiating system has sufficient sensitivity even with low-power actinic radiation. Therefore, the output of active 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 , and still 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.

  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.

In the present invention, 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.
Preferably 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 at 50 to 800 mW / cm ² is there.

In the present invention, it is appropriate that the ink composition is irradiated with such actinic radiation for, for example, 0.01 to 120 seconds, preferably 0.1 to 90 seconds.
The contents disclosed in JP-A-60-132767 can be applied as the irradiation conditions and the basic irradiation method of actinic radiation. 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. WO99 / 54415 pamphlet discloses a method using an optical fiber and a method of irradiating a recording unit with UV light by applying a collimated light source to a mirror surface provided on the side surface of the head unit.

Thus, according to the method for producing a lithographic printing plate of the present invention, a hydrophobic image formed by curing the ink composition of the present invention by irradiation with actinic radiation can be formed on the support surface.
As described above, according to the ink composition of the present invention, it is possible to form a hydrophobic region (hydrophobic image) that is cured with high sensitivity by actinic radiation and has excellent film strength and flexibility.
For these reasons, the lithographic printing plate obtained by the lithographic printing plate production method of the present invention (lithographic printing plate of the present invention) has an image portion having high image quality and excellent flexibility, and is excellent in printing durability. .

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to these examples.

[Example 1]
<Preparation of ink>
<Yellow ink 1>
・ C. I. Pigment Yellow 13 5 parts by mass / Photocationic polymerization initiator: Triphenylsulfonium salt 6 parts by mass (UVI-6992, manufactured by Dow Chemical Company)
Sensitizing dye: 9,10-dibutoxyanthracene 3 parts by mass Polymerizable compound Monomer: 3,4-epoxycyclohexylmethyl
35 parts by weight of 3 ′, 4′-epoxycyclohexanecarboxylate
(Celoxide 2021A: manufactured by Daicel UCB)
Monomer: 3,7-bis (3-oxetanyl) -5-oxanonane
(OXT-221: manufactured by Toagosei Co., Ltd.) 21 parts by mass Monomer: 30 parts by mass of the following specific polymerizable compound (a-1)

<Magenta ink 1>
・ C. I. Pigment Red 57: 1 5 parts by mass / Photocationic polymerization initiator: Triphenylsulfonium salt 6 parts by mass (UVI-6922, manufactured by Dow Chemical Company)
Sensitizing dye: 9,10-dibutoxyanthracene 3 parts by mass Polymerizable compound Monomer: 3,4-epoxycyclohexylmethyl
35 parts by weight of 3 ′, 4′-epoxycyclohexanecarboxylate
(Celoxide 2021A: manufactured by Daicel UCB)
Monomer: 3,7-bis (3-oxetanyl) -5-oxanonane
(OXT-221: manufactured by Toagosei Co., Ltd.) 21 parts by mass Monomer: 30 parts by mass of the specific polymerizable compound (a-1)

<Cyan ink 1>
・ C. I. Pigment Blue 15: 3 5 parts by mass / Photocationic polymerization initiator: Triphenylsulfonium salt 6 parts by mass
(UVI-6992, manufactured by Dow Chemical Company)
Sensitizing dye: 9,10-dibutoxyanthracene 3 parts by mass Polymerizable compound Monomer: 3,4-epoxycyclohexylmethyl
35 parts by weight of 3 ′, 4′-epoxycyclohexanecarboxylate
(Celoxide 2021A: manufactured by Daicel UCB)
Monomer: 3,7-bis (3-oxetanyl) -5-oxanonane
(OXT-221: manufactured by Toagosei Co., Ltd.) 21 parts by mass Monomer: 30 parts by mass of the specific polymerizable compound (a-1)

<Black ink 1>
・ C. I. Pigment Black 7 5 parts by mass / Photocationic polymerization initiator: Triphenylsulfonium salt 6 parts by mass
(UVI-6992, manufactured by Dow Chemical Company)
Sensitizing dye: 9,10-dibutoxyanthracene 3 parts by mass Polymerizable compound Monomer: 3,4-epoxycyclohexylmethyl
35 parts by weight of 3 ′, 4′-epoxycyclohexanecarboxylate
(Celoxide 2021A: manufactured by Daicel UCB)
Monomer: 3,7-bis (3-oxetanyl) -5-oxanonane
(OXT-221: manufactured by Toagosei Co., Ltd.) 21 parts by mass Monomer: 30 parts by mass of the specific polymerizable compound (a-1)

  The crude color inks 1 prepared as described above were filtered with a filter having an absolute filtration accuracy of 2 μm to obtain inks 1 of the respective colors.

<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 necessary for curing was irradiated. In the present invention, dpi represents the number of dots per 2.54 cm.

<Formation and evaluation of color image>
Using each color ink prepared above, black, cyan, magenta, and yellow were emitted in this order 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. The exposure was performed at a total exposure energy of 100 mJ / cm ² uniformly for each color as energy for complete curing so that the tackiness disappeared by palpation. As the recording medium, a grained aluminum support, a transparent biaxially oriented polypropylene film with printability and a surface-treated transparent biaxially stretched polypropylene film, a soft vinyl chloride sheet, cast coated paper, and commercially available recycled paper are used. As a result, it was found that all of them were high-resolution images without dot bleeding. Further, even when high-quality paper was used, the ink did not turn around and the ink was sufficiently cured, and there was almost no odor due to unreacted monomers. Further, the image 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 cellophane (registered trademark).

[Example 2]
<Magenta ink 2>
In the magenta ink 1 prepared in Example 1, among the monomers used as the polymerizable compound, 30 parts by mass of the specific polymerizable compound (a-1) is changed to 30 parts by mass of the following specific polymerizable compound (a-22). A magenta ink 2 was prepared in the same manner as the magenta ink 1 except that it was changed.

[Example 3]
<Magenta ink 3>
In the magenta ink 1 prepared in Example 1, among the monomers used as the polymerizable compound, 30 parts by mass of the specific polymerizable compound (a-1) is changed to 30 parts by mass of the following specific polymerizable compound (a-25). A magenta ink 3 was prepared in the same manner as the magenta ink 1 except that it was changed.

[Example 4]
<Magenta ink 4>
In the magenta ink 1 prepared in Example 1, among the monomers used as the polymerizable compound, 30 parts by mass of the specific polymerizable compound (a-1) was changed to 30 parts by mass of the following specific polymerizable compound (a-10). A magenta ink 4 was prepared in the same manner as the magenta ink 1 except that it was changed.

[Example 5]
<Magenta ink 5>
In magenta ink 1 prepared in Example 1, 3 parts by mass of “9,10-dibutoxyanthracene” used as the sensitizing dye was changed to 3 parts by mass of “Darocur ITX (manufactured by Ciba Specialty Chemicals)”. A magenta ink 5 was prepared in the same manner as the magenta ink 1.

[Example 6]
<Magenta ink 6>
5 parts by mass of “CI Pigment Red 57: 1” used in magenta ink 1 prepared in Example 1 was changed to 5 parts by mass of “oil-soluble dye M-1 oxidation potential + 1.37 V” shown below. A magenta ink 6 was prepared in the same manner as the magenta ink 1 except for the above.

[Example 7]
<Magenta ink 7>
5 parts by mass of “CI Pigment Red 57: 1” used in the magenta ink 1 prepared in Example 1 was changed to 5 parts by mass of “oil-soluble dye M-2 (oxidation potential +0.94 V)” shown below. A magenta ink 7 was prepared in the same manner as the magenta ink 1 except that it was changed.

[Comparative Example 1]
<Magenta ink 8>
In the magenta ink 1 prepared in Example 1, among the monomers used as the polymerizable compound, 30 parts by mass of the specific polymerizable compound (a-1) was changed except that the following comparative compound 1 was changed to 30 parts by mass. Magenta ink 8 was adjusted in the same manner as magenta ink 1.

[Comparative Example 2]
<Magenta ink 9>
In the magenta ink 1 prepared in Example 1, among the monomers used as the polymerizable compound, the magenta ink 1 was changed except that 30 parts by mass of the compound (a-1) was changed to 30 parts by mass of the following comparative compound 2. In the same manner as described above, magenta ink 9 was prepared.

  The crude magenta inks 2 to 9 prepared in the above Examples 2 to 7, Comparative Example 1 and Comparative Example 2 were respectively filtered through a filter having an absolute filtration accuracy of 2 μm to obtain magenta inks 2 to 9.

  In the ink compositions prepared in the above examples and comparative examples, the ink viscosity at the ink discharge temperature was in the range of 7 to 20 mPa · s.

<Inkjet image recording>
Using the magenta inks 2 to 9 of Examples 2 to 7 and Comparative Examples 1 and 2 prepared as described above and the magenta ink 1 prepared in Example 1, the same method as described in Example 1 was used. A magenta image was produced.

<Evaluation of inkjet image>
Each formed image was evaluated for adhesion to a polystyrene substrate according to the method described below.

(Adhesion)
The adhesion to the polystyrene plate was evaluated by a cross hatch test (EN ISO 2409). This test is better as the value is larger, and 3B or more is evaluated as having no practical problem.

As can be seen from Table 1, it can be seen that the ink compositions (magenta inks 1 to 7) of the present invention are excellent in the flexibility of an image having good adhesion.
On the other hand, it can be seen that the magenta ink 8 and the magenta ink 9 of Comparative Example 1 and Comparative Example 2 are inferior in adhesion.

[Example 8: Image formation by light emitting diode (LED)]
Inkjet image in the same manner as in Example 1 except that the magenta ink 1 prepared in Example 1 was used and an ultraviolet light-emitting diode (UV-LED) was used instead of the metal halide lamp Vzero085 manufactured by Integration Technology. Recorded.
In this embodiment, NCCU033 manufactured by Nichia Corporation 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 is obtained on the surface of the recording medium. The exposure time after droplet ejection and the exposure time can be changed depending on the conveyance speed of the recording medium and the distance between the head and the LED in the conveyance direction. In this embodiment, the exposure is performed about 0.5 seconds after landing.
The exposure energy on the recording medium can be adjusted between 0.01 and 15 J / cm ² according to the setting of the distance to the medium and the conveyance speed.

[Comparative Example 3: Image formation by light emitting diode (LED)]
Ink jet image recording was performed in the same manner as in Example 8, except that in Example 8, magenta ink 8 prepared in Comparative Example 1 was used instead of magenta ink 1.

<Evaluation of inkjet image>
For the inks of Example 8 and Comparative Example 3, the adhesion and sensitivity were measured according to the methods described above.

(sensitivity)
Sensitivity was defined as the exposure energy (mJ / cm ² ) at which the sticky feeling disappeared in the image image after ultraviolet irradiation. The smaller the value, the higher the sensitivity.

Further, the flexibility of the image formed with the ink of Example 8 or Comparative Example 3 was evaluated according to the above method.
The evaluation results are shown in Table 2.

As is apparent from Table 2, it can be seen that the ink composition of the present invention (magenta ink 10) is highly sensitive to ultraviolet light-emitting diodes and has excellent adhesion to the obtained image.
Further, when the ultraviolet lamp shown in Table 1 is used and the ultraviolet light emitting diode shown in Table 2 is compared, the ultraviolet light emitting diode is more sensitive to radiation. I know that there is.

Example 9
-Production of support-
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.025 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: It contains 0.03% by mass, and the balance is prepared using Al and an inevitable impurity aluminum alloy. After the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is obtained by DC casting Produced. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing using a continuous annealing machine at 500 degreeC, it finished by cold rolling to 0.24 mm in thickness, and obtained the aluminum plate of JIS1050 material. The obtained aluminum had an average crystal grain size with a minor axis of 50 μm and a major axis of 300 μm. After making this aluminum plate into width 1030mm, it used for the surface treatment shown below and created the aluminum support body.

-Surface treatment-
In the surface treatment, the following various treatments (a) to (j) were continuously performed. In addition, after each process and water washing, the liquid was drained with the nip roller.
(A) Mechanical surface roughening treatment While supplying a suspension of a polishing agent (pumice) having a specific gravity of 1.12 and water as a polishing slurry liquid to the surface of the aluminum plate, mechanical roughening is performed by a rotating nylon brush. Surface treatment was performed. The average particle size of the abrasive was 30 μm, and the maximum particle size was 100 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 45 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.
(B) Alkali etching treatment The aluminum plate obtained above was subjected to an etching treatment by spraying using an aqueous solution having a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass and a temperature of 70 ° C. / M ² dissolved. Then, water washing by spraying was performed.
(C) Desmutting treatment The desmutting treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. AC power supply waveform is 0.8 msec until the current value reaches the peak from zero, duty ratio is 1: 1, and trapezoidal rectangular wave alternating current is used to perform electrochemical surface roughening treatment with the carbon electrode as the counter electrode. went. Ferrite was used for the auxiliary anode.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.
(E) Alkaline etching treatment The aluminum plate was subjected to etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.50 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.
(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used in the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in the nitric acid aqueous solution.

(G) Electrochemical roughening treatment An electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 5.0 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform is subjected to electrochemical surface roughening using a carbon electrode as a counter electrode, using a trapezoidal trapezoidal wave alternating current with a time until the current value reaches a peak from zero for 0.8 msec, a duty ratio of 1: 1. went. Ferrite was used for the auxiliary anode.
The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. Then, water washing by spraying was performed.
(H) Alkaline etching treatment The aluminum plate was subjected to an etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.12 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.
(I) Desmutting treatment A desmutting treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.
(J) Anodizing treatment Anodizing treatment is performed using an anodizing apparatus (first and second electrolysis section length 6 m, first and second feeding section length 3 m, first and second feeding section length 2.4 m each). It was. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 50 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 20 ° C. Then, water washing by spraying was performed. The final oxide film amount was 2.7 g / m ² .

(Preparation and evaluation of lithographic printing plates)
On the aluminum support produced above, printing was performed with the ink composition (magenta) of Example 1, and an image was formed and cured in the same manner as in Example 1.
Using this as a lithographic printing plate, image evaluation and printing durability evaluation were performed by the following methods.

a. Evaluation of Image A lithographic printing plate produced using the ink composition of Example 1 was applied to a Heidel KOR-D machine, and dampened with ink [VALUES-G Beni for Sheetfed (Dainippon Ink Co., Ltd.)]. Water [Ecocity 2 (Fuji Photo Film Co., Ltd.)] was supplied for printing. The printed matter after printing 100 sheets was visually evaluated. As a result, it was confirmed that the image was a good image with no white spots in the image area and no stain in the non-image area.
b. Evaluation of printing durability When printing is continued as it is, 10,000 or more high-quality prints free from white spots in the image area and stains in the non-image area are obtained, and the printing durability is at a level where there is no practical problem. I confirmed that there was.

Claims (8)

An ink composition comprising a compound represented by the following general formula (I):

[Wherein R represents a linking group having 4 or more atoms constituting the main skeleton. ]   The ink composition according to claim 1, comprising a colorant.   The ink composition according to claim 1 or 2, which is for inkjet recording. A step of ejecting the ink composition according to any one of claims 1 to 3 on a recording medium by an ink jet recording apparatus; and
An ink jet recording method comprising: a step of irradiating the ejected ink composition with active radiation to cure the ink composition. The actinic 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 inkjet recording method according to claim 4.   A printed matter recorded by the inkjet recording method according to claim 4. A step of discharging the ink composition according to any one of claims 1 to 3 on a support; and
Irradiating the discharged ink composition with actinic radiation to cure the ink composition, thereby forming a hydrophobic image on the support 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.