JP2007177057A - Ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition that is excellent in flexibility of a cured film and adhesion to a recording medium, forms an image of high image quality and has good preservation stability, an inkjet recording method using the ink composition and printed matter obtained by the inkjet recording method, and to provide a lithographic printing plate exhibiting high printing durability obtained using the ink composition, and a manufacturing method thereof. <P>SOLUTION: The ink composition comprises (a) 0.01-4.5 mass%, based on the whole amount of the ink composition, of a polymerizable compound represented by general formula (I), (b) a polymerizable compound other than (a), (c) a polymerization initiator and (d) a colorant. In the formula, X is a substituent group selected from among a bromine atom, substituted peroxy group, mercapto group, substituted thio group and substituted sulfonyl group; Y is -CN or -COZ; and Z is a group linked to the carbonyl group via a heteroatom, or a halogen atom. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention provides an ink composition, particularly a radiation curable ink jet recording ink, which is excellent in flexibility of a cured film and adhesion to a recording medium, can form a high quality image, and has good storage stability. The present invention relates to a composition, an inkjet recording method using the composition, and a printed material. The present invention also relates to a lithographic printing plate that requires no development processing, has high printing durability, and can form a high-quality image, and a method for producing the same.

  As an image recording method for forming an image on a support such as paper based on an image data signal, there are an electrophotographic method, a sublimation type and a melt type thermal transfer method, an ink jet method and the like. In particular, the ink jet method can be implemented with an inexpensive apparatus, and ink is ejected only to the required image area on the support to form an image directly, so that the ink can be used efficiently and the running cost is reduced. Is cheap. Furthermore, it is excellent in that the apparatus is simple and noise is low.

As one of such ink jet type image recording methods, there is a method of fixing ink on a support using an ink that is cured by irradiation with radiation such as ultraviolet rays. Ink-jet recording inks that can be cured by irradiation with radiation such as ultraviolet rays, which are used in this method, have a relatively low odor, are quick-drying, have no ink absorbability, and are usually difficult to directly record. (For example, it is known that there is a feature that an image having no blur, high sensitivity, and high adhesion can be obtained with respect to (for example, a plastic sheet or a metal plate) (for example, Patent Documents 1 to 5). reference.).
In addition to the above characteristics, for the purpose of providing an ink for inkjet recording that has low irritation and sensitization even when applied to the skin and is highly safe, it is colored with a polymerizable compound comprising a specific radical polymerization type acrylate compound group. A composition containing an agent has been proposed (see, for example, Patent Documents 6 and 7).

When such a radiation curable ink for ink jet recording is employed, adhesion of an image formed by a fixed ink to a support, flexibility of a cured film, and high image quality are required.
Furthermore, it is necessary to provide a stable printed image in any storage environment after printing (for example, bending of printed matter).

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

An object of the present invention is to solve the conventional problems and achieve the following objects.
That is, an object of the present invention is to provide an ink composition that can form a high-quality image with excellent adhesion to a recording medium and flexibility of a cured film by irradiation of radiation, and has good storage stability. Another object of the present invention is to provide an ink jet recording method using the ink composition, and a printed matter obtained by the ink jet recording method.
Another object of the present invention is to provide a high printing durability lithographic printing plate obtained by using the ink composition and a method for producing the same.

As a result of intensive studies, the present inventors have found that the above object can be achieved by using a limited amount of a specific polymerizable compound, and have completed the present invention.
That is, the present invention is as follows.

(1) (a) 0.01 to 4.5% by mass of at least one polymerizable compound represented by the following general formula (I) with respect to the total ink composition amount, (b) Polymerizability other than (a) An ink composition comprising a compound, (c) a polymerization initiator, and (d) a colorant.

式中、Ｒ^a、Ｒ^bは各々独立して、水素原子、ハロゲン原子、シアノ基、炭化水素基、置換オキシ基、置換チオ基、置換アミノ基、置換カルボニル基、又はカルボキシラート基を表し、Ｘは臭素原子、置換パーオキシ基、メルカプト基、置換チオ基、置換スルホニル基から選ばれる置換基を表す。Ｙは-ＣＮまたは-ＣＯＺを表し、Ｚはヘテロ原子を介してカルボニル基に結合している基またはハロゲン原子を表す。

In the formula, R ^a and R ^b each independently represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a substituted oxy group, a substituted thio group, a substituted amino group, a substituted carbonyl group, or a carboxylate group, X represents a substituent selected from a bromine atom, a substituted peroxy group, a mercapto group, a substituted thio group, and a substituted sulfonyl group. Y represents —CN or —COZ, and Z represents a group bonded to the carbonyl group via a hetero atom or a halogen atom.

(2) The ink composition according to (1), which is for inkjet recording.
(3) The method includes the steps of ejecting and landing the ink composition according to the above (1) or (2) on a recording medium, and curing the ink composition by irradiating with radiation. Inkjet recording method.
(4) A printed matter obtained by ejecting and landing the ink composition described in (1) or (2) on a recording medium, and then irradiating the ink composition to cure the ink composition.
(5) The ink composition described in the above (1) or (2) is jetted onto a hydrophilic support, landed, and then irradiated with radiation to cure the ink, thereby forming a hydrophobic region. A method for producing a lithographic printing plate characterized by the above.
(6) A hydrophobicity formed by ejecting the ink composition according to the above (1) or (2) on a hydrophilic support, landing the ink composition, and then irradiating the ink composition to cure the ink composition. A lithographic printing plate having a sex region.

According to the present invention, it is possible to form a high-quality image excellent in adhesion to a recording medium and flexibility of a cured film with respect to irradiation of radiation, and having good storage stability, An ink jet recording method using the ink composition and a printed matter obtained by the ink jet recording method can be provided.
Further, according to the present invention, by using the ink composition of the present invention, a lithographic printing plate having a high-strength and high-quality image area based on digital data and excellent in printing durability, and a method for producing the same are provided. can do.

式中、Ｒ^a、Ｒ^bは各々独立して、水素原子、ハロゲン原子、シアノ基、炭化水素基、置換オキシ基、置換チオ基、置換アミノ基、置換カルボニル基、又はカルボキシラート基を表し、Ｘは臭素原子、置換パーオキシ基、メルカプト基、置換チオ基、置換スルホニル基から選ばれる置換基を表す。Ｙは-ＣＮまたは-ＣＯＺを表し、Ｚはヘテロ原子を介してカルボニル基に結合している基またはハロゲン原子を表す。 (1) Ink composition The ink composition of the present invention comprises (a) 0.01 to 4.5% by mass of at least one polymerizable compound represented by the following formula (I) based on the total amount of the ink composition, (B) It contains a polymerizable compound other than (a), (c) a polymerization initiator, and (d) a colorant.

In the formula, R ^a and R ^b each independently represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a substituted oxy group, a substituted thio group, a substituted amino group, a substituted carbonyl group, or a carboxylate group, X represents a substituent selected from a bromine atom, a substituted peroxy group, a mercapto group, a substituted thio group, and a substituted sulfonyl group. Y represents —CN or —COZ, and Z represents a group bonded to the carbonyl group via a hetero atom or a halogen atom.

Here, the ink composition of the present invention is cured by applying energy capable of generating active species from (c) a polymerization initiator. This energy is preferably actinic radiation, and the actinic radiation widely includes α rays, γ rays, X rays, ultraviolet rays, visible rays, infrared rays, electron rays, etc. From the viewpoint 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 active radiation.
Hereinafter, each component used in the ink composition of the present invention will be described in order.

[(A) Specific polymerizable compound]
The polymerizable compound constituting the ink composition of the present invention is a specific polymerizable compound (also referred to as α-heteromethacrylic compound) represented by the formula (I). This compound is used for adhesion of a cured film and imparting flexibility.
By using this specific α-heteromethacrylic compound, in the radical polymerization system, hydrogen is donated to the radical generated at the time of polymerization, so that the curing rate can be controlled. Therefore, the molecular weight increase at the time of hardening can be suppressed and the cured film excellent in adhesiveness and a softness | flexibility can be formed.

In the formula, R ^a and R ^b each independently represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a substituted oxy group, a substituted thio group, a substituted amino group, a substituted carbonyl group, or a carboxylate group, X represents a substituent selected from a bromine atom, a substituted peroxy group, a mercapto group, a substituted thio group, and a substituted sulfonyl group. Y represents —CN or —COZ, and Z represents a group bonded to the carbonyl group via a hetero atom or a halogen atom.

Next, the specific α-heteromethacrylic compound represented by the general formula (I) will be described in detail. Examples of the hydrocarbon group for R ^a and R ^b include an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group.

Examples of the alkyl group include linear, branched, or cyclic alkyl groups having 1 to 20 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and pentyl. Group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group , Isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group and 2-norbornyl group.
Of these, linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 3 to 12 carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are more preferable.

  Examples of the aryl group include those in which 1 to 3 benzene rings form a condensed ring, and those in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Specific examples include a phenyl group, naphthyl Group, anthryl group, phenanthryl group, indenyl group, acenabutenyl group, fluorenyl group can be mentioned, and among these, a phenyl group and a naphthyl group are more preferable.

Examples of the alkenyl group include vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl, 2-buteinyl and the like.
Examples of the alkynyl group include ethynyl, 2-propynyl, 2-butynyl and the like.

  Examples of the substituent in the substituted alkyl group, substituted aryl group, substituted alkenyl group and substituted alkynyl group include a halogen atom (—F, —B, —Cl, —I), a hydroxyl group, an alkyl group, an aryl group, an alkoxy group, and aryloxy. Group, amino group, cyano group, nitro group and the like.

In the present specification, a substituted oxy group may be represented by R ⁵ O—, where R ⁵ is a monovalent nonmetallic atomic group excluding hydrogen. Preferred examples of the substituted oxy group include an alkoxy group, an aryloxy group, an acyloxy group, and an arylsulfoxy group. Specific examples of preferred substituted oxy groups include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, phenoxy, tolyloxy, xylyloxy, mesityloxy, cumenyloxy, methoxyphenyloxy, ethoxyphenyloxy Group, chlorophenyloxy group, bromophenyloxy group, acetyloxy group, benzoyloxy group, naphthyloxy group, phenylsulfonyloxy group, and the like.

In the present specification, as the substituted thio group, those represented by R ⁷ S—, in which R ⁷ is a monovalent nonmetallic atomic group excluding hydrogen, can be used. Examples of preferred substituted thio groups include alkylthio groups and arylthio groups. Specific examples of preferable substituted thio groups include a methylthio group, an ethylthio group, a phenylthio group, an ethoxyethylthio group, a carboxyethylthio group, and a methoxycarbonylthio group.

In the present specification, the substituted amino group is represented by R ⁸ NH—, (R ⁹ ) (R ¹⁰ ) N—, and R ⁸ , R ⁹ and R ¹⁰ are monovalent nonmetallic atomic groups excluding hydrogen. Can be used. Preferable examples of the substituted amino group include N-alkylamino group, N, N-dialkylamino group, N-arylamino group, acylamino group and the like. Specific examples of preferred substituted amino groups include methylamino group, ethylamino group, diethylamino group, morpholino group, piperidino group, pyrrolidino group, phenylamino group, benzoylamino group, acetylamino group and the like.

In the present specification, a substituted carbonyl group represented by R ¹¹ —CO—, wherein R ¹¹ is a monovalent nonmetallic atomic group can be used. Preferred examples of the substituted carbonyl group include formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, Is mentioned. Specific examples of preferred substituted carbonyl groups include formyl group, acetyl group, benzoyl group, carboxyl group, methoxycarbonyl group, allyloxycarbonyl group, N-methylcarbamoyl group, N-phenylcarbamoyl group, N, N-diethylcarbamoyl group. And a morpholinocarbonyl group.

In the present specification, the carboxylate group (—CO ₂ ⁻ ) means a conjugate base anion group of a carboxyl group (CO ₂ H), and is usually preferably used together with a counter cation. Examples of such counter cations include those generally known, that is, various oniums (ammonium compounds, sulfonium compounds, phosphonium compounds, iodonium compounds, azinium compounds, etc.), and metal ions (Na ⁺ , K ⁺ , Ca). ²⁺ , Zn ^2+, etc.).

  X represents a substituent selected from a bromine atom, a substituted peroxy group, a mercapto group, a substituted thio group, and a substituted sulfonyl group.

  Examples of the substituent in the substituted peroxy group (R—O—O—) for X include an alkyl group and an aryl group, and an alkyl group is more preferable.

As the substituted thio group for X, those represented by R ⁷ S—, in which R ⁷ is a monovalent nonmetallic atomic group excluding hydrogen, can be used. Examples of preferred substituted thio groups include alkylthio groups and arylthio groups. Specific examples of preferred substituted thio groups include methylthio group, ethylthio group, t-butylthio group, phenylthio group, ethoxyethylthio group, carboxyethylthio group, methoxycarbonylthio group and the like.

The substituted sulfonyl group of X is represented by R—SO ₂ —, and specific examples of the preferred substituted sulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, and a phenylsulfonyl group.

Next, Y will be described. Y represents —CN or —COZ, and Z represents a group bonded to the carbonyl group via a hetero atom or a halogen atom. A group bonded to a carbonyl group through a hetero atom is preferable. Examples of the hetero atom at this time include an oxygen atom, a nitrogen atom, and a sulfur atom, and an oxygen atom and a nitrogen atom are preferable, and an oxygen atom is more preferable. Preferred as a “group bonded to a carbonyl group through a heteroatom” represented by Z is preferably a hydroxyl group, a substituted oxy group, a mercapto group, a substituted thio group, an amino group, a substituted amino group, a sulfo group, a sulfonate group, a substituted group Examples thereof include a sulfinyl group, a substituted sulfonyl group, a phosphono group, a substituted phosphono group, a phosphonato group, a substituted phosphonato group, a nitro group, and a heterocyclic group (which are linked by a heteroatom).
Examples of the substituted oxy group, substituted thio group, substituted amino group, and substituted sulfonyl group include those described above for Ra, Rb, and X.

As the substituted sulfinyl group, those represented by R ¹² —SO—, wherein R ¹² is a monovalent nonmetallic atomic group can be used. Preferable examples include alkylsulfinyl group, arylsulfinyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl. Group, N-alkyl-N-arylsulfinamoyl group. Examples of the alkyl group and aryl group in these include those described above as the alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Of these, more preferred examples include an alkylsulfinyl group and an arylsulfinyl group. Specific examples of such a substituted sulfinyl group include a hexylsulfinyl group, a benzylsulfinyl group, and a tolylsulfinyl group.

A sulfonate group (—SO ₃ ⁻ ) means a conjugate base anion group of a sulfo group (—SO ₃ H), and is usually preferably used together with a counter cation. Examples of such counter cations include those generally known, that is, various oniums (ammonium compounds, sulfonium compounds, phosphonium compounds, iodonium compounds, azinium compounds, etc.), and metal ions (Na ⁺ , K ⁺ , Ca). ²⁺ , Zn ^2+, etc.).

  The substituted phosphono group means a group in which one or two hydroxyl groups on the phosphono group are substituted with other organic oxo groups, and preferred examples thereof include the above-mentioned dialkylphosphono group, diarylphosphono group, alkylarylphospho group. Group, monoalkylphosphono group and monoarylphosphono group. Of these, dialkylphosphono groups and diarylphosphono groups are more preferred. Specific examples thereof include a diethyl phosphono group, a dibutyl phosphono group, a diphenyl phosphono group, and the like.

As described above, the phosphonate group (—PO ₃ ²⁻ , —PO ₃ H ⁻ ) is a conjugated base anion group derived from the acid first dissociation or acid second dissociation of the phosphono group (—PO ₃ H ₂ ). Means. Usually, it is preferable to use it with a counter cation. Examples of such counter cations include those generally known, that is, various oniums (ammonium compounds, sulfonium compounds, phosphonium compounds, iodonium compounds: azinium compounds, etc.), and metal ions (Na ⁺ , K ⁺ , Ca ²⁺ , Zn ²⁺ etc.).

In the present specification, the substituted phosphonato group is a conjugated base anion group obtained by substituting one organic oxo group in the above-mentioned substituted phosphono group. Specific examples thereof include the monoalkylphosphono group (- PO ₃ H (alkyl)), and a conjugate base of a monoarylphosphono group (—PO ₃ H (aryl)). Usually, it is preferable to use it with a counter cation. Such counter cations include those generally known, that is, various oniums (ammonium, sulfonium, phosphonium, iodonium, azinium, etc.) and metal ions (Na ⁺ , K ⁺ , Ca ²⁺ , Zn ²⁺ etc.).

In this specification, the heterocyclic group means a monovalent group obtained by removing one hydrogen on the heterocyclic ring, and further removing one hydrogen from the monovalent group so that the substituent in the above substituted alkyl group is bonded. A monovalent group (substituted heterocyclic group). Examples of preferred heterocycles include the groups shown below.

In the present invention, specific examples of the compound having the structure represented by the general formula (I) are shown below, but the present invention is not limited thereto.

  The ratio of the polymerizable compound represented by the general formula (I) used in the present invention to the total ink weight is 0.01 to 4.5% by mass, preferably 0.05 to 3% by mass, and more preferably. Is 0.1 to 2% by mass.

[Polymerizable compounds other than (b) and (a)]
The polymerizable compound other than (b) and (a) used in the present invention is not particularly limited as long as it is a compound that causes a polymerization reaction and cures by an active species (radical) generated from (c) a polymerization initiator described later. Absent.

[Radically polymerizable compound]
The radical polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization, and may be any compound as long as it has at least one ethylenically unsaturated bond capable of radical polymerization in the molecule. , Oligomers, polymers and the like having a chemical form. Only one kind of such radically polymerizable compounds may be used, or two or more kinds thereof may be used in combination at an arbitrary ratio in order to improve desired properties. A polyfunctional compound having two or more functional groups is more preferable than a monofunctional compound. More preferably, two or more polyfunctional compounds are used in combination for controlling performance such as reactivity and physical properties.

  Examples of radical polymerizable compounds include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and their salts, esters, urethanes, amides and anhydrides, acrylonitrile, styrene, Furthermore, radically polymerizable compounds such as various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides and unsaturated urethanes can be mentioned. Specifically, 2-ethylhexyl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, bis (4-acryloxypolyethoxyphenyl) propane, Neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraa Relate, dipentaerythritol tetraacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, N-methylolacrylamide, diacetone acrylamide, epoxy acrylate, urethane acrylate and other acrylic acid derivatives, methyl methacrylate, n-butyl Methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene Glycol dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, methacryl derivatives such as 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, allyl glycidyl ether, diallyl phthalate, triallyl trimelli Derivatives of allyl compounds such as tate are mentioned. More specifically, Yamashita Junzo, “Crosslinking agent handbook” (1981 Taiseisha); Kato Kiyomi, “UV / EB curing handbook (raw material)” (1985, Polymer Publications); Radtech Study Group, "Application and Market of UV / EB Curing Technology", 79 pages (1989, CMC); Eiichiro Takiyama, "Polyester Resin Handbook", (1988) Commercial products or industry as described in Nikkan Kogyo Shimbun) And known radically polymerizable or crosslinkable monomers, oligomers and polymers can be used.

Other examples of radically polymerizable compounds include α-heteromethacrylic compounds in which X is a heteroatom other than bromine atom, substituted peroxy group, mercapto group, substituted thio group and substituted sulfonyl group in general formula (I) Preferably used. Examples include an oxygen atom, a nitrogen atom, and a phosphorus atom, preferably an oxygen atom and a nitrogen atom, and more preferably an oxygen atom. Specific examples of such α-heteromethacrylic compounds are shown below.

[(C) Polymerization initiator]
Examples of the polymerization initiator in the present invention include known radical polymerization photopolymerization initiators used in radiation curable ink compositions. Other photopolymerization initiators that can be used in combination with the present invention are compounds that generate radicals through chemical action through the action of light or interaction with the electronically excited state of a sensitizing dye. Specific photopolymerization initiators known among those skilled in the art can be used without limitation. Specifically, for example, Bruce M. Monroe et al., Chemical Review, 93, 435 (1993), RSD Davidson, Journal of Photochemistry and biology A: Chemistry, 73, 81 (1993), JP Faussier "Photoinitiated Polymerization -Theory and Applications ": Rapra Review vol. 9, Report, Rapra Technology (1998) and M. Tsunooka et al., Prog. Polym. Sci., 21, 1 (1996). Further, many compounds used for chemically amplified photoresists are described in (Organic Electronics Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), pages 187 to 192). Furthermore, FDSaeva, Topics in Current Chemistry, 156, 59 (1990), GG Maslak, Topics in Current Chemistry, 168, 1 (1993), HB Shuster et al, J. Am. Chem. Soc., 112, 6329 ( 1990), IDFEaton et al, J. Am. Chem. Soc, 102, 3298 (1980) and the like, through the interaction with the electronically excited state of the sensitizing dye, oxidatively or reductively. A group of compounds that cause bond cleavage is also known.

  Preferred photopolymerization initiators include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, (e) ketoxime ester compounds, (F) a borate compound, (g) an azinium compound, (h) a metallocene compound, (i) an active ester compound, (j) a compound having a carbon halogen bond, and the like.

  (A) Preferable examples of aromatic ketones include compounds having a benzophenone skeleton or a thioxanthone skeleton described in “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” J. P. FOUASSIER J. F. RABEK (1993), p77-117. More preferable examples of (a) aromatic ketones include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, and JP-B-47-22326. Α-substituted benzoin compounds, benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, Benzoin ethers described in JP-A-60-26403, JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, and α-aminobenzophenones described in European Patent 0284561A1, P-di (dimethyla) described in JP-A-2-211452 Nobenzoyl) benzene, thio-substituted aromatic ketone described in JP-A-61-194062, acylphosphine sulfide described in JP-B-2-9597, acylphosphine described in JP-B-2-9596, JP-B-63- Examples thereof include thioxanthones described in Japanese Patent No. 61950, and coumarins described in Japanese Patent Publication No. 59-42864.

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

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

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

  (E) Examples of ketoxime ester compounds include 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, and 2-acetoxyiminopentane-3. -One, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-p-toluenesulfonyloxyiminotan-2-one, 2-ethoxy And carbonyloxyimino-1-phenylpropan-1-one.

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

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

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

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

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

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

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

In the structural formula of the above compound, Ar represents a phenyl group, a paramethoxyphenyl group, or a dimethylaminophenyl group.

When the other polymerization initiators described above are used in combination, the content thereof is preferably 0.1 to 20% by mass with respect to the total solid content of the ink composition.
As the polymerization initiator, various known compounds can be used, but it is preferable to select one that is soluble in the polymerizable compound according to the present invention. Specific examples of the polymerization initiator include xanthone or Examples thereof include thioxanthone polymerization initiators, benzophenone polymerization initiators, quinone synthesis initiators, and phosphine oxide polymerization initiators.

  Moreover, it is preferable to add 200 to 20000 ppm of a polymerization inhibitor from the viewpoint of improving storage stability. The ink composition for inkjet recording of the present invention is preferably ejected by heating and lowering the viscosity in the range of 40 to 80 ° C., and a polymerization inhibitor is preferably added to prevent clogging of the head due to thermal polymerization. Examples of the polymerization inhibitor include hydroquinone, benzoquinone, p-methoxyphenol, TEMPO, TEMPOL, and cuperon Al.

(D) Colorant The ink composition of the present invention preferably further contains a colorant. Although there is no restriction | limiting in particular as a coloring agent which can be used by this invention, Although the pigment excellent in the weather resistance is preferable, Arbitrary well-known coloring agents, such as a soluble dye and an oil-based dye, can be used.

  The pigment preferably used in the present invention will be described. The ink composition of the present invention does not necessarily have high color developability (color density per added density), and in addition, it is difficult to produce a homogeneous fine particle dispersion. Therefore, ink jet inks that have not been put into practical use can be used. Although not particularly limited, for example, organic or inorganic pigments having the following numbers described in the color index can be used in the present invention.

  Pigment Red 3, 5, 19, 22, 31, 38, 43, 48; 1, 48: 2, 48: 3, 48: 4, 48: 5, 49: 1, 53: 1 as red or magenta pigment , 57: 1, 57: 2, 58: 4, 63: 1, 81, 81: 1, 81: 2, 81: 3, 81: 4, 88, 104, 108, 112, 122, 123, 144, 146 , 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13 16, 20, 36, blue or cyan pigments include Pigment Blue 1, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17-1, 22, 27, 28, 29, 36, 60, as green pigment, Pigment Green 7, 26, 36, 50, as yellow pigment, Pigment Yel1ow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193, Pigment Black 7, 28, 26, and white pigments such as Pigment White 6, 18, 21 can be used depending on the purpose.

  For the dispersion of the pigment, for example, various dispersion devices such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, and a paint shaker can be used. Further, it is possible to add a dispersant when dispersing the pigment. The type of the dispersant is not particularly limited, but a polymer dispersant is preferably used. Examples of the polymer dispersant include Solsperse series manufactured by Zeneca. Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 5.0 parts by mass with respect to 100 parts by mass of the pigment. The dispersion medium is a solvent or a polymerizable compound according to the present invention. However, in the radiation curable ink composition used in the present invention, it is preferably solventless because it reacts and cures immediately after ink landing. If the solvent remains in the cured image, the solvent resistance deteriorates and the VOC (Volatile Organic Compound) of the remaining solvent causes problems. Therefore, it is preferable in view of dispersibility that the dispersion medium is not a solvent, but a polymerizable compound, and a monomer having the lowest viscosity among them is selected.

  The average particle diameter of the pigment particles is preferably 0.08 to 0.5 μm, and the maximum particle diameter is 0.3 to 10 μm, preferably 0.3 to 3 μm, so that the pigment, the dispersant and the dispersion medium are selected, the dispersion conditions, and the filtration conditions. Set. By controlling the particle size, clogging of the head nozzle can be suppressed, and the storage stability, ink transparency, and curing sensitivity of the ink composition can be maintained. The color material is preferably added in an amount of 1 to 10% by mass, more preferably 2 to 8% by mass, based on the total ink mass.

  In addition to the above description, other components can be added to the ink composition for ink jet recording of the present invention as necessary.

  When electron beam, X-ray, etc. are used as irradiation light, a polymerization initiator is not necessary, but when ultraviolet light (UV light), visible light or infrared light is used as a radiation source, it depends on the respective wavelength. A radical polymerization initiator, a polymerization initiation assistant, a sensitizing dye, and the like are added. The amount of these compounds added generally needs to be 1 to 10% by mass of the total ink composition. As the polymerization initiator, various known compounds can be used, but it is preferable to select one that is soluble in the polymerizable compound according to the present invention. Specific examples of the polymerization initiator include xanthone or Examples thereof include thioxanthone polymerization initiators, benzophenone polymerization initiators, quinone polymerization initiators, and phosphine oxide polymerization initiators.

  Moreover, it is preferable to add 200 to 20000 ppm of a polymerization inhibitor from the viewpoint of improving storage stability. The ink composition for inkjet recording of the present invention is preferably ejected by heating and lowering the viscosity in the range of 40 to 80 ° C., and a polymerization inhibitor is preferably added to prevent clogging of the head due to thermal polymerization. Examples of the polymerization inhibitor include hydroquinone, benzoquinone, p-methoxyphenol, TEMPO, TEMPOL, and cuperon Al.

[Others]
In addition, known compounds can be used as necessary. For example, surfactants, leveling additives, matting agents, polyester resins for adjusting film properties, polyurethane resins, vinyl resins, acrylic resins. Resin, rubber resin, wax and the like can be appropriately selected and used. In order to improve the adhesion to a recording medium such as polyolefin or PET, it is also preferable to contain a tackifier that does not inhibit the polymerization. Specifically, high molecular weight adhesive polymers described in JP-A-2001-49200, 5-6P (for example, esters of (meth) acrylic acid and alcohols having an alkyl group having 1 to 20 carbon atoms) , An ester of (meth) acrylic acid and an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer of an ester of (meth) acrylic acid and an aromatic alcohol having 6 to 14 carbon atoms), A low molecular weight tackifying resin having a saturated bond.

  It is also effective to add a trace amount of organic solvent in order to improve the adhesion to the recording medium. In this case, it is effective to add in a range that does not cause the problem of solvent resistance and VOC, and the amount is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass with respect to the entire ink composition. is there.

Further, as a means for preventing a decrease in sensitivity due to the light-shielding effect of the ink color material, it is also preferable to combine a cationic polymerizable monomer having a long polymerization initiator life and a polymerization initiator into a radical-cation hybrid curable ink composition. one of.
The ink composition of the present invention preferably has an ink viscosity of 7 to 30 mPa · s, more preferably 7 to 20 mPa · s at the temperature at the time of ejection in consideration of ejection properties, so that it falls within the above range. It is preferable to adjust the composition ratio appropriately. The ink viscosity at 25 to 30 ° C. is 35 to 500 mPa · s, preferably 35 to 200 mPa · s. By setting the viscosity at room temperature high, even when a porous recording medium is used, ink penetration into the recording medium can be prevented, uncured monomer can be reduced, and odor can be reduced. Dot melting at the time of landing can be suppressed, and as a result, image quality is improved. If the ink viscosity at 25 to 30 ° C. is less than 35 mPa · s, the effect of preventing bleeding is small, and conversely if it is greater than 500 mPa · s, there is a problem in the delivery of the ink liquid.

  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 polioffin, PET, coated paper, and uncoated 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.

(2) Lithographic printing plate and method for producing the same The lithographic printing plate of the present invention is formed by jetting and landing the above-described ink composition of the present invention on a hydrophilic support, and then irradiating the ink composition with the ink composition. Is a lithographic printing plate having a hydrophobic region formed by curing. The lithographic printing plate forms a hydrophobic region by spraying the ink composition of the present invention described above onto a hydrophilic support, landing, and then irradiating with radiation to cure the ink composition. It is characterized by.

(2-1-1) Lithographic printing plate Here, the lithographic printing plate has a hydrophilic support and an image formed on the support.
Conventionally, so-called PS plates having a configuration in which a lipophilic photosensitive resin layer is provided on a hydrophilic support have been widely used as lithographic printing plates. As a method for producing the PS plate, a desired printing plate is usually obtained by performing mask exposure (surface exposure) through a lith film and then dissolving and removing the non-exposed portion. However, in recent years, digitization 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 printing plates. 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 ink is ejected onto a support, preferably a hydrophilic support, by an ink jet method or the like, and exposed to radiation, whereby a portion of the ink composition is exposed to form a desired image (preferably hydrophobic). A printing plate having a sex image) is obtained. An ink composition suitable for such a system is the ink composition of the present invention.

[Support]
The support used in the present invention is not particularly limited as long as it is a dimensionally stable plate-like hydrophilic support. For example, paper, paper laminated with plastic (for example, polyethylene, polypropylene, polystyrene, etc.), metal plate (for example, aluminum, zinc, copper, etc.), plastic film (for example, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which the above-mentioned metal is laminated or deposited. Preferable supports include 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 different elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. Examples of foreign elements contained in the anorenium 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 publicly 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 a 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 (electrochemical surface roughening treatment that dissolves the surface), chemical surface treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Also, a transfer method in which the uneven shape is transferred with a roll provided with unevenness in the aluminum rolling step may be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing drunks such as hydrochloric acid and 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 of 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., the current density is 5 to 60 A / It is preferable that dm ² , voltage 1 to 100 V, and electrolysis time be 10 seconds to 5 minutes. The amount of the anodized film formed is preferably from 1.0~5.10g / 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 lithographic printing plate can be obtained.

  As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation and the like. If necessary, it is immersed in an aqueous solution containing a hydrophilic compound and a micropore enlargement treatment or sealing treatment of an anodized film described in JP 2001-253181 A or JP 2001-322365 A The surface hydrophilization treatment to be performed 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 fluorinated zirconic acid, sealing with an aqueous solution containing an inorganic fluorine compound such as treatment with sodium fluoride, vapor sealing with lithium sakafide, and hot water. Sealing treatment is also possible.
Of these, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing treatment with hot water are preferable. Each will be described below.

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

  The concentration of the inorganic fluorine compound in the aqueous solution is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, from the viewpoint of sufficiently sealing the micropores of the anodized film. In terms of dirtiness, the content is preferably 1% by mass or less, and more preferably 0.5% by mass or less.

  It is preferable that the permanent solution containing an 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.

As the phosphate compound, for example, metal phosphates such as alkali metals and alkaline earth metals are preferably mentioned.
Specifically, for example, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium hydrogen phosphate , Magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, disodium hydrogen phosphate, lead phosphate, diammonium phosphate, diphosphate Examples include calcium hydrogen, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate, sodium phosphite, sodium tripolyphosphate, and sodium pyrophosphate. Of these, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are preferable.
The combination of the inorganic fluorine compound and the phosphate compound is not particularly limited, but the aqueous solution contains at least sodium zirconate fluoride as the inorganic fluorine compound and contains at least sodium dihydrogen phosphate as the phosphate compound. Is preferred.
The concentration of the phosphoric acid block compound in the aqueous solution is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of improving on-press developability and stain resistance, and solubility. In this respect, it is preferably 20% by mass or less, and more preferably 5% by 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, preferably 100 ° C. or lower, more preferably 80 ° C. or lower.
In addition, the water groove liquid 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 a plurality of times, or two or more kinds may be used in combination.
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, more preferably 100 seconds or shorter, and 20 seconds or shorter. Is more preferable.

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

<Sealing treatment with hot water>
Examples of the sealing treatment with water vapor include a method in which an aluminum plate on which an anodized film is formed is immersed in hot water.
The hot water may contain an inorganic salt (for example, phosphate) or an organic salt. The temperature of the hot water is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and preferably 100 ° C. or lower.
Further, the time of immersion in hot water is preferably 1 second or longer, more preferably 3 seconds or longer, 100 seconds or shorter, more preferably 20 seconds or shorter.

  Examples of the hydrophilic treatment used in the present invention include alkali metal silicate methods as described in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium fluoride zirconate described in JP-B 36-22063, as described in the specifications of U.S. Pat.Nos. 3,276,868, 4,153,461 and 4,689,272. And a method of treating with polyvinyl phosphonic acid.

  The support in the present invention preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good density with the image recording layer, good printing durability and good stain resistance can be obtained.

(2-1-2) Step of ejecting the ink composition onto the hydrophilic support When the ink composition of the present invention is ejected onto the surface of the hydrophilic support, the ink composition is heated at 40 to 80 ° C. Preferably, the ink composition is ejected after being heated to 25 to 30 ° C. to lower the viscosity of the ink composition to 7 to 30 mPa · s, preferably 7 to 20 mPa · s. In particular, when an ink composition having an ink viscosity of 35 to 500 mPa · s at 25 ° C. is used, a great effect can be obtained. By using this method, high injection stability can be realized. A radiation curable ink composition such as the ink composition of the present invention generally has a higher viscosity than water-based inks used in ordinary ink-jet recording ink compositions, and therefore has a large viscosity variation due to temperature variations during printing. The ink viscosity fluctuation has a great influence on the change in the droplet size and the change in the ejection speed of the droplets, thereby causing deterioration of the image quality. Therefore, it is necessary to keep the temperature of ink at the time of printing as constant as possible. Therefore, it is appropriate that the control range of the temperature of the present invention is the set temperature ± 5 ° C., preferably the set temperature ± 2 ° C., more preferably the set temperature ± 1 ° C.

(2-1-3) Step of curing the ink by irradiating the hydrophilic support on which the ink has been ejected The ink ejected on the surface of the hydrophilic support is cured by irradiating with the radiation. To do. This is because the sensitizing dye in the polymerization initiation system contained in the ink composition of the present invention absorbs radiation to be in an excited state, and the polymerization initiator is decomposed by contact with the polymerization initiator in the polymerization initiation system. This is because the polymerizable compound is cured by radical polymerization.

Here, α-rays, γ-rays, electron beams, X-rays, ultraviolet rays, visible light, infrared light, or the like can be used as the radiation used. The peak wavelength of the radiation is, for example, 200 to 600 nm, preferably 300 to 450 nm, more preferably 350 to 450 nm, depending on the absorption characteristics of the sensitizing dye. In addition, the polymerization initiation system of the present invention has sufficient sensitivity even with low output radiation. Thus, the output of radiation, for example, 2000 mJ / cm ² or less, preferably, 10 to 2000 mJ / cm ^2, more preferably, 20~1000mJ / cm ^2, more preferably, irradiation energy of 50 to 800 mJ / cm ² It is appropriate to be. Moreover, it is appropriate that the radiation is irradiated at an exposure surface illuminance of, for example, 10 to 2000 mW / cm ² , preferably 20 to 1000 mW / cm ² .

The ink composition of the present invention is appropriately irradiated with such radiation for, for example, 0.01 to 120 seconds, preferably 0.1 to 90 seconds.
Radiation irradiation conditions and a basic irradiation method are disclosed in JP-A-60-132767. Specifically, the light source is provided on both sides of the head unit including the ink ejection device, and the head unit and the light source are scanned by a so-called shuttle method. Irradiation of radiation takes a certain time (for example, 0.01 to 0.5 seconds, preferably 0.01 to 0.3 seconds, more preferably 0.01 to 0.15 seconds) after ink landing. Will be done.

  In this way, by controlling the time from ink landing to irradiation to an extremely short time, it is possible to prevent the ink that has landed on the recording medium from spreading before curing. Further, since the ink can be exposed to a porous recording medium before the ink penetrates to a deep part where the light source does not reach, residual unreacted monomer can be suppressed, and as a result, odor can be reduced. .

  Further, the curing may be completed by another light source that is not driven. In WO99 / 54415, as an irradiation method, a method using an optical fiber or a method in which a collimated light source is applied to a mirror surface provided on the side surface of the head unit to irradiate the recording unit with UV light is disclosed.

By adopting the ink jet recording method as described above, the dot diameter of the landed ink can be kept constant even on various recording media having different surface wettability, and the image quality is improved. In addition, in order to obtain a color image, it is preferable to superimpose in order from the color with the lowest brightness. By superimposing the inks in the order of low lightness, the irradiation line can easily reach the lower ink, and good curing sensitivity, reduction of residual monomers, reduction of odor, and improvement of adhesion can be expected. Irradiation can be performed by injecting all colors and exposing them together, but exposure for each color is preferable from the viewpoint of curing acceleration.
In this way, the ink composition of the present invention is cured by irradiation with radiation to form a hydrophobic image on the surface of the hydrophilic support.

(3) Inkjet recording method and printed matter The inkjet recording method of the present invention includes a step of jetting and landing the above-described ink composition onto a recording medium, and a step of curing the ink composition by irradiating with radiation. An inkjet recording method characterized by the above.

  In the ink jet recording method, it is preferable that the ink composition is heated to 40 to 80 ° C. to reduce the viscosity of the ink composition to 7 to 30 mPa · s and then ejected. Stability can be achieved. In general, radiation curable ink compositions generally have a higher viscosity than aqueous inks, so that the viscosity fluctuation range due to temperature fluctuations during printing is large. This viscosity variation of the ink composition directly affects the droplet size and droplet ejection speed as it is, which causes image quality deterioration. Therefore, it is necessary to keep the ink composition temperature as constant as possible during printing. is there. The control range of the ink composition temperature is preferably set temperature ± 5 ° C, more preferably set temperature ± 2 ° C, and still more preferably set temperature ± 1 ° C.

  One feature of the ink jet recording apparatus used in the ink jet recording method is that it includes a means for stabilizing the temperature of the ink composition, and the portion to be kept at a constant temperature is ejected from an ink tank (intermediate tank if there is an intermediate tank). All piping systems and members up to the surface are targeted.

The temperature control method is not particularly limited, but for example, it is preferable to provide a plurality of temperature sensors in each piping portion and perform heating control according to the ink composition flow rate and the environmental temperature.
Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside air. In order to shorten the printer start-up time required for heating or to reduce the loss of thermal energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

  Next, radiation conditions will be described. The basic irradiation method is closed in JP-A-60-132767. Specifically, a light source is provided on both sides of the head unit, and the head and the light source are scanned by a shuttle method. Irradiation is performed after a certain period of time after the ink composition has landed. Further, the curing is completed by another light source that is not driven. WO99 / 54415 discloses a method using an optical fiber or a method of irradiating a recording unit with UV light by applying a collimated light source to a mirror surface provided on the side of the head unit. In the present invention, these irradiation methods can be used.

  In the present invention, the ink composition is heated to a constant temperature, and the time from landing to irradiation is preferably 0.01 to 0.5 seconds, preferably 0.01 to 0.3 seconds, more preferably 0.01 to 0.15 seconds later. Is to irradiate. Thus, by controlling the time from landing to irradiation to an extremely short time, it is possible to prevent the landing ink from bleeding before curing. Also, since the ink composition can be exposed to a porous recording medium before it penetrates deeper than the light source reaches, unreacted monomer remains, and as a result, odor can be reduced. Can do. By using the inkjet recording method described above and the ink composition of the present invention in combination, a great synergistic effect is brought about. In particular, when an ink composition having an ink composition viscosity of 35 to 500 MPa · s at 25 ° C. is used, a great effect can be obtained. By adopting such a recording method, the dot diameter of the ink composition that has landed on various recording media having different surface wettability can be kept constant, and the image quality is improved. In addition, in order to obtain a color image, it is preferable to superimpose in order from the color with the lowest brightness. When an ink composition having a low lightness is stacked, it is difficult for an irradiation beam to reach the lower ink composition, and the curing sensitivity is hindered, the residual monomer is increased, odor is generated, and the adhesion is liable to occur. Irradiation can be performed by injecting all colors and exposing them together, but exposure for each color is preferable from the viewpoint of promoting curing.

  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 Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the embodiments in these examples.

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

(Yellow pigment dispersion 1)
(D) C.I. I. Pigment Yellow 12 10 parts by weight Polymer Dispersant (Solsperse series manufactured by Zeneca) 5 parts by weight Lauryl acrylate 85 parts by weight (magenta pigment dispersion 1)
(D) C.I. I. Pigment Red 57: 1 15 parts by mass Polymer dispersant (Solsperse series manufactured by Zeneca) 5 parts by mass Lauryl acrylate 80 parts by mass (Cyan Pigment Dispersion 1)
(D) C.I. I. Pigment Blue 15: 3 20 parts by mass Polymer dispersing agent (Solsperse series manufactured by Zeneca) 5 parts by mass Lauryl acrylate 75 parts by mass (Black pigment dispersion 1)
(D) C.I. I. Pigment Black 7 20 parts by mass Polymer dispersant (Solsperse series manufactured by Zeneca) 5 parts by mass Lauryl acrylate 75 parts by mass

<Preparation of ink>
Each color ink was prepared using each of the dispersions 1 prepared above according to the method described below.

(Yellow ink 1)
(Containing (d)) 20 parts by mass of yellow pigment dispersion 1 (a) 1 part by mass of the present compound (I-6) (b) 30 parts by mass of 2-ethylhexyl acrylate (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

(Magenta ink 1)
(Containing (d)) magenta pigment dispersion 1 20 parts by mass (a) present compound (I-6) 1 part by mass (b) 2-ethylhexyl acrylate 30 parts by mass (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

(Cyan ink 1)
(Contains (d)) 20 parts by mass of Cyan Pigment Dispersion 1 (a) 1 part by mass of the present compound (I-6) (b) 30 parts by mass of 2-ethylhexyl acrylate (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

(Black ink 1)
(Containing (d)) Black pigment dispersion 1 20 parts by mass (a) Compound (I-6) of the present invention 1 part by mass (b) 30 parts by mass of 2-ethylhexyl acrylate (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass Each color ink 1 prepared as described above was filtered with a filter having an absolute filtration accuracy of 2 μm to obtain ink 1 of each color.

<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, a supply pipe, 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-A light is condensed to an exposure surface illuminance of 100 mW / cm ² , and the exposure system, main scanning speed and ejection frequency are adjusted so that irradiation starts 0.1 seconds after ink landing on the recording medium. . Further, the exposure time was variable, and exposure energy was irradiated. In the present invention, dpi represents the number of dots per 2.54 cm.

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

Examples 2-5
<Preparation of ink>
Magenta inks 2-5 were prepared according to the method described below.

(Magenta ink 2)
(Containing (d)) magenta pigment dispersion 1 20 parts by mass (a) present compound (I-4) 1 part by mass (b) 2-ethylhexyl acrylate 30 parts by mass (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

(Magenta ink 3)
(Containing (d)) magenta pigment dispersion 1 20 parts by mass (a) present compound (I-20) 1 part by mass (b) 2-ethylhexyl acrylate 30 parts by mass (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

(Magenta ink 4)
(Containing (d)) magenta pigment dispersion 1 20 parts by mass (a) the present compound (I-27) 1 part by mass (b) 2-ethylhexyl acrylate 30 parts by mass (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

(Magenta ink 5)
(Containing (d)) magenta pigment dispersion 1 20 parts by mass (a) compound (I-37) of the present invention 1 part by mass (b) 30 parts by mass of 2-ethylhexyl acrylate (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

(Magenta ink 6)
(Containing (d)) Magenta pigment dispersion 1 20 parts by mass (a) Compound (I-6) of the present invention 1 part by mass (b) Compound (A-1) 30 parts by mass (b) 1,6-hexanediol 35 parts by mass of diacrylate (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

<Preparation of magenta pigment dispersion 2>
A magenta pigment dispersion 2 was prepared in the same manner as in the preparation of the magenta pigment dispersion 1 described in Example 1, except that isobornyl acrylate was used instead of stearyl acrylate.

(Magenta ink 7)
(Containing (d)) magenta pigment dispersion 2 20 parts by mass (a) the present compound (I-20) 1 part by mass (b) 2-ethylhexyl acrylate 30 parts by mass (b) 1,6-hexanediol diacrylate 35 parts by mass (b) 7 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate (c) polymerization initiator (manufactured by Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

Comparative Example << Preparation of ink >>
Magenta ink 8 was prepared according to the method described below.
(Magenta ink 8: Comparative example)
(Containing (d)) magenta pigment dispersion 1 20 parts by mass (b) 30 parts by mass of 2-ethylhexyl acrylate (b) 36 parts by mass of 1,6-hexanediol diacrylate (b) caprolactone-modified dipentaerythritol hexaacrylate 7 Mass part (c) Polymerization initiator (Ciba Specialty Chemicals,
IRGACURE 1870) 7 parts by mass

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

<Inkjet image recording>
Using the magenta inks 2 to 8 prepared as described above and the magenta ink 1 prepared in Example 1, magenta image printing was performed in the same manner as the method described in Example 1.

<Evaluation of inkjet image>
Next, for each formed image, in accordance with the method described below, the evaluation of the flexibility of the cured film, the sensitivity required for curing, the adhesion with a grained aluminum support, the printing durability, and the storage stability were evaluated. went.

(Evaluation of film flexibility)
After the printed quality paper was bent 1 to 10 times, the presence or absence of cracks was visually observed. The flexibility of the film was evaluated by the number of bendings at which cracks were first recognized. (The higher the number of times, the better the flexibility)

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

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

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

(Evaluation of storage stability)
The prepared ink was stored at 75% RH and 60 ° C. for 3 days, and then the ink viscosity at the injection temperature was measured. The increase in the ink viscosity was expressed as the viscosity ratio after storage / before storage. When the viscosity does not change and is close to 1.0, the storage stability is good, and when it exceeds 1.5, clogging may occur at the time of injection, which is not preferable.
These evaluation results are shown in Table 1.

All ink compositions containing the compound (a) of the present invention were excellent in flexibility of the cured film, had high adhesion to an aluminum support, and high printing durability when used as a printing plate.
On the other hand, when the ink composition not containing the compound (a) of the present invention was used, the flexibility of the cured film was particularly poor. (Comparative example).

Claims (6)

(A) 0.01 to 4.5% by mass of at least one polymerizable compound represented by the following general formula (I) with respect to the total amount of the ink composition, (b) a polymerizable compound other than (a), ( An ink composition comprising: c) a polymerization initiator; and (d) a colorant.

In the formula, R ^a and R ^b each independently represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a substituted oxy group, a substituted thio group, a substituted amino group, a substituted carbonyl group, or a carboxylate group, X represents a substituent selected from a bromine atom, a substituted peroxy group, a mercapto group, a substituted thio group, and a substituted sulfonyl group. Y represents —CN or —COZ, and Z represents a group bonded to the carbonyl group via a hetero atom or a halogen atom. The ink composition according to claim 1, which is for inkjet recording. An ink jet recording method comprising: a step of ejecting and landing the ink composition according to claim 1 on a recording medium; and a step of curing the ink composition by irradiation with radiation. A printed matter obtained by ejecting the ink composition according to claim 1 or 2 onto a recording medium, landing the ink composition, and then irradiating the ink composition to cure the ink composition. A lithographic printing plate, wherein a hydrophobic region is formed by spraying the ink composition according to claim 1 or 2 onto a hydrophilic support and landing, followed by irradiation with radiation to cure the ink. A method for preparing a printing plate. A lithographic printing having a hydrophobic region formed by jetting and landing the ink composition according to claim 1 on a hydrophilic support and then irradiating the ink composition to cure the ink composition. Edition.