JP4630034B2 - Radiation curable inkjet ink composition and planographic printing plate using the same - Google Patents

Description

  The present invention relates to a radiation curable ink composition for inkjet, a lithographic printing plate that does not require development processing, and a method for producing the lithographic printing plate.

The problem of radiation curable ink-jet ink is high sensitivity and high image quality. For high sensitivity, high curability to radiation is not only important in terms of cost, such as reducing power consumption and extending life by reducing the load on the radiation generator, but also low due to inadequate curing, which has been regarded as a problem in the past. It is also strongly desired to avoid problems such as adverse effects on the human body due to molecular components.
Further, when the sensitivity is increased, particularly when used as an image portion of a printing plate, it leads to an increase in the curing strength of the image, and is also expected from the point of high printing durability that is important for the printing plate.
On the other hand, with regard to high image quality, the particle shape after injection onto the image receiving medium is maintained (not crushed), and the particle shape after injection does not deform (do not bleed) on the image receiving medium until it is cured and fixed by radiation. It is important and highly anticipated.
More recently, organic solvent removal has progressed from the viewpoint of environmental problems, and a form of water-based radiation-curable ink is expected (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2002-187918

In response to the above demand, the ink composition of the present invention solves these problems. That is, an object of the present invention is to provide an ink composition for ink jet recording that can be cured by irradiation with radiation, and has a high sensitivity and high image quality, and an aqueous ink composition.
Another object of the present invention is to provide a lithographic printing plate having high sensitivity and high image quality and having high printing durability, which does not require development processing, and a method for producing the same.

An object of the present invention is to provide an inkjet recording ink that can be cured by irradiation with radiation, the inkjet recording ink containing at least one colorant and at least one water-soluble polymerizable compound, and the water-soluble polymerizable compound. The problem is solved by an ink for ink jet recording, wherein the compound is an α-heteromethacrylic compound represented by the following general formula (I).

式(I)中、Ｒはポリオールの残基、またはポリオールのエポキシエステルの残基であり、Ｚはカチオン性基またはアニオン性基を表し、ｋは２〜６であり、Lは１または２である。また、式（II）または（III）において、Ｒ^a、Ｒ^bは各々独立して、水素原子、ハロゲン原子、シアノ基又は有機残基を表し、Ｘ¹は、ヘテロ原子を介して結合した一価の基またはハロゲン原子を表し、Ｘ²は、ヘテロ原子またはヘテロ原子を介した２価の連結基を表し、Ｑ¹は−ＣＮまたは−ＣＯＸ（Ｘはヘテロ原子を介して結合した一価の基またはハロゲン原子を表し）、Ｑ²は−ＣＯ−または−ＣＯ−を介した２価の連結基を表す。また、Ｘ¹とＱ²、Ｒ^aとＲ^b、又はＸ¹とＲ^aあるいはＲ^bとが互いに結合して環状構造を形成してもよい。

In the formula (I), R is a residue of a polyol or a residue of an epoxy ester of a polyol, Z represents a cationic group or an anionic group, k is 2 to 6, L is 1 or 2 is there. In formula (II) or (III), R ^a and R ^b each independently represent a hydrogen atom, a halogen atom, a cyano group, or an organic residue, and X ¹ is a group bonded via a hetero atom. X ² represents a hetero atom or a divalent linking group via a hetero atom, Q ¹ represents —CN or —COX (where X is a monovalent bonded via a hetero atom, Q ² represents a divalent linking group via —CO— or —CO—. X ¹ and Q ² , R ^a and R ^b , or X ¹ and R ^a or R ^b may be bonded to each other to form a cyclic structure.

Another embodiment of the present invention is the ink for ink jet recording, wherein the water-soluble polymerizable compound in the ink composition for ink jet recording is any of the polymerizable substance groups A1 to A11 or B1 to B4 described later.
In another embodiment of the present invention, the ink composition for ink jet recording is ejected onto a hydrophilic support, irradiated with radiation and cured to form a hydrophobic image, and a lithographic printing plate that does not require development processing This is a method for producing a lithographic printing plate.
Another embodiment of the present invention is a radiation curable lithographic printing plate having an image forming layer containing the ink composition for inkjet recording described above on a hydrophilic support.

The ink composition for ink-jet recording of the present invention can provide a higher-sensitivity and higher-quality image than conventional ones, and exhibits excellent stability during storage.
The action mechanism is not clear, but the ejection properties, particle shape retention, curability, etc. of the ink composition are greatly influenced by the properties of the polymerizable compound. The water-soluble α-heteromethacrylic compound used in the composition of the present invention is smoothly injected at the time of injection due to moderate water-solubility and self-aggregation results derived from α-heteromethacrylic groups, and retains the particle shape after injection. (It does not crush, does not penetrate, and does not bleed).
On the other hand, it has been found that the α-heteromethacrylic compound of the present invention not only has a high polymerizability compared to conventional acrylic compounds, but also has a characteristic that it is particularly resistant to oxygen polymerization inhibition. Therefore, it is considered that the effect is remarkable in the UV curable type which is highly curable by radiation (UV or electron beam) and is cured in the atmosphere. In addition, with respect to water-soluble inks, since it is necessary to improve the water resistance and moisture resistance of images, it is necessary that the polymerization curability is particularly higher than that of oil-based inks.
Furthermore, when applied to a lithographic printing plate, the strength of the image area is governed by the curability & strength of the cured film & adhesion to the hydrophilic support, but the ink composition of the present invention has only the above high curability. In addition, the film strength and the adhesion to the support are higher than those of conventional acrylic compounds. The film strength is presumed that self-aggregation worked after curing, and the adhesion to the support originates from the high chemical interaction such as the α-heteromethacrylate compound chelating with the support surface atoms. I believe that.
In addition, the α-heteromethacrylic compound has good storage stability because the thermal polymerizability in the absence of the radical initiator is not higher than that of the acrylic compound.
As described above, the ink composition of the present invention exhibits excellent properties that are not present in the past, and is particularly suitable for use in lithographic printing plate preparation, as well as past knowledge regarding properties such as ink shape retention. The effect which cannot be guessed easily from is demonstrated.

By using the ink composition for ink jet recording of the present invention, a high-sensitivity and high-quality image can be provided. Moreover, the ink composition for inkjet recording of the present invention exhibits excellent stability during storage. The ink composition for inkjet recording of the present invention has water solubility, low viscosity, good co-solubility with various aqueous pigment dispersions, and a high polymerization reaction rate even in the presence of pigments.
A lithographic printing plate using the ink composition of the present invention provides high sensitivity and high image quality. In addition, since the ink composition of the present invention has high drying properties, when used in a lithographic printing plate, it has excellent adhesion to a support, and thus a lithographic printing plate with high printing durability can be obtained.
In addition, the lithographic printing plate production method of the present invention can produce a lithographic printing plate that does not require development, and the lithographic printing plate production method of the present invention does not use an organic solvent. Excellent and does not cause environmental pollution.

  Next, the present invention will be described in detail with reference to preferred embodiments. As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have aimed at an ink composition that is represented by a polymerizable compound that is radically polymerized by radiation, for example, ultraviolet rays, represented by the formula (I). As a result, the present invention was found useful.

The water-soluble polymerizable compound contained in the ink composition of the present invention is represented by the following formula (I). In addition, the structure A in the formula (I) represents an α-heteromethacrylic polymerizable group of the following formula (II) or (III).

In the formula (I), R is a residue of a polyol or a residue of an epoxy ester of a polyol, Z represents a cationic group or an anionic group, k is 2 to 6, L is 1 or 2 is there.
In the formula (II) or (III), R ^a and R ^b each independently represents a hydrogen atom, a halogen atom, a cyano group or an organic residue, and X ¹ represents a monovalent group bonded through a hetero atom. Represents a group or a halogen atom, X ² represents a hetero atom or a divalent linking group via a hetero atom, Q ¹ represents —CN or —COX (X is a monovalent group bonded via a hetero atom or Q ² represents a divalent linking group via —CO— or —CO—. X ¹ and Q ² , R ^a and R ^b , or X ¹ and R ^a or R ^b may be bonded to each other to form a cyclic structure.

Further, each group will be described.
In the general formula (I), X ¹ represents a monovalent group or a halogen atom bonded via a hetero atom, X ² represents a divalent linking group via a hetero atom or a hetero atom, Q ¹ Is —CN or —COX (X represents a monovalent group or a halogen atom bonded via a hetero atom), and Q ² represents a divalent linking group via —CO— or —CO—. The heteroatom is preferably a nonmetallic atom, and specifically includes an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom. Examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom.

X ¹ is preferably a monovalent group bonded through a hetero atom. Examples of monovalent groups bonded through a hetero atom include a hydroxyl group, a substituted oxy group (R ₅ O—), a mercapto group, a substituted thio group (R ₇ S—), an amino group, a substituted amino group (R ₈ NH— , R ₉ R ₁₀ N—), sulfo group, sulfonate group, substituted sulfinyl group (R ₁₂ —SO—), substituted sulfonyl group (R ₁₃ —SO ₂ —), phosphono group, substituted phosphono group, phosphonato group, substituted phosphonate Represents a group, a nitro group, or a heterocyclic group (which is linked by a heteroatom).

The divalent linking group bonded through a heteroatom exemplified as X ² may be any divalent linking group that can be linked to a polyol residue or a residue of an epoxy ester of a polyol. Compound residue, diester compound residue, monoalcohol monoester compound residue, monoamine monoalcohol compound residue, monoamine monoester compound residue, monothiol monoalcohol compound residue, monothiol monoester compound residue, monocarbamoyl mono Examples include alcohol compound residues, monocarbamoyl monoester compound residues, monoester monoalcohol compound residues, and the like.

Q ¹ is —CN or —COX, and X is preferably a monovalent group bonded through a heteroatom. Examples of monovalent groups bonded through a hetero atom include a hydroxyl group, a substituted oxy group (R ₅ O—), a mercapto group, a substituted thio group (R ₇ S—), an amino group, a substituted amino group (R ₈ NH— , R ₉ R ₁₀ N—), sulfo group, sulfonate group, substituted sulfinyl group (R ₁₂ —SO—), substituted sulfonyl group (R ₁₃ —SO ₂ —), phosphono group, substituted phosphono group, phosphonato group, substituted phosphonate A group, a nitro group, and a heterocyclic group (which are linked by a heteroatom).

The divalent linking group bonded via —CO— mentioned as Q ² may be any divalent linking group that can be linked to a polyol residue or a residue of an epoxy ester of a polyol. Diol compound residue, diester compound residue, monoalcohol monoester compound residue, monoamine monoalcohol compound residue, monoamine monoester compound residue, monothiol monoalcohol compound residue, monothiol monoester compound residue, monocarbamoyl Examples include a monoalcohol compound residue, a monocarbamoyl monoester compound residue, a monoester monoalcohol compound residue, and the like.

R ^a and R ^b are each independently, more preferably a hydrogen atom, a halogen atom, a cyano group, or an organic residue, which may have a substituent and may contain an unsaturated bond. Hydrogen group, substituted oxy group (R ₅ O—), substituted thio group (R ₇ S—), substituted amino group (R ₈ NH—, R ₉ R ₁₀ N—), substituted carbonyl group (R ₁₁ —CO—) Represents a carboxylate group, and R ^a and R ^b may be bonded to each other to form a cyclic structure.

Next, examples of each of the above-described substituents in X ¹ , Q ¹ , R ^a and R ^b in the general formula (I) are shown.
Examples of the “hydrocarbon group which may have a substituent and may contain an unsaturated bond” include an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkenyl group, a substituted alkenyl group and an alkynyl group. And substituted alkynyl groups.

  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, Pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s-butyl, 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.

The substituted alkyl group is composed of a bond between a substituent and an alkylene group, and as the substituent, a monovalent nonmetallic atomic group excluding hydrogen is used. Preferred examples include halogen atoms (—F, —Br, -Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkyl Carbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-ali Rucarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′- Dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl- N-alkylureido group, N′-alkyl-N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl- N-alkylureido group, N′-aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′- Diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, Acyl group (R ₄ CO—), carboxyl group and its conjugate base group (hereinafter referred to as carboxylate), alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group N-arylcarbamoyl group, N, N- Substituted sulfinyl groups (R ₁₂ —SO—) such as diarylcarbamoyl groups, N-alkyl-N-arylcarbamoyl groups, alkylsulfinyl groups and arylsulfinyl groups, alkylsulfonyl groups, arylsulfonyl groups, sulfo groups (—SO ₃ H) And conjugated base groups thereof (hereinafter referred to as sulfonate groups), alkoxysulfonyl groups, substituted sulfonyl groups such as aryloxysulfonyl groups (R ₁₃ —SO ₂ —), sulfinamoyl groups, N-alkylsulfinamoyl groups, N, N -Dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfur group Amoiru group, N, N- diaryl sulfamoyl group, N- alkyl -N- arylsulfamoyl group, N- acylsulfamoyl group and a conjugate base group, N- alkylsulfonylsulfamoyl group (-SO ₂ NHSO ₂ (alkyl)) and its conjugate base group, N-arylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (allyl)) and its conjugate base group, N-alkylsulfonylcarbamoyl group (—CONHSO ₂ (alkyl)) And its conjugate base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (allyl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl group (—Si (Oallyl) ₃ ) Hydroxysilyl group (—Si (OH) ₃ ) and its conjugate base group, Phono group (—PO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonato group), dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (—PO ₃ (aryl) ₂ ) Alkylarylphosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonate group), monoaryl Phosphono group (—PO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as arylphosphonate group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugated base group (hereinafter referred to as phosphonatoxy group) , dialkylphosphono group _{(-OPO 3 (alkyl) 2)} , diaryl phosphono group _{(-OPO 3 (aryl) 2)} , alkyl aryl phosphites Nookishi group (-OPO ₃ (alkyl) (aryl)), monoalkyl phosphono group (-OPO ₃ H (alkyl)) and its conjugated base group (hereinafter referred to as alkylphosphonato group), monoarylphosphono Examples thereof include an oxy group (—OPO ₃ H (aryl)) and a conjugated base group thereof (hereinafter referred to as an arylphosphonatooxy group), a cyano group, a nitro group, an aryl group, an alkenyl group, and an alkynyl group.

  Specific examples of the alkyl group in these substituents include the above-described alkyl groups, and specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a mesityl group, and a cumenyl group. , Fluorophenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl Group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, phenoxycarbonylphenyl group, N-phenylcarbamoyl group Group, a phenyl group, nitrophenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, and the like phosphonium Hona preparative phenyl group. Examples of alkenyl groups include vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group, and the like. Examples of alkynyl groups include ethynyl group, 1 -Propynyl group, 1-butynyl group, trimethylsilylethynyl group, phenylethynyl group and the like.

The above-described acyl group (R ₄ CO-), R ₄ is a hydrogen atom and the above alkyl group, aryl group, alkenyl group, and an alkynyl group. On the other hand, examples of the alkylene group in the substituted alkyl group include a divalent organic residue obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. Can include linear alkylene groups having 1 to 12 carbon atoms, branched alkylene groups having 3 to 12 carbon atoms, and cyclic alkylene groups having 5 to 10 carbon atoms. Specific examples of preferred substituted alkyl groups include chloromethyl, bromomethyl, 2-chloroethyl, trifluoromethyl, methoxymethyl, methoxyethoxyethyl, allyloxymethyl, phenoxymethyl, methylthiomethyl, Ruthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N- Methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, methoxycarbonylmethyl group, methoxycarbonylbutyl group, ethoxycarbonyl Bonylmethyl group, butoxycarbonylmethyl group, allyloxycarbonylmethyl group, benzyloxycarbonylmethyl group, methoxycarbonylphenylmethyl group, trichloromethylcarbonylmethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N- Methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group, sulfopropyl group, sulfobutyl group, sulfonatobutyl group, sulfur Famoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphono Eniru) sulfamoyl-octyl group,

  Phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, Phosphonatooxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, and the like.

  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, acenaphthenyl group, and fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable.

  The substituted aryl group is a group in which the substituent is bonded to the aryl group, and those having a monovalent non-metallic atomic group excluding hydrogen as a substituent on the ring-forming carbon atom of the aryl group described above are used. Examples of preferred substituents include the above-described alkyl groups, substituted alkyl groups, and those previously shown as substituents in the substituted alkyl group. Preferred examples of these substituted aryl groups include biphenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, fluorophenyl group, chloromethylphenyl group, trifluoromethylphenyl group, Hydroxyphenyl, methoxyphenyl, methoxyethoxyphenyl, allyloxyphenyl, phenoxyphenyl, methylthiophenyl, tolylthiophenyl, phenylthiophenyl, ethylaminophenyl, diethylaminophenyl, morpholinophenyl, acetyl Oxyphenyl group, benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, acetylaminophenyl group, N-methylbenzoyl Minophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-methylcarbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) ) Carbamoylphenyl group, N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfa Moylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, phosphonophenyl group, phosphonatophenyl group, diethylphosphonophenyl group, diph Nylphosphonophenyl group, methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonophenyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallylphenyl group 2-methylpropenylphenyl group, 2-propynylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group, and the like.

  Examples of the alkenyl group include those described above. The substituted alkenyl group is a group in which the substituent is replaced and bonded to a hydrogen atom of the alkenyl group, and as the substituent, the substituent in the above-mentioned substituted alkyl group is used, while the alkenyl group uses the above-mentioned alkenyl group. Can do. Examples of preferred substituted alkenyl groups include

等をあげることができる。

Etc.

  Examples of the alkynyl group include those described above. The substituted alkynyl group is a group in which the substituent is replaced with a hydrogen atom of the alkynyl group, and the substituent in the above-described substituted alkyl group is used as this substituent, while the alkynyl group uses the above-described alkynyl group. be able to.

The heterocyclic group is a monovalent group obtained by removing one hydrogen on the heterocyclic ring and a group formed by bonding one substituent to the above-mentioned substituted alkyl group by further removing one hydrogen from the monovalent group. It is a valent group (substituted heterocyclic group). Examples of preferred heterocycles include

等をあげることができる。

Etc.

The substituted oxy group (R ₅ O-), it can be used R ₅ is a monovalent nonmetallic atom group exclusive of hydrogen. Preferred substituted oxy groups include alkoxy groups, aryloxy groups, acyloxy groups, carbamoyloxy groups, N-alkylcarbamoyloxy groups, N-arylcarbamoyloxy groups, N, N-dialkylcarbamoyloxy groups, N, N-diarylcarbamoyloxy groups. Group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, phosphonooxy group, phosphonatoxy 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. Examples of the acyl group (R ₆ CO—) in the acyloxy group include those in which R ₆ is the aforementioned alkyl group, substituted alkyl group, aryl group, and substituted aryl group. Among these substituents, an alkoxy group, an aryloxy group, an acyloxy group, and an arylsulfoxy group are more preferable. Specific examples of preferred substituted oxy groups include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, pentyloxy, hexyloxy, dodecyloxy, benzyloxy, allyloxy, phenethyloxy, Carboxyethyloxy group, methoxycarbonylethyloxy group, ethoxycarbonylethyloxy group, methoxyethoxy group, phenoxyethoxy group, methoxyethoxyethoxy group, ethoxyethoxyethoxy group, morpholinoethoxy group, morpholinopropyloxy group, allyloxyethoxyethoxy group, Phenoxy, tolyloxy, xylyloxy, mesityloxy, cumenyloxy, methoxyphenyloxy, ethoxyphenyloxy, chlorophenyloxy, bromo Niruokishi group, acetyloxy group, benzoyloxy group, naphthyloxy group, a phenylsulfonyloxy group, a phosphonooxy group, phosphonatoxy and the like.

As the substituted thio group (R ₇ S—), those in which R ₇ is a monovalent nonmetallic atomic group excluding hydrogen can be used. Examples of preferred substituted thio groups include alkylthio groups, arylthio groups, alkyldithio groups, aryldithio groups, and acylthio groups. Alkyl group in these alkyl groups described above as the aryl group, a substituted alkyl group, and aryl group, those can be mentioned as shown as the substituted aryl group, R ₆ acyl group in the acylthio group (R ₆ CO-) in As described above. Among these, an alkylthio group and an arylthio group are more preferable. Specific examples of preferred substituted thio groups include a methylthio group, an ethylthio group, a phenylthio group, an ethoxyethylthio group, a carboxyethylthio group, and a methoxycarbonylthio group.

As the substituted amino group (R ₈ NH—, R ₉ R ₁₀ N—), those in which R ₈ , R ₉ and R ₁₀ are monovalent nonmetallic atomic groups excluding hydrogen can be used. Preferred examples of the substituted amino group include an N-alkylamino group, an N, N-dialkylamino group, an N-arylamino group, an N, N-diarylamino group, an N-alkyl-N-arylamino group, an acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N′-alkyl-N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-a Reel-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkylureido Group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino Group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group. Examples of these alkyl groups and aryl groups include the alkyl groups, substituted alkyl groups, aryl groups, and substituted aryl groups described above, such as acylamino groups, N-alkylacylamino groups, and N-arylacylamino groups. R ₆ acyl group (R ₆ CO-) in the group is as previously described. Of these, more preferred are an N-alkylamino group, an N, N-dialkylamino group, an N-arylamino group, and an acylamino group. 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.

As the substituted carbonyl group (R ₁₁ —CO—), those in which 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, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group can be mentioned. 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. Among these, more preferred substituted carbonyl groups include formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-ary. And a more preferable one is a formyl group, an acyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group. 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.

As the substituted sulfinyl group (R ₁₂ —SO—), those in which 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.

As the substituted sulfonyl group (R ₁₃ —SO ₂ —), those in which R ₁₃ is a monovalent nonmetallic atomic group can be used. More preferable examples include an alkylsulfonyl group and an arylsulfonyl 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. Specific examples of such a substituted sulfonyl group include a butylsulfonyl group and a chlorophenylsulfonyl group.

As described above, the sulfonate group (—SO ₃ ⁻ ) means a conjugate base anion group of the 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.).

As described above, the carboxylate group (—CO ₂ ⁻ ) means a conjugate base anion group of the 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.).

  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+ and the} like).

Of the substituents phosphonato group foregoing substituted phosphono group, but was replaced a hydroxyl group on one organic oxo group is the conjugate base anion group, as specific examples, the aforementioned monoalkyl phosphono 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+ and the} like).

Next, examples of a cyclic structure formed by combining R ^a and R ^b or X ¹ and R ^a or R ^b with each other will be shown. Examples of the aliphatic ring formed by combining R ^a and R ^b or X ¹ and R ^a or R ^b include 5-membered, 6-membered, 7-membered and 8-membered aliphatic rings. More preferred examples include 5-membered and 6-membered aliphatic rings. These may further have a substituent on the carbon atom constituting them (examples of the substituent include the above-mentioned substituents on the substituted alkyl group), and ring-constituting carbons. May be substituted with a hetero atom (oxygen atom, sulfur atom, nitrogen atom, etc.). Furthermore, a part of the aliphatic ring may form a part of the aromatic ring.

Next, the cationic group and anionic group of Z in the general formula (I) will be described.
Cationic groups include onium salt substituents. Preferable specific examples include an ammonium base, a sulfonium base, and an iodonium base, and more preferably an ammonium base.
The ammonium base refers to a salt of a primary amine and an acid, a salt of a secondary amine and an acid, a salt of a tertiary amine and an acid, and a quaternary ammonium salt. Examples of the acid mentioned here include inorganic acids such as hydrochloric acid, hydrobromic acid and sulfuric acid, and organic acids such as sulfonic acid, carboxylic acid and phosphonic acid.
On the other hand, examples of the anionic group include an organic acid group or a salt thereof. Preferred organic acid groups include carboxylic acid, sulfonic acid, and phosphonic acid, and examples of salts include salts with primary amines, salts with secondary amines, salts with tertiary amines, and quaternary ammonium salts. Or an inorganic salt typified by a lithium salt, a sodium salt, or a potassium salt. More preferred are carboxylic acids or organic salts of carboxylic acids.

As the compound represented by the formula (I) described above, it is preferable to use a compound of Group A or Group B exemplified below.

In the above formula, R ^a , R ^b , X ¹ , X ² , Q ¹ , and Q ² are as defined in general formula (I).
In addition, as a halogen atom of X ^{2 in} the above formula (4) showing one of the structures of Rp, for example, a fluorine atom, a chlorine atom, an oxygen atom or the like can be mentioned, and as an alkoxyl group, a carbon atom can be used. Examples are an alkoxyl group of 1 to 3 and the like.

In the polymerization compounds contained in the polymerizable substance groups A1 to A11 and B1 to B4 having the general formula shown above, specifically, the compound represented by the following formula as a compound in which A is represented by the general formula (III) Examples include compounds AX1-1 to BX4-1.

The previously exemplified polymerizable compounds AX10-1, AX10-2 and the like can be produced by adding an amine having a carboxyl group to the vinyl group of acrylic acid, that is, a broad amine acid. That is, it is generally represented by the following formula.
_{HOOC-R-NH 2 + CH} 2 = CH-COO-G
_{→ HOOC-R-NHCH 2 CH} 2 -COO-G
(“G” means a residue of the compound represented by A10.)
Here, R is a methylene group in the case of the polymerizable compound AX10-1, and a phenylene group in the case of the AX10-2. Examples of the amine having a carboxyl group used in this method include paraaminobenzoic acid, glycine, valine, leucine, isoleucine, serine, threonine, methionine, and phenylalanine. In addition, substances having equivalent performance can be derived from amino acids having two carboxyl groups such as glutamic acid and aspartic acid.

Further, specific examples of the compound in which A in Formula (I) is represented by Formula (II) include the following compounds AY1-1 to BY4-1.

The polymerizable compounds AY10-1 and AY10-2 exemplified above can be produced by adding an amine having a carboxyl group to the vinyl group of acrylic acid, that is, a broad amine acid. That is, it is generally represented by the following formula.
_{HOOC-R-NH 2 + CH} 2 = CH-COO-G
_{→ HOOC-R-NHCH 2 CH} 2 -COO-G
(“G” means a residue of the compound represented by A10.)
Here, R is a methylene group in the case of the polymerizable compound AY10-1, and a phenylene group in the case of AY10-2. Examples of the amine having a carboxyl group used in this method include paraaminobenzoic acid, glycine, valine, leucine, isoleucine, serine, threonine, methionine, and phenylalanine. In addition, substances having equivalent performance can be derived from amino acids having two carboxyl groups such as glutamic acid and aspartic acid.

(Water-soluble photopolymerization initiator that generates radicals by the action of radiation)
The polymerization initiator that can be used for the radiation-curable water-soluble polymerizable composition described above will be described. As an example, for example, a catalyst having a wavelength of up to about 400 nm may be mentioned. As such a catalyst, for example, a photopolymerization initiator represented by the following general formula (hereinafter abbreviated as TX type) which is a substance having a functionality in a long wavelength region, that is, a sensitivity to generate a radical upon receiving ultraviolet rays. In the present invention, it is particularly preferable to select and use them appropriately.

In the general formulas TX-1 to TX-3, R2 represents — (CH ₂ ) _x — (x = 0 or 1), —O— (CH ₂ ) _y — (y = 1 or 2), substituted or unsubstituted Represents a phenylene group. When R2 is a phenylene group, at least one hydrogen atom in the benzene ring is, for example, a carboxyl group or a salt thereof, a sulfonic acid or a salt thereof, a linear or branched alkyl having 1 to 4 carbon atoms. May be substituted with one or more groups or atoms selected from a group, a halogen atom (fluorine, chlorine, bromine, etc.), an alkoxyl group having 1 to 4 carbon atoms, an aryloxy group such as a phenoxy group, and the like. . M represents a hydrogen atom or an alkali metal (for example, Li, Na, K, etc.). R3 and R4 each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group. Examples of the alkyl group include, for example, a linear or branched alkyl group having about 1 to 10 carbon atoms, particularly about 1 to 3 carbon atoms. Moreover, as an example of the substituent of these alkyl groups, a halogen atom (a fluorine atom, a chlorine atom, an oxalic atom etc.), a hydroxyl group, an alkoxyl group (C1-C3 grade) etc. are mentioned, for example. M represents an integer of 1 to 10.

  Thioxanthone substituted with these hydrophilic atomic groups is water-soluble and co-soluble with an anionic aqueous pigment dispersion, and is less affected by the absorption of the organic pigment itself. Therefore, it is a highly sensitive catalyst in pigment-based compositions. Works.

Further, in the present invention, a water-soluble derivative (hereinafter abbreviated as an IC system) of a photopolymerization initiator Irgacure 2959 (trade name: manufactured by Ciba Specialty Chemicals) having the following general formula may be used. Specifically, IC-1 to IC-3 having the following formulas can be used.

  The above-described IC-1 to IC-3 are nonionic, but the wavelength region that can be sensitive to ultraviolet rays is shorter than the photopolymerization initiators shown as TX-1 to TX-3 mentioned above. In the area. IC-1 to IC-3 are also water-soluble like the above-described TX-1 to TX-3, and thus are useful as polymerization initiators for the water-soluble polymerizable compound of the present invention. Furthermore, it is considered possible to produce an aqueous derivative from a catalyst material (photopolymerization initiator) for an existing ultraviolet polymerization system and use it as a photopolymerization initiator.

(Aqueous pigment dispersion)
The above-mentioned water-soluble polymerizable compound can be used as a main component of the ink composition of the present invention, but by containing a pigment which is a coloring material, a colored photocurable type that is cured by irradiation with ultraviolet rays or the like. It can be used as ink or photo-curing paint. At this time, it is preferable to use an aqueous pigment dispersion in which a pigment is uniformly dispersed in an aqueous medium as a coloring material and to mix it with a water-soluble polymerizable compound. As the aqueous pigment dispersion, it is particularly preferable to use an aqueous pigment dispersion in which a pigment is stably dispersed in water by an anionic functional group. For example, water-based gravure inks, water-based pigment dispersions for writing instruments, and pigment dispersions for conventionally known inkjet inks that are stable in nonionic or anionic systems can be applied as they are.

  Examples of pigment dispersions having an anionic dissociating group and dispersed using an alkali-soluble water-soluble polymer are disclosed in, for example, JP-A Nos. 5-247392 and 8-143802. A pigment dispersion dispersed with a surfactant having an anionic dissociating group is disclosed in JP-A-8-209048. Examples of the pigment dispersion encapsulated with a polymer and dispersed by imparting an anionic dissociative group to the surface thereof include JP-A-10-140065, JP-A-9-316353, and JP-A-9-151342. No. 9-104834 and No. 9-031360. Further, examples of the pigment dispersion in which the pigment is dispersed by bonding an anionic dissociation group to the pigment surface by a chemical reaction include dispersions as disclosed in USP 5,837,045 and USP 5,851,280. There is. In the ink of the present invention, any of the various pigment dispersions described above can be used as the ink coloring material.

  When the above-mentioned water-soluble polymerizable compound is used in an ink, it is not limited to the above-described pigment, but a dye may be used as a coloring material, and an ink containing a water-soluble dye in a dissolved state may be used. This is possible as long as fading due to irradiation does not cause a practical problem. In addition, a color material dispersion containing a disperse dye, an oil-soluble dye or the like in a dispersed state can be applied in the same manner as the above-described pigment dispersion. These are appropriately selected according to the application.

  When a pigment is used as the coloring material of the ink composition according to the present invention, it is necessary to use a pigment dispersion in which the pigment is dispersed in a fine particle state in the medium. In particular, as a basic element of a pigment dispersion that can be suitably used for ink jet recording ink, the pigment is dispersed in an aqueous medium, and the particle size distribution as the dispersion is in the range of 25 nm to 350 nm in average particle diameter. And the viscosity of the final ink can be adjusted within a range that does not affect the ejection, and further, the constituents of the water-soluble polymerizable compound of the present invention, which are essential for making the ink ultraviolet curable, It is necessary to satisfy the compatibility. Below, each constituent material which can be used for the pigment dispersion suitable in this invention is demonstrated.

<Pigment>
As the organic pigment having a hue as a process color used in the color ink, the following can be appropriately used. Examples of the yellow pigment include Pigment Yellow 1, Pigment Yellow 2, Pigment Yellow 3, Pigment Yellow 12, Pigment Yellow 13, Pigment Yellow 14, Pigment Yellow 16, Pigment Yellow 17, Pigment Yellow 55, Pigment Yellow 73, and Pigment Yellow 74. Pigment Yellow 75, Pigment Yellow 83, Pigment Yellow 93, Pigment Yellow 95, Pigment Yellow 97, Pigment Yellow 98, Pigment Yellow 109, Pigment Yellow 110, Pigment Yellow 114, Pigment Yellow 128, Pigment Yellow 138, Pigment Yellow 139, Pigment Yellow 150, pigment yellow 151, pigment yellow 154, Pigment Yellow 155 and Pigment Yellow 180, and the like.

  Examples of magenta pigments include, for example, Pigment Red 5, Pigment Red 7, Pigment Red 12, Pigment Red 48 (Ca), Pigment Red 48 (Mn), Pigment Red 57: 1, Pigment Red 57 (Sr), and Pigment Red 57: 2, Pigment Red 122, Pigment Red 123, Pigment Red 168, Pigment Red 184, Pigment Red 202, Pigment Red 238, and the like.

  Examples of cyan pigments include Pigment Blue 1, Pigment Blue 2, Pigment Blue 3, Pigment Blue 16, Pigment Blue 22, Pigment Blue 60, Pigment Blue 15: 2, Pigment Blue 15: 3, Bat Blue 4 and Bat Blue 60. Etc.

<Particle diameter of pigment in ink>
The average particle diameter of the pigment particles is in the range of about 25 nm to 200 nm. Although this range depends on the use of the printed matter, it is sufficiently smaller than the wavelength of visible light, so that a printed matter that can be said to be sufficiently transparent is provided if the scattering is small.

<Color dyes>
The ink composition containing the above-described water-soluble polymerizable compound is prepared by attaching the ink composition to a recording medium (recording paper or the like) and then ultraviolet-curable resin (polymerizable material) in the ink by ultraviolet rays. It is preferable to polymerize and cure. As described above, when a dye is used as a coloring material, unlike the case of using the above-described pigment, it cannot be used without any fading due to ultraviolet irradiation, and is somewhat faded. For this reason, when a dye is applied as the colorant of the ink, it is preferable to use a so-called azo metal-containing dye, which forms a complex with metal ions, because there is little fading due to light. However, if the level of fading is not a problem, even a general water-soluble dye can be used at least as an ink composition. On the premise of this, the dye species applicable in the sense of having a process color color are the following compounds.

  Examples of the yellow dye include Acid Yellow 11, Acid Yellow 17, Acid Yellow 23, Acid Yellow 25, Acid Yellow 29, Acid Yellow 42, Acid Yellow 49, Acid Yellow 61, Acid Yellow 71, Direct Yellow 12, Direct Yellow 24 Direct Yellow 26, Direct Yellow 44, Direct Yellow 86, Direct Yellow 87, Direct Yellow 98, Direct Yellow 100, Direct Yellow 130, Direct Yellow 132, Direct Yellow 142, and the like.

  Examples of magenta red dyes include Acid Red 1, Acid Red 6, Acid Red 8, Acid Red 32, Acid Red 35, Acid Red 37, Acid Red 51, Acid Red 52, Acid Red 80, Acid Red 85, and Acid. Red 87, Acid Red 92, Acid Red 94, Acid Red 115, Acid Red 180, Acid Red 254, Acid Red 256, Acid Red 289, Acid Red 315, Acid Red 317, Direct Red 1, Direct Red 4, Direct Red 13 , Direct Red 17, Direct Red 23, Direct Red 28, Direct Red 31, Direct Red 62, Direct Red 79, Direct Red 81, Die Kutoreddo 83, Direct Red 89, Direct Red 227, Direct Red 240, Direct Red 242 and Direct Red 243, and the like, and the like.

  Examples of cyan dyes include Acid Blue 9, Acid Blue 22, Acid Blue 40, Acid Blue 59, Acid Blue 93, Acid Blue 102, Acid Blue 104, Acid Blue 113, Acid Blue 117, Acid Blue 120, and Acid Blue 167. Acid Blue 229, Acid Blue 234, Acid Blue 254, Direct Blue 6, Direct Blue 22, Direct Blue 22, Direct Blue 25, Direct Blue 71, Direct Blue 78, Direct Blue 86, Direct Blue 90, Direct Blue 106 and Direct Blue 199, etc. Is mentioned. A preferable concentration of the dye in the ink is in the range of 0.1 to 10% by mass. In the case where the density is low, for example, it is preferably applied to a so-called light ink of density-modulated ink.

<Prescription for clear ink>
The above-mentioned water-soluble polymerizable compound can be made into a clear ink by making it into the form of a transparent water-based ink without containing the above-mentioned coloring material. In particular, if it is prepared so as to have ink jet recording characteristics, a clear ink for water-based photocurable ink jet recording can be obtained. If such an ink is used, a clear film can be obtained because it does not contain a color material. Clear inks that do not contain color materials can be used for undercoats to give recording materials suitable for image printing, or for surface protection of images formed with ordinary inks, further decoration and gloss The use etc. for the overcoat for the purpose of provision etc. are mentioned. In the clear ink, colorless pigments or fine particles that are not intended for coloring can be dispersed and contained according to these applications. By adding these, it is possible to improve various properties such as image quality, fastness, and workability (handling property) of the printed matter in both the undercoat and the overcoat.

  Prescription conditions for application to such a clear ink include 10 to 85% of a water-soluble polymerizable compound as a main component of the ink, a photopolymerization initiator (for example, an ultraviolet polymerization catalyst), and the above water-soluble polymerization. It is preferable to prepare such that 1 to 10 parts by mass with respect to 100 parts by mass of the active compound and at least 0.5 part of the photopolymerization initiator is simultaneously contained with respect to 100 parts of ink.

  The prescription of the clear ink includes the prescription examples shown in Table 1 below using the polymerizable substance and the photopolymerization initiator as described above.

Table 1

In Table 1, the specific structures of TX-1 ′ and TX-2 ′ are as shown below. In the following structural formula, R2 represents — (CH ₂ ) _x — (x = 0 or 1), —O— (CH ₂ ) _y — (y = 1 or 2), or a substituted or unsubstituted phenylene group. M represents a hydrogen atom or an alkali metal (Li, Na, etc.), and R3 and R4 each independently represents a linear or branched alkyl group having about 1 to 3 carbon atoms.

<Reactive diluent component>
As described above, when the above-described water-soluble polymerizable composition is used for a clear ink, an aqueous polymerization-reactive low-viscosity monomer can be contained as a solvent. The advantage of using these substances, rather than ordinary solvents, is that these substances do not remain as plasticizers in the solid after reaction cured with UV light, thus reducing the impact on solid physical properties. is there. Examples of the reactive diluent component selected for such purpose include, for example, acryloylmorpholine used in the examples listed above, N-vinyl pyrrolidone, acrylamide, methylene bisacrylamide, monosaccharide monoacrylate, Examples thereof include compounds such as monoethylene acrylate of oligoethylene oxide and monoacrylate of dibasic acid.

<Solvent component>
Further, when the above-mentioned water-soluble polymerizable compound is used for a clear ink, it is particularly preferable not to use a solvent that imparts moisture retention, which has been conventionally used for water-based inkjet inks. This is because the clear ink does not contain a solid component such as a pigment, so that the viscosity is small, and even if there is a slight viscosity increase, it can be easily recovered. Of course, it is permissible to add more highly moisturizing solvents as described below. These can be selected from a large number of compounds conventionally used in aqueous inkjet.

  When the above-mentioned water-soluble polymerizable compound is used for ink, a solvent component can be added to the ink. The solvent component is added for the purpose of imparting non-volatility to the ink, lowering the viscosity, and imparting wettability to the printing substrate. In the case of printing on a non-absorbent substrate, it is desirable not to include the solvent component in the ink but to include only water so that all of the polymerizable substance component is cured and solidified. .

  When the solvent component is added to the ink in an amount of 10% or more, the printed material (recording material) on which the image is formed has a certain absorbency in terms of the strength of the finally obtained ink film. Is required. That is, in the case of printing with a water-based gravure ink, a recording material imparted with constant wetting and permeability is used and forced drying is performed. Similarly, in the ink according to the present invention, when the solvent component is added to the ink in an amount of 10% or more, a pretreatment for imparting water-based ink acceptability to the printing medium is performed. In addition, it is desirable to perform a natural or forced drying treatment after the ink is UV-cured. Since various polymerizable substances disclosed in the present invention have a certain moisture retention (inhibition of water evaporation and water absorption) by themselves, it is possible to form an ink completely excluding the solvent. In this case, measures such as capping, suction of fresh ink at the start of printing, and idle ejection may be used to ensure printing reliability at a practical level.

  Listed below are water-soluble organic solvents that can be used in the water-based ink of the present invention and can be evaporated and dried relatively easily. In the ink of the present invention, a solvent arbitrarily selected from these organic solvents can be added. For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoallyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol Examples thereof include glycol ethers such as monomethyl ether and dipropylene glycol monomethyl ether, and monohydric alcohols.

<Material structure of colorant-containing ink>
When the above-described water-soluble polymerizable compound is used in an ink containing a color material, it is preferable to adjust the concentration of the catalyst and the polymerizable substance in the ink in accordance with the absorption characteristics of the color material contained. As described above, the amount of water or solvent is in the range of 40% to 90%, preferably 60% to 75%, based on mass, as the blending amount. Further, the content of the ultraviolet polymerizable compound in the ink is in the range of 1% to 30%, preferably in the range of 5% to 20% on the mass basis with respect to the total amount of the ink. Although the polymerization catalyst depends on the content of the ultraviolet polymerizable compound, it is generally in the range of 0.1 to 7%, preferably 0.3 to 5% on the mass basis with respect to the total amount of the ink.

  When a pigment is used as the color material of the ink, the concentration of the pure pigment in the ink is generally in the range of 0.3% by mass to 10% by mass with respect to the total amount of the ink. The coloring power of the pigment depends on the dispersion state of the pigment particles, but if it is in the range of about 0.3 to 1%, it becomes a range used as a light-colored ink. On the other hand, if it is more than that, it gives a concentration used for general color coloring. The concentration of the pigment dispersion also depends on the viscosity and flow characteristics required by the printing apparatus. In the case of an on-demand ink jet apparatus, there is no nonlinearity in a wide range of viscosity, and the upper limit is 15 mN / m. In the case where the ink dots are fine high density and high drive frequency nozzles, the upper limit is 10 mN / m.

<Ink creation method>
Since all of the above-mentioned water-soluble polymerizable compounds have an acidic functional group, it is desirable to neutralize and dissociate with a base in order to dissolve in water. Therefore, it is usually adjusted from neutral to basic by alkali metal, alcohol amine, ammonia, morpholine, piperidine, etc., and then dissolved in water. At this time, the use of a compound having a primary or secondary amino group may be avoided because addition of a polymerizable substance to a double bond (Michael addition) may occur even in an aqueous solution. Good. Since this reaction is inhibited by polar groups, the reaction proceeds very little as long as water is present in a large amount. Therefore, the extent to which the use of compounds having primary and secondary amino groups should be avoided depends on the shelf life guarantee of the composition.

  The ink may be mixed with the raw materials to be used in any order. However, in order to ensure stability during mixing, it is preferable to adjust in advance so that all materials are neutral to basic. . In mixing, it is preferable to stir quickly so as not to maintain a non-uniform state for a long time. When a pigment dispersion is used as the coloring material, it is preferable that the mixture is further stirred after mixing so as not to impair the uniformity.

  The standard of the density | concentration of each component material in the case of setting it as the composition which contained the coloring material in the water-soluble polymeric compound mentioned above, especially the ink for inkjet recording is as follows. The pigment is used in an amount of 0.3 to 10% based on the total mass of the ink, the polymerizable material is used in an amount of 5.0 to 30%, and the catalyst is used in the range of 1 to 10% based on the mass of the polymerizable material. In addition, it is preferable to contain at least 1% in the ink.

<Printer system>
In the ink described above, a water-soluble organic solvent can be used as an optional component as described above. However, when it is used, it is preferably 5 to 20% on a mass basis with respect to the total amount of the ink. . Further, a surfactant for controlling ink wetting and permeation, a preservative, and a stabilizer for suppressing a thermal dark reaction can be added. If these additives are added to the water-soluble polymerizable compound as the main component of the ink, it is not necessary to add them, but if they are not added, they may be added depending on the application.

  As a method and apparatus suitable for recording using the ink described above, for example, a method and apparatus for applying thermal energy corresponding to a recording signal to ink in a recording head chamber and generating droplets by the thermal energy. And a printer system described in JP-A-2002-187918.

<Light irradiation lamp>
Hereinafter, an ultraviolet irradiation lamp used for curing a water-soluble polymerizable compound particularly suitable in the present invention will be described. The ultraviolet irradiation lamp is preferably a so-called low-pressure mercury lamp, high-pressure mercury lamp, mercury lamp coated with a phosphor, or the like whose mercury vapor pressure is 1 to 10 Pa during lighting. The emission spectrum of these mercury lamps in the ultraviolet region is in the range of 184 nm to 450 nm, and is suitable for efficiently reacting a polymerizable substance in black or colored ink. Also, a small power supply can be used for mounting the power supply in the printer, which is also suitable in that sense. As mercury lamps, for example, metal halide lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, xenon flash lamps, deep UV lamps, lamps that excite mercury lamps from the outside using microwaves, UV lasers, and the like are in practical use. Since the wavelength range includes the above range, it is basically applicable if the power source size, input intensity, lamp shape, etc. are allowed. The light source is selected according to the sensitivity of the catalyst used.
In the present invention, an LED light source in the UV region of 250 nm to 450 nm is also preferable.

The necessary UV integrated intensity is preferably about 500 to 5,000 mJ / cm ² in terms of the polymerization rate. When the integrated irradiation amount is insufficient, the adhesion force of the fixed ink to the recording paper cannot be exhibited sufficiently. Further, in color recording, the printed ink layer is insufficient in the fastness that is the object of the present invention, such as insufficient water resistance.

  If the ink described above is used, after applying the ink to the recording material, the polymerizable substance in the ink is polymerized and cured by ultraviolet rays and fixed, thereby using a glossy ink layer, an image, and a pigment. However, a transparent ink layer and image, good drying speed, excellent image friction durability, and dye image ozone resistance and water resistance can be obtained. At the same time, deformation of the paper itself, such as curling and cockling, is suppressed, which is preferable for handling and storing them.

(Support)
In order to obtain a lithographic printing plate, which is one of the main objects of the present invention, it is desirable to provide an image forming layer containing the water-soluble polymerizable compound on a support having a hydrophilic surface. As the hydrophilic support, a conventionally known hydrophilic support used in a lithographic printing plate can be used without limitation. The support used is preferably a dimensionally stable plate, for example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc). , Copper, etc.), plastic films (for example, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.) Such as paper or plastic film laminated or vapor-deposited with metal, and known physical and chemical treatments suitable for the purpose of imparting hydrophilicity and improving the strength as necessary. May be applied.

  In particular, preferred supports include paper, polyester film or aluminum plate, among which dimensional stability is good, relatively inexpensive, and a surface with excellent hydrophilicity and strength is provided by surface treatment as required. An aluminum plate which can be used is particularly preferred. A composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 is also preferable.

  A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. 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 at most 10% by weight. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, particularly preferably 0.2 mm to 0.3 mm.

  In the case of a support having a surface of metal, particularly aluminum, roughening (graining) treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluoride zirconate, phosphate, etc., or anodic oxidation treatment, etc. It is preferable that surface treatment is performed.

  The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, known methods such as a ball polishing method, a brush polishing method, a blast polishing method, a buffing method, and a polishing method can be used. In addition, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in an electrolytic solution such as hydrochloric acid or nitric acid. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used. Further, prior to roughening the aluminum plate, for example, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution, or the like is performed in order to remove rolling oil on the surface, if desired.

  Furthermore, an aluminum plate that has been roughened and then immersed in an aqueous sodium silicate solution can be preferably used. As described in Japanese Examined Patent Publication No. 47-5125, an aluminum plate which has been anodized and then immersed in an aqueous solution of an alkali metal silicate is preferably used. The anodizing treatment is carried out in an electrolytic solution in which an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid or boric acid, or an organic acid such as oxalic acid or sulfamic acid, or a salt solution thereof, or a combination of two or more thereof, is used. This is carried out by passing an electric current using the aluminum plate as an anode.

  Silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective. Furthermore, a combination of a support with electrolytic grains as disclosed in JP-B-46-27481, JP-A-52-58602, JP-A-52-30503, and the above-mentioned anodizing treatment and sodium silicate treatment Surface treatment is also useful. Further, those obtained by performing mechanical surface roughening, chemical etching, electrolytic graining, anodizing treatment, and sodium silicate treatment in this order as disclosed in JP-A-56-28893 are also suitable.

Furthermore, after performing these treatments, water-soluble resins such as polyvinylphosphonic acid, polymers and copolymers having sulfonic acid groups in the side chain, polyacrylic acid, water-soluble metal salts (for example, zinc borate) or Those having a primer such as a yellow dye or an amine salt are also suitable.
Further, a sol-gel treated substrate having a functional group capable of causing an addition reaction by a radical as disclosed in Japanese Patent Application No. 5-304358 is also preferably used.

  As another preferred example, a substrate provided with a water-resistant hydrophilic layer as a surface layer on an arbitrary support can be raised. As such a surface layer, for example, a layer comprising an inorganic pigment and a binder described in US Pat. No. 3,055,295 or JP-A-56-13168, a hydrophilic swelling layer described in JP-A-9-80744, and JP-T 8- Examples thereof include sol-gel films composed of titanium oxide, polyvinyl alcohol, silicic acids described in No. 507727.

  These hydrophilic treatments are performed to make the surface of the support hydrophilic, in order to prevent harmful reaction of the photopolymerizable composition provided thereon, and to improve the adhesion of the photosensitive layer. It is given for the purpose.

The lithographic printing plate of the present invention can be obtained by applying a solution prepared by dissolving the above-described composition containing the water-soluble polymerizable compound in water onto the support.
The concentration of the solid content in the coating solution is suitably 2 to 50% by weight.

The coating amount of the support for the image forming layer mainly affects the sensitivity of the photosensitive layer, the developability, the strength and the printing durability of the exposed film, and is preferably selected as appropriate according to the application. When the coating amount is too small, the printing durability is not sufficient. On the other hand, if the amount is too large, the sensitivity is lowered, it takes time for exposure, and a longer time is required for development processing, which is not preferable. As is the principal object lithographic printing plate for scan exposure of the present invention, the coating amount in the range of about 0.1 g / m ² ~ about 10 g / m ² in weight after drying is suitable. More preferably from 0.5 to 5 g / m ^2.
As said drying conditions, it is preferable to dry for 10 to 120 second in the temperature range of 50-130 degreeC.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.
Example 1
[Ink set 1]
As coloring materials, four types of dispersions of Pigment Yellow 155, Pigment Red 122, Pigment Blue 15: 3, and Pigment Black 7 were used, and the compositions shown in Table 2 below were used. Ink set 1 was produced. In this composition, the polymerizable compound AY3-1 having the structure shown above and belonging to the polymerizable substance group A3 and the water-soluble photopolymerization initiator TX-2 (1) having the structure shown below were used. In preparing each ink constituting the ink set 1, the polymerizable compound and the water-soluble photopolymerization initiator (catalyst) were each mixed with an aqueous solution whose pH was adjusted to 8.0 with triethanolamine in advance. Further, after adding all the components, the pH of the ink was finally set to 8.5.

上記Ink 1を構成する各インクに使用した顔料分散体

*:分散剤としてアクリル系アルカリ可溶型水溶性高分子を使用 Table 2
Prescription (unit: part) of each ink in ink set 1 (Ink 1) according to the embodiment

Pigment dispersion used for each ink constituting Ink 1

*: Acrylic alkali-soluble water-soluble polymer is used as a dispersant

Comparative Example 1
A comparative ink set 1 was produced in exactly the same manner as in Example 1, except that the polymerizable compound AY3-1 was replaced by the polymerizable compound T-1 represented by the following formula.

(Printing Example 1 and Printing Comparative Example 1)
The following tests were carried out using the ink set 1 and the comparative ink set 1 composed of the four color inks obtained as described above.

<Inkjet image recording>
A device in which three ultraviolet lamps were arranged at the paper discharge position of a commercially available Bubble Jet (registered trademark) printer BJF-850 was prepared, and the following printing test was performed. The center emission wavelength of the lamp is 365 nm, and the intensity at the irradiation position is 12 mW / cm ² . The time during which the printed medium is irradiated with ultraviolet rays is 30 seconds.

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

<Evaluation of inkjet image>
Next, for each formed image, the sensitivity required for curing, permeability in a commercially available glossy paper for water-based inkjet (GP-301 manufactured by Canon), and a grained aluminum support were used in accordance with the method described below. Ink bleeding, adhesion, printing durability, and storage stability were evaluated.

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

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

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

(Evaluation of adhesion in grained aluminum support)
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 is observed even in the cross cut test. Δ: Some peeling of the ink is recognized in the cross cut test, but almost no peeling is observed unless the ink surface is 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, then the ink viscosity was measured, and the increase in the ink viscosity was expressed as the viscosity ratio after storage / before storage. If the viscosity does not change and is close to 1.0, the storage stability is good, and if it exceeds 1.5, clogging may occur at the time of injection, which is not preferable.
These evaluation results are shown in Table 3.

Table 3.

  From Table 3, it can be seen that the α-heteromethacrylic compound-containing aqueous ink composition of the present invention gives good results both in image-forming properties on paper and when used as a printing plate. Further, the ink composition of the present invention has high sensitivity, high image quality and good storage stability, and exhibits high printing durability when used in a printing plate.

Claims (4)

An ink composition for ink jet recording that can be cured by radiation irradiation, comprising at least one colorant and at least one water-soluble polymerizable compound, wherein the water-soluble polymerizable compound is represented by the following general formula (I): An ink composition for ink jet recording , which is a compound represented by

In the formula (I), R is a residue of a polyol or a residue of an epoxy ester of a polyol, Z represents a cationic group or an anionic group, k is 2 to 6, L is 1 or 2 is there. In formula (II) or (III), R ^a and R ^b each independently represent a hydrogen atom, a halogen atom, a cyano group or an organic residue, and X ¹ is a group bonded via an oxygen atom. -valent radicals, X ² represents a divalent linking group via an oxygen atom or an oxygen atom, Q ¹ is -CN or -COX (X is a monovalent group or a halogen bonded through a hetero atom Q ² represents a divalent linking group via —CO— or —CO—. X ¹ and Q ² , R ^a and R ^b , or X ¹ and R ^a or R ^b may be bonded to each other to form a cyclic structure. The ink composition for ink jet recording according to claim 1, wherein the water-soluble polymerizable compound is any of the following polymerizable compound groups A1 to A11 or B1 to B4.

In the above formula, R ^a , R ^b , X ¹ , X ² , Q ¹ and Q ² are as defined in claim 1. The ink composition for ink jet recording according to claim 1 or 2 is ejected onto a hydrophilic support, irradiated with radiation, and cured to form a hydrophobic image, thereby forming a lithographic printing plate that does not require development processing. A method for producing a lithographic printing plate, characterized in that A radiation curable lithographic printing plate having an image forming layer containing the ink composition for ink jet recording according to claim 1 on a hydrophilic support.