JP2012233025A - Inkjet recording ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording ink composition excellent in photopolymerization reactivity and curability by an active energy ray and improved in odor.SOLUTION: The inkjet recording ink composition comprises: at least one selected from an ester of (meth)acrylic acid or amide monomer, which has a vinyl group derived from an acrylic acid on one or both terminals, wherein the (meth)acrylic acid or a residue forming the ester or amide has one or more sulfoxide group or sulfone group; and (II) a polymerization initiator.

Description

  The present invention relates to an ink composition for ink jet recording that is cured by active energy rays.

There are various methods for forming an image on a recording medium such as paper, such as an electrophotographic method, a sublimation recording method, a thermal transfer recording method, and an ink jet recording method. Among them, the electrophotographic method requires a process of forming an electrostatic latent image by charging and exposing on a photoreceptor, and finally fixing a toner on paper, and the entire system is very complicated. Since many supplies are required, the cost is increased and the maintenance load is increased.
In addition, the sublimation recording method and thermal transfer recording method require a supply such as a sublimation ribbon and thermal transfer ribbon in addition to the recording medium such as paper, so the system is also a simpler recording method than the electrophotographic method. . However, since both types use an ink ribbon in which an ink component is applied on the entire surface of a support such as a PET film, the ink ribbon corresponding to the non-image portion is also consumed, and the actual running cost increases. In addition, since an ink ribbon (so-called husk) is generated after use, problems with waste generation and confidentiality arise.

In contrast, the ink-jet recording method is simple and consumes ink only for the necessary parts. Therefore, the ink consumption efficiency is high and resource saving is superior compared to the thermal transfer recording method described above. Ink cost per unit recording can be kept low. Although the ink jet recording method has such features, when an image is formed on an absorbent medium such as plain paper using water-based ink, the print dots are likely to blur and the image quality changes depending on the medium. In addition, since the water resistance of the ink is not sufficient, an image flows due to contact with water. Furthermore, when printing an image with a high printing rate, there are problems such as the occurrence of curling of the paper due to curling and the inability to stack the paper immediately after printing due to poor drying. Has been a major obstacle in the use of. In addition, printing on non-permeable recording media typified by various films such as PET film is also a limitation of printing paper, and its practical range is narrowed.
Under these circumstances, an ink jet recording method using a solvent-type ink using a quick-drying organic solvent instead of water has appeared. However, since a highly volatile organic solvent is used as the ink solvent, the flammability is high. In addition to the danger of handling, the organic solvent evaporates during the printing and drying process, so there are concerns about adverse effects on the health of the operator who performs printing and on the environment due to release to the atmosphere. Further, since a volatile organic solvent is used, clogging due to ink solidification around the head tends to occur, and there is a problem in maintenance of the apparatus.

Therefore, in recent years, an ink jet recording method using an active energy ray-curable ink that can be cured by an active energy ray has attracted attention. For example, the ultraviolet curable ink jet recording method using ultraviolet rays as the active energy rays is excellent in quick drying without evaporation of the solvent, so that it solves the problems in the environment and the health of the operator due to the volatile solvent, Ink solidification due to solvent evaporation hardly occurs, and it is excellent in maintainability of ink peripheral devices such as a head. Furthermore, printing can be performed not only on permeable recording media such as plain paper and various ink-jet exclusive paper (receiving paper) but also on non-permeable recording media such as various films.
Also, in terms of equipment, it is sufficient if there is a light source that can output active energy rays such as ultraviolet rays, so it can be said that this is a simple mechanism compared to drying by heat and recovery of the evaporated organic solvent. Further, by using an LED lamp as a light source, further energy saving can be achieved, and a significant reduction in environmental load can be expected.

The ink composition used in such an active energy ray curable ink jet recording system is described in various books, literatures, etc. as an ultraviolet curable ink composition, and usually contains a polymerization initiator and a monomer as essential components and is necessary. Depending on the above, components such as pigments, oligomers, polymers, and sensitizers are blended, and the description of books such as Non-Patent Documents 1 and 2 can be given as an example.
As described above, the monomer component constituting the ink uses a plurality of monomers in view of curing speed (sensitivity), ink viscosity, cured film characteristics, and the like, and has a low molecular weight monomer having low viscosity and excellent reactivity. In many cases, a multifunctional and high molecular weight monomer is used in combination. Since the monomer is a main component that occupies nearly 80% by weight of the ink composition for inkjet recording, in addition to the material development, development relating to its blending (combination) is also being actively conducted.

  For example, using a trifunctional or higher functional (meth) acrylic acid ester or amide compound having an alkylene oxide group in the molecule for the purpose of achieving both curability and flexibility after curing (Patent Document 1), Combining a trifunctional or higher functional (meth) acrylic acid ester or amide having an alkylene oxide group with a monofunctional (meth) acrylic acid ester or amide having a C 6-12 alkyl moiety (Patent Document 2), etc. Proposed. Furthermore, an aliphatic (meth) acrylate compound having a secondary hydroxyl group and a compound having a nitrogen atom and a polymerizable unsaturated bond in the molecule for the purpose of achieving both curability and adhesion between the cured image and the recording medium. (Patent Document 3), and a polymerizable compound having a polymerizable unsaturated bond and an amino group in the molecule (Patent Document 4) has been proposed. In addition, by using a monomer having an alkylene oxide structure, a hydroxyl group, an amino group, or a structure containing an atom having a high electronegativity such as an oxygen atom or a nitrogen atom, the flexibility of the film after curing and the recording medium Attempts have been made to improve the adhesion.

On the other hand, Non-Patent Document 3 reports that the reactivity of radical polymerization is increased by the heteroatom of the sulfide structure (—S—) or the ether structure (—O—) introduced as a structure in the monomer compound. In relation to this, an inkjet ink composition using a compound containing a sulfide structure or a disulfide structure in the molecule as a polymerizable compound has been proposed (Patent Documents 5 and 6), and due to the presence of the sulfide structure in the molecule, It is said that radical polymerization is likely to proceed even in air (in the presence of oxygen) and the aim is to improve curability.
Furthermore, for the purpose of improving the hydrophilicity of the monomer material and the dispersibility of the pigment, a sulfonic acid structure, a sulfonic acid ester structure (Patent Documents 7 and 8), a phosphoric acid structure, and a phosphoric acid ester structure (Patent Documents 9 and 10). Various monomer compounds that contain benzene in the molecular structure have also been proposed.

Further, when such an ink composition is used, its odor (odor) also becomes an important issue in the working environment. In general, UV curable ink compositions for ink jet recording based on reactive monomers contain a large amount of low-molecular-weight reactive monomers called diluents as reactive monomers that also serve as solvents. The ink physical properties are kept in an appropriate state. Such low molecular weight monomer compounds typified by (meth) acrylates often have a specific odor and give discomfort.
In general, the odor of a chemical substance is recognized by human detection of the compound molecules scattered in the air, so that the compound itself has a unique odor, such as a monomer compound. It is important in terms of suppressing odor that it is difficult to scatter in the air. Therefore, for example, increasing the molecular weight of the monomer compound or strengthening the intermolecular interaction by introducing a polar functional group has the effect of suppressing the scattering of the monomer compound in the air, improving the odor. It will be one of the ways to do this.

  However, when an ink is prepared using only a high molecular weight monomer compound, the viscosity becomes high and the reactivity as a monomer is lowered. In addition, the high viscosity itself is suitable for an ink composition for inkjet. Absent. Moreover, although the low molecular weight monomer compound described in the above-mentioned known literature having a highly polar functional group such as a hydroxyl group or an amino group is expected to improve the problem of odor, it is difficult to say that this alone is sufficient. Furthermore, when there are free functional groups that easily form hydrogen bonds, such as hydroxyl groups and amino groups, the intermolecular interaction is very large and the viscosity becomes extremely high. It is difficult to say that it is sufficient in terms of satisfying the odor and reactivity required for the ink composition, and also the low viscosity.

  An object of the present invention is to provide an ink composition for ink jet recording which is excellent in photopolymerization reactivity and curability by active energy rays and has improved odor.

〔式（１）〜（３）中、Ｘはアルキル基、Ｙはアルキレン基、Ｗはアルキレン基である。但し、硫黄同士が直接結合する場合には、Ｗは存在しない。Ｚは酸素原子又は−ＮＲ２−（Ｒ２は水素原子又はアルキル基）で表わされる基であり、Ｒ１は水素原子又はアルキル基である。ｍは１又は２である。〕
２） 前記式（１）〜（３）におけるｍが２であることを特徴とする１）記載のインクジェット記録用インク組成物。
３） 前記式（１）のモノマーにおけるＸが炭素数１〜４のアルキル基であることを特徴とする２）記載のインクジェット記録用インク組成物。
４） 前記式（１）のモノマーが下記式（４）で表わされるものであることを特徴とする３）記載のインクジェット記録用インク組成物。

５） 前記式（３）のモノマーが下記式（５）で表わされるものであることを特徴とする２）記載のインクジェット記録用インク組成物。

As a result of intensive studies, the inventor introduced a specific functional group into the molecular structure of the (meth) acrylic acid ester compound and (meth) acrylic acid amide compound, thereby reducing the unpleasant odor of the monomer, It has been found that the reactivity to active energy rays and the curability are also excellent.
That is, the above-mentioned problems are solved by the following inventions 1) to 5).
1) (I) The residue represented by the following formulas (1) to (3), which forms an ester or amide with (meth) acrylic acid, has one or more sulfoxide groups or sulfone groups, and one end Or at least one selected from esters or amide monomers of (meth) acrylic acid having vinyl groups derived from acrylic acid at both ends, and (II) a polymerization initiator, Composition.

[In Formula (1)-(3), X is an alkyl group, Y is an alkylene group, W is an alkylene group. However, W does not exist when sulfur couples directly. Z is an oxygen atom or a group represented by —NR 2 — (R 2 is a hydrogen atom or an alkyl group), and R 1 is a hydrogen atom or an alkyl group. m is 1 or 2. ]
2) The ink composition for ink jet recording according to 1), wherein m in the formulas (1) to (3) is 2.
3) The ink composition for ink jet recording according to 2), wherein X in the monomer of the formula (1) is an alkyl group having 1 to 4 carbon atoms.
4) The ink composition for ink jet recording according to 3), wherein the monomer represented by the formula (1) is represented by the following formula (4).

5) The ink composition for ink jet recording according to 2), wherein the monomer represented by the formula (3) is represented by the following formula (5).

  ADVANTAGE OF THE INVENTION According to this invention, the ink composition for inkjet recordings which was excellent in the photopolymerization reactivity and sclerosis | hardenability by an active energy ray, and the odor improved can be provided.

Hereinafter, the present invention will be described in detail.
First, each component contained in the ink composition for ink jet recording of the present invention (hereinafter sometimes referred to as “ink composition”) will be described.
<(Meth) acrylic acid ester or amide monomer of (I)>
The monomer used in the ink composition of the present invention is represented by the formulas (1) to (3), and the residue that forms an ester or amide with (meth) acrylic acid has one or more sulfoxide groups or sulfone groups. And at least one selected from esters or amides of (meth) acrylic acid having a vinyl group derived from acrylic acid at one or both ends.
X in the formulas (1) to (3) is an alkyl group, preferably a linear or branched alkyl group having 1 to 4 carbon atoms. Y is an alkylene group, and a linear or branched alkylene group having 1 to 6 carbon atoms is preferable. W does not exist or is an alkylene group, and an alkylene group having 1 to 4 carbon atoms is preferable. Z is an oxygen atom or -NR2- group (R2 is a hydrogen atom or an alkyl group), preferably an oxygen atom. R1 is a hydrogen atom or a methyl group.

The monomers represented by the formulas (1) to (3) have a sulfoxy structure (—SO—) or a sulfone structure (—SO ₂ —), which is an aprotic polar functional group, in the molecular structure. The reactivity and curability are expected to be improved by the proximity of the reactive monomers and the distance between the polymerizable sites due to the intermolecular interaction caused by the appropriate polarity due to these structures. A characteristic of these polar groups is that they do not contain hydrogen atoms, and the resulting intermolecular interaction has a higher degree of freedom of molecular motion than the interaction through hydrogen bonds. In addition, since it is a compound having a relatively small molecular weight and the viscosity of these monomers tends to be suppressed, the monomer (I) can be said to be suitable for an ink composition.

Preferred specific examples of the monomer (I) are shown below.

The content of the monomer (I) in the ink composition of the present invention is preferably 20 to 98% by weight, more preferably 30 to 90% by weight, and particularly preferably 30 to 80% by weight.
Moreover, only 1 type may be used for the monomer of (I) and it may use it in combination of 2 or more type.

<(II) Polymerization initiator>
As the polymerization initiator in the ink composition of the present invention, a radical polymerization initiator, a cationic polymerization initiator, and an anionic polymerization initiator can be used. In combination with the monomer (I), the radical polymerization initiator is used. And anionic polymerization initiators are preferable, and radical polymerization initiators are particularly preferable.
The polymerization initiator can be appropriately selected according to the type of monomer and the intended use of the ink composition. The polymerization initiator used in the ink composition of the present invention is a compound that absorbs external energy and generates a polymerization initiating species. External energy used for initiating polymerization is roughly divided into heat or active energy rays, and a thermal polymerization initiator or a photopolymerization initiator is used, respectively. Examples of active energy rays include γ rays, β rays, electron beams, ultraviolet rays, visible rays, and infrared rays. Moreover, a well-known compound can be used as a thermal-polymerization initiator and a photoinitiator.
Preferred radical polymerization initiators include (a) aromatic ketones, (b) acylphosphine oxide compounds, (c) aromatic onium salt compounds, (d) organic peroxides, (e) thio compounds, (f) hexa An arylbiimidazole compound, (g) a ketoxime ester compound, (h) a borate compound, (i) an azinium compound, (j) a metallocene compound, (k) an active ester compound, (l) a compound having a carbon halogen bond, (m ) Alkylamine compounds and the like. These radical polymerization initiators may be used alone or in combination of two or more.

Specific examples of the radical polymerization initiator include benzophenone, Michler's ketone, 4,4'-bis (diethylamino) benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy- 2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxyacetophenone, 2,2- Dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-ben Ru-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-di (t-butylperoxycarbonyl) benzophenone 3,4,4′-tri (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra ( t-hexylperoxycarbonyl) benzophenone, 3,3'-di (methoxycarbonyl) -4,4'-di (t-butylperoxycarbonyl) benzophenone, 3,4'-di (methoxycarbonyl) -4,3'- Di (t-butylperoxycarbonyl) benzophenone, 4,4'-di (methoxycarbonyl) -3,3 -Di (t-butylperoxycarbonyl) benzophenone, 1,2-octanedione, 1- [4- (phenylthio) phenyl] -2- (o-benzoyloxime), 2- (4'-methoxystyryl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (3 ′, 4′-dimethoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (2 ′, 4′-dimethoxystyryl) ) -4,6-bis (trichloromethyl) -s-triazine, 2- (2'-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4'-pentyloxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 4- [p-N, N-di (ethoxycarbonylmethyl)]-2,6-di (trichloromethyl) -s -Triazine, 1,3-bis (trichloromethyl) -5- (2'-chlorophenyl) -s-triazine, 1,3-bis (trichloromethyl) -5- (4'-methoxyphenyl) -s-triazine, 2- (p-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) benzthiazole, 2-mercaptobenzothiazole, 3,3′-carbonylbis (7-diethylaminocoumarin), 2- (o-chlorophenyl) ) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2-chlorophenyl) -4,4', 5,5'-tetrakis (4-ethoxy) Carbonylphenyl) -1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4,4 ', 5,5'-tetrapheny -1,2'-biimidazole, 2,2'-bis (2,4-dibromophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'- Bis (2,4,6-trichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 3- (2-methyl-2-dimethylaminopropionyl) carbazole, 3, 6-bis (2-methyl-2-morpholinopropionyl) -9-n-dodecylcarbazole, 1-hydroxycyclohexyl phenyl ketone, bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6- ^{difluoro-3-(1} H- pyrrol-1-yl) - phenyl) titanium, bis (2,4,6-trimethylbenzoyl) phenyl phosphine oxide, 2,4,6-trimethyl Reuben benzoyl diphenyl phosphine oxide, and the like.

  Among them, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (IRGACURE 819 manufactured by Ciba Japan) or 2,4,6-trimethylbenzoyldiphenylphosphine oxide (DAROCUR TPO manufactured by Ciba Japan): Product name), 1-hydroxycyclohexyl phenyl ketone (IRGACURE 184: trade name, manufactured by Ciba Japan), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Ciba Japan) IRGACURE 907 (trade name), 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (manufactured by Ciba Japan) IRGACURE 379: trade name) is an ink composition The ink composition is preferable because it is highly compatible with other components contained in the product and can be cured with a small amount of ultraviolet irradiation.

The polymerization initiator is preferably in the range of 1 to 50% by weight, preferably 2 to 40% by weight, based on the total weight of the monomer (I) and other polymerizable compounds and colorants described later used as optional components. The range is more preferable, and the range of 5 to 30% by weight is still more preferable. When the polymerization initiator and the sensitizer described later are used in combination, the weight ratio of the polymerization initiator: sensitizer is preferably 200: 1 to 1: 200, more preferably 50: 1 to 1:50. Range.
In addition to the components described above, other components can be used in combination with the ink composition of the present invention for the purpose of improving physical properties, as long as the effects of the present invention are not impaired. Hereinafter, these optional components will be described.

<Colorant>
The ink composition of the present invention may contain a colorant, whereby a colored image can be formed. There is no restriction | limiting in particular about a coloring agent, It can select suitably from arbitrary well-known coloring agents, such as a pigment, an oil-soluble dye, a water-soluble dye, and a disperse dye.
As the colorant, a pigment or an oil-soluble dye having excellent weather resistance and high color reproducibility is preferable, and a pigment is more preferable. Further, the colorant that can be suitably used in the ink composition of the present invention is a compound that does not function as a polymerization inhibitor for the polymerization reaction that is a curing reaction, from the viewpoint of not reducing the sensitivity of the curing reaction by active energy rays. It is preferable to select.
Although it does not necessarily limit as a pigment which can be used for this invention, For example, the organic or inorganic pigment of the following number described in a color index is mentioned, It can select suitably according to the objective and can be used.

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

The oil-soluble dye that can be used in the present invention will be described. The oil-soluble dye as used herein means a dye that is substantially insoluble in water. Specifically, the solubility in water at 25 ° C. (the weight of the dye that can be dissolved in 100 g of water) is 1 g or less, preferably 0.5 g or less, more preferably 0.1 g or less. Therefore, the oil-soluble dye means a water-insoluble pigment or oil-soluble dye, and among these, an oil-soluble dye is preferable.
Among oil-soluble dyes, yellow dyes include, for example, phenols, naphthols, anilines, pyrazolones, pyridones, aryl or heteryl azo dyes having open-chain active methylene compounds as coupling components, and open chains as coupling components. Azomethine dyes having an active methylene compound, methine dyes such as benzylidene dyes and monomethine oxonol dyes, quinone dyes such as naphthoquinone dyes, anthraquinone dyes, etc., and other dye species include quinophthalone And dyes, nitro / nitroso dyes, acridine dyes, acridinone dyes and the like.

Among the oil-soluble dyes, magenta dyes include, for example, phenols, naphthols, aryl or heteryl azo dyes having coupling components, pyrazolones, azomethine dyes having pyrazolotriazoles, arylidene dyes as coupling components Methine dyes such as styryl dyes, merocyanine dyes, oxonol dyes, carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, quinone dyes such as naphthoquinone, anthraquinone, anthrapyridone, dioxazine dyes, etc. And condensed polycyclic dyes.
Among oil-soluble dyes, examples of cyan dyes include indoaniline dyes, indophenol dyes, or azomethine dyes having pyrrolotriazoles as coupling components, cyanine dyes, oxonol dyes, polymethine dyes such as merocyanine dyes, diphenylmethane dyes, Examples thereof include carbonium dyes such as triphenylmethane dyes and xanthene dyes, phthalocyanine dyes, anthraquinone dyes, aryl or heteryl azo dyes having phenols, naphthols and anilines as coupling components, and indigo / thioindigo dyes.
Preferable specific examples of the oil-soluble dye include C.I. I. Solvent Black 3, 7, 27, 29 and 34, C.I. I. Solvent Yellow 14, 16, 19, 29, 30, 56, 82, 93 and 162, C.I. I. Solvent Red 1, 3, 8, 18, 24, 27, 43, 49, 51, 72, 73, 109, 122, 132 and 218, C.I. I. Solvent Violet 3, C.I. I. Solvent Blue 2,11,25,35,38,67 and 70, C.I. I. Solvent Green 3 and 7, C.I. I. Solvent Orange 2 etc. are mentioned.

  In the present invention, disperse dyes can also be used as long as they are soluble in a water-immiscible organic solvent. I. Disperse Yellow 5,42,54,64,79,82,83,93,99,100,119,122,124,126,160,184: 1,186,198,199,201,204,224,237 , C.I. I. Disperse Orange 13, 29, 31: 1, 33, 49, 54, 55, 66, 73, 118, 119, 163, C.I. I. Disperse Red 54, 60, 72, 73, 86, 88, 91, 92, 93, 111, 126, 127, 134, 135, 143, 145, 152, 153, 154, 159, 164, 167: 1,177 , 181, 204, 206, 207, 221, 239, 240, 258, 277, 278, 283, 311, 323, 343, 348, 356, 362, C.I. I. Dispers Violet 33, C.I. I. Disperse Blue 56, 60, 73, 87, 113, 128, 143, 148, 154, 158, 165, 165: 1, 165: 2, 176, 183, 185, 197, 198, 201, 214, 224, 225 , 257, 266, 267, 287, 354, 358, 365, 368, C.I. I. Disperse Green 6: 1, 9 etc. are mentioned.

The colorant is preferably dispersed appropriately after being added to the ink composition. For dispersion, a ball mill, a sand mill, a ring mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, Each dispersing device such as 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 colorant. The type of the dispersant is not particularly limited, but a polymer dispersant is preferable. These dispersants are preferably added in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the colorant.
One or more colorants may be appropriately selected and used depending on the intended use of the ink composition. In the ink composition, when a colorant such as a pigment that exists as a solid is used, the average particle diameter of the colorant particles is preferably 0.005 to 0.5 μm, more preferably 0.01. It is preferable to set the selection of the colorant, the dispersant, and the dispersion medium, the dispersion conditions, and the filtration conditions so as to be -0.45 μm, and more preferably 0.015-0.4 μm. By controlling the particle size, it is preferable to suppress clogging of the head nozzle and maintain the storage stability, transparency and curing sensitivity of the ink.
The content of the colorant is appropriately selected depending on the purpose of use of the ink composition. However, considering the ink properties and colorability, generally the content of the colorant is 0.5 to 10 with respect to the total weight of the ink composition. It is preferable that it is weight%, and it is more preferable that it is 1 to 8 weight%. In the case of a white ink composition using a white pigment such as titanium oxide as a colorant, the content of the colorant is 5 to 5% of the total weight of the ink composition in order to ensure concealment. It is preferably 30% by weight, more preferably 10 to 25% by weight.

<Other polymerizable compounds (monomers)>
The ink composition of the present invention may contain a polymerizable compound other than the monomer (I). Examples of the polymerizable compound that can be used in combination include a radical polymerizable compound, a cationic polymerizable compound, and an anion polymerizable compound.
The radical polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization, and is not particularly limited as long as it is a compound having at least one ethylenically unsaturated bond capable of radical polymerization in the molecule. Monomer, oligomer And those having a chemical form such as a polymer. The radically polymerizable compounds used in combination may be used alone or in combination of two or more at any ratio in order to improve the desired properties.
Examples of the radical polymerizable compound include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, salts thereof, compounds derived therefrom, and ethylenically unsaturated groups. And radically polymerizable compounds such as unsaturated acrylonitrile, styrene, various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.

  Specifically, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, bis (4-acryloxypolyethoxyphenyl) propane, neopentyl glycol diacrylate, ethoxylation Neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, propylene Glycol diacrylate, dipropylene glycol diac Rate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate Acrylic acid derivatives such as N-methylolacrylamide, diacetoneacrylamide, epoxy acrylate, methyl methacrylate, n-butyl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, 1,6-hexanediol dimethacrylate, ethylene Methacryl such as recall dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane Derivatives, acrylamide derivatives such as 2-hydroxyethylacrylamide and acryloylmorpholine, and other derivatives of allyl compounds such as allyl glycidyl ether, diallyl phthalate, triallyl trimellitate, and the like. Commercially available products or known reactive monomers, oligomers and polymers described in materials such as photoreactive material data it can.

  Furthermore, it is also preferable to use a vinyl ether compound as the radical polymerizable compound. Suitable vinyl ether compounds include, for example, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, diethylene glycol divinyl ether, triethylene glycol monovinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol. Di- or trivinyl ether compounds such as divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, hydroxyethyl monovinyl ether, hydroxynonyl monovinyl ether, trimethylolpropane trivinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octade Monovinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexanedimethanol monovinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, isopropenyl ether-o-propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, octadecyl vinyl ether, etc. Examples include vinyl ether compounds. A vinyl ether compound may be used individually by 1 type, or may be used in combination of 2 or more type as appropriate.

Examples of other polymerizable compounds that can be used in the present invention include (meth) acrylic monomers or prepolymers, (meth) acrylic acid esters such as epoxy monomers or prepolymers, urethane monomers or prepolymers (hereinafter, as appropriate, (Referred to as an acrylate compound).
Specifically, 2-ethylhexyl diglycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxybutyl acrylate, hydroxypivalate neopentyl glycol diacrylate, 2-acryloyloxyethylphthalic acid, methoxypolyethylene glycol acrylate , Tetramethylol methane triacrylate, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, dimethylol tricyclodecane diacrylate, ethoxylated phenyl acrylate, 2-acryloyloxyethyl succinic acid, nonylphenol ethylene oxide adduct acrylate, modified Glycerin triacrylate, bisphenol A diglycidyl ether acrylic acid adduct, modified bisphenol A diacrylate, Noxypolyethylene glycol acrylate, 2-acryloyloxyethyl hexahydrophthalic acid, propylene oxide adduct diacrylate of bisphenol A, ethylene oxide adduct diacrylate of bisphenol A, dipentaerythritol hexaacrylate, pentaerythritol triacrylate tolylene diisocyanate Urethane prepolymer, lactone-modified flexible acrylate, butoxyethyl acrylate, propylene glycol diglycidyl ether acrylic acid adduct, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, 2-hydroxyethyl acrylate, methoxydipropylene glycol acrylate, Ditrimethylolpropane tetraacrylate, pentae Sri tall triacrylate hexamethylene diisocyanate urethane prepolymer, stearyl acrylate, isoamyl acrylate, isomyristyl acrylate, isostearyl acrylate, lactone-modified acrylate.

In addition, regarding the selection of the polymerization initiator and the polymerizable compound, in addition to the combination of the radical polymerizable compound and the radical polymerization initiator according to various purposes, the cationic polymerizable compound and the cationic polymerization start as shown below. It may be a radical / cation hybrid curable ink composition using an agent in combination, or a radical / anion hybrid curable ink composition using an anion polymerizable compound and an anionic polymerization initiator together.
The cationically polymerizable compound is not particularly limited as long as it is a compound that initiates a polymerization reaction with an acid generated from a photoacid generator and cures, and various known cationically polymerizable monomers known as photocationically polymerizable monomers are used. can do. Examples thereof include various epoxy compounds, vinyl ether compounds, oxetane compounds described in Non-Patent Document 1 and the like. As the cationic polymerization initiator (photoacid generator) used in combination with the cationic polymerizable compound, various known materials can be used, for example, aromatic onium compounds such as diazonium, ammonium, iodonium, sulfonium, phosphonium, and the like. of ^{_{B (C 6 F 5) 4}} -, PF 6 -, AsF 6 -, SbF 6 -, CF 3 SO 3 - salts, sulfonated materials that generate a sulfonic acid, halide that photogenerate a hydrogen halide, iron allene A complex etc. are mentioned. The said cationic polymerization initiator may be used independently and may use 2 or more types together.

  Examples of the anionic polymerizable compound include various epoxy compounds, lactone compounds, acrylic compounds, and methacrylic compounds. Among them, acrylic compounds and methacrylic compounds exemplified as the radical polymerizable compound are preferable. Examples of the anionic polymerization initiator include so-called photobase generators such as orthonitrobenzyl carbamate derivatives, orthoacyloxyl derivatives, orthocarbamoyloxime amidine derivatives, and the like.

<Sensitizer>
A sensitizer can be added to the ink composition of the present invention in order to promote decomposition of the polymerization initiator by irradiation with actinic rays. A sensitizer absorbs a specific active energy ray and becomes an electronically excited state. The sensitizer in an electronically excited state is brought into contact with the polymerization initiator to cause electron transfer, energy transfer, heat generation, etc., thereby causing a chemical change of the polymerization initiator (decomposition, generation of radical, acid or base). ). As the sensitizer, a compound corresponding to the wavelength of the active energy ray that generates an initiation species in the polymerization initiator may be used. As the sensitizer, a sensitizing dye is preferable, and examples thereof include those having an absorption wavelength in the 350 to 450 nm region as follows.
Polynuclear aromatics (eg pyrene, perylene, triphenylene), xanthenes (eg fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg thiacarbocyanine, oxacarbocyanine), merocyanines (eg , Merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones (eg, anthraquinone), squaliums (eg, squalium), coumarins (Eg 7-diethylamino-4-methylcoumarin)

<Co-sensitizer>
The ink composition of the present invention can also contain a co-sensitizer. The co-sensitizer has functions such as further improving the sensitivity of the sensitizing dye to the active energy ray and suppressing the inhibition of polymerization of the polymerizable compound by oxygen. Examples of cosensitizers include amine compounds such as triethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole. Thiols and sulfides such as 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, and β-mercaptonaphthalene, but are not limited thereto.

<Other ingredients>
If necessary, other components such as a polymerization inhibitor and a solvent can be added to the ink composition of the present invention. The polymerization inhibitor is added from the viewpoint of improving the storage stability (storage stability) of the ink composition. In addition, the ink composition of the present invention can be heated and reduced in viscosity as necessary to be ejected, and a polymerization inhibitor is preferably added to prevent clogging of the head due to thermal polymerization in that case. Examples thereof include hydroquinone, benzoquinone, p-methoxyphenol, TEMPO, TEMPOL, and cuperon Al. The addition amount of the polymerization inhibitor is preferably 200 to 20,000 ppm with respect to the total amount of the ink composition.
The ink composition of the present invention is preferably an active energy ray-curable ink composition and therefore preferably does not contain a solvent. However, in order to improve properties such as adhesion between the cured ink and the recording medium, the ink composition Only when there is no effect on the curing rate of the product, a solvent can be contained. An organic solvent or water can be used as the solvent. The content of the organic solvent is in the range of 0.1 to 5% by weight, preferably 0.1 to 3% by weight, based on the total weight of the ink composition.
Furthermore, as necessary, surfactants, leveling additives, matting agents, polyester resins, polyurethane resins, vinyl resins, acrylic resins, rubber resins, which are used for adjusting film properties, are known additives. Waxes and the like can be appropriately selected and added. Moreover, in order to improve the adhesiveness with respect to polyolefin, PET, etc., it is also possible to contain a tackifier (tack fire) without polymerization inhibition.

  The viscosity of the ink composition of the present invention is preferably 7 to 30 mPa · s, and more preferably 7 to 25 mPa · s in the environment during ejection in consideration of ejectability in the ink jet apparatus. In this case, the ink can be heated as necessary, and the viscosity of the ink can be controlled within an appropriate range by the heating temperature at that time.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited by these Examples. In the following examples, “%” is “wt%”.
In order to clarify the effect of the polymerizable compound (monomer) used in the present invention, the prepared ink composition was a composition that did not contain various additive components including a colorant.
¹ H-NMR was measured using ¹ H-NMR (500 MHz) manufactured by JEOL, and IR was measured using FT-IR Spectrum GX manufactured by PERKIN ELMER.

[Synthesis Example 1]
<Synthesis of 2-acryloxyethyl ethyl sulfoxide (A-03)>
Tungsten (IV) oxide (0.20 g) was added to distilled water (80 mL), and several drops of 50% aqueous sodium hydroxide solution were added to adjust the pH to 10-11. 6 and then 2- (ethylthio) ethanol (12.74 g, 120 mmol) was added. The obtained mixture was heated to about 60 ° C., and 30% hydrogen peroxide water (13.54 g, 0.99 eq) was slowly added dropwise while cooling so that the temperature inside the system became 60 to 67 ° C. After confirming that the reaction of the potassium iodide starch paper in the reaction solution was negative, filtration was performed, and the obtained filtrate was concentrated under reduced pressure. The concentrate was extracted with acetone (200 mL) and the extract was concentrated under reduced pressure and then extracted with ethyl acetate (100 mL). The extract was filtered and concentrated under reduced pressure to give 2-hydroxyethylethyl sulfoxide as a colorless oil (9.9 g). The yield is about 68%.
Next, 2-hydroxyethylethyl sulfoxide (3.05 g, 25 mmol) was added to dehydrated dichloromethane (70 mL), the inside of the flask was replaced with argon gas, and then triethylamine (3.64 g, 36 mmol) was added. After the mixture was cooled to about −10 ° C., acrylic acid chloride (2.72 g, 30 mmol) was slowly added dropwise so that the system temperature was −10 to −5 ° C., and then stirred at room temperature for 2 hours. did. The precipitate was removed by filtration, and the filtrate was washed with water, saturated aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride solution, dried over sodium sulfate, and concentrated under reduced pressure to give a yellow oil. The resulting oil was purified by column chromatography (Wakogel C300 200 g) to give a pale yellow oil (3.8 g). This pale yellow oil was confirmed to be 2-acryloxyethyl ethyl sulfoxide from ¹ H-NMR and IR below. The yield is about 86%.
¹ H-NMR (CDCl ₃ ) δ 1.37 (t, 3H), 2.74-2.86 (m, 2H), 2.93-2.99 (m, 1H), 3.02-3.08 (M, 1H), 4.54-4.59 (m, 1H), 4.63-4.68 (m, 1H), 5.89-5.91 (dd, 1H), 6.11-6 .17 (m, 1H), 6.44-6.47 (dd, 1H)
IR (NaCl) 3456, 2982, 2935, 1740, 1634, 1455, 1375, 1319, 1244, 1144, 1046, 1021, 942, 808, 644 cm ⁻¹

[Synthesis Example 2]
<Synthesis of 2-acryloxyethyl ethyl sulfone (C-03)>
Tungsten (IV) oxide (0.12 g) was added to distilled water (80 mL), and a few drops of 50% aqueous sodium hydroxide solution were added to adjust the pH to 10-11. 6 and then 2- (ethylthio) ethanol (4.43 g, 42 mmol) was added. The obtained mixture was heated to about 60 ° C., and 30% hydrogen peroxide solution (4.7 g, 0.99 eq) was slowly added dropwise while cooling so that the temperature inside the system became 60 to 65 ° C. The reaction mixture was reacted at 63 ° C. for about 1 hour, and it was confirmed that the reaction of the potassium iodide starch paper in the reaction solution was negative. The reaction mixture was then heated to about 75 ° C., and 30% aqueous hydrogen peroxide (4.73 g, 1.0 eq) was slowly added dropwise. The reaction solution after reacting the reaction mixture at about 75 ° C. for 2.5 hours showed a positive result in the reaction of potassium iodide starch paper. The heating was stopped, and sodium bisulfite was added until the reaction of potassium iodide starch paper in the reaction solution became negative. The reaction solution was filtered to remove insolubles, and the filtrate was concentrated under reduced pressure and extracted with ethyl acetate (200 mL). The extract was dried over sodium sulfate and concentrated under reduced pressure to give 2-hydroxyethylethylsulfone as a colorless oil (5.7 g). The yield is about 98%.
Next, 2-hydroxyethyl ethyl sulfone (3.45 g, 25 mmol) was added to dehydrated dichloromethane (70 mL), the inside of the flask was replaced with argon gas, and then triethylamine (3.64 g, 36 mmol) was added. After the mixture was cooled to about −10 ° C., acrylic acid chloride (2.72 g, 30 mmol) was slowly added dropwise so that the system temperature was −10 to −5 ° C., and then stirred at room temperature for 2 hours. did. The precipitate was removed by filtration, and the filtrate was washed with water, a saturated aqueous sodium hydrogen carbonate solution and a saturated aqueous sodium chloride solution, dried over sodium sulfate, and then concentrated under reduced pressure to give a brown oil. The resulting oil was purified by column chromatography (Wakogel C300 200 g) to give a pale yellow oil (3.3 g). This pale yellow oil was confirmed to be 2-acryloxyethyl ethyl sulfone by ¹ H-NMR and IR below. The yield is about 69%.
¹ H-NMR (CDCl ₃ ) δ 1.42 (t, 3H), 3.08 (q, 2H), 3.35 (t, 2H), 4.61 (t, 2H), 5.92-5. 94 (dd, 1H), 6.11-6.16 (m, 1H), 6.45-6.48 (dd, 1H)
IR (NaCl) 3617, 2985, 2945, 1728, 1635, 1621, 1459, 1410, 1317, 1273, 1187, 1128, 1075, 985, 809, 789, 730 cm ⁻¹

[Synthesis Example 3]
<Synthesis of 2-acryloxyethyl methyl sulfone (C-01)>
Tungsten (IV) oxide (0.12 g) was added to distilled water (80 mL), and a few drops of 50% aqueous sodium hydroxide solution were added to adjust the pH to 10-11. 6 and then 2- (methylthio) ethanol (3.87 g, 42 mmol) was added. The obtained mixture was heated to about 60 ° C., and 30% hydrogen peroxide solution (4.7 g, 0.99 eq) was slowly added dropwise while cooling so that the temperature inside the system became 60 to 65 ° C. The reaction mixture was reacted at 63 ° C. for about 1 hour, and it was confirmed that the reaction of the potassium iodide starch paper in the reaction solution was negative. The reaction mixture was then heated to about 75 ° C., and 30% aqueous hydrogen peroxide (4.73 g, 1.0 eq) was slowly added dropwise. The reaction solution after reacting the reaction mixture at about 75 ° C. for 2.5 hours showed a positive result in the reaction of potassium iodide starch paper. The heating was stopped, and sodium bisulfite was added until the reaction of potassium iodide starch paper in the reaction solution became negative. The reaction solution was filtered to remove insolubles, and the filtrate was concentrated under reduced pressure and extracted with ethyl acetate (200 mL). The extract was dried over sodium sulfate and concentrated under reduced pressure to give 2-hydroxyethylmethylsulfone as a colorless oil (4.90 g). The yield is about 94%.
Next, 2-hydroxyethyl methyl sulfone (6.21 g, 50 mmol) was added to dehydrated dichloromethane (70 mL), the inside of the flask was replaced with argon gas, and then triethylamine (7.3 g, 72 mmol) was added. After the mixture was cooled to about −10 ° C., acrylic acid chloride (5.43 g, 60 mmol) was slowly added dropwise so that the system temperature was −10 to −5 ° C., and then stirred at room temperature for 2 hours. did. The precipitate was removed by filtration, and the filtrate was washed with water, a saturated aqueous sodium hydrogen carbonate solution and a saturated aqueous sodium chloride solution, dried over sodium sulfate, and then concentrated under reduced pressure to give a brown oil. The obtained oil was purified by column chromatography (Wakogel C300 200 g) to give a pale yellow oil (7.0 g). This pale yellow oil was confirmed to be 2-acryloxyethyl methyl sulfone by ¹ H-NMR and IR below. The yield is about 79%.
¹ H-NMR (CDCl ₃ ) δ 3.00 (s, 3H), 3.39 (t, 2H), 4.63 (t, 2H) 5.93-5.95 (dd, 1H), 6.12 -6.17 (m, 1H), 6.45-6.49 (dd, 1H)
IR (NaCl) 3016, 2934, 1728, 1635, 1621, 1461, 1410, 1314, 1295, 1187, 1132, 1074, 984, 964, 809, 742, 665 cm ⁻¹

[Synthesis Example 4]
<Synthesis of 2-methacryloxyethyl ethyl sulfoxide (B-03)>
A pale yellow oil was obtained in the same manner as in Synthesis Example 1 except that methacrylic acid chloride was used instead of acrylic acid chloride in Synthesis Example 1. This pale yellow oil was confirmed to be 2-methacryloxyethyl ethyl sulfoxide from ¹ H-NMR and IR below. The yield is about 56%.
¹ H-NMR (CDCl ₃ ) δ 1.37 (t, 3H), 1.96 (s, 3H), 2.74-2.82 (m, 2H), 2.95-2.99 (m, 1H) ), 3.02-3.08 (m, 1H), 4.52-4.58 (m, 1H), 4.62-4.67 (m, 1H), 5.61-5.64 (m) , 1H), 6.14-6.16 (m, 1H)
IR (NaCl) 2977, 2934, 1721, 1637, 1455, 1404, 1377, 1321, 1297, 1161, 1055, 1021, 947, 815, 651 cm ⁻¹

[Synthesis Example 5]
<Synthesis of 2-methacryloxyethyl methyl sulfone (D-01)>
A pale yellow oil was obtained in the same manner as in Synthesis Example 3 except that methacrylic acid chloride was used instead of acrylic acid chloride in Synthesis Example 3. This pale yellow oil was confirmed to be 2-methacryloxyethyl methyl sulfone from ¹ H-NMR and IR below. Yield about 85%.
¹ H-NMR (CDCl ₃ ) δ 1.96 (t, 3H), 3.00 (s, 3H), 3.39 (t, 2H), 4.62 (t, 2H), 5.65-5. 67 (m, 1H), 6.13-6.15 (m, 1H)
IR (NaCl) 2933, 1722, 1637, 1455, 1407, 1315, 1295, 1165, 1131, 1068, 1017, 962, 814, 661 cm ⁻¹

[Synthesis Example 6]
<Synthesis of bis (2-acryloxyethyl) sulfoxide (F-01)>
Tungsten (IV) oxide (0.12 g) was added to distilled water (80 mL), and a few drops of 50% aqueous sodium hydroxide solution were added to adjust the pH to 10-11. 6 and then 2,2'-thiodiethanol (8.55 g, 70 mmol) was added. The obtained mixture was heated to about 60 ° C., and 30% hydrogen peroxide water (7.9 g, 0.99 eq) was slowly added dropwise while cooling so that the temperature inside the system was 60 to 67 ° C. After confirming that the reaction of the potassium iodide starch paper in the reaction solution was negative, filtration was performed, and the obtained filtrate was concentrated under reduced pressure. Acetone (200 mL) was added to the concentrate and washed to obtain colorless crystals (7.3 g) insoluble in acetone as bis (2-hydroxyethyl) sulfoxide. The yield is about 76%.
Next, bis (2-hydroxyethyl) sulfoxide (4.15 g, 30 mmol) was added to dehydrated dichloromethane (70 mL), and the flask was purged with argon gas, and then triethylamine (8.74 g, 86 mmol) was added. After the mixture was cooled to about −10 ° C., acrylic acid chloride (6.52 g, 72 mmol) was slowly added dropwise so that the system temperature was −10 to −5 ° C., and then stirred at room temperature for 2 hours. did. The precipitate was removed by filtration, and the filtrate was washed with water, a saturated aqueous sodium hydrogen carbonate solution and a saturated aqueous sodium chloride solution, dried over sodium sulfate, and then concentrated under reduced pressure to give a brown oil. The obtained oil was purified by column chromatography (Wakogel C300 200 g) to give a pale yellow oil (5.0 g). This pale yellow oil was confirmed to be bis (2-acryloxyethyl) sulfoxide from ¹ H-NMR and IR below. Yield about 68%
¹ H-NMR (CDCl ₃ ) δ 3.04-3.10 (m, 2H), 3.12-3.19 (m, 2H), 4.54-4.61 (m, 2H), 4.65 -4.70 (m, 2H), 5.89-5.92 (dd, 2H), 6.11-6.17 (m, 2H), 6.43-6.48 (dd, 2H)
IR (NaCl) 3442, 2961, 1726, 1635, 1620, 1455, 1409, 1297, 1269, 1189, 1046, 986, 810 cm ⁻¹

[Synthesis Example 7]
<Synthesis of bis (2-acryloxyethyl) sulfone (H-01)>
Tungsten (IV) oxide (0.16 g) is added to distilled water (100 mL), and a few drops of 50% aqueous sodium hydroxide are added to adjust the pH to 10-11. 6 and then 2,2′-thiodiethanol (12.2 g, 100 mmol) was added. The resulting mixture was heated to about 60 ° C., and 30% aqueous hydrogen peroxide (11.28 g, 0.99 eq) was slowly added dropwise while cooling the system so that the system temperature was 60 to 65 ° C. The reaction mixture was reacted at 63 ° C. for about 1 hour, and it was confirmed that the reaction of the potassium iodide starch paper in the reaction solution was negative. Subsequently, after heating the reaction mixture to about 75 ° C., 30% aqueous hydrogen peroxide (11.34 g, 1.0 eq) was slowly added dropwise. The reaction solution after reacting the reaction mixture at about 75 ° C. for 2.5 hours showed a positive result in the reaction of potassium iodide starch paper. The heating was stopped, and sodium bisulfite was added until the reaction of potassium iodide starch paper in the reaction solution became negative. The reaction solution was filtered to remove insolubles, and the filtrate was concentrated under reduced pressure and extracted with acetone (200 ml). The extract was dried over sodium sulfate and concentrated under reduced pressure to give bis (2-hydroxyethyl) sulfone as a colorless oil (15.0 g). The yield is about 97%.
Next, bis (2-hydroxyethyl) sulfone (3.75 g, 25 mmol) was added into dehydrated dichloromethane (70 mL), the inside of the flask was replaced with argon gas, and then triethylamine (7.29 g, 72 mmol) was added. After the mixture was cooled to about −10 ° C., acrylic acid chloride (5.43 g, 60 mmol) was slowly added dropwise so that the system temperature was −10 to −5 ° C., and then stirred at room temperature for 2 hours. did. The precipitate was removed by filtration, and the filtrate was washed with water, a saturated aqueous sodium hydrogen carbonate solution and a saturated aqueous sodium chloride solution, dried over sodium sulfate, and then concentrated under reduced pressure to give a brown oil. The resulting oil was purified by column chromatography (Wakogel C300 200 g) to give a pale yellow oil (3.9 g). The pale yellow oil was confirmed to be bis (2-acryloxyethyl) sulfone from ¹ H-NMR and IR below. The yield is about 59%.
¹ H-NMR (CDCl ₃ ) δ 3.45 (t, 4H), 4.62 (t, 4H), 5.91-5.94 (dd, 2H), 6.11-6.17 (m, 2H) ), 6.43-6.47 (dd, 2H)
IR (NaCl) 2990, 2937, 1728, 1635, 1621, 1457, 1411, 1323, 1296, 1271, 1184, 1127, 1072, 984, 809, 723 cm ⁻¹

[Reference Synthesis Example 1]
<Synthesis of 2-acryloxyethyl ethyl sulfide (Reference Example 1)>
A colorless oil was obtained in the same manner as in Synthesis Example 1 except that 2- (ethylthio) ethanol was used instead of 2-hydroxyethylethyl sulfoxide in Synthesis Example 1. This colorless oil was confirmed to be 2-acryloxyethyl ethyl sulfide shown in the following [Chemical Formula 14] from ¹ H-NMR and IR below. Yield about 83%.
¹ H-NMR (CDCl ₃ ) δ 1.28 (t, 3H), 2.61 (q, 2H), 2.80 (t, 2H), 4.32 (t, 2H), 5.84-5. 87 (dd, 2H), 6.11-6.16 (m, 2H), 6.41-6.45 (dd, 2H)
IR (NaCl) 2967, 2929, 1727, 1636, 1620, 1454, 1407, 1297, 1269, 1183, 1056, 983, 810, 666 cm ⁻¹

[Reference Synthesis Example 2]
<Synthesis of 2-methacryloxyethyl ethyl sulfide (Reference Example 2)>
A colorless oil was obtained in the same manner as in Reference Synthesis Example 1 except that methacrylic acid chloride was used instead of acrylic acid chloride in Reference Synthesis Example 1. This colorless oil was confirmed to be 2-methacryloxyethyl ethyl sulfide represented by the following [Chemical 15] from ¹ H-NMR and IR below. The yield is about 82%.
¹ H-NMR (CDCl ₃ ) δ 1.28 (t, 3H), 1.95-1.96 (dd, 3H), 2.61 (q, 2H), 2.80 (t, 2H), 4. 31 (t, 2H), 5.58-5.59 (m, 1H), 6.12-6.13 (m, 1H)
IR (NaCl) 2965, 2929, 1785, 1719, 1637, 1453, 1404, 1376, 1320, 1296, 1160, 1049, 1011, 975, 942, 814, 653 cm ⁻¹

Examples 1-7, Comparative Examples 1-3
950 mg of a monomer compound (compound described in Table 1), 50 mg of a polymerization initiator 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (IRGACURE-907 manufactured by Ciba Japan) A sample for evaluation was prepared by mixing the mixture in a ratio with a magnetic stirrer.
About these samples, the photopolymerization reactivity, photocurability, and the odor of the ink composition were evaluated as follows. The evaluation results are shown in Table 1.

<Evaluation of photopolymerization reactivity>
Evaluation of the photopolymerization reactivity of the sample for evaluation was performed using a measuring apparatus (hereinafter referred to as “Photo-DSC”) in which a SII DSC-7020 and a HAYASHI WATCH-WORKS spot light source (LA-410UV) were combined. In addition, the light of wavelength 365nm was used for irradiation light, and the light quantity was 200 mW / cm < ² >.
The calorific value associated with the polymerization reaction that proceeds after the light irradiation was measured by Photo-DSC. However, the calorific value when the light was irradiated for a sufficient time to complete the polymerization reaction of the monomer compound was measured for one sample. Repeated twice. The calorific value obtained by the first measurement includes the calorific value associated with light irradiation in addition to the calorific value associated with the polymerization reaction of the monomer compound. Therefore, the sample for which the polymerization reaction was completed in the first measurement was again irradiated with light under the same conditions, and the heat generation amount other than the polymerization reaction heat of the monomer was measured. And the calorific value accompanying the polymerization reaction of the monomer compound was obtained from the difference in calorific value between the first time and the second time.
In this exothermic characteristic, the time from the start of light irradiation until reaching the maximum calorific value was defined as T1 (sec.), Which was used as an index for comparing the speed of the photopolymerization reaction.

<Photocurability evaluation>
Evaluation of the curability by photopolymerization of the sample for evaluation was performed using a measuring device (hereinafter, Photo rheometer) in which a viscoelasticity measuring device VAR200AD made by REOLOGICA and an LED light source (LIGHTNINGCURE LC-L1) made by Hamamatsu Photonics were combined.
The measurement is performed by sandwiching a sample in a 10 μm gap using a φ20 mm cone plate, irradiating light (365 nm, 50 mW / cm ² ) using an LED as a light source, measuring a change in viscoelasticity due to curing, and measuring an elastic modulus ( Curing was terminated when Pa) was saturated. The reaching point of the elastic modulus was obtained from the measurement result and used as an index of the curing level. Usually, it can be said that it is at a level that is sufficiently cured at a level of 1 × 10 ⁴ (Pa). The light energy (curing energy) irradiated until the elastic modulus is saturated is calculated by the product of the irradiation light intensity (here, 50 mW / cm ² ) and the light irradiation time (sec.).

<Odor evaluation>
Discomfort when smelling the sample for evaluation (ink composition) was evaluated according to the following criteria.
[Criteria]
○: Almost no smell is felt and it is not uncomfortable.
X: Discomfort occurs due to a peculiar odor.
△: Between △ and △

As can be seen from Table 1, the inks of Examples 1 to 7 have a high elastic modulus after curing in photocuring property, and are excellent in photocuring property (solidified by light), and also have no problem of odor. It is excellent in practicality. In particular, the inks of Examples 2 and 5 to 7 have low light energy (curing energy) necessary for curing, and can be cured firmly with less energy, and Examples 5 and 7 are excellent. On the other hand, the photopolymerization reactivity is excellent in that the inks of Examples 2 to 7 have a small T1 (sec.) And the monomer polymerization reaction at the time of light irradiation proceeds rapidly, so that unreacted monomers hardly remain. Yes.
From this viewpoint, Comparative Examples 1 to 3 have unpleasant odors and are not suitable for practical use. Further, in Comparative Example 1, although the photopolymerization reactivity is excellent, the cured product after the polymerization reaction has a low elastic modulus and is insufficiently cured. Further, in Comparative Example 2, it is not cured at all after the polymerization reaction.

JP 2007-231231 A JP 2007-231233 A JP 2009-67926 A JP 2009-144057 A JP 2006-160824 A JP 2009-127030 A JP 2009-197126 A Japanese Patent No. 4576899 JP 2008-230216 A JP 2008-303260 A

Optical Application Technology / Material Encyclopedia (Edition Committee for Optical Application Technology / Material Encyclopedia, Industrial Technology Service Center, Inc., 2006) Latest optimization of UV curing resin (Technical Information Association, Inc., issued in 2008) Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 31, 2365-2371 (1993)

Claims (5)

(I) The residue which forms an ester or amide with (meth) acrylic acid represented by the following formulas (1) to (3) has one or more sulfoxide groups or sulfone groups, and one end or both An ink composition for ink jet recording comprising at least one selected from an ester or amide monomer of (meth) acrylic acid having a vinyl group derived from acrylic acid at a terminal, and (II) a polymerization initiator .

[In Formula (1)-(3), X is an alkyl group, Y is an alkylene group, W is an alkylene group. However, W does not exist when sulfur couples directly. Z is an oxygen atom or a group represented by —NR 2 — (R 2 is a hydrogen atom or an alkyl group), and R 1 is a hydrogen atom or an alkyl group. m is 1 or 2. ]   2. The ink composition for ink jet recording according to claim 1, wherein m in the formulas (1) to (3) is 2.   The ink composition for ink jet recording according to claim 2, wherein X in the monomer of the formula (1) is an alkyl group having 1 to 4 carbon atoms. The ink composition for ink jet recording according to claim 3, wherein the monomer represented by the formula (1) is represented by the following formula (4).

The ink composition for ink jet recording according to claim 2, wherein the monomer represented by the formula (3) is represented by the following formula (5).