JP2003221530A - Ink composition and method for recording image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition capable of carrying out high-quality printing even for paper and a water nonabsorbing material to be recorded and having excellent preservation stability and water and light resistances of the ink, and a method for recording an image using the ink composition. <P>SOLUTION: This ink composition comprises a monomer having a polymerizable group, an oil-soluble dye and a storage stabilizer. The oil-soluble dye is dissolved in the ink. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition containing an oil-soluble dye and curable by radiation, and an image recording method using the ink composition.

[0002]

2. Description of the Related Art A water-based ink composition is inferior in water resistance when printed on plain paper and is liable to cause bleeding. Further, when printed on a non-water-absorbent recording material such as plastic, There are drawbacks that images cannot be formed due to bad adhesion of droplets, that the drying of the solvent is extremely slow, it is necessary to dry the printed matter without overlapping the printed matter immediately after printing, and the images are easily blurred.

As a material suitable for printing on a non-water absorptive recording material, Japanese Patent Publication No. 2001-512777 discloses an ultraviolet curable ink using a polyfunctional monomer excellent in adhesiveness to a recording material. However, it was slow to dry due to the water-dispersed ink and was insufficient for forming a full-color image. In order to solve the drying property, a method of using a volatile organic solvent as a solvent of the ink has been carried out, but in order to dry quickly, it is highly flammable such as methyl ethyl ketone and ethanol, and has high volatility. It was necessary to use a solvent as the main component.

In order to solve these problems, JP-A-5-214279 discloses an ink jet ink which is cured and fixed by radiation instead of volatilization of the ink solvent. However, since the pigment dispersion is used as the coloring component, the nozzle is clogged due to the aggregation of the pigment, and it is difficult to stably eject the ink.

On the other hand, when a pigment is used as a colorant, it is difficult to obtain photographic image quality because the transparency is poor and the color tone is insufficient. As a means for solving the problem, an ultraviolet curable ink using a dye as a colorant is disclosed in US Pat.
No. 24, however, there is a problem that an unfavorable polymerization reaction easily occurs during storage of the ink and the storage stability is not sufficient. Furthermore, since conductive salts are contained and their solubility in ink may be poor, there is a concern of printing defects due to precipitation in a long-term storage state.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the various problems in the prior art and achieve the following objects. That is, the present invention is an ink composition which, in addition to conventional paper, can perform high-quality printing on a non-water-absorbent recording material such as plastic or metal, and is excellent in ink storage stability, water resistance, and light resistance. An object is to provide an object and an image recording method.

[0007]

Means for solving the problems Means for solving the above problems are as follows. That is, 1. An ink composition comprising a monomer having a polymerizable group, an oil-soluble dye, and a storage stabilizer, wherein the oil-soluble dye is dissolved in the ink. 2. 2. The ink composition as described in 1 above, wherein the polymerizable group is one selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group and a vinyl group. 3. 3. The ink composition according to 1 or 2 above, which further contains a photopolymerization initiator. 4. 4. The ink composition according to any one of 1 to 3 above, which is substantially free of water or conductive salts. 5. 5. The ink composition according to 1 to 4 above, which does not substantially contain a dispersion medium other than a monomer or a solvent. 6. 6. The ink composition according to any one of 1 to 5 above, wherein the oil-soluble dye is at least one selected from a cyan dye, a magenta dye, a yellow dye and a black dye. 7. 7. An image recording method, comprising: performing recording by using the ink composition according to any one of 1 to 6 above, and then curing by radiation.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION (Ink Composition) The ink composition of the present invention is a radiation-curable ink composition (radiation-curable ink composition), which comprises a monomer having a polymerizable group, an oil-soluble dye, and An ink composition containing a storage stabilizer, wherein the oil-soluble dye is dissolved in the ink. Further, it contains other components appropriately selected as necessary.

In the present invention, α-rays, γ-rays, X-rays, ultraviolet rays, visible rays, electron rays, etc. can be used as the radiation for promoting the polymerization of the monomers. Among these, it is preferable to use ultraviolet rays and visible rays from the viewpoint of cost and safety, and it is more preferable to use ultraviolet rays.

When ultraviolet rays, visible rays, etc. are used as the radiation, a photopolymerization initiator for initiating the polymerization is also used. The radiation curable ink according to another configuration of the present invention contains a photopolymerization initiator for initiating the polymerization of monomers.

-Monomer-The monomer used in the present invention (hereinafter referred to as "monomer of the present invention") is a polymerizable double bond which solidifies upon application of energy such as ultraviolet rays, heat or electron beams (hereinafter, the polymerizable double bond). A compound having a group). A monomer is a compound having two or more functional groups (hereinafter referred to as a polyfunctional monomer)
Is essential, and a monofunctional compound (hereinafter referred to as a monofunctional monomer) may be used in combination for adjusting viscosity, adjusting crosslink density, and controlling physical properties after curing (strength, adhesiveness, etc.).

Examples of the polymerizable group include an acryloyl group, a methacryloyl group, an allyl group, a vinyl group, and an internal double bond group (maleic acid etc.). Among them, the acryloyl group and the methacryloyl group can be cured with low energy. It is preferable, and acryloyl group is particularly preferable.

Examples of the polyfunctional monomers include vinyl group-containing aromatic compounds, acrylates which are esters of divalent or higher alcohols and acrylic acid or methacrylic acid, and 2
Acrylamide, which is an amide of a polyhydric amine or higher with acrylic acid or methacrylic acid, a polyester acrylate obtained by introducing acrylic acid or methacrylic acid into an ester or polycaprolactone obtained by bonding a polybasic acid and a dihydric alcohol, and an alkylene oxide. Polyether acrylate in which acrylic acid or methacrylic acid is introduced into ether obtained by binding of polyhydric alcohol, acrylic acid or methacrylic acid is introduced into epoxy resin, or divalent or higher alcohol is reacted with epoxy-containing monomer Obtained epoxy acrylate, urethane acrylate having urethane bond, amino resin acrylate, acrylic resin acrylate, alkyd resin acrylate, spirane resin acrylate, silicone resin acrylate , Etc. The reaction product of the polymerizable monomer and reaction products and waxes of the photopolymerizable monomer and the unsaturated polyester and the like, acrylate,
Polyester acrylates, polyether acrylates, epoxy acrylates, urethane acrylates, acrylic resin acrylates, silicone resin acrylates, reaction products of unsaturated polyesters and the photopolymerizable monomers are preferable, and acrylates, polyester acrylates, polyether acrylates, epoxy acrylates, urethanes. Acrylate is particularly preferred.

Examples of the polyfunctional monomer include divinylbenzene, 1,3-butanediol diacrylate,
1,6-hexanediol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, 1,6-acryloylaminohexane, hydroxypivalic acid ester neopentyl glycol diacrylate, dibasic acid and divalent Polyester acrylate having a (meth) acryloyl group at the molecular chain end of a polyester of alcohol having a molecular weight of 500 to 30,000,
Polyethylene glycol diacrylate, molecular weight 450-containing bisphenol (A or S, F) skeleton
Epoxy acrylate of 30,000, epoxy acrylate having a molecular weight of 600 to 30,000 containing a skeleton of a phenol novolac resin, a reaction product of a polyvalent isocyanate having a molecular weight of 350 to 30,000 and a (meth) acrylic acid monomer having a hydroxyl group, and a urethane bond in the molecule. And a urethane modified product having

As the monofunctional monomer, substituted or unsubstituted (meth) acrylate, substituted or unsubstituted styrene, substituted or unsubstituted acrylamide, vinyl group-containing monomer (vinyl ester, vinyl ether, N-vinyl amide, etc.) ), (Meth) acrylic acid, etc., and substituted or unsubstituted (meth) acrylate, substituted or unsubstituted acrylamide, vinyl esters, vinyl ethers are preferable, and substituted or unsubstituted (meth) acrylate, substituted or Unsubstituted acrylamide is particularly preferred.

Examples of the monofunctional monomer include hydroxyethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, 2-acryloyloxyethyl phosphate, allyl acrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylacrylamide, N, N-diethylaminopropylacrylamide,
N-butoxymethyl acrylamide, acryloyl morpholine, 2-hydroxyethyl vinyl ether, N-vinyl formamide, N-vinyl acetamide, 2-cyclohexylcarbamoyloxyethyl acrylate, acrylate containing polybutyl acrylate moiety in ester, polydimethylsiloxane moiety in ester And acrylates containing

The content of the monomer of the present invention in the ink composition is preferably in the range of 50 to 99.6% by mass, and 70 to 9% by mass.
The range of 99.0 mass% is more preferable, and 80-99.0.
The range of mass% is more preferable. The monomer may be any one as long as the effects of the present invention can be obtained, but it is more preferable to select from those having high safety. A highly safe monomer is one having a small PII (skin irritation) value, preferably one having a PII of 3.0 or less,
2.0 or less is more preferable, 1.0 or less is still more preferable, and 0.5 or less is particularly preferable.

-Photopolymerization Initiator and Sensitizer-The photopolymerization initiator is not particularly limited as long as radicals generated by light and other active species react with the polymerizable double bond in the monomer. Absent.

As the photopolymerization initiator, acetophenone derivative, benzophenone derivative, benzyl derivative, benzoin derivative, benzoin ether derivative, benzyldialkylketal derivative, thioxanthone derivative, acylphosphine oxide derivative, metal complex, p-dialkylaminobenzoic acid, azo Compounds, peroxide compounds and the like are generally known, acetophenone derivatives, benzyl derivatives, benzoin ether derivatives, benzyl dialkyl ketal derivatives, thioxanthone derivatives, acylphosphine oxide derivatives are preferable, acetophenone derivatives, benzoin ether derivatives, benzyl dialkyl ketal derivatives, Acylphosphine oxide derivatives are particularly preferred.

Examples of the photopolymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, benzophenone, p, p'-dichlorobenzophenone, p, p '. -Bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether,
Benzoin-n-propyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, 1-hydroxy-cyclohexyl phenyl ketone, tetramethyl thiuram monosulfide, thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone,
2,2-Dimethylpropioyl diphenylphosphine oxide, 2-methyl-2-ethylhexanoyl
Diphenylphosphine oxide, 2,6-dimethylbenzoyl diphenylphosphine oxide, 2,
6-dimethoxybenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2,3,6- Trimethylbenzoyl-diphenylphosphine oxide, bis (2,2
3,6-Trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethoxybenzoyl-
Diphenylphosphine oxide, 2,4,6-trichlorobenzoyl Diphenylphosphine oxide, 2,4,6-trimethylbenzoyl naphthylphosphonate, bis (η5-2,4-cyclopentadien-1-yl) -bis (2 , 6-Difluoro-3- (1H
-Pyrrol-1-yl) -finyl) titanium, p-
Dimethylaminobenzoic acid, p-diethylaminobenzoic acid, azobisisobutyronitrile, 1,1′-azobis (1-acetoxy-1-phenylethane), benzoin peroxide, di-tert-butyl peroxide and the like can be mentioned. .

Further, examples of the photopolymerization initiator include photopolymerization initiators described on pages 65 to 148 of "Ultraviolet curing system" by Kiyomi Kato (published by Sogo Gijutsu Center Co., Ltd .: 1989). Can be mentioned. These photopolymerization initiators can be used alone or in combination of two or more, and may be used in combination with a sensitizer.

The photopolymerization initiator is preferably one that does not cause thermal decomposition up to 80.degree. The use of an initiator that causes thermal decomposition at 80 ° C or lower is not preferable because it causes a problem in product storage.

The amount of these photopolymerization initiators used is not particularly limited, but is preferably 0.5 to 20% by mass,
15% by mass is more preferable, and 3 to 10% by mass is particularly preferable. If the amount is less than 0.5% by mass, the composition may not be cured or the curing time may be slow, and if it exceeds 20% by mass, precipitation or separation may occur after dissolution with time, and performance such as strength and scratch resistance of the ink after curing may be deteriorated. It is not preferable because it exists.

The sensitizer is not activated by irradiation with light by itself, but is more effective when used together with the photopolymerization initiator than when used alone as the photopolymerization initiator. Used. The reason why the curing rate is increased by adding amines is because first, hydrogen is supplied to the photopolymerization initiator by the hydrogen abstraction action, and secondly, the generated radicals are bonded to oxygen molecules in the atmosphere to cause reactivity. However, the amine has a function of trapping oxygen dissolved in the composition.

As the sensitizer, amine compounds (aliphatic amine, amine containing aromatic group, piperidine, reaction product of epoxy resin and amine, triethanolamine triacrylate, etc.), urea compound (allylthiourea, o-
Tolylthiourea), sulfur compounds (sodium diethyldithiophosphate, soluble salts of aromatic sulfinic acid, etc.), nitrile compounds (N, N-diethyl-p-
Aminobenzonitrile etc.), phosphorus compounds (tri-n-
Butylphosphine, sodium diethyldithiophosphide, etc.), nitrogen compounds (Michler's ketone, N-nitrisohydroxylamine derivatives, oxazolidine compounds,
Examples thereof include tetrahydro-1,3-oxazine compounds, formaldehyde or a condensate of acetaldehyde and diamine), chlorine compounds (carbon tetrachloride, hexachloroethane, etc.).

The amount of the sensitizer used is 0 to 10% by mass, preferably 0.1 to 10% by mass, and 0.2 to 5% by mass.
Is particularly preferable. The selection and combination of the photoinitiator and the sensitizer, and the compounding ratio can be appropriately selected depending on the ultraviolet curing monomer to be used and the apparatus used.

As a light source for irradiating ultraviolet rays or visible rays, a low pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp,
Carbon arc lamps, xenon lamps, chemical lamps, etc. can be used.

—Oil-Soluble Dye— Among the oil-soluble dyes that can be used in the present invention, any yellow dye can be used. For example, phenols, naphthols, anilines, pyrazolones, pyridones, aryl or heterylazo dyes having open-chain active methylene compounds as coupling components; for example, azomethine dyes having open-chain active methylene compounds as coupling components; Methine dyes such as benzylidene dyes and monomethine oxonol dyes; quinone dyes such as naphthoquinone dyes and anthraquinone dyes are available. Other dye types include quinophthalone dyes, nitro nitroso dyes, acridine dyes, An acridinone dye etc. can be mentioned.

Among the oil-soluble dyes usable in the present invention, any magenta dye can be used. For example, aryl or heterylazo dyes having phenols, naphthols, anilines as coupling components; for example, azomethine dyes having pyrazolones and pyrazolotriazoles as coupling components;
For example, methine dyes such as arylidene dyes, styryl dyes, merocyanine dyes, and oxonol dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, quinone dyes such as naphthoquinone, anthraquinone, and anthrapyridone, for example, Examples thereof include condensed polycyclic dyes such as dioxazine dyes.

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

Each of the above-mentioned dyes may exhibit yellow, magenta, and cyan colors only after a part of the chromophore is dissociated, and the counter cation in that case is an inorganic metal such as alkali metal or ammonium. It may be a cation, an organic cation such as a pyridinium or a quaternary ammonium salt, or a polymer cation having a partial structure thereof.

The content of the oil-soluble dye in the ink composition is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and particularly preferably 0.2 to 6% by mass.

—Storage Stabilizer— As the storage stabilizer, one that suppresses undesired polymerization during storage of the ink and that can be dissolved in the ink is used. Examples include quaternary ammonium salts, hydroxyamines, cyclic amides, nitriles, substituted ureas, heterocyclic compounds,
Examples thereof include organic acids, hydroquinone, hydroquinone monoethers, organic phosphines, copper compounds, and the like, and specific examples include benzyltrimethylammonium chloride, diethylhydroxylamine, benzothiazole, 4-amino-2,2,6,6-tetra. Methylpiperidine, citric acid, hydroquinone monomethyl ether, hydroquinone monobutyl ether, copper naphthenate and the like can be mentioned.

The amount of the storage stabilizer used is preferably adjusted appropriately based on the activity of the polymerization initiator used, the polymerizability of the monomer, and the type of the storage stabilizer.
05-1 mass% is preferable, 0.01-0.5 mass% is more preferable, and 0.01-0.2 mass% is still more preferable. If the added amount is too small, the storage stability will be poor, and if the added amount is too large, there will be a problem that curing after printing is difficult to occur.

-Conductive salt-The conductive salt is a solid compound which is dissolved in the ink to improve the conductivity. In the present invention, it is preferable not to use substantially because there is a great concern of precipitation during storage, but by increasing the solubility of the conductive salt or by using a highly soluble one in the liquid component of the ink. If the solubility is good, a suitable twill may be added. Examples of conductive salts include potassium thiocyanate, lithium nitrate, ammonium thiocyanate, dimethylamine hydrochloride and the like.

The ink composition of the present invention preferably contains substantially no water. If the ink contains water,
It is not preferable because the ink becomes muddy due to non-uniformity or dye deposition over time, and it becomes difficult to dry when a non-water-absorbing recording material is used.

-Other Components- The ink composition of the present invention may contain other components appropriately selected depending on the purpose, within a range that does not impair the effects thereof. Examples of the other components include known additives such as a solvent, a polymer, a surface tension adjusting agent, an ultraviolet absorber, an antioxidant, an anti-fading agent, and a pH adjusting agent.

The solvent can be used for the polarity of the ink, the viscosity, the surface tension, the solubility of the oil-soluble dye, the adjustment of the conductivity and the printing performance. Examples of the solvent include water, a low boiling point organic solvent, and a high boiling point organic solvent. The low boiling point organic solvent is an organic solvent having a boiling point of 100 ° C. or lower. The low boiling point organic solvent is preferably not used in consideration of environmental pollution, but when used, it is preferable to use one having high safety. A highly safe solvent is a solvent having a high controlled concentration (an index shown in the work environment evaluation standard), preferably 100 ppm or more.
00 ppm or more is more preferable. Examples thereof include alcohols, ketones, esters, ethers, hydrocarbons and the like, and specific examples include methanol, 2-butanol, acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran and the like.

The high boiling point organic solvent is an organic solvent having a boiling point higher than 100.degree. The high boiling point organic solvent has a boiling point of 15
It is preferably 0 ° C. or higher, more preferably 170 ° C. or higher. Examples thereof include polyhydric alcohols, esters of aliphatic carboxylic acids, phosphoric acid esters, hydrocarbons, and the like. Specifically, diethylene glycol, trimethylolpropane, dibutyl phthalate, and 2-ethylhexyl benzoate. , Alkylnaphthalene and the like.
These can be either liquid or solid at room temperature depending on the purpose.

The above solvents may be used alone or in combination of two or more, and the amount used is preferably 0 to 20% by mass,
-10 mass% is still more preferred, and it is especially preferred that it does not contain substantially. The term “substantially free from” means that the material used is contained as an impurity other than the main component, that is, not intentionally added.

The polymer can be used for adjusting the polarity and viscosity of the ink, improving the solubility of the oil-soluble dye, adjusting the adhesion of the cured ink to the recording material, and adjusting the light resistance.
The polymer may be dissolved in the ink or may be a fine dispersion, but from the viewpoint of the storage stability of the ink and the ejection performance, it is preferable that the polymer be dissolved.

When the polymer is dissolved in the ink, it is preferable that the polymer has high compatibility with the dye or the monomer.
The molecular weight is 50 because the viscosity of the ink does not easily increase.
000 or less is preferable, 20,000 or less is more preferable, and 10,000 is particularly preferable. Examples thereof include vinyl polymers, polyurethanes, polyesters, and the like. Specifically, polybutyl acrylate, poly (isobutyl methacrylate-hydroxyethyl acrylate) (copolymerization mass ratio 95: 5), poly (isopropyl acrylate-tetrahydrofurfuryl acrylate) ) (Copolymerization mass ratio 70:
30), poly (butyl methacrylate-N-methoxymethyl acrylamide) (copolymerization mass ratio 80:20), polybutyl acrylate-polydimethylsiloxane block copolymer (copolymerization mass ratio 90:10), and the like.

When the polymer is a fine dispersion, it is essential that the polymer is not substantially dissolved in the monomer, and it is preferable that the polymer does not easily swell or does not swell. The particle size of the dispersion in the ink is preferably 1 μm or less, 0.5 μm
The following is more preferable, and 0.1 μm or less is particularly preferable.
For example, vinyl polymer particles, polyurethane particles,
Examples thereof include polyester fine particles and urethane-vinyl composite particles. Specifically, poly (acrylonitrile-ethyl acrylate-ethylene glycol dimethacrylate) (copolymerization mass ratio 60: 37: 3), poly (styrene-butadiene) ( Copolymerization mass ratio 50:50) and the like.

The above polymers may be used alone or in combination of two or more. The amount used is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, and particularly preferably 0 to 20% by mass.

Regarding the surface tension adjusting agent, the ultraviolet absorber, the antioxidant, the anti-fading agent and the pH adjusting agent, JP-A-2001 is recommended.
For example, those described in Japanese Patent Publication No. 181549 may be used.

Although the physical properties of the ink depend on the printing apparatus, the viscosity of the ink composition is preferably 5 to 100 mPa · s,
10 to 80 mPa · s is more preferable. The surface tension of the ink composition is preferably 20 to 60 mN / m, 30 to 50
mN / m is more preferable.

(Image recording method) In the image recording method of the present invention, an image can be formed using the above-mentioned ink composition by a known recording method. In particular, when it is used in the inkjet recording method, the ink nozzle to be used. There are no particular restrictions on these, and they can be appropriately selected according to the purpose.

The ink composition of the present invention can be suitably printed on a known recording material. For example, plain paper, resin-coated paper, ink-jet dedicated paper, film, electrophotographic common paper, cloth, glass, metal, ceramics and the like can be mentioned. Regarding the recording material, Japanese Patent Application Laid-Open No. 2001-181549
It is described in the official gazette.

The ink composition of the present invention can be applied to any ink jet recording method, for example, a charge control method in which ink is ejected by using electrostatic attraction, or a drop-on-demand method in which vibration pressure of a piezo element is used. (Pressure pulse method), Acoustic ink jet method of converting electric signal into acoustic beam and irradiating ink to eject ink by using radiation pressure, Thermal ink jet that heats ink to form bubbles and utilizes generated pressure (Bubble Jet (registered trademark)) method, etc. are preferably used. The ink jet recording method is a method of ejecting a large number of low density inks called photo ink in a small volume, a method of improving image quality by using a plurality of inks having substantially the same hue but different densities, and a colorless transparent method. A method using ink is included.

[0050]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following, “parts” and “%” represent “parts by mass” and “mass%” unless otherwise specified.

Example 1 <Preparation of Ink 01> Oil-soluble dye (D-1) in a mixture of 49 parts of pentaerythritol tetraacrylate, 25 parts of hexamethylene-1,6-diacrylate and 15 parts of N-vinylformamide. 2.5 parts, fluorinated nonionic surfactant 1.2 parts, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide 4 parts, 1-hydroxy-cyclohexyl phenyl ketone 1 part, Triethanolamine 2.
An ink composition was prepared by adding 3 parts and 0.01 part of hydroquinone monomethyl ether (storage stabilizer), dissolving them, and filtering with a 0.45 μm filter.

<Preparation of Ink 02> 40 parts of pentaerythritol tetraacrylate, 24 parts of dipentaerythritol tetraacrylate, 9 parts of ethylene glycol diacrylate, 5 parts of diethylaminoethyl acrylate, 7 parts of N-vinylformamide and 5 parts of pentaerythritol. Oil-soluble dye (D-1) 2.
5 parts, fluorinated nonionic surfactant 1.2 parts, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide 3 parts, 1-hydroxy-cyclohexyl phenyl ketone 2 parts, thiocyanic acid 1.3 parts potassium, IRGANOX 101
An ink composition was prepared by adding 0.01 part of 0 (manufactured by Ciba Specialty Chemicals Co., Ltd .: storage stabilizer) and dissolving it, and filtering through a 0.45 μm filter.

<Preparation of Ink 03> A mixture of 40 parts of ditrimethylolpropane tetraacrylate, 34 parts of pentaerythritol tetraacrylate and 9 parts of tetrahydrofurfuryl acrylate was mixed with an oil-soluble dye (D-
1) 2.5 parts, polybutyl methacrylate (number average molecular weight 12000) 5 parts, fluorinated nonionic surfactant
1.2 parts, bis (2,6-dimethoxybenzoyl)-
Add 2,4,4-trimethylpentylphosphine oxide 3 parts, 1-hydroxy-cyclohexylphenyl ketone 2 parts, diethanolamine 2 parts, potassium thiocyanate 1.3 parts, hydroquinone monobutyl ether (storage stabilizer) 0.02 parts Dissolves, 0.45
An ink composition was prepared by filtering with a μm filter.

<Preparation of Inks 04 to 07> Ink 0
The ink compositions of Examples 4 to 7 were prepared in the same manner as in the preparation of Ink 01 except that the addition amount of hydroquinone monomethyl ether was changed in Preparation of 1.

<Preparation of Inks 08-07> Ink 0
In the preparation of No. 1, an ink composition of Ink 08 was prepared in the same manner as in the preparation of Ink 01 except that the oil-soluble dye (D-1) was replaced.

[0056]

[Chemical 1]

An image was recorded on a PET film using the prepared ink composition, and then exposed by a metal halide lamp at 500 mJ / cm ² . The following evaluations were performed on the ink and the obtained recording sample. The results are shown in Table 2.

<Storage Stability> After the ink was stored at 60 ° C. for 30 days, it was evaluated by the state of the ink and the filterability of 0.45 μm filter. A (good) when there is no change in the ink and good filterability of the filter, B (acceptable) when there is no change of the ink and bad filterability of the filter, and C (bad) when the ink is gelled or the viscosity increases. ).

<Curability> Observing the recorded image, A (good) indicates that there is no stickiness, B (acceptable) indicates that there is a little stickiness but does not stain the contacted object, and C indicates that the stickiness is remarkable. It was evaluated as (poor).

<Water resistance> The PET film on which the above image was formed was immersed in water for 1 minute and naturally dried at room temperature, and bleeding, peeling and color density were observed. A sample having no bleeding or peeling and no change in color density was evaluated as A (good), and a sample having any change was evaluated as B (poor).

<Light resistance> The PET film on which the image was formed was irradiated with xenon light (85000 lx) for 3 days by using a weather meter (Atlas CI65).
Reflection densitometer (X-Rite3)
10TR) and evaluated as the residual dye rate. A (good) when the dye residual rate is 80% or more, 80
Less than% was evaluated as B (poor).

[0062]

[Table 1]

As is clear from the results shown in Table 1, the ink 04 containing no storage stabilizer has no storage stability, and the ink 07 containing a large amount of storage stabilizer has excellent storage stability, but has a curability. bad. The ink composition of the present invention was excellent in storage stability and curability, and was excellent in water resistance and light resistance even when an image was recorded on PET which had no liquid absorption.

(Example 2) Evaluation was performed in the same manner as in Example 1 except that the image was recorded by changing the recording material.

[0065]

[Table 2]

As is clear from the results in Table 2, the ink composition of the present invention is excellent in storage stability, curability, water resistance and light resistance both on conventional paper and recording materials having no liquid absorption. It was

(Embodiment 3) A four-color ink set is prepared in the following manner to record a full-color image, and
When evaluated in the same manner as above, all of the storage stability, curability, water resistance, and light resistance were excellent.

<Yellow Ink> A mixture of 40 parts of ditrimethylolpropane tetraacrylate, 34 parts of pentaerythritol tetraacrylate and 9 parts of tetrahydrofurfuryl acrylate and an oil-soluble dye (D-4).
3.4 parts, polybutylmethacrylate (number average molecular weight 8
000) 5 parts, fluorinated nonionic surfactant 1.2
Part, bis (2,6-dimethoxybenzoyl) -2,4
4-Trimethylpentylphosphine oxide 3
Part, 1-hydroxy-cyclohexyl phenyl ketone
2 parts, diethanolamine 2 parts, potassium thiocyanate 1.3 parts, hydroquinone monobutyl ether
An ink composition was prepared by adding 0.01 parts of the above to dissolve and filtering with a 0.45 μm filter.

<Magenta Ink> Ink of Example 1 08
Was used.

<Cyan Ink> The above yellow ink except that 4.6 parts of the oil-soluble dye (D-3) was used in place of 3.4 parts of the oil-soluble dye (D-1) in the preparation of the yellow ink. A cyan ink was prepared in the same manner as the ink preparation.

<Black Ink> In the preparation of the yellow ink, 1.2 parts of oil-soluble dye (D-2) and oil-soluble dye (D-) were used instead of 3.4 parts of oil-soluble dye (D-1).
5) A black ink was prepared in the same manner as in the preparation of the yellow ink, except that 2.3 parts and 1.7 parts of the oil-soluble dye (D-4) were used.

[0072]

[Chemical 2]

[0073]

According to the present invention, not only a recording material having liquid absorbability but also a recording material having no liquid absorbability can be used to form a good image, and storage stability, curability, and An ink composition having excellent water resistance and light resistance and an image recording method can be provided.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2C056 EA13 FC02 HA44                 2H086 BA05 BA56 BA59                 4J039 AD10 AD21 AE03 AE04 AE05                       AE06 AE07 AE11 AF03 BE07                       BE24 BE27 CA04 EA04 EA05                       EA06 EA15 EA16 EA17 EA19                       EA35 EA38 EA44 FA01 FA02

Claims (7)

[Claims] 1. An ink composition containing a monomer having a polymerizable group, an oil-soluble dye, and a storage stabilizer, wherein the oil-soluble dye is dissolved in the ink. object. 2. The ink composition according to claim 1, wherein the polymerizable group is one selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group and a vinyl group. 3. The ink composition according to claim 1, further comprising a photopolymerization initiator. 4. The ink composition according to claim 1, which is substantially free of water or conductive salts. 5. The ink composition according to claim 1, which does not substantially contain a dispersion medium other than the monomer or a solvent. 6. The ink composition according to claim 1, wherein the oil-soluble dye is at least one selected from a cyan dye, a magenta dye, a yellow dye and a black dye. 7. An image recording method, comprising: performing recording by using the ink composition according to claim 1 and then curing by radiation.