JP2015093950A - Yellow ink composition, inkjet recording method and colored body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition of a yellow color having a color phase similar to Japan color and excellent color developability, an inkjet recording method using the same, and a colored body obtained by using the same.SOLUTION: A yellow ink composition is used for inkjet recording comprising at least two kinds of first and second colorants, water-soluble organic solvent and water, with the first colorant being C.I.Pigment Yellow 213, and the second colorant being C.I.Pigment Yellow 180.

Description

  The present invention relates to a yellow ink composition, an ink jet recording method using the ink composition, and a colored body.

  As colorants used in ink jet inks, two types of water-soluble dyes and water-insoluble pigments are generally used. Among these, recorded images using dyes are excellent in image quality such as sharpness, while recorded images using pigments are excellent in various fastnesses such as light, ozone and water, and therefore contain pigments as colorants. The use of inkjet ink (inkjet pigment ink) is expanding.

With the use of pigment ink, the recorded image is required to improve image quality more than ever, and one of them is to improve hue and color development.
Usually, as a hue evaluation index, Japan color, which is mainly used in offset printing, is used as a standard. However, as a commonly used yellow pigment ink, there are no known pigment inks that are close to Japan color and have good color developability.
In general, it is known that cyan pigments and magenta pigments are excellent in both hue and light resistance. However, C. has been widely used conventionally. I. Pigment Yellow 74 is excellent in color developability, but is different from the hue of Japan color.
For these reasons, there is a strong demand for the development of a yellow ink composition for ink-jet recording having a hue close to Japan color and good color developability.

  Under the circumstances as described above, many proposals have conventionally been made regarding yellow pigments that give recorded images with excellent hue and color developability, and inks containing them. As such a thing, patent document 1 thru | or 6 etc. are mentioned, for example.

JP 2008-266568 A JP 2008-291103 A JP 2009-173853 A JP 2010-248287 A JP 2012-188866 A JP 2013-67780 A

  An object of the present invention is to provide a yellow ink composition having a hue close to Japan color and good color development, an ink jet recording method using the same, and a colored product obtained therefrom.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that inks used for ink jet recording containing at least two specific first and second colorants, a water-soluble organic solvent, and water, respectively. The present inventors have found that the above problems can be solved by the composition, and have completed the present invention.

That is, the present invention relates to the following [1] to [13].
[1]
An ink composition used for inkjet recording containing at least the first and second colorants, a water-soluble organic solvent and water, wherein the first colorant is C.I. I. Pigment Yellow 213, and the second colorant is C.I. I. An ink composition which is CI Pigment Yellow 180.
[2]
The ink composition according to the above [1], wherein the total content of the colorant is 0.5% by mass or more and 7% by mass or less with respect to the total mass of the ink composition.
[3]
The ink composition according to the above [1] or [2], wherein the content of the first colorant in the total mass of the colorant contained in the ink composition is 10% by mass or more and 90% by mass or less.
[4]
The ink composition according to the above [1] or [2], wherein the content of the first colorant in the total mass of the colorant contained in the ink composition is 20% by mass or more and 80% by mass or less.
[5]
An ink jet recording method in which recording is performed by ejecting droplets of the ink composition according to any one of the above [1] to [4] by an ink jet printer in accordance with a recording signal and attaching the droplets to a recording material.
[6]
The inkjet recording method according to [5], wherein the recording material is an information transmission sheet.
[7]
The inkjet recording method according to [6], wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance.
[8]
The inkjet recording method according to [6], wherein the information transmission sheet is cast-coated paper.
[9]
The inkjet recording method according to [6], wherein the information transmission sheet is coated paper or art paper.
[10]
The inkjet recording method according to [6], wherein the information transmission sheet is a sheet subjected to a surface modification treatment selected from corona discharge treatment, plasma treatment, and frame treatment.
[11]
A colored body colored with the ink composition according to any one of [1] to [4].
[12]
A colored body obtained by the inkjet recording method according to any one of [5] to [10].
[13]
An inkjet printer loaded with a container containing the ink composition according to any one of [1] to [4].

  By using the ink composition of the present invention, a light-resistant, yellow-colored ink composition having a hue similar to Japan color and good color developability, an ink jet recording method using the same, and a colored product obtained therefrom Could be provided.

Hereinafter, the present invention will be described in detail.
In this specification, “CI” is an abbreviation for color index. In addition, in the present specification, “%” and “parts” are described on a mass basis, including examples, unless otherwise specified.

  The ink composition is a yellow ink composition used for ink jet recording, which contains at least two kinds of colorants, and C.I. I. Pigment Yellow 213, C.I. I. Contains CI Pigment Yellow 180.

The total colorant content in the total mass of the ink composition is usually 0.5% to 7%, preferably 1% to 7%, more preferably 2% to 7%.
If it is less than 0.5%, the color developability of the recorded image is insufficient, and if it exceeds 7%, there may be a problem in ejection properties.

  The content of the first colorant in the total mass of the colorant contained in the ink composition is usually 10% or more and 90% or less, preferably 20% or more and 80% or less, more preferably 30%. It is 75% or less, more preferably 40% or more and 60% or less. Beyond this range, it becomes difficult to improve color developability and hue at the same time.

  Although the ink composition can be used alone, it is used as a yellow ink composition for the purpose of obtaining a full-color recorded image, for example, as an ink set for inkjet recording comprising a cyan ink composition, a magenta ink composition, and a black ink composition. You can also. At this time, the colorant contained in each of the cyan, magenta, and black ink compositions is not particularly limited, and a known pigment can be arbitrarily used. In addition to the four-color ink set, for the purpose of obtaining a recorded image with a higher-definition hue, for example, violet, orange-brown, green, and other ink compositions may be added as necessary. It can also be an ink set.

The ink composition may further contain a dispersing agent in order to stabilize the dispersion state of the contained pigment.
Also, instead of the combination of pigment and dispersant, a so-called surface-treated pigment (self-dispersed pigment) in which a dispersibility-imparting group is directly introduced on the surface of the pigment; the pigment is uniformly coated with the above-described dispersant So-called microcapsule pigments; etc. can also be used as the colorant.

Examples of the dispersant include styrene and derivatives thereof; vinyl naphthalene and derivatives thereof; aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids, etc .; acrylic acid and derivatives thereof; maleic acid and derivatives thereof; itaconic acid and derivatives thereof Fumaric acid and derivatives thereof; vinyl acetate, vinyl alcohol, vinyl pyrrolidone, acrylamide, and derivatives thereof; at least two monomers selected from the group consisting of monomers; preferably at least one of which is And a copolymer comprising a hydrophilic monomer), for example, a block copolymer, a random copolymer and a graft copolymer, and / or a salt thereof. The various copolymers and / or salts thereof can be used in combination.
As a weight average molecular weight of a dispersing agent, it is about 1000-30000, Preferably it is 1250-25000, More preferably, it is about 1500-20000. Moreover, as an acid value, it is about 80-300, Preferably it is 90-275, More preferably, it is about 100-250.
Specific examples of the commercially available dispersant include Jonkrill 61J, 68, 450, 55, 555, 586, 680, 682, 683; and B-36; manufactured by BASF. .

The amount of the dispersant used is generally represented by a numerical value called a limiting ratio. This division ratio can be obtained by the following equation.
Ratio = dispersant / colorant.

  In the present invention, the limiting ratio is preferably 0.1 to 1.0, more preferably 0.1 to 0.8, and particularly preferably 0.2 to 0.6. When the limiting ratio is not within this range, the dispersion stability may be deteriorated; the image of the printed matter may be deteriorated;

Examples of the method for dispersing the pigment include a method using a sand mill (bead mill), a roll mill, a ball mill, a paint shaker, an ultrasonic disperser, a microfluidizer, and the like. Among these, a sand mill is preferable. In addition, the preparation of the pigment dispersion using a sand mill can be performed under conditions where the dispersion efficiency is increased by using beads having a small diameter (0.01 mm to 1 mm diameter) and increasing the filling rate of the beads. preferable.
By dispersing under such conditions, the particle size of the colorant can be reduced, and a dispersion having good dispersibility can be obtained. In addition, it is also preferable to remove components having a large particle size from the dispersion by filtration and / or centrifugation after the dispersion is prepared.
In addition, if the foaming of the liquid is severe during preparation of the dispersion, a very small amount of an antifoaming agent such as silicone or acetylene glycol may be added for the purpose of suppressing the foaming.

Examples of the water-soluble organic solvent contained in the ink composition include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol or tert-butanol, 1,2-hexanediol, and 1,6-hexanediol. C1-C6 alkanols such as trimethylolpropane; carboxylic acid amides such as N, N-dimethylformamide or N, N-dimethylacetamide; 2-pyrrolidone, N-methyl-2-pyrrolidone or N-methylpyrrolidin-2-one Lactams such as: cyclic ureas such as 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido-2-one; acetone, 2-methyl-2-hydroxypentan-4-one , Ketones such as ethylene carbonate or keto alcohols; Cyclic ethers such as hydrofuran and dioxane; ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol , Triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, mono-, oligo- or polyalkylene glycols or thioglycols having C2-C6 alkylene units such as thiodiglycol or dithiodiglycol; glycerin, diglycerin , Polyols (triol) such as hexane-1,2,6-triol; ethylene glycol monomethyl ether, ethylene glycol monoethyl Ether, ethylene glycol monoallyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether C1-C4 alkyl ethers of polyhydric alcohols such as propylene glycol monopropyl ether, prolene glycol monobutyl ether, dipropylene glycol monomethyl ether; γ-butyrolactone or dimethyl sulfoxide, etc .; polyethylene glycol having a molecular weight of 400, 800, 1540 or higher Kind. These organic solvents can be used alone or in combination of two or more.
The total content of the water-soluble organic solvent in the total mass of the ink composition is usually 1 to 60%, preferably 1 to 45%, more preferably 5 to 40%, and the balance is water.

The ink composition can contain an ink preparation agent as necessary.
Examples of the ink preparation agent include antiseptic / antifungal agents, pH adjusting agents, chelating reagents, rust preventive agents, water-soluble ultraviolet absorbers, water-soluble polymer compounds, antioxidants, water-dispersible resins, and surfactants. Is mentioned.
The total content of the ink preparation agent in the total mass of the ink composition is usually 0 to 30%, preferably 0 to 15%.

  Specific examples of the antifungal agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one, and salts thereof. .

  Examples of preservatives include, for example, organic sulfur, organic nitrogen sulfur, organic halogen, haloaryl sulfone, iodopropargyl, haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzothiazole , Isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, benzyl Examples thereof include bromoacetate-based or inorganic salt-based compounds. Specific examples of organic halogen compounds include sodium pentachlorophenol, specific examples of pyridine oxide compounds include, for example, sodium 2-pyridinethiol-1-oxide, and isothiazoline compounds include, for example, 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4 -Isothiazoline-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride and the like. Specific examples of other antiseptic / antifungal agents include anhydrous sodium acetate, sodium sorbate or sodium benzoate, trade names Proxel GXL (S) and Proxel XL-2 (S) manufactured by Arch Chemical Co., Ltd.

  As the pH adjuster, any substance can be used as long as it can control the pH of the ink within a range of, for example, 5 to 11 without adversely affecting the prepared ink. Specific examples thereof include, for example, alkanolamines such as diethanolamine, triethanolamine and N-methyldiethanolamine (preferably mono-, di- or tri-C1-C4 alkylamines optionally having a hydroxy group as a substituent); water Periodic table Group 1 element hydroxides such as lithium oxide, sodium hydroxide, potassium hydroxide; ammonium hydroxide (ammonia water); or lithium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, etc. Group element carbonates; salts of group 1 elements of organic acids such as sodium silicate and potassium acetate; inorganic bases such as disodium phosphate; and the like.

  Specific examples of the chelating reagent include, for example, disodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate or sodium uracil diacetate.

  Specific examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate or dicyclohexylammonium nitrite.

  Examples of water-soluble UV absorbers include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

  Specific examples of the water-soluble polymer compound include polyethylene glycol, polyvinyl alcohol, cellulose derivatives, polyamine or polyimine.

  As examples of the antioxidant, for example, various organic and metal complex anti-fading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines or heterocyclic rings. .

The water-dispersible resin has a function of fixing the colorant in the ink composition to the recording material by forming a film at room temperature. The resin used for the water dispersible resin is not particularly limited, and examples thereof include urethane resins, polyester resins, acrylic resins, vinyl acetate resins, vinyl chloride resins, acrylic styrene resins, acrylic silicone resins, and the like. Can be mentioned.
The water-dispersible resin is used, for example, in the state of a resin emulsion dispersed in water as a continuous phase.
Specific examples of commercially available resin emulsions include, for example, Superflex 126, 150, 170, 210, 420, 470, 820, 830, 890 (urethane resin emulsion, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.); Hydran HW- 350, HW-178, HW-163, HW-171, AP-20, AP-30, WLS-201, WLS-210 (urethane resin emulsion manufactured by DIC); 0569, 0850Z, 2108 (styrene-butadiene resin) Emulsions manufactured by JSR); AE980, AE981A, AE982, AE986B, AE104 (acrylic resin emulsion manufactured by Etec);
When the water dispersible resin is used, the content of the water dispersible resin in the total mass of the ink composition is usually 0.5 to 20%, preferably 0.5 to 10% in terms of solid content. When the content of the water-dispersible resin is less than this range, it is difficult to obtain sufficient fixability to the recording material, and when it is large, normal ejection of ink droplets in ink jet recording is hindered. Sometimes.

  Examples of the surfactant include anionic, cationic, nonionic, amphoteric, silicone-based, and fluorine-based surfactants.

  Examples of anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids or salts thereof, and N-acyl methyl taurine salts. , Alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl Examples include sulfonate, diethylsulfosuccinate, diethylhexylsulfosuccinate, and dioctylsulfosuccinate. Specific examples of such commercially available products include, for example, Hytenol LA-10, LA-12, LA-16, Neo-Hytenol ECL-30S, ECL-45 and the like manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

  Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, imidazoline derivatives, etc. Is mentioned.

Nonionic surfactants include ethers such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether; Ester systems such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl Acetylene glycol (alcohol) type such as lu-1-hexyn-3-ol; all of which are Surfinol 104, 104PG50, 105PG50, 82, 420, 440, 465, 485 manufactured by Nissin Chemical Co., Ltd .; Orphine STG; Polyglycol ether System (for example, TergItol15-S-7 manufactured by SIGMA-ALDRICH); and the like.
Of these, Surfynol is preferred.

  Examples of the silicone surfactant include polyether-modified siloxane and polyether-modified polydimethylsiloxane. Specific examples of commercially available products include BYK-347 (polyether-modified siloxane); BYK-345, BYK-348 (polyether-modified polydimethylsiloxane);

  Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group as a side chain. And polyoxyalkylene ether polymer compounds. Specific examples of commercially available products include, for example, Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, Capstone FS-30, FS-31 (manufactured by DuPont); PF-151N , PF-154N (manufactured by Omninova);

Of the above, anionic, nonionic, silicone-based, and fluorine-based surfactants are preferred. These surfactants can be used alone or in combination of two or more.
When the ink composition contains a surfactant, the total content of the surfactant in the total mass of the ink composition is usually 0.1% to 5%, preferably 0.3% to 3%. .
If it is 0.1% or less, the effect as a surfactant cannot be obtained, and if it is 5% or more, a problem may occur in the dispersion stability of the pigment.

The ink composition preferably has a low content of inorganic impurities such as metal cation chloride (for example, sodium chloride) and sulfate (for example, sodium sulfate). As a standard of the content of inorganic impurities, it is about 1% or less with respect to the total mass of the colorant, and the lower limit may be less than the detection limit of the analytical instrument, that is, 0%.
Inorganic impurities are often mixed in the original colorant. For this reason, for example, a method using a reverse osmosis membrane; or a method in which a coloring agent is suspended in a mixed solvent of C1-C4 alcohol such as methanol and water and stirred, and then a precipitate is filtered and dried; Alternatively, it is also preferable to remove inorganic impurities by a method of exchanging and adsorbing inorganic impurities with an ion exchange resin;

The pH of the ink composition is preferably pH 5 to 11 and more preferably pH 7 to 10 for the purpose of improving storage stability.
Further, the surface tension of the ink composition is preferably 10 to 50 mN / m, and more preferably 20 to 40 mN / m.
Furthermore, the viscosity of the ink composition is preferably 30 mPa · s or less, and more preferably 20 mPa · s or less. The pH and surface tension of the ink composition of the present invention can be appropriately adjusted with a pH adjusting agent, a surfactant or the like.

  The ink composition can be used as ink in various fields. Examples thereof include water-based ink for writing, water-based printing ink, information recording ink, textile printing and the like. The recording method is particularly preferably used for inkjet recording.

  The ink jet recording method is a method of recording by ejecting droplets of the ink composition by an ink jet printer in accordance with a recording signal and adhering them to a recording material. There is no restriction | limiting in particular about an inkjet printer, its ink nozzle, etc., According to the objective, it can select suitably.

There are no particular restrictions on the ejection method of the ink jet printer. For example, a charge control method that ejects ink using electrostatic attraction; a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezoelectric element; an electrical signal An acoustic ink jet system that converts ink into an acoustic beam and irradiates the ink using the radiation pressure; thermal ink jet that heats the ink to form bubbles and uses the generated pressure, that is, bubble jet (registered trademark) ) Method;
In the ink jet recording method, a method called a photo ink, which ejects a large number of inks with a small pigment concentration (colorant content) in a small volume; pigments in the ink having substantially the same hue. A method of improving image quality using a plurality of inks having different densities; a method of using colorless and transparent inks; and the like are also included.

The colored body means a substance colored by the ink composition, and preferably includes a recording material colored by the ink composition or the inkjet recording method.
The recording material is not particularly limited, and examples thereof include information transmission sheets such as paper and film, fibers and cloths (cellulose, nylon, wool, etc.), leather, and color filter base materials. Among these, an information transmission sheet is preferable.
Information transmission sheets can be broadly classified into those having an ink receiving layer and those having no ink receiving layer.
As what has an ink receiving layer, what used paper, a synthetic paper, a film, etc. as a base material and provided the ink receiving layer in these base materials is mentioned, for example. The ink receiving layer may be formed by, for example, impregnating or coating the base material with a cationic polymer; or inorganic fine particles capable of receiving a colorant in ink such as porous silica, alumina sol, or special ceramics. A method of coating the surface of the substrate together with a hydrophilic polymer such as
An information transmission sheet having an ink receiving layer is generally called ink jet exclusive paper, ink jet exclusive film, glossy paper or the like. Typical examples of commercially available products are Canon Inc. trade names: professional photo paper, super photo paper, glossy gold and matte photo paper; Seiko Epson Corporation trade names: photographic paper Krispia (high gloss) Photographic paper (gloss), photo matte paper; product name manufactured by Nippon Hewlett-Packard Co., Ltd .: advanced photo paper (gloss); product name manufactured by FUJIFILM Corporation: painting photo finishing pro;

  Examples of the information transmission sheet having no ink receiving layer include coated paper used for gravure printing and offset printing, various papers such as art paper, and cast coated paper used for label printing.

  As the information transmission sheet, plain paper that has not been subjected to surface treatment can be suitably used. Generally, plain paper is not coated on both sides, and water-based ink bleeding (feathering) tends to occur along the fiber direction of the pulp exposed on the surface. Therefore, in many cases, a sizing agent of about 0.1% with respect to the mass of the pulp is added in order to suppress bleeding of the aqueous ink. The above plain paper has the effect of suppressing the bleeding of aqueous ink by adding a sizing agent and improving the image quality, but has the property of lowering the penetration speed of aqueous ink, and is basically an ink jet recording that uses the osmotic drying method. Therefore, it is a recording material in which early drying is difficult to obtain. However, by using the ink composition, a good image can be obtained even if these recording materials are used.

  When an information transmission sheet having no ink receiving layer is used as a recording material, it is also preferable to subject the recording material to a surface modification treatment for the purpose of improving the fixing property of the colorant.

  As the surface modification treatment, it is preferable to perform at least one treatment selected from corona discharge treatment, plasma treatment and flame treatment. For these processes, any known method may be used. In addition, it is generally known that the effects of these treatments decrease with time. For this reason, when surface modification processing is performed on the information transmission sheet, it is preferable to continuously perform ink jet recording without taking time.

  Examples of the corona discharge treatment include a method in which a corona discharge is generated by applying a high voltage of several thousand volts between a grounded metal roll and a wire-like electrode placed at intervals of several mm. By disposing and processing the information transmission sheet between the electrode and the roll during the corona discharge, the surface of the sheet is hydrophilized.

  In the plasma treatment, an information transmission sheet is placed in a container containing argon, neon, helium, nitrogen, nitrogen dioxide, oxygen, air, or the like, and exposed to plasma generated by glow discharge, whereby oxygen, nitrogen is applied to the surface of the sheet. The method of introduce | transducing the functional group containing etc. is mentioned. When an inert gas such as argon or neon is present at a low pressure, it is considered that radicals are generated on the surface of the sheet by the generated plasma. Then, it is considered that the radical is combined with oxygen by being exposed to air, and a carboxylic acid group, a carbonyl group, an amino group, or the like is introduced to the surface of the information transmission sheet.

  The flame treatment is also referred to as flame treatment, and examples thereof include a method of improving hydrophilicity by spraying a gas oxidation flame or the like sprayed from a burner or the like on the surface of the information transmission sheet to oxidize the surface of the sheet.

  The surface modification treatment can be performed by appropriately adjusting the number of treatments, treatment time, applied voltage, and the like so as to obtain a desired effect.

  When recording on a recording material by the ink jet recording method, a container containing the ink composition is loaded at a predetermined position of the ink jet printer, and recording is performed on the recording material by the above recording method.

According to the present invention, it is possible to provide an inkjet yellow ink having improved color developability and hue. Further, an ink set, an ink jet recording method and a colored body using the ink composition of the present invention as a yellow ink composition are excellent in color balance with other color ink compositions other than the yellow ink composition, and the image is sharp. Can be improved.
In addition, by using the ink composition of the present invention, a recorded image with high saturation can be obtained, and a recorded material having a visual sense of density, a clear and wide color gamut can be obtained.
Furthermore, it is possible to obtain images excellent in various fastness properties such as scratch resistance, water resistance, light resistance, heat resistance, and oxidation gas (eg, ozone gas) resistance.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited at all by the following example. Unless otherwise specified, when filtration and separation were performed, suction filtration was performed using glass filter paper GC-50 and glass filter paper GA-100 alone or in combination as filter paper.
Moreover, when measuring solid content in aqueous solution, solid content was calculated | required by dry weight method using MS-70 by A & D Corporation.
When color measurement was necessary, color measurement was performed using a trade name SpectroEye manufactured by X-Rite as a colorimeter.

[Preparation Example 1]: Preparation of dispersion 1.
A block copolymer described in Synthesis Example 3 of International Publication No. 2013/115071 was prepared, and 8 parts of the resulting polymer dispersant (block copolymer) was added to 20 parts of 2-butanone to form a solution. . A solution prepared by dissolving 0.6 part of sodium hydroxide in 50.7 parts of ion exchange water was added to this solution, and the mixture was stirred for 1 hour to prepare an emulsion. At this time, there was no solid precipitation. To this emulsion, C.I. I. Pigment Yellow 213 (Clariant, Hostaperm Yellow H5G), 12 parts, and C.I. I. 8 parts of Pigment Yellow 180 (manufactured by Clariant, Toner YellowHG) was added, and dispersion treatment was performed for 15 hours under a condition of 1500 rpm using a sand grinder. 100 parts of ion-exchanged water was added dropwise to the obtained liquid, and filtered to remove the dispersing beads to obtain a mother liquid. From the obtained mother liquor, 2-butanone and water were distilled off under reduced pressure using an evaporator to obtain a yellow dispersion having a solid content of 12.0%. The resulting dispersion is referred to as “Dispersion 1”. The pH of the dispersion 1 was 9.2, the average particle size was 113 nm, and the viscosity was 16.1 mPa · s.

[Preparation Example 2]: Preparation of dispersion 2.
C. used in Preparation Example 1 I. Pigment Yellow 213 and C.I. I. A yellow dispersion was obtained in the same manner as in Preparation Example 1, except that the amount of Pigment Yellow 180 was changed to 10 parts each. The resulting dispersion is referred to as “Dispersion 2”. The pH of the dispersion 2 was 9.3, the average particle size was 127 nm, and the viscosity was 11.4 mPa · s.

[Preparation Example 3] Preparation of comparative dispersion 3
C. used in Preparation Example 1 I. Pigment Yellow 180, C.I. I. A yellow dispersion liquid was obtained in the same manner as in Preparation Example 1 except that 20 parts of Pigment Yellow 213 alone was used. The pH of dispersion 3 in which the obtained dispersion was “dispersion 3” was 8.9, the average particle size was 115 nm, and the viscosity was 8.9 mPa · s.

[Preparation Example 4]: Preparation of dispersion 4 for comparison.
C. used in Preparation Example 1 I. Without using Pigment Yellow 213, C.I. I. A yellow dispersion was obtained in the same manner as in Preparation Example 1 except that 20 parts of Pigment Yellow 180 alone was used. The resulting dispersion is referred to as “Dispersion 4”. The pH of dispersion 4 was 9.3, the average particle size was 139 nm, and the viscosity was 13.8 mPa · s.

[Preparation of ink composition]
Each of the dispersions obtained in the above Preparation Examples 1 to 4 and each of the components shown in Table 1 below were mixed, and then the foreign substances were filtered off with a 3 μm membrane filter. Ink compositions were prepared. All ink compositions were adjusted so that the colorant content in the total mass of the ink composition was 5%.

Abbreviations and the like in the following Table 1 have the following meanings.
PG: Propylene glycol IPG: Isopropyl glycol.
Sf-465: Surfynol 465.
GXL (S): Proxel GXL (S).
Water: Ion exchange water.

[A. Color difference evaluation]
Using the ink compositions of Examples and Comparative Examples prepared as described above, solid ink jet recording is performed on the following two types of recording materials using a commercially available ink jet printer (OPX-105 manufactured by Epson Corporation). As a result, a yellow colored product was obtained. Using the obtained colored body as a test piece, measuring the hue with a colorimeter, obtaining the color difference (ΔE) with the hue defined in the Japan color for sheet-fed printing, which is a standard index of offset printing color, Evaluation was performed according to the following three-level evaluation criteria. The results are shown in Table 2 below.
[Evaluation criteria]
A: ΔE is less than 3.
B: ΔE is 3 or more and less than 5.
C: ΔE is 5 or more.
[Recording material]
Cast paper: N mirror manufactured by Oji Paper.
Gloss paper: Foam gloss made by Oji Paper.

[B. Evaluation of color development]
In the same manner as described above, inkjet recording was performed on two types of recording materials to obtain yellow colored bodies. The obtained colored product was used as a test piece, and the color developability (printing density) was measured with a colorimeter, and evaluated according to the following two evaluation criteria. The results are shown in Table 2 below.
[Evaluation criteria]
A: 1.5 or more.
B: 1.1 or more and less than 1.5.

  Each example is a color that is close to the standard color Japan color and has a very good hue. It was also confirmed that the color developability was also good.

  The ink-jet yellow ink composition of the present invention is extremely useful as an ink for ink-jet recording because of good color developability and hue.

Claims (13)

  An ink composition used for inkjet recording containing at least the first and second colorants, a water-soluble organic solvent and water, wherein the first colorant is C.I. I. Pigment Yellow 213, and the second colorant is C.I. I. An ink composition which is CI Pigment Yellow 180.   The ink composition according to claim 1, wherein the total content of the colorant is 0.5% by mass or more and 7% by mass or less with respect to the total mass of the ink composition.   3. The ink composition according to claim 1, wherein the content of the first colorant in the total mass of the colorant contained in the ink composition is 10% by mass or more and 90% by mass or less.   3. The ink composition according to claim 1, wherein the content of the first colorant in the total mass of the colorant contained in the ink composition is 20% by mass or more and 80% by mass or less.   An ink jet recording method for performing recording by ejecting droplets of the ink composition according to any one of claims 1 to 4 by an ink jet printer in accordance with a recording signal and adhering the ink composition to a recording material.   The ink jet recording method according to claim 5, wherein the recording material is an information transmission sheet.   The ink jet recording method according to claim 6, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance.   The inkjet recording method according to claim 6, wherein the information transmission sheet is cast-coated paper.   The inkjet recording method according to claim 6, wherein the information transmission sheet is coated paper or art paper.   The inkjet recording method according to claim 6, wherein the information transmission sheet is a sheet subjected to a surface modification treatment selected from a corona discharge treatment, a plasma treatment, and a frame treatment.   A colored body colored with the ink composition according to claim 1.   A colored body obtained by the ink jet recording method according to any one of claims 5 to 10.   An inkjet printer loaded with a container containing the ink composition according to claim 1.