JP2021138829A - Yellow ink, ink set, ink container, recording apparatus, and recording method - Google Patents

Abstract

To improve image glossiness in an image formed using a yellow ink containing a yellow coloring material excellent in light stability such as pigment yellow 138, etc., the image glossiness having been insufficient in pigment yellow 138 excellent in light stability and a yellow ink containing water, which are conventionally disclosed.SOLUTION: A yellow ink contains water, a resin and a coloring material. The resin is an urethane resin particle. The coloring material has at least one of pigment yellow 138 and pigment yellow 150.SELECTED DRAWING: None

Description

The present invention relates to a yellow ink, an ink set, an ink container, a recording device, and a recording method.

Inkjet recording devices have advantages such as low noise, low running cost, and easy color printing, and are widely used in general households as digital signal output devices. In recent years, inkjet technology has been used not only for home use but also for commercial use and industrial use. Then, in commercial use and industrial use, printing may be performed on a recording medium installed outdoors, and in such use, light resistance in a printed image is required.

Patent Document 1 discloses Pigment Yellow 138, which has excellent light resistance, and a yellow ink containing water in Examples.

However, there is a problem that the image glossiness is insufficient in an image formed by using a yellow ink containing a yellow coloring material having excellent light resistance such as Pigment Yellow 138.

The invention according to claim 1 is a yellow ink containing water, a resin, and a coloring material, wherein the resin is urethane resin particles, and the coloring material contains at least one of pigment yellow 138 and pigment yellow 150. It is a yellow ink that has.

The yellow ink of the present invention has an excellent effect of obtaining an image having high light resistance and image glossiness.

FIG. 1 is a perspective explanatory view showing an example of a recording device. FIG. 2 is a perspective explanatory view showing an example of the main tank.

Hereinafter, an example of the embodiment of the present invention will be described.

<< Yellow Ink >>
The yellow ink of the present embodiment contains water, a resin, and a coloring material, and may contain an organic solvent, a surfactant, and other additives, if necessary. Note that yellow represents a color that is generally recognized as yellow in the conventional wisdom. For example, the brightness (L ^{* ) in the L *} a ^* b ^* color system on glossy paper is 70 or more and 100 or less, and the saturation. It is preferable that (C ^* ) is 55 or more and 90 or less, and the hue angle (h) is 70 ° or more and 140 ° or less. Further, the yellow ink represents an ink that can express the yellow color by itself.

<Color material>
-Pigment Yellow 138 and Pigment Yellow 150-
The color material contained in the yellow ink is at least one selected from pigment yellow 138 and pigment yellow 150, and if necessary, a yellow color material other than pigment yellow 138 and pigment yellow 150, and a color other than yellow. Other coloring materials such as materials may be contained.

Pigment Yellow 138 is a compound represented by the following structural formula (A).

Pigment Yellow 150 is a compound represented by the following structural formula (B).

By using at least one selected from Pigment Yellow 138 and Pigment Yellow 150 as the coloring material contained in the yellow ink, the light resistance of the image formed by using the yellow ink can be improved. As a result, even when the printed matter is stored for a long period of time or used in an environment where the printed matter is irradiated with light, the discoloration of yellow in the printed matter is suppressed, and the printed matter having a good image can be provided. As a result, when an image is formed using an ink set having the present yellow ink, cyan ink, magenta ink, and black ink, a high-quality printed matter in which the color balance with cyan and magenta is well maintained is particularly good. Can be provided.

The content of Pigment Yellow 138 and Pigment Yellow 150 in the yellow ink is 0.1% by mass or more and 15% by mass or less with respect to the mass of the yellow ink from the viewpoint of improving the image density, good fixability and ejection stability. Is preferable, and more preferably 1% by mass or more and 10% by mass or less.

-Other color materials-
The yellow ink may contain a coloring material other than Pigment Yellow 138 and Pigment Yellow 150. The coloring material other than Pigment Yellow 138 and Pigment Yellow 150 is not particularly limited, and known pigments and dyes can be used.

As the pigment, an inorganic pigment and an organic pigment can be used. These may be used alone or in combination of two or more. Moreover, you may use a mixed crystal. As the pigment, for example, black pigment, yellow pigment, magenta pigment, cyan pigment, white pigment, green pigment, orange pigment, glossy color pigment such as gold or silver, metallic pigment and the like can be used.

Inorganic pigments include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, as well as carbon produced by known methods such as the contact method, furnace method, and thermal method. Black can be used.

Examples of organic pigments include azo pigments, polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dyes. Chelate (for example, basic dye type chelate, acid dye type chelate, etc.), nitro pigment, nitroso pigment, aniline black and the like can be used. Among these pigments, those having a good affinity with a solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.

As a specific example of the pigment, for black, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11) , Metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).

As a specific example of the pigment, for color, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Calcium 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment Violet 1 (Rhodamine Lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone or two or more types may be used in combination. Specific examples of the dye include, for example, C.I. I. Acid Red 52,80,82,249,254,289, C.I. I. Acid Blue 9,45,249, C.I. I. Acid Black 1,2,24,94, C.I. I. Food Black 1, 2, C.I. I. Direct Blue 1,2,15,71,86,87,98,165,199,202, C.I. I. Dilekdo Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive Black 3, 4, 35 can be mentioned.

The content of other coloring materials in the yellow ink is preferably 0.1% by mass or more and 15% by mass or less with respect to the mass of the yellow ink from the viewpoint of improving the image density, good fixability and ejection stability. It is preferably 1% by mass or more and 10% by mass or less.

-Pigment dispersion method-
As a method of obtaining a yellow ink by dispersing pigments such as Pigment Yellow 138 and Pigment Yellow 150, for example, a method of introducing a hydrophilic functional group into the pigment to obtain a self-dispersing pigment, or coating the surface of the pigment with a resin. A method of dispersing the ink, a method of dispersing the pigment using a dispersant, and the like can be mentioned.

Examples of the method of introducing a hydrophilic functional group into a pigment to obtain a self-dispersing pigment include a method of adding a functional group such as a sulfone group or a carboxyl group to the pigment so that the pigment can be dispersed in water.

Examples of the method of coating the surface of the pigment with a resin and dispersing the pigment include a method of encapsulating the pigment with a resin in the form of microcapsules so that the pigment can be dispersed in water. This can be rephrased as a resin coating pigment. In this case, all the pigments blended in the yellow ink do not have to be coated with the resin, and may be partially coated pigments.

Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular-weight dispersant and high-molecular-weight dispersant represented by a surfactant. The dispersant can be selected according to the pigment, and for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and the like can be used. Specific examples thereof include RT-100 (nonionic surfactant) manufactured by Takemoto Oil & Fat Co., Ltd., a naphthalene sulfonate Na formalin condensate, and the like. The dispersant may be used alone or in combination of two or more.

-Pigment dispersion-
The yellow ink can be obtained by mixing a material such as water or an organic solvent with pigments such as Pigment Yellow 138 and Pigment Yellow 150, and the pigment, water, and a dispersant are mixed to obtain a pigment dispersion. Yellow ink may be produced by additionally mixing a material such as water or an organic solvent with the ink. The pigment dispersion can be obtained, for example, by mixing and dispersing water, a pigment, a pigment dispersant, etc., and adjusting the particle size. It is preferable to use a disperser for dispersion. The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of the maximum number because the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is also high. It is preferably 500 nm or less, and more preferably 20 nm or more and 150 nm or less. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.). The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose, but is 0.1% by mass from the viewpoint of obtaining good ejection stability and increasing the image density. It is preferably 50% by mass or more, and more preferably 0.1% by mass or more and 30% by mass or less. It is preferable that the pigment dispersion is degassed by filtering coarse particles with a filter, a centrifuge, or the like, if necessary.

<Resin>
-Urethane resin particles-
The resin contained in the yellow ink is urethane resin particles, and if necessary, other resins other than urethane resin particles may be contained. By containing the urethane resin particles, it is possible to impart high image glossiness, scratch resistance, and adhesion to the image formed by the yellow ink. The reason why high image glossiness can be obtained by containing urethane resin particles is not clear, but the urethane resin particles are highly compatible with at least one selected from Pigment Yellow 138 and Pigment Yellow 150, and are formed by ink. It is presumed that the pigment is uniformly dispersed when the image is formed.
Further, in order to impart the above functions, the urethane resin is contained in the yellow ink in the form of resin particles. By containing it in the yellow ink in the form of resin particles, unlike the case where it is contained in the yellow ink in the form of a water-soluble resin, the yellow ink sufficiently wets and spreads with respect to the recording medium, resulting in a highly smooth surface. It is possible to form an image having a high image glossiness.
Examples of the urethane resin include a polyether polyurethane resin, a polycarbonate polyurethane resin, and a polyester polyurethane resin.

As the urethane resin, a manufactured product or a commercially available product may be used. Examples of commercially available products include U-coat UX-485 (polyurethane-based polyurethane resin particles), U-coat UWS-145 (polyester-based polyurethane resin particles), Permarin UA-368T (polyester-based polyurethane resin particles), and Permarin UA-200 (polyether). Polyurethane resin particles) (above, manufactured by Sanyo Kasei Kogyo Co., Ltd.) and the like. These may be used alone or in combination of two or more.

The content of the urethane resin is not particularly limited, but is preferably 12.0% by mass or less, and more preferably 8.5% by mass or less of the amount of yellow ink from the viewpoint of enhancing dispersibility. Further, when the content is 8.5% by mass or less, an image having excellent image gloss can be obtained, which is preferable. Further, the content of the urethane resin is set to 5.0% by mass or more of the mass of the yellow ink from the viewpoint of enhancing the light resistance, adhesion, scratch resistance, and image glossiness of the image formed by using the yellow ink. Is preferable.

--Various materials used in the production of urethane resin ---
The urethane resin can be obtained, for example, by reacting a polyol with a polyisocyanate.

--- Polyol ---
Examples of the polyol include a polyether polyol, a polycarbonate polyol, a polyester polyol and the like. These may be used alone or in combination of two or more.
The urethane resin is preferably a polycarbonate-based urethane resin obtained by using a polycarbonate polyol. Since the carbonate group has a high cohesive force, the yellow ink containing the polycarbonate urethane resin is excellent in water resistance, heat resistance, abrasion resistance, weather resistance, and scratch resistance. Therefore, the yellow ink containing the polycarbonate-based urethane resin is suitable for applications used in harsh environments such as outdoor applications.

Examples of the polyether polyol include those obtained by addition polymerization of an alkylene oxide using at least one compound having two or more active hydrogen atoms as a starting material.
Examples of the compound having two or more active hydrogen atoms include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylolglycol, 1,3-butanediol, 1,4-butanediol, and 1,6-hexanediol. , Glycerin, trimethylolethane, trimethylolpropane and the like. These may be used alone or in combination of two or more.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran. These may be used alone or in combination of two or more.
Specifically, as the polyether polyol, polyoxytetramethylene glycol, polyoxypropylene glycol and the like are preferable. By using these, a urethane resin as a binder capable of imparting excellent scratch resistance can be obtained.

Examples of the polycarbonate polyol include those obtained by reacting a carbonic acid ester with a polyol, those obtained by reacting phosgene with bisphenol A, and the like. These may be used alone or in combination of two or more.
Examples of the carbonic acid ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like. These may be used alone or in combination of two or more.
Examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2. -Butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcin, Relatively low molecular weight dihydroxy compounds such as bisphenol-A, bisphenol-F, 4,4'-biphenol; polyether polyols such as polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol; polyhexamethylene adipate, polyhexamethylene succi Examples thereof include polyester polyols such as nate and polycaprolactone. These may be used alone or in combination of two or more.

Examples of the polyester polyol include those obtained by esterifying a low molecular weight polyol and a polycarboxylic acid, polyester obtained by ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and copolyesters thereof. And so on. These may be used alone or in combination of two or more.
Examples of the low molecular weight polyol include ethylene glycol and propylene glycol. These may be used alone or in combination of two or more.
Examples of the polycarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecandicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, anhydrides or ester-forming derivatives thereof. These may be used alone or in combination of two or more.

--- Polyisocyanate ---
Examples of the polyisocyanate include aromatic diisocyanates such as phenylenediocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate. Examples thereof include aliphatic or alicyclic diisocyanates such as isocyanate and 2,2,4-trimethylhexamethylene diisocyanate. These may be used alone or in combination of two or more. Among these, it is preferable to use an alicyclic diisocyanate because yellow ink can form an image having long-term weather resistance when it is used for outdoor applications such as posters and signboards. Further, by using the alicyclic diisocyanate, the intensity of the image is improved and excellent scratch resistance can be obtained. Examples of the alicyclic diisocyanate include isophorone diisocyanate and dicyclohexylmethane diisocyanate. The content of the alicyclic diisocyanate is preferably 60.0% by mass or more with respect to the total amount of polyisocyanate.

--Manufacturing method of urethane resin ---
The urethane resin can be obtained by a conventionally commonly used production method, and examples thereof include the following methods.
First, the above-mentioned polyol and the above-mentioned polyisocyanate are reacted at an equivalent ratio in which the isocyanate group becomes excessive in the absence of a solvent or in the presence of an organic solvent to produce an isocyanate-terminated urethane prepolymer. The anionic groups in the isocyanate-terminated urethane prepolymer are then neutralized with a neutralizing agent as needed, then reacted with a chain extender and finally the organic solvent in the system is removed as needed. Obtain urethane resin.

--- Organic solvent ---
Examples of the organic solvent that can be used for producing the urethane resin include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; acetate esters such as ethyl acetate and butyl acetate; nitriles such as acetonitrile; dimethylformamide, Examples thereof include amides such as N-methylpyrrolidone and N-ethylpyrrolidone. These may be used alone or in combination of two or more.

--- Chain extender ---
Examples of the chain extender include polyamines and other active hydrogen group-containing compounds.
Examples of polyamines include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazin, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, and 1,4-cyclohexanediamine. Diamines such as; polyamines such as diethylenetriamine, dipropylenetriamine, triethylenetetramine; hydrazines such as hydrazine, N, N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; dihydrazide succinate, dihydrazide adipic acid, etc. Examples thereof include dihydrazides such as glutarate dihydrazide, sebacic acid dihydrazide, and isophthalic acid dihydrazide. These may be used alone or in combination of two or more.
Examples of other active hydrogen group-containing compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, and saccharose. , Glycols such as methylene glycol, glycerin, sorbitol; phenols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone, hydrogenated bisphenol A, hydroquinone, etc. ; Water and the like. These may be used alone or in combination of two or more as long as the storage stability of the yellow ink is not deteriorated.

--State of urethane resin ---
The urethane resin is present in the yellow ink in the form of urethane resin particles as described above. Such yellow ink is preferably obtained by mixing it with a material such as a coloring material or an organic solvent in the state of a resin emulsion in which water is dispersed as a dispersion medium. By blending a resin emulsion with an organic solvent, a coloring material, water, or the like to prepare a yellow ink, the ease of work and uniform dispersibility are improved.

The urethane resin particles form a film by being dissolved in an organic solvent added to the yellow ink to form a film-like recording layer (image). That is, the film formation of urethane resin particles is promoted by evaporating water from the yellow ink after applying the yellow ink. Therefore, depending on the type of urethane resin particles used, it is possible to perform recording without a heating step.

The method of dispersing the urethane resin particles in water is not particularly limited, but for example, a method of using a self-emulsifying type resin particle having an anionic group in the molecular structure and a forced emulsifying type resin particle using a dispersant. Examples include a method using. Among these, a method using self-emulsifying resin particles having an anionic group in the molecular structure is preferable from the viewpoint of increasing the strength of the recorded material.

The acid value of the anionic group when self-emulsifying urethane resin particles are used is preferably 5 mgKOH / g or more and 100 mgKOH / g or less from the viewpoint of water dispersibility, scratch resistance, and chemical resistance. More preferably, it is mg or more and 50 mgKOH / mg or less.

Examples of the anionic group include a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group and the like. Among these, carboxylate groups and sulfonate groups that are partially or wholly neutralized with a basic compound or the like are preferable from the viewpoint of maintaining good water dispersion stability. In order to introduce an anionic group into the resin, a monomer having an anionic group may be used.
Further, the anionic group is preferably neutralized with a basic compound. Examples of the basic compound include organic amines such as ammonia, triethylamine, pyridine and morpholine; alkanolamines such as monoethanolamine; and metal base compounds containing Na, K, Li, Ca and the like. These may be used alone or in combination of two or more.

Examples of the method for producing an aqueous dispersion using the forced emulsification type urethane resin particles include a method using a surfactant such as a nonionic surfactant and an anionic surfactant. These may be used alone or in combination of two or more. Among these, a method using a nonionic surfactant is preferable from the viewpoint of water resistance.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether, polyoxyethylene derivative, polyoxyethylene fatty acid ester, polyoxyethylene polyhydric alcohol fatty acid ester, polyoxyethylene propylene polyol, and sorbitan. Examples thereof include fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene hydrogenated castor oil, polyoxyalkylene polycyclic phenyl ethers, polyoxyethylene alkyl amines, alkyl alkanolamides, and polyalkylene glycol (meth) acrylates. Among these, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and polyoxyethylene alkyl amine are preferable. These may be used alone or in combination of two or more.

Examples of the anionic surfactant include alkyl sulfate ester salts, polyoxyethylene alkyl ether sulfate salts, alkylbenzene sulfonates, α-olefin sulfonates, methyl tauryl salts, sulfosuccinates, ether sulfonates, and ether carboxylic salts. Examples thereof include acid salts, fatty acid salts, sodium sulfonate formalin condensates, alkylamine salts, quaternary ammonium salts, alkylbetaines, alkylamine oxides and the like. Among these, polyoxyethylene alkyl ether sulfate and sulfosuccinate are preferable.

When an aqueous dispersion is produced using forced emulsified urethane resin particles, the content of the surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. However, forced emulsified urethane resin is used. It is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less with respect to the total amount of particles. When the content is in the range of 0.1% by mass or more and 30% by mass or less, urethane resin particles are preferably formed into a film, yellow ink having excellent adhesion and water resistance can be obtained, and the recorded material is blocked. It is preferably used without any problem.

--Various physical characteristics of urethane resin ---
The volume average particle diameter of the urethane resin particles is preferably 10 nm or more and 1,000 nm or less, more preferably 10 nm or more and 500 nm or less, and further preferably 10 nm or more and 200 nm or less, considering that it is used in an inkjet recording apparatus. When the volume average particle diameter is 10 nm or more and 1,000 nm or less, the contact portion between the organic solvent and the surface of the urethane resin particles increases, the film-forming property of the urethane resin particles is enhanced, and a continuous coating of tough resin is formed. Therefore, a high-strength recorded material can be obtained. The volume average particle size can be measured using, for example, a particle size analyzer (Microtrack MODEL UPA9340, manufactured by Nikkiso Co., Ltd.).

As for the qualitative and quantitative analysis of resins, for example, "Test method and evaluation result of each dynamic property of plastic materials (22); by Takeo Yasuda, Plastics: Journal of Japan Plastic Industry Federation / Editorial Committee of" Plastics "" It can be confirmed by the procedure as described in detail. Specifically, it can be confirmed by analysis by infrared spectroscopic analysis (IR), thermal analysis (DSC, TG / DTA), thermal decomposition gas chromatography (PyGC), nuclear magnetic resonance (NMR), or the like.

The glass transition temperature of the urethane resin can be measured using a differential scanning calorimeter (DSC6200, manufactured by Seiko Instruments Co., Ltd.). Specifically, the measurement is performed under the conditions of the following continuous temperature programs 1 to 4, and the value measured by the temperature program 3 is defined as the glass transition temperature. The measured value of the temperature program 3 is used in order to ensure the reproducibility of the measured value.
Temperature program:
(1) 30 ° C or higher and 250 ° C or lower: temperature rise rate of 30 ° C / min, holding time of 1 minute (2) 250 or higher and -100 ° C or lower: cooling rate of 30 ° C / min, holding time of 30 minutes (3) -100 or higher and 250 ° C or lower: heating rate 5 ° C / min, holding time 1 minute (4) 250 or more and 30 ° C or lower: cooling rate 30 ° C / min, holding time 2 minutes

The minimum film-forming temperature of the urethane resin (hereinafter, also referred to as "MFT") is not particularly limited. However, when the minimum film-forming temperature exceeds 80 ° C., it is preferable to heat the yellow ink after application from the viewpoint that the film-forming defect of the resin can be improved and the image fastness can be improved.
When adjusting the minimum film-forming temperature, for example, it can be adjusted by controlling the glass transition temperature of the urethane resin (hereinafter, also referred to as "Tg"), and when the urethane resin is a copolymer. Can be adjusted by changing the ratio of the monomers forming the copolymer. The minimum film forming temperature is the minimum temperature at which a transparent continuous film is formed when a urethane resin is thinly cast on a metal plate such as aluminum and the temperature is raised. In the temperature range below the film temperature, the emulsion becomes a white powder. The minimum film-forming temperature is measured by, for example, a commercially available minimum film-forming temperature measuring device such as "film-forming temperature test device" (manufactured by Imoto Seisakusho Co., Ltd.) and "TP-801 MFT tester" (manufactured by Tester Sangyo Co., Ltd.). be able to. Further, since the minimum film-forming temperature changes depending on the volume average particle size of the resin, the minimum film-forming temperature of the resin can be set as a target value by a control factor of the volume average particle size of the resin.

-Other resins-
If necessary, the resin other than the urethane resin particles that may be contained in the yellow ink is not particularly limited, but for example, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, etc. Examples thereof include styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, and acrylic silicone resin. These may be used alone or in combination of two or more.

<Water>
The yellow ink of the present embodiment preferably contains water. The content of water in the yellow ink is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of the drying property and ejection reliability of the yellow ink, 10% by mass or more with respect to the total amount of the yellow ink. 90% by mass or less is preferable, and 20% by mass or more and 60% by mass or less is more preferable.

<Organic solvent>
The organic solvent used for the yellow ink is not particularly limited, but a liquid organic solvent at 25 ° C. and 1 atm can be preferably used. For example, ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds can be used.

Specific examples of the organic solvent include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and the like. 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2 , 4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1, Polyhydric alcohols such as 3-pentanediol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. Polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1 , 3-Dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds, formamide, N-methylformamide and other amides, monoethanolamine, diethanolamine, triethylamine and other amines, dimethyl Examples thereof include sulfur-containing compounds such as sulfoxide, sulfolane and thiodiethanol, propylene carbonate and ethylene carbonate.

As the organic solvent, a polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used.
Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Ethers: Polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether can be mentioned.
The polyol compound and the glycol ether compound having 8 or more carbon atoms can improve the permeability of the yellow ink when paper is used as the recording medium.

The content of the organic solvent in the yellow ink is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of the drying property and ejection reliability of the yellow ink, 10. It is preferably 0% by mass or more and 60.0% by mass or less, and more preferably 20.0% by mass or more and 60.0% by mass or less.

-Compound represented by the general formula (2)-
As the organic solvent, a compound represented by the following general formula (2) is also preferably used. By containing the compound represented by the general formula (2) in the yellow ink, the image glossiness of the image formed by using the yellow ink can be improved. The compound represented by the general formula (2) functions as a film-forming auxiliary, and specifically contributes to the smoothing of urethane resin particles after the yellow ink is applied to the recording medium, resulting in an image of an image. Improves glossiness. Further, when a non-permeable base material such as a vinyl chloride resin film is used as the recording medium, the compound represented by the general formula (2) improves the wettability of the yellow ink to the non-permeable base material. As a result, the image glossiness of the image is improved.

In the general formula (2), R ₁ , R ₂ , and R ₃ independently represent hydrocarbon groups having 1 or more and 8 or less carbon atoms. Specific examples thereof include 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide and the like.

The content of the compound represented by the general formula (2) is preferably 1.0% by mass or more and 20.0% by mass or less, and 3.0% by mass or more and 10% by mass, based on the total amount of the yellow ink. It is more preferably 0.0% by mass or less, and further preferably 5.0% by mass or more and 10.0% by mass or less.

<Siloxane compound represented by the general formula (1)>
The yellow ink preferably contains a siloxane compound represented by the following general formula (1). The siloxane compound represented by the general formula (1) can function as a surfactant by being contained in the yellow ink. Further, when the yellow ink contains the siloxane compound represented by the general formula (1), the image glossiness is improved in the image formed by the yellow ink. The siloxane compound represented by the general formula (1) may be used alone or in combination of two or more.

R in the general formula (1) represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and is preferably a hydrogen atom.

Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, a t-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Group etc. can be mentioned.

In the general formula (1), a, b, c, n, and m represent integers, a, c, and m each independently represent an integer of 0 or more, and b and n each independently represent 1 or more. Represents an integer of. Further, in the general formula (1), "a + b + c + n + m" is preferably 500 or less, more preferably 100 or less, and further preferably 50 or less.

In addition, a, b, c, n, and m in the general formula (1) preferably satisfy the following formula “(a + b + c) / (n + m) ≧ 0.5”, and “2.0 ≧ (a + b + c) / It is more preferable that (n + m) ≥ 0.5 ", and even more preferably" 1.5 ≥ (a + b + c) / (n + m) ≥ 0.5 ", and" 1.0 ≥ (a + b + c) / (n + m). ) ≧ 0.5 ”is particularly preferable. A siloxane compound satisfying "(a + b + c) / (n + m) ≥ 0.5" can improve the wettability of the yellow ink containing this compound to a recording medium, and thus has fixability in an image formed by the yellow ink. And the image glossiness is improved.

The molecular weight of the siloxane compound represented by the general formula (1) is preferably 2000 or more and 30,000 or less, and more preferably 2000 or more and 5000 or less.

The content of the siloxane compound represented by the general formula (1) is preferably 0.1% by mass or more and 4.0% by mass or less, and 1.0% by mass or more and 2.0% by mass, based on the mass of the yellow ink. The following is more preferable. When it is 0.1% by mass or more and 4.0% by mass or less, the adhesion of the image to the impermeable substrate is improved and the image quality such as image gloss is also improved when used in combination with the urethane resin.

Commercially available products of the siloxane compound represented by the general formula (1) include, for example, KF-353, KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.) and the like can be mentioned.

<Surfactant>
As the surfactant, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.

The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Of these, those that do not decompose even at high pH are preferable. Examples of the silicone-based surfactant include side chain-modified polydimethylsiloxane, double-ended polydimethylsiloxane, single-ended modified polydimethylsiloxane, and side-chain double-ended modified polydimethylsiloxane. Those having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as the modifying group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the Si side chain of dimethylsiloxane.

Examples of the fluorine-based surfactant 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 in the side chain. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a poly having a perfluoroalkyl ether group in the side chain. Examples thereof include salts of oxyalkylene ether polymers. The counter ions of the salts in these fluorine-based surfactants are Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH). _3rd grade can be mentioned.

Examples of amphoteric surfactants include laurylaminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.

Examples of the nonionic surfactant include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include a fatty acid ester and an ethylene oxide adduct of acetylene alcohol.

Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, salt of polyoxyethylene alkyl ether sulfate, and the like.

（但し、一般式（Ｓ−１）式中、ｍ、ｎ、ａ、及びｂは、それぞれ独立に、整数を表わし、Ｒは、アルキレン基を表し、Ｒ’は、アルキル基を表す。）
上記のポリエーテル変性シリコーン系界面活性剤としては、市販品を用いることができ、例えば、ＫＦ−６１８、ＫＦ−６４２、ＫＦ−６４３（信越化学工業株式会社）、ＥＭＡＬＥＸ−ＳＳ−５６０２、ＳＳ−１９０６ＥＸ（日本エマルジョン株式会社）、ＦＺ−２１０５、ＦＺ−２１１８、ＦＺ−２１５４、ＦＺ−２１６１、ＦＺ−２１６２、ＦＺ−２１６３、ＦＺ−２１６４（東レ・ダウコーニング・シリコーン株式会社）、ＢＹＫ−３３、ＢＹＫ−３８７（ビックケミー株式会社）、ＴＳＦ４４４０、ＴＳＦ４４５２、ＴＳＦ４４５３（東芝シリコン株式会社）などが挙げられる。 The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side-chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, side chain. Examples thereof include both-terminal modified polydimethylsiloxane, and a polyether-modified silicone-based surfactant having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as modifying groups is particularly preferable because it exhibits good properties as an aqueous surfactant. ..
As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. As commercially available products, for example, they can be obtained from Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd., and the like.
The above-mentioned polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the general formula (S-1) is dimethylpoly. Examples thereof include those introduced into the Si part side chain of siloxane.

(However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R'represents an alkyl group.)
Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (Shinetsu Chemical Industry Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.) and the like can be mentioned.

上記一般式（Ｆ−１）で表される化合物において、水溶性を付与するためにｍは０〜１０の整数が好ましく、ｎは０〜４０の整数が好ましい。

上記一般式（Ｆ−２）で表される化合物において、ＹはＨ、又はＣｍＦ_２ｍ＋１でｍは１〜６の整数、又はＣＨ_２ＣＨ（ＯＨ）ＣＨ_２−ＣｍＦ_２ｍ＋１でｍは４〜６の整数、又はＣｐＨ_２ｐ＋１でｐは１〜１９の整数である。ｎは１〜６の整数である。ａは４〜１４の整数である。
上記のフッ素系界面活性剤としては市販品を使用してもよい。この市販品としては、例えば、サーフロンＳ−１１１、Ｓ−１１２、Ｓ−１１３、Ｓ−１２１、Ｓ−１３１、Ｓ−１３２、Ｓ−１４１、Ｓ−１４５（いずれも、旭硝子株式会社製）；フルラードＦＣ−９３、ＦＣ−９５、ＦＣ−９８、ＦＣ−１２９、ＦＣ−１３５、ＦＣ−１７０Ｃ、ＦＣ−４３０、ＦＣ−４３１（いずれも、住友スリーエム株式会社製）；メガファックＦ−４７０、Ｆ−１４０５、Ｆ−４７４（いずれも、大日本インキ化学工業株式会社製）；ゾニール（Ｚｏｎｙｌ）ＴＢＳ、ＦＳＰ、ＦＳＡ、ＦＳＮ−１００、ＦＳＮ、ＦＳＯ−１００、ＦＳＯ、ＦＳ−３００、ＵＲ、キャプストーンＦＳ−３０、ＦＳ−３１、ＦＳ−３１００、ＦＳ−３４、ＦＳ−３５（いずれも、Ｃｈｅｍｏｕｒｓ社製）；ＦＴ−１１０、ＦＴ−２５０、ＦＴ−２５１、ＦＴ−４００Ｓ、ＦＴ−１５０、ＦＴ−４００ＳＷ（いずれも、株式会社ネオス社製）、ポリフォックスＰＦ−１３６Ａ，ＰＦ−１５６Ａ、ＰＦ−１５１Ｎ、ＰＦ−１５４、ＰＦ−１５９（オムノバ社製）、ユニダインＤＳＮ−４０３Ｎ（ダイキン工業株式会社製）などが挙げられ、これらの中でも、良好な印字品質、特に発色性、紙に対する浸透性、濡れ性、均染性が著しく向上する点から、Ｃｈｅｍｏｕｒｓ社製のＦＳ−３１００、ＦＳ−３４、ＦＳ−３００、株式会社ネオス製のＦＴ−１１０、ＦＴ−２５０、ＦＴ−２５１、ＦＴ−４００Ｓ、ＦＴ−１５０、ＦＴ−４００ＳＷ、オムノバ社製のポリフォックスＰＦ−１５１Ｎ及びダイキン工業株式会社製のユニダインＤＳＮ−４０３Ｎが特に好ましい。 As the fluorine-based surfactant, a compound having 2 to 16 carbon atoms substituted with fluorine is preferable, and a compound having 4 to 16 carbon atoms substituted with fluorine is more preferable.
Examples of the fluorosurfactant include a perfluoroalkyl phosphate ester compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because it has low foaming property, and is particularly a fluorine-based compound represented by the general formula (F-1) and the general formula (F-2). Surfactants are preferred.

In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility.

In the compound represented by the above general formula (F-2), Y is H or CmF _{2m + 1} and m is an integer of 1 to 6, or CH ₂ CH (OH) CH _2- CmF _{2m + 1} and m is 4 to 6. It is an integer, or CpH _{2p + 1} and p is an integer of 1-19. n is an integer of 1-6. a is an integer of 4 to 14.
Commercially available products may be used as the above-mentioned fluorine-based surfactant. Examples of this commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Co., Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by Dainippon Ink and Chemicals Co., Ltd.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by The Chemours Company); FT-110, FT-250, FT-251, FT-400S, FT-150, FT- 400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries Co., Ltd.) Among these, the Chemours FS-3100, FS-34, and FS- 300, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Co., Ltd., Polyfox PF-151N manufactured by Omniova Co., Ltd. and Unidyne DSN-manufactured by Daikin Industries Co., Ltd. 403N is particularly preferable.

The content of the surfactant in the yellow ink is not particularly limited and may be appropriately selected depending on the intended purpose. However, 0.001 is obtained because it is excellent in wettability and ejection stability and the image quality is improved. It is preferably by mass% or more and 5% by mass or less, and more preferably 0.05% by mass or more and 5% by mass or less.

<Additives>
If necessary, a defoaming agent, an antiseptic antifungal agent, a rust preventive agent, a pH adjusting agent and the like may be added to the yellow ink.

-Defoamer-
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because it has an excellent defoaming effect.

-Preservatives and fungicides-
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

-Rust inhibitor-
The rust preventive is not particularly limited, and examples thereof include acidic sulfite and sodium thiosulfate.

-PH regulator-
The pH adjusting agent is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

<Physical characteristics of yellow ink>
The physical characteristics of the yellow ink are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosity of the yellow ink at 25 ° C. is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less, from the viewpoint of improving the print density and character quality and obtaining good ejection properties. Is more preferable. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. As the measurement conditions, it is possible to measure at 25 ° C. with a standard cone rotor (1 ° 34'x R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The surface tension of the yellow ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the yellow ink is preferably leveled on the recording medium and the drying time of the yellow ink is shortened. ..
The pH of the yellow ink is preferably 7 to 12, more preferably 8 to 11, from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

<< Ink set >>
The yellow ink can be used as an ink set by combining with cyan ink, magenta ink, and black ink. The ink set may further include inks having colors other than yellow ink, cyan ink, magenta ink, and black ink.

<< Recording medium >>
The recording medium is not particularly limited, and plain paper, glossy paper, special paper, cloth, or the like can be used, but good image formation can be achieved even if a non-permeable base material is used.
The non-permeable base material is a base material having a surface having low water permeability and low absorbability, and includes a material that does not open to the outside even if there are many cavities inside, and more quantitatively, A substrate having a water absorption of 10 mL / m ² or less from the start of contact to 30 msec ^{1/2 in the Bristow method.}
As the impermeable substrate, for example, a plastic film such as a vinyl chloride resin film, a polyethylene terephthalate (PET) film, polypropylene, polyethylene, or a polycarbonate film can be preferably used.

Examples of non-permeable substrates using polypropylene and polyethylene include AR1025, AR1056, AR1082, EC1082, 1082D, 1073D, 1056D, 1025D, FR1073 (Asahi Dupont Flashspan Products Co., Ltd.), P2002, P2102, P2108, P2161, P2171, P2111, P4266, P5767, P3162, P6181, P8121, P1162, P1111, P1128, P1181, P1153, P1157, P1146, P1147, P1171 (Toyobo Co., Ltd.), YPI, Aqua Yupo, Super Yupo, Ultra Yupo, New Yupo, Examples include YUPO lighting paper, YUPO building materials paper, YUPO polypropylene, YUPO JET, and metallic YUPO (YUPO Corporation).

<< Recorded material >>
The recording material has a recording medium and a printing layer formed on the recording medium, and has other layers as needed. Since the print layer is formed by using the yellow ink of the present embodiment, it contains the resin and the coloring material contained in the yellow ink.

<< Recording device, recording method >>
The yellow ink of the present embodiment can be suitably used for various recording devices by an inkjet recording method, for example, a printer, a facsimile device, a copying device, a printer / fax / copier multifunction device, a three-dimensional modeling device, and the like.
The recording device and recording method are devices capable of ejecting ink, various processing liquids, and the like to a recording medium, and a method of recording using the device. The recording medium means a medium to which ink and various treatment liquids can adhere even temporarily.
This recording device can include not only a head portion for ejecting ink, but also means related to feeding, transporting, and discharging paper of a recording medium, and other devices called pretreatment devices and posttreatment devices. ..
The recording device and recording method may include a heating means used in the heating step and a drying means used in the drying step. The heating means and the drying means include, for example, means for heating and drying the print surface and the back surface of the recording medium. The heating means and the drying means are not particularly limited, but for example, a hot air heater and an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.
When an infrared heater is used as the heating means and the drying means, it is provided with at least a near-infrared irradiation device. As a near-infrared irradiation device, a device including a halogen lamp and a reflection mirror is known. A halogen heater is built into the reflection mirror and made into a heating unit to realize efficient heating. For example, UH-USC-CL300, UHUSC-CL700, UH-USC-CL1000, UH -USD-CL300, UHUSD-CL700, UH-USD-CL1000, UH-MA1-CL300, UHMA1-CL700, UH-MA1-CL1000 (all manufactured by Ushio, Inc.) and the like.
Further, the recording device and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, those that form patterns such as geometric patterns and those that form a three-dimensional image are also included.
Further, the recording device includes both a serial type device that moves the discharge head and a line type device that does not move the discharge head, unless otherwise specified.
Further, as this recording device, it is possible to use not only a desktop type but also a wide recording device capable of printing on an A0 size recording medium, or, for example, continuous paper wound in a roll shape as a recording medium. A continuous line printer is also included.

An example of the recording device will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective explanatory view of the main tank. The image forming apparatus 400 as an example of the recording apparatus is a serial type image forming apparatus. A mechanism portion 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink storage section 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is, for example, a package of an aluminum laminated film or the like. It is formed of members. The ink container 411 is housed in, for example, a plastic container case 414. As a result, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided behind the opening when the cover 401c of the apparatus main body is opened. A main tank 410 is detachably attached to the cartridge holder 404. As a result, each ink ejection port 413 of the main tank 410 and the ejection head 434 for each color communicate with each other via the supply tube 436 for each color, and ink can be ejected (applied) from the ejection head 434 to the recording medium. ..

The method of using the ink is not limited to the inkjet recording method, and can be widely used. In addition to the inkjet recording method, examples thereof include a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and a spray coating method.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples. Unless otherwise specified, the operations in the following preparation examples and evaluations were performed in an environment of room temperature of 25 ° C. and humidity of 60%.

<Preparation example of yellow pigment dispersion>
-Preparation example of yellow pigment dispersion 1-
After premixing the following formulation mixture, it was circulated and dispersed for 7 hours in a disc type bead mill (manufactured by Simmal Enterprises Co., Ltd., KDL type, media: using zirconia balls with a diameter of 0.3 mm) to yellow pigment dispersion 1 (pigment). Solid content concentration: 20% by mass) was obtained.
-Yellow pigment (trade name: Hostaperm Yellow HN4G (Pigment Yellow 150), manufactured by Clariant): 20.0 parts by mass-Anionic surfactant (trade name: Pionin A-51-B, manufactured by Takemoto Oil & Fat Co., Ltd.): 2.0 parts by mass ・ Ion-exchanged water: 78.0 parts by mass

-Preparation example of yellow pigment dispersion 2-
In the preparation example of the yellow pigment dispersion 1, the yellow pigment dispersion was prepared by the same method as the preparation example of the yellow pigment dispersion 1 except that the yellow pigment was changed to "Pariotor Yellow D0960 (Pigment Yellow 138), manufactured by BASF". 2 (pigment solid content concentration: 20% by mass) was obtained.

-Preparation example of yellow pigment dispersion 3-
In the preparation example of the yellow pigment dispersion 1, the yellow pigment dispersion was carried out by the same method as the preparation example of the yellow pigment dispersion 1 except that the yellow pigment was changed to "Hansa Yellow 5GX01 (Pigment Yellow 74), manufactured by Clariant". 3 (Pigment solid content concentration: 20% by mass) was obtained.

<Yellow ink adjustment example>
(Example 1)
With the following formulation, ion-exchanged water was added so as to make a total of 100 parts by mass, and after the formulation, the mixture was mixed and stirred, and filtered through a 5 μm filter (Minisalt manufactured by Sartorius) to obtain the yellow ink of Example 1.
-Yellow pigment dispersion 1: 15.0 parts by mass-Superflex 300 (polyurethane resin particle dispersion, resin solid content concentration: 30% by mass, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 23.3 parts by mass-KF-353 (Siloxane compound, manufactured by Shin-Etsu Silicone Co., Ltd.): 1.0 part by mass ・ 1,2-propanediol: 10.0 parts by mass ・ 1,3-butanediol: 10.0 parts by mass ・ 3-methoxy-N, N- Dimethylpropionamide: 5.0 parts by mass ・ 3-methoxy-3-methylbutanol: 5.0 parts by mass ・ Proxel LV (preservative, manufactured by Abyssia): 0.1 parts by mass ・ Ion exchange water: remaining amount

(Examples 2 to 5, Comparative Examples 1 to 2)
The yellow inks of Examples 2 to 5 and Comparative Examples 1 and 2 were prepared in the same manner as the yellow ink of Example 1 with the formulations shown in Table 1. In Table 1, since each numerical value relating to the coloring material and the resin represents the total amount, the solid content amount relating to the coloring material and the resin is a value obtained by adding the solid content concentration to these numerical values. The unit of each numerical value is parts by mass, and the total amount of each yellow ink is 100 parts by mass.

The following materials were used for each component in the table.
WBR-2122C (Polyurethane resin particle dispersion, resin solid content concentration: 30% by mass, manufactured by Taisei Fine Chemical Co., Ltd.)
-J-450 (Styrene-acrylic resin particle dispersion, resin solid content concentration: 42% by mass, manufactured by Johnson Polymer Co., Ltd.)
・ FS300 (Fluorine-based surfactant, manufactured by DuPont)

Using the obtained yellow ink, "light resistance", "adhesion", "scratch resistance", and "image glossiness" were evaluated as follows. The results are shown in Table 2.

[Formation of solid image]
The adjusted yellow ink is filled in an inkjet printer (device name: IPSiO GXe5500 modified machine, manufactured by Ricoh Co., Ltd.), and a record of a polyvinyl chloride film (CPPVWP1300, manufactured by Sakurai Co., Ltd., hereinafter also referred to as "PVC film"). A solid image was recorded so that the amount of yellow ink adhered to the medium was 0.6 g / cm ^2. After recording, the solid image was dried on a hot plate (NINOS ND-1, manufactured by AS ONE Corporation) at 80 ° C. for 1 hour.
The IPSiO GXe5500 modified machine is a modified IPSiO GXe5500 machine so that ^{a record equivalent to a recording speed of 30 m 2} / hr can be reproduced in A4 size with a printing width of 150 cm. The IPSiO GXe5500 remodeling machine is also equipped with the above hot plate, and is remodeled so that the heating conditions (heating temperature, heating time) after recording can be changed.

<Light resistance>
For a solid image formed on a PVC film, an Atlas weatherometer Ci3000 was used in an environment of 70 ° C., 50% RH, and a black panel temperature of 89 ° C., and the xenon irradiance of 0.51 W / m ² (approx. Irradiation at 340 nm) for 500 hours was performed, and fading or color change before and after irradiation was judged based on the following evaluation criteria, and the “light resistance” of the solid image was evaluated. It is desirable in actual use that the evaluation is B or higher.
〔Evaluation criteria〕
A: Almost no change B: Small fading or color change is observed C: Large fading or color change is observed

<Adhesion>
In the formation of the solid image, a solid image was formed in the same manner except that a polypropylene film (P2161, manufactured by Toyobo, hereinafter may also be referred to as “PP film”) was used instead of the PVC film. Next, the number of remaining squares of 100 test squares was counted by a grid peeling test using a cloth adhesive tape (123LW-50 manufactured by Nichiban Co., Ltd.) on the formed solid image, and the following evaluation criteria were used. Based on this, the "adhesion" to the recording medium was evaluated. It is desirable in actual use that the evaluation is B or higher.
〔Evaluation criteria〕
AA: Number of remaining cells is 98 or more A: Number of remaining cells is 90 or more and less than 98 B: Number of remaining cells is 70 or more and less than 90 C: Number of remaining cells is less than 70

<Scratch resistance>
The solid image formed on the PVC film was rubbed with a cotton cloth 10 times, and the degree of pigment transfer to the cotton cloth was visually observed and evaluated according to the following criteria. It is desirable that the evaluation is B or higher.
〔Evaluation criteria〕
A: Pigment transfer to cotton cloth is rarely seen B: Some pigment transfer is seen C: Pigment is clearly transferred

<Image glossiness>
The 60 ° glossiness of a solid image formed on a PVC film was measured four times with a glossiness meter (manufactured by BYK Gardener, 4501), the average value of the gloss values was calculated, and based on the following evaluation criteria, "image glossiness" was obtained. Was evaluated. It is desirable that the evaluation is B or higher.
〔Evaluation criteria〕
AA: Gloss value is 100 or more A: Gloss value is 90 or more and less than 100 B: Gloss value is 80 or more and less than 90 C: Gloss value is less than 80

Examples 1 and 2 are preferable embodiments, and are excellent in light resistance and adhesion, high image glossiness can be obtained even when printed on a non-penetrating recording medium, and an image having scratch resistance can be obtained. You can see that.
Example 3 is an example in which the siloxane compound represented by the general formula (1) is not contained, and the result is that the image glossiness is slightly inferior to that of Examples 1 and 2.
Example 4 is an example not containing the compound represented by the general formula (2), and the result is that the image glossiness is slightly inferior to that of Examples 1 and 2.
Example 5 is an example in which the amount of urethane resin particles added is slightly small, and the results are that the light resistance, adhesion, scratch resistance, and image glossiness are slightly inferior to those of Examples 1 and 2.

Comparative Example 1 is an example not containing PY150 or PY138, and the result is that the light resistance is inferior to that of the Example.
Comparative Example 2 is an example in which urethane resin particles are not contained, and the results are that the adhesion, scratch resistance, and image glossiness are inferior to those of the examples.

From the results in Table 2 above, it can be seen that the yellow ink of this embodiment is suitable for outdoor use. Further, it can be seen that the yellow ink of the present embodiment is excellent in light resistance and image glossiness, and is also excellent in adhesion and scratch resistance.

400 Image forming device 401 Image forming device exterior 401c Device body cover 404 Cartridge holder 410 Main tank 410k, 410c, 410m, 410y For each color of black (K), cyan (C), magenta (M), yellow (Y) Main tank 411 Ink storage unit 413 Ink discharge port 414 Storage container case 420 Mechanical unit 434 Discharge head 436 Supply tube

Japanese Unexamined Patent Publication No. 2004-2715

Claims (10)

A yellow ink containing water, resin, and coloring material.
The resin is urethane resin particles.
The coloring material is a yellow ink having at least one of Pigment Yellow 138 and Pigment Yellow 150. The yellow ink according to claim 1, further containing a siloxane compound represented by the following general formula (1).

(In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms, a, c, and m each independently represent an integer of 0 or more, and b and n are independent of each other. Represents an integer of 1 or more.) The yellow ink according to claim 1 or 2, further containing a compound represented by the following general formula (2).

(In the general formula (2), R ₁ , R ₂ , and R ₃ each independently represent a hydrocarbon group having 1 or more and 8 or less carbon atoms.) The yellow ink according to any one of claims 1 to 3, wherein the content of the urethane resin particles is 5.0% by mass or more with respect to the mass of the yellow ink. The content of the siloxane compound represented by the general formula (1) is 1.0% by mass or more and 2.0% by mass or less with respect to the mass of the yellow ink according to any one of claims 1 to 4. Described yellow ink. An ink set comprising the yellow ink, cyan ink, magenta ink, and black ink according to any one of claims 1 to 5. An ink container containing the yellow ink according to any one of claims 1 to 5. A recording apparatus comprising the ink containing container according to claim 7 and an ink applying means for applying the contained yellow ink to a recording medium. The recording apparatus according to claim 8, wherein the recording medium is a non-permeable base material. A recording method comprising an ink applying step of applying the yellow ink according to any one of claims 1 to 5 to a recording medium.

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