JP2018123181A - Inkjet ink and dyed product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inkjet ink in which storage stability and discharge stability are improved, and a dyed product dyed with the ink.SOLUTION: Inkjet ink contains a coloring material, a dispersant and water. The dispersant satisfies expressions (1) and (2), when a molecular weight (molecular weight at UV absorption wavelength maximum time) is defined as Ba when a y-axis value is maximum, a UV absorption wavelength (UV absorption wavelength maximum value) is defined as Bb when a y-axis value is maximum, a molecular weight (molecular weight at UV absorption intensity maximum time) is defined as Aa when a z-axis value is maximum, and a UV absorption wavelength (UV absorption wavelength at the UV absorption intensity maximum time) corresponding to Aa is defined as Ab in three-dimensional contour lines being drawn from right above a z-axis and represented by an x-axis; time (molecular weight), a y-axis; a UV wavelength, and the z-axis; intensity (AU) in the molecular weight of the dispersant measured by a GPC(Gel Permeation Chromatography) method by using an ultraviolet absorbance detector and an ultraviolet absorption spectrum corresponding to the molecular weight. |Bb-Ab|≥50[nm] (1) 1000≤|Ba-Aa|≤30000 (2)SELECTED DRAWING: None

Description

  The present invention relates to an inkjet ink and a dyed product.

  Ink-jet printing (hereinafter referred to as ink-jet printing) is capable of producing high-resolution printed materials compared to conventional printing (hereinafter referred to as analog printing), as well as low-cost, high-mix low-volume production and short delivery times. It has attracted attention in recent years. One of the coloring materials used in ink jet printing and analog printing is a disperse dye. Inks using disperse dyes adsorb a dispersing agent to atomized color materials, thereby suppressing aggregation and sedimentation in the ink and ensuring long-term storage stability. Thus, the dispersant used for dispersing the coloring material is an important factor in storage stability, and various compounds have been studied conventionally. For example, Patent Document 1 discloses a dispersant in which the total amount of a naphthalene sulfonic acid component and a naphthalene disulfonic acid component in a naphthalene sulfonic acid formalin condensate is 20% by mass or less.

JP2015-189821

  However, the ink using the dispersant described in Patent Document 1 has a problem that the storage stability of the ink tends to be lowered. Specifically, in the above-described dispersant using naphthalenesulfonic acid formalin condensate, when there are few types of monomers constituting the dispersant, the condensation parameter value tends to be narrow when condensed to form a dispersant. Therefore, when used as a dispersant, it is difficult to match the solubility parameter value of the color material, and the adsorption of the dispersant to the color material may become unstable. For this reason, the dispersing agent may be detached and the color material may be aggregated under a high temperature environment or the like, resulting in a decrease in ink ejection stability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that an ink containing a dispersant having both a specific UV absorption wavelength and a molecular weight distribution can solve the above-described problems. Completed.

[Application Example 1] The ink-jet ink according to this application example is an ink-jet ink containing a coloring material, a dispersant, and water, and the dispersant is measured by a GPC (Gel Permeation Chromatography) method using an ultraviolet absorbance detector. In the ultraviolet absorption spectrum corresponding to the molecular weight and the molecular weight of the dispersant, the x-axis: time (molecular weight), y-axis: UV wavelength, z-axis: directly above the three-dimensional z-axis represented by intensity (AU) In the drawn contour lines, the molecular weight when the y-axis value is max (molecular weight when the UV absorption intensity is maximum) is Ba, the UV absorption wavelength (UV absorption wavelength maximum value) when the y-axis value is max is Bb, and the z-axis value. When A is max, the molecular weight (molecular weight at the maximum UV absorption intensity) is Aa, and the UV absorption wavelength (UV absorption wavelength at the maximum UV absorption intensity) corresponding to Aa is Ab. , Formula (1), satisfying the (2).
| Bb−Ab | ≧ 50 [nm] (1)
1000 ≦ | Ba−Aa | ≦ 30000 (2)

  Application Example 2 In the ink-jet ink described in the application example, it is preferable that the molecular weight Aa and the molecular weight Ba are both 1000 or more.

  Application Example 3 In the ink-jet ink described in the above application example, the dispersant preferably includes one or more aromatic rings in the molecular structure.

  [Application Example 4] In the ink-jet ink described in the above application example, the dispersant is a formalin condensate of aromatic sulfonate or lignin sulfonate, acrylic resin, styrene-acrylic resin, styrene-maleic acid type. It is preferably one or more selected from the group of resins.

  Application Example 5 In the ink-jet ink described in the above application example, it is preferable that the coloring material is water-insoluble or hardly water-soluble.

  Application Example 6 In the ink-jet ink described in the application example, the color material is preferably a disperse dye.

  Application Example 7 The dyed product according to this application example is preferably dyed using the inkjet ink containing the disperse dye described in the above application example.

The three-dimensional graph figure which shows the measurement data by GPC method of the dispersing agent which concerns on embodiment. The two-dimensional graph figure which shows the measurement data by the GPC method of a dispersing agent. The two-dimensional graph figure which shows the measurement data by the GPC method of a dispersing agent.

  Hereinafter, embodiments of the present invention will be described in detail. The following description is an example of an embodiment of the present invention, and the present invention is not limited to this.

[Inkjet ink]
The ink-jet ink according to the present embodiment (hereinafter also referred to as “ink”) contains a coloring material, a dispersant described later, and water. Hereinafter, each component of the ink will be described.

(Color material)
As the color material contained in the ink of the present embodiment, a dye can be employed. As such a coloring material, it is preferable to use a water-insoluble or hardly water-soluble dye.

  As the pigment, any of known organic pigments and inorganic pigments can be used. Examples of organic pigments include azo pigments such as azo lake pigments, insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, and isoindolinone pigments. Polycyclic pigments such as isoindoline pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, dye lake pigments such as basic dye type lakes, acid dye type lakes, nitro pigments, nitroso pigments, aniline black, daylight fluorescent pigments, etc. Is mentioned. Examples of the inorganic pigment include metal oxide pigments such as titanium dioxide, zinc oxide, and chromium oxide, and carbon black.

  As the water-insoluble or poorly water-soluble dye, a disperse dye is preferably used. By using disperse dyes, it is possible to print on hydrophobic synthetic fibers such as polyester, acetate and nylon. The disperse dye is a dye which is insoluble or hardly soluble in water and is used in printing by making it into a water-dispersed state using a surfactant such as a dispersant.

  Examples of commercially available disperse dyes include Oraset Yellow 8GF (trade name, manufactured by Ciba Geigy, CI Disperse Yellow 82), Eisenzot Yellow 5 (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I. I. Disperse Yellow 3), Sumiplus Yellow HLR (trade name, manufactured by Sumitomo Chemical Co., Ltd., CI Disperse Yellow 54), Kayaset Yellow AG (trade name, manufactured by Nippon Kayaku Co., Ltd.) CI Disperse Yellow 54), Dialresin Yellow H2G (trade name, manufactured by Mitsubishi Chemical Corporation, CI Disperse Yellow 160), Oil Yellow 54 (trade name, manufactured by Chuo Synthetic Chemical Co., Ltd.) I. Disperse Yellow 54), Dial Resin Red H (trade name, manufactured by Mitsubishi Chemical Corporation, CI Disperse Red 5), Sumipla Thread B-2 (trade name, manufactured by Sumitomo Chemical Co., Ltd., CI Disper Thread 191), Kaya Set Red B (trade name, manufactured by Nippon Kayaku Co., Ltd., CI Disper Thread 60), Fillester Violet BA (trade name, manufactured by Ciba-Geigy, CI Disperse Violet 57), Plast Red 8335 (trade name, manufactured by Arimoto Chemical Co., Ltd., CI Disperse Violet 17), Plast Red 8375 (Product) Name, manufactured by Arimoto Chemical Industry Co., Ltd., CI Disperse Violet 60), Plast Blue 8516 (trade name, manufactured by Arimoto Chemical Industry Co., Ltd., CI Disperse Blue 14), and the like.

  Said disperse dye may be used individually by 1 type, or may use 2 or more types together.

  The disperse dye in the embodiment is preferably a sublimable dye. Here, the “sublimable dye” is a compound having a property of sublimation by heating. By using a sublimation dye, printing by sublimation transfer is possible in the textile printing field. In sublimation transfer printing, compared to direct printing, it is possible to reduce ink consumption, cleaning process, and environmental load, and to achieve high-efficiency and low-cost production. The molecular weight of the sublimable dye is preferably 350 or less in order to improve the sublimation property.

  Although it does not restrict | limit especially as a sublimation dye, The following examples are mentioned.

  Examples of yellow sublimable dyes include C.I. I. Disperse Yellow 3, 7, 8, 23, 39, 51, 54, 60, 71, 86 and the like.

  Examples of the orange sublimation dye include C.I. I. Disperse orange 1, 1: 1, 5, 20, 25: 1, 33, 56, 76 and the like.

  Examples of the brown sublimation dye include C.I. I. Disperse Brown 2 etc. are mentioned.

  Examples of the red sublimable dye include C.I. I. Disperse thread 11, 50, 53, 55: 1, 59, 60, 65, 70, 75, 93, 146, 158, 190, 190: 1, 207, 239, 240, C.I. I. Bad red 41 etc. are mentioned.

  Examples of the violet sublimable dye include C.I. I. Disperse violet 8, 17, 23, 27, 28, 29, 36, 57 etc. are mentioned.

  Examples of blue sublimation dyes include C.I. I. Disperse Blue 14, 19, 26, 26: 1, 35, 55, 56, 58, 64, 64: 1, 72, 72: 1, 81, 81: 1, 91, 95, 108, 131, 141, 145 , C.I. I. Solvent blue 36, 63, 105, 111 etc. are mentioned.

  Said sublimation dye may be used individually by 1 type, or may use 2 or more types together.

  Preferred sublimable dyes in this embodiment are, for example, C.I. I. Disperse yellow 54, 64, 160, C.I. I. Disperse thread 60, 91, 92, C.I. I. Solvent Violet 13, C.I. I. Disperse violet 28, C.I. I. Disperse Blue 359, C.I. I. Solvent blue 11, 36, 59, 63 etc. are mentioned. By using these sublimation dyes, a dyed product that is more excellent in sharpness and color developability and improved in light resistance and fastness can be obtained.

  Although the average particle diameter of the disperse dye mentioned above is not specifically limited, 30 nm-500 nm are preferable. More preferably, it is 50 nm-350 nm. When the average particle diameter is within the above range, color developability and ejection stability of ink from the inkjet head can be ensured. Here, the average particle diameter is a volume average particle diameter measured by a light scattering method, and can be measured using, for example, Microtrac UPA250 (manufactured by Nikkiso Co., Ltd.).

  The content of the color material contained in the ink of the present embodiment is 5% by mass or more and 30% by mass or less, and preferably 20% by mass or less, with respect to the total mass (100% by mass) of the ink. When the content of the coloring material is within the above range, dispersion inhibition and thickening due to excessive coloring material content are suppressed, and coloring of the dyed product is improved.

(Dispersant)
In the ultraviolet absorption spectrum corresponding to the molecular weight and the molecular weight of the dispersant measured by GPC (Gel Permeation Chromatography) method using an ultraviolet absorbance detector, the dispersant is x-axis; time (molecular weight), y-axis; UV Wavelength, z-axis: Contour lines drawn from right above the three-dimensional z-axis expressed in intensity (AU). When the y-axis value is max, the molecular weight (molecular weight at the maximum UV absorption wavelength) is Ba, and the y-axis value is UV absorption wavelength at maximum (UV absorption wavelength maximum value) is Bb, molecular weight when z-axis value is max (molecular weight at maximum UV absorption intensity) is Aa, UV absorption wavelength corresponding to Aa (maximum UV absorption intensity) When the UV absorption wavelength at the time is Ab, the expressions (1) and (2) are satisfied.
| Bb−Ab | ≧ 50 [nm] (1)
1000 ≦ | Ba−Aa | ≦ 30000 (2)

  Here, the measuring method of the dispersing agent by the GPC method and the analyzing method of the measuring data will be described with reference to an example of the measuring data of the dispersing agent of the present embodiment.

  First, the measuring method of the dispersing agent by GPC method is demonstrated. Dissolve the dispersant in a solvent to obtain a measurement sample. According to the GPC method, the dispersant can be separated according to the molecular weight. Specifically, when the measurement sample passes through the column of the GPC device, it is separated according to the molecular weight of the dispersant, and the dispersant component (molecule) having a relatively large molecular weight is fast and the dispersant component having a relatively small molecular weight. Is slow and reaches the outlet of the column. In this way, components having different molecular weights are separated by time difference. Therefore, it is possible to estimate the molecular weight of the separated dispersant component by comparing and calibrating using measurement data of a calibration standard sample (polymer compound) having a known molecular weight. In other words, there is a correlation between time and molecular weight.

  If a multi-wavelength UV (Ultraviolet) detector is used as a detector of the GPC measurement device, each ultraviolet absorption spectrum (hereinafter also referred to as “UV spectrum”) is obtained for the separated dispersant component. That is, it is possible to obtain a UV spectrum corresponding to the molecular weight of the dispersant, which is a polymer compound having a molecular weight distribution. Commercially available products can be applied to the solvent, GPC measurement device, detector, column, standard sample for calibration, and the like. Detailed measurement conditions will be described in Examples.

  Next, a method for analyzing measurement data obtained by the GPC method will be described. FIG. 1 is a three-dimensional graph showing measurement data of the dispersant according to the embodiment by the GPC method. 2 and 3 are two-dimensional graphs showing measurement data of the dispersant by the GPC method.

  FIG. 1 is a graph in which measurement data is displayed in three dimensions, with the x-axis being time (unit: minutes), the y-axis being UV wavelength (unit: nm), and the z-axis being intensity (UV absorption intensity). The x-axis time is the time when the dispersant component separated by the column reaches the detector, and indicates the so-called holding time. As described above, since time and molecular weight are correlated, the x-axis may be read as molecular weight. However, in that case, the direction of the molecular weight is opposite to the length of the time, and the longer the time, the smaller the molecular weight.

  For the dispersant component that has reached the detector, the detector measures the UV spectrum at regular intervals. That is, FIG. 1 is a graph showing the UV spectra of the dispersant component measured at regular intervals along the time axis. In FIG. 1, the UV spectra are not displayed individually but are displayed so that the curved surface formed by them can be recognized.

  As shown in FIG. 1, the largest peak is seen in the x-axis time between 15 and 22 minutes, with the vertices being relatively gentle. This is a peak derived from the dispersant component. On the other hand, a sharp peak on the low wavelength side of the peak is a peak derived from the solvent used for dissolving the dispersant. Except for components derived from components other than such a dispersant, the peak of the peak with the highest intensity is defined as a point P in the original peak of the dispersant component. Further, in the peak derived from the dispersant component, a point where the peak base (rise of the peak) is on the highest wavelength side is defined as a point Q. In the present invention, peaks derived from components other than the dispersant described above are excluded.

  FIG. 2 is a graph in which the data of FIG. 1 is displayed in two dimensions xy and the appearance range of main peaks is enlarged. In FIG. 2, the x-axis (horizontal axis) represents time, and the y-axis (vertical axis) represents UV wavelength. What is displayed in FIG. 2 connects points indicating the corresponding intensities of all absorption spectra in z-axis intensity from 0 to 0.25. In other words, FIG. 2 is a view of FIG. 1 (xyz three-dimensional graph) viewed from directly above the z-axis plus direction, and the level of strength is displayed as contour lines.

  As shown in FIG. 2, the point P is defined as (tA, Ab) in xy coordinates. That is, Ab is the UV absorption wavelength at the peak of the highest intensity peak (when the UV absorption intensity is maximum). Further, tA corresponding to Ab is the time when the peak having the highest intensity appears (when the z-axis value is max). tA is converted into the molecular weight Aa of the dispersant component corresponding to tA by a calibration method described later.

  Point Q is defined as (tB, Bb) in xy coordinates. That is, Bb is a point on the highest wavelength side (UV absorption wavelength when the y-axis value is max) on the contour line shown in FIG. Further, tB corresponding to Bb is a time when a peak having a base on the highest wavelength side appears. tB is converted into the molecular weight Ba of the dispersant component corresponding to tB by a calibration method described later.

  FIG. 3 is a graph in which the graph passing through the point P (Ab / wavelength: 297 nm) and the point Q (Bb / wavelength: 331 nm) in FIG.

  The dispersant preferably contains one or more aromatic rings in the molecular structure. Examples of such a dispersant include naphthalene sulfonic acid formalin condensate and styrene-maleic acid resin.

  One or more selected from the group consisting of aromatic sulfonate salt formalin condensate, lignin sulfonate salt, acrylic resin, styrene-acrylic resin, and styrene-maleic acid resin as a dispersant for enhancing the dispersibility of the disperse dye Are preferably used in combination.

  Although it does not specifically limit as a formalin condensate of an aromatic sulfonate, The following is mentioned as an example. Formalin condensate of naphthalene sulfonic acid, formalin condensate of creosote oil sulfonic acid, formalin condensate of cresol sulfonic acid, formalin condensate of phenol sulfonic acid, formalin condensate of β-naphthol sulfonic acid, formalin of methyl naphthalene sulfonic acid A condensate, a formalin condensate of alkyl naphthalene sulfonic acid such as a formalin condensate of butyl naphthalene sulfonic acid; a mixture of a formalin condensate of β-naphthalene sulfonic acid and a formalin condensate of β-naphthol sulfonic acid; A mixture of a formalin condensate and a formalin condensate of 2-naphthol-6-sulfonic acid, and the like.

  Although it does not specifically limit as a lignin sulfonate, Sodium lignin sulfonate etc. are mentioned.

  Known acrylic resins, styrene-acrylic resins, and styrene-maleic resins can be used.

  The molecular weight of the dispersant is preferably Aa ≦ 1000 and Ba ≦ 1000, more preferably Aa ≦ 2000 and Ba ≦ 2000, and further preferably Aa ≦ 3000 and Ba ≦ 3000 or more. On the other hand, the upper limit is preferably 100,000 or less, and more preferably 50,000 or less. If the molecular weight of the dispersant is small, the dispersion tends to become unstable, while if too high, the water solubility decreases and the dispersion does not proceed well.

  The above-described dispersant can take a wide range of solubility parameters, and is easily adapted to the solubility parameter of the color material, and the adsorption of the color material and the dispersant is easily stabilized. In addition, by having an aromatic ring in the molecular structure, the adsorption of the dispersing agent to the coloring material is more stabilized due to the interaction between the π electron of the aromatic ring in the coloring material and the π electron of the dispersing agent, and storage stability Improves.

  The content of the dispersant contained in the ink of the present embodiment is preferably 1% by mass or more and 20% by mass or less, and preferably 3% by mass or more and 15% by mass with respect to the total mass (100% by mass) of the ink. The following is more preferable. When the content is 1% by mass or more, the dispersion stability is improved, and when the content is 20% by mass or less, pulverization inhibition and thickening of the coloring material during dispersion can be suppressed.

(water)
In the present embodiment, water is included as the main dispersion medium of the ink described above. The water content in the ink of the present embodiment is preferably 40% by mass or more and 90% by mass or less, and more preferably 50% by mass or more and 80% by mass or less with respect to the total mass of the ink.

  The water is not particularly limited, and pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. In addition, by using water sterilized by ultraviolet irradiation or addition of hydrogen peroxide, generation of mold and bacteria can be suppressed when the colorant dispersion (or ink) is stored for a long period of time. In addition, the water can be easily removed after the ink is discharged as an ink by applying heat or air, so that the productivity of the dye is further improved.

[Ingredients other than coloring material, dispersant, water]
The ink according to the present embodiment may include components other than the color material dispersion. Examples of such components include water-soluble organic solvents, humectants, surfactants, antiseptic / antifungal agents, pH adjusters, chelating agents, rust preventives, ultraviolet absorbers, antifoaming agents, surface tension adjusting agents, and the like. Can be mentioned.

(Water-soluble organic solvent)
By including a water-soluble organic solvent, while effectively suppressing moisture evaporation from the ink jet head when left for a long period of time, wetting to the intermediate transfer medium is improved, ink permeability is improved, and ejection stability and Clogging recovery is also improved. Although it does not specifically limit as a water-soluble organic solvent, For example, a polyol compound, a glycol ether compound, etc. are mentioned.

  Examples of the polyol compound include a polyol compound (preferably a diol compound) having 2 to 6 carbon atoms in the molecule and having one ether bond in the molecule. Specific examples include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol. 2,3-butanediol, 3-methyl-1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1, Examples include 5-pentanediol, 1,2-hexanediol, and 1,6-hexanediol.

  Examples of glycol ethers include alkylene glycol monoether and alkylene glycol diether.

  Examples of the alkylene glycol monoether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl. Ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, Propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and the like.

  Examples of the alkylene glycol diether include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl methyl ether, triethylene glycol dimethyl ether, Triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol dibutyl methyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol Lumpur dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, and dipropylene glycol diethyl ether.

  The content ratio of the water-soluble organic solvent is preferably 1% by mass to 40% by mass, and more preferably 5% by mass to 30% by mass with respect to the total mass of the ink. When the content ratio of the water-soluble organic solvent is within the above range, it effectively suppresses water evaporation from the inkjet head of the printer when left for a long period of time, while improving wettability to the intermediate transfer medium and ink permeability. The discharge stability and clogging recovery performance are further improved.

(Humectant)
By including the humectant, the occurrence of clogging in the nozzles of the inkjet head can be reduced. Although it does not specifically limit as a humectant, For example, saccharides, a betaine compound, etc. are mentioned.

  Saccharides refer to monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), and polysaccharides. Examples of sugars include threose, erythrulose, erythrose, arabinose, ribulose, ribose, xylose, xylulose, lyxose, glucose, fructose, mannose, idose, sorbose, gulose, talose, tagatose, galactose, allose, psicose, altrose, maltose. Homoglycans such as isomaltose, cellobiose, lactose, sucrose, trehalose, isotrehalose, gentiobiose, melibiose, tulanose, sophorose, isosaccharose, glucan, fructan, mannan, xylan, galacturonan, mannuronan, N-acetylglucosamine polymer, Heteroglycans such as diheteroglycans and triheteroglycans, maltotriose, isomalttrio Scan, panose, maltotetraose, maltopentaose and the like, preferably, trehalose can be exemplified.

  A betaine compound is a compound that has a positive charge and a negative charge at non-adjacent positions in the same molecule, and a positively charged atom is not bonded to a dissociable hydrogen atom, and has no charge as a whole molecule. (Inner salt). Preferred betaine compounds are N-alkyl substituted amino acids, more preferably N-trialkyl substituted amino acids. Examples of the betaine compound include trimethylglycine (also referred to as “glycine betaine”), γ-butyrobetaine, homarine, trigonelline, carnitine, homoserine betaine, valine betaine, lysine betaine, ornithine betaine, alanine betaine, stachydrine and betaine glutamate. Preferably, trimethylglycine can be exemplified.

(Surfactant)
The surfactant is not particularly limited, but for example, at least one of acetylene glycol surfactants, fluorine surfactants, and silicone surfactants is preferable. When the ink contains the above-described surfactant, ink droplet formation (ejection stability) during ink ejection is further improved.

  Among these surfactants, a silicone-based surfactant that improves wettability in the ink flow path of the printer and further improves discharge characteristics is more preferable.

  The acetylene glycol surfactant is not particularly limited, and examples thereof include 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5- Selected from alkylene oxide adducts of decyne-4,7-diol and alkylene oxide adducts of 2,4-dimethyl-5-decyn-4-ol and 2,4-dimethyl-5-decyn-4-ol One or more are preferred.

  Although it does not specifically limit as a commercial item of an acetylene glycol type surfactant, For example, E series (A product made by Air Products Japan (INC.)), Surfynol 465, etc., such as Olfine 104 series and Olfine E1010, Surfynol 61 (Nissin Chemical Industry CO., Ltd.), etc. The acetylene glycol surfactant may be used alone or in combination of two or more. Also good.

  The fluorosurfactant is not particularly limited. For example, perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, perfluoroalkyl betaine, A fluoroalkylamine oxide compound etc. are mentioned.

  Although it does not specifically limit as a commercial item of a fluorochemical surfactant, For example, S-144, S-145 (Asahi Glass Co., Ltd. product); FC-170C, FC-430, Fluorard-FC4430 (Sumitomo 3M Co., Ltd. product) FSO, FSO-100, FSN, FSN-100, FS-300 (manufactured by Dupont); FT-250, 251 (manufactured by Neos Co., Ltd.) and the like.

  The above-mentioned fluorosurfactants may be used alone or in combination of two or more.

  Examples of silicone surfactants include polysiloxane compounds and polyether-modified organosiloxanes.

  Although it does not specifically limit as a commercial item of a silicone type surfactant, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-347, BYK-348, BYK- 349 (above trade name, manufactured by Big Chemie Japan Co., Ltd.), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (above trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be mentioned.

  The content ratio of the surfactant is preferably 0.1% by mass to 5% by mass, and more preferably 0.1% by mass to 3% by mass with respect to the total mass of the ink. When the content ratio of the surfactant is within the above range, the wettability of the ink attached to the dyed product tends to be further improved.

(Antiseptic and antifungal agent)
Examples of the antiseptic / antifungal agent include, but are not limited to, organic sulfur compounds, organic nitrogen sulfur compounds, organic halogen compounds, haloallyl sulfone compounds, iodopropargyl compounds, N-haloalkylthio compounds, benzoates, and the like. Thiazole compounds, nitrile compounds, pyridine compounds, 8-oxynoline compounds, isothiazoline compounds, dithiol compounds, pyridine oxide compounds, nitropropane compounds, organotin compounds, phenol compounds, quaternary ammonium salts Examples thereof include compounds, triazine compounds, thiadiazine compounds, anilide compounds, adamant compounds, dithiocarbamate compounds, brominated indanone compounds, benzyl bromacetate compounds, and inorganic salt compounds.

  Among the antiseptic / antifungal agents described above, it is preferable to use organic halogen compounds, pyridine oxide compounds, isothiazoline compounds, and the like.

  Although it does not specifically limit as an organic halogen type compound, For example, pentachlorophenol sodium etc. are mentioned.

  Although it does not specifically limit as a pyridine oxide type compound, For example, sodium pyridine thione-1-oxide, zinc pyridine thione-1-oxide, etc. are mentioned.

  The isothiazoline-based compound is not particularly limited, and examples thereof include 1-benzisothiazolin-3-one amine salt, 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-isothiazolin-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.

  Other antiseptic / antifungal agents include sodium dehydroacetate, sodium sorbate, sodium benzoate and the like.

(PH adjuster)
By including a pH adjuster, the storage stability of the ink tends to be more excellent. Although it does not specifically limit as a pH adjuster, For example, what can control the pH of an ink in the range of 6.0 or more and 11.0 or less can be used conveniently. Examples of such pH adjusters include, but are not limited to, alkanolamines such as diethanolamine, triethanolamine, dimethylethanolamine, and diethylethanolamine; lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium hydroxide, and the like. Alkali metal hydroxides; ammonium hydroxide; alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; aminosulfonic acid such as taurine; and the like.

(Chelating agent)
By including the chelating agent, it is possible to prevent the metal ions and dye eluted from the ink wetted part in the printer from becoming a salt and becoming a foreign substance. Thereby, clogging of the inkjet head can be prevented, and the ejection stability can be further improved. The chelating agent is not particularly limited, and examples thereof include disodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, and sodium uracil diacetate.

(Rust inhibitor)
Although it does not specifically limit as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropyl ammonium nitrite, pentaerythritol tetranitrate, dicyclohexyl ammonium nitrite, a benzotriazole type compound etc. are mentioned, for example.

(UV absorber)
The ultraviolet absorber is not particularly limited. For example, a benzophenone compound, a cinnamic acid compound, a triazine compound, a stilbene compound, a so-called fluorescent whitening agent (absorbing ultraviolet rays represented by benzoxazole compounds, And the like).

(Defoamer)
Although it does not specifically limit as an antifoamer, For example, a highly oxidized oil type compound, a glycerol fatty acid ester type compound, a fluorine-type compound, a silicone type compound, an acetylene type compound etc. are mentioned.

(Surface tension regulator)
Although it does not specifically limit as a surface tension regulator, For example, surfactant is mentioned.

  Although it does not specifically limit as surfactant, For example, anionic surfactant, an amphoteric surfactant, a cationic surfactant, a nonionic surfactant, etc. are mentioned.

  The anionic surfactant is not particularly limited, and examples thereof include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, and N-acylmethyl taurine. Salt, alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester salt, lauryl alcohol sulfate ester salt, alkylphenol type phosphate ester, alkyl type phosphate ester, alkyl Aryl sulfonates, diethylsulfosuccinates, diethylhexylsylsulfosuccinates, dioctylsulfosuccinates and the like can be mentioned.

  Examples of amphoteric surfactants include, but are not limited to, for example, lauryl dimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctyl Examples include polyaminoethylglycine and other imidazoline derivatives.

  Although it does not specifically limit as a cationic surfactant, For example, 2-vinyl pyridine derivative, a poly 4-vinyl pyridine derivative, etc. are mentioned.

  The nonionic surfactant is not particularly limited, and examples thereof include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Ether surfactants such as ethylene alkyl ether; polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate , Ester surfactants such as polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl Le 4-octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3-acetylene glycol surfactants, such as all the like.

[Ink properties]
(surface tension)
The surface tension (surface tension at 25 ° C.) of the ink is preferably 20 mN / m or more and 50 mN / m or less, more preferably 25 mN / m or more and 40 mN / m or less. The surface tension of the ink can be determined by measurement based on JIS K3362 using a surface tension meter CBVP-A3 (manufactured by Kyowa Interface Science Co., Ltd.). When the surface tension is within the above range, the ejection stability from the inkjet head tends to be excellent.

(viscosity)
The viscosity of the ink (viscosity at 25 ° C.) is preferably 2.0 mPa · s (millipascal second) to 20 mPa · s. When the viscosity is within the above range, the ejection stability of the ink from the inkjet tends to be more excellent. The ink viscosity can be determined by measurement based on JIS Z8809 using a vibration viscometer.

[Ink printing method]
Next, a method for printing a dyed product using the ink according to the present embodiment will be described. The textile printing method includes, for example, an ink application process in which ink is applied to an intermediate transfer medium by an inkjet method using a printer, and the intermediate transfer medium to which the ink has been applied is heated, and the sublimation dye contained in the ink is dyed on the medium to be dyed And a transfer step for transferring to the substrate. Thereby, a dyeing | staining thing can be printed with sufficient productivity. Hereinafter, each step will be described in detail.

(Ink application process)
In the ink application process, ink is applied to the intermediate transfer medium by an inkjet method. Specifically, the ink is ejected as fine droplets onto the intermediate transfer medium to land (apply). In conventional inks, it is difficult to ensure sufficient storage stability, and particles of the color material (dispersed dye) may aggregate to cause ejection instability in the ejection. In the ink of the present embodiment, since storage stability is improved, aggregation of color materials is suppressed, and ejection stability is improved. Here, the ink ejection by the ink jet method can be performed using a known ink jet recording apparatus. As a discharging method, a piezo method, a method of discharging ink by bubbles generated by heating the ink, or the like can be used. Among these, the piezo method is preferable from the viewpoint of difficulty in changing the quality of the ink.

  In the ink application process, an ink other than the above ink may be used. Thereby, for example, the color gamut that can be expressed can be made wider.

  The intermediate transfer medium is not particularly limited. For example, in addition to plain paper, a medium to be dyed provided with an ink receiving layer (referred to as inkjet paper or coated paper) can be used. Among these, paper in which an ink receiving layer is provided with inorganic fine particles such as silica is preferable. Thereby, in the process of drying the ink applied to the intermediate transfer medium, an intermediate transfer medium in which bleeding or the like is suppressed can be obtained, and in the subsequent transfer step, sublimation of the sublimable dye proceeds more smoothly. There is a tendency.

(Transfer process)
Thereafter, the intermediate transfer medium to which the ink has been applied is heated to transfer the sublimable dye contained in the ink to the medium to be dyed. Thereby, a dyeing | staining thing is obtained.

  The heating temperature (heating temperature) in this step is preferably 160 ° C. or higher and 220 ° C. or lower, and more preferably 170 ° C. or higher and 220 ° C. or lower. When the heating temperature is within the above range, the energy required for transfer can be reduced, and the productivity of dyed products tends to be superior. Further, the coloring property of the obtained dyed product tends to be more excellent.

  Although the heating time (heating temperature) in this step depends on the heating temperature, it is preferably 30 seconds or longer and 90 seconds or shorter, and more preferably 45 seconds or longer and 60 seconds or shorter. When the heating time is within the above range, the energy required for transfer can be reduced, and the productivity of dyed products tends to be superior. Further, the coloring property of the obtained dyed product tends to be more excellent.

  In addition, this step can be performed by heating the surface of the intermediate transfer medium to which ink has been applied in a state of being opposed to the medium to be dyed at a predetermined interval. It can also be performed by heating in a close contact state. Among these, it is preferable to perform the heating by heating the intermediate transfer medium and the medium to be dyed in close contact with each other. As a result, the energy required for transfer can be reduced and the dyeing product tends to be more productive. Further, the coloring property of the obtained dyed product tends to be more excellent.

  Although it does not specifically limit as a to-be-dyed medium, The following is mentioned as an example. Fabric (hydrophobic fiber fabric, etc.), resin (plastic) film, paper, glass, metal, ceramics, etc. Further, as the medium to be dyed, a medium having a three-dimensional shape such as a sheet shape, a spherical shape or a rectangular parallelepiped shape may be used.

  In the case where the medium to be dyed is a fabric, the fibers constituting the fabric are not particularly limited, but examples thereof include the following. Polyester fibers, nylon fibers, triacetate fibers, diacetate fibers, polyamide fibers and blended products using two or more of these fibers. Moreover, you may use the blended products of these and regenerated fibers, such as rayon, or natural fibers, such as cotton, silk, and wool. Examples of the fabric include fabrics such as woven fabrics, knitted fabrics, and nonwoven fabrics processed from the above fibers. Examples of the form of the fabric include clothing and other clothing items, long items wound in a roll shape, those cut into a predetermined size, and those in a product shape.

  Moreover, when the medium to be dyed is a resin (plastic) film, the resin (plastic) film that can be used is not particularly limited, but examples thereof include the following. Polyester film, polyurethane film, polycarbonate film, polyphenylene sulfide film, polyimide film, polyamideimide film, etc. The resin (plastic) film may be a laminate in which a plurality of layers are laminated, or may be composed of a gradient material in which the composition of the material changes in a gradient manner.

(Other processes)
In addition to the steps as described above, there may be other steps (a pretreatment step, an intermediate treatment step, a post treatment step).

  Although it does not specifically limit as a pre-processing process, For example, the process of apply | coating a coat layer to a to-be-dyed medium is mentioned.

  Although it does not specifically limit as an intermediate process process, For example, the process of preheating a to-be-dyed medium is mentioned.

  Although it does not specifically limit as a post-processing process, For example, the process of wash | cleaning a to-be-dyed medium is mentioned.

  In addition, the ink according to the present embodiment can be suitably used in sublimation transfer without using an intermediate transfer medium. Sublimation transfer without using an intermediate transfer medium is not particularly limited, and examples thereof include the following methods. A step of applying the ink according to the present embodiment to the ink receiving layer of a dyed medium (film product or the like) provided with a peelable ink receiving layer by an inkjet method, and an ink receiving layer to which the ink is applied are provided. The method includes the steps of heating the dyed medium as it is, sublimation diffusion dyeing from the ink receiving layer to the dyed medium on the lower layer side, and separating the ink receiving layer from the dyed medium to obtain a dyed product Etc.

[Dyeing]
Next, the dyed material obtained with the ink according to the present embodiment will be described. The dyed material is dyed using the ink according to the present embodiment as described above. Thereby, it is possible to provide a dyed product having excellent color developability.

  Next, specific embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The main materials for the ink compositions used in the following examples and comparative examples are as follows.
[Color material]
DR60 (CI Disperse Red 60)
DY54 (CI Disperse Yellow 54)
[Surfactant]
BYK-348 (silicone surfactant, manufactured by Big Chemie Japan)
[Dispersant]
D-MS (Special aromatic sulfonic acid formalin condensate, manufactured by Kao Corporation)
D-SNB (Naphthalenesulfonic acid butyl naphthalenesulfonic acid formalin condensate sodium salt, manufactured by Kao Corporation)
RW-40 (creosote oil sulfonate sodium formalin condensate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
R-AN40 (Sodium formalin condensate of methyl naphthalene sulfonate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
R-FD40 (Naphthalenesulfonic acid sodium formalin condensate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
S-120 (Naphthalene sulfonate sodium formalin condensate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
The type of each dispersant used, measured values (Aa, Ab, Ba, Bb) measured by the GPC method described later, and Δabsorbance (| Bb-Ab |) and Δmolecular weight | Ba calculated using the measured values -Aa | is shown in Table 1.

[Water-soluble organic solvent]
Glycerin [Water]
Pure water

[Preparation of ink]
Each material was mixed with the composition (mass%) shown in Table 2 below to obtain each ink. In Table 2, a blank means no addition.

  Moreover, the measuring method of GPC of each dispersing agent in an Example and a comparative example is as follows.

[GPC measurement of dispersant]
Monodispersed polystyrene (manufactured by Tosoh Corporation) was used as a standard sample. Weighed as shown in Table 3, with 3 levels as 1 group, and diluted by adding 2 ml mobile phase per group. Next, GPC measurement was performed under the following measurement conditions. A calibration curve of time (retention time) and molecular weight was created using data obtained from an RI detector described later. At this time, since a UV detector is used for measurement of the dispersing agent, a calibration curve for the UV detector is formed by taking into account the detection time difference (0.3 minutes) between the RI detector and the UV detector arranged in tandem. Note that data of a standard sample may be acquired using a UV detector, and a calibration curve may be directly obtained from this data. In this case, the RI detector is not always necessary. Then, GPC measurement of the dispersant 1 to the dispersant 8 was performed, and the numerical values shown in Table 1 were obtained.

[Device measurement conditions]
Measuring device: Emperor GPC manufactured by waters
Detector: tandem arrangement of differential refractive index detector (RI detector) and 2996 photodiode array detector (UV detector) manufactured by waters (column side is RI detector)
Column: 1 each for TSKgel α-M, α-3000 (φ7.8 mm × 30 cm, Tosoh)
Mobile phase (solvent, etc.): 0.05M lithium chloride and 0.01% concentrated hydrochloric acid-added dimethylformamide (DMF)
Flow rate: 0.8mL / min
Injection volume: 20 μl

[Storage stability]
The ink obtained above was accommodated in a glass bottle and sealed, and allowed to stand in a 60 ° C. environment for 24 hours. The particle size before and after the thermal history was measured by the dynamic light scattering method.

The measured particle size was evaluated according to the following criteria. The results are shown in Table 2 as storage stability.
A: D50 and D90 are both after heating / before heating <1.5
B: Either D50 or D90, 1.5 ≦ after heating / before heating ≦ 2
C: Either D50 or D90 is 2 <After heating / Before heating (If D50 or D90 is B and the other is C, C is determined)

[Discharge stability]
A part of the printer Stylus Pro 9900 (manufactured by Seiko Epson Corporation) was remodeled and evaluated as a printer capable of heating and controlling the recording medium after ink jet recording. After 10 hours of continuous discharge, discharge stability was evaluated as follows. In addition, maintenance was performed every time recording was performed for 2 hours.

The discharge stability was evaluated according to the following criteria. The results are shown in Table 2.
A: Slight non-ejection or ejection disturbance occurs during ejection, but it returns during ejection and there is almost no problem B: Non-ejection or ejection disturbance occurs during ejection and does not return during ejection, but maintenance State that returns to normal state due to C: State that non-discharge or discharge disorder occurs slightly during discharge, does not return during discharge, and does not return due to maintenance

  From the results in Table 2, it was found that the inks of Examples 1 to 8 using the dispersant satisfying the formulas (1) and (2) were excellent in storage stability and ejection stability. On the other hand, it was found that the inks of Comparative Examples 1 to 8 using a dispersant that did not satisfy the formulas (1) and (2) were inferior in storage stability and ejection stability.

Claims (7)

An inkjet ink containing a colorant, a dispersant, and water,
In the ultraviolet absorption spectrum corresponding to the molecular weight and the molecular weight of the dispersant measured by GPC (Gel Permeation Chromatography) method using an ultraviolet absorbance detector, the dispersant is x-axis; time (molecular weight), y The molecular weight when the y-axis value is max (the molecular weight at the maximum UV absorption wavelength) in the three-dimensional contour line drawn from right above the z-axis expressed by the axis; UV wavelength, z-axis: intensity (AU) is Ba , The UV absorption wavelength (maximum UV absorption wavelength) when the y-axis value is max corresponds to Bb, the molecular weight when the z-axis value is max (molecular weight at the maximum UV absorption intensity) corresponds to Aa, and Aa. An inkjet ink that satisfies the expressions (1) and (2), where Ab is the UV absorption wavelength (the UV absorption wavelength at the maximum UV absorption intensity).
| Bb−Ab | ≧ 50 [nm] (1)
1000 ≦ | Ba−Aa | ≦ 30000 (2)   The inkjet ink according to claim 1, wherein both the molecular weight Aa and the molecular weight Ba are 1000 or more.   The inkjet ink according to claim 1, wherein the dispersant contains one or more aromatic rings in a molecular structure.   2. The dispersant is one or more selected from the group consisting of a formalin condensate of an aromatic sulfonate, or a lignin sulfonate, an acrylic resin, a styrene-acrylic resin, and a styrene-maleic resin. The inkjet ink according to claim 3.   The ink-jet ink according to any one of claims 1 to 4, wherein the coloring material is water-insoluble or hardly water-soluble.   The inkjet ink according to any one of claims 1 to 5, wherein the coloring material is a disperse dye.   A dyed product dyed with an ink-jet ink containing the disperse dye according to claim 6.

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