Ink container and recording method

Abstract

The invention relates to an ink container and a recording method, and provides an ink container containing an inkjet ink composition with excellent ejection stability. The ink container has: an ink jet ink composition which is an aqueous ink containing a pigment and a surfactant, the pigment including at least two kinds of pigments having different types of chemical structures, and a container for containing the ink jet ink composition; the surfactant contains a polysiloxane-based surfactant having an HLB value of 10 or more and an alkynediol-based surfactant having an HLB value of 6-10 (inclusive), and the amount of dissolved nitrogen contained in the inkjet ink composition is 5 ppm or more.

Description

Technical Field

[0001] The present invention relates to an ink container and a recording method. Background Art

[0002] The inkjet recording method can record high-definition images with a relatively simple device, and has been rapidly developed in various fields. Among them, various studies have been proposed to improve the color reproducibility of water-based inks. For example, Patent Document 1 discloses an ink cartridge using an ink composition mixed with two or more pigments for the purpose of obtaining a desired hue.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2007-297596

[0004] However, when recording is performed using an ink composition that includes two or more pigments of different chemical structures, such as the ink composition described in Patent Document 1, there may be a technical problem that ejection stability may deteriorate due to the type of container of the ink container, the handling of the ink container containing the ink composition, and the like. Summary of the invention

[0005] The ink container of the present invention is an ink container having an inkjet ink composition and a container for accommodating the inkjet ink composition, wherein the inkjet ink composition is an aqueous ink containing a pigment and a surfactant, wherein the pigment comprises at least two pigments of different chemical structures, wherein the surfactant comprises a polysiloxane-based surfactant having an HLB value of 10 or more and an acetylene glycol-based surfactant having an HLB value of 6 or more and 10 or less, and wherein the amount of dissolved nitrogen in the inkjet ink composition accommodated is 5 ppm or more.

[0006] The recording method of the present invention includes an attaching step of ejecting the inkjet ink composition supplied from the above-mentioned ink container from an inkjet head and attaching the inkjet ink composition to a recording medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 Table 1 shows the conditions and evaluation results of Examples.

[0008] Figure 2 Table 2 shows the conditions and evaluation results of Examples.

[0009] Figure 3 Table 3 shows the conditions and evaluation results of Examples.

[0010] Figure 4 Table 4 shows the conditions and evaluation results of Examples.

[0011] Figure 5 Table 5 shows the conditions and evaluation results of Examples.

[0012] Figure 6 This is a diagram showing an ink pack as an example of the container according to the present embodiment.

[0013] Figure 7 This is a diagram showing an ink bottle as an example of the container according to the present embodiment.

[0014] Figure 8 This is a diagram showing an example of a recording device used in the recording method of this embodiment.

[0015] Description of Reference Numerals

[0016] 10: ink cartridge; 40: ink pack; 42: ink cartridge case; 44: ink supply port; 46: main body case; 48: cover portion. 63: ink bottle; 64: container main body; 65: ink outlet; 66: ink outlet forming portion; 67: container attachment portion; 69: external thread portion; 70: protrusion; 71: convex portion (fitting portion); 72: second concave-convex portion; 74: valve; 76: ink containing chamber; 77: neck portion; 78: external thread portion; 79: large diameter portion; 80: small diameter portion; 81: intermediate portion; 82: internal thread portion; 83: joint portion; IK: ink composition. 1: inkjet recording device; 12: paper feed port; 13: support portion; 14: paper discharge port; 16: bracket; 17: inkjet head; 20 (20Bk, 20Cn, 20Ma, 20Yw): sub-tank; 24: ink supply tube (ink supply path); 50: ink tank; 54 (51): ink injection port; X: X-axis; Y: Y-axis; Z: Z-axis. DETAILED DESCRIPTION

[0017] Hereinafter, the embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail with reference to the accompanying drawings as needed, but the present invention is not limited thereto and may be variously modified within the scope of the main purpose thereof. It should be noted that in the accompanying drawings, the same symbols are used for the same elements and repeated descriptions are omitted. In addition, the positional relationship such as up, down, left, and right is based on the positional relationship shown in the accompanying drawings when no special limitation is made. Moreover, the dimensional ratios of the accompanying drawings are not limited to the ratios shown in the drawings.

[0018] 1. Ink container

[0019] The ink container involved in this embodiment is an ink container having an inkjet ink composition (hereinafter also referred to as "ink composition") and a container for containing the above-mentioned inkjet ink composition, the above-mentioned inkjet ink composition is an aqueous ink containing a pigment and a surfactant, the above-mentioned pigment includes at least two pigments of different chemical structures, the above-mentioned surfactant includes a polysiloxane-based surfactant with an HLB value of 10 or more and an acetylene glycol-based surfactant with an HLB value of 6 or more and 10 or less, and the amount of dissolved nitrogen in the above-mentioned inkjet ink composition contained is 5 ppm or more.

[0020] When pigments are used to prepare pigment dispersions and ink compositions, tiny bubbles may remain on the surface of the pigment particles. Such tiny bubbles grow, and the grown bubbles detach from the pigment and escape into the ink composition, thus generating bubbles in the ink composition, which may cause poor ejection. In addition, the growth of tiny bubbles is promoted by gas components such as dissolved nitrogen dissolved in the ink. Therefore, according to the hydrophilicity and hydrophobicity, concavity and smoothness of the pigment used, the following operation is performed: by adjusting the type and amount of surfactants and organic solvents, the wettability of the pigment surface is improved without leaving tiny bubbles.

[0021] However, in order to obtain a desired color for a water-based ink, multiple pigments are sometimes used. Pigments with different chemical structures may have different hydrophilicity and hydrophobicity or different concavity and smoothness of the plane due to their chemical structures. Therefore, it is difficult to simply determine the ink composition for improving the wettability of the pigment surface without leaving fine bubbles. It can be seen from this that it is difficult to improve the ejection stability of water-based inks containing two or more pigments with different chemical structures.

[0022] In this regard, it is also conceivable to use a container with high gas barrier properties to prevent the concentration of gas components dissolved in the ink from increasing, thereby inhibiting the growth of fine bubbles. However, even if such a container is used, it is difficult to prevent the dissolution of air due to the handling of the ink composition.

[0023] Therefore, in this embodiment, by including a polysiloxane surfactant with a high HLB value and an acetylene glycol surfactant with a low HLB value, the wettability of the pigment surface is improved, so that the surface of the pigment does not adsorb fine bubbles, and the reduction in ejection stability caused by the growth of fine bubbles is prevented, and an ink composition with excellent ejection stability can be provided even when the amount of dissolved nitrogen in the ink composition is 5 ppm or more. However, the main reason is not limited to the above. The structure of the ink container is described in detail below.

[0024] 1.1. Inkjet ink composition

[0025] The inkjet ink composition according to the present embodiment is a water-based ink containing a pigment and a surfactant, wherein the pigment includes at least two pigments of different chemical structures, and the surfactant includes a polysiloxane-based surfactant having an HLB value of 10 or more and an acetylene glycol-based surfactant having an HLB value of 6 or more and 10 or less. By setting the ink composition to have the above composition, the ejection stability of the ink container is excellent.

[0026] 1.1.1. Pigments

[0027] The ink composition contains at least two pigments of different chemical structure classifications. Here, in this specification, different chemical structure classifications refer to the situation where the substances having a common chemical structure such as functional groups are classified by a person skilled in the art, and as a result, they may belong to different chemical structure classifications. Specifically, pigments classified as azo compounds, quinacridone compounds, dioxazine compounds, pyrenone compounds, perylene compounds, diketopyrrolopyrrole compounds, isoindolinone compounds and reducing compounds are respectively equivalent to pigments of different chemical structure classifications. In order to form a combination of azo compounds and quinacridone compounds, the ink of this embodiment contains at least two selected from the group consisting of pigments belonging to these classifications. On the other hand, in the case of containing two azo compounds with different structures as pigments, it does not become "containing at least two pigments of different chemical structure classifications" in this embodiment. By containing these pigments, ejection defects caused by bubbles may occur in particular, and the effect of the present invention tends to become significant. It should be noted that as pigments, only two or more types can be used.

[0028] In this embodiment, it is preferred that the second pigment compound contains a first pigment compound which is an azo compound and at least one selected from the group consisting of quinacridone compounds, dioxazine compounds, pyrenone compounds, perylene compounds and diketopyrrolopyrrole compounds.

[0029] In this case, since the range of the hue angle that can be recorded is wide, it is preferred. On the other hand, there is the following trend: the planarity of the pigment particles of the first pigment compound is high, and the planarity of the pigment particles of the second pigment compound is low. Therefore, by including such a compound as a pigment, the two pigment differences are larger, and therefore it is particularly easy to produce the poor ejection caused by the bubble, and the effect based on the present invention has a significant trend. In addition, the storage stability also has a trend of further improvement.

[0030] From the same viewpoint, it is more preferred to contain at least one of a pyrenone compound and a quinacridone compound as the second pigment compound.

[0031] Inclusion of the first pigment compound which is an azo compound is preferred because of excellent color development.

[0032] It is preferred that a pyrenone compound is contained as the second pigment compound because the discharge stability is more excellent.

[0033] According to the present embodiment, even when a quinacridone compound is included as the second pigment compound, discharge stability, storage stability, etc. can be obtained, which is useful.

[0034] In the present embodiment, the hue of the ink composition is preferably yellow-red. The yellow-red color is mainly used when recording warm colors such as yellow ink, orange ink, magenta ink, and red ink.

[0035] For example, through CIEL ＊ a ＊ b ＊ When measuring the color of a recorded object in which each ink is attached to a recording medium, the ink has a hue angle of the recorded object between the hue angle of the yellow ink and the hue angle of the recorded object based on the magenta ink (including the interval of 0°). The recorded object in the color measurement is made such that the surface of the part of the white recording medium to be measured is completely covered with ink. It is also called an ink between the yellow ink and the magenta ink in the hue angle.

[0036] Warm colors require recording of various colors, and sometimes it is difficult to prepare the desired color with only one pigment. Therefore, multiple pigments are often used. In addition, in the combination of pigments constituting such yellow-red inks, it is particularly easy to produce poor ejection caused by bubbles, and the effect of the present invention tends to become more significant. In addition, the storage stability also tends to be further improved.

[0037] Among them, inks other than yellow ink in the yellow-red series are particularly preferred, namely, yellow-red inks such as orange ink, magenta ink, and red ink. In particular, these can also be referred to as red inks.

[0038] In addition, it is also preferable to use special color inks in the yellow-red series. The yellow-red series as special color inks is inks other than the yellow ink and magenta ink as basic colors in the yellow-red series. On the other hand, it is also preferable to use basic color inks in the yellow-red series. The basic color inks in the yellow-red series are yellow ink and magenta ink.

[0039] When these inks are used, the effects of the present invention become more remarkable, and therefore, it is preferred.

[0040] The content of the first pigment compound, which is an azo compound, is preferably 0.1% by mass to 5.0% by mass, 0.5% by mass to 4.0% by mass, or 0.7% by mass to 3.0% by mass, relative to the total amount of the ink composition. Furthermore, it is preferably 1.0% by mass to 2.0% by mass.

[0041] When the content of the first pigment compound is within the above range, there is a tendency that the discharge stability and the storage stability can be further reliably improved.

[0042] The content of the second pigment compound is preferably 0.5% by mass to 5.0% by mass, 1.0% by mass to 4.0% by mass, and more preferably 2.0% by mass to 3.5% by mass, relative to the total amount of the ink composition.

[0043] When the content of the second pigment compound is within the above range, there is a tendency that the discharge stability and the storage stability can be further reliably improved.

[0044] Examples of azo compounds (azo pigments) include CI Pigment Yellow 1, 3, 4, 6, 12, 14, 17, 55, 62, 65, 73, 74, 81, 83, 95, 97, 104, 117, 120, 128, 129, 150, 151, 154, 155, 167, 174, 180, 185, and 213. As a pigment used in yellow ink, CI Pigment Red As pigments used in magenta ink, CI Pigment Orange (Pigment Orange) 1, 5, 13, 16, 34, 36, 60, 61, 62, 64, 67, 72 are used as pigments for orange ink. From the viewpoint of more effectively and reliably exerting the effects of the present invention, it is preferable to use PR150 and / or PR242.

[0045] It should be noted that the above pigment is preferably a yellow-red ink, and the ink used is not limited to the above, which is an example. The same applies to the pigments described below.

[0046] The content of the azo compound is preferably 0.1% by mass to 5.0% by mass, 0.5% by mass to 4.0% by mass, or 1.0% by mass to 3.0% by mass relative to the total amount of the ink composition. By setting the content of the azo compound within the above range, there is a tendency to further reliably improve the ejection stability and storage stability.

[0047] Examples of quinacridone compounds (quinacridone pigments) include CI Pigment Red 122, 202, 206, 207, and 209, CI Pigment Violet 19, and CI Pigment Orange 48 and 49. From the viewpoint of more effectively and reliably exhibiting the effects of the present invention, PR122 is preferably used.

[0048] The content of the quinacridone compound is preferably 0.1% by mass to 5.0% by mass, and 0.5% by mass to 3.0% by mass, relative to the total amount of the ink composition. By setting the content of the quinacridone compound within the above range, there is a tendency to further reliably improve the ejection stability and storage stability.

[0049] Examples of the pyrenone-based compound (pyrenone-based pigment) include pyrenone orange 43. From the viewpoint of more effectively and reliably exhibiting the effects of the present invention, it is preferred to use PO43.

[0050] The content of the pyrone compound is preferably 1.0 mass % to 5.0 mass % and 2.0 mass % to 4.0 mass % relative to the total amount of the ink composition. By making the content of the pyrone compound within the above range, there is a tendency to further reliably improve the ejection stability.

[0051] Examples of the dioxazine compound (dioxazine pigment) include CI Pigment Blue 80 and CI Pigment Violet 23 and 37.

[0052] As a perylene type compound (perylene type pigment), CI Pigment Red (Pigment Red) 123, 149, 178 are mentioned, for example.

[0053] Examples of the diketopyrrolopyrrole compound (diketopyrrolopyrrole pigment) include CI Pigment Red 254, 255, 164, 270, 272, and 283.

[0054] The total content of the pigments in the ink composition is preferably 0.5% by mass or more and 10% by mass or less, 1.0% by mass or more and 8.0% by mass or less, or 3.0% by mass or more and 5.0% by mass or less relative to the total amount of the ink composition. By setting the total content of the pigments within the above range, there is a tendency to further reliably improve the ejection stability and storage stability.

[0055] The pigment is preferably able to be stably dispersed in the dispersion medium, and for this purpose, a dispersant can be used to disperse it. Examples of the dispersant include surfactants, dispersant resins as resins, and the like. The dispersant is selected from substances that can provide good dispersion stability of the pigment in the ink composition. Examples of the dispersant resin include acrylic resins, polyurethane resins, maleic acid resins, and the like. The acrylic resin is a resin obtained by polymerizing at least an acrylic monomer, and may also be a copolymer of an acrylic monomer and other monomers.

[0056] Pigments dispersed with resin are also referred to as resin-dispersed pigments. Resin-dispersed pigments are pigments dispersed with resin. The dispersant resin may be a water-soluble resin, a water-insoluble resin, or the like. In addition, the pigment may be used as a self-dispersible pigment by, for example, oxidizing the surface of the pigment with ozone, hypochlorous acid, fuming sulfuric acid, or by modifying the surface of the pigment particles by introducing a hydrophilic functional group. Examples of the hydrophilic functional group introduced include a carboxyl group, a sulfonic group, a phosphorus-containing group, and the like.

[0057] 1.1.2. Surfactants

[0058] The ink composition contains at least a polysiloxane surfactant having an HLB value of 10 or more (hereinafter referred to as a "polysiloxane surfactant") and an acetylene glycol surfactant having an HLB value of 6 or more and 10 or less (hereinafter referred to as a "acetylene glycol surfactant"). By including these surfactants in the ink composition, the ink container has excellent ejection stability. It should be noted that the surfactants may be used in the form of only two or more than three.

[0059] In this specification, the HLB (Hydrophile-Lipophile Balance) value of a surfactant is a value for evaluating the hydrophilicity of a compound advocated by Davis et al., for example, a value obtained by the Davis method defined in the document "JT. Davies and E.K. Rideal, 'Interface Phenomena' 2nd ed. Academic Press, New York 1963", and represents a value calculated by the following formula (i).

[0060] HLB value=7+Σ[1]-Σ[2]···(i)

[0061] (In formula (i), [1] represents the number of hydrophilic groups, and [2] represents the number of hydrophobic groups.)

[0062] Examples of commercially available polysiloxane compounds include BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (all trade names, manufactured by BYK 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 (all trade names, manufactured by BYK 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 (all trade names, manufactured by BYK Japan Co., Ltd.), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945 Trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), FZ-2104 Fluid, FZ-2105, FZ-2110, FZ-2123, FZ-2164, FZ-2191, FZ-5609 Fluid, L-7001, L-7002, L-7604, OFX-0309 Fluid, OFX-5211 Fluid, SF8410 Fluid, OFX-0193 Fluid, SH-3746 Fluid, SH-3771 Fluid, SH-8400 Fluid, SH-8700 Fluid, Y-7006 (all manufactured by Toray Dowcorning Co., Ltd.).

[0063] However, the above-mentioned substance having an HLB value of 10 or more is used. The HLB value may be obtained by the above-mentioned Davis method.

[0064] From the viewpoint of more effectively and reliably exhibiting the effects of the present invention, it is preferred to use at least one of the above-mentioned KF-640 and FZ-2105.

[0065] The content A of the polysiloxane surfactant is preferably 0.1% by mass or more and 5.0% by mass or less, 0.2% by mass or more and 2.0% by mass or less, or 0.3% by mass or more and 1.5% by mass or less, relative to the total amount of the ink composition. By setting the content of the polysiloxane surfactant within the above range, there is a tendency that the ejection stability can be further reliably improved.

[0066] Examples of the acetylene glycol surfactant include SURFYNOL 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, DF110D (all trade names, manufactured by Air-Products & Chemicals), OLEFIN B, Y, P, A, STG, SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP.4001, EXP.4036, EXP.4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all the above trade names, manufactured by Nissin Chemical Industry Co., Ltd.), ACETYLENOL E00, E00P, E40, E100 (all the above trade names, manufactured by Kawakami Fine Chemical Co., Ltd.).

[0067] However, the above-mentioned substances have an HLB value of 6 to 10. The HLB value may be obtained by the above-mentioned Davis method.

[0068] From the viewpoint of more effectively and reliably exhibiting the effects of the present invention, it is preferred to use at least one of SURFYNOL 440 and SURFYNOL SE.

[0069] The content B of the acetylene glycol surfactant is preferably 0.05% by mass or more and 3.0% by mass or less, and 0.1% by mass or more and 1.0% by mass or less, relative to the total amount of the ink composition. By making the content of the acetylene glycol surfactant within the above range, there is a tendency to further reliably improve the ejection stability.

[0070] The mass ratio (A / B) of the content A of the polysiloxane surfactant to the content B of the acetylene glycol surfactant is 0.3 or more and 8.0 or less, preferably 0.5 or more and 7.5 or less. Further, it is preferably 1.2 or more and 4.0 or less, more preferably 1.5 or more and 3.0 or less, and particularly preferably 2.0 or more and 2.8 or less. By making A / B within the above range, there is a tendency that the ejection stability and storage stability can be further reliably improved.

[0071] In addition, the ink composition of this embodiment may contain other surfactants such as fluorine-based surfactants in addition to polysiloxane-based surfactants and acetylene glycol-based surfactants. Examples of such fluorine-based surfactants include BYK-3440 (manufactured by BYK Japan), SURFLON S-241, S-242, S-243 (the above trade names, manufactured by AGC SemiChemical), and FTERGENT 215M (manufactured by NEOS). In addition, polysiloxane-based surfactants and acetylene glycol-based surfactants having HLB values ​​outside the above range may be contained.

[0072] The total content of the surfactant is preferably 0.1% by mass or more and 5.0% by mass or less, 0.3% by mass or more and 3.0% by mass or less, or 0.4% by mass or more and 2.0% by mass or less relative to the total amount of the ink composition. By making the total content of the surfactant within the above range, there is a tendency to further reliably improve the ejection stability.

[0073] 1.1.3. Organic solvents

[0074] The ink composition of this embodiment may contain an organic solvent. By containing an organic solvent, there is a tendency that the ejection stability of the ink composition can be maintained while suppressing the evaporation of water from the recording head when the ink composition is left for a long period of time. It should be noted that as an organic solvent, one kind may be used alone, or two or more kinds may be used in combination.

[0075] In particular, the ink composition preferably contains an SP value of 9 (cal / cm 3 ) 1 / 2 Above and 13.5 (cal / cm 3 ) 1 / 2 The following organic solvents. By making the SP value of the organic solvent used within the above range, there is a tendency to further reliably improve the ejection stability and storage stability. It should be noted that the ink composition of this embodiment may also contain an SP value other than 9 (cal / cm 3 ) 1 / 2 Above and 13.5 (cal / cm 3 ) 1 / 2 The following organic solvents.

[0076] As the SP value in this specification, the Hansen solubility parameter is used. The Hansen solubility parameter divides the solubility parameter introduced by Hildebrand into three components: dispersion term δd, polar term δp, and hydrogen bonding term δh and expresses them in three-dimensional space. However, in the present invention, the SP value is expressed as δ[(cal / cm 3 )0.5 ] and the value calculated using the following formula is used.

[0077] δ[(cal / cm 3 ) 0.5 ]=(δd 2 +δp 2 +δh 2 ) 0.5

[0078] As the organic solvent, a water-soluble organic solvent is preferred, and examples of such a solvent include polyols, glycol ethers, lactams, alcohols, and the like.

[0079] Examples of the polyols include hydrocarbons having two or more hydroxyl groups in the molecule, triols or higher polyols having three or more hydroxyl groups in the molecule, and diols.

[0080] Examples of the glycol ethers include glycol monoethers and glycol diethers.

[0081] For example, propylene glycol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,3-butanediol, 1,5-pentanediol, and 1,6-hexanediol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, diethylene glycol monoethyl ether, Propylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether and other glycol monoethers; 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-(2-hydroxyethyl)-2-pyrrolidone (HEP) and other lactam compounds; methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tert-butanol, isobutanol, n-pentanol, 2-pentanol, 3-pentanol and tert-pentanol and other alcohols.

[0082] Among the above organic solvents, polyols having a trivalent or higher hydricity such as glycerol, glycols, and glycol monoethers are preferred. For example, at least one of glycerol (SP value = 16.7), propylene glycol (SP value = 14.2), 1,2-hexanediol (SP value = 12.2), and diethylene glycol monoisobutyl ether (SP value = 8.7) is more preferably used.

[0083] It is also preferred to use an SP value of 8.5 (cal / cm 3 ) 1 / 2 Above and 17.0 (cal / cm 3 ) 1 / 2 The following organic solvents.

[0084] It is also preferred to use an SP value of 8.5 (cal / cm3 ) 1 / 2 Above and 17.0 (cal / cm 3 ) 1 / 2 The following organic solvents, 9 (cal / cm 3 ) 1 / 2 Above and 13.5 (cal / cm 3 ) 1 / 2 The following organic solvents.

[0085] The solubility of acetylene glycol surfactants in water is low, and the ink composition dries and the water content decreases in the ejection nozzle of the inkjet head, which tends to cause ejection failure. Therefore, among the above organic solvents, by using an organic solvent having an SP value of 9 (cal / cm 3 ) 1 / 2 Above and 13.5 (cal / cm 3 ) 1 / 2 The following organic solvents are used, thereby further improving the solubility of the acetylene glycol surfactant in water and suppressing the tendency of poor discharge. Therefore, by using the above organic solvents, there is a tendency that the discharge stability and storage stability can be further reliably improved.

[0086] The SP value is 9 (cal / cm 3 ) 1 / 2 Above and 13.5 (cal / cm 3 ) 1 / 2 The content C of the organic solvent below is preferably 0.1% by mass or more and 20% by mass or less, and preferably 0.5% by mass or more and 15% by mass or less, and more preferably 1% by mass or more and 15% by mass or less. Furthermore, it is preferably 2 to 10% by mass, and more preferably 3 to 8% by mass.

[0087] When the content C is within the above range, there is a tendency that the discharge stability and storage stability can be further reliably improved.

[0088] The mass ratio (B / C) of the content B of the acetylene glycol surfactant to the content C of the organic solvent is preferably 0.3 or less, 0.2 or less, or 0.1 or less. By setting the mass ratio of B / C within the above range, there is a tendency to further reliably improve the ejection stability and storage stability. In addition, the above B / C may be 0.01 or more, or 0.02 or more.

[0089] The total content of the organic solvent in the ink is preferably 0.1 to 25 mass %, more preferably 3.0 to 20.0 mass %, more preferably 5.0 to 18.0 mass %, particularly preferably 10.0 to 15.0 mass %. The content within the above range is preferred because it provides better ejection stability and storage stability.

[0090] 1.1.4. Water

[0091] Examples of water include pure water and ultrapure water such as ion exchange water, ultrafiltration water, reverse osmosis water, and distilled water. The water content is preferably 40% by mass or more relative to the total amount of the ink composition. Further, it is more preferably 45% by mass or more and 98% by mass or less, 50% by mass or more and 95% by mass or less, 55% by mass or more and 90% by mass or less, or 70% by mass or more and 85% by mass or less.

[0092] The inkjet ink composition used in the present embodiment is a water-based ink. A water-based ink is an ink containing at least water as a main solvent component of the ink.

[0093] 1.1.5. Other ingredients

[0094] The ink composition of the present embodiment may further contain other components as necessary. Such components are not particularly limited, and examples thereof include a pH adjuster, a preservative, a wetting agent, a complexing agent, and the like.

[0095] The pH adjuster is not particularly limited, and examples thereof include ureas, amines, morpholines, piperazines, and amino alcohols such as triethanolamine. Among them, triethanolamine is preferred.

[0096] 1.1.6. Preparation method of ink composition

[0097] The ink composition of the present embodiment is prepared by mixing a pigment, a surfactant, water, and, if necessary, an organic solvent and other components. The method is not particularly limited, and the components can be mixed by a known method. In addition, the order of mixing is not particularly limited. For example, a pigment, a surfactant and water can be mixed to prepare a pigment dispersion, and then the pigment dispersion can be used to prepare the ink composition.

[0098] 1.2. Dissolved nitrogen

[0099] In the ink container of the present embodiment, the amount of dissolved nitrogen in the ink composition is 5 ppm or more. By setting the amount of dissolved nitrogen to 5 ppm or more, poor ejection caused by bubbles is particularly likely to occur, and the effect based on the present invention is remarkable. In addition, the amount of dissolved nitrogen in the ink composition is preferably 5 ppm or more and 20 ppm or less, 6 ppm or more and 18 ppm or less, or 8 ppm or more and 15 ppm or less. It should be noted that the amount of dissolved nitrogen tends to change depending on the method for preparing the ink composition and the material of the container for storing the ink composition.

[0100] The amount of dissolved nitrogen can be detected, for example, by gas chromatography or by mass conversion. For example, the detection device used in the examples described below can be cited.

[0101] 1.3.Container

[0102] The container for holding the ink composition involved in the present embodiment is not particularly limited, and examples thereof include: ink cartridges, ink packs, ink bottles, ink tanks, boxes, and tanks. Among them, ink cartridges, ink packs, ink bottles, and ink tanks are preferred from the viewpoint of versatility. Ink packs and ink bottles are more preferred. In addition, from the viewpoint of controlling air permeability, ink packs composed of components having a multilayer structure or ink bottles composed of resins are preferred. By using ink packs or ink bottles, there is a tendency to further effectively and reliably exert the effects of the present invention. It should be noted that, in the present embodiment, the ink container refers to a state in which the container contains ink.

[0103] The member having a multilayer structure is a member having two or more layers, and is, for example, a member having a resin film layer as a base material and a gas barrier layer as described later.

[0104] In addition, from the same viewpoint as above, the ink pack has a resin film substrate layer and a gas barrier layer, and the gas barrier layer preferably has at least one of a gas barrier resin layer and a metal or metal compound layer with a film thickness of 500 nm or less. On the other hand, the attachment of a metal foil layer (aluminum foil layer, etc.) tends to make the aluminum layer (metal foil layer) thicker, and although it has the advantages of high gas barrier properties and the dissolved nitrogen content is not likely to increase even after long-term storage, there is a tendency that the flexibility of the pack is poor and it is easy to be damaged. In addition, there is a tendency that the gas barrier layer is broken and loses the gas barrier properties.

[0105] In particular, large-capacity bags often deform due to the weight of the ink, and the above tendency is obvious. On the other hand, ink bags having a gas barrier layer other than a thick gas barrier layer such as a metal foil layer have advantages such as excellent flexibility and are not easily damaged even when the capacity is increased. However, the gas barrier property is low, and the amount of dissolved nitrogen in the contained ink composition is likely to increase. Therefore, the present invention becomes particularly useful.

[0106] The ink pack preferably has at least a resin film layer as a substrate for ensuring basic strength. The resin film layer as the substrate is not particularly limited, and for example, a substrate composed of a polyester resin (PET, etc.), a polyolefin resin (polyethylene, etc.), etc. is preferred. On the other hand, these substrates lack gas barrier properties, so it is preferred that a gas barrier layer is laminated on the substrate.

[0107] The gas barrier layer is not particularly limited, and is preferably a resin layer, a metal or a metal compound layer having excellent gas barrier properties. The metal or metal compound layer is preferably a layer having a predetermined thickness or less. The metal or metal compound layer is preferably a vapor-deposited layer, for example.

[0108] The resin layer with excellent gas barrier properties is not particularly limited, and examples thereof include nylon, ethylene-vinyl alcohol copolymer resin, polyvinylidene chloride, etc. In addition, the gas barrier properties can also be improved by increasing the thickness. In addition, the layer of metal or metal compound is not particularly limited, and examples thereof include metal layers such as aluminum and metal compound layers such as aluminum oxide, silicon oxide, cerium oxide, titanium dioxide, and zirconium oxide. In addition, as the vapor-deposited layer, aluminum vapor-deposited layers and vapor-deposited layers such as aluminum oxide and silicon oxide can be listed. Such a gas barrier layer tends to be thinner than a metal foil and also has excellent flexibility.

[0109] The capacity of the container is preferably 100 ml or more. More preferably, it is 500 ml or more, 800 ml or more, or 1 L or more. There is no upper limit, but for example, it is preferably 10 L or less, and more preferably 5 L or less. When the capacity of the container is above the above, there is a tendency that the parts of the container are easily broken or damaged due to the weight of the ink container, so the ink container of this embodiment is particularly useful.

[0110] The present invention is particularly useful in that it is possible to suppress a decrease in discharge stability that occurs in the case of a large-capacity ink container.

[0111] The material of the resin film substrate layer in the ink pack is not particularly limited. Examples thereof include polyethylene terephthalate (PET), nylon, and polyethylene (PE). The thickness of the resin film substrate layer is preferably 10 μm to 300 μm, and 20 μm to 250 μm. It is further preferably 50 to 200 μm, and more preferably 70 to 150 μm.

[0112] As the gas barrier layer in the ink pack, a gas barrier resin layer composed of a resin, or a layer of a metal or a metal compound is preferable.

[0113] When it is a gas barrier resin layer, the resin is not particularly limited, and examples thereof include nylon, ethylene-vinyl alcohol, and polyvinylidene chloride. These resin layers can be formed by bonding or vapor deposition. The thickness of the gas barrier resin layer is preferably 5 μm to 200 μm, 10 μm to 150 μm, and more preferably 20 to 100 μm.

[0114] In the case of a layer of a metal or a metal compound, the thickness of the layer is preferably 10 nm to 500 nm, 20 nm to 300 nm, more preferably 30 to 200 nm, and even more preferably 30 to 100 nm.

[0115] When forming a layer of a metal or a metal compound, in order to make the film thickness below a predetermined level in consideration of flexibility, a vapor deposition method, a CVD method, a sputtering method, an ion plating method, etc. are preferably used, and a vapor deposition method is more preferably used.

[0116] As a container of this embodiment, an ink pack is taken as an example. Figure 6 1 is an exploded perspective view showing an example of an ink pack. The ink cartridge 10 is composed of an ink pack 40 filled with ink and an ink cartridge case 42, and the ink cartridge case 42 is composed of a main body shell 46 and a cover 48 that place the ink pack 40 inside for protection. The ink pack 40 has an ink supply port 44. The main body shell 46 has a cutout portion 50 and a groove portion 56, and the cover 48 has a pressing portion 52 and a hook portion 54. In the ink cartridge 10, the ink pack 40 is placed in the main body shell 46 and the cover 48, and at this time, the ink supply port 44 is fixed by being sandwiched by the pressing portion 52 and the cutout portion 50 on the basis of being inserted into the cutout portion 50. In addition, the main body shell 46 and the cover 48 are sealed by the hook portion 54 and the groove portion 56 being engaged.

[0117] For example, a film-shaped member that constitutes the ink pack 40 and contains ink in the ink pack may be used as a member that constitutes the ink pack.

[0118] Ink bottles include those used to replenish ink for CISS printers, etc. Ink bottles are preferably made of resin from the viewpoint of lightness and cost efficiency, but the airtightness of the cap and the gas barrier property of the container itself are low, so dissolved nitrogen tends to increase.

[0119] As the container of the present embodiment, an ink bottle is exemplified. Figure 7 A cross-sectional view showing an example of an ink bottle is shown. The ink bottle 63 contains the above-mentioned ink composition (ink composition IK). The ink bottle 63 includes: a cylindrical container body 64 as its main body; an ink outlet forming portion 66 provided at the top end of the container body 64 and having an ink outlet 65 formed at the top end, the ink outlet 65 being able to allow the ink in the ink bottle 63 to flow out; and a container addition portion 67 added to the ink outlet forming portion 66 so as to surround the ink outlet 65. The ink outlet 65 of the ink outlet forming portion 66 is covered by a cap 68 having a bottom cylindrical shape including the container addition portion 67 around it, so that it can be hidden from the outside when the ink bottle 63 is stored.

[0120] The container body 64 in the ink bottle 63 is a bottle-shaped member having an ink containing chamber 76 capable of containing the ink composition IK therein, and an external threaded portion 78 is formed on the outer peripheral surface of the neck 77 at the upper end thereof. On the other hand, the ink outlet forming portion 66 provided at the upper end of the container body 64 includes: a large diameter portion 79 located on the outer peripheral side of the neck 77 of the container body 64; a small diameter portion 80 forming the ink outlet 65 at a position farthest from the container body 64; and an intermediate portion 81 connecting the large diameter portion 79 and the small diameter portion 80.

[0121] The bottle-shaped member is preferably made of polyolefin resin such as polypropylene, for example. Such a member is excellent in impact resistance and is therefore preferred, but has low gas barrier properties and is particularly useful for the ink container of this embodiment.

[0122] In addition, in the container of the present embodiment, by setting the dissolved nitrogen concentration to 5 ppm or more, it is possible to omit the process of fully degassing the ink in order to make it less than 5 ppm, for example, and thus reduce the workload of ink manufacturing. In addition, it is not necessary to set the ink tank to have a high gas barrier property, and the freedom of container design is increased. As a result, for example, a component with excellent flexibility can be used, resulting in a larger container capacity or a lower cost of the container.

[0123] In addition, after the ink container is manufactured, the ink container may be used in a recording device after a predetermined time has passed. In this case, the dissolved nitrogen concentration of the ink composition may increase to 5 ppm or more after a predetermined time has passed after the ink container is manufactured. In this case, the dissolved nitrogen concentration of the ink composition contained in the container of the ink container may be 5 ppm or more as long as the dissolved nitrogen concentration is 5 ppm or more when the ink container is used in the recording device.

[0124] In this case, for example, time may elapse for storage and transportation after the ink container is manufactured. In this case, storage and transportation of the ink container may take time, and for example, transportation costs can be reduced or the life of the ink container can be extended.

[0125] 2. Inkjet recording method

[0126] The inkjet recording method of the present embodiment includes a sticking step of ejecting the inkjet ink composition supplied from the ink container from an inkjet head to make it stick to a recording medium.

[0127] 2.1. Attachment process

[0128] The attachment step is a step of ejecting the ink composition supplied from the ink container from the inkjet head and causing it to attach to the recording medium.

[0129] As an example of a recording device used in the recording method of this embodiment, Figure 8 A perspective view of a printer is shown. Figure 8 The inkjet recording device 1 includes an ink tank 50 and an ink supply tube 24 for supplying ink from the ink tank 50 to the inkjet head 17. A sub-tank 20 for transferring ink is provided in the ink supply path between the ink tank 50 and the inkjet head 17. The sub-tank 20 for transferring ink may be provided as required.

[0130] The ink tank 50 has an ink injection port 54 for injecting ink from an ink container (not shown). In the present embodiment, the ink container is an ink bottle, and the ink in the ink bottle is injected into the ink tank 50 from the ink injection port 54 .

[0131] The recording device of this embodiment is a recording device in which the ink tank 50 is a CISS container (continuous ink supply system container), and the ink can be injected into the ink tank 50 from the ink bottle at any time, thereby eliminating the need to replace the ink cartridge and enabling continuous recording without interruption.

[0132] The ink tank 50 is composed of, for example, four ink tanks so that four types of ink can be injected, and also has four ink injection ports. There are also four ink supply pipes 24 from the ink jet head 17 .

[0133] The inkjet head 17 ejects droplets of the ink composition to record an image on the recording medium. In addition, it has: a carriage 16 that carries the sub-tank 20 and the inkjet head 17 and can reciprocate in the X-axis direction; a paper feed port 12 that feeds the recording medium; a paper discharge port 14 that discharges the recording medium; and a support portion 13 that supports the recording medium fed by the paper feed port 12. The inkjet head 17 has a nozzle face provided at a position facing the recording surface of the recording medium, and ejects ink in the form of droplets from a plurality of nozzles provided on the nozzle face so that the ink adheres to the recording surface of the recording medium.

[0134] The inkjet recording method of this embodiment is preferably performed using a recording device, the recording device comprising: an ink tank, the container being an ink bottle, and having an ink injection port for injecting an inkjet ink composition from the ink bottle; and an inkjet head, the inkjet ink composition being supplied from the ink tank. In this case, the ink is also supplied from the ink bottle to the inkjet head.

[0135] The recording device used in this embodiment is not limited to the above. For example, the ink container (not shown) may be an ink pack, an ink cartridge having the ink pack may be mounted on the recording device, and ink may be supplied from the ink cartridge mounted on the recording device to the inkjet head 17 via the ink supply tube 24. In this case, the ink tank 50 may not be provided.

[0136] 2.2. Drying process

[0137] The drying step is a step of drying the ink composition on the recording medium by heating the recording medium, etc. The inkjet recording method of this embodiment may include a drying step.

[0138] 3. Ink container group

[0139] The present embodiment may be a group of ink containers (ink container group) including at least two or more of the above-mentioned ink containers.

[0140] The inks contained in the two or more ink containers included in the ink container group may include basic color inks such as black ink, yellow ink, magenta ink, and cyan ink, and may also include special color inks other than the basic color inks.

[0141] The ink container of the present embodiment is preferably a yellow-red ink such as yellow ink, magenta ink, orange ink, or red ink because the hue angle that can be recorded in warm colors is wide. Furthermore, inks of the colors described above are more preferred.

[0142] The inkjet recording method of the present embodiment can also be performed using the above-mentioned set of ink containers.

[0143] Example

[0144] The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited to the following examples.

[0145] 1. Preparation of ink composition

[0146] exist Figures 1 to 5 Tables 1 to 5 showing the compositions of the ink compositions are described in FIG.

[0147] The inkjet ink composition in each example is obtained by adding each component to a mixing tank to obtain the composition described in Tables 1 to 5, mixing and stirring, and filtering with a membrane filter. It should be noted that the numerical value of each component shown in each example in the table is expressed as mass % unless otherwise specified. In addition, in the table, the numerical value of the pigment dispersion is expressed as the mass % of the pigment solid content.

[0148] The pigment is prepared by mixing the pigment and a water-soluble styrene acrylic resin, i.e., a dispersant resin (not shown in the table), in water at a mass ratio of 3:1 and stirring to prepare a pigment dispersion, which is used for ink preparation.

[0149] All inks are yellow-red inks, and in particular, yellow-red inks other than yellow ink. Ink using two kinds of pigments is an ink having a wide range of recordable hue angles.

[0150] The details of the pigments and products used in Tables 1 to 5 are as follows, and the HLB values ​​of the surfactants and the SP values ​​of the organic solvents are shown in the tables.

[0151] Pigment dispersion

[0152] A: Perylene pigments (PO43, Perylene Orange 43)

[0153] ·B: Azo pigments (PR150, Pigment Red 150)

[0154] C: Quinacridone pigments (PR122, Pigment Red 122)

[0155] ·D: Azo pigments (PR242, Pigment Red 242)

[0156] Surfactants

[0157] ·KF-640 (trade name, manufactured by Shin-Etsu Silicone Co., Ltd.)

[0158] ·FZ-2105 (trade name, manufactured by Toray Dowcorning Silicon Co., Ltd.)

[0159] ·KF-6015 (trade name, manufactured by Shin-Etsu Silicone Co., Ltd.)

[0160] · SURFYNOL 104E (trade name, manufactured by Air product and Chemicals. Inc.) · SURFYNOL SE (trade name, manufactured by Air product and Chemicals. Inc.) · SURFYNOL 440 (trade name, manufactured by Air product and Chemicals. Inc.) · SURFYNOL 465 (trade name, manufactured by Air product and Chemicals. Inc.)

[0161] 2. Containment in a container

[0162] Figures 1 to 5 Tables 1 to 5 showing the types of containers used are described in the table.

[0163] A container was prepared in which each ink composition was filled in one of the containers 1 to 4 prepared by the following preparation method and stored at room temperature until the test period described in the table. Containers 1 to 3 used a low-density polyethylene film with a thickness of 80 μm as a base material, and the capacity of any container was 1 L, and 1 L of the ink composition was contained.

[0164] Composition of each container

[0165] Container 1: A 30 nm thick aluminum layer was formed on one surface of a substrate by vapor deposition. Then, using the obtained film, a container (ink pack) for containing an ink composition was prepared with the aluminum layer as the outer surface.

[0166] Container 2: A 10 μm thick aluminum layer was formed on one surface of a substrate by vapor deposition, and a container (ink pack) for containing an ink composition was prepared using the obtained film with the aluminum layer as the outer surface.

[0167] Container 3: A nylon film having a thickness of 30 μm was laminated on one surface of a substrate, and a container (ink pack) for containing an ink composition was prepared using the obtained film so that the nylon film layer was the outer surface.

[0168] Container 4: A bottle-shaped container (ink bottle) was formed by stretch blow molding using polyethylene.

[0169] After storage, the amount of dissolved nitrogen in the ink in the container was detected. The amount of dissolved nitrogen was determined by mass conversion using a gas chromatograph (6890N, manufactured by Agilent). The detected values ​​are recorded in the table. It should be noted that the amount of dissolved nitrogen in the ink before filling the container was 4 ppm.

[0170] In the evaluation described later, the ink container after storage was used.

[0171] 3. Evaluation Method

[0172] 3.1. Ejection stability

[0173] 3.1.1. Continuous ejection

[0174] A modified inkjet printer PX-H6000 (manufactured by Seiko Epson Corporation) was prepared, and the inkjet ink composition was filled therein.

[0175] In an example where the container of the ink container is an ink pack, the recording device is set to supply ink from an ink cartridge having the ink pack to an inkjet head via an ink supply tube. In an example where the container of the ink container is an ink bottle, the recording device is set to include an ink tank having an ink injection port, ink is injected from the ink bottle into the ink injection port of the ink tank, and ink is supplied from the ink tank to the inkjet head via the ink supply tube.

[0176] Printer paper "P" (A4 size) manufactured by Fuji Xerox was placed and continuous printing was performed at a resolution of 720 dpi x 1440 dpi. A nozzle check was performed for every 10 sheets to confirm whether normal printing was possible without any non-ejection, scattering, or distortion. The evaluation criteria are as follows.

[0177] Evaluation Criteria

[0178] A: More than 100 sheets can be printed normally

[0179] B: Printing is normal within the range of 10 or more and less than 100 sheets.

[0180] C: No ejection or scattering and distortion occurred at 10 images.

[0181] 3.1.2. Blockage resistance

[0182] The inkjet ink composition of each embodiment and comparative example was filled into the above recording device, and it was confirmed that all columns were ejected normally. Then, the print head was placed in a state where it deviated from the standby position and stopped in the printing area, and was placed in an environment of 40°C and 20%RH for 3 days. After being placed, the print head was returned to the standby position for cleaning. The cleaning was to suck 1cc of ink from the nozzle on the nozzle surface of the specified nozzle group (600 nozzles) of the inkjet head, and then wiped manually with a rubber scraper.

[0183] Then, the number of cleaning times required until the ejection was restored (no non-ejecting nozzles) was counted. The evaluation criteria are as follows.

[0184] Evaluation Criteria

[0185] A: After cleaning less than 3 times, all nozzles have been restored

[0186] B: All nozzles have been restored after cleaning more than 4 times and less than 9 times

[0187] C: No recovery after 9 cleanings

[0188] 3.2. Storage stability

[0189] Each ink composition of the ink container was taken out, added to a 50cc glass sample bottle and sealed, and the glass bottles were placed in a 50°C constant temperature bath and placed in a 50°C environment for 14 days. After the placement, the viscosity was tested after returning to room temperature. The viscosity was obtained by adjusting the temperature of the ink composition to 25°C using a viscoelasticity tester MCR-300 (product name) from Pysica and reading the viscosity when the Shear Rate was 200. In addition, the viscosity change rate A after 14 days relative to the initial viscosity was calculated. The evaluation criteria are as follows.

[0190] Evaluation Criteria

[0191] A: Viscosity change rate A is less than ±5%

[0192] B: Viscosity change rate A is more than ±5% and less than 10%

[0193] C: Viscosity change rate A is more than ±10%

[0194] 4. Evaluation results of the examples

[0195] Tables 1 to 4 show the composition of the inkjet ink composition used in each example, the storage method in the container, and the evaluation results. As shown in Tables 1 to 4, the ink container of the present embodiment has an inkjet ink composition and a container for storing the inkjet ink composition, the inkjet ink composition contains an aqueous ink of a pigment and a surfactant, the pigment contains at least two pigments of different chemical structures, the surfactant contains a polysiloxane surfactant with an HLB value of 10 or more and an acetylene glycol surfactant with an HLB value of 6 or more and 10 or less, the amount of dissolved nitrogen in the inkjet ink composition stored is 5 ppm or more, and the ink container of the present embodiment has excellent ejection stability (ejection evaluation). And the storage stability is also excellent.

[0196] On the other hand, the ejection evaluation results of the comparative examples which were not the ink containers according to the present embodiment were all poor.

[0197] 5. Reference examples

[0198] Reference Examples 1 to 5 were prepared and evaluated in the same manner as in the Examples by the above-described method. Table 5 shows the composition of the inkjet ink composition, the storage method in the container, and the evaluation results. As can be seen from Tables 1 to 5, technical problems with ejection stability may arise depending on the amount of dissolved nitrogen in the ink container, the number of pigment types, and the like.

Claims

1. An ink container, characterized in that: having an inkjet ink composition and a container containing the inkjet ink composition, The inkjet ink composition is a water-based ink containing a pigment and a surfactant. The pigment comprises at least two pigments of different chemical structures, The surfactant comprises a polysiloxane-based surfactant having an HLB value of 10 or more and an acetylene glycol-based surfactant having an HLB value of 6 or more and 10 or less, The amount of dissolved nitrogen in the contained inkjet ink composition is 5 ppm or more.

2. The ink container according to claim 1, characterized in that: The mass ratio of the content A of the polysiloxane-based surfactant to the content B of the acetylene glycol-based surfactant, that is, A / B, is 0.3 or more and 8.0 or less.

3. The ink container according to claim 1, wherein: The inkjet ink composition has an SP value of 9 (cal / cm 3 ) 1 / 2 Above and 13.5 (cal / cm 3 ) 1 / 2 The following organic solvents.

4. The ink container according to claim 3, characterized in that: The content C of the organic solvent is 0.5% by mass or more and 15% by mass or less relative to the total amount of the inkjet ink composition.

5. The ink container according to claim 3, characterized in that: The mass ratio of the content B of the acetylene glycol-based surfactant to the content C of the organic solvent, that is, B / C, is 0.3 or less.

6. The ink container according to claim 1, wherein: The container is an ink pack composed of members having a multi-layer structure or an ink bottle composed of resin.

7. The ink container according to claim 1, characterized in that: The container is an ink bag composed of a member having a multi-layer structure or an ink bottle composed of a resin, The ink pack comprises a resin film substrate layer and a gas barrier layer, The gas barrier layer includes at least one of a gas barrier resin layer and a metal or metal compound layer having a film thickness of 500 nm or less.

8. The ink container according to claim 1, wherein: The container is an ink bag composed of a member having a multi-layer structure or an ink bottle composed of a resin, The ink pack comprises a resin film substrate layer and a gas barrier layer, The gas barrier layer comprises at least one of a gas barrier resin layer and a metal or metal compound layer having a film thickness of 500 nm or less. The metal or metal compound layer is a vapor-deposited layer.

9. The ink container according to claim 1, characterized in that: The amount of dissolved nitrogen is 5 ppm or more and 20 ppm or less.

10. The ink container according to claim 1, wherein: The capacity of the container is 800 mL or more.

11. The ink container according to claim 1, characterized in that: The pigment includes two pigments of different chemical structures selected from the group consisting of azo compounds, quinacridone compounds, dioxazine compounds, pyrenone compounds, perylene compounds, and diketopyrrolopyrrole compounds.

12. The ink container according to claim 1, characterized in that: The pigment comprises: a first pigment compound which is an azo compound; as well as The second pigment compound is at least one selected from the group consisting of quinacridone compounds, dioxazine compounds, pyrenone compounds, perylene compounds, and diketopyrrolopyrrole compounds.

13. The ink container according to claim 1, characterized in that: The content A of the polysiloxane-based surfactant is 0.3% by mass or more and 1.5% by mass or less relative to the total amount of the inkjet ink composition.

14. The ink container according to claim 1, characterized in that: The content B of the acetylene glycol surfactant is 0.1% by mass or more and 1.0% by mass or less relative to the total amount of the inkjet ink composition.

15. The ink container according to claim 1, characterized in that: The hue of the inkjet ink composition is yellow-red.

16. The ink container according to claim 1, characterized in that: The mass ratio of the content A of the polysiloxane-based surfactant to the content B of the acetylene glycol-based surfactant, that is, A / B, is 1.2 or more and 4.0 or less.

17. An inkjet recording method, characterized in that: The inkjet recording method comprises: an attachment step of ejecting the inkjet ink composition supplied from the ink container according to any one of claims 1 to 16 from an inkjet head and attaching the inkjet ink composition to a recording medium.

18. The inkjet recording method according to claim 17, wherein: The container is an ink bottle, The inkjet recording method is performed using a recording device, The recording device includes: an ink tank having an ink injection port for injecting the inkjet ink composition from the ink bottle; and an inkjet head to which the inkjet ink composition is supplied from the ink tank.

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