Ink container and ink composition

Abstract

To provide an ink accommodating body capable of accommodating an ink composition having good ozone resistance fastness, with high storage stability.SOLUTION: An ink accommodating body accommodating an ink composition is provided, wherein the ink composition contains water and a first dye, which is a compound represented by the following formula or a salt thereof, and wherein the ratio (A / V) is 1.7 or less where A (cm2) is a total surface area of a metal in contact with the ink composition within the ink accommodating body, and V (cm3) is an accommodation capacity for the ink composition accommodated in the ink accommodating body.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an ink container and an ink composition. [Background technology]

[0002] In the inkjet recording method, when an achromatic image is formed using black ink alone, a grainy texture may appear if the achromatic color is light. In order to eliminate the grainy texture, it is known to form an achromatic area by using black ink, yellow ink, magenta ink, and cyan ink in combination.

[0003] For example, Patent Document 1 discloses an inkjet recording method in which a black ink containing a specific black dye and a color ink containing a specific dye are applied to a recording medium at a duty of 30% or less to record an achromatic image, and describes that even with a low duty, an achromatic image that is excellent in hue, graininess, and ozone resistance can be obtained. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-168942 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, some of the specific dyes that may improve the graininess and ozone fastness of the resulting image have poor storage stability, and color development may deteriorate due to storage. The chemical structure of the dye is considered to be one of the causes of the deterioration of color development due to storage, but the mechanism has not been fully elucidated. In other words, an ink container that can store an ink composition with good ozone fastness and good storage stability is desired. [Means for solving the problem]

[0006] One aspect of the ink container according to the present invention is An ink container containing an ink composition, The ink composition contains water and a first dye which is a compound represented by the following formula (B-1) or a salt thereof: the content of the first dye in the ink composition is 0.5% by mass or more with respect to the total amount of the ink composition; The total surface area of ​​the metal that the ink composition contacts in the ink container is defined as A (cm 2 ), and the volume of the ink composition contained in the ink container is V (cm 3 ), the ratio (A / V) is 1.7 or less.

[0007] [ka] ...Formula (B-1)

[0008] One embodiment of the ink composition according to the present invention comprises: Water, a first dye which is a compound represented by the following formula (B-1) or a salt thereof, A second dye selected from a compound represented by the following formula (M-1) or a salt thereof, and a compound represented by the following formula (M-2) or a salt thereof, Contains The content of the first dye is 0.5% by mass or more based on the total amount.

[0009] [ka] ...Formula (B-1)

[0010] [ka] ...Formula (M-1)

[0011] [ka] ...Formula (M-2)

[0012] One embodiment of the ink composition according to the present invention comprises: An ink composition contained in an ink container, The ink composition contains water and a first dye which is a compound represented by the following formula (B-1) or a salt thereof: the content of the first dye is 0.5% by mass or more relative to the total amount of the ink composition; The total surface area of ​​the metal that the ink composition contacts in the ink container is defined as A (cm 2 ), and the volume of the ink composition contained in the ink container is V (cm 3 ), the ratio (A / V) is 1.7 or less.

[0013] [ka] ...Formula (B-1) [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a recording apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing an ink supply unit provided in a housing of the recording apparatus. [Diagram 3] FIG. [Figure 4] FIG. 4 is a partially broken cross-sectional view taken along line 4-4 in FIG. [Diagram 5] FIG. 5 is a partially broken cross-sectional view taken along line 5-5 in FIG. [Figure 6] FIG. 4 is a perspective view of the ink container with the cap removed. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. [Figure 11] 11 is a cross-sectional view taken along line 11-11 in FIG. 9 . [Figure 12] FIG. 4 is a partially cutaway front view showing a state immediately before an ink refill operation is performed on the ink tank. [Figure 13] FIG. 4 is a partially cutaway side view showing a state immediately before an ink refill operation is performed on an ink tank. [Figure 14] FIG. 4 is a partially cutaway front view showing a state in which ink is being refilled into the ink tank; [Figure 15] FIG. 4 is a partially cutaway side view showing a state in which ink is being refilled into the ink tank. [Figure 16] 13 is a partially cutaway front view showing a state in which a positioning portion of the ink accommodating body abuts against a receiving surface on the ink tank side during ink refilling. FIG. [Figure 17] 13 is a partially cutaway side view showing a state in which a positioning portion of the ink accommodating body abuts against a receiving surface on the ink tank side during ink refilling. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The following describes an embodiment of the present invention. The embodiment described below is an example of the present invention. The present invention is not limited to the following embodiment, and includes various modified forms that are implemented within the scope of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

[0016] 1. Ink container The ink container according to this embodiment is an ink container that contains an ink composition. The ink composition contained in the ink container contains water and a first dye. The content of the first dye in the ink composition is 0.5 mass % or more with respect to the total amount of the ink composition, and the total surface area of ​​the metal with which the ink composition comes into contact in the ink container is A (cm 2 ), and the volume of the ink composition contained in the ink container is V (cm 3 ), the ratio (A / V) is 1.7 or less.

[0017] Hereinafter, the ink composition contained in the ink container will be described, and then the ink container will be described.

[0018] 1.1. Ink composition The ink composition contained in the ink container of this embodiment contains water and a first dye. The ink composition is particularly suitable for inkjet recording, and may be used as an inkjet ink composition.

[0019] 1.1.1.Water The ink composition according to the present embodiment contains water. Examples of water include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, and ultrapure water from which ionic impurities have been removed as much as possible. Furthermore, by using water sterilized by ultraviolet irradiation or the addition of hydrogen peroxide, the growth of bacteria and fungi can be suppressed when the ink composition is stored for a long period of time.

[0020] The water content is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more, based on the total amount (100% by mass) of the ink composition. By having a water content of 40% by mass or more, the viscosity of the ink composition can be sufficiently reduced. Furthermore, the upper limit of the water content is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less, based on the total amount of the ink composition.

[0021] 1.1.2.First dye The ink composition according to this embodiment contains a first dye which is a compound represented by the following formula (B-1) or a salt thereof.

[0022] [ka] ...Formula (B-1)

[0023] Examples of the salt of the compound represented by formula (B-1) include compounds in which at least one of the H of the four SO3H groups is independently Li, Na, K, or NH3. That is, examples of the salt of the compound represented by formula (B-1) include lithium salt, sodium salt, potassium salt, ammonium salt, and mixed salts thereof. In addition, when the salt of the compound represented by formula (B-1) is ionized in an aqueous solution, it can be said that at least one of hydrogen ion, lithium ion, sodium ion, potassium ion, and ammonium ion is present in the aqueous solution.

[0024] The first dye is a black dye and has a maximum absorption wavelength of 550 nm or more and 630 nm or less. By including the first dye in the ink composition, it is possible to obtain a black ink or gray ink that is easy to develop a neutral black (black that is not bluish or reddish).

[0025] Furthermore, since the first dye has excellent ozone fastness, the ozone fastness of the image formed using the ink composition of this embodiment can be improved.

[0026] 1.1.3.Other dyes The ink composition of this embodiment may contain the following dyes in addition to the first dye.

[0027] 1.1.3.(1) Second dye The ink composition may contain a second dye having a maximum absorption wavelength in the range of 500 nm to 580 nm. The dye having a maximum absorption wavelength in the range of 500 nm to 580 nm has a magenta hue.

[0028] When the ink composition contains a second dye, the hue of the image formed by the ink composition can be made closer to neutral.

[0029] The second dye may be a mixture of a plurality of dyes. When the ink composition contains the second dye, the total content of the second dye in the ink composition is 0.15% by mass or more and 5.0% by mass or less, preferably 0.2% by mass or more and 2.0% by mass or less, more preferably 0.3% by mass or more and 0.5% by mass or less, based on the total amount of the ink composition.

[0030] Furthermore, when the ink composition contains a second dye, in terms of the ratio to the first dye, the total content of the second dye, as a mass ratio of the content of the second dye to the content of the first dye, is preferably 0.05 or more and 1.00 or less, more preferably 0.1 or more and 0.8 or less, and even more preferably 0.1 or more and 0.5 or less, when the content of the first dye is 1.

[0031] From the viewpoints of color development, ozone resistance, light resistance, and the like, the second dye is more preferably selected from a compound represented by the following formula (M-1) or a salt thereof, a compound represented by the following formula (M-2) or a salt thereof, and a compound represented by the following formula (M-3) or a salt thereof.

[0032] [ka] ...Formula (M-1)

[0033] [ka] ...Formula (M-2)

[0034] [ka] ...Formula (M-3)

[0035] In formula (M-1), formula (M-2) and formula (M-3), each of the structures contains several acid groups, which may each be in the form of an acid salt independently. Counter cations of the salt include hydrogen ions (protons), lithium, sodium, potassium, ammonium, etc., and the counter cations in each acid group may be the same or different.

[0036] Furthermore, the second dye is more preferably selected from the compound represented by the above formula (M-1) or its salt, and the compound represented by the above formula (M-2) or its salt, in order to further improve color development, ozone resistance, light resistance, etc. In particular, formula (M-1) is preferred because it tends to maintain good ozone resistance. In particular, formula (M-2) is preferred from the viewpoint of improving color development.

[0037] When the second dye is selected from the compound represented by formula (M-1) or a salt thereof, and the compound represented by formula (M-2) or a salt thereof, the hue of the image formed by the ink composition can be made closer to neutral.

[0038] When the second dye is used, the ink composition can produce an image with a more neutral hue because the second dye functions as a complementary color to the color of the first dye contained in the ink composition, and the first dye has a slight green tint.

[0039] When the ink composition contains both the compound represented by formula (M-1) or its salt and the compound represented by formula (M-2) or its salt as the second dye, the ink composition has a preferred content ratio. That is, in this case, the content of the compound represented by formula (M-1) or its salt in the ink composition is more preferably smaller than the content of the compound represented by formula (M-2) or its salt in the ink composition. This makes it possible to form an image of a neutral hue while maintaining good ozone resistance.

[0040] 1.1.3.(2) Tertiary dye The ink composition may contain a third dye having a maximum absorption wavelength less than 480 nm. The dye having a maximum absorption wavelength in the range less than 480 nm has a yellow hue.

[0041] When the ink composition contains a third dye, the hue of the image formed by the ink composition can be made closer to neutral.

[0042] The third dye may be a mixture of multiple dyes. When the ink composition contains the third dye, the total content of the third dye in the ink composition is 0.15% by mass or more and 5.0% by mass or less, preferably 0.2% by mass or more and 2.0% by mass or less, and more preferably 0.2% by mass or more and 0.5% by mass or less, based on the total amount of the ink composition.

[0043] Furthermore, when the ink composition contains a third dye, in terms of the ratio to the first dye, the total content of the third dye, as a mass ratio of the content of the third dye to the content of the first dye, when the content of the first dye is taken as 1, is preferably 0.05 or more and 1.00 or less, more preferably 0.1 or more and 0.8 or less, and even more preferably 0.1 or more and 0.5 or less.

[0044] From the viewpoints of color development, ozone resistance, light resistance, and the like, the third dye is more preferably selected from a compound represented by the following formula (Y-1) or a salt thereof, and a compound represented by the following formula (Y-2) or a salt thereof.

[0045] [ka] Formula (Y-1)

[0046] [ka] Formula (Y-2)

[0047] In formula (Y-1) and formula (Y-2), each of the structures contains several acid groups, which may be in the form of an acid salt independently. Counter cations of the salt include hydrogen ions (protons), lithium, sodium, potassium, ammonium, etc., and the counter cations in each acid group may be the same or different.

[0048] Furthermore, the third dye is more preferably a compound represented by the above formula (Y-1) or a salt thereof, in terms of further improving color development, ozone fastness, light fastness, and the like.

[0049] When the third dye is a compound represented by formula (Y-1) or a salt thereof, the hue of the image formed from the ink composition can be made closer to neutral.

[0050] 1.1.3.(3) Other dyes The ink composition of the present embodiment may contain coloring materials other than the first dye, the second dye, and the third dye. Examples of such coloring materials include CI Acid Black 1, 2, 24, 41, 94, CI Direct Black 19, 29, 38, 51, 71, 122, 154, 168, 195, CI Reactive Black 3, 4, 5, 8, 13, 14, 31, 34, 35, 39, CI Basic Black 2, 8, CI Direct Red 1, 4, 9, 80, 81, 225, CI Acid Red 52, 80, 82, 249, 254, 289, and the like. However, it is preferable to use these coloring materials in an amount of 0.5% by mass or less, preferably 0.3% by mass or less, and more preferably 0.1% by mass or less, based on the total amount of the ink composition. That is, it is preferable to use the above-mentioned first dye, second dye, and third dye as main dyes in the ink composition.

[0051] 1.1.3.(4) Neutral hues The ink composition of the present embodiment has a hue ranging from approximately black to gray, and by using at least one of the second dye, the third dye, and the other dyes as necessary, it is easy to obtain a so-called neutral hue that is black or gray and has little other coloring. * The absolute value of the value is less than 2.5, b * The absolute value of the value is about 2.5 or less, and more preferably a * The absolute value of the value is less than 1.5, b * This indicates that the absolute value of the value is less than 1.5.

[0052] 1.1.4. Dye content In the ink composition of this embodiment, the total amount of dye solids is preferably 6.8% by mass or less, more preferably 6.0% by mass or less, and even more preferably 5.0% by mass or less, based on the total amount of the ink composition. This makes it possible to improve clogging recovery. In addition, the graininess of the resulting image can be further suppressed, and an image with a neutral hue can be formed. In addition, the total amount of dye solids is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, based on the total amount of the ink composition.

[0053] 1.1.5. Other ingredients other than dyes 1.1.5.(1) Alkanolamines The ink composition may further contain an alkanolamine having 3 or more carbon atoms. Examples of alkanolamines include, but are not limited to, mono-, di-, or tri-C1-C4 alkanolamines such as diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine. The number of carbon atoms in an alkanolamine is the total number of carbon atoms. Among these, trialkanolamines having a hydroxyalkyl group having 3 or more carbon atoms are more preferable from the viewpoint of improving the storage stability of the ink composition. Examples of such alkanolamines include triisopropanolamine.

[0054] When the ink composition contains an alkanolamine, the hue of the image obtained is more neutral. The ink composition may contain multiple types of alkanolamine. Furthermore, when the ink composition contains an alkanolamine, it is more preferable that the total content of the alkanolamine and the content of the first dye satisfy the relationship of the following formula (1). 0.1<(alkanolamine content) / (first dye content)<0.6...(1) This allows for the production of images with more neutral hues.

[0055] 1.1.5.(2) Organic acids The ink composition may contain an organic acid. The organic acid is not limited to, but examples thereof include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, malic acid, malonic acid, citric acid, succinic acid, and adipic acid.

[0056] When the ink composition contains an organic acid, it is easy to obtain an image with a more neutral hue. The ink composition may contain a plurality of organic acids. Furthermore, when the ink composition contains an organic acid, the total content of the organic acids and the content of the first dye may satisfy the relationship of the following formula (2). 0.01<(organic acid content) / (first dye content)<0.1 (2) This allows for the production of images with more neutral hues.

[0057] 1.1.5.(3) Other ingredients The ink composition of this embodiment may contain a surfactant, an organic solvent, and other components.

[0058] 1) Surfactants A surfactant may be added to the ink composition. The surfactant has a function of lowering the surface tension of the ink composition and increasing the permeability into the recording medium. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, and at least one of these can be used.

[0059] When a surfactant is added to the ink, the content is 0.01% by mass or more and 3.00% by mass or less, based on the total mass of the ink. Preferably, the content is 0.05% by mass or more and 2.00% by mass or less, more preferably, 0.10% by mass or more and 1.00% by mass or less, and even more preferably, 0.20% by mass or more and 0.50% by mass or less. By setting the content of the surfactant within the above range, foaming can be suppressed to ensure ejection stability during printing, and the ink can be improved in wettability (wettability) when attached to a recording medium.

[0060] As the nonionic surfactant, an acetylene glycol surfactant, a fluorine-based surfactant, a silicone-based surfactant, etc. By using these surfactants, it is possible to improve the wettability of the recording medium with a relatively small content.

[0061] The acetylene glycol surfactant is not particularly limited, but examples thereof include alkylene oxide adducts such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, alkylene oxide adducts of 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4-dimethyl-5-decyne-4-ol, alkylene oxide adducts of 2,4-dimethyl-5-decyne-4-ol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3-ol, and 2,4-dimethyl-5-hexyne-3-ol.

[0062] As such an acetylene glycol surfactant, commercially available products may be used, for example, Surfynol (registered trademark) 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 (trade name, Air Products and Chemicals, Inc.), Olfin (registered trademark) 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 (trade name, Nissin Chemical Industry Co., Ltd.), Acetylenol (registered trademark) E00, E00P, E40, E100 (trade name, Kawaken Fine Chemicals Co., Ltd.), and the like.

[0063] As the fluorine-based surfactant, commercially available products can be used, such as Megafac (registered trademark) F-479 (trade name, DIC Corporation) and BYK-340 (trade name, BYK Corporation).

[0064] The silicone surfactant is not particularly limited, but polysiloxane compounds can be used. The polysiloxane compound is not particularly limited, but for example, polyether-modified organosiloxane can be used. Commercially available polyether-modified organosiloxanes include, for example, BYK-302, 306, 307, 333, 341, 345, 346, 347, 348 (trade name, BYK Co.), KF-351A, 352A, 353, 354L, 355A, 615A, 945, 640, 642, 643, 6020, 6011, 6012, 6015, 6017, and X-22-4515 (trade name, Shin-Etsu Chemical Co., Ltd.).

[0065] Examples of anionic surfactants include higher fatty acid salts, soaps, α-sulfofatty acid methyl ester salts, alkylbenzene sulfonates, alkyl sulfate salts, alkyl ether sulfate salts, monoalkyl phosphate salts, α-olefin sulfonates, alkylnaphthalene sulfonates, naphthalene sulfonates, alkanesulfonates, polyoxyethylene alkyl ether sulfates, sulfosuccinates, and polyoxyalkylene glycol alkyl ether phosphate salts.

[0066] Examples of the cationic surfactant include quaternary ammonium salt compounds such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkyldimethylbenzylammonium salts, and amine salt compounds such as N-methylbishydroxyethylamine fatty acid ester hydrochloride.

[0067] Examples of amphoteric surfactants include, but are not limited to, amino acid compounds such as alkylamino fatty acid salts.

[0068] The above-mentioned surfactants may be used alone or in combination of two or more kinds.

[0069] 2) Organic solvents An organic solvent may be added to the ink composition. By adding an organic solvent, it is possible to control physical properties such as viscosity and surface tension, and behavior such as drying and penetration when applied to a recording medium. Examples of organic solvents include 2-pyrrolidones, 1,2-alkanediols, polyhydric alcohols, and glycol ethers. These can be used alone or in combination of two or more.

[0070] The 2-pyrrolidones refer to compounds having a 2-pyrrolidone skeleton. Examples of the 2-pyrrolidones that can be used include unsubstituted 2-pyrrolidone, as well as compounds having a substituent such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and N-vinyl-2-pyrrolidone. The substituent in the 2-pyrrolidone skeleton is preferably an organic group such as a saturated or unsaturated hydrocarbon group having 1 to 5 carbon atoms. Among these, it is more preferable to use 2-pyrrolidone, which is excellent in terms of the storage stability of the ink and the effect of suppressing the occurrence of aggregates.

[0071] When 2-pyrrolidones are added, the content is preferably 0.9% by mass or more and 8.1% by mass or less, based on the total mass of the ink. More preferably, it is 1.0% by mass or more and 8.0% by mass or less. By setting the content of 2-pyrrolidones within the above range, it is possible to suppress an increase in the viscosity of the ink and improve the ejection stability of the ink.

[0072] Examples of 1,2-alkanediols include 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and 1,2-octanediol. 1,2-alkanediols are excellent in increasing the wettability of the ink to the recording medium and wetting it uniformly. Therefore, it is possible to produce printed matter with reduced bleeding. When 1,2-alkanediols are added, the content is preferably 1% by mass or more and 20% by mass or less with respect to the total mass of the ink.

[0073] Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,3-pentanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-2,4-pentanediol, and glycerin. By adding polyhydric alcohols to the ink, it is possible to suppress the ink from drying and solidifying in the ejection nozzle of the inkjet head, thereby reducing clogging of the ejection nozzle and ejection failure. When polyhydric alcohols are added, the content is preferably 2% by mass or more and 20% by mass or less with respect to the total mass of the ink. Polyhydric alcohols that are solid at 20° C. have the same effect as the polyhydric alcohols in organic solvents and may be used in the same manner. Examples of polyhydric alcohols that are solid at 20° C. include trimethylolpropane.

[0074] Examples of glycol ethers include alkylene glycol monoethers and alkylene glycol diethers.

[0075] Examples of alkylene glycol monoethers 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, and dipropylene glycol monoethyl ether.

[0076] Examples of alkylene glycol diethers 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 ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, and dipropylene glycol diethyl ether.

[0077] By adding glycol ethers to the ink, it is possible to adjust the wettability and permeation speed of the ink onto a recording medium, thereby enabling clear formation of images, patterns, etc. When glycol ethers are added, the content is preferably 0.05% by mass or more and 6% by mass or less relative to the total mass of the ink.

[0078] The organic solvents described above may be used in combination. In this case, the total content of the organic solvents in the ink is 0.2% by mass or more and 30.0% by mass or less, preferably 0.4% by mass or more and 20.0% by mass or less, and more preferably 0.5% by mass or more and 15.0% by mass or less, based on the total mass of the ink. By setting the total content of the organic solvents within the above range, it is possible to suppress the increase in the viscosity of the ink, adjust the behavior (penetration and wetting spread) when the ink is applied to a recording medium, and improve the ejection stability during printing.

[0079] 3)Other The ink may contain various additives such as a pH adjuster, a preservative, a fungicide, and an antioxidant as other components.

[0080] Examples of pH adjusters include ureas, morpholines, piperazines, and aminoalcohols. Examples of ureas include urea, ethyleneurea, tetramethylurea, thiourea, 1,3-dimethyl-2-imidazolidinone, and betaines (trimethylglycine, triethylglycine, tripropylglycine, triisopropylglycine, N,N,N-trimethylalanine, N,N,N-triethylalanine, N,N,N-triisopropylalanine, N,N,N-trimethylmethylalanine, carnitine, acetylcarnitine, and the like). By containing a pH adjuster, for example, it is possible to suppress or promote the elution of impurities from the member forming the ink flow path, and to adjust the cleaning properties of the ink composition. The above-mentioned alkanolamine also functions as a pH adjuster.

[0081] Examples of the fungicide / preservative include Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel IB, and Proxel TN. By including the fungicide / preservative, the growth of mold and bacteria can be inhibited, and the storage stability of the ink composition can be improved.

[0082] 1.1.6. Properties, preparation, etc. of ink composition The surface tension of the ink composition at 25°C is preferably 10 mN / m or more and 40 mN / m or less. More preferably, it is 20 mN / m or more and 40 mN / m or less, and even more preferably, it is 20 mN / m or more and 35 mN / m or less. By setting the surface tension at 25°C within the above range, the ejection stability of the ink composition from the ejection nozzle is improved when used in the inkjet method. The surface tension of the ink composition can be measured, for example, by using an automatic surface tensiometer CBVP-Z (Kyowa Interface Science Co., Ltd.) in an environment of 25°C by immersing a part of a platinum plate in the ink composition.

[0083] When the ink composition is used by an inkjet method, the viscosity of the ink composition at 20°C is preferably 2 mPa·s (milliPascal seconds) or more and 15 mPa·s or less. More preferably, it is 2 mPa·s or more and 10 mPa·s or less, and even more preferably, it is 3 mPa·s or more and 6 mPa·s or less. The viscosity of the ink composition can be measured, for example, using a viscoelasticity tester MCR-300 (Pysica). Specifically, the viscosity is measured by adjusting the temperature of the ink composition to 20°C, increasing the shear rate from 10 to 1000, and reading the viscosity when the shear rate is 200.

[0084] The ink composition of the present embodiment can be prepared by mixing the above-mentioned components in any order, and removing impurities and foreign matter by filtering or the like as necessary. The method for mixing the components is to add the materials in order to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer, and stir and mix them. The filtering method includes centrifugal filtering, filter filtering, and the like.

[0085] 1.2. Other characteristics of the ink composition The ink composition may be characterized in that it contains water, a first dye, and a second dye, and the content of the first dye is 0.5 mass% or more based on the total amount. With such an ink composition, graininess is suppressed, and an image having good ozone fastness and a neutral hue can be formed.

[0086] The ink composition may be an ink composition contained in an ink container described later. In this case, the ink composition contains water and a first dye, the content of the first dye is 0.5 mass % or more based on the total amount of the ink composition, and the total surface area of ​​the metal with which the ink composition comes into contact in the ink container is A (cm 2 ), and the volume of the ink composition contained in the ink container is V (cm 3 ), the ratio (A / V) is 1.7 or less. In this way, graininess is suppressed, and an image having good ozone fastness can be formed, and storage stability can also be improved.

[0087] 1.3.Ink container An example of an ink container according to this embodiment will be described below with reference to the drawings. The ink container according to this embodiment is a bottle for replenishing an ink composition to an ink tank of an inkjet printer (recording device) that records (prints) an image or the like on a medium by ejecting ink onto the medium. In the following description, the ink composition may be simply referred to as ink.

[0088] As shown in FIG. 1, the recording device 21 includes a housing 22 having a rectangular parallelepiped shape with the left-right direction as the longitudinal direction. FIG. 1 shows a simplified view of the inside of the housing 22 of the recording device 21 in a see-through state. A support base 23 with the left-right direction as the longitudinal direction is provided in a lower portion near the rear of the housing 22, with its upper surface aligned substantially horizontally. Paper P, which is an example of a medium, is supported on the upper surface of the support base 23 and transported forward in the transport direction. A guide shaft 24 extending in the left-right direction is installed above the support base 23 in the housing 22, and a carriage 26 having a recording head 25 on its lower surface that ejects ink is supported on the guide shaft 24. That is, the carriage 26 is supported so as to be freely movable back and forth in the left-right direction with respect to the guide shaft 24, with the guide shaft 24 inserted through a support hole 27 penetrating in the left-right direction.

[0089] A drive pulley 28 and a driven pulley 29 are rotatably supported at positions near both ends of the guide shaft 24 within the housing 22. An output shaft of a carriage motor 30 is connected to the drive pulley 28, and an endless timing belt 31, a part of which is connected to the carriage 26, is wound between the drive pulley 28 and the driven pulley 29. When the carriage 26 is driven by the carriage motor 30 and guided by the guide shaft 24 via the timing belt 31 to reciprocate along the left-right direction which is the scanning direction for the paper P, ink is ejected from the recording head 25 on the underside of the carriage 26 onto the paper P which is transported forward on the support base 23.

[0090] 1, a rectangular discharge port 32 is opened at a position on the front side of the housing 22 in front of the support base 23, for discharging paper P, on which recording has been performed by ejecting ink from the recording head 25 when the paper P is transported on the support base 23 inside the housing 22, to the front side. A rectangular plate-shaped discharge tray 33 capable of supporting paper P discharged from inside the housing 22 is provided at the discharge port 32 so as to be freely retractable forward, which is the discharge direction. A paper feed cassette 34 capable of accommodating multiple sheets of paper P used for recording in a stacked state is attached below the discharge tray 33 inside the discharge port 32 so as to be freely insertable and removable in the front-rear direction.

[0091] 1, an opening / closing door 35 having a rectangular front and top surface and a right-angled triangular right side surface is provided on the front of the housing 22 at a position closer to the left-right end than the outlet 32 ​​(the right end in FIG. 1), and can be opened and closed in the front-rear direction around a rotation shaft 36 provided at the bottom of the opening / closing door 35 and extending in the left-right direction. A window 37 made of a rectangular transparent member is formed on the front of the opening / closing door 35, so that the user can view the inside of the housing 22 (particularly the back side of the front surface of the opening / closing door 35) when the opening / closing door 35 is closed.

[0092] An ink supply unit 40 that supplies ink to the recording head 25 is housed inside the housing 22 of the recording device 21 at a position behind the opening and closing door 35, i.e., at a position near the front and near an end (in this case, near the right end). The ink supply unit 40 is a structure that includes multiple (five in this embodiment) ink tanks 41-45 and can be handled as a unit, and as will be described later, each of the ink tanks 41-45 can be replenished with ink.

[0093] As shown in FIG. 2 and FIG. 3, the ink supply unit 40 includes five ink tanks 41-45 in a deformed box shape elongated in the front-rear direction, five ink supply tubes 46 drawn out from the rear side of each ink tank 41-45, and a rectangular parallelepiped ink supply adapter 47 to which the ink tanks 41-45 are assembled together. The ink supply adapter 47 is assembled to a step portion 48 cut out and formed in the upper front half of all the ink tanks 41-45 when all the ink tanks 41-45 are arranged side by side with the thickness direction being the left-right direction, thereby being integrated with the ink tanks 41-45. As shown in FIG. 1, the ink supply tubes 46 drawn out from the ink tanks 41-45 are connected to an ink flow path (not shown) formed in the carriage 26, and are connected to the recording head 25 through the ink flow path. The ink supply adapter 47 may be a part of the housing 22 that covers the ink tanks 41-45, or may be formed integrally with the ink tanks 41-45.

[0094] As shown in Figs. 4 and 5, the ink tanks 41 to 45 each have an ink storage chamber 49 capable of storing an ink composition IK therein. In this embodiment, the ink storage chamber 49 of the ink tank 41 located at the right end in the horizontal arrangement direction stores black ink. The ink storage chambers 49 of the other ink tanks 42 to 45 arranged to the left of the right end ink tank 41 in the horizontal arrangement direction store inks of colors other than black (cyan, magenta, yellow, etc.). In addition, the front wall of the ink tanks 41 to 45, which is visible through the window 37 on the front surface of the housing 22, is provided with a visual recognition portion 50 made of a transparent resin that allows the liquid level of the ink composition IK in the ink storage chamber 49 to be visually recognized. The visible portion 50 is marked with an upper limit mark 51 indicating the upper limit of the liquid level of the ink composition IK stored in the ink storage chamber 49 (an example of an indication of the amount of ink that can be injected without the ink overflowing from the ink inlet 53) and a lower limit mark 52 indicating the lower limit (for example, an indication to encourage the refilling of ink).

[0095] As shown in FIG. 4, an ink inlet 53 that allows ink to flow from the outside into the ink storage chamber 49 is provided above the horizontal portion of the step portion 48 in the ink tanks 41-45. The ink inlet 53 includes a needle 56 that has flow paths 54, 55 that communicate the inside and outside of the ink storage chamber 49 and extends vertically upward. The flow paths 54, 55 of the needle 56 are composed of two flow paths 54, 55 arranged side by side in a radial direction with the needle 56 as a center, and one of the two flow paths 54, 55 (the flow path 54 on the right side in FIG. 4) has a lower end opening and a larger cross-sectional area than the other flow path 55 (the flow path 54 on the left side in FIG. 4). A remaining amount sensor 57 for detecting the remaining amount of the ink composition IK in the ink storage chamber 49 is provided at a lower portion near the rear inside the ink storage chamber 49. The remaining amount sensor 57 does not have to be provided.

[0096] 2 to 5, the ink supply adapter 47 has an upper surface 58 which is a horizontal surface along a direction perpendicular (intersecting) to the direction in which the needle 56 extends, and a through hole 60 which penetrates vertically to a lower surface 59 is formed in the upper surface 58 as an ink inlet forming portion. The through hole 60 is made up of a circular ink inlet 53 in which the needle 56 is located at the center, and a pair of rectangular hole portions connected to the front and rear of the ink inlet 53, and the lower opening is closed by the horizontal portion of the stepped portion 48 in the ink tanks 41 to 45 from which the needle 56 protrudes upward.

[0097] Therefore, in the through hole 60, a pair of front and rear rectangular hole portions with their lower openings blocked form a pair of front and rear recesses 61 that open to the upper side, which is the direction in which the needle 56 extends, recessed vertically downward in the depth direction so as to be point symmetrical about the ink inlet 53. That is, in the ink supply adapter 47 integrated with the ink tanks 41 to 45, a plurality of recesses 61 (two paired front and rear in this case) that are point symmetrical about the ink inlet 53 are formed in the area outside the ink inlet 53 including the needle 56. In this case, the tip of the needle 56 that is located at the center of the circular hole-shaped ink inlet 53 is located closer to the ink storage chamber 49 than the upper surface 58 of the ink supply adapter 47 that is the opening edge of the through hole 60 including the ink inlet 53 and the recesses 61. That is, an upper surface 58 of the ink supply adapter 47 extends in a direction intersecting the extension direction of the needle 56 at a position outside the tip of the needle 56 in the extension direction of the needle 56. On the other hand, a lower surface 59 of the ink supply adapter 47 functions as a tank engaging portion that collectively engages from above the multiple ink tanks 41-45 arranged side by side in the left-right direction.

[0098] In addition, the peripheral portion of the upper opening edge of each through hole 60 in the upper surface 58 of the ink supply adapter 47 is colored in a specific color. That is, it is colored in the same color as the color of the ink stored in the ink storage chamber 49 of the ink tank 41 to 45 into which the ink flows in through the ink inlet 53 of the through hole 60. In this respect, the peripheral portion of the upper opening edge of each through hole 60 in the ink supply adapter 47 functions as a first portion that shows to the outside information related to the ink stored inside the ink tank 41 to 45 whose ink inlet 53 of the through hole 60 communicates with the ink storage chamber 49. Incidentally, the ink stored in the ink tank 41 to 45 is not particularly limited, but if the ink tank supplied from the ink container containing the ink composition of this embodiment is the ink tank 41, black or gray ink will be stored therein, so that the peripheral portion of the upper opening of the through hole 60 where the ink inlet 53 communicating with the ink storage chamber 49 of the ink tank 41 is located is colored black or gray.

[0099] Further, on the inner surface of the recess 61 (specifically, the inner surface along the vertical direction), a first uneven portion (first key structure portion) 62 having a characteristic uneven shape in the horizontal direction is provided at a position closer to the bottom surface side (i.e., the horizontal portion side of the step portion 48) than the upper opening edge of the recess 61, so as to extend along the depth direction of the recess 61 (in other words, the direction of the central axis of the ink inlet 53). As shown in Figs. 2 and 3, the first uneven portion 62 is provided for each of the ink inlets 53 of the ink tanks 41 to 45, which are multiple (five in this embodiment). Therefore, in the ink supply adapter 47, the rectangular recess 61 in each through hole 60 formed at a position corresponding to each of the ink tanks 41 to 45 in the vertical direction has a first uneven portion 62 formed therein that is different from the first uneven portion 62 provided on the inner surface of the recess 61 of each of the other through holes 60 for each through hole 60. That is, these first uneven portions 62 function as an identification portion that enables identification of an ink accommodating body 63 (see FIG. 6, etc.) having an ink outlet 65 (see FIG. 6, etc.) that is connected to an ink inlet 53 in the through hole 60 in which the first uneven portions 62 are formed. Note that "a position that is closer to the bottom surface than the upper opening edge of the recess 61" means that it is sufficient that the position is slightly recessed from the opening edge toward the bottom surface.

[0100] Next, the ink container 63 will be described as an ink supply container that constitutes an ink supply system together with the ink tanks 41 to 45 and supplies ink to the ink tanks 41 to 45 when the remaining amount of ink is low. The ink container 63 contains the ink composition described above.

[0101] 6 to 8, the ink container 63 includes a cylindrical container main body 64 as a main body thereof, an ink outlet forming part 66 provided at the tip of the container main body 64 and having an ink outlet 65 formed at the tip to allow ink to flow out of the ink container 63, and a container additional part 67 added to the ink outlet forming part 66 so as to surround the ink outlet 65. The ink outlet 65 of the ink outlet forming part 66, including the surrounding container additional part 67, is covered by a bottomed cylindrical cap 68, so that it is hidden from the outside during storage of the ink container 63. That is, a male screw part 69 is formed on the outer peripheral surface of the cylindrical lower end of the container additional part 67, while a female screw part (not shown) is formed on the inner peripheral surface of the cap 68, and the cap 68 is attached to the tip of the ink container 63 so as to cover the ink outlet 65 by screwing the male screw part 69 of the container additional part 67 into the female screw part of the cap 68.

[0102] The entire outer surface of the container additional portion 67 is colored in a specific color. That is, the container additional portion 67 is colored in the same color as the color of the ink contained in the container main body portion 64 to which the container additional portion 67 is added. Incidentally, the outer surface of the container additional portion 67 in the ink container 63 containing black or gray ink is colored black or gray. In addition, a plurality of (four in this embodiment) protrusions 70 are formed at equal angular intervals (90 degree intervals, for example) on the outer circumferential surfaces of the base ends of the container main body portion 64 and the cap 68. Incidentally, these protrusions 70 are formed to prevent the ink container 63, which is cylindrical, from rolling. Furthermore, for example, the container main body portion 64 of the ink container 63 containing black ink may be formed thicker than the container main body portion 64 of the ink container 63 containing ink of other colors. In that case, the ink outlet forming portion 66 may have the same thickness and shape for black ink and ink of other colors.

[0103] 6 to 8, a convex portion 71 is formed in an area that is outside the ink outlet 65 in the radial direction centered on the ink outlet 65 above the cylindrical lower end where the male screw portion 69 is formed on the outer circumferential surface of the container additional portion 67. The convex portion 71 functions as a second fitting portion that can be fitted with the concave portion 61 on the upper surface 58 of the ink supply adapter 47 as the first fitting portion when the tip of the needle 56 on the ink inlet 53 side is inserted into the ink outlet 65. The convex portion 71 is provided to form a pair sandwiching the ink outlet 65 from the front and rear, similar to the pair of concave portions 61 that sandwich the ink inlet 53 from the front and rear. As shown in FIG. 6 and FIG. 7, the convex portion 71 is formed inward from the outer circumferential surface of the container main body portion 64 in the ink accommodating body 63 in the radial direction centered on the ink outlet 65.

[0104] 6 and 9, a second uneven portion (second key structure portion) 72 that can engage with a first uneven portion (first key structure portion) 62 formed on the inner surface of the recess 61 of the ink supply adapter 47 is formed on the outer surface of each protrusion 71 (both left and right sides in FIGS. 6 and 9). The second uneven portion 72 is provided so as to extend along the protruding direction of the protrusion 71 (in other words, the direction of the central axis of the ink outlet 65), and when the protrusion 71 is fitted into the recess 61 and the second uneven portion 72 is engaged with the first uneven portion 62, the ink outlet 65 of the ink accommodating body 63 is connected to the ink inlet 53 on the ink tank 41-45 side.

[0105] Further, between the cylindrical lower end of the container additional portion 67 where the male thread portion 69 is formed and the convex portion 71 where the second uneven portion 72 is formed, a positioning portion 73 having a planar shape perpendicular to (intersecting with) the central axis of the ink outlet 65 is provided so as to be located radially outward of the ink outlet 65 when the ink outlet 65 is viewed in the direction of its central axis. That is, this positioning portion 73 constitutes a part of the outer surface of the container additional portion 67 which is a part of the outer surface of the ink accommodating body 63, and is provided at a position closer to the container main body portion 64 than the tip of the convex portion 71 in the direction of the central axis of the ink outlet 65. And, since this positioning portion 73 is provided in the container additional portion 67 which is added to the ink outlet forming portion 66 in the ink accommodating body 63, it can be said that the positioning portion 73 is a separate member from the ink outlet forming portion 66 and is provided outside the ink outlet forming portion 66.

[0106] 9, a valve 74 made of an elastic member such as a silicon membrane that seals the ink outlet 65 in an openable and closable manner is provided in the ink outlet 65 formed in the ink outlet forming portion 66. The valve 74 is provided at a position where the positioning portion 73 is closer to the container body portion 64 in the direction of the central axis of the ink outlet 65 (see, for example, FIG. 14). The valve 74 is provided with a plurality of slits 75 (three in this embodiment) that intersect at equal angular intervals (120 degree intervals, for example) with the center as the intersection point, and is configured to open when the slits 75 are pushed from the outside to the inside of the ink outlet 65. That is, when the tip of the needle 56 on the ink inlet 53 side is inserted into the ink outlet 65, the normally closed valve 74 is pushed inward by the tip of the needle 56 to open the valve.

[0107] At that time, the positioning portion 73 comes into contact with the upper surface 58 of the ink refill adapter 47, in which the through hole 60 including the ink inlet 53 and the recess 61 is formed, on the radial outer side of the ink outlet 65, and positions the valve 74 with respect to the ink tanks 41-45 in the central axial direction of the ink outlet 65. In this regard, the upper surface 58 of the ink refill adapter 47 is part of the ink tanks 41-45 side against which the positioning portion 73 of the ink accommodating body 63 comes into contact when the valve 74 of the ink outlet 65 of the ink accommodating body 63 is opened to refill the ink tanks 41-45 with ink, and functions as a receiving surface that receives the planar positioning portion 73.

[0108] 10 and 11, the container body 64 of the ink container 63 is a bottle-shaped member having an ink storage chamber 76 capable of storing an ink composition IK therein, and a male screw portion 78 is formed on the outer circumferential surface of a neck portion 77 at the upper end of the container body 64. On the other hand, the ink outlet forming portion 66 provided at the upper end of the container body 64 has a large diameter portion 79 located on the outer circumferential side of the neck portion 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. The ink outlet forming portion 66 is attached to the upper end of the container body 64 by screwing a female screw portion 82 formed on the inner circumferential surface of the large diameter portion 79 into the male screw portion 78 formed on the outer circumferential surface of the neck portion 77 of the container body 64.

[0109] Furthermore, the container attachment portion 67, which is attached to the ink outlet forming portion 66 of the ink accommodating body 63 so as to surround the ink outlet 65, has a cylindrical lower end portion with a male thread portion 69 formed on its outer circumferential surface, which constitutes a joint portion 83 whose lower end surface is joined to the upper end surface of the large diameter portion 79 of the ink outlet forming portion 66. This joint portion 83 is joined to the large diameter portion 79 of the ink outlet forming portion 66 with opposing surface areas of its inner circumferential surface in the front-to-rear direction being in surface contact with the front outer surface and the rear outer surface of the intermediate portion 81 of the ink outlet forming portion 66.

[0110] Next, the operation of the ink supply system configured as above will be described below, focusing on the operation when the ink container 63 is used to supply ink to the ink tanks 41 to 45 of the ink supply unit 40.

[0111] As a premise, as shown in Fig. 2, the ink level in the black ink ink tank 41 located at the rightmost position among the ink tanks 41 to 45 arranged side by side has dropped to the height of the lower limit mark 52 marked at the bottom of the visual confirmation portion 50, and therefore the following description will be given of a case where ink is refilled into this ink tank 41. It is also assumed that the ink container 63 used for ink refilling contains a sufficient amount of black ink, and that the cap 68 has been removed from the ink container 63 in advance. It is also assumed that the shape of the second uneven portion 72 formed on the outer surface of the convex portion 71 of the ink container 63 matches the shape of the first uneven portion 62 formed on the inner surface of the concave portion 61 located in front of and behind the ink inlet 53 to the ink tank 41, and that the convex portion 71 can be engaged with the concave portion 61 when inserted therein.

[0112] When refilling the ink tank 41 with ink, the user first rotates the opening / closing door 35 of the housing 22 from the closed state shown in Fig. 1 forward about the rotation shaft 36 to open it. Then, in the ink supply unit 40, the upper surface 58 of the ink refill adapter 47, in which the ink inlets 53 to the ink tanks 41 to 45 are formed, is exposed to the outside of the housing 22, and the user can connect the ink outlet 65 of the ink accommodating body 63 to the desired ink inlet 53 from above.

[0113] Therefore, as shown in FIG. 12 and FIG. 13, the user turns the ink container 63 containing the ink composition to be used for ink refill upside down and holds it so that the ink outlet 65 is located above the rightmost through hole 60 of the ink refill adapter 47. That is, the central axis of the ink outlet 65 of the ink container 63 is aligned with the central axis of the ink inlet 53 of the ink tank 41 to be refilled. At this time, the user compares the color (second part) of the container additional part 67 of the ink container 63 held in the hand with the color (first part) of the upper opening edge periphery of the through hole 60 in which the ink inlet 53 of the ink tank 41 to be refilled at that time is provided. Then, if the colors are the same (in this case, both are black), the user confirms that the ink container 63 held in the hand is suitable for the current ink refill and proceeds to the subsequent work of ink refill.

[0114] 12 and 13, the ink container 63 is lowered, and the protrusion 71 of the ink container 63 is inserted into the recess 61 of the ink refill adapter 47 that is integral with the ink tank 41. Then, the insertion of the protrusion 71 into the recess 61 ensures that the central axis of the ink outlet 65 coincides with the central axis of the ink inlet 53. In this case, the recess 61 is located point-symmetrically with respect to the needle 56 that is the center of the ink inlet 53, so that the protrusion 71 can be inserted into any recess 61. Therefore, the user can easily insert the protrusion 71 into the recess 61 without having to rotate the ink container 63 around the central axis of the ink outlet 65 many times to check the appropriate positional relationship between the recess 61 and the protrusion 71.

[0115] However, at this point, the convex portion 71 is only slightly inserted into the concave portion 61, and the tip of the needle 56 located at the center of the ink inlet 53 is also inserted into the opening of the ink outlet 65 protruding slightly from the tip of the convex portion 71, but has not yet reached the valve 74 located deep inside the ink outlet 65. The reason for this is that, as shown in Fig. 13, the distance L2 between the tip of the convex portion 71 and the valve 74 in the ink outlet 65 is longer than the distance L1 between the top surface 58 of the ink supply adapter 47, where the edge of the opening of the concave portion 61 is located, and the upper end of the first concave portion 62 in the concave portion 61. Therefore, when the convex portion 71 is further inserted downward in the depth direction of the concave portion 61 from this state, the second concave portion 72 on the outer surface of the convex portion 71 engages with the first concave portion 62 on the inner surface of the concave portion 61. Then, while maintaining this engaged state, when the convex portion 71 is further inserted in the depth direction of the concave portion 61 toward the bottom side, the tip of the needle 56 of the ink inlet 53 reaches the position of the valve 74 of the ink outlet 65, opening the valve 74.

[0116] That is, as shown in FIG. 14 and FIG. 15, the tip of the needle 56 pushes and widens the slit 75 from below to above (i.e., from the outside to the inside of the ink outlet 65) against the valve 74, thereby opening the valve 74. As a result, the ink outlet 65 of the ink accommodation body 63 and the needle 56 of the ink inlet 53 of the ink tank 41 are connected, and the ink composition is replenished from the ink accommodation body 63 to the ink tank 41. At this time, of the two flow paths 54, 55 of the needle 56 of the ink inlet 53, one of the flow paths whose tip opening first touches the ink flow path that flows the ink by opening the valve 74 and flowing out of the ink outlet 65 functions as an ink flow path that flows the ink, and the other flow path functions as an air flow path that flows the air. For example, if a user tries to connect the ink outlet 65 to the ink inlet 53 while tilting the ink accommodation body 63, the flow path that becomes the ink flow path among the two flow paths 54, 55 will also change depending on the tilt direction.

[0117] In addition, if the second uneven portion 72 does not engage with the first uneven portion 62 after the convex portion 71 is inserted into the concave portion 61, the user can recognize at that point that he or she is about to insert an ink container 63 of a color other than black by mistake. In this case, if the upper end of the first uneven portion 62 is configured to be located at the same height as the opening edge of the concave portion 61, not only will the engagement of the second uneven portion 72 with the first uneven portion 62 be rejected, but the insertion of the convex portion 71 into the concave portion 61 will also be rejected, so the user may try to insert the convex portion 71 into the concave portion 61 many times, wasting unnecessary work time. In this regard, in the present embodiment, since the height of the first uneven portion 62 is lower than the opening edge of the concave portion 61, the convex portion 71 is easily guided toward the bottom side in the depth direction of the concave portion 61 when inserted into the concave portion 61, and unnecessary prolongation of the work time is also suppressed.

[0118] 14, 16 and 17, when the needle 56 of the ink inlet 53 on the ink tank 41 side opens the valve 74 in the ink outlet 65 of the ink accommodating body 63, the positioning portion 73 of the ink accommodating body 63 abuts against the upper surface 58 of the ink refill adapter 47 which is part of the ink tank 41 side. That is, due to the abutment of the positioning portion 73 with the upper surface 58 of the ink refill adapter 47, the ink accommodating body 63 is opened with the valve 74 positioned in the direction of the central axis of the ink outlet 65 with respect to the needle 56 on the ink tank 41 side.

[0119] In addition, since the positioning portion 73 is located radially outward of the ink outlet 65, the ink accommodating body 63 is stably maintained in a position in which the ink outlet 65 is connected to the ink inlet 53. In addition, as shown in Figures 14 and 15, when the positioning portion 73 of the ink accommodating body 63 abuts against the upper surface 58 of the ink refill adapter 47, a gap is present between the bottom surface of the ink inlet 53 where the base end of the needle 56 of the ink inlet 53 is located and the tip of the ink outlet 65 of the ink accommodating body 63. Therefore, although ink is likely to accumulate on the bottom surface where the base end of the needle 56 of the ink inlet 53 is located, it is possible to prevent the accumulated ink from adhering to the tip of the ink outlet 65 and soiling the ink accommodating body 63.

[0120] 14 and 16, when the ink replenishment from the ink accommodation body 63 to the ink tank 41 is completed, if the ink level in the ink tank 41 is still lower than the upper limit mark 51 of the visible portion 50, the same black ink accommodation body 63 may be used to further replenish the ink up to the upper limit mark 51. Note that the ink replenishment operation as described above is also performed in the same way for the ink tanks 42 to 45 of colors other than the ink tank 41 containing the ink composition (black or gray ink composition).

[0121] In the ink container 63 described above, all of the portions that may come into contact with the ink composition are made of a polymer compound such as polyolefin, etc. In other words, the ink container has a structure in which the portions that come into contact with the ink composition do not contain metal.

[0122] Therefore, the ink container 63 is designed to have a total surface area of ​​metal that the ink composition contacts in the ink container 63 of A (cm 2 ), and the volume of the ink composition contained in the ink container 63 is V (cm 3 ), the ratio (A / V) must be 1.7 or less, and the ratio (A / V) is 0.0.

[0123] In the ink container 63, the ratio (A / V) is 0.0, but the ink container may have a portion where the ink composition comes into contact with metal, so long as the ratio (A / V) is 1.7 or less. Such a portion may be, for example, a spring, which may be made of an aluminum alloy or stainless steel. Moreover, the ratio (A / V) is more preferably 1.0 or less, even more preferably 0.5 or less, and even more preferably 0.2 or less.

[0124] As a result of investigation, the inventors have found that the ink composition container affects the storage stability of the ink composition. They presume that one of the causes of this effect is contact between the ink composition and metal in the container. It is believed that by setting the ink container ratio (A / V) to 1.7 or less, the first dye in the ink composition comes into contact with metal less frequently, thereby suppressing deterioration of the first dye when the ink composition is stored in the ink container.

[0125] Moreover, when the ratio (A / V) is 0.0 as in the ink container 63 described above, the storage stability of the first dye can be further improved, as will be demonstrated by the examples described later.

[0126] In addition, although an example of a bottle-shaped ink container with a relatively high strength has been described above, the ink container may be one that is easily deformed and made of a film or the like. Examples of the form of such an ink container include a pack and a tube. Even if the ink container is in the form of a pack or a tube, the same effect can be obtained as long as the ratio (A / V) is 1.7 or less.

[0127] On the other hand, in the case of a bottle-type ink container having a relatively high strength, such as the ink container 63 described above, the ink composition is in contact with air when the ink composition is contained in the ink container. With such a structure, the ink composition comes into contact with air during storage. In this case, it is possible to prevent the dye contained in the contained ink composition from being reduced and deteriorated during storage due to the oxidizing effect of oxygen in the air. Note that even if the ink container is in the form of a pack or tube, the ink composition can be stored in a state where it is in contact with air, and in this case, the manufacturer or user stores the ink composition in such a state.

[0128] This ink container allows the first dye in the ink composition to be stored in a state in which it has good color development, and the ink composition contained in this ink container allows the formation of an image with good ozone fastness.

[0129] 2. Examples and Comparative Examples The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are based on mass unless otherwise specified. The following evaluations were performed in an environment with a temperature of 25°C and a relative humidity of 40%, unless otherwise specified.

[0130] 2.1. Preparation of Ink Composition The compositions of the ink compositions of the examples and comparative examples are shown in Tables 1 and 2. The ink compositions were prepared by mixing the components shown in Tables 1 and 2 in any order, mixing for 30 minutes or more, and removing impurities and foreign matter by filtration as necessary. The components were mixed by adding the materials in order to a container equipped with a mechanical stirrer, stirring and mixing. The mixture was then filtered through a filter to obtain the ink compositions of each example (Examples 1 to 20, Comparative Examples 1 to 6). The units of values ​​in Tables 1 and 2 are "% by mass".

[0131] [Table 1]

[0132] [Table 2]

[0133] In Tables 1 and 2, "B-1," "M-1," "M-2," "M-3," "Y-1," and "Y-2" in the dye compound formula column are respectively the above-mentioned "lithium salt of the compound represented by formula (B-1)," "sodium salt of the compound represented by formula (M-1)," "sodium and / or ammonium salt of the compound represented by formula (M-2)," "lithium salt of the compound represented by formula (M-3)," "lithium salt of the compound represented by formula (Y-1)," and "potassium salt of the compound represented by formula (Y-2)."

[0134] In addition, in Tables 1 and 2, "B-2" in the dye compound formula column is "sodium and / or ammonium salt of the compound represented by the following formula (B-2)."

[0135] [ka] (B-2)

[0136] Tables 1 and 2 also show the pH of the ink composition, the solid content of the dye, and the total surface area A (cm 2 ), ink capacity V(cm 3 ), ratio (A / V), and the presence or absence of air in the container. The total surface area of ​​the metal A (cm 2 The example in which the total surface area A (cm 2 In the examples where the total surface area A (cm 2 ) of the metal in Comparative Example 1 is "12.0", "19.0", and "24.0", metal pieces having the respective surface areas were placed in the ink container 63. 2 ) and ink capacity V(cm 3 ) corresponds to the total metal surface area and ink capacity of an ink cartridge, which is an ink container for an inkjet printer such as EP-803A (manufactured by Seiko Epson Corporation). In Example 20, which has "no air" in the container, a flexible polyethylene pack was used, and ink was sealed in such a way that there was no air layer in the pack.

[0137] 2.2. Evaluation method 2.2.1. Storage stability of ink composition The ink container containing the ink composition of each example was left in a thermostatic chamber at 60° C. for 7 days. The rate of change in absorbance (ABS) of the ink composition before and after being left standing was used to evaluate according to the following criteria, and the results are shown in Tables 1 and 2. Note that the absorbance was measured by diluting each ink 1000 times with ultrapure water, and measuring the maximum absorbance of the maximum peak of the ultraviolet-visible absorption spectrum using an ultraviolet-visible spectrophotometer under the following conditions. S: Change rate < 2% A: 2%≦Change rate<3% B: 3%≦Change rate<5% C: 5%≦Change rate<8% D: 8% or less rate of change Equipment: UV-visible spectrophotometer V-770 series (manufactured by JASCO Corporation) Parameter File Metering mode: ABS Measurement range: 800-300nm Data capture interval: 0.5 nm UV / Vis Bandwidth: 2.0nm NIR Bandwidth: 8.0nm UV / Vis response: 0.06sec NIR response: 0.06sec Scanning speed: 400nm / min Light source switching: 340nm Diffraction grating switching: 850nm Light source: D2 / WI Filter switching: Step Correction: Baseline

[0138] 2.2.2.Hue When printing in monochrome with a duty of 50% under the following conditions, * b * The values ​​were judged according to the following criteria, and the results are shown in Tables 1 and 2. Machine: EP-10A (Seiko Epson Corporation), EPSON glossy photo paper Color measurement: i1 (X-rite) S:a * The value is in the range of -2 to +2, and b * The value is between -2 and +2. A: Outside the range of S, and a * The value is between -4 and +4, and b * The value is between -4 and +4. B: Outside the range of A and a * The value is in the range of -7 to +7, and b * The value is between -7 and +7. C:a * value and b * At least one of the values ​​is outside the range -7 to +7.

[0139] 2.2.3.Gas resistance The rate of change in OD (optical density) value of the samples printed and left under the conditions below was judged according to the following criteria, and the results are shown in Tables 1 and 2. Machine: EP-10A (Seiko Epson Corporation), EPSON glossy photo paper Conditions: Ozone concentration 5 ppm x 80 hours S:OD residual rate 85% or more A:OD residual rate 80% to less than 85% B: OD remaining rate: 70% or more and less than 80% C:OD residual rate less than 70%

[0140] 2.2.3.Clogging recovery Each ink composition was supplied to the head of an EP-10A (manufactured by Seiko Epson Corporation), and after confirming that all nozzles were ejecting normally, the ink was left for one week in an environment of 40° C. and 24% humidity. After that, the number of cleanings required until all nozzles were ejecting normally was determined according to the following criteria, and the results are shown in Tables 1 and 2. S: 0 or 1 time A: 2 or 3 times B: 4 or 5 times C: 6 or more times

[0141] 2.3.Evaluation Results The ink containers of the examples each contain an ink composition containing water and a first dye which is a compound represented by formula (B-1) or a salt thereof, the content of which is 0.5 mass% or more relative to the total amount of the ink composition, and the ratio (A / V) is 1.7 or less. The ink containers of the examples each contain an ink composition having good storage stability. In addition, the ink compositions of the examples each form images having good ozone fastness.

[0142] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be appropriately combined.

[0143] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments, or configurations that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0144] The following can be derived from the above-described embodiment and modifications.

[0145] The ink container is An ink container containing an ink composition, The ink composition contains water and a first dye which is a compound represented by the following formula (B-1) or a salt thereof: the content of the first dye in the ink composition is 0.5% by mass or more with respect to the total amount of the ink composition; The total surface area of ​​the metal that the ink composition contacts in the ink container is defined as A (cm 2 ), and the volume of the ink composition contained in the ink container is V (cm 3 ), the ratio (A / V) is 1.7 or less.

[0146] [ka] ...Formula (B-1)

[0147] This ink container allows the first dye in the ink composition to be stored in a state in which it has good color development, and the ink composition contained in this ink container allows the formation of an image with good ozone fastness.

[0148] In the ink container, the ink composition contains a second dye having a maximum absorption wavelength of 500 nm or more and 580 nm or less; The content of the second dye in the ink composition may be 0.2% by mass or more and 2.0% by mass or less with respect to the total amount of the ink composition.

[0149] According to this ink container, the second dye functions as a complementary color to the color of the first dye contained in the contained ink composition, so that the contained ink composition can form an image with a more neutral hue.

[0150] In the ink container, The second dye may be selected from a compound represented by the following formula (M-1) or a salt thereof, and a compound represented by the following formula (M-2) or a salt thereof.

[0151] [ka] ...Formula (M-1)

[0152] [ka] ...Formula (M-2)

[0153] According to this ink container, the second dye functions more effectively as a complementary color to the color of the first dye, so that the ink composition contained therein can form an image with a more neutral hue.

[0154] In the ink container, The ink composition contains a compound represented by formula (M-1) or a salt thereof, and a compound represented by formula (M-2) or a salt thereof, The content of the compound represented by formula (M-1) or a salt thereof in the ink composition may be smaller than the content of the compound represented by formula (M-2) or a salt thereof in the ink composition.

[0155] According to this ink container, it is possible to form an image with a more neutral hue using the ink composition contained therein.

[0156] In the ink container, a third dye having a maximum absorption wavelength of less than 480 nm; The content of the third dye may be 0.2% by mass or more and 2.0% by mass or less with respect to the total amount of the ink composition.

[0157] According to this ink container, it is possible to form an image with a more neutral hue using the ink composition contained therein.

[0158] In the ink container, The ink container, wherein the third dye is a compound represented by the following formula (Y-1) or a salt thereof:

[0159] [ka] Formula (Y-1)

[0160] According to this ink container, it is possible to form an image with a more neutral hue using the ink composition contained therein.

[0161] In the ink container, The total amount of dye solids may be 6.8% by mass or less based on the total amount of the ink composition.

[0162] According to this ink container, it is possible to form an image with a more neutral hue using the ink composition contained therein.

[0163] In the ink container, The ink container may not contain a metal in a portion that comes into contact with the ink composition.

[0164] This ink container can further improve the storage stability of the first dye.

[0165] In the ink container, The ink container may have a structure in which the ink composition is in contact with air when the ink composition is contained therein.

[0166] This ink container can prevent the dye contained in the stored ink composition from being reduced and deteriorated due to the oxidizing effect of oxygen in the air.

[0167] In the ink container, The ink composition further contains an alkanolamine having 3 or more carbon atoms, The content of the alkanolamine and the content of the first dye may satisfy the relationship of the following formula (1). 0.1<(alkanolamine content) / (first dye content)<0.6...(1)

[0168] According to this ink container, it is possible to form an image with a more neutral hue using the ink composition contained therein.

[0169] In the ink container, The ink composition further contains an organic acid, The content of the organic acid and the content of the first dye may satisfy the relationship of the following formula (2). 0.01<(organic acid content) / (first dye content)<0.1 (2)

[0170] According to this ink container, it is possible to form an image with a more neutral hue using the ink composition contained therein.

[0171] The ink composition comprises water, a first dye which is a compound represented by the following formula (B-1) or a salt thereof, A second dye selected from a compound represented by the following formula (M-1) or a salt thereof, and a compound represented by the following formula (M-2) or a salt thereof, Contains The content of the first dye is 0.5% by mass or more based on the total amount.

[0172] [ka] ...Formula (B-1)

[0173] [ka] ...Formula (M-1)

[0174] [ka] ...Formula (M-2)

[0175] This ink composition can form an image with reduced graininess, good ozone fastness, and a neutral hue.

[0176] The ink composition comprises An ink composition contained in an ink container, The ink composition contains water and a first dye which is a compound represented by the following formula (B-1) or a salt thereof: the content of the first dye is 0.5% by mass or more relative to the total amount of the ink composition; The total surface area of ​​the metal that the ink composition contacts in the ink container is defined as A (cm 2 ), and the volume of the ink composition contained in the ink container is V (cm 3 ), the ratio (A / V) is 1.7 or less.

[0177] [ka] ...Formula (B-1)

[0178] This ink composition can form images with reduced graininess and excellent ozone fastness, and can also have good storage stability. [Explanation of symbols]

[0179] 21...recording device, 22...casing, 23...support stand, 24...guide shaft, 25...recording head, 26...carriage, 27...support hole, 28...driving pulley, 29...driven pulley, 30...carriage motor, 31...timing belt, 32...discharge port, 33...discharge tray, 34...paper feed cassette, 35...opening door, 36...rotating shaft, 37...window, 40...ink supply unit, 41-45...ink tank, 46...ink supply tube, 47...ink refill adapter, 48...step, 49...ink storage chamber, 50...visible portion, 51...upper limit mark, 52...lower limit mark, 53...ink inlet, 54, 55...flow path, 56...needle (ink inlet flow path portion ), 57... remaining amount sensor, 58... upper surface (receiving surface), 59... lower surface (tank engagement portion), 60... through hole, 61... recess (first fitting portion), 62... first uneven portion (identification portion), 63... ink container, 64... container main body portion, 65... ink outlet, 66... ​​ink outlet forming portion, 67... container additional portion, 68... cap, 69... male thread portion, 70... projection, 71... convex portion (second fitting portion), 72... second uneven portion, 73... positioning portion, 74... valve, 75... slit, 76... ink storage chamber, 77... neck portion, 78... male thread portion, 79... large diameter portion, 80... small diameter portion, 81... middle portion, 82... female thread portion, 83... joint portion, L1... distance, L2... distance, P... paper, IK... ink composition

Claims

1. An ink container containing an ink composition, The ink composition includes water and a first compound represented by the following formula (B-1) or a salt thereof: A dye, The content of the first dye in the ink composition is 0.5% by mass or more, The total surface area of ​​the metal that the ink composition contacts in the ink container is defined as A (cm 2 )and The amount of the ink composition contained in the ink container is V (cm 3 ) In this case, the value of the ratio (A / V) is 1.7 or less, The ink composition contains a second dye having a maximum absorption wavelength of 500 nm or more and 580 nm or less. Contains The content of the second dye in the ink composition relative to the total amount of the ink composition is 0.2% by mass or more and 2.0% by mass or less, The second dye is a compound represented by the following formula (M-1) or a salt thereof, 2) a compound represented by the formula (I) or a salt thereof; The ink composition contains a compound represented by formula (M-1) or a salt thereof, and M-2) or a salt thereof, The content of the compound represented by formula (M-1) or a salt thereof in the ink composition is than the content of the compound represented by formula (M-2) or a salt thereof in the ink composition. Small ink container. 【Chemistry 1】 ...Formula (B-1) 【Chemistry 2】 ...Formula (M-1) 【Chemistry 3】 ...Formula (M-2)

2. In claim 1, a third dye having a maximum absorption wavelength of less than 480 nm; The content of the third dye is 0.2 mass % or more to 2.0 mass % or less based on the total amount of the ink composition. The ink container has an ink content of less than 10%.

3. In claim 2, The third dye is a compound represented by the following formula (Y-1) or a salt thereof. 。 【Chemistry 4】 Formula (Y-1)

4. In any one of claims 1 to 3, The total amount of dye solids is 6.8% by mass or less based on the total amount of the ink composition. Ink container.

5. In any one of claims 1 to 4, The ink container does not contain metal in a portion that comes into contact with the ink composition. 。

6. In any one of claims 1 to 5, When the ink composition is contained in the ink container, the ink composition is mixed with air. The ink container has a contact structure.

7. In any one of claims 1 to 6, The ink composition further contains an alkanolamine having 3 or more carbon atoms, The content of the alkanolamine and the content of the first dye have a relationship represented by the following formula (1): Fill the ink container. 0.1<(content of alkanolamine) / (content of first dye)<0.6 (1)

8. In any one of claims 1 to 7, The ink composition further contains an organic acid, The content of the organic acid and the content of the first dye satisfy the relationship of the following formula (2). Ink container. 0.01<(content of organic acid) / (content of first dye)<0.1 (2)

9. An ink composition contained in an ink container, The ink composition includes water and a first compound represented by the following formula (B-1) or a salt thereof: A dye, the content of the first dye is 0.5% by mass or more with respect to the total amount of the ink composition; The total surface area of ​​the metal that the ink composition contacts in the ink container is defined as A (cm 2 )and The amount of the ink composition contained in the ink container is V (cm 3 ) In this case, the value of the ratio (A / V) is 1.7 or less, The ink composition contains a second dye having a maximum absorption wavelength of 500 nm or more and 580 nm or less. Contains The content of the second dye in the ink composition relative to the total amount of the ink composition is 0.2% by mass or more and 2.0% by mass or less, The second dye is a compound represented by the following formula (M-1) or a salt thereof, 2) a compound represented by the formula (I) or a salt thereof; The ink composition contains a compound represented by formula (M-1) or a salt thereof, and M-2) or a salt thereof, The content of the compound represented by formula (M-1) or a salt thereof in the ink composition is than the content of the compound represented by formula (M-2) or a salt thereof in the ink composition. Small, ink composition. 【Chemistry 5】 ...Formula (B-1) 【Chemistry 6】 ...Formula (M-1) 【Chemistry 7】 ...Formula (M-2)

Images