Aqueous inkjet ink composition, ink container, and recording method

Abstract

To provide an aqueous inkjet ink composition which includes environmentally considerate carbon black and achieves excellent ejection stability and storage stability.SOLUTION: An inkjet ink composition which is an aqueous ink, the inkjet ink composition containing a pigment and a surfactant, wherein the pigment contains carbon black derived from a vegetable oil or carbon black derived from a recycled raw material, and the surfactant includes a surfactant A having an HLB value of 10 or more and less than 15, and a surfactant B which is an acetylene glycol-based surfactant having an HLB value of 3 or more and less than 10.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a water-based inkjet ink composition, an ink container, and a recording method. [Background technology]

[0002] The inkjet recording method is capable of recording high-resolution images using a relatively simple device, and has been rapidly developing in various fields. In recent years, environmental issues have become a concern, and environmentally friendly inks have been developed. Plant-derived pigments have attracted attention as materials for such inks, and for example, plant-based carbon black, which is produced using binchotan charcoal or bamboo charcoal, is known.

[0003] For example, Patent Document 1 discloses a water-based inkjet ink composition with the aim of providing an environmentally friendly and storage-stable water-based inkjet ink composition, which contains a coloring material of biological origin such as binchotan charcoal or bamboo charcoal, a dispersant of biological origin, and an organic solvent of biological origin, wherein the organic solvent has a solubility parameter based on the Hansen method of 24.0 (cal / cm 3 ) 1 / 2 As described above, an ink-jet ink composition containing a compound having a hydroxyl group is disclosed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-128719 Summary of the Invention [Problem to be solved by the invention]

[0005] However, vegetable charcoal carbon blacks such as binchotan and bamboo charcoal tend to contain many impurities that are difficult to remove, posing problems in terms of dispersion stability and storage stability. Furthermore, vegetable charcoal carbon blacks have relatively large particle sizes that tend to be non-uniform, leaving room for improvement in terms of discharge stability. [Means for solving the problem]

[0006] The inkjet ink composition of the present invention contains a pigment and a surfactant, wherein the pigment contains carbon black derived from vegetable oil or carbon black derived from recycled raw materials, and the surfactant contains surfactant A having an HLB value of 10 or more and less than 15, and surfactant B which is an acetylene glycol-based surfactant having an HLB value of 3 or more and less than 10.

[0007] The ink container of the present invention comprises the above-described water-based ink-jet ink composition and a container containing the water-based ink-jet ink composition.

[0008] The recording method of the present invention comprises a step of ejecting the above-described water-based inkjet ink composition from an inkjet head and depositing it onto a recording medium. [Brief explanation of the drawings]

[0009] [Figure 1] Table 1 shows the composition of each composition used in the examples and the evaluation results thereof. [Figure 2] Table 2 shows the compositions used in the examples and the evaluation results thereof. [Figure 3] Table 3 shows the composition of each composition used in the examples and the evaluation results thereof. [Figure 4] FIG. 1 is a schematic cross-sectional view showing an example of a recording apparatus that can be used in this embodiment. [Figure 5] FIG. 2 is a schematic perspective view showing an example of an ink container that can be used in the present embodiment. [Figure 6] FIG. 10 is a schematic cross-sectional view showing another example of an ink container that can be used in the present embodiment. [Figure 7] FIG. 10 is a schematic perspective view showing another example of a recording apparatus that can be used in the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Below, we will explain in detail an embodiment of the present invention (hereinafter referred to as the "present embodiment"), referring to the drawings as necessary, but the present invention is not limited to this and various modifications are possible within the scope of the gist of the present invention.

[0011] 1. Water-based inkjet ink composition The water-based inkjet ink composition of this embodiment (hereinafter also simply referred to as the "ink composition") contains a pigment containing carbon black derived from vegetable oil or carbon black derived from recycled raw materials, and surfactants including surfactant A having an HLB value of 10 or more but less than 15, and surfactant B which is an acetylene glycol-based surfactant having an HLB value of 3 or more but less than 10, thereby providing a water-based inkjet ink composition with excellent ejection stability and storage stability.

[0012] Carbon black derived from vegetable oil (hereinafter also referred to as "vegetable oil CB") has a manufacturing process similar to that of petroleum carbon black and tends to have superior dispersion stability compared to vegetable charcoal carbon black. However, because the raw material vegetable oil contains various organic substances, the produced vegetable oil CB contains many voids of different sizes and shapes. Furthermore, the structure may contain a mixture of relatively highly hydrophobic (relatively low hydrophilic) and relatively low hydrophobic (relatively high hydrophilic) parts. This is thought to be due in part to the fact that the produced vegetable oil CB is not completely carbonized, resulting in the presence of some vegetable oil impurities in the vegetable oil CB, the presence of various organic substances in the vegetable oil, and the inconsistency of impurities in the vegetable oil CB.

[0013] Air bubbles tend to remain in these voids, and the air bubbles remaining in the vegetable oil CB act as bubble nuclei that grow with the dissolved nitrogen in the ink composition. The air bubbles that grow in this way are thought to separate from the pigment and cause a decrease in ejection stability.

[0014] In particular, bubbles are likely to grow when the dissolved nitrogen concentration in the ink is relatively high. Even if the dissolved nitrogen concentration in the ink is not high at the time of manufacture, if an ink container with poor gas barrier properties is used, air may penetrate and the dissolved nitrogen concentration in the ink may increase over time.

[0015] Carbon black (hereinafter also referred to as "recycled CB") derived from recycled materials obtained by pyrolysis of waste materials such as scrap tires is similar to vegetable oil CB in that, because the raw waste materials contain a variety of components, the resulting recycled CB contains numerous voids of different sizes and shapes, and the structure may contain a mixture of highly and less hydrophilic parts. As a result, like vegetable oil CB, the problem of reduced discharge stability may occur.

[0016] Therefore, in this embodiment, two types of surfactants, surfactant A and surfactant B, are used. This increases the wettability of the voids in the vegetable oil CB or recycled CB, promotes the removal of fine bubbles, and prevents voids from remaining. Specifically, for example, surfactant A, which has an HLB value of 10 or more but less than 15, increases the wettability of the relatively low hydrophobic portions of the vegetable oil CB or recycled CB, while surfactant B, an acetylene glycol-based surfactant with an HLB value of 3 or more but less than 10, increases the wettability of the relatively high hydrophobic portions. This improves the wettability of the entire vegetable oil CB, promotes the removal of bubbles from the vegetable oil CB or recycled CB, and is thought to maintain good discharge stability even when dissolved nitrogen increases over time.

[0017] Components that may be contained in the ink composition according to this embodiment and a production method thereof will be described in detail below.

[0018] 1.1.Pigments The pigment of this embodiment includes carbon black derived from vegetable oil or carbon black derived from recycled materials. These pigments contain various organic substances as raw materials, and therefore contain voids of different sizes and shapes, as well as areas with high and low hydrophilicity. Therefore, it is difficult to remove air bubbles, which can easily lead to ejection failure, making the effects of the present invention particularly pronounced.

[0019] Carbon black derived from vegetable oils includes carbon black obtained by incomplete combustion or pyrolysis of vegetable oils at high temperatures, and carbon black obtained by burning vegetable oils and collecting the smoke produced (lampblack made from vegetable oils).

[0020] The vegetable oil is not particularly limited, but examples thereof include castor oil, rosin oil, coconut oil, castor oil, rapeseed oil, palm oil, and the like.

[0021] The carbon black derived from recycled materials is not particularly limited, but examples thereof include carbon black obtained by similarly incomplete combustion or thermal decomposition of waste materials such as scrap tires.

[0022] Carbon black (recycled CB) derived from recycled materials also reduces the amount of new petroleum-derived ingredients used by using recycled materials, thereby reducing carbon dioxide emissions compared to when new petroleum-derived ingredients are used, making it an environmentally friendly ink.

[0023] These pigments are not particularly limited, but may be, for example, self-dispersing pigments in which hydrophilic groups are introduced onto the pigment particle surfaces by utilizing a chemical reaction. The self-dispersing pigment is a pigment that can be dispersed in an aqueous medium without a dispersant. Examples of such self-dispersing pigments include pigments that have been made dispersible in an aqueous medium by subjecting the pigment to physical and / or chemical surface treatment to introduce a hydrophilic functional group into the pigment via chemical bonding, either directly or via an organic group. The hydrophilic group is preferably an acidic group, such as a carboxyl group, a sulfo group, a phosphorus-containing acid group, etc. The phosphorus-containing acid group may be a phosphate group, a phosphonate group, etc.

[0024] Resin-dispersed pigments are pigments dispersed in an aqueous medium using a resin. The resin adheres or adsorbs to the pigment surface. The resin used may be, for example, a dispersant resin.

[0025] Of these, self-dispersing pigments are preferred. Self-dispersing pigments have hydrophilic groups on their surfaces, which tends to improve the effect of surfactants A and B in removing bubbles from the voids in the carbon black.

[0026] The content of carbon black derived from vegetable oil and carbon black derived from recycled materials is preferably 0.5% by mass or more and 10% by mass or less, more preferably 2.5% by mass or more and 7.5% by mass or less, 3% by mass or more and 5% by mass or less, or 3.5% by mass or more and 4.5% by mass or less, based on the total amount of the ink composition. When the pigment content is within the above range, ejection stability and storage stability tend to be further improved.

[0027] The volume average particle diameter D50 of the secondary particles of the vegetable oil-derived carbon black or recycled raw material-derived carbon black is preferably 30 nm or more and 200 nm or less, 50 nm or more and 150 nm or less, or 75 nm or more and 125 nm or less, and more preferably 80 to 120 nm, 95 to 115 nm, or 100 to 110 nm. When the volume average particle diameter D50 is within the above range, ejection stability and storage stability tend to be further improved.

[0028] In this embodiment, primary particles refer to independent particles that are not aggregated, and secondary particles refer to particles that are dispersed in the ink as a single independent particle. Secondary particles may be, for example, aggregated particles formed by the aggregation of two or more primary particles. Carbon black derived from vegetable oil or carbon black derived from recycled materials tends to take the form of secondary particles, i.e., aggregated particles, and these aggregated particles may have voids between the primary particles. Surfactants A and B easily remove air bubbles trapped in such voids.

[0029] In this embodiment, the volume average particle diameter D50 refers to a volume-average median diameter, and can be measured using, for example, a dynamic light scattering method.

[0030] 1.2.Surfactants The surfactants include surfactant A, which has an HLB value of 10 or more and less than 15, and surfactant B, which is an acetylene glycol-based surfactant, which has an HLB value of 3 or more and less than 10, and may contain other surfactants as necessary.

[0031] The surfactants of this embodiment are preferably surfactant A and surfactant B having HLB values ​​within a specific range. In this embodiment, the HLB (Hydrophile-Lipophile Balance) value is a value proposed by Davis et al. to evaluate the hydrophilicity of a compound, and is a numerical value obtained by the Davis method defined in the literature "JT Davis and EK Rideal, "Interface Phenomena," 2nd ed. Academic Press, New York, 1963," and represents a value calculated by the following formula: The HLB value is a value that evaluates the hydrophilicity of a compound; the larger the HLB value, the higher the hydrophilicity, and the smaller the HLB value, the higher the hydrophobicity. HLB value = 7 + Σ[1] - Σ[2] (In the formula, [1] represents the number of hydrophilic groups, and [2] represents the number of hydrophobic groups.)

[0032] 1.2.1. Surfactant A Surfactant A increases the wettability of the relatively less hydrophobic portions of vegetable oil CB or recycled CB, promotes the removal of air bubbles, and maintains good ejection stability even when a container in which dissolved nitrogen increases over time is used. The HLB value of surfactant A is 10 or more and less than 15, preferably 11 or more and 14.5 or less, and 12 or more and 14 or less. When the HLB value of surfactant A is within the above range, storage stability tends to be further improved.

[0033] The surfactant A is not particularly limited as long as it has an HLB value of 10 or more and less than 15, and examples thereof include silicone surfactants, acetylene glycol surfactants, fluorine surfactants, etc. The surfactant A may be used alone or in combination of two or more types.

[0034] Among these, at least one selected from the group consisting of silicone surfactants and acetylene glycol surfactants is preferred, and acetylene glycol surfactants are more preferred. The use of such surfactants tends to further improve storage stability and ejection stability. In addition, acetylene glycol surfactants are less likely to foam, and because they have a carbon skeleton similar to carbon black, they tend to have high affinity with carbon black and high bubble removal efficiency.

[0035] The acetylene glycol surfactant used as surfactant A is preferably an acetylene glycol surfactant having a polyether-modified group. Examples of the acetylene glycol surfactant used as surfactant A include compounds represented by the same formula (1) as described below, except that m and n are each independently an integer of 1 or greater and m+n=50 or less. m and n are preferably each independently 3 to 40, 4 to 30, 6 to 20, 8 to 16, or 11 to 15.

[0036] Commercially available silicone surfactants with an HLB value of 10 or more and less than 15 are not particularly limited, but examples include KF-640 and KF-6013 (manufactured by Shin-Etsu Silicones Co., Ltd.).

[0037] Commercially available acetylene glycol surfactants with an HLB value of 10 or more and less than 15 are not particularly limited, but examples include E1010, EXP4200, and the like (manufactured by Nissin Chemical Industry Co., Ltd.).

[0038] The content of surfactant A is preferably 0.1% by mass to 2.0% by mass, 0.1% by mass to 1.5% by mass, 0.2% by mass to 1.3% by mass, 0.3% by mass to 1.1% by mass, or 0.4% by mass to 0.9% by mass, relative to the total amount of the ink composition. When the content of surfactant A is within the above range, ejection stability and storage stability tend to be further improved.

[0039] 1.2.2. Surfactant B Surfactant B is an acetylene glycol-based surfactant with an HLB value of 3 or more and less than 10. By using an acetylene glycol-based surfactant with an HLB value of 3 or more and less than 10, it is possible to increase the wettability of the relatively hydrophobic parts of the carbon black, promote the removal of air bubbles, and maintain good discharge stability. In addition, because the acetylene glycol-based surfactant is less likely to foam and has the same carbon skeleton as carbon black, it is thought to have a higher affinity and higher air bubble removal efficiency than other surfactants. The acetylene glycol surfactant used as surfactant B is preferably an acetylene glycol surfactant having or not having a polyether modifying group, for example, a compound represented by the following formula (1). [ka] Formula (1) (R1 to R4 each independently represent an alkyl group having 1 to 4 carbon atoms, and m and n each independently represent 0 or an integer of 1 or more, and satisfy m+n=20 or less.) Preferably, m and n are each independently 10 or less, more preferably 5 or less, even more preferably 2 or less, and particularly preferably 0. Examples of R1 to R4 include methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, and tert-butyl, and preferred examples thereof include methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, and tert-butyl.

[0040] The HLB value of surfactant B is 3 or more and less than 10, preferably 4 or more and 9.5 or less, 5 or more and 9 or less, or 6 or more and 8.5 or less. When the HLB value of surfactant B is within the above range, storage stability tends to be further improved.

[0041] The acetylene glycol surfactant having an HLB value of 3 or more and less than 10 is not particularly limited, but examples thereof include Surfynol SE, Surfynol 440, and Surfynol 104 (product names, manufactured by Nissin Chemical Industry Co., Ltd.).

[0042] The content of surfactant B is preferably 0.1% by mass to 1.0% by mass, 0.15% by mass to 0.75% by mass, or 0.2% by mass to 0.5% by mass, relative to the total amount of the ink composition. When the content of surfactant B is within the above range, ejection stability and storage stability tend to be further improved.

[0043] The mass ratio (B / A) of the content of surfactant B to surfactant A is preferably 0.1 to 1.5, 0.1 to 1.0, 0.2 to 0.9, 0.3 to 0.8, or 0.4 to 0.7. By setting the mass ratio of the content of surfactant B to surfactant A within the above range, ejection stability and storage stability tend to be further improved.

[0044] 1.2.3. Other surfactants The other surfactants are surfactants other than surfactant A and surfactant B, and are not particularly limited, but examples thereof include silicone-based surfactants, acetylene glycol-based surfactants, and fluorine-based surfactants.

[0045] The content of the other surfactants may be from 0% to 0.5% by mass, from 0.01% to 0.4% by mass, from 0.02% to 0.3% by mass, from 0.03% to 0.2% by mass, or from 0.04% to 0.1% by mass, relative to the total amount of the ink composition. Other surfactants may not be included. By setting the content of the other surfactants within the above ranges, ejection stability and storage stability tend to be further improved.

[0046] 1.3.Organic Solvents The ink composition of this embodiment may contain an organic solvent. Examples of the organic solvent include water-soluble organic solvents such as polyols and glycol ethers. One type of organic solvent may be used alone, or two or more types may be used in combination.

[0047] Polyols are compounds having two or more hydroxyl groups in the molecule, and examples thereof include hydrocarbons having two or more hydroxyl groups in the molecule, which may have an ether group in the hydrocarbon skeleton, and are therefore preferred.

[0048] Examples of polyols include ethylene glycol, propylene glycol, 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, propylene glycol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol, and glycerin.

[0049] The glycol ethers may be monoethers or diethers of alkylene glycols, and alkyl ethers are preferred. Specific examples include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ... alkylene glycol monoalkyl ethers such as ethylene glycol monobutyl ether; and alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol methyl butyl 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, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether.

[0050] Among the organic solvents listed above, the ink composition of this embodiment is preferably an organic solvent having an SP value of 8 (cal / cm 3 ) 1 / 2 More than 14(cal / cm 3 ) 1 / 2 The following organic solvent C may be contained.

[0051] The SP value of the organic solvent C is preferably 8 (cal / cm 3 ) 1 / 2 More than 14(cal / cm 3 ) 1 / 2 is less than 9 (cal / cm 3 ) 1 / 2 More than 13(cal / cm 3 ) 1 / 2 is less than 10(cal / cm 3 ) 1 / 2 More than 12.5(cal / cm 3 ) 1 / 2 The SP value of organic solvent C is 8 (cal / cm 3 ) 1 / 2 By setting the SP value of the organic solvent C to 14 (cal / cm or more), the compatibility of the components contained in the ink composition is improved, and the storage stability and ejection stability of the ink composition tend to be further improved. 3 ) 1 / 2 or below, there is a tendency for the solubility of surfactant B to be further improved. In particular, surfactant B has a relatively low solubility in water, and is prone to causing ejection defects, for example, when the ink dries in the nozzle and the amount of water is reduced, but by including organic solvent C, there is a tendency for ejection stability to be further improved even in such a state.

[0052] The SP value in this specification is a solubility parameter calculated based on the Hansen method. According to the Hansen method, the SP value is expressed by the following formula: δ 2 =δ d 2 +δ p 2 +δ h 2 (In the formula, δd is the solubility parameter corresponding to the dispersion force term, and δ p is the solubility parameter corresponding to the dipole-dipole force term, and δ h is the solubility parameter corresponding to the hydrogen bonding term.)

[0053] The SP value is based on the idea that two substances with similar intermolecular interactions are more likely to dissolve in each other. In addition to being able to roughly estimate the SP value by calculation, it can also be determined experimentally and empirically, and many values ​​are described in the literature. In this embodiment, the SP value can be a value derived using the calculation software HSPiP.

[0054] In addition, the unit of the SP value in this embodiment is (cal / cm 3 ) 1 / 2 In addition, 8 (cal / cm 3 ) 1 / 2 More than 14(cal / cm 3 ) 1 / 2 The range of SP values ​​below 16.4 (J / cm) is calculated using a different unit. 3 ) 1 / 2 More than 28.6(J / cm 3 ) 1 / 2 It can also be expressed as follows:

[0055] The organic solvent C preferably contains one or more selected from the group consisting of polyols and glycol ethers. By using such an organic solvent C, the storage stability and ejection stability of the ink composition tend to be further improved. In addition, the SP value is 8 (cal / cm 3 ) 1 / 2 More than 14(cal / cm 3 ) 1 / 2 The following polyols preferably satisfy the above SP value, and are preferably alkanediols having 5 or more carbon atoms, more preferably alkanediols having 5 to 10 carbon atoms, and further preferably 1,2-alkanediols.

[0056] Although not particularly limited, for example, 1,2-hexanediol and the like can be mentioned. In addition, the SP value is 8 (cal / cm3 ) 1 / 2 More than 14(cal / cm 3 ) 1 / 2 The following glycol ethers are not particularly limited, but include, for example, tripropylene glycol monomethyl ether.

[0057] The content of organic solvent C is preferably 1.0% by mass to 15% by mass, 2.0% by mass to 11% by mass, or 3.0% by mass to 8% by mass, relative to the total amount of the ink composition. By setting the content of organic solvent C within the above range, ejection stability and storage stability tend to be further improved.

[0058] The total content of the organic solvents relative to the total amount of the ink composition is preferably 5.0% by mass to 30% by mass, 7.5% by mass to 25% by mass, or 10% by mass to 20% by mass. By keeping the total content of the organic solvents within the above ranges, ejection stability and storage stability tend to be further improved.

[0059] The content of organic solvent C is preferably 10 to 55 mass%, 20 to 50 mass%, or 25 to 45 mass%, based on the total amount of all organic solvents. By setting the total content of the organic solvents within the above range, ejection stability and storage stability tend to be further improved.

[0060] The mass ratio (B / C) of the content of surfactant B to the content of organic solvent C is preferably 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.15 or less. Furthermore, the mass ratio (B / C) is preferably 0.01 or more, 0.02 or more, or 0.03 or more. By setting the mass ratio of the content of surfactant B to the content of organic solvent C within the above range, ejection stability and storage stability tend to be further improved.

[0061] 1.4.Water The ink composition of this embodiment is a water-based ink composition containing water. The water-based ink composition is an ink composition that contains at least water as the main solvent component of the ink.

[0062] The water content, relative to the total amount of the ink composition, is preferably 45% by mass or more, 50% by mass to 97% by mass, 60% by mass to 95% by mass, 65% by mass to 90% by mass, or 70% by mass to 85% by mass. By keeping the water content within the above range, storage stability tends to be further improved.

[0063] 1.5.Other Ingredients The ink composition may contain components other than those described above. As other components, various additives such as a dissolution aid, a viscosity adjuster, a pH adjuster, an antioxidant, a preservative, an antifungal agent, a corrosion inhibitor, and a chelating agent for capturing metal ions that affect dispersion may be appropriately added. For example, the ink composition may contain triethanolamine as a pH adjuster.

[0064] 2. Ink container The ink container according to this embodiment includes the ink-jet ink composition and a container that contains the ink-jet ink composition. Note that, in this embodiment, the ink container refers to a container that contains ink.

[0065] The ink composition contained in the ink container preferably has a dissolved nitrogen concentration of 2 ppm or more in the container. As the nitrogen concentration in the ink increases, vegetable oil CB and recycled CB, which have many voids, tend to absorb nitrogen, making the effects of the present invention more pronounced. The dissolved nitrogen concentration of the ink may be less than 2 ppm when the ink container is shipped, or may increase to 2 ppm or more between shipment and the start of use in the printer.

[0066] If a high concentration of dissolved nitrogen in the container is acceptable, for example, the process of thorough degassing during ink preparation can be omitted, thereby reducing the number of steps required for ink production. Furthermore, since the ink container does not need to have high gas barrier properties, the degree of freedom in container design is increased. This allows, for example, the use of highly flexible materials, enabling the container to have a larger capacity and at a lower cost.

[0067] 2.1. Container The container is not particularly limited, but examples thereof include an ink cartridge, an ink pack, an ink bottle, an ink tank, a bottle, and a can. Among these, from the viewpoint of versatility, an ink cartridge, an ink pack, an ink bottle, and an ink tank are preferred, and an ink pack and an ink bottle are more preferred.

[0068] 2.1.1.Ink pack The ink pack is not particularly limited, but may have, for example, a pack body that contains ink and an ink supply port. The constituent material of the pack body is not particularly limited, but may have, for example, a multilayer structure in which a resin film substrate layer that serves as a base material for ensuring basic strength is provided, and a gas barrier layer that provides gas barrier properties to the resin film substrate layer is laminated as needed.

[0069] The resin constituting the resin film substrate layer is not particularly limited, but examples thereof include polyester resins and polyolefin resins.

[0070] The gas barrier layer is not particularly limited, but is preferably a resin layer with excellent gas barrier properties, a vapor-deposited layer of a metal or metal compound, etc. For example, a film to which an aluminum foil layer is attached has high gas barrier properties and is less likely to have a high dissolved nitrogen concentration even after long-term storage.

[0071] The gas barrier layer using a resin layer is useful because it is resistant to tearing. Since the gas barrier property is slightly lower than that of a metal foil layer, the dissolved nitrogen concentration is likely to increase during storage, and even if the dissolved nitrogen concentration is low immediately after filling the ink container with ink, it is highly likely that the dissolved nitrogen concentration will increase during use, making the present invention particularly useful.

[0072] Furthermore, when a vapor-deposited layer of a metal or metal compound is used as the gas barrier layer, the gas barrier property is somewhat lower than that of a metal foil layer, and therefore the dissolved nitrogen concentration tends to increase during storage, and therefore the present invention is also particularly useful.

[0073] Resin layers with excellent gas barrier properties include, but are not limited to, nylon, ethylene-vinyl alcohol copolymer resin, polyvinylidene chloride, etc. Since the gas barrier properties of these resin layers are somewhat inferior to those of metal or metal compound layers, it is preferable to use a resin layer that is somewhat thicker than a metal film.

[0074] FIG. 5 shows an example of an ink pack of a container according to this embodiment. FIG. 5 is an exploded perspective view of the ink pack. The ink cartridge 10 comprises an ink pack 40 filled with ink, and a cartridge case 42 that houses and protects the ink pack 40 and is made up of a main case 46 and a lid 48. The ink pack 40 has an ink supply port 44. The main case 46 has a notch 50 and a groove 56, and the lid 48 has a retaining portion 52 and a hook 54. In the ink cartridge 10, the ink pack 40 is housed within the main case 46 and the lid 54. The ink supply port 44 is fitted into the notch 50 and is secured by being sandwiched between the retaining portion 52 and the notch 50. The main case 46 and the lid 54 are sealed by fitting the hook 54 into the groove 56. The film-like member that constitutes the ink pack 40 and contains the ink therein may be the member constituting the ink pack described above.

[0075] 2.1.2.Ink bottle The ink bottle is not particularly limited, but examples thereof include an ink bottle for refilling ink in a printer having a continuous ink supply system (CISS). The ink bottle is not particularly limited, but may have, for example, an ink ejection port and a bottle body that contains the ink.

[0076] The ink bottle is preferably a resin bottle, which is advantageous in terms of lightness and cost, but the present invention is particularly useful for such bottles because the dissolved nitrogen concentration tends to be high due to poor airtightness of the lid and poor gas barrier properties of the container itself.

[0077] The resin constituting the bottle body is not particularly limited, but examples thereof include polyester resin and polyolefin resin. Such materials are preferable because they have excellent impact resistance, but on the other hand, they have relatively poor gas barrier properties, and are therefore particularly useful as the ink container of this embodiment.

[0078] FIG. 6 shows an example of an ink bottle as a container according to this embodiment. FIG. 7 is a cross-sectional view of an example of an ink bottle. The ink composition IK described above is contained in the ink bottle 63. The ink bottle 63 has a cylindrical container body 64 as its main body. An ink outlet 62 is formed at the tip of the container body 64, allowing ink to flow out of the container body 64. When the ink bottle 63 is stored, a cylindrical cap 79 with a bottom covers part of the container body 64 so as to surround the ink outlet 62, sealing the ink outlet 62 from the outside. The cap 79 has a helical thread 78 formed on the inside, which rotates to engage and secure with a helical thread 82 formed on the outer surface of the container body 64. When ink is to flow out, the cap 79 is removed.

[0079] The container body 64 of the ink bottle 63 is a bottle-shaped member capable of containing an ink composition therein.

[0080] The bottle-shaped member is preferably made of, for example, a polyolefin resin such as polypropylene. Such a member is preferable because it has excellent impact resistance, but on the other hand, it has relatively poor gas barrier properties, and is therefore particularly useful as the ink container of this embodiment.

[0081] 3. Inkjet recording method The inkjet recording method according to this embodiment includes a step of ejecting the inkjet ink composition from a predetermined inkjet head and depositing it onto a recording medium. The inkjet recording method may further include a transport step of transporting the recording medium, and the depositing step and the transporting step may be carried out simultaneously. Other steps may be included as necessary.

[0082] 4. Inkjet recording device The inkjet recording apparatus of this embodiment includes the ink composition described above and an inkjet head having nozzles for ejecting the ink composition onto a recording medium, and preferably further includes a supply flow path for circulating the ink composition and connected to the inkjet head, and a filter unit provided in the supply flow path of the inkjet head. The inkjet recording apparatus further includes a mounting section (not shown) to which an ink container is attached, and ink is supplied from the ink container to the inkjet head. An ink pack is preferably used as the ink container in this example.

[0083] An example of an inkjet recording apparatus that can be used in this embodiment is shown in Figure 4. The inkjet recording apparatus according to this embodiment will be described in further detail with reference to the drawing. In the XYZ coordinate system shown in the drawing, the X direction indicates the length direction of the recording medium, the Y direction indicates the width direction of the recording medium in the transport path within the recording apparatus, and the Z direction indicates the height direction of the apparatus.

[0084] As an example, the recording device 10 is a line-type inkjet printer capable of high-speed, high-density printing. The recording device 10 includes a feed unit 12 that stores recording media P such as paper, a conveyance unit 14, a belt conveyance unit 16, a recording unit 8, an Fd (face-down) discharge unit 20 as an "discharge unit," an Fd (face-down) placement unit 22 as a "placement unit," a reversing path unit 24 as a "reversing conveyance mechanism," an Fu (face-up) discharge unit 26, and an Fu (face-up) placement unit 28.

[0085] The feeding unit 12 is disposed at the bottom of the recording device 10. The feeding unit 12 includes a feeding tray 30 that stores recording media P, and a feeding roller 32 that sends out the recording media P stored in the feeding tray 30 to the transport path 11.

[0086] The recording medium P stored in the feed tray 30 is fed by a feed roller 32 along the conveying path 11 to the conveying unit 14. The conveying unit 14 includes a conveying drive roller 34 and a conveying driven roller 36. The conveying drive roller 34 is driven to rotate by a drive source (not shown). In the conveying unit 14, the recording medium P is nipped between the conveying drive roller 34 and the conveying driven roller 36 and conveyed to the belt conveying unit 16 located downstream of the conveying path 11.

[0087] The belt conveying section 16 includes a first roller 38 located upstream on the conveying path 11, a second roller 40 located downstream, an endless belt 42 rotatably attached to the first roller 38 and the second roller 40, and a support 44 that supports the upper section 42a of the endless belt 42 between the first roller 38 and the second roller 40.

[0088] The endless belt 42 is driven by the first roller 38 or the second roller 40, which is driven by a drive source (not shown), so as to move from the +X direction to the −X direction in the upper section 42a. Therefore, the recording medium P conveyed from the conveying unit 14 is further conveyed downstream of the conveying path 11 in the belt conveying unit 16.

[0089] The recording unit 8 includes a line-type inkjet head 48 and a head holder 46 that holds the inkjet head 48. The recording unit 8 may also be a serial type in which the inkjet head is mounted on a carriage that moves back and forth in the Y-axis direction. The inkjet head 48 is disposed so as to face the upper section 42a of the endless belt 42 that is supported by a support 44. The inkjet head 48 ejects ink toward the recording medium P as the recording medium P is transported in the upper section 42a of the endless belt 42, thereby performing recording. The recording medium P is transported downstream of the transport path 11 by the belt transport unit 16 while recording is being performed.

[0090] A first branching section 50 is provided downstream of the conveying path 11 of the belt conveying unit 16. The first branching section 50 is configured to be switchable between the conveying path 11 that conveys the recording medium P to the Fd discharge unit 20 or the Fu discharge unit 26 and a reversing path 52 of the reversing path unit 24 that reverses the recorded side of the recording medium P and conveys the recording medium P again to the recording unit 8. The recording medium P that is switched to the reversing path 52 by the first branching section 50 and conveyed has its recorded side reversed during the conveying process on the reversing path 52, and is conveyed again to the recording unit 8 so that the side opposite to the initially recorded side faces the inkjet head 48.

[0091] A second branch section 54 is further provided downstream of the first branch section 50 along the conveying path 11. The second branch section 54 is configured to be able to switch the conveying direction of the recording medium P so that the recording medium P is conveyed toward the Fd discharge section 20 or the recording medium P is conveyed toward the Fu discharge section 26.

[0092] The recording medium P transported from the second branching section 54 toward the Fd discharge section 20 is discharged from the Fd discharge section 20 and placed on the Fd placement section 22. At this time, the recording medium P is placed so that the recorded surface faces the Fd placement section 22. Also, the recording medium P transported from the second branching section 54 toward the Fu discharge section 26 is discharged from the Fu discharge section 26 and placed on the Fu placement section 28. At this time, the recording medium P is placed so that the recorded surface faces away from the Fu placement section 28.

[0093] 7 is a perspective view of another example of a recording apparatus used in the recording method of this embodiment. The inkjet recording apparatus 1 in the figure has an ink tank 50 and an ink supply pipe 24 that supplies ink from the ink tank 50 to the inkjet head 17. A sub-tank 20 that relays ink is provided in the ink supply path between the ink tank 50 and the inkjet head 17. The sub-tank 20 that relays ink may be provided as needed.

[0094] The ink tank 50 has an ink inlet 54 through which ink is poured from an ink container (not shown). In this embodiment, the container of the ink container is an ink bottle, and ink from the ink bottle is poured into the ink tank 50 through the ink inlet 54.

[0095] In the recording device of this embodiment, the ink tank 50 is a CISS tank (continuous ink supply system tank), and ink is injected into the ink tank 50 from the ink bottle at any time, eliminating the need to replace ink cartridges and allowing for continuous recording without interruption.

[0096] The ink tank 50 is made up of four ink tanks so that four inks can be poured into it, and has four ink pouring ports. There are also four connections from the ink supply pipes 24 to the inkjet heads 17.

[0097] The inkjet head 17 ejects droplets of an ink composition to record an image on a recording medium. The inkjet head 17 also includes a carriage 16 that is mounted with a subtank 20 and the inkjet head 17 and that can move back and forth 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 unit 13 that supports the recording medium fed to the paper feed port 12. The inkjet head 17 has a nozzle surface that is located opposite the recording surface of the recording medium, and ejects ink in the form of droplets from multiple nozzles on the nozzle surface to adhere to the recording surface of the recording medium.

[0098] The inkjet recording method of this example may be, and preferably is, carried out using a recording apparatus having an ink tank having an ink inlet for injecting the inkjet ink composition from the ink bottle as the container, and an inkjet head to which the inkjet ink composition is supplied from the ink tank, and in this case too, ink is ultimately supplied from the ink bottle to the inkjet head.

[0099] 5. Recording Media The recording medium used in this embodiment is not particularly limited, and examples thereof include absorbent recording media, low absorbent recording media, and non-absorbent recording media, with absorbent recording media being preferred.

[0100] Examples of absorbent recording media include plain paper such as electrophotographic paper, which has high ink permeability, and inkjet paper (paper specifically for inkjet printers, which has an ink absorbing layer made of silica particles or alumina particles, or an ink absorbing layer made of a hydrophilic polymer such as polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP)).

[0101] Examples of low-absorbency recording media include art paper, coated paper, cast paper, and the like, which are used in general offset printing and have relatively low ink permeability.

[0102] Examples of low-absorbency recording media include films and plates of plastics such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate, polystyrene, and polyurethane; plates of metals such as iron, silver, copper, and aluminum; metal plates and plastic films made by vapor deposition of these various metals, and alloy plates such as stainless steel and brass; and recording media in which a plastic film such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate, polystyrene, and polyurethane is adhered (coated) to a paper substrate.

[0103] 6. Recordings The recorded matter of this embodiment is obtained by applying the ink composition described above to a recording medium. The recorded matter of this embodiment using the ink composition described above is excellent in recording quality while reducing carbon dioxide emissions, and is therefore an excellent sustainable environmentally friendly measure. [Example]

[0104] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0105] 1, 2, and 3, Tables 1, 2, and 3 show the compositions and evaluation results of the ink compositions of Examples, Comparative Examples, and Reference Examples. The numerical values ​​for each component of the ink compositions shown in the tables represent mass % unless otherwise specified. Furthermore, the numerical values ​​for carbon black dispersions in the tables represent the mass % of the solid content of the component.

[0106] 1. Preparation of Ink Composition The inkjet ink compositions of each example were obtained by placing the components in a mixing tank, mixing and stirring, and filtering through a membrane filter so as to obtain the compositions shown in Tables 1, 2, and 3. The numerical values ​​for each component shown in each example in the tables represent % by mass unless otherwise specified. Furthermore, in the tables, each numerical value represents % by mass of the solid content of the component. The pigment is the solid content of the pigment.

[0107] The abbreviations and product ingredient details used in Tables 1, 2 and 3 are as follows: Non-biomass means that it is derived from petroleum, not from plants.

[0108] [Carbon black] Carbon Black 1: Vegetable oil carbon black (PRINTEX Nature, manufactured by Orion Engineered Carbons Co., Ltd.) Carbon Black 2: Non-biomass carbon black (MA100, manufactured by Mitsubishi Chemical Corporation) Carbon black 3: Binchotan carbon black (Kishu Binchotan powder, manufactured by Kiriya Chemical Co., Ltd.)

[0109] <Carbon black 1 dispersion> Carbon black 1 was pulverized and mixed with water. The mixture was then subjected to ozone treatment for 6 hours at an ozone concentration of 5.5 to 6.0%. After treatment, the carbon black was washed, and potassium hydroxide was added to the carbon black, followed by dispersion in water. This resulted in a dispersion of a self-dispersing carbon black pigment having potassium as a counter ion (hereinafter referred to as "carbon black 1 dispersion"). The volume-average particle diameter D50 of the secondary particles of the carbon black pigment in the dispersion, as measured by dynamic light scattering, was 110 nm. The above treatment results in a self-dispersing pigment in which carboxyl groups have been introduced onto the surface of the carbon black.

[0110] <Carbon Black 2 Dispersion> Carbon black dispersion 2 is obtained in the same manner except for using carbon black 2. The volume average particle diameter D50 of the secondary particles of the carbon black pigment in the dispersion measured by dynamic light scattering is 90 nm.

[0111] <Carbon black 3 dispersion> Carbon black dispersion 3 is obtained in the same manner except for using carbon black 3. The volume average particle diameter D50 of the secondary particles of the carbon black pigment in the dispersion measured by dynamic light scattering is 180 nm.

[0112] [Surfactants] (Surfactant A) KF-640 (silicone surfactant, HLB value 14, manufactured by Shin-Etsu Silicone Co., Ltd.) KF-6013 (silicone surfactant, HLB value 10, manufactured by Shin-Etsu Silicone Co., Ltd.) E1010 (acetylene glycol surfactant, HLB value 13-14, manufactured by Nissin Chemical Industry Co., Ltd.) EXP4200 (acetylene glycol surfactant, HLB value 10-13, manufactured by Nissin Chemical Industry Co., Ltd.) (Surfactant B) Surfynol SE (acetylene glycol surfactant, HLB value 6, manufactured by Nissin Chemical Industry Co., Ltd.) Surfynol 440 (acetylene glycol surfactant, HLB value 8, manufactured by Nissin Chemical Industry Co., Ltd.) Surfynol 104 (acetylene glycol surfactant, HLB value 4, manufactured by Nissin Chemical Industry Co., Ltd.) (Other surfactants) E1020 (acetylene glycol surfactant, HLB value 15-16, manufactured by Nissin Chemical Industry Co., Ltd.) KF-6015 (silicone surfactant, HLB value 5, manufactured by Shin-Etsu Silicone Co., Ltd.) KF-6012 (silicone surfactant, HLB value 7, manufactured by Shin-Etsu Silicone Co., Ltd.) [Organic solvents] Glycerin (SP value 16.7) Propylene glycol (SP value 14.2) 1,2-Hexanediol (SP value 12.2) Tripropylene glycol monomethyl ether (SP value 9.1) Tripropylene glycol dimethyl ether (SP value 7.4) [alkali] Triethanolamine [water] Ion-exchanged water

[0113] 2. Ink container <Container 1> A multilayer film was prepared by depositing a 30 nm thick layer of aluminum on one side of an 80 μm thick low-density polyethylene (PE) film. The resulting film was then used to prepare an ink pack (hereinafter referred to as "Container 1") for containing the ink composition.

[0114] <Container 2> A multilayer film was prepared by laminating a 30 μm thick nylon film on one side of an 80 μm thick low-density polyethylene (PE) film, and then using the resulting film, an ink pack (hereinafter referred to as "container 2") for containing the ink composition was prepared.

[0115] <Container 3> An ink bottle (hereinafter referred to as "container 3") is produced using polyethylene by stretch blow molding. The volume of each container is 200 ml.

[0116] 2.1. Dissolved nitrogen content The ink-jet ink composition prepared as described above is filled into each of the containers to produce a container. After the period indicated in the table from filling, the amount of dissolved nitrogen in the ink in the container is measured by mass using a gas chromatograph 6890N (trade name, manufactured by Agilent).

[0117] 3. Evaluation Method 3.1.Continuous discharge The container used for the above-mentioned dissolved nitrogen amount, which had been filled into the container for each example period shown in the table, was set into a modified PX-H6000 inkjet printer (manufactured by Seiko Epson Corporation), and the inkjet ink composition contained in the container was filled. FUJI XEROX printer paper "P" (A4 size) was set, and continuous printing was performed at a resolution of 720 dpi x 1440 dpi. A nozzle check was performed every five sheets to confirm that printing was normal without missing or bending. Evaluation was performed according to the following criteria, and the results are shown in the table. The evaluation criteria were as follows. In the example where the ink container was container 3, a CISS tank was attached to the inkjet printer, and the CISS tank was filled with ink from the container. (Evaluation criteria) A: More than 100 sheets can be printed normally. B: Prints normally between 50 and 100 sheets C: Prints normally between 5 and 50 sheets D: Missing or deflection occurs when there are less than 5 sheets.

[0118] 3.2.Clogging evaluation As with the continuous ejection test, the inkjet ink composition was filled into all rows of the head of a modified PX-H6000 inkjet printer (manufactured by Seiko Epson Corporation), and normal ejection was confirmed for all rows. The print head was then shifted from its standby position and stopped in the printing area, and left for three days in an environment of 40°C and 20% relative humidity. After leaving the print head, the print head was returned to its standby position, and the nozzle surface was wiped using a rubber wiper. A cleaning process was then performed, and the number of cleanings required until ejection was restored for all nozzles was counted. (Evaluation criteria) A: All nozzles will recover after one cleaning or less. B: All nozzles recover after 2 to 5 cleanings. C: All nozzles recover after 6 to 10 cleanings. D: No recovery even after 11 cleanings

[0119] 3.3.Storage stability Each ink composition was placed in a 50cc glass sample bottle after the period indicated in the table had elapsed since filling into the container, and then sealed. These glass bottles were then placed in a 50°C thermostatic chamber and left at 50°C for three days. The bottles were then returned to room temperature and the viscosity was measured. The viscosity was determined by adjusting the temperature of the ink composition to 25°C using a Pysica MCR-300 (product name) viscoelasticity tester and reading the viscosity at a shear rate of 200 / sec. The rate of viscosity change after 14 days of storage in the sample bottle, relative to the initial viscosity of the ink composition before sealing in the sample bottle, was then calculated. The evaluation criteria were as follows: (Evaluation criteria) A: Viscosity change rate is less than ±5% B: Viscosity change rate is between ±5% and 10% C: Viscosity change rate is ±10% or more

[0120] 4. Evaluation Results The composition of the ink used in each example and the evaluation results are shown in Table 1. Table 1 shows that the inkjet ink composition containing vegetable oil CB, surfactant A having an HLB value of 10 or more and less than 15, and surfactant B, an acetylene glycol surfactant having an HLB value of 3 or more and less than 10, had excellent ejection stability and storage stability. Although not shown in the table, container 4 was prepared by attaching a 10 μm thick aluminum foil layer to one side of an 80 μm thick low-density polyethylene (PE) film, and an ink pack was similarly prepared using the obtained film. When this was used to evaluate the ink pack in the same manner as in Comparative Example 4, the amount of dissolved nitrogen was 3 ppm even after one year, and the continuous discharge evaluation and clogging evaluation were both rated B. [Explanation of symbols]

[0121] 10...recording device, 11...transport path, 12...feed section, 14...transport section, 16...belt transport section, 18...recording section, 20...Fd discharge section, 22...Fd placement section, 24...reversal path section, 26...Fu discharge section, 28...Fu placement section, 30...feed tray, 32...feed roller, 34...transport drive roller, 36...transport driven roller, 38...first roller, 40...second roller, 42...endless belt, 42a...upper section of endless belt, 44...support, 46...head holder, 48...inkjet head, 50...first branch section, 52...reversal path, 54...second branch section, 56...discharge roller pair, 64...discharge drive roller, 68...drive shaft, 76...placement surface, 78...convex section, 80...first urging member, 82...second urging member, 84, 86...support shaft, P...recording medium.

Claims

1. Contains a pigment and a surfactant, the pigment comprises carbon black derived from vegetable oil or carbon black derived from recycled materials; The surfactants include a surfactant A having an HLB value of 10 or more and less than 15, and a surfactant B which is an acetylene glycol-based surfactant having an HLB value of 3 or more and less than 10, It is a water-based ink, Inkjet ink composition.

2. SP value is 8 (cal / cm 3 ) 1 / 2 Above 14 (cal / cm 3 ) 1 / 2 Contains an organic solvent C which is: The ink-jet ink composition of claim 1 .

3. a mass ratio (B / C) of the content of the surfactant B to the content of the organic solvent C is 0.3 or less; The ink-jet ink composition of claim 2.

4. a mass ratio (B / A) of the content of the surfactant B to the content of the surfactant A is 0.1 or more and 1.0 or less; The ink-jet ink composition of claim 1 .

5. The carbon black is a self-dispersing pigment. The ink-jet ink composition of claim 1 .

6. The surfactant A includes at least one selected from the group consisting of silicone-based surfactants and acetylene glycol-based surfactants. The ink-jet ink composition of claim 1 .

7. The organic solvent C includes at least one selected from the group consisting of polyols and glycol ethers. The ink-jet ink composition of claim 2.

8. the content of the surfactant A is 0.1% by mass or more and 1.5% by mass or less with respect to the total amount of the inkjet ink composition, the content of the surfactant B is 0.1% by mass or more and 1.0% by mass or less with respect to the total amount of the inkjet ink composition; The ink-jet ink composition of claim 1 .

9. the content of the organic solvent C is 1.0% by mass or more and 15% by mass or less with respect to the total amount of the inkjet ink composition; The ink-jet ink composition of claim 2.

10. The inkjet ink composition according to any one of claims 1 to 9, a container containing the ink-jet ink composition; Ink container.

11. the inkjet ink composition has a dissolved nitrogen concentration of 2 ppm or more; The ink container according to claim 10.

12. The container is either an ink pack made of a member having a multilayer structure or an ink bottle made of resin. The ink container according to claim 10.

13. A method for producing an ink jet recording medium, comprising a step of ejecting the ink jet ink composition according to any one of claims 1 to 9 from an ink jet head and depositing the ink jet ink composition on a recording medium. Recording method.

Images