Inkjet ink composition and recording method

Abstract

Provided is an inkjet ink composition that is excellent in color development, storage stability, continuous ejection stability, and clogging recovery. The present invention relates to a pigment-containing composition, the pigment comprising vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black, the vegetable oil-derived carbon black and / or recycled raw material-derived carbon black having a BET specific surface area of ​​50 m 2 / g or more 120m 2 / g or less, and the BET specific surface area of ​​the petroleum-derived carbon black is 160 m 2 / g or more 280m 2 / g or less, and the ink-jet ink composition is a water-based ink.

Description

[Technical Field]

[0001] The present invention relates to an ink-jet ink composition and a recording method. [Background technology]

[0002] The inkjet recording method is capable of recording high-resolution images with a relatively simple device, and has been rapidly developed in various fields. For example, Patent Document 1 discloses a water-based inkjet ink composition for the purpose of providing an aqueous inkjet ink composition that is environmentally friendly and has excellent storage stability, the water-based inkjet ink composition comprising a colorant of biological origin, a dispersant of biological origin, and an organic solvent of biological origin, the organic solvent having 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]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-128719 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when using environmentally friendly carbon black, such as vegetable oil-derived carbon black, as the carbon black used as a coloring material for inkjet ink, there is still room for improvement in color development and storage stability.

[0005] Furthermore, when vegetable oil-derived carbon black and petroleum-derived carbon black are used in combination, there is still room for improvement in the continuous ejection stability and clogging recovery properties during inkjet ejection. [Means for solving the problem]

[0006] The inkjet ink composition of the present invention according to the first embodiment contains a pigment, and the pigment contains vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black, and the vegetable oil-derived carbon black and / or the recycled raw material-derived carbon black has a BET specific surface area of ​​50 m 2 / g or more 120m 2 / g or less, and the BET specific surface area of ​​the petroleum-derived carbon black is 160 m 2 / g or more 280m 2 / g or less, and it is a water-based ink.

[0007] The inkjet ink composition of the present invention according to the second embodiment contains a pigment and a surfactant, wherein the pigment includes vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black, and the surfactant includes 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, and is a water-based ink.

[0008] In the recording method according to the first and second embodiments of the present invention, an ink using the ink-jet ink composition is deposited on a recording medium. [Brief explanation of the drawings]

[0009] [Figure 1] Table 1 shows the compositions 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 diagram illustrating an example of a printing apparatus used in the printing method of the first and second embodiments. [Figure 5] 3A and 3B are diagrams illustrating an example of an ink container used in the recording methods of the first and second embodiments. [Figure 6]FIG. 10 is a diagram showing another example of an ink container used in the recording method of the first and second embodiments. [Figure 7] FIG. 10 is a diagram illustrating another example of a printing apparatus used in the printing method according to the first and second embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0010] Each embodiment will be described in detail below with reference to the drawings as necessary, but the present invention is not limited to these and various modifications are possible without departing from the spirit of the present invention. In the drawings, the same elements are designated by the same reference numerals, and redundant explanations will be omitted. Furthermore, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to those shown.

[0011] 1. First embodiment First, the inkjet ink composition according to the first embodiment will be described.

[0012] 1.1. Inkjet ink composition The inkjet ink composition according to the first embodiment contains a pigment, and the pigment contains vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black, and the vegetable oil-derived carbon black and / or the recycled raw material-derived carbon black has a BET specific surface area of ​​50 m 2 / g or more 120m 2 / g or less, and the BET specific surface area of ​​the petroleum-derived carbon black is 160 m 2 / g or more 280m 2 / g or less, and it is a water-based ink.

[0013] Vegetable oil-derived carbon black is useful as a naturally derived carbon black that can contribute to reducing carbon dioxide emissions, and has the advantage of being easy to control particle size because it can be produced using the same manufacturing process as petroleum carbon black, in that it is carbonized by burning the liquid raw material (oil).Furthermore, impurities can be easily reduced by refining the liquid raw material (vegetable oil).

[0014] However, because vegetable oil-derived carbon black contains various components in its raw materials, the secondary particles of the carbonized material tend to have an irregular structure rather than a spherical shape. Furthermore, vegetable oil-derived carbon black tends to have a small specific surface area, i.e., the average particle size of the secondary particles tends to be large. Therefore, when vegetable oil-derived carbon black is layered on a recording medium, gaps may form, resulting in a decrease in blackness and poor color development. Like vegetable oil-derived carbon black, recycled carbon black can also have the same problems because it contains various components in its raw materials.

[0015] Therefore, in the first embodiment, in addition to the vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, a carbon black having a BET specific surface area of ​​160 m 2 / g or more 280m 2 Petroleum-derived carbon black with a carbon content of 0.1g or less is used.

[0016] Petroleum-derived carbon black with a BET specific surface area within the above range has a small average particle size of secondary particles. Therefore, it is believed that the petroleum-derived carbon black penetrates into and fills the gaps between vegetable oil-derived carbon black and recycled raw material-derived carbon black, thereby improving color development. Meanwhile, petroleum-derived carbon black with a relatively large specific surface area is prone to aggregation due to the high level of intermolecular forces, which tends to result in poor storage stability. However, in the first embodiment, the use of vegetable oil-derived carbon black with a relatively small specific surface area prevents aggregation due to the high level of intermolecular forces, resulting in excellent storage stability.

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

[0018] 1.1.1.Pigments In the first embodiment, the pigment has a BET specific surface area of ​​50 m 2 / g or more 120m 2 / g or less, and vegetable oil-derived carbon black and / or recycled raw material-derived carbon black (hereinafter simply referred to as "vegetable oil-derived carbon black, etc.") with a BET specific surface area of ​​160m 2 / g or more 280m 2 This includes petroleum-derived carbon black with a BET specific surface area of ​​0.1 / g or less. Vegetable oil-derived carbon black and recycled raw material-derived carbon black with a BET specific surface area within the above range can contribute to reducing carbon dioxide emissions, and also tend to have excellent storage stability when used alone. Furthermore, petroleum-derived carbon black with a large BET specific surface area has a small secondary particle diameter, allowing the vegetable oil-derived carbon black or recycled raw material-derived carbon black to fill gaps that occur on recording media, resulting in excellent color development. On the other hand, such petroleum-derived carbon black is prone to aggregation due to its small secondary particle diameter, resulting in poor storage stability, but storage stability can be improved by using it in combination with vegetable oil-derived carbon black or the like.

[0019] The BET specific surface area of ​​the vegetable oil-derived carbon black and the recycled raw material-derived carbon black is preferably 50 m 2 / g or more 120m 2 / g or less, and 60m 2 / g or more 110m 2 / g or less, and 2 / g or more 100m 2 When the BET specific surface area is within the above range, the storage stability and color development property tend to be further improved.

[0020] The petroleum-derived carbon black preferably has a BET specific surface area of ​​160 m 2 / g or more 280m 2 / g or less, and 180m 2 / g or more 270m 2 / g or less, and 200m 2 / g or more 250m 2 / g or less, and 210m 2 / g or more 240m 2 When the BET specific surface area is within the above range, the storage stability and color development property tend to be further improved.

[0021] The BET specific surface area of ​​carbon black can be measured by placing the carbon black in a sample cell, flushing with nitrogen gas, and drying at 150°C for 1.5 hours to remove moisture. Specifically, the mass of the carbon black and the atmospheric pressure at the time of measurement are measured, and the amount of nitrogen adsorption per gram is measured at five relative atmospheric pressures: 0.1, 0.15, 0.2, 0.25, and 0.3 times the atmospheric pressure. The specific surface area is calculated using the BET method from the nitrogen absorption amounts at these five points. Measurements can be made using, for example, a GEMINI 2360 (a BET specific surface area analyzer manufactured by Micromeritics).

[0022] The BET specific surface area of ​​carbon black can be controlled by adjusting the temperature of the combustion gas during production, the amount of oxygen-containing gas during combustion, the amount of feed hydrocarbon (vegetable oil or liquid oil such as petroleum) supplied, etc. For example, in the furnace method of producing carbon black by injecting feed oil such as petroleum or coal oil into high-temperature gas and causing incomplete combustion, the lower the temperature of the combustion gas stream into which the feed hydrocarbon is introduced, the smaller the BET specific surface area of ​​the carbon black.

[0023] 1.1.1.1. Vegetable oil-derived carbon black Vegetable oil-derived carbon black is produced by carbonizing vegetable oil, and its manufacturing process is similar to that of petroleum carbon black in that it is produced by burning a liquid and carbonizing it, making it relatively easy to produce. Specific examples of vegetable oil-derived carbon black include carbon black made from plant seed oil, tall oil, or wood tar, or modified products such as hydrogenated products or derivatives of these plant seed oils, tall oil, or wood tar. Further specific examples of vegetable oils include avocado oil, linseed oil, almond oil, fennel oil, perilla oil, olive oil, orange oil, orange roughage oil, cocoa butter, chamomile oil, carrot oil, cucumber oil, apricot kernel oil, kukui nut oil, walnut oil, wheat germ oil, sesame oil, rice oil, rice bran oil, camellia oil, safflower oil, salad oil, shea butter, soybean oil, tea oil, evening primrose oil, camellia oil, and raspberry oil. Examples of suitable oils include sorghum oil, rapeseed oil, persic oil, safflower oil, castor oil, sunflower oil, grapeseed oil, hazelnut oil, macadamia nut oil, cottonseed oil, meadowfoam oil, peanut oil, rosehip oil, turtle oil, cocoa butter, palm oil, palm kernel oil, Japan wax, coconut oil, the above-mentioned wood tar (wood tar oil), tall oil, wood creosote, and modified products of hydrogenated products or derivatives thereof. Note that modified products are vegetable oils that have been modified within the scope of the effects of the first embodiment.

[0024] 1.1.1.2. Carbon black made from recycled materials Carbon black derived from recycled materials is carbon black obtained by decomposing and refining waste. Here, waste refers to used products containing carbon, such as rubber and tires, and preferably used products containing carbon black. Here, "used products" includes not only products that have been used, but also products that have been manufactured but discarded without being used. Such carbon black derived from recycled materials can contribute to reducing carbon dioxide emissions. Furthermore, because, like vegetable oil-derived carbon black, the raw materials contain various components, the secondary particles tend to be irregular and large in diameter when made into carbon black, and storage stability tends to be poor. Therefore, the effects of the first embodiment are significant. Vegetable oil-derived carbon black is preferred because of its ease of acquisition and production.

[0025] The vegetable oil-derived carbon black and / or recycled raw material-derived carbon black is preferably a self-dispersing pigment. Use of such carbon black is preferred because it tends to more easily achieve the effects of the present embodiment and to further improve storage stability and color development.

[0026] Here, a 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 subjected to physical and / or chemical surface treatment to introduce hydrophilic functional groups onto the pigment surface and then dispersed in a solvent. Examples of hydrophilic functional groups include anionic groups such as carboxyl groups, sulfo groups, and phosphorus-containing acid groups. Examples of phosphorus-containing acid groups include phosphate groups and phosphonic acid groups. Alternatively, vegetable oil-derived carbon black and / or recycled raw material-derived carbon black may be dispersed in a solvent using a resin to form a resin-dispersed pigment.

[0027] The total content of vegetable oil-derived carbon black and recycled raw material-derived carbon black is preferably 10% by mass to 50% by mass, 20% by mass to 40% by mass, 23% by mass to 37% by mass, or 25% by mass to 35% by mass, based on the total amount of vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black. When the total content of vegetable oil-derived carbon black and recycled raw material-derived carbon black is within the above range, storage stability and color development tend to be further improved.

[0028] The total content of the vegetable oil-derived carbon black and recycled raw material-derived carbon black, relative to the total amount of the inkjet ink composition, is preferably 0.5% by mass to 6% by mass, 1% by mass to 4% by mass, 1.3% by mass to 3% by mass, or 1.5% by mass to 2% by mass. When the total content of the vegetable oil-derived carbon black and recycled raw material-derived carbon black is within the above range, storage stability and color development tend to be further improved.

[0029] 1.1.1.3.Petroleum-derived carbon black Petroleum-derived carbon black is carbon black obtained by carbonizing petroleum-based oil. In the first embodiment, the use of petroleum-derived carbon black with a small secondary particle diameter allows the vegetable oil-derived carbon black and recycled raw material-derived carbon black to fill gaps that occur on the recording medium, resulting in excellent color development. On the other hand, such petroleum-derived carbon black with a large specific surface area tends to be susceptible to intermolecular forces and to have poor storage stability. However, by using it in combination with vegetable oil-derived carbon black with a relatively small specific surface area, an inkjet ink composition with excellent storage stability can be obtained.

[0030] It is presumed that by dispersing a mixture of vegetable oil-derived carbon black and / or recycled raw material-derived carbon black and petroleum-derived carbon black in the ink composition, the intermolecular forces between the petroleum-derived carbon black molecules are alleviated, preventing the petroleum-derived carbon black molecules from aggregating together.

[0031] When the petroleum-derived carbon black is a self-dispersing pigment, the effects of the present embodiment tend to be more readily achieved and the storage stability and color development tend to be further improved, which is preferable. Alternatively, the petroleum-derived carbon black may be a resin-dispersed pigment.

[0032] The content of petroleum-derived carbon black is preferably 1 to 9 mass%, 2 to 8 mass%, 2.5 to 6 mass%, 3 to 5 mass%, or 3.3 to 3.8 mass%, relative to the total amount of the ink-jet ink composition. When the content of petroleum-derived carbon black is within the above range, storage stability and color development tend to be further improved.

[0033] The content of petroleum-derived carbon black is preferably 30 to 99 mass%, 50 to 90 mass%, 55 to 85 mass%, or 65 to 75 mass% based on the total content of vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black. When the content of petroleum-derived carbon black is within the above range, storage stability and color development tend to be further improved.

[0034] The total content of vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black is preferably 4% by mass to 10% by mass, 4% by mass to 8% by mass, 4.3% by mass to 7% by mass, or 4.5% by mass to 6% by mass, relative to the total amount of the inkjet ink composition. When the total content of vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black is within the above range, storage stability and color development tend to be further improved.

[0035] The pigment contained in the ink composition according to the first embodiment may also have the structure of the pigment contained in the ink composition according to the first embodiment, which will be described later.

[0036] Other components of the ink composition according to the first embodiment will be described later.

[0037] 2. Second embodiment Next, an inkjet ink composition according to a second embodiment will be described.

[0038] 2.1. Inkjet ink composition The inkjet ink composition according to the second embodiment is a water-based ink containing a pigment and a surfactant, wherein the pigment includes vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black, and the surfactant includes 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.

[0039] Vegetable oil-derived carbon black is useful as a naturally derived carbon black that can contribute to reducing carbon dioxide emissions, and has the advantage of being easy to control particle size because it can be produced using the same manufacturing process as petroleum carbon black, in that it is carbonized by burning the liquid raw material (oil).Furthermore, impurities can be easily reduced by refining the liquid raw material (vegetable oil).

[0040] However, because the vegetable oil used as the raw material contains various organic substances, the vegetable oil-derived carbon black produced contains numerous voids of different sizes and shapes within its interior, and the structure may contain a mixture of highly and less hydrophobic areas. Air bubbles are likely to remain in these voids, and the air bubbles remaining in the vegetable oil-derived carbon black act as bubble nuclei that grow due to the dissolved nitrogen in the inkjet ink composition. It is believed that the air bubbles that grow in this way separate from the pigment, reducing continuous ejection stability and clogging recovery.

[0041] 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.

[0042] Similarly to vegetable oil-derived carbon black, recycled carbon black obtained by pyrolysis of waste materials such as tires contains a large number of voids of different sizes and shapes inside the recycled carbon black because the waste materials contain a variety of components, and the resulting recycled carbon black may contain a mixture of highly and less hydrophilic portions within its structure. As a result, like vegetable oil-derived carbon black, problems such as reduced continuous discharge stability and reduced clogging recovery may occur.

[0043] In such cases, adding a surfactant may be considered to improve wettability, but vegetable oil-derived carbon black and recycled raw material-derived carbon black coexist in areas with different wettability, and when petroleum-derived carbon black is used in combination, the petroleum-derived carbon black also has different wettability, making it difficult to effectively increase wettability.

[0044] Therefore, in the second embodiment, two types of surfactants, surfactant A and surfactant B, are used. This increases the wettability of the voids in the vegetable oil-derived carbon black, recycled material-derived carbon black, and petroleum-derived carbon black, facilitating the removal of fine bubbles and preventing voids from remaining. Specifically, surfactant A, which has an HLB value of 10 or more and less than 15, increases the wettability of the less hydrophobic portions of the vegetable oil-derived carbon black and recycled material-derived carbon black, while surfactant B, an acetylene glycol-based surfactant with an HLB value of 3 or more and less than 10, increases the wettability of the more hydrophobic portions of the vegetable oil-derived carbon black and recycled material-derived carbon black.

[0045] It is speculated that vegetable oil-derived carbon black and vegetable oil are not completely carbonized, and some vegetable oil is mixed in as an impurity with the carbon black, and that vegetable oil contains various organic substances, and the degree of impurity mixing is not constant depending on the part of the carbon black, etc., which are factors that cause the carbon black to have parts with relatively high hydrophobicity and parts with relatively low hydrophobicity. It is also speculated that because vegetable oil is used as the raw material, there are relatively many parts with relatively high hydrophobicity.

[0046] It is assumed that recycled carbon black also has low and high hydrophobicity areas due to the fact that the raw materials contain various components.

[0047] On the other hand, petroleum-derived carbon black is not made from vegetable oil as a raw material, and therefore it is presumed that it has relatively low hydrophobicity portions and that the number of relatively low hydrophobic portions is relatively large.

[0048] By using two types of surfactants, surfactant A and surfactant B, described below, for such vegetable oil-derived carbon black and / or recycled raw material-derived carbon black and petroleum-derived carbon black, it is believed that the wettability of the carbon black as a whole is improved, the removal of air bubbles from the vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black is promoted, and good continuous discharge stability and clogging recovery can be maintained even in cases where the dissolved nitrogen increases over time.

[0049] 2.1.1.Pigments The pigment of the second embodiment includes vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black. As described above, vegetable oil-derived carbon black and / or recycled raw material-derived carbon black contain various components in their raw materials, and therefore contain voids of different sizes and shapes resulting from these components, including highly hydrophobic and less hydrophobic portions. Furthermore, petroleum-derived carbon black has many relatively less hydrophobic portions. Therefore, inkjet ink compositions containing these carbon blacks are difficult to remove bubbles from and are prone to ejection defects, making the effects of the present invention particularly pronounced.

[0050] As the vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black, those exemplified in the first embodiment can be used as appropriate.

[0051] The vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black are preferably self-dispersed pigments. The use of such carbon blacks is preferred because it is easier to achieve the effects of the present embodiment and tends to maintain good continuous discharge stability and clogging recovery. Furthermore, they are also preferred because they offer better storage stability and color development. Alternatively, the vegetable oil-derived carbon black and / or recycled raw material-derived carbon black and petroleum-derived carbon black may be used as resin-dispersed pigments.

[0052] The total content of vegetable oil-derived carbon black and recycled raw material-derived carbon black relative to the total amount of vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black may be in the same range as that of the ink composition according to the first embodiment described above. By having the total content within this range, continuous ejection stability, clogging recovery, storage stability, and color development tend to be further improved, which is preferable.

[0053] The total content of the vegetable oil-derived carbon black and the recycled raw material-derived carbon black relative to the total amount of the ink composition may be in the same range as that of the ink composition according to the first embodiment described above. By having the total content in this range, continuous ejection stability, clogging recovery properties, storage stability, and color development properties tend to be further improved, which is preferable.

[0054] The content of petroleum-derived carbon black relative to the total amount of the inkjet ink composition may be in the same range as that of the ink composition according to the first embodiment described above. By having the content of petroleum-derived carbon black in this range, continuous ejection stability, clogging recovery properties, storage stability, and color development properties tend to be further improved, which is preferable.

[0055] The content of petroleum-derived carbon black relative to the total content of vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black may be in the same range as that of the ink composition according to the first embodiment described above. By having the content within this range, continuous ejection stability, clogging recovery properties, storage stability, and color development properties tend to be further improved, which is preferable.

[0056] The total content of the vegetable oil-derived carbon black, recycled raw material-derived carbon black, and petroleum-derived carbon black relative to the total amount of the inkjet ink composition may be in the same range as that of the ink composition according to the first embodiment described above. By having the total content in this range, continuous ejection stability, clogging recovery properties, storage stability, and color development properties tend to be further improved, which is preferable.

[0057] The pigment contained in the ink composition of the second embodiment may further have the same configuration as the pigment contained in the ink composition of the first embodiment described above.

[0058] 2.1.2.Surfactants The surfactants in the second embodiment 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. The inclusion of such surfactants effectively increases the wettability of the highly hydrophobic and less hydrophobic portions of the carbon black, which tends to further improve storage stability, continuous discharge stability, clogging recovery, and the like.

[0059] 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 is 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.)

[0060] 2.1.2.1. Surfactant A Surfactant A mainly increases the wettability of the less hydrophobic portions of petroleum-derived carbon black, and also increases the wettability of the less hydrophobic portions of vegetable oil-derived carbon black and recycled raw material-derived carbon black, promotes the removal of air bubbles, and can maintain good discharge stability, clogging recovery, and the like, even when a container in which dissolved nitrogen increases over time is used.

[0061] 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 and acetylene glycol surfactants. Surfactant A may be a commercially available product, such as KF-640 or KF-6013 (silicone surfactants, manufactured by Shin-Etsu Silicones Co., Ltd.), or E1010 or EXP4200 (acetylene glycol surfactants, manufactured by Nissin Chemical Industry Co., Ltd.).

[0062] Among these, one or more selected from the group consisting of silicone surfactants and acetylene glycol surfactants are preferred, with acetylene glycol surfactants being more preferred. Use of such surfactant A tends to further improve storage stability and continuous ejection stability. In addition, acetylene glycol surfactants are less likely to foam and, because they have a carbon skeleton similar to carbon black, tend to have high affinity with carbon black and high bubble removal efficiency.

[0063] The HLB value of surfactant A is 10 or more and less than 15, preferably 11 or more and 14.5 or less, and more preferably 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.

[0064] 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.).

[0065] 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.).

[0066] 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.

[0067] The content of surfactant A is preferably 0.05% 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 inkjet ink composition. When the content of surfactant A is within the above range, continuous ejection stability and storage stability tend to be further improved.

[0068] 2.1.2.2. Surfactant B Surfactant B is an acetylene glycol-based surfactant with an HLB value of 3 or more but less than 10. The use of an acetylene glycol-based surfactant with an HLB value of 3 or more but less than 10 can increase the wettability of the highly hydrophobic portions of carbon black, mainly those derived from vegetable oil or recycled materials, and promote the removal of air bubbles, thereby maintaining good discharge stability. In addition, because acetylene glycol-based surfactants are less likely to foam and have the same carbon skeleton as carbon black, they are thought to have a higher affinity and higher air bubble removal efficiency than other surfactants.

[0069] The surfactant B is not particularly limited as long as it is an acetylene glycol surfactant having an HLB value of 3 or more and less than 10, and examples of commercially available surfactants include Surfynol SE, Surfynol 440, and Surfynol 104 (product names, manufactured by Nissin Chemical Industry Co., Ltd.).

[0070] 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.

[0071] 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.

[0072] 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 6.5 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.

[0073] The content of surfactant B is preferably 0.05% by mass to 1.5% by mass, 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 inkjet ink composition. When the content of surfactant B is within the above range, continuous ejection stability and storage stability tend to be further improved.

[0074] The mass ratio (B / A) of the content of surfactant B to the content of surfactant A is preferably 0.01 or more and 2.0 or less, 0.1 or more and 1.0 or less, 0.2 or more and 0.9 or less, 0.3 or more and 0.8 or less, or 0.4 or more and 0.7 or less. By setting the mass ratio of the content of surfactant B to the content of surfactant A within the above range, continuous ejection stability and storage stability tend to be further improved.

[0075] 2.1.2.3. Other surfactants

[0076] The other surfactants are not particularly limited, but examples thereof include silicone surfactants, acetylene glycol surfactants, and fluorine surfactants.

[0077] Examples of silicone surfactants include polysiloxane compounds and polyether-modified organosiloxanes.

[0078] The acetylene glycol surfactant is not particularly limited, and examples thereof include one or more surfactants selected from the group consisting of 2,4,7,9-tetramethyl-5-decyne-4,7-diol, alkylene oxide adducts of 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and alkylene oxide adducts of 2,4-dimethyl-5-decyne-4-ol and 2,4-dimethyl-5-decyne-4-ol. Among the examples listed above, surfactants that do not fall under the aforementioned surfactant A and surfactant B are other surfactants.

[0079] The content of the other surfactant 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 inkjet ink composition. The other surfactant may not be included. By setting the content of the other surfactant within the above range, continuous ejection stability and storage stability tend to be further improved.

[0080] The total content of the surfactants is preferably 0.05 to 5 mass%, 0.1 to 2 mass%, 0.2 to 1.5 mass%, or 0.7 to 1.2 mass%, relative to the total amount of the ink-jet ink composition. By keeping the total content of the surfactants within the above range, continuous ejection stability, clogging recovery property, and storage stability tend to be further improved.

[0081] Hereinafter, the components of the inkjet ink composition according to the first and second embodiments other than those described above will be described.

[0082] 3.1.Surfactants The surfactant in the inkjet ink composition of the second embodiment is as described above.

[0083] The inkjet ink composition according to the first embodiment may contain a surfactant. By containing a surfactant, storage stability tends to be further improved.

[0084] The surfactant is not particularly limited, but examples thereof include silicone surfactants, acetylene glycol surfactants, and fluorine surfactants. The surfactants may be used alone or in combination of two or more.

[0085] The surfactant may be the same as the surfactant contained or may be contained in the ink composition of the second embodiment described above, and for example, surfactant A, surfactant B, and other surfactants may also be contained, which is preferable.

[0086] 3.2. Organic Solvents The inkjet ink composition in the first and second embodiments may contain an organic solvent. By containing an organic solvent, the storage stability, clogging recovery property, continuous ejection stability, etc. of the inkjet ink composition tend to be further improved.

[0087] Examples of the organic solvent include water-soluble organic solvents such as polyols, glycol ethers, etc. The organic solvents may be used alone or in combination of two or more.

[0088] 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.

[0089] The polyols are compounds having two or more hydroxyl groups in the molecule, and preferred examples thereof include alkanediols, condensates in which hydroxyl groups of alkanediol molecules are condensed together, and triols.

[0090] Furthermore, preferred examples of alkanediols and condensates of alkanediols in which intermolecular hydroxyl groups are condensed together include diols of alkanes having 4 or less carbon atoms and condensates of intermolecular hydroxyl groups of diols of alkanes having 4 or less carbon atoms. The number of carbon atoms in these is more preferably 2 to 3.

[0091] Alternatively, the alkanediol is preferably, for example, a diol of an alkane having 5 to 10 carbon atoms. A diol of an alkane having 6 to 8 carbon atoms is more preferred. Furthermore, 1,2-alkanediol is preferred.

[0092] As the triols, for example, triols of alkanes having 3 to 5 carbon atoms are preferred.

[0093] 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.

[0094] Among the organic solvents, the inkjet ink composition of the first embodiment is 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: 3 ) 1 / 2 By including organic solvent C having an SP value of 14 (cal / cm or more), the compatibility of the components contained in the ink composition is improved, and the storage stability and continuous ejection stability of the ink composition tend to be further improved. On the other hand, when the SP value of organic solvent C is 14 (cal / cm or more), the ink composition tends to have a high viscosity. 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 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 the continuous ejection stability to be further improved even in such a state.

[0095] 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, δ d 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.)

[0096] 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 the first embodiment, the SP value can be a value derived using the calculation software HSPiP.

[0097] The unit of the SP value in the 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:

[0098] 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 following is the result.

[0099] The content of organic solvent C is preferably 1 to 15 mass %, 2 to 9 mass %, 3 to 8 mass %, or 4 to 7 mass % relative to the total amount of the inkjet ink composition. By keeping the content of organic solvent C within the above range, storage stability, continuous ejection stability, clogging recovery ability, etc. tend to be further improved.

[0100] The organic solvent C is preferably a polyol or a glycol ether, and more preferably an alkanediol.

[0101] The mass ratio (B / C) of the content of surfactant B to the content of organic solvent C is preferably 0.8 or less, 0.6 or less, 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 organic solvent C within the above range, continuous ejection stability and storage stability tend to be further improved.

[0102] The content of the organic solvent, relative to the total amount of the inkjet ink composition, is preferably 3 to 50 mass%, 5 to 40 mass%, 10 to 30 mass%, 15 to 25 mass%, or 17 to 22 mass%, or preferably 12 to 20 mass%, and more preferably 13 to 17 mass%. By keeping the content of the organic solvent within the above range, storage stability and continuous ejection stability tend to be further improved.

[0103] Among the organic solvents, organic solvents having a normal boiling point of 160°C or higher are preferred, and those having a normal boiling point of 170 to 350°C, 180 to 300°C, 190 to 250°C, or 200 to 230°C are more preferred.

[0104] It is also preferable that the ink contains an organic solvent having a normal boiling point of 280° C. or higher, and it is preferable that the ink contains 5 to 20% by mass of an organic solvent having a normal boiling point of 280° C. or higher.

[0105] The organic solvent may contain other organic solvents. Examples of other organic solvents include, but are not limited to, those other than polyols and glycol ethers. The content of the other organic solvents is preferably 0 to 20% by mass, 1 to 15% by mass, or 3 to 10% by mass, relative to the total amount of the inkjet ink composition. By keeping the content of the other organic solvent within the above ranges, storage stability and clogging recovery tend to be further improved.

[0106] 3.3. pH adjuster The inkjet ink compositions of the first and second embodiments may contain a pH adjuster, if necessary. Examples of pH adjusters include inorganic acids (e.g., sulfuric acid, hydrochloric acid, nitric acid, etc.), inorganic bases (e.g., lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia, etc.), organic acids (e.g., adipic acid, citric acid, succinic acid, etc.), and organic bases (triethanolamine, diethanolamine, monoethanolamine, triisopropanolamine, diisopropanolamine, trishydroxymethylaminomethane). One pH adjuster may be used alone, or two or more may be used in combination.

[0107] The content of the pH adjuster relative to the total amount of the inkjet ink composition is preferably 0.01 to 5 mass%, 0.05 to 3 mass%, 0.1 to 1 mass%, or 0.3 to 0.8 mass%. By setting the content of the pH adjuster within the above range, storage stability and continuous ejection stability tend to be further improved.

[0108] 3.4.Water The inkjet ink compositions of the first and second embodiments are water-based inks containing water. A water-based inkjet ink composition is an inkjet ink composition that contains at least water as the main solvent component of the ink.

[0109] The water content is preferably 40 to 99 mass%, 50 to 98 mass%, 60 to 95 mass%, 65 to 85 mass%, 70 to 80 mass%, or 75 to 79 mass% relative to the total amount of the ink-jet ink composition. By keeping the water content within the above range, storage stability and continuous ejection stability tend to be further improved.

[0110] 3.5.Other Ingredients The ink composition may contain components other than those described above, such as a dissolution aid, a viscosity adjuster, an antioxidant, a preservative, an antifungal agent, and a corrosion inhibitor.

[0111] 3.6. Recording Media The recording medium used in the first and second embodiments is not particularly limited, and examples thereof include absorbent recording media, low absorbent recording media, and non-absorbent recording media.

[0112] Among these, absorbent recording media are preferred, as the color development tends to be further improved by using the absorbent recording media.

[0113] 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)).

[0114] 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.

[0115] Examples of non-absorbent recording media include films and plates of plastics such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate, polystyrene, polyurethane, etc.; plates of metals such as iron, silver, copper, aluminum, etc.; 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, polyurethane, etc. is adhered (coated) to a paper substrate.

[0116] Here, the "absorbent recording medium" is defined as a recording medium having a water absorption rate of 10 mL / m2 within 30 msec from the start of contact in the Bristow method. 2 "Low-absorbency recording media and non-absorbency recording media" refers to media with a water absorption rate of 10 mL / m or more. 2 This refers to a recording medium that is as follows: The Bristow method is the most widely used method for measuring liquid absorption in a short period of time, and is also adopted by the Japan Pulp and Paper Technical Association (JAPAN TAPPI). Details of the test method are described in Standard No. 51 "Paper and Paperboard - Liquid Absorbency Test Method - Bristow Method" of the "JAPAN TAPPI Paper and Pulp Test Method 2000 Edition."

[0117] 4. Ink container The ink container according to the first and second embodiments is an ink container containing the ink composition according to the first or second embodiment described above, and includes the inkjet ink composition according to the first or second embodiment and a container containing the inkjet ink composition. Note that in the first and second embodiments, the ink container refers to a state in which the container contains ink.

[0118] The dissolved nitrogen concentration in the ink composition contained in the ink container is preferably 2 ppm to 100 ppm, 3 ppm to 50 ppm, 4 ppm to 10 ppm, or 5 ppm to 8 ppm. As the nitrogen concentration in the ink increases, carbon black derived from vegetable oil or carbon black derived from recycled materials, which have many voids, tends to absorb nitrogen, making the effect of the second embodiment more pronounced. The dissolved nitrogen concentration of the ink may be below a predetermined value when the ink container is shipped, or may increase to above the predetermined value after shipping and before use in the printer.

[0119] 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.

[0120] 4.1. 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.

[0121] The capacity of the container is preferably 20 ml or more, 80 ml or more, 100 ml or more, or 150 ml or more. It is also preferably 5 liters or less, 1 liter or less, 500 ml or less, or 300 ml or less. If the capacity is above the above range, it can hold a large amount of ink and is useful, but the size and weight of the container increase, making the strength and flexibility of the container components more important. If the capacity is below the above range, excessive increases in size and weight of the container can be avoided, which is preferable.

[0122] 4.1.1.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.

[0123] The resin constituting the resin film substrate layer is not particularly limited, but examples thereof include polyester resins and polyolefin resins.

[0124] The gas barrier layer is not particularly limited, but examples thereof include a resin layer with excellent gas barrier properties, a vapor-deposited layer of a metal or metal compound, a layer with a metal foil layer attached, etc. Note that a layer with a metal foil layer attached, such as an aluminum foil layer, has higher gas barrier properties and is less likely to have a high dissolved nitrogen concentration even after long-term storage.

[0125] On the other hand, gas barrier layers using resin layers or vapor-deposited layers of metals or metal compounds are useful because they are tear-resistant and have excellent flexibility. However, because their gas barrier properties are slightly lower than those of metal foil layers, the dissolved nitrogen concentration is likely to increase during storage. Even if the dissolved nitrogen concentration is low immediately after ink is poured into the ink container, it is highly likely that the dissolved nitrogen concentration will increase during use, making the present invention particularly useful.

[0126] 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.

[0127] A gas barrier layer using a vapor-deposited layer of a metal or metal compound is useful because it is thinner and more flexible than a metal foil. The vapor-deposited layer of a metal or metal compound is not particularly limited, but examples thereof include vapor-deposited layers of aluminum, alumina, silica, etc.

[0128] Although the ink pack having the above-described multilayer structure has a gas barrier layer and is therefore less likely to have a high dissolved nitrogen concentration even after long-term storage, there are cases in which the gas barrier properties are limited in order to ensure the flexibility of the ink pack. Therefore, there is a high possibility that the dissolved nitrogen concentration will easily increase, and this embodiment is particularly useful. In particular, it is particularly useful to use the ink container of the second embodiment.

[0129] 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.

[0130] 4.1.2.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.

[0131] The ink bottle is preferably a resin bottle, which is advantageous in terms of lightness and cost, and 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.

[0132] 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 the second embodiment.

[0133] FIG. 6 shows an example of an ink bottle as a container according to this embodiment. FIG. 6 is a cross-sectional view of the ink bottle. The ink bottle 63 contains the ink composition IK described above. 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 storing the ink bottle 63, a cylindrical cap 79 with a bottom covers a portion 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 with and secure a helical thread 82 formed on the outer surface of the container body 64. When flowing ink, the cap 79 is removed.

[0134] The container body 64 of the ink bottle 63 is a bottle-shaped member capable of containing an ink composition therein.

[0135] 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.

[0136] 5. Inkjet recording method The inkjet recording method according to the first and second embodiments includes a step of ejecting the inkjet ink composition from a predetermined inkjet head and depositing it onto a recording medium.

[0137] 6. Inkjet recording device The inkjet recording apparatus according to the first and second embodiments includes the ink composition described above, an inkjet head having nozzles for ejecting the ink composition onto a recording medium, a supply flow path connected to the inkjet head and through which the ink composition flows, and a filter unit provided in the supply flow path of the inkjet head.

[0138] The ink supply device further has a mounting portion (not shown) to which an ink container is mounted, 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.

[0139] An example of an inkjet recording apparatus that can be used in the first and second embodiments is shown in Figure 4. The inkjet recording apparatuses according to the first and second embodiments will be described in further detail with reference to Figure 4. In the XYZ coordinate system shown in Figure 4, the X direction indicates the length direction of the recording medium, the Y direction indicates the width direction of the recording medium on the transport path within the recording apparatus, and the Z direction indicates the height direction of the apparatus.

[0140] 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.

[0141] 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 the recording media P stored in the feeding tray 30 to the transport path 11.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 initial recorded side faces the inkjet head 48.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 7. Recordings The recorded matter of the first and second embodiments is obtained by applying the ink composition described above to a recording medium. The recorded matter of the first embodiment using the ink composition described above can be recorded with ink that is excellent in color development, storage stability, clogging recovery property, and continuous ejection stability. [Example]

[0156] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples.

[0157] 1. Preparation of Ink Composition Each component was placed in a mixing tank, mixed and stirred, and filtered through a membrane filter to obtain the inkjet ink composition shown in Tables 1, 2, and 3. The numerical values ​​for each component shown in each example in the tables represent mass % unless otherwise specified. Furthermore, each numerical value in the tables represents the mass % of the solid content of the component. This represents the net amount of each component, including liquid components such as organic solvents. In the tables, "Vegetable Oil CB" represents vegetable oil-derived carbon black, "Petroleum CB" represents petroleum-derived carbon black, and "Vegetable Charcoal CB" represents vegetable charcoal-derived carbon black.

[0158] The abbreviations and product ingredients used in Tables 1, 2 and 3 are detailed below.

[0159] [Carbon black dispersion] CB dispersion 1 to 10 (see the preparation example below) [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) [pH adjuster] Triethanolamine [water] Ion-exchanged water

[0160] <Adjustment example 1: CB dispersion 1> Carbon black 1 (vegetable oil-derived carbon black (PRINTEX Nature, manufactured by Orion Engineered Carbons Co., Ltd.) BET specific surface area: 90 m 2 Water is added to the carbon black (15% by mass) and an aqueous solution of sodium hypochlorite is added dropwise while the carbon black is being pulverized to produce a reaction solution containing self-dispersible carbon black. After filtration, the pH is adjusted and the carbon black is purified to obtain CB Dispersion 1, which is a 15% by mass self-dispersible carbon black. The above treatment oxidizes the pigment surface, introducing carboxyl groups onto the pigment surface, resulting in self-dispersible carbon black.

[0161] <Adjustment examples 2-5: CB dispersion 2-5> Vegetable oil-derived carbon blacks 2 to 5 are produced using wood tar (manufactured by Nara Tanka Kogyo Co., Ltd.) by the furnace method. Fuel is burned to generate high-temperature combustion gas, generating a combustion gas flow. Next, the raw material (wood tar) is introduced into the combustion gas flow, and the vegetable oil is converted into carbon black through incomplete combustion and thermal decomposition reactions. The lower the temperature of the combustion gas flow into which the raw material is introduced, the smaller the BET specific surface area, so the desired specific surface area can be achieved by adjusting the temperature of the combustion gas flow. The BET specific surface areas of carbon blacks 2 to 5 are as follows: BET specific surface area of ​​carbon black 2: 90m 2 / g BET specific surface area of ​​Carbon Black 3: 70m 2 / g BET specific surface area of ​​carbon black 4: 30m 2 / g BET specific surface area of ​​Carbon Black 5: 130m 2 / g

[0162] Water is added to Carbon Black 2, and while pulverizing, an aqueous sodium hypochlorite solution is added dropwise to produce a reaction liquid containing an aqueous self-dispersed carbon black solution. After filtration, the pH is adjusted, and purification is carried out to obtain CB Dispersion 2, which is a 15% by mass self-dispersed solution. CB Dispersions 3 to 5 are also prepared in the same manner using Carbon Blacks 3 to 5, respectively.

[0163] <Adjustment example 6: CB dispersion liquid 6> Carbon black 6 (petroleum-derived carbon black (#850, manufactured by Mitsubishi Chemical Corporation), BET specific surface area: 220 m 2 Water is added to the mixture (1 / g), and while grinding, an aqueous solution of sodium hypochlorite is added dropwise to produce a reaction solution containing an aqueous solution of self-dispersed carbon black. After filtration, the pH is adjusted, and purification is carried out to obtain CB Dispersion 6, which is 15% by mass of self-dispersed carbon black.

[0164] <Adjustment example 7: CB dispersion 7> Carbon black 7 (petroleum-derived carbon black (#980, manufactured by Mitsubishi Chemical Corporation), BET specific surface area: 260 m 2 Water is added to the mixture (1 / g), and while grinding, an aqueous solution of sodium hypochlorite is added dropwise to produce a reaction solution containing an aqueous solution of self-dispersed carbon black. After filtration, the pH is adjusted, and purification is carried out to obtain CB Dispersion 7, which is 15% by mass of self-dispersed carbon black.

[0165] <Adjustment example 8: CB dispersion liquid 8> Carbon black 8 (petroleum-derived carbon black (#52, manufactured by Mitsubishi Chemical Corporation), BET specific surface area: 88 m 2 Water is added to the mixture (1 / g), and while grinding, an aqueous solution of sodium hypochlorite is added dropwise to produce a reaction solution containing an aqueous solution of self-dispersed carbon black. After filtration, the pH is adjusted, and purification is carried out to obtain CB Dispersion 8, which is 15% by mass of self-dispersed carbon black.

[0166] <Adjustment example 9: CB dispersion 9> Carbon black 9 (petroleum-derived carbon black (#2300, manufactured by Mitsubishi Chemical Corporation), BET specific surface area: 320 m 2 Water is added to the mixture (1 / g), and while grinding, an aqueous solution of sodium hypochlorite is added dropwise to produce a reaction solution containing an aqueous solution of self-dispersed carbon black. After filtration, the pH is adjusted, and purification is carried out to obtain CB Dispersion 9, which is 15% by mass of self-dispersed carbon black.

[0167] <Adjustment example 10: CB dispersion liquid 10> Carbon black 10 (plant-derived carbon black (Kiriya Chemical Co., Ltd., Kishu Binchotan powder), BET specific surface area: 220 m 2 Water is added to the mixture (1 / g), and while grinding, an aqueous solution of sodium hypochlorite is added dropwise to produce a reaction solution containing an aqueous solution of self-dispersed carbon black. After filtration, the pH is adjusted, and purification is carried out to obtain CB dispersion 10, which is 15% by mass of self-dispersed carbon black.

[0168] 2. Ink container <s1> A multilayer film is prepared by depositing 30 nm of aluminum on one side of an 80 μm thick low-density polyethylene (PE) film. The resulting film is then used to prepare an ink pack (hereinafter referred to as "S1") for containing the ink composition.

[0169] <s2> A multilayer film is 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 obtained film, an ink pack (hereinafter referred to as "S2") for containing an ink composition is prepared.

[0170] <s3> Ink bottles (hereinafter referred to as "S3") are made using polyethylene by stretch blow molding. The volume of each bottle is 150 ml.

[0171] 2.1. Dissolved nitrogen content The inkjet ink composition prepared as described above is filled into each of the containers to produce a container. One year after filling, the amount of dissolved nitrogen in the ink in the container is measured in mass terms using a gas chromatograph 6890N (trade name, manufactured by Agilent). However, for Reference Example 7, the measurement is performed immediately after filling.

[0172] 3. Evaluation Method 3.1.Color development A container filled with the inkjet ink composition prepared as described above is attached to a modified inkjet printer PX-H6000 (manufactured by Seiko Epson Corporation), and ink is supplied to the inkjet head. In the case where the ink container is S3, a CISS tank is attached to the recording device and the CISS tank is filled with ink from the ink container. Seiko Epson Corporation's plain business paper "KA450BZ" (A4 size) was set, a JEITA CP3901B pattern was formed, and the color was measured using an i1 (X-Rite). The printer was set without color correction. The black color development was evaluated as shown below based on the optical density (OD value) of the maximum black duty. (Evaluation criteria) A:OD value is 1.20 or more B: OD value is 1.15 or more and less than 1.20 C:OD value is 1.10 or more and less than 1.15 D:OD value is less than 1.10

[0173] 3.2. Storage stability Each ink composition was placed in a 50 cc glass sample bottle and sealed. These glass bottles were then placed in a thermostatic chamber at 50°C and left in that environment for 10 days. The temperature was 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 10 days of storage in the sample bottle was calculated, relative to the initial viscosity of the ink composition before it was sealed in the sample bottle. The evaluation criteria were as follows: For Reference Example 7, the rate of viscosity change was measured for ink that had not been stored. (Evaluation criteria) A: Viscosity change rate is less than ±5% B: Viscosity change rate is between ±5% and 8% C: Viscosity change rate is between ±8% and 11% D: Viscosity change rate is ±11% or more

[0174] 3.3.Continuous Discharge Stability A recording device prepared in the same manner as in the color development test above was filled with the inkjet ink composition contained in a container that had been used for the above dissolved nitrogen amount one year after filling, and FUJI XEROX printer paper "P" (A4 size) was set on the device, followed by continuous printing 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. For Reference Example 7, a container immediately after filling was used. The evaluation was carried out according to the following criteria, and the results are shown in the table. (Evaluation criteria) A: More than 100 sheets can be printed normally. B: Prints normally in the range of 50 to 100 sheets. C: Prints normally in the range of 5 to 50 sheets. D: Missing or deflection occurs when there are less than 5 sheets.

[0175] 3.4.Clogging recovery An ink container and recording device prepared in the same manner as for the continuous ejection stability test described above are used. All rows of the print head of the recording device are filled with ink, and normal ejection is confirmed for all rows. The print head is 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 it, the print head is returned to its standby position, and the nozzle surface is wiped using a rubber wiper. A cleaning process is then performed, and the number of cleanings required until ejection is restored for all nozzles is 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 or more cleanings.

[0176] 4. Evaluation Results Each table shows the composition of the ink used in each example, as well as the evaluation results. From the tables, it can be seen that the ink contains vegetable oil-derived carbon black and petroleum-derived carbon black, and the BET specific surface area of ​​the vegetable oil-derived carbon black and / or the recycled raw material-derived carbon black is 50 m 2 / g or more 120m 2 / g or less, and the BET specific surface area of ​​the petroleum-derived carbon black is 160 m 2 / g or more 280m 2 Examples 1 to 31 and 36 to 42, which used ink compositions with a solubility of 1 / g or less, all exhibited excellent color development and storage stability.

[0177] In contrast, Reference Examples 1 to 7 and Examples 32 to 35, which do not contain at least one of vegetable oil-derived carbon black and petroleum-derived carbon black and have the above BET specific surface areas, are all inferior in either color development or storage stability.

[0178] Furthermore, from the table, it can be seen that Examples 1 to 35, which used inkjet ink compositions containing vegetable oil-derived carbon black and petroleum-derived carbon black, surfactant A having an HLB value of 10 or more and less than 15, and surfactant B, an acetylene glycol-based surfactant having an HLB value of 3 or more and less than 10, all exhibited excellent continuous ejection stability and clogging recovery properties.

[0179] In contrast, Examples 36 to 42, which contain vegetable oil-derived carbon black and petroleum-derived carbon black but do not contain either surfactant A or surfactant B, all have poor continuous discharge stability and clogging recovery properties.

[0180] Furthermore, Reference Example 5, which does not contain vegetable oil-derived carbon black and does not contain surfactant B, is not inferior in continuous discharge stability or clogging recovery performance. This demonstrates that surfactant B is necessary when vegetable oil-derived carbon black is contained.

[0181] Furthermore, Reference Example 7 has a lower amount of dissolved nitrogen than Reference Example 6, and is good in continuous discharge stability and clogging recovery. This shows that a higher amount of dissolved nitrogen reduces continuous discharge stability and clogging recovery.

[0182] Furthermore, Reference Examples 3 and 4, which contain vegetable charcoal as a pigment, are inferior in color development, continuous discharge, and clogging recovery.

[0183] Furthermore, although not shown in the table, a film was produced as container S4 by attaching a 10 μm thick aluminum foil layer to one side of an 80 μm thick low-density polyethylene (PE) film, and the resulting film was used to produce an ink pack in the same manner.When an ink container was produced in the same manner as in Example 1 except for using this container, the amount of dissolved nitrogen was 3 ppm even after a period of one year, which shows that the amount of dissolved nitrogen is unlikely to increase with such a container. [Explanation of symbols]

[0184] 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 pigment, The pigment comprises vegetable oil-derived carbon black and / or recycled raw material-derived carbon black, and petroleum-derived carbon black; The BET specific surface area of ​​the vegetable oil-derived carbon black and / or the recycled raw material-derived carbon black is 50 m 2 / g or more 120m 2 / g or less, The BET specific surface area of ​​the petroleum-derived carbon black is 160 m 2 / g or more 280m 2 / g or less, It is a water-based ink, Inkjet ink composition.

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

3. the total content of the vegetable oil-derived carbon black and / or the recycled raw material-derived carbon black is 20% by mass or more and 40% by mass or less based on the total amount of the vegetable oil-derived carbon black, the recycled raw material-derived carbon black, and the petroleum-derived carbon black; The ink-jet ink composition according to claim 1 or 2.

4. the total content of the vegetable oil-derived carbon black, the recycled raw material-derived carbon black, and the petroleum-derived carbon black is 4% by mass or more and 8% by mass or less with respect to the total amount of the inkjet ink composition; The ink-jet ink composition according to claim 1 or 2.

5. The vegetable oil-derived carbon black and / or recycled material-derived carbon black, and the petroleum-derived carbon black contain self-dispersing pigments. The ink-jet ink composition according to claim 1 or 2.

6. It is used by attaching it to an absorbent recording medium. The ink-jet ink composition according to claim 1 or 2.

7. 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 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 2.

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

10. the content of the organic solvent C is 1% 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 9.

11. 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 9.

12. The surfactant A includes a silicone surfactant and / or an acetylene glycol surfactant. The ink-jet ink composition of claim 2.

13. A method for producing an ink jet recording medium, comprising a step of ejecting the ink jet ink composition according to claim 1 or 2 from an ink jet head and depositing the ink jet ink composition on a recording medium. Recording method.

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