Patent Application
20250026947
The present disclosure relates to an aqueous ink, an ink jet recording method, an ink jet recording device, and an ink storage container.
Examples of an aqueous ink for ink jet recording include an ink described in JP2008-239733A. The ink described in JP2008-239733A contains a chemically synthesized product as a preservative.
According to an aspect of the present disclosure, an aqueous ink includes: water; a water-soluble organic solvent; a coloring agent; and lignosulfonic acid or a salt thereof. The coloring agent is at least one selected from the group consisting of a self-dispersed pigment, a resin dispersion pigment, and a water-soluble dye.
According to another aspect of the present disclosure, an ink jet recording method includes ejecting the aqueous ink to a recording medium for recording by an ink jet method.
According to a further aspect of the present disclosure, an ink jet recording device includes an ink storage unit comprising the aqueous ink; and an ink ejection unit configured to eject the aqueous ink.
According to a further aspect of the present disclosure, an ink storage container includes the aqueous ink.
FIGURE is a schematic perspective view showing a configuration of an example of an ink jet recording device according to the present disclosure.
In recent years, as environmental issues have become a major concern, environmentally friendly products have become more widespread, and there is a demand for an aqueous ink for ink jet recording having less environmental impact. Therefore, there is a demand for an aqueous ink for ink jet recording that contains a component containing a raw material derived from a natural material having low environmental impact.
An aqueous ink for ink jet recording according to the embodiment of the present disclosure contains: water; a water-soluble organic solvent; a coloring agent; and lignosulfonic acid or a salt thereof, in which the coloring agent is at least one of a self-dispersed pigment, a resin dispersion pigment, and a water-soluble dye.
After investigating a preservative derived from a natural material, the inventor of the present disclosure has presumed that lignosulfonic acid or a salt thereof has a preservative effect due to a chemical structure thereof, and based on this presumption, has conceived of blending lignosulfonic acid or a salt thereof in an inkjet ink. Accordingly, it has been found that when lignosulfonic acid or a salt thereof is used as a preservative in the inkjet ink, a preservative effect is exhibited on the ink. In this way, the inventor of the present disclosure is the first to find that lignosulfonic acid or a salt thereof can be used as a preservative for the inkjet ink. In this way, the aqueous ink for ink jet recording according to the present disclosure contains lignosulfonic acid or a salt thereof derived from a natural material, and therefore has preservability and can contribute to reducing environmental impact.
As used herein, the words “a” and “an” and the like carry the meaning of “one or more.” When an amount, concentration, or other value or parameter is given as a range, and/or its description includes a list of upper and lower values, this is to be understood as specifically disclosing all integers and fractions within the given range, and all ranges formed from any pair of any upper and lower values, regardless of whether subranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, as well as all integers and fractions within the range. As an example, a stated range of 1-10 fully describes and includes the independent subrange 3.4-7.2 as does the following list of values: 1, 4, 6, 10.
In the present disclosure, “mass” may be referred to as “weight” unless otherwise specified. For example, “mass ratio” may be referred to as “weight ratio” unless otherwise specified, and “mass %” may be referred to as “wt %” unless otherwise specified.
An aqueous ink for ink jet recording according to the present disclosure (hereinafter, sometimes referred to as an “aqueous ink” or an “ink”) will be described. The aqueous ink according to the present disclosure contains: water; a water-soluble organic solvent; a coloring agent; and lignosulfonic acid or a salt thereof, in which the coloring agent is at least one of a self-dispersed pigment, a resin dispersion pigment, and a water-soluble dye. Note that, in the ink according to the present disclosure, since the coloring agent is at least one of a self-dispersed pigment, a resin dispersion pigment, and a water-soluble dye, lignosulfonic acid or a salt thereof does not function as a dispersant for the coloring agent. In addition, lignosulfonic acid or a salt thereof may has not only a preservative effect but also, for example, an agglomerating effect (OD value increasing effect) for the coloring agent.
As the water-soluble organic solvent, a water-soluble organic solvent known in the related art can be used. The water-soluble organic solvent include is not particularly limited, and examples thereof include a polyhydric alcohol, a polyhydric alcohol derivative, an alcohol, an amide, a ketone, a ketoalcohol, an ether, a nitrogen-containing solvent, a sulfur-containing solvent, propylene carbonate, ethylene carbonate, and 1,3-dimethyl-2-imidazolidinone. Examples of the polyhydric alcohol include glycerin, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, hexylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylolpropane, 1,5-pentanediol, and 1,2,6-hexanetriol. Examples of the polyhydric alcohol derivative include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-n-butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol-n-propyl ether, diethylene glycol-n-butyl ether, diethylene glycol-n-hexyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol-n-propyl ether, triethylene glycol-n-butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol-n-propyl ether, propylene glycol-n-butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol-n-propyl ether, and tripropylene glycol-n-butyl ether. Examples of the alcohol include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, and benzyl alcohol. Examples of the amide include dimethylformamide and dimethylacetamide. Examples of the ketone include acetone. Examples of the ketoalcohol include diacetone alcohol. Examples of the ether include tetrahydrofuran and dioxane. Examples of the nitrogen-containing solvent include pyrrolidone, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, and triethanolamine. Examples of the sulfur-containing solvent include thiodiethanol, thiodiglycol, thiodiglycerol, sulfolane, and dimethyl sulfoxide. A blending amount of the water-soluble organic solvent with respect to a total amount of the treatment agent is not particularly limited. The water-soluble organic solvent may be used alone or in combination of two or more types thereof.
The self-dispersion type pigment can be dispersed in water without using a dispersant, for example, by introducing at least one of a hydrophilic functional group such as a carbonyl group, a hydroxy group, a carboxylic acid group, a sulfonic acid group, and a phosphoric acid group, and a salt thereof into pigment particles by chemical bonding, either directly or through other groups. As the self-dispersion type pigment, for example, pigments treated by methods described in JPH08-3498A, JP2000-513396A, JP2008-524400A, JP2009-515007A, and JP2011-515535A can be used. As a raw material of the self-dispersion type pigment, either an inorganic pigment or an organic pigment can be used. In addition, examples of the pigment suitable for the treatment include carbon black such as “MA8” and “MA100” manufactured by Mitsubishi Chemical Corporation. The self-dispersion type pigment may be, for example, a commercially available product. Examples of the commercially available product include: “CAB-O-JET (registered trademark) 200”, “CAB-O-JET (registered trademark) 250C”, “CAB-O-JET (registered trademark) 260M”, “CAB-O-JET (registered trademark) 270Y”, “CAB-O-JET (registered trademark) 300”, “CAB-O-JET (registered trademark) 400”, “CAB-O-JET (registered trademark) 450C”, “CAB-O-JET (registered trademark) 465M”, and “CAB-O-JET (registered trademark) 470Y” manufactured by Cabot Corporation; “BONJET (registered trademark) BLACK CW-2” and “BONJET (registered trademark) BLACK CW-3” manufactured by ORIENT CHEMICAL INDUSTRIES CO., LTD; and “LIOJET (registered trademark) WD BLACK 002C” manufactured by TOYO INK CO., LTD.
In the present disclosure, the “resin dispersion pigment” refers to a pigment in which a resin dispersant is adsorbed onto the surface of the pigment, thereby imparting dispersion stability to the pigment in a solvent or the like unless otherwise specified. As the resin dispersant, for example, a general polymer dispersant (also referred to as a resin for pigment dispersion or a resin dispersant) may be used, and the resin dispersant may be prepared. In addition, in the aqueous ink according to the present disclosure, the pigment may be encapsulated with a polymer. As the resin dispersant, for example, those containing at least one of methacrylic acid and acrylic acid as a monomer can be used, and for example, a commercially available product may be used. The resin dispersant may be, for example, a block copolymer, a graft copolymer, or a random copolymer made of hydrophobic monomers such as styrene, a styrene derivative, vinylnaphthalene, a vinylnaphthalene derivative, aliphatic alcohol esters of α,β-ethylenically unsaturated carboxylic acids, or two or more monomers selected from the group consisting of acrylic acid, an acrylic acid derivative, maleic acid, a maleic acid derivative, itaconic acid, an itaconic acid derivative, fumaric acid, and a fumaric acid derivative, or a salt thereof. Examples of the commercially available product include: “Joncryl (registered trademark) 611”, “Joncryl (registered trademark) 60”, “Joncryl (registered trademark) 586”, “Joncryl (registered trademark) 687”, “Joncryl (registered trademark) 63”, and “Joncryl (registered trademark) HPD296” manufactured by Johnson Polymer Co., Ltd.; “Disperbyk 190” and “Disperbyk 191” manufactured by BYK; and “Solsperse 20000” and “Solsperse 27000” manufactured by Zeneca Corporation.
Examples of a method for dispersing the pigment using the resin for pigment dispersion include dispersing the pigment using a dispersing device. The dispersing device used for dispersing the pigment is not particularly limited as long as the dispersing device is a general disperser, and examples thereof include a ball mill, a roll mill, and a sand mill (for example, a high-speed type sand mill).
The water-soluble dye is not particularly limited, and examples thereof include a direct dye, an acid dye, a basic dye, and a reactive dye. Specific examples of the water-soluble dye include C.I. Direct Black, C.I. Direct Blue, C.I. Direct Red, C.I. Direct Yellow, C.I. Direct Orange, C.I. Direct Violet, C.I. Direct Brown, C.I. Direct Green, C.I. Acid Black, C.I. Acid Blue, C.I. Acid Red, C.I. Acid Yellow, C.I. Acid Orange, C.I. Acid Violet, C.I. Basic Black, C.I. Basic Blue, C.I. Basic Red, C.I. Basic Violet, and C.I. Food Black. Examples of the C.I. Direct Black include C.I. Direct Black 17, 19, 32, 51, 71, 108, 146, 154, and 168. Examples of the C.I. Direct Blue include C.I. Direct Blue 6, 22, 25, 71, 86, 90, 106, and 199. Examples of the C.I. Direct Red include C.I. Direct Red 1, 4, 17, 28, 83, and 227. Examples of the C.I. Direct Yellow include C.I. Direct Yellow 12, 24, 26, 86, 98, 132, 142, and 173. Examples of the C.I. Direct Orange include C.I. Direct Orange 34, 39, 44, 46, and 60. Examples of the C.I. Direct Violet include C.I. Direct Violet 47 and 48. Examples of the C.I. Direct Brown include C.I. Direct Brown 109. Examples of the C.I. Direct Green include C.I. Direct Green 59. Examples of the C.I. Acid Black include C.I. Acid Black 2, 7, 24, 26, 31, 52, 63, 112, and 118. Examples of the C.I. Acid Blue include C.I. Acid Blue 9, 22, 40, 59, 90, 93, 102, 104, 117, 120, 167, 229, and 234. Examples of the C.I. Acid Red include C.I. Acid Red 1, 6, 32, 37, 51, 52, 80, 85, 87, 92, 94, 115, 180, 256, 289, 315, and 317. Examples of the C.I. Acid Yellow include C.I. Acid Yellow 11, 17, 23, 25, 29, 42, 61, and 71. Examples of the C.I. Acid Orange include C.I. Acid Orange 7 and 19. Examples of the C.I. Acid Violet include C.I. Acid Violet 49. Examples of the C.I. Basic Black include C.I. Basic Black 2. Examples of the C.I. Basic Blue include C.I. Basic Blue 1, 3, 5, 7, 9, 24, 25, 26, 28, and 29. Examples of the C.I. Basic Red include C.I. Basic Red 1, 2, 9, 12, 13, 14, and 37. Examples of the C.I. Basic Violet include C.I. Basic Violet 7, 14, and 27. Examples of the C.I. Food Black include C.I. Food Black 1 and 2.
The water-soluble dye has excellent properties such as clarity and stability. The water-soluble dye may be used alone or in combination of two or more types thereof.
A lignosulfonic acid salt in the lignosulfonic acid or a salt thereof (hereinafter, may be referred to as “lignosulfonic acid salt or the like”) is not particularly limited, and examples thereof include sodium lignosulfonate, calcium lignosulfonate, magnesium lignosulfonate, and ammonium lignosulfonate.
The aqueous ink according to the present disclosure may contain, for example, a component other than the lignosulfonic acid salt or the like as a preservative component. Examples of the component other than the lignosulfonic acid salt or the like include a naturally derived component other than the lignosulfonic acid salt or the like or a chemically synthesized component. These components may be used alone or in combination of two or more types thereof. From the viewpoint of environmental consideration, it is preferable to contain more naturally derived component than the chemically synthesized component, and it is more preferable to contain only the naturally derived component.
A blending amount of the lignosulfonic acid salt or the like with respect to a total amount of the aqueous ink is not particularly limited, may be, for example, 0.1 mass % or more, 0.2 mass % or more, 0.4 mass % or more, 0.5 mass % or more, 1.2 mass % or more, or 2.0 mass % or more, and 5.0 mass % or less, 4.5 mass % or less, 4.0 mass % or less, or 2.0 mass % or less, and is, for example, 0.1 mass % to 5.0 mass %, preferably 0.2 mass % to 5.0 mass %, and more preferably 0.2 mass % to 4.5 mass %.
When the pigment is contained as the coloring agent, the blending amount of the lignosulfonic acid salt or the like with respect to the total amount of the aqueous ink is, for example, 0.5 mass % to 4.5 mass %, preferably 1.2 mass % to 4.0 mass %, and more preferably 1.2 mass % to 2.0 mass %.
When the dye is contained as the coloring agent, the blending amount of the lignosulfonic acid salt or the like with respect to the total amount of the aqueous ink is, for example, 1.0 mass % to 5.0 mass %, preferably 1.0 mass % to 4.0 mass %, and more preferably 2.0 mass % to 4.0 mass %.
A mass ratio (A/C) of a content (A) of the pigment to a content (C) of the lignosulfonic acid or a salt thereof in the total amount of the aqueous ink for ink jet recording is not particularly limited, and is, for example, 1 to 9.5, preferably 2 to 9.5, and more preferably 2 to 5.
A mass ratio (B/C) of a content (B) of the dye to the content (C) of the lignosulfonic acid or a salt thereof in the total amount of the aqueous ink for ink jet recording is not particularly limited, and is, for example, 1 to 10, preferably 1 to 5, and more preferably 1 to 2.
The water may be ion exchange water, pure water, or the like. A blending amount (water proportion) of the water with respect to the total amount of the aqueous ink is appropriately determined according to desired ink properties and the like. The water proportion may be, for example, the balance except for other components. For example, the blending amount of the water is 50 mass % to 95 mass %, preferably 55 mass % to 90 mass %, and more preferably 60 mass % to 80 mass %.
The aqueous ink may further contain an additive known in the related art, if necessary. Examples of the additive include a pH adjuster, a viscosity modifier, a surface tension regulator, and an antifungal agent. Examples of the viscosity modifier include polyvinyl alcohol, cellulose, and a water-soluble resin.
Next, an ink storage container according to the present disclosure is an ink storage container containing an aqueous ink for ink jet recording, in which the aqueous ink is the aqueous ink for ink jet recording according to the present disclosure. As the ink storage container, for example, an ink storage container known in the related art can be used. Examples of the ink storage container include an ink cartridge, tank, and pouch.
Next, an ink jet recording device and an ink jet recording method according to the present disclosure will be described.
The ink jet recording device according to the present disclosure is an ink jet recording device including: an ink storage unit; and an ink ejection unit, in which an ink contained in the ink storage unit is ejected by the ink ejection unit, and the ink storage unit contains the aqueous ink for ink jet recording according to the present disclosure.
FIGURE shows a configuration of an example of the ink jet recording device according to the present disclosure. As shown in the FIGURE, an ink jet recording device 1 includes four ink storage units (ink cartridges 2), an ink ejection unit (ink jet head) 3, a head unit 4, a carriage 5, a drive unit 6, a platen roller 7, and a purge device 8 as main components.
The four ink cartridges 2 each contain one color of aqueous ink of four colors: yellow, magenta, cyan, and black. For example, at least one of the four color aqueous inks is the aqueous ink according to the present disclosure. In this example, a set of four ink cartridges 2 is shown, but instead of this, an integrated ink cartridge which is partitioned so as to form an aqueous yellow ink storage unit, an aqueous magenta ink storage unit, an aqueous cyan ink storage unit, and an aqueous black ink storage unit therein may be used. As a main body of the ink cartridge, for example, an ink cartridge known in the related art can be used.
The ink jet head 3 provided in the head unit 4 performs recording on a recording medium (for example, a recording sheet) P. The four ink cartridges 2 and the head unit 4 are mounted on the carriage 5. The drive unit 6 reciprocates the carriage 5 in a linear direction. As the drive unit 6, for example, a drive unit known in the related art can be used (see, for example, JP2008-246821A). The platen roller 7 extends in a reciprocating direction of the carriage 5 and is disposed in a manner of facing the ink jet head 3.
The ink jet head 3 is formed by stacking a plurality of thin plates made of a metal, for example. A through hole is formed in each of the thin plates. By stacking the plurality of thin plates in which the through hole is formed, a flow path for passing the aqueous ink is formed. The thin plates are bonded by, for example, an adhesive.
The purge device 8 suctions a defective ink containing air bubbles and the like accumulated in the ink jet head 3. As the purge device 8, for example, a purge device known in the related art can be used (see, for example, JP2008-246821A).
A wiper member 20 is disposed adjacent to the purge device 8 on a platen roller 7 side of the purge device 8. The wiper member 20 is formed in a spatula shape and wipes a nozzle forming surface of the ink jet head 3 as the carriage 5 moves. In FIGURE, a cap 18 covers a plurality of nozzles of the ink jet head 3 to be returned to a reset position when recording is completed in order to prevent drying of the aqueous ink.
In the ink jet recording device 1 in this example, the four ink cartridges 2 are mounted on one carriage 5 together with the head unit 4. However, the present invention is not limited thereto. In the ink jet recording device 1, each of the four ink cartridges 2 may be mounted on a carriage different from the head unit 4. In addition, each of the four ink cartridges 2 may be disposed and fixed in the ink jet recording device 1 without being mounted on the carriage 5. In these aspects, for example, each of the four ink cartridges 2 and the head unit 4 mounted on the carriage 5 are connected by a tube or the like, and the aqueous ink is supplied from each of the four ink cartridges 2 to the head unit 4. In addition, in these aspects, four ink bottles each having a bottle shape may be used instead of the four ink cartridges 2. In this case, it is preferable that the ink bottle is provided with an injection port for injecting the ink from an outside to an inside.
Ink jet recording using the ink jet recording device 1 is performed as follows, for example. First, the recording sheet P is fed from a sheet feeding cassette (not shown) provided on a lateral side or a lower side of the ink jet recording device 1. The recording sheet P is introduced between the ink jet head 3 and the platen roller 7. Predetermined recording is performed on the introduced recording sheet P with the aqueous ink ejected from the ink jet head 3. This ejection may be performed, for example, at a first ejection amount as described above, or may be performed at a second ejection amount when a specific condition is satisfied. The recording sheet P after the recording is discharged from the ink jet recording device 1. In FIGURE, a sheet feeding mechanism and a sheet discharging mechanism for the recording sheet P are not shown.
In the device shown in FIGURE, a serial type ink jet head is used, but the present invention is not limited thereto. The ink jet recording device may be a device using a line type ink jet head or roll to roll.
Next, an ink jet recording method according the present disclosure is an ink jet recording method including a recording step of performing recording by ejecting an aqueous ink to a recording medium by an ink jet method, in which in the recording step, as the aqueous ink, the aqueous ink for ink jet recording according to the present disclosure is used. The ink jet recording method according to the present disclosure can be performed by, for example, using the ink jet recording device according to the present disclosure. The recording includes printing words, printing an image, or printing.
Next, Examples of the present invention will be described together with Comparative Examples. Note that the present invention is not limited or restricted by the following Examples and Comparative Examples.
Pure water was added to 20 mass % of a pigment (carbon black) and 7 mass % of neutralized sodium hydroxide of a styrene-acrylic acid copolymer (acid value: 175 mgKOH/g, molecular weight: 10000) to make a total of 100 mass %, followed by stirring and mixing, to obtain a mixture. This mixture was charged into a wet sand mill filled with zirconia beads having a diameter of 0.3 mm and subjected to a dispersion treatment for 6 hours. Thereafter, the zirconia beads were removed using a separator, and the resultant was filtered through a cellulose acetate filter having a pore diameter of 3.0 μm to obtain a pigment dispersion liquid A. The styrene-acrylic acid copolymer is a water-soluble polymer that is generally used as a dispersant for pigments. Note that, in the pigment dispersion liquid A, a blending amount (A) of a pigment solid was 15 mass % with respect to a total amount of the pigment dispersion liquid A. In addition, in the pigment dispersion liquid A, carbon black as the pigment is dispersed in a styrene-acrylic acid copolymer as a resin dispersant.
The components in aqueous ink compositions (Tables 1 and 2) except for a coloring material (coloring agent) were mixed uniformly to obtain an ink solvent. Next, the coloring material was added to the ink solvent, followed by uniform mixing. Thereafter, the obtained mixture was filtered through a cellulose acetate type membrane filter (pore diameter: 3.00 μm) manufactured by TOYO ROSHI KAISHA, LTD. to obtain an aqueous ink for ink jet recording in each of Examples 1 to 14 and Comparative Examples 1 to 3 shown in Tables 1 and 2.
Regarding the aqueous inks in Examples 1 to 9 and Comparative Examples 1 and 2, (a) preservability, (b) optical density (OD value), (c) storage stability, and (d) ejection stability were evaluated by the following methods.
Regarding the aqueous inks in Examples 10 to 14 and Comparative Example 3, (a) preservability, (d) ejection stability, and (e) printing quality were evaluated by the following methods.
Note that, the lignosulfonic acid salt or the like used in the aqueous ink according to the present disclosure usually have a brownish color. Therefore, regarding the aqueous inks in Examples 1 to 9 and Comparative Examples 1 and 2 containing a black pigment as an example of an achromatic coloring material, since there was no change in color difference ΔE even when the black pigment was mixed with the lignosulfonic acid salt or the like, the optical density (OD value) was evaluated. On the other hand, regarding the aqueous inks in Examples 10 to 14 and Comparative Example 3 containing a color dye as an example of a chromatic coloring material, in order to check the change in color caused by mixing with the lignosulfonic acid salt or the like, the color difference ΔE (printing quality) was evaluated as described below.
The aqueous ink in each of Examples 1 to 14 and Comparative Examples 1 to 3 was applied to food stamp standard agar (manufactured by Nissui Pharmaceutical Co., Ltd.), followed by storage in an environment at a temperature of 35° C. Thereafter, the standard agar was visually inspected for the presence or absence of mold colonies, and the preservability was evaluated according to the following evaluation criteria.
Using an ink jet recording device DCP-J987N manufactured by Brother Industries, Ltd., an image was recorded on a recording sheet (“Copy Paper ASKUL Multi-Paper Super White+” manufactured by ASKUL Corporation) using the aqueous ink aqueous ink in each of Examples 1 to 9 and Comparative Examples 1 and 2 to prepare an evaluation sample. The optical density (OD value) at three locations in the evaluation sample was measured using a spectrophotometer SpectroEye (Light source: D50, viewing angle: 2°, ANSI-T) manufactured by X-Rite, and the average value was determined.
The aqueous ink of each of Examples and Comparative Examples immediately after preparation was placed in a sealed container and stored for 3 days in an environment at 60° C. After storage, the ink was observed under an optical microscope to check the presence or absence of aggregates.
Using an ink jet recording device DCP-J987N manufactured by Brother Industries, Ltd., a solid image was recorded on a recording sheet (“Copy Paper ASKUL Multi-Paper Super White +” manufactured by ASKUL Corporation) using the aqueous ink aqueous ink in each of Examples 1 to 9 and Comparative Examples 1 and 2 to prepare an evaluation sample. A lead chipping was evaluated according to the following evaluation criteria. Note that, the term “lead chipping” refers to a situation where the beginning of printing fails during solid printing, and the leading portion remains blank.
Using an ink jet recording device DCP-J987N manufactured by Brother Industries, Ltd., an image was recorded on a recording sheet (“Copy Paper ASKUL Multi-Paper Super White+” manufactured by ASKUL Corporation) using the aqueous ink aqueous ink in each of Examples 10 to 14 and Comparative Example 3 to prepare an evaluation sample. The colors (L*, a* and b*) at three locations in the evaluation sample were measured using a spectrophotometer SpectroEye (Light source: D50, viewing angle: 2°, ANSI-T) manufactured by X-Rite, and the average value was determined. L*, a*, and b* are based on the L*a*b* color system (CIE1976 (L*a*b*) color system) standardized by the International Commission on Illumination (CIE) in 1976 (see JIS Z 8729). The color difference (ΔE1) between the color of the evaluation sample of the recording sheet and the color of the evaluation sample of the cotton was calculated according to the following equation and evaluated according to the following evaluation criteria.
ΔE={(L*1−L*2)2+(a*1−a*2)2+(b*1−b*2)2}1/2
Here, L*1, a*1, and b*1 are the measurement results for Examples, and L*2, a*2, and b*2 are the measurement results for Comparative Example 3.
The aqueous ink composition and the evaluation result of the aqueous ink in each of Examples 1 to 14 and Comparative Examples 1 to 3 are shown in Tables 1 and 2.
As shown in Table 1, Examples 1 to 14 have evaluation results for the preservability of “B” or more. In addition, as shown in Examples 1, 2, 9, and 10, the preservability evaluation is good regardless of the difference in the lignosulfonic acid salt or the like. Further, as shown in Examples 1 to 14, regardless of whether the coloring agent contained in the aqueous ink is a pigment or a dye, the evaluation results for the preservability are all good.
In Examples 1 to 5, 7 to 8, and 10 to 12 in which the blending amount of the lignosulfonic acid salt or the like with respect to the total amount of the aqueous ink is 0.2 mass % or more and 4.5 mass % or less, the preservability and the ejection stability are more excellent than those in other Examples.
In Examples 1 to 5 in which the blending amount of the lignosulfonic acid salt or the like with respect to the aqueous ink is 0.5 mass % or more and 4.5 mass % or less when the coloring agent is a pigment, the preservability is excellent, and the OD value and the ejection stability more excellent than those in other Examples.
In addition, in Examples 1 to 4 in which the blending amount of the lignosulfonic acid salt or the like with respect to the aqueous ink is 1.2 mass % or more and 4.0 mass % or less when the coloring agent is a pigment, the preservability, the OD value, the ejection stability, and the storage stability are all excellent.
Further, in Examples 1 to 4 in which, when the coloring agent is a pigment, the mass ratio (A/C) of the content (A) of the pigment to the content (C) of the lignosulfonic acid salt or the like in the total amount of the aqueous ink is 1 or more and 9.5 or less, the preservability, the OD value, the ejection stability, and the storage stability are all more excellent.
In Examples 10 to 13 in which the blending amount of the lignosulfonic acid salt or the like with respect to the aqueous ink is 1.0 mass % or more and 5.0 mass % or less when the coloring agent is a dye, the preservability is more excellent than that in other Examples.
In addition, in Examples 10 to 12 in which, when the coloring agent is a water-soluble dye, the mass ratio (B/C) of the content (B) of the water-soluble dye to the content (C) of the lignosulfonic acid salt or the like in the total amount of the aqueous ink is 1 or more and 10 or less, the preservability, the ejection stability, and the printing quality are all more excellent than those in other Examples.
On the other hand, in Comparative Examples 1 to 3 not using the lignosulfonic acid salt, the preservability evaluation is all “C”, which is poor.
A part or all of the above embodiment and Examples may be described as the following appendixes, but the present invention is not limited thereto.
An aqueous ink for ink jet recording containing:
The aqueous ink for ink jet recording according to Appendix 1, in which a blending amount of the lignosulfonic acid or a salt thereof is 0.2 mass % or more and 4.5 mass % or less with respect to a total amount of the aqueous ink for ink jet recording.
The aqueous ink for ink jet recording according to Appendix 1 or 2, in which the coloring agent contains the self-dispersed pigment or the resin dispersion pigment.
The aqueous ink for ink jet recording according to Appendix 3, in which the blending amount of the lignosulfonic acid or a salt thereof is 0.5 mass % or more and 4.5 mass % or less with respect to the total amount of the aqueous ink for ink jet recording.
The aqueous ink for ink jet recording according to Appendix 3 or 4, in which a mass ratio (A/C) of a content (A) of the self-dispersion type pigment or the resin dispersion pigment to a content (C) of the lignosulfonic acid or a salt thereof is 1 or more and 9.5 or less in the total amount of the aqueous ink for ink jet recording.
The aqueous ink for ink jet recording according to Appendix 3, in which the blending amount of the lignosulfonic acid or a salt thereof is 1.2 mass % or more and 4.0 mass % or less with respect to the total amount of the aqueous ink for ink jet recording.
The aqueous ink for ink jet recording according to Appendix 1 or 2, in which the coloring agent contains the water-soluble dye.
The aqueous ink for ink jet recording according to Appendix 7, in which a blending amount of the dye is 1.0 mass % or more and 5.0 mass % or less with respect to the total amount of the aqueous ink for ink jet recording.
The aqueous ink for ink jet recording according to Appendix 7 or 8, in which a mass ratio (B/C) of a content (B) of the water-soluble dye to a content (C) of the lignosulfonic acid or a salt thereof is 1 or more and 10 or less in the total amount of the aqueous ink for ink jet recording.
An ink jet recording method including:
An ink jet recording device including:
An ink storage container containing an aqueous ink for ink jet recording, in which the aqueous ink for ink jet recording is the aqueous ink for ink jet recording according to any one of Appendixes 1 to 9.
As described above, the aqueous ink according to the present disclosure contains lignosulfonic acid or a salt thereof and thereby has preservability. The aqueous ink according to the present disclosure is widely applicable to ink jet recording on various recording media.
Obviously, numerous modifications and variations of the present invention(s) are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention(s) may be practiced otherwise than as specifically described herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-064540 | Apr 2022 | JP | national |
The present application is a continuation application of International Patent Application No. PCT/JP2023/013543 filed Mar. 31, 2023, which claims priority to Japanese Patent Application No. 2022-064540 filed Apr. 8, 2022. The contents of these applications are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/013543 | Mar 2023 | WO |
| Child | 18907739 | US |
