JP7102684B2 - Ink set, recording method and fixing agent - Google Patents

Description

The present invention relates to ink sets, recording methods and fixing agents.

An inkjet recording method has been proposed in which printing is performed on plain paper such as copy paper and report paper using a water-based ink containing a dye (hereinafter, may be referred to as "water-based dye ink") (Patent Documents). 1).

Japanese Unexamined Patent Publication No. 2003-127351

However, there is a demand for a new inkjet recording method capable of recording on a recording medium such as a cloth in addition to a recording paper such as plain paper. At this time, if the water-based dye ink for the recording paper is only diverted to the recording on the cloth, the color of the cloth will be discolored when the cloth is washed with water. It is also required that the color change (color difference) between the time of recording on the recording paper and the time of recording on the cloth is small.

Therefore, an object of the present invention is to provide an ink set containing an inkjet recording water-based ink and a fixing agent that can be used for recording both a recording paper and a recording medium other than the recording paper.

In order to achieve the above object, the ink set of the present invention is used.
An ink set containing a water-based ink for inkjet recording and a fixing agent.
The water-based ink for inkjet recording contains at least one of a direct dye and an acid dye, and water.
The fixing agent is characterized by containing cationic inorganic fine particles.

The ink set of the present invention contains both a recording paper and a recording medium other than the recording paper by containing an aqueous dye ink containing at least one of a direct dye and an acid dye and a fixing agent containing cationic inorganic fine particles. It is available for recording.

FIG. 1 is a schematic perspective view showing the configuration of an example of the inkjet recording apparatus of the present invention. 2A and 2B are diagrams showing a recording example by the recording method of the present invention.

[Ink set]
The ink set of the present invention will be described. The ink set of the present invention includes a water-based ink for inkjet recording (hereinafter, may be referred to as "water-based ink" or "ink") and a fixing agent.

(Water-based ink)
First, the water-based ink will be described. The water-based ink contains at least one of a direct dye and an acid dye, and water.

The direct dye is not particularly limited, and for example, C.I. I. Direct Black, C.I. I. Direct Blue, C.I. I. Direct Red, C.I. I. Direct Yellow, C.I. I. Direct orange, C.I. I. Direct Violet, C.I. I. Direct Brown, C.I. I. Direct green etc. can be mentioned. The C.I. I. As direct black, for example, C.I. I. Examples include Direct Black 17, 19, 32, 51, 71, 108, 146, 154 and 168. The C.I. I. As direct blue, for example, C.I. I. Direct blue 6, 22, 25, 71, 86, 90, 106 and 199 and the like can be mentioned. The C.I. I. As direct red, for example, C.I. I. Direct Red 1, 4, 17, 28, 83 and 227 and the like. The C.I. I. As direct yellow, for example, C.I. I. Direct yellow 12, 24, 26, 86, 98, 132, 142 and 173 and the like can be mentioned. The C.I. I. As direct orange, for example, C.I. I. Examples include Direct Orange 34, 39, 44, 46 and 60. The C.I. I. As direct violet, for example, C.I. I. Direct violet 47 and 48 and the like can be mentioned. The C.I. I. As direct brown, for example, C.I. I. Direct brown 109 and the like can be mentioned. The C.I. I. As a direct green, for example, C.I. I. Direct green 59 and the like can be mentioned.

The acid dye is also not particularly limited, and for example, C.I. I. Acid Black, C.I. I. Acid Blue, C.I. I. Acid Red, C.I. I. Acid Yellow, C.I. I. Acid Orange, C.I. I. Acid violet and the like can be mentioned. The C.I. I. As acid black, for example, C.I. I. Acid Black 2, 7, 24, 26, 31, 52, 63, 112 and 118 and the like can be mentioned. The C.I. I. As acid blue, for example, C.I. I. Acid blue 9, 22, 40, 59, 90, 93, 102, 104, 117, 120, 167, 229 and 234 and the like can be mentioned. The C.I. I. Acid red includes, for example, C.I. I. Acid Red 1, 6, 32, 37, 51, 52, 80, 85, 87, 92, 94, 115, 180, 256, 289, 315 and 317 and the like can be mentioned. The C.I. I. As acid yellow, for example, C.I. I. Acid Yellow 11, 17, 23, 25, 29, 42, 61, 71 and the like can be mentioned. The C.I. I. As acid orange, for example, C.I. I. Acid oranges 7 and 19 and the like can be mentioned. The C.I. I. As acid violet, for example, C.I. I. Acid Violet 49 and the like can be mentioned.

The blending amount of at least one of the direct dye and the acid dye in the total amount of the water-based ink is not particularly limited, and is, for example, 0.1% by weight to 20% by weight, 1% by weight to 15% by weight, and 2% by weight to 10% by weight. By weight%. At least one of the direct dye and the acid dye may be used alone or in combination of two or more.

The water is preferably ion-exchanged water or pure water. The blending amount of the water in the total amount of the water-based ink may be, for example, the balance of other components.

The water-based ink may further contain a water-soluble organic solvent. Examples of the water-soluble organic solvent include a wetting agent that prevents the ink from drying at the tip of the nozzle of the inkjet head and a penetrant that adjusts the drying rate on the recording medium.

The wetting agent is not particularly limited, and is, for example, a lower alcohol such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol; dimethylformamide, dimethylacetamide. Amids such as; ketones such as acetone; keto alcohols such as diacetone alcohols; ethers such as tetrahydrofuran and dioxane; polyethers such as polyalkylene glycols; polyhydric alcohols such as alkylene glycols, glycerin, trimethylolpropane, trimethylolethane; 2-pyrrolidone; N-methyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone; and the like. Examples of the polyalkylene glycol include polyethylene glycol and polypropylene glycol. Examples of the alkylene glycol include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, thiodiglycol, and hexylene glycol. These wetting agents may be used alone or in combination of two or more. Among these, polyhydric alcohols such as alkylene glycol and glycerin are preferable.

The blending amount of the wetting agent in the total amount of the water-based ink is, for example, 0% by weight to 95% by weight, 5% by weight to 80% by weight, and 5% by weight to 50% by weight.

Examples of the penetrant include glycol ether. Examples of the glycol ether include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol-n-propyl ether, diethylene glycol-n-butyl ether, and 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 Examples thereof include glycol-n-propyl ether and tripropylene glycol-n-butyl ether. The penetrant may be used alone or in combination of two or more.

The blending amount of the penetrant in the total amount of the water-based ink is, for example, 0% by weight to 20% by weight, 0% by weight to 15% by weight, and 1% by weight to 6% by weight.

If necessary, the water-based ink may further contain a conventionally known additive. Examples of the additive include a surfactant, a pH adjuster, a viscosity adjuster, a surface tension adjuster, a fungicide and the like. Examples of the viscosity adjusting agent include polyvinyl alcohol and cellulose.

In the water-based ink, for example, at least one of the direct dye and the acid dye, the water, and if necessary, other additive components are uniformly mixed by a conventionally known method, and an insoluble matter is mixed with a filter or the like. Can be prepared by removing.

(Fixing agent)
Next, the fixing agent will be described. The fixing agent contains cationic inorganic fine particles. The fixing agent is characterized by containing cationic inorganic fine particles, and other configurations are not limited in any way.

The cationic inorganic fine particles are not particularly limited, and examples thereof include cationic silica, cationic alumina, cationic zirconia, and cationic ceria, and among these, cationic silica is preferable. The cationic silica may be coated with alumina.

The average particle size of the cationic inorganic fine particles is, for example, 5 nm to 80 nm, 10 nm to 50 nm, and 10 nm to 30 nm. The average particle size can be determined by, for example, the BET method. When the average particle size of the cationic inorganic fine particles is 10 nm to 30 nm, it is possible to obtain an ink set in which discoloration after washing with water during recording on polyester is further suppressed.

The cationic inorganic fine particles may be so-called pearl necklace-shaped (bead-shaped) cationic inorganic fine particles having a shape in which a plurality of particles are connected. The average particle size of the pearl necklace-shaped cationic inorganic fine particles is, for example, 80 nm to 200 nm and 110 nm to 170 nm. The average particle size of the pearl necklace-shaped cationic inorganic fine particles can be determined by, for example, a dynamic light scattering method. The average particle size per single particle of the pearl necklace-shaped cationic inorganic fine particles is not particularly limited, but is, for example, 10 nm to 30 nm.

The cationic inorganic fine particles may be prepared in-house or a commercially available product may be used. Examples of the commercially available products include "ST-AK" (alumina-coated cationic silica, average particle diameter of 10 nm to 15 nm (BET method)) and "ST-AK-N" (alumina-coated) manufactured by Nissan Chemical Industry Co., Ltd. Cationic silica, average particle diameter 10 nm to 15 nm (BET method)), "ST-AK-PS-S" (pearl necklace-shaped alumina-coated cationic silica, average particle diameter 110 nm to 170 nm (dynamic light scattering method), simple Average particle diameter per particle 10 nm to 30 nm), "AS-520" (cationic alumina, average particle diameter 15 nm to 30 nm (BET method)), "ST-AK-L" (alumina-coated cationic silica, average particle diameter) 40 nm to 50 nm (BET method)), "ST-AK-YL" (alumina-coated cationic silica, average particle diameter 50 nm to 80 nm (BET method)), "ST-AK-XS" (alumina-coated cationic silica, average Particle diameter 4 nm to 6 nm (BET method)), "ST-AK-A" (alumina-coated cationic silica, average particle diameter 10 nm to 15 nm (BET method)), "AS-100" (cationic alumina, average particle diameter) 6 nm to 10 nm (BET method)), "AS-200" (cationic alumina, average particle diameter 7 nm to 15 nm (BET method)), "AS-550" (cationic alumina, average particle diameter 25 nm to 40 nm (BET method)) )), "ZR-30AL" (cationic zirconia, average particle diameter 5 nm to 10 nm (BET method)), "CE-20A" (cationic ceria, average particle diameter 8 nm to 12 nm (BET method)) and the like. ..

The blending amount of the cationic inorganic fine particles in the total amount of the fixing agent is, for example, 3% by weight to 20% by weight, 5% by weight to 20% by weight, 7% by weight to 15% by weight, and 7% by weight to 10% by weight. .. When the blending amount of the cationic inorganic fine particles is 7% by weight or more, it is possible to obtain an ink set in which discoloration after washing with water during recording on polyester is further suppressed.

The fixing agent may further contain water. The water is preferably ion-exchanged water or pure water. The blending amount of the water in the total amount of the fixing agent may be, for example, the balance of other components.

The fixing agent may further contain a water-soluble organic solvent. As the water-soluble organic solvent, for example, the same solvent as those exemplified in the water-based ink can be used. The blending amount of the water-soluble organic solvent in the total amount of the fixing agent is, for example, 0% by weight to 95% by weight, 5% by weight to 80% by weight, 5% by weight to 50% by weight.

The fixing agent may further contain a conventionally known additive, if necessary. As the additive, for example, the same additive as those exemplified in the water-based ink can be used.

The fixing agent can be prepared, for example, by uniformly mixing the cationic inorganic fine particles and, if necessary, other additive components by a conventionally known method.

In the ink set of the present invention, the fixing agent may be, for example, a pretreatment agent applied to the recording medium before the water-based ink is ejected to the recording medium.

[Recording method]
Next, the recording method of the present invention will be described.

The recording method of the present invention
A recording method for recording using the ink set of the present invention.
Whether or not to apply the fixing agent is selected according to the type of the recording medium, and when it is selected to be applied, a fixing agent applying step of applying the fixing agent to the recording medium and a fixing agent applying step.
A recording step of ejecting the water-based ink onto the recording medium by an inkjet method and recording the ink is included.
In the fixing agent applying step, when the recording medium is a recording medium other than the recording paper, it is characterized by selecting to apply the fixing agent. The recording includes printing, printing, printing and the like.

In the recording method of the present invention, examples of the recording medium other than the recording paper include cloth and the like. The fabric includes both knitted fabrics and woven fabrics. The material of the cloth may be a natural fiber or a synthetic fiber. Examples of the natural fiber include cotton and silk. Examples of the synthetic fiber include polyester, nylon, acrylic and the like.

The ink set in the recording method of the present invention is the same as the ink set of the present invention described above, and the description thereof can be incorporated.

The recording method of the present invention can be carried out using, for example, the inkjet recording apparatus of the present invention described below.

The inkjet recording device of the present invention is an inkjet recording device including an ink set accommodating portion, a fixing agent applying means, and an ink ejection means. The ink set is accommodated in the ink set accommodating portion, and the ink is contained. The fixing agent constituting the set can be applied to the recording medium by the fixing agent applying means, and the water-based ink constituting the ink set is ejected to the recording medium by the ink ejection means. do.

FIG. 1 shows a configuration of an example of the inkjet recording apparatus of the present invention. As shown in the figure, the inkjet recording device 1 includes four ink cartridges 2, an ink ejection means (inkjet head) 3, a head unit 4, a carriage 5, a drive unit 6, a platen roller 7, and a purge device 8. And are included as the main components.

The four ink cartridges 2 contain one color each of four water-based inks of yellow, magenta, cyan, and black. For example, at least one of the four color water-based inks is the water-based ink that constitutes the ink set. In this example, a set of four ink cartridges 2 is shown, but instead, the water-based yellow ink storage part, the water-based magenta ink storage part, the water-based cyan ink storage part, and the water-based black ink storage part are formed. An integrated ink cartridge with a partitioned interior may be used. As the main body of the ink cartridge, for example, a conventionally known one can be used.

The inkjet head 3 installed in the head unit 4 records on a recording medium (for example, recording paper P). The recording medium may be a recording medium other than the recording paper P such as cloth. Four ink cartridges 2 and a head unit 4 are mounted on the carriage 5. The drive unit 6 reciprocates the carriage 5 in the linear direction. As the drive unit 6, for example, a conventionally known one can be used (see, for example, Japanese Patent Application Laid-Open No. 2008-246821). The platen roller 7 extends in the reciprocating direction of the carriage 5 and is arranged so as to face the inkjet head 3.

The purging device 8 sucks defective ink containing air bubbles and the like accumulated inside the inkjet head 3. As the purging device 8, for example, a conventionally known device can be used (see, for example, Japanese Patent Application Laid-Open No. 2008-246821).

A wiper member 20 is arranged adjacent to the purge device 8 on the platen roller 7 side of the purge device 8. The wiper member 20 is formed in a spatula shape, and wipes the nozzle forming surface of the inkjet head 3 as the carriage 5 moves. In FIG. 1, the cap 18 covers a plurality of nozzles of the inkjet head 3 which are returned to the reset position when the recording is completed in order to prevent the water-based ink from drying.

In the inkjet recording apparatus 1 of 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 to this. In the inkjet recording apparatus 1, each cartridge of the four ink cartridges 2 may be mounted on a carriage different from that of the head unit 4. Further, each of the four ink cartridges 2 may not be mounted on the carriage 5 but may be arranged and fixed in the inkjet recording device 1. In these aspects, for example, each cartridge 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 each cartridge of the four ink cartridges 2 is connected to the head unit 4. Water-based ink is supplied. Further, in these aspects, four bottle-shaped ink bottles 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 ink from the outside to the inside.

Recording using the inkjet recording device 1 is performed, for example, as follows. First, whether or not to apply the fixing agent constituting the ink set is selected according to the type of the recording medium, and when it is selected to be applied, the fixing agent is applied to the recording medium. Specifically, when the recording medium is a recording medium other than the recording paper P (for example, a cloth or the like), the fixing agent is applied to the recording medium. In the present invention, the fixing agent can be applied by, for example, a spray method, stamp coating, brush coating, roller coating, an inkjet method, or the like. The fixing agent may be applied to the entire surface or a part of the recording surface of the recording medium. When it is applied to a part, at least the recording portion of the recording surface of the recording medium with water-based ink becomes the imparting portion. When it is given to a part, the size of the giving portion should be larger than that of the recording portion. For example, as shown in FIG. 2A, when the character (X) is recorded on the recording medium F, the fixing agent is formed so as to form the imparting portion 30 with a line width larger than the line width of the character. Is preferably given. Further, as shown in FIG. 2B, when recording a symbol on the recording medium F, it is preferable to impart the fixing agent so as to form an imparting portion 40 larger than the symbol. The recording method of the present invention may include, for example, a drying step of heat-treating the recording medium at 210 ° C. or lower to dry it after the fixing agent application step when the recording medium is a recording medium other than the recording paper P. good. The lower limit of the heat treatment temperature in the drying step is not particularly limited, and is, for example, 80 ° C. or higher. When the recording medium is the recording paper P, the following steps are carried out without performing these steps.

Next, the water-based ink is ejected from the inkjet head 3 to the recording medium. At this time, when the recording medium is a recording medium other than the recording paper P, the water-based ink is ejected to the fixing agent applying portion.

In this example, when the recording medium is a recording medium other than the recording paper P, the fixing agent is used as a pretreatment agent to be applied to the recording medium prior to ejection of the water-based ink. However, the present invention is not limited to this. In the present invention, the fixing agent may be applied after the water-based ink is first ejected to the recording medium, or the fixing agent is applied to the recording medium and the water-based ink is ejected at the same time. May be good.

The recording medium recorded in this way is discharged from the inkjet recording device 1. According to the present invention, even when recording is performed on a cloth instead of the recording paper P, discoloration after washing with water is suppressed. Since at least one of the direct dye and the acid dye contained in the water-based ink is generally anionic, the effect of suppressing discoloration can be obtained by using the cationic inorganic fine particles contained in the fixing agent to obtain the direct dye and the acid. It is presumed that the charge of at least one of the dyes was canceled to make it non-aqueous, and the water resistance was improved. However, this mechanism is only an estimation, and the present invention is not limited thereto. Further, according to the present invention, the color change (color difference) between the time of recording on the recording paper P and the time of recording on the cloth is small. Note that in FIG. 1, the paper feeding mechanism and the paper discharging mechanism of the recording paper P are not shown.

The apparatus shown in FIG. 1 employs a serial type inkjet head, but the present invention is not limited thereto. The inkjet recording device may be a device that employs a line-type inkjet head.

[recoding media]
Next, the recording medium of the present invention will be described.

The recording medium of the present invention is
A recording medium in which a coating layer is formed on a base material.
The coating layer is characterized by containing cationic inorganic fine particles.

In the recording medium of the present invention, examples of the base material include cloth, recording paper, and the like. The formation of the coating layer on the substrate can be carried out in the same manner as, for example, the method of applying the fixing agent to the recording medium in the recording method of the present invention described above.

[Fixing agent]
Next, the fixing agent of the present invention will be described.

The fixing agent of the present invention
It is a fixing agent for fixing at least one of a direct dye and an acid dye contained in an inkjet recording water-based ink to a recording medium, and is characterized by containing cationic inorganic fine particles and water.

In addition to the cationic inorganic fine particles and water, the fixing agent may contain any component similar to the fixing agent in the ink set of the present invention described above. The preparation of the fixing agent can be carried out, for example, in the same manner as the preparation of the fixing agent in the ink set of the present invention described above.

Next, examples of the present invention will be described together with comparative examples. The present invention is not limited or limited by the following examples and comparative examples.

[Preparation of water-based ink]
Each component of the ink composition (Table 1) was uniformly mixed. Then, the obtained mixture is filtered using a polytetrafluoroethylene (PTFE) type membrane filter (pore size 0.20 μm) manufactured by Toyo Filter Paper Co., Ltd. to obtain water-based yellow ink Y for inkjet recording and inkjet recording. Aqueous cyan inks C1 to C3 and an aqueous magenta ink M for inkjet recording were obtained.

[Preparation of fixing agent]
Each component of the fixing agent composition (Table 2) was uniformly mixed to obtain 12 kinds of fixing agents.

[Examples 1 to 8 and Comparative Examples 1 to 5]
By combining the water-based yellow ink Y, the water-based cyan inks C1 to C3 or the water-based magenta ink M shown in Table 1, and the 12 types of fixing agents shown in Table 2, the inks of Examples 1 to 8 and Comparative Examples 1 to 5 are used. Got a set.

For the ink sets of Examples 1 to 8 and Comparative Examples 1 to 5, (a) image quality evaluation (color difference between recording paper and cotton), (b) fixability evaluation (color difference before and after washing with cotton), (c) Image quality evaluation (color difference between recording paper and polyester), (d) fixability evaluation (color difference before and after washing with polyester), and (e) comprehensive evaluation were carried out by the following methods.

(A) Image quality evaluation (color difference between recording paper and cotton)
(Color measurement of evaluation sample of recording paper)
Using the DCP-J4225N digital multifunction device equipped with an inkjet printer manufactured by Brother Industries, Ltd., and using the water-based inks that make up the ink sets of Examples and Comparative Examples, recording paper (“Super White” manufactured by ASKUL Corporation). A monochromatic patch of yellow, cyan, and magenta was recorded on + ") to prepare an evaluation sample. The colors (L ^* ₁ , a ^* ₁ and b ^* ₁ ) of each color patch of the evaluation sample of the recording paper are measured by the spectrocolorimeter Spectorolino manufactured by Gretag Macbeth (measurement field: 2 °; white reference: Abs (absolute white)). ); Light source: D50; Concentration standard: ANSI T). The measurement result of the color (L ^* ₁ , a ^* ₁ and b ^* ₁ ) is an average value of three measurements.

(Color measurement of cotton evaluation sample)
1 g of a fixing agent constituting the ink sets of Examples and Comparative Examples was uniformly applied onto cotton (sheeting) having a plane size of 15 cm × 5 cm by a spray method. The cotton after the fixing agent was applied was dried by ironing at a high temperature (180 ° C. to 210 ° C.) up to 210 ° C. for 2 minutes. Next, using the DCP-J4225N digital multifunction device equipped with an inkjet printer, a single color patch of yellow, cyan, and magenta was recorded on the cotton in the same manner as on the recording paper, and an evaluation sample was prepared. The colors (L ^* ₂ , a ^* ₂ , and b ^* ₂ ) of each color patch of the cotton evaluation sample were measured in the same manner as the evaluation sample of the recording paper.

(Calculation of color difference (ΔE ₁ ))
The color difference (ΔE ₁ ) between the color of the evaluation sample of the recording paper and the color of the evaluation sample of cotton was calculated by the following formula and evaluated according to the following evaluation criteria.

ΔE ₁ = {(L ^* ₁ -L ^* ₂ ) ² + (a ^* ₁ -a ^* ₂ ) ² + (b ^* ₁ -b ^* ₂ ) ² } ^1/2

Image quality evaluation (color difference between recording paper and cotton) Evaluation Criteria A: Color difference between recording paper and cotton (ΔE ₁ ) is 5.0 or less B: Color difference between recording paper and cotton (ΔE ₁ ) is 5.0 More than 15.0 and less than 15.0 C: The color difference (ΔE ₁ ) between the recording paper and cotton is 15.0 or more.

(B) Fixability evaluation (color difference before and after washing with cotton)
(A) The cotton evaluation sample in the image quality evaluation (color difference between the recording paper and cotton) was washed with water for 5 minutes while shaking so that a part of the evaluation sample did not rub against other parts in water. The colors (L ^* ₃ , a ^* ₃ , and b ^* ₃ ) of each color patch of the evaluation sample obtained by washing with water and then drying are used as the recording paper in (a) image quality evaluation (color difference between recording paper and cotton). The color difference (ΔE ₂ ) of the cotton evaluation sample before and after washing with water was calculated by the following formula and evaluated according to the following evaluation criteria.

ΔE ₂ = {(L ^* ₂ -L ^* ₃ ) ² + (a ^* ₂ -a ^* ₃ ) ² + (b ^* ₂ -b ^* ₃ ) ² } ^1/2

Fixability evaluation (color difference before and after washing with cotton) Evaluation criteria A: Color difference before and after washing with water (ΔE ₂ ) is 5.0 or less B: Color difference before and after washing with water (ΔE ₂ ) is 5. More than 0 and less than 15.0 C: Color difference (ΔE ₂ ) before and after washing is 15.0 or more

(C) Image quality evaluation (color difference between recording paper and polyester)
(A) Image quality evaluation (recording) except that polyester felt of the same flat size was used instead of cotton (sheeting) and the temperature of the iron was set to a medium temperature (140 ° C to 160 ° C). The color difference (ΔE ₃ ) between the color of the evaluation sample of the recording paper and the color of the evaluation sample of the polyester (L ^* ₄ , a ^* ₄ , and b ^* ₄ ) is determined in the same manner as the color difference between the paper and cotton. , Calculated by the following formula and evaluated according to the following evaluation criteria.

ΔE ₃ = {(L ^* ₁ -L ^* ₄ ) ² + (a ^* ₁ -a ^* ₄ ) ² + (b ^* ₁ -b ^* ₄ ) ² } ^1/2

Image quality evaluation (color difference between recording paper and polyester) Evaluation criteria A: Color difference between recording paper and polyester (ΔE ₃ ) is 5.0 or less B: Color difference between recording paper and polyester (ΔE ₃ ) is 5.0 More than 15.0 and less than 15.0 C: The color difference (ΔE ₃ ) between the recording paper and polyester is 15.0 or more.

(D) Fixability evaluation (color difference before and after washing with polyester)
The polyester evaluation sample in (c) image quality evaluation (color difference between recording paper and polyester) was washed with water and dried in the same manner as the cotton evaluation sample in (b) fixability evaluation (color difference before and after washing with cotton). The colors (L ^* ₅ , a ^* ₅ , and b ^* ₅ ) of each color patch of the obtained evaluation sample are set to be the same as the evaluation sample of the recording paper in (a) image quality evaluation (color difference between recording paper and cotton). The color difference (ΔE ₄ ) of the polyester evaluation sample before and after washing with water was calculated by the following formula and evaluated according to the following evaluation criteria.

ΔE ₄ = {(L ^* ₄ -L ^* ₅ ) ² + (a ^* ₄ -a ^* ₅ ) ² + (b ^* ₄ -b ^* ₅ ) ² } ^1/2

Fixability evaluation (color difference before and after washing with polyester) Evaluation criteria A: Color difference before and after washing with water (ΔE ₄ ) is 5.0 or less B: Color difference before and after washing with water (ΔE ₄ ) is 5. More than 0 and less than 15.0 C: Color difference (ΔE ₄ ) before and after washing is 15.0 or more

(E) Comprehensive evaluation Based on the results of (a) to (d) above, comprehensive evaluation was performed for Examples and Comparative Examples according to the following evaluation criteria.

Comprehensive evaluation Evaluation criteria A: There was no C in the results of (a) to (d).
B: Only the result of (d) was C.
C: Among the results of (a) to (d), there was C in two or more.

Table 2 shows the fixing agent compositions and evaluation results of Examples 1 to 8 and Comparative Examples 1 to 5. In addition, "Y" in the evaluation column of Table 2 indicates the evaluation with the ink set combined with the water-based yellow ink Y shown in Table 1, and "C1", "C2" and "C3" are shown in Table 1. The evaluation with the ink set combined with the water-based cyan ink C1, C2 or C3 is shown, and "M" indicates the evaluation with the ink set combined with the water-based magenta ink M shown in Table 1.

As shown in Table 2, in Examples 1 to 8, the evaluation results with cotton were good, and in particular, Examples 1 and 2 using cationic inorganic fine particles having an average particle diameter of 10 nm to 30 nm as the fixing agent. In No. and 6, the results of color difference evaluation before and after washing with water were superior to those of Example 8 in which the same amount of cationic inorganic fine particles having an average particle diameter of 40 nm to 50 nm was used. Further, in particular, in Examples 3 and 4 in which the blending amount of the cationic inorganic fine particles was 7% by weight or more in the fixing agent, the same type of cationic inorganic fine particles were used and the blending amount was 5% by weight. The result of the color difference evaluation before and after washing with water with polyester was superior to that. On the other hand, in Comparative Examples 1 to 4 in which the anionic inorganic fine particles were used instead of the cationic inorganic fine particles in the fixing agent, and in the water-based ink, a basic dye was used instead of at least one of the direct dye and the acid dye. In Comparative Example 5, both the evaluation results of the fixability with cotton and polyester were poor.

As described above, the ink set of the present invention can be used for recording both the recording paper and the recording medium other than the recording paper. The application of the ink set of the present invention is not particularly limited, and it can be widely applied to various inkjet recordings.

1 Inkjet recording device 2 Ink cartridge 3 Ink ejection means (inkjet head)
4 Head unit 5 Carriage 6 Drive unit 7 Platen roller 8 Purge device

Claims (16)

An ink set containing a water-based ink for inkjet recording and a fixing agent.
The water-based ink for inkjet recording contains at least one of a direct dye and an acid dye, and water.
The fixing agent contains cationic inorganic fine particles and contains
The ratio (C / D) of the blending amount (C) of the cationic inorganic fine particles to the blending amount (C / D) of at least one of the direct dye and the acidic dye in the water-based ink for inkjet recording is 1.25 to 2 . For recording including a drying step of drying the recording medium by heat treatment at least after the fixing agent is applied to a recording medium other than the recording paper and before the water-based ink for inkjet recording is applied. An ink set characterized by being used . The ink set according to claim 1, wherein the cationic inorganic fine particles are cationic silica. The ink set according to claim 1 or 2, wherein the average particle size of the cationic inorganic fine particles is 10 nm to 30 nm. The ink set according to claim 1 or 2, wherein the cationic inorganic fine particles have a shape in which a plurality of particles are connected. The ink set according to claim 4, wherein the average particle diameter per single particle of the cationic inorganic fine particles having a shape in which a plurality of particles are connected is 10 nm to 30 nm. The ink set according to any one of claims 1 to 5, wherein the blending amount of the cationic inorganic fine particles in the total amount of the fixing agent is 7% by weight or more. The ink set according to any one of claims 1 to 6, wherein the fixing agent is a pretreatment agent applied to the recording medium before the water-based ink for inkjet recording is ejected to the recording medium. A recording method for recording using the ink set according to any one of claims 1 to 7.
Whether or not to apply the fixing agent is selected according to the type of the recording medium, and when it is selected to be applied, the fixing agent applying step of applying the fixing agent to the recording medium and the fixing agent applying step.
A recording step of ejecting the water-based ink onto the recording medium by an inkjet method and recording the ink.
When the recording medium is a recording medium other than the recording paper, the recording medium includes a drying step of drying the recording medium after the fixing agent application step .
A recording method characterized in that, in the fixing agent application step, when the recording medium is a recording medium other than recording paper, the fixing agent is selected to be applied. The recording method according to claim 8, wherein the recording medium other than the recording paper is a cloth. The recording method according to claim 8 or 9 , wherein the drying in the drying step is performed by at least heat-treating the recording medium at 210 ° C. or lower . A fixing agent for fixing at least one of a direct dye and an acid dye contained in an aqueous ink for inkjet recording to a recording medium.
Containing cationic inorganic fine particles and water,
The blending amount (C) of the cationic inorganic fine particles is a ratio (C) of 1.25 to 2.5 with respect to the blending amount (D) of at least one of the direct dye and the acid dye in the water-based ink for inkjet recording. / D), a recording including a drying step of drying the recording medium by heat treatment after the fixing agent is applied to at least a recording medium other than the recording paper and before the water-based ink for inkjet recording is applied. A fixing agent characterized by being used in . The fixing agent according to claim 11, wherein the cationic inorganic fine particles are cationic silica. The fixing agent according to claim 11 or 12, wherein the average particle size of the cationic inorganic fine particles is 10 nm to 30 nm. The fixing agent according to claim 11 or 12, wherein the cationic inorganic fine particles have a shape in which a plurality of particles are connected. The fixing agent according to claim 14, wherein the average particle diameter per single particle of the cationic inorganic fine particles having a shape in which a plurality of particles are connected is 10 nm to 30 nm. The fixing agent according to any one of claims 11 to 15, wherein the blending amount of the cationic inorganic fine particles in the total amount of the fixing agent is 7% by weight or more.

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