JP2002363463A - Ink composition for inkjet printing and inkjet printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink composition satisfying various performances required for ink compositions for inkjet printing in higher degrees and capable of realizing good printed image, and to provide an inkjet printing method using the ink composition. SOLUTION: This ink composition for inkjet printing comprises at least a reactive dye in which >=50% reactive groups are previously reacted and an organic solvent having >=150 deg.C boiling point at ordinary pressure and water, and has <=8.0 mPs viscosity (at 20 deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for ink-jet printing and an ink-jet printing method using the same.

2. Description of the Related Art Ink jet printing methods include:
This is a printing method in which small droplets of ink are made to fly and adhere to a recording medium such as paper or transparency. This method
It has the feature that high-resolution, high-quality images can be printed at high speed with a relatively inexpensive device.

[0003] If this ink jet printing method is applied to textile printing, various images having excellent gradation and multicolor expression can be easily formed on cloth. Further, there is almost no surplus ink generated in the conventional printing process, which is effective for environmental protection.

The important points in ink-jet printing are that the ink can realize a high-color printed image, that the ink can be adjusted to have a low viscosity suitable for ink-jet printing, and that the ink has a favorable matching property with the pretreatment agent of the fabric and has good matching properties. The image can be realized, the ink drying time is relatively short, for example, no set-off occurs when the fabric is wound up after printing, and the ink can withstand long-term storage. It should be noted that the term “ink drying” as used in the present invention includes not only evaporation of ink components but also the fact that the ink penetrates the cloth and the transfer of the ink does not occur by touching with a finger or the like.

As ink jet printing methods using a reactive dye ink, for example, JP-A-5-186727, JP-A-5-239391, JP-A-6-145569,
JP-A-6-264018 and JP-A-7-173780 are mentioned.

As an ink jet printing method using an acid dye ink, for example, JP-A-5-255627,
JP-A-6-25576, JP-A-7-258982,
JP-A-9-296380 is mentioned.

[0007]

SUMMARY OF THE INVENTION The present inventors have now found an ink which has excellent applicability to an ink jet recording method and storage stability, and can realize a better image on a fabric, and an ink jet printing method using the ink. .

Accordingly, an object of the present invention is to provide an ink which is excellent in applicability to an ink jet recording method and storage stability, and can realize a better image on a cloth.

Another object of the present invention is to provide an ink jet printing method for realizing a good image on a cloth.

The ink for ink jet textile printing according to the present invention comprises: a reactive dye having a reactive group reacted at least 50% in advance; an organic solvent having a boiling point at normal pressure of 150 ° C. or higher;
Water and at least a viscosity of 8.0 mPs
(20 ° C.) or less. Further, it is an ink composition for ink-jet printing, to which additives such as a surfactant, a metal-sequestering agent, a corrosion inhibitor and the like are appropriately added in order to impart proper ink-jet ejection and storage stability.

Further, the ink jet printing method according to the present invention comprises discharging ink droplets of an ink composition and attaching the ink droplets to a cloth containing amide fibers such as silk, wool, nylon and the like. An ink jet printing method, wherein the ink composition according to the present invention is used as the ink composition, and the cloth is pre-coated with a pretreatment agent containing at least a sizing agent and a hydrotrope agent. Which is an inkjet printing method.

Further, the ink jet printing method of the present invention is a printing method in which an ink-repellent treatment is applied to the surface layer of the print head and the ejection stability is excellent.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Inkjet textile printing ink> The dye used in the present invention is a reactive dye having a reactive group reacted at least 50% in advance. The type of dye is not particularly limited as long as it is fixed to the fabric by heating and vapor deposition. For example, a dye having a monochlorotriazinyl group, a dichlorotriazinyl group, a chloropyrimidyl group, a vinylsulfone group, an alkyl sulfate group, or the like as a reactive group is preferable. These dyes are selected according to individual purposes. The dyes of the present invention improve storage stability, which is a disadvantage of reactive dyes. Further, the present invention provides a dye which achieves a proper printing quality by using fibers having an amide group such as silk, wool, nylon, etc. by increasing the selection of dyes.

Specific examples of such a dye include the following dyes, but are not limited thereto.
C. I. Reactive Yellow 2,3,7,15,1
7, 18, 22, 23, 24, 25, 27, 37, 3,
9, 42, 57, 76, 81, 84, 85, 95, 10,
2, 105, C.I. I. Reactive Orange 1, 5, 7, 11, 1
2, 13, 15, 16, 20, 30, 35, 64, 6
7, 69, 70, 72, 74, C.I. I. Reactive Red 3, 5, 21, 22, 2
3, 24, 33, 35, 43, 49, 55, 56, 5,
8, 65, 66, 78, 83, 106, 111, 11
2, 113, 114, 116, 120, 123, 12
4, 136, 141, 147, 158, 159, 17
1, C.I. I. Reactive Blue 2, 4, 5, 7, 13, 1
4, 15, 19, 21, 27, 28, 38, 41, 4
9, 50, 52, 69, 71, 72, 73, 77, 7
9, 89, 112, 114, 116, 120, 122,
137, 147, 176, 180, 182, 184, 1
95, 203, 204, 207, C.I. I. Reactive Green 12, 15, 19, 2
1, and C.I. I. Reactive Black 5, 8, 13, 14, 3
1,39 The reactive dye of the present invention refers to a substance classified as a reactive dye in the color index.

The ink of the present invention has excellent dye stability.
Normally, when a reactive dye is stored in an aqueous solution for a long period of time, hydrolysis proceeds, and the printing characteristics change from the initial stage. In addition, the dye solution becomes acidic and corrodes when filled in a machine having metal parts such as a printer for a long period of time, and it is difficult to secure stable discharge. The dye used in the ink of the present invention is a material in which the reactive group of the reactive dye has been treated in advance by 50% or more, and substantially eliminates the problem of the reactive dye.

In the ink of the present invention, the amount of the dye added may be appropriately determined, but is preferably about 0.1 to 15% by weight, more preferably about 0.3 to 10% by weight, based on the ink. Further, the gradation of the printed material can be further improved by using a light and dark ink in which the dye density is changed to the same color or a similar color. This dark and light ink is particularly effective in alleviating the graininess in the middle to low density region.

When printing the ink of the present invention on a blended fabric containing fibers that are difficult to dye with a reactive dye, if a different type of dye is added to the ink of the present invention and printing is performed, the blended fabric is further printed. Good printing is obtained. For example, by performing ink-jet printing on a cloth made of silk and polyester with an ink containing a disperse dye added to the ink of the present invention, a good print quality can be obtained on polyester. Further, the ink of the present invention and the disperse dye ink may be ejected from separate inkjet print nozzles. The ejection order may be appropriately determined according to the printing system.

Furthermore, for example, in the case of silk or wool coated with the pretreatment agent of the present invention, or a blend containing one of them, the color reproduction range can be expanded by adding an acid dye to the ink of the present invention. It is possible. Further, the ink of the present invention and the acid dye ink may be ejected from different nozzles. The ejection order may be appropriately determined according to the printing system.

According to a preferred embodiment of the present invention, the dye is preferably purified to a concentration of 1% by weight or less as a salt derived from the dye in the ink composition. By using such a purified dye, the ejection stability of the ink composition can be ensured at a high level, and the generation of rust on the metal part of the printer can be suppressed.

The ink composition according to the present invention preferably uses an organic solvent having a boiling point at normal pressure of 150 ° C. or higher as an organic solvent. By utilizing such an organic solvent,
An advantage is obtained in that drying of the ink composition can be effectively prevented, thereby preventing nozzle clogging. Examples of such organic solvents include ethylene glycol, diethylene glycol, propylene glycol,
Triethylene glycol, tetraethylene glycol,
Those having a hydroxyl group such as glycerin and thioglycol are preferred.

The amount of the organic solvent having a boiling point of 150 ° C. or higher may be appropriately determined.
It is preferably about 50% by weight, more preferably 10 to 40%.
% By weight. These solvents may be used alone or in combination.

It is needless to say that the organic solvent preferably has a substantial compatibility as a solvent with the components of the ink composition. Here, “substantially compatible” means that the obtained ink composition has a solubility that does not cause phase separation and does not cause precipitation. More preferably, it means a solubility that does not cause phase separation between components that are liquid at room temperature even during drying.

According to a preferred embodiment of the present invention, the addition of the alkylene glycol alkyl ether is preferable because it has a remarkable effect on preventing the ink composition from drying and stabilizing the ejection of the ink composition from the nozzle. These materials include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
Examples thereof include diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, and triethylene glycol monobutyl ether.

Further, according to a preferred embodiment of the present invention, it is desirable to add a pyrrolidone organic solvent. The pyrrolidone-based solvent improves the compatibility of the entire ink composition and improves the stability of inkjet discharge. These materials include N-methylpyrrolidone, 2-pyrrolidone, and the like.

Further, in the present invention, it is desirable to add a sequestering agent. The preferable addition amount is 0.001 to 0.1% by weight.
And more preferably 0.005 to 0.03% by weight. Addition of the blocking agent has the effect of stably ejecting the inkjet ink of the present invention for a long period of time. Further, a stable density and hue can be secured on the printing cloth. Ethylenediaminetetraacetic acid (EDTA) as a sequestering agent,
EDTA salts and hydroxyethylethylenediaminetriacetic acid (EDTA-OH) are preferred. The EDTA salt is preferably an alkali metal salt, and particularly preferably a sodium disalt.

Further, the ink of the present invention is obtained by adding a surfactant. Preferred surfactants are anionic or nonionic. The ink containing the surfactant is advantageous in that it uniformly wets even on the pretreated fabric, reduces imprints, and penetrates into the fabric in a short time.
In addition, the piezo-vibration type has the effect of improving bubble discharge in the print head, which causes ejection failure, and maintaining stable ejection. Nonionic surfactants are particularly effective in this bubble discharging property.

Preferred examples of the nonionic surfactant include an ethylene glycol surfactant, a polyhydric alcohol surfactant, and an acetylene glycol surfactant. According to a preferred embodiment of the present invention, the use of an acetylene glycol-based surfactant is preferred. Particularly preferred are acetylene glycol-based surfactants,
Activators of this type include, for example, Olfin Y, Surfynol 82, Surfynol 440, Surfynol 465,
Surfynol 485 (both manufactured by AirProd
octs and Chemicals. Inc. ).

The addition amount of the nonionic surfactant may be determined as appropriate, but is preferably about 0.05 to 5% by weight, more preferably about 0.1 to 3% by weight, based on the ink composition.

According to a preferred embodiment of the present invention, the nonionic surfactant has a boiling point of 15%.
Solubility in organic solvent of 0 ° C or higher is 10 g / 100 g
It is preferable to use the above. The use of the nonionic surfactant and the organic solvent satisfying such a relationship is advantageous in that the ejection stability from the nozzle in a high temperature environment (for example, 35 ° C.) can be ensured. This effect is particularly effective for a piezo type ink jet printing system using a piezoelectric element.

In the ink composition according to the present invention, water is the main solvent. As the water, pure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, or distilled water, or ultrapure water can be used. In addition, it is preferable to use water sterilized by ultraviolet irradiation, addition of hydrogen peroxide, or the like, since the generation of mold and bacteria can be prevented when the ink composition is stored for a long period of time.

The ink composition according to the present invention has a viscosity of 20.
8.0 mPas or less at 150C, preferably 1.5 to 6.0.
in the range of mPas. In this range, ink can be ejected without any trouble over a wide temperature range. An ink exceeding 8.0 mPas at 20 ° C. has poor ejection stability in a low temperature region.

According to an embodiment of the present invention, urea or alkyl urea is used as a hydrotrope in an amount of 2 to 1 in terms of solid content.
More preferably, 0% by weight and 1 to 5% by weight of thiourea are added in combination. Addition of these to the ink composition not only has an effect on long-term dry clogging, but also
It is effective for improving printing density. In addition, thiourea is particularly effective for improving leveling properties.

Preferred examples of the hydrotrope include alkyl ureas such as urea, dimethyl urea, thiourea, monomethyl thiourea and dimethyl thiourea. The printing density can be improved by adding a hydrotrope agent. Also, these hydrotropes can be added in combination with urea, alkyl urea and thiourea.

These hydrotropic agents are also effective as constituent materials of a pretreatment agent for fabric used in the ink jet ink for textile printing of the present invention. The pretreatment agent containing a hydrotrope is effective for improving the stability and stabilizing the surface state of the padding cloth. In addition, thiourea is particularly effective for improving leveling properties.

In the ink according to the present invention, in addition to the above components, additives may be added to improve various properties of the ink composition. Examples of such additives include:
Preservatives. Preferred examples of preservatives include Proxel CRL, Proxel BDN, Proxel GX
L, Proxel XL-2, Proxel IB, Proxel TN and the like.

The ink according to the present invention preferably contains a corrosion inhibitor in addition to the above components. A preferred example is benzotriazole. In particular, in a head whose surface is treated with ink repellent, benzotriazole maintains the ink repellent effect.

<Inkjet printing method> The fabric to which the ink composition according to the present invention is preferably applied is a fabric composed of fibers containing animal proteins such as silk and wool or polyamide fibers such as nylon.

In the present invention, the application of the ink composition to the cloth is carried out by an ink jet recording method. As the ink jet recording method, a so-called piezo-type ink jet recording method in which ink droplets are formed and discharged by mechanical volume change of a piezoelectric element, heat energy is applied to the ink composition, and the ink droplets are formed by utilizing the volume expansion caused thereby. Is formed, and the ink stored in the nozzle head portion to be ejected is heated rapidly at a portion very close to the ejection portion to generate bubbles, which are intermittently ejected by volume expansion due to the bubbles, and are discharged onto the surface of the recording medium. Any of the ink jet recording methods for recording characters and symbols may be used. In particular, printing requires that the ink be stably ejected for a long time in one printing. The present ink can satisfy such requirements.
In particular, matching with a piezo type print head is excellent.

In the ink jet printing method according to the present invention, the cloth is preferably subjected to the following treatment before the application of the ink composition. Preferred pretreatment agents have at least a size agent and a hydrotrope agent. Further, for dyes having excellent coloring properties in an acidic region, the dyes are preferably used during fixing.
A pH adjuster is added to the pretreatment formulation to make H. The pre-treatment is performed by applying a pre-treatment agent containing these to a fabric in advance.

According to a preferred embodiment of the present invention, the sizing agent is selected from natural gums such as guar and locust bean, starches such as carboxymethylcellulose, locust bean gum and british gum, sodium alginate, peptin and carboxymethyl ether. Preferably, at least one selected from the group consisting of:

As a preferred pH adjuster of the present invention, an acid ammonium salt such as ammonium sulfate, ammonium tartrate, or sodium diphosphate is used. The amount of these additives varies depending on the type of dye, but is 0.2 to 5%.
o. w. p, preferably 0.5-3% o. w. p. By adding these pH adjusters, hue stabilization and improvement in dyeing properties can be achieved.

The application of the pretreatment agent may be performed according to a conventional method, for example, a padding method. The mangle pressure, speed, drying time and the like at that time may be determined as appropriate.

According to a preferred embodiment of the present invention, the squeezing ratio during padding is preferably about 40 to 90%, more preferably about 60 to 80%. Increasing the aperture ratio is effective in improving the fixing density.

The ink-jet printing method of the present invention includes a so-called piezo head type in which ink droplets are formed and discharged by mechanical volume change of a piezoelectric element. A droplet is formed and the ink stored in the nozzle head portion to be discharged is heated rapidly at a portion very close to the discharge portion to generate bubbles, and the bubbles are intermittently discharged by volume expansion due to the bubbles, and the surface of the recording medium is discharged. And a thermal jet type.

The preferred recording method of the present invention is an ink-jet printing method using a piezoelectric element. The piezo type is extremely excellent in durability and is most suitable for the field requiring stable ejection for a long time as in the present invention. In addition, the ink of the present invention is particularly excellent in matching with a piezo-type print head, and achieves stable continuous ejection for a long time in a wide temperature range. This is suitable for the field of ink-jet printing of a long object requiring enormous ejection.

When the ink of the present invention is filled into a piezo-vibrator type ink jet print head and discharged, it is desirable that the surface of the nozzle plate of the print head is subjected to an ink repellent treatment. By performing the ink-repellent treatment, it is difficult for the ink to bend in flight, and an image having excellent reproducibility is printed on a desired cloth.

It is preferable that the ink repellent treatment is also applied to the inner surface of the nozzle hole. By applying the ink to the inner surface, the position of the ink meniscus is stabilized, and the ejection stability is further improved. Further, it is difficult for ink to come out on the nozzle plate surface, and the ink repellency of the nozzle surface can be maintained for a longer time.

The nozzle plate is drilled with a desired diameter. The constituent materials are metal, ceramics, silicon,
Made of glass, plastic, etc., preferably titanium,
Single material such as chromium, iron, cobalt, nickel, copper, zinc, tin, gold, etc. or alloys such as nickel-phosphorus alloy, tin-copper-phosphorus alloy, copper-zinc alloy, stainless steel, polycarbonate, polysulfone, acrylic nitrile -Butadiene-styrene copolymer, polyethylene terephthalate,
It is desirable to be formed of polysulfone and various photosensitive resins.

The method for treating the surface of these materials with ink is not particularly limited. For example, the material is immersed in an electrolyte in which nickel ions and water-repellent polymer resin particles are dispersed by electric charges, and immersed while stirring the solution. The preferred method is to perform eutectoid plating on the surface of the nozzle plate. As a water-repellent polymer resin material used for this eutectoid plating, a resin such as polytetrafluoroethylene, polyperfluoroalkoxybutadiene, polyvinylidene, polyfluorovinyl, polydiperfluoroalkyl fumarate or the like is used alone or in combination. It is preferred to use. The metal material does not need to be limited to nickel, and for example, copper, silver, tin, zinc and the like can be appropriately selected. Preferably, nickel, a nickel-cobalt alloy, a nickel-boron alloy, or the like, having a high surface hardness and excellent abrasion resistance are preferable.

According to a preferred aspect of the present invention, it is desirable that the ink ejection amount is 120 dots / inch or more and the ink ejection amount in solid printing is 5 g / m 2 or more. If the ejection density is 120 dots / inch or more, the printed material is less grainy. Further, if the dark and light inks are used in combination, a better printed image can be achieved. When the ink ejection amount exceeds 5 g / m2, it is easy to express high density printing.

The cloth to which the ink composition has been attached is subjected to post-treatment, and is fixed to the fibers. Further, it is preferable that the unfixed colorant and other ink compositions are sufficiently removed by the washing step. According to a preferred embodiment of the present invention, the post-treatment is divided into several steps. First, after the ink composition is adhered to the fabric, the fabric is cooled to a room temperature to 120 ° C.
It is preferable to leave the ink for 0.5 to 30 minutes to pre-dry the ink. This preliminary drying is effective for improving the printing density and preventing bleeding. In addition, this preliminary drying includes that the ink permeates into the fabric.

Further, it is preferable that the pre-dried fabric is further fixed by steaming. Preferred conditions are humidity 5
0-100% (more preferably humidity 80-100%) and temperature 90-120 ° C (preferably 95-105 ° C)
In the above environment for 3 to 130 minutes (preferably 5 to 90 minutes) to perform the fixing process. Further, after fixing, it is preferable to wash with warm water containing at least a nonionic surfactant. The printing cloth post-processed based on such a process has excellent coloring and reduced ink bleeding.

It is preferable to change the conditions of the fixing step in the post-processing step depending on the type of the cloth. In particular,
It is preferable to change the time. For example, if the fabric is wool, the time is 20-120 minutes, preferably 30 minutes.
About 90 minutes is preferable. When the cloth is silk, the time is preferably 5 to 40 minutes, and more preferably about 15 to 30 minutes. When the fabric is nylon, it is 5 to 90 minutes, preferably 10 to 90 minutes.
About 60 minutes is preferable. The printing cloth post-processed in such a process is excellent in color development and fastness, and reduces ink bleeding.

[0054]

EXAMPLES The contents of the present invention will be clearly described by the following examples, but the scope of the present invention is not limited to the following examples. Example 1 After weighing 50 g of Reactive Yellow 3 and dissolving it in 500 ml of water, 5 g of caustic soda was added. After dissolving the caustic soda at room temperature, the solution was stirred at 90 ° C. or higher for another 2 hours. (Example-2) 50 g of Reactive Orange 5 was dissolved in 500 ml of water, and then 10 g of potassium hydroxide was added and dissolved at room temperature. The rest was the same as in Example-1. Example 3 50 g of Reactive Green 12 and 15 g of caustic soda were dissolved in 700 ml of water. Thereafter, the solution was stirred at 80 ° C. for 4 hours. Example 4 The procedure was the same as in Example 1 except that the dye was changed to Reactive Red 5. (Example-5) Same as Example-2 except that the dye was changed to Reactive Black 4. (Example-6) It was the same as Example-3 except that the dye was changed to Reactive Blue 49. (Example-7) A sequestering agent (0.01% based on the dye) was added to the dyes of Examples 1 to 6, and salted out with a purified salt, followed by filtration.
The resulting dye is further dissolved in pure form,
Next, it was purified. (Example-8) Purification was performed in Example-7, and the obtained dye was developed by thin-layer chromatography. As a result, sufficient purification was confirmed. The developing solution was a mixed solvent of alcohols 40, aqueous ammonia 5, and dimethylformamide 10. (Example-9) A 5% aqueous solution of each of the dyes purified in Example-7 was prepared, and each solution was adjusted to pH = 9 with triethanolamine.
Adjusted back and forth. The solution was left at 60 ° C. for 7 days,
The H change was measured. pH meter made by Yokogawa pH meter 82
Was measured at 20 ° C. The results are shown below. In the table, for example, the actual dye 1 indicates the dye prepared in Example-1.

[0055]

[Table 1]

When the reactive dye aqueous solution is left under a high temperature under an alkali, hydrolysis proceeds and the pH decreases. However, the dye solution treated in the present invention has a maximum pH change of 0.2 and the dye solution has It turns out that it is extremely stable. (Example-10) The amounts of caustic soda and potassium hydroxide used as alkaline agents in Examples-1 to 6 were changed to 0.5 to 20% with respect to the dye, and the results were the same as in Example-9. Met. Example 11 An ink jet textile printing ink was prepared as follows. Residual water was added so that the total amount of ink became 100 grams. The numbers in the table indicate percent by weight. After the preparation of the inks, each of the inks was adjusted to a pH of about 8.5 with triethanolamine.

[0057]

[Table 2]

Example 12 The inks prepared in Example 11 and the actual inks 1 to 6 were allowed to stand at 60 ° C. for 7 days, and the pH was measured.

[0059]

[Table 3]

The change in pH of the ink was 0.3 at the maximum before and after being left at 60 ° C., and was stable. Example 13 The ink prepared in Example 11 was filled in an Epson printer EM-900C,
Printed at 35 ° C. The number of prints is 1 for A4 under each condition.
It was 0000 sheets. Printing was performed at 1,000 sheets / day for a total of 10 days. Regarding the ejection state of each ink, the ejection was extremely stable regardless of before or after the ink was left at a high temperature. (Example-14) 12 padded with a pretreatment agent mainly composed of sodium alginate, CMC, urea, and an organic acid
Ink created in Example-11 on momme silk, actual ink 1
The actual ink 6 was printed. The printer was EM-900C. The print was steamed at 102 ° C., 100% for 30 minutes. Further, the printed matter was obtained by washing with water, washing with hot water, washing with a nonionic activator hot water solution, washing with hot water, washing with water, and ironing. All the inks were printed well by visual evaluation. (Example 15) Embodiment of the invention A printed product was obtained in the same manner as in Example 14 except that each ink was allowed to stand at 60 ° C for 7 days. The print density of Example-15 was almost the same as the density of Example-14. (Comparative Example-1) Reactive Yellow 3 (RY-3),
Reactive Orange-5 (RO-5) and Reactive Green-12 (RG-12) were purified as in Example-7. Thereafter, a 5% aqueous solution of each dye was prepared, and each solution was adjusted to about pH = 9 with triethanolamine. This solution was left at 60 ° C. for 7 days, and the pH change was measured. pH
The meter was measured at 20 ° C. using a pH meter 82 manufactured by Yokogawa. The results are shown.

[0061]

[Table 4]

The pH of the aqueous solution of the reactive dye of Comparative Example 1 was greatly reduced by being left at a high temperature under an alkali. This is presumed that the reactive group was hydrolyzed and the dye itself changed. (Comparative Example-2) Of the inks prepared in Example-11, actual dyeing 1 was changed to reactive yellow 3 (RY-3), and actual dyeing 2 was changed.
Was replaced with Reactive Orange-5 (RO-5) and Real Dye 3 was replaced with Reactive Green-12 (RG-12). These inks have a pH =
8.5 was adjusted with triethanolamine. The pH change of each ink at the initial stage and after standing at 60 ° C. for 7 days is described.
The ink names are specific ink 1 to specific ink 3 and correspond to real ink 1 to real ink 3 except that the dye is changed as described above.

[0063]

[Table 5]

The hydrolysis of the dyes constituting the ink proceeded, and the pH dropped significantly. (Comparative Example 3) A test similar to that of Example 13 was performed except that the ink prepared in Comparative Example 2 was used. After printing about 9000 sheets at 10 ° C., the nozzle was bent and non-discharge appeared.
In addition, it did not recover even when the cleaning mechanism of the printer was activated. Observation of the print head after the ejection of 10,000 sheets revealed that the eutectoid plating film was corroded and the water repellency was deteriorated. For this reason, stable ejection could not be obtained.

At 25 ° C., the same phenomenon as at 10 ° C. was observed after 8000 sheets.

At 35 ° C., the same phenomenon was observed after 6,500 sheets were discharged. When the cleaning mechanism of the printer was activated after discharging 9000 sheets, the discharge characteristics were further deteriorated. When the print head was observed, the eutectoid plating was peeled off.
This is considered that the plating itself was peeled off by the cleaning. As described above, the ink in the acidic region damaged the print head, and stable ejection was not obtained. (Comparative Example 4) The ink used in Comparative Example 2 before standing at high temperature was printed and fixed on silk under padding. The steps from printing to ironing are the same as in Example-14. The printed matter was good visually as in Examples 14 and 14. (Comparative Example-5) A printed material was obtained in the same manner as in Comparative Example-4, except that the ink was left at 60 ° C for 7 days. Comparative Example-4 and Comparative Example-
The printed matter of No. 5 was greatly different in hue. It is believed that the color development was different because the ink was left at a high temperature.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D06P 3/10 D06P 5/00 112 5/00 111 B41J 3/04 101Y 112 103N (72) Inventor Hirokazu Yanagihara 3-3-5, Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Go Hasegawa 5-7-1 Shinnakazato, Saitama-shi, Saitama F-term in Daiwa Kasei Corporation (reference) 2C056 FA04 FB03 FC02 FC02 HA24 HA44 2C057 AF41 AG07 AJ03 AP55 AP60 AQ06 2H086 BA22 BA31 BA52 BA56 BA59 BA60 BA61 4H057 AA01 AA02 BA07 CA12 CA29 CA33 CA90 CB14 CB22 CC01 CC02 DA01 DA21 GA06 4J039 BA12 BC07 BC09 BC13 BC19 BC33 BE34 BE22 BE32 BE32 BE32 BE32 BE32 BE32 BE32 BE32 BE30

Claims (15)

[Claims] 1. A reactive dye having a reactive group reacted by 50% or more in advance, an organic solvent having a boiling point of 150 ° C. or more at normal pressure, and water, and having a viscosity of 8.0 mPs (20 ° C.).
An ink composition for inkjet printing, which is as follows. 2. The ink composition according to claim 1, wherein the salt as an impurity derived from the dye has a concentration of 1% by weight or less. 3. The ink composition according to claim 1, comprising an alkylene glycol alkyl ether as the organic solvent having a boiling point of 150 ° C. or higher. 4. The ink composition according to claim 1, comprising a polyhydric alcohol as the organic solvent having a boiling point of 150 ° C. or higher. 5. The method according to claim 1, further comprising a pyrrolidone compound.
5. The ink composition according to any one of claims 1 to 4. 6. The ink composition according to claim 1, further comprising a surfactant. 7. The ink composition according to claim 1, further comprising a sequestering agent. 8. The ink composition according to claim 1, which comprises at least ethylenediaminetetraacetic acid or a salt thereof, or hydroxyethylethylenediaminetriacetic acid. 9. The ink composition according to claim 1, wherein the pH is adjusted to 6.0 to 11.0. 10. An ink-jet printing method in which ink droplets of an ink composition are ejected and the ink droplets are attached to a fabric containing animal fiber or amide fiber, wherein the ink composition is used as the ink composition. An ink-jet printing method, wherein the fabric is preliminarily coated with a pretreatment agent containing at least a sizing agent and a hydrotrope agent, using the ink composition according to any one of items 9 to 9. 11. An ink-jet printing method, wherein the ink-jet printing ink according to claim 1 is printed by an ink-jet print head using a piezo vibrator. 12. Ink jet printing, wherein the ink jet printing ink according to any one of claims 1 to 9 is filled into a piezo vibrator type ink jet print head provided with an ink repellent film layer on a nozzle surface, and printing is performed. Method. 13. The ink-jet printing method according to claim 11, wherein a part of the ink-repellent film is inserted into the inner surface of the nozzle. 14. The ink jet printing method according to claim 11, wherein the ink repellent film layer is formed by eutectoid plating. 15. A fabric printed by the ink jet printing method according to claim 11. Description: