JPH0593375A - Inkjet printing method - Google Patents

Abstract

(57) [Summary] [Objective] The dyed fabric is limited to a fabric mainly composed of cellulose fibers, and the conventional general ink jet printing problem as described above, that is, a dyed product having a clear and high density To provide a printing method which simultaneously satisfies both the dyeing problem of obtaining a high quality and the discharge performance problem of enabling stable and reliable printing for a short period or a long period of time. [Structure] 5 for fabric mainly composed of cellulose fibers
-30% by weight of a reactive dye having no dichlorotriazine group, an alkaline substance and an aqueous liquid medium, and at least 5 to 50% by weight of thiodiglycol in the liquid medium, a small liquid of a printing ink having a pH of 9 or more. After the droplets are caused to fly by thermal energy and applied, and the dye in the ink is dyed on the cloth by heat treatment, the undyed dye is washed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing fabrics (woven fabric or non-woven fabric) by an ink jet method using heat energy, and when using a fabric containing cellulosic fibers, a clear and delicate pattern is provided. The present invention relates to a printing method using an inkjet method.

[0002]

2. Description of the Related Art The mainstream of current printing is screen printing,
Roller printing. Since these methods are not suitable for high-mix low-volume production, and it is difficult to respond quickly to trends, it has recently been desired to establish a plateless electronic printing system. In response to this demand, many printing methods using ink jet recording have been proposed, and expectations from various fields are increasing.

Problems of ink jet printing include:
(1) Sufficient density for color development, (2) Do not clog the nozzles of the head, (3) Ink dries quickly on the fabric, (4) Little irregular bleeding on the fabric (5) The ink does not undergo changes in physical properties during storage, precipitation of solids, etc. (6) No change in ejection characteristics during long-term durability.
In the case of the method of ejecting ink by utilizing the volume change due to thermal energy described in Japanese Patent Publication No. 4-59936, there is no deposition of foreign matter on the heater which gives thermal energy, and the heater is destroyed by cavitation during defoaming. Not occur, (7) process is simpler,
Etc.

In order to satisfy these problems, the following measures have hitherto been taken. First, with respect to (1), it is a general means to increase the concentration of the dye in the ink to give a sufficient concentration, and in particular, 20
This is an indispensable technique when small droplets of 0 pl or less are used or when the cloth has a strong absorbing power. However, when such an ink is used, the viscosity is increased due to the evaporation of the ink from the nozzle tip, and the dye that is a solid content is deposited, which causes the problem (2). Therefore, for (2), measures such as adding polyhydric alcohols such as glycerin to the ink have been taken, but when the dye concentration exceeds 5%, a solution that can be said to be particularly complete. There is no solution and no satisfactory result is obtained except for a very specific combination of dye and solvent.
With respect to (3), the water repellency of the cloth has a great influence, but there is no particular problem when the water-based ink is used for the cloth mainly composed of cellulose fibers. With respect to (4), many proposals have already been made to deal with the use of ink, for example, tannin in JP-A-61-231289 and addition of a carboxylic acid group-containing polymer to ink in JP-A-62-283174. However, in any case, the problem (2) is unavoidable. With respect to (5) and (6), there is a case where they are caused by the structure of the dye or the influence of the pH of the ink, etc., but detailed studies have not been made and a sufficient problem has not been solved. With regard to (7), since it is a plateless method, it is much simpler than the conventional method, but there is room for improvement such as in which step the alkali treatment is performed.

As described above, in the conventional technique, an ink jet printing method for satisfying these performances at the same time and solving the series of problems can be found even if a means for individually satisfying each performance can be found. The current situation is that there are none.

[0006]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to limit the cloth to be dyed to a cloth composed mainly of cellulose fibers, and to solve the above-mentioned problems of conventional general ink jet printing, namely, To provide a printing method that simultaneously satisfies a dyeing problem of obtaining a clear and high-density dyeing product and a discharge performance problem of enabling stable and reliable printing for a short period or a long period of time. Is. Such an object of the present invention is achieved by the following present invention.

[0007]

Means for Solving the Problems That is, according to the present invention, (a) a step of ejecting small droplets of a printing ink by thermal energy to a cloth mainly composed of cellulose fibers, and (b) a heat treatment An inkjet printing method comprising at least three steps of dyeing a dye in the ink and (c) washing an undyed dye, wherein the printing ink contains 5 to 30% by weight of dichloro. It is composed of a reactive dye having no triazine group, an alkaline substance and an aqueous liquid medium, and at least 5 in the liquid medium.
An inkjet printing method is characterized in that an ink having a pH of 9 or more containing -50% by weight of thiodiglycol is used.

[0008]

The function of the inventor of the present invention is as follows.
As a result of improving the ink so as to simultaneously satisfy the various required performances as described above by paying attention to the ink having a large influence, a certain amount of thiodiglycol was added to the high concentration aqueous ink using the reactive dye of 5 to 30% by weight. It has been found that the inclusion of the compound can significantly improve the color development properties such as level dyeing property and dyeing rate. This phenomenon seems to be due to some effect of thiodiglycol that maximizes the reaction characteristics of the dye at the molecular level.

Further, it has been found that by containing thiodiglycol, in this dye system, stable discharge characteristics for a long period of time, which cannot be considered with conventional solvents, can be obtained. This effect is particularly remarkable when an inkjet head utilizing heat energy is used. The reason for this is that the interaction between the reactive dye and thiodiglycol suppresses the occurrence of deposit properties on the head. It is conceivable that the ink thickening at the nozzle tip portion is specifically suppressed in this combination.

Further, it has been found that, even if the pH of the ink is 9 or more except for a specific reactive group, the hydrolysis of the dye is slight and the dyeing rate of the ink is not lowered at the actual use level in the factory. did.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The ink jet printing ink used in the present invention comprises at least 5 to 30% by weight of a reactive dye having no dichlorotriazine group and an aqueous liquid medium, and contains an alkaline substance and a certain amount of thiodiglycol. It is characterized by containing.

The first characterizing substance of the ink used in the present invention is thiodiglycol, and the content in the ink is 5 to 50%, preferably 7 to 45%, more preferably 10 to 45%. It is in the range of 40%. When the content of thiodiglycol is 5% or less, not only the effect of improving the color developability is insufficient, but also the storage stability of the ink is deteriorated and non-ejection due to thickening due to ink evaporation near the nozzle tip is caused. .. In addition, if the content exceeds 50%, in addition to the problem of color developability, the storage stability of the ink deteriorates as in the case of less than 5%. Regarding the ejection characteristics, the response to the frequency becomes extremely poor. There is also a problem of non-ejection in a short-term standing state due to an increase in the initial viscosity of the ink. Almost all types of dyes can be used as long as they are reactive dyes having no dichlorotriazine group, but those having monochlorotriazine and vinylsulfone groups are particularly preferable.

Specific examples include, but are not limited to, these dyes. I. Reactive yellow 2,1
5,37,42,76,95 C.I. I. Reactive Red 21, 22, 24, 33, 45, 111, 112,
114, 180, 218, 226 C.I. I. Reactive Blue 15,19,21,38,49,72,7
7,176,203,220 C.I. I. Reactive Black 5, 8, 31, 39 and the like can be mentioned. The amount of these dyes used is generally 5 with respect to the total amount of ink.
-30% by weight, preferably 6-25% by weight, more preferably 8-20% by weight.

Water, which is an essential component of the ink, is 30 to 95% by weight, preferably 40 to 9% by weight based on the total amount of the ink.
It is 0% by weight, more preferably 50 to 85% by weight. The above are the essential components of the ink used in the present invention, but general organic solvents can also be used in combination with thiodiglycol. For example, ketones such as acetone and diacetone alcohol or keto alcohols; tetrahydrofuran,
Ethers such as dioxane; oxyethylene or oxypropylene addition polymers such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol; ethylene glycol, propylene glycol, trimethylene glycol, Alkylene glycols in which the alkylene group such as butylene glycol, 1,2,6-hexanetriol, hexylene glycol contains 2 to 6 carbon atoms; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) Lower alkyl ethers of polyhydric alcohols such as ether and triethylene glycol monomethyl (or ethyl) ether Triethylene glycol dimethyl (or ethyl) ether, tetraethylene glycol dimethyl (or ethyl) lower dialkyl ethers of polyhydric alcohols such as ether; sulfolane, N- methyl -
2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-
2-imidazolidinone etc. are mentioned.

The content of the water-soluble organic solvent is generally in the range of 0 to 50% by weight, preferably 2 to 45%, based on the total weight of the ink.

When the above mediums are used in combination, they can be used alone or as a mixture, but the most preferable liquid medium composition is one in which the solvent contains at least one polyhydric alcohol and its derivative. Among them, diethylene glycol, triethylene glycol, triethylene glycol monomethyl ether and tetraethylene glycol dimethyl ether are particularly good.

Regarding other substances contained, it is preferable to add 1 to 30 ppm of calcium and / or magnesium in a range that does not cause clogging, because the color development characteristics such as level dyeing property and dyeing ratio can be further improved. Further, by containing 0.3 to 10 ppm of a substance consisting of a group of silicon, iron, nickel and zinc, more stable ejection characteristics can be obtained over a long period of time. It is also good to add a trace amount if necessary. This effect is particularly remarkable when an inkjet head utilizing heat energy, which is a feature of the present invention, is used. The reason for this is that an excessive content of these substances causes a decrease in the foaming power due to deposits on the head, but the formation of a deposit by moderate addition causes cavitation during defoaming without causing a decrease in the foaming power. To alleviate and prevent disconnection. The main components of the ink used in the present invention are as described above, but various other dispersants, surfactants, viscosity modifiers, surface tension modifiers, optical brighteners, etc. are required within the range where clogging does not occur. Can be added according to

For example, viscosity adjusting agents such as polyvinyl alcohol, celluloses and water-soluble resins; various anionic, cationic or nonionic surface active agents; surface tension adjusting agents such as diethanolamine and triethanolamine; buffer agents, antifungal agents. Etc. can be mentioned.

The outline of the constitution of the ink used in the present invention is as follows.
As described above, the pH is adjusted to 9 or higher, preferably 9.5 or higher, more preferably 10 or higher by adding an alkaline agent such as sodium hydroxide, lithium hydroxide or sodium hydrogencarbonate at the end of ink preparation. .. The ink is preferably used within 24 hours, more preferably within 8 hours after production.

When the ink used in the present invention is used, the use of an alkali-treated cloth or an alkali pad treatment is unnecessary, and therefore the textile printing process can be greatly simplified.

The ink jet printing method of the present invention is a method using the above ink, and the ink jet recording method is, for example, the method described in JP-A-54-59936. This is a system in which the ink subjected to the action of thermal energy causes a rapid volume change, and the action force resulting from this state change causes the ink to be ejected from the nozzle. By using the above ink in such a system, even if recording is continuously performed for a long time, deposition of foreign matter or disconnection does not occur on the heating head, and stable printing is possible.

This method is considered to be the most suitable method, although it is particularly strict with respect to ink for ink jet printing, since it is easy to make multiple fine nozzles and high-speed printing with a wide width is possible.

In particular, when the above ink is used and a particularly effective printing method is obtained, 20 to 20 ejected liquid droplets can be obtained.
It is preferable that the ink ejection amount is 200 pl, the ink ejection amount is 4 to 40 nl / mm ² , the driving frequency is 1.5 KHz or more, and the head temperature is 35 to 60 ° C.

The cloth used in the present invention is limited to those mainly composed of cellulose fibers.

With the above-mentioned constitution, the printing ink is applied onto the cloth, but the dyeing is insufficient in this state. Therefore, the reaction fixing and the dye removing step by the heat treatment of the dye on the fiber are essential. Such reaction fixing and removal of unreacted dye may be a conventionally known method, for example,
It can be carried out according to a conventionally known method of washing after treatment by a steaming method, an HT steaming method, a thermofix method, or the like.

[0026]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. First, the ink used in the present invention will be described. In the text, "%" and "%" are based on weight. Ink example 1

[0027]

[Table 1] Mix all the above components and pH the mixture with sodium hydroxide.
The mixture was adjusted to 10.3, stirred for 2 hours, and then filtered with Fluoropore Filter FP-100 (trade name, manufactured by Sumitomo Electric Co., Ltd.) to obtain an aqueous ink (A).

Ink example 2

[0029]

[Table 2] Aqueous ink (B) was obtained in the same manner as in Ink Example 1 except that all the above components were used.

Ink example 3

[0031]

[Table 3] An aqueous ink (C) was obtained in the same manner as in Ink Example 1 except that all the above components were used.

Ink example 4

[0033]

[Table 4] Aqueous ink (D) was obtained in the same manner as in Ink Example 1 except that all the above components were used.

Ink example 5

[0035]

[Table 5] An aqueous ink (E) was obtained in the same manner as in Ink Example 1 except that all the above components were used.

Ink example 6

[0037]

[Table 6] Aqueous ink (F) was obtained in the same manner as in Ink Example 1 except that all the above components were used.

Ink example 7

[0039]

[Table 7] An aqueous ink (G) was obtained in the same manner as in Ink Example 1 except that all the above components were used.

Examples and Comparative Examples Each of the water-based inks (A to G) of Examples 1 to 7 was prepared as in JP-A-54-5.
Using a head for color bubble jet copier Pixel pro (trade name, manufactured by Canon) (nozzle number 256, flying droplets 20 to 40 pl), which is an inkjet head by the action of thermal energy, described in Japanese Patent No. 9936. When continuous printing of 5 × 10 ⁸ pulses was performed with this nozzle, the presence or absence of clogging of the nozzle, decrease in the amount of discharged liquid droplets, decrease in discharge speed, and the like were examined. Also, after printing the alphanumeric characters continuously for 3 minutes with the same head, stop the printing, leave it for 3 minutes without the cap, and then print the alphanumeric characters again to check if the characters are scratched or missing. Examined. Further, the same head was used to continuously print alphanumeric characters for 3 minutes, then the printing was stopped, and the printing was left for 1 day without the cap, and the clogging due to the adhesion of solid matter near the tip of the nozzle was examined.
(Each head was heated to a temperature in the range of 45 to 60 ° C.) Further, 100 cc of each water-based ink (A to G) was put in a glass bottle and stored at 40 ° C. for 1 day to examine the storage stability of the ink. It was The evaluation results of the ink are shown in Table 1.

Further, the water-based inks (A to G) of Examples 1 to 7 were mounted on a color bubble jet copier Pixel pro (trade name, manufactured by Canon) and printed on a 100% cotton georgette fabric at 100 ° C. Fixing was performed by steam heat treatment for 2 minutes, and then washed with a neutral detergent to evaluate the sharpness and bleeding property of the dyed product. The results are shown in Table 2. (For printing, a solid sample of 2 × 10 cm was prepared under the condition that the ink injection amount was 16 nl / mm ^2. )

[0042]

[Table 8] * 1: The number of nozzles that did not cause nozzle clogging, decrease in the amount of discharged liquid droplets, or decrease in the discharge speed when continuous printing of 5 × 10 ⁸ pulses was performed with 10 nozzles. ◯: 10 lines Δ: 6 to 9 lines ×: 5 lines or less * 2: After continuous printing for 3 minutes, it was left for 3 minutes without a cap and reprinted. ◯: No defects from the first letter. Δ: A part of the first character is scratched or chipped. X: The first character cannot be printed at all. * 3: A state of clogging due to the adhesion of solid matter near the tip of the nozzle when left for 1 day without a cap after continuous printing for 3 minutes. ◯: No clogging. Δ: Clogging occurred but recovered by suction. X: The clogging does not recover even when sucked. * 4: After the ink was stored at 40 ° C. for 1 day, it was visually determined whether or not foreign matter was generated in the glass bottle. ◯: No foreign material △: Small foreign material generated ×: Large foreign material generated

[0043]

[Table 9] * 1: Judged by the sharpness of the pattern when observed with the naked eye. ◯: Good Δ: Slightly inferior ×: Inferior * 2: Observed with naked eyes. ◯: Good Δ: Slightly inferior X: Inferior

[0044]

As described above, according to the ink-jet printing method of the present invention, a dyed cloth having a high density can be obtained without bleeding with respect to a cloth mainly composed of cellulose fibers. It becomes possible. Further, according to the ink of the present invention, it is possible to perform printing with high reliability of ejection performance without causing clogging of head nozzles in inkjet printing. In particular, it is remarkably good in recording of a type in which ink is ejected due to the bubbling phenomenon of ink due to thermal energy.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (1)

[Claims] 1. A step of (a) a step of flying small droplets of a textile printing ink by applying thermal energy to a cloth mainly composed of cellulose fibers, and (b) a heat treatment to dye the dye in the ink on the cloth. In the inkjet printing method, which comprises at least three steps, a step of applying the dye and a step of washing the undyed dye (c), the printing ink is 5 to 3
0% by weight of reactive dye having no dichlorotriazine group,
An ink jet printing method comprising using an ink having a pH of 9 or more, which is composed of an alkaline substance and an aqueous liquid medium and contains at least 5 to 50% by weight of thiodiglycol in the liquid medium.