JP2008223193A - Pre-treating agent for inkjet printing, fabric treated with the pre-treating agent, and method for inkjet printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pre-treating agent which is used in a state combined with a printing inkjet ink containing a disperse dye and can prevent the flying deflection of ink liquid drops in inkjet printing, to provide a fabric treated with the pre-treating agent, and to provide a method for inkjet printing for the fabric. <P>SOLUTION: This pre-treating agent contains a surfactant. The pre-treating agent, wherein the printing inkjet ink is an ink dispersed with an anionic dispersant, and the surfactant is a cationic surfactant. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pretreatment agent for inkjet printing, a fabric treated with the pretreatment agent, and an inkjet printing method.

  Ink jet printing is a method in which small droplets of ink are ejected and adhered to a recording medium such as paper or a transparency film. This method can print a high-resolution and high-quality image at a high speed with a relatively inexpensive apparatus.

  Ink-jet printing methods in which this ink-jet printing method is applied to textile printing are various inks that have excellent gradation and multi-color expression, for example, because ink droplets are ejected and adhered to various pre-treated fabrics. This image can be easily formed on a fabric. Ink jet textile printing is also effective for environmental conservation because it generates almost no excess ink in the conventional printing process.

However, in inkjet printing, it is necessary to divide the components of conventional printing ink into components that are included in the ink and components that are included in the pretreatment agent, and the inkjet ink for printing is adjusted to a low viscosity suitable for inkjet. It is necessary.
Various pretreatment agents have been proposed in order to achieve a printing density and sharpness comparable to those of conventional screen printing methods by the inkjet printing method. For example, an aqueous pretreatment agent containing a polyethylene oxide resin having a viscosity average molecular weight of 100,000 or more has been proposed in addition to a paste, urea and an alkali agent, which are basic blending components of an ordinary pretreatment agent (Patent Document 1). ), And a high-density image having a depth without blur on the fabric can be recorded.
JP-A-8-127982

The inventor has been diligently researching to improve the quality of ink-jet printing, and has found that printing spots that have not been reported in the past are generated in the field of ink-jet printing. It has also been found that it is caused by sub-dots generated accompanying the main dots.
In general, in an inkjet recording method, unintended small droplets are generated on the recording medium along with main dots formed by the droplets ejected from the printer head adhering to the recording medium. A phenomenon in which sub-dots are recorded is known. For example, as shown in FIG. 1, when target main dots M1, M2, and M3 are ejected and formed on the surface of the recording paper, they are attached to the main dots M1, M2, and M3 and sub-dots respectively. S1, S2, and S3 are discharged and formed. Since these sub-dots are generated in association with the main dots, they are also called satellite dots, and the printing spots formed by these sub-dots (satellite dots) are called wind ripples. Such a phenomenon occurs because the minute dots are particularly affected by the wind pressure accompanying the high-speed carriage movement. Further, since the wind ripples are likely to appear as the distance between the printer head and the recording paper increases, the influence can be minimized by bringing the printer head and the recording paper close to each other.

On the other hand, the printing spot discovered by the inventor in the ink-jet printing is caused by the sub-dots Sa, Sb, Sc distributed irregularly with respect to the positions of the main dots M1, M2, M3 as shown in FIG. Yes. In addition, when the printer head and the fabric are brought close to each other, the irregularity of the distribution is increased and the printing quality is deteriorated. When the main dot is a small droplet, the regularity of the arrangement of the main dot itself may be disturbed. Such a phenomenon of dot deflection in ink jet textile printing has not been reported at all so far, and the present inventor has found out that the cause is an electrostatic action caused by charging of the fabric.

  In general, a manufacturer of a fabric provides the fabric in a state of being subjected to an antistatic treatment. However, in inkjet printing, it is necessary to perform a pretreatment on the fabric. In the pretreatment operation, a pretreatment agent containing a resin (insulator) is attached to the fabric by a coating method or a padding method, so that the effect of the antistatic treatment originally applied to the fabric is lost or reduced. In the inkjet printing method, the long fabric is wound and stored in the roll state after the pretreatment operation, and the long fabric is unwound from the roll state and conveyed to the printing machine when performing the inkjet printing. It is charged when it is wound into the roll state, and further charged when it is rewound from the roll state.

Since the fabric is charged, the ink droplets cause flight bending, and printing spots are generated. The electrostatic action is more affected as the droplets are smaller, and the effect is greater as the printer head and the fabric are closer to each other. In ink jet textile printing, the distance between the printer head and the fabric is about 2 mm and is very close to each other, so that it is greatly affected by electrostatic action. If the droplet size is increased to about 20 pL, for example, the influence on the main dot can be avoided. However, in the ink jet recording method, the sub dot is always generated, and the sub dot is usually 10 pL or less. Will be greatly affected.
Such phenomena and problems have not been raised at all in the past, and therefore no solution has been proposed. Accordingly, it is an object of the present invention to provide means for preventing deterioration in printing quality due to ink droplet deflection in ink jet printing.

  According to the present invention, the above-mentioned problem is a pretreatment agent that is used in combination with a printing inkjet ink containing a disperse dye, and that contains a paste and contains an antistatic agent. Can be solved by.

The pretreatment agent according to a preferred embodiment of the present invention is an ink in which an inkjet ink for textile printing is dispersed with an anionic dispersant, and the antistatic agent is a cationic antistatic agent.
The pretreatment agent according to another preferred embodiment of the present invention further contains an acidifying agent and water.
The pretreatment agent of still another preferred embodiment of the present invention further contains a hydrotropic agent.
The present invention also relates to a fabric (particularly polyester, acetate or a blend thereof) treated with the pretreatment agent.
Furthermore, the present invention also relates to an inkjet printing method characterized by including a step of discharging a printing inkjet ink containing a disperse dye onto a fabric pretreated with the pretreatment agent.

  According to the present invention, it is possible to prevent the printing quality from being deteriorated due to the flight deflection of the ink droplets in the ink jet printing, the printer head and the fabric are close to each other, the discharge amount of the main dots is small, or the secondary ink is discharged. Even when dots are generated, high-quality printing can be realized.

[Pretreatment agent]
(Antistatic agent)
The pretreatment agent of the present invention contains an antistatic agent. As an antistatic agent, the antistatic agent normally used for the antistatic process of a fabric can be used. Specifically, aliphatic sulfonate, higher alcohol sulfate ester salt, higher alcohol ethylene oxide adduct sulfate ester, higher alcohol phosphate ester salt, higher alcohol ethylene oxide adduct phosphate ester salt, higher alcohol ethylene oxide adduct polyethylene glycol fatty acid ester And polyhydric alcohol fatty acid esters, quaternary ammonium salt cationic surfactants, or higher alcohol phosphate organic amines.
The above-mentioned antistatic agents can be used alone or in combination of two or more.

  In the pretreatment agent of the present invention, the content of the antistatic agent is not particularly limited and can be appropriately determined, but is preferably about 0.01 to 1% by weight, more preferably, based on the total weight of the pretreatment agent. It is about 0.05 to 0.5% by weight. By setting the content of the antistatic agent to 0.01% by weight or more, a sufficient antistatic effect can be obtained, and by setting the content to 1% by weight or less, printing bleeding can be suppressed.

  When an ink dispersed with an anionic dispersant is used as the inkjet ink for textile printing, it is preferable to use a cationic antistatic agent as the antistatic agent. In this case, the disperse dye dispersed with the anionic dispersant aggregates on the fabric, and a clear line and high concentration can be achieved.

(Hydrotropy)
The pretreatment agent of the present invention can contain a hydrotropic agent. As the hydrotropic agent, for example, urea such as urea, dimethylurea, thiourea, monomethylthiourea, or dimethylthiourea can be used.
Although content of a hydrotropic agent is not specifically limited, Preferably it is 1 to 15 weight% with respect to the total weight of a pretreatment agent, More preferably, it is 3 to 10 weight%. By setting the content of the hydrotropic agent to 1% by weight or more, a sufficient coloring effect can be obtained. By setting the content of the hydrotropic agent to 15% by weight or less, clogging of the head due to floating of the hydrotropic agent powder, or flight bending Can be avoided.

(Acidizing agent)
The pretreatment agent of the present invention can contain an acidifying agent. As the acidifying agent, for example, citric acid, tartaric acid, lactic acid or the like can be used.

(Glue)
The pretreatment agent of the present invention preferably contains a paste (resin). Examples of the paste include natural gums such as guar and locust bean, starches, seaweeds such as sodium alginate and fungi, plant skins such as pectic acid, methyl fibrin, ethyl fibrin, hydroxyethylcellulose, carboxymethylcellulose, etc. Fibrin derivatives, roasted starch, alpha starch, carboxymethyl starch, carboxyethyl starch, hydroxyethyl starch and other modified starches, processed natural gums such as roast bean gum, roast bean gum, algin derivatives, or polyvinyl alcohol, Synthetic pastes such as polyacrylic acid esters, emulsions, and the like are used, and these can be used alone or in combination.

  The content of the paste is not particularly limited, but is preferably 0.1 to 5% by weight, more preferably 0.3 to 2% by weight, based on the total weight of the pretreatment agent. By setting the content of the paste to 0.1% by weight or more, a sufficient bleeding prevention effect can be obtained, and by making it 5% by weight or less, high viscosity, difficult coating, and difficult padding are achieved. Can be avoided.

(Leveling agent)
The pretreatment agent of the present invention preferably contains a leveling agent. As the leveling agent, for example, polyhydric alcohol fatty acid ester, glycerin fatty acid ester, sorbitan fatty acid ester, or pentaerythritol fatty acid ester can be used. Polyhydric alcohol fatty acid ester [for example, commercially available from Nikka Chemical Co., Ltd. It is preferable to use the used sunflorene].
The leveling agent content is appropriately determined depending on the amount and type of the dye in the ink and is not particularly limited, but the leveling agent content is based on the total weight of the pretreatment agent. Preferably it is 0.1 to 5 weight%, More preferably, it is 0.3 to 2 weight%. By setting the leveling agent content to 0.1% by weight or more, a sufficient coloring effect can be obtained, and by setting it to 5% by weight or less, occurrence of bleeding can be prevented.

(water)
In the pretreatment agent of the present invention, water is the main solvent. As water, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, or distilled water, or ultrapure water can be used. In addition, use of water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be prevented when the pretreatment agent is stored for a long period of time.

(Other additives)
In order to improve color development, silica and / or alumina can be added in addition to the above-described components.

[Inkjet ink for textile printing]
(dye)
The pretreatment agent of the present invention is used in combination with a printing inkjet ink containing a disperse dye. Examples of the disperse dye contained in the inkjet ink for textile printing used in combination with the pretreatment agent of the present invention include C.I. I. Disperse Blue 60, 73, 87, C.I. I. Disperse thread 92, 146, 283, C.I. I. Disperse Yellow 93, 114, 163, C.I. I. Disperse Black 1 is exemplified.

(water)
In the inkjet textile printing ink used in combination with the pretreatment agent of the present invention, any water can be used as water, but pure water is preferably used. Pure water can be easily produced by ion exchange or distillation. Further, it is more preferable that the pure water is further sterilized with ultraviolet rays or the like.

(Metal sequestering agent)
Furthermore, the inkjet textile printing ink used in combination with the pretreatment agent of the present invention can contain a sequestering agent. As the metal sequestering agent, ethylenediaminetetraacetic acid (EDTA), EDTA salt (for example, sodium salt), hydroxyethylethylenediaminetriacetic acid (EDTA-OH) and the like are suitable.

(Other additives)
The inkjet textile printing ink used in combination with the pretreatment agent of the present invention has an alkylene glycol monoalkyl ether (for example, triethylene glycol) for the purpose of improving the ejection stability of the ink (particularly the ejection stability with a piezo head). Mono-n-butyl ether) can be added.
In addition, the inkjet textile printing ink used in combination with the pretreatment agent of the present invention preferably contains a preservative in addition to the above components. Preferable antiseptics include, for example, proxel CRL, proxel BDN, proxel GXL, proxel XL-2, proxel IB, or proxel TN.
Further, the textile printing ink contains a pyrrolidone-based solvent (for example, 2-pyrrolidone, N-methyl-2-pyrrolidone) or thioglycol, so that the solubility of the dye is increased, and the ejection stability is excellent even for a high concentration dye ink. Sex can be imparted.

  Furthermore, the inkjet textile printing ink used in combination with the pretreatment agent of the present invention contains the above-mentioned constituents as appropriate, but has a viscosity of 8.0 m · Pa · s or less at 20 ° C., preferably 1.5-6. 0.0 m · Pa · s is preferable. If it is 8.0 m · Pa · s or less, ink can be ejected at normal ambient temperature without any problem. Ink exceeding 8.0 m · Pa · s at 20 ° C. has poor ejection stability in a low temperature region.

[Inkjet printing method]
The ink jet textile printing method according to the present invention is mainly composed of a process in which an ink jet textile ink is ejected and adhered by an ink jet method to a fabric pretreated with the pretreatment agent of the present invention, a fixing process, and a washing process. Is done. In each step, known methods and operations can be used. Hereinafter, specific modes of each step will be exemplified.

(Pre-processing method)
As a method for attaching the pretreatment agent according to the present invention to the fabric, a coating or padding method is desirable as usual. For example, the pick-up rate at the time of padding can be appropriately determined by the thickness of the fabric, the thickness of the fiber, etc., and is preferably 50% or more, and more preferably 65% or more.

(Fabric)
The fabric that can be printed by the method of the present invention is, for example, a fabric made of synthetic fiber or a fabric made of a blend of synthetic fibers. A fabric made of polyester, acetate or a blend of these is preferable.

(Fixing)
The fabric treated with the pretreatment agent is printed with the printing ink by an ink jet method and then fixed with high heat or high heat steam. As the fixing condition, for example, in the case of a cellulosic fabric, it is preferable to treat at 95 to 105 ° C. near saturated steam for 4 to 12 minutes.

(Discharge head)
The ink-jet printing method can be applied to any ink-jet method such as a thermal method, a continuous method, or a piezo method, but is preferably a piezo vibrator method.

  When filling the inkjet ink for printing into a piezo vibrator type inkjet print head and discharging it, it is desirable that the surface layer of the nozzle plate of the print head is subjected to an ink repellent treatment. By applying the ink repellent treatment, it is difficult for the ink to be bent, and a desired image with excellent reproducibility can be printed on the fabric. This flight bending prevention effect can be remarkably improved by adding 1,2-hexanediol to the textile printing ink.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

<Examples 1-3 and Comparative Examples 1-2: Preparation of pretreatment agent>
Pretreatment agents of Examples 1 to 3 and Comparative Examples 1 and 2 having the compositions shown in Table 1 were prepared. In Table 1, the unit of numerical values is% by weight.

<Physical property evaluation>
(1) Preparation of disperse dye ink 30 parts by weight of CI disperse thread 92, 9 parts by weight of naphthalene sulfonate formalin condensate, 8 parts by weight of sodium lignin sulfonate, 53 parts by weight of water, 100 parts by volume of glass beads Used and dispersed in a sand mill for 1 day. To 60 parts by weight of this dispersion, 20 parts by weight of glycerin, 10 parts by weight of propylene glycol, 0.5 parts by weight of nonionic activator, and 9.5 parts by weight of water were added and stirred. After stirring, foreign matter was removed with a 0.45 micron filter to obtain a disperse dye ink.

(2) Inkjet printing Using the pretreatment agents prepared in Examples 1 to 3 and Comparative Examples 1 to 2, padding was carried out on a polyester fabric (pongy: width = 1 m; length = 100 m) by a conventional method. This padded polyester fabric was printed with the disperse dye ink by an inkjet printing machine (Italy Robusteli Co., Ltd .: Mona Lisa). The amount of printing dots was implemented when the main dot was 20 pL and its sub dot 5 pL, and when the main dot was 10 pL and its sub dot 3 pL or less. Fixing was performed by steaming under high humidity (160 ° C. for 8 minutes). Washing was carried out at 90 ° C. for 10 minutes with a soaping agent, sodium hydrosulfite, and sodium hydroxide solution as usual.

(3) Evaluation of flight curve A nozzle check pattern was printed with the discharge amount shown in (2) above. The printing range was 1 m × 1 m. Evaluation was made according to the following criteria, and the results are shown in Table 2.
No: No visible printing spots are observed. Slightly present: Partially visible printing spots are present. Yes: Visually visible printing spots are observed on the entire printing pattern.

(4) Electrical resistance measurement About the test piece (width = 2.5cm; length = 20cm; 12cm cloth) of the polyester cloth which padded the pretreatment agent prepared in Examples 1-3 and Comparative Examples 1-2. The electrical resistance was measured.
Specifically, in the tester industry science type friction fastness tester AB-301 used in the JIS L 0849 type II (dry) test method, PET (polyethylene) is formed on the surface of the stainless steel drum 2 as shown in FIG. (Terephthalate) film 21 was coated, and the PET film 11 was also coated on the tip of the pressure head 1. A padded polyester cloth test piece 3 is fixed on a PET film 11 provided at the tip of the pressure head 1 and charged on the drum 2 by reciprocating 100 times. Was measured. The results are shown in Table 2.

(5) Printing density The above-mentioned disperse dye is applied to the polyester fabric (pongy) pre-treated with the pre-treatment agent prepared in Examples 2 and 3 and Comparative Example 1 using an inkjet printing machine (Robsteri, Italy: Mona Lisa). Imprinted with ink. The printing pattern was solid and fine line printing. In the solid portion, the printing OD (M color) was measured. Further, the sharpness of the thin line portion was visually determined. Visual evaluation is
A: No bleeding is observed;
○: There was a portion where bleeding was slightly observed.
The results are shown in Table 3.

  INDUSTRIAL APPLICABILITY The present invention can be used when a fabric is pretreated in inkjet printing using a printing inkjet ink containing a disperse dye, and can prevent deterioration in printing quality due to ink droplet deflection in inkjet printing.

It is explanatory drawing which shows typically the mechanism of the wind pattern which generate | occur | produces in the inkjet recording method. It is explanatory drawing which shows typically the influence of the electrostatic effect which generate | occur | produces in inkjet textile printing. It is explanatory drawing which shows typically the structure of the apparatus used for an electrical resistance measurement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pressure head; 2 ... Drum; 3 ... Padding processing cotton-cloth test piece;
11, 21 ... PET film.

Claims (7)

  A pretreatment agent which is used in combination with an inkjet ink for textile printing containing a disperse dye and which contains a paste and contains an antistatic agent.   The pretreatment agent according to claim 1, wherein the inkjet ink for textile printing is an ink dispersed with an anionic dispersant, and the antistatic agent is a cationic antistatic agent.   The pretreatment agent according to claim 1 or 2, further comprising an acidifying agent and water.   The pretreatment agent according to any one of claims 1 to 3, further comprising a hydrotropic agent.   A fabric treated with the pretreatment agent according to any one of claims 1 to 4.   The fabric according to claim 5, which is polyester, acetate, or a blend thereof.   An inkjet printing method comprising a step of discharging a printing inkjet ink containing a disperse dye onto a fabric pretreated with the pretreatment agent according to any one of claims 1 to 4.

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