JP2018111761A - Inkjet printing ink and inkjet printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink comprising a vinyl sulfone type reactive dye, in which pH stability, low temperature storage stability and injection stability can be made consistent, and an inkjet printing method using the same.SOLUTION: Provided is an inkjet printing ink comprising: a vinyl sulfone type reactive dye; and water. The vinyl sulfone type reactive dye includes: a compound having a sulfoxy ethyl sulfonyl group(s); and a compound having a vinyl sulfone group(s), and also satisfying equation (1): in the equation (1):0.20≤[VS group]/[VS group+SES group]≤0.95(in the equation (1), [VS group] denotes the content (mol) of the vinyl sulfone group(s) in the ink; and [VS group+SES group] denotes the total content (mol) of the vinyl sulfone group(s) and the sulfoxy ethyl sulfonyl groups.SELECTED DRAWING: None

Description

  The present invention relates to an inkjet printing ink and an inkjet printing method.

  Conventionally, screen printing or roller printing using a plate has been performed as a printing method. However, in these printings, since it is necessary to prepare a plate prior to dyeing, the production efficiency is low. In recent years, since it is not necessary to produce a plate and the production efficiency is high, so-called ink jet textile printing, in which an image is formed on a recording medium such as a fabric by an ink jet method, has been performed.

  In inkjet printing, fine ink droplets are ejected from an inkjet recording head and landed on a recording medium such as a cloth to form an image. Examples of the color material contained in the ink used in ink jet textile printing include acid dyes, disperse dyes, and reactive dyes. A reactive dye may be used for forming an image on a fabric mainly composed of cellulose.

  As reactive dyes, vinyl sulfone type reactive dyes and monochlorotriazine type reactive dyes are known. However, inks containing these reactive dyes have a problem in that long-term storage stability is low because they tend to cause fluctuations in pH and viscosity under the influence of temperature changes and additives under long-term storage.

  As a method for improving the long-term storage stability of an ink containing a reactive dye, a method of adding urea to the ink is known. For example, Patent Document 1 discloses an inkjet ink for textile printing containing a monochlorotriazine type reactive dye, urea, 2-imidazolidinone, and an organic buffer. Patent Document 2 discloses a printing paste containing an aqueous reactive dye composition (P) containing a reactive dye, urea (biuret), and a formulation additive such as a solubilizer, a thickener, and a pH adjuster. Is disclosed.

JP 2010-116566 A Japanese translation of PCT publication No. 2002-521549

By the way, it is known that a vinyl sulfone type reactive dye causes a reaction represented by the following formula (A) in the presence of an alkali.
_{D-SO 2 -CH 2 CH 2} -O-SO 3 M (SES body)
_{→ D-SO 2 CH = CH} 2 (VS _{body) + HO-SO 3 M ···} (A)

  Since a compound having a sulfoxyethylsulfonyl group (SES form) has high solubility in water or a water-soluble organic solvent, an ink containing the compound has little dye crystallization under low-temperature storage and also has injection stability. It is good. However, since a compound having a sulfoxyethylsulfonyl group (SES form) generates an acid by causing a reaction represented by the above formula (A) in the presence of an alkali, the pH of the ink is easily lowered rapidly.

  On the other hand, a compound having a vinyl sulfone group (VS form) does not cause an acid-generating reaction, but has low solubility in water or a water-soluble organic solvent. There was a problem that precipitation was likely to occur and injection stability was low.

  Therefore, an ink containing a vinyl sulfone-type reactive dye is required to be highly compatible with pH stability, low-temperature storage stability and ejection stability.

  Since Patent Document 1 mainly relates to an ink containing a monochlorotriazine type reactive dye, the pH stability peculiar to an ink containing a vinyl sulfone type reactive dye, low-temperature storage stability and ejection stability are compatible. No issues are suggested. Patent Document 2 mainly includes a compound having a sulfoxyethylsulfonyl group as a vinylsulfone reactive dye, and adjusting the content ratio of the compound having a sulfoxyethylsulfonyl group and the compound having a vinylsulfone group. Is not suggested.

  The present invention has been made in view of the above circumstances, and is an ink containing a vinyl sulfone-type reactive dye, and an inkjet printing ink that can achieve both pH stability, low-temperature storage stability and ejection stability, and It is an object of the present invention to provide an ink jet textile printing method used.

[1] A vinyl sulfone type reactive dye, a water-soluble organic solvent, and water, wherein the vinyl sulfone type reactive dye includes a compound having a sulfoxyethylsulfonyl group and a compound having a vinyl sulfone group, and An inkjet textile printing ink that satisfies the following formula (1).
Formula (1): 0.20 ≦ [VS group] / [VS group + SES group] ≦ 0.95
(In the formula (1),
[VS group]: content (mol) of vinyl sulfone group in the ink,
[VS group + SES group]: Total content of vinylsulfone group and sulfoxyethylsulfonyl group in ink (mol))
[2] The inkjet textile printing ink according to [1], which satisfies the following formula (2).
Formula (2): 0.40 ≦ [VS group] / [VS group + SES group] ≦ 0.9
[3] The inkjet textile printing ink according to [1] or [2], which satisfies the following formula (3).
Formula (3): 0.60 ≦ [VS group] / [VS group + SES group] ≦ 0.8
[4] The inkjet textile printing ink according to any one of [1] to [3], wherein the content of the vinyl sulfone reactive dye is 15 to 30% by mass with respect to the total mass of the ink.
[5] The water-soluble organic solvent includes any one of [1] to [4], including at least one selected from the group consisting of 2-pyrrolidone, ε-caprolactam, 2,2-thiodiethanol, and ethylene urea. The inkjet textile printing ink as described in 2.
[6] A step of ejecting droplets of the ink-jet printing ink according to any one of [1] to [5] from a recording head to form an image on a fabric provided with a hydrophilic resin having a hydroxy group; And a step of fixing the image by heating the fabric on which the image is formed.
[7] The inkjet printing method according to [6], wherein the fabric includes cellulose fiber or protein fiber.

  According to the present invention, it is an ink containing a vinyl sulfone type reactive dye, and provides an ink jet printing ink that can achieve both pH stability, low temperature storage stability and ejection stability, and an ink jet printing method using the same. Can do.

It is the partial schematic which shows an example of a structure of an inkjet textile printing apparatus.

The inventors set the content of the vinyl sulfone group contained in the ink to [VS group] (unit: mol), and the total content of the sulfoxyethylsulfonyl group and the vinyl group contained in the ink to [VS group + SES group]. When (unit: mol), it was found that by adjusting the ink so as to satisfy the following formula (1), both pH stability, injection stability and low-temperature storage stability can be achieved.
Formula (1): 0.20 ≦ [VS group] / [VS group + SES group] ≦ 0.95

  [VS group] / [VS group + SES group] can be adjusted by, for example, the content ratio of the compound having a sulfoxyethylsulfonyl group and the compound having a vinylsulfone group. In other words, by containing a compound having a sulfoxyethylsulfonyl group that can improve the low-temperature storage stability and ejection stability of the ink and a compound having a vinylsulfone group that can improve the pH stability of the ink in an appropriate ratio. It is considered that the pH stability, low-temperature storage stability, and ejection stability of the ink can be improved in a well-balanced manner. The present invention has been made based on such knowledge.

1. Inkjet Textile Ink The inkjet textile ink of the present invention contains a vinyl sulfone reactive dye and water. The inkjet textile printing ink of the present invention may further contain a water-soluble organic solvent, other additives, and the like as necessary.

(Vinyl sulfone type reactive dye)
The vinyl sulfone type reactive dye comprises a compound having a sulfoxyethylsulfonyl group (—SO ₂ —CH ₂ CH ₂ —O—SO ₃ M) and a compound having a vinyl sulfone group (—SO ₂ CH═CH ₂ ). Including.

  A compound having a sulfoxyethylsulfonyl group is a compound having a functional group that reacts with one or more fabrics, and at least one of which is a sulfoxyethylsulfonyl group. Of the functional groups that react with two or more fabrics of a compound having a sulfoxyethylsulfonyl group, one or more functional groups may be sulfoxyethylsulfonyl groups, and the rest are vinylsulfone groups, monochlorotriazine groups, etc. Also good.

  The compound having a vinyl sulfone group is a compound having a functional group that reacts with one or more fabrics, and one or more of them are vinyl sulfone groups. Of the functional groups that react with two or more fabrics of the compound having a vinyl sulfone group, one or more functional groups may be vinyl sulfone groups, and the rest may be sulfoxyethylsulfonyl groups, monochlorotriazine groups, or the like. .

  The total number of functional groups that react with the fabric contained in one molecule of the compound having a sulfoxyethylsulfonyl group and the compound having a vinylsulfone group may be the same or different.

  The dye matrix of the compound having a sulfoxyethylsulfonyl group and the compound having a vinylsulfone group may be the same or different.

  The vinyl group of the compound having a vinyl sulfone group and the vinyl group produced by decomposing the sulfoxyethylsulfonyl group of the compound having a sulfoxyethylsulfonyl group on the fabric are formed on the fabric provided with the pretreatment agent. Nucleophilic addition reaction to a hydroxyl group reacts with the fabric.

  When the compound having a sulfoxyethylsulfonyl group or the compound having a vinylsulfone group further has a monochlorotriazine group, the reaction between the reactive dye and the fabric causes not only the above nucleophilic addition reaction but also a nucleophilic substitution reaction. sell. This is caused by a nucleophilic substitution reaction of the chloro group of the monochlorotriazine group to the hydroxyl group of the fabric.

  As described above, a compound having a sulfoxyethylsulfonyl group has high solubility in water or a water-soluble organic solvent, and thus can improve the low-temperature storage stability and ejection stability of the ink. Since the reaction (A) proceeds, the pH of the ink is easily lowered rapidly. On the other hand, although a compound having a vinyl sulfone group does not cause such a reaction, it has a low solubility in water or a water-soluble organic solvent, and thus tends to lower the low-temperature storage stability and ejection stability of the ink.

In contrast, the ink-jet textile printing ink of the present invention has a content of vinyl sulfone group contained in the ink as [VS group], and a total content of vinyl group and sulfoxyethylsulfonyl group contained in the ink as [VS group + SES. When [group], it is adjusted to satisfy the following formula (1).
Formula (1): 0.20 ≦ [VS group] / [VS group + SES group] ≦ 0.95

  When [VS group] / [VS group + SES group] is 0.2 or more, the pH stability of the ink is easily improved, and when it is 0.95 or less, the low-temperature storage stability and the ejection stability of the ink are easily improved. . That is, by setting [VS group] / [VS group + SES group] in the above range, both pH stability, low-temperature storage stability, and injection stability can be achieved. The inkjet textile printing ink of the present invention more preferably satisfies the formula (2): 0.40 ≦ [VS group] / [VS group + SES group] ≦ 0.9, and the formula (3): 0.60 ≦ [VS. More preferably, the group] / [VS group + SES group] ≦ 0.8 is satisfied.

The [VS group] / [VS group + SES group] of the ink can be easily known by quantifying by liquid chromatography (HPLC) with reference to a dye having a sulfonylethylsulfonyl group and a dye having a vinylsulfone group. . A peak derived from a dye having a sulfoxyethylsulfonyl group and a peak derived from a dye having a vinylsulfone group are discriminated from the peak time of HPLC, and the content of vinylsulfone groups in the ink from the area of each peak [ [VS group] (unit: mol) and the content [SES group] (unit: mol) of the sulfoxyethylsulfonyl group are determined.
2) Let the sum of the obtained [VS group] and [SES group] be [VS group + SES group].
3) Divide [VS group] obtained in 1) above by [VS group + SES group] obtained in 2) to calculate [VS group] / [VS group + SES group].

[VS group] / [VS group + SES group] can be adjusted by, for example, the content ratio of the compound having a sulfoxyethylsulfonyl group and the compound having a vinylsulfone group in the ink.
The content ratio may be adjusted according to the blending ratio of 1) individually prepared compound having a sulfoxyethylsulfonyl group and a compound having a vinylsulfone group, as described later; and 2) a sulfoxyethylsulfonyl group. You may adjust by using the dye composition which replaced a part of compound which has this by the compound shown by the formula (A) mentioned later by the compound which has a vinyl sulfone group.

  Examples of the compound having a sulfoxyethylsulfonyl group include C.I. I. Reactive Yellow 15, C.I. I. Reactive Yellow 37, C.I. I. Reactive yellow 42; I. Reactive Orange 16, C.I. I. Reactive Orange 78, C.I. I. Reactive Orange 107; C.I. I. Reactive Red 23, C.I. I. Reactive Red 35, C.I. I. Reactive Red 106, C.I. I. Reactive Red 180; C.I. I. Reactive Violet 5, C.I. I. Reactive Blue 19, C.I. I. Reactive Blue 21, C.I. I. Reactive Blue 38, C.I. I. Reactive blue 229; I. Reactive brown 18; C.I. I. Reactive Black 5, C.I. I. Reactive Black 14, C.I. I. Reactive black 31 and the like are included. Among these, C.I. I. Reactive black 5 is preferred.

  Examples of the compound having a vinylsulfone group include compounds exemplified by the compound having a sulfoxyethylsulfonyl group in which a part or all of the sulfoxyethylsulfonyl group is replaced with a vinylsulfone group.

Such a compound can be obtained, for example, by reacting an alkali component (base component) with the following formula (A) in an aqueous solution containing a compound having a sulfoxyethylsulfonyl group. The reaction conditions can be the same as those described later.
_{D-SO 2 -CH 2 CH 2} -O-SO 3 M
_{→ D-SO 2 CH = CH} 2 + HO-SO 3 M ··· (A)
[D represents a pigment matrix;
M represents a monovalent metal cation (preferably Na ion)]

  One type of the dye base (D in the formula (A)) of the vinyl sulfone type reactive dye contained in the inkjet textile printing ink of the present invention may be used, or two or more types may be combined.

  The content of the vinyl sulfone reactive dye is preferably 15 to 30% by mass with respect to the total mass of the ink. When the content of the vinyl sulfone reactive dye is 15% by mass or more with respect to the total mass of the ink, the concentration of the ink is easily increased, and when it is 30% by mass or less, the ink is difficult to thicken. Is hard to be damaged. The content of the vinyl sulfone reactive dye is more preferably 20 to 30% by mass with respect to the total mass of the ink.

(Water-soluble organic solvent)
The water-soluble organic solvent is not particularly limited as long as it can dissolve the reactive dye.
Examples of water-soluble organic solvents include
Alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, t-butanol);
Polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, 2, 2 -Thiodiethanol);
Amines (e.g., ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyl Diethylenetriamine, tetramethylpropylenediamine);
Amides (eg, N, N-dimethylformamide, N, N-dimethylacetamide, etc.);
Heterocycles (eg, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, ethylene urea, etc.);
Sulfoxides (for example, dimethyl sulfoxide) and the like are included.

  Among these, the water-soluble organic solvent preferably contains at least one selected from the group consisting of 2-pyrrolidone, ε-caprolactam, 2,2-thiodiethanol, and ethylene urea. This is because these solvents have a function of making it difficult for the water in the ink to volatilize on the nozzle surface and further improving the ejection stability of the ink. As a result, the inkjet printing ink of the present invention is less likely to impair the ejection stability even if it contains a higher concentration of vinyl sulfone groups than inks containing conventional vinyl sulfone reactive dyes.

  The total content of at least one selected from the group consisting of 2-pyrrolidone, ε-caprolactam, 2,2-thiodiethanol, and ethylene urea is preferably 3 to 20% by mass with respect to the total mass of the ink. . When the content of these solvents is 3% by mass or more, it is easy to improve the ejection stability of the ink. When the content is 20% by mass or less, erosion and swelling of members inside the print head are difficult to occur and durability is impaired. It's hard to get it. The content of these solvents is more preferably 5 to 15% by mass with respect to the total mass of the ink.

(Other additives)
The inkjet textile printing ink of the present invention may further contain other additives such as a pH adjuster, a surfactant, a preservative, and an antifungal agent.

[PH adjuster]
Examples of the pH adjusting agent include urea, sodium hydroxide and the like. Among these, urea is preferable because it has alkali release properties and is used in combination with a reactive dye having acid release properties, so that the pH of the ink can be easily maintained within a predetermined range.

  The content of the pH adjusting agent is preferably 1 to 10% by mass with respect to the total mass of the ink. When the content of the pH adjusting agent is 1% by mass or more, the pH of the ink is easily stabilized, and when it is 10% by mass or less, for example, when urea is used, it is caused by decomposition of urea under long-term storage. Since the ink does not thicken easily, long-term storage stability is not easily lost. The content of the pH adjusting agent is more preferably 2 to 5% by mass with respect to the total mass of the ink.

[Surfactant]
Examples of surfactants include dialkyl sulfosuccinates, alkyl naphthalene sulfonates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene block copolymers, alkyl Amine salts, quaternary ammonium salts, silicon surfactants, fluorine surfactants and the like are included. Among these, acetylene glycol surfactants have relatively low foaming properties and can adjust the surface tension of the ink. For this reason, the ink ejectability from the ink jet recording head is enhanced.

[Preservatives, antifungal agents]
Examples of antiseptics and antifungal agents include aromatic halogen compounds (for example, Preventol CMK), methylene dithiocyanate, halogen-containing nitrogen sulfur compounds, 1,2-benzisothiazolin-3-one (for example, PROXEL GXL), etc. Is included. Preservatives and antifungal agents increase the storage stability of the ink.

(Ink physical properties)
The pH of the inkjet textile printing ink of the present invention preferably satisfies the range of 3.0 to 6.0. When the pH is within the above range, not only the above-described vinyl sulfone reactive dye is likely to exist stably, but also corrosion of the nozzle can be suppressed. The pH of the ink can be measured at 25 ° C. using a HM-20S type manufactured by Toa DKK Corporation.

  The ink jet textile ink of the present invention preferably has an ink viscosity at 25 ° C. of 1 to 100 mPa · s, more preferably 1 to 40 mPa · s, from the viewpoint of ejection properties from the ink jet recording head. More preferably, it is 40 mPa * s, and it is especially preferable that it is 5-20 mPa * s. The viscosity of the ink can be measured with a cone plate viscometer, for example, a TVE-33LT viscometer manufactured by Toki Sangyo Co., Ltd.

  The surface tension of the ink at 25 ° C. is preferably 30 to 60 mN / m. If the surface tension of the ink is 30 mN / m or more, the wettability of the ink with respect to the fabric does not become too high, and it is easy to suppress bleeding of the image. On the other hand, when the surface tension is 60 mN / m or less, the wettability of the ink with respect to the fabric is not too low, so that the ink penetration force is not easily impaired.

(Preparation of ink)
In the inkjet textile printing ink of the present invention, the above-described vinyl sulfone reactive dye, water, and other components as necessary are mixed so that [VS group] / [VS group + SES group] satisfies the above range. It is manufactured through steps.

  Specifically, 1) a compound having a sulfoxyethylsulfonyl group and a compound having a vinylsulfone group are separately prepared, and the blending ratio thereof is adjusted to obtain [VS group] / [VS group]. + SES group] may satisfy the above range; or 2) a dye in which a part of the compound having a sulfoxyethylsulfonyl group is replaced with a compound having a vinylsulfone group by the reaction of the above formula (A) Using the composition, an ink may be obtained in which [VS group] / [VS group + SES group] satisfies the above range.

  In the case of 2), the reaction of the above-mentioned formula (A) is caused by heating after adding an alkaline component to an aqueous solution containing a compound having a sulfoxyethylsulfonyl group.

  Examples of the alkali component to be added include sodium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate and the like, preferably sodium hydroxide. The addition amount of the alkali component is preferably 0.25 to 1.1 mol with respect to 1 mol of the compound having a sulfoxyethylsulfonyl group.

  The reaction temperature is preferably 50 ° C. or lower. When the reaction temperature is 50 ° C. or lower, hydrolysis of the produced compound having a vinyl sulfone group is highly easily suppressed. The reaction temperature is more preferably 30 to 40 ° C. Although reaction time is based also on reaction temperature, it is preferable that it is 1-48 hours, for example.

  The obtained dye composition is purified by, for example, filtration to remove excess alkali components. Thereafter, the obtained dye composition, water, and other components as necessary are mixed to obtain the ink-jet printing ink of the present invention.

2. Inkjet Textile Printing Method The inkjet textile printing method using the inkjet textile printing ink of the present invention forms an image on a fabric provided with a hydrophilic resin having a hydroxy group by discharging droplets of the inkjet textile printing ink of the present invention from a recording head. And a step of heating the fabric on which the image is formed to fix the image on the fabric. A fabric provided with a hydrophilic resin having a hydroxy group can be obtained by applying a pretreatment agent containing a hydrophilic resin having a hydroxy group to the fabric.

  That is, the inkjet printing method of the present invention includes (1) a step of applying a pretreatment agent containing a hydrophilic resin having a hydroxy group (pretreatment step) and (2) a fabric provided with the pretreatment agent. A step of forming an image by ejecting droplets of textile printing ink (ink applying step), and (3) a step of heating the fabric on which the image is formed and fixing the image on the fabric (coloring step). If necessary, (4) a step of drying the fabric after application of ink (preliminary drying step), (5) a step of removing dyes and pretreatment agents that could not be dyed on the fabric (washing step), ( 6) A step of drying the washed fabric (drying step) may be further included.

(Pretreatment process)
The pretreatment step is a step of applying a pretreatment agent to the fabric. Examples of the method for applying the pretreatment agent to the fabric include a pad method, a coating method, a spray method, and an ink jet method. By these methods, the pretreatment agent can be applied onto the fabric. Examples of fabrics to which a pretreatment agent has been added include fabrics having an ink receiving layer described in JP-A No. 62-53492, and anti-reduction agents and alkaline agents described in JP-B-3-46589. Included fabrics and the like are included.

  From the viewpoint of obtaining a uniform image, before applying the pretreatment agent to the fabric, natural impurities (oils, waxes, pectic substances, natural pigments, etc.) adhering to the fabric fibers, and residues of the chemicals used in the fabric manufacturing process ( It is preferable to clean the adhesive or the like) or the dirt attached to the fabric. The cleaning agent for cleaning the fabric includes an alkali agent such as sodium hydroxide or sodium carbonate, an anionic or nonionic surfactant, or an enzyme.

  The pretreatment agent preferably contains at least a resin component, an alkali agent, and a hydrotropic agent, and may further contain additives such as a reduction inhibitor, a preservative, or a chelating agent.

  The resin component preferably contains a hydrophilic resin having a hydroxy group. Examples of hydrophilic resins having a hydroxy group include natural gums such as guar and locust bean, starches, seaweeds such as sodium alginate and funari, plant skins such as pectic acid, methyl fibrin, ethyl fibrin, hydroxy Fibrin derivatives such as ethyl cellulose and carboxymethyl cellulose, processed starches such as roasted starch, alpha starch, carboxymethyl starch, carboxyethyl starch and hydroxyethyl starch, processed natural gums such as shiraz gum and roast bean gum, algin derivatives and poly Synthetic pastes such as vinyl alcohol and polyacrylic acid esters, and emulsions are included.

  Examples of alkaline agents include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, amines such as mono, di, and triethanolamine, and carbonates such as sodium carbonate, potassium carbonate, and sodium bicarbonate (sodium bicarbonate). Alternatively, alkali metal bicarbonates, organic acid metal salts such as calcium acetate and barium acetate, ammonia and ammonia compounds, sodium trichloroacetate which becomes an alkali agent under steaming or dry heat, and the like are included. Among these, sodium carbonate and sodium hydrogen carbonate are preferable. The amount of the alkaline agent applied is preferably 0.1 to 10% by mass and more preferably 0.5 to 5% by mass with respect to the total mass of the fabric. The presence of an appropriate alkaline agent in the fabric allows the printing ink containing the reactive dye to be reliably dyed. Therefore, it is preferable that the fabric contains an alkali agent in advance.

  Examples of the hydrotropic agent include urea, ethyleneurea, dimethylurea, thiourea, monomethylthiourea, alkylurea such as dimethylthiourea, and the like. This is because the image density is improved by the addition of the hydrotropic agent.

  The application amount (squeezing ratio) of the pretreatment agent or the amount of the resin component contained in the pretreatment agent is appropriately set according to the type of fabric and its use.

  The pretreatment agent may further contain a reduction inhibitor, a preservative, or a chelating agent as necessary. The reduction inhibitor may be sodium m-nitrobenzenesulfonate or the like. The preservative may be the preservative exemplified as the preservative for printing ink, or may be the same. The chelating agent may be ethylenediaminetetraacetate, nitrilotriacetate, hexametaphosphate, pyrophosphate, or metaphosphate.

  The pretreatment agent applied to the fabric can be heat-dried using hot air, a hot plate, a heat roller, or the like.

  The fiber material constituting the fabric is not particularly limited as long as a hydrophilic resin having a hydroxy group is provided (as a pretreatment agent), but in terms of enhancing dyeability, a fiber that can be dyed with a reactive dye; It is preferable to include a fiber having a hydroxy group. Examples of the fiber having a hydroxy group include cellulose fibers such as cotton and protein fibers such as silk. The fabric may be any form of these fibers such as a woven fabric, a nonwoven fabric, and a knitted fabric. The fabric that can be used in the present invention may be composed only of fibers that can be dyed with reactive dyes, but may be a blended woven fabric or a blended nonwoven fabric with rayon, polyurethane, polyester, acrylic, or the like. . Moreover, it is preferable that the thickness of the fiber which comprises a fabric exists in the range of 10-100d.

(Ink application process)
The ink application step is a step of forming a pre-colored image by discharging ink-jet textile ink droplets from the ink-jet recording head toward the fabric. While moving the cloth relative to a head carriage on which a plurality of ink jet recording heads are mounted, droplets of the ink jet printing ink set are discharged and landed on the cloth. The surface temperature of the fabric when the ink droplets land is not particularly limited, but it is preferably heated in the range of 35 to 70 ° C. from the viewpoint of suppressing bleeding of the pre-colored image. Note that it is preferable to keep the ink temperature at 25 ° C. from the viewpoint of suppressing fluctuations in ink viscosity due to fluctuations in ink temperature.

(Preliminary drying process)
The preliminary drying step is a step of drying the fabric after ink application. Although not particularly limited, the preliminary drying is preferably performed by drying the fabric at 150 ° C. or lower for 0.5 to 30 minutes. Examples of the drying method include an air convection method, a heating roll direct attachment method, and an irradiation method. Specifically, ink may be applied to the fabric, and the fabric may be dried under the above conditions and method before the fabric is wound.

(Coloring process)
The color development step refers to heating the fabric after ink application (after predrying when it includes a predrying step) to dye reactive dyes that are not sufficiently dyed into the fabric, This is a step of developing a hue.

  Although the color development temperature (heating temperature) depends on the color development method (heating method), it is preferably 95 ° C. or higher and lower than 220 ° C., and 95 ° C. or higher and 190 ° C. or higher from the viewpoint of strengthening the dyeing of the reactive dye onto the fabric. More preferably, it is 100 degrees C or less, and it is still more preferable that it is 100 degreeC or more and 180 degrees C or less.

  The color development method (heating method) may be a conventionally known method, and is appropriately selected depending on textile printing ink, fabric, or the like. For example, steaming; baking with dry heat; thermosol; HT steamer with superheated steam. Among these, a method (steaming method) and a dry heat method (baking method) in which reactive dyes in the ink are fixed by high-heat steam are preferable.

  In the steaming method using high-temperature steam, if the heating temperature is too low, a large amount of liquid water exists, so reactive dyes contained in dark ink and light color ink are likely to hydrogen bond with liquid water in addition to fabrics. For this reason, it may be easily washed away with water and may not be sufficiently dyed. Therefore, from the viewpoint of strengthening the dyeing of the reactive dye onto the fabric, the heating temperature is preferably 95 ° C. or higher, and more preferably 100 ° C. or higher. For example, cellulosic fibers are preferably treated at 95-105 ° C. for 5-15 minutes; amide fibers such as silk and wool are preferably treated at 95-105 ° C. for 20-40 minutes. . In addition, the fabric to which the ink has been applied may be colored immediately or after a lapse of time.

  In the baking method by dry heat, from the viewpoint of easily obtaining sufficient dyeability and easily suppressing the decomposition of the dye, the heating temperature is preferably 150 ° C. or higher and lower than 220 ° C., 150 ° C. or higher and 190 ° C. Or less, more preferably 150 ° C. or more and 180 ° C. or less.

(Washing process)
The washing step is a step of removing reactive dyes and pretreatment agents that could not be dyed on the fabric after the color development step of the fabric. The removal of reactive dyes that could not be dyed on the fabric can be performed by a conventionally known cleaning method, and is appropriately selected depending on the printing ink, the fabric, or the like. For example, the cellulose fiber is generally washed with hot water and water after being treated with a soaping bath containing a nonionic detergent after washing with water and hot water. By removing the undyed reactive dye, the fastness to washing, the fastness to water, the fastness to sweat, and the like tend to be improved. If there is a reactive dye that could not be dyed on the fabric, it is difficult to obtain fastness to washing, fastness to water, fastness to sweat, and the like.

(Drying process)
A drying process is a process performed after the said washing | cleaning process and drying the wash | cleaned fabric. The drying method is not particularly limited, and may be a method of squeezing the washed fabric, drying it, or drying it using a dryer (heat roll, iron, etc.).

(Inkjet printing device)
Hereinafter, an apparatus for performing the ink application process and the preliminary drying process will be described with reference to the drawings. However, the inkjet printing apparatus is not limited thereto.

  FIG. 1 is a partial schematic diagram illustrating an example of the configuration of an inkjet textile printing apparatus. The ink jet textile printing apparatus includes a transport means 2 for transporting the cloth P, a head carriage 5 on which a plurality of ink jet recording heads (not shown) for ejecting ink jet textile ink droplets are mounted on the cloth P, and warm air on the cloth P. And hot air applying means 6 for applying.

  The transport unit 2 includes an adhesive belt 21, a support roller 22, a transport roller 23, and a nip roller 24. The adhesive belt 21 is held by the support roller 22 and the conveyance roller 23 and circulates between the support roller 22 and the conveyance roller 23. The nip roller 24 is disposed to face the conveying roller 23 with the adhesive belt 21 interposed therebetween.

  The warm air applying means 6 and the head carriage 5 are disposed above the fabric P. The warm air applying means 6 includes a fan 6A that blows wind on the fabric and a heating element 6B that can control the temperature. On the other hand, the head carriage 5 includes an ink jet recording head. The type of the ink jet recording head is not particularly limited, and may be either a thermal type or a piezo type. The nozzle diameter of the ink jet recording head is preferably 10 to 100 μm, and more preferably 10 to 50 μm. This is because if the nozzle diameter is 10 μm or more, nozzle clogging due to insoluble matter is unlikely to occur, and if it is 100 μm or less, the sharpness of the formed image is difficult to be lowered. Further, the droplet size of the ink to be ejected is preferably 4 to 150 pl, and more preferably 5 to 80 pl. This is because when the ink droplet size is 4 pl or more, the ejected ink droplets are not easily affected by the air flow in the vicinity of the head, and when the ink droplet size is 150 pl or less, the granularity of the formed image is not noticeable.

  When the transport roller 23 is driven, the fabric P disposed on the upper surface of the adhesive belt 21 is transported to the lower surface of the nip roller 24. The fabric P is pressed by the adhesive belt 21 and the nip roller 24 and fixed to the adhesive belt 21. The fabric P fixed to the adhesive belt 21 is conveyed below the head carriage 5. A plurality of ink jet recording heads mounted on the head carriage 5 ejects ink jet printing ink droplets, land on a predetermined region (landing possible region) of the fabric to which the pretreatment agent is applied, and form an image. Next, the temperature-controlled wind or warm air is blown from the warm air applying means 6 to dry the image formed on the fabric P.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

1. Ink materials (1) Preparation of vinylsulfone reactive dye (Preparation of dye 1-1)
C. I. Reactive Black 5 was prepared as Dye 1-1 (a compound having a sulfoxyethylsulfonyl group). The dye 1-1 contains a compound having the following structure as a main component.

(Preparation of dye 1-2)
C. I. Reactive Black 5 is 30.0 parts by mass (sulfoxyethylsulfonyl group is 0.6 mol / L), NaOH is 0.6 parts by mass (0.15 mol / L), and water is 68.8 parts by mass. Mixed. The resulting solution was left at 40 ° C. for 24 hours. Thereafter, the solid obtained by filtering the generated precipitate was purified and dried to obtain Dye 1-2 (a compound having a sulfoxyethylsulfonyl group or a compound having a vinylsulfone group). The dye 1-2 contains a compound having the following structure as a main component.

(Preparation of dye 1-3)
C. I. Reactive Black 5 is 30.0 parts by mass (sulfoxyethylsulfonyl group is 0.6 mol / L), NaOH is 2.8 parts by mass (0.7 mol / L), and water is 67.6 parts by mass. Mixed. The resulting solution was left at 40 ° C. for 24 hours. Thereafter, a solid obtained by filtering the generated precipitate was purified and dried to obtain Dye 1-3 (compound having a vinyl sulfone group). The dye 1-3 contains a compound having the following structure as a main component.

(Preparation of dye 2-1)
C. I. Reactive Yellow 15 was prepared as a dye 2-1 (a compound having a sulfoxyethylsulfonyl group). The dye 2-1 contains a compound having the following structure as a main component.

(Preparation of dye 2-2)
C. I. Reactive Yellow 15 30.0 parts by mass (sulfoxyethylsulfonyl group 0.5 mol / L), NaOH 2.0 parts by mass (0.5 mol / L), water 68.0 parts by mass Mixed. The resulting solution was left at 40 ° C. for 24 hours. Thereafter, a solid obtained by filtering the generated precipitate was purified and dried to obtain Dye 2-2 (compound having a vinyl sulfone group). The dye 2-2 contains a compound having the following structure as a main component.

(Preparation of dye 3-1)
C. I. Reactive orange 78 was prepared as dye 3-1 (a compound having a sulfoxyethylsulfonyl group). The dye 3-1 contains a compound having the following structure as a main component.

(Preparation of dye 3-2)
C. I. Reactive Orange 78 is 30.0 parts by mass (sulfoxyethylsulfonyl group is 0.5 mol / L), NaOH is 2.0 parts by mass (0.5 mol / L), and water is 68.0 parts by mass. Mixed. The resulting solution was left at 40 ° C. for 24 hours. Thereafter, the solid obtained by filtering the generated precipitate was purified and dried to obtain Dye 3-2 (compound having a vinyl sulfone group). The dye 3-2 contains a compound having the following structure as a main component.

(Preparation of dye 4-1)
C. I. Reactive Orange 16 was prepared as a dye 4-1 (a compound having a sulfoxyethylsulfonyl group). The dye 4-1 contains a compound having the following structure as a main component.

(Preparation of dye 4-2)
C. I. Reactive Orange 16 is 30.0 parts by mass (sulfoxyethylsulfonyl group is 0.5 mol / L), KOH is 2.9 parts by mass (0.5 mol / L), and water is 68.0 parts by mass. Mixed. The resulting solution was left at 40 ° C. for 24 hours. Thereafter, the solid obtained by filtering the generated precipitate was purified and dried to obtain Dye 4-2 (compound having a vinyl sulfone group). The dye 4-2 contains a compound having the following structure as a main component.

(2) Urea compounds Urea

(3) Water-soluble organic solvent Glycerin (Gly)
Ethylene glycol (EG)
Propylene glycol (PG)

(4) Other components Surfactant (E1010 manufactured by Nissin Chemical Industry Co., Ltd.)
Antifungal agent (Lonza Japan Proxel GXL (S))

2. Ink Preparation and Evaluation (Example 1)
As a vinyl sulfone type reactive dye, 20 parts by mass of the dye 1-1 prepared above, 5.0 parts by mass of the dye 1-3; 10 parts by mass of urea as a urea compound; 5 parts by mass of glycerin as a water-soluble organic solvent; 20 parts by mass of ethylene glycol and 10 parts by mass of propylene glycol; 0.1 parts by mass of E1010 manufactured by Nissin Chemical Industry Co., Ltd. as a surfactant; 0.1 parts by mass of Proxel GXL (S) as an antifungal agent were mixed. Ion exchanged water was added to the resulting mixture so that the total amount was 100 parts by mass to prepare an ink.

(Examples 2-27, Comparative Examples 1-6)
Inks were prepared in the same manner as in Example 1 except that the ink composition was changed as shown in Tables 1 to 4.

  [VS group] / [VS group + SES group], storage stability (pH stability) and low-temperature storage stability of the obtained ink were evaluated by the following methods, respectively.

([VS group] / [VS group + SES group])
1) A liquid obtained by diluting the obtained ink 1000 times with pure water was used as a sample liquid. About this sample liquid, the liquid chromatography (HPLC) measurement was performed on condition of the following.
(Measurement conditions for liquid chromatography)
Apparatus: High-performance liquid chromatograph L-2000 series manufactured by Hitachi High-Tech Science Co., Ltd. Column: Inertsil ODS-SP (manufactured by GL Sciences, inner diameter: 4 mm, length: 250 mm, particle diameter: 5 μm)
Mobile phase (eluent): Water: acetonitrile = 90: 10 (volume ratio) to 50:50 Gradient Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: Diode array detector, Measurement wavelength: 254 nm
A peak derived from a dye having a vinyl sulfone group and a peak derived from a dye having a sulfoxyethylsulfonyl group in HPLC are identified, and the content of vinyl sulfone groups in the ink [VS group] (unit: mol) and the sulfoxyethylsulfonyl group content [SES group] (unit: mol).
2) The sum of the obtained [VS group] and [SES group] was defined as [VS group + SES group].
3) [VS group] / [VS group + SES group] obtained by dividing [VS group] obtained in 1) above by [VS group + SES group] obtained in 2) above.

(Storage stability (pH stability))
The pH of the obtained ink at 25 ° C. was measured using HM-20S type manufactured by Toa DKK Corporation. After the ink was stored at 25 ° C. for 4 weeks, the pH of the ink was measured in the same manner. The ink pH change ΔpH before and after storage (= ink pH before storage−ink pH after storage) was calculated and evaluated based on the following criteria.
A: ΔpH is ± 0.1 or less ○: ΔpH is more than ± 0.1 ± 0.3 or less Δ: ΔpH is more than ± 0.3 ± 0.4 or less Δ ×: ΔpH is more than ± 0.4 ± 0. 5 or less x: ΔpH is more than ± 0.5 If the pH stability of the ink was Δ or more, it was judged to be good and practically satisfactory.

(Low temperature storage stability)
After the obtained ink was stored at −10 ° C. for 2 weeks, the presence or absence of crystal precipitation was visually observed, and the filtration pressure when passing through a cellulose acetate filter having an opening of 0.45 μm was confirmed. And it evaluated based on the following references | standards.
◎: No precipitation, no increase in filtration pressure compared to before storage △: No precipitation, but an increase in filtration pressure compared to before storage ×: There is precipitation, and the filtration pressure is higher than before storage There is also a rise

  Furthermore, using the obtained ink, an image was formed by the inkjet printing method according to the following procedure.

<Inkjet printing method>
(Pretreatment process)
A 100% cotton fabric (with cotton broad sill, manufactured by Color & Color Co., Ltd.) was prepared, and the following pretreatment agent was applied at a drawing rate of 80% and then dried.
(Pretreatment agent)
Sodium alginate (resin component): 5 parts by weight Urea (hydrotropic agent): 10 parts by weight Sodium hydrogen carbonate (alkali agent): 5 parts by weight Ion exchange water: 80 parts by weight

(Ink application process)
The obtained ink was set in Nassenger V (manufactured by Konica Minolta). A solid image was formed using the obtained ink at main scanning 540 dpi × sub-scanning 540 dpi. In addition, dpi represents the number of ink droplets (dots) per 2.54 cm.

(Coloring process)
The fabric on which the image was formed was steam-treated for 8 minutes under the conditions of a relative humidity of 100% and a temperature of 103 ° C. to fix and develop the dye.

<Image evaluation>
The injection stability was evaluated by the following method.

(Injection stability)
The ink from the inkjet head was ejected for a certain time at 25 ° C. and 50% RH. Thereafter, the ink was allowed to stand for 30 minutes, and the ink was ejected again. The ejectability at that time was observed with a drop watcher. And the reinjection property after leaving for 30 minutes was evaluated based on the following criteria.
◎: Less than 200 shots can be re-injected with no defects by discarding (refreshing the ink on the nozzle surface by discarding) ○: More than 200 shots can be re-injected with no more than 500 shots ○ △: Rejection without defects by discharging over 500 shots and 1000 shots or less △: Injection failure recovered by maintenance (manual cleaning of nozzle surface) ×: Injection failure remains even after maintenance

The evaluation results of the inks of Examples 1 to 10 are shown in Table 1; the evaluation results of Examples 11 to 16 are shown in Table 2; the evaluation results of Examples 17 to 27 are shown in Table 3; Table 4 shows the ink evaluation results. In the composition column in the table, the unit of numerical values other than [VS group] / [VS group + SES group] is part by mass.

  As shown in Tables 1 to 3, each of the inks of Examples 1 to 27 having [VS group] / [VS group + SES group] of 0.2 or more and 0.95 or less has pH stability and low temperature storage. It can be seen that both stability and injection stability can be achieved.

  In particular, [VS group] / [VS group + SES group] is 0.4 or more (contrast with Examples 1 and 2, comparison with Examples 17 and 20 and 21), preferably 0.6 or more (Example 2 and 3) (comparison between Examples 21 and 18 and 19), it can be seen that the pH stability is improved. [VS group] / [VS group + SES group] is 0.9 or less (contrast with Examples 22 and 23), preferably 0.8 or less (contrast with Examples 4 and 5 and 10; Examples 19 and 22 It can be seen that the injection stability is improved when the contrast is.

  Moreover, it turns out that the injection stability of an ink increases because an ink further contains a moisturizer (contrast with Example 4 and 11-14, contrast with Example 23 and 25-26).

  In contrast, as shown in Table 4, the inks of Comparative Examples 1, 3, and 6 in which [VS group] / [VS group + SES group] are less than 0.2 all have low pH stability. I understand. On the other hand, it can be seen that the inks of Comparative Examples 2, 4, and 5 having [VS group] / [VS group + SES group] exceeding 0.95 have low low-temperature storage stability and ejection stability.

  According to the present invention, it is an ink containing a vinyl sulfone type reactive dye, and provides an ink jet printing ink that can achieve both pH stability, low temperature storage stability and ejection stability, and an ink jet printing method using the same. Can do.

P Fabric 2 Conveying means 21 Adhesive belt 22 Support roller 23 Conveying roller 24 Nip roller 5 Head carriage 6 Warm air applying means 6A Fan 6B Heating element

Claims (7)

A vinyl sulfone-type reactive dye, a water-soluble organic solvent, and water;
The vinyl sulfone type reactive dye is
An ink-jet printing ink comprising a compound having a sulfoxyethylsulfonyl group and a compound having a vinylsulfone group and satisfying the following formula (1).
Formula (1): 0.20 ≦ [VS group] / [VS group + SES group] ≦ 0.95
(In the formula (1),
[VS group]: content (mol) of vinyl sulfone group in the ink,
[VS group + SES group]: Total content of vinylsulfone group and sulfoxyethylsulfonyl group in ink (mol)) The inkjet textile printing ink of Claim 1 which satisfy | fills following formula (2).
Formula (2): 0.40 ≦ [VS group] / [VS group + SES group] ≦ 0.9 The inkjet textile printing ink according to claim 1 or 2 satisfying following formula (3).
Formula (3): 0.60 ≦ [VS group] / [VS group + SES group] ≦ 0.8   The inkjet textile printing ink as described in any one of Claims 1-3 whose content of the said vinyl sulfone type reactive dye is 15-30 mass% with respect to the total mass of an ink.   5. The water-soluble organic solvent according to claim 1, comprising at least one selected from the group consisting of 2-pyrrolidone, ε-caprolactam, 2,2-thiodiethanol, and ethylene urea. Inkjet printing ink. Forming the image on a fabric provided with a hydrophilic resin having a hydroxy group by discharging droplets of the ink-jet printing ink according to any one of claims 1 to 5 from a recording head;
And a step of fixing the image by heating the fabric on which the image is formed.   The inkjet printing method according to claim 6, wherein the fabric includes cellulose fiber or protein fiber.

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