JP2014156559A - Inkjet printing ink, and printing method of textile using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet printing ink used for coloring a polyamide fiber or a mixed spinning fiber containing the polyamide fiber, excellent in water fastness and washing fastness, and to provide a printing method using the same.SOLUTION: There is provided an inkjet printing ink used for coloring a polyamide fiber or a mixed spinning fiber containing the polyamide fiber, containing at least a dye represented by formula (1) or a salt or a mixture of them, water and a water-soluble organic solvent. In the formula (1), n and m are each independently an integer of 2 to 6, R is a hydrogen atom or the like, Q is an integer of 1 to 3, Rand Rare each independently a group selected from the group consisting of a hydrogen atom, C1-C3 alkoxy group, or the like.

Description

  The present invention relates to an ink for ink jet textile printing and a textile textile printing method using the same.

Compared with screen printing, roller printing, rotary printing, and other printing methods, inkjet printing of fibers using an inkjet printer eliminates the need for plate making processes; the digitized design can be printed directly through a computer. There are many merits such as being able to produce a wide variety of products even in small amounts; drastically reducing waste of pigment (dye) color paste, etc.
On the other hand, there are problems such as a slower printing speed and difficulty in reproducing dark colors than conventional plate-making textile printing. For this reason, ink-jet textile printing is often used in the range of sample manufacturing and small-scale production.
In recent years, the printing speed of inkjet printers has been greatly improved due to technological advances in computer image processing and printhead manufacturing. In addition to this, ink-jet textile printing has been popularized against the background of digitization of print design and diversification and small-lot production of print processing in the market.

  In ink-jet textile printing, usually four color ink sets of black, yellow, magenta (sometimes using red), and cyan (sometimes using blue) are used. As the performance of ink used for ink jet textile printing, it is desired that a dyed product having high image quality and high fastness can be provided and that the ejection stability is also excellent. In response to this demand, various inks have been proposed. However, conventional orange-violet inks, particularly red-magenta inks, have had problems such as poor wash fastness, water fastness, and poor light resistance. In addition, for the purpose of dyeing fibers (typically fabrics such as cloth and woven fabric), there is a strong demand for inks that are particularly excellent in fastness to washing and fastness to water.

  Patent Documents 1 and 2 disclose a dye represented by the above formula (1) that provides an image having high resistance to water, dirt, and light, and has high water solubility. Patent Documents 3 and 4 disclose inks containing the coloring matter represented by the formula (1).

Japanese Patent Laid-Open No. 9-2170818 US Patent Publication No. 2005/0160937 JP 2010-024444 A JP 2010-1000071 A

  An object of the present invention is to provide an ink for ink-jet printing used for dyeing polyamide fibers having excellent water fastness and washing fastness or a blended fiber containing polyamide fibers, and a printing method using the same.

As a result of intensive studies, the present inventors have found that the above problems can be solved by an ink for ink-jet printing containing a dye represented by the following formula (1) or a salt thereof, or a mixture thereof. Completed.
That is, the present invention relates to the following [1] to [6].
[1]
An ink for inkjet printing used for dyeing polyamide fibers or mixed fibers containing polyamide fibers, which contains at least a dye represented by the following formula (1) or a salt thereof or a mixture thereof, water, and a water-soluble organic solvent.

(In the formula, n and m each independently represents an integer of 2 to 6,
R represents a hydrogen atom or a C1-C6 alkyl group,
Q represents an integer of 1 to 3,
R ¹³ and R ¹⁴ each independently represents a group selected from the group consisting of a hydrogen atom, a ureido group, a C1-C3 alkyl group, a C1-C3 alkoxy group, and a C1-C4 acylamino group. )
[2]
The ink for inkjet textile printing according to the above [1], wherein R in the formula (1) is a hydrogen atom.
[3]
A method for ink-jet textile printing, comprising sequentially performing at least the following three steps of Step A to Step C using the ink for ink-jet textile printing according to [1] or [2].
Step A: A step of ejecting the ink droplets in accordance with a recording signal and attaching them to the fibers.
Step B: A step of fixing the dye in the ink droplets attached in Step A to the fiber by heat.
Step C: A step of washing unfixed pigment remaining on the fiber.
[4]
A fiber dyed by the ink jet printing method described in [3] above.
[5]
A method for improving the wash fastness of a polyamide fiber or a blended fiber containing a polyamide fiber, which is dyed using the ink for ink-jet printing according to the above [1] or [2].
[6]
A method for improving the fastness to washing of a polyamide fiber or a blended fiber containing a polyamide fiber, which uses the inkjet printing method according to the above [4].

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an ink for inkjet printing used for dyeing a polyamide fiber having excellent water fastness and washing fastness or a blended fiber containing polyamide fiber, and a printing method using the same.

  The present invention is described in detail below. In the present specification, unless otherwise specified, both the “%” and “part” numbers including the examples are described on a mass basis. Similarly, when simply described as “pigment”, it means “pigment or a salt thereof, or a mixture thereof”.

The dye represented by the formula (1) will be described.
n and m each independently represent an integer of usually 2-6, preferably 2-5, more preferably 2-4, and still more preferably 2-3. It is particularly preferable that both are integers of 3.

Examples of the C1-C6 alkyl group for R include a linear, branched, or cyclic alkyl group.
Specific examples thereof include linear ones such as methyl, ethyl, n-propyl, n-butyl, n-pentyl and n-hexyl; isopropyl, isobutyl, t-butyl, isopentyl, t-pentyl, isohexyl and t-hexyl. Branched chain such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.
Of these, linear or branched ones are preferable, and linear ones are more preferable.

Q represents an integer of 1 to 3, and an integer of 2 is particularly preferable. Specifically, Q represents the number of substitutions of a sulfo group whose substitution position is not specified on the naphthyl group. Although the substitution position of the sulfo group is not particularly limited, the substitution position of the nitrogen atom in formula (1) is preferably the 2-position, and the substitution is preferably performed at the following position.
1st place when Q is 1, or 4th to 8th place.
When Q is 2, positions 4 and 8; positions 5 and 7; positions 6 and 8; or positions 1 and 5
When Q is 3, 3rd, 6th, and 8th; 4th, 6th, and 8th.

Examples of the C1-C3 alkyl group for R ¹³ and R ¹⁴ include the same groups as those in the range of C1-C3 among the C1-C6 alkyl groups for R. The same applies to the preferred ones.

Examples of the C1-C3 alkoxy group for R ¹³ and R ¹⁴ include a linear, branched or cyclic alkoxy group.
Specific examples thereof include linear ones such as methoxy, ethoxy and n-propoxy; branched ones such as isopropoxy; cyclic ones such as cyclopropoxy.
Of these, linear or branched ones are preferable, and linear ones are more preferable.

Examples of the C1-C4 acylamino group for R ¹³ and R ¹⁴ include a linear acylamino group.
Specific examples thereof include linear ones such as formylamino, acetylamino, ethylcarbonylamino and n-propylcarbonylamino; branched ones such as isopropylcarbonylamino; cyclic ones such as cyclopropylcarbonylamino ;

Among the above, as the dye represented by the formula (1),
n and m are integers of 2 to 4,
R is a hydrogen atom,
Q is an integer of 2;
A dye in which one of R ¹³ and R ¹⁴ is a hydrogen atom and the other is a C1-C3 alkoxy group is preferred.

Although the specific example of the pigment | dye represented by said Formula (1) is given in following Table 1, the pigment | dye represented by this Formula (1) is not limited to these specific examples.
Further, “position” in Table 1 means the position described in the following formula (4) in the site where each group is substituted.

  Among the dyes represented by the formula (1), a dye represented by the following formula (2) is particularly preferable.

  The ink for inkjet textile printing (hereinafter also referred to as “ink” unless otherwise specified) is a pigment other than the pigment represented by the formula (1). I. Acid Yellow; C.I. I. Direct Yellow; and C.I. I. Selected from the group consisting of Reactive Yellow; I. You may further contain the yellow pigment | dye which has a number in the range which does not inhibit the effect obtained by this invention.

C. above. I. Examples of yellow dyes having numbers include C.I. I. Acid Yellow 1, 3, 11, 17, 18, 19, 23, 25, 36, 38, 40, 40: 1, 42, 44, 49, 59, 59: 1, 61, 65, 72, 73, 79, 99, 104, 110, 159, 169, 176, 184, 193, 200, 204, 207, 215, 219, 219: 1, 220, 230, 232, 235, 241, 242, 246; I. Direct Yellow 8, 11, 12, 21, 28, 33, 39, 44, 49, 50, 85, 86, 87, 88, 89, 98, 100, 110, 132, 144, 146; C.I. I. Reactive Yellow 2, 3, 18, 81, 84, 85, 95, 99, 102;

All the dyes described above may be contained in the ink as salts formed with inorganic or organic cations.
Specific examples of the inorganic cation when forming the salt include alkali metals such as lithium, sodium and potassium; group 2 elements of the periodic table such as calcium and magnesium; and ammonium (NH ₄ ⁺ ); Ions. Of these, salts formed with lithium, sodium, potassium and ammonium are preferred.
Examples of the organic cation include, but are not limited to, quaternary ammonium ions represented by the following formula (3).
The dye may be a free acid or a mixture of various salts thereof, and when the dye has a tautomer, also includes a free acid of the tautomer and various salts thereof. It may be a mixture. For example, any combination such as a mixture of sodium salt and ammonium salt, a mixture of free acid and sodium salt, a mixture of lithium salt, sodium salt and ammonium salt may be used.
Depending on the type of salt, the physical properties of the pigment such as solubility may be different. For this reason, selecting the kind of salt suitably as needed; and changing the ratio when including a some salt etc. are also performed preferably.
Any known method can be used for methods such as salt formation and salt exchange.

^{Z 1, Z 2, Z 3} , Z 4 in the formula (3) each independently represent a hydrogen atom, an alkyl group, hydroxyalkyl groups and hydroxyalkoxy alkyl group selected from the group consisting of ^{groups, Z} 1 ~ All of Z ⁴ are not hydrogen atoms.
Specific examples of the alkyl group of Z ¹ , Z ² , Z ³ and Z ^{4 in} the formula (3) include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Examples thereof include a linear or branched C1-C4 alkyl group.
Specific examples of the hydroxyalkyl group include hydroxy C1-C4 alkyl groups such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl and the like. .
Examples of hydroxyalkoxyalkyl groups include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl, etc. And a hydroxy C1-C4 alkoxy C1-C4 alkyl group. Among these, a hydroxy C1-C4 alkoxy C1-C4 alkyl group (preferably a hydroxyethoxy C1-C4 alkyl group) is preferable.
Of the above, particularly preferred are hydrogen atom; methyl; hydroxy C1-hydroxymethyl such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl and the like. C4 alkyl group; hydroxyethoxy C1-C4 such as hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl, etc. An alkyl group;

The pigment can be used in any state such as powder, lump, or wet cake. However, commercially available pigments have various qualities such as “industrial dyeing powder” and “inkjet”, and have different production methods, purity, etc., and liquid products. Among them, there are also products containing about 10 to 40% of an inorganic salt such as sodium chloride or sodium sulfate in the total mass.
As the ink for ink jet textile printing, it is preferable to use a coloring material having as few impurities as possible in order to improve the storage stability of the ink and the discharge accuracy from the ink jet printer. In addition, since water and the like that are not particularly subjected to purification operations include metal ions such as calcium ions and magnesium ions, when such unpurified water or the like is used in the ink, the ions and the like are mixed in the ink in a minute amount.
In the present specification, including these inorganic salts and metal ions, they will be described as “inorganic impurities” for the sake of convenience.
These inorganic impurities significantly deteriorate the solubility of the pigment in the ink and the storage stability of the ink itself, and also cause corrosion and wear of the ink jet printer head. For this reason, it is preferable to remove inorganic impurities from the ink. Examples of methods for removing these inorganic impurities include known methods such as ultrafiltration, reverse osmosis, and ion exchange.
The upper limit of the content of inorganic impurities that may be contained in the total mass of the ink is usually 1% or less, preferably 0.5% or less, more preferably 0.1% or less. The lower limit may be 0%, that is, below the detection limit of the detection device.

Examples of the water-soluble organic solvent contained in the ink include polyhydric alcohols and pyrrolidones. The content of the water-soluble organic solvent is usually 1 to 50%, preferably 5 to 40% with respect to the total mass of the ink.
Examples of polyhydric alcohols include C2-C6 alcohols having 2 to 3 hydroxy groups such as glycerin, 1,3-pentanediol, and 1,5-pentanediol; polyglyceryl ethers such as diglycerin and polyglycerin; polyoxy Polyoxy C2-C3 alkylene polyglyceryl ether such as ethylene polyglyceryl ether, polyoxypropylene polyglyceryl ether; mono-, di- or tri-C2-C3 alkylene glycol such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol; polyethylene glycol, Poly C2-C3 alkylene glycol having a repeating unit of 4 or more and a molecular weight of about 20,000 or less (preferably liquid) such as polypropylene glycol Polyhydric alcohols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monomethyl ether, triethylene glycol monoethyl ether Of C1-C4 monoalkyl ethers;
Examples of the pyrrolidones include pyrrolidones such as 2-pyrrolidone and N-methyl-2-pyrrolidone;
Among these, C2-C6 alcohol having 2 to 3 hydroxy groups; mono-, di- or tri-C2-C3 alkylene glycol; C1-C4 monoalkyl ether of polyhydric alcohol; and pyrrolidones are preferable.
The water-soluble organic solvent may be used alone or in combination.

  The ink contains, as necessary, an ink preparation agent such as a surfactant, a pH adjuster, and an antiseptic / antifungal agent as a component other than the pigment represented by the formula (1), water, and a water-soluble organic solvent. Furthermore, you may contain. The total amount of the ink preparation agent is usually 0 to 10%, preferably about 0.05 to 5% with respect to the total mass of the ink.

Examples of the surfactant include anionic, cationic, amphoteric, and nonionic surfactants.
Anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids or salts thereof, N-acyl methyl taurates, alkyl sulfates polyoxyalkyl ether sulfates Salt, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl sulfonate, diethylsulfate , Diethylhexyl sulfosuccinate, dioctyl sulfosuccinate and the like.
Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.
Examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, and imidazoline derivatives. Can be mentioned.
Nonionic surfactants include ethers such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether; Ester systems such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl -1-hexyne-3-acetylene alcohol such as ol; As another example, for example, Nissin Chemical Co., Ltd. under the trade name Surfynol ^TM 104,105PG50,82,420,440,465,485; Olfine ^TM STG; and the like.
Of these, Surfynol ^™ is preferred.
In the present specification, the superscript “TM” means a trademark.

As the pH adjuster, any substance can be used as long as the pH of the ink can be controlled in the range of 6.0 to 11.0. For example, alkanolamines such as diethanolamine, dimethylethanolamine and diethylethanolamine triethanolamine; hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonium hydroxide (ammonia water); or carbonic acid Examples include alkali metal carbonates such as lithium, sodium carbonate, and potassium carbonate; tris (hydroxymethyl) aminomethane;
Of these, triethanolamine is preferred. The content of the pH adjusting agent in the total mass of the ink is usually 0 to 2%, preferably 0.01 to 2%, more preferably 0.05 to 1%.

Examples of the antiseptic / antifungal agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, zinc pyridinethione-1-oxide, 1,2-benzisothiazolin-3-one, and 1-benz. Examples thereof include an amine salt of isothiazolin-3-one, and Proxel ^™ GXL manufactured by Avecia. Of these, Proxel ^™ GXL is preferred.

  The ink is obtained by mixing the components described above to form a solution. Moreover, it is preferable to remove impurities by filtering the ink obtained with a membrane filter or the like. The pore diameter of the membrane filter is usually 0.1 μm to 1 μm, preferably 0.1 μm to 0.5 μm.

  The viscosity of the ink at 25 ° C. is preferably in the range of 3 to 20 mPa · s when measured with an E-type viscometer; 20 to 40 mN / m when measured with a plate method. The viscosity of the ink is preferably adjusted to an appropriate value in consideration of the discharge amount of the printer; the response speed; the flight characteristics of the ink droplets; the characteristics of the inkjet head;

The ink-jet printing method is a fiber ink-jet printing method including sequentially performing at least the following three steps of Step A to Step C.
[Step A]
A step of ejecting the ink-jet printing ink droplets in accordance with a recording signal and attaching them to the fibers;
[Step B]
A step of fixing the pigment in the ink droplets adhered to the fiber in the step A to the fiber by heat;
[Step C]
A step of washing unfixed pigment remaining on the fiber.

As the fiber used in the ink jet textile printing method, polyamide fiber and blended fiber containing polyamide fiber are preferable. Examples of polyamide fibers include natural fibers such as silk and wool, and synthetic polyamide fibers such as nylon. Examples of the blended fiber include those containing at least these polyamide fibers and blended with other fibers.
Examples of the fiber include a fiber structure, and a fabric made of the fiber is preferable.

  For the purpose of full-color textile printing, the ink may be used as a yellow ink, and ink-jet textile printing may be performed as a four-color ink set in which magenta, cyan, and black inks are added. The pigments contained in the magenta, cyan, and black inks may be known ones and are not particularly limited. As the colorant of each color, a dye selected from the group consisting of an acid dye, a direct dye, and a reactive dye is preferable, and an acid dye is more preferable. When the four-color ink set is used, one kind of coloring matter may be contained in each of the magenta, cyan, and black inks, or two or more kinds may be used in combination.

As the step A, for example, a container (also referred to as an ink tank or an ink cartridge) filled with the ink is loaded at a predetermined position of the ink jet printer, and droplets of the ink are ejected in accordance with a recording signal. And a method of attaching ink to the fiber.
When obtaining a full-color dyed product, the above-described inks of the respective colors are filled in the respective containers, and these containers are similarly loaded into predetermined positions of the ink jet printer for use.
Some inkjet printers use, for example, a piezo method using mechanical vibration; a bubble jet (registered trademark) method using bubbles generated by heating; and the like. The inkjet textile printing method can be used with any type of printer.

In the step B, the fiber to which the ink is attached is allowed to stand at room temperature to 130 ° C. for about 0.5 to 30 minutes and preliminarily dried, and then subjected to a steaming treatment to fix the dye to the fiber under wet heat conditions. Methods and the like.
As the steaming treatment, it is preferable to place in an environment of humidity 80 to 100% and temperature 95 to 105 ° C. for 5 to 20 minutes.

As said process C, it is preferable to wash | clean the fiber after fixing a pigment | dye with water. In this cleaning, it may be cleaned with water containing a surfactant.
After performing the step C, the washed fiber is usually dried at 50 to 120 ° C. for 5 to 30 minutes to obtain a dried dyed product.

In addition to the above-mentioned three steps A to C, it is also preferable to perform a pretreatment for the purpose of preventing bleeding of the pigment on the fibers. As a pretreatment of this fiber, there is a step of using an aqueous solution containing at least both one or more types of paste material and a pretreatment pH adjuster as a fiber treatment solution, and preliminarily applying to the fiber before performing Step A. Can be mentioned. The fiber treatment liquid preferably further contains a hydrotropic agent. The paste, the pH adjusting agent for pretreatment, the hydrotropic agent and the like contained in the fiber treatment liquid may be referred to as “pretreatment agent” or the like.
Examples of a method for applying the fiber treatment liquid to the fiber include a padding method. The padding drawing ratio is preferably about 40 to 90%, more preferably about 60 to 80%.

  Examples of the paste contained in the fiber treatment liquid 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 and ethyl fibrin. Fiber derivatives such as hydroxyethyl cellulose and carboxymethyl cellulose; processed starches such as carboxymethyl starch; processed natural gums such as silac gum and roast bean gum; synthetic glues such as polyvinyl alcohol and polyacrylate; . Among these, natural gums such as guar and locust bean; processed natural gums such as silat gum and roast bean gum; and the like are preferable.

  As the pH adjuster for pretreatment contained in the fiber treatment solution, those which show acidity when used as an aqueous solution are preferable. Specific examples include ammonium salts such as ammonium sulfate, ammonium tartrate, and ammonium acetate. Of these, ammonium sulfate is preferred.

Examples of the hydrotropic agent contained in the fiber treatment liquid include urea such as urea, dimethylurea, thiourea, monomethylthiourea, and dimethylthiourea, and thiourea. Of these, urea is preferred.
One type of each pretreatment agent may be used alone, or two or more types may be used in combination, with the latter being preferred.

For example, when blended fibers are used, it is difficult to determine the content of the pretreatment agent contained in the fiber treatment liquid according to the blend ratio of the blended fibers.
As a guideline, the paste is 0.5 to 5% on a mass basis, the pH adjuster for pretreatment is 0.5 to 5%, and the balance is water, based on the total mass of the fiber treatment liquid. is there. When it further contains a hydrotropic agent, it is similarly 1 to 20%, and the balance is water.
The fiber treatment liquid is preferably acidic. The pH range is usually 7 or less, preferably 5-7.

The fiber dyed with the ink for ink jet textile printing of the present invention is excellent in the balance of chroma, dyeing density, color blur and light resistance. In addition, the water fastness is high, and particularly the fastness to washing is excellent. Furthermore, it is excellent also in various performances such as color tone and color reproduction range.
In addition, the ink can also exhibit ejection performance regardless of the frequency value in a printer equipped with an industrial inkjet head that requires high-viscosity ink.
Further, after ink jet printing, the printer is allowed to stand for a certain period of time, and the discharge property is good when discharge (printing) is started again.
Therefore, the ink for ink-jet printing of the present invention and the printing method using the ink are very suitable for printing of fibers, particularly polyamide fibers, or blended fibers containing polyamide fibers.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples.
Moreover, the temperature of the liquid measured the internal temperature, and operations such as reaction and salting out were performed under stirring unless otherwise specified.

[Synthesis example]
9.8 parts of cyanuric chloride were dissolved in 100 parts of ethyl acetate. A solution in which 22.4 parts of 2-[(4-amino-3-methoxyphenyl) azo] naphthalene-6,8-disulfonic acid was dissolved in 260 parts of water was reacted. At this time, the pH of the reaction solution was maintained at 8 to 8.5, and the temperature was maintained at 30 ° C. After 30 minutes, the reaction was heated to 50 ° C. and stirred at this temperature for 1 hour, then 20.0 parts of sodium 3-mercapto-1-propanesulfonate were added to the reaction. The reaction was heated at 90 ° C. for 3 hours and cooled to room temperature. A solution prepared by dissolving 12 parts of sodium acetate in 400 parts of ethanol was added to the obtained liquid. A solid precipitated from the obtained liquid was collected by filtration, washed with 300 parts of ethanol, and vacuum-dried at 60 ° C. to obtain a dye represented by the formula (2).
The maximum absorption wavelength (λmax) of the obtained dye in water was 395 nm.
In addition, the content of inorganic impurities in the total mass of the obtained dye was 10 ppm or less for both chlorine ions and sulfate ions, as determined by ion chromatography.
The structure of the obtained dye was confirmed by measuring mass spectrometry, ¹ H- and ¹³ C-NMR. As a result, it was confirmed that the dye was represented by the formula (2).

[Preparation of ink for inkjet printing]
Each component shown in Table 2 below was mixed and stirred for about 1 hour to obtain an ink. The obtained ink was filtered through a 0.45 μm membrane filter (trade name: cellulose acetate filter paper, manufactured by Advantech) to prepare a test inkjet printing ink. “Water” used for ink preparation is ion-exchanged water. A 10% sodium hydroxide aqueous solution is added so that the pH of the ink solution is 8 to 9, and water is added so that the total amount becomes 100 parts. It was adjusted.

[Preparation of test dyed fabric]
A fiber treatment solution containing 2 parts guar, 2 parts ammonium sulfate, 5 parts urea, and 91 parts water was prepared. Using the pad method, each cloth shown in Table 3 below is immersed in the prepared fiber treatment liquid, and after excess liquid is squeezed out with a rubber roller, the pretreatment is performed by drying at 60 ° C. went.
100%, 85%, 70%, 55%, and 40% of each of the pretreated fabrics obtained by using the ink-jet printing ink with an inkjet printer (trade name: PIXUS ip4100, manufactured by Canon Inc.) Ink-jet printing with 6 gradation levels of 25% and a gradation dyed product was obtained. This dyed product was pre-dried at 60 to 80 ° C., and then subjected to a steaming treatment at a humidity of 90% or more and 100 to 103 ° C. for 20 minutes. The obtained dyed product was washed with cold water for 5 minutes and then dried to obtain each test dyed fabric. The obtained dyed cloth was used as a test piece and used for various evaluation tests.

Using each dyeing cloth obtained as described above, a washing fastness test and a water fastness test were carried out. In the evaluation, each dyed cloth before and after the test was measured with a colorimeter and evaluated according to the evaluation criteria of each test described below.
In addition, the colorimeter used GRETAG-MACBETH make and a brand name: SpectroEye ^RTM , and measured the 100% gradation part.

[Washing fastness test]
Each dyed fabric obtained as described above was tested by the test method described in JIS L 0844. The dye residual ratio of each dyed cloth was measured and evaluated according to the following four evaluation criteria. The results are shown in Table 4 below.
[Evaluation criteria for washing fastness test]
A: 95% or more.
B: 80% or more and less than 95%.
C: 75% or more and less than 80%.
D: Less than 75%.

  As a result of the evaluation, nylon and silk showed very good results, but the cotton dyed fabric showed evaluation result D, and the fastness to washing was very bad. Note that a rating of about B or higher is a practically usable level.

[Water fastness test]
Each dyed fabric obtained as described above was tested by the test method described in JIS L 0846. The dye residual ratio of each dyed cloth was measured and evaluated according to the following four evaluation criteria. The results are shown in Table 5 below.
[Evaluation criteria for water fastness test]
A: 95% or more.
B: 80% or more and less than 95%.
C: 75% or more and less than 80%.
D: Less than 75%.

  As a result of the evaluation, nylon and silk showed very good results, but the cotton dyed cloth showed evaluation result D and the water fastness was very bad. Note that a rating of about B or higher is a practically usable level.

  The ink for inkjet printing used for dyeing the polyamide fiber or the blended fiber containing the polyamide fiber of the present invention provides a dyed cloth excellent in the balance of chroma, dyeing density, color blur (color difference), and light resistance, and a printing method thereof. It is extremely useful as an ink for inkjet printing and a textile printing method using the same.

Claims (6)

An ink for inkjet printing used for dyeing polyamide fibers or mixed fibers containing polyamide fibers, which contains at least a dye represented by the following formula (1) or a salt thereof or a mixture thereof, water, and a water-soluble organic solvent.

(In the formula, n and m each independently represents an integer of 2 to 6,
R represents a hydrogen atom or a C1-C6 alkyl group,
Q represents an integer of 1 to 3,
R ¹³ and R ¹⁴ each independently represents a group selected from the group consisting of a hydrogen atom, a ureido group, a C1-C3 alkyl group, a C1-C3 alkoxy group, and a C1-C4 acylamino group. )   The ink for inkjet textile printing according to claim 1, wherein R in the formula (1) is a hydrogen atom. A method for ink-jet textile printing, comprising sequentially performing at least the following three steps A to C using the ink-jet printing ink according to claim 1.
Step A: A step of ejecting the ink droplets in accordance with a recording signal and attaching them to the fibers.
Step B: A step of fixing the dye in the ink droplets attached in Step A to the fiber by heat.
Step C: A step of washing unfixed pigment remaining on the fiber.   A fiber dyed by the ink-jet printing method according to claim 3.   A method for improving the fastness to washing of a polyamide fiber or a blended fiber containing a polyamide fiber, which is dyed using the ink for inkjet printing according to claim 1.   A method for improving the fastness to washing of a polyamide fiber or a blended fiber containing a polyamide fiber, which uses the inkjet printing method according to claim 4.