JP2016098269A - Aqueous black ink for inkjet printing and inkjet printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a black ink for inkjet printing capable of color development of similar color tone on both surface and rear face at high concentration, hardly generating soaking of a dispersion dye from a terminal of a part to form an image and hardly growing particles having large volume during storing and an inkjet printing method using the black ink.SOLUTION: There is provided an aqueous black ink for inkjet printing containing water and a dispersion dye, where the dispersion dye contains at least one selected from an orange dispersion dye and a yellow dispersion dye, a red dispersion dye and a blue dispersion dye, the red dispersion dye is a compound represented by the formula (1) and the blue dispersion dye is a compound represented by the formula (2).SELECTED DRAWING: Figure 1

Description

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

  Fabric printing by the ink jet recording method (hereinafter also simply referred to as “inkjet printing”) is a process of ejecting ink from an ink jet head and landing on the fabric. The ink is contained by applying steam to the fabric on which the ink has landed. And fixing the dye to the fibers of the fabric, and washing the fabric to which the steam is applied to remove the unfixed dye. Ink-jet textile printing can be simplified because it is not necessary to produce a plate unlike textile printing by a conventional roller method. Inkjet textile printing can form an image with more excellent gradation by adjusting the type of ink and the place where it is landed. Furthermore, ink jet textile printing requires less ink than that required by conventional methods because it requires as much ink as is necessary for image formation.

  In ink jet textile printing, it is necessary to appropriately select the type of ink corresponding to the type of fabric forming the image. For example, in inkjet printing of polyester fibers and other artificial fibers having a hydrophobic structure, an image is formed on a fabric with an ink in which a disperse dye is dispersed in water.

  In inkjet printing, from the viewpoint of expanding the color gamut of an image to be formed, dyeing may be performed by combining black ink with yellow, magenta, and cyan inks. At this time, as the black ink, an ink containing a combination of a red disperse dye, a blue disperse dye, and at least one selected from an orange disperse dye and a yellow disperse dye is used. A technique for developing a high-density black hue is known.

  For example, Patent Document 1 discloses that a natural hue of black can be developed at various densities from high density to low density. I. Disperse Orange (hereinafter simply referred to as “DO”)-29, C.I. I. Disperse Red (hereinafter simply referred to as “DR”)-177 and C.I. I. Disclosed is a black ink containing Disperse Blue (hereinafter simply referred to as “DB”)-291: 1.

US Patent Application Publication No. 2007/0107626

  In inkjet textile printing, not only the surface of the fabric on which ink is landed (hereinafter simply referred to as “front surface”) but also the surface of the opposite fabric (hereinafter simply referred to as “back surface”) has the same color tone. It may be required to form an image. However, the conventional black ink sometimes does not have the same color tone on the front and back surfaces of the fabric.

  In addition, when inkjet printing is performed using a black ink containing a combination of disperse dyes of a plurality of colors, one or a plurality of disperse dyes may ooze out of the image from the end of the part where the image is to be formed. Yes, the image may become unclear.

  In addition, if the disperse dye in the black ink is deposited in the ink during storage or ejection and becomes a large volume particle, the narrow flow path and nozzle of the ink jet textile printing apparatus are blocked, and the ejection property of the ink from the ejection head is reduced. May decrease. For this reason, black ink for ink-jet textile printing is required to prevent large-volume particles from growing during storage from the viewpoint of improving the injection property.

  In view of the above circumstances, the present invention can develop a similar color tone at a high density on both the front surface and the back surface, and it is difficult for the disperse dye to ooze out from the end of the portion where an image is to be formed. In addition, an object of the present invention is to provide a black ink for inkjet printing and a method for inkjet printing using such a black ink, in which large-volume particles are difficult to grow during storage.

The present invention relates to the following water-based black ink for inkjet printing.
[1] An aqueous black ink for ink-jet printing containing water and a disperse dye,
The disperse dye includes at least one selected from an orange disperse dye and a yellow disperse dye, a red disperse dye, and a blue disperse dye,
The red disperse dye is a compound represented by the formula (1),
The black ink, wherein the blue disperse dye is a compound represented by the formula (2).

In the formula (1), R ₁ is a nitro group or a chloro group, R ₂ is a hydrogen atom when R ₁ is a nitro group, a chloro group when R ₁ is a chloro group, and R ₃ is Any one of R ₄ is a cyanoethyl group, and the other of R ₄ is one selected from the group consisting of an ethyl group, a cyanoethyl group, an acetoxyethyl group, and an ethyl carbonate ethyl group. is there.

In formula (2), R ₅ is independently one selected from the group consisting of a cyano group, a nitro group, and a bromo group, provided that when either R ₅ is a nitro group, the other is a nitro group. When either R ₅ is a bromo group, the other is not a bromo group, R ₆ is a methyl group or an ethyl group, and R ₇ is a hydrogen atom or a methoxy group. And R ₈ is independently one selected from the group consisting of a hydrogen atom, an ethyl group, a cyanoethyl group, a benzyl group, an acetoxyethyl group, and a methoxyethyl group. And when at least one of R ₈ is an acetoxyethyl group, R ₇ is an ethoxy group; otherwise, R ₇ is a hydrogen atom or a methoxy group.

[2] The black ink according to [1], wherein the maximum absorbance is 4000 or more.
[3] The black ink according to [1] or [2], wherein the disperse dye further includes a blue disperse dye having a maximum absorption wavelength of 630 nm to 680 nm.
[4] The black ink according to any one of [1] to [3], wherein a mass of the disperse dye is 10% by mass to 15% by mass with respect to a total mass of the black ink.
[5] The black ink according to any one of [1] to [4], wherein a mass of the disperse dye is 12% by mass or more and 15% by mass or less with respect to a mass of the whole black ink.
[6] The red disperse dye is C.I. I. Disperse Red-154 or C.I. I. The black ink according to any one of [1] to [5], which is Disperse Red-177.
[7] The blue disperse dye is C.I. I. Disperse Blue-79 or C.I. I. The black ink according to any one of [1] to [6], which is Disperse Blue-165.
[8] It further contains at least one selected from polyethylene glycol having a molecular weight of 400 to 1000, polypropylene glycol having a molecular weight of 400 to 1000, and a compound represented by formula (3), [1 ] The black ink according to any one of [7] to [7].

In the formula (3), R ₁₁ represents an ethylene glycol group or a polypropylene glycol group, and x, y, and z are all positive integers, and x + y + z = 3-30.

The present invention also relates to an inkjet printing method shown below.
[9] An inkjet printing method for forming an image on a fabric with black ink, wherein the black ink is the black ink according to any one of [1] to [8]. .
[10] The inkjet printing method according to [9], wherein the fabric is a fabric in which an image forming portion includes a polyester fiber.

  According to the present invention, the same color tone can be developed at a high density on both the front surface and the back surface, the bleed of the disperse dye from the end of the portion where the image is to be formed hardly occurs, and during storage Provided are a black ink for inkjet printing and a method for inkjet printing using such a black ink, in which large-volume particles are difficult to grow.

FIG. 1 is a diagram schematically showing a part of the configuration of an ink jet printing apparatus capable of performing the image forming process of the ink jet textile printing method of the present invention.

1. Aqueous Black Ink for Ink-jet Printing The aqueous black ink for ink-jet printing according to the present invention (hereinafter also simply referred to as “black ink of the present invention”) contains water and a disperse dye. The black ink of the present invention includes, as a disperse dye, a red disperse dye, a blue disperse dye, and at least one selected from an orange disperse dye and a yellow disperse dye.

  The black ink of the present invention develops a good color tone on the back side of the ink-jet printed fabric, thereby reducing the difference between the color tone of the front surface and the color tone of the back surface, and hardly causing bleeding from the edge of the image. . This is considered to be due to the following reasons.

  When steam is applied to the fabric landed with ink droplets, the movement of the polymer constituting the fiber of the fabric is activated by heat, and the fiber structure of the polyester in which the hydrophobic disperse dye dissolved in the high-temperature steam is the hydrophobic fabric Easy to penetrate. In this way, the disperse dye penetrates into the fiber structure and is fixed, whereby the fabric is colored. At this time, among the plurality of disperse dyes contained in the ink droplets, disperse dyes that are difficult to dissolve in the vapor are more hydrophobic and are more easily distributed to the fiber structure than the vapor, and penetrate into the fiber structure and fix. Therefore, it is difficult to diffuse to the back surface through the surface of the fabric fiber structure. On the other hand, disperse dyes that are easily dissolved in vapor are less hydrophobic and thus are more easily distributed to the vapor than the fiber structure, and are less likely to penetrate into the fiber structure, so that they are likely to diffuse through the surface of the fiber structure to the back surface of the fabric. For this reason, if there is a difference in solubility in vapor among disperse dyes, the color of disperse dyes that are difficult to diffuse to the back side (hard to dissolve in vapor) on the back side of the fabric easily diffuses to the back side (dissolves in vapor). The difference between the color tone of the surface of the fabric and the color tone of the back surface is increased because it is less likely to develop than the color tone of the disperse dye.

  In addition, disperse dyes that are easily dissolved in vapor are not easily fixed by penetrating into the fiber structure, and are easily diffused along the surface of the fiber, so that they are easily diffused to the outside of the image end and cause bleeding at the image end.

  According to the knowledge of the present inventors, particularly when there is a difference in solubility in vapor (ease of penetration into the fiber structure) between the red disperse dye and the blue disperse dye contained in the black ink. In addition, the difference between the color tone of the surface of the fabric and the color tone of the back surface is increased, and bleeding at the edge of the image tends to occur.

  If the ink contains a disperse dye having a solubility that is too high, the disperse dye having a high solubility dissolves in the water in the ink, and promotes crystal growth of other disperse dyes that are not dissolved. Particles may form (Ostwald growth). When such a large volume of particles is formed, the ink ejectability from the ejection nozzle may be lowered. On the other hand, disperse dyes with too low solubility have low solubility in water at room temperature, and thus precipitate and aggregate during storage of the ink, which may reduce the storage and ejection properties of the ink.

  Further, when the content of each disperse dye in the black ink is increased in order to develop a high concentration of black, the viscosity of the ink is increased and the ejection property is deteriorated. In order to develop a high concentration of black without increasing the content of the disperse dye, the black ink contains a red disperse dye and a blue disperse dye having a converted absorbance per gram of dye of 35,000 to 200,000. Is desirable.

  The converted absorbance per gram of the dye is obtained by diluting the disperse dye with acetone to a concentration such that the maximum absorbance is in the range of 0.5 to 1.0, and using a spectrophotometer (UV-VIS SPECTROTOPOMETER V-550, JASCO Corporation). The product can be obtained by measuring the absorbance of the diluted solution and multiplying the measured value by the dilution factor.

  According to the knowledge of the present inventors, the red disperse dye having the structure represented by the formula (1) and the blue disperse dye having the structure represented by the formula (2) have a difference in solubility in vapor. It is small, its solubility is neither too high nor too low, and each converted absorbance also satisfies the above conditions. Therefore, the black ink of the present invention containing these disperse dyes has a small difference between the color tone of the surface of the fabric and the color tone of the back surface, hardly causes bleeding at the edge of the image, and has the ink storage stability and ejection. Good properties.

  From the viewpoint of developing high density black, the black ink of the present invention preferably has a maximum absorbance of 4000 or more. From the viewpoint of developing higher density black, the maximum absorbance of the black ink of the present invention is more preferably 5500 or more.

  The maximum absorbance of the black ink is obtained by diluting the black ink with acetone, measuring the collection spectrum of the visible part with a spectrophotometer (UV-VIS SPECTROTOPOMETER V-550, manufactured by JASCO Corporation), and measuring the absorbance at the wavelength at which the absorbance is maximum. It can be obtained by multiplying the absorbance value of x by the dilution factor. The dilution factor is preferably set so that the maximum absorbance measurement is between 0.5 and 1.0.

  Hereinafter, the ink according to the present invention will be described in more detail through a detailed description of each component.

1-1. Disperse dye The disperse dye contains at least one selected from a red disperse dye, a blue disperse dye, and an orange disperse dye and a yellow disperse dye. The disperse dye may contain other disperse dyes as long as the ink exhibits a black color when the fabric is dyed and the effect of the present invention can be prepared. In the present invention, a dye is specified by a color index name registered in a color index (ColorIndex) which is a database jointly created by the British Dye Dyeing Society and the American Textile Chemistry and Dyeing Technology Association.

  From the viewpoint of adjusting the viscosity of the black ink of the present invention within a range where the color development is better and the discharge head can be discharged better, the content of the disperse dye is 3% by mass or more to 20% by mass with respect to the total mass of the ink. It is preferable that it is below mass%. From the viewpoint of developing higher density black, the content of the disperse dye is more preferably 8% by mass to 15% by mass with respect to the total mass of the ink, and is preferably 10% by mass to 15% by mass. More preferably, it is more preferably 12% by mass or more and 15% by mass or less.

1-1-1. Red disperse dye The red disperse dye is a compound represented by the formula (1). Only one type of red disperse dye may be contained in the black ink of the present invention, or two or more types may be contained.

In Formula (1), R ₁ is a nitro group or a chloro group, R ₂ is a hydrogen atom when R ₁ is a nitro group, and is a chloro group when R ₁ is a chloro group, R ₃ Is a hydrogen atom or a methyl group, one of R ₄ is a cyanoethyl group, and the other of R ₄ is one selected from the group consisting of an ethyl group, a cyanoethyl group, an acetoxyethyl group, and an ethyl carbonate ethyl group It is.

  Examples of the compound represented by the formula (1) include DR-145, DR-152, DR-154 and DR-177.

  Since the color density of the disperse dye is higher, DR-154 and DR-177 are preferable from the viewpoint that the combination of disperse dyes can be easily adjusted so as to form a black ink that forms a higher density black image.

  The red disperse dye may be contained in the ink together with other disperse dyes so long as the desired black color tone is obtained. For example, the red disperse dye may be 2 in the total mass of the black ink of the present invention. It is 8 mass% or more and 5.0 mass% or less.

1-1-2. Blue-based disperse dye The blue-based disperse dye is a compound represented by the formula (2). Only one kind of blue disperse dye may be contained in the black ink of the present invention, or two or more kinds thereof may be contained.

In formula (2), R ₅ is independently one selected from the group consisting of a cyano group, a nitro group, and a bromo group, provided that when either R ₅ is a nitro group, the other is a nitro group. When either R ₅ is a bromo group, the other is not a bromo group, R ₆ is a methyl group or an ethyl group, and R ₇ is a hydrogen atom or a methoxy group. And R ₈ is independently one selected from the group consisting of a hydrogen atom, an ethyl group, a cyanoethyl group, a benzyl group, an acetoxyethyl group, and a methoxyethyl group. And when at least one of R ₈ is an acetoxyethyl group, R ₇ is an ethoxy group; otherwise, R ₇ is a hydrogen atom or a methoxy group.

  Examples of the compound represented by the formula (2) include DB-79, DB-165, DB-165: 1, DB-183, DB-257, DB-281 and DR-291.

  DB-79 and DB-165 are preferred from the viewpoint of enhancing the ejection properties from the inkjet head and the ink storage stability.

  The blue disperse dye may be contained in the ink together with other disperse dyes so long as the desired black color tone can be obtained. For example, the content of the blue disperse dye is 2 with respect to the total mass of the black ink of the present invention. It is 0.0 mass% or more and 3.5 mass% or less.

1-1-3. Yellow disperse dye or orange disperse dye The yellow disperse dye or orange disperse dye is contained in the ink in combination with the red disperse dye and the blue disperse dye. The yellow disperse dye or the orange disperse dye may be any of the black inks of the present invention as long as the ink exhibits a black color when the fabric is dyed and the effects of the present invention can be produced. Only one of them may be contained, or both may be contained. Two or more yellow disperse dyes or two or more orange disperse dyes may be contained in the black ink of the present invention.

  Examples of the yellow disperse dye include C.I. I. Disperse Yellow (hereinafter also simply referred to as “DY”) DY-3), DY-4, DY-5, DY-7, DY-9, DY-13, DY-23, DY-24, DY- 30, DY-33, DY-34, DY-42, DY-44, DY-49, DY-50, DY-51, DY-54, DY-56, DY-58, DY-60, DY-63, DY-64, DY-66, DY-68, DY-71, DY-74, DY-76, DY-79, DY-82, DY-83, DY-85, DY-86, DY-88, DY- 90, DY-91, DY-93, DY-98, DY-99, DY-100, DY-104, DY-108, DY-114, DY-116, DY-118, DY-119, DY-122, DY-124, DY-126, DY-1 5, DY-140, DY-141, DY-149, DY-160, DY-162, DY-163, DY-164, DY-165, DY-179, DY-180, DY-182, DY-183, DY-184, DY-186, DY-192, DY-198, DY-199, DY-202, DY-204, DY-210, DY-211, DY-215, DY-216, DY-218, DY- 224, DY-227, DY-231 and DY-232.

  DY-54, DY-114, DY-149, DY-160, and DY-163 are preferred from the viewpoint of making the black hue natural and developing a color at a desired density.

  Examples of the orange disperse dye include DO-1, DO-3, DO-5, DO-7, DO-11, DO-13, DO-17, DO-20, DO-21, DO-25, DO-29, DO-30, DO-31, DO-32, DO-33, DO-37, DO-38, DO-42, DO-43, DO-44, DO-45, DO-46, DO- 47, DO-48, DO-49, DO-50, DO-53, DO-54, DO-55, DO-56, DO-57, DO-58, DO-59, DO-61, DO-66, DO-71, DO-73, DO-76, DO-78, DO-80, DO-89, DO-90, DO-91, DO-93, DO-96, DO-97, DO-119, DO- 127, DO-130, DO-139, and DO-142.

  DO-29, DO-32, DO-47, DO-61, and DO-73 are preferable from the viewpoint of making the black hue natural and developing the color at a desired density.

  The total content of the yellow disperse dye or the orange disperse dye may be an amount that can be obtained in the ink together with the other disperse dyes so that a desired black color tone can be obtained. It is 2.5 mass% or more and 3.5 mass% or less with respect to the total mass.

1-1-4. Long wavelength blue disperse dyes Other disperse dyes include blue disperse dyes having a maximum absorption wavelength of 630 nm or more and 680 nm or less (hereinafter also simply referred to as “long wavelength blue disperse dyes”). The long wavelength blue disperse dye increases the absorption on the long wavelength side of the black ink of the present invention, and can broaden the wavelength distribution of light that can be absorbed by the black ink of the present invention. An image formed by black ink with low absorption on the long wavelength side appears to be black under light that contains little long wavelength light such as light from a fluorescent lamp, but it contains a lot of long wavelength light like sunlight. Under the light it contains, it may appear reddish due to the reflection of long wavelength light that is difficult to absorb. However, if the black ink of the present invention contains the long-wavelength blue disperse dye and the absorption on the long-wavelength side is increased, the formed image can absorb the long-wavelength light more sufficiently. The color looks more similar regardless of the spectral distribution of the light. Only one type of long wavelength blue disperse dye may be contained in the black ink of the present invention, or two or more types may be contained.

  Examples of long wavelength blue disperse dyes include DB-60.

  From the viewpoint of reducing the difference in hue due to the spectral distribution of the irradiated light, the content of the long-wavelength blue disperse dye is 1.6% by mass or more and 2.6% by mass or less with respect to the total mass of the ink. It is preferable.

1-1-5. Other disperse dyes Other disperse dyes include red disperse dyes that are not compounds represented by formula (1), blue disperse dyes that are not compounds represented by formula (2), and violet disperse dyes and green. Disperse dyes of colors other than those described above, including system disperse dyes, are included. As for the other disperse dyes, only one kind may be contained in the black ink of the present invention, or two or more kinds may be contained.

  Examples of red disperse dyes that are not compounds represented by the formula (1) include DR-179 and DR-191.

  Examples of blue disperse dyes that are not compounds represented by formula (2) include DB-60.

1-2. Other components The black ink of the present invention is a water-soluble organic solvent, a dispersant, an antiseptic or an antifungal agent, a pH adjuster, a dye dissolution aid, an antifoaming agent, a conductive material, as long as the effects of the present invention are exhibited. A rate adjusting agent, a deep dyeing agent, a leveling agent or a penetrating agent may be contained. One of these components may be contained in the black ink of the present invention, or two or more thereof may be contained.

1-2-1. Dispersant The dispersant can increase the dispersibility of the disperse dye and suppress the generation of bubbles, the gelation of the ink, and the increase in the viscosity of the ink in the black ink of the present invention. Dispersants have the ability to affect wetting ability, micronization ability, dispersion stability, dyeability to fabric, fixing rate, leveling property, transferability, fastness and resistance to tarring at high temperatures. In consideration, it can be selected according to the disperse dye.

  Examples of dispersants include formalin condensate of sodium creosote oil sulfonate, formalin condensate of sodium cresol sulfonate and sodium 2-naphthol-6-sulfonate, formalin condensate of sodium cresol sulfonate, sodium phenol sulfonate Formalin condensate, formalin condensate of sodium β-naphthol sulfonate, formalin condensate including sodium β-naphthalene sulfonate and sodium β-naphthol sulfonate, alkylene oxide including ethylene oxide and propylene oxide, fatty alcohol, fatty amine, Alkylatable compounds including fatty acids, phenols, alkylphenols and carboxylic acid amines, lignin sulfonates, sodium paraffin sulfonates, alpha-olefins and Copolymer of water maleic acid, as well as known comb block polymers.

  Examples of comb-type block polymers include DISPERBYK-190, DISPERBYK-194N, DISPERBYK-2010, DISPERBYK-2015 and BYK-154 (BIC Chemie, "DISPERBYK" is a registered trademark of the company), and JONCRYL PDX-6102B, JONCRYL PDX -6124, JONCRYL JDX-6539 and JONCRYL JDX-6500 (BASF, “JONCRYL” is a registered trademark of the same company).

  The amount of the dispersant can be 20 parts by mass or more and 200 parts by mass or less when the total mass of the disperse dye is 100 parts by mass. By making the amount of the dispersant 20 parts by mass or more, the dispersibility of the disperse dye is further increased. By setting the amount of the dispersant to 200 parts by mass or less, it is possible to suppress a decrease in injection property due to the dispersant.

1-2-2. Water-soluble organic solvents Examples of water-soluble organic solvents include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, alcohols containing sec-butanol and t-butanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene Glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, compounds represented by formula (3) and other glycerin, hexanetriol, thiodiglycol, 1,2-butanediol, 1,2-pentane Diols, polyhydric alcohols including 1,2-hexanediol and 1,2-heptanediol, ethanolamine, diethanolamine, triethanolamine, N -Methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, amines containing pentamethyldiethylenetriamine and tetramethylpropylenediamine, formamide, N, N An amide containing dimethylformamide and N, N-dimethylacetamide, a heterocyclic compound containing 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, 2-oxazolidone and 1,3-dimethyl-2-imidazolidinone; Sulfoxides, including dimethyl sulfoxide, and alkyl ethers of diethylene glycol, triethylene glycol alkyl ethers and dipropyl It includes glycol ethers containing an alkyl ether of glycol.

In the formula (3), R ₁₁ represents an ethylene glycol group or a polypropylene glycol group, and x, y, and z are all positive integers, and x + y + z = 3-30.

  From the viewpoint of adjusting the penetration of the disperse dye into the fiber structure of the fabric and reducing the color difference between the front and back sides of the fabric, the water-soluble organic solvent is a polyethylene glycol having a molecular weight of 400 to 1000, and a polypropylene having a molecular weight of 400 to 1000. It is preferable to include at least one selected from glycol and a compound represented by formula (3), and from the above viewpoint, polyethylene glycol having a molecular weight of 400 or more and 1000 or less is more preferable.

The content of these water-soluble organic solvents can be 2% by mass or more and 20% by mass or less based on the total mass of the black ink. By setting the content of these water-soluble organic solvents to 2% by mass or more based on the total mass of the black ink, the color tone difference between the front and back sides of the fabric can be further reduced. By setting the content of these water-soluble organic solvents to 20% by mass or less with respect to the mass of the entire black ink, it is possible to make it more difficult to increase the viscosity of the ink and to make the inkjet ejection unstable.

  The total amount of the water-soluble organic solvent can be 20% by mass or more and less than 70% by mass with respect to the total mass of the black ink of the present invention. By setting the amount of the water-soluble organic solvent to 20% by mass or more with respect to the total mass of the black ink of the present invention, the dispersibility of the disperse dye is further increased and the injection property is further increased. By making the amount of the water-soluble organic solvent less than 70% by mass with respect to the total mass of the black ink of the present invention, the drying property of the black ink of the present invention is improved even when the water-soluble organic solvent is contained.

1-2-3. Examples of antiseptics or antifungal agents include aromatic halogen compounds, methylene dithiocyanates, halogenated nitrogen sulfur compounds, 1,2-benzisothiazolin-3-ones (for example, Proxel GXL (arch chemical) And Proxel are registered trademarks of the company)).

1-2-4. Surfactants Examples of surfactants include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates and fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols And nonionic surfactants such as polyoxyethylene / polyoxypropylene block copolymers, cationic surfactants such as alkylamine salts and quaternary ammonium salts, and silicone-based and fluorine-based surfactants.

1-3. Physical Properties of the Black Ink of the Present Invention The viscosity of the black ink of the present invention at 25 ° C. is preferably 1 mPa · s or more and 40 mPa · s or less, from the viewpoint of further improving ink ejection properties, and 5 mPa · s or more and 40 mPa · s or less. More preferably, it is more preferably 5 mPa · s or more and 20 mPa · s or less. The viscosity of the ink can be measured at 25 ° C. and 20 rpm with an E-type viscometer (for example, V-25, manufactured by Toki Sangyo Co., Ltd.).

  The surface tension of the black ink of the present invention at 25 ° C. is preferably 25 mN / m or more and 50 mN / m or less. If the surface tension is 25 mN / m or more, image bleeding is less likely to occur. When the surface tension is 50 mN / m or less, the black ink of the present invention is more easily penetrated by the fabric. The viscosity of the ink can be measured by, for example, CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.

1-4. Preparation of the black ink of the present invention The black ink of the present invention can be prepared by mixing the disperse dye and water, and optionally the other components contained therein, and dispersing the disperse dye. The disperse dye may be dispersed by a disperser including a ball mill, a sand mill, a line mill, and a high-pressure homogenizer. From the viewpoint of preventing nozzle clogging and emitting stably, the disperse dye is preferably dispersed so that the volume average particle size is 300 nm or less and the maximum particle size is 900 nm or less. The volume average particle size of the disperse dye was determined by using a Zetasizer 1000, manufactured by Malvern Co. (“Zeta Sizer” is a registered trademark of Malvern Co., Ltd.), diluted 200 times, and the ink was cooled to room temperature (25 ° C.) by a dynamic light scattering method. Can be measured.

2. Inkjet Textile Printing Method The inkjet textile printing method of the present invention is an inkjet textile printing method in which an image is formed on a fabric with black ink, wherein the black ink is the black ink described above. The inkjet textile printing method of the present invention can be performed in the same manner as a known inkjet textile printing method except that the black ink of the present invention described above is used as an inkjet textile ink.

  For example, the inkjet textile printing method of the present invention includes a step of ejecting droplets of the black ink of the present invention from a recording head toward a fabric (image forming step), and a dye contained in the black ink of the present invention landed on the fabric. A step of fixing the fabric to the fibers of the fabric (coloring step), and a step of washing the fabric having the dye fixed on the fibers to remove the dye that could not be fixed to the fibers (washing step). The inkjet textile printing method of the present invention may further include a step of applying a pretreatment agent to the fabric (pretreatment step) or a step of drying the washed fabric (drying step) as necessary.

2-1. Image Forming Process The image forming process is a process for forming a pre-colored image by discharging the ink-jet ink droplets of the present invention from the recording head toward the fabric. For example, an image before color development can be formed by ejecting ink droplets from a recording head and landing on the fabric while moving the fabric relative to a head carriage on which a plurality of recording heads are mounted. . When an image is formed using a plurality of color inks including the black ink of the present invention, the ink droplets for each color may be ejected separately or simultaneously. From the viewpoint of suppressing bleeding of the pre-colored image, this step may be performed by heating the fabric as necessary.

2-2. Color development step The color development step is a step in which high-temperature steam is applied to the fabric on which an image before color development is formed to fix the dye to the fibers of the fabric. The original hue is developed by the coloring process. Examples of methods for fixing dyes to fabric fibers include steaming, HT steaming, HP steaming, thermofix, alkali pad steam, alkali blotch steam, alkali shock, and alkali cold fix. Law included. When high temperature steam is applied with an HT steamer, it is preferably treated at 160 ° C. to 180 ° C. for 5 minutes to 20 minutes, and when high pressure steam is applied with an HP steamer, it is about 130 ° C. to 140 ° C. It is preferable to process for 30 minutes.

2-3. Washing step The washing step is a step of washing the fabric after the color developing step to remove the dye and pretreatment agent that could not be fixed to the fibers of the fabric. In this step, it is sufficient that the dye and the pretreatment agent can be removed, and the fabric may be washed with water, or the fabric may be washed with a soaping solution. Examples of the soaping liquid include a mixed liquid of caustic soda, a surfactant, and hydrosulfite.

2-4. Pre-treatment step The method of the present invention provides a pre-treatment step before the image forming step to prevent the ink from bleeding on the fabric and obtain a water-soluble polymer as a paste. You may give the pre-processing agent to contain to a fabric previously. Examples of the method for applying the pretreatment agent include a pad method, a coating method, and a spray method. The applied amount (squeezing rate) of the pretreatment agent may be, for example, 0.2% by mass or more and 90% by mass or less with respect to the total mass of the fabric, although it depends on the type of fabric and its application.

  Examples of the water-soluble polymer include natural water-soluble polymers and synthetic water-soluble polymers. Examples of natural water soluble polymers include starches including corn and wheat, cellulose derivatives including carboxymethylcellulose, methylcellulose and hydroxyethylcellulose, polysaccharides including sodium alginate, guar gum, tamarind gum, locust bean gum and gum arabic, And protein substances including gelatin, casein and keratin. Examples of the synthetic water-soluble polymer include polyvinyl alcohol, polyvinyl pyrrolidone, and an acrylic acid polymer.

  The pretreatment agent preferably further contains a pH adjusting agent. From the viewpoint that a clear image can be formed at a higher density, the pH adjuster is more preferably an acid. Examples of pH adjusters that are acids include citric acid, malic acid and tartaric acid.

  The pretreatment agent may further contain optional components including a reduction inhibitor, a chelating agent, and a preservative as necessary. Examples of the reduction inhibitor include sodium m-nitrobenzenesulfonate. Examples of chelating agents include aminopolycarboxylates, hydroxycarboxylates, polycarboxylates, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid and diethylenetriaminepentaacetic acid. Examples of preservatives include aromatic halogen compounds including isopropyl N- (3-chlorophenyl) carbamate, methylene dithiocyanate and 1,2-benzisothiazolin-3-one.

2-5. Drying step The drying step is a step of drying the washed fabric. Examples of drying methods include non-mechanical drying by squeezing or drying the washed fabric, and mechanical drying by a dryer (heat roll or iron).

2-6. Fabric The fabric is composed mainly of fibers including cellulosic fibers, amide fibers, polyester fibers, polyurethane fibers, and acrylic fibers at least at a site where an image is formed. Examples of fibers include cotton, hemp, wool, silk, viscose rayon, cupra rayon, polynosic, vinylon, nylon, acrylic, polyurethane, rayon polyurethane, polyester and acetate. From the viewpoint that the disperse dye develops color well, it is preferable that the portion where the image is formed is a fabric mainly composed of polyester fibers. From the viewpoint of further improving the fixability of the disperse dye, the radius of the fiber is preferably 10d to 100d.

2-7. Inkjet printing apparatus The image forming step can be carried out by mounting the black ink of the present invention on a conventionally known inkjet printing apparatus.

  FIG. 1 is a partial schematic diagram illustrating an example of the configuration of an inkjet recording apparatus. The ink jet recording apparatus includes a transport mechanism 2 that transports a fabric, a head carriage 5 that mounts a plurality of recording heads (not shown) that eject ink jet ink onto the fabric, and a warm air mechanism 6 that blows warm air onto the fabric. .

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

  The ink jet recording apparatus applicable to the present invention may include an ink control unit (not shown) that controls ejection of each color ink in accordance with set image forming conditions.

  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 recording heads mounted on the head carriage 5 eject ink droplets of the ink jet ink of the present invention, 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 controllable wind or warm air is blown from the warm air mechanism 6 to dry the image formed on the fabric P.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not construed as being limited by these descriptions.

[Preparation of dispersion]
Disperser DISPERBYK-190 (comb block polymer dispersant, acid value 10 solid content 40%, manufactured by Big Chemie) and ion-exchanged water are stirred and mixed until uniform, and then each disperse dye described in Table 1 is added. After premixing, dynamic light scattering using a sand grinder filled with 50% by volume of 0.5 mm zirconia beads and using Zetasizer 1000, Malvern (“Zetasizer” is a registered trademark of the company) Dispersion 1 was prepared until the Z-average particle size measured by the method was in the range of 90 nm to 180 nm, and the solid content of the dye was 20% by mass. The dispersant, ion-exchanged water, and disperse dye were mixed at the following mass ratio.
Dispersant: 12.5 parts by mass Ion exchange water: 67.5 parts by mass Disperse dye: 20.0 parts by mass

  The "converted absorbance per gram of dye" shown in Table 1 is obtained by diluting each disperse dye with acetone to a concentration such that the maximum absorbance is in the range of 0.5 to 1.0. -VIS SPECTROTOPOMETER V-550, manufactured by JASCO Corporation), the absorbance of the diluted solution was measured, and the value obtained by multiplying the measured value by the dilution factor.

[Preparation of Black Ink 1]
The following dispersion was mixed at the following mass ratio to prepare a mixed dispersion 1.
Dispersion No. 1: 25.0 parts by mass Dispersion No. 4: 35.0 parts by mass Dispersion No. 9: 25.0 parts by weight Dispersion No. 16: 20.0 parts by mass

Ion-exchanged water, ethylene glycol (EG), glycerin (GLY) and polyethylene glycol # 600 (PEG # 600) as a solvent, BYK-348 (manufactured by BYK Chemie, BYK is a registered trademark of the company) as a silicone-based surfactant, and As an antifungal agent, Proxel GXL (manufactured by Arch Chemical Co., Ltd., Proxel is a registered trademark of the company) was mixed at the following mass ratio to prepare Diluent 1.
Ion-exchanged water: remainder (adjusted to the ratio shown in Table 2)
EG: 35.0 parts by mass GLY: 10.0 parts by mass PEG # 600: 4.0 parts by mass Surfactant: 0.1 parts by mass Antifungal agent: 0.2 parts by mass

  Diluent 2 was prepared in the same manner as Diluent 1 except that polypropylene glycol # 400 (PPG # 400) was mixed instead of PEG # 600. Diluent 3 was prepared in the same manner as Diluent 1 except that PEG # 600 was mixed with a compound represented by formula (3) (Liponic EG-1, manufactured by Lipo Chemicals).

  The diluted liquid 1 was added to the mixed dispersion liquid 1 previously mixed, stirred and mixed uniformly, and then filtered through a 1 μm mesh filter to obtain a black ink 1.

[Preparation of black ink 2 to 28]
Similarly, black inks 2 to 28 containing disperse dyes at mass ratios shown in Tables 2 to 5 were obtained.

  Tables 2 to 5 show the compositions of black inks 1 to 28 (each number is% by mass).

[Inkjet printing]
Inkjet printer Nassenger-V (made by Konica Minolta Co., Ltd., “Nassenger” is a registered trademark of Konica Minolta IJ Co., Ltd.) using the prepared black inks 1 to 28 at a printing rate of 100% duty at 540 dpi × 720 dpi. Then, a 15 cm × 15 cm rectangle was printed on the pretreated polyester fiber.

  As the pretreated polyester fiber, a polyester fiber having a thread thickness of 50d was immersed in an aqueous carboxymethylcellulose solution, and then drawn and dried. After printing, the fabric was subjected to HT steam treatment at 170 ° C. for 10 minutes, then washed with water, reduced and washed with a 0.2% aqueous hydrosulfite solution at 80 ° C., and then sufficiently washed with water and dried.

[Evaluation and measurement]
The following evaluations 1 to 3 and 6 were performed on the image samples thus obtained. The following evaluation 4 was performed about the injection property of the black inks 1-28. The following evaluation 5 was performed about the preservability of the black inks 1-28. Further, the maximum absorbance of black inks 1 to 28 was measured by the following method.

[Evaluation 1: Front and back color difference]
The color tone of the front and back of the image sample was visually evaluated according to the following criteria.
A: There is no difference between the color tone of the front surface and the color tone of the back surface.
○: Although there is a slight difference between the color tone of the front surface and the color tone of the back surface, there is little concern.
Δ: Although there is a difference between the color tone of the front surface and the color tone of the back surface, it is acceptable.
X: The difference between the color tone of the front surface and the color tone of the back surface is large and unacceptable.

[Evaluation 2: Edge blur]
The image edge portion of the image sample was visually evaluated according to the following criteria.
A: There is no bleeding at the edge part.
○: There is very little bleeding at the edge, but it is hardly noticed.
(Triangle | delta): Although there exists a blur in an edge part, it is permissible.
X: The blur of an edge part is large and is not accept | permitted.

[Evaluation 3: Maximum concentration]
The density of the image sample was evaluated with an X-RITE colorimeter and visually according to the following criteria.
(Double-circle): It can be evaluated that the sufficient density has come out to the image sample visually.
○: Although the numerical value of the colorimeter is slightly lower than the intended density, it can be judged by visual observation that a sufficient density is present in the image sample.
(Triangle | delta): Although it can judge that the density | concentration of an image sample is thin visually, it is permissible.
X: A sufficient density does not appear in the image sample even visually, which is not acceptable.

[Evaluation 4: Injection property]
In a low humidity environment of 25 ° C. and a relative humidity of 30%, each black ink was ejected from the inkjet printer Nassenger-V at a printing rate of 100% Duty. At the time of re-ejection, out of 256 nozzles, the number of non-ejecting nozzles, the number of nozzles with different ejection angles (curved nozzles), and whether or not micro splashes (splashes) other than main droplets occur When these occurred, it was determined that dry fixation occurred at the nozzle during the stop.
A: No non-ejection nozzles are generated after re-ejection, and there is no increase in splashing.
○: After re-ejection, about 1 to 2 bent nozzles are generated, but there is no influence on the image quality and there is no increase in splashing.
Δ: After re-ejection, about 1 to 2 non-ejecting nozzles are generated and splashing is slightly increased, but the image quality is acceptable with little influence on the image quality.
X: Three or more non-ejection nozzles were generated after re-ejection, splashing was conspicuous, and image quality deteriorated to an unacceptable level.

[Evaluation 5: Ink storage stability]
The storability of the ink was evaluated by comparing the Z-average particle diameter before and after storing the ink. Each black ink was stored at 50 ° C. for 1 week, and the Z-average particle size of the dispersed particles before and after storage was measured by a dynamic light scattering method using a Zetasizer 1000 manufactured by Malvern and compared.
○: Before and after storage, the change width of the Z-average particle diameter is less than 10 nm. E
Δ: Before and after storage, the change width of the Z-average particle diameter is more than 10 nm and less than 30 nm (allowable limit).
X: Before and after storage, the change width of the Z-average particle diameter exceeds 30 nm.

[Evaluation 6: Color difference between different light sources]
The image sample was visually observed under indoor fluorescent light (daylight color) and outdoors sunlight to evaluate whether there was a difference in the black color tone of the image sample.
○: There is no difference in color tone between the fluorescent light and sunlight.
Δ: Although there is a slight difference in color tone between fluorescent light and sunlight, it is acceptable.
X: There is a difference in color tone between the fluorescent light and the sunlight, and the redness looks relatively strong under the sunlight.

[Measurement of maximum absorbance]
The black inks 1 to 28 were each diluted with acetone, the collected spectrum of the visible part was measured with a spectrophotometer (UV-VIS SPECTROTOPOMETER V-550, manufactured by JASCO Corporation), and the absorbance value at the wavelength where the absorbance was maximized. The product was multiplied by the dilution factor to obtain the maximum absorbance. The dilution factor was such that the maximum absorbance measurement was between 0.5 and 1.0.

Table 6 shows the results of evaluations 1 to 6 performed on the image samples obtained by the black inks 1 to 28 and the maximum absorbance of the black inks 1 to 28.

  The black ink containing the red-type disperse dye and the blue-type disperse dye having the structure of the present invention had little color difference between the front and back and bleeding at the edge portion (black ink Nos. 1-4-4, 6-15). -4, 17-22, 25 and 26).

  When the black ink contains DB-60, which is a long wavelength blue disperse dye, it is difficult to produce a difference in color tone between fluorescent light and sunlight (comparison between black ink Nos. 21 and 22 and black ink). No. 25 and 26 are compared).

  When the total mass of the disperse dyes was 12% by mass or more based on the total mass of the black ink, the density of the image sample was increased (black ink No. 10 and 11).

  When the red disperse dye was DR-154 or DR-177, the density of the image sample could be adjusted to be higher (black ink No. 10, 11, 15-1 to 15-4, 17 to 22). .

  When the blue disperse dye is DB-79 or DB-165, the ejection properties from the ink jet head and the ink storage stability are increased (black ink Nos. 1-4-4, 6-15-4, 17 and 18).

  When the black ink contains at least one selected from polyethylene glycol having a molecular weight of 400 or more and 1000 or less, polypropylene glycol having a molecular weight of 400 or more and 1000 or less, and a compound represented by the formula (3), there is less color difference between the front and back sides. (Comparison between black ink Nos. 4-1 to 4-3 and 4-4, and comparison between black inks No. 15-1 to 15-3 and 15-4). Further, when the black ink contains polyethylene glycol having a molecular weight of 400 or more and 1000 or less, the color difference between the front and the back is further reduced (comparison between black ink No. 4-1 and 4-2 to 4-3, and black ink). No. 15-1 and comparison with 15-2 to 15-3).

  On the other hand, when the red disperse dye did not have the structure of the formula (1), the color difference between the front and back sides and the bleeding at the edge portion were large (black ink Nos. 5, 6, 16, 23 and 24). Further, when the blue disperse dye did not have the structure of the formula (2), the color difference between the front and back sides was large (black ink No. 27).

  When the black ink did not have a red disperse dye, the image sample did not have a sufficient density (black ink No. 27).

  The black ink of the present invention can be suitably used for image formation on a fabric by being discharged from an ink jet textile printing apparatus.

P fabric 2 transport mechanism 5 head carriage 6 warm air mechanism 6A fan 6B heating element 21 adhesive belt 22 support roller 23 transport roller 24 nip roller

Claims (10)

A water-based black ink for inkjet printing containing water and a disperse dye,
The disperse dye includes at least one selected from an orange disperse dye and a yellow disperse dye, a red disperse dye, and a blue disperse dye,
The red disperse dye is a compound represented by the formula (1),
The black ink, wherein the blue disperse dye is a compound represented by the formula (2).

(In the formula (1), R ₁ is a nitro group or a chloro group, R _2, if R ₁ is a nitro group when R ₁ is a hydrogen atom is chloro groups are chloro group, R ₃ Is a hydrogen atom or a methyl group, one of R ₄ is a cyanoethyl group, and the other of R ₄ is one selected from the group consisting of an ethyl group, a cyanoethyl group, an acetoxyethyl group, and an ethyl carbonate ethyl group .)

(In Formula (2), R ₅ is independently one selected from the group consisting of a cyano group, a nitro group, and a bromo group, provided that when either R ₅ is a nitro group, the other is When either R ₅ is a bromo group, the other is not a bromo group, R ₆ is a methyl group or an ethyl group, R ₇ is a hydrogen atom, methoxy group And R ₈ is independently one selected from the group consisting of a hydrogen atom, an ethyl group, a cyanoethyl group, a benzyl group, an acetoxyethyl group, and a methoxyethyl group. And when at least one of R ₈ is an acetoxyethyl group, R ₇ is an ethoxy group; otherwise, R ₇ is a hydrogen atom or a methoxy group.)   The black ink according to claim 1, wherein the maximum absorbance is 4000 or more.   The black ink according to claim 1, wherein the disperse dye further includes a blue disperse dye having a maximum absorption wavelength of 630 nm or more and 680 nm or less.   The black ink according to claim 1, wherein a mass of the disperse dye is 10% by mass or more and 15% by mass or less with respect to a mass of the whole black ink.   The black ink according to claim 1, wherein a mass of the disperse dye is 12% by mass or more and 15% by mass or less with respect to a mass of the whole black ink.   The red disperse dye is C.I. I. Disperse Red-154 or C.I. I. The black ink according to claim 1, wherein the black ink is Disperse Red-177.   The blue disperse dye is C.I. I. Disperse Blue-79 or C.I. I. It is Disperse Blue-165, The black ink of any one of Claims 1-6 characterized by the above-mentioned. It further contains at least one selected from polyethylene glycol having a molecular weight of 400 to 1000, polypropylene glycol having a molecular weight of 400 to 1000, and a compound represented by formula (3). The black ink according to any one of the above.

(In formula (3), R ₁₁ represents an ethylene glycol group or a polypropylene glycol group, and x, y, and z are all positive integers, and x + y + z = 3 to 30.)   9. An ink jet printing method for forming an image on a fabric with black ink, wherein the black ink is the black ink according to any one of claims 1 to 8. The ink-jet printing method according to claim 9, wherein the fabric is a fabric in which an image forming portion includes a polyester fiber.

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