JP2005263881A - Inkjet-printing ink set and method for inkjet-printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet-printing ink set by using a dispersion dyestuff excellent in preserving property and a method for inkjet-recording. <P>SOLUTION: This inkjet-printing ink set using in a plurality of the inkjet inks each contains at least a dispersion dyestuff, a dispersing agent, water and a water-soluble organic solvent, provided that a value obtained by dividing the containing rate of the water-soluble organic solvent having ≤40 dielectric constant used for the dispersion dyestuff showing the minimum log P value among the main dispersion dyestuffs in the inks by the containing rate of the water-soluble organic solvent having ≤40 dielectric constant used for the dispersion dyestuff showing the maximum log P value among the main dispersion dyestuffs in the inks is ≤1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  In recent years, in the field of textile printing, there has been a demand for an ink jet textile printing method that does not require a plate making process in order to shorten the delivery time and cope with small-lot and multi-product production. In textile printing, the type of dye used is limited depending on the type of fiber in the fabric, and disperse dyes are generally used for dyeing fibers such as polyester. When disperse dyes are used for ink-jet printing, in addition to the performances such as color tone and fastness, which are the criteria for selecting dyes for conventional printing, the ink-jet recording method discharges from fine nozzles, so fine particles Therefore, there are many restrictions on dye selection, such as dispersion suitability, prevention of nozzle clogging, and dispersion stability. In particular, an ink using a disperse dye as a colorant is a dispersion system in which colorant fine particles are dispersed in an aqueous medium, so that coarse particles are likely to be generated compared to a dissolved ink that is a complete solution, There are problems such as no clogging or sedimentation over time due to the generation of coarse particles due to aggregation during production or storage.

  Further, when a part of the ink in the ink set settles in a short period of time, the color variation is conspicuous and the color reproducibility is inferior. In particular, composite black tends to be problematic because the human eye is sensitive to neutral colors.

  A technology that averages the discharge performance of the recording head by changing the pigment dispersant (see, for example, Patent Document 1), and a polymerizable surfactant provides excellent dispersion stability, discharge stability, no bleeding, and color development. A technique of pigment ink (see, for example, Patent Document 2) capable of obtaining an image having excellent properties and abrasion resistance is disclosed.

However, these are investigations using pigment inks, and a disperse dye having low solubility has not been able to provide a satisfactory effect.
JP-A-8-224953 WO 01/96483 pamphlet

  In view of such circumstances, the present invention is to provide an ink-jet printing ink set using a disperse dye excellent in storage stability and an ink-jet recording method thereof.

  As a result of intensive studies, the present inventors have found an ink-jet printing ink set using a disperse dye excellent in storage stability and a recording method thereof.

  The present inventor has intensively studied, and in particular, in an inkjet ink in which a disperse dye is dispersed in water as a colorant, paying attention to the log P value of the disperse dye and the dielectric constant and content of the water-soluble organic solvent in the ink, I made a lot of improvements. The detailed mechanism is under intensive study, but is presumed as follows.

  In dispersed inks, if the wettability of the colorant surface is low, minute bubbles are likely to remain on the surface, and the aggregation of particles is accelerated through the remaining bubbles, causing sedimentation in a short period of time. I guess. It is difficult to sufficiently degas the fine bubbles on the surface by degassing using a normal degassing membrane module. Therefore, the pigment ink is modified on the surface of the pigment, or an organic solvent having excellent wettability is used. However, if an organic solvent with excellent wettability is used in the disperse dye ink, the solubility of the disperse dye increases and causes crystals to grow, which also causes sedimentation in a short period of time.

  Therefore, by adjusting the type and amount of the organic solvent in accordance with the characteristics of the dye in the ink, an ink set having excellent preservability and uniform sedimentation of each color can be obtained.

  In the present invention, the problem has been achieved by the following configuration.

(Claim 1)
Dielectric constant used for a disperse dye exhibiting the smallest log P value among the main disperse dyes in an ink-jet printing ink set using a plurality of ink-jet inks containing at least a disperse dye, a dispersant, water, and a water-soluble organic solvent The value obtained by dividing the content of the water-soluble organic solvent of 40 or less by the content of the water-soluble organic solvent having a dielectric constant of 40 or less used for the disperse dye exhibiting the maximum log P value among the main disperse dyes in the ink is 1 or less. An ink jet textile printing ink set characterized by

(Claim 2)
The ink-jet textile ink set according to claim 1, wherein the divided value is 0.6 or less.

(Claim 3)
The ink-jet textile ink set according to claim 1, wherein the divided value is 0.3 or less.

(Claim 4)
In an inkjet printing ink set using a plurality of inkjet inks containing at least a disperse dye, a dispersant, water, and a water-soluble organic solvent, the ink is used for dispersing a disperse dye exhibiting the minimum log P value among the main disperse dyes in the ink. The content of the water-soluble organic solvent having a dielectric constant of 40 or less was divided by the content of the water-soluble organic solvent having a dielectric constant of 40 or less used for dispersing the disperse dye having the maximum log P value among the main disperse dyes in the ink. An ink-jet textile ink set having a value of 1 or less.

(Claim 5)
The inkjet printing ink set according to claim 4, wherein the divided value is 0.6 or less.

(Claim 6)
The ink-jet textile ink set according to claim 4, wherein the divided value is 0.3 or less.

(Claim 7)
An ink jet recording method using an ink jet head having a nozzle diameter of 30 μm or less and the ink jet textile printing ink set according to claim 1.

(Claim 8)
An ink jet recording method comprising using an ink jet head having a driving frequency of 20 kHz or more and the ink jet textile ink set according to any one of claims 1 to 6.

  INDUSTRIAL APPLICABILITY According to the present invention, an ink jet textile ink set using a disperse dye excellent in storage stability and a recording method thereof can be provided.

  Hereinafter, the present invention will be described in detail.

  In claim 1 of the present invention, the content of the water-soluble organic solvent having a dielectric constant of 40 or less used for the disperse dye exhibiting the minimum log P value among the main disperse dyes in the ink is, for example, the dispersion of yellow ink Use multiple disperse dyes in yellow, magenta, cyan and black ink sets with dye Y1, Magenta ink disperse dye M1, M2, cyan ink disperse dye C1, black ink disperse dye K1 This is the main disperse dye if the amount of M1 in the magenta ink is quantitatively large, and if Y1 is the smallest by comparing the log P values of Y1, M1, C1, and K1, it is the minimum This is a disperse dye having a log P value of 2 and refers to the content of a water-soluble organic solvent having a dielectric constant of 40 or less. If the maximum logP value is M1, the content of the water-soluble organic solvent having a dielectric constant of 40 or less used in the dielectric dye used in the disperse dye showing the maximum logP value among the main disperse dyes in the ink. The water-soluble organic solvent content is 40 or less. In addition, as a dielectric constant, 10 is a minimum, and if lower than that, the solubility to water will fall and it is unpreferable.

  Claim 1 describes the water-soluble organic solvent used in the final ink, and claim 4 describes the water-soluble organic solvent used during dispersion. The lower limit of the divided values of claims 1 and 4 is zero.

  Note that “yellow, magenta, cyan, black”, “yellow, magenta, blue, black” and “yellow, magenta, turquoise, black” are used as specific names of the ink jet textile ink set.

  In the present invention, log P is a logarithmic value of the water / octanol distribution ratio. logP can be calculated by a fragment method, an atomic approach method, or the like. Exemplary software for calculating logP includes Cambridge Chem 3D Ultra 7.0. As hardware used for the calculation according to the present invention, the calculation can be executed sufficiently fast on a personal computer. As the logP value in the present invention, the ClogP value calculated from the dye structure using ChemDraw Ultra 7.0 by CambridgeSoft was used.

  The dielectric constant in the present invention is a value obtained at 25 ° C., and is described in, for example, “Solvent Handbook” Asahara Teruzo et al., Kodansha, “New Edition Solvent Pocketbook” edited by Organic Synthetic Chemistry Association, Ohm. Examples of water-soluble organic solvents having a dielectric constant of 40 or less include ethylene glycol (dielectric constant 37.7), diethylene glycol (dielectric constant 31.7), 1,2-ethanediol (dielectric constant 37.7), and the like.

  The material constituting the fabric used in the ink-jet printing method according to the present invention is not particularly limited as long as it contains fibers that can be dyed with disperse dyes, but includes fibers such as polyester, acetate, and triacetate. Those that do are preferred. Among them, a fabric containing at least polyester fibers is particularly preferable. As the fabric, the above-described fibers may be in any form such as woven fabric, knitted fabric, and non-woven fabric. Further, as the fabric that can be used in the present invention, it is preferable that the fiber that can be dyed with disperse dyes is 100%, but a mixed woven fabric with rayon, cotton, polyurethane, acrylic, nylon, wool, silk, etc. Alternatively, a blended nonwoven fabric or the like can also be used as a textile for printing. Further, the thickness of the yarn constituting the fabric as described above is preferably in the range of 10 to 100d.

  In the case of the inkjet printing method according to the present invention, in order to obtain a uniform dyed product, natural impurities (oils, waxes, pectic substances, natural pigments) attached to the fabric fibers before the water-soluble polymers are pretreated on the fabric. Etc.), it is desirable to wash away the residues (such as glue) and dirt of the chemicals used in the fabric manufacturing process. As cleaning agents used for cleaning, alkalis such as sodium hydroxide and sodium carbonate, surfactants such as anionic surfactants and nonionic surfactants, enzymes and the like are used.

  In the inkjet textile printing method according to the present invention, it is preferable to apply a pretreatment agent by a pad method, a coating method, a spray method or the like (pretreatment step) in order to prevent bleeding. Thereafter, an image is formed on the fabric containing fibers that can be dyed with a disperse dye by the ink jet recording method using the ink having the above-described configuration (ink application step), and then the ink is applied. The fabric is heat-treated (coloring step), and the heat-treated fabric is washed (washing step) to complete printing on the fabric and obtain a printed product.

  The pretreatment is not particularly limited as long as a method suitable for the fiber material and ink is appropriately selected from known methods such as pretreatment of water-soluble polymers on the fabric. For example, it is used for a fabric provided with 0.2 to 50% by mass of at least one substance selected from the group consisting of water-soluble metal salts, polycation compounds, water-soluble polymers, surfactants and water repellents. Therefore, it is possible to prevent a high degree of bleeding, and a high-definition image can be printed on a fabric.

  The example of the specific water-soluble polymer used for pre-processing is given.

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

  As the surfactant, for example, anionic, cationic, amphoteric, and nonionic surfactants are used. Typically, anionic surfactants include higher alcohol sulfates and sulfonates of naphthalene derivatives. Quaternary ammonium salt and the like as ionic surfactant; imidazoline derivative and the like as amphoteric surfactant; polyoxyethylene alkyl ether and polyoxyethylene propylene block polymer as nonionic surfactant Sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, ethylene oxide adduct of acetylene alcohol, and the like.

  Examples of the water repellent include silicon, fluorine-based and wax-based ones. These water-soluble polymers and surfactants previously imparted to the fabric are stable against high-temperature environments because they do not cause dirt due to tarring or the like when ink-jet printing and coloring at high temperatures. It is preferable. Further, these water-soluble polymers and surfactants that are previously imparted to the fabric are preferably those that can be easily removed from the fabric by a washing treatment after ink-jet printing and color development at a high temperature.

  In the ink jet textile printing method for printing on a cloth, it is desirable to wind up the printed cloth after emitting the ink, develop a color by heating, and wash and dry the cloth. In ink jet textile printing, ink is not printed well just by printing it on a cloth and leaving it alone. In addition, when printing on a long fabric for a long time, the fabric comes out endlessly, so the printed fabric overlaps the floor etc., and it is unsafe and unexpectedly dirty. May end up. Therefore, it is necessary to perform a winding operation after printing. During this operation, a medium not related to printing, such as paper, cloth, or vinyl, may be sandwiched between the cloth and the cloth. However, it is not always necessary to wind up when cutting in the middle or short fabric.

  The color development step is a step of expressing the original hue of the ink by adhering to and fixing the dye in the ink that has only adhered to the fabric surface after printing and has not been sufficiently adsorbed and fixed to the fabric. As the method, steaming by steam, baking by dry heat, thermosol, HT steamer by superheated steam, HP steamer by pressurized steam, etc. are used. They are appropriately selected depending on the material to be printed, ink, and the like. Further, the printed fabric may be immediately heat-treated or may be heat-treated after a while and may be dried and colored according to the intended use, and any method may be used in the present invention.

  When dyeing with a disperse dye, a carrier may be used in addition to a method of coloring at a high temperature. The compound used as a carrier is preferably a compound having characteristics such as large dyeing acceleration, simple use, stable, low burden on human body and environment, easy removal from the fiber, and no influence on dye fastness.

  Examples of carriers include o-phenylphenol, p-phenylphenol, methylnaphthalene, alkyl benzoate, alkyl salicylate, phenols such as chlorobenzene and diphenyl, ethers, organic acids, hydrocarbons and the like. These promote the swelling and plasticization of difficult-to-dye fibers that are difficult to dye at temperatures around 100 ° C. like polyester, and make it easier for disperse dyes to enter the fibers. The carrier may be preliminarily adsorbed on the fibers of the fabric used for inkjet printing, or may be included in the inkjet ink.

  A cleaning step is necessary after the heat treatment. This is because a dye that has not participated in the dyeing remains, resulting in poor color stability and low fastness. It is also necessary to remove the pretreatment product applied to the fabric. If left as it is, the fabric is discolored as well as a decrease in fastness. Therefore, cleaning according to the object to be removed and the purpose is essential. The method is selected according to the material and ink to be printed. For example, in the case of polyester, treatment is generally performed with a mixed solution of caustic soda, a surfactant, and hydrosulfite. The method is usually carried out in a continuous type such as an open soaper or in a batch type using a liquid dyeing machine, and any method may be used in the present invention.

  Drying is required after washing. After the washed fabric is squeezed or dehydrated, it is dried or dried using a dryer, heat roll, iron or the like.

  A disperse dye is used as the coloring material in the present invention. Disperse dyes are non-ionic dyes that do not have ionic water-soluble groups such as sulfonic acid and carboxy groups. They have a low solubility in water and are finely powdered, and are usually dispersed in water with a dispersant to dye synthetic fibers. Used for. Unlike pigments, it is soluble in organic solvents such as acetone and dimethylformamide. Moreover, it is possible to diffuse and color in a synthetic fiber in a molecular form.

  The present invention relates to a disperse dye, and in order to dye a fabric composed of a plurality of types of fibers by blending, union, etc., a color material other than the disperse dye, such as an acid dye or a direct dye, is used by mixing. Is also possible.

  Specific compounds of disperse dyes preferable for the present invention are shown below. However, it is not limited to the compound illustrated to these.

C. I. Disperse Yellow 3, 4, 5, 7, 9, 13, 23, 24, 30, 33, 34, 42, 44, 49, 50, 51, 54, 56, 58, 60, 63, 64, 66, 68, 71, 74, 76, 79, 82, 83, 85, 86, 88, 90, 91, 93, 98, 99, 100, 104, 108, 114, 116, 118, 119, 122, 124, 126, 135, 140, 141, 149, 160, 162, 163, 164, 165, 179, 180, 182, 183, 184, 186, 192, 198, 199, 202, 204, 210, 211, 215, 216, 218, 224, 227, 231, 232
C. I. Disperse Orange 1, 3, 5, 7, 11, 13, 17, 20, 21, 25, 29, 30, 31, 32, 33, 37, 38, 42, 43, 44, 45, 46, 47, 48, 49, 50, 53, 54, 55, 56, 57, 58, 59, 61, 66, 71, 73, 76, 78, 80, 89, 90, 91, 93, 96, 97, 119, 127, 130, 139, 142
C. I. Disperse Red 1, 4, 5, 7, 11, 12, 13, 15, 17, 27, 43, 44, 50, 52, 53, 54, 55, 56, 58, 59, 60, 65, 72, 73, 74, 75, 76, 78, 81, 82, 86, 88, 90, 91, 92, 93, 96, 103, 105, 106, 107, 108, 110, 111, 113, 117, 118, 121, 122, 126, 127, 128, 131, 132, 134, 135, 137, 143, 145, 146, 151, 152, 153, 154, 157, 159, 164, 167, 169, 177, 179, 181, 183, 184, 185, 188, 189, 190, 191, 192, 200, 201, 202, 203, 205, 206, 207, 210, 221, 224, 22 , 227,229,239,240,257,258,277,278,279,281,288,298,302,303,310,311,312,320,324,328
C. I. Disperse Violet 1, 4, 8, 23, 26, 27, 28, 31, 33, 35, 36, 38, 40, 43, 46, 48, 50, 51, 52, 56, 57, 59, 61, 63, 69, 77
C. I. Disperse Green 9
C. I. Disperse Brown 1, 2, 4, 9, 13, 19
C. I. Disperse Blue 3, 7, 9, 14, 16, 19, 20, 26, 27, 35, 43, 44, 54, 55, 56, 58, 60, 62, 64, 71, 72, 73, 75, 79, 81, 82, 83, 87, 91, 93, 94, 95, 96, 102, 106, 108, 112, 113, 115, 118, 120, 122, 125, 128, 130, 139, 141, 142, 143, 146, 148, 149, 153, 154, 158, 165, 167, 171, 173, 174, 176, 181, 183, 185, 186, 187, 189, 197, 198, 200, 201, 205, 207, 211, 214, 224, 225, 257, 259, 267, 268, 270, 284, 285, 287, 288, 291, 293, 295, 97,301,315,330,333
C. I. Disperse Black 1, 3, 10, 24 etc. are mentioned.

  In the case of color development by high-temperature processing in textile printing using a disperse dye, it is preferable to select a disperse dye having good sublimation fastness, because the dye does not cause sublimation on the white background of a machine or fabric.

  As content of a disperse dye, 0.1-20 mass% is preferable, and 0.2-13 mass% is more preferable. The disperse dye may be used as a commercial product, but it is preferable to carry out a purification treatment. As a purification method, a known recrystallization method, washing or the like can be used. The organic solvent used in the purification method and purification treatment is preferably selected as appropriate according to the type of dye.

  Examples of the water-soluble organic solvent according to the present invention include polyhydric alcohols (for example, ethylene glycol, glycerin, 2-ethyl-2- (hydroxymethyl) -1,3-propanediol, tetraethylene glycol, triethylene glycol). , Tripropylene glycol, 1,2,4-butanetriol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, 1,6-hexanediol, 1,2-hexanediol, 1,5-pentanediol, 1,2 -Pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 3-methyl-1,3-butanediol, 2-methyl-1,3-propanediol, etc.), amino (For example, ethanolamine, 2- (dimethylamino) ethanol, etc.), monohydric alcohols (for example, methanol, ethanol, butanol, etc.), polyhydric alcohol alkyl ethers (for example, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, Triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, etc.), 2,2'-thiodiethanol, amides (For example, N, N-dimethylformamide, etc.), heterocyclic rings (2-pyrrolidone, etc.), acetonite Le, and the like.

  The amount of the water-soluble organic solvent is preferably 10 to 60% by mass with respect to the total ink mass.

  In order to improve the color development in order to keep the viscosity and dye of the ink stable, an inorganic salt may be added to the ink. Examples of inorganic salts include sodium chloride, sodium sulfate, magnesium chloride, magnesium sulfide and the like. When implementing this invention, it is not limited to these.

  As the surfactant, any of cationic, anionic, amphoteric and nonionic can be used. Examples of the cationic surfactant include aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like. Examples of anionic surfactants include fatty acid soap, N-acyl-N-methylglycine salt, N-acyl-N-methyl-β-alanine salt, N-acyl glutamate, alkyl ether carboxylate, acylated peptide , Alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, dialkyl sulfosuccinate, alkyl sulfoacetate, α-olefin sulfonate, N-acylmethyl taurine, sulfated oil, higher alcohol sulfate Salts, secondary higher alcohol sulfates, alkyl ether sulfates, secondary higher alcohol ethoxy sulfates, polyoxyethylene alkylphenyl ether sulfates, monoglyculates, fatty acid alkylolamide sulfates, alkyl ether phosphates Salt, alkyl phosphate ester salt and the like. Examples of amphoteric surfactants include carboxybetaine type, sulfobetaine type, aminocarboxylate, imidazolinium betaine and the like. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkylphenyl ether (eg, Emulgen 911), polyoxyethylene sterol ether, polyoxyethylene lanolin derivative, polyoxy Ethylene polyoxypropylene alkyl ether (for example, Newpol PE-62), polyoxyethylene glycerin fatty acid ester, polyoxyethylene castor oil, hydrogenated castor oil, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyethylene glycol fatty acid Esters, fatty acid monoglycerides, polyglycerol fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters , Sucrose fatty acid esters, fatty acid alkanolamides, polyoxyethylene fatty acid amides, polyoxyethylene alkyl amines, alkyl amine oxides, acetylene glycol, acetylene alcohol, and the like. The present invention is not limited to these.

  When these surfactants are used, they can be used singly or as a mixture of two or more kinds. By adding 0.001 to 1.0% by mass with respect to the total amount of ink, the surface of the ink can be used. The tension can be arbitrarily adjusted, which is preferable.

  In order to maintain the long-term storage stability of the ink, an antiseptic and an antifungal agent may be added to the ink. Examples of the antiseptic and antifungal agent include aromatic halogen compounds (for example, Preventol CMK), methylene dithiocyanate, halogen-containing nitrogen sulfur compounds, 1,2-benzisothiazolin-3-one (for example, PROXEL GXL), and the like. It is done. The present invention is not limited to these.

  In the case of a water-insoluble dye, the ink used in the present invention can be dispersed by mixing a dye, a dispersing agent, a wetting agent, a medium, and optional additives, and using a dispersing machine. As the disperser, a conventionally known ball mill, sand mill, line mill, high-pressure homogenizer, or the like can be used.

  The particle size of the disperse dye is preferably 300 nm or less as the average particle size and 900 nm or less as the maximum particle size. This is because when the average particle size and the maximum particle size are large, clogging is likely to occur in an ink jet printing method in which light is emitted from a fine nozzle, and stable emission is not possible. In the present invention, the nozzle diameter is 30 μm or less and is preferably 10 μm or more because the droplet volume becomes too small and is affected by the air flow. The average particle size can be determined by a commercially available particle size measuring device using a light scattering method, an electrophoresis method, a laser Doppler method or the like. Specific examples of the particle diameter measuring apparatus include Zetar Sizer 1000 manufactured by Malvern.

  Dispersants preferably used in the present invention include, for example, a formalin condensate of sodium creosote oil sulfonate (eg, demole C), a formalin condensate of sodium cresol sulfonate and sodium 2-naphthol-6-sulfonate, and cresol sulfone. Formalin condensate of sodium sulfonate, formalin condensate of sodium phenol sulfonate, formalin condensate of sodium β-naphthol sulfonate, formalin condensate of sodium β-naphthalene sulfonate (eg, demole N) and sodium β-naphthol sulfonate , Lignin sulfonate (for example, Vanillex RN), sodium paraffin sulfonate (for example, Efcol 214), a copolymer of α-olefin and maleic anhydride (for example, Florene G-700), and the like. It is.

  The amount of the dispersant used is preferably 20 to 200% by mass with respect to the disperse dye. If the amount of the dispersant is small, the formation of fine particles and the dispersion stability are inferior, and if the amount of the dispersant is large, the formation of fine particles and the dispersion stability is inferior and the viscosity becomes high. These dispersants may be used alone or in combination.

  Preferred wetting agents for dispersion according to the present invention are sodium dodecylbenzenesulfonate, sodium 2-ethylhexylsulfosuccinate, sodium alkylnaphthalenesulfonate, ethylene oxide adduct of phenol, ethylene oxide adduct of acetylenediol, and the like. .

  Depending on the structure of the disperse dye used, foaming, gelation, and fluidity may be deteriorated during dispersion. Dispersants and wetting agents are dispersed in addition to wetting ability, atomization ability and dispersion stability. It is necessary to select in consideration of foaming at the time, gelation of the dispersion, fluidity of the dispersion, and the like. Dispersants and wetting agents affect the dyeability, dyeing rate, leveling, transferability, color tone, fastness, etc. on fabrics, and when developing colors at high temperatures, dispersants and wetting agents It is preferable to select in consideration of non-uniform dyeing due to tarring. Since there is no dispersant that satisfies all of the above requirements, it is necessary to select an optimal dispersant according to the dye to be dispersed and add an antifoaming agent or the like as necessary.

  It is preferable that a dyeing assistant is included in the inkjet ink for printing used for dyeing by the high-temperature steaming method or the fabric used for printing. The dyeing aid has the effect of making eutectic mixture with the water condensed in the form of cloth when steaming the printed fabric, reducing the amount of water that re-evaporates, and shortening the heating time. Further, this eutectic mixture has the effect of dissolving the dye on the fiber and promoting the diffusion rate of the dye into the fiber. Urea is mentioned as a dyeing assistant.

  In inks used in printers and the like, dissolved gas contained in the ink causes the resolution and clarity of the printed matter to be impaired, and causes generation of fine bubbles. Methods for degassing dissolved gas from the ink are roughly divided into a method of degassing by a physical method such as boiling or decompression, and a chemical method of mixing an absorbent into the ink. In the present invention, degassing can be performed by any means. In particular, the method of permeating and removing dissolved gas in the ink by passing the ink through the gas-permeable hollow fiber membrane and reducing the pressure on the outer surface side of the hollow fiber membrane has an adverse effect on the physical properties of the ink. This is preferable because the dissolved gas in the ink can be efficiently removed without giving.

  In the ink jet recording according to the present invention, one characteristic is that the driving frequency of the ink jet recording head is 20 kHz or more, preferably 30 kHz or more, particularly preferably 35 to 100 kHz, and the driving frequency of the ink jet recording head. By setting the above to the conditions specified above, high-speed printing can be realized.

  Examples of the present invention will be specifically described below, but the embodiments of the present invention are not limited thereto.

Example 1
<Preparation of dispersion>
Dispersions Y1 to V1 were prepared from the following mixed liquid using a sand grinder. Dispersion stopped when the average particle size reached 200 nm.

Disperse dye (described in Table 1) 25 parts Water-soluble organic solvent Amount described in Table 1 Dispersant: Sodium lignin sulfonate (Vanilex RN, manufactured by Nippon Paper Industries Co., Ltd.)
12 parts Remaining ion-exchanged water

[Preparation of ink]
Further, each dispersion was added in the amount shown in Table 2, so that the water-soluble organic solvent had the composition shown in Table 2, and sodium diethylhexylsulfosuccinate and Proxel GXL (S) (manufactured by Avicia Co., Ltd.) each 0.1 % Was added, and the remainder was mixed using ion-exchanged water. Thereafter, filtration and deaeration treatment were performed with a 3 μm membrane filter to obtain corresponding inks Y1 to K1.

  In addition, the prepared ink was passed through a gas-permeable hollow fiber membrane (manufactured by Mitsubishi Rayon Co., Ltd.), and the outer surface side of the hollow fiber membrane was depressurized with a water aspirator. Dissolved gas was removed. In addition, after degassing, vacuum packing was performed to prevent air contamination.

  Table 3 shows the content of the water-soluble organic solvent having a dielectric constant of 40 or less used for the disperse dye having the smallest log P value among the main disperse dyes in the ink. The value (content ratio) divided by the content of the water-soluble organic solvent having a dielectric constant of 40 or less used in the disperse dye showing the value is shown.

[Implementation of Print Test 1]
Konica Minolta (Konica Minolta (4) uses a piezo head having a drive frequency of 20 kHz and a nozzle diameter of 30 μm, and a head unit in which the droplet speed of each color is adjusted to 6 m / s. An evaluation image was printed on the pre-treated cloth A manufactured by Japan under the condition of 25 ° C. In the evaluation image, yellow, magenta, cyan, black when 720 dpi × 720 dpi (dpi represents the number of dots per inch, that is, 2.54 cm) is assumed to be 100%. A four-color mixed solid image in which each color was output to the same area by 25% was used.

  Printing was carried out immediately after the ink was mounted, and then left for 2 weeks to perform printing again. Each chromaticity at this time was measured using an X-rite 938 to obtain a color difference ΔE.

[Implementation of print test 2]
A print test 2 was conducted in the same manner as the print test 1 except that the ink set shown in Table 3 was stored in a thermostat at 50 ° C for 4 weeks.

  From Table 4, it can be seen that the ink of the present invention has less color variation and superior storage stability compared to the ink of the comparative example.

Claims (8)

Dielectric constant used for a disperse dye exhibiting the minimum logP value among the main disperse dyes in an ink in an ink-jet printing ink set using a plurality of ink-jet inks containing at least a disperse dye, a dispersant, water, and a water-soluble organic solvent The value obtained by dividing the content of the water-soluble organic solvent of 40 or less by the content of the water-soluble organic solvent having a dielectric constant of 40 or less used for the disperse dye exhibiting the maximum log P value among the main disperse dyes in the ink is 1 or less. An ink jet textile printing ink set characterized by The ink-jet textile ink set according to claim 1, wherein the divided value is 0.6 or less. The ink-jet textile ink set according to claim 1, wherein the divided value is 0.3 or less. In an inkjet printing ink set using a plurality of inkjet inks containing at least a disperse dye, a dispersant, water, and a water-soluble organic solvent, the ink is used for dispersing a disperse dye exhibiting the minimum log P value among the main disperse dyes in the ink. The content of the water-soluble organic solvent having a dielectric constant of 40 or less was divided by the content of the water-soluble organic solvent having a dielectric constant of 40 or less used for dispersing the disperse dye having the maximum log P value among the main disperse dyes in the ink. An ink-jet textile ink set having a value of 1 or less. The inkjet printing ink set according to claim 4, wherein the divided value is 0.6 or less. The ink-jet textile ink set according to claim 4, wherein the divided value is 0.3 or less. An ink jet recording method using an ink jet head having a nozzle diameter of 30 μm or less and the ink jet textile printing ink set according to claim 1. An ink jet recording method comprising using an ink jet head having a driving frequency of 20 kHz or more and the ink jet textile ink set according to any one of claims 1 to 6.