JP2005248105A - Inkjet printing ink, inkjet printing ink set and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet printing ink, an inkjet printing ink set and an inkjet recording method stable against temperature fluctuation at the time of thermal color development. <P>SOLUTION: The inkjet printing ink set comprises at least a disperse dye, a dispersant, water and a water-soluble organic solvent and uses a plurality of inkjet inks of yellow, magenta, cyan or blue, and black, where the value obtained by dividing the minimum value by the maximum value of elution times in HPLC (high-performance liquid chromatography) of the main dispersed dye in the inkjet ink of each color is at least 0.6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet textile ink, an ink jet textile ink set, and an ink jet 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 as compared with 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.

  In dyeing using a disperse dye, heating color treatment is usually performed. Moreover, in the inkjet printing with respect to a fabric, pre-processing is normally performed. At this time, the heating temperature affects the color of the final print after color development.

  For this reason, as a method of suppressing the quality fluctuation in the color development processing, Patent Document 1 describes a method of defining a driving order and creating a stable black image with an acid dye. Patent Document 2 describes that a disperse dye is used to define a use ratio of a cyan dye and a blue dye to obtain an image that is stable with respect to changes in conditions with respect to heating.

However, with these methods, it was not possible to obtain a sufficiently stable color against temperature fluctuations during color development.
Japanese Patent Application Laid-Open No. 06-057651 Japanese Patent Laid-Open No. 08-035181

  The present invention has been made in view of the above circumstances, and provides an ink-jet printing ink, an ink-jet printing ink set, and an ink-jet recording method that are stable against temperature fluctuations during color development by heating.

  The above object of the present invention is achieved by the following configurations.

(Claim 1)
HPLC of the main disperse dye in each color ink-jet ink in an ink-jet printing ink set using a plurality of yellow, magenta, cyan, blue, and black ink-jet inks containing at least a disperse dye, a dispersant, water and a water-soluble organic solvent An ink-jet textile printing ink set, wherein a value obtained by dividing the minimum value of elution time (high performance liquid chromatography) by the maximum value is 0.6 or more.

(Claim 2)
The ink-jet textile ink set according to claim 1, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.7 or more.

(Claim 3)
The ink-jet printing ink set according to claim 2, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.8 or more.

(Claim 4)
The ink-jet printing ink set according to any one of claims 1 to 3, wherein the dissolved oxygen amount is 5 ppm or less.

(Claim 5)
In a black inkjet printing ink containing at least a plurality of disperse dyes, a dispersant, water, and a water-soluble organic solvent, a value obtained by dividing the minimum value of the HPLC elution time of the plurality of disperse dyes by the maximum value is 0.7 or more. An inkjet textile printing ink characterized by being.

(Claim 6)
6. The ink-jet printing ink according to claim 5, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.8 or more.

(Claim 7)
The inkjet textile printing ink according to claim 6, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.9 or more.

(Claim 8)
The ink-jet textile printing ink according to any one of claims 5 to 7, wherein the dissolved oxygen content is 5 ppm or less.

(Claim 9)
The inkjet printing ink set according to any one of claims 1 to 4, or the inkjet printing ink according to any one of claims 5 to 8, and an inkjet head having a nozzle diameter of 30 µm or less. Inkjet recording method.

(Claim 10)
The inkjet printing ink set according to any one of claims 1 to 4, or the inkjet printing ink according to any one of claims 5 to 8, and an inkjet head having a driving frequency of 20 kHz or more. Inkjet recording method.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an ink jet textile printing ink, an ink jet textile ink set, and an ink jet recording method that are stable against temperature fluctuations during color development by heating.

  As a result of diligent investigation focusing on the HPLC elution time of the disperse dye in the ink-jet ink in which the disperse dye is dispersed in water as a colorant, the present inventor has determined that the ink-jet printing ink has excellent stability against temperature fluctuations during color development (hereinafter referred to as “coloring agent”). The ink jet printing ink set and the ink jet recording method have been found. The detailed mechanism is under intensive study, but is presumed as follows.

  The moving speed of the dye in the pretreatment agent during color development affects the color stability. By limiting the difference in HPLC elution time of each dye used to a certain value or less, it is possible to design the moving speed to be equal and the permeation speed to the fiber to be equal, and to suppress color variation due to color development. It is thought that was made. In particular, in a black image, it is easy to perceive a difference in color due to the nature of the human eye, and thus color variation appears remarkably in a mixed color portion in which each color is mixed or in black ink using a plurality of dyes. Although the reason is not clear, the improvement effect is particularly great when printing with high speed and small droplets.

  The present invention will be described in detail below.

  In the present invention, the elution time of HPLC (High Performance Liquid Chromatography) can be measured using HPLC using a normal reverse phase column.

  The elution time of the HPLC of the present invention is measured with the following apparatus and measurement conditions.

Oven: GL Science Co., Ltd. model 556
Column: GL Science Co., Ltd., InertsilODS-2 (4.6 mm)
× 150 mm), particle size 5 μm
Injection volume: 20 μl
Pump: Hitachi, L6200
Flow rate: 0.8ml / min
Eluent: A (methanol) / B (0.1 mol / l acetic acid aqueous solution (pour with aqueous ammonia)
Adjust to H4)) Mixture
A80% to 100% Gradient for 20 minutes, A100% for 5 minutes Detector: Hitachi, UV-Vis detector L-4200
The material constituting the fabric used in the ink jet recording method (printing method) of the present invention is not particularly limited as long as it contains fibers that can be dyed with disperse dyes. Among them, polyester, acetate, triacetate, etc. Those containing these fibers are preferred. Among them, a fabric containing at least polyester fibers is particularly preferable. As the fabric, the above-described fibers may be any form such as a woven fabric, a knitted fabric, and a 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. Moreover, as a thickness of the thread | yarn which comprises the above fabrics, the range of 10-100d is preferable.

  In the case of the ink jet recording method of the present invention, in order to obtain a uniform dyed product, natural impurities (oils, waxes, pectic substances, natural dyes, etc.) adhering to the fabric fiber before the water-soluble polymer is pretreated on the fabric. ), It is desirable to wash away the residues (such as glue) and dirt of the chemical used in the fabric manufacturing process. As the cleaning agent used for cleaning, an alkali such as sodium hydroxide and sodium carbonate, a surfactant such as an anionic surfactant and a nonionic surfactant, an enzyme and the like are used.

  In the ink jet recording method of 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 a water-soluble polymer on a 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, sodium alginate, guar gum, tamarind gum, locust bean gum, gum arabic and other polysaccharides, 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, an anionic, cationic, amphoteric or nonionic surfactant is used. Anionic surfactants include higher alcohol sulfates, sulfonates of naphthalene derivatives, quaternary ammonium salts as cationic surfactants, imidazoline derivatives, etc. as amphoteric surfactants, nonionic surfactants, etc. Examples of the surfactant include polyoxyethylene alkyl ether, polyoxyethylene propylene block polymer, 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 that are pre-applied to the fabric are stable against high-temperature environments because they do not cause stains due to tarring and the like when ink-jet printing and coloring at high temperatures. Preferably there is. 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 washing after ink jet printing and color development at 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 printed on a fabric and simply left unattended, it does not dye well. Also, when printing on a long fabric for a long time, the fabric will come out endlessly, so the fabric printed on the floor will take up some space, and it is unsafe and will get dirty unexpectedly There is. 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 developing the original hue of ink by adhering / fixing the dye in the ink that is not sufficiently adsorbed / fixed to the fabric only by adhering the dye to the fabric surface after printing. . 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. In addition, the printed fabric may be heat-treated immediately according to the use, or may be heat-treated after a while, 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 the 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 the carrier include phenols such as o-phenylphenol, p-phenylphenol, methylnaphthalene, alkyl benzoate, alkyl salicylate, 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 around 100 ° C., such as 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, not only the fastness is lowered, but also the fabric is discolored. 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 a batch type using a liquid dyeing machine or the like, 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 nonionic dyes that do not have ionic water-soluble groups such as sulfonic acid and carboxy groups. They are finely powdered due to their low solubility in water, 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. In order to dye a fabric composed of a plurality of types of fibers by blending, union or the like, a color material other than the disperse dye, such as an acid dye or a direct dye, is mixed and used. It 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.

  When coloring is performed by high-temperature processing in textile printing using a disperse dye, it is preferable to select a disperse dye having good sublimation fastness so that the dye does not sublimate on a white background of a machine or fabric to cause contamination.

  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 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.), amines (for example, Ethanolamine, 2- (dimethylamino) ethanol, etc.), monohydric alcohols (eg, methanol, ethanol, butanol, etc.), polyhydric alcohol alkyl ethers (eg, 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.), acetonitrile etc. . The amount of the water-soluble organic solvent is preferably 10 to 60% by mass with respect to the total ink mass.

  An inorganic salt may be added to the ink in order to keep the viscosity of the ink and the dye stable and improve color development. 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, polyoxyethylene 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 ester, Fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, ® sugar 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, and by adding them in the range of 0.001 to 1.0% by mass with respect to the total amount of the ink, the surface of the ink 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 antiseptics and antifungal agents include aromatic halogen compounds (for example, Preventol CMK), methylene dithiocyanate, halogen-containing nitrogen sulfur compounds, 1,2-benzisothiazolin-3-one (for example, PROXEL GXL), and the like. 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 an optional additive 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. The average particle diameter can be determined by a commercially available particle size measuring instrument 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, formalin condensate of sodium creosote oil sulfonate (eg, Demol C), formalin condensate of sodium cresol sulfonate and sodium 2-naphthol-6-sulfonate, cresol sulfonic acid Formalin condensate of sodium, formalin condensate of sodium phenolsulfonate, formalin condensate of sodium β-naphtholsulfonate, formalin condensate of sodium β-naphthalenesulfonate (eg, demole N) and sodium naphtholsulfonate, lignin Examples thereof include sulfonates (for example, Vanillex RN), sodium paraffin sulfonate (for example, Efcol 214), copolymers of α-olefin and maleic anhydride (for example, Florene G-700), and the like.

  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.

  Preferable wetting agents include 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, so the dispersing agent and wetting agent may be used in addition to wetting ability, atomization ability and dispersion stability. It is necessary to select in consideration of foaming during dispersion, gelation of the dispersion, fluidity of the dispersion, and the like. Dispersants and wetting agents affect the dyeability, dyeing rate, leveling property, transferability, color tone, fastness, etc. of the fabric, and when coloring at high temperatures, It is preferable to select in consideration of non-uniform dyeing due to tarring of the agent. 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 to 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 fine bubbles to be generated. In particular, the dissolved oxygen is preferably 5 ppm or less. 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, deaeration may 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 adversely affects the physical properties of the ink. In this case, the dissolved gas in the ink can be efficiently removed.

  Dissolved oxygen can be measured at 25 ° C. and 1 atm using a commercially available dissolved oxygen concentration meter (DO-30A type manufactured by Toa Denpa Kogyo Co., Ltd.).

  The inkjet printing ink and inkjet printing ink set of the present invention are suitable for small droplet inkjet printing using an inkjet head having a nozzle diameter of 30 μm or less and high-speed inkjet printing using an inkjet head having a driving frequency of 20 kHz or more.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

Example 1
(Preparation of dispersion)
Dispersions Y1 to K1 were prepared from the following mixed liquid using a sand grinder. Dispersion stopped when the average particle size reached 200 nm.

Disperse dye (Dye is listed in Table 1) 25 parts Glycerin 25 parts Ion-exchanged water 25 parts Dispersant A: Sodium lignin sulfonate (Vanilex RN, manufactured by Nippon Paper Industries Co., Ltd.)
12 parts Dispersant B: Florene G-700 (manufactured by Kyoeisha Chemical Co., Ltd.) 3 parts Table 1 shows the elution time of each dye measured under the above HPLC conditions.

(Preparation of ink)
The above dispersions were mixed with the following composition, filtered and degassed with a 3 μm membrane filter to prepare corresponding inks Y1, M1 to M4, C1, and K1.

Dispersion 40 parts Ethylene glycol 40 parts Sodium diethylhexyl sulfosuccinate 0.1 part Proxel GXL (S) (manufactured by Avicia Co., Ltd.) 0.1 part Ion-exchanged water remainder Next, the above dispersions were mixed in the following composition Ink K1 was prepared by performing filtration and deaeration treatment with a 3 μm membrane filter.

Dispersion O1 15 parts Dispersion V1 25 parts Ethylene glycol 40 parts Diethylhexyl sulfosuccinate sodium 0.1 part Proxel GXL (S) (manufactured by Avicia Co., Ltd.) 0.1 part Ion-exchanged water remainder The prepared ink is gas-permeable. Ink was passed through a hollow fiber membrane (manufactured by Mitsubishi Rayon) and the outer surface side of the hollow fiber membrane was depressurized with a water flow aspirator to remove dissolved gas in the ink. In addition, after degassing, vacuum packing was performed to prevent air contamination.

  The prepared inks were combined as shown in Table 2 to prepare ink sets A to D.

(Create print 1)
Ink sets A to D were loaded into Konica Minolta Nassenger-II (manufactured by Konica Minolta), and an evaluation image was printed on a polyester pretreated cloth GB3931 (manufactured by Sumie Textile Co., Ltd.). In the evaluation image, when it is expressed as 100% when it is landed on all 300 dpi x 300 dpi in a single color, each color of yellow, magenta, cyan, and black is output by 50% in the same area at 300 dpi x 300 dpi. Images were used. dpi represents the number of dots per 2.54 cm.

(Creation of print 2)
Instead of Konica Minolta Nassenger-II, a head unit with a 720 dpi x 720 dpi resolution with four piezo heads with a drive frequency of 20 kHz and a nozzle diameter of 30 μm was adjusted so that the droplet speed of each color was 6 m / s. An evaluation image was printed on a polyester pretreated cloth GB3931 (manufactured by Sumie Textile Co., Ltd.) using a printer equipped with. In the evaluation image, when it is expressed as 100% when it is landed on all 720 dpi × 720 dpi in a single color, it is a four-color mixture that outputs each color of yellow, magenta, cyan, and black at 720 dpi × 720 dpi in the same area. Images were used.

  After printing, the mixture was left to dry at room temperature for 12 hours, and then heated and colored at 190 ° C., 195 ° C., and 200 ° C. for 20 minutes, respectively. After color development, after reducing and washing and drying naturally, the chromaticity is measured using X-rite 938. The color difference (color difference A) of 190 ° C. color development with respect to 195 ° C. color development and the 200 ° C. color development product with respect to 195 ° C. color development The color difference (color difference B) was determined. The results are shown in Table 3.

  It can be seen that the ink of the present invention is more stable with respect to the color development temperature difference than the ink of the comparative example.

Example 2
(Preparation of black ink)
The dispersion liquid produced in Example 1 was mixed with the following composition, filtered with a 3 μm membrane filter, degassed, and filled in a vacuum pack to prepare black inks KA to KD having a plurality of types of disperse dyes.

Material Amount added Dispersion 1 (types of dispersion are listed in Table 4) Table 4 dispersion 2 (types of dispersion are listed in Table 4) Table 4 dispersion 3 (types of dispersion are listed in Table 4) Described in Table 4) Ethylene glycol 20 parts Diethylhexyl sulfosuccinate sodium 0.1 part Proxel GXL (S) (manufactured by Avicia Co., Ltd.) 0.1 part Ion-exchanged water balance

  A black solid image was created, and the color difference (A) and the color difference (B) were determined in the same manner as in Example 1. The results are shown in Table 5.

  It can be seen that the ink of the present invention is more stable with respect to the color development temperature difference than the ink of the comparative example.

Claims (10)

HPLC of the main disperse dye in each color ink-jet ink in an ink-jet printing ink set using a plurality of yellow, magenta, cyan, blue, and black ink-jet inks containing at least a disperse dye, a dispersant, water and a water-soluble organic solvent An ink-jet textile printing ink set, wherein a value obtained by dividing the minimum value of elution time (high performance liquid chromatography) by the maximum value is 0.6 or more. The ink-jet textile ink set according to claim 1, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.7 or more. The ink-jet printing ink set according to claim 2, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.8 or more. The ink-jet printing ink set according to any one of claims 1 to 3, wherein the dissolved oxygen amount is 5 ppm or less. In a black inkjet printing ink containing at least a plurality of disperse dyes, a dispersant, water, and a water-soluble organic solvent, a value obtained by dividing the minimum value of the HPLC elution time of the plurality of disperse dyes by the maximum value is 0.7 or more. An inkjet textile printing ink characterized by being. 6. The ink-jet printing ink according to claim 5, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.8 or more. The inkjet textile printing ink according to claim 6, wherein a value obtained by dividing the minimum value of the elution time by the maximum value is 0.9 or more. The ink-jet textile printing ink according to any one of claims 5 to 7, wherein the dissolved oxygen content is 5 ppm or less. The inkjet printing ink set according to any one of claims 1 to 4, or the inkjet printing ink according to any one of claims 5 to 8, and an inkjet head having a nozzle diameter of 30 µm or less. Inkjet recording method. The inkjet printing ink set according to any one of claims 1 to 4, or the inkjet printing ink according to any one of claims 5 to 8, and an inkjet head having a driving frequency of 20 kHz or more. Inkjet recording method.