JP6745155B2 - Printing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a textile printing method in which a water-based ink is applied to a cloth by an inkjet method for printing.

In recent years, in the textile printing industry, the switching from the screen printing method to the ink jet method is rapidly progressing. In addition, garment printers that can directly print designs such as illustrations and photographs on cloth are rapidly becoming popular. When a pattern is printed on a cloth by an ink jet method, the cloth is heated and pressed by using a heating and pressing means such as a heat press or an iron, and the printed coloring material is dyed on the surface of the cloth.

When an ordinary cloth is printed by the ink jet method, the ink penetrates into the cloth, which causes a problem that the print density is insufficient. Therefore, it has been proposed to pretreat the cloth with various surface treatment agents (Patent Documents 1 to 5). When printing a colored fabric, white ink is usually applied for printing. However, in this case, the applied amount (volume) of the white ink is so large that pretreatment with a surface treatment agent is required to suppress the permeation of the white ink into the cloth (Patent Documents 6 to 9). ..

JP, 11-350365, A JP, 2003-027382, A Japanese Patent No. 4696578 JP, 2005-161043, A JP, 2009-030014, A JP, 2013-060513, A JP, 2013-151600, A JP, 2013-194122, A JP, 2014-148563, A

However, the pretreatment (surface treatment) of the cloth with the surface treatment agent is troublesome. Further, since such pretreatment is often performed manually, there is a problem that coating unevenness is likely to occur. Therefore, when a white ink is applied to a colored cloth for printing (printing), there has been a demand for a method that does not require a pretreatment step using a surface treatment agent, which has been performed so far.

The present invention has been made in view of such problems of the prior art, the problem is, concealing properties, washing fastness, and a white print excellent in friction fastness, surface It is an object of the present invention to provide a textile printing method which can be easily obtained without performing a pretreatment of a cloth with a treating agent.

That is, according to the present invention, the following textile printing method is provided.
[1] A textile printing method in which an aqueous white ink containing a white pigment is applied to a colored cloth by an inkjet method and printed, wherein the white ink contains a binder resin and the white pigment in the white ink. Further comprising a dispersant for dispersing, the dispersant is an AB type block copolymer having a hydrophobic polymer block and a hydrophilic polymer block, and the fabric is heated without pretreatment with a surface treatment agent. Then, the total discharge amount of the white ink is 2.4×10 ⁻² g/cm ² or more, and the discharge amount per one time is 8.0×10 ⁻³ g on the cloth heated to 50° C. or higher. /Cm ² or less, the textile printing method having a step of applying the number of times of printing at least 4 times.
[2] The textile printing method according to the above [1], which is a method for obtaining a textile having an OD value of 0.250 or less.
[ 3 ] The textile printing method according to [1] or [2] , wherein the content of the white pigment in the white ink is 14 to 24% by mass.
[ 4 ] The textile printing method according to any one of [1] to [3], wherein the white pigment contains rutile titanium oxide.

According to the present invention, there is provided a textile printing method capable of easily obtaining a white printed material having excellent hiding properties, fastness to washing, and fastness to rubbing without performing pretreatment of a fabric with a surface treatment agent. Can be provided.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. The textile printing method of the present invention is a method of printing by applying an aqueous white ink containing a white pigment to a colored cloth by an inkjet method. Then, there is a step of heating the cloth without pretreatment with the surface treatment agent and applying the white ink to the heated cloth in a plurality of times. The details will be described below.

(White ink application process)
The textile printing method of the present invention includes a step of heating a colored cloth without pretreatment with a surface treatment agent and applying the white ink to the heated cloth in a plurality of times (white ink applying step). The cloth can be placed on the heating surface of a heating device such as a surface heater and heated from the surface opposite to the printing surface (white ink application surface). The fabric is heated to 50° C. or higher, preferably 60° C. or higher, more preferably 80° C. or higher. If the heating temperature of the cloth is too low, the white ink applied to the cloth does not dry quickly, and a white printed material excellent in hiding power, fastness to washing and fastness to rubbing cannot be obtained. On the other hand, the heating temperature of the cloth is preferably 100° C. or lower. If the heating temperature of the cloth is too high, the cloth may be adversely affected, and heat may be easily transferred to the recording head that ejects the white ink, and the recording head may be easily clogged. In addition, if the heating temperature of the cloth is 50° C. or higher, it can be appropriately set according to the kind (material) of the cloth.

In the applying step, the total discharge amount is 2.4×10 ⁻² g/cm ² or more, preferably 2.5×10 ⁻² g/cm ² or more, and the discharge amount per time is 8.0×10 ^{−. The} white ink is applied to the fabric so as to be ³ g/cm ² or less, preferably 7.0×10 ⁻³ g/cm ² or less. Further, the white ink is applied to the cloth by dividing the number of printing times into four or more. That is, by reducing the amount of ink applied to the cloth by one discharge to thin the ink pile and applying the ink to the cloth in a plurality of times, heat is easily transferred to the white ink and the drying speed is increased. It is possible to suppress the penetration of ink into the cloth. If the number of times the white ink is divided and applied is too small, the white ink applied to the fabric does not dry quickly, and a white print excellent in hiding power, fastness to washing, and fastness to rubbing can be obtained. Can not. On the other hand, it is preferable that the white ink is divided and applied 10 times or less. If the white ink is divided and applied too many times, the operation may be complicated. It should be noted that if the white ink is divided and applied four times or more, it can be appropriately set according to the type (material) of the cloth and the like.

As the cloth to be printed, a cloth made of any natural fiber or synthetic fiber such as cotton, silk, wool, hemp, nylon, polyester, rayon can be used. Further, not only cloth, but also artificial leather or natural leather can be used as a material to be printed.

(Post-treatment process)
The textile printing method of the present invention preferably further comprises a post-treatment step of bringing the applied white ink into close contact with the cloth. In the post-treatment process, for example, a device capable of heating and pressing the fabric, such as a heat press, is used. The heating temperature is preferably set high within a range that does not damage the cloth and does not transfer a coloring material such as a dye coloring the cloth. Specifically, it may be heated at 120 to 200°C. The heating time may be appropriately set from the viewpoint of quality and workability, and may be, for example, about 1 to 3 minutes.

(Step of applying colored ink)
The textile printing method of the present invention preferably further has a step of further applying a coloring ink to the cloth to which the white ink has been applied. The method of applying the colored ink to the cloth is not particularly limited. For example, it can be applied by being ejected by an ordinary ink jet method, but by applying it by dividing it into plural times as in the case of the white ink, it is possible to obtain a printed material having more excellent reproducibility.

(White ink)
The white ink used in the textile printing method of the present invention is a water-based ink containing a white pigment. The white ink contains, in addition to the white pigment, water, a water-soluble organic solvent, a dispersant (pigment dispersant) for dispersing the white pigment in the ink, a binder resin, and the like.

[White pigment]
As the white pigment, either a white inorganic pigment or a white organic pigment can be used. Examples of white inorganic pigments include titanium oxide, zinc oxide, zinc sulfide, antimony oxide, and zirconium oxide. Examples of white organic pigments include white hollow resin particles and white polymer particles.

The color index (CI) of the white pigment is, for example, C.I. I. Pigment White 1 (basic lead carbonate), 4 (zinc oxide), 5 (mixture of zinc sulfide and barium sulfate), 6 (titanium oxide), 6:1 (titanium oxide containing other metal oxides), 7 (Zinc sulfide), 18 (calcium carbonate), 19 (clay), 20 (titanium mica), 21 (barium sulfate), 22 (natural barium sulfate), 23 (gloss white), 24 (alumina white), 25 (gypsum) ), 26 (magnesium oxide/silicon oxide), 27 (silica), 28 (anhydrous calcium silicate) and the like. Among them, surface-treated titanium oxide is preferable because it is excellent in color developability and hiding property and exhibits good dispersibility, and titanium oxide surface-treated with silica or alumina is more preferable.

Further, among the titanium oxides, rutile type titanium oxide, which is generally used as a white pigment, is preferable. As commercial products of rutile type titanium oxide, the following trade names are available: Tipaque (registered trademark) R-580, R-670, R-780, R-850, R-855, CR-60 (all manufactured by Ishihara Sangyo Co., Ltd. ); JR-301, JR-403, JR-405, JR-804, JR-806, JR-600A, JR-800 and the like (above, manufactured by Teika).

The content of the white pigment in the white ink is preferably 14 to 24% by mass, more preferably 16 to 20% by mass. By using the white ink in which the content of the white pigment is within the above range, it is possible to further reduce the applied amount (volume) of the ink, and it is possible to further facilitate the drying. When a white ink containing too little white pigment is used, the whiteness and the hiding property may decrease. On the other hand, if the content of the white pigment is too large, the ejection property of the white ink from the recording head may be deteriorated.

[Water-soluble organic solvent]
As the water-soluble organic solvent, an organic compound that is liquid at room temperature (25° C.) and soluble in water can be used. Specific examples of the water-soluble organic solvent include alkyl alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol and tert-butyl alcohol; Alkylene glycols containing an alkylene group having 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol and diethylene glycol; glycerin; Lower alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether and triethylene glycol monobutyl ether; N- Methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like can be mentioned.

These water-soluble organic solvents may be used alone or in combination of two or more. From the viewpoint of the drying property and the moisturizing effect, the content of the water-soluble organic solvent in the ink is preferably 5 to 70% by mass, and more preferably 10 to 60% by mass.

[water]
The content of water in the ink is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass from the viewpoint of adjusting the viscosity.

[Pigment dispersant]
As the pigment dispersant, a conventionally known pigment dispersant for inkjet ink can be used. The pigment dispersant may be a low molecular weight dispersant such as a surfactant or a polymer type dispersant (so-called polymer dispersant). As a polymer dispersant, acrylic, styrene, methacrylic, ester, amide, polyether, etc. higher order structures such as random copolymers, block copolymers, graft copolymers, gradient copolymers, star polymers, dendrimers, etc. A polymer having a can be used. Among them, a block copolymer having a hydrophobic polymer block and a hydrophilic polymer block composed of a monomer such as a methacrylate monomer (for example, methacrylic acid) is preferable, and an AB block copolymer is more preferable. Since the AB block copolymer is compatible with the binder resin, the dispersibility and storage stability of the white ink can be improved. The content of the pigment dispersant in the ink is preferably 5 to 100 parts by mass, and more preferably 10 to 60 parts by mass with respect to 100 parts by mass of the pigment.

[Binder resin]
As the binder resin, a conventionally known binder resin for inkjet ink can be used. By using the white ink containing the binder resin, the white ink can be strongly fixed to the cloth. As the binder resin, a random copolymer, a block copolymer, a graft copolymer, a gradient copolymer, a star polymer, a dendrimer, etc. such as an acrylic resin, a styrene resin, a methacrylic resin, an ester resin, an amide resin, and a polyether resin can be used. The content of the binder resin in the ink is preferably 2 to 30% by mass, more preferably 5 to 10% by mass.

[Alkaline component]
The white ink usually contains an alkaline component in order to neutralize the acidic groups of the pigment dispersant (polymer dispersant) and dissolve it in water, or to adjust the pH of the ink. Examples of the alkaline component include ammonia; aliphatic primary to tertiary amines such as monomethylamine, dimethylamine, and trimethylamine; monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, and methyl. Alcohol amines such as ethanolamine, dimethylethanolamine and methylisopropylamine; heterocyclic amines such as piperidine, morpholine and N-methylmorpholine; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide Can be mentioned. The content of the alkaline component in the ink is preferably an amount capable of neutralizing a part or all of the acidic groups of the polymer dispersant. Further, the pH of the white ink is preferably 7.0 to 10.0, and more preferably 7.5 to 9.5. When the pH of the white ink is less than 7.0, the pigment dispersant is likely to precipitate and the pigment may aggregate. On the other hand, if the pH of the white ink is more than 10.0, it may be difficult to handle because it becomes strongly alkaline.

[Other ingredients]
The white ink may appropriately contain, for example, a wetting agent (humectant), a surface tension adjusting agent (surfactant), a defoaming agent, a fixing agent, a pH adjusting agent, an antioxidant, an antiseptic agent and the like. Polyhydric alcohols can be used as the wetting agent. As the surface tension adjusting agent, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, a polymer surfactant, a silicone surfactant, and a fluorine surfactant. Surfactants such as

By blending the surfactant, the white ink can be more stably ejected from the ink jet recording head, and the penetration of the white ink into the cloth can be controlled more appropriately. The content of the surfactant in the ink is preferably 0.1 to 10% by mass. If the content of the surfactant is too large, the surface tension of the white ink may be lowered too much. For this reason, the permeation speed of the white ink into the fabric tends to be too high, and the hiding property and color developability may be insufficient.

The surface tension of the white ink is preferably 15 to 45 mN/m, more preferably 20 to 40 mN/m. As the surfactant, a fluorinated surfactant is preferable. Surfactants can usually cause ink foaming, ink repelling on the film surface, and pigment agglomeration. Therefore, it is preferable to keep the amount of the surfactant added to the ink small. The fluorine-based surfactant can reduce the surface tension of the ink with a small amount of addition as compared with other surfactants, so that the amount of addition can be suppressed to a low level. Examples of the fluorine-based surfactant include a perfluoroalkyl-based surfactant and a perfluoroalkenyl-based fluorine-based surfactant. Of these, perfluoroalkyl-based surfactants are preferable.

The content of the fluorine-based surfactant in the ink is preferably 10 to 10,000 ppm, and more preferably 20 to 5,000 ppm on a mass basis. If the content of the fluorine-based surfactant is less than 10 ppm, it may be difficult to sufficiently reduce the surface tension of the ink. On the other hand, when the content of the fluorine-based surfactant is more than 10,000 ppm, the surface tension of the ink may be too low and the ink may be easily foamed.

The white ink may contain an electrolyte in order to adjust the viscosity and pH. Examples of the electrolyte include sodium sulfate, potassium hydrogen phosphate, sodium citrate, potassium tartrate, sodium borate and the like. Further, sulfuric acid, nitric acid, acetic acid, sodium hydroxide, potassium hydroxide, ammonium hydroxide, triethanolamine and the like can be used as a thickening aid or pH adjusting agent for the ink.

By adding an antioxidant to the white ink, it is possible to prevent the oxidation of each component in the ink and improve the storage stability of the ink. Examples of the antioxidant include L-ascorbic acid, sodium L-ascorbate, sodium isoascorbate, potassium sulfite, sodium sulfite, sodium thiosulfate, sodium dithionite, and sodium pyrosulfite.

The white ink may contain a preservative in order to prevent spoilage and improve storage stability. Examples of the antiseptic agent include 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 1 , 2-benzisothiazolin-3-one and other isothiazolone preservatives; hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine and other triazine preservatives; 2-pyridinethiol sodium-1- Pyridine/quinoline preservatives such as oxide and 8-oxyquinoline; Dithiocarbamate preservatives such as sodium dimethyldithiocarbamate; 2,2-dibromo-3-nitrilopropionamide, 2-bromo-2-nitro-1,3 -Organobromine preservatives such as propanediol, 2,2-dibromo-2-nitroethanol, 1,2-dibromo-2,4-dicyanobutane; methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, sorbin Examples thereof include potassium acid salt, sodium dehydroacetate, and salicylic acid.

(Preparation of white ink)
The white ink can be prepared, for example, by preparing a pigment dispersion in which a white pigment is dispersed in an aqueous medium, and then mixing this pigment dispersion with each of the other components. The pigment dispersion can be prepared by mixing a white pigment, a pigment dispersant such as a polymer dispersant, and an aqueous medium such as water, pre-dispersing the mixture if necessary, and then performing main dispersion. The pre-dispersion can be performed using a general dissolver. In addition, it is preferable to pre-disperse using a high speed stirrer. As a high-speed stirrer, TK Homomixer, TK Robomix, TK Fillmix (above, product name of Primix Co., Ltd.); Clear Mix (product name of M Technique Co., Ltd.); Ultra Disper (product of Asada Steel Co., Ltd., product name) ) And the like are preferable.

The main dispersion includes, for example, a kneader, a two-roll roll, a three-roll roll; a kneading machine such as SS5 (manufactured by M Technique Co., Ltd.), Miracle KCK (manufactured by Asada Steel Co., Ltd.); an ultrasonic disperser. High-pressure homogenizers such as Microfluidizer (manufactured by Mizuho Industry Co., Ltd.); Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.); Starburst (manufactured by Sugino Machine Co., Ltd.); G-Smasher (manufactured by Rix Co.) , A product name) and the like can be used. Further, a ball mill using bead media such as glass or zirconia, a sand mill, a horizontal media mill disperser, a colloid mill and the like can also be used. As a medium used in the bead mill, a bead medium having a diameter of 1 mm or less is preferable, and a bead medium having a diameter of 0.5 mm or less is more preferable.

The dispersed particle diameter (median diameter D50) of the white pigment in the pigment dispersion is preferably 50 to 1,000 nm, more preferably 100 to 600 nm, and particularly preferably 200 to 500 nm. By using a pigment dispersion in which a white pigment having a median diameter D50 of 50 nm or more is used, it is possible to maintain the color developability in a better state. When the median diameter D50 is 1,000 nm or less, the fixability can be maintained in a better state, and the ink ejectability can be further improved. Furthermore, by setting the median diameter D50 to 100 nm or more, the hiding property and the color developability can be maintained in a better state. The viscosity of the white ink is preferably 2 to 30 mPa·s from the viewpoint of dischargeability.

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. Hereinafter, “part” and “%” are based on mass unless otherwise specified.

<Synthesis of AB type block copolymer (polymer dispersant)>
(Synthesis example 1)
In a separable flask (reactor) equipped with a stirrer, a back-flow condenser, a thermometer, and a nitrogen introduction tube, 125 parts of diethylene glycol dimethyl ether (diglyme), 3 parts of 2-iodo-2-cyanopropane, methyl methacrylate (MMA). 76 parts, 24 parts of acrylic acid (AA), 2.5 parts of azobisisobutyronitrile (AIBN), and 0.1 part of iodosuccinimide were added and stirred while flowing nitrogen. The reaction temperature was set to 75° C. and polymerization was performed for 3 hours. A part of the polymerization solution was sampled to measure the solid content concentration, which was 42.1%, and it was confirmed that most of the monomers were polymerized to form a polymer. The number average molecular weight (Mn) of the polymer measured by gel permeation chromatography (GPC) was 5,000, and the dispersity (PDI) was 1.42.

A mixture of 19 parts of benzyl methacrylate (BzMA) and 0.2 part of AIBN was added to the above polymerization solution, and polymerization was carried out at 75° C. for 3 hours. A part of the polymerization solution was sampled to measure the solid content concentration, which was 49.0%, and it was confirmed that most of the monomers were polymerized to form a polymer. The polymer had an Mn of 5,500 and a PDI of 1.44 as measured by GPC. The Mn of the polymer calculated from the UV absorption derived from the benzyl group was 5,400, and the PDI was 1.44. (1) Mn calculated from the visible region of GPC and Mn calculated from UV absorption are almost the same, and (2) Mn increased by polymerizing BzMA on the MMA/AA polymer block. Therefore, it is considered that the AB block copolymer in which the BzMA polymer block was bonded to the MMA/AA polymer block was formed. The acid value of the AB block copolymer was 154 mgKOH/g.

An aqueous solution of potassium hydroxide in an amount equivalent to neutralize carboxy groups in the polymer was added to the polymerization solution to neutralize the carboxy groups, and then pure water was added to obtain a polymer solution having a solid content concentration adjusted to 40% .. The obtained polymer solution was transparent and no polymer precipitation was observed. This means that the BzMA polymer block was also dissolved without being precipitated. The polymer solution was treated at 50° C. for 2 hours to decompose the iodine at the polymer terminal to obtain a polymer dispersant-1 solution.

<Synthesis of acrylic emulsion (binder resin)>
(Synthesis example 2)
After 2,000 parts of water was placed in a reactor similar to that used in Synthesis Example 1 and the atmosphere was replaced with nitrogen, the mixture was heated to 75°C. In a separate container, 200 parts of styrene, 700 parts of butyl acrylate, 90 parts of 2-ethylhexyl acrylate, 10 parts of tripropylene glycol dimethacrylate, and polyoxyethylene-1-(allyloxymethyl)alkyl ether ammonium sulfate (trade name) 20 parts of "AQUALON KH-10", manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., reactive surfactant) was added, and the mixture was homogenized to prepare a monomer mixture liquid. After adding 15 parts of potassium persulfate to the reactor while bubbling nitrogen, the monomer mixture was added dropwise using a dropping funnel for 3 hours and then aged for 3 hours to obtain a white emulsion. After the obtained emulsion was cooled, it was filtered with a 0.5 μm filter to remove coarse particles to obtain an emulsion of binder resin-1. The solid content concentration of the emulsion measured by sampling a part was 33.2%. In addition, the median diameter (D50) of the resin particles in the emulsion measured using a light scattering type particle diameter measuring device was 150 nm.

<Preparation of white pigment dispersion>
(Preparation example 1)
A mixture was obtained by mixing 250 parts of titanium oxide (trade name "CR-60", manufactured by Ishihara Sangyo Co., Ltd.), 112 parts of polymer dispersant, 48 parts of diethylene glycol monobutyl ether, and 190 parts of ion-exchanged water. The obtained mixture was put in a bead mill (trade name "DYNO-MILL KDL A type", manufactured by Shinmaru Enterprises Co., Ltd.), and zirconia beads having a diameter of 0.5 mm were filled at a filling rate of 80% and dispersed for a retention time of 2 minutes. Thus, a white pigment dispersion A was obtained. The solid content concentration of the obtained white pigment dispersion A was 52.7%, the viscosity at 25°C was 12.3 mPa·s, the pH at 25°C was 8.3, and the median diameter of the white pigment (titanium oxide) ( D50) was 253 nm.

<Preparation of white ink>
(Preparation example 2)
After mixing the components shown in Table 1, coarse particles were removed by filtering through a 5 μm membrane filter to obtain a white ink. In Table 1, "Surflon S-211" is a trade name of a surfactant (anionic fluorochemical surfactant) manufactured by Asahi Glass Co., Ltd.

<Print>
(Examples 1 to 5, Comparative Examples 1 to 4)
Using an inkjet printer (trade name "HEATJET MMP813H", manufactured by MasterMind Co., Ltd.), white ink is applied to a cotton fabric (100% ring-spun cotton) colored with a black dye under the conditions shown in Table 2. Then, solid printing was performed to obtain a printed matter. Using an automatic iron press machine (trade name "SATANAS PS-4634", manufactured by Europort Co.), the obtained printed matter is pressed under the conditions shown in Table 2 for 60 seconds, and the white ink is fixed on the cloth to print. Got

(Examples 6 to 8, Comparative Examples 5 to 8)
Except for using a polyester cloth (100% polyester) colored with a black dye and performing solid printing under the conditions shown in Table 3, the cases of Examples 1 to 5 and Comparative Examples 1 to 4 described above. A printed material was obtained in the same manner.

<Evaluation>
(OD value)
A reflection densitometer (trade name "i1", manufactured by X-Rite) was used to measure the OD value of the obtained print. The measurement results are shown in Tables 2 and 3. When the OD value is 0.250 or less, it can be determined that the hiding property is high.

(Washing fastness)
Using a small automatic washing machine (trade name "Hareharu Mini AKS-2.5GL", manufactured by Aluminum Co., Ltd.), the obtained print was washed 15 minutes x 3 times. Washing was performed under the condition of water:fabric=30:1 (mass ratio), using warm water of 40° C. containing 2 g/L of detergent. The product name "Attack" (manufactured by Kao) was used as the detergent. After dehydration, it was rinsed for 2 minutes, further dehydrated and dried. Using a discolored gray scale, the wash fastness was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
A: 4-5th grade, B: 3-4th grade, 4th grade, C: 2-3th grade, 3rd grade, D: 2nd grade or less

(Friction fastness)
A friction tester type II JIS L 0823 (rubbing tester for dyeing fastness test) was used to carry out a friction fastness test in accordance with JIS 0849. The tip of the friction element is covered with a 100% wet cotton cloth for friction (5 cm x 5 cm, Kanakin No. 3 (cotton)), and a test piece (22 cm x 3 cm) fixed on the test stand is placed every 10 cm. It rubbed 100 times back and forth at a speed of 30 times back and forth. Using a discolored and discolored gray scale, the rub fastness was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
A: 4-5th grade, B: 3-4th grade, 4th grade, C: 2-3th grade, 3rd grade, D: 2nd grade or less

Claims (4)

A textile printing method, wherein an aqueous white ink containing a white pigment is applied to a colored cloth by an inkjet method to print.
The white ink further contains a binder resin and a dispersant for dispersing the white pigment in the white ink,
The dispersant is an AB block copolymer having a hydrophobic polymer block and a hydrophilic polymer block,
The white ink is heated to 50° C. or higher on the cloth without pretreatment with a surface treatment agent, and the white ink is discharged at a total discharge amount of 2.4×10 ⁻² g/cm ² or more, and once. A textile printing method having a step of applying the printing operation by dividing the number of times of printing into 4 times or more so that the discharge amount per unit becomes 8.0×10 ⁻³ g/cm ² or less. The textile printing method according to claim 1, which is a method for obtaining a textile product having an OD value of 0.250 or less. The textile printing method according to claim 1 or 2 , wherein a content of the white pigment in the white ink is 14 to 24% by mass. The white pigment, textile printing method according to any one of claims 1 to 3, including rutile type titanium oxide.