Method for manufacturing aqueous pigment inks and printed materials for inkjet textile printing.

Abstract

To provide aqueous pigment ink for printing inkjet for manufacturing a printed matter which is excellent in washing fastness.SOLUTION: Aqueous pigment ink for printing inkjet contains a pigment, a water-dispersible resin, water, and a water-soluble organic solvent, wherein a weight change rate before and after immersion of an ink film manufactured by drying the aqueous pigment ink for printing inkjet in hot water of 50°C is 20% or less, and film elongation after immersion in hot water of 50°C is 50% or more and 300% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] Embodiments of the present invention relate to aqueous pigment inks for textile inkjet printing and methods for producing printed materials. [Background technology]

[0002] Direct inkjet printing using pigment inks is attracting attention as a method for printing images such as letters, pictures, and patterns onto fabrics such as woven, knitted, and nonwoven materials. In textile printing, both vibrant color reproduction and wash fastness are required.

[0003] Regarding technologies for improving wash fastness, Patent Document 1 discloses a method using an ink and a coating liquid separate from the ink, and Patent Document 2 discloses an ink containing a high-elongation resin with a breaking elongation of 1200 to 1800% and a small amount of crosslinking agent. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2013-71957 [Patent Document 2] Japanese Patent Publication No. 2019-31611 [Overview of the project] [Problems that the invention aims to solve]

[0005] One embodiment of the present invention aims to provide an aqueous pigment ink for inkjet printing for producing printed materials with excellent wash fastness. [Means for solving the problem]

[0006] One embodiment of the present invention relates to an aqueous pigment ink for textile inkjet printing, comprising a pigment, a water-dispersible resin, water, and a water-soluble organic solvent, wherein the weight change rate of the ink film prepared by drying the aqueous pigment ink for textile inkjet printing is 20% or less before and after immersion in 50°C hot water, and the film elongation after immersion in 50°C hot water is 50% or more and 300% or less. Another embodiment of the present invention relates to a method for producing a printed material, which includes applying the aqueous pigment ink for printed inkjet printing of the above-described embodiment to a fabric by an inkjet method. [Effects of the Invention]

[0007] According to one embodiment of the present invention, an aqueous pigment ink for inkjet printing can be provided for manufacturing printed materials with excellent wash fastness. [Modes for carrying out the invention]

[0008] One embodiment of the present invention will be described in detail below, but it goes without saying that the present invention is not limited to these embodiments and various modifications and changes may be made.

[0009] One embodiment of the aqueous pigment ink for textile printing inkjet is an aqueous pigment ink for textile printing inkjet comprising a pigment, a water-dispersible resin, water, and a water-soluble organic solvent, wherein the weight change rate of the ink film prepared by drying the aqueous pigment ink for textile printing inkjet is 20% or less before and after immersion in 50°C hot water, and the film elongation after immersion in 50°C hot water is 50% or more and 300% or less. Hereafter, "water-based pigment ink for textile inkjet printing" may be simply referred to as "ink" or "water-based ink."

[0010] In order to provide an aqueous pigment ink for inkjet printing that produces printed materials with excellent wash fastness, the inventors diligently conducted research and found that when an ink film prepared by drying the ink is immersed in water, the weight and elongation of the ink film may change. Furthermore, they found that the rate of change in weight of the ink film before and after water immersion, and the elongation of the ink film after water immersion, are closely related to the wash fastness of printed materials using that ink. In particular, using 50°C warm water to immerse the ink film can increase the correlation between the weight change rate of the ink film before and after water immersion and the wash fastness of the printed material, as well as the correlation between the elongation of the ink film after water immersion and the wash fastness of the printed material. Although not bound by any specific theory, it is presumed that this is because contacting the ink film with 50°C warm water allows the resin molecular structure and bonding state within the ink film to be brought to a structure and state closer to that of the film when evaluating actual wash fastness.

[0011] If the weight of the ink film increases after immersion in 50°C hot water, it is possible that water has penetrated the ink film and / or that the ink film has been altered by water. In the former case, it is suggested that the density of the ink film is low, and the ink film is likely to be easily damaged by external forces during washing. In the latter case, it is likely that repeated washing will cause the ink film to deteriorate and become easily damaged. For these reasons, from the viewpoint of wash fastness, it is preferable that the weight change rate of the ink film before and after immersion in 50°C hot water is small, preferably 20% or less.

[0012] If the elongation of the ink film after immersion in 50°C hot water is 50% or more, the ink film is likely to follow the stretching of the fabric during washing, and the ink film is less likely to be damaged by external forces. On the other hand, generally, the higher the elongation of a resin, the weaker its elasticity, that is, the force that tries to return to its original shape when stretched. However, if the elongation of the ink film after immersion in 50°C hot water is 300% or less, the ink film is likely to have sufficient elasticity to withstand the stretching and contracting of the fabric during washing, and therefore the ink film is less likely to be damaged.

[0013] Thus, when the weight change rate of the ink film formed by drying the ink before and after immersion in warm water at 50°C is 20% or less, and the film elongation after immersion in warm water at 50°C is 50% or more and 300% or less, the washing fastness can be made good.

[0014] The aqueous pigment ink for printing and dyeing inkjet can contain a pigment as a coloring material.

[0015] As the pigment, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, and lake pigments for dyeing, and inorganic pigments such as carbon black and metal oxides can be used. Examples of azo pigments include soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments. Examples of phthalocyanine pigments include metal phthalocyanine pigments and metal-free phthalocyanine pigments. Examples of polycyclic pigments include quinacridone-based pigments, perylene-based pigments, perinone-based pigments, isoindoline-based pigments, isoindolinone-based pigments, dioxazine-based pigments, thioindigo-based pigments, anthraquinone-based pigments, quinophthalone-based pigments, metal complex pigments, and diketopyrrolopyrrole (DPP). Examples of carbon black include furnace carbon black, lamp black, acetylene black, and channel black. Examples of metal oxides include titanium oxide and zinc oxide. These pigments may be used alone or in combination of two or more.

[0016] From the viewpoints of ejection stability and storage stability, the average particle diameter of the pigment particles in the ink is preferably 300 nm or less, more preferably 150 nm or less, and even more preferably 100 nm or less as the volume-based average value in the particle size distribution measured by the dynamic light scattering method. From the viewpoints of printing density and ink viscosity, the content of the pigment is preferably 0.1 to 15% by mass, more preferably 1 to 15% by mass, and even more preferably 2 to 10% by mass based on the total amount of the ink.

[0017] Self-dispersing pigments may be incorporated as pigments. Self-dispersing pigments are pigments in which hydrophilic functional groups are introduced to the surface of the pigment by chemical or physical treatment. The hydrophilic functional groups introduced into the self-dispersing pigment are preferably ionic, and by charging the pigment surface anionic or cationic, the pigment particles can be stably dispersed in water by electrostatic repulsion. Preferred anionic functional groups include carboxyl groups, sulfo groups, and phosphate groups. Preferred cationic functional groups include quaternary ammonium groups and quaternary phosphonium groups.

[0018] These hydrophilic functional groups may be directly bonded to the pigment surface or bonded via other atomic groups. Examples of other atomic groups include, but are not limited to, alkylene groups, phenylene groups, and naphthylene groups. Examples of pigment surface treatment methods include diazotization, sulfonation, hypochlorite treatment, humic acid treatment, and vacuum plasma treatment.

[0019] As self-dispersing pigments, for example, the CAB-O-JET series from Cabot Corporation, such as "CAB-O-JET200," "CAB-O-JET300," "CAB-O-JET250C," "CAB-O-JET260M," "CAB-O-JET270," "CAB-O-JET400," and "CAB-O-JET450C," and from Orient Chemical Industries, Ltd., such as "BONJET BLACK CW-1," "BONJET BLACK CW-2," "BONJET BLACK CW-3," and "BONJET BLACK CW-4," can be preferably used (all are product names). As a pigment, microencapsulated pigments, in which the pigment is coated with resin, may be used.

[0020] Pigment dispersions in which the pigment is pre-dispersed with a pigment dispersant may be used. Examples of commercially available pigment dispersions dispersed with a pigment dispersant include the HOSTAJET series from Clariant and the FUJI SP series from Fuji Pigment Co., Ltd. Pigment dispersions dispersed with a pigment dispersant, as described later, may also be used.

[0021] To stably disperse pigments in ink, pigment dispersants such as polymer dispersants and surfactant-type dispersants can be used. Examples of polymer dispersants include commercially available products such as the TEGO Disperse series from EVONIK, including "TEGO Disperse 740W," "TEGO Disperse 750W," "TEGO Disperse 755W," "TEGO Disperse 757W," and "TEGO Disperse 760W," and the Solsperse series from Lubrizol Japan, including "Solsperse 20000," "Solsperse 27000," "Solsperse 41000," "Solsperse 41090," "Solsperse 43000," "Solsperse 44000," and "Solsperse 46000." Examples include the Joncryl series from BASF Japan Ltd., such as "Joncryl 57," "Joncryl 60," "Joncryl 62," "Joncryl 63," "Joncryl 71," and "Joncryl 501"; products from Big Chemie Japan Co., Ltd., such as "DISPERBYK-102," "DISPERBYK-185," "DISPERBYK-190," "DISPERBYK-193," and "DISPERBYK-199"; and products from Daiichi Kogyo Seiyaku Co., Ltd., such as "Polyvinylpyrrolidone K-30" and "Polyvinylpyrrolidone K-90" (all are brand names). Examples of surfactant-type dispersants include anionic surfactants such as the Demol series manufactured by Kao Corporation, including "Demol P," "Demol EP," "Demol N," "Demol RN," "Demol NL," "Demol RNL," and "Demol T-45," and nonionic surfactants such as the Emulgen series manufactured by Kao Corporation, including "Emulgen A-60," "Emulgen A-90," "Emulgen A-500," "Emulgen B-40," "Emulgen L-40," and "Emulgen 420" (all are product names).

[0022] The pigment dispersant may be used alone or in combination of two or more types. When using a pigment dispersant, the amount contained in the ink varies depending on the type and is not particularly limited, but generally, a mass ratio of 0.005 to 0.5 per 1 part pigment is preferred.

[0023] Water-based pigment inks for textile inkjet printing may contain water-dispersible resins. The water-dispersible resin is preferably a resin particle that can be dispersed in an aqueous solvent. The water-dispersible resin can be incorporated into the ink, for example, as an oil-in-water resin emulsion. The water-dispersible resin may be a self-emulsifying type in which hydrophilic groups and / or hydrophilic segments are introduced to ensure stable dispersion in water, or it may be a water-dispersible resin obtained by using an external emulsifier.

[0024] The water-dispersible resin may be an anionic water-dispersible resin, a cationic water-dispersible resin, a nonionic water-dispersible resin, or an amphoteric water-dispersible resin. For example, an anionic water-dispersible resin, a nonionic water-dispersible resin, or a combination thereof can be preferably used as the water-dispersible resin.

[0025] From the viewpoint of inkjet ejection performance, the average particle size of the water-dispersible resin is preferably 600 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. For example, the average particle size of the resin particles may be in the range of 10 nm to 600 nm, in the range of 50 nm to 300 nm, or in the range of 50 nm to 200 nm. The average particle size of the water-dispersible resin is the volume-based average particle size determined by dynamic light scattering.

[0026] As for the type of water-dispersible resin, it is preferable to use a resin that forms a transparent coating film.

[0027] Examples of water-dispersible resins include, Conjugated diene resins such as styrene-butadiene copolymers, methyl methacrylate-butadiene copolymers, and vinyl chloride-vinyl acetate copolymers; Acrylic resins such as polymers of acrylic acid esters and methacrylic acid esters, or copolymers thereof with styrene, etc. Vinyl resins such as ethylene-vinyl acetate copolymer, Alternatively, functionally modified resins using monomers containing functional groups such as carboxyl groups from these various resins; Examples of water-dispersible resins include melamine resin, urea resin, polyurethane resin, polyester resin, polyolefin resin, silicone resin, polyvinyl butyral resin, and alkyd resin. Resin emulsions of these individual resins may be used, or hybrid resin emulsions may be used.

[0028] Among these water-dispersible resins, for example, acrylic resins, polyurethane resins, or combinations thereof can be preferably used. The polyurethane resin may be either aliphatic polyurethane or aromatic polyurethane. Examples of polyurethane resins include ether-based polyurethane resins, ester-based polyurethane resins, ester-ether-based polyurethane resins, and carbonate-based polyurethanes.

[0029] These water-dispersible resins may be used individually, but from the viewpoint of easily obtaining the desired ink film properties, it is preferable to use two or more types in combination. The ink preferably contains at least two types selected from the group consisting of, for example, water-dispersible acrylic resins and water-dispersible polyurethane resins. For example, multiple types of water-dispersible polyurethane resins may be combined, or a water-dispersible acrylic resin and a water-dispersible polyurethane resin may be combined.

[0030] The glass transition temperature of water-dispersible resins is not particularly limited. The glass transition temperature of a water-dispersible resin is preferably 150°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower. On the other hand, the glass transition temperature of a water-dispersible resin is preferably -50°C or higher, more preferably -40°C or higher, and even more preferably -30°C or higher. The glass transition temperature of a water-dispersible resin is preferably -50°C to 150°C, more preferably -40°C to 100°C, and even more preferably -30°C to 80°C.

[0031] The ink preferably contains two or more water-dispersible resins with different glass transition temperatures. For example, the ink preferably contains a water-dispersible resin with a glass transition temperature of 15°C or higher and a water-dispersible resin with a glass transition temperature of less than 15°C.

[0032] For water-dispersible resins with a glass transition temperature of 15°C or higher, the glass transition temperature is more preferably 20°C or higher, and even more preferably 30°C or higher. For water-dispersible resins with a glass transition temperature of 15°C or higher, for example, the glass transition temperature is more preferably 15°C to 150°C, even more preferably 20°C to 100°C, and even more preferably 30°C to 80°C.

[0033] For water-dispersible resins having a glass transition temperature of less than 15°C, the glass transition temperature is more preferably 14°C or lower, even more preferably 10°C or lower, and even more preferably 5°C or lower. For water-dispersible resins having a glass transition temperature of less than 15°C, for example, the glass transition temperature is more preferably -50°C or higher and less than 15°C, even more preferably -50°C to 14°C, even more preferably -40°C to 10°C, and even more preferably -30°C to 5°C.

[0034] In this disclosure, the glass transition temperature (Tg) of the resin can be measured according to differential scanning calorimetry (DSC).

[0035] The elongation of the film of the water-dispersible resin is not particularly limited. The elongation of the film of the water-dispersible resin is preferably 1% or more, more preferably 2% or more, and even more preferably 5% or more. On the other hand, the elongation of the film of the water-dispersible resin is preferably 1800% or less, more preferably 1700% or less, and even more preferably 1600% or less. For example, the elongation of the film of the water-dispersible resin is preferably 1 to 1800%, more preferably 2 to 1700%, and even more preferably 5 to 1600%.

[0036] The ink preferably contains two or more water-dispersible resins with different film elongation properties.

[0037] For example, the ink preferably contains a water-dispersible resin with a film elongation of 400% or more and a water-dispersible resin with a film elongation of less than 400%.

[0038] For water-dispersible resins with a film elongation of 400% or more, a film elongation of 500% or more is more preferable, 600% or more is even more preferable, and 700% or more is even more preferable. For water-dispersible resins with a film elongation of 400% or more, for example, a film elongation of 400-1800% is more preferable, 500-1700% is even more preferable, 600-1700% is even more preferable, and 700-1600% is even more preferable.

[0039] For water-dispersible resins with a film elongation of less than 400%, the film elongation is more preferably 300% or less, even more preferably 250% or less, even more preferably 200% or less, even more preferably 150% or less, and even more preferably 100% or less. For water-dispersible resins with a film elongation of less than 400%, the film elongation is preferably, for example, 1% or more and less than 400%, more preferably 1 to 300%, even more preferably 2 to 250%, even more preferably 2 to 200%, even more preferably 2 to 250%, even more preferably 2 to 150%, and even more preferably 5 to 100%.

[0040] Here, the elongation of the film of the water-dispersible resin can be measured according to the following procedure. First, an aqueous resin emulsion of a water-dispersible resin is applied to a polytetrafluoroethylene sheet so that the film thickness after drying is 500 μm. After drying at 23°C for 15 hours, then at 80°C for 6 hours, and then at 120°C for 20 minutes, the resin film is peeled off the sheet to create a resin film. This resin film is punched out using a dumbbell-shaped test piece punching die No. 8 conforming to JIS K6251 to create test pieces.

[0041] Using a tensile testing machine, under the conditions of a measurement temperature of 20°C, a measurement speed of 500 mm / min, a chuck distance of 20 mm, and a load cell load of 50 N, the test specimen prepared as described above was stretched, and the length of the test specimen that stretched until it fractured (also referred to as "length of the test specimen after stretching") L was measured. RF Measure the length L of the test specimen before stretching. RF0 and the length L of the specimen after elongation RFUsing this method, the film elongation (%) can be calculated using the following formula. Film elongation (%) = {(L RF -L RF0 ) / L RF0}×100

[0042] For tensile testing, the Tensilon universal testing machine RTC-1225A (manufactured by Orientec Co., Ltd.) can be used.

[0043] Examples of commercially available aqueous resin emulsions of water-dispersible resins include "Superflex 500M" and "Superflex 460" from Daiichi Kogyo Seiyaku Co., Ltd., "DAOTAN TW6493 / 35WA" from Daicel Ornex Co., Ltd., "ADEKA BONTITER HUX-2520" and "ADEKA BONTITER HUX-841" from ADEKA Corporation, and "NeoCryl XK-12" from Covestro Coating Resins (all are product names).

[0044] While a single water-dispersible resin may be used, it is more preferable to use two or more types in combination. The amount of water-dispersible resin is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, relative to the total amount of ink. The amount of water-dispersible resin is preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and even more preferably 12% by mass or less, relative to the total amount of ink. For example, the amount of water-dispersible resin is preferably 1 to 25% by mass, more preferably 1 to 20% by mass, even more preferably 2 to 15% by mass, and even more preferably 3 to 12% by mass, relative to the total amount of ink.

[0045] When the ink contains two or more water-dispersible resins with different film elongation rates, the mass ratio of these resins is not particularly limited. It is preferable to select them appropriately based on the film elongation rates of the water-dispersible resins. For example, the mass ratio of a water-dispersible resin with a film elongation rate of 400% or more to a water-dispersible resin with a film elongation rate of less than 400% is preferably 9:1 to 3:7, and more preferably 4:1 to 2:3.

[0046] The amount of water-dispersible resin with a film elongation of 400% or more is preferably 1% by mass or more, and more preferably 2% by mass or more, relative to the total amount of ink. The amount of water-dispersible resin with a film elongation of 400% or more is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less, relative to the total amount of ink. The amount of water-dispersible resin with a film elongation of 400% or more is preferably, for example, 1 to 15% by mass, more preferably 2 to 10% by mass, and even more preferably 2 to 8% by mass, relative to the total amount of ink.

[0047] For water-dispersible resins with a film elongation of less than 400%, the amount is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, relative to the total amount of ink. For water-dispersible resins with a film elongation of less than 400%, the amount is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, relative to the total amount of ink. For water-dispersible resins with a film elongation of less than 400%, the amount is preferably, for example, 1 to 20% by mass, more preferably 2 to 15% by mass, and even more preferably 3 to 10% by mass, relative to the total amount of ink.

[0048] For water-dispersible resins with a film elongation of 400% or more, the amount is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, relative to the total amount of water-dispersible resin in the ink. For water-dispersible resins with a film elongation of 400% or more, the amount is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, relative to the total amount of water-dispersible resin in the ink. For water-dispersible resins with a film elongation of 400% or more, the amount is preferably 30 to 90% by mass, more preferably 35 to 85% by mass, and even more preferably 40 to 80% by mass, relative to the total amount of water-dispersible resin in the ink.

[0049] For water-dispersible resins with a film elongation of 400% or less, the amount is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to the total amount of water-dispersible resin in the ink. For water-dispersible resins with a film elongation of 400% or less, the amount is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, relative to the total amount of water-dispersible resin in the ink. For water-dispersible resins with a film elongation of 400% or less, the amount is preferably 10 to 70% by mass, more preferably 15 to 65% by mass, and even more preferably 20 to 60% by mass, relative to the total amount of water-dispersible resin in the ink.

[0050] Water-based pigment inks for textile inkjet printing preferably contain water, and the main solvent may be water. While there are no particular restrictions on the type of water used, it is preferable to use water that contains as few ionic components as possible. In particular, from the viewpoint of the storage stability of the ink, it is preferable to use a water with a low content of polyvalent metal ions such as calcium. For the water used, for example, deionized water, distilled water, or ultrapure water may be used.

[0051] From the viewpoint of adjusting the viscosity of the ink, water is preferably included in an amount of 25 to 80% by mass, more preferably 30 to 85% by mass, and even more preferably 35 to 80% by mass, relative to the total amount of ink.

[0052] Water-based pigment inks for textile inkjet printing preferably contain a water-soluble organic solvent. As the water-soluble organic solvent, an organic compound that is liquid at room temperature and soluble in water can be used, and it is preferable to use a water-soluble organic solvent that mixes uniformly with an equal volume of water at 1 atmosphere and 20°C. Examples include lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and 2-methyl-2-propanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polypropylene glycol; glycerins such as glycerin, diglycerin, triglycerin, and polyglycerin; acetins such as monoacetin and diacetin; and ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether. Glycol ethers such as ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether can be used; triethanolamine, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, β-thiodiglycol, sulfolane, etc. The boiling point of the water-soluble organic solvent is preferably 100°C or higher, and more preferably 150°C or higher.

[0053] As the water-soluble organic solvent, it is preferable to use a solvent with high drying properties and a relatively low boiling point. The boiling point of such a water-soluble organic solvent is preferably 250°C or lower, and more preferably 220°C or lower. Examples of water-soluble organic solvents with a boiling point of 250°C or lower include ethylene glycol (boiling point 197°C), 1,2-butanediol (boiling point 194°C), 1,3-butanediol (boiling point 207°C), 2-methyl-1,3-propanediol (boiling point 214°C), and diethylene glycol (boiling point 244°C).

[0054] Water-soluble organic solvents may be used individually, or two or more may be used in combination as long as they form a single phase with water. The content of water-soluble organic solvents in the ink is preferably 5 to 50% by mass, and more preferably 10 to 35% by mass, based on the total amount of ink.

[0055] The content of water-soluble organic solvents with a boiling point of 250°C or lower relative to the total amount of water-soluble organic solvents in the ink is preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, and even more preferably 70% by mass or more. The content of water-soluble organic solvents with a boiling point of 250°C or lower relative to the total amount of water-soluble organic solvents in the ink may be, for example, 99% by mass or less, 90% by mass or less, or 80% by mass or less. For example, the content of water-soluble organic solvents with a boiling point of 250°C or lower relative to the total amount of water-soluble organic solvents in the ink is preferably 20 to 99% by mass, more preferably 40 to 99% by mass, even more preferably 60 to 90% by mass, and even more preferably 70 to 80% by mass. The amount of water-soluble organic solvent with a boiling point of 250°C or lower is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the total amount of ink. The amount of water-soluble organic solvent with a boiling point of 250°C or lower is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to the total amount of ink. For example, the amount of water-soluble organic solvent with a boiling point of 250°C or lower is preferably 2 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 20% by mass, relative to the total amount of ink.

[0056] Water-based pigment inks for textile inkjet printing preferably contain a crosslinking agent. Examples of crosslinking agents include carbodiimide compounds, isocyanate compounds, and oxazoline compounds. Examples of commercially available carbodiimide compounds include "Carbodilite V-02" manufactured by Nisshinbo Chemical Co., Ltd. Examples of commercially available isocyanate compounds include "Takenate WB-3021" manufactured by Mitsui Chemicals, Inc. Examples of commercially available oxazoline compounds include "Epocross K2020E" manufactured by Nippon Shokubai Co., Ltd.

[0057] The crosslinking agent may be used alone or in combination of two or more types. The amount of crosslinking agent is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more, relative to the total amount of ink. The amount of crosslinking agent is preferably 2% by mass or less, and more preferably 1% by mass or less, relative to the total amount of ink. The amount of crosslinking agent is preferably 0.01 to 2% by mass, and more preferably 0.1 to 1% by mass, relative to the total amount of ink.

[0058] Water-based pigment inks for textile printing inkjet applications preferably contain a surfactant. As the surfactant, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, or combinations thereof can be preferably used, with nonionic surfactants being more preferable. In addition, either low molecular weight surfactants or high molecular weight surfactants may be used.

[0059] The HLB value of the surfactant is preferably 5 to 20, and more preferably 10 to 18.

[0060] Examples of nonionic surfactants include ester-type surfactants such as glycerin fatty acid esters and fatty acid sorbitan esters; ether-type surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxypropylene alkyl ethers; ether ester-type surfactants such as polyoxyethylene sorbitan fatty acid esters; acetylene-based surfactants; silicone-based surfactants; and fluorine-based surfactants. Among these, acetylene-based surfactants such as acetylene glycol-based surfactants can be preferably used.

[0061] Examples of acetylene-based surfactants include acetylene glycol-based surfactants, acetylene alcohol-based surfactants, and surfactants having an acetylene group. The acetylene glycol-based surfactant is a glycol having an acetylene group, preferably a glycol having a symmetrical structure with the acetylene group located in the center, and may also have a structure in which ethylene oxide is added to the acetylene glycol. Examples of commercially available acetylene-based surfactants include the Surfinol series from Evonik Industries, such as "Surfinol 104E," "Surfinol 104H," "Surfinol 420," "Surfinol 440," "Surfinol 465," and "Surfinol 485," and the Orfin series from Nisshin Chemical Industry Co., Ltd., such as "Orfin E1004," "Orfin E1010," and "Orfin E1020" (all are product names).

[0062] Examples of silicone-based surfactants include polyether-modified silicone-based surfactants, alkyl-aralkyl copolymerized silicone-based surfactants, and acrylic silicone-based surfactants. Examples of commercially available silicone-based surfactants include "Sylface SAG002" and "Sylface 503A" manufactured by Nisshin Chemical Industry Co., Ltd. (both are product names).

[0063] Other nonionic surfactants include, for example, polyoxyethylene alkyl ether-based surfactants such as the Emulgen series manufactured by Kao Corporation, including "Emulgen 102KG," "Emulgen 103," "Emulgen 104P," "Emulgen 105," "Emulgen 106," "Emulgen 108," "Emulgen 120," "Emulgen 147," "Emulgen 150," "Emulgen 220," "Emulgen 350," "Emulgen 404," "Emulgen 420," "Emulgen 705," "Emulgen 707," "Emulgen 709," "Emulgen 1108," "Emulgen 4085," and "Emulgen 2025G" (all are product names).

[0064] Examples of anionic surfactants include the Emal series manufactured by Kao Corporation, such as "Emal 0," "Emal 10," "Emal 2F," "Emal 40," and "Emal 20C"; the Neoperex series, such as "Neoperex GS," "Neoperex G-15," "Neoperex G-25," and "Neoperex G-65"; the Perex series, such as "Perex OT-P," "Perex TR," "Perex CS," "Perex TA," "Perex SS-L," and "Perex SS-H"; and the Demol series, such as "Demol N," "Demol NL," "Demol RN," and "Demol MS" (all are product names).

[0065] Examples of cationic surfactants include the Acetamine series "Acetamine 24" and "Acetamine 86" manufactured by Kao Corporation, the Cortamine series "Cortamine 24P", "Cortamine 86P", "Cortamine 60W", and "Cortamine 86W", and the Sanizol series "Sanizol C" and "Sanizol B-50" (all are product names).

[0066] Examples of amphoteric surfactants include the Anchitol series manufactured by Kao Corporation, such as "Anchitol 20BS," "Anchitol 24B," "Anchitol 86B," "Anchitol 20YB," and "Anchitol 20N" (all are product names). While it is preferable to use one of the above-mentioned surfactants alone, two or more may be used in combination.

[0067] The surfactant content is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.2 to 3% by mass, relative to the total amount of ink.

[0068] Water-based pigment inks for textile inkjet printing may contain other components as needed. These other components may include pH adjusters, preservatives, and the like.

[0069] The method for manufacturing aqueous pigment ink for textile inkjet printing is not particularly limited and can be manufactured by any known method. For example, the ink can be obtained by dispersing all components together or in separate portions in a stirrer such as a three-in-one motor, and optionally passing the mixture through a filter such as a membrane filter.

[0070] From the viewpoint of improving wash fastness, the weight change rate of the ink film prepared by drying the ink before and after immersion in 50°C hot water is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. The weight change rate of the ink film prepared by drying the ink, before and after immersion in 50°C hot water, may be, for example, 0%, greater than 0%, 0.1% or more, or 1% or more. The weight change rate of the ink film prepared by drying the ink before and after immersion in 50°C hot water may be, for example, 0-20%, 0.1-15%, or 1-15%.

[0071] The percentage change in weight of an ink film prepared by drying the ink, before and after immersion in 50°C hot water, can be determined as follows. First, ink is applied to a polytetrafluoroethylene sheet so that the film thickness after drying is 200 μm. After drying at 70°C for 60 minutes, then at 120°C for 20 minutes, and then at 160°C for 10 minutes, the sheet is peeled off to create an ink film. The drying conditions are not limited to those described above, as long as they do not cause bubbles to be introduced due to the boiling of the ink and allow for the creation of a smooth and homogeneous ink film by applying a temperature close to the maximum temperature applied to actual printed materials.

[0072] The ink film prepared as described above is punched out using a dumbbell-shaped test piece punching blade No. 8, conforming to JIS K6251, to produce test pieces. After measuring the weight (A) of the prepared test specimen, the specimen is immersed in 50°C hot water and kept in the hot water for 24 hours. After removing it and wiping off any water droplets from the specimen, the specimen is dried in a constant temperature room (23°C, 50%) for 2 hours, and then the weight (B) of the specimen is measured. The weight change rate before and after immersion in 50°C hot water can be calculated using the weight of the specimen before immersion (A) and the weight of the specimen after immersion (B), as measured above, using the following formula. Weight change rate (%) before and after immersion in 50°C hot water = {(BA) / A} × 100

[0073] The weight change rate of an ink film prepared by drying the ink before and after immersion in 50°C hot water can be adjusted, for example, by adjusting the density of the ink film. For example, increasing the density of the ink film and improving its water resistance can reduce the weight change rate before and after immersion in 50°C hot water. Methods for increasing the density of the ink film include, for example, reducing the amount of high-boiling-point water-soluble organic solvent used and instead using a low-boiling-point water-soluble organic solvent to improve drying properties, and incorporating a crosslinking agent into the ink. Any one of these methods may be used, or a combination of two or more may be used.

[0074] From the perspective of withstanding the expansion and contraction of the fabric during washing and improving the washing fastness thereby, the film elongation of the ink film prepared by drying the ink after immersion in warm water at 50°C is preferably 300% or less, more preferably 250% or less, and even more preferably 200% or less. On the other hand, from the perspective of the ink film's ability to follow the elongation of the fabric during washing and improving the washing fastness thereby, the film elongation of the ink film prepared by drying the ink after immersion in warm water at 50°C is preferably 50% or more, more preferably 70% or more, and even more preferably 100% or more. The film elongation of the ink film prepared by drying the ink after immersion in warm water at 50°C is preferably 50 to 300%, more preferably 70 to 250%, and even more preferably 100 to 200%.

[0075] The film elongation of the ink film prepared by drying the ink after immersion in warm water at 50°C can be measured according to the following procedure. First, an ink film can be prepared by the method of preparing an ink film described in the measurement of the weight change rate of the ink film before and after immersion in warm water at 50°C of the ink film prepared by drying the ink. The ink film thus prepared is punched out using a dumbbell-shaped test piece punching blade No. 8 conforming to JIS K6251 to prepare a test piece.

[0076] Using a tensile testing machine, under the conditions of a measurement temperature of 20°C, a measurement speed of 500 mm / min, a chuck distance of 20 mm, and a load cell load of 50 N, the test piece prepared as described above is extended, and the length of the test piece that extends until the test piece breaks (also referred to as the "length of the test piece after extension") L IF is measured, the length L of the test piece before extension IF0 and the length L of the test piece after extension IF are used, and the film elongation (%) can be obtained by the following formula. Film elongation (%) = {(L IF - L IF0 ) / L IF0} × 100

[0077] For tensile testing, the Tensilon universal testing machine RTC-1225A (manufactured by Orientec Co., Ltd.) can be used.

[0078] The elongation of an ink film prepared by drying ink after immersion in 50°C hot water can be adjusted, for example, by the type, combination, and mixing ratio of water-dispersible resins. For example, it is preferable to use two or more water-dispersible resins with different elongation properties. The mixing ratio of two or more water-dispersible resins with different elongation properties should be selected considering the elongation of each resin. It is preferable to adjust the film elongation of the ink film, taking into consideration that it tends to decrease after immersion in hot water compared to before immersion.

[0079] The pH of water-based pigment inks for textile inkjet printing is preferably 7.0 to 10.0, and more preferably 7.5 to 9.0, from the viewpoint of ink storage stability. The viscosity of aqueous pigment ink for textile inkjet printing is preferably 1 to 30 mPa·s at 23°C, for example, from the viewpoint of inkjet ejection performance.

[0080] One embodiment of the aqueous pigment ink for textile inkjet printing can be preferably used for printing on fabric. Examples of fibers included in the fabric include natural fibers such as cotton, silk, wool, and linen; and chemical fibers such as polyester, acrylic, polyurethane, nylon, rayon, cupro, and acetate. The fabric may contain one or more types of fibers. The fabric may also be woven, knitted, or nonwoven.

[0081] <Method of manufacturing printed materials> The following describes a method for manufacturing printed materials using an aqueous pigment ink for inkjet printing according to one embodiment. One embodiment of the method for manufacturing a printed fabric may include applying an aqueous pigment ink for inkjet printing to a fabric by an inkjet method. The aqueous pigment ink for inkjet printing described in the above embodiment can be used as the aqueous pigment ink for inkjet printing. As the fabric, the fabric described above as a fabric that can use the aqueous pigment ink for inkjet printing described in the above embodiment can be used.

[0082] The ink is preferably applied to the fabric by an inkjet method. The inkjet method is not particularly limited and may be any method such as a piezo method, electrostatic method, or thermal method. When using an inkjet printing device, it is preferable to eject droplets of pretreatment liquid or ink from the inkjet head based on a digital signal and to adhere the ejected droplets to the fabric.

[0083] The amount of ink applied to the fabric is not particularly limited, but for example, 5-60 g / m 2 Preferably, 10-30 g / m 2 This is preferable.

[0084] You may apply one type of ink to the fabric, or you may apply two or more types of ink to the fabric.

[0085] It is preferable to include a step of heat-treating the fabric after applying the ink to it. The heat treatment temperature can be appropriately selected depending on the material of the fabric, etc. For example, a heat treatment temperature of 100°C or higher is preferred, and 150°C or higher is more preferred. From the viewpoint of reducing damage to the fabric, a heat treatment temperature of 200°C or lower is preferred. The heating device is not particularly limited, but for example, a heat press, roll heater, hot air device, infrared lamp heater, etc., can be used. The heating time can be set appropriately depending on the heating method, etc. For example, 1 second to 10 minutes is preferred, and 5 seconds to 5 minutes is also acceptable.

[0086] A pretreatment solution may be applied to the fabric before applying the ink. After applying the ink to the fabric, a post-treatment solution may be applied to the fabric. For example, the fabric may be heat-treated after applying a pre-treatment solution and / or after applying ink and / or after applying a post-treatment solution.

[0087] <Note> This disclosure includes the following embodiments. (Note 1) A water-based pigment ink for textile inkjet printing, comprising a pigment, a water-dispersible resin, water, and a water-soluble organic solvent, A water-based pigment ink for textile printing, wherein the weight change rate of the ink film prepared by drying the aforementioned water-based pigment ink for textile printing is 20% or less before and after immersion in 50°C hot water, and the film elongation after immersion in 50°C hot water is 50% or more and 300% or less. (Note 2) The aqueous pigment ink for textile printing described in Appendix 1, wherein the weight change rate of the ink film before and after immersion in 50°C hot water is 10% or less. (Note 3) The aqueous pigment ink for textile printing described in Appendix 1 or 2, wherein the film elongation of the ink film after immersion in 50°C hot water is 100% or more and 200% or less. (Note 4) A method for producing a printed fabric, comprising applying an aqueous pigment ink for print inkjet printing described in any one of the appendices 1 to 3 to a fabric by an inkjet method. [Examples]

[0088] The embodiments of the present invention will be described in detail below with reference to examples. The present invention is not limited to the following embodiments.

[0089] 1. Preparation of water-based pigment inks for textile inkjet printing. Tables 1-3 show the ink formulations for Examples 1-9 and Comparative Examples 1-5. The raw materials were mixed according to the formulations shown in Tables 1-3, and the mixture was filtered through a 3 μm pore size membrane filter to obtain the ink. The quantities of each raw material shown in Tables 1-3 are in mass percent. In Tables 1-3, the quantities of pigment dispersions and resin emulsions are shown as the total amount including the aqueous medium, etc. Carbodilite V-02 (product name) and Epocross K2020E (product name) listed in the table also contain the aqueous medium, etc., and their quantities are shown in the table as the total amount including the aqueous medium, etc.

[0090] The details of the raw materials listed in Tables 1-3 are as follows:

[0091] (Pigment dispersion) CAB-O-JET400 (product name): Self-dispersing pigment dispersion (black), manufactured by Cabot Corporation, pigment content 15% by mass

[0092] (Resin emulsion) Superflex 500M (product name): Polyurethane resin emulsion, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., resin content 45% by mass, glass transition temperature (Tg): -39℃, film elongation: 1100% Superflex 460 (product name): Polyurethane resin emulsion, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., resin content 38% by mass, glass transition temperature (Tg): -21℃, film elongation: 750% DAOTAN TW6493 / 35WA (product name): Polyurethane resin emulsion, manufactured by Daicel Ornex Co., Ltd., resin content 33% by mass, glass transition temperature (Tg): 100℃, film elongation: 70% ADEKA Bonditor HUX-2520 (product name): Polyurethane resin emulsion, manufactured by ADEKA Corporation, resin content 32% by mass, film elongation: 5% Adekabonditer HUX-841 (product name): Polyurethane resin emulsion, manufactured by ADEKA Corporation, resin content 32% by mass, film elongation: 210% NeoCryl XK-12 (product name): Acrylic resin emulsion, manufactured by Covestro Coating Resins, resin content 45% by mass, glass transition temperature (Tg): 21℃

[0093] (Crosslinking agent) Carbodilite V-02 (product name): Carbodiimide compound, manufactured by Nisshinbo Chemical Co., Ltd., active ingredient 40% by mass Epocross K2020E (product name): Oxazoline compound, manufactured by Nippon Shokubai Co., Ltd., active ingredient 40% by mass

[0094] (Surfactants) Olphine E1010 (product name): Acetylene glycol-based surfactant, manufactured by Nisshin Chemical Industry Co., Ltd., active ingredient 100% by mass

[0095] (Water-soluble organic solvent) Glycerin: Manufactured by Fujifilm Wako Pure Chemical Corporation Diethylene glycol: Manufactured by Fujifilm Wako Pure Chemical Corporation

[0096] 2. Measurement of film elongation of resin emulsion The film elongation values ​​of the resin emulsions listed in the table were obtained using the following procedure. First, a resin emulsion was applied to a polytetrafluoroethylene sheet to achieve a film thickness of 500 μm after drying. The emulsion was then dried at 23°C for 15 hours, followed by 80°C for 6 hours, and finally 120°C for 20 minutes. The emulsion was then peeled off the sheet to create a resin film. This resin film was punched out using a dumbbell-shaped test specimen punching die (type 8) conforming to JIS K6251 to produce test specimens.

[0097] Using a Tensilon universal testing machine RTC-1225A (manufactured by Orientec Co., Ltd.), the prepared test specimen was stretched under the following conditions: measurement temperature 20°C, measurement speed 500 mm / min, chuck distance 20 mm, and load cell load 50 N. The length of the test specimen stretched until it fractured (also referred to as "length of the test specimen after stretching") was measured L. RF Measure the length L of the test specimen before stretching. RF0 and the length L of the specimen after elongation RF The film elongation (%) was calculated using the following formula. Elongation (%)={(L RF -L RF0 ) / L RF0}×100

[0098] 3. Measurement of the weight change rate of the ink film before and after immersion in 50°C hot water. The weight change rates of the ink film before and after immersion in 50°C hot water, as shown in the table, were obtained using the following procedure. First, ink was applied to a polytetrafluoroethylene sheet so that the film thickness after drying would be 200 μm. After drying at 70°C for 60 minutes, then at 120°C for 20 minutes, and then at 160°C for 10 minutes, the ink film was peeled off the sheet to create an ink film. This ink film was punched out using a dumbbell-shaped test piece punching die No. 8 in accordance with JIS K6251 to create test pieces.

[0099] After measuring the weight (A) of the prepared test specimen, the specimen was immersed in 50°C hot water and kept in the hot water for 24 hours. After removing it and wiping off any water droplets from the specimen, the specimen was dried in a constant temperature chamber (23°C, 50%) for 2 hours, and then the weight (B) of the specimen was measured. The weight change rate before and after immersion in 50°C hot water was calculated using the weight of the specimen before immersion (A) and the weight of the specimen after immersion (B), as measured above, using the following formula. Weight change rate (%) before and after immersion in 50°C hot water = {(BA) / A} × 100

[0100] 4. Measurement of film elongation after immersion of the ink film in 50°C hot water. The film elongation values ​​of the ink films listed in the table after immersion in 50°C hot water were obtained using the following procedure. Test specimens were prepared using the same method as described above for measuring the weight change rate of the ink film before and after immersion in 50°C hot water.

[0101] Using a Tensilon universal testing machine RTC-1225A (manufactured by Orientec Co., Ltd.), the length of the test specimen (also referred to as "length of the test specimen after stretching") was measured by stretching the prepared test specimen under the following conditions: measurement temperature 20°C, measurement speed 500 mm / min, chuck distance 20 mm, and load cell load 50 N. IF Measure the length L of the test specimen before stretching. IF0 and the length L of the specimen after elongation IF The film elongation (%) was calculated using the following formula. Film elongation (%) = {(L IF -L IF0 ) / L IF0}×100

[0102] 5. Preparation of printed materials Using the inks prepared as described above, printed materials for Examples 1-8 and Comparative Examples 1-5 were prepared according to the following procedure.

[0103] A cotton T-shirt manufactured by Toms Co., Ltd. (product name: Printstar) was used as the base material. A solid black image was printed on a 10cm x 20cm area of ​​the surface of this cotton T-shirt using an inkjet method with water-based pigment ink for textile printing. The ink application rate was 20g / m². 2 The ink was applied using a Mastermind MMP-8130 printing machine. After ink application, the printed material was heated and dried at 160°C for 2 minutes using a Fusion heat press to obtain the printed material.

[0104] 6. Evaluation of wash fastness The wash fastness of the printed materials in Examples 1-9 and Comparative Examples 1-5 was evaluated according to JIS L 844:2011 A-2 standard, and judged according to the following criteria. The results are shown in Tables 1-3. A: Discoloration grade 4 or higher B: Discoloration grade 3-4 C: Discoloration grade 3 or lower

[0105] [Table 1]

[0106] [Table 2]

[0107] [Table 3]

[0108] The printed materials in Examples 1 to 9 all exhibited good wash fastness. In contrast, in Comparative Examples 1 and 2, where both the weight change rate of the ink film before and after immersion in 50°C hot water and the film elongation after immersion in 50°C hot water were too high; Comparative Examples 3 and 4, where the weight change rate of the ink film before and after immersion in 50°C hot water was too high; Comparative Example 5, where the film elongation after immersion in 50°C hot water was too high; and Comparative Example 6, where the film elongation after immersion in 50°C hot water was too low, the wash fastness was reduced in all of these cases.

Claims

1. A water-based pigment ink for textile inkjet printing, comprising a pigment, a water-dispersible resin, water, and a water-soluble organic solvent, The aforementioned water-dispersible resin includes two or more water-dispersible resins with different film elongation rates of 5 to 1100%, The water-soluble organic solvent comprises at least one selected from the group consisting of ethylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, and diethylene glycol. A water-based pigment ink for textile printing, wherein the weight change rate of the ink film prepared by drying the aforementioned water-based pigment ink for textile printing is 20% or less before and after immersion in 50°C hot water, and the film elongation after immersion in 50°C hot water is 100% or more and 200% or less.

2. The aqueous pigment ink for textile printing according to claim 1, wherein the weight change rate of the ink film before and after immersion in 50°C hot water is 10% or less.

3. A method for producing a printed fabric, comprising applying the aqueous pigment ink for print inkjet printing described in claim 1 or 2 to a fabric by an inkjet method.

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