Ink for textile printing, ink set for textile printing, and textile printing method

Abstract

Provided is an ink for textile printing, the ink containing a pigment and a urethane resin having a weight average molecular weight of at least 50,000, wherein the urethane resin is a reaction product of a diol, a diisocyanate, and a monoalcohol having 1-6 carbon atoms and is a linear urethane resin including an alkyl group having 1-6 carbon atoms at a molecular chain terminal portion thereof.

Description

Textile printing ink, textile printing ink set, and textile printing method

[0001] The present disclosure relates to a textile printing ink, a textile printing ink set, and a textile printing method.

[0002] In recent years, various studies have been conducted on methods for textile printing on fabrics. For example, Patent Document 1 discloses an aqueous pigment inkjet ink that, when used for textile printing, has excellent storage stability, color development, and texture, as well as high wash and rub fastness, and that contains at least water (A), a pigment (B), an organic solvent (C), a surface conditioner (D), a binder resin (E), and a pigment dispersing resin (F), wherein the binder resin (E) is a polycarbonate-based urethane resin, and the pigment dispersing resin (F) is a styrene-acrylic resin having an alkyl group having 10 to 24 carbon atoms.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-206628

[0004] However, there are cases where prints obtained by printing on fabrics are required to have flexibility (i.e., flexibility in the bending direction; the same applies hereinafter) and rub fastness.

[0005] The present disclosure has been made in view of the above circumstances, and an object of one embodiment of the present disclosure is to provide a textile printing ink, a textile printing ink set, and a textile printing method that can provide a printed item that is excellent in flexibility and friction fastness.

[0006] The present disclosure includes the following aspects. <1> A textile printing ink comprising: a pigment; and a urethane resin having a weight-average molecular weight of 50,000 or more, wherein the urethane resin is a reaction product of a diol, a diisocyanate, and a monoalcohol having 1 to 6 carbon atoms, and is a linear urethane resin in which a terminal group of the molecular chain is an alkyl group having 1 to 6 carbon atoms. <2> The textile printing ink according to <1>, in which the proportion of ring structures in the urethane resin is 25 mass% or less. <3> The textile printing ink according to <1> or <2>, in which the urethane resin has a ClogP of 2.0 or more. <4> A textile printing ink set comprising the textile printing ink according to any one of <1> to <3>, and a pretreatment liquid containing a flocculant and water. <5> The textile printing ink set according to <4>, in which the flocculant contains a polyvalent metal salt. <6> The textile printing ink set according to <4> or <5>, in which the pretreatment liquid further contains a compound (A) represented by the following formula (A):

[0007]

[0008] In formula (A), m is an integer of 11 or more, and n is an integer of 12 or more.

[0009] <7> A textile printing method comprising an ink applying step of applying the textile printing ink according to any one of <1> to <3> to a fabric. <8> A textile printing method using the textile printing ink set according to any one of <4> to <6>, comprising: a pretreatment liquid applying step of applying the pretreatment liquid to a fabric, and an ink applying step of applying the textile printing ink to the area of ​​the fabric to which the pretreatment liquid has been applied. <9> The textile printing method according to <7> or <8>, in which the ink applying step applies the textile printing ink by an inkjet system. <10> The textile printing method according to any one of <7> to <9>, further comprising a step of performing a corona discharge treatment on the fabric before the ink applying step.

[0010] According to one embodiment of the present disclosure, it is possible to provide a textile printing ink, a textile printing ink set, and a textile printing method that can produce a printed item that is excellent in flexibility and rub fastness.

[0011] The pretreatment liquid, textile printing ink set, and textile printing method of the present disclosure will be described in detail below.

[0012] In this specification, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

[0013] As used herein, the amount of each component in a composition refers to the total amount of the components in the composition unless otherwise specified, when the composition contains multiple substances corresponding to each component. In this specification, a combination of two or more preferred aspects is a more preferred aspect. As used herein, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0014] Textile printing is carried out by applying ink to a fabric to form an image. Hereinafter, the fabric on which the image is formed is referred to as a printed item.

[0015] [Textile Printing Ink] The textile printing ink (hereinafter also simply referred to as "ink") of the present disclosure is a textile printing ink that contains a pigment and a urethane resin having a weight-average molecular weight of 50,000 or more, wherein the urethane resin is a reaction product of a diol, a diisocyanate, and a monoalcohol having 1 to 6 carbon atoms, and is a linear urethane resin in which the terminal group of the molecular chain is an alkyl group having 1 to 6 carbon atoms.

[0016] According to the textile printing ink of the present disclosure, it is possible to obtain a printed textile that is excellent in flexibility and rub fastness.

[0017] The flexibility effect is obtained by the fact that the terminal group of the molecular chain of the urethane resin in the textile printing ink is an alkyl group having 1 to 6 carbon atoms and that the urethane resin in the textile printing ink is a linear urethane resin. Here, the flexibility of the printed item means the flexibility in the bending direction when the printed item (i.e., fabric on which an image is recorded) is bent (i.e., the ease of bending).

[0018] The effect of rubbing fastness can be obtained by ensuring that the weight-average molecular weight of the urethane resin in the textile printing ink is at least 50,000. Here, the rubbing fastness of a printed textile means the strength of the image when the image portion of the printed textile is rubbed (i.e., the degree of color transfer).

[0019] Furthermore, the textile printing ink of the present disclosure containing the above-mentioned specific urethane resin (for example, the examples described below) is expected to produce an ink film with superior breaking elongation, even when compared to inks in which the terminal group of the molecular chain of the urethane resin in the ink is a group other than an alkyl group having 1 to 6 carbon atoms (for example, Comparative Example 1 described below), inks in which the weight-average molecular weight of the urethane resin in the ink is less than 50,000 (for example, Comparative Example 2 described below), and inks in which the urethane resin in the ink is a branched urethane resin rather than a linear urethane resin (for example, Comparative Example 3 described below). This is expected to provide a stress relaxation effect when the ink application amount is increased to increase the ink film thickness, and as a result, excellent rub fastness is expected to be obtained even when the ink application amount is increased. Additionally, generally, when the ink film has a low breaking elongation, rub fastness tends to decrease when the ink application amount is increased. The ink of the present disclosure can also solve the problem of reduced rub fastness when the ink application amount is increased.

[0020] Pigment The ink of the present disclosure contains at least one pigment.

[0021] The pigment may be either an organic pigment or an inorganic pigment that is normally commercially available. Examples of the pigment include those described in "Pigment Dictionary" edited by Seijiro Ito (published in 2000), "Industrial Organic Pigments" by W. Herbst and K. Hunger, and JP-A Nos. 2002-12607, 2002-188025, 2003-26978, and 2003-342503.

[0022] The pigment may be a water-insoluble pigment that can be dispersed in water with the aid of a dispersant, or may be a self-dispersing pigment. A self-dispersing pigment is a pigment that can be dispersed in water without the use of a dispersant. A self-dispersing pigment is a compound in which at least one hydrophilic group selected from the group consisting of a carbonyl group, a hydroxyl group, a carboxyl group, a sulfo group, a phosphate group, and salts thereof is chemically bonded to the surface of the pigment directly or via another group.

[0023] Examples of organic pigments include azo pigments, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Examples of azo pigments include azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments. Examples of polycyclic pigments include phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments. Examples of dye chelates include basic dye chelates and acid dye chelates.

[0024] Examples of inorganic pigments include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black.

[0025] In the ink of the present disclosure, the content of the pigment is preferably 1% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, and even more preferably 1% by mass to 10% by mass, relative to the total amount of the ink, from the viewpoints of image density and ink ejection properties.

[0026] The ink of the present disclosure may contain a dye as a colorant in addition to a pigment, however, from the viewpoint of suppressing elution of the colorant into the wash liquor during textile printing, the content of the dye is preferably less than 1% by mass, more preferably less than 0.1% by mass, and particularly preferably 0% by mass, relative to the total amount of the ink (i.e., it is particularly preferred that the ink does not contain a dye).

[0027] (Dispersant) The ink of the present disclosure may contain a dispersant to disperse the pigment. As the dispersant, a polymer dispersant is preferred, and a polymer dispersant containing at least one hydrophilic group is more preferred.

[0028] The polymer dispersant may be a random copolymer or a block copolymer, and may have a crosslinked structure.

[0029] In particular, from the viewpoint of improving the ejection properties, it is preferable that the pigment is dispersed using a polymer dispersant containing a crosslinked structure.

[0030] When preparing the ink of the present disclosure, a pigment aqueous dispersion in which a pigment is dispersed in water using a dispersant can also be used. Examples of pigment aqueous dispersions in which a pigment is dispersed in water using a dispersant include the pigment dispersion described in JP 2012-7148 A. Furthermore, commercially available pigment aqueous dispersions in which a pigment is dispersed in water using a polymer dispersant containing a crosslinked structure can also be used, such as Pro-jet Black APD1000 (manufactured by Fujifilm Imaging Colorants).

[0031] <Urethane Resin> The ink of the present disclosure contains a urethane resin (hereinafter also referred to as "urethane resin X") having a weight-average molecular weight of 50,000 or more. A weight-average molecular weight of 50,000 or more of urethane resin X contributes to the effect of improving the rub fastness of printed textiles. From the viewpoint of further improving rub fastness, the weight-average molecular weight of urethane resin X is preferably 55,000 or more, more preferably 60,000. There is no particular limitation on the upper limit of the weight-average molecular weight of urethane resin X, but examples of upper limits include 200,000 and 160,000.

[0032] In this disclosure, the weight-average molecular weight refers to a value measured by gel permeation chromatography (GPC). The specific measurement method is as follows. The GPC used is a Tosoh Corporation product named "HLC-8020GPC," and three Tosoh Corporation product names "TSKgel, SuperMultipore HZ-H" (4.6 mm ID x 15 cm) are used as columns, with THF (tetrahydrofuran) used as the eluent. The measurement is performed using a RI (differential refractive index) detector at a sample concentration of 0.45% by mass, a flow rate of 0.35 ml / min, a sample injection amount of 10 μl, and a measurement temperature of 40°C. The calibration curve is prepared using eight samples of "TSK Standard Polystyrene" manufactured by Tosoh Corporation under the product names: "F-40," "F-20," "F-4," "F-1," "A-5000," "A-2500," "A-1000," and "n-propylbenzene" as standard samples.

[0033] Urethane resin X is a reaction product of a diol, a diisocyanate, and a monoalcohol having 1 to 6 carbon atoms, and is a linear urethane resin in which the terminal groups of the molecular chain (i.e., groups located at both ends) are alkyl groups having 1 to 6 carbon atoms. More specifically, in urethane resin X, a linear molecular chain containing a urethane bond (i.e., a linear polyurethane molecular chain) is formed by the reaction of the diol and the diisocyanate, and both ends of this molecular chain are blocked with a monoalcohol having 1 to 6 carbon atoms. As a result, the terminal groups of the molecular chain are alkyl groups having 1 to 6 carbon atoms derived from the monoalcohol having 1 to 6 carbon atoms.

[0034] For the urethane resin X, reference can be made to the urethane resins described in WO 2021 / 065682, except for the range of weight average molecular weight and the type of terminal group. In this specification, the urethane resin may be referred to as polyurethane.

[0035] (Diol) The diol, which is a raw material for forming the urethane resin X, is not particularly limited as long as it is a compound containing two hydroxy groups. The diol, which is a raw material for forming the urethane resin X, may be one type or two or more types.

[0036] The diol may be a low molecular weight diol or a polymer diol, and specific examples of the polymer diol include polyether diol, polyester diol, polycaprolactone diol, polycarbonate diol, polybutadiene diol, polyisoprene diol, and polyolefin diol.

[0037] Specific examples of diols are shown below, but the diols are not limited to the following specific examples.

[0038]

[0039] In compounds (2-12) to (2-15), nC ７ H １５ , nC ９ H １９ , nC １１ H ２３ , and nC １７ H ３５ represent a normal heptyl group, a normal nonyl group, a normal undecyl group, and a normal heptadecyl group, respectively. Compound (2-16) PPG is polypropylene glycol, an example of a polyether diol, and n is the number of repeats. Compound (2-17) PEs is polyester diol, and n is the number of repeats, and Ra and Rb １ , and Rb ２ are each independently a divalent hydrocarbon group having 2 to 25 carbon atoms. The n Ra's in the compound (2-17) PEs may be the same or different. The n Rb's in the compound (2-17) PEs １ may be the same or different. Compound (2-18) PC is a polycarbonate diol, n is the number of repeats, and Rc １ and Rc ２ are each independently an alkylene group having 2 to 12 carbon atoms (preferably 3 to 8, more preferably 3 to 6). １may be the same or different. Compound (2-19) PCL is polycaprolactone diol, n and m each represent the number of repetitions, and Rd represents an alkylene group having 2 to 25 carbon atoms. Compound (2-22) PEG is polyethylene glycol, an example of a polyether diol, and n represents the number of repetitions.

[0040] In addition to the compounds described above, the diols also include the following compounds.

[0041]

[0042]

[0043] In addition to the compounds mentioned above, examples of diols include polybutadiene diol (hereinafter also referred to as "PBD"), polyisoprene diol (hereinafter also referred to as "PIP"), polyolefin diol, and the like.

[0044] Commercially available polymer diols may be used as the diol. For commercially available polymer diols, see the examples described below. For commercially available polymer diols, see paragraph 0111 of WO 2016 / 152254.

[0045] The diol also includes a compound containing a carboxy group, such as 2,2-dimethylolpropionic acid (DMPA) or 2,2-dimethylolbutanoic acid (DMBA).

[0046] (Diisocyanate) The diisocyanate, which is a raw material for forming the urethane resin X, is not particularly limited as long as it is a compound containing two isocyanate groups. The diisocyanate, which is a raw material for forming the urethane resin X, may be one type or two or more types. Specific examples of the diisocyanate, which is a raw material for forming the urethane resin X, are shown below, but the diisocyanate is not limited to the following specific examples.

[0047]

[0048] In addition, diisocyanates derived from the above specific examples can also be used as the diisocyanate. Examples of diisocyanates derived from the above specific examples include Duranate (registered trademark) D101, D201, and A101 (manufactured by Asahi Kasei Corporation).

[0049] (Monoalcohol having 1 to 6 carbon atoms) There are no particular limitations on the monoalcohol having 1 to 6 carbon atoms that is a raw material for forming the urethane resin X. Examples of monoalcohols having 1 to 6 carbon atoms include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, s-butyl alcohol, i-butyl alcohol, t-butyl alcohol, pentyl alcohol, and hexyl alcohol.

[0050] The monoalcohol having 1 to 6 carbon atoms forms an alkyl group having 1 to 6 carbon atoms as a terminal group of the molecular chain. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an s-butyl group, an i-butyl group, a t-butyl group, a pentyl group, and a hexyl group.

[0051] (Ring structure) The urethane resin X may or may not contain a ring structure. From the viewpoint of further improving the flexibility of the obtained printed textile, the proportion of the ring structure in the urethane resin X is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0052] Here, the proportion of ring structures in urethane resin X means the proportion (mass %) of the mass of atoms forming the rings and hydrogen atoms directly bonded to atoms forming the rings relative to the total mass of urethane resin X. Substituents (e.g., methyl groups) bonded to atoms forming the rings are not included in the calculation of the proportion of ring structures.

[0053] (Clog P) From the viewpoint of further improving the rub fastness of the printed textile, the Clog P of the urethane resin X is preferably 0.1 or more, more preferably 1.0 or more, even more preferably 2.0 or more, even more preferably 3.0 or more, and even more preferably 4.0 or more. There is no particular upper limit to the Clog P of the urethane resin X, but examples of the upper limit include 8.0, 7.0, and 6.0.

[0054] Here, "ClogP" is a parameter that represents the hydrophobicity of a compound. A higher ClogP indicates a higher hydrophobicity of the compound. ClogP is a value obtained by calculating the common logarithm logP of the partition coefficient P between 1-octanol and water. Known methods and software can be used to calculate ClogP. In the present disclosure, ClogP refers to a value obtained by the ClogP program incorporated into Cambridge Soft's ChemBioDraw Ultra 12.0.

[0055] The ink of the present disclosure can be prepared using an aqueous solution of urethane resin X. For a method for preparing the aqueous solution of urethane resin X, see the Examples described below.

[0056] The content of urethane resin X in the ink of the present disclosure is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 15% by mass, and even more preferably 3% by mass to 12.5% ​​by mass, relative to the total amount of ink. When the content of urethane resin X is 1% by mass or more, the breaking elongation of the film can be further improved, and the abrasion resistance can be further improved. When the content of urethane resin X is 20% by mass or less, this is advantageous in terms of reducing the viscosity of the ink, improving the filterability of the ink, and reducing the pressure applied when ejecting the ink.

[0057] <Water> The ink of the present disclosure preferably contains water. The water content in the ink of the present disclosure is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more, relative to the total amount of the ink. The upper limit of the water content depends on the contents of other components, but is, for example, 80% by mass relative to the total amount of the ink.

[0058] <Organic Solvent> The ink of the present disclosure preferably contains at least one organic solvent, which improves the ejection properties of the ink from an inkjet head when the textile printing ink of the present disclosure is an inkjet ink.

[0059] The organic solvent contained in the ink of the present disclosure is preferably an aqueous organic solvent.

[0060] The term "aqueous" in the aqueous organic solvent means that the amount of dissolution in 100 g of distilled water at 25° C. is more than 1 g. The amount of dissolution in the aqueous organic solvent is preferably 5 g or more, more preferably 10 g or more, and even more preferably 20 g or more.

[0061] Examples of the organic solvent include alcohol-based solvents, amide-based solvents, nitrile-based solvents, polyalkylene glycol-based solvents, and polyalkylene glycol alkyl ether-based solvents.

[0062] From the viewpoint of jetting properties, the ink of the present disclosure preferably contains an organic solvent having a boiling point of 240° C. or higher.

[0063] The boiling point of the organic solvent can be measured using a boiling point measuring device, for example, a product name "Dosa Therm 300" manufactured by Titan Technologies, Inc. The boiling point means the boiling point under 1 atmosphere (101,325 Pa).

[0064] Examples of organic solvents having a boiling point of 240°C or higher include polyhydric alcohols such as diethylene glycol (boiling point: 244°C), 1,6-hexanediol (boiling point: 250°C), 2-ethyl-1,3-hexanediol (boiling point: 243°C), triethylene glycol (boiling point: 287°C), tripropylene glycol (boiling point: 273°C), tetraethylene glycol (boiling point: 314°C), and glycerin (boiling point: 290°C); polyhydric alcohol alkyl ethers such as triethylene glycol methyl ether (boiling point: 249°C), tripropylene glycol methyl ether (boiling point: 243°C), triethylene glycol ethyl ether (boiling point: 256°C), diethylene glycol-n-hexyl ether (boiling point: 259°C), and tripropylene glycol-n-propyl ether (boiling point: 261°C); polyhydric alcohol aryl ethers such as propylene glycol phenyl ether (boiling point: 243°C), and ethylene glycol monobenzyl ether (boiling point: 256°C); Examples of suitable organic solvents include nitrogen-containing compounds such as 2-pyrrolidone (boiling point: 245°C). Among these, from the viewpoints of storage stability and jetting properties, glycerin or 2-pyrrolidone is preferred as the organic solvent. The ink may contain one or more solvents having a boiling point of 240°C or higher.

[0065] When the ink contains an organic solvent, the content of the organic solvent in the ink is preferably 1% by mass to 50% by mass, more preferably 10% by mass to 40% by mass, and even more preferably 20% by mass to 40% by mass, relative to the total amount of the ink.

[0066] (Surfactant) The ink of the present disclosure preferably contains at least one surfactant. The surfactant is not particularly limited, and known surfactants such as silicone-based surfactants, fluorine-based surfactants, and acetylene glycol-based surfactants can be used. When the ink of the present disclosure contains a surfactant, from the viewpoint of suppressing deflection of the ink when ejected from an inkjet head when the ink is an inkjet ink, the content of the surfactant is preferably 0.05% by mass to 2.00% by mass, and more preferably 0.10% by mass to 2.00% by mass, relative to the total amount of the ink.

[0067] (Colloidal Silica) The ink of the present disclosure preferably contains colloidal silica. When the ink of the present disclosure contains colloidal silica, the content of the solid content of the colloidal silica (i.e., silica particles) is preferably 0.01% by mass to 1.00% by mass, and more preferably 0.02% by mass to 0.10% by mass, relative to the total amount of the ink.

[0068] (Other Components) The ink of the present disclosure may contain other components in addition to the components described above, as necessary. Examples of other components include waxes, crosslinking agents (e.g., blocked isocyanate crosslinking agents), preservatives, co-sensitizers, UV absorbers, antioxidants, anti-fading agents, conductive salts, and basic compounds.

[0069] [Textile Printing Ink Set] The textile printing ink set (hereinafter also simply referred to as an ink set) of the present disclosure includes the textile printing ink of the present disclosure and a pretreatment liquid.

[0070] <Textile Printing Ink> The textile printing ink is as described above.

[0071] <Pretreatment Liquid> The pretreatment liquid is a liquid for pretreating the fabric before the textile printing ink is applied. Hereinafter, each component that can be contained in the pretreatment liquid will be described.

[0072] (Water) The pretreatment liquid preferably contains water. The water content in the pretreatment liquid is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more, relative to the total amount of the pretreatment liquid. The upper limit of the water content depends on the contents of other components, but is, for example, 95% by mass relative to the total amount of the ink.

[0073] (Organic Solvent) The pretreatment liquid may contain at least one organic solvent. The organic solvent that can be contained in the pretreatment liquid is the same as the organic solvent that can be contained in the ink.

[0074] (Flocculant) The pretreatment liquid preferably contains at least one flocculant, which further improves the flexibility of the printed textile. The flocculant preferably contains at least one selected from the group consisting of polyvalent metal salts, cationic compounds, and quaternary ammonium cations.

[0075] Polyvalent metal salts are compounds composed of divalent or higher metal ions and anions. Specific examples of polyvalent metal salts include calcium chloride, calcium nitrate, calcium sulfate, calcium acetate, calcium hydroxide, calcium carbonate, magnesium chloride, magnesium acetate, magnesium sulfate, magnesium carbonate, barium sulfate, barium chloride, zinc sulfide, zinc carbonate, and copper nitrate.

[0076] The cationic compound is not particularly limited as long as it is a compound having a cationic group, and examples thereof include compounds containing at least one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an onium salt. Examples of the onium salt include a sulfonium salt, an iodonium salt, a phosphonium salt, and an ammonium salt. Among these, the onium salt is preferably an ammonium salt.

[0077] The cationic compound may be a low molecular weight compound or a high molecular weight compound (i.e., a cationic polymer).

[0078] For the cationic compound, reference can be made to, for example, paragraphs 0017 to 0031 of WO 2021 / 065682.

[0079] The quaternary ammonium cation is preferably a cation represented by the following formula (1):

[0080]

[0081] In formula (1), R １ and R ２ are all groups having 10 or less carbon atoms.

[0082] R １ and R ２The number of carbon atoms in the group is more preferably 7 or less, and even more preferably 1 to 7.

[0083] Among them, R １ and R ２ are each preferably an unsubstituted alkyl group, a substituted alkyl group, a vinyl group, an aryl group, an allyl group, an alkyl ester group, a (meth)acryloyloxyalkyl group, or an amino group, more preferably an unsubstituted alkyl group, a substituted alkyl group, an allyl group, or a (meth)acryloyloxyalkyl group, and even more preferably an unsubstituted alkyl group, a substituted alkyl group, or an allyl group.

[0084] The unsubstituted alkyl group having 10 or less carbon atoms may be linear, branched, or cyclic. Of these, the unsubstituted alkyl group having 10 or less carbon atoms is preferably linear. The number of carbon atoms in the unsubstituted alkyl group is preferably 6 or less, more preferably 3 or less, and even more preferably 1 or 2.

[0085] The substituted alkyl group having 10 or less carbon atoms means an alkyl group having a substituent, and the number of carbon atoms including the substituent is 10 or less.

[0086] In the substituted alkyl group having 10 or less carbon atoms, the alkyl group may be linear, branched, or cyclic. In particular, in the substituted alkyl group having 10 or less carbon atoms, the alkyl group is preferably linear. The number of carbon atoms in the substituted alkyl group is preferably 6 or less, more preferably 3 or less, and even more preferably 1 or 2.

[0087] In the substituted alkyl group having 10 or less carbon atoms, examples of the substituent include a hydroxy group, a carboxy group, an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylthioether group, an arylthioether group, a heteroarylthioether group, and a (meth)acryloyl group. Among these, from the viewpoint of the storage stability of the pretreatment liquid, the substituent is preferably a hydroxy group, an aryl group, or a (meth)acryloyl group, and more preferably a hydroxy group.

[0088] The quaternary ammonium cation is preferably contained in the pretreatment liquid as a quaternary ammonium salt. Examples of the counter anion in the quaternary ammonium salt include Cl. － ,Br － , I － halide ions such as those mentioned above; organic sulfonate anions having a substituent selected from an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aralkyl group, and a heterocyclic group; PF ６ － and BF ４ － From the viewpoint of solubility in the pretreatment solution, the counter anion is Cl. － ,Br － or a sulfonate anion having an alkyl group is preferred, and Cl － or Br － More preferably, Cl － is more preferable.

[0089] Among these, the quaternary ammonium cation is preferably at least one selected from the group consisting of diallyldimethylammonium cation, (2-hydroxyethyl)trimethylammonium cation, and N-(2-acryloyloxyethyl)-N-benzyl-N,N-dimethylammonium cation, and more preferably at least one selected from the group consisting of diallyldimethylammonium cation and (2-hydroxyethyl)trimethylammonium cation.

[0090] The flocculant preferably contains a polyvalent metal salt from the viewpoint of further improving the flexibility of the printed textile.

[0091] When the pretreatment liquid contains a flocculant, the content of the flocculant is preferably 1% by mass to 25% by mass, more preferably 2% by mass to 20% by mass, and even more preferably 5% by mass to 15% by mass, relative to the total amount of the pretreatment liquid. When the content of the flocculant is within the above range, penetration of the ink into the interior of the printed item is suppressed, and the degree of freedom of movement of the yarn in the printed item is improved, resulting in further improved flexibility of the printed item.

[0092] (Compound (A)) The pretreatment liquid preferably contains a compound (A) represented by the following formula (A). This further improves the softness of the printed textile. The reason for this effect is thought to be that when the pretreatment liquid contains compound (A), frictional resistance between threads in the weave is reduced, making it easier for the threads to move freely. The pretreatment liquid may contain only one type of compound (A), or two or more types of compound (A).

[0093]

[0094] In formula (A), m is an integer of 11 or more, and n is an integer of 12 or more.

[0095] In formula (A), m is preferably 16 or more, more preferably 16 to 18, and even more preferably 18. In formula (A), n is preferably 13 or more, more preferably 13 to 50, and even more preferably 13 to 25.

[0096] Examples of compound (A) include polyoxyethylene (20) stearyl ether (a compound in which m is 18 and n is 20 in formula (A)), polyoxyethylene (13) cetyl-stearyl ether (a compound in which m is a mixture of 16 to 18 and n is 13 in formula (A)), polyoxyethylene (13) stearyl ether (a compound in which m is 18 and n is 13 in formula (A)), polyoxyethylene (50) stearyl ether (a compound in which m is 18 and n is 50 in formula (A)), and the like.

[0097] When the pre-treatment liquid contains the compound (A), the content of the compound (A) is preferably 0.01% by mass to 3.00% by mass, more preferably 0.02% by mass to 1.00% by mass, and even more preferably 0.03% by mass to 0.50% by mass, relative to the total amount of the pre-treatment liquid.

[0098] (Surfactant) The pre-treatment liquid preferably contains at least one surfactant. There are no particular restrictions on the surfactant, and known surfactants such as silicone-based surfactants, fluorine-based surfactants, and acetylene glycol-based surfactants can be used. When the pre-treatment liquid contains a surfactant, the content of the surfactant is preferably 0.05% by mass to 2.00% by mass, and more preferably 0.10% by mass to 2.00% by mass, relative to the total amount of the pre-treatment liquid.

[0099] (Resin) The pretreatment liquid preferably contains at least one resin. The resin may be a water-soluble resin or a water-insoluble resin. In a water-containing pretreatment liquid, the water-insoluble resin may form resin particles. This type of pretreatment liquid may be prepared using a latex, which is an aqueous dispersion of resin particles.

[0100] Here, "water-insoluble" in the case of a water-insoluble resin means that the amount of the resin that dissolves in 100 g of distilled water at 25°C is less than 2 g, and "water-soluble" in the case of a water-soluble resin means that the amount of the resin that dissolves in 100 g of distilled water at 25°C is 2 g or more.

[0101] The volume average particle size of the resin particles is preferably 1 nm to 300 nm, more preferably 3 nm to 200 nm, and even more preferably 5 nm to 150 nm.

[0102] In the present disclosure, the volume average particle size refers to a value measured using a laser diffraction / scattering particle size distribution analyzer. Examples of the measuring device include a particle size distribution analyzer "Microtrac MT-3300II" (manufactured by Nikkiso Co., Ltd.).

[0103] Examples of the resin particles include urethane resin particles, acrylic resin particles, and ester resin particles. For details of the resin particles, see, for example, paragraphs 0038 to 0114 of International Publication No. 2021 / 192720 and paragraphs 0109 to 0120 of JP-A-2015-25076.

[0104] When the pretreatment liquid contains a resin, the content of the resin is preferably 1.0% by mass to 20.0% by mass, more preferably 1.0% by mass to 15.0% by mass, and even more preferably 1.0% by mass to 10.0% by mass, relative to the total amount of the pretreatment liquid. When the resin content is 20.0% by mass or less, the flexibility of the printed material can be further improved. When the resin content is 1.0% by mass or more, the adhesion between fibers in the printed material can be further improved.

[0105] (Other Components) The pretreatment liquid may contain other components in addition to the above components, such as a pH adjuster, a fluorescent brightener, a surface tension adjuster, an antifoaming agent, an anti-drying agent, a lubricant, a thickener, an ultraviolet absorber, an anti-fading agent, an antistatic agent, a matting agent, an antioxidant, a resistivity adjuster, a rust inhibitor, an anti-reducing agent, an antiseptic, an anti-fungal agent, and a chelating agent.

[0106] [Textile Printing Method] The textile printing method of the present disclosure includes an ink application step of applying the ink of the present disclosure to a fabric.

[0107] (Ink application step) In the ink application step, the method for applying the ink to the fabric is not particularly limited, and examples thereof include a coating method, a padding method, an inkjet method, a spray method, and a screen printing method. Among these, the ink application method is preferably an inkjet method from the viewpoint of improving the texture of the resulting printed textile. That is, in the ink application step, it is preferable to apply the ink by an inkjet method.

[0108] The inkjet method can be a commonly known method, and examples thereof include a charge control method that uses electrostatic attraction to eject ink, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the ink, thereby ejecting the ink using radiation pressure, and a thermal inkjet method that heats the ink to form bubbles and uses the resulting pressure.

[0109] Generally, image recording methods using inkjet recording devices include a shuttle scan method (also known as a "serial head method"), which uses a short serial head to record an image, and a single-pass method (also known as a "line head method"), which uses a line head in which recording elements are arranged across the entire width of the recording medium. In the shuttle scan method, an image is recorded by scanning the serial head across the width of the recording medium. In contrast, in the single-pass method, an image can be recorded across the entire surface of the recording medium by scanning the recording medium in a direction perpendicular to the direction of the recording element arrangement. Therefore, unlike the shuttle scan method, the single-pass method does not require a transport system such as a carriage to scan the serial head. Furthermore, the single-pass method does not require complex scanning control of the carriage movement and the recording medium, and only the recording medium moves, allowing for faster recording speeds compared to the shuttle scan method.

[0110] The inkjet recording method is preferably performed in a single pass. According to the textile printing method of the present disclosure, even when performed in a single pass, it is possible to obtain a printed product having excellent rub fastness and flexibility.

[0111] The droplet volume of ink ejected from the inkjet head is preferably 1 pL (picoliter) to 150 pL, more preferably 2 pL to 120 pL, and particularly preferably 20 pL to 60 pL. Note that droplet volume refers to the volume of ink ejected from one nozzle at a time by the inkjet method.

[0112] The amount of ink applied is 10 g / m from the viewpoint of texture. ２ ~30g / m ２It is preferable that the density is 15 g / m ２ ~25g / m ２ is.

[0113] The ink ejection resolution is preferably 200 dpi or more × 200 dpi or more, and more preferably 400 dpi or more × 400 dpi or more, and 1200 dpi or less × 1200 dpi or less. In the present disclosure, dpi is an abbreviation for dots per inch.

[0114] (Pretreatment Liquid Application Step) The textile printing method of the present disclosure may include a pretreatment liquid application step of applying a pretreatment liquid to the fabric prior to the ink application step. In this case, in the ink application step, ink is applied to the area of ​​the fabric to which the pretreatment liquid has been applied. Preferred aspects of the pretreatment liquid are the same as those of the pretreatment liquid in the textile printing ink set.

[0115] That is, one embodiment of the textile printing method of the present disclosure is a textile printing method that uses the above-described textile printing ink set of the present disclosure, and includes: a pretreatment liquid application step of applying a pretreatment liquid to a fabric; and an ink application step of applying a printing ink to an area of ​​the fabric to which the pretreatment liquid has been applied.

[0116] Examples of methods for applying the pretreatment liquid to the fabric are the same as the above-mentioned examples of methods for applying ink to the fabric, and the preferred embodiments are also the same.

[0117] (Corona Discharge Treatment Step) The textile printing method of the present disclosure may include a step of subjecting the fabric to corona discharge treatment (hereinafter also referred to as corona treatment) before the ink application step. In this case, in the ink application step, ink is applied to the corona-treated area of ​​the fabric. The corona discharge treatment can be performed by a conventional method using a known corona treatment device.

[0118] (Heat Treatment Step) The textile printing method of the present disclosure preferably includes, after the ink application step, a heat treatment step of heat treating the fabric to which the ink has been applied at a temperature of 100° C. or higher.

[0119] Examples of heat treatment devices for carrying out the heat treatment step include a heat drum, hot air, an infrared lamp, a heat oven, a heat plate, a heat press, and a hot plate. The heating temperature in the heat treatment is preferably 100° C. to 180° C., and more preferably 120° C. to 170° C. The heating time in the heat treatment is preferably 5 seconds to 200 seconds, and more preferably 30 seconds to 160 seconds.

[0120] The textile printing method of the present disclosure may include other steps in addition to the steps described above, such as a step of forming a resin layer (a so-called overcoat layer) on the ink-applied region (i.e., image) of the fabric after the heat treatment step by applying an overcoat liquid, for example.

[0121] The present disclosure will be described in more detail below using examples, but the present disclosure is not limited to the following examples as long as it does not deviate from the gist of the disclosure. Hereinafter, "%" means "mass %" unless otherwise specified. Hereinafter, "polyurethane" means urethane resin.

[0122] Examples 1 to 15, Comparative Examples 1 to 3 <Ink Preparation Method> [Preparation of Prepolymer Solution 1 (PP-1)] A three-necked flask was charged with 30.00 g of hexamethylene diisocyanate (HDI), 10.52 g of 2,2-dimethylolpropionic acid (DMPA), 91.04 g of polycarbonate diol (product name "DURANOL (registered trademark) T5651", manufactured by Asahi Kasei Chemicals Corporation), and 89.55 g of methyl ethyl ketone, and the mixture was heated to 50° C. Duranol (registered trademark) T5651 is the following compound (2-18)PC in which Rc1 and Rc2 are each an alkylene group having 5 or 6 carbon atoms, and Mn is 1,000.

[0123]

[0124] [Preparation of Polyurethane 1 Aqueous Solution (PU-1)] 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) was diluted with 2.00 g of methyl ethyl ketone and added to prepolymer solution 1 (PP-1), and the mixture was stirred at 80 ° C. for 6 hours. Furthermore, 32.15 g of isopropyl alcohol and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 70 ° C. for 3 hours. The reaction solution after the stirring was allowed to cool to room temperature (23 ° C.). 128 g of methyl ethyl ketone was added to adjust the concentration, thereby obtaining a 30 mass% solution of polyurethane (solvent: a mixed solution of methyl ethyl ketone / isopropyl alcohol). Note that a portion of the isopropyl alcohol reacted with the isocyanate terminal of the polyurethane to form an isopropyl terminal. The weight average molecular weight of the polyurethane was as shown in Table 2. A three-neck flask was charged with 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA, and the mixture was stirred for 10 minutes. Next, 118.26 g of water was added, and the mixture was stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding a 30% aqueous solution of polyurethane 1 (PU-1).

[0125] [Preparation of Polyurethane 2 Aqueous Solution (PU-2)] 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) was diluted with 2.00 g of methyl ethyl ketone and added to prepolymer solution 1 (PP-1), followed by stirring at 80°C for 12 hours. Furthermore, 32.15 g of isopropyl alcohol and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 80°C for 3 hours. The reaction solution after stirring was allowed to cool to room temperature (23°C). 128 g of methyl ethyl ketone was added to adjust the concentration, yielding a 30% by mass solution of polyurethane (solvent: a mixed solution of methyl ethyl ketone / isopropyl alcohol). Note that a portion of the isopropyl alcohol reacted with the isocyanate terminal of the polyurethane to form isopropyl terminals. The weight average molecular weight of the polyurethane was as shown in Table 2. A three-neck flask was charged with 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA, and the mixture was stirred for 10 minutes. Next, 118.26 g of water was added, and the mixture was stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding a 30% aqueous solution of polyurethane 2 (PU-2).

[0126] [Preparation of Polyurethane 3 Aqueous Solution (PU-3)] 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) diluted with 2.00 g of methyl ethyl ketone was added to Prepolymer Solution 1 (PP-1) and stirred at 70°C for 5 hours. Furthermore, 39.66 g of 1-butanol and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 70°C for 2 hours. The reaction solution after stirring was allowed to cool to room temperature (23°C). 121 g of methyl ethyl ketone was added to adjust the concentration, yielding a 30% by mass solution of polyurethane (solvent: a mixed solution of methyl ethyl ketone / 1-butanol). Note that a portion of the 1-butanol reacted with the isocyanate terminal of the polyurethane to form n-butyl terminals. The weight-average molecular weight of the polyurethane was as shown in Table 2. A three-neck flask was charged with 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA, and the mixture was stirred for 10 minutes. Next, 118.26 g of water was added, and the mixture was stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding a 30% aqueous solution of polyurethane 3 (PU-3).

[0127] [Preparation of Polyurethane 4 Aqueous Solution (PU-4)] 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) was diluted with 2.00 g of methyl ethyl ketone and added to prepolymer solution 1 (PP-1), and the mixture was stirred at 70 ° C. for 5 hours. Furthermore, 32.15 g of isopropyl alcohol and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 70 ° C. for 2 hours. The reaction solution after the stirring was allowed to cool to room temperature (23 ° C.). 128 g of methyl ethyl ketone was added to adjust the concentration, thereby obtaining a 30 mass% solution of polyurethane (solvent: a mixed solution of methyl ethyl ketone / isopropyl alcohol). Note that a portion of the isopropyl alcohol reacted with the isocyanate terminal of the polyurethane to form an isopropyl terminal. The weight average molecular weight of the polyurethane was as shown in Table 3. A three-neck flask was charged with 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA, and the mixture was stirred for 10 minutes. Next, 118.26 g of water was added, and the mixture was stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding a 30% aqueous solution of polyurethane 4 (PU-4).

[0128] [Preparation of Polyurethane 5 Aqueous Solution (PU-5)] (Comparative Example 1) 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) diluted with 2.00 g of methyl ethyl ketone was added to prepolymer solution 1 (PP-1) and stirred at 70°C for 5 hours. Furthermore, 9.63 g of ultrapure water and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 70°C for 2 hours. The reaction solution after stirring was allowed to cool to room temperature (23°C). 151 g of methyl ethyl ketone was added to adjust the concentration, yielding a 30% by mass solution of polyurethane (solvent: methyl ethyl ketone). Note that a portion of the ultrapure water reacted with the isocyanate terminals of the polyurethane, forming amine terminals through hydrolysis and decarboxylation. The weight-average molecular weight of the polyurethane was as shown in Table 2. A three-neck flask was charged with 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA, and the mixture was stirred for 10 minutes. Next, 118.26 g of water was added, and the mixture was stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding a 30% aqueous solution of polyurethane 5 (PU-5).

[0129] [Preparation of Polyurethane 6 Aqueous Solution (PU-6)] (Comparative Example 2) 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) was diluted with 2.00 g of methyl ethyl ketone and added to prepolymer solution 1 (PP-1), and the mixture was stirred at 70 ° C. for 3 hours. Furthermore, 32.15 g of isopropyl alcohol and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 70 ° C. for 2 hours. The reaction solution after the stirring was allowed to cool to room temperature (23 ° C.). 128 g of methyl ethyl ketone was added to adjust the concentration, thereby obtaining a 30 mass% solution of polyurethane (solvent: a mixed solution of methyl ethyl ketone / isopropyl alcohol). Note that a portion of the isopropyl alcohol reacted with the isocyanate terminal of the polyurethane to form an isopropyl terminal. The weight average molecular weight of the polyurethane was as shown in Table 2. A three-neck flask was charged with 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA, and the mixture was stirred for 10 minutes. Next, 118.26 g of water was added, and the mixture was stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding a 30% aqueous solution of polyurethane 6 (PU-6).

[0130] [Preparation of Polyurethane 7 Aqueous Solution (PU-7)] (Comparative Example 3 (Branched Chain)) To the prepolymer solution 1 (PP-1), 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) was diluted with 2.00 g of methyl ethyl ketone and added, and the mixture was stirred at 70 ° C. for 2 hours. Furthermore, 2.15 g of trimethylolpropane, 30.0 g of isopropyl alcohol, and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 70 ° C. for 3 hours. The reaction solution after the stirring was allowed to cool to room temperature (23 ° C.). By adding 128 g of methyl ethyl ketone to adjust the concentration, a 30 mass% solution of polyurethane (solvent: a mixed solution of methyl ethyl ketone / isopropyl alcohol) was obtained. Note that a portion of the isopropyl alcohol reacted with the isocyanate terminal of the polyurethane to form an isopropyl terminal. The weight average molecular weight of the polyurethane was difficult to measure due to its low solubility in the measurement solvent used for molecular weight measurement (shown as "-" in Table 2). 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA were charged into a three-neck flask and stirred for 10 minutes. Next, 118.26 g of water was added and stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding a 30% aqueous solution of polyurethane 7 (PU-7).

[0131] Polyurethane 7 is a branched-chain urethane resin made from the raw materials trimethylolpropane, a triol, and 2,2-dimethylolpropionic acid, a diol. The polyurethanes other than Polyurethane 7 are linear urethane resins made from the raw material diol 2,2-dimethylolpropionic acid.

[0132] [Preparation of Prepolymer Solutions 2 to 7 (PP-2 to PP-7)] A three-neck flask was charged with the diisocyanate, diol, and 89.55 g of methyl ethyl ketone in the amounts shown in the table below, and heated to 50°C.

[0133]

[0134] In the table, components that are not contained are marked with "-". DMPA: 2,2-dimethylolpropionic acid TCD: tricyclodecane dimethanol PCD1000: polycarbonate diol (product name "Duranol (registered trademark) T5651", manufactured by Asahi Kasei Chemicals Corporation) PEG1000: polyethylene glycol 1000 IPDI: isophorone diisocyanate HMDI: hexamethylene diisocyanate

[0135] [Preparation of Polyurethane Aqueous Solutions 8 to 14 (PU-8 to PU-14)] To each of prepolymer solutions 2 to 8 (PP-2 to PP-8), 0.1973 g of an inorganic bismuth catalyst (product name "Neostan U-600" manufactured by Nitto Kasei Co., Ltd.) was diluted with 2.00 g of methyl ethyl ketone and added, followed by stirring at 70 ° C for 5 hours. Furthermore, 32.15 g of isopropyl alcohol and 55.56 g of methyl ethyl ketone were added, and the mixture was stirred at 70 ° C for 2 hours. The reaction solution after stirring was allowed to cool to room temperature (23 ° C). 128 g of methyl ethyl ketone was added to adjust the concentration, resulting in a 30 mass% polyurethane solution (solvent: a mixed solution of methyl ethyl ketone / isopropyl alcohol). Note that a portion of the isopropyl alcohol reacted with the isocyanate terminal of the polyurethane to form an isopropyl terminal. The weight average molecular weight of the polyurethane was the molecular weight listed in the table. A three-neck flask was charged with 150.0 g of the polyurethane solution, 18.24 g of methyl ethyl ketone, and 1.745 g of DIPEA, and the mixture was stirred for 10 minutes. Next, 118.26 g of water was added, and the mixture was stirred for 30 minutes. The mixture was then heated and stirred at 55°C, and the methyl ethyl ketone was removed by heating until the liquid volume reached 150 g, yielding 30% aqueous solutions of polyurethanes 8 to 14 (PU-8 to PU-14).

[0136] [Ink Preparation] The following components were mixed to prepare inks. Hereinafter, the "content (% by mass)" of ink components refers to the content (% by mass) relative to the total amount of ink. - "APD4000 Black" (manufactured by Fujifilm Imaging Colorants Ltd.) (pigment dispersion) ... the content (% by mass) shown in Table 2 as the pigment content - Organic solvent shown in Table 2 ... the content (% by mass) shown in Table 2 - Urethane resin shown in Table 2 ... the content (% by mass) shown in Table 2 as the solid content (urethane resin) - "Surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.) (surfactant) ... the content (% by mass) shown in Table 2 - "Snowtex (registered trademark) XS" (manufactured by Nissan Chemical Industries, Ltd.) (colloidal silica dispersion) ... 0.05% by mass as the colloidal silica particle (i.e., solid content) content - Water ... the remaining amount to make the total ink 100% by mass

[0137] Tables 2 and 3 show the types and contents of the urethane resin, organic solvent, surfactant, and colloidal silica in the ink.

[0138] [Preparation of Pretreatment Liquid] The following components were mixed to prepare a pretreatment liquid. Hereinafter, the "content (% by mass)" of a component in the pretreatment liquid refers to the content (% by mass) relative to the total amount of the pretreatment liquid. - Flocculant listed in Table 2 or Table 3...content (% by mass) shown in Table 2 or Table 3 - "Movinyl 966A" (latex (aqueous dispersion of resin particles)) manufactured by Japan Coating Resins Co., Ltd....content (% by mass) shown in Table 2 or Table 3 as the content of solids (resin particles) - Polyoxyethylene (20) stearyl ether as compound (A)...content (% by mass) shown in Table 2 or Table 3 - "Surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.) as a surfactant...content (% by mass) shown in Table 2 or Table 3 - Water...the remaining amount to make the total ink 100% by mass

[0139] Tables 2 and 3 show the types and contents of the flocculant, resin particles, compound (A) represented by formula (A), and surfactant in the pretreatment liquid. Details of the flocculant listed in Table 2 or Table 3 are as follows: The cationic polymer was Catiomaster (registered trademark) PD (PD-7) (amine-epichlorohydrin condensation polymer) manufactured by Yokkaichi Synthetic Co., Ltd. Calcium nitrate tetrahydrate was used as calcium nitrate. The contents (mass%) listed in the tables refer to the mass% of calcium nitrate excluding hydrated components. Calcium chloride dihydrate was used as calcium chloride. The contents (mass%) listed in the tables refer to the mass% of calcium chloride excluding hydrated components.

[0140] [Preparation of Fabric] As the fabric, an A4 sheet (30 cm x 21 cm) of 100% cotton fabric (product name "Cotton D5005", manufactured by Akahori Sangyo Co., Ltd.) was prepared.

[0141] [Application of Pretreatment Liquid (Other than Examples 17 and 18)] The pretreatment liquids prepared in the Examples (except Examples 17 and 18) and Comparative Examples were impregnated into fabrics by padding, then wrung out at a wringing rate of 70% and dried for 24 hours. The resulting fabrics are hereinafter also referred to as "pretreated fabrics." Here, the wringing rate (%) represents the amount (mass ratio) of the pretreatment liquid remaining on the fabric after the fabric containing the pretreatment liquid was wrung out.

[0142] [Ink Application] An inkjet recording apparatus equipped with an inkjet head (product name "StarFire SG-1024SA", manufactured by Fujifilm Dimatix) and an ink circulation pump was prepared. As a recording medium, a pretreated fabric was fixed on a stage (however, in Examples 17 and 18, an unpretreated fabric was fixed on the stage). An ink tank connected to the inkjet head was filled with the textile printing ink of the Examples and Comparative Examples. The inkjet heads were arranged in a line with the nozzles aligned in a direction perpendicular to the direction of stage movement. The ink ejection conditions were a droplet volume of 49.5 pL, an ejection frequency of 10 kHz, a resolution of 400 dpi x 400 dpi, and an ink application amount per fabric area of ​​12.3 g / m. ２An ink circulation pump was operated so that the ink circulated between the ink tank and the inkjet head. Under these conditions, the ink was ejected onto the recording medium to record an image, thereby obtaining a colored fabric.

[0143] [Heat Treatment (Heat Press)] The obtained colored fabric was heat treated at 160° C. for 120 seconds using a heat press (automatic tabletop flat press AF-54TEN model, manufactured by Asahi Seni Kikai Co., Ltd.) to obtain a printed item.

[0144] [Evaluation] The printed textiles (hereinafter also referred to as evaluation samples) and inks obtained above were evaluated as follows. The results are shown in Tables 2 and 3.

[0145] <Rubbing Fastness> A rubbing test was carried out on the printed textile obtained above in accordance with ISO 105X12:2001 (wet), and the L*a*b* of the color-adhered portion on the rubbing cloth was measured using a spectrodensitometer (FD-7 manufactured by Konica Minolta, Inc.). The discoloration ΔE of the rubbing cloth before and after rubbing was calculated, and the rubbing fastness of the printed textile was evaluated based on the following evaluation criteria. In the following evaluation criteria, the most excellent rank for rubbing fastness of the printed textile is S.

[0146] - Evaluation criteria for rub fastness - S: ΔE is less than 10. AA: ΔE is 10 or more and less than 12.5. A: ΔE is 12.5 or more and less than 15. B: ΔE is 15 or more and less than 20. C+: ΔE is 20 or more and less than 22.5. C: ΔE is 22.5 or more and less than 25. D: ΔE is 25 or more.

[0147] <Flexibility> A white cloth of the same size as the printed fabric (hereinafter also referred to as the evaluation sample) obtained above, but before application of the pretreatment liquid and ink, was prepared as a reference white cloth sample. A stainless steel plate with a length (long side) of 200 mm, a width (short side) of 100 mm, and a thickness of 1 mm was prepared as the evaluation jig. The evaluation jig was set upright with the short side oriented vertically and the long side oriented horizontally. Next, the longitudinal center (i.e., the centerline) of the evaluation sample was placed on the horizontal long side of the evaluation jig, so that both longitudinal ends (both ends) of the evaluation sample drooped. In this state, the linear distance between one longitudinal end and the other longitudinal end of the evaluation sample was measured, and this was taken as the deflection distance. The deflection distance was also measured for the reference white cloth sample in the same manner. The flexibility of the printed textile was evaluated based on the Δ deflection distance, which is the difference between the deflection distance of the evaluation sample and the deflection distance of the reference white cloth sample, according to the following evaluation criteria: In the following evaluation criteria, the most excellent rank for the flexibility of the printed textile is AA.

[0148] - Flexibility evaluation criteria - AA: The Δ deflection distance is less than 3 mm. A: The Δ deflection distance is 3 mm or more and less than 5 mm. B+: The Δ deflection distance is 5 mm or more and less than 9 mm. B: The Δ deflection distance is 9 mm or more and less than 12 mm. C: The Δ deflection distance is 12 mm or more and less than 20 mm. D: The Δ deflection distance is 20 mm or more.

[0149] <Breaking elongation of pigment resin mixed film> A pigment resin mixed film was produced by adding a liquid amount of ink to give a film thickness equivalent to 0.5 mm in solid content to a Teflon (registered trademark) coated omelet pan measuring 33.6 cm wide x 13.5 cm deep, and drying for 48 hours at 25° C., 18 hours at 80° C., and 6 hours at 120° C. The produced pigment resin mixed film was cut to a length of 5 cm x width of 1 cm, and the cut film was gripped by 1 cm on both ends with a Tensilon so that the gripping distance was 3 cm, and a tensile test was carried out at a pulling rate of 30 mm / min until breakage, and the breaking elongation was measured.

[0150] (Example 16) The same operation as in Example 15 was carried out, except that the pretreated fabric was subjected to a corona treatment using a corona treatment device (TEC-8XA, manufactured by Kasuga Electric Co., Ltd., set output 100 W, operating speed 1 m / min, number of treatments: 1 time) before being fixed on the stage. The results are shown in Table 3.

[0151] Example 17 The same operation as in Example 15 was performed, except that the fabric was changed to an A4 sheet (30 cm x 21 cm) of 100% polyester fabric (product name "Karui Dry <SS-755>", manufactured by Masuda Co., Ltd.) and that no pretreatment liquid was applied to the fabric. The results are shown in Table 3.

[0152] Example 18 The same procedure as in Example 17 was carried out, except that the fabric was subjected to a corona treatment using a corona treatment device (TEC-8XA, manufactured by Kasuga Electric Co., Ltd., set output 100 W, operating speed 1 m / min, number of treatments: 1 time) before being fixed on the stage. The results are shown in Table 3.

[0153]

[0154]

[0155] As shown in Tables 2 and 3, in Examples 1 to 18, which used textile printing inks containing a pigment and a urethane resin having a weight-average molecular weight of 50,000 or more, where the urethane resin was a linear urethane resin in which the terminal group of the molecular chain was an alkyl group having 1 to 6 carbon atoms, the resulting printed textiles had excellent rub fastness and flexibility. In comparison with these Examples, the results of the comparative examples were as follows. In Comparative Example 1, in which the terminal group of the molecular chain of the urethane resin in the textile printing ink was a group other than an alkyl group having 1 to 6 carbon atoms, the printed textile had low flexibility. In Comparative Example 2, in which the weight-average molecular weight of the urethane resin in the textile printing ink was less than 50,000, the printed textile had low rub fastness. In Comparative Example 3, in which the urethane resin in the textile printing ink was a branched urethane resin rather than a linear urethane resin, the printed textile had low flexibility.

[0156] The results of Examples 4 to 10 show that when the proportion of ring structures in the urethane resin in the textile printing ink is 25 mass % or less (Examples 6 to 10), the flexibility of the printed textile is superior.

[0157] The results of Examples 4 to 10 show that when the ClogP of the urethane resin in the textile printing ink is 2.0 or more (Examples 5, 9, and 10), the rub fastness of the printed textile is superior.

[0158] The results of Examples 11 to 15 show that when a pretreatment liquid is used and the pretreatment liquid contains a flocculant (Examples 12 to 15), the flexibility of the image is superior.

[0159] The results of Examples 12 to 15 show that when a pre-treatment liquid is used and the pre-treatment liquid contains the compound (A) represented by formula (A) (Examples 13 to 15), the flexibility of the image is superior.

[0160] The results of Examples 13 to 15 show that when a pretreatment liquid is used and the pretreatment liquid contains a flocculant that is a polyvalent metal salt (Examples 13 and 15), the flexibility of the image is superior.

[0161] The results of Examples 15 and 16 (both with a pretreatment liquid) show that when the fabric was subjected to a corona discharge treatment before ink application (Example 16), the rub fastness of the image was further improved. Similarly, the results of Examples 17 and 18 (both without a pretreatment liquid) show that when the fabric was subjected to a corona discharge treatment before ink application (Example 18), the rub fastness of the image was further improved.

[0162] Furthermore, as shown in Tables 2 and 3, Examples 1 to 18, which used inks containing a linear urethane resin having a weight-average molecular weight of 50,000 or more and in which the terminal group of the molecular chain is an alkyl group having 1 to 6 carbon atoms, exhibited superior breaking elongation of the pigment-resin mixed film formed using the ink, even when compared to Comparative Example 1, in which the terminal group of the molecular chain of the urethane resin in the ink is a group other than an alkyl group having 1 to 6 carbon atoms; Comparative Example 2, in which the weight-average molecular weight of the urethane resin in the ink is less than 50,000; and Comparative Example 3, in which the urethane resin in the ink is a branched urethane resin rather than a linear urethane resin. This demonstrates that, in textile prints using the inks of each Example, a stress relaxation effect can be achieved when the ink application amount is increased to increase the ink film thickness. As a result, it is expected that excellent abrasion fastness can be achieved even when the ink application amount is increased. In fact, in Example 15 (ink application amount of 12.3 g / m), ２ , ink film thickness 0.5 μm) and the ink application amount was 30 g / m ２ The ink film thickness was increased to 1.54 μm to produce the print of Example 19. As a result, the print of Example 19 achieved a rub fastness of rank "S" (Example 15 achieved a rank "A").

[0163] The disclosure of Japanese Patent Application No. 2024-048725, filed on March 25, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A textile printing ink comprising a pigment and a urethane resin having a weight average molecular weight of 50,000 or more, wherein the urethane resin is a reaction product of a diol, a diisocyanate, and a monoalcohol having 1 to 6 carbon atoms, and is a linear urethane resin whose molecular chain terminal group is an alkyl group having 1 to 6 carbon atoms.

2. The textile printing ink according to claim 1, wherein the proportion of ring structures in the urethane resin is 25% by mass or less.

3. The textile printing ink according to claim 1, wherein the urethane resin has a ClogP of 2.0 or more.

4. A textile printing ink set comprising the textile printing ink according to claim 1 and a pretreatment liquid containing a flocculant and water.

5. The textile printing ink set according to claim 4, wherein the flocculant contains a polyvalent metal salt.

6. The textile printing ink set according to claim 4, wherein the pretreatment liquid further contains a compound (A) represented by the following formula (A): In formula (A), m is an integer of 11 or more, and n is an integer of 12 or more.

7. A textile printing method comprising an ink application step of applying the textile printing ink according to claim 1 to a fabric.

8. A textile printing method using the textile printing ink set according to claim 4, comprising: a pretreatment liquid application step of applying the pretreatment liquid to a fabric; and an ink application step of applying the textile printing ink to the area of ​​the fabric to which the pretreatment liquid has been applied.

9. The textile printing method according to claim 7 or 8, wherein the ink applying step applies the textile printing ink by an inkjet method.

10. The textile printing method according to claim 7 or 8, further comprising a step of subjecting the fabric to a corona discharge treatment before the ink application step.

Images