Inkjet ink composition for textile printing

Abstract

Provided is an inkjet ink composition for textile printing, which has good viscosity stability and is excellent in terms of density, fastness and texture of printed matter. Specifically provided is an inkjet ink composition for textile printing, which contains at least carbon black, a water-dispersible resin, and water, wherein: the carbon black contains self-dispersible carbon black; the water-dispersible resin contains at least one type of water-dispersible urethane resin that is selected from the group consisting of a polyether-based polyurethane, a polyester-based polyurethane, and a polycarbonate-based polyurethane; the water-dispersible urethane resin has an elongation at break of 700% to 1,700% and a tensile strength of 30 MPa or less; and the content of the water-dispersible urethane resin is 100 parts by mass to 300 parts by mass in terms of solid content with respect to 100 parts by mass of the carbon black.

Description

Inkjet ink composition for textile printing

[0001] The present invention relates to an inkjet ink composition for textile printing.

[0002] BACKGROUND ART A method of printing a fabric by inkjet printing with an ink containing a pigment is known.

[0003] For example, Patent Document 1 discloses an inkjet ink for textile printing that contains a pigment, a water-dispersible resin, a crosslinking agent, and water, wherein the water-dispersible resin is a resin having a breaking elongation of 1200 to 1800% and a tensile strength of 10 to 48 MPa in an amount of 1.0 to 3.0 parts by mass per part by mass of the pigment, and the crosslinking agent is 0.03 to 0.17 parts by mass per part by mass of the water-dispersible resin. It also discloses that printed materials (printed materials) printed with this inkjet ink for textile printing have excellent fastness and texture.

[0004] Japanese Patent Application Laid-Open No. 2019-031611

[0005] Textile printing by inkjet printing using an ink composition containing a pigment tends to produce printed matter with a lower density than ink compositions containing a dye, but inks containing pigments have the advantage of being superior in fastness.

[0006] On the other hand, a technique of using a pretreatment agent to increase the concentration of an ink composition containing a pigment is known, but it is difficult to achieve a balance with fastness, which leads to increased costs and reduced productivity. Therefore, there has been a demand for an ink composition containing a pigment for inkjet textile printing that can produce printed products with good concentration without using a pretreatment agent.

[0007] Furthermore, from the viewpoint of ejection properties in ink jet printing, ink compositions for textile printing are required to have a property of maintaining a constant viscosity (viscosity stability).

[0008] Therefore, an object of the present invention is to provide an inkjet ink composition for textile printing that not only provides excellent fastness and texture to printed matter (printed matter), but also provides excellent density in the printed matter and viscosity stability of the ink composition.

[0009] The present invention provides an inkjet ink composition for textile printing, which contains at least carbon black, a water-dispersible resin, and water, wherein the carbon black contains self-dispersible carbon black, the water-dispersible resin contains at least one water-dispersible urethane resin selected from the group consisting of polyether-based polyurethanes, polyester-based polyurethanes, and polycarbonate-based polyurethanes, the water-dispersible urethane resin has a breaking elongation of 700% or more and 1700% or less and a tensile strength of 30 MPa or less, and the content of the water-dispersible urethane resin is 100 parts by mass or more and 300 parts by mass or less in terms of solid content per 100 parts by mass of the carbon black.

[0010] In the inkjet textile printing ink composition of the present invention, the carbon black preferably further contains resin-dispersed carbon black, and the mass ratio of the self-dispersed carbon black to the resin-dispersed carbon black is preferably 1:5 to 5:1.

[0011] The present invention can provide an inkjet ink composition for textile printing that has good viscosity stability and produces printed products with excellent density, fastness, and texture.

[0012] The inkjet ink composition for textile printing of the present invention is an inkjet ink composition for textile printing that contains at least carbon black, a water-dispersible resin, and water, wherein the carbon black contains self-dispersible carbon black, the water-dispersible resin contains at least one water-dispersible urethane resin selected from the group consisting of polyether-based polyurethanes, polyester-based polyurethanes, and polycarbonate-based polyurethanes, and the water-dispersible urethane resin has a breaking elongation of 700% or more and 1,700% or less and a tensile strength of 30 MPa or less, and contains 100 parts by mass or more and 300 parts by mass or less of the water-dispersible urethane resin in terms of solid content per 100 parts by mass of the carbon black.

[0013] The inkjet ink composition for textile printing of the present invention (hereinafter also referred to as the ink composition of the present invention) uses self-dispersible carbon black to obtain good density of printed matter, while optimizing the amount of water-dispersible resin having specific physical properties added makes it possible to achieve both fastness and texture of printed matter and storage stability of the ink composition. However, the present invention does not need to be interpreted as being limited to the above mechanism.

[0014] (Carbon Black) The ink composition of the present invention contains carbon black.

[0015] The carbon black contains self-dispersible carbon black. By containing the self-dispersible carbon black and a specific water-dispersible urethane resin, it is possible to obtain an ink composition that has good viscosity stability and that produces printed matter with excellent density, fastness, and texture. The self-dispersible carbon black is carbon black that can be dispersed in water without the use of a pigment dispersant by chemically treating the surface of the carbon black to add hydrophilic functional groups such as carboxyl groups and phosphate groups.

[0016] Examples of the self-dispersing carbon black include carbon black having at least one hydrophilic group, such as a carbonyl group, a hydroxyl group, a carboxyl group, a sulfo group, or a phosphate group, or a salt thereof, introduced onto the surface of the carbon black by chemical bonding, either directly or via another group. Among these, carbon black having a carboxyl group or a phosphate group introduced onto the surface is preferred, and carbon black having a carboxyl group introduced onto the surface is more preferred from the viewpoint of providing suitable viscosity stability.

[0017] The self-dispersing carbon black preferably has an average particle size of 300 nm or less, more preferably 200 nm or less, and even more preferably 150 nm or less. The "average particle size" is the volume-based average value in the particle size distribution measured by dynamic light scattering.

[0018] Examples of commercially available self-dispersible carbon black include the CAB-O-JET series manufactured by Cabot Corporation, such as "CAB-O-JET200," "CAB-O-JET300," "CAB-O-JET400," "CAB-O-JET250C," "CAB-O-JET260M," "CAB-O-JET270," and "CAB-O-JET450C," and the like, manufactured by Orient Chemical Industries Co., Ltd., such as "BONJET BLACK CW-1," "BONJET BLACK CW-2," "BONJET BLACK CW-3," and "BONJET BLACK CW-4."

[0019] The carbon black preferably further contains resin-dispersed carbon black. By containing the resin-dispersed carbon black, the fastness of the printed matter can be suitably imparted. The resin-dispersed carbon black is a carbon black that can be imparted with dispersibility by the addition of a pigment dispersant (resin).

[0020] Examples of carbon black that can be used in the resin-dispersed carbon black include furnace black, lamp black, acetylene black, and channel black.

[0021] As the pigment dispersant, it is preferable to use a polymer dispersant (resin dispersant). Examples of such pigment dispersants include acrylic acid-acrylonitrile copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid copolymer-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer, and vinylnaphthalene-maleic acid copolymer, as well as inorganic salts or organic salts (neutralized products) thereof. These pigment dispersants can be used alone or in combination of two or more. Among them, from the viewpoint of storage stability of the ink composition, styrene-acrylic acid copolymers and neutralized products thereof are preferred, and acrylic acid / lauryl acrylate / styrene copolymers and neutralized products thereof are more preferred.

[0022] From the viewpoint of storage stability of the ink composition, the pigment dispersant preferably has a weight average molecular weight of 15,000 or more and 50,000 or less, and more preferably 20,000 or more and 40,000 or less. In this specification, the "weight average molecular weight" is the weight average molecular weight measured using GPC (gel permeation chromatography) and converted into standard polystyrene.

[0023] From the viewpoint of storage stability of the ink composition, the pigment dispersant preferably has an acid value of 80 mgKOH / g or more and 180 mgKOH / g or less, and more preferably 100 mgKOH / g or more and 150 mgKOH / g or less. In this specification, the "acid value" refers to a theoretical acid value obtained by arithmetically calculating the number of milligrams of potassium hydroxide theoretically required to neutralize 1 g of the unneutralized resin (pigment dispersant).

[0024] The pigment dispersant is preferably contained in an amount of 1 part by mass or more and 200 parts by mass or less per 100 parts by mass of the carbon black, more preferably 5 parts by mass or more and more preferably 60 parts by mass or less per 100 parts by mass of the carbon black.

[0025] The method for preparing the resin-dispersed carbon black dispersion is not particularly limited. The dispersion may be prepared by adding carbon black to a varnish in which the pigment dispersant has been dissolved, and using various dispersing machines, such as a ball mill, a bead mill, an attritor, a roll mill, a sand mill, or an agitator mill.

[0026] The mass ratio of the self-dispersible carbon black to the resin-dispersible carbon black is preferably 1:5 to 5:1. By setting the mass ratio of the self-dispersible carbon black to the resin-dispersible carbon black within this range, it is possible to impart suitable fastness to printed matter. The mass ratio of the self-dispersible carbon black to the resin-dispersible carbon black is more preferably 1:4 to 1:1.

[0027] The carbon black may contain carbon black dispersed with a dispersant other than a surfactant or a resin dispersant, as long as the effect of the present invention is not adversely affected.

[0028] The content of the carbon black is, for example, preferably 3% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less, relative to the total mass of the ink composition.

[0029] (Water-dispersible resin) The ink composition of the present invention contains a water-dispersible resin.

[0030] The water-dispersible resin contains at least one water-dispersible urethane resin selected from the group consisting of polyether-based polyurethanes, polyester-based polyurethanes, and polycarbonate-based polyurethanes.

[0031] The water-dispersible urethane resin has a breaking elongation of 700% or more and 1700% or less. The breaking elongation of the water-dispersible urethane resin within the above range can improve the viscosity stability of the ink composition and impart a texture to the printed matter. The breaking elongation of the water-dispersible urethane resin is preferably 750% or more, and more preferably 800% or more. Furthermore, the breaking elongation is preferably 1500% or less, and more preferably 1200% or less.

[0032] The water-dispersible urethane resin has a tensile strength of 30 MPa or less. When the tensile strength of the water-dispersible urethane resin is in the above range, the viscosity stability of the ink composition can be improved and the texture of the printed matter can be imparted. The tensile strength of the water-dispersible urethane resin is preferably 10 MPa or more, more preferably 15 MPa or more, and even more preferably 20 MPa or more.

[0033] In this specification, "tensile strength" and "elongation at break" are determined by the following method. A water-dispersible urethane resin is applied to a polytetrafluoroethylene sheet, dried at room temperature for 12 hours, and then dried at 60°C for 6 hours. The sheet is then peeled off to prepare a resin film made of the water-dispersible urethane resin with a film thickness of 500 μm. Using a tensile tester [manufactured by Yasuda Seiki Seisakusho Co., Ltd.], the obtained resin film is pulled at a measurement temperature of 25°C and a pulling rate of 200 mm / min, and the strength and elongation at break are determined.

[0034] Examples of commercially available water-dispersible urethane resins include "Impranil DLU" and "Impranil DL1380" manufactured by Sumika Covestro Urethane Co., Ltd., "ADEKA BONTITAR HUX-282" manufactured by Adeka Corporation, "DAOTON TW6490" manufactured by Daicel Allnex Corporation, and "Takelac W-6061T" manufactured by Mitsui Chemicals, Inc.

[0035] The content of the water-dispersible urethane resin is 100 parts by mass or more and 300 parts by mass or less in terms of solid content per 100 parts by mass of the carbon black. By including the water-dispersible urethane resin in this range, it is possible to impart robustness and texture to printed matter and viscosity stability to the ink composition. The content of the water-dispersible urethane resin is preferably 125 parts by mass or more, more preferably 150 parts by mass or more, in terms of solid content per 100 parts by mass of the carbon black. The content of the water-dispersible urethane resin is preferably 275 parts by mass or less, more preferably 250 parts by mass or less, in terms of solid content per 100 parts by mass of the carbon black.

[0036] (Water) The ink composition of the present invention contains water.

[0037] The water content in the ink composition of the present invention is preferably, for example, 30% by mass or more and 80% by mass or less.

[0038] (Organic Solvent) The ink composition of the present invention may contain an organic solvent as needed.

[0039] The organic solvent is preferably a water-soluble organic solvent, and examples of the water-soluble organic solvent include glycol ethers such as glycerin, dipropylene glycol dimethyl ether, and diethylene glycol ethyl methyl ether, glycol ether esters, alcohols, ketones, organic carbonates, and mixtures thereof.

[0040] The content of the organic solvent in the ink composition of the present invention is preferably, for example, 15% by mass or more and 50% by mass or less.

[0041] (Surfactant) The ink composition of the present invention may contain a surfactant as needed.

[0042] The surfactant may be any of cationic, anionic, amphoteric, and nonionic surfactants, which may be appropriately selected from known surfactants. Among these, nonionic surfactants are preferred from the viewpoint of storage stability of the ink composition.

[0043] The content of the surfactant in the ink composition of the present invention is preferably, for example, 0.01% by mass or more and 1% by mass or less.

[0044] (Others) Various additives can be added to the ink composition of the present invention as needed. Specific examples include light stabilizers, surface treatment agents, antioxidants, antiaging agents, crosslinking accelerators, plasticizers, preservatives, pH adjusters, antifoaming agents, and moisturizing agents. Known additives can be appropriately selected and used as these additives.

[0045] (Method for Producing Ink Composition) The method for producing the ink composition of the present invention is not particularly limited, and the above materials may be mixed by stirring using a known method.

[0046] (Printed Material) The substrate to be printed with the ink composition of the present invention may be a conventionally used fabric, but for example, fabrics made of cotton, silk, linen, rayon, acetate, nylon or polyester fibers, and blended fabrics made of two or more of these fibers can also be used.

[0047] The method for printing the ink composition of the present invention is not particularly limited, and it may be printed onto the substrate using a known inkjet printing device.

[0048] (Physical Properties of Ink Composition) The ink composition of the present invention has good viscosity stability. In this specification, viscosity stability is evaluated by the following method.

[0049] The ink composition is placed in a glass bottle, and the viscosity at 25°C is measured using a viscometer (RE100L model, manufactured by Toki Sangyo Co., Ltd.). The bottle is then sealed and stored at 60°C for 4 weeks, and the viscosity (25°C) after storage is measured using the same viscometer. Viscosity stability is evaluated based on the viscosity change rate [[(viscosity after 4 weeks at 60°C - viscosity before storage) / (viscosity before storage)] x 100]. If the viscosity change rate is 5% or less, the viscosity stability is evaluated as good, and if it is 3% or less, the viscosity stability is evaluated as extremely good.

[0050] The ink composition of the present invention has excellent density in printed matter. In this specification, the density of printed matter is evaluated by the following method.

[0051] A solid image of the ink composition is printed on 100% cotton white fabric using an evaluation printer equipped with a SPECTRA head, and then dried using a conveyor oven to produce a printed product for evaluation. The image density (OD value) of the printed product for evaluation is measured using a spectrophotometer (X-Rite eXact, manufactured by X-Rite). An OD value of 1.45 or higher is considered to have excellent density, and an OD value of 1.5 or higher is considered to have extremely excellent density.

[0052] The ink composition of the present invention provides excellent fastness of printed matter. In this specification, the fastness of printed matter is evaluated by preparing a printed matter for evaluation in the same manner as in the evaluation method for the density of printed matter described above, and evaluating the fastness to washing, fastness to dry rubbing, and fastness to wet rubbing. If all the tests pass or exceed the standard, the printed matter is judged to have excellent fastness.

[0053] The washing fastness is evaluated by the following method. The above printed matter for evaluation is washed five times in a household washing machine under normal washing conditions (washing, spin-drying, and drying in normal mode), and the image density (OD value) of the printed matter before and after washing is measured using a spectrophotometer (X-Rite eXact, manufactured by X-Rite Corporation), and evaluated as the rate of change from the initial value (before washing). If the OD value after washing is 80% or higher, it is evaluated as passing, and if it is 90% or higher, it is evaluated as being particularly excellent.

[0054] Dry rubbing fastness is evaluated by the following method. The printed surface of the evaluation print is rubbed 100 times with a bleached cloth under a load of 200 g using a Gakushin-type fastness tester (manufactured by Daiei Scientific Instruments Co., Ltd.). The degree of staining of the bleached cloth at this time is evaluated using a staining gray scale in accordance with JIS L 0805:2005. Grades 3-4 or higher are evaluated as passing, and grades 4-5 or higher are evaluated as being particularly excellent.

[0055] Wet rubbing fastness is evaluated by the following method. The surface of the printed material for evaluation is rubbed 100 times with a water-soaked bleached cloth under a load of 200 g using a Gakushin-type fastness tester (manufactured by Daiei Scientific Instruments Co., Ltd.). The degree of staining of the bleached cloth at this time is evaluated using a staining gray scale in accordance with JIS L 0805:2005. Grades 3-4 or higher are evaluated as passing, and grades 4-5 or higher are evaluated as being particularly excellent.

[0056] The ink composition of the present invention has excellent texture. In this specification, the texture is evaluated by preparing a printed material for evaluation in the same manner as the method for evaluating the density of the printed material described above and evaluating it by touch. A printed material that bends easily but feels slightly stiffer than the fabric itself is evaluated as having excellent texture, and a printed material that bends easily and feels close to the softness of 100% cotton fabric itself is evaluated as having particularly excellent texture.

[0057] The present specification discloses the following:

[0058] The present disclosure (1) is an inkjet ink composition for textile printing containing at least carbon black, a water-dispersible resin, and water, wherein the carbon black contains self-dispersible carbon black, the water-dispersible resin contains at least one water-dispersible urethane resin selected from the group consisting of polyether-based polyurethanes, polyester-based polyurethanes, and polycarbonate-based polyurethanes, the water-dispersible urethane resin having a breaking elongation of 700% or more and a tensile strength of 30 MPa or less, and the content of the water-dispersible urethane resin is 100 parts by mass or more and 300 parts by mass or less in terms of solid content per 100 parts by mass of the carbon black. The present disclosure (2) is the inkjet ink composition for textile printing according to the present disclosure (1), wherein the carbon black further contains resin-dispersible carbon black. The present disclosure (3) is the inkjet ink composition for textile printing according to the present disclosure (1) or (2), wherein the mass ratio of the self-dispersible carbon black to the resin-dispersible carbon black is 1:5 to 5:1.

[0059] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0060] The materials used in the examples and comparative examples are as follows.

[0061] (Self-dispersible carbon black dispersions) Self-dispersible carbon black dispersion 1 (product name "CAB-O-JET300", manufactured by Cabot Corporation, pigment concentration 15% by mass, containing carboxyl groups) Self-dispersible carbon black dispersion 2 (product name "CAB-O-JET400", manufactured by Cabot Corporation, pigment concentration 15% by mass, containing phosphate groups)

[0062] (Resin-Dispersed Carbon Black Dispersion) 25 parts by weight of a pigment dispersant (acrylic acid / lauryl acrylate / styrene copolymer, weight-average molecular weight 20,000, acid value 140 mgKOH / g) was dissolved in a mixed solution of 3.5 parts by weight of potassium hydroxide and 71.5 parts by weight of water to obtain an aqueous resin varnish containing the pigment dispersant with a solids content of 25% by weight. 73 parts by weight of water was added to 12 parts by weight of the aqueous resin varnish, and 15 parts by weight of carbon black (product name "MA100" manufactured by Mitsubishi Chemical Corporation) was added and mixed with stirring. The mixture was then milled in a wet circulation mill to produce a resin-dispersed carbon black dispersion. The weight-average molecular weight and acid value of the pigment dispersant were measured according to the methods described herein.

[0063] (Water-dispersible resins) Resin 1 (polycarbonate-based polyurethane, product name "Impranil DLU", manufactured by Sumika Covestro Urethanes Co., Ltd., solid content 60% by mass, elongation at break 800%, tensile strength 30 MPa) Resin 2 (polyester-based polyurethane, product name "Impranil DL1380", manufactured by Sumika Covestro Urethanes Co., Ltd., solid content 60% by mass, elongation at break 1200%, tensile strength 25 MPa) Resin 3 (polyether-based polyurethane, product name "Adeka Bontitor HUX-282", manufactured by Adeka Corporation, solid content 55% by mass, elongation at break 1100%, tensile strength 25 MPa) Resin 4 (polyester-based polyurethane, product name "Impranil DLC-T", manufactured by Sumika Covestro Urethanes Co., Ltd., solid content 35% by mass, elongation at break 500%, tensile strength 6 MPa) Resin 5 (polyester polyurethane, product name "ADEKA BONTITAR HUX-895", manufactured by ADEKA Corporation, solid content 48% by mass, elongation at break 900%, tensile strength 40 MPa) Resin 6 (polyether polyurethane, product name "NeoRez R-967", manufactured by Sumika Covestro Urethane Co., Ltd., solid content 40% by mass, elongation at break 600%, tensile strength 34.3 MPa) Resin 7 (polyester polyurethane, product name "Yodosol RA85", manufactured by Henkel Japan KK, solid content 40% by mass, elongation at break 400%, tensile strength 30 MPa) The elongation at break and tensile strength of the water-dispersible resins were measured by the methods described herein.

[0064] (Surfactants) Surfactant 1 (product name "E1010", manufactured by Nissin Chemical Industry Co., Ltd.) Surfactant 2 (product name "Surfynol 440", manufactured by Nissin Chemical Industry Co., Ltd.)

[0065] (Water) Water (purified water)

[0066] (organic solvent) glycerin

[0067] (Examples 1 to 8, Comparative Examples 1 to 7) <Preparation of ink compositions> Each ink composition was prepared by blending the materials based on Tables 1 and 2 and stirring and mixing them by a known method. Note that the "amount of resin relative to carbon black" in Tables 1 and 2 refers to the content of water-dispersible urethane resin (parts by mass of solids) relative to 100 parts by mass of carbon black.

[0068] <Viscosity Stability> The prepared ink composition was placed in a glass bottle, and the viscosity at 25°C was measured using a viscometer (RE100L model, manufactured by Toki Sangyo Co., Ltd.). The bottle was then sealed and stored at 60°C for 4 weeks, and the viscosity (25°C) after storage was measured using the same viscometer. From the measured viscosity, the viscosity change rate [[(viscosity after 4 weeks at 60°C - viscosity before storage) / (viscosity before storage)] x 100] was calculated and evaluated according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation Criteria) ⊚: The viscosity change rate was less than 3%. ◯: The viscosity change rate was 3% or more and less than 5%. ×: The viscosity change rate was 5% or more and less than 10%. XX: The viscosity change rate was 10% or more.

[0069] <Preparation of Printed Material for Evaluation> A solid image of the ink composition prepared using an evaluation printer equipped with a head manufactured by SPECTRA was printed on a 100% cotton white fabric, and then dried using a conveyor oven to prepare a printed material for evaluation.

[0070] <Density> The image density (OD value) of the evaluation prints produced was measured using a spectrophotometer (X-Rite eXact, manufactured by X-Rite Corporation) and evaluated according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) ⊚: OD value was 1.5 or more. ○: OD value was 1.45 or more and less than 1.5. ×: OD value was 1.4 or more and less than 1.45. XX: OD value was less than 1.4.

[0071] <Fastness to washing> The prepared printed matter for evaluation was washed five times in a household washing machine under normal washing conditions (washing, spin-drying, and drying in normal mode), and the image density (OD value) of the printed matter before and after washing was measured using a spectrophotometer (X-Rite eXact, manufactured by X-Rite Corporation). Evaluation was based on the rate of change from the initial value (before washing) and according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) ⊚: The OD value after washing was 90% or more of the initial value. ○: The OD value after washing was 80% or more and less than 90% of the initial value. ×: The OD value after washing was 70% or more and less than 80% of the initial value. XX: The OD value after washing was less than 70% of the initial value.

[0072] <Dry rubbing fastness> The printed surface of the prepared evaluation print was rubbed 100 times with a bleached cloth under a load of 200 g using a Gakushin-type fastness tester (manufactured by Daiei Scientific Instruments Manufacturing Co., Ltd.). The degree of staining of the bleached cloth at this time was evaluated using the staining gray scale in accordance with JIS L 0805:2005 and the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) ◎: Grade 4-5 to 5. ○: Grade 3-4 to 4. ×: Grade 2-3 to 3. XX: Grade 2 or lower.

[0073] <Wet rubbing fastness> The surface of the printed material for evaluation was rubbed 100 times with a water-soaked bleached cloth under a load of 200 g using a Gakushin-type fastness tester (manufactured by Daiei Scientific Instruments Co., Ltd.). The degree of staining of the bleached cloth was evaluated using the staining gray scale in accordance with JIS L 0805:2005 and the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) ◎: Grade 4-5 to 5. ○: Grade 3-4 to 4. ×: Grade 2-3 to 3. XX: Grade 2 or lower.

[0074] <Texture> The prints prepared for evaluation were touched and evaluated according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) ⊚: The print bends easily and is close to the softness of 100% cotton fabric itself. ◯: The print bends easily, but feels slightly stiffer than fabric itself. ×: The print feels stiff. XX: The print is so stiff that it cannot bend freely.

[0075]

[0076]

[0077] From Tables 1 and 2, it was confirmed that the ink compositions of the examples had good viscosity stability and provided excellent density, fastness, and texture in printed matter.

[0078] It is possible to provide an inkjet ink composition for textile printing that has good viscosity stability and produces printed products with excellent density, fastness, and texture.

Claims

1. An inkjet ink composition for textile printing, comprising at least carbon black, a water-dispersible resin, and water, wherein the carbon black comprises self-dispersible carbon black, the water-dispersible resin comprises at least one water-dispersible urethane resin selected from the group consisting of polyether-based polyurethanes, polyester-based polyurethanes, and polycarbonate-based polyurethanes, the water-dispersible urethane resin has a breaking elongation of 700% or more and 1700% or less and a tensile strength of 30 MPa or less, and the content of the water-dispersible urethane resin is 100 parts by mass or more and 300 parts by mass or less in terms of solid content per 100 parts by mass of the carbon black.

2. The ink-jet ink composition for textile printing according to claim 1, wherein the carbon black further comprises resin-dispersed carbon black.

3. The inkjet ink composition for textile printing according to claim 1 or 2, wherein the mass ratio of the self-dispersed carbon black to the resin-dispersed carbon black is 1:5 to 5:1.

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