WO2025204603A1 - Inkjet ink composition for textile printing - Google Patents

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

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

A method of printing onto fabrics by inkjet printing with ink containing pigments is known.

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 has a breaking elongation of 1200 to 1800% and a tensile strength of 10 to 48 MPa, and the amount of the water-dispersible resin is 1.0 to 3.0 parts by mass per part by mass of the pigment, and the amount of 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 the inkjet ink for textile printing have excellent fastness and texture.

Japanese Patent Application Laid-Open No. 2019-031611

Textile printing using inkjet printing with an ink composition containing a pigment tends to produce prints with lower density than ink compositions containing a dye, but the advantage of pigment-containing inks is that they are superior in terms of durability.

On the other hand, while a technique for using a pretreatment agent to increase the concentration of a pigment-containing ink composition is known, it is difficult to achieve a balance with fastness, leading to increased costs and reduced productivity. Therefore, there has been a demand for an ink composition containing a pigment for inkjet textile printing that produces good density in printed products without the use of a pretreatment agent.

In addition, ink compositions for textile printing are required to have the ability to maintain a constant viscosity (viscosity stability) in order to ensure ejection properties using inkjet printing methods.

The present invention therefore aims to provide an inkjet ink composition for textile printing that not only provides excellent fastness and texture to the printed matter (textile print), but also has excellent density in the printed matter and viscosity stability of the ink composition.

The present invention provides an inkjet ink composition for textile printing that contains at least carbon black, a water-dispersible resin, and water, wherein the carbon black is self-dispersible carbon black, the water-dispersible resin is 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.

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

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

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, and 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 1700% 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.

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, and by optimizing the amount of water-dispersible resin having specific physical properties added, it is possible to achieve both fastness and texture of printed matter and storage stability of the ink composition.
However, the present invention should not be construed as being limited to the above mechanism.

(carbon black)
The ink composition of the present invention contains carbon black.

The carbon black contains self-dispersible carbon black.
By containing the above-mentioned self-dispersible carbon black and the 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-dispersing carbon black is carbon black that can be dispersed in water without using a pigment dispersant by chemically treating the surface of the carbon black to add hydrophilic functional groups such as carboxyl groups and phosphate groups.

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 on the surface is preferred, and from the viewpoint of providing suitable viscosity stability, carbon black having a carboxyl group introduced is more preferred.

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 a volume-based average value in a particle size distribution measured by dynamic light scattering.

Commercially available examples of the 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 products 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."

The carbon black preferably further contains resin-dispersed carbon black.
By including the resin-dispersed carbon black, it is possible to provide suitable fastness to printed matter.
The resin-dispersed carbon black is carbon black that can be provided with dispersibility by a pigment dispersant (resin).

The carbon black that can be used in the resin-dispersed carbon black includes, for example, furnace black, lamp black, acetylene black, channel black, etc.

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) of these.
These pigment dispersants may be used alone or in combination of two or more.
Among these, 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.

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 term "weight average molecular weight" refers to a weight average molecular weight measured using GPC (gel permeation chromatography) and converted into standard polystyrene.

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 term "acid value" refers to a theoretical acid value calculated arithmetically from the number of milligrams of potassium hydroxide theoretically required to neutralize 1 g of the unneutralized resin (pigment dispersant).

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.
The content of the pigment dispersant is more preferably 5 parts by mass or more and more preferably 60 parts by mass or less relative to 100 parts by mass of the carbon black.

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

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-dispersed carbon black to the resin-dispersed carbon black within the above 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.

The above carbon black may also include carbon black dispersed with a dispersant other than a surfactant or a resin dispersant, as long as the effects of the present invention are not affected.

The content of the carbon black is preferably, for example, 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.

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

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.
When the breaking elongation of the water-dispersible urethane resin is within the above range, the viscosity stability of the ink composition can be improved, and the texture of the printed matter can be imparted.
The water-dispersible urethane resin preferably has a breaking elongation of 750% or more, more preferably 800% or more, and preferably has a breaking elongation of 1500% or less, more preferably 1200% or less.

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 within 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.

In this specification, the "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 further dried at 60°C for 6 hours. The sheet is then peeled off to produce a resin film made of the water-dispersible urethane resin with a thickness of 500 μm.
The resin film obtained is pulled using a tensile tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) at a measurement temperature of 25° C. and a pulling rate of 200 mm/min, and the strength and elongation at break are determined.

Commercially available examples of the water-dispersible urethane resin include "Impranil DLU" and "Impranil DL1380" manufactured by Sumika Covestro Urethanes Co., Ltd., "Adeka Bontitor HUX-282" manufactured by Adeka Corporation, "DAOTON TW6490" manufactured by Daicel Allnex Corporation, and "Takelac W-6061T" manufactured by Mitsui Chemicals, Inc.

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 relative to 100 parts by mass of the carbon black.
By including the water-dispersible urethane resin in the above range, it is possible to impart fastness and texture to the printed matter and viscosity stability to the ink composition.
The water-dispersible urethane resin is preferably present in an amount of 125 parts by mass or more, and more preferably 150 parts by mass or more, in terms of solid content, per 100 parts by mass of the carbon black.
The amount of the water-dispersible urethane resin is preferably 275 parts by mass or less, and more preferably 250 parts by mass or less, in terms of solid content, per 100 parts by mass of the carbon black.

(water)
The ink composition of the present invention contains water.

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.

(organic solvent)
The ink composition of the present invention may contain an organic solvent as needed.

The organic solvent is preferably a water-soluble organic solvent.
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.

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.

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

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

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.

(others)
Various additives may 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.
These additives can be appropriately selected from known additives.

(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.

(Printed material)
The substrate to be printed with the ink composition of the present invention may be any conventionally used fabric, and may be, for example, a fabric made of cotton, silk, linen, rayon, acetate, nylon or polyester fiber, or a blended fabric made of two or more of these fibers.

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

(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.

The ink composition is placed in a glass bottle, and the viscosity at 25°C is measured using a viscometer (Model RE100L 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.
The viscosity stability is evaluated based on the viscosity change rate [[(viscosity after 4 weeks at 60° C.−viscosity before storage)/(viscosity before storage)]×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 very good.

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

A solid image of the ink composition is printed on a 100% cotton white fabric using an evaluation printer equipped with a SPECTRA head, and then dried using a conveyor oven to prepare a printed matter for evaluation.
The image density (OD value) of the print for evaluation is measured using a spectrophotometer (X-Rite eXact, manufactured by X-Rite Corporation).
If the OD value is 1.45 or more, the print density is evaluated as excellent, and if it is 1.5 or more, the print density is evaluated as extremely excellent.

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

The washing fastness is evaluated by the following method.
The above printed matter for evaluation was washed five times in a normal manner in a household washing machine (washing conditions: wash, spin, dry 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), and the image density was evaluated as the rate of change from the initial value (before washing).
If the OD value after washing is 80% or more, it is evaluated as pass, and if it is 90% or more, it is evaluated as particularly excellent.

The 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 color fastness tester (manufactured by Daiei Scientific Instruments Co., Ltd.) The degree of staining of the bleached cloth at this time is evaluated using the staining gray scale in accordance with JIS L 0805:2005.
If the above evaluation is 3-4 grade or above, it is evaluated as passing, and if it is 4-5 grade or above, it is evaluated as particularly excellent.

The 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 color fastness tester (manufactured by Daiei Scientific Instruments Co., Ltd.) The degree of staining of the bleached cloth is evaluated using the staining gray scale in accordance with JIS L 0805:2005.
If the above evaluation is 3-4 grade or above, it is evaluated as passing, and if it is 4-5 grade or above, it is evaluated as particularly excellent.

The ink composition of the present invention has excellent texture.
In this specification, the texture is evaluated by preparing a print for evaluation in the same manner as in the evaluation method for the density of the print, and evaluating the texture by touch.
A printed matter that bends easily but feels slightly stiffer than the fabric itself is rated as having an excellent texture, and a printed matter that bends easily and feels close to the softness of 100% cotton fabric itself is rated as having an especially excellent texture.

This specification discloses the following:

The present disclosure (1) 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.
The present disclosure (2) is the inkjet ink composition for textile printing according to the present disclosure (1), in which the carbon black further contains resin-dispersed 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.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

The materials used in the examples and comparative examples are as follows:

(Self-dispersing carbon black dispersion)
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)

(Resin-dispersed carbon black dispersion)
25 parts by mass 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 mass of potassium hydroxide and 71.5 parts by mass of water to obtain an aqueous resin varnish containing the pigment dispersant with a solids content of 25% by mass.
73 parts by mass of water was added to 12 parts by mass of the aqueous resin varnish, and mixed. 15 parts by mass of carbon black (product name "MA100", manufactured by Mitsubishi Chemical Corporation) was further added and mixed with stirring, and then the mixture was milled in a wet circulation mill to prepare a resin-dispersed carbon black dispersion.
The weight average molecular weight and acid value of the pigment dispersant were measured by the methods described herein.

(Water dispersible resin)
Resin 1 (polycarbonate-based polyurethane, product name "Impranil DLU", manufactured by Sumika Covestro Urethane Co., Ltd., solid content 60% by mass, elongation at break 800%, tensile strength 30 MPa)
Resin 2 (polyester polyurethane, product name "Impranil DL1380", manufactured by Sumika Covestro Urethane Co., Ltd., solid content 60% by mass, elongation at break 1200%, tensile strength 25 MPa)
Resin 3 (polyether polyurethane, product name "ADEKA BONTITAR HUX-282", manufactured by ADEKA Corporation, solid content 55% by mass, elongation at break 1100%, tensile strength 25 MPa)
Resin 4 (polyester polyurethane, product name "Impranil DLC-T", manufactured by Sumika Covestro Urethane 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, solid content 40% by mass, elongation at break 400%, tensile strength 30 MPa)
The elongation at break and tensile strength of the water-dispersible resin were measured by the methods described in this specification.

(Surfactant)
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.)

(water)
Water (purified water)

(organic solvent)
glycerin

(Examples 1 to 8, Comparative Examples 1 to 7)
<Preparation of Ink Composition>
Each material was blended based on Tables 1 and 2, and stirred and mixed by a known method to prepare each ink composition.
In Tables 1 and 2, the "amount of resin relative to carbon black" refers to the content of water-dispersible urethane resin (parts by mass of solid content) relative to 100 parts by mass of carbon black.

<Viscosity stability>
The prepared ink composition was placed in a glass bottle, and the viscosity at 25° C. was measured using a viscometer (Model RE100L manufactured by Toki Sangyo Co., Ltd.).
Thereafter, the container was sealed and stored at 60°C for 4 weeks, and the viscosity (25°C) after storage was measured using the above viscometer.
From the viscosity measured above, 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%.
Good: 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.

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

<Concentration>
The image density (OD value) of the evaluation prints 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.
Good: The OD value was 1.45 or more and less than 1.5.
×: The OD value was 1.4 or more and less than 1.45.
XX: The OD value was less than 1.4.

<Washing fastness>
The produced prints for evaluation were 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 prints before and after washing was measured using a spectrophotometer (X-Rite eXact, manufactured by X-Rite Corporation).
The results are shown in Tables 1 and 2.
(Evaluation criteria)
⊚: The OD value after washing was 90% or more of the initial value.
Good: The OD value after washing was 80% or more and less than 90% of the initial value.
x: 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.

<Dry rubbing fastness>
The printed surface of the evaluation print was rubbed 100 times with a bleached cloth under a load of 200 g using a Gakushin-type color 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, according to the following criteria. The results are shown in Tables 1 and 2.
(Evaluation criteria)
◎: Grade 4-5 to 5.
○: Grade 3-4 to Grade 4.
×: Grade 2-3 to Grade 3.
××: Grade 2 or below.

<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 color 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, according to the following criteria. The results are shown in Tables 1 and 2.
(Evaluation criteria)
◎: Grade 4-5 to 5.
○: Grade 3-4 to Grade 4.
×: Grade 2-3 to Grade 3.
××: Grade 2 or below.

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

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.
It was confirmed that...

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

Claims (3)

An inkjet ink composition for textile printing, comprising at least carbon black, a water-dispersible resin, and water,
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,
The inkjet ink composition for textile printing, wherein 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 relative to 100 parts by mass of the carbon black. The inkjet ink composition for textile printing according to claim 1, wherein the carbon black further contains resin-dispersed carbon black. 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.