JP7722609B2 - Inkjet printing ink and inkjet recording method - Google Patents

Description

The present invention relates to inkjet textile printing ink and an inkjet recording method.

Screen printing has traditionally been the mainstream textile printing method for fabrics, but in response to the need for reducing environmental impact and small-lot, high-mix printing, textile printing by inkjet printing using aqueous pigment inks is gaining popularity. If the fixability and followability of the aqueous pigment ink on fabric are poor, the ink will not follow the fabric when the resulting printed fabric is stretched, causing cracks in the printed image. Therefore, development of aqueous pigment inks with good fixability and followability is underway.
For dark-colored fabrics, a method has been used in which a white ink containing a white pigment is formed as a base layer and then color inks are printed on top of it to make the image more recognizable. However, if the color development of the white ink, i.e., its whiteness, is low, the color development of the color inks is also reduced. Furthermore, if the coating properties of the white ink, such as strength and elongation, are poor, the printed textile obtained by printing color inks on the white ink will also crack, resulting in poor quality.

In recent years, inkjet printing devices equipped with ink-circulating inkjet heads have become known as they prevent clogging of ejection nozzles due to settling of pigments, resin particles, etc. within the inkjet heads.
The use of ink-circulating inkjet heads is also increasing for color inks, but in the case of white ink in particular, titanium oxide is often used as the main pigment, and the ink needs to be circulated within the ink passage to prevent sedimentation. Therefore, suitability for the ink-circulating inkjet head is particularly important for white ink.

One type of textile printing method using inkjet printing is direct-to-garment (DTG) printing, which involves printing directly onto fabric. However, this printing method has the drawback of being difficult to achieve high color development, and requires the application of a pretreatment agent or an increased amount of ink to form a highly colored image, which can impair the texture of the fabric.
In contrast to this, DTF (direct-to-film) printing, which is a method in which an image is formed on a transfer film and then thermally transferred onto fabric, has attracted attention as a simpler method that can achieve high color development.

For example, Patent Document 1 discloses a technique in which a transfer film is prepared using a specific ink, and then the ink is thermally transferred onto a pretreated fabric, and then post-treated to improve fixability.
However, the technology described in Patent Document 1 does not take any measures regarding the strength of the ink coating after printing or its recyclability, and there are cases where defects such as cracks occur when the printed fabric is stretched, or the path becomes blocked due to circulation.

Japanese Patent Application Laid-Open No. 2022-21342

In light of the above, the problem that this invention aims to solve is to provide an inkjet printing ink that does not cause cracks or breaks in the image when the printed material is stretched, and that does not clog the path even when the ink is circulated through a circulation inkjet head.

The present invention solves the above-mentioned problems by providing an inkjet textile printing ink containing a pigment and a binder resin, wherein the binder resin contains a polyether-based urethane resin, and the ink is applied to a polyethylene terephthalate plate and dried to form a 15 μm-thick coating film, the difference in indentation depth between at 100°C and at 30°C being less than 250 nm.
An example of the configuration of the present invention that solves the above problem is as follows.

Item 1. An inkjet printing ink containing a pigment and a binder resin,
the binder resin contains a polyether-based urethane resin,
The inkjet textile printing ink, wherein the ink is applied to a polyethylene terephthalate plate and dried to form a 15 μm thick coating film, and the difference in indentation depth between the ink at 100° C. and the ink at 30° C. is less than 250 nm.

Item 2. The inkjet printing ink according to Item 1, wherein the pigment is a white pigment.

Item 3. The inkjet printing ink described in Item 2, wherein the white pigment is alumina-treated titanium oxide.

Item 4. A step of printing the inkjet textile printing ink according to any one of Items 1 to 3 onto a film substrate to obtain a transfer film;
A method for producing a printed matter, comprising the steps of overlapping the transfer surface of a fabric and the printing surface of the transfer film, and performing thermal transfer.

Item 5. A method for producing a printed matter described in Item 4, further comprising a step of applying an adhesive resin to the printed surface of the transfer film.

Item 6. A textile print in which an inkjet printing ink containing a pigment and a binder resin is printed on a fabric,
the binder resin is a polyether-based urethane resin,
The ink is an ink in which the difference in indentation depth between the ink at 100°C and the ink at 30°C in a coating film having a thickness of 15 μm that is applied to a polyethylene terephthalate plate and dried is less than 250 nm.

The present invention makes it possible to provide an inkjet printing ink that produces printed matter with high color density, does not cause cracks or breaks in the image when stretched, and does not clog the path when the ink is circulated.

The present invention also makes it possible to provide a white ink for inkjet textile printing that produces printed matter with high whiteness, does not cause cracks or breaks in the image when stretched, and does not clog the path when the ink is circulated.

FIG. 1 is a schematic diagram of a microreactor used in the present invention.

The inkjet textile printing ink of the present invention is an inkjet textile printing ink containing a pigment and a binder resin, wherein the binder resin contains a polyether-based urethane resin, and when the ink is applied to a polyethylene terephthalate plate and dried, the difference in indentation depth between the ink at 100°C and the ink at 30°C to a thickness of 15 μm is less than 250 nm.

(binder resin)
The binder resin used in the inkjet textile printing ink of the present invention is a polyether-based urethane resin.

(Polyether urethane resin)
The polyether-based urethane resin is a polyurethane resin that uses a polyether diol as a polymer polyol component (soft segment). The polyether diol content in the diol used as a raw material for the polyether-based urethane resin is preferably in the range of 10% to 90% by mass. Using a polyether diol content in the range of 50% to 90% by mass is more preferable in order to prevent clogging over time of a filter installed in the ink circulation path. The polyether-based urethane resin may also contain polycarbonate diol, polyester diol, or the like as a raw material if necessary, but preferably contains only polyether diol from the viewpoint of balance of performance.

As the polyether-based urethane resin, it is preferable to use a polyurethane having hydrophilic groups in order to improve the aqueous dispersion stability in the inkjet textile printing ink of the present invention.

The hydrophilic group may be generally known as an anionic group, cationic group, or nonionic group. It is particularly preferable to use an anionic group or a cationic group as the hydrophilic group.

Examples of the anionic group that can be used include carboxyl groups, carboxylate groups, sulfonic acid groups, and sulfonate groups. In particular, it is preferable to use carboxylate groups or sulfonate groups that have been partially or completely neutralized with a basic compound or the like in order to maintain good aqueous dispersion stability.

Examples of basic compounds that can be used to neutralize the anionic carboxyl and sulfonic acid groups include organic amines such as ammonia, triethylamine, pyridine, and morpholine; alkanolamines such as monoethanolamine; and metal base compounds containing Na, K, Li, and Ca. Among these, organic amines are preferred as the basic compound to prevent problems with the wash fastness of printed images that may occur due to the basic compound remaining in the printed image (i.e., dried film) formed with the inkjet textile printing ink of the present invention. It is more preferable to use organic amines with a boiling point of 100°C or less, such as ammonia and triethylamine.

The cationic group may be, for example, a tertiary amino group. Examples of acidic compounds that can be used to neutralize some or all of the tertiary amino groups include formic acid and acetic acid. Examples of quaternizing agents that can be used to quaternize some or all of the tertiary amino groups include dialkyl sulfates such as dimethyl sulfate and diethyl sulfate.

The nonionic group may be a polyoxyalkylene group such as a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly(oxyethylene-oxypropylene) group, or a polyoxyethylene-polyoxypropylene group. Among these, it is preferable to use a polyoxyalkylene group having an oxyethylene unit as the nonionic group in order to further improve hydrophilicity.

It is preferable to use a polyether-based urethane resin that contains 0.5% to 30% by mass of the hydrophilic groups relative to the total amount of the polyether-based urethane resin, and it is even more preferable to use a polyether-based urethane resin that contains 1% to 20% by mass in order to obtain an ink with even better aqueous dispersion stability.

The polyether-based urethane resin can be a reaction product of a polyol, including a polyether polyol and a polyol having a hydrophilic group, and a polyisocyanate.

Examples of the polyether polyol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, sorbitol, sucrose, aconite sugar, femimellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydroxybenzoic acid, hydroxyphthalic acid, and 1,2,3-propanetrithiol. Compounds having two or more active hydrogen groups are subjected to addition polymerization of cyclic ether compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclophenexylene, or the cyclic ether compounds are subjected to ring-opening polymerization using a cationic catalyst, a protonic acid, a Lewis acid, or the like as a catalyst.
As the polyether polyol, it is preferable to use a polyether polyol such as polytetramethylene ether glycol having a number average molecular weight of 500 to 4000, it is more preferable to use a polyether polyol such as polytetramethylene ether glycol having a number average molecular weight of 1000 to 4000, and it is even more preferable to use polytetramethylene ether glycol having a number average molecular weight of 2000 to 4000.

The polyol having a hydrophilic group can be, for example, a polyol having a cationic group, such as a polyol having a tertiary amino group. Specific examples of the polyol having a tertiary amino group include N-methyl-diethanolamine and polyols obtained by reacting a compound having two epoxy groups with a secondary amine.

The polyol having a hydrophilic group can be one having an anionic group, such as 1,2-bis(hydroxymethyl)propionic acid or 1,2-bis(hydroxymethyl)butanoic acid.

The polyol having the hydrophilic group can be one having a nonionic group, such as polyethylene glycol or polypropylene glycol having structural units derived from ethylene oxide.

In addition to the polyols mentioned above, other polyols can be used as needed to produce the polyether-based urethane resin.

The polyisocyanates that react with polyols, including the polyether polyols, include, for example, aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, and aliphatic or alicyclic structure-containing diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate, which can be used alone or in combination of two or more.

In particular, when the inkjet textile printing ink of the present invention is used for printing on fabrics such as clothing, it is preferable to use an aliphatic or alicyclic structure-containing diisocyanate such as isophorone diisocyanate or dicyclohexylmethane diisocyanate as the polyisocyanate in order to further improve the texture of the printed material. Dicyclohexylmethane diisocyanate is particularly preferable because it suppresses cracking during stretching of the coating film and also has favorable effects on circulation and filtration.

When a chain extender is used in producing the polyether-based urethane resin, examples of suitable chain extenders include diamines such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, and 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, and N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, and trimethylaminopropylamine. Polyamine chain extenders such as triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic dihydrazide, adipic dihydrazide, glutaric dihydrazide, sebacic dihydrazide, isophthalic dihydrazide; β-semicarbazide propionic hydrazide, 3-semicarbazide-propyl-carbazate, and semicarbazide-3-semicarbazidemethyl-3,5,5-trimethylcyclohexane can be used, and the use of hydrazine or isophoronediamine is preferred in order to obtain an ink that is less likely to cause clogging during circulation and that can produce printed matter that has excellent washing fastness. In addition to polyamines, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, sucrose, methylene glycol, glycerin, and sorbitol; phenols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, and hydroquinone; and water can also be used.

The chain extender can be used during or after the reaction of the polyol with the polyisocyanate.

The above polyether-based urethane resin is preferably used in a range of 1% to 22% by mass relative to the total amount of the inkjet textile printing ink of the present invention, and it is more preferable to use it in a range of 8% to 15% by mass in order to prevent clogging over time of filters installed in the ink circulation path.

The viscosity of the polyether-based urethane resin as an aqueous dispersion with a non-volatile content of 20% is preferably 300 mPa·s or less, more preferably 200 mPa·s or less, and even more preferably 100 mPa·s or less. A viscosity within this range makes it easier to adjust the viscosity of the ink and increases the flexibility of ink formulation.

The polyether-based urethane resin preferably has a glass transition temperature (Tg) of 0° C. or lower, more preferably −20° C. or lower, even more preferably −40° C. or lower, and particularly preferably −50° C. or lower. When the glass transition temperature is within this range, when the resin forms a coating film on a fabric, it easily follows the stretching of the fabric.
More specifically, the temperature is preferably from -95 to -60°C, and more preferably from -90 to -70°C.
The glass transition temperature can be measured in accordance with JIS K 7121 using a differential scanning calorimeter (DSC).

The polyether-based urethane resin preferably has a flow initiation temperature of 150° C. or higher, more preferably 160° C. or higher, even more preferably 170° C. or higher, and particularly preferably 180° C. or higher. When the flow initiation temperature is within this range, the resin is less likely to flow when heated on a fabric, and therefore cracks in the coating film are less likely to occur.
As a method for adjusting the flow initiation temperature to a high level, for example, a polyisocyanate having high crystallinity such as dicyclohexylmethane diisocyanate may be used.
More specifically, the temperature is preferably 170 to 195°C, and more preferably 175 to 190°C.
The flow starting temperature can be measured for a dried resin using a flow tester "CFT-500A" manufactured by Shimadzu Corporation (using a die with a diameter of 1 mm and a length of 1 mm, a load of 98 N, and a temperature rise rate of 3°C/min).

The above polyether-based urethane resin preferably has an acid value of 5 to 40 mgKOH/g, more preferably 8 to 30 mgKOH/g, even more preferably 10 to 24 mgKOH/g, and particularly preferably 10 to 20 mgKOH/g. An acid value within this range improves the dispersion stability of the ink and helps prevent clogging over time of filters installed in the ink circulation path.

It is preferable to use a polyether-based urethane resin with a weight-average molecular weight in the range of 10,000 to 400,000, and it is even more preferable to use one in the range of 40,000 to 300,000 in order to prevent clogging over time of filters installed in the ink circulation path.

The polyether-based urethane resin is dispersed as particles in an aqueous medium, with a particle diameter of preferably 70 μm or more, and more preferably 75 μm or more, but is not limited to this. The particle diameter of the polyether-based urethane resin is the cumulative 50% diameter (D50) value measured by dynamic light scattering.

The inkjet textile printing ink of the present invention can also contain a crosslinking agent, as described below, for the purpose of further improving abrasion resistance, such as wash fastness. When using such a crosslinking agent, it is preferable to use a polyether-based urethane resin that has a functional group capable of undergoing a crosslinking reaction with the functional group of the crosslinking agent.

However, since it cannot be denied that ink containing a crosslinking agent may crosslink within the circulation path of the ink circulation type inkjet head, it is preferable to use ink that does not contain the crosslinking agent in order to prevent clogging of the filter installed within the circulation path.

(Other binder resins)
The inkjet textile printing ink of the present invention may contain a binder resin other than the polyether-based urethane resin, as long as the effect of the present invention is not impaired.
Examples of the other binder resins include polyurethane resins such as polycarbonate-based urethane resins and polyester-based urethane resins, acrylic resins, and olefin resins.

The polycarbonate-based urethane resin may be a reaction product of a polyol, including polycarbonate polyol, and a polyisocyanate. Alternatively, the polycarbonate-based urethane resin may be a reaction product of a polyol, including a polycarbonate polyol and a polyol having a hydrophilic group, and a polyisocyanate. When a polyurethane having a urea bond is used as the polycarbonate-based urethane resin, a reaction product of a polyol, including a polycarbonate polyol, and a polyisocyanate with a chain extender such as a polyamine may be used.

The polycarbonate polyol can be, for example, a reaction product of a carbonate ester and a low molecular weight polyol, preferably a linear aliphatic diol.

The carbonate ester that can be used includes methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate, etc.

Examples of low molecular weight polyols that can react with the carbonate ester include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanedioic acid. Examples of the usable polyol include dihydroxy compounds having a relatively low molecular weight, such as 1,11-undecanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol-A, bisphenol-F, and 4,4'-biphenol; polyether polyols, such as polyethylene glycol, polypropylene glycol, and polyoxytetramethylene glycol; and polyester polyols, such as polyhexamethylene adipate, polyhexamethylene succinate, and polycaprolactone.

The polyisocyanate can be the same as the polyisocyanate having hydrophilic groups that can be used for the polyether-based urethane resins mentioned above.

The polyol having a hydrophilic group can be the same as the polyol having a hydrophilic group that can be used for the polyether-based urethane resin described above.

Examples of chain extenders such as polyamines include diamines such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, and 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, and N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, and dipropylenetriamine. and triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic dihydrazide, adipic dihydrazide, glutaric dihydrazide, sebacic dihydrazide, isophthalic dihydrazide; β-semicarbazide propionic hydrazide, 3-semicarbazide-propyl-carbazate, and semicarbazide-3-semicarbazidemethyl-3,5,5-trimethylcyclohexane can be used, and the use of hydrazine is preferred in order to obtain an ink that is less likely to cause clogging and that can be used to produce printed matter that has excellent washing fastness.

The polyamine is preferably used in such a range that the equivalent weight of the amino groups in the polyamine relative to the equivalent weight of the isocyanate groups in the urethane prepolymer, which is the reaction product of the polyol and polyisocyanate, is 0.01 to 1.0 (equivalent ratio), more preferably 0.01 to 0.5 (equivalent ratio), and even more preferably 0.01 to 0.3 (equivalent ratio).

The polyester-based urethane resin can be a reaction product of a polyol, including polyester polyol, and a polyisocyanate. Examples of polyester polyols that can be used include reaction products of a diol and a dicarboxylic acid, products obtained by dehydration condensation of a hydroxycarboxylic acid alone or in combination with a diol or dicarboxylic acid, and ring-opening polymerization products of cyclic ester compounds such as ε-caprolactone.

Examples of the diol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone, and alkylene oxide adducts thereof.

Examples of the dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid.

Examples of the hydroxycarboxylic acid include p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, etc.

In addition to the above, other polyols that can be used include relatively low molecular weight polyols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone and alkylene oxide adducts thereof, glycerin, trimethylolethane, trimethylolpropane, sorbitol, and pentaerythritol, which can be used alone or in combination of two or more.

There are no particular restrictions on the acrylic resin, and homopolymers or copolymers of (meth)acrylate, copolymers of (meth)acrylate and other vinyl monomers, etc. can be used.

(Pigment)
The inkjet textile printing ink of the present invention contains a pigment.
The pigment is not particularly limited, and any known and commonly used pigment such as an organic pigment or an inorganic pigment that is normally used in conventional screen printing or aqueous inkjet recording inks can be used. Furthermore, a colorant in which the pigment is coated with a resin can also be used as the pigment. In the present invention, the term "color ink" includes pigments having a color other than white, and includes black ink.

Furthermore, the pigment can be either an unacid-treated pigment or an acid-treated pigment, and can be used in either dry powder or wet cake form.

Examples of inorganic pigments that can be used include iron oxide, titanium oxide, and carbon black produced by methods such as the contact method, furnace method, or thermal method.

Examples of organic pigments that can be used include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), lake pigments (e.g., basic dye-type chelates, acid dye-type chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc.

Specific examples of the pigments used in black ink include Mitsubishi Chemical Corporation's No. 2300, No. 2200B, No. 900, No. 980, No. 960, No. 950, No. 33, No. 40, No. 45, No. 45L, and No. 52, HCF88, MCF88, MA7, MA8, MA100, etc. manufactured by Columbia Corporation; Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. manufactured by Cabot Corporation; Regal 400R, Regal 330R, Regal 660R, Mogul L, Mogul 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. manufactured by Degussa Corporation; Color Black, manufactured by Degussa Corporation; Carbon blacks such as FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, V, 1400U, Special Black 6, 5, 4, 4A, NIPEX150, NIPEX160, NIPEX170, and NIPEX180 can be used.

Specific examples of pigments used in yellow ink include C.I. Pigment Yellow 1, 2, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 174, 180, and 185.

Specific examples of pigments used in magenta inks include C.I. Pigment Violet 19, C.I. Pigment Red 5, 7, 12, 48(Ca), 48(Mn), 57(Ca), 57:1, 112, 122, 123, 146, 168, 176, 184, 185, 202, and 209, as well as mixtures or solid solutions of at least two or more pigments selected from these pigments.

Specific examples of pigments used in cyan ink include C.I. Pigment Blue 1, 2, 3, 15, 15:3, 15:4, 15:6, 16, 22, 60, 63, 66, etc.

Specific examples of pigments used in red ink include one or more selected from the group consisting of C.I. Pigment Red 17, 49:2, 112, 149, 150, 177, 178, 179, 188, 254, 255, and 264.

Specific examples of pigments used in orange ink include C.I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63, 64, 71, 73, and 81.

Specific examples of pigments used in green ink include C.I. Pigment Green 7, 10, 36, 58, 59, etc.

Specific examples of pigments used in violet ink include C.I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50, etc.

In order to maximize the effects of the present invention, the ink of the present invention is preferably a white ink containing a white pigment as a pigment. Specific examples of white pigments that can be used in this white ink include alkaline earth metal sulfates, carbonates, finely divided silica, synthetic silicates, and other silicas, calcium silicate, alumina, alumina hydrate, titanium oxide, zinc oxide, talc, clay, and the like. These may be surface-treated. Of these, titanium oxide is preferred, and alumina-treated titanium oxide is more preferred.

The pigments mentioned above can be used alone or in combination of two or more types.

In order to ensure that the pigment is present stably in the ink, it is preferable that measures be taken to ensure that it is well dispersed in an aqueous medium such as water.

Examples of the means include:
(i) A method in which a pigment is dispersed in an aqueous medium such as water together with a pigment dispersant by a dispersion method described below; (ii) A method in which a self-dispersing pigment in which a dispersibility-imparting group (hydrophilic functional group and/or a salt thereof) is bonded to the surface of the pigment directly or indirectly via an alkyl group, an alkyl ether group, an aryl group, or the like is dispersed and/or dissolved in an aqueous medium such as water.

The self-dispersing pigment can be, for example, a pigment that has been subjected to physical or chemical treatment, resulting in dispersibility-imparting groups or active species having dispersibility-imparting groups being bonded (grafted) to the surface of the pigment. The self-dispersing pigment can be produced, for example, by vacuum plasma treatment, oxidation treatment with hypohalous acid and/or hypohalous acid salts, or oxidation treatment with ozone, a wet oxidation method in which the pigment surface is oxidized with an oxidizing agent in water, or a method in which p-aminobenzoic acid is bonded to the pigment surface to bond a carboxyl group via a phenyl group.

Water-based inks containing self-dispersing pigments do not require the addition of pigment dispersants, making it easy to prepare inks with excellent ejection stability and virtually no foaming caused by pigment dispersants. Furthermore, water-based inks containing self-dispersing pigments are easy to handle and can contain more pigment because the significant increase in viscosity caused by pigment dispersants is suppressed, making them suitable for producing printed materials with high print density.

Commercially available self-dispersing pigments can also be used, including Microjet CW-1 (trade name, manufactured by Orient Chemical Industries Co., Ltd.), CAB-O-JET 200, and CAB-O-JET 300 (all trade names, manufactured by Cabot Corporation).

In order to maintain the excellent dispersion stability of the pigment and improve the print density and washability of the printed material, it is preferable to use the pigment in a range of 1% to 20% by mass, and more preferably in a range of 2% to 15% by mass, of the total amount of the ink.

(Pigment dispersant)
The pigment dispersant has the function of dispersing the pigment.

Examples of pigment dispersants that can be used include polyvinyl alcohols, polyvinylpyrrolidones, acrylic resins such as acrylic acid-acrylic acid ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, styrene-α-methylstyrene-acrylic acid copolymers, and styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymers, as well as aqueous resins such as styrene-maleic acid copolymers, styrene-maleic anhydride copolymers, and vinylnaphthalene-acrylic acid copolymers, and salts of these aqueous resins. Examples of pigment dispersants that can be used include the Ajisper PB series from Ajinomoto Fine-Techno Co., Ltd., the Disperbyk series from BYK Japan, the EFKA series from BASF, the SOLSPERSE series from Lubrizol Japan, and the TEGO series from Evonik.

The polymer (E) described below can also be used as the pigment dispersant, which can significantly reduce coarse particles and, as a result, impart the good ejection stability required when the ink is ejected using an inkjet method.

The polymer (E) may be one having an anionic group, and it is particularly preferable to use a polymer with a number average molecular weight in the range of 1,000 to 6,000 that has a solubility in water of 0.1 g/100 ml or less and is capable of forming fine particles in water when the neutralization rate of the anionic group with a basic compound is 100%.

The solubility of the polymer (E) in water was defined as follows: 0.5 g of polymer (E), whose particle size had been adjusted to the range of 250 μm to 90 μm using sieves with 250 μm and 90 μm openings, was sealed in a bag made of 400 mesh wire mesh, immersed in 50 ml of water, and left to stand for 24 hours with gentle stirring at 25°C. After 24 hours of immersion, the 400 mesh wire mesh containing the polymer (E) was dried for 2 hours in a dryer set at 110°C. The change in weight of the 400 mesh wire mesh containing the polymer (E) before and after immersion in water was measured, and the solubility was calculated using the following formula.

In the present invention, whether or not fine particles are formed in water when the neutralization rate of the anionic groups with the basic compound is 100% was determined as follows.
(1) The acid value of the polymer (E) is measured in advance by an acid value measurement method based on JIS test method K 0070-1992. Specifically, 0.5 g of the polymer (E) is dissolved in tetrahydrofuran, and the acid value is determined by titration with a 0.1 M alcoholic solution of potassium hydroxide using phenolphthalein as an indicator.
(2) 1 g of polymer (E) is added to 50 ml of water, and then a 0.1 mol/L aqueous potassium hydroxide solution is added in an amount sufficient to neutralize the resulting acid value 100% to achieve 100% neutralization.
(3) The 100% neutralized solution is irradiated with ultrasonic waves in an ultrasonic cleaner (SND Corporation ultrasonic cleaner US-102, 38 kHz self-oscillation) at a temperature of 25°C for 2 hours, and then left at room temperature for 24 hours.

After leaving it for 24 hours, a sample of the liquid at a depth of 2 centimetres from the liquid surface is taken and the presence of fine particles is confirmed by using a dynamic light scattering particle size distribution measuring device (Nikkiso Co., Ltd., dynamic light scattering particle size measuring device "Microtrac Particle Size Distribution Meter UPA-ST150") to determine whether light scattering information due to the formation of fine particles can be obtained.

To further improve the stability of the microparticles formed by polymer (E) in water, the particle diameter of the microparticles is preferably in the range of 5 nm to 1000 nm, more preferably in the range of 7 nm to 700 nm, and most preferably in the range of 10 nm to 500 nm. Furthermore, while a narrower particle size distribution of the microparticles tends to result in better dispersion stability, even a broader particle size distribution can produce an ink with better dispersion stability than conventional inks. The particle diameter and particle size distribution were measured using a dynamic light scattering particle size distribution analyzer (Microtrac UPA-ST150 dynamic light scattering particle size analyzer manufactured by Nikkiso Co., Ltd.), similar to the method for measuring the microparticles.

The neutralization rate of polymer (E) was determined using the following formula:

The acid value of the polymer (E) was measured in accordance with JIS test method K 0070-1992. Specifically, 0.5 g of the sample was dissolved in tetrahydrofuran and titrated with a 0.1 M alcoholic solution of potassium hydroxide using phenolphthalein as an indicator.

The number average molecular weight of the polymer (E) is preferably in the range of 1,000 to 6,000, more preferably 1,300 to 5,000, and more preferably 1,500 to 4,500, which can effectively suppress aggregation of the pigment in the solvent (C) and is more preferable for obtaining an ink with good dispersion stability of the pigment.

The number average molecular weight is a polystyrene-equivalent value measured by GPC (gel permeation chromatography), specifically measured under the following conditions:

(Method for measuring number average molecular weight (Mn))
Measurement was carried out by gel permeation chromatography (GPC) under the following conditions.
Measurement device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.

"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D. x 30cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: tetrahydrofuran Flow rate: 1.0 mL/min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was prepared using the following standard polystyrene.
(standard polystyrene)
"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
Tosoh Corporation's "TSKgel Standard Polystyrene A-2500"
Tosoh Corporation's "TSKgel Standard Polystyrene A-5000"
"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation
Tosoh Corporation's "TSKgel Standard Polystyrene F-550"

The polymer (E) used preferably has a surface tension of 30 dyn/cm or more, more preferably 40 dyn/cm or more, and particularly preferably 65 dyn/cm to 75 dyn/cm, which is close to the surface tension of water. The surface tension is measured on a 100% neutralized polymer solution obtained by adding 1 g of polymer (E) to water and then adding a 0.1 mol/L potassium hydroxide aqueous solution sufficient to neutralize the resulting acid value 100%.

The polymer (E) can be a polymer that is insoluble or poorly soluble in water when unneutralized and forms fine particles when 100% neutralized. There are no particular limitations on the polymer, as long as it has a hydrophobic group in each molecule in addition to an anionic group, which is a hydrophilic group.

An example of such a polymer is a block polymer having a polymer block having a hydrophobic group and a polymer block having an anionic group. In polymer (E), the number of anionic groups and water solubility are not necessarily determined by the acid value or the number of anionic groups at the time of polymer design. For example, even among polymers with the same acid value, polymers with lower molecular weights tend to have higher water solubility, while polymers with higher molecular weights tend to have lower water solubility. For this reason, in the present invention, polymer (E) is determined by its water solubility.

The polymer (E) may be a homopolymer, but is preferably a copolymer. It may be a random polymer, a block polymer, or an alternating polymer, but is preferably a block polymer. The polymer may also be a branched polymer, but is preferably a linear polymer.

Furthermore, it is preferable that the polymer (E) is a vinyl polymer from the viewpoint of design freedom, and as a method for producing a vinyl polymer having the desired molecular weight and solubility characteristics in the present invention, it is preferable to produce it by using "living polymerization" such as living radical polymerization, living cationic polymerization, or living anionic polymerization.

In particular, it is preferable that the polymer (E) is a vinyl polymer produced using a (meth)acrylate monomer as one of the raw materials, and living radical polymerization and living anionic polymerization are preferred methods for producing such vinyl polymers, with living anionic polymerization being more preferred from the standpoint of being able to more precisely design the molecular weight of the block polymer and each segment.

The polymer (E) produced by living anionic polymerization is specifically a polymer represented by general formula (3).

In general formula (3), A1 represents an organolithium initiator residue, A2 represents a polymer block having a hydrophobic group, A3 represents a polymer block containing an anionic group, n represents an integer from 1 to 5, and B represents an aromatic group or an alkyl group.

In general formula (3), A1 represents an organolithium initiator residue. Specific examples of organolithium initiators include alkyllithiums such as methyllithium, ethyllithium, propyllithium, butyllithium (n-butyllithium, sec-butyllithium, iso-butyllithium, tert-butyllithium, etc.), pentyllithium, hexyllithium, methoxymethyllithium, and ethoxymethyllithium; phenylalkylenelithiums such as benzyllithium, α-methylstyryllithium, 1,1-diphenyl-3-methylpentyllithium, 1,1-diphenylhexyllithium, and phenylethyllithium; alkenyllithiums such as vinyllithium, allyllithium, propenyllithium, and butenyllithium; alkynyllithiums such as ethynyllithium, butynyllithium, pentynyllithium, and hexynyllithium; aryllithiums such as phenyllithium and naphthyllithium; heterocyclic lithiums such as 2-thienyllithium, 4-pyridyllithium, and 2-quinolyllithium; and alkyllithium-magnesium complexes such as tri(n-butyl)magnesiumlithium and trimethylmagnesiumlithium.

In organolithium initiators, the bond between the organic group and lithium cleaves, leaving an active terminal on the organic group side, from which polymerization begins. Therefore, an organic group derived from the organolithium is bonded to the end of the resulting polymer. In this invention, the organic group derived from the organolithium bonded to the polymer end is referred to as the organolithium initiator residue. For example, in a polymer using methyllithium as the initiator, the organolithium initiator acid group is a methyl group, and in a polymer using butyllithium as the initiator, the organolithium initiator acid group is a butyl group.

In the general formula (3), A2 represents a polymer block having a hydrophobic group. As described above, A2 is preferably a group that exhibits high adsorption to a pigment when it comes into contact with the pigment, in addition to achieving an appropriate balance of solubility. From this viewpoint, A2 is preferably a polymer block of a monomer having an aromatic ring or a heterocyclic ring.
Specifically, the polymer block of a monomer having an aromatic ring or a heterocyclic ring is a polymer block of a homopolymer or copolymer obtained by homopolymerizing or copolymerizing a monomer having an aromatic ring, such as a styrene-based monomer, or a monomer having a heterocyclic ring, such as a vinylpyridine-based monomer.

Examples of monomers having an aromatic ring include styrene-based monomers such as styrene, p-tert-butylstyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, p-tert-butoxystyrene, m-tert-butoxystyrene, p-tert-(1-ethoxymethyl)styrene, m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, α-methylstyrene, and p-methyl-α-methylstyrene, as well as vinylnaphthalene and vinylanthracene.

Furthermore, examples of monomers having a heterocycle include vinylpyridine-based monomers such as 2-vinylpyridine and 4-vinylpyridine. These monomers can be used alone or in combination of two or more.

In the general formula (3), A3 represents a polymer block containing an anionic group. As described above, A3 has the purpose of imparting appropriate solubility and also the purpose of imparting dispersion stability in water when a pigment dispersion is formed.
Examples of the anionic group in the polymer block A3 include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Among these, a carboxyl group is preferred because of its preparation, the wide variety of monomers available, and ease of availability. Two carboxyl groups may be dehydrated and condensed intramolecularly or intermolecularly to form an acid anhydride group.

There are no particular limitations on the method for introducing the anionic group A3. For example, if the anionic group is a carboxyl group, the polymer block (PB1) may be a homopolymer or copolymer obtained by homopolymerizing (meth)acrylic acid or copolymerizing it with other monomers, or the polymer block (PB2) may be a homopolymer or copolymer obtained by homopolymerizing or copolymerizing (meth)acrylate with other monomers, which has protecting groups that can be restored to anionic groups by deprotection, and in which some or all of the protecting groups that can be restored to anionic groups have been restored to anionic groups.

Note that the (meth)acrylic acid used in the polymer block A3 is a general term for acrylic acid and methacrylic acid, and (meth)acrylate is a general term for acrylate and methacrylate.

Specific examples of (meth)acrylic acid and (meth)acrylates include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, allyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-lauryl (meth)acrylate, n-tridecyl (meth)acrylate, and n- Stearyl, phenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, adamantyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, trifluoroethyl (meth)acrylate, (meth)acrylic acid Tetrafluoropropyl, pentafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, pentadecafluorooctyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, N,N-dimethyl(meth)acrylamide, (meth)acryloylmorpholine, (meth)acrylonitrile, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, polyethylene glycol-polypropylene glycol (meth)acrylate, polyethylene glycol-polybutylene glycol (meth)acrylate, polypropylene glycol-polybutylene glycol (meth)acrylate Examples of the polyalkylene oxide group-containing (meth)acrylate include polyalkylene glycol (meth)acrylates such as acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, butoxypolyethylene glycol (meth)acrylate, octoxypolyethylene glycol (meth)acrylate, lauroxypolyethylene glycol (meth)acrylate, stearoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and octoxypolyethylene glycol-polypropylene glycol (meth)acrylate. These monomers can be used alone or in combination of two or more.

In living anionic polymerization, if the monomer used has a group with an active proton, such as an anionic group, the active end of the living anionic polymerization polymer immediately reacts with the group with the active proton and is deactivated, resulting in no polymer being obtained. Since it is difficult to polymerize a monomer with a group with an active proton directly in living anionic polymerization, it is preferable to polymerize the monomer while protecting the group with the active proton, and then regenerate the group with the active proton by deprotecting the protecting group.

For these reasons, it is preferable to use a monomer containing a (meth)acrylate having a protecting group that can be regenerated into an anionic group by deprotection in the polymer block A3. Using such a monomer can prevent the aforementioned polymerization inhibition during polymerization. Furthermore, the anionic group protected by the protecting group can be regenerated into an anionic group by deprotecting it after obtaining the block polymer.

For example, if the anionic group is a carboxyl group, the carboxyl group can be regenerated by esterifying the carboxyl group and then deprotecting it by hydrolysis or other methods in a subsequent step. In this case, protecting groups convertible to carboxyl groups are preferably groups having an ester bond, such as primary alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, and n-butoxycarbonyl; secondary alkoxycarbonyl groups such as isopropoxycarbonyl and sec-butoxycarbonyl; tertiary alkoxycarbonyl groups such as t-butoxycarbonyl; phenylalkoxycarbonyl groups such as benzyloxycarbonyl; and alkoxyalkylcarbonyl groups such as ethoxyethylcarbonyl.

When the anionic group is a carboxyl group, usable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), Examples of the (meth)acrylate include alkyl (meth)acrylates such as octadecyl (meth)acrylate (stearyl (meth)acrylate), tridecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), nonadecyl (meth)acrylate, and icosanyl (meth)acrylate; phenyl alkylene (meth)acrylates such as benzyl (meth)acrylate; and alkoxy alkyl (meth)acrylates such as ethoxyethyl (meth)acrylate. These (meth)acrylates can be used alone or in combination of two or more. Among these (meth)acrylates, t-butyl (meth)acrylate and benzyl (meth)acrylate are preferred because they are easily converted into a carboxyl group. In addition, t-butyl (meth)acrylate is more preferred in terms of industrial availability.

In general formula (3), B represents an aromatic group or an alkyl group having 1 to 10 carbon atoms. Also, n represents an integer from 1 to 5.

In living anionic polymerization, when attempting to directly polymerize a (meth)acrylate monomer onto the active end of a highly nucleophilic styrene-based polymer, polymerization may not be possible due to nucleophilic attack on the carbonyl carbon. For this reason, when polymerizing the (meth)acrylate monomer with A1-A2, a reaction modifier is used to adjust the nucleophilicity before polymerizing the (meth)acrylate monomer. B in general formula (3) is a group derived from the reaction modifier. Specific examples of reaction modifiers include diphenylethylene, α-methylstyrene, and p-methyl-α-methylstyrene.

By adjusting the reaction conditions, living anionic polymerization can be carried out using a batch method similar to that used in conventional free-radical polymerization. Alternatively, continuous polymerization using a microreactor can also be used. Because microreactors allow for good miscibility between the polymerization initiator and monomer, reactions start simultaneously, and the temperature is uniform, allowing for consistent polymerization rates, resulting in a narrow molecular weight distribution for the polymer produced. At the same time, the stable growing ends make it easy to produce block copolymers in which the two block components do not mix. Furthermore, the good controllability of the reaction temperature makes it easy to suppress side reactions.

A general method for living anionic polymerization using a microreactor will be described with reference to FIG. 1, which is a schematic diagram of a microreactor.
A first monomer and a polymerization initiator that initiates polymerization are introduced from tube reactors P1 and P2 (7 and 8 in Figure 1), respectively, into a T-shaped micromixer M1 (1 in Figure 1) equipped with a flow path capable of mixing multiple liquids, and the first monomer is subjected to living anionic polymerization in the T-shaped micromixer M1 to form a first polymer (Step 1).

Next, the obtained first polymer is transferred to a T-shaped micromixer M2 (2 in FIG. 1), and in the mixer M2, the growing end of the obtained polymer is trapped by a reaction control agent introduced from a tube reactor P3 (9 in FIG. 1) to control the reaction (step 2).
In this case, the number n in the general formula (3) can be controlled by the type and amount of the reaction adjuster used.

Next, the first polymer that has undergone reaction adjustment in the T-shaped micromixer M2 is transferred to the T-shaped micromixer M3 (3 in Figure 1), where the second monomer introduced from the tube reactor P4 and the first polymer that has undergone reaction adjustment are continuously subjected to living anionic polymerization in the same mixer M3 (step 3).

The reaction is then quenched with a compound with an active proton, such as methanol, to produce a block copolymer.

When the polymer (E) represented by the general formula (3) of the present invention is produced in the microreactor, a monomer having an aromatic ring or a heterocycle is used as the first monomer, and reacted with an organolithium initiator as the initiator, to obtain a polymer block of the monomer having an aromatic ring or a heterocycle (A2) (one end of the polymer block A2 is bonded to an organic group which is a residue of the organolithium initiator (A1)).
Next, after adjusting the reactivity of the growing terminal using a reaction adjuster, a monomer containing a (meth)acrylate having a renewable protecting group on the anionic group is reacted as the second monomer to obtain a polymer block.

After this, the anionic group is regenerated by a deprotection reaction such as hydrolysis, thereby obtaining the polymer block A3 containing the anionic group.

We will describe in detail how the ester bond of the protecting group that can be regenerated into the anionic group can be regenerated into the anionic group by a deprotection reaction such as hydrolysis.

The hydrolysis reaction of ester bonds proceeds under both acidic and basic conditions, but the conditions vary slightly depending on the group containing the ester bond. For example, if the group containing the ester bond is a primary alkoxycarbonyl group such as a methoxycarbonyl group or a secondary alkoxycarbonyl group such as an isopropoxycarbonyl group, a carboxyl group can be obtained by hydrolysis under basic conditions. In this case, examples of basic compounds that can be used under basic conditions include metal hydroxides such as sodium hydroxide and potassium hydroxide.

Furthermore, when the group having an ester bond is a tertiary alkoxycarbonyl group such as a t-butoxycarbonyl group, a carboxyl group can be obtained by hydrolysis under acidic conditions. Examples of acidic compounds that can be used under acidic conditions include mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; Brösted acids such as trifluoroacetic acid; and Lewis acids such as trimethylsilyl triflate. Reaction conditions for hydrolysis of a t-butoxycarbonyl group under acidic conditions are disclosed, for example, in "Experimental Chemistry Lectures 16: Synthesis of Organic Compounds IV," 5th Edition, edited by the Chemical Society of Japan.

Furthermore, a method of converting a t-butoxycarbonyl group into a carboxyl group may also be used in place of the above-mentioned acid. Examples of the cation exchange resin include resins having an acid group, such as a carboxyl group (—COOH) or a sulfo group (—SO ₃ H), on the side chain of the polymer chain. Among these, a strongly acidic cation exchange resin having a sulfo group on the side chain of the resin is preferred because it can accelerate the progress of the reaction. Commercially available cation exchange resins that can be used in the present invention include, for example, the strongly acidic cation exchange resin "Amberlite" manufactured by Organo Corporation. The amount of this cation exchange resin used is preferably in the range of 5 to 200 parts by mass, more preferably 10 to 100 parts by mass, per 100 parts by mass of the polymer represented by the general formula (3) above, in order to ensure effective hydrolysis.

Furthermore, if the group containing an ester bond is a phenylalkoxycarbonyl group such as a benzyloxycarbonyl group, it can be converted to a carboxyl group by hydrogenation reduction. The reaction conditions are room temperature, in the presence of a palladium catalyst such as palladium acetate, and using hydrogen gas as a reducing agent, which allows the phenylalkoxycarbonyl group to be quantitatively regenerated into a carboxyl group.

As mentioned above, the reaction conditions for conversion to a carboxyl group vary depending on the type of group containing an ester bond. For example, a polymer obtained by copolymerizing t-butyl (meth)acrylate and n-butyl (meth)acrylate as raw materials for A3 will contain t-butoxycarbonyl groups and n-butoxycarbonyl groups. Under acidic conditions that hydrolyze t-butoxycarbonyl groups, n-butoxycarbonyl groups do not, allowing for selective hydrolysis of only the t-butoxycarbonyl groups, enabling deprotection to a carboxyl group. Therefore, the acid value of the hydrophilic block (A3) can be adjusted by appropriately selecting a raw material monomer for A3, which contains a (meth)acrylate with a recyclable protecting group on the anionic group.

Furthermore, in polymer (E) represented by general formula (3), it is advantageous to use a block copolymer in which the polymer blocks are regularly bonded in blocks of a certain length, rather than a random copolymer in which the polymer blocks (A2) and (A3) are randomly arranged and bonded, in order to improve the stability of the aqueous pigment dispersion in which the pigment is dispersed in water by the polymer (E). The aqueous pigment dispersion is a raw material used in the production of ink, and may be a liquid in which the pigment is dispersed at a high concentration in water by the polymer (E). The molar ratio A2:A3 of polymer block (A2) to polymer block (A3) is preferably in the range of 100:10 to 100:500, and a molar ratio A2:A3 of 100:10 to 100:450 is more preferable in order to obtain an ink that can maintain the good ejection stability required, for example, when ejecting ink using an inkjet method, and can produce printed materials with even better color development.

In the polymer (E) represented by the general formula (3), the number of aromatic or heterocyclic monomers constituting the polymer block (A2) is preferably in the range of 5 to 40, more preferably in the range of 6 to 30, and most preferably in the range of 7 to 25. The number of anionic groups constituting the polymer block (A3) is preferably in the range of 3 to 20, more preferably in the range of 4 to 17, and most preferably in the range of 5 to 15.
The molar ratio A2:A3 of the polymer block (A2) to the polymer block (A3), expressed as the molar ratio of the number of moles of aromatic rings or heterocyclic rings constituting the polymer block (A2) to the number of moles of anionic groups constituting the polymer block (A3), is preferably 100:7.5 to 100:400.

Furthermore, the acid value of polymer (E) represented by general formula (3) is preferably 40 mgKOH/g to 400 mgKOH/g, more preferably 40 mgKOH/g to 300 mgKOH/g, and 40 mgKOH/g to 190 mgKOH/g is more preferable in order to obtain an ink that can maintain the good ejection stability required when ejecting ink using an inkjet method, for example, and can produce printed materials that are even better in terms of abrasion resistance, etc.

The acid value of the polymer in this invention was determined using the same acid value measurement method as the method used to measure the fine particles of polymer (E) above.

In the ink, it is preferable that the anionic groups of the polymer (E) are neutralized.

Any known or commonly used basic compound can be used to neutralize the anionic groups of the polymer (E), including inorganic basic substances such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and organic basic compounds such as ammonia, triethylamine, and alkanolamine.

The neutralization amount of the polymer (E) present in the aqueous pigment dispersion does not need to be 100% based on the acid value of the polymer. Specifically, it is preferable that the polymer (E) be neutralized so that the neutralization rate is 20% to 200%, and more preferably 80% to 150%.

The polymer (E) can also be preferably used as a dispersing aid in ink, rather than as a dispersant in aqueous pigment dispersions. Using the polymer (E) as a dispersing aid can improve the long-term dispersion stability of the pigment and also improve recyclable filtration. In this case, the polymer (E) can be added during the production of the pigment dispersion, or during the production of ink. When using the polymer (E) as a dispersing aid, the ratio of pigment to dispersant to polymer (E) is preferably pigment:dispersant:polymer (E) = 1:0.03:0.01 to 1:0.5:0.2.

(Other ink components)
The inkjet textile printing ink of the present invention may contain other ink components in addition to the pigment and binder resin, such as water, a water-soluble solvent, a surfactant, a dispersing aid, a sugar, a preservative, a viscosity adjuster, a pH adjuster, a chelating agent, a dispersing aid, an antioxidant, and an ultraviolet absorber, as needed.

(water)
As the water, specifically, pure water or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, etc. can be used.

(Water-soluble solvent)
Examples of the water-soluble solvent include glycerin, diglycerin, polyglycerin, diglycerin fatty acid esters, polyoxypropylene (n) polyglyceryl ethers, polyoxyethylene (n) polyglyceryl ethers, acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, methanol, ethanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, 2-methoxyethanol, tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, dimethylformamide, N-methylpyrrolidone, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, butanediol, pentanediol, hexanediol, and diols of the same group as these, propylene glycol laurate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol ether, dipropylene glycol ether, and cellosolves containing triethylene glycol ether, methanol, ethanol, isopropyl alcohol, Examples of suitable alcohols that can be used include butyl alcohols such as 1-propanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol, pentyl alcohol, and alcohols of the same family as these, sulfolane, lactones such as γ-butyrolactone, lactams such as N-(2-hydroxyethyl)pyrrolidone, 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, 4-methoxy-4-methyl-2-pentanone, and ethyl lactate, which can be used alone or in combination of two or more.

Of the above, it is preferable to use glycerin, diglycerin, polyglycerin, diglycerin fatty acid esters, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and propylene glycol as the water-soluble solvent. Using a combination of glycerin with ethylene glycol or propylene glycol is preferable in order to obtain an ink that penetrates into recording media such as fabrics, dries easily, and can prevent drying and solidification in the nozzles and filters of ink-circulating inkjet heads.

The water and water-soluble solvent form the aqueous medium of the inkjet textile printing ink of the present invention. The aqueous medium is preferably used in a range of 50% to 95% by mass relative to the total amount of the ink, and using it in a range of 65% to 95% by mass is particularly preferred for preventing the ink from drying near the nozzle, making it easy to adjust the ease of drying after landing on the recording medium, and obtaining an ink that is clear and capable of producing printed materials with a good texture, especially when used to print on fabrics. The aqueous medium also includes the water and water-soluble solvent contained in the pigment dispersion and binder resin.

(Surfactant)
The surfactant can be used to improve the leveling properties of the ink by reducing the surface tension of the ink, etc. Furthermore, the surfactant can prevent mottle from occurring in the printed matter by allowing the ink ejected from the ejection port of the inkjet head to wet and spread well on the surface of the fabric after landing on the fabric.

The surfactant may be any of a variety of anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc., and it is preferable to use anionic surfactants or nonionic surfactants.

Examples of the anionic surfactant include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfate ester salts of higher fatty acid esters, sulfonates of higher fatty acid esters, sulfate ester salts and sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates. Specific examples of these include dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenylsulfonate, and dibutylphenylphenol disulfonate.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, fatty acid alkylolamides, alkylalkanolamides, acetylene glycol, oxyethylene adducts of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymers. Of these, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylolamides, acetylene glycol, oxyethylene adducts of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymers are preferred. Among these, acetylene glycol and oxyethylene adducts of acetylene glycol are more preferred because they reduce the contact angle of ink droplets with the recording medium and allow for the production of good printed matter.

Other surfactants that can be used include silicone surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; and biosurfactants such as spiculisporic acid, rhamnolipid, and lysolecithin.

It is preferable to use a surfactant with an HLB in the range of 4 to 20 in order to stably maintain the surfactant dissolved in the ink, which has water as the main solvent.

The surfactant is preferably used in a range of 0.001% to 2% by mass, more preferably 0.001% to 1.5% by mass, and most preferably 0.1% to 1.5% by mass, relative to the total amount of the ink. Inkjet inks containing the surfactant in the above range exhibit good wettability of the ejected droplets on the fabric surface, provide sufficient wetting and spreading on the fabric, and are preferred for preventing mottle in printed matter. Furthermore, inks containing the surfactant in the above range exhibit the effect of improving wettability to the fabric.

Sugars include monosaccharides and polysaccharides, such as glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitose, maltose, cellobiose, sucrose, trehalose, maltotriose, as well as alginic acid and its salts, cyclodextrins, and celluloses.

Preservatives include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazolin-3-one (Arch Chemicals' Proxel GXL, Proxel XL-2, Proxel LV, Proxel AQ, Proxel BD20, and Proxel DL), etc.

Specific examples of viscosity adjusters include primarily water-soluble natural or synthetic polymers such as carboxymethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, gum arabic, and starch.

Specific examples of pH adjusters include collidine, imidazole, phosphoric acid, 3-(N-morpholino)propanesulfonic acid, tris(hydroxymethyl)aminomethane, boric acid, etc.

Specific examples of chelating agents include ethylenediaminetetraacetic acid, ethylenediaminediacetic acid, nitrilotriacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, N-hydroxyethylethylenediaminetriacetic acid, iminodiacetic acid, uramildiacetic acid, 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid, malonic acid, succinic acid, glutaric acid, maleic acid, and salts thereof (including hydrates).

Examples of antioxidants or UV absorbers include allophanates such as allophanate and methyl allophanate, biurets such as biuret, dimethyl biuret, and tetramethyl biuret, L-ascorbic acid and its salts, Ciba-Geigy's Tinuvin 328, 900, 1130, 384, 292, 123, 144, 622, 770, 292, Irgacor 252, 153, Irganox 1010, 1076, 1035, and MD1024, and lanthanide oxides.

(Method for producing inkjet printing ink)
The inkjet textile printing ink of the present invention can be produced by producing an aqueous pigment dispersion containing a pigment at a high concentration, and mixing the aqueous pigment dispersion with a polyether-based urethane resin as a binder resin, and, if necessary, other binder resins, an aqueous medium, a surfactant, and additives.

Examples of methods for producing the aqueous pigment dispersion include the following methods (1) to (3).
(1) A method of preparing an aqueous pigment dispersion by adding a pigment to a mixture containing a dispersing resin and water, and then dispersing the pigment in the mixture using a stirring and dispersing device.
(2) A method in which a pigment and a dispersing resin are kneaded using a kneader such as a two-roll mill or a mixer, and water and, if necessary, an organic solvent miscible with water are added to the resulting kneaded mixture, followed by preparing an aqueous pigment dispersion using a stirring and dispersing device.
(3) A method in which a pigment is added to a solution obtained by dissolving a dispersing resin in an organic solvent that is compatible with water, such as methyl ethyl ketone or tetrahydrofuran, and the like, and then the pigment is dispersed in the organic solution using a stirring and dispersing device, and then phase-inversion emulsification is carried out using an aqueous medium such as water, and the organic solvent is then distilled off to prepare an aqueous pigment dispersion.

Kneading machines include, but are not limited to, Henschel mixers, pressure kneaders, Banbury mixers, intensive mixers, planetary mixers, butterfly mixers, etc.

As stirring and dispersion equipment, for example, ultrasonic homogenizers, high-pressure homogenizers, paint shakers, ball mills, roll mills, sand mills, sand grinders, Dyno Mills, Dispermats, SC Mills, Nanomizers, etc. can be used alone or in combination of two or more types.

It is preferable to use an aqueous pigment dispersion containing 5% to 60% by mass of pigment based on the total amount of the aqueous pigment dispersion in order to obtain an ink that can produce printed materials with high image density and has excellent dispersion stability, and it is more preferable to use an aqueous pigment dispersion containing 10% to 50% by mass of pigment.

In addition, since coarse particles contained in aqueous pigment dispersions can cause deterioration of image characteristics, it is preferable to use aqueous pigment dispersions from which coarse particles have been removed by centrifugation or filtration, etc., before or after producing the ink.

When producing the aqueous pigment dispersion, the dispersion process may be followed by an impurity removal process using ion exchange or ultrafiltration, followed by post-treatment. Ion exchange can remove ionic substances such as cations and anions (divalent metal ions, etc.), while ultrafiltration can remove dissolved impurities (residual substances from pigment synthesis, excess components in the dispersion composition, resin not adsorbed to the organic pigment, contaminants, etc.). Known ion exchange resins are used for the ion exchange process. Known ultrafiltration membranes can be used for the ultrafiltration process, and either standard or double-capacity membranes may be used.

Methods for mixing the aqueous pigment dispersion obtained by the above method with the polyether-based urethane resin, etc. include, for example, a method of first preparing a mixture of the aqueous dispersion of the polyether-based urethane resin, etc., and then mixing the mixture with the aqueous pigment dispersion, or a method of mixing the aqueous pigment dispersion with the aqueous dispersion of the polyether-based urethane resin, and then further mixing other additives such as surfactants.

In the inkjet printing ink of the present invention obtained by the above method, it is preferable that the mass ratio of pigment to the total amount of the ink (pigment concentration) be 1% by mass to 20% by mass, in order to obtain sufficient image density and ensure good dispersion stability of the pigment in the ink.

The pH of the ink is preferably 7.0 or higher, more preferably 7.5 or higher, and even more preferably 8.0 or higher, in order to improve the storage stability and ejection stability of the ink and to improve the wetting spread, print density, and waterfastness when printed on fabrics that are highly or poorly ink-absorbent. The upper limit of the pH of the ink is preferably 11.0 or lower, more preferably 10.0 or lower, and even more preferably 9.5 or lower, in order to prevent deterioration of components that make up the ink application or ejection device (e.g., ink ejection ports, ink flow paths, etc.) and to reduce the effects of ink adhesion to skin.

The inkjet textile printing ink of the present invention can be used, for example, in a printing method using an ink circulation type inkjet head.

An example of a printing device equipped with an ink circulation type inkjet head is a printing device equipped with a head that has an ink inlet and outlet paths separate from the ink ejection nozzles, and has an ink circulation structure in which ink flowing out of the outlet path passes through the inlet path and is then supplied back to the inkjet head. Furthermore, a printing device equipped with a filter midway through the circulation structure is suitable for use.

It is preferable to use a filter with a pore size in the range of 5 μm to 20 μm, and it is preferable to use a filter with a pore size in the range of 5 μm to 10 μm in order to be effective in removing foreign matter that may be generated near the nozzle.

The ink tank that supplies the ink is not particularly limited, but a plastic bottle or a pouch-type ink bag may be used. It is also possible to use an ink tank or ink bag with a circulation function.

Examples of recording media that can be used when producing printed materials using the inkjet textile printing ink of the present invention and the printing method and printing device described above include fabrics and film substrates.

(Printing on fabric)
The fabric generally refers to a woven fabric made by weaving threads made of fibers such as cotton alternately in the warp and weft directions. The inkjet printing ink of the present invention is suitable not only for fabrics in the general sense, but also for media made of fibers such as nonwoven fabrics and knitted fabrics. The material can be fabrics made of any natural or synthetic fiber such as cotton, silk, wool, hemp, nylon, polyester, polyurethane, or rayon, or fabrics made of a blend of these fibers.

As a method for printing onto the fabric, for example, a method of printing the inkjet printing ink of the present invention onto the fabric using a printing device equipped with an ink circulation type inkjet head can be mentioned.

In this case, it is preferable that the shortest distance between the ink discharge ports of the ink circulation inkjet head and the fabric is set to 1 mm or more. The shortest distance is more preferably set to 2 mm or more, and can also be set to 3 mm or more, to prevent contact between the surface of the fabric (recording surface) and the ink discharge ports, even if the fabric is highly frayed or uneven, and to effectively prevent damage to the ink discharge ports and ink discharge defects caused by a decrease in the water-repellent function that the ink discharge ports often have. Furthermore, even if the distance between the surface of the fabric and the inkjet head is long, the upper limit of the distance is preferably 10 mm or less, and more preferably 5 mm or less, in order to produce printed matter without streaks.

The shortest distance may be the distance (gap) from the surface (x) having the ink ejection ports of the inkjet head to the position (y) where a perpendicular line to the surface (x) (an assumed perpendicular line to the surface (x)) intersects with the fabric.

At the shortest distance, the lower limit of the size of the ink droplets when ejected from the ink circulation type inkjet head is preferably 10 pl, more preferably 15 pl, and even more preferably 20 pl, and the upper limit is preferably 50 pl, more preferably 45 pl, and even more preferably 40 pl, which is preferable in order to produce printed materials with excellent image quality free of streaks, etc., and to obtain printed materials with even better washing resistance.

(transfer printing)
Furthermore, a printed matter obtained by printing the ink of the present invention onto a film substrate is called a transfer film, and a printed matter printed on a fabric can be obtained by overlapping the printed surface of the transfer film with the transfer-receiving surface of the fabric and performing thermal transfer. That is, a method for producing a printed matter of the present invention includes a step of printing the inkjet textile printing ink of the present invention onto a film substrate to obtain a transfer film, and a step of overlapping the printed surface of the transfer film with the transfer-receiving surface of the fabric and performing thermal transfer.

(Film substrate)
The film substrate may be a known transfer film substrate used in transfer printing methods for fabrics. The film substrate may have a single-layer structure consisting of only a base film, or may be a multilayer film in which other layers are formed on a base film. The film substrate is preferably a multilayer film having a base film and a release layer.

Examples of base films include polyolefin films such as polypropylene film, polyethylene film, and polypropylene film; polyester films such as polyethylene terephthalate film, polybutylene terephthalate film, and polyethylene naphthalate film; cellulose films such as diacetyl cellulose film and triacetyl cellulose film; polyurethane films; polyamide films; polyimide films; polyacrylate films; polymethacrylate films; and resin films such as polycarbonate films. Polyolefin and polyurethane films are preferred because they conform to the irregularities of the fabric fiber mesh, providing high fixability. On the other hand, polyester films are preferred, with polyethylene terephthalate film being more preferred, from the standpoints of excellent transfer quality and high color development. Therefore, it is preferable for the film substrate to include a polyester film, a polyolefin film, or a polyurethane film.

The release layer may be the same as the release layer found in known multilayer transfer films. The release layer may be either a silicone layer or a non-silicone layer, and is not particularly limited. Methods for forming the release layer on the base film include, but are not limited to, coating and lamination.

When the above film substrate has a multilayer structure, it may have layers other than the base film and release layer. Examples of such layers include an antistatic treatment layer.

It is preferable to preheat the above film substrate before printing.

A transfer film can be obtained by ejecting the inkjet textile printing ink onto the film substrate using an inkjet recording device. Any known inkjet recording device can be used, including inkjet recording devices equipped with continuous-jet (charge-controlled, spray, etc.) or on-demand (piezo, thermal, electrostatic suction, etc.) inkjet heads. Furthermore, using an inkjet recording device with an ink-circulating inkjet head is preferred for achieving the effects of the present invention.

In this case, it is preferable to set the shortest distance between the ink discharge ports of the ink circulation inkjet head and the fabric to 0.5 mm or more. Unlike fabric, film substrates have little fuzz or unevenness. Therefore, it is more important to prevent contact between the recording surface and the ink discharge ports and to produce streak-free printed matter than to effectively prevent damage to the ink discharge ports or ink discharge defects caused by a decrease in the water-repellent function that the ink discharge ports often have. Therefore, the upper limit of the distance is preferably 5 mm or less, and more preferably 3 mm or less. Furthermore, the lower limit of the distance is not particularly limited, but is more preferably 0.8 mm or more, and even more preferably 1 mm or more.

The inkjet textile printing ink may be dried on the film substrate. For example, this can be done by heating the ejected inkjet textile printing ink using a heating device such as a heater, hot plate, oven, hot air dryer, or near-infrared light. If water-soluble solvents contained in the inkjet textile printing ink remain in the printing layer, the remaining solvent may volatilize when the transfer film is heated for transfer to the transfer substrate, resulting in poor transfer quality. Therefore, the drying temperature is preferably 80°C or higher and 160°C or lower, and more preferably 100°C or higher and 150°C or lower. The drying time can be set appropriately depending on the drying temperature, for example, 1 minute to 10 minutes.

(thermal transfer)
The ink of the present invention can be inkjet printed onto a film substrate to form a transfer film, and the printed surface of the resulting transfer film can be overlaid on the surface of the fabric to be transferred, followed by a process of thermal transfer (sometimes referred to as the thermal transfer process) to obtain a printed matter of the present invention.
If necessary, the surface of the fabric to be transferred may be subjected to a pretreatment step to improve transferability and fixability. The pretreatment step may be, for example, a step of applying water or a pretreatment agent by spraying, using a coater, inkjet printing, or the like.

Thermal transfer refers to applying pressure while heating, and can be carried out by a known thermal transfer method. As a thermal transfer device, a heat press device or the like can be used.
The heating temperature is not particularly limited as long as the printing layer can be transferred, and is, for example, 125°C or higher, preferably 130°C or higher. On the other hand, the heating temperature is lower than the melting point of the film substrate of the transfer film, and is, for example, 200°C or lower, preferably 185°C or lower. Furthermore, if the heating temperature is higher than the softening point of the film substrate of the transfer film, the film substrate can conform to the unevenness of the fiber mesh of the fabric, thereby improving the fixation of the transferred printing layer to the fabric, which is advantageous. The pressure is not particularly limited as long as the printing layer can be transferred, and is, for example, 100 g/ ^cm2 or higher and 10,000 g/ ^cm2 or lower, and preferably 200 g/ ^cm2 or higher and 5,000 g/cm2 or ^lower . The pressure application time is not particularly limited as long as the printing layer can be transferred, and is, for example, 3 seconds to 5 minutes, and preferably 5 seconds to 1 minute.

(Step of applying adhesive resin)
The method for producing the printed matter of the present invention may, and preferably, include a step of applying an adhesive resin to the printing surface of the transfer film before the thermal transfer step.
This process applies the adhesive resin only to the printed area of the transfer film, and then the adhesive resin melts through thermal transfer, bonding the fabric and the printed surface together, thereby making the fixation of the printed surface stronger.

(Adhesive resin)
The adhesive resin is not particularly limited and may be any known resin, such as one containing polyester polyurethane as the main component. The adhesive resin may also contain additives such as wax.
Also, various commercially available products sold under the names of hot melt powder, hot melt binder, heat powder, transfer powder, DTF heat powder, DTF powder, etc. can be used. In addition to white adhesive resins, black colored adhesive resins can also be used.

The adhesive resin may be liquid or powder, but is preferably powder (powder). When the adhesive resin is powder, by applying the adhesive resin, the inkjet printing ink does not need to be dried sufficiently on the film substrate; the adhesive resin adheres only to the printed surface. This allows only the necessary amount of adhesive resin to be used, and reduces the energy and process required to dry the inkjet printing ink.

There are no particular limitations on the method for applying the adhesive resin, and any known application method can be used. For small-volume sheet-fed printing, adhesive resin powder can be sprinkled manually on each print. For large-volume roll-to-roll printing, it is also preferable to use a commercially available DTF shaker (adhesive resin applicator).

The method for producing printed matter of the present invention may include other processes. Examples of such other processes include, but are not limited to, a pre-treatment process, a post-treatment process, and a drying process.

(Push-in depth)
The ink-jet textile printing ink of the present invention is applied to a polyethylene terephthalate plate and dried to form a 15 μm-thick coating film, the difference in indentation depth between at 100° C. and at 30° C. being less than 250 nm.
Here, the indentation depth refers to the value measured using an ultra-microindentation hardness tester ENT-5 (manufactured by Elionix) to determine the depth to which a test indenter is indented when a constant load is applied. Specifically, it refers to the indentation depth (unit: nm) measured under the following conditions. The deeper the indentation depth, the softer the coating film.

Measuring device: Cho Micro Indentation Hardness Tester ENT-5 (manufactured by Elionix)
Sample: Prepared by applying inkjet printing ink to a polyethylene terephthalate plate by spin coating to a film thickness of 15 μm and drying for 15 minutes in an oven at 130° C. Measurements are made after adjusting the temperature to 30° C. and 100° C.

In the ink-jet printing ink of the present invention, when the indentation depth at 30° C. is L (nm) and the indentation depth at 100° C. is H (nm), the difference in indentation depth, H−L, is less than 250 nm.
A value of the difference in indentation depth (H - L) of less than 250 nm means that there is no significant difference between the indentation depth at 100°C and the indentation depth at 30°C. When such ink is heated by thermal transfer or the like, even if the fabric fibers are floating or protruding, the ink film does not become softer than the fabric fibers upon heating, and the ink film is not broken or locally thinned by the fibers. Therefore, even when the coating film on the fabric is stretched, it is less likely to crack.

For the ink of the present invention, the difference in indentation depth (H - L) is less than 250 nm, preferably less than 200 nm, more preferably less than 180 nm, and even more preferably less than 100 nm. When the difference in indentation depth (H - L) is within this range, the ink coating on the fabric is less likely to crack due to stretching, the coating thickness is uniform, and the color density (whiteness in the case of white ink) is improved.

(Textile prints)
The textile print of the present invention is a print in which the ink of the present invention is printed on a fabric, and more specifically, a textile print in which an ink for inkjet textile printing containing a pigment and a binder resin is printed on a fabric, wherein the binder resin is a polyether-based urethane resin, and the ink is an ink in which, when applied to a polyethylene terephthalate plate and dried, the difference in indentation depth between at 100°C and at 30°C is less than 250 nm in a coating film having a thickness of 15 μm.
The printed textile product is particularly suitable for use as a printed textile product on T-shirts, etc., because the ink conforms to the fabric even when the fabric is stretched and the product is less likely to crack. The printed textile product can also be used for other printed textile products, such as clothing, leather, decorative items, scarves, wrapping cloths, saris, curtains, bedding, tablecloths, embroidery thread, stuffed toys, novelty goods, flags, banners, etc., and in order to achieve the effects of the present invention, a printed textile product printed on a substrate that is particularly easy to stretch is preferred.

The present invention will be explained in detail below using examples, but the present invention is not limited to these examples.

(Preparation of binder resin)
<Production of Binder Resin 1>
In a nitrogen-purged vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 1,000 parts by weight of polytetramethylene ether glycol (number average molecular weight 3,000), 314 parts by weight of dicyclohexylmethane diisocyanate, and then 0.1 parts by weight of stannous octoate were added and reacted at 100°C for 1 hour. After that, 597 parts by weight of methyl ethyl ketone was added, 67 parts by weight of 2,2-dimethylolpropionic acid, and 13 parts by weight of 2,2-dimethyl-1,3-propanediol were added, and the mixture was reacted at 80°C for 3 hours. After that, 332 parts by weight of methyl ethyl ketone was added to obtain a methyl ethyl ketone solution of a urethane prepolymer having an isocyanate group at the molecular end. 55 parts by weight of triethylamine was added to the methyl ethyl ketone solution of the urethane prepolymer obtained above to neutralize the carboxyl groups in the urethane prepolymer, and then 3,664 parts by weight of water was added. Next, 13 parts by weight of an 80% by weight aqueous hydrazine solution was added and the mixture was allowed to react. After the reaction was completed, methyl ethyl ketone was removed under reduced pressure at a temperature of 40°C to 60°C, and water was added to adjust the concentration, thereby obtaining Binder Resin 1, which contained a polyether-based urethane resin having a weight-average molecular weight of 270,000, an acid value of 20 mgKOH/g, a nonvolatile content of 35 mass%, and a glass transition temperature of -82°C, in which the urethane resin was dispersed in an aqueous medium. The flow initiation temperature of Binder Resin 1 was 183°C.

<Production of Binder Resin 2>
In a nitrogen-substituted vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 1,000 parts by weight of polytetramethylene ether glycol (number average molecular weight 2000) and 412 parts by weight of methyl ethyl ketone were added and stirred uniformly, followed by the addition of 141 parts by weight of dicyclohexylmethane diisocyanate and 0.1 parts by weight of stannous octoate, and the reaction was continued for approximately 3 hours at 70° C. Next, 141 parts by weight of dicyclohexylmethane diisocyanate was added and stirred uniformly, followed by the addition of 100 parts by weight of polyethylene glycol (number average molecular weight 1000), 100 parts by weight of polytetramethylene ether glycol (number average molecular weight 1000), 44 parts by weight of 2,2-dimethylolpropionic acid, 294 parts by weight of methyl ethyl ketone, and 0.1 parts by weight of stannous octoate, and the reaction was continued for approximately 4 hours at 70° C. to obtain a methyl ethyl ketone solution of a urethane prepolymer having isocyanate groups at the molecular terminals. Next, after dilution with 392 parts by weight of methyl ethyl ketone, 35 parts by weight of triethylamine was added to the methyl ethyl ketone solution of the urethane prepolymer obtained by the above method to neutralize the carboxyl groups in the urethane prepolymer. Then, 4,481 parts by weight of ion-exchanged water was added, followed by 87 parts by weight of isophorone diamine, and the mixture was allowed to react. After completion of the reaction, the methyl ethyl ketone was removed under reduced pressure at a temperature of 40°C to 60°C, and water was added to adjust the concentration, thereby obtaining Binder Resin 2, which contained the urethane resin dispersed in an aqueous medium, a polyether-based urethane resin with a weight-average molecular weight of 50,000, an acid value of 11 mgKOH/g, and a glass transition temperature of -77°C, with a nonvolatile content of 35% by weight. The flow initiation temperature of Binder Resin 2 was 185°C.

<Binder Resin 3>
As the binder resin 3, Neorez R-967 (manufactured by DSM), which is a polyether-based urethane resin, was used.

<Production of Binder Resin 4>
In a nitrogen-substituted vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 500 parts by weight of polycarbonate polyol (number average molecular weight 2000) obtained by reacting 1,6-hexanediol with methyl carbonate, 500 parts by weight of polytetramethylene ether glycol (number average molecular weight 2000), 90 parts by weight of 2,2-dimethylolpropionic acid, and 643 parts by weight of methyl ethyl ketone were added, followed by 411 parts by weight of dicyclohexylmethane diisocyanate and then 0.1 parts by weight of stannous octoate, and the mixture was allowed to react at 80°C for 3 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having an isocyanate group at the molecular end. The mixture was then diluted with 584 parts by weight of methyl ethyl ketone, and 81 parts by weight of triethylamine was added to the methyl ethyl ketone solution of the urethane prepolymer obtained above to neutralize the carboxyl groups in the urethane prepolymer, followed by the addition of 3831 parts by weight of water. Next, 22 parts by mass of an 80% by mass aqueous solution of hydrazine was added and reacted. After completion of the reaction, methyl ethyl ketone was removed under reduced pressure at a temperature of 40°C to 60°C, and water was added to adjust the concentration, thereby obtaining Binder Resin 4, which contains the urethane resin dispersed in an aqueous medium, a polycarbonate polyether urethane resin with a nonvolatile content of 35% by mass, a weight average molecular weight of 334,000, an acid value of 25 mgKOH/g, and a glass transition temperature of -23°C. The flow initiation temperature of Binder Resin 4 was 147°C.

<Production of Binder Resin 5>
In a nitrogen-substituted vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 1,000 parts by weight of a polycarbonate polyol (number average molecular weight 2000) obtained by reacting 1,6-hexanediol with methyl carbonate, 50 parts by weight of dimethylolpropionic acid, and 730 parts by weight of methyl ethyl ketone were added and mixed uniformly. After that, 306 parts by weight of dicyclohexylmethane diisocyanate was added, followed by 0.1 parts by weight of stannous octoate, and the mixture was allowed to react at 70°C for about 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having isocyanate groups at the molecular terminals. Next, 39 parts by weight of triethylamine was added to the methyl ethyl ketone solution of the urethane prepolymer obtained by the above method to neutralize the carboxyl groups in the urethane prepolymer. After that, 3993 parts by weight of ion-exchanged water was added, followed by 45 parts by weight of isophorone diamine, and the mixture was allowed to react. After the reaction was completed, methyl ethyl ketone was removed under reduced pressure at a temperature of 40°C to 60°C, and water was added to adjust the concentration, thereby obtaining Binder Resin 5, which contained a polycarbonate-based urethane resin having a weight-average molecular weight of 330,000, an acid value of 15 mgKOH/g, a glass transition temperature of -20°C, and a nonvolatile content of 35% by mass, in which the urethane resin was dispersed in an aqueous medium. The flow initiation temperature of Binder Resin 5 was 152°C.

<Production of Binder Resin 6>
In a nitrogen-purged vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 1,000 parts by weight of polycarbonate polyol (number average molecular weight 2,000) obtained by reacting 1,6-hexanediol with methyl carbonate, 78 parts by weight of 2,2-dimethylolpropionic acid, and 600 parts by weight of methyl ethyl ketone were added, followed by the addition of 0.1 parts by weight of stannous octoate. The mixture was reacted at 80°C for 3 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having an isocyanate group at the molecular end. 62 parts by weight of triethylamine was added to the methyl ethyl ketone solution of the urethane prepolymer obtained above to neutralize the carboxyl groups in the urethane prepolymer, followed by the addition of 3,332 parts by weight of water. Next, 21 parts by weight of an 80% by weight aqueous hydrazine solution was added and the mixture was allowed to react. After the reaction was completed, methyl ethyl ketone was removed under reduced pressure at a temperature of 40°C to 60°C, and water was added to adjust the concentration, thereby obtaining Binder Resin 6, which contained a polycarbonate-based urethane resin having a weight-average molecular weight of 75,000, an acid value of 23 mgKOH/g, a glass transition temperature of -37°C, and a nonvolatile content of 35% by mass, in which the urethane resin was dispersed in an aqueous medium. The flow initiation temperature of Binder Resin 6 was 100°C.

<Production of Binder Resin 7>
In a nitrogen-purged vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 1,000 parts by weight of polycarbonate polyol (number average molecular weight 2,000) obtained by reacting 1,6-hexanediol with methyl carbonate, 94 parts by weight of 2,2-dimethylolpropionic acid, and 650 parts by weight of methyl ethyl ketone were added, followed by the addition of 0.1 parts by weight of stannous octoate. The mixture was reacted at 80°C for 3 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having an isocyanate group at the molecular end. 74 parts by weight of triethylamine was added to the methyl ethyl ketone solution of the urethane prepolymer obtained above to neutralize the carboxyl groups in the urethane prepolymer, followed by the addition of 3,610 parts by weight of water. Next, 23 parts by weight of an 80% aqueous hydrazine solution was added and the mixture was allowed to react. After the reaction was completed, methyl ethyl ketone was removed under reduced pressure at a temperature of 40°C to 60°C, and water was added to adjust the concentration, thereby obtaining Binder Resin 7, which contained a polycarbonate-based urethane resin having a weight-average molecular weight of 202,000, an acid value of 26 mgKOH/g, a glass transition temperature of -27°C, and a nonvolatile content of 35% by mass, in which the urethane resin was dispersed in an aqueous medium. The flow initiation temperature of Binder Resin 7 was 164°C.

<Binder resin 8>
Hydran HW-311 (manufactured by DIC Corporation), an aromatic polyester urethane resin, was used as the binder resin 8. The binder resin 8 had a glass transition temperature of -31°C and a flow initiation temperature of 95°C.

<Binder Resin 9>
As the binder resin 9, Neorez R-600 (manufactured by DSM), which is a polyether-based urethane resin, was used.

<Binder Resin 10>
As the binder resin 10, M-141 (manufactured by Seiko PMC Corporation), an acrylic resin, was used.

(Production Example 1: Production of aqueous pigment dispersion (A1))
45 parts by mass of Ti-Pure TS-6300 (manufactured by Chemours) as a pigment, 4.5 parts by mass of Solsperse 43000 Aqueous Dispersant (manufactured by Lubrizol) as a dispersing resin, and 50.5 parts by mass of ion-exchanged water were mixed and, while stirring, circulated for 30 minutes at a rotor peripheral speed of 12.5 m/s and a flow rate of 10 g/s in a 0.6 L-nanomill into which Φ=0.5 mm zirconia beads were introduced at a filling rate of 90%.
Next, the dispersion was recovered, diluted with ion-exchanged water to a pigment concentration of 40%, and mixed to obtain an aqueous pigment dispersion (A1).

(Production Example 2: Synthesis of Polymer E)
A hexane solution of BuLi and a styrene solution in which styrene had been dissolved in tetrahydrofuran in advance were introduced into a T-shaped micromixer M1 from the tube reactors P1 and P2 shown in FIG. 1, and living anionic polymerization was carried out to obtain a polymer.

Next, the polymer obtained in the above process was transferred to the T-shaped micromixer M2 through the tube reactor R1 shown in Figure 1, and the growing end of the polymer was trapped using a reaction adjuster (α-methylstyrene (α-MeSt)) introduced from the tube reactor P3.

Next, a tert-butyl methacrylate solution, prepared by dissolving tert-butyl methacrylate in tetrahydrofuran, was introduced from the tube reactor P4 shown in Figure 1 into the T-shaped micromixer M3, and a continuous living anionic polymerization reaction was carried out with the trapped polymer transported through the tube reactor R2. The living anionic polymerization reaction was then quenched by supplying methanol to produce a block copolymer (PA-1) composition.

When producing the block copolymer (PA-1) composition, the reaction temperature was set to 24°C by immersing the entire microreactor shown in Figure 1 in a constant temperature bath.

The molar ratio of the monomers constituting the block copolymer (PA-1) obtained by the above method was (BuLi/styrene/α-methylstyrene/tert-butyl methacrylate) = 1.0/12.0/1.3/8.1.

The resulting block copolymer (PA-1) composition was hydrolyzed by treatment with a cation exchange resin, then distilled under reduced pressure. The resulting solid was pulverized to obtain Polymer E, a powdered dispersing aid with a weight-average molecular weight of 2,710 and an acid value of 145. The powdered Polymer (E) was 100% neutralized with KOH and used as an aqueous solution with a resin solids content of 15%.

The various physical properties of the resulting dispersing aid, Polymer E, and each of the binder resins produced were measured as follows.

(Method for measuring weight average molecular weight (Mw))
Measurement was carried out by gel permeation chromatography (GPC) under the following conditions.

Measurement device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.

"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D. x 30cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (sample concentration 0.4% by mass in THF solution)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(standard polystyrene)
"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
Tosoh Corporation's "TSKgel Standard Polystyrene A-2500"
Tosoh Corporation's "TSKgel Standard Polystyrene A-5000"
"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation
Tosoh Corporation's "TSKgel Standard Polystyrene F-550"

(Method for measuring acid value)
Measurement was performed in accordance with JIS test method K 0070-1992. 0.5 g of a sample was dissolved in THF, and titration was performed with 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

(Method for measuring flow starting temperature)
Each of the obtained binder resins was applied to release paper (coating thickness: 150 μm) and dried in a hot air dryer at 70° C. for 2 minutes, and then at 120° C. for 2 minutes to obtain a dried product. The flow initiation temperature of this dried product was measured using a flow tester "CFT-500A" manufactured by Shimadzu Corporation (using a die with an opening diameter of 1 mm and a length of 1 mm, a load of 98 N, and a temperature rise rate of 3° C./min).

(Method for measuring glass transition temperature)
The glass transition temperature was obtained by measuring each binder resin from which the dispersion medium had been completely removed using a differential scanning calorimeter (DSC) in accordance with JIS K 7121.

Example 1
An aqueous ink of Example 1 was obtained by mixing 35 parts by mass of the aqueous pigment dispersion (A1), 40.0 parts by mass of binder resin 1 (non-volatile content 35% by mass), 0.4 parts by mass of Surfynol 440 (manufactured by EVONIK, an acetylene-based surfactant), 0.2 parts by mass of Surfynol 104PG50 (manufactured by EVONIK, an acetylene-based surfactant), 2 parts by mass of glycerin, 10 parts by mass of ethylene glycol, 0.05 parts by mass of ACTICIDE B-20 (manufactured by Thor Japan Co., Ltd.) as a preservative, 1.7 parts by mass of a 15% by mass aqueous solution of polymer E (100% neutralized with KOH), and the remainder being ion-exchanged water.

Example 2
A water-based ink of Example 2 was obtained in the same manner as in Example 1, except that the binder resin of the ink was changed to the binder resin shown in Table 1.

(Comparative Examples 1 to 8)
Water-based inks of Comparative Examples 1 to 8 were obtained in the same manner as in Example 1, except that the binder resin of the ink was changed to the binder resin shown in Tables 2 and 3.

(Preparation of ink coating film for indentation depth measurement)
The aqueous inks of Examples 1 and 2 and Comparative Examples 1 to 8 were spin-coated onto a polyester film substrate (Lumirror, manufactured by Toray Industries, Inc.), and then dried with hot air at 130° C. for 15 minutes to obtain a white ink coating film of approximately 15 μm.

(Measurement of indentation depth)
The ink coating film obtained by the above method was measured for indentation depth when a test indenter was pressed into the ink coating film at 100°C or 30°C with a load end load of 100 μN (load division number: 500, load step interval: 20 ms, load time: 10,000 ms) using an ultra-microindentation hardness tester ENT-5 (manufactured by Elionix). The maximum indentation depth at 100°C was defined as H (nm), and the maximum indentation depth at 30°C was defined as L (nm). The difference in indentation depth H - L was calculated and evaluated according to the following criteria. The evaluation results are shown in Tables 1 to 3.
◯: The difference in indentation depth H−L is less than 250 nm. △: The difference in indentation depth H−L is 250 nm or more and less than 500 nm. ×: The difference in indentation depth H−L is 500 nm or more and less than 800 nm. XX: The difference in indentation depth H−L is 800 nm or more.

(Evaluation of circulation filtration characteristics (resistance of clogging of the filter installed in the ink circulation path))
The circulation filtration characteristics were evaluated by circulating 200 g of the aqueous inks obtained in the examples and comparative examples in a circulation device having a circulation path equipped with a 12 μm pore size SUS mesh filter (manufactured by Manabe Kogyo Co., Ltd.) The flow rate of the aqueous ink immediately after the start of circulation was adjusted to 50 g/min.

The flow rate of the aqueous ink was measured every hour from the start of the circulation, and the time elapsed until the flow rate became 25 g/min or less was recorded, and the circulation filtering property was evaluated based on the following evaluation criteria.
◯: 120 hours or more from the start of circulation ×: Less than 120 hours from the start of circulation

(Production of printed matter)
The aqueous inks obtained in the examples were solid-printed onto a substrate film (Godora DTF transfer film-8.3 x 11.7) using an inkjet head manufactured by Seiko Epson Corporation so that the film thickness after transfer was 15 μm, and the film was left to stand for 30 minutes to obtain a transfer film. Subsequently, adhesive resin powder (DTF hot melt powder manufactured by Europort Co., Ltd.) was adsorbed onto the ink-coated surface, followed by hot air drying at 160°C for 3 minutes to adhere the adhesive resin powder. Finally, the adhesive resin powder surface was heat-pressed against black cotton knit at 140°C for 5 seconds to obtain textile prints of Examples 1 and 2 and Comparative Examples 1 to 8.

(Evaluation of Whiteness)
The ink density (OD value) of the textile print obtained by the above method was measured using an X-Rite (spectrodensitometer/colorimeter manufactured by X-Rite Inc.) to evaluate the ink density on the fabric. The evaluation results are shown in Tables 1 to 3.
◯: L*≧92.0
Δ: 90.0≦L*<92.0
×: L*<90.0

(Evaluation of elongation cracks)
The image area of the textile print obtained by the above method was held at both ends and stretched by 150% for 1 second. This was repeated, and the number of times the ink coating film cracked was visually judged and scored. The evaluation results are shown in Tables 1 to 3.
5: The coating film does not crack even when the ink-printed portion is stretched 10 times or more, and the whiteness is maintained.
4: The coating cracks when the ink-printed portion is stretched 7 to 10 times.
3: The coating cracks when the ink-printed area is stretched 4 to 6 times.
2: The coating cracks when the ink-printed area is stretched two or three times.
1: The coating film cracks when the ink-printed portion is stretched just once.

The product names and manufacturer names in Tables 1 to 3 are as follows: The binder resin contents in Tables 1 to 3 are values of solid content.
Surfynol 440: acetylene-based surfactant (manufactured by EVONIK)
Surfynol 104PG50: acetylene-based surfactant (manufactured by EVONIK)
・ACTICIDE B-20: Preservative (manufactured by Thor Japan Co., Ltd.)

The inks of Examples 1 and 2 of the present invention produced printed matter with high whiteness, did not cause cracks or breaks in the image when stretched, and did not clog the ink passages even when circulated for a long period of time.
On the other hand, in Comparative Examples 1 to 8, in which the difference in indentation depth was outside the range of the present invention, stretching cracks occurred when the fabric was stretched.

1: T-shaped micro mixer M1
2: T-shaped micro mixer M2
3: T-shaped micro mixer M3
4: Tube reactor R1
5: Tube reactor R2
6: Tube reactor R3
7: Tube reactor P1 for pre-cooling
8: Tube reactor P2 for pre-cooling
9: Tube reactor P3 for pre-cooling
10: Tube reactor P4 for pre-cooling

Claims (9)

An inkjet printing ink containing a pigment, a binder resin, and a surfactant ,
the content of the pigment is in the range of 1 to 20% by mass relative to the total amount of the inkjet textile printing ink,
the pigment is alumina-treated titanium oxide,
the binder resin contains a polyether-based urethane resin,
The weight average molecular weight of the polyether-based urethane resin is in the range of 40,000 to 400,000,
The flow starting temperature of the polyether-based urethane resin is 170°C or higher,
The acid value of the polyether-based urethane resin is 5 to 40 mgKOH/g,
The inkjet printing ink , wherein the surfactant comprises an acetylene-based surfactant . 2. The ink-jet textile printing ink according to claim 1, wherein the ink-jet textile printing ink is applied to a polyethylene terephthalate plate and dried to form a coating film having a thickness of 15 μm, and the difference in indentation depth between the ink-jet textile printing ink at 100°C and the ink-jet textile printing ink at 30°C is less than 250 nm. 3. The ink-jet printing ink according to claim 1, wherein the polyether-based urethane resin has a glass transition temperature (Tg) of -95 to -0°C. 3. The inkjet textile printing ink according to claim 1, wherein the content of the polyether-based urethane resin in the total amount of the inkjet textile printing ink is in the range of 1 to 22% by mass. 3. The ink-jet printing ink according to claim 1, wherein the polyether urethane resin has a flow-initiation temperature of 170 to 195°C. 3. The inkjet textile printing ink according to claim 1, wherein the content of the surfactant is in the range of 0.001 to 2% by mass based on the total amount of the inkjet textile printing ink. a step of printing the inkjet textile printing ink according to claim 1 or 2 onto a film substrate to obtain a transfer film;
A method for producing a printed matter, comprising the steps of overlapping the transfer surface of a fabric and the printing surface of the transfer film, and performing thermal transfer. The method for producing a printed matter according to claim 7 , further comprising the step of applying an adhesive resin to the printing surface of the transfer film. A textile print in which the inkjet textile printing ink according to claim 1 or 2 is printed on fabric.