Inkjet printing ink and inkjet recording method

Abstract

The problem to be solved by the present invention is to provide an ink for ink jet textile printing, which does not cause a crack or a fracture of an image when a printed matter is stretched, and which does not block a path even when the ink is circulated by a circulation type ink jet head.　The present invention solves the above problem by an ink jet textile printing ink comprising a pigment and a binder resin, wherein the binder resin includes a polyether-based urethane resin; the difference between the indentation depth at 100°C and the indentation depth at 30°C of a coating film that has a thickness of 15 μm and is obtained by applying the ink onto a polyethylene terephthalate sheet and drying same is less than 250 nm.

Description

[Technical Field]

[0001] The present invention relates to an inkjet textile printing ink and an inkjet recording method. [Background technology]

[0002] 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.

[0003] 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.

[0004] One inkjet printing method 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 increasing the amount of ink applied to form a highly colored image, which can damage the texture of the fabric. In contrast, DTF (direct-to-film) printing, which uses a transfer film to thermally transfer an image onto fabric, is gaining attention as a simpler method that can achieve high color development.

[0005] For example, Patent Document 1 discloses a technique in which a transfer film is produced 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. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-21342 Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above, an object of the present invention is to provide an inkjet textile 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-type inkjet head. [Means for solving the problem]

[0008] 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.

[0009] 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 is such that when the ink is applied to a polyethylene terephthalate plate and dried, a coating film having a thickness of 15 μm has a difference in indentation depth between that at 100°C and that at 30°C of less than 250 nm.

[0010] Item 2. The inkjet printing ink according to Item 1, wherein the pigment is a white pigment.

[0011] Item 3. The inkjet printing ink according to Item 2, wherein the white pigment is alumina-treated titanium oxide.

[0012] 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.

[0013] Item 5. The method for producing a printed matter according to Item 4, further comprising the step of applying an adhesive resin to the printed surface of the transfer film.

[0014] 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, A textile print, wherein 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 and dried on a polyethylene terephthalate plate is less than 250 nm. [Effects of the Invention]

[0015] The present invention can provide an inkjet textile 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 ink passage when circulated.

[0016] Furthermore, the present invention can 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 ink path when circulated. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram of a microreactor used in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] 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.

[0019] (binder resin) The binder resin used in the inkjet textile printing ink of the present invention is a polyether-based urethane resin.

[0020] (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 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 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.

[0021] As the polyether-based urethane resin, it is preferable to use a polyurethane having a hydrophilic group in order to improve the aqueous dispersion stability in the inkjet textile printing ink of the present invention.

[0022] The hydrophilic group may be generally called an anionic group, a cationic group, or a nonionic group. Among these, it is preferable to use an anionic group or a cationic group as the hydrophilic group.

[0023] As the anionic group, for example, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, etc. can be used. Among these, it is preferable to use a carboxylate group or a sulfonate group that has been partially or completely neutralized with a basic compound or the like in order to maintain good aqueous dispersion stability.

[0024] Examples of basic compounds that can be used to neutralize the carboxyl group or sulfonic acid group as the anionic group include organic amines such as ammonia, triethylamine, pyridine, and morpholine, alkanolamines such as monoethanolamine, and metal base compounds containing Na, K, Li, Ca, etc. Among these, the organic amines are preferably used as the basic compound in order to prevent problems with the washing fastness of the printed image caused by the basic compound remaining in the printed image (i.e., dried film) formed with the inkjet textile printing ink of the present invention, and it is more preferable to use an organic amine with a boiling point of 100°C or less, such as ammonia or triethylamine.

[0025] 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.

[0026] The nonionic group may be, for example, a polyoxyalkylene group such as a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly(oxyethylene-oxypropylene) group, or a polyoxyethylene-polyoxypropylene group. Of these, it is preferable to use a polyoxyalkylene group having an oxyethylene unit as the nonionic group in order to further improve hydrophilicity.

[0027] The polyether-based urethane resin used preferably has 0.5% by mass to 30% by mass of the hydrophilic group relative to the total amount of the polyether-based urethane resin, and more preferably has 1% by mass to 20% by mass in order to obtain an ink with even better aqueous dispersion stability.

[0028] As the polyether-based urethane resin, a reaction product of a polyol containing a polyether polyol and a polyol having a hydrophilic group and a polyisocyanate can be used.

[0029] Examples of the polyether polyol include compounds having two or more active hydrogen groups, such as 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, which are subjected to addition polymerization of cyclic ether compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclophenylene; and compounds obtained by ring-opening polymerization of the cyclic ether compounds 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.

[0030] The polyol having a hydrophilic group may 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 a polyol obtained by reacting a compound having two epoxy groups with a secondary amine.

[0031] As the polyol having a hydrophilic group, one having an anionic group can be used, and for example, 1,2-bis(hydroxymethyl)propionic acid, 1,2-bis(hydroxymethyl)butanoic acid, etc. can be used.

[0032] As the polyol having a hydrophilic group, one having a nonionic group can be used, and for example, polyethylene glycol or polypropylene glycol having a structural unit derived from ethylene oxide can be used.

[0033] In addition to the above-mentioned polyols, other polyols may be used as needed in the production of the polyether-based urethane resin.

[0034] Examples of the polyisocyanate that reacts with the polyol containing the polyether polyol include 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. These may be used alone or in combination of two or more.

[0035] 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 matter. Dicyclohexylmethane diisocyanate is particularly preferable, as it suppresses cracking during stretching of the coating film and also has a favorable effect on circulation and filterability.

[0036] When a chain extender is used in producing the polyether-based urethane resin, examples of the chain extender 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, N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, 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-semicarbazidopropionic hydrazide, 3-semicarbazidopropyl-carbazate, and semicarbazido-3-semicarbazidomethyl-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 be used to 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.

[0037] The chain extender can be used during or after the reaction of the polyol with the polyisocyanate.

[0038] The polyether-based urethane resin is preferably used in the range of 1% by mass to 22% by mass relative to the total amount of the inkjet textile printing ink of the present invention, and more preferably in the range of 8% by mass to 15% by mass in order to prevent clogging over time of a filter provided midway through the ink circulation path.

[0039] The viscosity of the polyether urethane resin as an aqueous dispersion with a nonvolatile 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 improves the flexibility of ink formulation.

[0040] 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).

[0041] The flow initiation temperature of the polyether-based urethane resin is preferably 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 initiation temperature can be measured for 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).

[0042] The 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. When the acid value is within this range, the ink dispersion stability is improved and clogging over time of a filter installed in the ink circulation path is easily suppressed.

[0043] The polyether-based urethane resin preferably has a weight-average molecular weight in the range of 10,000 to 400,000, and more preferably in the range of 40,000 to 300,000, in order to prevent clogging over time of a filter installed in the ink circulation path.

[0044] The polyether-based urethane resin is dispersed in the aqueous medium as particles, and the particle diameter is preferably 70 μm or more, more preferably 75 μm or more, but is not limited thereto. The particle diameter of the polyether-based urethane resin is the cumulative 50% diameter (D50) value measured by dynamic light scattering.

[0045] Furthermore, the ink-jet textile printing ink of the present invention may contain a crosslinking agent, which will be described later, for the purpose of further improving abrasion resistance, such as washing fastness, etc. When the crosslinking agent is used, it is preferable to use the polyether-based urethane resin having a functional group capable of undergoing a crosslinking reaction with the functional group of the crosslinking agent.

[0046] However, since it cannot be denied that an ink containing a crosslinking agent may undergo crosslinking within the circulation path of the ink circulation type inkjet head, it is preferable to use an ink that does not contain the crosslinking agent in order to prevent clogging of a filter provided within the circulation path, etc.

[0047] (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.

[0048] The polycarbonate-based urethane resin may be a reaction product of a polyol containing a polycarbonate polyol with a polyisocyanate. Alternatively, the polycarbonate-based urethane resin may be a reaction product of a polyol containing a polycarbonate polyol with a hydrophilic group and a polyisocyanate. When a polyurethane containing a urea bond is used as the polycarbonate-based urethane resin, a reaction product of a polyol containing a polycarbonate polyol with a polyisocyanate and a chain extender such as a polyamine may be used.

[0049] As the polycarbonate polyol, for example, a reaction product of a carbonate ester and a low molecular weight polyol, preferably a linear aliphatic diol, can be used.

[0050] As the carbonate ester, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate, etc. can be used.

[0051] 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 with relatively low molecular weights 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.

[0052] As the polyisocyanate, the same polyisocyanates having a hydrophilic group that can be used for the polyether-based urethane resin can be used.

[0053] As the polyol having a hydrophilic group, the same polyol having a hydrophilic group that can be used for the polyether-based urethane resin can be used.

[0054] 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; hydrazine, triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic dihydrazide, adipic dihydrazide, glutaric dihydrazide, sebacic dihydrazide, isophthalic dihydrazide; β-semicarbazidopropionic hydrazide, 3-semicarbazidopropyl-carbazic acid ester, semicarbazido-3-semicarbazidomethyl-3,5,5-trimethylcyclohexane, 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.

[0055] The polyamine is preferably used in such a range that the equivalent weight of the amino group of the polyamine is 0.01 to 1.0 (equivalent ratio) relative to the equivalent weight of the isocyanate group of the urethane prepolymer, which is the reaction product of the polyol and polyisocyanate, more preferably 0.01 to 0.5 (equivalent ratio), and even more preferably 0.01 to 0.3 (equivalent ratio).

[0056] The polyester-based urethane resin may be a reaction product of a polyol, including a polyester polyol, with a polyisocyanate. Examples of the polyester polyol include a reaction product of a diol with a dicarboxylic acid, a product obtained by dehydration condensation of a hydroxycarboxylic acid alone or in combination with a diol or a dicarboxylic acid, and a ring-opening polymerization product of a cyclic ester compound such as ε-caprolactone.

[0057] 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.

[0058] 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.

[0059] Examples of the hydroxycarboxylic acid include p-hydroxybenzoic acid and p-(2-hydroxyethoxy)benzoic acid.

[0060] Furthermore, as the other polyol, in addition to the above, 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 can be used alone or in combination of two or more.

[0061] The acrylic resin is not particularly limited, and may be a homopolymer or copolymer of (meth)acrylate, or a copolymer of (meth)acrylate and another vinyl monomer.

[0062] (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.

[0063] The pigment may be either a non-acid-treated pigment or an acid-treated pigment, and may be in either a dry powder or wet cake form.

[0064] Examples of the inorganic pigment that can be used include iron oxide, titanium oxide, and carbon black produced by a contact method, a furnace method, a thermal method, or the like.

[0065] Examples of the organic pigment that can be used include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments), polycyclic pigments (such as phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments), lake pigments (such as basic dye-type chelates and acid dye-type chelates), nitro pigments, nitroso pigments, and aniline black.

[0066] Specific examples of the pigments used in black ink include No. 2300, No. 2200B, No. 900, No. 980, No. 960, No. 950, No. 33, No. 40, No. 45, No. 45L, No. 52, HCF88, MCF88, MA7, MA8, MA100, etc. manufactured by Mitsubishi Chemical Corporation; Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. manufactured by Columbia Chemical; 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 Cabot Corporation; and Color 1000R manufactured by Degussa. Carbon blacks that can be used include Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, V, 1400U, Special Black 6, 5, 4, 4A, NIPEX150, NIPEX160, NIPEX170, and NIPEX180.

[0067] Specific examples of pigments used in yellow inks include CI 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.

[0068] Specific examples of pigments used in magenta inks include CI Pigment Violet 19, CI 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.

[0069] Specific examples of pigments used in cyan inks include CI Pigment Blue 1, 2, 3, 15, 15:3, 15:4, 15:6, 16, 22, 60, 63, 66, and the like.

[0070] Specific examples of pigments used in the red ink include one or more selected from the group consisting of CI Pigment Red 17, 49:2, 112, 149, 150, 177, 178, 179, 188, 254, 255, and 264.

[0071] Specific examples of pigments used in orange inks include CI Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63, 64, 71, 73, and 81.

[0072] Specific examples of pigments used in green ink include CI Pigment Green 7, 10, 36, 58, and 59.

[0073] Specific examples of pigments used in violet inks include CI Pigment Violet 19, 23, 32, 33, 36, 38, 43, and 50.

[0074] Furthermore, 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 the white ink include alkaline earth metal sulfates, carbonates, finely powdered silicic acid, synthetic silicates, and other silicas, calcium silicate, alumina, alumina hydrate, titanium oxide, zinc oxide, talc, clay, and the like. These may be surface-treated. Among these, titanium oxide is preferred, and alumina-treated titanium oxide is more preferred.

[0075] As the pigment, the above-mentioned pigments can be used alone or in combination of two or more kinds.

[0076] In order to ensure that the pigment is present stably in the ink, it is preferable that a means be taken to disperse the pigment well in an aqueous medium such as water.

[0077] 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 of dispersing and / or dissolving 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, in an aqueous medium such as water.

[0078] The self-dispersing pigment may be, for example, a pigment that has been subjected to a physical or chemical treatment to bond (graft) a dispersibility-imparting group or an active species having a dispersibility-imparting group 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 a hypohalous acid salt, 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.

[0079] Since aqueous inks containing self-dispersing pigments do not need to contain the pigment dispersant, they are free from foaming and other problems caused by pigment dispersants, and inks with excellent ejection stability can be easily prepared. Furthermore, aqueous inks containing self-dispersing pigments are easy to handle and can contain a larger amount of pigment because a significant increase in viscosity caused by pigment dispersants is suppressed, making them suitable for producing printed materials with high print density.

[0080] Commercially available self-dispersing pigments can also be used, and examples of such commercially available products include Microjet CW-1 (trade name; manufactured by Orient Chemical Industries, Ltd.), CAB-O-JET200, and CAB-O-JET300 (all trade names; manufactured by Cabot Corporation).

[0081] The pigment is preferably used in an amount of 1% by mass to 20% by mass, more preferably 2% by mass to 15% by mass, relative to the total amount of the ink, in order to maintain excellent dispersion stability of the pigment and improve the print density and washability of the printed matter.

[0082] (pigment dispersant) The pigment dispersant has the function of dispersing the pigment.

[0083] Examples of pigment dispersants that can be used include polyvinyl alcohols, polyvinylpyrrolidones, acrylic resins such as acrylic acid-acrylate copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylate copolymers, styrene-α-methylstyrene-acrylic acid copolymers, and styrene-α-methylstyrene-acrylic acid-acrylate 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.

[0084] As the pigment dispersant, the polymer (E) described below can be used, which can significantly reduce coarse particles and, as a result, impart good ejection stability required when the ink is ejected by an inkjet method.

[0085] As the polymer (E), a polymer having an anionic group can be used. In particular, it is preferable to use a polymer having a number average molecular weight in the range of 1,000 to 6,000, which has a solubility in water of 0.1 g / 100 ml or less, and which can form fine particles in water when the neutralization rate of the anionic group with a basic compound is 100%.

[0086] The solubility of the polymer (E) in water was defined as follows: 0.5 g of polymer (E), the particle size of which had been adjusted to a range of 250 μm to 90 μm using sieves with openings of 250 μm and 90 μm, 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 a temperature of 25°C. After immersion for 24 hours, 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.

[0087]

number

[0088] 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 the 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 potassium hydroxide alcohol solution using phenolphthalein as an indicator. (2) After adding 1 g of polymer (E) to 50 ml of water, 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 liquid 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.

[0089] After leaving it for 24 hours, the liquid at a depth of 2 centimeters from the liquid surface is sampled and the presence of fine particles is confirmed by determining whether light scattering information due to the formation of fine particles can be obtained using a dynamic light scattering particle size distribution analyzer (Nikkiso Co., Ltd., dynamic light scattering particle size analyzer "Microtrac Particle Size Distribution Analyzer UPA-ST150").

[0090] 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, although 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 Particle Size Distribution Analyzer UPA-ST150, manufactured by Nikkiso Co., Ltd.), similar to the method for measuring the microparticles.

[0091] The neutralization rate of the polymer (E) was determined by the following formula.

[0092]

number

[0093] The acid value of the polymer (E) was measured in accordance with JIS test method K 0070-1992. Specifically, 0.5 g of a sample was dissolved in tetrahydrofuran, and the acid value was determined by titration with a 0.1 M alcoholic solution of potassium hydroxide using phenolphthalein as an indicator.

[0094] 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 preferably 1,500 to 4,500, in order to obtain an ink with good dispersion stability of the pigment.

[0095] The number average molecular weight is a value calculated as polystyrene measured by GPC (gel permeation chromatography), and specifically, is a value measured under the following conditions.

[0096] (Method for measuring number average molecular weight (Mn)) Measurement was performed by gel permeation chromatography (GPC) under the following conditions. Measurement equipment: High-speed GPC equipment (Tosoh Corporation "HLC-8220GPC") Column: The following columns manufactured by Tosoh Corporation were connected in series and used.

[0097] "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" (7.8mmI.D. x 30cm) x 1 Detector: RI (differential refractometer) Column temperature: 40℃ Eluent: tetrahydrofuran Flow rate: 1.0mL / min Injection volume: 100 μL (sample concentration 0.4% by mass in tetrahydrofuran solution) Standard sample: A calibration curve was prepared using the following standard polystyrene. (standard polystyrene) Tosoh Corporation's "TSKgel Standard Polystyrene A-500" Tosoh Corporation's "TSKgel Standard Polystyrene A-1000" Tosoh Corporation's "TSKgel Standard Polystyrene A-2500" Tosoh Corporation's "TSKgel Standard Polystyrene A-5000" Tosoh Corporation's "TSKgel Standard Polystyrene F-1" Tosoh Corporation's "TSKgel Standard Polystyrene F-2" Tosoh Corporation's "TSKgel Standard Polystyrene F-4" Tosoh Corporation's "TSKgel Standard Polystyrene F-10" Tosoh Corporation's "TSKgel Standard Polystyrene F-20" Tosoh Corporation's "TSKgel Standard Polystyrene F-40" Tosoh Corporation's "TSKgel Standard Polystyrene F-80" Tosoh Corporation's "TSKgel Standard Polystyrene F-128" Tosoh Corporation's "TSKgel Standard Polystyrene F-288" Tosoh Corporation's "TSKgel Standard Polystyrene F-550"

[0098] The polymer (E) 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 for a 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%.

[0099] The polymer (E) may be any polymer that is insoluble or poorly soluble in water when not neutralized and that forms fine particles when 100% neutralized, and is not particularly limited as long as it has a hydrophobic group in one molecule in addition to an anionic group, which is a hydrophilic group.

[0100] Such polymers include block polymers 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 the solubility in water 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 having the same acid value, polymers with lower molecular weights tend to have higher solubility in water, while polymers with higher molecular weights tend to have lower solubility in water. For this reason, in the present invention, polymer (E) is determined by its solubility in water.

[0101] The polymer (E) may be a homopolymer but is preferably a copolymer, and 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.

[0102] Furthermore, the polymer (E) is preferably 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.

[0103] Among these, the polymer (E) is preferably a vinyl polymer produced using a (meth)acrylate monomer as one of the raw materials, and the method for producing such a vinyl polymer is preferably living radical polymerization or living anionic polymerization, and more preferably living anionic polymerization from the viewpoint of enabling more precise design of the molecular weight of the block polymer and each segment.

[0104] The polymer (E) produced by living anionic polymerization is specifically a polymer represented by general formula (3).

[0105] [ka]

[0106] 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 of 1 to 5, and B represents an aromatic group or an alkyl group.

[0107] In general formula (3), A1 represents an organolithium initiator residue. Specific examples of the organolithium initiator include alkyllithiums such as methyllithium, ethyllithium, propyllithium, butyllithium (e.g., n-butyllithium, sec-butyllithium, iso-butyllithium, and tert-butyllithium), 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.

[0108] In organolithium initiators, the bond between the organic group and lithium is cleaved, generating an active terminal on the organic group side, from which polymerization is initiated. Therefore, an organic group derived from the organolithium is bonded to the end of the resulting polymer. In the present invention, the organic group derived from the organolithium bonded to the polymer end is referred to as an organolithium initiator residue. For example, in a polymer using methyllithium as the initiator, the acid group of the organolithium initiator is a methyl group, and in a polymer using butyllithium as the initiator, the acid group of the organolithium initiator is a butyl group.

[0109] In the general formula (3), A2 represents a polymer block having a hydrophobic group. As described above, A2 is preferably a group that is highly adsorbable 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.

[0110] Examples of the monomer having an aromatic ring include styrene-based monomers such as styrene, p-tert-butyl, styrene, 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.

[0111] Furthermore, examples of the monomer having a heterocycle include vinylpyridine-based monomers such as 2-vinylpyridine, 4-vinylpyridine, etc. These monomers can be used alone or in combination of two or more.

[0112] 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 the 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.

[0113] The method for introducing the anionic group of A3 is not particularly limited, and for example, when 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 with other monomers a (meth)acrylate having protecting groups that can be regenerated to anionic groups by deprotection, in which some or all of the protecting groups that can be regenerated to anionic groups have been regenerated to anionic groups.

[0114] The (meth)acrylic acid used in the polymer block A3 is a general term for acrylic acid and methacrylic acid, and the (meth)acrylate is a general term for acrylate and methacrylate.

[0115] Specific examples of (meth)acrylic acid and (meth)acrylate 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, n-stearyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, and 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, tetrafluoropropyl (meth)acrylate, pentafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, pentadecafluorooctyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, N,Examples of suitable (meth)acrylates include polyalkylene oxide group-containing (meth)acrylates such as 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, 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.

[0116] In living anionic polymerization, if the monomer used has a group having an active proton, such as an anionic group, the active terminal of the living anionic polymerization polymer immediately reacts with the group having an active proton and is deactivated, so a polymer cannot be obtained. Since it is difficult to polymerize a monomer having a group having an active proton as is in living anionic polymerization, it is preferable to polymerize the monomer in a state where the group having the active proton is protected, and then regenerate the group having the active proton by deprotecting the protecting group.

[0117] For these reasons, it is preferable to use a (meth)acrylate-containing monomer having a protecting group that can be regenerated into an anionic group by deprotection in the polymer block A3. The use of 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 deprotection after obtaining the block polymer.

[0118] For example, when 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 the like in a subsequent step. In this case, the protecting group convertible to a carboxyl group is preferably a group having an ester bond, and examples thereof include primary alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, and n-butoxycarbonyl groups; secondary alkoxycarbonyl groups such as isopropoxycarbonyl and sec-butoxycarbonyl groups; tertiary alkoxycarbonyl groups such as t-butoxycarbonyl groups; phenylalkoxycarbonyl groups such as benzyloxycarbonyl groups; and alkoxyalkylcarbonyl groups such as ethoxyethylcarbonyl groups.

[0119] 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 suitable (meth)acrylates include alkyl (meth)acrylates such as methyl (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 to a carboxyl group. Considering industrial availability, t-butyl (meth)acrylate is more preferred.

[0120] In the general formula (3), B represents an aromatic group or an alkyl group having 1 to 10 carbon atoms, and n represents an integer of 1 to 5.

[0121] In living anionic polymerization, when a (meth)acrylate monomer is directly polymerized 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 a (meth)acrylate monomer onto 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.

[0122] Living anionic polymerization can be carried out by adjusting the reaction conditions, either batchwise as in conventional free-radical polymerization or continuously using a microreactor. Microreactors allow for good mixing of the polymerization initiator and monomer, allowing reactions to start simultaneously and maintaining a uniform temperature and polymerization rate, thereby narrowing the molecular weight distribution of the resulting polymer. At the same time, the stable growing ends facilitate the production of 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.

[0123] 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 starts 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).

[0124] Next, the obtained first polymer is transferred to a T-shaped micromixer M2 (2 in Figure 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 Figure 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.

[0125] Next, the first polymer whose reaction has been adjusted in the T-shaped micromixer M2 is transferred to a T-shaped micromixer M3 (3 in FIG. 1), and in the mixer M3, the second monomer introduced from the tube reactor P4 and the first polymer whose reaction has been adjusted are continuously subjected to living anionic polymerization (step 3).

[0126] The reaction is then quenched with a compound having an active proton, such as methanol, to produce a block copolymer.

[0127] 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 the 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.

[0128] Thereafter, the anionic group is regenerated by a deprotection reaction such as hydrolysis, thereby obtaining the above-mentioned A3, that is, a polymer block containing an anionic group.

[0129] A method for regenerating the ester bond of the protecting group capable of regenerating to an anionic group by a deprotection reaction such as hydrolysis will be described in detail below.

[0130] The hydrolysis reaction of an ester bond proceeds under both acidic and basic conditions, but the conditions vary slightly depending on the group having an ester bond. For example, when the group having an 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.

[0131] 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.

[0132] 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 acid groups such as a carboxyl group (—COOH) or a sulfo group (—SO3H) 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 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.

[0133] Furthermore, when the group having an ester bond is a phenylalkoxycarbonyl group such as a benzyloxycarbonyl group, it can be converted to a carboxyl group by hydrogenation reduction reaction, where 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, thereby quantitatively regenerating the phenylalkoxycarbonyl group into a carboxyl group.

[0134] 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 and n-butoxycarbonyl groups. Here, under acidic conditions where t-butoxycarbonyl groups hydrolyze, n-butoxycarbonyl groups do not. Therefore, only the t-butoxycarbonyl groups can be selectively hydrolyzed and deprotected to carboxyl groups. Therefore, the acid value of the hydrophilic block (A3) can be adjusted by appropriately selecting a monomer containing a (meth)acrylate having a recyclable protecting group on the anionic group, which is the raw material monomer for A3.

[0135] Furthermore, in the polymer (E) represented by general formula (3), it is advantageous to use a block copolymer in which the polymer blocks (A2) and (A3) are regularly bonded in groups 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 an 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 the polymer block (A2) to the 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 by an inkjet method, and can produce printed materials with even better color development, etc.

[0136] 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 6 to 30, and most preferably 7 to 25. The number of anionic groups constituting the polymer block (A3) is preferably in the range of 3 to 20, more preferably 4 to 17, and most preferably 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.

[0137] The acid value of the polymer (E) represented by the general formula (3) is preferably 40 mgKOH / g to 400 mgKOH / g, more preferably 40 mgKOH / g to 300 mgKOH / g, and more preferably 40 mgKOH / g to 190 mgKOH / g, which can maintain the good ejection stability required when ejecting ink by an inkjet method, for example, and is more preferable in order to obtain an ink that can produce printed matter that is even more excellent in terms of abrasion resistance, etc.

[0138] The acid value of the polymer in the present invention is determined by the same acid value measurement method as that used for measuring the fine particles of the polymer (E) described above.

[0139] In the ink, the anionic groups of the polymer (E) are preferably neutralized.

[0140] Any known and commonly used basic compound can be used as the basic compound for neutralizing the anionic groups of the polymer (E), for example, inorganic basic substances such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and organic basic compounds such as ammonia, triethylamine, and alkanolamines.

[0141] 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, the polymer (E) is preferably neutralized so that the neutralization rate is 20% to 200%, more preferably 80% to 150%.

[0142] The polymer (E) can also be preferably used as a dispersing aid in ink rather than as a dispersant in an aqueous pigment dispersion. Using the polymer (E) as a dispersing aid can improve the long-term dispersion stability of the pigment and also improve circulation and filtration properties. In this case, the polymer (E) can be added during the production of the pigment dispersion or during the preparation of the ink. When the polymer (E) is used as a dispersing aid, the ratio of the pigment, dispersing agent, and polymer (E) is preferably pigment:dispersing agent:polymer (E) = 1:0.03:0.01 to 1:0.5:0.2.

[0143] (Other ink ingredients) 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.

[0144] (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.

[0145] (Water-soluble solvent) Examples of water-soluble solvents 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, ethylene glycol, polypropylene glycol, butanediol, pentanediol, hexanediol and related diols, propylene glycol laurate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol ether, dipropylene glycol ether, and cellosolves including triethylene glycol ether, methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, butyl alcohols such as 1-butanol and 2-butanol, pentyl alcohol and related alcohols, sulfolane; lactones such as gamma-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, ethyl lactate, etc. can be used alone or in combination of two or more;

[0146] Among the above-mentioned water-soluble solvents, 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. It is preferable to use a combination of glycerin and ethylene glycol or propylene glycol in order to obtain an ink that penetrates into a recording medium such as a fabric, dries easily, and can be prevented from drying or solidifying in the nozzles and filters of an ink-circulating inkjet head.

[0147] 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 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 drying rate after landing on the recording medium, and obtaining an ink that is clear and can produce printed matter 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.

[0148] (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.

[0149] As the surfactant, various anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. can be used, and it is preferable to use anionic surfactants and nonionic surfactants.

[0150] 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 dodecylbenzenesulfonates, isopropylnaphthalenesulfonates, monobutylphenylphenol monosulfonates, monobutylbiphenylsulfonates, and dibutylphenylphenol disulfonates.

[0151] Examples of the nonionic surfactant 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.

[0152] 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.

[0153] The surfactant preferably has an HLB value in the range of 4 to 20, in order to stably maintain the state in which the surfactant is dissolved in the ink containing water as the main solvent.

[0154] 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 more preferably 0.1% to 1.5% by mass, relative to the total amount of the ink. An inkjet ink containing the surfactant in the above range exhibits good wettability of the ejected droplets to the fabric surface, sufficient wet-spreading on the fabric, and is preferred for preventing mottle on the printed material. Furthermore, an ink containing the surfactant in the above range exhibits the effect of improving wettability to the fabric.

[0155] Examples of sugars include monosaccharides and polysaccharides, such as glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitose, maltose, cellobiose, sucrose, trehalose, and maltotriose, as well as alginic acid and its salts, cyclodextrins, and celluloses.

[0156] Examples of preservatives include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, and 1,2-dibenzisothiazolin-3-one (Proxel GXL, Proxel XL-2, Proxel LV, Proxel AQ, Proxel BD20, and Proxel DL, available from Arch Chemicals).

[0157] Specific examples of viscosity modifiers include mainly water-soluble natural or synthetic polymers such as carboxymethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, gum arabic, and starch.

[0158] Specific examples of pH adjusters include collidine, imidazole, phosphoric acid, 3-(N-morpholino)propanesulfonic acid, tris(hydroxymethyl)aminomethane, and boric acid.

[0159] 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).

[0160] Examples of antioxidants or ultraviolet absorbers include allophanates such as allophanate and methyl allophanate, biurets such as biuret, dimethyl biuret, and tetramethyl biuret, L-ascorbic acid and salts thereof, Tinuvin 328, 900, 1130, 384, 292, 123, 144, 622, 770, 292, Irgacor 252, 153, Irganox 1010, 1076, 1035, and MD1024 manufactured by Ciba-Geigy Corporation, and oxides of lanthanides.

[0161] (Method for manufacturing 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.

[0162] Examples of methods for producing the aqueous pigment dispersion include the following methods (1) to (3). (1) A method for 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 kneading machine 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 the preparation of 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.

[0163] The kneading machine is not particularly limited, and examples thereof include a Henschel mixer, a pressure kneader, a Banbury mixer, an intensive mixer, a planetary mixer, and a butterfly mixer.

[0164] As the stirring and dispersing device, for example, an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a Dyno Mill, a Dispermat, an SC Mill, a Nanomizer, etc. can be used alone or in combination of two or more types.

[0165] The aqueous pigment dispersion to be used preferably contains 5% by mass to 60% by mass of pigment relative to the total amount of the aqueous pigment dispersion, in order to obtain an ink that can form printed matter with high image density and has excellent dispersion stability, and it is more preferable to use an aqueous pigment dispersion containing 10% by mass to 50% by mass of pigment.

[0166] Furthermore, since coarse particles contained in the aqueous pigment dispersion can cause deterioration of image characteristics, it is preferable to use an aqueous pigment dispersion from which coarse particles have been removed by centrifugation, filtration, or the like before or after producing the ink.

[0167] When producing the aqueous pigment dispersion, the dispersion step may be followed by an impurity removal step 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.). The ion exchange uses a known ion exchange resin. The ultrafiltration uses a known ultrafiltration membrane, and may be either a standard type or a double-capacity type.

[0168] Examples of a method for mixing the aqueous pigment dispersion obtained by the above method with the polyether-based urethane resin or the like include a method in which a mixture of the aqueous dispersion of the polyether-based urethane resin or the like is produced in advance, and then the mixture is mixed with the aqueous pigment dispersion, and a method in which the aqueous pigment dispersion and the aqueous dispersion of the polyether-based urethane resin are mixed, and then other additives such as a surfactant are further added.

[0169] In order to obtain a sufficient image density and to ensure good dispersion stability of the pigment in the ink, the inkjet textile printing ink of the present invention obtained by the above method preferably has a pigment mass ratio (pigment concentration) of 1 mass % to 20 mass % relative to the total amount of the ink.

[0170] 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 wet spread, print density, and waterfastness when printed on a fabric that is easily 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 suppress deterioration of components constituting the ink application or ejection device (e.g., ink ejection port, ink flow path, etc.) and to reduce the effects of ink adhesion to the skin.

[0171] The inkjet textile printing ink of the present invention can be used in a printing method using, for example, an ink-circulating inkjet head.

[0172] An example of a printing device equipped with the ink circulation type inkjet head is a printing device equipped with a head having an ink circulation structure that has an ink inflow path and an ink outflow path in addition to the ink ejection nozzles, and the ink flowing out from the outflow path passes through the inflow path and is then supplied back to the inkjet head. In addition, a printing device equipped with a filter in the circulation structure can be preferably used as the printing device.

[0173] The filter to be used preferably has a pore size in the range of 5 μm to 20 μm, and it is preferable to use a filter in the range of 5 μm to 10 μm in order to effectively remove foreign matter that may be generated near the nozzle.

[0174] The ink tank for supplying ink is not particularly limited, but may be a plastic bottle, a pouch-type ink bag, or an ink tank or ink bag with a circulation function.

[0175] Examples of recording media that can be used when producing printed matter using the inkjet textile printing ink of the present invention and the printing method or printing device include fabrics and film substrates.

[0176] (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.

[0177] The method for printing on the fabric may be, for example, a method in which the ink-jet printing ink of the present invention is printed on the fabric using a printing device equipped with an ink-circulating ink-jet head.

[0178] In this case, the shortest distance between the ink discharge ports of the ink circulation inkjet head and the fabric is preferably 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, in order to prevent contact between the surface of the fabric (recording surface) and the ink discharge ports, even if the fabric is significantly frayed or uneven, and to effectively prevent damage to the ink discharge ports and ink discharge defects due to 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 a printed material without streaks.

[0179] The shortest distance may be the distance (gap) from a plane (x) having an ink ejection port of the inkjet head to a position (y) where a perpendicular line to the plane (x) (a hypothetical perpendicular line to the plane (x)) intersects with the fabric.

[0180] In 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 are preferable in terms of producing printed matter with excellent image quality free of streaks and the like and obtaining printed matter with even better washing resistance.

[0181] (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.

[0182] (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.

[0183] 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 films and polyurethane films are preferred because the film conforms to the irregularities of the mesh of the fabric fibers, resulting in high fixability. On the other hand, from the viewpoint of excellent transfer quality and high color development, polyester films are preferred, and polyethylene terephthalate films are more preferred. Therefore, the film substrate preferably includes a polyester film, a polyolefin film, or a polyurethane film.

[0184] The release layer may be the same as the release layer of a known multilayer transfer film.The release layer may be a silicone layer or a non-silicone layer, and is not particularly limited.Methods for forming the release layer on the base film include coating, lamination, etc., but are not particularly limited.

[0185] When the film substrate has a multilayer structure, it may have layers other than the base film and the release layer, such as an antistatic treatment layer.

[0186] The film substrate is preferably preheated before printing.

[0187] 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 as the inkjet recording device, including, for example, inkjet recording devices equipped with a continuous jet type (charge control type, spray type, etc.) or on-demand type (piezo type, thermal type, electrostatic suction type, etc.) inkjet head. Furthermore, using an inkjet recording device using an ink circulation type inkjet head is preferred for achieving the effects of the present invention.

[0188] 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 fabrics, film substrates have little fuzz or unevenness. Therefore, the shortest distance is important for preventing contact between the recording surface and the ink discharge ports, and for producing streak-free printed matter, rather than for effectively preventing 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.

[0189] The inkjet textile printing ink may be dried on the film substrate. For example, this can be achieved 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 the water-soluble solvent contained in the inkjet textile printing ink remains in the printing layer, the remaining solvent may volatilize when the transfer film is heated for transfer to a transfer recipient, resulting in a decrease in 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 may be set appropriately depending on the drying temperature, for example, 1 minute or higher and 10 minutes or lower.

[0190] (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 the printed material 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.

[0191] 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. Meanwhile, 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 irregularities of the fiber mesh of the fabric, which is advantageous because it improves the fixation of the transferred printing layer to the fabric. The pressure is not particularly limited as long as the printing layer can be transferred, and is, for example, 100 g / cm. 2 More than 10000g / cm 2or less, preferably 200 g / cm 2 More than 5000g / cm 2 The pressing time is not particularly limited as long as the printing layer can be transferred, and is, for example, from 3 seconds to 5 minutes, preferably from 5 seconds to 1 minute.

[0192] (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.

[0193] (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.

[0194] The adhesive resin may be a liquid or a powder, but is preferably a powder (powder). When the adhesive resin is a powder, the adhesive resin adheres only to the printed surface by applying the adhesive resin without the inkjet printing ink being allowed to dry sufficiently on the film substrate, making it possible to use only the required amount of adhesive resin and reducing the energy and process required to dry the inkjet printing ink.

[0195] The adhesive resin application method is not particularly limited, and known application methods can be used. For small-volume printing on a sheet-fed basis, adhesive resin powder may be sprinkled manually on each printed item. For mass printing using a so-called roll-to-roll method, it is also preferable to use a commercially available DTF shaker (adhesive resin application device).

[0196] The method for producing a printed matter of the present invention may include other steps, such as a pre-treatment step, a post-treatment step, a drying step, etc., but is not limited to these.

[0197] (Push-in depth) The inkjet textile printing ink of the present invention is applied to a polyethylene terephthalate plate and dried to form a 15 μm-thick coating film, and the difference in indentation depth between that at 100° C. and that at 30° C. is 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 certain 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.

[0198] Measuring device: Cho Micro Indentation Hardness Tester ENT-5 (manufactured by Elionix) Sample: Spin-coat inkjet printing ink onto a polyethylene terephthalate plate to a film thickness of 15 μm, then dry it in an oven at 130°C for 15 minutes. Measurements are made after adjusting the temperature to 30°C and 100°C.

[0199] 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 HL is less than 250 nm. A difference in indentation depth HL of less than 250 nm means that there is no significant difference between the indentation depth at 100°C and that at 30°C. When such ink is heated by thermal transfer or other methods, even if 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. As a result, the coating film on the fabric is less likely to crack when stretched.

[0200] The ink of the present invention has an indentation depth difference HL value of 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 indentation depth difference HL value 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.

[0201] (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 inkjet textile printing ink 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 to a thickness of 15 μm, the difference in indentation depth between at 100°C and at 30°C is less than 250 nm. 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. [Example]

[0202] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0203] (Preparing the binder resin) <Production of binder resin 1> In a nitrogen-purged vessel equipped with a thermometer, nitrogen gas inlet tube, and 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 isocyanate groups at the molecular terminals. 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 reaction was continued. 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 the urethane resin dispersed in an aqueous medium, had a nonvolatile content of 35 mass%, a weight-average molecular weight of 270,000, an acid value of 20 mgKOH / g, and a polyether-based urethane resin with a glass transition temperature of -82°C. The flow initiation temperature of Binder Resin 1 was 183°C.

[0204] <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 2,000) 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 1,000), 100 parts by weight of polytetramethylene ether glycol (number average molecular weight 1,000), 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, yielding 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 reaction was allowed to proceed. 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. Binder Resin 2 was obtained, which contained a polyether-based urethane resin with a weight-average molecular weight of 50,000, an acid value of 11 mgKOH / g, a glass transition temperature of -77°C, and a nonvolatile content of 35% by weight, in which the urethane resin was dispersed in an aqueous medium. The flow initiation temperature of Binder Resin 2 was 185°C.

[0205] <Binder resin 3> As the binder resin 3, Neorez R-967 (manufactured by DSM), which is a polyether urethane resin, was used.

[0206] <Production of binder resin 4> In a nitrogen-purged vessel equipped with a thermometer, nitrogen gas inlet tube, and 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. The mixture was reacted at 80°C for 3 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having isocyanate groups at the molecular terminals. 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. After that, 3831 parts by weight of water was added. Next, 22 parts by mass of an 80% by mass aqueous solution of hydrazine was added and reacted. 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 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.

[0207] <Production of binder resin 5> In a nitrogen-substituted vessel equipped with a thermometer, nitrogen gas inlet tube, and stirrer, 1,000 parts by weight of polycarbonate polyol (number average molecular weight 2,000) 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 above to neutralize the carboxyl groups in the urethane prepolymer. After that, 3,993 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 non-volatile 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.

[0208] <Production of binder resin 6> In a nitrogen-purged vessel equipped with a thermometer, nitrogen gas inlet tube, and 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 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 isocyanate groups at the molecular terminals. 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 with a nonvolatile content of 35 mass% in an aqueous medium, a weight-average molecular weight of 75,000, an acid value of 23 mgKOH / g, and a glass transition temperature of -37°C. The flow initiation temperature of Binder Resin 6 was 100°C.

[0209] <Production of binder resin 7> In a nitrogen-purged vessel equipped with a thermometer, nitrogen gas inlet tube, and 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 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 isocyanate groups at the molecular terminals. 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 with a nonvolatile content of 35 mass% in an aqueous medium, a weight-average molecular weight of 202,000, an acid value of 26 mgKOH / g, and a glass transition temperature of -27°C. The flow initiation temperature of Binder Resin 7 was 164°C.

[0210] <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.

[0211] <Binder resin 9> As the binder resin 9, Neorez R-600 (manufactured by DSM), which is a polyether-based urethane resin, was used.

[0212] <Binder resin 10> As the binder resin 10, M-141 (manufactured by Seiko PMC Corporation), an acrylic resin, was used.

[0213] (Production Example 1: Production of aqueous pigment dispersion (A1)) A mixture of 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 was stirred and 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 containing 0.5 mm zirconia beads at a filling rate of 90%. Next, the dispersion was collected, diluted with ion-exchanged water to a pigment concentration of 40%, and mixed to obtain an aqueous pigment dispersion (A1).

[0214] (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 tube reactors P1 and P2 shown in Figure 1, and a polymer was obtained by living anionic polymerization.

[0215] Next, the polymer obtained in the above step 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 by a reaction modifier (α-methylstyrene (α-MeSt)) introduced from the tube reactor P3.

[0216] 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. Then, the living anionic polymerization reaction was quenched by supplying methanol to produce a block copolymer (PA-1) composition.

[0217] When producing the block copolymer (PA-1) composition, the reaction temperature was set to 24°C by immersing the entire microreactor shown in FIG. 1 in a thermostatic chamber.

[0218] 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.

[0219] The resulting block copolymer (PA-1) composition was hydrolyzed by treatment with a cation exchange resin, followed by distillation under reduced pressure, and the resulting solid was pulverized to obtain polymer E, a powdery dispersing aid with a weight-average molecular weight of 2710 and an acid value of 145. The powdery polymer (E) was 100% neutralized with KOH and used as an aqueous solution with a resin solids content of 15%.

[0220] The various physical properties of the obtained dispersing aid, Polymer E, and each of the produced binder resins were measured as follows.

[0221] (Method for measuring weight average molecular weight (Mw)) Measurement was performed by gel permeation chromatography (GPC) under the following conditions.

[0222] Measurement equipment: High-speed GPC equipment (Tosoh Corporation "HLC-8220GPC") Column: The following columns manufactured by Tosoh Corporation were connected in series and used.

[0223] "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" (7.8mmI.D. x 30cm) x 1 Detector: RI (differential refractometer) Column temperature: 40℃ Eluent: tetrahydrofuran (THF) Flow rate: 1.0mL / 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.

[0224] (standard polystyrene) Tosoh Corporation's "TSKgel Standard Polystyrene A-500" Tosoh Corporation's "TSKgel Standard Polystyrene A-1000" 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 Tosoh Corporation's "TSKgel Standard Polystyrene F-2" Tosoh Corporation's "TSKgel Standard Polystyrene F-4" Tosoh Corporation's "TSKgel Standard Polystyrene F-10" Tosoh Corporation's "TSKgel Standard Polystyrene F-20" Tosoh Corporation's "TSKgel Standard Polystyrene F-40" Tosoh Corporation's "TSKgel Standard Polystyrene F-80" Tosoh Corporation's "TSKgel Standard Polystyrene F-128" Tosoh Corporation's "TSKgel Standard Polystyrene F-288" Tosoh Corporation's "TSKgel Standard Polystyrene F-550"

[0225] (Method for measuring acid value) Measurement was performed in accordance with JIS test method K 0070-1992. 0.5 g of sample was dissolved in THF, and titration was performed with 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

[0226] (Method for measuring flow 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 heating rate of 3°C / min).

[0227] (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.

[0228] 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.

[0229] 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.

[0230] (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.

[0231] (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), and then dried with hot air at 130° C. for 15 minutes to obtain a white ink coating film of approximately 15 μm.

[0232] (Measurement of indentation depth) The ink coating film obtained by the above method was measured for indentation depth using an ultra-microindentation hardness tester ENT-5 (manufactured by Elionix) 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). 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, HL, was calculated and evaluated according to the following criteria. The evaluation results are shown in Tables 1 to 3. ○: Difference in indentation depth HL is less than 250 nm △: Difference in indentation depth HL is 250 nm or more but less than 500 nm ×: The difference in indentation depth HL is 500 nm or more and less than 800 nm ××: Indentation depth difference HL is 800 nm or more

[0233] (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 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.

[0234] 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. 〇: More than 120 hours after starting circulation ×: Less than 120 hours after starting circulation

[0235] (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. The film was then left to stand for 30 minutes to obtain a transfer film. Subsequently, adhesive resin powder (Europort DTF hot melt powder) 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 a black cotton knit at 140°C for 5 seconds to obtain textile prints for Examples 1-2 and Comparative Examples 1-8.

[0236] (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. 〇: L*≧92.0 △:90.0≦L*<92.0 ×:L*<90.0

[0237] (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: Even if the ink-printed area is stretched more than 10 times, the coating film does not crack and whiteness is maintained. 4: If the ink-printed area is stretched 7 to 10 times, the coating will crack. 3: If the ink-printed area is stretched 4 to 6 times, the coating will crack. 2: If the ink-printed area is stretched two or three times, the coating will crack. 1: The coating cracks when the ink-printed area is stretched just once.

[0238] [Table 1]

[0239] [Table 2]

[0240] [Table 3]

[0241] The product names and manufacturing company 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: Acetylenic surfactant (EVONIK) Surfynol 104PG50: Acetylenic surfactant (EVONIK) ACTICIDE B-20: Preservative (manufactured by Thor Japan Co., Ltd.)

[0242] The inks of Examples 1 and 2 of the present invention produced printed matter with high whiteness, no 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. [Explanation of symbols]

[0243] 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

1. 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 inkjet textile printing ink described in claim 1, wherein the difference in indentation depth between the inkjet textile printing ink at 100°C and the inkjet textile printing ink at 30°C when the inkjet textile printing ink is applied to a polyethylene terephthalate plate and dried to a thickness of 15 μm is less than 250 nm.

3. The inkjet printing ink according to claim 1, wherein the glass transition temperature (Tg) of the polyether urethane resin is -95 to -0°C.

4. An inkjet textile printing ink according to claim 1 or 2, wherein the content of the polyether-based urethane resin relative to the total amount of the inkjet textile printing ink is in the range of 1 to 22 mass%.

5. 3. The ink-jet printing ink according to claim 1, wherein the polyether-based urethane resin has a flow-initiation temperature of 170 to 195°C.

6. An inkjet textile printing ink according to claim 1 or 2, wherein the content of the surfactant is in the range of 0.001 to 2 mass % relative to the total amount of the inkjet textile printing ink.

7. 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.

8. 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.

9. A textile print comprising a fabric printed with the inkjet textile printing ink according to claim 1 or 2.

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