Treatment liquid for inkjet and inkjet printing device

Abstract

An aspect of the present application relates to a treatment liquid for inkjet, which contains a water-soluble cationic polymer and an organic acid salt, wherein the content of the water-soluble cationic polymer is 0.1% by weight or more and less than 10% by weight, relative to the total amount of the treatment liquid.

Description

TECHNICAL FIELD

[0001] The present application relates to a treatment liquid for inkjet. Further, it relates to an inkjet printing apparatus using the treatment liquid. BACKGROUND

[0002] In the inkjet recording method, it is known to coat a pre-treatment liquid before coating ink. For example, a method using a treatment liquid containing a coagulant as a component that forms a coagulum with a color material in ink has been proposed.

[0003] Patent Literature 1 discloses an image forming method including: a pre-treatment liquid application step of applying a pre-treatment liquid to a surface side having a coating layer of a recording medium having the coating layer on at least one surface of a support; and an image forming step of forming an image by jetting an aqueous ink onto the recording medium to which the pre-treatment liquid is applied by an inkjet method, wherein the pre-treatment liquid is a pre-treatment liquid containing at least a water-soluble cationic polymer, an ammonium salt of an organic acid, and water, the content percentage of the water-soluble cationic polymer in the pre-treatment liquid is 10 to 70 mass%, and the content percentage of the ammonium salt of an organic acid is 1 to 40 mass%.

[0004] Further, Patent Literature 2 discloses an inkjet recording method including: a treatment liquid attachment step of attaching a treatment liquid containing a coagulant to a recording medium; and an ink attachment step of attaching an aqueous ink composition to the recording medium, wherein one or two or more kinds of a metal salt, a cationic polymer, and an organic acid are contained as the coagulant.

[0005] Prior Art Documents

[0006] Patent Literature

[0007] Patent Literature 1: Japanese Patent Publication No. 2014-15008

[0008] Patent Literature 2: Japanese Patent Publication No. 2020-104486 SUMMARY

[0009] One aspect of the present application relates to a treatment liquid for inkjet containing a water-soluble cationic polymer and an organic acid salt, wherein the content of the water-soluble cationic polymer is 0.1% by weight or more and less than 10% by weight, relative to the total amount of the treatment liquid. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a schematic view showing an embodiment of an inkjet printing apparatus using the treatment liquid for inkjet of the present embodiment. DETAILED DESCRIPTION

[0011] The invention described in Patent Document 1 described above is an image forming method of applying (coating) a pretreatment liquid for coagulating ink pigments to a recording medium, drying it, and then forming an image by ejecting an aqueous ink by an inkjet method, and the concentration of the cationic polymer in the treatment liquid is very high (10 mass% or more). The treatment liquid containing the cationic polymer at such a high concentration cannot be ejected from a treatment head, so a step of coating the treatment liquid before ejecting the ink is required, and this is troublesome.

[0012] Furthermore, when the treatment liquid described in Patent Document 2 described above is used, there is a concern that sufficient coagulability of the ink cannot be obtained.

[0013] In addition, the technologies described in Patent Documents 1 and 2 described above are inkjet image forming methods for printing mainly on paper media such as ordinary paper, recording media having low liquid absorption such as film sheets, and the like. Therefore, the purpose is to form a good image in which bleeding and the like are suppressed, and use in textile printing of cloth and the like is not much considered. In the case where inkjet recording is used for textile printing, it is required to improve rubbing color fastness and washing color fastness, and to suppress the cloth of the textile printing target from becoming hard, and to improve texture such as texture and the like.

[0014] Hereinafter, embodiments to which the present invention pertains will be specifically described, but the present invention is not limited to these.

[0015] [Inkjet treatment liquid]

[0016] The inkjet treatment liquid (hereinafter, sometimes simply referred to as "treatment liquid") pertaining to an embodiment of the present invention contains a water-soluble cationic polymer and an organic acid salt, and the content of the water-soluble cationic polymer is 0.1 mass% or more and less than 10 mass% with respect to the total amount of the treatment liquid.

[0017] The treatment liquid of the present embodiment is a pretreatment liquid that is attached to a recording target before ink. The water-soluble cationic polymer and the organic acid salt contained in the treatment liquid react with and coagulate pigments contained in ink attached later, and excellent colorability can be ensured.

[0018] By the content of the water-soluble cationic polymer being 0.1 mass% or more and less than 10 mass% with respect to the total amount of the treatment liquid, the treatment liquid of the present embodiment can be ejected from an inkjet head member, and therefore, a step of coating by a roll coating method or a blade coating method or the like can be omitted. That is, since the treatment liquid of the present embodiment can be ejected by an inkjet member as well as ink, it can be attached to a recording target easily.

[0019] Further, in the case where the treatment liquid of the present embodiment is used for printing, in addition to the above advantages, it has the advantage that the wet rubbing resistance and the color fastness to washing can be improved, and the texture of the cloth is also good. In particular, by containing the water-soluble cationic polymer in the above range, the resistance to wet rubbing becomes stronger. If the content of the water-soluble cationic polymer is 10% by weight or more, sufficient color fastness to wet rubbing cannot be obtained.

[0020] That is, the treatment liquid for inkjet according to the present application, in inkjet recording, can be ejected from the inkjet head member, and excellent colorability can be obtained. Further, in the case where the treatment liquid for inkjet of the present application is used for printing, it has the remarkable advantage that the wet rubbing resistance and the color fastness to washing can be improved, and the texture of the cloth is also good.

[0021] The water-soluble cationic polymer contained in the treatment liquid for inkjet of the present embodiment is not particularly limited as long as it is a water-soluble and positively charged cationic polymer, and cationic polymers such as ammonium-containing polymers, amine-containing polymers, polyallylamine, polyvinylamine, polyimine, polyvinylpyrrolidone, polyvinyl imidazole, polyvinyl benzyl phosphonium, polyalkyl allyl ammonium, polyamidine, and polyamine sulfone can be exemplified. Among them, from the viewpoint of obtaining more excellent colorability, quaternary ammonium-containing polymers, diallyl dimethyl ammonium sulfur dioxide copolymer, diallyl dimethyl ammonium chloride acrylamide copolymer, diallyl dimethyl ammonium chloride polymer, dimethylamine-ammonia-epichlorohydrin polycondensate, dimethylamine-ammonia-epichlorohydrin polycondensate, and the like are particularly preferable. These can be used alone or in combination with two or more.

[0022] The weight average molecular weight of the cationic polymer used in the present embodiment is not particularly limited, and is preferably around 1000 to 10000. It is considered that if the molecular weight is within this range, the ejection property from the inkjet head will be better.

[0023] The content of the cationic polymer is preferably 0.1% by weight or more and less than 10% by weight, relative to the total amount of the treatment liquid. A more preferable lower limit of the content of the cationic polymer is 0.5% by weight or more, further 1% by weight or more. In addition, a more preferable upper limit is 9% by weight or less, further 8% by weight or less.

[0024] The treatment liquid of the present embodiment further contains an organic acid salt. As the organic acid salt, organic acid magnesium salts, organic acid ammonium salts, organic acid calcium salts, organic acid aluminum salts, organic acid sodium salts, organic acid potassium salts, and the like can be exemplified. In addition, these organic acid salts can contain water of hydration in their raw material form. As the organic acid magnesium salt used in the present embodiment, magnesium acetate, magnesium lactate, magnesium sulfate, trimagnesium phosphate, and the like can be exemplified. In addition, the organic acid ammonium salt used in the present embodiment is not particularly limited, and from the viewpoint of solubility in water, it is appropriate to use ammonium acetate, ammonium propionate, ammonium oxalate, ammonium tartrate, ammonium lactate, ammonium succinate (diammonium succinate), diammonium malonate, ammonium malate, ammonium citrate, hydrogen diammonium citrate, triammonium citrate, and L-glutamic acid ammonium, and the like.

[0025] In addition, although the organic acid ammonium salt is excellent in coloring properties and the like, it can generate an odor, and thus it is more preferable to use an organic acid magnesium salt.

[0026] The content of the organic acid salt is preferably around 0.1 to 15% by weight, relative to the total amount of the treatment liquid. It is considered that by making the content of the organic acid salt within the range, the coagulation effect of the ink components is improved, and the coloring properties (image density) are further improved. A more preferable lower limit of the content of the organic acid salt is 0.5% by weight or more, further 1% by weight or more. In addition, a more preferable upper limit is 14% by weight or less, further 13% by weight or less.

[0027] In addition, in the treatment liquid of the present embodiment, it is more preferable that the content of the organic acid salt is more than the content of the water-soluble cationic polymer. It is considered that by doing so, the texture (tactile sensation) of the cloth of the printing target when printing becomes good. At this time, the content of the organic acid salt is preferably 1 to 15% by weight, relative to the total amount of the treatment liquid, and it is considered that by doing so, the above-mentioned effects can be further obtained.

[0028] In the case where the organic acid salt is an organic acid magnesium salt, if the content thereof is around 5 to 11% by weight, relative to the total amount of the treatment liquid, it is possible to maintain the color fastness to washing and further suppress the cost of the pre-treatment liquid. On the other hand, the content of the organic acid magnesium salt is also preferably 12 to 15% by weight, relative to the total amount of the treatment liquid. It is considered that by doing so, the color fastness to washing is further improved when printing.

[0029] In addition to the above-mentioned components, the treatment liquid of the present embodiment preferably contains a metal salt. It is considered that by containing a metal salt, the above-mentioned coagulation effect can be further obtained, and in addition, the color fastness to washing when used for printing can be improved.

[0030] The metal salt that can be used in the present embodiment is preferably a polyvalent metal salt composed of a divalent or more metal ion and an anion, and examples of the divalent or more metal ion include ions of calcium, magnesium, copper, nickel, zinc, barium, aluminum, titanium, strontium, chromium, cobalt, iron, and the like.

[0031] Examples of the specific metal salt include calcium acetate, aluminum acetate, calcium carbonate, calcium nitrate, calcium chloride, calcium sulfate, calcium hydroxide, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, copper nitrate, and the like. These metal salts can be used alone or in combination of two or more. Among these, from the viewpoint of excellent water solubility, calcium acetate or the like is more preferably used. In addition, these metal salts can contain water of hydration in their raw material form.

[0032] When the treatment liquid of the present embodiment contains a metal salt, the content thereof is preferably about 0.1 to 5% by mass with respect to the total amount of the treatment liquid. A more preferable lower limit value of the content of the metal salt is 0.5% by mass or more, and further 1% by mass or more. In addition, a more preferable upper limit value is 4% by mass or less, and further 3% by mass or less.

[0033] In addition, in the treatment liquid of the present embodiment, it is preferable that the content of the organic acid salt be more than the content of the metal salt. It is considered that by doing so, the above-mentioned color fastness to washing can be improved, and in addition, the hand feeling can be made better. At this time, from the viewpoint of further obtaining the above-mentioned effects, it is preferable that the content of the metal salt be 0.1 to 5% by mass with respect to the total amount of the treatment liquid, and the content of the organic acid salt be 1 to 15% by mass with respect to the total amount of the treatment liquid.

[0034] In the treatment liquid of the present embodiment, the balance other than the above-mentioned components is usually water, or an aqueous solvent composed of water and an organic solvent.

[0035] As the organic solvent that can be contained in the treatment liquid of the present embodiment, glycols, alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, vegetable oils, and the like can be exemplified. As the water-soluble organic solvent, for example, polyhydric alcohols, ether compounds of polyhydric alcohols, nitrogen-containing compounds, alcohol compounds, sulfur-containing compounds, propylene carbonate, and ethylene carbonate can be exemplified.

[0036] As the polyhydric alcohol, for example, a first diol compound having 5 or more and 8 or less carbon atoms, a second diol compound having 2 or more and 4 or less carbon atoms, 1,2,6-hexanetriol, glycerol, trimethylolpropane, a sugar alcohol (e.g., xylitol), and a saccharide (e.g., xylose, glucose, and galactose) can be exemplified.

[0037] As the first diol compound, for example, 2-methylpentane-2,4-diol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol, and 1,2-hexanediol can be exemplified.

[0038] As the second diol compound, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, butylene glycol, and diethylene glycol can be exemplified.

[0039] As the ether compound of the polyhydric alcohol, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and an oxirane adduct of diglycerol can be exemplified.

[0040] As the nitrogen-containing compound, for example, pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, and triethanolamine can be exemplified.

[0041] As the alcohol compound, for example, ethanol, isopropanol, butanol, and benzyl alcohol can be exemplified.

[0042] As the sulfur-containing compound, for example, thiodiethanol, thiodiglycerol, sulfolane, and dimethyl sulfoxide can be exemplified.

[0043] Among the above-mentioned organic solvents, a diol such as propylene glycol or the like is preferably used.

[0044] The above-mentioned organic solvent can be used alone or two or more kinds can be used in combination.

[0045] When the treatment liquid of the present embodiment contains an organic solvent, the content thereof is preferably 3% by mass or more and 50% by mass or less with respect to the total amount of the treatment liquid. By containing an organic solvent within the range, it is possible to provide a treatment liquid that can provide a viscosity that enables stable ejection and can prevent drying of the treatment liquid.

[0046] Further, the treatment liquid of the present embodiment can contain a surfactant for the purpose of adjusting the surface tension to be appropriate. The surfactant that can be used is not particularly limited, and a nonionic surfactant, a cationic surfactant, an anionic surfactant, or the like can be exemplified.

[0047] When the treatment liquid of the present embodiment contains a surfactant, the content thereof is preferably 0.1% by weight or more and 5% by weight or less with respect to the total amount of the treatment liquid. By containing a surfactant within the range, there is an advantage that a treatment liquid having a surface tension that can provide stable ejection can be provided.

[0048] The treatment liquid of the present embodiment can contain other additives within a range not impairing the effects of the present application. As the additives, for example, a dissolution stabilizer, a drying preventive, an antioxidant, a viscosity modifier, a pH modifier, and a mildew preventive, and the like can be exemplified.

[0049] The treatment liquid of the present embodiment is particularly suitable for use in inkjet printing. In the case of using a pigment ink capable of printing on a variety of cloths, it is necessary to fix the pigment on the surface of the cloth. If it cannot be fixed on the surface of the cloth, there is a problem of poor rubbing fastness. On the other hand, if the pigment and the binder resin do not remain on the surface of the cloth but penetrate deeply, not only the coloring property becomes poor, but also there is a problem of a hard hand, i.e., poor texture, due to the ink and the binder resin entering between the fibers. Further, in the case of a printed article, it is also required that even if a detergent is mixed, the printed image is difficult to peel off (washing fastness).

[0050] By using the treatment liquid of the present embodiment, the above problems can be improved. That is, according to the treatment liquid of the present embodiment, when a printed article is produced, excellent coloring property of the ink can be exerted. Further, since it also has the advantage of improving wet rubbing fastness and washing fastness, and the hand of the cloth is also excellent, it is very useful in industrial applications.

[0051] In the present embodiment, the treatment liquid does not require a process such as pre-coating and drying (pad dyeing and drying) of the cloth, and by placing the treatment liquid on the cloth with an inkjet system, there is also an advantage that the trouble of adjusting the cloth can be greatly reduced.

[0052] [Inkjet printing device]

[0053] Next, an inkjet printing device to which the present embodiment relates will be described.

[0054] The inkjet printing device 10 to which the present embodiment relates at least includes a treatment head 1 that ejects a treatment liquid to at least an image forming region of a printed article, a recording head 2 that ejects an ink to the image forming region of the printed article, and a placement table 3 for conveying the printed article, wherein the treatment liquid ejected from the treatment head is the above-mentioned treatment liquid for inkjet. In addition, for the convenience of understanding, Figure 1 Each of the constituent elements is mainly schematically shown, and the size, the number, and the like of each of the constituent elements shown in the drawing can be appropriately changed. Figure 1is a side view showing main portions of an inkjet printing device 10 as an example of an inkjet printing device to which the present embodiment is applied. Figure 1 The inkjet printing device 10 shown in FIG. 1 is a flatbed type inkjet printing device.

[0055] The inkjet printing device 10 to which the present embodiment is applied performs processing on a printing target P using the processing liquid of the present embodiment described above. Due to the use of the processing liquid to which the present embodiment is applied, according to the inkjet printing device 10, it is possible to obtain a printing product that is excellent in colorability and in wet rubbing fastness, washing fastness, texture, and the like.

[0056] Figure 1 The inkjet printing device 10 shown in FIG. 1 includes a processing head 1, a recording head 2, and a platen 3. The recording head 2 has a first recording head 2a, a second recording head 2b, a third recording head 2c, and a fourth recording head 2d.

[0057] The processing head 1 ejects the processing liquid toward at least an image formation region of the printing target P. The processing liquid used here is the processing liquid described above. As the processing head 1, there is no particular limitation, and examples include a piezoelectric type head and a thermal inkjet type head.

[0058] The recording head 2 ejects ink toward an image formation region of the printing target P. The first recording head 2a, the second recording head 2b, the third recording head 2c, and the fourth recording head 2d of the recording head 2 each eject ink of a different color (for example, yellow ink, magenta ink, cyan ink, and black ink). The number of recording heads is not limited to four, and the number of recording heads can be one to three or five or more. As the recording head 2, there is no particular limitation, and examples include a piezoelectric type head and a thermal inkjet type head.

[0059] The printing target P is placed on the platen 3. The processing head 1 and the recording head 2 are disposed above the platen 3 in a manner that enables ejection of ink and the processing liquid toward the printing target P. The platen 3 is horizontally moved in a direction from the processing head 1 toward the recording head 2 (for example, the left direction of FIG. 1) under the drive of a motor (not shown). The printing target P on the platen 3 is conveyed by the horizontal movement of the platen 3. Figure 1

[0060] The printing target P can be a woven fabric or a knitted fabric. As the printing target P, examples include cotton cloth, silk cloth, hemp cloth, acetate cloth, rayon cloth, nylon cloth, polyurethane cloth, and polyester cloth.

[0061] ​In the present embodiment, when the printed matter is produced, first, the placement table 3 on which the print target P is placed is horizontally moved to convey the print target P to a position facing the processing head 1. Then, the processing liquid is ejected from the processing head 1 toward the print target P. The processing head 1 can eject the processing liquid only to the image formation region of the print target P, can eject the processing liquid to a region wider than the image formation region of the print target P, or can eject the processing liquid to the entire surface of the print target P. In order to reduce the amount of the processing liquid used to suppress deterioration of the tactile sensation of the printed matter, it is preferable that the processing head 1 eject the processing liquid only to the image formation region of the print target P. Since the processing head 1 can accurately control the ejection position of the processing liquid, the processing liquid can be ejected only to the region to which ink has been ejected. In order to accurately control the ejection position of the processing liquid, it is preferable that the distance between the processing head 1 and the print target P be 1 mm or more and 5 mm or less.

[0062] After the processing liquid is ejected from the processing head 1, the placement table 3 on which the print target P is placed is further horizontally moved to convey the print target P to a position facing the recording head 2. Then, ink is ejected from the recording head 2 toward the image formation region of the print target P. In this way, an image is formed on the image formation region of the print target P using ink.

[0063] Although not illustrated, after the recording head 2 ejects ink, the placement table 3 on which the print target P is placed can be further horizontally moved to eject a post-processing liquid from another processing head. The post-processing liquid is also a non-coloring processing liquid that does not color even if it adheres to the print target P, and is a processing liquid that functions to improve the fixing property and the firmness (resistance to friction and scratching) of the ink image printed on the print target P using the recording head 2. As such a post-processing liquid, a processing liquid of a silicone-based or the like can be used. In this way, a treatment film is formed on the image formed on the image formation region of the print target P using the post-processing liquid.

[0064] After the post-processing liquid is ejected, the placement table 3 on which the print target P is placed is further horizontally moved to convey the print target P to a position facing a heating section (not illustrated), and the ink and the processing liquid are dried by heating the print target P by the heating section. The heating temperature is, for example, 120°C or more and 180°C or less. The heating time is, for example, 1 minute or more and 10 minutes or less. By heating, volatile components contained in the ink and the processing liquid are dried, thereby promoting the fixation of the ink and the processing liquid on the print target P. As a result, the print target P on which an image is formed using ink and which is treated using a processing liquid is formed.

[0065] In addition, the treatment liquid of the present embodiment is not limited to use in the inkjet printing device 10 described above, and can be changed as shown in the following modified examples, for example. For example, the inkjet printing device 10 can be provided with a sprayer that sprays the treatment liquid instead of the treatment head 1 that ejects the treatment liquid. Alternatively, the treatment using the treatment liquid can be performed by immersing the printing target P in a tank in which the treatment liquid is stored. Further, in the inkjet printing device 10 described above, the stage 3 is horizontally moved, but the treatment head 1 and the recording head 2 can be horizontally moved while the stage 3 is fixed. Alternatively, the stage 3 can be horizontally moved or the treatment head 1 and the recording head 2 can be horizontally moved in the conveyance direction of the printing target P, and the treatment head 1 and the recording head 2 can be horizontally moved in a direction parallel to the conveyance direction of the printing target P.

[0066] That is, as long as the treatment head 1 and the recording head 2 are provided, the effects of using the treatment liquid of the present embodiment can be obtained regardless of the type of the inkjet printing device.

[0067] [Ink]

[0068] The ink used together with the treatment liquid of the present embodiment for inkjet recording and the ink used in the printing device is not particularly limited, and an ink containing a pigment and an aqueous medium can be used, for example. The ink can also contain at least one selected from the group consisting of a surfactant, a polyol, and a binder resin particle, as needed.

[0069] The pigment can use a dispersible pigment that exists dispersed in an aqueous medium, for example. From the viewpoint of obtaining an ink excellent in image density, hue, and color stability, the Dv50 of the pigment is preferably 30 nm or more and 250 nm or less, more preferably 70 nm or more and 160 nm or less. 50 Preferably, the Dv50 of the pigment is 30 nm or more and 250 nm or less, more preferably 70 nm or more and 160 nm or less.

[0070] As the pigment, a yellow pigment, an orange pigment, a red pigment, a blue pigment, a violet pigment, and a black pigment can be exemplified. As the yellow pigment, C.I. Pigment Yellow (74, 93, 95, 109, 110, 120, 128, 138, 139, 151, 154, 155, 173, 180, 185, and 193), for example, can be exemplified. As the orange pigment, C.I. Pigment Orange (34, 36, 43, 61, 63, and 71), for example, can be exemplified. As the red pigment, C.I. Pigment Red (122 and 202), for example, can be exemplified. As the blue pigment, C.I. Pigment Blue (15, more specifically 15:3), for example, can be exemplified. As the violet pigment, C.I. Pigment Violet (19, 23, and 33), for example, can be exemplified. As the black pigment, C.I. Pigment Black (7), for example, can be exemplified.

[0071] The percentage content of the pigment with respect to the weight of the entire ink is preferably 1% by weight or more and 12% by weight or less, and more preferably 1% by weight or more and 7% by weight or less. By making the percentage content of the pigment 1% by weight or more, it is possible to increase the image density of the formed recording material. In addition, by making the percentage content of the pigment 12% by weight or less, it is possible to obtain an ink with high fluidity.

[0072] In particular, the ink of the present embodiment preferably contains an anionic pigment. By virtue of this, the cationic polymer contained in the above-mentioned treatment liquid and the anionic pigment cause an electrically reactive aggregation on the surface of the recording object, and thus it is possible to inhibit the penetration of the binding resin (adhesive resin described later) contained in the ink into the recording medium. This is particularly important in the case where the recording medium is cloth, and it is possible to prevent the binding resin from penetrating into the gaps between the fibers and binding the fibers to each other. By virtue of this, it is possible to improve the texture (tactile sensation, etc.) of the printed cloth.

[0073] As the anionic pigment, specifically, an anionic pigment having a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, a benzenesulfonic acid group, a benzenecarboxylic acid group, or the like is more preferable.

[0074] The aqueous medium contained in the ink of the present embodiment is a medium in which water is the main component. The aqueous medium can function as a solvent, and can also function as a dispersion medium. As specific examples of the aqueous medium, water, or a mixture of water and a polar solvent can be given. As examples of the polar solvent contained in the aqueous medium, methanol, ethanol, isopropanol, butanol, and methyl ethyl ketone can be given. The percentage content of water in the aqueous medium is preferably 90% by weight or more, and particularly preferably 100% by weight. The percentage content of the aqueous medium with respect to the weight of the entire ink is preferably 5% by weight or more and 70% by weight or less, and more preferably 40% by weight or more and 60% by weight or less.

[0075] Further, by containing a surfactant in the ink, the wettability of the ink to the recording object is improved. As the surfactant, for example, anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants can be cited. The surfactant contained in the ink is preferably a nonionic surfactant. The nonionic surfactant is preferably a surfactant having an acetylene diol structure, and more preferably an acetylene diol ethylene oxide adduct. The HLB value of the surfactant is preferably 3 or more and 20 or less, more preferably 6 or more and 16 or less, and further preferably 7 or more and 10 or less. The HLB value of the surfactant is calculated, for example, by the Griffin method and according to the formula "HLB value = 20 x (sum of formula weights of hydrophilic portions) / molecular weight". In order to improve the image density while suppressing image offset, the percentage content of the surfactant with respect to the weight of the entire ink is preferably 0.1% by weight or more and 5.0% by weight or less, and more preferably 0.5% by weight or more and 2.0% by weight or less.

[0076] Further, by containing a polyol in the ink, the viscosity of the ink is appropriately adjusted. As the polyol contained in the ink, a diol or a triol is preferable. As the diol, for example, diol compounds, and more specifically, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol can be cited. As the triol, for example, glycerol can be cited.

[0077] In the case where the ink contains a polyol, in order to appropriately adjust the viscosity of the ink, the percentage content of the polyol with respect to the weight of the entire ink is preferably 5% by weight or more and 60% by weight or less, and more preferably 20% by weight or more and 50% by weight or less.

[0078] The binder resin particles contained in the ink of the present embodiment exist in a state of being dispersed in the aqueous medium. The binder resin particles function as a binder that bonds the printed object and the pigment. Therefore, by containing the binder resin particles in the ink, a printed matter having excellent pigment fixing property can be obtained.

[0079] As the resin contained in the binder resin particles, polyurethane resin, (meth)acrylate resin, styrene · (meth)acrylate resin, styrene-maleic acid copolymer, vinyl naphthalene-(meth)acrylic acid copolymer, and vinyl naphthalene · maleic acid copolymer can be cited. As the resin contained in the binder resin particles, polyurethane resin is preferable. The percentage content of the polyurethane resin in the binder resin particles is preferably 80% by weight or more, and more preferably 100% by weight.

[0080] The content percentage of the binder resin particles is preferably 1% by weight or more and 20% by weight or less, more preferably 2% by weight or more and 10% by weight or less, relative to the weight of the entire ink. If the content percentage of the binder resin particles is 1% by weight or more, a recording object having excellent pigment fixing properties can be obtained. On the other hand, if the content percentage of the binder resin particles is 20% by weight or less, the ink can be stably ejected to the recording object.

[0081] Furthermore, the ink of the present embodiment can contain, as necessary, publicly known additives (more specifically, a dissolution stabilizer, a drying preventing agent, an antioxidant, a viscosity adjusting agent, a pH adjusting agent, and a mildew preventive agent, etc.).

[0082] The ink used in the present embodiment is manufactured, for example, by mixing a pigment, an aqueous medium, and components added as necessary (for example, a surfactant, a polyol, and binder resin particles) using a stirrer. The mixing time is, for example, 1 minute or more and 30 minutes or less.

[0083] Example

[0084] Hereinafter, the present application will be further specifically described by way of examples, but the present application is not limited by any of the examples.

[0085] (Example 1)

[0086] After mixing 3 parts by weight (solid content) of "PAS-A5" (manufactured by Nippon Shokubai Co., Ltd.) as a water-soluble cationic polymer, 10 parts by weight of ammonium acetate as an organic acid salt, and 1 part by weight of "surfynol 440" (manufactured by Shin-Etsu Chemical Co., Ltd.) as a nonionic surfactant, 30 parts by weight of propylene glycol, and the balance of water (total 100 parts by weight) were mixed, the mixture was filtered with a 5-μm filter to obtain a treatment liquid 1.

[0087] (Example 2)

[0088] A treatment liquid 2 was obtained in the same manner as in Example 1, except that the content of the water-soluble cationic polymer "PAS-A5" (manufactured by Nippon Shokubai Co., Ltd.) was changed from 3 parts by weight to 9 parts by weight.

[0089] (Example 3)

[0090] A treatment liquid 3 was obtained in the same manner as in Example 1, except that the content of ammonium acetate was changed from 10 parts by weight to 15 parts by weight.

[0091] (Example 4)

[0092] A treatment liquid 4 was obtained in the same manner as in Example 1, except that the content of the water-soluble cationic polymer "PAS-A5" (manufactured by Nippon Shokubai Co., Ltd.) was changed from 3 parts by weight to 0.5 parts by weight.

[0093] (Example 5)

[0094] A treatment liquid 5 was obtained by mixing 3 parts by weight (solid content) of "PAS-A5" (manufactured by Nippon Shokubai Co., Ltd.) as a water-soluble cationic polymer, 15 parts by weight of ammonium acetate as an organic acid salt, 3 parts by weight of calcium acetate monohydrate as a metal salt, 1 part by weight of "surfynol 440" (manufactured by Shin-Etsu Chemical Co., Ltd.) as a nonionic surfactant, 30 parts by weight of propylene glycol, and the balance of water (total 100 parts by weight), followed by filtration with a 5 μm filter.

[0095] (Example 6)

[0096] A treatment liquid 6 was obtained in the same manner as in Example 5, except that the content of calcium acetate monohydrate was changed from 3 parts by weight to 5 parts by weight.

[0097] (Example 7)

[0098] A treatment liquid 7 was obtained in the same manner as in Example 5, except that the content of calcium acetate monohydrate was changed from 3 parts by weight to 6 parts by weight.

[0099] (Example 8)

[0100] A treatment liquid 8 was obtained in the same manner as in Example 1, except that the content of ammonium acetate was changed from 10 parts by weight to 16 parts by weight.

[0101] (Example 9)

[0102] A treatment liquid 9 was obtained in the same manner as in Example 5, except that the content of ammonium acetate was changed from 15 parts by weight to 5 parts by weight.

[0103] (Example 10)

[0104] A treatment liquid 10 was obtained in the same manner as in Example 2, except that the content of ammonium acetate was changed from 10 parts by weight to 9 parts by weight.

[0105] (Example 11)

[0106] A treatment liquid 11 was obtained in the same manner as in Example 1, except that ammonium acetate was changed to magnesium acetate tetrahydrate.

[0107] (Example 12)

[0108] A treatment liquid 13 was obtained in the same manner as in Example 3, except that the ammonium acetate was changed to magnesium acetate tetrahydrate.

[0109] (Example 13)

[0110] A treatment liquid 13 was obtained in the same manner as in Example 3, except that the ammonium acetate was changed to magnesium acetate tetrahydrate.

[0111] (Example 14)

[0112] A treatment liquid 14 was obtained in the same manner as in Example 4, except that the ammonium acetate was changed to magnesium acetate tetrahydrate.

[0113] (Comparative Example 1)

[0114] A treatment liquid 11 was obtained by mixing 10 parts by weight (solid content) of "PAS-A5" (manufactured by Nippon Shokubai Co., Ltd.) as a water-soluble cationic polymer, 10 parts by weight of ammonium acetate as an organic acid salt, 1 part by weight of a nonionic surfactant "surfynol 440" (manufactured by Shin-Etsu Chemical Co., Ltd.), 30 parts by weight of propylene glycol, and the balance of water (total 100 parts by weight) and filtering with a 5 μm filter.

[0115] (Comparative Example 2)

[0116] A treatment liquid 12 was obtained by mixing 15 parts by weight (solid content) of "PAS-A5" (manufactured by Nippon Shokubai Co., Ltd.) as a water-soluble cationic polymer, 3 parts by weight of ammonium acetate as an organic acid salt, 1 part by weight of a nonionic surfactant "surfynol 440" (manufactured by Shin-Etsu Chemical Co., Ltd.), 30 parts by weight of propylene glycol, and the balance of water (total 100 parts by weight) and filtering with a 5 μm filter.

[0117] (Comparative Example 3)

[0118] A treatment liquid 13 was obtained in the same manner as in Comparative Example 1, except that the content of ammonium acetate was changed from 10 parts by weight to 3 parts by weight.

[0119] (Comparative Example 4)

[0120] A treatment liquid 14 was obtained by mixing 3 parts by weight (solid content) of "PAS-A5" (manufactured by Nippon Shokubai Co., Ltd.) as a water-soluble cationic polymer, 1 part by weight of a nonionic surfactant "surfynol 440" (manufactured by Shin-Etsu Chemical Co., Ltd.), 30 parts by weight of propylene glycol, and the balance of water (total 100 parts by weight) and filtering with a 5 μm filter.

[0121] (Comparative Example 5)

[0122] A treatment liquid 15 was obtained in the same manner as in Comparative Example 4, except that the content of the water-soluble cationic polymer "PAS-A5" was changed from 3 parts by weight to 9 parts by weight.

[0123] (Comparative Example 6)

[0124] After 10 parts by weight of ammonium acetate as an organic acid salt, 1 part by weight of a nonionic surfactant "surfynol 440" (manufactured by Nippon Shokubai Co., Ltd.), 30 parts by weight of propylene glycol, and water were mixed (total 100 parts by weight), filtration was performed using a 5 μm filter to obtain a treatment liquid 16.

[0125] The mixing ratios of the treatment liquids of the above examples and comparative examples are summarized in Table 1.

[0126] Table 1

[0127] Cationic polymer Content [wt%] Ammonium salt of organic acid Content [wt%] Metal salt Content [wt%] Example 1 PAS-A5 3 Ammonium acetate 10 - - Example 2 PAS-A5 9 Ammonium acetate 10 - - Example 3 PAS-A5 3 Ammonium acetate 15 - - Example 4 PAS-A5 0.5 Ammonium acetate 10 - - Example 5 PAS-A5 3 Ammonium acetate 10 Calcium acetate 3 Example 6 PAS-A5 3 Ammonium acetate 10 Calcium acetate 5 Example 7 PAS-A5 3 Ammonium acetate 10 Calcium acetate 6 Example 8 PAS-A5 3 Ammonium acetate 16 - - Example 9 PAS-A5 3 Ammonium acetate 5 Calcium acetate 5 Example 10 PAS-A5 9 Ammonium acetate 9 - - Comparative Example 1 PAS-A5 10 Ammonium acetate 10 - - Comparative Example 2 PAS-A5 15 Ammonium acetate 3 - - Comparative Example 3 PAS-A5 10 Ammonium acetate 3 - - Comparative Example 4 PAS-A5 3 - - - - Comparative Example 5 PAS-A5 9 - - - - Comparative Example 6 - - Ammonium acetate 10 - -

[0128] (Preparation of ink)

[0129] An ink was prepared using an anionic pigment dispersion "AE-2078F" (manufactured by San'yo Pigment Co., Ltd.) having a pigment concentration of 20%, a polyurethane dispersion "SUPERFLEX 470" (manufactured by the First Industrial Co., Ltd.) having a solid content of 38%, a nonionic surfactant "sarfynol 440" (manufactured by Nippon Shokubai Co., Ltd.), propylene glycol, and water.

[0130] The mixing ratio of the ink was specifically 4% by weight of the pigment, 8% by weight of the polyurethane, 30% by weight of the propylene glycol, 1% by weight of the surfactant, and the balance water. After mixing in the above ratio, filtration was performed using a 5 μm filter to obtain the ink.

[0131] (Preparation of post-treatment liquid)

[0132] A post-treatment liquid was prepared using a silicone oil emulsion "POLON-MF-51" (manufactured by Shin-Etsu Chemical Co., Ltd.) having a silicone oil content of 39%, propylene glycol, and water. The mixing ratio was specifically 10% by weight of the silicone oil, 30% by weight of the propylene glycol, and the balance water. After mixing in the above ratio, filtration was performed using a 5 μm filter to obtain the post-treatment liquid.

[0133] <Printing>

[0134] A flatbed printing jig in which KJ4B heads manufactured by Kyocera Corporation were arranged in the conveyance direction was used for inkjet printing. A pre-treatment liquid was supplied to the first head, an ink was supplied to the second head, and a post-treatment liquid was supplied to the third head, and inkjet printing was performed under the following conditions.

[0135] Cloth used: Polyester Tropical

[0136] Cloth / head distance: 3 mm, head temperature: 25°C

[0137] Drying: 150°C for 3 minutes (oven)

[0138] <Assessment Test>

[0139] (Image density)

[0140] Color was measured using a fluorescence spectrophotometer FD-5 (manufactured by Konica Minolta, Inc.). The evaluation criteria are described below.

[0141] Image density (OD) 1.3 or more “O” good colorability

[0142] Image density (OD) less than 1.3 “X” poor colorability

[0143] (Rubbing fastness of color)

[0144] A solid image formed on the printed matter for evaluation was rubbed using a white cotton cloth for rubbing in accordance with the wet test of the rubbing tester II form (SCHICK form) method described in JIS L-0849:2013 (Test method for color fastness to rubbing). The degree of coloring of the white cotton cloth for rubbing after rubbing was evaluated in accordance with the “judgment criteria for discoloration and fading” described in Article 10 (Judgment of color fastness) of JIS L-0801:2011 (General rules for test methods for color fastness). The degree of coloring of the white cotton cloth for rubbing was judged using nine stages (1st, 1st to 2nd, 2nd, 2nd to 3rd, 3rd, 3rd to 4th, 4th, 4th to 5th, and 5th in order of degree of contamination from high to low). The smaller the degree of coloring of the white cotton cloth for rubbing (closer to 5th), the better the rubbing fastness of color. The wet rubbing fastness of color was evaluated in accordance with the following criteria and in accordance with the degree of coloring of the white cotton cloth for rubbing after the rubbing test.

[0145] Wet rubbing fastness of color 3rd or more “O” good wet rubbing fastness of color

[0146] Wet rubbing fastness of color less than 3rd “X” poor wet rubbing fastness of color

[0147] (Texture)

[0148] The unused printed object was folded along the warp direction (lengthwise direction), and the distance between the lower fabric and the upper fabric at the fold (loop height) was measured. The measured loop height of the unused printed object was set as the loop height before printing. Next, the region in which the solid image of the evaluation printed object was formed was folded along the warp direction (lengthwise direction), and the loop height was measured. The measured loop height of the evaluation printed object was set as the loop height after printing. The loop height change rate before and after printing was calculated according to the formula "loop height change rate = 100 x loop height after printing / loop height before printing" (unit: %). The lower the change rate of the loop height, the less the printed object becomes hard and swollen after printing, and thus it is indicated that the deterioration of the tactile sensation of the printed object is suppressed. The evaluation criteria are described below.

[0149] Less than 130% "O" texture change is small and good

[0150] 130% or more "X" texture becomes hard and is poor

[0151] (Washing color fastness)

[0152] The evaluation printed object on which the printing was performed was treated using a washing color fastness tester (1 aunder-ometer) (washing tester) according to the A-2 method described in JIS L-0844:2011 (Test method for color fastness to washing). Then, rinsing, dehydration, and drying were performed, and the degree of color change and fading of the evaluation printed object was determined according to the "determination criteria for color change and fading".

[0153] The evaluation criteria are described below.

[0154] Washing color fastness (color change and fading) 3-4 or more "O" washing color fastness is good

[0155] Washing color fastness (color change and fading) less than 3-4 "X" washing color fastness is poor

[0156] The results of the above evaluation test were summarized in Table 2.

[0157] Table 2

[0158]

[0159] (Investigation)

[0160] It was confirmed from the results of Table 2 that: by using the treatment liquid of the present application, a printed matter having good colorability (image density) and excellent wet rubbing color fastness, texture, and wash color fastness can be obtained. It was also known that: particularly when the treatment liquid of Examples 5 to 7 and 9 containing a metal salt as well was used, a printed matter having very excellent wash color fastness can be obtained. Furthermore, it was known from the results of Examples 3 and 8 that: when the content of the organic acid salt is 15% by weight or less, the wet rubbing color fastness is more excellent. Furthermore, it was known from the results of Examples 2 and 10 that: when the content of the organic acid salt is more than the content of the cationic polymer, the image density is improved. Furthermore, it was known from the results of Examples 6 and 9 that: when the content of the organic acid salt is more than the content of the metal salt, the image density is improved.

[0161] Furthermore, it was also confirmed from the results of Examples 11 to 14 that: in the case where magnesium acetate is used as the organic acid salt, as long as its content is a little more (around 12 to 15% by weight) than the total amount of the treatment liquid, the wash color fastness is very excellent even if the metal salt is not contained.

[0162] On the other hand, it was shown that: in the case where the treatment liquid of Comparative Examples 1 to 3 containing the water-soluble cationic polymer in an amount of 10% by weight or more was used, sufficient wet rubbing color fastness could not be obtained. Furthermore, in Comparative Examples 4 to 5 using the treatment liquid not containing the organic acid salt and Comparative Example 6 using the treatment liquid not containing the water-soluble cationic polymer, results of poor image density were obtained. Furthermore, in Comparative Example 6, results of insufficient wash color fastness were obtained.

[0163] Explanation of symbols

[0164] 1 treatment head

[0165] 2 recording head

[0166] 2a first recording head

[0167] 2b second recording head

[0168] 2c third recording head

[0169] 2d fourth recording head

[0170] 3 loading table

[0171] 10 inkjet printing device

[0172] P printed matter

Claims

1. A treatment liquid for inkjet, characterized by contains: a water-soluble cationic polymer and an organic acid salt and a metal salt, wherein, the content of the water-soluble cationic polymer is 0.1% by weight or more and less than 10% by weight relative to the total amount of the treatment liquid, the metal salt is a metal salt selected from the group consisting of calcium acetate, aluminum acetate, calcium carbonate, calcium nitrate, calcium chloride, calcium sulfate, calcium hydroxide, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, and copper nitrate, the content of the organic acid salt is more than the content of the metal salt.

2. The treatment liquid for inkjet according to claim 1, characterized in that, the content of the organic acid salt is 0.1 to 20% by weight relative to the total amount of the treatment liquid.

3. The treatment liquid for inkjet according to claim 1, characterized in that, the content of the organic acid salt is more than the content of the water-soluble cationic polymer.

4. The treatment liquid for inkjet according to claim 3, characterized in that, the content of the organic acid salt is 1 to 15% by weight relative to the total amount of the treatment liquid.

5. The treatment liquid for inkjet according to claim 1, characterized in that, the content of the metal salt is 0.1 to 5% by weight relative to the total amount of the treatment liquid, and the content of the organic acid salt is 1 to 15% by weight relative to the total amount of the treatment liquid.

6. The treatment liquid for inkjet according to claim 1, characterized in that, the organic acid salt is an organic acid magnesium salt.

7. The treatment liquid for inkjet according to claim 6, characterized in that, the content of the organic acid magnesium salt is 5 to 11% by weight relative to the total amount of the treatment liquid.

8. The treatment liquid for inkjet according to claim 6, characterized in that, the content of the organic acid magnesium salt is 12 to 15% by weight relative to the total amount of the treatment liquid.

9. The treatment liquid for inkjet according to any one of claims 1 to 8, characterized in that, is used for printing.

10. An inkjet printing apparatus characterized by comprising at least includes: a treatment head that ejects a treatment liquid to at least an image forming region of a print target object; a recording head that ejects an ink to the image forming region of the print target object; and a stage for conveying the print target object, wherein, the treatment liquid ejected from the treatment head is the treatment liquid for inkjet according to any one of claims 1 to 9.

Images