Inkjet printing pretreatment method and inkjet printing method

Abstract

To provide a simpler pretreatment method for inkjet printing which uses an inkjet system for applying a pretreatment liquid.SOLUTION: A pretreatment method for inkjet printing includes: the step (A) of applying a pretreatment liquid (a) containing an ink aggregation agent to an image formation region of a fabric by inkjet system; and the step (B) of applying a pretreatment liquid (b) containing an ink aggregation agent to an outer peripheral region of the image formation region of the fabric by inkjet system.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a pretreatment method for inkjet printing and an inkjet printing method.

Background Art

[0002] As a method of printing an image such as characters, pictures, patterns, etc. on fabrics such as woven fabrics, knitted fabrics, non-woven fabrics, etc., in addition to the screen printing method and the roller printing method, an inkjet printing method using an inkjet printer has attracted attention.

[0003] In the inkjet printing method, since ink is directly applied to the fabric based on the signal of the image data to form an image, it is possible to manufacture a printed matter with high efficiency from the viewpoints of the amount of ink used and the time required for printing. In the inkjet printing method, prior to the application of the ink, a method of applying a pretreatment liquid containing an ink aggregating agent or the like has been widely studied. For example, Patent Document 1 describes a pretreatment method in which a pretreatment liquid containing a metal salt such as calcium nitrate and an anionic resin is applied with a roller and dried.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] According to the method described in Patent Document 1, it is possible to obtain a printed matter having a white image excellent in whiteness and the like as compared with the conventional method. However, in the method described in Patent Document 1, pretreatment is performed by immersing the fabric in the pretreatment liquid or applying the pretreatment liquid with a roller or the like. A large amount of pretreatment liquid is required compared to the size of the formed image, and a drying time is also required. Therefore, a relatively large-scale pretreatment process has been required industrially.

[0006] One of the problems to be solved by the present disclosure is to provide a simpler pretreatment method for inkjet printing using an inkjet method for applying a pretreatment liquid.

Means for Solving the Problems

[0007] One embodiment of the present disclosure relates to a pretreatment method for inkjet printing, which includes a step (A) of applying a pretreatment liquid (a) containing an ink aggregating agent to an image forming region of a cloth by an inkjet method, and a step (B) of applying a pretreatment liquid (b) containing an ink aggregating agent to an outer peripheral region of the image forming region of the cloth by an inkjet method.

Effects of the Invention

[0008] According to the present disclosure, it is possible to provide a simpler pretreatment method for inkjet printing using an inkjet method for applying a pretreatment liquid.

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described in detail, but it goes without saying that the present disclosure is not limited to these embodiments, and various modifications and changes may be made.

[0010] A pretreatment method for inkjet printing which is one embodiment (hereinafter sometimes referred to as "pretreatment method") is a pretreatment method for inkjet printing, which includes a step (A) of applying a pretreatment liquid (a) containing an ink aggregating agent to an image forming region of a cloth by an inkjet method, and a step (B) of applying a pretreatment liquid (b) containing an ink aggregating agent to an outer peripheral region of the image forming region of the cloth by an inkjet method. According to this pretreatment method, a simpler pretreatment using an inkjet method becomes possible. Further, according to this pretreatment method, a simpler pretreatment becomes possible, and the image quality in inkjet printing can be improved.

[0011] In addition, in one embodiment, by dividing the application of the pretreatment liquid into two steps, the ink aggregability can be appropriately adjusted in each of the area where the pretreatment liquid (a) is applied in step (A) (hereinafter sometimes referred to as "area (a)") and the area where the pretreatment liquid (b) is applied in step (B) (hereinafter sometimes referred to as "area (b)"). As a result, appropriate pretreatment can be performed according to the type of fabric, the type of ink used for image formation, the complexity of the image shape, etc., and the image quality can be effectively improved. The pretreatment method of one embodiment is particularly effective in suppressing bleeding at the contour of the image.

[0012] Regarding the pretreatment liquid (a), the ink aggregating agent contained in the pretreatment liquid (a) is not particularly limited, and various types can be used. Also, one type of ink aggregating agent may be used alone, or two or more types may be used in combination.

[0013] Specific examples of the ink aggregating agent include, for example, metal salts, cationic polymers, organic acids, and the like.

[0014] Examples of the metal salt include metal salts composed of metal ions and anions. Examples of the metal ions include monovalent metal ions such as Na + , K + ; divalent metal ions such as Ca 2+ , Mg 2+ , Cu 2+ , Ni 2+ , Zn 2+ , Ba 2+ ; and the like. Examples of the anions include Cl - , NO3 - , CH3COO - , I - , Br - , ClO3 - ; and the like. Specific examples of the polyvalent metal salts include calcium chloride, calcium nitrate, magnesium nitrate, copper nitrate, calcium acetate, magnesium acetate, and the like. The metal salts may be used alone or in combination of two or more.

[0015] Examples of the cationic polymer include polyallylamine, polyallylamine sulfate, polyallylamine hydrochloride, allylamine diallylamine copolymer, allylamine diallylamine copolymer sulfate, allylamine diallylamine copolymer hydrochloride, allylamine dimethylallylamine copolymer, allylamine dimethylallylamine copolymer sulfate, allylamine dimethylallylamine copolymer hydrochloride, diallylamine, diallylamine sulfate, diallylamine hydrochloride, methyldiallylamine amide, methyldiallylamine amide sulfate, methyldiallylamine amide hydrochloride, diallylamine sulfur dioxide copolymer, diallylamine sulfur dioxide copolymer sulfate, diallylamine sulfur dioxide copolymer hydrochloride, methyldiallylamine sulfur dioxide copolymer, methyldiallylamine sulfur dioxide copolymer sulfate, methyldiallylamine sulfur dioxide copolymer hydrochloride, polydimethyldiallylammonium chloride, and the like. The cationic polymer may be used alone or in combination of two or more kinds.

[0016] Examples of the organic acid include formic acid, acetic acid, lactic acid, oxalic acid, citric acid, malic acid, ascorbic acid, and the like. The organic acid may be used alone or in combination of two or more kinds.

[0017] Among these, metal salts are preferred because of their excellent ink aggregating properties, and polyvalent metal salts formed from polyvalent metal ions and anions are more preferred.

[0018] In the pretreatment liquid (a), the proportion of the metal salt in the ink aggregating agent is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. Further, 100% by mass of the ink aggregating agent may be the metal salt. Furthermore, the proportion of the polyvalent metal salt in the ink aggregating agent is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. Further, 100% by mass of the ink aggregating agent may be the polyvalent metal salt.

[0019] The content of the ink flocculant in the pretreatment liquid (a) is appropriately adjusted according to the type of the ink flocculant, the composition of the ink applied to the cloth after the pretreatment liquid, etc. For example, it may be 1% by mass or more, may be 10% by mass or more, and may be 15% by mass or more with respect to the total amount of the pretreatment liquid (a). Also, it may be 50% by mass or less, may be 45% by mass or less, and may be 40% by mass or less with respect to the total amount of the pretreatment liquid. The content of the ink flocculant with respect to the total amount of the pretreatment liquid (a) may be, for example, in the range of 1 to 50% by mass.

[0020] The pretreatment liquid (a) is preferably aqueous and contains water as a solvent. As the water, those generally used in the field of aqueous inks can be used without particular limitation. For example, tap water, ion-exchanged water, deionized water, etc. can be mentioned. The content of water in the pretreatment agent (a) is appropriately adjusted according to the desired performance, viscosity, etc. For example, it may be in the range of 50 to 90% by mass.

[0021] The pretreatment liquid (a) may contain other components other than the ink flocculant and water. Examples of the other components include water-soluble organic solvents, pH adjusters, surfactants, dispersants, fixing agents, preservatives, etc.

[0022] As the water-soluble organic solvent, those generally used in the field of aqueous inks can be used without particular limitation. The water-soluble organic solvent may be used alone or in combination of two or more. Among them, a water-soluble organic solvent that is liquid at room temperature and can be uniformly mixed with the same volume of water at 1 atm and 20°C is preferred. Examples of such water-soluble organic solvents include lower alcohol compounds such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, 2-methyl-2-propanol; glycol compounds such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol; glycerin compounds such as glycerin, diglycerin, triglycerin, polyglycerin; acetin compounds such as monoacetin, diacetin, triacetin; glycol ether compounds such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether; triethanolamine, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, β-thiodiglycol, sulfolane and the like. The boiling point of the water-soluble organic solvent may be, for example, 100°C or higher, or 150°C or higher.

[0023] The content of the water-soluble organic solvent in the pretreatment liquid (a) may be 50% by mass or less, may be 30% by mass or less, or may be 10% by mass or less. Also, the content of the water-soluble organic solvent in the pretreatment liquid (a) may be 0.1% by mass or more, may be 0.5% by mass or more, or may be 1% by mass or more. The content of the water-soluble organic solvent in the pretreatment liquid (a) may be, for example, in the range of 0.1 to 50% by mass.

[0024] Examples of the surfactant include anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. The surfactant may be either a low-molecular surfactant or a high-molecular surfactant. The surfactant may be used alone or in combination of two or more. Among them, nonionic surfactants are preferred. The HLB value of the surfactant is preferably 5 to 20, and more preferably 10 to 18.

[0025] Examples of the nonionic surfactant include ester-type surfactants such as glycerin fatty acid esters and sorbitan fatty acid esters; ether-type surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, and polyoxypropylene alkyl ethers; ether-ester-type surfactants such as polyoxyethylene sorbitan fatty acid esters; acetylene-based surfactants; silicone-based surfactants; fluorine-based surfactants, etc. Among them, acetylene-based surfactants such as acetylene glycol-based surfactants can be preferably used.

[0026] Examples of the acetylene-based surfactant include acetylene glycol-based surfactants, acetylene alcohol-based surfactants, and surfactants having an acetylene group.

[0027] As acetylene glycol-based surfactants, there are glycols having an acetylene group, preferably glycols having a symmetrical structure with the acetylene group located in the center, and may have a structure in which ethylene oxide is added to acetylene glycol. Examples of commercially available acetylene-based surfactants include, for example, the Surfynol series "Surfynol 104E", "Surfynol 104H", "Surfynol 420", "Surfynol 440", "Surfynol 465", "Surfynol 485", etc. manufactured by Evonik Industries, and the Orfin series "Orfin E1004", "Orfin E1010", "Orfin E1020", etc. manufactured by Nissin Chemical Industry Co., Ltd. (all are trade names).

[0028] As silicone-based surfactants, for example, polyether-modified silicone-based surfactants, alkyl·aralkyl co-modified silicone-based surfactants, acrylic silicone-based surfactants, etc. can be mentioned. Examples of commercially available silicone-based surfactants include, for example, "Silface SAG002", "Silface SAG503A", etc. manufactured by Nissin Chemical Industry Co., Ltd. (all are trade names).

[0029] In addition, as other nonionic surfactants, for example, polyoxyethylene alkyl ether-based surfactants such as the Emulgen series "Emulgen 102KG", "Emulgen 103", "Emulgen 104P", "Emulgen 105", "Emulgen 106", "Emulgen 108", "Emulgen 120", "Emulgen 147", "Emulgen 150", "Emulgen 220", "Emulgen 350", "Emulgen 404", "Emulgen 420", "Emulgen 705", "Emulgen 707", "Emulgen 709", "Emulgen 1108", "Emulgen 4085", "Emulgen 2025G", etc. manufactured by Kao Corporation can be mentioned (all are trade names).

[0030] The content of the surfactant in the pretreatment liquid (a) may be, for example, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more with respect to the total amount of the pretreatment liquid. Also, it may be 10% by mass or less, 5% by mass or less, or 3% by mass or less with respect to the total amount of the pretreatment liquid. The content of the surfactant in the pretreatment liquid (a) may be, for example, in the range of 0.01 to 10% by mass.

[0031] The production method of the pretreatment liquid (a) is not particularly limited and can be appropriately produced by known methods. As an example, for instance, all components are charged into a stirrer such as a three - one motor all at once or dividedly, and a method of dispersing or dissolving an ink flocculant and other optional components in water can be mentioned. After dispersion or dissolution, a filter such as a membrane filter may be used as desired.

[0032] The pH of the pretreatment liquid (a) is preferably 3 to 9, more preferably 4 to 8. The viscosity of the pretreatment liquid (a) preferably has a viscosity of 1 to 30 mPa·s at 23°C.

[0033] Regarding the pretreatment liquid (b), the ink flocculant contained in the pretreatment liquid (b) is not particularly limited, and various types can be used. Also, one type of ink flocculant may be used alone, or two or more types may be used in combination.

[0034] Specific examples of the ink flocculant include, for example, those exemplified as the ink flocculant that the pretreatment liquid (a) may contain. Among them, metal salts are preferred because of their excellent ink flocculability, and polyvalent metal salts formed from polyvalent metal ions and anions are more preferred.

[0035] In the pretreatment liquid (b), the proportion of the metal salt in the ink flocculant is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. Further, 100% by mass of the ink flocculant may be a metal salt. Furthermore, the proportion of the polyvalent metal salt in the ink flocculant is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. Also, 100% by mass of the ink flocculant may be a polyvalent metal salt.

[0036] The content of the ink flocculant in the pretreatment liquid (b) is appropriately adjusted according to the type of the ink flocculant, the composition of the ink applied to the cloth after the pretreatment liquid, etc. For example, it may be 1% by mass or more, may be 10% by mass or more, and may be 15% by mass or more with respect to the total amount of the pretreatment liquid (b). Also, it may be 50% by mass or less, may be 45% by mass or less, and may be 40% by mass or less with respect to the total amount of the pretreatment liquid. The content of the ink flocculant with respect to the total amount of the pretreatment liquid (b) may be, for example, in the range of 1 to 50% by mass.

[0037] The pretreatment liquid (b) is preferably aqueous containing water as a solvent. As the water, those generally used in the field of aqueous inks can be used without particular limitation. For example, tap water, ion-exchanged water, deionized water, etc. are mentioned. The content of water in the pretreatment agent (b) is appropriately adjusted according to the desired performance, viscosity, etc. For example, it may be in the range of 50 to 90% by mass.

[0038] The pretreatment liquid (b) may contain other components other than the ink flocculant and water. Examples of the other components include, for example, water-soluble organic solvents, pH adjusters, surfactants, dispersants, fixing agents, preservatives, etc. Specific examples of these are the same as those exemplified as what the pretreatment liquid (a) may contain.

[0039] Specific examples of the aqueous organic solvent contained in the pretreatment liquid (b) include, for example, those exemplified as the aqueous organic solvent that the pretreatment liquid (a) may contain. The water-soluble organic solvent may be used alone or in combination of two or more. The content of the water-soluble organic solvent in the pretreatment liquid (b) may be 50% by mass or less, may be 30% by mass or less, or may be 10% by mass or less. Also, the content of the water-soluble organic solvent in the pretreatment liquid (b) may be 0.1% by mass or more, may be 0.5% by mass or more, or may be 1% by mass or more. The content of the water-soluble organic solvent in the pretreatment liquid (b) may be, for example, in the range of 0.1 to 50% by mass.

[0040] Specific examples of the surfactant contained in the pretreatment liquid (b) include, for example, those exemplified as the surfactant that the pretreatment liquid (a) may contain. The surfactant may be used alone or in combination of two or more. Among them, nonionic surfactants are preferred, and acetylene-based surfactants such as acetylene glycol-based surfactants are more preferred. The HLB value of the surfactant is preferably 5 to 20, and more preferably 10 to 18.

[0041] The content of the surfactant in the pretreatment liquid (b) may be, for example, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more based on the total amount of the pretreatment liquid. Also, it may be 10% by mass or less, 5% by mass or less, or 3% by mass or less based on the total amount of the pretreatment liquid. The content of the surfactant in the pretreatment liquid (b) may be, for example, in the range of 0.01 to 10% by mass.

[0042] The production method of the pretreatment liquid (b) is not particularly limited, and it can be produced by the same method as the pretreatment liquid (a).

[0043] The pH of the pretreatment liquid (b) is preferably 3 to 9, and more preferably 4 to 8. The viscosity of the pretreatment liquid (b) preferably has a viscosity of 1 to 30 mPa·s at 23°C.

[0044] The pretreatment liquid (a) and the pretreatment liquid (b) may be the same, or one or more conditions such as the type of ink flocculant, the concentration of the ink flocculant, and the presence or absence of other components may be different from each other. Among them, it is preferable that the ink flocculant contained in the pretreatment liquid (a) is a metal salt, and the ink flocculant contained in the pretreatment liquid (b) is a metal salt.

[0045] Step (A) is a step of applying a pretreatment liquid (a) containing an ink flocculant to the image forming area of the cloth by an inkjet method. Examples of the fibers constituting the cloth include natural fibers such as cotton, silk, wool, and hemp; chemical fibers such as polyester, acrylic, polyurethane, nylon, rayon, cupra, and acetate; or blended fibers thereof. Examples of the type of fabric include woven fabric, knitted fabric, or non-woven fabric.

[0046] The image forming area of the cloth is the area where ink is applied to form an image. The type of inkjet method is not particularly limited, and any method such as a piezo method, an electrostatic method, or a thermal method may be used. The application of the pretreatment liquid (a) by the inkjet method can be performed, for example, by using a general inkjet printer, discharging droplets of the pretreatment liquid (a) from an inkjet head based on a digital signal, and attaching the discharged droplets to the cloth. Depending on the printing accuracy of the inkjet printer, there may be a slight deviation between the image forming area and the application area (area (a)) of the pretreatment liquid (a). In the present disclosure, such a deviation caused by the printing accuracy of the inkjet printer is allowed. Generally, the deviation due to the printing accuracy of the inkjet printer is in the range of 2 to 3 dots.

[0047] The application amount of the pretreatment liquid (a) is appropriately adjusted according to the type of ink flocculant contained in the pretreatment liquid (a), the concentration of the ink flocculant, the type of cloth, etc. For example, it may be 10 g / m 2 or more, and may be 20 g / m 2 or more, and may be 30 g / m 2 or more. Also, it may be 100 g / m 2 or less, and may be 75 g / m2 It may also be as follows, 50 g / m 2 It may also be as follows. The application amount of the pretreatment liquid (a) may be, for example, in the range of 10 to 100 g / m 2 It may be in the range. The application amount of the pretreatment liquid (a) can be controlled as the discharge amount by an inkjet printer.

[0048] Step (B) is a step of applying a pretreatment liquid (b) containing an ink aggregating agent to the outer peripheral region of the image forming region of the cloth by an inkjet method. The outer peripheral region of the image forming region is a region that is adjacent to the outside of the image forming region and surrounds the image forming region.

[0049] In one embodiment, the width of the outer peripheral region is a value measured by the following method. Draw a tangent line to the edge of the image forming region. Draw a perpendicular line passing through the contact point with respect to the tangent line and extend it to the outer edge of the outer peripheral region. The distance between (the contact point) - (the intersection point of the perpendicular line and the outer edge of the outer peripheral region) is defined as the width of the outer peripheral region.

[0050] The width of the outer peripheral region is appropriately adjusted according to the size of the cloth, the size of the formed image, the complexity of the formed image, etc., but it is preferably narrow from the viewpoint of productivity. The width of the outer peripheral region may be constant throughout the region or may vary depending on the location. The width of the outer peripheral region may be, for example, 0.03 mm or more, 0.08 mm or more, or 0.1 mm or more. Also, it may be 0.5 mm or less, 0.3 mm or less, or 0.2 mm or less. The width of the outer peripheral region may be, for example, in the range of 0.01 to 0.5 mm.

[0051] Since the treatment liquid (b) is applied by an inkjet method, the width of the outer peripheral region can also be expressed in terms of the number of dots. The size of the dots varies depending on the resolution of the inkjet printer when applying the pretreatment liquid (b). For example, when the resolution is 600 dpi, one dot is approximately 0.042 mm. When the resolution of the inkjet printer for applying the treatment liquid (b) is 600 dpi, the width of the outer peripheral region may be, for example, 1 dot or more, 2 dots or more, or 3 dots or more. Also, it may be 9 dots or less, 7 dots or less, or 5 dots or less. When the resolution of the inkjet printer for applying the treatment liquid (b) is 600 dpi, the width of the outer peripheral region may be, for example, in the range of 1 to 9 dots.

[0052] The application of the pretreatment liquid (b) by the inkjet method can be carried out using a general inkjet printer, similar to the pretreatment liquid (a). As described above, depending on the printing accuracy of the inkjet printer, there may be a slight deviation between the desired outer peripheral region and the region where the pretreatment liquid (b) is actually applied (region (b)). Therefore, for example, there is a possibility that a part of region (b) overlaps with a part of region (a), or a region where no pretreatment liquid is applied may occur between region (a) and region (b). However, in the present disclosure, such deviations due to the printing accuracy of the inkjet printer are considered acceptable.

[0053] The application amount of the pretreatment liquid (b) is appropriately adjusted according to the type of ink aggregating agent contained in the pretreatment liquid (b), the concentration of the ink aggregating agent, the type of cloth, etc. For example, it may be 10 g / m 2 or more, 20 g / m 2 or more, or 30 g / m 2 or more. Also, it may be 100 g / m 2 or less, 75 g / m 2 or less, or 50 g / m 2 or less. The application amount of the pretreatment liquid (b) is, for example, 10 to 100 g / m 2It may also be within the range. The application amount of the pretreatment liquid (b) can be controlled as the ejection amount by an inkjet printer.

[0054] Process (A) and process (B) may be carried out in either order. That is, either a method of carrying out process (A) first and then process (B), or a method of carrying out process (B) first and then process (A) may be used. Also, if desired, a drying process may be provided either after process (A) or after process (B) or both. From the viewpoint of the efficiency of pretreatment, it is preferable to carry out the said process (B) in a wet-on-wet manner after process (A). Note that the wet-on-wet method refers to applying the next liquid without providing a drying process after the application of a liquid.

[0055] In process (A) and process (B), in regions (a) and (b), it is preferable to apply each pretreatment liquid so that the ink aggregability in both regions is equal, or the ink aggregability in region (a) is higher than the ink aggregability in region (b). Thereby, the image quality of the image can be effectively improved, and in particular, bleeding at the contour portion of the image can be effectively suppressed.

[0056] The adjustment of the ink aggregability in each region can be carried out, for example, by adjusting the type of ink aggregating agent contained in the pretreatment liquid, the concentration of the ink aggregating agent, the application amount of the pretreatment liquid, etc. Specific examples of the method of making the ink aggregability in region (a) higher than the ink aggregability in region (b) include, for example, using an ink aggregating agent with higher ink aggregability for the pretreatment liquid (a), increasing the ink aggregating agent concentration of the pretreatment liquid (a), increasing the application amount of the pretreatment liquid (a), and the like.

[0057] An image can be formed in the image forming region after the pretreatment. The method of forming the said image is not particularly limited, but it is preferable to form an image by applying ink by an inkjet method. Also, the ink is preferably aqueous. The color of the ink applied subsequent to the pretreatment is not particularly limited, and it may be either white ink or non-white ink.

[0058] The physical properties of the ink applied following the pretreatment are not particularly limited. For example, when the ink is applied by an inkjet method, general inkjet inks can be widely used. Among them, when the ink is an aqueous ink, since image formation with more excellent color development properties becomes possible, it is preferable to use an ink having a charge density of 30 μeq / g or more. The upper limit value of the charge density is not particularly limited, and may be, for example, 300 μeq / g or less, may be 100 μeq / g or less, or may be 50 μeq / g or less. The charge density of the ink applied following the pretreatment liquid may be, for example, in the range of 30 to 300 μeq / g.

[0059] In the present disclosure, the charge density of the aqueous ink is the charge density measured by the streaming potential method, and is the amount of charge per unit amount of solid content in the ink (unit: μeq / g). Specifically, it is a value measured by the following method. Note that the solid content in the aqueous ink refers to components other than water and water-soluble solvents in the aqueous ink. 1. Add water to the aqueous ink and dilute it so that the volume becomes 100 times. 2. Titrate the diluted solution with a 0.0025N diallyldimethylammonium poly-chloride solution, and take the end point of titration when the streaming potential of the diluted solution becomes 0 V. For the measurement of the streaming potential, a colloid particle charge meter ("Model CAS" manufactured by AFG ANAYTIC GmbH) is used. 3. Determine the total charge amount of the diluted solution from the amount of the 0.0025N diallyldimethylammonium poly-chloride solution used up to the end point of titration. 5. The value obtained by dividing the total charge amount of the diluted solution by the amount of solid content of the aqueous ink contained in the diluted solution is defined as the charge density (μeq / g) of the aqueous ink.

[0060] When the fabric is a low-luminance color such as black, image formation with better color development can be achieved. Therefore, it is preferable to apply white ink after the pre-treatment and then apply non-white ink on top of it. At this time, the methods of applying the white ink and the non-white ink are not particularly limited, but it is preferable to apply both by an inkjet method. Also, after applying the white ink, it is preferable to apply the non-white ink in a wet-on-wet manner.

[0061] Hereinafter, as an example of an embodiment of the present disclosure, the case where the ink applied subsequent to the pre-treatment is white ink and non-white ink is further applied on top of it will be described in detail. As described above, such an embodiment can be particularly preferably used when it is more difficult to form an image with high color development, such as when the fabric is a low-luminance color such as black.

[0062] As described above, it is preferable that the charge density of the ink applied subsequent to the pre-treatment is 30 μeq / g or more. In particular, when the ink is white ink, a charge density of 30 μeq / g or more can improve both the concealability of the white image and the density of the non-white image formed thereon.

[0063] The white ink contains a white pigment as a coloring material. One type of white pigment may be used alone, or two or more types may be used in combination. Examples of the white pigment include white inorganic pigments such as titanium oxide, zinc white, zinc sulfide, antimony oxide, and zirconium oxide. Among them, from the viewpoint of concealability, it is preferable to use titanium oxide. The average particle diameter of titanium oxide is not particularly limited, but it may be in the range of 100 to 600 nm, for example. In the white ink, a pigment dispersion in which the pigment is previously dispersed with a pigment dispersant may be used, or a pigment dispersion dispersed with a pigment dispersant described later may be used.

[0064] The content of the white pigment in the white ink is not particularly limited and can be used in a range similar to that of general white inks. For example, it may be 1% by mass or more, 3% by mass or more, or 5% by mass or more with respect to the total amount of the white ink. Also, it may be 30% by mass or less, 20% by mass or less, or 15% by mass or less. The content of the white pigment with respect to the total amount of the white ink may be, for example, in the range of 1 to 30% by mass.

[0065] In order to stably disperse the white pigment in the white ink, various pigment dispersants may be used. One type of pigment dispersant may be used alone, or two or more types may be used in combination. Examples of the pigment dispersant include polymer dispersants, surfactant-type dispersants, and the like.

[0066] Examples of the polymer dispersant include, as commercially available products, the TEGO Dispers series "TEGO Dispers 740W", "TEGO Dispers 750W", "TEGO Dispers 755W", "TEGO Dispers 757W", "TEGO Dispers 760W", etc. manufactured by EVONIK; the Solsperse series "Solsperse 20000", "Solsperse 27000", "Solsperse 41000", "Solsperse 41090", "Solsperse 43000", "Solsperse 44000", "Solsperse 46000", etc. manufactured by Lubrizol Japan Co., Ltd.; the Joncryl series "Joncryl 57", "Joncryl 60", "Joncryl 62", "Joncryl 63", "Joncryl 71", "Joncryl 501", etc. manufactured by BASF Japan Ltd.; "DISPERBYK-102", "DISPERBYK-185", "DISPERBYK-190", "DISPERBYK-193", "DISPERBYK-199", etc. manufactured by BYK-Chemie Japan Co., Ltd.; "Polyvinylpyrrolidone K-30", "Polyvinylpyrrolidone K-90", etc. manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (all are trade names).

[0067] Examples of surfactant-type dispersants include, as commercially available products, anionic surfactants such as the Demol series “Demol P,” “Demol EP,” “Demol N,” “Demol RN,” “Demol NL,” “Demol RNL,” “Demol T-45,” etc. manufactured by Kao Corporation, and nonionic surfactants such as the Emulgen series “Emulgen A-60,” “Emulgen A-90,” “Emulgen A-500,” “Emulgen B-40,” “Emulgen L-40,” “Emulgen 420,” etc. manufactured by Kao Corporation (all are trade names).

[0068] When using a pigment dispersant, the blending amount in the white ink is appropriately adjusted according to the type of white pigment and pigment dispersant, etc. For example, it may be in the range of 0.5 to 50 parts by mass with respect to 100 parts by mass of the pigment.

[0069] The white ink preferably contains a resin. One type of resin may be used alone, or two or more types may be used in combination. The content of the resin in the white ink is appropriately adjusted according to the desired viscosity, etc. For example, it may be 5% by mass or more, 8% by mass or more, or 10% by mass or more. Also, it may be 30% by mass or less, 25% by mass or less, or 20% by mass or less. The content of the resin in the white ink may be, for example, in the range of 5 to 30% by mass.

[0070] As the type of resin, those capable of forming a transparent coating film are preferred because they can become white inks with better color development properties. Specific examples of the resin include, for example, conjugated diene resins such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, vinyl chloride-vinyl acetate copolymer; acrylic resins such as polymers of acrylic acid ester and methacrylic acid ester, or copolymers of these with styrene, etc.; vinyl resins such as ethylene-vinyl acetate copolymer; functional group-modified resins obtained by modifying these various resins with monomers having functional groups such as carboxy group; melamine resin; urea resin; polyurethane resin; polyester resin; polyolefin resin; silicone resin; polyvinyl butyral resin; alkyd resin, etc. Among them, polyurethane resin is preferred because it can become a white ink with excellent hiding properties of the white image and high followability of the white image to the fabric.

[0071] When the white ink is aqueous, the resin is preferably resin particles dispersible in an aqueous solvent. In particular, those capable of forming an oil-in-water (O / W) type emulsion without dissolving in water in water are preferred. The resin may be formulated as an aqueous dispersion of resin particles during the production of the white ink.

[0072] When the resin is resin particles dispersible in an aqueous solvent, like self-emulsifying type resins, those in which the functional groups possessed by the resin are present on the surface of the resin particles may be used, or those subjected to surface treatment such as attaching a dispersant to the surface of the resin particles may also be used. The resin particles may be any of anionic, cationic, nonionic, or amphoteric, but anionic or nonionic is preferred, and anionic is more preferred.

[0073] The anionic resin particles may be those in which the anionic functional groups possessed by the resin are present on the surface of the resin particles, like self-emulsifying type resins, or those subjected to surface treatment such as attaching an anionic dispersant to the surface of the resin particles. Representative examples of the anionic functional groups include carboxy group, sulfo group, sulfino group, sulfate ester group, phosphate group, phosphate ester group, phosphite group, phosphite ester group, etc. Examples of the anionic dispersant include anionic surfactants, etc.

[0074] The nonionic resin particles may be those in which nonionic functional groups of the resin are present on the surface of the resin particles, such as self-emulsifying resins, or those subjected to surface treatment such as attaching a nonionic dispersant to the surface of the resin particles. Representative examples of the nonionic functional groups include polyoxyalkylene glycol groups and hydroxy groups. Examples of the nonionic dispersant include nonionic surfactants.

[0075] The average particle diameter of the resin particles is not particularly limited, and may be, for example, in the range of 30 to 300 nm. In the present disclosure, the average particle diameter of the resin particles is the volume-based median diameter in the particle size distribution measured by the dynamic light scattering method. The particle size distribution of the resin particles can be measured at 25 °C using a measurement sample obtained by diluting a dispersion of the resin particles with water so that the resin particle concentration becomes 0.5% by mass. As the dynamic light scattering type particle diameter distribution measuring device, for example, "nano Partica SZ-100" (manufactured by Horiba, Ltd.) can be used.

[0076] Note that the average particle diameter of the resin particles is preferably measured in the state of the resin particle dispersion as a raw material before preparing the ink, because the influence of the coloring material can be excluded, and the measured value can be used as the average particle diameter of the resin particles.

[0077] Examples of commercially available aqueous dispersions of resin particles include polyurethane dispersions "DAOTAN" series (e.g., "DAOTAN TW6450", "DAOTAN TW6460", "DAOTAN TW6490", "DAOTAN VTW1262", etc.) manufactured by Daicel Ornex Co., Ltd., "Impranil" series (e.g., "Impranil DLP", "Impranil DLP-R", "Impranil DLV", "Impranil DLI", "Impranil 1016", "Impranil 1116", "Impranil DLS", "Impranil DL1537", "Impranil DL1554", "Impranil DL1380", "Impranil LP CGL 105", "Impranil DLN-SD", "Impranil LP DSB 1069", "Impranil DLN-W50", etc.) manufactured by Sumika Covestro Urethane Co., Ltd., "Superflex" series (e.g., "Superflex 420", "Superflex 150HS", "Superflex 460", "Superflex 470", "Superflex E2000", "Superflex 740", "Superflex 500M", "Superflex 300", etc.) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Elel" series (e.g., "Elel KT9204", "Elel KT8803", etc.) manufactured by Unitika Ltd., "NeoRez" series (e.g., "NeoRez R-966", "NeoRez R-4000", etc.) manufactured by DSM, "AQUACER" series (e.g., "AQUACER507", etc.) manufactured by BYK, "Mobinil" series (e.g., "Mobinil 6750", "Mobinil 6751D", "Mobinil 6763", "Mobinil 6770", "Mobinil 6775", etc.) manufactured by Nippon Coating Resin Co., Ltd. (all are trade names).

[0078] The white ink may be aqueous. When it is an aqueous ink, examples of the water contained in the white ink include ion-exchanged water, distilled water, ultrapure water, etc. The ratio of water to the total amount of the white ink is appropriately adjusted according to the desired viscosity, etc., and may be, for example, in the range of 50 to 90% by mass.

[0079] The white ink may contain a white pigment, a resin, and other components other than water. Examples of the other components include, for example, water-soluble organic solvents, pH adjusters, surfactants, dispersants, fixing agents, preservatives, and the like. Specific examples thereof are those exemplified as those that the pretreatment liquid (a) may contain.

[0080] The white ink preferably contains an aqueous organic solvent. Specific examples of the aqueous organic solvent contained in the white ink include, for example, those exemplified as the aqueous organic solvents that the pretreatment liquid (a) may contain. The water-soluble organic solvent may be used alone or in combination of two or more. The content of the water-soluble organic solvent in the white ink may be 50% by mass or less, may be 30% by mass or less, or may be 10% by mass or less. Also, the content of the water-soluble organic solvent in the white ink may be 0.1% by mass, may be 0.5% by mass or more, or may be 1% by mass or more. The content of the water-soluble organic solvent in the pretreatment liquid (b) may be, for example, in the range of 0.1 to 50% by mass.

[0081] Specific examples of the surfactant contained in the white ink include, for example, those exemplified as the surfactants that the pretreatment liquid (a) may contain. The surfactant may be used alone or in combination of two or more. Among them, nonionic surfactants are preferred, and acetylene-based surfactants such as acetylene glycol-based surfactants are more preferred. The HLB value of the surfactant is preferably 5 to 20, and more preferably 10 to 18.

[0082] The content of the surfactant in the white ink may be, for example, 0.01% by mass or more, may be 0.05% by mass or more, or may be 0.1% by mass or more based on the total amount of the pretreatment liquid. Also, it may be 10% by mass or less, may be 5% by mass or less, or may be 3% by mass or less based on the total amount of the pretreatment liquid. The content of the surfactant in the white ink may be, for example, in the range of 0.01 to 10% by mass.

[0083] The method for manufacturing the white ink is not particularly limited, and it can be manufactured by a general method for manufacturing white ink. As an example, for instance, all components can be charged and dispersed into a stirrer such as a Three-One motor all at once or in portions, and if desired, the ink can be obtained by passing it through a filter such as a membrane filter.

[0084] From the viewpoint of the storage stability of the ink, the pH of the white ink may be, for example, in the range of 7.0 to 10.0. Also, from the viewpoint of inkjet ejection property, the viscosity of the white ink may be, for example, in the range where the viscosity at 23 °C is 1 to 30 mPa·s.

[0085] Regarding the non-white ink, in one embodiment, the non-white ink is not particularly limited, and a wide variety of inks can be used. In one embodiment, the non-white ink may be an aqueous inkjet ink. Also, the non-white ink may be used alone or in combination of two or more kinds.

[0086] The non-white ink contains a non-white colorant. The colorant may be used alone or in combination of two or more kinds. Examples of the colorant include various non-white pigments, for example, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, and lake pigments, and inorganic pigments such as carbon black and metal oxides can be used. Examples of azo pigments include soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments. Examples of phthalocyanine pigments include metal phthalocyanine pigments and metal-free phthalocyanine pigments. Examples of polycyclic pigments include quinacridone-based pigments, perylene-based pigments, perinone-based pigments, isoindoline-based pigments, isoindolinone-based pigments, dioxazine-based pigments, thioindigo-based pigments, anthraquinone-based pigments, quinophthalone-based pigments, metal complex pigments, and diketopyrrolopyrrole (DPP). Examples of carbon black include furnace carbon black, lamp black, acetylene black, and channel black.

[0087] From the viewpoints of ejection stability and storage stability, the average particle diameter of pigment particles in non-white ink may be 300 nm or less, may be 200 nm or less, or may be 150 nm or less as the volume-based average value in the particle size distribution measured by the dynamic light scattering method.

[0088] The non-white pigment may be a self-dispersible pigment or a microencapsulated pigment in which the pigment is coated with a resin. Further, in the non-white ink, a pigment dispersion in which the pigment is previously dispersed with a pigment dispersant may be used, or the pigment may be dispersed and used with a pigment dispersant described later.

[0089] The self-dispersible pigment is a pigment in which a hydrophilic functional group is introduced onto the surface of the pigment by chemical treatment or physical treatment. As the hydrophilic functional group to be introduced into the self-dispersible pigment, those having ionic properties are preferable, and by charging the pigment surface anionically or cationically, the pigment particles can be stably dispersed in water by electrostatic repulsive force. Examples of the anionic functional group include a carboxy group, a sulfo group, a sulfino group, a sulfate ester group, a phosphate group, a phosphate ester group, a phosphite group, a phosphite ester group, etc. Examples of the cationic functional group include a quaternary ammonium group, a quaternary phosphonium group, etc. These hydrophilic functional groups may be directly bonded to the pigment surface or may be bonded via another atomic group. Examples of the other atomic group include an alkylene group, a phenylene group, a naphthylene group, etc. Examples of the treatment method for the pigment surface include diazotization treatment, sulfonation treatment, hypochlorous acid treatment, humic acid treatment, vacuum plasma treatment, etc.

[0090] As self-dispersing pigments, for example, the "CAB-O-JET" series manufactured by Cabot Corporation ("CAB-O-JET200", "CAB-O-JET300", "CAB-O-JET250C", "CAB-O-JET260M", "CAB-O-JET270", "CAB-O-JET450C", "CAB-O-JET465M", etc.), the "BONJET" series manufactured by Orient Chemical Industries, Ltd. ("BONJET BLACK CW-1", "BONJET BLACK CW-2", "BONJET BLACK CW-3", "BONJET BLACK CW-4", etc.) can be preferably used (all are trade names).

[0091] Examples of commercially available pigment dispersions in which the pigment is pre-dispersed with a pigment dispersant include the HOSTAJET series manufactured by Clariant and the FUJI SP series manufactured by Fuji Pigment Co., Ltd.

[0092] The content of the non-white pigment in the non-white ink is not particularly limited and can be used in a range similar to that of general non-white inks. For example, it may be in the range of 1 to 10% by mass based on the total amount of the non-white ink.

[0093] In order to stably disperse the non-white pigment in the non-white ink, various pigment dispersants may be used. The pigment dispersant may be used alone or in combination of two or more. Examples of the pigment dispersant include those exemplified as the pigment dispersant that may be contained in the white ink.

[0094] When using a pigment dispersant, the blending amount in the non-white ink is appropriately adjusted according to the type of the non-white pigment and the pigment dispersant, etc., but for example, it may be in the range of 0.5 to 150 parts by mass with respect to 100 parts by mass of the non-white pigment.

[0095] The non-white ink preferably contains a resin. The resin may be used alone or in combination of two or more. The content of the resin in the non-white ink is appropriately adjusted according to the desired viscosity, etc., but for example, it may also be in the range of 3 to 30% by mass.

[0096] As the type of resin, those capable of forming a transparent coating film are preferred because they can be non-white inks with better color-developing properties. Specific examples of the resin include, for example, those exemplified as the resins that the white ink may contain.

[0097] The non-white ink may be aqueous. When it is an aqueous ink, examples of the water contained in the non-white ink include, for example, ion-exchanged water, distilled water, ultrapure water, etc. The ratio of water to the total amount of the non-white ink is appropriately adjusted according to the desired viscosity, etc., but may be, for example, in the range of 50 to 90% by mass.

[0098] The non-white ink may contain other components in addition to the white pigment, resin, and water. Examples of other components include, for example, water-soluble organic solvents, pH adjusters, surfactants, dispersants, fixing agents, preservatives, etc. Specific examples of these are those exemplified as those that the pretreatment liquid (a) may contain.

[0099] The non-white ink preferably contains an aqueous organic solvent. Specific examples of the aqueous organic solvent contained in the non-white ink include, for example, those exemplified as the aqueous organic solvents that the pretreatment liquid (a) may contain. The water-soluble organic solvent may be used alone or in combination of two or more. The content of the water-soluble organic solvent in the non-white ink may be, for example, in the range of 0.1 to 50% by mass.

[0100] The non-white ink preferably contains a surfactant. Specific examples of the surfactant contained in the non-white ink include, for example, those exemplified as the surfactants that the pretreatment liquid (a) may contain. The surfactant may be used alone or in combination of two or more. Among them, nonionic surfactants are preferred, and acetylene-based surfactants such as acetylene glycol-based surfactants are more preferred. The HLB value of the surfactant is preferably 5 to 20, and more preferably 10 to 18. The content of the surfactant in the non-white ink may be, for example, in the range of 0.01 to 10% by mass based on the total amount of the non-white ink.

[0101] The method for manufacturing the non-white ink is not particularly limited and can be manufactured by a general method for manufacturing non-white ink. As an example, for instance, all components are charged into a stirrer such as a three-one motor all at once or dividedly and dispersed, and if desired, the ink can be obtained by passing it through a filter such as a membrane filter.

[0102] From the viewpoint of the storage stability of the ink, the pH of the non-white ink may be, for example, in the range of 7.0 to 10.0. Also, from the viewpoint of inkjet ejection property, the viscosity of the non-white ink may be, for example, in the range of 1 to 30 mPa·s at 23°C.

[0103] The application of the white ink to the image formation area is preferably performed by an inkjet method in the same manner as the pretreatment liquid. The application of the white ink may be to a part or the whole of the image formation area, but it is preferably to the whole of the image formation area because an image with better color developability can be formed. The application of the white ink is preferably performed in a wet-on-wet method after the pretreatment. For example, it is preferable that the white ink is applied in a state where the remaining amount of the volatile component of the pretreatment liquid on the cloth is 90% by mass or more after the pretreatment. As the time, for example, the time from the end of the pretreatment to the application of the white ink is preferably 0.1 to 200 seconds.

[0104] The application amount of the white ink to the image formation area is appropriately adjusted according to the composition of the white ink, the desired image density, etc. For example, it may be in the range of 50 to 400 g / m 2 . When the white ink is applied by an inkjet method, the application amount can be controlled as the ejection amount by an inkjet printer.

[0105] Application of non-white ink to the image forming area is preferably performed by an inkjet method similar to that of white ink. The application of non-white ink may be performed on part or all of the image forming area. When the application of white ink is on part of the image forming area, non-white ink may be applied outside the area where white ink is applied. In terms of forming an image with better color development, the area where non-white ink is applied is preferably the same shape as the area where white ink is applied or within the area where white ink is applied. The application of non-white ink may be performed after a drying process after the application of white ink, or may be performed in a wet-on-wet method after the application of white ink. From the viewpoint of printing efficiency, it is preferable to apply non-white ink in a wet-on-wet method after the application of white ink. At this time, for example, it is preferable that non-white ink is applied in a state where the remaining amount of the volatile component of the white ink on the fabric is 90% by mass or more after the application of white ink. As for the time, for example, the time from the end of the application of white ink to the application of non-white ink is preferably 0.1 to 200 seconds.

[0106] The amount of non-white ink applied to the image forming area is appropriately adjusted according to the composition of the white ink, the desired image density, etc. For example, it may be in the range of 5 to 60 g / m 2 ². When applying non-white ink by an inkjet method, the application amount can be controlled as the ejection amount by an inkjet printer.

[0107] When all of process (A), process (B), the process of applying white ink, and the process of applying non-white ink are performed by an inkjet method, all processes may be performed using a single inkjet printer, or may be performed using a plurality of inkjet printers.

[0108] After the step of applying the non-white ink, a step of heat-treating the fabric may be provided. The heat treatment temperature can be appropriately adjusted according to the type of the fabric and the like. For example, it may be 100°C or higher, and may also be 150°C or higher. From the viewpoint of reducing damage to the fabric due to heat, the heat treatment temperature is preferably 200°C or lower. The heating method is not particularly limited. For example, a heat press, a roll heater, a hot air device, an infrared lamp heater, etc. can be used. The heat treatment time may be appropriately set according to the heating method, the heat treatment temperature, etc. For example, it may be in the range of 1 second to 10 minutes.

[0109] After the step of applying the non-white ink, a step of applying a post-treatment liquid may be provided. The application of the post-treatment liquid may be provided after the application of the non-white ink and before the heat treatment step, or may be provided after the heat treatment step. In the latter case, a heat treatment step may be provided again after the application of the post-treatment liquid.

[0110] Some embodiments of the present disclosure are shown below.

[0111] <1>A pretreatment method for inkjet printing, including step (A) of applying a pretreatment liquid (a) containing an ink flocculant to the image formation area of the fabric by an inkjet method, and step (B) of applying a pretreatment liquid (b) containing an ink flocculant to the outer peripheral area of the image formation area of the fabric by an inkjet method.

[0112] <2>The pretreatment method according to <1>, wherein the ink flocculant contained in the pretreatment liquid (a) is a metal salt, and the ink flocculant contained in the pretreatment liquid (b) is a metal salt.

[0113] <3>The pretreatment method according to <1> or <2>, wherein in step (B), the width of the outer peripheral area is in the range of 0.01 to 0.5 mm.

[0114] <4>The pretreatment method according to any one of <1> to <3>, wherein step (B) is performed in a wet-on-wet manner after step (A).

[0115] <5>After performing pretreatment by the pretreatment method according to any one of <1> to <4> above, an ink having a charge density of 30 μeq / g or more is applied by an inkjet method, an inkjet printing method.

[0116] <6>The application of the ink after pretreatment is performed by a wet-on-wet method, the inkjet printing method according to <5> above.

[0117] <7>The ink having a charge density of 30 μeq / g or more is a white ink, the inkjet printing method according to <5> above.

[0118] <8>After applying the white ink, further, a non-white ink is applied by an inkjet method, the inkjet printing method according to <7> above.

Example

[0119] Hereinafter, embodiments of the present disclosure will be described in detail by examples. The present disclosure is not limited to the following examples. In the following description, unless otherwise specified, “%” indicates “mass%”.

[0120] [Measurement of charge density] The charge density of the white ink and each raw material was measured by the following method. 1. Water was added to the measurement target and diluted so that the volume became 100 times. 2. The diluted solution was titrated with a 0.0025N diallyldimethylammonium poly chloride solution, and the titration end point was set when the streaming potential of the diluted solution became 0V. For the measurement of the streaming potential, a colloid particle charge meter (“Model CAS” manufactured by AFG ANAYTIC GmbH) was used. 3. The total charge amount of the diluted solution was determined from the amount of the 0.0025N diallyldimethylammonium poly chloride solution used up to the titration end point. 5. The value obtained by dividing the total charge amount of the diluted solution by the solid content of the measurement target contained in the diluted solution was defined as the charge density (μeq / g) of the aqueous ink. The solid content of the measurement target refers to components other than water and water-soluble solvents in the measurement target.

[0121] [Manufacture of Pretreatment Liquid] The raw materials were mixed at the compounding ratios shown in Table 1 and filtered through a cellulose acetate membrane filter with a pore size of 3 μm to obtain Pretreatment Liquids 1 and 2.

[0122] The details of the raw materials shown in Table 1 are as follows.

[0123] Calcium chloride: Manufactured by Fujifilm Wako Pure Chemical Corporation Lactic acid: 87 mass% aqueous solution, manufactured by Fujifilm Wako Pure Chemical Corporation Glycerin: Manufactured by Fujifilm Wako Pure Chemical Corporation Surfactant: "Orfin E1010" manufactured by Nissin Chemical Industry Co., Ltd., an acetylene-based surfactant

[0124]

Table 1

[0125] [Manufacture of White Pigment Dispersion] 500 g of white pigment, 20 g of pigment dispersant, and 480 g of ion-exchanged water were mixed. Using a bead mill ("DYNO-MILL KDL A Type" manufactured by Shinmaru Enterprises Corporation), dispersion treatment was carried out under the conditions of a filling rate of zirconia beads with a diameter of 0.5 mm of 80% and a residence time of 2 minutes to obtain a white pigment dispersion with a pigment content of 50 mass%.

[0126] The details of the raw materials of the white pigment dispersion are as follows.

[0127] White pigment: Titanium oxide "R62N" manufactured by Sakai Chemical Industry Co., Ltd., primary particle diameter 0.26 μm Pigment dispersant: "Demol EP" manufactured by Kao Corporation, a polycarboxylic acid type polymer surfactant, active ingredient 25 mass%

[0128] [Manufacture of White Ink] The raw materials were mixed at the compounding ratios shown in Table 2 and filtered through a cellulose acetate membrane filter with a pore size of 3 μm to obtain White Inks 1 and 2.

[0129] The details of the raw materials described in Table 2 are as follows.

[0130] White pigment dispersion: The one manufactured above, pigment content 50% by mass, charge density 21 μeq / g Resin particle dispersion 1: "DAOTAN TW6490 / 35WA" manufactured by Daicel Ornex Co., Ltd., aliphatic polyurethane resin, solid content 35% by mass, charge density 48 μeq / g Resin particle dispersion 2: "Mobinyl 6763" manufactured by Japan Coating Resin Co., Ltd., urethane resin, solid content 35% by mass, charge density 33 μeq / g Glycerin: Manufactured by Fujifilm Wako Pure Chemical Corporation Surfactant: "Orfin E1010" manufactured by Nissin Chemical Industry Co., Ltd., acetylene-based surfactant

[0131]

Table 2

[0132] Examples 1 and 2 and Comparative Example 1 Using the pretreatment liquid and white ink obtained above, printed fabrics were created according to the following procedure. The setting conditions for each item in the examples and comparative examples are shown in Table 3. Also, the bleeding in the contour part of the image and the concealability of the white image were evaluated for the obtained printed fabrics. The results are shown in Table 3.

[0133] As the fabric, a black polyester T-shirt (product name Glimmer) manufactured by Thoms Co., Ltd. was used.

[0134] For applying the pretreatment liquid and white ink, an inkjet printer "MMP-8130" manufactured by Mastermind Co., Ltd. was used (resolution 600 dpi).

[0135] [Manufacture of Printed Fabric] A 10 cm × 20 cm rectangular area on the cloth surface was defined as the image formation area, and a pretreatment liquid was applied to the entire image formation area by inkjet in step (A). In step (B), the pretreatment liquid was applied to the outer peripheral area of the image formation area by inkjet. The outer edge of the outer peripheral area was a rectangular range that was 9 dots (about 0.38 mm) larger in each of the up, down, left, and right directions with the image formation area as the center. Note that no drying process was provided after steps (A) and (B) in any of the examples and comparative examples.

[0136] White ink was applied to the entire image formation area.

[0137] After applying the white ink, it was heated and dried at 120 °C for 1 minute using a heat press machine manufactured by FUSION to obtain a resist-dyed product.

[0138] [Evaluation of bleeding at the image contour part] The contour part of the white image was confirmed with a microscope, and the evaluation was performed using the value of the bleeding width at the location where the bleeding width was the largest.

[0139] [Evaluation of hiding power of the white image] Using a spectrophotometer, the L value of the white image was measured and evaluated according to the following criteria. For the measurement, a spectrophotometer "eXact" manufactured by X-Rite was used.

[0140] A: The L value is 90 or more B: The L value is 80 or more and less than 90 C: The L value is less than 80

[0141] [Table 3]

[0142] For the resist-dyed products of Examples 1 and 2 where pretreatment was performed in steps (A) and (B), bleeding at the contour part was effectively suppressed. Also, in Example 1 where a white ink with a charge density of 30 μeq / g or more was used, the hiding power of the white image was also high.

[0143] In Comparative Example 1 where step (B) was not performed, bleeding at the contour part was large.

Claims

1. A step (A) of applying a pretreatment liquid (a) containing an ink flocculant to an image forming area of a cloth by an inkjet method, and a step (B) of applying a pretreatment liquid (b) containing an ink flocculant to an outer peripheral area of the image forming area of the cloth by an inkjet method, the pretreatment method for inkjet printing.

2. The pretreatment method according to claim 1, wherein the ink flocculant contained in the pretreatment liquid (a) is a metal salt, and the ink flocculant contained in the pretreatment liquid (b) is a metal salt.

3. The pretreatment method according to claim 1, wherein in the step (B), the width of the outer peripheral area is in the range of 0.01 to 0.5 mm.

4. The pretreatment method according to claim 1, wherein after the step (A), the step (B) is performed in a wet-on-wet method.

5. An inkjet printing method of applying ink having a charge density of 30 μeq / g or more by an inkjet method after performing pretreatment by the pretreatment method according to any one of claims 1 to 4.

6. The inkjet printing method according to claim 5, wherein the application of ink after pretreatment is performed in a wet-on-wet method.

7. The inkjet printing method according to claim 5, wherein the ink having a charge density of 30 μeq / g or more is white ink.

8. The inkjet printing method according to claim 7, wherein after applying white ink, non-white ink is further applied by an inkjet method.

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