Printer and method for manufacturing printed textile

Abstract

To provide a printer and a method for manufacturing a printed textile capable of manufacturing a printed textile in which image cracking caused by washing is suppressed.SOLUTION: A measurement unit measures the penetration speed of a pretreatment liquid that flocculates ink into a fabric. A pretreatment liquid discharge head 41 discharges the pretreatment liquid. A white ink discharge head 42 discharges white ink. A color ink discharge head 43 discharges color ink. A control unit performs control so as to cause the pretreatment liquid discharge head 41 to discharge the pretreatment liquid to the fabric, the white ink discharge head 42 to discharge white ink to the fabric to which the pretreatment liquid has been discharged through a wet-on-wet method, and the color ink discharge head 43 to discharge color ink to the fabric to which the pretreatment liquid and the white ink have been discharged through the wet-on-wet method. The control unit controls the discharge amount of the white ink by the white ink discharge head 42 on the basis of the penetration speed measured by the measurement unit.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a printing apparatus and a method for manufacturing a printed and dyed product.

Background Art

[0002] Techniques for manufacturing printed and dyed products by printing images such as characters, pictures, and patterns on fabrics such as clothing are known.

[0003] Regarding such techniques, Patent Document 1 discloses an image forming apparatus that rubs a portion where an image is formed on a recording medium such as a fabric with a friction member and controls the discharge amount of a pretreatment agent applied to the recording medium according to the degree of contamination of the friction member. In this image forming apparatus, it is possible to set the application amount of the pretreatment agent that has sufficient rubbing fastness without impairing the touch and texture.

[0004] Further, Patent Document 2 discloses an inkjet printing and dyeing apparatus that can form an image having a desired rubbing fastness by controlling the application amount of a treatment liquid according to the type of the printing and dyeing target.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, when washing a printed and dyed product as described above, cracks may occur in the image. Although the techniques of Patent Documents 1 and 2 can manufacture printed and dyed products with high rubbing fastness, they cannot suppress cracks in the image caused by washing.

[0007] The present invention has been made in view of the above, and an object thereof is to provide a printing apparatus capable of manufacturing a resist-dyed product in which cracking of an image due to washing is suppressed, and a method for manufacturing a resist-dyed product.

Means for Solving the Problems

[0008] According to one aspect of the present invention, there is provided a printing apparatus including a measuring unit that measures the penetration rate of a pretreatment liquid for aggregating ink into cloth, a first discharge unit that discharges the pretreatment liquid, a second discharge unit that discharges white ink, a third discharge unit that discharges color ink, and a control unit that controls the first discharge unit to discharge the pretreatment liquid onto the cloth, the second discharge unit to discharge the white ink onto the cloth on which the pretreatment liquid has been discharged by the wet-on-wet method, and the third discharge unit to discharge the color ink onto the cloth on which the pretreatment liquid and the white ink have been discharged by the wet-on-wet method. The control unit controls the discharge amount of the white ink by the second discharge unit based on the penetration rate measured by the measuring unit.

[0009] According to another aspect of the present invention, there is provided a method for manufacturing a resist-dyed product including a step of measuring the penetration rate of a pretreatment liquid for aggregating ink into cloth, a step of discharging the pretreatment liquid onto the cloth, a step of discharging white ink onto the cloth on which the pretreatment liquid has been discharged by the wet-on-wet method, and a step of discharging color ink onto the cloth on which the pretreatment liquid and the white ink have been discharged by the wet-on-wet method. In the step of discharging the white ink, the discharge amount of the white ink is controlled based on the penetration rate measured in the step of measuring the penetration rate.

Effects of the Invention

[0010] According to the present invention, it is possible to manufacture a resist-dyed product in which cracking of an image due to washing is suppressed.

Brief Description of the Drawings

[0011]

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DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are denoted by the same or equivalent reference numerals throughout the drawings.

[0013] The embodiments shown below are examples of devices for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, arrangements, etc. of the respective components as those described below. The technical idea of the present invention can be variously modified within the scope of the claims.

[0014] FIG. 1 is a block diagram showing a schematic configuration of a printing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a measurement unit of the printing apparatus shown in FIG. 1. FIG. 3 is a schematic configuration diagram of a printing unit of the printing apparatus shown in FIG. 1.

[0015] As shown in FIG. 1, a printing apparatus 1 according to the present embodiment includes a measurement unit 2, a printing unit 3, and a control unit 4.

[0016] The measurement unit 2 measures the penetration rate of a pretreatment liquid into a cloth such as clothing, which is a printing medium.

[0017] Here, examples of the cloth include natural fibers such as cotton, silk, wool, and hemp; regenerated fibers such as cellulose-based and protein-based fibers; semi-synthetic fibers such as cellulose-based fibers; synthetic fibers such as polyamide, polyester, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, polyurethane, polyethylene, polypropylene, polystyrene, polyvinyl fluoride, acrylic, nylon, rayon, cupra, and acetate; or blended fibers thereof. Further, the cloth may be a woven fabric, a knitted fabric, a non-woven fabric, or the like.

[0018] The pretreatment liquid is a liquid that aggregates ink. Details of the pretreatment liquid will be described later.

[0019] As shown in FIG. 2, the measurement unit 2 includes a dropping unit 11, an imaging unit 12, a storage unit 13, and an arithmetic unit 14.

[0020] The dropping unit 11 drops the pretreatment liquid onto the cloth 16 disposed between lenses 22 and 23, which will be described later. The pretreatment liquid dropped by the dropping unit 11 is the same as the pretreatment liquid discharged by a pretreatment liquid discharge head 41 of the printing unit 3, which will be described later.

[0021] The imaging unit 12 captures an image (still image) of the cloth 16 from the side of the cloth 16. The imaging unit 12 includes a light source 21, lenses 22 and 23, an image sensor 24, and an image generation unit 25.

[0022] The light source 21 emits light. The light source 21 consists of a light-emitting diode, an incandescent bulb, etc.

[0023] The lens 22 converts the light from the light source 21 into parallel light and irradiates the fabric 16 from the side. If the light source 21 is one that emits parallel light, such as a surface light-emitting element or an array light-emitting element, the lens 22 can be omitted.

[0024] The lens 23 is arranged opposite to the lens 22 with the fabric 16 in between, and forms an image of the light from the fabric 16 side on the image sensor 24.

[0025] The image sensor 24 converts the brightness and darkness of the light incident from the lens 23 into an electrical signal and outputs it.

[0026] The image generation unit 25 generates an image based on the electrical signal output from the image sensor 24.

[0027] The storage unit 13 is a memory that stores the images captured by the imaging unit 12.

[0028] The arithmetic unit 14 determines the timing when the penetration of the pretreatment liquid into the fabric 16 is completed based on a plurality of images (still images) captured by the imaging unit 12 over time of the fabric 16 before and after the dropping of the pretreatment liquid from the dropping portion 11. Then, the arithmetic unit 14 calculates the penetration rate of the pretreatment liquid into the fabric 16 based on the timing when the pretreatment liquid is dropped onto the fabric 16 and the timing when the penetration of the pretreatment liquid into the fabric 16 is completed.

[0029] The printing unit 3 manufactures a tie-dyed product by performing printing on the fabric, which is the printing medium, by an inkjet method. As shown in FIG. 3, the printing unit 3 includes a head unit 31, a rail unit 32, and a conveying unit 33. Here, the direction perpendicular to the plane of FIG. 3 is the vertical direction, and the front surface direction of the plane of the drawing is the upward direction. Also, the front, back, left, and right in the plane of FIG. 3 are the front, back, left, and right directions.

[0030] The head unit 31 discharges a pretreatment liquid, white ink, and color ink onto the fabric to form an image. The head unit 31 includes a pretreatment liquid discharge head (corresponding to the first discharge unit) 41, a white ink discharge head (corresponding to the second discharge unit) 42, a plurality of color ink discharge heads (corresponding to the third discharge unit) 43, and a head holder 44.

[0031] The pretreatment liquid discharge head 41 discharges the pretreatment liquid. The pretreatment liquid discharge head 41 has a plurality of nozzles (not shown) that open on its lower surface (discharge surface) and are arranged along the front-rear direction (sub-scanning direction), and discharges the pretreatment liquid from the nozzles. Details of the pretreatment liquid will be described later.

[0032] The white ink discharge head 42 discharges white ink. The white ink discharge head 42 has the same configuration as the pretreatment liquid discharge head 41 except that the discharged liquid is different. The white ink discharge head 42 is arranged behind the pretreatment liquid discharge head 41 in the front-rear direction (sub-scanning direction). Details of the white ink will be described later.

[0033] The color ink discharge heads 43 discharge color ink. In the present embodiment, four color ink discharge heads 43 are provided. The four color ink discharge heads 43 discharge inks of different colors (for example, black, cyan, magenta, yellow). The color ink discharge heads 43 have the same configuration as the pretreatment liquid discharge head 41 except that the discharged liquid is different. The four color ink discharge heads 43 are arranged behind the white ink discharge head 42 in the front-rear direction (sub-scanning direction). The four color ink discharge heads 43 are arranged in parallel in the left-right direction (main scanning direction). Details of the color ink will be described later.

[0034] The head holder 44 holds the pretreatment liquid discharge head 41, the white ink discharge head 42, and the plurality of color ink discharge heads 43.

[0035] The rail unit 32 reciprocates the head unit 31 in the left-right direction (main scanning direction).

[0036] The conveying unit 33 has a supporting part (not shown) for supporting the cloth, and conveys the cloth supported by the supporting part in the conveying direction (sub-scanning direction) from the front side to the rear side below the head unit 31.

[0037] The control unit 4 controls the operation of the entire printing apparatus 1. The control unit 4 is configured to include a CPU, a RAM, a ROM, a hard disk, etc.

[0038] Specifically, the control unit 4 controls the measuring unit 2 to measure the penetration rate of the pretreatment liquid into the cloth printed by the printing unit 3. Further, the control unit 4 controls the printing unit 3 such that the pretreatment liquid discharge head 41 discharges the pretreatment liquid onto the cloth, the wet-on-wet method is used for the cloth onto which the pretreatment liquid has been discharged, and the white ink discharge head 42 discharges white ink, and the color ink discharge head 43 discharges color ink onto the cloth onto which the pretreatment liquid and the white ink have been discharged. At this time, the control unit 4 controls the discharge amount of the white ink by the white ink discharge head 42 based on the penetration rate measured by the measuring unit 2.

[0039] Here, the wet-on-wet method is a method of discharging a liquid onto a cloth in a state wet with the previously discharged liquid. The time from discharging the pretreatment liquid onto the cloth until discharging the white ink, and the time from discharging the white ink onto the cloth until discharging the color ink are the times during which the cloth maintains a wet state, and are, for example, within 100 seconds.

[0040] Next, the above-mentioned pretreatment liquid will be described.

[0041] As the pretreatment liquid, a pretreatment liquid containing a flocculant and water can be preferably used.

[0042] As the aggregating agent, a component having the function of aggregating the coloring material in the ink on the cloth which is the printing medium can be used. By this, when ink is further applied to the cloth to which the pretreatment liquid is applied, the coloring material in the ink aggregates on the cloth, the image density can be increased more, and bleeding of the image can be prevented. As specific examples of the aggregating agent, metal salts, cationic polymers, organic acids, etc., or combinations thereof can be used.

[0043] The total amount of the aggregating agent is preferably 1 to 30% by mass, more preferably 3 to 30% by mass, and still more preferably 5 to 15% by mass in terms of the active ingredient amount with respect to the total amount of the pretreatment liquid.

[0044] As the metal salt, a polyvalent metal salt can be preferably used.

[0045] The polyvalent metal salt is composed of a polyvalent metal ion of 2 or more valences and an anion. Examples of the polyvalent metal ion of 2 or more valences include Ca 2+ , Mg 2+ , Cu 2+ , Ni 2+ , Zn 2+ , Ba 2+ , Al 3+ , Y 3+ , etc. Since the reactivity tends to be high when the ionic radius is small, Ca 2+ and Mg 2+ are particularly preferable.

[0046] Examples of the anion include Cl - , NO 3- , CH 3 COO - , I - , Br - , ClO 3 - , etc.

[0047] Specific examples of the polyvalent metal salt include calcium chloride, calcium nitrate, magnesium nitrate, copper nitrate, calcium acetate, magnesium acetate, etc.

[0048] As the cationic polymer, a cationic water-soluble resin can be preferably used. Examples of the cationic water-soluble resin include polyethyleneimine (PEI), polyvinylamine, polyallylamine and its salts, polyvinylpyridine, copolymers of cationic acrylamide, and the like. More specifically, for example, polydiallyldimethylammonium chloride and the like can be used.

[0049] Examples of the organic acid include formic acid, acetic acid, oxalic acid, lactic acid, malic acid, citric acid, ascorbic acid, and the like.

[0050] The pretreatment liquid preferably contains water. The pretreatment liquid may contain a water-soluble organic solvent in addition to or instead of water.

[0051] The water is not particularly limited, and examples thereof include ion-exchanged water, distilled water, ultrapure water, and the like.

[0052] The water content is preferably 30 to 90% by mass, more preferably 40 to 85% by mass, and even more preferably 50 to 80% by mass based on the total amount of the pretreatment liquid.

[0053] As the water-soluble organic solvent, an organic compound that is liquid at room temperature (25°C) and soluble in water can be used, and it is preferable to use a water-soluble organic solvent that is uniformly mixed with the same volume of water at 1 atm and 20°C. For example, lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, 1,3-propanediol, 1,3-butanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 2-methyl-2-propanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol; Glycerins such as glycerin, diglycerin, triglycerin, and polyglycerin; Acetins such as monoacetin and diacetin; Glycol ethers 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, and tetraethylene glycol diethyl ether; β-Thiodiglycol, sulfolane, etc. can be used. The boiling point of the water-soluble organic solvent is preferably 100 °C or higher, more preferably 150 °C or higher.

[0054] These water-soluble organic solvents may be used alone or in combination of two or more as long as they form a single phase with water. When two or more water-soluble organic solvents are included, the total content is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and even more preferably 15 to 30% by mass based on the total amount of the pretreatment liquid.

[0055] The pretreatment liquid may further contain a surfactant. As the surfactant, any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant may be used, but a nonionic surfactant is more preferable. Also, either a low-molecular surfactant or a high-molecular surfactant may be used.

[0056] The HLB value of the surfactant is preferably 5 to 20, more preferably 10 to 18.

[0057] Examples of nonionic surfactants include ester surfactants such as glycerin fatty acid esters and sorbitan fatty acid esters; ether surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, and polyoxypropylene alkyl ethers; ether ester surfactants such as polyoxyethylene sorbitan fatty acid esters; acetylene surfactants; silicone surfactants; and fluorine surfactants. Among them, acetylene surfactants such as acetylene glycol surfactants can be preferably used.

[0058] Examples of acetylene surfactants include acetylene glycol surfactants, acetylene alcohol surfactants, and surfactants having an acetylene group.

[0059] The acetylene glycol surfactant is a glycol having an acetylene group, preferably a glycol having a symmetric structure with the acetylene group located in the center, and may have a structure in which ethylene oxide is added to the acetylene glycol.

[0060] Examples of commercially available acetylene surfactants include Surfynol series products such as "Surfynol 104E", "Surfynol 104H", "Surfynol 420", "Surfynol 440", "Surfynol 465", "Surfynol 485" manufactured by Evonik Industries, and Orfin series products such as "Orfin E1004", "Orfin E1010", "Orfin E1020" manufactured by Nissin Chemical Industry Co., Ltd. (all are trade names).

[0061] Examples of silicone surfactants include polyether-modified silicone surfactants, alkyl·aralkyl co-modified silicone surfactants, and acrylic silicone surfactants.

[0062] Examples of commercially available silicone surfactants include, for example, "Silface SAG002" and "Silface 503A" manufactured by Nissin Chemical Industry Co., Ltd. (both are trade names).

[0063] Examples of other nonionic surfactants include, for example, polyoxyethylene alkyl ether 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" manufactured by Kao Corporation (all are trade names).

[0064] Examples of anionic surfactants include, for example, the Emal series "Emal 0", "Emal 10", "Emal 2F", "Emal 40", "Emal 20C", etc., the Neoperex series "Neoperex GS", "Neoperex G-15", "Neoperex G-25", "Neoperex G-65", etc., the Perex series "Perex OT-P", "Perex TR", "Perex CS", "Perex TA", "Perex SS-L", "Perex SS-H", etc., the Demol series "Demol N, Demol NL", "Demol RN", "Demol MS", etc. manufactured by Kao Corporation (all are trade names).

[0065] Examples of cationic surfactants include, for example, the Acetamin series "Acetamin 24", "Acetamin 86", etc., the Cotamin series "Cotamin 24P", "Cotamin 86P", "Cotamin 60W", "Cotamin 86W", etc., the Sanizol series "Sanizol C", "Sanizol B-50", etc. manufactured by Kao Corporation (all are trade names).

[0066] Examples of amphoteric surfactants include, for example, the Anitol series products manufactured by Kao Corporation, such as "Anitol 20BS", "Anitol 24B", "Anitol 86B", "Anitol 20YB", "Anitol 20N", etc. (all are trade names).

[0067] The surfactant may be used alone or in combination of two or more.

[0068] The surfactant is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, based on the total amount of the pretreatment liquid in terms of the active ingredient content. When two or more surfactants are used, the content of the surfactants described above is the total content thereof.

[0069] The pretreatment liquid may further contain other components. Examples of other components include pH adjusters, preservatives, rust inhibitors, defoamers, etc.

[0070] The method for producing the pretreatment liquid is not particularly limited and can be appropriately produced by known methods. For example, 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, it can be obtained by passing through a filter such as a membrane filter.

[0071] Next, the aforementioned white ink will be described.

[0072] The white ink is discharged onto the cloth in order to conceal the color of the cloth and make the printed image easier to visually recognize even when the cloth, which is the printing medium, is a dark color such as black.

[0073] The white ink can contain a white pigment as a coloring material. By containing the white pigment, the white ink can be used to form an image presenting white. The white pigment can be either an inorganic pigment or an organic pigment, or a combination of these can be used.

[0074] Examples of white pigments include white inorganic pigments such as titanium oxide, zinc white, zinc sulfide, antimony oxide, zirconium oxide, etc. Furthermore, white organic pigments such as hollow resin fine particles and solid resin fine particles can also be used. Among them, from the viewpoint of hiding power, it is preferable to use titanium oxide pigment. The average particle diameter of the white pigment is preferably 50 nm or more, 100 nm or more, or 200 nm or more from the viewpoint of hiding power, and preferably 500 nm or less, 400 nm or less, 300 nm or less from the viewpoint of ejection stability. The average particle diameter of the titanium oxide pigment is more preferably 200 to 300 nm from the viewpoints of hiding power and ejection stability. When using a titanium oxide pigment, in order to suppress the photocatalytic action, it is preferable to use one that has been surface-treated with alumina, silica, etc. The surface treatment amount is preferably 5 to 20% by mass in the pigment.

[0075] Self-dispersible pigments may be used as the white pigment. Self-dispersible pigments are pigments in which hydrophilic functional groups are introduced onto the surface of the pigment by chemical treatment or physical treatment. As the hydrophilic functional groups to be introduced into the self-dispersible pigment, those having ionic properties are preferable, and by charging the pigment surface anionic or cationic, the pigment particles can be stably dispersed in water by electrostatic repulsive force. As the anionic functional group, a carboxy group, a sulfo group, a phosphoric acid group, etc. are preferable. As the cationic functional group, a quaternary ammonium group, a quaternary phosphonium group, etc. are preferable.

[0076] These hydrophilic functional groups may be directly bonded to the pigment surface or may be bonded via other atomic groups. Examples of other atomic groups include, but are not limited to, 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.

[0077] Also, as the white pigment, a pigment dispersion in which the pigment is previously dispersed with a pigment dispersant may be used. Also, as the white pigment, microencapsulated pigments in which the pigment is coated with a resin may be used.

[0078] The white pigment may be used singly or in combination of two or more.

[0079] From the viewpoint of hiding power and the like, the white pigment is preferably 5 to 30% by mass, more preferably 8 to 20% by mass, and still more preferably 10 to 12% by mass based on the total amount of the white ink.

[0080] In order to stably disperse the white pigment in the white ink, a pigment dispersant typified by a polymer dispersant, a surfactant type dispersant, etc. can be used.

[0081] Examples of the polymer dispersant include, as commercially available products, TEGO Disperse series "TEGO Disperse 740W", "TEGO Disperse 750W", "TEGO Disperse 755W", "TEGO Disperse 757W", "TEGO Disperse 760W", etc. manufactured by EVONIK, Solsperse series "Solsperse 20000", "Solsperse 27000", "Solsperse 41000", "Solsperse 41090", "Solsperse 43000", "Solsperse 44000", "Solsperse 46000", etc. manufactured by Lubrizol Japan Co., Ltd., 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 Japan Co., Ltd., "Polyvinylpyrrolidone K-30", "Polyvinylpyrrolidone K-90", etc. manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (all are trade names).

[0082] Examples of surfactant-type dispersants include 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).

[0083] The pigment dispersant may be used alone or in combination of two or more.

[0084] When using a pigment dispersant, the content in the ink varies depending on its type and is not particularly limited. Generally, a mass ratio of the active ingredient of 0.005 to 0.5 with respect to 1 of the white pigment is preferable.

[0085] The white ink preferably contains water and the main solvent may be water. The water is not particularly limited, but those containing as few ionic components as possible are preferable. In particular, from the viewpoint of the storage stability of the white ink, it is preferable that the content of polyvalent metal ions such as calcium is small. As the water, for example, ion-exchanged water, distilled water, ultrapure water, etc. may be used.

[0086] From the viewpoint of adjusting the ink viscosity, water is preferably contained in an amount of 30 to 90% by mass, more preferably 40 to 85% by mass, and even more preferably 50 to 80% by mass based on the total amount of the white ink.

[0087] The white ink can contain a water-soluble organic solvent.

[0088] As the water-soluble organic solvent, for example, those described in the above pretreatment liquid can be selected and used.

[0089] Among them, from the viewpoints of adjusting the ink viscosity and moisture retention, glycols, glycerins, or a combination thereof are preferable. As the glycols, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol are preferable. As the glycerins, glycerin is preferable.

[0090] The above water-soluble organic solvents may be used alone or in combination of two or more as long as they form a single phase with water. When two or more water-soluble organic solvents are included, the content thereof is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and even more preferably 15 to 30% by mass, based on the total amount of the white ink.

[0091] The white ink may further contain a surfactant. As the surfactant, for example, those described in the above pretreatment liquid can be selected and used. As the surfactant, any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant may be used, but a nonionic surfactant is more preferable. Also, either a low molecular weight surfactant or a high molecular weight surfactant may be used.

[0092] The content of the surfactant is preferably 0.1 to 5% by mass, more preferably 0.2 to 2% by mass, based on the total amount of the white ink.

[0093] The white ink may further contain a water-dispersible resin, a water-soluble resin, or a combination thereof. From the viewpoint of sufficiently fixing the pigment on the cloth and thereby obtaining high colorability with a small amount of pigment, the white ink preferably contains at least one of a water-dispersible resin and a water-soluble resin.

[0094] Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, neutralized polyacrylic acid, acrylic acid / maleic acid copolymer, acrylic acid / sulfonic acid copolymer, styrene / maleic acid copolymer, etc. These may be used alone or in combination of two or more kinds.

[0095] The water-dispersible resin is preferably resin particles dispersible in an aqueous solvent. The water-dispersible resin can be blended into the ink as, for example, an oil-in-water type resin emulsion.

[0096] The water-dispersible resin may be a self-emulsifying type into which a hydrophilic component is introduced in order to be stably dispersed in water, or may be one that becomes water-dispersible by using an external emulsifier.

[0097] From the viewpoint of inkjet ejection property, the average particle diameter of the water-dispersible resin is preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 150 nm or less. For example, the average particle diameter of the water-dispersible resin may be in the range of 10 nm to 300 nm.

[0098] Here, the average particle diameter of the resin is the average particle diameter based on volume and is a value measured by the light scattering method.

[0099] The water-dispersible resin may be any of anionic, cationic, nonionic, and amphoteric. From the viewpoint of more stably dispersing the water-dispersible resin in the aqueous ink, the water-dispersible resin is preferably anionic or nonionic.

[0100] As the water-dispersible resin, an anionic water-dispersible resin having anionic functional groups such as a carboxy group, a sulfo group, and a hydroxy group is preferable.

[0101] As the type of the water-dispersible resin, a resin forming a transparent coating film is preferably used. Further, the water-dispersible resin can be blended as a resin emulsion in the production of the ink.

[0102] Typical examples include urethane resins, (meth)acrylic resins, styrene / (meth)acrylic resins, polyester resins, olefin resins, vinyl chloride resins, vinyl acetate resins, melamine resins, amide resins, ethylene-vinyl chloride copolymers, styrene-(meth)acrylic resins, styrene-maleic anhydride copolymer resins, vinyl acetate-(meth)acrylic copolymer resins, vinyl acetate-ethylene copolymer resins, silicone resins, and the like, as well as composite resins thereof.

[0103] As the water-dispersible resin, a water-dispersible urethane resin, a water-dispersible polyester resin, or a combination thereof is preferable.

[0104] Examples of commercially available water-dispersible resins include "Superflex 470" (water-dispersible urethane resin) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., and "Eter KT9204" (water-dispersible polyester resin) manufactured by Unitika Ltd. (both are trade names).

[0105] The above-described water-dispersible resin may be used alone or in combination of two or more.

[0106] The water-dispersible resin preferably has a non-volatile content of 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the white ink. The water-dispersible resin preferably has a non-volatile content of 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the white ink. For example, the water-dispersible resin preferably has a non-volatile content of 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 20% by mass, based on the total amount of the white ink.

[0107] The water-dispersible resin preferably has a mass ratio of non-volatile content of 0.1 to 10, more preferably 1 to 3, relative to Pigment 1.

[0108] The total amount of the water-dispersible resin and the water-soluble resin is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more in terms of the non-volatile content with respect to the total amount of the white ink. The total amount of the water-dispersible resin and the water-soluble resin is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less in terms of the non-volatile content with respect to the total amount of the white ink. For example, the total amount of the water-dispersible resin and the water-soluble resin is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 20% by mass in terms of the non-volatile content with respect to the total amount of the white ink.

[0109] The total amount of the water-dispersible resin and the water-soluble resin is preferably 0.1 to 10, more preferably 1 to 3 in terms of the mass ratio of the non-volatile content to the pigment 1.

[0110] The white ink may further contain other components. Examples of the other components include pH adjusters, preservatives, rust preventives, defoamers, amine compounds, and the like.

[0111] The method for producing the white ink is not particularly limited and can be appropriately produced by a known method. For example, 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.

[0112] The pH of the white ink is preferably 7.0 to 10.0, more preferably 7.5 to 9.0 from the viewpoint of the storage stability of the ink.

[0113] The viscosity of the white ink can be adjusted as appropriate. For example, from the viewpoint of ejection property, the viscosity at 23°C is preferably 1 to 30 mPa·s.

[0114] Next, the above-mentioned color ink will be described.

[0115] Examples of the color ink include inks other than the white ink such as black ink, cyan ink, magenta ink, and yellow ink.

[0116] The color ink can contain, as a coloring material, a pigment, a dye, or a combination thereof, and preferably can contain a pigment.

[0117] Preferably, the pigment includes a non-white pigment.

[0118] As the non-white pigment, 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. These pigments may be used alone or in combination of two or more.

[0119] From the viewpoints of ejection stability and storage stability, the average particle diameter of the pigment particles in the ink is preferably 300 nm or less, more preferably 150 nm or less, and even more preferably 100 nm or less, as the volume-based average value in the particle size distribution measured by the dynamic light scattering method.

[0120] Self-dispersing pigments may be used as the non-white pigment. The details of the self-dispersing pigments are as described for the white pigments.

[0121] As the self-dispersing pigment, for example, CAB-O-JET series products such as "CAB-O-JET200", "CAB-O-JET300", "CAB-O-JET250C", "CAB-O-JET260M", "CAB-O-JET270", "CAB-O-JET450C" manufactured by Cabot Corporation, and "BONJET BLACK CW-1", "BONJET BLACK CW-2", "BONJET BLACK CW-3", "BONJET BLACK CW-4" manufactured by Orient Chemical Industries Co., Ltd. etc. (all are trade names) can be preferably used.

[0122] As the pigment, microencapsulated pigments in which the pigment is coated with a resin may be used.

[0123] A pigment dispersion in which the pigment is pre-dispersed with a pigment dispersant may be used. Examples of commercially available products of pigment dispersions dispersed with a pigment dispersant include the HOSTAJET series manufactured by Clariant and the FUJI SP series manufactured by Fuji Pigment Co., Ltd.

[0124] As the dye, water-soluble dyes among basic dyes, acidic dyes, direct dyes, soluble vat dyes, acid mordant dyes, mordant dyes, reactive dyes, vat dyes, sulfur dyes, etc. and water-soluble dyes made water-soluble by reduction etc. can be preferably used. Also, disperse dyes such as azo-based, anthraquinone-based, azomethine-based, nitro-based etc. can be preferably used. These may be used alone or in combination of multiple types.

[0125] The colorant may be used alone or in combination of two or more.

[0126] From the viewpoints of printing density and ink viscosity, the content of the colorant is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, and even more preferably 2 to 7% by mass based on the total amount of the color ink.

[0127] When using a pigment as a coloring material in a color ink, in order to stably disperse the pigment in the color ink, a pigment dispersant typified by a polymer dispersant, a surfactant-type dispersant, etc. can be used. As the pigment dispersant, for example, it can be selected and used from those described above for the white ink.

[0128] When using a pigment dispersant, the content in the color ink varies depending on its type and is not particularly limited. Generally, a mass ratio of the active ingredient of 0.005 to 0.5 with respect to 1 of the pigment is preferable.

[0129] The color ink preferably contains water. The color ink may contain, in addition to water, or instead of water, a water-soluble organic solvent. Details of the water and the water-soluble organic solvent are as described above for the white ink. As the water-soluble organic solvent, for example, it can be selected and used from those described above for the white ink.

[0130] From the viewpoint of adjusting the ink viscosity, water is preferably contained in an amount of 20% to 80% by mass, more preferably 30% to 70% by mass, based on the total amount of the color ink.

[0131] The water-soluble organic solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, based on the total amount of the color ink.

[0132] The color ink may further contain a surfactant. As the surfactant, for example, it can be selected and used from those described above for the white ink. Among them, a nonionic surfactant is preferable, and an acetylene-based surfactant such as an acetylene glycol-based surfactant is more preferable.

[0133] The surfactant is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, based on the total amount of the color ink in terms of the amount of the active ingredient.

[0134] The color ink may further contain resins such as a water-dispersible resin and a water-soluble resin. For example, by including a fixing resin in the color ink, the fixability of the printed image to the fabric, the coating film strength of the image, etc. can be further enhanced. From the viewpoint of obtaining ejection properties and storage stability suitable for inkjet ink, it is preferable that the color ink contains a water-dispersible resin. The water-dispersible resin is preferably one that is blended in the form of a water-in-oil emulsion in the color ink and can be dispersed in the form of resin particles in the color ink. As the water-dispersible resin, for example, those described above for the white ink can be selected and used, and it may be a water-dispersible urethane resin, other water-dispersible resins, or a combination thereof.

[0135] The water-dispersible resin is preferably 1 to 30% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass based on the total amount of the color ink.

[0136] The color ink may further contain a crosslinking agent. By including a crosslinking agent in the color ink, the coating film strength of the image can be further enhanced. By increasing the coating film strength, cracking of the image can be further suppressed even after washing the printed matter. Examples of the crosslinking agent include carbodiimide-based compounds, isocyanate-based compounds, oxazoline-based compounds, etc.

[0137] The crosslinking agent is preferably 0.1 to 5% by mass, more preferably 0.2 to 2% by mass based on the total amount of the color ink.

[0138] The color ink may further contain other components. Examples of the other components include a pH adjuster, a preservative, a rust inhibitor, an antifoaming agent, etc.

[0139] The method for producing the color ink is not particularly limited, and it can be appropriately produced by a known method. For example, 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.

[0140] From the perspective of the storage stability of the ink, the pH of the color ink is preferably from 7.0 to 10.0, more preferably from 7.5 to 9.0.

[0141] The viscosity of the color ink can be adjusted as appropriate. For example, from the perspective of ejection performance, the viscosity at 23°C is preferably 1 to 30 mPa·s.

[0142] Next, the operation of the printing apparatus 1 will be described.

[0143] In step S1 of FIG. 4, the control unit 4 causes the imaging unit 12 of the measurement unit 2 to image the cloth 16 disposed between the lenses 22 and 23.

[0144] Specifically, the control unit 4 causes the image generation unit 25 to generate an image based on the electrical signal output from the image sensor 24, and stores this image in the storage unit 13. This image is an image of the cloth 16 in a state before the pretreatment liquid is dropped. An example of the image of the cloth 16 before the dropping of the pretreatment liquid is shown in FIG. 5.

[0145] Next, in step S2 of FIG. 4, the calculation unit 14 binarizes the image captured in step S1. Specifically, the calculation unit 14 reads the image captured in step S1 from the storage unit 13, binarizes the luminance of each pixel of this image based on a predetermined threshold value to generate a binarized image, and stores this in the storage unit 13.

[0146] The binarized image obtained by binarizing the image of FIG. 5 is shown in FIG. 6. In FIG. 6, one grid represents one pixel, and the number within the grid indicates the pixel value. The region where the pixel value is "0" is the region where the cloth 16 exists, and the region where the pixel value is "1" is the region where the cloth 16 does not exist.

[0147] Returning to FIG. 4, in step S3, the control unit 4 drops a predetermined amount of the pretreatment liquid from the dropping unit 11 onto the cloth 16. In the present embodiment, the dropping unit 11 drops 0.05 ml of the pretreatment liquid onto the cloth 16. As a result, as shown in FIG. 2, droplets of the pretreatment liquid land on the cloth 16. The pretreatment liquid dropped on the cloth 16 penetrates into the cloth 16 over time. Here, in step S3, the pretreatment liquid is dropped outside the area where the image will be printed in a later-described step S12 on the cloth 16. Also, in the present embodiment, the pretreatment liquid dropped by the dropping unit 11 and the pretreatment liquid discharged by the pretreatment liquid discharge head 41 of the printing unit 3 contain the aforementioned polyvalent metal ions.

[0148] Next, in step S4 of FIG. 4, the control unit 4 causes the arithmetic unit 14 to start measuring the penetration time of the pretreatment liquid into the cloth 16. Here, the arithmetic unit 14 starts measuring the penetration time at the timing when the pretreatment liquid dropped from the dropping unit 11 lands on the cloth 16 (the timing when the pretreatment liquid is dropped onto the cloth 16). The timing when the pretreatment liquid lands on the cloth 16 is obtained from the distance between the dropping unit 11 and the cloth 16.

[0149] Next, in step S5, the control unit 4 causes the imaging unit 12 to image the cloth 16 onto which the pretreatment liquid has been dropped. Here, the control unit 4 causes the first imaging by the imaging unit 12 after the dropping of the pretreatment liquid to be performed before the timing at which it is assumed that the penetration of the pretreatment liquid is completed. The timing of performing the first imaging after the dropping of the pretreatment liquid may be simultaneous with the start of the measurement of the penetration time in step S4.

[0150] Next, in step S6, the arithmetic unit 14 binarizes the image captured in step S5.

[0151] Here, an example of an image of the cloth 16 before the penetration of the pretreatment liquid is completed, which is captured in step S5 after the dropping of the pretreatment liquid, is shown in FIG. 7. Further, a binarized image obtained by binarizing the image of FIG. 7 in step S6 is shown in FIG. 8. In the image of FIG. 7, there is a pretreatment liquid that has not yet penetrated into the cloth 16 on the cloth 16. In the binarized image of FIG. 8, in addition to the region where the cloth 16 exists, the pixel values of the regions where the pretreatment liquid that has not penetrated into the cloth 16 exist are "0". The region where the pixel value is "1" is a region where neither the cloth 16 nor the pretreatment liquid exists.

[0152] Returning to FIG. 4, in step S7, the arithmetic unit 14 calculates a difference value of the pixel value of each pixel, which is a value obtained by subtracting the pixel value of each pixel of the binarized image generated in step S6 from the pixel value of each pixel of the binarized image generated in step S2. For pixels with the same pixel value in the binarized image generated in step S2 and the binarized image generated in step S6, the difference value is "0", and for pixels with different pixel values, the difference value is other than "0" ("1" or "-1").

[0153] Here, FIG. 9 shows the difference value of each pixel obtained by subtracting the pixel value of each pixel of the binarized image of FIG. 8 from the pixel value of each pixel of the binarized image of FIG. 6. The region where the difference value is "1" in FIG. 9 corresponds to the region where the pretreatment liquid that has not penetrated into the cloth 16 exists in the image of FIG. 7.

[0154] Returning to FIG. 4, in step S8, the arithmetic unit 14 determines whether the number of pixels with a difference value other than "0" in the difference value of each pixel calculated in step S7 is less than or equal to a predetermined threshold value. Here, the threshold value of the number of pixels with a difference value other than "0" is for determining whether the penetration of the pretreatment liquid dropped on the cloth 16 into the cloth 16 is completed.

[0155] When the penetration of the pretreatment liquid into the cloth 16 is completed, there is no difference between the image captured thereafter and the image captured in step S2 before the dropping of the pretreatment liquid. Therefore, the number of pixels with a difference value other than "0" becomes "0". However, due to imaging noise or noise caused by changes in the surface state of the cloth 16 due to the dropping of the pretreatment liquid, even when the penetration of the pretreatment liquid into the cloth 16 is completed, the number of pixels with a difference value other than "0" may not become "0". For this reason, in the present embodiment, the above-described threshold value is provided.

[0156] When it is determined that the number of pixels with a difference value other than "0" exceeds the threshold value (step S8: NO), in step S9, the arithmetic unit 14 determines whether or not a predetermined imaging interval time has elapsed since the most recent imaging of the cloth 16 was performed. Here, the imaging interval time is a time preset as the interval of the imaging timing of the cloth 16 onto which the pretreatment liquid has been dropped.

[0157] When it is determined that the imaging interval time has not elapsed (step S9: NO), the arithmetic unit 14 repeats step S9. When the arithmetic unit 14 determines that the imaging interval time has elapsed (step S9: YES), the process returns to step S5.

[0158] In step S8, when it is determined that the number of pixels with a difference value other than "0" is equal to or less than the threshold value (step S8: YES), in step S10, the arithmetic unit 14 determines that the penetration of the pretreatment liquid into the cloth 16 is completed and ends the measurement of the penetration time. The arithmetic unit 14 calculates the elapsed time from the timing when the measurement of the penetration time was started in step S4 (the timing when the pretreatment liquid was dropped onto the cloth 16) to the timing when the measurement of the penetration time was ended (the timing when the penetration of the pretreatment liquid into the cloth 16 was completed) as the penetration time A (seconds) of 0.05 ml of the pretreatment liquid. Further, the arithmetic unit 14 calculates the reciprocal 1 / A of this penetration time as the penetration rate of 0.05 ml of the pretreatment liquid into the cloth 16.

[0159] Here, FIG. 10 shows an example of an image of the cloth 16 after the dropping of the pretreatment liquid and after the penetration of the pretreatment liquid has been completed, which is imaged in step S5. Further, FIG. 11 shows a binarized image obtained by binarizing the image of FIG. 10 in step S6. Further, FIG. 12 shows the difference value of each pixel obtained by subtracting the pixel value of each pixel of the binarized image of FIG. 11 from the pixel value of each pixel of the binarized image of FIG. 6.

[0160] In the image of FIG. 10, there is no pretreatment liquid on the cloth 16. However, in FIG. 12, there are pixels whose difference value is other than "0". This is considered to be due to the noise described above. In the example of FIG. 12, the number of pixels whose difference value is other than "0" is equal to or less than the threshold value, and it is determined that the penetration of the pretreatment liquid into the cloth 16 has been completed.

[0161] Returning to FIG. 4, in step S11, the control unit 4 determines the discharge amount of the white ink when performing printing in step S12 described later based on the penetration rate 1 / A of the pretreatment liquid into the cloth 16.

[0162] Here, the water repellency of the cloth varies depending on its type. For example, the water repellency of the cloth varies depending on the type of fiber of the cloth, whether the cloth is a woven fabric, a knitted fabric, or a non-woven fabric, etc. Also, even for cloths of the same type, there are individual differences in water repellency. And depending on the water repellency of the cloth, the discharge amount of the white ink that can suppress the cracking of the image when the cloth (printed fabric) on which the image has been formed by the printing apparatus 1 is washed is different.

[0163] The penetration rate 1 / A of 0.05 ml of the pretreatment liquid into the cloth 16 calculated in step S11 indicates the water repellency of the cloth 16. Therefore, in the printing apparatus 1, as described above, the discharge amount of the white ink is determined based on the penetration rate 1 / A of the pretreatment liquid into the cloth 16.

[0164] Specifically, when the penetration rate 1 / A is a value within a reference range such that the pretreatment liquid appropriately sinks into the cloth 16, the control unit 4 sets the discharge amount B (g / m 2 ) per unit area of the white ink to a value equal to or less than a predetermined discharge amount at which there is little possibility of cracking of the image due to washing.

[0165] Further, when the penetration rate 1 / A exceeds the upper limit of the above-mentioned reference range, that is, when the pretreatment liquid is likely to sink deeply into the fabric 16, the control unit 4 increases the upper limit of the discharge amount B per unit area of the white ink to be larger than the above-mentioned predetermined discharge amount.

[0166] Also, when the penetration rate 1 / A is equal to or less than the lower limit of the above-mentioned reference range, that is, when the pretreatment liquid is likely to remain on the surface of the fabric 16, the control unit 4 decreases the upper limit of the discharge amount B per unit area of the white ink to be smaller than the above-mentioned predetermined discharge amount.

[0167] More specifically, when 1 / 60 < 1 / A ≤ 1 / 10, that is, when 10 ≤ A < 60, the control unit 4 sets the discharge amount B per unit area of the white ink to 200 g / m 2 That is, in this case, the following formula (1) is satisfied.

[0168] B ≤ 200 …(1) Also, when 1 / A > 1 / 10, that is, when A < 10, the control unit 4 makes the value of (A × 10 + B) be at most 300. That is, in this case, the discharge amount B per unit area of the white ink satisfies the following formula (2).

[0169] B ≤ 300 - 10A …(2) Also, when 1 / A ≤ 1 / 60, that is, when A ≥ 60, the control unit 4 makes the value of (A × 10 + B) be at most 0.98 × (A × 10 + 200). That is, in this case, the discharge amount B per unit area of the white ink satisfies the following formula (3).

[0170] B ≤ 196 - 0.2A …(3) The above formulas (1) to (3) are derived in accordance with the fact that the ease of sinking of the pretreatment liquid into the fabric 16 varies depending on the value of the penetration rate 1 / A as described above and the experimental results.

[0171] Next, in step S12, the control unit 4 controls the printing unit 3 to perform printing on the fabric based on the image data to be printed. The image data is input to the printing apparatus 1 from an external device, for example.

[0172] Specifically, first, the control unit 4 controls the conveyance unit 33 to move the fabric supported by a support unit (not shown) to the printing initial position. Here, the fabric whose penetration rate has been measured in the above-described steps S1 to S10 is installed on the support unit of the conveyance unit 33 by the work of the user or the like.

[0173] Next, while moving the head unit 31 in the main scanning direction, the control unit 4 discharges the pretreatment liquid from the pretreatment liquid discharge head 41 to the same area on the fabric where the image based on the image data is formed by the color ink. Thereby, the discharge operation for the first one pass is performed.

[0174] Next, the control unit 4 moves the fabric rearward by a predetermined distance by the conveyance unit 33. Next, while moving the head unit 31 in the direction opposite to that during the discharge operation of the previous pass, the control unit 4 discharges the pretreatment liquid from the pretreatment liquid discharge head 41 and discharges white ink from the white ink discharge head 42.

[0175] Here, the control unit 4 discharges the white ink to the same area on the fabric where the pretreatment liquid was discharged in the previous pass. The control unit 4 controls the discharge of the white ink to be performed by the wet-on-wet method. Further, the control unit 4 sets the discharge amount of the white ink to the discharge amount determined in step S11 described above. Here, in the present embodiment, the white ink contains the white pigment described above.

[0176] Next, the control unit 4 moves the cloth backward by a predetermined distance by the conveying unit 33. Next, while moving the head unit 31 in the direction opposite to that during the discharge operation of the previous pass, the control unit 4 discharges the pretreatment liquid from the pretreatment liquid discharge head 41, discharges the white ink from the white ink discharge head 42, and discharges the color ink from the color ink discharge head 43 onto the area of the cloth where the pretreatment liquid and the white ink have been discharged up to the previous pass to form an image. The control unit 4 controls the discharge of the color ink to be performed by the wet-on-wet method.

[0177] While alternately repeating the movement of the head unit 31 in the main scanning direction and the backward movement of the cloth as described above, the control unit 4 performs a step of discharging the pretreatment liquid onto the cloth, a step of discharging the white ink by the wet-on-wet method onto the area of the cloth where the pretreatment liquid has been discharged, and a step of discharging the color ink by the wet-on-wet method onto the area where the pretreatment liquid and the white ink have been discharged, thereby printing an image on the cloth.

[0178] When the printing based on the image data is completed, the series of operations is completed.

[0179] As described above, the printing apparatus 1 includes the measurement unit 2 that measures the penetration rate of the pretreatment liquid into the cloth. The control unit 4 controls the discharge amount of the white ink by the white ink discharge head 42 based on the penetration rate measured by the measurement unit 2. Thereby, by making the discharge amount of the white ink the discharge amount according to the water repellency of the cloth, it is possible to manufacture a resist-dyed product in which cracking of the image due to washing is suppressed.

[0180] Further, in the printing apparatus 1, the calculation unit 14 of the measurement unit 2 determines the timing at which the penetration of the pretreatment liquid into the cloth is completed based on a plurality of images (still images) taken over time by the imaging unit 12 of the cloth before and after the dropping of the pretreatment liquid by the dropping unit 11. Then, the calculation unit 14 calculates the penetration rate of the pretreatment liquid into the cloth based on the timing when the pretreatment liquid is dropped onto the cloth and the timing when the penetration of the pretreatment liquid into the cloth is completed. In this way, by using the image of the cloth, the penetration rate of the pretreatment liquid into the cloth can be detected with high accuracy.

[0181] In the printing apparatus 1, the pretreatment liquid contains polyvalent metal ions, and the white ink contains a white pigment. By containing polyvalent metal ions in the pretreatment liquid, even when printing is performed by discharging white ink and color ink by the wet-on-wet method, the color development property can be enhanced to obtain good image quality. Further, since the white ink contains a white pigment, it can be used to form an image presenting white.

[0182] Here, polyvalent metal ions generally have a higher cohesive force than monovalent metal ions, cationic polymers, etc., and can enhance the color development property even in the same amount. Generally, when applying the pretreatment liquid to the fabric in printing by the wet-on-wet method, the application amount of the pretreatment liquid is significantly less than when applying the pretreatment liquid by the spray method used in printing other than the wet-on-wet method. Further, when the pretreatment liquid is applied to the fabric, the pretreatment liquid sinks into the fabric. For this reason, when applying the pretreatment liquid to the fabric in printing by the wet-on-wet method, in order to obtain good image quality, it is preferable that the pretreatment liquid contains polyvalent metal ions capable of enhancing the color development property even in a relatively small amount.

[0183] In the printing apparatus 1, when the penetration time of 0.05 ml of the pretreatment liquid into the fabric is A (seconds), the discharge amount B (g / m 2 ) of the white ink per unit area satisfies the above-mentioned formula (1) when 10 ≦ A < 60, satisfies the above-mentioned formula (2) when A < 10, and satisfies the above-mentioned formula (3) when A ≧ 60. Thereby, as the discharge amount of the white ink, a discharge amount that can suppress the possibility of the image cracking due to washing can be set.

[0184] In the above-described embodiment, based on a plurality of images (still images) captured by the imaging unit 12 over time of the fabric before and after dropping the pretreatment liquid from the dropping unit 11, the timing when the penetration of the pretreatment liquid into the fabric is completed was determined. Specifically, the timing when the penetration of the pretreatment liquid into the fabric was completed was determined by comparing the image of the fabric before dropping the pretreatment liquid with the image of the fabric after dropping the pretreatment liquid.

[0185] However, instead of using the image of the cloth before the dropping of the pretreatment liquid, the timing at which the penetration of the pretreatment liquid into the cloth is completed may be determined based on a plurality of images (still images) taken by the imaging unit 12 over time after the dropping of the pretreatment liquid. Specifically, after the dropping of the pretreatment liquid, when it is determined that there is no difference between two consecutive images (still images) taken of the cloth from its side, it may be determined that the penetration of the pretreatment liquid into the cloth is completed.

[0186] Also, based on at least a moving image of the cloth after the dropping of the pretreatment liquid taken from its side, the timing at which the penetration of the pretreatment liquid into the cloth is completed may be determined. In this case, the moving image may be stored, and after a lapse of time since the penetration of the pretreatment liquid into the cloth is completed, the timing at which the penetration of the pretreatment liquid into the cloth is completed may be determined based on the moving image.

[0187] Also, in the above-described embodiment, in the measurement unit 2, the penetration time A (seconds) of 0.05 ml of the pretreatment liquid into the cloth 16 and the penetration rate 1 / A were measured. And the discharge amount B (g / m 2 ) of the white ink per unit area was determined so as to satisfy the aforementioned formula (1) when 10 ≦ A < 60, satisfy the aforementioned formula (2) when A < 10, and satisfy the aforementioned formula (3) when A ≧ 60. However, the dropping amount of the pretreatment liquid in the measurement unit 2 is not limited to this, and the discharge amount B of the white ink may be determined according to the penetration rate measured at a predetermined dropping amount.

[0188] Also, in the above-described embodiment, the penetration rate of the pretreatment liquid into the cloth was measured using the image of the cloth, but it is not limited to this. For example, if the pretreatment liquid contains a metal salt, the penetration rate of the pretreatment liquid into the cloth may be measured by electrical detection.

[0189] Further, in the above-described embodiment, the pretreatment liquid and the white ink were ejected onto the same area on the cloth where the image was formed with the color ink. However, there may be a portion that does not overlap with the area on the cloth where the image is formed with the color ink in at least either the area where the pretreatment liquid is ejected or the area where the white ink is ejected. Also, the area where the pretreatment liquid is ejected may be an area wider than the area where the white ink is ejected and including the area where the white ink is ejected.

[0190] Further, in the above-described embodiment, the detection of the penetration rate of the pretreatment liquid into the cloth was performed before the ejection of the pretreatment liquid onto the cloth by the printing unit 3. However, if it is the timing at which the ejection of the white ink by the wet-on-wet method is possible, it may be performed after the ejection of the pretreatment liquid onto the cloth by the printing unit 3.

[0191] Further, in the above-described embodiment, the case where the printing apparatus 1 is a serial type inkjet printing apparatus has been described, but it may be a line type inkjet printing apparatus. Also, the ejection of the pretreatment liquid and the ejection of the white ink and the color ink may be performed by separate apparatuses to produce a printed fabric.

[0192] The present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the components can be modified and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment.

[0193] [Supplementary Note] This application discloses the following inventions.

[0194] (Supplementary Note 1) A measurement unit that measures the penetration rate of a pretreatment liquid that aggregates ink into the cloth, A first ejection unit that ejects the pretreatment liquid, A second ejection unit that ejects white ink, A third ejection unit that ejects color ink, The first discharge unit discharges the pretreatment liquid onto the fabric, the second discharge unit discharges the white ink onto the fabric on which the pretreatment liquid has been discharged by the wet-on-wet method, and the third discharge unit discharges the color ink onto the fabric on which the pretreatment liquid and the white ink have been discharged by the wet-on-wet method, and a control unit for controlling the discharge. The control unit controls the discharge amount of the white ink by the second discharge unit based on the penetration rate measured by the measurement unit. A printing apparatus characterized by this.

[0195] (Appendix 2) The measurement unit A dropping part for dropping the pretreatment liquid onto the fabric, An imaging unit for imaging a still image or a moving image of the fabric from the side of the fabric, Using a plurality of still images obtained by the imaging unit imaging the fabric before and after dropping the pretreatment liquid from the dropping part over time, or a plurality of still images or moving images obtained by the imaging unit imaging the fabric after dropping the pretreatment liquid from the dropping part over time, the timing when the penetration of the pretreatment liquid into the fabric is completed is determined, and based on the timing when the pretreatment liquid is dropped onto the fabric and the timing when the penetration of the pretreatment liquid into the fabric is completed, an arithmetic unit for calculating the penetration rate The printing apparatus according to Appendix 1, characterized by having this.

[0196] (Appendix 3) The pretreatment liquid contains polyvalent metal ions, The white ink contains a white pigment. The printing apparatus according to Appendix 1 or 2, characterized by this.

[0197] (Appendix 4) When the penetration time of 0.05 ml of the pretreatment liquid into the fabric is A (seconds), the discharge amount B (g / m 2 ) of the white ink per unit area is When 10 ≦ A < 60, it satisfies the following formula (1), When A < 10, it satisfies the following formula (2), When A ≧ 60, it satisfies the following formula (3). The printing apparatus according to any one of Appendices 1 to 3, characterized by this.

[0198] B ≤ 200 …(1) B ≤ 300 - 10A …(2) B ≤ 196 - 0.2A …(3) (Appendix 5) A step of measuring the penetration rate of the pretreatment liquid for aggregating the ink into the cloth, A step of discharging the pretreatment liquid onto the cloth, A step of discharging white ink onto the cloth onto which the pretreatment liquid has been discharged by the wet-on-wet method, A step of discharging color ink onto the cloth onto which the pretreatment liquid and the white ink have been discharged by the wet-on-wet method, and In the step of discharging the white ink, the discharge amount of the white ink is controlled based on the penetration rate measured in the step of measuring the penetration rate. A method for manufacturing a printed fabric characterized by this.

Example

[0199] Hereinafter, the present invention will be described in detail by way of examples. The present invention is not limited to the following examples.

[0200] (Adjustment of white pigment dispersion) 400 g of titanium oxide "R-21N" (manufactured by Sakai Chemical Industry Co., Ltd.) as a white pigment and 20 g (5 g of active ingredient) of "Demol EP" (manufactured by Kao Corporation) as a pigment dispersant were mixed with 580 g of ion-exchanged water, and using a bead mill (manufactured by Shinmaru Enterprises Co., Ltd., DYNO-MILL KDL A type), zirconia beads with a diameter of 0.5 mm were filled at a filling rate of 80% and dispersed for 5 minutes to obtain a white pigment dispersion (pigment content: 40% by mass).

[0201] (Preparation of white ink and pretreatment liquid) Table 1 shows the formulations of the white ink and the pretreatment liquid. According to the formulations described in Table 1, the raw materials were mixed and stirred with a mix rotor at 100 rpm for 20 minutes to obtain the white ink and the pretreatment liquid.

[0202]

Table 1

[0203] (Measurement of the Penetration Rate of the Pretreatment Liquid into the Fabric) As the fabric, a 100% black cotton T-shirt "Printstar 085-cvt" (manufactured by Tomus Co., Ltd.) was used. A droplet of 0.05 ml of the pretreatment liquid was dropped onto each of the 12 pieces of fabric, and the penetration time A (seconds) and the penetration rate 1 / A were measured for each.

[0204] (Printing on the Fabric) Two inkjet printers (textile printer "MMP-8130" manufactured by Mastermind Co., Ltd.) were prepared. The pretreatment liquid was introduced into the first printer, and white ink was introduced into the second printer.

[0205] Using the first printer, the pretreatment liquid was ejected over the entire 100 mm × 200 mm area of each of the 12 pieces of fabric. Then, using the second printer, white ink was ejected in a wet-on-wet method onto the area where the pretreatment liquid had been ejected for each of the 12 pieces of fabric to form a 100 mm × 200 mm solid white image.

[0206] Here, among the 12 pieces of fabric, for the fabrics of Examples 1 to 7, white ink was ejected at a discharge amount B (g / m 2 ) that satisfies any one of the formulas (1) to (3) corresponding to the penetration time A and the penetration rate 1 / A for each. For the fabrics of Comparative Examples 1 to 5, white ink was ejected at a discharge amount B that does not satisfy any one of the formulas (1) to (3) corresponding to the penetration time A and the penetration rate 1 / A for each. After the white ink was ejected, heat treatment was performed.

[0207] The penetration time A, the penetration rate 1 / A, the discharge amount B of white ink, and the value of (A × 10 + B) for each of Examples 1 to 7 and Comparative Examples 1 to 5 are as shown in Table 2.

[0208] (Cracking of the Image by Washing) The resist-dyed fabric obtained by printing on the fabric was cut into pieces of 25 mm × 40 mm to make test pieces. A test piece, a 10 mm Φ stainless steel ball, and washing water heated to 50 °C (a 0.1 mass% aqueous solution of a synthetic detergent for washing) were placed in a container with a capacity of 50 mL, and stirred for 10 minutes at a vibration frequency of 60 Hz using a high-speed ball mill stirrer locking mill. After drying the test piece after stirring in an environment of 23 °C for 3 hours, the state of cracking of the white ink image was visually observed and evaluated according to the following evaluation criteria. OK: No cracks are visible NG: Cracks are visible The evaluation results are shown in Table 2.

[0209]

Table 2

[0210] As shown in Table 2, Examples 1 to 7 showed excellent results in the evaluation of cracking of the image by washing.

Explanation of symbols

[0211] 1 Printing device 2 Measuring unit 3 Printing section 4 Control unit 11 Dropping section 12 Imaging section 13 Memory section 14 Arithmetic section 16 Fabric 21 Light source 22, 23 Lenses 24 Image sensor 25 Image generation section 31 Head unit 32 Rail section 33 Conveying section 41 Pretreatment liquid discharge head 42 White ink discharge head 43 Color ink discharge head 44 Head holder

Claims

1. A measuring unit that measures the penetration rate of a pretreatment liquid for aggregating ink into a cloth; A first discharge unit that discharges the pretreatment liquid; A second discharge unit that discharges white ink; A third discharge unit that discharges color ink; A control unit that controls the first discharge unit to discharge the pretreatment liquid onto the cloth, the second discharge unit to discharge the white ink onto the cloth on which the pretreatment liquid has been discharged by the wet-on-wet method, and the third discharge unit to discharge the color ink onto the cloth on which the pretreatment liquid and the white ink have been discharged by the wet-on-wet method; The control unit controls the discharge amount of the white ink by the second discharge unit based on the penetration rate measured by the measuring unit. A printing apparatus characterized by this.

2. The measuring unit A dropping unit that drops the pretreatment liquid onto the cloth; An imaging unit that images a still image or a moving image of the cloth from the side of the cloth; Based on a plurality of still images obtained by the imaging unit imaging the cloth before and after dropping the pretreatment liquid from the dropping unit over time, or a plurality of still images or moving images obtained by the imaging unit imaging the cloth after dropping the pretreatment liquid from the dropping unit over time, the timing when the penetration of the pretreatment liquid into the cloth is completed is determined, and based on the timing when the pretreatment liquid is dropped onto the cloth and the timing when the penetration of the pretreatment liquid into the cloth is completed, an arithmetic unit that calculates the penetration rate The printing apparatus according to claim 1, characterized by having this.

3. The pretreatment liquid contains polyvalent metal ions, The white ink contains a white pigment. The printing apparatus according to claim 1 or 2, characterized by this.

4. When the penetration time of the 0.05 ml of the pretreatment liquid into the cloth is A (seconds), the discharge amount B (g / m ２ ) of the white ink per unit area is When 10 ≦ A < 60, the following formula (1) is satisfied, When A < 10, the following formula (2) is satisfied, When A ≧ 60, the following formula (3) is satisfied. The printing apparatus according to claim 1 or 2, characterized by this. B ≦ 200 … (1) B ≦ 300 - 10A … (2) B ≦ 196 - 0.2A … (3)

5. A step of measuring the penetration rate of a pretreatment liquid for aggregating ink into a cloth; A step of discharging the pretreatment liquid onto the cloth; A step of discharging white ink onto the cloth on which the pretreatment liquid has been discharged by the wet-on-wet method; A step of discharging color ink onto the cloth on which the pretreatment liquid and the white ink have been discharged by the wet-on-wet method, In the step of discharging the white ink, the discharge amount of the white ink is controlled based on the penetration rate measured in the step of measuring the penetration rate. A method for manufacturing a resist-dyed product, characterized by this.

Images