JP7312368B2 - Pretreatment agent, pretreatment agent application apparatus, and image forming method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pretreatment agent, a pretreatment agent application apparatus, and an image forming method.

2. Description of the Related Art An image forming method is known in which an image is formed by ejecting ink onto cloth such as clothing. The image forming method includes, for example, a pretreatment step of applying a pretreatment agent to the fabric, and a thermal fixing step of thermally fixing the ink to the fabric after ejecting ink onto the pretreatment agent-applied portion (Patent Document 1).

Japanese Patent Publication No. 2017-517640

However, the pretreatment agent contains a highly water-resistant resin component (resin emulsion) from the viewpoint of washing fastness of the image forming part, and this resin component remains on the fabric even after washing. As a result, the fabric has a boundary between a portion to which the pretreatment agent is applied and a portion to which the pretreatment agent is not applied, which is undesirable in terms of appearance.

As a method for solving the problem of poor appearance, it is conceivable to use an aqueous polymer dispersion as the resin component, as described in Patent Document 1, in order to facilitate removal of the resin component by washing. However, in this method, the ink ejected onto the portion to which the pretreatment agent is applied tends to come off during washing.

As a method for solving the problem of ink peeling during washing, it is conceivable to include a reactive cross-linking agent in the pretreatment agent as described in Patent Document 1. However, in this method, the reactive cross-linking agent may cross-link with the aqueous polymer contained in the pretreatment agent, resulting in deposits. When the precipitate is generated, it is difficult to uniformly apply the pretreatment agent to the fabric. Further, if the components of the pretreatment agent are crosslinked, it is considered that improvement in washing fastness cannot be expected, and the traces of application of the pretreatment agent are difficult to remove by washing.

Accordingly, an object of the present invention is to provide a pretreatment agent that can easily remove traces of application without impairing the washing fastness of the image forming part and has excellent storage stability in image formation on fabric by an inkjet recording method.

In order to achieve the above object, the pretreatment agent of the present invention is
A pretreatment agent that is applied to the fabric before the ink when forming an image on the fabric,
an aqueous polymer substantially free of carboxyl groups;
a cross-linking agent capable of cross-linking the carboxyl groups of components contained in the ink;
characterized by comprising

The pretreatment agent of the present invention contains the aqueous polymer and the cross-linking agent, so that the traces of application can be easily removed without impairing the washing fastness of the image forming area, and the pretreatment agent has excellent storage stability.

FIGS. 1(a) and 1(b) are diagrams showing an example of application of a pretreatment agent in the image forming method of the present invention. FIG. 2 is a schematic diagram showing an example of the configuration of the inkjet recording apparatus of the present invention. 3 is a front view showing an example of the configuration of an inkjet printer of the inkjet recording apparatus shown in FIG. 2. FIG. FIG. 4(a) is a plan view showing a state in which a cloth is set on the platen of the inkjet recording apparatus shown in FIG. 2, and FIG. 4(b) is a cross-sectional view taken along the line AA in FIG. 4(a). FIG. 5 is a block diagram showing the configuration of the recording control device of the inkjet recording apparatus shown in FIG.

In the present invention, the term "aqueous polymer" includes water-soluble polymers, such as polymers that can be dispersed or dissolved in water.

The pretreatment agent of the present invention is a pretreatment agent that is applied to the fabric before ink is applied to the fabric when an image is formed on the fabric, and is characterized by containing an aqueous polymer that does not substantially contain carboxyl groups, and a cross-linking agent capable of cross-linking the carboxyl groups of components contained in the ink. The pretreatment agent of the present invention is characterized by containing the aqueous polymer and the cross-linking agent, and other configurations are not particularly limited. The pretreatment agent of the present invention may contain coloring agents such as pigments and dyes, but preferably does not contain coloring agents. The pretreatment agent of the present invention is preferably not ink and does not contain a coloring agent, for example. When the pretreatment agent of the present invention contains a coloring agent, the amount is such that it does not substantially become an ink for printing on fabric.

Said fabrics include both knitted and woven fabrics. The material of the cloth may be natural fiber or synthetic fiber. Examples of the natural fibers include cotton and silk. Examples of synthetic fibers include polyester, acrylic, rayon, urethane, and nylon. The material of the cloth may be a blend spun by mixing a plurality of types of fibers such as cotton/polyester=50%/50%.

The aqueous polymer is substantially free of carboxyl groups. Examples of the aqueous polymer include polyvinylpyrrolidone (water-soluble polymer), polyvinyl alcohol (water-soluble polymer), polyacrylamide (water-soluble polymer), hydroxyethyl cellulose (water-soluble polymer), starch (water-soluble polymer), dextrin (water-soluble polymer), and the like. Examples of the aqueous polymer include resins (aqueous dispersion polymers) obtained by emulsifying compounds composed of monomers such as styrene, acrylamide, ethylene and vinyl acetate.

As the aqueous polymer, for example, a commercial product may be used. Examples of the commercially available products include polyvinylpyrrolidone "Pitzcol (registered trademark) K-60L" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), vinyl acetate emulsion resin "Vinyblan (registered trademark) GV-6181" (manufactured by Nissin Chemical Industry Co., Ltd.), and polyvinyl alcohol "Kuraray Poval (registered trademark) PVA217" (manufactured by Kuraray Co., Ltd.).

Since the pretreatment agent of the present invention uses a water-based polymer as a resin component, traces of application can be easily removed by washing. In the pretreatment agent of the present invention, the aqueous polymer does not substantially contain a carboxyl group, so that the aqueous polymer does not crosslink with a crosslinking agent described later, or crosslinks only slightly. Therefore, as will be described later, the pretreatment agent of the present invention contains a cross-linking agent capable of cross-linking with the carboxyl groups of the components contained in the ink, thereby suppressing peeling of the ink during washing and excellent washing fastness. In addition, it can prevent or suppress the formation of precipitates due to cross-linking even during long-term storage, has excellent storage stability, and can be uniformly applied to the fabric.

At the time of use, the content of the aqueous polymer in the total amount of the pretreatment agent is, for example, 0.1% by weight to 0.5% by weight. In this case, for example, the pretreatment agent having a high concentration of the aqueous polymer may be prepared in advance and diluted (for example, diluted 3-fold with water) before use so that the content of the aqueous polymer falls within the above range, or the pretreatment agent may be prepared so that the content of the aqueous polymer falls within the above range.

The cross-linking agent is capable of cross-linking with carboxyl groups of components contained in the ink, which will be described later. Examples of the cross-linking agent include an oxazoline group-containing compound, a carbodiimide group-containing compound, an isocyanate group-containing compound, an aziridine group-containing compound, an epoxy group-containing compound, and an aqueous cross-linking agent obtained by imparting a hydrophilic segment to a polycarbodiimide resin.

As the cross-linking agent, for example, a commercially available product may be used. Examples of the commercially available products include "Epocross (registered trademark) WS-700" (manufactured by Nippon Shokubai Co., Ltd.), which is a water-soluble polymer containing an oxazoline group, and "Carbodilite (registered trademark) V-02" (manufactured by Nisshinbo Chemical Co., Ltd.), which is an aqueous cross-linking agent obtained by imparting a hydrophilic segment to a polycarbodiimide resin.

In the pretreatment agent of the present invention, the cross-linking agent contained therein and the carboxyl group of the component contained in the ink ejected onto the pretreatment agent can be crosslinked, so that the image forming portion has excellent washing fastness.

The content ratio of the cross-linking agent is, for example, 1 part by weight or more with respect to 100 parts by weight of the aqueous polymer. When the content is 1 part by weight or more, the wash fastness is more excellent. Also, the content of the cross-linking agent is, for example, 100 parts by weight or less with respect to 100 parts by weight of the aqueous polymer. When the content is 100 parts by weight or less, the traces of application of the pretreatment agent can be removed more easily, and the storage stability can be improved.

The pretreatment agent may further contain water. The water is preferably distilled water, ion-exchanged water or pure water. The content of the water in the total amount of the pretreatment agent may be, for example, the balance of other components.

The pretreatment agent may further contain additives such as a metal salt, a water-soluble organic solvent, a pH adjuster, a viscosity adjuster, a surface tension adjuster, an antiseptic, and an antifungal agent, if necessary. The metal salt is not particularly limited, and examples thereof include calcium chloride, calcium bromide, calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, calcium lactate, calcium fumarate, calcium citrate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, aluminum chloride, aluminum bromide, aluminum sulfate, aluminum nitrate, aluminum acetate, barium chloride, barium bromide, barium iodide, barium nitrate, barium thiocyanate, copper chloride, copper bromide, copper sulfate, copper nitrate. , copper acetate, iron chloride, iron bromide, iron iodide, iron sulfate, iron nitrate, iron oxalate, iron lactate, iron fumarate, iron citrate, manganese sulfate, manganese nitrate, manganese dihydrogen phosphate, manganese acetate, manganese salicylate, manganese benzoate, manganese lactate, nickel chloride, nickel bromide, nickel sulfate, nickel nitrate, nickel acetate, tin sulfate, titanium chloride, zinc chloride, zinc bromide, zinc sulfate, zinc thiocyanate, zinc acetate and their hydrates, etc. I can give Examples of the water-soluble organic solvent include polyhydric alcohols, polyhydric alcohol derivatives, alcohols, amides, ketones, ketoalcohols, ethers, nitrogen-containing solvents, sulfur-containing solvents, propylene carbonate, ethylene carbonate, 1,3-dimethyl-2-imidazolidinone and the like. Examples of the polyhydric alcohol include glycerin, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, hexylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylolpropane, 1,5-pentanediol and 1,2,6-hexanetriol. Examples of the polyhydric alcohol derivative include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-n-butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol-n-propyl ether, diethylene glycol-n-butyl ether, diethylene glycol-n-hexyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol-n-propyl ether, triethylene glycol-n-butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol-n- Propyl ether, propylene glycol-n-butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol-n-propyl ether, tripropylene glycol-n-butyl ether and the like. Examples of the alcohol include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, isobutyl alcohol, tert-butyl alcohol and benzyl alcohol. Examples of the amide include dimethylformamide and dimethylacetamide. Examples of the ketone include acetone and the like. Examples of the ketoalcohol include diacetone alcohol and the like. Examples of the ether include tetrahydrofuran and dioxane. Examples of the nitrogen-containing solvent include pyrrolidone, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, triethanolamine and the like. Examples of the sulfur-containing solvent include thiodiethanol, thiodiglycol, thiodiglycerol, sulfolane, dimethylsulfoxide and the like.

The pretreatment agent can be prepared, for example, by uniformly mixing the aqueous polymer, the cross-linking agent, and, if necessary, other additive components by a conventionally known method. The pretreatment agent may be prepared, for example, by removing insoluble matter with a filter or the like after the mixing.

Next, a set of the ink and the pretreatment agent of the present invention will be described. A set of an ink and a pretreatment agent of the present invention is a set of an ink and a pretreatment agent used for forming an image on a fabric, wherein the ink contains a colorant and a component having a carboxyl group, and the pretreatment agent is the pretreatment agent of the present invention. As described above, the ink is characterized by containing a colorant and a component having a carboxyl group, and other configurations are not particularly limited. For example, the ink may contain water, or may contain a colorant, a component containing a carboxyl group, and a component other than water. As the ink, for example, pigment ink, dye ink, or the like can be used, and pigment ink is preferably used. The inks may include five colors of white, yellow, magenta, cyan and black, for example.

The white ink may contain, for example, a white pigment composed of hollow particles or non-hollow particles (non-hollow particles; also referred to as solid particles) as a colorant. For the white ink, for example, the hollow particles and the non-hollow particles may be used in combination as the white pigment.

Examples of the hollow particles include "SX-866 (B)" (styrene-acrylic dispersion, pigment solids content 20% by weight, primary particle diameter 0.3 μm) and "SX-868 (B)" (styrene-acrylic dispersion, pigment solids content 20% by weight, primary particle diameter 0.5 μm) manufactured by JSR Corporation; Styrene-acrylic dispersion, pigment solid content 30% by weight, primary particle size 0.4 μm); Nippon Zeon Co., Ltd. “NIPOL (registered trademark) V1004” (modified styrene-butadiene dispersion, pigment solids content 50% by weight, primary particle size 0.3 μm), “NIPOL (registered trademark) MH8055” (styrene-acrylic dispersion, pigment solid content 30% by weight, primary particle size 0.8 μm) and “NIPOL (registered trademark) MH5055” (styrene-acrylic dispersion, pigment solid content 30% by weight, primary particle diameter 0.5 μm); In addition, the said primary particle diameter represents a volume average particle diameter.

Examples of the non-hollow particles include highly shielding white pigments such as titanium oxide, silicon oxide, zinc oxide, aluminum oxide, magnesium oxide, barium sulfate, and calcium carbonate.

The white ink may, for example, further contain a polymer dispersant obtained by neutralizing an anionic water-soluble resin with a basic compound. Examples of the anionic water-soluble resin include, for example, one or more of carboxyl group-containing unsaturated monomers (including acid anhydride group-containing unsaturated monomers that open the ring to give a carboxyl group) such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, maleic acid monoalkyl ester, citraconic acid, citraconic anhydride, and citraconic acid monoalkyl ester; styrene monomers such as styrene, α-methylstyrene, and vinyltoluene; A copolymer obtained by reacting a mixture with one or more of unsaturated monomers selected from aralkyl methacrylates such as acrylates or alkyl methacrylates such as acrylates such as acrylates, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate and lauryl acrylate, or acrylates, preferably monomers selected to have a glass transition temperature of 0°C to 80°C. and a copolymer obtained by reacting a mixture of the two. Examples of the basic compound include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and organic basic compounds such as triethylamine, monoethanolamine, triethanolamine and triethylenediamine.

The amount of the polymer dispersant used is, for example, 10 to 40 parts by weight, or 15 to 30 parts by weight, with respect to 100 parts by weight of the white pigment.

The white ink, for example, further contains a component containing a carboxyl group. The component containing the carboxyl group may be, for example, a resin component such as a urethane resin emulsion, an acrylic resin emulsion, or a styrene resin emulsion. The resin component may be any one containing a carboxyl group, and the acid value of the resin is, for example, 1 mgKOH/g to 300 mgKOH/g. Moreover, the form of the resin component containing a carboxyl group is not limited, and for example, it may be contained in a resin alone or as a resin emulsion.

The total solid content of the white pigment, the polymer dispersant, the resin component, the nonionic resin emulsion and the anionic resin emulsion is, for example, 25% to 45% by weight in the total amount of the white ink.

The white ink may also contain, for example, a moisturizing agent, a surfactant, a pH adjuster, a viscosity adjuster, a surface tension adjuster, an antiseptic, an antifungal agent, and the like. The moisturizing agent contributes, for example, to preventing drying of the white ink. Examples of the moisturizing agents include keto alcohols such as diacetone alcohol; polyalkylene glycols; polyhydric alcohols such as alkylene glycols, glycerin and trimethylolpropane; Examples of the polyalkylene glycol include polyethylene glycol and polypropylene glycol. Examples of the alkylene glycol include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, thiodiglycol and hexylene glycol. One type of these moisturizing agents may be used alone, or two or more types may be used in combination. Among these, polyhydric alcohols such as alkylene glycol and glycerin are preferred. The content of the humectant in the total amount of the ink is, for example, 0 wt % to 60 wt %, 3 wt % to 50 wt %. The surfactant contributes, for example, to adjusting the surface tension of the white ink and improving the dispersibility of the white pigment. One type of the surfactant may be used alone, or two or more types may be used in combination.

Next, the pretreatment agent application device of the present invention will be described. A pretreatment agent application device of the present invention is a pretreatment agent application device that applies a pretreatment agent to a fabric before ink is applied to the fabric when an image is formed on the cloth, and includes a platen and pretreatment agent application means for applying the pretreatment agent to the fabric, wherein the pretreatment agent includes an aqueous polymer that does not substantially contain a carboxyl group, and a cross-linking agent that can be crosslinked with the carboxyl group of a component contained in the ink.

The platen may have, for example, the same configuration as the platen of the inkjet recording apparatus shown in FIG. 2, which will be described later.

Examples of the pretreatment agent application means include a liquid ejection means such as a liquid ejection head, a spray, a stamp, a brush, a roller, and the like.

The pretreatment agent in the pretreatment agent application device of the present invention is the same as the pretreatment agent of the present invention described above, and the description thereof can be used.

Next, the image forming method of the present invention will be described. An image forming method of the present invention is an image forming method for forming an image on a fabric, and comprises a pretreatment step of applying a pretreatment agent to the fabric, and an image printing step of printing an image using ink on a portion to which the pretreatment agent is applied, and in the pretreatment step, the pretreatment agent of the present invention is used as the pretreatment agent.

The image forming method of the present invention may have, for example, a heat treatment step, a compression step, a heat fixing step, etc., which will be described later, in addition to the above two steps.

In the pretreatment step, the pretreatment agent can be applied by, for example, an inkjet method, a spray method, a stamp application, a brush application, a roller application, a padding method, or the like.

In the pretreatment step, the pretreatment agent may be applied to the entire image forming surface of the fabric or to a portion thereof. When the pretreatment agent is applied to a part of the fabric, the pretreatment agent-applied part is at least substantially the same area as the ink-printed portion on the image forming surface of the fabric. When applying the pretreatment agent to a part, the size of the pretreatment agent applying part should be larger than the printed part. For example, as shown in FIG. 1(a), when printing a character (X) on a fabric (a T-shirt in this example) 100, it is preferable to apply the pretreatment agent so as to form a pretreatment agent application portion 110 with a line width larger than the line width of the character. Further, as shown in FIG. 1B, when a pattern is printed on a fabric (T-shirt) 100, the pretreatment agent is preferably applied so as to form a pretreatment agent application portion 120 larger than the pattern.

The image forming method of the present invention may include, after the pretreatment step, at least one of a heat treatment step of heat-treating the portion to which the pretreatment agent is applied and a compression step of compressing the portion to which the pretreatment agent is applied. The heat treatment can be performed using, for example, a commercially available hot press machine, oven, belt conveyor oven, or the like. When the hot press machine is used, the heat treatment is preferably performed in a state in which a Teflon (registered trademark) sheet having a smooth surface is placed on the portion to which the pretreatment agent is applied. As a result, fluffing of the fabric can be suppressed, and, for example, when the image printing step is performed after this step, the implementation becomes smoother. Although the temperature of the heat treatment is not particularly limited, it is, for example, 160.degree. C. to 185.degree. The compression can be performed, for example, using a commercially available hot press under the same conditions as the heat treatment.

Next, the image printing step is a step of printing an image using ink on the portion to which the pretreatment agent is applied.

It is preferable that the image printing step includes a base portion forming step of forming a base portion using a first ink on the portion to which the pretreatment agent is applied, and an image forming step of forming an image on the base portion using a second ink. It is preferable to use a white ink as the first ink and a color ink as the second ink. According to this aspect, it is possible to form a color image with excellent coloring even on a fabric having a dark background color.

The image printing process can be performed using, for example, an inkjet recording apparatus shown in FIG. As shown in FIG. 2, the inkjet recording apparatus 30 includes an inkjet printer 31 that ejects ink onto a fabric to record a desired image, and a recording control device 70 that acquires image data of the desired image and controls the inkjet printer 31, which are connected via an interface.

The inkjet printer 31 has a frame-like frame 52 as shown in FIG. The frame 52 has a horizontal portion 52h positioned at the bottom of the printer 31 and two vertical portions 52v vertically rising from both ends of the horizontal portion 52h. In FIG. 3, the same parts as in FIG. 2 are denoted by the same reference numerals, and the same applies to the drawings from FIG. 4 onward.

A slide rail 53 is horizontally supported so as to connect the upper portions of the two vertical portions 52v. A carriage 54 is provided on the slide rail 53 so as to be slidable along the longitudinal direction (main scanning direction) of the slide rail 53 . The lower surface of the carriage 54 is provided with five piezoelectric inkjet heads (ink ejecting means) 55 arranged for each color to eject five colors of ink.

Pulleys 56 and 57 are supported respectively on the upper portions of the two vertical portions 52v, and one pulley 56 is connected to the motor shaft of a motor 58 supported by the vertical portion 52v. An endless belt 59 is stretched between the pulleys 56 and 57, and the carriage 54 is fixed to an appropriate portion of the endless belt 59. As shown in FIG.

With such a configuration, when one of the pulleys 56 is rotated forward and backward by driving the motor 58, the carriage 54 is linearly reciprocated along the longitudinal direction (main scanning direction) of the slide rail 53, and as a result, the inkjet head 55 is reciprocated.

Mounting portions 50 for detachably mounting the ink cartridges 60 are formed on the two vertical portions 52v, respectively. One of the two mounting portions 50 can be loaded with ink cartridges 60 for two colors and the other for three colors. An ink bag (not shown) formed inside the ink cartridge 60 is connected by a flexible tube 62 to five ink tanks 61 positioned above each of the inkjet heads 55. In addition, since the five ink tanks 61 communicate with the inkjet head 55 as described later, ink is supplied from the ink cartridge 60 to the inkjet head 55 .

A slide mechanism 41 as a conveying means is installed on the horizontal portion 52 h of the frame 52 , and a platen (support) 42 is supported on the slide mechanism 41 . The platen 42 is provided with a fixing frame (fixing means) 45 so that the cloth such as a T-shirt can be positioned so that its recording portion is on the upper surface and can be set in a taut, wrinkle-free and flat state. Also, in the inkjet printer 31 of this example, the number of platens 42 is one. However, in the present invention, the number of platens is not limited to one, and can be increased as required.

A platen transport mechanism (not shown) is provided to reciprocate the platen 42 in the direction perpendicular to the plane of FIG. 3 (the sliding direction of the slide mechanism 41 and the sub-scanning direction of the inkjet printer 31). For the platen transport mechanism, for example, a rack and pinion mechanism, a mechanism using an endless belt, or the like can be applied.

FIG. 4 shows a state in which the cloth is set on the platen. FIG. 4(a) is a plan view, and FIG. 4(b) is a cross-sectional view taken along the line AA in FIG. 4(a). As shown in FIG. 4, the platen 42 has a rectangular shape extending in the sub-scanning direction when viewed from above, and has a support surface 46 for supporting the T-shirt 100 . The lower surface of the platen 42 on the far side in the direction perpendicular to the paper surface of FIG.

The fixed frame 45 is configured such that a frame having an L-shaped cross section covers four sides of the support surface 46 of the platen 42 . An opening 45 a having an opening area slightly smaller than the area of the support surface 46 of the platen 42 is formed in the surface of the fixed frame 45 facing the support surface 46 of the platen 42 . When setting the T-shirt 100 on the platen 42 , the support surface 46 of the platen 42 is covered from the hem side of the T-shirt 100 and fixed by the fixing frame 45 . The fixed frame 45 is rotatable by a rotating portion (not shown) provided at the end of the platen 42 on the back side in the direction perpendicular to the plane of FIG.

The inkjet printer 31 also includes a cover 43 that covers the inkjet head 55, the slide mechanism 41, and the like. In addition, in FIG. 3, the cover 43 is drawn in a two-dot chain line and shown in perspective. An operation panel 44 having a liquid crystal panel and operation buttons is arranged on the upper right portion of the front surface of the cover 43 .

The five inkjet heads 55 shown in FIG. 3 correspond to five colors of ink (white, yellow, magenta, cyan, and black) and are arranged side by side along the reciprocating direction of the carriage 54, and communicate with the corresponding ink cartridges 60 via flexible tubes 62 and ink tanks 61. As a configuration for supplying ink to the inkjet head, for example, a conventionally known configuration can be used (see, for example, JP-A-2004-291461). Note that the five inkjet heads 55 may be arranged such that a head unit having ejection portions for ejecting four colors of ink (yellow, magenta, cyan, and black) and a head unit having ejection portions for ejecting white ink are arranged side by side in the sub-scanning direction. In addition to the five inkjet heads 55, the inkjet printer 31 may further include liquid ejection means as means for applying the pretreatment agent to the fabric in advance. Further, the inkjet printer 31 may include means for applying the pretreatment agent to the fabric in advance, such as a spray.

The ink jet head 55 is arranged so that its lower surface forms a small gap with the supporting surface 46 of the platen 42, and when recording an image on the T-shirt 100, the recorded portion of the T-shirt 100 set on the platen 42 is conveyed to the gap. With this configuration, the inkjet head 55 is reciprocated by the carriage 54 and ejects each color of ink onto the T-shirt 100 from a large number of small-diameter ejection nozzles formed on the bottom surface of the inkjet head 55 . As a result, the ejected ink of each color is retained on the surface of the fabric. As a result, a desired color image is printed on the T-shirt 100. FIG.

The recording control device 70 shown in FIG. 2 is configured using, for example, a general-purpose personal computer (PC), and includes a main body 71, a display as a display unit 72, and a keyboard 73 and a mouse (pointing device) 74 as an operation unit 75.

FIG. 5 is a block diagram showing the configuration of the recording control device 70 shown in FIG. The recording control device 70 includes a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, an HD (Hard Disk) 84, an operation section 75, a display section 72, and an interface (I/F) 85, which are interconnected via a bus. .

Various programs used to control the operation of the recording control device 70 are stored in the HD 84 . The HD 84 also stores various image data downloaded from the Internet or created by software, and various data for each type of fabric such as T-shirts. The CPU 81 performs processing such as various calculations based on signals input by the operation unit 75 and various programs and data in the ROM 82, RAM 83 and HD 84. FIG. Then, data and the like are transmitted to the inkjet printer 31 via the interface 85 . The RAM 83 is a readable/writable volatile storage device, and stores various calculation results and the like in the CPU 81 . The interface 85 is connected to the interface of the inkjet printer 31 and enables communication between the recording control device 70 and the inkjet printer 31 .

Recording of a desired image on the T-shirt 100 using the inkjet recording apparatus 30 of this embodiment can be carried out, for example, as follows. First, image data to be printed on the T-shirt 100 is acquired through the keyboard 73 and mouse 74 of the printing control device 70 . In obtaining the image data, the software installed in the recording control device 70 is used to create the image data, or the image data stored in the HD 84 in advance is selected.

Next, T-shirt 100 is fixed to platen 42 . That is, the T-shirt 100 is put over the platen 42 from its hem and fixed with the fixing frame 45 along the supporting surface 46 of the platen 42 without wrinkles.

Next, when the user gives an instruction to perform printing, the image data is sent to the inkjet printer 31 via the interface 85, ink is ejected from the inkjet head 55 based on this image data, and printing is performed on the T-shirt 100 fixed to the platen 42.

Next, the image forming method of the present invention may have a heat fixing step of thermally fixing the ink to the fabric by heat-treating the printed portion of the fabric after the image printing step. The heat fixing step can be performed, for example, using the same apparatus and under the same conditions as the heat treatment. Further, the heat fixing process can be carried out, for example, using the apparatus described in JP-A-2009-209493. According to this apparatus, the fabric can be heated at 180° C. and pressurized.

Next, a method for producing the fabric of the present invention will be described. A method for producing a fabric of the present invention is a method for producing a fabric having an image, and is characterized by having a step of forming an image on the fabric by the image forming method of the present invention.

According to the image forming method and the fabric manufacturing method of the present invention, it is possible to obtain a fabric excellent in appearance and excellent in washing fastness of the image forming part because traces of application of the pretreatment agent can be easily removed by washing.

Next, examples of the present invention will be described together with comparative examples. In addition, the present invention is not limited or restricted by the following examples and comparative examples.

[Example 1-1 and Comparative Examples 1-1 to 1-3]
By stirring and mixing each component in the pretreatment agent composition (Table 1), the pretreatment agents of Example 1-1 and Comparative Examples 1-1 to 1-3 shown in Table 1 were obtained.

Using the pretreatment agents of Example 1-1 and Comparative Examples 1-1 to 1-3, an image was formed on a black T-shirt (material: 100% cotton) by the following steps.

(Pretreatment step)
The pretreatment agent was diluted with water so as to be 3 times its weight, and applied to the image forming surface of the T-shirt using a sprayer. The applied amount of the pretreatment agent was 0.02 g/cm ² .

(Heat treatment process)
After the pretreatment step, the portion of the T-shirt to which the pretreatment agent was applied was subjected to heat treatment for 35 seconds using a heat press set at 180°C.

(Image printing process)
A garment printer manufactured by Brother Industries, Ltd. was used to print the letter (A) on a T-shirt by ejecting ink. As the ink, an aqueous dispersion (aqueous white ink) containing 1% to 25% by weight of a pigment, 1% to 30% by weight of a resin having a carboxyl group, 0% to 60% by weight of a moisturizing agent, and 0% to 2% by weight of a surfactant is used as the white ink forming the base portion in the portion to which the pretreatment agent is applied. An aqueous dispersion (aqueous color ink) containing 0% to 60% by weight and 0% to 2% by weight of a surfactant was used.

(Heat fixing process)
After the image printing process, the white ink was heat-fixed to the printed portion of the T-shirt using an oven set at 160°C. The heating time in the heat fixing was set to 3.5 minutes.

For the pretreatment agents of Example 1-1 and Comparative Examples 1-1 to 1-3, (a) evaluation of storage stability, (b) evaluation of easiness of removal of traces of application of pretreatment agent, and (c) evaluation of washing fastness of image forming part were carried out by the following methods.

(a) Storage stability evaluation A pretreatment agent (not diluted with water) was placed in a glass container, stored in an environment of 60 ° C. for 336 hours, and the viscosity change rate and appearance change before and after storage were evaluated according to the following evaluation criteria. The viscosity before and after storage was measured at 25° C. using a rotational viscometer DV-II+ manufactured by Brookfield Co., and the rate of change was calculated according to the following formula.

Δη=100×(ηa−ηb)/ηb
ηa: Viscosity before storage (mPa s)
ηb: Viscosity after storage (mPa s)

Evaluation of Storage Stability Evaluation Criteria A: Viscosity change rate before and after storage was less than 5%.
B: The viscosity change rate before and after storage was 5% or more and less than 10%.
C: The viscosity change rate before and after storage was 10% or more.
*: A fine precipitate was observed after storage, but the level was practically acceptable.

(b) Evaluation of easiness of removal of traces of application of pretreatment agent An evaluation sample was obtained as follows. That is, first, water was applied using a spray to the image forming surface of the T-shirt after the heat fixing process. The amount of water applied was 0.02 g/cm ² . After applying the water, the T-shirt was dried using an oven set at 160°C. The heating time for the drying was 3.5 minutes. The L ^* value of the pretreatment agent-applied portion and the non-applied portion of the evaluation sample thus obtained was measured using a CIE1976L ^* a ^* b ^* color space scale colorimeter X-Rite939 manufactured by X-Rite, and ΔL ^* was calculated by the following formula. Based on the calculated ΔL ^* , the easiness of removal of traces of application of the pretreatment agent was evaluated according to the following evaluation criteria. It can be judged that the smaller ΔL ^* is, the more the pretreatment agent is removed by the application of water instead of washing, the traces of application of the pretreatment agent are less noticeable, and the appearance is superior.

ΔL ^* =L ^* 1−L ^* 2
L ^* 1: L ^* value of pretreatment agent-applied portion L ^* 2: L ^* value of pretreatment agent-unapplied portion

Evaluation of ease of removal of pretreatment agent traces Evaluation criteria A: ΔL ^* is less than 1 B: ΔL ^* is 1 or more and less than 1.5 C: ΔL ^* is 1.5 or more

(c) Evaluation of Washing Fastness of Image Forming Area The T-shirt was washed according to the US standard AATCC 61 II A method, and the washing fastness of the image forming area was evaluated according to the following evaluation criteria.

Evaluation of Washing Fastness of Image Forming Area Evaluation Criteria G: Washing grade was grade 3, grade 3-4, grade 4, grade 4-5 or grade 5.
NG: The washing grade was grade 1, grade 1-2, grade 2 or grade 2-3.

Table 1 shows the compositions and evaluation results of the pretreatment agents of Example 1-1 and Comparative Examples 1-1 to 1-3.

As shown in Table 1, in Example 1-1, the storage stability, easiness of removal of traces of application of the pretreatment agent, and washing fastness of the image forming portion were all evaluated to be good. On the other hand, in Comparative Examples 1-1 and 1-3, in which no cross-linking agent capable of cross-linking the carboxyl groups of the components contained in the ink was used, the results of evaluation of fastness to washing in the image forming portion were poor. In Comparative Example 1-2 using a water-soluble polymer containing a carboxyl group, the evaluation results of storage stability and easiness of removing traces of application of the pretreatment agent were poor.

[Example 2-1]
Storage stability, ease of removal of pretreatment agent traces and wash fastness of the image forming part were evaluated in the same manner as in Example 1-1, except that vinyl acetate emulsion resin, which is a water-insoluble polymer, was used instead of polyvinylpyrrolidone, which is a water-soluble polymer containing no carboxyl group, as the aqueous polymer, and compared with the evaluation results of Example 1-1.

Table 2 shows the compositions and evaluation results of the pretreatment agents of Examples 1-1 and 2-1.

As shown in Table 2, when the evaluation results of Examples 1-1 and 2-1 are compared, Example 1-1 using a water-soluble polymer as the aqueous polymer was superior to Example 2-1 using a water-insoluble polymer in terms of the ease of removal of traces of application of the pretreatment agent.

[Examples 3-1 and 3-2]
A pretreatment agent of Example 3-1 was obtained in the same manner as in Example 1-1, except that the content of the oxazoline group-containing compound as a cross-linking agent before dilution with water was 0.15% by weight. Further, a pretreatment agent of Example 3-2 was obtained in the same manner as in Example 3-1, except that a cross-linking agent containing no oxazoline group was used instead of the oxazoline group-containing compound. The pretreatment agents of Examples 3-1 and 3-2 were evaluated in terms of storage stability, easiness of removal of traces of application of the pretreatment agent, and washing fastness of the image forming area, and compared with the evaluation results of Comparative Example 1-1.

Table 3 shows the compositions and evaluation results of the pretreatment agents of Examples 3-1, 3-2 and Comparative Example 1-1.

As shown in Table 3, in Examples 3-1 and 3-2, the storage stability, easiness of removal of traces of application of the pretreatment agent, and washing fastness of the image forming portion were all evaluated to be good. Comparing the evaluation results of Examples 3-1 and 3-2, Example 3-1 using an oxazoline group-containing compound as a cross-linking agent used an aqueous cross-linking agent in which a hydrophilic segment was imparted to a polycarbodiimide resin. On the other hand, as described above, Comparative Example 1-1, which did not use a cross-linking agent capable of cross-linking with the carboxyl groups of the components contained in the ink, gave a poor evaluation result of the washing fastness of the image forming portion.

[Examples 4-1 to 4-7]
In the same manner as in Example 1-1, Example 3-1, and Comparative Example 1-1, except that the content of the oxazoline group-containing compound as a cross-linking agent was changed, the storage stability, the ease of removal of traces of application of the pretreatment agent, and the washing fastness of the image forming part were evaluated, and compared with the evaluation results of Example 1-1, Example 3-1, and Comparative Example 1-1. In addition, the pretreatment agents of Examples 1-1, 3-1 and 4-4 to 4-7 and Comparative Example 1-1 were evaluated for (d) storage stability (discoloration) by the following method.

(d) Evaluation of storage stability (discoloration) A pretreatment agent (not diluted with water) was placed in a glass container and stored in an environment of 70°C for 72 hours. An evaluation sample was obtained by diluting the pretreatment agent before and after storage so that the weight was tripled with water, and the L ^* value, a ^* value and b ^* value were measured using a spectrophotometer CM-3700d manufactured by Minolta, and the color difference ΔE ^* ab was calculated by the following formula and evaluated according to the following evaluation criteria.

ΔE ^* ab={( _L1 ^* _-L2 ^* ) ²⁺ ( _a1 ^* _-a2 ^* ) ²⁺ ( _b1 ^* _-b2 ^* ) ² } ^1/2
_L1 ^* : L ^* value of the evaluation sample before storage L2 ^* : L ^* value of the evaluation sample after storage _a1 *: a ^{* value of the evaluation sample before storage a2*: a* value of the evaluation sample after storage b1*: b* value of the evaluation sample before storage b2*} _: ^{b *} _value ^{of the} _evaluation ^{sample after} _storage

Storage stability (discoloration) evaluation Evaluation criteria A: ΔE ^* ab is less than 1 B: ΔE ^* ab is 1 or more and less than 3 C: ΔE ^* ab is 3 or more

Table 4 shows the compositions and evaluation results of the pretreatment agents of Examples 1-1, 3-1 and 4-1 to 4-7 and Comparative Example 1-1.

As shown in Table 4, in Examples 1-1, 3-1, and 4-1 to 4-7 in which the content of the cross-linking agent was 1 part by weight or more with respect to 100 parts by weight of the aqueous polymer, the washing fastness evaluation results of the image forming part were good. Further, in Examples 1-1, 3-1 and 4-1 to 4-4 in which the content ratio of the cross-linking agent to 100 parts by weight of the aqueous polymer was 100 parts by weight or less, the content ratio exceeded 100 parts by weight Examples 4-5 to 4-7, the evaluation results of storage stability (discoloration) and ease of removal of pretreatment agent traces were more excellent. In Examples 4-1 to 4-3, storage stability (discoloration) evaluation was not performed, but discoloration depends on the content of the cross-linking agent, and the storage stability (discoloration) evaluation result of Examples 4-1 to 4-3 was estimated to be "A".

[Reference Examples 5-1 to 5-5]
The storage stability, ease of removal of pretreatment agent traces, and washing fastness of the image forming part were evaluated in the same manner as in Example 1-1, except that the content of the aqueous polymer was changed and the moisturizing agent and the cross-linking agent were not used.

Table 5 shows the compositions and evaluation results of the pretreatment agents of Example 1-1 and Reference Examples 5-1 to 5-5.

As shown in Table 5, in Reference Examples 5-1 to 5-5, since no cross-linking agent was used, the evaluation results of the washing fastness of the image forming part were poor.

As described above, the pretreatment agent of the present invention can easily remove traces of application without impairing the washing fastness of the image forming area, and is excellent in storage stability. The use of the pretreatment agent of the present invention is not particularly limited, and it can be widely applied to pretreatment before image formation on various fabrics.

30 inkjet recording device 31 inkjet printer 42 platen (support)
45 Fixing means 46 Support surface 54 Carriage 55 Ink ejection means (inkjet head)
60 ink cartridge 70 recording control device 71 main body 72 display unit 73 keyboard 74 mouse 100 T-shirt 110, 120 processing agent applying unit

Claims (4)

A pretreatment agent that is applied to the fabric before the ink when forming an image on the fabric,
an aqueous polymer substantially free of carboxyl groups (excluding cationic aqueous polymers);
a cross-linking agent capable of cross-linking the carboxyl groups of components contained in the ink;
including
A pretreatment agent, wherein the aqueous polymer is polyvinylpyrrolidone. A pretreatment agent that is applied to the fabric before the ink when forming an image on the fabric,
an aqueous polymer substantially free of carboxyl groups (excluding cationic aqueous polymers);
a cross-linking agent capable of cross-linking the carboxyl groups of components contained in the ink;
including
A pretreatment agent characterized in that, when used, the content of the aqueous polymer in the total amount of the pretreatment agent is 0.1% by weight to 0.5% by weight. A pretreatment agent applying device for applying a pretreatment agent to the fabric before ink is applied when forming an image on the fabric,
a platen;
pretreatment agent application means for applying the pretreatment agent to the fabric;
including
comprising the pretreatment agent,
3. A pretreatment agent application device, wherein the pretreatment agent is the pretreatment agent according to claim 1 or 2 . An image forming method for forming an image on a fabric,
A pretreatment step of applying a pretreatment agent to the fabric;
an image printing step of printing an image using ink on the portion to which the pretreatment agent is applied;
has
3. An image forming method, wherein the pretreatment agent according to claim 1 is used as the pretreatment agent in the pretreatment step.

Images