Inkjet textile printing method and inkjet textile printing device

Abstract

To provide an inkjet textile printing method and an inkjet textile printing apparatus that form an image by a multipath method and are capable of reducing a difference of density in a printed part on a front surface and a reverse surface of a fabric, the difference being caused by an order of application of a treatment liquid and inks.SOLUTION: An inkjet textile printing method according to the present invention applies, by an inkjet head, a treatment liquid for retaining inks on a surface of a fabric, wherein the inkjet head for ejecting the treatment liquid and the inkjet heads for ejecting the inks are arranged on a same carriage and form an image by a multipath method, a forward path applies the inks after applying the treatment liquid, a backward path applies the treatment liquid after applying the inks, and conditions for controlling a degree of penetration of the inks into the fabric are changed in the forward path and the backward path.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an inkjet textile printing method and an inkjet textile printing apparatus, and more particularly to an inkjet textile printing method that can reduce the density difference in the printed area on the front and back sides of a fabric due to the order in which a treatment liquid and ink are applied while forming an image using a multi-pass method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, an inkjet printing method using an inkjet recording apparatus (textile printing apparatus) has been used as a method for forming images such as characters, pictures, and designs on fabrics such as woven fabrics and nonwoven fabrics. In such inkjet printing methods, a pretreatment liquid is usually used to aggregate the color ink (hereinafter, also simply referred to as "ink") and retain the ink on the fabric surface, thereby improving color density. In addition, by continuously performing the process of applying the pretreatment liquid and the process of applying the ink and dyeing, it is possible to improve productivity and color development stability. Furthermore, by applying the pretreatment liquid using an inkjet head and arranging it on the same carriage as the inkjet head for ink ejection, there are advantages in that the pretreatment liquid can be applied only to the parts of the image printing section that require it, and that the size can be reduced.

[0003] For example, Patent Document 1 discloses a technology in which a treatment liquid containing an anti-bleeding agent can also be ejected from the inkjet head, and the amount of the treatment liquid ejected is controlled together with the reactive dye ink so that the concentration of the treatment liquid is controlled according to the color density of the image to be printed.

[0004] Incidentally, in the multi-pass method (also called the "scan method") in which the head carriage moves, in order to reduce individual differences in the head, it is common to break down the image into passes and form the image by moving back and forth multiple times horizontally to the transport direction of the fabric to be printed. However, if the treatment liquid (also called "pre-treatment liquid") and ink are placed in the same carriage, the back and forth movement of the carriage will reverse the application order of the treatment liquid and ink. This causes a problem in that the density on the front surface and the back surface of the fabric change depending on whether the treatment liquid is applied first and then the ink is applied, or whether the ink is applied first and then the treatment liquid is applied. To improve this, it is conceivable to provide a structure in which heads for the pretreatment liquid are provided on both sides of the carriage, but this would result in problems such as an increase in the size and cost of the device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-43375 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above problems and circumstances, and its problem to be solved is to provide an inkjet printing method and inkjet printing apparatus that can form an image using a multi-pass method while reducing the density difference in the printed area on the front and back sides of a fabric that occurs due to the order in which the treatment liquid and ink are applied. [Means for solving the problem]

[0007] In the course of investigating the causes of the above problems in order to solve the above-mentioned problems, the inventors discovered that it is possible to provide an inkjet textile printing method and inkjet textile printing apparatus that can reduce the difference in density of printed areas on the front and back sides of a fabric due to the order in which the treatment liquid and ink are applied, by changing the conditions for controlling the penetration degree of the ink into the fabric in the forward and return passes in a multi-pass method, and thus arrived at the present invention. That is, the above-mentioned problems of the present invention are solved by the following means.

[0008] 1. An inkjet printing method in which a treatment liquid that fixes ink to a fabric surface is applied by an inkjet head, the inkjet head that ejects the treatment liquid and the inkjet head that ejects the ink are disposed on the same carriage; An image is formed using a multi-pass method. In the forward path, the treatment liquid is applied, and then the ink is applied. In the return path, the ink is applied, and then the treatment liquid is applied. The control conditions are changed in the return path so as to suppress the penetration of the ink into the fabric, compared to the forward path. 、 As the control condition, a time interval between application of the treatment liquid and the ink on the return path is made shorter than that on the forward path. An ink-jet printing method comprising the steps of:

[0013] 2 Item 1, characterized in that the control conditions can be changed depending on the type of fiber constituting the fabric or the fiber density of the fabric. To The ink-jet printing method according to the present invention.

[0014] 3 When the ink is a water-based ink and the type of fiber constituting the fabric is cotton, Item 1, characterized in that the difference due to the control conditions in the forward and return paths is reduced for fibers other than cotton. To The ink-jet printing method according to the present invention.

[0015] 4 An inkjet printing device that applies a treatment liquid that fixes the ink on the fabric surface using an inkjet head, the inkjet head that ejects the treatment liquid and the inkjet head that ejects the ink are disposed on the same carriage; An image is formed using a multi-pass method. In the forward path, the treatment liquid is applied, and then the ink is applied. In the return path, the ink is applied, and then the treatment liquid is applied. The control conditions are changed in the return path of the scan in a direction that suppresses the penetration of the ink into the fabric compared to the forward path of the scan. 、 As the control condition, a time interval between application of the treatment liquid and the ink on the return path is made shorter than that on the forward path. An ink-jet printing apparatus comprising: Effect of the Invention

[0016] The above-mentioned means of the present invention make it possible to provide an inkjet printing method and an inkjet printing apparatus that can form an image using a multi-pass method while reducing the density difference in the printed area on the front and back sides of a fabric due to the order in which the treatment liquid and ink are applied. Although the mechanism by which the effects of the present invention are manifested or the mechanism by which the effects of the present invention are acted upon has not been clearly understood, it is speculated as follows. In the multi-pass method, on the outbound path, the treatment liquid is applied and then the ink, and on the return path, the ink is applied and then the treatment liquid. Therefore, on the outbound path, the ink reacts with the treatment liquid on the fabric surface before penetrating, causing the ink to coagulate, resulting in a large amount of ink (colorant) present on the surface of the fabric. On the other hand, on the return path, the ink (colorant) penetrates a little before the treatment liquid is applied and then ink (color material) coagulation occurs, so the ink remains further inside the fabric, resulting in a difference in density in the printed area between the forward and return paths. Therefore, in the present invention, by changing the conditions for controlling the degree of penetration of the ink into the fabric on the outward and return paths, it is possible to reduce the difference in the penetration of the ink into the fabric on the outward and return paths, and to reduce the difference in density of the printed area on the front and back sides of the fabric. [Brief description of the drawings]

[0017] [Figure 1] Schematic diagram showing an example of an inkjet textile printing device [Diagram 2] FIG. 1 is a schematic diagram showing an example of a main part of a multi-pass type inkjet coating device. [Diagram 3] Block diagram showing the internal configuration of an inkjet textile printing device DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The inkjet textile printing method of the present invention is an inkjet textile printing method in which an inkjet head applies a treatment liquid that retains the ink on the surface of a fabric, wherein the inkjet head that ejects the treatment liquid and the inkjet head that ejects the ink are arranged on the same carriage, an image is formed using a multi-pass method, the ink is applied after the treatment liquid is applied on the outbound path, and the ink is applied after the treatment liquid is applied on the return path, and the conditions for controlling the penetration degree of the ink into the fabric are changed between the outbound path and the return path. This feature is a technical feature common to or corresponding to each of the following embodiments.

[0019] In an embodiment of the present invention, it is preferable to change the control conditions in the return path in a direction that suppresses the penetration of the ink into the fabric compared to the forward path, in order to further reduce the concentration difference between the front and back surfaces of the fabric.

[0020] As a control condition for suppressing the penetration of the ink, it is preferable to increase the amount of the treatment liquid applied on the return path compared to the outbound path, or to shorten the time interval between the application of the treatment liquid and the ink on the return path compared to the outbound path, in that this reduces the difference in the amount of ink and treatment liquid mixed on the fabric surface on the outbound and return paths.

[0021] In addition, as a method of increasing the amount of treatment liquid applied on the return path compared to the outward path, it is preferable to do at least one of increasing the application area of ​​the treatment liquid on the return path compared to the outward path or increasing the amount of droplets ejected of the treatment liquid, which is easy to control and does not affect productivity.

[0022] It is preferable that the control conditions can be changed depending on the type of fiber constituting the fabric or the fiber density of the fabric, in that the difference in density between the front and back surfaces of the fabric can be further reduced.

[0023] Furthermore, when the ink is a water-based ink and the type of fiber constituting the fabric is cotton, it is preferable to reduce the difference due to the control conditions in the outbound and return paths compared to fibers other than cotton, in that this provides appropriate conditions for cotton, which is prone to leaving treatment liquid on its surface.

[0024] The inkjet textile printing device of the present invention is an inkjet textile printing device that applies a treatment liquid that retains ink on a fabric surface using an inkjet head, the inkjet head that ejects the treatment liquid and the inkjet head that ejects the ink are arranged on the same carriage, an image is formed by a multi-pass method, the ink is applied after the treatment liquid is applied on the outgoing pass, the ink is applied after the ink is applied on the return pass, and the condition for controlling the penetration degree of the ink into the fabric is changed between the outgoing pass and the return pass of the scan. This makes it possible to reduce the density difference of the printed portion on the front and back sides of the fabric due to the order of application of the treatment liquid and the ink while forming an image by the multi-pass method.

[0025] The present invention, its components, and embodiments for carrying out the present invention will be described below. In this application, the symbol "to" is used to mean that the numerical values ​​before and after the symbol "to" are included as lower and upper limits.

[0026] [Inkjet printing device] The ink-jet printing apparatus of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto. FIG. 1 is a schematic diagram showing an example of the ink-jet textile printing apparatus of the present invention.

[0027] As shown in FIG. 1, the inkjet printing apparatus (hereinafter also simply referred to as the "printing apparatus") 100 of the present invention includes a fabric pay-out section 101 that pays out the fabric T1, a transport section 103 that transports the fabric, an application section 10 that applies treatment liquid Pr and ink In to the fabric T1, a drying section 105 that dries the treatment liquid Pr, the ink In, etc., a fabric recovery section 102 that recovers the printed fabric T3 (hereinafter also referred to as the "printed fabric T3"), and a control section 106 that controls each component. Furthermore, in the textile printing apparatus 100 of the present invention, the coating section 10 includes a treatment liquid head (treatment liquid inkjet head, 1Pr in FIG. 2) that ejects treatment liquid Pr, an ink head (inkjet head for ink, 1Y, 1M, 1C, and 1K in FIG. 2) that ejects ink In, and one carriage 22 that carries the treatment liquid head 1Pr and the ink heads (1Y, 1M, 1C, and 1K), and forms an image by a multi-pass method. That is, the treatment liquid head 1Pr and the ink heads (1Y, 1M, 1C, and 1K) are carried on the same carriage 22.

[0028] In Fig. 1, the transport direction of the fabric T1 is indicated by an arrow. In the printing apparatus 100, essential components are a treatment liquid head 1Pr, ink heads (1Y, 1M, 1C, and 1K), and a control unit 106. The printing apparatus 100 may have other components in addition to the components shown in Fig. 1 as necessary. Examples of other components include a fixing unit (not shown) provided downstream of the drying unit 105 in the transport direction. Each of the components of the textile printing apparatus 100 will now be described.

[0029] <Fabric payout section> The fabric T1 is placed in a fabric pay-out unit 101 provided on the upstream side of the application unit 10 in the conveying direction. The fabric pay-out unit 101 includes a rotating shaft on which the roll-shaped fabric T1 is attached, and a motor (not shown) that drives the rotating shaft to rotate in a predetermined rotation direction. The fabric pay-out unit 101 pays out the fabric T1 downstream in the conveying direction along the rotation of the rotating shaft by driving the motor. The fabric T1 may be a continuous fabric as described above, or may be a fabric separated into individual pieces.

[0030] <Transportation section> The conveying section 103 conveys the fabric T1 paid out from the fabric pay-out section 101. In the configuration shown in Fig. 1, the fabric T1 is conveyed by conveying rollers, but for example, the fabric T1 may be attached to a conveying belt and conveyed.

[0031] <Application section> The coating unit 10 performs a process of coating the fabric T1 with the treatment liquid Pr and the ink In, and is specifically a multi-pass type inkjet coating device. FIG. 2 is a diagram showing a schematic diagram of an example of a main part of a multi-pass type inkjet coating device. As shown in FIG. 2, an image is formed by moving a droplet ejection means 20 of an inkjet coating device in a scanning direction X (hereinafter also referred to as the "X direction") onto fabric T1 while ejecting ink of each color In (yellow ink Y, magenta ink M, cyan ink C, and black ink K) and treatment liquid Pr. The fabric T1 is sequentially transported by a transport means (not shown) in a direction Y (hereinafter also referred to as the "transport direction Y" or "Y direction") perpendicular to the scanning direction X, so that an image can be formed on substantially the entire surface (image forming surface) of the fabric T1.

[0032] The droplet ejection means 20 has a treatment liquid head 1Pr, a yellow ink head 1Y, a magenta ink head 1M, a cyan ink head 1C, and a black ink head 1K (hereinafter, these are also collectively referred to as "head units 1"), and a carriage 22 for disposing and holding the head units 1 along the scanning direction X. That is, the treatment liquid head 1Pr and each of the ink heads 1Y, 1M, 1C, and 1K are mounted on the same carriage 22. The head unit 1 is arranged in the following order from the head of the scanning direction in the forward pass, in which the droplet ejection means 20 moves once in the scanning direction X: the treatment liquid head 1Pr, the yellow ink head 1Y, the magenta ink head 1M, the cyan ink head 1C, and the black ink head 1K. Conversely, in the return pass, the head unit 1 is arranged in the following order from the head of the scanning direction: the black ink head 1K, the cyan ink head 1C, the magenta ink head 1M, the yellow ink head 1Y, and the treatment liquid head 1Pr.

[0033] Each head has a surface (nozzle surface) facing the surface of the fabric T1, on which a plurality of nozzles (not shown) are arranged along a transport direction Y perpendicular to the scanning direction X, and minute droplets are ejected from these nozzles by applying an appropriate pressure to the ink In and the treatment liquid Pr. The droplet ejection means 20 is supported in a state in which the nozzle surface of the head unit 1 is spaced a predetermined distance from the surface of the fabric T1 in a direction perpendicular to the surface (height direction).

[0034] The droplet discharge means 20 is scanned in the scanning direction X by the scanning unit 30. The scanning unit 30 includes, for example, rails that support the carriage 22 with the nozzle surface spaced apart from the surface of the fabric T1 in the height direction by the above-mentioned predetermined distance, and allows the carriage 22 to move along the rails that extend along the scanning direction X.

[0035] When the droplet ejection means 20 moves once in the scanning direction X on the outward path, the application of each ink In is performed along the scanning direction X of the head unit 1 in a predetermined width immediately after the application of the treatment liquid Pr. Thereafter, when the fabric T1 moves in the transport direction Y and the droplet ejection means 20 moves once in the scanning direction X on the return path, the treatment liquid Pr is applied immediately after each ink In is applied at a predetermined width along the scanning direction X of the head unit 1. In a multi-pass coating method as shown in FIG. 2, the operation of applying the ink In and the treatment liquid Pr to the fabric T1 by moving the droplet ejection means 20 once in the scanning direction X is counted as one printing pass, and multiple printing passes are performed on the same area to finally form a desired image on the fabric T1.

[0036] In the inkjet printing method of the present invention, for example, an inkjet coating device shown in FIG. 2 is used to apply the treatment liquid Pr and the ink In to the surface of the fabric T1 by the droplet ejection means 20 as described above, and then the treatment liquid Pr and the ink In are united to form an image.

[0037] The method of ejecting the treatment liquid Pr and each ink In in the head unit 1 is not particularly limited, and may be either an on-demand type or a continuous type head. Examples of on-demand type heads include electro-mechanical conversion types including single cavity type, double cavity type, bender type, piston type, share mode type, and shared wall type, as well as electro-thermal conversion types including thermal inkjet type and bubble jet type ("Bubble Jet" is a registered trademark of Canon Inc.).

[0038] Of the above, an on-demand type head is preferred, and a head using a piezoelectric element as the electro-mechanical conversion element used in the electro-mechanical conversion type (also called a "piezo type inkjet head") is preferred.

[0039] <Drying section> The drying section 105 dries the treatment liquid Pr and the ink In applied by the application section 10. The drying means is not particularly limited, and is preferably hot air, a hot plate, or heating with a heat roller. From the viewpoint of sufficiently removing the solvent component in a short time, heat drying is more preferable. The drying temperature is preferably within the range of 100 to 130°C.

[0040] <Fixing section> The textile printing apparatus 100 may have a fixing unit (not shown) on the downstream side in the transport direction of the drying unit 105, as necessary. The fixing unit is a member that fixes the remaining parts (solid contents of the treatment liquid Pr and the ink In) onto the fabric by further heating or the like after the volatile components in the treatment liquid Pr and the ink In have been removed by the drying unit 105. By passing through the drying unit 105 and an optional fixing unit, the ink Pr can develop a desired hue. Examples of heating means in the fixing unit include heating means using a normal pressure steam method, a high pressure steam method, a thermofix method, etc. It is possible for the drying unit 105 to also function as the fixing unit.

[0041] <Fabric Recovery Department> The fabric recovery unit 102 is provided downstream of the drying unit 105, and recovers while winding up the printed fabric T3 from which the treatment liquid Pr and the ink In have been dried in the drying unit 105. Alternatively, in the case where the fabric T1 separated one by one is transported, the fabric recovery unit 102 may be a fabric discharge unit from which the printed fabric T3 is discharged.

[0042] <Control Unit> FIG. 3 is a block diagram showing an internal configuration of the textile printing apparatus shown in FIG. The control unit 106 controls the inkjet coating device, which is the coating unit 10, to change the conditions for controlling the degree of penetration of the ink In into the fabric T1 between the forward and return passes of the scan in the inkjet coating device, i.e., to change the control conditions in a direction that suppresses the penetration of the ink In into the fabric T1 on the return pass compared to the forward pass. The control conditions for suppressing ink penetration include (i) increasing the amount of treatment liquid applied on the return path compared to the forward path, and (ii) shortening the time interval between application of treatment liquid and ink on the return path compared to the forward path.

[0043] (i) Means for increasing the amount of treatment liquid applied on the return path relative to the outward path include, for example, increasing the area on which treatment liquid is applied on the return path relative to the outward path (i.e., increasing the printing rate on the return path), or increasing the amount of droplets of treatment liquid ejected on the return path relative to the outward path, etc. In the present invention, it is preferable to carry out at least one of these, and it is more preferable to carry out both in combination. "Increasing the coating area of ​​the treatment liquid on the return path relative to the forward path" means that the amount of droplets of the treatment liquid ejected is the same on the forward and return paths, but the coating area is increased on the return path relative to the forward path. "Increasing the amount of droplets of processing liquid ejected on the return path compared to the forward path" means that the application area of ​​the processing liquid on the forward and return paths is the same, but the amount of droplets of processing liquid ejected (i.e., the amount ejected per dot) is greater on the return path compared to the forward path.

[0044] Specifically, it is preferable that the amount of treatment liquid applied on the return path is within a range of 1 to 3 times that of the forward path. In other words, with regard to the coating area (printing rate), it is preferable to increase the printing rate on the return pass by about 25 to 100% compared to the forward pass, and with regard to the amount of droplets of the treatment liquid ejected on the return pass, it is preferable to increase the amount of droplets ejected on the return pass by 5 to 30 pl compared to the forward pass.

[0045] (ii) One way to shorten the time interval between application of treatment liquid and ink on the return path relative to the forward path is to make the transport speed of the carriage on the return path faster than the transport speed on the forward path. Specifically, if the carriage transport speed is 500 to 1500 mm / sec and the distance between each head is approximately 100 mm, it is preferable to make the time interval between application of treatment liquid and ink on the return path shorter by approximately 60 to 200 msec than on the forward path.

[0046] The control unit 106 also controls the fabric pay-out unit 101, the conveying unit 103, the drying unit 105, the fabric recovery unit 102, and the like.

[0047] The control unit 106 receives application information input by a user when operating an operation unit (not shown). The control unit 106 also has a CPU 107, a RAM 108, a ROM 109, etc. The CPU 107 reads out various programs, data, etc. corresponding to the processing contents from a storage device such as the ROM 109, executes them, and controls the operation of each part of the printing apparatus 100 according to the executed processing contents. The RAM 108 temporarily stores various programs, data, etc. processed by the CPU 107. The ROM 109 stores various programs, data, etc. read by the CPU 107, etc.

[0048] Specifically, the control unit 106 operates the application unit 10 in accordance with application information input from an operation unit (not shown) to apply the treatment liquid Pr and the ink In to the fabric T. Examples of the application information include information on the shape of the fabric T1, the amount of treatment liquid Pr applied on the outward or return path, and the speed or speed ratio of the carriage 22 on the outward or return path.

[0049] Examples of the information on the aspect of the fabric include the type of fiber that constitutes the fabric, the thickness of the fabric, the fiber density of the fabric, the ratio of chemical fibers in the fibers that constitute the fabric, the weaving method of the fabric, and the thickness of the fibers that constitute the fabric, and in particular, the type of fiber or fiber density is preferred.

[0050] The types of fibers constituting the fabric include natural fibers (hydrophilic fibers) such as cotton, linen, wool, and silk, and chemical fibers such as rayon, vinylon, nylon, acrylic, polyurethane, polyester, and acetate.

[0051] The thickness of the fabric is generally in the range of 0.1 to 2.0 mm, and is preferably in the range of 0.1 to 1.0 mm in that the effects of the present invention can be significantly exhibited. The fiber density of the fabric is generally 10 to 1000 g / m 2 The range of 50 to 300 g / m is applicable to the present invention and can significantly exhibit the effects of the present invention. 2 The range is preferably:

[0052] The yarns used to make the fabric are not limited to pure yarns, and may be blended yarns or twisted yarns. For fabrics in which the warp and weft yarns are made of the same type of fiber, it is sufficient to specify the fiber type information of either the warp or weft yarns. For fabrics in which the warp and weft yarns are made of different types of fiber, such as interwoven fabrics, it is preferable to specify the fiber type information of each of the warp and weft yarns.

[0053] The unit of fiber thickness may be count, tex, denier, etc. Fiber thicknesses in the range of 10 to 100 denier are generally applicable to the present invention.

[0054] The weaving method of the fabric includes woven fabric, nonwoven fabric, knitted fabric, etc., and the types of weaving method of the woven fabric include plain weave, twill weave, satin weave, etc., depending on the combination of warp and weft threads. The fabric may be a blended woven fabric or blended nonwoven fabric of two or more types of fibers.

[0055] The proportion of chemical fibers in the fibers constituting the fabric is expressed as mass % of the chemical fibers contained relative to the total amount of the fabric.

[0056] The speed ratio of the carriage on the forward path and the return path is the speed ratio of the carriage on the return path to the carriage on the forward path (carriage speed on the return path / carriage speed on the forward path).

[0057] The ROM 109 stores, for example, data on the amount of treatment liquid applied on the forward or return path, data on the speed or speed ratio of the carriage on the forward or return path, and the like, corresponding to application information input from the operation unit. Specifically, for example, table data shown in the following Tables I to V is stored.

[0058] [Table 1]

[0059] [Table 2]

[0060] [Table 3]

[0061] [Table 4]

[0062] [Table 5]

[0063] Table I is a correction table (liquid amount correction table) in which the amount of treatment liquid applied in the return path is increased relative to the outward path, regardless of the fabric aspect information (fiber type and fiber density). Table II is a table showing the application amounts of treatment liquid in the forward and backward passes, which is obtained by further correcting the amounts in Table I based on information on the fabric type (fiber type and fiber density) (liquid amount correction + fabric type correction table). Table III is a table showing the application amounts of treatment liquid in the forward and backward passes, which is corrected in accordance with the fabric aspect information (fiber type and fiber density) in the forward pass in addition to Table II (liquid amount correction + fabric type correction + forward pass liquid amount correction table). In other words, the application amount of treatment liquid is corrected according to the fiber density of the fabric in both the forward and backward passes. Table IV is a correction table (return path carriage speed correction table) in which the carriage speed is increased in the return path relative to the forward path, regardless of the fabric aspect information (fiber type and fiber density). Table V is a table (fabric type correction + reciprocating carriage speed correction table) obtained by further correcting Table IV based on fabric aspect information (fiber type and fiber density).

[0064] The table data shown in Tables I to V are merely examples and are not limited to these. For example, the table may be corrected based on the fabric thickness, chemical fiber ratio, weaving method, fiber thickness, etc., instead of the fabric fiber density, as the fabric aspect information. Furthermore, the table data shown in Tables I to III stipulate the application amount of treatment liquid, but it is also possible to create a table that more specifically stipulates the printing rate (application area) of treatment liquid and the droplet ejection amount of treatment liquid.

[0065] Furthermore, in the above-mentioned printing apparatus, the table data is created in advance from experimental values, and the amount of treatment liquid applied, the carriage speed, etc. are controlled based on this table data. However, without being limited to this, a device for measuring the density of the front or back surface of the fabric after printing may be prepared, and the user may use this device to set the amount of treatment liquid applied, the carriage speed, etc. so that there is no difference in density between the forward and return passes.

[0066] In addition, in the above-mentioned textile printing apparatus, the treatment liquid is applied only at the first printing in the multi-pass method, but the treatment liquid may be applied at each scan. In this case, the penetration degree of the ink into the fabric may be controlled only at the first scan as described above, or the penetration degree may be controlled at each scan.

[0067] The control of the degree of ink penetration into the fabric is changed according to the fabric aspect information, but depending on the type of fabric fiber, no control may be required at all during the round trip in the multi-pass printing. Furthermore, when the ink is a water-based ink and the type of fiber constituting the fabric is cotton, it is preferable to reduce the difference due to the control conditions (e.g., the amount of treatment liquid applied and the carriage transport speed on the return path) on the forward and return paths compared to fibers other than cotton.

[0068] [Inkjet printing method] The inkjet textile printing method of the present invention is an inkjet textile printing method in which a treatment liquid that retains ink on a fabric surface is applied by an inkjet head, the inkjet head that ejects the treatment liquid and the inkjet head that ejects the ink are arranged on the same carriage, an image is formed by a multi-pass method, the ink is applied after the treatment liquid is applied in the outbound pass, the ink is applied after the ink is applied in the return pass, and the conditions for controlling the penetration degree of the ink into the fabric are changed between the outbound pass and the return pass in the multi-pass method. That is, the inkjet textile printing method of the present invention includes a step of applying a treatment liquid and ink, and in the step of applying the treatment liquid and ink, the application conditions are controlled in a direction that suppresses the penetration of the ink into the fabric in the return pass compared to the outbound pass.

[0069] In the step of applying the treatment liquid and ink, the treatment liquid Pr and ink In are applied to the fabric T1 using the ink-jet printing apparatus 100 of the present invention shown in FIG. Here, the application of the treatment liquid Pr and the ink In to the fabric T1 is performed by changing the control conditions in the return path so as to suppress the penetration of the ink In into the fabric T1 compared to the forward path. As described above, based on the application information input from the operation unit, the control unit 106 controls the application unit 10 so that the application amount of the treatment liquid Pr to the fabric T1 and the speed of the carriage 22 become predetermined values, and applies the treatment liquid Pr and the ink In to the fabric T1.

[0070] After the step of applying the treatment liquid Pr and the ink In, the applied treatment liquid Pr and ink In are dried by a drying unit 105 . Thereafter, if necessary, the volatile components in the treatment liquid Pr and the ink In are removed in the drying unit 105 by a fixing unit, and the remainder is then fixed onto the fabric T1 by further heating or the like. Furthermore, the printed fabric T3 that has been dried in the drying section 105 is wound up and collected by the fabric recovery section T3.

[0071] As described above, by changing the conditions for controlling the penetration degree of the ink into the fabric on the forward and return paths, it is possible to reduce the difference in density of the printed areas on the front and back sides of the fabric due to the order in which the treatment liquid and ink are applied. Furthermore, by controlling the amount of treatment liquid applied and the carriage travel speed on the return path according to the fabric information, it is possible to control the appropriate penetration of the ink and treatment liquid into the fabric. In particular, by optimally combining the amount of treatment liquid applied and the carriage travel speed on the return path, even greater effects can be achieved.

[0072] [Processing liquid] The treatment liquid according to the present invention is not particularly limited as long as it contains a component that enhances the fixation of the ink on the surface of the fabric. Examples of such components include compounds having an anionic group (e.g., a carboxyl group, a phosphoric acid group, a phosphonic acid group, a sulfonic acid group, etc.) and compounds having a cationic group (e.g., an amino group, a quaternary ammonium group, etc.).

[0073] Examples of the compound having a cationic group include polyvalent metal salts, resins having a cationic group (such as cationic urethane resins and cationic olefin resins), and cationic surfactants.

[0074] Examples of compounds having an anionic group include resins having an anionic group (for example, plant skins such as pectinic acid, cellulose derivatives such as carboxymethyl cellulose, modified starches such as carboxymethyl starch and carboxyethyl starch, acrylic polymers having acrylic acid as a copolymerization component such as acrylic acid-acrylic acid ester copolymers and styrene-acrylic acid copolymers), and anionic surfactants.

[0075] The treatment agent may further contain, as necessary, a pH adjuster, a preservative, etc. As the preservative, the same preservatives as those exemplified below for the ink can be used.

[0076] [ink] The ink according to the present invention contains a pigment and water.

[0077] <Pigments> The pigment is not particularly limited, but may be, for example, an organic or inorganic pigment having the following numbers as described in the Color Index:

[0078] Examples of red or magenta pigments include Pigment Red 3, 5, 19, 22, 31, 38, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13, 16, 20, 36.

[0079] Examples of blue or cyan pigments include Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17-1, 22, 27, 28, 29, 36, 60.

[0080] Examples of green pigments include Pigment Green 7, 26, 36, and 50. Examples of yellow pigments include Pigment Yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, and 193. Examples of black pigments include Pigment Black 7, 28, and 26.

[0081] Commercially available examples of pigments include: Chromofine Yellow 2080, 5900, 5930, AF-1300, 2700L, Chromofine Orange 3700L, 6730, Chromofine Scarlet 6750, Chromofine Magenta 6880, 6886, 6891N, 6790, 6887, Chromofine Violet RE, Chromofine Red 6820, 6830, Chromofine Blue HS-3, 5187, 5108, 5197, 5085N, SR-5020, 5026, 5050, 4920, 4927, 4937, 4824, 4933GN-EP, 4940, 4973, 5205, 5208, 5214, 5221, 5000P , Chrome Fine Green 2GN, 2GO, 2G-550D, 5310, 5370, 6830, Chrome Fine Black A-1103, Seika Fast Yellow 10GH, A-3, 2035, 2054, 2200, 2270, 2300, 2400(B), 2500, 2600, ZAY-260, 2700(B), 2770 , Seika Fast Red 8040, C405(F), CA120, LR-116, 1531B, 8060R, 1547, ZAW-262, 1537B, GY, 4R-4016, 3820, 3891, ZA-215, Seika Fast Carmine 6B1476T-7, 1483LT, 3840, 3870, Seika Fast Bordeaux 10B-430, Seika Light Rose R40, Seika Light Violet B800, 7805, Seika Fast Maroon 460N, Seika Fast Orange 900, 2900, Seika Light Blue C718, A612, Cyanine Blue 4933M, 4933GN-EP, 4940, 4973 (Dainichi Seika Chemicals); KET Yellow 401, 402, 403, 404, 405, 406, 416, 424, KET Orange 501, KET Red 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 336, 337, 338, 346, KET Blue 101, 102, 103, 104, 105, 106, 111, 118, 124, KET Green 201 (manufactured by Dainippon Ink & Chemicals);Colortex Yellow 301, 314, 315, 316, P-624, 314, U10GN, U3GN, UNN, UA-414, U263, Finecol Yellow T-13, T-05, Pigment Yellow1705, Colortex Orange 202, Colortex Red101, 103, 115, 116, D3B, P-625, 102, H-1024, 105C, UFN, UCN, UBN, U3BN, URN, UGN, UG276, U456, U457, 105C, USN, Colortex Maroon601, Colortex BrownB610N, Colortex Violet600, Pigment Red 122, Colortex Blue516, 517, 518, 519, A818, P-908, 510, Colortex Green 402, 403, Colortex Black 702, U905 (Sanyo Pigment); Lionol Yellow 1405G, Lionol Blue FG7330, FG7350, FG7400G, FG7405G, ES, ESP-S (Toyo Ink Co., Ltd.); Toner Magenta E02, Permanent Rubin F6B, Toner Yellow HG, Permanent Yellow GG-02, Hostapearm Blue B2G (Hoechst Industry); Novoperm P-HG, Hostaperm Pink E, Hostaperm Blue B2G (manufactured by Clariant); Carbon black #2600, #2400, #2350, #2200, #1000, #990, #980, #970, #960, #950, #850, MCF88, #750, #650, MA600, MA7, MA8, MA11, MA100, MA100R, MA77, #52, #50, #47, #45, #45L, #40, #33, #32, #30, #25, #20, #10, #5, #44, CF9 (manufactured by Mitsubishi Chemical).

[0082] (self-dispersing pigment) The pigment may be a self-dispersing pigment. A self-dispersing pigment is a pigment particle whose surface is modified with a group having a hydrophilic group, and has pigment particles and hydrophilic groups bonded to the surface of the pigment particles.

[0083] Examples of hydrophilic groups include carboxyl groups, sulfonic acid groups, and phosphorus-containing groups. Examples of phosphorus-containing groups include phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, phosphite groups, and phosphate groups.

[0084] Commercially available examples of self-dispersing pigments include Cabot's Cab-0-Jet® 200K, 250C, 260M, and 270V (sulfonic acid group-containing self-dispersing pigments), Cab-0-Jet® 300K (carboxylic acid group-containing self-dispersing pigments), and Cab-0-Jet® 400K, 450C, 465M, 470V, and 480V (phosphate group-containing self-dispersing pigments).

[0085] The pigment content is not particularly limited, but from the viewpoint of easily adjusting the viscosity of the ink within the above range and enabling the formation of a high-density image, it is preferably within the range of 1.5 to 15% by mass of the ink. If the pigment content is 1.5% by mass or more, a high-density image is easily formed, and if it is 15% by mass or less, the ink viscosity does not become too high, so that ejection stability is not easily impaired. From the same viewpoint, it is more preferable that the pigment content is within the range of 5 to 15% by mass of the ink.

[0086] <Other ingredients> The ink according to the present invention may further contain other components as necessary, such as a solvent other than water, a polymer dispersant, a binder resin, a preservative, and a pH adjuster.

[0087] (solvent) The solvent is not particularly limited, but is preferably a water-soluble organic solvent. The water-soluble organic solvent is not particularly limited as long as it is compatible with water, but from the viewpoint of making it easier for the ink to penetrate into the interior of the fabric and from the viewpoint of making it difficult to impair the ejection stability in the inkjet method, it is preferable that the ink does not easily thicken due to drying. Therefore, it is preferable that the ink contains a high-boiling point solvent with a boiling point of 200°C or more.

[0088] The high-boiling solvent having a boiling point of 200° C. or higher may be any water-soluble organic solvent having a boiling point of 200° C. or higher, and is preferably a polyol or a polyalkylene oxide.

[0089] Examples of polyols having a boiling point of 200°C or higher include dihydric alcohols such as 1,3-butanediol (boiling point 208°C), 1,6-hexanediol (boiling point 223°C), and polypropylene glycol; and trihydric or higher alcohols such as glycerin (boiling point 290°C) and trimethylolpropane (boiling point 295°C).

[0090] Examples of polyalkylene oxides having a boiling point of 200° C. or higher include ethers of dihydric alcohols such as diethylene glycol monoethyl ether (boiling point 202° C.), triethylene glycol monomethyl ether (boiling point 245° C.), tetraethylene glycol monomethyl ether (boiling point 305° C.), tripropylene glycol monoethyl ether (boiling point 256° C.) and polypropylene glycol, and ethers of trihydric or higher alcohols such as glycerin (boiling point 290° C.) and hexanetriol.

[0091] The solvent may further contain a solvent other than the high boiling point solvent. As the other solvent, the same solvents as those exemplified as the specific examples of the solvent contained in the pretreatment liquid can be used.

[0092] (Polymer dispersant) When the pigment is not a self-dispersing pigment, from the viewpoint of facilitating dispersion of the pigment, it is preferable that the ink further contains a polymer dispersant.

[0093] The type of polymer dispersant is not particularly limited, and may be any of a cationic dispersant, an anionic dispersant, and a nonionic dispersant.

[0094] Examples of the cationic group contained in the cationic dispersant include a secondary amino group (imino group), a tertiary amino group, or a quaternary ammonium group.

[0095] Such a cationic dispersant may be any that can form a pigment dispersion, and is not particularly limited. Examples of such a cationic dispersant include acrylic (co)polymers having a cationic group (a tertiary amino group or a quaternary ammonium group).

[0096] The anionic dispersant is a polymeric dispersant having a hydrophilic group selected from the group consisting of a carboxylic acid group, a phosphorus-containing group, and a sulfonic acid group.

[0097] Examples of polymeric dispersants having a carboxylic acid group include polycarboxylic acids or salts thereof. Examples of polycarboxylic acids include (co)polymers of monomers selected from acrylic acid or its derivatives, maleic acid or its derivatives, itaconic acid or its derivatives, and fumaric acid or its derivatives, and salts thereof.

[0098] The polymeric dispersant having a phosphorus-containing group is a polymeric dispersant having a phosphoric acid group or a phosphonic acid group. Examples of the polymeric dispersant having a phosphoric acid group or a phosphonic acid group include alkyl phosphoric acid esters or salts thereof.

[0099] Examples of polymeric dispersants having sulfonic acid groups include formalin condensates of aromatic sulfonic acids and formalin condensates of lignin sulfonic acids, and preferably formalin condensates of aromatic sulfonic acids. Examples of formalin condensates of aromatic sulfonic acids include sodium condensed naphthalene sulfonate.

[0100] Examples of non-ionic dispersants include polyoxyalkylenes, polyoxyalkylene alkyl ethers, and the like.

[0101] The content of the polymer dispersant is preferably 10 to 50% by mass relative to the pigment. When the content of the polymer dispersant is 10% by mass or more, the dispersibility of the pigment is easily increased sufficiently, and when the content is 50% by mass or less, an excessive increase in viscosity is easily suppressed. From the same viewpoint, the content of the polymer dispersant is preferably 20 to 40% by mass relative to the pigment.

[0102] (binder resin) The binder resin can be a water-soluble resin or resin particles (water-dispersible resin).

[0103] The weight average molecular weight of the binder resin may be 10,000 or more. The weight average molecular weight can be measured by a GPC method in terms of polystyrene.

[0104] However, from the viewpoint of preventing the texture of the fabric from being damaged, it is preferable that the content ratio of the polymer dispersant and the binder resin is low. On the other hand, if the content ratio is low, the content ratio of the pigment is high, and the unevenness of the surface of the color material layer is likely to become large. In such a case, the present invention is particularly effective.

[0105] Specifically, the ratio of the total content of the polymer dispersant and the binder resin to the content of the pigment is preferably 1.5 or less, and more preferably 1.2 or less, in mass ratio.

[0106] (Preservatives, pH adjusters) As the preservatives and pH adjusters, the same ones as those given as specific examples of the preservatives and pH adjusters optionally contained in the treatment agent can be used.

[0107] <Ink properties> The viscosity of the ink at 25°C is not particularly limited as long as it provides good ejection properties using an inkjet method, but is preferably 3 to 20 mPa s, and more preferably 4 to 12 mPa s. The viscosity of the ink can be measured at 25°C using an E-type viscometer.

[0108] <Ink Preparation> The ink can be produced by any method, for example, by mixing the above-mentioned pigment, water, any dispersant, and the like. EXAMPLES

[0109] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following examples, unless otherwise specified, the operations were performed at room temperature (25°C). Furthermore, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively.

[0110] [Preparation of processing solution] A compound having a cationic group, a solvent and other components were mixed to obtain the composition shown below, thereby obtaining a treatment liquid A. Compound having a cationic group: MZ477 (urethane resin, manufactured by Takamatsu Oil Co., Ltd.) 25 parts by mass Solvent: 10 parts by weight of glycerin Solvent: 20 parts by weight of propylene glycol Preservative: Proxel GXL(S) 0.05 parts by weight Surfactant: Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) 0.1 part by mass Ion-exchanged water 44.85 parts by weight

[0111] [Ink preparation] The pigment, pigment dispersant, solvent and other components were mixed to obtain the composition shown below, thereby obtaining ink B. Pigment: Pigment Red 122 3 parts by weight Pigment dispersant: styrene-acrylic copolymer 0.9 parts by weight Solvent: 10 parts by weight of glycerin Solvent: 20 parts by weight of propylene glycol Preservative: Proxel GXL(S) 0.05 parts by weight Surfactant: Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) 0.1 part by mass Ion-exchanged water 69.95 parts by weight

[0112] [Printing method] The following fabrics were prepared: -T / C broadcloth (65% polyester / 35% cotton) Cotton broadcloth 40 (100% cotton by weight) Rayon (100% cotton by weight) -Chinese de chine (100% polyester by weight) Pongee (100% polyester by weight)

[0113] Next, the treatment liquid A and ink B prepared above were applied to the surface of each of the fabrics shown in Table VI below using "Control method 1" and "Control method 2" described in Table I. Here, "control method 1" is a method for controlling the application amount of the treatment liquid, and controls the application amount of the treatment liquid in accordance with the table data shown in Tables I to III above. "Control method 2" is a method for controlling the time interval between application of treatment liquid and ink on the forward and backward passes, and controls the carriage speed on the forward and backward passes in accordance with the table data shown in Tables IV and V. As described above, the treatment liquid and ink were applied to the fabric, and then the fabric was dried by heating at 150° C. for 3 minutes to obtain a printed fabric.

[0114] [Image formation] The printing method of the inkjet head in the printing device was the scan method, and a Konica Minolta Pro120 was used. Images were formed using a dedicated treatment liquid head filled with treatment liquid A and a head filled with ink B. The image was created in two passes (two scans in return), so the color difference between the part printed in the forward / return pass order and the part printed in the return pass / forward pass was evaluated. The treatment liquid was applied only in the first pass to carry out the experiment. (The density difference between the part applied in the order of treatment liquid, ink, ink and the part applied in the order of ink, treatment liquid, ink was evaluated as follows.) The formed image was a solid, monochromatic image with 100% coverage.

[0115] [evaluation] For each of the printed fabrics obtained above, the back surface density difference was evaluated by the following method. <Back side density difference> Evaluation device: Spectrophotometer (CM25cG: manufactured by Konica Minolta) Density measurement locations: Areas where treatment liquid, ink, and ink were applied in that order, and areas where ink, treatment liquid, and ink were applied in that order. In the printed fabric obtained above, the density was measured at 10 points in each of the two parts on the back side of the printed part, and the average value was calculated. The average density difference (ΔE) was calculated from the average density values ​​in the two parts, and evaluated according to the following criteria. 01, 02, and 03 were deemed practically preferable. (standard) ×: ΔE is 2 or more ○1: ΔE is 1 or more and less than 2 ○2: ΔE is 0.5 or more and less than 1 ○3: ΔE is less than 0.5

[0116] [Table 6]

[0117] As shown by the above results, it has been found that in the multi-pass method, by changing the control conditions in a direction that suppresses the penetration of ink into the fabric on the return path compared to the forward path (specifically, by increasing the amount of treatment liquid applied on the return path compared to the forward path, or by shortening the time interval between application of treatment liquid and ink on the return path compared to the forward path), it is possible to reduce the density difference between the printed areas on the front and back sides of the fabric. In particular, by further correcting the control conditions according to the type and fiber density of the fibers constituting the fabric, it is possible to further reduce the density difference between the printed areas on the front and back sides of the fabric.

[0118] In the above evaluation, the back surface density difference was evaluated, but the front surface density difference also showed the same tendency as the back surface density difference (as the front surface density becomes thinner, the back surface density becomes thicker, but the density difference showed the same tendency). However, since the back surface density difference is more sensitive, the density difference on the back surface was evaluated. [Explanation of symbols]

[0119] 1 Head Unit 1Pr Processing liquid head 1Y Yellow ink head 1M Magenta ink head 1C Cyan ink head 1K black ink head 10 Application section 20 Droplet discharge means 22 Carriage 30 Scanning unit 100 Inkjet printing device 101 Fabric payout section 102 Fabric Recovery Department 103 Conveyor 105 Drying section 106 Control section T1 fabric T3 printed fabric

Claims

1. An inkjet textile printing method in which a treatment liquid for fixing ink on a fabric surface is applied by an inkjet head, comprising: the inkjet head that ejects the treatment liquid and the inkjet head that ejects the ink are disposed on the same carriage; An image is formed using a multi-pass method. In the forward path, the treatment liquid is applied, and then the ink is applied. In the return path, the ink is applied, and then the treatment liquid is applied. a control condition is changed in the return path in a direction to suppress the penetration of the ink into the fabric, compared to the forward path; The ink-jet printing method, wherein the control condition is to shorten a time interval between application of the treatment liquid and the ink on the return pass relative to that on the forward pass.

2. 2. The ink-jet printing method according to claim 1, wherein the control conditions can be changed according to the type of fiber constituting the fabric or the fiber density of the fabric.

3. When the ink is a water-based ink and the type of fiber constituting the fabric is cotton, The ink-jet textile printing method according to claim 1 , wherein a difference between the control conditions in the forward pass and the return pass is made small for the fibers other than cotton.

4. An inkjet textile printing apparatus that applies a treatment liquid for fixing ink on a fabric surface using an inkjet head, the inkjet head that ejects the treatment liquid and the inkjet head that ejects the ink are disposed on the same carriage; An image is formed using a multi-pass method. In the forward path, the treatment liquid is applied, and then the ink is applied. In the return path, the ink is applied, and then the treatment liquid is applied. changing a control condition in the return path of the scan in a direction to suppress the penetration of the ink into the fabric, compared to the forward path of the scan; The ink-jet printing apparatus, wherein the control condition comprises shortening a time interval between application of the treatment liquid and the ink on the return pass relative to that on the forward pass.

Images