Image forming method, image forming apparatus, and image forming system

Abstract

[Problem] The present application provides an image forming method, an image forming apparatus, and an image forming system, which have improved dyeing concentration and reduced dyeing unevenness.[Solution] The present application provides an image forming method for forming an image on a cloth by sublimation coloring material, wherein the image forming method sequentially includes a step of applying a pre-treatment liquid to the cloth, the pre-treatment liquid containing an organic compound, a step of drying the cloth, and a step of applying the sublimation coloring material to the cloth, wherein in the step of drying the cloth, a heat source does not contact the cloth.

Description

Technical Field

[0001] This invention relates to an image forming method, an image forming apparatus, and an image forming system. More specifically, it relates to an image forming method, an image forming apparatus, and an image forming system that improves dyeing density and reduces dyeing unevenness. Background Technology

[0002] As a method for forming images on fabrics, the use of sublimation dyes is known. The resulting products have good dyeability (dye concentration and color fastness) and reduce environmental impact, and therefore have been widely used in recent years.

[0003] Sublimation dyes are disperse dyes that are insoluble in water themselves, but are dispersed in water by mixing with a dispersant. With disperse dyes, dye molecules diffuse from the gaps between the amorphous parts of the fiber into the fiber interior, where they bind to the fiber molecules through intermolecular forces and hydrogen bonds, thus achieving dyeing.

[0004] For example, in polyester fibers, the gaps between the amorphous parts are small at room temperature, making it difficult for dye molecules to enter. Therefore, by heating above the glass transition temperature, the micro-Brownian motion becomes active, the gaps between the polymer chains open, and the dye molecules can easily enter. Then, at room temperature, the gaps between the polymer chains close, and the dye molecules are trapped inside the fiber, thus enabling dyeing.

[0005] Therefore, the fabrics commonly used are limited to chemical fibers such as polyester fibers that can be dyed with sublimation dyes. Since dyeing with sublimation dyes can reduce the burden on the environment, it is expected to be applied to natural fibers, regenerated cellulose fibers, etc., which are usually difficult to dye with sublimation dyes.

[0006] However, since there are no gaps for dye molecules to enter in natural fibers and regenerated cellulose fibers, it is necessary to create gaps for dye molecules to enter in advance and to impart sublimation colorants.

[0007] As a method for creating gaps for dye molecules to enter, it is known to use a pretreatment solution containing a swelling agent to swell the fibers. Furthermore, in order to increase the dyeing concentration and reduce dyeing unevenness, it is preferable to apply the pretreatment solution evenly and in appropriate amounts to the fabric.

[0008] Methods for uniformly and appropriately applying pretreatment solution include immersing the fabric in the pretreatment solution and applying it to the fabric using inkjet printing. Furthermore, it is known that drying the fabric after applying the pretreatment solution can prevent the pretreatment solution from being carried over into subsequent processes (e.g., the application of sublimation dyes), thereby improving productivity. However, the inventors have conducted repeated research and found that, according to drying methods, it is difficult to eliminate uneven concentration of the pretreatment solution with high precision, resulting in uneven dyeing. Moreover, in the prior art, the optimal drying method from the viewpoint of increasing dyeing concentration and reducing uneven dyeing has not been sufficiently studied.

[0009] Patent document 1 discloses the following technology: After swelling a fabric substrate that is not dyed by sublimation dyes by using a swelling agent, dyeing is performed by sublimation transfer printing, followed by coating with synthetic resin liquid and heating and drying, thereby sealing and fixing the dye particles inside the fabric substrate.

[0010] In this embodiment demonstrating the technology, a kapok fabric (fabric substrate) was impregnated in a 30% aqueous solution of polypropylene glycol (swelling agent), the kapok fabric was squeezed at 100% extrusion rate, and then dried at 100°C for 5 minutes. However, details of the drying method are not described.

[0011] Patent document 2 discloses a technology involving a transfer printing and dyeing method, which includes a pretreatment step of applying a swelling agent and a water-repellent agent to a fiber product containing plant fibers.

[0012] Here, in the pretreatment process, it is preferred to remove moisture by drying the swelling agent and water-repellent agent, and the drying temperature and time are described in detail. However, details of the drying method are not described.

[0013] Existing technical documents

[0014] Patent documents

[0015] Patent Document 1: Japanese Patent Application Publication No. 07-216763

[0016] Patent Document 2: Japanese Patent Application Publication No. 2021-042514 Summary of the Invention

[0017] The technical problem that the invention aims to solve

[0018] The present invention was made in view of the aforementioned problems and conditions, and the technical problem it solves is to provide an image forming method, an image forming apparatus, and an image forming system that improves staining concentration and reduces staining unevenness.

[0019] Technical means to solve technical problems

[0020] In order to solve the aforementioned technical problem, the inventors conducted research on the causes of the problem and found that in the image forming method of forming an image on fabric by sublimation dye, the method sequentially includes a step of applying a pretreatment liquid to the fabric, a step of drying the fabric, and a step of applying the sublimation dye to the fabric. The pretreatment liquid contains organic compounds. In the drying step, the heat source does not come into contact with the fabric, thereby increasing the dyeing concentration and reducing uneven dyeing, thus completing the present invention.

[0021] That is, the technical problem involved in this invention is solved by the following means.

[0022] 1. An image forming method, which is an image forming method for forming an image on fabric by sublimation pigment, wherein the image forming method comprises:

[0023] The process of applying a pretreatment solution to the fabric,

[0024] The process of drying the fabric, and

[0025] The process of applying the sublimation dye to the fabric.

[0026] The pretreatment solution contains organic compounds.

[0027] During the drying process, the heat source does not come into contact with the fabric.

[0028] 2. The image forming method according to claim 1, wherein the step of applying the sublimation pigment includes a step of transferring a transfer image formed by applying ink containing the sublimation pigment to a transfer medium onto the fabric.

[0029] 3. The image forming method according to claim 1 or 2, wherein, in the drying step, warm air is circulated to dry the fabric.

[0030] 4. The image forming method according to claim 2 or 3, wherein, in the transfer printing step, a heated roller is used to transfer the transfer image formed on the transfer medium onto the fabric.

[0031] 5. The image forming method according to claim 1 or 2, wherein the fabric comprises natural fibers.

[0032] 6. The image forming method according to claim 1 or 2, wherein the fabric contains cellulose.

[0033] 7. The image forming method according to claim 1 or 2, wherein the content of the organic compound is in the range of 35% to 100% by mass relative to the total mass of the pretreatment liquid.

[0034] 8. The image forming method according to claim 7, wherein the content of the organic compound is in the range of 50 to 100% by mass relative to the total mass of the pretreatment liquid.

[0035] 9. The image forming method according to claim 1 or 2, wherein the organic compound comprises an organic compound having an inorganic to organic ratio (I / O value) in the range of 1.00 to 3.00.

[0036] 10. The image forming method according to claim 9, wherein the organic compound comprises dimethyl sulfoxide.

[0037] 11. The image forming method according to claim 1 or 2, wherein the pretreatment liquid further contains a colorant capturing compound.

[0038] 12. An image forming apparatus for forming an image on a fabric by sublimation of a pigment, wherein the image forming apparatus comprises:

[0039] Mechanism for applying pretreatment liquid to the fabric

[0040] The mechanism for drying the fabric, and

[0041] A mechanism for applying the sublimation dye to the fabric.

[0042] In the drying mechanism, the heat source does not come into contact with the fabric.

[0043] 13. The image forming apparatus according to claim 12, wherein the mechanism for applying the sublimation pigment includes a mechanism for transferring a transfer image formed by applying ink containing the sublimation pigment to a transfer medium to the fabric.

[0044] 14. The image forming apparatus according to claim 12 or 13, wherein, in the drying mechanism, warm air is circulated to dry the fabric.

[0045] 15. The image forming method according to claim 2, wherein the pretreatment liquid contains an organic solvent comprising nitrogen or sulfur as a solvent.

[0046] Relative to the overall mass of the fabric, the amount of organic solvent applied immediately after the pretreatment process is completed is in the range of 10-150% by mass, and

[0047] In the transfer printing process, the remaining amount of the organic solvent before transferring the ink containing the sublimation pigment to the fabric is in the range of 3 to 40% by mass relative to the total mass of the fabric.

[0048] 16. The image forming method according to claim 15, wherein the temperature in the step of drying the fabric is below the boiling point of the organic solvent.

[0049] 17. The image forming method according to claim 15 or 16, wherein the temperature at which the fabric is dried is lower than the heating temperature during transfer.

[0050] 18. The image forming method according to claim 17, wherein the pretreatment liquid contains an aromatic heterocyclic compound.

[0051] 19. The image forming method according to claim 17, wherein the pretreatment liquid is applied by inkjet printing.

[0052] 20. An image forming system for dyeing fabric containing natural fibers by sublimation transfer, wherein the image forming system comprises:

[0053] Mechanism for applying pretreatment liquid to the fabric

[0054] Mechanism for drying the fabric

[0055] The mechanism for applying sublimation ink to the transfer medium, and

[0056] A mechanism for transferring the sublimation ink from the transfer medium to the fabric.

[0057] In the mechanism for drying the fabric, the heat source does not come into contact with the fabric.

[0058] The pretreatment liquid contains an organic solvent containing nitrogen or sulfur as a solvent. Immediately after the pretreatment liquid is applied, the amount of the organic solvent applied is in the range of 10-150% by mass relative to the total mass of the fabric.

[0059] In the transfer printing mechanism, the remaining amount of the organic solvent before transferring the sublimation ink to the fabric is in the range of 3 to 40% by mass relative to the total mass of the fabric.

[0060] Invention Effects

[0061] The present invention provides an image forming method, an image forming apparatus, and an image forming system that improve staining concentration and reduce staining unevenness.

[0062] The mechanism by which the effects of this invention are manifested or acted is not yet clear, but the following speculations are made.

[0063] By using a pretreatment solution containing an organic solvent with swelling and dissolving properties, images can be formed on natural fibers, regenerated cellulose fibers, and other materials that are difficult to form images with sublimation pigments.

[0064] Furthermore, when using a pretreatment solution containing an organic solvent with swelling and dissolving functions to form an image by sublimation of the pigment, in order to increase the dyeing concentration and reduce uneven dyeing, it is preferable to apply the pretreatment solution evenly and in appropriate amounts to the fabric after application and drying.

[0065] However, the inventors conducted repeated research and found that the uneven concentration of the pretreatment solution caused by the fabric drying method led to a decrease in dyeing concentration and uneven dyeing.

[0066] Methods for drying fabrics can be broadly categorized into contact drying, which involves bringing a heat source into contact with the fabric, and non-contact drying, which involves bringing a heat source into contact with the fabric.

[0067] In contact drying processes, heat is easily transferred to areas of the fabric closer to the heat source, making drying easier. However, heat is difficult to transfer to areas farther from the heat source, hindering drying. Furthermore, the drying process is susceptible to uneven temperature distribution within the heat source.

[0068] For example, when drying the fabric by contacting the surface of the fabric with a heating plate, uneven concentration of the pretreatment solution is likely to occur in the thickness direction of the fabric. Furthermore, due to the uneven temperature of the heating plate itself, the heated fabric is also prone to uneven temperature, which in turn leads to uneven concentration of the pretreatment solution.

[0069] On the other hand, in non-contact drying, the distance from the heat source is overwhelmingly greater than in contact drying, allowing for uniform heating of the fabric throughout, thus facilitating even drying. Furthermore, it is less susceptible to temperature unevenness within the heat source.

[0070] Moreover, in the non-contact method, by appropriately adjusting the drying temperature, time and other conditions, the uneven concentration of the pretreatment solution can be eliminated with high precision, that is, the pretreatment solution can be uniformly and appropriately applied. Therefore, in the formation of the image, it is believed that the staining concentration can be increased and the staining unevenness can be reduced.

[0071] Furthermore, the image forming method of the present invention is an image forming method of dyeing by sublimation transfer, wherein a specific amount of pretreatment liquid containing an organic solvent containing nitrogen or sulfur is applied to a fabric containing natural fibers, the fabric is swollen and then dried to reduce the content of the organic solvent in the pretreatment liquid, and then sublimation dye is transferred to form an image.

[0072] In patent documents 1 and 2, a swelling agent (polyol) is pre-infiltrated into the fabric to expand the gaps between fibers by swelling the fabric, making it easier for the sublimated dye to enter the fiber interior.

[0073] In contrast, in the image forming method of the present invention, the pretreatment liquid contains an organic solvent containing nitrogen or sulfur as a solvent for sublimation dyes, and thus also functions as a swelling agent. Therefore, compared with the transfer images of conventional techniques using swelling agents (polyols), it is easier to capture the sublimation dye into the fibers of the fabric, resulting in a higher dyeing concentration.

[0074] Furthermore, by using a swelling agent to swell the fabric, expanding the gaps between fibers and allowing sublimation dyes to easily penetrate the fibers, the fabric is then dried, reducing the content of the organic solvent in the pretreatment solution. This controls the amount of the swelling agent to a certain level, thus suppressing yellowing of the white background of the transferred image and discoloration of the sublimation ink under high humidity conditions caused by excessive amount of swelling agent.

[0075] That is, it is an image formation method that has high dyeability of fabrics containing natural fibers and can suppress yellowing during heating and discoloration under high humidity conditions. Attached Figure Description

[0076] Figure 1 This is a schematic diagram of the image forming apparatus (sublimation transfer method, continuous type) of the present invention.

[0077] Figure 2 This is a schematic diagram of the image forming apparatus (direct method) of the present invention.

[0078] Figure 3 This is a schematic diagram illustrating an example of the structure of a drying section that uses circulating warm air to dry fabrics.

[0079] Figure 4 This is a block diagram representing a structure that controls the conditions applied to the pretreatment liquid based on fabric information.

[0080] Figure 5 This is a schematic diagram of the heating roller in the sublimation transfer process.

[0081] Figure 6 This is a schematic diagram illustrating an example of the image recording system of the present invention.

[0082] Figure 7 This is a block diagram showing the internal structure of the pretreatment liquid imparting device. Detailed Implementation

[0083] The image forming method of the present invention is an image forming method for forming an image on a fabric by sublimation pigment, characterized by comprising, in sequence: a step of applying a pretreatment liquid to the fabric, a step of drying the fabric, and a step of applying the sublimation pigment to the fabric, wherein the pretreatment liquid contains an organic compound, and in the drying step, the heat source does not come into contact with the fabric.

[0084] This feature is a technical feature common to or corresponding to the embodiments described below.

[0085] As an embodiment of the present invention, from the viewpoint that the present invention has significant effects, it is preferred that the process of applying the sublimation color material includes the process of transferring a transfer image formed by applying ink containing the sublimation color material to a transfer medium to the fabric.

[0086] As an embodiment of the present invention, from the viewpoint of demonstrating the effects of the present invention, it is preferable to use circulating warm air to dry the fabric in the drying process.

[0087] As an embodiment of the present invention, from the viewpoint of uneven dyeing, it is preferable to use a heated roller to transfer the transfer image formed on the transfer medium to the fabric during the transfer process.

[0088] As an embodiment of the present invention, from the viewpoint of demonstrating the effects of the present invention, the fabric preferably contains natural fibers.

[0089] As an embodiment of the present invention, from the viewpoint of demonstrating the effects of the present invention, the fabric preferably contains cellulose.

[0090] As an embodiment of the present invention, from the viewpoint of dyeing concentration and dyeing unevenness, the content of the organic compound is preferably in the range of 35 to 100% by mass relative to the total mass of the pretreatment solution, and more preferably in the range of 50 to 100% by mass.

[0091] As an embodiment of the present invention, from the viewpoint of staining concentration and staining unevenness, the organic compound preferably comprises an organic compound whose inorganic value to organic value ratio (I / O value) is in the range of 1.00 to 3.00, and the organic compound more preferably comprises dimethyl sulfoxide.

[0092] As an embodiment of the present invention, from the viewpoint of dyeing concentration, the pretreatment solution preferably also contains a colorant capturing compound.

[0093] The image forming apparatus of the present invention is an image forming apparatus that forms an image on a fabric by sublimation pigment, characterized in that it comprises: a mechanism for applying a pretreatment liquid to the fabric; a mechanism for drying the fabric; and a mechanism for applying the sublimation pigment to the fabric, wherein in the drying mechanism, a heat source does not come into contact with the fabric.

[0094] As an embodiment of the present invention, from the viewpoint of demonstrating the effects of the present invention, it is preferable that the mechanism for imparting the sublimation pigment has a mechanism for transferring a transfer image formed by applying ink containing the sublimation pigment to a transfer medium to the fabric.

[0095] As an embodiment of the present invention, from the viewpoint of demonstrating the effects of the present invention, it is preferable to use circulating warm air to dry the fabric in the drying mechanism.

[0096] As an embodiment of the present invention, from the viewpoint of high dyeability of fabrics and ability to suppress yellowing during heating and discoloration under high humidity conditions, it is preferable that the pretreatment liquid contains an organic solvent containing nitrogen or sulfur as a solvent, and that the amount of the organic solvent applied immediately after the pretreatment liquid application process is in the range of 10% to 150% by mass relative to the total mass of the fabric, and that the remaining amount of the organic solvent before transferring the ink containing the sublimation pigment to the fabric in the transfer printing process is in the range of 3% to 40% by mass relative to the total mass of the fabric.

[0097] As an embodiment of the present invention, from the viewpoint that the organic solvent can easily remain in the interior of the fabric in an amount within an optimal range, it is preferable that the temperature in the process of drying the fabric is lower than the boiling point of the organic solvent.

[0098] From the viewpoint of suppressing discoloration caused by heating the white background of the fabric, it is preferable that the temperature at which the fabric is dried is lower than the heating temperature during transfer printing.

[0099] From the viewpoint of easily capturing dyes from sublimated inks within the fibers of fabric and increasing dyeing concentration, the pretreatment solution preferably contains aromatic heterocyclic compounds.

[0100] From the viewpoint that the pretreatment liquid can be applied continuously with the process of applying sublimation ink, it is preferable to apply the pretreatment liquid by inkjet printing.

[0101] The image forming system of the present invention is an image forming system for dyeing fabric containing natural fibers by sublimation transfer. It is characterized by comprising: a mechanism for applying a pretreatment liquid to the fabric; a mechanism for drying the fabric; a mechanism for applying sublimation ink to a transfer medium; and a mechanism for transferring the sublimation ink from the transfer medium to the fabric. In the fabric drying mechanism, the heat source does not contact the fabric. The pretreatment liquid contains an organic solvent containing nitrogen or sulfur as a solvent. Immediately after applying the pretreatment liquid, the amount of the organic solvent applied is in the range of 10% to 150% by mass relative to the total mass of the fabric. Furthermore, in the transfer mechanism, the remaining amount of the organic solvent before transferring the sublimation ink to the fabric is in the range of 3% to 40% by mass relative to the total mass of the fabric.

[0102] The present invention, its constituent elements, and methods and approaches for implementing the present invention will be described in detail below. It should be noted that in this application, the symbol "~" is used to indicate the lower and upper limits, including the numerical values ​​described before and after it.

[0103] 1. Overview of Image Formation Methods

[0104] The image forming method of the present invention is an image forming method for forming an image on a fabric by sublimation pigment, characterized in that it sequentially includes: a step of applying a pretreatment liquid to the fabric, a step of drying the fabric, and a step of applying the sublimation pigment to the fabric, wherein the pretreatment liquid contains an organic compound, and in the drying step, the heat source does not come into contact with the fabric.

[0105] This invention improves the dyeing concentration and reduces dyeing unevenness by applying the pretreatment liquid with high precision, uniformity and appropriate amount. Therefore, the subsequent method of applying sublimation pigment is not particularly limited. It can be a sublimation transfer method, a direct method or other methods.

[0106] Hereinafter, the process of creating images on fabric through sublimation transfer will be referred to as "sublimation transfer".

[0107] "Sublimation transfer printing" refers to a method in which an image (for transfer printing) is formed on a transfer medium using sublimation pigment (hereinafter also called "sublimation dye" or "sublimation dye"), and then the vaporized sublimation pigment is fixed to the fabric by heating and pressurizing the transfer medium and the fabric to form the image.

[0108] In addition, the "direct method" refers to the method of directly applying sublimation pigment to the fabric, and then heating the fabric to fix the vaporized sublimation pigment onto the fabric to form an image.

[0109] The sublimation dye used is a disperse dye, which is insoluble in water (hydrophobic) but dispersed in water by mixing with a dispersant. Disperse dyes have good dyeing properties and are often used for dyeing hydrophobic chemical fibers.

[0110] However, in this invention, by using a combination of pretreatment solutions, it is also possible to apply to fibers with high hydrophilicity (e.g., fibers containing cellulose).

[0111] It should be noted that, as described above, the present invention is applicable to situations where an image is formed by sublimation of pigments after a pretreatment liquid has been applied to the fabric.

[0112] In this invention, "dyeing" refers to using colorant (dye) to fix pigment onto fabric, and "dyeability" refers to the degree or grade of pigment fixation. Furthermore, "color development" refers to using colorant (dye) to make fabric exhibit the desired color, and "color development" refers to the degree or grade of color development relative to the desired color.

[0113] It is believed that by using the image forming method of the present invention, the pretreatment solution is uniformly and appropriately applied to the fabric after application and drying, thus enabling the pigment to be uniformly and appropriately fixed to the fabric, i.e., increasing the dyeing concentration and reducing uneven dyeing. Furthermore, it is believed that the fabric can exhibit a color closer to the desired color, i.e., improved color development.

[0114] Furthermore, compared to other image forming methods, the formation of images based on sublimation pigments produces less waste liquid in each process, thus reducing the environmental impact. As an image forming method that reduces environmental impact, methods for forming images on fabrics using direct inkjet printing are known; however, in the formation of images based on sublimation pigments, the unique hand feel of the fiber can be preserved.

[0115] It should be noted that the term "image" generally refers to an image obtained by visually fixing an event on a medium. In this invention, it includes images, characters, patterns, pictures, etc., that are colored with a single color.

[0116] (1) Cloth

[0117] The fabrics of the present invention are not particularly limited, but from the viewpoint of demonstrating the effects of the present invention, it is preferable to include fibers that, through prior pretreatment, can form images by sublimation transfer or have improved image quality.

[0118] For example, natural fibers such as cotton, linen, wool, and silk, as well as chemical fibers such as vinylon, nylon, acrylic fibers, polyurethane, and acetate fibers can be cited.

[0119] In addition, as part of chemical fibers, examples include regenerated fibers (such as rayon) prepared by dissolving natural fibers containing cellulose, such as wood and cotton, through a chemical reaction and then spinning them again.

[0120] It should be noted that for polyester fibers, images can usually be formed by sublimation pigments even without prior pretreatment. However, for polyester fibers with high hydrophilicity, this invention can be applied when the quality of the obtained image is improved (by increasing the color intensity) through prior pretreatment.

[0121] From the viewpoint of demonstrating the effects of the present invention, the fabric preferably contains natural fibers. The fabric may be composed of only one type of natural fiber, or it may be composed of two or more types of natural fibers. Furthermore, when the fabric contains natural fibers, it may be composed of only natural fibers, or it may be composed of both natural and synthetic fibers. Here, the synthetic fibers may be one type, or two or more types.

[0122] From the viewpoint of demonstrating the effects of the present invention, the fabric preferably contains cellulose. It should be noted that cellulose can be contained as a natural fiber or as the regenerated fiber. The fabric may be composed of only one type of cellulose-containing fiber, or it may be composed of two or more types. Furthermore, when the fabric contains cellulose-containing fibers and other fibers, polyester fibers are preferably the other fibers.

[0123] Fabric can be made from these fibers into any form, such as woven fabric, non-woven fabric, or knitted fabric. In addition, fabric can also be a blend of two or more fibers, either woven or non-woven.

[0124] The proportion of natural fibers and chemical fibers in the fibers that make up a fabric is expressed as: the percentage of natural fibers and the percentage of chemical fibers contained relative to the total mass of the fabric (the total mass of natural fibers and chemical fibers).

[0125] When the fabric contains natural fibers and any chemical fibers, the proportion of natural fibers in the fabric is preferably in the range of 5% to 100% by mass, and the proportion of chemical fibers is preferably in the range of 0% to 95% by mass.

[0126] Furthermore, when the fabric contains cellulose-containing fibers and polyester fibers, it is preferable that the proportion of cellulose-containing fibers is in the range of 35 to 100% by mass and the proportion of polyester fibers is in the range of 0 to 65% by mass relative to the total mass of the fabric.

[0127] 2. Each step of the image forming method

[0128] The image forming method of the present invention is characterized by comprising, in sequence, a step of applying a pretreatment liquid to a fabric, a step of drying the fabric, and a step of applying a sublimation dye to the fabric.

[0129] Hereinafter, the process of applying a pretreatment solution to the fabric will be referred to as the "pretreatment solution application process", the process of drying the fabric will be referred to as the "pretreatment solution drying process", and the process of applying a sublimation dye to the fabric will be referred to as the "sublimation dye application process".

[0130] As mentioned above, there are no particular limitations on the method of applying sublimation pigments; it can be sublimation transfer printing, direct printing, or other methods.

[0131] Figure 1 This is a schematic diagram of the image forming apparatus (sublimation transfer method, continuous type) of the present invention. Hereinafter, a brief description will be given of the case where an image is formed using the image forming apparatus 400 by the image forming method of the present invention.

[0132] For the fabric C fed out from the fabric feeding section 101, a pretreatment liquid is applied in the pretreatment liquid application section 103, and the fabric C1 with the pretreatment liquid is dried in the pretreatment liquid drying section 104 to remove the remaining pretreatment liquid, thus producing fabric C2 with an appropriate amount of pretreatment liquid applied.

[0133] Here, the process performed in the pretreatment liquid dispensing section 103 is equivalent to the pretreatment liquid dispensing process, and the process performed in the pretreatment liquid drying section 104 is equivalent to the pretreatment liquid drying process.

[0134] Furthermore, in the inkjet recording unit 203, the transfer medium P sent from the transfer medium delivery unit 201 is given ink containing sublimation pigment (hereinafter also referred to as "sublimation ink"), and in the ink drying unit 204, the transfer medium P1 given with sublimation ink is dried to obtain a transfer medium P2 with a transfer image formed thereon.

[0135] However, the method of forming the image for transfer is just one example and is not limited to this.

[0136] In the transfer section 301, the fabric C2, to which an appropriate amount of pretreatment liquid has been applied, and the transfer medium P2, on which the transfer image is formed, are heated and pressurized to sublimate and transfer the transfer image onto the fabric. Then, the fabric and the transfer medium are peeled off, and the fabric N on which the image is formed and the heated and pressurized transfer medium P3 are recovered respectively.

[0137] However, the heating and pressurizing method is just one example, and is not limited to it.

[0138] Here, the process performed by the transfer unit 301 is equivalent to the sublimation color material application process.

[0139] also, Figure 2 This is a schematic diagram of the image forming apparatus (direct method) of the present invention. Hereinafter, a brief description will be given of the case where an image is formed using the image forming apparatus 600 by the image forming method of the present invention.

[0140] For the fabric C fed out from the fabric feeding section 101, a pretreatment liquid is applied in the pretreatment liquid application section 103, and the fabric C1 with the pretreatment liquid is dried in the pretreatment liquid drying section 104 to remove the remaining pretreatment liquid, thus producing fabric C2 with an appropriate amount of pretreatment liquid applied.

[0141] Here, the process performed in the pretreatment liquid dispensing section 103 is equivalent to the pretreatment liquid dispensing process, and the process performed in the pretreatment liquid drying section 104 is equivalent to the pretreatment liquid drying process.

[0142] Next, sublimation ink is applied to the fabric C2, which has been given an appropriate amount of pretreatment liquid, in the inkjet recording unit 501, and the fabric with the sublimation ink is heated in the ink heating unit 502. Then, the sublimation ink is fixed on the fabric, and the fabric N with the image is recovered.

[0143] Here, the process performed by the inkjet recording unit 501 and the ink heating unit 502 is equivalent to the sublimation color material application process.

[0144] The following is a detailed description of each step in the image forming method of the present invention.

[0145] (1) Pretreatment liquid application process

[0146] The pretreatment liquid application process is a process of applying a pretreatment liquid to fabric. Furthermore, it is characterized in that the pretreatment liquid contains an organic compound.

[0147] The term "organic compound" here is not particularly limited, but is preferably an organic compound that has swelling properties and solubility for sublimation dyes (details below) (having both swelling and dissolving functions), and is an organic solvent. Hereinafter, the solvent for dissolving sublimation dyes will be referred to as "organic solvent A" as an example.

[0148] (1.1) Pretreatment solution

[0149] The pretreatment solution of the present invention contains organic solvent A.

[0150] The pretreatment solution of the present invention may consist of only organic solvent A, or may further contain color material capturing compounds and other components as needed.

[0151] (1.1.1) Composition of the pretreatment solution

[0152] (1.1.1.1) Organic solvent A

[0153] The pretreatment solution of the present invention contains organic solvent A.

[0154] As mentioned above, organic solvent A has the ability to swell fabrics and to dissolve sublimation dyes.

[0155] In this invention, "swelling" refers to the increase in volume of fibers contained in a fabric by absorbing substances.

[0156] Therefore, "swellability of fabrics" refers to the property of increasing the volume of fibers through absorption.

[0157] It is believed that by applying the pretreatment liquid of the present invention, i.e., organic solvent A, to the fabric, the fibers contained in the fabric swell, and the sublimated dye material can easily enter the fibers through organic solvent A, thereby improving the dyeability.

[0158] Organic solvent A is not particularly limited as long as it is an organic solvent that has swelling properties for fabrics and the ability to dissolve sublimation dyes. The ratio of inorganic value to organic value (I / O value) is preferably in the range of 1.0 to 5.0, more preferably in the range of 1.0 to 3.0, and even more preferably in the range of 1.5 to 2.0.

[0159] When the I / O value is within the specified range, the fibers in the fabric easily swell, and organic solvent A acts as a carrier for the sublimation dye, allowing the sublimation dye to easily penetrate into the fibers. Consequently, the sublimation dye is more easily fixed, increasing the dyeing concentration and reducing uneven dyeing in fabrics with printed images.

[0160] The "I / O value" refers to the ratio of inorganic value (I) to organic value (O) (inorganic value / organic value), also known as the "IOB value" (Inorganic Organic Balance: IOB), which is one of the indicators of the polarity of a compound.

[0161] Regarding I / O values, detailed explanations can be found in organic conceptual diagrams (by Yoshio Koda, published by Sankyo (1984)); KUMAMOTOPHARMACEUTICAL BULLETIN, No. 1, Items 1-16 (1954); and Chemical Fields, Vol. 11, No. 10, Items 719-725 (1957). The I / O value is a value used in the organic conceptual treatment of the polarity of a compound. This method is one of the functional group contribution methods, which sets parameters for each functional group and shows inorganic and organic values ​​for each functional group. It should be noted that the I / O value represents the value at various points on an orthogonal coordinate system named the organic axis and the inorganic axis, roughly dividing the properties of the compound into organic groups exhibiting covalent bonds and inorganic groups exhibiting ionic bonds.

[0162] Here, "inorganic value (I)" refers to the value obtained by numerically representing the influence of various substituents or bonds on the boiling point of an organic compound, using the hydroxyl group as a reference. Specifically, if the distance between the boiling point curve of a straight-chain alcohol and the boiling point curve of a linear paraffin near the 5th carbon atom is approximately 100°C, then the influence of one hydroxyl group is numerically defined as 100. Based on this value, the value obtained by numerically representing the influence of various substituents or bonds on the boiling point is the inorganic value (I) of the substituents in the organic compound. For example, the inorganic value (I) of the -COOH group is 150, and the inorganic value (I) of a double bond is 2. Therefore, the inorganic value (I) of a certain organic compound is the sum of the inorganic values ​​(I) of all substituents or bonds in the compound.

[0163] Furthermore, the "organic property value (O)" refers to a value defined using the methylene group within a molecule as the unit and the influence of the carbon atom representing that methylene group on the boiling point as the benchmark. Specifically, since the average increase in boiling point caused by adding one carbon atom in straight-chain saturated hydrocarbons with 5-10 carbon atoms is 20°C, the organic property value of one carbon atom is set at 20 based on this benchmark. The value of the influence of various substituents or bonds on the boiling point is then numerically converted to the organic property value (O). For example, the organic property value (O) of a nitro group (-NO2) is 70.

[0164] Generally, the closer the I / O value is to 0, the more nonpolar (hydrophobic, organic) the organic compound is. On the other hand, the larger the value, the more polar (hydrophilic, inorganic) the organic compound is.

[0165] Examples of organic solvents A with an I / O value of 1.0 or higher include 2-pyrrolidone (I / O value: 1.15), ethylene glycol monoethyl ether (I / O value: 1.5), dimethyl sulfoxide (I / O value: 1.75), butyric acid (I / O value: 1.875), polyethylene glycol (I / O value: 2.0), isobutyric acid (I / O value: 2.143), 2,3-butanediol (I / O value: 2.5), trimethylolethane (I / O value: 3.0), propylene glycol (I / O value: 3.3), polypropylene glycol (I / O value: 3.3), and ethylene glycol (I / O value: 5.0). From the viewpoint of being able to cause the fabric fibers to swell and to suppress discoloration / fading of fabrics with images, dimethyl sulfoxide, ethylene glycol, and propylene glycol are preferred, with dimethyl sulfoxide being more preferred.

[0166] Furthermore, the boiling point of organic solvent A is preferably in the range of 170 to 250°C. Examples of organic solvent A with a boiling point in the range of 170 to 250°C include propylene glycol (boiling point 188°C), ethylene glycol (boiling point 197°C), dimethyl sulfoxide (boiling point 189°C), and 2,3-butanediol (boiling point 177°C).

[0167] From the viewpoint of staining concentration and uneven staining, the content of the organic solvent A relative to the total mass of the pretreatment solution is preferably in the range of 5 to 100% by mass, more preferably in the range of 35 to 100% by mass, and even more preferably in the range of 50 to 100% by mass.

[0168] (1.1.1.2) Colorant Capturing Compound

[0169] The pretreatment solution of the present invention preferably also contains a colorant capturing compound.

[0170] By incorporating color-capturing compounds, dyeing concentration can be increased. Furthermore, it can suppress discoloration / fading of fabrics with printed images.

[0171] It should be noted that "color change / fading" here refers to color change (change in hue) and fading (color fading) over time.

[0172] By applying the organic solvent A of the present invention to the fabric, the fibers contained in the fabric swell, and the sublimation dye can easily enter the fibers through the organic solvent A. However, in order to increase the dyeing concentration, it is also necessary to fix the sublimation dye in the fibers.

[0173] Since sublimation pigments are hydrophobic, they are easy to fix in hydrophobic polyester fibers. However, it is difficult to fix sublimation pigments in fibers containing cellulose, for example, cellulose fibers that have multiple hydroxyl groups as hydrophilic groups.

[0174] Therefore, by imparting color-capturing compounds to fabrics, sublimation colorants can be easily fixed even in fabrics containing hydrophilic fibers.

[0175] It should be noted that there are no particular limitations on the method of imparting the colorant-capturing compound to the fabric, but it is preferable that the pretreatment solution further contains the colorant-capturing compound.

[0176] In this invention, "color material capturing compound" refers to a compound that has the function of capturing color materials (color material capturing power), specifically, it refers to a compound whose Rf value is less than 1 as determined by the following paper chromatography method.

[0177] Furthermore, regarding the colorant capturing compound, from the viewpoint of colorant capturing power, the Rf value obtained by paper chromatography is preferably 0.7 or less, more preferably 0.5 or less, even more preferably 0.3 or less, and particularly preferably 0.2 or less.

[0178] Paper chromatography

[0179] Step 1: Impregnate cellulose filter paper with a 10% solution of the colorant capturing compound, then dry it to prepare a carrier.

[0180] Step 2: Spot the 0.1% tetrahydrofuran solution of the sublimation pigment onto the carrier, then dry it to prepare the developed sample.

[0181] Step 3: Develop the sample with acetonitrile at 25°C for 3 minutes.

[0182] Step 4: Calculate the Rf value using the following formula.

[0183] (Formula) Rf value = Development distance of sublimation pigment / Development distance of acetonitrile

[0184] The following is a detailed explanation of each step.

[0185] (Step 1)

[0186] A carrier is prepared by impregnating cellulose filter paper of the five types specified in JIS P 3801:1995 with a 10% solution of the colorant capturing compound and then drying it. The solvent used in the 10% solution of the colorant capturing compound is not particularly limited, as long as it can dissolve the colorant capturing compound; organic solvents such as those contained in the pretreatment solution (e.g., A) can be used. The shape of the cellulose filter paper is not particularly limited; for example, it can be a long strip. The size of the cellulose filter paper is not particularly limited, but it needs to be large enough to allow for sufficient unfolding in step 3. Impregnation of the cellulose filter paper with the solution is performed by immersing the cellulose filter paper in the solution for 1 minute. The drying conditions are not particularly limited, as long as the carrier can be thoroughly dried at 25°C and 50% RH until its quality is stable.

[0187] (Step 2)

[0188] A 0.1% tetrahydrofuran solution of sublimation pigment (details below) is spotted onto the carrier and then dried to prepare the developed sample. Spotting the solution can be done using a capillary tube. The volume of solution used for spotting is preferably in the range of 0.5 to 2 μL, more preferably 1 μL. The spotting position is set 1 cm from the bottom of the cellulose filter paper. The drying conditions are not particularly limited, as long as the sample can be thoroughly dried at 25°C and 50% RH until the quality of the developed sample is stable.

[0189] (Step 3)

[0190] At 25°C, develop the sample with acetonitrile for 3 minutes. Specifically, place the sample upright in the developing tank containing acetonitrile, ensuring that the portion spotted in step 2 is not immersed in the acetonitrile. Cover the developing tank and allow it to develop. The development time is 3 minutes after the cellulose filter paper begins to come into contact with the acetonitrile.

[0191] (Step 4)

[0192] The value of Rf is obtained from the following formula.

[0193] (Formula) Rf value = Development distance of sublimation pigment / Development distance of acetonitrile

[0194] "The sublimation material development distance" is set as the distance from the center of the part sampled in step 2 to the position of the most intense color in the developed spot. If it is difficult to determine the position of the most intense color, it is set as the distance from the center of the part sampled in step 2 to the center of the front and back ends of the spot.

[0195] "Expanding distance of acetonitrile" is the distance from the center of the part where the sample was spotted in step 2 to the front end of the expanded acetonitrile.

[0196] To ensure accuracy, the Rf value can also be the average of multiple measurements.

[0197] The color material capturing compound of the present invention is not particularly limited as long as it is a compound with color material capturing ability, specifically, as long as it is a compound with an Rf value of less than 1. It is preferably a compound with an aromatic ring (aromatic compound), and more preferably a compound with an aromatic heterocycle (aromatic heterocyclic compound).

[0198] In this invention, "aromatic heterocycle" refers to an aromatic ring composed of carbon and heteroatoms other than carbon, excluding cases where the element constituting the aromatic ring is only carbon and the heteroatoms constitute substituents that substitute on the aromatic ring.

[0199] From the perspective of colorant capture ability, the heteroatom of the aromatic heterocycle constituting the aromatic heterocyclic compound is preferably an oxygen atom, a nitrogen atom, or a sulfur atom, and more preferably a nitrogen atom.

[0200] Examples of aromatic heterocyclic compounds include pyrazole rings, triazole rings, imidazole rings, triazine rings, pyridine rings, pyrazole rings, acridine rings, indole rings, quinoline rings, pyrrole rings, and thiophene rings. From the viewpoint of colorant capturing power, pyrazole rings, triazole rings, or imidazole rings are preferred.

[0201] Furthermore, the aromatic heterocyclic compound preferably has three or more aromatic rings, more preferably five or more aromatic rings. Additionally, a structure consisting of two aromatic rings bonded together by single bonds is preferred as a part or as a whole. If the aromatic heterocyclic compound has these structures, its aromaticity increases, thus strengthening the π-π interaction with the sublimated pigment. This improves the pigment's capturing power and further suppresses discoloration / fading.

[0202] The solubility of the colorant-capturing compound in a solvent also present in the pretreatment solution at 25°C and 1 atmosphere is preferably 10% by mass or more. The higher the solubility in the solvent, the easier it is for the colorant-capturing compound to enter the interior of the fibers contained in the fabric in a dissolved state, thus improving the colorant-capturing power and further increasing the dyeing concentration.

[0203] Furthermore, from the viewpoint of efficiently capturing sublimated colorants, the colorant capturing compound is preferably of low molecular weight. Here, low molecular weight means, for example, a molecular weight in the range of 200 to 1000.

[0204] Examples of the color material capturing compounds of the present invention are provided. It should be noted that the color material capturing compounds of the present invention are not limited to these examples.

[0205] [Chemical Formula 1]

[0206]

[0207] [Chemical Formula 2]

[0208]

[0209] From the viewpoint of colorant capture capacity, the content of colorant capturing compound is preferably in the range of 1 to 30% by mass relative to the total mass of the pretreatment liquid, and more preferably in the range of 10 to 20% by mass.

[0210] (1.1.1.3) Other components

[0211] The pretreatment solution of the present invention may further contain other components besides those described above, as needed. Examples of other components include water, surfactants, preservatives, pH adjusters, etc.

[0212] Examples of water include ion-exchanged water, distilled water, and pure water. The water content relative to the total mass of the pretreated liquid is preferably in the range of 0 to 95% by mass, and more preferably in the range of 0 to 50% by mass.

[0213] Surfactants can be used without particular limitation. When the ink contains anionic compounds, the ionic nature of the surfactant is preferably anionic or nonionic, and when it is amphoteric, it is preferably betaine-type.

[0214] Specifically, preferred surfactants include fluorinated or polysiloxane surfactants with high static surface tension reduction capabilities, anionic surfactants such as dioctyl sulfosuccinate and sodium dodecyl sulfate with high dynamic surface tension reduction capabilities, and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, ethynyl glycols, PLURONIC-type surfactants (PLURONIC is a registered trademark), and sorbitan derivatives. It is also preferable to use fluorinated or polysiloxane surfactants in combination with surfactants that have high dynamic surface tension reduction capabilities.

[0215] Examples of preservatives include aromatic halogen compounds (e.g., Preventol CMK), methylene dithiocyanate, halogenated nitrogen and sulfur compounds, and 1,2-benzisothiazolin-3-one (e.g., PROXELGXL).

[0216] Examples of pH adjusters include citric acid, sodium citrate, hydrochloric acid, and sodium hydroxide.

[0217] (1.1.2) Physical properties of the pretreatment solution

[0218] The viscosity of the pretreatment solution of the present invention at 25°C can be appropriately adjusted according to the method of applying it to the fabric. For example, when the pretreatment solution is applied by inkjet printing, the viscosity of the pretreatment solution is preferably in the range of 3 to 20 mPa·s. It should be noted that the viscosity of the pretreatment solution can be measured at 25°C using an E-type viscometer.

[0219] (1.2) Method for administering pretreatment solution

[0220] In the pretreatment liquid application process of the present invention, the pretreatment liquid is applied to at least a portion of the surface of the fabric. The application of the pretreatment liquid can be performed on the entire surface of the fabric, or it can be selectively performed on only the area where the image is formed by the sublimation pigment, depending on the resulting image.

[0221] There are no particular limitations on the method for applying the pretreatment solution to the fabric, and known methods can be used. Examples include spraying, padding (pad or impregnation), coating, and inkjet printing. The temperature of the pretreatment solution is not particularly limited, but is preferably in the range of 15–30°C.

[0222] From the viewpoint of imparting a given amount of pretreatment liquid in a short time, the padding method and the coating machine method are preferred. In the padding method, after the fabric is immersed in the pretreatment liquid stored in the bath, the fabric is squeezed by rollers under pressure, thereby adjusting the amount of pretreatment liquid imparted.

[0223] Furthermore, from the viewpoint that the pretreatment liquid application process, the pretreatment liquid drying process, and the transfer process can be performed continuously, inkjet printing is preferred.

[0224] There is no particular limitation on the amount of pretreatment liquid applied to the fabric; it can be adjusted according to the content of solvents in the pretreatment liquid, the amount of sublimation ink applied, etc.

[0225] (2) Pretreatment liquid drying process

[0226] The pretreatment liquid drying process is a process of drying the fabric to which the pretreatment liquid has been applied. Furthermore, it is characterized in that, in the pretreatment liquid drying process, the heat source does not come into contact with the fabric.

[0227] When using a pretreatment solution to form an image by sublimating pigments, it is preferable to apply the pretreatment solution evenly and in appropriate amounts to the fabric in order to reduce uneven dyeing.

[0228] Examples of methods for uniformly and appropriately applying the pretreatment solution include immersing the fabric in the pretreatment solution and applying it to the fabric using an inkjet printing method. Furthermore, by drying the fabric after applying the pretreatment solution, it is possible to prevent the pretreatment solution from being carried over into subsequent processes (such as the process of applying sublimation dyes), thereby improving productivity.

[0229] The inventors studied the prior art and found that, according to the drying method of the fabric, the fabric could not be dried evenly and uneven drying occurred.

[0230] Furthermore, the inventors conducted repeated research and found that these problems are more likely to occur in contact drying methods and less likely to occur in non-contact drying methods. The following is a comparative explanation of contact and non-contact drying methods.

[0231] Methods for drying fabrics can be broadly categorized into contact drying, which involves bringing a heat source into contact with the fabric, and non-contact drying, which involves bringing a heat source into contact with the fabric.

[0232] In contact drying processes, heat is easily transferred to areas of the fabric closer to the heat source, making drying easier. However, heat is difficult to transfer to areas farther from the heat source, hindering drying. Therefore, uneven drying can easily occur due to the difference in distance from the heat source.

[0233] Furthermore, since the heat source comes into contact with the fabric, and the overall temperature of the heat source is uneven, the heated fabric will also experience uneven temperature, which can easily lead to uneven drying.

[0234] For example, when drying a fabric by contacting its surface with a heating plate, uneven concentration of the pretreatment liquid occurs in the thickness direction of the fabric, and the heated fabric also experiences uneven temperature due to the uneven temperature of the heating plate itself, which easily leads to uneven drying.

[0235] Furthermore, the ends of the heating plate (the ends of the heat source) are in contact with the outside air, allowing heat and steam to escape easily, thus facilitating drying. Consequently, uneven drying is likely to occur in the fabric, particularly in the parts that dry in contact with the ends of the heating plate versus those that dry in contact with the center of the heating plate.

[0236] On the other hand, in non-contact drying, the distance from the heat source is overwhelmingly greater than in contact drying, resulting in minimal uneven drying due to the difference in distance. Furthermore, the fabric can be heated at a uniform temperature throughout, thus facilitating even drying.

[0237] Furthermore, since the heat source does not come into contact with the fabric, even if the overall temperature of the heat source is uneven, the heated fabric is less likely to experience uneven temperature, and as a result, it is less likely to experience uneven drying.

[0238] Furthermore, in the non-contact process, drying can be carried out relatively slowly by appropriately adjusting conditions such as drying temperature and time, thus making it easy to remove residual pretreatment liquid with high precision. In addition, it can suppress rapid evaporation of the pretreatment liquid.

[0239] From the viewpoint of drying in a shorter time and avoiding uneven drying, it is preferable to heat the fabric, and the heating temperature is preferably in the range of 100~200℃.

[0240] Methods for drying fabrics by heating them in a non-contact manner include warm air, electric heaters, and infrared heaters.

[0241] (2.1) Drying based on warm air circulation

[0242] In the pretreatment liquid drying process of the present invention, it is preferable to use circulating warm air to dry the fabric.

[0243] By circulating warm air to dry the fabric, the temperature inside the drying unit can be maintained evenly. Furthermore, the gaseous components of the evaporated pretreatment liquid can be easily removed from the drying unit (exhaust).

[0244] Figure 3 This is a schematic diagram illustrating an example of the structure of a drying section that uses circulating warm air to dry fabrics.

[0245] The pretreatment liquid drying section 10 dries the fabric that has been given the pretreatment liquid. The fabric C1 given the pretreatment liquid is fed into the drying chamber 12 along the fabric conveying direction and dried by circulating warm air (solid arrow) in the drying chamber 12. The fabric C2 given an appropriate amount of pretreatment liquid is then sent out of the drying chamber 12.

[0246] It should be noted that the fabric is preferably designed to be inside the drying chamber and not in contact with the guide rollers, conveyor surfaces, etc. that provide support, but it can be supported by guide rollers, conveyor surfaces, etc. outside the drying chamber.

[0247] The drying chamber 12 of the pretreatment liquid drying section 10 is connected to the warm air circulation path 15. The circulation path 15 includes a heat source 13 for continuously heating the circulating air and maintaining the circulating warm air at a constant temperature, and a blower 14 for circulating the warm air. Additionally, a pressure regulating unit (not shown) for adjusting the air pressure of the circulating warm air may also be included. Examples of pressure regulating units include variable dampers and output regulating devices for variable frequency blowers.

[0248] Circulating warm air along Figure 3 The solid arrow shown circulates within the loop path 15. Specifically, warm air from the blower 14 comes into contact with the fabric and then circulates in a direction parallel to the fabric's transport direction to dry it. In this way, by circulating the warm air in a direction parallel to the fabric's transport direction, it is possible to prevent the fabric from pilling or breaking.

[0249] Examples of heat sources 13 include electric heaters, gas heaters, infrared heaters, and heat transfer medium heaters. The temperature of the warm air is detected by a thermometer located at any point within the drying chamber 12, and the output of the heat source is adjusted based on the detection result, thereby maintaining a constant temperature for the circulating warm air.

[0250] The pretreatment liquid drying section 10 draws air from the suction section 11 into the drying chamber 12 and discharges it to the outside of the drying chamber. This removes the gaseous components of the evaporated pretreatment liquid. The suction section preferably includes, for example, a suction fan.

[0251] The suction port 11a (suction position) of the suction section 11 is preferably located on the side opposite to the circulation path 15, separated by a cloth. Thus, the gaseous components of the pretreatment liquid evaporating from the cloth travel along... Figure 3 The arrows shown by the dashed lines flow in the direction away from the heat source 13 along with the air into the suction port 11a and are discharged from the drying chamber 12. The suction unit 11 may also have a mechanism for capturing and removing a given component from the suction air.

[0252] The suction speed is preferably adjusted appropriately in a way that fully attracts the gaseous components of the pretreated liquid that has evaporated while keeping the temperature of the circulating warm air constant. Specifically, it is preferable to adjust the speed so that the air velocity on the surface of the fabric that imparts the sublimation dye is in the range of 0.1 to 10.0 m / sec.

[0253] The drying chamber 12 may be provided with an opening for conveying fabrics. It is preferably provided in a way that does not significantly disrupt the temperature or airflow inside the drying chamber 12. For example, it is preferable to have a mechanism that can adjust the opening area as needed, or a sealing structure for reducing the amount of ventilation inside and outside the drying chamber.

[0254] In addition, to reduce the uneven airflow velocity of the warm air in the drying chamber 12, a rectifier plate can be installed in the drying chamber 12 or the circulation path 15.

[0255] When dirt accumulates during drying, it is necessary to prevent the dirt from adhering to the fabric. Therefore, it is preferable to provide a dirt-collecting mechanism within the circulation path 15. Examples of dirt-collecting components include metallic filters and washers, and the appropriate type is preferably selected based on the type of dirt generated.

[0256] From the viewpoint of removing the remaining pretreatment liquid with high precision, it is preferable to adjust the temperature of the heat source and keep the temperature of the surface of the fabric to which the sublimation dye is applied within the range of 100~200°C.

[0257] From the viewpoint of suppressing uneven drying of fabrics, it is preferable to reduce temperature unevenness within the drying chamber. Specifically, the difference between the highest and lowest temperatures within the drying chamber is preferably 15°C or less, more preferably 10°C or less, and even more preferably 5°C or less. It should be noted that by using a mechanism capable of rectifying warm air and by constructing the pretreatment liquid drying section from a material with excellent thermal insulation properties, temperature unevenness within the drying chamber can be reduced.

[0258] The direction of the warm air is preferably parallel to the direction of fabric transport, specifically within ±30°. Furthermore, the air velocity is preferably in the range of 2 to 10 m / s. A velocity of 2 m / s or higher can reduce uneven temperature distribution of the warm air, while a velocity of 10 m / s or lower can suppress damage to the fabric.

[0259] The drying time of the fabric, i.e., the time the fabric remains in the drying chamber, is preferably within the range of 10 to 300 seconds. Within this range, residual pretreatment liquid can be removed with high precision.

[0260] (3) Sublimation color material application process

[0261] The sublimation dyeing process is the process of applying sublimation dyes to fabrics.

[0262] In this invention, sublimation ink, which contains sublimation pigment, is preferably applied to the fabric.

[0263] (3.1) Sublimation ink

[0264] The sublimation ink of the present invention preferably contains sublimation colorant, and further contains water, organic solvent, dispersant, etc.

[0265] (3.1.1) Composition of sublimation ink

[0266] (3.1.1.1) Sublimation pigments

[0267] In this invention, "sublimation color material" refers to a color material that has the property of sublimation upon heating. Preferably, it is a disperse dye obtained by micronizing and dispersing a dye that is insoluble or sparingly soluble in water in water.

[0268] Here, "insoluble or sparingly soluble in water" means that the solubility in water at 25°C is less than 10 mg / L. It should be noted that, as the sublimation pigment used in this invention, the solubility in water at 25°C is preferably less than 5 mg / L, and more preferably less than 1 mg / L.

[0269] The chemical structure of sublimation pigments is not particularly limited, but it is preferable to have multiple aromatic rings. By having multiple aromatic rings, the π-π interactions between the pigment and the pigment-capturing compound play a strong role, making it easier for the sublimation pigment to be fixed to the fabric.

[0270] Examples of disperse dyes used in sublimation pigments include the following dyes.

[0271] CIDisperseYellow3, 4, 5, 7, 9, 13, 24, 30, 33, 34, 42, 44, 49, 50, 51, 54, 56, 58 ,60,63,64,66,68,71,74,76,79,82,83,85,86,88,90,91,93,98,99,100,104 Numbers 114, 116, 118, 119, 122, 124, 126, 135, 140, 141, 149, 160, 162, 163, 164, 165, 179, 180, 182, 183, 186, 192, 198, 199, 202, 204, 210, 211, 215, 216, 218, 224, etc.

[0272] CIDisperseOrange 1, 3, 5, 7, 11, 13, 17, 20, 21, 25, 29, 30, 31, 32, 33, 37, 38, 42, 43, 44, 45, 47, 48, 49, 50, 53, 54, 55, 56, 57, 58, 59, 61, 66, 71, 73, 76, 78, 80, 89, 90, 91, 93, 96, 97, 119, 127, 130, 139, 142, etc.

[0273] CIDisperseRed1, 4, 5, 7, 11, 12, 13, 15, 17, 27, 43, 44, 50, 52, 53, 54, 55, 56, 58, 59, 60, 65, 72, 73, 74, 75, 76, 78, 81, 82, 86, 88, 90, 91, 92, 93, 96, 103, 105, 106, 107, 108, 110, 111, 113, 117, 118, 121, 122, 126, 127, 128, 131, 132, 134, 135, 137, 143, 145, 14 6, 151, 152, 153, 154, 157, 159, 164, 167, 169, 177, 179, 181, 183, 184, 185, 188, 189, 190, 191, 192, 200, 201, 202, 203, 205, 206, 207, 210, 221, 224, 225, 227, 229, 239, 240, 257, 258, 277, 278, 279, 281, 288, 289, 298, 302, 303, 310, 311, 312, 320, 324, 328, etc.

[0274] CIDisperseViolet1, 4, 8, 23, 26, 27, 28, 31, 33, 35, 36, 38, 40, 43, 46, 48, 50, 51, 52, 56, 57, 59, 61, 63, 69, 77, etc.

[0275] CIDisperseGreen9, etc.

[0276] CIDisperseBrown 1, 2, 4, 9, 13, 19, etc.

[0277] CIDisperseBlue3, 7, 9, 14, 16, 19, 20, 26, 27, 35, 43, 44, 54, 55, 56, 58, 60, 62, 64, 71, 72, 73, 75, 79, 81, 82, 8 3, 87, 91, 93, 94, 95, 96, 102, 106, 108, 112, 113, 115, 118, 120, 122, 125, 128, 130, 139, 141, 142, 143, 146, 148 149, 153, 154, 158, 165, 167, 171, 173, 174, 176, 181, 183, 185, 186, 187, 189, 197, 198, 200, 201, 205, 207, 211, 214, 224, 225, 257, 259, 267, 268, 270, 284, 285, 287, 288, 291, 293, 295, 297, 301, 315, 330, 333, 359, 360, etc.

[0278] CIDisperseBlack1, 3, 10, 24, etc.

[0279] Among them, CIDisperseYellow54, CIDisperseOrange25, CIDisperseRed60, CIDisperseBlue14, 359 and 360 are preferred.

[0280] The molecular weight of sublimation dyes is not particularly limited. From the viewpoint of making it easier for sublimation dyes to sublimate, a small molecular weight (e.g., in the range of 200 to 350) is preferred. On the other hand, from the viewpoint of making it less likely for sublimation dyes that have penetrated into the fabric to come off, a moderately large molecular weight (e.g., in the range of 350 to 500) is preferred.

[0281] The sublimation pigments contained in sublimation inks may or may not crystallize.

[0282] The average particle size of the sublimation pigment in sublimation ink is not particularly limited, but from the viewpoint of injection stability in inkjet printing, it is preferably below 300 nm. The average particle size can be determined using a commercially available particle size analyzer that employs light scattering, electrophoresis, laser Doppler, or similar methods. For example, the ZETASIZER1000 manufactured by MALVERN Corporation can be used as a particle size analyzer.

[0283] The content of sublimation pigment is not particularly limited, but it is preferably in the range of 2 to 10% by mass relative to the total mass of the sublimation ink. With a content of 2% or more of sublimation pigment, it is easier to form high-concentration images. Furthermore, with a content of 10% or less, the viscosity of the sublimation ink will not become excessively high, thus minimizing the impact on injection stability. From the same perspective, the content of sublimation pigment relative to the total mass of the sublimation ink is more preferably in the range of 5 to 10% by mass.

[0284] (3.1.1.2) Water

[0285] Sublimation inks can also contain water. Examples of water include ion-exchanged water, distilled water, and pure water.

[0286] The water content relative to the total mass of the sublimation ink is preferably in the range of 40 to 98% by mass, and more preferably in the range of 50 to 70% by mass.

[0287] (3.1.1.3) Organic solvents

[0288] Sublimation inks may also contain organic solvents, preferably water-soluble organic solvents.

[0289] The total content of water and water-soluble organic solvents relative to the total mass of the sublimation ink is preferably in the range of 90 to 98% by mass, and more preferably in the range of 90 to 95% by mass.

[0290] Examples of water-soluble organic solvents include alcohols (e.g., methanol, ethanol, propanol, pentanol, hexanol, cyclohexanol, benzyl alcohol), polyols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, glycerol, compounds represented by the following general formula (1)), and polyol ethers (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether). Propylene glycol monomethyl ether, propylene glycol monoethyl ether), amines (e.g., ethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine), amides (e.g., formamide, N,N-dimethylformamide, N,N-dimethylacetamide), heterocyclic compounds (e.g., 2-pyrrolidone, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, 2-oxazolidinone, 1,3-dimethyl-2-imidazolidine), sulfoxides (e.g., dimethyl sulfoxide), sulfones (e.g., sulfolane).

[0291] [Chemical Formula 3]

[0292]

[0293] In general formula (1), R 11All represent ethylene glycol or propylene glycol groups, x, y, and z are all positive integers, and x + y + z = 3 to 30.

[0294] When the fabric contains hydrophilic fibers such as natural fibers or synthetic cellulose fibers, from the viewpoint of promoting the penetration of sublimation ink into the fabric and from the viewpoint of not easily impairing the injection stability in inkjet printing, it is preferable that the sublimation ink does not thicken due to drying. Therefore, in the water-soluble organic solvent, the sublimation ink preferably contains a high-boiling-point solvent with a boiling point of 200°C or higher.

[0295] Examples of high-boiling-point solvents with boiling points above 200°C include polyols and polyoxyalkylene compounds. Examples of polyols with boiling points above 200°C include binary alcohols such as 1,3-butanediol (boiling point 208°C), 1,6-hexanediol (boiling point 223°C), and polypropylene glycol; and trimethylols or more than three-membered alcohols such as glycerol (boiling point 290°C) and trimethylolpropane (boiling point 295°C). Examples of polyepoxides with boiling points above 200°C include diethylene glycol monoethyl ether (boiling point 202°C), triethylene glycol monomethyl ether (boiling point 245°C), tetraethylene glycol monomethyl ether (boiling point 305°C), and tripropylene glycol monoethyl ether (boiling point 256°C); as well as ethers of diols such as polypropylene glycol, and ethers of tertiary or higher alcohols such as glycerol (boiling point 290°C) and hexanetriol.

[0296] The content of water-soluble organic solvent relative to the total mass of sublimation ink is preferably in the range of 20% to 70% by mass. By making the content of water-soluble organic solvent relative to the total mass of sublimation ink 20% or more, it is easy to further improve the dispersibility of sublimation pigments and the injection stability of sublimation ink in inkjet printing. By making the content of water-soluble organic solvent relative to the total mass of sublimation ink less than 70% by mass, it is less likely to impair the drying properties of sublimation ink.

[0297] (3.1.1.4) Dispersant

[0298] Sublimation inks may also contain dispersants, which can be selected depending on the type of sublimation pigment.

[0299] Examples of dispersants include formalin condensates of sodium creosote sulfonate, formalin condensates of sodium cresol sulfonate and sodium 2-naphthol-6-sulfonate, formalin condensates of sodium cresol sulfonate, formalin condensates of sodium phenol sulfonate, formalin condensates of sodium β-naphthol sulfonate, formalin condensates containing sodium β-naphthol sulfonate and sodium β-naphthol sulfonate, alkylene oxides containing ethylene oxide and propylene oxide, fatty alcohols, fatty amines, fatty acids, phenols, alkylating compounds containing alkylphenols and carboxylic amines, lignin sulfonates, sodium paraffin sulfonate, copolymers of α-olefins and maleic anhydride, and known comb-type block polymers.

[0300] Examples of comb-type block polymers include DISPERBYK-190, DISPERBYK-194N, DISPERBYK-2010, DISPERBYK-2015 and BYK-154 manufactured by BYK-CHEMIE ("DISPERBYK" and "BYK" are registered trademarks of the company).

[0301] The content of the dispersant is not particularly limited, but is preferably in the range of 20% to 200% by mass relative to the total mass of the sublimation pigment. By making the dispersant content 20% by mass or more, the dispersibility of the sublimation pigment is more easily improved, and by making the dispersant content 200% by mass or less, the decrease in the injection stability of the sublimation ink in inkjet printing is more easily suppressed.

[0302] (3.1.1.5) Other components

[0303] Sublimation inks may also contain other components besides those mentioned above, as needed. Examples of other components include surfactants, preservatives, and pH adjusters; the same substances as those used in the pretreatment solution can be used.

[0304] (3.1.2) Physical properties of sublimation ink

[0305] The viscosity of the sublimation ink at 25°C is not particularly limited, as long as it improves the injection stability based on the inkjet method. It is preferably in the range of 3–20 mPa·s, and more preferably in the range of 4–12 mPa·s. The viscosity of the ink can be measured at 25°C using an E-type viscometer.

[0306] (3.2) Methods for applying sublimation ink

[0307] There are no particular limitations on the method of applying sublimation pigments. It can be sublimation transfer printing, direct printing, or other methods. Among these, sublimation transfer printing is preferred.

[0308] That is, preferably, the process of applying sublimation pigment includes a process of transferring a transfer image formed by applying ink containing sublimation pigment to a transfer medium to a fabric.

[0309] (3.2.1) Sublimation transfer method

[0310] In the sublimation transfer method, an image for transfer, formed by applying ink containing sublimation pigment (sublimation ink) to a transfer medium, is transferred onto a fabric that has been given an appropriate amount of pretreatment liquid, thus forming an image on the fabric.

[0311] It should be noted that the term "image" generally refers to an image obtained by visually fixing an event on a medium. In this invention, it includes images, characters, patterns, pictures, etc., that are colored with a single color.

[0312] The image forming method of the present invention comprises, in sequence, a pretreatment liquid application step, a pretreatment liquid drying step, and a sublimation pigment application step. That is, in the sublimation transfer method, a pretreatment liquid is applied to the fabric, the fabric is dried, and then the transfer image is transferred onto the fabric. The transfer image can be prepared in parallel with the pretreatment liquid application step and the pretreatment liquid drying step, or it can be prepared in advance.

[0313] In image formation based on sublimation transfer, sublimation ink is first applied to a transfer medium and then dried to form a transfer image (ink layer) corresponding to the image formed on the fabric. The method of applying the sublimation ink is not particularly limited, but inkjet printing is preferred from the perspective of forming images with high precision.

[0314] As a transfer medium used in image formation based on sublimation transfer, there are no particular limitations as long as the transfer medium can form a transfer image on its surface and can transfer the transfer image to fabric. Specifically, there are no particular limitations as long as the transfer medium does not hinder the sublimation of the sublimation pigment during transfer. As a transfer medium, paper with an ink-receiving layer formed on its surface by inorganic particles such as silica is preferred, and examples include inkjet paper and transfer paper.

[0315] Next, the surface of the transfer image on the transfer medium is brought into contact with the fabric after the pretreatment liquid drying process, and heated and pressurized (hot pressing). As a result, the sublimation pigment in the transfer image formed on the transfer medium is sublimated and transferred to the fabric, forming an image on the fabric.

[0316] Methods for conveying fabric during heating and pressurization can be broadly categorized into flat type and continuous (linear) type, depending on the shape of the heating and pressurizing components. In the flat type, a plate-shaped component is used to heat and pressurize at regular intervals. On the other hand, in the continuous type, a roll-shaped component is used to continuously heat and pressurize.

[0317] In this invention, the method of conveying the fabric during heating and pressurization is not particularly limited. When forming an image on a long strip of fabric, such as a roller-shaped fabric, a continuous method is preferred from the viewpoint of suppressing uneven dyeing.

[0318] The transfer temperature (hot pressing temperature) also depends on the sublimation temperature of the sublimation pigment, preferably in the range of 180~210°C. The pressing pressure, in the case of a flatbed printing press, is preferably 200~500 g / cm². 2 Within this range, in the case of continuous operation, 2~6 kg / cm² is preferred. 2 The pressing time also depends on the transfer temperature and pressing pressure, preferably within the range of 30 to 180 seconds.

[0319] (3.2.2) Direct method

[0320] In the direct method, after the sublimation pigment is directly applied to the fabric, the vaporized sublimation pigment is fixed to the fabric by heating the fabric to form an image.

[0321] There are no particular limitations on the method of directly applying sublimation pigments to fabrics. Well-known methods can be used, such as spraying, padding (padding or impregnation), coating, inkjet printing, etc.

[0322] Furthermore, there are no particular limitations on the method for heating the sublimation pigment; known methods can be used, such as warm air, electric heaters, and infrared heaters. Additionally, various heaters can be plate-shaped or roller-shaped.

[0323] (4) Conditions for introducing organic solvents into the pretreatment solution

[0324] From the viewpoint of high dyeability of fabrics and the ability to suppress yellowing during heating and discoloration under high humidity, the pretreatment solution preferably contains an organic solvent containing nitrogen or sulfur. Furthermore, it is preferable that the amount of organic solvent applied immediately after the pretreatment step is in the range of 10-150% by mass relative to the total mass of the fabric, and that the remaining amount of organic solvent in the transfer printing step, before transferring ink containing sublimation pigment to the fabric, is in the range of 3-40% by mass relative to the total mass of the fabric.

[0325] That is, in each of the steps described above, it is preferable to satisfy the conditions for applying the organic solvent. Hereinafter, each step when the conditions for applying the organic solvent are satisfied will be described separately.

[0326] It should be noted that, in this specification, "the mass of the fabric as a whole" does not refer to the mass of the fabric as a whole to which the pretreatment liquid is to be applied (for example, the mass of the roll as a whole in the case of pulling out the fabric wound into a roll to apply the pretreatment liquid), but rather to the mass of each fixed area of ​​the fabric as a part of the fabric to which the pretreatment liquid is to be applied, as the total mass, that is, the mass of the fabric itself per unit area.

[0327] Therefore, the amount of organic solvents, etc., applied is expressed as a relative value (mass%), where the total mass of the unit area is 100% by mass and the mass of the organic solvents, etc., applied to the unit area is a relative value (mass%).

[0328] (4.1) Composition of the pretreatment solution

[0329] The pretreatment solution of the present invention is a pretreatment solution for dyeing and printing by sublimation transfer. For fabrics containing natural fibers, synthetic cellulose fibers, etc., which exhibit hydrophilicity, it has the function of expanding the gaps between fibers by causing the fabric to swell, making it easier for sublimation dyes to enter the interior of the fibers. As a solvent, it is preferable to contain an organic solvent containing nitrogen or sulfur.

[0330] (4.1.1) Solvent

[0331] The solvent contained in the pretreatment liquid of the present invention acts as a carrier for the transferred dye, making it easier for the dye to penetrate into the fiber, and by containing an organic solvent containing nitrogen or sulfur, it has the effect of easily capturing the dye in the sublimation ink between the fibers of the fabric that has been moderately swollen due to the pretreatment liquid.

[0332] (Organic solvents containing nitrogen or sulfur)

[0333] Examples of organic solvents containing nitrogen or sulfur include amides such as N-methylformamide, N,N-dimethylformamide, N-methylacetamide, dimethylacetamide, N,N-dimethylacetamide, N-methoxy-N-methylacetamide, N-ethylacetamide, and N,N-diethylacetamide; heterocyclic compounds such as 1,3-dimethyl-2-imidazolidineone, N-methyl-2-pyrrolidone, 2-pyrrolidone, and 1-methyl-2,5-pyrrolidone; and sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide.

[0334] Among them, N-methylacetamide, 1,3-dimethyl-2-imidazolium ketone, dimethyl sulfoxide, and 2-pyrrolidone are preferred because they can cause the fabric fibers to swell and have high dye solubility, thus enabling the fabric to be dyed at high concentrations.

[0335] (Boiling point of organic solvents and temperature during the drying process of fabrics)

[0336] By keeping the temperature in the drying process of the fabric (hereinafter also referred to as the "drying process") below the boiling point of the organic solvent of the present invention, the organic solvent is easily left in the interior of the fabric in an amount within an optimal range.

[0337] The temperature in the drying process described later is preferably in the range of 100 to 200°C. From the viewpoint of preventing yellowing of the fabric caused by drying heat, it is particularly preferred to be in the range of 100 to 130°C. Therefore, the boiling point of the organic solvent is preferably higher than 130°C and lower than 260°C.

[0338] Examples of solvents with boiling points above 130°C and below 260°C include N-methylacetamide (165°C), 1,3-dimethyl-2-imidazolium ketone (225°C), dimethyl sulfoxide (189°C), and 2-pyrrolidone (245°C).

[0339] (Other organic solvents)

[0340] As a solvent, it may contain other organic solvents besides the organic solvents containing nitrogen or sulfur. From the viewpoint of moisturizing properties and viscosity adjustment, it is preferable to contain water-soluble organic solvents.

[0341] Especially when the pretreatment solution is applied to the fabric using an inkjet printer, the pretreatment solution preferably also contains a water-soluble organic solvent. The water-soluble organic solvent can be used.

[0342] The fabric of the present invention contains hydrophilic fibers. Therefore, from the viewpoint of promoting the penetration of the pretreatment liquid into the fabric and from the viewpoint of not easily damaging the ejection stability under inkjet mode, it is preferable to contain a high-boiling-point water-soluble organic solvent that does not easily thicken due to drying of the pretreatment liquid.

[0343] The boiling point is preferably above 200℃, and it is preferably a polyol or polyepoxide.

[0344] Examples of polyols with a boiling point above 200°C include: diols such as 1,3-butanediol (boiling point 208°C), 1,6-hexanediol (boiling point 223°C), and polypropylene glycol; and ternary or higher alcohols such as glycerol (boiling point 290°C) and trimethylolpropane (boiling point 295°C).

[0345] Examples of polyepoxides with a boiling point above 200°C include: 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); as well as ethers of binary alcohols such as polypropylene glycol, glycerol (boiling point 290°C), and ethers of ternary or higher alcohols such as hexanetriol.

[0346] (4.1.2) Amount of organic solvent added immediately after the pretreatment solution is applied

[0347] Immediately after the pretreatment process is completed, the amount of organic solvent applied to the fabric is in the range of 10% to 150% by mass relative to the total mass of the fabric.

[0348] From the viewpoint of staining concentration, the amount applied is preferably in the range of 5 to 95% by mass, and more preferably in the range of 15 to 50% by mass.

[0349] In the following, when preparing the transfer medium in the sublimation color material application process, if the sublimation ink contains organic solvents, and it is necessary to distinguish the organic solvents contained in the sublimation ink from the organic solvents contained in the pretreatment liquid, the organic solvents contained in the pretreatment liquid will be referred to as "organic solvent α", and the organic solvents contained in the sublimation ink will be referred to as "organic solvent β".

[0350] It should be noted that, for example, when the pretreatment liquid of the present invention is coated by inkjet printing, the amount of organic solvent α applied to the fabric is the amount of coating itself. Furthermore, when coating is performed by padding, the amount of organic solvent α applied to the fabric is the amount of organic solvent α contained per unit area of ​​the fabric after the fabric is coated with the organic solvent and then squeezed.

[0351] By applying the organic solvent to the fabric within the specified range, the fabric swells, the gaps between fibers widen, and thus the sublimated dye can easily penetrate into the fiber interior, increasing the dyeing concentration during sublimated ink transfer.

[0352] (4.1.3) Other components

[0353] From the viewpoint of easily capturing dyes in sublimated inks within the fibers of fabric and increasing dyeing concentration, the pretreatment solution of the present invention preferably contains aromatic heterocyclic compounds.

[0354] In addition to the solvents and aromatic heterocyclic compounds mentioned above, other components may be further included as needed, such as surfactants, preservatives, pH adjusters, and water.

[0355] (Aromatic heterocyclic compounds)

[0356] From the viewpoint of easily capturing dyes in sublimated inks within the fibers of fabric and increasing dyeing concentration, the pretreatment solution of the present invention preferably contains aromatic heterocyclic compounds.

[0357] It should be noted that, in this invention, "aromatic heterocyclic compound" refers to a compound that is composed of carbon and heteroatoms other than carbon as the elements constituting the aromatic ring and has aromatic properties, excluding cases where the elements constituting the aromatic ring are only carbon and heteroatoms constitute substituents on the aromatic ring.

[0358] Regarding the aromatic heterocyclic compound of the present invention, from the viewpoint of easily capturing dyes in sublimated inks, it is preferable that the heteroatoms constituting the aromatic ring are selected from oxygen, nitrogen, and sulfur atoms, and more preferably nitrogen atoms.

[0359] From the viewpoint of dye capture capacity, the content of the aromatic heterocyclic compound of the present invention is preferably in the range of 1 to 30% by mass, and more preferably in the range of 10 to 20% by mass, relative to the pretreatment liquid as a whole.

[0360] From the viewpoint of capturing dyes within the fibers of fabric, the aromatic heterocyclic compound is preferably of low molecular weight.

[0361] The low molecular weight is, for example, in the range of 200 to 1000.

[0362] Furthermore, from the viewpoint of dye capture, the content of the aromatic heterocyclic compound is preferably in the range of 1 to 30% by mass, and more preferably in the range of 10 to 20% by mass, relative to the pretreatment liquid as a whole.

[0363] Examples of such aromatic heterocyclic compounds include compounds having pyrazole, triazole, imidazole, triazine, pyridine, indole, quinoline, pyrrole, thiophene, and thiazole rings. From the viewpoint of replenishing dyes in sublimation inks, at least one compound having pyrazole, triazole, and imidazole rings is particularly preferred.

[0364] As an aromatic heterocyclic compound, it is preferred to have three or more aromatic rings, and more preferably five or more aromatic rings.

[0365] Furthermore, a structure consisting of two aromatic rings bonded together by single bonds is preferred as part or as a whole.

[0366] If the aromatic heterocyclic compound has these structures, its aromaticity increases, and therefore its π-π interaction with sublimated dyes becomes stronger.

[0367] Therefore, the dye capturing power is improved, which can enhance the effect of inhibiting discoloration / fading.

[0368] The solubility of the aromatic heterocyclic compound of the present invention in a solvent also contained in the pretreatment solution at 25°C and 1 atmosphere is preferably 10% by mass or more.

[0369] The higher the solubility in the solvent, the easier it is for aromatic heterocyclic compounds to enter the fabric fibers in a dissolved state, thus improving dye capture and color change / fading inhibition.

[0370] Specifically, for example, the exemplary compounds (1) to (13) represented by the structural formula can be cited.

[0371] It should be noted that the aromatic heterocyclic compounds of the present invention are not limited to these.

[0372] (surfactant)

[0373] There are no particular limitations on the type of surfactant. When the ink contains anionic compounds, the surfactant is preferably anionic, nonionic, or betaine-type.

[0374] Specifically, it is preferable to use fluorinated or polysiloxane surfactants with high static surface tension reduction capabilities, anionic surfactants such as dioctyl sulfosuccinate and sodium dodecyl sulfate with high dynamic surface tension reduction capabilities, and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, ethynyl glycols, PLURONIC-type surfactants (PLURONIC is a registered trademark), and sorbitan derivatives.

[0375] In addition, it is preferable to use fluorinated or polysiloxane surfactants in combination with surfactants that have a high ability to reduce dynamic surface tension.

[0376] (preservative)

[0377] Examples of preservatives include aromatic halogen compounds (e.g., "Preventol CMK"), methylene dithiocyanate, halogenated nitrogen and sulfur compounds, and 1,2-benzisothiazolin-3-one (e.g., "PROXELGXL").

[0378] (pH adjuster)

[0379] Examples of pH adjusters include citric acid, sodium citrate, hydrochloric acid, and sodium hydroxide.

[0380] (water)

[0381] There are no specific restrictions on the type of water; it can be ion-exchanged water, distilled water, or pure water.

[0382] The water content in the pretreatment solution is preferably in the range of 0 to 95% by mass, and more preferably in the range of 0 to 50% by mass.

[0383] (4.1.4) Physical properties of the pretreatment solution

[0384] The viscosity of the pretreatment solution at 25°C can be adjusted appropriately according to the method of application to the fabric.

[0385] For example, when the pretreatment liquid is applied by inkjet printing, the viscosity of the pretreatment liquid is preferably in the range of 4 to 20 mPa·s.

[0386] The viscosity of the pretreatment solution can be measured at 25°C using an E-type viscometer.

[0387] (4.2) Pretreatment liquid drying process

[0388] As described in the "Pretreatment Liquid Drying Process" section above.

[0389] In the process of drying the fabric (drying process), after the pretreatment liquid is applied to the fabric as described above, the coating of the pretreatment liquid applied to the fabric is dried, thereby removing excess liquid medium (referring to organic solvents and water).

[0390] Then, the fabric is transferred with ink containing sublimation pigment (sublimation ink), preferably controlled in the drying process, and the residual amount of the organic solvent before transferring the sublimation ink to the fabric is in the range of 3 to 40% by mass relative to the total mass of the fabric.

[0391] It should be noted that, as mentioned above, when the organic solvent contained in the pretreatment liquid is designated as "organic solvent α" and the organic solvent contained in the sublimation ink is designated as "organic solvent β", the organic solvent α and the organic solvent β can also be the same type of organic solvent.

[0392] Furthermore, in this specification, "the remaining amount of the organic solvent before the sublimation ink is transferred to the fabric" refers to "the remaining amount of the organic solvent α before the sublimation ink is transferred to the fabric".

[0393] However, the "residual amount of organic solvent before the sublimation ink is transferred to the fabric" does not include the amount of organic solvent β contained in the sublimation ink when preparing the transfer medium in the sublimation colorant application process.

[0394] (4.3) Sublimation color material application process

[0395] As described in the aforementioned "Sublimation Color Imparting Process".

[0396] After the fabric containing the pretreatment liquid of the present invention is given the pretreatment liquid as described, by further removing the excess pretreatment liquid in the pretreatment liquid drying process, it is possible to obtain the effect of suppressing yellowing of the white background of the transferred image and discoloration of sublimation ink under high humidity environment.

[0397] To achieve the desired effect, it is preferable to control the amount of pretreatment liquid during the pretreatment liquid drying process, and to ensure that the remaining amount of the organic solvent before transferring the sublimation ink to the fabric is within the range of 3 to 40% by mass relative to the total mass of the fabric during the transfer printing process.

[0398] It should be noted that the "remaining amount of organic solvent before transferring the sublimation ink to the fabric" refers to the remaining amount of organic solvent α immediately after the pretreatment liquid drying process is completed.

[0399] 3. Image forming apparatus

[0400] The image forming apparatus of the present invention is an image forming apparatus that forms an image on a fabric by sublimation pigment, characterized in that it comprises: a mechanism for applying a pretreatment liquid to the fabric; a mechanism for drying the fabric; and a mechanism for applying the sublimation pigment to the fabric, wherein in the drying mechanism, a heat source does not come into contact with the fabric.

[0401] As mentioned above, there are no particular limitations on the method of applying sublimation pigments. It can be a sublimation transfer method, a direct method, or other methods, among which the sublimation transfer method is preferred.

[0402] That is, preferably, the mechanism for imparting the sublimation pigment has the following features: a mechanism for transferring a transfer image formed by applying ink containing the sublimation pigment to the transfer medium onto the fabric.

[0403] (1) Sublimation transfer method

[0404] Figure 1 This is a schematic diagram of the image forming apparatus (sublimation transfer method, continuous type) of the present invention. Figure 1 The present invention illustrates an example in which the mechanism for applying a pretreatment liquid to the fabric, the mechanism for drying the fabric, and the mechanism for applying a sublimation dye to the fabric are all mounted in one device. However, the structure of the image forming apparatus of the present invention is not limited to this. For example, each mechanism may be provided as a different device.

[0405] Furthermore, regarding the mechanism for drying the fabric, there are no particular limitations as long as the heat source does not come into contact with the fabric. From the viewpoint of increasing dyeing concentration and reducing uneven dyeing, it is preferable to use circulating warm air to dry the fabric. For example, it is more preferable to set it as follows: Figure 3 The pretreatment liquid drying section is shown.

[0406] Figure 1 The image forming apparatus 400 shown includes: a pretreatment liquid applicator 103 as a mechanism for applicating a pretreatment liquid to fabric, a pretreatment liquid drying unit 104 as a mechanism for drying the fabric, an inkjet recording unit 203 as a mechanism for applicating sublimation pigment to the fabric, an ink drying unit 204, and a transfer unit 301. Furthermore, as... Figure 1 As shown, other components or devices may be included as needed, such as a peeling section 302, a fabric conveying section 102, and a transfer media conveying section 202.

[0407] The following is about Figure 1 The image forming apparatus 400 shown will be described in detail.

[0408] Image forming apparatus 400 Figure 4 Under the control of the control unit 106 shown, fabric C is conveyed from the fabric feeding unit 101 to the pretreatment liquid application unit 103, where the pretreatment liquid application unit 103 applies pretreatment liquid to the fabric. The fabric C1, which has been applied with an appropriate amount of pretreatment liquid, is further conveyed to the pretreatment liquid drying unit 104, where the fabric is dried. The fabric C2, which has been applied with an appropriate amount of pretreatment liquid, is then conveyed to the transfer unit 301. Then, in the transfer unit 301, the fabric C2, which has been applied with an appropriate amount of pretreatment liquid, and the transfer medium P2, on which the transfer image is formed, are heated and pressurized to perform sublimation transfer. Then, in the peeling unit 302, the fabric N on which the image is formed is peeled off from the heated and pressurized transfer medium P3, and the fabric N on which the image is formed is recovered in the fabric recovery unit 105.

[0409] Fabric C is disposed in fabric delivery section 101, which is located upstream of the pretreatment liquid supply section 103 in the conveying direction. Fabric delivery section 101 includes a rotating shaft for mounting the roller-shaped fabric C and a motor (not shown) that drives the rotating shaft to rotate in a given direction. Fabric delivery section 101 delivers fabric C downstream in the conveying direction by rotating the rotating shaft along the driven motor.

[0410] The fabric conveying unit 102 conveys the fabric C sent out from the fabric delivery unit 101. Figure 1 In this case, a structure is adopted in which the fabric C is conveyed by conveyor rollers, or a structure can be adopted, for example, in which the fabric C is pasted onto a conveyor belt for conveying.

[0411] The fabric recycling section 105 is located downstream of the peeling section 302, and it winds up and recycles the fabric N on which the image is formed.

[0412] Figure 4 This is a block diagram representing a structure that controls the conditions applied to the pretreatment liquid based on fabric information.

[0413] The control unit 106 controls the application conditions of the pretreatment liquid based on the fabric information. Specifically, it is preferable to control the application amount of the pretreatment liquid based on the fabric information.

[0414] The control unit 106 inputs the fabric information (such as the fabric fiber ratio, weight per unit area (mesh weight), and fiber type) entered by the user when operating the operation unit (not shown).

[0415] In addition, the control unit 106 includes a CPU 107, RAM 108, and ROM 109. The CPU 107 reads and executes various programs and data corresponding to the processing content from storage devices such as the ROM 109, and controls the operation of each part of the image forming apparatus 400 according to the processing content being executed. The RAM 108 temporarily stores various programs and data processed by the CPU 107. The ROM 109 stores various programs and data read by the CPU 107 and the like.

[0416] Specifically, the control unit 106 performs the following processing on the image forming apparatus 400.

[0417] The control unit 106 activates the pretreatment liquid application unit 103 based on the fabric information input from the operation unit (not shown), applying pretreatment liquid to the fabric C and setting the amount of pretreatment liquid applied to a given amount. For example, the amount of pretreatment liquid applied is preferably controlled based on the fiber ratio of the fabric C (specifically, the polyester fiber ratio).

[0418] Furthermore, ROM 109 stores, for example, data on the amount of pretreatment liquid applied corresponding to the fiber ratio of fabric C. The data on the amount of pretreatment liquid applied is preferably data calculated based on a mathematical formula based on the fiber ratio, or data on the amount applied based on a threshold value for the fiber ratio.

[0419] As a mathematical expression, examples such as the mathematical expression shown below can be given, but it is not limited to this.

[0420] (Formula) y = -ax + 100a

[0421] In the formula, y represents the amount imparted [g / m]. 2 ], where x is the percentage of polyester fiber (0~100% by mass), and a is the slope (e.g., a=0.4 g / m 2 ])]

[0422] As a threshold for the amount of material to be applied, for example, if the proportion of polyester fibers in the fabric is 0% by mass or more but less than 40% by mass, the amount to be applied is set to 40 g / m. 2 When the polyester fiber content is above 40% but less than 80% by mass, the application rate is set to 20 g / m.2 .

[0423] Furthermore, data based on mathematical formulas and thresholds are preferably corrected by weight per unit area, for example.

[0424] Specifically, the larger the weight per unit area, the greater the amount of material imparted.

[0425] The image forming apparatus 400 delivers a transfer medium P from the transfer medium delivery unit 201 to the inkjet recording unit 203. The inkjet recording unit 203 applies sublimation ink to the transfer medium. The transfer medium P1, which has been coated with sublimation ink, is further delivered to the ink drying unit 204. The ink drying unit 204 dries the fabric, and the transfer medium P2, on which the transfer image is formed, is delivered to the transfer unit 301. Then, in the transfer unit 301, sublimation transfer is performed by heating and pressurizing the fabric C2, on which an appropriate amount of pretreatment liquid has been applied, and the transfer medium P2, on which the transfer image is formed. Then, in the peeling unit 302, the fabric N on which the image is formed is peeled off from the heated and pressurized transfer medium P3, and the heated and pressurized transfer medium P3 is recovered in the transfer medium recovery unit 205.

[0426] A roller-shaped transfer medium P is mounted on the transfer medium delivery section 201. The transfer medium P is delivered by a drive motor (not shown), and at this time, the transfer surface of the transfer medium P (for example, the surface on which the ink receiving layer is formed) is mounted opposite to the inkjet head of the inkjet recording section 203.

[0427] The inkjet recording unit 203 uses an inkjet head to apply sublimation ink to the transfer medium P delivered from the transfer medium delivery unit 201.

[0428] The ink drying section 204 is located downstream of the inkjet recording section 203 to dry the transfer medium P1 which has been coated with sublimation ink.

[0429] The transfer section 301 is preferably configured to include a heating roller 301a having a heat source inside and a pressure roller 301b that is in pressing contact with the heating roller 301a. With such a configuration, sublimation transfer can be performed by continuous heating and pressure.

[0430] It should be noted that, as Figure 1 As shown, the structure of the transfer unit 301 can be a structure in which a fabric C2, to which an appropriate amount of pretreatment liquid has been applied, and a transfer medium P2 on which a transfer image is formed are sandwiched between a heating roller 301a and a pressure roller 301b, or it can be as follows: Figure 5 The schematic diagram of the heating roller in the sublimation transfer method is shown. It is a structure in which the fabric C2, which is given an appropriate amount of pretreatment liquid, and the transfer medium P2 with the transfer image formed are wound on the heating roller 301c.

[0431] Fabric C2, to which an appropriate amount of pretreatment liquid has been applied, and transfer medium P2, on which a transfer image is formed, are overlapped in a laminated state, with their transfer surfaces (the surfaces on which the transfer image is formed) in contact. The laminate is then held by a heating roller 301a and a pressure roller 301b. This process heats and pressurizes the laminate of fabric C2 and transfer medium P2. Consequently, the transfer image on transfer medium P2 is sublimated and transferred to fabric C2, which has been toned with the appropriate amount of pretreatment liquid, resulting in fabric N with the image formed.

[0432] The peeling section 302 is provided downstream of the transfer section 301. The peeling section 302 peels the heated and pressurized transfer medium P3 from the heated and pressurized laminate to obtain a fabric N with an image formed on it.

[0433] A transfer media recovery unit 205 is provided downstream of the peeling unit 302. Then, the used heated and pressurized transfer media P3 that has been peeled off from the laminate in the peeling unit 302 is wound up and recovered.

[0434] (2) Direct method

[0435] Figure 2 This is a schematic diagram of the image forming apparatus (direct method) of the present invention. Figure 2 The present invention illustrates an example in which the mechanism for applying a pretreatment liquid to the fabric, the mechanism for drying the fabric, and the mechanism for applying a sublimation dye to the fabric are all mounted in one device. However, the structure of the image forming apparatus of the present invention is not limited to this. For example, each mechanism may be provided as a different device.

[0436] Furthermore, regarding the mechanism for drying the fabric, there are no particular limitations as long as the heat source does not come into contact with the fabric. From the viewpoint of increasing dyeing concentration and reducing uneven dyeing, it is preferable to use circulating warm air to dry the fabric. For example, it is more preferable to set it as follows: Figure 3 The pretreatment liquid drying section is shown.

[0437] Figure 2 The image forming apparatus 600 shown includes: a pretreatment liquid applicator 103 as a mechanism for applicating a pretreatment liquid to fabric, a pretreatment liquid drying unit 104 as a mechanism for drying the fabric, an inkjet recording unit 501 as a mechanism for applicating sublimation pigment to the fabric, and an ink heating unit 502. Furthermore, as... Figure 2 As shown, other components or devices, such as a fabric conveying unit 102, may also be included as needed.

[0438] The heat source used in the ink heating section 502 can be, for example, an electric heater or an infrared heater. The shape is not particularly limited; it can be plate-shaped or roller-shaped.

[0439] 4. Image Forming System

[0440] The image forming system of the present invention is an image forming system for dyeing fabric containing natural fibers by sublimation transfer. It is characterized by comprising: a mechanism for applying a pretreatment liquid to the fabric; a mechanism for drying the fabric; a mechanism for applying sublimation ink to a transfer medium; and a mechanism for transferring the sublimation ink from the transfer medium to the fabric. In the fabric drying mechanism, the heat source does not contact the fabric. The pretreatment liquid contains an organic solvent containing nitrogen or sulfur as a solvent. Immediately after applying the pretreatment liquid, the amount of the organic solvent applied is in the range of 10% to 150% by mass relative to the total mass of the fabric. Furthermore, in the transfer mechanism, the remaining amount of the organic solvent before transferring the sublimation ink to the fabric is in the range of 3% to 40% by mass relative to the total mass of the fabric.

[0441] Furthermore, the image forming method of the present invention is suitable for use in the image forming system described above.

[0442] Figure 6 This is a schematic diagram illustrating an example of the image recording system of the present invention.

[0443] Figure 6 The image recording system (900) shown is an image recording system for printing and dyeing fabrics using a continuous transfer printing and dyeing method.

[0444] It should be noted that, Figure 6 This is an example of the image recording system (900) of the present invention, but is not limited to this structure.

[0445] The image recording system (900) includes a pretreatment liquid application device (700) and a sublimation ink coating device (800), and also includes a transfer unit (901), a peeling unit (902), a transfer media recovery unit (805), a fabric recovery unit (705), and a control unit (706).

[0446] (1) Mechanism for supplying pretreatment liquid

[0447] As the mechanism for applying the pretreatment liquid according to the present invention, the following pretreatment liquid application device can be used, for example.

[0448] Figure 7 This is a block diagram showing the internal structure of the pretreatment liquid application device (700) of the present invention.

[0449] (Pretreatment liquid dispensing device)

[0450] The pretreatment liquid dispensing device (700) includes: a fabric feeding unit (701), a conveying unit (702), a pretreatment liquid dispensing unit (703), a pretreatment liquid drying unit (704), a fabric recycling unit (705), and a control unit (706).

[0451] Under the control of the control unit (706), the pretreatment liquid application device (700) transports the fabric (C′) from the fabric delivery unit (701) to the pretreatment liquid application unit (703), applies pretreatment liquid to the fabric (C′), and dries the fabric (C′1) with pretreatment liquid applied by the drying unit (704) to prepare fabric (C′2) with excess pretreatment liquid removed (hereinafter also referred to as "fabric (C′2)"). The fabric (C′2) is then transported to the fabric recycling unit (705) located downstream of the peeling unit (902).

[0452] Then, the heat-transfer printed fabric (N′) with the image for transfer that was peeled off in the peeling section (902) is wound up and recycled (hereinafter also simply referred to as "fabric (N′)").

[0453] (Pretreatment solution dispensing section)

[0454] The pretreatment liquid supplied by the pretreatment liquid supply unit (703) contains an organic solvent containing nitrogen or sulfur as a solvent, and the amount of organic solvent supplied after the pretreatment liquid supply is completed is adjusted to be in the range of 10 to 150% by mass relative to the total mass of the fabric.

[0455] Regarding the components of the pretreatment solution, as described above.

[0456] Then, as described later, the image for transfer recorded in the sublimation ink coating apparatus (800) on the transfer medium is transferred to the pretreated surface of the fabric (C′2) (see reference). Figure 6 ).

[0457] Pretreatment solution application method

[0458] The method of application in the pretreatment liquid application section (703) is not particularly limited and can be any of the following: spraying, padding, coating, or inkjet printing.

[0459] For example, from the viewpoint that the process of coating sublimation ink in the sublimation ink coating apparatus (800) described later can be carried out continuously, inkjet method is preferred, and from the viewpoint that a given amount of pretreatment liquid is applied in a short time, padding method and coating machine method are preferred.

[0460] In the liquid-squeezing method, the amount of pretreatment liquid supplied is adjusted by squeezing after the fabric is immersed in a pretreatment liquid stored in a bath.

[0461] There is no particular limitation on the temperature of the pretreatment solution, but it is preferred to be set in the range of 15~30℃.

[0462] (Control Department)

[0463] The control unit (706) controls the coating conditions of the pretreatment liquid based on the fabric information.

[0464] Specifically, it is preferable to control the amount of pretreatment solution applied based on fabric information (such as the fabric's fiber ratio, weight per unit area, and fiber type).

[0465] The control unit (706) inputs the fabric information entered by the user when operating the operation unit (not shown).

[0466] In addition, the control unit (706) includes a CPU (707), RAM (708), and ROM (709). The CPU (707) reads and executes various programs, data, etc., corresponding to the processing content from storage devices such as ROM (709), and controls the operation of each part of the pretreatment liquid applicator (700) according to the processing content being executed.

[0467] RAM (708) temporarily stores various programs, data, etc. processed by the CPU (707).

[0468] The ROM (709) stores various programs and data read by the CPU (707) and other components.

[0469] Specifically, the control unit (706) performs the following processing on the pretreatment liquid dispensing device (700).

[0470] That is, the control unit (706) activates the pretreatment liquid application unit (703) based on the fabric information input from the operation unit (not shown) to apply pretreatment liquid to the fabric (C′) and set the amount of pretreatment liquid applied to a given amount.

[0471] (Clothing and Silk Distribution Department)

[0472] The fabric (C′) is provided in the fabric delivery section (701) located upstream of the pretreatment liquid supply section (703) in the conveying direction.

[0473] The fabric feeding unit (701) includes a rotating shaft for mounting a roller-shaped fabric (C′) and a motor (not shown) for driving the rotating shaft to rotate in a given direction.

[0474] The fabric feeding unit (701) feeds the fabric (C′) downstream in the conveying direction by rotating along the rotating shaft via a drive motor.

[0475] (Conveying Department)

[0476] The conveying unit (702) conveys the cloth (C′) sent out from the cloth delivery unit (701).

[0477] exist Figure 6 In this case, a structure is adopted in which the fabric (C′) is conveyed by conveyor rollers, or a structure can be adopted, for example, in which the fabric (C′) is pasted onto the conveyor belt for conveying.

[0478] (2) A mechanism for drying fabrics

[0479] (Pretreatment solution drying section)

[0480] The pretreatment liquid drying section (704) dries the fabric (C′1) that has been given pretreatment liquid by the pretreatment liquid dispensing section (703) and removes excess pretreatment liquid from the fabric (C′1).

[0481] As a drying mechanism, there are no special limitations as long as the heat source does not come into contact with the fabric.

[0482] The temperature (hereinafter also referred to as "drying temperature") in the mechanism for drying the fabric (C′1) to which the pretreatment liquid has been applied is preferably in the range of 100 to 200°C, and from the viewpoint of preventing yellowing of the fabric caused by drying heat, it is particularly preferably in the range of 100 to 130°C.

[0483] From the viewpoint that the organic solvent can easily remain in the interior of the fabric in an optimal amount, it is preferable that the drying temperature is lower than the boiling point of the organic solvent, and from the viewpoint that it can suppress discoloration caused by heating of the white base of the fabric, it is preferable that the drying temperature is lower than the heating temperature during transfer.

[0484] (Cloth Recycling Department)

[0485] The fabric recycling unit (705) is located downstream of the pretreatment liquid drying unit (704). The pretreatment liquid drying unit (704) heat-transfers the image formed on the transfer medium on the fabric (C′2) through the transfer unit (901) and recycles the fabric (N′) while winding it.

[0486] (3) Mechanism for applying sublimation ink to the transfer medium

[0487] The sublimation ink coating apparatus (800) is an apparatus that applies sublimation ink to a transfer medium via an inkjet recording unit (803), thereby forming an image (ink layer) for transfer. The image for transfer formed on the transfer medium via the transfer unit (901) is then thermally transferred onto the fabric (C′2) via a pretreatment liquid drying unit (704). The remaining used transfer paper substrate (P′3) is then recovered via a transfer medium recovery unit (805).

[0488] Specifically, it includes: a transfer media delivery unit (801), an inkjet recording unit (803), an ink drying unit (804), a transfer unit (901), and a transfer media recovery unit (805).

[0489] Furthermore, it is preferable to have a peeling section (902) and a conveying section (802) for conveying the transfer medium.

[0490] The transfer medium delivery unit (801) is equipped with a roller-shaped transfer paper substrate P′ as the transfer medium.

[0491] When the transfer paper substrate (P′) is fed out by driving a motor (not shown), the transfer surface of the transfer paper substrate (P′) is mounted opposite to the inkjet head of the inkjet recording unit (803).

[0492] The inkjet recording unit (803) uses an inkjet head to form an image (ink image) for transfer on a transfer paper substrate (P′) fed out from the transfer medium delivery unit (801), thereby forming a transfer paper (P′1) for transfer after the image is formed (hereinafter also simply referred to as "transfer paper (P′1)").

[0493] An ink drying section (804) is provided downstream of the inkjet recording section (803) and the transfer paper (P′1) is dried at a temperature lower than the crosslinking temperature of the fixing resin contained in the image (ink image) used for transfer.

[0494] (4) Mechanism for transferring the sublimation ink from the transfer medium

[0495] The transfer section (901) preferably has, for example, a structure comprising a heating roller (901a) having a heat source inside and a pressure roller (901b) that is in pressing contact with the heating roller (901a).

[0496] The transfer paper (P′1) coated with sublimation ink is dried by the ink drying section (804) (hereinafter, the dried transfer paper is also referred to as "transfer paper (P′2)"). By the pretreatment liquid application device (700), in a state where the image surface (the surface on which the image for transfer is formed) is stacked with the fabric (C′2) facing each other, the paper is heated and pressurized by the clamping part of the heating roller (901a) and the pressure roller (901b). The sublimation ink is transferred from the transfer paper (P′2) to the fabric (C′2), forming a transfer image formation, i.e., fabric (N′), on which the image for transfer is thermally transferred.

[0497] At this point, the remaining amount of the organic solvent before transferring the sublimation ink to the fabric (C′2) is adjusted to a range of 3 to 40% by mass relative to the total mass of the fabric (C′2) through the drying process.

[0498] It should be noted that, as mentioned above, "the remaining amount of organic solvent before the transfer of sublimation ink" refers to the remaining amount of organic solvent α used in the pretreatment liquid application process.

[0499] Furthermore, the organic solvent α and the organic solvent β can be the same type of organic solvent.

[0500] However, the "remaining amount of organic solvent before transferring the sublimation ink to the fabric" does not include the amount of organic solvent β contained in the sublimation ink during the preparation of the transfer medium in the sublimation ink coating process.

[0501] The peeling section (902) is located on the downstream side of the transfer section (901).

[0502] The peeling section (902) peels off the used transfer paper substrate (P′3) after the transfer process has been performed in the transfer section (901).

[0503] The transfer media recovery unit (805) is located downstream of the stripping unit (902).

[0504] Then, the used transfer paper substrate (P′3) peeled off from the laminate in the peeling section (902) is wound up and recycled.

[0505] It should be noted that, Figure 6The image recording system (900) shown can be configured as a continuous system as follows: a cloth (C′) is fed out and a pretreatment liquid is applied, while a transfer paper substrate (P′) is fed out to form an image for transfer. After the transfer paper (P′2) is dried by the ink drying unit (804), the cloth (C′2) with excess pretreatment liquid removed is overlapped with the transfer paper (P′2) to form a laminate. Then, the image for transfer is transferred onto the cloth (C′2) by the transfer unit (901), and the transfer paper (P′2) is peeled off from the cloth (C′2). However, it can also be a batch system in which the laminate formed by overlapping the transfer paper (P′2) with the cloth (C′2) is pressed from top to bottom.

[0506] Example

[0507] The present invention is described below with examples, but the present invention is not limited thereto. Furthermore, in the examples, the terms "parts" or "%" are used, but unless otherwise specified, they represent "parts by mass" or "% by mass".

[0508] Furthermore, in the following embodiments, unless otherwise specified, the operation is performed at room temperature (25°C).

[0509] Example [1]

[0510] [Preparation of Pretreatment Solution 1]

[0511] Mix the following ingredients to prepare pretreatment solution 1.

[0512] Dimethyl sulfoxide (I / O value: 1.75) 10 parts by weight

[0513] 90 parts by weight of ion-exchanged water

[0514] It should be noted that the I / O value of dimethyl sulfoxide is calculated using the method described above.

[0515] [Preparation of pretreatment solutions 2-5, 7 and 8]

[0516] Except for changing to the organic compounds listed in Table I, pretreatment solutions 2-5, 7 and 8 are prepared in the same manner as pretreatment solution 1.

[0517] The I / O value of organic compounds is calculated using the method described above.

[0518] [Preparation of Pretreatment Solution 6]

[0519] Mix the following ingredients to prepare pretreatment solution 6.

[0520] Dimethyl sulfoxide (I / O value: 1.75) 80 parts by weight

[0521] Colorant capturing compound 1 10 parts by weight

[0522] 10 parts by weight of ion-exchanged water

[0523] It should be noted that the colorant capturing compound 1 uses the compound shown in the following general formula (2).

[0524] Furthermore, the Rf value obtained by paper chromatography is less than 1. The sublimation pigment used to determine the Rf value is CIDisperseRed60.

[0525] [Chemical Formula 4]

[0526]

[0527] Table I shows the composition of each pretreatment solution. It should be noted that all values ​​in Table I represent content, in parts by mass. Furthermore, "-" indicates that the solution does not contain any of these components.

[0528]

[0529] Image Formation

[0530] (1) Pretreatment liquid application process

[0531] Using an inkjet printer equipped with an inkjet printhead (Konica Minolta KM1024iMAE), the pretreatment solutions were applied to the fabrics listed in Table II at a main scan resolution of 540 dpi × sub-scan resolution of 720 dpi. The application area was 200 mm × 200 mm, and the application amount was 40 g / m². 2 .

[0532] It should be noted that the details of the types of fabrics used are as follows.

[0533] Cotton Broad: a wide-width cotton fabric.

[0534] Rayon: A regenerated fiber made by dissolving natural fibers containing cellulose, such as wood and cotton, through a chemical reaction and then spinning them again.

[0535] T / C Broad: A wide-width fabric made from a blend of TETORON (registered trademark) and cotton. It should be noted that TETORON (registered trademark) is a type of polyester fiber.

[0536] Silk Satin: A satin-textured fabric made of silk.

[0537] Nylon Taffeta: A taffeta fabric made of nylon.

[0538] Polyester double crepe: a double crepe fabric made of polyester fiber.

[0539] (2) Pretreatment liquid drying process

[0540] The fabric pretreated with the solution was dried at 130°C for 1 minute using the method described in Table II.

[0541] It should be noted that, regarding the drying methods recorded in Table II, "non-contact" refers to drying carried out by a non-contact dryer, while "contact" refers to drying carried out by a plate-type hot press.

[0542] (3) Transfer process

[0543] After the pretreatment liquid drying process, the fabric is overlapped with roller transfer paper pre-treated with black sublimation ink, with the fabric and black sublimation ink in contact. A transfer device is then used to press the paper at 180°C with a pressure of 300 g / cm². 2 Heat and pressurize for 3 minutes. This causes the sublimation ink on the transfer paper to be sublimated and transferred to the fabric, forming a 200mm x 200mm solid image (flat type) or a 120cm wide solid image (continuous type) on the fabric.

[0544] It should be noted that, regarding the conveying methods recorded in Table II, "flat plate type" refers to transfer performed by a flat plate type sublimation transfer press, and "continuous type" refers to transfer performed by a continuous sublimation transfer press with heated rollers.

[0545] [evaluate]

[0546] (1) Staining concentration

[0547] For the color density (dyeing concentration) in the solid images formed on each fabric, the reflectance R of each fabric at 600nm was measured using a spectrophotometer "CM-25d" (manufactured by Konica Minolta Co., Ltd.) under the conditions of D65 light source, 2° viewing angle, and state I. λ Perform colorimetric analysis and calculate the K / S value.

[0548] It should be noted that the K / S value is an index of surface color density defined by the following formula. The larger the K / S value, the higher the color density; the smaller the K / S value, the lower the color density.

[0549] (Formula) K / S=(1-R λ ) 2 / 2R λ (Kubelka-Munk style)

[0550] (K: light absorption coefficient, S: light scattering coefficient, R) λ Surface reflectivity

[0551] The K / S value is calculated at 5 points within a 200mm × 200mm solid image formed on each piece of fabric. It should be noted that the 5 points within the solid image are as follows.

[0552] (Flat panel: 200mm x 200mm solid image)

[0553] The solid image contains five points: the intersection of the diagonals (the center point), and the midpoints of each of the four corners relative to the center point.

[0554] (Continuous type: case of a solid image 120cm wide)

[0555] The solid image has five points in its width direction, located at distances of 20cm, 40cm, 60cm, 80cm, and 100cm from the end.

[0556] The arithmetic mean of each K / S value is evaluated according to the following criteria, with 3 or above considered acceptable.

[0557] 5: K / S value is greater than 17.

[0558] 4: K / S value greater than 12 and less than 17.

[0559] 3: K / S value greater than 7 and less than 12.

[0560] 2: K / S value greater than 5 and less than 7.

[0561] 1: K / S value is below 5.

[0562] (2) Uneven staining

[0563] For uneven dyeing formed in the solid images of each fabric, the following criteria shall be used for evaluation, with 3 or above considered acceptable.

[0564] 5: The uneven staining is not visible to the naked eye and there are no practical problems.

[0565] 4: The uneven staining is almost invisible to the naked eye, so there are no practical problems.

[0566] 3: Slight uneven staining can be observed with the naked eye, but it does not pose a problem in practical use.

[0567] 2: Uneven staining was observed by the naked eye, making it unsuitable for practical use.

[0568] 1. Visual inspection revealed obvious uneven staining, making it unsuitable for practical use.

[0569] The evaluation results are shown in Table II below.

[0570] Furthermore, "-" indicates that such a situation does not exist. Specifically, it indicates that no pretreatment solution was applied and dried in Comparative Example 1, and no pretreatment solution was dried in Comparative Example 2.

[0571]

[0572] As can be seen from Examples 1-14 and Comparative Examples 1-3, by using the image forming method of the present invention, that is, by applying a pretreatment liquid to the fabric, drying the fabric in a non-contact manner, and forming an image by sublimation transfer, the dyeing concentration is increased and the dyeing unevenness is reduced.

[0573] As can be seen from Examples 1-5, by keeping the content of organic compound (dimethyl sulfoxide) relative to the total mass of the pretreatment solution in the range of 35-100% by mass, especially in the range of 50-100% by mass, the staining concentration is further increased and the staining unevenness is further reduced.

[0574] As can be seen from Examples 4 and 6, the dyeing concentration is further increased by the presence of colorant-capturing compounds in the pretreatment solution.

[0575] As can be seen from Examples 6 to 11, by including natural fibers or cellulose in the fabric, the dyeing concentration is further increased and the uneven dyeing is further reduced.

[0576] As can be seen from Examples 6 and 12, by transferring the dyeing onto the fabric using a continuous sublimation transfer press, uneven dyeing is further reduced.

[0577] As can be seen from Examples 6, 13 and 14, by making the I / O value of the organic compound contained in the pretreatment solution range from 1.00 to 3.00, the staining concentration is further increased. In particular, by making the organic compound contained in the pretreatment solution dimethyl sulfoxide, the staining concentration is further increased and the staining unevenness is further reduced.

[0578] Example [2]

[0579] [1. Preparation of pretreatment solution]

[0580] Pretreatment solutions No. 1 to 3 were prepared by mixing solvent (the organic solvent contained in the pretreatment solution is designated as "organic solvent α"), aromatic heterocyclic compound, surfactant and ion-exchanged water in such a manner as shown in Table III below.

[0581] The compound used as an aromatic heterocyclic compound is the illustrated compound (8).

[0582] It should be noted that in Table III, "N or S" represents nitrogen or sulfur, "○" indicates the presence of nitrogen or sulfur, and "×" indicates the absence of nitrogen or sulfur.

[0583]

[0584] [2. Preparation of Sublimation Ink]

[0585] [2.1] Preparation of dispersion

[0586] Disperbyk-190 (manufactured by BYK-CHEMIE JAPAN Co., Ltd., acid value 10 mg KOH / g) as a dispersant was stirred and mixed with deionized water until homogeneous. Then, Disperse Red 60 as a sublimation dye was added and premixed to disperse the dye within the range of 150~200 nm as determined by dynamic light scattering, thus preparing a dispersion with a sublimation dye concentration of 20% by mass.

[0587] At this point, the amounts of dispersant, ion-exchanged water, and sublimated dye are adjusted so that the content of sublimated dye is 20% by mass relative to the total mass of dispersant, and the amount of solid component of dispersant is 30% relative to the total mass of dispersed dye.

[0588] It should be noted that the Z-average particle size determination based on dynamic light scattering was performed in a sand grinder filled with 0.5 mm zirconium oxide beads at a volume fraction of 50%, using a ZETASIZER 1000 manufactured by MALVERN (“ZETASIZER” is a registered trademark of the company).

[0589] [2.2] Preparation of sublimation ink

[0590] Add appropriate amounts of the obtained dispersion (30% by mass), glycerol (10% by mass) as solvent (the organic solvent contained in the sublimation ink is defined as "organic solvent β"), ethylene glycol (25% by mass), PROXEL GXL as preservative, and sodium citrate hydrate as pH adjuster. Mix with ion-exchanged water to a total of 100% by mass, and filter with a 1μm mesh filter to obtain ink [1] (magenta sublimation ink).

[0591] [3. Image Formation (Example)]

[0592] [3.1] Preparation of image forming material [1]: Example 1

[0593] [3.1.1] The process of applying a pretreatment solution to the fabric (pretreatment solution application process)

[0594] As a fabric, use 40 wide cotton fabric (100% cotton).

[0595] Then, the prepared pretreatment liquid, numbered 1, is applied to the fabric by a rolling process.

[0596] Specifically, after the fabric is immersed in a bath filled with the prepared pretreatment liquid No. 1, the excess pretreatment liquid is squeezed out with a squeezing roller at a pickup rate (the amount of pretreatment liquid applied relative to the weight of the fabric) of 80%.

[0597] In addition, the temperature inside the bath should be maintained at 20~25℃.

[0598] Immediately after the completion of the pretreatment process, the amount of organic solvent α applied is 15% of the total mass of the fabric.

[0599] [3.1.2] The process of drying the fabric

[0600] The fabric with the pretreatment liquid number 1 was placed in the constant temperature dryer (non-contact dryer) used in Example [1] for a certain period of time, and the excess pretreatment liquid was removed by warm air, thereby preparing the pretreated fabric [1].

[0601] The drying conditions were 200°C and 40 seconds, and the remaining amount of organic solvent α after drying was 3% by mass.

[0602] [3.1.3] The process of applying sublimation ink to the transfer medium

[0603] Next, as an image forming apparatus, an inkjet printer equipped with an inkjet printhead (Konica Minolta printhead KM1024iMAE) is prepared.

[0604] Then, the prepared ink [1] is ejected from the nozzle of the inkjet printhead to form a solid image on the adhesive (paste-coated) A4 sublimation transfer paper (SYSTEM GRAPHICS) used as transfer paper.

[0605] Specifically, a main scan at 540 dpi and a secondary scan at 720 dpi were used to create an image (200 mm × 200 mm in size) containing fine lines, grayscale, and solid areas. dpi represents the number of ink droplets (dots) per inch, or 2.54 cm. The ejection frequency was set to 22.4 kHz. The ink-coated transfer paper was then dried in a dryer at 50–80°C for 30 seconds.

[0606] It should be noted that at this time, the total remaining amount of organic solvent β contained in the sublimation ink (ink[1]) coated on the transfer paper (the total remaining amount of glycerol and ethylene glycol) is 5 by mass.

[0607] [3.1.4] The process of transferring sublimation ink from the transfer medium to the fabric (sublimation ink transfer process)

[0608] Next, a transfer device (hot press) is used with a transfer temperature of 180°C, a transfer time of 180 seconds, and a pressing pressure of 300 g / cm³. 2 The fabric with the pretreatment liquid number 1 is heat-pressed to transfer the ink [1] on the transfer paper to the pretreatment fabric [1] to obtain an image formation [1].

[0609] It should be noted that the remaining amount of organic solvent α before transferring the ink [1] onto the transfer paper from the pretreated fabric [1] is the remaining amount of organic solvent α after drying in the process of drying the fabric.

[0610] The remaining amount of the organic solvent α is 3% of the total mass of the pretreated fabric [1].

[0611] [3.2] Preparation of image formations [2]~

[12] : Examples 2~12

[0612] The types of fabric, types of pretreatment liquid, application method, amount of organic solvent α applied immediately after the application of pretreatment liquid, drying temperature, drying time, remaining amount of organic solvent α after drying, and transfer temperature and transfer time in the sublimation ink transfer process are changed to the conditions shown in Table IV below. Otherwise, image formations [2] to

[12] are prepared in the same manner as image formations [1].

[0613] [4. Evaluation]

[0614] [4.1] Staining properties (staining concentration)

[0615] (Evaluation Method)

[0616] Using image forming materials [1]~

[12] , the portion of the ink transferred was measured by a spectrophotometer (manufactured by Konica Minolta Corporation), the K / S value was calculated by the following formula, and the dyeability was evaluated according to the following evaluation criteria.

[0617] The evaluation results are shown in Table IV.

[0618] Of the following evaluation criteria, A, B, C, and D are practically sound.

[0619] It should be noted that the K / S value is an index of surface color density defined by the following formula. The larger the K / S value, the higher the color density, and the smaller the K / S value, the lower the color density.

[0620] Kubelka-Munk formula: K / S = (1-R) 2 / 2S

[0621] (K: light absorption coefficient, S: light scattering coefficient, R: surface reflectivity)

[0622] (Evaluation Criteria)

[0623] A: The K / S value is 15 or higher.

[0624] B: K / S value is 12 or higher and less than 15.

[0625] C: K / S value is 10 or higher and less than 12.

[0626] D: K / S value is 8 or higher and less than 10.

[0627] E: K / S value is less than 8.

[0628] [4.2] Degree of yellowing inhibition

[0629] (Evaluation Method)

[0630] The L color of the untreated fabric was pre-measured using a spectrophotometer (Konica Minolta CM-25d, measuring light source: D65). * a * b * L in color space * value, a * value and b * value.

[0631] In addition, using image forming materials [1]~

[12] , the L of the white background area (the area only treated with pretreatment liquid and not transferred with sublimation ink) was measured. * a * b * L in color space * value, a * value and b * value.

[0632] L of the untreated fabric in advance * value, a * value and b * The value of L in the image formation [1]~

[12] * value, a * value and b * Let the difference of values ​​be ΔL * Value, Δa * Value and Δb * The value is obtained by calculating the color difference ΔE using the following formula. * The ab value is used to evaluate the degree of yellowing inhibition according to the following evaluation criteria.

[0633] The evaluation results are shown in Table IV.

[0634] In the following evaluation criteria, A, B, and C are practically sound.

[0635] (Equation)ΔE * ab={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2

[0636] (Evaluation Criteria)

[0637] A: ΔE * The ab value is less than 1.

[0638] B: ΔE * The ab value is 1 or higher and less than 2.

[0639] C: ΔE * The ab value is 2 or higher and less than 3.

[0640] D: ΔE * The ab value is 3 or higher and less than 4.

[0641] E: ΔE * The ab value is 4 or higher and less than 5.

[0642] F: ΔE * The ab value is 5 or higher.

[0643] [4.3] Degree of discoloration under high humidity conditions

[0644] (Evaluation Method)

[0645] Using image forming materials [1]~

[12] , the L of the portion transferred with sublimation ink was measured by a spectrophotometer (CM-25d, Konica Minolta, light source: D65). * a * b * L in color space * value, a * value and b * The value was then determined again after the image formations [1]~

[12] were placed in an environment of 20℃·95%RH for 7 days. * value, a * value and b * value.

[0646] The L measured 7 days prior to placement, as described above * value, a * value and b * Value and L after 7 days of placement * value, a* value and b * Let the difference of values ​​be ΔL * Value, Δa * Value and Δb * The color difference ΔE before and after placement is calculated using the following formula. * The ab value is used to evaluate the degree of discoloration under high humidity conditions according to the following evaluation criteria.

[0647] The evaluation results are shown in Table IV.

[0648] Of the following evaluation criteria, A, B, C, and D are practically sound.

[0649] (Equation)ΔE * ab={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2

[0650] (Evaluation Criteria)

[0651] A: ΔE * The ab value is less than 1.

[0652] B: ΔE * The ab value is 1 or higher and less than 2.

[0653] C: ΔE * The ab value is 2 or higher and less than 3.

[0654] D: ΔE * The ab value is 3 or higher and less than 4.

[0655] E: ΔE * The ab value is 4 or higher and less than 5.

[0656] F: ΔE * The ab value is 5 or higher.

[0657]

[0658] [5. Summary]

[0659] As shown in Table IV, by applying the organic solvent contained in the pretreatment solution to the fabric under specific conditions, the fabric exhibits excellent overall performance in terms of dyeability, the degree of yellowing inhibition on the white base, and the degree of discoloration under high humidity conditions.

[0660] Symbol Explanation

[0661] 10. Pretreatment liquid drying section

[0662] 11. Attraction Section

[0663] 11a Suction port

[0664] 12 Drying Chamber

[0665] 13 Heat source

[0666] 14. Blower

[0667] 101. Cloth and Silk Delivery Department

[0668] 102 Fabric Conveying Department

[0669] 103 Pretreatment Liquid Supply Section

[0670] 104 Pretreatment Liquid Drying Section

[0671] 105 Fabric Recycling Department

[0672] 201 Transfer Media Delivery Section

[0673] 202 Transfer Media Delivery Unit

[0674] 203 Inkjet Recording Department

[0675] 204 Ink Drying Section

[0676] 205 Transfer Media Recovery Department

[0677] 301 Transfer Printing Department

[0678] 301a heating roller

[0679] 301b Pressure Roller

[0680] 301c heating roller

[0681] 302 Stripping Section

[0682] 400 Image forming apparatus

[0683] 501 Inkjet Recording Department

[0684] 502 Ink Heating Section

[0685] 600 Image forming apparatus

[0686] C. Cloth

[0687] C1 imparts a pretreatment solution to the fabric.

[0688] C2 imparts an appropriate amount of pretreatment solution to the fabric.

[0689] N is a piece of fabric with an image.

[0690] P Transfer Media

[0691] P1 is a transfer medium infused with sublimation ink.

[0692] P2 is a transfer medium that forms the image for transfer.

[0693] P3 Transfer media after heating and pressurization

[0694] 700 Pretreatment Liquid Dispensing Device

[0695] 701 Cloth Delivery Department

[0696] 702 Conveying Department

[0697] 703 Pretreatment Liquid Supply Section

[0698] 704 Pretreatment Liquid Drying Section

[0699] 705 Fabric Recycling Department

[0700] 706 Control Department

[0701] 707 CPU

[0702] 708 RAM

[0703] 709 ROM

[0704] 800 Sublimation Ink Coating Unit

[0705] 801 Transfer Media Delivery Unit

[0706] 802 Conveying Department

[0707] 803 Inkjet Recording Department

[0708] 804 Ink Drying Section

[0709] 805 Transfer Media Recovery Department

[0710] 900 Image Forming System

[0711] 901 Transfer Printing Department

[0712] 901a heating roller

[0713] 901b Pressure Roller

[0714] 902 Stripping Section

[0715] C′ Cloth

[0716] C′1 imparts the pretreatment solution to the fabric.

[0717] C′2 Fabric with excess pretreatment solution removed

[0718] P′ Transfer paper substrate

[0719] P′1 Transfer paper (the paper used for transferring images after they have been formed)

[0720] P′2 is a transfer paper that has been dried in the ink drying section.

[0721] P′3 Used transfer paper substrate

[0722] N′ Fabric with heat-transfer printed images for transfer.

Claims

1. An image forming method, which is an image forming method for forming an image on fabric by sublimating pigment, wherein, The image forming method comprises, in sequence: The process of applying a pretreatment solution to the fabric, The process of drying the fabric, and The process of applying the sublimation dye to the fabric. The pretreatment solution contains organic compounds. The process of applying the sublimation pigment includes: transferring a transfer image formed by applying ink containing the sublimation pigment to a transfer medium onto the fabric. During the drying process, the heat source does not come into contact with the fabric. The pretreatment solution contains an organic solvent containing nitrogen or sulfur as a solvent. The amount of the organic solvent applied immediately after applying the pretreatment solution, relative to the total mass of the fabric, is in the range of 10-150% by mass. In the transfer printing process, the remaining amount of the organic solvent before transferring the ink containing the sublimation pigment to the fabric is in the range of 3 to 40% by mass relative to the total mass of the fabric.

2. The image forming method according to claim 1, wherein, In the drying process, warm air is circulated to dry the fabric.

3. The image forming method according to claim 2, wherein, In the transfer process, a heated roller is used to transfer the transfer image formed on the transfer medium to the fabric.

4. The image forming method according to claim 1 or 2, wherein, The fabric contains natural fibers.

5. The image forming method according to claim 1 or 2, wherein, The fabric contains cellulose.

6. The image forming method according to claim 1 or 2, wherein, The content of the organic compound is in the range of 35% to 100% by mass relative to the total mass of the pretreatment liquid.

7. The image forming method according to claim 6, wherein, The content of the organic compound is in the range of 50% to 100% by mass relative to the total mass of the pretreatment liquid.

8. The image forming method according to claim 1 or 2, wherein, The organic compounds include organic compounds whose inorganic value to organic value ratio is in the range of 1.00 to 3.

00.

9. The image forming method according to claim 8, wherein, The organic compound contains dimethyl sulfoxide.

10. The image forming method according to claim 1 or 2, wherein, The pretreatment solution also contains a colorant-capturing compound.

11. The image forming method according to claim 1, wherein, The temperature during the drying process of the fabric is lower than the boiling point of the organic solvent.

12. The image forming method according to claim 11, wherein, The temperature at which the fabric is dried is lower than the heating temperature during the transfer printing.

13. The image forming method according to claim 12, wherein, The pretreatment solution contains aromatic heterocyclic compounds.

14. The image forming method according to claim 12, wherein, The pretreatment solution is applied via inkjet printing.

15. An image forming apparatus that forms an image on a fabric by sublimating a pigment, wherein... The image forming apparatus has: Mechanism for applying pretreatment liquid to the fabric The mechanism for drying the fabric, and A mechanism for applying the sublimation dye to the fabric. The mechanism for applying the sublimated pigment includes a mechanism for transferring a transfer image formed by applying ink containing the sublimated pigment to a transfer medium to the fabric. In the drying mechanism, the heat source does not come into contact with the fabric. The pretreatment solution contains an organic solvent containing nitrogen or sulfur as a solvent. The amount of the organic solvent applied immediately after applying the pretreatment solution, relative to the total mass of the fabric, is in the range of 10-150% by mass. In the transfer printing process, the remaining amount of the organic solvent before transferring the ink containing the sublimation pigment to the fabric is in the range of 3 to 40% by mass relative to the total mass of the fabric.

16. The image forming apparatus according to claim 15, wherein, In the drying mechanism, warm air is circulated to dry the fabric.

17. An image forming system for dyeing fabric containing natural fibers via sublimation transfer, wherein, The image forming system has: Mechanism for applying pretreatment liquid to the fabric Mechanism for drying the fabric The mechanism for applying sublimation ink to the transfer medium, and A mechanism for transferring the sublimation ink from the transfer medium to the fabric. The mechanism for transferring sublimation ink includes a mechanism for transferring a transfer image formed by applying the sublimation ink to a transfer medium onto the fabric. In the mechanism for drying the fabric, the heat source does not come into contact with the fabric. The pretreatment solution contains an organic solvent containing nitrogen or sulfur as a solvent. Immediately after applying the pretreatment solution, the amount of the organic solvent applied is in the range of 10-150% by mass relative to the total mass of the fabric. In the transfer printing mechanism, the remaining amount of the organic solvent before transferring the sublimation ink to the fabric is in the range of 3 to 40% by mass relative to the total mass of the fabric.

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