Method for manufacturing an intermediate transfer medium for sublimation transfer and method for recording using sublimation transfer.

Abstract

To provide a manufacturing method of an intermediate transfer medium for sublimation transfer and a sublimation transfer recording method, capable of preventing an occurrence of a ghost even if an image recording is performed through repeatedly using a base material.SOLUTION: A sublimation transfer recording method includes: a step of applying a curable ink; a step of forming a porous layer; a step of applying an ink for sublimation transfer; and a step of forming an image on a recording medium. The porous layer is formed through irradiating the curable ink with an active energy ray in a state where a content of a solvent in the curable ink is 70 mass% or more. A melting point of the porous layer is 100°C or higher.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an intermediate transfer medium for sublimation transfer and a sublimation transfer recording method.

Background Art

[0002] In image formation on clothing such as polyester, a sublimation transfer recording method using a sublimable dye and transfer paper is known. In this sublimation transfer recording method, an image is formed on the transfer paper using an inkjet recording method, and the sublimable dye on the transfer paper is sublimation-transferred to the clothing by heat-pressing the clothing and the transfer paper together. The transfer paper on which this sublimable dye is recorded is difficult to reuse after use because of the problem of bleeding during recycling of waste paper, and there is a demand for a transfer system that can be repeatedly used without generating paper waste from the viewpoints of cost and environmental load.

[0003] Patent Document 1 discloses a method of forming a dye-dyeable resin layer on a heat-resistant polymer film substrate and erasing an image formed by sublimable ink on the resin layer by heating to the sublimation start temperature.

Prior Art Documents

[0007] The above problems are solved by the present invention as described below. In other words, the present invention is A step of applying a curable ink containing a polymerizable compound and a solvent to a substrate, A step of curing the polymerizable compound by irradiating the curable ink applied to the substrate with active energy rays to form a porous layer, A step of removing the solvent present in the pores of the porous layer by drying, A step of applying a sublimation transfer ink containing a sublimation dye to the porous layer from which the solvent has been removed, A step of recording an image on a recording medium by heating an intermediate transfer medium for sublimation transfer, which has the porous layer to which the sublimation transfer ink is applied and the substrate, while facing a recording medium, thereby sublimating the sublimable dye. A step of removing the porous layer from the substrate after the sublimation of the sublimable dye, Sublimation transfer record It is a method, In the step of forming the porous layer, the porous layer is formed by irradiating the curable ink with the active energy ray while the solvent content in the curable ink is 70% by mass or more based on the total mass of the curable ink. Sublimation transfer characterized by the porous layer having a melting point of 100°C or higher. record Regarding the method. [Effects of the Invention]

[0009] As described above, the present invention provides a method for manufacturing an intermediate transfer medium for sublimation transfer and a sublimation transfer recording method that can suppress the occurrence of ghosting even when the substrate is used repeatedly for image recording. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing an example of the configuration of an intermediate transfer medium for sublimation transfer. [Figure 2] This is a schematic diagram showing an example of the configuration of an inkjet recording device. [Figure 3] This flowchart shows an example of the sequence of steps for the sublimation transfer recording method of the present invention. [Figure 4] This is a schematic diagram showing an example of the apparatus configuration for the sublimation transfer recording method of the present invention. [Modes for carrying out the invention]

[0011] One embodiment of the present invention is a method for manufacturing an intermediate transfer medium for sublimation transfer, comprising the steps of: applying a curable ink containing a polymerizable compound and a solvent to a substrate; and curing the polymerizable compound by irradiating the curable ink applied to the substrate with active energy rays to form a porous layer, wherein in the step of forming the porous layer, the active energy rays are irradiated onto the curable ink when the solvent content in the curable ink is 70% by mass or more based on the total mass of the curable ink, thereby forming the porous layer, and the melting point of the porous layer is 100°C or higher.

[0012] Another embodiment of the present invention includes a step of applying a curable ink containing a polymerizable compound and a solvent to a substrate, a step of irradiating the curable ink applied to the substrate with active energy rays to cure the polymerizable compound and form a porous layer, a step of applying an ink for sublimation transfer containing a sublimable dye to the porous layer, and a step of heating a sublimation transfer intermediate transfer medium having the porous layer to which the ink for sublimation transfer is applied and the substrate in a state facing a recording medium to sublime the sublimable dye and record an image on the recording medium. In the step of forming the porous layer, the porous layer is formed by irradiating the curable ink with the active energy rays in a state where the content of the solvent in the curable ink is 70% by mass or more based on the total mass of the curable ink, and the melting point of the porous layer is 100°C or higher. This is a sublimation transfer recording method characterized by this.

[0013] In the present invention, first, a curable ink is applied onto a substrate. Then, by irradiating the applied curable ink with active energy rays, a polymerization reaction of the polymerizable compound contained in the curable ink is carried out to form a cured product (a polymer of the polymerizable compound). Here, a porous cured product can be formed by irradiating the curable ink with active energy rays in a state where the content of the solvent in the curable ink is 70% by mass or more based on the total mass of the curable ink. That is, this porous cured product is formed on the substrate as a porous layer. Therefore, by applying an ink for sublimation transfer to a sublimation transfer intermediate transfer medium (hereinafter, also simply referred to as "intermediate transfer medium") having this porous layer and the substrate, the intermediate transfer medium can absorb the ink for sublimation transfer. Although the details of the reason why the porous cured product is formed are unclear, the inventors presume that polymerization solid-liquid separation occurs where the cured product and the solvent are separated during the polymerization of the polymerizable compound, making it easier for the solvent to be removed from the cured product. As a result, the part of the solvent becomes voids, forming the porous cured product.

[0014] Further, the melting point of this porous layer is 100°C or higher. When the melting point of the porous layer is within this range, the shape of the porous layer is less likely to change even by heating when sublimating the sublimable dye from the intermediate transfer medium to which the sublimation transfer ink is applied and recording an image on the recording medium. Therefore, an image can be recorded on the recording medium without hindering the sublimation of the sublimable dye. Regarding the upper limit of the melting point of the porous layer, there is no particular limitation, but from the viewpoint of the removability of the porous layer from the substrate, the melting point of the porous layer is preferably 200°C or lower.

[0015] Furthermore, since the porous layer can be removed from the recording medium, after image recording, the porous layer can be removed from the substrate and a new porous layer can be formed again on the substrate. As a result, the sublimation transfer ink used for recording the first image does not remain on the substrate, and even when image recording is performed by repeatedly using the substrate, the generation of ghosting can be suppressed.

[0016] Hereinafter, the present invention will be described in detail with reference to preferred embodiments. Physical property values are values at normal temperature (25°C) unless otherwise specified.

[0017] First, the intermediate transfer medium for sublimation transfer will be described below. FIG. 1 is a schematic diagram showing an example of the configuration of an intermediate transfer medium for sublimation transfer after the sublimation transfer ink is applied. First, a curable ink is applied on a substrate 101. Then, the applied curable ink is irradiated with active energy rays to cure the polymerizable compound in the curable ink, thereby forming a porous layer 102. An image is recorded by applying a sublimation transfer ink containing a sublimable dye to the intermediate transfer medium for sublimation transfer having this porous layer. At this time, the sublimation transfer ink is absorbed by this porous layer 102, and the sublimable dye 103 is held in the porous layer 102. By heating in a state where this intermediate transfer medium for sublimation transfer is opposed to the recording medium, the sublimable dye 103 is sublimated and an image is recorded on the recording medium.

[0018] <Curable Ink> Curable inks are active energy ray curable inks containing polymerizable compounds (polymerizable compounds) and solvents.

[0019] (polymerizable compound) Polymerizable compounds have polymerizable groups, and the molecular weight of the polymerizable compound is preferably 5,000 or less, more preferably 3,000 or less, and particularly preferably 1,000 or less. By using polymerizable compounds (such as polymerizable monomers and polymerizable oligomers) with a molecular weight within the above range, it is possible to achieve a higher level of both ejection performance from the inkjet head and cured film characteristics. Furthermore, if the main component of the solvent contained in the curable ink is water, it is preferable that the polymerizable compound is water-soluble. This allows the polymerizable compound to dissolve in water within the curable ink, and by irradiating the curable ink with active energy rays in this state, polymerization solid-liquid separation occurs, making it easier to form a porous layer.

[0020] Examples of water-soluble polymerizable compounds include acrylamide compounds such as acrylamide, methacrylamide, diacetone acrylamide, diacetone methacrylamide, hydroxyethyl acrylamide, hydroxyethyl methacrylamide, ethylenebisacrylamide, and ethylenebismethacrylamide; monoacrylic acid ester compounds such as monoacrylic acid esters of oligoethylene oxides and dibasic acids; acryloyl morpholine; and N-vinylpyrrolidone. Among these, it is preferable that the water-soluble polymerizable compound includes an acrylamide compound. Furthermore, in order to improve the absorbency of the sublimation transfer ink for the porous layer, it is preferable that the polymerizable compound includes a polyfunctional acrylamide compound. Examples of commercially available polyfunctional acrylamides include FFM4 (water-soluble bifunctional acrylamide), FFM3 (water-soluble trifunctional acrylamide), and FFM2 (water-soluble tetrafunctional acrylamide) (all manufactured by Fujifilm), under the following trade names. In this specification, "water-soluble" refers to the property of the polymerizable compound dissolving in water at 25°C at a concentration of 1% by mass or more. Furthermore, the content of polymerizable compounds in the curable ink is preferably 5% by mass or more and 25% by mass or less, based on the total mass of the curable ink.

[0021] (Other ingredients) Curable inks may contain components other than the polymerizable compounds mentioned above. Examples of components other than polymerizable compounds include reactive functional compounds such as surfactants, curing accelerators, water-soluble additives, and viscosity modifiers.

[0022] (Polymerization initiator) Polymerizable compounds contained in curable inks may undergo a polymerization reaction directly initiated by active energy rays, or the polymerization reaction of polymerizable compounds can be initiated by incorporating a polymerization initiator into the curable ink and allowing active energy rays to act on the polymerization initiator. As a polymerization initiator, for example, a compound that generates an active species that initiates the curing (polymerization) of a curable substance having a ketone structure through the exchange of light (photopolymerization initiator) can be used. In particular, since the curing reaction of a curable substance having a ketone structure proceeds significantly through the generation of radicals, it is preferable to use a polymerization initiator that generates radicals through the exchange of light.

[0023] The polymerization initiator is preferably a compound having a water-soluble group. Examples of water-soluble groups include hydroxyl groups, carboxylic acid groups, sulfonic acid groups, phosphate groups, carboxylic acid bases, sulfonic acid bases, phosphate bases, ether groups, and amide groups. When the ink contains a colorant having anionic groups, it is preferable to use a polymerization initiator that does not have an ester group in order to suppress hydrolysis. Specific examples of polymerization initiators include compounds represented by the following structural formulas (A) to (C) (polymerization initiators A to C). Polymerization initiator A is an example of an acylphosphine-based active energy ray polymerization initiator. Polymerization initiator B is an example of an α-hydroxyketone-based active energy ray polymerization initiator. Polymerization initiator C is an example of a thioxanthone-based active energy ray polymerization initiator. Polymerization initiator A was used in this example. [ka]

[0024] The content of polymerization initiator in the curable ink is preferably 0.01% to 20% by mass, more preferably 0.01% to 10% by mass, and even more preferably 0.01% to 5% by mass, based on the total mass of the curable ink. By keeping the content of polymerization initiator within the above range, unreacted polymerization initiator is less likely to remain in the porous layer, and the strength of the porous layer can be made appropriate. It is also possible to use polymerization initiators and sensitizers in combination, or to use two or more types of polymerization initiators in combination.

[0025] (solvent) The solvent contained in the curable ink is preferably water. The water content in the curable ink is preferably 30% by mass or more, and more preferably 50% by mass or more, based on the total mass of the curable ink. Furthermore, there is no particular upper limit to the water content in the curable ink as long as the effects of the present invention are obtained, but for example, it can be 95% by mass or less, based on the total mass of the curable ink.

[0026] Furthermore, various organic solvents may be added as solvents to improve various performance aspects without impairing the original properties. For example, certain organic solvents can impart non-volatility to the ink. In addition, various organic solvents can be added to the ink for purposes such as adjusting viscosity, adjusting surface tension, and imparting wettability to recording media.

[0027] Examples of organic solvents include glycol ethers such as ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, and propylene glycol monomethyl ether; and monohydric alcohols such as methanol, ethanol, propanol, butanol, and pentanol.

[0028] Furthermore, to improve image robustness and adhesion, the curable ink may contain a resin. The resin contained in the curable ink may be emulsified and dispersed in a solvent such as water, rather than being completely dissolved. If the curable ink contains a resin, the resin content is preferably 30% by mass or less, based on the total mass of the ink.

[0029] <Base material> The substrate must be resistant to curable inks used to form the porous layer and sublimation transfer inks used to form the image, and it must be able to withstand high temperatures of around 200°C during sublimation transfer. For this reason, polyimide, polyphenylene sulfide, polytetrafluoroethylene, polyamide-imide, and silicone resin are preferred materials for the substrate. The substrate may be in the form of cut paper, or it may be in the form of a roll-to-roll or drum that continuously prints, transfers, and cleans, and is not limited to these forms. From a handling perspective, it is preferable that the substrate has a certain degree of rigidity. If the substrate is too thin and weak, it will wrinkle easily, but if it is too rigid, it will not be able to be fed through a printer that uses a paper feeding mechanism. Therefore, the thickness of the substrate is preferably around 25 μm to 500 μm. However, this is not limited to flatbed printers, etc.

[0030] <Formation of a porous layer> The porous layer is formed by applying a curable ink to a substrate and curing it by irradiation with active energy rays. The porous layer must be formed in the area where the image is formed with a sublimation transfer ink containing at least a sublimable dye.

[0031] While it is preferable to use an inkjet method for applying the curable ink to the substrate, the method is not necessarily limited to this. The method of applying the curable ink can be appropriately selected from various coaters such as slit coaters, bar coaters, and spin coaters, as well as spraying, dipping, and various printing techniques such as relief printing (letterpress), intaglio printing (gravure), lithography (offset), and stencil printing (silkscreen).

[0032] When water is used as the solvent in a curable ink, it is preferable to use an inkjet recording head that ejects ink by the action of thermal energy as the inkjet recording head that dispenses the curable ink, but a piezo-type inkjet recording head may also be used.

[0033] The porous layer formed on the substrate serves as an ink-receiving layer that receives sublimation transfer ink and holds an image containing sublimable dyes. Therefore, its thickness is preferably 0.5 to 50 μm, and more preferably 1.0 to 30 μm.

[0034] The curable ink applied to the substrate is irradiated with active energy rays. Examples of active energy rays include electron beams, ultraviolet (UV), alpha rays, beta rays, gamma rays, and X-rays. Of these, ultraviolet rays are preferred. The required cumulative intensity of ultraviolet light is 300-5,000 mJ / cm² of total ultraviolet energy. 2 It is preferable that the peak irradiance of ultraviolet light be 100 to 3,000 mW / cm². 2 It is preferable that this be the case.

[0035] The irradiation timing of the active energy rays should preferably be carried out as soon as possible after the curable ink is applied to the substrate. Specifically, the active energy rays should be irradiated onto the curable ink when the solvent content in the curable ink is 70% by mass or more, based on the total mass of the curable ink. For example, if the solvent contained in the curable ink applied to the substrate is a volatile solvent, it is necessary to irradiate with active energy rays before 30% by mass of the volatile solvent in the curable ink has evaporated. Also, if the curable ink contains water as a solvent, it is preferable to irradiate the curable ink with active energy rays when the water content in the curable ink is 70% by mass or more, based on the total mass of the curable ink. The solvent content in the curable ink at the time of irradiation with active energy rays can be estimated by applying the curable ink to the substrate in advance and measuring the change in weight of the substrate with the curable ink applied over time using an electronic balance. Furthermore, when the solvent is water, the drying rate of curable ink can be measured using methods other than the gravimetric method. Moisture meters using infrared radiation or microwaves can be used as appropriate. Furthermore, a porous layer is formed by irradiating the curable ink with active energy rays, and the solvent present in the pores of the porous layer can be removed by natural drying or heat drying.

[0036] Furthermore, in order to ensure proper sublimation of the sublimable dye from the porous layer, it is important that the melting point of the porous layer be 100°C or higher. It is also preferable that the melting point of the porous layer be higher than the sublimation temperature of the sublimable dye contained in the sublimation transfer ink. The melting point of the porous layer can be measured by known methods.

[0037] <Recording images onto an intermediate transfer medium> An image is recorded on an intermediate transfer medium by applying sublimation transfer ink to a porous layer formed on a substrate. Known recording devices can be used to record images on the intermediate transfer medium. Specifically, inkjet recording devices, letterpress printing devices, gravure printing devices, offset printing devices, screen printing devices, etc., can be appropriately selected. Among these, inkjet recording devices are preferred. The following describes an inkjet recording device.

[0038] (Inkjet recording device) An inkjet recording device is equipped with a recording head that ejects ink using an inkjet method. There are no particular restrictions on the inkjet method, but a method that ejects ink by applying thermal energy is preferred because it allows for easy implementation of high-density multi-orifice recording heads and enables high-resolution and high-quality image recording at high speed.

[0039] As a recording head that ejects ink by applying thermal energy, it is preferable to adopt the basic principles disclosed in, for example, U.S. Patent No. 4,723,129 and U.S. Patent No. 4,740,796. Such a system is applicable to both so-called on-demand and continuous types. In the case of an on-demand type, it is preferable to apply at least one drive signal that corresponds to the recording information and causes a rapid temperature rise exceeding nucleation boiling to an electrothermal converter positioned in accordance with the sheet or liquid channel in which the ink is held. This generates thermal energy in the electrothermal converter, causing film boiling on the thermal surface of the recording head, and as a result, it is effective in forming bubbles in the ink in a one-to-one correspondence with this drive signal.

[0040] The growth and contraction of bubbles causes ink to be ejected from the nozzle, forming at least one droplet. A pulsed drive signal is preferable because it allows for immediate and appropriate bubble growth and contraction, resulting in particularly responsive ink ejection. Suitable pulsed drive signals include those described in U.S. Patent Nos. 4,463,359 and 4,345,262. Furthermore, it is preferable to adopt the conditions regarding the rate of temperature rise on the thermally acting surface, as described in U.S. Patent No. 4,313,124.

[0041] Suitable recording head configurations include those disclosed in the above-mentioned specifications, which consist of a combination of discharge port, liquid channel, and electrothermal converter (linear or right-angle liquid channel). Other suitable configurations include those disclosed in U.S. Patent No. 4,558,333 and U.S. Patent No. 4,459,600, which involve the thermal working section being located in a bent region. Furthermore, the atmospheric discharge method described in Japanese Patent No. 2962880, Japanese Patent No. 3246949, and Japanese Patent Application Publication No. 11-188870 is also effective. Additionally, configurations where a common discharge port serves as the discharge port for multiple electrothermal converters (e.g., Japanese Patent Application Publication No. 59-123670) are also effective.

[0042] The following can be used as full-line type recording heads having a length corresponding to the maximum width of the recording medium that the inkjet recording device can record on. For example, it may be a configuration that satisfies the length by combining multiple recording heads as disclosed in the above specification, or a configuration as a single recording head formed integrally. Furthermore, replaceable chip-type recording heads that can be attached to the recording device to enable electrical connection with the device body and ink supply from the device body, and cartridge-type recording heads that are integrally provided with the recording head are also effective.

[0043] It is also preferable to add means for recovering the recording head and auxiliary means to the inkjet recording device. Specifically, these include means for capping the recording head, cleaning means, pressurizing or suction means, electrothermal converter, heating element, preheating means, and pre-ejection mode.

[0044] Figure 2 is a schematic diagram showing an example of the configuration of an inkjet recording device. The inkjet recording device 200 shown in Figure 2 is a recording device that employs a multi-pass method using a short serial-type recording head, and records while scanning the recording head 202 in the width direction of the intermediate transfer medium. The carriage, which has an ink tank 201, a recording head 202, and an active energy ray irradiation device 203, is movable along a guide shaft 204. An image is formed on the intermediate transfer medium, which is transported along direction B (back-to-front direction in Figure 2) by the intermediate transfer medium transport roller 205, while moving back and forth in the main scanning direction indicated by arrow A.

[0045] The carriage is equipped with a recording head (not shown) with multiple ink ejection nozzles arranged in parallel, and an ink tank 201 which serves as a container for the ink. An active energy ray irradiation device 203 is provided at least one end of the carriage in the main scanning direction A. Therefore, it is possible to irradiate the recording surface with active energy rays from the active energy ray irradiation device 203 immediately after ink is applied to the recording medium. Examples of active energy rays include electron beams, ultraviolet rays (UV), alpha rays, beta rays, gamma rays, and X-rays.

[0046] The recording head has multiple ink ejection ports formed on the ejection port surface facing the intermediate transfer medium (not shown), arranged in the transport direction of the intermediate transfer medium (sub-scanning direction of B). The recording head 202 is provided with ink paths that communicate with each of the multiple ejection ports. Corresponding to each ink path, an electrothermal converter is provided to generate thermal energy for ejecting the ink.

[0047] The electrothermal converter generates heat when electrical pulses corresponding to the drive data are applied, causing film boiling in the ink and ejecting ink from the nozzle as bubbles are generated. A common liquid chamber is connected to each ink flow path, and this common liquid chamber is connected to the ink tank 201.

[0048] The inkjet recording device 200 shown in Figure 2 is equipped with a linear encoder (not shown) for detecting the movement position of the carriage. Specifically, a linear scale (not shown) provided along the direction of carriage movement has, for example, 1,200 equally spaced slits per inch. On the carriage side, for example, a slit detection system (not shown) having a light-emitting unit and a light-receiving sensor, and a signal processing circuit are provided. Therefore, the linear encoder outputs an ejection timing signal indicating the ink ejection timing, and information on the carriage's movement position, in accordance with the carriage's movement. By ejecting ink each time a slit on the linear scale is detected, an image with a resolution of 1,200 dpi can be recorded in the main scanning direction A.

[0049] The intermediate transfer medium is intermittently transported in a sub-scanning direction B perpendicular to the carriage's operating direction. The recording medium is supported and transported by at least one pair of intermediate transfer medium transport rollers 205. The driving force for the intermediate transfer medium transport rollers 205 is supplied from a recording medium transport motor (not shown).

[0050] In the inkjet recording device 200 shown in Figure 2, an image can be recorded on the entire intermediate transfer medium by moving the carriage and alternately repeating recording in a width corresponding to the arrangement width of the ejection ports of the recording head 202 and feeding the intermediate transfer medium. The carriage stops at the home position as needed at the start of recording or during recording. At this home position, a cap member (not shown) is provided that caps the ejection surface side of each recording head. A suction recovery means (not shown) is connected to this cap member to forcibly absorb ink from the ejection port and prevent clogging of the ejection port.

[0051] In addition to the multi-pass method described above, there is a line method that uses a line head in which recording elements are arranged to cover the entire area of ​​one side of the intermediate transfer medium. In the line method, by scanning the intermediate transfer medium in a direction perpendicular to the direction of the recording element arrangement, image recording can be performed on the entire surface of the intermediate transfer medium. Therefore, a transport system such as a carriage that scans the short head is not required. Furthermore, complex scanning control between the carriage movement and the intermediate transfer medium is not required, and only the intermediate transfer medium moves, so the recording speed can be increased compared to the multi-pass method.

[0052] (Sublimation transfer ink) The sublimation transfer ink is not particularly limited and can be appropriately selected from conventionally known sublimation transfer inks, but it is preferable to use one that has good properties as a sublimable dye, for example, one that has sufficient color density and is not easily discolored by light, heat, temperature, etc., such as diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, indoaniline dyes, acetophenoneazomethine, pyrazoloazomethine, imidazolazomethine, imidazoazomethine, pyridoneazomethine, and other azomethine dyes. Examples include xanthene dyes, oxazine dyes, cyanostyrene dyes such as dicyanostyrene and tricyanostyrene, thiazine dyes, azine dyes, acridine dyes, benzene azo dyes, pyridone azo, thiophene azo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, disazo, and other azo dyes, spiropyran dyes, indolinospiropyran dyes, fluorane dyes, rhodamine lactam dyes, naphthoquinone dyes, anthraquinone dyes, and quinophthalone dyes. More specifically, examples include red dyes such as Disperse Red 60, Disperse Violet 26, Ceres Red 7B, and Samaron Red F3BS; yellow dyes such as Disperse Yellow 231, PTY-52, and Macrolex Yellow 6G; and blue dyes such as Solvent Blue 63, Vacolin Blue AP-FW, Holon Brilliant Blue SR, MS Blue 100, and CI Solvent Blue 22. Furthermore, sublimation dyes only need to be able to sublimate from the intermediate transfer medium to the recording medium by heating. The sublimation temperature of the sublimation dye is preferably between 100°C and 200°C.

[0053] Sublimation Transfer An intermediate transfer medium coated with sublimation transfer ink is heated while facing the recording medium. At this time, the intermediate transfer medium and the recording medium may be in contact. Furthermore, in order to efficiently transfer the sublimation dye to the recording medium, it is preferable to heat and pressurize while the intermediate transfer medium and the recording medium are in contact. A commercially available heat press can be used as appropriate for heating and pressurizing, and is not particularly limited. The heating temperature during sublimation transfer must be higher than the sublimation temperature of the sublimation dye. Specifically, it is preferable to perform sublimation transfer by heat pressing while heated to 170-230°C. For example, it is preferable from the viewpoint of adhesion and heat insulation to stack the heating plate of the heat press, the intermediate transfer medium, the recording medium, and a silicone resin rubber mat in that order. Furthermore, known recording media used in sublimation transfer can be used as the recording medium on which the image is ultimately recorded. Among these, it is preferable that the recording medium contains polyester in order to improve the fixation of the sublimation dye. Furthermore, the heating time during sublimation transfer of the intermediate transfer medium to which the sublimation transfer ink is applied can be the same as the heating time used in general sublimation transfer. If the porous layer has a melting point of 100°C or higher, the sublimable dye will not dissolve easily, and the image quality will not be affected. Specifically, the heating time is preferably between 5 seconds and 120 seconds.

[0054] <Removal of porous layer> It is preferable to remove the porous layer remaining after the sublimation of the sublimable dye from the substrate. A cleaning material is used to remove the porous layer. Examples of cleaning materials include cloths. It is preferable to perform this cleaning with the cloth moistened with water. For example, a nonwoven fabric can be wrapped around a rubber roller, wet with water, and rotated while applying shear force to the intermediate transfer medium to remove the remaining porous layer containing the sublimable dye. The method of removing the porous layer is not limited to this; it can also be peeled off from the transfer film by pressing an adhesive sheet against it, or scraped off from the intermediate transfer medium with a squeegee. Furthermore, ultrasonic cleaning may be performed while immersed in water. These methods may also be combined.

[0055] <Flowchart> Figure 3 is a flowchart illustrating an example of the sequence of steps for preparing an intermediate transfer medium for sublimation transfer and performing sublimation transfer recording. A curable ink is applied to a substrate, and the curable ink is cured by irradiation with energy rays. Then, the solvent is removed by drying, and an intermediate transfer medium having a porous layer is obtained. Next, sublimation transfer ink is applied to the porous layer, dried, and sublimation transfer is performed by heating the intermediate transfer medium in opposition to a recording medium such as polyester using a press or the like. Then, the porous layer containing the remaining sublimation dye on the substrate is removed as described above. By repeating the above steps, the sublimation transfer recording method for image formation of the present invention is provided.

[0056] <Sublimation Transfer Recording Device> Figure 4 is a schematic diagram showing an example of an apparatus used in the sublimation transfer recording method of the present invention. A belt-shaped substrate 401 is conveyed by a transport roller 402. A first inkjet recording head 403 ejects a curable ink onto the substrate 401. Next, the curable ink is cured by irradiating it with active energy rays using an active energy ray irradiation device 404, such as an LED or lamp. This makes possible an intermediate transfer medium on which a porous layer has been formed on the substrate 401. Next, a second inkjet recording head 405 ejects sublimation transfer inks of each color onto the intermediate transfer medium to form a desired image. At this time, a drying device may be installed after ejection by the first and second inkjet recording heads. As the drying device, the substrate may be heated with a heater, or heated with hot air, infrared heating, or ultrasonic drying may be used. At this time, it is preferable that the drying temperature be below the sublimation temperature, as exceeding the sublimation temperature of the sublimable dye will cause sublimation to occur before drying. Next, the recording medium, such as polyester cloth 407, and the intermediate transfer medium are transported by the cloth transport roller 406 and passed through the nip between the cloth transport roller 406 and the heating roller 408. This heats and pressurizes the intermediate transfer medium, thereby performing sublimation transfer onto the polyester cloth. The polyester cloth on which the image has been recorded by sublimation transfer is then wound up. Next, the porous layer containing the sublimable dye remaining on the base material 401 is removed by bringing a cleaning roller 409, on which a moisture-soaked cloth is wound, into contact with the base material 401 at a speed difference. A metal or resin blade may also be used to scrape off the porous layer. The sublimation transfer recording method of this embodiment is carried out by repeating the above steps.

[0057] Furthermore, although the above example shows the use of a line head as the inkjet recording head, a multi-pass configuration with a serial head is also acceptable. In this case, instead of using two recording heads, the nozzles of the recording head can be arranged in a staggered pattern or used in sections to eject the curable ink first, followed by the sublimation transfer ink. [Examples]

[0058] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited in any way by the following examples unless it exceeds the gist of the invention. Unless otherwise specified, amounts of components indicated in "parts" and "%" are based on mass.

[0059] <Manufacturing of curable inks> The curable inks used in this example and comparative example are as follows: In the ingredients listed below, "Acetylenel E100" is the trade name for a nonionic surfactant (ethylene oxide adduct of acetylene glycol) manufactured by Kawaken Fine Chemicals. Also, "FFM3" is the trade name for a curable substance (water-soluble trifunctional acrylamide) manufactured by Fujifilm. "FFM2" is the trade name for a curable substance (water-soluble tetrafunctional acrylamide) manufactured by Fujifilm. · FFM3 6% · FFM2 4% • Polymerization initiator A 3% Acetyleneol E100 1% Triethanolamine 0.5% • Ion-exchanged water 80.5%

[0060] <Formation of a porous layer> An on-demand recording device (product name "Pro-1000," manufactured by Canon Inc.) was prepared, which applies thermal energy corresponding to the recording signal to the curable ink and ejects it. As shown in Figure 2, this recording device was equipped with a UV-LED irradiation device (product name "M30," manufactured by Ushio Inc., 395nm) adjacent to the recording head and used as an inkjet recording device. The integrated irradiation energy of the active energy beam in one unidirectional pass is 500 mJ / cm². 2The following conditions were met for this inkjet recording device. A recording duty cycle of 100% is defined as an image recorded under the conditions of a resolution of 600 dpi x 600 dpi and the application of 4 drops of 3.8 ng of ink to a unit area of ​​1 / 600 inch x 1 / 600 inch. The drive frequency was set to 15 kHz. Using this inkjet recording device, a 3 cm x 10 cm solid image pattern was printed on polyimide film (product name "Kapton 500H", manufactured by Toray DuPont) in a single pass. Pre-applied 300% Duty (Amount applied: 27g / m²) 2 ) and 100% Duty (amount applied: 9g / m²) 2 The drying rate after applying the curable ink in the sample was measured by gravimetric method, and UV light was irradiated at the timing when the target amount of remaining moisture was achieved. In this way, the curable ink containing a polymerizable compound was cured to form a porous layer.

[0061] The melting point of the porous layer was measured using the following method. A 2 mg sample of the porous layer was taken from the prepared porous layer and used as the measurement sample. The melting point of the porous layer was then measured using a differential scanning calorimeter (product name: Discovery DSC 2500, manufactured by TA Instruments). In measuring the melting point, two heating cycles are performed. In the first heating cycle, the temperature is raised from 20°C to 200°C at a heating rate of 10°C / min, the temperature is maintained at 200°C for 5 minutes, and the temperature is cooled from 200°C to 20°C at a cooling rate of 30°C / min, and the temperature is maintained at 20°C for 5 minutes. Subsequently, in the second heating cycle, the temperature is raised from 20°C to 200°C at a heating rate of 10°C / min, the temperature is maintained at 200°C for 5 minutes, and the temperature is cooled from 200°C to 20°C at a cooling rate of 30°C / min. Here, the melting point obtained from the DSC curve obtained during the second heating cycle using a differential scanning calorimeter was defined as the melting point of the porous layer. The melting points of the porous materials produced in each example are shown in Table 1.

[0062] <Application of sublimation transfer ink> On the porous layer of the intermediate transfer medium formed in the solid image pattern described above, sublimation transfer ink was applied using an inkjet recording device (product name "SC-F550", manufactured by EPSON Corporation) to print a 2cm x 2cm solid image pattern for the first time. Furthermore, sublimation transfer ink was applied again to the area where the solid image was printed to print a second solid image pattern. The sublimation transfer ink used was the same as that installed in the inkjet recording device.

[0063] Sublimation Transfer On a hot plate heated to 200°C, an intermediate transfer medium with a porous layer containing sublimable dye formed on the base material, a polyester cloth (product number: 2-07-429-1 White Nomura Tailor), a rubber mat, and a weight were stacked in that order and heated for 30 seconds to perform sublimation transfer. After removing from the hot plate, the intermediate transfer medium and polyester cloth were separated.

[0064] <Removal of the porous layer (cleaning)> The porous layer containing residual sublimable dye from the intermediate transfer medium was wiped away with a damp cloth.

[0065] (Example 1) Amount of curable ink applied when forming a porous layer: 27 g / m² 2 When the moisture content (solvent content in the curable ink) reached 80% by mass, UV irradiation was performed to form a porous layer, and as described above, sublimation transfer ink was applied, sublimation transfer was carried out, and the porous layer was removed.

[0066] (Example 2) Amount of curable ink applied when forming a porous layer: 9g / m 2 Otherwise, the procedure was the same as in Example 1.

[0067] (Comparative Example 1) In the curable ink, the polymerizable compounds FFM3 and FFM2 were replaced with a monofunctional monomer (acryloylmorpholine ACMO 10% by mass), and the intermediate transfer medium was manufactured and sublimation transfer was carried out in the same manner as in Example 1.

[0068] (Comparative Example 2) A porous layer was formed by UV irradiation when the moisture content (solvent content in the curable ink) reached 60% by mass, and the rest of the procedure was the same as in Example 1.

[0069] (Comparative Example 3) The moisture content (solvent content in the curable ink) was set to 30% by mass, and the procedure was otherwise the same as in Example 1.

[0070] (Evaluation of the receptivity of sublimation transfer inks in porous layers) The 2cm x 2cm solid images recorded on the porous layer of the intermediate transfer medium in Examples 1 and 2, and Comparative Examples 1 to 3, were visually observed, and the receptivity of the sublimation transfer ink to the porous layer was evaluated based on the presence or absence of image bleeding. We evaluated the results as follows: A if there was no image bleeding even when printing a solid image with sublimation transfer ink twice; B if no image bleeding occurred when printing a solid image with sublimation transfer ink once, but image bleeding was observed when printing the solid image twice; and C if image bleeding was observed when printing a solid image with sublimation transfer ink once.

[0071] (Ghost evaluation) In Examples 1 and 2, and Comparative Examples 1 to 3, using substrates from which the porous layer had been removed by wiping with a cloth after sublimation transfer, a porous layer containing a sublimable dye was formed on the substrate again in the same manner as in each example and comparative example. Sublimation transfer was then performed on a polyester cloth, and the presence or absence of ghosting in the image formed on the polyester cloth was visually evaluated. Cases where no ghosting occurred were rated as A, and cases where ghosting was observed were rated as C.

[0072] The results are shown in Table 1. [Table 1]

[0073] In Example 1, ink acceptance was not a problem, and even after printing a solid image twice, no bleeding occurred. Sublimation transfer and cleaning could be performed, and no ghosting occurred. In Example 2, the amount of curable ink applied was 9 g / m². 2 As a result, the receptivity of the formed porous layer for sublimation transfer ink was lower than in Example 1. Therefore, there were no problems when printing a solid image with sublimation transfer ink once, but when printing a solid image with sublimation transfer ink twice, some image bleeding occurred.

[0074] In Comparative Example 1, the porous layer deformed during sublimation transfer, resulting in poor cleaning and the occurrence of ghosting. In Comparative Example 2, when a solid image using sublimation transfer ink was printed once, image bleeding occurred on the intermediate transfer medium. This is thought to be because the water content, which is the solvent in the curable ink during UV irradiation, was low, resulting in insufficient porosity in the porous layer. In Comparative Example 3, when a solid image was printed once using sublimation transfer ink, image bleeding occurred on the intermediate transfer medium. It is believed that the water content, which is the solvent in the curable ink during UV irradiation, was even lower than in Comparative Example 2, resulting in insufficient porosity in the porous layer, and that the polymerization of the polymerizable compound progressed, leading to a decrease in cleaning performance.

[0075] This embodiment includes the following methods. (Method 1) A step of applying a curable ink containing a polymerizable compound and a solvent to a substrate, A step of curing the polymerizable compound by irradiating the curable ink applied to the substrate with active energy rays to form a porous layer, A method for manufacturing an intermediate transfer medium for sublimation transfer having, In the step of forming the porous layer, the porous layer is formed by irradiating the curable ink with the active energy ray while the solvent content in the curable ink is 70% by mass or more based on the total mass of the curable ink. A method for producing an intermediate transfer medium for sublimation transfer, characterized in that the porous layer has a melting point of 100°C or higher. (Method 2) A method for producing an intermediate transfer medium for sublimation transfer according to Method 1, wherein the active energy ray is ultraviolet light. (Method 3) The curable ink contains a polymerization initiator, A method for producing an intermediate transfer medium for sublimation transfer according to method 1 or 2, wherein the content of the polymerization initiator in the curable ink is 15% by mass or more based on the content of the polymerizable compound. (Method 4) A step of applying a curable ink containing a polymerizable compound and a solvent to a substrate, A step of curing the polymerizable compound by irradiating the curable ink applied to the substrate with active energy rays to form a porous layer, A step of applying a sublimation transfer ink containing a sublimation dye to the porous layer, A step of recording an image on a recording medium by heating an intermediate transfer medium for sublimation transfer, which has the porous layer to which the sublimation transfer ink is applied and the substrate, while facing a recording medium, thereby sublimating the sublimable dye. A sublimation transfer recording method having, In the step of forming the porous layer, the porous layer is formed by irradiating the curable ink with the active energy ray while the solvent content in the curable ink is 70% by mass or more based on the total mass of the curable ink. A sublimation transfer recording method characterized in that the melting point of the porous layer is 100°C or higher. (Method 5) The sublimation transfer recording method according to method 4, wherein the active energy ray is ultraviolet light. (Method 6) The curable ink contains a polymerization initiator, The sublimation transfer recording method according to method 4 or 5, wherein the content of the polymerization initiator in the curable ink is 15% by mass or more based on the content of the polymerizable compound. (Method 7) A sublimation transfer recording method according to any one of methods 4 to 6, comprising the step of removing the porous layer from the substrate after the sublimable dye has been sublimated.

[0076] The present invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are attached to make the scope of the invention public. [Explanation of Symbols]

[0077] 101 Base material 102 Porous layer 103 Sublimable dyes 200 Inkjet Recording Devices 201 Ink Tank 202 Recording head 203 Active Energy Ray Irradiation Device 204 Guide shaft 205 Intermediate transfer medium transport roller 401 Base material 402 Conveyor Roller 403 First inkjet recording head 404 Active Energy Ray Irradiation Device 405 Second inkjet recording head 406 Fabric conveying roller 407 Polyester fabric 408 Heating roller 409 Cleaning Roller

Claims

1. A step of applying a curable ink containing a polymerizable compound and a solvent to a substrate, A step of curing the polymerizable compound by irradiating the curable ink applied to the substrate with active energy rays to form a porous layer, A step of removing the solvent present in the pores of the porous layer by drying, A step of applying a sublimation transfer ink containing a sublimation dye to the porous layer from which the solvent has been removed, A step of recording an image on a recording medium by heating an intermediate transfer medium for sublimation transfer, which has the porous layer to which the sublimation transfer ink is applied and the substrate, while facing a recording medium, thereby sublimating the sublimable dye. A step of removing the porous layer from the substrate after the sublimation of the sublimable dye, A sublimation transfer recording method having, In the step of forming the porous layer, the porous layer is formed by irradiating the curable ink with the active energy ray while the solvent content in the curable ink is 70% by mass or more based on the total mass of the curable ink. A sublimation transfer recording method characterized in that the melting point of the porous layer is 100°C or higher.

2. The sublimation transfer recording method according to claim 1, wherein the active energy ray is ultraviolet light.

3. The curable ink contains a polymerization initiator, The sublimation transfer recording method according to claim 1, wherein the content of the polymerization initiator in the curable ink is 15% by mass or more, based on the content of the polymerizable compound.

4. The sublimation transfer recording method according to claim 1, wherein the porous layer after the sublimation dye has sublimated is removed from the substrate using a damp cloth.

5. The sublimation transfer recording method according to claim 1, wherein the drying is natural drying or heat drying.

6. The sublimation transfer recording method according to claim 1, wherein the solvent comprises water.

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