Image formation device and image formation method

Abstract

To provide an image formation device of a type that an intermediate image of an intermediate transfer body is transferred to a recording medium, which can clearly transfer the intermediate image even to a recording medium having irregularities on its surface and attain good fixability.SOLUTION: An image formation device includes: an intermediate transfer body 10; first discharging means 11 which discharges a first liquid to the intermediate transfer body; second discharging means 12 which discharges a second liquid to the intermediate transfer body to which the first liquid has been discharged; third discharging means 13 which discharges a third liquid to the intermediate transfer body to which the second liquid has been discharged; fourth discharging means 14 which discharges a fourth liquid to the intermediate transfer body to which the third liquid has been discharged; and transfer means 24, 25 which heat and compress the intermediate transfer body and the recording medium to thermal-transfer an intermediate image on the intermediate transfer body to the recording medium. The first liquid contains a resin (1) and the second liquid is a processing liquid containing a reactant which reacts to the third liquid. The third liquid is an ink containing a color material, water, and a resin (3). The fourth liquid contains water and a resin (4).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus and an image forming method. [Background technology]

[0002] 2. Description of the Related Art Inkjet printers, which are image forming devices, have advantages such as low noise, low running costs, and ease of color printing, and are widely used as output devices for digital signals.

[0003] Widely used inks for such inkjet printers include, for example, solvent-based inks using organic solvents as solvents and ultraviolet-curable inks containing polymerizable monomers as their main components. However, the solvent-based inks raise concerns about the environmental impact of evaporation of the organic solvent. Furthermore, the ultraviolet-curable inks have limited options for polymerizable monomers due to safety concerns.

[0004]

[0003] Therefore, ink sets containing aqueous inks with low environmental impact have been proposed. However, when aqueous inks are printed directly onto plain paper from an ejection device, the ink penetrates into the paper layer, making it difficult to satisfy all of the characteristics required, such as image density, image clarity, image drying, image bleeding, and image show-through. In response to this, a technology has been proposed in which ink is ejected onto an intermediate transfer body, and then the ink held on the intermediate transfer body is transferred to a recording medium to obtain a recorded image.

[0005] Patent Documents 1 and 2 propose that ink ejected from an inkjet head is deposited on an intermediate transfer body, the water content in the ink is evaporated and concentrated by a heating element, and then the intermediate transfer body is pressed against a recording medium, and the ink on the intermediate transfer body is transferred to the recording medium, fixing the recorded image. This is expected to prevent the ink from penetrating into the paper layer, and to solve problems such as image drying, image bleeding, and image show-through. Summary of the Invention [Problem to be solved by the invention]

[0006] However, when fixing a recorded image (intermediate image) on an intermediate transfer member to a recording medium with an uneven surface, there is a risk of voids forming between the recorded image on the intermediate transfer member and the recording medium when the intermediate transfer member and the recording medium are pressed together. If such voids form, the pressure required for transfer cannot be applied, and there is a risk of transfer residue, where the recorded image remains on the intermediate transfer member. If good transferability is not achieved and transfer residue occurs, this can lead to problems such as a decrease in the density of the transferred recorded image and deterioration of the intermediate transfer member. Furthermore, it is necessary to fix the recorded image well to the recording medium, and if good fixability is not achieved, good image density may not be achieved.

[0007] Therefore, the present invention aims to provide an image forming apparatus that can transfer an intermediate image from an intermediate transfer body to a recording medium, and can obtain good fixation properties, even if the recording medium has an uneven surface. [Means for solving the problem]

[0008] In order to solve the above problem, the image forming apparatus of the present invention comprises an intermediate transfer body, a first ejection means for ejecting a first liquid onto the intermediate transfer body, a second ejection means for ejecting a second liquid onto the intermediate transfer body onto which the first liquid has been ejected, a third ejection means for ejecting a third liquid onto the intermediate transfer body onto which the second liquid has been ejected, a fourth ejection means for ejecting a fourth liquid onto the intermediate transfer body onto which the third liquid has been ejected, and a transfer means for applying heat and pressure to the intermediate transfer body and a recording medium, thereby thermally transferring an intermediate image on the intermediate transfer body to the recording medium, wherein the first liquid contains a resin (1), the second liquid is a treatment liquid containing a reactant that reacts with the third liquid, the third liquid is an ink containing a colorant, water, and a resin (3), and the fourth liquid contains water and a resin (4). [Effects of the Invention]

[0009] According to the present invention, an image forming apparatus can be provided that, in a method of transferring an intermediate image from an intermediate transfer body to a recording medium, can transfer the intermediate image well even to a recording medium with an uneven surface, and can obtain good fixability. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus. [Figure 2] 2 is a schematic diagram illustrating temperature T, direction A, etc. in comparison with FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] The image forming apparatus and image forming method according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and other modifications, additions, corrections, deletions, and other changes can be made within the scope of what a person skilled in the art can conceive. Any embodiment that achieves the functions and effects of the present invention is included in the scope of the present invention.

[0012] The image forming apparatus of the present invention comprises an intermediate transfer body, a first ejection means for ejecting a first liquid onto the intermediate transfer body, a second ejection means for ejecting a second liquid onto the intermediate transfer body onto which the first liquid has been ejected, a third ejection means for ejecting a third liquid onto the intermediate transfer body onto which the second liquid has been ejected, a fourth ejection means for ejecting a fourth liquid onto the intermediate transfer body onto which the third liquid has been ejected, and a transfer means for applying heat and pressure to the intermediate transfer body and a recording medium, thereby thermally transferring an intermediate image on the intermediate transfer body to the recording medium, wherein the first liquid contains a resin (1), the second liquid is a treatment liquid containing a reactant that reacts with the third liquid, the third liquid is an ink containing a colorant, water, and a resin (3), and the fourth liquid contains water and a resin (4).

[0013] The image forming method of the present invention includes a first ejection step of ejecting a first liquid onto an intermediate transfer body, a second ejection step of ejecting a second liquid onto the intermediate transfer body onto which the first liquid has been ejected, a third ejection step of ejecting a third liquid onto the intermediate transfer body onto which the second liquid has been ejected, a fourth ejection step of ejecting a fourth liquid onto the intermediate transfer body onto which the third liquid has been ejected, and a transfer step of applying heat and pressure to the intermediate transfer body and a recording medium to thermally transfer an intermediate image on the intermediate transfer body to the recording medium, wherein the first liquid includes a first resin, the second liquid is a treatment liquid including a reactant that reacts with the third liquid, the third liquid is an ink including a colorant, water, and a second resin, and the fourth liquid includes water and a third resin.

[0014] The image forming apparatus may also be referred to as a recording apparatus, a printing apparatus, a medium processing apparatus, etc. Furthermore, since the image forming apparatus of the present invention is equipped with a discharge means for discharging each liquid, it may also be referred to as a liquid discharge apparatus, etc. The recording medium may also be referred to as a medium, a transfer material, a substrate, etc. Furthermore, in the terminology of the present invention, image formation, recording, printing, printing, etc. are all synonymous.

[0015] (Example of overall configuration of image forming apparatus and image forming method) An example of an image forming apparatus according to this embodiment will be described with reference to FIGS. 1 and 2 are diagrams showing an example of the configuration of an image forming apparatus. In FIG. 2, the temperature T, the direction A, etc. are illustrated in comparison with FIG.

[0016] The image forming apparatus 1 includes an intermediate transfer belt 10, a first head 11, a second head 12, third heads 13Y, 13M, 13C, and 13K, a fourth head 14, and a transfer roller 24. The image forming apparatus 1 also includes a rotating roller 15, a cleaning roller 16, a first heating section 21, a second heating section 22, a third heating section 23, an opposing roller 25, and the like.

[0017] The first head 11, the second head 12, the third head 13, and the fourth head 14 may be referred to as a liquid ejection head, a recording head, an inkjet head, a head portion, or the like.

[0018] The intermediate transfer belt 10 is an example of an intermediate transfer body. It may also be called an intermediate transfer substrate. The intermediate transfer belt 10 is supported by a rotating roller 15 or the like. For example, when the rotating roller 15 rotates in a rotation direction A1, the intermediate transfer belt 10 moves in a movement direction A2. The movement of the intermediate transfer belt 10 may also be called rotation, transport, or the like. The intermediate transfer body will be described in more detail below.

[0019] The first head 11 is an example of a first ejection means, and ejects a first liquid onto the intermediate transfer belt 10. The first liquid contains a resin (1). The first liquid may also be referred to as a first liquid, a first ink, or the like. When the first head 11 ejects the first liquid onto the intermediate transfer belt 10, a layer of the first liquid is formed on the intermediate transfer belt 10.

[0020] The first liquid applied to the intermediate transfer belt 10 functions as, but is not limited to, a release layer. By ejecting the first liquid, the intermediate image formed on the intermediate transfer belt 10 is easily transferred to the recording medium 20. If the first liquid is not ejected, good transferability cannot be obtained, and a good image cannot be formed on the recording medium.

[0021] Examples of the resin (1) contained in the first liquid include carnauba wax, lanolin wax, paraffin wax, amide wax, ethylene vinyl acetate copolymer wax, ethylene vinyl acetate / ethylene acrylic acid copolymer wax, polyethylene wax, polypropylene wax, and modified versions of these. From the viewpoint of a release layer, wax is preferred as the first resin contained in the first liquid, and polyethylene wax and polypropylene wax are particularly preferred. In this case, transferability and ejection stability can be improved.

[0022] The melting point of the resin (1) contained in the first liquid is preferably 120° C. or higher, which can improve the transferability and ejection stability.

[0023] The content of the resin (1) in the first liquid can be appropriately selected, and is preferably, for example, 5% by mass or more and 15% by mass or less in the first liquid, which can provide good releasability of the intermediate image and improve ejection stability.

[0024] The first liquid may contain, in addition to the resin (1), for example, water, an organic solvent, a surfactant, and the like.

[0025] In this example, after the first liquid is ejected, the intermediate transfer belt 10 is heated by the first heating unit 21. The heating by the first heating unit 21 may also be referred to as drying. By the heating by the first heating unit 21, a drying process is performed on the layer of the first liquid on the intermediate transfer belt 10.

[0026] The heating temperature of first heating section 21 can be selected as appropriate. In the drawing, the heating temperature of first heating section 21 is indicated by T1. By performing heating with first heating section 21, the organic solvent and water contained in the first liquid can be efficiently evaporated.

[0027] The second head 12 is an example of a second ejection means, and ejects a second liquid onto the intermediate transfer belt 10 onto which the first liquid has been ejected. The second liquid is a treatment liquid containing a reactant that reacts with a third liquid (ink). The second liquid may also be referred to as a treatment liquid, a pretreatment liquid, a second liquid, a second ink, or the like. When the second head 12 ejects the second liquid onto the intermediate transfer belt 10, the second liquid is applied to the layer of the first liquid. If the second liquid is not ejected, good fixability cannot be obtained.

[0028] The components contained in the second liquid can be appropriately selected, and examples thereof include a reactant, water, an organic solvent, a surfactant, and the like. The reactant can be selected appropriately. For example, a reactant that aggregates components having anionic groups, such as resins and pigment dispersions in the ink, can be used. Examples of the reactant include inorganic acid salts, organic acid salts, and cationic polymers. Among these, it is preferable that the second liquid contains a polyvalent metal salt having a valence of two or more. In this case, transferability, image density, and fixability can be improved.

[0029] The third heads 13Y, 13M, 13C, and 13K are examples of third ejection means, and eject a third liquid onto the intermediate transfer belt 10 onto which the second liquid has been ejected. The third liquid is an ink containing a colorant, water, and a resin (3). The third liquid may also be referred to as a third liquid, a third ink, or the like. In the following description, the term "ink" refers to the third liquid unless otherwise specified.

[0030] In this example, four color third heads 13Y, 13M, 13C, and 13K are used as the third ejection means. The third heads 13Y, 13M, 13C, and 13K eject yellow, magenta, cyan, and black ink, respectively. This allows full-color, i.e., four-color, image formation.

[0031] The third ejection means in this embodiment is not limited to this, and may be one color, or the number of heads may be changed. The type of ink ejected by the third ejection means may also be changed as appropriate. In addition to the above, a head corresponding to, for example, white may also be provided. When the third heads 13Y, 13M, 13C, and 13K are not to be distinguished from one another, they may be referred to as third heads 13.

[0032] The third head 13 ejects the third liquid onto the intermediate transfer belt 10, so that the third liquid is applied to, for example, the locations where the first liquid and the second liquid have been applied. The third liquid (ink) reacts with the second liquid (treatment liquid).

[0033] In this example, the second head 12 and the third head 13 are provided adjacent to each other. The second head 12 and the third head 13 may also be provided spaced apart.

[0034] In this example, after the third liquid is ejected, the intermediate transfer belt 10 is heated by the second heating unit 22. The heating by the second heating unit 22 may also be referred to as drying. By the heating by the second heating unit 22, a drying process is performed on the image formed by the first liquid, the second liquid, and the third liquid on the intermediate transfer belt 10.

[0035] The heating temperature of the second heating section 22 can be selected as appropriate. In the figure, the heating temperature of the second heating section 22 is indicated by T2. By performing heating with the second heating section 22, the organic solvent and water contained in the first liquid, etc. can be efficiently evaporated.

[0036] The fourth head 14 is an example of a fourth ejection means, and ejects a fourth liquid onto the intermediate transfer belt 10 onto which the third liquid has been ejected. The fourth liquid includes water and a resin (4). The fourth liquid may also be referred to as a fourth liquid, a fourth ink, or the like. When the fourth head 14 ejects the fourth liquid onto the intermediate transfer belt 10, the fourth liquid is applied to an image formed by the first liquid, the second liquid, and the third liquid.

[0037] The fourth liquid applied to the intermediate transfer belt 10 functions as an adhesive layer, although not limited thereto. By ejecting the fourth liquid, the fourth liquid adheres to the recording medium during thermal transfer, making it easier to transfer the intermediate image formed on the intermediate transfer belt 10 to the recording medium 20. If the fourth liquid is not ejected, good transferability cannot be obtained, and a good image cannot be formed on the recording medium.

[0038] The fourth liquid includes, for example, water, a resin (4), an organic solvent, a surfactant, or the like. The glass transition temperature of the resin (4) contained in the fourth liquid is preferably less than 0° C. In this case, the transferability and image density can be improved.

[0039] In this example, after the fourth liquid is ejected, the intermediate transfer belt 10 is heated by the third heating unit 23. The heating by the third heating unit 23 may also be referred to as drying. By heating by the third heating unit 23, a drying process is performed on the image formed by the first liquid, the second liquid, the third liquid, and the fourth liquid on the intermediate transfer belt 10.

[0040] The heating temperature of the third heating section 23 can be selected as appropriate. In the figure, the heating temperature of the third heating section 23 is indicated by T3. By performing heating with the third heating section 23, the organic solvent and water contained in the first liquid, etc. can be efficiently evaporated. Note that the dashed arrow in the figure schematically indicates the heating direction of the third heating section 23.

[0041] The heating method of the first heating section 21, the second heating section 22, and the third heating section 23 can be selected as appropriate, and examples thereof include a method of heating the intermediate transfer belt 10 from the side where the liquid is ejected (front side), a method of heating from the opposite side to the side where the liquid is ejected (back side), and a combination of these methods. In the illustrated example, the first heating section 21 and the second heating section 22 use a method of heating from the back side, and the third heating section 23 uses a method of heating from the front side.

[0042] The heating method of the first heating section 21, the second heating section 22, and the third heating section 23 is preferably a method (non-contact method) that does not directly contact the intermediate transfer belt 10. Examples of such non-contact drying methods include a hot air heating mechanism using a dryer or the like, a radiation heating mechanism using a halogen heater or an infrared heater, and a heating mechanism using electromagnetic induction.

[0043] As in this example, the image forming apparatus preferably includes a first heating section 21, a second heating section 22, and a third heating section 23. This configuration will be described again. The image forming apparatus of this embodiment preferably includes a first drying means (first heating section 21) that dries the intermediate transfer body after the first ejection means ejects the first liquid and before the second ejection means ejects the second liquid, a second drying means (second heating section 22) that dries the intermediate transfer body after the third ejection means ejects the third liquid and before the fourth ejection means ejects the fourth liquid, and a third drying means (third heating section 23) that dries the intermediate transfer body after the fourth ejection means ejects the fourth liquid. In this way, the quality of the image can be improved.

[0044] The heating temperatures T1 to T3 of the first heating section 21, the second heating section 22, and the third heating section 23 can be selected appropriately. Although not limited thereto, the heating temperatures T1 to T3 of the first heating section 21, the second heating section 22, and the third heating section 23 are preferably, for example, temperatures lower than the melting point of the resin (1) contained in the first liquid. In this case, the first liquid can be solidified on the intermediate transfer body, and the intermediate image can be prevented from being distorted.

[0045] The transfer unit in this embodiment applies heat and pressure to the intermediate transfer body and the recording medium, thermally transferring the intermediate image on the intermediate transfer body to the recording medium. The image formed on the intermediate transfer body (intermediate transfer belt 10) is also referred to as an intermediate image. The image transferred to the recording medium may also be referred to as a transferred image.

[0046] The transfer means in this example has a transfer roller 24 and an opposing roller 25. The transfer roller 24 and the opposing roller 25 form a nip portion, and heating and pressurization are performed as the recording medium 20 transported in the transport direction A3 and the intermediate transfer belt 10 moving in the movement direction A2 pass through the nip portion. In the figure, the heating temperature of the transfer means is indicated by T4.

[0047] In this example, the transfer roller 24 is provided with a heating mechanism. The transfer roller 24 can be configured, for example, by providing a heat source such as a heater lamp inside a support roller. The transfer means in this embodiment is not limited to this example. For example, the transfer roller 24 may not be provided with a heating mechanism, but the opposing roller 25 may be provided with a heating mechanism, or both the transfer roller 24 and the opposing roller 25 may be provided with heating mechanisms.

[0048] As in this example, the transfer means preferably has a heating roller (e.g., transfer roller 24) and a pressure roller (e.g., counter roller 25) facing the heating roller, and thermal transfer is performed by passing the intermediate transfer body and recording medium through the nip formed by the heating roller and pressure roller. This can improve transferability and fixability.

[0049] The cleaning roller 16 is an example of a cleaning unit, and cleans the intermediate transfer belt 10. Examples of the cleaning unit include a roller, a blade, etc. The cleaning unit brings the roller, the blade, etc. into contact with the intermediate transfer belt 10 to clean and remove any remaining intermediate image on the intermediate transfer belt 10.

[0050] As shown in the figure, the cleaning unit is provided downstream of the transfer unit and upstream of the first ejection unit in the direction of movement of the intermediate transfer body. By using the cleaning unit, it is possible to remove the remaining intermediate image, suppress abnormal images, and reduce deterioration of the intermediate transfer body.

[0051] The water, organic solvent, and surfactant contained in the first liquid may be those described in the third liquid (ink) below. The same additives may also be used. The content of these components may also be within the ranges described in the third liquid (ink) below. As described above, the resin (1) contained in the first liquid is preferably wax. The water, resin, organic solvent, and surfactant contained in the second liquid and the fourth liquid may be those described in the third liquid (ink) below. The same additives may also be used. The content of these components may also be within the ranges described in the third liquid (ink) below. On the other hand, it is preferable that the first, second and fourth liquids do not contain a coloring material, since if these liquids do not contain a coloring material, it becomes easier to form an image with a desired color tone.

[0052] In the image forming apparatus and image forming method of this embodiment, an intermediate image from an intermediate transfer member is transferred to a recording medium, and even if the recording medium has an uneven surface, the intermediate image can be transferred satisfactorily, and good fixation can be achieved. When fixation is good, the ejected liquid quickly fixes at the position where it lands, improving image unevenness and image density. Furthermore, according to this embodiment, because of the excellent transferability, high-quality images can be obtained, and good ejection stability can be ensured.

[0053] (Detailed example of intermediate transfer body) A detailed example of the intermediate transfer member in this embodiment will be further described. The intermediate transfer member may have a single layer or multiple layers, for example. In the case of multiple layers, the intermediate transfer member may have a structure including a support and a surface layer on the support.

[0054] The intermediate transfer member preferably contains, for example, a polyimide resin. When the intermediate transfer member is a single layer, it is preferably made of a polyimide resin. When it is a multi-layered intermediate transfer member, it is preferably configured to have a surface layer on a polyimide resin support. When the intermediate transfer member contains a polyimide resin, the image density of the transferred image can be improved.

[0055] The material of the support is not limited to polyimide, and any material having mechanical strength may be used. That is, the material of the support may be resin, metal, alloy, or the like. Specifically, the support may contain aluminum, nickel, nickel alloy, thermosetting resin, ceramic, or the like, in addition to polyimide.

[0056] The surface layer may be made of, for example, silicone rubber. However, the surface layer is not limited to silicone rubber and may be made of any elastic material that has low surface energy and high conformability to the recording medium. Furthermore, the surface layer preferably has high ink releasability.

[0057] The elasticity of the surface layer is preferably within a range that allows the surface layer to deform along the fibers of the recording medium during transfer, and in this range, the elasticity of the surface layer increases the contact area between the surface layer and the recording medium, thereby achieving a high transfer rate.

[0058] Furthermore, when transferring at low pressure, it is desirable that the surface layer be made of a relatively soft material. Alternatively, the surface layer may be a thin coating. Specifically, the surface layer may be made of silicone rubber, fluorosilicone rubber, phenylsilicone rubber, fluororubber, chloroprene rubber, nitrile rubber, nitrile butadiene rubber, isoprene rubber, or the like. The thickness of the surface layer is preferably about 0.1 to 1 mm, and preferably 0.2 to 0.6 mm.

[0059] In an intermediate transfer body such as the intermediate transfer belt 1, the liquid adheres to the intermediate transfer body not by electrostatic force as in the method using toner, but by the adhesive force of the liquid. Therefore, it is preferable that the intermediate transfer body has a property that allows the liquid to easily adhere to the image forming surface of the intermediate transfer body when the liquid is discharged by the discharge means, that is, it has high wettability.

[0060] From this perspective, it is preferable that the contact angle of pure water on the surface of the intermediate transfer body onto which the first liquid is ejected is 60° or less. When the contact angle is 60° or less, the liquid easily adheres to the image forming surface, improving the quality of the intermediate image and the transferred image. The surface of the intermediate transfer body onto which the first liquid is ejected may be referred to as the surface, the image forming surface, etc., and the first to fourth liquids are ejected onto the surface (image forming surface) to form an intermediate image.

[0061] Furthermore, the intermediate transfer body preferably has a property such that after the first to fourth liquids have been ejected and an intermediate image has been formed, the intermediate image is easily transferred from the intermediate transfer body to a recording medium by transfer (thermal transfer) using a transfer means. Thus, the intermediate transfer body preferably has wettability with respect to the ejected liquids and has releasability for the intermediate image. Furthermore, the intermediate transfer body preferably has elasticity to improve transferability.

[0062] Furthermore, the intermediate transfer belt 1 is preferably heat resistant, since it may be heated by the heating unit, heated by the transfer means, and may also be dried by the cleaning means.

[0063] (Recording medium) There are no particular limitations on the recording medium, and although plain paper, glossy paper, special paper, cloth, etc. can be used, good image formation is also possible using an impermeable substrate. The non-permeable substrate is a substrate having a surface with low water permeability and absorbency, and includes materials that have many cavities inside but are not open to the outside. More quantitatively, in the Bristow method, 1 / 2 Water absorption up to 10mL / m 2 The term "substrate" refers to a substrate that is:

[0064] As the impermeable substrate, for example, a plastic film such as a vinyl chloride resin film, a polyethylene terephthalate (PET) film, a polypropylene film, a polyethylene film, or a polycarbonate film can be suitably used.

[0065] The polypropylene and polyethylene are not particularly limited, and examples thereof include AR1025, AR1056, AR1082, EC1082, 1082D, 1073D, 1056D, 1025D, and FR1073 (Asahi DuPont Flash Span). Products Co., Ltd.), P2002, P2102, P2108, P2161, P2171, P2111, P4266, P5767, P3162, P6181, P8121, P1162, P1111, P1128, P1181, P1153, P1157, P1146, P1147, P1171 (Toyobo Co., Ltd.), YPI, AquaYupo, SuperYupo, UltraYupo, NewYupo, Yupo Illumination Paper, Yupo Building Materials Paper, Yupo High Gloss, Yupo Jet, MetallicYupo (Yupo Corporation), etc.

[0066] (ink) The organic solvent, water, coloring material, resin, additives, etc. used in the ink (third liquid) used in the present invention will be described below.

[0067] <Water> The water content in the ink is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of the drying property and ejection reliability of the ink, it is preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass to 60% by mass.

[0068] <Organic solvents> In the present invention, it is preferable to use, for example, alcohols having a boiling point of 250° C. or less under 1 atmosphere. There are no particular limitations on the compounds that can be used in combination, and examples thereof include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds.

[0069] Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, and the like. Polyhydric alcohols such as pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, and petriol, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether. polyhydric alcohol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone; amides such as formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide; amines such as monoethanolamine, diethanolamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate; and ethylene carbonate.

[0070] It is preferable to use glycol ethers with a boiling point of 180°C or less, as they not only function as wetting agents and compatibilizers but also provide good drying properties.

[0071] Polyol compounds having 8 or more carbon atoms and glycol ether compounds are also preferably used. Specific examples of polyol compounds having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. Specific examples of glycol ether compounds include polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; and polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

[0072] Polyol compounds having 8 or more carbon atoms and glycol ether compounds can improve the permeability of ink when paper is used as the recording medium.

[0073] The content of the organic solvent in the ink is not particularly limited and can be selected appropriately depending on the purpose. From the viewpoint of the drying property and ejection reliability of the ink, however, the content is preferably 10% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 60% by mass or less.

[0074] <Colorant> The coloring material is not particularly limited, and pigments and dyes can be used. The pigment may be an inorganic pigment or an organic pigment. These may be used alone or in combination of two or more. Mixed crystals may also be used. Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver pigments, and metallic pigments.

[0075] As inorganic pigments, titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, as well as carbon black produced by known methods such as the contact method, furnace method, and thermal method can be used.

[0076] In addition, examples of organic pigments that can be used include azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments), dye chelates (e.g., basic dye chelates and acid dye chelates), nitro pigments, nitroso pigments, and aniline black. Of these pigments, those with good affinity for the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.

[0077] Specific examples of pigments for black include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, metals such as copper, iron (CI Pigment Black 11), and titanium oxide, and organic pigments such as aniline black (CI Pigment Black 1).

[0078] In addition, for color, CI Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, CI Pigment Yellow Ranges 5, 13, 16, 17, 36, 43, 51, CI Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48:2, 48:2 (Permanent Red 2B (Ca)), 48:3, 48:4, 49:1, 52:2, 53:1, 57:1 (Brilliant Carmine 6B), 60:1, 63:1, 63:2, 64:1, 81, 83, 88 , 101 (Red Iron), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, CI Pigment Violet 1 (Rhodamine Lake), 3, 5:1, 16, 19, 23, 38; CI Pigment Blue 1, 2, 15 (Phthalocyanine Blue), 15:1, 15:2, 15:3, 15:4 (Phthalocyanine Blue), 16, 17:1, 56, 60, 63; CI Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc.

[0079] The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone, or two or more types may be used in combination. Examples of the dyes include CI Acid Yellow 17, 23, 42, 44, 79, 142, CI Acid Red 52, 80, 82, 249, 254, 289, CI Acid Blue 9, 45, 249, CI Acid Black 1, 2, 24, 94, CI Food Black 1, 2, CI Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, CI Direct Red 1, 4, 9, 80, 81, 225, 227, CI Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, CI Directed Black 19, 38, 51, 71, 154, 168, 171, 195, and CI Reactive Red. 14, 32, 55, 79, 249, and CI Reactive Black 3, 4, and 35.

[0080] The content of the coloring material in the ink is preferably from 0.1% to 15% by mass, more preferably from 1% to 10% by mass, from the viewpoints of improving image density, good fixability, and ejection stability.

[0081] Methods for dispersing a pigment to obtain an ink include a method of introducing a hydrophilic functional group into the pigment to make it a self-dispersing pigment, a method of dispersing the pigment by coating the surface of the pigment with a resin, and a method of dispersing the pigment using a dispersant. As a method for introducing a hydrophilic functional group into a pigment to make it a self-dispersible pigment, for example, a method of adding a functional group such as a sulfone group or a carboxyl group to a pigment (e.g., carbon) to make it dispersible in water can be mentioned.

[0082] One method for dispersing a pigment by coating its surface with a resin is to encapsulate the pigment in microcapsules to make it dispersible in water. This can be rephrased as a resin-coated pigment. In this case, it is not necessary for all of the pigments blended into the ink to be coated with resin; uncoated or partially coated pigments may be dispersed in the ink, provided that the effects of the present invention are not impaired.

[0083] Examples of the method for dispersing using a dispersant include a method for dispersing using a known low molecular weight dispersant or a high molecular weight dispersant, such as a surfactant. As the dispersant, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. can be used depending on the pigment. RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and sodium naphthalenesulfonate formalin condensate can also be suitably used as dispersants. The dispersants may be used alone or in combination of two or more.

[0084] <Pigment dispersion> Ink can be obtained by mixing a pigment with water, an organic solvent, or other materials. Alternatively, ink can be produced by mixing a pigment with other materials such as water and a dispersant to form a pigment dispersion, and then mixing the resulting mixture with water, an organic solvent, or other materials.

[0085] The pigment dispersion is obtained by mixing and dispersing water, pigment, pigment dispersant, and other components as necessary, and adjusting the particle size. Dispersion is preferably performed using a disperser. There are no particular restrictions on the particle size of the pigment in the pigment dispersion. However, in order to improve the dispersion stability of the pigment and image quality such as ejection stability and image density, the maximum frequency, calculated as the maximum number, is preferably 20 nm or more and 500 nm or less, and more preferably 20 nm or more and 150 nm or less. The particle size of the pigment can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

[0086] The content of the pigment in the pigment dispersion is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of obtaining good ejection stability and increasing image density, the content is preferably 0.1% by mass or more and 50% by mass or less, and more preferably 0.1% by mass or more and 30% by mass or less. It is preferable that the pigment dispersion is degassed, if necessary, by filtering coarse particles using a filter, a centrifugal separator, or the like.

[0087] <Resin> The type of resin (resin (3)) contained in the ink is not particularly limited and can be appropriately selected depending on the purpose. Examples include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, and acrylic silicone resin.

[0088] Resin particles made of these resins may also be used. The resin particles are dispersed in water as a dispersion medium to form a resin emulsion, which can be mixed with materials such as coloring materials and organic solvents to obtain an ink. The resin particles may be appropriately synthesized or commercially available. These may be used alone or in combination of two or more types of resin particles.

[0089] The volume average particle size of the resin particles is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of obtaining good fixing properties and high image hardness, the volume average particle size is preferably 10 nm or more and 1,000 nm or less, more preferably 10 nm or more and 200 nm or less, and particularly preferably 10 nm or more and 100 nm or less. The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

[0090] The resin content is not particularly limited and can be selected appropriately depending on the purpose. From the viewpoint of fixability and ink storage stability, however, it is preferably from 1% by mass to 30% by mass, and more preferably from 5% by mass to 20% by mass, of the total amount of ink.

[0091] There are no particular restrictions on the particle size of the solids in the ink and they can be selected appropriately depending on the purpose. However, to improve image quality such as ejection stability and image density, the maximum frequency, calculated as the maximum number, is preferably 20 nm or more and 1000 nm or less, and more preferably 20 nm or more and 150 nm or less. The solids include resin particles and pigment particles. Particle size can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

[0092] The glass transition temperature Tg of the resin (3) contained in the third liquid is preferably higher than the glass transition temperature Tg of the resin (4) contained in the fourth liquid, which can improve transferability and image density.

[0093] <Additives> If necessary, surfactants, antifoaming agents, antiseptic and antifungal agents, antirust agents, pH adjusters, etc. may be added to the ink.

[0094] <Surfactant> As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used.

[0095] Silicone surfactants are not particularly limited and can be appropriately selected depending on the purpose.Among them, those that do not decompose even at high pH are preferred, such as side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and both-end modified polydimethylsiloxane of side chain, and those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group are particularly preferred because they exhibit good properties as aqueous surfactants.In addition, polyether-modified silicone surfactants can also be used as the silicone surfactant, and examples thereof include compounds in which a polyalkylene oxide structure is introduced into the Si part side chain of dimethylsiloxane.

[0096] As fluorosurfactants, for example, perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chain are particularly preferred due to their low foaming properties. Examples of the perfluoroalkyl sulfonic acid compounds include perfluoroalkyl sulfonic acids and perfluoroalkyl sulfonate salts. Examples of the perfluoroalkyl carboxylic acid compounds include perfluoroalkyl carboxylic acids and perfluoroalkyl carboxylate salts. Examples of the polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chain include sulfate ester salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in the side chain, and salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in the side chain. Counterions of the salts in these fluorosurfactants include Li, Na, K, NH, NHCHCHOH, NH(CHCHOH), NH(CHCHOH), and the like.

[0097] Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.

[0098] Examples of nonionic surfactants include polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene propylene block polymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and ethylene oxide adducts of acetylene alcohol.

[0099] Examples of anionic surfactants include polyoxyethylene alkyl ether acetates, dodecylbenzenesulfonates, laurates, and salts of polyoxyethylene alkyl ether sulfates. These may be used alone or in combination of two or more.

[0100] The silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples include side-chain-modified polydimethylsiloxane, both-end-modified polydimethylsiloxane, one-end-modified polydimethylsiloxane, and both-end-modified side-chain polydimethylsiloxane. Polyether-modified silicone surfactants having a polyoxyethylene group or a polyoxyethylene-polyoxypropylene group as the modifying group are particularly preferred because they exhibit good properties as aqueous surfactants.

[0101] Such surfactants may be appropriately synthesized or commercially available products, such as those available from BYK-Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Dow Corning Toray Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd.

[0102] The polyether-modified silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be a surfactant represented by general formula (S-1) in which a polyalkylene oxide structure is introduced into the Si moiety side chain of dimethylpolysiloxane.

[0103] [ka]

[0104] (In the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R' represents an alkyl group.)

[0105] As the polyether-modified silicone surfactant, commercially available products can be used, such as KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX (Nihon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Dow Corning Toray Silicone Co., Ltd.), BYK-33, BYK-387 (BYK-Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicone Co., Ltd.).

[0106] The fluorine-based surfactant is preferably a compound having 2 to 16 fluorine-substituted carbon atoms, more preferably a compound having 4 to 16 fluorine-substituted carbon atoms.

[0107] Examples of fluorine-based surfactants include perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chains. Among these, polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chains are preferred because they have low foaming properties, and fluorine-based surfactants represented by general formula (F-1) and general formula (F-2) are particularly preferred.

[0108] [ka]

[0109] In the compound represented by the above general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility.

[0110] C n F 2n+1 -CH2CH(OH)CH2-O-(CH2CH2O) a -Y General formula (F-2)

[0111] In the compound represented by the general formula (F-2), Y is H or C n F 2n+1 where n is an integer from 1 to 6, or CH2CH(OH)CH2-C n F 2n+1 where n is an integer between 4 and 6, or C p H 2p+1 where p is an integer from 1 to 19, and a is an integer from 4 to 14.

[0112] As the fluorine-based surfactant, commercially available products may be used, such as Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, and FC-431 (all manufactured by Sumitomo 3M Limited); Megafa F-470, F-1405, F-474 (all manufactured by Dainippon Ink and Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by Chemours); FT-110, FT- 250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Corporation), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omnova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.), and among these, FS-3100, FS-34, FS-300 manufactured by Chemours Corporation, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Corporation, Polyfox PF-151N manufactured by Omnova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferred in terms of achieving good print quality, particularly color development, penetration into paper, wettability, and significant improvements in dye leveling.

[0113] The content of the surfactant in the ink is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoints of excellent wettability and ejection stability and improved image quality, it is preferably 0.001% by mass or more and 5% by mass or less, and more preferably 0.05% by mass or more and 5% by mass or less.

[0114] <Antifoaming agent> The antifoaming agent is not particularly limited, and examples thereof include silicone-based antifoaming agents, polyether-based antifoaming agents, fatty acid ester-based antifoaming agents, and the like. These may be used alone or in combination of two or more. Among these, silicone-based antifoaming agents are preferred from the viewpoint of excellent defoaming effect.

[0115] <Preservative and antifungal agent> The preservative and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

[0116] <pH adjuster> The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

[0117] <Physical properties of the ink> The physical properties of the ink are not particularly limited and can be appropriately selected according to the purpose. For example, it is preferable that the viscosity, surface tension, pH, etc. are in the following ranges.

[0118] The viscosity of the ink at 25°C is preferably 5 mPa·s or more and 30 mPa·s or less, and more preferably 5 mPa·s or more and 25 mPa·s or less, from the viewpoints of improved printing density and character quality and good ejection property. Here, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used to measure the viscosity. The measurement conditions are as follows: at 25°C, using a standard cone rotor (1°34’×R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and measurement can be performed in 3 minutes.

[0119] The surface tension of the ink is preferably 35 mN / m or less, and more preferably 32 mN / m or less at 25° C., in order to ensure that the ink is properly leveled on the recording medium and the drying time of the ink is shortened.

[0120] The pH of the ink is preferably 7 to 12, and more preferably 8 to 11, from the viewpoint of preventing corrosion of metal members that come into contact with the ink.

[0121] (Recorded material) The recorded matter of the present invention is obtained by transferring an intermediate image formed on an intermediate transfer body to a recording medium. An image can be formed by an image forming apparatus and an image forming method to produce a recorded matter. The recorded matter may also be called a printed matter.

[0122] (Additional explanation of image forming apparatus and image forming method) The image forming apparatus and image forming method of the present invention may also be referred to as a recording apparatus, a recording method, etc. In the image forming apparatus and image forming method of the present invention, an intermediate image is formed on an intermediate transfer body using a discharge means such as an inkjet head, and the intermediate image is transferred to a recording medium to produce a recorded product. From this perspective, the image forming apparatus and image forming method of the present invention may also be referred to as an inkjet intermediate transfer recording system, etc.

[0123] In this application, a recording apparatus and a recording method refer to an apparatus capable of ejecting ink or various treatment liquids onto a recording medium, and a method of recording using such an apparatus. A recording medium refers to an object onto which ink or various treatment liquids can be attached, even temporarily. This recording apparatus may include not only a head portion that ejects ink, but also means related to feeding, transporting, and discharging the recording medium, as well as other devices known as pre-processing devices and post-processing devices.

[0124] As explained above, the recording apparatus and recording method may include heating and drying using a heating section (e.g., first to third heating sections). Heating means and drying means include, for example, means for heating and drying the printed surface and back surface of the recording medium. The heating means and drying means are not particularly limited, but for example, a hot air heater or an infrared heater can be used. Heating and drying can be carried out before, during, or after printing.

[0125] When an infrared heater is used, at least a near-infrared irradiation device is provided. Known near-infrared irradiation devices include devices consisting of a halogen lamp and a reflective mirror. Commercially available products attempt to achieve efficient heating by incorporating a halogen heater into a reflective mirror to create a heating unit, such as the UH-USC-CL300, UHUSC-CL700, UH-USC-CL1000, UH-USD-CL300, UHUSD-CL700, UH-USD-CL1000, UH-MA1-CL300, UHMA1-CL700, and UH-MA1-CL1000 (all manufactured by Ushio Inc.).

[0126] Furthermore, the recording device and recording method are not limited to those that visualize meaningful images such as letters and figures using ink. For example, they also include those that form patterns such as geometric designs and those that create three-dimensional images.

[0127] Furthermore, unless otherwise specified, the recording apparatus includes both a serial type apparatus in which the ejection head moves and a line type apparatus in which the ejection head does not move. [Example]

[0128] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by mass" and "%" means "% by mass" except in the evaluation criteria.

[0129] (Example of pigment dispersion preparation) <Preparation of Black Pigment Dispersion> The following mixture was premixed and then circulated and dispersed for 7 hours in a disk-type bead mill (KDL model, manufactured by Shinmaru Enterprises Co., Ltd., media: zirconia balls with a diameter of 0.3 mm) to obtain a self-dispersed black pigment dispersion (pigment solids concentration: 15% by mass). Carbon black pigment (product name: Monarch 800, manufactured by Cabot Corporation) 15 parts by weight 2 parts by weight of anionic surfactant (product name: Paionin A-51-B, manufactured by Takemoto Oil & Fat Co., Ltd.) Ion-exchanged water: 83 parts by weight

[0130] <Preparation of each liquid> Ion-exchanged water was added to the formulations in Tables 1 to 4 below so that the total amount was 100 parts, and after mixing, the mixture was mixed and stirred, and filtered through a 5 μm filter (Minisart, manufactured by Sartorius) to obtain each liquid of the examples.

[0131] [Table 1]

[0132] [Table 2]

[0133] [Table 3]

[0134] [Table 4]

[0135] The following resin emulsions were used in the table: AQUACER 531 (polyethylene wax, manufactured by BYK-Chemie) AQUACER 593 (polypropylene wax, manufactured by BYK-Chemie) AQUACER 526 (polyethylene vinyl acetate wax, manufactured by BYK-Chemie) AQUACER 539 (paraffin wax, manufactured by BYK-Chemie) DK6810 (modified polyamine cationic resin, manufactured by Seiko PMC) Superflex 210 (polyurethane resin, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Hi-Loss-X ME-2039 (acrylic resin, manufactured by Seiko PMC) Hi-Loss-X PE-2109 (styrene-acrylic resin, manufactured by Seiko PMC) Superflex 460 (polyurethane resin, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) The melting point and Tg values of each resin are as shown in the table.

[0136] (evaluation) Using each of the obtained liquids, the "transferability," "image density," "fixability (beading)," and "ejection stability" were evaluated as follows. The combinations of the liquids and intermediate transfer members evaluated in each example are shown in Table 5. The results are shown in Table 6.

[0137] The intermediate transfer members used in the table are as follows: Kapton (polyimide, model number 500H, manufactured by Toray DuPont): contact angle of pure water: 48° Silicone rubber sheet (silicone, model number K-125, manufactured by Togawa Rubber Co., Ltd.): contact angle of pure water 101° PFA film (PFA, model number F-8140-001-01, manufactured by Fluoro Industries): contact angle of pure water 107°

[0138] [Table 5]

[0139] <Formation of solid images> An inkjet printer IPSiO GX5000 (manufactured by Ricoh Co., Ltd.) was filled with each of the liquids of Examples 1 to 10 and Comparative Examples 1 to 3, and a 30 mm square solid image was printed at a resolution of 600 dpi on the intermediate transfer body described in each Example and Comparative Example. First, the first liquid was ejected and dried for 1 minute in a thermostatic chamber set at 80°C. Then, the second liquid (pretreatment liquid) and the third liquid (ink) were ejected in the same manner onto the layer of the first liquid. The layer was then dried again for 1 minute in a thermostatic chamber set at 80°C, and then the fourth liquid was ejected in the same manner. Finally, the layer was dried again for 1 minute in a thermostatic chamber set at 80°C, forming a solid image.

[0140] <Transfer of solid image> The solid image thus produced was superimposed on OK Topcoat+ (manufactured by Oji Paper Co., Ltd.), and the intermediate image was transferred by passing it between a heating roller (e.g., equivalent to transfer roller 24 in Figure 1) and a pressure roller (e.g., equivalent to opposing roller 25 in Figure 1) that were nipped together. The heating roller and pressure roller used here were modified versions of the contact heat fixing unit of a RICOH ProC9500 that allowed paper to be manually inserted. The nip pressure was set to 350 kPa, the transport speed to 114 mm / s, and the transfer temperature to 120°C.

[0141] <Transferability> After transfer, the intermediate transfer body was visually inspected to see if any image remained, and then the intermediate transfer body was wiped with a cloth soaked in ethanol to check whether the coloring material was transferred to the cloth, thereby evaluating transferability. The evaluation was based on the following criteria. A rating of B or higher is desirable for practical use.

[0142] [Evaluation criteria] A: No image remains on the intermediate transfer body and no color material is transferred to the waste cloth. B: Image residue is barely visible, but pigment transfer to the cloth is visible. C: There is clearly an image remaining on the intermediate transfer body.

[0143] <Image density> The image density (OD) of the image that had been left standing at room temperature for 24 hours after transfer was measured using an xRite (PANTONE) to evaluate the image density. The evaluation was based on the following criteria: B or higher is within the practical range, with A being preferred.

[0144] [Evaluation criteria] A: 1.8 or higher B: 1.5 or more and less than 1.8 C: Less than 1.5

[0145] <Adhesion (beading)> The solid image formed on the recording medium was visually observed for unevenness in recording, and the "fixing ability (beading)" was evaluated based on the following evaluation criteria. A rating of B or higher is desirable for practical use.

[0146] [Evaluation criteria] A: Very good (no beading at all) B: Good (slight beading observed) C: Poor (significant beading)

[0147] <Discharge stability> A chart was created that filled 5% of the area of an A4-sized sheet of paper with a solid image. Next, the created chart was printed out in 5 sets of 200 sheets continuously onto recording media OK Topcoat+ (Oji Paper), and evaluated based on the irregular discharge of each nozzle after printing. The print mode used was a mode in which the "Plain Paper - Standard Fast" mode was changed to "No Color Correction" from the plain paper user settings in the printer's driver. Evaluation was based on the following criteria. B or above is within the practical range, with A being preferable.

[0148] [Evaluation criteria] A: No disturbance in discharge B: Some irregular discharge C: Discharge is irregular or there are areas where no discharge occurs

[0149] [Table 6]

[0150] It can be seen that Examples 1 and 2 are preferred embodiments of the present invention, and are excellent in transferability, fixability and ejection stability, and can provide images with high image density. In Examples 3 and 4, an intermediate transfer member having a contact angle with pure water of more than 60° was used instead of a polyimide resin, and the image density was inferior to that of Examples 1 and 2. In Examples 5 and 6, a resin other than polyethylene wax or polypropylene wax was used as the resin (1) of the first liquid, and the melting point of the resin (1) was less than 120°C. As a result, the transferability and ejection stability were inferior to those of Examples 1 and 2. Example 7 is an example in which the glass transition temperature of the resin (3) contained in the third liquid is the same as the glass transition temperature of the resin (4) contained in the fourth liquid, and the transferability and image density were inferior to those of Examples 1 and 2. In Example 8, the glass transition temperature Tg of the resin (4) contained in the fourth liquid was 0° C. or higher, and the transferability and image density were inferior to those of Examples 1 and 2. Examples 9 and 10 are examples in which a divalent or higher polyvalent metal salt was not used in the second liquid (pretreatment liquid), and compared to Examples 1 and 2, the transferability, image density, and fixability were inferior.

[0151] Comparative Example 1 is an example in which the first liquid was not used, and the transferability was inferior to that of the examples. Comparative Example 2 is an example in which the second liquid (pre-treatment liquid) was not used, and the fixing performance was inferior to that of the Examples. Comparative Example 3 is an example in which the fourth liquid was not used, and the transferability was inferior to that of the examples.

[0152] The results in Table 6 show that the configuration of the present invention is suitable for an intermediate transfer type image forming apparatus, and that good transferability, fixability, and high image quality can be obtained. Furthermore, Examples 1 to 10 were excellent in transferability, ejection stability, fixability, and image density.

[0153] For example, aspects of the present invention are as follows. <1> an intermediate transfer member; a first ejection means for ejecting a first liquid onto the intermediate transfer body; a second discharge means for discharging a second liquid onto the intermediate transfer body onto which the first liquid has been discharged; a third discharge means for discharging a third liquid onto the intermediate transfer body onto which the second liquid has been discharged; a fourth discharge means for discharging a fourth liquid onto the intermediate transfer body onto which the third liquid has been discharged; a transfer means for applying heat and pressure to the intermediate transfer body and the recording medium, thereby thermally transferring the intermediate image on the intermediate transfer body to the recording medium, The first liquid contains a resin (1), the second liquid is a processing liquid containing a reactant that reacts with the third liquid, the third liquid is an ink containing a coloring material, water, and a resin (3), The fourth liquid includes water and a resin (4). An image forming apparatus characterized by: <2> The intermediate transfer body has a surface onto which the first liquid is ejected, and the contact angle of pure water thereon is 60° or less. Characterized by <1> 2. The image forming apparatus according to claim 1 . <3> The intermediate transfer member contains a polyimide resin. Characterized by <1> or <2> 2. The image forming apparatus according to claim 1 . <4> The resin (1) contained in the first liquid is polyethylene wax or polypropylene wax. Characterized by <1> from <3> 10. The image forming apparatus according to claim 9, wherein: <5> The melting point of the resin (1) contained in the first liquid is 120°C or higher. Characterized by <1> from <4> 10. The image forming apparatus according to claim 9, wherein: <6> The glass transition temperature of the resin (3) contained in the third liquid is higher than the glass transition temperature of the resin (4) contained in the fourth liquid. Characterized by <1> from <5> 10. The image forming apparatus according to claim 9, wherein: <7> The glass transition temperature of the resin (4) contained in the fourth liquid is less than 0°C. Characterized by <1> from <6> 10. The image forming apparatus according to claim 9, wherein: <8> The second liquid contains a polyvalent metal salt having a valence of two or more. Characterized by <1> from <7> 10. The image forming apparatus according to claim 9, wherein: <9> a first drying means for drying the intermediate transfer body after the first discharging means discharges the first liquid and before the second discharging means discharges the second liquid; a second drying means for drying the intermediate transfer body after the third discharging means has discharged the third liquid and before the fourth discharging means has discharged the fourth liquid; and a third drying unit that dries the intermediate transfer body after the fourth discharging unit has discharged the fourth liquid. Characterized by <1> from <8> 10. The image forming apparatus according to claim 9, wherein: <10> The transfer means has a heating roller and a pressure roller facing the heating roller, and thermal transfer is performed by passing the intermediate transfer body and the recording medium through a nip formed by the heating roller and the pressure roller. Characterized by <1> from <9> 10. The image forming apparatus according to claim 9, wherein: <11> a first ejection step of ejecting a first liquid onto an intermediate transfer body; a second discharge step of discharging a second liquid onto the intermediate transfer body onto which the first liquid has been discharged; a third discharge step of discharging a third liquid onto the intermediate transfer body onto which the second liquid has been discharged; a fourth discharge step of discharging a fourth liquid onto the intermediate transfer body onto which the third liquid has been discharged; a transfer step of applying heat and pressure to the intermediate transfer body and the recording medium to thermally transfer the intermediate image on the intermediate transfer body to the recording medium, the first liquid includes a first resin; the second liquid is a processing liquid containing a reactant that reacts with the third liquid, the third liquid is an ink containing a coloring material, water, and a second resin, the fourth liquid includes water and a third resin; An image forming method comprising: [Explanation of symbols]

[0154] 1. Image forming device 10 Intermediate transfer belt 11 First Head 12 Second head 13 Third Head 14 Fourth Head 15 rotating rollers 16 Cleaning roller 20 Recording Media 21 First heating section 22 Second heating section 23 Third heating section 24 Transfer roller 25 Opposing roller [Prior art documents] [Patent documents]

[0155] [Patent Document 1] Japanese Patent Application Publication No. 62-92849 [Patent Document 2] Japanese Patent Application Publication No. 1-226336

Claims

1. an intermediate transfer member; a first ejection means for ejecting a first liquid onto the intermediate transfer body; a second discharge means for discharging a second liquid onto the intermediate transfer body onto which the first liquid has been discharged; a third discharge means for discharging a third liquid onto the intermediate transfer body onto which the second liquid has been discharged; a fourth discharge means for discharging a fourth liquid onto the intermediate transfer body onto which the third liquid has been discharged; a transfer means for applying heat and pressure to the intermediate transfer body and the recording medium, thereby thermally transferring the intermediate image on the intermediate transfer body to the recording medium, The first liquid contains a resin (1), the second liquid is a processing liquid containing a reactant that reacts with the third liquid, the third liquid is an ink containing a coloring material, water, and a resin (3), The fourth liquid comprises water and a resin (4). An image forming apparatus characterized by:

2. The intermediate transfer body has a surface onto which the first liquid is ejected, and the contact angle of pure water thereon is 60° or less.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The intermediate transfer member contains a polyimide resin.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. The resin (1) contained in the first liquid is polyethylene wax or polypropylene wax.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. The melting point of the resin (1) contained in the first liquid is 120° C. or higher.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

6. The glass transition temperature of the resin (3) contained in the third liquid is higher than the glass transition temperature of the resin (4) contained in the fourth liquid.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

7. The glass transition temperature of the resin (4) contained in the fourth liquid is less than 0°C.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

8. The second liquid contains a polyvalent metal salt having a valence of two or more.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. a first drying means for drying the intermediate transfer body after the first discharging means discharges the first liquid and before the second discharging means discharges the second liquid; a second drying means for drying the intermediate transfer body after the third discharging means has discharged the third liquid and before the fourth discharging means has discharged the fourth liquid; and a third drying unit that dries the intermediate transfer body after the fourth discharging unit has discharged the fourth liquid.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

10. The transfer means has a heating roller and a pressure roller facing the heating roller, and thermal transfer is performed by passing the intermediate transfer body and the recording medium through a nip formed by the heating roller and the pressure roller.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

11. a first ejection step of ejecting a first liquid onto an intermediate transfer body; a second discharge step of discharging a second liquid onto the intermediate transfer body onto which the first liquid has been discharged; a third discharge step of discharging a third liquid onto the intermediate transfer body onto which the second liquid has been discharged; a fourth discharge step of discharging a fourth liquid onto the intermediate transfer body onto which the third liquid has been discharged; a transfer step of applying heat and pressure to the intermediate transfer body and the recording medium to thermally transfer the intermediate image on the intermediate transfer body to the recording medium, the first liquid includes a first resin; the second liquid is a processing liquid containing a reactant that reacts with the third liquid, the third liquid is an ink containing a coloring material, water, and a second resin, the fourth liquid includes water and a third resin; An image forming method comprising:

Images