JP2017144736A - Ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording method which includes forming an image and absorbing liquid on a transfer body, followed by transferring the image onto a recording medium, and in which both the transferability and durability of the image are achieved.SOLUTION: The ink jet recording method includes repeating, on a transfer body 102, a step of forming, on the transfer body 102, a first image including a liquid component including water and a water-soluble organic solvent of which the boiling point is higher than that of water as well as a solid insoluble in the liquid component, a step of bringing a porous body 105 into contact with the transfer body 102 on which the first image is formed, thereby forming a second image from which part of the liquid component included in the first image is removed, and a transfer step of heating the second image to a minimum film forming temperature or higher, thereby transferring the second image onto a recording medium 108. In the ink jet recording method, the minimum film forming temperature of the second image is a temperature of 100°C or more, and the first image does not receive a heat history of not less than the boiling point of water between the formation of the first image and the contact of the first image with the porous body 105.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ink jet recording method.

  At the time of image recording by the ink jet method, bleeding that inks applied adjacent to each other and beading that ink that has landed first is attracted to ink that has landed later may occur.

  On the other hand, prior to ink application, a reaction liquid (also referred to as a processing liquid) that increases the viscosity of the ink image by aggregating solids such as a coloring material in the ink is applied, and between the droplet ejection dots. A technique for suppressing bleeding and beading by suppressing interference is known.

  Further, curling or cockling may occur due to excessive absorption of the liquid component in the ink image by the recording medium. In particular, in the method of applying ink after applying the reaction liquid, the total applied amount of the liquid components tends to increase due to the application of the two liquid compositions.

  As one of the methods for solving such a problem, there is a method of reducing a decrease in image quality by drying a recording medium using means such as warm air or infrared rays. In addition, there is a method in which an image is formed on a transfer body, and then a liquid component contained in the image on the transfer body is dried by heat energy, and then the image is transferred to a recording medium such as paper.

  Furthermore, as a means to remove the liquid component contained in the image on the transfer body, the liquid component is absorbed and removed from the ink on the transfer body by using a porous body as a liquid absorbing member without using thermal energy. A method to do this has been proposed (Patent Document 1).

  On the other hand, water-based inks containing water as a main liquid component are used as environmentally friendly inks. In the case of water-based ink, in order to prevent clogging of the nozzle due to drying, it is necessary to add at least about 10 to 30% by mass of a high boiling point solvent (see Patent Document 2). In Patent Document 2, these high-boiling solvents (wetting agents) have a relatively low viscosity in the state of an aqueous solution, but the viscosity increases due to high concentration due to evaporation of moisture, resulting in stickiness of the ink layer and delay in drying. The problem of curl of recording media has been pointed out.

  Further, in Patent Document 2, when an image is formed on a recording medium using an ink containing a color material and a treatment liquid containing a component that causes the color material to aggregate, it is formed after the treatment liquid is applied and ink is deposited. It has been proposed that after the dried ink layer is heated and dried, residual solvent remaining on the recording medium is removed by contacting with a solvent removing means.

JP 2008-19286 A JP 2009-226907 A

  In a transfer-type ink jet recording method in which an aqueous ink is used to form an ink image on a transfer body disclosed in Patent Document 1 and this is transferred to a recording medium such as paper, a liquid component is converted from the ink image onto the transfer body. Transfer is performed by heating to a temperature equal to or higher than the minimum film-forming temperature (MFT) of the solid component (resin emulsion) in the ink image. Patent Document 1 shows that transfer can be performed at a low temperature by using a resin emulsion having a low MFT of 70 ° C. or lower, but an image using a resin emulsion having a low MFT of 70 ° C. or lower may be inferior in fastness. Is done.

  Further, as disclosed in the cited document 2, the configuration in which the liquid component is further absorbed by the liquid absorbing member after the heating is effective when an image is directly formed on the recording medium. However, when it is applied to a transfer type ink jet recording method as in the cited document 1 and an image is formed at high speed, stable transferability may not be obtained.

  The present invention provides an ink jet recording method that achieves both image transferability and robustness in an ink jet recording method in which image formation and liquid absorption are performed on a transfer body and then the image is transferred onto a recording medium. Objective.

  According to one embodiment of the present invention, water and water are passed through a step of applying a reaction liquid containing an ink thickening component and a step of applying an ink containing water and a coloring material on a transfer body. Forming a first image including a liquid component including a water-soluble organic solvent having a higher boiling point, and a solid component insoluble in the liquid component formed by mixing the reaction liquid and the ink. And a liquid removal step of forming a second image in which a part of the liquid component contained in the first image is removed by bringing a porous body into contact with the transfer body on which the first image is formed And a transfer step of heating the second image above the minimum film-forming temperature of the second image and transferring the image onto a recording medium, the inkjet recording method repeatedly performing on the transfer body, Temperature at which the minimum filming temperature of the second image is 100 ° C or higher And the first image is not subjected to a thermal history higher than the boiling point of water between the step of forming the first image and the step of removing the liquid. Is provided.

  Further, according to another embodiment of the present invention, a step of applying a reaction liquid containing an ink thickening component and a step of applying an ink containing water and a coloring material on a transfer body, A first image comprising a liquid component containing water and a water-soluble organic solvent having a boiling point higher than that of water, and a solid content insoluble in the liquid component formed by mixing the reaction liquid and the ink And a liquid removing step of bringing a porous body into contact with the transfer body on which the first image is formed, and concentrating ink constituting the first image to form a second image. A transfer step of heating the second image above the minimum film-forming temperature of the second image and transferring the image onto a recording medium, wherein the second image is repeatedly recorded on the transfer body, The minimum film-forming temperature of the second image is 100 ° C or higher The ink jet recording method, wherein the first image does not receive a thermal history higher than the boiling point of water between the step of forming the first image and the step of removing the liquid. Is provided.

  In an ink jet recording method in which a porous body is brought into contact with an image and transferred after absorbing the liquid, image fastness and transferability can be both achieved and high-quality image formation can be achieved.

1 is a schematic diagram illustrating an example of a configuration of a transfer type inkjet recording apparatus according to the present invention. It is a schematic diagram which shows another example of a structure of the transfer type inkjet recording device in this invention. FIG. 2 is a block diagram illustrating a control system for the entire apparatus in the ink jet recording apparatus illustrated in FIG. 1. FIG. 2 is a block diagram of a printer control unit in the transfer type inkjet recording apparatus shown in FIG. 1. It is a figure which shows the composition change in the image in drying and liquid absorption.

As a result of repeated studies from various viewpoints, the present inventors have an idea that the MFT of the solid component (resin emulsion) in the ink image is preferably, for example, 100 ° C. or higher in order to increase the fastness of the image. Obtained. In such a condition, it is also important that the temperature of the solid component (resin emulsion) in the ink image at the time of transfer is 100 ° C. or higher in order to achieve both transferability.
On the other hand, in the case of transfer recording, new knowledge has been obtained that there is a preferable order for drying by heating and removal of liquid components by the liquid absorbing member.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments.
An ink jet recording method according to an embodiment of the present invention includes a step of applying a reaction liquid containing an ink thickening component and a step of applying an ink containing water and a coloring material on a transfer body, A first image comprising a liquid component containing water and a water-soluble organic solvent having a boiling point higher than that of water, and a solid content insoluble in the liquid component formed by mixing the reaction liquid and the ink And forming a second image in which a part of the liquid component contained in the first image is removed by bringing a porous body into contact with the transfer body on which the first image is formed. An ink jet recording method in which a liquid removal step and a transfer step in which the second image is heated to a temperature equal to or higher than the minimum film forming temperature of the second image and transferred onto a recording medium are repeatedly performed on the transfer body. The minimum film-forming temperature of the second image Is a temperature of 100 ° C. or higher, and the first image is not subjected to a thermal history higher than the boiling point of water between the step of forming the first image and the step of removing the liquid. It is characterized by.

  In particular, the step of forming the first image includes a step of applying a reaction liquid containing an ink thickening component and a step of applying ink on the transfer body. The order of the step of applying the reaction liquid on the transfer member and the step of applying the ink on the transfer member is not particularly limited, but from the viewpoint of improving the image quality, the step of forming the first image is: It is preferable to have in this order a step of applying a reaction liquid on the transfer body and a step of applying ink on the transfer body. That is, the first image forming step includes a step of applying a reaction liquid on the transfer body, and a step of applying the ink on the transfer body so that at least a part of the region to which the reaction liquid is applied overlaps. Are preferably included in this order. Therefore, the apparatus for applying the reaction liquid on the transfer body and the apparatus for applying the ink on the transfer body apply the reaction liquid on the transfer body so that at least a part of the region to which the reaction liquid is applied overlaps. It is preferable that the ink is disposed so that the ink can be applied thereto. Hereinafter, the ink jet recording method of this embodiment in which the first image is applied by applying the reaction liquid and applying the ink will be described. The first image refers to an ink image before liquid removal before being subjected to liquid absorption processing by the liquid absorption member. The ink image after liquid removal in which the content of the first liquid is reduced by performing the liquid absorption process is referred to as a second image. In the following description, as a pretreatment for the porous body used for the liquid absorbing member, a process of pre-wetting the porous body with a wetting liquid will be described.

<Transfer>
The transfer body applied to the present invention has a surface layer including an image forming surface. As the member for the surface layer, various materials such as resin and ceramic can be used as appropriate, but a material having a high compression elastic modulus is preferable in terms of durability and the like. Specific examples include condensates obtained by condensing acrylic resins, acrylic silicone resins, fluorine-containing resins, and hydrolyzable organosilicon compounds. In order to improve the wettability and transferability of the reaction solution, surface treatment may be performed. Examples of the surface treatment include flame treatment, corona treatment, plasma treatment, polishing treatment, roughening treatment, active energy ray irradiation treatment, ozone treatment, surfactant treatment, and silane coupling treatment. A plurality of these may be combined. Moreover, arbitrary surface shapes can also be provided in the surface layer.

  The transfer body applied to the present invention preferably has a compression layer having a function of absorbing pressure fluctuations. By providing the compression layer, the compression layer absorbs deformation, disperses the fluctuation with respect to the local pressure fluctuation, and can maintain good transferability even during high-speed printing. Examples of the member of the compression layer include acrylonitrile-butadiene rubber, acrylic rubber, chloroprene rubber, urethane rubber, and silicone rubber.

  In molding the rubber material, a predetermined amount of a vulcanizing agent, a vulcanization accelerator, and the like are blended, and a filler such as a foaming agent, hollow fine particles, or salt is blended as necessary to make it porous. Thereby, since the bubble part is compressed with a volume change with respect to various pressure fluctuations, deformation in the direction other than the compression direction is small, and more stable transferability and durability can be obtained. The porous rubber material includes a continuous pore structure in which the pores are continuous with each other and an independent pore structure in which the pores are independent from each other. In the present invention, any structure may be used, and these structures may be used in combination.

  The transfer body applied to the present invention preferably has an elastic layer between the surface layer and the compression layer. As the member of the elastic layer, various materials such as resin and ceramic can be used as appropriate. Various elastomer materials and rubber materials are preferably used in terms of processing characteristics and the like. Specifically, for example, fluorosilicone rubber, phenyl silicone rubber, fluoro rubber, chloroprene rubber, urethane rubber, nitrile rubber, ethylene propylene rubber, natural rubber, styrene rubber, isoprene rubber, butadiene rubber, ethylene / propylene / butadiene copolymer, A nitrile butadiene rubber etc. are mentioned. In particular, silicone rubber, fluorosilicone rubber, and phenyl silicone rubber are preferable in terms of dimensional stability and durability because they have a small compression set. Further, the change in elastic modulus with temperature is small, which is preferable in terms of transferability.

  In the present invention, various adhesives and double-sided tapes may be used between the surface layer, the elastic layer, and the compression layer in order to fix and hold them. Moreover, you may provide the reinforcement layer with a high compression elastic modulus in order to suppress lateral elongation at the time of mounting | wearing with an apparatus, and to maintain a firmness. A woven fabric may be used as the reinforcing layer. The transfer body can be produced by arbitrarily combining the layers made of the above materials.

  The size of the transfer body can be freely selected according to the target print image size. The shape of the transfer body is not particularly limited, and specific examples include a sheet shape, a roller shape, a belt shape, and an endless web shape.

<Reaction liquid application process>
For applying the reaction liquid, any apparatus that can apply the reaction liquid onto the transfer body may be used, and various conventionally known apparatuses can be appropriately used. Specific examples include a gravure offset roller, an inkjet head, a die coating device (die coater), a blade coating device (blade coater), and the like. In particular, an apparatus that can uniformly apply the reaction liquid to all regions on the transfer body that can be applied by an ink applying apparatus described later is preferable. By applying the reaction liquid before applying the ink, at the time of image recording by the ink jet method, bleeding in which adjacently applied inks are mixed together, or the ink that has landed first is attracted to the ink that has landed later. Ding can be suppressed.

<Reaction solution>
The reaction liquid contains a component for increasing the viscosity of the ink (ink viscosity increasing component). Here, increasing the viscosity of the ink means that the coloring material or resin, which is a component of the ink, reacts chemically or physically adsorbs by contacting the increased viscosity component of the ink. The increase in the ink viscosity is recognized. In order to increase the viscosity of the ink, not only when an increase in the ink viscosity is observed, but also when the viscosity of the ink locally increases due to agglomeration of a part of the components constituting the ink such as a coloring material and resin included. This ink viscosity-increasing component reduces the fluidity of the ink and / or a part of the component constituting the ink on the transfer body, thereby suppressing bleeding and beading during the first image formation. There is.

  In the present invention, increasing the viscosity of the ink is also referred to as “viscosity of the ink”. As such an ink viscosity increasing component, known ones such as polyvalent metal ions, organic acids, cationic polymers, and porous fine particles can be used. Of these, polyvalent metal ions and organic acids are particularly suitable. It is also preferable to include a plurality of types of ink thickening components. The content of the ink viscosity increasing component in the reaction liquid is preferably 5% by mass or more based on the total mass of the reaction liquid.

Examples of the polyvalent metal ions include divalent metal ions such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Sr ²⁺ , Ba ²⁺ and Zn ²⁺ , Fe ³⁺ , Cr ³⁺ , Y ³⁺ and Al ^3+. Of the trivalent metal ions.

  Examples of organic acids include oxalic acid, polyacrylic acid, formic acid, acetic acid, propionic acid, glycolic acid, malonic acid, malic acid, maleic acid, ascorbic acid, levulinic acid, succinic acid, glutaric acid, glutamic acid, and fumaric acid. Citric acid, tartaric acid, lactic acid, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, oxysuccinic acid, dioxysuccinic acid and the like.

  The reaction solution can contain an appropriate amount of water or a water-soluble organic solvent having a boiling point higher than that of water. The water used in this case is preferably water deionized by ion exchange or the like. Moreover, it does not specifically limit as a water-soluble organic solvent which can be used for the reaction liquid in this embodiment, The water-soluble organic solvent which can be used for the ink mentioned later can be used.

  The reaction liquid can be used by appropriately adjusting the surface tension and viscosity by adding a surfactant or a viscosity modifier. The material used is not particularly limited as long as it can coexist with the ink thickening component. Specifically used surfactants include acetylene glycol ethylene oxide adduct (“acetylenol E100”, Kawaken Fine Chemical Co., Ltd., trade name), perfluoroalkylethylene oxide adduct (“Megafac F444”, “Megafac TF”). -2066 ", a product name of DIC Corporation, and the like.

The application amount of the reaction liquid may be an application amount that can form a substantially uniform layer when applying the reaction liquid to all regions on the transfer body that can be applied by the ink application device. Thereby, the fall of the roundness of an ink dot can be suppressed. In addition, application of an excessive reaction liquid may shrink more than necessary in the process of agglomerating ink solids, and image quality may be impaired. From this point of view, the application amount of the reaction liquid in the present embodiment is preferably from 0.05 g / ^{m 2} or more 2 g / ^{m 2} or less, 0.1 g / ^{m 2} or more 1.3 g / ^{m 2} or less is more preferable.

<Ink application process>
An ink jet head is used as an ink application device for applying ink. As an inkjet head, for example, an ink is ejected by forming a bubble by causing film boiling in the ink by an electro-thermal converter, a form in which the ink is ejected by an electro-mechanical converter, and an ink using static electricity. The form etc. which discharge are mentioned. In this embodiment, a known inkjet head can be used. Among these, those using an electro-thermal converter are preferably used from the viewpoint of high-speed and high-density printing. Drawing receives an image signal and applies a necessary ink amount to each position.

The ink application amount can be expressed by the image density (duty) and the ink thickness. In this embodiment, the ink application amount (g / m) is obtained by multiplying the mass of each ink dot by the application number and dividing by the printing area. ² ). Note that the maximum ink application amount in the image region indicates the ink application amount applied in an area of at least 5 mm ² or more in the region used as information of the transfer body from the viewpoint of removing the liquid component in the ink. .

  The ink jet recording apparatus of this embodiment may have a plurality of ink jet heads in order to apply each color ink onto the transfer body. For example, when each color image is formed using yellow ink, magenta ink, cyan ink, and black ink, the ink jet recording apparatus has four ink jet heads that respectively eject the four types of ink onto a transfer body.

  In addition, the ink application device may include an inkjet head that ejects ink (clear ink) that does not contain a color material.

<Ink>
Each component of the ink applied to this embodiment will be described.

(Color material)
As a color material contained in the ink applied to the present embodiment, a pigment or a mixture of a dye and a pigment can be used. The kind of pigment that can be used as the color material is not particularly limited. Specific examples of the pigment include inorganic pigments such as carbon black; organic pigments such as azo, phthalocyanine, quinacridone, isoindolinone, imidazolone, diketopyrrolopyrrole, and dioxazine. These pigments can be used alone or in combination of two or more as required.

  The kind of dye that can be used as the color material is not particularly limited. Specific examples of the dye include direct dyes, acid dyes, basic dyes, disperse dyes, food dyes, and the like, and dyes having an anionic group can be used. Specific examples of the dye skeleton include an azo skeleton, a triphenylmethane skeleton, a phthalocyanine skeleton, an azaphthalocyanine skeleton, a xanthene skeleton, and an anthrapyridone skeleton.

  The content of the pigment in the ink is preferably 0.5% by mass or more and 15.0% by mass or less, and more preferably 1.0% by mass or more and 10.0% by mass or less with respect to the total mass of the ink. .

(Dispersant)
As the dispersing agent for dispersing the pigment, a known dispersing agent used for ink jet inks can be used. In particular, in the present embodiment, it is preferable to use a water-soluble dispersant having both a hydrophilic part and a hydrophobic part in the structure. In particular, a pigment dispersant made of a resin obtained by copolymerizing at least a hydrophilic monomer and a hydrophobic monomer is preferably used. There is no restriction | limiting in particular about each monomer used here, A well-known thing is used suitably. Specifically, examples of the hydrophobic monomer include styrene and other styrene derivatives, alkyl (meth) acrylate, and benzyl (meth) acrylate. Examples of the hydrophilic monomer include acrylic acid, methacrylic acid, maleic acid and the like.

  The acid value of the dispersant is preferably 50 mgKOH / g or more and 550 mgKOH / g or less. Moreover, it is preferable that the weight average molecular weights of this dispersing agent are 1000 or more and 50000 or less. The mass ratio of pigment to dispersant (pigment: dispersant) is preferably in the range of 1: 0.1 to 1: 3.

  It is also preferable to use a so-called self-dispersing pigment that does not use a dispersant, but that can be dispersed by surface modification of the pigment itself.

(Resin fine particles)
The ink used in the present embodiment can be used by containing various fine particles having no color material. Among these, resin fine particles are preferable because they may be effective in improving image quality and fixability. The material of the resin fine particles that can be used in the present embodiment is not particularly limited, and a known resin can be used as appropriate. Specifically, a homopolymer such as polyolefin, polystyrene, polyurethane, polyester, polyether, polyurea, polyamide, polyvinyl alcohol, poly (meth) acrylic acid and its salt, poly (meth) acrylate alkyl, polydiene, or the like And a copolymer obtained by polymerizing a plurality of monomers for producing these homopolymers.

  The weight average molecular weight (Mw) of the resin is preferably in the range of 1,000 to 2,000,000. Further, the amount of the resin fine particles in the ink is preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 40% by mass or less with respect to the total mass of the ink.

  Furthermore, in the aspect of this embodiment, it is preferable to use the resin fine particle dispersion in which the resin fine particles are dispersed in a liquid. A dispersion method is not particularly limited, but a so-called self-dispersing resin fine particle dispersion in which a monomer having a dissociable group is homopolymerized or a resin obtained by copolymerizing a plurality of types is preferably used. Here, examples of the dissociable group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group, and examples of the monomer having this dissociable group include acrylic acid and methacrylic acid. A so-called emulsification-dispersed resin fine particle dispersion in which resin fine particles are dispersed with an emulsifier can also be suitably used in this embodiment.

  As the emulsifier, a known surfactant is preferable regardless of the low molecular weight or high molecular weight. The surfactant is preferably a nonionic surfactant or a surfactant having the same charge as the resin fine particles.

  The resin fine particle dispersion used in the present embodiment preferably has a dispersed particle size of 10 nm to 1000 nm, and more preferably has a dispersed particle size of 100 nm to 500 nm.

  It is also preferable to add various additives for stabilization when preparing the resin fine particle dispersion used in the present embodiment. Examples of the additive include n-hexadecane, dodecyl methacrylate, stearyl methacrylate, chlorobenzene, dodecyl mercaptan, blue dye (bluing agent), and polymethyl methacrylate.

  In particular, the ink according to the present embodiment preferably includes a film-forming component having a minimum film-forming temperature of 100 ° C. or higher. As a film-forming component for that purpose, it is preferable to contain wax particles in addition to the resin fine particles.

  By including wax particles in the ink, it is presumed that when the image is heated and the minimum film-forming temperature (MFT) is exceeded, film formation proceeds sharply and transferability is improved. Examples of the components of the wax particles include natural wax and synthetic wax. Examples of natural waxes include petroleum waxes, plant waxes, and animal and plant waxes. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and petrolatum. Examples of the plant wax include carnauba wax, candelilla wax, rice wax, and wood wax. Examples of animal plant waxes include lanolin and beeswax. Examples of synthetic waxes include synthetic hydrocarbon waxes and modified waxes. Examples of the synthetic hydrocarbon wax include polyethylene wax and Fischer-Trobsch wax. Examples of the modified wax system include paraffin wax derivatives, montan wax derivatives, or microcrystalline wax derivatives. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The wax particles are preferably added to the ink in the form of a wax particle dispersion in which the wax particles are dispersed in a liquid. The wax particles are preferably formed by dispersing a wax component with a dispersant. The dispersant is not particularly limited. For example, a known dispersant can be used, but it is preferable to select the dispersant in consideration of the stability of the dispersion state in the ink.

  In addition, the average particle diameter (number-based 90% particle diameter) of the wax particles is preferably 1 μm or less in consideration of the discharge property of the ink using the ink jet method.

(Curing component)
In this invention, it is preferable to contain the component hardened | cured with an active energy ray in either a reaction liquid or ink. By curing the component that is cured by the active energy ray before the liquid removal step, the color material adhesion to the liquid absorbing member may be suppressed.

  As the component that is cured by irradiation with active energy rays used in the present invention, a component that is cured by irradiation with active energy rays and becomes insoluble before irradiation is used. As an example, a general ultraviolet curable resin can be used. Although many UV curable resins are insoluble in water, as a material that can be applied to the water-based ink suitably used in the present invention, the structure has at least an ethylenically unsaturated bond that can be cured by UV rays and is hydrophilic. It is preferable to have a bonding group of Examples of the bonding group for having hydrophilicity include a hydroxyl group, a carboxyl group, a phosphoric acid group, a sulfonic acid group and salts thereof, an ether bond, and an amide bond. Further, the curing component used in the present invention is preferably hydrophilic.

  Examples of active energy rays include ultraviolet rays, infrared rays, and electron beams.

  Furthermore, in the present invention, it is preferable that a polymerization initiator is included in either the reaction liquid or the ink. The polymerization initiator used in the present invention may be any compound as long as it is a compound that generates radicals by active energy rays.

  Furthermore, it is also a very preferable form to use a sensitizer having the role of extending the absorption wavelength of light in order to improve the reaction rate.

(Surfactant)
The ink that can be used in this embodiment may contain a surfactant. Specific examples of the surfactant include acetylene glycol ethylene oxide adducts (acetylene E100, manufactured by Kawaken Fine Chemical Co., Ltd.). The amount of the surfactant in the ink is preferably 0.01% by mass or more and 5.0% by mass or less with respect to the total mass of the ink.

(Water and water-soluble organic solvents)
The ink used in this embodiment contains water as a liquid medium (solvent or dispersion medium). The water is preferably water deionized by ion exchange or the like. The water content in the ink is preferably 30% by mass to 97% by mass with respect to the total mass of the ink, and more preferably 50% by mass to 95% by mass with respect to the total mass of the ink. preferable.

  The ink may contain a water-soluble organic solvent. The kind of water-soluble organic solvent is not particularly limited, and any known organic solvent can be used. Specifically, glycerin, diethylene glycol, polyethylene glycol, polypropylene glycol, ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol, ethylene glycol monomethyl ether, diethylene glycol monomethyl having a boiling point higher than that of water Examples include ether and 2-pyrrolidone. Moreover, ethanol, methanol, etc. whose boiling point is lower than water can also be included. Of course, a mixture of two or more selected from these can also be used.

  The content of the water-soluble organic solvent in the ink is preferably 3% by mass or more and 70% by mass or less with respect to the total mass of the ink. A water-soluble organic solvent having a boiling point higher than that of water may be referred to as a high-boiling water-soluble organic solvent.

  Further, although details will be described later, in the present invention, the first image is not subjected to a thermal history higher than the boiling point of water after the step of forming the first image and before the liquid removal step. It is characterized by. The boiling point of water in the present invention refers to the value of the boiling point of water at atmospheric pressure.

  In the present invention, water is preferably the main component of the liquid medium in the ink. By being water, it can be suitably used for an inkjet head using an electro-thermal converter capable of high-speed and high-density printing.

(Other additives)
In addition to the above components, the ink that can be used in this embodiment is a pH adjuster, a rust inhibitor, an antiseptic, an antifungal agent, an antioxidant, an anti-reduction agent, a water-soluble resin, and neutralization thereof, as necessary You may contain various additives, such as an agent and a viscosity modifier.

  The first image formed by mixing the reaction liquid and the ink contains water and a water-soluble organic solvent having a boiling point higher than that of water as a liquid component. For this reason, at least one of the reaction liquid and the ink contains a water-soluble organic solvent having a boiling point higher than that of water. The water-soluble organic solvent having a higher boiling point than water in the first image is preferably contained in an amount of 3% by mass or more of the entire image, and more water is contained.

<Liquid removal process>
In this embodiment, a liquid component is absorbed by making it contact with the liquid absorption member which has a porous body in a 1st image, and content of the liquid component in a 1st image is reduced. A contact surface with the first image of the liquid absorbing member is a first surface, and a porous body is disposed on the first surface. The liquid absorbing member having such a porous body moves in conjunction with the movement of the transfer body, comes into contact with the first image, and then circulates in contact with another first image at a predetermined cycle. It is preferable to have a shape capable of absorbing liquid. Examples of the shape include an endless belt shape and a drum shape. The liquid removal process may be referred to as a liquid absorption process.

  In the present embodiment, it is preferable that the temperature of the first image after the first image forming step before the liquid removing step is lower than the boiling point of water. Among these, it is more preferable that the temperature of the first image after the ink application step and before the liquid removal step is lower than the boiling point of water. As a result of intensive studies by the present inventors, if much water contained in the ink evaporates after the first image forming process and before the liquid removing process, the boiling point is higher than that in the liquid removing process. It has been found that the removability of the secondary solvent (water-soluble organic solvent) may decrease. This is because the high-boiling auxiliary solvent contained in the remaining liquid is obtained by increasing the viscosity due to evaporation of the ink liquid medium and the amount of absolute liquid remaining between the coloring material and resin fine particles in the image is constant regardless of the degree of evaporation. It is estimated that this is because the amount of the high-boiling auxiliary solvent remaining after drying increases.

  When the residual amount of liquid contained in the image is large, the fretting property of the image is reduced, so the temperature of the image between the first image forming process and before the liquid removing process is It is preferable that it is less than the boiling point of the contained water. Therefore, it is important that the first image does not receive a thermal history higher than the boiling point of water between the step of forming the first image and the step of removing the liquid.

  In addition, it is preferable that the maximum temperature of the first image after the step of forming the first image and before the liquid removing step is lower by 30 ° C. or more than the boiling point of water contained in the ink. That is, the maximum temperature of the first image is preferably 70 ° C. or lower. This is considered to be because the liquid absorption performance is improved because the suppression of evaporation becomes more conspicuous at a temperature difference of a certain level or higher where the maximum temperature of the first image and the boiling point of water are certain.

The amount of the water-soluble organic solvent having a boiling point higher than that of water in the second image immediately after the second image formation is preferably 0.9 g / m ² or less. By reducing the amount of the water-soluble organic solvent having a boiling point higher than that of water in the second image to 0.9 g / m ² or less, the fastness of the image can be maintained higher.

(Porous body)
The porous body of the liquid absorbing member according to the present embodiment preferably uses a material having an average pore diameter on the first surface side smaller than the average pore diameter on the second surface side facing the first surface. In order to suppress adhesion of ink solid content (solid content formed by mixing the reaction liquid and ink) to the porous body, the pore diameter is preferably small, and at least the porosity on the first surface side in contact with the image The average pore size of the material is preferably 10 μm or less. In the present embodiment, the average pore diameter means an average diameter on the surface of the first surface or the second surface, and can be measured by a known means such as a mercury intrusion method, a nitrogen adsorption method, or an SEM image observation. is there.

  Further, it is preferable to reduce the thickness of the porous body in order to obtain a uniform high air permeability. The air permeability can be indicated by a Gurley value defined by JIS P8117, and the Gurley value is preferably 10 seconds or less. However, if the porous body is thinned, the capacity necessary for absorbing the liquid component may not be sufficiently secured, so the porous body can have a multilayer structure.

  Next, an embodiment in which the porous body has a multilayer structure will be described. Here, the first layer on the side in contact with the first image and the layer laminated on the surface of the first layer opposite to the contact surface with the first image will be described as the second layer. Further, the multilayer structure is also expressed in the order of stacking from the first layer. In the present specification, the first layer may be referred to as an “absorbing layer” and the second and subsequent layers may be referred to as a “support layer”. In the present invention, the porous body may be a material having a large number of pores. For example, a material having a large number of pores formed by crossing fibers is also included in the porous body of the present invention.

[First layer]
In the present embodiment, the material of the first layer is not particularly limited, and either a hydrophilic material having a contact angle with water of less than 90 ° or a water repellent material having a contact angle of 90 ° or more is used. be able to. The hydrophilic material is preferably selected from a single material such as cellulose or polyacrylamide, or a composite material thereof. Moreover, the surface of the following water-repellent material can also be used after being hydrophilized. Examples of the hydrophilic treatment include a sputter etching method, irradiation with radiation and H ₂ O ions, and excimer (ultraviolet) laser light irradiation.

  In the case of a hydrophilic material, the contact angle with water is more preferably 60 ° or less. In the case of a hydrophilic material, there is an effect of sucking up liquid, particularly water, by capillary force.

  On the other hand, the first layer material is preferably a water-repellent material having a low surface free energy, particularly a fluororesin, in order to enhance the colorant adhesion suppression and cleaning properties. Specific examples of the fluororesin include polytetrafluoroethylene (hereinafter PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), perfluoroalkoxy fluororesin (PFA), Examples thereof include tetrafluoroethylene / hexafluoropropylene copolymer (FEP), ethylene / tetrafluoroethylene copolymer (ETFE), and ethylene / chlorotrifluoroethylene copolymer (ECTFE). These resins can be used singly or in combination of two or more as required, and may have a structure in which a plurality of films are laminated in the first layer.

  In the case of a water-repellent material, there is almost no effect of sucking up the liquid by capillary force, and it may take time to suck up the liquid when contacting the image for the first time. For this reason, it is preferable to impregnate the first layer with a liquid having a contact angle with the first layer of less than 90 °.

  The liquid that is soaked in the first layer with respect to the liquid in the first image may be referred to as a preliminary permeation liquid. A reaction solution can also be used as the preliminary permeation solution. By applying from the first surface of the liquid absorbing member, it can be soaked in the first layer. The preliminary osmotic solution is preferably prepared by mixing the first liquid (water) with a liquid having a low contact angle with the surfactant or the first layer.

  In the present embodiment, the film thickness of the first layer is preferably 50 μm or less. The film thickness is more preferably 30 μm or less. In the examples described below, the film thickness was obtained by measuring the film thickness at any 10 points with a straight-forward micrometer OMV — 25 (manufactured by Mitutoyo) and calculating the average value.

  The first layer can be produced by a known method for producing a thin film porous membrane. For example, the resin material can be obtained by obtaining a sheet-like material by a method such as extrusion and then stretching it to a predetermined thickness. Further, a porous film can be obtained by adding a plasticizer such as paraffin to the material at the time of extrusion molding and removing the plasticizer by heating at the time of stretching. The pore diameter can be adjusted by appropriately adjusting the amount of plasticizer to be added, the draw ratio, and the like.

[Second layer]
The second layer is preferably a breathable layer. Such a layer may be a non-woven fabric of resin fibers or a woven fabric. The material of the second layer is not particularly limited, but the contact angle with the first liquid is equal to or greater than that of the first layer so that the liquid absorbed toward the first layer does not flow backward. A low material is preferred. Specifically, a single material such as polyolefin (polyethylene (PE), polypropylene (PP), etc.), polyurethane, nylon, etc., polyester (polyethylene terephthalate (PET), etc.), polysulfone (PSF), or the like The composite material is preferably selected. The second layer is preferably a layer having a larger pore size than the first layer.

[Third layer]
The porous body having a multilayer structure may have three or more layers, and is not limited. The layer after the third layer (also referred to as the third layer) is preferably a nonwoven fabric from the viewpoint of rigidity. The same material as the second layer is used.

[Other materials]
The liquid absorbing member may include a reinforcing member that reinforces the side surface of the liquid absorbing member in addition to the porous body having the above-described laminated structure. Moreover, you may have a joining member at the time of connecting the longitudinal direction edge part of a elongate sheet-shaped porous body to make a belt-shaped member. As such a material, a non-porous tape material or the like can be used, and it may be arranged at a position or a period not in contact with the image.

[Method for producing porous body]
The method for forming the porous body by laminating the first layer and the second layer is not particularly limited. They may be simply overlapped or may be bonded together using a method such as adhesive lamination or heat lamination. From the viewpoint of air permeability, thermal lamination is preferable in the present embodiment. Further, for example, a part of the first layer or the second layer may be melted and laminated by heating. Alternatively, a fusing material such as hot melt powder may be interposed between the first layer and the second layer and bonded together by heating. When the third layer or more are stacked, they may be stacked at once or sequentially, and the stacking order is appropriately selected.

  In the heating step, a laminating method is preferred in which the porous body is heated while sandwiching and pressing the porous body with a heated roller.

<Transfer process>
A part of the liquid component is removed from the first image by the porous body, and a second image is formed. The second image is then heated and transferred onto the recording medium.

(Second image heating)
In the present embodiment, by heating the second image on the transfer body, a part of the solid content (for example, resin fine particles or aggregates of resin fine particles) in the second image is softened to make paper or the like Transfer onto a recording medium. At this time, by heating above the minimum film-forming temperature of the film-forming component such as resin fine particles, the resin fine particles are melted on the transfer body and contacted with the low-temperature recording medium to improve adhesion. Therefore, it is assumed that the transfer is performed well.

  In the present invention, the minimum film-forming temperature (also referred to as MFT) of the second image is the minimum film-forming temperature of ink or a mixture of ink and reaction liquid. Specifically, when the reaction solution contains components that affect the value of the minimum film-forming temperature, such as a film-forming aid, the minimum film-forming temperature is measured using a mixture of ink and reaction solution as the measurement target. The obtained result is set as the minimum film forming temperature of the second image. In addition, when the reaction liquid does not contain a component that affects the value of the minimum film-forming temperature, such as a film-forming auxiliary, the minimum film-forming temperature is measured using ink as a measurement target, and the obtained result is The minimum film-forming temperature of the image. In addition, the minimum film-forming temperature of the ink or the mixture of the ink and the reaction liquid can be measured by a generally known method, for example, each device based on JIS K 6828-2: 2003 or ISO 2115: 1996. Is possible. For example, when measuring the minimum film-forming temperature of ink, the minimum film-forming temperature (MFT) was evaluated after drying each ink at room temperature using the apparatus mentioned above.

  As a heating method, for example, known means such as irradiation with various lamps such as infrared rays or a warm air fan is used. Among them, it is preferable to use an infrared heater because of high heating efficiency.

  In the present embodiment, it is important for the MFT of the second image to be 100 ° C. or higher in order to obtain an image having excellent fastness. The transfer of the second image to the recording medium is performed at a temperature equal to or higher than the MFT. From the viewpoint of transferability and image robustness, it is preferably 10 ° C. or higher, and preferably 20 ° C. or higher. More preferred.

(Cooling process)
In the present embodiment, in order to repeatedly perform image formation, liquid removal, and transfer, it is preferable to have a cooling step of cooling the transfer body after transfer. In particular, it is more preferable to have a cooling step for cooling the transfer body below the boiling point of water before the liquid removal step, and after the transfer step until before the step of forming the first image, It is further preferable to have a cooling step for cooling the transfer body below the boiling point of water. After the transfer step and before the step of forming the first image, the transfer body is cooled, and then after the step of forming the first image again and before the liquid removal step. In the meantime, it is possible to suppress the evaporation of the liquid component from the image. The cooling is controlled so that the image is lower than the boiling point of water in the ink at the timing when the liquid removing step is performed. Further, it is more preferable that the ink is applied at a timing lower than the boiling point of water in the ink.

  FIG. 5 shows an example of the temperature of the transfer body and the composition of the image before and after liquid absorption. As an initial value, after forming an image in which the solid content is about 13%, the high boiling point solvent content (water-soluble organic solvent) is about 15%, and the balance is made of water, the transfer body before the liquid removal step is formed. It can be seen that the amount of moisture dried varies depending on the temperature. In particular, when the boiling point of water is 100 ° C. or higher, the amount of drying increases. In liquid absorption (liquid removal) using a porous body, a certain amount of liquid remains regardless of the temperature of the transfer body. That is, in the liquid removal step, the liquid component is uniformly absorbed, and the composition ratio of the liquid component after liquid absorption is determined by evaporation before liquid absorption. Although water evaporates during the transfer process, the solvent having a boiling point higher than that of water does not evaporate and remains in the transferred image. When the liquid component remains in the transferred image, the fastness of the image is lowered.

  On the other hand, the transferability of an image depends on the transfer temperature. In an ink jet recording method using an aqueous ink, an ink having a low MFT does not need to be transferred at a high temperature, and sufficient liquid removal using drying may not be possible. It is advantageous to transfer at temperature. In addition, with an ink having a low MFT, even if it is transferred at a high temperature, the robustness of the image itself is lower than when an ink having a high MFT is used. In this way, the present invention achieves both image transferability and fastness, and performs excellent image formation.

  Examples of the ink jet recording apparatus to which the present invention is applied include an ink jet recording apparatus that forms an image on a transfer member and transfers the image onto a recording medium.

  The ink jet recording apparatus will be described below. In the present invention, an ink jet recording apparatus that forms an image on a transfer member and transfers it to a recording medium is hereinafter referred to as a transfer type ink jet recording apparatus for convenience.

(Transfer type inkjet recording device)
In the transfer type inkjet recording apparatus, the recording medium is a transfer body that temporarily holds a first image and a second image in which the first liquid is absorbed from the first image. Further, the transfer type ink jet recording apparatus includes a transfer unit including a transfer pressing member for transferring the second image onto a recording medium on which the image is to be formed.

  1 and 2 are schematic diagrams illustrating an example of a schematic configuration of a transfer type inkjet recording apparatus according to the present embodiment.

  As shown in FIG. 1, the transfer type inkjet recording apparatus 100 according to the present embodiment includes a transfer body 101 supported by a support member 102, a reaction liquid applying device 103 that applies a reaction liquid onto the transfer body 101, and a reaction liquid. An ink applying device 104 for applying ink on the transfer body 101 to which ink is applied and forming an ink image (first image) on the transfer body, and liquid absorption for absorbing a liquid component from the first image on the transfer body The apparatus 105 includes a transfer pressing member 106 that transfers the second image on the transfer body from which the liquid component has been removed by pressing the recording medium onto a recording medium 108 such as paper. Further, the transfer type inkjet recording apparatus 100 may have a transfer body cleaning member 109 that cleans the surface of the transfer body 101 after the second image is transferred to the recording medium 108.

  FIG. 2 shows a transfer type ink jet recording apparatus 200 that is changed to a belt-shaped transfer body 201. The reaction liquid applying device 203, the ink applying device 204, the liquid absorbing device 205 that absorbs the liquid component contained in the first image, the transfer pressing member 206, and the conveying device 207 for the recording medium 208 are the same as those in FIG. The description is omitted.

  Note that the belt-shaped transfer body 201 is preferable because the heat capacity is less than that of the drum-shaped transfer body 101 and the temperature is easily controlled in the up and down direction. Reference numeral 210 denotes a counter roller that presses the transfer body 201 against the transfer pressing member 206 side. The facing roller 210 can also serve as the heating member 10. The transfer position is not limited to the position shown in FIG. 2, and the support member 202 facing the heating member 10 may be transferred as a counter roller. The rest of the configuration is substantially the same as that in FIG. 1, and therefore FIG. 1 will be described below.

  The support member 102 rotates in the direction of the arrow A in FIG. The transfer body 101 is moved by the rotation of the support member 102. On the transferred transfer body 101, the reaction liquid by the reaction liquid applying apparatus 103 and the ink by the ink applying apparatus 104 are sequentially applied, and a first image is formed on the transfer body 101. The first image formed on the transfer body 101 is moved to a position in contact with the liquid absorbing member 105 a included in the liquid absorbing device 105 by the movement of the transfer body 101.

  The liquid absorbing member 105 a of the liquid absorbing device 105 moves in synchronization with the rotation of the transfer body 101. The image formed on the transfer body 101 is in contact with the moving liquid absorbing member 105a. During this time, the liquid absorbing member 105a removes the liquid component from the image. The liquid component contained in the first image is removed through the state of contact with the liquid absorbing member 105a. In this state of contact, the liquid absorbing member 105a has the first pressing force with a predetermined pressing force. It is a preferable configuration that the liquid absorbing member 105a effectively functions to be pressed by the image.

  If the removal of the liquid component is described from a different point of view, it can also be expressed as concentrating the ink constituting the image formed on the transfer body. Concentrating the ink means that the content ratio of the solid component such as a coloring material or resin contained in the ink increases as the liquid component contained in the ink decreases.

  Then, the second image after the liquid component is removed is moved to the heating unit by the movement of the transfer body 101, and is heated by the heating member 10 there. The heated second image is moved to a transfer unit that comes into contact with the recording medium conveyed by the recording medium conveying device 107. While the heated second image is in contact with the recording medium 108, the pressing member 106 presses the recording medium, whereby an ink image is formed on the recording medium 108. The transferred ink image transferred onto the recording medium 108 is a reverse image of the second image. In the following description, this post-transfer ink image may be referred to as a third image separately from the first image (ink image before liquid removal) and the second image (ink image after liquid removal).

  Since an image is formed by applying ink after the reaction liquid is applied on the transfer body, the reaction liquid remains in the non-image area (non-ink image forming area) without reacting with the ink. . In this apparatus, the liquid absorbing member 105a is in contact (pressure contact) not only with the image but also with the unreacted reaction liquid, and the liquid components of the reaction liquid are also removed from the surface of the transfer body 101 together.

  Therefore, in the above, it is expressed and described that the liquid component is removed from the image, but this is not a limited meaning of removing the liquid component only from the image, and at least the liquid component is removed from the image on the transfer body. It is used in the sense that it should be. For example, it is also possible to remove the liquid component in the reaction solution applied to the outer region of the first image together with the first image. The liquid component is not particularly limited as long as it does not have a certain shape, has fluidity, and has a substantially constant volume. For example, water, an organic solvent, or the like contained in ink or a reaction liquid can be used as the liquid component.

  Even when the above-described clear ink is included in the first image, the ink can be concentrated by the liquid absorption process. For example, when the clear ink is applied on the color ink containing the color material applied on the transfer body 101, the clear ink exists entirely on the surface of the first image, or the first ink Clear ink is partially present at one or more locations on the surface of the image, and color ink is present at other locations. In the first image, where the clear ink is present on the color ink, the porous body absorbs the liquid component of the clear ink on the surface of the first image, and the liquid component of the clear ink moves. Along with this, the liquid component in the color ink moves to the porous body side, so that the aqueous liquid component in the color ink is absorbed.

  On the other hand, in the location where the clear ink and the color ink exist on the surface of the first image, the liquid components of the color ink and the clear ink move to the porous body side, and the liquid components are absorbed. The clear ink may contain many components for improving the transferability of the image from the transfer body 101 to the recording medium. For example, the content rate of the component which becomes more adhesive to the recording medium by heating than the color ink is increased.

  Each configuration of the transfer type inkjet recording apparatus of this embodiment will be described below.

<Transfer>
As described above, the transfer body 101 has an elastic layer between the surface layer and the compression layer, and the transfer body 101 in FIG. 1 has a drum shape supported by a support member 102 described below. .

<Supporting member>
The transfer body 101 is supported on a support member 102. Various adhesives and double-sided tapes may be used as a method for supporting the transfer body. Alternatively, the transfer member may be supported on the support member 102 using the installation member by attaching an installation member made of metal, ceramic, resin, or the like to the transfer member.

  The support member 102 is required to have a certain degree of structural strength from the viewpoint of conveyance accuracy and durability. For the material of the support member, metal, ceramic, resin or the like is preferably used. In particular, in addition to rigidity and dimensional accuracy that can withstand pressure during transfer, and to reduce control inertia and improve control responsiveness, aluminum, iron, stainless steel, acetal resin, epoxy resin, polyimide, Polyethylene, polyethylene terephthalate, nylon, polyurethane, silica ceramics, and alumina ceramics are preferably used. It is also preferable to use these in combination.

<Reaction solution applying apparatus>
The ink jet recording apparatus according to the present embodiment includes a reaction liquid applying device 103 that applies a reaction liquid to the transfer body 101. 1 is a gravure offset having a reaction solution storage unit 103a that stores a reaction solution, and reaction solution application members 103b and 103c that apply the reaction solution in the reaction solution storage unit 103a onto the transfer body 101. The case of a roller is shown.

<Ink application device>
The ink jet recording apparatus according to this embodiment includes an ink applying device 104 that applies ink to the transfer body 101 to which the reaction liquid is applied. The reaction liquid and the ink are mixed to form a first image, and the liquid component is absorbed from the first image by the next liquid absorption device 105.

<Liquid absorption device>
In the present embodiment, the liquid absorbing device 105 includes a liquid absorbing member 105 a and a liquid absorbing pressing member 105 b that presses the liquid absorbing member 105 a against the first image on the transfer body 101. In addition, there is no restriction | limiting in particular about the shape of the liquid absorption member 105a and the press member 105b. For example, as shown in FIG. 1, the pressing member 105b has a cylindrical shape, the liquid absorbing member 105a has a belt shape, and the belt-shaped liquid absorbing member 105a is pressed against the transfer body 101 by the cylindrical pressing member 105b. It may be a configuration. The pressing member 105b has a columnar shape, and the liquid absorbing member 105a has a cylindrical shape formed on the peripheral surface of the columnar pressing member 105b. The cylindrical pressing member 105b is a cylindrical liquid absorbing member 105a. May be configured to be pressed against the transfer body.

  In the present embodiment, the liquid absorbing member 105a is preferably belt-shaped in consideration of the space in the ink jet recording apparatus. Further, the liquid absorbing device 105 having such a belt-shaped liquid absorbing member 105a may have a stretching member that stretches the liquid absorbing member 105a. In FIG. 1, 105c, 105d, and 105e are tension rollers as tension members. In FIG. 1, the pressing member 105b is also a roller member that rotates in the same manner as the stretching roller, but is not limited to this.

  In the liquid absorbing device 105, the liquid absorbing member 105a having a porous body is pressed against the first image by the pressing member 105b so that the liquid component contained in the first image is absorbed by the liquid absorbing member 105a. A second image in which the liquid component is reduced from the image of.

  Hereinafter, various conditions and configurations in the liquid absorbing device 105 will be described in detail.

(Preprocessing)
In this embodiment, before the liquid absorbing member 105a having a porous body is brought into contact with the first image, preprocessing is performed by preprocessing means (not shown in FIGS. 1 and 2) for applying a wetting liquid to the liquid absorbing member. It is preferable to apply. The wetting liquid used in the present embodiment preferably contains water and a water-soluble organic solvent. The water is preferably water deionized by ion exchange or the like. The type of the water-soluble organic solvent is not particularly limited, and any known organic solvent such as ethanol or isopropyl alcohol can be used. In the pretreatment of the liquid absorbing member used in the present embodiment, the method for applying the wetting liquid to the porous body is not particularly limited, but immersion or droplet dropping is preferable.

(Pressure condition)
When the pressure of the liquid absorbing member that presses against the first image on the transfer body is 2.9 N / cm ² (0.3 kgf / cm ² ) or more, the liquid component in the first image is reduced in a shorter time. It is preferable because the liquid component can be removed from the first image. In addition, the pressure of the liquid absorbing member in this specification indicates the nip pressure between the transfer member and the liquid absorbing member, and the surface pressure is measured by a surface pressure distribution measuring instrument (I-SCAN manufactured by Nitta Co., Ltd.). Measurement is performed, and the weight in the pressurization region is divided by the area to calculate the value.

(Action time)
The working time for bringing the liquid absorbing member 105a into contact with the first image is preferably within 50 ms (milliseconds) in order to further suppress the coloring material in the first image from adhering to the liquid absorbing member. . The operation time in this specification is calculated by dividing the pressure sensing width in the moving direction of the transfer body in the surface pressure measurement described above by the moving speed of the transfer body. Hereinafter, this action time is referred to as a liquid absorption nip time.

  In this way, on the transfer body 101, the liquid component is absorbed from the first image, and a second image with a reduced liquid component is formed. The second image is then heated by the heating member 10 and transferred onto the recording medium 108 at the transfer portion.

  The apparatus configuration and conditions during transfer will be described.

<Heating member>
As the heating member 10 in the present embodiment, an infrared heater is used, and the surface temperature of the second image is measured by a non-contact temperature measuring device (not shown), and the heater is turned on / off so as to be a predetermined temperature. Adjust. 1 and 2, the heating member 10 is provided outside the transfer body. However, the heating member 10 may be heated at the same time as the transfer, such as a mode in which a heating means is included inside a transfer pressing member described later.

<Pressing member for transfer>
In the present embodiment, the transfer pressing member 106 presses the recording medium 108 while the second image after heating and the recording medium 108 conveyed by the recording medium conveying device 107 are in contact with each other. An ink image is transferred onto the recording medium 108. By removing the liquid component contained in the first image on the transfer body 101 and then transferring it to the recording medium 108, it is possible to obtain a recorded image in which curling, cockling, and the like are suppressed.

  The pressing member 106 is required to have a certain degree of structural strength from the viewpoint of conveyance accuracy and durability of the recording medium 108. The material of the pressing member 106 is preferably metal, ceramic, resin, or the like. In particular, in addition to rigidity and dimensional accuracy that can withstand pressure during transfer, and to reduce control inertia and improve control responsiveness, aluminum, iron, stainless steel, acetal resin, epoxy resin, polyimide, Polyethylene, polyethylene terephthalate, nylon, polyurethane, silica ceramics, and alumina ceramics are preferably used. Moreover, you may use combining these.

  There is no particular limitation on the time for the pressing member 106 to press the second image on the transfer body 101 to the recording medium 108, but the transfer is performed well and the durability of the transfer body is not impaired. Therefore, it is preferably 5 ms or more and 100 ms or less. The pressing time in this embodiment indicates the time during which the recording medium 108 and the transfer body 101 are in contact with each other, and the surface pressure is measured with a surface pressure distribution measuring instrument (I-SCAN manufactured by Nitta Corporation). The measurement is performed, and the length in the conveyance direction of the pressurizing region is divided by the conveyance speed to calculate a value.

Further, there is no particular limitation on the pressure that the pressing member 106 presses in order to transfer the second image on the transfer body 101 to the recording medium 108, but the transfer is performed well and the durability of the transfer body is impaired. Do not. For this, it is preferable that the pressure is less than ^{9.8N / cm 2 (1kg / cm} 2) or more ^{294.2N / cm 2 (30kg / cm} 2). The pressure in the present embodiment indicates the nip pressure between the recording medium 108 and the transfer body 101. The surface pressure is measured by a surface pressure distribution measuring device, and the weight in the pressurizing region is divided by the area to obtain a value. Is calculated.

  The temperature at which the pressing member 106 is pressed to transfer the second image on the transfer body 101 to the recording medium 108 is not particularly limited, but it is not less than the glass transition point of the resin component contained in the ink or softened. It is preferable that it is more than a point. In addition, it is preferable that the heating includes a heating member 10 that heats the second image on the transfer body 101, and a heating unit that heats the transfer body 101 and the recording medium 108. The shape of the pressing member 106 is not particularly limited, and examples thereof include a roller shape.

<Recording medium and recording medium conveying apparatus>
In the present embodiment, the recording medium 108 is not particularly limited, and any known recording medium can be used. Examples of the recording medium include a long product wound in a roll shape, or a single sheet cut into a predetermined size. Examples of the material include paper, plastic film, wood board, cardboard, and metal film. In FIG. 1, the recording medium conveying device 107 for conveying the recording medium 108 is constituted by a recording medium feeding roller 107a and a recording medium take-up roller 107b. It is not limited to.

<Cooling of transfer body>
In this embodiment, in order to repeatedly perform image formation, liquid absorption, and transfer, it is preferable to have a cooling member 11 that cools the transfer body 101 after transfer. After the transfer step and before the step of forming the first image, the transfer member is cooled by the cooling member, and then the liquid is removed after the step of forming the first image again. It is possible to suppress the evaporation of the liquid component from the image during the process. The cooling is controlled so that the image is lower than the boiling point of water in the ink at the timing when the liquid removing step is performed. Further, it is more preferable that the ink is applied at a timing lower than the boiling point of water in the ink. Further, in FIG. 1, the cooling process is provided after the transfer process, but it may be provided after the ink application process. Although not shown, it is also preferable to provide a plurality of cooling steps.

  Moreover, it is preferable to cool the temperature of the transfer body to less than the cloud point of the surfactant contained in the reaction solution. In the step of applying the reaction solution, the temperature of the transfer body is lower than the cloud point, so that the activity of the surfactant contained in the reaction solution is maintained, the wettability of the reaction solution is sufficiently high, and the image is more aggregated. It is estimated that power will increase. It is considered that the transferability is improved by increasing the cohesive force of the image. In the present invention, the cloud point of the surfactant can be measured by heating a 1% by weight aqueous solution of the surfactant.

  As a cooling method, a known method such as a method of blowing cold air, a method of bringing a cooled roller into contact, a method of applying a cooled liquid, a method using heat of vaporization, or the like can be used. In particular, in order to cool at high speed, it is preferable to use a method in which a solid or a liquid is brought into contact with the transfer body. These solids and liquids are those that are cooled below the boiling point of water. Further, it is also preferable to combine air blowing or the like. As a method of bringing the liquid into contact, the liquid may be directly applied, or the liquid may be included in contact with the porous body. In addition, by cooling the liquid absorbing member 105a, it is possible to more reliably suppress evaporation of the liquid component in the first image and prevent poor absorption even in the liquid removing step.

<Cleaning member>
In the present embodiment, a cleaning member 109 that cleans an image remaining on a transfer body after transfer, paper dust transferred from a recording medium, or the like may be used. For cleaning, a known method such as a method of contacting a porous member, a method of rubbing with a brush, or a method of scraping with a blade can be appropriately used. Moreover, the shape of a member can use well-known shapes, such as a roller shape and a web shape. In the present invention, it is also preferable to serve as the above-described cooling member by cooling the temperature of the cleaning member.

<Control system>
The transfer type inkjet recording apparatus in the present embodiment has a control system that controls each apparatus. FIG. 3 is a block diagram showing a control system of the entire apparatus in the transfer type ink jet recording apparatus shown in FIG.

  In FIG. 3, 301 is a recording data generation unit such as an external print server, 302 is an operation control unit such as an operation panel, 303 is a printer control unit for executing a recording process, and 304 is a recording medium for conveying the recording medium. A conveyance control unit 305 is an inkjet device for printing.

  FIG. 4 is a block diagram of a printer control unit in the transfer type inkjet recording apparatus of FIG. A CPU 401 controls the entire printer, a ROM 402 stores a control program for the CPU, and a RAM 403 executes the program. An ASIC 404 includes a network controller, a serial IF controller, a head data generation controller, a motor controller, and the like. Reference numeral 405 denotes a liquid absorption member conveyance control unit for driving the liquid absorption member conveyance motor 406, and is command-controlled from the ASIC 404 via the serial IF. Reference numeral 407 denotes a transfer body drive control unit for driving the transfer body drive motor 408. Similarly, command control is performed from the ASIC 404 via the serial IF. Reference numeral 409 denotes a head controller that performs final ejection data generation, drive voltage generation, and the like of the inkjet device 305. A transfer body temperature control unit 410 controls the temperature of the heating member 10 and the cooling member 11.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples as long as the gist thereof is not exceeded. In the description of the following examples, “part” is based on mass unless otherwise specified.

In this example, the transfer type ink jet recording apparatus shown in FIG. 1 was used.
The transfer body 101 in this embodiment is fixed to the support member 102 with an adhesive. In this example, a sheet obtained by coating a PET sheet having a thickness of 0.5 mm with a silicone rubber (KE12 manufactured by Shin-Etsu Chemical Co., Ltd.) to a thickness of 0.3 mm was used as the elastic layer of the transfer body J. Further, glycidoxypropyltriethoxysilane and methyltriethoxysilane were mixed at a molar ratio of 1: 1 to prepare a mixture of a condensate obtained by heating under reflux and a photocationic polymerization initiator (SP150 manufactured by ADEKA). The atmospheric pressure plasma treatment is performed so that the contact angle of water on the elastic layer surface is 10 degrees or less, the mixture is applied onto the elastic layer, UV irradiation (high pressure mercury lamp, accumulated exposure 5000 mJ / cm ² ), heat The transfer body 101 was formed by curing (150 ° C. for 2 hours) to form a surface layer having a thickness of 0.5 μm on the elastic body. In this configuration, although illustration is omitted for simplicity of explanation, a double-sided tape is used to hold the transfer body 101 between the transfer body 101 and the support member 102.

The reaction liquid applied by the reaction liquid application device 103 was of the following composition, and the application amount was 1 g / m ² . The cloud point of the surfactant in the following reaction solution was 50 ° C. In addition, the cloud point of surfactant was measured by heating 1 mass% aqueous solution of surfactant.
・ Glutaric acid 21.0 parts ・ Potassium hydroxide 2.0 parts ・ Glycerin 5.0 parts ・ Surfactant (product name: TF-2066, manufactured by DIC Corporation) 5.0 parts ・ Ion-exchanged water remaining

  The ink was prepared as follows.

<Preparation of pigment dispersion>
10 parts of carbon black (product name: Monac 1100, manufactured by Cabot), aqueous resin solution 1 (styrene-ethyl acrylate-acrylic acid copolymer, acid value 150, weight average molecular weight (Mw) 8,000, resin content is 15 parts of a 20.0% by weight aqueous solution neutralized with a potassium hydroxide aqueous solution) and 75 parts of pure water were mixed and charged into a batch type vertical sand mill (manufactured by IMEX). The dispersion treatment was carried out for 5 hours while partly filling and cooling with water. This dispersion was centrifuged to remove coarse particles, and then a black pigment dispersion having a pigment content of 10.0% by mass was obtained.

<Preparation of resin fine particle dispersion>
(Preparation of resin fine particle dispersion 1)
Ethyl methacrylate 18%, 2,2′-azobis- (2-methylbutyronitrile) 2%, and n-hexadecane 2% were mixed and stirred for 0.5 hour. This mixture was added dropwise to a 6% aqueous solution (mixing ratio 78%) of “NIKKOL BC15” (trade name, manufactured by Nikko Chemicals), which is an emulsifier, and stirred for 0.5 hour. Next, the ultrasonic wave was irradiated for 3 hours with the ultrasonic irradiation machine. Subsequently, a polymerization reaction was performed in a nitrogen atmosphere at 80 ° C. for 4 hours, followed by cooling after room temperature cooling to prepare resin fine particle dispersion 1 having a resin content of 25.0% by mass.

<Preparation of ink 1>
The resin fine particle dispersion 1 and the pigment dispersion obtained above were mixed with the following components to prepare ink 1. The balance of ion-exchanged water is such that the total of all components constituting the ink is 100.0% by mass.

Pigment dispersion (coloring material content is 10.0% by mass) 40.0% by mass
・ Resin fine particle dispersion 1 20.0 mass%
・ Glycerin 7.0% by mass
Polyethylene glycol (number average molecular weight (Mn): 1,000) 3.0% by mass
・ Surfactant 0.5% by mass
(Product name: Acetylenol E100, manufactured by Kawaken Fine Chemical Co., Ltd.)
・ Ion exchange water balance

  After sufficiently stirring and dispersing this, pressure filtration was performed with a microfilter (manufactured by Fuji Film Co., Ltd.) having a pore size of 3.0 μm to prepare ink 1. The minimum film forming temperature (MFT) of this ink 1 was 100 ° C. For the measurement of the minimum film-forming temperature (MFT), the temperature at which a film was formed was evaluated using a sample after the ink was dried at room temperature for 24 hours.

<Preparation of ink 2>
A mixture was obtained by premixing 10 parts of polyethylene wax (trade name “High Wax 100P”, manufactured by Mitsui Chemicals, Inc.), 125 parts of the aqueous resin solution 1, and 65 parts of ion-exchanged water with a homomixer for 0.5 hours. The obtained mixture was passed three times through a high-pressure homogenizer (trade name “Nanovaita”, manufactured by Yoshida Kikai Kogyo Co., Ltd.) heated to 120 ° C. with a heating option to obtain wax particle dispersion 1. The volume average dispersed particle size of the wax measured using a dynamic light scattering type particle size distribution measuring device (trade name “Microtrack UPA EX-150”, manufactured by Nikkiso) was 120 nm.

The following ink 2 was prepared using the wax particle dispersion 1 in the same manner as the ink 1.
(Ink 2)
Pigment dispersion (coloring material content is 10.0% by mass) 40.0% by mass
・ Resin fine particle dispersion 1 15.0 mass%
-Wax particle dispersion 1 5.0% by mass
・ Glycerin 7.0% by mass
Polyethylene glycol (number average molecular weight (Mn): 1,000) 3.0% by mass
・ Surfactant 0.5% by mass
(Product name: Acetylenol E100, manufactured by Kawaken Fine Chemical Co., Ltd.)
-Ion exchange water remainder The minimum film forming temperature (MFT) of the ink 2 was 110 degreeC.

<Preparation of ink 3>
(Preparation of resin fine particle dispersion 2)
Butyl methacrylate 18%, 2,2′-azobis- (2-methylbutyronitrile) 2%, n-hexadecane 2% were mixed and stirred for 0.5 hour. This mixture was added dropwise to a 6% aqueous solution (mixing ratio 78%) of “NIKKOL BC15” (trade name, manufactured by Nikko Chemicals), which is an emulsifier, and stirred for 0.5 hour. Next, the ultrasonic wave was irradiated for 3 hours with the ultrasonic irradiation machine. Subsequently, a polymerization reaction was performed in a nitrogen atmosphere at 80 ° C. for 4 hours, followed by cooling after room temperature cooling to prepare resin fine particle dispersion 2 having a resin content of 25.0% by mass.

  The resin fine particle dispersion 2 and the pigment dispersion obtained above were mixed with the following components to prepare ink 3. The balance of ion-exchanged water is such that the total of all components constituting the ink is 100.0% by mass.

Pigment dispersion (coloring material content is 10.0% by mass) 40.0% by mass
・ Resin fine particle dispersion 2 20.0 mass%
・ Glycerin 7.0% by mass
Polyethylene glycol (number average molecular weight (Mn): 1,000) 3.0% by mass
・ Surfactant 0.5% by mass
(Product name: Acetylenol E100, manufactured by Kawaken Fine Chemical Co., Ltd.)
・ Ion exchange water balance

  After sufficiently stirring and dispersing, ink 3 was prepared by performing pressure filtration with a micro filter (manufactured by Fuji Film Co., Ltd.) having a pore size of 3.0 μm. The minimum film forming temperature (MFT) of this ink 3 was 50 ° C.

The ink applying device 104 uses an ink jet head that discharges ink by an on-demand method using an electro-thermal conversion element, and the ink applying amount is 20 g / m ² . The liquid absorbing member 105a is adjusted to have a speed equivalent to the moving speed of the transfer body 101 by conveying rollers 105c, 105d, and 105e that convey the liquid absorbing member while stretching it. Further, the recording medium 108 is conveyed by the recording medium feeding roller 107a and the recording medium take-up roller 107b so that the speed is equal to the moving speed of the transfer body 101. In this example, the conveyance speed was 0.1 m / s, and aurora-coated paper (manufactured by Nippon Paper Industries Co., Ltd., basis weight 104 g / m ² ) was used as the recording medium 108. The image on the transfer body was transferred to a recording medium at a pressure of 29.4 N / cm ² (3 kg / cm ² ).

The nip pressure between the transfer member 101 and the liquid absorbing member 105a is applied to the liquid absorbing member 105b so that the average pressure is 29.4 N / cm ² (3 kg / cm ² ). Further, the pressing member 105b in the liquid absorbing device 105 has a roller diameter of 400 mm. As the liquid absorbing member 105a, hydrophilic PTFE having an average pore diameter of 0.2 μm was used. The absorbing member had a galee of 8 seconds.

  Further, an infrared heater manufactured by Heraeus Co., Ltd. was used as the heating member 10. The image heating temperature was controlled by changing the input voltage to the infrared heater. Further, as the cooling member 11, a system in which a non-woven fabric (HOP60 manufactured by Hirose Paper Co., Ltd.) containing water cooled by a chiller (not shown) was brought into contact with the transfer body was used. The cooling temperature of the transfer member was controlled by controlling the cooling temperature of the water to be included. By combining the inks 1 to 3 and the control states of the heating member and the cooling member, the image transferability and absorption performance were evaluated under the conditions shown in Table 1 below. In Example 4, the liquid absorbing member was controlled to be cooled to less than 70 ° C. compared to Example 1. In Table 1, “the boiling point of the ink main solvent” means “the boiling point of water in the ink”, and “the minimum film forming temperature of the image” is “the minimum film forming temperature of the second image”. That is. Also, “printing to liquid removal temperature” means “the temperature of the first image between the first image forming step (ink applying step) and before the liquid removing step”. is there. In this example, since the reaction solution does not contain a component that affects the minimum film-forming temperature of the second image, such as a film-forming aid, the minimum film-forming temperature of the ink is set to the second image. The minimum film-forming temperature was determined.

  Table 2 shows the evaluation results evaluated under the conditions shown in Table 1 above. In the present invention, the evaluation criteria A to B of the following evaluation items were set to acceptable levels, and C was set to an unacceptable level.

<Transferability>
The transfer amount by the transfer process under the above-described conditions is shown. It is preferable that the transfer amount is large (the number of non-transfer areas is small), and the evaluation criteria are as follows.
A: Almost no image area to be transferred was observed.
B: Although there was a slight image area that was not transferred, it was at a level with no practical problem.
C: The image area which is not transferred was large, which was a problem in practical use.

<Robustness>
The liquid removability on the transfer body and the image fastness depending on the MFT of the image are shown. When the amount of the remaining liquid is large, the fastness of the image may be lowered. Therefore, it is preferable that the remaining liquid amount is small. The robustness of the image is also affected by the MFT of the image. The evaluation criteria are as follows. The image on the recording medium produced under the conditions described above was cut into a 25 mm-wide strip and cut into a strip using an abrasion resistance tester (manufactured by Imoto Seisakusho Co., Ltd.), which is a Gakushin type testing machine. The same printing paper was placed on the printed material and the scraper, and a friction test was performed with a load of 500 g and 200 times to evaluate the scratching property.

In addition, since the evaluation of transferability evaluation C was impossible, it was set as no evaluation (-).
A: No scratch mark is observed.
B: A slight scratch mark was observed, but it was a level with no practical problem.
C: Large scratch marks were observed.

DESCRIPTION OF SYMBOLS 10 Heating member 11 Cooling member 100, 200 Transfer type inkjet recording device 101, 201 Transfer body 102, 202 Support member 102a Rotating shaft 103, 203 of reaction member Reaction solution applying device 103a, 203a Reaction solution storage portion 103b, c, 203b, c Reaction liquid applying member 104, 204 Ink applying device 105, 205 Liquid absorbing device 105a, 205a Liquid absorbing member 105b, 205b Press member 105c, d, e, 205c, d, e Stretch roller 106, 206 Transfer pressing member 107, 207 Recording medium conveying device 107a, 207a Recording medium feeding roller 107b, 207b Recording medium winding roller 108, 208 Recording medium 109, 209 Transfer member cleaning member 210 Opposing roller 301 Recording data generation unit 302 Operation control unit 303 Printer control 304 recording medium conveyance control unit 305 inkjet device 401 CPU
402 ROM
403 RAM
404 ASIC
405 Liquid absorbing member transport control unit 406 Liquid absorbing member transport motor 407 Transfer body drive control unit 408 Transfer body drive motor 409 Head control unit 410 Transfer body temperature control unit

Claims (14)

A water-soluble organic solvent having a boiling point higher than that of water and water by passing through a step of applying a reaction liquid containing an ink thickening component and a step of applying an ink containing water and a coloring material on the transfer body; Forming a first image comprising: a liquid component containing a solid component insoluble in the liquid component formed by mixing the reaction liquid and the ink;
A liquid removal step of bringing a porous body into contact with the transfer body on which the first image is formed, and forming a second image in which a part of the liquid component contained in the first image is removed; and
A transfer step in which the second image is heated to a temperature equal to or higher than the minimum film-forming temperature of the second image and transferred onto a recording medium;
Is an ink jet recording method for repeatedly performing on the transfer body,
The minimum film-forming temperature of the second image is a temperature of 100 ° C. or higher,
The inkjet recording method according to claim 1, wherein the first image does not receive a thermal history higher than a boiling point of water between the step of forming the first image and the step of removing the liquid.   2. The ink jet recording method according to claim 1, wherein the first image includes a water-soluble organic solvent having a boiling point higher than that of water and 3% by mass or more of the entire image, and includes more of the water than the water-soluble organic solvent.   3. The ink jet recording method according to claim 1, further comprising a cooling step of cooling the transfer body below the boiling point of water before the liquid removing step. 4.   4. The inkjet according to claim 3, further comprising a cooling step of cooling the transfer body below the boiling point of water between the transfer step and before the step of forming the first image. Recording method.   5. The ink jet recording method according to claim 3, wherein the cooling step is a step of bringing a solid or a liquid into contact with the transfer body.   The ink jet recording method according to claim 1, wherein the ink includes wax particles.   The reaction solution contains a surfactant, and has a cooling step for cooling the transfer body to less than the cloud point of the surfactant after the transfer step and before the step of applying the reaction solution. The ink jet recording method according to claim 3, wherein the ink jet recording method is performed.   The inkjet recording method according to claim 1, wherein the porous body is cooled to a temperature lower than that of the first image.   The inkjet recording method according to claim 3, further comprising a cleaning step of cleaning the transfer body after the transfer step, wherein the cleaning step and the cooling step are performed simultaneously.   The maximum temperature of the first image after the step of forming the first image and before the step of removing the liquid is 30 ° C. or more lower than the boiling point of water. The inkjet recording method according to any one of 1 to 9. The amount of the water-soluble organic solvent having a boiling point higher than that of the water in the second image immediately after the second image formation is 0.9 g / m ² or less. The inkjet recording method as described.   The inkjet recording method according to claim 1, wherein the transfer body is a drum-shaped transfer body.   The inkjet recording method according to claim 1, wherein the transfer body is a belt-shaped transfer body. A water-soluble organic solvent having a boiling point higher than that of water and water by passing through a step of applying a reaction liquid containing an ink thickening component and a step of applying an ink containing water and a coloring material on the transfer body; Forming a first image comprising: a liquid component containing a solid component insoluble in the liquid component formed by mixing the reaction liquid and the ink;
A liquid removing step of bringing a porous body into contact with the transfer body on which the first image is formed, and concentrating ink constituting the first image to form a second image;
A transfer step in which the second image is heated to a temperature equal to or higher than the minimum film-forming temperature of the second image and transferred onto a recording medium;
Is an ink jet recording method for repeatedly performing on the transfer body,
The minimum film-forming temperature of the second image is a temperature of 100 ° C. or higher,
The inkjet recording method according to claim 1, wherein the first image does not receive a thermal history higher than a boiling point of water between the step of forming the first image and the step of removing the liquid.

Images