JP6838973B2 - Method for manufacturing an inkjet recording device and a porous body - Google Patents

Description

The present invention relates to an inkjet recording device and a method for producing a porous body used in the inkjet recording device.

In the inkjet recording method, an image is formed by directly or indirectly applying a liquid composition (ink) containing a coloring material onto a recording medium such as paper. At this time, curling or cockling may occur due to excessive absorption of the liquid component in the ink by the recording medium.

Therefore, in order to quickly remove the liquid component in the ink, the recording medium is dried by means such as warm air or infrared rays, or an image is formed on the transfer body and then included in the image on the transfer body. There is a method of transferring an image to a recording medium such as paper after removing a liquid component by heat energy or the like.

Further, as a means for removing the liquid component contained in the image on the transfer body, a method in which a roller-shaped porous body is brought into contact with the ink image to absorb and remove the liquid component from the ink image without using thermal energy. Have been proposed (Patent Documents 1 and 2). Further, a method has been proposed in which a belt-shaped polymer absorber is brought into contact with an ink image to absorb and remove a liquid component from the ink image (Patent Document 3).

JP-A-2009-45551 Japanese Unexamined Patent Publication No. 2005-161610 Japanese Unexamined Patent Publication No. 2001-179959

However, in the methods described in Patent Documents 1 to 3, when the liquid component is absorbed and removed from the ink image on the transfer body, a part of the liquid, the coloring material, the solid content other than the coloring material, etc. in the ink is removed. A so-called "image flow" that is swept toward the rear end side of the image occurs. Further, when a member that absorbs and removes a liquid component for the purpose of improving the absorbability of the liquid component is composed of a plurality of layers, the interface between the layers may be peeled off when the member is conveyed. Therefore, an object of the present invention is to provide an inkjet recording device provided with a liquid absorbing member having a high transport strength and suppressed image flow, and a method for producing a porous body used in the inkjet recording device.

The inkjet recording apparatus according to the first aspect of the present invention comes into contact with an image forming unit that forms a first image containing a first liquid and a coloring material on a recording body and the first image. An inkjet recording apparatus comprising a liquid absorbing member having a porous body that absorbs at least a part of the first liquid from the first image, wherein the porous body comes into contact with the first image. The first layer, the second layer containing the second fiber, and the third layer containing the third fiber are laminated in this order, and the first layer, the second layer, and the second layer are laminated in this order. The layer and the third layer are both porous layers, and the average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber. The fiber has a core-sheath structure having a core structure forming the central axis and a sheath structure wrapping the core structure, and the softening temperature of the material forming the sheath structure forms the core structure. The average thickness of the sheath structure is lower than any of the softening temperature of the material, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber, and the average thickness of the sheath structure is that of the first layer. It is characterized by being smaller than the thickness.

The inkjet recording apparatus according to the second aspect of the present invention comes into contact with an image forming unit that forms a first image containing a first liquid and a coloring material on a recorded body and the first image. An inkjet recording apparatus comprising a liquid absorbing member having a porous body that absorbs at least a part of the first liquid from the first image, wherein the porous body comes into contact with the first image. The first layer, the second layer a containing the second fiber a, the second layer b containing the second fiber b, and the third layer containing the third fiber are in this order. The second layer is a porous sheet in which the first layer, the second layer a, the second layer b, and the third layer are all porous layers. The average fiber diameter of the fiber b is larger than the average fiber diameter of the third fiber, and the second fiber a and the second fiber b enclose the core structure forming the central axis and the core structure. It has a core-sheath structure having a sheath structure, and the softening temperature of the material forming the sheath structure of the second fiber a is the softening temperature of the material forming the core structure of the second fiber a and the softening temperature of the material. The softening temperature of the material forming the sheath structure of the second fiber b, which is lower than any of the softening temperatures of the material forming the first layer, is lower than any of the softening temperatures of the material forming the core structure of the second fiber b. It is characterized in that it is lower than both the softening temperature and the softening temperature of the material forming the third fiber, and the average thickness of the sheath structure of the second fiber a is smaller than the thickness of the first layer.
The inkjet recording apparatus according to the third aspect of the present invention includes an image forming unit that forms a first image by applying ink containing a first liquid and a coloring material onto a recording object, and the first image-forming unit. An inkjet recording apparatus comprising a liquid absorbing member having a porous body that comes into contact with an image and concentrates ink constituting the first image, wherein the porous body comes into contact with the first image. The first layer, the second layer containing the second fiber, and the third layer containing the third fiber are laminated in this order, and the first layer and the second layer are laminated in this order. , And the third layer is a porous sheet which is a porous layer, and the average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber, and the second fiber However, it has a core-sheath structure having a core structure forming the central axis and a sheath structure wrapping the core structure, and the softening temperature of the material forming the sheath structure is the material forming the core structure. The average thickness of the sheath structure is lower than any of the softening temperature of the material forming the first layer, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber, and the average thickness of the sheath structure is the thickness of the first layer. It is characterized by being smaller than.

The method for producing a porous body used in the inkjet recording apparatus according to the fourth aspect of the present invention includes an image forming unit that forms a first image containing a first liquid and a coloring material on the recorded body. Production of a porous body used in an inkjet recording apparatus, comprising a liquid absorbing member having a porous body that comes into contact with the first image and absorbs at least a part of the first liquid from the first image. In the method, the first layer in contact with the first image, the second layer containing the second fiber, and the third layer containing the third fiber are laminated in this order. By heating, there is a step of forming a porous body having the first layer, the second layer, and the third layer, and the first layer, the second layer, And the third layer is a porous layer, the average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber, and the second fiber forms a central axis. It has a core-sheath structure having a core structure to be formed and a sheath structure wrapping the core structure, and the softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure. The heating temperature is lower than both the softening temperature of the material forming the first layer and the softening temperature of the material forming the third fiber, and the average thickness of the sheath structure is smaller than the thickness of the first layer. Is equal to or higher than the softening temperature of the material forming the sheath structure, and the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the third fiber. It is characterized in that it is below the softening temperature of the material forming the above.

The method for producing a porous body used in the inkjet recording apparatus according to the fifth aspect of the present invention includes an image forming unit that forms a first image containing a first liquid and a coloring material on the recorded body. Production of a porous body used in an inkjet recording apparatus, comprising a liquid absorbing member having a porous body that comes into contact with the first image and absorbs at least a part of the first liquid from the first image. The method comprises a first layer in contact with the first image, a second layer a containing a second fiber a, a second layer b containing a second fiber b, and a third. By heating the third layer containing fibers in this order, the first layer, the second layer a, the second layer b, and the third layer can be obtained. The first layer, the second layer a, the second layer b, and the third layer are all porous layers, and the first layer, the second layer a, the second layer b, and the third layer are all porous layers. A core structure in which the average fiber diameter of the second fiber b is larger than the average fiber diameter of the third fiber, and the second fiber a and the second fiber b form a central axis, and the core structure. It has a core-sheath structure having a sheath structure, and the softening temperature of the material forming the sheath structure of the second fiber a is the softening of the material forming the core structure of the second fiber a. The softening temperature of the material forming the sheath structure of the second fiber b, which is lower than both the temperature and the softening temperature of the material forming the first layer, forms the core structure of the second fiber b. The average thickness of the sheath structure of the second fiber a is smaller than the thickness of the first layer, which is lower than both the softening temperature of the material and the softening temperature of the material forming the third fiber. The temperature is equal to or higher than the softening temperature of the material forming the sheath structure of the second fiber a and the second fiber b, and the core structure of the second fiber a and the second fiber b is formed. It is characterized by being equal to or lower than the softening temperature of the material to be formed, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an inkjet recording device provided with a liquid absorbing member having a high transport strength in which image flow is suppressed, and a method for producing a porous body used in the inkjet recording device.

It is a schematic diagram which shows an example of the structure of the transfer type inkjet recording apparatus in one Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the direct drawing type inkjet recording apparatus in one Embodiment of this invention. It is a block diagram which shows the control system of the whole apparatus in the inkjet recording apparatus shown in FIGS. 1 and 2. It is a block diagram of the printer control part in the transfer type inkjet recording apparatus shown in FIG. It is a block diagram of the printer control part in the direct drawing type inkjet recording apparatus shown in FIG. It is sectional drawing which shows an example of the porous body which concerns on 1st Embodiment. It is an enlarged cross-sectional view of a part of an example of a porous body. It is sectional drawing which shows an example of the porous body which concerns on 2nd Embodiment. It is a schematic diagram which shows an example of the laminator which can be used for the production of the porous body which concerns on this invention.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments.

The inkjet recording apparatus of the present invention comes into contact with an image forming unit that forms a first image containing a first liquid and a coloring material on a recording object and the first image, and from the first image. It includes a liquid absorbing member having a porous body that absorbs at least a part of the first liquid. By contacting the liquid absorbing member having the porous body with the first image containing the first liquid and the coloring material on the recorded body, at least a part of the first liquid is removed from the first image. To. As a result, curling and cockling due to excessive absorption of the first liquid in the first image by a recording medium such as paper are suppressed. It is not necessary to absorb all the first liquid.

In the inkjet recording apparatus of the present invention, the porous body comes into contact with the first image, the first layer containing the second fiber, the second layer containing the second fiber, and the third layer containing the third fiber. And are laminated in this order, and the first layer, the second layer, and the third layer are all porous layers. The average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber. The second fiber has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure. The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. Lower than either. The average thickness of the sheath structure is smaller than the thickness of the first layer. By satisfying these requirements, the blinding of the first and second layers is prevented, and the adhesive strength between the second layer and the third layer is improved, so that the image flow is suppressed and high. It is presumed that an inkjet recording apparatus including a liquid absorbing member having a conveying strength can be provided.

Further, in the other inkjet recording apparatus of the present invention, the first layer in which the porous body comes into contact with the first image, the second layer a containing the second fiber a, and the second fiber. The second layer b containing b and the third layer containing third fibers are laminated in this order, and the first layer, the second layer a, and the second layer b are laminated in this order. , And the third layer is a porous sheet, which is a porous layer. The average fiber diameter of the second fiber b is larger than the average fiber diameter of the third fiber. The second fiber a and the second fiber b have a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure. The softening temperature of the material forming the sheath structure of the second fiber a is higher than the softening temperature of the material forming the core structure of the second fiber a or the softening temperature of the material forming the first layer. Is also low. The softening temperature of the material forming the sheath structure of the second fiber b is higher than the softening temperature of the material forming the core structure of the second fiber b or the softening temperature of the material forming the third fiber. Is also low. The average thickness of the sheath structure of the second fiber a is smaller than the thickness of the first layer. By satisfying these requirements, the above-mentioned effects can be obtained, and at the same time, the surface irregularities on the first layer side of the second layer can be suppressed, the first layer can be prevented from being crushed, and the second layer and the first layer can be prevented from being crushed. It is possible to easily achieve both improvement in adhesive strength with the three layers. As a result, it is presumed that it is possible to provide an inkjet recording apparatus including a liquid absorbing member having a suppressed image flow and a high transport strength.

The method for producing a porous body used in the inkjet recording apparatus of the present invention includes a first layer in contact with the first image, a second layer containing a second fiber, and a third fiber. By heating the third layer in a laminated state in this order, there is a step of forming a porous body having the first layer, the second layer, and the third layer. Further, the first layer, the second layer, and the third layer are all porous layers. The heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure, the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the third. It is below the softening temperature of the material that forms the fibers of. According to the method, the inkjet recording apparatus of the present invention can be suitably manufactured.

The method for producing a porous body used in the other inkjet recording apparatus of the present invention includes a first layer in contact with the first image, a second layer a containing a second fiber a, and a second layer a. By heating the second layer b containing the fibers b and the third layer containing the third fibers in this order, the first layer and the second layer a can be obtained. It has a step of forming a porous body having the second layer b and the third layer. Further, the first layer, the second layer a, the second layer b, and the third layer are all porous layers. The heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure of the second fiber a and the second fiber b, and the core of the second fiber a and the second fiber b. It is equal to or lower than the softening temperature of the material forming the structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. According to the method, the other inkjet recording apparatus of the present invention can be suitably manufactured.

In the inkjet recording apparatus of the present invention, the image forming unit is not particularly limited as long as it can form a first image containing the first liquid and the coloring material on the object to be recorded. Preferably, 1) an apparatus for applying a first liquid composition containing the first liquid or the second liquid and an ink thickening component onto the recorded object, and 2) the first liquid. Alternatively, the first liquid composition comprises a second liquid and a device for applying the second liquid composition containing the coloring material onto the recorded object as a mixture of the first and second liquid compositions. It forms the image of. Usually, the second liquid composition is an ink containing a coloring material, and the device for applying the second liquid composition onto the recorded object is an inkjet recording device. In addition, the first liquid composition chemically or physically acts with the second liquid composition to obtain a mixture of the first and second liquid compositions into the first and second liquid compositions. Contains components that are more viscous than each of the above (ink high viscosity components). At least one of the first and second liquid compositions comprises the first liquid. Here, the first liquid includes a liquid having low volatility at room temperature (room temperature), and particularly includes water. The second liquid is a liquid other than the first liquid, and the volatility is not limited, but it is preferably a liquid having a higher volatility than the first liquid. The arrangement of the device for applying the first liquid composition to the recorded object and the device for applying the second liquid composition to the recorded object is not particularly limited, but from the viewpoint of improving the image quality of the image to be recorded. A step of applying the first liquid composition to the recording body and a step of applying the second liquid composition to the recorded body so as to overlap at least a part of the region to which the first liquid composition is applied. It is preferable to go through in this order. Therefore, the device for applying the first liquid composition to the recorded body and the device for applying the second liquid composition to the recorded body apply the first liquid composition to the recorded body, and the device is said to be used. It is preferable that the second liquid composition is arranged so that the second liquid composition can be applied so as to overlap at least a part of the region to which the first liquid composition is applied. Hereinafter, the first liquid composition is referred to as a “reaction liquid”, and an apparatus for applying the first liquid composition onto the recorded object is referred to as a “reaction liquid applying apparatus”. Further, the second liquid composition is referred to as "ink", and the device for applying the second liquid composition to the recorded object is referred to as an "ink applying device". Further, the first image refers to an ink image before liquid removal before being subjected to a liquid absorption treatment by a liquid absorption member. The ink image after liquid removal in which the content of the first liquid is reduced by performing the liquid absorption treatment is referred to as a second image. Further, 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.

<Reaction solution applying device>
The reaction solution applying device may be any device capable of applying the reaction solution onto the recorded object, and various conventionally known devices can be appropriately used. Specific examples thereof include a gravure offset roller, an inkjet head, a die coating device (die coater), and a blade coating device (blade coater). The reaction solution may be applied by the reaction solution application device before the ink is applied or after the ink is applied, as long as it can be mixed (reacted) with the ink on the recording object. Preferably, the reaction solution is applied before applying the ink. By applying the reaction solution before applying the ink, bleeding in which the adjacently applied inks are mixed with each other during image recording by the inkjet method, and bee in which the ink that has landed first is attracted to the ink that has landed later. It is also possible to suppress the ding.

<Reaction solution>
The reaction solution contains a component that increases the viscosity of the ink (ink high viscosity component). Here, the high viscosity of the ink means that the coloring material, resin, etc., which are the components constituting the ink, chemically react or physically adsorb when they come into contact with the high viscosity component of the ink. This means that an increase in ink viscosity is observed. This increase in viscosity of the ink is not limited to the case where an increase in the viscosity of the ink is observed, but also the case where a part of the components constituting the ink such as a coloring material or a resin aggregates to cause a local increase in the viscosity. included. This ink high viscosity component reduces the fluidity of the ink and / or a part of the components constituting the ink on the recording object, and suppresses bleeding and beading during the first image formation. effective. In the present invention, increasing the viscosity of the ink is also referred to as "making the ink viscous". As such an ink high viscosity component, known substances 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 preferable. It is also preferable to contain a plurality of types of ink high viscosity components. The content of the ink high viscosity component in the reaction solution is preferably 5% by mass or more with respect to the total mass of the reaction solution.

Examples of the polyvalent metal ion 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+, etc. Trivalent metal ions of.

Examples of organic acids include oxalic acid, polyacrylic acid, formic acid, acetic acid, propionic acid, glycolic acid, malonic acid, malonic acid, maleic acid, ascorbic acid, levulinic acid, succinic acid, glutaric acid, glutamic acid, and fumal. Examples thereof include acids, citric acid, tartrate acid, lactic acid, pyrrolidone carboxylic acid, pyroncarboxylic acid, pyrrolcarboxylic acid, furancarboxylic acid, pyridinecarboxylic acid, coumarin acid, thiophenecarboxylic acid, nicotinic acid, oxysuccinic acid and dioxysuccinic acid.

The reaction solution can contain an appropriate amount of water or a low volatility organic solvent as the first liquid. The water used in this case is preferably water that has been deionized by ion exchange or the like. Further, the organic solvent that can be used in the reaction solution applied to the present invention is not particularly limited, and a known organic solvent can be used.

Further, the reaction solution can be used by adding a surfactant or a viscosity modifier to appropriately adjust the surface tension and viscosity thereof. The material used is not particularly limited as long as it can coexist with the ink high viscosity component. Specific examples of the surfactant used include an acetylene glycol ethylene oxide adduct (“Acetyleneol E100” (trade name), manufactured by Kawaken Fine Chemical Co., Ltd.) and a perfluoroalkylethylene oxide adduct (“Megafuck F444” (trade name)). , DIC Corporation) and the like.

<Ink application device>
An inkjet head is used as an ink applying device for applying ink. Examples of the inkjet head include a form in which a film is boiled in the ink by an electric-heat converter to form bubbles to eject the ink, a form in which the ink is ejected by an electric-mechanical converter, and an ink using static electricity. Examples thereof include a discharge form. In the present invention, a known inkjet head can be used. Among them, those using an electric-heat converter are preferably used from the viewpoint of high-speed and high-density printing. Drawing is performed by receiving an image signal and applying a required amount of ink to each position.

The amount of ink applied can be expressed by image density (duty) or ink thickness, but in the present invention, the average value obtained by multiplying the mass of each ink dot by the number of applied ink dots and dividing by the print area is the amount of ink applied (g / m ^2). ). The maximum amount of ink applied in the image area is the amount of ink applied in an area of at least 5 mm ² or more in the area used as information of the recorded object from the viewpoint of removing the liquid component in the ink. Shown.

The inkjet recording apparatus according to the present invention may have a plurality of inkjet heads in order to apply ink of each color on the object to be recorded. For example, when forming each color image using yellow ink, magenta ink, cyan ink, and black ink, the inkjet recording device has four inkjet heads that eject the above four types of ink onto the object to be recorded.

Further, the ink applying device may include an inkjet head that ejects ink (clear ink) that does not contain a coloring material.

<Ink>
Each component of the ink applied to the present invention will be described.

(Color material)
The coloring material contained in the ink applied to the present invention preferably contains a pigment. For example, it is preferable to use a pigment or a mixture of a dye and a pigment as a coloring material. The type of pigment that can be used as a coloring material is not particularly limited. Specific examples of the pigment include inorganic pigments such as carbon black; organic pigments such as azo-based, phthalocyanine-based, quinacridone-based, isoindolinone-based, imidazolone-based, diketopyrrolopyrrole-based, and dioxazine-based pigments. As these pigments, one kind or two or more kinds can be used as needed.

The type of dye that can be used as a coloring material is not particularly limited. Specific examples of the dye include a direct dye, an acid dye, a basic dye, a disperse dye, an edible dye, and the like, and a dye 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, an anthrapyridone skeleton and the like.

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 dispersant for dispersing the pigment, a known dispersant used for an ink for inkjet can be used. Above all, in the aspect of the present invention, 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 composed of a resin obtained by copolymerizing at least a hydrophilic monomer and a hydrophobic monomer is preferably used. The monomer used here is not particularly limited, and known ones are preferably used. Specifically, examples of the hydrophobic monomer include styrene and other styrene derivatives, alkyl (meth) acrylate, benzyl (meth) acrylate and the like. 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. The weight average molecular weight of the dispersant is preferably 1000 or more and 50,000 or less. The mass ratio of the pigment to the dispersant (pigment: dispersant) is preferably in the range of 1: 0.1 to 1: 3.

It is also preferable in the present invention to use a so-called self-dispersing pigment in which the pigment itself is surface-modified so that it can be dispersed without using a dispersant.

(Resin fine particles)
The ink applied to the present invention can be used in a state containing various fine particles having no coloring material. Among them, 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 invention is not particularly limited, and a known resin can be appropriately used. Specifically, copolymers of polyolefins, polystyrenes, polyurethanes, polyesters, polyethers, polyureas, polyamides, polyvinyl alcohols, poly (meth) acrylic acids and salts thereof, alkyl poly (meth) acrylates, polydiene and the like, or , Copolymers obtained by combining a plurality of monomers for producing these homopolymers and polymerizing them. The weight average molecular weight (Mw) of the resin is preferably in the range of 1,000 or more and 2,000,000 or less. The amount of the resin fine particles in the ink is preferably 1% by mass or more and 50% by mass or less, and more preferably 2% by mass or more and 40% by mass or less with respect to the total mass of the ink.

Further, in the aspect of the present invention, it is preferable to use it as a resin fine particle dispersion in which the resin fine particles are dispersed in a liquid. The method of dispersion is not particularly limited, but a so-called self-dispersing resin fine particle dispersion in which a monomer having a dissociative group is dispersed by using a resin obtained by homopolymerization or copolymerization of a plurality of types is suitable. Here, examples of the dissociative group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group, and examples of the monomer having this dissociative group include acrylic acid and methacrylic acid. Further, a so-called emulsified dispersion type resin fine particle dispersion in which resin fine particles are dispersed by an emulsifier can also be preferably used in the present invention. As the emulsifier referred to here, a known surfactant is preferable regardless of the low molecular weight and the high molecular weight. As the surfactant, a nonionic surfactant or a surfactant having the same charge as the resin fine particles is preferable.

The resin fine particle dispersion used in the embodiment of the present invention preferably has a dispersed particle size of 10 nm or more and 1000 nm or less, more preferably 50 nm or more and 500 nm or less, and more preferably 100 nm or more and 500 nm or less. It is more preferable to have.

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

(Curing component)
In the present invention, it is preferable that either the reaction solution or the ink contains a component that is cured by active energy rays. By curing the component that is cured by the active energy ray before the liquid absorption step, adhesion of the coloring material to the liquid absorption member may be suppressed.

As the component that is cured by irradiation with the active energy ray used in the present invention, a component that is cured by irradiation with the active energy ray and becomes more insoluble than before irradiation is used. As an example, a general ultraviolet curable resin can be used. Most of the ultraviolet curable resins are insoluble in water, but as a material suitable for the water-based ink preferably used in the present invention, the structure has at least an ethylenically unsaturated bond curable by ultraviolet rays and is compatible with the water-based ink. It preferably has a hydrophilic binding group. Examples of the bonding group for imparting hydrophilicity include a hydroxyl group, a carboxyl group, a phosphoric acid group, a sulfonic acid group and salts thereof, an ether bond, an amide bond and the like. Further, the curing component used in the present invention is preferably hydrophilic. Further, examples of the active energy ray include ultraviolet rays, infrared rays, and electron beams.

Further, in the present invention, it is preferable that either the reaction solution or the ink contains a polymerization initiator. The polymerization initiator used in the present invention may be any compound that generates radicals by active energy rays.

Further, in order to improve the reaction rate, it is also extremely preferable to use a sensitizer having a role of widening the absorption wavelength of light in combination.

(Surfactant)
The ink that can be used in the present invention may contain a surfactant. Specific examples of the surfactant include an acetylene glycol ethylene oxide adduct (acetylenolol E100 (trade name), manufactured by Kawaken Fine Chemicals Co., Ltd.) and the like. 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 solvent)
The ink used in the present invention may contain water and / or a water-soluble organic solvent as the solvent. The water is preferably water that has been deionized by ion exchange or the like. The water content in the ink is preferably 30% by mass or more and 97% by mass or less with respect to the total mass of the ink, and more preferably 50% by mass or more and 95% by mass or less with respect to the total mass of the ink. preferable.

The type of water-soluble organic solvent used 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 ether, 2-pyrrolidone, ethanol. , Methanol, etc. Of course, two or more kinds selected from these can be mixed and 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.

(Other additives)
In addition to the above components, the inks that can be used in the present invention include pH adjusters, rust preventives, preservatives, fungicides, antioxidants, antioxidants, water-soluble resins and the like. It may contain various additives such as a Japanese agent and a viscosity regulator.

<Liquid absorption member>
In the present invention, at least a part of the first liquid from the first image is absorbed by contacting with a liquid absorbing member having a porous body, and the content of the liquid component in the first image is reduced. The contact surface of the liquid absorbing member with the first image is set as the first surface, and the porous body is arranged on the first surface. The liquid absorbing member having such a porous body moves in conjunction with the movement of the recorded body, comes into contact with the first image, and then re-contacts another first image at a predetermined cycle. Those having a shape capable of circulating and absorbing liquid are preferable. For example, a shape such as an endless belt shape or a drum shape can be mentioned.

(Porous medium)
The first embodiment and the second embodiment of the porous body will be described below. In the present invention, the porous body may be a material having a large number of pores, and for example, a material having a large number of pores formed by crossing fibers is also included in the porous body in the present invention.
(First Embodiment)
In the porous body according to the present embodiment, the first layer in contact with the first image, the second layer containing the second fiber, and the third layer containing the third fiber are in this order. It is a porous sheet laminated with the above, and satisfies the following requirements (1) to (4). (1) The average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber. (2) The second fiber has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure. (3) The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. Lower than any of the softening temperatures. (4) The average thickness of the sheath structure is smaller than the thickness of the first layer.

The present inventors have studied the use of the porous materials described in Patent Documents 1 to 3 as the porous materials in the liquid absorbing member of the inkjet recording apparatus. As a result, it was found that when a plurality of layers are laminated, there is a problem that image flow occurs depending on the degree of adhesion between the layers, or the transport strength at the time of transporting the liquid absorbing member is insufficient.

As a result of detailed examination by the present inventors, regarding the image flow, the first layer, the second layer for adhering the first layer and the third layer, and the third layer are laminated and heated. At that time, it was found that as the melting of the second layer progressed, blinding occurred in the first layer and the second layer, and image flow occurred. On the other hand, the present inventors have found that by adopting the configurations (2) to (4) above, the blinding of the first layer and the second layer can be prevented. That is, the second layer contains a second fiber having a core-sheath structure having a core structure forming the central axis and a sheath structure surrounding the core structure. The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. Lower than either. At this time, by heating and laminating only the material forming the sheath structure under the condition of softening, the core structures do not melt in the heating step and the entire second layer does not melt, so that the second layer does not melt. It is possible to prevent the blinding of the eyes. Further, since the average thickness of the sheath structure is smaller than the thickness of the first layer, it is possible to prevent the first layer from being crushed. If the first and second layers can be prevented from being crushed, the flow resistance inside the porous body can be suppressed to a low level, so that the image flow is suppressed.

Further, regarding the transport strength, the present inventors have found that by adopting the configuration of (1) above, the adhesiveness between the second layer and the third layer is improved, and the transport strength is improved. It was. That is, when the third layer contains the third fiber, the average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber, so that only the material forming the sheath structure is softened. The second fiber of the second layer enters between the third fiber of the third layer, and an anchor effect is generated. As a result, the adhesive strength between the second layer and the third layer is improved, and the transport strength is improved.

FIG. 6 shows an example of the porous body according to the present embodiment. The porous body shown in FIG. 6 includes a first layer 21, a second layer 41 containing the second fibers 44, and a third layer 31 containing the third fibers 32. The second fiber 44 has a core-sheath structure having a core structure 42 forming a central axis and a sheath structure 43 surrounding the core structure 42. The average fiber diameter d2 of the second fiber 44 is larger than the average fiber diameter d3 of the third fiber 32. The average thickness t2 of the sheath structure 43 is smaller than the thickness t1 of the first layer 21.

The porous body may consist of a first layer, a second layer and a third layer, and includes other layers in addition to the first layer, the second layer and the third layer. May be good. The thickness of the porous body is preferably thin from the viewpoint of uniformly obtaining high air permeability, and can be, for example, 50 to 500 μm. The air permeability can be indicated by a garley value defined by JIS P8117, and the garley value of the porous body is preferably 10 seconds or less. The shape of the porous body is not particularly limited, and examples thereof include a roller shape and a belt shape.

[First layer]
The first layer is a layer that comes into contact with the first image and is a porous layer that directly touches the first image and absorbs at least a portion of the first liquid. The material forming the first layer is not particularly limited, but it is preferable to contain a fluororesin having a low surface free energy from the viewpoint of suppressing adhesion of the coloring material and improving the cleanability. That is, the first layer preferably contains a fluororesin, and more preferably made of a fluororesin. Specific examples of the fluororesin include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), perfluoroalkoxyfluororesin (PFA), and the like. Examples thereof include ethylene tetrafluoride / propylene hexafluoride copolymer (FEP), ethylene / ethylene tetrafluoride copolymer (ETFE), and ethylene / chlorotrifluoroethylene copolymer (ECTFE). As these materials, one kind or two or more kinds can be used as needed. Further, the first layer may have a structure in which a plurality of films made of different materials are laminated.

The softening temperature of the material forming the first layer is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, from the viewpoint of making it higher than the softening temperature of the material forming the sheath structure in the second fiber. More preferably 200 ° C. or higher. The upper limit of the softening temperature range of the material forming the first layer is not particularly limited, but may be, for example, 350 ° C. or lower. In the present invention, the softening temperature is a value measured by DSC (differential scanning calorimetry). When the first layer contains a plurality of materials, the softening temperature in the state containing the plurality of materials is shown.

The material forming the first layer is preferably flexible enough not to leave a trace on the first image, and the Young's modulus of the material is preferably 2.0 GPa or less, preferably 1.0 GPa or less. More preferably, 0.5 GPa or less is further preferable. The lower limit of the Young's modulus range is not particularly limited, but may be, for example, 0.1 GPa or more. In the present invention, Young's modulus is a value measured by the method specified in JIS K7161.

The average pore diameter on the surface of the first layer on the side in contact with the first image is preferably 10.0 μm or less from the viewpoint of suppressing adhesion of the coloring material when the first image is pressed against the first image. It is more preferably 0 μm or less, and further preferably 0.2 μm or less. In particular, when the average pore size is 0.2 μm or less, the filterability is enhanced and the adhesion of the coloring material to the porous body is significantly suppressed. In the present invention, the average pore diameter is the average value measured at 20 points or more as the diameter when the surface of the porous layer is observed with an electron microscope and the area of the pore portion on the surface is the area of a circle. is there. The lower limit of the range of the average pore size is not particularly limited, but can be, for example, 0.02 μm or more.

The thickness of the first layer is preferably 50 μm or less, more preferably 30 μm or less, further preferably 10 μm or less, and particularly preferably 5 μm or less. When the thickness is 50 μm or less, an increase in flow resistance can be suppressed and image flow can be suppressed. The lower limit of the thickness range is not particularly limited, but may be, for example, 1 μm or more. In the present invention, the thickness can be obtained by measuring the thickness at any 10 points with a straight-ahead micrometer (trade name: OMV-25, manufactured by Mitutoyo Co., Ltd.) and calculating the average value thereof. The value.

[Second layer]
The second layer is a porous layer that adheres the first layer and the third layer. The second layer contains the second fiber and may consist of the second fiber. Even if a part of the second fiber is melted, if the second fiber remains in the fiber shape in the second layer, the second layer is assumed to contain the second fiber. The same applies to the second fiber a contained in the second layer a and the second fiber b contained in the second layer b, which will be described later. The second layer may be a non-woven fabric or a woven fabric. The second fiber has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure. The material forming the core structure and the material forming the sheath structure are not particularly limited as long as the relationship of the softening temperature in the present embodiment is satisfied, but for example, polyolefin (polyethylene (PE), polypropylene (PP), etc.), polyurethane, and the like. Polyamide such as nylon, polyester (polyethylene terephthalate (PET), etc.), polysulfone (PSF) and the like can be mentioned. These may be used alone or in combination of two or more.

The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the formation of the third fiber contained in the third layer. It is lower than any of the softening temperatures of the material to be used. As a result, when the first to third layers are bonded by heating, only the material forming the sheath structure can be softened by selecting the heating temperature, and the core structure does not melt, so that the second layer The shape of the fiber can be maintained. Therefore, since the entire second layer is not melted down, it is possible to prevent the second layer from being crushed. The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the formation of the third fiber contained in the third layer. It is preferably 5 ° C. or higher lower than any of the softening temperatures of the materials to be used, and more preferably 10 ° C. or higher.

The softening temperature of the material forming the core structure is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, from the viewpoint of satisfying the relationship of the softening temperature in the present embodiment. The upper limit of the softening temperature range of the material forming the core structure is not particularly limited, but may be, for example, 180 ° C. or lower. Further, the softening temperature of the material forming the sheath structure is preferably less than 140 ° C., more preferably 130 ° C. or lower, from the viewpoint of satisfying the relationship of the softening temperature in the present embodiment. The lower limit of the softening temperature range of the material forming the sheath structure is not particularly limited, but can be, for example, 110 ° C. or higher.

The Young's modulus of the material forming the core structure is preferably 0.1 to 3.0 GPa from the viewpoint of transportability. The Young's modulus of the material forming the sheath structure is preferably 0.1 to 3.0 GPa from the viewpoint of transportability.

The average thickness of the sheath structure is smaller than the thickness of the first layer. An enlarged view of the A portion of the porous body shown in FIG. 6 is shown in FIG. 7 (a). As shown in FIG. 7A, the average thickness t2 of the sheath structure 43 of the second layer 41 is smaller than the thickness t1 of the first layer 21 so that the first layer 21 is not blinded (t2). <T1). On the other hand, if the relationship of t2 ≧ t1 is satisfied, as shown in FIG. 7B, blinding occurs in the first layer 21, resulting in image flow. The average thickness of the sheath structure is preferably 1.0 μm or more smaller than the thickness of the first layer, and more preferably 1.5 μm or more smaller. Further, as shown in FIG. 7A, since the sheath structure 43 of the first layer 21 and the second layer 41 are adhered to each other, between the first layer 21 and the second layer 41. Adhesive strength is also improved.

The average thickness of the sheath structure is preferably 0.5 to 5.0 μm, more preferably 1.0 to 4.0 μm, from the viewpoint of satisfying the above relationship. The average diameter of the core structure is preferably 1.0 to 30.0 μm, more preferably 5.0 to 20.0 μm. In the present invention, the average thickness of the sheath structure and the average diameter of the core structure are average values of measured values at 20 or more points obtained by SEM observation after forming a cross section by ion milling, FIB, or the like. Further, the average thickness of the sheath structure is measured and calculated at a portion where the sheath structure is partially melted but not melted.

The average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber. An enlarged view of the B portion of the porous body shown in FIG. 6 is shown in FIG. 7 (c). As shown in FIG. 7 (c), the average fiber diameter d2 of the second layer is larger than the average fiber diameter d3 of the third layer (d2> d3). As a result, when the second fiber 44 of the second layer enters between the third fibers 32 of the third layer, the third fiber 32 and the second fiber 44 are separated by melting of the sheath structure 43. It adheres and the adhesive strength is improved by the anchor effect. On the other hand, if the relationship of d2 ≦ d3 is satisfied, the second fiber 44 of the second layer adheres to the third fiber 32 of the third layer by the anchor effect as shown in FIG. 7 (d). The second layer and the third layer are easily separated from each other, as shown in FIG. 7 (e). The average fiber diameter of the second fiber is preferably 1 μm or more larger than the average fiber diameter of the third fiber, and more preferably 2 μm or more.

The average fiber diameter of the second fiber is preferably 10 to 50 μm, more preferably 15 to 30 μm from the viewpoint of satisfying the above relationship. In the present invention, the average fiber diameter is an average value of measured values at 20 or more points obtained by SEM observation from the surface or SEM observation after forming a cross section by ion milling, FIB, or the like. Further, the average fiber diameter is measured and calculated at a portion where the sheath structure is partially melted but not melted.

The thickness of the second layer is preferably 10 to 500 μm from the viewpoint of transportability.

[Third layer]
The third layer is a porous layer that increases the rigidity of the liquid absorbing member. The third layer contains the third fiber and may consist of the third fiber. The third layer may be a non-woven fabric or a woven fabric. The material forming the third fiber is not particularly limited as long as the relationship of the softening temperature in the present invention is satisfied, and examples thereof include polyphenylene sulfide (PPS), polyimide, and polyethylene terephthalate (PET). These may be used alone or in combination of two or more. However, as will be described later, the third fiber preferably contains polyphenylene sulfide (PPS) or polyimide from the viewpoint of having a high Young's modulus and improving the transport strength.

The softening temperature of the material forming the third fiber is preferably 150 ° C. or higher, more preferably 170 ° C. or higher, and further 200 ° C. or higher, from the viewpoint of satisfying the relationship of the softening temperature in the present invention. preferable. The upper limit of the softening temperature range of the material forming the third fiber is not particularly limited, but can be, for example, 350 ° C. or lower.

The Young's modulus of the material forming the third fiber is preferably higher than the Young's modulus of the material forming the first layer from the viewpoint of increasing the transport strength and ensuring the rigidity. The Young's modulus of the material forming the third fiber is preferably 1.0 GPa or more higher than the Young's modulus of the material forming the first layer, and more preferably 2.0 GPa or more. The Young's modulus of the material forming the third fiber is preferably 2.0 GPa or more, more preferably 2.5 GPa or more, and further preferably 3.0 GPa or more. The upper limit of the Young's modulus range is not particularly limited, but can be, for example, 5.0 GPa or less. The third layer made of the material having Young's modulus will ultimately largely determine the stiffness of the porous sheet. A tension of about 2.5 to 10.0 mN / mm is applied to the porous sheet for stable transportation. At that time, if the porous sheet has a large elongation, the transfer stability cannot be ensured against tension fluctuations and the like. In order to ensure the transfer stability, it is preferable to suppress the elongation to 2% or less in the range of elastic deformability in the range of 2.5 to 10.0 mN / mm. The elongation in the range of tension and elastic deformability is a value measured by "Autograph AG-X" (trade name) manufactured by Shimadzu Corporation.

The thickness of the third layer is preferably 50 to 500 μm, more preferably 100 to 400 μm, and even more preferably 150 to 300 μm from the viewpoint of increasing the transport strength and ensuring the rigidity. The average fiber diameter of the third fiber is preferably 2 to 15 μm, more preferably 5 to 10 μm, from the viewpoint of making it smaller than the average fiber diameter of the second fiber.

(Second embodiment)
The other porous body according to the present embodiment includes a first layer in contact with the first image, a second layer a containing the second fiber a, and a second layer containing the second fiber b. b and the third layer containing the third fiber are laminated in this order to form a porous sheet, which satisfies the following requirements (1) to (5). (1) The average fiber diameter of the second fiber b is larger than the average fiber diameter of the third fiber. (2) The second fiber a and the second fiber b have a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure. (3) The softening temperature of the material forming the sheath structure of the second fiber a is the softening temperature of the material forming the core structure of the second fiber a and the softening temperature of the material forming the first layer. Lower than any of. (4) The softening temperature of the material forming the sheath structure of the second fiber b is the softening temperature of the material forming the core structure of the second fiber b and the softening temperature of the material forming the third fiber. Lower than any of. (5) The average thickness of the sheath structure of the second fiber a is smaller than the thickness of the first layer.

An example of the porous body according to this embodiment is shown in FIG. The porous body shown in FIG. 8 includes a first layer 21, a second layer a41a containing a second fiber a44a, a second layer b41b containing a second fiber b44b, and a third fiber 32. Includes a third layer 31 containing. The second fiber a44a has a core-sheath structure having a core structure 42a forming a central axis and a sheath structure 43a surrounding the core structure 42a. Further, the second fiber b44b has a core-sheath structure having a core structure 42b forming a central axis and a sheath structure 43b surrounding the core structure 42b. The average fiber diameter d2b of the second fiber b44b is larger than the average fiber diameter d3 of the third fiber 32. The average thickness t2a of the sheath structure 43a of the second fiber a44a is smaller than the thickness t1 of the first layer 21.

In the first embodiment shown in FIG. 6, in order to make the average fiber diameter d2 of the second fiber 44 larger than the average fiber diameter d3 of the third fiber 32, the average fiber diameter of the second fiber 44 If d2 is made too large, the unevenness on the surface of the second layer 41 may spread to the first layer 21. In this case, the image may be distorted in the absorption of the first liquid from the first image. On the other hand, in the present embodiment, the second layer in the first embodiment is composed of a second layer a41a containing the second fiber a44a and a second layer b41b containing the second fiber b44b. ing. The second layer a41a is arranged on the first layer 21 side, and the second layer b41b is arranged on the third layer 31 side. Here, since the dimensions of the core-sheath structure of the second fiber a44a and the dimensions of the core-sheath structure of the second fiber b44b can be different, the surface of the second layer on the first layer side. The average fiber diameter of the second fiber can be easily made larger than the average fiber diameter of the third fiber while suppressing the unevenness of the third fiber. That is, the average fiber diameter d2b of the second fiber b44b is larger than the average fiber diameter d3 of the third fiber 32 (d2b> d3), and the average thickness t2a of the sheath structure 43a of the second fiber a44a is the first layer. By making the thickness of 21 smaller than t1 (t1> t2a), while suppressing the unevenness of the surface of the second layer on the first layer side, the first layer is prevented from being crushed, and the second layer and the third layer are used. It is possible to easily achieve both improvement in adhesive strength with the layer of.

[First layer and third layer]
The first layer and the third layer in the present embodiment may have the same configuration as the first layer and the third layer in the first embodiment.

[Second layer a]
The second layer a is a porous layer that is arranged on the side of the first layer and adheres to the first layer. The second layer a contains the second fiber a and may consist of the second fiber a. The second layer a may be a non-woven fabric or a woven fabric. The second fiber a has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure. The material forming the core structure and the material forming the sheath structure of the second fiber a are not particularly limited as long as the relationship of the softening temperature in the present embodiment is satisfied, and the material in the first embodiment is used. The same material as the second fiber can be used.

The softening temperature of the material forming the sheath structure of the second fiber a is higher than the softening temperature of the material forming the core structure of the second fiber a or the softening temperature of the material forming the first layer. Is also low. Thereby, when the first layer and the second layer a are bonded by heating, only the material forming the sheath structure of the second fiber a can be softened by selecting the heating temperature. The core structure of the second fiber a does not melt. Therefore, the shape of the second fiber a can be maintained, and the blinding of the second layer a can be prevented. The softening temperature of the material forming the sheath structure of the second fiber a is higher than the softening temperature of the material forming the core structure of the second fiber a or the softening temperature of the material forming the first layer. Is preferably 5 ° C. or higher, and more preferably 10 ° C. or higher.

The softening temperature of the material forming the core structure of the second fiber a is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, from the viewpoint of satisfying the relationship of the softening temperature in the present embodiment. The upper limit of the softening temperature range of the material forming the core structure of the second fiber a is not particularly limited, but may be, for example, 180 ° C. or lower. Further, the softening temperature of the material forming the sheath structure of the second fiber a is preferably less than 140 ° C., more preferably 130 ° C. or lower, from the viewpoint of satisfying the relationship of the softening temperature in the present embodiment. preferable. The lower limit of the softening temperature range of the material forming the sheath structure of the second fiber a is not particularly limited, but can be, for example, 110 ° C. or higher.

The Young's modulus of the material forming the core structure of the second fiber a is preferably 0.1 to 3.0 GPa from the viewpoint of transportability. Further, the Young's modulus of the material forming the sheath structure of the second fiber a is preferably 0.1 to 3.0 GPa from the viewpoint of transportability.

The average thickness of the sheath structure of the second fiber a is smaller than the thickness of the first layer from the viewpoint of suppressing image flow due to the blinding of the first layer. The average thickness of the sheath structure of the second fiber a is preferably 1.0 μm or more smaller than the thickness of the first layer, and more preferably 2.0 μm or more. The average thickness of the sheath structure of the second fiber a is preferably 0.5 to 5.0 μm, more preferably 1.0 to 3.0 μm from the viewpoint of satisfying the above relationship. The average diameter of the core structure of the second fiber a is preferably 1.0 to 10.0 μm, more preferably 2.0 to 8.0 μm.

The average fiber diameter of the second fiber a is preferably 1 to 10 μm, more preferably 2 to 8 μm, from the viewpoint of suppressing unevenness on the surface of the second layer a. The thickness of the second layer a is preferably 10 to 500 μm from the viewpoint of transportability.

[Second layer b]
The second layer b is a porous layer that is arranged on the side of the third layer and adheres to the third layer. The second layer b contains the second fiber b and may consist of the second fiber b. The second layer b may be a non-woven fabric or a woven fabric. The second fiber b has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure. The material forming the core structure and the material forming the sheath structure of the second fiber b are not particularly limited as long as they satisfy the relationship of the softening temperature in the present embodiment, and are not particularly limited in the first embodiment. The same material as the second fiber can be used.

The softening temperature of the material forming the sheath structure of the second fiber b is higher than the softening temperature of the material forming the core structure of the second fiber b or the softening temperature of the material forming the third fiber. Is also low. Thereby, when the second layer b and the third layer are bonded by heating, only the material forming the sheath structure of the second fiber b can be softened by selecting the heating temperature. The core structure of the second fiber b does not melt. Therefore, the shape of the second fiber b can be maintained, and the blinding of the second layer b can be prevented. The softening temperature of the material forming the sheath structure of the second fiber b is higher than the softening temperature of the material forming the core structure of the second fiber b or the softening temperature of the material forming the third layer. Is preferably 5 ° C. or higher, and more preferably 10 ° C. or higher.

The softening temperature of the material forming the core structure of the second fiber b is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, from the viewpoint of satisfying the relationship of the softening temperature in the present embodiment. The upper limit of the softening temperature range of the material forming the core structure of the second fiber b is not particularly limited, but may be, for example, 180 ° C. or lower. Further, the softening temperature of the material forming the sheath structure of the second fiber b is preferably less than 140 ° C., more preferably 130 ° C. or lower, from the viewpoint of satisfying the relationship of the softening temperature in the present embodiment. preferable. The lower limit of the softening temperature range of the material forming the sheath structure of the second fiber b is not particularly limited, but can be, for example, 110 ° C. or higher.

The Young's modulus of the material forming the core structure of the second fiber b is preferably 0.1 to 3.0 GPa from the viewpoint of transportability. Further, the Young's modulus of the material forming the sheath structure of the second fiber b is preferably 0.1 to 3.0 GPa from the viewpoint of transportability.

The average thickness of the sheath structure of the second fiber a is preferably 0.5 to 5.0 μm, more preferably 1.0 to 4.0 μm. The average diameter of the core structure of the second fiber a is preferably 1.0 to 30.0 μm, more preferably 5.0 to 20.0 μm.

The average fiber diameter of the second fiber b is larger than the average fiber diameter of the third fiber from the viewpoint of improving the adhesive strength between the second layer b and the third layer. The average fiber diameter of the second fiber b is preferably 1 μm or more larger than the average fiber diameter of the third fiber, and more preferably 2 μm or more. The average fiber diameter of the second fiber b is preferably 10 to 50 μm, more preferably 15 to 30 μm from the viewpoint of satisfying the above relationship. The thickness of the second layer b is preferably 10 to 500 μm from the viewpoint of transportability.

(Manufacturing method of porous body)
In the first embodiment, the first layer that comes into contact with the first image by heating, the second layer containing the second fiber, and the third layer containing the third fiber. Can produce a porous body laminated in this order. The heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure, the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the third. The temperature should be below the softening temperature of the material that forms the fibers. As a result, only the material forming the sheath structure can be softened, and the core structure does not melt, so that the shape of the second fiber can be maintained. Therefore, since the entire second layer is not melted down, it is possible to prevent the second layer from being crushed. Further, the heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure, and the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the first layer. It is preferably below the softening temperature of the material forming the third fiber. The heating temperature is preferably 100 to 150 ° C., for example, although it depends on the material used.

Further, in the second embodiment, the first layer that comes into contact with the first image by heating, the second layer a containing the second fiber a, and the second layer b containing the second fiber b are included. A porous body in which the second layer b and the third layer containing the third fiber are laminated in this order can be produced. The heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure of the second fiber a and the second fiber b, and the core of the second fiber a and the second fiber b. It is set to be equal to or lower than the softening temperature of the material forming the structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. As a result, only the material forming the sheath structure of the second fiber a and the second fiber b can be softened, and the core structures of the second fiber a and the second fiber b are melted. Therefore, the shapes of the second fiber a and the second fiber b can be maintained. Therefore, since the entire second layer a and the second layer b are not melted down, it is possible to prevent the second layer a and the second layer b from being crushed. Further, the heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure of the second fiber a and the second fiber b, and the temperature of the second fiber a and the second fiber b is higher. It is preferably lower than the softening temperature of the material forming the core structure of the above, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. The heating temperature is preferably 100 to 150 ° C., for example, although it depends on the material used.

When performing the heating, pressurization may be performed at the same time. For example, a method in which the laminate is sandwiched between heated rollers and laminated while being pressurized is preferable. At that time, the material forming the sheath structure of the second layer (second layer a and second layer b) penetrates into the pores of the first layer and the third layer to the extent that it does not collapse. Is preferable. Further, all the layers may be laminated and then heated, or two layers may be laminated and heated, and then another layer may be laminated and heated, and so on. Good.

FIG. 9 shows an example of a laminator that can be used in the method for producing a porous body. In the laminator shown in FIG. 9, a porous body can be produced by sequentially laminating and heating each layer. The laminator is provided with a transport belt 620 for transporting and laminating each sheet to be laminated. The transport belt 620 is driven by the belt transport roller 630. The first sheet 601 is conveyed by the first sheet transfer roller 611. The first sheet 601 and the second sheet 602 are heated and pressurized by heated nip rollers 612a and 612b and welded. The welded laminate sheet 603 is taken up by a take-up roller 613. The temperature of the nip rollers 612a and 612b is preferably the temperature of the heating.

Next, a specific embodiment of the inkjet recording apparatus of the present invention will be described.

The inkjet recording device of the present invention is an inkjet recording device that forms a first image on a transfer body as a recording body and transfers a second image after the first liquid absorption by a liquid absorbing member to a recording medium. And an inkjet recording device that forms a first image on a recording medium as a recording object. In the present invention, the former inkjet recording device is hereinafter referred to as a transfer type inkjet recording device for convenience, and the latter inkjet recording device is hereinafter referred to as a direct drawing type inkjet recording device for convenience.

Each inkjet recording device will be described below.

(Transfer type inkjet recording device)
FIG. 1 is a schematic view showing an example of a schematic configuration of the transfer type inkjet recording device of the present embodiment.

The transfer-type inkjet recording device 100 includes a transfer body 101 that temporarily holds a first image and a second image that has absorbed at least a part of the first liquid from the first image. Further, the transfer type inkjet recording device 100 includes a transfer unit including a transfer pressing member 106 for transferring the second image onto a recording medium 108 on which an image is to be formed.

The transfer-type inkjet recording apparatus 100 of the present invention includes a transfer body 101 supported by a support member 102, a reaction solution applying device 103 for applying a reaction solution onto the transfer body 101, and a transfer body 101 to which the reaction solution is applied. Presses the ink applying device 104 that applies ink to the transfer body to form an ink image (first image) on the transfer body, the liquid absorbing device 105 that absorbs the liquid component from the first image on the transfer body, and the recording medium. By doing so, it has a pressing member 106 that transfers a second image on the transfer body from which the liquid component has been removed onto a recording medium 108 such as paper. Further, the transfer type inkjet recording device 100 may have a transfer body cleaning member 109 that cleans the surface of the transfer body 101 after transferring the second image to the recording medium 108.

The support member 102 is rotated about the rotation axis 102a in the direction of arrow A in FIG. The rotation of the support member 102 causes the outer peripheral surface of the transfer body 101 to move in the direction of arrow A. The reaction solution is sequentially applied by the reaction solution applying device 103 and the ink is applied by the ink applying device 104 on the transferred body 101 to be moved, and the first image is formed on the transfer body 101. The first image formed on the transfer body 101 is moved to a position where it comes into contact with the liquid absorption member 105a included in the liquid absorption device 105 by the rotational movement of the transfer body 101.

The liquid absorbing member 105a of the liquid absorbing device 105 moves in synchronization with the rotation of the transfer body 101. The first image formed on the transfer body 101 goes through a state of being in contact with the moving liquid absorbing member 105a. During this time, the liquid absorbing member 105a removes the liquid component from the first image.

The liquid component contained in the first image is removed by passing through the state of being in contact with the liquid absorbing member 105a. In this contacted state, it is preferable that the liquid absorbing member 105a is pressed against the first image with a predetermined pressing force in order for the liquid absorbing member 105a to function effectively.

Explaining the removal of the liquid component from a different viewpoint, it can also be expressed as concentrating the ink constituting the first image formed on the transfer body. Concentrating the ink means that the liquid component contained in the ink is reduced, so that the content ratio of the solid content such as the coloring material and the resin contained in the ink to the liquid component is increased.

Then, the second image after the liquid component is removed is moved to the transfer unit in contact with the recording medium 108 conveyed by the recording medium transfer device 107 by the rotational movement of the transfer body 101. While the second image after the liquid component is removed is in contact with the recording medium 108, the pressing member 106 presses the recording medium 108 to form an ink image on the recording medium 108. The transferred ink image transferred onto the recording medium 108 is an inverted image of the second image. In the following description, apart from the first image (ink image before liquid removal) and the second image (ink image after liquid removal) described above, the ink image after transfer may be referred to as a third image.

Since the ink is applied on the transfer body after the reaction solution is applied to form the first image, the reaction solution does not react with the ink in the non-image region (non-ink image forming region). Remaining. In this apparatus, the liquid absorbing member 105a not only removes the liquid component from the first image, but also comes into contact (pressure contact) with the unreacted reaction liquid, and the liquid component in the reaction liquid is also brought together on the surface of the transfer body 101. Is being removed from.

Therefore, in the above, it is expressed and explained that the liquid component is removed from the first image, but it does not mean that the liquid component is removed only from the first image, but at least the first on the transfer body. It is used in the sense that the liquid component should be removed from the image. For example, it is also possible to remove the liquid component in the reaction solution imparted 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 constant shape, has fluidity, and has a substantially constant volume. For example, water, an organic solvent, etc. contained in an ink or a reaction liquid can be mentioned as liquid components.
Further, even when the above-mentioned clear ink is contained in the first image, the ink can be concentrated by the liquid absorption treatment. 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 is present on the entire surface of the first image, or the first image is formed. Clear ink is partially present in one or more places on the surface of one image, and color ink is present in other places. 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 toward the porous body side, so that the liquid component in the color ink is absorbed. On the other hand, in the place where the clear ink region and the color ink region 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, so that the liquid components are absorbed. Ink. The clear ink may contain a large amount of components for improving the transferability of the image from the transfer body 101 to the recording medium 108. For example, it is possible to increase the content of a component that becomes more adhesive to a recording medium by heating than a color ink.

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

<Transcribant>
The transfer body 101 has a surface layer including an image forming surface. As a member of the surface layer, various materials such as resin and ceramic can be appropriately used, but a material having a high compressive elastic modulus is preferable in terms of durability and the like. Specific examples thereof include an acrylic resin, an acrylic silicone resin, a fluorine-containing resin, and a condensate obtained by condensing a hydrolyzable organosilicon compound. In order to improve the wettability, transferability, etc. of the reaction solution, it may be used after being surface-treated. Examples of the surface treatment include frame treatment, corona treatment, plasma treatment, polishing treatment, roughening treatment, active energy ray irradiation treatment, ozone treatment, surfactant treatment, silane coupling treatment and the like. A plurality of these may be combined. Further, any surface shape can be provided on the surface layer.

Further, the transfer material preferably has a compression layer having a function of absorbing pressure fluctuations. By providing the compression layer, the compression layer absorbs the deformation, disperses the fluctuation against local pressure fluctuations, and can maintain good transferability even during high-speed printing. Examples of the material of the compression layer include acrylonitrile-butadiene rubber, acrylic rubber, chloroprene rubber, urethane rubber, silicone rubber and the like. When molding each of the above rubber materials, it is preferable to add a predetermined amount of a vulcanizing agent, a vulcanization accelerator, etc., and further add a foaming agent, hollow fine particles, a filler such as salt, etc. as necessary to make the rubber material porous. .. As a result, since the bubble portion is compressed with a volume change in response to various pressure fluctuations, deformation in directions other than the compression direction is small, and more stable transferability and durability can be obtained. As the porous rubber material, there are a continuous pore structure in which each pore is continuous with each other and an independent pore structure in which each pore is independent. In the present invention, any structure may be used, and these structures may be used in combination.

Further, the transfer material preferably has an elastic layer between the surface layer and the compression layer. As the material of the elastic layer, various materials such as resin and ceramic can be appropriately used. Various elastomer materials and rubber materials are preferably used in terms of processing characteristics and the like. Specifically, for example, fluorosilicone rubber, phenylsilicone rubber, fluororubber, chloroprene rubber, urethane rubber, nitrile rubber, ethylene propylene rubber, natural rubber, styrene rubber, isoprene rubber, butadiene rubber, ethylene / propylene / butadiene copolymer, Examples thereof include nitrile butadiene rubber. In particular, silicone rubber, fluorosilicone rubber, and phenylsilicone rubber are preferable in terms of dimensional stability and durability because they have a small compression set. In addition, the change in elastic modulus with temperature is small, which is preferable in terms of transferability.

Various adhesives or double-sided tape may be used between the layers (surface layer, elastic layer, compression layer) constituting the transfer body to fix and hold them. Further, a reinforcing layer having a high compressive elastic modulus may be provided in order to suppress lateral elongation when mounted on the device and to maintain elasticity. Further, the woven fabric may be used as a reinforcing layer. The transfer body can be produced by arbitrarily combining each layer made of the above-mentioned material.

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 thereof include a sheet shape, a roller shape, a belt shape, and an endless web shape.

<Support member>
The transfer body 101 is supported on the support member 102. As a method of supporting the transfer body, various adhesives or double-sided tape may be used. Alternatively, the transfer body 101 may be supported on the support member 102 by attaching an installation member made of a metal, ceramic, resin, or the like to the transfer body.

The support member 102 is required to have a certain level of structural strength from the viewpoint of transport accuracy and durability. As the material of the support member, metal, ceramic, resin or the like is preferably used. Above all, in addition to rigidity and dimensional accuracy that can withstand the pressure during transfer, aluminum, iron, stainless steel, acetal resin, epoxy resin, polyimide, in order to reduce inertia during operation and improve control responsiveness, 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 device>
The inkjet recording device of the present embodiment includes a reaction solution applying device 103 that applies the reaction solution to the transfer body 101. The reaction solution application device 103 of FIG. 1 has a reaction solution accommodating portion 103a for accommodating the reaction solution, and gravure offset members 103b and 103c for applying the reaction solution in the reaction solution accommodating unit 103a onto the transfer body 101. The case of a roller is shown.

<Ink application device>
The inkjet recording device of the present embodiment has an ink applying device 104 that applies ink to the transfer body 101 to which the reaction solution has been applied. The first image is formed by mixing the reaction liquid and the ink, and the liquid component is absorbed from the first image by the next liquid absorbing device 105.

<Liquid absorber>
In the present embodiment, the liquid absorbing device 105 has a liquid absorbing member 105a and a liquid absorbing pressing member 105b that presses the liquid absorbing member 105a against the first image on the transfer body 101. The shapes of the liquid absorbing member 105a and the pressing member 105b are not particularly limited. 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 cylindrical pressing member 105b presses the belt-shaped liquid absorbing member 105a against the transfer body 101. It may be a configuration. Further, the pressing member 105b has a cylindrical shape, the liquid absorbing member 105a has a cylindrical shape formed on the peripheral surface of the cylindrical pressing member 105b, and the cylindrical pressing member 105b has a cylindrical liquid absorbing member 105a. May be pressed against the transfer body.

In the present invention, the liquid absorbing member 105a is preferably in the shape of a belt in consideration of the space in the inkjet recording device and the like.

Further, the liquid absorbing device 105 having such a belt-shaped liquid absorbing member 105a may have a stretching member for stretching the liquid absorbing member 105a. In FIG. 1, 105c, 105d, 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 tension roller, but the present invention 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. The second image is obtained by reducing the liquid component from the first image. As a method of reducing the liquid component in the first image, in addition to this method of pressing the liquid absorbing member, various other conventionally used methods, for example, a method of heating, a method of blowing low-humidity air, and a method of depressurizing. Etc. may be combined. In addition, these methods may be applied to the second image in which the liquid component is reduced to further reduce the liquid component.

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

(Preprocessing)
In the present embodiment, a pretreatment device (also referred to as a treatment liquid) for applying a wetting liquid (also referred to as a treatment liquid) to the liquid absorption member before bringing the liquid absorption member 105a having a porous body into contact with the first image (not shown in FIGS. 1 and 2). Pretreatment is preferably performed according to (shown in the figure). The wetting liquid used in the present invention preferably contains water and a water-soluble organic solvent. The water is preferably water that has been deionized by ion exchange or the like. The type of 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 invention, the method of applying the wetting liquid to the porous body is not particularly limited, but immersion or dropping of droplets is preferable. The component for adjusting the surface tension of the wet liquid is not particularly limited, but it is preferable to use a surfactant. As the surfactant, it is preferable to use at least one of a silicone-based surfactant and a fluorine-based surfactant, and it is more preferable to use a fluorine-based surfactant. The content of the surfactant in the wetting liquid is preferably 0.2% by mass or more, more preferably 0.4% by mass or more, and 0.5% by mass or more with respect to the total mass of the wetting liquid. Especially preferable. The upper limit of the content of the surfactant in the wet liquid is not particularly limited, but from the viewpoint of the solubility of the surfactant in the wet liquid, it is preferably 10% by mass or less with respect to the total mass of the wet liquid. ..

(Pressurization condition)
When the pressure of the liquid absorbing member pressing 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 solidified in a shorter time. It is preferable because it can be separated from the image and the liquid component can be removed from the first image. Further, when the pressure is 98 N / cm ² (10 kgf / cm ² ) or less, the structural load on the apparatus can be suppressed, which is preferable. The pressure of the liquid absorbing member in the present specification indicates the nip pressure between the recorded object and the liquid absorbing member, and is a surface pressure distribution measuring instrument (I-SCAN (trade name), Nitta Co., Ltd.). The surface pressure was measured by (manufactured by), and the weight in the pressurized region was divided by the area to calculate the value.

(Time of action)
The action 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 action time in the present specification is calculated by dividing the pressure sensing width in the moving direction of the recorded body by the moving speed of the recorded body in the above-mentioned surface pressure measurement. Hereinafter, this action time will be referred to as a liquid absorption nip time.

In this way, the liquid component is absorbed from the first image on the transfer body 101, and a second image in which the liquid content is reduced is formed. The second image is then transferred onto the recording medium 108 at the transfer unit. The apparatus configuration and conditions at the time of transfer will be described.

<Pressing member for transfer>
In the present embodiment, the recording medium 108 is pressed by the transfer pressing member 106 while the second image and the recording medium 108 conveyed by the recording medium transfer device 107 are in contact with each other. The ink image is transferred onto the image. By removing the liquid component contained in the first image on the transfer body 101 and then transferring the liquid component 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 level of structural strength from the viewpoint of transport accuracy and durability of the recording medium 108. As the material of the pressing member 106, metal, ceramic, resin or the like is preferably used. Above all, in addition to rigidity and dimensional accuracy that can withstand the pressure during transfer, aluminum, iron, stainless steel, acetal resin, epoxy resin, polyimide, in order to reduce inertia during operation and improve control responsiveness, Polyethylene, polyethylene terephthalate, nylon, polyurethane, silica ceramics, and alumina ceramics are preferably used. Moreover, you may use these in combination.

The time during 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 the transfer is performed well and the durability of the transfer body is not impaired. It is preferably 5 ms (milliseconds) or more and 100 ms (milliseconds) or less. The pressing time in the present embodiment indicates the time during which the recording medium 108 and the transfer body 101 are in contact with each other, and is a surface pressure distribution measuring instrument (I-SCAN (trade name), manufactured by Nitta Co., Ltd.). ) Was used to measure the surface pressure, and the length of the pressurized region in the transport direction was divided by the transport speed to calculate the value.

Further, the pressure pressed by the pressing member 106 to transfer the second image on the transfer body 101 to the recording medium 108 is not particularly limited, but the transfer is performed well and the durability of the transfer body is impaired. Be careful not to. Therefore, the pressure ^{is preferably 9.8 N / cm 2} (1 kgf / cm ² ) or more and 294.2 N / cm ² (30 kgf / cm ² ) or less. 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 pressure region is divided by the area to obtain a value. Is calculated.

The temperature when the pressing member 106 is pressed to transfer the second image on the transfer body 101 to the recording medium 108 is also not particularly limited, but is equal to or higher than the glass transition point of the resin component contained in the ink or softened. It is preferably a point or more. Further, for heating, it is preferable to include a heating device for heating the second image on the transfer body 101, 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 transfer device>
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 long ones wound in a roll shape and single-striped ones cut to a predetermined size. Examples of the material include paper, plastic film, wooden board, corrugated cardboard, metal film and the like.

Further, in FIG. 1, the recording medium transport device 107 for transporting the recording medium 108 is composed of the recording medium feeding roller 107a and the recording medium winding roller 107b, but it is sufficient if the recording medium can be conveyed, and this configuration is particularly important. It is not limited to.

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

401 is a CPU that controls the entire printer, 402 is a ROM for storing the control program of the CPU, and 403 is a RAM for executing the program. Reference numeral 404 is an integrated circuit (Application Specific Integrated Circuit: ASIC) for a specific application, which incorporates a network controller, a serial IF controller, a head data generation controller, a motor controller, and the like. Reference numeral 405 is a liquid absorbing member transport control unit for driving the liquid absorbing member transport motor 406, which is command controlled from the ASIC 404 via the serial IF. Reference numeral 407 is a transfer body drive control unit for driving the transfer body drive motor 408, which is also command-controlled from the ASIC 404 via the serial IF. Reference numeral 409 is a head control unit, which generates final ejection data, drives voltage, and the like for the inkjet device 305.

(Direct drawing type inkjet recording device)
Another embodiment of the present invention is a direct drawing type inkjet recording device. In a direct drawing type inkjet recording device, a recording object is a recording medium on which an image should be formed.

FIG. 2 is a schematic view showing an example of a schematic configuration of the direct drawing type inkjet recording device 200 according to the present embodiment. Compared with the transfer type inkjet recording device described above, the direct drawing type inkjet recording device does not have the transfer body 101, the support member 102, and the transfer body cleaning member 109, except that the image is formed on the recording medium 208. It has the same members as the transfer type inkjet recording device.

Therefore, the reaction liquid applying device 203 that applies the reaction liquid to the recording medium 208, the ink applying device 204 that applies ink to the recording medium 208, and the liquid absorbing member 205a that comes into contact with the first image on the recording medium 208 The liquid absorbing device 205 that absorbs the liquid component contained in the first image has the same configuration as the transfer type inkjet recording device, and the description thereof will be omitted.

In the direct drawing type inkjet recording device of the present embodiment, the liquid absorbing device 205 is a pressing member 205b for liquid absorption that presses the liquid absorbing member 205a and the liquid absorbing member 205a against the first image on the recording medium 208. Has. The shapes of the liquid absorbing member 205a and the pressing member 205b are not particularly limited, and those having the same shape as the liquid absorbing member and the pressing member that can be used in the transfer type inkjet recording device can be used. Further, the liquid absorbing device 205 may have a tensioning member for tensioning the liquid absorbing member. In FIG. 2, 205c, 205d, 205e, 205f, 205g are tension rollers as tension members. The number of tension rollers is not limited to the five shown in FIG. 4, and the required number may be arranged according to the device design. Further, a position facing the ink applying portion that applies ink to the recording medium 208 by the ink applying device 204 and the liquid component removing portion that presses the liquid absorbing member 205a against the first image on the recording medium to remove the liquid component. May be provided with a recording medium support member (not shown) that supports the recording medium from below.

<Recording medium transfer device>
In the direct drawing type inkjet recording device of the present embodiment, the recording medium transfer device 207 is not particularly limited, and the transfer device used in the known direct drawing type inkjet recording device can be used. As an example, as shown in FIG. 2, a recording medium transfer device having a recording medium feeding roller 207a, a recording medium winding roller 207b, and a recording medium transfer roller 207c, 207d, 207e, 207f can be mentioned.

<Control system>
The direct drawing type inkjet recording device in the present embodiment has a control system for controlling each device. The block diagram showing the control system of the entire device in the direct drawing type inkjet recording device shown in FIG. 2 is as shown in FIG. 3, similar to the transfer type inkjet recording device shown in FIG.

FIG. 5 is a block diagram of a printer control unit in the direct drawing type inkjet recording device shown in FIG. It is the same as the block diagram of the printer control unit in the transfer type inkjet recording apparatus shown in FIG. 4 except that the transfer body drive control unit 407 and the transfer body drive motor 408 are not provided.

That is, 501 is a CPU that controls the entire printer, 502 is a ROM for storing the control program of the CPU, and 503 is a RAM for executing the program. Reference numeral 504 is an ASIC having a built-in network controller, serial IF controller, head data generation controller, motor controller, and the like. Reference numeral 505 is a liquid absorbing member transport control unit for driving the liquid absorbing member transport motor 506, which is command controlled from the ASIC 504 via the serial IF. Reference numeral 509th is a head control unit, which generates final ejection data, drives voltage, and the like for the inkjet device 305.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples as long as it does not deviate from the gist thereof. In the description of the following examples, the term "part" is based on mass unless otherwise specified.

<Preparation of reaction solution>
As the reaction solution, a reaction solution having the composition shown below was used. The "remaining portion" of the ion-exchanged water is an amount in which the total of all the components constituting the reaction solution is 100.0% by mass.
・ Glutaric acid 21.0% by mass
・ Glycerin 5.0% by mass
-Surfactant (Mega Fvck F444 (trade name), manufactured by DIC Corporation) 5.0% by mass
・ Ion-exchanged water balance.

<Preparation of pigment dispersion>
Carbon black (Monac 1100 (trade name), manufactured by Cabot), 10 parts of resin aqueous solution (styrene-ethyl acrylate-acrylic acid copolymer, acid value 150, weight average molecular weight (Mw) 8,000, resin content 15 parts of a 20.0% by mass aqueous solution neutralized with a potassium hydroxide aqueous solution) and 75 parts of pure water were mixed. This mixed solution was charged into a batch type vertical sand mill (manufactured by Imex), filled with 200 parts of zirconia beads having a diameter of 0.3 mm, and subjected to a dispersion treatment for 5 hours while cooling with water. The dispersion was centrifuged to remove coarse particles to obtain a pigment dispersion having a pigment content of 10.0% by mass.

<Preparation of resin fine particle dispersion>
20 parts of ethyl methacrylate, 3 parts of 2,2'-azobis- (2-methylbutyronitrile), and 2 parts of n-hexadecane were mixed and stirred for 0.5 hours. This mixture was added dropwise to 75 parts of an 8% by mass aqueous solution of a styrene-butyl acrylate-acrylic acid copolymer (acid value: 130 mgKOH / g, weight average molecular weight (Mw): 7,000) for 0.5 hours. Stirred. Next, ultrasonic waves were irradiated with an ultrasonic irradiator for 3 hours. Subsequently, a polymerization reaction was carried out at 80 ° C. for 4 hours in a nitrogen atmosphere, and the mixture was cooled to room temperature and then filtered to prepare a resin fine particle dispersion having a resin content of 25.0% by mass.

<Ink preparation>
The pigment dispersion and the resin fine particle dispersion were mixed with the following components. The "remaining portion" of the ion-exchanged water is an amount in which the total of all the components constituting the ink is 100.0% by mass.
-Pigment dispersion 40.0% by mass
-Resin fine particle dispersion 20.0% by mass
・ Glycerin 7.0% by mass
-Polyethylene glycol (number average molecular weight (Mn): 1,000) 3.0% by mass
-Surfactant: acetylenol E100 (trade name, manufactured by Kawaken Fine Chemical Co., Ltd.) 0.5% by mass
-Ion-exchanged water balance After sufficiently stirring and dispersing the mixture, pressure filtration was performed with a microfilter (manufactured by FUJIFILM Corporation) having a pore size of 3.0 μm to prepare ink.

<Preparation of porous body>
Each layer shown in Table 1 was prepared as the first layer. The first layer is a porous body made of polytetrafluoroethylene (PTFE) having an average pore diameter of 0.2 μm on the surface in contact with the first image, and is a multiaxially stretched film. For example, the first layer in Example 1 was prepared by a method of obtaining a fibrillated porous body by compression molding crystallized PTFE emulsion particles and multiaxially stretching them at a temperature equal to or lower than the melting point of PTFE. .. The softening temperature was measured from the peak value of the heat absorption amount obtained by using a DSC measuring device (Q-1000 (trade name), manufactured by TA Instruments Japan Co., Ltd.).

Each layer shown in Table 2 was prepared as the second layer. The second layer in Examples 1 to 3, Examples 5 and Comparative Examples 1 to 4 contains a second fiber having a core structure made of polypropylene (PP) and a sheath structure made of polyethylene (PE). The HOP series (trade name, made by Hirose Paper Co., Ltd.) was used. The second layer in Example 5 has a second layer a containing the second fiber a and a second layer b containing the second fiber b. The average fiber diameter of the second fiber a is 5 μm, the average fiber diameter of the second fiber b is 15 μm, and the second fiber a contained in the second layer a arranged on the first layer side is twisted. The second fiber b contained in the second layer b, which is thin and arranged on the third layer side, is made thicker. The second layer in Example 4 is 15CN-70 (trade name) containing a second fiber having a core structure made of polyethylene terephthalate (PET) and a sheath structure made of copolymerized polyethylene terephthalate (CO-PET). , Made by Hirose Paper Co., Ltd.) was used.

Each layer shown in Table 3 was prepared as the third layer. As the third layer in Examples 1 to 5 and Comparative Examples 1 to 3, the non-woven fabric "PPS paper" (trade name) produced by wet papermaking of polyphenylene sulfide (PPS) fiber "torque converter" (trade name, manufactured by Toray Industries, Inc.). , Made by Hirose Paper Co., Ltd.) was used. As the third layer in Comparative Example 4, a non-woven fabric obtained by forming a polyethylene resin so as to satisfy the physical characteristics of Table 3 by the melt blown method was used.

The first to third layers were welded by the laminator shown in FIG. Specifically, after laminating the first layer and the second layer, a third layer was further laminated to prepare a porous body. In each laminating step, the heating temperature was adjusted to be between 140 and 150 ° C.

<Inkjet recording device and image formation>
The transfer type inkjet recording apparatus shown in FIG. 1 was used. The transfer body 101 is fixed to the surface of the support member 102 with double-sided tape. A sheet obtained by coating a PET sheet having a thickness of 0.5 mm with silicone rubber (trade name: 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 101. Further, a condensate obtained by mixing glycidoxypropyltriethoxysilane and methyltriethoxysilane at a molar ratio of 1: 1 and heating under reflux, and a photocationic polymerization initiator (trade name: SP150, manufactured by ADEKA). A mixture with and was prepared. The atmospheric pressure plasma treatment was performed so that the contact angle of water on the surface of the elastic layer was 10 degrees or less. Then, the mixture is applied onto the elastic layer, and a film is formed by UV irradiation (high pressure mercury lamp, integrated exposure amount: 5000 mJ / cm ² ) and thermosetting (150 ° C., 2 hours), and the thickness is formed on the elastic layer. A transfer body 101 having a surface layer having a thickness of 0.5 μm was prepared. The surface of the transfer body 101 was maintained at 60 ° C. by a heating device (not shown).

The amount of the reaction solution applied by the reaction solution application device 103 was 1 g / m ² . For the ink applying device 104, an inkjet recording head that uses an electric-heat conversion element to eject ink by an on-demand method was used. The amount of the ink applied in the image formation was 20 g / m ² .

The liquid absorbing member 105a has the porous body on the side in contact with the first image. By applying the pressure with the pressing member 105b, the nip pressure between the transfer body 101 and the liquid absorbing member 105a was adjusted to an average of 2 kgf / cm ² . The diameter of the pressing member 105b was 200 mm.

The transport speed of the liquid absorbing member 105a was adjusted to be equivalent to the moving speed of the transfer body 101 by the tension rollers 105c, 105d and 105e that transport the liquid absorbing member 105a while stretching it. Further, the recording medium 108 was conveyed by the recording medium feeding roller 107a and the recording medium winding roller 107b so as to have a speed equivalent to the moving speed of the transfer body 101. The transport speed of the recording medium 108 was set to 0.2 m / s. As the recording medium 108, Aurora-coated paper (manufactured by Nippon Paper Industries, Ltd., basis weight 104 g / m ² ) was used.

[Evaluation]
The inkjet recording apparatus obtained in each Example and each Comparative Example was evaluated by the following evaluation method. The evaluation results are shown in Table 4. In the present invention, A and B of the evaluation criteria of each of the following evaluation items are set to preferable levels, and C and D are set to unacceptable levels.

<Crushed eyes in the second layer>
The cross section of the porous body was observed with a metallurgical microscope and SEM, and the crushing of the second layer was confirmed. The evaluation criteria are as follows.
A: No blindness was confirmed.
B: Eye crushing was confirmed, but it was acceptable.
C: Eye crushing was confirmed and was unacceptable.

<Transport strength>
By applying a tension of 0.5 N per 1 mm of width of the liquid absorbing member 105a to transport and drive the liquid absorbing member 105a, it was confirmed whether or not peeling occurred between each layer of the porous body. The evaluation criteria are as follows.
A: Delamination did not occur.
B: Delamination occurred slightly, but it was acceptable.
C: Delamination occurred and was unacceptable.
D: The liquid absorbing member 105a was stretched due to tension, and the liquid absorbing member 105a could not be conveyed.

<Image flow>
For the examples and comparative examples that were A or B in the evaluation of the blinding of the second layer and the transport strength, the coloring material at the edge of the image after absorbing the first liquid in the image formation. The amount of movement, that is, the image flow was observed. The evaluation criteria are as follows.
A: No image flow was observed even after repeated use.
B: There was a slight image flow, but it was not noticeable.
C: The image flow was large.

<Adhesion of coloring material>
For the examples that were A or B in the evaluation of the blinding of the second layer, the transport strength, and the image flow, the liquid after the contact of the liquid absorbing member 105a with the first image in the image formation. Adhesion of the coloring material to the absorbing member 105a was observed. The evaluation criteria are as follows.
A: No colorant adhesion was observed.
B: Slight colorant adhesion was observed, but it was not noticeable.
C: A lot of colorant adhesion was observed.

Regarding the evaluation of the blinding of the second layer, in Examples 1 to 5 and Comparative Examples 1 to 3, the second layer contains the second fiber having a core-sheath structure, and the first and third layers No crushing was confirmed because a material with a high softening temperature was used. On the other hand, in Comparative Example 4, since the third fiber made of PE was used for the third layer, when the sheath material (PE) of the second fiber was melted, the third layer was also melted and the second layer was melted. Since the material of the third layer easily entered the scabbard, some crushing was confirmed. However, the blinding was acceptable.

Regarding the evaluation of the transport strength, in Comparative Examples 2 and 3, peeling occurred between the second layer and the third layer. Further, in Comparative Example 4, since the material of the third fiber in the third layer for ensuring the rigidity was PE, the liquid absorbing member 105a was significantly stretched at the stage when the transport tension was applied, resulting in plastic deformation. did. As a result, the liquid absorbing member 105a could not be conveyed.

Regarding the evaluation of image flow, when the cross section of the porous body of Comparative Example 1 was observed by SEM, PE, which is the sheath material of the second fiber, penetrated so as to fill the inside of the pores of the first layer. It was confirmed that the hole in one layer was closed. It is presumed that this caused image flow.

Regarding the evaluation of the adhesion of the coloring material, better results were obtained in Example 5 than in Examples 1 to 4. It is presumed that this is because the average fiber diameter of the second fiber a is smaller than the average fiber diameter of the second fibers of Examples 1 to 4, and the unevenness of the surface of the first layer is suppressed.

Moreover, the same experiment was performed using the direct drawing type inkjet recording apparatus shown in FIG. In the image formation by the direct drawing type inkjet recording apparatus shown in FIG. 2, Gloria Pure White paper basis weight 210 g / m ² (manufactured by Gojo Paper Manufacturing Co., Ltd.) was used as the recording medium 208. Other than the recording medium 208, the reaction solution, the reaction solution applying device 203, the ink, the ink applying device 204, the transport speed of the recording medium 208, and the liquid absorbing device 205 are the same as those of the transfer type inkjet recording device in the first embodiment. It was evaluated in the same manner as 1. As a result, it was confirmed that the same evaluation result as in Example 1 was obtained.

21 First layer 31 Third layer 32 Third fiber 41 Second layer 41a Second layer a
41b Second layer b
42, 42a, 42b Core structure 43, 43a, 43b Sheath structure 44 Second fiber 44a Second fiber a
44b Second fiber b
d1, d1a, d1b Average diameter of core structure d2 Average fiber diameter of second fiber d2a Average fiber diameter of second fiber a d2b Average fiber diameter of second fiber b d3 Average fiber diameter of third fiber t1 First Thickness of one layer t2, t2a, t2b Average thickness of sheath structure

Claims (12)

An image forming unit that forms a first image containing a first liquid and a coloring material on a recording object, and an image forming unit.
A liquid absorbing member having a porous body that comes into contact with the first image and absorbs at least a part of the first liquid from the first image.
It is an inkjet recording device equipped with
The porous body
With the first layer in contact with the first image,
With a second layer containing the second fiber,
With a third layer containing the third fiber,
Is a porous sheet in which the first layer, the second layer, and the third layer are all porous layers.
The average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber.
The second fiber has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure.
The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. Lower than either
An inkjet recording apparatus characterized in that the average thickness of the sheath structure is smaller than the thickness of the first layer. An image forming unit that forms a first image containing a first liquid and a coloring material on a recording object, and an image forming unit.
A liquid absorbing member having a porous body that comes into contact with the first image and absorbs at least a part of the first liquid from the first image.
It is an inkjet recording device equipped with
The porous body
With the first layer in contact with the first image,
A second layer a containing the second fiber a and
A second layer b containing the second fiber b and
With a third layer containing the third fiber,
Is a porous sheet in which the first layer, the second layer a, the second layer b, and the third layer are all porous layers.
The average fiber diameter of the second fiber b is larger than the average fiber diameter of the third fiber.
The second fiber a and the second fiber b have a core-sheath structure having a core structure forming a central axis and a sheath structure wrapping the core structure.
The softening temperature of the material forming the sheath structure of the second fiber a is higher than the softening temperature of the material forming the core structure of the second fiber a or the softening temperature of the material forming the first layer. Also low,
The softening temperature of the material forming the sheath structure of the second fiber b is higher than the softening temperature of the material forming the core structure of the second fiber b or the softening temperature of the material forming the third fiber. Also low,
An inkjet recording apparatus characterized in that the average thickness of the sheath structure of the second fiber a is smaller than the thickness of the first layer. The inkjet recording apparatus according to claim 1 or 2, wherein the Young's modulus of the material forming the third fiber is higher than the Young's modulus of the material forming the first layer. The inkjet recording apparatus according to any one of claims 1 to 3, wherein the average pore diameter on the surface of the first layer on the side in contact with the first image is 0.2 μm or less. The inkjet recording apparatus according to any one of claims 1 to 4, wherein the first layer contains a fluororesin. The inkjet recording apparatus according to any one of claims 1 to 5, wherein the third fiber contains polyphenylene sulfide or polyimide. The image forming unit is
Wherein the first liquid member, a device for applying a first liquid composition onto the recording material comprising an ink viscosity increasing component,
Wherein the first liquid member, a device for applying a second liquid composition comprising said colorant onto the recording member,
Including
The first image is a mixture of the first and second liquid compositions, which is any one of claims 1 to 6, which is more viscous than any of the first and second liquid compositions. The inkjet recording apparatus according to the section. The recorded body is a transfer body that temporarily holds the first image and the second image obtained by absorbing the first liquid from the first image.
The inkjet recording apparatus according to any one of claims 1 to 7, further comprising a transfer unit including a transfer pressing member for transferring the second image onto a recording medium on which an image should be formed. The inkjet recording apparatus according to any one of claims 1 to 7, wherein the recorded object is a recording medium on which an image should be formed. An image forming unit that forms a first image by applying ink containing a first liquid and a coloring material onto a recording object,
A liquid absorbing member having a porous body that comes into contact with the first image and concentrates the ink constituting the first image.
It is an inkjet recording device equipped with
The porous body
With the first layer in contact with the first image,
With a second layer containing the second fiber,
With a third layer containing the third fiber,
Is a porous sheet in which the first layer, the second layer, and the third layer are all porous layers.
The average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber.
The second fiber has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure.
The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. Lower than either
An inkjet recording apparatus characterized in that the average thickness of the sheath structure is smaller than the thickness of the first layer. An image forming unit that forms a first image containing a first liquid and a coloring material on a recording object, and an image forming unit.
A liquid absorbing member having a porous body that comes into contact with the first image and absorbs at least a part of the first liquid from the first image.
It is a method for producing a porous body used in an inkjet recording apparatus including the above.
By heating the first layer in contact with the first image, the second layer containing the second fiber, and the third layer containing the third fiber in this order, the layers are heated. It has a step of forming a porous body having the first layer, the second layer, and the third layer.
The first layer, the second layer, and the third layer are all porous layers.
The average fiber diameter of the second fiber is larger than the average fiber diameter of the third fiber.
The second fiber has a core-sheath structure having a core structure forming a central axis and a sheath structure surrounding the core structure.
The softening temperature of the material forming the sheath structure is the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber. Lower than either
The average thickness of the sheath structure is smaller than the thickness of the first layer,
The heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure, and the softening temperature of the material forming the core structure, the softening temperature of the material forming the first layer, and the third A method for producing a porous body, which is characterized by having a temperature equal to or lower than the softening temperature of the material forming the fiber. An image forming unit that forms a first image containing a first liquid and a coloring material on a recording object, and an image forming unit.
A liquid absorbing member having a porous body that comes into contact with the first image and absorbs at least a part of the first liquid from the first image.
It is a method for producing a porous body used in an inkjet recording apparatus including the above.
A first layer in contact with the first image, a second layer a containing a second fiber a, a second layer b containing a second fiber b, and a third containing a third fiber. By heating the layers in this order in a laminated state, a porous body having the first layer, the second layer a, the second layer b, and the third layer. Has a process of forming
The first layer, the second layer a, the second layer b, and the third layer are all porous layers.
The average fiber diameter of the second fiber b is larger than the average fiber diameter of the third fiber.
The second fiber a and the second fiber b have a core-sheath structure having a core structure forming a central axis and a sheath structure wrapping the core structure.
The softening temperature of the material forming the sheath structure of the second fiber a is higher than the softening temperature of the material forming the core structure of the second fiber a or the softening temperature of the material forming the first layer. Also low,
The softening temperature of the material forming the sheath structure of the second fiber b is higher than the softening temperature of the material forming the core structure of the second fiber b or the softening temperature of the material forming the third fiber. Also low,
The average thickness of the sheath structure of the second fiber a is smaller than the thickness of the first layer.
The heating temperature is equal to or higher than the softening temperature of the material forming the sheath structure of the second fiber a and the second fiber b, and the core of the second fiber a and the second fiber b. A method for producing a porous body, which is equal to or lower than the softening temperature of the material forming the structure, the softening temperature of the material forming the first layer, and the softening temperature of the material forming the third fiber.

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