JP2021094730A - Inkjet recording method and inkjet recording device - Google Patents

Abstract

To provide an inkjet recording method which can record a high-quality image that suppresses adhesion of a coloring material to a porous layer of a liquid absorption member, is excellent in transferability of an image onto a recording medium and suppresses chipping.SOLUTION: An inkjet recording method records an image onto a recording medium using aqueous ink. The inkjet recording method includes: a reaction liquid imparting step of imparting aqueous reaction liquid onto a transfer body; an ink imparting step of imparting aqueous ink containing a resin having an anionic group and a coloring material; a transfer promotion liquid imparting step of imparting aqueous transfer promotion liquid containing an ampholytic surface active agent, to form an intermediate image; a liquid absorption step of bringing a porous layer into contact with the intermediate image, and absorbing at least a part of the liquid component from the intermediate image; and a transfer step of bringing the intermediate image into contact with the recording medium and transferring the intermediate image thereto.SELECTED DRAWING: None

Description

The present invention relates to an inkjet recording method and an inkjet recording device.

Water-based inks are widely used as inks used in inkjet recording methods. In order to quickly remove the liquid component in the ink, for example, there is a method of drying the ink applied to the recording medium with warm air, infrared rays, or the like to record an image. Further, there is also known a method of recording an image by transferring it to a recording medium after removing a liquid component by applying thermal energy or the like to an intermediate image formed by applying water-based ink to a transfer body.

As a method of using the transfer body, a treatment liquid for rapidly aggregating the ink is applied to the ink applied on the transfer body to form an intermediate image, and then the porous layer is brought into contact with the liquid component in the intermediate image. An inkjet recording method including a removing step has been proposed (Patent Document 1).

JP-A-2009-96187

According to the inkjet recording method proposed in Patent Document 1, an image can be recorded while suppressing the coloring material in the ink from adhering to the porous layer. However, as a result of examination by the present inventors, it has been found that a part of the image transferred to the recording medium is likely to be defective. When a treatment liquid that rapidly agglomerates the intermediate image is used, the intermediate image tends to become excessively hard. For this reason, the hardened intermediate image does not sufficiently contact the recording medium having large surface irregularities, and a part of the intermediate image remains on the transfer body, which makes it easy for defects such as white spots to occur in the image. Conceivable.

Therefore, an object of the present invention is to record a high-quality image in which the adhesion of the coloring material to the porous layer of the liquid absorbing member is suppressed, the transferability of the image to the recording medium is excellent, and defects are suppressed. It is to provide an inkjet recording method which can be performed. Another object of the present invention is to provide an inkjet recording apparatus used in this inkjet recording method.

That is, according to the present invention, it is an inkjet recording method for recording an image on a recording medium using a water-based ink, and a reaction liquid for imparting an aqueous reaction liquid containing a reactant that reacts with the water-based ink to a transfer body. The applying step, the ink applying step of applying the water-based ink containing the resin having an anionic group and the coloring material to the region to which the reaction liquid of the transfer body is applied, and the water-based ink of the transfer body are applied. A transfer-promoting liquid application step of applying an aqueous transfer-promoting liquid containing an amphoteric surfactant to the formed region to form an intermediate image, and the porous layer of the liquid absorbing member provided with the porous layer are intermediate. A liquid absorption step of contacting with an image to absorb at least a part of a liquid component from the intermediate image, and a transfer step of bringing the intermediate image with at least a part of the liquid component absorbed into contact with the recording medium and transferring the image. And, an inkjet recording method characterized by having.

According to the present invention, it is possible to record a high-quality image in which adhesion of a coloring material to the porous layer of a liquid absorbing member is suppressed, the transferability of the image to a recording medium is excellent, and defects are suppressed. Can provide an inkjet recording method capable of Further, according to the present invention, it is possible to provide an inkjet recording apparatus used in this inkjet recording method.

It is a schematic diagram which shows one Embodiment of the inkjet recording apparatus of this invention.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. In the present invention, when the compound is a salt, the salt is dissociated into ions and exists in the ink, but for convenience, it is expressed as "containing a salt". Further, the water-based reaction solution, the water-based ink, and the water-based transfer accelerator for inkjet may be simply referred to as "reaction solution", "ink", and "transfer accelerator". The physical characteristic value is a value at room temperature (25 ° C.) unless otherwise specified. When described as "(meth) acrylic acid" and "(meth) acrylate", they mean "acrylic acid, methacrylic acid" and "acrylate, methacrylate", respectively.

<Inkjet recording method and inkjet recording device>
The inkjet recording method of the present invention (hereinafter, also simply referred to as “recording method”) is a method of recording an image on a recording medium using water-based ink. The recording method of the present invention includes a reaction liquid applying step, an ink applying step, a transfer promoting liquid applying step, a liquid absorbing step, and a transfer step. The reaction solution applying step is a step of applying an aqueous reaction solution containing a reactant that reacts with ink to the transfer material, and the ink application step is a step of applying an anionic group to the region of the transfer body to which the reaction solution is applied. This is a step of applying ink containing the resin and coloring material to be possessed. The transfer-promoting liquid application step is a step of applying an aqueous transfer-promoting liquid containing an amphoteric surfactant to a region to which the ink of the transfer body has been applied to form an intermediate image. The liquid absorption step is a step of bringing the porous layer of the liquid absorbing member including the porous layer into contact with the intermediate image and absorbing at least a part of the liquid component from the intermediate image. The transfer step is a step of bringing an intermediate image in which at least a part of the liquid component is absorbed into contact with a recording medium and transferring the image. That is, the recording method of the present invention is a transfer type inkjet recording method. If necessary, the recording method of the present invention may further include a washing step of washing the transferred material after the transfer step.

Further, the inkjet recording apparatus of the present invention (hereinafter, also simply referred to as “recording apparatus”) is an apparatus used for recording an image on a recording medium using water-based ink. The recording device of the present invention includes a reaction liquid applying means, an ink applying means, a transfer promoting liquid applying means, a liquid absorbing means, and a transfer means. The reaction solution applying means is a means for applying an aqueous reaction solution containing a reactant that reacts with an ink to a transfer body, and the ink application means applies an anionic group to a region of the transfer body to which the reaction solution is applied. It is a means for applying an ink containing a resin and a coloring material. The transfer promoting liquid applying means is a means for forming an intermediate image by applying an aqueous transfer promoting liquid containing an amphoteric surfactant to a region to which the ink of the transfer body has been applied. The liquid absorbing means is a means for bringing the porous layer of the liquid absorbing member including the porous layer into contact with the intermediate image to absorb at least a part of the liquid component from the intermediate image, and the transfer means is a means for absorbing at least a part of the liquid component. This is a means for transferring a partially absorbed intermediate image by bringing it into contact with a recording medium. That is, the recording device of the present invention is a so-called transfer type inkjet recording device. The recording device of the present invention may further include cleaning means for cleaning the transferred body after transfer, if necessary.

As described above, according to the inkjet recording method proposed in Patent Document 1, adhesion of the coloring material to the porous layer of the liquid absorbing member that repeatedly contacts the intermediate image is suppressed, but the recorded image is defective. It was easy to occur. The present inventors have studied to suppress the adhesion of the coloring material to the porous layer and the suppression of the occurrence of defects in the recorded image.

When recording an image at high speed, the time until the porous layer of the liquid absorbing member comes into contact with the ink applied to the transfer body becomes very short, so the surface layer of the ink is at a stage where the reaction with the reaction liquid is insufficient. It will come into contact with the porous layer. Therefore, it is considered that a part of the coloring material in the ink with insufficient binding enters the porous layer together with the liquid component, and the coloring material adheres to the porous layer. Therefore, the present inventors suppress the adhesion of the coloring material to the porous layer by sufficiently reacting the reaction solution, the ink, and the transfer promoting solution before the porous layer comes into contact with the intermediate image. However, it was considered that the occurrence of image defects could be suppressed, and the present invention was reached.

An ink layer that gradually aggregates is formed on the transfer material to which the reaction solution and the ink are applied. On the surface side of the ink layer, there is a portion where aggregation is insufficient. In the recording method of the present invention, an aqueous transfer promoter containing an amphoteric surfactant is applied to the ink-applied region of the transfer body. As a result, the transfer accelerator comes into contact with the surface side of the ink layer having insufficient aggregation, so that the aggregation of the ink layer is promoted and the amphoteric tenside in the transfer accelerator is oriented toward the surface side of the ink layer. , The surface energy of the formed intermediate image is reduced. Therefore, even when the porous layer repeatedly contacts the intermediate image, it is considered that the coloring material is less likely to adhere to the porous layer.

However, if the intermediate image formed by applying the transfer accelerator on the ink layer is excessively aggregated and becomes too hard, it becomes difficult for the intermediate image to follow the irregularities on the surface of the recording medium during transfer, and the intermediate image becomes difficult to follow on the recording medium. Defects are likely to occur in the transferred image. That is, it is important that the intermediate image has both hardness that can suppress the adhesion of the coloring material to the porous layer and softness that can maintain the transferability. When a reaction solution containing a reactant is further applied to the ink layer, the ink layer is excessively aggregated, and it becomes difficult to maintain transferability. On the other hand, in the recording method of the present invention, since the transfer promoter containing the amphoteric surfactant is applied to the region to which the ink of the transfer body is applied, excellent transferability is maintained and defects occur. It is possible to record a suppressed high-quality image.

FIG. 1 is a schematic view showing an embodiment of the inkjet recording apparatus of the present invention. The transfer-type inkjet recording device 100 shown in FIG. 1 is an inkjet recording device that manufactures a recorded material by transferring an intermediate image to a recording medium 108 via a transfer body 101. The X direction, the Y direction, and the Z direction indicate the width direction (total length direction), the depth direction, and the height direction of the transfer type inkjet recording apparatus 100, respectively. The recording medium is conveyed in the X direction.

The transfer type inkjet recording device 100 includes a transfer body 101, a reaction liquid applying device 103, an ink and transfer promoting liquid applying device 104, a liquid absorbing device 105, and a pressing member 106. The transfer body 101 is supported by the support member 102. The reaction solution applying device 103 is an device that applies a reaction solution containing a reactant that reacts with ink to the transfer body 101. The ink and transfer accelerating liquid applying device 104 includes a recording head that applies the ink and the transfer accelerating liquid to the transfer body 101 to which the reaction liquid is applied, respectively, to form an intermediate image. The liquid absorbing device 105 is a device that absorbs a liquid component from an intermediate image. The pressing member 106 is a member for transferring an intermediate image from which the liquid component has been removed to a sheet-shaped recording medium 108 such as paper. Further, the transfer type inkjet recording apparatus 100 has a transfer body cleaning member 109 that cleans the surface of the transfer body 101 after transfer. The transfer body 101, the reaction liquid application device 103, the recording head of the ink and transfer accelerator application device 104, the liquid absorption device 105, and the transfer body cleaning member 109 each correspond only to the recording medium 108 used in the Y direction. Has a length of.

The transfer body 101 rotates in the direction of arrow A about the rotation axis 102a of the support member 102. After the reaction solution is applied to the rotating transfer body 101 from the reaction solution application device 103, the ink is applied from the ink and transfer accelerator application device 104 to form an intermediate image on the transfer body 101. The intermediate image formed on the transfer body 101 moves to a position where it comes into contact with the liquid absorption member 105a of the liquid absorption device 105 by the rotation of the transfer body 101.

The liquid absorbing member 105a constituting the liquid absorbing device 105 moves (rotates) in the direction of the arrow B in synchronization with the rotation of the transfer body 101. The intermediate image formed on the transfer body 101 comes into contact with the moving liquid absorbing member 105a. Meanwhile, the liquid absorbing member 105a absorbs and removes the liquid component from the intermediate image. From the viewpoint of efficiently absorbing the liquid component of the intermediate image, the liquid absorbing member 105a is preferably pressed against the transfer body 101 with a predetermined pressing force. The intermediate image is formed of a reaction solution, an ink, and a transfer promoting solution. Therefore, absorbing the liquid component of the intermediate image means absorbing the liquid component of the reaction solution, the ink, and the transfer promoting solution. It can be said that absorbing the liquid component from the intermediate image means concentrating the ink or the like. Concentration of ink and the like increases the ratio of solids such as coloring materials and resins to liquid components.

The intermediate image in which the liquid component is removed and the ink is concentrated is moved to the transfer unit 111 in contact with the recording medium 108 conveyed by the recording medium transfer device 107 by the rotation of the transfer body 101. The intermediate image and the recording medium 108 are pressed from the pressing member 106 side and come into contact with each other while being sandwiched between the transfer body 101 and the pressing member 106. When the roller-shaped transfer body 101 and the columnar pressing member 106 are used, the intermediate image and the recording medium 108 come into linear contact with each other along the Y direction. When the transfer body 101 made of an elastic material is used, the transfer body 101 is dented by pressing, so that the intermediate image and the recording medium 108 come into contact with each other on the surface. Therefore, the line or surface where the intermediate image and the recording medium 108 come into contact with each other is referred to as a "region", and the portion including this region is referred to as a transfer unit 111. While the intermediate image is in contact with the recording medium 108, the pressing member 106 presses the transfer body 101 to transfer the intermediate image to the recording medium 108, and the desired image is recorded on the recording medium 108. The image after transfer is an inverted image of the intermediate image before transfer.

When the reaction solution is applied to the transfer body using the roller-shaped reaction solution application member 103c, the reaction solution is applied to the entire transfer body. In order to further apply the ink to the transfer body to which the reaction solution has been applied, the reaction solution that has not reacted with the ink remains in the region of the transfer body to which the ink has not been applied. The liquid absorbing member 105a can remove not only the liquid component of the unreacted reaction liquid but also the liquid component of the unreacted reaction liquid from the intermediate image. The liquid component contained in the ink or the transfer promoting liquid does not have a certain shape but has fluidity and exists in a substantially constant volume. Specifically, the liquid component contained in the ink or the transfer promoting liquid is an aqueous medium or the like.

Hereinafter, the main parts of the transfer type inkjet recording apparatus will be described. Specifically, [1] transfer body, [2] support member, [3] reaction liquid application device, [4] ink and transfer accelerator application device, [5] liquid absorption device, [6] pressing member, [7] A recording medium, [8] a recording medium transport device, and [9] a cleaning device will be described.

[1] Transfer The transfer body 101 has a surface layer including a surface on which an intermediate image is formed. Examples of the material constituting the surface layer include resin and ceramic. From the viewpoint of durability and the like, a material having a high compressive elastic modulus is preferable. In order to improve the wettability of the reaction solution, the ink, and the transfer accelerator, the surface treatment may be applied before use.

The transfer material preferably has a compression layer having a function of absorbing pressure fluctuations between the surface layer and the support member. The compression layer disperses local pressure fluctuations and absorbs deformation of the surface layer. Therefore, by providing the compression layer, good transferability can be maintained even in the case of high-speed recording. Examples of the material constituting the compression layer include an elastic material such as a rubber material. Among them, a rubber material having a porous structure formed by blending a filler such as a foaming agent, hollow fine particles, and a salt with a vulcanizing agent and a vulcanization accelerator into a raw material rubber is preferable. In such an elastic material, when the pressure fluctuates, the void portion is compressed with a volume change, so that the deformation in the direction other than the compression direction is small. Therefore, transferability and durability can be improved. Examples of the porous structure include a continuous void structure in which voids are interconnected and an independent void structure in which the voids are independent of each other.

The transfer material preferably has an elastic layer between the surface layer and the compression layer. Examples of the material constituting the elastic layer include a resin material and a ceramic material. Among them, an elastic material such as a rubber material is preferable because it is easy to process, the change in elastic modulus with temperature is small, and the transferability is excellent.

The layers (surface layer, elastic layer, compression layer) constituting the transfer body can be adhered to each other by using an adhesive or double-sided tape. A reinforcing layer having a high compressive elastic modulus may be provided in order to suppress lateral elongation when mounted on the device and maintain elasticity. As the reinforcing layer, a woven cloth or the like can be used. Of the layers constituting the transfer body, the elastic layer and the compression layer can be arbitrarily combined for the layers other than the surface layer. The size of the transfer body can be freely selected according to the recording speed and the size of the image. Examples of the shape of the transfer body include a sheet shape, a roller shape, a belt shape, an endless web shape, and the like.

[2] Support member The transfer body 101 is supported on the support member 102. The transfer body can be arranged on the support by using, for example, an adhesive or double-sided tape. The transfer body 101 may be arranged on the support member 102 by using an installation member made of a material such as metal, ceramic, or resin. The support member 102 is required to have a certain level of structural strength from the viewpoint of transport accuracy and durability. Examples of the material of the support member include metal, ceramic, and resin. Of these, it is preferable to use a metal material such as aluminum. By using a metal material, it is possible to improve the responsiveness of control by reducing the inertia during operation as well as the rigidity and dimensional accuracy that can withstand the stress during transfer.

[3] Reaction Solution Applying Device The recording method of the present invention includes a reaction solution applying step of applying the reaction solution to the transfer material before the ink applying step. The reaction solution contains a reactant that reacts with the ink when it comes into contact with the ink and aggregates components having anionic groups such as a resin and a self-dispersing pigment in the ink. After applying the ink, the reaction solution may be further applied so that at least a part of the area to which the ink is applied overlaps.

The transfer-type inkjet recording device 100 shown in FIG. 1 has a reaction solution applying device 103 which is a reaction solution applying means for applying the reaction solution to the transfer body 101. The reaction solution application device 103 is a gravure offset roller having a reaction solution accommodating unit 103a for accommodating the reaction solution and reaction solution application members 103b and 103c for applying the reaction solution in the reaction solution accommodating unit 103a to the transcript 101. .. Examples of the reaction liquid applying device include a gravure offset roller and an inkjet recording head. Above all, it is preferable to apply the reaction solution to the transcript using a roller.

[4] Ink and Transfer Accelerating Liquid Applying Device The transfer type inkjet recording device 100 shown in FIG. 1 has an ink and transfer promoting liquid applying device 104 which is an applying means for applying ink and transfer promoting liquid to the transfer body 101. .. It is preferable to use an inkjet recording head as an ink applying device and eject and apply ink. Further, the transfer accelerator liquid is ejected and applied by using an inkjet recording head as in the case of ink. The recording head is, for example, 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; an ink using static electricity. The form of discharging the ink can be mentioned. Among them, a recording head in the form of using an electric-heat converter is preferable because it can record a high-density image at a higher speed.

The region for applying the transfer promoting liquid to the transfer body preferably includes at least a region for applying the ink. That is, it is preferable to apply the ink and the transfer accelerator in layers. Of course, the transfer accelerator may be applied to the region of the transfer body to which the ink is not applied. The application amount ratio per unit area in the region where the ink and the transfer accelerator are applied is 0.1 times or more and 10.0 times or less in terms of the mass ratio of the ink application amount to the transfer accelerator application amount. Is preferable.

The recording head is a full-line head extending in the Y direction, and the discharge ports are arranged in a range covering the width of the image recording area of the maximum usable recording medium. The recording head has a discharge port surface having a discharge port opened on its lower surface (transfer body 101 side). The discharge port surface faces the surface of the transfer body 101 with a minute gap (about several millimeters).

The ink and transfer accelerator application device 104 has a plurality of recording heads for applying ink of each color such as cyan, magenta, yellow, and black (CMYK), and the transfer accelerator to the transfer body 101. May be good. For example, when forming an intermediate image using four types of CMYK inks and a transfer promoting liquid, the ink applying device has five recording heads for ejecting each of the four types of CMYK inks and the transfer promoting liquid. These recording heads are arranged along the X direction.

[5] Liquid Absorbing Device The liquid absorbing device 105 includes a liquid absorbing member 105a and a pressing member 105b for liquid absorbing that presses the liquid absorbing member 105a against the intermediate image of the transfer body 101. The liquid absorbing member 105a includes a porous layer that can come into contact with the intermediate image on the transfer body 101. When composed of a columnar pressing member 105b and a belt-shaped liquid absorbing member 105a, the pressing member 105b presses the porous layer of the liquid absorbing member 105a against the transfer body 101 to absorb the liquid component from the intermediate image. be able to. Further, the liquid component can be absorbed from the intermediate image by pressing the columnar pressing member having the liquid absorbing member attached to the outer peripheral surface against the transfer body. Considering the space in the recording device, the shape of the liquid absorbing member 105a is preferably a belt shape. The liquid absorbing device 105 having the belt-shaped liquid absorbing member 105a may have a tensioning member such as a tensioning roller 105c that stretches the liquid absorbing member 105a.

By bringing the porous layer of the liquid absorbing member 105a into contact with the intermediate image using the pressing member 105b, the liquid component contained in the intermediate image can be absorbed by the liquid absorbing member 105a (porous layer). As a method of absorbing the liquid component contained in the intermediate image, in addition to the method of contacting the porous layer of the liquid absorbing member, a method of heating, a method of blowing low humidity air, a method of reducing the pressure, and the like may be combined. In addition, these methods may be applied to the intermediate images before and after absorbing the liquid component.

The liquid absorbing member 105a rotates in conjunction with the rotation of the transfer body 101. Therefore, the shape of the liquid absorbing member 105a is preferably a shape capable of repeatedly absorbing liquid, and specific examples thereof include an endless belt shape and a drum shape. The liquid component absorbed by the liquid absorbing member 105a provided with the porous layer can be absorbed from the back surface of the porous layer, or by using a member that squeezes the porous layer by compressing it, or the like. Can be removed from. After removing the liquid component, the liquid absorbing member 105a is rotated to bring it into contact with the new intermediate image, so that the liquid component contained in the intermediate image can be efficiently absorbed.

It is preferable that the porous layer is thin in order to uniformly obtain high air permeability. The air permeability of the porous layer can be indicated by the Gale value specified in JIS P8117: 2009. The galley value of the porous layer is preferably 1 second or more and 10 seconds or less. However, if the porous layer is made too thin, it may not be possible to secure a sufficient amount of voids necessary for absorbing the liquid component. The porous layer may have a laminated structure in which a plurality of layers are laminated. The liquid absorbing member may be any part as long as the part in contact with the intermediate image is porous, and the part not in contact with the intermediate image may not be porous.

When the porous layer has a laminated structure, the porous layer in contact with the intermediate image is defined as the first layer, and the layer laminated on the surface side opposite to the intermediate image of the first layer is described as the second layer. To do. In the case of a multi-layer structure having three or more layers, the first layer, the second layer, the third layer, and so on are used in the order of stacking from the first layer. The first layer is also referred to as an "absorption layer", and the second and subsequent layers are also referred to as a "support layer".

As the material constituting the first layer, both a hydrophilic material having a contact angle with water of less than 90 ° and a water-repellent material having a contact angle of 90 ° or more can be used. Examples of the hydrophilic material include a single material such as cellulose and polyacrylamide, and a composite material thereof. Further, the surface of the water-repellent material can be hydrophilized before use. The hydrophilic treatment, sputter etching, irradiation, H 2 _O ion irradiation, may be a method such as an excimer (UV) laser irradiation.

The contact angle of the hydrophilic material with water is preferably 60 ° or less. In the case of a hydrophilic material, the capillary force causes an action of sucking up a liquid component such as water. On the other hand, in order to suppress the adhesion of the coloring material to the first layer and to improve the cleaning property, the material of the first layer may be a water-repellent material such as a fluororesin having a low surface free energy. preferable. When a water-repellent material is used, it may take time to absorb the liquid component because the action of sucking up the liquid component hardly occurs due to the capillary force. Therefore, it is preferable that the first layer is impregnated with a treatment liquid having a contact angle with the first layer of less than 90 °. The treatment liquid preferably contains water and a water-soluble organic solvent. As the water-soluble organic solvent, ethanol, isopropyl alcohol and the like can be used. The treatment liquid may further contain a surfactant or a liquid having a small contact angle with the first layer.

The thickness of the first layer is preferably 50 μm or less, and more preferably 1 μm or more and 30 μm or less. For the thickness of the first layer, measure the thickness of any 10 points using a device such as a Digimatic straight-ahead outer micrometer (trade name "OMV-25MX", manufactured by Mitutoyo), and calculate the average value. It can be obtained by calculating.

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

The second layer is preferably breathable. For example, the second layer can be made of a non-woven fabric or woven fabric made of resin fibers. As the material of the second layer, a material having a contact angle with the ink equal to or less than that of the first layer is preferable so that the liquid component absorbed in the first layer does not flow back. For example, olefin resin, urethane resin and the like can be mentioned. The pore size of the second layer is preferably larger than the pore size of the first layer.

The third and subsequent layers are preferably made of a non-woven fabric from the viewpoint of rigidity and the like. As the material of the non-woven fabric, an olefin resin, a urethane resin, or the like can be used as in the case of the non-woven fabric constituting the second layer.

The liquid absorbing member may have a reinforcing member for reinforcing the side surface of the liquid absorbing member as a constituent member other than the porous layer. Further, it may have a joining member for connecting the longitudinal end portions of a long sheet-shaped porous layer to form a belt-shaped member. As the reinforcing member and the joining member, a non-porous tape material or the like can be used.

In order to produce a porous layer having a laminated structure, a plurality of layers may be simply laminated, or may be adhered with an adhesive or heat. From the viewpoint of breathability, it is preferable to bond the plurality of layers by heat. Further, a part of the layer may be melted and adhered by heating. Further, a fusion material such as hot melt powder may be heated and adhered in a state of being interposed between the layers. When laminating the third and subsequent layers, they may be laminated at once or sequentially. When heating to bond the plurality of layers, it is preferable to heat while pressurizing with a heated roller.

[6] Pressing Member The recording device of the present invention includes a transfer means for transferring an intermediate image in contact with a recording medium. Specifically, as shown in FIG. 1, the intermediate image after removing the liquid on the transfer body 101 is brought into contact with the recording medium 108 conveyed by the recording medium transfer device 107 by the pressing member 106 at the transfer unit 111 to be transferred. To do. By transferring the intermediate image after removing the liquid component to the recording medium 108, curling and cockling of the recording medium 108 can be suppressed.

The pressing member 106 preferably has an appropriate structural strength from the viewpoint of transport accuracy and durability of the recording medium 108. Examples of the material of the pressing member 106 include metal, ceramic, and resin. Among them, a metal such as aluminum is preferable from the viewpoint of not only having rigidity and dimensional accuracy that can withstand stress during transfer, but also reducing inertia during operation and improving control responsiveness.

When the intermediate image is transferred to the recording medium 108, the time (pressing time) for the pressing member 106 to press the transfer body 101 is preferably 5 ms or more and 100 ms or less. By setting the pressing time as described above, transfer can be performed satisfactorily and damage to the transfer body 101 can be suppressed. The pressing time is the time during which the recording medium 108 and the transfer body 101 are in contact with each other. The pressing time can be calculated by measuring the surface pressure using a pressure distribution measuring system and dividing the length of the pressurized region in the transport direction by the transport speed. Specifically, a surface pressure distribution measurement system (trade name "I-SCAN", manufactured by Nitta Corporation) or the like can be used.

When the intermediate image is transferred to the recording medium 108, the pressure (pressing pressure) at which the pressing member 106 presses the transfer body 101 is 9.8 N / cm ² (1 kg / cm ² ) or more and 294.2 N / cm ² (30 kg). / Cm ² ) or less is preferable. By applying the above pressing pressure, transfer can be performed satisfactorily and damage to the transfer body 101 can be suppressed. The pressing force is the nip pressure of the recording medium 108 and the transfer body 101. The pressing force can be calculated by measuring the surface pressure using a pressure distribution measuring system and dividing the load in the pressurized region by the area. Specifically, a surface pressure distribution measurement system (trade name "I-SCAN", manufactured by Nitta Corporation) or the like can be used.

The temperature of the intermediate image at the position where the pressing member 106 presses the transfer body 101 is preferably a temperature equal to or higher than the glass transition point (or softening point) of the resin component contained in the intermediate image. Among them, the temperature at the time of pressing and transferring is preferably 25 ° C. or higher and 140 ° C. or lower, and more preferably 40 ° C. or higher and 140 ° C. or lower. In order to control the temperature, the recording device preferably includes a heating means for heating the intermediate image on the transfer body 101, the transfer body 101, and the recording medium 108. Examples of the shape of the pressing member 106 include a roller shape and the like.

[7] Recording medium As the recording medium 108, any known recording medium can be used. Examples of the recording medium include a long object wound in a roll shape; a single-wafer object cut into a predetermined size, and the like. Examples of the constituent material of the recording medium include paper such as coated paper and plain paper; film such as plastic and metal; wooden board; corrugated cardboard and the like.

[8] Recording medium transport device The recording medium transport device 107 that transports the recording medium 108 transports the recording medium 108 in the direction of arrow C. The recording medium conveying device 107 is composed of a recording medium feeding roller 107a and a recording medium winding roller 107b. The transport speed of the recording medium 108 is preferably determined in consideration of the speed required in each step.

[9] Cleaning device As shown in FIG. 1, it is preferable that the recording device of the present invention has a cleaning device which is a cleaning means for applying an aqueous cleaning liquid to the transfer body 101 for cleaning. The cleaning device includes, for example, a transfer body cleaning member 109 that applies a cleaning solution to the transfer body 101 to clean the transfer body 101. By cleaning the transfer body 101 with the transfer body cleaning member 109, deterioration of image quality can be suppressed. As the transfer body cleaning member 109, a member having a shape such as a roller or a web can be used. The cleaning device may be provided with a cleaning liquid supply unit that supplies the cleaning liquid to the transfer body cleaning member 109.

Further, the cleaning device preferably includes a cleaning liquid removing member 110 for removing the cleaning liquid and residues remaining on the transfer body 101 after cleaning. By removing the cleaning liquid and the like remaining on the transfer body 101 by the cleaning liquid removing member 110, deterioration of image quality can be suppressed more effectively. Examples of the method for removing the cleaning liquid remaining on the transfer body 101 include blade removal, brush removal, and liquid absorption by the absorber. Above all, it is preferable to remove the cleaning liquid remaining on the transfer body 101 by the liquid absorption by the absorber. As the cleaning liquid removing member 110, a porous layer or the like used as a liquid absorbing member can be used.

(Reaction solution)
The recording method of the present invention includes a reaction solution applying step of applying a reaction solution containing a reactant that reacts with an aqueous ink to a transcript. The reaction solution does not have to contain a coloring material because it preferably does not affect the image transferred to the recording medium. Hereinafter, each component and the like used in the reaction solution will be described in detail.

[Reactant]
The reaction solution contains a reactant that reacts with the ink when it comes into contact with the ink and aggregates the components (components having anionic groups such as resin and self-dispersing pigment) in the ink. Examples of the reactant include a cationic component such as a polyvalent metal ion and a cationic resin; and an organic acid. Among them, the reactant is preferably an organic acid, and more preferably a divalent or higher polyvalent carboxylic acid (may be a salt or a hydrogen salt).

Examples of polyvalent metal ions include divalent metal ions ^{such as Ca 2+} , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Sr ²⁺ , Ba ²⁺ , and Zn ^{2+ , Fe 3+} , Cr ³⁺ , Y ³⁺ , and Al. Trivalent metal ions such as ^{3+ can be mentioned.} In order to contain the polyvalent metal ion in the reaction solution, a polyvalent metal salt (which may be a hydrate) formed by bonding the polyvalent metal ion and the anion can be used. Examples of anions include Cl ⁻ , Br ⁻ , I ⁻ , ClO ⁻ , ClO ₂ ⁻ , ClO ₃ ⁻ , ClO ₄ ⁻ , NO ₂ ⁻ , NO ₃ ⁻ , SO ₄ ^2- , CO ₃ ^2- , and HCO ₃ Inorganic anions such as ⁻ , PO ₄ ^3- , HPO ₄ ^2- , and H ₂ PO ₄ ^{− ; HCOO −} , (COO ⁻ ) ₂ , COOH (COO ⁻ ), CH ₃ COO ⁻ , C ₂ H ₄ (COO ⁻⁾ ) ₂ , C ₆ H ₅ COO ⁻ , C ₆ H ₄ (COO ⁻ ) ₂ , and CH ₃ SO ₃ ⁻ and other organic anions can be mentioned. When polyvalent metal ions are used as the reactant, the content (% by mass) in terms of polyvalent metal salt in the reaction solution is 1.0% by mass or more and 20.0% by mass or less based on the total mass of the reaction solution. It is preferable to have.

The reaction solution containing an organic acid has a buffering capacity in an acidic region (pH less than 7.0, preferably pH 2.0 to 5.0), so that the anionic group of the component existing in the ink is efficiently acid-typed. And agglomerate. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, glycolic acid, lactic acid, salicylic acid, pyrrolcarboxylic acid, furancarboxylic acid, picolinic acid, nicotinic acid, thiophenecarboxylic acid, levulinic acid, coumarin acid and the like. Monocarboxylic acids and salts thereof; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, itaconic acid, sebacic acid, phthalic acid, malic acid, tartrate acid, and salts thereof. And hydrogen salts; tricarboxylic acids such as citric acid and trimellitic acid and their salts and hydrogen salts; tetracarboxylic acids such as pyromellitic acid and their salts and hydrogen salts. The content (mass%) of the organic acid in the reaction solution is preferably 1.0% by mass or more and 50.0% by mass or less based on the total mass of the reaction solution.

Examples of the cationic resin include a resin having a structure of a primary amine and a resin having a structure of a quaternary ammonium salt. Specific examples thereof include resins having a structure such as vinylamine, allylamine, vinylimidazole, vinylpyridine, dimethylaminoethyl methacrylate, ethyleneimine, and guanidine. In order to increase the solubility in the reaction solution, the cationic resin and the acidic compound can be used in combination, or the cationic resin can be quaternized. When a cationic resin is used as the reactant, the content (mass%) of the cationic resin in the reaction solution may be 1.0% by mass or more and 10.0% by mass or less based on the total mass of the reaction solution. preferable.

[Other ingredients]
The reaction solution may contain other components other than the reactant, if necessary. Examples of other components include the same components as the resins, aqueous media, and other additives described below that can be contained in the ink.

(ink)
The ink used in the recording method of the present invention is a water-based ink for inkjet. Hereinafter, each component used in the ink and the like will be described in detail.

[Color material]
The ink contains a coloring material. As the coloring material, pigments and dyes can be used. The content (mass%) of the coloring material in the ink is preferably 0.5% by mass or more and 15.0% by mass or less, and 1.0% by mass or more and 10.0% by mass, based on the total mass of the ink. The following is more preferable.

Specific examples of the pigment include inorganic pigments such as carbon black and titanium oxide; and organic pigments such as azo, phthalocyanine, quinacridone, isoindolenone, imidazolone, diketopyrrolopyrrole, and dioxazine.

As a pigment dispersion method, a resin-dispersed pigment using a resin as a dispersant, a self-dispersing pigment in which a hydrophilic group is bonded to the particle surface of the pigment, or the like can be used. Further, a resin-bonded pigment in which an organic group containing a resin is chemically bonded to the surface of the pigment particles, a microcapsule pigment in which the surface of the pigment particles is coated with a resin or the like can be used. Among them, it is preferable to use a resin-dispersed pigment in which a resin as a dispersant is physically adsorbed on the particle surface of the pigment, instead of a resin-bound pigment or a microcapsule pigment.

As the resin dispersant for dispersing the pigment in the aqueous medium, it is preferable to use a resin dispersant capable of dispersing the pigment in the aqueous medium by the action of an anionic group. As the resin dispersant, a resin as described later, particularly a water-soluble resin can be used. The content (mass%) of the pigment in the ink is preferably 0.3 times or more and 10.0 times or less in terms of the mass ratio with respect to the content of the resin dispersant.

As the self-dispersing pigment, an anionic group such as a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group is used which is bonded to the particle surface of the pigment directly or via another atomic group (-R-). be able to. The anionic group may be of either an acid type or a salt type, and when it is a salt type, it may be in a state in which a part thereof is dissociated or a state in which all of the anionic group is dissociated. When the anionic group is a salt type, examples of the cation that becomes a counter ion include alkali metal cations, ammonium, and organic ammonium. Specific examples of other atomic groups (-R-) include a linear or branched alkylene group having 1 to 12 carbon atoms; an arylene group such as a phenylene group or a naphthylene group; a carbonyl group; an imino group; an amide group; a sulfonyl group. Group; ester group; ether group and the like can be mentioned. Further, it may be a group in which these groups are combined.

As the dye, it is preferable to use a dye having an anionic group. Specific examples of the dye include dyes such as azo, triphenylmethane, (aza) phthalocyanine, xanthene, and anthrapyridone. The coloring material contained in the ink is preferably a pigment, and more preferably a resin-dispersed pigment.

[resin]
The ink contains a resin having an anionic group (hereinafter, also simply referred to as “resin”). The content (mass%) of the resin in the ink is preferably 0.1% by mass or more and 20.0% by mass or less, and 0.5% by mass or more and 15.0% by mass or less, based on the total mass of the ink. Is more preferable.

The resin can be added to the ink in order to (i) stabilize the dispersed state of the pigment, that is, as a resin dispersant or an auxiliary thereof. In addition, (ii) can be added to the ink in order to improve various characteristics of the recorded image. Examples of the form of the resin include block copolymers, random copolymers, graft copolymers, and combinations thereof. The resin may be a water-soluble resin that can be dissolved in an aqueous medium, or may be resin particles dispersed in the aqueous medium. The resin particles do not need to contain a coloring material.

In the present specification, "the resin is water-soluble" means that when the resin is neutralized with an acid value and an equivalent amount of alkali, it is aqueous in a state where particles whose particle size can be measured by a dynamic light scattering method are not formed. It means that it exists in the medium. Whether or not the resin is water-soluble can be determined according to the method shown below. First, a liquid (resin solid content: 10% by mass) containing a resin neutralized with an alkali (sodium hydroxide, potassium hydroxide, etc.) equivalent to an acid value is prepared. Next, the prepared liquid is diluted 10-fold (volume basis) with pure water to prepare a sample solution. Then, when the particle size of the resin in the sample solution is measured by the dynamic light scattering method, if the particles having the particle size are not measured, it can be determined that the resin is water-soluble. The measurement conditions at this time can be, for example, as follows.
[Measurement condition]
SetZero: 30 seconds Number of measurements: 3 Measurement time: 180 seconds

As the particle size distribution measuring device, a particle size analyzer (for example, trade name “UPA-EX150”, manufactured by Nikkiso Co., Ltd.) by a dynamic light scattering method can be used. Of course, the particle size distribution measuring device and the measuring conditions to be used are not limited to the above.

The acid value of the water-soluble resin is preferably 100 mgKOH / g or more and 250 mgKOH / g or less. The acid value of the resin constituting the resin particles is preferably 5 mgKOH / g or more and 100 mgKOH / g or less. The weight average molecular weight of the water-soluble resin is preferably 3,000 or more and 15,000 or less. The weight average molecular weight of the resin constituting the resin particles is preferably 1,000 or more and 2,000,000 or less. _{The cumulative 50% particle size (D 50} ) of the resin particles measured by the dynamic light scattering method based on the volume distribution is preferably 50 nm or more and 500 nm or less.

Examples of the resin include acrylic resins, urethane resins, and olefin resins. Of these, acrylic resins and urethane resins are preferable, and acrylic resins composed of units derived from (meth) acrylic acid and (meth) acrylate are even more preferable.

The acrylic resin preferably has a hydrophilic unit and a hydrophobic unit as constituent units. Of these, a resin having a hydrophilic unit derived from (meth) acrylic acid and a hydrophobic unit derived from at least one of a monomer having an aromatic ring and a (meth) acrylic acid ester-based monomer is preferable. In particular, a resin having a hydrophilic unit derived from (meth) acrylic acid and a hydrophobic unit derived from at least one monomer of styrene and α-methylstyrene is preferable. Since these resins are likely to interact with pigments, they can be suitably used as resin dispersants for dispersing pigments.

The hydrophilic unit is a unit having a hydrophilic group such as an anionic group. The hydrophilic unit can be formed, for example, by polymerizing a hydrophilic monomer having a hydrophilic group. Specific examples of the hydrophilic monomer having a hydrophilic group include an acidic monomer having a carboxylic acid group such as (meth) acrylic acid, itaconic acid, maleic acid, and fumaric acid, and anions such as anhydrides and salts of these acidic monomers. Examples include sex monomers. Examples of the cation constituting the salt of the acidic monomer include ions such as lithium, sodium, potassium, ammonium and organic ammonium. A hydrophobic unit is a unit that does not have a hydrophilic group such as an anionic group. The hydrophobic unit can be formed, for example, by polymerizing a hydrophobic monomer having no hydrophilic group such as an anionic group. Specific examples of the hydrophobic monomer include monomers having an aromatic ring such as styrene, α-methylstyrene, and benzyl (meth) acrylate; methyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate 2. -Examples include (meth) acrylic acid ester-based monomers such as ethylhexyl.

The urethane resin can be obtained, for example, by reacting a polyisocyanate with a polyol. Further, the chain extender may be further reacted. Examples of the olefin resin include polyethylene and polypropylene.

The ink preferably contains resin particles. When an ink containing resin particles is used, the resin particles aggregate with the absorption of the liquid component contained in the intermediate image, and the viscosity of the intermediate image can be rapidly increased. Among them, the resin having an anionic group is preferably the first resin particles having an anionic group. When an ink containing the first resin particles having an anionic group is used, the agglomeration of the resin particles is promoted by the reaction between the anionic group and the polyvalent metal salt, and the distortion of the image is further suppressed. The transferability of the intermediate image can be further improved. Furthermore, since the anionic group and the polyvalent metal easily form a chelate structure, a more robust image can be recorded.

The amount of anionic groups (μmol / g) of the first resin particles is preferably 120 μmol / g or more. When the amount of the anionic group is less than 120 μmol / g, the reaction point with the polyvalent metal salt is reduced, so that the effect of promoting the aggregation of the coloring material and the resin particles may be slightly reduced. Therefore, the viscosity of the intermediate image may not increase so much, and the recorded image may be slightly disturbed. On the other hand, the amount of anionic groups (μmol / g) of the first resin particles is preferably 400 μmol / g or less. When the amount of anionic groups exceeds 400 μmol / g, the resin particles aggregate and a large amount of polyvalent metal salt is locally consumed at the interface between the reaction solution and the ink. For this reason, the coloring material is less likely to aggregate as the entire ink, and the recorded image may be slightly disturbed. The amount of anionic groups in the resin particles can be determined from the acid value of the resin particles measured in accordance with JIS K 0070: 1992.

The content (mass%) of the resin particles in the ink is preferably 1.0% by mass or more and 20.0% by mass or less, and 2.0% by mass or more and 15.0% by mass, based on the total mass of the ink. The following is more preferable. When the content of the resin particles is less than 1.0% by mass, the film thickness of the resin particle layer formed between the intermediate image and the porous layer tends to be thin, and the strength of the intermediate image tends to decrease, resulting in defects in the image. May be slightly reduced in the effect of suppressing the occurrence of. On the other hand, if the content of the resin particles is more than 20.0% by mass, the film thickness of the formed resin particle layer becomes too thick, and the absorption of the liquid component from the intermediate image may be slightly lowered.

The ink preferably contains a water-soluble resin. When an ink containing a water-soluble resin is used, the cohesiveness of the resin particles can be enhanced, and the adhesion of the coloring material to the porous layer and the defect of the image can be further suppressed. Among them, the resin having an anionic group is preferably the first water-soluble resin having an anionic group.

The content (mass%) of the water-soluble resin in the ink is preferably 0.05 times or more and 0.50 times or less in terms of the mass ratio (times) with respect to the content (mass%) of the resin particles. If the above ratio is less than 0.05 times, the amount of the water-soluble resin with respect to the resin particles is too small, so that the cohesiveness of the resin particles is insufficient, and adhesion of the coloring material to the porous layer and image loss are suppressed. The effect may be slightly reduced. On the other hand, if the above ratio is more than 0.50 times, the amount of the water-soluble resin with respect to the resin particles is too large, so that a film of the water-soluble resin may be formed, and it is difficult to absorb the liquid component from the intermediate image. May become. Further, when the water-soluble resin comes into contact with the reaction solution and aggregates, the intermediate image may move due to the volume shrinkage accompanying the aggregation of the water-soluble resin, and the image after transfer may be easily distorted.

[Aqueous medium]
The ink used in the recording method of the present invention is a water-based ink containing at least water as an aqueous medium. The ink may contain water or an aqueous medium which is a mixed solvent of water and a water-soluble organic solvent. As the water, it is preferable to use deionized water or ion-exchanged water. The water content (mass%) in the water-based ink is preferably 50.0% by mass or more and 95.0% by mass or less based on the total mass of the ink. The content (mass%) of the water-soluble organic solvent in the water-based ink is preferably 3.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. As the water-soluble organic solvent, any solvent that can be used for ink jet ink such as alcohols, (poly) alkylene glycols, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds can be used.

[Other additives]
In addition to the above components, various inks such as defoamers, surfactants, pH adjusters, viscosity regulators, rust inhibitors, preservatives, fungicides, antioxidants, antioxidants, etc. Additives may be included. However, it is preferable that the ink does not contain the reactant used in the reaction solution as described above. When the reactant is contained in the ink, the content of the reactant in the ink is preferably very small (for example, about 0.05% by mass or less).

(Transfer accelerator)
The transcription promoting liquid used in the recording method of the present invention is an aqueous liquid containing an amphoteric surfactant. Hereinafter, each component and the like used in the transcription promoting solution will be described in detail.

[Amphoteric surfactant]
By using a transfer accelerator containing an amphoteric surfactant, it is possible to promote the aggregation of the ink layer on the surface side, which is insufficiently aggregated. Further, the hydrophobic portion of the amphoteric surfactant is oriented toward the surface side of the ink layer, so that the surface energy of the formed intermediate image is reduced. As a result, the surface of the intermediate image is less likely to interact with the porous layer, so that the adhesion of the coloring material to the porous layer can be effectively suppressed. From the viewpoint of ease of orientation and the like, the number of carbon atoms in the hydrophobic portion of the amphoteric surfactant is preferably 8 or more.

It is considered that the viscosity of the formed intermediate image can be increased by the interaction between the unreacted anionic group of the resin contained in the ink and the cationic group of the amphoteric surfactant. The amphoteric surfactant preferably has a carboxylic acid group. The carboxylic acid group of the amphoteric surfactant interacts with the anionic group that has reacted with the reactant. Furthermore, it is considered that the viscosity of the intermediate image can be increased by ionic bonding the cationic group of the amphoteric surfactant with the unreacted anionic group.

If the intermediate image is aggregated using a cationic polymer or acid in order to suppress the adhesion of the coloring material to the porous layer, the intermediate image becomes too hard, and the intermediate image follows the irregularities on the surface of the recording medium during transfer. It becomes difficult and the image is liable to be damaged. On the other hand, when an amphoteric surfactant is used, the cohesive force is not so strong, so that it is considered that good transferability can be maintained. In addition, when an excess amount of the reactant is present, the amphoteric surfactant accepts the excess acid or chelates the polyvalent metal to prevent the intermediate image from becoming excessively hard. Is thought to be possible.

It is considered that the ink layer contains a region having a high pH and a region having a low pH. Anionic surfactants tend to be insoluble in low pH regions, and cationic surfactants tend to be insoluble in high pH regions. On the other hand, amphoteric surfactants are difficult to insolubilize even if there is a local bias in pH, so the effect of increasing the viscosity of the intermediate image and the effect of suppressing the adhesion of the coloring material to the porous layer are stable. It is thought that it can be expressed.

The content (mass%) of the amphoteric tenside in the transfer accelerator is preferably 0.1% by mass or more and 10.0% by mass or less, based on the total mass of the transfer accelerator, and is 3.0% by mass. It is more preferably 8.0% by mass or less. If the content of the amphoteric surfactant is less than 0.1% by mass, the reactivity of the resin with the unreacted anionic group may be slightly lowered. For this reason, it becomes difficult to sufficiently increase the viscosity of the intermediate image, and the effect of increasing the viscosity of the intermediate image and the effect of suppressing the adhesion of the coloring material to the porous layer may be slightly reduced. On the other hand, when the content of the amphoteric surfactant is more than 10.0% by mass, the amphoteric surfactant tends to be excessively present. For this reason, the viscosity of the intermediate image may be rather lowered by the amphoteric surfactant that is not involved in the reaction, and the effect of increasing the viscosity of the intermediate image and the effect of suppressing the adhesion of the coloring material to the porous layer may be slightly reduced. is there.

Examples of the amphoteric surfactant include an alkyl betaine type surfactant, a fatty acid amide propyl betaine type surfactant, and an alkyl imidazole type surfactant. Specific commercial products include Softazoline CL-R, Softazoline LPB (all manufactured by Kawaken Fine Chemical Co., Ltd.); Anchtor 20HD (manufactured by Kao Corporation), and the like under the following trade names.

[Resin particles]
The transfer accelerator preferably contains resin particles. When a transfer accelerator containing resin particles is used, a resin layer can be formed on the intermediate image, so that the transferability of the intermediate image to a recording medium having large surface irregularities can be further improved. As the resin particles, it is preferable to use a second resin particle having an anionic group. The amount of anionic groups (μmol / g) of the second resin particles is preferably 120 μmol / g or more. As the second resin particles, the same particles as the above-mentioned first resin particles used for the ink can be used.

The content (mass%) of the resin particles in the transfer accelerator is preferably 1.0% by mass or more and 20.0% by mass or less, and 2.0% by mass or more and 15 by mass or more, based on the total mass of the transfer accelerator. It is more preferably 0.0% by mass or less. When the content of the resin particles is less than 1.0% by mass, the film thickness of the resin layer formed on the intermediate image is too thin, so that the effect of improving the followability of the surface unevenness of the recording medium is slightly reduced. In some cases. On the other hand, when the content of the resin particles is more than 20.0% by mass, the film thickness of the resin layer formed on the intermediate image is too thick, so that the ability of the recording medium to follow the surface irregularities is improved, but recording is performed. The resulting image may be easily distorted. _{The cumulative 50% particle size (D 50} ) based on the volume distribution of the resin particles in the transfer promoting liquid measured by the dynamic light scattering method is preferably 50 nm or more and 500 nm or less.

[Water-soluble resin]
The transfer accelerator preferably contains a water-soluble resin. When a transfer accelerator containing a water-soluble resin is applied to an intermediate image on the transfer body, the water-soluble resin enters between adjacent resin particles in the intermediate image, so that the viscosity of the formed resin layer increases. The transferability can be further improved. As the water-soluble resin, it is preferable to use a second water-soluble resin having an anionic group. As the second water-soluble resin, the same one as the above-mentioned first water-soluble resin used for ink can be used.

The content (mass%) of the second water-soluble resin in the transfer accelerator is a mass ratio (times) with respect to the content (mass%) of the first resin particles, which is 0.05 times or more and 0.50 times or less. Is preferable. If the above ratio is less than 0.05 times, the amount of the water-soluble resin with respect to the resin particles is too small, so that the strength of the resin layer formed by the first resin particles is difficult to increase, and the image after transfer is distorted. May be more likely to occur. On the other hand, if the above ratio is more than 0.50 times, the amount of the second water-soluble resin relative to the first resin particles is too large, so that the water-soluble resin that moves freely without getting between the resin particles. The ratio may increase, and the image after transfer may be easily distorted.

[Other ingredients]
In addition to the above components, the transfer accelerator can further contain components similar to those of an aqueous medium and various additives that can be contained in the ink, if necessary.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded. Unless otherwise specified, the amounts of components described as "parts" and "%" are based on mass.

<Preparation of pigment dispersion liquid>
(Pigment dispersion liquid 1)
A styrene-acrylic acid copolymer (resin dispersant) having an acid value of 120 mgKOH / g and a weight average molecular weight of 8,000 was prepared. An aqueous solution of the resin dispersant was prepared by neutralizing 8.0 parts of the resin dispersant with water containing sodium hydroxide having an acid value equal to the molar amount, and then dissolving the resin dispersant in ion-exchanged water. The prepared aqueous solution of the resin dispersant, ^{20.0 parts of carbon black having a specific surface area of 220 m 2} / g and a DBP oil absorption of 105 mL / 100 g, and 72.0 parts of ion-exchanged water were mixed to obtain a mixture. The obtained mixture and 200 parts of zirconia beads having a particle size of 0.3 mm were placed in a batch type vertical sand mill (manufactured by Imex) and dispersed for 3 hours. After centrifuging to remove coarse particles, pressure filtration is performed with a microfilter (manufactured by Fujifilm) with a pore size of 3.0 μm, and the carbon black (pigment) content is 10.0% and the resin dispersant is contained. A pigment dispersion 1 having an amount of 2.0% was obtained.

(Pigment dispersion liquid 2)
A solution prepared by dissolving 2.5 g of concentrated hydrochloric acid in 5.5 g of water was cooled to 5 ° C., and 0.8 g of p-aminobenzoic acid was added in this state. A container containing this solution was placed in an ice bath, and the solution obtained by dissolving 0.9 g of sodium nitrite in 9.0 g of water was added while keeping the temperature of the solution at 10 ° C. or lower with stirring. After stirring for 15 minutes, 9.0 g of carbon black having a specific surface area of 220 m ² / g and a DBP oil absorption of 105 mL / 100 g was added and mixed. The mixture was further stirred for 15 minutes to obtain a slurry. The obtained slurry was filtered through a filter paper (trade name "Standard Filter Paper No. 2", manufactured by Advantech), the particles were thoroughly washed with water, and dried in an oven at 110 ° C. An appropriate amount of water was added to adjust the content of carbon black to obtain a pigment dispersion liquid 2 having a content of self-dispersing pigment (carbon black) of 10.0%.

<Preparation of aqueous dye solution>
After dissolving the dye (CI Direct Blue 199) in ion-exchanged water, an acid was added to precipitate the dye. The precipitated dye was filtered and separated to obtain a wet cake of a free acid type dye. The obtained wet cake was added to ion-exchanged water, and water containing an anionic group of the dye and an equimolar amount of sodium hydroxide was added to neutralize all the anionic groups and dissolve the dye. Further, an appropriate amount of ion-exchanged water was added to obtain a dye aqueous solution having a dye content of 10.0%.

<Preparation of liquid containing resin particles>
(Liquid containing resin particles 1)
18.0 parts of butyl methacrylate, 0.35 parts of methacrylic acid, 2.0 parts of polymerization initiator, and 2.0 parts of n-hexadecane in a flask equipped with a stirrer, a nitrogen introduction tube, a reflux cooling device, and a thermometer. Was added, and the mixture was stirred for 30 minutes while introducing nitrogen gas. As the polymerization initiator, 2,2'-azobis (2-methylbutylnitrile) was used. Then, 78.0 parts of a 6.0% aqueous solution of polyoxyethylene cetyl ether (trade name “NIKKOL BC-20”, manufactured by Nikko Chemicals Co., Ltd.) was added dropwise, and the mixture was stirred for 30 minutes to obtain a mixture. After irradiating the mixture with ultrasonic waves for 3 hours using an ultrasonic irradiator to emulsify the mixture, a polymerization reaction was carried out at 80 ° C. for 4 hours in a nitrogen atmosphere. After cooling to 25 ° C. and filtering, an appropriate amount of pure water was added to obtain a liquid containing resin particles 1 having a resin particle content of 50.0%. The amount of anionic groups in the resin particles 1 was 180 μmol / g.

(Liquid containing resin particles 2)
A liquid containing resin particles 2 having a resin particle content of 50.0% was prepared in the same manner as in the case of the liquid containing resin particles 1 described above, except that the amount of methacrylic acid was changed to 0.22 parts. Obtained. The amount of anionic groups in the resin particles 2 was 100 μmol / g.

(Liquid containing resin particles 3)
A liquid containing resin particles 3 having a resin particle content of 50.0% was prepared in the same manner as in the case of the liquid containing resin particles 1 described above, except that the amount of methacrylic acid was changed to 0.27 parts. Obtained. The amount of anionic groups in the resin particles 3 was 120 μmol / g.

(Liquid containing resin particles 4)
A liquid containing resin particles 4 having a resin particle content of 50.0% was prepared in the same manner as in the case of the liquid containing resin particles 1 described above, except that the amount of methacrylic acid was changed to 0.79 parts. Obtained. The amount of anionic groups in the resin particles 4 was 400 μmol / g.

(Liquid containing resin particles 5)
An aqueous potassium persulfate solution was prepared by dissolving 0.2 parts of potassium persulfate in 81.8 parts of ion-exchanged water. An emulsion was prepared by mixing 16.1 parts of ethyl methacrylate, 1.6 parts of methoxypolyethylene glycol methacrylate (trade name "Blemmer PME1000", manufactured by NOF CORPORATION), and 0.3 part of a surfactant. As the surfactant, the trade name "NIKKOL BC-20" (manufactured by Nikko Chemicals Co., Ltd.) was used. The emulsion was added dropwise to the potassium persulfate aqueous solution under a nitrogen atmosphere over 1 hour, and the polymerization reaction was carried out while stirring at 80 ° C., and the mixture was further stirred for 2 hours. After cooling to 25 ° C., ion-exchanged water and an aqueous potassium hydroxide solution were added to obtain a liquid containing nonionic resin particles 5. The content of the resin particles was 50.0% and the pH was 8.5. The 50% cumulative volume average particle diameter (D50) of the resin particles 5 in the liquid containing the resin particles 5 was 70 nm. The resin particles 5 are resin particles that do not aggregate even when they come into contact with a reaction solution described later.

(Liquid containing resin particles 6)
In a four-necked flask equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a cooling tube, 240.0 parts of polypropylene glycol, 282.0 parts of isophorone diisocyanate, and 0.007 parts of dibutyltin dilaurate were placed to create a nitrogen gas atmosphere. The reaction was carried out at 100 ° C. for 5 hours. After cooling to 65 ° C. or lower, 19 parts of dimethylolpropionic acid, 447.8 parts of neopentyl glycol, and 150.0 parts of methyl ethyl ketone were added and reacted at 80 ° C. After cooling to 40 ° C., 20.0 parts of methanol was added to stop the reaction. After adding an appropriate amount of ion-exchanged water, the amount of 10.0% potassium hydroxide aqueous solution required to neutralize the anionic groups of the resin was added while stirring with a homomixer. Methyl ethyl ketone and unreacted methanol were distilled off under heating and reduced pressure to obtain a liquid containing resin particles 6 having a resin particle content of 50.0%. The resin particles 6 were urethane resin particles, and the amount of anionic groups was 180 μmol / g.

(Measurement of the amount of anionic groups (μmol / g) of resin particles)
Hydrochloric acid is added dropwise to the liquid containing the resin particles to bring the pH to 2 or less, the precipitate is filtered, washed with water, and dried under reduced pressure at 40 ° C. to obtain a dried product. Using the obtained dried product as a measurement sample, the acid value (mgKOH / g) of the resin is measured according to JIS K 0070: 1992. Since the molecular weight of potassium hydroxide is 56.1 (mg / mmol), the amount of anionic groups (μmol / g) of the resin particles can be calculated from the following formula (1).
Amount of anionic groups in resin particles (μmol / g)
= Acid value (mgKOH / g) x 1,000 / 56.1 ... (1)

<Preparation of liquid containing anionic water-soluble resin>
Anionic styrene-ethyl acrylate-acrylic acid copolymer produced by a conventional method is neutralized with water containing potassium hydroxide having an acid value and an equal molar amount, and the resin content is 40.0%. A liquid containing a water-soluble resin was obtained. The acid value of the styrene-ethyl acrylate-acrylic acid copolymer was 150 mgKOH / g, and the weight average molecular weight was 8,000.

<Ink preparation>
Each component (unit:%) shown in Table 1 was mixed, sufficiently stirred, and then pressure-filtered with a microfilter (manufactured by FUJIFILM) having a pore size of 3.0 μm to prepare each ink. In Table 1, "PVA-103" is a trade name of a nonionic water-soluble resin (polyvinyl alcohol) manufactured by Kuraray. "Acetyleneol E100" is a trade name of a nonionic surfactant (ethylene oxide adduct of acetylene glycol) manufactured by Kawaken Fine Chemicals.

(Transfer accelerator)
Each component (unit:%) shown in Tables 2-1 and 2-2 is mixed, sufficiently stirred, and then pressure-filtered with a microfilter (manufactured by FUJIFILM) having a pore size of 3.0 μm to prepare each treatment liquid. Prepared. In Tables 2-1 and 2-2, "PVA-103" is a trade name of a nonionic water-soluble resin (polyvinyl alcohol) manufactured by Kuraray, and "PAA-08" is a trade name of a cationic polymer manufactured by Nitto Boseki. Is. "Acetyleneol E100" is a trade name of a nonionic surfactant (ethylene oxide adduct of acetylene glycol) manufactured by Kawaken Fine Chemicals. The details of the surfactants in Tables 2-1 and 2-1 are shown below.
-Amphoteric surfactant A: Product name "Softazoline CL-R" (manufactured by Kawaken Fine Chemicals)
-Amphoteric surfactant B: Product name "Softazoline LPB" (manufactured by Kawaken Fine Chemicals)
-Amphoteric surfactant C: Product name "Softazoline LAO-C" (manufactured by Kawaken Fine Chemicals)
-Amphoteric surfactant D: Product name "Anchor 20HD" (manufactured by Kao)
-Anionic surfactant: Product name "F-410" (manufactured by DIC)

<Preparation of reaction solution>
Each component (unit:%) shown in Table 3 was mixed, sufficiently stirred, and then pressure-filtered with a microfilter (manufactured by FUJIFILM) having a pore size of 3.0 μm to prepare a reaction solution. In Table 3, "Acetyleneol E100" is a trade name of a nonionic surfactant (ethylene oxide adduct of acetylene glycol) manufactured by Kawaken Fine Chemicals, and "Orphine E1010" is a nonionic surfactant manufactured by Nisshin Kagaku Kogyo. It is a product name of. For "reaction solution 4", a 10% aqueous solution of lithium hydroxide was added to adjust the pH to 3.6.

<Evaluation>
(Recording of images)
The ink, reaction solution, and transfer accelerator were combined as shown on the left side of Table 4. Then, an image was recorded using the transfer type inkjet recording apparatus 100 having the configuration shown in FIG. The configuration of the transfer type inkjet recording device 100 is shown below. As the support member 102, a cylindrical drum made of an aluminum alloy was used. As the surface member of the transfer body 101, a polyethylene terephthalate film having a thickness of 0.5 mm and a silicone rubber (trade name "KE12", manufactured by Shin-Etsu Chemical Co., Ltd.) having a rubber hardness (durometer type A) of 40 ° are applied to the film by 0.2 mm. The one coated to the thickness of was used. Using a normal pressure plasma processing device (trade name "ST-7000", manufactured by KEYENCE) on this surface layer member, plasma surface treatment is performed under the conditions of processing distance: 5 mm, plasma mode: High, and processing speed: 100 mm / sec. gave. Further, the surface of the surface layer member is immersed in a surfactant aqueous solution prepared by diluting with pure water so that the concentration of a commercially available neutral detergent (sodium alkylbenzene sulfonate) becomes 3% for 10 seconds, and then dried. It was used as a surface member of the transfer body 101. The transfer body 101 was fixed to the support member 102 using double-sided adhesive tape.

The reaction solution was applied onto the transcript 101 at a concentration of 1.0 g / m ² using the reaction solution application device 103. A recording head of a type that ejects ink and transfer accelerator by an on-demand method equipped with an electric-heat conversion element is used as an ink and transfer accelerator applying device 104, and the ink-applied region of the transfer body 101 is used. A transcription promoting liquid can be applied.

<Preparation of porous layer>
The emulsion-polymerized particles of the crystallized fluorine-based resin (polytetrafluoroethylene) were compression-molded and then stretched at a temperature equal to or lower than the melting point to prepare a fibrillated porous layer (first layer). Further, polyethylene and polypropylene were mixed and then stretched by a wet method to prepare a fibrillated porous layer (second layer). In addition, a polyolefin-based non-woven fabric (trade name "HOP60", manufactured by Hirose Paper Co., Ltd.) was prepared as the third layer. The second layer is thicker than the first layer. Further, the average pore diameter of the second layer is smaller than the average pore diameter of the first layer. The first layer, the second layer, and the third layer were hot-pressure laminated and adhered to obtain a porous layer.

The porous layer prepared above was used as the liquid absorbing member 105a. The transport speed of the liquid absorbing member 105a was adjusted to a speed (0.4 m / sec) equivalent to the moving speed of the transfer body 101 by the transport roller 105c that transports the liquid absorbing member 105a while stretching it. The liquid absorbing member 105a was immersed in a treatment liquid containing 95.0 parts of ethanol and 5.0 parts of water, permeated the treatment liquid into the voids of the porous layer, and then replaced with water for use. A pressure was applied to the pressing member 105b so that the nip pressure between the transfer body 101 and the liquid absorbing member 105a was 4 kg / cm ^2. In addition, liquid absorption was not carried out only in Comparative Example 4.

The recording medium 108 was conveyed by driving 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 recording medium 108 and the intermediate image were brought into contact with each other between the transfer body 101 and the pressing member 106, and the intermediate image was transferred from the transfer body 101 to the recording medium 108 to record a solid image. As the recording medium 108, coated paper (trade name “Van Nouveau V”, manufactured by Daio Paper Products, basis weight 157 g / m ² , arithmetic surface roughness Ra 4 μm) was used. The nip pressure between the transfer body 101 and the pressing member 106 was adjusted to ^{3 kg / cm 2.}

(Adhesion of color material to the porous layer (transfer of color material))
Using the transfer type inkjet recording apparatus 100 having the above configuration, an intermediate image of 5 cm × 5 cm having an ink recording duty of 20% and a processing liquid recording duty of 100% was formed on the transfer body 101. .. Then, the intermediate image was transferred to the above recording medium to record an image (5 cm × 5 cm solid image). In this transfer type inkjet recording apparatus 100, recording was performed under the condition that one drop of 3.0 ng was applied to a unit area of 1/1, 200 inch × 1/1, 200 inch at a resolution of 1,200 dpi × 1,200 dpi. An image is defined as having a recording duty of 100%.

After recording images on a predetermined number of recording media, the porous layer of the liquid absorbing member 105a was observed, and the adhesion of the coloring material (transfer of the coloring material) to the porous layer was evaluated according to the evaluation criteria shown below. In the present invention, "AA", "A", and "B" are set to an acceptable level, and "C" is set to an unacceptable level. The results are shown in Table 4.
AA: Even when the image was recorded on 500 recording media, the coloring material did not adhere to the porous layer.
A: When the image was recorded on 500 recording media, the coloring material was attached to the porous layer.
B: When the image was recorded on 300 recording media, the coloring material was attached to the porous layer.
C: When the image was recorded on 100 recording media, the coloring material was attached to the porous layer.

(Transcribability)
The recorded image was visually observed, and the transferability was evaluated according to the evaluation criteria shown below. In the present invention, "AA", "A", and "B" are set to an acceptable level, and "C" is set to an unacceptable level. The results are shown in Table 4.
AA: No defects were found in the image.
A: Defects were found in the image, but it was not noticeable.
B: Defects were found in the image, but it was acceptable.
C: A remarkable defect was observed in the image.

Claims (12)

An inkjet recording method for recording an image on a recording medium using water-based ink.
A reaction solution applying step of applying an aqueous reaction solution containing a reactant that reacts with the water-based ink to the transcript, and a reaction solution applying step.
An ink application step of applying the water-based ink containing a resin having an anionic group and a coloring material to the region of the transfer material to which the reaction solution has been applied.
A transfer-promoting liquid application step of applying an aqueous transfer-promoting liquid containing an amphoteric tenside to the region of the transfer body to which the water-based ink has been applied to form an intermediate image.
A liquid absorption step of bringing the porous layer of the liquid absorbing member including the porous layer into contact with the intermediate image and absorbing at least a part of the liquid component from the intermediate image.
An inkjet recording method comprising a transfer step of bringing the intermediate image in which at least a part of the liquid component is absorbed into contact with the recording medium and transferring the image. The inkjet recording method according to claim 1, wherein the resin having an anionic group is a first resin particle having an anionic group. The inkjet recording method according to claim 2, wherein the amount of anionic groups (μmol / g) of the first resin particles is 120 μmol / g or more. The inkjet recording method according to claim 1, wherein the resin having an anionic group is a first water-soluble resin having an anionic group. The inkjet recording method according to any one of claims 1 to 4, wherein the transfer-promoting liquid further contains a second resin particle having an anionic group. The inkjet recording method according to claim 5, wherein the amount of anionic groups (μmol / g) of the second resin particles is 120 μmol / g or more. The inkjet recording method according to any one of claims 1 to 6, wherein the transfer accelerator further contains a second water-soluble resin having an anionic group. The inkjet recording method according to any one of claims 1 to 7, wherein the amphoteric surfactant has a carboxylic acid group. Any of claims 1 to 8 in which the content (mass%) of the amphoteric tenside agent in the transfer accelerator is 0.1% by mass or more and 10.0% by mass or less based on the total mass of the transfer accelerator. The inkjet recording method according to item 1. Any of claims 1 to 8 in which the content (mass%) of the amphoteric tenside agent in the transfer accelerator is 3.0% by mass or more and 8.0% by mass or less based on the total mass of the transfer accelerator. The inkjet recording method according to item 1. The inkjet recording method according to any one of claims 1 to 10, wherein the reactant is an organic acid. An inkjet recording device used to record an image on a recording medium using water-based ink.
A reaction solution-imparting means for imparting an aqueous reaction solution containing a reactant that reacts with the water-based ink to the transcript, and a reaction solution-imparting means.
An ink applying means for applying the water-based ink containing a resin having an anionic group and a coloring material to the region of the transfer body to which the reaction solution has been applied.
A transfer-promoting solution-imparting means for forming an intermediate image by applying an aqueous transfer-promoting solution containing an amphoteric surfactant to the region of the transfer body to which the water-based ink has been applied.
A liquid absorbing means for bringing the porous layer of the liquid absorbing member including the porous layer into contact with the intermediate image and absorbing at least a part of the liquid component from the intermediate image.
An inkjet recording apparatus comprising: a transfer means for bringing the intermediate image in which at least a part of the liquid component has been absorbed into contact with the recording medium and transferring the image.

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