Inkjet recording method, inkjet recording device, and set of reaction liquid and maintenance liquid

Abstract

To provide an inkjet recording method which sufficiently removes a thickened matter and a precipitate attached to a discharge port surface of a liquid application device for discharging a reaction liquid, and can be recovered to such a discharge state as to prevent occurrence of non-discharge and discharge deflection, even when being recorded for a long period of time.SOLUTION: An inkjet recording method records an image on a recording medium using an inkjet recording device. The inkjet recording device includes a first liquid application device having a discharge port for discharging aqueous ink, and a second liquid application device having a discharge port for discharging an aqueous reaction liquid containing a reaction agent reactive with the aqueous ink. The inkjet recording device also includes a maintenance liquid application device for applying an aqueous maintenance liquid onto a discharge port surface formed with the discharge port of the second liquid imparting device, and a first cleaning device which is pressed against the discharge port surface of the second liquid application device and cleans the discharge port surface. An absolute value of a difference between surface tension γR of the reaction liquid and surface tension γC of the maintenance liquid is 15 mN / m or less, and a content (mass%) of water in the reaction liquid is 5 times or more of a content (mass%) of the reaction agent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an inkjet recording method, an inkjet recording apparatus, and a set of a reaction liquid and a maintenance liquid. [Background technology]

[0002] It is known that an inkjet recording apparatus records an image on a recording medium by ejecting minute ink droplets from the ejection openings of a recording head, which is a liquid application device. In recent years, the use of inkjet recording apparatuses in the field of high-speed label recording has been considered. In the field of high-speed label recording, there is a demand for an inkjet recording apparatus that is capable of recording on recording media that have low absorbency for water-based ink or that barely absorb water-based ink, in addition to recording media that have high absorbency for water-based ink, and that is capable of mass-producing recorded matter in a short period of time.

[0003] Examples of recording media that have high absorbency for water-based inks (hereinafter also referred to as "absorbent recording media") include recording media that do not have a coating layer, such as plain paper and fine paper. Examples of recording media that have low absorbency for water-based inks (hereinafter also referred to as "low absorbent recording media") include recording media that have a coating layer, such as art paper and coated paper. Examples of recording media that barely absorb water-based inks (hereinafter also referred to as "non-absorbent recording media") include plastic films.

[0004] As for the ink, the use of aqueous inks containing pigments has been considered from the viewpoints of the environment and safety. For absorbent recording media, the applied ink droplets easily penetrate the recording medium, making it difficult to obtain image quality with the high level of optical density required in recent years. In addition, for low-absorbent recording media and non-absorbent recording media, the applied ink droplets do not easily penetrate the recording medium, so adjacent ink droplets are applied before the image is fixed by penetration. As a result, the ink droplets merge with each other, causing bleeding and unevenness, making it difficult to obtain practical image quality.

[0005] Therefore, a reaction liquid containing a reactant that reacts with the ink, specifically, a reaction liquid containing a reactant that reacts with the pigment or solid content in the ink to cause aggregation and thickening, is used. When the reaction liquid is discharged from the discharge port of the liquid application device, a mist is generated, and a part of this mist adheres to the discharge port surface of the liquid application device. When the reaction liquid is discharged for a long time, the amount of mist that adheres to the discharge port surface of the liquid application device increases, and water and solvent evaporate from the mist, causing a thickened substance and a precipitate of the reactant. If the thickened substance or precipitate exists near the discharge port of the reaction liquid, non-discharge or irregular discharge of the reaction liquid occurs. When non-discharge or irregular discharge of the reaction liquid occurs, sufficient reaction liquid cannot be discharged to a specified position, and image quality decreases. Therefore, when non-discharge or irregular discharge of the reaction liquid from the liquid application device occurs, it is necessary to restore the discharge state of the reaction liquid to a normal state. Patent documents 1 and 2 propose a technology for a recovery method of a liquid application device using a reaction liquid. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-105134 A [Patent Document 2] JP 2013-064074 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present inventors have investigated the recovery of the ejection state of the reaction liquid using the inkjet recording device, aqueous reaction liquid, aqueous ink, maintenance liquid, and cleaning device proposed in Patent Documents 1 and 2. As a result, they found that it is difficult to fully recover the ejection state of the reaction liquid from the ejection port to a normal state after ejecting the reaction liquid for a long period of time.

[0008] Therefore, an object of the present invention is to provide an inkjet recording method capable of sufficiently removing thickened substances and precipitates adhering to the discharge port surface of a liquid application device that discharges a reaction liquid, and recovering the discharge state to one in which discharge failures and discharge irregularities are unlikely to occur, even when recording for a long period of time. Another object of the present invention is to provide an inkjet recording device, and a set of a reaction liquid and a maintenance liquid to be used in the inkjet recording method. [Means for solving the problem]

[0009] That is, according to the present invention, there is provided an inkjet recording method for recording an image on a recording medium using an inkjet recording device, the inkjet recording device comprising: a first liquid application device having an ejection port for ejecting an aqueous ink; a second liquid application device having an ejection port for ejecting an aqueous reactive liquid containing a reactant that reacts with the aqueous ink; a maintenance liquid application device for applying an aqueous maintenance liquid to an ejection port surface on which the ejection ports of the second liquid application device are formed; and a first cleaning device that is pressed against the ejection port surface of the second liquid application device to clean the ejection port surface, and R (mN / m) and the surface tension γ C and the absolute value of the difference between the resistivity and the resistivity (mN / m) is 15 mN / m or less, and the content of water (mass %) in the reaction liquid is 5 times or more the content of the reactant (mass %). Effect of the Invention

[0010] According to the present invention, it is possible to provide an inkjet recording method capable of sufficiently removing thickened substances and precipitates adhering to the discharge port surface of a liquid application device that discharges a reaction liquid, and recovering the discharge state to one in which discharge failures and discharge irregularities are unlikely to occur, even when recording is performed for a long period of time. Also, according to the present invention, it is possible to provide an inkjet recording device used in this inkjet recording method, and a set of a reaction liquid and a maintenance liquid. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram illustrating an embodiment of an inkjet recording apparatus of the present invention. [Diagram 2] FIG. 2 is a perspective view showing an example of a liquid application device. [Diagram 3] FIG. 2 is a cross-sectional perspective view showing an example of a discharge element substrate. [Figure 4] FIG. 2 is a schematic diagram showing an example of a liquid supply system. [Diagram 5] FIG. 2 is a perspective view showing an example of a capping tray. [Figure 6] FIG. 2 is a perspective view showing an example of a cleaning tray. [Figure 7] FIG. 4 is a schematic diagram showing an example of a supply system of the maintenance device. [Figure 8] FIG. 2 is a perspective view illustrating an example of a cleaning unit. [Figure 9A] FIG. 2 is a perspective view illustrating an example of a maintenance liquid deposition device. [Figure 9B] 9B is a cross-sectional view taken along the line AA in FIG. 9A, showing an example of a maintenance liquid deposition device. [Figure 9C] FIG. 9B is a cross-sectional view of an example of a maintenance liquid deposition device according to the embodiment of the present invention; [Figure 10] FIG. 4 is a schematic diagram showing an example of the positional relationship between a liquid application device and a cleaning unit. [Figure 11] FIG. 11 is a schematic diagram showing an example of a cleaning operation. [Figure 12] FIG. 13 is a schematic diagram showing another example of the heating unit. [Figure 13] FIG. 11 is a schematic diagram showing another example of the fixing unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in more detail below with reference to preferred embodiments. In the present invention, when the compound is a salt, the salt is present in the ink in the form of dissociation into ions, but for convenience, it is expressed as "containing a salt." In addition, the aqueous ink and reaction liquid for inkjet printing may be simply referred to as "ink" and "reaction liquid." Physical property values ​​are values ​​at room temperature (25°C) unless otherwise specified. When "(meth)acrylic acid" and "(meth)acrylate" are written, they mean "acrylic acid, methacrylic acid" and "acrylate, methacrylate," respectively.

[0013] In an inkjet recording method using an aqueous ink and an aqueous reaction liquid containing a reactant that reacts with the aqueous ink, an inkjet recording apparatus is used that includes a liquid application device having an outlet for ejecting the ink, and a liquid application device having an outlet for ejecting the reaction liquid. In this specification, the liquid application device that ejects the ink may be referred to as a "first liquid application device," and the liquid application device that ejects the reaction liquid may be referred to as a "second liquid application device," and they may be collectively referred to as a "liquid application device."

[0014] When an aqueous reaction liquid containing a reactant that reacts with the aqueous ink discharged from the first liquid application device is discharged from the discharge port of the second liquid application device, mist is generated, and part of this mist adheres to the discharge port surface of the second liquid application device. When the reaction liquid is discharged for a long period of time, the amount of mist adhering to the discharge port surface of the second liquid application device increases, and water and solvent evaporate from the mist, causing thickened matter and precipitates of the reactant. If thickened matter or precipitates are present near the discharge port of the second liquid application device, non-discharge or irregular discharge of the reaction liquid occurs. If non-discharge or irregular discharge of the reaction liquid occurs, it becomes impossible to discharge a sufficient amount of reaction liquid at a specified position, and image quality decreases.

[0015] The deterioration of image quality when using the above-mentioned ink and reaction liquid is a phenomenon that is particularly likely to occur when a low-absorbency or non-absorbency recording medium is used as the recording medium. 1 / 2Water absorption up to 4mL / m 2 More than 10mL / m 2 A non-absorbent recording medium is one that is absorbent within 30 msec from the start of contact in the Bristow method. 1 / 2 Water absorption up to 0mL / m 2 More than 4mL / m 2 That is, low absorbency and non-absorbency recording media refer to recording media that are less than 30 msec from the start of contact in the Bristow method. 1 / 2 Water absorption up to 0mL / m 2 More than 10mL / m 2 The penetration speed of ink or reaction liquid is relatively fast (30 msec from the start of contact in the Bristow method). 1 / 2 Water absorption up to 10mL / m 2 In the case of plain paper, which is an absorbent recording medium having a high absorbency (super absorbent), the reaction liquid penetrates the recording medium immediately after it is applied to the recording medium. After that, when the ink applied to the recording medium comes into contact with the reaction liquid, the pigment and the aqueous medium also penetrate into the recording medium while coagulating. Therefore, there is no flow of ink on the surface of the recording medium, so there is almost no movement of the pigment, and image quality is unlikely to deteriorate. On the other hand, in the case of low-absorbency and non-absorbency recording media that hardly absorb ink or reaction liquid, the reaction liquid hardly penetrates, so the reaction liquid and ink are present on the surface of the low-absorbency and non-absorbency recording media. Therefore, the ink is likely to flow on the surface of the recording medium, and image quality is likely to deteriorate.

[0016] In order to prevent deterioration of image quality due to non-ejection or irregular ejection of the reaction liquid, it is necessary to remove the thickened matter and precipitates adhering to the ejection port surface of the second liquid application device and restore the ejection state of the reaction liquid to a normal state. However, as described above, in the techniques proposed in Patent Documents 1 and 2, even if the recovery operation of the second liquid application device is performed after ejection of the reaction liquid for a long period of time, it is difficult to sufficiently restore the ejection state of the reaction liquid to a normal state. Therefore, the present inventors have studied a method for sufficiently removing the thickened matter and precipitates adhering to the ejection port surface of the liquid application device of the reaction liquid and restoring the ejection state to one in which non-ejection or irregular ejection is unlikely to occur, even when the reaction liquid is ejected for a long period of time.

[0017] First, after ejecting the reaction liquid for a long period of time, we tried to remove the thickened substances and precipitates by pressing a member such as a wiper blade or nonwoven fabric against the second liquid application device. However, with a cleaning method that only involved pressing, the thickened substances and precipitates spread over the ejection port surface or entered the ejection port, and it was not possible to fully restore the ejection state of the reaction liquid to its normal state.

[0018] Therefore, the inventors attempted to remove thickened substances and precipitates adhering to the discharge port surface by applying an aqueous maintenance liquid to the discharge port surface where the discharge ports of the second liquid application device are formed, in addition to the cleaning operation of pressing a member such as a wiper blade or nonwoven fabric against the discharge port surface. As a result, it was found that by setting the difference between the surface tension of the reaction liquid and that of the maintenance liquid within a specific range and cleaning the discharge port surface by pressing a wiper blade or the like against the discharge port surface, it is possible to restore the discharge state of the reaction liquid to a normal state and maintain image quality. Specifically, the difference in surface tension is R (mN / m) and the surface tension of the maintenance liquid γ C The absolute value of the difference from (mN / m) is set to 15 mN / m or less. It is presumed that a sufficient cleaning effect was achieved because the thickened substances and precipitates on the discharge port surface were dissolved in the maintenance liquid, making them easy to remove when components such as wiper blades and nonwoven fabrics were pressed against them.

[0019] Surface tension of reaction solution γ R is the surface tension of the maintenance liquid γ C If the difference is greater than 15 mN / m, the maintenance liquid is easily drawn into the outlet of the second liquid depositing device that deposits the reaction liquid. This reduces the amount of maintenance liquid that dissolves the thickened matter on the outlet surface of the second liquid depositing device, making the effect insufficient. R is the surface tension of the maintenance liquid γ C If the difference is smaller than 15 mN / m, the maintenance liquid will tend to draw out the reaction liquid, and the flocculant will be mixed into the maintenance liquid, reducing the cleaning effect and making the remaining liquid more likely to recrystallize and thicken again, which is thought to result in a reduced cleaning effect.

[0020] Therefore, the surface tension of the reaction solution γ R (mN / m) and the surface tension of the maintenance liquid γ C By making the absolute value of the difference between the surface tension (mN / m) and the surface tension (mN / m) 15 mN / m or less, the thickened matter and precipitates attached to the discharge port surface of the second liquid application device are efficiently dissolved by the maintenance liquid. As a result, when a member such as a wiper blade or nonwoven fabric is pressed against the discharge port surface, the thickened matter and precipitates can be easily peeled off from the discharge port surface, so the discharge state of the reaction liquid can be restored to a normal state and image quality can be maintained. Since the time difference between the application of the maintenance liquid and the start of the wiping operation is about several seconds, it is considered that if the surface tension difference is within 15 mN / m, there is little movement or mixing of the reaction liquid and the maintenance liquid on the discharge port surface of the second liquid application device, and the cleaning effect can be fully exhibited. In this specification, the cleaning operation of pressing a member such as a wiper blade or nonwoven fabric against the discharge port surface is also referred to as a "wiping operation."

[0021] In addition, the water content (mass %) in the reaction liquid is 5 times or more the reactant content (mass %). This makes it possible to reduce the amount of thickened matter or precipitates even when the reaction liquid is discharged for a long period of time, making cleaning easier.

[0022] <Inkjet recording method, inkjet recording device, and set of reaction liquid and maintenance liquid> The inkjet recording method of the present invention (hereinafter, also simply referred to as the "recording method") is a recording method for recording an image on a recording medium using an inkjet recording device. The inkjet recording device of the present invention (hereinafter, also simply referred to as the "recording device") can be used as the inkjet recording device used in this recording method.

[0023] The recording method preferably includes a step of ejecting an aqueous ink from the ejection opening of a first liquid application device to apply the aqueous ink to a recording medium, and a step of ejecting a reaction liquid from the ejection opening of a second liquid application device to apply the reaction liquid to the recording medium. Furthermore, the recording method preferably includes a step of applying an aqueous maintenance liquid to an ejection opening surface of the second liquid application device on which the ejection openings are formed, and a step of pressing a first cleaning device against the ejection opening surface of the second liquid application device to clean the ejection opening surface.

[0024] The recording apparatus of the present invention comprises a first liquid application device having an ejection port for ejecting an aqueous ink, and a second liquid application device having an ejection port for ejecting an aqueous reactive liquid containing a reactant that reacts with the aqueous ink. The recording apparatus also comprises a maintenance liquid application device that applies an aqueous maintenance liquid to an ejection port surface on which the ejection ports of the second liquid application device are formed, and a first cleaning device that is pressed against the ejection port surface of the second liquid application device to clean the ejection port surface. The reactive liquid and maintenance liquid used in the recording method and recording apparatus of the present invention have a surface tension γ of the reactive liquid. R (mN / m) and the surface tension of the maintenance liquid γ C The absolute value of the difference between the absolute value of the water content (mass%) and the absolute value of the reactant content (mass%) is 15 mN / m or less.

[0025] The set of the reaction liquid and the maintenance liquid of the present invention is a set of the reaction liquid and the maintenance liquid used in the ink jet recording device of the present invention. R(mN / m) and the surface tension of the maintenance liquid γ C The absolute value of the difference between the absolute value of the water content (mass%) and the absolute value of the reactant content (mass%) is 15 mN / m or less.

[0026] (Inkjet recording device) The inkjet recording apparatus will be described in detail below with reference to the drawings. Fig. 1 is a schematic diagram showing one embodiment of the inkjet recording apparatus of the present invention. The inkjet recording apparatus of this embodiment is an inkjet recording apparatus that records an image on a recording medium using ink and a reaction liquid containing a reactant that reacts with the ink. The X direction, Y direction, and Z direction respectively indicate the width direction (total length direction), depth direction, and height direction of the inkjet recording apparatus. The recording medium is transported in the X direction.

[0027] The inkjet recording apparatus 100 of the embodiment shown in FIG. 1 is configured to include a recording unit 1000, a heating unit 2000, a fixing unit 3000, a cooling unit 4000, an inverting unit 5000, and a paper discharge unit 6000. In the recording unit 1000, various liquids are applied by a liquid application unit 1200 to a recording medium 1100 conveyed from a paper feeder 1400 by a conveying member 1300. In the heating unit 2000, the liquid applied to the recording medium 1100 is heated by a heating unit 2100, and volatile components such as water in the liquid are evaporated and dried. In the fixing unit 3000, a fixing member 3100 is brought into contact with the area of ​​the recording medium 1100 to which the liquid has been applied, and heated to promote fixing of the image to the recording medium 1100. The recording medium 1100 is then cooled by a cooling member 4100 of the cooling unit 4000. When an image is to be recorded on the back side following the front side (recording surface), the recording medium 1100 is first inverted by an inversion device 5100 of the inversion section 5000. Next, an image is recorded on the back side in the same manner as for the front side, and then the recording medium is transported by a transport member 6100 of the paper discharge section 6000 and stacked and stored in the recording medium storage section 6200. In addition, the liquid deposition performance of the liquid deposition device 1200 is restored by a maintenance device 1600. Here, a configuration having a heating section 2000 and a fixing section 3000 will be described as an example, but the heating section and the fixing section may be omitted depending on the recording conditions (type of ink or recording medium, recording speed, etc.).

[0028] Any recording medium may be used as the recording medium 1100. For example, recording media having ink absorbency (permeability) such as recording media without a coating layer, such as plain paper, uncoated paper, and synthetic paper, and recording media with a coating layer, such as printing paper, glossy paper, and art paper, may be used. In addition, recording media having no permeability, such as films or sheets made of resin materials such as polyvinyl chloride (PVC) and polyethylene terephthalate (PET), may be used. The basis weight (g / m2) of the recording medium 1100 may be determined by the following formula: 2 ) is 30g / m 2 More than 500g / m 2 It is preferable that the thickness is less than 50 g / m 2 More than 450g / m 2 It is even more preferable that:

[0029] [Recording Section] The recording unit 1000 includes a liquid applying device 1200. The liquid applying device 1200 includes a reaction liquid applying device 1201 and an ink applying device 1202. The reaction liquid applying device 1201 shown in FIG. 1 is a unit using an inkjet type ejection head. The reaction liquid applied by the reaction liquid applying device 1201 may be applied either before or after the ink application as long as it can come into contact with the ink on the recording medium 1100. However, in order to record high-quality images on various recording media having different liquid absorption characteristics, it is preferable to apply the reaction liquid before the ink application. As the ink applying device 1202, an inkjet type ejection head (recording head) is used. In the present invention, the ink applying device may be referred to as a "first liquid applying device" and the reaction liquid applying device may be referred to as a "second liquid applying device", and they may be collectively referred to simply as a "liquid applying device". The ejection method of the ejection head as the liquid applying device 1200 can be a method of ejecting liquid by generating film boiling in the liquid using an electro-thermal converter to form bubbles, a method of ejecting liquid using an electro-mechanical converter, etc. In the recording method and recording device of the present invention, for example, using the liquid applying device 1200, an image can be recorded on a recording medium by ejecting ink from the ejection port of a first liquid applying device and ejecting a reaction liquid from the ejection port of a second liquid applying device.

[0030] The liquid applying device 1200 is a line head extending in the Y direction, and the ejection ports are arranged in a range that covers the image recording area of ​​the recording medium with the maximum usable width. The ejection head has an ejection port surface 1207 (FIG. 3) with ejection ports formed thereon (on the recording medium 1100 side), and the ejection port surface faces the recording medium 1100 with a very small distance of about several millimeters. The liquid applying device 1200 shown in FIG. 1 is a line head, but a serial head or the like may also be used. Compared to a serial head, a line head has fewer timings at which the ejection port surface can be cleaned, and the cleaning range is longer. Therefore, a more effective cleaning method is required for the line head, but with the configuration of the present invention, a sufficient cleaning effect can be obtained even with a line head. Therefore, it is preferable that the second liquid applying device has a line head.

[0031] A plurality of ink applicators 1202 may be provided to apply ink of each color to the recording medium 1100. For example, when recording images of each color using yellow ink, magenta ink, cyan ink, and black ink, four ink applicators 1202 for ejecting the above four types of ink are arranged side by side in the X direction. Hereinafter, the ink and the reaction liquid may be collectively referred to as "liquid".

[0032] FIG. 2 is a perspective view showing an example of a liquid applying device. The liquid applying device 1200 shown in FIG. 2 is a line head, and a plurality of ejection element substrates 1203 each having an ejection port array are arranged in a straight line. A plurality of ejection port arrays are arranged on the ejection element substrate 1203. A protective member (hereinafter, also referred to as a "first protective member") 1224 for protecting the plurality of ejection element substrates 1203 is arranged on the outer periphery of the ejection element substrates 1203 arranged in a straight line. In addition, when the first protective member 1224 is provided, the ejection port surface 1207 also includes the surface area of ​​the first protective member 1224. In addition, the liquid applying device 1200 has first positioning portions 1225 used for positioning a capping unit described later on both ends. Specifically, a first contact portion 1225a, which is a recess having a conical slope, is provided on the front side of the drawing in the longitudinal direction (Y direction) of the liquid applying device 1200. Further, a second contact portion 1225b which is a groove portion having two V-shaped flat surfaces, and a third contact portion 1225c which is a flat surface are provided on the rear side of the liquid application device 1200 in the longitudinal direction (Y direction) in the drawing.

[0033] FIG. 3 is a cross-sectional perspective view showing an example of a discharge element substrate. The discharge element substrate 1203 shown in FIG. 3 includes a discharge port forming member 1206 having a discharge port 1204 opened therein, and a substrate 1205 having discharge elements (not shown) disposed thereon. The discharge port forming member 1206 and the substrate 1205 are laminated to form a first flow path 1208 and a second flow path 1209 through which liquid flows. The first flow path 1208 is a region from an inlet 1212 through which liquid flows in from an inflow path 1210 to a portion between the discharge port 1204 and the discharge element (FIG. 4, liquid chamber 1508). The second flow path 1209 is a region from a portion between the discharge port 1204 and the discharge element (FIG. 4, liquid chamber 1508) to an outlet 1213 through which liquid flows out to an outlet path 1211. For example, by creating a pressure difference between the inlet 1212 and the outlet 1213, such as the inlet 1212 having a high pressure and the outlet 1213 having a low pressure, liquid can be made to flow from the high pressure to the low pressure (in the direction of the arrow in FIG. 3). The liquid that has passed through the inlet 1210 and the inlet 1212 enters the first flow path 1208. Then, the liquid that has passed through the portion between the outlet 1204 and the ejection element (liquid chamber 1508 in FIG. 4) flows through the second flow path 1209 and the outlet 1213 to the outlet path 1211.

[0034] [Supply system] FIG. 4 is a schematic diagram showing an example of a supply system for liquid such as ink. The supply unit 1500 of the liquid deposition apparatus 1200 shown in FIG. 4 is configured to include a first circulation pump (high pressure side) 1501, a first circulation pump (low pressure side) 1502, a sub-tank 1503, and a second circulation pump 1505. The sub-tank 1503 connected to a main tank 1504, which is a liquid storage unit, has an air communication port (not shown) and can discharge air bubbles mixed in the liquid to the outside of the circulation system. The sub-tank 1503 is also connected to a refill pump 1506. The liquid is consumed in the liquid deposition apparatus 1200 by discharging (discharging) the liquid from the discharge port for image recording, suction recovery, etc. The refill pump 1506 transfers the liquid corresponding to the consumed amount from the main tank 1504 to the sub-tank 1503.

[0035] The first circulation pump (high pressure side) 1501 and the first circulation pump (low pressure side) 1502 cause the liquid in the liquid deposition device 1200, which is caused to flow out from a connection part (inlet part) 1507, to flow into a sub tank 1503. It is preferable to use a positive displacement pump having a quantitative liquid delivery capability as the first circulation pump (high pressure side) 1501, the first circulation pump (low pressure side) 1502, and the second circulation pump 1505. Examples of such a positive displacement pump include a tube pump, a gear pump, a diaphragm pump, and a syringe pump. When the ejection element substrate 1203 is driven, the first circulation pump (high pressure side) 1501 and the first circulation pump (low pressure side) 1502 can cause the liquid to flow from a common inlet channel 1514 toward a common outlet channel 1515.

[0036] The negative pressure control unit 1509 includes two pressure adjustment mechanisms with mutually different control pressures. The pressure adjustment mechanism (high pressure side) 1510 and the pressure adjustment mechanism (low pressure side) 1511 are connected to a common inflow channel 1514 and a common outflow channel 1515 in the ejection element substrate 1203 via a supply unit 1513 provided with a filter 1512 for removing foreign matter from the liquid. The ejection element substrate 1203 is provided with the common inflow channel 1514, the common outflow channel 1515, and the inflow channel 1210 and the outflow channel 1211 that communicate with the liquid chamber 1508, which is a portion between the ejection port 1204 and the ejection element (not shown). Since the inflow channel 1210 and the outflow channel 1211 communicate with the common inflow channel 1514 and the common outflow channel 1515, respectively, a flow (arrow in FIG. 4) occurs in which part of the liquid flows from the common inflow channel 1514 through the inside of the liquid chamber 1508 to the common outflow channel 1515. The arrows in Fig. 3 indicate the flow of liquid inside the liquid chamber 1508. That is, as shown in Fig. 3, the liquid in the first flow path 1208 flows into the second flow path 1209 via the gap between the ejection port 1204 and the ejection element.

[0037] 4, a pressure adjustment mechanism (high pressure side) 1510 is connected to the common inflow channel 1514, and a pressure adjustment mechanism (low pressure side) 1511 is connected to the common outflow channel 1515, so that a pressure difference occurs between the inflow channel 1210 and the outflow channel 1211. As a result, a pressure difference also occurs between an inlet 1212 (FIG. 3) communicating with the inflow channel 1210, and an outlet 1213 (FIG. 3) communicating with the outflow channel 1211. When liquid is caused to flow by the pressure difference between the inlet 1212 and the outlet 1213, it is preferable to control the flow velocity (mm / s) of the liquid to be 0.1 mm / s or more and 10.0 mm / s or less.

[0038] [Transport system] As shown in FIG. 1, the recording unit 1000 is configured to include a liquid applying device 1200 and a conveying member 1300 that conveys the recording medium 1100. The liquid applying device 1200 applies a reaction liquid and ink to a desired position of the recording medium 1100 conveyed by the conveying member 1300. Each liquid applying device 1200 receives an image signal of recording data and applies the necessary reaction liquid and ink to each position. FIG. 1 shows the conveying member 1300 in the form of a conveying belt, but a spur, a conveying drum, or the like may be used as long as it has the function of conveying the recording medium 1100. In order to improve the conveying accuracy, a material that can fix the recording medium 1100 can be used as the conveying member 1300. Specifically, a method of providing a hole in the conveying member 1300 and fixing the recording medium 1100 by sucking from the back side, a method of forming the conveying member 1300 from an appropriate material and fixing the recording medium 1100 by electrostatic adsorption, etc. can be mentioned.

[0039] [Maintenance system] As shown in FIG. 1, the recording unit 1000 is configured to include a maintenance device 1600. The maintenance device 1600 performs maintenance to restore the liquid ejection performance of the liquid deposition device 1200. The maintenance device 1600 is configured to include, for example, a capping unit 1701 (see FIG. 5) that protects the ejection port surface 1207 (see FIG. 3) and a cleaning unit 1801 (see FIG. 6) that cleans the ejection port surface 1207 (see FIG. 3). The maintenance device 1600 further includes a drive device and rails (not shown), and is configured to be movable in the X direction in FIG. 1 along the rails. When maintenance of the liquid deposition device 1200 is performed, the maintenance device moves directly below the liquid deposition device 1200, and when maintenance of the liquid deposition device 1200 is not performed, the maintenance device moves to a position retreated from directly below the liquid deposition device 1200.

[0040] Next, the configuration of the maintenance device 1600 will be described. The maintenance device 1600 shown in Fig. 1 is equipped with a capping tray 1700 having a capping unit 1701 (see Fig. 5) and a cleaning tray 1800 having a cleaning unit 1801 (see Fig. 6). The capping tray 1700 and the cleaning tray 1800 are configured to be movable in the longitudinal direction of the inkjet recording apparatus (X direction in Fig. 1) by a driving motor (not shown) and rails provided on the housing of the inkjet recording apparatus 100.

[0041] FIG. 5 is a perspective view showing an example of a capping tray 1700. The capping tray 1700 has a plurality of capping units 1701 for protecting the ejection port surfaces of the reaction liquid applying device 1201 and the ink applying device 1202, which are the liquid applying device 1200. The capping unit 1701 has a plurality of spherical second positioning portions 1702 used for positioning the capping unit 1701 with respect to the liquid applying device 1200. One second positioning portion 1702 is disposed at one end in the longitudinal direction of one capping unit 1701, and two second positioning portions 1702 are disposed at the other end. The positions of the liquid applying device 1200 and the capping unit 1701 are regulated by abutment between the first positioning portions 1225 (see FIG. 2) provided at both ends of the liquid applying device 1200 and the second positioning portions 1702 of the capping unit 1701. The capping unit 1701 covers the ejection port surface side of the liquid deposition apparatus 1200 when the liquid deposition apparatus 1200 is not in use, thereby protecting the ejection port surface 1207 (see FIG. 3) of the liquid deposition apparatus 1200 and enabling suction by a suction apparatus described later.

[0042] A capping liquid supply flow path 1703 shown in Fig. 5 is a flow path through which the maintenance liquid is supplied to the capping unit 1701. As shown in Fig. 5, the capping liquid supply flow path 1703 of the capping unit 1701 corresponding to each liquid deposition device 1200 includes a plurality of cap upstream three-way valves 1704, and has a three-way valve upstream flow path and a three-way valve downstream flow path. The upstream side (the maintenance liquid sub-tank 1603 (see Fig. 7) side) of each cap upstream three-way valve 1704 is the three-way valve upstream flow path, and the downstream side is the three-way valve downstream flow path. The plurality of cap upstream three-way valves 1704 are supported by a three-way valve support member 1705 by a fixing method not shown.

[0043] FIG. 6 is a perspective view showing an example of a cleaning tray 1800. The cleaning tray 1800 has a plurality of cleaning units 1801 for cleaning the ejection port surface 1207. The cleaning tray 1800 also has a plurality of spherical third positioning parts 1802 used for positioning the cleaning units 1801 with respect to the liquid deposition device 1200. The third positioning parts 1802 are arranged on beam members 1803a and 1803b arranged on both sides of the width direction (Y direction in FIG. 1) of the recording medium 1100 to be conveyed inside the cleaning tray 1800. Three third positioning parts 1802 are required to position one liquid deposition device 1200 with respect to the cleaning tray 1800. Specifically, one third positioning part 1802 is arranged on the beam member 1803a on the front side of the drawing in the Y direction in FIG. 1 in the cleaning tray 1800, and two third positioning parts 1802 are arranged on the beam member 1803b on the back side of the drawing. The positions of the liquid deposition apparatus 1200 and the cleaning tray 1800 are regulated by abutment between first positioning portions 1225 provided on both ends of the liquid deposition apparatus 1200 and third positioning portions 1802 of the cleaning tray 1800 .

[0044] The configuration for positioning the first positioning portion 1225 and the second positioning portion 1702 and / or the third positioning portion 1802 is not limited to a configuration using a spherical positioning portion. For example, a configuration in which a part of the liquid deposition device 1200 is abutted against the inside of the capping unit 1701 or the cleaning tray 1800 may be used. Also, for example, a configuration in which the liquid deposition device 1200 and a hole provided in the capping unit 1701 or the cleaning tray 1800 are positioned using a pin may be used.

[0045] The cleaning unit 1801 includes a maintenance liquid applying device 1850, a liquid removing device 1860, and a negative pressure applying device 1870. The maintenance liquid applying device 1850 applies the maintenance liquid to the discharge port surface 1207 of the liquid applying device 1200. The liquid removing device 1860 is a device for removing the maintenance liquid from the discharge port surface 1207 of the liquid applying device 1200, and is a device capable of removing the liquid, paper powder, maintenance liquid, and the like attached to the liquid applying device 1200. The negative pressure applying device 1870 is a device for removing the liquid, such as the reaction liquid, adhered near the discharge port, and removing bubbles in the first flow path 1208 and the second flow path 1209 by applying a negative pressure to the discharge port surface 1207 of the liquid applying device 1200 to suck the liquid. As shown in FIG. 6, the cleaning unit 1801 is configured to be movable along a wiping direction (direction D in FIG. 6) perpendicular to the transport direction of the recording medium 1100. The cleaning unit 1801 removes the liquid, paper powder, maintenance liquid, and the like from the ejection port surface 1207 of the liquid deposition device 1200 by means of a maintenance liquid deposition device 1850 , a liquid removal device 1860 , and a negative pressure deposition device 1870 .

[0046] The application of maintenance liquid by the maintenance liquid application device 1850 to the discharge port surface 1207 may be performed at least to the discharge port surface of the second liquid application device 1201, but may also be performed to the discharge port surface of the first liquid application device 1202. By applying the maintenance liquid to the discharge port surface 1207 of the second liquid application device 1202 by the maintenance liquid application device 1850, if any thickened matter or liquid spillage due to the mist of the reaction liquid adheres to the discharge port surface 1207, it is possible to dissolve them with the maintenance liquid.

[0047] In the present invention, a liquid removing device that is pressed against the discharge port surface of a second liquid applying device (reaction liquid applying device) 1201 having a discharge port that discharges a reaction liquid containing a reactant that reacts with an aqueous ink and cleans the discharge port surface may be described as a "first cleaning device". A liquid removing device 1860 (first cleaning device) that is pressed against the discharge port surface 1207 of the second liquid applying device 1201 to perform cleaning can remove thickened substances dissolved in the maintenance liquid and liquid spillage from the discharge port surface 1207. From the viewpoint of enhancing the cleaning effect in this way, as described later, it is preferable that the first cleaning device has a wiper blade formed of a flexible material as a member that is pressed against the discharge port surface 1207 of the second liquid applying device 1201. In addition, it is preferable that the first cleaning device cleans the discharge port surface 1207 of the second liquid applying device 1201 after the maintenance liquid is applied to the discharge port surface 1207 of the second liquid applying device 1201.

[0048] In the present invention, the negative pressure applying device that is pressed against the discharge port surface of the second liquid applying device 1201 to clean the discharge port surface may be referred to as a "second cleaning device". The second cleaning device may be omitted, but from the viewpoint of enhancing the cleaning effect, it is preferable that the recording apparatus further includes a second cleaning device that is pressed against the discharge port surface 1207 of the second liquid applying device 1201 to clean the discharge port surface 1207. By using the negative pressure applying device 1870 as the second cleaning device, the second cleaning device is configured to be able to apply negative pressure, and it is possible to further enhance the cleaning effect. In addition, as described later, it is preferable that the second cleaning device has a flexible member as a member that is pressed against the discharge port surface 1207 of the second liquid applying device 1201 so that the liquid and the like can be efficiently removed by the negative pressure. Furthermore, it is preferable that after the maintenance liquid is applied to the discharge port surface, the second cleaning device cleans the discharge port surface of the second liquid applying device following the cleaning by the first cleaning device.

[0049] (Maintenance equipment supply system) 7, a supply system such as a maintenance liquid supply path, a suction flow path, and a waste liquid flow path of the maintenance device 1600 will be described. The maintenance liquid is sent from a maintenance liquid pack 1601 to a maintenance liquid sub-tank 1603 by a pump 1602. From the maintenance liquid sub-tank 1603, the maintenance liquid can be sent to the capping unit 1701, the maintenance liquid deposition device 1850, and the negative pressure application device 1870 by a maintenance liquid supply pump 1604. The maintenance liquid supply pump 1604 is provided in a maintenance liquid and negative pressure supply unit 1650 (Y: yellow, M: magenta, C: cyan, Bk: black, P: reaction liquid) corresponding to the liquid deposition device 1200. In addition, the timing of supplying the maintenance liquid to the capping unit 1701, the maintenance liquid deposition device 1850, and the negative pressure application device 1870 can be controlled by each of opening and closing valves 1605, 1606, and 1607.

[0050] Negative pressure is applied to the capping unit 1701 and the negative pressure applying device 1870 by a suction pump 1616 connected to a negative pressure tank 1615. Negative pressure can be applied to each of the capping units 1701 and each of the negative pressure applying devices 1870 through the opening and closing valves 1617, 1618, and 1619 via each negative pressure tank 1615. When liquid is sucked using the capping unit 1701 and the negative pressure applying device 1870, waste liquid sucked from the liquid applying device 1200 is stored in the drain sub-tank 1613 from the negative pressure tank 1615 by the pump 1614. Then, the waste liquid is stored in the waste liquid tank 1611 from the drain sub-tank 1613 by the pump 1612. In addition, a collection tray 1630 for collecting the maintenance liquid overflowing from the maintenance liquid applying device 1850 is provided in the supply system, and the excess maintenance liquid is sent to the drain sub-tank 1613 by the pump 1621. The capacity of the waste liquid tank 1611 is detected by a waste liquid tank detection sensor (not shown), and when the capacity approaches the upper limit, the user is prompted to replace the waste liquid tank 1611.

[0051] The waste liquid from the reaction liquid deposition device 1201 is accommodated in a drain sub-tank 1633 for the reaction liquid by a pump 1634, separately from the waste liquid flow path from the ink deposition device 1202, and is stored in a waste liquid tank 1631 for the reaction liquid by a pump 1632. This prevents the reaction liquid and the ink from mixing in the waste liquid flow path, making it possible to suppress clogging of the flow path due to ink solidifying in the flow path.

[0052] As in the supply system described above, the maintenance liquid and negative pressure supply unit 1650 corresponding to each liquid deposition device is provided with a maintenance liquid supply pump 1604 and on-off valves 1605, 1606, and 1607 for controlling the supply of maintenance liquid to each flow path. The maintenance liquid and negative pressure supply unit 1650 is also provided with a negative pressure tank 1615, a suction pump 1616 for suction, and on-off valves 1617, 1618, and 1619 for controlling the application of negative pressure to each part. The maintenance liquid and negative pressure supply unit 1650 may be provided with a filter 1622.

[0053] (Operation to prevent flow path sticking of maintenance device) The operation of the maintenance device for preventing the flow passage from sticking will be described with reference to FIG. 7. When the liquid is sucked from the liquid application device 1200 using the capping unit 1701, the liquid is prevented from sticking in the capping unit 1701 and in the supply system leading to the waste liquid tanks 1611 and 1631, causing blockage of the flow passage. For this purpose, after sucking the liquid, the liquid application device 1200 is separated from the capping unit 1701, and then an empty suction operation is performed. As a result, the liquid inside the capping unit 1701 and in the flow passage is sent to the waste liquid tanks 1611 and 1631, and then the cap upstream three-way valve 1704 is opened, and the maintenance liquid is filled in the capping unit 1701 through the valve. Next, the empty suction operation is performed in the same manner to send the maintenance liquid to the waste liquid tanks 1611 and 1631, thereby cleaning the inside of the capping unit 1701 and in the flow passage, and preventing sticking in the supply system. In order to achieve a high level of sticking prevention, it is preferable to perform the cleaning process using the maintenance liquid multiple times, particularly about 3 to 5 times.

[0054] The liquid can be preliminarily discharged from the liquid deposition device 1200 to the capping unit 1701. The preliminarily discharge is an operation performed to stabilize the discharge state when replacing the liquid deposition device 1200 or performing maintenance on the liquid deposition device, or to normalize the discharge state at any timing, such as before the start of recording, during recording, or after recording. When performing preliminarily discharge with the maintenance device, the cap upstream three-way valve 1704 is opened, the capping unit 1701 is filled with the maintenance liquid, and then a predetermined amount of liquid is preliminarily discharged from the liquid deposition device 1200 into the capping unit 1701. Thereafter, an idle suction operation is performed to send the liquid inside the capping unit 1701 and in the flow path together with the maintenance liquid to the waste liquid tanks 1611 and 1631. If necessary, a flow path cleaning process may be performed in the same manner as described above, in which the cap upstream three-way valve 1704 is opened, the capping unit 1701 is filled with the maintenance liquid, and then an idle suction operation is performed in the same manner to send the maintenance liquid to the waste liquid tanks 1611 and 1631.

[0055] (Capping of liquid application device) The capping operation of the liquid applying device will be described with reference to FIG. 5 and FIG. 7. When the recording operation is completed and no recording is performed for a certain period of time, the liquid applying device 1200 preferably caps the discharge port surface to suppress evaporation in order to suppress adhesion of the liquid in the flow path. The liquid applying device 1200 can be abutted against the capping unit 1701 shown in FIG. 5 to be capped. Before the capping unit 1701 is abutted against the capping unit 1701, the cap upstream three-way valve 1704 shown in FIG. 7 is opened to fill the capping unit 1701 with the maintenance liquid. Then, the liquid applying device 1200 is abutted against the capping unit 1701 to cap it, thereby effectively suppressing adhesion of the liquid in the flow path of the liquid applying device 1200. Even if the capping state continues for a certain period of time, if the liquid applying device 1200 has a liquid circulation mechanism (not shown) in the flow path, the liquid can be stably discharged from the initial stage of resuming recording by the liquid circulation operation in the flow path in the recording preparation operation.

[0056] (Cleaning unit configuration) FIG. 8 is an enlarged perspective view of the dashed line portion shown in FIG. 6, and shows the configuration of a cleaning unit 1801 arranged in a cleaning tray 1800. The cleaning unit 1801 is configured with a maintenance liquid applying device 1850, a liquid removing device (first cleaning device) 1860, and a negative pressure applying device (second cleaning device) 1870. The liquid removing device 1860 is configured with a wiper blade 1861 formed of a flexible material such as urethane rubber. FIG. 8 shows an example in which two wiper blades are arranged, but the size and number of wiper blades can be set in consideration of the structure and removal performance of the discharge port surface of the liquid applying device 1200. The negative pressure applying device 1870 is configured with a flexible member 1871, and it is preferable to select a material that can efficiently remove liquid, bubbles, etc. by negative pressure when it comes into contact with the discharge port surface 1207 of the liquid applying device 1200.

[0057] 9A to 9C are schematic diagrams showing a configuration of a maintenance liquid deposition device 1850. FIG. 9A is a perspective view showing the maintenance liquid deposition device 1850. FIG. 9B is a cross-sectional view of the maintenance liquid deposition device 1850 shown in FIG. 9A taken along line AA. FIG. 9C is a cross-sectional view of the maintenance liquid deposition device 1850 shown in FIG. 9A taken along line BB. The maintenance liquid deposition device 1850 has a flexible maintenance liquid deposition member 1851. The maintenance liquid deposition device 1850 also has a maintenance liquid deposition member holder 1852 that holds the maintenance liquid deposition member 1851 and has a flow path formed therein for supplying the maintenance liquid to the inside of the maintenance liquid deposition member 1851. The maintenance liquid deposition device 1850 also has a maintenance liquid deposition member cover 1853 that covers the maintenance liquid deposition member 1851. The maintenance liquid deposition member 1851 is held between the maintenance liquid deposition member holder 1852 and the maintenance liquid deposition member cover 1853. 9B, a maintenance liquid supply tube 1854 is connected to the maintenance liquid application member holder 1852. The maintenance liquid supplied from the maintenance liquid supply tube 1854 passes through the maintenance liquid application member holder 1852, and is applied to the discharge port surface 1207 by the maintenance liquid application member 1851. The maintenance liquid application device 1850 also has a biasing member 1855, and while the maintenance liquid is being applied to the discharge port surface 1207, the maintenance liquid application member 1851 is pressed against the discharge port surface 1207. The maintenance liquid application device 1850 is attached to the cleaning tray 1800 by a support portion 1857.

[0058] As shown in FIGS. 9A to 9C, the maintenance liquid application member 1851 has a notch in a part of the surface that contacts the ejection port surface 1207. The maintenance liquid application member 1851 has a surface 1851a (first surface) on the upstream side (+Y direction) and a surface 1851c (third surface) on the downstream side (-Y direction) with respect to the application direction of the maintenance liquid, and also has a surface 1851b (second surface) that intersects with the first surface 1851a. When the maintenance liquid is applied to the ejection port surface 1207, the first surface 1851a on the upstream side with respect to the application direction of the maintenance liquid and the second surface 1851b that intersects with the first surface 1851a come into contact with the ejection port surface 1207 and are pressed against it. At this time, a gap 1856 is formed between the third surface 1851c on the downstream side with respect to the application direction of the maintenance liquid and the ejection port surface 1207. In the illustrated example, the contact length of the first surface 1851a with the ejection port surface 1207 is longer than the contact length of the second surface 1851b with the ejection port surface 1207, making it easier for the maintenance liquid application member 1851 to conform to the surface shape of the ejection port surface 1207.

[0059] 9B, a first surface 1851a on the upstream side in the direction in which the maintenance liquid is applied, which contacts the ejection port surface 1207, is formed to be thinner than a base portion 1851d thereof. As shown in FIG. 9C, a second surface 1851b that intersects with the first surface 1851a on the upstream side in the direction in which the maintenance liquid is applied, is formed to be thinner than a base portion 1851e thereof. With these configurations, the tip of the maintenance liquid application member 1851 has a thin wall thickness and is easily deformed. Therefore, when the maintenance liquid application member 1851 is pressed against the ejection port surface 1207 having projections and recesses, it is possible for the maintenance liquid application member 1851 to follow the projections and recesses of the ejection port surface 1207.

[0060] 10 is a schematic diagram showing the positional relationship between the liquid deposition device and the cleaning unit. In this example, a state in which a maintenance liquid deposition device 1850, a liquid removal device (first cleaning device) 1860, and a negative pressure application device (second cleaning device) 1870 are in contact with the discharge port surface 1207 of the liquid deposition device 1200 is shown. The maintenance liquid deposition device 1850, the liquid removal device 1860, and the negative pressure application device 1870 are each configured to be able to come into contact with or separate from the discharge port surface 1207. Therefore, each of these can be swept in the longitudinal direction of the liquid deposition device 1200 to deposit maintenance liquid, remove the liquid or the mixture of the maintenance liquid by suction, and wipe the liquid deposition device 1200.

[0061] The cleaning process of the discharge port surface 1207 of the liquid deposition device 1200 will be described. As an example of efficient cleaning, FIG. 11 shows a schematic diagram of an example of the cleaning operation of the liquid deposition device 1200. The present invention is not limited to this method. First, a maintenance liquid deposition device 1850 having a supply port for depositing a maintenance liquid is swept in a state in which the maintenance liquid is in contact with the liquid deposition device 1200, so that the maintenance liquid is deposited on the discharge port surface 1207 and the first protective member 1224 (FIG. 11(a)). Next, a liquid removal device 1860 is swept in a state in which the liquid removal device 1860 is in contact with the discharge port surface 1207 and the first protective member 1224, so that the liquid adhering to the discharge port surface 1207 of the liquid deposition device 1200 together with the maintenance liquid previously deposited is wiped off (FIG. 11(b)). By sweeping the negative pressure applying device 1870 while it is in contact with the discharge port surface 1207 of the liquid applying device 1200, it is possible to remove liquid that has solidified near the discharge ports present on the discharge port surface 1207 and to remove bubbles within the flow paths (FIG. 11(c)). Each step in FIG. 11(a) to (c) may be performed in this order, or each step may be performed in parallel.

[0062] Furthermore, when the liquid removing device 1860 is swept while in contact with the ejection port surface 1207 and the first protective member 1224 to wipe off liquid and the like adhering to the ejection port surface 1207, the sweeping direction of the liquid removing device 1860 may be either the +Y direction or the -Y direction in Fig. 6. Similarly, when the negative pressure applying device 1870 is swept while in contact with the ejection port surface 1207 to remove solidified liquid present on the ejection port surface 1207, the sweeping direction of the negative pressure applying device 1870 may be either the +Y direction or the -Y direction in Fig. 6.

[0063] Also, it is preferable that the liquid applying device 1200 has a protective member (hereinafter, also referred to as "second protective member") for protecting the discharge port surface 1207 of the discharge element substrate 1203. That is, it is preferable that the liquid applying device 1200 has a second protective member for protecting the discharge port surface 1207. The second protective member can have an opening corresponding to a discharge port array in which a plurality of discharge ports 1204 are arranged in a predetermined direction. Specifically, a second protective member having a rectangular opening corresponding to the discharge port array is bonded to the discharge port surface 1207 by an adhesive. With such a configuration, when the recording medium 1100 floats up during transportation, the second protective member plays a role of suppressing contact between the recording medium 1100 and the discharge element substrate 1203, and damage to the liquid applying device 1200 can be suppressed. Therefore, it is preferable that the second protective member has sufficient mechanical strength, and for example, a metal material such as stainless steel or aluminum, silicone, or alumina can be suitably used as a material.

[0064] The second protective member has rectangular openings formed therein corresponding to the rows of ejection ports. The openings can be formed to correspond to any number of rows of ejection ports, but it is preferable that one second protective member has a plurality of openings. It is preferable that one opening is formed for one row of ejection ports.

[0065] Furthermore, it is preferable that the length of the opening of the second protective member in the direction substantially intersecting with the direction of the ejection port array is 250 μm or more and less than the interval between adjacent ejection port arrays, and the thickness of the second protective member is less than 50 μm. This allows the maintenance device 1600 of the recording device to more suitably recover the liquid on the ejection port surface 1207 of the liquid deposition device 1200 when the maintenance device 1600 contacts the liquid deposition device 1200 during maintenance. Note that, in the case where the second protective member is provided, the ejection port surface 1207 also includes the surface area of ​​the second protective member.

[0066] [Heating section] As shown in Fig. 1, the heating section 2000 is configured to include a heating device 2100 and a transport member 2200. The recording medium 1100, to which the reaction liquid and ink have been applied and an image has been recorded, is heated by the heating device 2100 while being transported by the transport member 2200, thereby evaporating and drying the liquid components of the image. It is preferable to further include a drying step between the ink application step and the fixing step, in which the recording medium to which the ink has been applied is heated in a non-contact manner to dry the ink. By including such a drying step, deformation (cockling and curling) of the recording medium 1100 can be effectively suppressed.

[0067] The heating device 2100 may have any configuration as long as it can heat the recording medium 1100, and various conventionally known devices such as a hot air dryer and a heater can be used. Among them, the use of a non-contact heater such as an electric heating wire or infrared heater is preferable from the standpoint of safety and energy efficiency. In addition, if a mechanism for blowing hot air with a built-in fan for spraying heated gas onto the recording medium 1100 is used, the drying efficiency can be easily improved.

[0068] Regarding the method of heating, the recording medium 1100 may be heated from the side (recording surface (front side)) to which the reaction liquid and the ink are applied, or from the back side, or from both sides. The conveying member 2200 may be provided with a heating function. FIG. 1 shows the conveying member 2200 using a conveying belt, but a spur, conveying drum, or the like may be used as long as it has the function of conveying the recording medium 1100. From the viewpoint of suppressing deformation of the recording medium 1100 due to heating, it is preferable to have a configuration in which the recording medium 1100 is conveyed while being in close contact with the conveying member 2200 by blowing air from the heating unit 2000, or to have a mechanism for fixing the recording medium to the conveying member 2200. Specifically, a method of providing a hole in the conveying member 2200 and fixing the recording medium 1100 by suction from the back side, a method of forming the conveying member 2200 from an appropriate material, and fixing the recording medium 1100 by electrostatic adsorption, etc. can be mentioned.

[0069] The heating temperature is preferably set so as to quickly evaporate the liquid components and not to over-dry the recording medium 1100 in terms of suppressing deformation of the recording medium. The temperature of the drying means can be set so that the recording medium reaches a desired temperature, taking into consideration the conveying speed and the environmental temperature. Specifically, the temperature of the drying means (such as hot air) is preferably set to 40°C or higher and 100°C or lower, and more preferably 60°C or higher and 80°C or lower. In addition, when the recording medium 1100 is heated by blowing heated gas, the wind speed is preferably set to 1 m / s or higher and 100 m / s or lower. The temperature of the wind such as the hot air can be measured using a K-type thermocouple thermometer. A specific measuring device can be, for example, the product name "AD-5605H" (manufactured by A&D).

[0070] Fig. 12 is a schematic diagram showing another example of the heating section. Here, the difference from the heating section shown in Fig. 1 and described above will be described. The heating section 2000 shown in Fig. 12 includes a first heating device 2101 and a second heating device 2102, and a first conveying member 2201 and a second conveying member 2202 arranged opposite the first heating device 2101 and the second heating device 2102, respectively.

[0071] The first conveying member 2201 does not have a mechanism for sucking and fixing the recording medium 1100. The recording medium 1100 is pressed against the first conveying member 2201 by hot air from the first heating device 2101 to convey the recording medium 1100. This allows the recording medium 1100 to be transferred with high precision from the conveying member 1300 (FIG. 1) to the first conveying member 2201, and from the first conveying member 2201 to the second conveying member 2202. Furthermore, it is possible to reduce conveyance deviations caused by slight differences in conveying speed between the conveying member 1300 (FIG. 1) and the first conveying member 2201. On the other hand, a conveying belt having holes that can pass gas is used as the second conveying member 2202, and the recording medium 1100 is conveyed while being fixed to the second conveying member 2202 by a suction mechanism (not shown).

[0072] An air knife 2300 is disposed between the transport member 1300 (FIG. 1) and the first transport member 2201, between the first transport member 2201 and the second transport member 2202, and between the second transport member 2202 and the transport member 3200 (FIG. 1). The air pressure from the air knife 2300 prevents the leading edge of the transported recording medium 1100 from floating up. This makes it possible to prevent the leading edge of the recording medium 1100 from colliding with the first heating device 2101, the second heating device 2102, and the fixing member 3100 (FIG. 1), and to suppress the occurrence of transport failure.

[0073] The first heating device 2101 and the second heating device 2102 can have the same configuration as the above-mentioned heating device 2100. The temperatures of the first heating device 2101 and the second heating device 2102 and the wind speed when blowing heated gas for heating may be the same or different. Furthermore, heating may be performed from the first conveying member 2201 and the second conveying member 2202 as necessary.

[0074] [Fixing section] As shown in FIG. 1, the fixing unit 3000 is a contact-type heating and pressurizing mechanism having a fixing member 3100 as a fixing belt such as an endless belt and a conveying member 3200. In the fixing unit 3000, the recording medium 1100 is conveyed by the conveying member 3200, and the fixing member 3100 is brought into contact with the recording medium 1100 under pressure, and the liquid such as the reaction liquid or ink applied to the recording medium 1100 is heated. In this way, an image can be fixed on the recording medium 1100. From the recording medium 1100 on which an image has been recorded, the liquid components of the reaction liquid or ink permeate the recording medium 1100 or evaporate by passing through the heating unit 2000, and then the image is fixed in the fixing unit 3000, completing the image. By heating and pressurizing the recording medium 1100 sandwiched between the fixing member 3100 and the conveying member 3200, the image of the recording medium 1100 and the fixing member 3100 come into close contact with each other, and the image is fixed on the recording medium 1100. When a liquid such as ink containing resin particles and coloring material is used, the resin particles are softened and form a film mainly by heating in the fixing unit 3000 , and the coloring material can be bound onto the recording medium 1100 .

[0075] The fixing member 3100 may be heated by providing a heat source such as a halogen heater inside a roller that drives the fixing member 3100 as a fixing belt. Alternatively, a heat source such as an infrared heater may be provided at a location separate from the fixing member 3100. These methods may be combined. If necessary, the conveying member 3200 may be heated. The temperature of the fixing member 3100 may be set so that the surface of the recording medium has a desired temperature, taking into account the conveying speed and the environmental temperature. Specifically, the temperature of the fixing member 3100 is preferably 50° C. or higher and 120° C. or lower, and more preferably 60° C. or higher and 110° C. or lower. The temperature of the contact-type heating and pressing mechanism (fixing member 3100) and the surface temperature of the recording medium immediately after passing through the contact-type heating and pressing mechanism can both be measured using a radiation thermometer. The radiation thermometer may be installed near the end (terminal end) of the contact-type heating and pressing mechanism. A specific example of the radiation thermometer is a product name "Radiation Thermometer IT-545S" (manufactured by Horiba, Ltd.).

[0076] When the ink contains resin particles, if the temperature of the fixing member 3100 is set to a temperature equal to or higher than the glass transition temperature of the resin particles in the ink, the resin particles soften and are more likely to form a film, improving the scratch resistance of the image. When the ink contains wax particles, it is preferable to set the temperature of the fixing member 3100 lower than the melting point of the wax that constitutes the wax particles. This makes it easier for the wax, which is prevented from melting, to remain on the surface of the image, improving the scratch resistance of the image.

[0077] The nip pressure of the fixing member 3100 and the conveying member 3200, i.e., the pressure applied to the recording medium when it passes through the contact-type heating and pressing mechanism, is preferably from 10 Pa to 1,000 Pa, and more preferably from 10 Pa to 500 Pa. Also, it is particularly preferably from 10 Pa to 400 Pa. The time required for the recording medium to pass through the contact-type heating and pressing mechanism (nip time) is preferably from 0.25 seconds to 5.0 seconds, more preferably from 0.5 seconds to 4.0 seconds, and particularly preferably from 1.0 seconds to 3.0 seconds.

[0078] FIG. 13 is a schematic diagram showing another example of the fixing unit. Here, the difference from the fixing unit shown in FIG. 1 and described above will be described. The fixing unit 3000 shown in FIG. 13 is a contact type heating and pressurizing mechanism including a plurality of fixing rollers 3101 and a plurality of conveying members 3201 arranged opposite to these fixing rollers 3101. An image is fixed on the recording medium 1100 to which a liquid such as ink has been applied by passing between the fixing rollers 3101 and the conveying members 3201. The degree of image fixing on the recording medium can be adjusted by controlling the number of fixing rollers 3101 and the conveying members 3201, the nip time of the recording medium by these, the temperature, the pressure, and the like.

[0079] [Cooling section] The cooling section 4000 is configured to include a cooling member 4100 and a conveying member 4200 (FIG. 1). The cooling section 4000 cools the recording medium 1100, which has been heated to a high temperature after passing through the heating section 2000 and the fixing section 3000. The cooling member 4100 may have any configuration as long as it can cool the recording medium 1100, and methods such as air cooling and water cooling can be used. Among them, blowing unheated gas is preferable in terms of safety and energy efficiency. In addition, if a fan is built in to inject gas onto the recording medium 1100 and a mechanism for blowing air is used, it is easy to improve cooling efficiency. The temperature of the cooling means can be set so that the image on the recording medium has a desired temperature, taking into account the conveying speed and the environmental temperature. Specifically, the temperature of the cooling means (such as air blowing) is preferably 20° C. or higher and 60° C. or lower, and more preferably 25° C. or higher and 50° C. or lower. When cooling by blowing gas, the wind speed is preferably 1 m / s or higher and 100 m / s or lower. By setting such conditions, it is possible to suppress deformation of the recording medium 1100 loaded in the paper discharge unit 6000 described later and image sticking (blocking).

[0080] [Inverted part] When performing double-sided recording, the recording medium 1100 is inverted using the inversion unit 5000 (FIG. 1). The recording medium 1100 with an image recorded on its recording surface (front side) passes through the cooling unit 4000, is branched and transported, and is inverted by the inversion device 5100. The inverted recording medium 1100 is transported to the paper feeder 1400 of the recording unit 1000 with liquid applied to its back side (the side opposite to the recording surface (front side)).

[0081] [Paper output section] After the image is recorded, the recording medium 1100 is stored in a paper discharge section 6000 (FIG. 1). After single-sided or double-sided recording is performed, the recording medium 1100 passes through the cooling section 4000, is transported by a transport member 6100, and is finally stored in a stacked state in a recording medium storage section 6200. Two or more recording medium storage sections 6200 may be provided to store different recorded materials, etc.

[0082] <Maintenance fluid> The maintenance liquid used in the recording method and recording apparatus of the present invention is an aqueous maintenance liquid. Each component of the maintenance liquid will be described in detail below.

[0083] (aqueous medium) The maintenance liquid is an aqueous maintenance liquid containing at least water as an aqueous medium. The maintenance liquid may contain water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent. As the water, deionized water or ion-exchanged water is preferably used. The water content (mass%) in the maintenance liquid is preferably 50.0 mass% or more, more preferably 80.0 mass% or more, based on the total mass of the maintenance liquid. The water content (mass%) in the maintenance liquid is preferably 99.0 mass% or less, more preferably 98.5 mass% or less, based on the total mass of the maintenance liquid. If the water content in the maintenance liquid is high, the maintenance liquid is likely to dissolve thickened matter and precipitates when applied to the discharge port surface of the reaction liquid, and therefore the thickened matter and precipitates are easily removed by wiping operation, improving cleaning properties.

[0084] Examples of water-soluble organic solvents that can be used in the maintenance liquid include alcohols, (poly)alkylene glycols, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds. Of these, it is preferable to use low-polarity solvents such as polyhydric alcohols and glycol ethers. The content (mass %) of the water-soluble organic solvent in the maintenance liquid is preferably 50.0 mass % or less, and more preferably 20.0 mass % or less, based on the total mass of the maintenance liquid. The content of the water-soluble organic solvent in the maintenance liquid is preferably 1.0 mass % or more, and more preferably 1.5 mass % or more.

[0085] The relative dielectric constant of the aqueous medium of the maintenance liquid at 25°C is preferably 65 or more. The method of calculating the relative dielectric constant is as described later in the description of the reaction liquid. If the aqueous medium of the maintenance liquid has a relative dielectric constant of 65 or more, the maintenance liquid is likely to dissolve thickened substances and precipitates when applied to the discharge port surface of the second liquid application device that discharges the reaction liquid, and therefore the substances are easily removed by a wiping operation, improving the cleaning properties. The relative dielectric constant of the aqueous medium of the maintenance liquid at 25°C is preferably 73.5 or less.

[0086] (Other Ingredients) The maintenance liquid may contain various other components as necessary. Examples of other components include the same additives as those that can be contained in the ink.

[0087] (Relationship between the surface tension of the reaction solution and the maintenance solution) Surface tension of reaction solution γ R (mN / m) and the surface tension of the maintenance liquid γ C The absolute value of the difference from the surface tension γ of the reaction liquid must be 15 mN / m or less, and the absolute value of the difference is preferably 5 mN / m or less. R (mN / m) and the surface tension of the maintenance liquid γ C The values ​​in mN / m are all at 25°C. The surface tension of the reaction solution γ R and the surface tension of the maintenance liquid γ C The smaller the difference between the surface tension γ of the maintenance liquid, the less the reaction liquid and the maintenance liquid move and mix on the discharge port surface of the second liquid application device that discharges the reaction liquid, and the more effectively pure maintenance liquid can be left on the discharge port surface. Therefore, the thickened matter and precipitates adhering to the discharge port surface can be efficiently dissolved with the maintenance liquid and removed by a wiping operation, restoring the discharge state of the reaction liquid to a normal state and maintaining image quality. C is the surface tension of the reaction solution γ RWithin the range satisfying that the absolute value of the difference from is 15 mN / m or less, it is preferably 20 mN / m or more and 50 mN / m or less, and more preferably 22 mN / m or more and 45 mN / m or less.

[0088] <Reaction solution> The recording method of the present invention preferably further comprises a reaction liquid application step of applying an aqueous reaction liquid containing a reactant that reacts with the aqueous ink to the recording medium prior to the ink application step. Each component used in the reaction liquid will be described in detail below.

[0089] [Reactants] The reaction liquid reacts with the ink when it comes into contact with the ink, and aggregates the components in the ink (components having anionic groups, such as resins, surfactants, and self-dispersing pigments), and contains a reactant. The presence of the reactant can destabilize the state of the components having anionic groups in the ink when the ink and the reactant come into contact with each other on the recording medium, and promote the aggregation of the ink. Examples of the reactant include cationic components such as polyvalent metal ions and cationic resins, and organic acids. The reactant may be used alone or in combination of two or more.

[0090] Examples of polyvalent metal ions constituting polyvalent metal salts include Ca. 2+ , Cu 2+ , Ni 2+ , Mg 2+ , Sr 2+ , B.A. 2+ , and Zn 2+ Divalent metal ions such as Fe 3+ , Cr 3+ , Y 3+ , and Al 3+ In order to add a polyvalent metal ion to the reaction solution, a water-soluble polyvalent metal salt (which may be a hydrate) formed by combining a polyvalent metal ion with an anion can be used. Examples of the anion include Cl. - , Br - , I - , ClO - , ClO2- , ClO3 - , ClO4 - , NO2 - , NO3 - , SO4 2- , CO3 2- , HCO3 - , PO4 3- , HPO4 2- , and H2PO4 - Inorganic anions such as HCOO - , (COO - )2, COOH(COO - ), CH3COO - , CH3CH(OH)COO - , C2H4(COO - )2, C6H5COO - , C6H4(COO - )2, and CH3SO3 - Examples of the organic anions include organic anions such as . In the case where a polyvalent metal ion is used as a reactant, the content (mass%) of the polyvalent metal salt in the reaction solution is preferably 1.0 mass% or more and 35.0 mass% or less, and more preferably 1.0 mass% or more and 20.0 mass% or less, based on the total mass of the reaction solution. In this specification, when the polyvalent metal salt is a hydrate, the "content (mass%) of the polyvalent metal salt" in the reaction solution means the "content (mass%) of the anhydride of the polyvalent metal salt" excluding water as the hydrate.

[0091] The reaction liquid containing an organic acid has a buffering ability in the acidic range (less than pH 7.0, preferably pH 2.0 to 5.0), and thus efficiently converts the anionic groups of the components present in the ink into an acid form and causes them to aggregate. Examples of the organic acid include monocarboxylic acids and salts thereof, such as formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, glycolic acid, lactic acid, salicylic acid, pyrrole carboxylic acid, furan carboxylic acid, picolinic acid, nicotinic acid, thiophene carboxylic acid, levulinic acid, and coumaric acid; dicarboxylic acids and salts and hydrogen salts thereof, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, itaconic acid, sebacic acid, phthalic acid, malic acid, and tartaric acid; tricarboxylic acids and salts and hydrogen salts thereof, such as citric acid and trimellitic acid; and tetracarboxylic acids and salts and hydrogen salts thereof, such as pyromellitic acid. When an organic acid is used as the reactant, the content (mass %) of the organic acid in the reaction liquid is preferably 1.0 mass % or more and 50.0 mass % or less based on the total mass of the reaction liquid.

[0092] Examples of cationic resins include resins having a structure of primary to tertiary amines and resins having a structure of quaternary ammonium salts. Specific examples include resins having a structure of vinylamine, allylamine, vinylimidazole, vinylpyridine, dimethylaminoethyl methacrylate, ethyleneimine, guanidine, diallyldimethylammonium chloride, and alkylamine-epichlorohydrin condensate. In order to increase the solubility in the reaction solution, the cationic resin may be used in combination with an acidic compound or the cationic resin may be subjected to a quaternary treatment. When a cationic resin is used as a reactant, the content (mass%) of the cationic resin in the reaction solution is preferably 0.1 mass% or more and 10.0 mass% or less based on the total mass of the reaction solution.

[0093] The reactant preferably contains a compound having a solubility of 30% by mass or less in water at 20°C. If the solubility of the reactant in water is 30% by mass or less, it is likely to precipitate when water evaporates, but the configuration of the present invention can provide a sufficient cleaning effect. Therefore, the technical significance of the present invention is further enhanced. The solubility in water (% by mass) is defined as the mass g of the compound contained in 100 g of a saturated solution at a temperature of 20°C (in the case of a hydrate, the mass is calculated based on the anhydrous compound) / 100 g x 100 (% by mass). For example, a water solubility of 1% by mass at 20°C means that the mass dissolved in 100 g of water at a temperature of 20°C is 1 g.

[0094] The reactant preferably contains at least one selected from the group consisting of polyvalent metal salts and organic acids. Polyvalent metal salts and organic acids have smaller molecular weights than cationic resins, and thickeners and precipitates are easily dissolved in the maintenance liquid, making them easier to remove by wiping, improving cleaning performance.

[0095] [Aqueous medium] The reaction liquid is an aqueous reaction liquid containing at least water as an aqueous medium. As the water, it is preferable to use deionized water or ion-exchanged water. The content (mass%) of water in the reaction liquid is preferably 40.0 mass% or more and 99.0 mass% or less, and more preferably 50.0 mass% or more and 95.0 mass% or less, based on the total mass of the reaction liquid. The content (mass%) of water in the reaction liquid is 5 times or more, and preferably 15 times or more, the content (mass%) of the reactant in the reaction liquid. By increasing the amount of water relative to the amount of the reactant, thickening and precipitation of the reactant are less likely to occur. Therefore, even if the reaction liquid is discharged for a long time, the amount of thickened matter and precipitates is small, making cleaning easier. The amount of water here also includes hydrates contained in polyvalent metal salts. The content (mass%) of water in the reaction liquid is preferably 99 times or less, and more preferably 75 times or less, the content (mass%) of the reactant.

[0096] The aqueous medium used in the reaction liquid may contain a water-soluble organic solvent, which can be contained in the ink and will be described later. The content (mass %) of the water-soluble organic solvent in the reaction liquid is preferably 50.0 mass % or less, based on the total mass of the reaction liquid, and more preferably 1.0 mass % or more and 45.0 mass % or less. The water-soluble organic solvent preferably contains a specific water-soluble hydrocarbon compound, which will be described later. The content (mass %) of the specific water-soluble hydrocarbon compound in the reaction liquid is preferably 1.0 mass % or more and 20.0 mass % or less, based on the total mass of the reaction liquid.

[0097] The relative dielectric constant of the aqueous medium of the reaction liquid at 25°C is preferably 65 or more. The relative dielectric constant of the aqueous medium of the reaction liquid at 25°C is preferably 73.5 or less. The aqueous medium refers to water and a water-soluble organic solvent. When water and a water-soluble organic solvent are contained in the reaction liquid, the entire water and the water-soluble organic solvent are regarded as the aqueous medium, and the relative dielectric constant of the aqueous medium of the reaction liquid is calculated by the so-called weighted average method. For example, in the case of a liquid containing 80.0 mass% of water with a relative dielectric constant of 73.5, 5.0 mass% of a water-soluble organic solvent with a relative dielectric constant of 40.0, and 5.0% of a water-soluble organic solvent with a relative dielectric constant of 20.0, the relative dielectric constant of the aqueous medium can be calculated by the following formula. (73.5×80.0+40.0×5.0+20.0×5.0) / (80.0+5.0+5.0) ≒ 68.7

[0098] The relative dielectric constant of water and water-soluble organic solvents can be measured using a dielectric constant meter (e.g., trade name "BI-870" manufactured by BROOKHAVEN INSTRUMENTS CORPORATION) at a temperature of 25°C and a frequency of 10 kHz. The relative dielectric constant of a water-soluble organic solvent that is solid at a temperature of 25°C is determined by measuring the relative dielectric constant of a 50% by mass aqueous solution and calculating the value from the following formula (A). Usually, "water-soluble organic solvent" means a liquid, but in the present invention, water-soluble organic solvents that are solid at 25°C (room temperature) are also included. ε sol =2ε 50% -ε water (A) ε sol: Dielectric constant of solid water-soluble organic solvent at 25℃ ε 50% : Relative dielectric constant of a 50% by mass aqueous solution of a solid water-soluble organic solvent at 25°C ε water : relative dielectric constant of water

[0099] Specific examples of water-soluble organic solvents that are solid at 25°C and are generally used in inks and reaction liquids include 1,6-hexanediol, trimethylolpropane, ethylene urea, urea, polyethylene glycol with a number average molecular weight of 1,000, sorbitol, xylitol, and trehalose. The reason for calculating the dielectric constant of a water-soluble organic solvent that is solid at 25°C from the dielectric constant of a 50% by mass aqueous solution is as follows. Among water-soluble organic solvents that are solid at 25°C and can be components of inks and reaction liquids, there are some that are difficult to prepare high-concentration aqueous solutions of more than 50% by mass. On the other hand, in low-concentration aqueous solutions of 10% by mass or less, the dielectric constant of water becomes dominant, and it is difficult to obtain a reliable (effective) value of the dielectric constant of the water-soluble organic solvent. Therefore, the present inventors conducted an investigation and found that most of the water-soluble organic solvents that are solid at 25°C used in inks and reaction liquids can be used to prepare aqueous solutions to be measured, and the calculated dielectric constant is consistent with the effects of the present invention. For the above reasons, in the present invention, the dielectric constant of a water-soluble organic solvent that is solid at 25°C is calculated from the dielectric constant of a 50% by mass aqueous solution and used. Even if the water-soluble organic solvent is solid at 25°C, if its solubility in water is low and a 50% by mass aqueous solution cannot be prepared, an aqueous solution of the saturated concentration is used, and the above ε sol For convenience, the value of the relative dielectric constant calculated in accordance with the calculation of

[0100] [Other ingredients] The reaction liquid may contain various other components as necessary. Examples of other components include the same components as those that can be contained in the ink, which will be described later. In the present invention, these components are not included in the "aqueous medium" and are not included in the calculation of the relative dielectric constant.

[0101] [Physical properties of reaction solution] The reaction liquid is an aqueous reaction liquid applied to the inkjet method. Therefore, from the viewpoint of reliability, it is preferable to appropriately control the physical property values. Specifically, the surface tension of the reaction liquid at 25°C is preferably 20 mN / m or more and 60 mN / m or less. In addition, the viscosity of the reaction liquid at 25°C is preferably 1.0 mPa·s or more and 10.0 mPa·s or less. The pH of the reaction liquid at 25°C is preferably 5.0 or more and 9.5 or less, and more preferably 6.0 or more and 9.0 or less.

[0102] Surface tension of reaction solution γ R is the surface tension of the maintenance liquid γ C Within the range satisfying that the absolute value of the difference from is 15 mN / m or less, it is preferably 20 mN / m or more and 50 mN / m or less, and more preferably 22 mN / m or more and 45 mN / m or less.

[0103] <Ink> The ink used in the recording method of the present invention is a water-based ink for ink-jet recording. Each component of the ink will be described in detail below.

[0104] [Colorant] The ink preferably contains a coloring material. Pigments or dyes can be used as the coloring material. 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 more preferably 1.0% by mass or more and 10.0% by mass or less, based on the total mass of the ink.

[0105] Specific examples of pigments include inorganic pigments such as carbon black and titanium oxide, and organic pigments such as azo, phthalocyanine, quinacridone, isoindolinone, imidazolone, diketopyrrolopyrrole, dioxazine, etc. The pigments may be used alone or in combination of two or more.

[0106] As the pigment dispersion method, resin-dispersed pigments using resin as a dispersant, self-dispersed pigments in which hydrophilic groups are bonded to the pigment particle surface, etc. can be used. In addition, resin-bonded pigments in which organic groups containing resin are chemically bonded to the pigment particle surface, and microencapsulated pigments in which the pigment particle surface is coated with resin, etc. can be used. It is also possible to use a combination of these pigments with different dispersion methods.

[0107] As the resin dispersant for dispersing the pigment in the aqueous medium, it is preferable to use one that can disperse the pigment in the aqueous medium by the action of anionic groups. As the resin dispersant, a resin having an anionic group can be used, and it is preferable to use a resin as described below, especially a water-soluble resin. The content (mass%) of the pigment in the ink is preferably 0.3 times or more and 10.0 times or less in mass ratio to the content (mass%) of the resin dispersant.

[0108] As the self-dispersing pigment, an anionic group such as a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group can be used, which is bonded to the particle surface of the pigment directly or via another atomic group (-R-). The anionic group may be either an acid type or a salt type, and when it is a salt type, it may be either a partially dissociated state or a completely dissociated state. When the anionic group is a salt type, examples of the cation that serves as the counter ion include an alkali metal cation, ammonium, and organic ammonium. Specific examples of the other atomic group (-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; an ester group; and an ether group. In addition, it may be a group that is a combination of these groups.

[0109] The dye preferably has an anionic group. Specific examples of the dye include azo, triphenylmethane, (aza)phthalocyanine, xanthene, and anthrapyridone dyes. The dye may be used alone or in combination of two or more. The coloring material is preferably a pigment, and more preferably a resin-dispersed pigment or a self-dispersed pigment.

[0110] [resin] The ink can contain a resin. By using an ink containing a resin, an image with improved abrasion resistance can be recorded. The resin can be added to the ink (i) to stabilize the dispersion state of the pigment, that is, as a resin dispersant or its auxiliary, or (ii) to improve various properties of the recorded image.

[0111] The content (mass %) of the resin in the ink is preferably 0.1% by mass or more and 20.0% by mass or less, more preferably 0.5% by mass or more and 15.0% by mass or less, based on the total mass of the ink. 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 that are dispersed in an aqueous medium. The resin may be used alone or in combination of two or more kinds.

[0112] [Resin Composition] Examples of the resin include acrylic resins, urethane resins, olefin resins, etc. Among them, acrylic resins and urethane resins are preferred, and acrylic resins composed of units derived from (meth)acrylic acid or (meth)acrylate are more preferred.

[0113] The acrylic resin preferably has a hydrophilic unit and a hydrophobic unit as constituent units. Among them, 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 monomer is preferred. In particular, a resin having a hydrophilic unit derived from (meth)acrylic acid and a hydrophobic unit derived from at least one of styrene and α-methylstyrene is preferred. These resins are easily interacted with pigments, and therefore can be suitably used as a resin dispersant for dispersing pigments.

[0114] 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 acidic monomers having a carboxylic acid group such as (meth)acrylic acid, itaconic acid, maleic acid, and fumaric acid, and anionic monomers such as anhydrides and salts of these acidic monomers. Examples of cations constituting the salts of acidic monomers include ions of lithium, sodium, potassium, ammonium, and organic ammonium. The hydrophobic unit is a unit not having a hydrophilic group such as an anionic group. The hydrophobic unit can be formed, for example, by polymerizing a hydrophobic monomer not having a 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; and (meth)acrylic acid ester monomers such as methyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.

[0115] The urethane resin can be obtained by reacting, for example, polyisocyanate with a polyol. In addition, a chain extender may be further reacted with the urethane resin. Examples of the olefin resin include polyethylene and polypropylene.

[0116] [Resin properties] In this specification, "a resin is water-soluble" means that when the resin is neutralized with an alkali equivalent to the acid value, the resin is present in an aqueous medium in a state in which it does not form particles whose particle size can be measured by a dynamic light scattering method. Whether or not a resin is water-soluble can be determined according to the following method. First, a liquid (resin solid content: 10 mass%) containing a resin neutralized with an alkali (sodium hydroxide, potassium hydroxide, etc.) equivalent to the acid value is prepared. Next, the prepared liquid is diluted 10 times (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 a dynamic light scattering method, if no particles having a particle size are measured, the resin can be determined to be water-soluble. The measurement conditions at this time can be, for example, SetZero: 30 seconds, number of measurements: 3 times, and measurement time: 180 seconds. In addition, a particle size analyzer using a dynamic light scattering method (for example, the product name "UPA-EX150", manufactured by Nikkiso) can be used as a particle size distribution measuring device. Of course, the particle size distribution measuring device and the measurement conditions are not limited to those described above.

[0117] The acid value of the water-soluble resin is preferably 100 mgKOH / g or more and 250 mgKOH / g or less, and the weight average molecular weight of the water-soluble resin is preferably 3,000 or more and 15,000 or less.

[0118] 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 resin constituting the resin particles is preferably 1,000 or more and 3,000,000 or less, more preferably 100,000 or more and 3,000,000 or less. The volume-based cumulative 50% particle diameter (D50) of the resin particles measured by dynamic light scattering is preferably 50 nm or more and 500 nm or less. The volume-based cumulative 50% particle diameter of the resin particles is the diameter of the particles that is 50% of the total volume of the measured particles when integrated from the small particle diameter side in the particle diameter integration curve. The volume-based cumulative 50% particle diameter of the resin particles can be measured using the dynamic light scattering particle size analyzer and measurement conditions described above. The glass transition temperature of the resin particles is preferably 40°C or more and 120°C or less, more preferably 50°C or more and 100°C or less. The glass transition temperature (° C.) of the resin particles can be measured using a differential scanning calorimeter (DSC). The resin particles do not necessarily contain a coloring material.

[0119] [Wax particles] The ink may contain particles formed of wax (wax particles). By using an ink containing wax particles, an image with improved abrasion resistance can be recorded. In this specification, the wax may be a composition containing components other than wax, or the wax itself. The wax particles may be dispersed by a dispersant such as a surfactant or a resin. The wax may be used alone or in combination of two or more kinds. The content (mass %) of the wax particles in the ink is preferably 0.1 mass % or more and 10.0 mass % or less, and more preferably 1.0 mass % or more and 5.0 mass % or less, based on the total mass of the ink.

[0120] In the narrow sense, wax is an ester of a water-insoluble higher monohydric or dihydric alcohol and a fatty acid, and includes animal waxes and vegetable waxes, but does not include oils and fats. In the broad sense, wax includes high melting point fats, mineral waxes, petroleum waxes, and blends and modified products of various waxes. In the present invention, any wax in the broad sense can be used without particular restrictions. Wax in the broad sense can be classified into natural waxes, synthetic waxes, blends thereof (blended waxes), and modified products thereof (modified waxes).

[0121] Examples of natural waxes include animal waxes such as beeswax, spermaceti, and wool wax (lanolin); vegetable waxes such as wood wax, carnauba wax, sugarcane wax, palm wax, candelilla wax, and rice wax; mineral waxes such as montan wax; and petroleum waxes such as paraffin wax, microcrystalline wax, and petrolatum. Examples of synthetic waxes include hydrocarbon waxes such as Fischer-Tropsch wax and polyolefin wax (e.g., polyethylene wax and polypropylene wax). The blended wax is a mixture of the above-mentioned various waxes. The modified wax is a wax obtained by subjecting the above-mentioned various waxes to a modification treatment such as oxidation, hydrogenation, alcohol modification, acrylic modification, and urethane modification. One of the above waxes may be used alone, or two or more may be used in combination. The wax is preferably at least one selected from the group consisting of microcrystalline wax, Fischer-Tropsch wax, polyolefin wax, paraffin wax, and modified or blended products thereof. Among them, a blend of multiple types of wax is more preferable, and a blend of a petroleum wax and a synthetic wax is particularly preferable.

[0122] The wax is preferably solid at room temperature (25°C). The melting point (°C) of the wax is preferably 40°C or higher and 120°C or lower, and more preferably 50°C or higher and 100°C or lower. The melting point of the wax can be measured in accordance with the test method described in 5.3.1 (melting point test method) of JIS K2235:1991 (petroleum wax). In the case of microcrystalline wax, petrolatum, and a mixture of multiple types of wax, the test method described in 5.3.2 can be used to measure more accurately. The melting point of the wax is easily affected by characteristics such as molecular weight (the higher the molecular weight, the higher the melting point), molecular structure (the higher the melting point if the chain is straight, and the lower the melting point if there is branching), crystallinity (the higher the crystallinity, the higher the melting point), and density (the higher the crystallinity, the higher the melting point). Therefore, by controlling these characteristics, it is possible to obtain a wax having a desired melting point. The melting point of the wax in the ink can be measured in accordance with the above test method, for example, after the ink is subjected to ultracentrifugation, the wax separated is washed and dried.

[0123] [Aqueous medium] The ink used in the recording method of the present invention is an aqueous ink containing at least water as an aqueous medium. The ink can contain water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent. As the water, deionized water or ion-exchanged water is preferably used. The content (mass%) of water in the aqueous ink is preferably 50.0% by mass or more and 95.0% by mass or less based on the total mass of the ink. In addition, the content (mass%) of the water-soluble organic solvent in the aqueous ink is preferably 2.0% by mass or more and 40.0% by mass or less based on the total mass of the ink. As the water-soluble organic solvent, any of those usable for inkjet inks, such as alcohols, (poly)alkylene glycols, glycol ethers, nitrogen-containing solvents, and sulfur-containing solvents, can be used. Examples of the water-soluble organic solvent include alkanediols such as 1,2-propanediol (also known as propylene glycol), 1,2-butanediol, 1,2-hexanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, and 1,6-hexanediol; amino acids such as β-alanine and trimethylglycine; sulfonyl compounds such as bis(2-hydroxyethyl)sulfone; alkylene glycols such as triethylene glycol, tetraethylene glycol, tripropylene glycol, and polyethylene glycol having a number average molecular weight of about 200 to 1,000; and sugars such as sorbitol. The water-soluble organic solvent may be used alone or in combination of two or more.

[0124] [Water-soluble hydrocarbon compounds] The water-soluble organic solvent contained in the ink may contain a specific water-soluble hydrocarbon compound. This water-soluble hydrocarbon compound is a compound having a hydrocarbon chain with three or more carbon atoms substituted with two or more hydrophilic groups selected from the group consisting of hydroxyl groups, amino groups, and anionic groups. However, the hydrocarbon chain may be interrupted by a sulfonyl group or an ether group. When the hydrocarbon chain has three or four carbon atoms, the hydrophilic group contains an anionic group, or the hydrocarbon chain is interrupted by a sulfonyl group.

[0125] In the present invention, a hydrocarbon compound that is dissolved in water at 25°C at the content of the compound in the ink is considered to be "water-soluble". In other words, the solubility in water at 25°C is greater than the content in the ink. The fact that the hydrocarbon chain is interrupted by a sulfonyl group or an ether group means that a sulfonyl group (-S(=O)2-) or an ether group (-O-) is present in the middle of the hydrocarbon chain. Water-soluble hydrocarbon compounds have hydrogen-bonding groups such as hydroxyl groups, amino groups, anionic groups, sulfonyl groups, and ether groups. Therefore, by using an ink containing this hydrocarbon compound, cockling and curling of a recording medium on which an image is recorded can be suppressed. General hydrocarbon compounds having a hydrocarbon chain with a relatively small number of carbon atoms (3 or 4) tend to have a small molecular weight and a low vapor pressure. However, since the above water-soluble hydrocarbon compounds have anionic groups of hydrogen bonds or the hydrocarbon chain is interrupted by a sulfonyl group, they are difficult to evaporate due to inter- or intra-molecular interactions, and remain between fibers to suppress cockling and curling. The content (mass %) of the water-soluble hydrocarbon compound in the ink is preferably 1.0 mass % or more and 20.0 mass % or less based on the total mass of the ink.

[0126] The number of carbon atoms in the hydrocarbon chain constituting the water-soluble hydrocarbon compound is preferably from 3 to 50, and more preferably from 3 to 10. Examples of the anionic group include a sulfonic acid group and a carboxylic acid group. Specific examples of water-soluble hydrocarbon compounds include alkanediols such as 1,5-pentanediol and 1,6-hexanediol; amino acids such as alanine, β-alanine, trimethylglycine, amidosulfuric acid (also known as sulfamic acid), aminomethanesulfonic acid, taurine (also known as 2-aminoethanesulfonic acid), carbamic acid, glycine, aspartic acid, glutamic acid, sulfanilic acid, or salts of the above-mentioned acids, phenylalanine, leucine, isoleucine, threonine, tryptophan, valine, methionine, lysine, and arginine; sulfonyl compounds such as bis(2-hydroxyethyl)sulfone; alkylene glycols such as triethylene glycol, tetraethylene glycol, tripropylene glycol, and polyethylene glycols having a number average molecular weight of about 200 to 1,000; and sugars such as sorbitol, D-sorbitol, xylitol, trehalose, fructose, and D(+)-xylose. The water-soluble hydrocarbon compounds may be used alone or in combination of two or more.

[0127] [Other ingredients] The ink may contain various other components as necessary. Examples of other components include various additives such as defoamers, surfactants, pH adjusters, viscosity adjusters, rust inhibitors, preservatives, antifungal agents, antioxidants, and reduction inhibitors. However, it is preferable that the ink does not contain a reactant to be contained in the reaction liquid.

[0128] [Ink properties] The ink is a water-based ink applied to the inkjet method. Therefore, from the viewpoint of reliability, it is preferable to appropriately control the physical property values. Specifically, the surface tension of the ink at 25°C is preferably 20 mN / m or more and 60 mN / m or less. In addition, the viscosity of the ink at 25°C is preferably 1.0 mPa·s or more and 10.0 mPa·s or less. The pH of the ink at 25°C is preferably 7.0 or more and 9.5 or less, and more preferably 8.0 or more and 9.5 or less. EXAMPLES

[0129] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples without departing from the gist of the present invention. "Parts" and "%" used to describe the amounts of components are based on mass unless otherwise specified.

[0130] <Preparation of reaction solution> Each component (unit: %) shown in Table 1 (Tables 1-1 to 1-3) was mixed and thoroughly stirred, and then pressure filtered with a cellulose acetate filter (manufactured by Advantec) with a pore size of 3.0 μm to prepare each reaction solution. "Acetylenol E100" and "Acetylenol E60" shown in Table 1 are the trade names of acetylene glycol ethylene oxide adducts, which are hydrocarbon surfactants manufactured by Kawaken Fine Chemicals (the same applies to Tables 2 and 3 described below). "BYK348" is the trade name of a silicone surfactant manufactured by BYK (the same applies to Table 3 described below). "Cationic polymer (PQ40U05NV)" is the trade name of an aqueous solution of diallyldimethylammonium chloride polymer having a quaternary ammonium salt structure manufactured by KATPOL (cationic resin content: 40%). The numbers in parentheses for the aqueous medium shown in the component column of Table 1 represent the relative dielectric constant values ​​at 25°C.

[0131] The lower part of Table 1 shows the properties of the reaction solution, such as the content (%) of water including water of hydration in the reaction solution, the relative dielectric constant of the aqueous medium at 25°C, the solubility (%) of the reactant in water at 20°C, and the ratio (times) of the water content to the reactant content. The solubility (%) of the reactant in water at 20°C was calculated by (content of reactant excluding water of hydration / total content of water and reactant) x 100 (%). The lower part of Table 1 also shows the surface tension γ of the reaction solution at 25°C. R The surface tension of the reaction solution at 25°C was measured by the platinum plate method using an automatic surface tensiometer (product name "DY-300 type", manufactured by Kyowa Interface Science Co., Ltd.) for a reaction solution prepared by mixing and stirring all of the components shown in Table 1.

[0132] TIFF2025036350000001.tif150170

[0133] TIFF2025036350000002.tif150170

[0134] TIFF2025036350000003.tif150170

[0135] <Preparation of pigment dispersion> (Pigment dispersion 1) A styrene-ethyl acrylate-acrylic acid copolymer (resin 1) with an acid value of 150 mgKOH / g and a weight average molecular weight of 8,000 was prepared. 20.0 parts of resin 1 were neutralized with potassium hydroxide in an amount equimolar to the acid value, and an appropriate amount of pure water was added to prepare an aqueous solution of resin 1 with a resin (solid content) content of 20.0%. 10.0 parts of pigment (CI Pigment Blue 15:3), 15.0 parts of the aqueous solution of resin 1, and 75.0 parts of pure water were mixed to obtain a mixture. The obtained mixture and 200 parts of zirconia beads with a diameter of 0.3 mm were placed in a batch-type vertical sand mill (manufactured by Imex) and dispersed for 5 hours while cooling with water. After removing coarse particles by centrifugation, the mixture was pressure-filtered with a cellulose acetate filter (manufactured by Advantec) with a pore size of 3.0 μm to prepare pigment dispersion 1 with a pigment content of 10.0% and a resin dispersant (resin 1) content of 3.0%.

[0136] <Preparation of resin particles> (Resin particles 1) A solution was prepared by mixing 0.2 parts of potassium persulfate and 74.0 parts of ion-exchanged water. An emulsion was prepared by mixing 24.0 parts of ethyl methacrylate (EMA), 1.5 parts of methacrylic acid (MAA), and a reactive surfactant. The reactive surfactant used was "ADEKA REASOAP ER-20" (manufactured by ADEKA, nonionic surfactant, number of moles of ethylene oxide group added: 20). The emulsion was added dropwise to the solution in a nitrogen atmosphere over 1 hour, polymerized while stirring at 80°C, and then stirred for another 2 hours. After cooling to room temperature, ion-exchanged water and an aqueous potassium hydroxide solution were added to obtain an aqueous dispersion of resin particles 1 with a resin particle content of 25.0%.

[0137] <Ink Preparation> The components (unit: %) shown in Table 2 were mixed and thoroughly stirred, and then pressure filtered using a cellulose acetate filter (manufactured by Advantec) with a pore size of 3.0 μm to prepare Ink 1.

[0138] TIFF2025036350000004.tif51170

[0139] <Preparation of maintenance liquid> The components (unit: %) shown in Table 3 (Tables 3-1 and 3-2) were mixed and thoroughly stirred, and then pressure filtered using a cellulose acetate filter (manufactured by Advantec) with a pore size of 3.0 μm to prepare each maintenance liquid. "Olfine E1010" shown in Table 3 is the product name of an acetylene glycol surfactant manufactured by Nissin Chemical Industry Co., Ltd. The lower part of Table 3 lists the properties of the maintenance liquid, such as the relative dielectric constant of the aqueous medium (including water and water-soluble organic solvents) at 25°C and the surface tension γ of the maintenance liquid. C (mN / m) was shown.

[0140] Surface tension γ of maintenance liquid Cis the surface tension of the maintenance liquid prepared by mixing and stirring all of the components shown in Table 3. This surface tension is a value measured by the platinum plate method using an automatic surface tensiometer (product name "DY-300 type", manufactured by Kyowa Interface Science).

[0141] TIFF2025036350000005.tif101170

[0142] TIFF2025036350000006.tif101170

[0143] <Cleaning conditions> The cleaning conditions are shown in Table 4 (Tables 4-1 and 4-2).

[0144] In cleaning condition 1, cleaning was performed using a cleaning unit equipped with a maintenance liquid application device 1850 shown in FIG. 8 and FIG. 9 and the like. The maintenance liquid application device 1850 shown in FIG. 8 and FIG. 9 and the like has a supply port for supplying the maintenance liquid, and is described as "tube supply" as described in Table 4. The material of the "wiper blade" equipped in the liquid removal device 1860 (first cleaning device) is urethane resin and has a thickness of 0.5 mm. The material of the "suction wiper" as the flexible member 1871 of the negative pressure application device 1870 (second cleaning device) is urethane resin. Note that in Comparative Example 2 described later, no maintenance liquid was used, and therefore no maintenance liquid was applied to the discharge port surface of the reaction liquid, and cleaning was performed under cleaning condition 1.

[0145] In cleaning condition 2, the first cleaning device, the wiper blade, was removed from the cleaning unit, and cleaning was performed using nonwoven fabric instead. The cleaning was performed under the same conditions as cleaning condition 1. The nonwoven fabric was cupra (density 0.01 g / cm 3 , cloth thickness 4.0 mm) was used.

[0146] In cleaning condition 3, cleaning was performed under the same conditions as cleaning condition 1, except that the cleaning order in cleaning condition 1 was changed.

[0147] In cleaning condition 4, cleaning was performed under the same conditions as cleaning condition 1, except that the suction wiper as the second cleaning device was removed from the cleaning unit and cleaning was performed using a wiper blade instead. The wiper blade used as the second cleaning device was the same as the wiper blade of the first cleaning device.

[0148] In cleaning condition 5, cleaning was performed under the same conditions as cleaning condition 1, except that the second cleaning device, the suction wiper, was removed from the cleaning unit.

[0149] In cleaning condition 6, the maintenance liquid application device and the second cleaning device were removed from the cleaning unit. Instead, cleaning was performed under the same conditions as cleaning condition 1, except that the maintenance liquid was applied to the wiper blade (the first cleaning device) and then applied to the ejection port surface, thereby simultaneously applying the maintenance liquid and cleaning.

[0150] In cleaning condition 7, cleaning was performed under the same conditions as cleaning condition 1, except that the tube-supplied maintenance liquid applicator was removed from the cleaning unit and instead, the maintenance liquid was applied by a roller.

[0151] In cleaning condition 8, the maintenance liquid application device and the wiper blade, which is the first cleaning device, were removed from the cleaning unit. Instead, the maintenance liquid was applied to a nonwoven fabric and applied to the discharge port surface, thereby simultaneously applying the maintenance liquid and cleaning. Cleaning was performed under the same conditions as cleaning condition 1. Cupra (density 0.01 g / cm) was used as the nonwoven fabric. 3 , cloth thickness 4.0 mm) was used.

[0152] In cleaning condition 9, the wiper blade as the first cleaning device and the suction wiper as the second cleaning device were removed from the cleaning unit, and cleaning was performed by only applying the maintenance liquid to the discharge port surface of the reaction liquid.

[0153] The maintenance liquid deposition device, the first cleaning device, and the second cleaning device each have a width that can cover the reaction liquid and the ejection port arrays of each ink collectively in a direction intersecting the direction in which the multiple ejection port arrays of the ejection element substrate are arranged. The bottom row of Table 4 shows the order in which the maintenance liquid deposition device, the first cleaning device, and the second cleaning device are operated.

[0154] TIFF2025036350000007.tif42170

[0155] TIFF2025036350000008.tif45170

[0156] <Evaluation> The recording conditions are shown in Table 5. The reaction liquid, ink, maintenance liquid, cleaning conditions, and recording conditions were combined as shown on the left side of Table 6, and an inkjet recording apparatus 100 having the configuration shown in FIG. 1 was used to record an image on a recording medium. A line head was used as the reaction liquid deposition device, and a serial head was used only in Example 13. The left side of Table 6 shows the surface tension γ of the maintenance liquid for each combination of the maintenance liquid and reaction liquid used. C - Surface tension of the reaction solution γ R The values ​​(mN / m) are also shown.

[0157] Using the inkjet recording apparatus 100 described above, the reaction liquid and the ink were applied in this order to a recording medium under the recording conditions shown in Table 5, and a solid image of 15 cm x 15 cm was recorded. In the inkjet recording apparatus 100 used in this embodiment, an image recorded under conditions in which one ink droplet of 3.0 ng is applied to a unit area of ​​1 / 1200 inch x 1 / 1200 inch is defined as having a recording duty of 100%. The recording medium was a PET film (trade name "PETWH100 PAT1 8LKY" manufactured by Lintec, 30 msec from the start of contact in the Bristow method). 1 / 2 Water absorption up to: 2.5mL / m 2 (Less than 30msec from the start of contact in the Bristow method) and art paper (Lintec's product name "Art E 8K Blue" 1 / 2 Water absorption up to: 5.3mL / m 2 ) was used.

[0158] After that, only the reaction liquid was discharged continuously for 5 hours at 100% duty, and the discharge port surface of the reaction liquid was cleaned under the cleaning conditions shown in Table 4 using a cleaning mechanism with the configuration shown in FIG. 5. After cleaning, the reaction liquid and ink were applied to the recording medium in this order under the recording conditions shown in Table 5, as in the case before the continuous discharge, to record a solid image of 15 cm x 15 cm, and the solid uniformity was evaluated. The recording medium used in this case was also a PET film (trade name "PETWH100 PAT1 8LKY" manufactured by Lintec) and art paper (trade name "Art E 8K Blue" manufactured by Lintec). The recorded image was evaluated as follows. In this embodiment, the evaluation criteria for each item below were "AAA", "AA", "A" and "B" as acceptable levels, and "C" as unacceptable levels. The evaluation results are shown on the right side of Table 6.

[0159] (Solid uniformity) Only the reaction liquid was discharged continuously for 5 hours at 100% duty, and the discharge port surface of the reaction liquid was cleaned under the cleaning conditions shown in Table 4. The recorded matter was then left for 24 hours under conditions of 23°C temperature and 50% relative humidity. After that, an image of the recorded matter was captured using a scanner (manufactured by EPSON, product name "OFFIRIOES-10000G") under the conditions of mode: professional, resolution: 300 dpi, and color: 24 bit. In order to evaluate the uniformity of the captured image, a range of 150px x 150px was converted to grayscale using Photoshop (product name made by Adobe), and the standard deviation obtained from the histogram was obtained. This was then measured at five different points on the image of the recorded matter. The solid uniformity was evaluated according to the evaluation criteria shown below using the average value of the standard deviation obtained from each measurement part. Before the reaction liquid was discharged continuously for 5 hours, a recorded matter was produced under the conditions of Table 5, and the solid uniformity was evaluated in the same manner as above, and it was confirmed that the standard deviation was less than 2.5. However, in Comparative Example 1 in which no reaction liquid was used, the standard deviation was 4.0 or more, and no image was obtained. AAA: The standard deviation was less than 2.5. AA: The standard deviation was 2.5 or more and less than 3.0. A: The standard deviation was greater than or equal to 3.0 and less than 3.5. B: The standard deviation was 3.5 or greater and less than 4.0. C: The standard deviation was 4.0 or more.

[0160] TIFF2025036350000009.tif43170

[0161] TIFF2025036350000010.tif241170

Claims

1. An inkjet recording method for recording an image on a recording medium using an inkjet recording apparatus, comprising: the inkjet recording apparatus comprises a first liquid application device having an ejection port for ejecting an aqueous ink, a second liquid application device having an ejection port for ejecting an aqueous reactive liquid containing a reactant that reacts with the aqueous ink, a maintenance liquid application device that applies an aqueous maintenance liquid to an ejection port surface on which the ejection ports of the second liquid application device are formed, and a first cleaning device that is pressed against the ejection port surface of the second liquid application device to clean the ejection port surface, The surface tension γ of the reaction liquid Ｒ (mN / m), and the surface tension γ of the maintenance liquid Ｃ (mN / m) is 15 mN / m or less, The inkjet recording method according to claim 1, wherein the content (mass %) of water in the reaction liquid is 5 times or more the content (mass %) of the reactant.

2. 2. The ink jet recording method according to claim 1, wherein the first cleaning device has a wiper blade made of a flexible material.

3. The inkjet recording method according to claim 1 , wherein after the maintenance liquid is applied to the ejection orifice surface, the ejection orifice surface of the second liquid application device is cleaned by the first cleaning device.

4. 2. The inkjet recording method according to claim 1, further comprising a second cleaning device that is pressed against the ejection port surface of the second liquid deposition device to clean the ejection port surface.

5. 5. The ink jet recording method according to claim 4, wherein the second cleaning device has a flexible member and is configured so that a negative pressure can be applied thereto.

6. 5. The inkjet recording method according to claim 4, wherein after the maintenance liquid is applied to the ejection port surface of the second liquid application device, cleaning of the ejection port surface of the second liquid application device is performed by the second cleaning device following cleaning by the first cleaning device.

7. The inkjet recording method according to claim 1 , wherein the maintenance liquid applying device includes a supply port for applying the maintenance liquid.

8. The inkjet recording method according to claim 1 , wherein the second liquid application device has a line head.

9. The surface tension γ of the reaction liquid Ｒ (mN / m), and the surface tension γ of the maintenance liquid Ｃ 2. The ink-jet recording method according to claim 1, wherein the absolute value of the difference from (mN / m) is 5 mN / m or less.

10. 2. The ink jet recording method according to claim 1, wherein the aqueous medium of the maintenance liquid has a relative dielectric constant of 65 or more at 25[deg.] C.

11. 2. The ink-jet recording method according to claim 1, wherein the aqueous medium of the reaction liquid has a relative dielectric constant of 65 or more at 25[deg.] C.

12. The ink jet recording method according to claim 1, wherein the reactant comprises at least one selected from the group consisting of polyvalent metal salts and organic acids.

13. The inkjet recording method according to claim 1 , wherein the reactant contains a compound having a solubility in water at 20° C. of 30% by mass or less.

14. a first liquid application device having an ejection port for ejecting a water-based ink; a second liquid application device including a discharge port for discharging an aqueous reactive liquid containing a reactant that reacts with the aqueous ink; a maintenance liquid applying device that applies an aqueous maintenance liquid to a discharge port surface on which the discharge ports of the second liquid applying device are formed; and a first cleaning device that is pressed against the ejection port surface of the second liquid deposition device to clean the ejection port surface, The surface tension γ of the reaction liquid Ｒ (mN / m), and the surface tension γ of the maintenance liquid Ｃ (mN / m) is 15 mN / m or less, The inkjet recording apparatus according to claim 1, wherein the content (mass %) of water in the reaction liquid is 5 times or more the content (mass %) of the reactant.

15. the reactive liquid and the maintenance liquid are used in an inkjet recording apparatus including a first liquid application device having an ejection port for ejecting an aqueous ink, a second liquid application device having an ejection port for ejecting an aqueous reactive liquid containing a reactant that reacts with the aqueous ink, a maintenance liquid application device that applies an aqueous maintenance liquid to an ejection port surface on which the ejection ports of the second liquid application device are formed, and a first cleaning device that is pressed against the ejection port surface of the second liquid application device to clean the ejection port surface, The surface tension γ of the reaction liquid Ｒ (mN / m), and the surface tension γ of the maintenance liquid Ｃ (mN / m) is 15 mN / m or less, A set of a reaction liquid and a maintenance liquid, wherein the content (mass %) of water in the reaction liquid is 5 times or more the content (mass %) of the reactant.

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