Recording apparatus and recording method

Abstract

The present invention provides a recording apparatus and a recording method, and the recording apparatus has a recording mode with excellent recording speed and image quality. The recording apparatus includes a white inkjet head, a non-white inkjet head, and a control unit. The control unit performs control for executing recording by performing multiple main scans. In the main scan, while moving the relative position of the inkjet head with respect to the recording medium, ink compositions are ejected from the inkjet head and adhered to the recording medium. The control unit executes: recording based on a first recording mode, in which, in the same main scan, the white ink composition and the non-white ink composition are adhered to the same scan area of the recording medium; and recording based on a second recording mode, in which, in different main scans, the white ink composition and the non-white ink composition are adhered to the same scan area of the recording medium.

Description

Technical Field

[0001] The present invention relates to a recording apparatus and a recording method. Background Art

[0002] An inkjet recording method can record high-precision images with a relatively simple apparatus and has been rapidly developed in various aspects. Among them, various studies have been conducted on improving image quality and the like. For example, in Patent Document 1, for the purpose of providing an image recording method capable of obtaining a high-quality image with suppressed bleeding, an image recording method is disclosed, which is characterized by having: a first step of recording a base layer on a substrate using an ink composition for forming a base layer; and a second step of recording a color image layer on the base layer in a state where the residual amount of volatile components in the base layer is 5 to 50% by mass using a process color ink composition.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010-158884

[0004] As described in Patent Document 1, by recording a base layer and then recording a color image layer, there is an advantage that a recording object with good visual recognition of a color image can be obtained. On the other hand, in the method of laminating a base layer and a color image layer in the above manner, there are problems that the recording speed of a part required for the lamination deteriorates and a large head is required. In addition, when excellent in terms of not requiring a large head and recording speed, there is a problem that excellent image quality cannot be obtained. Summary of the Invention

[0005] The present invention is a recording apparatus that performs recording on a recording medium, including: a white inkjet head that ejects a white ink composition containing a white pigment and adheres it to the recording medium; a non-white inkjet head that ejects a non-white ink composition containing a non-white pigment and adheres it to the recording medium; and a control unit that performs control for executing recording by performing a plurality of main scans, where the main scan refers to a scan in which while moving the relative position of the inkjet head with respect to the recording medium, an ink composition is ejected from the inkjet head and adheres to the recording medium, and the control unit executes: recording based on a first recording mode, where the first recording mode refers to forming a layer containing the white ink composition and the non-white ink composition by causing the white ink composition and the non-white ink composition to adhere to the same scan area of the recording medium through the same main scan; and recording based on a second recording mode, where the second recording mode refers to laminating and forming a layer containing the white ink composition and a layer containing the non-white ink composition by causing the white ink composition and the non-white ink composition to adhere to the same scan area of the recording medium through different main scans.

[0006] The present invention is a recording method. Using the above inkjet recording apparatus, either the first recording mode or the second recording mode is selected, and recording is performed through the selected recording mode. Description of the Drawings

[0007] Figure 1 An example of the recording apparatus used in the present embodiment is shown.

[0008] Figure 2 An example of the configuration of the inkjet head is shown.

[0009] Figure 3 An example of the configuration of the inkjet head is shown.

[0010] Figure 4 An example of the flowchart of the control of the recording method of the present embodiment is shown.

[0011] Figure 5 An example of the recording apparatus used in the present embodiment is shown.

[0012] Description of Reference Numerals

[0013] 1: Printer; 2: Recording head; 3: Ink cartridge; 4: Carriage; 5: Platen; 6: Heating mechanism; 7: Carriage moving mechanism; 8: Media conveying mechanism; 9: Guide bar; 10: Linear encoder; M: Recording medium; CONT: Control unit. Detailed Embodiments

[0014] Hereinafter, embodiments of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings as needed. However, the present invention is not limited thereto, and various modifications can be made without departing from the gist thereof. In the drawings, the same reference numerals are assigned to the same elements and repeated descriptions are omitted. In addition, unless otherwise specified, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Moreover, the dimensional ratios of the drawings are not limited to the ratios shown.

[0015] In addition, in the present embodiment, without particularly distinguishing between a white inkjet head and a non-white inkjet head, it is simply referred to as an "inkjet head". Similarly, without particularly distinguishing between a white ink composition and a non-white ink composition, it is simply referred to as an "ink composition".

[0016] In addition, "main scanning" refers to the following operation: while moving the relative position of the inkjet head with respect to the recording medium, an ink composition is ejected from the inkjet head and adheres to the recording medium. The inkjet head can be mounted on a carriage, for example. The inkjet head can be moved by moving the carriage, and in this case, it is the movement of the inkjet head.

[0017] In addition, the "main scanning direction" is the moving direction of the above inkjet head and refers to the width direction of the recording medium. Further, "main scanning" is the movement of the relative position of the inkjet head with respect to the recording medium, which may be the movement of the inkjet head with respect to the recording medium or the movement of the recording medium with respect to the inkjet head. The direction of this movement of the relative position is the main scanning direction. It can also be said that the movement of the relative position of the inkjet head with respect to the recording medium is the movement of the relative position of the recording medium with respect to the inkjet head. That is, it is the movement of the relative position between the inkjet head and the recording medium.

[0018] On the other hand, "sub-scanning" refers to the action of moving the relative position of the inkjet head and the recording medium in the sub-scanning direction. The "sub-scanning direction" is the direction that intersects the main scanning direction.

[0019] For example, in the main scanning, an ink composition is attached to a certain area of the recording medium, and in the sub-scanning, for example, the recording medium is slightly moved, and then the next main scanning is performed, so that the ink composition is attached adjacent to or partially overlapping with the previously attached ink composition. Recording can be performed by repeating the above actions. In addition, "sub-scanning" is also the movement of the relative position of the inkjet head with respect to the recording medium, which may be the movement of the inkjet head with respect to the recording medium or the movement of the recording medium with respect to the inkjet head. The direction of this relative movement is the sub-scanning direction.

[0020] Recording can be performed by performing multiple main scans and sub-scans respectively. For example, the main scan and the sub-scan can be alternately repeated.

[0021] 1. Recording device

[0022] The recording device of the present embodiment performs recording on a recording medium, and the recording device includes: a white inkjet head that ejects a white ink composition containing a white colorant and attaches it to the recording medium; a non-white inkjet head that ejects a non-white ink composition containing a non-white colorant and attaches it to the recording medium; and a control unit that performs control to execute recording by performing multiple main scans. The main scan refers to: while moving the relative position of the inkjet head with respect to the recording medium, ejecting an ink composition from the inkjet head and attaching it to the recording medium for scanning. The control unit executes: a first recording mode in which, through the same main scan, the white ink composition and the non-white ink composition are attached to the same scan area of the recording medium, thereby forming a layer containing the white ink composition and the non-white ink composition; and a second recording mode in which, through different main scans, the white ink composition and the non-white ink composition are attached to the same scan area of the recording medium, thereby laminating and forming a layer containing the white ink composition and a layer containing the non-white ink composition.

[0023] Conventionally, a high-quality image has been recorded by overlapping a white ink layer and a non-white ink layer and using the white ink layer as a concealment layer. However, there is a problem as follows: If the white ink layer and the non-white ink layer are formed by overlapping, the recording speed is correspondingly reduced. The present inventor has conducted research in this regard and found that: Even if the white ink layer and the non-white ink layer are not formed by overlapping as in the past, but a recording object of a single ink layer containing a white ink composition and a non-white ink composition is formed on a recording medium, an image without uneven shading and with excellent color rendering property is obtained.

[0024] Therefore, in the present embodiment, it is possible to execute: a first recording mode in which, by the same main scan, the attachment of the white ink composition and the attachment of the non-white ink composition are performed on the same scan area of the recording medium; and a second recording mode in which, by different main scans, the attachment of the white ink composition and the attachment of the non-white ink composition are performed on the same scan area of the recording medium.

[0025] That is, it is possible to execute: a first recording mode that emphasizes the recording speed and forms an image by a single ink layer containing a white ink composition and a non-white ink composition; and a second recording mode that emphasizes the image quality and forms an image by overlapping a white ink layer and a non-white ink layer as in the past. That is, it is possible to execute the recording by the first recording mode and the recording by the second recording mode.

[0026] Hereinafter, an example of a recording apparatus used in the present embodiment will be described with reference to the drawings, but the recording apparatus used in the present embodiment is not limited to the following manner.

[0027] Figure 1 An example of the recording apparatus used in the present embodiment is shown. In Figure 1 this, a carriage-mounted printer in which an ink cartridge is mounted on a carriage will be described as an example, but the recording apparatus is not limited to a carriage-mounted printer, and it may also be a carriage-unmounted printer in which the ink cartridge is fixed outside. In the case of a carriage-unmounted type, the ink cartridge 3 is installed at a place other than the carriage 4, and it is only necessary to supply ink from the ink cartridge 3 to the recording head 2 via an ink supply tube.

[0028] In addition, the printer used for the following description is a serial printer, and this serial printer mounts an inkjet head for recording on a carriage that moves in a predetermined direction, and the inkjet head moves along with the movement of the carriage to eject droplets onto the recording medium. In addition, the serial type may be a method in which main scanning is performed in a direction intersecting the sub-scanning direction that is the conveyance direction of the recording medium, or a lateral type in which the inkjet head alternately moves in the main scanning direction and the sub-scanning direction with respect to a fixed recording medium.

[0029] As Figure 1As shown in the figure, the printer 1 includes: a recording head 2, an ink cartridge 3, a carriage 4, a platen 5, a heating mechanism 6, a carriage moving mechanism 7, a medium conveying mechanism 8, guide rods 9, a linear encoder 10, and a control unit CONT.

[0030] 1.1. Inkjet head

[0031] The recording head 2 is a unit that attaches each ink composition to the recording medium M, and includes a first nozzle that ejects a white ink composition onto a surface facing the recording medium M to which each ink composition is attached, and a second nozzle that ejects a non-white ink composition. These multiple nozzles are arranged in a column shape, thereby forming a nozzle surface on the nozzle plate surface. In addition, Figure 1 in, the recording head 2 serves as both a white inkjet head and a non-white inkjet head.

[0032] As a method of ejecting a white ink composition and a non-white ink composition from the nozzles, for example, the following piezoelectric method can be cited: A pressure and a recording information signal are simultaneously applied to the white ink composition and the non-white ink composition through a piezoelectric element, and droplets of the white ink composition and the non-white ink composition are ejected and recorded. In addition, as the recording head 2, in addition to an inkjet head, a click head, a thermal transfer head, etc. can also be used.

[0033] In addition, the inkjet head of the present embodiment can be a head structure in which nozzles for ejecting a white ink composition and nozzles for ejecting a non-white ink composition are arranged horizontally, so that the attachment of the white ink composition and the attachment of the non-white ink composition to the same scanning area of the recording medium are performed by the same relative scanning. Therefore, compared with the existing head structure premised on lamination, the overall size of the inkjet head can also be reduced.

[0034] Figures 2 to 3 The nozzle formation surface of the recording head 2 is shown. The recording device of the present embodiment controls the nozzles of the recording head 2 through the control unit CONT, and can use one recording head 2 to perform both recording based on the first recording mode and recording based on the second recording mode.

[0035] Use Figure 2 to illustrate the nozzle control of the recording head 2 when performing the first recording mode. In Figure 2 the inkjet head described in, the ink composition is ejected from the entire sub-scanning direction SS of each nozzle column. When the white ink composition is ejected from the nozzle column N1 and the non-white ink composition is ejected from the nozzle column N2 for scanning, the nozzle column N1 and the nozzle column N2 have a part that overlaps in the sub-scanning direction SS when projected in the main scanning direction MS. In this case, through the same main scan of the inkjet head, the white ink composition and the non-white ink composition are attached to the same area of the recording medium.

[0036] In the case of the above example, the same area is the overlapping portion of nozzle column N1 that ejects white ink and nozzle column N2 that ejects non-white ink in the sub-scanning direction SS when nozzle columns N1 and N2 are projected in the main scanning direction MS.

[0037] In addition, use Figure 3 to explain the nozzle control of the recording head 2 when performing the second recording mode. In the inkjet head described in Figure 3 , there is an area where blocks B1 and B2 are divided in the sub-scanning direction SS. In this inkjet head, the type of ejected droplets can be changed for each block and nozzle column. For example, in Figure 3 , the inkjet head can be controlled to eject white ink in block B1 of nozzle column N1 and non-white ink in block B2 of nozzle column N2.

[0038] In this case, in a certain main scan, the white ink ejected from block B1 of nozzle column N1 adheres to the recording medium, the recording medium M slightly moves in the sub-scanning direction SS, and in the next main scan, the non-white ink ejected from block B2 of nozzle column N2 adheres to the recording medium in a manner that overlaps the already adhered white ink. Thus, through different main scans of the inkjet head, the white ink composition and the non-white ink composition adhere to the same area of the recording medium.

[0039] In the case of the above example, the same area is the portion where the white ink composition and the non-white ink composition are laminated and adhered through different main scans.

[0040] As another example of the second recording mode, for example, in the nozzle control of Figure 2 , white ink composition can be ejected from nozzle column N1, the white ink composition adheres to the recording medium to form an ink layer of the white ink composition, and then the recording medium is wound back, and non-white ink composition is ejected from nozzle column N2 in a manner that overlaps the ink layer of the white ink composition and adheres.

[0041] In addition, the nozzle control of the recording head 2 is not limited to the above method. For example, in the method of Figure 3 , it is controlled to eject white ink from block B1 of nozzle column N1 and non-white ink from block B1 of nozzle column N2, so that through the same main scan, the white ink composition and the non-white ink composition adhere to the same area of the recording medium, thereby performing the first recording mode. In addition, for example, in the method of Figure 2 , in a certain main scan, white ink can be ejected from nozzle column N1 without moving the recording medium M in the sub-scanning direction SS, and in the next main scan, the non-white ink ejected from nozzle column N2 adheres to the recording medium in a manner that overlaps the already adhered white ink, thereby performing the second recording mode.

[0042] In Figure 1 it, the ink cartridge 3 for supplying a white ink composition or the like to the recording head 2 is composed of four independent ink cartridges. For example, a white ink composition is filled in one of the four ink cartridges, and different types of non-white ink compositions are filled in the other ink cartridges respectively. The ink cartridge 3 is mounted so as to be detachable from the recording head 2. In Figure 1 the example of, the number of ink cartridges is four, but it is not limited thereto, and the required number of ink cartridges can be mounted.

[0043] In addition, a platen 5 is disposed below the recording head 2, and the recording medium M is conveyed to the platen 5. In addition, the recording apparatus 1 may further include a heating mechanism 6 for heating the recording medium M. The heating mechanism is one of the drying mechanisms.

[0044] The heating mechanism 6 only needs to be provided at a position where the recording medium M can be heated, and its installation position is not particularly limited. In Figure 1 the example of, the heating mechanism 6 is provided on the platen 5 and at a position facing the recording head 2. If the heating mechanism 6 is provided at a position facing the recording head 2, the attachment positions of the white ink composition and the non-white ink composition in the recording medium M can be reliably heated, and the white ink composition and the non-white ink composition attached to the recording medium M can be effectively dried.

[0045] As the heating mechanism 6, for example, a printing heater mechanism that brings the recording medium M into contact with a heat source and heats it, a mechanism that irradiates infrared rays or electromagnetic waves having a maximum wavelength of about 2450 MHz, that is, microwaves, a drying mechanism that blows hot air, a platen heater, etc. can be cited.

[0046] The heating of the recording medium M by the heating mechanism 6 is performed before, during, or immediately after the droplets ejected from the nozzles of the recording head 2 adhere to the recording medium M. The control of each heating condition, for example, the timing of heating implementation, the heating temperature, the heating time, etc. are performed by the control unit CONT.

[0047] 1.2. Carriage

[0048] The carriage 4 can carry a white inkjet head and a non-white inkjet head as the recording head 2, and can detachably mount the ink cartridge 3 that supplies each ink composition to the recording head 2.

[0049] The carriage 4 is mounted in a state supported by a guide bar 9 which is a support member erected in the main scanning direction, and moves in the main scanning direction along the guide bar 9 by a carriage moving mechanism 7. By relatively moving the carriage 4 with respect to the recording medium while ejecting the ink composition from the recording head 2 mounted on the carriage 4, the ink composition can be attached to the recording medium M.

[0050] The relative movement of the carriage 4 only needs to move either the carriage 4 or the recording medium M relative to the other, without limitation. Therefore, in Figure 1 In the example of, the carriage 4 moves in the main scanning direction, but it is not limited thereto, and it may also be a method (lateral scanning method) in which multiple main scans and sub-scans based on head movement are performed on a fixed recording medium.

[0051] The carriage moving mechanism 7 moves the carriage 4 in the medium width direction of the recording medium M. The medium conveying mechanism 8 conveys the recording medium M in the medium conveying direction. Here, the medium width direction is the main scanning direction MS as the operation direction of the recording head 2. The medium conveying direction is a direction orthogonal to the main scanning direction MS and is the sub-scanning direction SS in which the recording medium M moves.

[0052] 1.3. Control unit

[0053] The control unit CONT can control the overall operation of the printer 1. For example, the control unit CONT can perform control for executing recording by performing multiple main scans, and while relatively moving the carriage 4 relative to the recording medium, eject each ink composition from the recording head 2 and attach it to the recording medium M.

[0054] In particular, in the present embodiment, the control unit CONT executes: a first recording mode in which the white ink composition and the non-white ink composition are attached to the same scan area of the recording medium by the same main scan; and a second recording mode in which the white ink composition and the non-white ink composition are attached to the same scan area of the recording medium by different main scans.

[0055] 1.3.1. First recording mode

[0056] In the first recording mode, the white ink composition and the non-white ink composition are attached to the same scan area of the recording medium by the same main scan, thereby forming a layer containing the white ink composition and the non-white ink composition. Thus, there is no need to stack layers of the ink composition, so the recording speed can be increased. In addition, on this basis, in the image obtained in the first recording mode, when the recording medium is transparent, the image seen from the front surface and the image seen from the back surface look the same respectively. Therefore, for example, in the case of a recording object used by being pasted on a window or glass, an image that can be seen from both the front and back can be obtained.

[0057] In the first recording mode, it is also possible to perform main scanning for attaching the white ink composition and the non-white ink composition to the scanning area multiple times on the same area. That is, preferably, after a certain main scanning attaches a layer containing the white ink composition and the non-white ink composition to a certain area on the recording medium, another main scanning is further performed thereon to overlap and attach a layer containing the white ink composition and the non-white ink composition. In this case, the main scanning for attaching the white ink composition and the non-white ink composition passes through the same area multiple times. The more the number of scans, the more the ink can be attached to the desired area in multiple times (multi-pass), and there is a tendency that the image quality of the obtained recording is further improved.

[0058] In addition, when recording any area, the number of times the inkjet head has passed over that area is also referred to as a "pass". For example, in the case of performing four main scans for attaching the white ink composition and the non-white ink composition on the same area, the number of passes is referred to as 4 passes, etc. For example, in Figure 2 In the example, when the length of one sub-scan in the sub-scanning direction is one-fourth of the length of the nozzle row N1 in the sub-scanning direction, a rectangular scanning area having a length of one sub-scan in the sub-scanning direction and extending in the main scanning direction is scanned four times. The number of scans when observed in the above manner is referred to as the number of scans or the number of passes, etc. The number of scans is 1 or more, preferably 2 or more, more preferably 3 or more, further preferably 4 or more, and particularly preferably 8 or more. There is no limit to the upper limit, but it is preferably 24 or less, more preferably 12 or less.

[0059] In addition, the number of scans described above is set for each ink type.

[0060] Furthermore, in the first recording mode, it is also possible to form a layer containing the white ink composition by a main scanning different from the main scanning for forming a layer containing the white ink composition and the non-white ink composition, and laminate a layer containing the white ink composition and the non-white ink composition and a layer containing the white ink composition. Thereby, by forming a layer containing the white ink composition, an image with higher color rendering property can be obtained. Compared with the formation of a layer containing the white ink composition and the non-white ink composition, the formation of a layer containing the white ink composition can be performed before or after. In the case of performing it before, it becomes a recording used for visually confirming an image from the recording surface side of the recording medium. In the case of performing it after, it becomes a recording used for visually confirming an image from the side opposite to the recording surface side of the recording medium.

[0061] 1.3.2. Second recording mode

[0062] In the second recording mode, by different main scans, the white ink composition and the non-white ink composition are attached to the same scanning area of the recording medium, whereby a layer containing the white ink composition and a layer containing the non-white ink composition are laminated. Thus, concealment is ensured by the layer containing the white ink composition, and therefore the color development property and visual recognition property of the non-white ink composition formed thereon are further improved, and high-quality image quality can be obtained.

[0063] In addition, in the second recording mode, as long as the white ink composition and the non-white ink composition are attached by different main scans, the order thereof is not limited. For example, when the white ink composition is attached first and the non-white ink composition is attached thereon, an image can be formed when viewed from the ink-attached surface side. In addition, on the contrary, when the recording medium is transparent, when the non-white ink composition is attached first and the white ink composition is attached thereon, an image can be formed when viewed from the non-ink-attached surface side of the ink.

[0064] In the second recording mode, for the same scanning area, different main scans for attaching the white ink composition and the non-white ink composition to the scanning area may be performed multiple times respectively. For example, it is possible to consider recording the white ink composition in 4 passes, and then recording the non-white ink composition in 4 passes.

[0065] 1.3.3. Amount of attachment

[0066] The control unit CONT preferably controls such that in the area where the amount of attachment of the non-white ink composition is the largest in the area of the recording medium to which the white ink composition and the non-white ink composition are attached, the ratio of the amount of attachment of the white ink composition to the amount of attachment of 100% by mass of the non-white ink composition is ratio A, and when calculating this ratio A, it is controlled such that ratio A1 in the first recording mode is less than ratio A2 in the second recording mode.

[0067] In addition, the ratio of the amount of attachment represents the amount of attachment of the white ink composition / the amount of attachment of the non-white ink composition in terms of ratio, and assuming that the amounts of attachment of both are equal, it is 100% by mass.

[0068] In the first recording mode, an ink layer mixed with white ink is formed, so even if the same amount of white ink composition is used, the recorded object is more likely to turn white compared to the second recording mode. In this regard, by controlling in the above manner, higher-quality images can be obtained in both the first recording mode and the second recording mode. In addition, the unit area when specifying the amount of attachment is an area having a specified area, and for example, it can be set as an area of 2 × 2 mm.

[0069] The ratio A1 of the first recording mode based on the control of the control unit CONT is preferably less than 80% by mass, more preferably 5 to 75% by mass, further preferably 10 to 75% by mass, still further preferably 30 to 70% by mass, and even further preferably 35 to 65% by mass. By making the ratio A1 less than 80% by mass, there is a tendency for the color rendering property to be further improved and the unevenness of shading to be further reduced. In addition, by making the ratio A1 within the above range or more, there is a tendency for the visual recognition property to be further improved.

[0070] In addition, in the first recording mode, when the amount of the non-white ink composition in the region with the largest amount of the non-white ink composition among the regions where the white ink composition and the non-white ink composition are attached is defined as the maximum non-white ink attachment amount B1, in the region where the amount of the non-white ink composition in the region where the white ink composition and the non-white ink composition are attached is from the region of the maximum non-white ink attachment amount B1 to 40% by mass of the maximum non-white ink attachment amount B, the ratio of the attachment amount is preferably within the above range.

[0071] In addition, the region where the amount of the non-white ink composition in the region where the white ink composition and the non-white ink composition are attached is less than 40% by mass of the maximum non-white ink attachment amount B1 is a region where the color of the image of the non-white ink composition is relatively light and the quality of the original image is not significantly different. However, for this region, the ratio of the attachment amount can also be set within the above range, above the above range, or below the above range. When giving priority to the color rendering property, it can be set within the above range or below the above range. When giving priority to the visual recognition property, it can be set within the above range or above the above range.

[0072] The ratio A2 of the second recording mode based on the control of the control unit CONT is preferably 80% by mass or more, more preferably 85 to 200% by mass, and further preferably 90 to 160% by mass. By making the ratio A2 80% by mass or more, there is a tendency for the visual recognition property to be further improved. In addition, by making the ratio A2 200% by mass or less, there is a tendency for the unevenness of shading to be further reduced and the adhesion property to be further improved.

[0073] In addition, in the second recording mode, when the amount of the non-white ink composition in the region with the largest amount of the non-white ink composition among the regions where the white ink composition and the non-white ink composition are attached to the recording medium is defined as the maximum non-white ink attachment amount B2, in the region where the amount of the non-white ink composition in the region where the white ink composition and the non-white ink composition are attached is less than the maximum non-white ink attachment amount B2, it is preferable to make the ratio of the attachment amount within the above range or above the above range, that is, within the above range or more.

[0074] In the second recording mode, when the ratio of the coating amount is large, there is also a tendency for excellent visual recognition and color development properties. Even when the coating amount range is above the above range, excellent visual recognition and color development properties can be obtained.

[0075] In the first recording mode, the maximum coating amount of the white ink composition in the region where the white ink composition and the non-white ink composition are overlapped and coated is preferably 10 mg / inch 2 More preferably, it is 8 mg / inch or less 2 Hereinafter.

[0076] The lower limit of the maximum coating amount of the above white ink composition is preferably 0.50 mg / inch 2 More preferably, it is 1.0 mg / inch or more 2 More preferably, it is 3.0 mg / inch or more 2 Particularly preferably, it is 5.0 mg / inch or more 2 Hereinafter.

[0077] In addition, the maximum coating amount of the non-white ink composition is not particularly limited as long as it is a coating amount corresponding to the image to be recorded, but it is preferably such that the ratio A1 is within the above preferred range.

[0078] Thereby, it is possible to suppress the obtained image from being overly white, and there is a tendency for further improvement in visual recognition and color development properties.

[0079] In the second recording mode, the maximum coating amount of the white ink composition in the region where the white ink composition and the non-white ink composition are overlapped and coated is preferably 15 mg / inch 2 More preferably, it is the same as the preferred range in the above first recording mode. The maximum coating amount of the non-white ink composition is the same as the preferred range in the above first recording mode.

[0080] The linear encoder 10 detects the position of the carriage 4 in the main scanning direction by a signal. The signal detected by the linear encoder 10 is sent as position information to the control unit CONT. The control unit CONT identifies the scanning position of the recording head 2 based on the position information from the linear encoder 10, and controls the recording operation of the recording head 2, that is, the ejection operation and the like. In addition, the control unit CONT is configured to be able to variably control the moving speed of the carriage 4.

[0081] 1.4. Ink Composition

[0082] The white ink composition used in this embodiment contains a white pigment, and the non-white ink composition contains a non-white pigment. The white ink composition and the non-white ink composition may each be an aqueous ink composition having water as a main solvent, or may be a solvent-based ink composition having an organic solvent as a main solvent. Hereinafter, the components of the ink composition will be exemplified by taking an aqueous ink composition as an example, but the components constituting the ink composition of this embodiment are not limited to the following components.

[0083] The white ink composition and the non-white ink composition used in this embodiment may be solvent-based inks or aqueous inks, but are each preferably an aqueous ink. Compared with solvent-based inks, aqueous inks have high environmental compatibility in that they contain less organic solvent. On the contrary, aqueous inks tend to have the following problems: the white ink and the non-white ink are easily mixed, resulting in a decrease in color rendering property and uneven density, and in particular, the obtained image is likely to appear whitish. Therefore, the present invention is particularly useful. In addition, the "aqueous" in the "aqueous ink" means that it contains at least water as a main solvent component. The content of water contained in the ink or the like is 40% by mass or more, preferably 50% by mass or more. More preferably, it is 60 to 98% by mass.

[0084] In addition, non-aqueous inks contain an organic solvent as a main solvent component. The content of the organic solvent in the non-aqueous ink is preferably 40% by mass or more, more preferably 50 to 98% by mass. The content of water in the non-aqueous ink is preferably 1% by mass or less, more preferably 0.5% by mass or less. The components other than the solvent component of the non-aqueous ink may be the same as the components that can be contained in the aqueous ink described later.

[0085] In the case of an aqueous ink composition, the white ink composition and the non-white ink composition may, in addition to the above pigments, optionally contain water, an organic solvent, a surfactant, resin particles, etc. Hereinafter, the components of the ink composition will be described in detail by taking an aqueous ink as an example.

[0086] 1.4.1. White Pigment

[0087] The white pigment is not particularly limited, and examples thereof include C.I. Pigment White 6, 18, 21, silica, alumina, titanium dioxide, zinc oxide, antimony oxide, magnesium oxide, zirconium oxide, zinc sulfide, barium sulfate, calcium carbonate and other white inorganic pigments. In addition to the white inorganic pigments, white organic pigments such as white hollow resin particles and polymer particles may also be used.

[0088] Among the above examples of the white pigment, titanium dioxide is preferably used from the viewpoint of good whiteness and the like. The white pigment may be used alone or in combination of two or more.

[0089] The content of the white pigment is preferably 1.0% by mass or more, more preferably 3.0% by mass or more, still more preferably 5.0% by mass or more, and particularly preferably 8.0% by mass or more, relative to the total amount of the white ink composition. In addition, the content of the white pigment is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 12.5% by mass or less, and particularly preferably 10% by mass or less, relative to the total amount of the white ink composition. By setting the content of the white pigment within the above range, images with higher image quality can be obtained in the first recording mode and the second recording mode.

[0090] In the second recording mode, the white ink composition is sometimes used for the purpose of concealing the image background. On the other hand, in the first recording mode, it is used rather for the purpose of improving the visual recognition of the image obtained by using it in combination with a non-white ink composition than for the purpose of concealment. Therefore, the content of the white pigment in the white ink composition can be further reduced compared with the case where the purpose is background concealment. As a result, sufficient visual recognition of the image can be obtained, and it is easy to make the dispersion stability of the white pigment good and difficult to settle. Furthermore, filling and image quality deterioration are also more excellent, so it is preferred.

[0091] The white pigment is preferably capable of being stably dispersed in the dispersion medium, so a dispersant can also be used to disperse it. Examples of the dispersant include resin dispersants, etc., which are selected from dispersants that can make the dispersion stability of the white pigment in the white ink composition containing the above white pigment good. In addition, the white pigment can also be used as a self-dispersing type pigment by oxidizing the surface of the pigment with ozone, hypochlorous acid, fuming sulfuric acid, etc., or by sulfonating to modify the surface of the pigment particles.

[0092] 1.4.2. Non-white pigments

[0093] The non-white pigment is not particularly limited as long as it is a pigment other than the above white pigment. For example, it can be mentioned: carbon blacks (C.I. Pigment Black 7) such as furnace black, lamp black, acetylene black, channel black, etc.; inorganic pigments; organic pigments such as quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthraquinone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, violanthrone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. The non-white pigment can be used alone or in combination of two or more.

[0094] The content of the non-white colorant is preferably 0.5 to 10% by mass, more preferably 0.5 to 7.5% by mass, still more preferably 0.5 to 6.0% by mass, and even more preferably 1.0 to 5.0% by mass, relative to the total amount of the non-white ink composition. By setting the content of the non-white colorant within the above range, the color rendering property and visual recognition property are further improved, and images with higher image quality can be obtained in the first recording mode and the second recording mode.

[0095] The non-white colorant is preferably capable of being stably dispersed in the dispersion medium, and thus a dispersant may also be used to disperse it. Examples of the dispersant include resin dispersants, etc., which are selected from dispersants that can provide good dispersion stability of the non-white colorant in the non-white ink composition containing the above non-white colorant. In addition, the non-white colorant can also be used as a self-dispersing pigment, for example, by oxidizing the surface of the pigment with ozone, hypochlorous acid, fuming sulfuric acid, etc., or by sulfonation to modify the surface of the pigment particles.

[0096] There is no limitation on the non-white ink composition containing the non-white colorant, and examples thereof include cyan ink, yellow ink, magenta ink, black ink, etc.

[0097] 1.4.3. Water

[0098] The content of water is preferably 45 to 98% by mass, more preferably 55 to 90% by mass, still more preferably 60 to 85% by mass, and even more preferably 65 to 80% by mass, relative to the total amount of the ink composition.

[0099] 1.4.4. Organic Solvent

[0100] There is no particular limitation on the organic solvent as long as it is a water-soluble organic solvent. Examples thereof include polyhydric alcohols having three or more hydroxyl groups such as glycerol; diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether; nitrogen-containing solvents such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone; and alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tert-butanol, isobutanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol. The organic solvent can be used alone or in combination of two or more.

[0101] Diols are compounds having two hydroxyl groups in the molecule. Examples of diols include alkane diols in which an alkane is substituted by two hydroxyl groups, condensates obtained by intermolecular condensation between two or more hydroxyl groups of such alkane diols, and the like.

[0102] The number of carbon atoms in the molecule of the diols is preferably 2 to 10, more preferably 3 to 8, still more preferably 3 to 6, and particularly preferably 3 to 5.

[0103] Examples of the alkane diols preferably include 1,2-alkane diols and double-terminal alkane diols.

[0104] Examples of the nitrogen-containing solvents include amide solvents. Examples of the amide solvents include acyclic amides and cyclic amides.

[0105] Examples of the cyclic amides include lactams. For example, the above lactams, pyrrolidone compounds such as 1-propyl-2-pyrrolidone and 1-butyl-2-pyrrolidone, N-methyl-ε-caprolactam, N-cyclohexyl-2-pyrrolidone, β-propiolactam, and the like can be cited.

[0106] Examples of the acyclic amides include alkoxyalkylamides such as 3-methoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-diethylpropanamide, 3-methoxy-N,N-methylethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-diethylpropanamide, 3-ethoxy-N,N-methylethylpropanamide, 3-n-butoxy-N,N-dimethylpropanamide, 3-n-butoxy-N,N-diethylpropanamide, 3-n-butoxy-N,N-methylethylpropanamide, 3-n-propoxy-N,N-dimethylpropanamide, 3-n-propoxy-N,N-diethylpropanamide, 3-n-propoxy-N,N-methylethylpropanamide, 3-isopropoxy-N,N-dimethylpropanamide, 3-isopropoxy-N,N-diethylpropanamide, 3-isopropoxy-N,N-methylethylpropanamide, 3-tert-butoxy-N,N-dimethylpropanamide, 3-tert-butoxy-N,N-diethylpropanamide, 3-tert-butoxy-N,N-methylethylpropanamide, and the like; N,N-dimethylacetoacetamide, N,N-diethylacetoacetamide, N-methylacetamide, N,N-dimethylisobutyramide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropanamide, and the like.

[0107] Polyols having three or more hydroxyl groups are compounds having three or more hydroxyl groups in the molecule. For example, glycerol can be cited.

[0108] Glycol ethers are compounds in which one or two of the hydroxyl groups in an alkane diol with two hydroxyl groups substituting for the alkane or a condensate obtained by intermolecular condensation between two or more molecules of the alkane diol are etherified. The etherification is either monoetherification or dietherification. Alkyl etherification is preferred for the etherification. Glycol ethers are compounds having one hydroxyl group or no hydroxyl group in the molecule. Examples of glycol ethers include the above-mentioned glycol ethers.

[0109] Alcohols are compounds in which an alkane is substituted by one hydroxyl group and have one hydroxyl group in the molecule. Examples of alcohols include the above-mentioned alcohols.

[0110] In the organic solvent, glycol-based solvents such as propylene glycol, 1,3-propanediol, and 1,2-hexanediol, nitrogen-containing solvents such as 2-pyrrolidone, and glycerol are preferred. By using such organic solvents, there is a tendency for the image quality and recording speed of the obtained recording to be further improved.

[0111] Relative to the total amount of the ink composition, the content of the organic solvent is preferably 1.0 to 40% by mass, more preferably 3.0 to 30% by mass, still more preferably 5.0 to 15% by mass, and even more preferably 7.5 to 15% by mass.

[0112] The content of the organic solvent of glycols can be within the above range.

[0113] Relative to the total amount of the ink composition, the content of the nitrogen-containing solvent is preferably 40% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 2% by mass or less. The lower limit is 0% by mass or more.

[0114] By making the content of the organic solvent within the above range, there is a tendency for the color development property and recording speed of the obtained recording to be further improved.

[0115] When the content of the nitrogen-containing solvent is within the above range or less, the image quality, adhesion, etc. are more excellent, so it is preferred.

[0116] The standard boiling point of the organic solvent is preferably 150 to 280 °C, preferably 160 to 270 °C, preferably 170 to 260 °C. More preferably 180 to 200 °C, and still more preferably 190 to less than 200 °C.

[0117] By making the standard boiling point of the organic solvent within the above range, there is a tendency for the adhesion to be further improved.

[0118] In particular, relative to the total amount of the organic solvents, the content of the organic solvents having a standard boiling point of less than 200°C in the white ink composition and the non-white ink composition is preferably 50% by mass or more, particularly preferably 55% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass or more. In addition, the upper limit of the content of the organic solvents having a standard boiling point of less than 200°C is 100% by mass or less, preferably 95% by mass or less, and may also be 90% by mass or less. In particular, the content of the organic solvents having a standard boiling point of less than 200°C in the organic solvents contained in the white ink composition is preferably within the above range. By making the content of the organic solvents having a standard boiling point of less than 200°C within the above range, there is a tendency for the adhesion to be further improved.

[0119] In addition, the white ink composition and the non-white ink composition preferably contain an organic solvent having a standard boiling point of less than 200°C and an organic solvent having a standard boiling point of 200°C or higher.

[0120] The organic solvent having a standard boiling point within the above range is preferably a glycol-based organic solvent.

[0121] In addition, the maximum value of the standard boiling point of the organic solvents contained in the white ink composition and the non-white ink composition is preferably 280°C or lower. Further, it is preferably 250°C or lower, more preferably 240°C or lower, and further preferably 230°C or lower. In addition, the maximum value of the standard boiling point of the organic solvents is preferably 150°C or higher, and more preferably 160°C or higher. In particular, the maximum value of the standard boiling point of the organic solvents contained in the white ink composition is preferably within the above range. By making the maximum value of the standard boiling point within the above range, there is a tendency for the adhesion to be further improved.

[0122] The weighted average of the standard boiling points of the organic solvents contained in the white ink composition and the non-white ink composition is preferably 290°C or lower, and further preferably 250°C or lower. Further, it is preferably 230°C or lower, more preferably 220°C or lower, further preferably 210°C or lower, and particularly preferably 200°C or lower. In addition, the weighted average of the standard boiling points of the organic solvents is preferably 150°C or higher, and more preferably 160°C or higher. In particular, the weighted average of the standard boiling points of the organic solvents contained in the white ink composition is preferably within the above range. By making the weighted average of the standard boiling points within the above range, there is a tendency for the adhesion to be further improved.

[0123] In particular, the white ink composition and the non-white ink composition are each an aqueous ink composition, preferably not containing more than 2% by mass of an organic solvent that is a diol or a polyol having three or more hydroxyl groups with a standard boiling point exceeding 280°C. "Not containing more than 2% by mass" means that the alkyl polyol is 0% by mass, or even if it is contained, it is contained within the non-exceeding range. Further, it is preferably not containing more than 1% by mass, and more preferably not containing more than 0.5% by mass.

[0124] The content of the organic solvent with a standard boiling point exceeding 280°C can be within the above range.

[0125] 1.4.5. Surfactant

[0126] There is no particular limitation on the surfactant. For example, an alkynediol-based surfactant, a fluorine-based surfactant, and a silicone-based surfactant can be mentioned. Among them, a silicone-based surfactant is preferred. Thereby, there is a tendency to further suppress unevenness in density of the obtained recording.

[0127] There is no particular limitation on the alkynediol-based surfactant. For example, one or more selected from 2,4,7,9-tetramethyl-5-decyn-4,7-diol and an alkylene oxide adduct of 2,4,7,9-tetramethyl-5-decyn-4,7-diol, and 2,4-dimethyl-5-decyn-4-ol and an alkylene oxide adduct of 2,4-dimethyl-5-decyn-4-ol are preferred.

[0128] There is no particular limitation on the fluorine-based surfactant. For example, perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl phosphates, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl betaines, and perfluoroalkyl amine oxide compounds can be mentioned.

[0129] Examples of the silicone-based surfactant include polysiloxane-based compounds and polyether-modified silicone oxides.

[0130] The content of the surfactant is preferably 0.1 to 4.0% by mass, more preferably 0.3 to 3.0% by mass, and still more preferably 0.5 to 2.0% by mass with respect to the total amount of the ink composition. Thereby, there is a tendency to further suppress unevenness in density of the obtained recording.

[0131] 1.4.6. Resin particles

[0132] By using resin particles, the adhesion of the obtained image is further improved. There are no particular limitations on the resin particles. For example, resin particles composed of urethane resins, acrylic resins (including styrene-acrylic resins), fluorene resins, polyolefin resins, rosin-modified resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate resins, etc. can be cited. The resin particles can also be in the form of an emulsion.

[0133] Among them, urethane resins, acrylic resins, and polyolefin resins are preferred. Most of these resin particles are processed in the form of an emulsion, but they can also be in the form of a powder. In addition, one type of resin particle can be used alone or two or more groups can be used in combination.

[0134] Urethane resins are a general term for resins having urethane bonds. In addition to urethane bonds, polyether-type urethane resins having an ether bond in the main chain, polyester-type urethane resins having an ester bond in the main chain, polycarbonate-type urethane resins having a carbonate bond in the main chain, etc. can also be used for urethane resins.

[0135] Acrylic resins are a general term for polymers obtained by polymerizing at least acrylic monomers such as (meth)acrylic acid and (meth)acrylate as one component. For example, resins obtained from acrylic monomers, copolymers of acrylic monomers and other monomers, etc. can be cited. For example, acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers, can be cited. In addition, for example, styrene etc. can be cited as vinyl monomers. Acrylamide, acrylonitrile, etc. can be used as acrylic monomers.

[0136] Among them, styrene-acrylic resins are preferred. There are no particular limitations on the styrene-acrylic resins. For example, styrene-acrylic copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylate copolymers, styrene-α-methylstyrene-acrylic copolymers, styrene-α-methylstyrene-acrylic-acrylate copolymers, etc. can be cited. By using such resins, there is a tendency to further improve the image quality and adhesion of the obtained recording material.

[0137] Polyolefin resins have olefins such as ethylene, propylene, and butene in the structural skeleton, and publicly known polyolefin resins can be appropriately used.

[0138] Relative to the total amount of the ink composition, the content of the resin particles is preferably 0.5 to 15% by mass, more preferably 1.0 to 10% by mass, and still more preferably 2.5 to 7.5% by mass. By making the content of the resin particles within the above range, there is a tendency to further improve the adhesion of the obtained recording material.

[0139] 1.4.7. Other Components

[0140] The ink composition may also contain components such as preservatives / mildew-proof agents, rust inhibitors, chelating agents, viscosity modifiers, antioxidants, and mildew-proof agents as needed.

[0141] 1.5. Recording Medium

[0142] The recording medium used in this embodiment is not particularly limited. For example, absorbent recording media such as paper, film, and cloth, low-absorbent recording media such as printing paper, and non-absorbent recording media such as metal, glass, and polymers can be cited.

[0143] Among them, from the viewpoint of ink absorbency, low-absorbent recording media or non-absorbent recording media are preferred. In addition, from the viewpoint of color, non-white recording media are preferred. Such recording media have conventionally formed a white ink layer and a non-white ink layer by overlapping, used the white ink layer as a concealer layer, and recorded high-quality images. Therefore, by using the present invention, the effect of the present invention of forming an image without uneven shading and having excellent color rendering can be particularly effectively exerted.

[0144] In this embodiment, the non-absorbent or low-absorbent recording medium means "a recording medium having a water absorption amount of 10 mL / m or less from the start of contact to 30 msec in the Bristow method". 1 / 2 up to 2 This Bristow method is the most popular method as a method for measuring the liquid absorption amount in a short time and is also adopted by the Japan Pulp and Paper Technical Association (JAPANTAPPI). The details of the test method are described in Standard No. 51, "Paper and Board - Liquid Absorbency Test Method - Bristow Method" of "JAPAN TAPPI Pulp Test Methods 2000 Edition".

[0145] Examples of non-absorbent recording media include recording media coated with plastic on a substrate such as paper, recording media adhered with a plastic film on a substrate such as paper, and plastic films without an absorption layer (receiving layer). Examples of plastics referred to herein include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

[0146] In addition, examples of low-absorbent recording media include recording media provided with a low-absorbent coating layer on the surface. For example, coated paper is known. For example, as recording media with paper as the substrate, printing papers such as coated paper, coated paper, and matte paper can be cited. In the case where the substrate is a plastic film, recording media coated with a polymer or the like on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc., and recording media coated with particles such as silica and titanium together with an adhesive can be cited.

[0147] As the recording medium, an absorbent recording medium can be used. The absorbent recording medium refers to a recording medium whose water absorption amount exceeds 10 mL / m from the start of contact to 30 msec in the above-mentioned "Bristow method". 1 / 2 until 2 ".

[0148] As a non-white recording medium, a transparent recording medium (transparent recording medium) can be cited. The transparent recording medium can also be colorless and transparent, colored (colored) transparent. In addition, transparency also includes translucency. These are recording media with visual light transmissibility. In addition, they are recording media with visible light transmissibility. In this case, by the recording method of the present embodiment, the image formed on one side of the recording medium can be visually confirmed well from both sides.

[0149] In addition, as a non-white recording medium, a non-white colored recording medium (non-white colored recording medium) can be cited. A non-white colored opaque recording medium, a non-white colored transparent recording medium, etc. can be cited. In this case, by the recording method of the present embodiment, it is also possible to easily form an image with good image quality such as visual recognition, filling, and reduced image quality difference. The non-white colored recording medium can be the above-mentioned transparent recording medium, or it can not be a transparent recording medium. A recording medium that is not a transparent recording medium is a recording medium that does not have visual light transmissibility. In addition, it is a recording medium that is opaque to visible light. Here, non-white colored means colored other than white.

[0150] 2. Recording method

[0151] The recording method of the present embodiment uses the above-mentioned recording device, selects either the first recording mode or the second recording mode, and performs recording based on the selected recording mode.

[0152] The user can pre-select the first recording mode and the second recording mode, and the recording device executes one of the first recording mode and the second recording mode according to the selection. In this case, the recording mode can be selected on the operation unit of the recording device or on the boot setting screen of the computer that transmits the image data of the recording device and instructs recording.

[0153] In addition, as another method, the control unit of the recording device can select either the first recording mode or the second recording mode according to the information of the recording medium and the recorded image data and execute it. In addition, when the control unit of the recording device selects the first recording mode and the second recording mode, the control unit of the recording device can have data that associates the recording medium and the recorded image data with the selected recording mode, and can select and execute one of the first recording mode and the second recording mode based on such data.

[0154] In the first recording mode, the control unit ejects a white ink composition and a non-white ink composition during the same main scan and attaches them to the same scanning area. Then, the recording medium is moved by sub-scanning to perform the next main scan.

[0155] In addition, in the second recording mode, the control unit ejects either the white ink composition or the non-white ink composition during a certain main scan and attaches it to a certain scanning area. Then, the recording medium is moved by sub-scanning, and during the next main scan, the other of the white ink composition or the non-white ink composition is ejected so that the other ink composition is attached to the scanning area where the one ink composition was attached during the previous main scan.

[0156] Figure 4 It is a flowchart showing an example of the process for controlling recording performed by the recording apparatus used in the present embodiment. When starting recording, the control unit of the recording apparatus determines the recording mode in step S400. The recording mode refers to the manner, method, or form of recording.

[0157] The determination of the recording mode is determined, for example, based on an input signal input from an external device such as a computer to the recording apparatus, or based on input information from a user to a user input unit provided in the recording apparatus. Here, the input signal from the external device and the input information of the user can be information directly specifying the recording mode, or can be information related to recording such as the specification of the recording speed, the specification of the image quality, etc. The information related to recording is not limited to this. In the latter case, the recording apparatus records correspondence information that has previously determined the recording mode corresponding to the information related to recording in a recording unit such as the control unit, and determines the recording mode with reference to the correspondence information.

[0158] In step S401, the determined recording mode is judged. In step S402 or S403, based on the determined recording mode, the recording apparatus is controlled under recording conditions corresponding to the recording mode. The recording conditions are, for example, the selection of the part used in the recording of the nozzle array required for recording in the first recording mode or the second mode. In addition, it may also include control related to the operation of the recording apparatus, etc. For example, it is control conditions related to recording such as the maximum ink adhesion amount, the conditions for one-time drying, etc.

[0159] Recording is performed in step S404. Two types of recording modes are shown in the figure, and there can also be three or more types. As shown in the figure, the control of the recording apparatus can be performed before the start of recording, but can also be performed during recording. That is, as long as recording is performed in a state where the recording apparatus is controlled by the recording conditions.

[0160] Accordingly, the first recording mode or the second recording mode is selected and performed according to the required image quality, recording speed, etc., whereby it is possible to perform image recording with excellent image quality, and in addition, it is also possible to perform recording with excellent recording speed.

[0161] In each recording mode, a primary drying process may also be provided.

[0162] The primary drying process is a process of early drying the white ink composition and the non-white ink composition attached to the recording medium by a drying mechanism. In particular, it refers to early drying of the areas to which the white ink composition and the non-white ink composition are attached in the white ink application process and the non-white ink application process.

[0163] The primary drying process is a process of drying the ink attached to the recording medium at an early stage. The primary drying process is a process for drying at least a part of the solvent component of the ink attached to the recording medium to at least a degree that reduces the flow of the ink. In the primary drying process, the ink composition may be attached to the heated recording medium, or drying may be performed at the position of the recording medium facing the inkjet head, or drying may be performed early after attachment. The primary drying process preferably starts drying the ink droplets attached to the recording medium within 0.5 seconds from the attachment of the droplets.

[0164] The drying mechanism in the primary drying process is not particularly limited. For example, a conduction type using a platen heater, a pre-heater, etc. for heating, a radiation type using an IR heater, etc. for heating, and a blowing type using a blower fan, etc. may be mentioned. Blowing promotes evaporation by removing the evaporated solvent component from the medium, and the image quality is excellent. The blowing type is not limited to hot air, and may also be normal temperature air. If it is normal temperature air, it is also preferable in terms of not having a thermal effect on the nozzles.

[0165] The drying mechanism is also referred to as a drying unit. The drying unit may use one of these alone, or may use two or more in combination. In particular, it is preferably to use any one of the conduction type and the radiation type and the blowing type, and more preferably to use the conduction type and the blowing type. In this case, heating can be performed by any one of the conduction type and the radiation type, and evaporation can be promoted by the blowing type, and the image quality is more excellent. In this case, the blowing of the blowing type may be hot air or normal temperature air, but from the viewpoint of more excellent ejection stability, normal temperature air is preferable.

[0166] The surface temperature of the recording medium in the primary drying process is preferably 25°C or higher. In addition, it is preferably 60°C or lower. Further, it is preferably 30 to 50°C, more preferably 35 to 45°C, and further preferably 40 to 45°C. Or it is preferably 30 to 40°C, more preferably 30 to 35°C.

[0167] The surface temperature of the recording medium in the primary drying process is set as the maximum temperature in the recording.

[0168] By making the surface temperature of the recording medium in the primary drying process within the above range, there is a tendency for better image quality and the like.

[0169] In each recording mode, a secondary drying process may also be provided.

[0170] The secondary drying process is carried out after the primary drying process for the purpose of further drying the recording. The secondary drying process refers to drying the recording medium with the ink composition attached thereto sufficiently to the extent that the recording can be used, and is the drying for completing the recording. Heating for flattening components such as the resin contained in the ink composition may be included in the secondary drying. Preferably, the heating is as follows: after all the ink attached to a certain area of the recording medium has been attached, heating starts more than 0.5 seconds after the attachment is completed.

[0171] The secondary drying process is also referred to as a post-drying process. The secondary drying process preferably uses heating. The surface temperature of the recording medium in the secondary drying process is preferably 50 to 120°C, more preferably 50 to 100°C, and further preferably 60 to 90°C.

[0172] As the drying method in the secondary drying method, there is no particular limitation, and examples thereof include conduction type such as a platen heater and a pre-heater, radiation type such as an IR heater, and air supply type such as a blower fan.

[0173] Figure 5 Shows a schematic cross-sectional view around the inkjet head of the recording device Figure 1 as viewed from the side. Figure 5 The drying mechanism and the like are also shown therein. The recording device 100 includes: a carriage 2, an inkjet head 3, a platen 4, a platen heater 4a, a pre-heater 7, an IR heater 8, a blower fan 8a, a post-heater 5, and a cooling fan 5a. Recording is performed on the recording medium 1.

[0174] As the drying mechanism for the primary drying process, a conduction type using the platen heater 4a and the pre-heater 7, a radiation type using the IR heater 8, and an air supply type using the blower fan 8a can be used. The primary drying process is carried out using at least any one of these. In the air supply using the blower fan 8a, in the recording medium near the position opposed to the inkjet head 4 in the recording medium conveyance direction, air can be supplied to the ink attached to the recording medium to promote evaporation. The post-heater 5 is a drying mechanism for the secondary drying process.

[0175] Examples

[0176] Hereinafter, the present invention will be described more specifically using examples and comparative examples. The present invention is not limited by any of the following examples.

[0177] 1. Ink composition

[0178] Mix each material according to the composition shown in Table 1 below and stir well to obtain each ink composition. Specifically, each material was uniformly mixed, and insoluble substances were removed through a filter, thereby preparing the ink composition. In addition, in Table 1 below, the unit of the numerical value is mass%, and the total is 100.0 mass%. In addition, unless otherwise specified, it represents the solid content. In addition, the colorant was previously mixed and stirred with a dispersant to prepare a pigment dispersion, which was used for the preparation of the ink. A dispersant resin was used as the dispersant, and a commercially available product suitable for each pigment was mixed at a mass ratio of pigment:dispersant of 2:1.

[0179]

Table 1

[0180]

[0181] ※ The value in () of the organic solvent refers to the standard boiling point.

[0182] Joncryl 537J (acrylic resin particles, manufactured by BASF Japan Co., Ltd.)

[0183] Silface SAG503A (silicone surfactant, manufactured by Nissin Chemical Industry Co., Ltd.)

[0184] 2. Recording examples

[0185] Tables 2 to 3 show the recording methods used in the examples. Table 2 shows the types of white ink compositions and non-white ink compositions used in recording examples A1 to A14 in the first recording mode, as well as recording conditions such as the number of paths, the amount of adhesion, and the primary heating temperature. In addition, the primary drying temperature refers to the surface temperature of the recording medium when the ink is heated by the platen heater.

[0186] Regarding recording example A14, only the number of white paths is 3, which means that initially, the white ink composition was recorded on the recording medium alone at a condition of an adhesion amount of 3 m / inch 2 in 3 paths. Thereafter, the recording medium on which the white ink layer was formed was wound back, and the color 6 mg / inch was recorded in a manner of overlapping with the white ink layer and simultaneously performing 6 paths 2 and white 3 mg / inch 2 . In addition, the ink adhesion amount is the adhesion amount in a 2×2 mm area in the recording pattern.

[0187]

Table 2

[0188]

[0189] Similarly, Table 3 shows the recording examples B1 to B11 of the second recording mode, showing the types of white ink compositions and non-white ink compositions used, as well as recording conditions such as the number of passes, the coating amount, and the primary heating temperature. In the second recording mode, the white ink composition is initially coated with the number of passes and the coating amount in the table, the recording medium with the white ink layer formed is wound back, overlapped on the white ink layer, and the non-white ink composition is coated with the number of passes and the coating amount in the table.

[0190] In addition, for reference examples, recording examples C1 in which only the non-white ink composition is used for recording and C2 in which only the white ink composition is used for recording were also prepared.

[0191]

Table 3

[0192]

[0193] 3. Device Example

[0194] As a recording device, a modified serial inkjet printer (trade name SC-S80650) was prepared. The nozzle density of each nozzle row is 600 npi, the number of nozzles is 600, and the nozzle rows are inkjet heads arranged horizontally in the main scanning direction. The resolution during recording is 1200×1200 dpi.

[0195] The number of ink droplets per pixel and the ink amount of the ink droplets were adjusted so that the coating amount became the value in the table at this resolution. The number of ink droplets per pass was also adjusted.

[0196] In addition, a platen heater and a blower fan are provided in the recording device Figure 4 as described. The wind speed of the blower fan is 2 m / s near the paper surface, and the wind temperature near the paper surface is 25°C. Settings and measurements were made in advance in a state where there is no temperature influence of the platen heater, and recording was performed under these set conditions.

[0197] The heating intensity of the platen heater was adjusted so that the surface temperature of the recording medium became the value in the table.

[0198] And for the recording medium (PET50A (transparent film), manufactured by Lintec), each ink composition was recorded with a specified coating amount and the number of passes according to the conditions of each description example, and solid images were recorded.

[0199] Thereafter, secondary drying was performed at 70°C using a secondary drying mechanism. Thus, a recorded object was obtained.

[0200] In addition, the number of passes recorded in Tables 2 to 3 refers to the number of times the inkjet head passes over a region when recording an arbitrary region. For example, when the distance the recording medium is moved by sub-scanning is 1 / 6 of the length of the nozzle array in the sub-scanning direction, the inkjet head passes over the region six times when recording an arbitrary region, and the ink composition is ejected each time.

[0201] As shown in Table 4, the recording device is set so that the control unit of the recording device executes two recording modes each. Each example of the recording device sequentially selects and executes the recording examples of the two recording modes.

[0202] In addition, the example of the recording device in Table 4 is just an example, and the control unit of the recording device only needs to be set to execute any two of the recording examples in each example of Tables 2 to 3.

[0203] 4. Evaluation

[0204] 4.1. Recording speed

[0205] The recording speed was evaluated according to the following evaluation criteria based on the number of passes required for recording an arbitrary part of the recording medium.

[0206] Evaluation criteria

[0207] S: 4 passes or less

[0208] A: 5 - 7 passes

[0209] B: 8 - 10 passes

[0210] C: 11 - 13 passes

[0211] D: 14 passes or more

[0212] 4.2. Visual recognition

[0213] The recording obtained in the above manner was placed on black paper, and the ease of visual confirmation of the image was visually observed, and the visual recognition was evaluated according to the following evaluation criteria. In addition, if the amount of white ink adhered is small, the concealment of the image is insufficient, the blackness of the black paper below can be seen through, and it is difficult to visually confirm.

[0214] Evaluation criteria

[0215] A: Easy to visually confirm.

[0216] B: Slightly observed to be blackened but easy to visually confirm

[0217] C: Observed to be blackened and slightly difficult to visually confirm

[0218] D: Observed to be blackened and difficult to visually confirm

[0219] 4.3. Color rendering

[0220] For the solid image of the recording obtained in the above manner, the OD value was measured using a colorimeter (i1Pro2, manufactured by X-rite) under the following measurement conditions, and the color rendering property was evaluated according to the following evaluation criteria.

[0221] Measurement conditions

[0222] D50 light source, state T, standard observer 2°, background: white paper

[0223] Evaluation criteria

[0224] S: OD value is 1.2 or more

[0225] A: OD value is 1.0 or more and less than 1.2

[0226] B: OD value is 0.8 or more and less than 1.0

[0227] C: OD value is 0.6 or more and less than 0.8

[0228] D: OD value is less than 0.6

[0229] 4.4. Shading unevenness

[0230] The pattern image of the recording obtained in the above manner was visually confirmed, and the density uniformity (shading unevenness) of the printed matter was evaluated according to the following evaluation criteria.

[0231] Evaluation criteria

[0232] S: A uniform image is obtained without shading unevenness

[0233] A: A good image is obtained without shading unevenness

[0234] B: An image without shading unevenness is obtained

[0235] C: Uneven shading unevenness can be visually confirmed

[0236] D: There is uneven shading unevenness and it is obvious

[0237] 4.5. Adhesion

[0238] For the recording obtained in the above manner, using a Gakushin type friction fastness tester (manufactured by TESTERSANGYO CO., LTD.), a cloth was placed on the surface of the coating film, and a load of 500 g was applied and reciprocally rubbed 50 times. The peeling and damage of the surface of the above coating film after rubbing were visually observed, and the adhesion was evaluated according to the following evaluation criteria.

[0239] Evaluation criteria

[0240] S: No peeling, almost no cloth transfer

[0241] A: No peeling, with fabric transfer printing

[0242] B: With peeling, peeling rate is 10 area% or less

[0243] C: With peeling, peeling rate is more than 10 area% and 50 area% or less

[0244] D: With peeling, peeling rate is more than 50 area%

[0245]

Table 4

[0246]

[0247] 5. Evaluation results

[0248] From the comparison between the examples and the comparative examples, it can be seen that any example having the first recording mode and the second recording mode can perform recording with excellent recording speed and recording with excellent image quality.

[0249] On the other hand, each of the comparative examples can only perform either recording with excellent recording speed or recording with excellent image quality.

[0250] For example, by performing the first recording mode, Example 1 can perform recording with excellent recording speed. In addition, by performing the second recording mode, it can perform recording with excellent visual recognition and color development.

[0251] It can be seen that the reference example only has a recording mode using only one of white ink and non-white ink, and has poor visual recognition or color development.

Claims

1. A recording device that performs recording on a recording medium, characterized in that the recording device includes: a white inkjet head that ejects a white ink composition containing a white pigment and adheres it to the recording medium; a non-white inkjet head that ejects a non-white ink composition containing a non-white pigment and adheres it to the recording medium; and a control unit that performs control to execute recording by performing multiple main scans, where the main scan refers to a scan in which while moving the relative position of the inkjet head with respect to the recording medium, an ink composition is ejected from the inkjet head and adhered to the recording medium, According to the control of the control unit, the recording device performs: recording based on a first recording mode, where the first recording mode refers to: through the same main scan, causing the white ink composition and the non-white ink composition to adhere to the same scan area of the recording medium, thereby forming a layer containing the white ink composition and the non-white ink composition; and recording based on a second recording mode, where the second recording mode refers to: through different main scans, causing the white ink composition and the non-white ink composition to adhere to the same scan area of the recording medium, thereby laminating and forming a layer containing the white ink composition and a layer containing the non-white ink composition, In the area of the recording medium to which the white ink composition and the non-white ink composition are adhered, in the area where the adhesion amount of the non-white ink composition is the largest, with respect to the adhesion amount of 100% by mass of the non-white ink composition, the ratio of the adhesion amount of the white ink composition is ratio A. When calculating this ratio A, ratio A1 of the first recording mode is less than ratio A2 of the second recording mode, or ratio A1 of the first recording mode is less than 80% by mass, or ratio A2 of the second recording mode is 80% by mass or more.

2. The recording device according to claim 1, characterized in that the content of the white pigment is 8.0% by mass or more with respect to the total amount of the white ink composition.

3. The recording device according to claim 1, characterized in that the white ink composition contains an organic solvent, the content of the organic solvent having a standard boiling point of less than 200°C in the total amount of the organic solvent is 50% by mass or more.

4. The recording device according to claim 1, characterized in that the white ink composition contains an organic solvent, the maximum value of the standard boiling point of the organic solvent is 250°C or less.

5. The recording device according to claim 1, characterized in that the white ink composition contains an organic solvent, the weighted average of the standard boiling point of the organic solvent is 200°C or less.

6. The recording device according to claim 1, characterized in that in the first recording mode, the same area is subjected to multiple main scans, where the main scan refers to a scan in which the white ink composition and the non-white ink composition are adhered to the scan area.

7. The recording device according to claim 1, characterized in that The white ink composition and the non-white ink composition are respectively an aqueous ink composition or a solvent-based ink composition.

8. The recording apparatus according to claim 1, wherein, the recording medium is a low-absorbency recording medium or a non-absorbency recording medium.

9. The recording apparatus according to claim 1, wherein, the recording medium is a non-white recording medium.

10. The recording apparatus according to any one of claims 1 to 9, wherein, in the first recording mode, a layer containing the white ink composition is formed by a main scan different from the main scan for forming a layer containing the white ink composition and the non-white ink composition, and the layer containing the white ink composition and the non-white ink composition and the layer containing the white ink composition are laminated.

11. A recording method, wherein, using the recording apparatus according to any one of claims 1 to 10, either the first recording mode or the second recording mode is selected, and recording is performed by the selected recording mode.

Images