Recording method and recording device

Abstract

To provide a recording method which can manufacture a recorded article having excellent image quality.SOLUTION: A recording method for performing recording on a recording medium using a first ink composition and a second ink composition includes a background image formation step of discharging the second ink composition from an inkjet head, attaching the second ink composition onto the recording medium, and forming a background image, and a main image formation step of discharging the first ink composition from the inkjet head, attaching the first ink composition to the background image while overlapping the background image, and forming a main image, wherein first ink composition is an aqueous ink composition containing a first colorant, the second ink composition is an aqueous ink composition containing a second colorant and a silicone-based surface active agent, the main image has a first main image region and a second main image region, the background image has a first background image region overlapping the first main image region and a second background image region overlapping the second main image region, and an attachment amount B1 per unit area of the second ink composition in the first background image region is smaller than an attachment amount B2 per unit area of the second ink composition in the second background image region.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Recording methods using inkjet heads are capable of recording high-resolution images with relatively simple equipment and have been rapidly developing in various fields. For example, various studies have been conducted to improve image quality when recording on non-absorbent recording media. For example, Patent Document 1 discloses an ink set that includes a reaction liquid containing an aggregating agent, a first ink containing a colorant, and a second ink containing a colorant, and is used for recording on non-absorbent or low-absorbent recording media, in which the reaction liquid, the first ink, and the second ink are applied to the recording media in this order in layers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-071738 Summary of the Invention [Problem to be solved by the invention]

[0004] The ink set described in Patent Document 1 is used in a recording method in which a first ink is applied to a recording medium, and then a second ink is applied to the area on the recording medium where the first ink has been applied. In this type of recording method, it has been found that there is room for improvement in image quality in areas where there is a large amount of the first ink and the second ink. [Means for solving the problem]

[0005] The present invention provides a recording method for use on a recording medium using a first ink composition and a second ink composition, the recording method comprising: a background image forming step of ejecting the second ink composition from an inkjet head and depositing it on the recording medium to form a background image; and a main image forming step of ejecting the first ink composition from an inkjet head and depositing it on top of the background image to form a main image, wherein the first ink composition is an aqueous ink composition containing a first colorant, the second ink composition is an aqueous ink composition containing a second colorant and a silicone surfactant, the main image has a first main image region and a second main image region, and the background image has a first background image region overlapping the first main image region and a second background image region overlapping the second main image region, and a deposition amount B1 of the second ink composition per unit area in the first background image region is smaller than a deposition amount B2 of the second ink composition per unit area in the second background image region. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 2 is a schematic diagram of a recording apparatus used in the present embodiment. [Figure 2] FIG. 10 is a flowchart illustrating a procedure for processing main image data in a control unit. [Figure 3] 1 is a table showing the results of examples. [Figure 4] 1 is a table showing the results of examples. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings as necessary, but the present invention is not limited to this, and various modifications are possible without departing from the spirit of the present invention. In the drawings, the same elements are given the same reference numerals, and redundant explanations will be omitted. Furthermore, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

[0008] 1. Recording device The recording apparatus of this embodiment performs the recording method of this embodiment, which will be described later. The recording apparatus includes an inkjet head that ejects a second ink composition onto a recording medium to form a background image, an inkjet head that ejects a first ink composition onto a recording medium to deposit the second ink composition onto the background image to form a main image, and a control unit that controls the amount of the first ink composition ejected by the inkjet head and the amount of the second ink composition ejected by the inkjet head. The first ink composition is an aqueous ink composition containing a first colorant, and the second ink composition is an aqueous ink composition containing a second colorant and a silicone surfactant. The main image has a first main image region and a second main image region. The background image has a first background image region overlapping the first main image region and a second background image region overlapping the second main image region. The control unit controls the amount of adhesion B1 of the second ink composition per unit area in the first background image region to be less than the amount of adhesion B2 of the second ink composition per unit area in the second background image region. The unit area is not particularly limited, and may be, for example, one pixel or one inch. 2 It may also be possible to use the following.

[0009] As an example of an inkjet device, a serial printer is shown in a perspective view in Fig. 1. As shown in Fig. 1, the serial printer 20 includes a control unit 210, a conveying unit 220, a recording unit 230, and a drying mechanism 240.

[0010] The control unit 210 can control the overall operation of the serial printer 20. For example, the control unit 210 can control the amount of the first ink composition ejected and the amount of the second ink composition ejected by the recording unit 230. Furthermore, in the background image forming step described below, the control unit 210 can control the amount of adhesion B1 per unit area of ​​the second ink composition in the first background image region so that it is less than the amount of adhesion B2 per unit area of ​​the second ink composition in the second background image region.

[0011] More specifically, the control unit 210 determines, based on the acquired main image data, a first main image region having a relatively large amount of the first ink composition deposited therein and a second main image region having a relatively small amount of the first ink composition deposited therein, depending on the amount of the first ink composition deposited therein to form the main image. Then, the ejection amount may be controlled to perform recording so that the amount B1 of the second ink composition deposited in the first background image region corresponding to the first main image region is smaller than the amount B2 of the second ink composition deposited in the second background image region corresponding to the second main image region.

[0012] Note that this embodiment aims to ensure hiding power while adjusting the ink amount by controlling the amount of the second ink composition deposited in the background image region according to the amount of the first ink composition deposited in the main image region, and from that perspective, the main image region and background image region are defined as at least two regions according to the amount of deposition, but the main image region is not limited to one having a first main image region and a second main image region, and the background image region is not limited to one having a first background image region and a second background image region. That is, this embodiment also includes embodiments in which the main image region is divided into three, four, or more stages according to the amount of deposition of the first ink composition, and each stage is defined as a first main image region, a second main image region, a third main image region, a fourth main image region, etc. Correspondingly, the background image does not have to be limited to two regions, the first background image region and the second background image region, but may be defined as a first background image region, a second background image region, a third background image region, a fourth background image region, etc.

[0013] The conveying unit 220 conveys the recording medium F fed to the serial printer to the recording unit 230, and ejects the recording medium after recording to the outside of the serial printer. Specifically, the conveying unit 220 has a paper feed roller and conveys the fed recording medium F in the sub-scanning direction T2.

[0014] The recording unit 230 also includes an inkjet head 231, a carriage 234 that carries the inkjet head 231 having nozzles that eject an ink composition onto the recording medium F sent from the conveying unit 220, and a carriage moving mechanism 235 that moves the carriage 234 in the main scanning directions S1 and S2 of the recording medium F.

[0015] The inkjet head 231 ejects the first ink composition and the second ink composition. There may be multiple inkjet heads 231, or there may be only one. The inkjet head 231 ejecting the first ink composition and the inkjet head 231 ejecting the second ink composition may be the same or different. The inkjet head 231 ejecting the first ink composition is also referred to as the first inkjet head 231A, and the inkjet head 231 ejecting the second ink composition is also referred to as the second inkjet head 231B. The first inkjet head 231A and the second inkjet head 231B may be the same or different.

[0016] The installation position of the drying mechanism 240 is not particularly limited as long as it is located in a position where it can heat the recording medium F. In the example of FIG. 1, the drying mechanism 240 is installed as a platen heater in a position facing the inkjet head 231. When the drying mechanism 240 is installed in a position facing the inkjet head 231, it is possible to reliably dry the recording medium F to which the ink composition has adhered. This allows the platen heater to be used in the drying process of the background image and the main image.

[0017] Other drying mechanisms 240 include, for example, a print heater mechanism that heats the recording medium F by contacting it with a heat source, a heating mechanism that heats the background image or main image on the recording medium F, such as a mechanism that irradiates infrared rays or microwaves, which are electromagnetic waves with a maximum wavelength at around 2450 MHz, and an air blowing mechanism that blows air onto the background image or main image on the recording medium F, such as a dryer mechanism that blows warm air or room temperature air.

[0018] In the case of a serial printer, an inkjet head 231 having a length smaller than the width of the recording medium is provided, and the head moves to perform recording in multiple passes. In a serial printer, the head 231 is mounted on a carriage 234 that moves in a predetermined direction, and the head moves in conjunction with the movement of the carriage, thereby ejecting the ink composition onto the recording medium F. In this way, recording is performed in two or more passes. A pass is also called a main scan. A sub-scan is performed to transport the recording medium between passes. In other words, main scans and sub-scans are performed alternately.

[0019] Furthermore, while the recording device of this embodiment has been described above with reference to Figure 1 using a serial printer as an example, the recording device of this embodiment may also be a line printer. In a line printer, a line head is fixed and the recording medium is moved in the sub-scanning direction (the longitudinal direction of the recording medium, the transport direction), and ink droplets are ejected from the nozzle openings of the head in conjunction with this movement to record an image on the recording medium. Generally, in a line printer, the head is fixed and does not move, and recording is performed in one pass (single pass), which gives line printers an advantage over serial printers in terms of faster recording speed.

[0020] In this case, the second inkjet head 231B is positioned upstream in the conveyance direction of the recording medium, and the first inkjet head 231A is positioned relatively downstream, so that the second inkjet head 231B forms a background image, and the first inkjet head 231A forms a main image on the background image.

[0021] Furthermore, the drying mechanism for drying the background image may be, for example, a platen heater facing the second inkjet head 231B, or may be a blowing mechanism or a heating mechanism located near the second inkjet head 231B or between the first inkjet head 231A and the second inkjet head 231B.

[0022] Furthermore, the drying mechanism for drying the main image may be, for example, a platen heater facing the first inkjet head 231A, or may be an air blowing mechanism or a heating mechanism located near the first inkjet head 231A or downstream of it in the conveying direction of the recording medium.

[0023] 2. Recording method The recording method of this embodiment (hereinafter simply referred to as the “recording method”) is a recording method performed on a recording medium such as a non-absorbent recording medium using a first ink composition and a second ink composition, the recording method comprising: a background image forming step of ejecting the second ink composition from an inkjet head and depositing it on the recording medium to form a background image; and a main image forming step of ejecting the first ink composition from an inkjet head and depositing it on top of the background image to form a main image, wherein the first ink composition is an aqueous ink composition containing a first colorant, the second ink composition is an aqueous ink composition containing a second colorant and a silicone surfactant, the main image has a first main image region and a second main image region, the background image has a first background image region overlapping the first main image region and a second background image region overlapping the second main image region, and a deposition amount B1 of the second ink composition per unit area in the first background image region is smaller than a deposition amount B2 of the second ink composition per unit area in the second background image region.

[0024] When printing on a recording medium, such as a non-absorbent recording medium like a transparent film or a colored film, a background image serving as a base is formed using white ink, and then the desired image is printed on top of the background image using color inks. By forming a background image, it is possible to conceal the color of the recording medium, improving the accuracy of color expression in the desired image and improving the image quality. In other words, the concealment ability of the recording medium is improved, and the image quality of the resulting image is improved. Furthermore, by forming the desired image on the background image, the colors in the image are more vividly expressed, improving the image quality. In other words, the vividness of the colors is improved, and the image quality of the resulting image is improved.

[0025] In the above printing, in order to shorten the printing time, the desired image may be formed before the background image is completely dried. In this case, the color inks tend to aggregate in areas of the image where the color ink density is high, which can lead to uneven bleeding. Furthermore, because the background image is not completely dried, the color inks tend to be slow to dry in areas of high color ink density, which can lead to the white ink and color inks used in the background image mixing together, resulting in a decrease in color vividness. In other words, the color development is likely to be reduced.

[0026] By completely drying the background image before forming the desired image, problems related to uneven bleeding and color development can be improved. However, completely drying the background image increases the time required for printing, which is undesirable. Furthermore, extending the drying time or increasing the drying temperature can cause problems such as clogging of the inkjet head.

[0027] It is also possible to form a desired image using color inks on a recording medium such as a non-absorbent recording medium without forming a background image. However, if a background image is not formed, it becomes difficult to conceal the color of the recording medium, and the image quality of the desired image tends to deteriorate.

[0028] Therefore, in the recording method of this embodiment, the desired main image is divided into multiple regions, and a background image is formed by varying the amount of white ink ejected for each region. The main image is then formed before the background image is completely dry. With this recording method, even if the main image is formed before the background image is completely dry, bleeding unevenness and deterioration of color development are unlikely to occur. In other words, by performing printing using the recording method of this embodiment, it is possible to achieve the improvement in image quality achieved by forming the background image and the reduction in printing time achieved by forming the main image before the background image is completely dry, while also suppressing the occurrence of bleeding unevenness and deterioration of color development.

[0029] Like white ink, the color inks used in forming the main image can conceal the color of the recording medium. That is, in areas of the main image where the color ink density is high, the color of the recording medium can be concealed even if the amount of white ink used in forming the background image is small. Furthermore, in areas of the main image where the color ink density is high, the color of the main image is vividly expressed in those areas even if the amount of white ink used in forming the background image is small. Therefore, even if a background image is formed by reducing the amount of white ink ejected in areas of the main image where the color ink density is high compared to the amount of white ink ejected in other areas of the main image, the concealment of the recording medium can be ensured and the color can be vividly expressed in those areas. Furthermore, by forming a background image in those areas by reducing the amount of white ink ejected, the background image dries more quickly. Furthermore, even if an image is formed in those areas before the background image is completely dry, the white ink dries in a relatively short drying time due to the small amount of white ink ejected. As a result, the color inks are less likely to aggregate and the color inks dry more easily, making it less likely for the color inks and the white ink to mix. Therefore, it is believed that the recording method of this embodiment can improve image quality and reduce printing time while suppressing uneven bleeding and reduced color development, but the factors behind this are not limited to those mentioned above.

[0030] The amount of white ink used to form the background image in areas of the main image where the color ink density is low is greater than the amount of white ink used in areas of the main image where the color ink density is high. By increasing the amount of white ink ejected in areas of low color ink density to form the background image, the concealment ability of the recording medium is improved and the colors of the main image can be expressed vividly. Furthermore, because the color ink density is low in these areas, even if the background image is formed by increasing the amount of white ink ejected and the main image is formed before the background image has completely dried, bleeding unevenness and deterioration in color development are unlikely to occur.

[0031] Each step of the recording method of this embodiment will be described in detail below.

[0032] 2.1. Main image identification process First, the recording method of this embodiment may include a main image identification step of identifying a first main image region and a second main image region in the main image based on the main image data for forming the main image, before forming the background image and the main image. Specifically, in the main image identification step, the control unit 210 processes the main image data to identify the first main image region and the second main image region. Figure 2 is a flow diagram illustrating the main image data processing procedure in the control unit 210.

[0033] First, main image data (hereinafter also referred to as "main image data") is prepared as YCC data consisting of a luminance signal and two color difference signals, such as JPEG. After reading the main image data, the control unit 210, in step s101, refers to a lookup table and converts it into main image print data, which is CMYK data in which each area of ​​the main image data is represented by cyan, magenta, yellow, and black. Furthermore, in step s102, the control unit 210 converts the main image print data into main image dot data, which is data related to ink droplets in each pixel, through halftone processing. Specifically, the main image dot data defines the amount of the first ink composition of each color to be ejected in each pixel.

[0034] In step s103, the control unit 210 determines the first main image region and the second main image region based on the main image dot data. In this way, the control unit 210 executes the main image specification step. When executing step s103, the control unit 210 may determine the region where the ejection amount per unit area of ​​the first ink composition is greater than a specific value as the first main image region, and the region where the ejection amount per unit area is less than the specific value as the second main image region. Alternatively, the control unit 210 may determine the region where a character image is recorded as the second main image region, and the region other than the second main image region as the first main image region. Alternatively, the user may select the first main image region and the second main image region.

[0035] 2.2. Background image identification process The recording method of this embodiment may include a background image identification step of identifying a first background image area and a second background image area based on the first main image area and the second main image area identified in the main image identification step. Hereinafter, the background image identification step will be described based on FIG. 2.

[0036] The control unit 210 ensures that the deposition amount B1 per unit area of the second ink composition in the first background image area overlapping the first main image area and the deposition amount B2 per unit area of the second ink composition in the second background image area overlapping the second main image area satisfy B1 < B2. In this way, in step s104, the control unit 210 generates background image printing data in which each area of the background image is defined by the deposition amount per unit area of the second ink composition. Further, in step s105, the control unit 210 converts the background image printing data into background image dot data, which is data regarding ink droplets at each pixel by halftone processing. Specifically, in the dot data, the discharge amount of the second ink composition at each pixel is defined. In this way, the control unit 210 executes the background image identification step. After the main image identification step and the background image identification step, the control unit 210 causes the conveyance unit 220 and the recording unit 230 to execute the background image formation step and the main image formation step based on the main image dot data obtained in the main image identification step and the background image dot data obtained in the background image identification step.

[0037] The method for ensuring B1 < B2 is not particularly limited. For example, the discharge amount of the second ink composition at each pixel may be changed, or the pixels to which the second ink composition is attached may be thinned out.

[0038] The control unit 210 may set the deposition amount B1 per unit area of the second ink composition in the first background image area according to the deposition amount M1 per unit area of the first ink composition in the first main image area, and set the deposition amount B2 per unit area of the second ink composition in the second background image area according to the deposition amount M2 per unit area of the first ink composition in the second main image area.

[0039] The control unit 210 may execute the main image determination step and the background image determination step so that the adhesion amount M1 of the first ink composition per unit area in the first main image region, the adhesion amount M2 in the second main image region, and the adhesion amounts B1 and B2 are such that M1+B1 and M2+B2 are equal to or greater than certain values. In other words, the control unit 210 may set the adhesion amounts B1 and B2 according to the adhesion amounts M1 and M2 so that M1+B1 and M2+B2 are equal to or greater than certain values. This tends to further improve the concealment ability of the recording medium F.

[0040] 2.3. Background image formation process The recording method of this embodiment includes a background image forming step in which the second ink composition described below is ejected from an inkjet head and deposited on a recording medium such as a non-absorbent recording medium to form a background image. By forming a background image, the recording medium obtained by the recording method of this embodiment has improved concealment properties and improved color vividness, which tends to result in improved image quality. The background image is preferably a solid white image.

[0041] The background image has a first background image region that overlaps with a first main image region (described below), and a second background image region that overlaps with a second main image region (described below). In the background image forming process, the amount of second ink composition deposited per unit area in the first background image region (B1) is less than the amount of second ink composition deposited per unit area in the second background image region (B2). By dividing the background image into two regions and forming background images with optimal amounts of second ink composition deposited per unit area for each region, it is possible to achieve the above-mentioned improvement in image quality, shorten printing time, and suppress uneven bleeding and deterioration in color development.

[0042] The coating amount B1 is preferably 6.0 mg / inch 2 Over 16.0mg / inch 2 less than 8.0 mg / inch 2 More than 15.5mg / inch 2 less than 10.0 mg / inch 2 Over 15.0mg / inch 2or less, 11.0 mg / inch 2 More than 14.5mg / inch 2 The following is the result.

[0043] The coating amount B2 is preferably 10.0 mg / inch 2 Super 30.0mg / inch 2 Less than 12.5 mg / inch 2 Over 28.0mg / inch 2 or less, 14.0 mg / inch 2 Over 26.0mg / inch 2 or less, 14.5 mg / inch 2 Over 24.0mg / inch 2 The following is the result.

[0044] Furthermore, the ratio (B1 / B2) of the adhesion amount B1 to the adhesion amount B2 is preferably 0.5 to 0.9, 0.6 to 0.9, or 0.7 to 0.9.

[0045] In the background image forming process, the recording medium is preferably placed on a platen having suction holes for adsorbing the recording medium. Having suction holes in the platen for adsorbing the recording medium prevents the recording medium from floating off the platen during the background image forming process, which tends to result in improved image quality. However, when a recording medium placed on a platen having suction holes for adsorbing the recording medium is heated by the platen, the portion of the recording medium facing the suction holes is insufficiently heated, resulting in insufficient drying of that portion. If the first ink composition adheres to an insufficiently dried area of ​​the background image during the main image forming process, uneven bleeding and reduced color development tend to occur.

[0046] On the other hand, by performing printing using the recording method of this embodiment, bleeding unevenness and deterioration of color development can be suppressed. Therefore, when the recording medium is placed on a platen having suction holes for adsorbing the recording medium and the recording method of this embodiment is performed, bleeding unevenness and deterioration of color development can be suppressed, and the recording medium can be prevented from floating from the platen during the background image formation process, which tends to improve the image quality of the recorded product.

[0047] In the background image forming step, the background image is preferably formed by scanning the ink jet head to eject the second ink composition while moving the relative positions of the ink jet head and the recording medium.

[0048] In the background image forming step, the background image is formed by repeating a main scan in which the inkjet head ejects the second ink composition from the inkjet head while moving the inkjet head in the width direction relative to the recording medium, and a sub-scan in which the recording medium is moved in a direction intersecting the width direction relative to the inkjet head, and the background image is formed by performing the main scan in which the inkjet head ejects the second ink composition onto a main scanning region of the recording medium that the inkjet head faces by the main scan two or more times, and the ejection amount V of the second ink composition per unit area in the main scanning region is L is preferably smaller than the ejection amount V1 of the second ink composition per unit area in the first main scan. In this case, the movement distance of each sub-scan is shorter than the length of the inkjet head in the sub-scanning direction. This can prevent the unintended occurrence of areas on the recording medium where the second ink composition is not deposited.

[0049] When a background image is formed by multiple main scans in the background image forming process, the time from the last main scan to the start of the main image forming process (described later) is shorter than the time from the first main scan to the start of the main image forming process. In other words, the area onto which the second ink composition is ejected in the last main scan is the area of ​​the background image that has not yet dried when the ejection of the first ink composition begins in the main image forming process. In this area, the first ink composition and the second ink composition tend to mix easily, which reduces color development. Therefore, the ejection volume V L By reducing the discharge volume V L This tends to improve the drying properties of the area onto which the second ink composition is ejected, and as a result, improve color development.

[0050] From the same viewpoint, the ejection amount V of the second ink composition per unit area during the n-th main scan n (n is an integer of 1 or more) is the ejection amount V of the second ink composition per unit area during the (n+1)th main scan. n+1 It is preferable that V1>V2>V3>...>V L It is preferable that:

[0051] 2.4.Drying process The recording method of this embodiment may include a drying step of drying the background image. By including the drying step in the recording method of this embodiment, the background image onto which the first ink composition is ejected in the main image forming step is more likely to dry. As a result, in the main image forming step, it is possible to prevent the first ink composition and the second ink composition from mixing and thereby reducing color development.

[0052] In the drying step, the background image may be completely dried or insufficiently dried, but from the viewpoint of shortening the printing time, it is preferable to dry the background image insufficiently. In the recorded matter obtained by the recording method of this embodiment, even if the background image is insufficiently dried, the vividness of the color is improved, and as a result, the image quality tends to be improved.

[0053] When a drying process is performed, the drying process is performed after the background image forming process and before the main image forming process. Furthermore, when a drying process is performed, the drying process preferably includes an air blowing process of blowing air onto the background image or a heating process of heating the background image. In the drying process, both the air blowing process and the heating process may be performed, or only one of them may be performed. When both the air blowing process and the heating process are performed in the drying process, both processes may be performed simultaneously, or one of the processes may be performed after the other process is completed.

[0054] The air blowing step may be performed by a hot air heater, a blower without a heating function, etc. The heating step may be performed by a platen heater, a hot air heater, an IR heater, etc.

[0055] The time for which the drying process is performed is not particularly limited, but as described above, the background image may not be sufficiently dried, so for example, while the background image forming process is being performed, the drying process may be performed simultaneously by heating with a platen heater, and the main image forming process may be performed immediately after the background image forming process is completed.

[0056] When the drying step includes a heating step, the heating temperature in the heating step is preferably 30 to 75°C, 35 to 70°C, or 40 to 65°C. A higher heating temperature is preferable because it accelerates the drying of the background image, but if the heating temperature is too high, the recording medium may shrink or melt, causing adverse effects on the recording medium. On the other hand, by keeping the heating temperature in the heating step within the above range, it is possible to accelerate the drying of the background image while suppressing adverse effects on the recording medium.

[0057] 2.5. Main image forming process The recording method of this embodiment includes a main image forming step in which a first ink composition is ejected from an inkjet head and adhered to a background image so as to overlap the background image, thereby forming a main image. By ejecting the first ink composition from an inkjet head and adhering it to a background image so as to overlap the background image, the recording medium obtained by the recording method of this embodiment has improved concealment and color vividness, which tends to result in improved image quality. If the recording method of this embodiment includes the drying step described above, the main image is adhered to the dried background image so as to overlap the background image. Furthermore, in this embodiment, the main image refers to the desired image intended to be recorded on the recording medium. For example, when printing a photograph, the image that appears in the photograph is the main image.

[0058] The main image has a first main image region and a second main image region. The first main image region overlaps a first background image region, and the second main image region overlaps a second background image region. Here, the amount of deposition of the first ink composition per unit area M1 in the first main image region is greater than the amount of deposition of the first ink composition per unit area M2 in the second main image region.

[0059] The coating amount M1 is preferably 5.0 mg / inch 2 Over 15.0mg / inch 2 Less than 5.5 mg / inch 2 Over 14.0mg / inch 2 less than 6.0 mg / inch 2 Over 13.0mg / inch 2 The following is the result.

[0060] The coating amount M2 is preferably 5.0 mg / inch 2 Less than 0 mg / inch 2 Super 5.0mg / inch 2 Less than 0.1 mg / inch 2 More than 4.8mg / inch 2 Less than 0.2 mg / inch 2 More than 4.6mg / inch 2 Less than 0.4 mg / inch 2More than 4.4mg / inch 2 Less than 0.5 mg / inch 2 More than 4.2mg / inch 2 Less than 0.5 mg / inch 2 More than 4.0mg / inch 2 The following is the result.

[0061] The ratio (M1 / M2) of the deposition amount M1 to the deposition amount M2 is preferably 1.2 to 3.0, 1.3 to 2.8, 1.4 to 2.6, or 1.6 to 2.4.

[0062] The first main image area and the second main image area may also be distinguished by the type of image to be recorded. Specifically, the area in which a character image is recorded may be the second main image area, and the area other than the area in which the character image is recorded may be the first main image area. The area in which a character image is recorded is not particularly limited, and may be, for example, a rectangular area that exactly covers the entire character. Alternatively, if multiple character images are recorded in a row to form a sentence, the area in which the character image is recorded may be a rectangular area that exactly covers all the entire character. Alternatively, only the area in which the lines that make up the characters are printed may be the area in which the character image is recorded.

[0063] In the main image forming step, the main image is preferably formed by scanning the ink jet head to eject the first ink composition while moving the relative positions of the ink jet head and the recording medium.

[0064] The sum of the deposition amount M1 and the deposition amount B1 is preferably 10 mg / inch 2 More than 14mg / inch 2 More than 18mg / inch 2 or more, 16 to 30 mg / inch 2 and 18 to 30 mg / inch 2When the total of the adhesion amount M1 and the adhesion amount B1 is within the above range, the concealing property of the recording medium tends to be further improved. In addition, the total of the adhesion amount M2 and the adhesion amount B2 is preferably 16 mg / inch. 2 More than 17mg / inch 2 More than 18mg / inch 2 or more, 16 to 30 mg / inch 2 and 17 to 30 mg / inch 2 and 18 to 30 mg / inch 2 When the total of the adhesion amount M2 and the adhesion amount B2 is within the above range, the hiding power of the recording medium tends to be further improved.

[0065] 2.6. Post-drying process The recording method of this embodiment may include a post-drying step for drying the background image and main image formed on the recording medium after the background image forming step and main image forming step. The post-drying step may be performed using the same method as the drying step described above. The time for performing the post-drying step is not particularly limited as long as it can sufficiently dry the background image and main image formed on the recording medium, but it may be performed for, for example, 1 minute. Furthermore, if the post-drying step includes a heating step, the heating temperature in the heating step is not particularly limited, but is, for example, 30 to 75°C.

[0066] 3. Ink composition The recording method of this embodiment uses a first ink composition and a second ink composition, each of which will be described in detail below.

[0067] 3.1. First ink composition The first ink composition of this embodiment is a water-based ink composition used in the main image forming process, and contains a first coloring material. Each component of the first ink composition will be described in detail below.

[0068] 3.1.1. First coloring agent The first coloring agent may be a colored coloring agent other than a white coloring agent. However, in the main image forming process, a white coloring agent may also be used in addition to the colored coloring agents to form the main image. In this embodiment, the white coloring agent refers to a white coloring agent used in ink having a whiteness of 70% to 100% as measured in accordance with JIS Z8715:1999.

[0069] Examples of coloring agents include dyes and pigments, and it is preferable to use pigments. Examples of pigments include, but are not limited to, inorganic and organic pigments. Examples of inorganic pigments include, but are not limited to, carbon blacks such as furnace black, lamp black, acetylene black, and channel black, iron oxide, and titanium oxide. Examples of organic pigments include azo pigments such as insoluble azo pigments, condensed azo pigments, azo lakes, and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, and polycyclic pigments such as quinophthalone pigments, dye chelates, dye lakes, nitro pigments, nitroso pigments, aniline black, and daylight fluorescent pigments. Pigments may be used alone or in combination of two or more.

[0070] The carbon black is not particularly limited, and examples thereof include No. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, No. 2200B, etc. (all manufactured by Mitsubishi Chemical Corporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. (all manufactured by Carbon Columbia), Rega1 400R, Rega1 330R, Rega1 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. (manufactured by Cabot Corporation). Examples of such inks include Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A, and Special Black 4 (all manufactured by Degussa).

[0071] The white pigment is not particularly limited, but examples thereof include CI Pigment White 6, 18, and 21, and titanium oxides such as titanium dioxide.

[0072] The yellow pigment is not particularly limited, but examples thereof include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 167, 172, and 180.

[0073] The magenta pigment is not particularly limited, and examples thereof include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48(Ca), 48(Mn), 57(Ca), 57:1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, and 245, and CI Pigment Violet. Examples include 19, 23, 32, 33, 36, 38, 43, and 50.

[0074] Examples of cyan pigments include, but are not limited to, CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25, 60, 65, and 66, and CI Vat Blue 4 and 60.

[0075] Furthermore, pigments other than magenta, cyan, and yellow are not particularly limited, but examples thereof include CI Pigment Green 7, 10, CI Pigment Brown 3, 5, 25, 26, and CI Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, and 63.

[0076] The content of the coloring material is preferably 1.0 to 15.0% by mass, and more preferably 2.0 to 10.0% by mass, relative to the total amount of the first ink composition.

[0077] Dispersants The first ink composition of this embodiment may contain a dispersant for dispersing the pigment. The dispersant for dispersing the pigment is not particularly limited, and examples include those primarily composed of one or more of polyoxyalkylene polyalkylene polyamines, vinyl polymers and copolymers, acrylic polymers and copolymers, polyesters, polyamides, polyimides, polyurethanes, amino polymers, silicon-containing polymers, sulfur-containing polymers, fluorine-containing polymers, styrene-acrylic resins, and epoxy resins. Commercially available dispersants include the Ajisper series manufactured by Ajinomoto Fine-Techno Co., Ltd., the Solsperse series (e.g., Solsperse 36000 (acid value 45) and Solsperse 32000 (amine value 35)) available from Avecia Co., Ltd., the Disperbyk series (e.g., Disperbyk 168 and 180) manufactured by BYK Chemie, and the Disparlon series manufactured by Kusumoto Chemicals Co., Ltd. The dispersants may be used alone or in combination.

[0078] The content of the dispersant relative to the total amount of the first ink composition is not particularly limited, but is, for example, 0.1 to 3.0% by mass.

[0079] 3.1.2. Fixing resin The first ink composition of this embodiment may contain a fixing resin, which tends to improve the abrasion resistance of the recorded matter.

[0080] The fixing resin may be a resin particle or a resin emulsion, in which the resin particles are contained in the ink in a dispersed form, or a resin particle dissolved in the solvent component of the ink in a dissolved form.

[0081] The fixing resin is not particularly limited, but examples thereof include resin particles made of urethane resin, acrylic resin (including styrene-acrylic resin), fluorene resin, polyolefin resin, rosin-modified resin, terpene resin, polyester resin, polyamide resin, epoxy resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, ethylene vinyl acetate resin, etc. The fixing resin may be used alone or in combination of two or more.

[0082] Among these, urethane resins, acrylic resins, and polyolefin resins are preferred. These resin particles are often handled in the form of an emulsion, but may also be in the form of a powder.

[0083] Urethane resin is a general term for resins having urethane bonds. In addition to urethane bonds, the urethane resin may be a polyether urethane resin containing ether bonds in the main chain, a polyester urethane resin containing ester bonds in the main chain, or a polycarbonate urethane resin containing carbonate bonds in the main chain.

[0084] Acrylic resin is a general term for polymers obtained by polymerizing at least an acrylic monomer such as (meth)acrylic acid or a (meth)acrylic acid ester as one component. Examples include resins obtained from acrylic monomers and copolymers of acrylic monomers with other monomers. Examples include acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers. Another example of a vinyl monomer is styrene. Other usable acrylic monomers include acrylamide and acrylonitrile.

[0085] Among these, styrene-acrylic resins are preferred. Examples of styrene-acrylic resins include, but are not limited to, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, styrene-α-methylstyrene-acrylic acid copolymers, and styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymers. Use of such resins tends to further improve the image quality and abrasion resistance of the resulting recorded matter.

[0086] The polyolefin resin has an olefin such as ethylene, propylene, or butylene in its structural skeleton, and any known polyolefin resin can be appropriately selected and used.

[0087] The content of the fixing resin relative to the total amount of the first ink composition is preferably 1.0 to 15.0 mass %, 2.5 to 10.0 mass %, or 3.0 to 7.5 mass %.

[0088] Wax The first ink composition of this embodiment may contain a wax. The wax is not particularly limited, but examples include plant- or animal-based waxes such as carnauba wax, candelilla wax, beeswax, rice wax, and lanolin; mineral waxes such as montan wax and ozokerite; so-called petroleum-based waxes such as paraffin wax; synthetic waxes such as carbon wax, Hoechst wax, polyolefin wax, polyethylene wax, silicone wax, and stearic acid amide; and natural or synthetic wax emulsions or blended waxes such as α-olefin-maleic anhydride copolymers. The wax may be used alone or in combination of two or more types.

[0089] The content of the wax is preferably 0.1 to 5.0% by mass, and more preferably 0.5 to 2.5% by mass, relative to the total amount of the first ink composition.

[0090] 3.1.4. Organic Solvents The first ink composition of this embodiment may contain an organic solvent. The organic solvent is not particularly limited, but examples thereof include monohydric alcohols, polyols, and glycol ethers. The organic solvent may be used alone or in combination of two or more.

[0091] The monohydric alcohols are not particularly limited, but examples thereof include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and 2-methyl-2-propanol.

[0092] The polyols are not particularly limited, but examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene 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, and glycerin.

[0093] The glycol ethers are not particularly limited, but examples thereof include triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol monobutyl ether, diethylene glycol monobutyl ether, and dipropylene glycol monopropyl ether.

[0094] The content of the organic solvent relative to the total amount of the first ink composition is not particularly limited, but is, for example, 15.0 to 35.0 mass %, 17.5 to 32.5 mass %, or 20.0 to 30.0 mass %.

[0095] Surfactants The first ink composition of this embodiment may contain a surfactant. Examples of surfactants include, but are not limited to, acetylene glycol surfactants, fluorine-based surfactants, and silicone-based surfactants. These surfactants may be used alone or in combination. Examples of silicone-based surfactants include, but are not limited to, BYK-UV3500, BYK350, and BYK-348 (trade names manufactured by BYK Japan). Examples of acetylene glycol-based surfactants include, but are not limited to, Olfine E1010 (trade name manufactured by Nissin Chemical Industry Co., Ltd.) and Surfynol 465 (trade name manufactured by Nissin Chemical Industry Co., Ltd.). Examples of fluorine-based surfactants include, but are not limited to, FS-300 (manufactured by DuPont) and Fluorad-FC4430 (manufactured by Sumitomo 3M Limited).

[0096] The content of the surfactant relative to the total amount of the first ink composition is not particularly limited, but may be, for example, 0.1 to 2.0% by mass.

[0097] 3.1.6.Water The water contained in the first ink composition of this embodiment is not particularly limited, but examples include ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, and pure water.

[0098] The content of water is preferably 50 to 80% by mass, and more preferably 55 to 75% by mass, based on the total amount of the first ink composition.

[0099] 3.2. Second ink composition The second ink composition of this embodiment is a water-based ink composition used in the background image forming process, and contains a second coloring agent and a silicone surfactant. Each component of the first ink composition will be described in detail below.

[0100] 3.2.1. Second colorant The second coloring agent is preferably a white coloring agent. When the second ink composition is a second white ink composition containing a white coloring agent, it becomes possible to conceal the color of the recording medium, and the color development of the color of the main image tends to be improved. However, if necessary, the second coloring agent may be a coloring agent other than a white coloring agent. Even if the second coloring agent is a coloring agent other than a white coloring agent, it becomes possible to conceal the color of the recording medium, and the color development of the color of the main image tends to be improved.

[0101] The second coloring agent may be any of the coloring agents exemplified as the first coloring agent in the first ink composition. The content of the second coloring agent is preferably 5.0 to 20.0% by mass, and more preferably 7.5 to 15.0% by mass, relative to the total amount of the second ink composition.

[0102] Dispersants The second ink composition of this embodiment may contain a dispersant to disperse the pigment. The type and content of the dispersant contained in the second ink composition are the same as those described for the first ink composition.

[0103] 3.2.2. Fixing resin The second ink composition of this embodiment may contain a fixing resin. The inclusion of a fixing resin tends to improve the abrasion resistance of recorded matter. The type of fixing resin contained in the second ink composition is the same as that described for the first ink composition. The content of the fixing resin relative to the total amount of the second ink composition is preferably 1 to 10.0 mass %, 2 to 7.5 mass %, or 3 to 6 mass %.

[0104] Wax The second ink composition of this embodiment may contain a wax. The type and content of the wax contained in the second ink composition are the same as those described for the first ink composition.

[0105] 3.2.4. Organic Solvents The second ink composition of this embodiment may contain an organic solvent. The type and content of the organic solvent contained in the second ink composition are the same as those described for the first ink composition.

[0106] Surfactants The second ink composition of this embodiment contains a silicone-based surfactant. The inclusion of a silicone-based surfactant in the second ink composition tends to improve the image quality of recorded material. On the other hand, the inclusion of a silicone-based surfactant in the second ink composition makes it easier for the color inks used to form a main image on a background image to move, making it more likely that adjacent color ink droplets will mix, resulting in bleeding irregularities. According to the recording method of this embodiment, even if the second ink composition contains a silicone-based surfactant, the occurrence of such bleeding irregularities can be suppressed.

[0107] The silicone surfactant is not particularly limited, and examples thereof include BYK-UV3500, BYK350, and BYK-348 (trade names manufactured by BYK Japan KK). Furthermore, if necessary, the second ink composition may contain a surfactant other than a silicone surfactant. The surfactant other than a silicone surfactant is not particularly limited, and examples thereof include acetylene glycol surfactants, and examples of acetylene glycol surfactants include Olfine E1010 (trade name manufactured by Nissin Chemical Industry Co., Ltd.). The surfactant may be used alone, or two or more types may be used in combination.

[0108] 3.2.6.Water The water contained in the first ink composition of this embodiment is not particularly limited, but examples include ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, and pure water.

[0109] The content of water is preferably 50 to 80% by mass, and more preferably 55 to 75% by mass, based on the total amount of the first ink composition.

[0110] 4. Method for producing ink composition The method for producing the ink composition of this embodiment is not particularly limited, but may involve, for example, mixing the above-described components. Alternatively, a colorant dispersion liquid may be prepared by dispersing a colorant and a dispersant in a solvent, and the resulting colorant dispersion liquid may be mixed with the other above-described components.

[0111] 5. Recording Media The recording medium used in the recording method of this embodiment is not particularly limited, but is preferably a transparent recording medium or a recording medium that is colored other than white. Examples include absorbent recording media, low absorbent recording media, and non-absorbent recording media. Among these, non-absorbent recording media are preferred. Examples of absorbent recording media include, but are not limited to, plain paper such as electrophotographic paper that has high ink permeability, inkjet paper (paper specifically for inkjet printers that has an ink absorbing layer made of silica particles or alumina particles, or an ink absorbing layer made of a hydrophilic polymer such as polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP)), kraft paper used in the packaging field, and paper coated with a barrier coating agent. The low-absorbency recording medium is not particularly limited, but examples thereof include art paper, coated paper, cast paper, and one-side glossy paper that are used in general offset printing and have relatively low ink permeability. Non-absorbent recording media are not particularly limited, but examples include plastic films and plates such as polyvinyl chloride, polyethylene, polypropylene, biaxially oriented polypropylene, polyethylene terephthalate (PET), biaxially oriented polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, etc.; metal plates such as iron, silver, copper, aluminum, etc.; or metal plates and plastic films manufactured by vapor deposition of these various metals, and alloy plates such as stainless steel and brass; recording media in which a plastic film such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate, polystyrene, polyurethane, etc. is bonded (coated) to a paper substrate, and films that have heat-sealing properties to the above recording media, such as films laminated with uniaxially oriented polypropylene (CPP) or very low density polyethylene (LLDPE). [Example]

[0112] The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited to the following examples. Unless otherwise specified, the experiments in the examples and comparative examples were carried out at room temperature (25°C) and 1 atmosphere.

[0113] 1. Preparation of the first ink composition and the second ink composition The first and second ink compositions used in each example were obtained by placing each component in a stainless steel mixing tank so as to obtain the composition shown in Figure 3, mixing and stirring at room temperature, and removing impurities and foreign matter by filtration or other means as necessary. The numerical values ​​for each component shown in each example in the figure represent mass % unless otherwise specified. The mass % of the colorant, fixing resin, and wax represent the solids concentration. The components in the table are as follows: PB15:3: Pigment Blue 15:3 Styrene acrylic resin: BASF, product name JONCRYL 537J Polyethylene wax: BYK, product name AQUACER 539 BYK348: BYK, silicone surfactant Olfine E1010: Nissin Chemical Industry Co., Ltd., acetylene glycol surfactant

[0114] 2. Recording method [Example 1] The recording medium used was PET50A (product name, manufactured by Lintec Corporation), a substrate for adhesive labels with a transparent film as the surface substrate. A modified Seiko Epson L-4733AW was used as the recording device. The recording medium was placed on a platen with suction holes for adsorbing the recording medium. The recording device had a control unit, which was capable of executing a main image identification process for identifying first and second main image regions in the main image based on main image data for forming the main image, and a background image identification process for identifying first and second background image regions based on the first and second main image regions identified in the main image identification process.

[0115] Image data including a high-duty area (first main image area) and a low-duty area (second main image area) was prepared, and recording was performed together with processing in the control unit of the recording device. First, a background image was formed using the second ink composition. At this time, the signal intensity was set to 80% in the first background image area overlapping the first main image area. Specifically, the amount of deposition of the second ink composition was 14.4 mg / inch. 2 In addition, in the second background image area overlapping the second main image area, the signal intensity was set to 100%. Specifically, the amount of the second ink composition applied was set to 18 mg / inch. 2 The first main image area is an area where the signal intensity is 90%, specifically, an area where the amount of the first ink composition applied is 7 mg / inch. 2 The second main image area was an area where the signal intensity was 50%, specifically, an area where the amount of the first ink composition applied was 4 mg / inch 2 The resolution of both the background image and the main image was set to 720 x 720 dpi.

[0116] For non-white images, signal intensity is a value expressed as a percentage of 255 (100%) of YMCK data (0 to 255), and is data per unit area of ​​image data. For example, a signal intensity of 80% can be achieved by setting the ink ejection volume to 80% without changing the ink ejection density, or by setting the ink ejection density to 80% without changing the ink ejection volume. In this embodiment, the latter method was used. Since cyan ink is used in this example, the signal data is C data. By inputting this to the halftone module, dot-on or -off data is output. If the dot is on, an ink droplet is deposited on the pixel. For white images, the value is expressed as a percentage of W data (0 to 255). Note that, because non-white ink compositions and white ink compositions differ in halftone module and ink weight per ink droplet, the ink deposition amount will not be the same even if the value is the same.

[0117] When forming the background image, the platen temperature was set to 45°C to dry the background image. After the formation of the background image was completed, the main image was formed. When the formation of the main image began, the background image was not completely dry. After the formation of the main image was completed, the recording medium on which the background image and main image had been formed was heated to 75°C to completely dry the background image and main image. In this way, the recorded matter of Example 1 was obtained.

[0118] [Examples 2 to 7, Comparative Examples 1 and 2] Printing was carried out in the same manner as in Example 1, except that printing was carried out under the printing conditions shown in Figures 3 and 4, to obtain recorded matters of Examples 2 to 7 and Comparative Examples 1 and 2. In the examples with and without signal processing of the background image, the deposition amount of the second ink composition was 18 mg / inch 2 In the example with and without signal processing of the background image, the amount of the second ink composition applied is 18 mg / inch 2 Reduced from.

[0119] 3. Evaluation Method 3.1.Image Quality The recorded materials obtained in the examples and comparative examples were visually observed from the side on which the main image was formed, and evaluated based on the following evaluation criteria. [Evaluation criteria] A: There is no unevenness in the shading of the main image, and there is no ink pooling at the edges of the main image. B: There is no unevenness in the shading of the main image, but there is some ink accumulation on the edges of the main image. C: The main image has uneven density and there are ink pools on the edges of the main image.

[0120] 3.2. Concealment The recorded materials obtained in the examples and comparative examples were visually observed from the side on which the main image was formed, and evaluated based on the following evaluation criteria. [Evaluation criteria] A: When looking at a fluorescent light 3m away through the recording, the light from the fluorescent light is not visible. B: When looking at a fluorescent light 3m away through the recording, the light from the fluorescent light is slightly visible. C: When looking at a fluorescent light 3m away through the recording, the light from the fluorescent light is clearly visible. [Explanation of symbols]

[0121] 20... serial printer, 210... control unit, 220... conveying unit, 230... recording unit, 231... inkjet head, 234... carriage, 235... carriage moving mechanism, 240... drying mechanism, F... recording medium, S1, S2... main scanning direction, T2... sub-scanning direction

Claims

1. A recording method for recording on a recording medium using a first ink composition and a second ink composition, a background image forming step of ejecting the second ink composition from an inkjet head and depositing it on the recording medium to form a background image; a main image forming step of ejecting the first ink composition from an inkjet head to deposit the first ink composition on the background image, thereby forming a main image; the first ink composition is a water-based ink composition containing a first coloring material, the second ink composition is a water-based ink composition containing a second colorant and a silicone-based surfactant; the main image has a first main image area and a second main image area; the background image has a first background image area overlapping the first main image area and a second background image area overlapping the second main image area; The amount B of the second ink composition deposited per unit area in the first background image region 1 is the amount of the second ink composition deposited per unit area in the second background image region B 2 Less, recording methods.

2. Said adhesion amount B 2 The adhesion amount B 1 The ratio (B 1 / B 2 ) is 0.5 to 0.9; The recording method according to claim 1 .

3. The amount M of the first ink composition deposited per unit area in the first main image region 1 is the amount of adhesion M of the first ink composition per unit area in the second main image region. 2 More than The recording method according to claim 1 .

4. Said adhesion amount M 1 is 5.0 mg / inch 2 Over 15.0 mg / inch 2 is as follows: Said adhesion amount M 2 is 5.0 mg / inch 2 is less than The recording method according to claim 3 .

5. the second main image area is an area in which a character image is recorded, and the first main image area is an area other than the area in which the character image is recorded; The recording method according to claim 1 .

6. a drying step of drying the background image, In the main image forming step, the main image is formed on the dried background image. The recording method according to claim 1 .

7. the drying step includes either an air blowing step of blowing air onto the background image or a heating step of heating the background image. The recording method according to claim 6.

8. In the background image forming step, the recording medium is placed on a platen having suction holes for adsorbing the recording medium. The recording method according to claim 1 .

9. in the background image forming step, the background image is formed by a scanning operation in which the second ink composition is ejected from the inkjet head while moving a relative position between the inkjet head and the recording medium, In the main image forming step, the main image is formed by a scanning operation in which the first ink composition is ejected from the inkjet head while moving a relative position between the inkjet head and the recording medium. The recording method according to claim 1 .

10. in the background image forming step, the background image is formed by repeating a main scan in which the inkjet head is moved in a width direction relative to the recording medium while ejecting the second ink composition from the inkjet head, and a sub scan in which the recording medium is moved in a direction intersecting the width direction relative to the inkjet head, and the background image is formed by performing the main scanning twice or more times to eject the second ink composition from the inkjet head onto a main scanning region of the recording medium that the inkjet head faces during the main scanning; In the main scanning region, the ejection amount V of the second ink composition per unit area in the final main scanning L is the ejection amount V of the second ink composition per unit area during the first main scanning pass. 1 is smaller than The recording method according to claim 9.

11. a main image specifying step of specifying the first main image region and the second main image region in the main image based on main image data for forming the main image; a background image specifying step of specifying the first background image area and the second background image area based on the specified first main image area and the specified second main image area, In the background image forming step, the background image is formed based on the identified first background image area and the identified second background image area; In the main image forming step, the main image is formed based on the identified first main image area and second main image area. The recording method according to claim 1 .

12. In the background image specifying step, The amount M of the first ink composition deposited per unit area in the first main image region 1 The deposition amount B of the second ink composition per unit area in the first background image region is determined according to 1 Set The amount M of the first ink composition deposited per unit area in the second main image region 2 The deposition amount B of the second ink composition per unit area in the second background image region is determined according to 2 Set The recording method according to claim 11.

13. A recording apparatus for performing the recording method according to any one of claims 1 to 12, an inkjet head that ejects the second ink composition and deposits it on the recording medium to form the background image; the inkjet head that ejects the first ink composition and deposits it on the background image to form the main image; a control unit that controls the amount of the first ink composition ejected from the inkjet head and the amount of the second ink composition ejected from the inkjet head, the first ink composition is a water-based ink composition containing a first coloring material, the second ink composition is a water-based ink composition containing a second colorant and a silicone-based surfactant; the main image has a first main image area and a second main image area; the background image has a first background image area overlapping the first main image area and a second background image area overlapping the second main image area; The control unit determines the amount of adhesion B of the second ink composition per unit area in the first background image region. 1 is the adhesion amount B of the second ink composition per unit area in the second background image region. 2 Control to be less, Recording device.

Images