Inkjet recording method and inkjet recording apparatus

Abstract

To provide an inkjet recording method and an inkjet recording device which enable recording that is excellent in continuous printing stability while enabling discharge using a common driving signal in a plurality of nozzle arrays of different colors of ink to be discharged.SOLUTION: An inkjet recording method includes a step of discharging black ink containing C.I. Reactive Black 39 from a first liquid jet head, and a step of discharging cyan ink containing C.I. Reactive Blue 72 from the first liquid jet head, in which the first liquid jet head has a first nozzle array and a second nozzle array that are adjacent to each other, discharges the black ink from the first nozzle array, and discharges the cyan ink from the second nozzle array.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Patent Document 1 discloses a so-called double-type inkjet recording head in which two nozzle rows are arranged in parallel. Each nozzle row has a plurality of nozzles aligned at regular intervals. Each nozzle is provided with a cavity portion and a piezoelectric element. An ink composition is supplied from an ink supply mechanism to fill the cavity portion.

[0003] When a drive signal is applied from the head driver to the piezoelectric element, the volume of the cavity changes and the ink composition is ejected from the nozzle, thereby making it possible to perform recording on the recording medium. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-203801 A Summary of the Invention [Problem to be solved by the invention]

[0005] By configuring the inkjet recording head so that a common drive signal is applied to the piezoelectric elements installed in one of the two nozzle rows and to the piezoelectric elements installed in the other, the circuit configuration of the drive circuit in the head driver can be simplified.

[0006] On the other hand, in an inkjet recording head that uses inks of multiple colors, inks of different colors may be ejected from two nozzle rows. In this case, the inks of different colors have different physical properties because the types and amounts of coloring materials contained are different. As a result, even if the same drive signal is applied to the piezoelectric element, the ink ejection behavior differs between the two nozzle rows. As a result, it becomes difficult to achieve continuous printing stability in both nozzle rows, and there is a problem that the continuous printing stability decreases in one of the nozzle rows. [Means for solving the problem]

[0007] The inkjet recording method according to an embodiment of the present invention comprises the steps of: A step of ejecting a black ink containing CI Reactive Black 39 from a first liquid ejection head; ejecting a cyan ink containing CI Reactive Blue 72 from the first liquid ejection head; Contains CIReactive Orange 13 ejecting orange ink from a second liquid jet head; Contains CIReactive Yellow 95 ejecting yellow ink from the second liquid jet head; having The first liquid jet head includes: a first nozzle row and a second nozzle row adjacent to each other; The black ink is ejected from the first nozzle row, The cyan ink is ejected from the second nozzle row, The second liquid jet head is a third nozzle row and a fourth nozzle row adjacent to each other, The orange ink is ejected from the third nozzle row, The yellow ink is ejected from the fourth nozzle row. The inkjet recording method according to an embodiment of the present invention comprises the steps of: A step of ejecting a black ink containing CI Reactive Black 39 from a first liquid ejection head; ejecting a cyan ink containing CI Reactive Blue 72 from the first liquid ejection head; ejecting orange ink from a second liquid jet head; ejecting yellow ink from the second liquid jet head; ejecting a gray ink containing CI Reactive Blue 49 and CI Reactive Black 39 from a third liquid ejection head different from the first liquid ejection head and the second liquid ejection head; having The first liquid jet head includes: a first nozzle row and a second nozzle row adjacent to each other; The black ink is ejected from the first nozzle row, The cyan ink is ejected from the second nozzle row, The second liquid jet head is a third nozzle row and a fourth nozzle row adjacent to each other, The orange ink is ejected from the third nozzle row, the yellow ink is ejected from the fourth nozzle row.

[0008] An inkjet recording apparatus according to an embodiment of the present invention includes: a first liquid ejection head having a first nozzle row and a second nozzle row adjacent to each other, and a second liquid ejection head having a third nozzle row and a fourth nozzle row adjacent to each other; The first liquid jet head includes: A black ink containing CIReactive Black 39 is ejected from the first nozzle row, A cyan ink containing CI Reactive Blue 72 is ejected from the second nozzle row, The second liquid jet head is From the third nozzle row Contains CIReactive Orange 13 Orange ink is ejected, From the fourth nozzle row Contains CIReactive Yellow 95 Yellow ink is ejected. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating a printer as an inkjet recording apparatus according to an embodiment. [Diagram 2] 2 is a plan view showing a schematic positional relationship between a support base, a liquid ejecting head, and a maintenance mechanism included in the printer shown in FIG. 1. [Diagram 3] FIG. 2 is a plan view of the liquid jet head shown in FIG. [Figure 4] FIG. 3 is a perspective view of the maintenance unit shown in FIG. 2. [Diagram 5] 4 is a flowchart illustrating an inkjet recording method according to an embodiment. [Figure 6] 3 is a table showing examples of combinations of ink colors supplied to the nozzle rows of the four liquid ejection heads shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an inkjet recording method and an inkjet recording apparatus according to the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings.

[0011] Fig. 1 is a schematic diagram showing a printer as an inkjet recording apparatus according to an embodiment. Fig. 2 is a plan view showing a schematic positional relationship between a support base, a liquid jet head, and a maintenance mechanism included in the printer shown in Fig. 1. Fig. 3 is a plan view of the liquid jet head shown in Fig. 1.

[0012] In each drawing of the present application, the X-axis, Y-axis, and Z-axis are set as three mutually orthogonal axes. Each axis is represented by an arrow, with the tip end side being "plus" and the base end side being "minus." In the following explanation, the plus side of the Z-axis is explained as "up" and the minus side of the Z-axis is explained as "down."

[0013] 1. Inkjet recording device First, an inkjet recording apparatus according to an embodiment will be described.

[0014] 1 is an inkjet recording device that includes a support base 12, a transport unit 14, a printing unit 15, a printer body 16, and a cover 17. The support base 12, the transport unit 14, and the printing unit 15 are assembled into the printer body 16, which is composed of a housing, a frame, etc. The cover 17 is attached to the printer body 16 in an openable and closable manner.

[0015] The support table 12 extends in the width direction of the recording medium 13, that is, in the X-axis direction in Fig. 1. The transport unit 14 transports the recording medium 13 supported by the support table 12 in the Y-axis direction, which is the transport direction, along the surface of the support table 12. The printing unit 15 prints by ejecting ink onto the recording medium 13 being transported.

[0016] The transport unit 14 also includes transport roller pairs 18 and 19 and a guide plate 20. The transport roller pair 18 is disposed upstream of the support table 12 in the transport direction of the recording medium 13, and the transport roller pair 19 is disposed downstream. The guide plate 20 is disposed downstream of the transport roller pair 19 in the transport direction, and supports and guides the recording medium 13. The transport roller pairs 18 and 19 are driven by a transport motor (not shown) to rotate while holding the recording medium 13 therebetween. As a result, the transport unit 14 transports the recording medium 13 in the Y-axis direction along the surface of the support table 12 and the surface of the guide plate 20.

[0017] The printing unit 15 includes guide shafts 22 and 23 extending along the X-axis direction, and a carriage 25 that can reciprocate in the X-axis direction while being guided by the guide shafts 22 and 23. The carriage 25 includes a carriage base 25B and a carriage body 25A. The carriage base 25B reciprocates in the X-axis direction as the carriage motor 24 shown in FIG. 2 is driven. The carriage body 25A slides along the Z-axis direction relative to the carriage base 25B so that the distance between the carriage body 25A and the support stand 12 changes. That is, the carriage body 25A can move in the Z-axis direction relative to the carriage base 25B by a movement mechanism 28 formed of a cam or the like.

[0018] At least one liquid ejection head 60 is attached to the carriage body 25A. In this embodiment, four liquid ejection heads 60 are attached. In FIG. 2, the four liquid ejection heads 60 are arranged at a constant pitch in the X-axis direction. Each liquid ejection head 60 has the nozzles 26 shown in FIG. 1 that are capable of ejecting ink. Each liquid ejection head 60 is supported by the carriage body 25A such that its lower surface faces the support base 12 at a predetermined interval in the Z-axis direction, and reciprocates in the X-axis direction together with the carriage 25 as the carriage motor 24 is driven.

[0019] A part of the supply mechanism 31 is attached to the carriage 25. The supply mechanism 31 supplies ink from the ink cartridge 30 to the liquid ejection head 60. Specifically, the supply mechanism 31 causes the ink to flow along a supply direction A from the ink cartridge 30 side (upstream side) toward the liquid ejection head 60 side (downstream side). At least one pair of ink cartridges 30 and supply mechanisms 31 is provided for each type of ink. In this embodiment, eight colors of ink are used, so eight pairs of ink cartridges 30 and supply mechanisms 31 are provided. Note that the number of colors of ink that the printer 11 has is not particularly limited as long as it is two or more colors.

[0020] The eight ink cartridges 30 each contain a different color ink, and are each removably mounted in the mounting portion 32. Color printing and the like is performed on the recording medium 13 by ejecting the ink supplied from each ink cartridge 30 from the liquid ejection head 60.

[0021] Each supply mechanism 31 has a supply path 33 that supplies ink from the ink cartridge 30 to the liquid jet head 60. In the supply path 33, there are provided, in order from the upstream side along the supply direction A, a supply pump 34 that causes the ink to flow, a filter unit 35 that captures air bubbles and foreign matter in the ink, a static mixer 36 that changes the flow of ink in the supply path 33 to agitate the ink, a liquid storage chamber 37 that stores the ink, and a pressure adjustment unit 38 that adjusts the pressure of the ink.

[0022] The supply pump 34 has a diaphragm pump 40 with a variable volume pump chamber, a suction valve 41 arranged upstream of the diaphragm pump 40, and a discharge valve 42 arranged downstream of the diaphragm pump 40. The suction valve 41 and the discharge valve 42 are configured as one-way valves that allow ink to flow downstream while restricting ink flow upstream.

[0023] Therefore, the supply pump 34 sucks ink from the ink cartridge 30 side via the suction valve 41 as the volume of the pump chamber of the diaphragm pump 40 increases, and discharges ink via the discharge valve 42 to the liquid ejection head 60 as the volume of the pump chamber decreases. The filter unit 35 is disposed at a position corresponding to the cover 17 of the printer body 16, and is detachably attached to the supply path 33. The filter unit 35 can be replaced by opening the cover 17.

[0024] In the printer 11, while the carriage 25 is moving in the X-axis direction, printing is performed on the recording medium 13 by alternating between a printing operation in which ink is ejected from each nozzle 26 of the liquid ejection head 60 to record one scan on the recording medium 13, and a transport operation in which the recording medium 13 is transported to the next printing position.

[0025] The printer 11 includes a control unit 39 that controls the printing operation and the transport operation. The control unit 39 controls the driving of a transport motor (not shown) that drives the transport roller pairs 18 and 19, the carriage motor 24, the supply pump 34, and the like, and controls the ejection of ink from each nozzle 26 of the liquid ejection head 60. The liquid ejection head 60 ejects the supplied ink from each nozzle 26 onto the recording medium 13 while reciprocating in the X-axis direction together with the carriage 25 as the carriage motor 24 is driven. The control unit 39 also operates the movement mechanism 28 to move the carriage main body 25A up and down, for example, according to the thickness of the recording medium 13.

[0026] The recording medium 13 is not particularly limited, and examples thereof include various types of paper, various types of films, various types of fabrics, etc. The material constituting the fabric is not particularly limited, and examples thereof include natural fibers such as cotton, linen, wool, and silk, synthetic fibers such as polypropylene, polyester, acetate, triacetate, polyamide, and polyurethane, and biodegradable fibers such as polylactic acid, and may be blended fibers of these. The fabric may be any of the above-mentioned fibers in the form of woven fabric, knitted fabric, nonwoven fabric, etc.

[0027] As shown in Fig. 2, a maintenance mechanism 43 is provided at a position adjacent to one end of the support base 12 in the X-axis direction. The maintenance mechanism 43 performs maintenance of the liquid ejecting head 60. In this embodiment, the area in which the recording medium 13 is transported is the transport area PA shown in Fig. 2. The maintenance mechanism 43 is disposed within the scanning area of ​​the carriage 25 in the X-axis direction and outside the transport area PA. In Fig. 2, the maintenance mechanism 43 is disposed on the right side of the transport area PA.

[0028] When printing is not being performed, when the power is off, etc., the carriage 25 and the liquid ejection head 60 wait at a home position HP where a maintenance mechanism 43 is disposed. The liquid ejection head 60 is movable in the X-axis direction between the transport area PA and the home position HP.

[0029] The maintenance mechanism 43 includes a flushing unit 45 and a cleaning mechanism 47, which are arranged in order from the position closest to the transport area PA in the X-axis direction.

[0030] The flushing unit 45 has a liquid receiving portion 44. The liquid receiving portion 44 receives ink ejected from the nozzles 26. Such a flushing unit 45 receives ink ejected from each nozzle 26 regardless of printing, for the purpose of preventing or eliminating clogging of each nozzle 26. This enables flushing. In addition, the cleaning mechanism 47 performs a cleaning operation on the liquid ejection head 60.

[0031] The cleaning mechanism 47 includes a unit holder 75 and four maintenance units 50 attached to the unit holder 75. Each maintenance unit 50 faces and maintains the liquid ejection head 60 waiting at the home position HP. The cleaning mechanism 47 also includes a pair of guide frames 73 that guide the unit holder 75 to move in the Y-axis direction, and a holder drive unit 70 that reciprocates the unit holder 75 in the Y-axis direction. The guide frames 73 and the holder drive unit 70 are each assembled to the printer body 16.

[0032] 2 includes an electric motor 71 serving as a power source, and a belt 72. A unit holder 75 is fixed to the belt 72, and the belt 72 rotates as the electric motor 71 is driven to rotate. The unit holder 75 is guided by guide frames 73 on both sides in the X-axis direction, and reciprocates in the Y-axis direction as the belt 72 rotates. The drive of the electric motor 71 is controlled by the control unit 39.

[0033] The four maintenance units 50 are guided by at least one of both side walls in the X-axis direction and both side walls in the Y-axis direction of the unit holder 75, and move integrally with one another so that the distance between them and the opposing liquid ejection heads 60 changes.

[0034] As shown in FIG. 1, the liquid ejecting head 60 includes a bracket portion 61 for mounting to the carriage 25, and a head main body portion 62 that protrudes downward from the bracket portion 61.

[0035] 3, a plate-shaped cover member 63 having four through holes 66A, 66B, 66C, and 66D is fixed to the head main body 62 by a fixing structure such as a lock on the lower surface of the head main body 62. Two nozzle rows 64 are exposed in each of the four through holes 66A, 66B, 66C, and 66D. Each nozzle row 64 is a collection of nozzles 26 arranged at a constant pitch. The number of nozzle rows 64 is not limited to two, and may be three or more.

[0036] In this embodiment, the through holes 66A and the through holes 66B are aligned in this order from the positive side to the negative side of the Y axis. The nozzle row 64 exposed in the through holes 66A and the nozzle row 64 exposed in the through holes 66B are aligned in a line along the Y axis.

[0037] In this embodiment, the through holes 66C and the through holes 66D are aligned in this order from the positive side to the negative side of the Y axis. The nozzle row 64 exposed in the through holes 66C and the nozzle row 64 exposed in the through holes 66D are aligned in a line along the Y axis.

[0038] Furthermore, through holes 66A, 66B and through holes 66C, 66D are disposed at a predetermined interval in the X-axis direction. Furthermore, through hole 66B is disposed at a midpoint between through holes 66C and 66D in the Y-axis direction. Similarly, through hole 66C is disposed at a midpoint between through holes 66A and 66B in the Y-axis direction.

[0039] The entire lower surface of the liquid ejection head 60 as described above is the target for wiping by the maintenance unit 50.

[0040] 3, the nozzle rows 64 are composed of a large number of nozzles 26 arranged at a constant pitch along the Y axis. Each nozzle row 64 ejects one color of ink corresponding to the ink color of the ink cartridge 30. Among the multiple nozzle rows 64, there may be unused nozzle rows from which ink is not ejected.

[0041] The four maintenance units 50 have the same configuration. Fig. 4 is a perspective view of the maintenance unit 50 shown in Fig. 2. The maintenance unit 50 shown in Fig. 4 includes a unit frame 51 in the shape of a bottomed box having an opening 52 on the top surface. An absorbing member 55 capable of absorbing ink and a wiping member 54 capable of wiping the liquid ejection head 60 are housed in the unit frame 51 so as to be adjacent to each other in the Y-axis direction. The opening 52 is configured so that, when the liquid ejection head 60 faces the maintenance unit 50, the head main body 62 is housed in the opening 52 when viewed from the Z-axis direction.

[0042] 4 is provided in caps 56A, 56B, 56C, and 56D provided in the unit frame 51. The caps 56A, 56B, 56C, and 56D have a cylindrical side wall with an oval upper surface. The caps 56A, 56B, 56C, and 56D are fixed in the unit frame 51 by the fixing plate 53 such that the through holes 66A, 66B, 66C, and 66D are located in the cylindrical side wall when the liquid ejection head 60 faces the maintenance unit 50.

[0043] 4 is provided at two locations, one on the positive side of the Y axis of cap 56A and one on the positive side of the Y axis of cap 56C. The wiping member 54 is made of a thin rubber member, and this rubber member is an elastic member having a lower ink absorption capacity than the absorbing member 55.

[0044] Next, the maintenance operation of the liquid ejection head 60 by the maintenance unit 50 will be described. This maintenance operation is controlled by the control unit 39, and a contact operation and a wiping operation are performed here. The maintenance unit 50 performs the maintenance operation for the through holes 66A and 66B and at the same time the maintenance operation for the through holes 66C and 66D. Therefore, in the following description, the maintenance operation performed for the through holes 66A and 66B will be described as an example.

[0045] First, the contact operation will be described. The carriage motor 24 is driven to move the carriage 25 in the X-axis direction, so that the liquid ejection head 60 faces the maintenance unit 50. From this state, the liquid ejection head 60 is lowered by the movement mechanism 28, and the maintenance unit 50 is raised by a drive unit (not shown).

[0046] Next, the pressure of the ink supplied to the liquid ejection head 60 is adjusted to be high by the pressure adjustment unit 38, causing the ink to swell from the nozzles 26. In the contact operation, the absorbing member 55 is brought into contact with the ink swelled from the liquid ejection head 60.

[0047] Next, the wiping operation will be described. The ink bulging from the nozzle 26 due to the contact operation described above is absorbed by the absorbing member 55, but there may be residual ink that is not absorbed and remains around the nozzle 26. Therefore, as a maintenance operation, a wiping operation is performed after the contact operation to wipe away the residual ink.

[0048] In the wiping operation, the direction from the positive side of the Y axis to the negative side of the Y axis is set as the wiping direction, and the maintenance unit 50 is moved in this wiping direction. This movement of the maintenance unit 50 causes the wiping member 54 provided in the maintenance unit 50 to wipe the lower surface of the liquid ejection head 60. This wiping operation removes residual ink adhering to the periphery of the nozzles 26 of the nozzle row 64 from the periphery of the nozzles 26.

[0049] Following the wiping operation, a flushing operation may be performed in which ink is forcibly ejected from the nozzles 26, regardless of printing.

[0050] In the flushing operation, ink is ejected from each nozzle 26 of the liquid ejection head 60 toward the absorbing member 55 in a state in which the liquid ejection head 60 faces the maintenance unit 50 .

[0051] After the flushing operation is completed, the liquid ejection head 60 is raised by the moving mechanism 28, and the maintenance unit 50 is lowered by a drive unit (not shown), and they each return to the positions before the start of the contact operation. This completes the maintenance operation of the liquid ejection head 60 by the maintenance unit 50.

[0052] 2. Inkjet recording method Next, an inkjet recording method according to an embodiment will be described.

[0053] Fig. 5 is a flowchart for explaining the ink jet recording method according to the embodiment. Fig. 6 is a table showing examples of combinations of ink colors supplied to the nozzle rows of the four liquid jet heads 60 shown in Fig. 2.

[0054] As shown in Fig. 6, in this embodiment, two of the eight colors of ink are supplied to each liquid jet head 60. In Fig. 6, the four liquid jet heads 60 are liquid jet heads 60A, 60B, 60C, and 60D. In each liquid jet head 60, as shown in Fig. 3, two nozzle rows 64 are exposed from four through holes 66A, 66B, 66C, and 66D.

[0055] From the two nozzle rows 64, ink of a different color is ejected for each nozzle row 64. This color combination is the same for all four through holes 66A, 66B, 66C, and 66D. Therefore, ink of two colors is ejected from the liquid ejection head 60. As a result, ink of a total of eight colors is ejected from the four liquid ejection heads 60.

[0056] FIG. 6 shows eight colors of ink assigned to four liquid jet heads 60A, 60B, 60C, and 60D. FIG. 6 shows four through holes 66A, 66B, 66C, and 66D provided in each liquid jet head 60, and two nozzle rows 64 exposed therethrough. In FIG. 6, of the two nozzle rows 64 provided in each of the liquid jet heads 60A, 60B, 60C, and 60D, the one located on the negative side of the X axis is referred to as a "nozzle row 641," and the one located on the positive side of the X axis is referred to as a "nozzle row 642." In the following description, the liquid jet head 60A is referred to as a "first liquid jet head," the liquid jet head 60D is referred to as a "second liquid jet head," and the liquid jet head 60B is referred to as a "third liquid jet head."

[0057] As shown in FIG. 6, black ink (Bk) is assigned to the nozzle row 641 of the liquid ejecting head 60A (first liquid ejecting head), and cyan ink (Cy) is assigned to the nozzle row 642.

[0058] As shown in FIG. 6, red ink (Re) is assigned to the nozzle row 641 of the liquid jet head 60B (third liquid jet head), and gray ink (Gr) is assigned to the nozzle row 642.

[0059] As shown in FIG. 6, blue ink (Bu) is assigned to the nozzle row 641 of the liquid ejecting head 60C, and magenta ink (Ma) is assigned to the nozzle row 642.

[0060] As shown in FIG. 6, orange ink (Or) is assigned to the nozzle row 641 of the liquid jet head 60D (second liquid jet head), and yellow ink (Ye) is assigned to the nozzle row 642.

[0061] In the inkjet recording method according to this embodiment, recording is performed on the recording medium 13 using the four liquid jet heads 60A, 60B, 60C, and 60D to which the eight colors of ink are assigned.

[0062] Furthermore, in each liquid ejection head 60, a common drive signal is used for ejecting ink from the nozzle row 641 and a common drive signal is used for ejecting ink from the nozzle row 642. Therefore, the same drive signal generated from the same drive waveform generating circuit can be used for ejecting ink from the nozzle row 641 and the nozzle row 642. This allows the circuit configuration of the drive signal supply circuit included in the control unit 39 to be simplified.

[0063] The inkjet recording method shown in Fig. 5 includes a black ink ejection step S102, a cyan ink ejection step S104, a red ink ejection step S106, a gray ink ejection step S108, a blue ink ejection step S110, a magenta ink ejection step S112, an orange ink ejection step S114, and a yellow ink ejection step S116. Note that the order of the black ink ejection step S102 to the yellow ink ejection step S116 shown in Fig. 5 is not limited to the order shown in the figure, and the steps may be reversed, or multiple steps may be performed simultaneously.

[0064] 2.1. Black ink ejection process and cyan ink ejection process In the black ink ejection process S102, black ink is ejected from the nozzle row 641 (first nozzle row) of the liquid ejection head 60A (first liquid ejection head). In the cyan ink ejection process S104, cyan ink is ejected from the nozzle row 642 (second nozzle row) of the liquid ejection head 60A. The nozzle rows 641 and 642 are adjacent to each other in the liquid ejection head 60A. Furthermore, the black ink ejected from the nozzle row 641 contains CI Reactive Black 39 as a dye. Furthermore, the cyan ink ejected from the nozzle row 642 contains CI Reactive Blue 72 as a dye.

[0065] The black ink and the cyan ink containing the dyes of the optimized combination as described above have a small difference in ejection behavior. Therefore, when the black ink is ejected from the nozzle row 641 and the cyan ink is ejected from the nozzle row 642 based on the same drive signal, it is possible to match the waveform of the drive signal to both inks. As a result, even when the same drive signal is used, both inks can be ejected with optimal behavior, and continuous printing stability can be improved for both inks. That is, according to this embodiment, it is possible to realize an inkjet recording method that enables ejection using a common drive signal from the two nozzle rows 641 and 642 that eject inks of different colors, while enabling recording with excellent continuous printing stability.

[0066] On the other hand, when fabric is used as the recording medium 13, the above black ink and cyan ink enable image formation with excellent dye adhesion and color development.

[0067] Furthermore, the printer 11, which is an inkjet recording apparatus according to this embodiment, includes a liquid ejection head 60A (first liquid ejection head) having a nozzle row 641 (first nozzle row) and a nozzle row 642 (second nozzle row) adjacent to each other. The liquid ejection head 60A is configured to eject black ink containing CIReactive Black 39 from the nozzle row 641, and to eject cyan ink containing CIReactive Blue 72 from the nozzle row 642.

[0068] The black ink and the cyan ink, which contain the optimized combination of dyes as described above, have a small difference in ejection behavior. Therefore, even when the same drive signal is used, both inks can be ejected in an optimal manner. This makes it possible to realize a printer 11 that can perform recording with excellent continuous printing stability while enabling ejection from two nozzle rows 641 and 642 that eject ink of different colors using a common drive signal.

[0069] The content of CI Reactive Black 39 in the black ink is preferably 6.0% by mass or more and 18.0% by mass or less, more preferably 8.0% by mass or more and 18.0% by mass or less, and even more preferably 9.0% by mass or more and 15.0% by mass or less, of the total amount of the black ink.

[0070] The dye concentration of the black ink is set relatively high to obtain a dark print density. On the other hand, the cyan ink containing the above-mentioned CI Reactive Blue 72 tends to behave as if it were an ink with a high dye concentration, since the molecules of the phthalocyanine dye tend to associate with each other. Therefore, the ejection behavior of the black ink in which the content of CI Reactive Black 39 is set within the above range and the cyan ink containing the above-mentioned CI Reactive Blue 72 are closer to each other. As a result, the continuous printing stability of both inks can be particularly improved.

[0071] The black ink may contain CI Reactive Orange 12 in addition to CI Reactive Black 39. This improves the color development of the black ink.

[0072] The content of CI Reactive Orange 12 is preferably 50.0 parts by mass or less, and more preferably 10.0 parts by mass or more and 30.0 parts by mass or less, per 100 parts by mass of the content of CI Reactive Black 39.

[0073] The content of CI Reactive Black 39 in the black ink is preferably 50% by mass or more, and more preferably 55% by mass or more, of the dye content in the black ink, which further improves both continuous printing stability and color development.

[0074] The content of CI Reactive Blue 72 in the cyan ink is preferably 9.0% by mass or more and 15.0% by mass or less, and more preferably 10.0% by mass or more and 14.0% by mass or less, of the total amount of the cyan ink.

[0075] As described above, the cyan ink containing CI Reactive Blue 72 tends to behave as if it were an ink with a high dye concentration. When the content of CI Reactive Blue 72 is within the above range, the behavior of the cyan ink becomes closer to that of the black ink. Therefore, the ejection behavior of the cyan ink in which the content of CI Reactive Blue 72 is set within the above range and the black ink containing the above-mentioned CI Reactive Black 39 become closer to each other. As a result, the continuous printing stability of both inks can be particularly improved.

[0076] The above-mentioned effects are obtained in an inkjet recording method that includes at least the black ink ejection step S102 and the cyan ink ejection step S104. Therefore, the other steps described above may be omitted.

[0077] 2.2. Red ink ejection process and gray ink ejection process In the red ink ejection step S106, red ink is ejected from the nozzle row 641 of the liquid ejection head 60B (third liquid ejection head). In the gray ink ejection step S108, gray ink is ejected from the nozzle row 642 of the liquid ejection head 60B.

[0078] The dye contained in the red ink is not particularly limited, but it is preferable that the red ink contains at least one of CI Reactive Red 24:1 and CI Reactive Red 3:1.

[0079] The total content of at least one of CI Reactive Red 24:1 and CI Reactive Red 3:1 in the red ink is preferably 8.0% to 15.0% by mass, and more preferably 10.0% to 14.0% by mass, of the total amount of the red ink.

[0080] When fabric is used as the recording medium 13, such a red ink enables image formation with excellent dye adhesion and color development.

[0081] The dye contained in the gray ink is not particularly limited, but it is preferable that the gray ink contains at least one of CI Reactive Blue 49 and CI Reactive Black 39.

[0082] The total content of at least one of CI Reactive Blue 49 and CI Reactive Black 39 in the gray ink is preferably 1.0% to 7.0% by mass, and more preferably 2.0% to 5.0% by mass, of the total amount of the gray ink.

[0083] When fabric is used as the recording medium 13, such a gray ink enables image formation with excellent dye adhesion and color development.

[0084] In this embodiment, the gray ink is ejected from the liquid ejection head 60B (third liquid ejection head), which is different from the liquid ejection head 60A (first liquid ejection head) and the liquid ejection head 60D (second liquid ejection head). As described above, this gray ink contains CI Reactive Blue 49 and CI Reactive Black 39.

[0085] According to this configuration, the gray ink is ejected from the liquid ejection head 60B, which is different from the liquid ejection head 60A that ejects the black ink and the liquid ejection head 60D that ejects the yellow ink, so that the continuous printing stability of the gray ink can be ensured. Specifically, since the dye concentrations of the gray ink and the black ink are significantly different, it is difficult to eject them using the same drive signal. Therefore, by using different heads to eject the gray ink and the black ink, as in this embodiment, it is possible to use drive signals suitable for each ink. As a result, the continuous printing stability can be ensured for both inks.

[0086] Furthermore, when gray ink and yellow ink are mixed with each other unintentionally, the image quality of the image created with each ink is significantly deteriorated. In particular, yellow ink has a high saturation, so there is a risk that the hue will change significantly when the gray ink is mixed with the yellow ink. Therefore, by using different heads to eject gray ink and yellow ink, it is possible to suppress the occurrence of color mixing that occurs, for example, during the maintenance operation described above. As a result, it is possible to suppress the deterioration of image quality that occurs due to color mixing.

[0087] Furthermore, the gray ink may contain CI Reactive Orange 12 in addition to CI Reactive Blue 49 and CI Reactive Black 39. This improves the color development of the gray ink.

[0088] The content of CI Reactive Orange 12 is preferably 50.0 parts by mass or less, and more preferably 10.0 parts by mass or more and 40.0 parts by mass or less, relative to 100 parts by mass of the total content of CI Reactive Blue 49 and CI Reactive Black 39.

[0089] The total content of CI Reactive Blue 49 and CI Reactive Black 39 in the gray ink is preferably 50% by mass or more, and more preferably 60% by mass or more, of the total dye content in the gray ink, which further improves both continuous printing stability and color development.

[0090] 2.3. Blue ink ejection process and magenta ink ejection process In the blue ink ejection step S110, blue ink is ejected from the nozzle row 641 of the liquid ejection head 60C. In the magenta ink ejection step S112, magenta ink is ejected from the nozzle row 642 of the liquid ejection head 60C.

[0091] The dye contained in the blue ink is not particularly limited, but it is preferable that the blue ink contains CI Reactive Blue 49.

[0092] The content of CI Reactive Blue 49 in the blue ink is preferably 8.0% by mass or more and 15.0% by mass or less, and more preferably 10.0% by mass or more and 14.0% by mass or less, of the total amount of the blue ink.

[0093] When fabric is used as the recording medium 13, such a blue ink enables image formation with excellent dye adhesion and color development.

[0094] The dye contained in the magenta ink is not particularly limited, but it is preferable that the magenta ink contains at least one of CI Reactive Red 31 and CI Reactive Red 245.

[0095] The total content of at least one of CI Reactive Red 31 and CI Reactive Red 245 in the magenta ink is preferably 8.0% by mass or more and 15.0% by mass or less, and more preferably 10.0% by mass or more and 14.0% by mass or less, of the total amount of the magenta ink.

[0096] When fabric is used as the recording medium 13, such a magenta ink enables image formation with excellent dye adhesion and color development.

[0097] 2.4.Orange ink ejection process and yellow ink ejection process Moreover, the inkjet recording method shown in FIG. 5 includes an orange ink ejection step S114 and a yellow ink ejection step S116.

[0098] In the orange ink ejection process S114, orange ink is ejected from nozzle row 641 (third nozzle row) of liquid ejection head 60D (second liquid ejection head). In the yellow ink ejection process S116, yellow ink is ejected from nozzle row 642 (fourth nozzle row) of liquid ejection head 60D. Nozzle rows 641 and 642 are adjacent to each other in liquid ejection head 60D. Furthermore, the orange ink ejected from nozzle row 641 contains CI Reactive Orange 13 as a dye. Furthermore, the yellow ink ejected from nozzle row 642 contains CI Reactive Yellow 95 as a dye.

[0099] The orange ink and the yellow ink containing the dyes of the optimized combination as described above have hues close to each other. Therefore, even if unintended ink mixing occurs between the adjacent nozzle rows 641 and 642 due to, for example, the maintenance operation described above, it is possible to obtain the effect that the image quality of the image formed by each ink is unlikely to deteriorate. As a result, it is possible to realize an inkjet recording method in which the image quality of the image formed by the orange ink and the image quality of the image formed by the yellow ink are unlikely to deteriorate even if unintended ink mixing occurs after the maintenance operation is performed.

[0100] Furthermore, in this embodiment, the yellow ink is ejected from a liquid ejection head 60D that is different from the liquid ejection head 60A that ejects the black ink. Since the yellow ink has a high saturation, there is a risk that the saturation will be significantly reduced if the yellow ink is mixed with the black ink. Therefore, by ejecting the yellow ink from different heads, it is possible to suppress the occurrence of color mixing between the yellow ink and the black ink, for example, that occurs during the maintenance operation described above. As a result, it is possible to suppress the deterioration of image quality that is caused by color mixing.

[0101] The content of CI Reactive Orange 13 in the orange ink is preferably 8.0% by mass or more and 15.0% by mass or less, and more preferably 10.0% by mass or more and 14.0% by mass or less, of the total amount of the orange ink.

[0102] When fabric is used as the recording medium 13, such an orange ink enables image formation with excellent dye adhesion and color development.

[0103] The content of CI Reactive Yellow 95 in the yellow ink is preferably 8.0% by mass or more and 15.0% by mass or less, and more preferably 10.0% by mass or more and 14.0% by mass or less, of the total amount of the yellow ink.

[0104] When a fabric is used as the recording medium 13, such a yellow ink enables image formation with excellent dye adhesion and color development.

[0105] 2.5.Other dyes When each ink contains the above-mentioned dye as a main component, it may contain a dye (secondary component) other than the main component.

[0106] Other dyes include, for example, CIReactive Black 1, 2, 3, 5, 8, 10, 12, 13, 14, 31, 34, 39, CIReactive Yellow 2, 3, 6, 7, 12, 15, 17, 18, 22, 23, 24, 25, 27, 37, 39, 42, 57, 69, 76, 81, 84, 85, 86, 87, 92, 95, 102, 105, 111, 125, 135, 136, 137, 142, 143, 145, 151, 160, 161, 165, 167, 168, 175, 176, 181, and CIReactive Red. 2, 3, 3:1, 4, 5, 7, 8, 11, 12, 13, 15, 16, 21, 22, 23, 24, 24:1, 25, 26, 28, 29, 31, 32, 33, 35, 39, 40, 41, 43, 45, 46, 49, 55, 56, 58, 59, 65, 66, 78, 83, 106, 111, 112, 113, 11 4, 116, 120, 123, 124, 128, 130, 136, 141, 147, 158, 159, 171, 174, 176, 180, 183, 18 4, 187, 190, 193, 194, 195, 198, 218, 220, 222, 223, 226, 228, 235, 245, CIReactive Blue 2, 3, 4, 5, 7, 13, 14, 15, 19, 21, 25, 26, 27, 28, 29, 38, 39, 40, 41, 46, 49, 50, 52, 63, 69, 71, 72, 77, 79, 89, 104, 109, 112, 113, 114, 116, 119, 120, 122, 13 7, 140, 143, 147, 160, 161, 162, 163, 168, 171, 176, 182, 184, 191, 194, 195, 198, 203, 204, 207, 209, 211, 214, 220, 221, 222, 231, 235, 236, CIReactive Orange 1, 2, 4, 5, 7, 11, 12, 13, 15, 16, 20, 30, 35, 56, 64, 67, 69, 70, 72, 74, 82, 84, 86, 87, 91, 92, 93, 95, 99, 107, CIReactive Violet 1, 2, 4, 5, 6, 22, 23, 33, 36, 38, CIReactive Green 5, 8, 12, 15, 19, 21, CIReactive Brown 1, 2, 7, 8, 9, 10, 11, 14, 17, 18, 19, 21, 23, 31, 37, 43, 46, etc. These dyes are used alone or in combination of two or more kinds.

[0107] The total content of the sub-components in each ink is preferably 0.1 to 50.0 parts by mass, more preferably 0.5 to 45.0 parts by mass, even more preferably 1.0 to 40.0 parts by mass, and particularly preferably 5.0 to 30.0 parts by mass, relative to 100 parts by mass of the main component. By including the sub-components in such a ratio, the desired hue can be obtained without impairing the continuous printing stability described above.

[0108] 2.6.Other Ingredients Each ink may contain organic solvents, water, chelating agents, and other substances.

[0109] 2.6.1. Organic Solvents Examples of the organic solvent include cyclic amides, alkyl polyols, glycol ethers, and other organic solvents.

[0110] Examples of the cyclic amide include lactams such as 2-pyrrolidone, 1-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone), 1-ethyl-2-pyrrolidone (N-ethyl-2-pyrrolidone), N-vinyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, 1-butyl-2-pyrrolidone, and 1-(2-hydroxyethyl)-2-pyrrolidone (N-(2-hydroxyethyl)-2-pyrrolidone). These cyclic amides may be used alone or in combination of two or more.

[0111] The black ink, cyan ink, red ink, gray ink, blue ink, magenta ink, orange ink and yellow ink each preferably contain 1-(2-hydroxyethyl)-2-pyrrolidone. This can particularly suppress bleeding of each ink. In addition, the continuous printing stability of each ink can be improved.

[0112] When cyclic amides are contained, the total content thereof is preferably 1.0 mass% or more and 30.0 mass% or less, more preferably 3.0 mass% or more and 30.0 mass% or less, even more preferably 3.0 mass% or more and 20.0 mass% or less, and particularly preferably 5.0 mass% or more and 13.0 mass% or less, relative to the total amount of each ink.

[0113] Examples of alkyl polyols include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol, etc. These alkyl polyols may be used alone or in combination of two or more.

[0114] When alkyl polyols are contained, the total content thereof is preferably 1.0% by mass or more and 15.0% by mass or less, more preferably 2.0% by mass or more and 10.0% by mass or less, and even more preferably 2.5% by mass or more and 5.0% by mass or less, relative to the total amount of each ink.

[0115] As the glycol ether, for example, a monoalkyl ether of a glycol selected from ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol is preferable. More preferably, methyl triglycol (triethylene glycol monomethyl ether), butyl triglycol (triethylene glycol monobutyl ether), butyl diglycol (diethylene glycol monobutyl ether), dipropylene glycol monopropyl ether, etc. are mentioned. These glycol ethers may be used alone or in combination of two or more kinds.

[0116] When glycol ether is contained, the total content thereof is preferably 0.5% by mass or more and 30.0% by mass or less, more preferably 1.0% by mass or more and 20.0% by mass or less, and even more preferably 3.0% by mass or more and 15.0% by mass or less, relative to the total amount of each ink.

[0117] Examples of other organic solvents include lactones such as γ-butyrolactone, and betaine compounds.

[0118] 2.6.2.Water Examples of water include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, as well as ultrapure water from which ionic impurities have been removed as much as possible.

[0119] The lower limit of the water content is 30% by mass or more, preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more, based on the total amount of each ink. The upper limit of the water content is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, based on the total amount of each ink.

[0120] Chelating Agents Examples of chelating agents include EDTA, ethylenediaminetetraacetic acid or its salts such as EDTA-2Na (ethylenediaminetetraacetic acid dihydrogen disodium salt), EDTA-3Na (ethylenediaminetetraacetic acid monohydrogen trisodium salt), EDTA-4Na (ethylenediaminetetraacetic acid tetrasodium salt), and EDTA-3K (ethylenediaminetetraacetic acid monohydrogen tripotassium salt), DTPA, DTPA-2Na (diethylenetriaminepentaacetic acid disodium salt), and DTPA-5Na (diethylenetriaminepentaacetic acid dihydrogen tripotassium salt). diethylenetriaminepentaacetic acid or a salt thereof such as diethylenetriaminepentaacetic acid pentasodium salt, nitrilotriacetic acid or a salt thereof such as NTA, NTA-2Na (nitrilotriacetic acid disodium salt), and NTA-3Na (nitrilotriacetic acid trisodium salt), ethylenediamine-N,N'-disuccinic acid or a salt thereof, 3-hydroxy-2,2'-iminodisuccinic acid or a salt thereof, L-aspartic acid-N,N'-diacetic acid or a salt thereof, and N-(2-hydroxyethyl)iminodiacetic acid or a salt thereof.

[0121] Examples of chelating agents other than acetate analogs include ethylenediaminetetramethylenephosphonic acid or salts thereof, ethylenediaminetetrametaphosphoric acid or salts thereof, ethylenediaminepyrophosphoric acid or salts thereof, and ethylenediaminemetaphosphoric acid or salts thereof.

[0122] These chelating agents may be used alone or in combination of two or more. When a chelating agent is contained, the total content is preferably 2000 ppm or less, more preferably 1000 ppm or less, even more preferably 800 ppm or less, and particularly preferably 600 ppm or less, based on the total amount of each ink.

[0123] 2.6.4. Other substances Other substances include surfactants, pH adjusters, preservatives, fungicides, rust inhibitors, ureas, sugars, etc.

[0124] Surfactants Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, etc., which may be used in combination. Among the surfactants, acetylene glycol surfactants, silicone surfactants, and fluorine surfactants are preferably used.

[0125] Examples of acetylene glycol surfactants include Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, and DF110D (trade names, Air Products and Chemicals). Examples of such amines include Olefin B, Y, P, A, STG, SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, PD-005, EXP.4001, EXP.4036, EXP.4051, AF-103, AF-104, AK-02, SK-14, and AE-3 (trade names, manufactured by Nissin Chemical Industry Co., Ltd.), and Acetylenol E00, E00P, E40, and E100 (trade names, manufactured by Kawaken Fine Chemicals Co., Ltd.).

[0126] It is preferable that each of the above-mentioned black ink, cyan ink, red ink, gray ink, blue ink, magenta ink, orange ink, and yellow ink contains Olfin PD-002W, which can particularly suppress bleeding of each ink.

[0127] As the silicone surfactant, a polysiloxane compound is preferably used, for example, a polyether-modified organosiloxane. Examples of commercially available polyether-modified organosiloxanes include BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (trade names, manufactured by BYK Co.), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, and KF-6017 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0128] As the fluorine-based surfactant, a fluorine-modified polymer is preferably used, and a specific example thereof is BYK-340 (trade name, manufactured by BYK-Chemie Japan KK).

[0129] When surfactants are contained, the total content is preferably from 0.01% by mass to 3.0% by mass, more preferably from 0.05% by mass to 2.0% by mass, even more preferably from 0.10% by mass to 1.5% by mass, and particularly preferably from 0.20% by mass to 1.0% by mass, relative to the total amount of each ink.

[0130] 2.6.4.2. pH adjusters Examples of the pH adjuster include a suitable combination of an acid, a base, a weak acid, and a weak base.

[0131] Examples of acids and bases used in such combinations include inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid; inorganic bases such as lithium hydroxide, sodium hydroxide, potassium hydroxide, potassium dihydrogen phosphate, disodium hydrogen phosphate, potassium carbonate, sodium carbonate, sodium hydrogen carbonate, and ammonia; organic bases such as triethanolamine, diethanolamine, monoethanolamine, tripropanolamine, triisopropanolamine, diisopropanolamine, and tris(hydroxymethyl)aminomethane (THAM); and organic acids such as adipic acid, citric acid, succinic acid, lactic acid, and N,N-bis(2-hydroxypropyl)amine.

[0043] Good's buffers such as N-(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), morpholinoethanesulfonic acid (MES), carbamoylmethyliminobisacetic acid (ADA), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), cholamine hydrochloride, N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), acetamidoglycine, tricine, glycineamide, and bicine, phosphate buffer, citrate buffer, Tris buffer, and the like may also be used.

[0132] When a pH adjuster is contained, the total content is preferably from 0.01% to 2.0% by mass, and more preferably from 0.10% to 1.0% by mass, based on the total amount of each ink.

[0133] 2.6.4.3. Antiseptics, mildew inhibitors, and rust inhibitors Examples of preservatives and antifungal agents include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazolin-3-one (Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN, and Proxel LV, both manufactured by Zeneca), and 4-chloro-3-methylphenol (Preventol CMK, manufactured by Bayer). An example of the rust inhibitor is benzotriazole.

[0134] 2.6.4.4.Ureas Examples of ureas include urea, ethylene urea, tetramethyl urea, thiourea, and 1,3-dimethyl-2-imidazolidinone.

[0135] When ureas are contained, the total content thereof is preferably 1.0% by mass or more and 10.0% by mass or less based on the total amount of each ink.

[0136] Sugars Examples of sugars include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose.

[0137] Other Examples of the components other than those mentioned above include antioxidants, ultraviolet absorbers, oxygen absorbers, and dissolution aids.

[0138] The inkjet recording method and inkjet recording apparatus of the present invention have been described above based on the illustrated embodiments, but the inkjet recording method of the present invention is not limited to the above-described embodiments, and may be, for example, a process for any purpose added to the above-described embodiments. The inkjet recording apparatus of the present invention is not limited to the above-described embodiments, and may be, for example, a process for any purpose replaced with the components of the above-described embodiments, and may be a process for any purpose added to the above-described embodiments. EXAMPLES

[0139] Next, an embodiment of the present invention will be described. 3. Ink Preparation Ink for each Example and Comparative Example was prepared by placing each component in a container so as to obtain the composition shown in Table 1, mixing and stirring the components using a magnetic stirrer at room temperature for 1 hour, and then filtering the mixture through a membrane filter having a pore size of 1 μm. Note that "%" in Table 1 indicates mass %. The remainder other than the components shown in Table 1 is ion-exchanged water, and the total mass including ion-exchanged water is 100 mass %.

[0140] In addition, in the dyes shown in Table 1, "RBk" stands for CIReactive Black, "RB" stands for CIReactive Blue, "RR" stands for CIReactive Red, "RO" stands for CIReactive Orange, and "RY" stands for CIReactive Yellow.

[0141] Furthermore, in Table 1, "HEP" for the components other than the dyes represents 1-(2-hydroxyethyl)-2-pyrrolidone, and "2-P" represents 2-pyrrolidone.

[0142] Furthermore, the content of the multiple dyes contained in the black ink shown in Table 1 is listed for each type of dye contained in the black ink. For example, in Example 1, the black ink contains 9.0% RBk39, 2.0% RR3:1, 2.0% RO12, and 2.0% RO13. Similarly, the content of the multiple dyes contained in the gray ink shown in Table 1 is listed for each type of dye contained in the gray ink. For example, in Example 1, the gray ink contains 0.5% RBk39, 0.5% RR245, 1.5% RB49, and 0.5% RO12.

[0143] [Table 1]

[0144] 4. Evaluation of inkjet recording 4.1.Continuous printing stability The eight color inks of each of the examples and comparative examples shown in Table 1 were filled into ink cartridges of a printer manufactured by Seiko Epson Corporation. The printer used was equipped with four liquid jet heads 60A, 60B, 60C, and 60D shown in Table 1. Each of the liquid jet heads 60A, 60B, 60C, and 60D was equipped with two nozzle rows 641 and 642, and one of eight colors of ink was assigned to each of the nozzle rows 641 and 642 so that inks of different colors were supplied to each of the nozzle rows 641 and 642. The two colors of ink assigned to one liquid jet head were ejected from the nozzles of each liquid jet head by the same drive signal.

[0145] Next, after confirming that ink was being ejected from all of the nozzles, a 10% duty pattern (photographic image) was continuously printed on 2,000 sheets of A4 size recording paper.

[0146] Next, among the printed images, the image using the black ink and the image using the cyan ink were visually checked for the presence or absence of missing ink ejection, and were evaluated against the following evaluation criteria.

[0147] A: Less than 2% of discharge is missing B: Discharge loss is 2% or more but less than 3% C: Discharge loss is 3% or more but less than 5% D: Missing discharge is 5% or more The evaluation results are shown in Table 1.

[0148] 4.2.Image quality degradation due to color mixing The eight color inks of each of the Examples and Comparative Examples shown in Table 1 were filled into ink cartridges of a printer PX-G930 manufactured by Seiko Epson Corp. The ink cartridges were then placed in an environment of 40° C. for 24 hours.

[0149] Next, the printer's head cleaning operation (maintenance operation) was performed three times, and after confirming that ink was being ejected from all the nozzles, the printer was left in an environment of 40°C for 24 hours.

[0150] Next, a solid pattern was printed in yellow ink on A4 size photo paper (photo glossy paper manufactured by Seiko Epson Corporation).

[0151] Next, the printed image was visually checked for deterioration in image quality due to color mixing, and was evaluated according to the following evaluation criteria.

[0152] A: No degradation of image quality due to color mixing B: There is slight degradation in image quality due to color mixing at the beginning of printing. C: Image quality is degraded due to color mixing at the beginning of printing. D: Image quality degradation due to color mixing is noticeable at the beginning of printing. The evaluation results are shown in Table 1.

[0153] 4.3.Evaluation Results As shown in Table 1, the black ink and cyan ink containing a specific dye had good continuous printing stability even when ejected from a liquid ejection head supplied with the same drive signal. On the other hand, it was found that the continuous printing stability was poor when the ink color combination was a combination other than "black / cyan" as in Comparative Examples 1, 2, and 4, or when the ink contained a dye different from the specific dye even in the "black / cyan" combination as in Comparative Examples 3 and 5.

[0154] It was also found that in images using yellow ink containing a specific dye, degradation in image quality due to color mixing with orange ink containing a specific dye was suppressed.

[0155] Furthermore, it was found that by optimizing the allocation of inks to the liquid ejection head so that yellow ink, black ink, and gray ink are not ejected from adjacent nozzle rows, it is possible to suppress degradation of image quality due to color mixing in images using yellow ink. [Explanation of symbols]

[0156] 11... printer, 12... support stand, 13... recording medium, 14... transport unit, 15... printing unit, 16... printer body, 17... cover, 18... transport roller pair, 19... transport roller pair, 20... guide plate, 22... guide shaft, 23... guide shaft, 24... carriage motor, 25... carriage, 25A... carriage body, 25B... carriage base, 26... nozzle, 28... movement mechanism, 30... ink cartridge, 31... supply mechanism, 32... mounting unit, 33... supply Supply path, 34...supply pump, 35...filter unit, 36...static mixer, 37...liquid storage chamber, 38...pressure adjustment unit, 39...control unit, 40...diaphragm pump, 41...suction valve, 42...discharge valve, 43...maintenance mechanism, 44...liquid receiving portion, 45...flushing unit, 47...cleaning mechanism, 50...maintenance unit, 51...unit frame, 52...opening, 53...fixing plate, 54...wiping member, 55...absorbent member , 56A...cap, 56B...cap, 56C...cap, 56D...cap, 60...liquid jet head, 60A...liquid jet head, 60B...liquid jet head, 60C...liquid jet head, 60D...liquid jet head, 61...bracket portion, 62...head main body portion, 63...cover member, 64...nozzle row, 66A...through hole, 66B...through hole, 66C...through hole, 66D...through hole, 70...holder drive portion, 71...electric motor, 72...belt, 73 ...guide frame, 75...unit holder, 641...nozzle row, 642...nozzle row, A...supply direction, HP...home position, PA...transport area, S102...black ink ejection process, S104...cyan ink ejection process, S106...red ink ejection process, S108...gray ink ejection process, S110...blue ink ejection process, S112...magenta ink ejection process, S114...orange ink ejection process, S116...yellow ink ejection process

Claims

1. A step of ejecting a black ink containing C.I. Reactive Black 39 from a first liquid ejection head; A step of ejecting a cyan ink containing C.I. Reactive Blue 72 from the first liquid ejection head; A step of ejecting an orange ink containing C.I. Reactive Orange 13 from a second liquid ejection head; A step of ejecting a yellow ink containing C.I. Reactive Yellow 95 from the second liquid ejection head; having The first liquid jet head includes: a first nozzle row and a second nozzle row adjacent to each other, The black ink is ejected from the first nozzle row, The cyan ink is ejected from the second nozzle row, The second liquid jet head is a third nozzle row and a fourth nozzle row adjacent to each other, The orange ink is ejected from the third nozzle row, the yellow ink is ejected from the fourth nozzle row.

2. 2. The ink-jet recording method according to claim 1, wherein a content of C. I. Reactive Black 39 is 8.0% by mass or more and 18.0% by mass or less of a total amount of the black ink.

3. 3. The ink-jet recording method according to claim 1, wherein a content of C. I. Reactive Blue 72 is 9.0% by mass or more and 15.0% by mass or less of a total amount of the cyan ink.

4. A step of ejecting a black ink containing C.I. Reactive Black 39 from a first liquid ejection head; A step of ejecting a cyan ink containing C.I. Reactive Blue 72 from the first liquid ejection head; ejecting orange ink from a second liquid jet head; ejecting yellow ink from the second liquid jet head; ejecting a gray ink containing C.I. Reactive Blue 49 and C.I. Reactive Black 39 from a third liquid ejection head different from the first liquid ejection head and the second liquid ejection head; having The first liquid jet head includes: a first nozzle row and a second nozzle row adjacent to each other, The black ink is ejected from the first nozzle row, The cyan ink is ejected from the second nozzle row, The second liquid jet head is a third nozzle row and a fourth nozzle row adjacent to each other, The orange ink is ejected from the third nozzle row, the yellow ink is ejected from the fourth nozzle row.

5. 5. The inkjet recording method according to claim 4, wherein the black ink, the cyan ink, the yellow ink, the orange ink and the gray ink contain 1-(2-hydroxyethyl)-2-pyrrolidone.

6. a first liquid ejection head having a first nozzle row and a second nozzle row adjacent to each other, and a second liquid ejection head having a third nozzle row and a fourth nozzle row adjacent to each other; The first liquid jet head includes: A black ink containing C.I. Reactive Black 39 is ejected from the first nozzle row, A cyan ink containing C.I. Reactive Blue 72 is ejected from the second nozzle row, The second liquid jet head is An orange ink containing C.I. Reactive Orange 13 is ejected from the third nozzle row, An inkjet recording apparatus, characterized in that a yellow ink containing C.I. Reactive Yellow 95 is ejected from the fourth nozzle row.

Images