JP2009139665A - Coating liquid removing device and coating liquid removing method for inkjet head, and manufacturing method of color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating liquid removing device for an inkjet head provided with a means for removing the remaining coating liquid, which is a non-contact type and can completely remove the coating liquid remaining on the outlet surface of a nozzle hole after pressure purge and suction purge of the coating liquid of the inkjet head in a short period of time and does not cause an air flow, and a coating liquid removing method for the inkjet head, and to provide the manufacturing method of color filter for manufacturing a high-quality color filter by using the coating liquid removing method for the inkjet head. <P>SOLUTION: The coating liquid removing device for the inkjet head comprises: a transfer plate provided with a plurality of transfer surfaces divided in the longitudinal direction of the inkjet head; a proximity means for arranging the plurality of transfer surfaces in close proximity to the outlet surface of the nozzle hole nearly in parallel with one another with a fixed gap; and a movement means for moving the transfer plate arranged in close proximity to the outlet surface of nozzle hole in the longitudinal direction of the inkjet head to transfer the remaining coating liquid to the transfer plate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is mainly used in the field of manufacturing color filters for color liquid crystal displays, and more specifically, an ink jet head related to forming a color filter by discharging R, G, B coating liquids with an ink jet head. The present invention relates to an improvement in a residual coating solution removing apparatus, a residual coating solution removing method, and a color filter manufacturing method.

  The color liquid crystal display includes a color filter, a TFT array substrate, and the like. In this color filter, each pixel bordered by a grid-like black matrix on a glass substrate is regularly formed by dividing it into three colors of R (red), G (green), and B (blue). It is the member which makes the center of the color formation of the display.

  This color filter is usually 1) forming a coating film of a black photoresist material on a glass substrate, and processing the black coating film into a lattice shape by photolithography (formation of a lattice-like black matrix), 2) once R The coating film is formed on the entire surface, and the R coating film is left only on the R pixels between the lattices by photolithography (R pixel formation). After the coating film is formed on the entire surface, the B and G coating films are left only on the B and G pixels (B and G pixel formation).

  In forming the R, G, and B pixels by the above-described photolithography method, many processes such as R, G, and B whole surface coating film formation, exposure, and development are required. In recent years, in order to simplify this, only R, G, and B coating liquids are directly supplied to the pixel portion formed by a black matrix lattice by an inkjet head to form R, G, and B color pixels. The technique has come to be carried out industrially (for example, Patent Document 1).

  This method of forming R, G, and B pixels using an ink jet head does not require steps such as exposure and development, and uses only the amount of coating liquid necessary for forming color pixels, thereby enabling a significant cost reduction in color filter manufacturing. To do.

  Ink jet heads usually have a large number of nozzle holes, and by operating intermittent driving means such as a piezoelectric element provided for each nozzle hole, the coating liquid can be intermittently discharged from the nozzle holes. However, if the coating liquid is discharged from the nozzle hole for a long time, foreign matter such as solidified liquid or dust of the coating liquid adheres to the periphery of the nozzle hole, thereby preventing normal discharge of the coating liquid from the nozzle hole. As a result, the flying direction of the coating liquid is not determined.

  For this reason, there is a problem in that the coating liquid cannot be landed on the target position, and color pixel formation of the accurate color filter cannot be performed. In this case, pressurize and purge the inkjet head every time several to tens of sheets are applied, discharge a large amount of coating liquid from the nozzle holes, dissolve the solidified material, and wash away foreign matter such as dust. Then, the nozzle hole is cleaned. This avoids the above problem.

  Of the many nozzle holes of the ink jet head, those that do not coincide with the color pixels of the color filter are temporarily not used. In this case, the solvent in the coating solution stored in the nozzle hole volatilizes, the solid content concentration of the coating solution increases, and the coating solution becomes highly viscous. Such a high-viscosity coating liquid cannot be pushed out of the nozzle hole due to insufficient power by the intermittent driving means of the nozzle hole. Therefore, a high pressure is applied to the coating liquid supplied to the ink jet head and the liquid is pushed out from the nozzle hole by pressurized pressure feeding (pressure purge), or the viscosity is increased by applying a suction force from the outlet side of the nozzle hole. (Suction purge).

  When a large amount of coating liquid is discharged from the nozzle hole by pressure purge or suction purge for cleaning the nozzle hole or discharging the high viscosity coating liquid stored in the nozzle hole, the coating liquid discharge function of the inkjet head is achieved. Although the initial good state can be restored, a large amount of the coating liquid discharged from the nozzle hole spreads while adhering to the nozzle hole outlet surface where the nozzle hole outlet is located. A part of the coating liquid naturally falls from the nozzle hole exit surface due to its own weight, while the other coating liquid remains on the nozzle hole exit surface around the periphery of the nozzle hole outlet.

  If the coating liquid remaining on the nozzle hole exit surface is left as it is and an attempt is made to discharge the coating liquid from the nozzle hole by intermittent drive means, the same problem as when the coating liquid or foreign matter adheres to the periphery of the nozzle hole. Produce. For this reason, the coating liquid remaining on the nozzle hole outlet surface after the pressure purge or the suction purge is usually removed by the coating liquid removing means.

  A typical example of the coating liquid removing means is a wiping system that removes the remaining coating liquid by sliding a blade-like wiper on the exit surface of the nozzle hole (for example, Patent Document 2).

  A liquid repellent layer is usually formed on the surface of the nozzle hole outlet surface in order to improve the liquid separation of the coating liquid and to discharge and fly with high accuracy. Since the liquid layer is also worn away, there arises a disadvantage that the coating liquid cannot be stably discharged.

  As a non-contact coating solution removing means that does not wear the liquid repellent layer, a vacuum nozzle is brought close to the coating solution remaining on the exit surface of the nozzle hole, and the remaining coating solution is sucked and removed by a negative pressure suction action (for example, patent) Reference 3) By moving the blade-like wiper in the longitudinal direction with a certain gap with respect to the nozzle hole exit surface, the residual coating liquid in contact with the wiper under the nozzle hole exit surface is guided and transferred to the wiper. (For example, Patent Document 4), a plate having high lyophilicity on a nozzle hole outlet surface is moved close to / separated with a certain gap to transfer the residual coating liquid on the nozzle hole outlet surface to the plate surface (for example, Patent Document 5), etc. are proposed.

  However, with the means disclosed in the above-mentioned Patent Document 3, it is not possible to remove all the remaining coating liquid with the suction force generated by the negative pressure of the vacuum nozzle. Furthermore, the suction force caused by the negative pressure causes an abrupt air flow on the nozzle hole exit surface, which accelerates the volatilization of the solvent of the coating solution stored in the nozzle hole and increases the viscosity of the coating solution. There has also been a problem that normal ejection by the intermittent drive means cannot be performed from the nozzle hole after the coating liquid removing operation.

  In the means of Patent Document 4, since the contact area between the residual coating liquid and the wiper is small, it is necessary to reduce the moving speed in order to transfer all of the residual coating liquid. Accordingly, in addition to the long time required for the work, there is a problem that the residual coating liquid having a size smaller than the gap between the nozzle hole outlet surface and the wiper does not contact the wiper and cannot be removed at all.

Furthermore, in the means of Patent Document 5, since the residual coating liquid is transferred due to the lyophilic difference between the nozzle hole exit surface and the plate surface, a transfer force is required to transfer all the residual coating liquid to the plate surface. In addition to being insufficient, it is difficult to maintain the lyophilicity of the plate surface to which the coating liquid is transferred, and the lyophilicity deteriorates with time, resulting in a decrease in the amount of residual coating liquid removed. there were.
JP 2006-209140 A (paragraphs 0019 to 0031, FIG. 1) JP 2006-315225 A (paragraphs 0038 to 0041, FIG. 3) Japanese Patent Laying-Open No. 2005-169730 (paragraphs 0029 to 0033, FIG. 1) JP 2007-190818 A (paragraphs 0018 to 0026, 0032, FIG. 7, FIG. 8, FIG. 9) JP-A-2006-326436 (paragraphs 0021 to 0032, 0052 to 0056, FIGS. 1, 4, 5, and 8)

  The present invention has been made based on the above-described circumstances, and the object thereof is to remove all of the coating liquid remaining on the nozzle hole outlet surface after a pressure purge and suction purge of the coating liquid of the inkjet head in a short time. A non-contact, non-contact, and non-flowing residual coating liquid removing means that can be removed is realized, and an inkjet head coating liquid removing apparatus and a coating liquid removing method that are provided with the means and have excellent residual coating liquid removal performance. It is to provide. Furthermore, another object of the present invention is to provide a method for producing a color filter that can produce a high-quality color filter that is low in cost and has no coating defects by using the above-described method for removing a coating solution from an inkjet head.

The object of the present invention is achieved by the means described below.
The inkjet head coating liquid removing apparatus according to the present invention is:
A coating liquid removing device remaining on the nozzle hole exit surface of the inkjet head,
A transfer plate comprising a plurality of transfer surfaces separated by grooves,
Proximity means for approaching the transfer plate and the nozzle hole exit surface at a predetermined interval;
And a moving means for moving the transfer plate while maintaining the predetermined interval with respect to the longitudinal direction of the outlet surface of the nozzle hole.

Here, it is preferable to further include a removing means for removing the coating liquid transferred to the transfer plate.
Moreover, the method of removing the coating liquid of the inkjet head according to the present invention is as follows.
A method for removing a coating liquid remaining on a nozzle hole exit surface of an inkjet head,
A step of bringing a transfer plate having a plurality of transfer surfaces separated by grooves close to a nozzle hole exit surface at a predetermined interval;
The coating liquid remaining on the nozzle hole outlet surface is transferred to the transfer plate by performing a step of moving the transfer plate while maintaining the predetermined interval with respect to the longitudinal direction of the nozzle hole outlet surface. .

  Here, it is preferable to remove the coating liquid on the transfer plate after the coating liquid remaining on the nozzle hole outlet surface of the inkjet head is transferred to the transfer plate.

  The method for producing a color filter according to the present invention is to produce a color filter by removing the residual coating solution using the coating solution removing method for an inkjet head described above and then applying the coating solution with the inkjet head. It is characterized by.

  By using the coating liquid removing apparatus and the coating liquid removing method of the inkjet head according to the present invention, a nozzle plate outlet surface is formed by bringing a transfer plate having a plurality of transfer surfaces close to the nozzle hole outlet surface where the coating liquid remains in a certain gap. Therefore, the remaining coating liquid between the transfer plate and the nozzle hole exit surface can be gathered to form a liquid film. Since the liquid film is removed by moving the liquid film on the nozzle hole exit surface with the transfer plate, the transfer plate does not contact the nozzle hole exit surface. Therefore, the residual coating liquid on the nozzle hole exit surface can be removed without damaging the liquid repellent layer on the nozzle hole exit surface.

  Furthermore, the coating droplets that remain irregularly in place and size on the nozzle hole exit surface can be spread and spread by the capillary action in the gap between the nozzle hole exit surface and the transfer plate surface. Regardless of the size, the residual coating liquid can be transferred to the transfer plate, and the residual coating liquid can be removed without causing air flow without contact. Also, since the transfer plate has a plurality of transfer surfaces, the residual coating liquid on the nozzle hole outlet surface can be transferred to the plurality of transfer surfaces by a single longitudinal scan of the transfer plate, and the nozzle hole outlet can be reliably and quickly delivered. It is possible to remove the remaining coating liquid on the surface.

  According to the color filter manufacturing method of the present invention, a color filter is manufactured using the above-described excellent inkjet head coating liquid removal method. A high-quality color filter without coating defects such as white defects can be manufactured stably for a long time with high productivity.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic front view of a coating liquid removing apparatus 100 and an ink jet head 10 according to the present invention, FIG. 2 is a plan view of a nozzle hole outlet surface 11 of the ink jet head 10 viewed from below, and FIG. FIG. 4 and FIG. 5 are flowcharts showing the state in which the coating liquid remaining on the inkjet head 10 is removed by the transfer plate 110 in stages.

  First, referring to FIG. 1, an inkjet head 10, its coating solution supply device 20, and a coating solution removing device 100 of the present invention are shown. The ink jet head 10 has a resin plate 13 below the main body 14, and a part of the ink jet head 10 protrudes downward to form a nozzle hole outlet surface 11.

  A liquid repellent layer is formed on the nozzle hole exit surface 11 by coating. The liquid repellent layer is preferably made of a liquid repellent resin such as Teflon (registered trademark) or silicon. Further, as shown in FIG. 2, a large number of nozzle holes 12 for discharging the coating liquid are arranged in a staggered pattern at a predetermined pitch in the longitudinal direction (Y direction) of the inkjet head 10 on the nozzle hole exit surface 11.

  When a large amount of the coating liquid is discharged from the nozzle hole 12, the coating liquid spreads on the nozzle hole outlet surface 11 and remains. The ink jet head 10 is connected to the coating liquid supply device 20 by a pipe 21. The coating liquid supply apparatus 20 includes a coating liquid storage unit 22 in which a coating liquid 29 is stored. Pressurized air adjusted to a predetermined pressure from a pressurized air source 25 is added to the coating liquid storage unit 22 via a pressurized pipe 24 and a pressurized valve 23. A negative pressure of a predetermined magnitude can be applied to the coating liquid storage unit 22 via a vacuum pipe 27 and a vacuum valve 26 from a vacuum source 28.

  When pressurizing the coating liquid storage unit 22 to a predetermined pressure, the pressure valve 23 is opened and the vacuum valve 26 is closed. When applying a negative pressure to the coating liquid storage unit 22, the vacuum valve 26 is opened and applied. The pressure valve 23 is closed.

  In FIG. 1, a coating liquid removing apparatus 100 removes the coating liquid remaining on the nozzle hole outlet surface 11 and holds one end of the transfer plate 110 and moves the transfer plate 110 up and down in the Z direction to exit the nozzle hole. Lift unit 120 that is a proximity unit that is brought close to the surface 11 with a predetermined gap S, and a transfer unit that moves the transfer plate 110 reciprocally freely in the longitudinal direction (Y direction) of the inkjet head 10 together with the lift unit 120. The unit 130 includes a removing unit 140 that is a removing unit that removes the residual coating liquid transferred to the transfer plate 110, and a base 136 that supports the transport unit 130 and the removing unit 140 in the direction of gravity. The constant gap S is a predetermined interval between the transfer plate 110 and the nozzle hole exit surface 11.

  Here, the transport unit 130 is illustrated as a support base 132 that supports the elevating unit 120, a rail 134 that guides the support base 132 in the Y direction, and a support base 132 that reciprocates freely along the rail 134 in the Y direction. It is composed of a linear motor that is not. Among these, the rail 134 and the stator of the linear motor are fixed to the base 136.

  The removal unit 140 includes a blade 142 that removes the coating liquid transferred to the transfer plate 110, a blade mounting base 144 that holds the blade 142, and a lifting unit 146 that freely lifts and lowers the blade 142 and the plate mounting base 144 in the vertical direction. A support base 150 that supports the lifting unit 146, a rail 152 that guides the support base 150 in the X direction (a direction perpendicular to the paper surface), and a support base 150 that reciprocates freely along the rail 152 in the X direction. It comprises a linear motor (not shown) and a waste liquid collection pan 154 for collecting the removed coating liquid. A transport unit 148 is configured by the support 150, the rail 152, and a linear motor (not shown).

  The removal unit 140 drives the elevating unit 146 to lower the blade 142 to contact the transfer surfaces 112A, B, and C of the transfer plate 110 that has moved downward as indicated by the alternate long and short dash line, and the blade 142 is moved to the transport unit 148. Accordingly, the coating liquid transferred onto the transfer surfaces 112A, B, and C can be removed by moving in the X direction (vertical depth side of the paper surface) and sliding on the transfer surfaces 112A, B, and C. The removed coating liquid becomes a plurality of liquid droplets, and falls naturally on the waste liquid collection pan 154 by gravity and is collected.

  The material of the blade 142 may be any material, such as synthetic resin and synthetic rubber, as long as it has chemical resistance to the coating solution and does not swell. Furthermore, it is preferable to select a material having high liquid repellency in order to improve the peelability of the removed coating liquid from the blade 142.

  Next, FIG. 3 shows details of the transfer plate 110. The transfer plate 110 includes a plurality of transfer surfaces 112A, B, and C, and grooves 114A and B that divide each of the transfer surfaces 112A, B, and C in the longitudinal direction (Y direction) of the inkjet head 10. That is, the transfer surfaces 112 </ b> A, B, and C are a plurality of transfer surfaces partitioned in the longitudinal direction of the inkjet head 10.

  The lengths of the transfer surfaces 112A, B, and C in the X direction are the same width W, but the lengths in the Y direction are D1, D2, and D3, respectively, and the areas where the coating liquid can be transferred are different. . The grooves 114A and B extend in the direction perpendicular to the longitudinal direction of the inkjet head 10, that is, in the X direction and have a width W. The length in the vertical direction (Z direction) is also the depth H, but the length in the Y direction. The lengths are lengths L1 and L2, respectively.

  Further, when the transfer plate 110 is moved in the Y direction by the transport unit 130 to remove the coating liquid, the transfer surface 112C starts from the leading edge 116 at one end of the transfer surface 112A and moves toward the end edge 117. The transfer end side 118 at one end is moved as the end.

  Next, the coating liquid removing method of the present invention using the coating liquid removing apparatus 100 of FIG. 1 will be described in detail with reference to FIG. 4 and FIG.

First, as a preparatory operation for removing the coating liquid remaining on the inkjet head 10, the transfer plate 110 and the blade 142 of the removal unit 140 are moved to their initial positions.
As shown in FIG. 1, the initial position of the transfer plate 110 is the position when the support base 132 is at the right end position on the base 136 and the elevating unit 120 is at the lower limit position. The initial position of the blade 142 of the removal unit 140 is the Z direction, that is, the vertical position when the lift unit 146 is at the upper limit position, and the support unit 150 of the transport unit 148 is closest to the X direction, that is, the direction perpendicular to the paper surface. The position when it is on the side.

  After the above preparatory operations are completed, the vacuum valve 26 in FIG. 1 is closed and the pressure valve 23 is opened to pressurize the coating liquid in the coating liquid storage unit 22 and pump the coating liquid to the inkjet head 10. When the pressure purge is performed, the coating liquid is discharged from all the nozzle holes 12. The coating liquid discharged from the nozzle hole 12 is partially collected while spreading on the nozzle hole exit surface 11 to form a plurality of coating liquid droplets. When the volume of the collected application droplets increases, a part of them naturally falls due to gravity. At the end of the pressure purge, the discharged coating liquid becomes a plurality of coating droplets 30 that remain irregularly on the nozzle hole outlet surface 11 in places and sizes (step of FIG. 4A).

  Next, the transfer unit 110 is moved by driving the conveyance unit 130 and stopped at the position where the leading edge 116 of the transfer plate 110 comes directly below the right end of the nozzle hole exit surface 11 near the end 15B. Then, the elevating unit 120 is driven to raise the transfer plate 110 so that the nozzle hole outlet surface 11 and the transfer surfaces 112A, B, and C of the transfer plate 110 are substantially parallel, and the gap amount between both surfaces is S. The raising of the transfer plate 110 is stopped (step of FIG. 4B).

  Subsequently, the conveyance unit 130 is driven again, and the transfer plate 110 is moved in the direction indicated by the arrow in the Y direction (from the right side to the left side of the paper surface), the nozzle hole outlet surface 11 of the inkjet head 10 and the transfer surfaces 112A, B, C. While the gap amount S is maintained during this time, the gap is moved at a constant speed. When the transfer plate 110 moves, the leading edge 116 comes into contact with the coating droplet 30 remaining in the vertical direction with a length equal to or greater than the gap amount S on the nozzle hole outlet surface 11, and the coating droplet 30 is then transferred to the nozzle hole. A liquid film 31 having a thickness S that extends into the entire transfer surface 112A is formed by entering and expanding into a parallel gap portion 119 having a gap amount S between the exit surface 11 and the transfer surface 112A by capillary action (FIG. 5). Step 4 (c)).

  In other words, the gap amount S is set to be narrower than the limit length at which the coating liquid can exist as droplets on the nozzle hole exit surface in a balance between wettability with the nozzle hole exit surface and its own weight. The limit length that can exist as droplets with respect to the nozzle hole exit surface of the coating liquid refers to the length that drops when the coating liquid becomes longer in the vertical direction. Therefore, it varies somewhat depending on the type of coating liquid and the state of the nozzle hole outlet surface.

  When the transfer plate 110 continues to move in the direction of the arrow, the liquid film 31 moves with the transfer plate 110 while being held in the transfer surface 112A. That is, the coating droplet 30 that was in the middle of the movement of the transfer plate 110 becomes a liquid film 31 and moves from the original position on the nozzle hole outlet surface 11, but the nozzle hole discharge port surface 11 is liquid repellent. Therefore, even if the liquid film 31 moves, a part of the liquid film 31 does not adhere to the nozzle hole outlet surface 11 and remains, and as a result, the coating liquid droplet 30 moves on the nozzle hole discharge port surface 11. I will let you.

  In the state where the liquid film 31 is formed on the entire transfer surface 112A, when a new coating droplet 30 comes into contact with the leading edge 116 by the movement of the transfer plate 110, the surface tension of the coating liquid that holds the liquid film 31 in the transfer surface 112A. Therefore, the coating droplet 30 cannot enter the parallel gap 119. Therefore, the coating droplet 30 moves as it is pushed by the transfer plate 110.

  Further, when it comes into contact with a new coating droplet 30, it gathers together with the coating droplet pressed by the transfer plate 110 to become a larger coating droplet 32, and a part of it moves in the direction of the arrow while being removed by natural fall. (Step (d) in FIG. 4).

  In this case, the application droplet 30 can be gathered in front of the moving direction of the leading edge 116 regardless of the size of the application droplet 30. That is, even if the amount of sag from the nozzle hole exit surface 11 is smaller than the gap amount S of the parallel gap portion 119, the small coating droplets may cause the liquid film 31 or the large coating liquid accompanying the movement of the transfer plate 110. As the droplets 32 move, they gather with the liquid film 31 and the large coating droplets 32. In other words, they are absorbed by the liquid film 31 and the large coating droplets 32.

  If the movement of the transfer plate 110 is further continued, the large coating liquid droplet 32 also moves on the resin plate 13 while the liquid film 31 is maintained in the parallel gap portion 119, and partially drops at the position of the end 15A of the inkjet head 10. I will give you. Then, the liquid film 31 is maintained in the parallel gap portion 119 formed between the resin plate 13 and the transfer surface 112A in the vicinity of the end portion 15A, while the liquid film 31 is in an open state above the transfer surface 112A. Remains as it is, and as a result, the coating liquid is transferred onto the transfer surface 112A (step in FIG. 5E).

  Further, when the movement of the transfer plate 110 is continued and the end edge 117 passes just below the end portion 15A and the groove 114A comes, the coating liquid is transferred to the entire transfer surface 112A, while a part of the remaining coating liquid remains. Drops in the groove 114A and collects, but the other coating liquid remains in the form of hanging below the resin plate 13 in the vicinity of the end portion 15A to form the end coating droplet 33 (step of FIG. 5 (f)).

  Further, when the transfer plate 110 continues to move and the transfer surface 112B, the groove 114B, and the transfer surface 112C pass immediately below the end 15A, the remaining end coating droplet 33 is transferred to the transfer surfaces 112B and C. The end coating liquid droplet 33 moves toward the transfer plate 110 by dropping toward the groove 114B, and no coating liquid remains on the nozzle hole outlet surface 11 of the inkjet head 10 or the resin plate 13. (Step (g) in FIG. 5).

  That is, the plurality of coating liquid droplets 30 that remain irregularly on the nozzle hole outlet surface 11 after the pressure purge to the ink jet head 10 are all transferred to the transfer plate 110 in a non-contact manner. Completely removed.

  Thereafter, the transfer plate 110 is continuously moved and stopped when the transfer surfaces 112A, B, and C come to a position immediately below the blade 142. Subsequently, the elevating unit 146 is driven to lower the blade 142 and bring it into contact with the X direction end portions of the transfer surfaces 112A, B, and C.

  Next, the conveyance unit 148 is driven while the blade 142 is in contact with the transfer surfaces 112A, B, and C, and the blade 142 is moved toward the back side in the X direction, that is, the direction perpendicular to the paper surface. All of the coating liquid transferred onto the transfer surfaces 112A, B, and C is removed. When the blade 142 reaches the end position in the X direction, the transport unit 148 is stopped and the lifting unit 146 is driven in the reverse direction to raise the blade 142 to the upper limit position. Thereafter, the transport unit 148 is also driven in the reverse direction, and the blade 142 is returned to the initial position in the X direction. In parallel with this, the elevating unit 120 is driven to lower the transfer plate 110, and then the transport unit 130 is driven to return the transfer plate 110 to the initial position in the Y direction to prepare for the next coating liquid removal operation.

  As described above, the coating liquid removing device for an inkjet head according to the present invention collects droplets of the coating liquid remaining between the nozzle hole outlet surface and the transfer plate to form a liquid film, and the liquid film is formed on the transfer plate. By moving and removing on the nozzle hole outlet surface, fine droplets can be reliably removed without damaging the nozzle hole outlet surface.

  The coating liquid removing apparatus and the coating liquid removing method of the present invention can be particularly preferably applied to a coating liquid having a viscosity of 5 to 20 mPa · s for an inkjet head.

  In the above-described operation for removing the coating liquid remaining on the inkjet head 10, it is preferable that the width W, which is the length in the X direction, of the transfer plate 110 is larger than the length in the X direction of the inkjet head 10. This is because when the width W of the transfer plate 110 is larger than the length of the inkjet head 10, that is, the resin plate 13 in the X direction, the coating liquid spreading to the entire area of the resin plate 13 can be received.

  In this embodiment, three transfer surfaces 112A, B, and C are arranged in the longitudinal direction of the transfer plate 110 by being separated by grooves 114A and B. However, any number of transfer surfaces 112A, B, and C may be arranged as long as there are two or more. Good. In this case, each transfer surface must be divided in the longitudinal direction by a groove. Since the transfer surfaces 112A, B, and C may have different lengths D1 and D2 or D3, there may be at least one pair of a transfer surface having a large area and a narrow transfer surface. .

  If the transfer surface is not separated in the longitudinal direction by grooves, it becomes one continuous transfer surface. If the coating liquid remaining on the nozzle hole exit surface 11 is transferred to one long transfer surface, not all of the remaining coating liquid can be transferred onto the transfer surface as shown in FIG. The liquid always remains in the vicinity of the end 15 </ b> A of the inkjet head 10 as the end coating droplet 33.

  If the transfer surface of the end coating droplet 33 is made very long in the longitudinal direction, it can be reduced to such an extent that practically no harm is caused, but it takes a very long time. On the other hand, when the end coated droplets 33 are transferred to a plurality of transfer surfaces divided in the longitudinal direction by grooves, a part of the end coated droplets 33 pulled on the transfer surface falls at the grooves and enters the grooves. As the number of encounters increases, the amount of decrease in the end coating droplets 33 also increases.

  Therefore, when the length of the transfer surface is made relatively short and a plurality of appropriate numbers of transfer surfaces and grooves are provided, the end coating droplets 33 can be eliminated in a shorter time. That is, it is preferable because the coating liquid remaining on the ink jet head 10 can be removed.

  In this embodiment, the groove is linearly provided in the width direction of the transfer plate. However, the present invention is not limited to this. For example, the groove may be provided slightly obliquely with respect to the width direction of the transfer plate.

  In addition, the Y-direction length D1 of the transfer surface 112A to which the coating liquid is first transferred is preferably 1/3 or more of the Y-direction length of the inkjet head 10. If the length of the inkjet head 10 is less than 1/3 of the length in the Y direction, the probability of not encountering the coating droplet 30 having a size larger than the gap amount S between the nozzle hole outlet surface 11 to the transfer surface 112A increases. This is because the liquid film 31 cannot be formed between the exit surface 11 and the transfer surface 112A, and as a result, the coating droplet 30 smaller than the gap amount S may not be absorbed or collected to be collected.

  On the other hand, for the transfer surfaces 112B and C onto which the coating liquid remaining on the inkjet head 10 is transferred after the transfer surface 112A, the Y-direction length D2 and D3 are preferably 1/5 of the length D1 of the transfer surface 112A. More preferably, it is 1/10 or less. As described above, it is the end coating droplet 33 that is transferred on the transfer surfaces 112B and C, and in order to quickly extinguish the end coating droplet 33, the length of the transfer surface is shortened, This is because it is better to increase the number of encounters with grooves that divide the transfer surface in the longitudinal direction.

  The Y-direction length L2 of the groove 114B following the transfer surface 112B to which the second residual coating solution is transferred is the second length L1 of the groove 114A following the transfer surface 112A to which the first residual coating solution is transferred. L1 / 2 or less is preferable. This is because the amount of the coating liquid falling in the groove 114B is always smaller than the amount of the coating liquid falling in the groove 114A. Therefore, the length of the coating liquid is shortened to shorten the time required to pass the groove, thereby shortening the coating liquid removing operation time. It is to do.

  The length L1 of the groove 114A in the Y direction is preferably 5 mm or more. If it is smaller than this, the edge coating droplet 33 may bridge between the transfer surface 112A and the transfer surface 112B and may not fall into the groove 114A. The depth H of the grooves 114A and B is preferably 1 mm or more. If it is smaller than this, the coating liquid that has fallen into the grooves 114A, B overflows the grooves 114A, B, and may reattach to the resin plate 13 and the nozzle hole outlet surface 11.

  The material of the transfer plate 110 may be any metal such as stainless steel, synthetic resin such as Teflon (registered trademark), ceramics, as long as it has chemical resistance to the coating liquid and does not swell. It is preferable that the material is more lyophilic than the resin plate 13 surrounding the nozzle hole outlet surface 11 and its periphery.

  Further, the gap amount S is set to be narrower than the limit length at which the coating liquid can exist as droplets on the nozzle hole outlet surface in a balance between wettability with the nozzle hole outlet surface and its own weight. More specifically, it is preferably 100 μm to 1 mm, more preferably 300 μm to 500 μm, based on the size of the coating droplet 30 remaining on the nozzle hole outlet surface 11. If it is larger than this range, the majority of the plurality of coating liquid droplets 30 remaining on the nozzle hole outlet surface 11 have a size equal to or smaller than the gap amount S, and the coating liquid droplets 30 that are not transferred to the transfer plate 110 are discharged from the nozzle hole outlet. It remains on the surface 11.

  Conversely, if it is small, there is a high risk that the transfer plate 110 and the nozzle hole exit surface 11 come into contact with each other and are damaged. Further, the moving speed in the Y direction when transferring the residual coating liquid on the transfer plate 110 is preferably 10 to 100 mm / s, more preferably 30 to 60 mm / s. If it is smaller than this range, it takes too much time to remove the coating liquid. On the other hand, if it is larger, more transfer surfaces and grooves are required to completely remove the remaining coating liquid, and the removal of the coating liquid is inefficient. This is because it takes time.

  Furthermore, the transfer plate 110 approaches the nozzle hole exit surface 11 with a gap amount S and starts moving in the Y direction, and travels a distance that the end side 117 of the transfer surface 112A passes through the end portion 15B. The end side 117 may return to a position immediately below the end 15B of the inkjet nozzle 10, and may be moved again toward the end 15A. The liquid film 31 is formed between the transfer surface 112A and the nozzle hole exit surface 11 after a while from the start of the movement of the transfer plate 110, due to the gap amount S near the end 15B. Although small coating droplets 30 remain, by returning the transfer plate 110 to the end portion 15B once the liquid film 31 is formed, the coating droplets 30 smaller than the gap amount S near the end portion 15B are also absorbed. This is because all coating droplets can be collected.

  In the present embodiment, the transfer plate is moved relative to the nozzle hole outlet surface. However, the nozzle hole outlet surface may be moved.

  In this embodiment, the removal unit 140 uses a blade 142 to remove the coating solution on the transfer plate 110. However, as another method, the coating solution on the transfer plate 110 is sprayed with a solvent solution and air. Any method can be used to move and remove the coating liquid on the transfer plate 110, such as a system that blows away the coating liquid, or a system that absorbs the coating liquid by moving it while pressing a cloth with good water absorption against the coating liquid on the transfer plate 110. May be used.

Example 1
The present invention will be specifically described below with reference to examples.
The coating liquid remaining on the nozzle hole outlet surface 11 of the inkjet head 10 was removed using the coating liquid removing apparatus 100 shown in FIG.

  As shown in FIG. 3, the inkjet head 10 was used in which the nozzle hole exit surface 11 was provided with three rows of nozzle holes 12 in a zigzag pattern with a Y direction pitch of 70.5 μm and a total of 512 pieces. From each nozzle hole 12, it was possible to intermittently discharge 40 pl of coating liquid per time by driving the piezoelectric element. As for the outer shape of the inkjet head 10, the length in the Y direction of the nozzle hole exit surface 11 is 45 mm, the length in the X direction is 4 mm, the length in the Y direction of the resin plate 13 is 60 mm, and the length in the X direction. Was 16 mm.

  In addition, as a liquid repellent layer, a polyimide resin layer having a thickness of 80 μm was provided on the nozzle hole outlet surface 11, and as a result, the nozzle hole outlet surface 11 protruded downward from the resin plate 13 into a convex shape of 80 μm. On the other hand, in the removal unit 140, a PET resin having a length of 80 mm in the Y direction, a length of 15 mm in the Z direction, and a thickness of 2 mm was used for the blade 142.

  The transfer plate 110 used in the coating liquid removing apparatus 100 was made of stainless steel, and was provided with three transfer surfaces 112A, B, and C partitioned in the longitudinal direction (Y direction) of the inkjet head 10. The length D1 of the transfer surface 112A = 30 mm, the length D2 of the transfer surface 112B = 2.5 mm, the length D3 of the transfer surface 112C = 2.5 mm, the length L1 of the groove 114A separating each transfer surface, L1 = 5 mm, and the groove 114B L2 = 2.5 mm, groove depth H = 5 mm, and width W = 30 mm, which is the length of the transfer plate 110 in the X direction.

  The coating liquid discharged from the inkjet head 10 was an R-color coating liquid having an R color pigment, a viscosity of 10 mPa · s, and a solid content concentration of 15%.

  First, the coating liquid supply apparatus 20 was operated, and 2000 μl of the R color coating liquid was discharged from the inkjet head 10 at a pressure of 0.05 MPa. The discharged R color coating liquid remained almost entirely on the nozzle hole exit surface 11 of the inkjet head 10. Then, the coating liquid removing apparatus 100 was operated to bring the transfer surfaces 112A, B, and C of the transfer plate 110 close to the nozzle hole outlet surface 11 so that the gap amount S was 300 μm.

  Subsequently, the transfer plate 130 was moved in the longitudinal direction (Y direction) of the inkjet head 10 at a moving speed of 30 mm / sec by the transport unit 130 to remove the coating liquid remaining on the nozzle hole outlet surface 11. As a result, all of the coating liquid remaining on the nozzle hole outlet surface 11 is transferred to the transfer surfaces 112A, B, and C of the transfer plate 110 or falls below, and the nozzle hole outlet surface 11 of the inkjet head 10 and the resin plate It was confirmed that no coating liquid remained on the surface of 13.

  The coating liquid transferred onto the transfer surfaces 112A, B, and C of the transfer plate 110 is slid at 100 mm / sec in the X direction after pressing the blade 142 against the transfer surfaces 112A, B, and C at a pressure of 0.05 MPa. Removed.

  After confirming that there was no remaining amount of coating liquid on the nozzle hole exit surface 11, the piezoelectric element was driven to discharge the coating liquid from the inkjet head 10 intermittently. As a result, it was confirmed that all nozzle holes 12 were not clogged and failed to be ejected such as bent flight, and normal ejection was possible.

(Example 2)
A color filter was manufactured using the coating liquid removing apparatus 100 and the inkjet head 10 of Example 1. By the previous process, on a non-alkali glass substrate of 360 x 465 mm and a thickness of 0.7 mm, each pixel has a width of 100 μm, a length of 300 μm, a black matrix width of 20 μm, and a liquid repellent surface. A grid-like black matrix substrate having the property was prepared.

  The liquid repellency of the black matrix was such that the contact angle with respect to the R color coating solution was 40 ° or more. The black matrix substrate is sucked and held on a suction stage (not shown) in FIG. 1, and while the suction stage is moved at 50 mm / s, 800 μl of R color coating liquid is discharged from the inkjet head 10 per pixel, and only the R color pixel is discharged. Was formed on the entire surface.

  Subsequently, G color pixels and B color pixels were formed using the G color coating liquid and the B color coating liquid sequentially under the same conditions. The R color coating solution is the same as in Example 1, the G color coating solution has a G color pigment, the viscosity is 12 mPa · s, the solid content concentration is 16%, the B color coating solution has a B color pigment, and the viscosity It was 11 mPa · s and the solid content concentration was 14%.

  In each R, G, and B color pixel formation, each time 30 substrates are applied, the inkjet head 10 is pressure purged at a pressure of 0.1 MPa, and 1000 μl of each application liquid is discharged to clean around the nozzle holes. It was. Subsequently, the remaining coating liquid was removed by operating the coating liquid removing apparatus 100 for the coating liquid remaining on the inkjet head 10 under the same conditions as in Example 1. After each color pixel is formed, pre-baking is performed at 100 degrees for 10 minutes. After all the R, G, and B color pixels are formed, baking is performed at 230 ° C. for 30 minutes, and finally, R, G having a thickness of 2 μm is formed. A color filter with B pixels could be obtained.

Further, this color filter was superposed on the substrate on which the TFT array was formed, and heated at 160 ° C. for 90 minutes while being pressurized in an oven to cure the sealing agent. After liquid crystal injection into this cell, the liquid crystal injection port was sealed with an ultraviolet curable resin. Next, a polarizing plate was attached to the outside of the two glass substrates of the cell, and the obtained cell was modularized to complete a liquid crystal display device. The obtained liquid crystal display device had no defects, and the chromaticity was uniform and satisfactory over the entire surface of the substrate.

1 is a schematic front view of a coating liquid removing apparatus 100 and an inkjet head 10 according to the present invention. 2 is a plan view of a nozzle hole outlet surface 11 of the inkjet head 10 as viewed from below. FIG. 2 is an enlarged front view of a transfer plate 110. FIG. FIG. 3 is a flowchart showing stepwise a state in which a coating liquid remaining on the inkjet head 10 is removed by a transfer plate 110. FIG. 3 is a flowchart showing stepwise a state in which a coating liquid remaining on the inkjet head 10 is removed by a transfer plate 110.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet head 11 Nozzle hole exit surface 12 Nozzle hole 13 Resin plate 14 Main body 15A, B End 20 Coating liquid supply apparatus 21 Pipe 22 Coating liquid storage part 23 Pressure valve 24 Pressure pipe 25 Pressure air source 26 Vacuum valve 27 Vacuum pipe 28 Vacuum source 29 Coating liquid 30 Coating droplet 31 Liquid film 32 Large coating droplet 33 End coating droplet 100 Coating liquid removing device 110 Transfer plate 112A, B, C Transfer surface 114A, B Groove 116 First side 117 End side 118 Transfer end side 119 Parallel gap 120 Lifting unit 130 Transport unit 132 Support base 134 Rail 136 Base 140 Removal unit 142 Blade 144 Blade mounting base 146 Lift unit 148 Transport unit 150 Support base 152 Rail 154 Waste liquid collection pan D1, D 2, D3 Length of transfer surfaces 112A, B, C in Y direction L1, L2 Length of grooves 114A, B in Y direction H Depth of grooves 114A, B W Transfer surfaces 112A, B, C and grooves 114A, B Width (length in X direction)

Claims (6)

A coating liquid removing device remaining on the nozzle hole exit surface of the inkjet head,
A transfer plate comprising a plurality of transfer surfaces separated by grooves,
Proximity means for approaching the transfer plate and the nozzle hole exit surface at a predetermined interval;
Moving means for moving the transfer plate while maintaining the predetermined interval with respect to the longitudinal direction of the nozzle hole outlet surface;
A coating solution removing apparatus comprising: The coating liquid removing apparatus according to claim 1, wherein the transfer surface of the transfer plate includes at least one set of transfer surfaces having different widths. The coating liquid removing apparatus according to claim 1, further comprising a removing unit that removes the coating liquid transferred to the transfer plate. A method for removing a coating liquid remaining on a nozzle hole exit surface of an inkjet head,
A step of bringing a transfer plate having a plurality of transfer surfaces separated by grooves close to a nozzle hole exit surface at a predetermined interval;
Moving the transfer plate while maintaining the predetermined interval with respect to the longitudinal direction of the nozzle hole exit surface;
The coating liquid removal method containing this. 5. The method for removing a coating liquid from an inkjet head according to claim 4, wherein the coating liquid remaining on the hole outlet surface of the inkjet head nozzle is transferred to the transfer plate, and then the coating liquid on the transfer plate is removed. . A color filter is manufactured by applying the coating liquid with the inkjet head after removing the residual coating liquid by using the inkjet head coating liquid removing method according to any one of claims 4 and 5. A method for producing a color filter characterized by the above.

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