JP2015116543A - Storage device, storage method, coating applicator and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that a highly viscous paste-like liquid can be stored without entangling air bubbles.SOLUTION: A storage device comprises: a storage part 11 having a storage space SP capable of storing a paste-like liquid; a supply pipeline 28 whose one end is an opening 282a opening toward the storage space SP and where a liquid supplied from outside is continuously discharged from the opening 282a and supplied to the storage space SP; and position control means 12 to raise the opening 282a corresponding to the raise of a liquid level in the storage space SP.

Description

  The present invention relates to an apparatus and method for storing a paste-like liquid, and an apparatus and method for performing application using the stored liquid.

  As a technique for forming a wiring pattern on the surface of a substrate such as a glass substrate or a solar cell substrate or forming an active material layer on the surface of a current collector, a paste-like liquid containing a wiring material or an active material is applied to the substrate. There is something to apply. For example, the coating apparatus described in Patent Document 1 manufactures a battery electrode by applying a paste containing an active material and a conductive material to a support by a die coating method. In this technique, in order to prevent the agglomeration of the paste on the distribution path and maintain a good fluidity state, the circulation channel is provided between the tank for storing the paste and the nozzle for applying the paste to the application target. Is formed, and the paste is circulated to always give shear.

JP 2013-004400 A (for example, FIG. 1)

  In the above-described conventional technology, there is a possibility that bubbles may be involved when the paste sent through the pipe is returned to the tank. In other words, due to its high viscoelasticity in paste-like liquids, when it flows down from the pipe into the tank, it does not become a continuous liquid flow, and may fall in a lump as an ambient air. It is taken in and becomes air bubbles and remains in the liquid. The same is true when the liquid is first injected into the empty tank.

When bubbles are mixed in the paste-like liquid, there is a problem that the flow rate becomes unstable due to pressure loss when the liquid is pumped, or a coating defect occurs in the formed pattern. For a low-viscosity liquid, defoaming can be performed by, for example, leaving it under reduced pressure. In particular, for example, in a high-viscosity liquid having a viscosity of about 100 Pa · s or more at a shear rate of 10 s ⁻¹ , bubbles are temporarily removed. No technology has been established that can effectively remove it when it is involved.

  Patent Document 1 does not describe in detail the internal structure of the tank for storing the paste. There is no mention of the problem of bubbles in the paste. As described above, it is necessary to devise such that bubbles are not involved when the paste-like liquid is poured into the tank, but this point has not been considered at all in the prior art.

  This invention is made | formed in view of the said subject, and makes it the 1st objective to provide the technique which can store a high-viscosity paste-like liquid, without entraining a bubble. A second object is to provide a coating technique to which this storage technique is applied.

  In one aspect of the storage device according to the present invention, in order to achieve the first object, a storage portion having a storage space capable of storing a paste-like liquid, and an opening having one end opening toward the storage space A supply pipe that continuously discharges the liquid supplied from the outside through the opening and supplies the liquid to the storage space, and a position for raising the opening in response to a rise in the liquid level in the storage space. Control means.

  Moreover, one aspect of the storage method according to the present invention is a storage method for storing a paste-like liquid in a storage part having a storage space capable of storing the liquid, in order to achieve the first object, Disposing an opening at one end of a supply pipe to which the liquid is supplied from the outside toward the storage space, and discharging the liquid from the opening, and the liquid stored in the storage space and the supply pipe A step of raising the opening in accordance with a rise in the liquid level of the liquid stored in the storage space while maintaining a state in which the liquid in the inside is continuous.

  In the invention configured as described above, the high-viscosity paste-like liquid can be stored in the storage space without entraining bubbles. The reason is as follows. In pasty liquids with high viscoelasticity, the liquid discharged from the opening at one end of the pipe grows below the opening as a rod-like or spherical lump, and falls downward when it cannot support its weight. To do. Therefore, if the difference in height between the opening and the liquid level of the liquid stored in the storage space is larger than a certain level, the liquid mass intermittently falls from the opening and bubbles are generated in the stored liquid. Will be involved.

  In the present invention, the opening can be raised as the liquid level gradually rises in the storage space as the liquid is injected into the storage space. Therefore, the difference in height between the opening and the liquid level can be reduced regardless of the amount of liquid to be stored. Thereby, injecting the liquid from the opening in a state in which the liquid discharged from the opening and the liquid stored in the storage space are made continuous to prevent entrainment of bubbles due to the above-described intermittent drop. Can do. And by raising the opening according to the rise of the liquid level accompanying the increase in the storage amount, while maintaining a continuous liquid flow from the opening to the liquid level in the storage space, the generation of bubbles is prevented. The liquid can be continuously stored in the storage space.

  That is, in the storage device according to the present invention, it is preferable that the position control means raises the opening while maintaining a state where the liquid stored in the storage space and the liquid in the supply pipe are continuous. By doing so, it is possible to effectively prevent bubbles generated by the liquid falling intermittently.

  For example, you may further provide the detection means which detects the position of the liquid level in the storage space. The height of the liquid level in the storage space can be estimated without directly measuring, for example, if the amount of liquid supplied from the supply pipe and the time are known. However, if the position of the liquid level is directly detected, the position of the opening of the supply pipe can be more accurately controlled according to the detection result.

  For example, the position control means may be configured to position the position of the opening in the vertical direction above the position of the liquid level. In the state where the opening is submerged in the stored liquid, the liquid that stays in an irregular shape around the opening can cause bubbles. Such a problem can be avoided by positioning the opening above the liquid level and dropping the liquid flow discharged from the opening toward the liquid level.

Further, for example, the height difference between the opening and the liquid surface may be maintained at 0 to 50 mm. According to the knowledge of the inventors of the present application, when the opening is provided away from the liquid surface as described above, the falling liquid flow is interrupted to increase the possibility of generating bubbles. In particular, the above distance is suitable for a liquid having a viscosity of about 100 Pa · s to 300 Pa · s at a shear rate of 10 s ⁻¹ .

  Further, for example, the position control means may be configured to raise the opening while maintaining a constant height difference from the liquid level. Due to the high viscoelasticity of the liquid, it is considered that the liquid flow is not interrupted even if the height of the opening from the liquid surface fluctuates slightly. However, the height of the opening should be such that the height is constant. Most preferably, it is controlled.

  Moreover, in order to achieve the second object, one aspect of the coating apparatus according to the present invention is connected to the storage means having the same configuration as any of the storage apparatuses described above, and the storage means, An output pipe for taking out the liquid stored in the storage means; and a discharge means connected to the output pipe for discharging the liquid toward the application target.

  Moreover, in one aspect of the coating method according to the present invention, in order to achieve the second object, the liquid stored in the storage space is stored while the liquid is stored in the storage unit by the storage method. A step of sending the liquid toward the discharge means; and a step of discharging the liquid that has been sent out from the discharge means and applying the liquid onto an object to be applied.

  In the invention configured as described above, the liquid stored so as not to include bubbles by the above-described storage technique is sent out from the storage space and applied to the application target. Therefore, there is no variation in the coating amount, and it is possible to perform coating without defects.

  In this case, for example, a flow means for flowing the liquid into the output pipe may be interposed in the output pipe. By doing so, it becomes possible to deliver a stable amount of liquid to the ejection means.

  Further, for example, a configuration having a reflux path for returning the liquid to the storage space from the downstream side of the circulation means in the liquid circulation direction may be employed. When the liquid has thixotropic properties (thixotropic properties), if the liquid stays in a state where application is not performed, the viscosity of the liquid increases, which may hinder subsequent liquid flow. By providing a path for circulating the liquid, it is possible to prevent an increase in viscosity due to stagnation by constantly circulating the liquid even when application is not performed.

  In this case, for example, the reflux path may be connected to the supply pipe, and the liquid to be refluxed may flow into the storage space from the opening of the supply pipe. According to such a configuration, both the liquid supplied from the outside and the liquid flowing through the circulation path can flow into the storage space from the opening via the supply pipe. Therefore, it is possible to switch between external liquid supply and internal liquid circulation without interrupting the liquid flow from the opening.

  According to the present invention, the liquid flow is interrupted by storing the liquid in a state in which the flow of the liquid continuously discharged from the opening from the supply pipe is made continuous with the liquid stored in the storage space. It is possible to prevent entrainment of bubbles in the liquid.

It is a figure which shows one Embodiment of the coating device provided with the storage device concerning this invention. It is a figure which shows typically the example of the paste application | coating in this coating device. It is side surface sectional drawing which shows the more detailed structure of a tank. It is a flowchart which shows the application | coating operation | movement in this embodiment. It is the 1st figure showing typically the state of each part under operation. It is a 2nd figure which shows typically the state of each part in operation | movement.

  FIG. 1 is a view showing an embodiment of a coating apparatus provided with a storage device according to the present invention. The coating device 1 is a device that applies a paste-like coating liquid to a sheet-like substrate S conveyed by a roll-to-roll method. For example, a battery electrode such as a lithium ion secondary battery is manufactured. It can be used for.

  The coating apparatus 1 includes a tank 10 that stores therein a coating liquid to be coated, and a nozzle 50 that discharges the coating liquid supplied from the tank 10, and is provided between the tank 10 and the nozzle 50. The applied liquid in the tank 10 is sent out toward the nozzle 50 by the liquid feeding system 20 (described later), and is discharged from a discharge port provided at the tip of the nozzle 50.

  A substrate S on which the coating liquid is applied is disposed by the transport unit 70 at a position facing the nozzle 50. Specifically, the long sheet-shaped substrate S wound in a roll is set on the supply roller 71 of the transport unit 70, and one end of the substrate S is wound on the winding roller 72. Yes. When the take-up roller 72 rotates in the direction of the arrow Dr in the figure, the substrate S is unwound from the supply roller 71, conveyed in the direction of the arrow Ds, and taken up by the take-up roller 72. That is, the transport unit 70 has a function as a means for holding the base material S that is an application target and a function as a means for transporting the same. In this way, the nozzle 50 is arranged so as to face the surface of the base material S stretched over the supply roller 71 and the take-up roller 72. Therefore, the coating liquid discharged from the nozzle 50 is applied to the surface of the substrate S. By transporting the base material S in the direction of the arrow Ds, the coating liquid can be applied to the base material S while the nozzle 50 is scanned and moved relative to the base material S.

  Here, for example, an active material layer is laminated on the surface of the current collector layer by using a conductive sheet such as a metal functioning as a current collector as the substrate S and using a paste containing an active material as a coating liquid. It is possible to manufacture a battery electrode.

  FIG. 2 is a diagram schematically showing an example of paste application in this application apparatus. On the lower surface 51 of the nozzle 50 disposed opposite to the substrate S conveyed in the direction of the arrow Ds, a plurality of discharge ports 52 each discharging a coating liquid are arranged in the width direction of the substrate S perpendicular to the conveyance direction Ds. They are arranged side by side at intervals. The high-viscosity paste-like coating liquid continuously discharged from each discharge port is deposited on the surface of the substrate S, and then conveyed in the direction of the arrow Ds as the substrate S moves. As a result, a line pattern P of the coating liquid continuously extending along the transport direction Ds is formed on the substrate S. The coating apparatus 1 can also form a continuous pattern along the transport direction Ds of the substrate S, and temporarily discharge the coating liquid from each discharge port 52 as shown in FIG. It is also possible to form an intermittent pattern P in the transport direction Ds by stopping the operation.

  The cross-sectional shape of the pattern depends on the opening shape of each discharge port 52. In particular, when a high-viscosity coating liquid is used, it is possible to form a pattern having a cross-sectional shape that maintains the opening shape of the discharge port 52 almost as it is. is there. As a result, it is possible to form a pattern having a high ratio of height to width, that is, a high aspect ratio. When the substrate S functions as a current collector and the line pattern formed by the coating liquid contains an active material, a line pattern having a high aspect ratio was formed on the current collector surface by the active material. A battery electrode having a structure can be produced. Since the electrode having such a structure has an active material layer having a large surface area with respect to the amount of active material used, a battery having good high-speed charge / discharge characteristics can be formed.

  Of course, it is possible to form a relatively wide pattern on the surface of the substrate S by making each discharge port into a wide opening shape or having a slit shape as described in Patent Document 1. is there. Also in this case, an electrode having a high-density and thick active material layer can be manufactured by making the coating solution have a high viscosity. Thereby, a battery with a large capacity can be configured.

In order to form such a pattern with excellent dimensional accuracy, it is necessary to stably discharge a highly viscous coating liquid from the nozzle 50 at a small flow rate. The configuration of the liquid feeding system 20 in the coating apparatus 1 for enabling this will be described with reference to FIG. 1 again. In addition, the viscosity assumed in the coating liquid applied to this coating apparatus 1 is about 100 Pa · s to 300 Pa · s at a shear rate of 10 s ⁻¹ .

  The liquid feeding system 20 in the coating apparatus 1 has an output pipe 21 having one end connected to the bottom of the tank 10, a pump 22 and a flow meter 23 arranged in the middle, and an input to the other end of the output pipe 21. One of the input ports is connected to the other end of the circulation pipe 26 and the three-way valve 24 to which the port is connected, the application pipe 25 and the circulation pipe 26 each having one end connected to the two output ports of the three-way valve 24. A three-way valve 27, an input pipe 28 connected to the output port of the three-way valve 27, and a supply pipe 29 connected to the other input port of the three-way valve 27. In addition, the coating apparatus 1 includes a control unit 30 that controls the liquid feeding system 20 to discharge a predetermined amount of coating liquid from the nozzle 50.

  The pump 22 is for circulating the coating liquid through the liquid feeding system 20, and is preferably capable of delivering a highly viscous coating liquid at a stable flow rate. As such a pump, for example, a screw pump can be used, and for example, a MONO pump which is a kind of single screw pump can be suitably applied. The operation of the pump 22 is controlled by the control unit 30, and the control unit 30 controls the pump 22 based on the flow rate of the coating liquid in the output pipe 21 detected by the flow meter 23, thereby applying the coating liquid in the liquid feeding system 20. Adjust the flow rate.

  The three-way valve 24 is controlled by the control unit 30 and selectively opens a coating path where the output pipe 21 and the coating pipe 25 are connected and a circulation path where the output pipe 21 and the circulation pipe 26 are connected. The application pipe 25 is connected to the nozzle 50. When the three-way valve 24 opens the application path connecting the output pipe 21 and the application pipe 25 in accordance with a control command from the control unit 30, the pressure supply from the tank 10 is performed. The applied coating liquid is supplied to the nozzle 50 via the coating pipe 25 and is applied to the sheet S that is the object to be coated.

  On the other hand, when the three-way valve 24 opens a circulation path that connects the output pipe 21 and the circulation pipe 26 in accordance with a control command from the control unit 30, the coating liquid pumped from the tank 10 passes through the circulation path. To the tank 10. More specifically, a flow path connecting the circulation pipe 26 and the input pipe 28 is always opened by the three-way valve 27 controlled by the control unit 30, and the circulation pipe 26 is connected from the output pipe 21 via the three-way valve 24. The coating liquid flowing into the tank 10 returns to the tank 10 via the three-way valve 27 and the input pipe 28.

  When the high-viscosity coating liquid has thixotropic properties (thixotropic properties), it is necessary to always apply a shearing force to the coating liquid in order to maintain the fluidity of the coating liquid. Except when supplying the coating liquid to the nozzle 50, the coating liquid is circulated through the circulation flow path so that a shearing force is applied to the coating liquid to maintain a highly fluid and low-viscosity state. it can.

  The replenishment pipe 29 is connected to an external replenishment tank (not shown), and when the coating liquid in the tank 10 is applied to the sheet S and consumed, the remaining amount is reduced by the three-way valve 27 and the input pipe 28. Is opened. As a result, the replenishing coating liquid is supplied from the external replenishing tank to the tank 10 and the amount of the coating liquid in the tank 10 is recovered. The control unit 30 controls the three-way valve 27 and replenishes the application liquid from the external replenishment tank as necessary so that the fluctuation of the liquid amount in the tank 10 falls within a predetermined range. The replenished coating liquid flows into the tank 10 from the input pipe 28 in the same manner as the coating liquid circulating in the circulation path.

  FIG. 3 is a side sectional view showing a more detailed structure of the tank. The tank 10 has a tank housing 11 having a storage space SP in which the coating liquid can be stored. The inside of the tank housing 11 has a cylindrical shape with the substantially vertical direction as an axis and the bottom portion squeezed into a conical shape, and its internal cross-sectional area is substantially constant in the vertical direction at the top of the tank and gradually increases at the bottom. It is getting smaller. An output pipe 21 is connected to the bottom surface 11b.

  On the other hand, an opening 11c is provided at the center of the upper surface 11a of the tank casing 11, and the input pipe 28 extends from the outside of the tank 10 toward the storage space SP through the opening 11c. The input pipe 28 includes a pipe having resistance and flexibility with respect to the components of the coating liquid, for example, a flexible pipe 281 made of a stainless steel flexible tube, and a nozzle 282 having a discharge port 282a connected to the lower end thereof. I have. The coating liquid that circulates in the circulation pipe 26 or is supplied from the outside through the replenishment pipe 29 is sent into the tank casing 11 through the input pipe 28, and downwards from the discharge port 282 a toward the storage space SP. And continuously discharged. The opening sectional area of the discharge port 282a is smaller than the sectional area of the tank 10 in the horizontal plane.

  The nozzle 282 is supported by the support block 121 of the nozzle lifting mechanism 12 with the discharge port 282a facing downward. The nozzle support mechanism 12 further includes a ball screw mechanism 122 and a motor 123. A ball screw 122a of the ball screw mechanism 122 is connected to the rotation shaft of the motor 123 and is inserted through the opening 11c so as to extend in a substantially vertical direction. On the other hand, a support block 121 is fixed to a nut 122b engaged therewith. The motor 123 is fixed to the tank casing 11 by a fixing member (not shown).

  When the motor 123 is actuated in response to the control signal from the control unit 30, the ball screw 122a rotates and the nut 122b moves up and down, and the support block 121 moves up and down along with this, so that the nozzle 282 moves up and down. Thereby, the discharge port 282a at the lower end of the nozzle 282 can be moved up and down in the vertical direction in the storage space SP. In the following description, when it is necessary to make a distinction, the nozzle 282 connected to the input pipe 28 and provided in the tank 10 is referred to as a “supply nozzle”, and the nozzle 50 connected to the application pipe 25 is referred to as an “application nozzle”. There is.

  Further, the storage space SP in the tank 10 is provided with a liquid level sensor 13 for detecting the position of the liquid level of the coating liquid stored in the tank 10. As the liquid level sensor 13, any liquid level sensor can be used as long as it can detect the position of the liquid level in the vertical direction, for example, based on various measurement principles such as an ultrasonic type, a float type, a capacitance type, an electromagnetic type, and an optical type. Can be used. Further, the liquid level may be optically imaged and its position may be detected, or the liquid level position may be detected in combination with an index such as a scale provided on the tank inner wall surface. . The detection result by the liquid level sensor 13 is given to the control unit 30 and used for operation control of each part by the control unit 30.

  Next, the coating process in the coating apparatus of this embodiment will be described. In this coating process, the coating liquid from the outside is introduced into the tank 10 from the empty state where the coating liquid is not contained in the tank 10, and this is discharged from the nozzle 50 and applied to the sheet S as the coating object. It is processing of. This process is realized by the control unit 30 controlling each part of the apparatus based on a control program given in advance to perform a predetermined operation.

  FIG. 4 is a flowchart showing the coating operation in this embodiment. 5 and 6 are diagrams schematically showing the state of each part during operation. First, the nozzle raising / lowering mechanism 12 is operated when the tank 10 is empty, and as shown in FIG. 5A, the replenishing nozzle 282 is positioned so that the discharge port 282a is at the lowest position in the movable range. (Step S101). At this time, the gap G0 between the discharge port 282a and the bottom surface of the tank 10 is preferably 50 mm or less.

  Next, a replenishment path from the replenishment pipe 29 to the output pipe 28 is opened, and reception of the coating liquid supply from the external replenishment tank is started (step S102). As a result, as shown in FIG. 5B, the continuous discharge of the coating liquid L is started from the discharge port 282a of the replenishing nozzle 282, and the high-viscosity coating liquid L is bar-shaped from the replenishing nozzle 282 toward the tank bottom. To form a liquid column. After the liquid column reaches the bottom surface of the tank, the coating liquid spreads horizontally along the bottom surface.

  After the tip of the coating liquid L reaches the bottom surface of the tank, as shown in FIG. 5 (c), the vertical position of the liquid surface La of the coating liquid L stored at the bottom of the tank 10, that is, the liquid level height, Detected by the liquid level sensor 13 (step S103). Then, as shown by the upward arrow in FIG. 5 (c), the replenishing nozzle 282 is raised according to the height of the liquid level La (step S104), and the liquid level in the vertical direction as shown in FIG. 5 (d). The position of the replenishing nozzle 282 is controlled so that the distance G between La and the discharge port 282a maintains a substantially constant value. The distance G at this time is preferably 0 mm to 50 mm, and is more preferably greater than 0, that is, a state where the discharge port 282a is above the liquid level La.

  In a state where the discharge port 282a is submerged in the liquid stored in the tank 10, a new coating liquid is ejected into the liquid, so that the liquid that stays in an irregular shape around the discharge port 282a is a bubble. It can be a cause. In addition, when bubbles are mixed in the discharged coating liquid, it is expected that the bubbles are exposed to the surface of the liquid flow and disappear when the coating liquid is discharged to the external space. Such an effect cannot be obtained in a state where the liquid is submerged in the liquid. Further, once the lower surface of the nozzle 282 comes into contact with the liquid level La, the coating liquid remaining on the lower surface of the nozzle 282 may cause a new stay even if the nozzle 282 and the liquid surface are separated later. Therefore, it is preferable that the discharge port 282a is located above the liquid level La.

  By raising the replenishment nozzle 282 as the liquid level La rises as described above, the distance G between the liquid level La and the discharge port 282a can be kept substantially constant. As a result, the coating liquid L stored in the tank 10 and the coating liquid in the nozzle 282 are integrated into the tank 10 through the coating liquid discharged from the discharge port 282a, while being continuously integrated. Can be stored. Therefore, it is possible to prevent entrainment of bubbles caused by the application liquid intermittently falling into the tank 10 from the replenishing nozzle 282.

  The injection of the coating liquid is continued until the liquid level La of the coating liquid stored in the tank 10 reaches a predetermined minimum line Lmin (NO in step S105). When the liquid level La is equal to or higher than the lowest line Lmin (YES in step S105), if the liquid level La is equal to or lower than the highest line Lmax set above the lowest line Lmin (YES in step S106), the injection is continued as it is. On the other hand, if the maximum line Lmax is exceeded (NO in step S106), the injection of the coating liquid is stopped (step S107). During this time and thereafter, the detection of the liquid level by the liquid level sensor 13 and the position control of the replenishing nozzle 282 based on the detection will be continued. Thereby, the distance G between the liquid level La and the discharge port 282a of the replenishing nozzle 282 is always maintained regardless of the height of the liquid level La.

  When a coating liquid having a height equal to or higher than the minimum line Lmin is stored in the tank 10, the coating liquid is applied to the sheet S that is the object to be coated. That is, as shown in FIG. 6A, a coating path from the output pipe 21 through the coating pipe 25 to the coating nozzle 50 is established, and the pump 22 circulates the coating liquid in the output pipe 21 to thereby apply the coating nozzle. The coating liquid is discharged from 50 and applied to the sheet S (step S108). Note that the output pipe 21 may be in a liquid-tight state by opening a circulation path in advance and circulating the coating liquid.

  The application is continued until it is time to finish the application (step S110). During this time, the injection of the coating liquid from the external supply tank may be continued, but if the liquid surface height exceeds the maximum line Lmax (NO in step S106), the injection of the coating liquid is stopped (step S106). S107). Further, when the coating liquid is consumed by coating and the liquid level is lowered to be below the minimum line Lmin (YES in step S109), the replenishment path is reopened (step S111), and the process returns to step S102 to return the coating liquid. Resume injection.

  According to such a process, as shown in FIG. 6 (a), the application is performed while receiving the supply of the replenishment coating liquid from the external replenishment tank, and the external replenishment is performed as shown in FIG. 6 (b). There may be a situation where the application is performed without receiving. In any case, the amount of the application liquid supplied to the application nozzle 50 is stabilized by the pump 22, and the application to the sheet S can be performed stably. Further, the amount of liquid in the tank 10 is always maintained such that the liquid level is between the lowest line Lmin and the highest line Lmax. If the flow rate of the coating liquid replenished from the outside is made larger than the flow rate of the coating liquid taken out from the output pipe 21, the situation where the replenishment cannot catch up with the consumption of the coating liquid will not occur. The application timing is not limited by the timing. Since the replenishment is performed without including bubbles, the bubbles are not included in the coating liquid delivered to the coating nozzle 50, the coating can be performed with a stable coating amount, and the occurrence of coating defects is also prevented.

  When the necessary application is completed (YES in step S110), the application path is closed and the circulation path is opened by the three-way valve 24 (step S121). Thereby, the coating liquid sent out from the pump 22 is sent to the circulation path from the output pipe 21 to the circulation pipe 26. At this time, if the replenishment path is opened by the three-way valve 27, it is closed, and a circulation path from the output pipe 21 to the input pipe 28 via the circulation pipe 26 is opened. Therefore, as shown in FIG. 6C, the coating liquid sent out by the pump 22 and flowing through the circulation path is returned into the tank 10 via the input pipe 28.

  The flow of the coating liquid discharged from the discharge port 282a of the replenishing nozzle 282 is switched from that due to the coating liquid replenished from the outside to that due to the coating liquid refluxing the circulation path. Also at this time, since the height of the discharge port 282a from the liquid level La is properly maintained, the coating liquid does not fall intermittently from the discharge port 282a to generate bubbles. Further, by continuing the circulation of the coating liquid even when the coating is not performed, an increase in the viscosity of the coating liquid due to the stay is prevented, and when the coating is continuously performed, the coating liquid is quickly discharged from the coating nozzle 50. It is possible. While the coating liquid is circulated, the amount of liquid does not increase or decrease, and the liquid level is maintained between the lowest line Lmin and the highest line Lmax during this time.

  While the application is not performed in this manner, the circulation of the application liquid is continued, and when it is necessary to apply again (YES in step S122), the process returns to step S106. Accordingly, the application liquid can be supplied to the application nozzle 50 and newly applied while replenishing the application liquid as necessary. If no new application is required (NO in step S122), the process ends.

  As described above, in this embodiment, the high-viscosity paste-like coating liquid L corresponds to the “liquid” of the present invention, and the tank 10 functions as the “reservoir” of the present invention. The input pipe 28 functions as the “supply pipe” of the present invention, and in particular, the discharge port 282a of the replenishing nozzle 282 functions as the “opening” of the present invention. Further, the nozzle lifting mechanism 12 and the control unit 30 function as “position control means” of the present invention. Further, the liquid level sensor 13 functions as the “detecting means” of the present invention. And these tank 10, nozzle raising-lowering mechanism 12, liquid feeding system 20, etc. are united, and comprise the "storage device" of this invention.

  Further, in the coating apparatus 1 of this embodiment, the tank 10, the nozzle elevating mechanism 12, the liquid feeding system 20, and the like function as a “storage unit” of the present invention, and the output pipe 21 and the nozzle (coating nozzle) 50. Respectively function as “output piping” and “discharge means” of the present invention. The pump 22 functions as the “circulation means” of the present invention, and the circulation path connecting the output pipe 21, the circulation pipe 26 and the input pipe 28 corresponds to the “return path” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the MONO pump is used as the pump 22, but other types of pumps that can deliver a highly viscous fluid may be used. Applicable pumps include a hydraulic cylinder pump, a drum pump, and a flanger pump. It is also possible to use other types of screw pumps such as a uniaxial pump, a biaxial pump, and a screw pump other than the MONO pump.

  In the above embodiment, the three-way valve 27 switches the path for replenishing the coating liquid from the external replenishing tank and the path for circulating the coating liquid inside, but the storage device and the coating apparatus according to the present invention are It is not limited to what makes a circulation path a component. That is, the circulation path may not be provided, and the present invention can be applied even if the replenishment path and the circulation path are independent.

  In the above-described embodiment, the replenishment nozzle 282 is moved up and down in accordance with the fluctuation of the liquid level in the tank 10 so that the height of the discharge port 282a from the liquid level La is maintained constant. However, in the case of a particularly high-viscosity liquid, even if the distance between the liquid level La and the discharge port 282a varies slightly, the liquid column connecting the coating liquid in the input pipe 28 and the liquid level La is not immediately interrupted. Absent. Therefore, when the gap between the discharge port 282a and the liquid level La is within a predetermined appropriate range, the nozzle 282 is not raised or lowered, and the nozzle 282 is raised or lowered only when a gap fluctuation exceeding the appropriate range occurs. It may be.

  Moreover, in the said embodiment, although the nozzle 282 attached to the front-end | tip of the flexible piping 281 is raised / lowered by the ball screw mechanism 122, the gap control of the discharge outlet 282a and the liquid level La is performed, but the position of a discharge outlet ( The structure of the piping and the lifting mechanism for changing the height) is not limited to these, and any structure can be used.

  Moreover, although the operation from the state in which the tank 10 is empty has been described for the coating process of the above embodiment, even when starting from a state in which a certain amount of coating liquid is stored, the liquid level at that time is By determining the initial position of the replenishing nozzle 282 based on this, it is possible to perform the same processing. Moreover, although the said embodiment can perform simultaneously the replenishment of the coating liquid to the tank 10, and the application | coating to the application target object by the application | coating nozzle 50, these may be performed separately. For example, it may be configured to fill a tank with a predetermined amount of coating liquid, perform the coating, suspend the coating after completion of the coating, or when the remaining amount of liquid is low, and replenish the coating liquid Good.

  Moreover, in the said embodiment, although the liquid level height of the coating liquid in the tank 10 is always detected by the liquid level sensor 13, you may detect intermittently and the liquid level height is detected directly. Instead, the height of the liquid level is indirectly reflected in the nozzle position by moving the nozzle up and down based on information related to the position of the liquid level, such as the inflow and outflow amount of the coating liquid, for example. Also good.

  Moreover, the said embodiment incorporates the "storage device" of this invention in the coating device 1, Comprising: As the "storage device" of this invention, the structure for apply | coating the stored liquid to a coating target object. It is not what you need.

  Moreover, although the coating device 1 of this embodiment is a device which manufactures the electrode for a battery by apply | coating the coating liquid containing an active material material to a collector, this invention is a storage device for the purpose different from this, The present invention can also be applied to a coating apparatus. For example, by applying a coating liquid containing a conductive material, a collector electrode is formed on the photoelectric conversion layer to manufacture a solar cell, for example, a glass substrate for various display devices, etc. The present invention can also be applied to a forming apparatus, and a storage device according to the present invention may be provided on a path for supplying a coating liquid to these coating apparatuses.

  Furthermore, although this embodiment is an application device which applies the application liquid discharged from the nozzle 50 to the sheet S, the liquid is not limited to the one that is circulated for the purpose of application to the application object as described above. It is possible to apply the present invention to various liquid circulation devices through which liquid is circulated for the purpose.

  The present invention is particularly preferably applicable to the purpose of storing a highly viscous liquid in a storage space without generating bubbles.

1 coating device 10 tank (reservoir, reservoir)
12 Nozzle lifting mechanism (position control means)
13 Liquid level sensor (detection means)
21 Output piping 22 Pump (distribution means)
26 Circulation piping (reflux path)
28 Input piping (supply piping)
29 Supply piping 30 Control unit (position control means)
50 Application nozzle (Discharging means)
70 Transport Unit 282 Supply Nozzle 282a (Supply Nozzle) Discharge Port (Opening)
L Coating liquid (liquid)
S sheet (object to be coated)

Claims (12)

A storage section having a storage space capable of storing a paste-like liquid;
One end is an opening that opens toward the storage space, and a supply pipe that continuously discharges the liquid supplied from the outside and supplies the liquid to the storage space;
A storage device comprising: position control means for raising the opening in response to a rise in the liquid level in the storage space.   The storage device according to claim 1, wherein the position control unit raises the opening while maintaining a state in which the liquid stored in the storage space and the liquid in the supply pipe are continuous.   The storage device according to claim 1, further comprising detection means for detecting a position of the liquid level in the storage space.   The storage device according to any one of claims 1 to 3, wherein the position control means positions the position of the opening in a vertical direction above the position of the liquid level.   The storage device according to any one of claims 1 to 3, wherein a difference in height between the opening and the liquid level is 0 to 50 mm.   The storage device according to any one of claims 1 to 5, wherein the position control means raises the opening while maintaining a constant height difference from the liquid level. Reservation means having the same configuration as the storage device according to any one of claims 1 to 6,
An output pipe connected to the storage means to take out the liquid stored in the storage means;
An application apparatus comprising: discharge means connected to the output pipe for discharging the liquid toward an application target.   The coating apparatus according to claim 7, wherein a flow means for flowing the liquid into the output pipe is interposed in the output pipe.   The coating apparatus according to claim 8, further comprising a reflux path for refluxing the liquid to the storage space from a downstream side of the circulation unit in the liquid circulation direction.   The coating apparatus according to claim 9, wherein the reflux path is connected to the supply pipe, and the liquid that flows back flows into the storage space from the opening of the supply pipe. In a storage method for storing paste-like liquid in a storage part having a storage space capable of storing liquid,
Disposing an opening at one end of a supply pipe to which the liquid is supplied from the outside toward the storage space, and discharging the liquid from the opening;
While maintaining the state in which the liquid stored in the storage space and the liquid in the supply pipe are continuous, the opening is formed according to the rise of the liquid level of the liquid stored in the storage space. And a step of raising the storage method. A step of delivering the liquid stored in the storage space toward the discharge means while storing the liquid in the storage unit by the storage method according to claim 11;
And a step of discharging the delivered liquid from the discharge means and applying the liquid onto an object to be applied.

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