JP2009248022A - Fluid transport apparatus and method of manufacturing optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently form a coating film uniform in thickness on a substrate. <P>SOLUTION: The fluid transport apparatus is provided with: a discharge means 10 for discharging a coating liquid on a substrate; a first storage means 20 for storing the coating liquid supplied to the discharge means; a second storage means 30 for storing the coating liquid sent to the first storage means; a pressurizing means 50 for pressurizing the inside of the first storage means and the inside of the second storage means; and a ventilation means 60 for communicating the inside of the first storage means and the inside of the second storage means with each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid feeding facility for applying a coating liquid onto a substrate. Moreover, this invention relates to the manufacturing method of an optical film provided with the application | coating process which apply | coats a coating liquid on a base material.

  A coating apparatus for coating a coating solution on a substrate is used in each manufacturing process of an optical film, a magnetic recording tape, an adhesive tape, a photographic printing paper, an offset plate material, a battery electrode plate, a fuel cell catalyst layer, and the like. .

  Examples of the coating method include a bar coater method, a reverse roll coater method, a gravure roll coater method, and a slot die coater method such as an extrusion coater. Among these, a slot die coater type coating apparatus using a slot die is frequently used because a thin layer can be coated at a higher speed than other systems.

  FIG. 2 shows a schematic configuration of a liquid feeding facility provided with a conventional slot die coater type coating apparatus. The flexible long web-shaped substrate 1 travels in the direction of arrow A along the backup roll 5. A slot die 110 is disposed opposite to the base material 1 supported by the backup roll 5. The supply tank 120 for storing the coating liquid and the slot die 110 are connected via a supply line 121. On the supply line 121, a supply pump 122 for supplying the coating liquid toward the die 110 is installed. The liquid feeding equipment further includes a replenishment tank 130 and a service tank 140 for storing the coating liquid. The supply tank 120 and the replenishment tank 130 are connected via a replenishment line 131. On the replenishment line 131, a replenishment pump 132 that feeds the coating liquid from the replenishment tank 130 to the supply tank 120 is installed. The replenishment tank 130 and the service tank 140 are connected via a liquid supply line 141. A liquid feed pump 142 for feeding the coating liquid from the service tank 140 to the replenishing tank 130 is installed on the liquid feed line 141.

  The coating liquid in the supply tank 120 is supplied to the slot die 110 through the supply line 121 by driving the supply pump 122, and is discharged toward the substrate 1 from the slot of the slot die 110. The coating solution applied on the substrate 1 forms the coating film 2. When the application liquid in the supply tank 120 decreases, the replenishment pump 132 is driven to replenish the supply tank 120 with the application liquid from the replenishment tank 130 through the replenishment line 131 as appropriate. Further, when the coating liquid in the replenishing tank 130 decreases, the liquid feeding pump 142 is driven to replenish the replenishing tank 130 with the coating liquid from the service tank 140 through the liquid feeding line 141.

  The base material 1 on which the coating film 2 is formed by such a slot die coater system is displayed on a display screen of an image display device such as a cathode ray tube display (CRT), a plasma display (PDP), a liquid crystal display (LCD), or the like. It is used as an optical film to be attached, and its demand is increasing year by year. The performance of the optical film used for such an application is greatly influenced by the thickness variation of the coating film 2. Therefore, in the field of optical films, a higher degree of uniformity in the thickness of the coating film 2 is required.

  One factor that affects the thickness of the coating film 2 is non-uniformity in the discharge amount of the coating liquid applied onto the substrate 1. For example, in the liquid feed facility equipped with the slot die coater type coating apparatus of FIG. 2, the change over time in the amount of coating liquid discharged from the slot die 110 onto the substrate 1 has a great influence on the thickness of the coating film 2. give. Therefore, in order to make the thickness of the coating film 2 obtained by the slot die coater method uniform, it is necessary to discharge a certain amount of coating liquid from the slot die 110 onto the substrate 1.

Patent Document 1 describes a coating method that suppresses fluctuations in the amount of coating liquid discharged onto a substrate by optimizing the slot width and slot length of the slot die. In Patent Document 2, when a coating liquid is fed to a slot die using a gear pump, the relationship between the liquid feeding volume per one rotation of the gear of the gear pump and the number of gear teeth is optimized. Describes a coating method that suppresses fluctuations in the amount of coating liquid fed to the slot die.
JP 2007-75797 A JP 2006-272129 A

  According to the coating method described in Patent Document 1, it is possible to suppress fluctuations in the amount of the coating liquid discharged onto the substrate by optimizing the shape of the slot die itself. However, no consideration has been given to suppressing fluctuations in the amount of coating liquid fed to the slot die. Therefore, fluctuations in the discharge amount of the coating liquid from the slot die cannot be sufficiently suppressed.

  Further, according to the coating method described in Patent Document 2, the variation in the amount of the coating liquid fed to the slot die can be suppressed to some extent by optimizing the specifications of the gear pump. However, because of the structure of the gear pump, the fluctuation of the liquid feeding volume cannot be completely eliminated, so that the pulsation of the coating liquid discharged from the slot die cannot be sufficiently suppressed.

  That is, in order to form a coating film having a uniform thickness on the substrate, a certain amount of coating solution is fed to the slot die and a certain amount of coating solution is discharged from the slot die onto the substrate. Although it is necessary, this has not been realized by the conventional coating method.

  Moreover, in order to cope with the enormous demand and cost reduction that have been increasing in recent years, it is desired to apply the coating liquid efficiently and continuously on the substrate.

  This invention is made | formed in view of the above-mentioned situation, and it aims at providing the liquid feeding equipment which can form the coating film of uniform thickness efficiently on a base material. Another object of the present invention is to provide an efficient method for producing an optical film in which a coating film having a uniform thickness is formed on a substrate.

  The liquid feeding equipment of the present invention is fed to the discharge means for discharging the coating liquid onto the substrate, the first storage means for storing the coating liquid to be sent to the discharge means, and the liquid to the first storage means. A second storage means for storing the coating liquid; a pressurizing means for pressurizing the interior of the first storage means and the interior of the second storage means; the interior of the first storage means and the interior of the second storage means And a ventilation means for communicating with each other.

  Moreover, the manufacturing method of the optical film of this invention is equipped with the process of apply | coating a coating liquid on a base material using said liquid feeding equipment of this invention.

  According to the liquid feeding equipment of the present invention, a coating film having a uniform thickness can be efficiently formed on a substrate.

  Moreover, according to the manufacturing method of the optical film of this invention, the optical film in which the coating film of uniform thickness was formed on the base material can be manufactured efficiently.

  In the liquid feeding facility of the present invention described above, it is preferable that the coating liquid discharge port of the second storage means is disposed at a higher position than the coating liquid discharge port of the first storage means. Thereby, since the coating liquid in a 2nd storage means can be liquid-fed in a 1st storage means using gravity, an installation can be simplified and cost-reduced.

  It is preferable that the bottom surface of the first storage means has an end plate shape. As a result, even when the amount of the coating liquid in the first storage means decreases, the flow rate change of the coating liquid can be reduced, so that the uniformity of the thickness of the formed coating film can be further improved. it can.

  Hereinafter, the present invention will be described in detail with reference to an embodiment thereof. However, the present invention is not limited to this one embodiment.

  FIG. 1 is a diagram showing a schematic configuration of a liquid delivery facility according to an embodiment of the present invention. This liquid feeding equipment is a slot die 10 as a discharge means for discharging a coating liquid onto a substrate 1 that is an object to be coated, and a supply as a first storage means for storing the coating liquid fed to the slot die 10. Tank 20, replenishment tank 30 as second storage means for storing the coating liquid fed to supply tank 20, and pressurization as pressurizing means for pressurizing the inside of supply tank 20 and the interior of replenishment tank 30 A source 50 and a ventilation line 60 as a ventilation means for communicating between the inside of the supply tank 20 and the inside of the replenishing tank 30 are provided.

  The slot die 10 discharges and applies the coating liquid supplied from the supply tank 20 via the supply line 21 onto the substrate 1. The configuration of the slot die 10 is not particularly limited. For example, the manifold 10a capable of retaining the coating liquid and the manifold 10a communicate with the coating liquid at the tip of the slot die 10 (the part facing the substrate 1). It is preferable to provide a guiding slot 10b. The tip of the slot 10b opens toward the substrate 1 so that the coating liquid can be discharged.

  A backup roll 5 is disposed facing the slot die 10. The backup roll 5 supports the base material 1 so that the distance between the coated surface of the base material 1 and the slot die 10 is constant, and conveys the base material 1 in the direction of arrow A by rotating.

  The substrate 1 is an object to which the coating liquid is applied by the liquid feeding facility of the present embodiment, and the coating film 2 made of the coating liquid is formed on the surface thereof. The specific form is not particularly limited, but for example, a flexible web-like material (film, sheet, etc.) can be used. The material is not particularly limited. For example, resin, specifically, cellulose ester (for example, triacetyl cellulose, diacetyl cellulose), polyamide, polycarbonate, polyester (for example, polyethylene terephthalate, polyethylene naphthalate), polystyrene, norbornene series Resin, amorphous polyolefin, etc. can be used. Among these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable.

  The supply tank 20 is a tank for storing the coating liquid supplied to the slot die 10. A supply tank valve 22 that can be opened and closed is installed at the discharge port of the coating liquid below the supply tank 20.

  The supply line 21 is a liquid pipe that connects the supply tank valve 22 and the slot die 10 and guides the coating liquid stored in the supply tank 20 to the slot die 10. On the supply line 21, a filter 23, a constant flow valve 24, a flow meter 25, and a supply valve 26 are installed. The filter 23 is a filter that removes foreign matters such as aggregates in the coating liquid. The constant flow valve 24 is a flow rate adjusting valve that includes a throttle and sets the flow rate of the coating liquid to a desired value. The flow meter 25 measures the flow rate (flow rate or flow rate per unit time) of the coating liquid flowing through the supply line 21. The supply valve 26 is an openable / closable valve that sets whether or not the coating liquid can flow into the slot die 10. The filter 23, the constant flow valve 24, the flow meter 25, and the supply valve 26 can be installed as necessary, and some or all of them can be omitted. In addition to the above, the supply line 21 may further include a pressure gauge for measuring the pressure of the coating liquid.

  The replenishment tank 30 is a tank for storing the application liquid so that the supply liquid can be replenished to the supply tank 20 when the remaining amount of the application liquid in the supply tank 20 decreases. A replenishment tank valve 32 that can be opened and closed is installed at the discharge port of the coating liquid below the replenishment tank 30. An exhaust pipe 33 provided with an exhaust valve 34 is connected to the replenishing tank 30. When the exhaust valve 34 is opened, the pressurized air in the replenishing tank 30 can be discharged to the outside through the exhaust pipe 33.

  The replenishment line 31 is a liquid pipe that connects the replenishment tank valve 32 and the supply tank 20 and guides the coating liquid stored in the replenishment tank 30 to the supply tank 20.

  The pressurization source 50 is a device that generates and supplies compressed air having a desired pressure. The configuration of the pressurization source 50 is not particularly limited.

  The pressurization line 51 connected to the pressurization source 50 branches into the first pressurization line 51a and the second pressurization line 51b in the middle, and the first pressurization line 51a is connected to the supply tank 20 and the second pressurization line 51a. The pressurizing line 51 b is connected to the replenishing tank 30. The pressurization line 51, the first pressurization line 51a, and the second pressurization line 51b are gas pipes that send the compressed air generated by the pressurization source 50 to the supply tank 20 and the replenishment tank 30. A first pressure valve 52a for adjusting the pressure in the supply tank 20 is installed on the first pressure line 51a, and the pressure in the replenishing tank 30 is set on the second pressure line 51b. A second pressurizing valve 52b for adjustment is installed.

  The ventilation line 60 is a gas pipe that connects the supply tank 20 and the replenishment tank 30. A vent valve 61 that can be opened and closed is installed on the vent line 60. When the ventilation valve 61 is opened, the inside of the supply tank 20 and the inside of the replenishing tank 30 communicate with each other via the ventilation line 60, so that the pressures in both the tanks 20, 30 are substantially the same, and both the tanks 20, 30 are connected. Air movement between them becomes easy.

  The liquid feeding facility of this embodiment further includes a service tank 40. The service tank 40 is a tank for storing the application liquid so that the application liquid can be replenished to the replenishment tank 30 when the remaining amount of the application liquid in the replenishment tank 30 decreases. The coating liquid is first supplied to the service tank 40. A service tank valve 42 that can be opened and closed is installed at the discharge port of the coating liquid below the service tank 40.

  The service tank valve 42 and the replenishment tank 30 are connected via a liquid feed line 41. The liquid feed line 41 is a liquid pipe that guides the coating liquid stored in the service tank 40 to the replenishment tank 30.

  In the supply tank 20, the replenishment tank 30, and the service tank 40, a liquid meter for detecting the storage amount of the internal coating liquid, a stagnation, thickening, sedimentation, etc. of the stored coating liquid, if necessary In order to prevent this, a stirring blade or the like for stirring the coating solution may be provided.

  In the liquid feeding facility of the present embodiment, as will be described later, the coating liquid in the supply tank 20 is pushed out toward the slot die 10 using the pressure of the compressed air generated by the pressurization source 50. Therefore, when the area of the liquid surface of the coating liquid in the supply tank 20 changes depending on the storage amount (that is, the liquid level) of the coating liquid, the extrusion pressure of the coating liquid changes accordingly. Therefore, it is preferable that the bottom surface of the supply tank 20 has an end plate shape. Thereby, compared with the case where it is conical, for example, the change in the pushing force of the coating liquid when the remaining amount of the coating liquid decreases becomes small. The end plate shape is a shape generally used for the end face of the storage tank, and refers to a shape whose cross section can be approximated by a parabolic curve, for example. Furthermore, it is preferable that the bottom surface of the replenishing tank 30 into which the compressed air generated by the pressurization source 50 is introduced has a mirror plate shape for the same reason.

  Further, in the liquid feeding facility of the present embodiment, the coating liquid in the replenishing tank 30 is fed to the supply tank 20 via the replenishment line 31 using gravity. For this purpose, the liquid level of the coating liquid in the replenishment tank 30 is higher than the liquid level of the coating liquid in the supply tank 20 regardless of the amount of the coating liquid stored in the replenishment tank 30 and the supply tank 20, respectively. It is preferable to install the replenishment tank 30 and the supply tank 20 with a height difference between them so that they are positioned. For example, by disposing the discharge port of the coating liquid below the replenishment tank 30 at a position higher than the discharge port of the coating liquid below the supply tank 20, the liquid level of the coating liquid in the replenishment tank 30 is adjusted to the supply tank 20. It is possible to make the position higher than the liquid level of the coating liquid inside.

  Further, the coating liquid in the service tank 40 is fed to the replenishing tank 30 through the liquid feeding line 41 using gravity. For this purpose, the liquid level of the coating liquid in the service tank 40 is higher than the liquid level of the coating liquid in the replenishing tank 30 regardless of the amount of the coating liquid stored in the service tank 40 and the replenishing tank 30, respectively. It is preferable to install the service tank 40 and the replenishment tank 30 with a height difference between them so that they are positioned. For example, by disposing the discharge port of the coating liquid in the lower part of the service tank 40 at a position higher than the discharge port of the coating liquid in the lower part of the replenishing tank 30, the liquid level of the coating liquid in the service tank 40 is replenished. It is possible to make the position higher than the liquid level of the coating liquid inside.

  Operation | movement of the liquid feeding equipment of this embodiment comprised as mentioned above is demonstrated.

  First, a case where the coating liquid is applied onto the substrate 1 in a state where the coating liquid is stored in the supply tank 20 will be described. In this case, first, the pressurization source 50 is operated, the first pressurization valve 52a is opened, and the compressed air generated by the pressurization source 50 is supplied through the pressurization line 51 and the first pressurization line 51a. 20 into. Next, the supply tank valve 22 and the supply valve 26 are opened. Then, the coating liquid in the supply tank 20 is supplied from the supply tank 20 to the supply line 21 by the pressure of the compressed air generated by the pressurization source 50 (in some cases, gravity acting on the coating liquid is superimposed on this). Pumped. The coating liquid sequentially passes through the filter 23, the constant flow valve 24, the flow meter 25, and the supply valve 26 and flows into the slot die 10. The coating liquid sequentially passes through the manifold 10a and the slot 10b in the slot die 10 and is discharged from the tip of the slot 10b. The coating liquid discharged from the slot die 10 is applied onto the base material 1 traveling in the direction of arrow A by the backup roll 5 to form the coating film 2.

  The flow rate of the coating liquid flowing through the supply line 21 can be measured using the flow meter 25. Moreover, you may measure the thickness of the coating film 2 formed on the running base material 1 using a non-contact thickness meter (not shown), for example. Based on the measured flow rate of the coating liquid and / or the thickness of the coating film 2, the pressure of the compressed air generated by the pressurizing source 50 and / or the opening of the throttle of the constant flow valve 24 may be adjusted. Thereby, the thickness of the coating film 2 can be managed uniformly with higher accuracy. The above adjustment may be performed automatically using a control device (not shown), or may be performed manually by an operator. For example, when the amount of the coating liquid in the supply tank 20 is reduced, the extrusion pressure toward the slot die 10 generated by the weight of the coating liquid is reduced, so that the thickness of the coating film 2 may be reduced. In such a case, for example, the pressure of the compressed air generated by the pressure source 50 may be controlled so that the pressure applied to the coating liquid in the supply tank 20 is increased.

  When the coating film 2 is formed as described above, it is preferable that all of the replenishment tank valve 32, the exhaust valve 34, the second pressurization valve 52b, the ventilation valve 61, and the service tank tank valve 42 are closed.

  In the conventional liquid feeding facility shown in FIG. 2, in order to supply the coating liquid to the slot die 110, the supply pump 122 installed on the supply line 121 connecting the supply tank 120 and the slot die 110 is used. As the supply pump 122, for example, a gear pump, a diaphragm pump, a plunger pump, or the like is used. Since these pumps have a structure that periodically sends a constant amount of coating liquid, pulsation occurs in the coating liquid flowing into the slot die 110, and thus the pulsation of the coating liquid discharged from the slot die 110 is completely eliminated. It was difficult to eliminate it. As a result, it was difficult to obtain a coating film 2 having a constant thickness, such as unevenness in the coating film 2 formed on the substrate 1. Further, when an optical film is manufactured using a gear pump as the supply pump 122, for example, using a coating liquid containing an ultraviolet curable resin, the gear of the gear pump is fixed because the ultraviolet curable resin is cured in the gear pump. In some cases, the liquid could not be sent. On the other hand, in the liquid feeding equipment of the present embodiment, a pressurizing source 50 that pressurizes the internal space of the supply tank 20 is used as a drive source for supplying the coating liquid to the slot die 10. Therefore, it is not necessary to install a pump on the supply line 21 that connects the supply tank 20 and the slot die 10. Therefore, pulsation hardly occurs in the coating liquid flowing into the slot die 10 and the coating liquid discharged from the slot die 110. As a result, the coating film 2 having a uniform thickness can be formed on the substrate 1.

  The pressure applied to the coating liquid in the supply tank 20 by the compressed air generated by the pressurization source 50 may be appropriately set according to the physical properties (for example, viscosity) of the coating liquid, a desired flow rate, etc. It is preferably 0.01 MPa to 1.0 MPa, more preferably 0.03 MPa to 0.5 MPa. If the pressure is smaller than the lower limit value of this numerical range, the force for feeding the coating liquid to the supply line 21 is small, so it may be difficult to control the liquid feeding amount. If the pressure is larger than the upper limit of this numerical range, the force for feeding the coating liquid to the supply line 21 is large, so the amount of liquid feeding increases and it is difficult to control the amount of coating liquid discharged from the slot die 10. It may become.

  Next, an operation when the remaining amount of the coating liquid in the supply tank 20 is reduced while the coating liquid is being applied on the traveling substrate 1 as described above will be described. It is assumed that a sufficient amount of coating liquid is stored in the replenishing tank 30. In this case, first, the second pressurization valve 52b is opened, and the compressed air generated by the pressurization source 50 is sent into the replenishment tank 30 through the pressurization line 51 and the second pressurization line 51b. Next, the ventilation valve 61 is opened, and the pressure in the supply tank 20 and the pressure in the replenishing tank 30 are set to substantially the same pressure via the ventilation line 60. Then, the replenishment tank valve 32 is opened. Then, the coating liquid in the replenishment tank 30 moves into the supply tank 20 through the replenishment line 31 by the action of gravity. When a predetermined amount of coating liquid is stored in the supply tank 20, the replenishment tank valve 32, the ventilation valve 61, and the second pressurization valve 52b are closed. During the above operation, the exhaust valve 34 is closed. This is for maintaining the pressure in the replenishing tank 30 in a predetermined pressurized state.

  In the conventional liquid delivery equipment shown in FIG. 2, when the remaining amount of the coating liquid in the supply tank 120 is reduced, the replenishing pump 132 is driven to supply the coating liquid in the replenishing tank 130 through the replenishment line 131. To the supply tank 120. Since the supply of the coating liquid to the slot die 110 is performed by the supply pump 122, it is possible to replenish the coating liquid into the supply tank 120 while applying the coating liquid onto the substrate 1. On the other hand, in the liquid feeding equipment of this embodiment, the supply of the coating liquid to the slot die 10 uses the pressure of the compressed air introduced into the supply tank 20. Therefore, when the supply liquid in the supply tank 20 is replenished using the replenishment pump 132 as in the prior art, the pressure fluctuation in the supply tank 20 occurs, and the coating film 2 having a uniform thickness cannot be formed. . Therefore, it is necessary to stop the application of the coating liquid on the substrate 1 every time it becomes necessary to replenish the coating liquid into the supply tank 20, so that continuous production is difficult and the production efficiency is extremely deteriorated.

  In the present embodiment, as described above, the second pressurization valve 52b is opened to pressurize the replenishment tank 30 in the same manner as the supply tank 20, and the vent valve 61 is opened to supply the supply tank 20 and the replenishment tank 30. Are communicated with each other via a ventilation line 60. Accordingly, when the coating liquid in the replenishment tank 30 moves into the supply tank 20 through the replenishment line 31, the pressure in the supply tank 20 hardly changes, so that the thickness of the coating film 2 formed on the substrate 1 is also increased. Almost no change. Therefore, it is possible to replenish the application liquid into the supply tank 20 while applying the application liquid on the base material 1, thereby enabling continuous production and preventing deterioration in production efficiency.

  In addition to the first pressurization line 51a and the second pressurization line 51b, a ventilation line 60 that connects the supply tank 20 and the replenishment tank 30 is provided, so that the supply tank 20 and the replenishment tank 30 are connected to each other. Air can easily move through the ventilation line 60. Therefore, the coating liquid in the replenishing tank 30 can be easily moved into the supply tank 20 using gravity.

  Next, an operation when the remaining amount of the coating liquid in the replenishing tank 30 is reduced will be described. In this case, first, the exhaust valve 34 is opened with the refill tank valve 32, the second pressurization valve 52b, and the ventilation valve 61 closed. Next, the service tank tank valve 42 is opened. Then, the coating liquid in the service tank 40 moves into the replenishing tank 30 through the liquid feeding line 41 by the action of gravity. In parallel with the application liquid flowing into the replenishing tank 30, the air in the replenishing tank 30 is discharged to the outside through the exhaust line 33. When a predetermined amount of coating liquid is stored in the replenishing tank 30, the service tank valve 42 and the exhaust valve 34 are closed.

  Thus, when the replenishment tank 30 is replenished with the coating liquid, the replenishment tank valve 32, the second pressurization valve 52b, and the ventilation valve 61 are closed, so the supply liquid is supplied by flowing into the replenishment tank 30. The pressure in the tank 20 is not affected at all. Accordingly, the coating liquid can be replenished into the replenishing tank 30 while coating the coating liquid on the substrate 1.

  The replenishment of the coating liquid to the service tank 40 may be performed with the service tank valve 42 closed. Also in this case, since the pressure in the supply tank 20 is not affected by the flow of the coating liquid into the service tank 40, the coating liquid is replenished into the service tank 40 while coating the coating liquid on the substrate 1. can do.

  As described above, according to the liquid feeding facility of the present embodiment, the coating liquid is pumped to the slot die 10 by applying pressure to the coating liquid in the supply tank 20 by the pressurization source 50. The coating film 2 having a certain thickness can be formed on the substrate 1. Further, the inside of the replenishing tank 20 is further pressurized by the pressurizing source 50, and the supply tank 20 and the replenishing tank 30 are communicated through the ventilation line 60, thereby forming the coating film 2 having a constant thickness on the substrate 1. However, the coating liquid in the replenishing tank 30 can be moved into the supply tank 20. Therefore, continuous production is possible.

  In particular, when an optical film such as an optical filter of a display panel such as a liquid crystal display or a plasma display is manufactured by using the liquid feeding equipment of this embodiment, a highly accurate optical film without uneven coating thickness can be obtained with high productivity. It can be manufactured at low cost. Therefore, it is possible to prevent a decrease in optical image quality of the display panel, and to reduce the cost of the display panel.

  The above embodiment is merely an example, and the present invention can be modified in various ways.

  For example, the coating apparatus according to the above embodiment employs a so-called backup roll support system in which the coating liquid is discharged from the slot die 10 onto the base material 1 supported by the backup roll 5. It is not limited. For example, a predetermined tension is applied between two rolls arranged in parallel, the base material 1 is bridged, and a slot die 10 is arranged at a substantially intermediate position between the two rolls so as to face the base material 1. Thus, a so-called tension support system in which the coating liquid is discharged from the slot die 10 onto the substrate 1 can be employed.

  In the above embodiment, one layer of the coating film 2 is formed on one surface of the substrate 1, but two or more layers of the coating film can also be formed. For this purpose, a plurality of slot dies similar to those in the above embodiment may be arranged in the running direction of the substrate 1, a slot die having a plurality of pairs of manifolds and slots may be used, or A combination of these may also be used.

  In the above embodiment, the service tank 40 and the liquid supply line 41 can be omitted. In this case, the supply of the coating liquid to the liquid feeding facility may be performed with respect to the replenishment tank 30 with the replenishment tank valve 32, the second pressurization valve 52b, and the ventilation valve 61 closed. Also in this case, since the pressure in the supply tank 20 is not affected by the flow of the coating liquid into the replenishing tank 30, the coating liquid is replenished into the replenishing tank 30 while applying the coating liquid onto the substrate 1. can do.

  In the above embodiment, the liquid feeding from the service tank 40 to the replenishing tank 30 via the liquid feeding line 41 is performed using gravity, but a pump is installed on the liquid feeding line 41, The coating liquid may be fed by the driving force of the pump. In this case, since there is no restriction on the installation height of the replenishment tank 30 and the service tank 40, most of the existing equipment can be diverted to realize the liquid feeding equipment of the present invention.

  Although there is no restriction | limiting in particular in the utilization field of the liquid feeding equipment of this invention, It can utilize as liquid feeding equipment provided with the coating apparatus of the slot die coater system which apply | coats a coating film on a base material. It can utilize especially when manufacturing the optical film which uses the resin film which has flexibility as a base material.

FIG. 1 is a diagram showing a schematic configuration of a liquid delivery facility according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of an example of a conventional liquid feeding facility.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Coating film 5 Backup roll 10 Slot die 10a Manifold 10b Slot 20 Supply tank 21 Supply line 22 Supply tank valve 23 Filter 24 Constant flow valve 25 Flowmeter 26 Supply valve 30 Replenishment tank 31 Replenishment line 32 Replenishment tank valve 33 Exhaust Pipe 34 Exhaust valve 40 Service tank 41 Liquid supply line 42 Service tank valve 50 Pressure source 51 Pressure line 51a First pressure line 51b Second pressure line 52a First pressure valve 52b Second pressure valve 60 Ventilation line 61 Ventilation valve

Claims (5)

A discharge means for discharging the coating liquid onto the substrate;
First storage means for storing a coating liquid fed to the discharge means;
Second storage means for storing the coating liquid fed to the first storage means;
Pressurizing means for pressurizing the interior of the first storage means and the interior of the second storage means;
Ventilation means for communicating between the inside of the first storage means and the inside of the second storage means.   The liquid feeding facility according to claim 1, wherein the coating liquid discharge port of the second storage unit is disposed at a position higher than the coating liquid discharge port of the first storage unit.   The liquid feeding facility according to claim 1 or 2, wherein a bottom surface of the first storage means has a mirror plate shape.   The inside of the first storage means and the inside of the second storage means are pressurized by the pressurizing means, and the inside of the first storage means and the inside of the second storage means are connected via the ventilation means. While supplying the coating liquid from the second storage means to the first storage means at substantially the same pressure, the coating liquid in the first storage means is sent to the discharge means and discharged from the discharge means. The liquid feeding equipment according to any one of claims 1 to 3, wherein the coating is applied on a substrate.   The manufacturing method of an optical film provided with the process of apply | coating a coating liquid on a base material using the liquid feeding equipment in any one of Claims 1-4.

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