JP2001321709A - Apparatus and method for coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus which can apply a coating solution thinly on a base material by using capillarity, eliminate a liquid tank for sinking a nozzle, and accelerate the contact of the coating solution. SOLUTION: The nozzle 14 having a capillary gap 16 the upper end part of which is made a discharge opening 18 for a coating solution and a coating solution tank 32 for supplying the coating solution to the capillary gap of the nozzle 14 are provided. By deciding the height of the coating solution in the gap 16 based on the height of the solution in the tank 32, the base material W traveling forward/backward from the discharge opening 18 of the gap 16 is coated with the solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a method for coating a substrate with a coating liquid.

[0002]

2. Description of the Related Art Recently, liquid crystal display devices and the like have become widespread, and it has become necessary to apply a coating liquid to a glass plate of this liquid crystal display device and a protective plate attached to the glass substrate.

As a method of applying a coating liquid to such a substrate such as a glass substrate, a coating apparatus utilizing a capillary phenomenon has been proposed (JP-A-8-224528, JP-A-6-224528).
-343908).

In this coating apparatus, a nozzle provided with a capillary gap is submerged inside a liquid tank filled with a coating liquid, and when coating is performed, the nozzle is raised to bring the nozzle close to the lower surface of the substrate. The coating liquid is applied to the lower surface of the substrate by contacting the coating liquid through the capillary gap.

[0005]

The coating apparatus having the above-mentioned structure has an effect that the coating liquid can be thinly applied to the substrate because the capillary phenomenon is utilized.

However, in this coating apparatus,
Since it is necessary to fill the liquid tank with the coating liquid and submerge the nozzle therein, it is necessary to discard the coating liquid filled in the liquid tank after the coating is completed. However, the coating liquid used for the liquid crystal display device is very expensive, and it is necessary to effectively use this coating liquid at all.

Further, since the nozzle is submerged in the liquid tank, when the nozzle is protruded from the liquid tank, the coating liquid attached to the periphery of the nozzle is solidified, and this portion needs to be cleaned. There is also a problem that when the nozzle is submerged in the liquid tank, the solidified coating liquid becomes an impurity.

In addition, when the coating liquid is brought into contact with the capillary gap, a problem arises in that it takes a long time for the liquid to come in contact with the coating liquid because the capillary phenomenon is utilized.

In view of the above problems, the present invention makes it possible to apply a coating liquid thinly to a substrate by utilizing the capillary phenomenon, eliminate the need for a liquid tank for submerging a nozzle, and increase the speed of liquid contact. An object of the present invention is to provide a coating apparatus that can be used.

[0010]

According to a first aspect of the present invention, there is provided a nozzle extending in the left-right direction having a capillary gap having an upper end serving as a coating liquid discharge port, and coating the capillary gap of the nozzle. A tank of a coating liquid for supplying a working liquid is provided, and a liquid height of the capillary gap is determined based on a liquid height of the coating liquid in the tank. A coating apparatus characterized in that a coating liquid is applied to a substrate traveling in a direction.

According to a second aspect of the present invention, the tank is provided so as to move up and down relatively to the nozzle, and the tank is moved up and down to move the liquid height in the capillary gap up and down. The coating apparatus according to claim 1, wherein

The invention according to claim 3 is the coating apparatus according to claim 2, wherein the tank is provided so as to be vertically moved by a motor relative to the nozzle.

According to a fourth aspect of the present invention, there is provided the coating apparatus according to the second aspect, wherein the tank is manually moved up and down relative to the nozzle.

The invention according to claim 5 is characterized in that the base material is a long base material, and a backup roll for conveying the base material in the front-rear direction is arranged above the nozzle. It is a coating device of 2-4.

According to a sixth aspect of the present invention, the base material is a plate-shaped base material, and a suction table for adsorbing the plate-shaped base material on the lower surface and transporting the base material in the front-rear direction is arranged above the nozzle. The coating apparatus according to claim 2, wherein the coating apparatus is used.

The invention according to claim 7 is characterized in that a pumping means for pumping the coating liquid to the capillary gap is provided in the course of supplying the coating liquid from the tank to the capillary gap of the nozzle. The coating device according to claim 2, wherein:

The invention according to claim 8 provides a nozzle extending in the left-right direction having a capillary gap having an upper end serving as a coating liquid discharge port, and supplying the coating liquid to the capillary gap of the nozzle. A coating solution provided with a tank of a working liquid, and a pumping means for pumping the coating liquid to the capillary gap in the middle of a path for supplying the coating liquid from the tank to the capillary gap of the nozzle; In the method, a coating liquid is applied to a substrate traveling in the front-rear direction by the following steps. A first step of arranging the nozzle such that a distance between a discharge port of the nozzle and a lower surface of the substrate is equal to a coating thickness of a coating liquid; A second step in which the coating solution is pressure-fed to the capillary gap by the pressure feeding means, and the coating solution is brought into contact with the lower surface of the substrate from the discharge port. This is a third step of applying a coating liquid from the discharge port in a state of being in contact with the lower surface of the base material.

According to a ninth aspect of the present invention, there is provided a nozzle extending in the left-right direction having a capillary gap having an upper end serving as a coating liquid discharge port, and supplying the coating liquid to the capillary gap of the nozzle. This is a coating method of a coating apparatus provided with a tank for a working liquid, in which a coating liquid is applied to a substrate traveling in the front-rear direction in the following steps. A first step of arranging the nozzle such that a distance between a discharge port of the nozzle and a lower surface of the substrate is equal to a coating thickness of a coating liquid; A second step in which the coating liquid is pressure-fed to the capillary gap by increasing the liquid height of the tank, and the coating liquid is brought into contact with the lower surface of the base material from the discharge port. This is a third step of applying a coating liquid from the discharge port in a state of being in contact with the lower surface of the base material.

According to a tenth aspect of the present invention, in the third step, the traveling speed of the base material is initially caused to travel at a basic speed,
A step of applying a coating liquid to the lower surface of the base material by gradually increasing the liquid height of the tank, thereby gradually increasing the traveling speed from the basic speed. Item 10. A coating method of the coating device according to item 8 or 9.

[0020]

[Operation] A case of applying a coating liquid to a substrate using the coating apparatus of the present invention will be described.

In the first step, the distance between the discharge port of the nozzle and the lower surface of the substrate is adjusted to the thickness of the coating liquid while the substrate is transported in the front-rear direction by the backup roll or the suction table. Arrange the nozzle.

In the second step, the coating liquid is pressure-fed by the pressure-feeding means, or the coating liquid is pressure-fed by raising the liquid level of the tank, and the coating liquid is brought into contact with the lower surface of the base material.

In the third step, a coating liquid is applied while being in contact with the lower surface of the substrate. In this case, the traveling speed of the base material is initially run at the basic speed, and by gradually increasing the liquid height of the tank, the running speed is gradually increased from the basic speed, so that the lower surface of the base material is A coating liquid may be applied.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

The coating apparatus 10 of this embodiment is for coating a long substrate with a coating liquid. For example, a coating liquid is applied to a synthetic resin film such as polyethylene terephthalate (PET) to form an anti-reflection plate or a protective film used in a liquid crystal cell of a liquid crystal display device. Is 0.01 μm to 5 μm.

(Configuration of Coating Apparatus) FIG.
FIG.

First, the substrate W is transported forward by the backup roll 12 rotating in one direction.

Below the backup roll 12,
A nozzle 14 for applying a coating liquid is provided on the lower surface of the base material W.

The nozzle 14 has a beak-shaped upper portion, and a capillary gap 16 is provided along the left-right direction. The upper end of the capillary gap 16 becomes a discharge port 18 for the coating liquid. ing.

The nozzle 14 can be moved up and down as a whole by a vertically moving device 20 composed of an air cylinder or a motor disposed below the nozzle 14 (from a dotted line to a solid line in FIG. 1).

An overflow tank 22 for supplying a coating liquid is provided outside the nozzle 14. That is, the screw rod 26 is rotatably disposed in the vertical direction on the support portion 24 fixed to the wall of the nozzle 14.
6 is provided with a rack 28. The overflow tank 22 is attached to the rack 28.
The screw rod 26 is rotatable by a motor 30 with a speed reducer. When the motor 30 is driven, the screw rod 26 rotates, and the rack 28, that is, the overflow tank 22 moves up and down with respect to the nozzle 14. Further, since the support portion 24 is fixed to the nozzle 14, the nozzle 14
Is moved up and down by the vertical movement device 20, the overflow tank 22 is also moved up and down.

A tank 32 for storing a coating liquid is provided inside the overflow tank 22, and the upper surface of the tank 32 is open. The coating liquid overflowing from this tank 32 has a structure that accumulates on the bottom surface of the overflow tank 22.

A supply pipe 34 is provided as a path for supplying the coating liquid from the bottom of the tank 32 to the side or front of the nozzle 14. In the middle of the supply pipe 34, a stop valve 36 and a pressure-feed device 38 for the coating liquid are provided in this order from the tank 32 side.

The stop valve 36 shuts off the coating liquid passing through the supply pipe 34.

The pressure feeding device 38 comprises a suck back, a belofrom valve, a piston valve or a cylinder.
4 is to feed the coating liquid in the direction of the capillary gap 16 by pressure.

A discharge pipe 40 is provided from the bottom of the overflow tank 22, and the discharge pipe 40 is connected to a main tank 42. Also, the main tank 42
A circulation pipe 46 for circulating the coating liquid to the overflow tank 22 via a pump 44 is provided from the bottom surface of the circulating pipe 46.

(Coating Method) The process of coating the lower surface of the long base material W with the coating liquid using the coating apparatus 10 having the above configuration will be described with reference to FIGS. 2 (1) to 2 (4). Will be explained in order.

(1) First Step (See FIG. 2A) In the first step, that is, in the initial state, the nozzle 14 is disposed below the backup roll 12.

(2) Second Step (See FIG. 2 (2))
The nozzle 14 is raised by the vertical movement device 20, and the size of the discharge port 18 and the base material W is set to the coating thickness A.

In this case, the overflow tank 22 rises together with the nozzle 14, but not only the rise but also the overflow tank 22 using the motor 30.
The liquid height of the tank 32 is adjusted by the capillary gap 16 of the nozzle 14.
Is set to be at the upper end position in. Then, the stop valve 36 is opened to fill the capillary gap 16 with the coating liquid. In this case, as shown in FIG. 1, the liquid height of the capillary gap 16 is higher than the liquid height at the upper end of the tank 32 by B as described above. The reason for the increase by B is that in the capillary gap 16, the nozzle 14
This is because the coating liquid rises to the upper end of the coating liquid.

(3) Third Step (See FIG. 2 (3)) In the third step, the open stop valve 36 is closed,
The pumping device 38 is operated to pump the coating liquid inside the supply pipe 34 in the direction of the capillary gap 16. Then, the coating liquid inside the capillary gap 16 is blown out by the pressure and comes into contact with the lower surface of the substrate W. In the related art, it took a long time because the liquid contact was performed using only the capillary phenomenon. However, since the coating liquid is pressure-fed by the pumping device 38 to be in liquid contact, the liquid contact time is greatly reduced.

In this case, the substrate W is caused to run at the basic speed V by rotating the backup roll 12.

(4) Fourth Step (See FIG. 2 (4)) While the base material W is running at the basic speed V, the coating liquid is applied to the lower surface thereof by capillary action.

However, it is necessary to apply the coating liquid at a coating thickness A and to increase the running speed in order to increase the production efficiency. Therefore, the overflow tank 22 is set by the motor 30 to be slightly higher than the liquid height B when the liquid contact is completed. As a result, pressure is applied to the supply state of the coating liquid, and the coating liquid can be applied with a predetermined coating thickness even when the running speed is higher than the basic speed V.

(Effects of Embodiment) As described above, in the coating apparatus 10 of this embodiment, the nozzle 14 is not provided with a nozzle inside the liquid tank to utilize the capillary phenomenon as in the related art.
Since only the capillary gap 16 is provided inside and the coating liquid is applied by the capillary phenomenon, it is possible to perform the coating with the minimum necessary amount of the coating liquid. There is no need to throw away.

Further, since the nozzle 14 itself is not immersed inside the coating liquid, the coating liquid does not adhere around it.

Further, the overflow tank 22 after liquid contact
Since the traveling speed can be increased by increasing the height, the production efficiency can be increased.

[Second Embodiment] A coating apparatus 10 according to a second embodiment will be described with reference to FIG.

The difference between this embodiment and the first embodiment is that the shape of the substrate W to be coated is different. That is, the first
In the embodiment, the coating liquid is applied to the long base material W, but in this embodiment, the coating liquid is applied to a plate material such as a glass plate of a liquid crystal cell.

In this case, as shown in FIG. 3, a suction table having a suction port on the lower surface is disposed so as to be movable in the front-rear direction, a plate-shaped base material W is sucked on the lower surface, and a nozzle is provided on the lower surface. The coating liquid is applied from 14.

The coating method is the same as in the first embodiment.

[Modification] In the above two embodiments, the liquid contact was performed by pumping the coating liquid into the capillary gap 16 by the pumping device 38. Instead, the pumping device 38 and the stop valve 36 were removed. The liquid contact can be performed by the following method.

That is, when the capillary gap 16 is filled with a coating liquid up to a predetermined liquid level and is brought into contact with the liquid, the tank 32 of the overflow tank 22 is raised relatively to the nozzle 14. Then, since the coating liquid is pressure-fed to the capillary gap 16, the liquid can be contacted earlier than before.

[0054]

As described above, according to the present invention, the coating liquid is applied to the lower surface of the base material W using the capillary phenomenon only by the nozzle instead of the structure in which the nozzle is submerged in the coating liquid tank. Therefore, the coating liquid is not wasted and the nozzle is not stained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a coating apparatus showing a first embodiment of the present invention.

FIGS. 2 (1) to (4) are drawings showing a coating process of a coating device.

FIG. 3 is an explanatory view of a coating apparatus according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Coating apparatus 12 Backup roll 14 Nozzle 16 Capillary gap 18 Discharge port 22 Overflow tank 30 Motor 32 Tank 38 Pumping device

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shigeyoshi Kobayashi F-term (reference) 4D075 AC04 AC82 AC84 AC92 AC93 AC95 CA47 DA06 DB14 DC22 EA05 4F040 AA12 BA04 4F041 AA05 AB01 BA05 BA12 BA34 BA56 CA02 CA12 CA16 CA22 4F042 AA06 BA08 BA12 CA01 CA09 CB01 CB18 DF09

Claims (10)

[Claims] 1. A nozzle for a coating liquid for supplying a coating liquid to a capillary gap of a nozzle having a capillary gap having an upper end serving as a coating liquid discharge port. Provided, by determining the liquid height of the capillary gap based on the liquid height of the coating liquid in the tank, the coating liquid to the substrate traveling in the front-rear direction from the discharge port of the capillary gap A coating device characterized by performing coating. 2. The method according to claim 1, wherein the tank is provided so as to move up and down relatively to the nozzle, and the tank is moved up and down to move the liquid height in the capillary gap up and down. 2. The coating device according to 1. 3. The coating apparatus according to claim 2, wherein said tank is provided so as to be vertically moved by a motor relative to said nozzle. 4. The coating apparatus according to claim 2, wherein said tank is provided so as to be manually moved up and down relative to said nozzle. 5. The method according to claim 2, wherein the base material is a long base material, and a backup roll that conveys the base material in the front-rear direction is disposed above the nozzle. Coating equipment. 6. The suction device according to claim 1, wherein the base material is a plate-shaped base material, and a suction table for adsorbing the plate-shaped base material on a lower surface and transporting the base material in the front-rear direction is arranged above the nozzle. The coating device according to claim 2, wherein the coating device is used. 7. A pumping means for feeding a coating liquid to the capillary gap in a path for supplying the coating liquid from the tank to the capillary gap of the nozzle. 7. The coating device according to items 6 to 6. 8. A nozzle extending in the left-right direction having a capillary gap having an upper end serving as a coating liquid discharge port, and a coating liquid tank for supplying the coating liquid to the capillary gap of the nozzle. A coating method of a coating apparatus provided with a pumping means for pressure-feeding a coating liquid to the capillary gap in a path of supplying the coating liquid from the tank to the capillary gap of the nozzle. In the next step, a coating liquid is applied to the substrate traveling in the front-rear direction. Disposing the nozzle so that the distance between the discharge port of the nozzle and the lower surface of the base material becomes the coating thickness of the coating liquid.
Process. A second step in which the coating solution is pressure-fed to the capillary gap by the pressure feeding means, and the coating solution is brought into contact with the lower surface of the substrate from the discharge port. A third step of applying a coating liquid from the discharge port while being in contact with the lower surface of the base material. 9. A nozzle extending in the left-right direction having a capillary gap having an upper end serving as a coating liquid discharge port, and a coating liquid tank for supplying the coating liquid to the capillary gap of the nozzle is provided. This is a coating method of the provided coating apparatus, in which a coating liquid is coated on a substrate traveling in the front-rear direction in the following steps. A first step of arranging the nozzle such that a distance between a discharge port of the nozzle and a lower surface of the substrate is equal to a coating thickness of a coating liquid;
A second step in which the coating liquid is pressure-fed to the capillary gap by increasing the liquid height of the tank, and the coating liquid is brought into contact with the lower surface of the base material from the discharge port. A third step of applying a coating liquid from the discharge port while being in contact with the lower surface of the base material. 10. The method according to claim 10, wherein the traveling speed of the base material is initially set at a basic speed, and the height of the liquid in the tank is gradually increased. The method according to claim 8 or 9, further comprising a step of applying a coating liquid to the lower surface of the base material gradually from a speed.