JPH09141170A - Coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement coating operation which can avoid formation of bubbles even if conveying speed of a substrate (W) is raised. SOLUTION: This apparatus is provided with a backing roll 2 and an applying die 3 having a coating liquid discharging slit 3a extending along a traverse direction with respect to a substrate-conveying path (R), and a gas chamber 12 having an interior space 12a facing the substrate conveying path (R) and the coating liquid discharging slit 3a is provided in a substrate carrying-in side of the coating liquid discharging slit 3a, and a suction chamber 13 having an interior space 13a facing the substrate conveying path (R) is provided in a substrate carrying-in side of the gas chamber 12, and a partition plate 14 transversely extending in an interface between the gas chamber 12 and the suction chamber 13 is provided. A gas inlet hole 16a of a gas feeding device 16 is opened in the interior 12a of the gas chamber 12, and a suction hole 17b of a suction device 17 is opened in the interior of the suction chamber 13, and pressure in the interior 12a of the gas chamber 12 can be made negative with respect to atmospheric pressure by adjusting pressures of the gas feeding device 16 and the suction device 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating device for discharging a coating liquid from a coating liquid discharge slit and coating the substrate while being guided by a backing roll.

[0002]

2. Description of the Related Art A conventional coating apparatus 1 is shown in FIGS.
As shown in FIG. 3, a backing roll 2 having a base material transfer path R formed on the outer peripheral surface 2a and rotatable in the direction of arrow E, and a coating liquid discharge slit 3a facing the base material transfer path R are connected to the base material transfer path R. And a coating die 3 extending along the transverse direction of the. The coating apparatus 1 discharges the coating liquid C from a coating liquid discharge slit 3a toward a sheet-shaped substrate W such as paper, plastic film, or metal foil guided by a backing roll 2 to form a substrate surface Wa. Coating film M with desired film thickness T
To form

[0003]

By the way, the base material W is
When the transportation speed becomes high, an entrained flow having the same speed as the transportation speed accompanies the surface Wa. However, this high-speed entrained flow is, as shown in FIG.
In order to strongly press the coating liquid ejecting portion Ca that is ejected from the substrate and comes into contact with the base material W in the conveying direction indicated by the arrow E, a wedge-shaped space N is formed and a space between the coating film M and the base material surface Wa. May invade. The entrained flow that has penetrated remains as fine bubbles B, causing defects in the coating film M. Therefore, conventionally, there has been a problem that the higher the transport speed of the base material W, the more the bubbles B are generated and the coating defects are more likely to occur.

In order to solve the above problems, it is an object of the present invention to provide a coating device capable of performing coating capable of preventing the generation of bubbles even when the substrate is transported at a high speed.

[0005]

The gist of the present invention as set forth in claim 1 is to provide a rotatable backing roll having a base material conveying path formed on the outer peripheral surface thereof, and a coating solution discharge slit facing the base material conveying path. In a coating apparatus having a coating die extending along the transverse direction of the base material transport path, a gas chamber that forms a chamber facing the base material transport path and the coating solution discharge slit is formed from the coating solution discharge slit. A suction chamber that is provided on the substrate loading side and that forms a chamber facing the substrate transport path is provided on the substrate loading side from the gas chamber, and extends along the transverse direction at the boundary between the gas chamber and the suction chamber. Is provided, the air supply port of the gas supply device is opened in the chamber of the gas chamber, the suction port of the suction device is opened in the suction chamber, and the pressure of the gas supply device and the suction device is adjusted to the outside of the gas chamber. It is a coating device characterized in that it can be made to have a negative pressure compared to. The gist of the present invention according to claim 2 is that in the suction tool, the suction port is also opened in the gas chamber, and the negative pressure inside the suction chamber can be set lower than the negative pressure inside the gas chamber. The coating apparatus according to claim 1 configured as described above.

A third aspect of the present invention is to provide a rotatable backing roll having a base material conveying path formed on an outer peripheral surface thereof, and a coating solution discharge slit facing the base material conveying path for the base material conveying path. In a coating apparatus provided with a coating die extending along a transverse direction, a nozzle box is provided on the base material carry-in side of the coating liquid discharge slit, and the nozzle box faces the base material conveying path and crosses the base material. A guide surface extending in a direction, and a gas discharge slit that discharges gas in a direction opposite to the base material conveying direction toward a gap between the base material conveying path and the guide surface, the nozzle box and the coating die. And a gas chamber that forms a chamber facing the substrate transport path and the coating liquid discharge slit, is provided between the coating device and the substrate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a coating apparatus according to the present invention (hereinafter, referred to as "the present invention apparatus") will be described based on an embodiment shown in the drawings. (First Embodiment) FIGS. 1 and 2 show a first embodiment of the device of the present invention.
FIG. 1 (A) is a side view showing a cross section of a main part, and FIG. 1 (B) is an enlarged side view showing the vicinity of a coating liquid discharge slit during coating. (C) is a side view showing an enlarged tip of a weir of another aspect, and FIG. 2 is FIG. 1 (A).
FIG. 3 is a plan view of the right side cross section of FIG.

Like the conventional apparatus, the coating apparatus 11 according to the present embodiment has a backing roll 2 having a base material conveying path R formed on the outer peripheral surface 2a and rotatable in the arrow E direction, and the base material conveying. The coating liquid discharge slit 3a facing the path R is provided along the transverse direction of the base material transfer path R (direction of arrow D shown in FIG. 2). The improvement of the coating apparatus 11 is that a gas chamber 12 is provided on the carry-in side of the coating die 3 and a suction chamber 13 is provided on the carry-in side of the gas chamber 12 side by side.
The barrier plate 14 extending in the transverse direction (arrow D direction) is provided at the boundary between the 2 and 13.

The gas chamber 12 forms a chamber 12a facing the substrate transfer path R and the coating liquid discharge slit 3a so that the chamber 12a and the outdoor chamber H are separated from each other by the partition wall 15 and the coating die 3.
It is separated by and. The gas chamber 12 is configured such that the air supply port 16a of the gas supply tool 16 is opened in the chamber 12a and the chamber 12a can be filled with a replacement gas such as carbon dioxide gas or a solvent gas. Further, in the gas chamber 12, the suction port 17a of the suction tool 17 is opened in the room 12a so that the room 12a can be made to have a negative pressure with respect to the outside H.

The suction chamber 13 is partitioned by a partition wall 18 so as to form a chamber 13a facing the base material transfer path R from the chamber 13a. The suction chamber 13 is a chamber 13a
The suction port 17b of the suction tool 17 is opened to allow the room 13a to have a negative pressure with respect to the room H. Suction chamber 1
3, a partition plate 19 extending in the transverse direction (arrow D direction) is provided on the carry-in side so that the partition plate 19 can be adjusted back and forth toward the backing roll 2, and the tip 19a of the partition plate 19 and the base material W The gap between the two can be adjusted.

The barrier plate 14 is provided so as to be adjustable forward and backward toward the backing roll 2, and the size of the gap J between the tip 14a and the substrate W can be adjusted.
In addition to forming the tip 14a of the dam plate 14 into a flat surface,
As shown in FIG. 7C, one or more grooves 14b extending in the transverse direction (arrow D direction) may be provided so as to increase the ventilation resistance.

The suction tool 17 has a suction side of the suction fan 20 formed in a branched manner, and control valves 21, 21 are provided in the respective branch passages 17c, 17d so that the suction chamber 13 has a pressure lower than the negative pressure in the chamber 12a of the gas chamber 12. The negative pressure in the room 13a can be set lower.

In the coating apparatus 11 constructed as described above, during the coating operation, the chamber 12a of the gas chamber 12 is filled with the replacement gas supplied from the gas supply tool 16, and the gas chamber 12 is also filled.
The inside of the room 12a is made negative by the suction of the suction tool 17. Further, the coating device 11 sets the negative pressure in the chamber 13a of the suction chamber 13 to be lower than the negative pressure in the chamber 12a of the gas chamber 12 by adjusting the control valves 21 and 21 of the suction tool 17.

As shown in FIG. 1B, in the coating liquid discharging portion Ca which is discharged from the coating liquid discharging slit 3a and is about to come into contact with the base material W, the chamber 12a of the gas chamber 12 has a negative pressure to the outside. Therefore, the outdoor H side is pressed by the atmosphere in the arrow F direction, and the indoor 12a side is sucked in the arrow G direction which is the indoor direction. Therefore, the coating liquid ejecting portion Ca advances in a direction substantially orthogonal to the base material W and is applied while forming a bead Cb at a contact portion with the base material W. Therefore, the replacement gas inside the chamber 12a is less likely to enter between the base material surface Wa and the coating liquid discharge portion Ca due to the formation of the beads Cb.

When a gas that is easily dissolved in the coating liquid C (for example, carbon dioxide gas or a gas of a solvent contained in the coating liquid C) is used as the substitution gas, for example, the substrate surface Wa
Even if a small amount of gas enters between the coating liquid ejecting portion Ca and the coating liquid discharging portion Ca, the minute amount of gas dissolves in the coating film M and disappears. Therefore, the coating film M in which bubbles do not remain can be obtained.

Furthermore, the tip 14a of the barrier plate 14 and the surface W of the base material
Since the negative pressure in the chamber 13a of the suction chamber 13 is set to be lower than the negative pressure in the chamber 12a of the gas chamber 12 by the suction tool 17, the gap J with respect to a is in the base material conveying direction (arrow E direction). The replacement gas can flow in the opposite direction. The replacement gas flowing through the gap J removes the accompanying flow adhering to the substrate surface Wa at the gap J. As a result, the coating liquid ejection portion Ca
In FIG. 1B, the arriving entrainment flow becomes zero or very small, and the entrainment flow does not press the outdoor H side, and the wedge-shaped space N (FIG. 1B) is formed between the entrainment flow and the substrate surface Wa. 5 (B)) is not formed.

As described above, the coating device 11 includes the gas chamber 12
Action of the replacement gas filled in the room 12a of the room and the dam plate 1
Due to the synergistic effect of the removal action of the entrained flow by 4, the bubbles can be made more difficult to enter between the base material surface Wa and the coating liquid discharge portion Ca. As a result, the coating device 11
Enables the coating film M to be coated without bubble defects even if the transport speed of the substrate W is increased.

The coating device 11 adjusts the gap J between the tip 14a of the barrier plate 14 and the surface Wa of the substrate even if the chamber 12a of the gas chamber 12 is not sucked by the suction port 17a of the suction tool 17. When the pressure inside the room 12a can be made negative with respect to the outside H, the suction port 17a can be omitted.

(Second Embodiment) FIG. 3 shows a second embodiment of the device of the present invention, and is a side view showing a main portion in section.

Like the conventional apparatus, the coating apparatus 31 according to the present embodiment has a backing roll 2 having a base material transfer path R formed on the outer peripheral surface 2a and rotatable in the arrow E direction, and a base material transfer. The coating liquid discharge slit 3a facing the path R is provided along the transverse direction of the base material transfer path R (direction of arrow D shown in FIG. 2). The improvement of the coating device 31 is that a nozzle box 33 is provided on the substrate loading side of the coating liquid discharge slit 3a, a gas chamber 32 is provided between the nozzle box 33 and the coating die 3, and suction is performed on the loading side of the nozzle box 33. The chamber 34 is provided.

The nozzle box 33 faces the base material transfer path R and extends in the transverse direction of the base material transfer path R (direction of arrow D in FIG. 2), and the base material transfer path R and the guide surface 33a. A gas discharge slit 33b for ejecting gas in the direction opposite to the substrate transport direction (arrow E direction) is provided toward the gap K between the surface 33a, and the gas discharged from the gas discharge slit 33b is the gap K.
It is made to flow. The nozzle box 33 is the inside 33 of the box.
c has a rectifying plate 33d built in, and gas supplied from the fan 36 of the gas supply device 35 is supplied to the gas discharge slit 3
Discharge is made uniformly over the entire width direction of 3b.

The gas chamber 32 forms a chamber 32a facing the substrate transport path R, the coating liquid discharge slit 3a and the gap K so that the chamber 32a and the outdoor chamber H are separated from each other by a partition wall 36,
It is partitioned by the coating die 3 and the nozzle box 33. Gas chamber 3
2 is configured such that the air supply port 16a of the gas supply tool 16 is opened in the room 32a and the room 32a can be filled with a replacement gas such as carbon dioxide gas or solvent gas.

The suction chamber 34 is used to collect the gas, which has come out from the gap K between the guide surface 33a of the nozzle box 33 and the base material conveying path R, by the collecting device 37, and is used in the working environment. It is provided as necessary to maintain hygiene.

When the gas discharged from the gas discharge slit 33b of the nozzle box 33 flows into the gap K during the coating operation, the coating device 31 sucks the gas flowing into the gap K so that the chamber 32a of the gas chamber 32 becomes negative. Along with increasing the pressure, the accompanying flow adhering to the substrate surface Wa is removed by the gas flowing through the gap K. The gas chamber 32 that is filled with the replacement gas and is in a negative pressure state exhibits the same function and effect as the gas chamber 12a of the first embodiment, and the substrate surface Wa and the coating liquid discharge portion Ca.
(See FIG. 1B) makes it difficult for the replacement gas to enter. Then, the coating device 31 includes the chamber 32 of the gas chamber 32.
By the synergistic action of the suction action of the replacement gas filled in a and the action of removing the entrained flow by the nozzle box 33, it is possible to make bubbles more difficult to enter between the substrate surface Wa and the coating liquid discharge portion Ca. As a result, the coating device 31 enables the coating film M to be coated without bubble defects even if the transport speed of the substrate W is increased.

(Third Embodiment) FIG. 4 shows a third embodiment of the device of the present invention and is a side view showing a main portion in section.

The coating device 41 according to the present embodiment has substantially the same constituent members as those of the first embodiment shown in FIGS. 1A and 1B, and is arranged above the backing roll 2. The difference is that the coating die 3 is arranged so that the coating liquid film discharged from the coating liquid discharging slit 3a can flow down to the surface Wa of the substrate being conveyed.

The coating device 41 includes a backing roll 2 having a base material transfer path R formed on the outer peripheral surface 2a and rotatable in the direction of arrow E, and a coating liquid discharge slit 3a facing the base material transfer path R. The coating die 3 is provided extending along the transverse direction of the transport path R (the arrow D direction shown in FIG. 2), and the gas chamber 12 is provided on the carry-in side of the coating die 3 and on the carry-in side of the gas chamber 12. Suction chambers 13 are arranged side by side, and a barrier plate 14 extending in the transverse direction is provided at the boundary between both chambers 12, 13. The operation and effect of the coating device 41 is substantially the same as that of the first embodiment shown in FIGS. 1A and 1B, and therefore the description thereof is omitted here.

[0028]

As described in detail above, the device of the present invention exhibits the following excellent effects. In order to prevent the invasion of air bubbles into the coating film, the device of the present invention according to claims 1 and 2 has a synergistic effect of the suction action of the replacement gas filled in the chamber of the gas chamber and the action of removing the entrained flow by the dam plate. Even if the substrate is transported at a high speed, the coating can be applied without causing bubble defects. In the device of the present invention as set forth in claim 2, since the inside of the gas chamber is forcibly made to have a negative pressure by the suction tool, the suction action of the replacement gas filled in the chamber of the gas chamber can be further enhanced.

According to the third aspect of the present invention, the synergistic action of the suction action of the replacement gas filled in the gas chamber and the action of removing the entrained flow by the nozzle box prevents the invasion of bubbles to the coating film. In addition, even if the transport speed of the substrate is increased, it is possible to apply the coating film without bubble defects.

[Brief description of the drawings]

1A and 1B show a first embodiment of an apparatus of the present invention, FIG. 1A is a side view showing a cross section of a main part, and FIG. 1B is an enlarged view of the vicinity of a coating liquid discharge slit during coating. Side view,
FIG. 6C is a side view showing an enlarged tip of a weir of another aspect.

FIG. 2 is a plan view of the right side cross-section taken along the line EE of FIG.

FIG. 3 shows a second embodiment of the device of the present invention, and is a side view showing a main portion in section.

FIG. 4 shows a third embodiment of the device of the present invention, and is a side view showing a main portion in section.

5A and 5B are views showing a conventional coating device, in which FIG. 5A is a side view showing a cross section of a main portion, and FIG. 5B is a side view showing an enlarged vicinity of a coating liquid discharge slit during coating.

[Explanation of symbols]

 2 ... Backing roll 3 ... Coating die 3a ... Coating liquid discharge slit 12 (32) ... Gas chamber 13 ... Suction chamber 14 ... Dam plate 16 ... Gas supply tool 17 ... Suction tool 33 ... Nozzle box R ... Substrate transport path W …Base material

Claims (3)

[Claims] 1. A coating comprising a rotatable backing roll having a base material transfer path formed on the outer peripheral surface thereof, and a coating liquid discharge slit facing the base material transfer path extending along the transverse direction of the base material transfer path. In a coating apparatus including a die, a gas chamber that forms a chamber facing the base material transport path and the coating liquid discharge slit is provided on the base material carry-in side of the coating liquid discharge slit, and faces the base material transport path. A suction chamber that forms a chamber is provided on the substrate loading side of the gas chamber, a barrier plate extending in the transverse direction is provided at the boundary between the gas chamber and the suction chamber, and the gas supply device is provided with air in the chamber of the gas chamber. A mouth is opened, and a suction port of a suction tool is opened in the suction chamber so that the inside of the gas chamber can be made to have a negative pressure as compared with the outside by adjusting the pressure of the gas supply tool and the suction tool. Coating device. 2. The suction device according to claim 1, wherein the suction port is also opened in the gas chamber so that the negative pressure inside the suction chamber can be set lower than the negative pressure inside the gas chamber. The coating device described. 3. A coating roll in which a rotatable backing roll having a base material conveying path formed on the outer peripheral surface thereof and a coating solution discharge slit facing the base material conveying path are provided along a transverse direction of the base material conveying path. In a coating device equipped with a die, a nozzle box is provided on the substrate loading side from the coating liquid discharge slit, and the nozzle box is
A guide surface that extends in the transverse direction facing the base material transfer path, and a gas discharge slit that ejects gas in a direction opposite to the base material transfer direction toward a gap between the base material transfer path and the guide surface. And a gas chamber that forms a chamber facing the substrate transfer path and the coating liquid discharge slit is provided between the nozzle box and the coating die.