JPH11169767A - Curtain coating apparatus and coating method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high speed coating by eliminating the liquid splashing phenomenon of a coating soln. at the start and completion times of the coating by a curtain coating apparatus or the creeping phenomenon to the lower part of a back roll and perfectly eliminating process contamination or the deterioration of product quality accompanied thereby to suppress the wasteful consumption of the coating soln. or the lowering of a yield. SOLUTION: In a curtain coating apparatus forming the curtain film of a coating soln. on the support web 22 fed through a back roll 21 by a coater die 1 and the edge guide 6 attached thereto to apply the coating soln., a coating soln. recovery box 11 is integrally formed along with the coater die 1 and the edge guide 6 in adjacent relation to the back roll 21 and the integrally constituted one performs the advance to a coating position and the retreat from the coating position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curtain coating apparatus and a curtain coating method for applying a coating solution to a supporting web being transported.

[0002]

2. Description of the Related Art Many patent applications have been published or published with respect to the technology of curtain coating apparatuses and methods.

[0003] First, in order to prevent problems such as contamination around the coater and foaming of the coating solution due to the splash of the coating solution, Japanese Patent Publication No. Hei 6-24664 is applied as shown in a side sectional view of FIG. However, according to this method, much equipment needs to be added to the conventional coater.

[0004] As for the method of starting and ending the coating, generally, a movable plate-like member called a "curtain liquid receiving plate" is put in and out of the lower side of the curtain film to start and end the coating. Many have been filed. For example, JP-B-49-35447, JP-B-49-35447
24133, JP-A-7-185432, JP-A-7-185
No. 178364, JP-A-63-51973, JP-A-1
JP-A-304076, JP-A-2-277570, JP-A-4-61951, JP-A-3-94863, and the like.

In all of these techniques, at the start and end of coating, the position of the coater die and the support web is fixed from beginning to end, and during preparation for coating start, the curtain liquid receiving plate is inserted between the support and the edge guide to perform coating. After the formation of the liquid curtain film is confirmed to be stable, the curtain liquid receiving plate is retracted so that the curtain film collides with the support web to start coating. In this case, the coating is completed by inserting the curtain liquid receiving plate again between the support and the edge guide.

Further, this technique requires a curtain liquid receiving plate as an additional equipment and peripheral equipment for holding and moving the same.

[0007] As another problem, the curtain liquid receiver is easily contaminated by the coating liquid, thereby increasing the possibility of soiling the product.

Further, in order to prevent the occurrence of coating unevenness due to air entrained by the web, Japanese Patent Application Laid-Open Nos.
Patents such as US Pat. No. 3,931,331 are disclosed. Also in this case, it was necessary to add a facility called a decompression function.

In addition, they have only the effect of scraping entrained air and have no other function.

As described above, curtain coating is a coating method requiring many additional facilities.

Further, when switching to another coating method, for example, a slide bead coating method, after using the curtain coating method, it is necessary to remove the curtain liquid receiving equipment and the accompanying air scraping device, etc. Was hanging.

[0012]

Curtain coating is a coating method in which a coating solution is dropped from a high place onto a support web in a film form, and has problems such as contamination around a coater and bubbling. Specifically, as seen in the prior art apparatus shown in FIG. 7, in the curtain film preparation work before the start of coating, contamination around the coater due to splashing of the liquid, stable formation of the curtain film contained in the coating liquid. The problem is the buildup of foam on the catch pan (liquid tray or collection box) 44 that receives the curtain film due to the surfactant for the purpose.

The means for dropping from this high place and starting and ending the curtain coating is generally performed by putting a so-called "curtain liquid receiving plate" (45) into and out of the lower side of the curtain film. Many applications have been filed. However, the method of starting and ending the application by moving the curtain liquid receiving plate 45 is difficult due to the relationship with the edge guide 42. That is, before the start of application,
The curtain liquid receiving plate 45 is preferably inserted into a gap between the edge guide 42 and the support web 22 in order to prevent the back roll 21 and the support web 22 from being contaminated. Receiving plate 45
Was easy to interfere.

For this reason, the edge guide 42 changes from a regular position to a different position, which hinders the subsequent formation of the curtain film, and makes stable coating impossible.

Further, since the curtain liquid receiving plate 45 moves considerably close to the support web 22, the curtain film collides against the curtain liquid receiving plate 45, causing the curtain liquid receiving plate 45 itself and the surroundings to be stained, and This leads to contamination of the body web 22 and the process.

Therefore, a method of moving the coater die 41 without using the curtain liquid receiving plate 45 was attempted at the time of research and development of the present invention. However, when the coating liquid flow rate is high and the coating speed is high, the coating liquid is moved along the back roll. It was found that the application liquid circulated below the roll, and the equipment below the back roll 21 and the roll upstream of the back roll 21 were soiled, leading to process contamination.

Furthermore, in curtain coating, the curtain film is very thin and falls freely, and is therefore vulnerable to disturbance. For example, entrained air from the support web often acts as a strong disturbance to the curtain film,
This wind sometimes caused application unevenness. To prevent this, Japanese Patent Application Laid-Open Nos.
Patents such as 39331 are disclosed. However, they only had the effect of scraping entrained air and did not have other functions.

Further, there is an increasing need to quickly change curtain coating and other coating methods for the following reasons.

First, curtain coating is generally known as a simultaneous multilayer coating method capable of high-speed coating. For example, among patents filed so far, a coating speed of 500 m / m
It is described to about in, and is one of the most excellent coating methods at present for the purpose of simultaneous multilayer coating. For this reason, curtain coating is a preferred coating method for extremely high productivity and cost reduction.

However, curtain coating is a coating method unsuitable for low-speed coating. That is, curtain coating is a coating method on the premise that a curtain film is formed, and if the flow rate per unit width is less than 1.0 cc / cm · sec, the curtain film is not formed. Is impossible.

Further, even if a sufficient surfactant cannot be added to the coating solution due to some restrictions, a curtain film may not be formed in some cases. In this case, too, curtain coating becomes impossible.

When it is necessary to perform the coating under the condition that these curtain films cannot be formed, another coating method such as a bead forming portion 53 as shown in a side sectional view of FIG. It is necessary to perform the application using a slide bead applying apparatus constituted by 56 and a coater die 51.

Particularly, recently, due to diversification of consumer needs, production of a wider variety of products has become necessary.
In order to respond to this, it is necessary to produce not only curtain coating but also other coating methods, for example, slide bead coating, and it is important to use a plurality of coating methods in terms of market needs. .

Therefore, the first possibility is to divide the factories into separate factories, which are divided into a factory dedicated to curtain coating and a factory dedicated to slide bead coating.
However, as for the number of coating factories, production in as few factories as possible is preferable in order to reduce construction costs, energy costs, and labor costs.

For this reason, in one factory, a technique for changing from curtain coating to another coating method has been required.
However, this change in coating method is a change in equipment and is generally very time consuming. Here, the equipment change means not only the change of the coater die, but also the removal and installation of the curtain liquid receiving plate equipment, the accompanying air scraping equipment, etc., and the man-hour for this is very large.
Therefore, changing the coating method is not preferable in terms of improving the operation rate of the factory.

As described above, the necessity for promptly changing the coating method has been increased in order to improve the characteristics of the coating method, meet the needs of consumers, and improve the operation rate of the factory.

The present invention provides a curtain coating apparatus and a curtain coating method using the same, which can solve the above-mentioned problems and can always attain a stable high-quality high-speed curtain coating without contaminating the process. The purpose is to make it easy to switch between methods.

[0028]

This object is achieved by any one of the following technical means (1) to (12).

(1) Curtain coating in which a coating film is formed on a support web conveyed via a back roll by a coater die and an edge guide attached thereto and the coating solution is applied at a coating position. In the apparatus, a coating liquid recovery box having an opening on the upper side adjacent to the back roll is provided integrally with the coater die and the edge guide, and the integrally-configured block advances to the coating position and retreats from the coating position. And a curtain coating device.

(2) Curtain coating in which a curtain film of a coating solution is formed on a support web conveyed via a back roll by a coater die and an edge guide attached thereto, and the coating solution is coated at a coating position. In the apparatus, a coating liquid recovery box having an opening at an upper side adjacent to the back roll is provided integrally with the coater die and the edge guide and fixed, and the back roll moves to advance to the coating position and perform the coating. A curtain coating apparatus characterized in that it is retracted from a position.

(3) The coating liquid recovery box is a box-shaped member provided on both sides with a shape along the peripheral surface of the back roll, (1) or (2).
Item 4. A curtain coating device according to Item 1.

(4) The coating liquid recovery box is provided between the curtain film and the web at a position 1 to 10 cm upstream of the collision direction of the support web in the transport direction of the support web, in close proximity to the support web and between the web and the web. The curtain coating apparatus according to any one of (1) to (3), further comprising an entrained air scraping plate having a gap of 0.1 to 5.0 mm.

(5) The curtain coating apparatus according to item (4), wherein the entrained air scraping plate is movable so as to eliminate the gap.

(6) The coating liquid collecting box described in (4) or (5), wherein the coating liquid recovery box is configured to reduce the pressure upstream of the entrained air scraping plate to -10 mmAq or less. apparatus.

(7) The curtain coating apparatus according to any one of (1) to (6), wherein the coating liquid recovery box has a water sealing function.

(8) The curtain coating apparatus according to any one of (1) to (7), wherein the coating liquid recovery box is provided with a net plate or an oblique plate at a bottom portion.

(9) The application liquid recovery box has a function of cleaning the inside of the box (1).
The curtain coating device according to any one of items (8) to (8).

(10) A coating method characterized by applying a coating solution to a support web using the curtain coating apparatus according to any one of (1) to (9).

(11) A curtain coating apparatus for integrally coating a coater die, an edge guide for forming a curtain film, and a coating liquid recovery box for coating a support web conveyed via a back roll. A coating method in which a curtain film is formed at a location away from the support web, and the integrated coater die is advanced to the coating position, without using a curtain liquid receiving plate, to start coating. The flow rate of the coating solution is 2.0 to 8.0 cc /
cm · sec, coating speed 150-500
m / min, the coater advance speed is 3-50 cm /
sec, the retreat speed of the coater at the end of coating is 3 to 50 cm
/ Sec, a curtain coating method.

(12) A curtain coating apparatus for integrally coating a coater die, an edge guide for forming a curtain film, and a coating liquid recovery box for coating a support web conveyed via a back roll. A coating method for starting coating without using a curtain receiving plate by forming a curtain film away from the support web and advancing the back roll to a coating position. Is 2.0 to 8.0 cc / cm · sec,
When the coating speed is 150 to 500 m / min, the forward speed of the back roll is 3 to 50 cm / sec.
c, the retreat speed of the back roll at the end of coating is 3 to 50
A curtain coating method, wherein the coating is performed at a rate of cm / sec.

[0041]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.
In the following description, although there are definite expressions for terms and the like, they show preferred examples of the present invention, and do not limit the meaning of the terms of the present invention and the technical scope.

The present invention will be described with reference to the sectional side views of FIGS. 1 (a), 1 (b) and 1 (c). 1A shows a state before the start of coating or after the end of coating, FIG. 1B shows a state at the moment of starting or finishing coating, and FIG. 1C shows a state at the coating position.

The coater die 1 is formed by a slit 2 to which the coating liquid of each layer is supplied, a slide surface 3 on which a multilayer coating liquid on which the coating liquid flowing out of the slit 2 flows is overlapped, and a coater lip 4 formed at the lower end thereof. An edge guide 6 is integrally attached to the coater die 1 from both sides in the width direction of the coater lip 4. A coating liquid recovery box 11 having an opening on the upper side is also integrally attached to the coater die 1 below.
From the state shown in FIG. 1A to the moment shown in FIG. 1B due to the integration of the coating liquid recovery box 11 with the coater die 1, all the curtain liquid films 7 are received in the recovery box 11, Peripheral equipment is not stained due to liquid splashing. In addition, by integrating the coater die 1, the edge guide 6, and the coating liquid collecting box 11, the transfer of the curtain coating device can be quickly performed. Here, the coating liquid recovery box 11 has an opening on the upper side so that the curtain liquid film can be recovered, and what kind of coating liquid is fixed to the coater dice 1 or a peripheral member of the coater dice 1 The shape may be acceptable. Also, any material can be used as long as it can maintain the gap at each location. The edge guide 6 is fixed by the coater die 1 or a coater die peripheral member.

Further, an entrained air scraping plate 13 is attached to the collection box 11 through a pedestal 12, a reduced pressure suction port 15 and a washing water injection port 19 are provided on the side, and a diagonal plate 14 and A pipe 16 is provided, which also serves as an outlet for water sealing and draining. The washing water inlet 19 for washing may be provided at any place where the collection box 11 can be washed. The temperature of the washing water is not so limited, but a warmer one has a more effective washing. However, if the temperature is too high, each gap may change due to temperature distortion. Therefore, 20 ° C to 60 ° C is appropriate. The block A integrated as described above can be moved forward and backward. On the other hand, the back roll 21 and the support web 22 wound therearound, the water sealing container 17 and the connection port 18 of the pressure reducing device are provided at a fixed position in the state of the integrated block B. I have.

In performing the coating, first, FIG.
As described above, in a state where the block A of the coater dice 1 is moved and retracted from the block B fixed at the fixed position, the application liquid is flown to observe and confirm the formation state of the curtain film. A normal curtain film is formed by the edge guides 6 on both sides, and the curtain film is separated from the edge guide 6 to become a curtain film 7 with a contraction. According to the pipe 16
Is discharged from The oblique plate 14 is effective in preventing foaming of the coating waste liquid. The angle of the slanted plate 14 is preferably 45 degrees or more with respect to the horizontal for suppressing bubbles, but may be any number of times as long as the bubbles prevent liquid shearing. Also, as shown in FIG. 3, the same foaming suppression effect can be obtained by using a net plate 14A instead of the diagonal plate 14. During the curtain film forming operation, it is preferable that the lower end of the water seal pipe is protruded above the liquid level of the water seal container in order to promote bubble removal. Further, in the state shown in FIG. 1A, it is possible to wash the inside of the collection box 11 at any time by injecting washing water from the washing water inlet 19.

In any case, according to the result of observation of the curtain film described above, if it is good, the state shown in FIG.
The moving block A is advanced to the state shown in FIG.

In the state shown in FIG. 1C, the edge guide 6 is provided on the support web 2 wound around the back roll 21.
2. The collection box 11 is located at a position where a liquid contact point is formed, and the recovery box 11 has a concentric position along the peripheral surface of the back roll 21 with the circular arc shape of both end surfaces in the width direction of the upper open portion. 13 is a partial side sectional view of FIG.
A gap 13A of 0.1 to 5.0 mm is formed between the backing roll 21 and the support web 22 wound therearound. The position of the gap 13A is 1 cm to 10 cm upstream of the support web 22 in the transport direction from the liquid contact point at the lower end of the edge guide 6.

The gap 13A of the entrained air scraping plate 13 is preferably wide, for example, 1 mm or more, for stable passage of the splicing tape. As shown in the side sectional view of FIG.
It is preferable that the dimension of the gap 13 </ b> A can be adjusted with the mounting part 12. The thickness 13B of the entrained air scraping plate 13 may be 0.1 to several tens mm.

Further, a labyrinth shape may be provided in the gap portion of the entrained air scraping plate 13 to enhance the entrained air scraping effect.

Further, in order to prevent the entrained air scraping plate 13 from being stained, a moving mechanism can be provided as shown in a partial side sectional view of FIG. As the moving means, a means using a piston movement, a rotation method, or the like can be considered. FIG. 5 shows a method of retracting the entrained air scraping plate 13 by rotating it about 90 degrees around the rotation axis 13C.

As shown in the partial side sectional view of FIG.
Between the coater die 1 and the entrained air scraper 13,
There may be an opening 13D.

The gap between the back roll 21 and the portion along the back roll 21 on both sides of the coating liquid recovery box 11 may be any number as long as the pressure can be reduced, but for example, 0.1 to 5 mm is appropriate. .

On the other hand, the decompression suction port 15 attached to the application liquid recovery box 11 is connected to the connection port 18 of the decompression device, and can be suctioned. That is, the pressure upstream of the gap 13A of the entrained air scraping plate 13 is reduced to | -10 | mmAq or less. Due to this pressure reduction, air flows in the gap 13A in the direction opposite to the direction in which the support web 22 is transported. For this reason, the entrained air by the support web becomes more and more difficult to pass through the gap 13A, and the curtain film 7 does not fluctuate due to the entrained air. At this time, the distal end of the pipe 16 at the bottom is immersed in a container 17 filled with water to form a water-sealed state so that the pressure can be reduced smoothly.

In this way, the trial observation of the curtain film at the position of FIG. 1A and the formal coating at the position of FIG. 1C are performed very efficiently and stably.
While the block A is moving (forward, backward) in a specific area from the position (b) to the position in FIG.
As shown in (b), there was a phenomenon that the coating liquid 7A flows in the upstream direction of the support web 22 and stains the surface of the support web 22, the transport roll surface of the web 22, and the periphery of the back roll 21. This phenomenon is a phenomenon that cannot occur when a curtain liquid receiving plate is used, which is often seen in the prior art.
Further, in the present invention, it was found that this phenomenon does not occur when the coating speed is 150 m / min or less, but occurs when the coating speed is higher than the limit speed. Since this cannot cope with high-quality and high-efficiency productivity by high-speed coating in the future, the present applicant has repeatedly studied and established the following coating method to solve the problem. That is, as shown in Example 1, the flow rate of the coating liquid is 2.0 to 8.0 cc / cm · sec.
c, Coating speed is 150-500m / min
, The forward speed of the block A including the coater dice 1 (hereinafter sometimes simply referred to as the coater forward speed) is 3 to
50 cm / sec, the retreat speed of block A at the end of coating (hereinafter sometimes simply referred to as coater retreat speed) is 3 to
The problem was solved by coating at 50 cm / sec.

In all of the above-described embodiments, the system in which the block A is moved with respect to the fixed block B is adopted. On the contrary, the side sectional views of FIGS. 2 (a), 2 (b) and 2 (c) are adopted. As shown in (1), a method in which the block A is fixed and the block B is moved may be adopted.

In order to prevent roll transfer contamination, which is a general problem of coating due to poor drying of a thick coating portion which occurs when a coating top solution is applied or when a tail solution is removed after coating, these portions are removed by a thick film removing device. Is preferably removed. The thick film removing apparatus may be of any type, such as a roll type or a nozzle suction type, as long as it can reduce the thick film level of the coating film.

The means for moving the coater die 1 or the back roll 21 may be any means such as a hydraulic pressure, a pneumatic pressure, a stepping motor, etc., as long as the coater die 1 or the back roll 21 can be moved. However, when the back roll 21 is moved, a mechanism for coping with the fluctuation in the tension of the support web 22 is required. Further, in order to prevent an impact due to the forward and backward movement, there may be a mechanism for changing the moving speed when the movement starts or when the movement stops.

[0058]

EXAMPLE 1 A comparison between the man-hour for switching from the conventional curtain coating apparatus to the slide bead applicator and the man-hour for switching from the curtain coating apparatus of the present invention to the slide bead applicator is shown in Table 1 below. become.

[0059]

[Table 1]

A comparison between the man-hour for switching from the slide bead applicator to the conventional curtain applicator and the man-hour for switching from the slide bead applicator to the curtain applicator of the present invention is shown in Table 2 below.

[0061]

[Table 2]

The side sectional view of FIG. 7 is an example of a conventional curtain coating apparatus, and the side sectional view of FIG. 8 is an example of a slide bead coating apparatus.

By integrating the coater die and the coating liquid recovery box in this manner, generation of bubbles and contamination around the coater are suppressed, and the necessity of washing around the coater is eliminated.

Further, it is possible to omit the installation and removal of the equipment for the application liquid recovery box. For this reason, the time for changing the coating apparatus is greatly saved.

Further, by integrating the entrained air scraping equipment, the transfer time can be further reduced, and at the same time, the occurrence of coating unevenness can be eliminated by the entrained air scraping effect.

Regarding the required personnel, the application liquid recovery box and the decompression box are difficult to attach, so that three people were required in the prior art, whereas the present invention made it possible for one person to always work.

Example 2 Curtain coating was carried out at a coating solution flow rate of 2.0 to 8.0 cc / cm · sec at a coating speed of 150 to 500 m / min. The relationship was examined and the following results were obtained.

Coater advancing speed: 1 cm / sec Process contamination due to coating liquid infiltration × Coater advancing speed: 2 cm / sec Process contamination due to coating liquid infiltration × Coater advancing speed: 3 cm / sec Process contamination due to coating liquid infiltration Δ Coater advancing speed: 5 cm / Sec Process contamination due to coating liquid spreading Coater advance speed: 10 cm / sec Process contamination due to coating liquid spreading Coater advance speed: 25 cm / sec Process contamination due to coating liquid spreading Coater advance speed: 50 cm / sec Process contamination due to coating liquid spreading △ Coater advance Speed: 75 cm / sec Process contamination due to coating liquid spillage × Coater retreat speed: 1 cm / sec Process contamination due to coating liquid spillage × Coater retreat speed: 2 cm / sec Process contamination due to coating liquid spillage × Coater retreat speed: 3 cm / sec Process contamination due to coating liquid circling △ Coater retreat speed: 5 cm / sec Process contamination due to coating liquid circulating Coater retreat speed: 10 cm / sec Process contamination due to coating liquid circulating Coater retreat speed: 25 cm / sec Coating liquid Process contamination due to wraparound Coater retreat speed: 50 cm / sec Process contamination due to wraparound of coating liquid △ Coater retreat speed: 75 cm / sec Process contamination due to wraparound of coating liquid × However, ○: No process contamination due to wraparound of coating liquid △: Coating wraparound X indicates that the process contamination is practically negligible. X indicates that the process contamination due to the coating liquid spillage is severe. Thus, the forward / backward speed of the coater die is 3 to 50.
It is understood that when the flow rate is set to cm / sec, more preferably 5 to 25 cm / sec, the process contamination due to the coating liquid can be completely suppressed.

When the flow rate of the coating solution is 2.0 cc / cm · s
If the flow rate is smaller than ec or the coating speed is lower than 150 m / min, the process contamination is all as described above.

The same result was obtained with the system in which the back roll block B was moved forward and backward instead of the forward and backward movement of the coater die block A.

[0071]

According to the present invention, the drip phenomenon of the coating liquid at the start and end of the high-speed coating of the curtain coating apparatus and the phenomenon of the backing to the lower portion of the back roll are eliminated, and the process contamination and the deterioration of the product quality due to it are eliminated. As a result, it is possible to suppress unnecessary consumption of the coating solution and a decrease in the yield.

In addition, it is possible to share the slide coating with the coater die advancement method, and it is not necessary to plan a new equipment factory before starting production of the curtain coating method. We can save.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing an example of each position in an embodiment of a curtain coating apparatus according to the present invention.

FIG. 2 is a cross-sectional side view showing another example of each position in the embodiment of the curtain coating apparatus according to the present invention.

FIG. 3 is a side sectional view showing a state in which a net plate is provided in a coating liquid recovery box in the embodiment of the curtain coating device of the present invention.

FIG. 4 is a partial sectional side view showing a gap of an entrained air scraping plate of a coating liquid recovery box in the embodiment of the curtain coating device of the present invention.

FIG. 5 is a partial sectional side view showing movement of an accompanying air scraping plate of a coating liquid recovery box in the embodiment of the curtain coating device of the present invention.

FIG. 6 is a partial sectional side view showing an opening between an entrained air scraping plate of a coating liquid recovery box and a coater die in the embodiment of the curtain coating device of the present invention.

FIG. 7 is a side sectional view showing an example of a conventional curtain coating apparatus.

FIG. 8 is a side sectional view showing an example of a conventional slide bead applying device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coater dice 2 Slit 3 Slide surface 4 Coater lip 6 Edge guide 11 Coating liquid recovery box 13 Accompanying air scraping plate 14 Slanted plate 14A net plate 15 Decompression suction port 16 Pipe 17 Container 18 Decompression device connection port 19 Washing water injection port 21 Back roll 22 Support web

 ──────────────────────────────────────────────────の Continuing on the front page (72) Koji Ozaki, Koji, Inventor Konica Stock Company, No. 1, Sakuracho, Hino-shi, Tokyo

Claims (12)

[Claims] 1. A curtain coating apparatus for forming a curtain film of a coating liquid on a support web conveyed via a back roll by a coater die and an edge guide attached thereto and applying the coating liquid at a coating position. In the above, a coating liquid recovery box having an opening on the upper side adjacent to the back roll is provided integrally with the coater die and the edge guide, and the integrated block moves forward to the coating position and retreats from the coating position. A curtain coating apparatus characterized in that it is performed. 2. A curtain coating apparatus for forming a curtain film of a coating solution on a support web conveyed via a back roll by a coater die and an edge guide attached thereto and applying the coating solution at a coating position. A coating liquid recovery box having an upper opening adjacent to the back roll is provided integrally with the coater die and the edge guide, and the back roll moves to advance to the coating position and the coating position. A curtain coating device characterized in that it recedes from the curtain. 3. The curtain coating apparatus according to claim 1, wherein the coating liquid recovery box is a box-shaped member provided on both sides with a shape along a peripheral surface of a back roll. . 4. The coating liquid recovery box is located between the collision portion of the curtain film and the support web, 1 to 10 cm upstream of the support web in the transport direction of the support web, close to the support web and close to the support web. The curtain coating apparatus according to any one of claims 1 to 3, further comprising an entrained air scraping plate having a gap of 0.1 to 5.0 mm therebetween. 5. The apparatus according to claim 4, wherein said entrained air scraping plate is movable to eliminate said gap.
4. The curtain coating device according to 1. 6. The curtain coating apparatus according to claim 4, wherein the coating liquid recovery box reduces the pressure on the upstream side of the entrained air scraping plate to -10 mmAq or less. 7. The curtain coating apparatus according to claim 1, wherein the coating liquid recovery box has a water sealing function. 8. The coating liquid recovery box according to claim 1, wherein a net plate or an oblique plate is provided at a bottom portion.
8. The curtain coating device according to any one of items 7 to 7. 9. The application liquid recovery box has a function of cleaning the inside of the box.
The curtain coating device according to any one of the above. 10. A coating method, comprising applying a coating liquid to a support web using the curtain coating apparatus according to claim 1. Description: 11. A curtain coating apparatus for coating a support web conveyed via a back roll, which integrally includes a coater die, an edge guide for forming a curtain film, and a coating liquid recovery box. By forming a curtain film at a location away from the support web and advancing the integrated coater die to the coating position,
A coating method for starting coating without using a curtain liquid receiving plate, wherein a flow rate of a coating liquid is 2.0 to 8.0 cc / cm.
sec, coating speed is 150-500m / m
In the case of "in", the forward speed of the coater die is 3 to 50.
A curtain coating method, wherein the coating is performed at a retreat speed of 3 to 50 cm / sec at the end of the coater die at the end of the coating. 12. A curtain coating apparatus for coating a support web conveyed via a back roll, wherein a coater die, an edge guide for forming a curtain film, and a coating liquid recovery box are integrally provided. A coating method for starting coating without using a curtain liquid receiving plate by forming a curtain film at a location away from the support web and advancing the back roll to a coating position,
When the flow rate of the coating solution is 2.0 to 8.0 cc / cm · sec and the coating speed is 150 to 500 m / min,
Advancing speed of the back roll is 3 to 50 cm / sec,
The retreat speed of the back roll at the end of coating is 3 to 50 cm.
/ Sec, a curtain coating method.