JP2009255061A - Curtain coating apparatus and curtain coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curtain coating apparatus and curtain coating method capable of preventing unstable motion of a coating liquid curtain film due to the influence of air surrounding the end portion of the curtain film, preventing deposition of a coating liquid on a claw of an edge guide, and preventing inward deviation of the curtain film. <P>SOLUTION: The curtain coating apparatus is provided with an ejection unit having a slit for ejecting the coating liquid; a guide unit configured to guide the coating liquid ejected from the slit onto a support member in a curtain-like manner; and a conveyance unit configured to convey the support member, wherein the guide unit contains a curtain edge guide section provided at both end portions of the coating liquid ejected in a curtain-like manner and a wind shield plate arranged so as to be in contact with the curtain edge guide section. The curtain coating method uses the curtain coating apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curtain coating apparatus and a curtain coating method, which can prevent the curtain film from shaking and prevent liquid droplets from adhering to the edge guide claw, and can suppress the curtain film from being cut off. About.

  The curtain coating method is a coating method often used in the manufacture of photographic photosensitive materials such as photographic films. As shown in FIG. 1, the coating liquid 3 is ejected from the nozzle slit, and the ejected coating liquid is curtained. A method of forming a coating film while freely falling with a curtain edge guide 2 guided in a shape and colliding with a web 5 that runs continuously, or a coating liquid 3 as shown in FIG. There is a method in which the coating liquid is moved on the slide surface 7, the coating liquid is freely dropped by a curtain edge guide 2 ′ that guides in a curtain shape, and a coating film is formed while colliding with the web 5 that runs continuously. Also, in multi-layer coating, coating liquids with different functions are discharged from each nozzle slit, and the discharged coating liquid is freely dropped by a curtain edge guide that guides in a curtain shape, and collides with a continuously running web. Curtain edge that discharges coating liquids with different functions from the slit, stacks the discharged coating liquid on the slide surface, and guides the stacked coating liquid in a curtain shape There is a method in which a coating film is formed while freely dropping with a guide and colliding with a web that runs continuously. In FIG. 1 and FIG. 2, 4 indicates a vacuum device, and 6 indicates a backup roll.

  However, in these methods, as shown in FIG. 1 and FIG. 2, there is a vacuum device 4 on the opposite side to the web conveyance of the curtain coating liquid 3, and the air entrainment phenomenon ( In the coating liquid web transfer section, the air accompanying the transport web 5 is entrained in the coating liquid and is accompanied by the web 5 for the purpose of suppressing the phenomenon that bubbles are formed in the coating liquid 3 applied to the web 5. As shown in FIG. 3, the vacuum device 4 sucks the surrounding air at the end of the coating liquid curtain film 3a as shown in FIG. When the surrounding air is entrained by the transport of (in FIG. 3, a solid arrow in the downward direction), an air flow in the direction of the broken line arrow in FIG. 3 is generated, and the coating liquid curtain becomes unstable and oscillates. . Then, the coating liquid comes off from the curtain edge guide 2, the coating liquid curtain film 3a is cut off, and the coating width becomes unstable, and the edge coating amount in the coating width direction is increased due to the cutting up. . For this reason, the product loss increases because the coating width is not uniform during production. In addition, due to an increase in the amount of coating on the edge in the coating width direction, an undried part occurs due to poor drying during production, and the coating liquid adheres to the web transport roll during production, and the web coating surface thereafter The production efficiency is reduced due to contamination, blocking at the time of winding up the product, or cutting of the web at the time of winding up due to the rising edge. In FIG. 3, 3b, 4 and 6 respectively indicate a coating solution (on the web), a vacuum device, and a backup roll.

  As shown in FIG. 4A, the curtain edge guide 101 for guiding the coating liquid in a curtain shape as shown in FIG. 4A has the flow velocity at the edge of the curtain film at the center while flowing the auxiliary liquid 103 to stabilize the curtain film 102. I try to get closer. And in order to collect | recover the auxiliary | assistant liquid 103, it attracts | sucks and collect | recovers like FIG. 4B at the curtain edge guide 101 lower end. However, since the coating liquid is also collected a little at the time of this collection, the liquid tank 107 accumulates in the claw portion 104 and the suction port 105 as shown in FIG. 4C. This is because a portion where the air flow is fast is formed by suction at the web traveling direction side of the curtain film 102 on the coating liquid contact surface of the claw portion 104 and the gas-liquid interface on the opposite side at the time of recovery. This is because the coating liquid whose part flow has slowed down dries. When the swing of the curtain film 102 is large, the amount of the liquid tub 107 increases with time at the lower end claw portion of the curtain edge guide 101 during continuous production, and the curtain film 102 held at the claw tip is held by the liquid tub. At this time, the part moves away from the auxiliary liquid 103 and comes into contact with the edge guide frame (the flow velocity at the end of the curtain film becomes slow), and the curtain film 102 is cut off. Thereby, there exists a fault that the edge part adhesion amount of a coating width direction increases. For this reason, the product loss increases because the coating width is not uniform during production. In addition, due to an increase in the amount of coating on the edge in the coating width direction, an undried part occurs due to poor drying during production, and the coating liquid adheres to the web transport roll during production, and the web coating surface thereafter There is a problem that the production efficiency is lowered due to contamination, blocking at the time of winding the product, or cutting of the web at the time of winding due to the rising edge.

In order to prevent the coating liquid curtain film from shaking and cutting off, in Patent Document 1, a porous material is used for the curtain edge guide, and the auxiliary liquid is evenly applied to the liquid contact surface with the curtain coating liquid. A curtain coating method has been proposed.
Further, Patent Document 2 proposes a curtain coating method using plate glass on the liquid contact surface of the curtain edge guide with the curtain coating liquid.
Further, Patent Document 3 proposes a curtain coating method that reduces the pressure in the upstream space in the support conveyance direction, which is blocked by the curtain film.

  However, the curtain coating method described in the prior art document is not sufficient to solve the problem that air around the curtain film coating liquid end is still entrained and the coating liquid curtain becomes unstable and sways. In addition, there is a problem that a liquid scum adheres to the edge guide claw portion, the coating liquid comes off from the curtain edge guide, and the coating liquid curtain film is cut off, leading to unstable coating width, defective products, and reduced production efficiency.

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention suppresses unstable fluctuations due to air around the edge of the curtain film coating liquid, and also prevents liquid droplets from adhering to the edge guide claw, thereby suppressing the curtain film from being cut off. An object is to provide a curtain coating apparatus and a curtain coating method.

Means for solving the problems are as follows. That is,
<1> Discharging means having a slit for discharging the coating liquid;
Guiding means for guiding the coating liquid discharged from the slit onto the support in the form of a curtain;
Conveying means for conveying the support,
The guide means includes a curtain end guide portion provided at both ends in the slit opening direction of the discharged curtain-like coating liquid, and a windshield plate disposed in contact with the curtain end guide portion. A curtain coating apparatus characterized by the above.
<2> The guide means has a slide surface,
The curtain coating apparatus according to <1>, wherein the discharging unit discharges the coating liquid onto the slide surface.
<3> The curtain coating apparatus according to <2>, wherein the guide unit includes slide surface curtain end guide portions provided at both ends of the slide surface in the slit opening direction.
<4> The curtain coating apparatus according to any one of <1> to <3>, wherein the discharge unit includes a plurality of slits.
<5> The curtain coating apparatus according to any one of <1> to <4>, wherein the windshield plate is provided on a side opposite to the conveyance direction of the support with respect to the curtain end guide portion.
<6> The curtain coating apparatus according to <5>, wherein the windshield plate is provided in parallel to the conveyance direction of the support and perpendicular to the support.
<7> The curtain coating apparatus according to <5>, wherein the windshield plate is provided perpendicular to the conveyance direction of the support and perpendicular to the support.
<8> The curtain coating apparatus according to any one of <1> to <7>, wherein the windshield has a length of 10 mm or more in a direction parallel to the support.
<9> The curtain coating apparatus according to any one of <1> to <8>, wherein the windshield has a length of 10 mm or more in a direction perpendicular to the support.
<10> The curtain coating device according to any one of <1> to <9>, wherein the curtain end guide portion is provided closer to or at the same position than the windshield with respect to the support.
<11> The curtain coating apparatus according to <10>, wherein the curtain end guide portion is provided closer to the support body by 0 mm or more and 10 mm or less than the windshield.
<12> The curtain according to any one of <1> to <11>, wherein the support side end of the windshield has an inclination so as to approach the support as it approaches an adjacent part to the curtain end guide part. It is a coating device.
<13> The curtain coating apparatus according to <12>, wherein an inclination angle of a lower end of the windshield is 0.1 ° or more and 40 ° or less.
<14> a discharge step of discharging the coating liquid from the slit;
A guide step of guiding the coating liquid discharged from the slit onto the support in the form of a curtain by guide means;
A conveying step of conveying the support,
The guide step includes a curtain end guide portion provided at both ends of the slit opening direction in the discharged curtain-like coating liquid, and a windshield plate disposed in contact with the curtain end guide portion. The curtain coating method is performed using
<15> The guide means has a slide surface,
The discharging step is the curtain coating method according to <14>, wherein the coating liquid is discharged onto the slide surface.
<16> The curtain coating method according to <15>, wherein the guide means includes slide surface curtain end guide portions provided at both ends of the slide surface in the slit opening direction.
<17> The curtain coating method according to any one of <14> to <16>, wherein the discharging step discharges from a plurality of slits.
<18> The curtain coating method according to any one of <14> to <17>, wherein the windshield plate is provided on a side opposite to the conveyance direction of the support with respect to the curtain end guide portion.
<19> The curtain coating method according to <18>, wherein the windshield plate is provided in parallel to the support conveyance direction and perpendicular to the support.
<20> The curtain coating method according to <18>, wherein the windshield plate is provided perpendicularly to a support conveyance direction and perpendicular to the support.
<21> The curtain coating method according to any one of <14> to <20>, wherein the windshield has a length of 10 mm or more in a direction parallel to the support.
<22> The curtain coating method according to any one of <14> to <21>, wherein the windshield has a length of 10 mm or more in a direction perpendicular to the support.
<23> The curtain coating method according to any one of <14> to <22>, wherein the curtain end guide portion is provided closer to or at the same position than the windshield with respect to the support.
<24> The curtain coating method according to <23>, wherein the curtain edge guide portion is provided closer to the support body by 0 mm or more and 10 mm or less than the windshield.
<25> The curtain according to any one of <14> to <24>, wherein the support side end of the windshield has an inclination so as to approach the support as it approaches an adjacent part to the curtain end guide part. Application method.
<26> The curtain coating method according to <25>, wherein an inclination angle of the lower end of the windshield is 0.1 ° or more and 40 ° or less.

  According to the present invention, conventional problems can be solved, unstable fluctuation due to air around the curtain film coating liquid edge is suppressed, and liquid droplets are prevented from adhering to the edge guide claw. Thus, it is possible to provide a curtain coating apparatus and a curtain coating method that suppress the curtain film from being cut off.

FIG. 1 is a cross-sectional perspective view showing a configuration example of a conventional curtain coating apparatus. FIG. 2 is a cross-sectional perspective view showing another configuration example of a conventional curtain coating apparatus. FIG. 3 is a schematic top view showing the configuration around the edge of the coating liquid curtain film in the conventional curtain coating apparatus. FIG. 4A is a perspective view showing a conventional curtain coating apparatus. FIG. 4B is a partially enlarged view of FIG. 4A. FIG. 4C is an explanatory diagram illustrating a mechanism by which a liquid scum is formed on the nail portion during curtain application. FIG. 5A is a schematic configuration diagram showing the configuration of the curtain coating apparatus according to the first embodiment of the present invention. FIG. 5B is a schematic configuration diagram during operation of the first embodiment of the curtain coating apparatus according to the present invention. FIG. 6A is a schematic perspective view showing the configuration around the curtain film end in the first embodiment of the curtain coating apparatus according to the present invention. FIG. 6B is a schematic top view showing the configuration around the edge of the curtain film in one embodiment of the curtain coating apparatus according to the present invention. FIG. 7 is a schematic top view showing the configuration around the edge of the curtain film in the second modification of the windshield of the curtain coating apparatus according to the present invention. FIG. 8 is a schematic perspective view showing the configuration around the edge of the curtain film in the first modification of the windshield plate of the curtain coating apparatus according to the present invention. FIG. 9 is an explanatory diagram for explaining the movement of the curtain guide edge and the coating liquid during manufacturing. FIG. 10A is a schematic configuration diagram showing the configuration of the curtain coating apparatus according to the second embodiment of the present invention. FIG. 10B is a schematic diagram of a configuration of the curtain coating apparatus according to the second embodiment of the present invention during operation. FIG. 11A is an explanatory diagram schematically illustrating “cut-off: none” in Table 1. FIG. 11B is an explanatory diagram schematically illustrating “cut-off: present” in Table 1.

The curtain coating apparatus of the present invention includes a discharge means having a slit for discharging a coating liquid,
Guiding means for guiding the coating liquid discharged from the slit onto the support in the form of a curtain;
A conveying means for conveying the support, and further includes other means as necessary.

The guide means includes a curtain end guide portion provided at both ends in the slit opening direction of the discharged curtain-like coating liquid, and a windshield plate disposed in contact with the curtain end guide portion (without a gap). And have.
The windshield plate may be (1) provided parallel to the support transport direction and perpendicular to the support, or (2) provided perpendicular to the support transport direction and perpendicular to the support. preferable.
The length (width) of the windshield plate in the parallel direction with respect to the support is not particularly limited and may be provided over the entire parallel direction of the support. However, the length is preferably 10 mm or more, and more preferably 10 mm to 30 mm. .
The length (height) of the windshield plate in the vertical direction with respect to the support is not particularly limited, and may be provided over the entire vertical direction of the support, but is preferably 10 mm or more, and more preferably 10 mm to 60 mm. preferable.

Hereinafter, the curtain coating apparatus of the present invention will be described in more detail with reference to the drawings.
The embodiments described below are preferred embodiments of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

<First Embodiment>
FIG. 5A is a schematic configuration diagram showing the configuration of the curtain coating device according to the first embodiment of the present invention, and FIG. 5B is a schematic configuration of the curtain coating device according to the present invention during operation of the first embodiment. FIG.
In the present embodiment, the curtain coating head 1 that is a discharge means that holds the coating liquid and has slits discharges the curtain-shaped coating liquid 3 in the direction of gravity (freely drops), and the discharged coating liquid. Is guided by the curtain edge guide 2 which is a curtain end guide provided at both ends of the curtain-like coating liquid 3 and is guided onto the web 5 which is a support. The web 5 is conveyed in one direction at a constant speed by a conveying means including a backup roll 6 and other members (not shown). At this time, a vacuum device 4 is provided upstream of the curtain-shaped coating liquid 3 in the conveyance direction of the web 5, and the space surrounded by the curtain edge guide 2, the curtain-shaped coating liquid 3, the web 5 and the like is decompressed. Yes. Further, the windshield plate 9 is disposed adjacent to the curtain edge guide 2, and has an effect of blocking the turbulence of the air current around the end portion in the curtain-shaped coating liquid 3 generated by the conveyance of the web 5 and the vacuum device 4. In addition, 3a shows a coating liquid (curtain film), 3b shows a coating liquid (on a web).

The slit of the curtain coating head 1 may have any shape as long as it can be discharged in a curtain shape. Preferably, the slit has a rectangular cross section having a sufficient length (slit opening direction) with respect to the slit width. The slit width and length can be arbitrarily designed from the viscosity of the coating liquid, the discharge amount, the size of the web to be used, and the like.
There may be a plurality of slits. In the case of having a plurality of slits, it is preferable that different coating liquids are ejected from the respective slits, and the ejected coating liquids are laminated and coated on the support.

In the present invention, the curtain edge guide 2 may be anything as long as it can form a curtain film, and a conventionally known one can be applied as it is.
In the present invention, any coating solution 3 may be used as long as it can form a curtain film, and a conventionally known coating solution 3 can be applied as it is.

  The vacuum device 4 may be any device capable of being sucked and decompressed, and a known device can be applied. Moreover, the conveyance means containing the backup roll 6 should just be the structure which can convey the web 5, and can apply a well-known thing.

  The web 5 is a base material on which a coating liquid such as paper, film, thin film metal or the like is applied to the surface, and the surface may be coated.

FIG. 6A is a schematic front view showing a configuration around a curtain film end portion in the first embodiment of the curtain coating apparatus according to the present invention, and FIG. 6B is a curtain in one embodiment of the curtain coating apparatus according to the present invention. It is an upper surface schematic diagram which shows the structure around a film | membrane edge part.
As shown in FIGS. 6A and 6B, a windshield plate 9 is attached to the lower end of the curtain edge guide 2 and applied to the coating liquid 3a flowing in a curtain shape on the opposite side of the web 5 conveying direction, thereby applying the coating liquid curtain film. By blocking the turbulence of the airflow that is formed on the opposite side of the web conveyance direction from the curtain edge guide 2 acting on the end of the curtain 3a, the unstable fluctuation of the curtain film 3a is suppressed, and the curtain film 3a of the curtain edge guide 2 is suppressed. Cutting up can be suppressed.

  In the present embodiment, the windshield plate 9 is provided perpendicular to the web 5 conveyance direction and perpendicular to the web 5. According to this configuration, it is possible to block the turbulence of the airflow that is made on the opposite side of the web conveyance direction from the curtain edge guide 2 acting on the end of the coating liquid curtain film 3a, and to suppress the unstable fluctuation of the curtain film 3a. The curtain film 3a can be prevented from being cut off by the curtain edge guide 2.

  Examples of the material of the windshield 9 include metals such as iron, stainless steel, and aluminum, and resins such as Teflon (registered trademark) and PET, but are not particularly limited.

The windshield 9 of the present invention is preferably a plate-like member having a width, a height, and a thickness.
The windshield 9 preferably has a length of 10 mm or more in the direction parallel to the web 5 (the width direction of the windshield 9). By setting the width direction of the windshield 9 to 10 mm or more, the turbulence of the air flow that is formed on the opposite side of the web conveyance direction from the curtain edge guide 2 acting on the end of the coating liquid curtain film 3a can be blocked, and the curtain film 3a is unstable. The fluctuation of the curtain film 3a at the curtain edge guide 2 can be suppressed.
Further, the windshield 9 preferably has a length of 10 mm or more in the direction perpendicular to the web 5 (the height direction of the windshield 9). By setting the windshield plate 9 to 10 mm or more in the height direction, the turbulence of the air flow that is on the opposite side of the web conveyance direction from the curtain edge guide 2 acting on the end of the coating liquid curtain film 3a can be blocked, and the curtain film 3a is unstable. The fluctuation of the curtain film 3a at the curtain edge guide 2 can be suppressed.

  Moreover, the structure which the lower end (web 5 side edge part) of the curtain edge guide 2 of this invention is a proximity | contact or the same position with respect to the web 5 rather than the lower end (web 5 side edge part) of the windshield 9 is preferable. By adopting such a configuration, the gap between the lower end of the curtain edge guide 2 and the web 5 can be narrowed, the ingress of the surrounding air is reduced, the unstable fluctuation of the curtain film 3a is suppressed, and the curtain film in the curtain edge guide 2 is suppressed. The cut-off of 3a can be suppressed.

  Furthermore, it is preferable that the curtain edge guide 2 of the present invention is provided closer to the web 5 than the windshield 9 by 0 mm or more and 10 mm or less. When separated from the windshield 9 by 10 mm or more, the curtain edge guide 2 cannot block the turbulence of the air flow that is on the opposite side of the web conveyance direction from the curtain edge guide 2 acting on the end of the coating liquid curtain film 3a, and the curtain film 3a Fluctuates and the curtain film 3a is cut off at the curtain edge guide 2.

<First Modification of Windshield>
FIG. 8 is a schematic front view showing the configuration around the edge of the curtain film in the first modification of the windshield of the curtain coating apparatus according to the present invention.
The lower end (the end portion on the web 5 side) of the windshield plate 9 ′ in the present embodiment has an inclination so as to approach the web 5 as it approaches the curtain edge guide 2.
According to such a configuration, for example, as shown in FIG. 9, when the coating liquid curtain film 3 a moves to the web position on the backup roll 6 at the start of manufacture, it sways and adheres to the windshield 9 ′. The coating liquid 3 attached to 'flows to the lower end, but by having the above inclination, the coating liquid 3 attached to the windshield 9' on the web 5 by moving to the curtain edge guide 2 side along the inclination. It is possible to prevent coating defects (blocking due to a large amount of liquid adhering) due to falling.

  At this time, it is preferable that the inclination angle of the windshield plate 9 ′ is 0.1 ° to 40 °. If the angle of inclination is larger than 40 °, the turbulence of the air flow that is formed on the opposite side of the web conveyance direction than the curtain edge guide 2 acting on the end of the coating liquid curtain film 3a cannot be blocked, the curtain film fluctuates, and the curtain edge guide Curtain film is cut off.

<Second modification of windshield>
FIG. 7 is a schematic top view showing the configuration around the edge of the curtain film in the second modification of the windshield of the curtain coating apparatus according to the present invention.
In the present embodiment, the windshield plate 9 is provided parallel to the web 5 conveyance direction and perpendicular to the web 5. According to this configuration, it is possible to block the turbulence of the airflow that is made on the opposite side of the web conveyance direction from the curtain edge guide 2 acting on the end of the coating liquid curtain film 3a, and to suppress the unstable fluctuation of the curtain film 3a. The curtain film 3a can be prevented from being cut off by the curtain edge guide 2.

<Second Embodiment; Modification of Curtain Coating Device>
FIG. 10A is a schematic configuration diagram showing the configuration of the curtain coating apparatus according to the second embodiment of the present invention, and FIG. 10B is a schematic configuration during operation of the curtain coating apparatus according to the second embodiment of the present invention. FIG.
The guide means of the present invention preferably has a slide surface 7, and more preferably has slide surface curtain end guide portions (slide portion edge guides) 8 provided at both ends of the slide surface 7 in the slit opening direction. .
As the configurations of the slide surface 7 and the slide surface curtain end guide portion 8, the configuration shown in FIG. 2 can be applied as it is. Since the configuration other than the slide surface 7 and the slide surface curtain end guide portion 8 is the same as that of the first embodiment of the curtain coating apparatus described above, the description thereof is omitted.

The configuration of the second embodiment of the curtain coating apparatus according to the present invention will be described below with reference to FIGS. 10A and 10B.
In such an embodiment, the slide curtain coating head 1 ′, which is a discharge means that holds the coating liquid and has slits, discharges the coating liquid 3 ′ onto the slide surface 7 and is layered on the slide surface 7. The discharged coating liquid 3 ′ is guided by a slide edge guide 8 which is a curtain edge guide provided at both ends (ends in the slit longitudinal direction in the drawing) of the layered coating liquid, and slide surfaces 7 is slid and freely falls in the direction of gravity from the downstream end in the sliding direction of the sliding surface to form a curtain. At this time, the coating liquid 3 ′ is guided by the curtain edge guide 2 that is a curtain end guide provided at both ends of the curtain-shaped coating liquid 3 ′ and guided onto the web 5 that is a support. The web 5 is conveyed in one direction at a constant speed by a conveying means including a backup roll 6 and other members (not shown). In addition, a vacuum device 4 is provided upstream of the curtain-shaped coating liquid 3 ′ in the conveying direction of the web 5 to depressurize the space surrounded by the curtain edge guide 2, the curtain-shaped coating liquid 3 ′, the web 5 and the like. ing. Further, the windshield 9 is disposed adjacent to the curtain edge guide 2, and has an effect of blocking the turbulence of the air current around the end of the curtain-like coating liquid 3 generated by the conveyance of the web 5 and the vacuum device 4.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
A windshield plate 9 as shown in FIG. 6 is parallel to the opposite side of the web conveyance direction at the lower end of the curtain edge guide 2 of the curtain coating apparatus as shown in FIG. 1 (in the conveyance direction of the web 5). The web 5 (paper) was coated at a coating speed of 400 m / min, a coating width of 250 mm, and a nozzle slit discharge coating liquid flow rate of 3000 g / min.

  At this time, windshield 9 (material: PET film): width 30 mm × height 60 mm × thickness 175 μm, distance of windshield 9 to web 5: equivalent to distance of curtain edge guide 2 to web 5, vacuum device 4 suction The pressure was -3 kPa, and the amount of water flowing along the curtain edge guide 2 was 30 cc / min.

The coating solution had a viscosity of 300 mPa · s and a static surface tension of 35 mN / m, and had the following composition.
(Coating solution composition)
Polyvinyl alcohol: 85 parts by mass Green pigment: 5 parts by mass Water: 915 parts by mass

Then, the presence or absence of the curtain film being cut off at the curtain edge guide 2 under the above application conditions and the liquid state of the edge guide claw portion were evaluated. The results are shown in Table 1.
[Evaluation criteria for curtain film cut-off]
◎: Curtain film is not cut off for 24 hours ○: Curtain film is cut off after 2-3 hours ×: Curtain film is cut off after 1 hour

[Evaluation criteria for liquid state of edge guide claw part]
○: A small amount of liquid in the nail △: A small amount of liquid in the nail ×: A large amount of liquid in the nail

(Example 2)
2 is parallel to the opposite side of the web conveyance direction with respect to the coating liquid flowing through the windshield plate 9 as shown in FIG. 6 at the lower end of the curtain edge guide 2 'of the curtain coating apparatus as shown in FIG. The coating and evaluation were performed in the same manner as in Example 1, except that the mounting was performed perpendicularly to the web 5. The results are shown in Table 1.

(Example 3)
As shown in FIG. 7, the windshield plate 9 of the second embodiment is perpendicular to the opposite side of the web conveyance direction (parallel to the conveyance direction of the web 5) and to the web 5 with respect to the coating liquid flowing in a curtain shape It attached vertically and performed the same coating and evaluation as Example 2. The results are shown in Table 1.

Example 4
The horizontal direction length (width) of the windshield 9 of Example 2 was set to 10 mm, and coating and evaluation similar to Example 2 were performed. The results are shown in Table 1.

(Example 5)
The horizontal direction length (width) of the windshield 9 of Example 2 was set to 5 mm, and coating and evaluation similar to Example 2 were performed. The results are shown in Table 1.

(Example 6)
The vertical coating length (height) of the windshield 9 of Example 2 was set to 10 mm, and the same coating and evaluation as in Example 2 were performed. The results are shown in Table 1.

(Example 7)
The vertical coating length (height) of the windshield 9 of Example 2 was set to 5 mm, and the same coating and evaluation as in Example 2 were performed. The results are shown in Table 1.

(Example 8)
The separation distance with respect to the web 5 of the windshield 9 of Example 2 was increased 5 mm from the separation distance with respect to the web 5 of the curtain edge guide 2, and the same coating and evaluation as in Example 2 were performed. The results are shown in Table 1.

Example 9
The distance from the web 5 of the windshield 9 of Example 2 to the web 5 was shortened by 10 mm from the distance from the web 5 of the curtain edge guide 2, and the same coating and evaluation as in Example 2 were performed. The results are shown in Table 1.

(Example 10)
Coating and evaluation in the same manner as in Example 2 were performed with the separation distance of the windshield 9 of Example 2 from the web 5 increased by 15 mm from the separation distance of the curtain edge guide 2 from the web 5. The results are shown in Table 1.

Example 11
The distance from the web 5 of the windshield 9 of Example 2 to the web 5 was shortened by 2 mm from the distance from the web 5 of the curtain edge guide 2, and the same coating and evaluation as in Example 2 were performed. The results are shown in Table 1.

Example 12
The lower end of the windshield 9 of Example 2 was inclined by 40 ° in the width direction so as to descend toward the curtain edge guide 2 as shown in FIG. 8, and coating and evaluation similar to those of Example 2 were performed. The results are shown in Table 1.

(Example 13)
The lower end of the windshield 9 of Example 2 was inclined 45 ° in the width direction so as to descend toward the curtain edge guide 2 as shown in FIG. 8, and coating and evaluation similar to Example 2 were performed. The results are shown in Table 1.

(Example 14)
The lower end of the windshield 9 of Example 2 was inclined by 1 ° so as to descend toward the curtain edge guide 2 in the width direction as shown in FIG. 8, and coating and evaluation similar to those of Example 2 were performed. The results are shown in Table 1.

(Comparative Example 1)
The windshield plate 9 of Example 1 was removed, and coating and evaluation similar to Example 1 were performed. The results are shown in Table 1.

(Comparative Example 2)
The windshield 9 of Example 2 was removed, and coating and evaluation similar to Example 2 were performed. The results are shown in Table 1.

  In Table 1, “cut-off: no” and “cut-off: present” refer to the respective schematic explanatory diagrams shown in FIGS. 11A and 11B.

  The curtain coating apparatus according to the present invention of Examples 1 to 14 can suppress the liquid scum from adhering to the edge guide claw part as compared with Comparative Examples 1 and 2, and is not caused by air around the curtain film coating liquid end part. It was found that stable fluctuation can be suppressed and the curtain film can be prevented from being cut off.

  The curtain coating apparatus and the curtain coating method of the present invention are suitably used for the production of, for example, silver halide photographic light-sensitive materials, magnetic recording materials, pressure / heat-sensitive recording paper, art paper, coated paper, and ink jet recording sheets.

Japanese Patent Laid-Open No. 11-188299 JP 2001-46939 A JP 2003-71353 A

Claims (14)

A discharge means having a slit for discharging the coating liquid;
Guiding means for guiding the coating liquid discharged from the slit onto the support in the form of a curtain;
Conveying means for conveying the support,
The guide means includes a curtain end guide portion provided at both ends in the slit opening direction of the discharged curtain-like coating liquid, and a windshield plate disposed in contact with the curtain end guide portion. A curtain coating device characterized by the above. The guiding means has a sliding surface;
The curtain coating apparatus according to claim 1, wherein the discharging unit discharges the coating liquid onto the slide surface.   The curtain coating apparatus according to claim 2, wherein the guide means includes slide surface curtain end guide portions provided at both ends of the slide surface in the slit opening direction.   The curtain coating apparatus according to any one of claims 1 to 3, wherein the discharge means has a plurality of slits.   The curtain coating device according to any one of claims 1 to 4, wherein the windshield plate is provided on a side opposite to the conveyance direction of the support with respect to the curtain edge guide portion.   The curtain coating apparatus according to claim 5, wherein the windshield plate is provided in parallel with the conveyance direction of the support and perpendicular to the support.   The curtain coating apparatus according to claim 5, wherein the windshield plate is provided perpendicular to the transport direction of the support and perpendicular to the support.   The curtain coating apparatus according to any one of claims 1 to 7, wherein the windshield has a length of 10 mm or more in a direction parallel to the support.   The curtain coating apparatus according to any one of claims 1 to 8, wherein the windshield has a length of 10 mm or more in a direction perpendicular to the support.   The curtain coating apparatus according to any one of claims 1 to 9, wherein the curtain end guide portion is provided closer to or at the same position than the windshield plate with respect to the support.   The curtain coating apparatus according to claim 10, wherein the curtain end guide portion is provided closer to the support body by 0 mm or more and 10 mm or less than the windshield plate.   The curtain coating apparatus according to any one of claims 1 to 11, wherein the windshield plate has an inclination such that the support side end portion approaches the support body as it approaches an adjacent portion to the curtain end guide portion.   The curtain coating apparatus according to claim 12, wherein an inclination angle of the lower end of the windshield is 0.1 ° or more and 40 ° or less. A discharge step of discharging the coating liquid from the slit;
A guide step of guiding the coating liquid discharged from the slit onto the support in the form of a curtain by guide means;
A conveying step of conveying the support,
The guide step includes a curtain end guide portion provided at both ends of the slit opening direction in the discharged curtain-like coating liquid, and a windshield plate disposed in contact with the curtain end guide portion. A curtain coating method characterized by being performed using