JP2004089949A - Coating apparatus and coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus and a coating method, in particular, by which coating defects such as coating stripes or failure in the quality of a coated surface such as deposition of a solid substance on a strip can be prevented. <P>SOLUTION: The coating apparatus is used to apply a coating liquid on at least one surface of a strip carried in one direction. The apparatus is equipped with a coating bar to apply the coating liquid on the strip, a gate plate which is disposed on the upstream side of the coating bar in the carrying direction of the strip so that it is opposed to the coating bar, and a liquid supplying slit which is formed in the upstream side of the coating bar in the carrying direction of the strip and which supplies the coating liquid to the coating bar. The liquid flowing surface of the gate plate where the coating liquid flows downward, and the slit surface as the wall face of the liquid supplying slit are subjected to roughing treatment to give ≤6.3S surface roughness. The coating method is carried out by using the above apparatus. <P>COPYRIGHT: (C)2004,JPO

Description

表１の結果から、１次側堰板の塗布液流下面の表面粗さが６．３Ｓ以下の粗さの実施例１〜３においては、堰板における感光層形成液の乾き固着の発生が抑制され、塗布スジや支持体ウェブへの固着物付着などの塗布面質故障の発生が見られなかったのに対し、１次側堰板の塗布液流下面の表面が１２．５Ｓと粗かった比較例１においては、前記乾き固着および面質故障が顕著に見られた。
【００６４】
【発明の効果】
以上説明したように、本発明によれば、堰状部材の頂部や上流側の面、および前記給液スリットの内部において塗布液の乾き固着が生じることが防止でき、したがって、前記乾き固着に起因する各種の塗布面質故障が生じることのない塗布装置および塗布方法が提供される。
【図面の簡単な説明】
【図１】図１は、本発明に係る塗布装置の一例であり、支持体ウェブに製版層形成液を塗布するバーコータの一例を示す概略図である。
【符号の説明】
２　　　　塗布バー
４　　　　バー支持部材
６　　　　１次側堰板
８　　　　２次側堰板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating apparatus and a coating method, and in particular, a coating apparatus that does not cause coating surface quality failures such as occurrence of coating defects such as coating stripes and adhesion of fixed matter to a belt-like body, and the coating apparatus. It relates to the coating method used.
[0002]
[Prior art]
The lithographic printing plate is usually a grained support web obtained by concentrating at least one surface of an aluminum web which is a strip-like thin plate of pure aluminum or an aluminum alloy, and forming an anodized film on the surface if necessary. A plate-making layer forming solution such as a photosensitive layer-forming solution or a heat-sensitive layer-forming solution is applied to the surface and dried to form a photosensitive or heat-sensitive plate-making surface.
[0003]
A coating solution such as the plate making layer forming solution is generally applied by a bar coater.
[0004]
The bar coater is usually disposed along a direction perpendicular to the transport direction of the strip, and rotates in the same direction as or opposite to the transport direction, while applying a coating liquid to the strip. When the web travels, the weir plate disposed relative to the bar on the upstream side of the web travel direction (hereinafter simply referred to as “upstream side”) with respect to the web travel direction, A liquid supply slit for supplying the coating liquid is provided between the bar and the barrier plate (see, for example, Patent Document 1).
[0005]
In the bar coater, the belt-like body is conveyed so as to pass above the barrier plate and the bar, and the coating liquid is discharged from the liquid supply slit toward the support web, In general, the coating liquid is applied to the belt-like body by forming a coating liquid pool in a space formed by the bar and the barrier plate.
[0006]
In the bar coater, a part of the coating liquid discharged from the liquid supply slit flows down the weir member toward the upstream side.
[0007]
[Patent Document 1]
Japanese Patent Publication No. 58-004589 (1st page, Fig. 1)
[0008]
[Problems to be solved by the invention]
However, in the conventional bar coater, the coating liquid dries out at the top of the weir-like member, the coating liquid flow lower surface where the coating liquid flows down, and the inside of the liquid supply slit, and a solid material is generated, and the coating on the belt-shaped body In some cases, the fixed matter adheres to the application surface of the liquid, or the attached solid matter cuts off, resulting in application streaks and various application surface quality failures.
[0009]
An object of the present invention is to prevent occurrence of coating surface quality failure due to the fixed matter in the bar coater.
[0010]
[Means for Solving the Problems]
The invention described in claim 1 is a coating apparatus that applies a coating liquid to at least one surface of a belt-like body that is conveyed in a fixed direction, the coating bar that coats the coating liquid on the belt-like body, and the belt-like body Formed on the upstream side of the application bar with respect to the transport direction of the body, and on the upstream side of the application bar with respect to the transport direction of the belt A liquid supply slit that supplies the application liquid toward the application bar, and a liquid supply slit surface that is a wall surface of the liquid supply slit, , And a surface roughness finish having a roughness of 6.3 S or less.
[0011]
In the coating apparatus, since the surface roughness of the coating liquid flow lower surface and the liquid supply slit surface of the barrier plate is small, the coating liquid is dried and a sticking matter is generated, and the adhesion of the coating liquid to be adhered is dry coating. It does not occur on the flow surface and the liquid supply slit surface.
[0012]
Accordingly, there is no occurrence of coating surface quality failure such as sticking matter adhesion and coating streaks in which the sticking matter caused by the dry sticking adheres to the belt-like body.
[0013]
Here, 6.3S is the degree of surface roughness finishing defined in JIS B0601, and the coating liquid flow lower surface and the liquid supply slit surface are extracted by a reference length of 0.8 mm, and this extracted portion When the maximum height Ry, which is the height from the lowest valley to the highest mountain, is measured, it indicates that the maximum height Ry is 6.3 μm. Therefore, “surface roughness finishing with a roughness of 6.3 S or less” is a finishing in which the maximum height Ry is 6.3 μm or less.
[0014]
The bar may be a smooth bar having a smooth surface, a grooved bar in which a circumferential groove is formed, or a wire bar in which a metal wire is wound around the surface at a predetermined pitch or densely wound. There may be.
[0015]
Examples of the belt-like body include a continuous belt-like base material having flexibility, and specifically, a base material used for a photosensitive material and a magnetic recording material in addition to the support web. . Examples of the base material include the support web, photographic film base material, photographic paper baryta paper, recording tape base material, video tape base material, floppy (R) disk base material, and the like. Other examples include thin metal plates used for painted metal plates such as colored iron plates.
[0016]
Examples of the coating solution include a plate making layer forming solution described in the section of “Prior Art”, a photosensitive agent colloid solution used for forming a photosensitive layer for silver salt photography, and a magnetic layer in the magnetic recording material. And the various coating materials used for the undercoat layer, intermediate coat layer, and overcoat layer of the coated metal sheet.
[0017]
According to a second aspect of the present invention, a part of a liquid supply flow path for supplying a coating liquid to the liquid supply slit is formed, and a liquid supply pocket communicating with the liquid supply slit is provided. The inner wall surface of the pocket also relates to a coating apparatus having a surface roughness finish of 6.3S or less.
[0018]
In a coating apparatus such as a bar coater, a liquid supply pocket communicating with the liquid supply slit may be provided in a liquid supply flow path for supplying the application liquid to the liquid supply slit.
[0019]
In the coating apparatus, various different coating solutions may be used, and each time the coating solution is replaced, the inside is cleaned with the solvent used in the coating solution.
[0020]
However, in the conventional coating apparatus, the coating liquid is dry-fixed in the liquid supply pocket, and the fixed matter may adhere to the inner wall surface. Further, the fixed matter may not be removed by solvent washing.
[0021]
When the fixed matter remains on the inner wall surface of the liquid supply pocket, when a new coating liquid is supplied, the fixed matter adheres to the application surface of the belt-like body on the flow of the new coating liquid, Causes various surface quality failures.
[0022]
However, in the coating apparatus of the present invention, the inner wall surface of the liquid supply pocket is subjected to a surface roughness finish of 6.3 S or less, so that the coating liquid dries and adheres to the inner wall surface of the liquid supply pocket. Is prevented from occurring.
[0023]
Therefore, when the old coating solution is replaced with a new coating solution, the inside of the coating device only needs to be washed with a solvent, so that the coating device of the present invention has excellent cleaning properties.
[0024]
The liquid supply pocket is a small space that forms part of the liquid supply flow path and communicates with the liquid supply slit. Therefore, even if the flow rate of the coating liquid fluctuates in the liquid supply channel, the flow rate fluctuation is absorbed in the liquid supply pocket, so that the flow rate of the coating liquid in the liquid supply slit is stabilized.
[0025]
Therefore, according to the said coating device, compared with the coating device of Claim 1, it can apply | coat the coating liquid more stably, and a more uniform coating surface is obtained.
[0026]
According to a third aspect of the present invention, there is provided a downstream dam plate disposed on the downstream side of the coating bar with respect to the conveying direction of the belt-like body so as to face the coating bar, and the downstream dam plate And a downstream liquid supply slit for supplying the coating liquid toward the coating bar, and a coating liquid flow lower surface on which the coating liquid flows down on the downstream dam plate, and The downstream liquid supply slit surface which is a wall surface of the said downstream liquid supply slit is related with the coating device of Claim 1 or 2 by which surface roughness finishing of the roughness of 6.3S or less is given.
[0027]
In the coating apparatus, by supplying the coating liquid between the downstream dam plate and the coating bar, dry adhesion of the coating liquid on the downstream surface of the coating bar is prevented.
[0028]
In the coating apparatus, the downstream liquid supply slit for supplying the coating liquid between the downstream dam plate and the coating bar, and the downstream dam plate itself also have a surface roughness finish of 6.3 S or less. Is preferably applied. If the downstream side liquid supply slit and the downstream side weir plate have a surface finish of 6.3 S or less, the coating liquid can be dried and fixed in both the downstream side weir plate and the downstream side liquid supply slit. It does not occur.
[0029]
The invention described in claim 4 relates to a coating apparatus in which a clearance between at least one of the dam plate and the downstream dam plate and the coating bar is 0.5 mm or more.
[0030]
In the coating apparatus, even when the supply flow rate of the coating liquid is relatively small, a high flow rate is obtained in the liquid supply slit and the downstream liquid supply slit. Therefore, the primary side weir member and the downstream side weir plate are A uniform coating liquid flow that overflows is continuously formed.
[0031]
Therefore, dry fixation does not occur in any of the primary dam member, the downstream dam plate, the liquid supply slit, and the downstream liquid supply slit. Occurrence is also prevented more effectively.
[0032]
The invention according to claim 5 relates to a coating apparatus in which the coating bar rotates at a peripheral speed different from the traveling speed of the strip.
[0033]
In the coating apparatus, since a more stable coating liquid reservoir is formed in the space between the belt-shaped body, the coating bar, and the dam plate, a coating film with particularly high uniformity is formed.
[0034]
The invention described in claim 6 relates to a coating apparatus in which the coating bar rotates at the same peripheral speed as the traveling speed of the belt-like body.
[0035]
In the coating apparatus, since the coating bar can be driven by the belt-like body, a bar driving device for rotating the bar can be omitted.
[0036]
A seventh aspect of the present invention relates to a rotating coating device in which the coating bar rotates in a direction opposite to the traveling speed of the strip.
[0037]
In the coating apparatus, even when the transport speed of the strip is low, the difference between the peripheral speed of the coating bar and the traveling speed of the strip can be made large.
[0038]
Therefore, since a stable coating liquid reservoir is formed as in the coating apparatus according to claim 5, a coating film with particularly high uniformity is formed.
[0039]
The invention according to claim 8 relates to a coating apparatus in which the coating bar rotates in the same direction as the traveling speed of the band-shaped body.
[0040]
In the coating apparatus, even when the transport speed of the strip is high, the difference between the peripheral speed of the coating bar and the traveling speed of the strip does not become excessive, so that a stable coating liquid pool is formed. A highly uniform coating film is formed.
[0041]
The invention according to claim 9 is a coating method in which a coating liquid is applied to at least one surface of a belt-like body conveyed in a fixed direction, the coating bar for coating the coating liquid on the belt-like body, and the belt-like body Formed on the upstream side of the application bar with respect to the transport direction of the body, and on the upstream side of the application bar with respect to the transport direction of the belt A liquid supply slit that supplies the application liquid toward the application bar, and a liquid supply slit surface that is a wall surface of the liquid supply slit and a liquid supply slit surface that is the wall surface of the liquid supply slit. The present invention relates to a coating method characterized in that the coating liquid is applied using a coating apparatus formed with a surface roughness of 3S or less.
[0042]
According to the coating method, for the same reason as described in claim 1, it is possible to prevent the coating liquid from being dried and fixed on the coating liquid flow lower surface and the liquid supply slit surface of the dam member. A highly uniform coated surface can be obtained.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
1. Embodiment 1
FIG. 1 shows an example of a bar coater that is an example of a coating apparatus according to the present invention and that applies a plate-making layer forming liquid to a support web. The support web W is an example of a belt-like body in the present invention, and the platemaking layer forming liquid is an example of a coating liquid in the present invention.
[0044]
The bar coater 100 according to the first embodiment includes a coating bar 2 that applies the plate-making layer forming liquid to the grained surface Sg of the support web W conveyed in the direction of arrow a, and a plate-like bar that supports the coating bar from below. A support member 4, a primary side dam plate 6 erected so as to face the bar support member 4 and the coating bar 2 on the upstream side of the bar support member 4, and a bar on the downstream side of the bar support member 4 A secondary side dam plate 8 is provided so as to be opposed to the support member 4 and the application bar 2. The primary side dam plate 6 and the secondary side dam plate 8 correspond to the dam plate and the downstream side dam plate in the coating apparatus of the present invention, respectively.
[0045]
The application bar 2 may be a smooth bar, a grooved bar, or a wire bar.
[0046]
On the top surface of the bar support member 4, a V-order type bar holding groove 4 </ b> A for holding the application bar 2 is formed.
[0047]
All of the application bar 2, the bar support member 4, the primary side dam plate 6, and the secondary side dam plate 8 are mounted on the base 10.
[0048]
The base 10 has a shallow box shape with an open upper surface, and an upstream return application liquid reservoir 12 is formed between the upstream wall 10 </ b> A of the base 10 and the primary dam plate 6. A downstream return application liquid reservoir 14 is formed between the side wall 10 </ b> B and the secondary side weir plate 8.
[0049]
Between the primary side weir plate 6 and the bar support member 4, a primary side liquid supply slit 16 for supplying a plate making layer forming liquid to the upstream side of the coating bar 2 is provided. Similarly, a secondary liquid supply slit 18 for supplying a plate-making layer forming liquid is provided between the bar support member 4 and the secondary side dam plate 8 on the downstream side of the coating bar 2. The primary side liquid supply slit 16 corresponds to a liquid supply slit in the coating apparatus according to the present invention, and the secondary side liquid supply slit 18 corresponds to a downstream side liquid supply slit in the coating apparatus.
[0050]
A primary liquid supply pocket 20 is formed at the lower end portion of the primary liquid supply slit 16, and a secondary liquid supply pocket 22 is formed at the lower end of the downstream liquid supply slit. The primary side liquid supply pocket 20 corresponds to the liquid supply pocket in the coating apparatus according to the present invention. A concave surface is formed at the lower end of the surface of the primary side weir plate 6 facing the bar support member 4, and the concave surface forms part of the inner wall surface of the primary side liquid supply pocket 20. . Similarly, a concave surface is also formed at the lower end of the surface of the secondary side weir plate 8 facing the bar support member 4, and the concave surface forms part of the inner wall surface of the secondary liquid supply pocket 22. doing. ,
Connected to the primary side liquid supply pocket 20 and the secondary side liquid supply pocket 22 is a liquid supply line 24 for supplying the plate making layer forming liquid from a reservoir tank (not shown) in which the plate making layer forming liquid is stored. Has been. On the other hand, a return line 26 is connected to the upstream return coating solution reservoir 12 and the downstream return coating solution reservoir 14 for returning the platemaking layer forming solution to the reservoir tank.
[0051]
A pressure roller 30 is disposed on the upstream side of the bar coater 100, and the support web W is pressed against the coating bar 2 by the pressure roller 30 on the upper surface that is the surface opposite to the grained surface Sg.
[0052]
On the upstream side and the downstream side of the bar coater 100, web holding rollers 40 and 42 that are in contact with the upper surface of the support web W and hold the support web W so as to be transported along the transport path are disposed. ing.
[0053]
The surface roughness of the coating bar 2, the bar support member 4, the primary side dam plate 6, and the secondary side dam plate 8, and the inner wall surface and the bottom surface of the base 10 are 6.3S or less. Finished.
[0054]
Accordingly, the upstream side surface of the primary side weir plate 6, that is, the coating liquid flow lower surface 6 </ b> A, the primary side liquid supply slit 16, the secondary side liquid supply slit 18, the primary side liquid supply pocket 20, and the secondary side liquid supply pocket 22. , And the downstream side surface 8A of the secondary dam plate 8 are finished to a surface roughness of 6.3S or less.
[0055]
Therefore, the plate-making layer forming liquid supplied from the liquid supply conduit 24 is the coating liquid flow lower surface 6A of the primary side weir plate 6, the primary side liquid supply slit 16, the secondary side liquid supply slit 18, and the primary side supply liquid. Since neither the liquid pocket 20, the secondary side liquid supply pocket 22, nor the downstream side surface 8A of the secondary side weir plate 8 is dry-adhered, the plate-making layer caused by the solid content generated by the dry adhering Surface quality failure will not occur.
[0056]
Further, by supplying the plate-making layer forming liquid from the secondary-side liquid supply slit 18, it is possible to prevent the plate-making layer forming liquid from being dried and fixed on the downstream surface of the coating bar 2.
[0057]
In addition, even when a large fluctuation occurs in the supply amount of the platemaking layer forming liquid from the primary liquid supply pipe 24, the primary liquid supply pocket 20 and the secondary liquid supply pocket 22 reduce the fluctuation. Therefore, the plate-making layer forming liquid is supplied to the primary side liquid supply slit 16 and the secondary side liquid supply slit 18 at a stable flow rate.
[0058]
Therefore, according to the bar coater 100 according to the first embodiment, a plate making layer having high uniformity and no surface quality failure can be formed.
[0059]
【Example】
(Examples 1-3, Comparative Example 1)
One surface of an aluminum web having a width of 800 mm was subjected to brush grain treatment, alkali etching treatment, and electrolytic surface roughening in order to be grained, and then anodized to prepare a support web.
[0060]
Using the coating apparatus shown in FIG. 1, a photosensitive layer forming solution was applied as a plate making layer forming solution to the grained surface Sg of this support web and dried to form a photosensitive layer. The coating conditions for the photosensitive layer coating solution were set as follows.
[0061]
a. Thickness of the support web W ... 0.3 mm
b. Transport speed of support web W ... 100 m / min c. Bar coating amount: 20cc / m ²
d. Outer diameter of application bar 2 ... 10mm
e. Rotation speed of coating bar 2 -30rpm (reverse rotation)
f. Viscosity of photosensitive layer forming solution: 2 mPa · s
g. Liquid feeding amount S1 2.0 liters / minute i. Outer diameter of pressing roller 30 ... 50 mm
k. Clearance between primary side weir plate 6 and application bar 2 ... 0.5 to 5.0 mm
g. Surface roughness finishing of primary side dam plate ... 3.2S ~ 12.5S
h. Surface roughness of primary side liquid supply slit 16 and primary side liquid supply pocket ... 0.8S.
[0062]
The results are shown in Table 1.
[0063]
[Table 1]

From the results of Table 1, in Examples 1 to 3 where the surface roughness of the lower surface of the coating liquid on the primary side weir plate is 6.3 S or less, the occurrence of dry adhesion of the photosensitive layer forming solution on the weir plate occurs. The surface of the lower surface of the coating liquid flow of the primary side weir plate was rough as 12.5S, while the occurrence of coating surface quality failure such as adhesion of streaks on the coating streaks and the support web was not observed. In Comparative Example 1, the dry adhesion and the surface quality failure were significantly observed.
[0064]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent dry adhesion of the coating liquid on the top and upstream surfaces of the weir-like member and the inside of the liquid supply slit, and therefore, due to the dry adhesion. There are provided a coating apparatus and a coating method which do not cause various kinds of coating surface quality failures.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a bar coater that is an example of a coating apparatus according to the present invention and that coats a plate-making layer forming liquid onto a support web.
[Explanation of symbols]
2 Application bar 4 Bar support member 6 Primary side barrier plate 8 Secondary side barrier plate

Claims (9)

A coating apparatus that coats a coating liquid on at least one surface of a belt-like body conveyed in a certain direction,
An application bar for applying the application liquid to the strip;
A weir plate disposed on the upstream side of the coating bar with respect to the transport direction of the belt-like body so as to face the coating bar;
Formed between the barrier plate and the coating bar, and provided with a liquid supply slit for supplying the coating liquid toward the coating bar,
The coating liquid flow lower surface where the coating liquid flows down in the barrier plate and the liquid supply slit surface which is the wall surface of the liquid supply slit are subjected to surface roughness finishing with a roughness of 6.3 S or less. A coating device. The liquid supply pocket has a liquid supply pocket that communicates with the liquid supply slit and forms a part of a liquid supply flow path that supplies the application liquid to the liquid supply slit. The coating apparatus according to claim 1, which has been subjected to a surface roughness finish of the following roughness. Formed between the downstream side dam plate and the downstream side dam plate and the application bar, which is disposed on the downstream side of the application bar with respect to the transport direction of the belt-like body, so as to face the application bar. And a downstream liquid supply slit for supplying the coating liquid toward the coating bar,
The coating liquid flow lower surface where the coating liquid flows down on the downstream weir plate and the downstream liquid supply slit surface which is the wall surface of the downstream liquid supply slit are subjected to a surface roughness finish of 6.3 S or less. The coating apparatus according to claim 1 or 2. The coating apparatus according to any one of claims 1 to 3, wherein a clearance between at least one of the weir plate and the downstream weir plate and the coating bar is 0.5 mm or more. The coating apparatus according to any one of claims 1 to 4, wherein the coating bar rotates at a peripheral speed different from a traveling speed of the belt-shaped body. The coating apparatus according to claim 1, wherein the coating bar rotates at the same peripheral speed as the traveling speed of the belt-shaped body. The coating apparatus according to claim 1, wherein the coating bar rotates in a direction opposite to a traveling speed of the belt-shaped body. The coating apparatus according to claim 1, wherein the coating bar rotates in the same direction as the traveling speed of the belt-shaped body. A coating method in which a coating liquid is applied to at least one surface of a belt-like body conveyed in a certain direction,
A coating bar for applying the coating liquid to the strip, a weir plate disposed upstream of the coating bar with respect to the transport direction of the strip, and facing the coating bar; and the strip A liquid supply slit that is formed on the upstream side of the coating bar with respect to the body conveyance direction and that supplies the coating liquid toward the coating bar, and the coating liquid flow lower surface on which the coating liquid flows down on the barrier plate, And a coating method in which the coating liquid is applied using a coating apparatus in which a liquid supply slit surface, which is a wall surface of the liquid supply slit, has a surface roughness of 6.3 S or less.

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