JP2003175359A - Bar coating method and bar coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the generation of stepwise irregularity in the surface of a coating film at the time of coating of the dispersed particle-containing layer of an antireflection film. <P>SOLUTION: A wire bar 11 is supported by a backup member 12 and the support parts 12a and 12b are projected on both sides of the backup member 12 to support both ends of the wire bar 11. The support parts 12a and 12b are provided outside the width W1 of a product. The shearing generated in a coating solution is suppressed between the backup member 12 and the wire bar 11 to eliminate the generation of stepwise irregularity in the surface of the coating film. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar coating method and apparatus, and more particularly, to a flexible support (hereinafter referred to as "web") that is continuously running and dispersed particles (for example, matting agent particles). The present invention relates to a method and an apparatus for bar-coating a coating solution containing

[0002]

2. Description of the Related Art Antireflection films are generally used in cathode ray tube displays (CRTs), plasma display panels (PDs).
P) or an image display device such as a liquid crystal display device (LCD), which is used to prevent the deterioration of contrast and the reflection of an image due to the reflection of external light, and to reduce the reflectance by the principle of optical interference. Placed on the outermost surface of the display.

As the antireflection film, a multi-layer film in which transparent thin films of metal oxide are laminated has been conventionally commonly used. The use of a plurality of transparent thin films is to prevent reflection of light of various wavelengths. The transparent thin film of metal oxide is formed by chemical vapor deposition (CVD) method or physical vapor deposition (PVD).
It is formed by a vacuum vapor deposition method, which is a kind of physical vapor deposition method.

A transparent thin film of a metal oxide has excellent optical properties as an antireflection film, but the forming method by vapor deposition has low productivity and is not suitable for mass production.

Instead of the vapor deposition method, there has been proposed a method of producing an antireflection film by forming an optical functional layer on a transparent support by coating. Further, a low reflection film in which the reflectance is lowered by coating a layer (low refractive index layer) having a refractive index lower than that of the transparent support for antireflection is generally well known. Such an antireflection film manufacturing method is suitable for mass production because it can be continuously manufactured. A method for producing a long antireflection film is disclosed in Japanese Patent Laid-Open No. 2001-100004, and thin layer coating by bar coating is common.

[0006]

As described above, the bar coating is effective for thin layer coating as described above, but as the surface quality of the product is improved, a step-like unevenness failure (the shape of the step-like unevenness is formed). May have a slightly arched shape rather than a straight shape in the web width direction). Therefore, there is a limit to improving the surface quality, and some measure has been desired.

The present invention is intended to solve the above-mentioned problems, and it is a bar which suppresses the occurrence of step-like uneven failures without changing the formulation of the coating liquid (particularly, dispersed particles such as matting agents). An object is to provide a coating method and apparatus.

[0008]

Means for Solving the Problems As a result of intensive studies on the step-like unevenness failure, the present inventor has found that when applying a coating solution containing dispersed particles such as a matting agent, a backup bar supporting a wire bar and a bar are used. It was found that the accuracy on the order of μm cannot be maintained between the bars and the backup and the contact between the bar and the backup are mixed in the width direction, which is a major factor. That is, an irregular gap is generated in the width direction between the bar and the backup, and in the case of the coating liquid containing dispersed particles, there are a portion where the coating liquid is rubbed and a portion where the coating liquid is not rubbed. It was found that they were unevenly distributed and the surface shape eventually looked like a step.

Therefore, in the coating liquid method and apparatus of the present invention, (1) both ends of the bar are supported by the backup outside the effective product width, and (2) the flexible support is provided for the bar. It is characterized in that a weir is provided on the upstream side in the traveling direction, and the coating solution is overflowed from the weir and applied.

In addition to supporting both ends of the bar, they may be supported within the product effective width. In this case, one or more supporting portions are provided and the contact width of the supporting portion with the bar is set. 10
It is preferable that the thickness is less than mm. Further, when the weir is provided, it is preferable that the cross-sectional area of the vertical cross section of the liquid pool due to the weir in the running direction of the flexible support is 1 cm ² or more. Using the bar coating method and apparatus of the present invention, it is most preferable that the coating liquid contains a component of an antireflection film as a coating liquid, and the applied coating film is an antireflection film. Is not limited to matting agent particles for
For example, a coating liquid containing dispersed particles for imparting slipperiness, antistatic properties, and polishing properties, a coating liquid containing dispersed particles for coloring such as a white background, and a magnetic substance dispersion liquid for imparting a magnetic recording layer. The coating method and apparatus of the present invention can also be applied to the above.

[0011]

1 shows a coating head 10 in a wire bar coating device 9 of the present invention. The coating head 10 includes a wire bar 11, a backup 12 that supports the wire bar 11, and coater blocks 13 and 14. Manifolds 15, 16 are provided between the backup 12 and the respective coater blocks 13, 14.
And slots 17 and 18 are formed. A coating liquid 19 is supplied to each of the manifolds 15 and 16.

The coating solution 19 is formed in a narrow slot 17,
It is uniformly extruded in the web width direction through the web 18, so that the primary coating bead 2 is provided on the upstream side (hereinafter simply referred to as the primary side) in the feeding direction of the web W with respect to the wire bar 11.
2 is formed, and the secondary side coating bead 23 is formed on the downstream side (hereinafter simply referred to as the secondary side). The secondary coating bead 23 acts so that air is not trapped between the wire bar 11 and the backup 12. These coated beads 2
The coating liquid 19 is applied to the web W by the Nos. 2 and 23. The web W is moved to the wire bar 1 by the guide rollers 24 and 25.
You will be guided to 1.

The coating liquid 19 excessively supplied from the manifolds 15 and 16 overflows between the coater blocks 13 and 14 and the web W, and is recovered via a side groove (not shown). The supply of the coating liquid 19 to the manifolds 15 and 16 may be performed from the central portion of the manifolds 15 and 16 or from the end portions. As the material of the wire bar 11, various metals such as stainless steel can be used as long as they satisfy the strength.

As shown in FIG. 2, both ends of the wire bar 11 are supported by the both-end supporting portions 12a and 12b of the backup 12. The both-end support portions 12a and 12b are configured to support both end portions of the wire bar 11 at positions outside the product effective width W1. In this way, by supporting both ends of the wire bar 11 at positions outside the product effective width W1, the non-uniform contact condition between the wire bar 11 and the backup 12 that supports the wire bar 11 is eliminated, and an arch shape is formed. Occurrence of step unevenness can be suppressed.

In order to further suppress the step unevenness,
As shown in FIG. 3, the baffle plate 2 is provided on the primary side portion (coater block 14 side) of the backup where the coating liquid 19 is scratched up.
6 is preferably provided, and in this case, the stirring efficiency of the matting agent in the coating liquid can be increased. The gap between the upper end of the baffle plate 26 and the wire bar 11 may be appropriately changed depending on the viscosity of the coating liquid 19 and the diameter of the matting agent.
Further, instead of changing the gap or in combination with changing the gap, as shown in FIGS. 4 (A) and 4 (B), the baffle plate 27 having notches 27a, 28a of various shapes at the upper end is provided.
28 may be used. In addition, as shown in FIG.
Instead of the notch, a baffle plate 29 having a hole 29a may be used. The shapes and numbers of the notches and holes, the formation positions, and the like are not limited to those shown in the drawings, and may be appropriately changed according to the viscosity of the coating liquid, the diameter of the matting agent, and the like.

Although not shown in the case of the both-ends supporting type backup 12 as shown in FIGS. 1 to 3, a mechanism for holding bearings may be provided at both ends outside the coating device, and in this case. Can correct the self-weight deflection of the wire bar.

Further, as a method of forcing the wire bar 11 to bend due to its own weight, as shown in FIG. 5, in addition to the supporting portions 31a and 31b provided outside the product width W1, further supporting portions 31c within the product width W1 are provided. The coating head 32 having the backup 31 with increased number may be used. In addition, although the one in FIG. 5 has one in-product width support portion 31c, this may be appropriately increased according to the product width W1. As described above, by providing the support portion 31c within the product width W1, it is possible to prevent the wire bar 11 from bending due to its own weight, and to suppress the step unevenness (the step unevenness is linear) due to one rotation of the wire bar 11. can do. However, if the wire bar support width W2 of the support portion within the product width W1 is wide, arch-shaped stepwise unevenness occurs,
The wire bar support width W2 is preferably 10 mm or less, more preferably 5 mm or less.

Further, as in the above embodiment, the wire bar 1
Both ends of 1 are backup parts 12a, 31a of the support parts 12a,
Instead of the method of supporting by 12b, 31a to 31c, etc., as shown in FIG. 6, a coating head 40 of a type having a backup 39 that supports the wire bar 11 over the entire width may be used. In this case, the block 42 in which the weir 41 is provided on the primary side of the wire bar 11 is used. First, the wire bar 11 is set on the backup 39, and while being rotated, the coating liquid is supplied from a coating liquid supply device (not shown).
Then, the liquid feed amount is set so that the coating liquid uniformly overflows from the weir 41, and the web W is wrapped and coated.

The primary side weir 41 preferably has a large volume, and this volume is related to the cross-sectional area SA1 of the liquid pool by the weir 41 as shown in FIG. This cross-sectional area SA1 is 1 cm
^It is preferably ² or more, more preferably 3 cm ² or more. The cross-sectional shape of the liquid pool formed by the weir 41 is not limited to that shown in FIGS. 6 and 7, and the weir 43 has a triangular cross-section as shown in FIG.
It is also possible to use a coating head 44 having a weir, or a coating head 46 having a weir 45 having a large cross-sectional area without slots as shown in FIG. The cross-sectional shape of the liquid pool formed by the weirs 41, 43, 45 is not limited to that shown in the figure, and may be changed as appropriate.

The condition of the liquid supply amount is as follows: primary weirs 41, 43, 4
It is a necessary condition that the coating liquid overflows uniformly from No. 5, and the purpose is to prevent the liquid from stagnation (stagnation) in the weirs 41, 43, 45. Usually, it is preferable to send a liquid amount 5 to 50 times the wet coating amount.

Next, the rod diameter of the wire bar 11 will be described. As shown in FIG. 2, in the case of the coating head 10 having the backup 12 of both ends supporting type, in order to prevent the step unevenness (the step unevenness becomes a straight line in the width direction) due to its own weight deflection, the wire bar 11 It is preferable not to reduce the diameter of the bar, and in practice, it is preferable to determine the bar diameter in the range of 10 to 30 mm. Further, as shown in FIG. 5, in the case of the coating head 32 having the backup 31 having the support portion 31c within the product width in addition to the support portions 31a and 31b at both ends, a small diameter bar of 10 mm or less can also be suitably used. is there.

As shown in FIG. 6, in the case of the coating head 40 in which the volume of the liquid pool by the primary side weir 41 is increased and the coating head 40 having the backup 39 for supporting the wire bar 11 over the entire width, the self weight of the bar 11 is used. Since the deflection can be ignored, it is practically preferable that the bar diameter is in the range of 2 to 15 mm.

In the final judgment of the coating film surface state, it is necessary to consider the occurrence of vertical streaks (generally streak defects called equal pitch ribs) with respect to the coating speed, and it is necessary to increase the bar diameter. Is also limited. Therefore, in the case of bar coating,
The bar diameter will be selected according to the production capacity.

In each of the above embodiments, one end of the wire bar may be provided with a pulling device for pulling the wire bar in the axial direction to apply a tensile load to the wire bar. In this case, even if the rigidity of the wire bar rod is reduced as the diameter of the rod is reduced, uneven rotation can be suppressed. Therefore, it is possible to suppress the occurrence of step-like unevenness, which appears as an adverse effect of reducing the rod diameter, and obtain a uniform coating film surface state.

Next, an example of the layer structure of the antireflection film obtained by the coating method of the present invention will be described. FIG. 10 shows an example of the antiglare antireflection film 60, which is a transparent support 61 made of triacetyl cellulose (same meaning as the web W), a hard coat layer 62, and an antiglare layer 63 having antiglare dispersed particles 63a. , And the low-refractive-index layer 64 has a layered structure in the order. It is needless to say that the present invention is not limited to the number of layers and the layer structure as shown in FIG. 10, and is useful for bar coating containing dispersed particles such as a matting agent.

As the web W of the present invention, it is preferable to use a plastic film. Examples of the polymer forming the plastic film include cellulose ester (eg, triacetyl cellulose, diacetyl cellulose), polyamide, polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene naphthalate), polystyrene, polyolefin and the like. Of these, triacetyl cellulose, polyethylene terephthalate and polyethylene naphthalate are preferable.

An example of the hard coat layer 62 is also shown. The compound used for the hard coat layer 62 is preferably a polymer having a saturated hydrocarbon or polyether as the main chain, and the binder polymer is preferably crosslinked. To obtain a crosslinked binder polymer,
It is preferable to use a monomer having two or more ethylenically unsaturated groups.

The monomer having an ethylenically unsaturated group needs to be cured by a polymerization reaction by ionizing radiation, heat, etc. after coating. If necessary, this curing is a photopolymerization initiator,
It can be carried out by a known method using a photosensitizer and the like.

In the present invention, the antiglare layer 63 can be formed by using a high refractive index monomer or high refractive index inorganic ultrafine particles in addition to the material forming the hard coat layer 62 in the formation of the binder. . Such a high refractive index monomer preferably contains in the monomer structure at least one selected from the group consisting of an aromatic ring, a halogen atom other than a fluorine atom, a sulfur atom, a phosphorus atom and a nitrogen atom.

The high-refractive-index inorganic ultrafine particles preferably contain ultrafine particles having a particle diameter of 100 nm or less and made of at least one oxide selected from titanium, aluminum, indium, zinc, tin, antimony and zirconium.

Antiglare dispersed particles 63a put in the antiglare layer 63
For, resin or inorganic compound particles are used. The average particle size is preferably 1.0 to 10 μm, and 1.5 to
5.0 μm is more preferable.

An example of the low refractive index layer 64 is also shown. A fluorine-containing resin is used for the low refractive index layer 64, and a fluorine-containing compound (resin) that is crosslinked by heat or ionizing radiation is preferably used.

The antireflection film 60 of the present invention is particularly preferably used in a liquid crystal display device. When used for a liquid crystal display device, it is arranged on the outermost surface of the display by providing an adhesive layer on one surface. When the transparent support is triacetyl cellulose, triacetyl cellulose is used as a protective film for protecting the polarizing layer of the polarizing plate,
It is particularly preferable in terms of cost to use the antiglare antireflection film of the present invention as it is as a protective film.

[0034]

EXAMPLE FIG. 11 is a schematic view showing a manufacturing process of an antireflection film, in which a wire bar coating device 9 of the present invention is incorporated. First, the web W delivered by the delivery device 71 is delivered to the dust remover 73 while being supported by the guide rollers 72. The web W dedusted by the dust remover 73 is sent to the coating device 70, where the coating liquid is coated by the wire bar 11. After this, the UV lamp 7 is dried through the drying control box 74 and the drying zone 75.
After the coating layer is cured in 6, it is wound by the winder 77.

<Example 1> The web W has a thickness of 80.
250 g of UV-curable hard coat composition (Desolite Z-7526, 72 weight percent, manufactured by JSR Corporation) was used on the surface of the web using μm triacetyl cellulose (Fujitac, manufactured by Fuji Photo Film Co., Ltd.). A coating solution prepared by dissolving 62 g of methyl ethyl ketone and 88 g of cyclohexanone in 8.6 ml per 1 m ^{2 of} film was dried at 120 ° C. for 5 minutes and then 160 W / cm 2.
The air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) was used to irradiate ultraviolet rays to cure the coating layer to form a hard coat layer having a thickness of 5 μm.

Then, the coating solution for the antiglare layer on the hard coat layer was prepared as follows. First, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.)
52 g of 91 g, 218 g of hard coat coating liquid containing Zirconium oxide dispersion (Desolite Z-7401, manufactured by JSR Corporation)
g of methyl ethyl ketone / cyclohexanone = 40/6
Dissolved in 0 weight percent mixed solvent. The obtained solution was added with crosslinked polystyrene particles (SX-200H,
Soken Chemical Co., Ltd. 2.5 g was added, and the mixture was stirred at 5000 rpm for 1 hour with a high speed dispa, then 10 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba-Geigy) was added to form an antiglare layer coating solution. did.

As the coating device, a coating head 10 having both ends supporting backups 12 for supporting the wire bar 11 outside the product width W1 as shown in FIGS. 1 and 2 is used, and the wire bar 11 having a rod diameter of 15 mm is used. After the setting, the coating liquid was fed at a liquid amount 10 times the coating amount, overflowed as shown in FIG. 1, and the wire bar 11 was rotated at the same speed as the web W to prepare for coating.

The coating liquid is applied to the web W at a traveling speed of 10 m.
The coating amount of the wet coating was 4.2 ml per 1 m ^{2 of the} web W on the hard coat layer while running at a speed of 1 / min. The volume of the liquid pool due to the weir on the primary side is 0.5 cm ^{2 when} expressed by the sectional area SA1.
Was set.

On the antiglare layer, 200 g of methyl isobutyl ketone was added to 200 g of a heat-crosslinkable fluorine-containing polymer (JN-7221, manufactured by JSR Corporation), and the mixture was stirred to obtain a coating liquid for the low refractive index layer. After applying and drying at 80 ° C, another 12
Thermal crosslinking was performed at 0 ° C. for 10 minutes to form an antireflection film.

<Example 2> Application was carried out in the same manner as in Example 1 except that the backup was supported while supporting the entire width.

<Example 3> Coating was carried out in the same manner as in Example 1 except that the backup was supported at both ends and one point was supported within the product width (5 mm width).

<Example 4> Coating was carried out in the same manner as in Example 1 except that the bar diameter was 10 mm.

<Example 5> Coating was carried out in the same manner as in Example 1 except that the bar diameter was 5 mm.

<Example 6> Coating was carried out in the same manner as in Example 1 except that the bar diameter was 30 mm.

<Example 7> Coating was carried out in the same manner as in Example 1 except that the coating speed was 20 m / min.

The samples prepared in Examples 1 to 7 were visually evaluated for step unevenness and vertical streaks.

The results are shown in Table 1. In the evaluation of step unevenness, x is a level at which the step pitch can be clearly confirmed visually over the entire width direction, Δ is a level at which the step pitch can be confirmed thin over the entire width direction, and ○ is a width direction. On the other hand, a four-level evaluation was given, in which the step pitch can be confirmed thinly in places, and ⊚ indicates that there is no unevenness. Regarding the evaluation of the vertical stripes, x indicates that the stripes can be confirmed over the entire width direction, and the number of stripes is 10 in the width direction.
It is the case of more than the number of lines, △ is the case where the number of lines is 2 to 9 and is thin in places in the width direction, and ○ is the case where the number of lines is 1 or less and it looks very thin. Yes, ⊚ indicates that there are no streaks at all, and was evaluated on a 4-point scale.

[0048]

[Table 1]

<Embodiment 8> As shown in FIGS. 6 and 7, as in Embodiment 1 except that the backup is a full width support, the cross-sectional area SA1 by the primary weir 41 is 5 cm ² , and the bar diameter is 10 mm. It was applied in the same manner.

<Embodiment 9> The backup is supported over the entire width, and the cross-sectional area SA1 of the liquid reservoir by the primary side weir 41 is set to 3c.
The coating was performed in the same manner as in Example 1 except that the bar diameter was m ² and the bar diameter was 10 mm.

<Embodiment 10> The backup is supported over the entire width, and the cross-sectional area SA1 of the liquid pool by the primary side weir 41 is 1c.
The coating was performed in the same manner as in Example 1 except that the bar diameter was m ² and the bar diameter was 10 mm.

<Embodiment 11> The backup has a full-width support, and the cross-sectional area SA1 of the liquid pool by the primary side weir 41 is 5c.
The coating was performed in the same manner as in Example 1 except that the bar diameter was m ² and the bar diameter was 5 mm.

<Embodiment 12> The backup has a full-width support, and the cross-sectional area SA1 of the liquid pool by the primary side weir 41 is 5c.
It was applied in the same manner as in Example 1 except that the bar diameter was m ² and the bar diameter was 15 mm.

<Embodiment 13> The backup has a full-width support, and the cross-sectional area SA1 of the liquid reservoir by the primary side weir 41 is 5c.
The coating was performed in the same manner as in Example 1 except that the bar diameter was m ² and the bar diameter was 30 mm.

The samples prepared in Examples 8 to 13 were visually evaluated for stepwise unevenness.

The results are shown in Table 2. The evaluation of step unevenness was performed in the same manner as in Table 1.

[0057]

[Table 2]

From the above results, it is possible to obtain a coating film free from stepwise unevenness and streaky unevenness by backing up both ends or by increasing the volume of the liquid pool (cross-sectional area SA1) due to the primary weir. Was given. Since this method can be applied to the case of applying a coating liquid containing dispersed particles such as a matting agent in bar coating, it is clear that the coating method and apparatus are not limited to the antireflection film and have versatility. Became.

[0059]

According to the present invention, in a method or apparatus for applying a coating solution containing dispersed particles to a bar, a backing supporting both ends of the bar is used, or the flexible support is moved relative to the bar. By providing a weir on the upstream side in the direction and allowing the coating solution to overflow from the weir, it is possible to suppress the occurrence of stepwise unevenness and obtain a uniform coating film surface state.

[Brief description of drawings]

FIG. 1 is a schematic view showing a coating head of a wire bar coating device.

FIG. 2 is a perspective view showing a backup of a coating head.

FIG. 3 is a perspective view showing a backup in another embodiment in which a baffle plate is provided.

FIG. 4 is a schematic view showing an example of a baffle plate.

FIG. 5 is a perspective view showing a backup supported by both ends of the wire bar and within the product width.

FIG. 6 is a perspective view showing an application head having a weir on the primary side.

FIG. 7 is a cross-sectional view of an application head having a weir on the primary side.

FIG. 8 is a cross-sectional view of a coating head in another embodiment in which the shape of the primary weir is changed.

FIG. 9 is a cross-sectional view of a coating head in another embodiment in which the shape of the primary weir is changed.

FIG. 10 is a cross-sectional view showing an example of an antireflection film.

FIG. 11 is a schematic view showing the manufacturing process of the antireflection film.

[Explanation of symbols]

9 Wire bar coating device 10, 32, 40, 40, 44, 46 Coating head 11 wire bars 12, 31, 39 Backup 12a, 12b, 31a-31c Supporting part 13,14 coater block 19 coating liquid 22,23 coated beads 26, 27, 28 Baffle 41,43,45 weir 60 Anti-reflection film 70 Coating device 74 Drying Control Box 75 drying zone 76 UV lamp W web W1 product effective width

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Seiji Ishizuka             Fuji Photo, 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture             Within Film Co., Ltd. (72) Inventor Toshio Shibata             Fuji Photo, 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture             Within Film Co., Ltd. (72) Inventor Shinji Hikita             Fuji Photo, 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture             Within Film Co., Ltd. F-term (reference) 4D075 AC22 AC52 AC53 AC72 AC80                       AC84 AC92 AC93 CA02 CB02                       DA04 DB33 DB36 DB37 DB48                       DB53 EA07 EA19 EA21 EB16                       EB23 EC01                 4F040 AA22 AB20 AC01 BA10 BA23                       BA35 CB22 CB34 DA12 DA13                       DA20 DB22                 4F042 AA21 AA22 BA03 BA08 BA25                       DD04 DD10

Claims (9)

[Claims] 1. A bar supported by a backup,
In a bar coating method for applying a coating liquid containing dispersed particles to a continuously running flexible support, a portion that supports the bar by the backup is both ends of the bar outside the product effective width. A bar coating method characterized by the above. 2. The support portion of the bar is provided at one or more places within the product effective width, and the contact width of the support portion with the bar is 10 m.
The bar coating method according to claim 1, wherein the bar coating method is less than or equal to m. 3. A bar coating method in which a coating liquid containing dispersed particles is applied to a continuously running flexible support by a bar, the upstream side of the flexible support in the running direction of the bar. A bar coating method characterized in that a weir is provided in the weir, and the coating liquid overflows from the weir. 4. The bar coating method according to claim 3, wherein the cross-sectional area of the vertical cross section of the liquid reservoir due to the weir in the running direction of the flexible support is 1 cm ² or more. 5. The bar coating method according to claim 1, wherein the coating liquid contains a component of an antireflection film, and the applied coating film is an antireflection film. 6. A bar applicator for applying a coating liquid containing dispersed particles to a continuously running flexible support by a bar, and a backup supporting both ends of the bar outside the effective product width. A bar coating device comprising: 7. An effective width inner support portion for supporting the bar is provided within the product effective width, and a contact width of the effective width inner support portion with the bar is set to 10 mm or less. The described bar coating device. 8. A bar applicator for applying a coating liquid containing dispersed particles to a continuously running flexible support by means of a bar, wherein the flexible support is upstream in the running direction with respect to the bar. A bar coating device characterized in that a weir is provided in the weir, and the coating liquid overflows from the weir. 9. The bar coating apparatus according to claim 8, wherein the cross-sectional area of the vertical cross section of the liquid pool due to the weir in the running direction of the flexible support is 1 cm ² or more.