JP4403352B2 - Coating and drying method and apparatus, and method for producing support with dry coating film using the apparatus - Google Patents

Description

表１から分かるように、遮風パネル２２とウェブ１２との距離ｄが３０ｍｍよりも大きい比較例２は、塗布面にスジやムラが発生しているのに対し、距離ｄが３０ｍｍである実施例３では、良好な塗布面が得られた。また、距離ｄが１．５ｍｍである比較例１は、スジやムラが発生しているのに対し、距離ｄが３ｍｍである実施例２では、良好な塗布面が得られた。
【００３５】
【発明の効果】
以上説明したように本発明に係る塗布乾燥方法及び装置によれば、気流規制手段を設けることによって、支持体の塗布面に直交方向から風が当たることを防止するとともに、塗布面上の気流を前記支持体の走行方向に規制したので、空調エアなどの風に影響されてウェブ上の塗布液が流動することを防止でき、スジやムラのない塗布面を得ることができる。
【図面の簡単な説明】
【図１】本発明に係る塗布乾燥装置の構成を模式的に示す側面図
【図２】遮蔽パネルを支持する送りねじ機構を示す側面図
【図３】本発明に係る塗布乾燥装置の作用を示す説明図
【図４】ウェブ速度と風速分布の関係を示す説明図
【符号の説明】
１０…塗布乾燥装置、１２…ウェブ、１４…塗布装置、１６…乾燥装置、１８…バックアップローラ、２０…塗布ヘッド、２２…遮風パネル、２４…送りねじ機構、２６…支柱、２８…送りねじ、３０…駒部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating / drying method and apparatus, and more particularly to a coating / drying method and apparatus for applying a coating solution such as a photosensitive material on a sheet-like or belt-like traveling support and drying it.
[0002]
[Prior art]
For image recording materials such as photographic films, various electronic display materials, and various recording materials, a coating solution such as a photosensitive material is applied to a flexible belt (hereinafter referred to as a web) such as a plastic film with a coating device. It is manufactured by drying this coating solution with a drying device.
[0003]
The coating apparatus is installed in an air-conditioning room such as a clean room, and the coating liquid is applied to the web in a clean environment in which dust and the like are not scattered. The applied coating solution is dried by blowing dry air onto the web with a drying device. The coating device and the drying device ensure that the heat of the drying device is not transmitted to the coating device, and that the dry air, which is hot air, is not immediately applied to the coating surface of the web, or that a space for disposing the related devices is secured. Therefore, a predetermined distance (for example, 3 m) is provided, and a web travel line is formed between the coating device and the drying device.
[0004]
[Problems to be solved by the invention]
However, in the conventional coating and drying apparatus, there is a possibility that the coating liquid applied to the web flows due to the air-conditioned air, and streaks and unevenness are generated on the coating surface. In particular, when a low-viscosity coating liquid or a coating liquid colored with a dye or pigment is applied to a web running at high speed, the coating liquid is susceptible to the influence of air-conditioning air. If the air speed of the air-conditioning air is reduced, this problem can be solved. However, if the air-conditioning environment is changed, dust or the like may scatter and adhere to the coating layer, which may cause a coating defect.
[0005]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a coating and drying method and apparatus capable of obtaining a coated surface free from streaks and unevenness without changing the air conditioning environment.
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention, in order to achieve the above object, the coating liquid is applied in a coating and drying method in which a coating liquid is applied to a traveling sheet-like or belt-like support and the coating liquid is dried. The coating surface of the support is covered with a panel in at least a part of the section from the start to drying with hot air, and the distance between the coating surface and the panel is adjusted by adjusting the distance between the panel and the coating surface . the air flow in the running direction of the support, and characterized in that regulated only in the direction of travel of the component of the support in.
[0007]
In order to achieve the above object, the invention according to claim 2 is a coating / drying apparatus in which a coating liquid is applied to a traveling sheet-like or belt-like support by a coating apparatus, and the coating liquid is dried by a drying apparatus. A panel is disposed so as to cover at least a part of the coating surface of the support that travels between the coating device and the drying device, and the airflow in the travel direction of the support between the panel and the coating surface , and a panel for restricting only the traveling direction of the component of the support, and is characterized in that a means for adjusting the distance between the panel and the coated surface.
[0008]
According to invention of Claim 1 and 2, by providing a panel , it can prevent that a wind strikes the application surface of a support body from an orthogonal direction . In addition, by adjusting the distance between the coating surface and the panel and restricting the air flow on the coating surface to only the component in the traveling direction of the support, the air flow that flows in the direction opposite to the traveling direction of the support There is no influence, the generation of vortex on the coating surface can be prevented, and coating without streaks or unevenness can be performed. Furthermore, even if the point at which the speed component becomes zero varies depending on conditions such as the viscosity of the coating liquid, the coating amount, the travel speed of the support (web), and the wind speed of the air conditioning air, there is no streaking or unevenness. Can be performed stably.
[0009]
According to the third aspect of the present invention, by adjusting the distance between the panel and the coating surface within the range of 2 mm or more and 30 mm or less by the adjusting means, it is possible to reliably prevent the influence of the conditioned air.
[0011]
According to the invention described in claim 4, since the panel is covered within 0.5 seconds after the support is applied, it is possible to prevent the air-conditioning air from being adversely affected immediately after the application.
[0012]
According to the fifth aspect of the present invention, since the hole for allowing the evaporation substance of the coating liquid to escape is provided in the panel , it is possible to prevent the evaporation substance from escaping and diffusing from the hole and filling the evaporation substance.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a coating and drying method and apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
[0014]
FIG. 1 is a side view schematically showing a configuration of a coating and drying apparatus according to the present invention.
[0015]
As shown in the figure, the coating and drying apparatus 10 includes a coating apparatus 14 that applies a coating liquid to a web 12 that runs continuously, and a drying apparatus 16 that dries the coating liquid, and the coating apparatus 14 and the drying apparatus 16. Are installed in air conditioning rooms such as clean rooms. The air conditioning room maintains a clean state by, for example, downflowing clean air-conditioned air from the ceiling surface. The web 12 that runs continuously includes polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polypropylene (PP), plastic films such as cellulose film such as triacetyl cellulose (TAC), and metals such as aluminum. The foil, various papers, or a laminate of these can be raised. The thickness of the film is about 5 to 200 μm when PET is taken as an example. Furthermore, the traveling speed of the web 12 is set to about 10 to 500 m / min, for example.
[0016]
The coating device 14 includes a backup roller 18 and a coating head 20, pushes the coating solution from the tip of the coating head 20, and forms a bead between the web 12 wound around the backup roller 18 and the coating head 20. Thereby, a coating liquid is apply | coated to the web 12 via a bead. The web 12 on which the coating liquid has been applied travels obliquely upward toward the drying device 16. The coating apparatus is not limited to the extrusion type shown here, but may be a roll coater type, a gravure coater type, a slide coat type, or other coating methods.
[0017]
Further, as a coating solution to be applied by the coating device 14, a polymer solution, a photosensitive material, a recording material, a dispersion, etc. dissolved in water or a solvent are used. As the properties of the coating solution, those having a viscosity of 0.7 to 1000 cp, a surface tension of 20 to 50 dyne / cm, and a specific gravity of about 0.8 to 1.3 are used.
[0018]
On the other hand, the drying device 16 is disposed downstream of the coating device 14 with respect to the traveling direction of the web 12, and blows dry air onto the web 12 to dry the coating solution on the web 12. The drying device 16 and the coating device 14 prevent the heat during drying from adversely affecting the coating device 14, and do not immediately apply hot air to the coating surface of the web 12, or related devices. In order to secure the storage space, a predetermined distance is provided.
[0019]
Between the drying device 16 and the coating device 14, a wind shielding panel 22 is provided on the coating surface (upper surface) side of the web 12. The wind shield panel 22 is formed in a band shape wider than the web 12 by, for example, a 2 mm thick anodized plate. For example, when the web 12 is 1.2 m wide, the wind shield panel 22 is formed to be 1.5 m wide. Has been. In addition, the windshield panel 22 is disposed in the vicinity of the coating device 14 and the drying device 16 at both ends in the running direction of the web 12. For example, the upstream end of the wind shield panel 22 is disposed at a position 200 mm from the tip of the coating head 20, and the web 12 is covered by the wind shield panel 22 within 0.5 seconds after coating. ing. Note that the thickness, size, material, and the like of the wind shield panel 22 are not limited to those described above.
[0020]
Further, the wind shield panel 22 is supported via a means for adjusting the distance from the web 12, for example, a feed screw mechanism 24 shown in FIG. The feed screw mechanism 24 includes a support 26 installed perpendicular to the traveling web 12, a feed screw 28 rotatably supported by the support 26, and a screw screw 28 and a guide to the support 26. The windshield panel 22 is supported by the piece member 30. The feed screw 28 is rotated by a motor (not shown). By the rotation of the feed screw 28, the piece member 30 guided by the support column 26 slides up and down, and the wind shield panel 22 moves up and down. Thereby, the space | interval of the windshield panel 22 and the web 12 is adjusted. The distance between the windshield panel 22 and the web 12 is adjusted according to the traveling speed of the web 12, the viscosity and coating amount of the coating liquid, the wind speed of the air-conditioning air, and the like, for example, in the range of 3 to 30 mm. By adjusting the position of the wind shield panel 22 as described above, it is possible to prevent the wind from being applied to the application surface of the web 12 from the orthogonal direction (that is, from above), and to restrict the airflow on the web 12 in the traveling direction of the web 12. can do.
[0021]
Next, the operation of the coating / drying apparatus 10 configured as described above will be described.
[0022]
When the windshield panel 22 is not provided, the wind speed distribution is as shown in FIG. That is, at a position away from the web 12, air-conditioned air flows in a direction opposite to the traveling direction of the web 12, and air accompanied by the traveling web 12 flows in the traveling direction in the vicinity of the web 12. Point a in FIG. 3A is a point where the velocity component becomes zero. This point a moves up and down when the wind speed of the air-conditioning air fluctuates or the speed of the web 12 fluctuates. For example, when the wind speed of the air-conditioning air increases, the point a moves to the vicinity of the web 12. For this reason, the coating liquid on the web 12 flows under the influence of air-conditioning air, and streaks and unevenness occur on the coating surface. Further, since the velocity component is reversed at the point a, a vortex is likely to be generated, thereby causing disturbance on the coating surface. Therefore, in order to perform coating without streaking or unevenness, it is necessary to always remove the influence of the wind above point a.
[0023]
Therefore, in the present embodiment, as shown in FIG. 3B, the wind shielding panel 22 is attached (at a position below the point a). By providing the wind shield panel 22, it is possible to prevent wind from being applied to the application surface of the web 12 from the orthogonal direction, and it is possible to restrict the airflow on the application surface in the traveling direction of the web 12. Therefore, the influence of air-conditioning air that flows in the direction opposite to the traveling direction is eliminated, and the generation of vortex flow can be prevented, so that coating without streaks or unevenness can be performed.
[0024]
By the way, the position of point a in FIG. 3A varies depending on the wind speed of the air-conditioning air, the traveling speed of the web 12, the viscosity of the coating liquid, the coating amount, and the like. For example, FIG. 4 shows a result of measuring the wind speed distribution on the web 12 by performing a down flow with a flow velocity of 0.3 m / s without the wind shield panel 22. As shown in the figure, the wind speed distribution is changed as (1) to (3) by changing the speed of the web 12 to 25 m / min, 50 m / min, and 75 m / min, and the wind speed is zero. The position of the point a changes. Similarly, the position of the point a also changes when the air speed of the air-conditioning air, the viscosity of the coating liquid, or the coating amount is changed. Therefore, it is necessary to move the windshield panel 22 up and down according to the wind speed of the air-conditioning air, the traveling speed of the web 12, the viscosity of the coating liquid, the coating amount, and the like. However, if the distance between the wind shielding panel 22 and the web 12 is too large, a wind speed distribution is generated between the wind shielding panel 22 and the web 12 and a small vortex is formed. On the other hand, if the distance is too short, it is not preferable because it is easily affected by fine unevenness of the windshield panel 22 and fine flutter of the web 12. Therefore, the distance between the wind shielding panel 22 and the web 12 is adjusted to 2 mm or more and 30 mm or less. Thereby, the influence of air-conditioning air can be reliably prevented, and a coated surface free from streaks and unevenness can be obtained.
[0025]
Further, the coating / drying apparatus 10 can further improve the coating accuracy by adjusting the position of the wind shield panel 22 according to the traveling speed of the web 12. For example, when the traveling speed is as fast as 100 m / min, the film pressure of the entrained air accompanying the web 12 becomes thick, so the windshield panel 22 is disposed at a position away from the web 12 by 20 mm or more. On the other hand, when the traveling speed is as low as 20 m / min, the film pressure of the entrained air is thin, so the windshield panel 22 is disposed at a position about 3 mm away from the web 12. Thereby, it can prevent that entrained air disturbs and a coating liquid flows, and can improve a coating precision.
[0026]
As described above, according to the coating and drying apparatus 10 of the present embodiment, since the wind shielding panel 22 is provided above the web 12 between the coating apparatus 14 and the drying apparatus 16, the wind from the direction orthogonal to the coating surface of the web 12. Can be prevented, and the airflow on the coated surface can be restricted in the running direction of the web 12. Thereby, it can prevent that the coating liquid on the web 12 flows with air-conditioning air, and can perform application | coating without a stripe and nonuniformity.
[0027]
In addition, since the coating and drying apparatus 10 adjusts the distance between the wind shielding panel 22 and the web 12 according to the traveling speed of the web 12 and the viscosity of the coating solution, the coating and drying are always free of streaks and unevenness on the web 12. It can be performed. In other words, the distance between the windshield panel 22 and the web 12 is adjusted to an appropriate distance so as to block the influence of the upper air-conditioning air and prevent the wind speed distribution between the web 12 and the windshield panel 22. Application with high accuracy can be performed.
[0028]
Further, since the coating and drying apparatus 10 can move the windshield panel 22 upward, it is advantageous for maintenance.
[0029]
Further, the coating / drying apparatus 10 sets the gap between the coating head 20 and the wind shield panel 22 within 200 mm so that it enters the lower side of the wind shield panel 22 within 0.5 s after the web 12 is coated. It is possible to prevent vibrations from propagating between the panel 22 and the coating head 20, and to minimize the adverse effects of air-conditioned air. If a coating method that does not affect the coating accuracy without using a gap is used, the coating head 20 and the wind shield panel 22 may be connected to completely eliminate the adverse effects of the air-conditioning air.
[0030]
The structure of the wind shield panel 22 is not limited to the above-described embodiment. For example, a frame is made of aluminum pillars, and a PET film having a thickness of 200 μm is pasted on both upper and lower surfaces of the frame. It may be.
[0031]
In addition, a panel with a hole may be used as the wind shield panel 22. For example, a windshield panel with holes in which holes having a diameter of 1 mm are formed in a staggered pattern at intervals of 3 mm on an acrylic panel having a thickness of 3 mm may be used. Such a windshield panel with a hole is effective in the case of a system using a volatile organic solvent as a solvent of a coating solution, particularly a system using a solvent having a high drying speed, and removes a substance evaporated from the coating solution. It can be diffused through the hole. Therefore, it is possible to prevent the occurrence of undesirable problems in terms of explosion prevention, such as the solvent gas on the coating film surface becoming too rich and excessive evaporation being suppressed, or the solvent gas condensing on the lower surface of the panel. Solvents that are effective for using perforated panels include methanol, ethanol, isopropyl alcohol, methyl ethyl ketone, acetone, methyl cellosolve, ethyl cellosolve, diethylene glycol monomethyl ether, 1-methoxy-2-propanol, cyclohexanone, Although there exists methyl cellosolve acetate etc., it is not limited to this. Note that the size, shape, arrangement, and the like of the holes formed in the panel are not limited to the above-described embodiment, and any structure that can diffuse the evaporated substance while obtaining the wind shielding effect may be used.
[0032]
Further, in the above-described embodiment, only the air flow from the upper side of the web 12 is blocked by the wind shielding panel 22, but the present invention is not limited to this, and the air flow from the side or the lower side of the web 12 is blocked. Such a shielding panel may be attached. Further, a tunnel-shaped shielding member may be provided between the coating device 14 and the drying device 16, and the web 12 may pass through the inside of the shielding member.
[0033]
【Example】
A PET film having a thickness of 100 μm and a width of 1.2 m was used as the web 12 and was continuously run at a speed of 60 m / min. As a coating solution, a polymer resin solution having a solvent of MEK / MG = 7: 3, a viscosity of 3CP, and a surface tension of 35 dyne / cm was applied to the web 12 in an amount of 30 cc / m ² . Table 1 shows the results of experiments while changing the distance d between the web 12 and the shielding panel 22.
[0034]
[Table 1]

As can be seen from Table 1, in Comparative Example 2 in which the distance d between the wind shielding panel 22 and the web 12 is larger than 30 mm, the distance d is 30 mm while the application surface has streaks and unevenness. In Example 3, a good coated surface was obtained. In Comparative Example 1 in which the distance d is 1.5 mm, streaks and unevenness are generated, whereas in Example 2 in which the distance d is 3 mm, a good coated surface was obtained.
[0035]
【The invention's effect】
As described above, according to the coating and drying method and apparatus according to the present invention, by providing the air flow regulating means, it is possible to prevent the wind from hitting the coating surface of the support from the orthogonal direction and Since the direction of travel of the support is restricted, it is possible to prevent the coating liquid on the web from flowing under the influence of air such as air-conditioned air, and to obtain a coated surface free from streaks and unevenness.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing a configuration of a coating and drying apparatus according to the present invention. FIG. 2 is a side view showing a feed screw mechanism for supporting a shielding panel. Explanatory diagram showing FIG. 4 Explanatory diagram showing the relationship between web speed and wind velocity distribution [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Application | coating drying apparatus, 12 ... Web, 14 ... Application | coating apparatus, 16 ... Drying apparatus, 18 ... Backup roller, 20 ... Application | coating head, 22 ... Wind shield panel, 24 ... Feed screw mechanism, 26 ... Support | pillar, 28 ... Feed screw , 30 ... piece member

Claims (8)

In a coating and drying method in which a coating solution is applied to a traveling sheet-like or belt-like support and the coating solution is dried.
In at least part of the section from the application of the coating liquid to the start of drying with hot air, the coating surface of the support is covered with a panel, and the distance between the coating surface and the panel is adjusted , panel and the air flow in the running direction of the support between the coated surface, coating and drying process, characterized in that the regulation only in the traveling direction of the component of the support. A coating / drying device that applies a coating solution to a traveling sheet-like or belt-like support with a coating device, and dries the coating solution with a drying device,
A panel is disposed so as to cover at least a part of the coating surface of the support that travels between the coating device and the drying device, and airflow in the travel direction of the support between the panel and the coating surface is supported by the support. and a panel for restricting only the traveling direction of the components of the body, and,
An application / drying apparatus comprising an adjusting means for adjusting a distance between the application surface and the panel.   The coating / drying apparatus according to claim 2, wherein the adjusting unit adjusts the distance between the panel and the coating surface within a range of 2 mm to 30 mm. 4. The coating and drying apparatus according to claim 2, wherein the support is covered with the panel within 0.5 seconds after the coating liquid is applied by the coating apparatus.   The coating and drying apparatus according to any one of claims 2 to 4, wherein the panel has a hole for allowing the evaporated substance of the coating liquid to escape.   2. The distance between the coating surface and the panel is adjusted so that the panel is disposed closer to the coating surface than the point where the air velocity component on the coating surface becomes zero. The coating and drying method described in 1.   The coating and drying method according to claim 1, wherein the coating surface is prevented from being blown from an orthogonal direction.   A step of applying a coating solution to a traveling sheet-like or belt-like support, and a step of drying the applied coating solution by the method of claim 1 or 7, or the device of any one of claims 2 to 5. And a method for producing a support with a dry coating film.

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