JP2003093954A - Drying method and drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of unevenness on a coating film surface when a coating liquid containing an organic solvent is applied onto a web. SOLUTION: The coating liquid containing the organic solvent is applied onto the web 33 transported by a transportation roller 30 with a wire bar 35 of an applicator 34. A drying device 10 is connected with the applicator 34 and air is not mixed in the drying device 10. The drying device 10 is provided with an wind regulating plate 26 confronting the coating film surface of the coating liquid. When the web 33 passes through the drying device 10, gaseous organic solvent evaporated from the coating liquid is uniformly exhausted in a width direction of the web 33 by the wind regulating plate 26. Since thereby the organic solvent uniformly evaporates from the coating film surface of the web 33, the coating liquid is uniformly dried to form a coating film 36 and to suppress occurrence of unevenness on the coating film surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for drying a coating film containing an organic solvent, and more particularly to a method and apparatus for drying a long and wide coating such as a long antiglare antireflection sheet. It is about.

[0002]

2. Description of the Related Art Cathode tube display (CRT), plasma display panel (PDP) and liquid crystal display (LCD).
In such an image display device, an antiglare antireflection sheet is provided in order to prevent a decrease in contrast due to reflection of external light and reflection of an image.

The antiglare antireflection sheet can be obtained by applying a coating solution to a continuously running long support (hereinafter referred to as a web) and drying it to form a coating film. Conventionally, after coating, the web is transported to a drying device by a transport roller. At that time, the surface of the coating film immediately after coating (hereinafter referred to as the coating surface) has an excessive amount of solvent, particularly when a low-boiling organic solvent is used as the solvent of the coating liquid,
Immediately after applying the coating solution, spontaneous evaporation of the solvent occurs.
At this time, a distribution of surface tension is generated on the coating surface due to the film surface temperature distribution on the coating surface, and as a result, the web 9 as shown in FIG.
Broad mottle 91 (hereinafter referred to as "unevenness") was sometimes generated on the coating film surface of 0, and the yield rate was sometimes lowered.

[0004]

Generally, an effective measure against such unevenness occurring in the drying step is to increase the viscosity or increase the viscosity by thickening the coating solution. This is a method in which a viscous agent is added to increase the viscosity of the coating liquid to suppress the flow of the coating film surface immediately after coating due to dry air. By thickening the coating liquid, the viscosity of the coating liquid can be increased, or by adding a thickener, the viscosity of the coating liquid can be increased to suppress the flow of the coating film surface immediately after coating due to the drying air. In this method, the critical coating speed in high-speed ultra-thin layer precision coating has a negative correlation with the viscosity of the coating liquid, so that high-speed coating becomes impossible as the viscosity increases. Therefore, there is a problem that the production efficiency is extremely deteriorated. In addition, Japanese Patent Publication 2-585
It is also known to suppress the occurrence of unevenness due to wind by forming a static gas space region on the web surface as described in Japanese Patent Laid-Open No. 54-54. However, even in this method, since a part of the dry air comes in contact with the surface of the coated film through the mesh (air conditioning member), the air may cause unevenness on the film surface.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a drying method and a drying apparatus capable of uniformly drying without changing the physical properties of the coating liquid.

[0006]

In the drying method of the present invention, a coating solution containing an organic solvent is applied to a continuously transported support, the coating solution is dried, and a coating layer is formed on the support. In the drying method of forming, the plurality of drying zones arranged along the transport direction of the support is an exhaust gas provided with a passage chamber for passing the support and an exhaust pipe by an air conditioning member having a plurality of holes. Of the organic solvent evaporated from the solution applied to the support while the support is sequentially passed through the passage chamber, and the support is conveyed in the passage chamber. Gas is allowed to escape to the exhaust chamber through the hole of the air conditioning member, and the gas of the organic solvent that has entered the exhaust chamber is exhausted to the outside through the exhaust pipe. Further, it is preferable that air is supplied to the exhaust chamber to form an air flow flowing in the exhaust chamber in the width direction of the support. In the present invention, the hole may be referred to as an opening.

According to the drying method of the present invention, a coating solution containing an organic solvent is applied to a continuously running support and dried, and a drying zone is provided immediately after the application of the coating solution.
In the drying zone, the gas of the organic solvent from the coating film surface is exhausted by the air conditioning member arranged so as to face the coating film surface of the coating liquid. A method may also be used in which the gas of the organic solvent from the surface of the coating film is exhausted to the outside of the drying zone through an air-conditioning member arranged in the drying zone so as to face the surface of the coating film of the coating liquid. Further, it is preferable that the gas of the organic solvent is uniformly exhausted in the width direction of the support. Further, the passage chamber has a sealing member arranged so as to surround the support between the air conditioning member, and in the width direction of the support on the opposite side of the support of the air conditioning member. It is preferable to pass dry air. The seal member may be composed of a lid member arranged so as to sandwich the support body with the air conditioning member, and a side seal member connecting the lid member and the air conditioning member. More preferable.

Further, it is preferable that the air conditioning member has a large number of holes, and the gas of the organic solvent is exhausted from the holes. It is preferable that the hole of the air conditioning member is made of wire mesh or punching metal having an opening ratio of 50% or less, and the opening ratio is more preferably 20% to 40%. In the present invention, the opening ratio means a value defined by (opening area / area of opening plate (air conditioning member) × 100 (%)). Furthermore, the gap between the air conditioning member and the coating film surface formed from the coating liquid is preferably 3 mm to 30 mm, more preferably 5 mm to 15 mm.
Is.

It is preferable to have a zone in which the gas of the organic solvent is not exhausted before the coating liquid is dried by the drying zone after coating the coating liquid on the support. Further, it is preferable that the coating liquid is a coating liquid for an antiglare layer, and the antiglare layer is formed from the coating liquid. further,
It is preferable that the coating liquid is a coating liquid for a low refractive index layer, and the coating liquid is coated on the antiglare layer to form a low refractive index layer. The wet film thickness of the layer (film) formed in the present invention is preferably 1 μm to 50 μm, more preferably 1 μm to 20 μm, and most preferably 1 μm to 1 μm.
It is 0 μm. Furthermore, the present invention has a wet film thickness of 1 μm.
It is also possible to apply to thin film formation of less than. Also,
The drying method of the present invention also includes a coating and drying method.

The drying apparatus of the present invention is a drying apparatus which forms a coating layer on the support by drying a solution containing an organic solvent applied to a support which is continuously conveyed, and the drying apparatus is the above-mentioned. It is located downstream of a coating device for applying a solution and includes a plurality of drying zones arranged along the transport direction of the support, and the drying zone includes a passage chamber for passing the support and an exhaust pipe. A main body having an exhaust chamber provided, and a wind regulating member for partitioning the passage chamber and the exhaust chamber are provided, and the wind regulating member is provided on a surface of the support body, which is conveyed in the passage chamber, to which the solution is applied. Faced, a plurality of holes are formed in the air conditioning member, the gas of the organic solvent in the solution applied to the support through the holes flows to the exhaust chamber, from the exhaust pipe of the organic solvent Exhaust gas. In addition, it is preferable to include an intake pipe for supplying air to the exhaust chamber. Further, the intake pipe and the exhaust pipe are provided on the opposite side of the exhaust chamber in the width direction of the support so that the air flows in the exhaust chamber in the width direction of the support. Is preferred. A box-shaped duct that surrounds the support is preferably provided between the drying zone and the coating device.

The drying apparatus of the present invention is a drying apparatus for coating a coating solution containing an organic solvent on a continuously running support and drying the coating solution. A drying zone is provided immediately after the coating of the coating solution, and the drying zone is provided in the drying zone. Is provided with an air conditioning member facing the coating film surface of the coating liquid, and exhausts the gas of the organic solvent evaporated from the coating film surface. Further, it is preferable that the air conditioning member has a large number of holes, and the gas of the organic solvent is exhausted from the holes. The hole of the air conditioning member is preferably made of wire mesh or punching metal having an opening ratio of 50% or less, more preferably 20%.
% To 40%. Furthermore, the gap between the air conditioning member and the coating film surface formed from the solution (coating liquid) is 3 mm to
The air conditioning member is preferably provided with a length of 30 mm, more preferably 5 mm to 15 mm. Further, it is preferable to provide a zone in which the gas of the organic solvent is not exhausted immediately after coating the coating liquid on the support. The drying device of the present invention also includes a coating and drying device.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the drying method and the drying apparatus of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a side view showing an overall configuration of an embodiment of a drying apparatus of the present invention, and FIG. 2 is a top view showing an overall configuration of an embodiment of a drying apparatus of the present invention. Further, FIG. 3 shows a cross-sectional view of a main part of the drying device. In addition, in FIG. 2, the upper lid 25 mentioned later is removed and shown.

As shown in FIG. 1, the drying apparatus 10 of the present invention.
Is used to dry the coating film 36 formed by applying the coating liquid with the wire bar 35 of the coating device 34 onto the web 33 which is supported and transported by the transport rollers 30, 31, 32, and is divided into seven. Drying zones 11, 12, 13,
It is composed of 14, 15, 16, and 17. By sequentially passing through each of these drying zones, a gas of an organic solvent is generated from the coating liquid and a coating film 36 is formed on the web 33. As shown in FIG. 2, each of the drying zones 11 to 11
In one direction of 17, the exhaust ports 18, 19, 20, 21, 21,
It has 2, 23, 24 and is connected to the exhaust device 40.
The exhaust ports 18 to 24 can be individually exhausted by the exhaust device 40. On the other hand, the ventilation ports 41, 42, 43, 44, 45, 46, 47
Is attached and the atmosphere (which may be air or other gas) enters the drying zone. An exhaust pipe and an intake pipe (neither shown) are preferably attached to each exhaust port and each ventilation port.

FIG. 3 shows a sectional view of the drying zone 12 among the seven divided drying zones. The drying zone 12 is
The drying zone main body 12a and the air conditioning plate 26 are provided. The drying zone main body 12a includes a passage chamber 12b for passing the web 33 and an exhaust chamber 12c for exhausting the evaporated solvent gas. Further, the air conditioning plate 26 is provided so as to partition the passage chamber 12b and the exhaust chamber 12c. Exhaust chamber 1
An exhaust pipe 19a and an intake pipe 42a are attached to the 2c, and air (other gas may be used) is sent into the exhaust chamber 12c by the intake pipe 42. The intake pipe 42a and the exhaust pipe 19a are attached to the web 33 on the opposite sides in the width direction, and the web 3
Air flows in the width direction of 3 to form an air flow 12d.
The aperture ratio and material of the air conditioning plate 26 are not particularly limited,
A wire mesh or punching metal having an opening ratio of 50% or less is preferable, and an opening ratio of 20% to 40% is more preferable. Specifically, the opening ratio is 30% at 300 mesh.
The wire mesh of can be used. Further, the air conditioning plate 26 is attached so that the clearance C between the coating film 36 formed on the web 33 and the coating surface 36a is 10 mm. Further, the upper lid 25 and the side seal 4 which are sealing members for suppressing unnecessary air flow from the back surface of the web 33 (the surface where the coating film 36 is not formed) and the side.
8 and 49 are attached. Although a metal wire net is used for adjusting the opening ratio for the air conditioning plate 26, the opening ratio can be determined not only by the metal wire mesh but also by punch metal or the like in the present invention. According to the drying method of the present invention, the gas in which the organic solvent in the coating film 36 is evaporated (usually, the vaporized solvent is contained in high concentration) 36b passes through the hole 26a of the air conditioning plate 26, The air is uniformly exhausted from the exhaust pipe 19a in the width direction of the web by the dry air 12d in the exhaust chamber 12c passing through the air-conditioning plate 26 on the side opposite to the coating surface 36a, and is exhausted to the outside of the drying zone 12. Therefore, the dry air does not come into contact with the coating film surface 36a, and the occurrence of unevenness on the coating film surface 36a is suppressed. The drying zone used in the present invention is not limited to the illustrated form.

Further, as shown in FIG. 1, the drying zone 11
The (hereinafter referred to as the first drying zone) is installed immediately after the coating liquid is applied to the web 33 by the wire bar 35 of the coating device 34, and is installed so that fresh air-conditioned air in the coating chamber does not enter the drying device 10. It is important to.

FIG. 4 is a side view showing the overall construction of a drying apparatus according to another embodiment of the present invention. The drying device 60 shown in FIG. 4 has seven drying zones 61, 62, 6
3, 64, 65, 66, 67, and an upper lid 75a and a side seal 75b, which are sealing members 75, and an air conditioning plate 76 are also attached. Exhaust pipe 6
8, 69, 70, 71, 72, 73 and 74 are also attached to the exhaust ports (not shown) corresponding to the respective zones. The attachment positions of the exhaust pipes 68 to 74 are different from those in the above-described embodiment, and are attached below the respective drying zones. In the present invention, the attachment position of the exhaust pipe attached to the drying zone is not limited to the illustrated form. Further, the drying zone constituting the drying device 10 does not need to be divided into seven as shown in the figure, and it is sufficient that a plurality of drying zones are provided, and the solvent in the coating film is evaporated by these drying zones. The gas can be exhausted uniformly, and the coating film can be uniformly dried. Incidentally, it is particularly preferable that the drying zone is composed of 2 to 10 drying zones.

Next, the coating apparatus 10 configured as described above.
The action of will be explained. After the coating liquid is applied to the web 33 supported and conveyed by the conveying rollers 30, 31, 32 by the wire bar 35 of the coating device 34, the initial state is set by the drying device 10 according to the present invention provided immediately after the coating device 34. A drying operation is performed. The coating surface immediately after coating is in a solvent excess state, and especially in the initial drying immediately after coating the coating solution using an organic solvent, the distribution of the surface temperature changes from the distribution of the film surface temperature due to the distribution (fluctuation) of evaporation of the solvent. Occurs, and as a result,
Fluidization occurs in the surface of the coating film, and the coating film in the portion that is slow to dry becomes thin and uneven. Therefore, during the initial period of drying from the time of application until the flow on the coating surface stops, random airflow from the outside is blocked, and the solvent concentration near the coating surface is always kept constant and evaporates. It is necessary to eliminate the solvent gas uniformly.

Therefore, after the coating liquid is applied to the web 33 by the wire bar 35 of the coating device 34, the coated web 33 is surrounded immediately after the coating device 34 as shown in FIG. Suppresses intrusion and has an aperture ratio of 30% 3
A drying device 10 to which a wire mesh of 00 mesh is attached is provided, and each of the seven drying zones 11, 12, 1 is provided.
The solvent concentration in the vicinity of the coating film surface was always kept constant by enabling uniform exhaust in the width direction at 3, 14, 15, 16, and 17. Further, if the gap between the coating surface 36a and the air conditioning plate 26 is wide, air vortices are generated, which causes unevenness on the coating surface 36a. Therefore, in order to control the flow of wind, the clearance C between the coating film surface 36a and the air conditioning plate 26 is set to 3
The thickness is preferably 30 mm to 30 mm, more preferably 5 mm to 15 mm. Further, by controlling the exhaust speed from the exhaust ports respectively attached to the seven divided drying zones by the exhaust device 40, the exhaust accuracy is improved and the flow of the wind containing the solvent flowing on the coating film surface is improved. Thus, it is possible to suppress the occurrence of unevenness on the coating film surface.

Most preferably, the gas of the evaporated organic solvent is not exhausted in the first drying zone 11. Therefore, in the first drying zone 11, the exhaust pipe may be attached to the exhaust port 18 and the intake pipe may be attached to the ventilation port 41 without being connected to the exhaust device 40. Also, the exhaust port 11 and the ventilation port 4
The respective mouths may be left open without attaching pipes to 1 and. However, in the first drying zone 11 used in the present invention, the exhaust port 18 and the ventilation port 41 are provided so that the gas (mainly air) outside the drying device 10 is not mixed.
Most preferably, it is a box-shaped duct without the provision of and.
Further, when exhausting, it is necessary to exhaust at a speed equal to or lower than the exhaust speed of the other drying zones in order to suppress the occurrence of unevenness of the coating film surface. In the present invention, the first
The form of the drying zone 11 is not limited to the box-shaped duct described above.

[Web] Generally, the web used in the present invention has a width of 0.3 m to 5 m and a length of 45 m to 1000.
0 m, thickness 5 μm to 200 μm polyethylene terephthalate, polyethylene-2,6 naphthalate, cellulose diacetate, cellulose triacetate (triacetyl cellulose), cellulose acetate propionate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyimide, polyamide, etc. Such as plastic film. Further, papers and papers coated with or laminated with α-polyolefins having 2 to 10 carbon atoms such as polyethylene, polypropylene, and ethylene butene copolymers can also be used. In addition, aluminum,
A metal foil such as copper or tin may also be used. Then, those obtained by forming a preliminary processing layer on the surface of these webs may be used. Further, the web is coated with an optical compensatory sheet coating liquid, a magnetic coating liquid, a photographic photosensitive coating liquid, a surface protection, antistatic or lubricity coating liquid, etc. on its surface, and after drying, the desired length and Those which are cut into widths are also included, and typical examples of these include optical compensation sheets, various photographic films, photographic papers, magnetic tapes and the like.

[Coating Liquid] As the coating liquid (solution) which can be used in the present invention, any known coating liquid can be used as long as it forms a coating film on a web. However, in the present invention, it is preferable to use a coating liquid that forms an antiglare layer. The wet film thickness of the coating film of the present invention is preferably 1 μm to 50 μm, more preferably 1 μm to 20 μm, and most preferably 1 μm.
10 to 10 μm. Furthermore, the present invention has a wet film thickness of 1
It can also be applied to the formation of a thin film having a thickness of less than μm.

[Coating Method] Examples of the coating method of the above coating solution include bar coating, curtain coating, extrusion coating, roll coating, dip coating, spin coating, gravure coating, micro gravure coating, spray coating and slide coating. You can Particularly, bar coating, extrusion coating, gravure coating and microgravure coating are preferable.

In the present invention, the number of coating layers of the coating solution coated simultaneously is not limited to a single layer, but can be applied to a simultaneous multilayer coating method as required.

FIG. 5 shows a production line of an antiglare antireflection sheet constituted by using the drying device 10 of the present invention. The web 33 is delivered from the delivery device 80, and while being supported by the transport rollers 81, the dust remover 82 removes dust adhering to the surface of the web 33. Then, after the coating liquid for forming the antiglare layer is applied by the coating device 34, initial drying is performed by the drying device 10. After that, while being further supported by the conveyance roller 81, the web 3
3 passes through the dryer 83 and the heater 84 to form an antiglare layer. Further, the ultraviolet ray lamp 85 is applied to the antiglare layer formed on the surface of the web 33 to form a desired polymer. The web 33 having the polymer formed thereon is taken up by the winder 8
Take up by 6. Furthermore, it is possible to form a low refractive index layer on the web on which the antiglare layer is formed. The web on which the antiglare layer was formed was again attached to the delivery device 80, and the coating liquid for the low refractive index layer was applied by the coating device and the drying device and dried to form the low refractive index layer on the antiglare layer. ,
An antiglare antireflection sheet can be obtained. The low refractive index layer may be a single layer or a plurality of layers. Further, the drying apparatus and the drying method according to the present invention are shown in FIG.
In addition to the manufacturing line shown in (1), it can be applied to, for example, an alignment film manufacturing line.

[0025]

EXAMPLES Examples will be given below, but the present invention is not limited thereto. As examples, Experiment 1 in which the opening ratio of the wire mesh was changed (Examples 1 to 4 and Comparative Example 1) and Experiment 2 in which the clearance between the wire mesh and the coating surface and the wire mesh was changed (Examples 5 to 8 and Comparative Example 2) Experiment 3 in which the exhaust speed of the first drying zone was changed (Examples 9 and 10 and Comparative Example 3) and Experiment 4 in which an antiglare antireflection sheet was prepared (Example 11)
Respectively. The experimental conditions were described in detail in Example 1, and the same conditions were omitted in the other Examples and Comparative Examples.

[Experiment 1] (Example 1) The web 33 had a thickness of 80 μm of triacetyl cellulose (Fujitac, Fuji Photo Film Co., Ltd.).
Manufactured by JSR Co., Ltd., and an ultraviolet curable hard coat composition (Desolite Z-7526, 72% by weight, JSR
(Manufactured by K.K.) 250 g was dissolved in 62 g of methyl ethyl ketone and 88 g of cyclohexane to prepare a liquid.
After applying 8.6 ml of the liquid per 1 m ² of web,
The coating layer was dried at 120 ° C. for 5 minutes and irradiated with ultraviolet rays using an air-cooled metal halide lamp of 160 W / cm (manufactured by Eye Graphics Co., Ltd.) to cure the coating layer to a thickness of 25.
A hard coat layer having a thickness of μm was formed.

On the above-mentioned hard coat layer, as a coating liquid, 91 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), a hard coat containing a zirconium oxide dispersion. Coating liquid (Desolite Z
-21 g of −7401 manufactured by JSR Corporation was dissolved in a mixed solvent of 52 g of methyl ethyl ketone / cyclohexanone = 54/46 wt%. 10 g of a photopolymerization initiator (Irgacure 907, manufactured by (Ciba Geigy)) was added to the obtained solution.
Was added to prepare a coating solution. While the web was running at a running speed of 10 m / min using the apparatus shown in FIG. 1, this coating solution was applied from the coating apparatus 34 onto the hard coat layer so that the coating solution amount was 4.2 ml per 1 m ^{2 of the} web. Was applied with a wire bar 35.

Immediately after coating, initial drying was performed using the drying device 10 of the present invention shown in FIG. The drying device 10 has an opening ratio of the air conditioning plate 26 of 25%, a distance between the coating film surface and the air conditioning plate of 10 mm, and an exhaust air velocity of each drying zone is 0.1 m /
Set to seconds. The web 33 initially dried by the drying device 10 of the present invention is passed through the dryer 83 and the heater 84, which are adjusted to 100 ° C. by the production line shown in FIG. 5, to further dry the coating liquid, and then the ultraviolet lamp. Ultraviolet rays were irradiated by 85 and wound by a winding machine 86.

The occurrence of unevenness on the surface of the wound web was visually observed. Regarding the occurrence of unevenness in Tables 1 to 3 shown below, ◎ means that no unevenness occurs at all, ○ means that very weak unevenness occurs, but it does not pose any problem as a product, and Δ means unevenness occurs. Was observed, but it was not a problem depending on the type of product, and × was not possible to use as a product due to many unevenness. In addition, in Experiment 1, the evaluation of drying unevenness was also performed. Evaluation is ○
The evaluation was carried out on the basis of a three-level evaluation, that is, there is no unevenness in drying, Δ is that there is some unevenness in drying but it does not pose a problem as a product, and x is that there is severe unevenness in drying and the product cannot be used. The evaluation results are shown in Table 1.

(Examples 2 to 4) The experiments of Examples 2 to 4 were carried out by changing the aperture ratio of the air conditioning plate to 30%, 35% and 50%. The experimental conditions were the same as in Example 1 except that the aperture ratio of the air rectifying plate was changed, and the evaluation was performed under the same conditions. The results are summarized in Table 1.

(Comparative Example 1) In Comparative Example 1, the aperture ratio is 75%.
An experiment was conducted under the same conditions as in Example 1 except that the air conditioning plate of No. 1 was used, and the results were evaluated. The results are shown in Table 1.

[0032]

[Table 1]

From Table 1, it was found that when an air conditioner with an aperture ratio of 50% or less was used, neither unevenness nor drying unevenness occurred at all.

[Experiment 2] In Experiment 2, the opening ratio of the air conditioning plate was 30% and the exhaust air velocity in each drying zone was 0.1 m / sec.
An experiment was performed in which the gap C between the coating film surface and the air conditioning plate was changed. The gaps C were set to 3 mm, 10 mm, 20 mm, and 30 mm, and the experiments of Examples 5 to 8 were conducted and evaluated. The evaluation results are summarized in Table 2. In addition, if the gap C was set to 3 mm or less, the coating film surface contacted the surface of the air rectifying plate, and it was impossible to continue the experiment. Further, an experiment in which the gap C was 50 mm was conducted as Comparative Example 2 and evaluated, and the results are shown in Table 2.

[0035]

[Table 2]

From Table 2, the gap C between the paint film surface and the air conditioning plate is 3 m.
It was found that the problem of unevenness did not occur in the range of m to 30 mm.

[Experiment 3] In Experiment 3, the first drying zone 1 was used.
An experiment was conducted in which the exhaust air velocity in the drying zones other than 1 was fixed at 0.1 m / sec and the exhaust air velocity in the first drying zone was examined. The gap C between the coating film surface and the air conditioning plate was fixed at 10 mm, and the aperture ratio of the air conditioning plate was fixed at 30%. The experiment was performed and evaluated as Example 10 and Example 11 and Comparative Example 3 with the exhaust air velocity in the first drying zone set to 0 m / sec, 0.1 m / sec and 0.2 m / sec. The results are summarized in Table 3.

[0038]

[Table 3]

From Table 3, it was found that unevenness did not occur when the exhaust was not performed in the first drying zone. Also, the first
If the exhaust air velocity in the drying zone is faster than in other drying zones,
It was also found that unevenness would occur.

[Experiment 4] In Example 11, an antiglare antireflection sheet was produced using the production line shown in FIG.
The web 33 has a thickness of 80μ consisting of three layers by co-casting.
m of triacetyl cellulose film was used. No clear interface was observed in this film.

(Preparation of Coating Solution for Antiglare Layer) The coating solution for the antiglare layer is a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (D
PHA, Nippon Kayaku Co., Ltd.) 75 g, zirconium oxide ultrafine particle dispersion-containing hard coat coating solution (Desolite Z-7401, JSR Co., Ltd.) 240
g was dissolved in 52 g of a mixed solvent of methyl ethyl ketone / cyclohexanone = 54/46% by weight. To the obtained solution, 10 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Fine Chemicals Co., Ltd.) was added, dissolved with stirring, and then a fluorosurfactant (Megafuck F made of a solution of 20 wt% fluorine-containing oligomer in methyl ethyl ketone) was added. −
176PF, 0.93 g of Dainippon Ink and Chemicals, Inc. was added. (Note that the coating film obtained by coating this solution and curing it with ultraviolet light had a refractive index of 1.65.) Further, this solution had a number average particle diameter of 2.0 μm and a crosslinked polystyrene having a refractive index of 1.61. 20 g of particles (SX-200HS, manufactured by Soken Chemical Industry Co., Ltd.) were dispersed in 80 g of a mixed solvent of methyl ethyl ketone / cyclohexanone = 54/46% by weight with a high speed disperser at 5000 rpm for 1 hour with stirring to obtain a pore size of 1
0 μm, 3 μm, 1 μm polypropylene filters (PPE-10, PPE-03, PPE-0, respectively)
1. All were added with 29 g of the dispersion obtained by filtering with Fuji Photo Film Co., Ltd., and after stirring, the pore size was 30 μm.
m polypropylene filter to prepare an antiglare layer coating solution.

(Preparation of Coating Liquid for Low Refractive Index Layer) Refractive Index is 1.42 and 6% by Weight of Thermally Crosslinkable Fluorine-Containing Polymer
Methyl ethyl ketone solution (JN-7228, JSR
MEK-ST (average particle size 10 nm) in 93 g
˜20 nm, 8 g of methyl ethyl ketone dispersion of SiO ₂ sol having a solid content of 30% by weight, Nissan Chemical Co., Ltd., 94 g of methyl ethyl ketone and 6 g of cyclohexanone were added, and after stirring, a polypropylene filter (PPE-01) having a pore size of 1 μm And filtered to prepare a coating liquid for low refractive index layer.

The above-mentioned antiglare layer coating solution was applied onto the above-mentioned web 33 using a bar coater and dried at 120 ° C., and then a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) was used. Illuminance 400
It was irradiated with ultraviolet rays of mW / cm ² and an irradiation amount of 300 mJ / cm ² to be cured to form an antiglare layer having a thickness of 1.5 μm.
The coating liquid for a low refractive index layer described above is coated thereon using a bar coater, dried at 80 ° C., and then at 120 ° C. for 8 hours.
After heat-crosslinking for minutes, a low-refractive index layer having a thickness of 0.096 μm was formed to obtain an antiglare antireflection sheet. This anti-glare anti-reflection sheet is used for louver-free exposed fluorescent lamp (8000 cd
/ M ² ) was observed and the degree of blurring of the reflected image was observed, and it was found that the outline of the fluorescent lamp was completely unknown and an optical property excellent in optical characteristics was obtained.

[0044]

According to the coating film drying method and the drying apparatus of the present invention, a coating solution containing an organic solvent is applied to a continuously transported support, the coating solution is dried, and the support is dried. In the drying method for forming a coating layer on the substrate, a plurality of drying zones arranged along the transport direction of the support is provided with a passage chamber for passing the support and an exhaust pipe by an air conditioning member having a plurality of holes. It is separated into an exhaust chamber equipped with
The organic solvent gas evaporated from the solution applied to the support is passed through the holes of the air conditioning member while the support is sequentially passed through the passage chamber and the support is transported in the passage chamber. Since the gas of the organic solvent that has flowed through the exhaust chamber to the exhaust chamber is exhausted to the outside through the exhaust pipe, the occurrence of unevenness on the surface of the coating film is suppressed.

Furthermore, by providing a box-shaped duct that surrounds the support between the drying zone and the coating device, the occurrence of unevenness can be further suppressed.

[Brief description of drawings]

FIG. 1 is a schematic side view of a drying device according to the present invention.

FIG. 2 is a top view of the drying device according to the present invention.

FIG. 3 is a cross-sectional view of a main part of a drying device according to the present invention.

FIG. 4 is a schematic side view of a drying device according to another embodiment of the present invention.

FIG. 5 is a view showing a production line for forming a coating film on a web by using the drying device of the present invention.

FIG. 6 is a diagram for explaining unevenness generated on a coating film surface of a web.

[Explanation of symbols]

10 Drying device 11 First drying zone 12,13,14,15,16,17 Drying zone 12a Drying zone body 12b passage room 12c exhaust chamber 12d dry wind 19a exhaust pipe 25 Top cover 26 Air conditioning board 33 Web 34 coating device 36 coating film 36a coating surface 36b gas 40 exhaust system 42a intake pipe

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomonari Ogawa             200, Onakazato, Fujinomiya City, Shizuoka Prefecture Fuji Photo             Within Film Co., Ltd. (72) Inventor Toshio Shibata             Fuji Photo, 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture             Within Film Co., Ltd. (72) Inventor Takashi Nawano             Fuji Photo, 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture             Within Film Co., Ltd. F term (reference) 3L113 AA02 AB02 AC31 AC67 AC73                       BA32 DA24                 4D075 BB24Z BB93Z CA47 DA04                       DB18 DB33 DB36 DB38 DB48                       DB53 DC24 EA07 EA21 EB22                 4F042 AA22 AB00 BA13 BA16 BA18                       DB02 DB25 DB29 DB30 DB36                       DB37

Claims (15)

[Claims] 1. A drying method of applying a coating liquid containing an organic solvent to a continuously transported support, drying the coating liquid to form a coating layer on the support, wherein the transport of the support is performed. The plurality of drying zones arranged along the direction are separated into a passage chamber for passing the support body and an exhaust chamber provided with an exhaust pipe by an air conditioning member having a plurality of holes. Through the passage chamber, while the support is transported in the passage chamber, the gas of the organic solvent evaporated from the solution applied to the support is passed through the hole of the air conditioning member. A drying method, characterized in that the gas of the organic solvent that has flowed into the exhaust chamber is exhausted to the outside through an exhaust pipe. 2. The drying method according to claim 1, wherein air is supplied to the exhaust chamber to form an air flow flowing in the exhaust chamber in the width direction of the support. 3. The drying method according to claim 1, wherein the gas of the organic solvent is uniformly exhausted in the width direction of the support. 4. The passage chamber has a seal member arranged so as to surround the support body with the air regulating member, and the sealing member is provided on a surface of the air regulating member opposite to the support body. The dry air is allowed to pass in the width direction.
To 3 any one of the drying methods. 5. The drying method according to claim 1, wherein the air-conditioning member is made of wire mesh or punching metal having an opening ratio of 50% or less. 6. The drying method according to claim 1, wherein a gap between the air conditioning member and a coating film surface formed from the coating liquid is 3 mm to 30 mm. 7. The method according to claim 1, further comprising a zone in which the gas of the organic solvent is not exhausted before the coating liquid is dried by the drying zone after the coating liquid is coated on the support. Any one of the drying methods. 8. The coating solution is an antiglare layer coating solution,
The drying method according to claim 1, wherein an antiglare layer is formed from the coating solution. 9. The low refractive index layer coating liquid according to claim 8, wherein the low refractive index layer is formed by coating the coating liquid on the antiglare layer. Drying method. 10. A drying device for drying a solution containing an organic solvent applied to a continuously transported support to form a coating layer on the support, wherein the drying device applies the solution. A plurality of drying zones located downstream of the device and arranged along the transport direction of the support, the drying zone including a passage chamber for passing the support;
A main body having an exhaust chamber provided with an exhaust pipe, and an air regulating member for partitioning the passage chamber and the exhaust chamber are provided, and the air regulating member is applied with a solution on a support conveyed in the passage chamber. Facing each other, a plurality of holes are formed in the air conditioning member, the gas of the organic solvent in the solution applied to the support flows through the holes to the exhaust chamber, and the exhaust pipe from the exhaust pipe. A drying device, which discharges a gas of an organic solvent from an exhaust chamber. 11. The drying apparatus according to claim 10, further comprising an intake pipe that supplies air to the exhaust chamber. 12. The intake pipe and the exhaust pipe are provided on the opposite side of the exhaust chamber in the width direction of the support so that the air flows in the exhaust chamber in the width direction of the support. The drying device according to claim 11, wherein 13. The drying device according to claim 10, further comprising a box-shaped duct surrounding the support between the drying zone and the coating device. 14. The drying device according to claim 10, wherein the air-conditioning member is made of wire mesh or punching metal having an opening ratio of 50% or less. 15. The air-conditioning member is provided with a gap between the air-conditioning member and a coating film surface formed from the solution being set to 3 mm to 30 mm. The drying device described.