KR20120113180A - Drying apparatus method for drying film and solution film forming method - Google Patents

Abstract

PURPOSE: A drying apparatus, a drying method of a membrane, and a solution forming method are provided to efficiently form a film with a flat surface by preventing the malfunction of a flexible membrane. CONSTITUTION: A drying apparatus dries a membrane formed on a mobile support. The drying apparatus includes a cover, a first air supplying hole, a first drying unit(51), a second air supplying hole, a second drying unit(52), and a controlling part. The cover covers the membrane. The first drying unit includes the cover and the first air supplying hole which supplies first drying wind(61). The second drying unit includes the second air supplying hole which supplies second drying wind(75). The controlling part controls either the wind speed of the first drying wind or the second drying wind.

Description

Drying apparatus, drying method of film and solution film forming method {DRYING APPARATUS, METHOD FOR DRYING FILM AND SOLUTION FILM FORMING METHOD}

The present invention relates to a drying apparatus, a drying method of a film, and a solution film forming method.

Since the polymer film (henceforth a film) which has a light transmittance is light weight and it is easy to shape | mold, it is used for various surfaces as an optical film. Especially, the cellulose-ester type film using cellulose acylate etc. is used for the optical film which is a structural member of the liquid crystal display device which the market expanded recently, including the film for photographic photosensitization. As such an optical film, there exists a retardation film, a polarizing plate protective film, etc., for example.

Such a film is manufactured by the solution film forming method. The outline of the solution film forming method is as follows. First, the polymer solution (henceforth dope) containing a polymer and a solvent is flowed out, and a cast film is formed on a moving support body. Second, the solvent is evaporated from the flexible membrane until the flexible membrane becomes self-supporting and can be conveyed. Third, the cast film is peeled off from the moving support to form a wet film. Thereafter, the film can be obtained from the wet film by evaporating the solvent from the wet film.

In order to improve the production efficiency in the solution film forming method, it is necessary to efficiently evaporate the solvent in the cast film. For this purpose, it is necessary to blow a vertical drying wind with respect to a flexible film (henceforth a dry processing). However, when vertical drying wind is applied to the flexible membrane immediately after formation, wrinkles will appear on the surface of the flexible membrane. Even if the flexible film in which such wrinkles were formed is peeled from a support body as it is, wrinkles remain in the film finally obtained.

Therefore, the method of drying a casting film efficiently, preventing the formation of wrinkles, for example, is proposed by Unexamined-Japanese-Patent No. 2007-290375. In the drying method of Unexamined-Japanese-Patent No. 2007-290375, in the flexible membrane immediately after formation, a drying duct is provided so that the surface of a flexible membrane may be covered, and it becomes the back wind to a flexible membrane toward the clearance gap between a drying duct and a flexible membrane. The drying wind is sent (hereinafter, referred to as pre-drying treatment). By carrying out this pre-drying process for a certain time, the dry layer with the smooth surface can be formed in the surface side of a casting film. And a film with a smooth surface can be manufactured efficiently by performing pre-drying process and this drying process one by one.

In the drying method of Unexamined-Japanese-Patent No. 2007-290375, in order to further improve production efficiency, the moving speed of a moving support should be increased. However, when the moving speed of the moving support is increased, the length of the zone to be subjected to the pre-drying process (hereinafter, referred to as the pre-drying zone) must be increased in order to secure the production time of the dried layer. Therefore, by increasing the moving speed of the moving support and increasing the wind speed of the pre-drying wind, it is possible to ensure both the creation time of the dry layer and the avoidance of the enlargement of the pre-drying zone.

By the way, when the wind speed of the pre-drying wind was increased, when the flexible film was to be peeled from the support, a part of the flexible film remained on the support, or a failure occurred such that the peeled flexible film was torn.

As a result of the earnest review of the inventors, it was found that the above problem is caused by a decrease in the drying efficiency in the present drying treatment. The present invention solves these problems, and provides a drying apparatus for efficiently drying the flexible membrane while smoothing the surface of the flexible membrane, a method for drying the membrane, and a solution film formation method capable of efficiently producing a film with a smooth surface. For the purpose of

The drying apparatus of this invention is a drying apparatus which dries the film | membrane formed on the moving support body. The membrane includes a polymer and a solvent. The drying apparatus includes a cover, a first air supply port, a first drying unit, a second air supply unit, a second drying unit, and a control unit. The cover covers the membrane. The first air supply unit sends the first drying wind. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. The said 1st drying unit has the said cover and a 1st air supply port. The first drying unit sends the first drying wind from the first air supply port until a dry layer is formed on the surface side of the film by evaporation of the solvent. The second air supply port sends the second drying wind. The said 2nd air supply port is provided in the downstream of the moving direction of the said moving support body rather than the said cover. The second air supply port sends the second drying wind that is approximately vertical toward the surface of the film. The second drying unit has the second air supply port. The second drying unit accelerates the evaporation of the solvent by impinging the second drying wind on the surface of the film. The said control part controls at least one of the wind speed V1 of a said 1st dry wind, and the wind speed V2 of a said 2nd dry wind. The control unit controls at least one of the wind speed V1 and the wind speed V2 so that the collision of the second dry wind to the surface of the film is maintained.

It is preferable that the value of V1 / V2 is 0.6 or less.

It is preferable that the said drying apparatus is equipped with the exhaust part which exhausts the said 1st drying wind. The exhaust part is provided between the cover and the second air supply port.

The drying apparatus of this invention is a drying apparatus which dries the film | membrane formed on the moving support body. The membrane includes a polymer and a solvent. The drying apparatus includes a cover, a first air supply port, a first drying unit, a second air supply unit, a second drying unit, and an exhaust unit. The cover covers the membrane. The first air supply unit sends the first drying wind. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. The first drying unit includes the cover and the first air supply port. The first drying unit sends the first drying wind from the first air supply port until a dry layer is formed on the surface side of the film by evaporation of the solvent. The second air supply port sends the second drying wind. The said 2nd air supply port is provided in the downstream of the moving direction of the said moving support body rather than the said cover. The second air supply port sends the second drying wind that is approximately vertical toward the surface of the film. The second drying unit has the second air supply port. The second drying unit accelerates the evaporation of the solvent by impinging the second drying wind on the surface of the film. The exhaust unit exhausts the first drying wind. The exhaust part is provided between the cover and the second air supply port.

It is preferable that this drying apparatus is provided with the windshield which interrupt | blocks the said 1st drying wind which flows from the said 1st air supply port toward the said 2nd air supply port.

The drying apparatus of this invention is a drying apparatus which dries the film | membrane formed on the moving support body. The membrane includes a polymer and a solvent. The drying apparatus includes a cover, a first air supply unit, a first drying unit, a second air supply unit, a second drying unit, and a windshield. The cover covers the membrane. The first air supply unit sends the first drying wind. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. The first drying unit includes the cover and the first air supply port. The first drying unit sends the first drying wind from the first air supply port until a dry layer is formed on the surface side of the film by evaporation of the solvent. The second air supply port sends the second drying wind. The said 2nd air supply port is provided in the downstream of the moving direction of the said moving support body rather than the said cover. The second air supply port sends the second drying wind that is approximately vertical toward the surface of the film. The second drying unit has the second air supply port. The second drying unit accelerates the evaporation of the solvent by impinging the second drying wind on the surface of the film. The windshield blocks the first drying wind flowing from the first air supply port toward the second air supply port. The windshield is provided between the cover and the second air supply.

The drying method of the membrane of the present invention is a drying method of the membrane for drying the membrane formed on the moving support. The membrane includes a polymer and a solvent. The drying method of the film includes a first drying step, a second drying step, and a control step. In the first drying step, the first drying air is sent from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent. The first drying unit has a cover and the first air supply port. The cover covers the membrane. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. The second drying step promotes evaporation of the solvent by impinging the second drying wind from the second drying unit on the surface of the membrane. The second drying unit has a second air supply port. The second air supply port sends the second dry wind that is approximately vertical toward the surface of the film. The second air supply port sends the second drying air downstream from the cover in the moving direction of the moving support. The control step controls at least one of the wind speed V1 of the first dry wind and the wind speed V2 of the second dry wind. At least one of the wind speed V1 and the wind speed V2 is controlled to maintain the collision of the second dry wind on the surface of the film.

The drying method of the membrane of the present invention is a drying method of the membrane for drying the membrane formed on the moving support. The membrane contains a polymer and a solvent. The drying method of the film includes a first drying step (step A), a second drying step (step B), and an evacuation step (step C). In the step A, the first drying air is sent out from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent. The first drying unit has a cover and the first air supply port. The cover covers the membrane. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. The step B promotes evaporation of the solvent by impinging the second drying wind from the second drying unit on the surface of the membrane. The second drying unit has a second air supply. The second air supply port sends the second dry wind that is approximately vertical toward the surface of the film. The second air supply port sends the second drying air downstream from the cover in the moving direction of the moving support. In step C, the first drying wind is exhausted. The evacuation is performed between the A step and the B step.

The drying method of the membrane of the present invention is a drying method of the membrane for drying the membrane formed on the moving support. The membrane includes a polymer and a solvent. The drying method of the film includes a first drying step (step D), a second drying step (step E), and a wind-winding step (step F). In the step D, the first drying air is sent out from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent. The first drying unit has a cover and the first air supply port. The cover covers the membrane. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. In step E, the evaporation of the solvent is promoted by impinging the second drying air from the second drying unit on the surface of the film. The second drying unit has a second air supply. The second air supply port sends the second dry wind that is approximately vertical toward the surface of the film. The second air supply port sends the second drying air downstream from the cover in the moving direction of the moving support. The step F blocks the first drying wind flowing toward the second air supply port between the step D and the E step.

The solution film forming method of the present invention is a solution film forming method for drying a film formed on a moving support to produce a film. The membrane includes a polymer and a solvent. The solution film forming method includes a first drying step (G step), a second drying step (H step), a control step (I step), and a peeling step (J step). In step G, the first drying air is sent out from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent. The first drying unit has a cover and the first air supply port. The cover covers the membrane. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. The H step accelerates the evaporation of the solvent by impinging the second drying wind from the second drying unit on the surface of the membrane. The second drying unit has a second air supply port. The second air supply port sends the second dry wind that is approximately vertical toward the surface of the film. The second air supply port sends the second drying air downstream from the cover in the moving direction of the moving support. In step I, at least one of the wind speed V1 of the first dry wind and the wind speed V2 of the second dry wind is controlled. At least one of the wind speed V1 and the wind speed V2 is controlled to maintain the collision of the second dry wind on the surface of the film. In the step J, the film after the step H is peeled from the moving support to form a film.

The solution film forming method of the present invention is a solution film forming method for drying a film formed on a moving support to produce a film. The membrane includes a polymer and a solvent. The solution forming method includes a first drying step (step A), a second drying step (step B), an evacuation step (step C), and a peeling step (step K). In the step A, the first drying air is sent out from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent. The first drying unit has a cover and the first air supply port. The cover covers the membrane. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. The step B promotes evaporation of the solvent by impinging the second drying wind from the second drying unit on the surface of the membrane. The second drying unit has a second air supply port. The second air supply port sends the second dry wind that is approximately vertical toward the surface of the film. The second air supply port sends the second drying air downstream from the cover in the moving direction of the moving support. In step C, the first drying wind is exhausted. The evacuation is performed between the A step and the B step. In the step K, the film after the step B is peeled from the moving support to form a film.

The solution film forming method of the present invention is a solution film forming method for drying a film formed on a moving support to produce a film. The membrane includes a polymer and a solvent. The solution forming method includes a first drying step (step D), a second drying step (step E), a wind-winding step (step F), and a peeling step (step L). In the step D, the first drying air is sent out from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent. The first drying unit has a cover and the first air supply port. The cover covers the membrane. The said 1st air supply port is provided in the upstream of the moving direction of the said moving support body rather than the said cover. The first air supply port sends the first drying wind toward the cover and the membrane. In step E, the evaporation of the solvent is promoted by impinging the second drying air from the second drying unit on the surface of the film. The second drying unit has a second air supply port. The second air supply port sends the second dry wind that is approximately vertical toward the surface of the film. The second air supply port sends the second drying air downstream from the cover in the moving direction of the moving support. In step F, the first drying wind flowing toward the second air supply port is blocked. The F step is performed between the D step and the E step. In step L, the film after step E is peeled from the moving support to form a film.

According to the present invention, the first drying wind can be prevented from flowing in between the second air supply port for sending the second drying wind toward the flexible membrane and the flexible membrane, so that the flexible membrane can be dried efficiently. Therefore, according to this invention, the film with a smooth surface can be manufactured efficiently, preventing the malfunction resulting from the drying lack of a casting film.

The above objects and advantages will be readily understood by those skilled in the art by reading the detailed description of the preferred embodiments with reference to the accompanying drawings.
1 is an explanatory diagram showing an outline of a solution film forming facility.
2 is an explanatory diagram showing an outline of the flexible apparatus.
3 is a perspective view showing an outline of a first drying unit and a second drying unit.
4 is an explanatory diagram showing an outline of a first drying unit and a second drying unit.
FIG. 5: is sectional drawing along the VV line of FIG. 4 which shows the outline | summary of a 1st drying unit. FIG.
FIG. 6: is sectional drawing along the VI-VI line of FIG. 4 which shows the outline | summary of a 1st drying unit. FIG.
FIG. 7: is a perspective view which shows the outline | summary of a 2nd air supply duct and a 2nd air supply nozzle. FIG.
8 is a side view showing an outline of a second drying unit.
9 is a cross-sectional view showing an outline of a flexible film immediately after formation.
10 is a cross-sectional view showing an outline of a flexible film having a dry layer.
FIG. 11: is explanatory drawing which showed typically the state in which 2nd dry wind is extruded by 1st dry wind. FIG.
FIG. 12: is explanatory drawing which shows the outline | summary of a 1st drying unit and a 2nd drying unit. FIG.

(Solution forming equipment)

EMBODIMENT OF THE INVENTION 1st Embodiment is described regarding this invention. As shown in FIG. 1, the solution film forming facility 10 includes a casting device 15, a clip tenter 17, a drying device 18, and a winding device 19. The casting apparatus 15 makes the wet film 13 with the dope 12. The clip tenter 17 obtains the film 16 by drying the wet film 13. The drying apparatus 18 performs drying of the wet film 13. The winding apparatus 19 winds up the film 16 to a winding core.

(Flexible device)

As shown in FIG. 1 and FIG. 2, the flexible device 15 has a casing 23 and horizontal rolls 24 and 25 arranged substantially horizontally in the casing 23. The horizontal roll 24 consists of a drive shaft 24a and the roll main body 24b axially attached to the drive shaft 24a. The horizontal roll 25 consists of the shaft 25a and the roll main body 25b attached to the shaft 25a. An annular flexible band 26 is wound around the horizontal rolls 24 and 25. The flexible band 26 can be obtained by connecting both ends of a strip | belt-shaped sheet | seat.

The drive shaft 24a is connected to a roll driving motor (not shown). A control unit (not shown) controls the roll driving motor to rotate the horizontal roll 24 at a predetermined speed. The flexible band 26 circulates in a predetermined direction in accordance with the rotation of the horizontal roll 24, and the horizontal roll 25 rotates in accordance with the movement of the flexible band 26. Hereinafter, the moving direction of the flexible band 26 is called X direction, the width direction of the flexible band 26 is called Y direction, and the vertical direction is called Z direction.

It is preferable that the moving speed V _26a of the surface (henceforth a flexible surface) 26a of the flexible band 26 is 200 m / min or less. When the moving speed V _26a exceeds 200 m / min, it becomes difficult to stably form the beads. The lower limit of the moving speed V _26a may consider productivity of the target film. The lower limit of the movement speed V _26a is, for example, 10 m / min, that is, the movement speed V _26a is, for example, 10 m / min or more.

The flexible band 26 is preferably made of stainless steel, and more preferably made of SUS316 having sufficient corrosion resistance and strength. It is preferable that the width | variety of the flexible band 26 is 1.1 times or more and 2.0 times or less of the flexible width of the dope 12, for example. It is preferable that the length of the flexible band 26 is 20 m or more and 200 m or less, for example, and it is preferable that the thickness of the flexible band 26 is 0.5 mm or more and 2.5 mm or less, for example. In addition, it is preferable to use the flexible band 26 whose thickness variation is 0.5% or less with respect to the whole thickness. It is preferable that the flexible surface 26a is polished, and it is preferable that the surface roughness of the flexible surface 26a is 0.05 micrometer or less.

In addition, in order to set the temperature of the flexible surface 26a of the flexible band 26 to a predetermined value, it is preferable that a heating device (not shown) is attached to the horizontal rolls 24 and 25. It is preferable that the surface temperature of the flexible band 26 is adjustable to 10 to 40 degreeC. The thermostat circulates the heat transfer medium adjusted to the desired temperature under the control of the controller in a flow path provided in the roll bodies 24b and 25b. By circulation of this heat transfer medium, the temperatures of the roll bodies 24b and 25b can be maintained at a desired temperature.

Moreover, in the casing 23, the 1st-3rd sealing members 31-33 are sequentially arrange | positioned toward the downstream side from the X direction upstream. By the 1st-3rd sealing members 31-33, the inside of the casing 23 is divided into the casting chamber 23a, the drying chamber 23b, and the peeling chamber 23c toward the downstream side from the X-direction upstream. . The airtightness of the flexible chamber 23a is maintained by the first to second seal members 31 to 32. In addition, the airtightness of the drying chamber 23b is maintained by the 2nd-3rd sealing members 32-33.

The 1st sealing member 31 consists of the windshield 31a attached to the casing 23, and the labyrinth seal 31b attached to the windshield 31a. The windshield 31a has a windshield that blocks the flow of gas in the casing 23. The windshield may be orthogonal to the X direction or may cross at an angle to the X direction. The windshield 31a protrudes from the inner wall surface of the casing 23 and extends toward the flexible surface 26a of the flexible band 26. Moreover, you may provide the windshield 31a so that it may protrude from a ceiling.

The labyrinth seal 31b is provided at the tip of the windshield 31a so as to be close to the flexible surface 26a. The labyrinth seal 31b is preferably provided to be close to the flexible surface 26a of the portion wound on the horizontal roll 24 of the flexible band 26. The distance between the labyrinth seal 31b and the flexible surface 26a is 1.5 mm or more and 2.0 mm or less, for example.

The 2nd seal member 32 consists of the windshield 32a attached to the casing 23, and the labyrinth seal 32b attached to the windshield 32a. The windshield 32a has the same shape as the windshield 31a, protrudes from the ceiling in the casing 23, and extends toward the flexible surface 26a of the flexible band 26. The labyrinth seal 32b has the same shape as the labyrinth seal 31b and is provided at the tip of the windshield 32a so as to be close to the flexible surface 26a. The labyrinth seal 32b is preferably provided to be close to the flexible surface 26a of the portion wound on the horizontal roll 24 of the flexible band 26. The distance between the labyrinth seal 32b and the flexible surface 26a is 1.0 mm or more and 1.5 mm or less, for example.

The third seal member 33 includes a windshield 33a attached to the casing 23 and a labyrinth seal 33b attached to the windshield 33a. The windshield 33a has the same shape as the windshield 31a, protrudes from the inner wall surface of the casing 23, and extends toward the flexible surface 26a of the flexible band 26. The labyrinth seal 33b has the same shape as the labyrinth seal 31b and is provided at the tip of the windshield 33a so as to be close to the flexible surface 26a. The distance between the labyrinth seal 33b and the flexible surface 26a is 1.5 mm or more and 2.0 mm or less, for example.

(Flexible room)

The flexible die 40 and the pressure reduction unit 41 are provided in the flexible chamber 23a. The casting die 40 has the dope outlet 40a which flows out the dope 12, and is arrange | positioned above the horizontal roll 24 so that the dope outlet 40a may approach the flexible band 26. As shown in FIG.

The casting die 40 flows out the dope 12 from the dope outlet 40a toward the casting band 26. The dope 12 until it flows out from the dope outlet 40a and reaches the flexible surface 26a forms a bead. The dope 12 which reached the flexible surface 26a flows in the X direction, and forms the strip | belt-shaped flexible film 43 as a result.

The decompression unit 41 is for depressurizing the upstream side of the bead in the X direction, and includes a decompression chamber 41a, a decompression fan 41b, and a suction pipe 41c. The decompression chamber 41a is disposed on the upstream side in the X direction than the dope outlet 40a of the casting die 40. The pressure reduction fan 41b sucks gas in the pressure reduction chamber 41a. The suction pipe 41c connects the decompression fan 41b and the decompression chamber 41a.

(Drying room)

In the drying chamber 23b, the 1st drying unit 51-the 3rd drying unit 53 which supply predetermined | prescribed dry wind to the casting film 43 are provided one by one toward the downstream from the X-direction upstream. The first drying unit 51 and the second drying unit 52 are disposed above the flexible band 26 spanning the horizontal rollers 24 and 25. The third drying unit 53 is disposed below the flexible band 26 spanning the horizontal rollers 24 and 25.

(First drying unit)

As shown in FIG. 3 and FIG. 4, the first drying unit 51 includes a first air supply duct 57, a cover 58, a first exhaust duct 59, and a first air supply nozzle 60. Is made of. The first air supply duct 57, the cover 58, and the first exhaust duct 59 are provided in order from the upstream side in the X direction toward the downstream side. The first air supply nozzle 60 is installed in the first air supply duct 57.

(First air supply duct)

As shown to FIG. 4 and FIG. 5, the 1st air supply duct 57 distribute | circulates the 1st dry wind 61, and is close to the 2nd seal member 32 in the X direction, and is Z direction. It is spaced apart from the flexible film 43. The 1st air supply nozzle 60 is provided in the lower surface 57a of the 1st air supply duct 57, and is provided with the 1st air supply port 60a which the 1st dry air 61 is sent out. The first air supply nozzle 60 extends in the X-direction downstream side toward the delivery direction of the first drying wind 61. The first air supply mechanism 60a opened in the lower surface 57a of the first air supply duct 57 extends from one end of the flexible membrane 43 to the other end.

(First exhaust duct)

The 1st exhaust duct 59 distributes the 1st dry wind 61, and is arrange | positioned apart from the flexible film 43 in a Z direction. On the lower surface of the first exhaust duct 59, a first exhaust port 59a for exhausting the first drying wind 61 is opened to face the flexible film 43. The first exhaust port 59a extends from one end of the flexible membrane 43 to the other end.

(cover)

The cover 58 guides the 1st dry air 61 sent from the 1st air supply port 60a to the 1st exhaust port 59a, Comprising: In the state which is away from the casting film 43 in a Z direction, the flexible film ( 43). The cover 58 is formed in a plate shape and extends from the first air supply duct 57 to the first exhaust duct 59 in the X direction and extends from one end of the flexible membrane 43 to the other end in the Y direction. . The lower surface of the cover 58 has a guide surface 58a that is substantially parallel to the flexible film 43. It is preferable that the guide surface 58a coincides with the lower surface 57a of the first air supply duct 57 and the lower surface of the first exhaust duct 59.

As shown in FIG. 4 and FIG. 6, the side windshields 65 arranged in the Y direction extend from the first air supply duct 57 over the first exhaust duct 59. The side windshields 65 extend from the lower surface 57a and the guide surface 58a toward the flexible film 43. It is preferable that the surface 65b of the inner side of the side windshield 65 in the Y direction coincides with the inner surface 60b of the first air supply nozzle 60. The first air supply port is surrounded by the guide surface 58a and the lower surface 57a, the flexible membrane 43, and the side windshield 65 from the first air supply port 60a to the first exhaust port 59a. The 1st dry air path 66 of the 1st dry air 61 sent out from 60a is formed. The width of the first drying air passage 66 in the Z direction may be determined depending on the width W ₄₃ of the flexible film 43, for example, (W ₄₃ -60) mm or more (W ₄₃ -20). It is preferable that it is mm or less. The length of the first drying air duct 66 in the X direction, is determined according to the production conditions (a flexible band 26, flexible surface (26a) the moving speed (V _26a) such as a), for example, 2000mm It is preferable that it is more than 3000 mm.

(Second drying unit)

As shown in FIG. 2, the plurality of second drying units 52 are arranged in the X direction. As shown in FIG. 3, the second drying unit 52 includes a second air supply duct 71, a second air exhaust duct 72, and a second air supply nozzle 73. As shown to FIG. 4 and FIG. 7, the 2nd air supply duct 71 distribute | circulates the 2nd dry air 75, and is arrange | positioned apart from the casting film 43. As shown to FIG. The second air supply nozzle 73 provided in the second air supply duct 71 extends substantially vertically from the lower surface of the second air supply duct 71 toward the flexible membrane 43. As shown in FIG.4 and FIG.8, the 2nd air supply port 73a through which the 2nd dry air 75 is sent is provided in the front-end | tip of the 2nd air supply nozzle 73 which adjoins the casting film 43. As shown in FIG. It is preferable that the space | interval of the 2nd air supply port 73a and the flexible film 43 is 100 mm or more and 200 mm or less, for example. The second air supply 73a extends from one end of the flexible membrane 43 to the other end.

The 2nd exhaust duct 72 has the 2nd exhaust port 72a which exhausts the 2nd dry wind 75, and is arrange | positioned downstream from the 2nd air supply nozzle 73 in the X direction. The 2nd exhaust port 72a is arrange | positioned above the 2nd air supply port 73a on the both sides of the 2nd air supply port 73a in the Y direction. It is preferable that the 2nd air supply port 73a and the 2nd exhaust port 72a are alternately arrange | positioned in a X direction.

(Third drying unit)

As shown in FIG. 2, the 3rd drying unit 53 consists of the 3rd exhaust duct 81 and the 3rd air supply duct 82 provided one by one from the upstream to the X direction downstream. The 3rd exhaust duct 81 and the 3rd air supply duct 82 are arrange | positioned apart from the flexible band 26, respectively. The third exhaust duct 81 is provided with a third exhaust port 81a for exhausting the third drying wind 84. The third exhaust port 81a, which is opened toward the downstream in the X direction, extends from one end of the flexible membrane 43 to the other end. The third air supply duct 82 is provided with a third air supply port 82a through which the third drying air 84 is sent out. The third air supply port 82a opened toward the upstream side in the X direction extends from one end of the flexible membrane 43 to the other end.

The 1st-3rd blowing fan (not shown) and the 1st-3rd air conditioners (not shown) are provided in the 1st drying unit 51-the 3rd drying unit 53, respectively. The control unit 85 is connected to the first to third blowing fans and the first to third warmers. The control unit 85 independently adjusts the temperature and the wind speed with respect to the first drying wind 61, the second drying wind 75, and the third drying wind 84.

(Peeling room)

The peeling roller 86 is provided in the peeling chamber 23c. The peeling roller 86 peels the flexible film 43 which became the peelable state from the flexible band 26, and turns it into the wet film 13, and the wet film 13 from the outlet 23o provided in the peeling chamber 23c. Send the.

In the casting apparatus 15, a condensation apparatus for condensing the solvent contained in the atmosphere in the casing 23 and a recovery apparatus for recovering the condensed solvent may be provided. Thereby, the density | concentration of the solvent contained in the atmosphere in the casing 23 can be maintained in a fixed range.

Returning to FIG. 1, a plurality of supporting rollers 87 supporting the wet film 35 are arranged in the moving portion between the flexible device 15 and the clip tenter 17. The support roller 87 rotates about an axis by the motor which is not shown in figure. The support roller 87 supports the wet film 35 sent out from the casting apparatus 15 and guides it to the clip tenter 17. In addition, although the case where two support rollers 87 were arranged in the moving part is shown in FIG. 1, this invention is not limited to this, Even if one or three or more support rollers 87 are arranged in the moving part, do. In addition, the support roller 87 may be a free roller (non-drive roller).

The clip tenter 17 has many clips which hold | grip the width direction both edge part of the wet film 13, and this clip moves on an extension track | orbit. Dry air is sent to the wet film 13 gripped by the clip, and the wet film 13 is subjected to a drying treatment together with the stretching treatment in the width direction.

An edge cutting device 88 is provided between the clip tenter 17 and the drying device 18. Both ends of the width direction of the film 16 sent to the edge cutting device 88 are formed with the gripping marks formed by the clip. The edge cutting device 88 cuts off both end portions having the gripping marks. This cut part is sent to a cut blower (not shown) and crusher (not shown) in order by blowing, it is cut finely, and is recycled as raw materials, such as dope.

The drying apparatus 18 has the casing provided with the conveyance path of the film 16, the some roller 18a which forms the conveyance path of the film 16, and the air conditioner which adjusts the temperature and humidity of the atmosphere in a casing ( Not shown). The film 16 introduced into the casing is conveyed while being wound by the plurality of rollers 18a. By controlling the temperature and humidity of this atmosphere, the solvent remaining from the film 16 conveyed in the casing is evaporated. In addition, an adsorption recovery apparatus (not shown) that recovers the solvent evaporated from the film 16 by adsorption is connected to the drying apparatus 18.

Between the drying apparatus 18 and the winding apparatus 19, the cooling chamber 89, the antistatic bar (not shown), the knurling provision roller 90, and the edge cutting device (not shown) are provided in order from an upstream side. Is installed. The cooling chamber 89 cools the film 16 until the temperature of the film 16 becomes substantially room temperature. The antistatic bar is sent out from the cooling chamber 89 to perform an antistatic process for removing electricity from the charged film 16. The knurling provision roller 90 imparts knurling for winding to both ends of the width direction of the film 16. The edge cutting device cut | disconnects the width direction both ends of the film 16 so that knurling may remain in the width direction both ends of the film 16 after cutting | disconnection.

The winding apparatus 19 has the press roller 19a and the winding core 19b. The film 16 sent to the winding apparatus 19 is wound up by the winding core 19b, being pressed by the press roller 19a, and turns into a roll shape.

Next, the operation of the present invention will be described. As shown in FIG. 2, each of the seals 23a to 23b having airtightness is formed in the casing 23 by the first to third seal members 31 to 33. The flexible band 26 sequentially passes through the chambers 23a to 23c.

(Flexible process)

In the casting chamber 23a, a casting step of forming the casting film 43 made of the dope 12 on the casting band 26 is performed. The casting die 40 continuously flows out the dope 12 from the dope outlet 40a. The dope 12 which flowed out forms the beads from the casting die 40 to the flexible band 26, and flows on the flexible band 26. In this way, the flexible film 43 which consists of the dope 12 is formed on the flexible band 26 (refer FIG. 9).

Returning to FIG. 2, the decompression unit 41 can create a state in which the pressure on the X-direction upstream side of the bead is lower than the pressure on the X-direction downstream side of the bead. It is preferable that the pressure difference (DELTA) P of the X direction upstream and X direction downstream of a bead is 10 Pa or more and 2000 Pa or less.

(Drying process)

In the drying chamber 23b, predetermined drying air is made to flow in the casting film 43, and the drying process which evaporates a solvent from the casting film 43 is performed. The drying process is performed until the casting film 43 becomes a state which can be self-supporting and conveyed. In a drying process, a 1st drying process, a 2nd drying process, and a 3rd drying process are performed sequentially.

(First drying process)

In the first drying step, the solvent is evaporated from the flexible film 43 until a dry layer 43a (see FIG. 10) is formed on the surface layer of the flexible film 43. As shown in FIG. 5, the first drying unit 51 sends the first drying air 61 from the first air supply port 60a. It is preferable that it is 30 degreeC or more and 60 degrees or less, and, as for the angle (theta) 1 of the direction which the direction of the 1st dry wind 61 sent out from the 1st air supply 60a and Z1 direction make, it is more preferable that it is 45 degrees. By the cover 58, the 1st dry air 61 sent out from the 1st air supply port 60a is guide | induced to the 1st exhaust port 59a. And the 1st drying wind 61 is exhausted from the 1st exhaust port 59a.

The cover 58 proximate to the cast film 43 makes it possible to increase the wind speed in the vicinity of the surface of the cast film 43, thereby promoting evaporation of the solvent from the surface of the cast film 43. Moreover, the guide surface 58a rectifies the 1st dry wind 61, and it has an effect which suppresses the dry unevenness of the casting film 43. By this 1st drying process, the cast film 43 will have a dry layer 43a and a wet layer 43b (refer FIG. 10). The dry layer 43a is a portion which is formed on the surface side of the flexible film 43 and is dried compared with the wet layer 43b located on the flexible band 26 side than the dry layer 43a. Therefore, content of the solvent of the dry layer 43a is low compared with the wet layer 43b. Moreover, the surface of the dry layer 43a is formed smoothly. When the predetermined drying process is performed with respect to the flexible film 43 which has a dry layer 43a, the surface of the dry layer 43a becomes the surface of the obtained flexible film 43. As shown in FIG. Therefore, by forming the dry layer 43a in the cast film 43 immediately after formation, the cast film 43 with a smooth surface can be obtained.

Here, content of a solvent shows the quantity of the solvent contained in a flexible film or each film on a dry basis, When taking a sample from the target film and making the mass of this sample x and the mass after drying a sample, y , X (xy) / y｝ x100.

It is preferable to perform a 1st drying process with respect to the flexible film 43 whose content of a solvent is 250 mass% or more and 400 mass% or less, and performs content with respect to the flexible film 43 whose content of a solvent is 300 mass% or more and 350 mass% or less. It is more preferable. It is preferable that the temperature of the 1st drying wind 61 is 30 degreeC or more and 80 degrees C or less. Moreover, it is preferable that the wind speed of the 1st drying wind 61 is 5 m / sec or more and 25 m / sec or less.

(2nd drying process)

In the 2nd drying process, as shown in FIG. 8, the solvent is evaporated from the casting film 43 using the 2nd drying wind 75. FIG. The 2nd air supply nozzle 73 makes the 2nd dry air 75 run perpendicular to the casting film 43. As a result, when the 2nd dry wind 75 touches the surface of the flexible film 43, the stagnation point P is produced | generated near the surface side of the flexible film 43 by the branch of the 2nd dry wind 75. FIG. .

As a method of judging whether or not a stagnation point P is being generated near the surface side of the flexible film 43, if the wind direction observed by the wind stalk arranged near the surface side of the flexible film 43 is branched, You may judge that the point P is generating.

At the stagnation point P, the thermal energy of the second drying wind 75 is likely to be transmitted to the flexible membrane 43. In this way, the solvent evaporates in the casting film 43 by the contact with the second drying wind 75. It is preferable to perform a 2nd film drying process with respect to the flexible film 43 whose content of a solvent is 150 mass% or more and 300 mass% or less. It is preferable that the temperature of the 2nd drying wind 75 is 30 degreeC or more and 80 degrees C or less. Moreover, it is preferable that the wind speed of the 2nd drying wind 75 is 5 m / sec or more and 25 m / sec or less.

(3rd drying process)

In the 3rd drying process, the solvent is evaporated from the casting film 43 until it becomes the state which can be independent and conveyed using the 3rd drying air 84 (refer FIG. 2). The third drying unit 53 flows the third drying wind 84 along the surface of the casting film 43 from the downstream side in the X direction toward the upstream side. In this way, by flowing the third drying wind 84 in the opposite direction to the X direction, evaporation of the solvent is promoted as compared with the case where the third drying wind 84 is flowed in the X direction. It is preferable to perform a 3rd film drying process with respect to the flexible film 43 whose content of a solvent is 20 mass% or more and 150 mass% or less. It is preferable that the temperature of the 3rd drying wind 84 is 40 degreeC or more and 80 degrees C or less. Moreover, it is preferable that the wind speed of the 3rd drying wind 84 is 5 m / sec or more and 20 m / sec or less.

(Peeling process)

In the peeling chamber 23c, the peeling process which peels the flexible film 43 which became the peelable state from the flexible band 26 is performed. The peeling roller 86 peels the flexible film 43 which became the peelable state from the flexible band 26, and turns it into the wet film 13, and the wet film 13 from the outlet 23o provided in the peeling chamber 23c. Send the. It is preferable to perform a peeling process with respect to the flexible film 43 whose content of a solvent is 20 mass% or more and 80 mass% or less.

When returning to a 1st drying process and the speed of the 1st drying wind 61 increased, the 1st drying wind 61 flows in between the 2nd air supply nozzle 73 and the flexible film 43. . By the 1st dry wind 61, the 2nd dry wind 75 is extruded downstream of a X direction. As a result, in the second drying step, the second drying wind 75 does not touch the flexible film 43. Therefore, as shown in FIG. 11, the stagnation point P for the second drying wind 75 is not generated. In addition, the 1st drying wind 61 which touches the flexible film 43 in a 2nd drying process has a low drying capability compared with the 2nd drying wind 75. In this case, the drying efficiency in a 2nd drying process will fall.

In the present invention, since the first drying unit 51 exhausts the first drying wind 61 from the first exhaust port 59a, between the second air supply nozzle 73 and the flexible membrane 43, the first drying unit 51 exhausts the first drying air 61. The drying wind 61 is suppressed from flowing. Therefore, according to this invention, it is compatible with making the surface of the casting film 43 smoother, and drying the casting film 43 efficiently. Moreover, according to the solution film forming method which performs such a drying process, the film 16 (refer FIG. 1) with a smooth surface can be manufactured efficiently.

Next, 2nd Embodiment which concerns on this invention is described. As shown in FIG. 12, the first drying unit 51 is provided with a first air supply duct 57, a cover 58, and a first rectifying plate 94 sequentially installed from the upstream side in the X direction toward the downstream side. )

The first rectifying plate 94 extending from one end of the flexible membrane 43 to the other stage is disposed so as to stand up with respect to the flexible membrane 43. The lower end 94b of the first rectifying plate 94 is close to the flexible membrane 43, and the upper end 94a of the first rectifying plate 94 extends above the second air supply port 73a. By this 1st rectification plate 94, it can suppress that the 1st dry wind 61 flows between the 2nd air supply nozzle 73 and the casting film 43. As shown in FIG.

In addition, the upper exhaust duct 95 provided above the first rectifying plate 94 may be added to the first drying unit 51. The upper exhaust duct 95 has an upper exhaust port 95a for exhausting the first drying wind 61. It is preferable that the upper end 94a of the 1st rectifying plate 94 extends toward the upper exhaust port 95a. In addition, you may provide the 1st windshield sealing member 96 of the same structure as the 1st sealing member 31 between the 1st drying unit 51 and the 2nd drying unit 52. FIG.

In addition, it is preferable that the lower end 94b of the first rectifying plate 94 extends to the X-direction downstream of the first drying air path 66. As shown, the first rectifying plate 94 may be a flat plate in addition to the curved plate, or may be any combination of a curved plate and a flat plate, a combination of a plurality of curved plates, and a combination of a plurality of flat plates. . It may be a combination of a plurality of flat plates or a combination of a flat plate and a curved plate. Moreover, it is preferable that the 1st rectifying plate 94 is movable in the direction away from the flexible band 26 by operation from the exterior of the casing 23, in order to ensure the integrity at the time of flexible stop. .

In addition, an anemometer for each drying wind is provided in each of the first drying unit 51 and the second drying unit 52 as follows, and the first drying wind 61 of the first drying unit 51 is provided. You may adjust the balance of the 1st drying wind 61 and the 2nd drying wind 75 so that dynamic pressure may become smaller than the dynamic pressure of the 2nd drying wind 75 in the 2nd drying unit 52. Here, "the dynamic pressure of the 1st drying wind 61 in the 1st drying unit 51" means the 1st drying wind 61 between the cover 58 and the flexible film 43 (in FIG. It is the dynamic pressure of 1st dry wind 61x. In addition, when providing the side windshield 65, "the dynamic pressure of the 1st drying wind 61 in the 1st drying unit 51" means the 1st drying in the 1st air supply nozzle 60. FIG. It is good also as a dynamic pressure of the wind 61. "Dynamic pressure of the 2nd drying wind 75 in the 2nd drying unit 52" means the dynamic pressure of the 2nd drying wind 75 between the 2nd air supply nozzle 73 and the flexible film 43. As shown in FIG. to be.

In order to adjust the magnitude relationship between the dynamic pressure of the 1st dry wind 61 and the dynamic pressure of the 2nd dry wind 75, the 1st anemometer 101 (refer FIG. 5) and the 2nd anemometer 102 (FIG. 8) Install it). A first anemometer (101) for measuring the speed (V ₆₁₎ of the dry wind 61, and be provided to the first air supply nozzle 60 as shown in Fig. 5 and the like Pitot tube, the first air supply duct You may convert into the wind speed from the internal pressure of 57, and may convert from the air volume measured by installing a wind volume meter in the duct arrange | positioned between the 1st air supply duct 57 and a 1st blowing fan. The measurement of the speed V ₇₅ of the 2nd dry wind 75 may measure the internal pressure of the 2nd air supply nozzle 73, and may convert it into a wind speed, and between the 2nd air supply duct 71 and the 2nd blowing fan. You may convert from the air volume measured by installing the air volume meter in the arrange | positioned duct (refer FIG. 8). The control unit 85 reads the speeds V ₆₁ and V ₇₅ from the first anemometer 101 and the second anemometer 102, respectively. Next, the control unit 85 is read to embellish rate based on the (V _61, V _75), the value of (V ₆₁ / V ₇₅₎ is less than or equal to 0.6, the first to the second ventilation fan at least the rotation of one of the Control the number. In this way, the state (refer FIG. 11) in which the 2nd dry wind 75 seizes to the X direction downstream by the 1st dry wind 61 can be avoided.

In addition, in order to prevent the first drying wind 61 from flowing backward in the X direction, the control unit 85 may control the rotation speed of at least one of the first to second blowing fans. First to prevent a back flow of the dry wind 61, the velocity (V ₆₁₎ is preferably 20m / sec or less, and, (V ₆₁ / V ₇₅₎ value is less than 0.2 of 0.85.

When controlling the rotation speed of the 1st-2nd blowing fan same as the above-mentioned, the 1st exhaust duct 59 (refer FIG. 5) in 1st Embodiment, and the rectification in 2nd Embodiment The plate 90, the upper exhaust duct 95, and the windshield seal 92 (see FIG. 12) may be omitted.

In addition, you may provide the windshield 105 (refer FIG. 5) between the 1st air supply duct 57 and the 2nd sealing member 32. As shown in FIG. The windshield 105 is disposed in an upright position with respect to the flexible membrane 43. The lower end 105a of the windshield 105 protrudes toward the flexible membrane 43 rather than the lower surface 57a of the first air supply duct 57. The windshield plate 105 can prevent backflow of the first drying wind 61.

Although the installation position of the casting die 40 was set above the horizontal roll 24, this invention is not limited to this. When the seal members 31 to 32 are provided to be close to the portion of the flexible band 26 wound on the horizontal roll 25, the installation position of the flexible die 40 may be above the horizontal roll 24. Moreover, the support roll which supports the flexible band 26 is installed between the horizontal rolls 24 and 25, and the seal members 31-32 are installed so that it may be adjacent to the part of the flexible band 26 supported by the support roll. At this time, the installation position of the flexible die 40 may be above the support roll.

The film 16 obtained by this invention can be used especially for retardation film and a polarizing plate protective film.

It is preferable that it is 600 mm or more, and, as for the width | variety of the film 16, it is more preferable that they are 1400 mm or more and 2500 mm or less. Moreover, this invention is effective also when the width | variety of the film 16 is larger than 2500 mm. Moreover, it is preferable that the film thickness of the film 16 is 30 micrometers or more and 120 micrometers or less.

Moreover, it is preferable that in-plane retardation Re of the film 16 is 20 nm or more and 300 nm or less, and it is preferable that the thickness direction retardation Rth of the film 16 is -100 nm or more and 300 nm or less.

The measuring method of in-plane retardation Re is as follows. In-plane retardation Re humidifies a sample film at a temperature of 25 degreeC, and 60% RH for 2 hours, and the retardation measured from the vertical direction in 632.8 nm with automatic birefringence meter (KOBRA21DH Oji measurement Co., Ltd.). Value was used. Re is represented by the following formula.

Re = | n1-n2 | × d

n1 represents the refractive index of the slow axis, n2 represents the refractive index of the fast axis 2, and d represents the thickness (film thickness) of the film.

The measuring method of thickness direction retardation Rth is as follows. The sample film was humidified for 2 hours at a temperature of 25 ° C. and a humidity of 60% RH, and was measured in the same manner while tilting the film surface and the value measured from the vertical direction at 632.8 nm with an lipometer (M150 Nihon Bunco Co., Ltd.). It was computed according to the following formula from the extrapolation value of one retardation value.

Rth = ｛(n1 + n2) / 2-n3｝ × d

n3 represents the refractive index of the thickness direction.

(Polymer)

In the said embodiment, the polymer used as a raw material of a polymer film is not specifically limited, For example, a cellulose acylate, a cyclic polyolefin, etc. are mentioned.

(Cellulose acylate)

Only one kind of acyl group may be used for the cellulose acylate of the present invention, or two or more kinds of acyl groups may be used. When using two or more types of acyl groups, it is preferable that one is an acetyl group. It is preferable that the ratio which esterifies the hydroxyl group of a cellulose with carboxylic acid, ie, the substitution degree of an acyl group, satisfy | fills all of following formula (I)-(III). In the following formulas (I) to (III), A and B represent a degree of substitution of an acyl group, A is a degree of substitution of an acetyl group, and B is a substitution of an acyl group having 3 to 22 carbon atoms. It is also. Moreover, it is preferable that 90 mass% or more of triacetyl cellulose (TAC) is 0.1 mm-4 mm of particle | grains.

(I) 2.0≤A + B≤3.0

(II) 1.0≤A≤3.0

(III) 0≤B≤2.0

As for all the substitution degree (A + B) of an acyl group, it is more preferable that it is 2.20 or more and 2.90 or less, and it is especially preferable that it is 2.40 or more and 2.88 or less. Moreover, it is more preferable that substitution degree B of the acyl group of C3-C22 is 0.30 or more, and it is especially preferable that it is 0.5 or more.

The cellulose which is a raw material of cellulose acylate may be one obtained from any of a linter and a pulp.

The acyl group having 2 or more carbon atoms of the cellulose acylate of the present invention may be either an aliphatic group or an aryl group, and is not particularly limited. They are alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkylcarbonyl ester, etc. of cellulose, for example, and may have a group substituted further, respectively. Preferred examples thereof include propionyl, butanoyl, pentanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t- Butanoyl, cyclohexanecarbonyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like. Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are more preferable, and particularly preferably propionyl and butanoyl .

(solvent)

Examples of the solvent for preparing the dope include aromatic hydrocarbons (for example, benzene and toluene), halogenated hydrocarbons (for example, dichloromethane and chlorobenzene), alcohols (for example, methanol, ethanol, n-propanol, n Butanol, diethylene glycol, etc.), ketones (e.g., acetone, methyl ethyl ketone, etc.), esters (e.g., methyl acetate, ethyl acetate, propyl acetate, etc.) and ethers (e.g., tetrahydrofuran, Methyl cellosolve, etc.) etc. are mentioned. In addition, in this invention, dope means the polymer solution and dispersion liquid obtained by melt | dissolving or disperse | distributing a polymer in a solvent.

Among these, halogenated hydrocarbons having 1 to 7 carbon atoms are preferably used, and dichloromethane is most preferably used. From the viewpoints of physical properties such as solubility of the polymer, peelability from the support of the flexible membrane, mechanical strength of the film, and optical properties of the film, it is preferable to mix one or more kinds of alcohols having 1 to 5 carbon atoms in addition to dichloromethane. Do. 2 mass%-25 mass% are preferable with respect to the whole solvent, and, as for content of alcohol, 5 mass%-20 mass% are more preferable. Specific examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol and the like, but methanol, ethanol, n-butanol or a mixture thereof is preferably used.

By the way, in order to minimize the influence on the environment in recent years, the examination of the solvent composition in the case of not using dichloromethane is advanced, and about this objective, it is an ether of 4-12 carbon atoms, and a carbon atom about this objective. Ketones of 3 to 12 carbon atoms, esters of 3 to 12 carbon atoms, and alcohols of 1 to 12 carbon atoms are preferably used. These may be mixed and used suitably. For example, the mixed solvent of methyl acetate, acetone, ethanol, n-butanol is mentioned. Such ethers, ketones, esters and alcohols may have a cyclic structure. Moreover, the compound which has two or more of functional groups of ether, ketone, ester, and alcohol (namely, -O-, -CO-, -COO-, and -OH) can also be used as a solvent.

The details of the cellulose acylate are described in paragraphs [0140] to [0195] of Japanese Patent Laid-Open No. 2005-104148. Such a description is also applicable to this invention. Moreover, about the same additives, such as a solvent and a plasticizer, a deterioration inhibitor, a ultraviolet absorber (UV agent), an optically anisotropic control agent, a retardation control agent, a dye, a mat agent, a peeling agent, a peeling accelerator, It is described in detail in paragraph [0516] to paragraph [0516].

In the said embodiment, although the flexible film was formed using this invention, this invention is not limited to this, It is applicable also when apply | coating a coating liquid to a support body and forming a coating film on a support body. That is, according to this invention, it becomes possible to form the coating film with a smooth surface efficiently.

EXAMPLE

(Experiment 1)

In the solution forming equipment 10 shown in FIG. 1, the film 16 was made. In the casting apparatus 15, the casting step, the drying step, and the peeling step were sequentially performed. In a drying process, the 1st drying process, the 2nd drying process, and the 3rd drying process were performed sequentially. In the first drying step, the first drying wind ₆₁ was blown into the flexible membrane 43 at a wind speed V ₆₁ . In the second drying step, the second drying wind ₇₅ was blown into the flexible membrane 43 at a wind speed V ₇₅ .

(Experiment 2-25)

A film 16 was produced in the same manner as in Experiment 1 except that the wind speeds V ₆₁ and V ₇₅ were adjusted to the values shown in Table 1.

(evaluation)

About the film 16 obtained by the experiments 1-25, the following items were evaluated.

1. Peelability Evaluation

The peelability of the cast film was performed based on the following criteria.

A: The whole flexible film could be peeled from a flexible band.

B: Some of the flexible film remained on the support.

2. Face Shape Evaluation

By visual observation, the planar shape of the flexible membrane was observed and carried out based on the following criteria.

A: The film surface is smooth.

B: Weak irregularities are seen on the surface of the film.

3. Evaluation of Backflow of the First Dry Wind

The pressure P1 between the windshield 105 (refer FIG. 5) and the flexible membrane 43 and the pressure P2 in the flexible chamber 23a were measured using the pressure gauge. The pressure P2 is measured by arranging the open end of the tube connected to the pressure gauge between the windshield 105 (see FIG. 5) and the flexible membrane 43. In addition, what remove | extracted the pressure P1 from the pressure P2 was made into dynamic pressure.

A: The calculated dynamic pressure was less than 1.0 Pa.

B: The calculated dynamic pressure was 1.0 Pa or more.

Also in any of said 1-3, A passes and B fails.

Table 1 shows the values of V ₆₁ , V ₇₅ , and (V ₆₁ / V ₇₅ ) in the experiments 1 to 25 and the above evaluation results. In addition, the number added to the evaluation result of Table 1 shows the number attached to the said evaluation item.

Wind speed condition Evaluation results V ₆₁ V ₇₅

One 2 3 Experiment 1 5.0 25.1 0.20 A B A Experiment 2 5.2 22.7 0.23 A B A Experiment 3 5.9 19.9 0.30 A B A Experiment 4 5.8 17.4 0.33 A B A Experiment 5 6.0 14.9 0.40 A B A Experiment 6 7.8 24.9 0.31 A B A Experiment 7 8.1 22.5 0.36 A B A Experiment 8 8.5 20.1 0.42 A A A Experiment 9 8.8 17.3 0.51 A A A Experiment 10 8.9 14.8 0.60 A A A Experiment 11 11.0 24.9 0.44 A A A Experiment 12 11.3 22.3 0.51 A A A Experiment 13 11.5 19.9 0.58 A A A Experiment 14 11.6 17.2 0.68 B A A Experiment 15 11.6 14.6 0.80 B A A Experiment 16 13.4 24.7 0.54 A A A Experiment 17 13.7 22.1 0.62 B A A Experiment 18 14.4 19.5 0.74 B A A Experiment 19 14.2 16.8 0.85 B A A Experiment 20 14.1 14.4 0.98 B A B Experiment 21 16.5 24.5 0.67 B A A Experiment 22 17.0 22.1 0.77 B A A Experiment 23 17.2 19.6 0.88 B A B Experiment 24 16.8 16.7 1.01 B A B Experiment 25 17.3 14.2 1.22 B A B

Claims (12)

A drying apparatus for drying a film formed on a moving support,
A cover covering the membrane;
A first air supply port for sending the first dry wind;
A first drying unit having the cover and the first air supply port;
A second air supply port for sending a second dry wind;
A second drying unit having the second air supply; And,
A control unit controlling at least one of the wind speed V1 of the first drying wind and the wind speed V2 of the second drying wind;
And,
The membrane comprises a polymer and a solvent,
The first air supply port is provided upstream of the moving direction of the moving support body than the cover, and the first air supply air feeds the first drying wind toward the cover and the membrane.
The first drying unit sends the first drying wind from the first air supply port until a dry layer is formed on the surface side of the film by evaporation of the solvent,
The second air supply port is installed on the downstream side of the moving direction of the moving support body than the cover, and the second air supply air blows out the second dry wind which is approximately vertical toward the surface of the membrane,
The second drying unit accelerates the evaporation of the solvent by impinging the second drying wind on the surface of the membrane,
The control unit controls at least one of the wind speed V1 and the wind speed V2 so that a collision of the second dry wind with the surface of the film is maintained.
Drying device. The method according to claim 1,
Drying apparatus whose value of V1 / V2 is 0.6 or less. The method according to claim 1,
And an exhaust part for exhausting the first drying wind, wherein the exhaust part is provided between the cover and the second air supply port. A drying apparatus for drying a film formed on a moving support,
A cover covering the membrane;
A first air supply port for sending the first dry wind;
A first drying unit having the cover and the first air supply port;
A second air supply port for sending a second dry wind;
A second drying unit having the second air supply; And,
An exhaust unit for exhausting the first drying wind;
And,
The membrane comprises a polymer and a solvent,
The first air supply port is installed upstream of the moving direction of the moving support body than the cover, and the first air supply air blows out the first drying wind toward the cover and the membrane.
The first drying unit sends the first drying wind from the first air supply port until a dry layer is formed on the surface side of the film by evaporation of the solvent,
The second air supply port is installed on the downstream side of the moving direction of the moving support body than the cover, and the second air supply air blows out the second dry wind which is approximately vertical toward the surface of the membrane,
The second drying unit accelerates the evaporation of the solvent by impinging the second drying wind on the surface of the membrane,
The exhaust part is provided between the cover and the second air supply port.
Drying device. The method according to claim 1,
And a windshield to block the first drying wind flowing from the first air supply port toward the second air supply port. A drying apparatus for drying a film formed on a moving support,
A cover covering the membrane;
A first air supply port for sending the first dry wind;
A first drying unit having the cover and the first air supply port;
A second air supply port for sending a second dry wind;
A second drying unit having the second air supply; and,
A windshield to block the first drying wind flowing from the first air supply port toward the second air supply port;
And,
The membrane comprises a polymer and a solvent,
The first air supply port is installed upstream of the moving direction of the moving support body than the cover, and the first air supply air blows out the first drying wind toward the cover and the membrane.
The first drying unit sends the first drying wind from the first air supply port until a dry layer is formed on the surface side of the film by evaporation of the solvent,
The second air supply port is installed on the downstream side of the moving direction of the moving support body than the cover, and the second air supply air blows out the second dry wind which is approximately vertical toward the surface of the membrane,
The second drying unit accelerates the evaporation of the solvent by impinging the second drying wind on the surface of the membrane,
The windshield is installed between the cover and the second air supply.
Drying device. A method of drying a film for drying a film formed on a moving support,
Sending the first drying air from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent;
Promoting evaporation of the solvent by impinging a second drying wind from a second drying unit on the surface of the membrane; And,
Controlling at least one of the wind speed V1 of the first drying wind and the wind speed V2 of the second drying wind;
And,
The membrane comprises a polymer and a solvent,
The first drying unit has a cover and the first air supply, the cover covers the membrane, and the first air supply is provided upstream of the moving direction of the moving support than the cover, and the first air supply is provided. Sends a first drying wind toward the cover and the membrane;
The second drying unit has a second air supply, the second air supply emits the second drying wind which is approximately vertical toward the surface of the membrane, and the second air supply is moved by the moving support rather than by the cover. Sending the second drying wind on the downstream side in the direction,
At least one of the wind speed V1 and the wind speed V2 is controlled such that a collision of the second dry wind to the surface of the film is maintained.
Method of drying the membrane. A method of drying a film for drying a film formed on a moving support,
(A) sending a first drying wind from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent;
(B) promoting the evaporation of the solvent by impinging a second drying wind from the second drying unit on the surface of the membrane; And,
(C) exhausting the first dry wind;
And,
The membrane comprises a polymer and a solvent,
The first drying unit has a cover and the first air supply, the cover covers the membrane, and the first air supply is provided upstream of the moving direction of the moving support than the cover, and the first air supply is provided. Sends a first drying wind toward the cover and the membrane;
The second drying unit has a second air supply, the second air supply emits the second drying wind which is approximately vertical toward the surface of the membrane, and the second air supply is moved by the moving support rather than by the cover. Sending the second drying wind on the downstream side in the direction,
The evacuation is performed between the step A and the step B.
Method of drying the membrane. A method of drying a film for drying a film formed on a moving support,
(D) sending a first drying wind from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent;
(E) promoting the evaporation of the solvent by impinging a second drying wind from the second drying unit on the surface of the membrane; And,
(F) blocking the first drying wind flowing toward the second air supply port between the step D and the step E;
And,
The membrane comprises a polymer and a solvent,
The first drying unit has a cover and the first air supply, the cover covers the membrane, and the first air supply is provided upstream of the moving direction of the moving support than the cover, and the first air supply is provided. Sends a first drying wind toward the cover and the membrane;
The second drying unit has a second air supply, the second air supply emits the second drying wind which is approximately vertical toward the surface of the membrane, and the second air supply is moved by the moving support rather than by the cover. To send out the second drying wind on the downstream side in the direction
Method of drying the membrane. A solution film forming method for manufacturing a film by drying a film formed on a moving support,
(G) sending a first drying wind from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent;
(H) promoting the evaporation of the solvent by impinging a second drying wind from the second drying unit on the surface of the membrane;
(I) controlling at least one of the wind speed V1 of the first dry wind and the wind speed V2 of the second dry wind; And,
(J) peeling the film after the H step from the moving support to form a film;
And,
The membrane comprises a polymer and a solvent,
The first drying unit has a cover and the first air supply, the cover covers the membrane, and the first air supply is provided upstream of the moving direction of the moving support than the cover, and the first air supply is provided. Sends a first drying wind toward the cover and the membrane;
The second drying unit has a second air supply, the second air supply emits the second drying wind which is approximately vertical toward the surface of the membrane, and the second air supply is moved by the moving support rather than by the cover. Sending the second drying wind on the downstream side in the direction,
At least one of the wind speed V1 and the wind speed V2 is controlled such that a collision of the second dry wind to the surface of the film is maintained.
Solution film formation method. A solution film forming method for manufacturing a film by drying a film formed on a moving support,
(A) sending a first drying wind from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent;
(B) promoting the evaporation of the solvent by impinging a second drying wind from the second drying unit on the surface of the membrane;
(C) exhausting the first dry wind; And,
(K) peeling the film after the step B from the moving support to form a film;
And,
The membrane comprises a polymer and a solvent,
The first drying unit has a cover and the first air supply, the cover covers the membrane, and the first air supply is provided upstream of the moving direction of the moving support than the cover, and the first air supply is provided. Sends a first drying wind toward the cover and the membrane;
The second drying unit has a second air supply, the second air supply emits the second drying wind which is approximately vertical toward the surface of the membrane, and the second air supply is moved by the moving support rather than by the cover. Sending the second drying wind on the downstream side in the direction,
The evacuation is performed between the step A and the step B.
Solution film formation method. A solution film forming method for manufacturing a film by drying a film formed on a moving support,
(D) sending a first drying wind from the first air supply port of the first drying unit until a dry layer is formed on the surface side of the film by evaporation of the solvent;
(E) promoting the evaporation of the solvent by impinging a second drying wind from the second drying unit on the surface of the membrane;
(F) blocking the first drying wind flowing toward the second air supply port between the step D and the step E; And,
(L) peeling the film after the step E from the moving support to a film;
And,
The membrane comprises a polymer and a solvent,
The first drying unit has a cover and the first air supply, the cover covers the membrane, and the first air supply is provided upstream of the moving direction of the moving support than the cover, and the first air supply is provided. Sends a first drying wind toward the cover and the membrane;
The second drying unit has a second air supply, the second air supply emits the second drying wind which is approximately vertical toward the surface of the membrane, and the second air supply is moved by the moving support rather than by the cover. To send out the second drying wind on the downstream side in the direction
Solution film formation method.

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