TW201313592A - Control device of moving direction of circular belt, casting apparatus, and solution casting method - Google Patents

Abstract

A circular casting belt is bridged over horizontal rollers. The horizontal roller is rotated by a motor. The casting belt moves in a circulating manner along a moving route formed on the horizontal rollers. A belt guiding mechanism has guide rollers for one end side of the casting belt, and guide rollers for the other end side of the casting belt. The guide rollers for one end side of the casting belt are disposed at one end side in a Y direction of the moving route located below. The guide rollers for the other end side of the casting belt are disposed at the other end side in the Y direction of the moving route located below.

Description

Moving direction control device for annular belt, casting device and solution film forming method

The present invention relates to a moving direction control device for an endless belt, a casting device, and a solution film forming method.

A translucent polymer film (hereinafter referred to as a film) is lightweight and easy to mold, and thus is widely used as an optical film. Among them, a cellulose ester film using a cellulose halide or the like is used as an optical film of a liquid crystal display device in addition to a film for photo-sensing. As the optical film of the liquid crystal display device, there are a polarizing plate protective film or a retardation film.

A film is produced by a solution film forming method. The solution film forming method is a method having the following processes. First, using a casting die disposed in a casting chamber, a polymer solution (hereinafter referred to as a dope) is discharged toward a support that has undergone temperature adjustment, and a tape cast film is formed on the support. (hereinafter referred to as a film formation process). The dope includes a polymer and a solvent. Next, the solvent is evaporated from the casting film until a cast film can be transferred (hereinafter referred to as a film drying process). Thereafter, the cast film which can be conveyed is peeled off from the support as a wet film (hereinafter referred to as a peeling process). Further, the solvent is evaporated from the wet film as a film (hereinafter referred to as a film drying process).

As a support for the solution forming method of the solution, an endless belt which is stretched over a plurality of rolls and circulated and moved is known. Since the film formation process, the film drying process, and the peeling process can be repeatedly performed by using the annular band, the production efficiency of the film can be improved as a result.

However, if the solution film forming method is carried out for a long period of time, it may cause a ring shape. The belt is offset from the predetermined annular path (annular moving path). When the solution film forming method is performed in a state where the endless belt is deviated from the annular path, the uniformity of the obtained film is impaired. Among the uniformity of the film, in particular, the thickness in the width direction, the surface state, and the uniformity of optical characteristics are impaired.

As a method of adjusting the moving direction of the endless belt, for example, it is known that the driving roller or the driven roller wound with the endless belt is moved as disclosed in Japanese Patent Laid-Open Publication No. 2002-254452 or Japanese Patent Laid-Open No. Hei 10-202722. Change the invention.

In the method of controlling the moving direction of the endless belt of the Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei 10-202722, the movement direction of the endless belt is caused by the following (1) to (3). The accuracy of the control is reduced. As a result, not only is the endless belt difficult to return to the annular path, but also the annular band is more deviated from the annular path.

(1) For the purpose of improving the production efficiency of the solution film forming method, the moving speed of the endless belt is increased.

(2) A case where a change in the moving speed of the endless belt occurs.

(3) The amount of change in the temperature of the endless belt during the film formation process, the film drying process, and the peeling process is repeated.

Thus, a moving direction control method capable of more reliably restricting a moving endless belt to an endless belt of an annular path is required.

An object of the present invention is to provide a ring-shaped belt that can be moved more reliably to the ring regardless of the magnitude of the moving speed of the endless belt, the fluctuation of the moving speed of the endless belt, and the amount of fluctuation in the temperature of the endless belt. Ring of the road Belt movement direction control device, casting device and solution film forming method.

The moving direction control device for the endless belt of the present invention is a moving direction control device that includes a guide mechanism and controls an endless belt in a moving direction of the endless belt. The endless belt is wound around a driving roller and a driven roller which are disposed horizontally and in parallel with each other, and are moved by the rotation of the driving roller. The guiding mechanism guides the end surface in the width direction of the endless belt. The guiding mechanism is disposed on both outer sides in the width direction of the lower portion of the annular moving path in which the endless belt moves.

It is preferable that the guiding mechanism is disposed to be movable between a position close to the moving path and a retracted position away from the approaching position. The guiding mechanism is preferably a guide roller having a roller body and a roller shaft. The roller body guides the end surface in the width direction of the endless belt on the circumferential surface. The roller shaft axially supports the roller body. It is further preferable to form a support groove for guiding the end surface in the width direction of the endless belt on the circumferential surface of the roller main body.

It is preferable that the guiding mechanism is biased toward the center side in the width direction of the moving path. The guiding mechanism is preferably a guide roller having a roller body and a roller shaft. The roller body guides the end surface in the width direction of the endless belt on the circumferential surface. The roller shaft axially supports the roller body. It is further preferable to form a support groove for guiding the end surface in the width direction of the endless belt on the circumferential surface of the roller main body.

The guiding mechanism is preferably provided with one end side guide and the other end side guide. The one end side guide is disposed on one end side in the width direction of the moving path. The other end side guide is disposed on the other end side in the width direction of the moving path. The one end side guide and the other end side guide are alternately arranged in the moving direction of the endless belt.

One end side guide and the other end side guide are arranged to follow the slave roll It is preferable that the cylinder approaches the drive roller and approaches the center portion in the width direction of the movement path.

The moving direction control device for the endless belt further preferably includes a driven roller shifting portion, an off-direction detecting portion, and a driven roller posture controlling portion. The driven roller shifting portion shifts the driven roller between the first posture and the second posture. The first posture is a posture in which one end of the driven roller is closer to the driving roller than the other end. The second posture is a posture in which the other end of the driven roller is closer to the driving roller than the one end. The deviation direction detecting unit detects the direction in which the endless belt deviates from the movement path. The driven drum posture control unit controls the driven drum shifting unit in accordance with the deviation direction detected by the deviation direction detecting unit.

The drive roller is preferably provided with a drive roller body and a drum drive shaft. The driving roller body supports the back surface of the endless belt by the circumferential surface. The drum drive shaft axially supports the drive drum body. The drive roller main body has a small-diameter roller portion provided at a central portion in the width direction and a large-diameter roller portion provided at both end portions in the width direction. The moving path is set on the circumferential surface of the small diameter roller portion.

The casting apparatus of the present invention is a casting apparatus which forms a film composed of a dope on an endless belt. The casting apparatus includes a casting die, a driving roller, a driven roller, an endless belt, a film drying device, a peeling device, and a moving direction control device. The casting die flows out of the dope. The dope includes a polymer and a solvent. The drive rollers are arranged horizontally. The driven roller is horizontally arranged. The driven roller is disposed in parallel with the drive roller. The endless belt is wound around the drive roller and the driven roller and is moved by the rotation of the drive roller. The endless belt has a support surface that supports the concentrated liquid flowing out of the casting die. The dope flows out from the casting die toward the portion of the endless belt wound around the drive roller. The film is formed on the support surface. Membrane drying device blows dry air to the membrane And evaporate the solvent from the membrane. The peeling device peels off the film from the endless belt. The moving direction control device controls the moving direction of the endless belt. The movement direction control device includes a guide mechanism that guides the end surface in the width direction of the endless belt. The guiding mechanism is disposed on both outer sides in the width direction of the lower portion of the annular moving path in which the endless belt moves.

The solution film forming method of the present invention is a film forming method of producing a film from a dope. The solution film forming method includes a film forming step, a film drying step, a peeling step, and a movement control step. The film forming step forms a film composed of a dope on the endless belt. The dope contains the polymer and solvent. The endless belt is wound around the drive roller and the driven roller and is moved by the rotation of the drive roller. The drive roller and the driven roller are disposed horizontally and in parallel with each other. The endless belt has a support surface that supports the concentrated liquid flowing out of the casting die. The dope flows out from the casting die toward the portion of the endless belt wound around the drive roller. The film drying step blows dry air to the film on the support surface and evaporates the solvent from the film. The stripping step strips the film of the film drying process from the endless belt. The movement control step controls the movement direction of the endless belt by the movement direction control means. The moving direction control device has a guiding mechanism that guides the end surface in the width direction of the endless belt. The guiding mechanism is disposed on both outer sides in the width direction of the lower portion of the annular moving path in which the endless belt moves.

According to the present invention, regardless of the magnitude of the moving speed of the endless belt, the fluctuation of the moving speed of the endless belt, the amount of fluctuation in the temperature of the endless belt, or the like, the moving endless belt can be more reliably restricted to the annular passage.

(solution film making equipment)

As shown in FIG. 1, the solution film forming apparatus 10 has a casting device 15, a clip tenter 17, a drying device 18, and a winding device 19. Casting device 15 The wet film 13 is made of the dope 12. The clip tenter 17 obtains the film 16 by drying the wet film 13. Drying device 18 further dries film 16. The take-up device 19 winds the film 16 onto the core.

(casting device)

As shown in FIG. 2, the casting apparatus 15 has a casing 23 and a casting apparatus main body disposed in the casing 23. The casting device main body has a casting support unit, a separator unit, a casting unit, a film drying unit, and a peeling member.

(casting support unit)

The casting support unit includes: a horizontal drum 24 and a horizontal drum 25 which are horizontally and parallel to each other in the casing 23; the casting belt 26 is mounted on the horizontal drum 24, the horizontal drum 25, and the belt moving unit 27 ( See Figure 3, Figure 4).

As shown in FIG. 3, the horizontal drum 24 is provided with a drive shaft 24A, a stainless steel drum main body 24B fixed to the drive shaft 24A, and a bearing (not shown) of the drive shaft. The horizontal drum 25 includes a rotating shaft 25A, a stainless steel drum main body 25B fixed to the rotating shaft 25A, and a bearing 25AS provided at both ends of the rotating shaft 25A. The annular casting belt 26 is wound around the horizontal drum 24 and the horizontal drum 25. The casting tape 26 is obtained by joining both ends of the strip-shaped sheet.

Here, the horizontal means that the angle of intersection of the horizontal drum 24 and the horizontal drum 25 with respect to the horizontal plane is 0° or more and 0.05° or less, respectively. Further, the parallel means that the intersection angle of the horizontal drum 24 and the horizontal drum 25 is 0° or more and 0.05° or less.

The casting tape 26 is preferably made of stainless steel (for example, SUS316) having sufficient corrosion resistance and strength. The width of the casting belt 26 is, for example, a dope 12 It is preferable that the casting width is 1.1 times or more and 2.0 times or less. The length of the casting belt 26 is preferably 20 m or more and 200 m or less, for example. The thickness of the casting belt 26 is preferably 0.5 mm or more to 2.5 mm or less. Further, it is preferable that the thickness of the casting tape 26 is not uniform, and the thickness is 0.5% or less with respect to the entire thickness. Further, a surface (hereinafter referred to as a casting surface) 26A on which the casting film is formed and a back surface 26B which is in contact with the drum main body 24B and the drum main body 25B are formed flat. In particular, the casting surface 26A is preferably polished, and the surface roughness of the casting surface 26A is preferably 0.05 μm or less.

As shown in FIGS. 3 and 4, the belt moving unit 27 includes a belt moving portion 28 for moving the casting belt 26 wound around the horizontal drum 24 and the horizontal drum 25, and a belt moving direction control for restricting the moving direction of the casting belt 26. The unit 29 and the control unit 30.

The belt moving unit 28 includes a drive motor 28M, a shaft displacement unit 28AS, and a force sensor 28LC.

The drive motor 28M is connected to the drive shaft 24A. The control unit 30 controls the drive motor 28M to rotate the drum main body 24B at a predetermined speed. The casting belt 26 is cyclically moved in a predetermined direction as the drum main body 24B rotates, and the drum main body 25B rotates as the casting belt 26 moves. Hereinafter, the moving direction of the casting tape 26 is referred to as the X direction, the width direction of the casting tape 26 is referred to as the Y direction, and the vertical direction is referred to as the Z direction.

The moving speed V _26A of the casting surface 26A of the casting belt 26 is preferably 150 m/min or less. If the moving speed V _26A exceeds 150 m/min, it is difficult to stably form the bead. Regarding the lower limit of the moving speed V _26A , the productivity of the target film may be considered. The lower limit of the moving speed V _26A is, for example, 10 m/min.

The drive shaft 24A is freely movable between a tension applied position and a relaxed position. The tension applied position is a position at which a predetermined moving tension is applied to the casting belt 26 which is mounted on the drum main body 24B and the drum main body 25B. The slack position is a position where the casting belt 26 that is stretched over the drum main body 24B and the drum main body 25B is slack. The shaft displacement portion 28AS shifts the drive shaft 24A between the tension applied position and the slack position under the control of the control unit 30. The shaft displacement portion 28AS preferably moves the drive shaft 24A while maintaining the state parallel to the rotation shaft 25A.

The force sensor 28LC is mounted to the drive shaft 24A. The force sensor 28LC detects the external force that the drive shaft 24A is subjected to. The control unit 30 reads the force received by the drive shaft 24A from the force sensor 28LC. Next, the control unit 30 controls the shaft displacement portion 28AS in accordance with the external force of reading and the cross-sectional area value of the built-in casting tape 26 so that the moving tension applied to the casting tape 26 becomes a predetermined one. In this way, the same moving tension can be applied to the casting belt 26 in the Y direction.

(with moving direction control unit)

The belt movement direction control unit 29 has a drum swing mechanism 35 and a belt guide mechanism 36. The drum swinging mechanism 35 swings the horizontal drum 25 in a direction in which the casting belt 26 is displaced from the moving path 26R. The tape guiding mechanism 36 guides both end faces of the casting tape 26 in the Y direction.

(roller swing mechanism)

The drum swinging mechanism 35 is provided with an offset detecting portion 35K and a bearing displacement portion 35S. The deviation detecting portion 35K senses that the casting tape 26 has deviated from the moving path 26R. The bearing displacement portion 35S moves the pair of bearings 25AS independently in the X direction.

The deviation detecting unit 35K is provided in the drying chamber 23B. The deviation detecting unit 35K includes one end deviation detecting unit 35KP provided on one end side of the casting belt 26 and the other end detecting unit 35KQ provided on the other end side of the casting belt 26.

As shown in FIG. 5, the one end deviation detecting portion 35KP includes a light emitting portion 40PA and a light receiving portion 40PB. The light emitting unit 40PA has a built-in light source and emits inspection light from the light source to the outside. The light receiving unit 40PB incorporates a photosensor capable of receiving the inspection light, and the photo sensor determines whether or not the inspection light from the light emitting unit 40PA has been detected. When the light receiving unit 40PB senses the inspection light, the light receiving unit 40PB outputs a detection signal. The light-emitting portion 40PA and the light-receiving portion 40PB are provided so that the optical path 40PX of the inspection light from the light-emitting portion 40PA to the light-receiving portion 40PB passes through one end of the movement path 26R of the casting tape 26 set in advance in the Y direction.

The other end deviation detecting unit 35KQ includes the light emitting unit 40QA and the light receiving unit 40QB in the same manner as the one end deviation detecting unit 35KP. The light-emitting unit 40QA has a built-in light source and emits inspection light from the light source to the outside. The light receiving unit 40QB incorporates a photo sensor capable of receiving the inspection light, and the photo sensor determines whether or not the inspection light from the light emitting unit 40QA has been detected. When the light receiving unit 40QB detects the inspection light, the light receiving unit 40QB outputs a detection signal. The light-emitting unit 40QA and the light-receiving unit 40QB are provided so that the optical path 40QX of the inspection light from the light-emitting unit 40QA to the light-receiving unit 40QB passes through the other end of the movement path 26R of the casting belt 26 set in advance in the Y direction.

The movement path 26R is a reference path which is set in advance in the Y direction and is wound around the casting belt 26 of the horizontal drum 24 and the horizontal drum 25, and is formed in a ring shape. The width of the moving path 26R is the width of the casting tape 26 plus a predetermined clearance width. Degree.

Referring back to FIG. 3 and FIG. 4, the bearing displacement portion 35S includes one end side bearing displacement portion 35SP for moving the one end side bearing 25AS and the other end side bearing displacement portion 35SQ for moving the other end side bearing 25AS. The one end side bearing displacement portion 35SP and the other end side bearing displacement portion 35SQ independently move the bearing 25AS in a predetermined direction under the control of the control unit 30.

The control unit 30 performs a deviation direction determination process. In the deviation direction determination processing, first, the control unit 30 determines whether or not the detection signal is output from the light receiving unit 40PB and the light receiving unit 40QB (see FIG. 5). When it is determined that the detection signals are output from both the light receiving unit 40PB and the light receiving unit 40QB (see FIG. 5), the control unit 30 determines that the casting tape 26 is on the movement path 26R. On the other hand, when it is determined that the detection signal is output from the light receiving unit 40QB (see FIG. 5) and the detection signal is not output from the light receiving unit 40PB (see FIG. 5), the control unit 30 determines that the casting tape 26 is from the movement path 26R to the one end side. Deviation. When it is determined that the detection signal is output from the light receiving unit 40PB (see FIG. 5) and the detection signal is not output from the light receiving unit 40QB (see FIG. 5), the control unit 30 determines that the casting tape 26 is deviated from the movement path 26R toward the other end side. .

Further, the control unit 30 performs a slave drum shifting process for adjusting the posture of the horizontal drum 25 in accordance with the result of the deviation direction determining process. In the driven drum shifting process, the control unit 30 controls the bearing displacement portion 35S in accordance with the result of the deviation direction determining process. For example, when it is determined that the casting belt 26 is in the moving path 26R, the control unit 30 controls the one end side bearing displacement portion 35SP and the other end side bearing displacement portion 35SQ such that the rotation shaft 25A is parallel to the drive shaft 24A. The position parallel to the drive shaft 24A is set as the reference position (see the figure). 6). On the other hand, when it is determined that the casting belt 26 is displaced from the movement path 26R toward the one end side, the one end side bearing displacement portion 35SP and the one end side of the rotation shaft 25A are further away from the drive shaft 24A than the other end side of the rotation shaft 25A. The other end side bearing displacement portion 35SQ (see Fig. 7). On the other hand, when it is judged that the casting belt 26 is displaced from the moving path 26R to the other end side, the one end side bearing displacement portion 35SP and the other are controlled such that the other end side of the rotating shaft 25A is farther from the driving shaft 24A than the one end side of the rotating shaft 25A. One end side bearing displacement portion 35SQ (see Fig. 8).

(with guiding mechanism)

As shown in FIGS. 9 and 10, the tape guiding mechanism 36 is disposed on both outer sides in the Y direction of the moving path 26R. The tape guiding mechanism 36 has one end side guide rollers 36PA to 36PB and the other end side guide rollers 36QA to 36QC. The one end side guide rollers 36PA to 36PB are one end side guides disposed on one end side in the Y direction of the lower portion of the movement path 26R. The other end side guide rollers 36QA to 36QC are the other end side guides disposed on the other end side in the Y direction of the lower portion of the movement path 26R. Here, the lower portion of the moving path 26R refers to the casting belt 26 and the drum main body 24B which are moved from the position P25 (refer to FIG. 2) of the casting belt 26 wound around the drum main body 25B away from the drum main body 25B to the drum main body 24B. Contact position P24 (see Figure 2). The one end side guide roller 36PA and the one end side guide roller 36PB are disposed in order from the upstream side in the X direction toward the downstream side. In the same manner, the other end side guide roller 36QA, the other end side guide roller 36QB, and the other end side guide roller 36QC are disposed in order from the upstream side in the X direction toward the downstream side.

Moreover, each of the guide rollers 36PA~36PB and each guide roller 36QA~36QC It is preferable to alternately arrange in the X direction. Thereby, the casting belt 26 can be guided so as to be limited to the movement path 26R while minimizing the force applied to the casting belt 26.

As shown in FIGS. 10 and 11, the other end side guide roller 36QA is provided with a guide roller main body 51 and a guide roller shaft 52. The guide roller main body 51 guides the belt end surface 26E of the casting belt 26 in the Y direction on the circumferential surface 51S. The guide roller shaft 52 axially supports the guide roller main body 51. The guide roller shaft 52 extends in the Z direction. The circumferential surface of the guide roller main body 51 or the guide roller main body 51 is preferably formed of a material such as Teflon (registered trademark). It is preferable that the support groove 51D for guiding the belt end surface 26E of the casting belt 26 in the Y direction is formed on the circumferential surface 51S of the guide roller main body 51. The support groove 51D is extended in the circumferential direction and formed in a ring shape. The support groove 51D includes a bottom surface 51DD and a side surface 51DS that guide the belt end surface 26E of the casting belt 26 in the Y direction.

Further, the other end side guide roller 36QA may include a swing shaft 55 disposed in parallel with the guide roller shaft 52, and a coupling arm 56 that connects the guide roller shaft 52 and the swing shaft 55. One end of the connecting arm 56 is fixed to the guide roller shaft 52, and the other end is axially supported by the swing shaft 55. The guide roller main body 51 is swingable between the approaching position P1 in the moving path 26R and the retracted position P2 to P3 which is retracted from the approaching position P1 by the connecting arm 56 (see FIG. 12). The retracted position P2 is on the upstream side in the X direction from the approach position P1, and the retracted position P3 is on the downstream side in the X direction from the approach position P1. The casting belt 26 can be guided by the swing shaft 55 and the connecting arm 56 to minimize the force applied to the casting belt 26 while being restricted to the inside of the moving path 26R. In addition, it can be set to be close to the position P1 The ejector main body 51 performs a biasing force applying member.

Further, the other end side guide roller 36QA may have a shaft displacement portion 61 (see FIGS. 9 and 10) or a spring 62 (see FIG. 11). The shaft displacement portion 61 moves the swing shaft 55 in the Z direction. The spring 62 biases the guide roller main body 51 toward the center side in the Y direction. The control unit 30 controls the shaft displacement portion 61 so that the guide roller main body 51 is positioned to support the belt end surface 26E of the casting belt 26 in the Y direction by the circumferential surface 51S (see FIG. 4). The control unit 30 preferably controls the shaft displacement portion 61 so as to prevent the casting tape 26 from coming into contact with the side surface 51DS. In the spring 62, for example, one end is fixed to the swing shaft 55, and the other end is fixed to the inner wall surface 23S of the casing 23. The force applied to the casting tape 26 can be minimized by the spring 62, and the casting tape 26 can be guided to be restricted to the inside of the moving path 26R.

In addition, since the one end side guide rollers 36PA to 36PB and the other end side guide rollers 36QB to 36QC have the same configuration as the other end side guide roller 36QA, detailed description thereof will be omitted.

Regardless of whether the guide roller main body 51 is disposed on one end side or is disposed on the other end side, the bottom surface 51DD of the support groove 51D of the guide roller main body 51 at the position P1 and the Y-direction end portion of the movement path 26R are not provided. The interval CL of the 26RE (see FIG. 11) is preferably decreased as it goes from the upstream side toward the downstream side in the X direction. Further, the interval CL (see FIG. 11) is, for example, 0 mm or more and 20 mm or less. For example, the interval CL _QA of the other end side guide roller 36QA shown in Fig. 9, the interval CL _PA with respect to the one end side guide roller 36PA, the interval CL _QB with respect to the other end side guide roller 36QB, and the one end side guide roller It is preferable that the interval CL _{PB of} 36 _PB and the interval CL _QC of the other end side guide roller 36QC satisfy the relational expression (1).

CL _QA >CL _PA >CL _QB >CL _PB >CL _QC .........Relationship (1)

(separator unit)

Referring back to FIG. 2 , the separator unit includes the first to third sealing members 71 to 73 . The first to third sealing members 71 to 73 are disposed in the casing 23 from the upstream side in the X direction toward the downstream side. Each of the first to third sealing members 71 to 73 is provided so as to protrude from the inner wall surface of the casing 23, and the projecting end is close to the casting surface 26A of the casting belt 26. In the casing 23, the section surrounded by the inner wall surface of the casing 23 and the casting surface 26A is separated into a casting chamber 23A from the upstream side toward the downstream side in the X direction by the first to third sealing members 71 to 73, Drying chamber 23B and peeling chamber 23C. Further, the airtightness of the casting chamber 23A is maintained by the first sealing member 71 to the second sealing member 72. Further, the airtightness of the drying chamber 23B is maintained by the second sealing member 72 to the third sealing member 73. The distance between the first sealing member 71 to the third sealing member 73 and the casting surface 26A is, for example, 1.5 mm or more and 2.0 mm or less.

(casting unit)

A casting unit that forms the casting film 76 from the dope 12 (see FIG. 1) is disposed in the casting chamber 23A. The casting unit includes a casting die 77 and a pressure reducing machine 78. The casting die 77 has a dope outflow port 77A that flows out of the dope 12 (see Fig. 1). The casting die 77 is disposed above the horizontal drum 24 so that the portion of the casting belt 26 wound around the drum main body 24B is close to the dope outlet 77A.

The casting die 77 flows out of the dope 12 from the dope outlet 77A toward the casting belt 26 (see Fig. 1). The dope 12 (see FIG. 1) which flows out from the dope outlet 77A and reaches the casting surface 26A forms a bead. Reaching the casting surface 26A The dope 12 is cast in the X direction to form a strip-shaped cast film 76.

The pressure reducer 78 is for decompressing the upstream side of the liquid droplet in the X direction. The pressure reducer 78 has a decompression chamber 78A, a decompression fan 78B, and a suction pipe 78C. The decompression chamber 78A is disposed on the upstream side in the X direction from the dope outlet 77A of the casting die 77. The decompression fan 78B is used to attract the gas in the decompression chamber 78A. The suction pipe 78C is connected to the pressure reducing fan 78B and the decompression chamber 78A.

(film drying unit)

A film drying unit that performs drying of the cast film is disposed in the drying chamber 23B. The film drying unit includes a first dryer 81 to a second dryer 82 and a drying controller (not shown) that supply predetermined drying air to the casting film 76. The first dryer 81 to the second dryer 82 are disposed in order from the upstream side in the X direction toward the downstream side in the drying chamber 23B. The first dryer 81 is disposed above the casting belt 26 that is stretched over the horizontal drum 24 and the horizontal drum 25. The second dryer 82 is disposed below the casting belt 26 that is stretched over the horizontal drum 24 and the horizontal drum 25.

The first dryer 81 includes a first intake duct 81A and a first exhaust duct 81B. The first intake duct 81A and the first exhaust duct 81B are disposed in order from the upstream side in the X direction toward the downstream side. The first intake duct 81A and the first exhaust duct 81B are disposed apart from the casting belt 26, respectively. The first intake port 81A that sends out the first dry air 81DA is provided in the first intake duct 81A. The first intake port 81AO that opens toward the downstream side in the X direction extends from one end of the cast film 76 to the other end. The first exhaust port 81B that discharges the first dry air 81DA is provided in the first exhaust duct 81B. The first exhaust port 81BO that opens toward the upstream side in the X direction extends from one end of the casting film 76 to the other end.

The second dryer 82 includes a second exhaust duct 82A and a second intake duct 82B. The second exhaust duct 82A and the second intake duct 82B are provided in order from the upstream side in the X direction toward the downstream side. The second exhaust duct 82A and the second intake duct 82B are disposed apart from the casting belt 26, respectively. The second exhaust duct 82A is provided with a second exhaust port 82AO through which the second dry air 82DA is discharged. The second exhaust port 82AO that opens toward the downstream side in the X direction extends from one end of the casting film 76 to the other end. The second intake port 82BO that sends out the second dry air 82DA is provided in the second intake duct 82B. The second intake port 82BO that opens toward the upstream side in the X direction extends from one end of the cast film 76 to the other end.

The drying controller independently adjusts the temperature or wind speed of the first dry air 81DA and the second dry air 82DA. The first control fan to the second temperature control unit (not shown) and the first to fourth air fans (not shown) that adjust the air volume of the first dry air 81DA and the second dry air 82DA are provided. And controller (not shown). The first temperature control machine to the second temperature control unit adjust the temperatures of the first dry air 81DA and the second dry air 82DA. The first thermostat to the second thermostat and the first to second fan are provided in the respective ducts of the first dryer 81 to the second dryer 82. The controller controls the first temperature control unit to the second temperature control unit and the first to second power supply fans, and independently adjusts the temperature or the wind speed of the first dry air 81DA and the second dry air 82DA.

(peeling member)

A peeling roller 86 as a peeling member is disposed in the peeling chamber 23C. The peeling roller 86 peels the cast film 76 which has been peeled off from the casting tape 26 as the wet film 13, and feeds the wet film 13 from the outlet 23CO provided in the peeling chamber 23C.

A condensing device that condenses the solvent contained in the atmosphere in the casing 23 and a recovery device that recovers the condensed solvent can be placed in the casting device 15. Thereby, the concentration of the solvent contained in the atmosphere in the casing 23 can be maintained within a constant range.

Returning to Fig. 1, a plurality of support rollers 87 for supporting the wet film 13 are arranged on the transfer portion between the casting device 15 and the clip tenter 17. The support roller 87 rotates around the shaft by a motor (not shown). The support roller 87 supports the wet film 13 fed from the casting device 15 and is guided to the clip tenter 17. In addition, FIG. 1 shows a case where two support rollers 87 are arranged in the transfer portion. However, the present invention is not limited thereto, and one or three or more support rollers 87 may be arranged in the transfer portion. Also, the support roller 87 may be a free roller.

The clip tenter 17 has a plurality of clips that grip the two side edge portions of the wet film 13 in the width direction, and the clip moves on the stretching rail. The wet film 13 is sent to the dry air with respect to the wet film 13 held by the clip, and the wet film 13 is subjected to stretching treatment and drying treatment in the width direction.

A trimming device 88 is disposed between the clip tenter 17 and the drying device 18. Both ends of the film 16 sent out of the trimming device 88 in the amplitude direction are formed with gripping traces formed by the clips. The trimming device 88 cuts off the ends having the grip marks. The cut portion is sent to the cutting fan (not shown) and the crusher (not shown) in order, and is shredded and reused as a raw material such as a dope.

The drying device 18 includes a casing, a plurality of rollers 18A, and an air conditioner (not shown). The housing is provided with a conveying path of the film 16. A plurality of rollers 18A form a transport path for the film 16. The air conditioner performs temperature or humidity on the atmosphere inside the casing Adjustment. The film 16 introduced into the casing is wound while being wound around a plurality of rolls 18A. The residual solvent is evaporated from the film 16 conveyed in the casing by adjusting the temperature or humidity of the atmosphere. Further, the drying device 18 is connected to an adsorption recovery device that recovers the solvent evaporated from the film 16 by adsorption.

A cooling chamber 89, a static eliminating rod (not shown), a knurled roller 90, and a trimming device (not shown) are disposed between the drying device 18 and the winding device 19 in this order from the upstream side. The film 16 is cooled by the cooling chamber 89 until the temperature of the film 16 becomes substantially room temperature. The static eliminating rod performs a static elimination treatment of the thin film 16 which is sent out from the cooling chamber 89 and charged. The roller 90 with knurling imparts a knurling for winding to both ends in the width direction of the film 16. The trimming device cuts both ends in the width direction of the film 16 so that knurls remain at both ends in the width direction of the cut film 16 .

The take-up device 19 has a pressure roller 19A and a winding core 19B. The film 16 fed to the take-up device 19 is wound in the roll core 19B while being pressed by the press roller 19A to be in a roll shape.

Next, the action of the present invention will be described. As shown in FIGS. 3 and 4, a predetermined movement tension is applied to the casting belt 26 by the shaft displacement portion 28AS, the force sensor 28LC, and the control portion 30. Then, the horizontal roller 24 is rotated by the drive motor 28M and the control unit 30. Thereby, the casting belt 26 moves on the movement path 26R, that is, the movement path 26R in the casing 23 sequentially circulates in each of the chambers 23A to 23C.

(film formation process)

As shown in FIG. 2, in the casting chamber 23A, a casting process in which the casting film 76 composed of the dope 12 is formed on the casting tape 26 is performed. Casting die 77 from the dope The outflow port 40A continuously flows out of the dope 12. The concentrated dope 12 flows from the casting die 77 over the casting tape 26 to form a bead, and is cast on the casting tape 26. Thus, a casting film 76 composed of the dope 12 is formed on the casting belt 26.

(film drying process)

In the drying chamber 23B, a film drying process in which a predetermined dry air is blown to the casting film 76 and the solvent is evaporated from the casting film 76 is performed. The film drying process proceeds to a state in which the casting film 76 can be independently transferred. In the film drying process, the first film drying process of blowing the first dry air 81DA to the casting film 76 and the second film drying process of blowing the second drying wind 82DA to the casting film 76 are sequentially performed.

The casting film 76 in which the content of the first film drying process is 250% by mass or more and 400% by mass or less, and the content of the solvent is preferably 300% by mass or more and 350% by mass or less. It is better to do it. The temperature of the first dry air 81DA is preferably 30° C. or higher and 80° C. or lower. Further, the wind speed of the first dry air 81DA is preferably 5 m/sec or more and 25 m/sec or less.

In the second film drying process, the temperature of the second dry air 82DA is preferably 30° C. or higher and 80° C. or lower. Further, the wind speed of the second dry air 82DA is preferably 5 m/sec or more and 25 m/sec or less.

In addition, the content rate of the solvent is the amount of the solvent contained in the casting film or each film on a dry basis, and when the sample is taken from the target film, the weight of the sample is x, and the weight after drying the sample is set. When y, it is expressed as {(xy)/y}×100.

(peeling process)

In the peeling chamber 23C, peeling from the casting tape 26 is performed to be peelable The stripping process of the cast film 76 from the state. The peeling roller 86 is peeled from the casting tape 26 into a peelable state of the casting film 76 as the wet film 13, and the wet film 13 is sent out from the outlet 23CO provided in the peeling chamber 23C. It is preferable that the casting film 76 having a content of the peeling process to the solvent is 20% by mass or more and 80% by mass or less.

Further, after the stripping process, the film forming process is again performed on the casting tape 26. In this manner, the film forming process, the film drying process, and the peeling process are repeatedly performed in the casting device 15. The wet film 13 can be continuously produced from the dope 12 by the casting device 15.

When the control unit 30 detects that the casting belt 26 is displaced from the movement path 26R, the control unit 30 controls the slave drum shifting process of the bearing displacement portion 35S according to the result of the deviation direction determination processing (see FIGS. 6 to 8). ). The casting belt 26 can be returned to the moving path 26R by the driven drum shifting process. However, when the moving speed of the casting belt 26 is large (for example, 50 m/min or more) or the moving speed of the casting belt 26 is largely changed (for example, 2 m/min ² or more) or the film forming process is repeated, When the amount of fluctuation in the temperature of the casting belt 26 during the film drying process and the peeling process is large (for example, 30 ° C or higher), it is difficult to return the casting tape 26 to the moving path 26R only by the deviation direction determining process, and The casting belt 26 is further offset from the moving path 26R.

The casting device 15 can maintain the casting tape 26 in the casting device 15 within the range of the width of the moving path 26R plus the amount of constant play by the tape guiding mechanism 36. Therefore, it is possible to prevent the casting belt 26 from largely deviating from the moving path 26R. Moreover, the shifting of the casting belt 26 can be avoided by performing the driven drum shifting process in such a state. Drive 26R. In this manner, the dope 12 (see FIG. 1) flowing out from the casting die 77 can be placed at the casting position CP (see FIG. 8) of the casting surface 26A, and the casting tape 26 can be restricted to the moving path 26R.

The drum swinging mechanism 35 can be omitted. When the drum swing mechanism 35 is omitted, the interval CL between the bottom surface 51DD and the Y-direction end portion 26RE of the movement path 26R may be set to 0 (see FIG. 13).

When the drum swing mechanism 35 (see FIG. 4) is utilized, the guide roller closest to the horizontal drum 25 needs to be away from the horizontal drum 25 to such an extent that it does not come into contact with the swinging horizontal drum 25. However, when the drum swing mechanism 35 is omitted, the guide roller closest to the horizontal drum 25 can be brought closer to the horizontal drum 25.

Further, instead of the horizontal drum 24, the stepped drum 124 shown in Figs. 14 and 15 can be used. The stepped drum 124 is disposed horizontally in the casing 23 in parallel with the horizontal drum 25, and includes a drive shaft 124A and a stainless steel drum main body 124B fixed to the drive shaft 124A. The drum main body 124B includes a small-diameter roller portion 124BC at a central portion in the Y direction, and a large-diameter roller portion 124BE at both end portions in the Y direction. The length of the small diameter roller portion 124BC in the Y direction is equal to the width of the movement path 26R. The movement path 26R is set on the circumferential surface of the small diameter roller portion 124BC. The depth D _124M of the support groove 124M of the casting tape 26 formed by the large diameter roller portion 124BE and the small diameter roller portion 124BC, that is, the difference between the radius of the large diameter roller portion 124BE and the radius of the small diameter roller portion 124BC is The casting tape 26 wound around the circumferential surface of the small-diameter roller portion 124BC may not extend to the extent of the large-diameter roller portion 124BE, and may be, for example, 0.5 times or more and 5 times or less the thickness D ₂₆ of the casting tape 26. . The casting tape 26 can be prevented from deviating from the moving path 26R by the stepped roller 124.

When the stepped drum 124 is used, the drum swinging mechanism 35 or the belt guiding mechanism 36 can be omitted.

The film 16 obtained by the present invention can be used particularly for a retardation film or a polarizing plate protective film.

The width of the film 16 is preferably 600 mm or more, and more preferably 1400 mm or more and 2500 mm or less. Further, the present invention also has an effect when the width of the film 16 is more than 2,500 mm. Further, the film thickness of the film 16 is preferably 20 μm or more and 80 μm or less.

Further, the in-plane retardation Re of the film 16 is preferably 20 nm or more and 300 nm or less, and the film thickness retardation Rth of the film 16 is preferably -100 nm or more and 300 nm or less.

The method of measuring the in-plane retardation Re is as follows. For the in-plane retardation Re, the sample film was conditioned for 2 hours at a temperature of 25 ° C and a humidity of 60% RH, and was measured from the vertical direction at 632.8 nm by an automatic birefringence meter (manufactured by KOBRA 21 DH Prince Metering Co., Ltd.). Delay value. In addition, 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 phase axis 2, and d represents the thickness (film thickness) of the film.

The method of measuring the thickness direction retardation Rth is as follows. The sample film was conditioned for 2 hours at a temperature of 25 ° C and a humidity of 60% RH, and the value measured from the vertical direction at 632.8 nm and the film surface were inclined by the ellipsometer (M150, manufactured by JASCO Corporation). The extrapolated value of the measured delay value is calculated according to the following formula.

Rth={(n1+n2)/2-n3}×d

N3 represents the refractive index in the thickness direction.

(polymer)

In the above embodiment, the polymer which is a raw material of the polymer film is not particularly limited, and examples thereof include cellulose halides and cyclic polyolefins.

(cellulose cellulose)

The thiol group used for the cellulose oxime of the present invention may be used alone or in combination of two or more kinds. When two or more kinds of mercapto groups are used, one of them is preferably an ethylidene group. The ratio of the esterification of the hydroxyl group of the cellulose with a carboxylic acid, that is, the degree of substitution of the thiol group, satisfies all of the following formulas (I) to (III). Further, in the following formulas (I) to (III), A and B represent the degree of substitution of a mercapto group, A is a degree of substitution of an ethylidene group, and B is a degree of substitution of a mercapto group having 3 to 22 carbon atoms. Further, it is preferred that 90% by mass or more of triacetylcellulose (TAC) is 0.1 mm to 4 mm.

The total substitution degree A+B of the fluorenyl group is preferably 2.20 or more and 2.90 or less, and more preferably 2.40 or more and 2.88 or less. Further, the substitution degree B of the fluorenyl group having 3 to 22 carbon atoms is more preferably 0.30 or more, and particularly preferably 0.5 or more.

The cellulose which is a raw material of the cellulose oxime may be obtained from any one of cotton linters and pulp.

The fluorenyl group having a carbon number of 2 or more as the cellulose halide of the present invention It may be an aliphatic group or an aryl group, and is not particularly limited. These may be, for example, an alkylcarbonyl ester of cellulose, an olefinic carbonyl ester or an aromatic carbonyl ester, an aromatic alkylcarbonyl ester or the like, and may each have a further substituted group. As such a preferable example, a propyl fluorenyl group, a butyl fluorenyl group, a pentyl fluorenyl group, a hexyl fluorenyl group, a octyl decyl group, a decyl group, a dodecyl fluorenyl group, a tridecyl fluorenyl group, a tetradecyl fluorenyl group, and a hexadecane Anthracenyl, octadecylfluorenyl, isobutylhydrazine, tert-butylhydrazine, cyclohexanecarbonylcarbonyl, anthracenyl, benzamyl, naphthalenecarbonyl and cinnamyl. Among them, propyl sulfonyl, butyl fluorenyl, dodecyl fluorenyl, octadecyl fluorenyl, tert-butyl fluorenyl, anthracenyl, benzhydryl, naphthalenecarbonyl and cinnamyl are preferred, and propyl sulfhydryl and butyl sulfhydryl are particularly preferred. .

(solvent)

Examples of the solvent for preparing the dope include aromatic hydrocarbons (for example, benzene and toluene), halogenated hydrocarbons (for example, dichloromethane and chlorobenzene, etc.), and alcohols (for example, methanol, ethanol, n-propanol, and positive). Butanol and diethylene glycol, etc., ketones (for example, acetone and methyl ethyl ketone), esters (for example, methyl acetate, ethyl acetate, and propyl acetate) and ethers (for example, tetrahydrofuran and methyl cellosolve, etc.) Wait. Further, in the present invention, the dope refers to a polymer solution and a dispersion obtained by dissolving or dispersing a polymer in a solvent.

Among them, a halogenated hydrocarbon having 1 to 7 carbon atoms is preferably used, and dichloromethane is most preferred. From the viewpoint of physical properties such as the solubility of the polymer, the peelability of the cast film from the support, the mechanical strength of the film, and the optical properties of the film, one or several kinds of carbon atoms are mixed in addition to methylene chloride. The alcohol is preferred. The content of the alcohol is preferably 2% by mass to 25% by mass based on the total amount of the solvent, and more preferably 5% by mass to 20% by mass. Specific as alcohol Examples thereof include methanol, ethanol, n-propanol, isopropanol, n-butanol and the like, but methanol, ethanol, n-butanol or a mixture thereof is preferred.

However, in order to minimize the influence on the environment, the solvent composition in the case where methylene chloride is not used has been reviewed recently. For this purpose, an ether having 4 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms, an ester having 3 to 12 carbon atoms, or an alcohol having 1 to 12 carbon atoms is preferred. Sometimes mix these to use. For example, a mixed solvent of methyl acetate, acetone, ethanol, and n-butanol can be mentioned. These ethers, ketones, esters and alcohols may be those having a cyclic structure. Further, a compound having two or more functional groups of an ether, a ketone, an ester, and an alcohol (that is, -O-, -CO-, -COO-, and -OH) can also be used as a solvent.

Further, the details of the cellulose halide are described in paragraphs [0140] to [0195] of Japanese Patent Laid-Open Publication No. 2005-104148. These descriptions can also be applied to the present invention. Also, in the paragraphs [0196] to [0516] of Japanese Patent Laid-Open Publication No. 2005-104148, solvents and plasticizers, deterioration inhibitors, ultraviolet absorbers (UV agents), optical anisotropy control agents, and delays are also used. Additives such as inhibitors, dyes, matting agents, release agents, and release accelerators are described in detail.

10‧‧‧solution film making equipment

12‧‧‧Liquor

13‧‧‧ Wet film

15‧‧‧casting device

16‧‧‧Dry film

17‧‧‧Clip tenter

18‧‧‧Drying device

18A‧‧‧roll

19‧‧‧Winding device

19A‧‧‧Pressure roller

19B‧‧‧core

23‧‧‧ housing

23A‧‧‧Casting room

23B‧‧·drying room

23C‧‧‧ peeling room

23CO‧‧‧Export

23S‧‧‧ inner wall

24, 25‧‧‧ horizontal drum

24A, 124A‧‧‧ drive shaft

24B, 25B, 124B‧‧‧ Stainless steel drum body

25A‧‧‧Rotary axis

25AS‧‧‧ bearing

26‧‧‧Casting zone

26A‧‧‧Running surface

26B‧‧‧Back

26E‧‧‧with end face

26R‧‧‧Mobile Road

26RE‧‧‧Y-direction end of mobile road 26R

27‧‧‧With mobile unit

28‧‧‧With the Ministry of Movement

28AS‧‧‧Axis displacement

28LC‧‧‧Power Sensor

28M‧‧‧Drive motor

29‧‧‧With movement direction control

30‧‧‧Control Department

35‧‧‧Rolling mechanism

35K‧‧‧ Deviation Detection Department

35KP‧‧‧ one end deviation detection department

35KQ‧‧‧The other end of the deviation detection department

35S‧‧‧ bearing displacement

35SP‧‧‧ one end side bearing displacement

35SQ‧‧‧Other end side bearing displacement

36‧‧‧With guiding mechanism

36PA, 36PB‧‧‧ one end side guide roller

36QA, 36QB, 36QC‧‧‧ other end side guide rolls

40PA, 40QA‧‧‧Lighting Department

40PB, 40QB‧‧‧Receiving Department

40PX, 40QX‧‧‧ light path

51‧‧‧ Guide roller body

51D‧‧‧Support slot

51DD‧‧‧ bottom surface

51DS‧‧‧ side

51S‧‧‧Sun

52‧‧‧ Guide roller

55‧‧‧Swing axis

56‧‧‧Link arm

61‧‧‧Axis displacement

62‧‧‧ Spring

71‧‧‧1st sealing member

72‧‧‧2nd sealing member

73‧‧‧3rd sealing member

76‧‧‧cast film

77‧‧‧casting mode

77A‧‧‧ Concentrated liquid outlet

78‧‧‧Relief machine

78A‧‧‧ Decompression chamber

78B‧‧‧Relief fan

78C‧‧‧ suction tube

81‧‧‧1st dryer

81A‧‧‧1st intake duct

81AO‧‧‧1st air inlet

81B‧‧‧1st exhaust duct

81BO‧‧‧1st exhaust port

81DA‧‧‧1st dry wind

82‧‧‧2nd dryer

82A‧‧‧2nd exhaust duct

82AO‧‧‧2nd exhaust port

82B‧‧‧2nd intake duct

82BO‧‧‧2nd air inlet

82DA‧‧‧2nd dry wind

86‧‧‧ peeling roller

87‧‧‧Support roller

88‧‧‧ trimming device

89‧‧‧Cooling room

90‧‧‧Roller with knurling

77A‧‧‧ Concentrated liquid outlet

124‧‧‧with stepped roller

124BC‧‧‧ Small diameter roller

124BE‧‧‧ Large Diameter Roller

124M‧‧‧ support slot

CL‧‧‧ interval

CP‧‧‧cast position

D ₂₆ ‧‧‧thickness

D _124M ‧‧‧ Depth

P1‧‧‧ close to location

P2, P3‧‧‧ retreat position

P24‧‧‧The position where the casting belt 26 is in contact with the drum main body 24B

P25‧‧‧The position where the casting belt 26 is in contact with the drum main body 25B

X, Y, Z‧‧ Direction

Fig. 1 is an explanatory view showing an outline of a solution film forming apparatus.

Fig. 2 is a side view showing an outline of a casting device.

Fig. 3 is a perspective view showing an outline of each of the components disposed in the casing of the casting device.

4 is a view showing a belt moving portion, a belt moving direction control unit, and a control unit. A block diagram of the outline.

Fig. 5 is an explanatory view showing an outline of one end deviation detecting portion and the other end deviation detecting portion.

Fig. 6 is a plan view showing an outline of a horizontal drum in which a rotating shaft is at a reference position.

Fig. 7 is a plan view showing an outline of a horizontal drum when one end side of the rotating shaft is farther from the driving shaft than the other end side of the rotating shaft.

Fig. 8 is a plan view showing an outline of a horizontal drum when the other end side of the rotating shaft is farther from the driving shaft than the one end side of the rotating shaft.

Fig. 9 is a perspective view showing an outline of a belt guiding mechanism.

Fig. 10 is a perspective view showing the outline of the other end side guide roller.

Fig. 11 is a side view showing the outline of the other end side guide roller.

Fig. 12 is a top plan view showing an outline of a swinging guide roller main body.

Fig. 13 is a side view showing the outline of the other end side guide roller.

Fig. 14 is a perspective view showing an outline of a stepped drum.

Fig. 15 is a side view showing an outline of a stepped drum.

24, 25‧‧‧ horizontal drum

24A‧‧‧ drive shaft

24B, 25B‧‧‧ Stainless steel drum body

25A‧‧‧Rotary axis

25AS‧‧‧ bearing

26‧‧‧Casting zone

28‧‧‧With the Ministry of Movement

28AS‧‧‧Axis displacement

28LC‧‧‧Power Sensor

28M‧‧‧Drive motor

35S‧‧‧ bearing displacement

35SP‧‧‧ one end side bearing displacement

35SQ‧‧‧Other end side bearing displacement

36‧‧‧With guiding mechanism

36PA, 36PB‧‧‧ one end side guide roller

36QA, 36QB, 36QC‧‧‧ other end side guide rolls

77‧‧‧casting mode

77A‧‧‧ Concentrated liquid outlet

X, Y, Z‧‧ Direction

Claims (17)

A moving direction control device for controlling an endless belt in a moving direction of an endless belt, wherein the endless belt is wound around a driving roller and a driven roller disposed horizontally and in parallel with each other and moved by rotation of the driving roller The moving direction control device for the endless belt includes a guiding mechanism that guides an end surface in a width direction of the endless belt, and the guiding mechanism is disposed in a lower portion of the annular moving path in which the endless belt moves The width is two sides of the width direction. The moving direction control device for an endless belt according to claim 1, wherein the guiding mechanism is provided to be movable between a position close to the moving path and a retracted position away from the approaching position. The movement direction control device for an endless belt according to the first or second aspect of the invention, wherein the guide mechanism is biased toward a center side in a width direction of the movement path. The moving direction control device for an endless belt according to the first or second aspect of the invention, wherein the guiding mechanism is a guide roller having a roller body and a roller shaft, and the roller body is guided on a circumferential surface The roller end is axially supported by the roller shaft at the end surface in the width direction of the endless belt. a moving direction control device for an endless belt as described in claim 4, wherein A support groove for guiding the end surface of the endless belt in the width direction is formed on the circumferential surface of the roller body. The movement direction control device for an endless belt according to the third aspect of the invention, wherein the guide mechanism is a guide roller having a roller main body and a roller shaft, and the roller main body guides the annular belt on a circumferential surface The end surface in the width direction, the roller shaft axially supports the roller body. The movement direction control device for an endless belt according to the sixth aspect of the invention, wherein the circumferential surface of the roller body is formed with a support groove for guiding an end surface of the endless belt in the width direction. The movement direction control device for an endless belt according to the first or second aspect of the invention, wherein the guide mechanism includes one end side guide and the other end side guide, and the one end side guide is provided The other end side guide is disposed on the other end side in the width direction of the movement path, and the one end side guide and the other end side guide are in the ring. The belts are alternately arranged in the moving direction. The movement direction control device for an endless belt according to Item 8, wherein the one end side guide and the other end side guide are arranged to face the drive roller toward the drive roller. The central portion of the moving path in the width direction is close. The moving direction of the endless belt as described in item 3 of the patent application scope In the control device, the guide mechanism includes one end side guide and the other end side guide, the one end side guide is disposed on one end side in the width direction of the moving path, and the other end side guide is provided The other end side guide and the other end side guide are alternately arranged in the moving direction of the endless belt, on the other end side in the width direction of the moving path. The movement direction control device for an endless belt according to claim 10, wherein the one end side guide and the other end side guide are arranged to face the drive roller toward the drive roller. The central portion of the moving path in the width direction is close. The movement direction control device for an endless belt according to claim 1 or 2, further comprising: a driven roller shifting portion that moves the driven roller between the first posture and the second posture The first posture is a posture in which one end of the driven roller is closer to the driving roller than the other end, and the second posture is a posture in which the other end is closer to the driving roller than the one end; and an offset direction detecting unit detects The direction in which the endless belt is displaced from the movement path; and the driven drum posture control unit controls the driven roller shifting portion in accordance with the deviation direction detected by the deviation direction detecting unit. The movement direction control device for an endless belt according to claim 3, further comprising: a driven roller shifting portion that causes the driven roller to have a first posture and a first posture The second posture is a posture in which the one end of the driven roller is closer to the driving roller than the other end, and the second posture is a posture in which the other end is closer to the driving roller than the one end; a detecting unit that detects a direction in which the endless belt is displaced from the moving path; and a driven drum posture control unit that controls the driven roller shifting unit according to the deviation direction detected by the deviation direction detecting unit. The movement direction control device for an endless belt according to the first or second aspect of the invention, wherein the drive roller includes a drive roller main body and a drum drive shaft, and the drive roller main body supports the endless belt by a circumferential surface. In the back surface, the drum drive shaft pivotally supports the drive roller main body, and the drive roller main body has a small-diameter roller portion provided at a central portion in the width direction and a large-diameter roller portion provided at both end portions in the width direction, and the movement path is set at The circumferential surface of the small diameter roller portion. The moving direction control device for an endless belt according to claim 3, wherein the driving roller includes a driving drum main body and a drum driving shaft, and the driving roller main body supports a rear surface of the endless belt by a circumferential surface, the drum The drive shaft mainly supports the drive roller main body, and the drive roller main body has a small-diameter roller portion provided at a central portion in the width direction and a large-diameter roller portion provided at both end portions in the width direction, and the movement path is set in the small-diameter roller On the circumference of the ministry. A casting device which is formed of a dope on an endless belt Membrane, the apparatus has the following: a casting die that flows out of the concentrated liquid, the concentrated liquid includes a polymer and a solvent; a driving drum that is horizontally disposed; a driven roller that is horizontally disposed, and the driven roller is equipped with Provided in parallel with the driving roller; the endless belt is wound around the driving roller and the driven roller, and is moved by rotation of the driving roller, and the endless belt has support for flowing out from the casting die a supporting surface of the dope, wherein the dope flows out from the casting die toward a portion of the endless belt wound around the driving roller, and the film is formed on the supporting surface; and the film drying device blows dry wind to the film And evaporating the solvent from the film; a peeling device that peels the film from the endless belt; and a moving direction control device that controls a moving direction of the endless belt, wherein the moving direction control device includes the endless belt The guiding mechanism of the end surface in the width direction is disposed on both outer sides in the width direction of the lower portion of the annular moving path in which the endless belt moves. A solution film forming method for producing a film from a dope, the method comprising the steps of: forming a film composed of the dope on an endless belt, wherein the dope comprises a polymer and a solvent, and the endless belt is wound around a driving The drum and the driven roller are moved by the rotation of the driving drum, and the driving roller and the driven roller are disposed horizontally and parallel to each other, and the endless belt has a support a supporting surface of the dope flowing out of the casting die, wherein the dope flows out from the casting die toward a portion of the endless belt wound around the driving roller; and the drying film is blown to the film on the supporting surface and the aforementioned The solvent is evaporated from the film; the film is subjected to the film drying process from the endless belt; and the moving direction control device is used to control the moving direction of the endless belt, and the moving direction control device has the annular belt The guiding mechanism of the end surface in the width direction is disposed on both outer sides in the width direction of the lower portion of the annular moving path in which the endless belt moves.