TWI621578B - Control device of moving direction of circular belt, casting apparatus, and solution casting method - Google Patents

Abstract

The invention provides a moving direction control device for an endless belt, a casting device, and a solution film forming method. The endless casting belt is erected on a horizontal drum. The horizontal drum is rotated by a motor. The casting belt circulates on a moving path formed around a horizontal drum. The belt guide mechanism includes one end guide roller and the other end guide roller. The one-end guide roller is disposed on one end side in the Y direction of the lower part of the moving path. The other end side guide roller is disposed on the other end side in the Y direction in the lower part of the moving path.

Description

Device for controlling movement direction of endless belt, casting equipment and solution film forming method

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

A light-transmitting polymer film (hereinafter referred to as a film) is lightweight and easy to mold, so it is widely used as an optical film. Among them, cellulose ester films using cellulose halides and the like are used as optical films for liquid crystal display devices in addition to films for photosensitivity. As an optical film of a liquid crystal display device, there are a polarizer protective film, a retardation film, and the like.

A thin film is produced by a solution film forming method. The solution film forming method is a method having the following processes. First, a casting mold disposed in a casting chamber is used to flow a polymer solution (hereinafter referred to as a dope) toward a support that has undergone temperature adjustment, and a band-shaped casting 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 the casting film can be conveyed (hereinafter referred to as a film drying process). Thereafter, the cast film capable of being transported is peeled from the support as a wet film (hereinafter referred to as a peeling process). Then, the solvent is evaporated from the wet film as a film (hereinafter referred to as a film drying process).

As a support used in this solution film-forming method, an endless belt which is erected on a plurality of rollers and cyclically moves is known. Since the film formation process, the film drying process, and the peeling process can be repeatedly performed by using the loop belt, as a result, the production efficiency of the film can be improved.

However, if the solution film forming method is performed for a long time, it may cause a ring shape. The belt deviates from a predetermined circular path (an endless moving path). If the solution film forming method is performed in a state where the endless belt deviates from the endless path, the uniformity of the obtained thin film is deteriorated. In the uniformity of the film, the thickness, the surface state, and the uniformity of the optical characteristics in the width direction are particularly impaired.

As a method of adjusting the moving direction of the endless belt, for example, it is known to move a driving roller or a driven roller around which an endless belt is wound, as described in Japanese Patent Publication No. 2002-254452 or Japanese Patent Publication No. Hei 10-202722. Change invention.

However, in the method of controlling the moving direction of the endless belt in Japanese Patent Laid-Open Publication No. 2002-254452 and Japanese Patent Laid-Open Publication No. 10-202722, the moving direction of the endless belt is caused in the following cases (1) to (3) The control accuracy decreases. As a result, it is not only difficult for the endless belt to return to the endless path, but it also causes the endless belt to deviate significantly from the endless path.

(1) A case where the moving speed of the endless belt is increased for the purpose of improving the production efficiency of the solution film-forming method.

(2) When the movement speed of the endless belt is changed.

(3) When the temperature fluctuation of the endless belt during the film formation process, the film drying process, and the peeling process is repeatedly performed.

Thus, a method of controlling the movement direction of the endless belt that can more reliably limit the moving endless belt to the endless road is required.

An object of the present invention is to provide a moving endless belt that can be more reliably restricted 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 temperature change of the endless belt. Ring-like Belt moving direction control device, casting equipment and solution film forming method.

The movement direction control device of the endless belt according to the present invention is a movement direction control device of an endless belt that includes a guide mechanism and controls the movement direction of the endless belt. The endless belt is wound around a driving roller and a driven roller arranged horizontally and in parallel with each other, and is moved by the rotation of the driving roller. The guide mechanism guides the widthwise end surface of the endless belt. The guide mechanism is arranged on both outer sides in the width direction of the lower part of the endless moving path where the endless belt moves.

It is preferable that the guide mechanism is provided to move freely between a close position close to the moving path and a retracted position far from the close position. The guide mechanism is preferably a guide roller having a roller body and a roller shaft. The roller main body guides the widthwise end surface of the endless belt on the peripheral surface. The roller shaft supports the roller body. It is further preferred that a support groove that guides the widthwise end surface of the endless belt is formed on the peripheral surface of the roller body.

It is preferable that the guide mechanism is biased toward the center side in the width direction of the moving path. The guide mechanism is preferably a guide roller having a roller body and a roller shaft. The roller main body guides the widthwise end surface of the endless belt on the peripheral surface. The roller shaft supports the roller body. It is further preferred that a support groove that guides the widthwise end surface of the endless belt is formed on the peripheral surface of the roller body.

It is preferable that 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. The other end side guide is disposed on the other end side in the width direction of the moving path. One end guide and the other end guide are alternately arranged in the moving direction of the endless belt.

One end guide and the other end guide are arranged to roll with the driven It is preferable that the cylinder approaches the driving roller and approaches the central portion in the width direction of the moving path.

It is preferable that the movement direction control device of the endless belt further includes a driven roller shifting section, a deviation direction detecting section, and a driven roller attitude control section. The driven roller shifting unit changes 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 one end. The deviation direction detecting section detects the direction in which the endless belt deviates from the moving path. The driven roller attitude control unit controls the driven roller displacement unit based on the deviation direction detected by the deviation direction detection unit.

The driving roller preferably includes a driving roller main body and a roller driving shaft. The driving roller main body supports the back surface of the endless belt from the peripheral surface. The drum driving shaft axially supports the driving drum body. The driving roller main body includes 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 peripheral surface of the small-diameter roller portion.

The casting equipment of the present invention is a casting equipment for forming a film composed of a dope on an endless belt. The casting equipment 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 mold flows out of the dope. The dope includes a polymer and a solvent. The driving rollers are arranged horizontally. The driven roller is arranged horizontally. The driven roller is arranged parallel to the driving roller. The endless belt is wound around the driving roller and the driven roller, and is moved by the rotation of the driving roller. The endless belt has a supporting surface for supporting the thick liquid flowing from the casting die. The dope flows out from the casting die toward a portion of the endless belt wound around the driving drum. The film is formed on the support surface. Membrane drying device blows drying air to membrane And the solvent was evaporated from the membrane. The peeling device peels 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 a widthwise end surface of the endless belt. The guide mechanism is arranged on both outer sides in the width direction of the lower part of the endless moving path where the endless belt moves.

The solution film forming method of the present invention is a solution film forming method for producing a thin film from a dope. The solution film forming method includes a film formation step, a film drying step, a peeling step, and a movement control step. The film forming step forms a film made of a dope on the endless belt. The dope contains a polymer and a solvent. The endless belt is wound around the driving roller and the driven roller and is moved by the rotation of the driving roller. The driving roller and the driven roller are arranged horizontally and parallel to each other. The endless belt has a supporting surface for supporting the thick liquid flowing from the casting die. The dope flows out from the casting die toward a portion of the endless belt wound around the driving drum. The film drying step blows dry air to the film on the support surface and evaporates the solvent from the film. The peeling step peels the film through the film drying process from the endless belt. The movement control step controls the movement direction of the endless belt using a movement direction control device. The movement direction control device has a guide mechanism that guides the widthwise end surface of the endless belt. The guide mechanism is arranged on both outer sides in the width direction of the lower part of the endless moving path where the endless belt moves.

According to the present invention, regardless of the magnitude of the moving speed of the endless belt, the change in the moving speed of the endless belt, the amount of temperature change in the endless belt, and the like, the moving endless belt can be more reliably restricted to the endless path.

(Solution film forming equipment)

As shown in FIG. 1, the solution film forming apparatus 10 includes a casting device 15, a clip tenter 17, a drying device 18, and a winding device 19. Casting device 15 A wet film 13 is produced from the dope 12. The clip tenter 17 obtains the film 16 by drying the wet film 13. The drying device 18 further dries the film 16. The winding device 19 winds the film 16 on a winding core.

(Casting device)

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

(Casting support unit)

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

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

The horizontal means that the crossing angles of the horizontal drum 24 and the horizontal drum 25 with respect to the horizontal plane are 0 ° or more and 0.05 ° or less, respectively. In addition, parallel means that the crossing 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, dope 12 The casting width is preferably 1.1 times or more and 2.0 times or less. The length of the casting tape 26 is preferably 20 m or more and 200 m or less, for example. The thickness of the casting tape 26 is preferably 0.5 mm to 2.5 mm, for example. For uneven thickness of the casting tape 26, it is preferable to use a thickness of 0.5% or less with respect to the entire thickness. In addition, a surface (hereinafter referred to as a casting surface) 26A on which the cast film is formed and a back surface 26B in contact with the drum main body 24B and the drum main body 25B are formed flat. In particular, the cast surface 26A is preferably polished, and the surface roughness of the cast 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 unit 28 that moves the casting belt 26 wound around the horizontal drum 24 and the horizontal drum 25, and a belt moving direction control that restricts the moving direction of the casting belt 26.部 29 和 控制 部 30。 29 and control unit 30.

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

The driving motor 28M is connected to the driving shaft 24A. The control unit 30 controls the driving 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 body 24B is rotated, and the drum body 25B is rotated as the casting belt 26 is moved. Hereinafter, the moving direction of the casting belt 26 is referred to as an X direction, the width direction of the casting belt 26 is referred to as a Y direction, and the vertical direction is referred to as a Z direction.

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

The drive shaft 24A can move freely between a tension applied position and a relaxed position. The tension applying position is a position where a predetermined moving tension is applied to the casting belt 26 mounted on the roller body 24B and the roller body 25B. The relaxed position is a position where the casting belt 26 stretched over the drum body 24B and the drum body 25B is relaxed. The shaft displacement section 28AS moves the drive shaft 24A between the tension applied position and the relaxed position under the control of the control section 30. The shaft displacement portion 28AS preferably moves the drive shaft 24A while maintaining a state parallel to the rotation shaft 25A.

The force sensor 28LC is mounted on the drive shaft 24A. The force sensor 28LC detects an external force received by the drive shaft 24A. The control unit 30 reads the external force received by the drive shaft 24A from the force sensor 28LC. Next, the control unit 30 controls the shaft displacement unit 28AS based on the reading external force and the cross-sectional area value of the built-in casting belt 26 so that the moving tension applied to the casting belt 26 becomes a predetermined person. In this way, it is possible to apply the same moving tension to the casting belt 26 in the Y direction.

(With moving direction control unit)

The belt moving direction control unit 29 includes a drum swing mechanism 35 and a belt guide mechanism 36. The drum swing mechanism 35 swings the horizontal drum 25 in a direction in which the casting belt 26 deviates from the moving path 26R. The tape guide mechanism 36 guides both ends of the casting tape 26 in the Y direction.

(Roller swing mechanism)

The drum swing mechanism 35 includes a deviation detection portion 35K and a bearing displacement portion 35S. The deviation detection section 35K senses that the casting tape 26 has deviated from the movement path 26R. The bearing displacement portion 35S moves each pair of bearings 25AS independently in the X direction.

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

As shown in FIG. 5, the one-end deviation detection section 35KP includes a light emitting section 40PA and a light receiving section 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 has a built-in light sensor capable of receiving inspection light, and the light sensor determines whether or not the inspection light from the light emitting unit 40PA has been detected. When the light receiving section 40PB senses the inspection light, the light receiving section 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 in the Y direction of the moving path 26R of the casting belt 26 set in advance.

The other end deviation detection section 35KQ includes a light emitting section 40QA and a light receiving section 40QB similarly to the one end deviation detection section 35KP. The light emitting section 40QA has a built-in light source and emits inspection light from the light source to the outside. The light receiving unit 40QB has a built-in light sensor capable of receiving inspection light, and the light sensor determines whether 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 portion 40QA and the light-receiving portion 40QB are provided at the other ends in the Y direction of the moving path 26R of the casting band 26 through the optical path 40QX of the inspection light from the light-emitting portion 40QA to the light-receiving portion 40QB.

The moving path 26R is a reference path set in advance in the Y direction and 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 belt 26 plus a predetermined clearance width Degrees.

Returning to FIGS. 3 and 4, the bearing displacement portion 35S includes one end-side bearing displacement portion 35SP that moves one end side bearing 25AS and the other end-side bearing displacement portion 35SQ that moves the other end side bearing 25AS. The one-end bearing displacement portion 35SP and the other-end bearing displacement portion 35SQ independently move the bearing 25AS in a predetermined direction under the control of the control portion 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 a 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 signal is 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 band 26 is on the moving path 26R. On the other hand, when it is determined that the detection signal is output from the light receiving section 40QB (see FIG. 5) and the detection signal is not output from the light receiving section 40PB (see FIG. 5), the control section 30 determines that the casting tape 26 is from the moving path 26R to 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 band 26 deviates from the moving path 26R to the other end .

In addition, the control unit 30 performs a driven roller displacement process that adjusts the posture of the horizontal roller 25 based on the result of the deviation direction determination processing. In the driven roller displacement process, the control unit 30 controls the bearing displacement unit 35S based on the result of the deviation direction determination 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 bearing displacement portion 35SP and the other-end bearing displacement portion 35SQ so that the rotation shaft 25A is parallel to the drive shaft 24A. Set the position parallel to the drive shaft 24A as the reference position (see figure 6). On the other hand, when it is judged that the casting belt 26 deviates from the moving path 26R to one end side, one end side of the rotation shaft 25A is farther 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 contrary, when it is judged that the casting belt 26 deviates from the moving path 26R to the other end side, the other end side of the rotation shaft 25A is farther away from the drive shaft 24A than the one end side of the rotation shaft 25A. One end side bearing displacement part 35SQ (see FIG. 8).

(With guide mechanism)

As shown in FIGS. 9 and 10, the belt guide mechanisms 36 are disposed on both outer sides in the Y direction of the moving path 26R. The belt guide mechanism 36 includes one end guide rollers 36PA to 36PB and the other end guide rollers 36QA to 36QC. The one-end guide rollers 36PA to 36PB are one end-side guides arranged in the Y-direction one-end side of the lower portion of the moving path 26R. The other end guide rollers 36QA to 36QC are other end guides arranged on the other end side in the Y direction in the lower part of the moving path 26R. The lower part of the moving path 26R refers to a position from the casting belt 26 wound around the drum main body 25B away from the position P25 (see FIG. 2) to the casting belt 26 and the drum main body 24B moving toward the drum main body 24B. Between the contact positions P24 (see Figure 2). The one-end guide roller 36PA and the one-end guide roller 36PB are arranged in this order from the upstream side in the X direction toward the downstream side. For the same reason, the other end guide roller 36QA, the other end guide roller 36QB, and the other end guide roller 36QC are arranged in order from the upstream side in the X direction toward the downstream side.

And each guide roller 36PA ~ 36PB, each guide roller 36QA ~ 36QC It is preferable to alternately arrange in the X direction. Thereby, the force applied to the casting tape 26 can be minimized, and the casting tape 26 can be guided so as to be restricted to the moving path 26R.

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

In addition, the other end guide roller 36QA may include a swing shaft 55 and a link arm 56 connecting the guide roller shaft 52 and the swing shaft 55 arranged in parallel with the guide roller shaft 52. One end portion of the connecting arm 56 is fixed to the guide roller shaft 52, and the other end portion is supported by the swing shaft 55. The guide roller main body 51 swings freely between the close position P1 near the end 26RE in the Y direction in the moving path 26R by the connecting arm 56 and the retreat positions P2 to P3 retracted from the close position P1 (see FIG. 12). The retreat position P2 is closer to the upstream side in the X direction than the approach position P1, and the retreat position P3 is closer to the downstream side in the X direction than the approach position P1. The swinging shaft 55 and the connecting arm 56 can minimize the force applied to the casting belt 26 and guide the casting belt 26 so as to be restricted within the moving path 26R. In addition, a guide can be provided to be close to the position P1. The guide roller main body 51 performs a urging member.

The other end guide roller 36QA may include a shaft displacement portion 61 (see FIGS. 9 and 10) or a spring 62 (see FIG. 11). The shaft displacement section 61 displaces the swing shaft 55 in the Z direction. The spring 62 biases the guide roller body 51 toward the center in the Y direction. The control section 30 controls the shaft displacement section 61 so that the guide roller main body 51 is in a position such that the Y-direction belt end surface 26E of the casting belt 26 can be supported by the peripheral surface 51S (see FIG. 4). The control unit 30 preferably controls the shaft displacement unit 61 so as to prevent the casting tape 26 from contacting 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 housing 23. The force applied to the casting tape 26 can be minimized by the spring 62, and the casting tape 26 can be guided so as to be restricted within the moving path 26R.

In addition, since the one-end guide rollers 36PA to 36PB and the other-end guide rollers 36QB to 36QC have the same structure as the other-end guide rollers 36QA, detailed description is omitted.

Regardless of whether the guide roller body 51 is disposed on one end side or on the other end side, the bottom surface 51DD of the support groove 51D of the guide roller body 51 near the position P1 and the Y-direction end portion of the moving path 26R The interval CL of the 26RE (see FIG. 11) is preferably decreased from the upstream side toward the downstream side in the X direction. The interval CL (see FIG. 11) is, for example, 0 mm or more and 20 mm or less. For example, regarding the interval CL _QA of the other end guide roller 36QA, the interval CL _PA of the one end guide roller 36PA, the interval CL _QB of the other end guide roller 36QB, and the end guide roller It is preferable that the interval CL _{PB of} 36PB 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)

(Partition unit)

Returning to FIG. 2, the partition unit includes first to third sealing members 71 to 73. The first to third sealing members 71 to 73 are arranged in the casing 23 from the upstream side in the X direction toward the downstream side in this order. The first sealing member 71 to the third sealing member 73 are provided so as to protrude from the inner wall surface of the case 23 and protrude to the casting surface 26A of the casting belt 26. Inside the casing 23, that is, a section surrounded by the inner wall surface of the casing 23 and the casting surface 26A is partitioned into a casting chamber 23A by a first sealing member 71 to a third sealing member 73 from the upstream side in the X direction toward the downstream side. The drying chamber 23B and the peeling chamber 23C. The airtightness of the casting chamber 23A is maintained by the first sealing member 71 to the second sealing member 72. 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 for forming a casting film 76 from the dope 12 (see FIG. 1) is provided in the casting chamber 23A. The casting unit includes a casting die 77 and a decompressor 78. The casting die 77 has a concentrated liquid outlet 77A through which the concentrated liquid 12 (see FIG. 1) flows. The casting die 77 is disposed above the horizontal drum 24 so that a part of the casting belt 26 wound around the drum main body 24B is close to the thick liquid outlet 77A.

The casting die 77 flows the dope 12 from the dope outlet 77A toward the casting zone 26 (see FIG. 1). The dope 12 (see FIG. 1) flowing out from the dope outlet 77A and reaching the casting surface 26A forms a liquid bead. Reaching cast surface 26A As a result of the dope 12 being cast in the X direction, a band-shaped casting film 76 is formed.

The decompressor 78 is used for decompressing the upstream side of the liquid beads in the X direction. The decompressor 78 includes a decompression chamber 78A, a decompression fan 78B, and a suction pipe 78C. The decompression chamber 78A is arranged 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 gas in the decompression chamber 78A. The suction pipe 78C connects the decompression fan 78B and the decompression chamber 78A.

(Film drying unit)

A film drying unit for drying the cast film is arranged in the drying chamber 23B. The film drying unit includes a first dryer 81 to a second dryer 82 that supply a predetermined drying air to the casting film 76 and a drying controller (not shown). The first dryer 81 to the second dryer 82 are installed in the drying chamber 23B in this order from the upstream side in the X direction toward the downstream side. The first dryer 81 is disposed above the casting belt 26 that is mounted on the horizontal drum 24 and the horizontal drum 25. The second dryer 82 is disposed below the casting belt 26 that is mounted on 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 provided 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 arranged separately from the casting belt 26. The first intake duct 81A is provided with a first intake port 81AO that sends out a first dry wind 81DA. The first air inlet 81AO opened toward the downstream side in the X direction is extended from one end of the casting film 76 to the other end. The first exhaust duct 81B is provided with a first exhaust port 81BO that discharges the first dry air 81DA. The first exhaust port 81BO opened toward the upstream side in the X direction is extended 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 this 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 arranged separately from the casting belt 26. The second exhaust duct 82A is provided with a second exhaust port 82AO that discharges the second dry air 82DA. The second exhaust port 82AO opened downstream in the X direction is extended from one end of the casting film 76 to the other end. The second air inlet duct 82B is provided with a second air inlet 82BO that sends out the second dry air 82DA. The second air inlet port 82BO opened toward the upstream side in the X direction is extended from one end of the casting film 76 to the other end.

The drying controller independently adjusts the temperature or wind speed of the first drying wind 81DA and the second drying wind 82DA. The drying controller includes a first temperature controller to a second temperature controller (not shown), and a first fan to a second fan (not shown) that adjusts the air volume of the first drying air 81DA and the second drying air 82DA. And controller (not shown). The first temperature controller to the second temperature controller adjust the temperature of the first drying wind 81DA and the second drying wind 82DA. The first temperature regulator to the second temperature regulator and the first blower fan to the second blower fan are installed in each duct of the first dryer 81 to the second dryer 82. The controller controls the first temperature regulator ~ the second temperature regulator and the first blower fan ~ the second blower fan, and independently adjusts the temperature or wind speed of the first drying wind 81DA and the second drying wind 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 become a peelable state from the casting belt 26 as the wet film 13 and sends the wet film 13 from an outlet 23CO provided in the peeling chamber 23C.

A condensing device for condensing a solvent contained in the atmosphere in the casing 23 and a recovering device for recovering the condensed solvent may be provided in the casting device 15. Thereby, the concentration of the solvent contained in the atmosphere in the casing 23 can be kept within a constant range.

Returning to FIG. 1, a plurality of support rollers 87 supporting the wet film 13 are arranged on the transfer section between the casting device 15 and the clip tenter 17. The support roller 87 is rotated around a shaft by a motor (not shown). The support roller 87 supports the wet film 13 sent out from the casting device 15 and guides it to the clip tenter 17. Although FIG. 1 shows a case where two support rollers 87 are arranged in the transfer section, the present invention is not limited to this, and one or three or more support rollers 87 may be arranged in the transfer section. The support roller 87 may be a free roller.

The clip tenter 17 includes a plurality of clips that hold the two side edge portions in the width direction of the wet film 13, and the clips move on a stretching rail. The wet film 13 held by the clip is sent into the drying wind, and the wet film 13 is stretched and dried in the width direction.

A trimming device 88 is provided between the clip tenter 17 and the drying device 18. A gripping mark formed by a clip is formed at both ends in the width direction of the film 16 fed out of the trimming device 88. The trimming device 88 cuts off both end portions having the grip marks. The cut-off part is fed into the cut-off fan (not shown) and the crusher (not shown) by the blower in order to be chopped 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 casing includes a transport path for the film 16. The plurality of rollers 18A form a transport path for the film 16. The air conditioner controls the temperature or humidity of the atmosphere in the casing. Adjustment. The film 16 introduced into the casing is conveyed while being wound around a plurality of rollers 18A. By adjusting the temperature or humidity of the atmosphere, the residual solvent is evaporated from the film 16 conveyed in the casing. In addition, an adsorption recovery device is connected to the drying device 18 to recover the solvent evaporated from the film 16 by adsorption.

A cooling chamber 89, a static elimination rod (not shown), a knurled roller 90, and a trimming device (not shown) are provided in order from the upstream side between the drying device 18 and the winding device 19. The cooling chamber 89 cools the film 16 until the temperature of the film 16 becomes approximately room temperature. The static elimination rod performs a static elimination process to remove static electricity from the thin film 16 sent from the cooling chamber 89 and charged. The knurled roller 90 imparts knurling to the 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 knurling remains at both ends in the width direction of the cut film 16.

The winding device 19 includes a pressure roller 19A and a winding core 19B. The film 16 fed into the winding device 19 is wound into a roll core 19B while being pressed by a pressure roller 19A, and has a roll shape.

Next, the operation of the present invention will be described. As shown in FIGS. 3 and 4, a predetermined moving tension is applied to the casting belt 26 by the axis displacement portion 28AS, the force sensor 28LC, and the control portion 30. The horizontal drum 24 is rotated by the driving motor 28M and the control unit 30. Thereby, the casting belt 26 moves on the moving path 26R, that is, the moving path 26R in the casing 23 sequentially moves cyclically in each of the chambers 23A to 23C.

(Film formation process)

As shown in FIG. 2, a casting process is performed in the casting chamber 23A to form a casting film 76 composed of the dope 12 on the casting belt 26. Casting die 77 from dope The outlet 40A continuously flows the dope 12. The dope 12 flowing out from the casting die 77 passes through the casting belt 26 to form liquid beads, and is cast on the casting belt 26. In this way, 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 of blowing a predetermined drying air to the casting film 76 and evaporating the solvent from the casting film 76 is performed. The film drying process is performed until the casting film 76 becomes a state where it can be conveyed independently. In the film drying process, a first film drying process of blowing a first drying wind 81DA to the casting film 76 and a second film drying process of blowing a second drying wind 82DA to the casting film 76 are sequentially performed.

In the first film drying process, the casting film 76 having a relative solvent content of 250% by mass or more and 400% by mass or less is preferably performed, and the relative solvent content rate is 300% by mass or more and 350% by mass or less of the casting film 76 Better done. The temperature of the first drying wind 81DA is preferably 30 ° C or higher and 80 ° C or lower. The wind speed of the first dry wind 81DA is preferably 5 m / s or more and 25 m / s or less.

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

Among them, the content of the solvent is the amount of the solvent contained in the casting film or each film on a dry basis. When a sample is taken from the target film, the weight of the sample is set to x, and the weight of the dried sample is set to When y, it is expressed as {(xy) / y} × 100.

(Stripping Process)

In the peeling chamber 23C, peeling from the casting tape 26 is performed so as to be peelable. The peeling process of the cast film 76 in a separated state. The peeling roller 86 peels off the casting film 76 in a peelable state from the casting tape 26 as the wet film 13, and sends the wet film 13 from an outlet 23CO provided in the peeling chamber 23C. The peeling process is preferably performed with the casting film 76 having a content ratio of the solvent of 20% by mass or more and 80% by mass or less.

After the peeling process, a film forming process is performed on the casting tape 26 again. In this way, the casting apparatus 15 repeatedly performs a film formation process, a film drying process, and a peeling process. The wet film 13 can be continuously produced from the dope 12 by the casting device 15.

Among them, when the control section 30 detects that the casting belt 26 deviates from the moving path 26R, the control section 30 controls the driven roller displacement processing of the bearing displacement section 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 roller transfer process. However, when the moving speed of the casting belt 26 is large (for example, 50 m / min or more), or when the moving speed of the casting belt 26 is greatly changed (for example, 2 m / minute ² or more), or the film forming process is repeatedly performed, When the temperature variation 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 belt 26 to the moving path 26R only by determining the deviation from the direction. The casting belt 26 is further deviated from the moving path 26R.

In the casting device 15, the tape guide mechanism 36 can maintain the casting belt 26 within a range of the width of the moving path 26R plus a constant clearance amount. Therefore, it is possible to prevent the casting belt 26 from largely deviating from the moving path 26R. In addition, it is possible to avoid the deviation of the casting belt 26 by performing the shifting process of the driven roller in this state. Road 26R. In this way, the dope 12 (see FIG. 1) flowing from the casting die 77 can land on the casting position CP (see FIG. 8) of the casting surface 26A, and the casting belt 26 can be restricted to the moving path 26R.

The drum swing mechanism 35 may 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 moving path 26R may be set to 0 (see FIG. 13).

When the roller swing mechanism 35 (see FIG. 4) is used, the guide roller closest to the horizontal roller 25 needs to be away from the horizontal roller 25 to the extent that it does not contact the swing horizontal roller 25. However, when the roller swing mechanism 35 is omitted, the guide roller closest to the horizontal roller 25 can be brought closer to the horizontal roller 25.

In addition, a stepped roller 124 shown in FIGS. 14 and 15 may be used instead of the horizontal roller 24. The stepped roller 124 is disposed in the casing 23 horizontally and parallel to the horizontal roller 25, and includes a drive shaft 124A and a stainless steel drum body 124B fixed to the drive shaft 124A. The drum main body 124B includes a small-diameter roller portion 124BC at a center portion in the Y direction, and includes large-diameter roller portions 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 moving path 26R. The moving path 26R is set on the peripheral surface of the small-diameter roller portion 124BC. The depth D _124M of the support groove 124M of the casting belt 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 subtracted. The casting belt 26 wound around the peripheral surface of the small-diameter roller portion 124BC may not extend to the extent of the large-diameter roller portion 124BE. For example, it may be 0.5 times or more and 5 times or less the thickness D ₂₆ of the casting belt 26. . It is possible to prevent the casting belt 26 from deviating from the moving path 26R by the belt-shaped roller 124.

When the belt-shaped roller 124 is used, the roller swing mechanism 35 or the belt guide mechanism 36 can be omitted.

The film 16 obtained by the present invention can be used in particular as 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. Moreover, when the width of the film 16 is larger than 2500 mm, the present invention is also effective. The thickness of the thin film 16 is preferably 20 μm or more and 80 μm or less.

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

The method for measuring the in-plane retardation Re is as follows. Regarding the in-plane retardation Re, the sample film was subjected to humidity adjustment at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours. 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 advance axis 2, and d represents the thickness (film thickness) of the thin film.

The measurement method of the thickness direction retardation Rth is as follows. The sample film was humidity-conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, and the value measured from a vertical direction with an ellipsometry (M150 manufactured by Nippon Kogyo Co., Ltd.) at 632.8 nm was the same as when the film surface was inclined 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-mentioned embodiment, the polymer used as the raw material of a polymer film is not specifically limited, For example, a cellulose halide or a cyclic polyolefin is mentioned.

(Cellulose trioxide)

There may be only one fluorene group of the cellulose sulfonium compound used in the present invention, or two or more fluorene groups may be used. When two or more kinds of fluorenyl groups are used, it is preferable that one of them is an ethenyl group. The ratio of esterification of the hydroxyl groups of cellulose with a carboxylic acid, that is, the degree of substitution of the fluorene group satisfies all of the following formulas (I) to (III). In the following formulae (I) to (III), A and B represent the degree of substitution of the fluorenyl group, A is the degree of substitution of the ethenyl group, and B is the degree of substitution of the fluorenyl group having 3 to 22 carbon atoms. In addition, it is preferable that 90% by mass or more of cellulose triacetate (TAC) is 0.1 mm to 4 mm.

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

Cellulose, which is a raw material of cellulose mash, can be obtained from any of lint fiber and pulp.

The fluorenyl group having a carbon number of 2 or more as the cellulose phosphonium compound of the present invention may be The aliphatic group may be an aryl group, and is not particularly limited. These are, for example, alkyl carbonyl esters, alkenyl carbonyl esters or aromatic carbonyl esters, aromatic alkyl carbonyl esters, and the like of cellulose, and they may each have a further substituted group. As these preferable examples, propionyl, butylfluorenyl, pentamyl, hexyl, octyl, decyl, dodecylfluorenyl, tridecylfluorenyl, tetradecylfluorenyl, hexadecane Fluorenyl, octadecylfluorenyl, isobutylfluorenyl, tert-butylfluorenyl, cyclohexanecarbonyl, oleyl, benzamyl, naphthylcarbonyl, and cinnamylfluorenyl. Among them, propionyl, butyl fluorenyl, dodecyl fluorenyl, octadecyl fluorenyl, tert-butyl fluorenyl, oleyl fluorenyl, benzyl fluorenyl, naphthyl carbonyl and cinnamon fluorenyl, etc. are more preferable, and propyl fluorenyl and butyl fluorenyl .

(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, n-propanol, Butanol and diethylene glycol, etc.), ketones (for example, acetone and methyl ethyl ketone, etc.), esters (for example, methyl acetate, ethyl acetate, and propyl acetate, etc.) and ethers (for example, tetrahydrofuran and methyl cellosolve, etc.) Wait. The dope in the present invention refers to a polymer solution and a dispersion obtained by dissolving or dispersing a polymer in a solvent.

Among them, it is preferable to use a halogenated hydrocarbon having 1 to 7 carbon atoms, and it is most preferable to use dichloromethane. From the viewpoints of 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, in addition to dichloromethane, one type or even several types of carbon atoms are mixed. Alcohol is preferred. The content of the alcohol is preferably 2% to 25% by mass relative to all solvents, and more preferably 5% to 20% by mass. Specific as alcohol Examples include methanol, ethanol, n-propanol, isopropanol, and n-butanol. However, it is preferable to use methanol, ethanol, n-butanol, or a mixture thereof.

However, recently, with a view to minimizing the impact on the environment, the composition of the solvent when methylene chloride is not used has also been reviewed. For this purpose, it is preferable to use an ether having 4 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms, an ester having 3 to 12 carbon atoms, and an alcohol having 1 to 12 carbon atoms. These are sometimes mixed and used appropriately. Examples include mixed solvents of methyl acetate, acetone, ethanol, and n-butanol. These ethers, ketones, esters, and alcohols may be those having a cyclic structure. In addition, a compound having any one of two or more functional groups of ether, ketone, ester, and alcohol (that is, -O-, -CO-, -COO-, and -OH) can also be used as a solvent.

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

10‧‧‧Solution film forming equipment

12‧‧‧ dope

13‧‧‧ wet film

15‧‧‧casting device

16‧‧‧ dry film

17‧‧‧Clamp tenter

18‧‧‧ drying device

18A‧‧‧roller

19‧‧‧ Take-up device

19A‧‧‧Press roller

19B‧‧‧roll core

23‧‧‧shell

23A‧‧‧Casting Room

23B‧‧‧Drying room

23C‧‧‧ Strip Room

23CO‧‧‧Export

23S‧‧‧Inner wall surface

24, 25‧‧‧Horizontal roller

24A, 124A‧‧‧Drive shaft

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

25A‧‧‧Rotating shaft

25AS‧‧‧bearing

26‧‧‧casting zone

26A‧‧‧cast face

26B‧‧‧Back

26E‧‧‧ with end face

26R‧‧‧Mobile

26RE‧‧‧Y-direction end of 26R

27‧‧‧ with mobile unit

28‧‧‧ with mobile

28AS‧‧‧Axis displacement

28LC‧‧‧Power Sensor

28M‧‧‧Drive motor

29‧‧‧ with moving direction control unit

30‧‧‧Control Department

35‧‧‧Roller swing mechanism

35K‧‧‧Departure detection section

35KP‧‧‧One end deviation detection section

35KQ‧‧‧The other end deviation detection section

35S‧‧‧bearing displacement

35SP‧‧‧One end side bearing displacement

35SQ‧‧‧The other side bearing displacement part

36‧‧‧ with guide mechanism

36PA, 36PB‧‧‧One side guide roller

36QA, 36QB, 36QC‧‧‧The other end side guide roller

40PA, 40QA‧‧‧Lighting Department

40PB, 40QB ‧‧‧ Light receiving section

40PX, 40QX‧‧‧Light path

51‧‧‧Guide roller body

51D‧‧‧Support slot

51DD‧‧‧Underside

51DS‧‧‧Side

51S‧‧‧ weekly

52‧‧‧Guide roller

55‧‧‧ swing axis

56‧‧‧ link arm

61‧‧‧axis displacement

62‧‧‧Spring

71‧‧‧The first sealing member

72‧‧‧Second sealing member

73‧‧‧ 3rd sealing member

76‧‧‧cast film

77‧‧‧casting die

77A‧‧‧Concentrated liquid outlet

78‧‧‧pressure reducing machine

78A‧‧‧Decompression chamber

78B‧‧‧Decompression Fan

78C‧‧‧Suction tube

81‧‧‧The first dryer

81A‧‧‧The first intake duct

81AO‧‧‧The first air inlet

81B‧‧‧The first exhaust duct

81BO‧‧‧The first exhaust port

81DA‧‧‧The first dry wind

82‧‧‧Second dryer

82A‧‧‧ 2nd exhaust duct

82AO‧‧‧Second exhaust port

82B‧‧‧ 2nd intake duct

82BO‧‧‧ 2nd air inlet

82DA‧‧‧The second dry wind

86‧‧‧ peeling roller

87‧‧‧Support roller

88‧‧‧Edge trimming device

89‧‧‧cooling room

90‧‧‧ Roller with knurled

77A‧‧‧Concentrated liquid outlet

124‧‧‧ with step roller

124BC‧‧‧Small diameter roller section

124BE‧‧‧Large Diameter Roller Section

124M‧‧‧Support slot

CL‧‧‧ interval

CP‧‧‧casting position

D ₂₆ ‧‧‧Thickness

D _124M ‧‧‧ Depth

P1‧‧‧close location

P2, P3‧‧‧Retreat position

P24‧‧‧Position where the casting belt 26 contacts the drum body 24B

P25‧‧‧The position where the casting belt 26 contacts the drum body 25B

X, Y, Z‧‧‧ directions

FIG. 1 is an explanatory diagram showing an outline of a solution film forming apparatus.

FIG. 2 is a side view showing the outline of a casting device.

Fig. 3 is a perspective view showing an outline of each component arranged in a casing of a casting device.

Fig. 4 is a diagram showing a belt moving section, a belt moving direction control section, and a control section; Summary block diagram.

FIG. 5 is an explanatory diagram showing the outline of one end deviation detection section and the other end deviation detection section.

FIG. 6 is a plan view showing an outline of a horizontal drum whose rotation shaft is at a reference position.

FIG. 7 is a schematic plan view showing a horizontal drum when one end side of the rotation shaft is farther from the drive shaft than the other end side of the rotation shaft.

FIG. 8 is a schematic plan view showing a horizontal drum when the other end side of the rotation shaft is farther from the drive shaft than the one end side of the rotation shaft.

Fig. 9 is a perspective view showing an outline of the tape guide 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 view showing an outline of a guide roller main body that can swing freely.

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 roller.

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

Claims (15)

A moving direction control device for an endless belt that controls a moving direction of the endless belt. The endless belt is wound around a driving roller and a driven roller that are arranged horizontally and in parallel with each other and moves by the rotation of the driving roller. Wherein, the moving direction control device of the endless belt includes a guide mechanism that guides a widthwise end surface of the endless belt, and the guide mechanism is disposed in a lower middle portion of the endless belt moving path. The driving roller includes a driving roller main body and a roller driving shaft. The driving roller main body supports a back surface of the endless belt by a peripheral surface. The roller driving shaft axially supports the driving roller main body. The drum main body includes a small-diameter roller portion provided at a central portion in the width direction and a large-diameter roller portion provided at both ends in the width direction. The moving path is set on a peripheral surface of the small-diameter roller portion. The moving direction control device for the endless belt according to item 1 of the scope of patent application, wherein the guide mechanism is provided to move freely between a close position close to the moving path and a retracted position far from the close position. The moving direction control device for an endless belt according to item 1 or 2 of the scope of patent application, wherein the guide mechanism is urged toward a center side in a width direction of the moving path. The transfer of the endless belt as described in the first or second scope of the patent application The moving direction control device, wherein the guide mechanism is a guide roller including a roller body and a roller shaft, the roller body guides a widthwise end surface of the endless belt on a peripheral surface, and the roller shaft pivots the roller body support. The moving direction control device for an endless belt according to item 4 of the scope of patent application, wherein a support groove is formed on the peripheral surface of the roller body to guide the end surface in the width direction of the endless belt. The moving direction control device for an endless belt according to item 3 of the scope of patent application, wherein the guide mechanism is a guide roller including a roller body and a roller shaft, and the roller body guides the endless belt on a peripheral surface. The width direction end face of the roller shaft supports the roller body. The moving direction control device for an endless belt according to item 6 of the patent application scope, wherein a support groove for guiding a widthwise end surface of the endless belt is formed on the peripheral surface of the roller body. According to the moving direction control device of the endless belt according to item 1 or item 2 of the patent application scope, the guide mechanism includes one end side guide and the other end side guide, and the one end side guide is provided with It is provided on one end side in the width direction of the moving path, and 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 in the ring. The strips are arranged alternately in the moving direction. The moving direction control device for the endless belt according to item 8 of the scope of patent application, wherein the one end guide and the other end guide are arranged to move toward the driving roller from the driven roller toward the driving roller. The width direction central part of the said moving path approaches. According to the moving direction control device of the endless belt according to item 3 of the scope of the patent application, the guide mechanism includes one end-side guide and the other end-side guide, and the one end-side guide is disposed in the movement. One end side of the width direction of the road, the other end side guide is disposed on the other end side of the width direction of the moving path, and the one end side guide and the other end side guide move in the endless belt. Alternately arranged in the direction. The moving direction control device for the endless belt according to item 10 of the patent application scope, wherein the one end-side guide and the other end-side guide are arranged to move toward the driving roller from the driven roller toward the driving roller. The width direction central part of the said moving path approaches. The moving direction control device for the endless belt according to item 1 or 2 of the scope of patent application, further comprising: a driven roller shifting unit that moves the driven roller between the first posture and the second posture In other words, 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; the deviation direction detecting section detects The endless belt deviates from the moving path And a driven drum attitude control unit that controls the driven drum shifting unit based on the deviation direction detected by the deviation direction detection unit. The moving direction control device for the endless belt according to item 3 of the scope of patent application, further comprising: a driven roller shifting unit that changes 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; a deviation direction detecting section that detects the ring A direction in which the ribbon deviates from the moving path; and a driven roller attitude control unit that controls the driven roller shifting unit based on the deviation direction detected by the deviation direction detection unit. A casting device that forms a film composed of a dope on an endless belt, the device is provided with the following: a casting die that flows out of the dope, the dope includes a polymer and a solvent; and a driving roller, which is arranged horizontally. The driven roller is arranged horizontally, and the driven roller is arranged parallel to the driving roller; the endless belt is wound around the driving roller and the driven roller, and is driven by the driving roller. Rotating to move, the endless belt has a supporting surface for supporting the concentrated liquid flowing out of the casting die, and the concentrated liquid flows out from the casting die toward a part of the endless belt wound around the driving roller. The film is formed on the support surface; a film drying device that blows drying air to the film and evaporates the solvent from the film; a peeling device that peels the film from the endless belt; and a moving direction control device that controls The moving direction of the endless belt, the moving direction control device includes a guide mechanism that guides a widthwise end surface of the endless belt, and the guide mechanism is disposed in a lower middle portion of the endless moving path where the endless belt moves. The driving roller includes a driving roller main body and a roller driving shaft. The driving roller main body supports a back surface of the endless belt by a peripheral surface. The roller driving shaft axially supports the driving roller main body. The drum main body includes a small-diameter roller portion provided at a central portion in the width direction and a large-diameter roller portion provided at both ends in the width direction. The moving path is set on a peripheral surface of the small-diameter roller portion. A solution film forming method for manufacturing a thin film from a dope, the method includes the steps of forming a film composed of the dope on an endless belt, the dope including a polymer and a solvent, and the endless belt being wound on a drive The drum and the driven drum are moved by the rotation of the driving drum. The driving drum and the driven drum are arranged horizontally and in parallel with each other. The endless belt has a support for supporting the thick liquid flowing from the casting die. Surface, the concentrated solution flows out from the casting die toward the part of the endless belt wound on the driving roller; blows dry air to the film on the support surface and evaporates the solvent from the film; Peeling the film that has undergone the film drying process from the endless belt; and controlling the moving direction of the endless belt with a moving direction control device having a guide for guiding the widthwise end surface of the endless belt The guide mechanism is arranged on both outer sides in the width direction of the lower part of the endless moving path where the endless belt moves, and the driving roller includes a driving roller body and a roller driving shaft. The back surface of the endless belt is supported on a surface, and the drive roller main body is axially supported by the drum driving shaft. The drive roller main body includes a small-diameter roller portion provided at a central portion in the width direction and a large-diameter roller provided at both ends in the width direction. The moving path is set on a peripheral surface of the small-diameter roller section.