KR20120107850A - Method and apparatus for forming flexible film, and solution film forming method - Google Patents

Abstract

PURPOSE: A method and device for forming a flexible membrane are provided to efficiently product a flexible membrane or film while restraining a thickness deviation. CONSTITUTION: A method and device for forming a flexible membrane comprises: a step of flowing dope to a movable support; a step of evaporating a solvent from a flexible membrane which is formed on a surface of the movable support; a step of cooling the flexible membrane by being a state able to be returned; a step of separating the flexible membrane from the movable support; a step of heating the movable support; and a step of heating the flexible membrane by using heat applied to the movable support. [Reference numerals] (127) Wet film drying process; (131) Dope-flowing process; (132) Flexibilization process; (133) Membrane-heating process; (134) Skin layer-forming process; (135a) Pre membrane-drying process; (135b) Post membrane-drying process; (136) Membrane-cooling process; (137) Separation process; (138) Support-heating process; (21) Film; (24) Dope; (25) Wet film; (61) Flexible membrane

Description

METHOD AND APPARATUS FOR FORMING FLEXIBLE FILM, AND SOLUTION FILM FORMING METHOD

TECHNICAL FIELD This invention relates to the formation method and apparatus of a cast film, and a solution film forming method.

The polymer film (henceforth a film) is used for various uses as an optical film from the characteristics, such as the outstanding light transmittance, flexibility, and light weight thinning. Especially, the cellulose-ester type film using cellulose acylate etc. is used for the optical film. As an optical film, there exist a protective film, a retardation film, etc. of a polarizing plate, including the film for photosensitive. The protective film and retardation film of a polarizing plate are the structural members of the liquid crystal display device which the market expanded recently.

As a manufacturing method of a film, there exists a solution film forming method. The solution film forming method includes a cast film forming step, a film self-supporting step, a peeling step, and a wet film drying step. In the cast film formation step, the dope dissolved in the solvent flows down, and a cast film made of the dope is formed on the support. In the membrane self-supporting step, the solvent is evaporated from the flexible membrane until it becomes self-supporting and can be transported, that is, until the solidification proceeds at least a certain amount. In a peeling process, a cast film is peeled from a support body and it is set as a wet film. In a wet film drying process, a solvent is evaporated from a wet film and it is set as a film.

Japanese Laid-Open Patent Publication No. 2006-306059 discloses a method of sequentially performing a film drying step of evaporating a solvent from a flexible film, and a film cooling step of cooling the flexible film until it becomes self-supporting and transportable in the membrane self-supporting step. . According to the method of Unexamined-Japanese-Patent No. 2006-306059, the time required for solidification of a flexible film | membrane is performed just before a peeling process, compared with a film drying process. For this reason, the peeling failure (a tearing failure in which the peeled flexible film is torn off, or the peeling residual failure in which a part of the flexible film remains on the support) due to lack of drying of the flexible film can be avoided. As a result, since the support speed can be improved, the production efficiency of a film can be improved compared with the past.

However, although the production efficiency of a film was able to be improved by using the method of Unexamined-Japanese-Patent No. 2006-306059, the optical characteristic (in-plane retardation (Re) and thickness direction retardation resulting from the thickness variation of the obtained film) was made. (Rth, etc.) has been a problem. As such a cause of the deviation of optical characteristics, the fact that the required specification of the optical film is improved, and that the thinning of the optical film has progressed in accordance with the thinning of the liquid crystal display device.

Then, an object of this invention is to provide the solution film forming method which can produce a film efficiently, suppressing the thickness variation as mentioned above, and the drying method and apparatus of the cast film used for this solution film forming method.

The formation method of the flexible film of this invention is a formation method of the flexible film which forms a flexible film in a moving support body. The moving support moves so as to repeatedly pass through the arrival position where the falling dope reaches and the peeling position where the flexible film is peeled off. The method for forming the flexible film includes a dope falling step (step A), a film drying step (step B), a film cooling step (step C), a peeling step (step D), and a support heating step (step E). Equipped. Step A causes the dope to flow down to the moving support. The said dope contains a polymer and a solvent. In step B, the solvent is evaporated from the flexible film formed on the surface of the moving support. The flexible film is made of doped falling in the A step. Step C cools the flexible membrane until it becomes self-supporting and conveyable. Cooling is performed after the said B step. In step D, the cast film after step C is peeled from the moving support. In step E, the moving support after the step C is heated in the next step B. Step F uses the heat applied to the moving support in step E to heat the flexible membrane before the next step B.

In the step E, it is preferable to heat the moving support before the next step A, and to heat the moving support after the next step A.

In the step E, the movable support is heated so that the flexible region for forming the flexible film with the dropped dope is higher than the non-flexible region except the flexible region on the surface of the movable support. It is desirable to.

It is preferable to perform said F step until the temperature of the said moving support body in said D step is 5 degreeC or more and 15 degrees C or less, and the temperature of the said moving support body becomes 8 degreeC or more and below the boiling point of the said solvent.

In the method for forming the flexible film of the present invention, it is preferable that a skin layer forming wind is applied to the surface of the flexible film to form a skin layer on the surface side of the flexible film. This skin layer forming step is performed between the F step and the next B step.

The solution film forming method of the present invention is a solution film forming method for producing a film by peeling and drying the cast film formed on the moving support. The moving support moves so as to repeatedly pass through the arrival position where the falling dope reaches and the peeling position where the flexible film is peeled off. The solution forming method includes a dope dripping step (step A), a film drying step (step B), a membrane cooling step (step C), a peeling step (step D), a support heating step (step E), and a film A heating step (step F) and a film drying step (step G). Step A causes the dope to flow down to the moving support. The said dope contains a polymer and a solvent. In step B, the solvent is evaporated from the flexible film formed on the surface of the moving support. The flexible film is made of doped falling in the A step. Step C cools the flexible membrane until it becomes self-supporting and conveyable. Cooling is performed after the said B step. In step D, the cast film after step C is peeled from the moving support. In step E, the moving support after the step C is heated in the next step B. Step F uses the heat applied to the moving support in step E to heat the flexible membrane before the next step B. In step G, the solvent is evaporated from the cast film peeled from the moving support to dry the cast film to obtain a film.

The apparatus for forming a flexible film of the present invention includes a moving support, a reaching unit supporting unit, a peeling unit supporting unit, a membrane cooling unit, a support heating unit, and a membrane heating unit. The moving support body circulates through the reaching part, the flexible part, the film drying part, and the peeling part in order. The said arrival part reaches the falling dope. The said dope contains a polymer and a solvent. The flexible part forms the flexible film from the dropped dope. The membrane drying unit evaporates the solvent from the casting membrane. The said flexible film is peeled from the said peeling part. An arrival part support unit supports the said moving support body located in the said arrival part. The peeling part supporting unit supports the said moving support body located in the said peeling part. The membrane cooling unit cools the flexible membrane until the movable support moves out of the membrane dried portion and reaches the peeled portion, until it becomes self-supporting and transportable. The support heating unit heats the moving support from the peeling part until it reaches the film drying part. The membrane heating unit heats the flexible membrane before reaching the membrane drying unit by using the heat provided by the support heating means.

The support heating unit heats the moving support until it reaches the reaching part beyond the peeling part, or heats the moving support between the reaching part and the film drying part. It is desirable to.

The support heating unit preferably heats the movable support such that the flexible region for forming the flexible film set on the surface of the movable support is higher than the non-flexible region except the flexible region on the surface of the movable support. .

It is preferable that the flexible film forming apparatus is provided with the skin layer formation unit which blows a skin layer formation wind on the surface of the said flexible film, and forms a skin layer in the surface side of the said flexible film. The skin layer forming unit is provided between the support heating unit and the film drying unit.

It is preferable that the said reaching part support unit is provided with the reaching part support roller, and the said peeling part support unit is equipped with the peeling part support roller. The moving support is an endless band spanning the reaching part supporting roller and the peeling part supporting roller.

It is preferable that the said support body heating unit is equipped with the heating wind duct which makes a heating wind blow to the said moving support body.

It is preferable that the said membrane cooling unit cools the said peeling part support unit.

The said membrane cooling unit adjusts the temperature of the said moving support body in the said peeling part to 5 degreeC or more and 15 degrees C or less, The said support body heating unit has the temperature of the said moving support body in the said flexible part being 8 degreeC or more It is preferable to heat the said moving support body so that it may become below the boiling point of a solvent.

According to this invention, the time required from a film drying process to a peeling process is performed by the dope dripping process, a film drying process, and a peeling process, and the film cooling process performed between a film drying process and a peeling process. It can be shortened. And since the support body heating process which heats a moving support body is performed between this peeling process and the next film drying process, the film heating process which heats the casting film formed by the next dope dripping process from the back surface side can be performed. have. The surface of a flexible film can be smoothed by a film heating process. Thus, according to this invention, a flexible film and a film can be produced efficiently, suppressing thickness variation.

The above objects and advantages will be readily understood by those skilled in the art by reading the detailed description of the preferred embodiments with reference to the accompanying drawings.
1 is an explanatory diagram showing an outline of a solution film forming facility.
2 is a side view illustrating the outline of the first flexible unit.
3 is a perspective view showing an outline of a skin layer forming apparatus.
4 is a cross-sectional view taken along the line IV-IV showing the outline of the skin layer forming apparatus.
5 is a VV line cross-sectional view showing an outline of a skin layer forming apparatus.
6 is a perspective view showing an outline of a first support heating device.
7 is a sectional view taken along the line VII-VII showing the outline of the first support body heating device.
8 is a flowchart showing an outline of a first flexible film forming step and a solution film forming method.
9 is a cross-sectional view showing an outline of a flexible film immediately after formation.
10 is a cross-sectional view showing the outline of the cast film after the film heating step.
It is sectional drawing which shows the outline | summary of the flexible film after a skin layer formation process.
It is sectional drawing which shows the outline | summary of the cast film after a film drying process.
It is a side view which shows the outline | summary of the principal part of a 2nd flexible unit.
It is a side view which shows the outline | summary of a 3rd flexible unit.
It is a side view which shows the outline | summary of a principal part of a 4th flexible unit.
It is a side view which shows the outline | summary of a principal part of a 5th flexible unit.
It is a side view which shows the outline | summary of a 6th flexible unit.
18 is a side view illustrating an outline of a seventh flexible unit.
It is sectional drawing which shows the outline of a 2nd support body heating apparatus.
It is process drawing which shows the outline | summary of a 2nd casting film formation process and the 2nd solution film forming method.
It is a side view which shows the outline | summary of a principal part of an 8th flexible unit.

(Solution forming equipment)

As shown in FIG. 1, the solution film forming facility 10 includes a casting unit 12, a drying unit 13, and a winding unit 14.

(Flexible unit)

The flexible unit 12 makes the wet film 25 with the dope 24. The dope 24 contains the polymer (called raw material polymer) 22 used as the raw material of the film 21, and the solvent 23 of the polymer 22. As shown in FIG. The detail of the flexible unit 12 is mentioned later.

(Drying unit)

The drying unit 13 evaporates the solvent 23 from the wet film 25, and obtains the film 21 from the wet film 25. The drying unit 13 includes a clip tenter 35, a slitter 36, a drying chamber 37, and a cooling chamber 38 that are arranged in order from the flexible unit 12 toward the winding unit 14. Equipped. In the moving part 40 between the flexible unit 12 and the clip tenter 35, the belt-shaped wet film 25 sent out from the flexible unit 12 is clipped using the plurality of rollers 41. Return to 35).

The clip tenter 35 has a casing 35a, a pair of rails, a clip 35b, and a dry air supply 35c. In the casing 35a, a moving path of the wet film 25 is formed. The rails accommodated in the casing 35a are provided on both sides of the moving path of the wet film 25. The plurality of clips 35b arranged along the rail can be transferred between a gripping state holding the widthwise both edges of the wet film 25 and a release state releasing the gripping of the widthwise both edges. It is mounted to be movable. The plurality of clips 35b are annularly connected by a chain (not shown). When the clip 35b passes through the gripping start position on the rail, the clip 35b transitions from the released state to the gripping state (changes). In this way, the clip 35b grips the edge part in the width direction of the wet film 25. In addition, when the clip 35b passes through the release position on the rail, the clip 35b transitions from the grip state to the release state (changes). In this way, the clip 35b releases | grips the edge part of the width direction both sides of the wet film 25. As shown in FIG.

As the grip starts from the grip start position, the gap between the pair of rails increases. Here, the width of the wet film 25 in the holding start position is set to Wf1, and the maximum width of the wet film 25 is made Wf2 between the holding start position and the gripping release position. It is preferable that Wf2 / Wf1 is 1.05 or more and 1.5 or less. The dry air supply 35c which blows dry air into the wet film 25 is installed above and below the moving path of the wet film 25.

The slitter 36 separates the edges of the wet film 25. This separated edge portion is sent to a crusher (not shown) by blowing, finely cut, and reused as a raw material such as dope.

In the drying chamber 37, a plurality of rollers 45 are provided. The wet film 25 is conveyed while being wound by the roller 45. An adsorption recovery apparatus 46 is connected to the drying chamber 37. The adsorption recovery apparatus 46 recovers the solvent 23 evaporated from the wet film 25 by adsorption. Since the condensation point of the solvent 23 in the drying chamber 37 is adjusted within a fixed range by recovering the solvent 23 in the drying chamber 37, the wet film ( The solvent 23 is evaporated from 25). As a result, the film 21 is obtained from the wet film 25. In the cooling chamber 38, the film 21 is cooled until the temperature becomes approximately room temperature.

(Winding unit)

The winding unit 14 is equipped with the winding core 51, the winding core drive part (not shown), and the winding chamber 54 which has the press roller 52. As shown in FIG. By the control unit (not shown), the winding core drive unit rotates the winding core 51 at a predetermined speed. As a result, the film 21 is wound up by the winding core 51 by a predetermined winding tension, and becomes the film roll 55. The press roller 52 presses the film 21 wound by the winding core 51 toward the winding core 51 or the film roll 55 wound by the winding core 51. Thereby, the film 21 can be wound, preventing the mixing of air between the films 21.

It is preferable that the knurling provision apparatus 57 which forms a knurling in the width direction both edge part of the film 21 between the winding chamber 54 and the cooling chamber 38 is provided.

(The details of the flexible unit)

As shown in FIG. 2, the flexible unit 12 which produces the wet film 25 from the dope 24 is equipped with the flexible casing 75. As shown in FIG. In the flexible casing 75, the flexible die 60, the endless band 62, the skin layer forming apparatus 63, the film drying apparatus 64, the peeling roller 65, and the band moving mechanism ( 66 and the first to fourth seal members 71 to 74 are provided. The casting die 60 flows out the dope 24. The endless band 62 is a moving support body which supports the dope 24 which flowed out, and forms the casting film 61 which consists of the dope 24. The skin layer forming apparatus 63 forms a skin layer on the surface 61a of the flexible film 61. The film drying apparatus 64 evaporates the solvent 23 (see FIG. 1) from the cast film 61. The peeling roller 65 peels the casting film 61 from the endless band 62. The band moving mechanism 66 circulates and moves the endless band 62 in a predetermined direction.

(Endless band movement mechanism)

The band moving mechanism 66 is for guiding in the predetermined direction while supporting the endless band 62. The band movement mechanism 66 is equipped with each roller 66a-66c and the motor 66m which drives the roller 66c.

The rollers 66a to 66c are disposed to be parallel to each other. The roller 66b and the roller 66c are disposed on substantially the same plane (for example, a horizontal plane), and the roller 66a is disposed between the roller 66b and the roller 66c and disposed above the plane. . An annular endless band 62 formed by connecting both ends of the sheet member is wound on the rollers 66a to 66c. The band back surface 62b of the endless band 62 is supported by rollers 66a to 66c. When the roller 66c is rotated by the drive of the motor 66m, the endless band 62 is a roller 66a, a roller 66b, a roller 66c, a roller 66a,. Then, the rollers 66a to 66c are circulated and moved. In this way, the movement path 66r of the endless band 62 is formed by rollers 66a-66c.

The rollers 66x to 66z are for supporting the band back surface 62b of the endless band 62 and are disposed along the movement path 66r of the endless band 62. The roller 66x is arrange | positioned between the roller 66c and the roller 66a. The roller 66y is disposed between the roller 66a and the roller 66b, and the roller 66z is disposed between the roller 66b and the roller 66c.

It is preferable that the endless band 62 obtained by connecting both ends of a sheet | seat material is made of stainless steel, and it is more preferable that it is made of SUS316 which has sufficient corrosion resistance and strength. It is preferable that the width | variety of the endless band 62 is 1.1 times or more and 2.0 times or less of the flexible width CW (refer FIG. 6) of the dope 24, for example. It is preferable that the length of the endless band 62 is 20 m or more and 200 m or less, for example, and it is preferable that the thickness of the endless band 62 is 0.5 mm or more and 2.5 mm or less, for example. In addition, it is preferable to use the endless band 62 whose thickness variation is 0.5% or less with respect to the whole thickness. It is preferable that the band surface 62a is polished, and it is preferable that the surface roughness of the band surface 62a is 0.05 micrometer or less.

(Seal member)

The first to fourth seal members 71 to 74 are provided in the movement path 66r of the endless band 62. The first seal member 71 is disposed to face the roller 66x via the movement path 66r of the endless band 62. The second seal member 72 is disposed to face the roller 66y through the movement path 66r of the endless band 62. The third to fourth seal members 73 to 74 face the roller 66c via the moving path 66r of the endless band 62 so as to move the endless band 62 (hereinafter referred to as the X direction). It is arranged in order from the upstream side to the downstream side.

The 1st sealing member 71 consists of the windshield 71a attached to the flexible chamber 75a, and the labyrinth seal 72b attached to the windshield 71a. The windshield 71a has a windshield that blocks the flow of gas in the flexible casing 75. The windshield 71a protrudes from the inner wall surface of the flexible casing 75 and extends toward the band surface 62a of the endless band 62. The labyrinth seal 71b is provided at the tip of the windshield 71a so as to be close to the band surface 62a. The second seal member 72 to the fourth seal member 74 have the same structure as the first seal member 71.

With each roller and each seal member, the flexible casing 75 is from the upstream side to the downstream side in the X direction, and the casting chamber 75a, the film drying chamber 75b, the peeling chamber 75c, and the support heating chamber 75d. Separated by. The flexible chamber 75a is formed of the first seal member 71, the second seal member 72, the roller 66x, and the roller 66y. Similarly, the film drying chamber 75b is formed by the second seal member 72, the third seal member 73, the roller 66y and the roller 66c, and the peeling chamber 75c is the third seal member 73. ), The fourth seal member 74 and the roller 66c, and the support heating chamber 75d includes the first seal member 71, the fourth seal member 74, the roller 66c and the roller 66x. Is formed by

(Flexible room)

The flexible die 60 is installed in the flexible chamber 75a. The casting die 60 is disposed so as to face the roller 66a via the movement path 66r of the endless band 62. An arrival part is formed between the casting die 60 and the roller 66a. The casting die 60 has a slit outlet through which the dope 24 flows out at the tip. The casting die 60 is arranged so that the slit outlet is close to the portion of the endless band 62 supported by the roller 66a. The dope 24 which flowed out from the casting die 60 flows on the band surface 62a, and, as a result, becomes a band-shaped casting film 61.

It is preferable that the pressure reduction chamber 77 is provided in the flexible chamber 75a. The pressure reduction chamber 77 is provided upstream from the casting die 60 in the X direction, and is provided to be adjacent to the casting die 60. Under the control of a controller (not shown), the decompression chamber 77 decompresses the X-direction upstream side of the bead so that the pressure on the X-direction upstream side of the bead is lower than that on the X-direction downstream side of the bead. Here, a bead means what is formed by the dope 24 until it flows out from the casting die 60 and reaches the endless band 62. As shown in FIG.

(Membrane drying room)

In the film drying chamber 75b, the skin layer forming apparatus 63 for supplying the skin layer forming wind 80 to the flexible film 61 and the film drying apparatus 64 for evaporating the solvent from the flexible film 61 are upstream in the X direction. It is provided along the movement path 66r in order from the side toward the downstream side.

(Skin layer forming apparatus)

It is preferable that the skin layer forming apparatus 63 is arrange | positioned in the X direction most upstream side of the film drying chamber 75b. As shown in FIG. 3 and FIG. 4, the skin layer forming apparatus 63 arrange | positioned so that it may be adjacent to the film surface 61a has the air supply duct 81, the cover 82, the pre air supply nozzle 83, and the wind conditioner ( 84). The air supply duct 81 and the cover 82 are provided in order from the upstream side in the X direction toward the downstream side.

The air supply duct 81 flows through the skin layer forming wind 80, and is disposed close to the second seal member 72 in the X direction and spaced apart from the film surface 61a. The pre-air supply nozzle 83 is provided in the surface 81a of the membrane surface 61a side of the air supply duct 81. The pre-air supply nozzle 83 extends from the upstream in the X direction to the downstream in the X direction as it approaches the membrane surface 61a. At the tip of the pre-air supply nozzle 83, a pre-air supply mechanism 83a is opened which is opened toward the band surface 62a. As shown in FIG. 5, the pre-feed mechanism 83a is different from the endless band 62 from one end of the endless band 62 in the width direction (hereinafter referred to as Y direction) of the movement path 66r. It extends to the stage. In addition, it is preferable that the presupply mechanism 83a coincides with the surface 81a.

As shown in FIG.3 and FIG.4, the cover 82 guides the skin layer formation wind 80 sent from the pre-air supply mechanism 83a to the downstream direction X direction, and is a flexible film in the state separated from the flexible film 61. As shown in FIG. Cover 61. The cover 82 is formed in a plate shape, and in the Y direction, from the air supply duct 81 to the vicinity of the film drying apparatus 64 (for example, the film drying apparatus described later), the endless band ( It extends from one end of 62 to the other end of endless band 62. The cover 82 has a guide surface 82a substantially parallel to the membrane surface 61a on the membrane surface 61a side. In addition, it is preferable that the height of the guide surface 82a coincides with the surface 81a.

From the pre air supply mechanism 83a to the X-direction downstream end part of the cover 82, it is sent out from the pre air supply mechanism 83a between the guide surface 82a and the surface 81a, and the band surface 62a. The air passage 86 of the skin layer forming wind 80 is formed. It is preferable that the space | interval from the surface 81a to the band surface 62a is 20 mm or more and 150 mm or less, for example. The width | variety of the air path 86 in a Y direction should just be 0.8 times or more and 1 times or less of the width of the endless band 62 in a Y direction, for example. What is necessary is just to determine the length of the air path 86 in a X direction according to manufacturing conditions (moving speed V etc. of the surface 62a of the endless band 62), For example, it is preferable that they are 1000 mm or more and 5000 mm or less. Do.

The air conditioner 84 sends a skin layer forming wind 80 to the air supply duct 81 at a predetermined amount of air, and an air conditioner (not shown) that adjusts the temperature of the skin layer forming wind 80 within a predetermined range. It has a blowing fan (not shown).

The side shielding plate 85 may be provided in the skin layer forming apparatus 63. The side windshields 85 are arranged in the Y direction and extend from the X direction upstream end of the air supply duct 81 to the X direction downstream end of the cover 82. The side windshields 85 extend from the surface 81a and the guide surface 82a toward the band surface 62a. As shown in FIG. 5, it is preferable that the surface 85a of the side inner side windshield 85 of the Y direction inner side corresponds with the inner surface 83b of the pre-air supply nozzle 83. As shown in FIG.

(Membrane drying device)

As shown in FIG. 2, the film drying apparatus 64 is equipped with the front film dryer 88 and the back film dryer 89 which are provided in order from the X-direction upstream to downstream.

(Full membrane dryer)

The membrane dryer 88 is arrange | positioned along the part which moves to the roller 66b from the roller 66y among the movement paths 66r of the endless band 62. As shown in FIG. The front film drier 88 is disposed on the surface of the band surface 62a and is disposed on the surface side blower 91 for transmitting the total drying air 90, and is disposed on the side of the band back surface 62b so that the entire drying air 90 can be removed. It has a back side blower 92 which sends out, and an all dry-winding regulator (not shown).

(Surface blower)

The surface side blower 91 is provided with an air supply duct (not shown) and an exhaust duct (not shown). The air supply port of the air supply duct and the air exhaust port of the exhaust duct face the band surface 62a. In addition, the air supply port of the air supply duct and the air exhaust port of the exhaust duct extend from one end of the flexible membrane 61 to the other end. In addition, the air supply port of the air supply duct and the air exhaust port of the exhaust duct are preferably arranged alternately in the X direction.

(Back side blower)

The back side blower 92 is provided with an air supply duct (not shown) and an exhaust duct (not shown) similarly to the surface side blower 91. The air supply port of the air supply duct and the air exhaust port of the exhaust duct face the band back surface 62b. In addition, the air supply port of the air supply duct and the air exhaust port of the exhaust duct extend from one end of the flexible membrane 61 to the other end. It is preferable that the air supply port of the air supply duct and the air exhaust port of the exhaust duct are alternately arranged in the X direction.

The all-dried wind regulator is a temperature controller (not shown) which adjusts the temperature of the all-dried wind 90 within a predetermined range, and a blowing fan that sends the all-dried wind 90 to the air supply duct at a predetermined amount of air (not shown). Has

The surface side blower 91 blows out all the drying air 90 toward the membrane surface 61a from the air supply port, and sucks all the drying air 90 from the exhaust port. Similarly, the back side blower 92 blows out all the drying air 90 toward the band back surface 62b by the air supply port, and draws in all the drying air 90 from the exhaust port.

In addition, the surface side blower 91 may blow all the drying air 90 in the vertical direction with respect to the membrane surface 61a. Similarly, the back side blower 92 may blow all the dry air 90 in the vertical direction with respect to the band back surface 62b.

(After membrane dryer)

As shown in FIG. 2, the thick film dryer 89 is arrange | positioned along the part which goes to the roller 66c from the roller 66b among the movement paths 66r of the endless band 62. As shown in FIG. The thick film dryer 89 is disposed on the band surface 62a side, and is provided with a parallel blower 95 for sending the post drying air 94, and a back blower 96 disposed on the band back surface 62b side. And a dry air conditioner (not shown). The parallel blower 95 is provided in order from the upstream side to the downstream direction in the X direction, and has the parallel exhaust duct 95a and the parallel air supply duct 95b.

The parallel exhaust duct 95a and the parallel air supply duct 95b are arrange | positioned at the band surface 62a side, respectively. In the parallel exhaust duct 95a, an exhaust port for exhausting the post-drying air 94 is provided. The exhaust port opened toward the downstream in the X direction is provided extending from one end of the endless band 62 to the other end in the Y direction. In the parallel air supply duct 95b, the air supply port through which the post-drying air 94 is sent out is provided. The air supply port opened toward the upstream side in the X direction extends from one end of the flexible membrane 61 to the other end.

The back side blower 96 has the structure similar to the back side blower 92 except sending out the after drying air 94. FIG. The post-drying air conditioner (not shown) includes an air conditioner (not shown) for adjusting the temperature of the post-drying air 94 in a predetermined range, and the rear-side blower 96 controls the post-drying air 94 at a predetermined amount of air. And a blowing fan (not shown) sent to the air supply duct or the parallel air supply duct 95b.

(Peeling room)

The peeling roller 65 is provided in the peeling chamber 75c. A peeling part is formed between the peeling roller 65 and the roller 66c. The peeling roller 65 is connected with the motor 99. Moreover, the outlet 75o of the flexible casing 75 is opened in the peeling chamber 75c. By making the circumferential speed of the peeling roller 65 larger than the roller 66c, the flexible film 61 can be peeled from the endless band 62. FIG. The flexible film 61 peeled from the endless band 62 becomes the wet film 25, and is sent out from the outlet 75o to the drying unit 13 (refer FIG. 1).

(Support heating room)

The support body heating device 111 which sends the heating wind 110 to the endless band 62 is provided in the support body heating chamber 75d. The support body heating apparatus 111 has the surface side heater 112 arrange | positioned at the band surface 62a side, the back side heater 113 arrange | positioned at the band back surface 62b side, and the heating wind regulator 114. . In addition, you may abbreviate | omit either one of the front-side heater 112 and the back-side heater 113.

(Surface heater)

As shown to FIG. 6 and FIG. 7, the surface side heater 112 has an air supply duct 112a and an exhaust duct (not shown). The air supply port 112o of the air supply duct 112a and the air exhaust port of the exhaust duct face the band surface 62a. The air supply port 112o and the exhaust port extend from one end of the endless band 62 to the other end, respectively. That is, in the Y direction, the width of the air supply port 112o and the exhaust port is wider than the flexible width CW. In addition, the air supply port 112o and the exhaust port are preferably arranged alternately in the X direction.

(Back side heater)

The back side heater 113 has an air supply duct 113a and an exhaust duct (not shown). The air supply port 113o of the air supply duct 113a and the air exhaust port 113i of the exhaust duct face the band back surface 62b. The air supply port 113o and the exhaust port 113i extend from one end of the endless band 62 to the other end, respectively. That is, in the Y direction, the width of the air supply port 113o and the exhaust port 113i is wider than the flexible width CW. In addition, the air supply port 113o and the exhaust port 113i are preferably arranged alternately in the X direction.

The heating wind controller 114 is a temperature controller (not shown) which adjusts the temperature of the heating wind 110 within a predetermined range, and the heating wind 110 at a predetermined amount of air, the surface-side heater 112 and the rear surface side. A blowing fan (not shown) is sent to the air supply ducts 112a and 113a of the heater 113.

The surface side heater 112 sends the heating wind 110 toward the band surface 62a from the air supply port 112o, and sucks the heating wind 110 through the exhaust port. The back side heater 113 sends the heating wind 110 toward the band back surface 62b from the air supply port 113o, and sucks the heating wind 110 through the exhaust port 113i.

Returning to FIG. 2, the roller warmer 121 which adjusts the temperature of the roller 66a is connected to the roller 66a. The roller warmer 122 which adjusts the temperature of the roller 66b is connected to the roller 66b. Thereby, the roller 66b evaporates a solvent from the casting film 61 by heating of the casting film 61. In this case, the roller 66b may be included in the film drying apparatus 64. The roller heater 123 which cools the roller 66c is connected to the roller 66c. When the roller heater 123 cools the roller 66c, the roller 66c functions as film cooling means for cooling the casting film 61 through the endless band 62.

Although not shown in the drawings, a gaseous solvent is provided in the flexible casing 75 by providing a condensation apparatus for condensing the solvent contained in the atmosphere in the flexible casing 75 and a recovery apparatus for recovering the condensed solvent. The temperature (condensation point) at which the liquid is liquefied can be maintained in a predetermined range.

Next, as shown in FIG. 8, in the solution film forming method 125, the casting film formation process 126 and the wet film drying process 127 are performed in order.

(Summary of Flexible Film Forming Process)

The casting film formation process 126 which obtains the wet film 25 from the dope 24 is performed in the casting unit 12 shown in FIG. The detail of the flexible film formation process 126 is mentioned later.

(Wet Film Drying Process)

The wet film drying process 127 which evaporates a solvent from the wet film 25 and uses it as the film 21 is performed in the drying unit 13 shown in FIG.

The wet film 25 introduced into the clip tenter 35 is conveyed in a state where the widthwise both ends are gripped by the clip 35b. The dry wind supply 35c applies predetermined drying wind to each of the front and rear surfaces of the wet film 25 between the grip start position and the grip release position. In this way, the solvent can be evaporated from the wet film 25. Moreover, since the space | interval of a rail increases from a holding | grip start position toward a holding | grip release position, it can carry out an extending | stretching process with respect to the wet film 25 by conveyance by the clip 35b. By extending | stretching process, adjustment of in-plane retardation Re and thickness direction retardation Rth becomes possible.

The wet film 25 introduced into the drying chamber 37 is conveyed while being wound by the plurality of rollers 45. By adjusting the temperature and humidity of the atmosphere in the casing 106a, the solvent evaporates from the wet film 25 conveyed in the casing 106a. In this way, the wet film 25 becomes the film 21.

(Details of Flexible Film Forming Process)

As shown in FIG. 8, in the flexible film formation process 126, the dope dripping process 131, the casting process 132, the film heating process 133, the skin layer formation process 134, and a film drying process The 135, the film cooling process 136, the peeling process 137, and the support body heating process 138 are performed in order.

As shown in FIG. 2, when the roller 66c rotates by the drive of the motor 66m, the endless band 62 will circulate and move each chamber 75a-75d in the casing 75 in order. . By the roller temperature controllers 121-123, the temperature of the rollers 66a-66c is adjusted to a predetermined range. In a stock tank (not shown), the temperature of the dope 24 is regulated substantially constant in a predetermined range. The dope 24 is sent from the stock tank to the casting die 60 by the pump which is not shown in figure. By the temperature controller installed in the casting die 60, the temperature of the casting die 60 is adjusted substantially constant in a predetermined range.

(Flexible room)

In the flexible chamber 75a, the flexible film 61 which consists of the dope fall process 131 (refer FIG. 8) which the dope 24 which flowed out from the casting die 60 reaches on the band surface 62a, and the dope 24. FIG. ) Is formed on the band surface 62a, and a casting step 132 (see FIG. 8) and a film heating step 133 (see FIG. 8) for heating the casting film 61 are performed.

(Dope falling process)

The casting die 60 continuously flows the dope 24 from the slit outlet toward the band surface 62a. The dope 24 flowing out of the slit outlet reaches a portion of the endless band 62 supported by the roller 66a, that is, the arrival position DP on the band surface 62a.

(Flexible process)

Since the endless band 62 is in a moving state, the dope 24 having reached the arrival position DP flows in the moving direction on the band surface 62a and extends. In this way, on the band surface 62a, the flexible film 61 which consists of dope 24, and has the flexible width CW (refer FIG. 6) is formed in strip shape.

It is preferable that the moving speed V of the endless band 62 is 200 m / min or less. When the moving speed V exceeds 200 m / min, it becomes difficult to form a bead stably. The lower limit of the moving speed V may consider productivity of the target film. The moving speed V may be, for example, 20 m / min or more, or 60 m / min or more.

It is preferable that content of the solvent in the dope 24 flowing out from the casting die 60 is 300 mass% or more and 450 mass% or less. This is because if the content of the solvent in the dope 24 flowing out of the casting die 60 is less than 300 mass%, the viscosity of the dope 24 becomes high and stable casting cannot be performed. If the content of the solvent in the dope 24 flowing out from the casting die 60 exceeds 450 mass%, the drying load in the film drying chamber 75b becomes large, and as a result, production efficiency falls, which is not preferable. not.

Here, content of a solvent shows the quantity of the solvent contained in a dope, a flexible film, or each film on a dry basis, and takes a sample from the target film, x is the weight of this sample, and y is the weight after drying a sample. When expressed as ｛(xy) / y｝ times 100.

The temperature of the dope 24 which flows out from the casting die 60 is 20 degreeC or more, and it is preferable that it is below the boiling point of a solvent. When the temperature of the dope 24 which flows out from the casting die 60 is less than 20 degreeC, the viscosity of the dope 24 becomes high and it becomes impossible to perform stable casting | flow_spread. Moreover, when the temperature of the dope 24 which flows out from the casting die 60 exceeds the boiling point of a solvent, since foaming of dope 24 arises, it is unpreferable. In addition, the boiling point of a solvent shows the boiling point of the said compound, when a solvent consists of a single compound, and shows the lowest boiling point of the some compound, when a solvent consists of a some compound.

(Membrane heating process)

Since the 2nd sealing member 72 and the roller 66y are separated by the predetermined distance toward the X direction downstream from the reaching part, the flexible zone (flexible part) of the predetermined length toward the X direction downstream from the reaching part ( CZ) is formed. In the casting zone CZ, the film heating step 133 for heating the casting film 61 is performed using the endless band 62 heated by the support body heating step 138 described later as the film heating means.

Here, the film surface 61a of the flexible film 61 immediately after formation, ie, immediately after the casting process 132, is not smooth (refer FIG. 9). Therefore, the thickness variation arises in the casting film 61 immediately after the casting process 132. This thickness variation is considered to be due to the vibration of the beads. Moreover, the dope 24 which comprises the casting film 61 immediately after the casting process 132 contains a large amount of solvent, and it is easy to show fluidity. Therefore, in this invention, the film heating process 133 which heats the casting film 61 immediately after the casting process 132 using the heated endless band 62 is performed. By heating the casting film 61 immediately after the casting step 132, the fluidity of the dope 24 forming the casting film 61 immediately after formation is increased, and as a result, the film surface of the casting film 61 immediately after formation ( 61a) becomes smooth (refer FIG. 10).

The length of the casting zone CZ in the X direction is not particularly limited, and the length of the casting zone CZ may be sufficient to ensure the time required until the film surface 61a of the casting film 61 immediately after formation is smooth. It is preferable to perform the film heating process 133 with respect to the flexible film 61 whose content of a solvent is 300 mass% or more and 450 mass% or less.

By the roller heater 121, the temperature of the roller 66a becomes in the range below the boiling point of the solvent more than the temperature of the band surface 62a in the peeling position PP.

(Membrane drying room)

In the film drying chamber 75b, the skin layer forming wind 80 is blown through the film surface 61a until the skin layer 61x (see FIG. 11) is formed on the film surface 61a side of the flexible film 61. The skin layer forming process 134 (refer FIG. 8) and the film drying process 135 (refer FIG. 8) which evaporate a solvent from the casting film 61 are performed.

(Skin layer formation process)

As shown in FIG. 4, in the skin layer forming apparatus 63, the air supply nozzle 83 sends the skin layer forming wind 80 from the inlet port 83a. The angle? It is more preferable that it is 45 degrees. The cover layer 82 guides the skin layer forming wind 80 sent out from the inlet port 83a from the upstream side in the X direction to the downstream side. By the cover 82 proximate to the casting film 61, in the vicinity of the film surface 61a of the casting film 61, the vortic flow of the skin layer forming wind 80 easily occurs. In the place where the vortic flow is generated, since the heat energy of the skin layer forming wind 80 is easily transmitted to the flexible film 61, the vortic flow of the skin layer forming wind 80 causes the At the membrane surface 61a, evaporation of the solvent is promoted.

By the skin layer formation process 134, the flexible film 61 has the skin layer 61x and the wet layer 61y (refer FIG. 11). The skin layer 61x is a portion which is formed on the film surface 61a side of the flexible film 61 and is dried compared with the wet layer 61y located on the endless band 62 side than the skin layer 61x. Therefore, the content of the solvent of the skin layer 61x is lower than that of the wet layer 61y.

The surface of the skin layer 61x is formed smoothly. When the film drying step 135 is performed on the flexible film 61 having the skin layer 61x, the surface of the skin layer 61x becomes the film surface 61a of the obtained flexible film 61. Therefore, the skin layer formation process 134 is performed with respect to the flexible film 61 which passed through the film heating process 133, and the flexible film 61 with which the film surface 61a is smooth can be obtained.

It is preferable to perform the skin layer formation process 134 with respect to the flexible film 61 whose content of a solvent is 250 mass% or more and 400 mass% or less. It is preferable that the temperature of the skin layer formation wind 80 is 30 degreeC or more and 80 degrees C or less, for example. Moreover, it is preferable that the wind speed of the skin layer formation wind 80 is 5 m / sec or more and 25 m / sec or less.

(Film drying process)

In the film drying step 135, the pre-film drying step 135a and the post-film drying step 135b are performed in this order (see FIG. 8).

(Film drying process)

As shown in FIG. 2, the whole film drier 88 performs the whole film drying process 135a which evaporates a solvent from the casting film 61. As shown in FIG. The surface side blower 91 blows the pre-drying air 90 to the membrane surface 61a, and evaporates the solvent from the flexible membrane 61. Moreover, the back side blower 92 blows all dry air 90 to the band back surface 62b, and heats the flexible film 61 through the endless band 62. As shown in FIG. By heating of the casting film 61, the solvent is evaporated from the casting film 61.

(Thick film drying process)

After the film drier 89 evaporates the solvent from the casting film 61, the film drier 89 performs a film drying step 135b. The parallel blower 95 flows the post-drying air 94 into the film surface 61a of the flexible membrane 61, and evaporates the solvent from the flexible membrane 61. Moreover, the back side blower 96 blows back dry air 94 on the band back surface 62b, and heats the casting film 61 through the endless band 62. As shown in FIG. By heating of the casting film 61, the solvent is evaporated from the casting film 61. It is preferable that the after-film drying process 135b is performed until content of the solvent of the casting film 61 is 110 mass% or more and 210 mass% or less.

You may perform the post film drying process 135b using the heat of the roller 66b. It is preferable to adjust the roller heater 122 so that the temperature of the roller 66b may be in the range of 20 degreeC or more and 40 degrees C or less.

By carrying out the respective steps 131 to 135 (see FIG. 8), a flexible film 61 having a smooth film surface 61a can be obtained (see FIG. 12).

(Peeling room)

In the peeling chamber 75c, the film cooling process 136 (refer FIG. 8) which cools the endless band 62, and the peeling process 137 which peels the flexible film 61 from the endless band 62 (refer FIG. 8). ) Is performed.

(Film cooling process)

By the roller temperature controller 123, the temperature of the roller 66c becomes in the range of -10 degreeC or more and 15 degrees C or less. Moreover, it is preferable that the temperature of the roller 66c exists in the range of -10 degreeC or more and 10 degrees C or less. The endless band 62 which became high temperature by the film drying process 135 is cooled by the contact with the roller 66c. Then, the flexible membrane 61 is cooled through the cooled endless band 62. The film cooling process 136 is performed until it becomes a state which can be independent and conveyed.

(Peeling process)

In the peeling chamber 75c, the peeling process 137 (refer FIG. 8) which peels the flexible film 61 which became the peelable state from the endless band 62 using the peeling roller 65 is performed. In the part (peel position PP) of the endless band 62 supported by the roller 66c, the flexible film 61 which became the peelable state is peeled from the endless band 62. As shown in FIG. The cast film 61 peeled from the endless band 62 is sent out from the outlet 75o as the wet film 25. In order to suppress the dispersion | variation of an orientation angle, it is preferable to perform the peeling process 137 with respect to the flexible film 61 whose content of a solvent is 200 mass% or less. It is preferable to perform the peeling process 137 with respect to the casting film 61 of 100 mass% or more from a viewpoint of a production efficiency.

(Support heating process)

The endless band 62 after the casting film 61 is peeled off returns to the casting chamber 75a via the support heating chamber 75d. The dope dripping step 131, the casting step 132, and the skin layer forming step 134 are successively performed on the endless band 62 cooled by the film cooling step 136. In this non-smooth state (refer FIG. 9), drying advances. As a result, thickness variation occurs in the flexible film 61. Since the thickness deviation which arose in the flexible film 61 cannot be eliminated at a later process, it will become the thickness deviation of the film 21 finally.

Therefore, in this invention, in order to perform the film heating process 133 between the (n + 1) th casting process 132 and the (n + 1) th skin layer formation process 134, the nth peeling process ( The support body heating process 138 which heats the endless band 62 is performed between 137) and the (n + 1) times dope falling process 131. As shown in FIG.

In the support heating chamber 75d, the support heating device 111 performs a support heating step 138 in which the endless band 62 is heated. As shown in FIG. 6, the surface side heater 112 blows the heating wind 110 into the band surface 62a, and the endless band 62 is opened until the temperature of the band surface 62a becomes a predetermined range. Heat. Similarly, the back heater 113 blows the heating wind 110 onto the band back surface 62b, and heats the endless band 62 until the temperature of the band back surface 62b is within a predetermined range.

In the support body heating step 138, it is preferable to heat the band surface 62a so that the temperature of the band surface 62a in the casting zone CZ is in the range T1. Here, range T1 is 8 degreeC or more and below the boiling point of a solvent, It is preferable that it is 10 degreeC, and, as for the lower limit of range T1, it is more preferable that it is 15 degreeC. It is preferable that the upper limit of range T1 is (boiling point of a solvent -5 degreeC). Moreover, it is preferable that the temperature of components (rollers 66a, 66x, etc.) which function with a support body heating apparatus is also the range T1.

In the present invention, heat is applied to the flexible film 61 formed on the endless band 62 by the following casting step 132 by using the heat applied to the endless band 62 in the support heating step 138. The film heating step 133 is performed. Therefore, according to this invention, a film can be manufactured efficiently, suppressing thickness variation.

In addition, what is necessary is just to perform said film heating process 133 between peeling position PP and arrival position DP.

Next, another embodiment of the present invention will be described. Parts and members that are the same as those in the above embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted, and detailed descriptions of parts different from the above embodiments will be given.

As a support body heating means, although the support body heating device 111 which blows the heating wind 110 into at least one of the band surface 62a and the band back surface 62b was used, this invention is not limited to this, The band surface 62a And the support heating device 141 provided with a heating roller in contact with at least one of the band back surfaces 62b. As shown in FIG. 13, the support body heating device 141 includes a surface heating roller 142 in contact with the band surface 62a, a back surface heating roller 143 in contact with the band back surface 62b, and a surface heating roller. 142 and a roller temperature controller 144 for adjusting the temperature of the back surface heating roller 143. By the roller temperature controller 144, the support body heating apparatus 141 heats the band surface 62a so that the temperature at the time of passage of the casting zone CZ (refer FIG. 2) will be the range T1.

As shown in FIG. 2, the roller temperature controller 123 may cool the roller 66z arrange | positioned downstream of the X film | membrane downstream of the film dryer 89. As shown in FIG. The roller 66z cooled by the roller heater 123 becomes a membrane cooling means. Therefore, the film cooling step 136 may be performed in the film drying chamber 75b after the film drying step 135.

In the said embodiment, although the roller 66c cooled by the roller heater 123 was used as film cooling means, this invention is not limited to this. As shown in FIG. 14, you may use the cooling unit 148 which cools the endless band 62 until it reaches the peeling position PP as membrane cooling means. In the film drying chamber 75b, the cooling unit 148 disposed between the rear film dryer 89 and the cooling roller 66c includes a liquid supply device 149 for supplying liquid to the band back surface 62b, and a band back surface. The drying air 150 is made to flow 62b, and the evaporation apparatus 151 which evaporates a liquid is provided. The supply method of the liquid by the liquid supply apparatus 149 may be any of methods, such as application | coating, spraying, and the method of spraying a droplet form. The liquid supply device 149 and the evaporation device 151 are sequentially disposed on the band back surface 62b side from the upstream side in the X direction toward the downstream side along the movement path 66r of the endless band 62. The liquid supply device 149 supplies liquid to the band back surface 62b. In the evaporation apparatus 151, when the drying wind 150 is made to flow on the back surface of the band 62b, the liquid on the back surface of the band 62b is evaporated. When the liquid on the band back surface 62b has evaporated, the temperature of the band back surface 62b is reduced by the heat of vaporization of the liquid. In this way, the endless band 62 can be cooled using the cooling unit 148.

The liquid may be evaporated until the endless band 62 reaches the peeling position PP. For example, dichloromethane or the like can be used.

As the film cooling means, at least one of the rollers 66c and 66z and the cooling unit 148 may be used, and two of the rollers 66c and 66z and the cooling unit 148 may be combined, and all three characters may be used. You may use it.

In order to keep the band surface 62a horizontal in the casting zone CZ, it is preferable to arrange the roller 66a and the roller 66x in the same horizontal plane. 15, the support roller 66d may be provided between the roller 66a and the roller 66y on the same horizontal plane as the roller 66a and support the band back surface 62b.

Moreover, as shown in FIG. 16, you may provide the support roller 66e arrange | positioned at the same horizontal surface as the roller 66a, and support the band back surface 62b between the roller 66a and the roller 66x. By the roller temperature controller 121, you may adjust so that the temperature of the support roller 66e may become the range T1. Thereby, the support roller 66e functions as a support body heating means.

Moreover, you may adjust so that the temperature of the roller 66a may become the range T1 by the roller temperature controller 121. FIG. Thereby, the roller 66a functions as a support body heating means.

In the said embodiment, although the roller 66a was arrange | positioned above roller 66x-66y, this invention is not limited to this. For example, as shown in FIG. 17, the roller 66a and the roller 66b are provided on the same plane (for example, a horizontal surface), and the roller arrange | positioned between the roller 66a and the roller 66b. You may install 66c below the said plane. In addition, you may provide the roller 66z between the roller 66a and the roller 66b.

Moreover, although the roller 66c shown in FIG. 2 has the function of supporting the endless band 62 in the peeling position PP, and the sealing function by the 3rd-4th seal members 73-74, You may isolate these functions. For example, the rollers 66c, 66f, 66g of FIG. 18 correspond to the roller 66c shown in FIG. And the roller 66c of FIG. 18 has the function of supporting the endless band 62 in the peeling position PP, and the support roller 66f of FIG. 18 is made by the 3rd sealing member 73. As shown in FIG. The sealing function is exhibited, and the support roller 66g of FIG. 18 exhibits the sealing function by the 4th sealing member 74. As shown in FIG. The roller warmer 123 cools the roller 66c. The roller heater 123 may cool the roller 66f.

The roller 66g may be heated by the roller heater 123. Thereby, the roller 66g functions as a support body heating means.

In addition, the roller 66a shown in FIG. 17 is corresponded that the roller 66a, 66x, 66y shown in FIG. 2 was integrated.

Moreover, as shown in FIG. 18, the roller 66a and the roller 66c are provided on the same plane (for example, a horizontal surface), and the roller 66b is provided between the roller 66a and the roller 66c. You may install it. The roller 66b which supports the band back surface 62b is arrange | positioned so that the endless band 62 which moves toward the roller 66c from the roller 66a may be substantially horizontal. In addition, the roller 66b may be provided above the roller 66a and the roller 66c. The roller 66a shown in FIG. 18 corresponds to what the rollers 66a, 66x, 66y shown in FIG. 2 integrated.

In the said embodiment, in the support body heating process 138, although the endless band 62 was heated in the whole Y direction, only the center part of the Y direction in the endless band 62 may be heated. Moreover, you may heat only the part of flexible area | region CA (refer FIG. 6) of casting width CW (refer FIG. 19). Thereby, since the non-flexible area | region except the flexible area | region CA (refer FIG. 6) of the endless band 62 is not heated more than necessary, in the film drying process 135, the quantity of Y-direction of the flexible film 61 in the film drying process 135 is carried out. Foaming at the edges can be suppressed reliably. Moreover, you may make the center part of a Y direction of a casting area | region CA a heating part, and the both ends of a Y direction part of a casting area | region CA may be a non-heating part. In this case, the width of the non-heated portion in the Y direction is 10 mm, for example.

In addition, you may perform the support surface washing process which wash | cleans the band surface 62a between the peeling process 137 and the support body heating process 138. By a support surface washing process, peeling failure can be suppressed reliably. Moreover, the foreign material (for example, a part of peeled cast film | membrane which peeled off) remaining in the band surface 62a can be removed by a support surface washing process. This foreign matter causes vibration of the beads. Therefore, the bead vibration can be prevented by the support surface cleaning process. In order to clean the band surface 62a, for example, it is preferable to use a dry ice washer that sprays dry ice on the band surface 62a.

Moreover, you may perform the contact angle fall process of reducing the contact angle of the band surface 62a with respect to dope 24 between support body heating process 138 and the following dope dripping process 131. FIG. By the contact angle lowering step, the accompanying air is less likely to flow between the bead and the band surface 62a. Therefore, it is possible to prevent the flexible film from being torn due to the inflow of the accompanying wind by the contact angle lowering step. Here, the companion wind refers to wind generated in the vicinity of the band surface 62a by the movement of the endless band 62 and flowing toward the X direction. In order to reduce the contact angle of the band surface 62a with respect to the dope 24, it is preferable to apply a solvent to the band surface 62a. The solvent used for a contact angle fall process may be the same component as the solvent 23, and may contain the component common with the solvent 23. As shown in FIG.

In the said embodiment, although the timing which performs the support body heating process 138 was made between the peeling process 137 and the dope dripping process 131, it may be between the casting | flow_spread process 132 and the membrane heating process 133. . 20 shows a flexible film forming step 161 which performs the support heating step 138 between the casting step 132 and the film heating step 133, and a solution forming method 162 having the flexible film forming step 161. Indicates.

The casting unit 165 which performs the casting film formation process 161 is shown in FIG. The flexible unit 165 has the support body heating device 168 which is a support body heating means in the band back surface 62b side of the casting zone CZ. The support body heating device 168 has a back side heater 113 and a heating wind controller 114. Since the support body heating device 168 heats the endless band 62 from the band back surface 62b side, the casting film 61 is heated from the endless band 62 side. Therefore, according to the support body heating device 168, the casting film 61 can be heated while suppressing the formation of the skin layer on the casting film 61. When performing a support body heating process in the casting zone CZ, it is necessary to heat the endless band 62 from the band back surface 62b side. This is because the skin layer forming step 134 is performed before the film heating step 133 when the endless band 62 is heated from the band surface 62a side. In addition, the roller temperature controller 121 may make the roller 66y function as a support body heating means by making the temperature of the roller 66y into the range T1.

In addition, in order to prevent evaporation of the solvent from the casting film 61 in the film heating step 133, the gas concentration of the solvent in the atmosphere near the casting film 61 in the film heating step 133 is a skin layer formation. It is preferable that it is higher than the gas concentration of the solvent of the atmosphere of the casting film 61 in the process 134. Here, "the gas concentration of the solvent in the atmosphere of temperature Ta" means "(mass of the gaseous solvent contained in the atmosphere of temperature Ta) / (saturation state in the atmosphere of temperature Ta). Mass of the solvent in the form of gas).

In the flexible film formation step 161, the timing for performing the support surface cleaning step or the contact angle lowering step may be any other time between the peeling step 137 and the next dope dropping step 131. When performing both processes, it is preferable to carry out in order of a support surface washing process and a contact angle fall process.

Moreover, you may perform the contact angle fall process of reducing the contact angle of the band surface 62a with respect to dope 24 between support body heating process 138 and the following dope dripping process 131. FIG. By the contact angle lowering step, the accompanying air is less likely to flow between the bead and the band surface 62a. Therefore, it is possible to prevent the flexible film from being torn due to the inflow of the accompanying wind by the contact angle lowering step. Here, the companion wind refers to the wind generated near the band surface 62a by the movement of the endless band 62 and flowing toward the X direction. In order to reduce the contact angle of the band surface 62a with respect to the dope 24, it is preferable to apply a solvent to the band surface 62a. The solvent used for a contact angle fall process may be the same component as the solvent 23, and may contain the component common with the solvent 23. As shown in FIG.

The film 21 obtained by this invention can be used especially for a retardation film and a polarizing plate protective film.

It is preferable that they are 600 mm or more and 3000 mm or less, and, as for the width | variety of the film 21, it is more preferable that they are 2000 mm or more and 3000 mm or less. Moreover, even if the width | variety of the film 21 exceeds 3000 mm, this invention can be applied. It is preferable that it is 20 micrometers or more and 120 micrometers or less, and, as for the film thickness of the film 21, it is more preferable that they are 30 micrometers or more and 80 micrometers or less.

Moreover, it is preferable that in-plane retardation Re of the film 21 is 10 nm or more and 300 nm or less, and it is preferable that the thickness direction retardation Rth of the film 21 is -100 nm or more and 300 nm or less.

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

Re = | n1-n2 | × d

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

The measuring method of thickness direction retardation Rth is as follows. The sample film was humidified for 2 hours at a temperature of 25 ° C. and a humidity of 60% (RH), while tilting the film surface and the value measured from the vertical direction at 632. 8 nm with an lipometer (M150 Nihon Bunco Co., Ltd.). It calculates according to the following formula from the extrapolation value of the retardation value measured similarly.

Rth = ｛(n1 + n2) / 2-n3｝ × d

n3 represents the refractive index of the thickness direction.

(Polymer)

In the said embodiment, the polymer used as a raw material of a polymer film is not specifically limited. When performing a solution film forming method, a cellulose acylate, a cyclic polyolefin, etc. are mentioned as a polymer, for example. On the other hand, when performing a solution film forming method, a cellulose acylate, a lactone ring containing polymer, a cyclic polyolefin, polycarbonate etc. are mentioned as a raw material polymer, for example. Among them, preferred are cellulose acylates and cyclic polyolefins. Among them, preferred are cellulose acylates including acetate groups and propionate groups, and cyclic polyolefins obtained by addition polymerization, and more preferably cyclic polyolefins obtained by addition polymerization.

(Cellulose acylate)

As cellulose acylate, triacetyl cellulose (TAC) is particularly preferable. And in a cellulose acylate, it is more preferable that the ratio which esterifies the hydroxyl group of a cellulose with carboxylic acid, ie, the substitution degree of an acyl group, satisfy | fills all of following formula (I)-(III). In the following formulas (I) to (III), A and B represent a degree of substitution of an acyl group, A is a degree of substitution of an acetyl group, and B is a substitution of an acyl group having 3 to 22 carbon atoms. It is also. Moreover, it is preferable that 90 weight% or more of TAC is 0.1 mm-4 mm of particle | grains.

(I) 2.0≤A + B≤3.0

(II) 0≤A≤3.0

(III) 0≤B≤2.9

The beta-1,4 bonded glucose unit which comprises cellulose has free hydroxyl groups in 2nd, 3rd, and 6th positions. A cellulose acylate is a polymer (polymer) which esterified some or all of these hydroxyl groups with the acyl group of 2 or more carbon atoms. Acyl substitution degree means the ratio (100% esterification is substitution degree 1) in which the hydroxyl group of a cellulose esterifies in 2nd, 3rd, and 6th positions, respectively.

As for all acylation substitution degree, ie, DS2 + DS3 + DS6, 2.00-3.00 are preferable, More preferably, it is 2.22-2.90, Especially preferably, it is 2.40-2.88. Moreover, as for DS6 / (DS2 + DS3 + DS6), 0.28 or more are preferable, More preferably, it is 0.30 or more, Especially preferably, it is 0.31-0.34. Here, DS2 is the substitution degree by the acyl group of the hydroxyl group of 2nd position of a glucose unit (henceforth "acyl substitution degree of 2nd position"), and DS3 is the substitution degree by the acyl group of the hydroxyl group of 3rd position (hereinafter, "3 DS6 is a substitution degree (henceforth "acyl substitution degree of 6th position") by the acyl group of the hydroxyl group of a 6th position.

Only one kind of acyl group may be used for the cellulose acylate of the present invention, or two or more kinds of acyl groups may be used. When using two or more types of acyl groups, it is preferable that one is an acetyl group. When the sum of substitution degree by hydroxyl groups of 2nd, 3rd and 6th position is DSA, and the sum of substitution degree by acyl groups other than acetyl group of 2nd, 3rd and 6th hydroxyl group is DSB, The value is more preferably 2.22 to 2.90, and particularly preferably 2.40 to 2.88. Moreover, DSB is 0.30 or more, Especially preferably, it is 0.7 or more. The DSB is 20% or more of the substituents of the 6-position hydroxyl group, but more preferably 25% or more are substituents of the 6-position hydroxyl group, 30% or more is more preferable, in particular 33% or more are substituents of the 6-position hydroxyl group desirable. Moreover, the cellulose acylate whose substitution degree of the 6th-position hydroxyl group of a cellulose acylate is 0.75 or more, 0.80 or more, especially 0.85 or more is mentioned. Soluble preferable solution (dope) can be produced by such a cellulose acylate. In particular, in a non-chlorine-based organic solvent, a good solution can be produced. Furthermore, the viscosity is low and the solution with good filterability can be manufactured.

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

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

(solvent)

As a solvent 23 for preparing dope, aromatic hydrocarbons (for example, benzene, toluene, etc.), halogenated hydrocarbons (for example, dichloromethane, chlorobenzene, etc.), alcohols (for example, methanol, ethanol, n Propanol, n-butanol, diethylene glycol and the like), ketones (e.g. acetone, methyl ethyl ketone, etc.), esters (e.g. methyl acetate, ethyl acetate, propyl acetate, etc.) and ethers (e.g. Tetrahydrofuran, methyl cellosol part, etc.) etc. are mentioned. In addition, in this invention, dope means the polymer solution and dispersion liquid obtained by melt | dissolving or disperse | distributing a polymer in a solvent.

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

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

In addition, the detail of a cellulose acylate is described in the paragraph [0195]-the paragraph [0195] of Unexamined-Japanese-Patent No. 2005-104148. Such a description is also applicable to this invention. Moreover, the additives, such as a solvent and a plasticizer, a deterioration inhibitor, a ultraviolet absorber (UV agent), an optically anisotropic control agent, a retardation control agent, a dye, a mat agent, a peeling agent, and a peeling accelerator, are similarly JP-A-2005-104148 It is described in detail in paragraph [0516] to paragraph [0516].

According to the present invention, a simultaneous lamination shared lead in which a joining dope formed by joining two or more types of dope is flexible, or a sequential lamination shared lead in which a plurality of dopes are covalently laminated and laminated in order can be performed. In addition, you may combine both covalent lead. When performing simultaneous lamination sharing, a flexible die with a feed block may be used, or a multi-pocket flexible die may be used.

The layer on the support side of the flexible film (support surface layer) is formed by simultaneously performing co-lamination and sequential lamination by using the first dope containing the first polymer and the second dope containing the second polymer different from the first polymer. ), And a laminated flexible film made of a layer (air surface layer) on the surface side of the flexible film, and a layer (base layer) between the support surface layer and the air surface layer. The base layer is composed of the first dopant, and the air surface layer and the supporter surface layer are composed of the second dopant.

When the first polymer and the second polymer are cellulose acylates, the total acyl substitution degree (Z1) of the acyl group in the first polymer is lower than the total acyl substitution degree (Z2) of the acyl group in the second polymer. It is preferable. In particular, the total acyl substitution degree (Z1) of the acyl group in a 1st polymer satisfies Formula (1), and the total acyl substitution degree (Z2) of the acyl group in a 2nd polymer satisfies Formula (2). do.

Equation (1) 2.0 <Z1 <2.7

Formula (2) 2.7 <Z2

From the viewpoint of the wavelength dispersibility of the retardation, the sum (Y1) of the substitution degree (X1) of the acetyl group of the cellulose acylate used for the first polymer and the substitution degree of the acyl group having 3 or more carbon atoms is represented by the following formulas (3) and ( It is preferable to satisfy 4). In addition, X1 and Y1 have a relationship of X1 + Y1 = Z1 between Z1 of the formula (1).

Equation (3) 1.0 <X1 <2.7

Equation (4) 0≤Y1 <1.5

From the viewpoint of the wavelength dispersibility of the retardation, the sum (Y2) of the substitution degree (X2) of the acetyl group of the cellulose acylate used for the second polymer and the substitution degree of the acyl group having 3 or more carbon atoms is represented by the following formulas (5) and ( It is preferable to satisfy 6). In addition, X2 and Y2 have a relationship of X2 + Y2 = Z2 between Z2 of the said Formula (2).

Equation (5) 1.2 <X2 <3.0

Equation (6) 0≤Y2 <1.5

The second dope has a lower viscosity than the first dope. The viscosity of each dope can be calculated | required based on JISK7117.

The second polymer may be cellulose acylate, and the first polymer may be a polymer other than cellulose acylate. It is preferable to use an acrylic resin as a 1st polymer.

(Acrylic resin)

Methacrylic resin is also contained in acrylic resin, The derivative of acrylate / methacrylate, especially the (co) polymer of acrylate ester / methacrylate ester are well known. Although it does not restrict | limit especially as an acrylic resin, What consists of 50-99 mass% of methyl methacrylate units and 1-50 mass% of other monomeric units copolymerizable with this is preferable in order to obtain the film with a small photoelastic coefficient.

In the acrylic resin, other copolymerizable monomers include, for example, alkyl methacrylate having 2 to 18 carbon atoms in alkyl group, alkyl acrylate having 1 to 18 carbon atoms in alkyl number, and alpha, beta -unsaturated compounds such as acrylic acid and methacrylic acid. Aromatic vinyl compounds such as unsaturated group-containing divalent carboxylic acids such as acid, maleic acid, fumaric acid and itaconic acid, styrene, α-methylstyrene, α, β-unsaturated nitrile such as acrylonitrile and methacrylonitrile, maleic anhydride Acid, maleimide, N-substituted maleimide, glutaric anhydride, etc. are mentioned, These can be used individually or as a copolymerization component using 2 or more types of monomers together.

Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, etc. are preferable from the viewpoint of the thermal decomposition resistance and fluidity of a copolymer, And methyl acrylate or n-butyl acrylate are particularly preferably used.

As a resin capable of forming a highly transparent optical film having a small performance change even in a high temperature and high humidity environment, an acrylic resin contains an alicyclic alkyl group as a copolymerization component or forms a cyclic structure in a molecular chain by molecular recyclization. Acrylic resin which has been made is preferable. As an example of the acrylic resin which formed the cyclic structure in the molecular backbone, acrylic thermoplastic resin containing a lactone ring containing polymer is mentioned as one preferable aspect, A preferable resin composition and a synthesis method are described in Unexamined-Japanese-Patent No. 2006-171464. It is. Moreover, resin which contains glutaric anhydride as a copolymerization component as another preferable aspect is mentioned, About a copolymerization component and a specific synthesis method are described in Unexamined-Japanese-Patent No. 2004-070296.

It is preferable that the weight average molecular weights of acrylic resin are 600,000-4 million, it is 800,000-3 million, and it is especially preferable that it is 1 million-1.8 million. The weight average molecular weight of an acrylic resin can be measured by a gel permeation chromatography.

There is no restriction | limiting in particular as a manufacturing method of an acrylic resin, Well-known methods, such as suspension polymerization, emulsion polymerization, block polymerization, or solution polymerization, can be used. In this invention, several acrylic resin can also be used together.

The acrylic resin may also contain other thermoplastic resins. In the present invention, the thermoplastic resin has a glass transition temperature of 100 ° C. or more and a total light transmittance of 85% or more, when mixed with the acrylic resin to form a film, in terms of improving heat resistance and mechanical strength. desirable.

The content rate of the acrylic resin in the said acrylic resin layer and another thermoplastic resin component is the mass ratio of [acrylic resin / (all thermoplastic resin)] * 100, Preferably it is 30-99 mass%, More preferably, 50-97 mass%, More preferably, it is 60-95 mass%. When the content rate of the acrylic resin in the said acrylic resin layer is 30 mass% or more, since heat resistance can fully be exhibited, it is preferable.

As said other thermoplastic resin, For example, olefin polymers, such as polyethylene, a polypropylene, an ethylene propylene copolymer, and a poly (4-methyl-1- pentene); Halogen-containing polymers such as vinyl chloride and chlorinated vinyl resin; Styrene-based polymers such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer; Polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; Polyamides such as nylon 6, nylon 66 and nylon 610; Polyacetal; Polycarbonate; Polyphenylene oxide; Polyphenylene sulfide; Polyether ether ketone; Polysulfones; Polyether sulfone; Polyoxybenzylene; Polyamideimide; Rubber polymers such as ABS resin and ASA resin incorporating polybutadiene rubber and acrylic rubber; And the like. It is preferable that a rubbery polymer has the graft part of the composition compatible with the cyclic polymer in this invention on the surface, and the average particle diameter of a rubbery polymer is 100 nm from a viewpoint of transparency improvement at the time of making a film form. It is preferable that it is the following, and it is more preferable that it is 70 nm or less.

As said other thermoplastic resin, the resin thermodynamically compatible with an acrylic resin is used preferably. As such another thermoplastic resin, the acrylonitrile-styrene copolymer, polyvinyl chloride resin, etc. which have a vinyl cyanide monomer unit and an aromatic vinyl monomer unit are mentioned preferably. Among them, the acrylonitrile-styrene copolymer is preferable because the glass transition temperature is 120 ° C. or higher and the phase difference per 100 μm in the plane direction is 20 nm or less, and an optical film having a total light transmittance of 85% or more can be easily obtained. As an acrylonitrile-styrene type copolymer, the thing of the range of 1: 10-10: 1 is specifically used for the copolymerization ratio in molar unit.

In the case where the first polymer is an acrylic resin, when the simultaneous lamination shared lead or the successive lamination shared lead is performed using the first dope and the second dope, a thickness variation occurs frequently in the laminated flexible film. This thickness variation is due to the destabilization of the interface between the base layer made of the first dope and the layer (support surface layer or air surface layer) formed from the second dope. The destabilization of the interface refers to a phenomenon in which a part of the first dope forming the base layer enters the adjacent support surface layer or the air surface layer. In order to avoid destabilization of this interface, simultaneous lamination sharing or sequential lamination sharing is performed by using a conjoining dope composed of a first dope, a second dope, and a buffer liquid flowing between the first dope and the second dope. It is preferable.

The buffer is lower in viscosity than the first and second dope. Moreover, it is preferable that a buffer consists of liquid compatible with the solvent contained in each dope. It is preferable that they are 1 Pa. Second or more and 15 Pa. Second or less, and, as for the viscosity of a buffer solution, it is more preferable that they are 1 Pa. Second or more and 10 Pa. Second or less. In addition, the viscosity of a buffer can be calculated | required based on JISK7117.

It is preferable that a buffer is the same as the solvent contained in each dope. The buffer may contain a polymer. As a polymer contained in a buffer, a 1st polymer and a 2nd polymer are mentioned, for example, It is preferable that any one of these is contained. It is preferable that the content concentration of the polymer in a buffer is less than 5 mass%.

By using an acrylic resin as a 1st polymer, the optical film which hardly changes an optical characteristic by generation | occurrence | production of a stress and a change of humidity can be manufactured efficiently, suppressing thickness variation.

EXAMPLE

(Experiments 1-8)

Experiments 1 to 8 were performed by the following method. The detail of each experiment is performed in detail about experiment 1, and description of the same part as experiment 1 is abbreviate | omitted about experiment 2-8, and demonstrates a different part.

(Experiment 1)

The prescription of the compound used for preparation of dope 24 is shown below.

100 parts by mass of cellulose triacetate (degree of substitution 2.86)

10 parts by mass of triphenylphosphate (TPP)

0.03 parts by mass of mat (AEROSIL R972)

Solid content which consists of composition ratio of

80 parts by mass of dichloromethane

13.5 parts by mass of methanol

6.5 parts by mass of n-butanol

It added to the mixed solvent which consists of these suitably, stirred and melt | dissolved, and prepared dope 24.

After dope 24 was filtered with filter paper (Toyo Roshi Co., Ltd., # 63LB), it filtered again with a sintered metal filter (Nippon Seisen Co., Ltd. 06N, nominal pore diameter of 10 micrometers), and after filtering with a mesh filter again. Put in stock tank.

[Cellulose triacetate]

In addition, the cellulose triacetate (TAC) used here is 0.1 mass% or less of residual acetic acid, 58 ppm of Ca, 42 ppm of Mg, 0.5 ppm of Fe, 40 ppm of free acetic acid, and 15 ppm of sulfate ions. Was. Moreover, the substitution degree of the acetyl group with respect to hydrogen of the 6th-position hydroxyl group was 0.91. Moreover, 32.5% of all the acetyl groups were the acetyl group which the hydrogen of the 6th-position hydroxyl group substituted. Moreover, the acetone extraction fraction which extracted this TAC with acetone was 8 mass%, and the mass average molecular weight / number average molecular weight ratio was 2.5. Moreover, the yellow index of obtained TAC was 1.7, haze was 0.08, and transparency was 93.5%. This TAC synthesize | combines the cellulose collected from cotton as a raw material.

Using the obtained dope 24, the film 21 (1950 mm in width) was produced in the solution forming equipment 10 shown in FIG. The flexible unit 12 used what was shown in FIG. In the casting unit 12, the dope falling step 131, the casting step 132, the film heating step 133, the skin layer forming step 134, the film drying step 135, and the film cooling step shown in FIG. 8. The flexible film formation process 126 which performs the 136, the peeling process 137, and the support body heating process 138 in order was repeated and performed. The moving speed V of the endless band was 100 m / min. In the peeling process 137 in the nth flexible film formation process 126, the temperature of the band surface 62a in the peeling position PP was T _PP (refer Table 1). Moreover, content of the solvent in the casting film at that time was ZY _PP (refer Table 1). As a result of measuring the temperature of the band surface 62a in the arrival position DP in the (n + 1) th flexible film formation process 126, the temperature of the center part of a Y direction is T _DPc (refer Table 1), and Y The temperature at both ends of the direction was T _DPe (see Table 1). Further, both ends in the Y direction are portions 10 mm inward from both ends in the Y direction of the endless band 62.

Membrane cooling process Support heating process Membrane heating process T _PP ZY _PP T _DPc T _DPe Evaluation results (° C) (mass%) ((℃) ((℃) One 2 3 Experiment 1 U U U 15 130 35 25 A A A Experiment 2 U U U 15 130 35 35 A A B Experiment 3 U radish radish 15 130 7 7 A C B Experiment 4 U U U 5 180 25 25 A A B Experiment 5 U U U 5 180 10 10 A A B Experiment 6 U U U 5 180 8 8 A B B Experiment 7 U radish radish 5 180 0 0 A C B Experiment 8 radish radish radish 20 130 35 35 B - B

(Experiment 2-8)

Presence or absence of the membrane cooling step 136, presence or absence of the membrane heating step 133, presence or absence of the support body heating step 138, temperature T _PP of the band surface 62a at the peeling position _PP , and the peeling position ( The content (ZY _PP ) of the solvent in the flexible film in _PP ), and the temperature (T _DPc , T _DPe ) of the band surface 62a at the arrival position DP are shown in Table 1, In the same manner as in Experiment 1, the film 21 was made of the dope 24.

(evaluation)

In the solution film forming method of Experiment 1-8, it evaluated from the following viewpoints. The number of the evaluation result in Table 1 shows the number added to each evaluation item.

1. Peeling Evaluation

The presence or absence of peeling failure was investigated.

A: A peeling failure did not arise in the peeling process.

B: Peeling failure occurred in the peeling process.

In this evaluation, A passed and B failed.

2. Thickness deviation evaluation

In the following procedure, the presence or absence of the thickness deviation of the film 21 was evaluated. About the film 21, thickness deviation measurement was performed. The procedure of this thickness deviation measurement is as follows. First, approximately 6 cm square sample films were cut from the film 21. Second, the refractive index difference of the sample film was measured using the apparatus which can convert the refractive index difference of a sample film into the thickness difference. As this apparatus, FX-03 FRINGEANALYZER (manufactured by FUJINON Corporation) was used. Third, this refractive index difference was measured over the whole of the sample film, and this average value was made into the thickness variation of the laminated film. Thus, the following reference | standard evaluated the thickness deviation obtained. In addition, the thickness of laminated | multilayer film is the average value of the thickness of six places of the sample film measured with the micrometer.

A: The thickness variation was less than 1.5% with respect to the thickness of the film.

B: Thickness deviation was 1.5% or more and less than 1.8% with respect to the thickness of a film.

C: thickness variation was 1.8% or more with respect to the thickness of the film.

In this evaluation, A and B are a pass and C is a failure.

In addition, in experiment 8, since peeling failure arose in the peeling evaluation mentioned above and the thickness variation of the film was clear, this evaluation was not performed. For this reason, it describes with "-" in the "2" column of the evaluation result of the experiment 8 in Table 1.

3. Foam evaluation

The obtained flexible film was visually observed and the presence or absence of foaming was examined.

A: Foaming in the edge portion could not be confirmed.

B: Although foaming was confirmed in the edge part, since it was limited to the part cut out by the slitter 36, there was no problem as a film for products.

C: Foaming was confirmed to the part used as the film for products.

In this evaluation, A and B are a pass and C is a failure.

Claims (16)

In the method of forming a flexible membrane to form a flexible membrane on the movable support, the movable support moves in such a manner that the movable support moves repeatedly through the arrival position where the falling dope reaches and the peeling position where the flexible membrane is peeled off.
(A) flowing the dope into the moving support;
(B) evaporating the solvent from the flexible membrane formed on the surface of the moving support;
(C) cooling said flexible membrane until it becomes independent and can be conveyed;
(D) peeling off said flexible film after said C from said moving support;
(E) heating the moving support after step C before the next step B; And,
(F) using the heat imparted to the moving support in step E to heat the flexible membrane before the next step B; and
The dope comprises a polymer and a solvent,
The flexible membrane is made of a dope falling in the step A,
The cooling is performed after the step B,
Method of Forming Flexible Film. The method according to claim 1,
In the step E, the flexible film forming method of heating the moving support before the next step A. The method according to claim 1,
In the step E, the flexible film forming method of heating the moving support after the next step A. The method according to claim 1,
In the step E, the movable support is heated so that the flexible region, which is set on the surface of the movable support and forms the flexible film from the dropped dope, is hotter than the non-flexible region except the flexible region of the surface of the movable support. Method of forming flexible film The method according to claim 1,
The temperature of the said moving support in step D is 5 degreeC or more and 15 degrees C or less, and the said F step is performed until the temperature of the said moving support becomes 8 degreeC or more and the boiling point of the said solvent. The method according to claim 1,
A method of forming a flexible film, which is performed between the step F and the subsequent step B, wherein a skin layer forming wind is blown onto the surface of the flexible film to form a skin layer on the surface side of the flexible film. A solution film forming method for producing a film by peeling and drying a flexible film formed on a moving support from the moving support, wherein the moving support moves so as to repeatedly pass through an arrival position at which a falling dope reaches and a peeling position at which the flexible film is peeled off. In the solution film forming method,
(A) flowing the dope into the moving support;
(B) evaporating the solvent from the flexible membrane formed on the surface of the moving support;
(C) cooling said flexible membrane until it becomes independent and can be conveyed;
(D) peeling off said flexible film after said C from said moving support;
(E) heating the moving support after step C before the next step B;
(F) heating the flexible membrane before the next step B using the heat applied to the moving support in step E; And,
(G) evaporating the solvent from the cast film peeled from the moving support to dry the cast film and to obtain a film.
The dope comprises a polymer and a solvent,
The flexible membrane is made of a dope falling in the step A,
The cooling is performed after the step B,
Solution film formation method. In the forming apparatus of the flexible film,
A moving support that circulates through the reaching portion, the flexible portion, the membrane drying portion, and the peeling portion in order; An reaching part support unit for supporting the movable support located at the reaching part;
A peeling part supporting unit which supports the moving support located in the peeling part;
A membrane cooling unit that cools the flexible membrane until the movable support moves out of the membrane drying portion to reach the peeling portion and becomes self-supporting and transportable;
A support heating unit that heats the moving support from the peeling part until it reaches the film drying part; And,
And a film heating unit for heating the flexible film before reaching the film drying unit by using heat provided by the support heating means,
The reaching portion reaches the falling dope, the dope comprises a polymer and a solvent, the casting portion forms the casting film with the falling dope, the film drying portion evaporates the solvent from the casting film, and the peeling portion An apparatus for forming a flexible film in which the flexible film is peeled off. The method according to claim 8,
The support body heating unit is a flexible film forming apparatus which heats the movable support until it reaches the reaching part beyond the peeling part. The method according to claim 8,
The said support body heating unit forms the flexible film | membrane which heats the said moving support body from the said reaching part until it reaches the said film drying part. The method according to claim 8,
The support heating unit is configured to form a flexible film for heating the movable support such that the flexible region for forming the flexible film set on the surface of the movable support becomes higher than the non-flexible region except the flexible region of the surface of the movable support. Device. The method according to claim 8,
A skin layer forming unit is provided on the surface of the flexible film to form a skin layer on the surface side of the flexible film, and the skin layer forming unit is provided between the support heating unit and the film drying unit. Apparatus for forming a flexible film. The method according to claim 8,
The reaching part supporting unit includes an reaching part supporting roller, the peeling part supporting unit includes a peeling part supporting roller, and the moving support is an endless band spanning the reaching part supporting roller and the peeling part supporting roller. Forming device. The method according to claim 8,
The said support body heating unit is a flexible film | membrane formation apparatus provided with the heating wind duct which blows a heating wind with the said moving support body. The method according to claim 8,
The film cooling unit is a flexible film forming apparatus for cooling the peeling unit support unit. The method according to claim 15,
The said membrane cooling unit adjusts the temperature of the said moving support body in the said peeling part to 5 degreeC or more and 15 degrees C or less, The said support body heating unit has the temperature of the said moving support body in the said flexible part 8 degreeC or more said solvent The casting film formation apparatus which heats the said moving support body so that it may become below the boiling point of.

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