JP2006116937A - Tentering machine of solution film forming equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the lowering of the shaking operation capacity of flapper in the tentering machine of solution film forming equipment. <P>SOLUTION: A clip 10 is equipped with a frame 31 and the flapper 32, and a bearing 37 is penetrated in the attaching hole 32d of the flapper 32 to be attached to the flapper 32. When an attaching shaft 35 is inserted in one attaching shaft insertion hole 34a, two dry bearings 37 and another attaching shaft insertion hole 34a, the flapper 32 is attached to the frame 31 in a freely revolvable manner. When the flapper 32 is revolved, the attaching shaft 35 and the dry bearings 37 are allowed to slide. Each of the dry bearings 37 is constituted of Diedine DDK01 (R) (brand name) and first and second wind barrier covers are provided so as to cover the clip 10. A fresh air supply pipe is connected to the first and second wind barrier covers and blowoff ports are provided to the first and second wind barrier covers. The fresh air passed through the fresh air supply pipe is blown off from the blowoff ports to the flapper 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tenter apparatus for solution casting equipment.

  The tenter device transports and dries a film that is gripped on both side edges by an openable and closable clip, and manufactures a polymer film free from uneven thickness and optical characteristics. The clip is configured such that a flapper is swingably attached to an upper portion of a U-shaped clip body via an attachment shaft. The flapper is normally in a closed position by its own weight, and in this closed position, the film is gripped between the lower part of the clipper body and the lower end of the flapper. Further, when the film side edge is gripped, the flapper is rotated obliquely upward by engaging the upper end of the flapper with the clip opener, thereby bringing the flapper to the open position. The clip grips the film at the entrance of the tenter device and opens the grip at the exit. If the clip does not grip the film well, thickness unevenness and optical property unevenness occur, and film breakage occurs. In addition, the film quality is poor. Therefore, various devices have been considered for gripping the clip (see, for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 11-77719 (FIG. 4) JP-A-11-90943 (FIG. 11)

  By the way, when a cellulose acylate film is produced by the solution casting apparatus having the tenter device, an optically excellent variety with high lettering can be stably produced at the initial stage of production, but a certain period of time passes. There is a problem that the optical characteristics vary, and a solution has been desired.

  The present invention has been made to solve the above-described problems, and provides a tenter device for a solution film-forming facility capable of preventing the opening / closing operation performance of the clip from being lowered and extending the operating life of the clip. For the purpose.

  As a result of intensive investigations to achieve the above object, it has been found that defective products are generated due to poor opening and closing of the clips of the tenter device. That is, since TPP (triphenylfostate) contained as a plasticizer volatilizes from the film when the film is dried, if the volatilized TPP adheres to the dry bearing and causes condensation, the dry bearing and the mounting shaft slide. The shavings generated by the movement and the condensed TPP will be a crystallized lump. Due to this lump, the sliding performance of the dry bearing is lowered, and the clip cannot be closed by its own weight, and may be in an open state. When the clip is in an open state, the film cannot be gripped in part, and unevenness in thickness and optical characteristics occur after drying in the ungripped part, resulting in poor film quality. I understood.

  In order to eliminate this grip failure, it is conceivable that the film is gripped by a clip using the bias of a spring. However, when a film is manufactured by solution casting, the rigidity of the film is small, so When a film is gripped by a clip using urging, there is a problem that the gripped film is torn.

  In order to achieve the above object, the tenter apparatus of the solution casting apparatus of the present invention is the tenter apparatus of the solution casting apparatus in which the both side edges of the film are gripped and conveyed by a clip, and the film is dried. Between the clip body having a film mounting portion on which the side edge portion of the film is placed and the film mounting portion for gripping the side edge portion of the film, and the retracted position retracted from the gripping position. The clip is composed of a movable gripping lever, a mounting shaft that swingably mounts the gripping lever to the clip body, and a dry bearing that supports the mounting shaft. The dry bearing has self-lubricating properties. It is characterized in that a material that has little dust generation due to wear is used.

  In addition, it is preferable that the said dry bearing is comprised from the tetrafluoroethylene resin and solid lubricant which do not contain lead. Further, a clip cover that is provided in a travel area of the clip at the gripping position and covers the clip, and blows air into the clip cover to prevent the intrusion of dry air in the tenter to the clip at the gripping position. It is preferable to have a blowing means. Furthermore, the film is preferably a cellulose acylate film.

  According to the tenter device of the solution casting apparatus of the present invention, a clip that holds both side edges of the film when the film is transported and dried, a clip body having a film mounting portion on which the side edges of the film are placed, The grip lever that can swing between the gripping position for gripping the side edge of the film with the film mounting portion and the retracted position that is retracted from the gripping position, and the grip lever can swing freely on the clip body It consists of a mounting shaft to be mounted and a dry bearing that supports this mounting shaft. The dry bearing uses self-lubricating materials that are less likely to generate dust due to wear. There is no longer to do.

  Also, since the dry bearing is composed of a tetrafluoroethylene resin that does not contain lead and a solid lubricant, it does not deteriorate due to the volatile components of the film, so the swinging performance of the grip lever may be reduced. Disappear.

  Further, a clip cover that is provided in the traveling region of the clip at the gripping position and covers the clip, and a blower unit that blows air into the clip cover and prevents the intrusion of the dry air in the tenter to the clip at the gripping position. Therefore, the generation of foreign matter due to the volatile components in the dry air and the shavings of the lubricant of the dry bearing is suppressed, and the swinging operation performance of the grip lever is not deteriorated.

  FIG. 1 is a schematic plan view showing a tenter device 2 embodying the present invention. The tenter device 2 transports the wet film (film) 3 formed by peeling from the casting band 113 (see FIG. 9) in the film transport direction A and extends in the film width direction B. A first rail 5, a second rail 6, and first and second chains (endless chains) 7 and 8 guided by the rails 5 and 6 are provided. The tenter device 2 is divided into areas of a first drying unit 2a, a second drying unit 2b, and a third drying unit 2c in order from the tenter inlet 16 side. In each of the drying units 2a to 2c, drying air for drying the wet film 3 is blown out toward the wet film 3 by a blower (not shown). Thereby, the wet film 3 conveyed by each drying part 2a-2c is dried.

  A number of clips 10 are attached to the first and second chains 7 and 8 at a predetermined pitch. The clip 10 extends along the film width direction B by moving along the rails 5 and 6 while gripping the side edge of the wet film 3. In this embodiment, when the width of the wet film 3 before stretching is 100%, the stretched film is stretched so that the width after stretching is 103%. However, the stretching ratio is appropriately changed without being limited thereto. It is what is done.

  The first and second chains 7 and 8 are spanned between the driving sprockets 11 and 12 and the driven sprockets 13 and 14. The first chain 7 is connected by the first rail 5 between the sprockets 11 to 14. The second chain 8 is guided by the second rail 6. The driving sprockets 11 and 12 are provided on the tenter outlet 17 side, these are rotationally driven by a driving mechanism (not shown), and the driven sprockets 13 and 14 are provided on the tenter inlet 16 side. Further, the tenter inlet 16 is provided with an inlet opening member 21 that displaces the clip 10 to the open position, and the inlet opening member 22 is attached to the second rail 6, respectively. At the tenter outlet 17, an outlet opening member 23 for displacing the clip 10 to the open position is attached to the first rail 5, and an outlet opening member 24 is attached to the second rail 6.

  As shown in FIGS. 2 and 3, the clip 10 includes a substantially U-shaped frame (clip body) 31, a flapper (grip lever) 32, and a rail attachment portion 33. The frame 31 is formed with two flapper attachment portions 34 for attaching a flapper 32. The flapper attachment portion 34 has an attachment shaft insertion hole 34a for inserting an attachment shaft 35, and the attachment shaft insertion portion. A pin press-fitting hole 34b for press-fitting a fixing pin 36 that fixes the mounting shaft 35 inserted through the hole 34a in a non-detachable state is formed. Two pin press-fit holes 34b are formed on the top and bottom. The mounting shaft 35 is formed with two pin press-fit holes 35a for press-fitting the fixing pins 36 on the left and right. Two fixing pins 36 are provided.

  The flapper 32 grips the wet film 3 between the contact head 32 a that contacts the inlet opening members 21 and 22 and the outlet opening members 23 and 24, and the film gripping surface (film mounting portion) 31 a of the frame 31. A portion 32b and a rotation shaft portion 32c are provided, and an attachment hole 32d for attaching the dry bearing 37 is formed in the rotation shaft portion 32c. As the dry bearing 37, for example, Dydyne DDK01 (trade name) manufactured by Daido Metal Industry Co., Ltd. is used, and two are press-fitted into the mounting hole 32d. For this reason, it is preferable that the dry bearing 37 is made of a press-fit material (for example, resin).

  As an assembly method of the clip 10, two dry bearings 37 are respectively press-fitted and attached to the attachment holes 32 d of the flapper 32. The mounting shaft 35 is inserted into one mounting shaft insertion hole 34a, the two dry bearings 37, and the other mounting shaft insertion hole 34a, and the two fixing pins 36 are press-fitted into the pin press-fit holes 34b and 35a, respectively. . As a result, the mounting shaft 35 is positioned so as not to rotate and is attached to the flapper mounting portion 34, and the flapper 32 is rotatably attached to the frame 31. When the flapper 32 rotates, the mounting shaft 35 and the dry bearing 37 slide.

  As shown in FIGS. 4 and 5, the first chain 7 or the second chain 8 is attached to the rail attachment portion 33. FIG. 4 shows a state immediately before the start of gripping, and FIG. 5 shows a state immediately after the gripping. The flapper 32 has a film gripping position (grip position) in a vertical state, and an opening position in which the contact head 32a contacts the inlet opening members 21 and 22 and the outlet opening members 23 and 24 and rotates obliquely ( Normally, the film is urged to reach the film gripping position by its own weight. At the film gripping position PA, the wet film 3 is gripped by the film gripping surface 31a and the gripping portion 32b.

  The rail attachment portion 33 includes an attachment frame 41 and guide rollers 42, 43, and 44. The first chain 7 or the second chain 8 is attached to the attachment frame 41. The guide rollers 42 to 44 come into contact with the support surfaces of the driven sprockets 13 and 14 as shown in FIG. 4, or the guide rollers 42 to 44 come into contact with the support surfaces of the first rail 5 or the second rail 6 as shown in FIG. And rotate. Thereby, the clip 10 is guided along the rails 5 and 6 without dropping off from the sprockets 13 and 14 and the rails 5 and 6.

  The inlet opening members 21 and 22 are brought into contact with the contact head 32a of the flapper 32 of the clip 10 in front of the film gripping position PA to rotate the flapper 32 from the closed position to the opened position, thereby bringing the clip 10 into the opened state. , Allowing the side edges of the wet film 3 to be received. Then, when passing through the film gripping position PA, the contact head 32a is separated from the inlet opening members 21 and 22, the flapper 32 is rotated from the open position to the closed position, and the side edge of the wet film 3 is gripped. The Similarly, the outlet opening members 23 and 24 rotate the flapper 32 from the closed position to the open position at the film holding release position PB to release the clip 10 to hold the side edge of the wet film 3. Open. The wet film 3 released by the clip 10 at the film holding release position PB is discharged from the tenter outlet 17. The wet film 3 discharged from the tenter outlet 17 is sent out to the ear clip device 142 as a film 141 (see FIG. 9). In addition, as for each open member 21-24, in order to restrain contact resistance with the contact head 32a of the flapper 32 small, the thing made from resin is used preferably. Nylon, delrin or the like is used as the resin.

  As shown in FIGS. 6 and 7, first and second clip covers (clip covers) 51 and 52 that cover the clip 10 are provided above the first and second rails 5 and 6, respectively. . The first and second clip covers 51 and 52 are provided over the entire area between the film gripping position PA and the film gripping release position PB of the tenter device 2. Since the first clip cover 51 and the second clip cover 52 are configured by members having the same structure, only the first clip cover 51 will be described as an example, and the description of the second clip cover 52 will be simplified. As shown in FIG. 6, the first clip cover 51 is provided so as to cover the frame 31 and the flapper 32 of the clip 10 moving along the first rail 5, and the drying air for drying the wet film 3 is provided. Is filled with fresh air so as to prevent it from hitting the clip 10, and the pressure is higher than in the tenter device 2. The first clip cover 51 is connected to a fresh air supply pipe 55 that sends fresh air toward the clip 10, mainly the flapper 32. The first clip cover 51 is provided with a blowout port 56. The outlet 56 blows out fresh air sent from the fresh air supply pipe 55 toward the flapper 32. The blowout port 56 is provided over the entire region of the first clip cover 51 in the film conveyance direction A.

  An exhaust cover 57 is connected to the first and second clip covers 51 and 52. The dry air in the first and second clip covers 51 and 52 is cooled by a cooler (not shown) by the exhaust cover 57 and then sent to the dry air circulation unit 60 for heat exchange (not shown). The temperature is brought to a predetermined temperature range by the vessel and returned to the drying units 2a to 2c.

  The fresh air supply pipe 55 sends the fresh air whose air volume is controlled by adjusting the air volume adjustment valve 62 to the first clip cover 51. The fresh air supply pipe 55 is connected to a position corresponding to each drying unit 2 a to 2 c of the first clip cover 51 and a position corresponding to each drying unit 2 a to 2 c of the second clip cover 52.

  As shown in FIG. 7, the fresh air supply pipe 55 is connected to a TPP removal unit 65. The TPP removal unit 65 is connected to each of the drying units 2a to 2c, and the dry air in each of the drying units 2a to 2c is sent to the TPP removal unit 65. In each drying part 2a-2c, since TPP (triphenylfostate) contained as a plasticizer from the wet film 3 is volatilized, TPP is contained in the internal dry air. The TPP removal unit 65 removes the TPP in the dry air that has been sent. The dry air from which TPP has been removed is sent to the fresh air supply pipe 55. On the way, fresh air is taken in from the outside by opening a valve (not shown), and the fresh air and the air sent from the TPP removal unit 65 merge to each of the drying units 2a to 2c. It is sent to the fresh air supply pipe 55 provided. At that time, the amount of air sent to the fresh air supply pipe 55 is adjusted by the air volume adjusting valve 62. In the present embodiment, the air blowing means for blowing air into the first and second clip covers 51 and 52 includes a fresh air supply pipe 55 and a blowout port 56.

  Next, a method for producing the wet film 3 will be described. However, the manufacturing method and manufacturing apparatus described below are examples of the present invention, and the present invention is not limited thereto.

[material]
In the present embodiment, cellulose acylate is used as the polymer, and triacetyl cellulose (TAC) is particularly preferable as the cellulose acylate. The TAC may be obtained from either linter cotton or pulp cotton, but is preferably obtained from linter cotton. Among cellulose acylates, those in which the substitution degree of the acyl group substituted with the hydroxyl group of cellulose satisfies all of the following formulas (I) to (III) are more preferable. In the following formulas (I) to (III), A and B represent the substitution degree of the acyl group substituted with the hydroxyl group of cellulose, A is the substitution degree of the acetyl group, and B is 3 carbon atoms. The substitution degree of the acyl group of ˜22. In addition, it is preferable that 90 mass% or more of TAC is a particle | grain of 0.1 mm-4 mm.
(I) 2.5 ≦ A + B ≦ 3.0
(II) 0 ≦ A ≦ 3.0
(III) 0 ≦ B ≦ 2.9

  Moreover, as a solvent for preparing the dope, aromatic hydrocarbons (for example, benzene, toluene, etc.), halogenated hydrocarbons (for example, dichloromethane, chlorobenzene, etc.), alcohols (for example, methanol, ethanol, n-propanol, Examples thereof include n-butanol, diethylene glycol, etc., ketones (eg, acetone, methyl ethyl ketone, etc.), esters (eg, methyl acetate, ethyl acetate, propyl acetate, etc.) and ethers (eg, tetrahydrofuran, methyl cellosolve, etc.). Here, the dope is a polymer solution or dispersion obtained by dissolving or dispersing a polymer in a solvent.

  Among these, halogenated hydrocarbons having 1 to 7 carbon atoms are preferably used, and dichloromethane is most preferably used. And from the viewpoint of properties such as the solubility of TAC, the peelability of the cast film from the support, the mechanical strength of the film, and the optical properties of the film, one or several kinds of alcohols having 1 to 5 carbon atoms are selected. It is preferable to use it mixed with dichloromethane. At this time, the content of the alcohol is preferably 2% by mass to 25% by mass and more preferably 5% by mass to 20% by mass with respect to the entire solvent. Specific examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, etc. Among them, methanol, ethanol, n-butanol, or a mixture thereof is more preferably used.

  By the way, recently, for the purpose of minimizing the influence on the environment, studies have been conducted on the solvent composition when dichloromethane is not used. For this purpose, ethers having 4 to 12 carbon atoms, carbon atoms A ketone having 3 to 12 carbon atoms and an ester having 3 to 12 carbon atoms are preferable, and these may be used by appropriately mixing them. These ethers, ketones and esters may have a cyclic structure. A compound having two or more functional groups of ether, ketone and ester (that is, —O—, —CO— and —COO—) can also be used as a solvent. The solvent may have another functional group such as an alcoholic hydroxyl group in the chemical structure.

  The details of cellulose acylate are described in paragraphs [0140] to [0195] of Japanese Patent Application No. 2004-264464. These descriptions are also applicable to the present invention. The same applies to additives such as solvents and plasticizers, deterioration inhibitors, UV absorbers (UV agents), optical anisotropy control agents, retardation control agents, dyes, matting agents, release agents, release accelerators, etc. The details are described in paragraphs [0196] to [0516] of Japanese Patent Application No. 2004-264464.

[Dope production method]
First, a dope is manufactured using the above raw materials. FIG. 8 shows a dope manufacturing facility 70. The dope manufacturing facility 70 has a solvent tank 71 for storing the solvent, a dissolution tank 73 for mixing the solvent and TAC, etc., a hopper 74 for supplying TAC, and an additive for storing the additive. An additive tank 75, a heating device 86 for heating the swelling liquid described later, a temperature controller 87 for adjusting the temperature of the heated swelling liquid, filtration devices 88 and 95, A flash device 91 for adjusting the dope concentration is provided. The dope manufacturing facility 70 is further provided with a recovery device 92 for recovering the solvent and a regeneration device 93 for regenerating the recovered solvent. The dope manufacturing equipment 70 is connected to the stock tank 90 of the solution casting equipment 100.

  In the present embodiment, the dope is manufactured by the following method using the above-described dope manufacturing facility 70. First, the valve 72 is opened, and the solvent is sent from the solvent tank 71 to the dissolution tank 73. Next, the TAC contained in the hopper 74 is fed into the dissolution tank 73 while being measured. Further, the required amount of the additive solution is sent from the additive tank 75 to the dissolution tank 73 by opening and closing the valve 76.

  In addition to the method of sending the additive as a solution, for example, when the additive is liquid at room temperature, it can be sent to the dissolution tank 73 in the liquid state. In addition, when the additive is solid, a method of feeding into the dissolution tank 73 using a hopper or the like is also possible. When a plurality of types of additives are added, a solution in which a plurality of types of additives are dissolved can be placed in the additive tank 75. Alternatively, a solution in which an additive is dissolved can be put in each of a plurality of additive tanks and can be sent to the dissolution tank 73 through independent pipes.

  In the above description, the order of putting into the dissolution tank 73 is the solvent (used in the meaning including the case of the mixed solvent), TAC, and additive, but it is not limited to this order. For example, a preferred amount of solvent can be fed after the TAC is metered into the dissolution tank 73. Further, it is not always necessary to add the additive to the dissolution tank 73 in advance, and it can be mixed with a mixture of TAC and a solvent (hereinafter, these mixtures may also be referred to as a dope) in a later step.

  As shown in FIG. 8, the dissolution tank 73 is provided with a jacket 77 that encloses the outer surface thereof, and a first stirrer 79 that is rotated by a motor 78. Furthermore, it is preferable that a second stirrer 81 that is rotated by a motor 80 is attached to the dissolution tank 73. The first stirrer 79 is preferably provided with an anchor blade, and the second stirrer 81 is preferably a dissolver type eccentric stirrer. And the melting tank 73 used by this embodiment is temperature-adjusted by flowing a heat-transfer medium inside the jacket 77, The preferable temperature range is the range of -10 degreeC-55 degreeC. By appropriately selecting and using the types of the first stirrer 79 and the second stirrer 81, a swelling liquid 82 in which TAC is swollen in a solvent is obtained.

  Next, the swelling liquid 82 is sent to the heating device 86 by the pump 85. The heating device 86 is preferably a jacketed pipe, and further preferably has a configuration capable of pressurizing the swelling liquid 82. By using such a heating device 86, the solid content in the swelling liquid 82 is dissolved under heating conditions or pressure heating conditions. In addition, it is preferable that the temperature in swelling and melt | dissolution is 50 to 120 degreeC. Moreover, the well-known cooling dissolution method which cools the swelling liquid 82 to the temperature of -100 degreeC--30 degreeC without using the heating apparatus 86 can also be performed. TAC can be sufficiently dissolved in a solvent by appropriately selecting the heating dissolution method and the cooling dissolution method. After the dope is brought to about room temperature by the temperature controller 87, the dope is filtered by the filtration device 88 to remove impurities contained in the dope. The filtration filter used in the filtration device 88 preferably has an average pore diameter of 100 μm or less. The filtration flow rate is 50 liters / hr. The above is preferable. The dope after filtration is sent to the stock tank 90 in the solution casting apparatus 100 via the valve 89 and stored therein.

  By the way, as mentioned above, once the swelling liquid 82 is prepared and then the swelling liquid 82 is used as a solution, the time required increases as the concentration of TAC is increased, which is a problem in terms of manufacturing cost. There is. In that case, it is preferable to prepare a dope having a concentration lower than the target concentration and then perform a concentration step for obtaining the target concentration. When such a method is used, the dope 96 filtered by the filtering device 88 is sent to the flash device 91 via the valve 89, and a part of the solvent in the dope is evaporated in the flash device 91. The solvent gas generated by the evaporation is condensed by a condenser (not shown) to become a liquid and is recovered by the recovery device 92. The recovered solvent is regenerated and reused as a solvent for dope preparation by the regenerator 93. This reuse is effective in terms of cost.

  Further, the concentrated dope 96 is extracted from the flash device 91 by the pump 94. Furthermore, it is preferable that a bubble removal process for removing bubbles generated in the dope 96 is performed. As this defoaming method, various known methods are applied, for example, an ultrasonic irradiation method. The dope 96 is then sent to the filter device 95 to remove foreign matter. In addition, it is preferable that the temperature of dope 96 in the case of filtration is 0 degreeC-200 degreeC. Then, the dope 96 is sent to the stock tank 90 and stored. The dope in the stock tank 90 is sent to the solution casting apparatus 100.

  It is preferable to mix the raw material dope and an additive liquid (for example, an ultraviolet absorber liquid) added to the raw material dope using an in-line mixer (for example, a static mixer) that mixes during the transfer. It is more preferable to perform mixing by connecting a plurality of in-line mixers having different mixing methods in series.

  As the in-line mixer, it is preferable to include at least one of a static mixer and a through the mixer. When the static mixer is provided, the number of elements of the static mixer is preferably 6 or more and 9 or less, and more preferably 6 or more and 60 or less.

  In the case where both a static mixer and a slew mixer are provided, the slew mixer is preferably arranged on the upstream side of the static mixer. Further, the distance between the through-the-mixer and the addition port for adding the additive liquid is preferably 5 mm or more and 150 mm or less, and further, the distance between the through-the-mixer and the addition port for adding the additive liquid is 5 mm or more and 15 mm or less. Is more preferable. Moreover, it is preferable that the upstream edge part of the element which comprises a through-zer mixer is located in the inner wall vicinity of the piping through which the said raw material dope flows.

  Furthermore, it is preferable that a first filtration device for filtering the raw material dope is provided on the upstream side of the in-line mixer, and an additive is added to the raw material dope after filtration by the first filtering device, and further, the downstream side of the in-line mixer It is more preferable that a second filtering device for filtering the dope is provided, and the dope mixed by the in-line mixer is filtered by the second filtering device.

In the present embodiment, it is preferable that the following is satisfied.
(1) When the flow rate of the additive solution is V1 and the flow rate of the raw material dope is V2, 1 ≦ V1 / V2 ≦ 5.
(2) The additive ratio of the additive liquid is 0.1% to 50% in flow rate ratio.
(3) When the viscosity of the additive solution is N1 and the viscosity of the raw material dope is N2, 1000 ≦ N2 / N1 ≦ 100000 is satisfied, and at 20 ° C., 5000 cP ≦ N1 ≦ 500000 cP, and 0 .1 cP ≦ N2 ≦ 100 cP.
(4) The shear rate of the raw material dope is 0.1 (1 / s) to 30 (1 / s).
(5) The polymer is cellulose acylate.
(6) The additive solution is a solution containing the main solvent of the polymer solution.
(7) The additive solution is a solution containing the main solvent of the polymer solution and has a composition different from that of the raw material dope.
(8) The additive solution is a solution containing the main solvent of the polymer solution, and contains at least one ultraviolet absorber.
(9) The additive solution is a solution containing the main solvent of the polymer solution, and is formed by dispersing at least one kind of inorganic or organic fine particles.
(10) The additive solution is a solution containing the main solvent of the polymer solution and contains at least one type of peeling accelerator.
(11) The additive solution is a solution containing the main solvent of the polymer solution and contains at least one kind of poor solvent.

  By the above method, the dope whose TAC density | concentration is 5 mass%-40 mass% can be manufactured. More preferably, the TAC concentration is from 15% by mass to 30% by mass, and most preferably from 17% by mass to 25% by mass. The concentration of the additive (mainly a plasticizer) is preferably in the range of 1% by mass or more and 20% by mass or less when the total solid content in the dope is 100% by mass. In addition, from the [0517] paragraph of Japanese Patent Application No. 2004-264464 about the raw material in the solution casting method which obtains a TAC film, the raw material, the additive dissolution method and addition method, the filtration method, and the dope production methods such as defoaming [0616] The paragraph is detailed. These descriptions are also applicable to the present invention.

[Solution casting method]
Next, a method for producing a film using the dope 96 obtained above will be described. FIG. 9 is a schematic view showing the solution casting apparatus 100. However, the present invention is not limited to the solution casting apparatus as shown in FIG. The solution casting apparatus 100 includes a stock tank 90, a filtration device 104, a casting die 110, a casting band 113 stretched around rotating rollers 111 and 112, and a tenter device 2. Further, an ear clip device 142, a drying chamber 145, a cooling chamber 147, and a winding chamber 150 are arranged.

  A stirrer 102 that is rotated by a motor 101 is attached to the stock tank 90. The stock tank 90 is connected to the casting die 110 via the pump 103 and the filtration device 104.

The material of the casting die 110 is preferably two-layer stainless steel or precipitation hardening stainless steel, and preferably has a thermal expansion coefficient of 2 × 10 ⁻⁵ (° C. ⁻¹ ) or less. And what has corrosion resistance substantially equivalent to SUS316 in the forced corrosion test with electrolyte aqueous solution can be used as the material of the casting die 110, and further immersed in a mixed solution of dichloromethane, methanol and water for 3 months. Even if it has corrosion resistance, no pitting (perforation) occurs at the gas-liquid interface. Furthermore, it is preferable to manufacture the casting die 110 by grinding a material that has passed one month or more after casting. As a result, the dope 96 flows uniformly in the casting die 110, and streaks and the like are prevented from occurring in the casting film described later. The finishing accuracy of the liquid contact surface between the casting die 110 and the feed block described later is preferably 1 μm or less in terms of surface roughness and the straightness is 1 μm / m or less in any direction. The slit clearance of the casting die 110 can be adjusted within a range of 0.5 mm to 3.5 mm by automatic adjustment. About the corner | angular part of the liquid-contacting part of the lip | tip end of the casting die 110, the R is 50 micrometers or less over the whole width. Moreover, it is preferable that the shear rate inside the casting die 110 is adjusted to be 1 (1 / sec) to 5000 (1 / sec).

  The width of the casting die 110 is not particularly limited, but is preferably about 1.0 to 2.0 times the width of the film to be the final product. Further, it is preferable to attach a temperature controller to the casting die 110 so that the temperature during film formation is maintained at a predetermined temperature. The casting die 110 is preferably a coat hanger type. Further, it is more preferable that thickness adjusting bolts (heat bolts) are provided at predetermined intervals in the width direction of the casting die 110 and the casting die 110 is provided with an automatic thickness adjusting mechanism using a heat bolt. The heat bolt is preferably formed by setting a profile according to the amount of pump 103 (preferably a high precision gear pump) according to a preset program. Further, feedback control may be performed by an adjustment program based on a profile of a thickness meter (for example, an infrared thickness meter) (not shown) in the solution casting apparatus 100. The thickness difference between any two points in the width direction of the product film, excluding the casting edge portion, is adjusted within 1 μm, and the difference between the minimum value and the maximum value in the width direction thickness is adjusted to 3 μm or less. Preferably, adjusting to 2 μm or less is more preferable. In addition, it is preferable to use a lip gap whose accuracy is adjusted to ± 50 μm or less.

More preferably, a cured film is formed on the lip end of the casting die 110. A method for forming the cured film is not particularly limited, and examples thereof include ceramic coating, hard chrome plating, and a nitriding method. When ceramics are used as the cured film, those that can be ground, have low porosity, are not brittle, have good corrosion resistance, have good adhesion to the casting die 110, and do not have adhesion to the dope 96 are preferable. Specifically, tungsten carbide (WC), Al ₂ O ₃ , TiN, Cr ₂ O _{3 and the} like can be mentioned, among which WC is particularly preferable. The WC coating can be performed by a thermal spraying method.

  In order to prevent the dope 96 flowing out to the slit end of the casting die 110 from locally drying and solidifying, it is preferable to attach a solvent supply device (not shown) to the slit end. In this case, a solvent for solubilizing the dope 96 (for example, a mixed solvent of 86.5 parts by mass of dichloromethane, 13 parts by mass of acetone, and 0.5 parts by mass of n-butanol) is used at both ends of the casting bead and at the end of the die slit. It is preferable to supply near the periphery of the three-phase contact line formed by the part and outside air. In addition, as a pump which supplies this liquid, it is preferable to use a pump with a pulsation rate of 5% or less.

  Below the casting die 110, there is provided a casting band 113 that spans the rotating rollers 111 and 112. The rotating rollers 111 and 112 are rotated by a driving device (not shown), and the casting band 113 travels endlessly with the rotation. It is preferable that the casting band 113 can move at a moving speed, that is, a casting speed of 10 m / min to 200 m / min. Further, in order to set the surface temperature of the casting band 113 to a predetermined value, it is preferable that a heat transfer medium circulation device 114 is attached to the rotary rollers 111 and 112, and the casting band 113 has a surface temperature of It is preferable that the temperature can be adjusted to -20 ° C to 40 ° C. A heat transfer medium flow path (not shown) is formed in the rotating rollers 111 and 112 used in the present embodiment, and the heat transfer medium maintained at a predetermined temperature passes through the flow path. Thus, the temperature of the rotating rollers 111 and 112 is maintained at a predetermined value.

It is also possible to use the rotating rollers 111 and 112 directly as a support. In this case, it is preferable that the rotation can be performed with high accuracy so that the rotation speed variation is 0.2% or less. In this case, it is preferable that the average roughness of the surfaces of the rotating rollers 111 and 112 is 0.01 μm or less. It is preferable to perform a hard chrome plating process or the like on the surfaces of the rotating rollers 111 and 112, thereby further providing sufficient hardness and durability. It should be noted that surface defects of the support (the casting band 113 and the rotating rollers 111 and 112) are preferably suppressed to a minimum. Specifically, there is no pinhole of 30 μm or more, and the number of pinholes of 10 μm or more and less than 30 μm is 1 / m ² or less, and the number of pinholes of less than 10 μm is preferably ² / m ² or less.

  Casting equipment such as the casting die 110 and the casting band 113 is accommodated in the casting chamber 115. The casting chamber 115 is provided with a temperature control facility 116 for keeping the internal temperature at a predetermined value, and a first condenser (condenser) 117 for condensing and recovering the volatile organic solvent. Yes. A recovery device 118 for recovering the condensed and liquefied organic solvent is provided outside the casting chamber 115. Further, it is preferable that a decompression chamber 120 for controlling the pressure of the back surface of the casting bead formed from the casting die 110 to the casting band 113 is disposed, and this is also used in this embodiment. .

  Further, blowers 121, 122, and 123 are provided to evaporate the solvent in the casting film 119. The mounting position of the blower is illustrated in the form in which the blower 121 is provided on the upper upstream side of the casting band 113, the blower 122 is provided on the downstream side, and the blower 123 is provided on the lower side of the casting band 113. is not. In addition, it is preferable that a wind shield device 124 is provided in order to suppress surface variation of the film surface caused by blowing dry air onto the cast film 119 immediately after formation.

  The crossover portion 130 is provided with a blower 131, and the ear clip device 142 downstream of the tenter device 2 is provided with a crusher 143 for finely cutting the side edge scraps of the cut film 141. .

  The drying chamber 145 is provided with a number of rollers 144, and an adsorption recovery device 146 for adsorbing and recovering the solvent gas generated by evaporation is attached. In FIG. 2, the cooling chamber 147 is provided downstream of the drying chamber 145, but a humidity control chamber (not shown) may be provided between the drying chamber 145 and the cooling chamber 147. A forced static eliminator (static neutralization bar) 148 for adjusting the charged voltage of the film 141 to be within a predetermined range (for example, −3 kV to +3 kV) is provided downstream of the cooling chamber 147. In FIG. 9, the forced static eliminating device 148 is illustrated on the downstream side of the cooling chamber 147, but is not limited to this installation position. Furthermore, in this embodiment, a knurling roller 149 for applying knurling to both edges of the film 141 by embossing is appropriately provided downstream of the forced static elimination device 148. The winding chamber 150 is provided with a winding roller 151 for winding the film 141 and a press roller 152 for controlling the tension at the time of winding.

  Next, an example of a method for producing a film using the solution casting apparatus 100 as described above will be described below. The dope 96 is always made uniform by the rotation of the stirrer 102. The dope 96 may be mixed with additives such as a plasticizer and an ultraviolet absorber during the stirring.

Then, the dope 96 is sent to the filtration device 104 by the pump 103 and filtered there, and then cast from the casting die 110 to the casting band 113. The driving of the rotating rollers 111 and 112 is preferably adjusted so that the tension generated in the casting band 113 is 10 ⁴ N / m to 10 ⁵ N / m. Further, the relative speed difference between the casting band 113 and the rotating rollers 111 and 112 is adjusted to be 0.01 m / min or less. The speed fluctuation of the casting band 113 is preferably 0.5% or less, and the meandering in the width direction when the casting band 113 rotates once is preferably 1.5 mm or less. In order to suppress this meandering, it is more preferable to provide a detector (not shown) for detecting the positions of both ends of the casting band 113 and to control the speed of the rotating roller by feedback control based on the measured value. Further, it is preferable to adjust the casting band 113 immediately below the casting die 110 so that the vertical position fluctuation accompanying the rotation of the rotary roller 111 is 200 μm or less. Further, the temperature of the casting chamber 115 is preferably set to −10 ° C. to 57 ° C. by the temperature control equipment 116. The solvent evaporated inside the casting chamber 115 is recovered by the recovery device 118 and then regenerated and reused as a dope preparation solvent.

  A casting bead is formed from the casting die 110 to the casting band 113, and a casting film 119 is formed on the casting band 113. The temperature of the dope 96 at the time of casting is preferably −10 ° C. to 57 ° C. In order to stabilize the casting bead, the back surface of the bead is preferably controlled to a predetermined pressure value by the decompression chamber 120. It is preferable that the bead back surface is depressurized by −10 Pa to −1500 Pa than the front surface. Further, it is preferable that a jacket (not shown) is attached to the decompression chamber 120 and the temperature is controlled so that the internal temperature is kept at a predetermined temperature. In order to keep the shape of the casting bead desired, it is preferable to attach a suction device (not shown) to the edge portion of the casting die 110. This edge suction air volume is 1 L / min. ~ 100 L / min. It is preferable that it is the range of these.

  After the casting film 119 has a self-supporting property, it is peeled off from the casting band 113 while being supported by the peeling roller 125 as the wet film 3. The amount of residual solvent at the time of stripping is preferably 20% by mass to 250% by mass based on the solid content. After that, after the transfer section 130 provided with a large number of rollers is conveyed, the wet film 3 is fed into the tenter device 2. In the transfer part 130, the drying of the wet film 3 is advanced by sending the drying air of desired temperature from the air blower 131. FIG. At this time, the temperature of the drying air is preferably 20 ° C to 250 ° C.

  The wet film 3 sent to the tenter device 2 is dried while its both ends are held by the clip 10 and conveyed. In the tenter device 2, the wet film 3 is stretched in the film width direction B (see FIG. 1). In at least any one of the crossover part 130 and the tenter device 2, it is preferable to stretch at least one direction of the wet film 3 in the casting direction and the width direction by 100.5% to 300%.

  The wet film 3 is dried to a predetermined residual solvent amount by the tenter device 2 and then sent out as a film 141 to the downstream side. Both edge portions of the film 141 are cut at both edges by the edge-cutting device 142, and the cut side edge portions are sent to the crusher 143 by a cutter blower (not shown). By the crusher 143, the side end portion is crushed into chips. Since this chip is reused for dope preparation, this method is effective in terms of cost. In addition, although it can also abbreviate | omit about the cutting process of this both-sides edge part, it is preferable to carry out in any one from the said casting process to the process of winding up the said film.

  On the other hand, in this embodiment, the film 141 from which both end portions have been cut off is sent to the drying chamber 145 and further dried. The temperature in the drying chamber 145 is not particularly limited. In the drying chamber 145, the film 141 is conveyed while being wound around the roller 144, and the solvent gas generated by evaporation here is adsorbed and recovered by the adsorption recovery device 146. The air from which the solvent component has been removed is blown again as dry air inside the drying chamber 145. The drying chamber 145 is more preferably divided into a plurality of sections in order to change the drying temperature. In addition, if a preliminary drying chamber (not shown) is provided between the ear opener 142 and the drying chamber 145 and the film 141 is preliminarily dried, the film temperature is prevented from rising sharply in the drying chamber 145. The shape change of the film 141 can be further suppressed.

  The film 141 is cooled to substantially room temperature in the cooling chamber 147. Note that a humidity control chamber (not shown) may be provided between the drying chamber 145 and the cooling chamber 147, and in this humidity control chamber, air adjusted to a desired humidity and temperature can be blown onto the film 141. It is preferable. Thereby, generation | occurrence | production of the curling of the film 141 and the winding defect at the time of winding can be suppressed.

  In the solution casting method, various steps such as a drying step and a side edge cutting and removing step are performed before the film (polymer film) peeled off from the support is wound up. In each of these processes or between each process, the film is mainly supported or conveyed by a roller. These rollers include a driving roller and a non-driving roller, and the non-driving roller is mainly used for determining a film conveyance path and improving conveyance stability.

  On the other hand, the drive roller is used to transmit drive to the film and convey it downstream, and a suction roller is usually used. In film transport in film formation, separation of transport tension may be necessary within each process such as casting process, stripping process, drying process, winding process, etc., and in that case, suction Separation of conveyance tension is achieved by applying a driving force to the film by a roller. This suction roller has a large number of air suction holes on the peripheral surface of the roller for adsorbing and transporting the film to itself.

  When a suction roller is used, the film is more easily deformed than a non-driven roller because a complex force whose directionality cannot be specified acts on the film. The film is also deformed by a difference in tension before and after the conveyance applied to the film. Furthermore, a large number of air suction holes are formed on the peripheral surface of the suction roller. If the film slips or contracts or deforms when the film is in contact with the edge of the suction holes, Fine scratches occur.

  The driving roller used in the transporting process is a roller whose peripheral surface is previously cured by nitriding treatment, cured chrome plating, or quenching treatment. The surface hardness of the circumferential surface is 500 to 2000 in terms of Vickers hardness. Or less, more preferably 800 or more and 1200 or less.

  The drive roller used is a suction roller, and this suction roller has a large number of air suction holes on its peripheral surface. At this time, the surface roughness Ry of the peripheral surface of the suction roller is preferably 0.3 μm or more and 1.0 μm or less, more preferably 0.5 μm or more and 0.8 μm or less. As for the surface roughness Ry of the peripheral surface, the surface roughness of the smooth portion having no hole in the roller is the peripheral surface roughness. The hole diameter is preferably 1 mm or more and 6 mm or less, more preferably 2 mm or more and 4 mm or less, and the chamfering amount of the hole is preferably 2% or more and 20% or less of the hole diameter.

  When using the suction roller, it is preferable to control the peripheral surface temperature, and therefore, it is preferable to have at least one temperature adjusting device for one suction roller. It is preferable to form the film while making the peripheral surface temperature of the roller higher than the film temperature immediately before contacting the suction roller.

  Further, the forcible static elimination device (static elimination bar) 148 sets the charged voltage while the film 141 is being conveyed to a predetermined range (for example, −3 kV to +3 kV). In FIG. 9, an example provided on the downstream side of the cooling chamber 147 is illustrated, but the position is not limited thereto. Furthermore, it is preferable to provide a knurling roller 149 to give knurling to both edges of the film 141 by embossing. In addition, it is preferable that the unevenness | corrugation of the knurled location is 1 micrometer-200 micrometers.

  Finally, the film 141 is taken up by the take-up roller 151 in the take-up chamber 150. At this time, it is preferable to wind the sheet while applying a desired tension with the press roller 152. More preferably, the tension is gradually changed from the start to the end of winding. The film 141 to be wound is preferably at least 100 m in the longitudinal direction (casting direction). Moreover, it is preferable that the width | variety of a film is 600 mm or more, and it is more preferable that they are 1400 mm or more and 1800 mm or less. The present invention is also effective when it is larger than 1800 mm. The present invention is also applied when manufacturing a thin film having a thickness of 15 μm or more and 100 μm or less.

  In the present invention, when casting the dope, a method of simultaneously laminating two or more types of dopes or co-casting sequentially may be used. When performing simultaneous lamination and co-casting, a casting die to which a feed block is attached may be used, or a multi-manifold casting die may be used. In the film composed of multiple layers by co-casting, it is preferable that either the thickness of the layer on the air surface side or the thickness of the layer on the support side is 0.5% to 30% of the thickness of the entire film. Furthermore, when performing simultaneous lamination co-casting, it is preferable that the high-viscosity dope is wrapped with the low-viscosity dope when the dope is cast from the die slit to the support. Moreover, when performing simultaneous lamination | stacking co-casting, it is preferable that the dope which contact | connects an external world among the beads formed from a die slit to a support body has a larger alcohol composition ratio than an internal dope.

  From casting die, decompression chamber, support structure, co-casting, peeling method, stretching, drying conditions for each process, handling method, curl, winding method after flatness correction, solvent recovery method, film recovery method The details are described in paragraphs [0617] to [0889] of Japanese Patent Application No. 2004-264464. These descriptions are also applicable to the present invention.

[Performance / Measurement method]
(Curl degree / thickness)
The performance of the wound cellulose acylate film and the measuring method thereof are described in paragraphs [0112] to [0139] of Japanese Patent Application No. 2004-264464. These can also be applied to the present invention.

[surface treatment]
It is preferable that at least one surface of the cellulose acylate film is surface-treated. The surface treatment is preferably at least one of vacuum glow discharge treatment, atmospheric pressure plasma discharge treatment, ultraviolet irradiation treatment, corona discharge treatment, flame treatment, acid treatment or alkali treatment.

[Functional layer]
(Antistatic, hardened layer, antireflection, easy adhesion, antiglare)
At least one surface of the cellulose acylate film may be undercoated.

  Furthermore, it is preferable to use the cellulose acylate film as a base film as a functional material provided with another functional layer. The functional layer is preferably provided with at least one layer selected from an antistatic layer, a cured resin layer, an antireflection layer, an easy adhesion layer, an antiglare layer and an optical compensation layer.

  A method for applying a surface-treated functional layer for realizing various functions and properties on a cellulose acylate film is described in Japanese Patent Application No. 2004-264464, from [0890] paragraph to [1087] paragraph. It is included. These are also applicable to the present invention.

(Use)
The cellulose acylate film is particularly useful as a polarizing plate protective film. Usually, two polarizing plates each having a cellulose acylate film bonded to a polarizer are bonded to a liquid crystal layer to produce a liquid crystal display device. However, the arrangement of the liquid crystal layer and the polarizing plate is not limited, and various known arrangements can be employed. Japanese Patent Application No. 2004-264464 describes in detail TN type, STN type, VA type, OCB type, reflective type, and other examples of liquid crystal display devices. This method can also be applied to the present invention. The application also describes a cellulose acylate film provided with an optically anisotropic layer and a cellulose acylate film provided with antireflection and antiglare functions. Furthermore, the use as an optical compensation film is also described as a biaxial cellulose acylate film imparting moderate optical performance. This can also be used as a polarizing plate protective film. These descriptions are also applicable to the present invention. Details are described in paragraphs [1088] to [1265] of Japanese Patent Application No. 2004-264464.

  Moreover, the cellulose triacetate film (TAC film) excellent in an optical characteristic can be obtained with the manufacturing method of this invention. The TAC film can be used as a polarizing plate protective film or a base film for a photographic photosensitive material. Furthermore, it can also be used as an optical compensation film for improving the viewing angle dependency of a liquid crystal display device for television applications. In particular, it is effective for applications that also serve as a protective film for a polarizing plate. Therefore, it is used not only for the conventional TN mode but also for the IPS mode, OCB mode, VA mode, and the like. Moreover, you may comprise a polarizing plate using the said film for polarizing plate protective films.

  The dry bearing 37 incorporated in the clip 10 is composed of DAIDINE DDK01 (trade name), sample A, sample B, sample C, and sample D manufactured by Daido Metal Industry Co., Ltd., and these five types of dry bearings. The clip 10 incorporating 37 is placed in an oven at 150 ° C., and an experiment is performed to open and close the flapper 32 continuously while applying a load using a cylinder. Then, the inner peripheral surface of the dry bearing 37 is rubbed with black paper. The amount of deposits scraped off from the inner peripheral surface and adhered to the black paper was examined. The experiment was performed with and without fresh air blowing to the clip 10. Note that sample A is Dydyne DDU01 (trade name) manufactured by Daido Metal Industry Co., Ltd. used for the current clip, sample B is DTK52 (trade name) manufactured by Daido Metal Industry Co., Ltd., and sample C is Aurum (registered trademark) JCF3030 (trade name) manufactured by Mitsui Chemicals, Inc. and sample D are Polypenco (registered trademark) PEEK (registered trademark) PK-450 (trade name) manufactured by Nippon Polypenco Co., Ltd.

  The results of this experiment are shown in Table 1. In Table 1, as an evaluation of the amount of dust generation, 0 to 2 deposits on the black paper are rated as ◎, 3 to 9 are rated as と し, and 10 or more are marked as ×. . In addition, as an evaluation of the operability of the flapper 32, the case where the open / close operation of the flapper 32 is not possible is 445,000 or more, ◎, the case where it is 3001 or more and less than 445,000 is given as と し, and the case where the number is 3000 times or less. And

  As a result of this experiment, when the dry bearing 37 is composed of DAIDINE DDK01 (trade name), sample B, and sample D manufactured by Daido Metal Industry Co., Ltd., regardless of whether fresh air is sprayed onto the clip 10 or not. The dust generation amount of the dry bearing 37 is small (3 to 9), and the flapper 32 can be operated more than 445,000 times, and the operability of the flapper 32 is also good. Further, when the dry bearing 37 is composed of the sample C, the amount of dust generated by the dry bearing 37 is small (3 to 9 pieces), and when the fresh air is not blown out to the clip 10, the operation of the flapper 32 is performed. Although the possible number of times was 3001 or more and less than 445,000 times, when there was a fresh air blowout to the clip 10, the operable number of times of the flapper 32 was 445,000 times or more, and the operability of the flapper 32 was good. Further, in the case where the sample A is used, when there is no blowing of fresh air to the clip 10, the operable number of times of the flapper 32 is 3000 times or less, but there is injection of fresh air to the clip 10. In this case, the operable number of times of the flapper 32 is 445,000 times or more, and the operability of the flapper 32 is good. In addition, 445000 times is the frequency | count of operation | movement of the flapper 32 when the tenter apparatus 2 is used for one year.

  As described above, Dydyne DDK01 (trade name) manufactured by Daido Metal Industry Co., Ltd., and DTK52 (trade name) manufactured by Daido Metal Industry Co., Ltd., which are materials that do not deteriorate due to the volatile components volatilized from the wet film 3. A flapper made up of Aurum (registered trademark) JCF3030 (trade name) manufactured by Mitsui Chemicals, Inc. and Polypenco (registered trademark) PEEK (registered trademark) PK-450 (trade name) manufactured by Nippon Polypenco Co., Ltd. 32 can improve the operation frequency of the flapper 32, so that the dry bearing 37 is deteriorated and the flapper 32 cannot be rotated, thereby preventing the wet film 3 from being poorly gripped. it can. Further, the fresh air is blown out from the outlet 56 provided at the tip of the first and second clip covers 51, 52 toward the clip 10, mainly toward the flapper 32, so that the flapper 32, the mounting shaft 35, and the dry bearing. TPP does not adhere to 37, etc., so that the shavings of the dry bearing 37 and the TPP are not combined into a lump, and the gripper of the wet film 3 caused by the flapper 32 being unable to rotate is prevented. Can be prevented. In addition, since the first and second clip covers 51 and 52 are provided so as to cover the frame 31 and the flapper 32 of the clip 10, the drying air for drying the wet film 3 is prevented from hitting the frame 31 and the flapper 32. The shavings of the dry bearing 37 and the TPP are not combined to form a lump, and the gripping failure of the wet film 3 that occurs when the flapper 32 cannot rotate can be more reliably prevented.

Next, the Example regarding the film manufacture of this invention is described based on the flow of operation | movement of the dope manufacturing equipment 70 and the solution film-forming equipment 100. FIG. First, the formulation for preparing the polymer solution (dope) used for film production is shown below.
[composition]
Cellulose triacetate (substitution degree 2.84, viscosity average polymerization degree 306, water content 0.2 mass%, viscosity 6 mass% in dichloromethane solution 315 mPa · s, average particle diameter 1.5 mm with standard deviation 0.5 mm Some powders) 100 parts by mass dichloromethane (first solvent) 320 parts by mass methanol (second solvent) 83 parts by mass 1-butanol (third solvent) 3 parts by mass plasticizer A (triphenyl phosphate) 7.6 parts by mass Plasticizer B (diphenyl phosphate) 3.8 parts by mass UV agent a: 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole 0.7 part by mass UV agent b: 2 ( 2′-Hydroxy-3 ′, 5′-di-tert-amylphenyl) -5-chlorobenzotriazole 0.3 parts by mass of citric acid ester mixture (citric acid, citric acid Monoethyl ester, citric acid diethyl ester, citric acid triethyl ester mixture) 0.006 parts by weight fine particles (silicon dioxide (particle size 15 nm), Mohs hardness: about 7) 0.05 parts by weight

[Cellulose triacetate]
The cellulose triacetate used here has a residual acetic acid content of 0.1% by mass or less, a Ca content of 58 ppm, a Mg content of 42 ppm, a Fe content of 0.5 ppm, a free acetic acid of 40 ppm, It contained 15 ppm of sulfate ions. The degree of substitution of the 6-position acetyl group was 0.91, 32.5% of the total acetyl. Moreover, the acetone extraction part which extracted this TAC with acetone was 8 mass%, and the weight average molecular weight / number average molecular weight ratio was 2.5. The obtained TAC has a yellow index of 1.7, a haze of 0.08, a transparency of 93.5%, a Tg (glass transition point; measured by DSC) of 160 ° C., and a crystallization calorific value of It was 6.4 J / g. This TAC is synthesized using cellulose collected from cotton as a raw material. In the following description, this is called cotton raw material TAC.

(1-1) Dope Preparation A dope 96 was prepared using a dope manufacturing facility 70 shown in FIG. In a 4000 L stainless steel dissolution tank 73 having a stirring blade, the plurality of solvents were mixed and stirred well to obtain a mixed solvent. In addition, all the solvents used that the water content is 0.5 mass% or less. Next, TAC flaky powder was gradually added from the hopper 74. The TAC powder was put into the dissolution tank 73 and dispersed for 30 minutes under a predetermined stirring condition by a first stirrer 79 as an anchor blade and a second stirrer 81 as a dissolver type eccentric stirrer. The temperature at the start of dispersion was 25 ° C., and the final temperature reached 48 ° C. Further, the additive solution prepared in advance was adjusted from the additive tank 75 to the solution tank 73 by adjusting the amount of liquid fed by the valve 76 so that the total amount was 2000 kg. After the dispersion of the additive solution was completed, the peripheral speed of the first stirrer 79 was set to a predetermined value and stirred for another 100 minutes to swell the TAC flakes to obtain a swelling liquid 82. The tank was pressurized to 0.12 MPa with nitrogen gas until the end of swelling. At this time, the inside of the dissolution tank 73 was kept in a state of no problem in terms of explosion prevention because the oxygen concentration was less than 2 vol%. The amount of water in the swelling liquid was 0.3% by mass.

(1-2) Dissolution / Filtration The swelling liquid 82 was sent from the dissolution tank 73 to the heating device 86 which is a jacketed pipe using a pump 85. The swelling liquid 82 was heated to 50 ° C. with the heating device 86 and further heated to 90 ° C. under a pressure of 2 MPa to completely dissolve. The heating time at this time was 15 minutes. Next, the temperature of the dissolved liquid was lowered to 36 ° C. with a temperature controller 87 and passed through a filtration device 88 equipped with a filter medium having a nominal pore diameter of 8 μm to obtain a dope (hereinafter referred to as pre-concentration dope). At this time, the primary pressure in the filtration device 88 was set to 1.5 MPa, and the secondary pressure was set to 1.2 MPa. As the filter, housing, and piping exposed to a high temperature, those having a jacket made of Hastelloy alloy having excellent corrosion resistance and circulating a heat transfer medium for heat insulation heating were used.

(1-3) Concentration / Filtration / Defoaming / Additive The dope before concentration thus obtained is flash-evaporated in a flash device 91 at 80 ° C. and normal pressure, and the evaporated solvent is removed by a condenser. Condensed and recovered. In this way, the dope concentration was adjusted. The condensed solvent was recovered by the recovery device 92 to be reused as a dope preparation solvent, regenerated by the regenerator 93, and then sent to the solvent tank 71. In the recovery device 92 and the regenerator 93, distillation or dehydration is performed. The flash tank of the flash device 91 was provided with a stirrer equipped with an anchor blade on a stirring shaft, and the flashed dope was stirred by this stirrer to perform defoaming. The temperature of the dope in this flash tank was 25 ° C., and the average residence time of the dope in the tank was 50 minutes. The shear viscosity measured at 25 ° C. after collecting this dope was 450 Pa · s at a shear rate of 10 ⁻¹ (sec ⁻¹ ).

  Next, bubbles were removed by irradiating the dope with weak ultrasonic waves. Then, the filtration apparatus 95 was passed in the state pressurized to 1.5 MPa using the pump 94. FIG. In the filtering device 95, first, a sintered fiber metal filter having a nominal pore diameter of 10 μm was passed, and then a sintered fiber filter having a same pore size of 10 μm was passed. Respective primary pressures were 1.5 MPa and 1.2 MPa, and secondary pressures were 1.0 MPa and 0.8 MPa. The dope temperature after filtration was adjusted to 36 ° C., and the dope 96 was fed into a 2000 L stainless steel stock tank 90 and stored therein. The stock tank 90 has a stirrer having an anchor blade on the central axis, and the inside is constantly stirred by this stirrer. Incidentally, no problems such as corrosion occurred at all in the wetted part of the dope from the pre-concentration dope to the preparation of the dope 96.

  Moreover, the mixed solvent A of 86.5 mass parts of dichloromethane, 13 mass parts of acetone, and 0.5 mass part of 1-butanol was produced.

(1-4) Discharge / Previous Addition / Casting / Bead Decompression A film 141 was manufactured using the solution casting apparatus 100 shown in FIG. The dope 96 in the stock tank 90 was sent to the filtration device 104 by the pump 103. This pump 103 has a function of increasing the pressure on the primary side of the pump 103. The pump 103 is fed with feedback control to the upstream side of the pump 103 by an inverter motor so that the pressure on the primary side becomes 0.8 MPa. . The pump 103 has a capacity efficiency of 99.2% and a discharge rate variation rate of 0.5% or less. The discharge pressure was 1.5 MPa. Then, the dope 96 that passed through the filtration device 104 was fed to the casting die 110.

  The casting die 110 has a width of 1.8 m and is cast by adjusting the flow rate of the dope 96 at the discharge port of the casting die 110 so that the film 141 after drying has a thickness of 80 μm. It was. The casting width of the dope 96 from the discharge port of the casting die 110 was 1700 mm. In order to adjust the temperature of the dope 96 to 36 ° C., a jacket (not shown) is provided on the casting die 110 and the inlet temperature of the heat transfer medium supplied into the jacket is set to 36 ° C.

  The casting die 110 and the piping were all kept at 36 ° C. during operation. The casting die 110 is a coat hanger type die. And as this casting die | dye 110, the thickness adjustment bolt was provided in 20 mm pitch, and the thing equipped with the automatic thickness adjustment mechanism by a heat bolt was used. The heat bolt can set a profile according to the pumping amount by a preset program, and feedback control is performed by an adjustment program based on a profile of an infrared thickness gauge (not shown) installed in the solution casting apparatus 100. Also used were those having possible performance. In the film 141 excluding the casting side end 20 mm, the difference in thickness between any two points 50 mm apart was adjusted to be within 1 μm, and the thickness variation in the width direction was adjusted to 3 μm / m or less. The overall thickness was adjusted to ± 1.5% or less.

  In addition, a decompression chamber 120 for decompressing this portion was installed on the primary side of the casting die 110. The degree of decompression of the decompression chamber 120 is adjusted so that a pressure difference of 1 Pa to 5000 Pa is generated before and after the casting bead from the casting die 110 until reaching the casting start position PS. Made according to speed. At that time, the pressure difference on both sides of the bead was set so that the length of the bead became a predetermined value. Further, the decompression chamber 120 was provided with a mechanism that can be set to a temperature higher than the condensation temperature of the gas around the casting portion. Labyrinth packings (not shown) were provided on the front and back sides of the bead at the discharge port of the casting die 110, and openings were provided on both ends of the discharge port. Further, the casting die 110 is attached with an edge suction device (not shown) for adjusting the disturbance of both edges of the casting bead.

(1-5) Casting die The material of the casting die 110 is a two-layer stainless steel having a thermal expansion coefficient of 2 × 10 ⁻⁵ (° C. ⁻¹ ) or less. This is a material that has almost the same corrosion resistance as that of SUS316 in the forced corrosion test with an aqueous electrolyte solution, and it can be pitted at the gas-liquid interface even if it is immersed in a mixed solution of dichloromethane, methanol, and water for 3 months. Corrosion resistance that does not cause (perforation). The finishing accuracy of the wetted surface of the casting die 110 was 1 μm or less in terms of surface roughness, the straightness was 1 μm / m or less in any direction, and the slit clearance was adjusted to 1.5 mm. About the corner | angular part of the liquid-contacting part of the lip | tip end of the casting die 110, it is processed so that R may be 50 micrometers or less over the slit full width. The shear rate inside the casting die 110 was in the range of 1 (1 / sec) to 5000 (1 / sec). Further, a WC (tungsten carbide) coating was applied to the lip end of the casting die 110 by a thermal spraying method to provide a cured film.

  Further, the mixed solvent A for solubilizing the dope 96 is provided at both ends of the casting bead at the discharge port of the casting die 110 in order to prevent the flowing out dope 96 from being locally dried and solidified. And 0.5 ml / min. Supplied one by one. The pulsation rate of the pump supplying the mixed solvent A was 5% or less. Further, the pressure on the back side of the bead was reduced by 150 Pa from the front side by the decompression chamber 120. In addition, a jacket (not shown) was attached in order to keep the internal temperature of the decompression chamber 120 constant at a predetermined temperature. A heat transfer medium adjusted to 35 ° C. was supplied into the jacket. The edge suction device is 1 L / min. ~ 100 L / min. The edge suction air volume can be adjusted so as to fall within the range of 30 L / min. ~ 40 L / min. It adjusted suitably so that it might become the range of.

(1-6) Metal Support A casting band 113 as a stainless steel endless band having a width of 2.1 m and a length of 70 m was used as a support. The casting band 113 was polished so that the thickness was 1.5 mm and the surface roughness was 0.05 μm or less. The material is made of SUS316 and has sufficient corrosion resistance and strength. The thickness unevenness of the entire casting band 113 was 0.5% or less. The casting band 113 was conveyed by two rotating rollers 111 and 112. At that time, the relative speed difference between the casting band 113 and the rotating rollers 111 and 112 is 0.01 m / min or less so that the tension in the conveying direction of the casting band 113 is 1.5 × 10 ⁵ N / m ^2. It was adjusted to become. Moreover, the speed fluctuation of the casting band 113 was 0.5% or less. Further, both end positions of the casting band 113 were detected and controlled so that the meandering in the width direction of one rotation was limited to 1.5 mm or less. Further, the positional variation in the vertical direction between the lip tip of the casting die 110 and the casting band 113 immediately below the casting die 110 was set to 200 μm or less. The casting band 113 is installed in a casting chamber 115 having wind pressure fluctuation suppressing means (not shown). A dope 96 was cast from the casting die 110 on the casting band 113.

As the rotating rollers 111 and 112, those capable of feeding a heat transfer medium therein were used so that the temperature of the casting band 113 could be adjusted. A 5 ° C. heat transfer medium was passed through the rotating roller 111 on the casting die 110 side, and a 40 ° C. heat transfer medium was passed through the other rotating roller 112 for drying. The surface temperature of the central part of the casting band 113 immediately before casting was 15 ° C., and the temperature difference between both side ends was 6 ° C. or less. The casting band 113 preferably has no surface defects, has no pinholes of 30 μm or more, has 1 pinhole of 10 μm to 30 μm / m ² or less, and ² pinholes of less than 10 μm / Those with m ² or less were used.

(1-7) Casting drying The temperature of the casting chamber 115 was kept at 35 ° C. by the temperature control equipment 116. To the casting film 119 formed from the dope 96 cast on the casting band 113, the blower 121, 122 first sent the drying air flowing parallel to the casting film 119 to dry it. . The overall heat transfer coefficient from the dry air to the cast film 119 was 24 kcal / m ² · hr · ° C. The temperature of the drying air was 135 ° C. on the upstream side of the upper part of the casting band 113 and 140 ° C. on the downstream side. The lower part of the casting band 113 was blown from the blower 123 so that the temperature was 65 ° C. The saturation temperature of each drying wind was around -8 ° C. The oxygen concentration in the dry atmosphere on the casting band 113 was kept at 5 vol%. In order to maintain this oxygen concentration at 5 vol%, the air was replaced with nitrogen gas. Further, in order to condense and recover the solvent in the casting chamber 115, a condenser (condenser) 117 was provided, and its outlet temperature was set to -10 ° C.

In order to prevent the air flow from directly hitting the dope 96 and the casting film 119 during the casting time of 5 seconds from the casting start point PS, a wind shield device 124 is provided, and the static pressure near the casting die 110 is provided. The fluctuation was suppressed to ± 1 Pa or less. When the solvent ratio in the casting film 119 reached 50 mass% on the dry basis, the film was peeled off as the wet film 3 while being supported by the peeling roller 125 from the casting band 113. The solvent content based on the dry weight standard is a value obtained by {(xy) / y} × 100, where x is the film weight at the time of sampling and y is the weight after the sampling film is dried. . The stripping tension at this time is 1 × 10 ² N / m ² , and the stripping speed (stripping roller draw) with respect to the speed of the casting band 113 is 100.1% to 110% in order to suppress stripping failure. Adjusted appropriately within the range. The surface temperature of the peeled film was 15 ° C. The drying speed on the casting band 113 was 60% by mass on the basis of dry weight reference solvent / min. Met. The solvent gas generated by the drying was condensed and liquefied with a -10 ° C. condenser and recovered with a recovery device (not shown). The recovered solvent was adjusted so that the water content was 0.5% or less. The drying air from which the solvent has been removed is heated again and reused as drying air. The wet film 3 was conveyed through the transfer section 130 and sent to the tenter device 2. During this conveyance, 40 ° C. dry air was sent from the blower 131 to the wet film 3. Note that a predetermined value of tension is applied to the wet film 3 while being transported by the rollers of the crossing section 130.

(1-8) Tenter Transport / Drying / Ear Cutting The wet film 3 sent to the tenter device 2 is transported through the tenter device 2 with its both ends fixed by the clip 10 and dried by drying air. At this time, the dry air inside each of the drying units 2a to 2c is sent to the TPP removal unit 65, and the TPP in the dry air is removed by the TPP removal unit 65. The fresh air taken in from the air merges, and the air volume is controlled by adjusting the throttle of the air volume adjusting valve 62 and sent to the fresh air supply pipe 55 provided in each of the drying units 2a to 2c. Then, the fresh air that has passed through the fresh air supply pipe 55 is blown out toward the clip 10, mainly the flapper 32, from the blowout port 56 provided at the tip of the first and second clip covers 51 and 52. At that time, the amount of air sent to the fresh air supply pipe 55 is adjusted by the air volume adjusting valve. Further, the speed fluctuation of the driving sprockets 11 and 12 was 0.5% or less. The gas composition of the drying air was set to a saturated gas concentration at −10 ° C. The average drying speed in the tenter apparatus 2 was 120% by mass (dry weight reference solvent) / min. The conditions of the drying zone were adjusted so that the residual solvent amount of the film 141 at the tenter outlet 17 of the tenter apparatus 2 was 7% by mass. In the tenter apparatus 2, stretching in the film width direction B (see FIG. 1) was performed while the wet film 3 was being conveyed. In addition, when the width | variety of this wet film 3 before extending | stretching was 100%, it extended | stretched so that the width | variety after extending | stretching might be 103%. The stretch ratio (tenter-driven draw) from the peeling roller 125 to the entrance of the tenter device 2 was 102%. The ratio of the length from the clip nipping start position to the nipping release position with respect to the length from the tenter inlet to the outlet of the tenter device 2 was 90%.

  Then, the ears of the film 141 were cut by the ear-cleaver 142 within 30 seconds from the tenter outlet 17 of the tenter device 2.

(1-9) Post-drying / static elimination The film 141 was dried at high temperature in the drying chamber 145. The drying chamber 145 was divided into four sections, and drying air at 120 ° C., 130 ° C., 130 ° C., and 130 ° C. was supplied from a blower (not shown) from the upstream side. The transport tension of the film 141 by the roller 144 was set to 100 N / m, and the film was dried for about 10 minutes until the residual solvent amount finally reached 0.3% by mass. The wrap angle (film winding center angle) of the roller 144 was 90 ° and 180 °. The material of the roller 144 was made of aluminum or carbon steel, and the surface was hard chrome plated. As the surface shape of the roller 144, a flat surface and a surface formed by matting by blasting were used. All film position fluctuations due to the rotation of the roller 144 were 50 μm or less. The roller deflection at a tension of 100 N / m was selected to be 0.5 mm or less.

  The solvent gas contained in the drying air was adsorbed and recovered using an adsorption recovery device 146. The adsorbent used here was activated carbon, and desorption was performed using dry nitrogen. The recovered solvent was adjusted to a water content of 0.3% by mass or less and reused as a dope preparation solvent. Since the drying air contains solvent gas, plasticizer, UV absorber, and other high-boiling substances, these were removed by a cooler and a pre-adsorber for cooling and removing them, and recycled and used. And adsorption / desorption conditions were set so that VOC (volatile organic compound) in the outdoor exhaust gas was finally 10 ppm or less. Moreover, the solvent amount collect | recovered by a condensation method among all the evaporation solvents was 90 mass%, and most of the remainder was collect | recovered by adsorption collection.

  The dried film 141 was conveyed to a first humidity control chamber (not shown). A drying air of 110 ° C. was supplied to the transition portion between the roller dryer and the first humidity control chamber. Air having a temperature of 50 ° C. and a dew point of 20 ° C. was supplied to the first humidity control chamber. Further, the film 141 was transported to a second humidity control chamber (not shown) for suppressing the curling of the film 141. In the second humidity control chamber, air of 90 ° C. and humidity 70% was directly applied to the film 141.

(1-10) Knurling and Winding Conditions The film 141 after humidity control was cooled to 30 ° C. or lower in the cooling chamber 147, and then subjected to ear cutting with a second ear cutting device. A forced charge removal device (charge removal bar) 148 was installed so that the charged voltage of the film 141 during conveyance was always in the range of −3 kV to +3 kV. Further, knurling was applied to both ends of the film 141 by a knurling roller 149. The knurling is applied by embossing from one side of the film 141, the width for applying the knurling is 10 mm, and the knurling is applied by the knurling application roller 149 so that the height of the unevenness is 12 μm higher than the average thickness of the film 141. The pressing pressure was set.

  Then, the film 141 was conveyed to the winding chamber 150. The winding chamber 150 is maintained at an apparatus internal temperature of 28 ° C. and a humidity of 70%. Further, an ion wind static elimination device (not shown) was also installed in the winding chamber 150 so that the charged voltage of the film 141 was −1.5 kV to +1.5 kV. The product width of the film 141 thus obtained is 1475 mm. The diameter of the winding roller 151 in the winding chamber 150 is 169 mm. The tension pattern was such that the winding start tension was 300 N / m and the winding end was 200 N / m. The total length of the wound film 141 was 3940 m. The fluctuation range of winding deviation (sometimes referred to as oscillating width) during winding was ± 5 mm, and the winding deviation period with respect to the winding axis was 400 m. The pressing pressure of the press roller 152 against the winding shaft was set to 50 N / m. The temperature of the film 141 at the time of winding was 25 ° C., the water content was 1.4% by mass, and the residual solvent amount was 0.3% by mass. The average drying rate was 20% by mass (dry weight reference solvent) / min throughout the entire process. Moreover, there was no winding looseness and wrinkles, and no winding slip occurred in the impact test at 10G. Moreover, the external appearance of the film roll was also favorable.

  The film roll was stored in a storage rack at 25 ° C. and a relative humidity of 55% (hereinafter referred to as 55% RH) for one month and further examined in the same manner as described above. As a result, no change was observed. Further, no film adhesion was observed in the film roll. In addition, after the film 141 was formed, the cast film formed from the dope 96 was not peeled off on the casting band 113 at all. Further, the TPP is not attached to the flapper 32 or the dry bearing 37 of the clip 10, the scraped scrap of the dry bearing 37 and the TPP are not combined into a lump, and the flapper 32 rotates smoothly. In addition, no grip failure of gripping the wet film 3 by the clip 10 was observed.

  In the above embodiment, the dry bearing 37 is attached to the flapper 32, and the attachment shaft 35 is inserted into the attachment shaft insertion hole 34 a of the flapper attachment portion 34 and the dry bearing 37, and then the attachment shaft 35 is fixed by the fixing pin 36. Although fixed to the flapper mounting portion 34, the present invention is not limited to this, and it is sufficient that the flapper 32 can be rotated by the dry bearing 37. For example, the mounting shaft 35 is fixed to the flapper 32, and the flapper mounting portion 34. A dry bearing 37 may be attached.

  Moreover, in the said embodiment, the fresh-air supply pipe | tube 55 is a total of six one each for each drying part 2a-2c of the 1st clip cover 51, and each drying part 2a-2c of the 2nd clip cover 52. However, as long as fresh air can be supplied into the tenter device 2, the number of the tenter devices 2 is not limited and can be changed as appropriate.

It is a top view which shows the tenter apparatus which implemented this invention. It is a perspective view which shows a clip. It is a disassembled perspective view which shows a clip. It is a side view which shows the state just before the grip start of a clip. It is a side view which shows the state immediately after the start of holding | grip of a clip. It is a side view which shows a clip, a 1st clip cover, and a fresh air supply pipe | tube. It is a schematic side view which shows a tenter apparatus, the 1st, 2nd clip cover, and a TPP removal unit. It is a top view which shows dope manufacturing equipment. It is a top view which shows solution casting equipment.

Explanation of symbols

2 Tenter device 3 Wet film (film)
10 clips 31 frames (clip body)
31a Film holding surface (film placement part)
32 Flapper (grip lever)
32a Contact head 32b Grip portion 32c Rotating shaft portion 32d Mounting hole 33 Rail mounting portion 34 Flapper mounting portion 35 Mounting shaft 36 Fixing pin 37 Dry bearing 51 First clip cover (clip cover)
52 Second clip cover (clip cover)
55 Fresh air supply pipe 56 Outlet 57 Exhaust cover 65 TPP removal unit 70 Dope production equipment 100 Solution film production equipment

Claims (4)

In the tenter device of the solution casting equipment that grips and conveys both side edges of the film with clips and dries the film,
Between a clip body having a film mounting portion on which a side edge portion of the film is placed, a holding position for holding the side edge portion of the film between the film mounting portion, and a retracted position retracted from the holding position The clip is composed of a swingable gripping lever, a mounting shaft that swingably mounts the gripping lever to the clip body, and a dry bearing that supports the mounting shaft.
A tenter device for a solution casting apparatus, wherein the dry bearing is made of a material having self-lubricating property and less dust generation due to wear.   2. The tenter apparatus for a solution casting apparatus according to claim 1, wherein the dry bearing is composed of a tetrafluoroethylene resin not containing lead and a solid lubricant.   A clip cover that is provided in a travel area of the clip at the gripping position and covers the clip, and a blower unit that blows air into the clip cover and prevents intrusion of dry air in the tenter to the clip at the gripping position. The tenter apparatus for a solution casting apparatus according to claim 1 or 2, wherein The tenter apparatus for a solution casting apparatus according to any one of claims 1 to 3, wherein the film is a cellulose acylate film.

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