JP2005238801A - Method and device for pneumatic sending of selvage waste of film and method for producing cellulose acetate film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for a pneumatic sending of a selvage waste cut from a film without causing clogging. <P>SOLUTION: A selvage waste 36a cut from a film 36 by a selvage cutting device is pneumatically sent to a recovering silo by the 1st pneumatic sending device 27. The selvage 36c is sucked by a sucking duct 47 under holding by a pair of feed rollers 81. A tension in a sending direction of the selvage waste 36c introduced by the feed roller 81 is adjusted to 3-45 N/m<SP>2</SP>by the feed roller 82, and the pressure of holding of the selvage waste 36c is adjusted to 0.05-0.4 MPa by the pair of feed rollers 81. When a speed of sending the film 36 is increased stepwise by 5-30 m/min, the tension and the holding pressure are decreased stepwise. The selvage waste 36c is cut into slits by a rotary cutter 48 and pneumatically sent under controlled electrical charge and broken into small pieces by a cutting blower 52. Cutting of the selvage waste 36c and clogging of the pipelines are suppressed during a process from selvage cutting to recovering. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a method and apparatus for blowing ear dust obtained by cutting a side end portion (ear portion) from a film of polymer or the like that is continuously conveyed, and a method for producing a cellulose acylate film.

  In recent years, thin transparent polymer films have been used as protective films for polarizing plates of liquid crystal displays, optical compensation films such as retardation plates, plastic substrates, photographic supports, moving picture cells and optical filters, and optical materials such as OHP films. As demand increases.

  Examples of the raw material for the polymer film used in the above fields include cellulose acylate, norbornene resin, acrylic resin, polyarylate resin, polycarbonate resin, and the like. From the viewpoint of productivity and material price, cellulose acylate is used. Mainly used. In particular, a film of cellulose triacetate (TAC) has particularly high transparency, has a small optical anisotropy, and has a low retardation value Re, Rth, so that it is particularly advantageously used for optical applications.

  As a method for producing these polymer films, various film forming techniques such as a solution film forming method, a melt film forming method and a rolling method can be used, but in order to obtain good flatness and low optical anisotropy. The solution casting method is particularly suitable.

  The solution casting method is a polymer solution in which a flaky polymer is dissolved in a solvent, and various additives such as a plasticizer, an ultraviolet absorber, a deterioration preventing agent, a slipping agent, and a peeling accelerator are added as necessary. (Hereinafter referred to as a dope), and after the dope is cast on a support such as an endless metal belt or a rotating drum by a dope supply means (hereinafter referred to as a casting die), the dope is predetermined on the support. In this method, the self-supporting film to which the rigidity is imparted is peeled off from the support, and then the solvent is removed by passing through the drying section by various conveying means such as a tenter device. is there. The formed film is dried and wound on a take-up reel.

  In the production of such a film, the ear portion of the film is compared with the central portion between the two end portions due to the contact angle of the dope against the casting support, the surface tension of the casting membrane, uneven drying during drying, etc. The thickness tends to fluctuate greatly. As a result, curl, wrinkles, and the like are generated during conveyance in the ear part of the film or in the range from the ear part to the product part, and it becomes impossible to manufacture a stable film. Therefore, usually, a cutting device for cutting the ear portion along the film transport direction is provided at an arbitrary position after the film is peeled off from the support and then wound up, and the ear portion is removed. As a result, the film is stably and continuously manufactured, and a film whose width is accurately controlled and maintained is obtained as a product.

  The said cutting device is provided with the cutting blade provided with the upper round blade and the lower round blade. Then, while feeding the film, the cutting blade is moved from the side edge of the film toward the center to cut to a predetermined position, and when the film reaches the predetermined position, the movement is stopped so that both ears of the film are continuously Disconnect. The cut ear part (hereinafter referred to as “ear waste”) is sent to the recovery part by an air blower, recovered, and reused as a raw material.

  The above-described air feeding device includes an air feeding pipe, and the ear dust passes through the air feeding pipe and is sent to the collection unit. In order to prevent clogging of the strip-shaped ear dust, for example, the ear dust may be cut into a narrower strip by a slitter and air-fed.

  In the air blowing device, a suction duct for feeding the ear dust into the air feeding pipe is provided, and a feed roller pair is provided in the vicinity of the suction port of the suction duct, and the feed roller pair is guided into the suction duct. The film is transported to the air pipe. A rubber material is usually used as the surface material of the feed roller pair.

  However, if there is a bent portion such as an L-shape or a T-shape in the air-feeding pipe, the ear dust becomes bellows at the stepped portion of the flange at the bent portion, which may clog the pipe. When the clogging of the ear dust occurs, it becomes impossible to send the ear dust, so that the ear cutting process at the upstream portion becomes impossible. If it becomes impossible to cut the ears, in the worst case, it will lead to the stoppage of casting, and there is a problem that productivity is significantly impaired. Then, the method etc. which cut | disconnect an ear waste in the direction along the width direction, make it a strip shape, and wind this strip-like ear waste etc. are proposed (for example, refer patent document 1).

Japanese Patent Laying-Open No. 2003-291091 (page 3-4, FIG. 3)

  However, the following problem still remains as a method of cutting the ear dust in a direction along the width direction into a strip shape, and blowing the strip ear dust, which is an extremely thin film having a thickness of, for example, 80 μm or less. This is noticeable when the thickness is too thin. One is that the tension in the feeding direction by the feed roller pair used in the air feeding device is not controlled to a preferable value, so that the feeding into the air feeding pipe cannot be performed satisfactorily and ear dust is generated. The problem is that the pipe is clogged, which may cause the ear dust to be poorly ventilated. The poor air feeding in this case leads to a phenomenon that the film is cut in the edge cutting process or the conveying process using the feed roller pair.

  The second problem is that the feed roller pair causes a conveyance failure due to friction with the film, and this is prominent when a pin tenter or the like remains on the film in a tenter device or the like in the film forming process. is there. The third problem is that when the conveying speed is increased in order to improve productivity, the film is easily cut at the feed roller pair. And since the solvent remains in the film, it is desirable that the air blow in the air feeding device is a closed circulation system. However, when the closed circulation system is used, the ear dust on the secondary side of the cutting device for the ear-cutting device is used. The fourth problem is that the suction pressure of the film is reduced, and as a result, a film chute defect occurs in the cutting device.

  The present invention is for solving the above-mentioned problems, and provides an ear dust transport method and apparatus capable of reliably transporting an ear dust of a thin film of 80 μm or less, and a method for producing a cellulose triacetate film. With the goal.

In this invention, it has the 1st process which winds the film side edge part cut | disconnected from the film conveyed continuously in a long shape, and winds the said side edge part to a collection | recovery part using the said 1st process. In the feeding method, a roller pair for sandwiching the side end portion is provided in the first step, and the side end portion immediately before being sandwiched by the roller pair is 3 N / m ² in the longitudinal direction. The structure is characterized in that a tension of 45 N / m ² or less can be applied.

  The outer peripheral surface of at least one roller of the roller pair is made of rubber or metal having irregularities for suppressing slippage of the side end portion, and the narrowing pressure of the roller pair with respect to the side end portion is 0.05 MPa or more The pressure is preferably 0.4 MPa or less. Further, when the speed at which the film is conveyed is changed so as to increase stepwise in a unit of 5 m / min or more and within 30 m / min, the tension or the pinching pressure by the roller pair is changed according to the change of the speed. It is preferable to make it small.

  Moreover, it has a 2nd process of cut | disconnecting the side edge part of the said elongate object into a cut piece small piece by a cutting | disconnection means, and it is preferable to make the wind distance of the side edge part to this 2nd process into 20 m or less.

  And at least one of the side end portion and the side end portion piece is blown in an arbitrary direction except for the anti-conveying direction and the direction along the width direction of the film from which the side end portion is cut off. Is more preferable. It is preferable that the charged voltage value of at least one of the side end portion and the side end piece is set to −5 kV or more and 5 kV or less by the static electricity removing means. Moreover, when the film is a cellulose acylate film, an excellent effect can be obtained by the air blowing method of the present invention.

Furthermore, the present invention has a first air supply path for air-feeding the side end portion cut from the continuously conveyed film in a long shape, and a recovery unit provided downstream of the first air supply unit In the air feeding device that winds the side end portion, a roller pair for sandwiching the side end portion is provided in the first air sending path, and upstream of the roller pair immediately before being sandwiched by the roller pair. And a tension control means for controlling the tension in the longitudinal direction with respect to the side end portion of the head. The tension control range is at least 3 N / m ² or more and 45 N / m ² or less.

  And the outer peripheral surface of at least one roller of the roller pair is made of rubber or metal having irregularities for suppressing slippage of the side end portion, and the roller pair is formed at the side end portion with a predetermined narrowing pressure. It is preferable to have a pressure control means for holding the pressure, and the pressure control range is at least 0.05 MPa to 0.4 MPa.

  Furthermore, it connects with the conveyance part for conveying the said film, and this conveyance part changes a film conveyance speed so that it may increase in steps in the unit of 5 m / min or more and 30 m / min or more continuously. Sometimes, the tension control means for controlling the tension to decrease stepwise according to the change of the speed, or the pressure control for controlling the pressure to decrease stepwise according to the change of the speed Preferably means are provided.

  Moreover, it has the cutting | disconnection means which cut | disconnects a side end object so that it may become a side edge part piece, and the 2nd air supply path for blowing this side edge part piece, The length of the air supply path to a cutting means The thickness is preferably 20 m or less. And when at least one part of the said 1st or 2nd ventilation path is piping and this piping has a bending part, the direction of the bending is the direction and the width direction of the anti-conveyance of the film in the conveyance part. More preferably, the direction is any direction except the direction along the line.

  In the air blowing device of the present invention, separation means for separating the air that has blown the side end piece from the side end piece, and air separated by the separation means are supplied to the first air sending device. A return pipe for returning to a predetermined position of the path, and the predetermined position of the first air sending path is a pipe in which a long side end is blown and a jacket for allowing the air to flow into the pipe It is preferable that the jacket has an inlet for the air to enter. Moreover, it is preferable that the air blowing device of the present invention includes a static electricity removing unit for controlling a charged voltage value of at least one of the side end portion and the side end piece. And the air blower of this invention shows a big effect, when a film is a cellulose acylate film.

  Furthermore, this invention is comprised including the manufacturing method of the cellulose acylate film characterized by using said blowing method or said blowing device.

  With the ear dust transport method and apparatus of the present invention, it is possible to reliably transport an ear dust of a thin film of 80 μm or less. As a result, a polymer film having a thickness of 80 μm or less can be stably and continuously produced, and productivity can be improved.

  The present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. FIG. 1 is a schematic view of a film manufacturing process embodying the present invention. The solution casting apparatus 10 includes a reserve tank 12 to which the dope 11 is supplied, a pump 15 for liquid feeding, a casting device 16, a tenter device 17, first and second ear-cutting devices 21 and 22, a roller A drying device 23 and a winding device 24 are provided, and first and second air feeding devices 27 and 28 are connected to the solution casting apparatus 10. The casting apparatus 16 includes a casting die 31 and a band 33 as a support that is conveyed while being supported by a backup roller 32. A stripping roller 37 for stripping the film 36 from the band 33 is provided downstream of the band 33. In order to stably introduce the film 36 into the tenter device 17, the number of rollers 38 is increased or decreased as needed, downstream of the peeling roller 37.

  The dope 11 is sent from the reserve tank 12 to the casting die 31 by the liquid feed pump 15. The casting die 31 casts the dope 11 on the band 33. The band 33 is continuously conveyed by a backup roller 32 that is driven to rotate, whereby the dope 11 is continuously cast. The cast dope is peeled off as a film 36 when it has self-supporting properties on the band 33. 1, the film 36 is wound around a peeling roller 37 as shown in FIG. 1 and may be continuously performed by the rotation of the roller 37, or the film 36 may be removed by other peeling means. It may be performed continuously by applying tension from the downstream side of the band 33 in the transport direction. The peeled film 36 is fed to the tenter device 17 while being normally supported by a plurality of rollers 38.

  In the tenter device 17, the film 36 is dried while being regulated in width and stretched. In the tenter device 17, both end portions of the film 36 are held by a pin tenter (not shown), and the film 36 is conveyed as the pin tenter travels according to a tenter track (not shown). A tenter clip or the like may be used in place of the pin tenter. The pin tenter has a plurality of pins to be held by piercing the side end of the film 36. When the pin tenter reaches a predetermined position near the outlet of the tenter device 17, the pin is pulled out of the film 36, and the film 36 Holding is released. When a tenter clip is used, opening and closing of the clip portion is automatically controlled by a controller (not shown), and the film 36 is held and released by this opening and closing. The tenter clip holding the film 36 travels inside the tenter device 17 and is automatically controlled so as to release the holding portion and release the holding of the film 36 when reaching a predetermined holding release point near the exit.

  The film 36 of the tenter device 17 is sent to the first ear-cutting device 21 and cut at both ends. In order to guide the film 36 to the first ear opener 21, a roller 38 may be provided as shown in FIG. 1, but it may not be installed. In addition, other guide means may be used instead of the roller 38. The cut ear dust 36c is sent to the first ear dust air feeding device 27, while the central portion is sent to the roller drying device 23, which is the next process, where it is supported by a plurality of rollers 23a and predetermined. After being sufficiently dried while being transported by the distance, both end portions are further cut by the second ear-cutting device 22 so as to have a predetermined width. The second ear opener 22 has the same structure as the first ear opener 21. The central portion remaining after the side end portion is cut is wound up as a product by the winding device 24, while the cut ear dust is sent to the second ear dust blowing device 28.

  FIG. 2 is an explanatory diagram of the ear-cutting process. In the present embodiment, the first ear-cutting device 21 and the second ear-cutting device 22 are the same, and the ear-cutting method using them is also the same. Therefore, here, the ear-cutting process in the first ear-cutting device 21 (hereinafter referred to as the first ear-cutting step). 41), and the description of the ear-cutting process in the second ear-cutting device 22 (hereinafter referred to as the second ear-cutting process) will be omitted. The first ear-cutting process 41 includes a first ear-cutting device 21 and a knurling device 43 for forming irregularities on the film side end so as to stabilize film transport after the first ear-cutting process. The knurling device 43 is provided with an embossing roller 43a having fine irregularities on the surface, and the film 36 is narrowed by being paired with a roller (not shown) for supporting the film 36 so as to make irregularities at predetermined portions of the film. Is for. In FIG. 2, the embossing roller 43 a has a function of guiding the film 36 to the first ear cutting device 21 instead of the roller 38 in FIG. 1. Further, the first ear cutting device 21 includes a cutting blade 44 composed of an upper round blade and a lower round blade, and the film 36 is cut by the cutting blade 44.

  As shown in FIG. 2, the film 36 sent from the tenter device 17 passes through the knurling device 43 and the first ear-cutting device 21, and the central portion after both end portions are cut off is roller drying in the subsequent step. Sent to the device 23. The knurling device 43 uses the embossing roller 43a to make the inner portion of the film 36 near the ear 36a a knurling portion 36b composed of fine irregularities. In FIG. 2, the knurling portion 36b is shown as a hatched portion. The cutter 44 of the first ear clip device 21 cuts the ear portion 36a as ear dust 36c at a position outside the knurling portion 36b. The film 36 from which the ears 36a have been cut is dried by the roller drying device 23, and is transported in a state where slippage on the rollers 23a of the roller drying device 23 is suppressed by the unevenness of the knurling portions 36b, for example. A predetermined tension in the direction is maintained, and good conveyance is performed. The rollers 38 may not be installed when the film running state to the roller drying device 23 is good, and the number of rollers 38 is increased or decreased depending on the conveying state. As described above, the film 36 is cut in the first ear cutting step 41. In this embodiment, the knurling part 36b is cut and removed in the second ear-cutting process. However, a part of the knurling part 36b may be removed or may not be removed and may be left on the film as a product.

  Further, the processing of the ear dust 36c separated from the film 36 will be described in detail later, but after the first ear-cutting step 41, as shown in FIG. Are sent to the silo 45 for reuse. The first air blowing device 27 has a suction duct 47 provided with a suction port 46 and a rotary cutter 48 connected to the lower part of the suction duct 47, and the ear dust 36 c passes through the first suction port 46. The air is sucked into the air feeding device 27 and is cut into strips by the rotary cutter 48.

  Next, a collection method for reusing the ear dust 36c will be described in detail. FIG. 3 is a schematic view of the first air blowing device 27. The first air blowing device 27 is provided for collecting the ear dust 36c. In addition, although the 2nd air blowing apparatus 28 (refer FIG. 1) is provided downstream of the 2nd ear cutting process, the 1st air blowing apparatus 27 and the 2nd air blowing apparatus 28 are the same, and the ear | edge by these Since the collection method of the waste 36c is the same, the ear dust collection step (hereinafter referred to as the first recovery step) in the first air blowing device 27 will be described here, and the ear dust in the second air blowing device 28 is described. Description of the recovery process (hereinafter referred to as the second recovery process) is omitted.

  As shown in FIG. 3, the first air blowing device 27 includes a suction duct 47 having a suction port 46, a rotary cutter 48, an ionizer 50, a silencer 51, a cut blower 52, a separator 53, and a crusher 56. These pipes 59 to 68 are connected to each other to send the ear dust 36c by wind flowing in a predetermined direction. Reference numerals 71, 72, and 73 denote shutters provided in the pipes 65, 66, and 67. These shutters 71 to 73 adjust the wind speed in the pipes by adjusting the opening. Reference numeral 76 denotes a filter, and 77 denotes a shutter. Further, since the ear dust 36c is cut from both ends of the film 36, a pair of the suction duct 47, the rotary cutter 48, the pipes 59, 60, 61, 62, and the silencer 51 are provided.

  A rotary cutter 48 is connected to the lower part of the suction duct 47 for taking the ear dust 36c into the first air blowing device 27. The rotary cutter 48 can continuously cut the long-shaped ear dust 36c that is sent into, for example, a strip-shaped piece. Various known cutting blades can be used in place of the rotary cutter 48 as long as the long ear dust 36c is cut short and continuously.

  The ionizer 50 downstream of the rotary cutter 48 is provided to control the charged voltage value of the ear dust 36c cut short, and various publicly known static electricity removing means that are commercially available can be used. Examples of the static electricity removing means include various types such as a voltage application type static eliminator, a self-discharge type static eliminator, and a piezoelectric transformer type static eliminator. Among them, the self-discharge type static eliminator is in contact with a target object. Therefore, it is unsuitable for inhibiting air feeding in the present invention. Therefore, as the ionizer 50 in the present invention, a type that supplies ion wind to the object to be neutralized is preferable in that it does not inhibit the air feeding. For example, a voltage application type static eliminator, a piezoelectric transformer type static eliminator, etc. A forced application type static eliminator is preferred. In some cases, the rotary cutter 48 is not installed. In this case, the ear dust 36c remains long and is sent to the cut blower downstream. In addition, when the ear dust 36c is blown to the cut blower while maintaining the long shape, the ionizer 50 may be used to neutralize the long ear dust 36c. Note that the number of ionizers 50 may be increased as necessary, and a plurality of ionizers 50 may be appropriately installed in the air feeding line regardless of the upstream side or the downstream side of the rotary cutter 48.

  As the silencer 51 for reducing vibration, sound, etc. in the process from the suction duct 47 to the rotary cutter 48, in the present embodiment, a silencer 51 that can absorb sound is used, but is not limited thereto. Various known sound absorbing means can be used.

  The cut blower 52 further cuts the strip-shaped pieces cut by the rotary cutter 48 into side end pieces (hereinafter simply referred to as small pieces), and sends them to the separator 53. The cut blower 52 has air blowing means (not shown) and generates an air flow inside the pipes 59 to 68. When the rotary cutter 48 is not installed, the cut blower 52 can cut the long ear dust 36c into side end pieces. And as the separator 53 for isolate | separating a small piece and air, the cyclone separator using a centrifugal force is used in this embodiment. The cyclone separator centrifuges a solid from a mixed phase flow of a solid and a gas, that is, a solid-containing air flow, and is suitable as the separator 53 because of its simple structure and easy maintenance and inspection. Other known various separators may be used as long as they can be separated from each other. Further, a crusher 56 for making the small pieces finer is provided downstream of the separator 53. In the present embodiment, a commercially available product is used as the crusher 56, and the crusher 56 is connected to a silo 45 stored in a state where small pieces are finely crushed. A sampling pipe 78 for sampling a part of the ear dust 36c is provided so as to branch from the pipes 59 and 60, respectively.

  Using the first air blowing device 27, the ear dust 36c is gradually made finer and reused as described below. Both end portions separated from the film 36 by the first ear-cutting device 21 (see FIG. 2) are respectively formed into long ear dust 36c from the suction port 46 of the separate suction duct 47 into the first air feeding device 27. Sucked. As will be described in detail later, the ear dust 36 c is sucked into the suction duct 47 by the conveying force of the pair of feed rollers provided immediately before the suction duct 47 and the suction force by the airflow. When the ear dust 36c reaches the rotary cutter 48 from the suction duct 47, it is cut into strips.

  The strip-shaped piece enters the pipes 59 and 60 from the rotary cutter 48 by the suction force of the air currents of the pipes 59 and 60, passes through the silencer 51 along the airflow, and further flows into the airflow of the pipes 61 and 62 and is guided to the cut blower 52. It is burned. The strip-shaped piece is further cut into small pieces by the cut blower 52 and then sent to the separator 53 by the air current inside the pipe 63 to be separated from the air.

  The small pieces are further finely crushed by the crusher 56 and then sent to the silo 45 by the pipe 68 to be stored for reuse. On the other hand, most of the air separated from the small pieces by the separator 53 passes through the pipes 64, 65, and 66, is again led to the pipes 59 and 60 from the suction duct 46, and is used for air blowing the ear dust 12d. Or although illustration is abbreviate | omitted, most of this air may be sent to both the downstream of the rotary cutter 48, and the suction duct 47 through piping 64,65,66. A part of the air separated from the small pieces by the separator 53 is sent to the pipe 68 via the pipe 67, and this air is used for blowing the small pieces to the silo 45.

  Further, the strip-like pieces of the rotary cutter 48 are appropriately sampled from the pipe 78, and the sample strip-like pieces are used for various inspections and evaluations of the ear dust 36c. The pipe 78 is provided with a shutter (not shown), which is appropriately opened and closed. When sampling is performed, this is opened, and a part of the airflow in the pipe 59 is passed through the pipe 78.

  As described above, most of the airflow is circulated in the closed system except for the airflow to the silo 45 and the airflow at the time of sampling. In order to prevent the airflow in the circulation system from decelerating due to the exhaust airflow described above, the opening degree of the shutter 72 is increased to take in outside air, and the air blowing force from the cut blower 52 is increased. When the airflow is larger than the predetermined state, the opening degree of the shutter 71 is reduced, the shutter 72 is closed, or the opening degree is reduced. Thus, the airflow in the circulation system is controlled by the operating conditions of the cut blower 52 and the opening adjustments of the shutters 71 and 72.

  Next, with reference to FIG. 4, the method for blowing the ear dust 36 a according to the present invention will be described in more detail. FIG. 4 is a perspective view of a main part including a partial cross section of the first air blowing device 27. As shown in FIG. 4, the first air blowing device 27 has a feed roller pair 81 in the vicinity of the suction port 46 of the suction duct 47 and a roller 82 provided in the upstream part of the feed roller pair 81. ing. The feed roller pair 81 includes a driving roller 86 whose rotational speed is controlled by a motor 85 having a controller (not shown), and a pressing roller 87 that holds the driving roller 86 and the ear dust 36c. The pressing roller 87 has a metal surface and fine irregularities, and the pressing force applied to the driving roller 86 is adjusted by a spring 87a as an elastic body and the irregularities, and the driving roller 86 removes the ear dust 36c. The rotational speed is controlled so as to feed at a predetermined speed. Thereby, the ear dust 36c is conveyed more stably. The pressing roller 87 is provided with a shift portion (not shown) and is displaced between the retracted position and the pressing position. The pressing roller 87 is set to the retracted position when the tip of the ear dust 36c passes, and is set to the pressing position after passing the tip.

  A shift portion 89 is provided on the roller 82 upstream of the feed roller pair 81, and the roller is displaced by the shift portion 89. By this displacement, the wrap angle (winding center angle) of the ear dust 36 c in the driving roller 86 and the tension in the conveying direction of the ear dust 36 c until reaching the feed roller pair 81 are adjusted. For example, a part of the suction duct 47 may have a larger diameter, and the feed roller pair 81 may be provided in the suction duct 47 having a larger diameter. In the present invention, the relative position between the suction duct 47 and the feed roller pair 81 may be provided. It does not depend on.

  The suction duct 47 has a double structure including a duct main body 91 and a jacket 92, and the duct main body 91 is connected to the rotary cutter 48. The jacket 92 is provided with a vent 92 a for allowing air that has been separated from the small pieces by the separator 53 and sent by the pipe 65 to enter. The rotary cutter 48 includes a rotary blade 48a and a fixed blade 48b. When the rotary blade 48a rotates, the ear dust 36c is cut into a strip shape between the fixed blades 48b.

  The rotary cutter 48 is connected to the silencer 51 by pipes 59 and 60. An ionizer 50 is provided in the piping downstream of the rotary cutter 48. In addition, another pipe that communicates with a pipe downstream of the rotary cutter 48 may be provided, and an ionizer may be provided in the newly provided pipe. Here, as shown in FIG. 4, the transport direction of the film 36 from which the ear dust 36 c has been cut is defined as the X direction, the direction orthogonal to the X direction is defined as the Y direction, and the direction orthogonal to the XY plane is defined as Z. For the X direction, the transport direction is +, and the reverse transport direction is-. In the present embodiment, the pipes 59 to 63 extending from the suction port 46 to the separator 53 are provided so that the airflow is directed downward or the film is conveyed. That is, the pipes 59 to 63 are provided so that the direction of the airflow does not become the -X direction or the Y direction.

The air blowing of the ear dust 36c by the first air blowing device 27 will be described in more detail. The ear dust 36 c is conveyed to the suction duct 47 by the feed roller pair 81. In the suction duct 47, the ear dust 36 c passes through the suction duct 47 and passes through the rotary cutter due to the conveying force of the feed roller pair 81, the airflow in the pipe 59, and the airflow from the vent 92 a entering the suction duct 47 from the suction port 46. 48. At this time, the wrap angle of the ear dust 36 c in the drive roller 86 is adjusted, and the tension in the conveying direction of the ear dust 36 c when introduced into the feed roller pair 81 is controlled by the displacement of the roller 82. At this time, when the value of the tension of the ear dust 36c is T (unit: N / m ² ), 3 ≦ T ≦ 45, more preferably 5 ≦ T ≦ 40. By setting the tension T of the ear dust 36c within this range, the ear dust 36c can be transported satisfactorily. If the tension T of the ear dust 36c is less than 3 N / m ^2, a conveyance failure or the like occurs such that the duct body 91 is clogged downstream of the feed roller pair 81. 36c may break.

  In the present embodiment, the tension T of the ear dust 36c when introduced into the feed roller pair 81 may be measured using a commercially available on-line tension measuring device, or depending on circumstances, in the feed roller pair 81. The relationship between the torque value and the tension may be obtained in advance, and the torque value may be read as appropriate. However, the present invention is not limited to the method for measuring the tension T as described above, and various known measuring methods can be applied.

  Further, the pinch pressure of the ear dust 36c by the feed roller pair 81 is controlled to be 0.05 MPa or more and 0.4 MPa or less by adjusting the position of the pressing roller 87 and the spring 87a, thereby the suction duct of the ear dust 36c. The conveyance at 47 is further stabilized. If the pinching pressure is smaller than 0.05 MPa or larger than 0.4 MPa, the ear dust 36c may meander and clog the inside of the suction duct 47.

  The clamping pressure in this embodiment was measured by providing a tension measuring device on the side opposite to the pressing direction of the pressing roller 87 and detecting the tension value by this tension measuring device. As the tension measuring device, not only a spring but also a commercially available product such as a push-pull gauge can be used. In addition, a cylinder gauge is provided on the pressing roller 87, and measurement may be performed using the cylinder gauge. However, the present invention is not limited to the method for measuring the clamping pressure T as described above, and various known measuring methods can be applied.

  Even if the film 36 having a thickness of 20 μm or more and 500 μm or less is produced at a conveyance condition as described above, for example, at a rate of 10 m / min or more and 150 m / min or less, the ear dust 36c is produced depending on the production speed. The air can be sent in a suitable state. In addition, when the film 36 is speeded up in steps of 5 m / min to 30 m / min and the film is manufactured under the same other conditions, the tension T or the feed roller pair 81 is used. If the pinch pressure is reduced stepwise according to each speed increase, the ear dust 36c can be stably blown as before the speed increase.

  As the surface material of the pressing roller 87, a rubber-based material or a metal can be preferably used. However, it is particularly preferable to provide unevenness such as embossing on the outer peripheral surface of the metal surface in terms of suppressing wear due to the ear dust 36c. Thereby, the slip of the ear dust 36c on the pressing roller 87 can be suppressed, and the tension T and the pressing pressure can be maintained at predetermined values. In the present invention, as described above, the suction duct has a double structure, and the airflow from the vent 92a is introduced from the suction port 46, whereby the ear dust 36b is sucked into the suction duct 47, the suction duct, The conveying force of the ear dust 36c and the strip-shaped piece 36d inside the rotary cutter 48 is increased to prevent clogging of the suction duct 47, the rotary cutter 48, the downstream pipe and the like by the ear dust 36c and the strip-shaped piece 36d. The effect is improved.

  The ear dust 36c is cut by the rotary cutter 48, and is sent to the silencer 51, the pipes 61 and 62, and the cut blade 52 as a strip-shaped piece 36d. By the way, the ear dust 36c and the strip-shaped piece 36d may be charged while reaching the rotary cutter 48, and the air feeding may not be performed satisfactorily due to this charging. In particular, the strip-shaped piece 36d after being cut by the rotary cutter 48 is often charged. Therefore, in the present invention, the strip-like piece 36d is neutralized by the ionizer 50, and the charged voltage value is controlled to be -5 kV or more and 5 kV or less. Thereby, sticking in the piping downstream of the rotary cutter 48 can be prevented, and air feeding can be further stabilized. Further, when the ionizer 50 is provided in the upstream portion of the rotary cutter 48, sticking to the feed roller pair 81 and the like can be prevented, which is effective. The use of the ionizer 50 is particularly effective when the thickness of the film 36 to be manufactured is approximately 80 μm or less. For example, according to the study by the present inventors, when the thickness of the film 36 to be manufactured is 40 μm to 80 μm, the charged voltage value when the ionizer 50 is not used is 5.5 to 10 kV, and the air sending state is deteriorated. On the other hand, when the ionizer 50 is used, the charged voltage value is 0.5 to 2.5 kV and the air feeding is stably performed.

  Then, the strip-shaped piece 36 d reaches the separator 53 by the air flow of the pipe 63. As shown in FIG. 4, the film 36 from which the ear dust 36 c has been cut is transported in the + X direction. In the present invention, while the ear dust 36 c or the strip-shaped piece 36 d is being transported (hereinafter referred to as the ear dust being transported). ) Flows in the conveying direction of the film 36 or in the vertical direction. According to the study by the present inventors, the direction of the airflow during the ear dust conveyance is changed from the vertical direction or the conveyance direction of the film 36 so as to run backward to the conveyance of the film 36, or the direction along the width direction. If the direction is changed, the ear dust 36c is clogged at the direction change point, but the ear dust 36c or the strip-shaped piece can be obtained by installing the pipe so that the direction of the airflow during the ear dust conveyance is the above-mentioned direction. 36d can be transported satisfactorily without clogging the transport system. When the airflow during the ear dust transport has to change from the vertical direction or the transport direction of the film 36 to the direction opposite to the transport of the film 36 or the direction along the width direction. If the curvature radius of the pipe is increased or the bent portion is formed at a position as downstream as possible in the pipe, clogging of the ear dust 36c can be prevented or the influence of the clogging can be reduced.

  In the present invention, most of the airflow is circulated and used as described above. Thereby, it can suppress that the substance which volatilizes from the ear dust 36c or the strip-shaped piece 36d is discharge | released outside. Therefore, it is particularly effective when an organic solvent is used for film production or the film contains an additive that may volatilize as in the solution casting method.

  Furthermore, in this invention, the conveyance distance of the ear dust 36c and the strip-shaped piece 36d from the exit of the 1st ear opener 21 to the entrance of the cut blower 52 is 2 m or more and 20 m or less. However, this conveyance distance is not a linear distance, but means the length of the conveyance path through which the ear dust 36d and the strip-shaped piece 36d are actually conveyed. However, it is impossible to design the transport distance to be shorter than 2 m from the standpoint of the device design, and the vibration of the cut blower 52 may be easily transmitted to various parts of the device or may affect the tension control. On the other hand, when the length is larger than 20 m, the power for generating the airflow at a predetermined wind speed becomes too large, and there is a high possibility that the ear dust 36c and the strip-shaped piece 36d are clogged in the transport system. The transport distance is more preferably 2 m or more and 15 m or less.

  The present invention is particularly effective when manufacturing various very thin films having a thickness of 20 μm to 80 μm. Such a very thin film has a very thin ear portion that is cut in the manufacturing process, and in general, as the conveyance speed is increased, for example, the probability of occurrence of conveyance failure due to generated static electricity increases, but according to the present invention, It can be aired well. The application range of the conveyance speed, that is, the film production speed is 10 m / min or more and 150 m / min. When the conveying speed is less than 10 m / min, the ear cutting is not performed. On the other hand, when the speed is higher than 150 m / min, it is difficult to control the tension of the ears leading to the pair of feed rollers, the suction force control using the suction duct, and the like, which may result in poor conveyance. In addition, the above effect can be applied especially easily when manufacturing a film having a width of 10 mm to 120 mm. In the above embodiment, the ear dust is formed into a strip-like piece by a rotary cutter and is sent by air. However, the present invention is effective even when air is sent in a long shape without using a rotary cutter or the like. And this invention can be applied not only as conveyance of the ear | edge part cut | disconnected from the film but also as a method of airing other thin long objects.

  Moreover, in this embodiment, although the film to manufacture is made into the cellulose triacetate film, it is not limited to this. Further, the application is not limited to the polymer film produced by the solution casting method as in the present embodiment, and for example, the effect can be obtained even with a polymer film produced by a melt extrusion method or the like. . However, in the case of film production by the solution casting method, a particularly great effect is obtained.

  Examples of the polymer of the film that can obtain the most effects as described above according to the present invention include various cellulose acylates including cellulose triacetate in the present embodiment.

[Experiment 1]
Next, examples of the present invention will be described. 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 mass fine particles (silicon dioxide (particle size 15 nm), Mohs hardness of about 7) 0.05 parts by mass dye (dye example 4)) 0.0005 parts by mass

[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, and 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 was prepared using a dope preparation device. In a 4000 L stainless steel dissolution tank 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 powder (flaked powder) was gradually added from the hopper of the dissolution tank. The TAC powder was put into a dissolution tank and dispersed under a predetermined stirring condition for 30 minutes by a dissolver type eccentric stirrer 21 equipped with an anchor blade 19 on a rotating shaft. The temperature at the start of dispersion was 25 ° C., and the final temperature reached 48 ° C. Further, an additive solution prepared in advance was adjusted from the additive tank to the dissolution tank by adjusting the amount of liquid fed with a valve so that the total amount was 2000 kg. After the dispersion of the additive solution was completed, high-speed stirring was stopped, and then the peripheral speed of the anchor blade 19 was set to a predetermined value and further stirred for 100 minutes to swell the TAC flakes to obtain a swelling liquid. The tank was pressurized to 0.12 MPa with nitrogen gas until the end of swelling. The inside of the dissolution tank at this time was kept in a state where there was 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 was fed from the dissolution tank to the jacketed pipe using a pump. The swelling liquid was heated to 50 ° C. with a jacketed pipe, 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, and the dope (hereinafter referred to as pre-concentration dope) was obtained by passing through a filtration device equipped with a filter medium having a nominal pore diameter of 8 μm. At this time, the primary pressure in the filtration device was 1.5 MPa, and the secondary pressure was 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 apparatus at 80 ° C. and normal pressure, and the evaporated solvent is condensed in a condenser. And recovered. The solid concentration of the dope after flashing was 21.8% by mass. The condensed solvent was recovered by a recovery device to be reused as a dope preparation solvent, regenerated by a regeneration device, and then sent to a solvent tank. Distillation and dehydration are performed in the recovery device and the regeneration device. The flash tank of the flash device 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 (sec ⁻¹ ).

  Next, bubbles were removed by irradiating the dope with weak ultrasonic waves. Thereafter, the filter was passed through the pump while being pressurized to 1.5 MPa using a pump. In the filtration apparatus, 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 diameter 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 11 was fed into a 2000 L stainless steel stock tank and stored therein. The stock tank has a stirrer having an anchor blade on the central axis, and the inside is constantly stirred by this stirrer. In addition, no problem such as corrosion occurred at all in the wetted part of the dope from the dope before concentration to the preparation of the dope 11.

  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 / immediate addition / casting / bead depressurization A film was produced using the solution casting apparatus 10 shown in FIG. The dope 11 in the reserve tank 12 was sent to the filtration device by the high precision gear pump 15. This pump 15 has a function of increasing the pressure on the primary side of the pump 15 and sends the liquid by performing feedback control on the upstream side of the pump 15 with an inverter motor so that the pressure on the primary side becomes 0.8 MPa. . The pump 15 has a volume 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 11 that passed through the filtration device was fed to the casting die 31.

  The casting die 31 was cast by adjusting the flow rate of the dope 11 at the discharge port of the die 31 so that the width of the casting die 31 was 1.8 m and the thickness of the dried film 36 was 80 μm. The casting width of the dope 11 from the discharge port of the die 31 was 1700 mm. In order to adjust the temperature of the dope 11 to 36 ° C., a jacket (not shown) is provided on the casting die 31 and the inlet temperature of the heat transfer medium supplied into the jacket is set to 36 ° C.

  The casting die 31 and the piping were all kept at 36 ° C. during operation. The casting die 31 is a coat hanger type die. And as this die | dye 31, the thickness adjustment bolt was provided in 20 mm pitch, and what equipped the automatic thickness adjustment mechanism by a heat bolt was used. This heat bolt can also set a profile according to the amount of liquid delivered by the pump 15 by a preset program, and is fed back by an adjustment program based on the profile of an infrared thickness meter (not shown) installed in the solution casting apparatus 10. The thing which has the performance which can also be controlled was used. In the film excluding the casting side end portion of 20 mm, the difference in thickness between any two points separated by 50 mm was 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 for decompressing this portion was installed on the primary side of the casting die 31. The degree of decompression of the decompression chamber is adjusted so that a pressure difference of 1 Pa to 5000 Pa is generated before and after the casting bead, and this adjustment is made according to the casting 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 was provided with a mechanism that can be set to a temperature higher than the condensation temperature of the gas around the casting part. Labyrinth packings (not shown) were provided on the front and back sides of the beads at the die discharge port, and openings were provided at both ends of the die discharge port. Further, the die 31 is provided 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 31 is a material precipitation hardening type stainless steel having a coefficient of thermal expansion 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 31 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. The corner portion of the liquid contact portion at the tip of the lip of the die 31 is processed so that R is 50 μm or less over the entire width of the slit. The shear rate inside the die was in the range of 1 (1 / sec) to 5000 (1 / sec). Further, a WC (tungsten carbide) coating was performed on the lip end of the casting die 31 by a thermal spraying method to provide a cured film.

  Furthermore, in order to prevent the dope 11 flowing out from being locally dried and solidified at the discharge port of the casting die 31, the mixed solvent A for solubilizing the dope 11 is provided on both side ends of the casting bead. Each 0.5 ml / min was supplied to the interface with the discharge port. The pulsation rate of the pump supplying the mixed solvent A was 5% or less. In addition, the pressure on the back side of the bead was reduced by 150 Pa from the front side by the decompression chamber. In addition, a jacket (not shown) was attached in order to keep the internal temperature of the decompression chamber constant at a predetermined temperature. A heat transfer medium adjusted to 35 ° C. was supplied into the jacket. The edge suction device can adjust the edge suction air volume so as to be in the range of 1 L / min to 100 L / min, and in the present embodiment, this is in the range of 30 L / min to 40 L / min. Adjusted appropriately.

(1-6) Metal support As the support, a stainless steel endless band having a width of 2.1 m and a length of 70 m was used as the casting band 27. The casting band 27 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 27 was 0.5% or less. The casting band 27 was conveyed by two backup rollers 32. At this time, the relative speed difference between the casting band 27 and the backup roller 32 is 0.01 m / min or less so that the tension in the conveying direction of the casting band 27 is 1.5 × 10 ⁵ N / m ^2. Adjusted as follows. The speed fluctuation of the casting band 27 was 0.5% or less. Further, both end positions of the casting band 27 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 fluctuation in the vertical direction between the die lip tip and the casting band 27 immediately below the casting die 31 was set to 200 μm or less. The casting band 27 is installed in a casting chamber (not shown) having wind pressure fluctuation suppressing means (not shown). The dope 11 was cast from the casting die 31 on the casting band 27.

As the backup roller 32, a roller capable of feeding a heat transfer medium therein was used so that the temperature of the casting band 27 could be adjusted. A 5 ° C. heat transfer medium was passed through the backup roller 32 on the casting die 31 side, and a 40 ° C. heat transfer medium was passed through the other backup roller 36 for drying. The surface temperature of the central part of the casting band 27 immediately before casting was 15 ° C., and the temperature difference between both side ends was 6 ° C. or less. The casting band 27 preferably has no surface defects, has no pinholes of 30 μm or more, has 1 to 10 μm to 30 μm pinholes / m ² or less, and has 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 was kept at 35 ° C. using temperature control equipment. The casting film formed from the dope 11 cast on the casting band 27 was first fed with drying air flowing parallel to the casting film, and dried. The overall heat transfer coefficient from the dry air to the cast film 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 27 and 140 ° C. on the downstream side. The lower part of the casting band 27 was blown from a blower (not shown) 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 27 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, a condenser (condenser) was provided, and its outlet temperature was set to -10 ° C.

For 5 seconds after casting, the dry air from the wind shield device was prevented from directly hitting the dope 11 and the casting film, and the static pressure fluctuation in the immediate vicinity of the casting die 31 was suppressed to ± 1 Pa or less. When the solvent ratio in the cast film reached 50% by mass on a dry basis, the film was peeled off from the casting band 27 while being supported by a peeling roller. 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 27 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 rate on the casting band 27 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 film 36 was conveyed through a roller and sent to the tenter device 17. At the time of this conveyance, 40 degreeC dry air was sent with respect to the film 36 from the air blower (not shown). It should be noted that a predetermined value of tension is applied to the wet film 66 during conveyance by the roller at the crossover portion.

(1-8) Tenter Transport / Drying / Ear Cutting The film 36 sent to the tenter device 17 is transported in the drying zone of the tenter device 17 while being fixed at both ends with clips, and is dried by drying air during this time. The clip was cooled by supplying a heat transfer medium at 20 ° C. The clip in the tenter device 17 was conveyed by a chain, and the speed fluctuation of the sprocket was 0.5% or less. Further, the interior of the tenter device 17 was divided into three zones, and the drying air temperature of each zone was set to 90 ° C., 100 ° C., and 110 ° C. from the upstream side. The gas composition of the drying air was set to a saturated gas concentration at −10 ° C. The average drying speed in the tenter device 17 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 36 at the outlet of the tenter device 17 was 7% by mass. In the tenter device 17, the film 36 was transported and stretched in the width direction. In addition, when the width | variety of this film 36 before extending | stretching was 100%, it extended | stretched so that the width | variety after extending | stretching might be 103%. The stretching ratio (tenter drive draw) from the peeling roller to the entrance of the tenter device 17 was 102%. The stretching ratio in the tenter device 17 is an arbitrary difference in which the difference between the substantial stretching ratios at any two points at positions 10 mm or more away from the biting start position by the clip is 10 (unit:%) or less and 20 mm apart. The difference between the stretching ratios at the two points was 5 (%) or less. 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 was 90%. The solvent evaporated in the tenter apparatus 17 was condensed and liquefied at a temperature of −10 ° C. and recovered. A condenser (condenser) was provided for condensation recovery, and the outlet temperature was set to -8 ° C. The condensed solvent was reused after adjusting the water content to 0.5% by mass or less.

  Then, the ear cutting of the film 36 was performed by the first ear cutting device 21 within 30 seconds from the outlet of the tenter device 17. Note that this ear-cutting will be described in detail later.

(1-9) Post-drying / static elimination The film 36 was dried at high temperature by the roller dryer 23. The roller drying device 23 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 conveyance tension of the film 36 by the roller 23a was controlled to a predetermined value, and the film 36 was dried for about 10 minutes until the residual solvent amount finally reached 0.3% by mass. The wrap angle (film winding center angle) in the roller 23a was 90 ° and 180 °. The material of the roller 23a was made of aluminum or carbon steel, and the surface was hard chrome plated. As the surface shape of the roller 23a, a flat one and a mat formed by blasting were used. All film position fluctuations due to the rotation of the roller 23a were 50 μm or less. The roller deflection under a predetermined tension condition was selected to be 0.5 mm or less.

  The solvent gas contained in the drying wind was removed by adsorption using an adsorption / recovery device (not shown). 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 36 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 drying device 23 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 36 was conveyed to a second humidity control chamber (not shown) for suppressing the curling of the film 36. In the second humidity control chamber, air of 90 ° C. and humidity 70% was directly applied to the film 36.

(1-10) Knurling and Winding Conditions The film 36 after humidity control was subjected to ear cutting by the second ear cutting device 22 after being cooled to 30 ° C. or lower in the cooling chamber. A forced charge removal device (charge removal bar) was installed so that the charged voltage of the film 36 during conveyance was always in the range of -3 kV to +3 kV. Further, knurling was applied to both ends of the film 36 with a knurling roller. The knurling is imparted by embossing from one side of the film 36, the width for imparting the knurling is 10 mm, and the knurling is pushed by a knurling roller so that the height of the irregularities is 12 μm higher than the average thickness of the film 36. The pressure was set.

  Then, the film 36 was conveyed to the winding device 24. The winding device 24 is maintained at an internal temperature of 28 ° C. and a humidity of 70%. Further, an ion wind neutralization device (not shown) was also installed in the winding device 24 so that the charged voltage of the film 36 was −1.5 kV to +1.5 kV. The product width of the film (thickness 80 μm) 36 thus obtained is 1475 mm. The diameter of the winding roller of the winding device 24 is 169 mm. The tensions at the start and end of winding were controlled so as to have predetermined values. The total length of the wound film 36 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. Further, the pressing pressure of the press roller against the winding shaft was set to a predetermined value. The temperature of the film 36 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 36 was formed, no peeling residue of the cast film formed from the dope 11 was found on the cast band 27.

(1-11) Evaluation and Results Evaluation methods for the samples obtained in the examples are shown below.

(1) Stability of solution The concentrated dope 11 was collected, observed while standing still at 30 ° C., and evaluated in the following four stages of A, B, C, and D.
A: Transparency and liquid uniformity are exhibited even over 20 days.
B: Transparency and liquid uniformity are maintained until lapse of 10 days, but a little white turbidity is observed in 20 days.
C: Transparency and liquid uniformity are observed at the end of liquid preparation, but after one day, it gels and becomes a non-uniform liquid.
D: The liquid is in an opaque and non-uniform liquid state with no swelling / dissolution.

(2) Film surface condition The film 36 was observed visually and the surface condition was evaluated as follows.
A: The film surface is smooth.
B: Although the film surface is smooth, a little foreign material is seen.
C: Weak irregularities are seen on the film surface, and the presence of foreign matter is clearly observed.
D: Unevenness is seen on the film surface, and many foreign matters are seen.

(3) Moisture and heat resistance of the film 1 g from the film 36 was cut as a sample, folded and placed in a 15 ml glass bottle, conditioned at 90 ° C. and 100% RH, and sealed. This was kept at 90 ° C. and removed after 10 days. The state of the film 36 was visually confirmed, and the following determination was made.
A: No particular abnormality is observed B: A slight decomposition odor is observed C: A considerable decomposition odor is recognized D: A change in shape due to decomposition odor and decomposition is observed

  The stability of the dope 11 was A. Further, the obtained film 36 had a film surface shape of A, and was 16 g in the film tear test, the folding resistance test of the film was 71 times, and the moisture and heat resistance was A, all being excellent. The amount of residual acetic acid is less than 0.01% by mass, Ca is less than 0.05% by mass, Mg is less than 0.01% by mass, and the thickness of the cellulose triacetate film is 80 μm ± It was 1.5 μm. This thickness evaluation is performed for each of the front end portion, the middle portion, and the rear end portion in the length direction at both ends and the center portion in the width direction, and the data has an error of 0.2% or less. Was confirmed in advance. In addition, the vertical and horizontal average heat shrinkage (80 ° C., 90% RH, 48 hours) of the film 36 was −0.1%, and it was confirmed that the film 36 that hardly caused heat shrinkage was obtained. Moreover, the residual solvent amount of the film 36 at the exit of the tenter device 17 was 7% by mass, and the solvent gas concentration (LEL value) inside the silo 45 at that time was good at less than 25%.

  The obtained film 36 has a haze of 0.3%, a transparency (transparency) of 92.4%, a slope width of 19.6 nm, a wavelength limit of 392.7 nm, an absorption edge of the absorption wavelength of 374.1 nm, Absorption at 380 nm is 2.0%, in-plane retardation Re is 1.2 nm, thickness direction retardation Rth is 48 nm, molecular orientation axis is 1.4 °, elastic modulus is longitudinal direction 3.54 GPa, width direction 3 .45 GPa, Tensile strength is 142 MPa in the longitudinal direction, 141 MPa in the width direction, Elongation rate is 43% in the longitudinal direction, 49% in the width direction, Kisimi value (static friction coefficient) is 0.65, Kisimi value (dynamic friction coefficient) is The alkaline hydrolyzability was 0.51, the curl value was −0.4 at 25% RH, and 1.7 when wet. The moisture content is 1.4% by mass, the residual solvent amount is 0.3% by mass, and the thermal shrinkage is −0.09% in the longitudinal direction and −0.08% in the width direction. there were. The foreign matter had a lint of less than 5 pieces / m. The bright spots were 0.02 mm to 0.05 mm less than 10/3 m, 0.05 to 0.1 mm less than 5/3 m, and 0.1 mm or more were zero. These had excellent properties for optical applications. Moreover, adhesion after application was not observed (◯), and the moisture permeability was good (◯).

  A dimethyl acetate film having a thickness of 80 μm was produced and evaluated in the same manner as described above, replacing TAC with dimethyl acetate. The evaluation result was the same as TAC.

And the cutting of the side edge part of the film 36 by the edge-cutting device 21 as shown in FIG. 2 is demonstrated. In addition, the both-sides edge part of the film was aired using the 1st air sending apparatus 27 as shown in FIG. 3, and was collect | recovered. The pipes 59 to 68 and 78 had a diameter of 150A, and the air volume was as follows. The air volume at the suction port 46 is 5 m ³ / min, the air volume at the pipes 59 to 62 is 28 m ³ / min, the air volume discharged from the cut blower 23 is 56 m ³ / min, and the air volume at the pipe 64 exiting the separator 53 is 46 m ³ / min. The air volume in the pipe 68 from the crusher 56 to the silo 45 was set to 10 m ³ / min.

The width of the side end portion to be cut was 20 mm, and the pressing roller 87 was a metal roller that was embossed. The embossed portion has rectangular unevenness as shown in FIG. 5, and the pitch d1 is 1 mm and the unevenness depth is 2 mm. Table 1 shows the tension (unit: N / m ² ) in the conveying direction of the ear dust 36 c between the roller 82 and the feed roller pair 81 and the pinching pressure (unit: MPa) of the ear dust 36 c by the feed roller pair 81. These were carried out as Experiments 1-1 to 1-8. In Table 1, the TAC film is film A and the dimethyl acetate film is film B.

In Experiment 1, the ear dust 36c was cut in Experiments 1-1, 1-3, 1-5, and 1-7 with a tension of 50 N / m ² , but Experiment 1-2 with a tension of 15 N / m ² was performed. , 1-4, 1-6, and 1-8, the ear dust 36c was conveyed well. Further, in Experiments 1-3, 1-4, 1-7, and 1-8 with a sandwiching pressure of 0.5 MPa, the ear dust 36c was meandered and conveyed, but Experiment 1 with a sandwiching pressure of 0.1 MPa was performed. Out of 1,1-2,1-5 and 1-6, Experiments 1-2 and 1-6 without cutting were good without meandering. Accordingly, it can be seen that it is effective for conveying the ear dust 36c that the tension is 45 N / m ² or less and the pinching pressure is 0.4 MPa or less.

[Experiment 2]
The width of the ear dust 36c was 100 mm. Other conditions were the same as those in Experiment 1 and were set as Experiments 2-1 to 2-8. The results are shown in Table 2. In Table 2, the TAC film is film A and the dimethyl acetate film is film B.

In this experiment 2, the ear dust 36c was cut in the experiments 2-1, 2-3, 2-5, and 2-7 in which the tension was 50 N / m ² , but the experiment 2-2 in which the tension was 15 N / m ^2. , 2-4, 2-6, and 2-8, the ear dust 36c was transported well. Further, in Experiments 2-3, 2-4, 2-7, and 2-8 in which the pinching pressure was 0.5 MPa, the ear dust 36c was meandered and conveyed, but in Experiment 2 in which the pinching pressure was 0.1 MPa. Among Experiments 1 and 2, 2-5, and 2-6, in Experiments 2-2 and 2-6 that were not cut, they were good without meandering. Accordingly, it can be seen that it is effective for conveying the ear dust 36c that the tension is 45 N / m ² or less and the pinching pressure is 0.4 MPa or less.

[Experiment 3]
The surface state of the pressing roller 87, the presence or absence of embossing, and the uneven shape of the embossing were changed, and the conveyance state of the ear dust 36c was visually observed. As for the results, the conveyance result in Experiment 1-1 is shown as Experiment 3-1, and other conditions are shown in Table 3 as Experiments 3-2 to 3-4. In Experiment 3-2, instead of the pressing roller 87 in Experiment 1 and Experiment 2, the embossed unevenness is a dimple-shaped unevenness 97a as shown in FIG. 6, and the distance d2 between the bottoms of the recessed portions is 0. A metal roller 97 having a thickness of 0.7 mm and an unevenness depth of 0.02 mm was used as a pressing roller. Experiment 3-3 is a flat roller not embossed and made of metal. Moreover, in Experiment 3-4, it is a flat roller which has not been embossed, and the surface is made of a rubber material. In Table 3, when the ear dust 36c does not meander in the predetermined time in the vicinity of the pair of feed rollers, it is marked as ◯. When the start is not meandered, the meander is gradually meandered. X.

  From the results of this experiment 3, when the flat roller is made of rubber, the ear dust 36c does not meander in the vicinity of the pair of feed rollers, but when made of metal, meandering is observed. However, when it was made of rubber, it gradually wore and meandered. Further, when the metal roller is used, meandering is not confirmed regardless of the uneven shape of the emboss, and a good conveyance state is obtained. Thereby, it can be seen that the surface of the pressing roller 87 is preferably made of metal and embossed.

[Experiment 4]
TAC film is manufactured by changing the manufacturing speed gradually and continuously without changing the film manufacturing line, and when changing the speed at a constant thickness of 80 μm. Membrane was performed. Then, after passing through the tenter 27, the side end portion 36b was cut, and the ear dust 36c was blown by the first air blowing device 27. At each speed of film production, it is determined that the conveying state of the ear dust 36c is good, and when the production speed and the film thickness are constant, the ear dust between the feed roller pair 81 and the roller 82 at that time. The tension of 36c and the pressure of pinching by the feed roller pair 81 were measured. This result is shown in Table 4 as Experiment 4-1. In Experiment 4-2, the thickness of the manufactured film was set to 60 μm, the manufacturing speed was changed in three ways, and it was determined that the conveying state of the ear dust 36c was improved, and the manufacturing speed and the film thickness were constant. Then, the tension of the ear dust 36c between the feed roller pair 81 and the roller 82 and the pinching pressure by the feed roller pair 81 were measured. Furthermore, for Experiment 4-3, when the thickness of the film was 20 μm and the conveyance speed was 100 m / min, it was judged that the state of conveyance of the ear dust 36c was good, and the production speed and film thickness became constant In addition, the tension of the ear dust 36c between the feed roller pair 81 and the roller 82 and the pressure of pinching by the feed roller pair 81 were measured.

  From the above results, according to the present invention, it is possible to reliably convey and collect the long ears cut from the thin film of 80 μm or less that are continuously conveyed without clogging with piping or the like.

It is process drawing of the solution casting method which implemented this invention. It is the schematic of the 1st ear cut process which implemented this invention. It is a flowchart which shows the air sending method in a 1st air sending apparatus. It is a perspective view containing the partial cross section of a 1st air blower. It is a figure which shows the unevenness | corrugation of a pressing roller. It is a figure which shows another unevenness | corrugation of a pressing roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Solution film forming equipment 21 1st ear open device 22 2nd ear open device 27 1st air blower device 28 2nd air blower device 36 Film 36a Ear part 36c Ear waste 36d Strip-shaped piece 41 1st ear open process 45 Silo 47 Suction duct 50 Ionizer 52 Cut blower 59 to 68 Piping 71 to 73 Shutter 81 Feed roller pair 82 Roller 86 Drive roller 87 Pressing roller 89 Shift section 91 Duct body 92 Jacket 97 Pressing roller

Claims (16)

In a method of having a first step of blowing a film side end portion cut from a continuously conveyed film in a long shape, and blowing the side end portion to a recovery unit using the first step ,
Providing a pair of rollers for sandwiching the side end in the first step;
The air feeding method characterized in that the side end immediately before being sandwiched by the roller pair is applied with a tension of 3 N / m ² or more and 45 N / m ² or less in the longitudinal direction. The outer peripheral surface of at least one roller of the roller pair is made of rubber or metal having irregularities for suppressing slipping of the side end portion,
The air feeding method according to claim 1, wherein a narrowing pressure of the roller pair with respect to the side end portion is set to 0.05 MPa or more and 0.4 MPa or less. When changing the speed at which the film is conveyed so as to increase stepwise in units of 5 m / min to 30 m / min,
The air feeding method according to claim 1 or 2, wherein the pinching pressure by the tension or the roller pair is reduced stepwise according to the change. A second step of cutting the long side end portion into a cut piece by a cutting means;
The air sending method according to any one of claims 1 to 3, wherein an air sending distance of the side end portion to the second step is 20 m or less.   At least one of the side end portion and the side end piece is blown in an arbitrary direction except for the anti-conveying direction of the film from which the side end portion has been separated and the direction along the width direction. The air feeding method according to any one of claims 1 to 4, wherein:   The air feeding method according to claim 4 or 5, wherein the charged voltage value of at least one of the side end portion and the side end piece is set to -5 kV or more and 5 kV or less by the static electricity removing means.   The air feeding method according to any one of claims 1 to 6, wherein the film is a cellulose acylate film. The side end portion cut from the continuously transported film has a first air sending path for air-blowing in a long shape, and the side end portion is attached to the collecting portion provided downstream of the first air sending portion. In the air sending device that sends air,
A roller pair for sandwiching the side end portion in the first air passage is provided,
Upstream of the roller pair is provided with a tension control means for controlling the tension in the longitudinal direction with respect to the side end immediately before being sandwiched by the roller pair,
The air feeding device, wherein the tension control range is at least 3 N / m ^{2 to} 45 N / m ² . The outer peripheral surface of at least one roller of the roller pair is made of rubber, or made of metal having irregularities for suppressing slipping of the side end portion,
The roller pair has pressure control means for pinching the side end with a predetermined narrowing pressure;
The air feeding device according to claim 8, wherein the pressure control range is at least 0.05 MPa and 0.4 MPa or less. Connected to a transport unit for transporting the film,
When the transport unit continuously transports the film and changes the transport speed so as to increase stepwise in units of 5 m / min to 30 m / min,
The tension control means for controlling the tension to decrease stepwise according to the speed change, or the pressure control means for controlling the pressure to decrease stepwise according to the speed change. An air feeding device according to claim 8 or 9, further comprising: Cutting means for cutting the side end object to be a side end piece;
A second air passage for air feeding the side end piece,
The length of the wind path to the said cutting | disconnection means shall be 2 m or more and 20 m or less, The wind blowing apparatus as described in any one of Claim 8 thru | or 10 characterized by the above-mentioned. At least a part of the first or second air passage is a pipe,
When the pipe has a bent portion, the direction of the bend is
The air feeding device according to any one of claims 8 to 11, wherein the air feeding device has an arbitrary direction excluding an anti-conveying direction of the film and a direction along a width direction in the conveying unit. Separating means for separating the air that has blown the side end piece from the side end piece;
A return pipe for returning the air separated by the separation means to a predetermined position of the first air feed path;
The predetermined position of the first air passage is a double structure having a tube in which the long side end portion is aired and a jacket for allowing the air to flow into the tube,
The air blowing device according to claim 11 or 12, wherein the jacket includes an inlet for the air to enter.   The air blower according to any one of claims 11 to 13, further comprising a static electricity removing unit for controlling a charged voltage value of at least one of the side end portion and the side end piece.   The air feeding device according to any one of claims 8 to 14, wherein the film is a cellulose acylate film.   A method for producing a cellulose acylate film comprising using the air blowing method according to any one of claims 1 to 6 or the air blowing device according to any one of claims 8 to 14.

Images