TWI426994B - Drying apparatus and solution casting method - Google Patents

Description

Drying device and solution film forming method

The present invention relates to a solution film forming method and a drying device for a solution film forming method.

With the large screen of liquid crystal displays (LCDs), the optical film used for LCDs is also required to have a large area. After the optical film is formed into a shape, it is cut into a predetermined size in order to correspond to the LCD. Therefore, in order to manufacture a larger-area optical film, it is necessary to manufacture an elongated optical film having a larger width than ever.

As a representative production method of the elongated optical film, there is a continuous method of forming a solution film. It is known that a solution film forming method is a method in which a casting film composed of a dope is formed on a casting support by casting a concentrated solution in which a polymer is dissolved in a solvent onto a moving casting support. The cast film is peeled off from the support and dried to produce a film.

As the casting support, a metal belt is used, and the maximum width of the film that can be produced is restricted by the width of the belt. Therefore, to make a film of a larger width, a belt of a larger width is required. However, so far, only belts having a width of up to about 2 meters can be obtained.

Therefore, in the Korean Patent Laid-Open Publication No. 2009-0110082, the center belt which is the center portion in the width direction and the pair of side belts which are the side portions of the belt are welded in the longitudinal direction, thereby obtaining the width ratio. A bigger belt in the past.

However, it is described in Korean Patent Laid-Open Publication No. 2009-0110082 On the surface of the belt, the welded portion of the side belt and the center belt is exposed, and there are more defects such as pinholes in the welded portion than the side belt or the center belt. Therefore, a residual failure occurs due to a defect in the welded portion. If a residual failure occurs, the production speed of the solution film formation must be temporarily lowered or stopped, and the operation of removing the cast film remaining on the casting support can be performed. As a result, the film cannot be efficiently produced.

An object of the present invention is to provide a solution film forming method capable of efficiently producing a film by using a tape forming method having a wider width than a conventional tape, and a drying device for a solution film forming method.

In order to solve the above problems, the solution film forming method of the present invention includes a cast film forming step, a cast film drying step, a peeling step, and a film drying step. In the cast film forming step, a cast film composed of the dope is formed on the surface by continuously flowing the dope to the surface of the moving belt moving in the longitudinal direction. The dope contains a polymer and a solvent. The aforementioned moving belt is formed by welding a side member and a center member. A welded portion extending in the moving direction of the moving belt is exposed on the surface. The casting film covers the aforementioned welded portion. A pinhole having a diameter of 50 μm or more and less than 70 μm is provided in the welded portion. In the casting film drying step, dry air is blown to the casting film and the solvent is evaporated from the casting film. In the peeling step, the cast film is peeled off from the support and used as a wet film. In the film drying step, the solvent is evaporated from the aforementioned wet film.

The solution film forming method further comprises a welding step heating step good. The soldering portion heating step is performed between the film forming step and the stripping step. The welded portion heating step heats the welded portion from the back side of the moving belt.

Further, the solution film forming method of the present invention includes a cast film forming step, a cast film drying step, a peeling step, a film drying step, and a welded portion heating step. In the cast film forming step, a cast film composed of the dope is formed on the surface by continuously flowing the dope to the surface of the moving belt formed by welding the side member and the center member. The dope contains a polymer and a solvent. The aforementioned moving belt moves in the longitudinal direction. A welded portion extending in the moving direction of the moving belt is exposed on the surface. The casting film covers the aforementioned welded portion. In the casting film drying step, dry air is blown to the casting film and the solvent is evaporated from the casting film. In the peeling step, the cast film is peeled off from the support and used as a wet film. In the film drying step, the solvent is evaporated from the aforementioned wet film. The welding portion heating step is performed between the casting film forming step and the peeling step. In the welding portion heating step, the welded portion is heated from the back side of the moving belt.

The drying device of the present invention dries a cast film formed on a surface of a moving belt that moves in the longitudinal direction and is composed of a dope. The dope contains a polymer and a solvent. The drying device includes a dry air supply unit and an inner heating unit. The dry air supply unit blows dry air to the casting film. The aforementioned moving belt is formed by welding a side member and a center member. A welded portion extending in the moving direction of the moving belt is exposed on the surface. The welded portion is covered by the casting film. The inner heating portion heats the welded portion from the back side of the moving belt.

It is preferable that the inner heating portion includes a nozzle that blows heated air to the welded portion.

The moving belt is formed in a ring shape and circulates in a state of being hung on the roller, and a casting die and a peeling roller are preferably provided in this order from the upstream side in the moving direction. The casting die flows out of the aforementioned dope to the aforementioned surface. The peeling roller peels the aforementioned cast film from the aforementioned surface. It is preferable that the inner heating portion is disposed between the casting die and the separation roller in the moving direction.

The drying device is particularly effective when there is a pinhole having a diameter of 50 μm or more and less than 70 μm in the welded portion.

According to the present invention, an elongated film having a wider width than the conventional one can be produced with high efficiency.

The belt manufacturing apparatus 10 shown in Figs. 1 and 2 is an apparatus for producing an elongated belt member 13 composed of an elongated central member 12 and side members 11 provided on both sides in the width direction of the center member 12.

The side member 11 and the center member 12 are each made of a metal sheet. The side members 11 are narrow sheets of relatively narrow width. The side member 11 and the center member 12 are preferably formed of the same material, and are preferably formed of the same raw material and through the same forming process. For example, both the side member 11 and the center member 12 are preferably formed of stainless steel.

As the center member 12, a belt which has been used as a conventional casting support can be used. The width of the central member 12 is wider than that of the side member 11, and the width of the central member 12 in the present embodiment is in the range of 1500 mm or more and 2100 mm or less. Constant inside. The width of the side member 11 is constant in the range of 50 mm or more and 500 mm or less.

The tape manufacturing apparatus 10 includes a delivery unit 16 , a butt portion 17 , a welding unit 18 , a heating unit 19 , and a winding device 20 .

(sending department)

The delivery unit 16 has a first delivery device 23 that feeds the side members 11 and a second delivery device 24 that sends out the central member 12. The delivery portion 16 independently feeds the side member 11 and the center member 12 to the abutting portion 17, respectively. The side member 11 wound in a roll shape is sheathed on the first delivery device 23. The first delivery device 23 unwinds the side member 11 and sends it to the abutting portion 17. The center member 12 wound in a roll shape is sheathed on the second delivery device 24. The second delivery device 24 winds up the center member 12 and sends it to the docking portion 17.

The abutting portion 17 abuts the side member 11 and the center member which are independently guided so that the side edge 11e of the side member 11 and the side edge 12e of the center member 12 are in contact with each other. The butt portion 17 preferably has the first roller 26, the second roller 27, the third roller 28, and the fourth roller 29. The first roller 26 and the second roller 27 are disposed in order from the upstream side on the transport path of the center member 12. The third roller 28 is disposed on the transport path of the side member 11. The fourth roller 29 is disposed on the transport path so as to support both the side member 11 and the center member 12.

The butting position Pc is a position at which one side edge 11e of the side member 11 comes into contact with one side edge 12e of the center member 12. The fourth roller 29 is a butt-supporting roller that supports the side member 11 and the center member 12 that are fed at the docking position Pc.

The second roller 27 and the third roller 28 respectively adjust the center member 12 and the side structure The conveying path of the member 11 is such that the center member 12 and the side member 11 are in contact with each other on the circumferential surface of the fourth roller 29.

The second roller 27 adjusts the transport path of the center member 12, and controls the passage path of the side edge 12e to be welded to the side member 11 toward the docking position Pc. The second roller 27 is movable in the width direction Y of the center member 12. The displacement mechanism 32 moves the second roller 27 in the width direction Y.

A position detecting means 34 is disposed between the second roller 27 and the fourth roller 29. The position detecting means 34 detects the passing position of one of the side edges 12e of the center member 12, and sends a signal indicating the passing position to the controller 33. The controller 33 obtains the displacement amount of the second roller 27 in the width direction Y based on the signal of the passing position, and sends the signal of the displacement amount to the displacement mechanism 32. The displacement mechanism 32 changes the inclination of the second roller 27 or the position of the second roller 27 in the width direction Y of the center member 12 in accordance with the signal of the amount of displacement transmitted. Thus, by changing the inclination or position of the second roller 27, the center member 12 is displaced in the width direction Y.

It is preferable that the first roller 26 is provided with a displacement mechanism 37. The first roller 26 is pressed toward the center member 12 of the second roller 27 from the one member surface by the displacement mechanism 37. The pressing pressure of the first roller 26 to the center member 12 changes depending on the amount of displacement of the first roller 26. In this way, the amount of displacement of the first roller 26 is controlled to adjust the pressing pressure. Thereby, the winding center angle of the center member 12 wound around the second roller 27 can be controlled. By controlling the winding center angle, the amount of displacement of the center member 12 in the width direction Y caused by the second roller 27 can be more accurately controlled.

The third roller 28 adjusts the conveying path of the side member 11 and faces the docking The position Pc adjusts the passage path of the side edge 11e which should be welded to the central member 12. The third roller 28 is provided with a controller 38 for controlling the direction in the longitudinal direction. The third roller 28 is rotatable in the circumferential direction, and the rotating shaft is at the center of the circular cross section. Therefore, the longitudinal direction of the third roller 28 coincides with the direction of the rotation axis. The controller 38 changes, for example, the longitudinal direction of the third roller 28 along the member surface of the side member 11 so as to be at an angle θ between the circumferential direction in the contact region during contact with the side member 11 and the conveying direction X of the center member 12. 1 change.

As described above, it is preferable to control the first roller 26 to the third roller 28 such that the butting position Pc is located on the fourth roller 29. It is preferable that each of the first roller 26 to the third roller 28 is a driving roller that rotates in the circumferential direction. The first roller 26 and the second roller 27 also function as a conveying means of the center member 12 by the circumferential rotation. The third roller 28 also functions as a conveying means of the side member 11 by the circumferential rotation. By using the first roller 26 to the third roller 28 as the driving roller, the control of the conveying path of the side member 11 and the center member 12 becomes more reliable. At the same time, the first roller 26 to the third roller 28 are used as the driving roller, and the slip of the side member 11 and the center member 12 on the first roller 26 to the third roller 28 is prevented, and the scratched member surface is prevented. .

(welding unit)

The side member 11 and the center member 12 are supplied from the butting portion 17 to the welding unit 18 in a state where the side edges 11e, 12e are in contact with each other. The welding unit 18 welds the supplied side member 11 and the center member 12. By continuously supplying from the butting portion 17, the long side welding step of welding the side member 11 and the center member 12 in the longitudinal direction can be performed in the welding unit 18. The welding unit 18 is provided with a welding device 42. As the welding device 42, for example, a laser welding device can be cited. As the laser welding device, for example, a CO ₂ laser welding device or a YAG laser welding device can be used. In the present embodiment, a case where the CO ₂ laser welding apparatus is used as the welding apparatus 42 will be described.

The welding device 42 emits a laser by emitting a concentrated laser beam to the side member 11 and the center member 12 to be irradiated, thereby melting the side member 11 and the center member 12 to be joined. The welding device 42 includes a laser oscillator 43, a welding device main body 46, and a gas supply unit (not shown). The welding device main body 46 collects the laser light guided from the laser oscillator 43 and emits it. The gas supply unit supplies CO ₂ gas every time the laser is irradiated. The CO ₂ gas prevents oxidation of the side member 11 and the center member 12. In addition, in FIG. 2, the illustration of the laser oscillator 43 is abbreviate|omitted in order to avoid complication of a figure.

Instead of a laser welding device, a TIGsten Inert Gas welding device can also be used. It is well known that TIG welding is one of arc welding in which an electric arc is used as a heat source. TIG welding is one in which an inert gas (inactive gas) is used as a shielding gas, and an inert gas of tungsten or a tungsten alloy is used for arc welding on an electrode. Laser welding is better than TIG welding. Moreover, it can also be used as a hybrid welding combining TIG welding and laser welding.

A welding support roller 41 is provided on the conveying path of the side member 11 and the center member 12 so as to face the ejection opening of the laser of the welding device main body 46. The welding support roller 41 supports the side member 11 and the center member 12 by the circumferential surface. The rotation axis of the welding support roller 41 is parallel to the width direction Y of the side member 11 and the center member 12. The welding support roller is set in such a manner that the side member 11 and the center member 12 during the support to the circumferential surface of the welded support roller 41 are irradiated with laser light. The support position of the side member 11 and the center member 12 of 41 is preferable. That is, it is preferable to perform welding on the welding support roller 41. Thereby, the side members 11 and the center member 12 are stabilized in a state where the side edges 11e and 12e are in contact with each other, and the laser beam can be reliably irradiated to the portion to be irradiated.

It is preferable that the welding device main body 46 is provided with a displacement mechanism 50 for displacing in the width direction Y. A position detecting means 47 is provided upstream of the welding device 42. The position detecting means 47 detects the contact position Ps of the side edge 11e of the side member 11 and the side edge 12e of the center member 12 (refer to FIG. 5), and sends a signal of the detected contact position Ps (refer to FIG. 5) to the control. 51. The position detecting means 47 is disposed in the vicinity of the transport path from the docking position Pc to the welding device 42.

The controller 51 obtains the displacement amount of the welding device main body 46 in the width direction Y based on the signal of the contact position Ps (refer to FIG. 5) sent thereto, and sends a signal of the displacement amount to the displacement mechanism 50. When the signal of the conveying speed of the input side member 11 and the center member 12 is input, the controller 51 sends a signal of the displacement amount at which the welding device main body 46 is displaced and a signal at the timing of displacing the welding device main body 46 to the displacement. Agency 50. The displacement mechanism 50 changes the position of the welding device main body 46 at a predetermined timing based on the transmitted displacement amount and the displacement timing signal. Thus, by changing the position of the welding device main body 46 in the width direction Y, the irradiation position of the laser is more accurately controlled, and the side member 11 and the center member 12 are welded more reliably. Further, in the present embodiment, the conveying speed of the side member 11 and the center member 12 to the welding device 42 is set to be in the range of 0.15 m/min or more and 20 m/min or less.

As shown in FIG. 1, the chamber 52 and the cleaning device are disposed in the welding unit 18. 55 is even better. The chamber 52 separates the welding device main body 46 and the welding support roller 41 from the external space. The cleaning device 55 cleans the gas. In addition, in FIG. 2, illustration of the chamber 52 and the cleaning device 55 is omitted in order to avoid complication of the drawing. The chamber 52 is provided with a first opening (not shown) for discharging the internal gas to the outside, and a second opening (not shown) for guiding the gas cleaned by the cleaning device 55 to the inside. The first opening and the second opening are connected to the cleaning device 55, respectively. The internal gas of the chamber 52 is guided from the first opening to the cleaning device 55. The cleaning device 55 cleans the gas guided from the chamber 52 and sends it to the chamber 52 through the second opening. Thus, the internal gas of the chamber 52 circulates between the cleaning devices 55.

By cleaning the internal gas of the chamber 52, the welding position Pw and its periphery are cleaned, and foreign matter or the like is prevented from being mixed into the welded portion 13w. Further, by maintaining the internal pressure of the chamber 52 higher than the pressure of the external space, the inside of the chamber 52 can be more reliably maintained in a clean state. Further, by bringing the welding position Pw to a relatively high position with respect to the delivery portion 16, the abutting portion 17, the heating portion 19, and the winding device 20, it is possible to further prevent introduction of foreign matter from these portions.

The internal cleanliness of the chamber 52 is preferably set to 1000 or less as defined in the U.S. Federal Standard FED-STD-209D, and more preferably 100 or less.

(heating section)

It is preferable that the heating portion 19 is provided downstream of the welding unit 18. The heating unit 19 is not particularly limited as long as the welded portion 13w of the belt member 13 obtained by welding is heated to a constant temperature range. In the welding part 13w In the periphery and the periphery, the stress caused by the strain caused by the welding sometimes remains inside. The stress can be removed by heating the welded portion 13w or its periphery by the heating portion 19. By removing this stress, deformation of the welded portion 13w can be suppressed even when the solution film forming method is continuously performed for a long period of time.

The temperature of the welded portion 13w heated by the heating portion 19 is not particularly limited as long as the temperature at which the stress is removed. However, for example, when the belt member 13 is made of stainless steel, the temperature of the welded portion 13w is preferably 100 ° C or more and 200 ° C or less, and more preferably 120 ° C or more and 180 ° C or less.

As the heating unit 19, for example, there is a blowing means. As shown in Fig. 1, the air blowing means as the heating unit 19 has a duct 56 for blowing a constant temperature of the gas, and a blower 57 for supplying the gas to the duct 56 after the temperature of the control gas. In addition, in FIG. 2, in order to avoid complication of a drawing surface, illustration of the blower 57 is abbreviate|omitted.

The heating portion 19 may be provided on the transport path of the belt member 13 on the opposite side of the welding support roller 41 as shown in FIG. 1 or on the same side as the welding support roller 41.

The stress-removed belt member 13 is sent to the winding device 20 downstream of the heating portion 19, and is wound into a roll shape. The winding device 20 is sleeved with a winding core of the take-up belt member 13. The winding device 20 is provided with a driving means for rotating the winding core in the circumferential direction.

The winding device 20 also functions as a welding tension control means for controlling the tension of the belt member 13 and the side member 11 and the center member 12 at the welding position Pw. Therefore, the winding of the belt member 13 at the welding position Pw and the tension of the side member 11 and the center member 12 are kept constant. The torque of 20 is preferred. Thereby, the welded portion 13w can be made constant in the longitudinal direction.

When the welding is started, it is preferable to use, for example, the winding device 20 as follows. First, the side member 11 and the center member 12 are sleeved on the conveyance path from the delivery portion 16 to the winding device 20, and the respective ends of the side member 11 and the center member 12 are wound around the winding core of the winding device 20. The winding side member 11 and the center member 12 are started to be wound. The winding path of the side member 11 and the center member 12 is started to be taken up and controlled, thereby holding the docking position Pc at a predetermined position. After the butting position Pc of the side member 11 and the center member 12 is kept constant, the welding is started by the welding device 42.

(to prevent deviation)

It is preferable to perform welding while suppressing the positional deviation of the side member 11, the center member 12, and the belt member 13. For example, the welding unit 61 as shown in FIGS. 3 and 4 including the pressing device may be used instead of the welding unit 18. The welding unit 61 is further provided with a pressing device 62 as shown in FIGS. 1 and 2 . Like the welding unit 18, the welding unit 61 includes the displacement mechanism 50, the controller 51, the chamber 52, and the cleaning device 55. However, in order to avoid complication of illustration, these illustrations are omitted in FIGS. 3 and 4. The same components and members as those in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof will be omitted. Further, in the welding unit 61, the chamber 52 is surrounded by the pressing device 62 and the welding support roller 41 from the external space.

The pressing device 62 suppresses the positional deviation of the side member 11, the center member 12, and the belt member 13 at the welding position Pw. Pressing device 62 by The first conveyor belt 63 and the second conveyor belt 64 constitute a pair of conveyor belts, and the side members 11, the center member 12, and the belt member 13 on the support roller 41 are welded.

The first conveyor belt 63 and the second conveyor belt 64 are endless belts formed in a ring shape. The first conveyor belt 63 and the second conveyor belt 64 are wound around the circumferential surfaces of the fifth roller 67 to the seventh roller 69 so as to be aligned in the longitudinal direction of the fifth roller 67 to the seventh roller 69. At least one of the fifth roller 67 to the seventh roller 69 is a driving roller that rotates in the circumferential direction. By the rotation of the driving roller, the first conveyor belt 63 and the second conveyor belt 64 are conveyed while maintaining mutually parallel conveying paths.

The fifth roller 67 to the seventh roller 69 are disposed such that the rotation axis is parallel to the rotation axis of the welding support roller 41.

The fifth roller 67 to the seventh roller 69 are disposed on the transport path of the side member 11 and the center member 12 on the side opposite to the side on which one of the fourth roller 29 and the welding support roller 41 is disposed. The fifth roller 67 is provided to face the transport path from the fourth roller 29 toward the side member 11 of the welding support roller 41 and the center member 12. The sixth roller 68 is disposed to face the transport path from the welding support roller 41 toward the side member 11 of the heating portion 19 and the center member 12. The seventh roller 69 is appropriately disposed to determine the transport path from the sixth roller 68 toward the first conveyor 63 and the second conveyor 64 of the fifth roller 67.

The fifth roller 67 and the sixth roller 68 are disposed such that the side member 11 on the welding support roller 41, the center member 12, and the belt member 13 are pressed from the fifth roller 67 toward the first conveyor belt 63 and the second conveyor belt 64 of the sixth roller 68. Way to transmit. For example, when the side member 11 and the center member 12 on the welding support roller 41 are welded from above, the fifth roller 67 and the sixth roller 68 are disposed such that each of them The lower end becomes a position lower than the upper end of the welding support roller 41.

The fifth roller 67 and the sixth roller 68 are disposed such that the transport path of the first conveyor belt 63 faces the transport path of the side member 11 and the side portion 13s of the belt member 13 formed by the side member 11. Further, the fifth roller 67 and the sixth roller 68 are disposed such that the transport path of the second conveyor belt 64 faces the transport path of the center member 12 and the central portion 13c of the belt member 13 formed by the center member 12. Thereby, the first conveyor 63 presses the side member 11 and the side portion 13s to the welding support roller 41, and the second conveyor belt 64 presses the center member 12 and the center portion 13c toward the welding support roller 41.

As described above, the first conveyor belt 63 and the second conveyor belt 64 are respectively disposed to face the welding support roller 41, and are pressed so that the heights of the side members 11 and the center member 12 at the welding position Pw become the same. The height of the side members 11 and the center member 12 is the height of the surface of each of the members 11, 12. By pressing the side member 11 and the center member 12 in such a manner that the height becomes the same, and performing welding in this state, the aspect of the welded portion 13w becomes more uniform in the longitudinal direction, and can be more reliably Welding is performed.

The long side welding process will be described in further detail with reference to FIGS. 5 and 6. The first conveyor belt 63 and the second conveyor belt 64 are conveyed in a state of being separated from each other. The first conveyor and the second conveyor 64 set the transmission path so that the gap between the first conveyor 63 and the second conveyor 64 is at the welding position Pw. Thereby, the contact position Ps of the side edge 11e of the side member 11 and the side edge 12e of the center member 12 is passed through the gap between the first conveyor belt 63 and the second conveyor belt 64 as shown in FIG. 5, and is in the first conveyor belt 63. It is welded to the second conveyor belt 64. In addition, the main body of the welding device is omitted in FIG. Illustration of 46.

The interval D1 between the first conveyor belt 63 and the second conveyor belt 64 is preferably in the range of 6 mm or more and 12 mm or less. In the cross section in the width direction Y of the side member 11 and the center member 12, the distance D2 between the contact position Ps and the first conveyor 63, and the distance D3 between the contact position Ps and the second conveyor belt 64 are set to 3 mm or more and less than 6, respectively. A range of millimeters is preferred.

Instead of the pressing device 62, a roller (not shown) having a rotation axis parallel to the rotation axis of the welding support roller 41 may be disposed upstream and downstream of the welding device main body 46, respectively. At this time, the side member 11 and the center member 12 are pressed by the upstream one roller, and the belt member 13 is pressed by the other downstream roller, whereby the side member 11 and the center member 12 at the welding position Pw can be pressed.

As shown in FIG. 6, the welding bead 72 is formed by the heat of the welding device 42 being dissolved at the contact position Ps and its periphery. Heat is transferred from the welding bead 72 to both sides, so that the heat-affected zone 73 affected by the heat at the time of welding is generated in the side member 11 and the center member 12, respectively. The heat-affected zone 73 sometimes exhibits traits that are different from other zones that are not affected by heat, either immediately or over time. For example, when such a wide-ranging heat-influencing person is used as a casting support, when the solution film forming method is continuously performed for a long period of time, disadvantages such as deformation of the welded portion 13w or foaming of the cast film may occur.

Therefore, as shown in FIG. 5, a high heat conduction portion 71 composed of a material having a higher thermal conductivity than the side member 11 and the center member 12 is formed in a region passing through the contact position Ps in the circumferential surface of the welding support roller 41. good. Thereby, the welding device 42 can be diffused more quickly (refer to FIG. 3 and FIG. 4) The heat. In order to spread heat more rapidly on the side of the welding support roller 41, the width of the heat-affected zone 73 of the side member 11 and the center member 12 may be further reduced, or the depth of the heat-affected zone 73 may be made shallower.

It is preferable that the width D4 of the passage region of the high heat conduction portion 71 is 26 mm or more and 32 mm or less.

Further, it is more preferable to form a high heat conduction portion made of a material having a higher thermal conductivity than the side member 11 and the center member 12 on both surfaces of the first conveyor belt 63 and the second conveyor belt 64. Thereby, the size of the heat-affected zone 73 can be reduced in the width direction or the thickness direction.

The side edge 11e of the side member 11 and the side edge 12e of the center member 12 are preferably in a state of being adhered so that the gap at the contact position Ps becomes 0 (zero). Therefore, it is preferable that the side member 11 and the center member 12 are formed in advance so as not to form a gap when the side edges 11e and 12e are butted. Thereby, the belt member 13 which has no gap in a welded part can be manufactured more reliably.

The long-side welding step may be a continuous welding step in which welding is continuously performed only in the longitudinal direction of the side members 11 and the center member 12, and an intermittent welding step in which intermittent welding is performed may be performed. If the welding is intermittent, the side member 11 and the center member 12 which are continuously fed to the welding device 42 are intermittently welded. This intermittent welding step is preferably carried out before the continuous welding step. At this time, in the intermittent welding process, after the side member 11 and the center member 12 are temporarily joined, the joining may be performed over the entire lengthwise direction in the continuous welding step.

When the joining is performed in the continuous welding process after the temporary joining in the intermittent welding process, the side member 11 and the center member 12 are taken from the butting portion 17 (see Referring to Figures 1 and 2), the welding unit 18 is guided and intermittently welded. Further, when the side member 11 and the center member 12 are provided with a surface corresponding to the casting surface when used as the rear casting support and the inside corresponding to the non-casting surface, the inside is subjected to the intermittent welding process. Welding is preferred. Therefore, the side member 11 and the center member 12 are conveyed in such a manner that the inside faces the welding device main body 46 (refer to FIG. 1).

After the intermittent welding process, the temporarily joined side members 11 and the center member 12 are guided to the winding device 20 and wound up. Further, the welded portion may be heated by the heating portion 19 before the winding. The temporary joining member (not shown) composed of the side member 11 and the center member 12 which are wound by the intermittent welding step is taken up by a feeding device (not shown) and sent to the welding unit 18 again. This delivery is performed in such a manner that the surface of the temporary welding member faces the welding device main body 46 (refer to FIG. 1). Continuous welding is performed in the welding unit 18 to obtain the belt member 13. Further, two welding units 18 may be arranged side by side in the upstream and downstream directions, and intermittent welding may be performed in one of the upstream welding units 18, and continuous welding may be performed in the other welding unit 18 downstream. Instead of the above method.

If welding is performed, the welding bead 72 may be more convexly formed than the side member 11 and the center member 12. Therefore, it is preferable to form the groove 76 in the welding support roll 41 used in the first step of welding one surface in the longitudinal direction and the second step of welding the other surface in the longitudinal direction. As shown in FIG. 5, the groove 76 is formed in a passing region through which the contact position Ps passes in the circumferential surface of the welding support roller 41. The conveying portion formed by the welding bead 72 raised in the first step passes through the groove 76, and the conveying side structure The member 11 and the central member 12 may be subjected to the second step. Thereby, the belt member 13 which is smoother and has less residual stress can be obtained. Therefore, even if it is used for film formation in a solution, deformation or a change in properties is less in the tape as a casting support, and it is possible to more reliably produce a film in which the casting film does not foam and has no thickness unevenness. .

The width D5 of the groove 76 is preferably in the range of 6 mm or more and 12 mm or less, and the depth D6 of the groove may be about 1 mm.

In the above embodiment, the third roller 28 is used as a means for adjusting the conveying path of the side members 11 in the abutting portion 17. However, instead of the third roller 28, a tapered roller 81 as shown in Fig. 7 may be used. The tapered roller 81 is a cross-sectional circular roller formed such that the diameter d continuously decreases from one end toward the other end. The diameter d decreases continuously in a constant ratio from one end toward the other. The tapered roller 81 is disposed such that one end having a larger diameter d faces the transport path of the center member 12 and the other end having a smaller diameter d faces the opposite side of the center member 12.

The side member 11 during conveyance is brought into contact with the tapered roller 81, thereby changing the path of conveyance to the direction of the arrow A toward the center member 12, and close to the center member 12. Thereby, the side member 11 can be reliably conveyed toward the docking position Pc (refer to FIGS. 1 and 2).

It is preferable that the tapered roller 81 is provided with a driving means 82 that rotates in the circumferential direction. The rotating shaft is inserted through the center of one end surface and the center of the other end surface. The side member 11 is conveyed by the tapered roller 81 rotated by the driving means 82, so that the side member is more effectively approached to the central member 12.

Instead of the third roller 28, a clip 85 as a holding means as shown in Fig. 8 can also be used. Clip 85 has been opened for The clip-shaped main body 86 and the pair of gripping fingers 87 provided at the respective distal end portions of the clip main body 86 hold and hold the side members 11. The gripping needle 87 is movably disposed between the gripping position of the grip side member 11 and the retracted position retracted from the gripping position. The clip 85 is provided with a displacement mechanism 88, and is movable between a grip start position at which gripping is started and a grip release position at which gripping is released. Further, the clip 85 is also movable in the width direction Y.

The clip 85 grips the side member 11 by moving the holding pin 87 to the holding position at the gripping start position. In the state in which the side member 11 is gripped, the clip 85 is conveyed downstream while being close to the width direction of the center member 12.

The tapered roller 81 and the clip 85 can be used to bring the center member 12 closer to the side member 11 in addition to the side member 11 being brought close to the center member 12. At this time, the central member 12 may be supported or conveyed by the tapered roller 81 and the clip 85.

In the above embodiment, the two side members 11 are simultaneously welded to the center member 12. However, one of the side members 11 may be welded to the center member 12, and the other side member 11 may be welded to the center member 12.

(band)

As shown in Fig. 9, the belt 91 used as the casting support is an endless belt having an annular shape. One end and the other end of the belt-welded belt member 13 in the longitudinal direction are formed. Further, the belt member 13 for producing the belt 91 can be cut to a predetermined length, and when the belt member 13 is produced from the side member 11 and the center member 12 which have been previously cut to a predetermined length, the belt can be directly produced without cutting. 91.

It is preferable that the belt member 13 is cut in a direction intersecting the width direction Y. Regarding the direction of the shearing, it is more preferable to cut in such a manner that the angle formed by the width direction Y is approximately 5 or more and 15 or less. The endless belt 91 is produced by welding one end of the belt member 13 in the longitudinal direction and the other end. The angle θ 2 formed by the welded portion 91v and the other end of the welded portion 91v and the width direction Y is approximately 5° or more and 15° or less. As described above, in the annular welding step in which the elongated belt member 13 is formed in a ring shape, the welding device 42 used in the long-side welding step can be used, and other known welding devices can be used.

The belt 91 manufactured by welding includes a side portion 91s formed by the side members 11 (refer to Figs. 1 to 8) and a central portion 91c formed by the center member 12 (refer to Figs. 1 to 8). The welded portion 91w of the side portion 91s and the central portion 91c is exposed on the surface 91a or the inner surface 91b. The welded portion 91w is a portion corresponding to the welded portion 13w. It is preferable that the linear welded portion 91w is provided in parallel with the longitudinal direction of the belt 91. The width of the belt 91 thus obtained is in the range of 2000 mm or more and 3000 mm or less.

The obtained belt 91 is used in a solution film forming apparatus after being surface-polished and mirror-finished. A method of manufacturing a film using the belt 91 will be described below. The type of the polymer is not particularly limited, and a known polymer which can form a film in a solution film can be used. In the following embodiments, a case where a cellulose halide is used as a polymer will be described as an example.

(solution film making equipment)

As shown in FIG. 10 and FIG. 11, the solution film forming apparatus 110 is provided with a film forming apparatus 117, a first tenter 120, and a roll drying apparatus in this order from the upstream side. 124. The second tenter 125, the slitter 126, and the winding device 127. The film forming apparatus 117 forms a film 116 from the dope 113 obtained by dissolving the cellulose halide 111 in the solvent 112. The first tenter 120 is dried while holding the side portions of the film 116 by the holding means 119. The roller drying device 124 is dried while supporting the film 116 by a plurality of rollers 122. The second tenter 125 holds the side portions of the film 116 by the holding means, and applies tension to the film 116 in the width direction. The slitter 126 cuts off the holding traces of the respective side portions held by the holding means of the second tenter 125. The winding device 127 winds the film 116 around the winding core and forms a roll.

(film forming device)

The film forming apparatus 117 includes a pair of rolls 131 and 132 that rotate in the circumferential direction. The pair of rolls 131 and 132 are horizontally arranged, and a belt 91 is wound around the circumferential surfaces of the rolls 131 and 132. At least one of the rolls 131 and 132 may be a drive roll having a driving means.

Each of the rollers 131 and 132 is provided with a first controller (not shown) and a second controller (not shown) for controlling the peripheral temperature to a predetermined temperature.

In the film forming apparatus 117, a casting die 133 that discharges the dope 113, a film drying device, and a peeling roller 135 are sequentially disposed from the upstream side toward the downstream side in the moving direction of the belt 91.

(casting die)

The casting die 133 is disposed above the belt 91 and is positioned directly above one of the rollers 131. However, the casting die 133 may be disposed between one of the rollers 131 and the other roller 132 instead of being disposed directly above one of the rollers 131. In addition, the casting die 133 is disposed on one of the rollers 131 and the other When the square rolls 132 are disposed between each other, the belt 91 can be disposed at a position opposed to the casting die 133 (not shown), and the belt 91 can be supported by the rolls.

The casting die 133 is disposed such that the outflow port 133a flowing out of the dope 113 faces the surface 91a of the belt 91. The slit-shaped outflow port 133a is formed to face the one side portion 91s, the center portion 91c, and the other side portion 91s in the entire width direction of the surface 91a.

In addition, the decompression chamber for decompressing the upstream side region of the so-called liquid bead from the casting die 133 to the belt 91 may be disposed on the upstream side of the casting die 133 in the moving direction of the belt 91. . Thereby, it is possible to suppress the vibration of the liquid bead caused by the wind, and to prevent thickness unevenness and the like. In addition, the carrying wind refers to a wind that occurs in the vicinity of the surface 91a as the belt 91 moves, and flows in the moving direction of the belt 91.

(film drying device)

The film drying device includes a first duct 141 to a third duct 143 and an inner heating portion 144.

(catheter)

The first duct 141 to the third duct 143 send dry air toward the casting film 136. The first duct 141 to the third duct 143 are sequentially disposed from the upstream side along the movement path of the belt 91. The first duct 141 is provided above the rollers 131 and 132. The third duct 143 is disposed below the rollers 131 and 132. The second duct 142 is provided between the first duct 141 and the third duct 143.

Each of the first to third conduits 141 to 143 is connected to a blower (not shown). The air blower is connected to the blower to independently control the temperature, humidity, and flow rate of the gas supplied to the first duct to the third ducts 141 to 143. (not shown). The first to third conduits 141 to 143 are provided with a delivery port for sending the gas supplied from the blower as dry air. The delivery ports provided in the first to third conduits 141 to 143 are formed to face the entire surface 91a, that is, one side portion 91s, the center portion 91c, and the other side portion 91s.

The outflow ports provided in the first duct 141 to the third duct 143 are formed in a slit shape and extend in the width direction of the belt 91. The length of each of the outflow ports in the width direction of the belt 91 may be such that the dry air is blown to the entire casting film 136.

The temperature of the dry wind becomes higher as it goes from the upstream side toward the downstream side of the moving path of the belt 91. The temperature of the dry air from the first duct 141 is preferably 50° C. or higher and 140° C. or lower, and the temperature of the dry air from the second duct 142 is preferably 50° C. or higher and 140° C. or lower, and the dry air from the third duct 143 is preferably used. The temperature is preferably from 40 ° C to 100 ° C.

(inside heating section)

The inner heating portion 144 is provided between the roller 131 and the roller 132. As shown in FIGS. 12 and 13, the inner heating unit 144 includes a nozzle 151 that sends out the heated air 150. The nozzle 151 is disposed so that the side of the inner surface 91b of the belt 91 faces the welded portion 91w. When the heated air 150 sent from the nozzle 151 is blown to the welded portion 91w, the welded portion 91w is heated.

It is preferable that the nozzles 151 are arranged in the moving direction of the belt 91. When the plurality of welded portions 91w are provided on the belt 91, it is preferable to provide the nozzle 151 so that the heated air 150 is blown to all the welded portions 91w.

The temperature of the heating air 150 is not particularly limited, and is, for example, 40 ° C or higher. It is preferably 70 ° C or less.

(transfer)

Referring back to Fig. 10, a blower (not shown) may be disposed on the transport path between the film forming apparatus 117 and the first tenter 120. The film 116 is dried by blowing air from the air blowing device.

(1st tenter)

The first tenter 120 holds the both side edges of the film 116 by the clip 110 and conveys them in the longitudinal direction, and applies tension to the width direction to enlarge the width of the film 116. In the first tenter 120, a preheating zone, a stretching zone, and a relaxation zone are formed in this order from the upstream side. In addition, the relaxation zone can also be omitted.

The first tenter 120 includes a pair of guide rails (not shown) and a chain (not shown). The guide rails are disposed on both sides of the conveying path of the film 116, and the pair of guide rails are separately disposed at predetermined intervals. The guide rail is constant in the preheating zone and gradually widens in the stretch zone as it goes downstream, and is constant in the relaxation zone. In addition, the rail spacing of the loose zone can be made narrower as it goes downstream.

The chain is hung around the drive sprocket and the driven sprocket (not shown) and is movably mounted along the guide rail. A plurality of holding means 119 are attached to the chain at predetermined intervals. The holding means 119 is cyclically moved along the guide rail by the rotation of the drive sprocket.

The holding means 119 starts to hold the guided film 116 near the entrance of the first tenter 120, moves toward the exit, and releases the holding in the vicinity of the exit. The holding means 119, which has been released, moves again toward the vicinity of the entrance, and holds the film 116 that has been re-guided.

The conduit 155 is disposed above the transport path of the membrane 116. Catheter 155 A slit for sending dry air is supplied from a blower (not shown). The blower sends dry air adjusted to a predetermined temperature or humidity to the duct 155. The conduit 155 is disposed such that the slit faces the transport path of the membrane 116. Each slit has a shape that extends long in the width direction of the film 116, and is formed at a predetermined interval from each other in the conveying direction. Further, the duct 155 may be provided below the transport path of the film 116 instead of being disposed above. Alternatively, the conduit 155 may be disposed above and below the transport path of the membrane 116.

In the first tenter 120, the film is conveyed while being dried by the dry air from the duct 155 while the width is changed by the holding means 119 at a predetermined timing.

The solvent content of the film 116 in the stretching zone is 2% by mass D.B. or more and 250% by mass D.B. or less is preferably 2% by mass D.B. or more and 100% by mass D.B. or less. The elongation ratio ER1 (={(width after stretching)/(width before stretching)}×100) at the time of stretching treatment is preferably more than 100% and 140% or less. The temperature of the film 116 at the time of the stretching treatment is preferably 95 ° C or more and 150 ° C or less.

In the present specification, the solvent content rate (unit: mass % DB) is a value based on the dry amount. Specifically, when the mass of the solvent is x and the mass of the film 116 is y, {x/ (yx)}×100 find the value.

(roller drying device)

The atmosphere inside the roll drying device 124 is adjusted in temperature, humidity, and the like by an air conditioner (not shown). A plurality of rolls 122 are disposed on the roll drying device 124, and the film 116 is wound around the rolls and conveyed. In the roll drying unit 124, the solvent evaporates from the membrane 116. Drying process in the roll drying device 124 It is preferred that the solvent content is 5% by mass or less.

Further, when the film 116 fed from the roll drying device 124 is curled, a curl correcting device (not shown) for correcting the curl and flattening the film 116 may be provided between the roll drying device 124 and the second tenter 125.

(2nd tenter)

The second tenter 125 stretches the film 116. By this stretching, the film 116 having the desired optical characteristics is obtained. The obtained film 116 can be utilized as a retardation film. The second tenter 125 has the same configuration as the first tenter 120. Further, the duct 157 provided in the second tenter 125 flows out of the slit (not shown) to dry air heated to a predetermined temperature, and the dry air flows toward the film 116.

The stretching ratio ER2 (={(width after stretching)/(width before stretching)}×100) in the second tenter 125 is more than 105% and 200% or less is preferable, 110 More than 160% of the above is more preferable. The solvent content of the film 116 at the start of stretching is preferably 5 mass% D.B. or less, more preferably 3 mass% D.B. or less. The temperature of the film 116 at the time of stretching is preferably 100 ° C or more and 200 ° C or less.

The second tenter 125 may be omitted depending on the optical characteristics of the film 116 for the purpose of manufacturing.

When the film 116 is guided, the slitter 126 downstream of the second tenter 125 cuts off the holding traces generated by the respective holding means 119, 158 of the first tenter 120 or the second tenter 125. Side. The film 116 on which the side portion is cut off is sent to the take-up device 127 and taken up in a roll shape.

Cooling can also be provided between the second tenter 125 and the slitter 126 The film 116 from the second tenter 125 is cooled and cooled (not shown).

Next, the action of the present invention will be described.

The belt 91 is cyclically moved in the longitudinal direction by the rotation of the driving roller. The casting die 133 continuously flows out of the dope 113 toward the surface 91a of the belt 91. The dope 113 is cast on the belt 91. As a result, the welded portion 91w exposed on the surface 91a is covered on the belt 91, and the casting film 136 is formed.

The first duct to the third ducts 141 to 143 send dry air from the outflow port toward the casting film 136. When the dry air is blown from the first duct to the third ducts 141 to 143 to the casting film 136, the solvent evaporates from the casting film 136.

The casting film 136 which is peeled from the belt 91 in a state containing a solvent to the extent that it can be conveyed to the first tenter 120 by evaporation of the solvent. At the time of peeling, the film 116 is supported by a peeling roller (hereinafter referred to as a peeling roll) 137, and the peeling position at which the casting film 136 is peeled off from the belt 91 is kept constant. Further, the peeling roller 135 may be a driving roller that includes a driving means and rotates in the circumferential direction. The peeled cast film 136, that is, the film 116 is guided to the first tenter 120.

The casting film 136 peeled off by the peeling roller 135 is formed to cover the welded portion 91w provided on the belt 91. However, in the surface 91a, the welded portion 91w has many defects such as pinholes as compared with other portions. Therefore, the portion of the casting film 139 in the welded portion 91w is liable to cause residue due to the presence of defects.

As shown in Fig. 12, in the present invention, the welded portion 91w is heated from the inner surface 91b side before the cast film 136 is peeled off, so that the portion on the welded portion 91w is sufficiently dried. As described above, according to the present invention, the casting film 136 can be peeled off from the peeling roller 135 while suppressing the residue due to the defect.

A pinhole is included in the welded portion 91w. The present invention can be applied even when a pinhole having a diameter of 50 μm or more and less than 70 μm is included in the welded portion 91w. For example, in the welded portion 91w, a pinhole having a diameter of 50 μm or more and less than 70 μm is preferably 5 pieces/meter or less, and a pinhole having a diameter of 50 μm or more and less than 70 μm is preferably 1/mm or less. Here, "pieces/meter" is the number of pinholes included in the welded portion 91w in the range of the length in the longitudinal direction of the belt 91, and "pieces/mm" is in the longitudinal direction of the belt 91. The number of pinholes included in the welded portion 91w per mm range. Further, it is preferable that pinholes having a diameter of 70 μm or more are not present in the welded portion 91w.

In the above embodiment, the drying of the casting film 136 by the inner heating portion 144 is performed simultaneously with the drying of the casting film 136 by the dry air. However, the present invention is not limited thereto, and drying of the casting film 136 by the inner heating portion 144 and drying of the casting film 136 by the dry air can be switched.

In the present embodiment, the inner heating portion 144 is disposed such that the transmission belt 91 faces the third duct 143. However, the present invention is not limited thereto, and the inner heating portion 144 may be provided such that the transmission belt 91 faces the first duct 141. Further, a heating portion that heats the welded portion 91w from the side of the inner surface 91b may be provided in a portion of the roller 132 that is in contact with the welded portion 91w.

Further, from the viewpoint of preventing foaming, the drying of the casting film 136 by the inner heating portion 144 is performed at a certain timing, that is, the inner heating portion 144 is disposed to face the third conduit 143. good. The drying film 136 based on the inner heating portion 144 is carried out with respect to the casting film 136 having a solvent content of 30% by mass D.B. or more and 100% by mass D.B. or less. It is better.

In the above embodiment, the width of the center member 12 is made wider than the width of the side member 11, but the present invention is not limited thereto, and the width of the center member 12 may be equal to the width of the side member 11 or narrower than the width of the side member 11. Further, the number of constituent members (center member or side member) constituting the belt 91 is not limited to three, and may be two or four or more.

In the above-described embodiment, the welded portion 91w parallel to the moving direction is heated from the side of the inner surface 91b. However, the present invention is not limited thereto, and the welded portion that intersects the moving direction can be heated from the inner surface 91b side.

(condensation drying)

In the present embodiment, a film drying device including the first to third conduits 141 to 143 is used to dry the casting film 136. However, the present invention is not limited thereto, and other drying means may be used. As another drying means, for example, a drying means including a condenser may be used, and this means may be used instead of the drying means including the first to third conduits 141 to 143, or may be additionally used.

(window)

As shown in FIGS. 14 and 15, a pair of windshield plates 170 may be provided between the first duct 141 and the side portion 91s. The windshield 170 disposed along the moving direction of the belt 91 is disposed in an upright posture. By the windshield 170, the dry air from the first duct 141 can be prevented from being blown to the side portion 91s of the belt 91, so that deformation of the side portion 91s due to heating of the dry air can be prevented. The deformation of the side portion 91s is, for example, a case where the side portion 91s floats from the rollers 131, 132 or the like.

Further, the pair of windshields 170 may be provided between the second duct 142 and the side portion 91s or between the third duct 143 and the side portion 91s.

(squeeze roller)

It is preferable to provide a pair of rolls 147 on the upstream side from the start of the contact start position of the contact strip 91 from the dope 113 of the casting die 133. The pair of rollers 147 are disposed to sandwich the side portions 91s together with the rollers 131. Similarly, it is preferable to arrange a pair of rollers 165 at the side downstream of the contact start position. The side portions 91s can be pressed by the rollers 147, 165, and the floating of the side portions 91s of the dope flow delay can be more reliably prevented.

It is preferable that the rollers 147, 165 are driving rollers that are rotated by a driving means. It is preferable that the rollers 147, 165 rotate at the same speed as the conveying speed of the belt 91. Thereby, it is possible to suppress generation of frictional heat of the side portion 91s caused by contact of the belt 91 with the roller 147 or contact of the belt 91 with the roller 165, and it is possible to more reliably prevent deformation of the side portion 91s.

In the present embodiment, a pair of rollers 147 and 165 are disposed upstream and downstream of the contact position, but they may be disposed in either one of the upstream and downstream. That is, it is possible to use a pair of rollers 147 and one pair of rollers 165.

(polymer)

The polymer which can be used in the present invention is not particularly limited as long as it is a thermoplastic resin, and examples thereof include a cellulose halide 111, a lactone ring-containing polymer, a cyclic olefin, and a polycarbonate. Among them, a cellulose halide and a cyclic olefin are preferable, and a cellulose halide containing an acetate group or a propionate group and a cyclic olefin obtained by addition polymerization are preferred.

(cellulose cellulose)

As the cellulose halide 111, the sulfhydryl group is taken from the hydroxyl group of the cellulose. It is preferred that the degree of generation satisfies the following formulas (I) to (III). In the following formulae (I) to (III), A and B represent the degree of substitution of a sulfhydryl group with a hydrogen atom in a hydroxyl group of cellulose, A is a degree of substitution of an acetyl group, and B is a carbon number of 3 to 22. The degree of substitution of thiol. It is preferred that 90% by mass or more of the cellulose halide is 0.1 to 4 mm. Among them, the present invention has a particularly large effect when cellulose diacetate (DAC) is used as the cellulose oxime.

The glucose unit constituting the cellulose which is β-1,4 bonded has a hydroxyl group which is free to the 2, 3 and 6 positions. The cellulose oxime is a polymer (polymer) which esterifies a part or the whole of these hydroxy groups by a fluorenyl group having 2 or more carbon atoms. The thiol substitution degree refers to a ratio at which the hydroxyl groups of cellulose are esterified to the 2, 3, and 6 positions, respectively (the degree of substitution is 1 when esterification is 100%).

The total degree of substitution is preferably 2.00 to 3.00 for DS2+DS3+DS6, more preferably 2.22 to 2.90, and particularly preferred for 2.40 to 2.88. Further, the value of DS6/(DS2+DS3+DS6) is preferably 0.28, more preferably 0.30 or more, and particularly preferably 0.31 to 0.34. Wherein DS2 is a ratio in which a hydrogen of a 2-hydroxyl group in a glucose unit is substituted by a mercapto group (hereinafter referred to as a "2-position thiol substitution degree"), and DS3 is a ratio in which a hydrogen of a 3-hydroxy group in a glucose unit is substituted with a mercapto group. (hereinafter referred to as "3-position thiol substitution degree"), and DS6 is a ratio in which hydrogen at the 6-position hydroxyl group in the glucose unit is substituted with a mercapto group (hereinafter referred to as "6-position thiol substitution degree").

The mercapto group used in the cellulose halide of the present invention may be used alone or in combination of two or more kinds. When two or more kinds of fluorenyl groups are used, one of them is preferably an acetamino group. When the sum of the degree of substitution of the hydroxyl groups at the 2, 3, and 6 positions with the decyl group is DSA, the sum of the degree of substitution of the hydroxyl groups at the 2, 3, and 6 positions with a thiol group other than the ethyl fluorenyl group When DSB is set, the value of DSA+DSB is preferably 2.22 to 2.90, and 2.40 to 2.88 is particularly preferable.

Further, DSB is preferably 0.30 or more, and 0.7 or more is particularly preferable. Further, in the DSB, a substituent of 20% or more of the 6-position hydroxyl group is preferred, 25% or more is more preferable, 30% or more is further more preferable, and 33% or more is particularly preferable. Further, it is preferable that the value of DSA + DSB in the 6-position of the cellulose halide is 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more, particularly preferably cellulose silicide. Therefore, it is possible to produce a dope having more excellent solubility. In particular, when a non-chlorine-based organic solvent is used, it is possible to produce a concentrated liquid which exhibits excellent solubility and is excellent in low viscosity and filterability.

The cellulose which is a raw material of the cellulose halide can also be obtained from any of cotton wool fibers and pulp.

The fluorenyl group having 2 or more carbon atoms of the cellulose oxime in the present invention may be an aliphatic group or an aryl group, and is not particularly limited. For example, an alkylcarbonyl ester, an olefinic carbonyl ester, an aromatic carbonyl ester, an aromatic alkylcarbonyl ester, or the like of cellulose may be mentioned, and each of them may have a further substituted group. As preferred examples of these, a propyl group, a butyl group, a pentyl group, a hexyl group, a decyl group, a decyl group, a dodecyl fluorenyl group, a tridecyl fluorenyl group, and ten Tetraalkyl fluorenyl, hexadecane decyl, octadecyl fluorenyl, isobutyl decyl, tert-butyl fluorenyl, cyclohexanecarbonyl, oleoyl, benzhydryl, naphthalenecarbonyl, cinnamyl, and the like. Among these, a propyl fluorenyl group, a butyl decyl group, a dodecyl fluorenyl group, an octadecyl fluorenyl group, a tert-butyl fluorenyl group, an oil fluorenyl group, a benzamidine group, a naphthylcarbonyl group, a cinnamyl group, etc. It is especially preferred.

(solvent)

Examples of the solvent 112 for preparing the dope include aromatic hydrocarbons (for example, benzene, toluene, etc.), halogenated hydrocarbons (for example, di-methane, chlorobenzene, etc.), and alcohols (for example, methanol, ethanol, n-propanol, and positive). 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.) Wait.

Among the above halogenated hydrocarbons, a halogenated hydrocarbon having 1 to 7 carbon atoms is preferably used, and dichloromethane is most preferred. From the viewpoint of the solubility of the cellulose halide, the peelability of the cast film from the support, the mechanical strength of the film, and the optical properties, one or several kinds of carbon atoms of 1 to 5 are mixed in addition to dichloromethane. The alcohol is preferred. The content of the alcohol is preferably 2 to 25% by mass based on the entire solvent, more preferably 5 to 20% by mass. The alcohol may, for example, be methanol, ethanol, n-propanol, isopropanol or n-butanol, but methanol, ethanol, n-butanol or a mixture thereof is preferred.

Recently, the solvent composition which does not use dichloromethane has also been studied for the purpose of minimizing the influence on the environment. In this case, it is preferred to use an ether having 4 to 12 carbon atoms, a ketone having 3 to 12 carbon atoms, an ester having 3 to 12 carbon atoms, and an alcohol having 1 to 12 carbon atoms. sometimes These are also mixed as appropriate for use. For example, a mixed solvent of methyl acetate, acetone, ethanol, and n-butanol can be mentioned. These ethers, ketones, esters and alcohols may be those having a cyclic structure. Further, a compound having two or more functional groups of an ether, a ketone, an ester, and an alcohol (that is, -O-, -CO-, -COO-, and -OH) can also be used as a solvent.

[Examples]

In the following, in order to confirm the effects of the present invention, Experiments 1 to 5 were carried out. The details of each experiment are explained by Experiment 1, and the experiments 2 to 5 only show conditions different from Experiment 1.

(Experiment 1)

In the belt manufacturing apparatus 10, the first belt (hereinafter referred to as belt A) is produced from the side member 11 made of SUS316 and the center member 12 made of SUS316. The side members have a width of 150 mm and the central member has a width of 2000 mm. The respective widths of the welding bead 72 and the heat-affected zone 73 visually confirmed were measured. The width of the welding bead 72 is 2 mm, and the width of the heat-affected zone 73 is 4 mm.

In the welded portion of the belt A, the number of pinholes having a diameter of 50 μm or more and 70 μm or less is five per metre in the longitudinal direction and one or less per mm in the longitudinal direction. Further, there is no pinhole having a diameter of 70 μm or more.

(Method of measuring pinhole)

The number of pinholes in the welded portion was counted by visual observation. Further, the diameter of the pinhole confirmed by visual observation was measured by a fiber type observer.

In the solution film forming apparatus 110 (refer to FIG. 10), the film 116 is produced from a dope 113 containing cellulose diacetate (DAC) and a solvent. Use belt A As the belt 91. The belt 91 has a moving speed of 40 meters per minute. The casting die 133 continuously flows out of the dope 113 to the belt 91 in the moving state. A casting film 136 composed of a dope 113 is formed on the surface 91a of the belt 91.

The solvent is evaporated from the casting film 136 on the belt 91 by the dry air from the respective conduits 141 to 143. The temperature of the dry air from the first duct 141 was 130 ° C, the temperature of the dry air from the second duct 142 was 130 ° C, and the temperature of the dry wind from the third duct 143 was 70 °C. Further, drying of the casting film 136 by the inner heating portion 144 is not performed.

The peeling roller 135 peels the casting film 136 from the belt 91 and serves as the film 116. When the strip 91 is peeled off from the belt 91, the solvent content of the portion on the inner side in the width direction of the welded portion 91w is 45 mass% DB, and the portion of the cast film 136 in the welded portion 91w and the side portion 91s The solvent content rate was 45% by mass of DB. The film 116 is sequentially sent to the first tenter 120, the roll drying device 124, the second tenter 125, and the slitter 126.

(Experiment 2)

A film 116 was produced in the same manner as in Experiment 1 except that the tape B was used instead of the tape A. The belt B is the same as the belt A except for the number of needle holes or the diameter in the welded portion. In the welded portion of the belt B, the number of pinholes having a diameter of 50 μm or more and 70 μm or less is six in the longitudinal direction and two or less per mm in the longitudinal direction. Further, there is no pinhole having a diameter of 70 μm or more.

(Experiment 3)

A film 116 was produced in the same manner as in Experiment 1 except that the tape C was used instead of the tape A. Belt C except for the number of pinholes or diameter in the welded part Other than belt A. In the welded portion of the belt C, the number of pinholes having a diameter of 50 μm or more and 70 μm or less is six in the longitudinal direction and two or less per 2 mm in the longitudinal direction. The number of pinholes having a diameter of 75 μm or more is one in the whole.

(Experiment 4)

Use belt B instead of belt A. The moving speed of the belt 91 was set to 70 meters/minute. The casting film 136 is dried by the inner heating portion 144 provided at a position where the transmission belt 91 is opposed to the third conduit 143. The heated air having a temperature of 50 ° C is blown onto the casting film 136 by the inner heating portion 144. Except for the above, the film 116 was produced in the same manner as in Experiment 1. In addition, when the strip 91 is peeled off from the belt 91, the solvent content of the portion in the width direction of the welded portion 91w is 70% by mass DB, and the welded portion 91w and the portion on the side portion 91s of the cast film 136. The solvent content of the serving was 60% by mass of DB.

(Experiment 5)

Use belt B instead of belt A. The moving speed of the belt 91 was set to 70 meters/minute. Except for the above, the film 116 was produced in the same manner as in Experiment 1. In addition, when the strip 91 is peeled off from the belt 91, the solvent content of the portion in the width direction of the welded portion 91w is 70% by mass DB, and the welded portion 91w and the portion on the side portion 91s of the cast film 136. The solvent content of the serving was 70% by mass of DB.

(residual evaluation)

Experiments 1 to 5 were evaluated for the presence or absence of residue. No residue was produced in Experiments 1 and 4. A slight residue was produced in Experiment 2. Experiments 3 and 5 There is a significant residue in it.

91, A, B, C‧‧‧

91a‧‧‧ surface

91b‧‧‧ inside

91s‧‧‧ side

91c‧‧‧Central Department

91w‧‧‧Weld Department

110‧‧‧solution film making equipment

144‧‧‧ inside heating department

150‧‧‧heating wind

151‧‧‧ nozzle

10‧‧‧With manufacturing equipment

11‧‧‧ side members

12‧‧‧Central components

13‧‧‧With components

16‧‧‧Send out

17‧‧‧Docking Department

18, 61‧‧‧ welding unit

19‧‧‧ heating department

20, 127‧‧‧Winding device

23‧‧‧1st delivery device

24‧‧‧2nd delivery device

11e, 12e‧‧‧ side edge

26‧‧‧1st roll

27‧‧‧2nd roller

28‧‧‧3rd roller

29‧‧‧4th roller

Pc‧‧‧ docking position

Y‧‧‧Width direction

32, 37, 50‧ ‧ ‧ displacement mechanism

33, 51‧‧‧ controller

34, 47‧‧‧ position detection means

X‧‧‧Transfer direction

θ 1, θ 2‧‧‧ corner

41‧‧‧welding support roller

42‧‧‧ welding equipment

43‧‧‧Laser oscillator

46‧‧‧ welding device body

Ps‧‧‧Contact location

Room 52‧‧

55‧‧‧ cleaning device

Pw‧‧‧ welding position

13w‧‧‧Weld Department

56‧‧‧ catheter

57‧‧‧Air blower

62‧‧‧ Pressing device

63‧‧‧1st conveyor belt

64‧‧‧2nd conveyor belt

67‧‧‧5th roller

68‧‧‧6th roller

69‧‧‧7th roller

13s‧‧‧ side

13c‧‧‧Central Department

D1‧‧‧Interval between the 1st conveyor belt and the 2nd conveyor belt

D2‧‧‧Distance position and distance from the 1st conveyor belt

D3‧‧‧Distance position and distance from the 2nd conveyor belt

72‧‧‧ welding beads

73‧‧‧ Heat affected zone

D4‧‧‧Width of the passage area of the high heat conduction section

76‧‧‧ slots

D5‧‧‧ slot width

Depth of D6‧‧‧ trough

81‧‧‧Conical roller

D‧‧‧diameter of tapered roller

82‧‧‧ Drive means

85‧‧‧ clip

86‧‧‧ Clip body

87‧‧‧挟 Holding needle

88‧‧‧displacement mechanism

117‧‧‧film forming device

120‧‧‧1st tenter

124‧‧‧Roll drying device

125‧‧‧2nd tenter

126‧‧‧ slitting machine

111‧‧‧ Cellulose Telluride

112‧‧‧Solvent

113‧‧‧Liquor

116‧‧‧ film

119‧‧‧Retention means

131, 132, 147, 165‧‧ ‧ rolls

133, 136‧‧‧casting mode

135‧‧‧ peeling roller

133a‧‧‧Export

141‧‧‧1st catheter

142‧‧‧2nd catheter

143‧‧‧3rd catheter

155‧‧‧ catheter

157‧‧‧ catheter

170‧‧‧wind shield

The above objects and advantages will be readily understood by those skilled in the art in the <RTIgt;

Fig. 1 is a side view showing an outline of a belt manufacturing apparatus of the present invention.

Fig. 2 is a plan view showing an outline of a belt manufacturing apparatus.

Fig. 3 is a side view showing an outline of a welding unit.

4 is a plan view showing an outline of a welding unit.

Figure 5 is an end view taken along the line V-V of Figure 4 .

Fig. 6 is an explanatory view of a welding bead and its periphery.

Fig. 7 is a schematic view of a tapered roller.

Fig. 8 is a schematic view of a clip.

Fig. 9 is a schematic view of a belt.

Fig. 10 is a side view showing an outline of a first solution film forming apparatus.

Fig. 11 is a plan view showing an outline of a belt.

Fig. 12 is a perspective view showing an outline of a heating unit inside.

Fig. 13 is a cross-sectional view showing a state in which the inner heating portion heats the welded portion.

Fig. 14 is a side view showing an outline of a second solution film forming apparatus.

Fig. 15 is a side view showing an outline of a third solution film forming apparatus.

151‧‧‧ nozzle

150‧‧‧heating wind

91‧‧‧With

91b‧‧‧ inside

91a‧‧‧ surface

91s‧‧‧ side

91w‧‧‧Weld Department

91c‧‧‧Central Department

136‧‧‧cast film

Claims (7)

A method for forming a solution film, comprising the steps of: forming a film by welding a side member and a center member, and continuously flowing the dope containing the polymer and the solvent to have a moving direction of the moving belt; a surface of the moving belt exposed by the upper extending welded portion forms a casting film for covering the welded portion composed of the doped liquid on the surface; and a film drying step of blowing dry air to the casting film and causing a solvent Evaporating from the casting film; a peeling step of peeling the cast film from the moving belt as a wet film; and a film drying step of evaporating a solvent from the wet film; wherein the film forming step and the peeling are performed A welding portion heating step of heating the welded portion from the back side of the moving belt is performed between the steps. The solution film forming method according to the first aspect of the invention, wherein the soldering portion heating step is performed on the cast film having a solvent content of 30% by mass D.B. or more and 100% by mass or less of D.B. A drying device for evaporating the solvent from a film formed on a surface of a moving belt and comprising a dope comprising a polymer and a solvent, characterized in that the moving belt is welded by the side member and the central member a welded portion extending in the moving direction and exposed on the surface is covered by the film; and There is provided an inner heating portion that heats the welded portion from the back side of the moving belt. The drying device according to claim 3, wherein the inner heating portion includes a nozzle that blows heated air to the welded portion. The drying device according to claim 3, wherein the drying device is provided with a dry air supply unit that blows dry air to the film. The drying device according to claim 3, wherein the moving belt is formed in a ring shape and is cyclically moved in a state of being hung on the roller, and is sequentially disposed from the upstream side in the moving direction. a casting die and a peeling roll, wherein the casting die flows out the dope to the surface, the peeling roller peels the casting film from the surface, and the inner heating portion is disposed in the casting die and the aforementioned Between the peeling rolls. The drying device according to claim 3, wherein the welded portion has a pinhole having a diameter of 50 μm or more and less than 70 μm.