JP2011201089A - Tenter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tenter device stretching a film while suppressing dispersion of a slow axis of the film.SOLUTION: The clip tenter includes a rail and a clip. The rail used as a pair is disposed on each side of a carrying path 20r of the film. The clip 22 is movable along the rail. A moving route 22r of the clip 22 is formed along each rail 23. A partition plate 40 used as a pair is disposed on the center side in Z2 direction of each moving route 22r. A heating air head is provided inside the paired partition plates 40 to expose the film 12 to heating air, and a cooling air head is provided outside the paired partition plates 40 to expose the film 12 to cooling air.

Description

  The present invention relates to a tenter device.

  BACKGROUND ART A thermoplastic film having light permeability (hereinafter referred to as a film) is lightweight and easy to mold, and thus is widely used as an optical film. Among them, cellulose ester films using cellulose acylate and the like are used for retardation films which are constituent members of liquid crystal display devices whose market is expanding in recent years, including photographic photosensitive films.

  The main production methods of the film include a melt extrusion method and a solution casting method. The melt extrusion method is a method of producing a film by melting a polymer and then extruding it with an extruder, and has features such as high productivity and relatively low equipment cost. On the other hand, in the solution casting method, a polymer solution containing a polymer and a solvent (hereinafter referred to as a dope) is flowed to form a cast film on the support. Next, after the cast film becomes transportable, it is peeled from the support to form a wet film. Then, the solvent is evaporated from the wet film to form a film.

  In order to improve the flatness of the obtained film or to adjust the optical properties of the film, a tenter device for stretching the film in a predetermined direction is known (for example, Patent Document 1). This tenter device is provided on both sides of the belt-like film in the width direction, a pair of rails whose distance increases in the longitudinal direction, a chain movable along the rail, and a clip attached to the chain at a predetermined distance And have. And according to this tenter apparatus, the extending | stretching process which expands the width | variety of a film can be performed by hold | gripping the width direction both ends of a film using a clip, and running a chain along a rail.

  In addition, when the film is stretched, the direction of the slow axis varies due to the bowing phenomenon. Here, the bowing refers to a behavior in which a line segment drawn in the width direction in the film before the stretching treatment is deformed into a concave shape or a convex shape in the longitudinal direction of the film in the film after the stretching treatment. Therefore, as means for preventing the occurrence of the bowing phenomenon, (1) the temperature at the film edge is made higher than the film center, (2) the residual solvent amount at the film edge is made larger than the film center, (3) tenter. A method has been proposed in which zones having different temperatures are provided in a dryer (for example, Patent Document 2).

JP-A-11-90943 JP 2002-296422 A

  However, as shown in FIG. 11, the bowing phenomenon that occurs in the film 200 does not occur uniformly in the entire region of the film. The trend is different between the bow B1 generated in the portion 203 gripped by the paired clip 201 and the bow B2 generated in the portion 204 not gripped by the paired clip 201. When Boeing B1 and B2 having different tendencies occur in the same film 200, variations in the slow axis in the longitudinal direction of the finally obtained film occur.

  The variation in the slow axis due to the bowing described above becomes a factor that inhibits the contrast of the liquid crystal display device. In the field of liquid crystal display devices in which the VA method is mainstream and the size is increasing, the front contrast required for the liquid crystal display device is increasing day by day. Under these circumstances, manufacturers of liquid crystal display devices have been required to further improve the variation of the slow axis.

  This invention solves such a subject, and it aims at providing the tenter apparatus which extends | stretches a film, suppressing the dispersion | variation in the slow axis of a film.

  The tenter device of the present invention is a transport path for transporting a web in the longitudinal direction, and is arranged in the longitudinal direction of the web as a pair on both sides of the transport path, and grips both ends in the width direction of the web The width direction both ends so as to be close to the web comprising a pair, clip pair moving means for moving the clip pair in the longitudinal direction, and the width direction both ends and a product portion between the width direction both ends And a wind-shielding means that is provided on the boundary of the product part and divides the conveyance path into three sections of a central section, a first end section, and a second end section in the width direction, and provided in the central section, It has heating air supply means for applying heating air to the web.

  It is preferable to have cooling air supply means that is provided in the first end section and the second end section and applies cooling air to the web.

  The tenter device of the present invention is a transport path for transporting a web in the longitudinal direction, and is arranged in the longitudinal direction of the web as a pair on both sides of the transport path, and grips both ends in the width direction of the web A pair, a clip pair moving means for moving the clip pair in the longitudinal direction, a heating air supply means for uniformly sending the heating air toward the web in the width direction, and the heating air supply means and the clip And a wind shield member that is provided between the movement paths and blocks the heating air.

  It is preferable that the wind-shielding member is disposed so as to cover the moving path of the clip. It is preferable that cooling air supply means for applying cooling air to the web is disposed in the cover.

  Stretching step using a clip tenter having a pair of clips that are arranged in the longitudinal direction of the web in pairs along both sides of the conveyance path and grips both ends in the width direction of the web. When the above is performed, the deformation behavior is different between the first part gripped by the clip pair and the second part not gripped by the clip pair, of both ends of the web. According to the present invention, the temperature at both ends of the web can be lowered as compared with the central portion of the web, so that the deformation behavior in the first portion and the second portion can be made the same. The bowing generated in the first portion and the second portion can be made to have the same tendency. Therefore, according to the present invention, variations in the slow axis in the longitudinal direction of the finally obtained film can be suppressed.

It is explanatory drawing which shows the outline | summary of a film extending | stretching installation. It is a top view which shows the outline | summary of a 1st clip tenter. It is a perspective view which shows the outline | summary of a clip. It is explanatory drawing which shows the outline | summary of the flapper of a holding position. It is explanatory drawing which shows the outline | summary of the flapper of a separation position. It is a top view which shows the outline | summary of a 1st clip tenter. It is a top view which shows the outline | summary of the 2nd clip tenter. It is explanatory drawing which shows the outline | summary of the flapper of the holding | grip position provided in the 2nd clip tenter. It is explanatory drawing which shows the outline | summary of the flapper of the holding | grip position provided in the 3rd clip tenter. It is explanatory drawing which shows the outline | summary of solution casting apparatus. It is explanatory drawing which shows the outline | summary of the bowing which generate | occur | produces in a film in the conventional extending process.

  As shown in FIG. 1, the film stretching facility 10 performs a stretching process on a film supply unit 14 that feeds a strip-shaped film 12 in the longitudinal direction (hereinafter referred to as Z1 direction) and the film 12 that is fed from the film supply unit 14. A clip tenter 15 is provided, and a winding chamber 16 for winding the film 12 fed from the clip tenter 15 around a winding core 16a.

(Clip tenter)
As shown in FIG. 2, the clip tenter 15 has a casing 20. The casing 20 is provided with an inlet 20i and an outlet 20o. In the casing 20, a conveyance path 20r for conveying the film 12 in the Z1 direction is formed from the inlet 20i to the outlet 20o. Furthermore, the inside of the casing 20 is partitioned into a preheating area 20a, a stretching area 20b, a relaxation area 20c, and a cooling area 20d in order from the upstream side in the Z1 direction. The relaxation area 20c and the cooling area 20d may be omitted.

  The tenter body built in the casing 20 includes a clip 22 and a rail 23. The pair of rails 23 are installed on both sides of the transport path 20r of the film 12 over the areas 20a to 20d. The distance between the rails 23 in the extension area 20b increases from the upstream side toward the downstream side in the Z1 direction. On the other hand, the interval between the rails 23 in the relaxation area 20c becomes narrower from the upstream side toward the downstream side in the Z1 direction. Further, the interval between the rails 23 in the preheating area 20a and the cooling area 20d is constant.

  Sprockets 24 and 25 are provided on the upstream side and the downstream side of the rail 23 in the Z1 direction. An annular chain (not shown) meshes with the sprockets 24 and 25 and is attached so as to be movable along the rail 23. A plurality of clips 22 are attached to the chain at predetermined intervals. In FIG. 2, only a part of the clip 22 is shown in order to avoid complication of the drawing. As the sprockets 24 and 25 rotate, the clip 22 moves along the rail 23. Thus, the moving path 22r of the clip 22 is formed at both ends in the Z2 direction of the transport path 20r of the film 12. A clip opener 28 that contacts a part of the clip 22 is provided on the rail 23 in the preheating area 20a and on the rail 23 in the cooling area 20d.

  As shown in FIGS. 3 and 4, the clip 22 includes a clip body 30 and a rail attachment portion 31. The clip body 30 includes a substantially U-shaped frame 33, a flapper 34, and a rotation shaft 35. The flapper 34 is rotatably attached to the frame 33 by a rotation shaft 35.

  As shown in FIG. 4, the frame 33 includes a support surface 33 a that supports the back surface 12 b of both edges (hereinafter referred to as “ear portions”) 12 e of the film 12 in the Z2 direction. The support surface 33a is preferably flat.

  One end of the flapper 34 is provided with a pressing surface 34 a that can contact the surface 12 f of the ear 12 e of the film 12. At the other end of the flapper 34, an engagement head 34b that can engage with the clip opener 28 is provided. The pressing surface 34 a and the engaging head 34 b are swingable about the rotation shaft 35. Thus, the flapper 34 is located between a gripping position where the pressing surface 34a is in contact with the film 12 supported by the support surface 33a and a separation position (see FIG. 5) where the pressing surface 34a is separated from the film 12 supported by the support surface 33a. Can be freely rotated. In addition, it is preferable that the flapper 34 is urged so as to be in the gripping position.

  As the flapper 34 in the separation position moves toward the gripping position, the clearance between the pressing surface 34a and the support surface 33a gradually decreases. The clearance between the pressing surface 34a and the support surface 33a when the flapper 34 reaches the gripping position is smaller than the thickness of the film 12 to be gripped. Thus, when the flapper 34 is displaced to the gripping position, the pressing surface 34a presses the ear portion 12e of the film 12 supported by the support surface 33a. As a result, the clip 22 can grip the ear portion 12 e of the film 12. In addition, it is preferable that the shape of the pressing surface 34a is circular arc shape in the surface orthogonal to the rocking axis.

  When the flapper 34 is displaced from the separation position to the gripping position, the flapper 34 is preferably rotated so that the pressing surface 34a is directed from the end toward the center in the Z2 direction. As a result, even if the film 12 held by the clip 22 slips to the Z2 direction center, the pressing surface 34a moves to the Z2 direction center as the film 12 slides. As a result, the pressing surface 34a and the support surface 33a As a result, the gripping force of the film 12 increases. For this reason, the film 12 can be reliably held.

  As shown in FIGS. 4 and 6, a partition plate 40 in an upright posture with respect to the film 12 is provided along the movement path 22r closer to the center in the Z2 direction than the movement paths 22r. Furthermore, the partition plate 40 is disposed so as to be close to the transport path 20r. In the Z2 direction, the two partition plates 40 divide the conveyance path 20r of the film 12 into three sections, a central section 20rc, a first end section 20re, and a second end section 20rf.

  The partition plate 40 may be provided below the conveyance path 20r of the film 12, or may be provided both above and below the conveyance path 20r of the film 12. Moreover, in FIG. 4, although the area which provides the partition plate 40 was made into all the areas 20a-20d, this invention is not restricted to this, At least any one of the extension area 20b and the relaxation area 20c may be sufficient.

  The central section 20 rc is provided with a heating air head 44 that applies heating air to the film 12. The heating air head 44 is arranged in the Z1 direction in each of the areas 20a to 20d. The first end section 20re and the second end section 20rf are provided with cooling air heads 45 that apply cooling air to the film 12, respectively. The cooling air heads 45 are arranged in the Z1 direction in each of the areas 20a to 20d. The heating air head 44 and the cooling air head 45 each have a plurality of nozzles. The nozzles are arranged so as to be arranged at a predetermined pitch in the Z1 direction. A slit-shaped opening communicating with the internal duct is provided at the tip of the nozzle. The opening is formed to extend long in the direction Z2. Note that in the heating air head 44 and the cooling air head 45, an outlet for sending a predetermined air and a suction port for sucking the air may be alternately provided in the Z2 direction.

  The heating air head 44 and the heating air head 44 may be provided below the conveyance path 20r of the film 12, or may be provided both above and below the conveyance path 20r of the film 12. The area in which the cooling air head 45 is provided is not limited to all of the areas 20a to 20d, and may be at least one of the extension area 20b and the relaxation area 20c.

  Returning to FIG. 1, an ear clip device 48 is provided between the clip tenter 15 and the winding chamber 16. The ear clip device 48 cuts off the ear portion 12 e of the film 12 sent from the clip tenter 15. The separated ear portion 12e is sent to a crusher (not shown) by air blowing, cut into small pieces, and reused as a raw material such as a dope.

  Next, the operation of the present invention will be described. As shown in FIG. 1, the film supply unit 14 supplies the film 12 to the clip tenter 15. As shown in FIG. 2, the plurality of clips 22 move along the rail 23 by the movement of the chain. As a result, the clip 22 sequentially passes through the preheating area 20a, the extending area 20b, the relaxation area 20c, and the cooling area 20d, and then returns to the preheating area 20a again. As described above, the clip 22 circulates and moves through the areas 20a to 20d.

  In the preheating area 20a shown in FIG. 3, when the engaging head 34b comes into contact with the clip opener 28, the flapper 34 is in the separated position as shown in FIG. In this manner, the ear 12e of the film 12 introduced into the preheating area 20a is supported by the support surface 33a of the frame 33.

  As shown in FIG. 2, at the position Pa where the engagement head 34b is separated from the clip opener 28, the flapper 34 at the separation position (see FIG. 5) is in the gripping position (see FIG. 4). Thus, at the position Pa, the gripping of the ear portion 12e of the film 12 by the pressing surface 34a and the support surface 33a is started.

  Returning to FIG. 2, the clip 22 passes through the areas 20 a to 20 d while the flapper 34 remains in the gripping position. For this reason, the film 12 having the ear 12e held by the clip 22 passes through the areas 20a to 20d.

  The width of the film 12 in the preheating area 20a remains W1. The width of the film 12 in the stretching area 20b gradually increases from W1 to W2 toward the downstream side in the Z1 direction. The width of the film 12 in the relaxation area 20c gradually decreases from W2 to W3 as it goes downstream in the Z1 direction. The width of the film 12 in the cooling area 20d remains W3.

  In each of the areas 20a to 20d, as shown in FIG. 4, the heated air head 44 applies heated air adjusted to a predetermined temperature to the film 12. Since the partition plate 40 blocks the heated air from the heated air head 44, the product portion 12c between the pair of ear portions 12e in the film 12 is heated. In each of the areas 20a to 20d, the cooling air head 45 applies the cooling air adjusted to a predetermined temperature to the ears 12e of the film 12. Since the partition plate 40 blocks the cooling air from the cooling air head 45, the pair of ears 12e of the film 12 is cooled.

  In the stretching area 20b, the film 12 is stretched toward the Z2 direction end by the clip 22 that holds the ear 12e. Since the ear | edge part 12e of the film 12 is cooled uniformly in the Z1 direction at this time, the bowing which generate | occur | produces in the film 12 becomes uniform in the Z1 direction. Therefore, according to the present invention, variations in the slow axis in the Z1 direction can be suppressed.

  In the above embodiment, the cooling air head 45 is provided in the first end section 20re and the second end section 20rf, but the present invention is not limited to this, and the cooling air head 45 may be omitted.

(Preheating area)
The residual solvent amount of the film 12 introduced into the preheating area 20a is preferably 0% by weight or more and 60% by weight or less. Temperature _{Tf 20a} of the film 12 in the preheating area 20a is preferably less than the glass transition temperature Tg 80 ° C. or higher. In the present invention, the amount of the solvent remaining in the cast film and each film is shown on the basis of the dry amount as the residual solvent amount. Moreover, the measurement method takes a sample from the target film, and when the weight of this sample is x and the weight after drying the sample is y, it is calculated as {(xy) / y} × 100. .

(Extension area)
The residual solvent amount of the film 12 introduced into the stretching area 20b is preferably 0% by weight or more and 40% by weight or less. Of the stretching area 20b, the temperature Tf _20b of the film 12 in the central section 20rc is preferably 60 ° C. or higher and 180 ° C. or lower. In the stretching area 20b, the temperature of the film 12 in the first end section 20re and the second end section 20rf is preferably 40 ° C. or lower than the temperature Tf _20b . The stretching ratio ER (= W2 / W1) is preferably greater than 100% and 200% or less, for example.

(Relaxation area)
The residual solvent amount of the film 12 introduced into the relaxation area 20c is preferably 0% by weight to 30% by weight. In the relaxation area 20c, the temperature Tf _20c of the film 12 in the central section 20rc is preferably 70 ° C. or higher and 160 ° C. or lower. Of the relaxation area 20c, the temperature of the film 12 in the first end section 20re and the second end section 20rf is preferably lower by 20 ° C. than the temperature Tf _20c . The relaxation rate RR (= W3 / W2) is preferably greater than 90% and less than 100%, for example.

(Cooling area)
The residual solvent amount of the film 12 introduced into the cooling area 20d is preferably 0% by weight or more and 20% by weight or less. Moreover, it is preferable that temperature Tf 20d of the film 12 in the cooling area 20d is 40 _degreeC or more and 150 degrees C or less.

  A second embodiment of the present invention will be described. Hereinafter, the same members as those in the above embodiment are denoted by the same reference numerals, description thereof will be omitted, and only different components will be described.

  As shown in FIGS. 6 and 7, the heating air head 44 sends the heating air toward the entire area in the Z2 direction of the film 12 of the cover 60. A cover 60 that covers the moving path 22r of the clip 22 is provided in the casing 20. The cover 60 blocks the heated air toward the ear 12e of the film 12. In this way, the ears 12e of the film 12 are uniformly at a lower temperature than the product part 12c, so that the variation of the slow axis in the Z1 direction can be suppressed.

  A second cooling head 50 that applies cooling air to the ears 12 e of the film 12 may be provided inside the cover 60. The second cooling head 50 is preferably provided along the movement path 22r. Further, instead of the cover 60, a wind shield plate 65 may be provided between the moving path 22r and the heating air head 44 (see FIG. 9).

  The area where the second cooling head 50, the cover 60, and the wind shielding plate 65 are provided is not limited to all of the areas 20a to 20d, and may be at least one of the extension area 20b and the relaxation area 20c.

  Next, a film production facility using the clip tenter 15 will be described with reference to FIG. The solution casting apparatus 110 includes a casting chamber 112, a pin tenter 113, a clip tenter 15, a drying chamber 115, a cooling chamber 116, and a winding chamber 16. In the casting chamber 112, a casting die 121, a casting drum 122, a decompression chamber 123, and a peeling roller 124 are provided.

  The casting drum 122 is disposed so that the axial direction is horizontal, and is rotatable about the shaft. The casting drum 122 is rotated around a shaft by a driving device (not shown) under the control of the control unit. Due to the rotation of the casting drum 122, the peripheral surface of the casting drum 122 travels at a predetermined speed.

  A temperature control device 125 is connected to the casting drum 122. The temperature adjustment device 125 includes a temperature adjustment unit that adjusts the temperature of the heat transfer medium. The temperature control device 125 circulates the heat transfer medium adjusted to a desired temperature between the temperature adjusting unit and the flow path provided in the casting drum 122. By circulating the heat transfer medium, the temperature of the peripheral surface of the casting drum 122 can be maintained at a desired temperature.

(Casting die)
The casting die 121 is provided above the casting drum 122. The casting die 121 has a slit through which the dope 127 flows out at the tip. The casting die 121 is arranged so that the slit is close to the casting drum 122. The dope 127 that has flowed out of the casting die 121 is spread on the peripheral surface of the moving casting drum 122, thereby forming a belt-like casting film 128.

  The stripping roller 124 is disposed downstream of the casting die 121 in the A direction. The stripping roller 124 strips the casting film 128 formed on the peripheral surface and guides it as a wet film 130 to the downstream side of the casting chamber 112.

  The decompression chamber 123 is provided upstream of the casting die 121 in the A direction and downstream of the stripping roller 124 in the A direction. Under the control of a control unit (not shown), the decompression chamber 123 can decompress the upstream side of the casting bead so that the upstream pressure of the casting bead is lower than the downstream side.

  On the downstream side of the casting chamber 112, a pin tenter 113, a clip tenter 15, a drying chamber 115, a cooling chamber 116, and a winding chamber 16 are sequentially installed. In the transfer part 133 between the casting chamber 112 and the pin tenter 113, the belt-shaped wet film 130 fed out from the casting chamber 112 is conveyed to the pin tenter 113 using a plurality of rollers 134. The pin tenter 113 has a number of pin plates that pass through and hold the ears of the wet film 130. The pin plate moves on the track. Dry air is sent to the wet film 130 held on the pin plate, and the wet film 130 is dried to become the film 12.

  An ear clip device is provided downstream of the pin tenter 113 and the clip tenter 15, respectively. The ear clip devices 136a and 136b cut off the ears of the film 12. The separated ears are sent to a crusher (not shown) by air blowing, cut into small pieces, and reused as a raw material for dopes and the like.

  A large number of rollers 140 are provided in the drying chamber 115, and the film 12 is wound around and transported. The temperature and humidity of the atmosphere in the drying chamber 115 are adjusted by an air conditioner (not shown), and the film 12 is dried by passing through the drying chamber 115. An adsorption recovery device 141 is connected to the drying chamber 115. The adsorption recovery device 141 recovers the solvent evaporated from the film 12 by adsorption.

  In the cooling chamber 116, the film 12 is cooled until the temperature of the film 12 reaches substantially room temperature. Between the cooling chamber 116 and the winding chamber 16, a neutralizing bar 144 for performing static elimination treatment on the film 12 from the upstream side toward the downstream side in the Z1 direction, and a knurling for winding on the ear portion of the film 12. A knurling roller 145 is installed in order.

  Note that the clip tenter 15 may be provided between the drying chamber 115 and the cooling chamber 116.

  In the present invention, when flowing a dope, two or more types of dopes are simultaneously flowed to form a cast film having a plurality of layers made of individual dopes (hereinafter referred to as a laminated cast film). Alternatively, sequential lamination co-casting in which a plurality of dopes are sequentially flowed to form a laminated cast film can be performed. In addition, you may combine both casting. When simultaneous lamination and co-casting is performed, a casting die to which a feed block is attached may be used, or a multi-pocket casting die may be used.

  In the above embodiment, the casting film 128 is formed on the peripheral surface of the rotating casting drum 122. However, the present invention is not limited to this, and the casting film 128 may be formed on a circulating band that circulates. .

  In the above embodiment, the casting film 128 is cooled until the casting film 128 can be transported. However, the present invention is not limited to this, and the casting film 128 is cast until the casting film 128 can be transported. The solvent may be evaporated from the film 128. In this case, the residual solvent amount of the casting film 128 at the time of peeling is preferably 30% by weight or more and 120% by weight or less.

  The film 12 obtained by the present invention can be used particularly for a retardation film and a polarizing plate protective film.

  The width of the film 12 is preferably 600 mm or more, and more preferably 1400 mm or more and 2500 mm or less. The present invention is also effective when the width of the film 12 is greater than 2500 mm. Moreover, it is preferable that the film thickness of the film 12 is 30 micrometers or more and 120 micrometers or less.

  The in-plane retardation Re of the film 12 is preferably 20 nm or more and 300 nm or less, and the thickness direction retardation Rth of the film 12 is preferably −100 nm or more and 300 nm or less.

The method for measuring the in-plane retardation Re is as follows. In-plane retardation Re is a letter obtained by conditioning a sample film at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, and measuring it from the vertical direction at 632.8 nm with an automatic birefringence meter (KOBRA21DH Oji Scientific Co., Ltd.). The foundation value was used. Re is expressed by the following equation.
Re = | n1-n2 | × d
n1 is the refractive index of the slow axis, n2 is the refractive index of the fast axis 2, and d is the thickness (film thickness) of the film.

The measuring method of the thickness direction retardation Rth is as follows. The sample film was conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, and measured in the same manner while tilting the film surface with an ellipsometer (M150 manufactured by JASCO Corporation) measuring 632.8 nm from the vertical direction. It calculated according to the following formula from the extrapolated value of the retardation value.
Rth = {(n1 + n2) / 2−n3} × d
n3 represents the refractive index in the thickness direction.

  In the said embodiment, although this invention was used about the film manufactured with the solution casting apparatus, this invention can also be used about the film manufactured with the melt casting apparatus.

(polymer)
The polymer that can be used in the present invention is not particularly limited as long as it is a thermoplastic resin, and examples thereof include cellulose acylate, a lactone ring-containing polymer, a cyclic olefin, and polycarbonate. Of these, cellulose acylate and cyclic olefin are preferred, cellulose acylate containing an acetate group and propionate group, and cyclic olefin obtained by addition polymerization, more preferably cyclic olefin obtained by addition polymerization. It is.

(Cellulose acylate)
As the cellulose acylate, cellulose triacetate (TAC) is particularly preferable. Among the cellulose acylates, the substitution degree of the acyl group to the hydroxyl group of cellulose is represented by the following formulas (I) to (III), and A and B represent the substitution degree of the acyl group with respect to the hydrogen atom in the hydroxyl group of cellulose. , A is the degree of substitution of the acetyl group, and B is the degree of substitution of the acyl group having 3 to 22 carbon atoms. In addition, it is preferable that 90 weight% or more of TAC is a particle | grain of 0.1-4 mm. However, the polymer that can be used in the present invention is not limited to cellulose acylate.
(I) 2.0 ≦ A + B ≦ 3.0
(II) 0 ≦ A ≦ 3.0
(III) 0 ≦ B ≦ 2.9

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by esterifying some or all of these hydroxyl groups with an acyl group having 2 or more carbon atoms. The degree of acyl substitution means the ratio at which the hydroxyl group of cellulose is esterified at each of the 2-position, 3-position and 6-position (the substitution degree is 1 in the case of 100% esterification).

  The total degree of acylation substitution, that is, the value of DS2 + DS3 + DS6 is preferably 2.00 to 3.00, more preferably 2.22 to 2.90, and particularly preferably 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. Here, DS2 is a ratio in which the hydrogen of the hydroxyl group at the 2-position in the glucose unit is substituted by an acyl group (hereinafter referred to as “acyl substitution degree at the 2-position”), and DS3 is the hydroxyl group at the 3-position in the glucose unit. The hydrogen is substituted with an acyl group (hereinafter referred to as “acyl substitution degree at the 3-position”), and DS6 is the ratio of the hydrogen at the 6-position hydroxyl group substituted with an acyl group (hereinafter referred to as “acyl substitution degree at the 3-position”). "The 6-position acyl substitution degree").

  Only one type of acyl group may be used in the cellulose acylate of the present invention, or two or more types of acyl groups may be used. When two or more kinds of acyl groups are used, it is preferable that one of them is an acetyl group. The sum of the degree of substitution of hydroxyl groups at the 2nd, 3rd and 6th positions by acetyl groups is DSA, and the sum of the degree of substitution of the hydroxyl groups at the 2nd, 3rd and 6th positions by acyl groups other than acetyl groups When DSB is DSB, the value of DSA + DSB is preferably 2.22 to 2.90, and particularly preferably 2.40 to 2.88.

  The DSB is preferably 0.30 or more, particularly preferably 0.7 or more. Further, 20% or more of DSB is preferably a substituent of a hydroxyl group at the 6-position, more preferably 25% or more, further preferably 30% or more, and particularly preferably 33% or more. Further, the DSA + DSB value at the 6-position of the cellulose acylate is 0.75 or more, more preferably 0.80 or more, and particularly preferably cellulose acylate of 0.85 or more. By using it, a dope with better solubility can be produced. In particular, when a non-chlorine organic solvent is used, a dope having excellent solubility, low viscosity and excellent filterability can be produced.

  Cellulose, which is a raw material for cellulose acylate, may be obtained from either linter or pulp.

  The acyl group having 2 or more carbon atoms of cellulose acylate in the present invention may be an aliphatic group or an aryl group, and is not particularly limited. For example, cellulose alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkylcarbonyl ester and the like may be mentioned, and each may further have a substituted group. Preferred examples of these include propionyl group, butanoyl group, pentanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, iso-butanoyl group , T-butanoyl group, cyclohexanecarbonyl group, olenoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like. Among these, a propionyl group, a butanoyl group, a dodecanoyl group, an octadecanoyl group, a t-butanoyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, a cinnamoyl group, and the like are more preferable, and a propionyl group and a butanoyl group are particularly preferable. It is.

(solvent)
Solvents for preparing the dope include aromatic hydrocarbons (eg, benzene, toluene, etc.), halogenated hydrocarbons (eg, dichloromethane, chlorobenzene, etc.), alcohols (eg, methanol, ethanol, n-propanol, n-butanol, Diethylene glycol, etc.), ketones (eg, acetone, methyl ethyl ketone, etc.), esters (eg, methyl acetate, ethyl acetate, propyl acetate, etc.) and ethers (eg, tetrahydrofuran, methyl cellosolve, etc.).

  Among the above halogenated hydrocarbons, halogenated hydrocarbons having 1 to 7 carbon atoms are preferably used, and dichloromethane is most preferably used. From the viewpoint of physical properties such as solubility of TAC, peelability of cast film from the support, mechanical strength and optical properties of the film, one or several kinds of alcohols having 1 to 5 carbon atoms are mixed in addition to dichloromethane. It is preferable. The content of alcohol is preferably 2 to 25% by weight, more preferably 5 to 20% by weight, based on the entire solvent. Examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, and n-butanol, but methanol, ethanol, n-butanol, or a mixture thereof is preferably used.

  Recently, a solvent composition not using dichloromethane has been studied for the purpose of minimizing the influence on the environment. In this case, 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 are preferable. Sometimes used. For example, a mixed solvent of methyl acetate, acetone, ethanol, and n-butanol can be mentioned. These ethers, ketones, esters and alcohols may have a cyclic structure. A compound having two or more functional groups of ether, ketone, ester, and alcohol (that is, —O—, —CO—, —COO—, and —OH) can also be used as the solvent.

  Details of cellulose acylate are described in paragraphs [0140] to [0195] of JP-A-2005-104148, and these descriptions can also be applied to the present invention. The same applies to additives such as solvents and plasticizers, deterioration inhibitors, UV absorbers (UV agents), optical anisotropy control agents, retardation control agents, dyes, matting agents, release agents and release accelerators. JP-A-2005-104148 describes in detail in paragraphs [0196] to [0516], and these descriptions can also be applied to the present invention.

10 Film Stretching Equipment 12 Film 15 Clip Tenter 40 Partition Plate 44 Heating Air Head 45 Cooling Air Head

Claims (5)

A transport path for transporting the web in the longitudinal direction, paired on both sides of the transport path, arranged in the longitudinal direction of the web, and a pair of clips for gripping both ends in the width direction of the web;
Clip pair moving means for moving the clip pair in the longitudinal direction;
Provided on the boundary between the width direction both ends and the product portion so as to be close to the web including the width direction both ends and the product portion between the width direction both ends, and the conveyance path in the width direction. Wind shielding means that divides into a central section, a first end section, and a second end section;
A tenter device provided with heating air supply means provided in the central section and for applying heating air to the web.   The tenter device according to claim 1, further comprising a cooling air supply unit that is provided in the first end section and the second end section and applies cooling air to the web. A transport path for transporting the web in the longitudinal direction, paired on both sides of the transport path, arranged in the longitudinal direction of the web, and a pair of clips for gripping both ends in the width direction of the web;
Clip pair moving means for moving the clip pair in the longitudinal direction;
Heating air supply means for uniformly sending the heating air toward the web in the width direction;
A tenter device comprising a heating air supply member and a wind shielding member provided between the heating air supply means and the moving path of the clip, for blocking the heating air.   The tenter device according to claim 3, wherein the wind-shielding member is disposed so as to cover a moving path of the clip.   5. The tenter device according to claim 4, wherein cooling air supply means for applying cooling air to the web is disposed in the cover.

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