JP5292040B2 - Film stretching apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably stretch a film by preventing the occurrence of uneven orientation caused by a detective grip or a biting miss. <P>SOLUTION: An upper guide plate 51 and a lower guide plate 52 are installed on the side of a film inlet 37. The upper guide plate 51 is arranged to be positioned on the upper side of the film 3, the lower guide plate 52 is arranged to be positioned on the lower side of the film 3, and the film 3 is inserted between the upper guide plate 51 and the lower guide plate 52. When the film 3 is inserted between the guide plates 51 and 52, the lug elongation of a marginal part 3a is corrected. The flattened film 3 with the lug elongation of the marginal part 3a corrected, while the marginal part 3a is guided surely between a plinth 31b and a flapper lower surface 32a, is gripped surely with a clip 30 without a biting miss. The film 3 gripped surely with the clip 30 is stretched stably with a tenter 5. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a film stretching apparatus and method for transporting and stretching while gripping both side edges of the film in the width direction.

  In recent years, due to the rapid development and spread of liquid crystal displays and the like, the demand for cellulose acylate films, particularly triacetyl cellulose films (TAC films) used as protective films for these liquid crystal displays is increasing. With this increase in demand, improvement in productivity is desired. The TAC film is supported by casting a dope containing a TAC and a solvent on a continuously running support using a casting die, and providing the casting film with self-supporting property by drying or cooling. It is manufactured by peeling off from the body, drying and winding up. In such a solution casting method, a film having no foreign matter and excellent optical characteristics can be obtained as compared with a film forming method by melt extrusion.

As a method for adjusting the optical characteristics of the film, particularly the retardation, stretching using a tenter is performed. In the tenter, a gripping member such as a clip that travels along the left and right guide rails at the same speed preheats the film while gripping and moving both side edges of the film, and extends in the width direction after preheating. The clip grips the film placed on the frame with a flapper that opens and closes. In the case of a soft film with a large amount of residual solvent, the film may be torn when the flapper is closed at the grip start position. is there. Therefore, Patent Document 1 proposes a solution casting method capable of reliably gripping a soft film having a large amount of residual solvent.
JP 2005-81785 A

  By the way, when the thickness of both side edges of the film becomes thin during film formation, stress is concentrated on the both side edges where the thickness is thin due to the tension action during transport, and the both edges become thin and the film transport direction. A phenomenon called “ear extension” occurs. Thus, since extra length is generated at both side edges of the film that should be a flat surface, uneven deformation occurs in the film transport direction at a cycle of about 100 to 300 mm, resulting in an ear extension as shown in FIG.

  Such an ear extension phenomenon may occur not only at the time of film formation but also by knurling when the film is wound into a roll. In the knurling process, when the film is wound into a roll form, minute irregularities are formed on both side edges of the film by knurling or the like in order to prevent winding deviation. In the film subjected to the knurling treatment as described above, the side edges are slightly thicker due to minute unevenness as compared with the central portion in the film width direction. When this film is wound up in a roll form, at the end of winding, the winding diameter by the cumulative winding at the central portion and the ear portion is larger than that at the central portion. Due to the difference, ear elongation occurs in the ear.

  FIG. 7 shows an example of this ear extension, and both side edge portions 100a of the film 100 are pleated by the extension of the ear, and the uneven deformation amount in the film thickness direction is increased. When the uneven deformation amount increases, the film 100 is composed of a frame having a pedestal and a flapper swingably attached to the frame, and a tenter using a clip that grips the film between the pedestal and the flapper. When the flapper swings so as to sandwich the both side edges 100a when the two sides are stretched, wrinkles may be generated on both side edges 100a due to an impact when the swinging flapper collides with both side edges 100a. When wrinkles are generated at both side edges 100a, the flapper kicks out both side edges 100a when gripping both side edges 100a with the adjacent clip, and both side edges 100a are displaced or dropped from the pedestal. In this case, there was a problem that the film 100 could not be stably stretched because the both side edges 100a were poorly gripped and disengaged by the flapper.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a film stretching apparatus and method that can stably stretch a film.

Film stretching apparatus of the present invention, a plurality of clips and gripping position for gripping the side edges, Ru are selectively set in an open position for opening the gripping of the side edges of the film, the running of the film A plurality of clips disposed on both sides of the path and moving in the running direction of the film; and a stretching device main body for stretching the film in the width direction; and a film inlet side of the stretching device main body, the film A first guide plate that is in contact with the lower surface of both side edge portions of the width direction and guides the both side edge portions to the clip at the open position, and is provided above the first guide plate, A second guide plate that positions both side edges in the width direction of the film in the gap therebetween and guides the both side edges to the clip in the open position, and the first guide plate and the second guide plate are By clip One end is positioned on the upstream side in the traveling path of the film started to film holding starting position gripping the serial film, the other end, characterized in that located downstream of said film holding starting position.

Moreover, it is preferable that the clearance gap between the said 1st guide plate and the 2nd guide plate is 2-30 mm .

  Furthermore, it is preferable to provide an ear-cut portion that cuts both side edges of the film held by the first guide plate and the second guide plate in the film running direction to separate the product portion and the ear portion.

  In addition, the first area that is disposed on the upstream side in the film running direction with respect to the first guide plate and the second guide plate and in which the side edges on both sides in the width direction of the film are in contact is the center in the width direction of the film. It is preferable to include a correction roller having a diameter larger than that of the second area, and a winding roller for winding a film around the correction roller.

  Further, in the winding roller, the first area where both side edges in the width direction of the film are in contact with each other is formed to have a larger diameter than the second area where the center portion in the width direction of the film is in contact. preferable.

  The clip includes a frame having a pedestal, a flapper that is swingably attached to the frame so as to grip the film between the pedestal, and the open position in which a tip of the flapper is separated from the pedestal. A coil spring that presses the tip of the flapper against the pedestal and urges the film at the gripping position in which the film is gripped by the tip of the flapper and the pedestal. It is preferable that a clip closer is provided in which the flapper is urged from the open position to the gripping position to grip both side edges of the film with the clip.

Further, the film stretching process of the present invention, a plurality of clips and gripping position for gripping the side edges, Ru are selectively set in an open position for opening the gripping of the side edges of the film, the film A stretching step of stretching the film in the width direction with a plurality of clips that are arranged on both sides of the traveling path of the film and moving in the traveling direction of the film, and the film gripping start position for starting the gripping of the film with the clips One end is located on the upstream side of the film travel path, and the other end is located on the downstream side of the film grip start position. Before gripping the film with the clip, both side edges in the width direction of the film in contact with a lower surface of the parts, a first guide plate for guiding the side edge portions to clip the open position, one end is positioned upstream of the film holding starting position The other end is arranged so as to be positioned downstream of said film holding starting position, by a second guide plate to position the widthwise side edges of the film into the gap between the first guide plate, the two side A guide step of guiding the edge portion to the clip in the open position.

  According to the present invention, the first guide plate and the second guide plate hold both side edges in the width direction of the film from above and below, and guide them to the clip waiting in the open position. The amount of unevenness in the film thickness direction can be reduced. Thereby, the side edge part of a film can be reliably guided to the clip of an open state. And since the unevenness | corrugation amount of a both-sides edge part is suppressed, a film will not be extruded at the front-end | tip of a flapper at the time of film holding, and the side edge part of a film can be hold | gripped reliably. Accordingly, it is possible to eliminate the occurrence of stretching unevenness due to poor gripping.

  As shown in FIG. 1, the offline stretching apparatus 2 stretches a TAC film 3 (hereinafter, film 3), a film supply chamber 4, a tenter (stretching apparatus body) 5, a thermal relaxation chamber 6, A cooling chamber 7 and a winding chamber 8 are provided, and these are arranged in order along the film transport direction A. In the film supply chamber 4, a film roll 9 manufactured by a solution casting apparatus is set. The film roll 9 is obtained by winding the film 3 around a core to form a roll. The film 3 is fed out from the film roll 9, and is stretched in the film width direction B while being heated by the tenter 5, and the stretched film 3 is wound with the temperature lowered through the thermal relaxation chamber 6 and the cooling chamber 7. It is wound up in the take-up chamber 8. In the tenter 5, the film 3 is stretched in the width direction at a predetermined ratio of 100.5% to 300%. In the film supply chamber 4, the tenter 5, the heat relaxation chamber 6, the cooling chamber 7, and the winding chamber 8, there is an EPC (edge position controller) (not shown) that performs control for suppressing the meandering of the film 3 and accurately conveying it. Is provided.

  The film supply chamber 4 includes a turret type film delivery device 10 and a joining portion 11. The film delivery apparatus 10 has a turret arm 13 provided with attachment shafts 12 at both ends. A film roll 9 is attached to each attachment shaft 12. The turret arm 13 rotates intermittently by 180 degrees, positions one attachment shaft 12 at the delivery position (on the joint 11 side), and positions the other attachment shaft 12 at the core replacement position. The film 3 is sent out from the film roll 9 mounted on the mounting shaft 12 at the sending position to the joint portion 11. When all the films 3 are sent out, the turret arm 13 rotates, the empty core is removed from the mounting shaft 12 located at the core replacement position, and a new film roll is mounted.

  In the joining portion 11, in order to continuously supply the film 3 to the tenter 5, the rear end portion of the film 3 sent out in advance is joined to the front end portion of the film 3 sent out following.

  A reservoir 16 is disposed between the film supply chamber 4 and the tenter 5, and this reservoir 16 forms a loop of the film 3 that is longer than the length necessary for the film bonding process. For this reason, since the film 3 stored in the reservoir 16 is sent out to the tenter 5 at the time of film bonding, the film 3 can be bonded without stopping the tenter 5.

  As shown in FIG. 2, the tenter 5 extends the film 3 in the film width direction B while transporting the film 3 in the film transport direction A, and includes a first rail 21, a second rail 22, and a first rail. The first chain 23 is guided by 21 and the second chain 24 is guided by the second rail 22.

  The first chain 23 is stretched between the driving sprocket 25 and the driven sprocket 26, and the second chain 24 is stretched between the driving sprocket 27 and the driven sprocket 28. Each driving sprocket 25, 27 is rotationally driven by a driving mechanism (not shown).

  A number of clips 30 are attached to the first chain 23 and the second chain 24 at regular intervals. These clips 30 extend along the film width direction B by moving along the rails 21 and 22 while gripping the side edges of the film 3. A point PA indicates a film grip start position of the clip 30, and a point PB indicates a film grip open position of the clip 30. Further, the point PC indicates the stretching start position by the clip 30, and the point PD indicates the stretching end position by the clip 30. By the stretching process, the film width of the film 3 is changed from Wa to Wb (> Wa). In addition, the draw ratio of the film 3 is appropriately changed according to desired optical characteristics and the like.

  The tenter 5 is divided into a preheating zone 5a, a stretching zone 5b, and a stretching relaxation zone 5c in the film transport direction A. In the preheating zone 5a, the film 3 is preheated, the distance between the pair of clips is not changed, and stretching in the film width direction B by the clip 30 is not performed. In the stretching zone 5 b, the film 3 is heated and the distance between the pair of clips gradually increases, and the film 3 is stretched in the film width direction B by the clip 30. In the stretching relaxation zone 5c, the distance between the pair of clips does not change or gradually decreases, and stretching relaxation (thermal relaxation) is performed.

  As shown in FIG. 3, the clip 30 includes a substantially U-shaped frame 31, a flapper 32, and a rail attachment portion 33. The flapper 32 is rotatably attached to the frame 31 by an attachment shaft 31a, and grips the film with the pedestal 31b of the frame 31. The first chain 23 or the second chain 24 is attached to the rail attachment portion 33. The flapper 32 is in a state where the flapper lower surface 32a is pressed against the pedestal 31b and the gripper 3 grips the film 3 by the flapper lower surface 32a and the pedestal 31b, and the engaging head 32b contacts the clip opener 35 and rotates obliquely. It is displaced between the open position and is normally biased in both directions by a coil spring (not shown) so as to be in either the gripping position or the open position.

  As shown in FIG. 2, at the film grip start position PA on the film entrance 37 side, the flapper 32 is pushed in the closing direction by the clip closer 36 having a conical surface as shown in FIG. After that, the gripping position is reached by the coil spring, and the side edge 3 a of the film 3 is gripped by the clip 30. Similarly, as shown in FIG. 2, in the film gripping open position PB on the film exit 38 side, the flapper 32 is pushed to the open position by the clip opener 35, so that the flapper 32 passes the dead point and is opened by the coil spring. Thus, the grip of the side edge 3a by the clip 30 is released.

  As shown in FIG. 4, on the film entrance 37 side, the film 3 is pulled between the correction roller 41 for correcting the ear elongation of the side edge 3a and the correction roller 41, and the film 3 is wound around the correction roller 41. An attaching roller 42 is provided. The rollers 41 and 42 are rotatably provided, the correction roller 41 is rotated by a motor 43, and the winding roller 42 is rotated by a motor 44. The correction roller 41 is disposed at a position where the length to the film grip start position PA is shorter than the width of the film 3. Thus, by arranging the correction roller 41 close to the film grip start position PA, it is possible to efficiently correct the ear extension.

  The lower surface of the film 3 is in contact with the correction roller 41, and the upper surface of the film 3 is in contact with the winding roller 42. As the rollers 41 and 42, metal rollers whose surfaces are buffed so as to have a surface roughness of 0.2 to 50S are used so as not to damage the film 3. As a material of the metal roller, an aluminum alloy (for example, A5056) or SUS304 subjected to hard chrome plating is used. The roller may be made of rubber, preferably having a hardness of 40 to 90 °, a surface roughness of 0.5 to 50S, a linear pressure of 10 to 100 N / m, and a hardness of 50 to 90 ° and a surface roughness. Is preferably 0.5 to 10 S and the linear pressure is preferably 10 to 50 N / m.

  The correction roller 41 includes a central shaft portion 41a and side edge shaft portions 41b connected to both ends of the central shaft portion 41a. The side edge shaft portion 41b has a larger diameter than the central shaft portion 41a. Yes. The central shaft portion 41 a contacts the central portion in the width direction of the film 3, and the side edge shaft portion 41 b contacts the side edge portion 3 a of the film 3. In addition, although the diameter and width | variety of the side edge axial part 41b can be changed suitably, it is preferable that the side edge axial part 41b is 0.2-8 mm larger diameter than the central axis part 41a, and 0.4- More preferably, the diameter is 4 mm.

  The film 3 is wound around the correction roller 41 by a winding roller 42, and the side edge portion 3a is wound around the side edge shaft portion 41b. Thereby, the path length of the side edge part 3a can be lengthened compared with the center part of the film 3, a wrinkle can be extended in the film conveyance direction A, and the side edge part 3a is planarized. Since the film 3 whose side edge 3a is flattened is securely gripped by the clip 30 without being disengaged, uneven stretching in the film transport direction A is eliminated. Further, like the straightening roller 41, the winding roller 42 may be formed of a stepped roller having a side edge portion larger in diameter than the center portion. In this case, by using straightening rollers at the top and bottom, the path length of the side edge 3a can be made longer than the center of the film 3, and the side edge 3a at the film grip start position PA is wrinkled. Is no longer generated.

  As shown in FIGS. 4 and 5, on the film entrance 37 side, the side edge 3a of the film 3 is sandwiched and held between the correction roller 41 and the film grip start position PA, and the side edge 3a. An upper guide plate 51 and a lower guide plate 52 are provided. Two guide plates 51 and 52 are provided so as to guide both side edges of the film 3. Each guide plate 51 and 52 is provided so that the ear | edge part 3c cut | disconnected by the ear clip device 60 mentioned later may be inserted | pinched. Thereby, the product part 3b of the film 3 is not damaged.

  The upper guide plate 51 is disposed so as to be positioned above the film 3, the lower guide plate 52 is disposed so as to be positioned below the film 3, and the gap between the upper guide plate 51 and the lower guide plate 52 is Further, the side edge portion 3a is formed smaller than the unevenness in the film thickness direction due to the extension of the ears. Each guide plate 51, 52 is formed with a tapered end. As a result, the side edge 3 a of the film 3 surely enters between the guide plates 51 and 52.

  The lower guide plate 52 contacts the lower surface of the side edge 3a of the film 3, and the upper guide plate 51 holds the side edge 3a in the gap between the lower guide plate 52 and the side edge 3a. Guiding is performed between the base 31b of the clip 30 located at the film grip start position PA and the flapper lower surface 32a. The upper guide plate 51 is located 2 to 40 mm above the pedestal 31b, the lower guide plate 52 is located 0 to 20 mm below the pedestal 31b, and the gap between the upper guide plate 51 and the lower guide plate 52 is The upper guide plate 51 is preferably located 2 to 20 mm above the pedestal 31b, and the lower guide plate 52 is located 0 to 10 mm below the pedestal 31b. More preferably, the gap with the guide plate 52 is 2 to 10 mm. The guide plates 51 and 52 may be provided so as to be movable up and down, and the gap between the upper guide plate 51 and the lower guide plate 52 may be changed according to the thickness of the film 3 or the like.

  When the film 3 enters between the guide plates 51 and 52, the thickness of the side edge 3a is suppressed to be equal to or less than the gap length between the upper guide plate 51 and the lower guide plate 52. It will be corrected.

  Each of the guide plates 51 and 52 is disposed such that one end is located on the upstream side of the film grip start position PA and the other end is located on the downstream side of the film grip start position PA. The ear extension of the side edge 3a of the film 3 is corrected by the guide plates 51 and 52. Thereby, the side edge part 3a of the film 3 can be reliably guided between the base 31b and the flapper lower surface 32a, and the film 3 is reliably gripped by the clip 30 without being disengaged. Furthermore, since the ear extension of the side edge 3a is corrected, the side edge 3a is not pushed out by the tip of the flapper 32 when gripping the film. The film 3 securely held by the clip 30 is stably stretched by the tenter 5.

  Returning to FIG. 1, the film 3 is stretched by the tenter 5, and then sent to the ear-cutting device 60. The edge-cutting device 60 cuts both side edge portions 3a of the film 3 in the film transport direction A and separates the product portion 3b and the ear portion 3c. The slit-like ear portion 3 c thus cut is cut into small pieces by the cut blower 61. The cut ear piece is sent to a crusher 62 by an air feeding device (not shown) and crushed into chips. This chip is reused for dope preparation.

  The film 3 from which the side edge portion 3 a has been cut off by the edge cutting device 60 is sent to the thermal relaxation chamber 6. The heat relaxation chamber 6 is provided with a large number of rollers 63, and the film 3 is conveyed through the heat relaxation chamber 6 by the rollers 63. The film 3 is heat-treated by sending wind at a desired temperature from the blower (not shown) into the heat relaxation chamber 6. The temperature of the wind at this time is preferably 20 ° C to 250 ° C. The film 3 gradually decreases in temperature.

  The film 3 after heat relaxation is sent to the cooling chamber 7 and cooled to 30 ° C. or lower, and then sent to the winding chamber 8. Inside the winding chamber 8, a winder 65 in which a winding core 64 is set is provided. The film 3 sent to the winding chamber 8 is taken up by the winding core 64. At this time, the sheet is pressed and wound by the press roller 65a.

  The film 3 may be any film produced by a well-known solution casting method. For example, a TAC film described in JP-A-2005-104148 can be used. In particular, in order to improve the film forming speed, a dope containing TAC and a solvent is cast on the peripheral surface of a cooled casting drum, and the cast film is cooled and gelled to be self-supporting. The TAC film having excellent optical characteristics can be produced efficiently and without waste by carrying out the present invention with respect to the TAC film that has been taken and dried through the pin tenter.

  Further, as shown in FIG. 6, an air compressor 70 and an air blowing nozzle 71 that blows air from the air compressor 70 may be provided. The air blowing nozzle 71 blows air from the gap between the upper guide plate 51 and the lower guide plate 52 toward the side edge 3 a of the film 3. Thereby, the side edge 3a can be gripped while the film 3 is stretched in the film width direction B, and the side edge 3a can be gripped more stably.

  In the above embodiment, each of the two guide plates 51 and 52 is provided. However, the guide plates 51 and 52 may be integrated into a single upper correction plate and lower correction plate.

  Moreover, in the said embodiment, although the clip opened and closed by spring urging | biasing was used, you may use the clip which has a self-weight fall system clip and other various drive means besides this.

  Furthermore, in the said embodiment, although demonstrated using a TAC film as a polymer film, this invention is applicable also to various polymer films, without being limited to a TAC film.

  As a polymer film that can be used in the present invention, for example, in addition to a cellulose acylate film, a polymer film such as a cyclic olefin produced by a solution casting method, or a polymer film produced by a melt casting method The present invention can be applied.

(Cellulose acylate)
As the cellulose acylate, triacetyl cellulose (TAC) is particularly preferable. Of the cellulose acylates, those in which the hydroxyl group of cellulose is esterified with carboxylic acid, that is, the substitution degree of the acyl group satisfies all of the following formulas (I) to (III) are more preferable. In the following formulas (I) to (III), A and B represent the substitution degree of the acyl group, the substitution degree A is the substitution degree of the acetyl group, and the substitution degree B is the acyl group having 3 to 22 carbon atoms. Is the degree of substitution. In addition, it is preferable that 90 weight% or more of TAC is a particle | grain of 0.1 mm-4 mm.
(I) 2.5 ≦ A + B ≦ 3.0
(II) 0 ≦ A ≦ 3.0
(III) 0 ≦ B ≦ 2.9
The polymer used in the present invention is not limited to cellulose acylate.

  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 of the hydroxyl group of cellulose esterified at each of the 2-position, 3-position and 6-position (100% esterification has a substitution degree of 1).

  The total acylation substitution degree, that is, 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, DS6 / (DS2 + DS3 + DS6) is preferably 0.28 or more, more preferably 0.30 or more, and particularly preferably 0.31 to 0.34. Here, DS2 is the degree of substitution of the hydroxyl group at the 2-position of the glucose unit with an acyl group (hereinafter also referred to as “degree of acyl substitution at the 2-position”), and DS3 is the degree of substitution of the hydroxyl group at the 3-position with an acyl group (hereinafter, DS6 is the substitution degree of the hydroxyl group at the 6-position with an acyl group (hereinafter also referred to as “acyl substitution degree at the 6-position”).

  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. When the sum of the substitution degrees by the hydroxyl groups at the 2nd, 3rd and 6th positions is DSA, and the sum of the substitution degree by an acyl group other than the acetyl group at the 2nd, 3rd and 6th hydroxyl groups is DSB, the value of DSA + DSB is More preferably, it is 2.22 to 2.90, and particularly preferably 2.40 to 2.88. The DSB is 0.30 or more, particularly preferably 0.7 or more. Further, 20% or more of DSB is a substituent at the 6-position hydroxyl group, more preferably 25% or more is a substituent at the 6-position hydroxyl group, more preferably 30% or more, and particularly 33% or more is a 6-position hydroxyl group. It is preferable that it is a substituent. Furthermore, the cellulose acylate having a substitution degree of 6-position of cellulose acylate of 0.75 or more, further 0.80 or more, and particularly 0.85 or more can be mentioned. With these cellulose acylates, a solution having a preferable solubility (dope) can be produced. In particular, in a non-chlorine organic solvent, a good solution can be produced. Furthermore, it is possible to produce a solution having a low viscosity and good filterability. 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 the cellulose acylate of the present invention may be an aliphatic group or an aryl group and is not particularly limited. These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group. Preferred examples of these include propionyl, butanoyl, pentanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, oleoyl, benzoyl , Naphthylcarbonyl, cinnamoyl group and the like. Among these, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are more preferable, and propionyl and butanoyl are particularly preferable.

  The details of cellulose acylate are described in paragraphs [0140] to [0195] of JP-A-2005-104148. The same applies to additives such as solvents and plasticizers, deterioration inhibitors, UV absorbers (UV agents), optical anisotropy control agents, retardation control agents, dyes, matting agents, release agents, release accelerators, etc. JP-A-2005-104148 describes in detail in paragraphs [0196] to [0516]. A film production method by a solution casting method using cellulose acylate is also described in detail in paragraphs [0517] to [0913] of JP-A-2005-104148. These descriptions are also applicable to the present invention.

(Cyclic olefin)
The cyclic olefin is preferably polymerized from a norbornene compound. This polymerization can be carried out by either ring-opening polymerization or addition polymerization. Examples of the addition polymerization include those described in Japanese Patent No. 3517471, Japanese Patent No. 3559360, Japanese Patent No. 3867178, Japanese Patent No. 3817721, Japanese Patent No. 3907908, Japanese Patent No. 3945598, Japanese Patent Publication No. 2005-527696, Japanese Patent Laid-Open No. 2006-2006. No. 28993 and International Publication No. 2006/004376 pamphlet. Particularly preferred is the one described in Japanese Patent No. 3517471.

  As the ring-opening polymerization, WO 98/14499 pamphlet, Japanese Patent No. 30605532, Japanese Patent No. 3320478, Japanese Patent No. 3273046, Japanese Patent No. 3404027, Japanese Patent No. 3428176, Japanese Patent No. 3687231, Japanese Patent No. 3873934, Patent No. 3912159 is mentioned. Among them, those described in WO98 / 14499 pamphlet and Japanese Patent No. 30605532 are preferable. Of these cyclic olefins, those of addition polymerization are more preferred.

(Lactone ring-containing polymer)
The thing which has the lactone ring structure represented by the following (general formula 1) is pointed out.

In (General Formula 1), R ¹ , R ² , and R ³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom.

  The content ratio of the lactone ring structure of (General Formula 1) is preferably 5 to 90% by weight, more preferably 10 to 70% by weight, and still more preferably 10 to 50% by weight.

  In addition to the lactone ring structure represented by (General Formula 1), at least selected from (meth) acrylic acid esters, hydroxyl group-containing monomers, unsaturated carboxylic acids, and monomers represented by the following (General Formula 2). A polymer structural unit (repeating structural unit) constructed by polymerizing one kind is preferred.

In General Formula 2, R ⁴ represents a hydrogen atom or a methyl group, X is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an —OAc group, a —CN group, a —CO—R ⁵ group, or an -C-O-R ⁶ group, Ac group represents an acetyl group, R ⁵ and R ⁶ represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms.

  For example, those described in International Publication No. 2006/025445, JP 2007-70607 A, JP 2007-63541 A, JP 2006-171464 A, and JP 2005-162835 A can be used. .

(Polymer used in melt film forming method)
The polymer that can be used in the melt film-forming method is not particularly limited as long as it is a thermoplastic resin. For example, cellulose acylate, lactone ring-containing polymer, cyclic olefin, polycarbonate and the like can be mentioned. 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.

It is a top view which shows an offline extending | stretching apparatus. It is a top view which shows a tenter. It is a side view which shows the state just before the grip start of a clip. It is a perspective view which shows a film, an upper guide plate, a lower guide plate, and a clip. It is a side view which shows a film, an upper guide plate, a lower guide plate, and a clip. It is a perspective view which shows the film, upper guide plate, lower guide plate, and clip of embodiment which provided the air compressor and the air spray nozzle. It is a figure which shows the conventional film before extending | stretching with a tenter.

Explanation of symbols

2 Offline Stretching Device 3 TAC Film 3a Side Edge 5 Tenter 30 Clip 31 Frame 31b Base 32 Flapper 36 Clip Closer 41 Straightening Roller 41a Center Axis 41b Side Edge Shaft 42 Winding Roller 51 Upper Guide Plate 52 Lower Guide Plate 60 Ear Cutting apparatus

Claims (7)

A gripping position for gripping the side edges of the film, selectively a plurality of clips that will be set in an open position for opening the gripping of the side edges, are arranged on both sides of the traveling path of the film, A plurality of clips that move in the running direction of the film, and a stretching apparatus body that stretches the film in the width direction;
A first guide plate that is disposed on the film entrance side of the stretching apparatus main body, contacts the lower surfaces of both side edges of the film in the width direction, and guides the side edges to the clip at the open position;
A second guide that is provided above the first guide plate and that positions both side edges in the width direction of the film in the gap between the first guide plates and guides the both side edges to the clip in the open position. With a board ,
One end of the first guide plate and the second guide plate is located upstream of the film grip start position where the film is started to be gripped by the clip, and the other end is the film grip start position. A film stretching apparatus located on the downstream side . The film stretching apparatus according to claim 1, wherein a gap between the first guide plate and the second guide plate is 2 to 30 mm.   2. An ear cutting part for cutting both side edges of the film held by the first guide plate and the second guide plate in a film running direction and separating the film into a product part and an ear part. 2. The film stretching apparatus according to 2. A first area that is disposed upstream of the first guide plate and the second guide plate in the film running direction and that contacts both side edges of the film in the width direction is a first area in which a center portion in the width direction of the film contacts. A straightening roller having a diameter larger than the area of 2;
The film stretching apparatus according to any one of claims 1 to 3, further comprising a winding roller that winds the film around the correction roller.   The winding roller is characterized in that the first area where both side edges in the width direction of the film are in contact with each other is formed to have a larger diameter than the second area where the central portion in the width direction of the film is in contact. The film stretching apparatus according to claim 4. The clip includes a frame having a pedestal, a flapper swingably attached to the frame so as to hold the film between the pedestal, the open position where the tip of the flapper is separated from the pedestal, A coil spring that presses the tip of a flapper against the pedestal and urges the film by the tip of the flapper and the pedestal in both directions of the gripping position;
The film entrance side is provided with a clip closer that abuts the flapper and urges the flapper from the open position to the gripping position to grip both side edges of the film with the clip. The film stretching apparatus according to any one of claims 1 to 5. A gripping position for gripping the side edges of the film, selectively a plurality of clips that will be set in an open position for opening the gripping of the side edges, are arranged on both sides of the traveling path of the film, A stretching step of stretching the film in the width direction by a plurality of clips moving in the running direction of the film;
The film is arranged such that one end is located on the upstream side of the film traveling path of the film grip start position where grip of the film is started by the clip, and the other end is located downstream of the film grip start position. A first guide plate that contacts the lower surfaces of both side edges in the width direction of the film and guides the both edges to the clip in the open position, and upstream of the film grip start position. A second end that is positioned so that one end is positioned on the side and the other end is positioned on the downstream side of the film grip start position, and both side edges in the width direction of the film are positioned in a gap between the first guide plate and the second guide plate. A film stretching method comprising: a guide plate for guiding the side edge portions to the clip at the open position by a guide plate.

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