JP2017043091A - Manufacturing method of slit processed stretched film and manufacturing apparatus thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a slit processed stretched film, with which wrinkles or breakage caused by the wrinkles are prevented from occurring in the stretched film during transportation.SOLUTION: There is provided a manufacturing method of a slit processed stretched film, which includes: a stretching step for obtaining a stretched film EF obtained by stretching a resin film RF at least in a width direction by expanding a distance between clips while clamping both ends of a long belt-like resin film RF with the clips respectively; a step of sticking a protective film PF1 to the stretched film EF by passing them between a pair of nip rolls 14 in a state where the protective film PF1 is superposed on the stretched film EF; and a cutting step of cutting end parts of the stretched film EF together with the protective film PF1 by slit processing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and apparatus for producing a slit processed stretched film.

  For example, in an image display apparatus using an optical display device such as a liquid crystal display element, various optical films such as an optical compensation film (retardation film), a polarizer protective film, and an antireflection film are used.

  In the production of such an optical film, a long belt-shaped resin film as a raw material may be stretched in the width direction (lateral stretching) for the purpose of imparting desired optical properties or imparting toughness ( For example, see Patent Document 1.) Specifically, while continuously transporting a long belt-shaped resin film in the length direction, the resin film is stretched in the width direction by holding both ends thereof with clips and increasing the distance between the clips. . In such a method for producing a stretched film, the gripped both end portions remain substantially the same thickness as the resin film as a raw material, while the portion between them becomes thin by stretching. For this reason, the stretched film after stretching is usually a slit-processed stretched film having a predetermined width and a uniform thickness in the width direction by cutting (slit) both ends of the stretched film. The slit-processed stretched film having a predetermined width is usually shipped as a product after being wound on a roll.

  By the way, there is a difference in thickness between the both ends gripped by the above-mentioned stretched film clip and the central portion that has been stretched and thinned. The film is easily wrinkled. Further, due to the wrinkles, the stretched film may be broken before being slit. Such breakage tends to occur when a relatively brittle and easily broken resin film such as polymethyl methacrylate (PMMA) or polystyrene (PS) is stretched.

  Thus, in order to prevent breakage of the stretched film due to wrinkles generated during conveyance, in the invention described in Patent Document 1, the width of the roll that is first brought into contact with the film released from gripping by the clip after lateral stretching is set. Making it narrower than the width of the film is performed. Moreover, the stretched film is slit at both ends in the laterally stretched state.

  However, if slitting both ends of the stretched film in the state of being stretched horizontally, the stretched film is not stable immediately after being stretched horizontally, so the stretched film snakes or wrinkles occur in the stretched film. To do. As a result, a state in which the slit blade does not properly hit the stretched film occurs. Further, if the blade does not properly hit the stretched film, breakage may occur at both ends of the stretched film. In particular, when the stretched film is thin, relatively many breaks of the stretched film occur.

JP 2010-36414 A

  The present invention has been proposed in view of such conventional circumstances, and after being stretched laterally and before performing slit processing, wrinkles on the stretched film being conveyed and breakage due to the wrinkles It aims at providing the manufacturing method and manufacturing apparatus of the slit process stretched film which prevented generating.

  As a means for solving the above-mentioned problems, according to an aspect of the present invention, at least the resin film is formed by increasing the distance between the clips while holding the both ends of the long belt-shaped resin film with the clips. Stretching step for obtaining a stretched film stretched in the width direction, and laminating the protective film on the stretched film by passing between a pair of nip rolls in a state where the protective film is superimposed on the stretched film. The manufacturing method of the slit process stretched film characterized by including the process and the cutting process which cut | disconnects the edge part of the said stretched film with the said protective film by slit process in this order is provided.

  Moreover, in the manufacturing method of the slit processed stretched film of the said aspect, in the center part of at least 1 guide roll among the guide rolls which the said stretched film contacts with the said stretched film before passing between between said pair of nip rolls. A contact region that is more easily contacted with the stretched portion of the stretched film than both ends of the guide roll, and the width of the contact region is the distance between the clips when the gripping by the clip is released A narrower width is preferred.

  Moreover, in the manufacturing method of the slit process stretched film of the said aspect, the guide roll located just before the said pair of nip rolls among the said guide rolls is more than the distance between the said clips when the holding | grip by the said clip is cancelled | released. A roll provided with a narrow contact area is preferred.

  Moreover, in the manufacturing method of the slit process stretched film of the said aspect, all the said guide rolls are rolls provided with the contact area of the width | variety narrower than the distance between the said clips when the holding | grip by the said clip is cancelled | released. Preferably there is.

  Moreover, in the manufacturing method of the slit process stretched film of the said aspect, the roll in which the said contact area was provided has the 1st roll surface which has the width | variety corresponding to the said contact area, and the width | variety which pinched | interposed the said 1st roll surface A pair of second roll surfaces each having an outer diameter smaller than that of the first roll surface on both sides in the direction, and the pair of second roll surfaces easily come into contact with both end portions of the stretched film. It is preferable to form a contact area.

  Moreover, in the manufacturing method of the slit processed stretched film according to the aspect, one of the pair of nip rolls is provided with a contact area having a width narrower than a distance between the clips when the gripping by the clips is released. It is preferable that the roll is made.

  Moreover, in the manufacturing method of the slit processed stretched film of the said aspect, the roll of the side which contacts the said protective film among the said pair of nip rolls is a roll provided with the contact area | region wider than the width | variety of the said protective film. It is preferable.

  Moreover, in the manufacturing method of the slit processed stretched film of the said aspect, after cutting the edge part of the said stretched film, the guide roll which contacts the slit processed stretched film after cutting or the said protective film is the said slit processed stretched film or the above-mentioned A roll provided with a contact area wider than the width of the protective film is preferable.

  Further, according to another aspect of the present invention, the resin film is stretched at least in the width direction by widening the distance between the clips while holding both ends of the long belt-shaped resin film with the clips. A stretched portion for obtaining a film, a bonding portion for laminating the protective film on the stretched film by passing between a pair of nip rolls in a state where the protective film is superimposed on the stretched film, and the stretched film An apparatus for producing a slit-processed stretched film is provided, comprising a cutting section that cuts an end portion together with the protective film by slit processing.

  As described above, according to the aspect of the present invention, the protective film is bonded to the stretched film obtained by stretching the resin film at least in the width direction, and the end portion of the stretched film is cut together with the protective film by slit processing. It is possible to prevent wrinkles of the stretched film inside and breakage due to the wrinkles and to continuously wind the slit-processed stretched film after slit processing for a long time.

It is a side view which shows the structure of the manufacturing apparatus of the slit process stretched film which concerns on one Embodiment of this invention. It is a side view which shows the structure of an extrusion part. It is a top view which shows the structure of a longitudinal stretch part. It is a top view which shows the structure of the extending | stretching part with which the manufacturing apparatus shown in FIG. It is a top view which shows the structure of the cutting part with which the manufacturing apparatus shown in FIG. 1 is provided. It is a side view which expands and shows the principal part of the manufacturing apparatus shown in FIG. It is a top view which expands and shows the principal part of the manufacturing apparatus shown in FIG. It is a front view which shows the structure of the guide roll which a stretched film contacts before a nip. It is a front view which shows the structure of one roll among a pair of nip rolls. It is a front view which shows the structure of the guide roll which a slit process stretched film contacts after a slit process. It is a front view which shows the other structure of the guide roll which a stretched film contacts before nip.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent. In addition, the materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not necessarily limited thereto, and can be appropriately modified and implemented without departing from the scope of the invention. .

  In this embodiment, for example, as a production system for an optical display device, a manufacturing apparatus for a slit processed stretched film constituting a part thereof and a method for manufacturing a slit processed stretched film using the manufacturing apparatus will be described.

(Slit processing stretched film manufacturing equipment)
First, as an embodiment of the present invention, for example, a slit-processed stretched film manufacturing apparatus 1 shown in FIG. 1 will be described. In addition, FIG. 1 is a side view which shows the structure of the manufacturing apparatus 1 of a slit process stretched film.

  The manufacturing apparatus 1 of the slit processed stretched film of this embodiment is bonded to an optical display device such as a liquid crystal display element or an organic EL display element, for example, an optical compensation film (retardation film), a polarizer protective film or a reflection film. An optical film such as a prevention film is produced. Moreover, this manufacturing apparatus 1 uses the long strip-shaped resin film RF as a raw material for the purpose of imparting desired optical characteristics or imparting toughness among such optical films, and at least the width direction thereof. A stretched film EF stretched (laterally stretched) is produced.

  Specifically, as shown in FIG. 1, the slit-processed stretched film manufacturing apparatus 1 has a stretched portion 3, a first bonding portion 4, a first cutting portion 5, and a second bonding portion. 6, a second cutting part 7, and a winding part 8. Among these, the extending | stretching part 3 is arrange | positioned in the oven 9. FIG.

  The resin film RF as a raw material can be manufactured as an extruded film F by the extrusion unit 2 having a configuration as shown in FIG. Specifically, the extrusion unit 2 continuously extrudes the heat-melted thermoplastic resin from the lip 10 a provided at the tip of the extruder 10 in the form of a film. The thermoplastic resin extruded into a film form from the lip 10a is cooled while passing between the plurality of cooling rolls 10b, and becomes an extruded film F having a substantially uniform thickness in the width direction. The extruded film F produced by the extruding unit 2 may be continuously conveyed from the extruding unit 2 as it is to the stretching unit 3 as a resin film RF. Or after winding up this extrusion film F in roll shape, you may make it wind this roll-form extrusion film F and convey to the manufacturing apparatus 1 as resin film RF.

  Further, the extruded film F obtained at the extrusion unit 2 may be stretched in the length direction (longitudinal stretching) and then supplied to the manufacturing apparatus 1 as the resin film RF. When the extruded film F is stretched in the longitudinal direction, the extruded film F is stretched in the longitudinal stretching section 11 having two pairs of nip rolls 11a and 11b as shown in FIG. 3, for example. When the extruded film F is longitudinally stretched in such a longitudinal stretching section 11, the extruded film F first passes between the pair of nip rolls 11a while being conveyed in the length direction, and then further passes between the pair of nip rolls 11b. To do. Further, the peripheral speed of the nip roll 11b that passes next is made faster than the peripheral speed of the nip roll 11a that passes first. Thereby, the longitudinal stretch which extends | stretches the extrusion film F to a length direction can be performed. Note that an oven or the like may be disposed between the nip rolls 11a and 11b shown in FIG. 3 to be in a heating environment, or the extruded film F may be heated by the nip roll 11a and / or the nip roll 11b.

  When longitudinally stretching the extruded film F, the extruded film F continuously obtained by the extrusion unit 2 may be continuously stretched by being supplied between the pair of nip rolls 11a as it is. Alternatively, after the extruded film F is once wound up in a roll shape, the roll-shaped extruded film F may be unwound and supplied between the pair of nip rolls 11a for longitudinal stretching.

  The longitudinally stretched resin film RF may be continuously supplied to the manufacturing apparatus 1 as it is. Alternatively, the longitudinally stretched resin film RF may be once wound up in a roll shape, and then supplied to the manufacturing apparatus 1 while the roll-shaped resin film RF is unwound.

  In the manufacturing apparatus 1 shown in FIG. 1, the resin film RF thus obtained is first stretched by the stretching section 3. In the extending | stretching part 3, the horizontal extending | stretching which extends | stretches resin film RF in the width direction is performed.

  Specifically, as shown in FIG. 4, the resin film RF conveyed to the extending portion 3 is gripped at both ends by two rows of clip rows 12. The two clip rows 12 have a configuration in which a plurality of clips 12a are arranged in a straight line on both sides in the width direction across the resin film RF. In the extending part 3 in the oven 9, the clip 12a is transported to the downstream CLb in the transport direction together with the resin film RF while holding both ends of the resin film RF by the respective clips 12a on the upstream side CLa in the transport direction. In the meantime, by extending the distance between the clips 12a, the resin film RF or the longitudinally stretched film is stretched (laterally stretched) in the width direction to obtain a stretched film EF.

  The stretched film EF is released from being gripped by the clip 12a on the downstream side CLb in the transport direction after stretching. On the other hand, when the clip 12a is returned from the downstream side CLb in the transport direction to the upstream side CLa, both ends of the resin film RF are again gripped by the clips 12a.

  As shown in FIG. 1, the stretched film EF obtained in the stretching unit 3 is conveyed to the first bonding unit 4 while being guided by a plurality of guide rolls 13. The first bonding unit 4 includes a pair of nip rolls 14. In the 1st bonding part 4, the 1st protection of the elongate strip shape unwound from the raw fabric roll R1 on one surface of the stretched film EF conveyed in the state hung between the some guide rolls 13 is carried out. The film PF1 is passed between the pair of nip rolls 14 with the film PF1 overlapped. Thereby, the 1st protective film PF1 is bonded (laminated | stacked) on one surface of the stretched film EF.

  The width of the first protective film PF1 is wider than the width that is cut (slit) by the first cutting portion 5 described later, and is narrower than the width when the stretched film EF is released from gripping by the clip 12a. Is preferred. The stretched film EF to which the first protective film PF1 is bonded is conveyed to the first cutting unit 5 while being guided by the plurality of guide rolls 15.

  As shown in FIG. 5, the first cutting unit 5 includes a shear blade 16. The shear blades 16 are respectively disposed on both sides in the width direction of the stretched film EF to which the first protective film PF1 is bonded. The shear blade 16 includes an upper blade 16a and a lower blade 16b. The upper blade 16a and the lower blade 16b are disposed at positions where the stretched film EF and the first protective film PF1 are sandwiched in the thickness direction.

  In the 1st cutting part 5, the both ends of the stretched film EF conveyed in the state hung between the several guide rolls 15, ie, the part RFs grasped by the clip 12a of the resin film RF described above, are first protected. Along with the film PF1, it is cut (slit) by slitting using the shear blade 16. In the present embodiment, an example in which slit processing is performed using the shear blade 16 as the first cutting portion 5, that is, a case in which both ends RFs of the stretched film EF are cut (slit) is exemplified. The slitting may be performed by a cutting machine used, for example, a laser cutting machine, an ultrasonic cutting machine, a fixed cutting blade (feather blade), or the like.

  Since the portions (both ends of the stretched film EF before slitting) RFs gripped by the clip 12a of the resin film RF are not stretched, the portions stretched by the stretching portion 3 described above (of the stretched film EF before slitting) The center part) is thicker than RFc. On the other hand, the center part RFc of the stretched film EF before slit processing is thinner than the thickness of the resin film RF by stretching, and usually has a predetermined width and a substantially constant thickness.

  Thereafter, as shown in FIG. 1, both ends RFs of the stretched film EF that has been cut (slit) are the first ends in a state in which the first protective film PF1 that has been cut (slit) at the same time is bonded. The material film SF1 is collected by being wound on a take-up reel 17, respectively. On the other hand, the slit processed stretched film EFc after both ends RFs are cut (slit) is second bonded while being guided by the plurality of guide rolls 18 in a state where the first protective film PF1 is bonded. It is conveyed to the part 6.

  The second bonding unit 6 includes a pair of nip rolls 19. In the 2nd bonding part 6, in the other surface of the slit process extending | stretching film EFc conveyed in the state hung between the some guide rolls 18, it is the elongate strip | belt shape unwound from the original fabric roll R2. The second protective film PF <b> 2 is overlaid and passed between the pair of nip rolls 19 in this state. Accordingly, the second protective film PF2 is bonded to the other surface of the slit processed stretched film EFc.

  Note that the width of the second protective film PF2 is preferably wider than the width cut by the second cutting portion 7 described later, and is equal to or larger than the width of the slit processed stretched film EFc. The slit processed stretched film EFc bonded with the second protective film PF is conveyed to the second cutting unit 7 while being guided by the plurality of guide rolls 20.

  The second cutting unit 7 includes a shear blade 21. The shear blade 21 is composed of the same upper blade and lower blade as the shear blade 16. The upper blade and the lower blade are disposed at positions where the slit processed stretched film EFc, the first protective film PF1, and the second protective film PF2 are sandwiched in the thickness direction. The shear blades 21 are respectively arranged on both sides in the width direction of the slit processed stretched film EFc to which the second protective film PF2 is bonded.

  In the 2nd cutting part 7, the edge part of the slit process extending | stretching film EFc conveyed in the state hung between the some guide rolls 20 is shared blade with 1st protective film PF1 and 2nd protective film PF2. 21 is cut (slit) into a predetermined width by slitting. In the present embodiment, an example in which slit processing is performed using the shear blade 21 as the second cutting portion 7, that is, a case in which both ends of the slit processing stretched film EFc are cut (slit) is illustrated. Slit processing may be performed by a commonly used cutting machine such as a laser cutting machine, an ultrasonic cutting machine, a fixed cutting blade (feather blade), or the like.

  Thereafter, both ends of the slit processed stretched film EFc cut (slit) are the second in a state where the first protective film PF1 and the second protective film PF2 cut (slit) at the same time are bonded. The end material film SF2 is wound around the take-up reel 22 and collected. On the other hand, the slit-processed stretched film EFc after both ends are cut (slit) is a state in which the first protective film PF1 is bonded to one surface and the second protective film PF2 is bonded to the other surface. While being guided by a plurality of guide rolls 23, it is conveyed to the winding unit 8 as a slit processed stretched film EFc.

  The winding unit 8 includes a winding roll 24. In the winding unit 8, the slit processed stretched film EFc that has been conveyed in a state of being wound between the plurality of guide rolls 23 is wound up by the winding roll 24. The slit-processed stretched film EFc after winding is used as, for example, an optical film or a raw material thereof.

  In the manufacturing apparatus 1 of the slit processed stretched film of this embodiment, the stretched film EF being conveyed is bonded to the stretched film EF obtained by stretching the resin film RF in the width direction (lateral stretching). And the occurrence of breakage due to the wrinkles can be prevented.

  Further, in the slit processed stretched film manufacturing apparatus 1 of the present embodiment, the end portion of the stretched film EF (the portion RFs gripped by the clip 12a of the resin film RF) is cut (slit) by slitting together with the first protective film PF1. By doing so, it is possible to prevent the film piece (powder) from being mixed due to the slit defect while preventing the occurrence of the defect at the time of the slit.

  Therefore, in the slit-processed stretched film manufacturing apparatus 1 of the present embodiment, the slit-processed stretched film EFc can be continuously wound for a long time without causing the wrinkles of the stretched film EF and the breakage caused by the wrinkles. It is. Moreover, by preventing the wrinkle from being generated in the stretched film EF, the film piece (powder) is not generated at the time of slit processing due to the wrinkle, and the film piece may be wound in a mixed state. Nor.

(Manufacturing method of slit processed stretched film)
Next, the manufacturing method of the slit process stretched film using the manufacturing apparatus 1 of the said slit process stretched film is demonstrated with reference to FIG.6 and FIG.7. FIG. 6 is an enlarged side view showing the main part of the slit processed stretched film manufacturing apparatus 1. FIG. 7 is an enlarged plan view showing the main part of the slit-processed stretched film manufacturing apparatus 1.

  The slit-processed stretched film manufacturing method using the slit-processed stretched film manufacturing apparatus 1 is long as a method for manufacturing a slit-processed stretched film according to one embodiment of the present invention, as shown in FIGS. A stretching process for obtaining a stretched film EF obtained by stretching the resin film RF at least in the width direction by widening the distance between the clips 12a while holding both ends of the belt-shaped resin film RF with the clips 12a, and a stretched film EF. A bonding step of bonding the protective film PF1 to the stretched film EF by passing between the pair of nip rolls 14 in a state where the first protective film (hereinafter simply referred to as a protective film) PF1 is overlaid, A cutting step of cutting an end portion of the stretched film EF together with the protective film PF1 by slitting; , Including in this order.

  Usually, a thermoplastic resin film made of a thermoplastic resin is used as the resin film RF used in the present embodiment. Further, it is preferable to use a resin film RF having translucency (preferably optically transparent). Specific examples of the material of the resin film RF include polyolefin resins such as chain polyolefin resins, cyclic polyolefin resins (such as norbornene resins), polyethylene resins, and polypropylene resins. Also, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and poly-L-lactic acid can be exemplified. Moreover, (meth) acrylic-type resin, such as methyl methacrylate-type resin, can be mentioned. Moreover, cellulose resin, such as a cellulose triacetate and a cellulose diacetate, can be mentioned. Moreover, polycarbonate resin, polyvinyl alcohol resin, polyvinyl acetate resin, polyarylate resin, polystyrene resin, polyethersulfone resin, polysulfone resin, polyamide resin, polyimide resin, and the like can be given. Furthermore, a mixture or copolymer containing 50% by weight or more of these materials as main components can be used. Among these, (meth) acrylic resins and polystyrene resins are preferable because of their low toughness, and thus the effects of the present invention can be further exhibited.

  As the resin film RF used in the present invention, a resin film with a conventionally known additive may be used as necessary. Examples of the additive include an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a nucleating agent, an antifogging agent, and an antiblocking agent. A plurality of additives may be used in combination from these additives.

  The protective film PF1 preferably has adhesiveness to the resin film RF. Specific examples include a protective film in which an adhesive layer is provided on a base film such as a polyethylene resin film, a polypropylene resin film, and a polyester resin film such as polyethylene terephthalate. As the protective film PF1, it is preferable to use a resin film having self-adhesiveness from the viewpoint of economy. As the resin film having self-adhesiveness, for example, a polyethylene self-adhesive film can be used. Note that a protective film similar to the protective film PF1 can be used for the second protective film PF2.

  In the stretching step, conventionally known stretching methods can be appropriately selected and used. Among them, it is preferable to perform transverse stretching using a tenter method.

  Before the stretching step, usually includes a preheating step of preheating the resin film RF with hot air, and after the stretching step, usually includes a heat setting step of heating and stabilizing the stretched film EF.

  The preheating step is a step of heating to a temperature sufficient to stretch the resin film RF. The preheating temperature of the resin film RF is preferably in the range of T-10 ° C. to T + 50 ° C., where T is the phase transition temperature (glass transition temperature or melting point) of the resin constituting the resin film RF. More preferably, the temperature is in the range of C.degree.

  The stretching temperature of the resin film RF is preferably T-10 ° C to T + 50 ° C, more preferably T ° C to T + 30 ° C. The draw ratio in the width direction of the resin film RF is, for example, 1.2 to 5 times, and preferably 1.5 to 4 times. A draw ratio of 1.5 times or more is preferable because toughness is appropriately imparted to the stretched film EF.

A draw ratio is calculated | required by a following formula.
Stretch ratio (times) = (Length after stretching) / (Length before stretching)
In addition, the length said here is the length of the extending direction of the resin film RF before extending | stretching or the stretched film EF after extending | stretching, and this length is the width | variety of the resin film RF or the extending | stretched film EF in the case of lateral stretching. Equivalent to.

  The heat setting step is a step of passing through a zone maintained at a predetermined temperature in the oven 9 with the width of the stretched film EF substantially maintained at the end of stretching. Moreover, you may pass through the zone maintained at the predetermined temperature in the oven 9, narrowing the width | variety of the stretched film EF from the time of completion | finish of extending | stretching.

  When passing a thorn while narrowing the width of the stretched film EF, the shrinkage width of the stretched film EF is, for example, 15% or less, preferably 5% or less. It is preferable that the temperature of the zone in the oven 9 is the same as or lower than the stretching temperature.

  The thickness of the stretched film EF obtained after the stretching step is, for example, 3 to 100 μm, preferably 4 to 80 μm, more preferably 5 to 40 μm, in the central portion in the width direction. As the thickness of the stretched portion (central portion) of the stretched film EF is smaller, wrinkles as described above tend to be more likely to occur. On the other hand, according to the manufacturing method of this embodiment, even if the thickness of the stretched film EF in the central portion in the width direction is 100 μm or less, and further 40 μm or less, wrinkles generated during conveyance are reduced, which is caused by the wrinkles. The risk of breakage can be kept low. For this reason, the manufacturing method of this invention is suitable when manufacturing such a thin stretched film EF.

  The stretched film EF obtained in the stretching step is released from gripping by the clip 12a on the downstream side CLb in the transport direction, and is sent to the next bonding step while being guided by the plurality of guide rolls 13. The clip 12a after releasing the stretched film EF is sent to the upstream side in the transport direction, and grips the resin film RF or the longitudinally stretched resin film RF again.

  The pasting step is a step of passing between the pair of nip rolls 14 in a state where the protective film PF1 is superposed on one surface of the stretched film EF. Of the pair of nip rolls 14, one roll 14a is an elastic roll whose outer peripheral surface is made of an elastic body such as rubber, and the other roll 14b is plated on the outer peripheral surface using a rigid body such as metal as a base material. It is preferable to use a rigid roll, and the other roll 14b is a drive roll that is rotationally driven directly or indirectly by a drive source.

  Further, on the upstream side of the pair of nip rolls 14, a device for detecting the tension applied to the stretched film EF such as a tension pickup device may be disposed. In this case, the tension applied to the stretched film EF is detected, and the rotation of the nip roll 14 is controlled based on the detection result. Thereby, it is possible to apply an appropriate tension to the stretched film EF and suppress wrinkles generated during conveyance.

  In the manufacturing method of the slit processed stretched film according to the present embodiment, as shown in FIGS. 6, 7, and 8, the stretched film EF is in contact with the stretched film EF before passing between the pair of nip rolls 14. At least one of the guide rolls 13 is provided with a contact region S having a width L2 (L1> L2) narrower than the distance L1 between the clips 12a at the time when the gripping by the clip 12a is released. A roll is preferred.

  As shown in FIG. 8, since the portions (both ends of the stretched film EF before slitting) RFs gripped by the clip 12a of the resin film RF are not stretched, the stretched portions (stretched film before slitting) The center part) is thicker than RFc. Moreover, the part hold | gripped with the clip 12a and the part not hold | gripped are mixed in the both ends of the stretched film EF before slit processing.

  Such a stretched film EF is likely to wrinkle due to a difference in thickness between the central portion RFc and both end portions RFs during conveyance. Further, the thinner the stretched film EF, the more wrinkles generated due to the thickness difference.

  On the other hand, in the manufacturing method of the slit processed stretched film of this embodiment, the stretched film EF is stretched by making the width L2 of the contact region S of the guide roll 13 narrower than the distance L1 between the clips 12a described above. Further, the center portion RFc is more easily in contact with the guide roll 13 in the range of the contact region S than both end portions RFs that have not been stretched. On the other hand, both end portions RFs of the stretched film EF that have not been stretched are less likely to contact the guide roll 13 outside the contact region S than the stretched central portion RFc. Thereby, the tension | tensile_strength for conveyance can be provided to the stretched center part RFc of the stretched film EF, ie, the part where thickness becomes uniform in the width direction of the stretched film EF, and wrinkles occur in the stretched film EF being transported. It can be prevented from occurring. Therefore, in the bonding process, the stretched film EF and the protective film PF1 can be bonded together without any wrinkles.

  Note that the contact region S means that, for example, the outer diameter (diameter) of the guide roll 13 is thicker than both ends, and the stretched portion of the stretched film EF (stretched film before slit processing) compared to both ends. EF (center part of EF) refers to a region that is relatively easy to contact with RFc. That is, in this contact area S, the center part RFc of the stretched film EF is easier to contact than both end parts RFs. Further, in the contact region S, a part of the stretched film EF may not be in contact with the guide roll 13 depending on the transport state of the stretched film EF, for example, the shake of the stretched film EF being transported. In addition, outside of the contact region S, a part of the stretched film EF may come into contact with the guide roll 13 depending on the transport state of the stretched film EF, for example, shake of the stretched film EF being transported.

  Further, among the plurality of guide rolls 13, the guide roll 13 positioned immediately before the pair of nip rolls 14 has a width L2 (L1> L2) that is narrower than the distance L1 between the clips 12a at the time when the gripping by the clip 12a is released. It is more preferable that the roll is provided with the contact region S). Thereby, just before passing the stretched film EF and the protective film PF1 between a pair of nip rolls 14, the stretched film EF can be made into a state without wrinkles.

  Furthermore, a contact area S having a width L2 (L1> L2) narrower than the distance L1 between the clips 12a when all the guide rolls 13 among the plurality of guide rolls 13 are released from being gripped by the clips 12a is provided. It is preferable that the roll is made. Thereby, it can prevent that wrinkles generate | occur | produce in the stretched film EF in conveyance.

  Moreover, in the manufacturing method of the slit processed stretched film of this embodiment, as shown in FIG. 9, one roll (in this embodiment, elastic roll) 14a of a pair of nip rolls 14 is released from gripping by the clip 12a. It is preferable that the roll is provided with a contact region S having a width L3 (L1> L3) narrower than the distance L1 between the clips 12a at the time.

  In this case, by narrowing the width L3 of the contact area S of the one roll 14a than the distance L1 between the clips 12a described above, the stretched central portion RFc of the stretched film EF is made to be a pair of nip rolls 14 (14a, 14b). Pressurize between. On the other hand, both ends RFs of the stretched film EF that have not been stretched pass without being pressed between the pair of nip rolls 14 (14a, 14b).

  Thereby, the tension | tensile_strength for conveyance can be provided to the stretched center part RFc of the stretched film EF, ie, the part where thickness becomes uniform in the width direction of the stretched film EF, and wrinkles occur in the stretched film EF being transported. It can be prevented from occurring. Furthermore, since both ends RFs of the stretched film EF, that is, the unstretched portion having low toughness is not nipped, it is possible to prevent breakage.

  The roll (elastic roll) 14a on the side in contact with the protective film PF1 is preferably a roll provided with a contact region S having a width L3 (L3> L4) wider than the width L4 of the protective film PF1. In this case, since the protective film PF1 can be pressurized over the entire region in the width direction, the stretched film EF and the protective film PF1 can be bonded together without any wrinkles.

  In the cutting step, as shown in FIGS. 6 and 7, both ends RFs of the stretched film EF, that is, the portion gripped by the above-described resin film RF clip 12a are cut (slit) by slit processing together with the protective film PF1.

  In the cutting step, breakage of the stretched film EF can be prevented by cutting (slit) both ends RFs of the stretched film EF together with the protective film PF1 in a state where the protective film PF1 is bonded to the stretched film EF. That is, the protective film PF1 bonded to the stretched film EF suppresses the breakage of the stretched film EF even when the conventional transport tension of the stretched film EF is not stable or the stretched film EF is thin. Will play a role.

  In particular, in the method for producing a stretched film according to this embodiment, for example, a relatively brittle and easily broken resin film RF such as polymethyl methacrylate (PMMA) or polystyrene (PS) is stretched, or the stretched film EF after stretching is thin. In such a case, the risk of breakage from both ends of the stretched film EF increases due to the wrinkles generated in the stretched film EF that is being conveyed as described above. Therefore, it is effective to apply the present invention.

  In the manufacturing method of the slit processed stretched film of this embodiment, as shown in FIG. 10, after cutting both ends RFs of the stretched film EF, the guide roll 18 that contacts the slit processed stretched film EFc or the protective film PF1 after cutting. However, the roll is preferably provided with a contact region S having a width L6 (L5 <L6) wider than the width L5 of the slit processed stretched film EFc. In addition, since no wrinkles are generated in the slit processed stretched film EFc being conveyed, when the slit processed stretched film EFc guided by the guide roll 18 is further cut (slit), cracks caused by wrinkles are slit processed. It can be prevented from occurring in the stretched film EFc.

  In this case, since tension can be uniformly applied to the slit processed stretched film EFc, wrinkles can be prevented from occurring in the slit processed stretched film EFc being conveyed.

  As described above, in the method for producing a slit processed stretched film according to the present embodiment, the protective film PF1 is bonded to the stretched film EF obtained by stretching (transversely stretching) the resin film RF in the width direction. It is possible to prevent wrinkles in EF and breakage due to the wrinkles.

  Moreover, in the manufacturing method of the slit processed stretched film of this embodiment, the end of the stretched film EF is cut (slit) by slit processing together with the protective film PF1, thereby preventing the occurrence of defects at the time of slitting. The mixing of the resulting film piece (powder) can be prevented.

  Therefore, in the manufacturing method of the slit processed stretched film of the present embodiment, the slit processed stretched film EFc is formed without causing the wrinkles of the stretched film EF, the breakage due to the wrinkles, and the mixing of the film pieces. It is possible to wind continuously for a long time.

  In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention. Moreover, in the following description, about the site | part equivalent to the manufacturing apparatus 1 of the said slit process stretched film, while omitting description, the same code | symbol shall be attached | subjected in drawing.

  For example, as shown in FIG. 11, in the guide roll 13 provided with the contact region S, the first roll surface 13a having a width L2 corresponding to the contact region S and the first roll surface 13a are sandwiched. It is good also as a structure which has a pair of 2nd roll surface 13b with an outer diameter smaller than the 1st roll surface 13a at the both sides of the width direction, respectively.

  The pair of second roll surfaces 13b has a width L7 sufficient to contact both end portions RFs of the stretched film EF, and both end portions RFs of the central portion RFc of the stretched film EF between the first roll surface 13a. Has a level difference h corresponding to the difference in thickness. In addition, the level | step difference h between the 1st roll surface 13a and the 2nd roll surface 13b is 0.1 mm-30 mm normally, Preferably it is 0.5 mm-10 mm.

  In this configuration, the pair of second roll surfaces 13b form contact regions that easily come into contact with both ends (portions gripped by the clip 12a of the resin film RF) RFs of the stretched film EF before slitting. In the case of this configuration, the center portion RFc of the stretched film EF before slitting is in contact with the first roll surface 13a, and both end portions RFs of the stretched film EF are in contact with the pair of second roll surfaces 13b. It is possible to transport the stretched film EF before processing more stably without generating wrinkles.

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

<Example 1>
In Example 1, first, pellets of methyl methacrylate / methyl acrylate (weight ratio 94/6) having a glass transition temperature Tg of 108 ° C. were put into an extruder and extruded from a T-shaped die having a set temperature of 270 ° C. . Both sides of the extruded film-like molten resin are sandwiched and cooled by a pair of polishing rolls set at a temperature of 110 ° C., and are elongated strip-like unstretched films (corresponding to the resin film RF) having a thickness of 120 μm and a width of 1000 mm. Was obtained as a film roll.

  Next, an unstretched film is continuously fed from a film roll while being conveyed, and a preheating zone (preheating temperature: 110 ° C.), a longitudinal stretching zone (stretching temperature: 120 ° C.), and a heat setting zone (heat fixing temperature: 120 ° C.). Were passed in order to obtain a longitudinally stretched film having a thickness (thickness in the center in the width direction) of 93 μm and a length of 720 mm as a film roll. The draw ratio of this longitudinal drawing was 1.8 times.

  Next, a longitudinally stretched film is continuously fed from a film roll while being continuously conveyed, a preheating zone (preheating temperature: 120 ° C.), a transverse stretching zone (stretching temperature: 120 ° C.), and a heat setting zone (heat setting temperature: 120 ° C.). Were sequentially stretched to obtain a biaxially stretched film (corresponding to stretched film EF) having a thickness (thickness in the center in the width direction) of 45 μm.

  In the transverse stretching zone, a portion of 10 mm from both ends in the width direction of the longitudinally stretched film was supplied to the transverse stretching machine while being gripped by the clips, and the transverse stretching was performed by widening the interval between the clips. The draw ratio of this transverse drawing was 2.0 times.

  In the guide roll immediately before the nip roll, the first roll surface having a contact width (= 1350 mm) narrower than the distance between the clips (= 1400 mm), and both sides in the width direction sandwiching the first roll surface In addition, a roll having a pair of second roll surfaces having a smaller outer diameter than the first roll surface and having a step of 2 mm between the first roll surface and the second roll surface is disposed. .

  After that, among the nip rolls, one roll is an elastic roll whose surface is made of rubber and the other roll is a drive roll. The roll is passed through a pair of nip rolls, and a protective film (self-adhesive film) is formed on one surface of the biaxially stretched film. After pasting a resin film “trade name: Tretec 7332K, manufactured by Toray Film Processing Co., Ltd., 1500 mm width” and corresponding to the first protective film PF1, the both ends are slit with a shear blade, the width is 1200 mm, After producing a slit processed stretched film having a length of 200 m, it was wound into a roll. The slit processed stretched film has a protective film bonded on one side.

Here, in the process until obtaining the slit processed stretched film, the following “film handling property” evaluation test was performed.
<Film handling>
A film that is stretched from the uppermost stream of a horizontal stretching machine, stretched horizontally, stretched and slitted to produce a slit-processed stretched film, and rolled up continuously for 200m or more in order to wind continuously for 200m or more. The handling property was evaluated. The evaluation criteria are as follows. The evaluation results are shown in Table 1.
(Double-circle): The film handling etc. did not generate | occur | produce especially and the handling of the film was easy.
◯: Any of the following phenomena (1) to (3) occurred, but the film could be handled.
(1) Wrinkles occurred during the passage of the nip roll from immediately after starting the winding after the oven exit until the tension was stably applied to the film until the slit processing was performed from the oven exit. No breakage of the stretched film occurred between.
(2) The film is stretched laterally and immediately after the start of winding up until the film is stably tensioned, the film cannot be slit stably during slitting, and cracks occur on the end face of the stretched film. However, the stretched film did not break between the oven outlet and the slit processing.
(3) When passing through the nip roll, the protective film could not be uniformly bonded in the width direction of the stretched film, and the stretched film was conveyed in that state, so that floating occurred between the stretched film and the portion was slit. At that time, cracks were generated on the end face of the stretched film, but the stretched film was not broken until the slit processing was performed from the outlet of the oven.
X: Breaking of the stretched film occurred after the oven exit of the transverse stretching machine until slitting.

  In Example 1, as shown in Table 1, the stretched film did not break until the slit processing was performed from the oven outlet. Further, slight wrinkles were generated just before the nip roll, but when the protective film was peeled off from the stretched film and the stretched film was visually observed, the wrinkles were not transferred and were in a good state.

  In addition, lateral stretching was performed immediately after starting the winding after the oven exit until the tension was stably applied to the film, and wrinkles to the extent that it was transferred to the stretched film when passing through the nip roll occurred. After tension was stably applied to the stretched film, the problem of wrinkles and breakage did not occur.

  In addition, the film is stretched between the stretched film and the protective film immediately after starting the winding after the oven exit until the tension is stably applied to the film. In this case, cracks occurred on the end face of the stretched film, but no problem of wrinkles or cracks occurred after the tension was stably applied to the stretched film.

<Example 2>
In Example 2, a roll having a contact width (= 1500 mm) wider than the distance L1 (= 1400 mm) between the clips was disposed in the guide roll immediately before the nip roll. Other than that, a slit-processed stretched film was produced in the same manner as in Example 1, and wound into a roll. For Example 2, the same evaluation test as in Example 1 was performed. The evaluation results are shown in Table 1.

  In Example 2, breakage of the stretched film did not occur until the slit processing was performed from the oven exit. In addition, wrinkles were generated just before the nip roll, and wrinkles could not be eliminated by adjusting the tension applied to the film. Moreover, when the protective film was peeled off from the stretched film and the stretched film was visually observed, wrinkles were transferred.

<Example 3>
In Example 3, all of the guide rolls immediately before the nip roll were rolls having a contact width (= 1350 mm) narrower than the distance between the clips (= 1400 mm). Other than that, a slit-processed stretched film was produced in the same manner as in Example 1, and wound into a roll. For Example 3, the same evaluation test as in Example 1 was performed. The evaluation results are shown in Table 1.

  In Example 3, breakage of the stretched film did not occur until the slit processing was performed from the oven exit. In addition, almost no wrinkles occurred immediately before the stretched film passed through the nip roll, and the film could be conveyed stably.

<Example 4>
In Example 4, one roll (elastic roll) of the pair of nip rolls 14 was a roll having a contact width (= 1350 mm) narrower than the distance between clips (= 1400 mm). Other than that, a slit-processed stretched film was produced in the same manner as in Example 2, and wound into a roll. For Example 4, the same evaluation test as in Example 1 was performed. The evaluation results are shown in Table 1.

  In Example 4, the stretched film did not break between the oven exit and the slit processing. Further, no wrinkles could be confirmed after passing through the nip roll, and a good stretched film could be obtained.

<Example 5>
In Example 5, a protective film having a width wider than the contact width with respect to one of the rolls (elastic roll) (Tortec 7332K manufactured by Toray Film Co., Ltd., 1500 mm width) was used. Other than that, a slit-processed stretched film was produced in the same manner as in Example 3, and wound into a roll. For Example 5, the same evaluation test as in Example 1 was performed. The evaluation results are shown in Table 1.

  In Example 5, the stretched film did not break during the period from the oven exit to the slit processing. Further, no wrinkles could be confirmed after passing through the nip roll, and a good stretched film could be obtained. At the end of the stretched film, there was a float between the protective film and a bonding failure occurred at the end, but in the 1200 mm wide slit processed stretched film after slit processing, the bonding failure The effect of was not confirmed.

<Comparative Example 1>
In Comparative Example 1, after slitting both ends of the biaxially stretched film after transverse stretching, a protective film was bonded to one surface of the biaxially stretched film. In addition, the slit after bonding a protective film was abbreviate | omitted. Other than that, a slit-processed stretched film was prepared in the same manner as in Example 3, and winding was attempted. Further, Comparative Example 1 was subjected to the same evaluation test as in Example 1. The evaluation results are shown in Table 1.

  In Comparative Example 1, since only the biaxially stretched film was slit, the stretched film was broken before the tension could be stably applied to the stretched film at the start of stretching. Moreover, the tension conditions of the stretched film, the conditions for conveying the end portion after slit processing, etc. are not easily adjusted, and the handling property of the slit processed stretched film was poor.

<Example 6>
In Example 6, an unstretched film having a thickness of 60 μm was used. Other than that, a slit-processed stretched film was prepared in the same manner as in Example 4, and wound into a roll. For Example 6, the same evaluation test as in Example 1 was performed. The evaluation results are shown in Table 1.

  In Example 6, the stretched film was not broken during the period from the oven exit to the slit processing. Moreover, the thickness of the longitudinally stretched film was 46 μm, and the thickness of the laterally stretched film was 22 μm. Generally, when the thickness of the stretched film is reduced, wrinkles are likely to occur. However, even when the thickness of the stretched film is 22 μm, wrinkles did not occur, and a good slit processed stretched film could be obtained.

<Example 7>
In Example 7, the longitudinal stretch ratio was set to 3 times, the transverse stretch ratio was set to 3.5 times, and the longitudinally stretched film was slit at the oven entrance of the lateral stretcher so that the oven exit width of the lateral stretcher was 1400 mm. The width of the longitudinally stretched film to be stretched laterally was adjusted. Other than that, a slit-processed stretched film was prepared in the same manner as in Example 6, and wound into a roll. For Example 7, the same evaluation test as in Example 1 was performed. The evaluation results are shown in Table 1.

  In Example 7, breakage of the stretched film did not occur until the slit processing was performed from the oven exit. Moreover, although the thickness of the stretched film was 9.5 μm, wrinkles did not occur and a good stretched film could be obtained.

<Example 8>
In Example 8, a roll having a 1 mm step between the first roll surface and the second roll surface was disposed as a guide roll immediately before the nip roll. Except that, a slit-processed stretched film was produced in the same manner as in Example 4, and wound into a roll. For Example 8, the same evaluation test as in Example 1 was performed. The evaluation results are shown in Table 1.

  In Example 8, the stretched film did not break during the period from the oven outlet to slitting. Further, no wrinkles could be confirmed after passing through the nip roll, and a good stretched film could be obtained.

  Next, with respect to Examples 1 to 8 and Comparative Example 1, in the process until obtaining the slit processed stretched film, the evaluation tests of “the heel immediately before the nip roll” and “whether the roll can be collected after the slit processing” shown below are performed. went. The evaluation results are summarized in Table 2.

<The ridge just before the nip roll>
The presence or absence of wrinkles generated in the stretched film immediately before the nip roll was visually evaluated. The evaluation criteria are as follows.
A: Generation of wrinkles could not be confirmed.
○: Slight generation was confirmed, but no transfer of wrinkle was observed on the stretched film.
X: Generation of wrinkles was confirmed and transfer of wrinkles was also confirmed on the stretched film.

<Possibility of roll collection after slitting>
It was evaluated whether or not the slit-processed stretched film after the slit process can be wound up continuously for 200 m. The evaluation criteria are as follows.
○: The film could be continuously wound without being broken.
X: Since the film was broken, all of the films could not be continuously wound.

  DESCRIPTION OF SYMBOLS 1 ... Manufacturing apparatus of a stretched film 2 ... Extrusion part 3 ... Stretching part 4 ... 1st bonding part (bonding part) 5 ... 1st cutting part (cutting part) 6 ... 2nd bonding part 7 ... 1st 2 cutting part 8 ... winding part 9 ... oven 10 ... extruder 11a, 11b ... nip roll 12 ... clip row 12a ... clip 13 ... guide roll 13a ... first roll surface 13b ... second roll surface 14 ... nip roll 15 ... guide roll 16 ... shear blade 18 ... guide roll 19 ... nip roll 20 ... guide roll 21 ... shear blade 24 ... winding roll RF ... resin film PF1 ... first protective film (protective film) EF ... stretched film EFc ... slit processing Stretched film PF2 ... Second protective film S ... Contact area

Claims (9)

Stretching step of obtaining a stretched film obtained by stretching the resin film at least in the width direction by widening the distance between the clips while holding both ends of the long belt-shaped resin film with the clips,
In a state where the protective film is superimposed on the stretched film, by passing between a pair of nip rolls, a bonding step of bonding the protective film to the stretched film;
The manufacturing method of the slit process extending | stretching film characterized by including the cutting process of cut | disconnecting the edge part of the said extending | stretching film with the said protective film by slit process in this order. Among the guide rolls that come into contact with the stretched film before the stretched film passes between the pair of nip rolls, the stretched film is stretched at the center of at least one guide roll rather than at both ends of the guide roll. There is a contact area that is easy to contact the part,
2. The method for producing a slit-processed stretched film according to claim 1, wherein the width of the contact region is narrower than the distance between the clips when the gripping by the clips is released.   Of the guide rolls, the guide roll located immediately before the pair of nip rolls is a roll provided with a contact region having a width narrower than the distance between the clips when the gripping by the clips is released. The manufacturing method of the slit process stretched film of Claim 2 characterized by the above-mentioned.   4. The roll according to claim 2, wherein all of the guide rolls are rolls provided with a contact area having a width narrower than a distance between the clips when the gripping by the clips is released. Manufacturing method of slit processed stretched film. The roll provided with the contact region has a first roll surface having a width corresponding to the contact region and both sides in the width direction across the first roll surface, respectively, than the first roll surface. A pair of second roll surfaces having a small outer diameter,
5. The slit-processed stretched film according to claim 2, wherein the pair of second roll surfaces form contact regions that are easy to contact with both ends of the stretched film. Production method.   3. One of the pair of nip rolls is a roll provided with a contact region having a width narrower than a distance between the clips when the gripping by the clip is released. The manufacturing method of the slit process stretched film as described in any one of Claims 5-5.   The slit processing stretching according to claim 6, wherein the roll on the side in contact with the protective film of the pair of nip rolls is a roll provided with a contact region having a width wider than the width of the protective film. A method for producing a film.   After cutting the end portion of the stretched film, a guide roll that comes into contact with the slit-processed stretched film or the protective film after cutting is provided with a contact region having a width wider than the width of the slit-processed stretched film or the protective film. The manufacturing method of the slit process stretched film as described in any one of Claims 1-7 characterized by the above-mentioned. While extending the distance between the clips while holding the both ends of the long belt-shaped resin film with the respective clips, a stretched portion that makes the resin film stretched at least in the width direction, and
By passing between a pair of nip rolls in a state where a protective film is superimposed on the stretched film, a bonding portion for bonding the protective film to the stretched film;
An apparatus for producing a slit-processed stretched film, comprising: a cutting section that cuts an end of the stretched film together with the protective film by slit processing.

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