JP6233921B2 - Laminated film peeling apparatus, laminated film peeling method, and optical film laminate manufacturing method using the same. - Google Patents

Description

  The present invention relates to a laminate film peeling apparatus for peeling a part of a film from a laminate film in which two or more films are laminated, a laminate film peeling method, and an optical film laminate manufacturing method using the same.

  As an apparatus for peeling a laminated film, there is an apparatus for peeling by winding around a sharp peeling edge (see Patent Document 1). However, in this case, a strong force is applied between the film and the leading edge of the peeling edge, and there is a risk of scratching the film surface that contacts the leading edge of the edge. Therefore, the method of preventing the damage to the film side which is originally required by folding the base material side (separator, waste material part) inside can be considered.

  However, depending on the material of the laminated film, there is anisotropy in the peeling force, so there are film materials that require the substrate to be peeled off from the required film by folding the edge of the edge with the required film side inward. To do. Such a film material becomes more prone to problems such as scratches and film breakage. For example, in the case of a thin polarizing film formed on a PET substrate, after the TAC film is bonded to the polarizing film side, the PET substrate is peeled, and the TAC film is bonded to the peeled polarizing film side ( Patent Document 2).

JP-A-2005-298208 Patent No. 4691205

  In the method of wrapping the substrate side around the peeling edge as in Patent Document 1 above and reversing, in order to cleanly remove a part of the film from the laminated film, the radius of curvature R when the film is reversed at the time of peeling is required. It is important to make the size smaller than the amount and keep it stable in the width direction. If this radius of curvature R is small and cannot be kept stable, the residue on the substrate side (the scraped material of the substrate scraped at the edge tip) moves to another film side, or the peeling force becomes too strong. The base film may be broken.

  In addition, if the inverted film and the peeling edge come into contact with each other with a strong force and slip occurs, the inverted film is scratched.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a novel peeling apparatus and a peeling method that enable clean peeling without using a conventional peeling edge. Moreover, it aims at providing the method of manufacturing the optical film laminated body containing a polarizing film using the said peeling apparatus or the peeling method.

The present invention is a laminated film peeling apparatus for peeling a part of a film from a laminated film in which two or more films are laminated,
A first transport unit that has a suction unit and sucks and transports the laminated film to the suction unit;
A facing portion disposed at a predetermined distance from the suction portion at a position facing the suction portion with the laminated film interposed therebetween;
Among the laminated films, the film in contact with the adsorption part is peeled off from the other film by inverting (folding back) the other film while leaving at least the film in contact with the adsorption part. A peeling region in which a point is movably disposed and formed between the suction portion and the facing portion;
A second transport unit that transports the other film in a direction opposite to the traveling direction of the laminated film by the first transport unit.

  According to this configuration, in the peeling region, at least a film (for example, a separator or a resin base material) in contact with the adsorbing portion is left and other films (for example, an optical film, a thin polarizing film, a polarizing film, etc.) are reversed. By causing (folding back), the film that is in contact with the adsorbing portion is peeled from the other film (the point at which such peeling occurs is called the peeling point). As a result, a curved surface (curvature radius R) formed by reversing the peeled film sandwiched between the surfaces of the adsorption part and the opposing part can be forcibly created, and there is no residue. Peeling is possible.

  In the present invention, the “suction portion” is a means for sucking and transporting the laminated film by suction, and examples thereof include a suction belt and a suction plate connected to a vacuum.

  The predetermined interval from the suction portion to the facing portion is 2 mm or more and 20 mm or less, preferably 3 mm or more and 6 mm or less. If the distance is too wide so that the predetermined distance exceeds 20 mm, the peeling angle cannot be obtained and there is a possibility that a residue is generated. If the interval is too narrow such that the predetermined interval is less than 2 mm, handling problems such as film contact may occur. The radius of curvature R is 1 mm or more and 10 mm or less, preferably 1.5 mm or more and 3 mm or less. If the radius of curvature R exceeds 10 mm, the peeling angle cannot be obtained and a residue may be generated as in the case where the predetermined interval E2 is too wide. If the curvature radius R is less than 1 mm, handling problems such as film contact may occur as in the case where the predetermined interval E2 is too narrow.

  As one embodiment of the invention, the facing portion is disposed in parallel to the suction surface of the suction portion.

  As one embodiment of the invention, the facing portion is disposed so as to be non-parallel to the suction surface of the suction portion and along the transport direction of the other film by the second transport portion.

  As one embodiment of the invention, the facing portion is configured to include at least a pair of rolls and a rotatable belt stretched between the pair of rolls. Moreover, it is preferable that the belt has an adsorption hole, and is an adsorption belt that adsorbs and conveys the other film by suction from the adsorption hole. The suction belt is connected to the vacuum. It is preferable to provide both the suction portion and the facing portion with a suction function, since no film transfer deviation occurs and the film surface is not damaged by friction with the facing portion.

  Moreover, as one Embodiment of the said invention, the said opposing part is plate shape. The material of the facing portion is not particularly limited, and examples thereof include a smooth metal material or a resin material having a small surface frictional resistance.

As an embodiment of the above invention,
A detection unit for detecting the peeling point;
A determination unit for determining whether the position of the peeling point detected by the detection unit is within the peeling region or a predetermined range smaller than the peeling region;
And a first speed control unit that controls a film transport speed of the first transport unit and / or a film transport speed of the second transport unit based on a determination result of the determination unit.

  With this configuration, both or one of the film transport speed of the first transport unit and the film transport speed of the second transport unit is controlled so that the peel point exists in the peel region or within a predetermined range. Controlling the transport speed of the laminated film (and the laminated film after part of the film is peeled off) by the first transport section and the transport speed of the other film peeled by the second transport section to the same speed preferable. Further, as the above control method, it is preferable to detect the position of the peeling point, to make one speed constant and to make the other fast or slow so that the peeling point exists in the peeling area or within a predetermined range.

  “Within a predetermined range smaller than the peeling region” is set based on a margin value from the boundary of the peeling region, for example. The margin value can be set from an experimental value or actual operation, and various processing speeds such as a rotation motor that rotates the transport roll, a detection unit, and a speed control unit are also taken into consideration.

  The detection unit includes, for example, one imaging unit that captures an image of a predetermined area, and an image analysis unit that analyzes an image obtained by the imaging unit and recognizes a separation point. Then, the determination unit determines whether or not the position of the recognized peeling point is within the peeling area or a predetermined range. In addition, as a detection unit, for example, two sensors (for example, area, line, point, etc.) are provided at the boundary position of the peeling region or in a narrow range inside the boundary position of the peeling region along the film conveyance direction. It may be arranged. For example, the determination unit determines whether a separation point exists in the separation region or within a predetermined range based on the detection result (ON, OFF) of one of the two sensors.

As an embodiment of the above invention,
A detection unit for detecting the peeling point;
A determination unit for determining whether the position of the peeling point detected by the detection unit is within the peeling region or a predetermined range smaller than the peeling region;
Based on the determination result of the determination unit, one or more of the film conveyance speed of the first conveyance unit, the film conveyance speed of the second conveyance unit, and the rotation speed of the belt of the facing unit are controlled. And a second speed control unit.

  With this configuration, one of the film transport speed of the first transport section, the film transport speed of the second transport section, and the rotational speed of the belt of the facing section so that the peel point exists within the peel area or within a predetermined range. Or two or more are controlled. The transport speed of the laminated film (and the laminated film after a part of the film is peeled off) by the first transport section, the transport speed of the other film peeled by the second transport section, and the rotation speed of the belt of the facing section Are preferably controlled at the same speed.

  Moreover, as one embodiment of the invention, the thickness of the other film transported by the second transport unit is 10 μm or less.

  As one embodiment of the invention, the laminated film includes an optical film.

  Moreover, as one embodiment of the invention, the laminated film includes a polarizing film obtained by stretching at least a resin base material having a polyvinyl alcohol resin layer formed on one surface thereof, and the laminated film having the resin base material. It is.

Another aspect of the present invention is a laminate film peeling method for peeling a part of a film from a laminated film in which two or more films are laminated,
An adsorbing part for adsorbing the laminated film;
A facing portion disposed at a predetermined distance from the suction portion at a position facing the suction portion with the laminated film interposed therebetween;
Among the laminated films, the film in contact with the adsorption part is peeled off from the other film by inverting (folding back) the other film while leaving at least the film in contact with the adsorption part. A point is movably disposed, and has a peeling region formed between the suction part and the facing part,
A first conveying step of adsorbing and conveying the laminated film to the adsorption unit;
In the peeling region, a peeling step of peeling the film in contact with the adsorbing portion from another film,
A second conveying step of conveying the other film in a direction opposite to the traveling direction of the laminated film by the first conveying unit.

  According to this configuration, in the peeling region, at least a film (for example, a separator or a resin base material) in contact with the adsorbing portion is left and other films (for example, an optical film, a thin polarizing film, a polarizing film, etc.) are reversed. By causing (folding back), the film that is in contact with the adsorbing portion is peeled from the other film (the point at which such peeling occurs is called the peeling point). This makes it possible to forcibly create the radius of curvature R formed by reversing the peeled film sandwiched between the respective surfaces of the adsorption part and the opposing part, enabling clean peeling without residue It becomes.

As one embodiment of the invention, a detection step of detecting the peeling point;
A determination step of determining whether or not the position of the peeling point detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region;
A first speed control step of controlling a film transport speed of the first transport step and / or a film transport speed of the second transport step based on a determination result of the determination step.

  With this configuration, both or one of the film transport speed in the first transport process and the film transport speed in the second transport process is controlled so that the peel point exists in the peel area or within a predetermined range. Controlling the transport speed of the laminated film (and the laminated film after a part of the film is peeled off) in the first transport process and the transport speed of the other film peeled off in the second transport process to the same speed. preferable. Further, as the above control method, it is preferable to detect the position of the peeling point, to make one speed constant and to make the other faster or slower so that the peeling point exists in the peeling region or within a predetermined range. .

As one embodiment of the invention, a detection step of detecting the peeling point;
A determination step of determining whether or not the position of the peeling point detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region;
Based on the determination result of the determination step, one or more of the film conveyance speed of the first conveyance step, the film conveyance speed of the second conveyance step, and the rotation speed of the belt constituting the facing portion. And a second speed control step for controlling.

  With this configuration, one of the film conveyance speed in the first conveyance process, the film conveyance speed in the second conveyance process, and the rotation speed of the belt in the opposite portion so that the separation point exists in the separation region or within a predetermined range. Or two or more are controlled. The transport speed of the laminated film (and the laminated film after part of the film is peeled off) in the first transport process, the transport speed of the other film peeled off in the second transport process, and the rotation speed of the belt in the facing portion Are preferably controlled at the same speed.

In addition, the present invention
A polarizing film forming step of forming a polarizing film on the resin base material by stretching at least a resin base material having a polyvinyl alcohol-based resin layer formed on one surface;
A peeling step of peeling the polarizing film from the resin substrate;
A laminate production step of obtaining an optical film laminate by laminating an optical film and / or a protective film directly or via an adhesive layer on the polarizing film peeled off from the resin substrate,
The said peeling process is a manufacturing method of the optical film laminated body characterized by peeling the said polarizing film from the said resin base material using the said peeling apparatus or the said peeling method.

  According to this configuration, the thin polarizing film can be neatly peeled from the base material, and thus an optical film laminate including the thin polarizing film can be suitably produced.

  As one embodiment of the invention, the polarizing film has a thickness of 10 μm or less.

It is the schematic of the peeling apparatus of Embodiment 1. It is a figure which shows another example of an opposing part. It is a figure which shows another example of a detection part.

(Embodiment 1)
Hereinafter, the peeling apparatus of Embodiment 1 will be described with reference to FIG. The peeling apparatus 1 peels a part of the film (11) from the laminated film 10 in which the two layers of films (11, 12) are laminated.

  Although the two-layer film which comprises the laminated | multilayer film 10 is not restrict | limited in particular, For example, containing an optical film is illustrated. Further, for example, the laminated film 10 is a laminated film formed by stretching a resin base material having a polyvinyl alcohol resin layer formed on one side thereof and forming a polarizing film on the resin base material.

  As an optical film which comprises the laminated | multilayer film 10, a polarizing film is mentioned, for example. The film body of the polarizing film is, for example, a polarizer (thickness is generally about 1 to 80 μm) and a polarizer protective film (thickness is generally about 1 to 500 μm) attached to one or both sides of the polarizer. Formed without an agent or adhesive. A polarizer usually has an absorption axis in the stretching direction. Examples of the optical film include retardation films such as λ / 4 plates and λ / 2 plates, viewing angle compensation films, brightness enhancement films, and surface protection films.

  Of the laminated film 10, the thickness of the optical film peeled from the carrier film (resin base material) is preferably 90 μm or less, more preferably 50 μm or less.

  The pressure-sensitive adhesive is not particularly limited, and examples thereof include an acrylic pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, and a urethane pressure-sensitive adhesive. The layer thickness of the pressure-sensitive adhesive is preferably in the range of 10 μm to 50 μm, for example.

(Carrier film)
As a carrier film constituting a part of the laminated film 10, a conventionally known film such as a plastic film (for example, a polyethylene terephthalate film, a polyolefin film, etc.) can be used. In addition, if necessary, an appropriate material according to the prior art such as a silicone-based, long-chain alkyl-based, fluorine-based or molybdenum sulfide-coated material may be used. The carrier film is generally called a release film (separator film).

  The peeling apparatus 1 has a suction part (suction belt 25), a first transport part (driving roll 21, driven roll 22) that transports the suction part (suction belt 25) by adsorbing the laminated film 10, and a laminated film. 10. Opposing portions (driving roll 41, driven roll 42, suction belt 45) arranged at a predetermined distance E2 from the suction portion (suction belt 25) at a position facing the suction portion (suction belt 25) with 10 therebetween. Then, in the laminated film 10, the film (carrier film 12) that is in contact with the suction part (suction belt 25) is left and the other film (optical film 11) is reversed (turned back). The peeling point P where the film (carrier film 12) in contact with the (adsorption belt 25) is separated from the other film (optical film 11) is movably disposed, and the adsorption portion (absorption The separation region (E1, E2, E3) formed between the belt 25) and the opposing portion (the driving roll 41, the driven roll 42, the suction belt 45), and the first conveying unit (the driving roll 21, the driven roll 22) And a second transport section (nip roll 31, nip roll 32) for transporting another film (optical film 11) in a direction opposite to the traveling direction of the laminated film 10.

  In the first embodiment, the suction unit has a suction belt 25, and the suction belt 25 sucks and conveys the laminated film 10 by sucking the carrier film 12 side. The suction belt 25 has suction holes (not shown) and sucks and conveys the film (carrier film 12) by suction from the suction holes. The suction belt 25 is connected to a vacuum (not shown).

  The first transport unit has a drive roll 21 and a driven roll 22, and has a structure in which a suction belt 25 is stretched over them (a structure in which a belt is stretched between rolls). In addition, the first transport unit may be provided with a nip roll, a transport roll, and the like. The drive roll 21 is driven and controlled by a control unit 60 described later in conjunction with a motor (not shown).

  The facing portion is disposed at a position facing the suction belt 25 with the laminated film 10 interposed therebetween with a predetermined interval E2 from the suction belt 25. The facing portion has a drive roll 41 and a driven roll 42, and has a structure in which a suction belt 45 is stretched over them (a structure in which a belt is stretched between rolls). The drive roll 41 is driven and controlled by a control unit 60 described later in conjunction with a motor (not shown). The suction belt 45 has suction holes (not shown), and sucks and transports another film (optical film 11) by suction from the suction holes. The suction belt 45 is connected to a vacuum (not shown).

  The predetermined distance E2 from the suction surface of the suction belt 25 to the suction surface of the suction belt at the opposite portion is 2 mm or more and 20 mm or less, preferably 3 mm or more and 6 mm or less.

  In FIG. 1, the suction surface of the suction belt 45 at the opposing portion is arranged in parallel to the suction surface of the suction belt 25. However, as another embodiment, the suction surface of the suction belt 45 of the opposing portion is arranged non-parallel to the suction surface of the suction belt 25 (inclination angle α), and another film (optical film) by the second transport unit 11) may be arranged along the transport direction. For example, the inclination angle α is shown in FIG. The inclination angle α is in the range of more than 0 ° and less than 89 °, preferably more than 0 ° and less than 60 °, more preferably more than 0 ° and less than 30 °, still more preferably more than 0 ° and less than 20 °. is there. In FIG. 2, the predetermined interval E2 depends on the roll arrangement and ranges from E2a to E2b. In this case, E2a and E2b are 2 mm or more and 20 mm or less, preferably 3 mm or more and 6 mm or less, and E2a <E2b It is a relationship.

  The height direction (upward and downward in FIG. 1 paper surface) of the peeling area (area composed of E1 or E3, E2) is a predetermined interval E2 from the suction belt 25 to the suction belt 45. In addition, the reversal portion X of the optical film 11 that has been peeled and reversed (or the peeling point P, which is a position where the optical film 11 is peeled off from another member when it is reversed) moves in the left-right direction (FIG. 1 The distance E1 from the contact point between the outer periphery of the drive roll 21 and the suction belt 25 of the first transport unit to the contact point between the outer periphery of the driven roll 22 and the suction belt 25, or the drive roll of the opposite part. The distance E3 (in the case of FIG. 1) from the outer periphery of 41 and the contact point of the suction belt 45 to the contact point of the outer periphery of the driven roller 42 and the contact point of the suction belt 45, whichever is shorter. The position where the optical film 11 first contacts the suction belt 45 at the opposite portion is called a contact point Q. In the case of FIG. 1, since the suction belts 25 and 45 are arranged in parallel, the contact point Q and the peeling point P coincide with each other in the vertical direction (overlap). On the other hand, in the case of FIG. 2, since the suction belt 45 is inclined with respect to the suction belt 25, the contact point Q and the peeling point P are slightly shifted in the vertical direction.

  In the peeling area, the other film (optical film 11) is reversed (turned back) while leaving the film (carrier film 12) in contact with the suction belt 25 out of the laminated film 10, so that the suction belt The film (carrier film 12) in contact with 25 is peeled off from the other film (optical film 11). This peeling position is the peeling point P described above. As will be described later, by controlling the rotational speed of each drive roll, the separation point P is present in the separation region and does not move outside the separation region.

  The curvature radius R of the optical film 11 peeled off from the carrier film 12 is 1 mm or more and 10 mm or less, preferably 1.5 mm or more and 3 mm or less. If the radius of curvature R exceeds 10 mm, the predetermined distance E2 is too wide, so that a peeling angle cannot be obtained and there is a possibility that a residue is generated. If the radius of curvature R is less than 1 mm, the predetermined distance E2 is too narrow, which may cause handling problems such as film contact.

  The second transport unit includes a nip roll 31 and a nip roll 32, and the other transported in the peeling region in the direction opposite to the traveling direction of the laminated film 10 by the first transport unit (the driving roll 21 and the driven roll 22). A film (optical film 11) is conveyed.

  The controller 60 controls the rotational speed of each drive roll so that the separation point P exists in the separation region (E1 or E3, E2) and does not move outside the separation region. Specifically, the detection unit 51 detects the peeling point P. The detection unit 51 is arranged perpendicular to the paper surface of FIG. 1 and detects the position of the peeling point P. The detection unit 51 has one image pickup unit that picks up a predetermined area including at least the peeling area, and an image obtained by the image pickup unit is sent to the control unit 60, and the image analysis unit 61 analyzes the image. To recognize the position of the peeling point P.

  The determination unit 62 determines whether or not the position of the peeling point P is within the peeling area or within a predetermined range smaller than the peeling area (a distance shorter than E1 or a distance shorter than E3).

  Based on the determination result of the determination unit 62, the second speed control unit 64 is one of the film transport speed of the first transport unit, the film transport speed of the second transport unit, and the rotational speed of the suction belt 45 of the opposing unit. Control one or more. The “film transport speed of the first transport unit” corresponds to the rotational speed (angular speed) of the drive roll 21. The “film transport speed of the second transport unit” corresponds to the rotational speed (angular speed) of the nip roll 31 and / or the nip roll 32. The “rotational speed of the suction belt 45 at the opposing portion” corresponds to the rotational speed (angular speed) of the drive roll 41 that rotationally drives the suction belt 45. The second speed control unit 64 sets the rotational speed (angular speed) of the drive roll 21, the rotational speeds (angular speed) of the nip rolls 31 and 32, and the rotational speed (angular speed) of the drive roll 41 that drives the suction belt 45 to the same speed. It is preferable to control. As another control method, the position of the peeling point P is detected, and the rotational speed (angular velocity) of the drive roll 21 and the suction belt 45 are adjusted so that the peeling point P exists within the peeling area or within a predetermined range. It is preferable that the rotational speed (angular speed) of the driving roll 41 to be driven is at least constant.

  The control unit 60 may be realized by a cooperative action between a software program and a hardware resource such as a CPU and a memory. In this case, a memory is stored in advance for the program software, processing procedure, various settings, and the like. The control unit 60 can be configured by a dedicated circuit, firmware, an information processing device, or the like.

(Another embodiment)
Although the said opposing part was comprised with the belt which adsorb | sucks and rotates, it is not restrict | limited to this, For example, you may be comprised as a rotating belt.

  As another embodiment, as shown in FIG. 3, the detection unit 51 has at least one detection unit 51 (at least two) at the boundary of the peeling region (inner and outer boundary positions of E1 or E3) along the film conveyance direction. As described above, at least one (at least two) sensors are arranged in a range narrower than the boundary between the line sensors 54 and 55 or the separation region. Based on the detection result (ON, OFF) of one of the two line sensors 54 and 55, the determination unit 62 determines whether or not the separation point P exists within the separation region or within a predetermined range.

  Moreover, as another embodiment, an opposing part is plate shape. The plate-like counter part may be arranged with an inclination angle α as shown in FIG. 2, or may be arranged in parallel with the suction surface of the suction belt 25 as shown in FIG. . The material of the facing portion is not particularly limited, and examples thereof include a smooth metal material or a resin material having a small surface frictional resistance.

  Moreover, as another embodiment, when the facing portion is not a rotating belt, the first speed control unit 63 has a separation point P in the separation region or within a predetermined range based on the determination result of the determination unit 62, for example. As described above, both or one of the film transport speed of the first transport section and the film transport speed of the second transport section is controlled. The first speed control unit 63 preferably controls the rotational speed (angular speed) of the drive roll 21 and the rotational speed (angular speed) of the nip roll 31 and / or the nip roll 32 to the same speed. As another control method, the position of the peeling point P is detected, and one speed is made constant and the other is made faster or slower so that the peeling point P exists within the peeling region or within a predetermined range.

(Peeling method)
The peeling method of the peeling device 1 includes an adsorption belt 25 that adsorbs the laminated film 10 and an opposing portion that is arranged at a predetermined distance E2 from the adsorption portion at a position facing the adsorption portion with the laminated film 10 interposed therebetween. The suction belt 45 and the other film (optical film 11) are reversed (turned back) while leaving at least the film (carrier film 12) in contact with the suction belt 25 of the laminated film 10 so that the suction belt 45 is reversed. 25 between the suction belt 25 and the suction belt 45 at the opposing portion, and a peeling point P at which the film (carrier film 12) in contact with 25 is peeled from the other film (optical film 12) is movably disposed. A separation region (E1 or E3, E2) to be formed, a first conveying step of adsorbing and conveying the laminated film 10 to the adsorption belt 25, and a separation region (E1 or E1). E3 and E2), which are opposite to the direction of travel of the laminated film 10 by the first transport unit and the peeling process of peeling the film (carrier film 12) in contact with the suction belt 25 from the other film (optical film 11). And a second transport step for transporting another film (optical film 11) in the direction.

  The peeling method includes a detection step of detecting the peeling point P, and a determination step of determining whether or not the position of the peeling point P detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region. And one or more of the film transport speed of the first transport process, the film transport speed of the second transport process, and the rotation speed of the suction belt 45 constituting the facing portion based on the determination result of the determination process. And a second speed control step for controlling.

  As another example of the peeling method, a detection step of detecting the peeling point P, and whether or not the position of the peeling point P detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region. It further includes a determination step of determining, and a first speed control step of controlling the film conveyance speed of the first conveyance step and / or the film conveyance speed of the second conveyance step based on the determination result of the determination step.

(Embodiment 2)
The manufacturing method of the optical film laminated body of Embodiment 2 includes the following processes. This production method includes a polarizing film forming step in which a polarizing film is formed on a resin substrate by stretching at least a resin substrate on which a polyvinyl alcohol-based resin layer is formed on one side, and a peeling process for peeling the polarizing film from the resin substrate. And a laminate production step of obtaining an optical film laminate by laminating an optical film and / or a protective film directly or via an adhesive layer on the polarizing film peeled from the resin substrate. The polarizing film forming step corresponds to the preceding step in FIG.

(Polarization film forming process)
The method for forming the polyvinyl alcohol-based resin layer on the resin base material is, for example, by applying a coating liquid containing a polyvinyl alcohol-based resin (PVA-based resin) on a long resin base material (forming a coating film) and then drying. Can be formed.

  An example of the resin base material is a thermoplastic resin. Examples of thermoplastic resins include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. Can be mentioned. As these thermoplastic resins, norbornene resins and amorphous polyethylene terephthalate resins are preferable.

  When the underwater stretching method is used as the stretching, the resin base material absorbs water and plasticizes by exhibiting a plasticizer-like action. In this case, the water absorption rate of the resin base material is 0.2% or more, preferably 0.3% or more, and 3.0% or less, preferably 1.0% or less. The water absorption is determined according to JIS K 7209.

  As for the glass transition temperature (Tg) of the said resin base material, 170 degrees C or less is preferable. Thereby, the stretchability of the resin base material can be sufficiently ensured while suppressing the crystallization of the PVA-based resin layer. In the case of stretching in water, the temperature is preferably 120 ° C. or lower, more preferably 60 ° C. or lower. A glass transition temperature (Tg) is calculated | required according to JISK7121.

  The thickness before stretching of the resin base material is 20 μm to 300 μm, preferably 50 μm to 200 μm. If it is less than 20 μm, it may be difficult to form a PVA resin layer. When it exceeds 300 μm, for example, it takes a long time for the resin base material to absorb water in stretching in water, and an excessive load may be required for stretching.

  Examples of the PVA-based resin include polyvinyl alcohol and ethylene-vinyl alcohol copolymer.

  Examples of the solvent for the coating solution include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylolpropane, and amines such as ethylenediamine and diethylenetriamine. . These can be used alone or in combination of two or more. The concentration of the PVA resin in the solution is 3 to 20 parts by weight with respect to 100 parts by weight of the solvent. If it is this resin density | concentration, the uniform coating film closely_contact | adhered to the resin base material can be formed.

  You may mix | blend an additive with the said coating liquid. Examples of the additive include a plasticizer, a surfactant, and an easy adhesion component. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol and glycerin. Examples of the surfactant include nonionic surfactants. As the easily adhesive component, for example, modified PVA such as acetoacetyl-modified PVA is used.

  Examples of the coating method of the coating solution include a roll coating method, a spin coating method, a wire barcode method, a dip coating method, a die coating method, a curtain coating method, a spray coating method, a knife coating method (comma coating method, etc.) and the like. It is done.

  The coating step of the coating solution is preferably 50 ° C. or higher. The drying step after the coating step is preferably 50 ° C. or higher. Application and drying of the coating solution may be performed in the same step.

  The thickness of the PVA-based resin layer after drying and before stretching is 3 μm to 40 μm, preferably 5 μm to 20 μm.

  Before forming the PVA-based resin layer, the resin base material may be subjected to surface treatment (for example, corona treatment), or an easy-adhesion layer may be formed on the resin base material. As a material constituting the easy-adhesion layer, for example, an acrylic resin, a polyvinyl alcohol resin, or the like is used, and a polyvinyl alcohol resin is preferable. As for the thickness of an easily bonding layer, 0.05 micrometer-1 micrometer are preferable. By performing the said process, the adhesiveness of a resin base material and a PVA-type resin layer can be improved.

  Examples of the stretching method include fixed end stretching and free end stretching. The free end stretching is, for example, a method of stretching uniaxially through a resin base material in which a long PVA resin layer is formed between rolls having different peripheral speeds (a method of stretching in the longitudinal direction). Moreover, it is the method of extending | stretching in the width direction with respect to the resin base material in which the elongate PVA resin layer was formed.

  Examples of the stretching method include an air stretching method and an underwater stretching method, and an underwater stretching method is preferable. Further, the stretching may be performed once or multistage stretching may be performed. In the case of multistage stretching, free end stretching and fixed end stretching may be combined, or an air stretching method and an underwater stretching method may be combined. In the case of multiple stages, the draw ratio (maximum draw ratio) is the product of the draw ratios at each stage.

  In the case of the air stretching method, the stretching temperature is preferably not less than the glass transition temperature (Tg) of the resin substrate, more preferably not less than Tg + 10 ° C., and still more preferably not less than Tg + 15 ° C.

  In the case of the underwater stretching method, the temperature of the stretching bath is preferably 40 ° C to 85 ° C, more preferably 50 ° C to 85 ° C. The immersion period of the drawing bath is 15 seconds to 5 minutes.

  It is preferable to add boric acid or borate to the stretching bath. The boric acid concentration in the stretching bath is 1 to 10 parts by weight with respect to 100 parts by weight of water. Examples of alternatives to boric acid include boron compounds such as borax, glyoxal, and glutaraldehyde.

  In the dyeing process described later, when a dichroic substance (for example, iodine) is adsorbed on the PVA-based resin layer, it is preferable to add an iodide to the stretching bath. Thereby, elution of the iodine adsorbed on the PVA resin layer can be suppressed. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, and titanium iodide. The concentration of iodide is 0.05 to 15 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of water.

  The stretch ratio (maximum stretch ratio) of the resin base material is 5.0 times or more with respect to that before stretching. In this embodiment, the “maximum draw ratio” is a value 0.2 lower than the draw ratio immediately before the resin base material breaks.

  As an embodiment in which the stretching is performed in multiple stages, after stretching in the air at a high temperature (for example, 95 ° C. or higher), stretching in the boric acid solution is performed, and dyeing described later is performed. In this case, the draw ratio of the air drawing is 3.5 times or less. The stretching temperature in the air stretching is preferably equal to or higher than the glass transition temperature (Tg) of the PVA resin, and is, for example, 95 ° C to 150 ° C. The maximum draw ratio in the air drawing and the boric acid aqueous drawing is 5.0 times or more, preferably 5.5 times or more, more preferably 6.0 times or more with respect to that before drawing.

  The dyeing is a treatment for adsorbing a dichroic substance (preferably iodine) on the PVA resin layer. As an adsorption method, for example, a method of immersing a PVA-based resin layer (resin base material) in a staining solution containing iodine, a method of applying the staining solution to the PVA-based resin layer, and a method of spraying the staining solution onto the PVA-based resin layer Etc.

  The staining solution is an aqueous iodine solution. The compounding solution of iodine is 0.1 to 0.5 part by weight with respect to 100 parts by weight of water. In order to suppress dissolution of the PVA resin, the liquid temperature at the time of dyeing the staining liquid is, for example, 20 ° C. to 50 ° C. The immersion time is, for example, 5 seconds to 5 minutes in order to ensure the transmittance of the PVA resin. The dyeing treatment is preferably performed before the underwater stretching when the above-described underwater stretching is performed.

(Other processing)
In addition to stretching and dyeing, for example, an insolubilization process, a crosslinking process, a washing process, and a drying process may be performed as a process for turning the PVA resin layer into a polarizing film.

  The insolubilization process is a process of immersing the PVA resin layer (resin base material) in an aqueous boric acid solution. This treatment can impart water resistance to the PVA resin layer. The concentration of the boric acid aqueous solution is 1 to 4 parts by weight with respect to 100 parts by weight of water. The liquid temperature of the insolubilization bath is, for example, 20 ° C to 50 ° C. The insolubilization treatment is preferably performed before the above-described stretching in water and the above-mentioned dyeing treatment.

  The crosslinking treatment is a treatment of immersing the PVA resin layer (resin base material) in the boric acid aqueous solution. This treatment can impart water resistance to the PVA resin layer. The concentration of the boric acid aqueous solution is 1 to 5 parts by weight with respect to 100 parts by weight of water. When the crosslinking treatment is performed after the dyeing treatment, it is preferable to further add an iodide. By blending iodide, elution of iodine adsorbed on the PVA resin layer can be suppressed. The compounding quantity of the iodide is 1 weight part-5 weight part with respect to 100 weight part of water. The liquid temperature of the crosslinking bath is, for example, 20 ° C to 60 ° C. The crosslinking treatment is preferably performed before the above-described stretching in water. It is preferable to perform a dyeing process, a crosslinking process, and stretching in water in this order.

  The cleaning process is a process of immersing the PVA resin layer (resin base material) in an aqueous potassium iodide solution. The drying temperature in the drying process is, for example, 30 ° C to 100 ° C.

(Polarizing film)
The polarizing film is a PVA resin film in which a dichroic substance is adsorbed and oriented. The upper limit of the thickness of the polarizing film is 25 μm or less, preferably 15 μm or less, more preferably 10 μm or less, still more preferably 7 μm or less, and particularly preferably 5 μm or less. The lower limit is 0.5 μm or more, preferably 1.5 μm or more. is there. The polarizing film exhibits absorption dichroism at any wavelength between 380 nm and 780 nm. The single transmittance of the polarizing film is 40.0% or more, preferably 41.0% or more, more preferably 42.0% or more, and further preferably 43.0% or more. The polarization degree of the polarizing film is 99.8% or more, preferably 99.9% or more, more preferably 99.95% or more.

(Peeling process)
The peeling step includes an adsorption belt 25 that adsorbs the laminated film 10, and an adsorption belt 45 that is disposed at a position facing the adsorption portion with the laminated film 10 interposed therebetween with a predetermined distance E2 from the adsorption portion. In the laminated film 10, the at least one resin base film (carrier film 12) in contact with the suction belt 25 is left and the other film (polarizing film 11) is reversed (turned back), thereby the suction belt. The peeling point P where the film of the resin base material (carrier film 12) in contact with 25 is peeled from the other film (polarizing film 11) is movably arranged, and the suction belt 45 opposite to the suction belt 25. A separation region (E1 or E3, E2) formed between the first film and the first conveyance step of adsorbing and transporting the laminated film 10 to the adsorption belt 25, and a separation region (E1 or E3). In E2), the peeling process of peeling the resin base film (carrier film 12) in contact with the suction belt 25 from the other film (polarizing film 11), and the traveling direction of the laminated film 10 by the first transport unit A second transporting step of transporting another film (polarizing film 11) in the reverse direction.

  The peeling step includes a detection step for detecting the peeling point P, and a determination step for determining whether or not the position of the peeling point P detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region. And one or more of the film transport speed of the first transport process, the film transport speed of the second transport process, and the rotation speed of the suction belt 45 constituting the facing portion based on the determination result of the determination process. And a second speed control step for controlling.

  As another example of the peeling method, a detection step of detecting the peeling point P, and whether or not the position of the peeling point P detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region. It further includes a determination step of determining, and a first speed control step of controlling the film conveyance speed of the first conveyance step and / or the film conveyance speed of the second conveyance step based on the determination result of the determination step.

(Laminate production process)
The laminate production step is a step of obtaining an optical film laminate by laminating an optical film and / or a protective film directly or via an adhesive layer on the polarizing film peeled from the resin substrate in the peeling step.

  Examples of the optical film include retardation films such as λ / 4 plates and λ / 2 plates, viewing angle compensation films, brightness enhancement films, and surface protection films. Examples of the protective film include cellulose resin films such as triacetyl cellulose (TAC), cycloolefin resin films such as norbornene resins, olefin resin films such as polyethylene and polypropylene, and (meth) acrylic resin films. Is mentioned.

  Examples of the adhesive constituting the adhesive layer include a water-based adhesive and a solvent-based adhesive. As the aqueous adhesive, an aqueous adhesive containing a PVA resin is preferable. The thickness at the time of application | coating of an adhesive agent is 10 nm-300 nm, for example, Preferably it is 10 nm-200 nm, More preferably, it is 20 nm-150 nm.

  It is preferable to heat after laminating an optical film and / or a protective film on the polarizing film. The heating temperature is 50 ° C. or higher, preferably 55 ° C. or higher, more preferably 60 ° C. or higher, and still more preferably 80 ° C. or higher.

  As a method of laminating various films on the polarizing film via an adhesive, for example, various films on which an adhesive layer has been previously formed are rotated while the polarizing film is opposed to the adhesive surface and the both are conveyed. It is sandwiched between a pair of rolls (sticking part) and attached (sticking process).

DESCRIPTION OF SYMBOLS 1 Peeling apparatus 10 Laminated | multilayer film 11 Optical film, polarizing film 12 Carrier film 21 Drive film 22 Driven film 25 Adsorption belt 31 Nip roll 32 Nip roll 41 Drive roll 42 Followed roll 45 Adsorption belt 51 Detection part 60 Control part 61 Image analysis part 62 Determination part 63 1st speed control part 64 2nd speed control part
P Peel point
Q Contact point

Claims (14)

A laminated film peeling apparatus for peeling a part of a film from a laminated film in which two or more films are laminated,
A first transport unit that has a suction part formed with a surface , and transports the laminated film by suction on the surface of the suction part;
A facing portion which is formed with a surface, at a position facing the surface of the suction unit in between the laminated film, arranged so that the surface of the opposing portion is opposed by providing a predetermined distance from the suction unit A facing portion to be
Among the laminated film, said leaving at least a film in contact with the surface of the suction unit by inverting the other films, the peeling point where the film in contact with the surface of the suction unit is separated from the other film It is a peeling region that is movably disposed, and a curved surface is formed by reversing the other film that has been peeled, sandwiched between the surfaces of the suction portion and the facing portion. A peeling area;
And a second transport unit that transports the other film in a direction opposite to the traveling direction of the laminated film by the first transport unit.   The peeling apparatus according to claim 1, wherein the facing portion is disposed in parallel to the suction surface of the suction portion.   The peeling apparatus according to claim 1, wherein the peeling unit is arranged non-parallel to the suction surface of the suction unit and is arranged so as to be along a transport direction of the other film by the second transport unit.   The peeling apparatus according to any one of claims 1 to 3, wherein the facing portion includes at least a pair of rolls and a rotatable belt stretched around the pair of rolls.   The peeling apparatus according to claim 4, wherein the belt has an adsorption hole and is an adsorption belt that adsorbs and conveys the other film by suction from the adsorption hole. A detection unit for detecting the peeling point;
A determination unit for determining whether the position of the peeling point detected by the detection unit is within the peeling region or a predetermined range smaller than the peeling region;
The first speed control unit that further controls a film transport speed of the first transport unit and / or a film transport speed of the second transport unit based on a determination result of the determination unit. The peeling apparatus of any one of Claims. A detection unit for detecting the peeling point;
A determination unit for determining whether the position of the peeling point detected by the detection unit is within the peeling region or a predetermined range smaller than the peeling region;
Based on the determination result of the determination unit, one or more of the film conveyance speed of the first conveyance unit, the film conveyance speed of the second conveyance unit, and the rotation speed of the belt of the facing unit are controlled. The peeling apparatus according to claim 4, further comprising a second speed control unit.   The peeling apparatus of any one of Claims 1-7 whose thickness of the said other film conveyed by a said 2nd conveyance part is 50 micrometers or less.   The peeling apparatus according to claim 1, wherein the laminated film includes an optical film.   The laminated film is a laminated film having a polarizing film obtained by stretching at least a resin substrate having a polyvinyl alcohol-based resin layer formed on one surface thereof, and the resin substrate. The peeling apparatus of any one of Claims. A peeling method of a laminated film in which a part of the film is peeled off from a laminated film in which two or more films are laminated,
A suction part having a surface, wherein the suction part adsorbs the laminated film;
It is a facing portion that forms a surface, and is disposed at a position facing the suction portion with the laminated film in between so as to face the surface of the facing portion with a predetermined distance from the suction portion. Opposite part,
Among the laminated film, said leaving at least a film in contact with the surface of the suction unit by inverting the other films, the peeling point where the film in contact with the surface of the suction unit is separated from the other film It is a peeling region that is movably disposed, and a curved surface is formed by reversing the other film that has been peeled, sandwiched between the surfaces of the suction portion and the facing portion. A peeling region, and
A first conveying step of adsorbing and conveying the laminated film to the adsorption unit;
In the peeling region, a peeling step of peeling the film in contact with the adsorbing portion from another film,
A second conveying step of conveying the other film in a direction opposite to the traveling direction of the laminated film by the first conveying unit. A detecting step for detecting the peeling point;
A determination step of determining whether or not the position of the peeling point detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region;
The first speed control step of controlling the film transport speed of the first transport step and / or the film transport speed of the second transport step based on the determination result of the determination step, further comprising: Peeling method. A detecting step for detecting the peeling point;
A determination step of determining whether or not the position of the peeling point detected in the detection step is within the peeling region or a predetermined range smaller than the peeling region;
Based on the determination result of the determination step, one or more of the film conveyance speed of the first conveyance step, the film conveyance speed of the second conveyance step, and the rotation speed of the belt constituting the facing portion. The peeling method according to claim 11, further comprising: a second speed control step for controlling. A polarizing film forming step of forming a polarizing film on the resin base material by stretching at least a resin base material having a polyvinyl alcohol-based resin layer formed on one surface;
A peeling step of peeling the polarizing film from the resin substrate;
A laminate production step of obtaining an optical film laminate by laminating an optical film and / or a protective film directly or via an adhesive layer on the polarizing film peeled off from the resin substrate,
The said peeling process uses the peeling apparatus of any one of the said Claims 1-10, or uses the peeling method of any one of the said Claims 11-13, and the said polarization | polarized-light from the said resin base material. A method for producing an optical film laminate, comprising peeling off a film.