Method for manufacturing end face processing film

Abstract

To provide a method for manufacturing an end face processing film which can suppress positional deviation of a plurality of films included in workpiece, and can accurately and collectively cut end faces of the plurality of films.SOLUTION: A method for manufacturing an end face processing film includes the steps of: arranging workpiece in which a plurality of films are stacked on a lower pressing jig; sandwiching and fixing the workpiece by the lower pressing jig and an upper pressing jig; and cutting the end face of the fixed workpiece. The workpiece includes: a central region including the center of workpiece; a cutting object region which is cut in a cutting step; and a margin region which is positioned between the central region and the cutting object region, when being viewed from a lamination direction. In the step of fixing the workpiece, the pressing tool presses the central region, and does not substantially press the margin region and the cutting object region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing an edge-processed film. [Background technology]

[0002] Resin films are widely used in various industrial products. It is known that such resin films are cut into shapes according to the application, and then the cut surfaces are finished by cutting. For example, a method for manufacturing an edge-processed film has been proposed in which a laminate having multiple films is pressed from both sides in the stacking direction of the laminate by a first contact member and a second contact member to fix the laminate, and the edge of the laminate is processed (see, for example, Patent Document 1). However, in the method for manufacturing an edge-processed film described in Patent Document 1, when the laminate is pressed from both sides in the stacking direction by the first contact member and the second contact member, the films included in the laminate may be shifted in a direction perpendicular to the stacking direction of the laminate. In this case, there is a risk that the accuracy of the edge processing for each of the multiple films will be insufficient. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-11008 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made to solve the above-mentioned conventional problems, and its main objective is to provide a manufacturing method for edge-processed films that can suppress misalignment of multiple films contained in a workpiece and can cut the edge faces of multiple films in a single operation with high precision. [Means for solving the problem]

[0005] [1] A method for manufacturing an edge-processed film according to an embodiment of the present invention includes an arrangement step of arranging a workpiece having a plurality of films stacked on a lower pressing tool; a fixing step of clamping the workpiece between the lower pressing tool and the upper pressing tool to fix the workpiece; and a cutting step of cutting the edge of the fixed workpiece. When viewed from the stacking direction, the workpiece arranged in the arrangement step has a central region including the center of the workpiece, a cutting target region to be cut in the cutting step, and a margin region located between the central region and the cutting target region. In the fixing step, the upper pressing tool presses the central region and does not substantially press the margin region and the cutting target region. [2] In the manufacturing method of the edge processed film described in [1] above, the width of the area to be cut may be 0.1 mm or more and 1.5 mm or less, and the width of the area to be cut and the width of the margin area may satisfy the following formula (1). 0.005≦(L1+L2) / a≦0.15···(1) (In formula (1), a represents the number of layers of film in the workpiece, L1 represents the width of the area to be cut [mm], and L2 represents the width of the margin area [mm].) [3] In the manufacturing method of the edge processed film described in [1] or [2] above, the upper pressing tool may have a contact surface that contacts the central region in the fixing process; and an opposing surface that faces the margin region in the fixing process. [4] In the manufacturing method of the edge processed film described in [3] above, when the workpiece is fixed, the distance between the margin area and the opposing surface in the stacking direction of the workpiece may be 0 mm or more and 1.0 mm or less. [5] In the manufacturing method of the edge processed film described in [3] or [4] above, the distance between the contact surface and the opposing surface in the stacking direction of the workpiece may satisfy the following formula (2). 0.005≦L3 / a≦0.03 (2) (In formula (2), a represents the number of layers of the film in the workpiece, and L3 represents the distance [mm] between the contact surface and the opposing surface in the layering direction of the workpiece.) Effect of the Invention

[0006] According to an embodiment of the present invention, it is possible to suppress misalignment of multiple films included in a workpiece, and to cut the end faces of multiple films in a single operation with high precision. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram for explaining a method for producing an edge-processed film according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the workpiece of FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view of a film provided in the workpiece of FIG. [Figure 4] FIG. 4 is a schematic diagram for explaining a method for producing an edge-processed film according to another embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic diagram for explaining a method for producing an edge-processed film according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments of the present invention will be described, but the present invention is not limited to these embodiments. In addition, in order to clarify the description, the width, thickness, shape, etc. of each part may be shown in a schematic manner compared to the embodiment, but it is merely an example and does not limit the interpretation of the present invention.

[0009] A. Overview of the manufacturing method for edge-processed film FIG. 1 is a schematic diagram for explaining a manufacturing method of an edge-processed film according to one embodiment of the present invention; FIG. 2 is a plan view of the workpiece of FIG. 1; and FIG. 3 is a schematic cross-sectional view of the film provided on the workpiece of FIG. 2.

[0010] The manufacturing method of the edge processed film according to the embodiment of the present invention includes an arrangement step, a fixing step, and a cutting step. In the arrangement step, the work 2, in which a plurality of films 1 are stacked, is arranged on the lower pressing jig 4. The arranged work 2 has, as viewed from the stacking direction, a central region E1 including the center of the work 2; a cutting target region E2 to be cut in the cutting step; and a margin region E3 located between the central region E1 and the cutting target region E2. In the fixing step, the work 2 is sandwiched between the lower pressing jig 4 and the upper pressing jig 3 to fix the work 2. In the fixing step, the upper pressing jig 3 presses the central region E1, and does not substantially press the margin region E3 and the cutting target region E2. In the cutting step, the end face of the fixed work 2 is cut. The present inventors have found that when a workpiece is formed by stacking a plurality of films, the thickness of the workpiece becomes non-uniform due to the cutting of each film during preparation, and have completed the present invention. More specifically, the film is typically prepared by cutting a raw film into a desired shape and size by any appropriate cutting method. An example of the cutting method is a laser. When such films are stacked to form a workpiece, the end of the workpiece may be thicker than the center of the workpiece. In this case, when the upper pressing tool presses the area including the end of the workpiece in the fixing step, the film included in the workpiece may be displaced in a direction perpendicular to the stacking direction, and the end faces of the plurality of films may not be sufficiently cut. In contrast, in the embodiment of the present invention, in the fixing step, the upper pressing jig presses the central region of the workpiece, and does not substantially press the marginal region and the region to be cut of the workpiece. Therefore, even if the thickness (stacking direction dimension) of the marginal region of the workpiece is larger than the thickness (stacking direction dimension) of the central region of the workpiece, it is possible to suppress the positional deviation of the multiple films included in the workpiece, and the end faces of the multiple films can be cut collectively with high accuracy. Therefore, it is possible to manufacture multiple end face processed films with excellent size accuracy collectively.

[0011] The area E2 to be cut of the workpiece 2 is located on the periphery of the workpiece 2. The area E2 to be cut includes at least the area to be actually cut in the cutting process (cutting area). The area E2 to be cut may include, in addition to the cutting area, a safety area for preventing erroneous cutting of the pressing jig by the cutting tool. The safety area is located inside the cutting area. The width of the safety area is, for example, 0.1 mm to 1 mm. In one embodiment, when the upper pressure tool 3 and the lower pressure tool 4 sandwich the workpiece 2 and project them in the stacking direction, the area E2 to be cut of the workpiece 2 is located outside the respective projection surfaces of the upper pressure tool 3 and the lower pressure tool 4 and includes a safety area.

[0012] The width L1 of the cutting target area E2 of the workpiece 2 is the dimension of the cutting target area in the direction perpendicular to the end face of the workpiece, and is the distance from the end face of the workpiece to the margin area. The width L1 of the cutting target area E2 is, for example, 0.1 mm or more, preferably 0.5 mm or more, and, for example, 3.0 mm or less, preferably 1.5 mm or less, more preferably 1.1 mm or less.

[0013] The width L2 of the marginal region E3 of the workpiece 2 is the dimension of the marginal region in a direction perpendicular to the end face of the workpiece, and is the distance from the region to be cut to the central region. The width L2 of the marginal region E3 satisfies, for example, the following formula (I), and preferably satisfies the following formula (II). 0.004≦L2 / a≦0.18 (I) 0.004≦L2 / a≦0.13 (II) (In formulas (I) and (II), a represents the number of layers of film 1 in workpiece 2, and L2 represents the width [mm] of the margin area.) When the widths of the region to be cut and the margin region that are not substantially pressed by the upper pressing tool are within the above-mentioned ranges, displacement of the film during the fixing step can be stably suppressed.

[0014] In one embodiment, in the workpiece 2, the width L1 of the region E2 to be cut and the width L2 of the margin region E3 satisfy the following formula (1). 0.005≦(L1+L2) / a≦0.15···(1) (In formula (1), a represents the number of layers of film in the workpiece, L1 represents the width of the area to be cut [mm], and L2 represents the width of the margin area [mm].) When (L1+L2) / a satisfies the above formula (1), positional deviation of the multiple films included in the workpiece can be suppressed more stably. (L1+L2) / a is preferably 0.008 or more.

[0015] The number of layers of film 1 in work 2 is, for example, 50 or more, preferably 100 or more, more preferably 150 or more, and even more preferably 200 or more, and is, for example, 1,000 or less, preferably 600 or less, more preferably 400 or less, and even more preferably 300 or less.

[0016] In one embodiment, the upper pressing jig 3 has a contact surface 32a that contacts the central region E1 in the fixing process, and an opposing surface 31a that faces the margin region E3 in the fixing process. The opposing surface 31a is located on the opposite side of the workpiece 2 from the contact surface 32a in the stacking direction of the workpiece 2. When the upper pressing jig 3 and the lower pressing jig 4 sandwich the workpiece 2 and project them in the stacking direction, the margin area E3 of the workpiece 2 is typically the area that overlaps with the projection surface of the opposing surface 31a.

[0017] In one embodiment, the distance L3 between the contact surface 32a and the opposing surface 31a in the stacking direction of the workpieces 2 satisfies the following formula (2). 0.005≦L3 / a≦0.03 (2) (In formula (2), a represents the number of layers of the film in the workpiece, and L3 represents the distance [mm] between the contact surface and the opposing surface in the layering direction of the workpiece.) L3 / a is preferably 0.008 or more, more preferably 0.011 or more, and is preferably 0.025 or less, more preferably 0.015 or less. When L3 / a is equal to or greater than the lower limit, pressing of the marginal region by the upper pressing tool can be stably avoided in the fixing step. When L3 / a is equal to or less than the upper limit, flapping of the end of the film included in the workpiece can be suppressed in the cutting step. This improves the size accuracy of the manufactured edge-processed film and suppresses the occurrence of cracks in the edge-processed film.

[0018] The distance L3 between the contact surface 32a and the opposing surface 31a in the stacking direction of the workpieces 2 exceeds 1.0 mm, for example, and is preferably 2.0 mm or more, for example, 5.0 mm or less, preferably 4.0 mm or less, and more preferably 3.5 mm or less. If the distance between the contact surface and the facing surface is equal to or greater than the lower limit, the pressing of the marginal region by the upper pressing tool can be more reliably avoided in the fixing step. If the distance between the contact surface and the facing surface is equal to or less than the upper limit, the fluttering of the end of the film included in the workpiece can be more effectively suppressed in the cutting step. This allows the size precision of the end-face processed film to be further improved, and also makes it possible to more effectively suppress the occurrence of cracks in the end-face processed film.

[0019] When the workpiece 2 is fixed, the opposing surface 31a faces the margin area E3 in the stacking direction of the workpiece 2, and may be in contact with the margin area E3 to an extent that does not substantially press against it, or may be positioned at a distance from the margin area E3. When the workpiece 2 is fixed, the distance between the margin region E3 and the opposing surface 31a in the stacking direction of the workpiece 2 is, for example, 0 mm or more, preferably 0.1 mm or more, and for example, 2.0 mm or less, preferably 1.5 mm or less, more preferably 1.0 mm or less, and even more preferably 0.5 mm or less. If the distance between the margin area and the facing surface is equal to or greater than the lower limit, the pressing of the margin area by the upper pressing tool can be more reliably avoided in the fixing step. If the distance between the margin area and the facing surface is equal to or less than the upper limit, the flapping of the end of the film included in the workpiece can be more reliably suppressed in the cutting step. Therefore, the size accuracy of the end surface processed film can be further improved, and the occurrence of cracks in the end surface processed film can be stably suppressed.

[0020] Each step of the method for producing the edge-processed film will be described in detail below.

[0021] B. Placement process 1, in one embodiment, in the arrangement step, a plurality of films 1 are stacked on a lower pressing jig 4. More specifically, a plurality of films 1 are stacked on the lower pressing jig 4 so that imaginary lines that pass through the centers of the films 1 and are parallel to the thickness direction coincide with each other. As a result, the workpiece 2 having the above-mentioned central region E1, cutting target region E2, and margin region E3 is formed on the lower pressing jig 4. The lower pressing jig 4 may have any appropriate shape. The lower pressing jig 4 typically has a flat surface, and the workpiece 2 is placed on the flat surface. With the workpiece 2 placed on the lower pressing jig 4, the central region E1 and cutting target region E2 of the workpiece 2 are in contact with the lower pressing jig 4, and the cutting target region E2 of the workpiece 2 protrudes from the lower pressing jig 4 in a direction perpendicular to the stacking direction.

[0022] The thickness of the central region E1 of the work 2 may be any appropriate dimension depending on the number of layers of the film 1. The thickness of the central region E1 is, for example, 10 mm or more, preferably 30 mm or more, and is, for example, 200 mm or less, preferably 150 mm or less. The maximum thickness of the margin region E3 is typically equal to or greater than the thickness of the central region E1. When the thickness of the central region E1 is taken as 1, the thickness of the margin region E3 is, for example, equal to or greater than 1.00, preferably greater than 1.00, more preferably equal to or greater than 1.02, and is, for example, equal to or less than 1.15. The area to be cut E2 may have any appropriate thickness.

[0023] The shape of the work 2 seen from the stacking direction is the same as the shape of the film 1 described later. The work 2 shown in Fig. 2 has a rectangular shape seen from the stacking direction. The area of ​​the central region E1 is, for example, 50% or more, preferably 60% or more, and for example, 98% or less, preferably 90% or less, of the total area of ​​the central region E1, the region to be cut E2, and the margin region E3. The area of ​​the central region E1 is specifically 2,000 mm 2 More than 6,000mm, preferably 2 For example, 500,000 mm 2 Less than 300,000 mm, preferably 2 The following is the result. As long as the cutting target region E2 has the above-mentioned width L1, its area can be set arbitrarily and appropriately. As long as the margin area E3 has the above-mentioned width L2, its area can be set arbitrarily and appropriately.

[0024] B-1. Film details Next, the film 1 used for the workpiece 2 will be described in detail. The film 1 may have any suitable shape. The film shape is typically a polygon, preferably a square, and more preferably a rectangle. When the film is rectangular, the length of the long side is typically 50 mm or more and 1000 mm or less, and the length of the short side is typically 30 mm or more and 550 mm or less.

[0025] Any appropriate configuration may be adopted for the film 1. In one embodiment, the film 1 is a laminated film in which a plurality of films (layers) are laminated. As shown in Figure 3, in one embodiment, film 1 is an optical laminate comprising a polarizing plate 11 including a polarizer 15; a surface protection film 12 attached to the polarizing plate 11; an adhesive layer 13 laminated on the side of the polarizing plate 11 opposite the surface protection film 12; and a release liner 14 attached to the adhesive layer 13. The total thickness of the film 1 is, for example, 50 μm or more, preferably 100 μm or more, and is, for example, 800 μm or less, preferably 500 μm or less.

[0026] B-1-1. Polarizing plate Any appropriate polarizer can be adopted as the polarizer 15. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

[0027] Specific examples of polarizers made of a single-layer resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films that have been dyed with a dichroic substance such as iodine or a dichroic dye and stretched, and polyene-based oriented films such as dehydrated PVA films and dehydrochlorinated polyvinyl chloride films. A polarizer obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferable because of its excellent optical properties.

[0028] The dyeing with iodine is carried out, for example, by immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment, or may be carried out while dyeing. Alternatively, the film may be stretched and then dyed. If necessary, the PVA-based film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, or the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, it is possible to wash off dirt and antiblocking agents on the surface of the PVA-based film, and also to swell the PVA-based film and prevent uneven dyeing.

[0029] Specific examples of polarizers obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate. A polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced by, for example, applying a PVA-based resin solution to the resin substrate and drying the resin substrate to form a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer into a polarizer. In one embodiment of the present invention, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin substrate. The stretching typically includes immersing the laminate in an aqueous boric acid solution to stretch it. Furthermore, the stretching may further include, as necessary, stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in the aqueous boric acid solution. In addition, in one embodiment of the present invention, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being transported in the longitudinal direction to shrink the laminate by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an air-assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment in this order. By introducing the auxiliary stretching, even when PVA is applied onto a thermoplastic resin, it is possible to increase the crystallinity of PVA, and to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, problems such as a decrease in the orientation of PVA or dissolution when immersed in water in the subsequent dyeing step or stretching step can be prevented, and high optical properties can be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in the orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide. This can improve the optical properties of a polarizer obtained through a treatment step in which the laminate is immersed in a liquid, such as a dyeing treatment and an underwater stretching treatment. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through drying shrinkage treatment.The obtained laminate of resin substrate / polarizer may be used as it is (i.e., the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the laminate of resin substrate / polarizer, and any suitable protective layer may be laminated on the peeled surface depending on the purpose. Details of the method for producing such a polarizer are described in, for example, JP2012-73580A and JP6470455A. The entire disclosures of these publications are incorporated herein by reference.

[0030] The thickness of the polarizer is, for example, 1 μm to 80 μm, preferably 1 μm to 15 μm, more preferably 1 μm to 12 μm, further preferably 3 μm to 12 μm, and particularly preferably 3 μm to 8 μm. If the thickness of the polarizer is within this range, curling during heating can be well suppressed, and good appearance durability during heating can be obtained.

[0031] The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more.

[0032] B-1-2.Protective layer The polarizing plate 1 may include a protective layer 16 in addition to the polarizer 15. The protective layer 16 is provided on at least one surface of the polarizer 15. In the illustrated example, the protective layer 16 is provided on both surfaces of the polarizer 15. The protective layer 16 is typically attached to the polarizer 15 via any appropriate adhesive layer (not shown).

[0033] The protective layer is formed of any suitable film that can be used as a protective layer for a polarizer. Specific examples of materials that are the main components of the film include cycloolefin (COP) resins such as polynorbornene resins, polyester resins such as polyethylene terephthalate (PET) resins, cellulose resins such as triacetyl cellulose (TAC), transparent resins such as polycarbonate (PC), (meth)acrylic resins, polyvinyl alcohol resins, polyamides, polyimides, polyethersulfones, polysulfones, polystyrenes, polyolefins, and acetate resins. In addition, thermosetting resins or ultraviolet curing resins such as (meth)acrylic resins, urethane resins, (meth)acrylic urethane resins, epoxy resins, and silicone resins are also included. Note that "(meth)acrylic resin" refers to acrylic resins and / or methacrylic resins. In addition, glassy polymers such as siloxane polymers are also included. In addition, the polymer films described in JP 2001-343529 A (WO01 / 37007) can also be used. The material of this film can be, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain, such as a resin composition having an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extrusion molded product of the above resin composition. The materials of the resin film can be used alone or in combination.

[0034] The thickness of the protective layer is preferably 1 mm or less, more preferably 1 μm to 500 μm, and further preferably 5 μm to 150 μm.

[0035] B-1-3. Surface protection film In the illustrated example, the surface protective film 12 is attached to the protective layer 16 of the polarizing plate 11. The surface protective film 12 typically includes a substrate and an adhesive layer. Examples of materials for the substrate include the same resins as those constituting the protective layer 16. The adhesive layer attaches the substrate of the surface protective film 12 to the protective layer 16. The adhesive layer may be made of any appropriate adhesive. The adhesive layer of the surface protective film 12 may be configured in the same manner as the adhesive layer 13 described below.

[0036] The total thickness of the surface protective film 12 is, for example, 20 μm or more, preferably 40 μm or more, and is, for example, 90 μm or less, preferably 70 μm or less.

[0037] B-1-4.Adhesive layer The adhesive layer 13 is located on the opposite side of the polarizing plate 11 from the surface protective film 12. In the illustrated example, the adhesive layer 13 is laminated on the surface of the protective layer 16.

[0038] The pressure-sensitive adhesive layer 13 preferably has a storage modulus at 25° C. of 1.0×10 4 Pa~1.0×10 6 Pa, more preferably 1.0×10 4 Pa~1.0×10 5 When the storage modulus of the pressure-sensitive adhesive layer is within such a range, chipping of the pressure-sensitive adhesive layer during the cutting step can be stably suppressed.

[0039] The adhesive layer 13 is composed of an adhesive. Any suitable adhesive may be used. Specific examples of adhesives constituting the adhesive layer include acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, epoxy adhesives, and polyether adhesives. By adjusting the type, number, combination, and compounding ratio of monomers forming the base resin of the adhesive, as well as the compounding amount of the crosslinking agent, reaction temperature, reaction time, and the like, an adhesive having desired properties according to the purpose can be prepared. The base resin of the adhesive may be used alone or in combination of two or more. From the viewpoints of transparency, processability, durability, and the like, an acrylic adhesive (acrylic adhesive composition) is preferred. The acrylic adhesive composition typically contains a (meth)acrylic polymer as a main component. The (meth)acrylic polymer may be contained in the adhesive composition at a ratio of, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more of the solid content of the adhesive composition. The (meth)acrylic polymer contains alkyl (meth)acrylate as a main component as a monomer unit. Here, (meth)acrylate refers to acrylate and / or methacrylate. The alkyl (meth)acrylate may be contained in a proportion of preferably 80% by mass or more, more preferably 90% by mass or more, in the monomer components forming the (meth)acrylic polymer. Examples of the alkyl group of the alkyl (meth)acrylate include linear or branched alkyl groups having 1 to 18 carbon atoms. The average number of carbon atoms in the alkyl group is preferably 3 to 9, more preferably 3 to 6. A preferred alkyl (meth)acrylate is butyl acrylate. Examples of monomers (copolymerizable monomers) constituting the (meth)acrylic polymer include, in addition to alkyl (meth)acrylates, carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, aromatic ring-containing (meth)acrylates, and heterocycle-containing vinyl monomers. Representative examples of copolymerizable monomers include acrylic acid, 4-hydroxybutyl acrylate, phenoxyethyl acrylate, and N-vinyl-2-pyrrolidone.The acrylic adhesive composition may preferably contain a silane coupling agent and / or a crosslinking agent. Examples of the silane coupling agent include an epoxy group-containing silane coupling agent. Examples of the crosslinking agent include an isocyanate-based crosslinking agent and a peroxide-based crosslinking agent. Furthermore, the acrylic adhesive composition may contain an antioxidant and / or a conductive agent. Details of the adhesive layer or the acrylic adhesive composition are described in, for example, JP 2006-183022 A, JP 2015-199942 A, JP 2018-053114 A, JP 2016-190996 A, and WO 2018 / 008712 A, and the descriptions in these publications are incorporated herein by reference.

[0040] The thickness of the pressure-sensitive adhesive layer 13 is, for example, not less than 5 μm and not more than 30 μm.

[0041] B-1-5. Release liner The release liner 14 is temporarily attached to the surface of the adhesive layer 13. The release liner 14 is formed of any suitable resin film that can be used as a release liner. Specific examples of materials that are the main components of the resin film include polyethylene terephthalate (PET), polyethylene, and polypropylene. The resin film materials can be used alone or in combination. A release treatment layer may be provided on the contact surface of the release liner 14 with the adhesive layer 13. Examples of release treatment agents that form the release treatment layer include silicone-based release treatment agents, fluorine-based release treatment agents, and long-chain alkyl acrylate-based release agents. The release treatment agents can be used alone or in combination.

[0042] The thickness of the release liner 14 is, for example, 5 μm or more, preferably 20 μm or more, and, for example, 60 μm or less, preferably 45 μm or less. When a release treatment layer is applied, the thickness of the release liner includes the thickness of the release treatment layer.

[0043] C. Fixing process 1, in the fixing step, the workpiece 2 placed on the lower pressing jig 4 in the placement step is sandwiched between the lower pressing jig 4 and the upper pressing jig 3. As a result, the workpiece 2 is fixed to the upper pressing jig 3 and the lower pressing jig 4.

[0044] The upper pressing jig 3 is located on the opposite side of the lower pressing jig 4 with respect to the workpiece 2 placed on the lower pressing jig 4. The upper pressing jig 3 is movable relative to the lower pressing jig 4 in the stacking direction of the workpiece 2. The upper pressing jig 3 may adopt any appropriate configuration as long as it can sandwich the workpiece 2 between itself and the lower pressing jig 4. In one embodiment, the upper pressing jig 3 has the above-mentioned contact surface 32a and the above-mentioned opposing surface 31a.

[0045] In the illustrated example, with the workpiece 2 sandwiched and fixed between the upper pressing jig 3 and the lower pressing jig 4, the contact surface 32a contacts the entire central region E1 of the workpiece 2, and the opposing surface 31a faces the entire marginal region E3 of the workpiece 2. In addition, the region E2 to be cut of the workpiece 2 protrudes from the upper pressing jig 3 in a direction perpendicular to the stacking direction.

[0046] The contact surface 32a may be in partial contact with the central region E1 without being in contact with the entire central region E1. The facing surface 31a may be in partial contact with the margin region E3 without being in contact with the entire margin region E3. The contact area with the contact surface 32a in the central region E1 is, for example, 20% or more, preferably 50% or more, and more preferably 100%. The facing area of ​​the margin region E3 with respect to the facing surface 31a (the projected area when the facing surface is projected onto the margin region) is, for example, 20% or more, preferably 50% or more, and more preferably 100%.

[0047] The clamping pressure applied to the workpiece 2 may be any appropriate value as long as it can fix the workpiece 2. The clamping pressure per unit area of ​​the central region is, for example, 0.05 N / mm 2 More than 0.08N / mm 2More preferably, 0.1N / mm 2 For example, 0.5N / mm 2 Less than or equal to 0.3N / mm 2 The following is the result. The clamping pressure can be measured by a pressure distribution measurement system (tactile sensor). If the clamping pressure is equal to or higher than the lower limit, the workpiece can be stably fixed. If the clamping pressure is equal to or lower than the upper limit, the film position shift (lamination shift) on the workpiece can be stably suppressed. Moreover, the upper pressing jig 3 does not substantially press the cutting target area E2 and the margin area E3 while the workpiece 2 is fixed. More specifically, the clamping pressure per unit area in each of the cutting target area and the margin area is, for example, 0.01 N / mm 2 or less, preferably 0 N / mm 2 It is.

[0048] The upper pressing jig 3 in the illustrated example is integrally provided with a main body 31 having an opposing surface 31a and a protruding portion 32 having a contact surface 32a. The protruding portion 32 protrudes from the main body 31 toward the lower pressing jig 4. The contact surface 32a is the surface of the protruding portion 32 opposite to the main body 31. The contact surface 32a is typically a flat surface and extends in a direction perpendicular to the stacking direction of the workpieces 2. The contact surface 32a in the illustrated example has the same area as the above-mentioned central region E1. The opposing surface 31a is disposed so as to surround the contact surface 32a when viewed from below (the lower pressing jig side in the stacking direction of the workpieces). The opposing surface 31a is typically a flat surface. The opposing surface 31a in the illustrated example extends in a direction perpendicular to the stacking direction of the workpieces 2 and is approximately parallel to the contact surface 32a. The width of the opposing surface 31a in the illustrated example is the same as the width L2 of the above-mentioned margin region E3.

[0049] 4, the opposing surface 31a may have a tapered shape extending in a direction intersecting the stacking direction of the workpieces 2. In this case, the taper angle of the opposing surface 31a with respect to the direction perpendicular to the stacking direction is, for example, 5° to 80°. When the opposing surface 31a has a tapered shape, the maximum distance L3 between the contact surface 32a and the opposing surface 31a in the stacking direction of the workpieces 2 falls within the above-mentioned range, and the maximum distance between the margin area E3 and the opposing surface 31a in the stacking direction of the workpieces 2 with the workpieces 2 fixed falls within the above-mentioned range. Although not shown, the upper pressing jig 3 may be configured such that the portion having the contact surface 32a and the portion having the opposing surface 31a are separate bodies.

[0050] 5, the upper pressing jig 3 does not need to have the opposing surface 31a as long as it has the contact surface 32a. In this case, the upper pressing jig 3 typically has a columnar shape extending in the stacking direction of the workpieces 2, and its bottom surface is configured as the contact surface 32a.

[0051] D. Cutting process Next, as shown in Fig. 1, the end face of the fixed workpiece 2 is machined by an arbitrary and appropriate cutting tool 5. Examples of the cutting tool 5 include an end mill that can rotate about an axis parallel to the stacking direction of the workpiece, and a face mill that can rotate about an axis perpendicular to the stacking direction of the workpiece. In the illustrated example, the cutting tool 5 is an end mill. The case where the cutting tool 5 is an end mill will be described in detail below.

[0052] In the cutting process, the end mill 5 comes into contact with the end face of the workpiece 2 to cut the cutting target area E2 of the workpiece 2. The number of cutting edges of the cutting blade of the end mill 5 can be appropriately set. The number of cutting edges of the cutting blade is, for example, one or more, for example, six or less, and preferably four or less. The twist angle of the cutting blade is, for example, 0° or more, preferably 10° or more, and for example, 70° or less, preferably 60° or less. Examples of materials for the cutting blade include cemented carbide and high-speed steel, and preferably cemented carbide. The Vickers hardness (HV hardness) of the cutting blade is, for example, 800 or more, preferably 1500 or more, and for example, 2500 or less, preferably 1900 or less.

[0053] The rotation direction of the end mill 5 may be either a clockwise direction or a counterclockwise direction in a plan view. In the cutting process, the end mill 5 rotates at a constant speed. The rotation speed of the end mill 1 is, for example, 300 rpm or more, preferably 500 rpm or more, and, for example, 100,000 rpm or less, preferably 50,000 rpm or less.

[0054] The end mill 5 is movable relative to the fixed workpiece 2 while rotating as described above. The end mill may move while the workpiece 2 does not move, or the workpiece 2 may move while the end mill does not move. In one embodiment, the end mill moves around the workpiece 2 fixed as described above in one direction (preferably clockwise in a plan view) at the feed rate described below, and cuts the entire region E2 to be cut of the workpiece 2. The feed speed of the end mill in the cutting step (the relative movement speed with respect to the end face of the workpiece 2) is, for example, 10 mm / min or more, preferably 50 mm / min or more, and, for example, 5000 mm / min or less, preferably 3500 mm / min or less. In the cutting process, when the distance between the contact surface and the facing surface and / or the distance between the margin area and the facing surface is within the above range, the fluttering of the end of the film included in the workpiece can be more stably suppressed, so that the size precision of the end surface processed film can be further improved and the occurrence of cracks in the end surface processed film can be reliably suppressed.

[0055] In this manner, a plurality of edge processed films 100 with appropriately processed edge surfaces can be manufactured at once.

[0056] E. Image display device The edge-processed film manufactured by the method described in the above items A to D can be applied to an image display device. The image display device typically includes an image display cell and an edge-processed film attached to the image display cell via an adhesive layer. In one embodiment, the edge-processed film is typically attached to the image display cell by the adhesive layer after the release liner is peeled from the adhesive layer. The surface protection film may be peeled off before using the edge-processed film, or may be used in a state where it is attached to the surface of the polarizing plate. Representative examples of image display devices include liquid crystal displays and electroluminescence (EL) displays (e.g., organic EL displays and inorganic EL displays). EXAMPLES

[0057] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The measurement methods for each property are as follows. In addition, unless otherwise specified, "parts" and "%" in the examples and comparative examples are based on mass.

[0058] [Preparation Example 1] 1. Preparation of Polarizing Plates As a thermoplastic resin substrate, a long amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a Tg of about 75° C. was used, and one side of the resin substrate was subjected to a corona treatment. A PVA aqueous solution (coating solution) was prepared by adding 13 parts by mass of potassium iodide to 100 parts by mass of a PVA-based resin prepared by mixing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "GOHSEFFIMER") in a 9:1 ratio. The solution was dissolved in water. The above PVA aqueous solution was applied to the corona-treated surface of a resin substrate and dried at 60° C. to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched 2.4 times in the machine direction (longitudinal direction) in an oven at 130° C. (auxiliary air stretching treatment). Next, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by mixing 4 parts by mass of boric acid with 100 parts by mass of water) at a liquid temperature of 40° C. for 30 seconds (insolubilizing treatment). Next, the film was immersed in a dye bath (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by mass of water) at a liquid temperature of 30°C for 60 seconds while adjusting the concentration so that the single transmittance (Ts) of the finally obtained polarizer would be the desired value (dyeing treatment). Next, the piece was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by mass of potassium iodide and 5 parts by mass of boric acid with respect to 100 parts by mass of water) at a liquid temperature of 40° C. for 30 seconds (crosslinking treatment). Thereafter, the laminate was immersed in an aqueous boric acid solution (boric acid concentration: 4% by weight, potassium iodide concentration: 5% by weight) at a liquid temperature of 70°C and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to a total stretch ratio of 5.5 times (underwater stretching treatment). Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by mixing 4 parts by mass of potassium iodide with 100 parts by mass of water) at a liquid temperature of 20° C. (cleaning treatment). Thereafter, the film was dried in an oven maintained at about 90° C. while being brought into contact with a SUS heated roll whose surface temperature was maintained at about 75° C. (drying shrinkage treatment). In this manner, a polarizer having a thickness of about 5 μm was formed on the resin substrate, and a laminate having a resin substrate / polarizer structure was obtained. A TAC film (thickness 25 μm) was attached as a first protective layer to the polarizer surface (the surface opposite to the resin substrate) of the obtained laminate via an acrylic adhesive layer (thickness 5 μm). Next, the resin substrate was peeled off, and a TAC film (thickness 25 μm) was attached as a second protective layer to the exposed polarizer surface via an acrylic adhesive layer (thickness 5 μm). This resulted in a polarizing plate having a configuration of first protective layer / polarizer / second protective layer.

[0059] 2. Preparation of Laminate Film A surface protection film (thickness 55 μm) including a substrate (PET resin film) and an acrylic adhesive layer laminated on the substrate was attached to the surface of the first protective layer of the polarizing plate obtained in 1. A release liner (PET resin film provided with a release treatment layer) was attached to the surface of the second protective layer of the polarizing plate via an acrylic adhesive layer (thickness 20 μm, adhesive layer). In this manner, a film (optical laminate) having a structure of surface protective film / polarizing plate / adhesive layer / release liner was obtained. Then, the film (optical laminate) was laser cut into a desired shape and size. The film had a substantially rectangular shape when viewed from the lamination direction. The film had a long side dimension of 165 mm and a short side dimension of 72 mm. 250 sheets of such films were prepared in each example and each comparative example.

[0060] [Examples 1 to 4] As shown in Figure 1, 250 sheets of laminated film were stacked on a lower pressing jig to form a workpiece. As shown in Figure 2, the workpiece had a central region including the center of the workpiece, a cutting target region to be cut later, and a margin region located between the central region and the cutting target region when viewed from the stacking direction. The area of ​​the central region, the width of the cutting target region, and the width of the margin region are shown in Table 1.

[0061] Next, the workpiece was clamped between the lower pressing jig and the upper pressing jig to fix the workpiece. As shown in Figure 1, the upper pressing jig had a protrusion having a contact surface and a main body having an opposing surface, which were integrated together. The contact surface of the upper pressing jig was in contact with the entire central region of the workpiece, and the opposing surface of the upper pressing jig faced the entire marginal region of the workpiece. The distance between the contact surface and the opposing surface of the upper pressing jig, and the distance between the opposing surface of the upper pressing jig and the marginal region of the workpiece are shown in Table 1.

[0062] With the workpiece fixed, the upper pressing tool pressed the central region of the workpiece so that the clamping pressure on the central region was the value shown in Table 1. The upper pressing tool did not substantially press the margin region and the region to be cut.

[0063] The positional deviation (lamination deviation) of the multiple laminated films included in the fixed workpiece was evaluated according to the following criteria. The results are shown in Table 1. 〇: The amount of misalignment of stacked workpieces after clamping is less than 0.05 mm ×: The amount of misalignment of stacked workpieces after clamping is 0.05 mm or more.

[0064] Next, the area to be cut of the workpiece was cut by an end mill that was rotatable and movable relative to the lower pressing jig. In the end mill, the material of the cutting blade was cemented carbide, the HV hardness of the cutting blade was 1600, the twist angle of the cutting blade was 30°, and the number of teeth of the cutting blade was 2. The feed speed of the end mill was 3000 mm / min, and the rotation speed of the end mill was 35000 rpm. More specifically, the end mill rotated clockwise when viewed from above (the opposite side of the lower pressing jig relative to the workpiece) and moved relatively clockwise around the periphery of the laminated film while in contact with the end face of the workpiece. In this manner, a plurality of edge-processed films were produced at once.

[0065] The size precision of multiple edge-processed films manufactured at the same time was evaluated according to the following criteria. The results are shown in Table 1. 〇: All of the multiple edge-processed films are within the desired size of ±0.05 mm △: All of the multiple edge-processed films exceeded the desired size by ±0.05 mm and were within ±0.1 mm of the desired size. ×: At least one of the multiple edge-processed films exceeds the desired size by ±0.1 mm.

[0066] The occurrence of cracks in the edge-processed films was evaluated according to the following criteria, and the results are shown in Table 1. 〇: No cracks were observed in multiple edge-processed films △: The percentage of edge-processed films in which cracks occurred was less than 10%. ×: The percentage of edge-processed films in which cracks occurred was 10% or more out of multiple edge-processed films.

[0067] [Example 5] Except for the fact that the upper pressing jig is divided into a contact part having a contact surface and a peripheral end part having an opposing surface, a plurality of end surface processed films were produced in a batch in the same manner as in Example 1. Also, they were evaluated in the same manner as in Example 1.

[0068] [Example 6] As shown in Fig. 5, a plurality of end surface processed films were produced in a batch in the same manner as in Example 1, except that the upper pressing tool only had a contact surface and did not have an opposing surface. More specifically, with the workpiece fixed, the upper pressing tool was in contact with the entire central region of the workpiece, but was not in contact with the margin region and the region to be cut of the workpiece. Evaluation was also performed in the same manner as in Example 1.

[0069] [Examples 7 to 9] A plurality of edge-processed films were produced at once in the same manner as in Example 1, except that the width of the margin region was changed to the value shown in Table 1. The films were evaluated in the same manner as in Example 1.

[0070] [Example 10] A plurality of edge-processed films were produced in a batch in the same manner as in Example 1, except that the width of the margin area, the width of the area to be cut, and the distance between the opposing surface and the margin area were changed to the values ​​shown in Table 1. Also, they were evaluated in the same manner as in Example 1.

[0071] [Comparative Example 1] With the workpiece fixed, the upper pressing tool pressed the entire workpiece (the central region, the margin region, and the region to be cut) uniformly, and other than that, multiple end surface processed films were produced in a batch in the same manner as in Example 1. Also, they were evaluated in the same manner as in Example 1.

[0072] [Comparative Example 2] A plurality of end surface processed films were produced in a batch in the same manner as in Example 1, except that the distance between the contact surface and the opposing surface in the upper pressing jig was changed to the value shown in Table 1. More specifically, while the workpiece was fixed, the upper pressing jig pressed the central region of the workpiece so that the clamp pressure against the central region was the value shown in Table 1, and also substantially pressed the margin region and the region to be cut. Also, evaluation was performed in the same manner as in Example 1.

[0073] [Table 1]

[0074] [evaluation] As is clear from Table 1, if the upper pressing tool presses the central region of the workpiece while the workpiece is fixed, and does not substantially press the margin region and the region to be cut, it is possible to suppress the lamination shift of the film included in the fixed workpiece. It is also possible to improve the size accuracy of the edge-processed film and suppress the occurrence of cracks in the edge-processed film when the distance between the opposing surface of the upper pressing tool and the contact surface and / or the distance between the opposing surface of the upper pressing tool and the margin region of the workpiece is within a specific range. [Industrial Applicability]

[0075] The edge-processed film manufacturing method of the present invention can manufacture an edge-processed film for use in various industrial products. The edge-processed film is suitably used in display devices such as liquid crystal display devices, organic EL display devices, and inorganic EL display devices. [Explanation of symbols]

[0076] 1. Film 2 Work 3 Upper pressing tool 31 Main unit 31a Opposite side 32 Protrusion 32a Contact surface 4 Lower pressing jig 5 Cutting tool E1 Central region E2 Cutting target region E3 Margin region

Claims

1. A placement step of placing a workpiece having a plurality of films laminated thereon on a lower pressing jig; a fixing step of clamping the workpiece between the lower pressing tool and the upper pressing tool to fix the workpiece; A cutting process for cutting the end surface of the fixed workpiece, The workpiece arranged in the arrangement step includes, as viewed from a stacking direction, a central region including a center of the workpiece; a cutting target region to be cut in the cutting step; and a margin region located between the central region and the cutting target region; A method for manufacturing an edge processed film, wherein in the fixing step, the upper pressing jig presses the central region and does not substantially press the margin region and the region to be cut.

2. The width of the cutting target area is 0.1 mm or more and 1.5 mm or less, The method for producing an edge processed film according to claim 1 , wherein the width of the region to be cut and the width of the margin region satisfy the following formula (1): 0.005≦(L1+L2) / a≦0.15...(1) (In formula (1), a represents the number of layers of the film in the workpiece, L1 represents the width [mm] of the area to be cut, and L2 represents the width [mm] of the margin area.)

3. The manufacturing method of claim 1 or 2, wherein the upper pressing jig has: a contact surface that contacts the central region in the fixing process; and an opposing surface that faces the margin region in the fixing process.

4. The method for manufacturing an edge processed film according to claim 3 , wherein when the workpiece is fixed, a distance between the margin area and the opposing surface in a stacking direction of the workpiece is 0 mm or more and 1.0 mm or less.

5. 4. The method for producing an edge processed film according to claim 3, wherein the distance between the contact surface and the opposing surface in the stacking direction of the workpiece satisfies the following formula (2): 0.005≦L3 / a≦0.03 (2) (In formula (2), a represents the number of layers of the film in the workpiece, and L3 represents the distance [mm] between the contact surface and the opposing surface in the layering direction of the workpiece.)

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