Method for producing end-face-processed film

Abstract

Provided is a method for manufacturing an end-surface-processed film, which is capable of suppressing positional displacement of a plurality of films included in a workpiece and capable of cutting the end surfaces of the plurality of films at the same time with good precision. A method for manufacturing an end face processing film according to an embodiment of the present invention comprises: a step for disposing a workpiece in which a plurality of films are laminated on a lower pressing jig; a step for clamping and fixing the workpiece by means of the lower pressing jig and the upper pressing jig; and a step for cutting the end surface of the fixed workpiece. When viewed from the stacking direction, the workpiece is provided with a central region including the center of the workpiece, a region to be cut that is cut in the cutting step, and a blank region located between the central region and the region to be cut. In the step of fixing the workpiece, the pressing tool presses the central region and does not substantially press the blank region and the region to be cut.

Description

Technical Field The present invention relates to a method for manufacturing an end surface processing film. Background Art Resin films have been widely used in various industrial products. It is known that after such a resin film is cut into a shape corresponding to the application, its cut surface is finely processed by cutting. For example, a method for manufacturing an end-face processed film has been proposed, in which a stacked body having multiple films is pressed from both sides of the stacking direction of the stacked body by a first contact member and a second contact member to fix the stacked body and then process the end face of the stacked body (for example, refer to patent document 1). However, in the method for manufacturing an end-face processed film described in patent document 1, when the stacked body is pressed from both sides of the stacking direction by the first contact member and the second contact member, the film contained in the stacked body is sometimes offset in a direction orthogonal to the stacking direction of the stacked body. In this case, there is a hidden danger that the accuracy of the end face processing of each of the multiple films becomes insufficient. Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2021-11008 Summary of the invention Problems to be solved by the invention The present invention is made to solve the above-mentioned conventional problems, and its main object is to provide a method for manufacturing an end surface processed film which can suppress positional deviation of a plurality of films included in a workpiece and can cut the end surfaces of a plurality of films at once with good accuracy. Solutions to the problem

[0001] The manufacturing method of the end surface processing film of the embodiment of the present invention includes: a configuration step of configuring a workpiece formed by stacking a plurality of films on a lower pressing jig; a fixing step of clamping the workpiece by the lower pressing jig and the upper pressing jig and fixing the workpiece; and a cutting step of cutting the end surface of the fixed workpiece. When viewed from the stacking direction, the workpiece configured in the configuration step includes: a central area including the center of the workpiece, a cutting target area to be cut in the cutting step, and a blank area between the central area and the cutting target area. In the fixing step, the upper pressing jig presses the central area and substantially does not press the blank area and the cutting target area.

[0002] In the method for manufacturing an end surface processing film described in [1], the width of the cutting target area may be greater than or equal to 0.1 mm and less than or equal to 1.5 mm, and the width of the cutting target area and the width of the blank area may satisfy the following formula (1): 0.005≤(L1+L2) / a≤0.15···(1) (In the formula (1), a represents the number of films stacked in the workpiece, L1 represents the width of the cutting target area [mm], and L2 represents the width of the blank area [mm]).

[0003] In the method for manufacturing an end surface processing film described in [1] or [2] above, the upper pressing jig may have: a contact surface that contacts the central area in the fixing step; and an opposing surface that faces the blank area in the fixing step.

[0004] In the method for producing an end surface processing film described in [3] above, in a state where the work is fixed, the interval between the blank area and the opposing surface in the stacking direction of the work may be greater than or equal to 0 mm and less than or equal to 1.0 mm.

[0005] In the method for manufacturing an end surface processing film described in [3] or [4] above, the interval 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 films stacked in the workpiece, and L3 represents the distance [mm] between the contact surface and the opposing surface in the stacking direction of the workpiece). Effects of the Invention According to the embodiment of the present invention, positional deviation of a plurality of films included in a workpiece can be suppressed, and the end surfaces of the plurality of films can be cut collectively with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is a schematic diagram for explaining a method for producing an end surface processing film according to one embodiment of the present invention. Figure 2 yes Figure 1 Top view of the workpiece. Figure 3 yes Figure 2 A schematic cross-sectional view of a film provided on a workpiece. Figure 4 This is a schematic diagram for explaining a method for producing an end surface processing film according to another embodiment of the present invention. Figure 5 This is a schematic diagram for explaining a method for producing an end surface processing film according to still another embodiment of the present invention. Explanation of symbols 1. Membrane 2 Workpiece 3 Upper press fixture 31 Subject 31a Opposite side 32 Protrusion 32a Contact surface 4 Press down the clamp 5 Cutting tools E1 Central Area E2 Cutting target area E3 Blank Area DETAILED DESCRIPTION Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments. In addition, in the accompanying drawings, in order to make the description clearer, the width, thickness, shape, etc. of each part are sometimes schematically shown compared with the embodiments, but it is only an example and does not limit the interpretation of the present invention. A. Overview of the method for producing the end surface processing film Figure 1 It is a schematic diagram for explaining a method for manufacturing an end surface processing film according to one embodiment of the present invention; Figure 2 yes Figure 1 A top view of the workpiece; Figure 3 for Figure 2 A schematic cross-sectional view of a film provided on a workpiece. The manufacturing method of the end surface processing film of the embodiment of the present invention includes: a configuration step, a fixing step, and a cutting step. In the configuration step, a workpiece 2 formed by stacking a plurality of films 1 is configured on a lower pressing fixture 4. When viewed from the stacking direction, the configured workpiece 2 has: a central area E1 including the center of the workpiece 2, a cutting target area E2 to be cut in the cutting step, and a blank area E3 located between the central area E1 and the cutting target area E2. In the fixing step, the workpiece 2 is clamped by the lower pressing fixture 4 and the upper pressing fixture 3 to fix the workpiece 2. In the fixing step, the upper pressing fixture 3 presses the central area E1 and does not substantially press the blank area E3 and the cutting target area E2. In the cutting step, the end surface of the fixed workpiece 2 is cut. The inventors of the present invention have found that if a plurality of films are stacked to form a workpiece, the thickness of the workpiece will become uneven due to the cutting when preparing each film, thereby completing the present invention. In more detail, the film is typically prepared by cutting out the desired shape and size from the original film by any appropriate cutting method. As a cutting method, for example, a laser can be cited. If such a film is stacked to form a workpiece, there is a situation where the end of the workpiece is thicker than the center of the workpiece. In this case, in the fixing process, when the upper pressing fixture presses the area containing the end of the workpiece, there is a hidden danger that the film contained in the workpiece is offset in a direction orthogonal to the stacking direction, and the end faces of the plurality of films cannot be fully cut. In contrast, in the embodiment of the present invention, in the fixing process, the upper pressing fixture presses the central area of ​​the workpiece and does not substantially press the blank area and the cutting target area of ​​the workpiece. Therefore, even if the thickness (the dimension in the stacking direction) of the blank area of ​​the workpiece is greater than the thickness (the dimension in the stacking direction) of the central area of ​​the workpiece, the positional deviation of the plurality of films included in the workpiece can be suppressed, and the end faces of the plurality of films can be cut at once with good accuracy. Therefore, a plurality of end face processed films with excellent dimensional accuracy can be manufactured at once. The cutting target area E2 of the workpiece 2 is located at the peripheral portion of the workpiece 2. The cutting target area E2 includes at least an area (cutting area) that is actually cut in the cutting process. In addition to the cutting area, the cutting target area E2 may also include a safety area for suppressing erroneous cutting of the pressing fixture caused 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 workpiece 2 is clamped by the upper pressing clamp 3 and the lower pressing clamp 4 and projected in the stacking direction, the cutting object area E2 of the workpiece 2 is located outside the projection surface of each of the upper pressing clamp 3 and the lower pressing clamp 4, including a safety area. The width L1 of the cutting target area E2 of the workpiece 2 is the size 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 blank area. The width L1 of the cutting target area E2 is, for example, 0.1 mm or more, preferably 0.5 mm or more, for example, 3.0 mm or less, preferably 1.5 mm or less, and more preferably 1.1 mm or less. The width L2 of the blank area E3 of the workpiece 2 is the size of the blank area in a direction perpendicular to the end surface of the workpiece, and is the distance from the cutting target area to the central area. The width L2 of the blank area E3 satisfies the following formula (I), preferably 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 stacked in workpiece 2, and L2 represents the width [mm] of the blank area.) If the widths of the cutting target region and the blank region which are not substantially pressed by the upper pressing jig are within the above ranges, positional deviation of the film in the fixing step can be stably suppressed. In one embodiment, in the workpiece 2 , the width L1 of the cutting target region E2 and the width L2 of the blank region E3 satisfy the following formula (1). 0.005≤(L1+L2) / a≤0.15···(1) (In the formula (1), a represents the number of films stacked in the workpiece, L1 represents the width of the cutting target area [mm], and L2 represents the width of the blank area [mm].) If (L1+L2) / a satisfies the above-mentioned formula (1), positional deviation of a plurality of films included in the workpiece can be suppressed more stably. (L1+L2) / a is preferably 0.008 or more. The number of stacked films 1 in the workpiece 2 is, for example, 50 or more, preferably 100 or more, more preferably 150 or more, and further preferably 200 or more, and is, for example, 1000 or less, preferably 600 or less, more preferably 400 or less, and further preferably 300 or less. In one embodiment, the upper pressing jig 3 has a contact surface 32a that contacts the central area E1 during the fixing process and an opposing surface 31a that faces the blank area E3 during the fixing process. The opposing surface 31a is located on the opposite side of the workpiece 2 relative to the contact surface 32a in the stacking direction of the workpiece 2. When the upper pressing jig 3 and the lower pressing jig 4 are projected in the stacking direction with the workpiece 2 sandwiched therebetween, the blank area E3 of the workpiece 2 is typically an area overlapping the projection surface of the opposing surface 31 a . In one embodiment, the interval L3 between the contact surface 32a and the opposing surface 31a in the stacking direction of the workpiece 2 satisfies the following formula (2). 0.005≤L3 / a≤0.03···(2) (In formula (2), a represents the number of films stacked in the workpiece, and L3 represents the distance [mm] between the contact surface and the opposing surface in the stacking 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. If L3 / a is greater than the above lower limit, the pressing of the blank area by the upper pressing fixture can be stably avoided in the fixing process. If L3 / a is less than the above upper limit, the deviation of the end of the film included in the workpiece can be suppressed in the cutting process. Thus, the dimensional accuracy of the manufactured end surface processing film can be improved, and the generation of cracks in the end surface processing film can be suppressed. The interval L3 between the contact surface 32a and the opposing surface 31a in the stacking direction of the workpiece 2 is, for example, greater than 1.0 mm, preferably greater than 2.0 mm, for example, less than 5.0 mm, preferably less than 4.0 mm, and more preferably less than 3.5 mm. If the interval between the contact surface and the opposite surface is greater than the above lower limit, the pressing of the blank area by the upper pressing fixture can be stably avoided in the fixing process. If the interval between the contact surface and the opposite surface is less than the above upper limit, the deviation of the end of the film included in the workpiece can be further suppressed in the cutting process. In this way, the dimensional accuracy of the end surface processing film to be manufactured can be further improved, and the generation of cracks in the end surface processing film can be further suppressed. When the workpiece 2 is fixed, as long as the opposing surface 31 a faces the blank area E3 in the stacking direction of the workpiece 2 , the opposing surface 31 a may contact the blank area E3 within a range where substantially no pressure is generated, or may be located at a distance from the blank area E3 . When the workpiece 2 is fixed, the interval between the blank area E3 in the stacking direction of the workpiece 2 and the relative surface 31a is, for example, greater than 0 mm, preferably greater than 0.1 mm, for example, less than 2.0 mm, preferably less than 1.5 mm, more preferably less than 1.0 mm, and further preferably less than 0.5 mm. If the interval between the blank area and the opposite surface is greater than the above lower limit, the pressing of the blank area by the upper pressing fixture can be more stably avoided in the fixing process. If the interval between the blank area and the opposite surface is less than the above upper limit, the deviation of the end of the film included in the workpiece can be further suppressed in the cutting process. Therefore, the dimensional accuracy of the end surface processing film can be further improved, and the generation of cracks in the end surface processing film can be stably suppressed. Hereinafter, each step of the method for producing the end surface processing film will be described in detail. B. Configuration process like Figure 1 As shown, in one embodiment, in the arrangement step, a plurality of films 1 are stacked on the lower pressing jig 4. More specifically, the plurality of films 1 are stacked on the lower pressing jig 4 so that imaginary lines passing through the center of the film 1 and parallel to the thickness direction coincide with each other. Thus, a workpiece 2 having the above-mentioned central area E1, cutting target area E2 and blank area E3 is formed on the lower pressing fixture 4. The lower pressing fixture 4 can adopt any appropriate shape. The lower pressing fixture 4 typically has a flat surface, and the workpiece 2 is arranged on the flat surface. When the workpiece 2 is arranged on the lower pressing fixture 4, the central area E1 and the cutting target area E2 of the workpiece 2 are in contact with the lower pressing fixture 4, and the cutting target area E2 of the workpiece 2 protrudes from the lower pressing fixture 4 in a direction orthogonal to the stacking direction. The thickness of the central region E1 of the workpiece 2 may be any appropriate size depending on the number of layers of the above-mentioned film 1. The thickness of the central region E1 is, for example, 10 mm or more, preferably 30 mm or more, and for example, 200 mm or less, preferably 150 mm or less. The maximum thickness of the blank area E3 is typically greater than or equal to the thickness of the central area E1. When the thickness of the central area E1 is 1, the thickness of the blank area E3 is, for example, 1.00 or greater, preferably greater than 1.00, more preferably 1.02 or greater, and for example, 1.15 or less. The cutting target area E2 can have any appropriate thickness. The shape of the workpiece 2 observed from the stacking direction is the same as the shape of the film 1 described later. Figure 2 The workpiece 2 shown has a rectangular shape. 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, relative to the total area of ​​the central region E1, the cutting target region E2, and the blank region E3. The area of ​​the central area E1 is specifically 2000mm 2 Above, preferably 6000mm 2 Above, for example, 500000mm 2 Below, preferably 300000mm 2 the following. The cutting target region E2 only needs to have the above-mentioned width L1, and its area can be set arbitrarily and appropriately. The blank area E3 only needs to have the above-mentioned width L2, and its area can be set arbitrarily and appropriately. B-1. Details of membrane Next, the film 1 used for the workpiece 2 will be described in detail. Film 1 can adopt any appropriate shape. As the shape of film, polygonal shape can be representatively enumerated, quadrilateral shape can be preferably enumerated, and rectangular shape can be more preferably enumerated. When film is rectangular shape, the size of its long side is representatively more than 50mm and less than 1000mm, and the size of its short side is representatively more than 30mm and less than 550mm. The film 1 may have any appropriate structure. In one embodiment, the film 1 is a laminated film in which a plurality of films (layers) are laminated. like Figure 3 As shown, in one embodiment, the film 1 is an optical laminate, which comprises: a polarizer 11 including a polarizer 15; a surface protection film 12 adhered to the polarizer 11; an adhesive layer 13 laminated on the polarizer 11 on the opposite side of the surface protection film 12; and a release liner 14 adhered 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 for example, 800 μm or less, preferably 500 μm or less. 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. Specific examples of the polarizer composed of a single-layer resin film include: a polarizer obtained by dyeing and stretching a hydrophilic polymer film such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, and a partially saponified film of an ethylene-vinyl acetate copolymer, using a dichroic substance such as iodine or a dichroic dye; and a polyene-based oriented film such as a dehydrated product of PVA and a dehydrochlorinated product of polyvinyl chloride. A polarizer obtained by dyeing a PVA film with iodine and uniaxially stretching the film is preferably used because of its excellent optical properties. The dyeing using iodine can be performed by, for example, immersing the PVA film in an iodine aqueous solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching can be performed after the dyeing treatment or while dyeing. In addition, dyeing can be performed after the stretching. The PVA film can be subjected to swelling treatment, cross-linking treatment, cleaning treatment, drying treatment, etc. as required. For example, by immersing the PVA film in water for washing before dyeing, not only can the dirt and anti-blocking agent on the surface of the PVA film be cleaned, but also the PVA film can be swollen to prevent uneven dyeing. As a specific example of a polarizer obtained using a laminate, there can be cited a laminate using a resin substrate and a PVA-type resin layer (PVA-type resin film) laminated on the resin substrate, or a laminate using a resin substrate and a PVA-type resin layer formed by coating on the resin substrate. The polarizer obtained using a laminate of a resin substrate and a PVA-type resin layer formed by coating on the resin substrate can be made by the following method: for example, a PVA-type resin solution is applied to a resin substrate, and the PVA-type resin layer is formed on the resin substrate by drying, thereby obtaining a laminate of the resin substrate and the PVA-type resin layer; the laminate is stretched and dyed to make the PVA-type resin layer into a polarizer. In one embodiment of the present invention, a polyvinyl alcohol-type resin layer containing a halide and a polyvinyl alcohol-type resin is preferably formed on one side of the resin substrate. Stretching typically includes immersing the laminate in a boric acid aqueous solution for stretching. In addition, stretching may further include stretching the laminate in a gas atmosphere at a high temperature (for example, above 95°C) before stretching in a boric acid aqueous solution as needed. In addition, in one embodiment of the present invention, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate shrinks by more than 2% in the width direction by heating while being conveyed in the length direction. Representatively, the manufacturing method of this embodiment includes sequentially subjecting the laminate to an auxiliary stretching treatment in a gas atmosphere, a dyeing treatment, a stretching treatment in an aqueous solution, and a drying shrinkage treatment. By introducing auxiliary stretching, the crystallinity of the PVA can be improved even when the PVA is coated on the thermoplastic resin, and high optical properties can be achieved. In addition, by simultaneously improving the orientation of the PVA in advance, it is possible to prevent problems such as a decrease in orientation and dissolution of the PVA when immersed in water in the subsequent dyeing process and the stretching process, and high optical properties can be achieved. In addition, when the PVA-type resin layer is immersed in a liquid, the orientation disorder of the polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to the case where the PVA-type resin layer does not contain a halide. Thus, the optical properties of the polarizer obtained by the treatment process of immersing the laminate in a liquid such as a dyeing treatment and a stretching treatment in an aqueous solution can be improved. Furthermore, the laminate is shrunk in the width direction by drying and shrinking treatment, thereby improving the optical properties. The obtained laminate of resin substrate / polarizer can be used directly (that is, the resin substrate can be made into a protective layer of polarizer), or the resin substrate can be peeled off from the laminate of resin substrate / polarizer, and any appropriate protective layer corresponding to the purpose can be stacked on the peeled surface for use. The details of the manufacturing method of such a polarizer are described in, for example, Japanese Patent Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire records of these publications are cited as references in this specification. 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 such a range, curling during heating can be well suppressed and good appearance durability during heating can be obtained. The polarizer preferably exhibits absorption dichroism at any wavelength within the wavelength range 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 polarization degree of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more. B-1-2. Protective layer The polarizing plate 1 may further 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 example shown in the figure, the protective layer 16 is provided on both surfaces of the polarizer 15. The protective layer 16 is typically bonded to the polarizer 15 via any appropriate adhesive layer (not shown). The protective layer can be formed by any appropriate film that can be used as a protective layer of a polarizer. Specific examples of the material that is the main component of the film include: cycloolefins (COP) such as polynorbornenes, polyesters such as polyethylene terephthalate (PET), cellulose resins such as triacetyl cellulose (TAC), polycarbonates (PC), (meth) acrylic acid, polyvinyl alcohol, polyamide, polyimide, polyether sulfone, polysulfone, polystyrene, polyolefin, acetate and other transparent resins. In addition, thermosetting resins or ultraviolet curing resins such as (meth) acrylic acid, carbamate, (meth) acrylic acid carbamate, epoxy, silicone, etc. can also be mentioned. It should be noted that "(meth) acrylic resin" refers to acrylic resin and / or methacrylic resin. In addition, glassy polymers such as siloxane polymers can also be mentioned. In addition, the polymer film of recording in Japanese Patent Publication No. 2001-343529 (WO01 / 37007) can also be used. As the material of this film, 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 and nitrile group in the side chain can be used, and for example: a resin composition having an alternating copolymer formed by isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer can be cited. This polymer film can be, for example, an extrusion molding of the above-mentioned resin composition. The material of the resin film can be used alone or in combination. 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. B-1-3. Surface protection film In the example shown in the figure, the surface protection film 12 is attached to the protective layer 16 of the polarizer 11. The surface protection film 12 is typically provided with a substrate and an adhesive layer. As the material of the substrate, for example, the same resin as the resin constituting the protective layer 16 can be cited. The adhesive layer adheres the substrate of the surface protection film 12 to the protective layer 16. The adhesive layer can be composed of any appropriate adhesive. The adhesive layer of the surface protection film 12 can be constructed in the same manner as the adhesive layer 13 described later. The total thickness of the surface protection film 12 is, for example, 20 μm or more, preferably 40 μm or more, and for example, 90 μm or less, preferably 70 μm or less. B-1-4. Adhesive layer The adhesive layer 13 is located on the side of the polarizing plate 11 opposite to the surface protection film 12. In the example shown in the figure, the adhesive layer 13 is laminated on the surface of the protection layer 16. The storage modulus of the adhesive layer 13 at 25°C is preferably 1.0×10 4 Pa~1.0×10 6 Pa, more preferably 1.0×10 4 Pa~1.0×10 5 Pa. When the storage elastic modulus of the adhesive layer is within such a range, it is possible to stably suppress the occurrence of defects in the adhesive layer during the cutting step. The adhesive layer 13 is formed by an adhesive. As an adhesive, any appropriate composition can be adopted. As a specific example of the adhesive constituting the adhesive layer, acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, epoxy adhesives, and polyether adhesives can be cited. By adjusting the type, quantity, combination and proportion of the monomers of the base resin forming the adhesive, as well as the amount of the crosslinking agent, the reaction temperature, the reaction time, etc., it is possible to prepare an adhesive with the desired characteristics corresponding to the purpose. The base resin of the adhesive can be used alone or in combination of two or more. From the viewpoints of transparency, processability and durability, it is preferably an acrylic adhesive (acrylic adhesive composition). The acrylic adhesive composition representatively includes a (meth) acrylic polymer as a main component. In the solid component of the adhesive composition, the (meth) acrylic polymer can be included in the adhesive composition in a ratio of, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more. The (meth) acrylic polymer contains an alkyl (meth) acrylate as a monomer unit as a main component. It should be noted that (meth)acrylate refers to acrylate and / or methacrylate. In the monomer components forming the (meth)acrylic polymer, it is preferred that the (meth)acrylic acid alkyl ester is contained in a ratio of 80% by mass or more, more preferably 90% by mass or more. As the alkyl group of the (meth)acrylic acid alkyl ester, for example, a linear or branched alkyl group having 1 to 18 carbon atoms can be cited. The average number of carbon atoms of the alkyl group is preferably 3 to 9, more preferably 3 to 6. The preferred (meth)acrylic acid alkyl ester is butyl acrylate. As monomers (comonomers) constituting the (meth)acrylic polymer, in addition to the (meth)acrylic acid alkyl ester, carboxyl-containing monomers, hydroxyl-containing monomers, amide-containing monomers, aromatic ring-containing (meth)acrylates, heterocyclic vinyl-containing monomers, etc. can also be cited. As representative examples of comonomers, acrylic acid, 4-hydroxybutyl acrylate, phenoxyethyl acrylate, and N-vinyl-2-pyrrolidone can be cited. The acrylic adhesive composition can preferably contain a silane coupling agent and / or a crosslinking agent. As the silane coupling agent, for example, epoxy-containing silane coupling agents can be mentioned. As the cross-linking agent, for example, isocyanate cross-linking agents and peroxide cross-linking agents can be mentioned. In addition, the acrylic adhesive composition may contain an antioxidant and / or a conductive agent. The details of the adhesive layer or the acrylic adhesive composition are, for example, recorded in Japanese Patent Publication No. 2006-183022, Japanese Patent Publication No. 2015-199942, Japanese Patent Publication No. 2018-053114, Japanese Patent Publication No. 2016-190996, and International Publication No. 2018 / 008712, and the records of these publications are cited as references in this specification. The thickness of the adhesive layer 13 is, for example, 5 μm or more and 30 μm or less. 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 appropriate resin film that can be used as a release liner. Specific examples of the material that becomes the main component of the resin film include polyethylene terephthalate (PET), polyethylene, and polypropylene. The materials of the resin film can be used alone or in combination. A release treatment layer can be provided on the contact surface of the release liner 14 with the adhesive layer 13. As the release treatment agent that forms the release treatment layer, for example, a silicone release treatment agent, a fluorine release treatment agent, and a long-chain alkyl acrylate release agent can be mentioned. The release treatment agent can be used alone or in combination. The thickness of the release liner 14 is, for example, 5 μm or more, preferably 20 μm or more, for example, 60 μm or less, preferably 45 μm or less. When a release treatment layer is provided, the thickness of the release liner includes the thickness of the release treatment layer. C.Fixed process like Figure 1 As shown, in the fixing process, the workpiece 2 arranged on the lower pressing jig 4 in the arrangement process is sandwiched between the lower pressing jig 4 and the upper pressing jig 3. Thus, the workpiece 2 is fixed to the upper pressing jig 3 and the lower pressing jig 4. The upper pressing fixture 3 is located on the opposite side of the workpiece 2 arranged on the lower pressing fixture 4. The upper pressing fixture 3 can move relative to the lower pressing fixture 4 in the stacking direction of the workpiece 2. The upper pressing fixture 3 can adopt any appropriate structure as long as it can clamp the workpiece 2 between it and the lower pressing fixture 4. In one embodiment, the upper pressing fixture 3 has the above-mentioned contact surface 32a and the above-mentioned opposite surface 31a. In the example shown in the figure, when the workpiece 2 is clamped between the upper pressing jig 3 and the lower pressing jig 4 and fixed, the contact surface 32a is in contact with the entire central area E1 of the workpiece 2, and the opposing surface 31a is facing the entire blank area E3 of the workpiece 2. In addition, the cutting target area E2 of the workpiece 2 protrudes from the upper pressing jig 3 in a direction orthogonal to the stacking direction. It should be noted that the contact surface 32a may not be in contact with the entire central area E1 but may be in contact with the central area E1 partially. In addition, the opposing surface 31a may not be opposed to the entire blank area E3 but may be opposed to the blank area E3 partially. The contact area with the contact surface 32 a in the central region E1 is, for example, 20 area % or more, preferably 50 area % or more, and more preferably 100 area % or more. The opposing area of ​​the blank area E3 with respect to the opposing surface 31 a (projected area when the opposing surface is projected onto the blank area) is, for example, 20 area % or more, preferably 50 area % or more, and more preferably 100 area % or more. The clamping pressure on the workpiece 2 may be any appropriate value as long as the workpiece 2 can be fixed. The clamping pressure per unit area of ​​the central region is, for example, 0.05 N / mm 2 Above, preferably 0.08N / mm 2 More preferably 0.1 N / mm 2 Above, for example, 0.5N / mm 2 Below, preferably 0.3N / mm 2 the following. It should be noted that the clamping pressure can be measured by a pressure distribution measurement system (tactile sensor). If the clamping pressure is above the lower limit, the workpiece can be stably fixed. If the clamping pressure is below the upper limit, the positional deviation (stack deviation) of the film in the workpiece can be stably suppressed. In addition, the upper pressing fixture 3 does not substantially press the cutting target area E2 and the blank area E3 when the workpiece 2 is fixed. More specifically, the clamping pressure per unit area of ​​the cutting target area and the blank area is, for example, 0.01 N / mm 2 Below, preferably 0N / mm 2 . The upper pressing fixture 3 of the illustrated example integrally comprises a main body 31 having a relative surface 31a and a protrusion 32 having a contact surface 32a. The protrusion 32 protrudes from the main body 31 to the lower pressing fixture 4. The contact surface 32a is the surface of the protrusion 32 on the opposite side of the main body 31. The contact surface 32a is typically a flat surface extending in a direction orthogonal to the stacking direction of the workpiece 2. The contact surface 32a of the illustrated example has the same area as the central area E1 described above. When viewed from below (on the lower pressing fixture side in the stacking direction of the workpiece), the relative surface 31a is configured to surround the contact surface 32a. The relative surface 31a is typically a flat surface. The relative surface 31a of the illustrated example extends in a direction orthogonal to the stacking direction of the workpiece 2 and is substantially parallel to the contact surface 32a. The width of the relative surface 31a of the illustrated example is the same as the width L2 of the blank area E3 described above. In addition, if Figure 4 As shown, the opposing surface 31a may have a tapered shape extending in a direction intersecting the stacking direction of the workpiece 2. In this case, the taper angle of the opposing surface 31a relative to the direction orthogonal to the stacking direction is, for example, 5° or more and 80° or less. In the case where the opposing surface 31a has a tapered shape, the maximum interval L3 between the contact surface 32a and the opposing surface 31a in the stacking direction of the workpiece 2 is within the above-mentioned range, and in a state where the workpiece 2 is fixed, the maximum interval between the blank area E3 in the stacking direction of the workpiece 2 and the opposing surface 31a is within the above-mentioned range. Although not shown in the drawings, the portion having the contact surface 32 a and the portion having the facing surface 31 a in the upper pressing jig 3 may be independently configured. In addition, if Figure 5 As shown, the upper pressing jig 3 only needs to have the contact surface 32a, and may not have the facing surface 31a. In this case, the upper pressing jig 3 typically has a columnar shape extending along the stacking direction of the workpiece 2, and its bottom surface constitutes the contact surface 32a. D. Cutting process Next, if Figure 1 As shown, the end face of the fixed workpiece 2 is cut by any and appropriate cutting tool 5. As the cutting tool 5, for example, there can be cited: an end mill that can rotate around an axis parallel to the stacking direction of the workpiece, and a front milling cutter that can rotate around an axis orthogonal to the stacking direction of the workpiece. In the example shown in the figure, the cutting tool 5 is an end mill. The case where the cutting tool 5 is an end mill is described in detail below. The end mill 5 contacts the end face of the workpiece 2 during the cutting process and cuts the cutting target area E2 of the workpiece 2. The number of cutting edges of the end mill 5 can be appropriately set. The number of cutting edges is, for example, more than 1, for example, less than 6, and preferably less than 4. The torsion angle of the cutting edge is, for example, more than 0°, preferably more than 10°, for example, less than 70°, and preferably less than 60°. Examples of the material of the cutting edge include superhard alloys and high-speed steels, and superhard alloys are preferred. The Vickers hardness (HV hardness) of the cutting edge is, for example, more than 800, preferably more than 1500, for example, less than 2500, and preferably less than 1900. The rotation direction of the end mill 5 can be clockwise or counterclockwise when viewed from above. In the cutting process, the end mill 5 rotates at a certain speed. The rotation speed of the end mill 1 is, for example, 300 rpm or more, preferably 500 rpm or more, for example, 100,000 rpm or less, preferably 50,000 rpm or less. The end mill 5 can rotate as described above while moving relative to the fixed workpiece 2. The end mill can move while the workpiece 2 is not moving, or the workpiece 2 can move while the end mill is not moving. 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 following feed speed to cut the entire cutting target area E2 of the workpiece 2. The feed speed (relative movement speed with respect to the end surface of the workpiece 2 ) of the end mill in the cutting step is, for example, 10 mm / min or more, preferably 50 mm / min or more, for example, 5000 mm / min or less, preferably 3500 mm / min or less. In the cutting process, if the interval between the contact surface and the opposite surface, and / or the interval between the blank area and the opposite surface is within the above range, the deviation of the end of the film included in the workpiece can be more stably suppressed. Therefore, the dimensional accuracy of the end surface processed film can be further improved, and the generation of cracks in the end surface processed film can be effectively suppressed. Through the above operation, a plurality of end surface processed films 100 whose end surfaces have been appropriately processed can be manufactured at once. E. Image display device The end-face processing film manufactured by the method described in items A to D above can be applied to an image display device. The image display device typically includes: an image display unit, and an end-face processing film adhered to the image display unit via an adhesive layer. In one embodiment, the end-face processing film is typically adhered to the image display unit through the adhesive layer after the release liner is peeled off from the adhesive layer. In addition, the surface protection film can be peeled off before using the end-face processing film, or it can be used in a state of being adhered to the surface of the polarizer. As representative examples of image display devices, liquid crystal display devices and field-induced luminescence (EL) display devices (for example, organic EL display devices, inorganic EL display devices) can be cited. Example The present invention is described in detail below with reference to the examples, but the present invention is not limited to these examples. The measuring methods of each characteristic are as follows. It should be noted that, unless otherwise specified, the "parts" and "%" in the examples and comparative examples are based on mass. [Preparation Example 1] 1. Preparation of polarizer As the thermoplastic resin substrate, a long amorphous polyethylene terephthalate copolymer film (thickness: 100 μm) having a Tg of about 75° C. was used, and one surface of the resin substrate was subjected to a corona treatment. To 100 parts by mass of a PVA-based resin obtained by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER") in a ratio of 9:1, 13 parts by mass of potassium iodide was added and the resulting mixture was dissolved in water to prepare a PVA aqueous solution (coating solution). The PVA aqueous solution was applied to the corona-treated surface of the resin substrate and dried at 60° C. to form a PVA-based resin layer having a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched to 2.4 times in the longitudinal direction (length direction) in an oven at 130° C. (auxiliary stretching treatment in an atmosphere). Next, the laminate was immersed in an insolubilization bath (boric acid aqueous solution obtained by blending 4 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 (insolubilization treatment). Next, the film was immersed in a dyeing bath (an iodine aqueous solution obtained by mixing iodine and potassium iodide at a weight ratio of 1:7 per 100 parts by mass of water) at a liquid temperature of 30° C. for 60 seconds while adjusting the concentration so that the single body transmittance (Ts) of the finally obtained polarizer would reach a desired value (dyeing treatment). Next, the sample was immersed in a crosslinking bath (boric acid aqueous solution containing 3 parts by mass of potassium iodide and 5 parts by mass of boric acid per 100 parts by mass of water) at a liquid temperature of 40° C. for 30 seconds (crosslinking treatment). Then, while the laminate was immersed in an aqueous boric acid solution (boric acid concentration 4 wt%, potassium iodide concentration 5 wt%) at a liquid temperature of 70°C, it was uniaxially stretched (stretching treatment in aqueous solution) in the longitudinal direction (length direction) between rollers with different circumferential speeds so that the total stretching ratio reached 5.5 times. Then, the laminated body was immersed in a cleaning bath (an aqueous solution prepared by blending 4 parts by mass of potassium iodide with respect to 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 approximately 90° C. while being brought into contact with a SUS heating roll whose surface temperature was maintained at approximately 75° C. (drying shrinkage treatment). Thus, a polarizer having a thickness of about 5 μm was formed on the resin substrate, thereby obtaining a laminate having a structure of resin substrate / polarizer. A TAC film (thickness 25 μm) as a first protective layer was bonded to the polarizer surface (the side 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) as a second protective layer was bonded to the exposed polarizer surface via an acrylic adhesive layer (thickness 5 μm). Thus, a polarizing plate having a structure of first protective layer / polarizer / second protective layer was obtained. 2. Preparation of laminated film A surface protective film (55 μm thick) was attached to the surface of the first protective layer of the polarizer obtained in 1. The surface protective film had a substrate (PET resin film) and an acrylic adhesive layer laminated on the substrate. In addition, a release liner (PET resin film provided with a release treatment layer) was attached to the surface of the second protective layer of the polarizer via an acrylic adhesive layer (20 μm thick, adhesive layer). Through the above operation, a film (optical laminate) having a structure of surface protection film / polarizer / adhesive layer / release liner was obtained. Next, the film (optical laminate) is laser cut into a desired shape and size. When viewed from the stacking direction, the film has a roughly rectangular shape. The size of the long side of the film is 165 mm and the size of the short side is 72 mm. In each embodiment and each comparative example, 250 such films are prepared. [Examples 1 to 4] like Figure 1 As shown in FIG. 250 , 250 laminated films are stacked on the lower pressing fixture to form a workpiece. Figure 2 As shown, when viewed from the stacking direction, the workpiece includes: a central area including the center of the workpiece, a cutting target area to be cut later, and a blank area between the central area and the cutting target area. The area of ​​the central area, the width of the cutting target area, and the width of the blank area are shown in Table 1. Next, the workpiece is clamped and fixed using the lower and upper pressing jigs. Figure 1 As shown in FIG. 1 , the upper pressing fixture is integrally provided with a protrusion having a contact surface and a main body having an opposing surface. The contact surface of the upper pressing fixture is in contact with the central area of ​​the workpiece as a whole, and the opposing surface of the upper pressing fixture is facing the blank area of ​​the workpiece as a whole. The interval between the contact surface and the opposing surface in the upper pressing fixture, and the interval between the opposing surface of the upper pressing fixture and the blank area of ​​the workpiece are shown in Table 1. In a state where the workpiece is fixed, the upper pressing jig presses the center area of ​​the workpiece so that the clamping pressure on the center area reaches the value in Table 1. The upper pressing jig does not substantially press the blank area and the cutting target area. The positional deviation (lamination deviation) of the plurality of laminated films included in the fixed workpiece was evaluated according to the following criteria. The results are shown in Table 1. ○: The offset of the stacked workpieces after clamping is less than 0.05 mm ×: The deviation of the stacked workpieces after clamping is 0.05 mm or more Next, the cutting target area of ​​the workpiece was cut by an end mill that could rotate and move relative to the lower pressing fixture. The cutting edge of the end mill was made of a cemented carbide, the HV hardness of the cutting edge was 1600, the torsion angle of the cutting edge was 30°, and the number of cutting edges was 2. In addition, the feed speed of the end mill was 3000 mm / min, and the rotation speed of the end mill was 35000 rpm. More specifically, when viewed from above (the side of the workpiece opposite to the lower pressing jig), the end mill rotates in the clockwise direction and moves relatively in the clockwise direction around the laminated film while contacting the end surface of the workpiece. In this way, a plurality of end surface processing films were manufactured at once. The dimensional accuracy of the plurality of end surface processed films produced in a batch was evaluated according to the following criteria. The results are shown in Table 1. ○: All the end surface processing films are within the expected size ±0.05mm △: All the end surface processing films are within ±0.05mm of the expected size and within ±0.1mm of the expected size ×: At least one of the plurality of edge surface processing films exceeds the desired dimension by ±0.1 mm The occurrence of cracks in a plurality of end surface processed films was evaluated according to the following criteria. The results are shown in Table 1. ○: No cracks were observed in the films with multiple end surfaces. △: Among the multiple end surface processed films, the proportion of end surface processed films with cracks is less than 10% ×: The proportion of the end surface processed films with cracks among the plurality of end surface processed films is 10% or more [Example 5] A plurality of end surface processed films were manufactured collectively in the same manner as in Example 1 except that the upper pressing jig was divided into a contact portion having a contact surface and a peripheral end portion having a facing surface. [Example 6] like Figure 5 As shown in the figure, the upper pressing fixture has only a contact surface and no opposing surface, and a plurality of end surface processing films are manufactured in the same manner as in Example 1. More specifically, in a state where the workpiece is fixed, the upper pressing fixture is in contact with the entire central area of ​​the workpiece, and on the other hand, it is not in contact with the blank area and the cutting target area of ​​the workpiece. In addition, the evaluation is performed in the same manner as in Example 1. [Examples 7 to 9] A plurality of end surface processing films were manufactured in a batch in the same manner as in Example 1 except that the width of the blank region was changed to the value shown in Table 1. Furthermore, the same evaluation as in Example 1 was performed. [Example 10] A plurality of end surface processing films were collectively manufactured in the same manner as in Example 1 except that the width of the blank area, the width of the cutting target area, and the interval between the opposing surface and the blank area were changed to the values ​​shown in Table 1. Evaluation was performed in the same manner as in Example 1. [Comparative Example 1] A plurality of end surface processing films were manufactured in a batch in the same manner as in Example 1 except that the upper pressing jig uniformly pressed the entire workpiece (central region, blank region, and cutting target region) while the workpiece was fixed. [Comparative Example 2] A plurality of end surface processing films were manufactured in the same manner as in Example 1 except that the interval between the contact surface and the opposing surface in the upper pressing jig was changed to the value shown in Table 1. More specifically, in a state where the workpiece was fixed, the upper pressing jig pressed the central area of ​​the workpiece so that the clamping pressure on the central area reached the value in Table 1, and substantially did not press the blank area and the cutting target area. In addition, the evaluation was performed in the same manner as in Example 1. [Table 1] [evaluate] It is clear from Table 1 that if the upper pressing jig presses the central area of ​​the workpiece while the workpiece is fixed, and does not substantially press the blank area and the cutting target area, the stacking deviation of the film contained in the fixed workpiece can be suppressed. In addition, if the interval between the opposing surface and the contact surface of the upper pressing jig and / or the interval between the opposing surface of the upper pressing jig and the blank area of ​​the workpiece is within a specific range, the dimensional accuracy of the end surface processing film can be improved, and the generation of cracks in the end surface processing film can be suppressed. Industrial Applicability The method for producing an edge surface processing film of the present invention can produce an edge surface processing film used in various industrial products. The edge surface processing film can be suitably used in display devices such as liquid crystal display devices, organic EL display devices, and inorganic EL display devices.

Claims

1. A method for manufacturing an end surface processing film, the method comprising: a step of placing a workpiece on a lower pressing fixture, wherein the workpiece is a workpiece formed by stacking a plurality of films; A fixing step of clamping the workpiece by the lower pressing jig and the upper pressing jig to fix the workpiece; and a cutting step of cutting the end surface of the fixed workpiece, The workpiece arranged in the arrangement step comprises, when viewed from the stacking direction, a central region including the center of the workpiece, a cutting target region to be cut in the cutting step, and a blank region between the central region and the cutting target region. In the fixing step, the upper pressing jig presses the central area and substantially does not press the blank area and the cutting target area.

2. The method for producing an end surface processing film according to claim 1, wherein: The width of the cutting target area is greater than or equal to 0.1 mm and less than or equal to 1.5 mm. The width of the cutting target area and the width of the blank area satisfy the following formula (1): 0.005≤(L1+L2) / a≤0.15···(1) In the formula (1), a represents the number of films stacked in the workpiece, L1 represents the width of the cutting target region [mm], and L2 represents the width of the blank region [mm].

3. The method for producing an end surface processing film according to claim 1 or 2, wherein: The upper pressing fixture has: a contact surface that contacts the central region during the fixing process; and The opposite surface facing the blank area during the fixing process.

4. The method for producing an end surface processing film according to claim 3, wherein: In a state where the workpiece is fixed, a distance between the blank area and the opposing surface in a stacking direction of the workpiece is greater than or equal to 0 mm and less than or equal to 1.0 mm.

5. The method for producing an end surface processing 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 the formula (2), a represents the number of films stacked in the workpiece, and L3 represents the distance [mm] between the contact surface and the opposing surface in the stacking direction of the workpiece.

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