Laminated film cutting method and cutting device

Abstract

To provide a method and a device for cutting a laminated film, which enable cutting into a desired shape by suppressing the length of cracks generated in a hard coat layer when the laminated film having the hard coat layer formed on the backside of at least a base material film is cut.SOLUTION: A cutting device 1 comprises cutters (first cutter 10 and second cutter 20) that cut a laminated film F having a hard coat layer on the back side of a base material film in a cutting direction. The cutters secure, at least as a removal width, a maximum width measured by test-cutting the laminated film F which is a maximum width of an area from a cut surface in which cracks have occurred from a cut surface of first cutting of real cutting carried out by the first cutter 10, and execute second cutting of the real cutting by the second cutter 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to cutting of laminated films used in optical display components and the like, and more particularly to a technique for cutting laminated films having at least a hard coat layer on the back side of the substrate film in the cutting direction. [Background technology]

[0002] Laminated films are widely used in optical display components such as liquid crystal televisions, organic EL televisions, electronic paper, touch panels, smartphones, etc. Here, an example of a laminated film will be described with reference to FIG.

[0003] The laminated film F shown in Figure 13 is formed from a base film F1, which is a functional film formed from a single layer or multiple layers, hard coat layers F21, F22 which serve as protective layers laminated on both the front and back surfaces so as to sandwich the base film F1, adhesive layers F31, F32 which are applied to the hard coat layers F21, F22 and are used to attach the laminated film F to an adherend, and separators F41, F42 which are peeled off when the laminated film F is attached to an adherend.

[0004] A technique for cutting such a laminated film is known, as described in Patent Document 1. The "Laminate Cutting Method, Laminate Cutting Apparatus, and Laminate Cutting Base" section of Patent Document 1 describes the use of a cutting base in which the mounting surface for the laminate has a ridge shape extending in the width direction of the laminate, or a cutting base with a convex curve centered on an axis extending in the width direction of the laminate. Because the convex curved base has a surface shape that generates tensile stress on the surface side of the laminate, when the cutting blade presses against the surface of the laminate, the compressive stress caused by the cutting blade at the pressed portion can be offset, achieving an equilibrium state in which no tensile or compressive stress is generated in the laminate. This prevents glue adhesion to the cutting blade, blocking, cracks, and chipping on the cut surface.

[0005] Furthermore, although it is not a laminated film but an optical fiber, a technique for improving the cut surface upon cutting is known, as described in Patent Document 2. The "Method for Cutting Plastic Optical Fiber Cable" in Patent Document 2 describes that when the first cut is made, the optical fiber is torn by the tensile force and cut in a broken state, making it difficult to obtain a smooth cut surface, but by moving the optical fiber or moving the cutting blade after the first cut is completed, the thickness of the cutting chips is small (approximately 0.1 mm to 0.3 mm), and the fiber is cut away while bending, resulting in a cut surface with high smoothness. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-142445 [Patent Document 2] Japanese Patent Publication No. 170904 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0007] In the "method for cutting a laminate, a device for cutting a laminate, and a base for cutting a laminate" described in Patent Document 1, the pressing portion applied to the surface of the laminate can be brought into an equilibrium state in which no tensile stress or compressive stress is generated in the laminate, and it is therefore presumed to have a certain effect in reducing cracks that occur during cutting. However, the cutting blade of the cutter is disposed above the top of the cutting table so as to be approximately perpendicular to the conveyance direction of the optical film. Therefore, although it is effective when cutting a strip-shaped laminated film in a straight line across the width, when cutting out a product in one go, cutting is done with a die-shaped cutting blade formed to cut out the desired product shape, so it is difficult to use a cutting base with a convex curved surface, and the degree of freedom in cutting is limited.

[0008] Furthermore, in the "Method for Cutting Plastic Optical Fiber Cable" described in Patent Document 2, the second cut is made at a point where the thickness of the chips is small, so that the chips are bent as they are cut away, resulting in a flat cut surface without breakage.

[0009] This is because the influence on the optical signal emitted from the cut surface of the optical fiber is important, and therefore it is important to be able to cut the cut surface smoothly. Optical fibers are made up of a core made of a high-refractive-index material such as polymethylmethacrylate (PMMA), polycarbonate, or polystyrene, and a cladding made of a low-refractive-index fluorine-based polymer such as polyvinylidene fluoride (PVDF). The cladding has a certain degree of tensile strength, so when the optical fiber is bent, it bends along with the core.

[0010] However, since laminated films are not used in a curved state, the hard coat layer for protecting the base film made of triacetyl cellulose (TAC), polyethylene terephthalate (PET), cyclic olefin polymer (COP), etc. is formed by curing, for example, an ultraviolet-curable resin, and therefore has high hardness.

[0011] Cracks may occur when cutting laminated films with a blade. The location and size of these cracks vary depending on the material of the laminated film, the composition of each layer, and its thickness. In particular, in a laminate film in which a hard coat layer for protecting a single-layer or multi-layer substrate film is laminated on one or both sides thereof, when a blade penetrates during cutting, the substrate film F1 is first broken by the volume of the blade's penetration. The blade edge then reaches the hard coat layer F22, but because the hard coat layer F22 is bonded to the substrate film F1, the hard coat layer F22 is pulled by the fracture of the substrate film F1 and breaks before the blade edge comes into contact with the hard coat layer F22. At this time, this fracture generates cracks extending from the cut surface (edge ​​surface) on both sides of the hard coat layer F22 separated by the fracture.

[0012] Therefore, when the edge of a laminated film is cut twice, a laminated film consisting of a substrate film and a hard coat layer of different hardnesses will have cracks on both sides of the cut position in the hard coat layer when cut the second time, just as it did when cut the first time.

[0013] Therefore, unlike plastic optical fibers, the problem is not the cut surface but rather the cracks in the hard coat layer that extend from the cut surface, so simply cutting the laminated film so that the thickness of the cut chips is thin during the second cut will not result in the desired cutting quality.

[0014] When cutting a laminate film, it is important to reduce the length of cracks that occur in the hard coat layer on the back side of the cutting direction of the substrate film in order to improve cutting quality. It is also important to ensure a high degree of freedom in cutting, such as cutting a strip-shaped laminate film into a desired contour shape, rather than just cutting it linearly along the width direction.

[0015] Therefore, an object of the present invention is to provide a method and apparatus for cutting a laminated film that, when cutting a laminated film having a hard coating layer formed on at least the back side of a base film, can reduce the length of cracks that occur in the hard coating layer and enable cutting into a desired shape. [Means for solving the problem]

[0016] The method for cutting a laminated film of the present invention is a method for cutting a laminated film having at least a hard coat layer laminated on the back side of a base film in the cutting direction, and is characterized by including the steps of: test-cutting the laminated film and measuring the maximum width of the crack area from the cut surface where a crack has occurred in the hard coat layer; performing a first main cut on the laminated film; and performing a second main cut, ensuring at least the maximum width as the removal width from the cut surface obtained by the first cut.

[0017] The laminated film cutting device of the present invention is a laminated film cutting device equipped with a blade for cutting a laminated film having at least a hard coating layer on the back side of the cutting direction of the base film, and is characterized in that the blade performs a test cut of the laminated film, securing at least the maximum width of the crack area from the cut surface where a crack has occurred in the hard coating layer as the removal width from the cut surface of the first main cut, and then performs the second main cut.

[0018] According to the present invention, first, the laminate film is test-cut. Then, for cracks occurring in the hard coat layer, the maximum width of the crack region from the cut surface is measured. Next, the first actual cut is performed. During the first cut, the cutting edge of the blade penetrates the substrate film while pushing it aside, and when it reaches the hard coat layer, a crack occurs in the hard coat layer in a crack region of the same maximum width as during the test cut. This crack weakens the adhesion between the substrate film and the hard coat layer, making the hard coat layer more susceptible to peeling in this region. Then, when performing the second cut, a removal width of at least this maximum width or greater is ensured from the cut surface of the first cut. By doing so, even if the substrate is cut away by the blade penetration during the second cut and breaks halfway, the hard coat layer is not affected because it peels off from the substrate, and the cutting edge hits the hard coat layer, resulting in a cut. This allows the crack to be kept shorter than the crack that occurred during the first cut. Furthermore, since the main cutting is done in two separate steps, the laminated film can be placed on a flat base and cut, and therefore a die-shaped blade formed to cut out the desired product shape can also be used.

[0019] The test cut is performed twice, and the removal width is increased for the second cut from the maximum width of the crack region generated by the first cut, and the removal width for the actual cut can be set to a width equal to or smaller than the position before the maximum width of the crack region generated in the second cut suddenly increases. This makes it possible to suppress the width of the crack region generated in the actual cut, thereby enabling the production of high-quality film pieces.

[0020] The first cut is made so as to leave a part of the laminated film, and the second cut allows the laminated film to be cut out. If the film is cut out during the first cut, chips of the width to be removed will be generated during the second cut. However, if part of the laminated film is left uncut during the first cut, the removed side will remain connected, preventing the generation of chips.

[0021] The blade can be moved from the position where the blade performed the first cut to the position where the blade performs the second cut, and the second cut can be performed by the blade.

[0022] It is also possible to cut the laminated film with a first blade at the first cutting position, and then cut the laminated film with a second blade at the second cutting position without changing the position of the laminated film.

[0023] In the laminated film cutting device of the present invention, the blades include a first blade that performs the first cut and a second blade that performs the second cut, and a cutout portion that accommodates a part of the second blade can be formed on the side of the first blade that faces the second blade by reducing the thickness of the first blade. A cutout is formed by thinning the thickness of the first blade on the side facing the second blade. A part of the second blade is housed in this cutout. By doing so, even if the gap between the cutting edges of the first blade and the second blade when they are overlapped is not enough to ensure the removal width, the cutting edges of the first blade and the second blade can be brought closer together by housing the second blade in the cutout.

[0024] The blade may be formed with a single blade, and may comprise a first blade for performing the first cut and a second blade for performing the second cut, and the back surface of the second blade may have a notch formed therein to reduce the thickness in the range from the cutting edge to the inclined surface. By forming a cutout portion that reduces the thickness of the second blade, the position of the blade back surface from the cutting edge can be closer to the first blade side than the position of the blade back surface on the main body. [Effects of the Invention]

[0025] The present invention can suppress cracks that occur in the first cut to be shorter than those that occur the first time, and even a cutting tool in the shape of a die formed to the contour of the product can be used as a cutting tool. Therefore, the present invention makes it possible to suppress the length of cracks that occur in the hard coat layer when cutting a laminate film having a hard coat layer formed at least on the back side of a base film, and to cut it into a desired shape. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a diagram showing a cutting device according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a flow chart for explaining a cutting method. [Figure 3] 1 is a diagram illustrating a crack region that occurs from the cut surface when the laminated film is cut. FIG. [Figure 4] FIG. 10 is a diagram showing a cutting device according to a second embodiment of the present invention. [Figure 5] 10(A) to 10(D) are diagrams illustrating the state of the second cutting when the removal width is set to be less than the width of the crack region in the first cutting. [Figure 6] These are the results when cutting using the cutting device shown in Figure 1, where (A) is a table showing the width of the crack area when the cutting edge distance between the first blade and the second blade is changed, and (B) is a graph showing (A). [Figure 7] 10A and 10B are diagrams showing blades of a cutting device according to a third embodiment of the present invention, where (A) shows a first blade with a notch formed therein, and (B) shows a second blade with a notch formed therein. [Figure 8] 10A and 10B are diagrams showing a cutting device according to a fourth embodiment of the present invention, in which (A) is a front view of the cutting device, and (B) is a cross-sectional view of the cutting device at an intermediate position in the depth direction. [Figure 9] 9A and 9B are diagrams showing a blade attached to the cutting device shown in FIG. 8, where (A) is a perspective view of the blade shown in FIG. 8B formed in a die shape, and (B) is a cross-sectional view with a portion of (A) cut away. [Figure 10] 9A and 9B are diagrams showing blades that can be attached to the cutting device shown in FIG. 8, in which (A) is a perspective view of the blade shown in FIG. 8A formed in a die shape, and (B) is a cross-sectional view of (A) with a portion cut away. [Figure 11] FIG. 11 is a cross-sectional view of a cutting device according to a fifth embodiment of the present invention at an intermediate position in the depth direction. [Figure 12] FIG. 13 is a cross-sectional view of a cutting device according to a sixth embodiment of the present invention at an intermediate position in the depth direction. [Figure 13] FIG. 2 is a schematic cross-sectional view illustrating the configuration of a laminated film. DETAILED DESCRIPTION OF THE INVENTION

[0027] [Embodiment 1] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A laminated film cutting method and cutting device according to an embodiment of the present invention will be described with reference to the accompanying drawings. The laminated film cutting method and cutting device according to the first embodiment involve cutting a strip of laminated film F shown in FIG. 13 in the longitudinal direction to cut out pieces of film according to the size required by the device to be mounted. The laminated film F may be, for example, a polarizing film having an optical function. The laminated film F has at least a hard coat layer F22 on the back side of the substrate film F1 in the cutting direction, and in the present embodiment 1, hard coat layers are provided on both sides of the substrate film.

[0028] [Explanation of laminated film cutting equipment] First, a cutting device used in the method for cutting a laminated film according to the present embodiment will be described. The cutting device 1 shown in Figure 1 includes a first blade 10, a second blade 20, a base 30 on which a laminated film F is placed, a lifting device (not shown) that raises and lowers the first blade 10 and the second blade 20, and a conveying device (not shown) that moves the laminated film F in a moving direction M1.

[0029] The second blades 20 adjacent to the first blade 10 are provided in pairs on the downstream side in the movement direction M1, and in pairs on the upstream side across the length L0 that will form the film piece to be cut out. The first blade 10 is used to perform the first test cut and the first main cut, and the second blade 20 is used to perform the first test cut and the second main cut. The first blade 10 and the second blade 20 are single-edged blades with inclined surfaces 10i and 20i formed on the side where the laminated film F is removed, which reduce the thickness of the blade body 10m and 20m. The first blade 10 and the second blade 20 are straight blades with linear cutting edges 10e and 20e. In the first embodiment, the first blade 10 and the second blade 20 are made of cemented carbide.

[0030] The base 30 has a flat mounting surface 30s on which the laminated film F is placed. A buffer material is arranged on the mounting surface 30s to receive the cutting edges 10e, 20e of the first blade 10 and the second blade 20 when they cut out the laminated film F. The buffer material can be, for example, a soft film, and the soft film can be, for example, a PET film with a thickness of 100 μm to 200 μm.

[0031] The lifting device can lower the first blade 10 and the second blade 20 during cutting and lift them after cutting. After the second cutting, the conveying device moves the strip-shaped laminated film F in a horizontal moving direction M1 (from left to right in FIG. 1).

[0032] [Explanation of how to cut laminated film] Next, a cutting method using this cutting device 1 will be described with reference to the drawings. As shown in Fig. 1, it is assumed that the laminated film F is located below the first blade 10 and the second blade 20. First, a test cut is performed with the first blade 10 (see step S10 in FIG. 2). This test cut is performed at the design stage of the cutting device 1 shown in FIG. 1, and the removal width determined by the test cut is set as the blade edge distance L1 when the cutting device 1 is manufactured. As shown in FIG. 3, the maximum width L of the region S (hereinafter referred to as the crack region S) from the cut surface C where the crack occurred by this test cutting is MAX is measured (see step S20).

[0033] Next, regarding the cutting edge distance L1 between the first blade 10 and the second blade 20 shown in FIG. MAX (see FIG. 3) is set as the removal width (see step S30). Here, the cutting edge distance L1 between the first blade 10 and the second blade 20 is the distance between the cutting edge 10e of the first blade 10 and the cutting edge 20e of the second blade 20.

[0034] Once the test cutting is complete, a new laminated film F from which a film piece to be a product is cut is set on the base 30 and actual cutting is carried out (see step S40). In the actual cutting, first, a first cut is made by the first blade 10 (see step S41). At this time, the first blade 10 cuts out the laminated film F. Then, the laminated film F is left in its original position. As shown in Figure 3, in this first cut, the laminated film F was cut from the cut surface C to the maximum width L MAX A crack area S occurs.

[0035] Next, a second cut is made by the second blade 20 (see step S42). In the crack region S of the laminate film F, the first cut makes it easy for the base film F1 and the hard coat layer F22 to peel off, as shown in Figure 13. Therefore, when the second cut is made with the second blade 20, the cutting edge 20e of the second blade 20 penetrates the base film F1 and applies pressure, causing the base film F1 to deform, but this deformation does not accompany the hard coat layer F22. Therefore, the cutting edge 20e of the second blade 20 reaches and cuts the hard coat layer F22 without breaking the hard coat layer F22, thereby keeping the crack that occurs in the first cut to a shorter length.

[0036] This second cut cuts the strip-shaped laminated film F at two locations in the length direction, and thus film pieces that will become the product are cut out. Next, it is determined whether a predetermined number of film pieces have been cut out (see step S43). When the predetermined number of images have been cut out, the process ends. If the predetermined number of pieces have not been cut out, the laminated film F is moved in the movement direction M1 by the conveying device (see step S44), and the process proceeds to step S41 to cut out the next film piece.

[0037] In this way, when the second cut is made, the crack can be kept shorter than the crack that occurs the first time, so that when cutting a laminated film having a hard coat layer formed on at least the back side of the base film, the length of the crack that occurs in the hard coat layer can be kept small. Furthermore, since the strip film is placed on the flat mounting surface 30s of the base 30 and moved in the movement direction M1 while the main cut is performed in two steps, the first blade 10 and the second blade 20 can be used as cutting blades whether they are straight blades as shown in Figure 1 or frame-shaped blades formed to the outline shape of the product. Therefore, the cutting device 1 can easily cut the laminated film F into a desired shape.

[0038] In the first embodiment, the maximum width L of the crack region S obtained by the test cutting in step S20 is also MAX If the removal width is set to (see Figure 3), the removal width can be minimized, allowing for effective use of laminated film F. However, the length at which the second crack occurs varies depending on the removal width. Therefore, two test cuts were made to observe the tendency for the width of the crack area to be narrower than the first cut. First, the maximum width of the crack area where a crack occurred in the first test cut was measured. Next, the removal width, which will be the position for the second cut, was increased from the maximum width of the crack area in the first cut, while the position for the second cut was changed. In this way, the maximum width of the crack area that occurred in the second cut was measured. The removal width that is equal to or smaller than the position before the maximum width of the crack area suddenly increased was determined to be the removal width for the actual cut. In this way, by setting the upper limit of the second cutting position to a position before the maximum width of the crack area increases suddenly, the width of the second crack area can be made smaller than the width of the first crack area, improving cutting quality while keeping the unnecessary removal width small.

[0039] The lifting device can lift and lower the first blade 10 and the second blade 20 separately, or can lift and lower the first blade 10 and the second blade 20 simultaneously by setting the position of the cutting edge 10e of the first blade 10 lower than the cutting edge 20e of the second blade 20 so that the first blade 10 begins to cut the laminated film before the second blade 20. When the first blade 10 and the second blade 20 are raised and lowered separately, two lifting devices are required, one for the first blade and one for the second blade. However, although chips of the removal width are generated when the second cutting is performed with the second blade 20, the chips are easy to remove because the first blade 10 and the second blade 20 are raised and lowered independently. When the first blade 10 and the second blade 20 are raised and lowered simultaneously, chips of the removal width that are generated when the second cutting is performed by the second blade 20 may become caught between the first blade 10 and the second blade 20 and be difficult to remove. However, one lifting device is sufficient to raise and lower both blades, making control easy and reducing costs.

[0040] [Embodiment 2] A laminated film cutting method and cutting device according to a second embodiment of the present invention will be described with reference to Fig. 4. In Fig. 4, the same components as those in Fig. 1 are designated by the same reference numerals and will not be described. Fig. 4 also shows the combination of one of the first blade 10 and the second blade 20, and does not show the combination of the other blade.

[0041] 2, the first cut in the main cutting shown in step S41 cuts out the laminated film F. Therefore, scraps are generated according to the interval between the first cut and the second cut. In the cutting device 2 (see FIG. 4) according to the second embodiment, in the first cut, the first blade 10 cuts the laminate film F leaving a portion of the laminate film F in the thickness direction (hereinafter, cutting the laminate film leaving a portion of the laminate film may be referred to as a "half cut"). Then, in the second cut, the second blade 20 cuts out the laminate film F. By doing so, the unnecessary portion of the laminate film F, that is, the removal side, cannot be cut off in the first cut, and in the second cut, the width of the laminate film F to be removed is separated by the cutting of the second blade 20, so no cutting waste is generated according to the distance between the first and second blades. One method of leaving part of the laminate film F is to leave the separator F21 on the back side of the laminate film F in the cutting direction.

[0042] This cutting method can be achieved by having the lifting device that controls the elevation of the first blade 10 lower the first blade 10 to a lowering position taking into consideration the thickness of the laminated film.

[0043] (Example) The laminated film was cut using a cutting device 2 shown in FIG. The laminated film F has the structure shown in Fig. 13. A four-axis linear servo press machine manufactured by HODEN SEIMITSU was used as the cutting device. The first blade 10 and the second blade 20 shown in FIG. 1 were single-edged blades with a main body 10m, 20m having a thickness of 1.0 mm and a blade angle θ of the cutting edges 10e, 20e of 20°. The thickness of the main body 10m, 20m of the blade 20 and the blade angle θ of the cutting edges 10e, 20e can be determined depending on the laminate film to be cut, and can be, for example, 0.4 mm to 1.0 mm. In this example, the cutting speed was set to 3 mm / s. Because of the blade thickness, the first blade 10 and the second blade 20 could not be brought closer together on the order of μm. Therefore, the same blade was used. After the first cut was completed, the blade was moved to the second cut position and the second cut was performed.

[0044] In the test cutting, first, the laminate film F was cut several centimeters from the end face with the first blade 10. This cut was made while leaving a part of the laminate film F. In this example, the base film F1 was cut out, and a half cut was made down to the hard coat layer F22.

[0045] As a result, a crack with a maximum width of 40 μm (crack area S shown in Figure 3) occurred from the cut surface. Therefore, the removal width can be set to 40 μm, minimizing waste. Then, when a second cut was made and the length of the crack that occurred (width of the crack area) was measured, the removal width was increased and the relationship between the removal width (cutting edge distance) and the width of the crack area was measured. In this measurement, the distance between the cutting edges 10e, 20e of the first blade 10 and the second blade 20 was changed from 30 μm, which is smaller than the maximum width of the crack region of 40 μm where the crack occurred, to 100 μm.

[0046] When the blade tip distance is set to 30 μm, which is shorter than the removal width of 40 μm, the blade tip 20 e attempts to penetrate the surface of the end T of the laminate film F as shown in Fig. 5(A), but as shown in Fig. 5(B), the end T of the soft laminate film F is crushed due to elastic deformation caused by the pressure of the blade tip 20 e, and is unable to penetrate the laminate film F. Then, as shown in Fig. 5(C), the blade tip 20 e penetrates the end and cuts it out while crushing the end T of the laminate film F, and the crushed end T elastically returns to its original state as shown in Fig. 5(D). In this way, when the removed width was set to 30 μm, which is narrower than the width of the crack region obtained during the test cutting, the cross section became irregular and cutting failed.

[0047] Furthermore, as shown in Figure 6(A), when the cutting edge spacing was 40 μm, the width of the crack region was 16 μm. When the cutting edge spacing was 50 μm, the width of the crack region was 15 μm. When the cutting edge spacing was 60 μm, the width of the crack region was 17 μm. When the cutting edge spacing was 70 μm, the width of the crack region was 23 μm. Furthermore, it was initially assumed that the width of the crack region would gradually increase as the cutting edge spacing was further increased. However, as shown in Figure 6(B), when the cutting edge spacing was set to 80 μm, the width of the crack region suddenly increased to 37 μm. Therefore, it is desirable to set the maximum removal width to a position (cutting edge distance of 70 μm or less) below the position before the crack region suddenly increases, at the position of the cutting edge 20e of the second blade 20. By doing so, the width of the crack region can be reduced, allowing high-quality film pieces to be produced and reducing the amount of removed width that is discarded and wasted. Furthermore, it is more desirable that the removal width be set at a position where the crack area is smallest (cutting edge distance of 50 μm).

[0048] [Embodiment 3] A blade used in a laminated film cutting device according to a third embodiment of the present invention will be described with reference to FIG. As shown in FIG. 7(A), in the blade of the cutting device according to the third embodiment, a notch 11n is formed on the blade back surface 11b of the first blade 11. The cutout portion 11n is formed on the second blade 20 side of the first blade 11 by reducing the thickness of the first blade 11 so as to accommodate a part of the second blade 20 therein. In the first blade 11 according to the third embodiment, the blade front surface 20f including the inclined surface 20i of the second blade 20 is housed in the cutout portion 11n. By doing so, even if the distance between the cutting edges of the first blade 11 and the second blade 20 cannot ensure the removal width when the first blade and the second blade are overlapped, the distance between the cutting edges 11e of the first blade 11 and the cutting edge 20e of the second blade 20 can be made closer, and the cutting angle of the cutting edge 11e of the first blade 11 and the thickness of the inclined surface 11i (ridge) portion can be ensured. Therefore, even if the removal width is minute, the first blade 11 and the second blade 20 can accommodate it.

[0049] In this first blade 11, a jaw portion 11j is formed in the cutout portion 11n, which abuts from below against the inclined surface 20i of the second blade 20. Therefore, if the first blade 11 waits above the laminated film after the first cut, the second blade 20 cannot descend and cannot perform the second cut. Therefore, when the first blade 11 cuts the laminated film for the first time, it remains in the lowered position and waits until the second blade 20 makes the second cut. This allows the second blade 20 to perform cutting without the first blade 11 getting in the way.

[0050] In the blade shown in FIG. 7(B), the back surface 21b of the second blade 21 is formed with a notch 21n that reduces the thickness in a range from the cutting edge 21e to the inclined surface 21i. By forming the cutout portion 21n in this way in the second blade 21, the position of the blade back surface 21b due to the cutout portion 21n, which rises vertically from the cutting edge 21e, can be moved closer to the first blade 10 than the position of the blade back surface 21b of the main body 21m. Therefore, the distance between the cutting edge 10e of the first blade 10 and the cutting edge 21e of the second blade 21 can be made closer, so that even if the removal width is very small, the first blade 10 and the second blade 21 can accommodate it.

[0051] [Embodiment 4] A laminated film cutting device according to a fourth embodiment of the present invention will be described with reference to the drawings. In the cutting device 3 according to the fourth embodiment shown in Figures 8(A) and 8(B), the first blade and the second blade are formed into a cut-out shape (frame shape) that matches the outline of the film piece to be cut out as the product.

[0052] The cutting device 3 has a die set 41 formed by one die (lower die 41L) with a base 30 installed on the top surface, and the other die (upper die 41U) with blades (first blade, second blade) arranged with their cutting edges facing downward. The upper die 41U is guided by guide posts 42 arranged between the lower die 41L and the upper die 41U at the four corners of the die set 41, and is raised and lowered by a lifting device (not shown).

[0053] The blades arranged in the upper die 41U and shown in FIGS. 9(A) and 9(B) are formed by the first blade 10 and the second blade 21 shown in FIG. 7(B). Since the first blade 10 and the second blade 21 are formed in a rectangular frame shape, the film piece is cut out in a rectangular shape.

[0054] As shown in Figures 9(A) and 9(B), the first blade 10 and the second blade 21 are formed so that the inclined surfaces 10i, 21i (blade front surfaces 10f, 21f) face outward and the blade back surfaces 10b, 21b along the cutting direction (vertical direction) face inward.

[0055] By forming the first blade 10 and the second blade 21 in this way, a film piece to be used as a product can be cut out by a single main cut. Furthermore, since the laminated film F is placed on the flat mounting surface 30s of the base 30, it can be used even if the first blade 10 and the second blade 21 are formed in a frame shape.

[0056] In the fourth embodiment, the film piece to be cut out is rectangular, so the first blade 10 and the second blade 21 are formed in a rectangular frame shape, but the first blade and the second blade can be formed in a frame shape that matches the contour shape of the film piece, thereby making it possible to cut out a film piece in a desired shape.

[0057] In the cutting device 3 of embodiment 4 shown in Figures 8(A) and 8(B), the blades shown in Figures 9(A) and 9(B) are formed by the first blade 10 and the second blade 21 shown in Figure 7(B), but they can also be formed by the blades shown in Figures 10(A) and 10(B). This blade is a combination of a first blade 11 and a second blade 20 shown in FIG. 7(A).

[0058] In this way, the blades of the cutting device 3 can be a combination of the first blade 11 and the second blade 20 shown in Fig. 7(A) or a combination of the first blade 10 and the second blade 21 shown in Fig. 7(B). This allows the blade edges 11e, 20e and the blade edges 10e, 21e to be positioned close to each other, making it possible to cut a film piece into a desired shape even if the removal width is very small.

[0059] [Embodiment 5] A laminated film cutting method and cutting device according to a fifth embodiment of the present invention will be described with reference to the drawings. 1, 4, 7, and 8, when two cuts are made by first blades 10 and 11 for the first cut and second blades 20 and 21 for the second cut, the cuts are made without moving either the blades or the laminated film. However, in a cutting device 4 according to a fifth embodiment shown in Fig. 11, the first blade 12 and the second blade 22 are arranged side by side along the direction in which the laminated film F is transported (movement direction M2).

[0060] The first blade 12 is disposed with the cutting edge 12e facing downward in an upper die 43U of the first die set 43 on the upstream side of the movement direction M2. The first die set 43 also includes a lower die 43L disposed below the upper die 43U and facing the upper die 43U. The second blade 22 is disposed with the cutting edge 22e facing downward in an upper die 44U of the second die set 44 on the downstream side of the movement direction M2. The second die set 44 includes a lower die 44L disposed below the upper die 44U and facing the upper die 44U.

[0061] Guide posts 45 for guiding the elevation of the upper dies 43U, 44U are provided between the upper dies 43U, 44U and the lower dies 43L, 44L of the first die set 43 and the second die set 44. These guide posts 45 allow the first die set 43 and the second die set 44 to be elevated and lowered independently of each other.

[0062] A base 31 is disposed on the top surfaces of the lower dies 43L and 44L, straddling the top surfaces of the lower dies 43L and 44L. The laminated film F is placed on this base 31, and the laminated film F is slid on the base 31 and fed in the moving direction M2 by a conveying device (not shown).

[0063] The cutting device 4 according to the fifth embodiment is configured as described above, and can be operated by the following cutting method. First, the first blade 12 descends to perform the first cut on the laminate film F positioned below the first blade 12. This cut is a half cut that leaves the separator F41 (see FIG. 13) on the lower side of the laminate film F. Next, the laminate film F is fed in the movement direction M2, and the portion half-cut by the first blade 12 is positioned below the second blade 22. Then, the second blade 22 descends to perform the second cut.

[0064] The lifting and lowering of the first blade 12 and the second blade 22, as well as the conveyance and cutting positioning of the laminated film F, are controlled by a control unit (not shown). In this way, the cutting device 4 can cut the strip-shaped laminate film wound in a roll while unwinding it in one direction (the conveying direction) to cut out film pieces.

[0065] [Embodiment 6] A laminated film cutting method and cutting device according to a sixth embodiment of the present invention will be described with reference to the drawings. In a cutting device 5 according to the fifth embodiment shown in FIG. 12, a first blade 12 and a second blade 22 are arranged on a moving table 50 that reciprocates along a moving direction M3. The laminated film F is placed on a base 30, and is slid on the base 30 by a conveying device (not shown), and is fed in the direction from the front to the depth in FIG.

[0066] The first blade 12 and the second blade 22 are arranged with the cutting edge 12e facing downward in an upper mold 46U of a die set 46. The die set 46 also includes a lower mold 46L that is arranged below the upper mold 46U and faces the upper mold 46U.

[0067] The die set 46 has a guide post 47 between the upper mold 46U and the lower mold 46L to guide the upper mold 46U in ascending and descending motion. The guide post 47 allows the die set 46 to ascend and descend.

[0068] The cutting device 5 according to the sixth embodiment is configured as described above, and can be operated by the following cutting method. First, the first blade 12 descends to perform the first cut on the laminate film F located below the first blade 12. This cut is a half cut that leaves the separator F41 on the lower side of the laminate film F. Next, the laminate film F is fed so that the portion of the laminate film F that was half cut by the first blade is located below the second blade 22. Then, the second blade 22 descends to perform the second cut.

[0069] In this way, similarly to the fifth embodiment, the cutting device 5 can cut the strip-shaped laminate film wound in a roll while unwinding it in one direction (transport direction) to cut out film pieces. [Industrial Applicability]

[0070] The present invention can reduce the width of the crack area that occurs when cutting a laminate film that has at least a hard coat layer on the back side in the cutting direction of the base film, and is therefore suitable for producing high-quality laminate films used in optical display components, etc. [Explanation of symbols]

[0071] 1,2,3,4,5 Cutting device 10, 11, 12 First blade 20, 21, 22 Second blade 10b,11b,21b Back side of blade 10e,11e,12e,20e,21e,22e Cutting edge 10f, 20f, 21f Blade front surface 10i,20i,21i Slope 10m, 20m, 21m main body 11n, 21n Notch 11j Jaw 30, 31 Foundation 30s Placement surface 41 Die Set 41L lower mold 41U upper mold 42 Guidepost 43 First die set 43L lower mold 43U upper type 44 Second Die Set 44L lower mold 44U upper type 45 Guidepost 46 die sets 46L lower mold 46U upper type 47 Guidepost 50 Mobile Table C Cut surface S region (crack region) F Laminated film F1 base film F21, F22 hard coat layer F31,F32 Adhesive layer F41, F42 separator T end L0 length L1 Cutting edge spacing M1,M2,M3 moving direction

Claims

1. A method for cutting a laminated film, comprising: cutting a laminated film having at least a hard coat layer laminated on a back surface side of a substrate film in a cutting direction; a step of test-cutting the laminated film and measuring the maximum width of a crack region from a cut surface where a crack has occurred in the hard coat layer; a step of performing a first main cutting on the laminated film; and performing a second cut while ensuring that at least the maximum width is removed from the cut surface obtained by the first cut.

2. The laminated film cutting method of claim 1, wherein two cuts are made as the test cut, and the removal width that becomes the second cut position is gradually increased from the maximum width of the crack area generated by the first cut to change the second cut position, and the maximum width of the crack area generated during the second cut at each removal width is measured, and based on the measurement results, the removal width for the actual cut is set to be the removal width that is smaller than the removal width at which the maximum width of the crack area begins to increase rapidly.

3. The first cutting is performed while leaving a part of the laminated film, 3. The method for cutting a laminated film according to claim 1, wherein the laminated film is cut out in the second cutting.

4. 4. The method for cutting a laminated film according to claim 1, wherein the blade is moved from the position where the first cut was made to the position where the second cut is made, and the second cut is made by the blade.

5. 4. A method for cutting a laminated film according to claim 1, wherein the laminated film is cut with a first blade at the first cutting position, and then cut with a second blade at the second cutting position without changing the position of the laminated film.

6. A laminated film cutting device equipped with a blade for cutting a laminated film having at least a hard coat layer on the back side of a substrate film in the cutting direction, The blade cuts the laminated film to the hard coat layer. A laminated film cutting device that secures, from the first cut surface in the main cutting, at least the maximum width of the crack area from the cut surface where the crack occurred as the removal width, and then performs the second main cutting.

7. The blades include a first blade that performs the first cutting and a second blade that performs the second cutting, 7. The laminated film cutting device according to claim 6, wherein a cutout portion for accommodating a part of the second blade is formed on the side of the first blade facing the second blade by reducing the thickness of the first blade.

8. The blade is formed with a single blade and includes a first blade that performs the first cutting and a second blade that performs the second cutting, 7. The laminated film cutting device according to claim 6, wherein a notch for reducing the thickness is formed on the back surface of the second blade in a range from the cutting edge to the inclined surface.

Images