Manufacturing method and manufacturing apparatus of optical film laminate with no bulge part at laser beam-cut part

Abstract

To provide a manufacturing method of an optical film laminate in which substantially no bulge is generated at an edge of a cut portion even if cut by a laser beam.SOLUTION: The method conveys a raw material laminate including a first resin film laminated on one side of an optical functional layer including one or more films and a second resin film laminated on the other side thereof. A first substrate is laminated on the first resin film of the raw material laminate and a second substrate is laminated on the second resin film to obtain a raw material laminate with substrates on both sides. Static electricity is charged on the raw material laminate, the first substrate, the second substrate, or the raw material laminate with substrates on both sides, or on a plurality of these, so that the first substrate, the second substrate, and the raw material laminate are closely adhered, thereafter a cut face of an arbitrary shape is formed on the raw material laminate, using a laser beam. The static electricity is removed from the raw material laminate with substrates on both sides, and the first substrate and the second substrate are separated from one or more optical film laminates having the cut face of the arbitrary shape.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a manufacturing technique for an optical film laminate. More specifically, the present invention relates to a method and apparatus for manufacturing an optical film laminate in which, by cutting an optical film laminate before cutting with a laser beam in a state where base films are electrostatically adhered to both surfaces thereof, substantially no raised portions are formed at the ends of the cut portions.

Background Art

[0002] In optical display devices such as liquid crystal display devices and organic EL display devices, various optical film laminates such as polarizing films and retardation films are used. In the manufacture of conventional optical film laminates, a plurality of different processes are employed according to the use and shape of the final product.

[0003] For example, in the manufacturing process of an optical film laminate used for a smartphone, a long web-shaped laminate having a predetermined width in which a plurality of films are laminated is fed out, and the laminate is cut to a predetermined length using a circular blade to obtain a plurality of rectangular optical film laminates. Alternatively, in the manufacturing process of an optical film laminate used for in-vehicle applications or smartwatch applications, the demand for which has been increasing in recent years, a long web-shaped laminate having a predetermined width is fed out and punched using a Thomson type to obtain a plurality of optical film laminates having an arbitrary shape. In any of these processes, instead of a long web-shaped laminate, a sheet-shaped laminate may be used, or a sheet-shaped mother laminate from which a plurality of optical film laminates can be obtained may be used. The plurality of optical film laminates thus obtained are stacked and the end faces are processed as necessary, and then packaged and shipped.

[0004] However, if various processes are adopted according to the use and shape of the final product in this way, different manufacturing apparatuses need to be introduced for each use and shape, and individual correspondence to each manufacturing apparatus is required, which will lead to an increase in manufacturing costs. Therefore, regardless of the use and shape of the final product, it is desirable to realize a unified manufacturing process. In order to realize a unified manufacturing process, it is preferable to adopt a method of cutting the laminate using laser light instead of a circular cutting tool or a Thomson type.

[0005] When cutting a long web-shaped or sheet-shaped laminate with laser light, a bulge (ridge) may occur at the end of the cut laminate, or fume (fine dust formed by aggregation of vapor generated during melting) may adhere to the end. When a ridge occurs at the end, when a plurality of optical film laminates are stacked with their edges aligned, the ridges of the respective optical film laminates may be displaced from each other, or there may be a problem with image recognition. As a result, there is a risk of problems such as packaging defects at the time of shipment, alignment problems when bonding to a liquid crystal cell or an organic EL cell in a subsequent process, or problems when removing each optical film laminate one by one from a plurality of stacked optical film laminates.

[0006] Also, for example, when peeling off a surface protection film from an optical film laminate having a surface protection film in a subsequent process, usually, the surface protection film can be peeled off by pulling up a peeling tape adhered to its surface. However, if there is a ridge at the end of the optical film laminate (in this case, the end of the surface protection film), the contact area between the end of the peeling tape and the surface of the surface protection film becomes smaller compared to when there is no ridge, and there may be a case where the surface protection film cannot be peeled off even by pulling up the peeling tape.

[0007] Patent Document 1 proposes a method for removing fume generated when cutting a multilayer optical film with laser light. However, Patent Document 1 does not disclose the generation of a ridge at the end of the cut laminate and its solution means when cutting a multilayer optical film with laser light.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] In view of the above problems, an object of the present invention is to provide a method and an apparatus for manufacturing an optical film laminate in which substantially no raised portions are generated at the ends of the cut portions even when the laminate is cut by laser light.

Means for Solving the Problems

[0010] The inventors of the present invention laminated a base film on both sides of a laminate (raw material laminate) before being cut by laser light, charged and adhered them to each other using static electricity, and then cut them by laser light, and found that substantially no raised portions were generated at the ends of both sides on which the base film was laminated.

[0011] In one aspect, the present invention provides a method for manufacturing an optical film laminate of any shape, in which a first resin film is laminated on one side of an optical functional layer including one or more films, and a second resin film is laminated on the other side. In this method, first, a raw material laminate in which a first resin film is laminated on one side of an optical functional layer including one or more films and a second resin film is laminated on the other side is conveyed. Next, a first base material is laminated on the first resin film of the raw material laminate, and a second base material is laminated on the second resin film to obtain a raw material laminate with both-sided base materials. Next, by charging static electricity to the raw material laminate, the first base material, the second base material, or the raw material laminate with both-sided base materials, or a plurality of these, after adhering the first base material and the second base material to the raw material laminate, a cutting surface of any shape is formed on the raw material laminate using a laser beam. A step of removing static electricity from the raw material laminate with both-sided base materials and peeling the first base material and the second base material from one or more optical film laminates having a cutting surface of any shape is performed.

[0012] In another aspect, the present invention provides an apparatus for manufacturing an optical film laminate of any shape, in which a first resin film is laminated on one side of an optical functional layer including one or more films, and a second resin film is laminated on the other side. The apparatus includes a conveying device for conveying a raw material laminate in which a first resin film is laminated on one side of an optical functional layer including one or more films and a second resin film is laminated on the other side, a laminating device for laminating a first base material on the first resin film of the raw material laminate and a second base material on the second resin film to produce a raw material laminate with both-sided base materials, a charging device for charging static electricity to the raw material laminate, the first base material, the second base material, or the raw material laminate with both-sided base materials, or a plurality of these in order to adhere the first base material and the second base material to the raw material laminate, a laser cutting device for cutting the raw material laminate of the raw material laminate with both-sided base materials to form one or more optical film laminates of any shape, a static eliminator for removing static electricity from the raw material laminate with both-sided base materials, and a peeling device for peeling the first base material and the second base material from one or more optical film laminates of any shape.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0015] (Configuration of an optical film laminate without raised portions) FIG. 1 shows a schematic cross-sectional view of an optical film laminate having substantially no raised portions at the ends cut by laser light according to an embodiment of the present invention. FIG. 1(a) is a schematic cross-sectional view of an optical film laminate F1 having substantially no raised portions on both surface 11 and surface 13. Further, FIG. 1(b) is a schematic cross-sectional view showing a state in which the raw material laminate RM is cut by laser light.

[0016] Here, the "optically film laminate substantially without protrusions" in this specification refers not only to an optically film laminate having no protrusions at all (i.e., the height of the protrusions is 0 μm) at the end cut by laser light, but also to an optically film laminate having slight protrusions (typically the height of the protrusions is 10 μm or less, but not limited thereto) to such an extent that the above-mentioned problems caused by the protrusions, i.e., problems such as displacement during lamination, defects during image recognition, and defects in peeling of the surface protection film during peeling tape lifting, do not occur.

[0017] The optically film laminate F1 can be manufactured by the manufacturing method described later according to the present invention. For example, the base films BF1 and BF2 are laminated on both sides of a web-shaped raw material laminate RM, and the raw material laminate RM is adhered to the base films BF1 and BF2 by charging static electricity, and is obtained by cutting using laser light. FIG. 1(a) shows the state of the cut portion viewed from the side (the state viewed from the lower left obliquely in FIG. 1(b)). The portions of each reference numeral in FIG. 1(b) correspond to the portions of the reference numerals in FIG. 1(a).

[0018] The optical film laminate F1 is a laminate in which a surface protection film PF is laminated on one side of a polarizing film POL, and a release liner RL is laminated on the other side. In this specification, the optical film laminate having this configuration will be described as an example, but the optical film laminate to which the present invention can be applied is not limited thereto. The optical film laminate may, for example, have an optical functional layer composed of a plurality of films instead of a polarizing film. Further, the optical film laminate may be a laminate in which a release liner RL is laminated on one side of the optical functional layer, and surface protection films PF are laminated on multiple sides. The optical functional layer can be, for example, a polarizing film, a retardation film, a combination of a polarizing film and a retardation film, an OCA (Optical Clear Adhesive), a combination of a polarizing film and an OCA, a PET film, or the like. Alternatively, the optical film laminate can be, for example, a laminate in which a light release liner is laminated on one side of an OCA and a heavy release liner is laminated on the other side, or a laminate in which a light release liner is laminated on one side of a PET film and a heavy release liner is laminated on the other side.

[0019] The optical film laminate F1 can be cut out as a laminate having an arbitrary shape, for example, from a web-shaped raw material laminate RM using laser light. The arbitrary shape includes not only shapes such as a quadrangle, a circle, and an ellipse, but also irregular shapes. The irregular laminate can include, for example, a shape having a notch or a recess (so-called notch) on any one of the sides of a quadrangular shape, a pillow shape used for an automotive instrument panel, a shape in which holes such as a circle or a quadrangle are provided in a part of a quadrangular film, and other special-shaped laminates. For example, in the case of a laminate having a notch or a recess (so-called notch) on any one of the sides of a quadrangular shape, the cutting surface by laser light is formed not only on each side but also inside the notch or the recess.

[0020] The optical film laminate F1 has substantially no raised portions at the end 11a of the surface 11 on the surface protection film PF side or at the end 13a of the surface 13 of the release liner RL. The end 11a includes the edge 11b (FIG. 1(c)) of the cut portion of the surface 11 of the optical film laminate F1 and the vicinity inside thereof. The same applies to the end 13a.

[0021] In the method for manufacturing an optical film laminate according to the present invention, as will be described later, before cutting the raw material laminate RM with a laser beam, a base film BF1 is laminated on the surface 11 on the surface protection film PF side, and a base film BF2 is laminated on the surface 13 on the release liner RL side to form a raw material laminate RMB with base films on both sides, and the raw material laminate RMB with base films on both sides is charged with static electricity. Due to the static electricity, the surface 11 of the surface protection film PF of the raw material laminate RM and the base film BF1 are in close contact, and the surface 13 of the release liner RL and the base film BF are in close contact. Therefore, when the raw material laminate RMB with base films on both sides is cut in this state, substantially no raised portions are generated on either the surface 11 or the surface 13 of the raw material laminate RM. Also, no fumes are generated on the surfaces 11 and 13. Here, close contact means a state in which there is no air layer or air pocket between the two films, and such an air layer or air pocket is not formed even when being conveyed. If the surface 11 of the surface protection film PF and the base film BF1 are completely in close contact, and the surface 13 of the release liner RL and the base film BF2 are completely in close contact, there is no space where a physical raised portion can occur, and also, since the heat during cutting with a laser beam is less likely to conduct to the base film BF and the surface layer temperature is less likely to rise, substantially no raised portions are generated on the surfaces 11 and 13.

[0022] The optical film laminate F1 has an end face 15 which is a cut surface cut by laser light. The end face 15 is located between the edge 11b of the surface 11 and the edge 13b of the surface 13 of the optical film laminate F1. The end face 15 is typically an inclined surface due to the characteristics of the formation of the cut surface by laser light, but is not limited thereto, and may be a surface perpendicular to the surfaces 11 and 13. The end face 15 is represented as a flat surface in Fig. 1(a), but is not limited thereto. When the optical film laminate F1 has an arbitrary shape according to the application, the end face 15 may be a curved surface or a combination of a flat surface and a curved surface.

[0023] (Process for manufacturing the optical film laminate according to the present invention) Fig. 2 is a conceptual diagram of a process for manufacturing an optical film laminate F1 having no raised portions in practice. In Fig. 2(a), a base film BF1 is laminated on one surface of a raw material laminate RM, and a base film BF2 is laminated on the other surface to obtain a raw material laminate RMB with base films on both sides. The raw material laminate RM is a laminate in which a surface protection film PF is laminated on one surface of a polarizing film POL, and a release liner RL is laminated on the other surface, and may be either web-shaped or sheet-shaped.

[0024] As the base films BF1 and BF2 (collectively sometimes referred to as base film BF), either a non-adhesive material without an adhesive layer or an adhesive material may be used. Both of the base films BF1 and BF2 may be non-adhesive materials or adhesive materials, or one may be a non-adhesive material and the other an adhesive material. In the manufacturing method according to the present invention, since the raw material laminate RM and the base film BF are adhered by static electricity, a non-adhesive material can be used as the base film BF. Therefore, for example, it is possible to reuse the base film BF2 used in the process of manufacturing the optical film laminate according to the present invention or use waste materials used in other processes or products, and a reduction in the amount of base film used and a reduction in manufacturing costs can be expected. The non-adhesive base film BF that can be used in the present invention may be a film that is difficult to stretch even when tension is applied. As the base film BF, for example, a polyethylene terephthalate (PET) film, a polyethylene film, etc. can be used.

[0025] On the other hand, when an adhesive material is used as the base film BF, since the raw material laminate RM and the base film BF can be adhered more firmly, it is possible to more effectively prevent the generation of raised portions on the surface where the base film BF is laminated. However, when an adhesive material is used, it is difficult to reuse the once-used base film BF, the amount of material used increases, and thereby the manufacturing cost may increase. Also, when the adhesive force of the material used is greater than the adhesive force between the films of the raw material laminate RM, there is a risk that the base film BF cannot be peeled off even when trying to peel it, or the films of the raw material laminate RM may peel off. Therefore, the adhesive base film BF is preferably a weakly adhesive material, and for example, a surface protective material AW303EB manufactured by Nitto Denko Corporation can be used.

[0026] Next, as shown in FIG. 2(b), an electrostatic charge is applied to the raw material laminate RMB with both-sided substrates in which the raw material laminate RM, the base films BF1 and BF2 are laminated (40). By applying the electrostatic charge, the raw material laminate RM and the base film BF can be adhered to each other (FIG. 2(c)). As shown in FIGS. 2(b) and 2(c), for example, even if there is a portion V1 protruding toward the base film BF1 side in the raw material laminate R, the protruding portion V1 can be eliminated by applying an electrostatic charge to adhere the raw material laminate RM and the base film BF1. Further, even if there is a portion V2 where the raw material laminate RM is separated from the surface of the base film BF2, the separated portion V2 can be eliminated by applying an electrostatic charge to adhere the raw material laminate RM and the base film BF2. The application of the electrostatic charge is not limited to being performed on the raw material laminate RMB with both-sided substrates, and may be performed on the raw material laminate RM before being laminated with the base films BF1 and BF2, or may be performed on the base film BF1 or BF2 or both of them before being laminated with the raw material laminate RM. Although not shown, when applying an electrostatic charge to the raw material laminate RMB with both-sided substrates, it is preferable that the portion to be charged of the raw material laminate RMB with both-sided substrates is brought into contact with a conductor such as a metal roller, and a charging device is arranged on the side opposite to the metal roller so as to face the contacted portion for charging.

[0027] It is preferable to uniformly charge the static electricity on the entire surface of the raw material laminate RM and the base films BF1 and BF2. The amount of static electricity to be charged is such that the base films BF1 and BF2 and the raw material laminate RM do not peel off (the adhesion is not lost) during conveyance and when forming the cut surface by the laser beam 41. The amount of static electricity is preferably -10 kV or more and -0.5 kV or less, or 0.5 kV or more and 10 kV or less, more preferably -4.0 kV or more and -0.5 kV or less, and most preferably -4.0 kV or more and -0.5 kV or less. When the amount of static electricity is less than -10 kV or greater than +10 kV, although the effect of suppressing the generation of the raised portions is enhanced, there are problems such as attracting foreign matter, poor peeling due to incomplete static elimination, and adverse effects on peripheral devices due to atmospheric discharge. When it is greater than -0.5 kV and less than +0.5 kV, the adhesion is weak, and there is a problem that voids are generated by the impact when the laser beam is irradiated.

[0028] As shown in Fig. 2(c), after charging the static electricity, the raw material laminate RMB with double-sided base materials is cut using the laser beam 41, and the optical film laminate F1 is formed. The cutting by the laser beam 41 is performed here by irradiating the laser beam 41 from the side of the base film BF1 of the raw material laminate RMB with double-sided base materials, but it is not limited thereto, and it can also be performed from the side of the base film BF2. The intensity of the laser beam 41 is preferably set so as to reach a depth at which the surface protection film PF, the polarizing film POL, and the release liner RL are cut, but the base film BF1 or BF2 on the side opposite to the light source of the laser beam 41 is not cut.

[0029] As described above, when the required shape of the optical film laminate F1 is rectangular, the cutting by the laser beam 41 is performed linearly, but when the shape of the optical film laminate F1 is an arbitrary shape, it may be performed curvilinearly.

[0030] Next, as shown in FIG. 2(d), after cutting with the laser beam 41, the electrostatic charge is removed from the raw material laminate RMB with double-sided substrates (42). By removing the electrostatic charge, the adhesion state between the raw material laminate RM and the substrate films BF1 and BF2 is released. On both sides of the cut portion of the substrate film BF1 by the laser beam 41, the substrate film BF1 may be melted by the heat generated during cutting and solidify by swelling on the surface, thereby forming the raised portions 12. If there are portions V1 that protruded or portions V2 that were separated before charging, those portions may separate or protrude again. When removing the electrostatic charge, contrary to the case of charging, it is preferable to remove the electrostatic charge from the raw material laminate RMB with double-sided substrates while it is not in contact with anything.

[0031] Next, as shown in FIG. 2(e), the substrate film BF1 is peeled off from the surface of the optical film laminate F1. There are no raised portions at the end 11a of the cut portion of the optical film laminate F1 covered by the substrate film BF1. Finally, as shown in FIG. 2(f), the portion corresponding to the optical film laminate F1 is peeled off from the substrate film BF2, and an optical film laminate F1 having substantially no raised portions at the ends can be obtained. When non-adhesive materials are used as the substrate films BF1 and BF2, by removing the electrostatic charge, the release liner RL can be easily peeled off from the substrate films BF1 and BF2. On the other hand, when an adhesive material is used for either one or both of the substrate films BF1 and BF2, depending on the adhesive force, even when the electrostatic charge is removed, for example, when trying to peel the optical film laminate F1 from the substrate film BF1 or BF2, the release liner RL and the substrate film BF1 or BF2 may not be peeled off well, and the release liner RL may be peeled off between the release liner RL and the polarizing film POL, and there is a possibility that the release liner RL remains on the substrate film BF1 or BF2. Therefore, when using the adhesive substrate films BF1 and / or BF2, it is preferable that the adhesive force is smaller than the adhesive force of the release liner RL and / or the surface protective film.

[0032] (Apparatus for manufacturing an optical film laminate having no raised portions) [First Embodiment] FIG. 3 is a conceptual diagram of an apparatus 60 for manufacturing an optical film laminate substantially without a raised portion according to the first embodiment. The apparatus 60 is a sheet-web type apparatus that laminates web-like base films BF1 and BF2 on a sheet-like raw material laminate RM to form a raw material laminate RMB with web-like double-sided bases, and charges the raw material laminate RMB with double-sided bases and performs cutting with a laser beam.

[0033] The apparatus 60 includes, for example, a transport device 61 that takes out the sheet-like raw material laminate RM from a stocker and transports it to a laminating device 62 for the base films BF1 and BF2. As the transport device 61, an adsorption pickup device, a transport roller, etc., well-known to those skilled in the art can be appropriately used. In the apparatus 60, a plurality of sheet-like raw material laminates RM are continuously laminated in the length direction between the web-like base films BF1 and BF2 to form a raw material laminate RMB with web-like double-sided bases. For this reason, in the apparatus 60, the web-like base films BF1 and BF2 respectively fed out from the rolls BFR1 and BFR2 of the base film are configured to be transported to a laminating device 62 that laminates the raw material laminate RM and the base films BF1 and BF2.

[0034] In the laminating device 62, by passing the sheet-like raw material laminate RM and the web-like base films BF1 and BF2 between a pair of laminating rollers 62a, a web-like raw material laminate RMB with a sheet-like raw material laminate RM sandwiched between the web-like base films BF1 and BF2 can be formed. As the laminating roller 62a, a laminating roller for bonding two resin films via an adhesive, well-known to those skilled in the art, can be appropriately used.

[0035] The apparatus 60 includes a charging device 63 on the downstream side of the laminating apparatus 62. The charging device 63 charges the raw material laminate RMB with both-sided substrates electrostatically, so that the raw material laminate RM and the substrate films BF1 and BF2 can be adhered to each other by the static electricity. As the charging device 63, a charging device well-known to those skilled in the art can be appropriately used. For example, JPK-3 manufactured by Kasuga Electric Co., Ltd. can be used. In FIG. 3, the charging device 63 is disposed above on the downstream side of the laminating apparatus 62. Therefore, in the apparatus 60, by charging the raw material laminate RMB with both-sided substrates electrostatically from the side of the substrate film BF1, the raw material laminate RM and the substrate films BF1 and BF2 are adhered to each other by the static electricity. However, the position of the charging device 63 is not limited to this, and the charging device 63 may be disposed near the substrate film BF1 or BF2 on the upstream side of the laminating apparatus 62. In this case, before being laminated on the raw material laminate RM, the substrate film BF1 or BF2 is charged electrostatically, and when both are laminated by the laminating apparatus 62, the raw material laminate RM and the substrate films BF1 and BF2 will be adhered to each other. Alternatively, the charging device 63 may be disposed near the raw material laminate RM on the upstream side of the laminating apparatus 62. In this case, before being laminated, the raw material laminate RM is charged electrostatically, and when the substrate film BF1 or BF2 is laminated by the laminating apparatus 62, these and the raw material laminate RM will be adhered to each other. Alternatively, the charging device 63 may be disposed at a plurality of locations. For example, the charging device may be disposed on each of the upstream side and the downstream side of the laminating apparatus 62, or may be disposed on both the BF1 side and the BF2 side of the substrate film on the downstream side of the laminating apparatus 62.

[0036] The charged web-shaped raw material laminate RMB with both-sided substrates is conveyed through above the pedestal 65 by a conveying device 64 well-known to those skilled in the art. As the pedestal 65, one well-known to those skilled in the art can be appropriately used, but it is preferably a suction pedestal so that the raw material laminate RMB with both-sided substrates disposed thereon does not move during laser cutting.

[0037] The raw material laminate RMB with a double-sided substrate stops at one end on the pedestal 65 and is cut by the laser beam of the laser cutting device 66. The laser cutting device 66 can have, for example, a laser beam generation unit that generates a laser beam and irradiates the raw material laminate RMB with a double-sided substrate disposed on the pedestal 65, and a moving unit that moves the laser beam generation unit so as to cut the raw material laminate RMB with a double-sided substrate into an arbitrary shape. The laser cutting device 66 can appropriately use a device well-known to those skilled in the art for cutting a resin film.

[0038] The intensity of the laser beam is preferably set so as to reach a depth at which the base film BF1, the surface protection film PF, the polarizing film POL, and the release liner RL included in the raw material laminate RMB with a double-sided substrate are cut, but the base film BF2 is not cut. By the laser cutting device 66, the raw material laminate RM included in the raw material laminate RMB with a double-sided substrate is cut to form a plurality of optical film laminates F1 having an arbitrary shape between the base films BF1 and BF2. At this point, the base film BF1 cut in the same shape as the optical film laminate F1 is adhered to the surface protection film PF of the optical film laminate F1.

[0039] The raw material laminate RMB with a double-sided substrate after cutting is neutralized by the neutralizing device 67. The neutralizing device 67 is a device for removing static electricity from the charged raw material laminate RMB with a double-sided substrate. The neutralizing device 67 can appropriately use a neutralizing device well-known to those skilled in the art. For example, as the neutralizing device 67, JPK-3 manufactured by Kasuga Electric Co., Ltd. can be used.

[0040] In the raw material laminate RMB with double-sided substrates including the optical film laminate F1 from which static electricity has been removed by the static eliminator 67, the adhesion between the raw material laminate RM and the optical film laminate F1 and the base films BF1 and BF2 has been released, and the optical film laminate F1 can be easily peeled off from the base films BF1 and BF2. The apparatus 60 includes a peeling device 68 downstream of the static eliminator 67 for peeling the optical film laminate F1 from the base films BF1 and BF2.

[0041] The peeling device 68 has a pickup device 68a well-known to those skilled in the art for removing the base film BF1 laminated on the surface protection film PF side. Since the adhesion between the base film BF1 and the underlying surface protection film PF has been released by static elimination, the base film BF1 can be easily picked up. The peeling device 68 has a peeling roller (or peeling bar) 68b downstream of the pickup device 68a, and the remaining base film BF1 (with holes formed in the same shape as the optical film laminate F1) is pulled in a direction away from the conveyance direction of the raw material laminate RMB with double-sided substrates (upward in FIG. 3) via the peeling roller 68b. Accordingly, the remaining base film BF1 is peeled off from the optical film laminate F1 and wound up.

[0042] Further downstream of the peeling roller (or peeling bar) 68b, another peeling roller (or peeling bar) 68c is provided, and the base film BF2 on the peeling liner RL side is pulled in a direction away from the conveyance direction of the raw material laminate RMB with double-sided substrates (downward in FIG. 3) via the peeling roller 68c. Accordingly, the base film BF2 is peeled off from the optical film laminate F1 and wound up.

[0043] Since the remaining portion RMR of the raw material laminate from which the optical film laminate F1 has been cut is released from the base film BF2 by static elimination, when the base film BF2 is wound up, it separates from the base film BF2 and is recovered, for example, by simply dropping it. On the other hand, the optical film laminate F1 is sent out from the peeling device 68 by the peeling rollers 68b and 68c without changing its conveyance direction and is taken out by a conveyance device 69 well-known to those skilled in the art. In this way, an optical film laminate F1 having one or more arbitrary shapes can be obtained.

[0044] [Second Embodiment] FIG. 4 is a conceptual diagram of an apparatus 70 for manufacturing an optical film laminate substantially without raised portions according to the second embodiment. The apparatus 70 laminates web-like base films BF1 and BF2 on a web-like raw material laminate RM to form a web-like raw material laminate RMB with both-sided base materials, and shows a web-web type apparatus that charges the raw material laminate RMB with both-sided base materials and performs cutting with a laser beam. In the following, mainly, the configuration different from that of the apparatus 60 of the first embodiment will be described.

[0045] In the apparatus 60 of the first embodiment, a plurality of sheet-like raw material laminates RM are continuously laminated between web-like base films BF1 and BF2 to form a web-like raw material laminate RMB with both-sided base materials. In contrast, in the apparatus 70, web-like base films BF1 and BF2 are laminated on both sides of a web-like raw material laminate RM to form a web-like raw material laminate RMB with both-sided base materials. For this reason, in the apparatus 70, the web-like raw material laminate RM fed out from the roll RMR of the raw material laminate is configured to be conveyed to a laminating device 72 that laminates the raw material laminate RM with the base films BF1 and BF2.

[0046] In the laminating device 72, by passing the web-like raw material laminate RM and the web-like base films BF1 and BF2 between a pair of laminating rolls 72a, a web-like raw material laminate RMB with the web-like raw material laminate RM sandwiched between the web-like base films BF1 and BF2 can be formed.

[0047] The apparatus 70 includes a charging device 73 on the downstream side of the laminating device 72. The charging device 73 charges the raw material laminate RMB with both-sided substrates electrostatically, so that the raw material laminate RM and the substrate films BF1 and BF2 can be adhered to each other by static electricity. The position of the charging device 73 is not limited to this, which is the same as in the case of the apparatus 60, and one or more charging devices 73 can be appropriately arranged at any necessary location.

[0048] The web-shaped raw material laminate RMB in a charged state is conveyed by a conveying device 74 and cut with laser light on a pedestal 75. The cut raw material laminate RMB with both-sided substrates is then discharged by a discharging device 77. The conveying device 74, the pedestal 75, the laser cutting device 76, and the discharging device 77, and their functions can be the same as those of the apparatus 60.

[0049] In the raw material laminate RMB including the optical film laminate F1 from which static electricity has been removed by the discharging device 77, the adhesion state between the raw material laminate RM and the optical film laminate F1 and the substrate films BF1 and BF2 is released, and the optical film laminate F1 and the substrate films BF1 and BF2 can be easily peeled off. Also in the apparatus 70, in order to peel the optical film laminate F1 and the substrate films BF1 and BF2, a peeling device 78 is provided downstream of the discharging device 77.

[0050] The peeling device 78 can be configured to have a pickup device for removing the substrate film BF1 cut in the same shape as the optical film laminate F1, similar to the peeling device 68. Here, however, another configuration will be described. Note that the configuration described below can also be adopted by the peeling device 68.

[0051] In the peeling device 78, using the tape TP, the cut base film BF1 and the remaining part of the base film BF1 are joined together, and these are peeled from the optical film laminate F1 together with the tape TP. The tape TP is fed out from the tape roll TPR with its adhesive surface facing the base film BF1 side. The fed-out tape TP is bonded to the base film BF1 of the raw material laminate RMB with both-sided base materials from which static electricity has been removed by the static eliminator 77 at the bonding part 78a. The position where the tape TP is bonded is not limited as long as the cut base film BF1 and the remaining part of the base film BF1 can be joined together. In the example of FIG. 4, three cut base films BF1 are arranged in the width direction of the raw material laminate RMB with both-sided base materials, and in order to join them to the remaining part of the base film BF1, three narrow tapes TP are shown to be fed out from the roll TPR.

[0052] Downstream of the bonding part 78a, there is a peeling roller (or peeling bar) 78b, and the base film BF1 joined by the tape TP is pulled in a direction away from the conveyance direction of the raw material laminate RMB with both-sided base materials (upward in FIG. 4) via the peeling roller 78b. Therefore, the base film BF1 joined by the tape TP is peeled from the optical film laminate F1 and wound around a winding roller.

[0053] Downstream of the peeling roller 78b, another peeling roller (or peeling bar) 78c is provided. The remaining part RMR of the web-shaped raw material laminate RM from which the optical film laminate F1 has been cut is in a state where the adhesion to the base film BF2 has been released by being static-eliminated, and is pulled in a direction away from the conveyance direction (upward in FIG. 4) via the peeling roller 78c and wound up. Further downstream of the peeling roller (or peeling bar) 78c, yet another peeling roller (or peeling bar) 78d is provided, and the base film BF2 on the peeling liner RL side is pulled in a direction away from the conveyance direction (downward in FIG. 4) via the peeling roller 78d. Therefore, the base film BF2 is peeled from the optical film laminate F1 and wound up.

[0054] The optical film laminate F1 cut out from the web-like raw material laminate RM passes through the peeling roller 78d without changing the conveyance direction, is sent out from the peeling device 78, and is taken out by a conveyance device or the like well-known to those skilled in the art. In this way, an optical film laminate F1 having one or a plurality of arbitrary shapes can be obtained.

Examples

[0055] Hereinafter, examples and comparative examples of the present invention will be described. Table 1 shows the examples and comparative examples of the present invention. In the examples, an optical laminate in which a surface protection film was laminated on one surface of a sheet-like optical functional film (optical functional layer) and a release liner was laminated on the other surface was prepared, and a sheet-like base material film was laminated on both the surface of the surface protection film and the surface of the release liner. This was nipped with a lamination roller well-known to those skilled in the art to form a raw material laminate with a double-sided base material, and static electricity was charged after nipping.

[0056] Next, the amount of static electricity on the surface of the charged raw material laminate with a double-sided base material was measured, and the raw material laminate with a double-sided base material was cut with a laser beam from the surface protection film side so that the base material film on the release liner side was not cut. After cutting, the static electricity was removed, and the height of the raised portion at the end of the cut portion was measured for the optical film laminate obtained by peeling the base material films on both sides.

[0057] On the other hand, in Comparative Example 1, a sheet-like base material film was laminated on the surface of the release liner side of the same optical laminate as in the example, and this was nipped with a lamination roller well-known to those skilled in the art to form a raw material laminate with a single-sided base material, and static electricity was charged. The raw material laminate with a single-sided base material was cut with a laser beam from the side opposite to the side on which the base material film was laminated (surface protection film side) leaving the base material film. After cutting, the static electricity was removed, and the height of the raised portion at the end of the cut portion was measured for the optical film laminate obtained by peeling the base material film. Further, in Comparative Example 2, the height of the raised portion of the optical film laminate obtained by cutting the raw material laminate with a double-sided base material similar to that in the example with a laser beam without charging and removing the base material film was measured.

[0058] As the optical laminate, a polarizing film with retardation for mobile use (GRT1794XH1UHC) manufactured by Nitto Denko Corporation was used, and the thickness was 178 μm. As the base film, a PET film with a thickness of 25 μm was used. As the device for charging and discharging static electricity, JPK-3 manufactured by Kasuga Electric Co., Ltd. was used. The laser beam used for cutting was a CO2 laser with a wavelength of 9.4 μm. As the laser beam generator, TLSM301 manufactured by Takei Electric Industry Co., Ltd. was used, and cutting was performed by focusing on the surface of the polarizing film at an output of 35 W, a frequency of 15 kHz, and a feed rate of 500 mm / sec.

[0059] The height of the raised portion was measured as follows. For each of the examples and comparative examples, three optical film laminates were produced by the above method, and a cross-sectional profile was obtained from an image of a part of the end portion at the cut portion of each optical film laminate using a laser microscope (manufactured by Keyence Corporation). The amount of protrusion at 50 locations was measured from each cross-sectional profile, and the average value of the 50 amounts of protrusion was calculated. For each of the examples and comparative examples, the average value of the amounts of protrusion of the three optical film laminates calculated in this way was further averaged, and this was taken as the height of the raised portion of the optical film laminate.

[0060]

Table 1

[0061] In both Example 1 and Example 2, the amount of static electricity charged was -1.0 kV to -4.0 kV. However, in Example 1, charging was performed from the surface protection film side of the raw material laminate with double-sided substrates, and in Example 2, charging was performed from both sides of the raw material laminate with double-sided substrates. In any of the examples, an optical film laminate substantially without raised portions was obtained.

[0062] Example 3 is the case where the static electricity amount is -11.0 kV to -12.0 kV, and the charging occurs after the nip. When charging with such a small static electricity amount (that is, the adhesive force due to static electricity is strong), although no bulges substantially occurred on the adhesion surface, there is a risk of problems such as attracting foreign substances, poor peeling due to incomplete discharge, and adverse effects on peripheral devices due to atmospheric discharge.

[0063] In Comparative Example 1, the charged static electricity amount was -1.0 kV to -4.0 kV, which was the same level of static electricity amount as in Example 1 and Example 2. However, a 13-μm bulge occurred at the cut portion on the surface protection film side where the base material film was not laminated. Therefore, an optical film laminate without substantially any bulge at the cut portion could not be obtained. Comparative Example 2 is the result when cutting the raw material laminate with both-sided base materials with a laser beam without charging it, and it was slightly charged due to friction or the like. In Comparative Example 2, large bulges were generated on both surfaces despite the presence of the base material film.

Explanation of Symbols

[0064] F1 Optical film laminate without bulges 11 One side 11a End 11b Edge 13 The other side 13a End 13b Edge 15 End face BF1, BF2 Base material film BFR1, BFR2 Rolls of base material film RM Raw material laminate RMB Raw material laminate with both-sided base materials RMR Remainder of raw material laminate TP Release tape 40 Charging device 41 Laser beam 42 Discharging device 60 Sheet-web type manufacturing device 61, 64, 69 Conveying device 62 Laminating device 62a Laminating roller 63 Charging device 65 Base 66 Laser cutting device 67 Static eliminator 68 Peeling device 68a Pickup device 68b, 68c Peeling roller or peeling bar 70 Web - web type manufacturing device 72 Laminating device 72a Laminating roller 73 Charging device 74 Conveying device 75 Base 76 Laser cutting device 77 Static eliminator 78 Peeling device 78a Bonding part 78b, 78c, 78d Peeling roller or peeling bar

Claims

1. A step of conveying a raw material laminate in which a first resin film is laminated on one surface of an optical functional layer including one or more films, and a second resin film is laminated on the other surface; A step of laminating a first base material on the first resin film of the raw material laminate and laminating a second base material on the second resin film to obtain a raw material laminate with base materials on both sides; A step of bringing the first base material, the second base material, and the raw material laminate into close contact with each other by charging static electricity to the raw material laminate, the first base material, the second base material, or the raw material laminate with base materials on both sides, or a plurality of these; A step of forming a cut surface with an arbitrary shape on the raw material laminate using laser light; A step of removing static electricity from the raw material laminate with base materials on both sides; A step of peeling the first base material and the second base material from one or more optical film laminates having the cut surface with an arbitrary shape A method for manufacturing an optical film laminate, comprising:

2. The method according to claim 1, wherein the step of bringing into close contact includes charging static electricity to both surfaces of the raw material laminate, both the first base material and the second base material, both surfaces of the raw material laminate with base materials on both sides, or a plurality of these.

3. The method according to claim 1, wherein one of the first resin film and the second resin film is a surface protection film, and the other of the first resin film and the second resin film is a release liner.

4. The method according to claim 1, wherein the raw material laminate is a web-like laminate.

5. The method according to claim 1, wherein the first base material and the second base material are web-like base materials.

6. The method according to claim 1, wherein the first base material and the second base material are non-adhesive base materials.

7. The method according to claim 1, wherein the first base material and the second base material are made of the same material.

8. The amount of static electricity to be charged is an amount of static electricity at which the first base material, the second base material, and the raw material laminate do not peel off when the cut surface is formed by the laser light. The manufacturing method according to claim 1.

9. The method according to claim 8, wherein the amount of static electricity is -10 kV or more and -0.5 kV or less, or 0.5 kV or more and 10 kV or less.

10. The method according to claim 9, wherein the amount of static electricity is -4.0 kV or more and -0.5 kV or less.

11. In the step of obtaining the raw material laminate with both-sided substrates, one or both of the first substrate and the second substrate are those obtained by reusing the substrates peeled off in the step of peeling one or more of the optical film laminates having the cut surfaces of arbitrary shapes from the first substrate and the second substrate. The manufacturing method according to claim 1.

12. A conveying device configured to convey a raw material laminate in which a first resin film is laminated on one surface of an optical functional layer including one or more films and a second resin film is laminated on the other surface; A laminating device configured to laminate a first substrate on the first resin film of the raw material laminate and laminate a second substrate on the second resin film to produce a raw material laminate with both-sided substrates; A charging device configured to charge static electricity to the raw material laminate, the first substrate, the second substrate, or the raw material laminate with both-sided substrates, or a plurality of these, in order to bring the first substrate and the second substrate into close contact with the raw material laminate; A laser cutting device configured to cut the raw material laminate of the raw material laminate with both-sided substrates to form one or more optical film laminates of arbitrary shapes; A static eliminator configured to remove static electricity from the raw material laminate with both-sided substrates; A peeling device configured to peel the first substrate and the second substrate from one or more optical film laminates of arbitrary shapes An apparatus comprising.

Images