Optical film laminate having bulge part, and manufacturing method and manufacturing apparatus for the same

Abstract

To provide an optical film laminate in which a bulge at an edge of a cut portion cut by a laser beam is suppressed.SOLUTION: An optical film laminate in an arbitrary shape includes: a first resin film laminated on one side of an optical functional layer including one or multiple films; and a second resin film laminated on the other side thereof. The optical film laminate has a first bulge part on an edge of the first resin film. The optical film laminate has a second bulge part on an edge of the second resin film located corresponding to the edge of the first resin film. The first bulge part and the second bulge part are different in height.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical film laminate and a manufacturing technique thereof, and more specifically, to an optical film laminate in which a bulge that may occur at the end of a cut portion, generated by cutting with a laser beam in a state where an optical film laminate before cutting and a base film are adhered by static electricity, is suppressed, and a manufacturing method and a manufacturing apparatus therefor.

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 adopted according to the use and shape of the final product.

[0003] For example, in the manufacturing process of an optical film laminate used for smartphones, 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 and 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 process, a sheet-shaped laminate may be used instead of the long web-shaped laminate, 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, when 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 leads 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-like or sheet-like 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 in image recognition. As a result, there is a risk of problems in packaging at the time of shipment, alignment for bonding to a liquid crystal cell or an organic EL cell in a subsequent process, or problems when taking out each optical film laminate one by one from a plurality of stacked optical film laminates.

[0006] Also, for example, when peeling the 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 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 even when the peeling tape is pulled up.

[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 an optical film laminate in which bulges at the ends of the cut portions cut by laser light are suppressed. Another object of the present invention is to provide a method and an apparatus for manufacturing an optical film laminate in which the generation of bulges at the ends is suppressed when cut by laser light.

Means for Solving the Problems

[0010] The inventors of the present invention laminated a base film (carrier) on a laminate (raw material laminate) before being cut by laser light, charged and adhered both of them using static electricity, and then cut them by laser light. As a result, it was found that an optical film laminate in which no bulge is generated at the end of the surface on which the base film is laminated, or even if a bulge is generated, its size is suppressed can be obtained.

[0011] In one aspect, the present invention provides an optical film laminate of any shape 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. The optical film laminate has a first bulge at the end of the first resin film. Further, the optical film laminate has a second bulge at the end of the second resin film at a position corresponding to the end of the first resin film. The height of the first bulge and the height of the second bulge are different.

[0012] In another 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 base material is laminated on either the first resin film or the second resin film of the raw material laminate to obtain a raw material laminate with a base material. Next, by charging static electricity to the raw material laminate, the base material, or the raw material laminate with a base material, or a plurality of these, the base material and the raw material laminate are adhered to each other, and then, a cutting surface of any shape is formed on the raw material laminate with a base material using laser light. Static electricity is removed from the raw material laminate with a base material, and one or more optical film laminates having a cutting surface of any shape are peeled off from the base material.

[0013] In yet 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 base material on either the first resin film or the second resin film of the raw material laminate to produce a raw material laminate with a base material, a charging device for charging static electricity to the raw material laminate, the base material, or the raw material laminate with a base material, or a plurality of these to adhere the base material and the raw material laminate to each other, a laser cutting device for cutting the raw material laminate of the raw material laminate with a base material to form one or more optical film laminates of any shape, a static eliminator for removing static electricity from the raw material laminate with a base material, and a peeling device for peeling one or more optical film laminates of any shape from the base material.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0016] (Configuration of the optical film laminate having a raised portion) Figure 1 shows a schematic cross-sectional view of an optical film laminate having a raised portion according to an embodiment of the present invention. Fig. 1(a) is a schematic cross-sectional view of an optical film laminate F1 having a raised portion on one surface 11 and no raised portion on the other surface 13. Further, Fig. 1(c) is a schematic cross-sectional view showing a state in which the raw material laminate RM is cut by laser light. The optical film laminate F1 can be manufactured by the manufacturing method described later according to the present invention. For example, a base film BF is laminated on one surface (the lower surface of the laminate in Fig. 1(c)) of a web-shaped raw material laminate RM, and the raw material laminate RM and the base film BF are adhered to each other by charging static electricity, and obtained by cutting using laser light. Fig. 1(a) shows a state in which the cut portion is viewed from the side (a state viewed from the lower left obliquely in Fig. 1(c)). The portions of each reference numeral in Fig. 1(c) correspond to the portions of the reference numerals in Fig. 1(a) and Fig. 1(b).

[0017] The optical film laminate F1 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. 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 to this. The optical film laminate may have, for example, 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 surface of the optical functional layer and surface protection films PF are laminated on multiple surfaces. 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 lightly peeling liner is laminated on one surface of an OCA and a heavily peeling liner is laminated on the other surface, or a laminate in which a lightly peeling liner is laminated on one surface of a PET film and a heavily peeling liner is laminated on the other surface.

[0018] The optical film laminate F1 can be cut out as a laminate having an arbitrary shape from, for example, a web-shaped raw material laminate RM using laser light. The arbitrary shape includes not only shapes such as a square, a circle, and an ellipse, but also irregular shapes. The irregular laminate includes, for example, a shape having a notch or a recess (so-called notch) in any one of the sides of a square shape, a pillow shape used for an automobile instrument panel, a shape in which holes such as a circle or a square are provided in a part of a square film, and the like. For example, in the case of a laminate having a notch or a recess (so-called notch) in any one of the sides of a square shape, the cutting surface by laser light is formed not only on each side but also inside the notch or the recess.

[0019] The optical film laminate F1 has a raised portion 12 at the end 11a of the surface 11 on the surface protection film PF side, and does not have a raised portion at the end 13a of the surface 13 of the release liner RL. In Fig. 1(a), the optical film laminate F1 has a raised portion 12 only on the surface 11 on the surface protection film PF side, but is not limited thereto, and may have a raised portion only on the surface 13 on the release liner RL side. Here, 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.

[0020] The optical film laminate F1 is obtained by cutting the raw material laminate RM. The raw material laminate RM can be a laminate in which a resin film similar to the optical film laminate F1 is laminated. The raised portion 12 is formed, for example, by the heat generated when cutting the web-shaped raw material laminate RM using laser light, melting the resin film (surface protection film) laminated on the outermost surface of the portion cut by the laser light, swelling, and solidifying. Also, fine dust (fume) in which the vapor of the raw material laminate RM generated during melting aggregates may be generated and scattered around the cutting surface.

[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 BF is laminated on the surface 13 on the release liner RL side, and the raw material laminate RMB with a base is charged with static electricity. Since the surface 13 of the release liner RL of the raw material laminate RM and the base film BF are in close contact due to static electricity, when the raw material laminate RM is cut in this state, normally, no raised portions are formed on the surface 13. Further, no fumes are generated on the surface 13. Here, close contact means a state in which no air layer or air pocket exists between the two films, and no such air layer or air pocket is formed even when being conveyed. If the surface 13 of the release liner RL and the base film BF are in complete close contact, there is no space where physical raised portions can occur, and since the heat during cutting with a laser beam is less likely to conduct to the base film BF and the surface temperature is less likely to rise, no raised portions are formed on the surface 13.

[0022] The raised portion 12 has a predetermined height. The height is the distance from the surface 11 to the top of the raised portion 12. The height of the raised portion 12 is preferably lower than 12% of the thickness of the optical film laminate F1 in the portion where the raised portion 12 does not exist, more preferably lower than 8%, and even more preferably lower than 5%. The height of the raised portion 12 is preferably lower than 20 μm, more preferably lower than 14 μm, and even more preferably lower than 8 μm. If the height of the raised portion 12 is lower than 12% of the thickness of the optical film laminate F1, when a plurality of optical film laminates F1 are stacked with their ends aligned, the phenomenon that each optical film laminate F1 is displaced by the raised portion 12 does not occur, and no problems with image recognition occur. Further, if the raised portion 12 is lower than 12% of the thickness of the optical film laminate F1, it does not affect the peeling of the surface protection film PF by the peeling tape. The raised portion 12 tends to become higher as the intensity of the laser beam for cutting becomes stronger.

[0023] The width of the raised portion 12, that is, the length in the inner direction (the left - right direction in FIG. 1(a)) from the edge 11b of the optical film laminate F1, is preferably less than 100 μm, and more preferably less than 80 μm. When the width of the raised portion 12 is 100 μm or more, during alignment and side length measurement for bonding the optical film laminate F1 to a liquid crystal cell or the like in a later process, the raised portion may be recognized and the line width of the captured image may become thick. Depending on the set threshold value, displacement of the reading position may occur, leading to problems such as a decrease in bonding accuracy and reading errors.

[0024] The optical film laminate F1 has an end face 15 which is a cut surface cut by a laser beam. 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. Due to the characteristics of the formation of the cut surface by the laser beam, the end face 15 is typically an inclined surface, but is not limited thereto, and may be a surface perpendicular to the surfaces 11 and 13. In FIG. 1(a), the end face 15 is represented as a plane, 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 plane and a curved surface.

[0025] FIG. 1(b) is a schematic cross - sectional view of an optical film laminate F2 having raised portions on both the one surface 21 and the other surface 23. Similar to F1, the optical film laminate F2 is also manufactured by the manufacturing method described later according to the present invention. FIG. 1(b) shows a state where the cut portion is viewed from the side (lower left obliquely in FIG. 1(c)).

[0026] The optical film laminate F2 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. The optical film laminate F2 has a raised portion 22 at an end portion 21a of a surface 21 on the surface protection film PF side, and a raised portion 24 at an end portion 23a of a surface 23 on the release liner RL side. The raised portion 22 is formed, for example, by heat generated when cutting a web-shaped raw material laminate RM using laser light, causing the resin film (surface protection film, release liner) laminated on the outermost surface of the portion cut by the laser light to melt, swell on the surface, and solidify. Also, fine dust (fume) formed by the aggregation of the vapor of the raw material laminate RM generated during melting may be generated and scattered around the cut surface.

[0027] When manufacturing the optical film laminate F2, similar to the case of manufacturing the optical film laminate F1, before cutting the raw material laminate RM with laser light, a base film BF is laminated on the surface 23 on the release liner RL side to charge static electricity. As described in the explanation of the optical film laminate F1, if the surface 23 of the release liner RL and the base film BF are firmly adhered, no raised portion will occur. However, for example, due to a decrease in charge and / or non-uniformity, etc., there may be a case where the adhesion is partially insufficient. When a slight air layer is formed at this portion due to the impact during cutting with laser light or the non-uniformity of the conveyance tension of the raw material laminate RMB with a base, a raised portion may occur. In the optical film laminate F2, the reason why the raised portion 24 occurs on the surface 23 on the release liner RL side despite the lamination of the base film BF is due to such reasons.

[0028] In the optical film laminate F2, the end portion 23a where the raised portion 24 exists is at a position corresponding to the end portion 21a where the raised portion 22 exists. Specifically, the end portion 21a is at a position adjacent to the laser light cut portion of the surface 21 of the surface protection film PF in the optical film laminate F2, and the end portion 23a is at a position adjacent to the laser light cut portion of the surface 23 of the release liner RL.

[0029] In the optical film laminate F2, the height of the raised portion 24 is lower than that of the raised portion 22. Preferably, the sum of the height of the raised portion 22 (the distance from the surface 21 to the top of the raised portion 22) and the height of the raised portion 24 (the distance from the surface 23 to the top of the raised portion 24) is preferably lower than 20% of the thickness of the optical film laminate F2 in the portion where the raised portions 22 and 24 do not exist, more preferably lower than 15%, and even more preferably lower than 10%. The sum of the height of the raised portion 22 and the height of the raised portion 24 is preferably 35 μm or less, more preferably lower than 30 μm, and even more preferably 15 μm or less. The height of the raised portion 24 is preferably 1 μm or less. Most preferably, the height of the raised portion 24 is zero. In this case, the optical film laminate F2 corresponds to the optical film laminate F1.

[0030] Similar to the optical film laminate F1, the optical film laminate F2 has an end face 25, which is a cut surface formed by laser light, between the edge 21b of the surface 21 and the edge 23b of the surface 23. Similar to the end face 15, the end face 25 is typically an inclined surface, but is not limited thereto, and may be a surface perpendicular to the surfaces 21 and 23. Further, although the end face 25 is shown as a plane in FIG. 1(b), it is not limited thereto, and the end face 25 may be a curved surface or a combination of a plane and a curved surface.

[0031] (Process for manufacturing the optical film laminate according to the present invention) FIG. 2 is a conceptual diagram of a process for manufacturing the optical film laminate F1 or F2 having raised portions. In FIG. 2(a), a base film BF is laminated on one surface of a raw material laminate RM to obtain a raw material laminate RMB with a base. 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 in a web form or a sheet form. Here, the base film BF is laminated on the surface 13R on the release liner RL side of the raw material laminate RM, but is not limited thereto, and may be laminated on the surface 11R on the surface protection film PF side.

[0032] As the base film BF, either a non-adhesive material without an adhesive layer or an adhesive material may be used. 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 BF used in the process of manufacturing the optical film laminate according to the present invention or to use waste materials used in other processes or products, and it is expected to reduce the amount of base film used and the manufacturing cost. 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.

[0033] On the other hand, when an adhesive material is used as the base film BF, the raw material laminate RM and the base film BF can be adhered more firmly, so it is possible to more effectively suppress the generation of ridges 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, if 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.

[0034] Next, as shown in FIG. 2(b), an electrostatic charge is applied to the raw material laminate with substrate RMB in which the raw material laminate RM and the base film BF are laminated (40). By applying the electrostatic charge, the opposing surfaces of the raw material laminate RM and the base film BF can be brought into close contact (FIG. 2(c)). As shown in FIGS. 2(b) and 2(c), for example, even if there is a portion V where the raw material laminate RM is separated from the surface of the base film BF, by applying an electrostatic charge to bring the raw material laminate RM into close contact with the base film BF, the separated portion V can be eliminated. The application of the electrostatic charge is not limited to being performed on the raw material laminate with substrate RMB, and may be performed on the raw material laminate RM before being laminated with the base film BF, or may be performed on the base film BF before being laminated with the raw material laminate RM. Although not shown, when applying an electrostatic charge to the raw material laminate with substrate RMB, the charged portion of the raw material laminate with substrate RMB 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 contacting portion for charging, which is preferable.

[0035] It is preferable that the electrostatic charge is uniformly applied to the entire surfaces of the raw material laminate RM and the base film BF. The amount of electrostatic charge to be applied is such that the base film BF 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 electrostatic charge 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 electrostatic charge is less than -10 kV or greater than +10 kV, although the effect of suppressing the generation of raised portions is enhanced, there are problems such as attracting foreign matter, incomplete discharge and peeling failure, 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.

[0036] As shown in Fig. 2(c), after charging the static electricity, the raw material laminate RMB with a substrate is cut using the laser beam 41, and the optical film laminate F1 is formed. The cutting by the laser beam 41 is performed by irradiating the laser beam 41 from the side opposite to the substrate film BF of the raw material laminate RMB with a substrate (here, the side of the surface protection film (PF)). 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 substrate film BF is not cut.

[0037] As described above, the cutting by the laser beam 41 is performed linearly when the required shape of the optical film laminate F1 is rectangular, but may be performed curvilinearly when the shape of the optical film laminate F1 is an arbitrary shape. On both sides of the cutting portion by the laser beam 41, as shown in Fig. 2(d), the raw material laminate RM is melted by the heat generated during cutting and swells and solidifies on the surface, thereby forming the raised portion 12. The raised portion 12 is formed on a part or all of the end portion 11a of the surface protection film PF.

[0038] Next, as shown in Fig. 2(d), after cutting by the laser beam 41, the static electricity is removed from the raw material laminate RMB with a substrate (42). By removing the static electricity, the adhesion state between the raw material laminate RM and the substrate film BF is released. If there is a portion V that was separated before charging, that portion may be separated again. When removing the static electricity, contrary to the charging time, it is preferable to remove the static electricity from the raw material laminate RMB with a substrate in a state where it is not in contact with anything.

[0039] Finally, as shown in FIG. 2(e), a portion corresponding to the optical film laminate F1 of the raw material laminate RM is peeled off from the base film BF, and an optical film laminate F1 having the raised portions 12 can be obtained. When a non-adhesive material is used as the base film BF, the peeling liner RL and the base film BF can be easily peeled off by performing static elimination. On the other hand, when an adhesive material is used as the base film BF, depending on its adhesive force, even when static elimination is performed, when attempting to peel the optical film laminate F1 from the base film BF, the peeling liner RL and the base film BF may not be peeled off properly, and the peeling may occur between the peeling liner RL and the polarizing film POL, leaving the peeling liner RL on the base film BF. Therefore, when using an adhesive base film BF, it is preferable that the adhesive force of the base film BF is smaller than the adhesive force of the peeling liner RL.

[0040] (Apparatus for manufacturing an optical film laminate having raised portions) [First Embodiment] FIG. 3 is a conceptual diagram of an apparatus 50 for manufacturing an optical film laminate having raised portions according to the first embodiment. The apparatus 50 is a sheet-to-sheet type apparatus that laminates a sheet-like base film BF on a sheet-like raw material laminate RM to form a sheet-like raw material laminate with a base RMB, and charges the raw material laminate with a base RMB to perform cutting with a laser beam.

[0041] The apparatus 50 includes, for example, a transport device 51a that takes out a sheet-like raw material laminate RM from a stocker and transports it to a lamination device 52 for the base film BF, and a transport device 51b that similarly takes out a sheet-like base film BF from the stocker and transports it to the lamination device 52 for the raw material laminate RM. As the transport devices 51a and 51b, suction pickup devices and transport rollers well-known to those skilled in the art can be appropriately used.

[0042] The apparatus 50 includes a lamination device 52 and a charging device 53. In the laminating device 52, a raw material laminate RM and a base film BF are passed between a pair of laminating rollers 52a, whereby a raw material laminate RMB with a sheet-like base material can be formed. As the laminating roller 52a, a laminating roller well-known to those skilled in the art for bonding two resin films via an adhesive can be appropriately used.

[0043] The charging device 53 is a device for charging the raw material laminate RM with static electricity. As the charging device 53, 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 53 is disposed above the raw material laminate RM on the downstream side of the laminating device 52. Therefore, in the device 50, the raw material laminate RM and the base film BF are adhered by static electricity by charging static electricity from the raw material laminate RM side of the raw material laminate RMB with a base material obtained by laminating the raw material laminate RM and the base film BF. In order to ensure the most desirable adhesion force by charging, it is preferable to charge the raw material laminate RMB with a base material. However, the position of the charging device 53 is not limited to this, and the charging device 53 may be disposed on the side of the base film BF on the downstream side of the laminating device 52. Alternatively, it may be disposed near the base film BF on the upstream side of the laminating device 52. In this case, the base film BF is charged with static electricity before being laminated on the raw material laminate RM, and they will adhere when laminated by the laminating device 52. Alternatively, the charging device 53 may be disposed near the raw material laminate RM on the upstream side of the laminating device 52. In this case, the raw material laminate RM is charged with static electricity before being laminated, and they will adhere when laminated by the laminating device 52. Alternatively, the charging device 53 may be disposed at a plurality of the above-described disposal locations. For example, charging devices may be disposed on both the upstream side and the downstream side of the laminating device 52 so as to charge both the raw material laminate RM and the raw material laminate RMB with a base material.

[0044] The charged raw material laminate RMB with a substrate is conveyed onto a pedestal 55 for laser cutting by a conveying device 54 including an adsorption pickup device well-known to those skilled in the art. The pedestal 55 is preferably an adsorption pedestal so that the raw material laminate RMB with a substrate disposed thereon does not move during laser cutting. As the pedestal 55, those well-known to those skilled in the art can be appropriately used.

[0045] The device 50 includes a laser cutting device 56. The laser cutting device 56 can, for example, have a laser light generation unit that generates laser light and irradiates the raw material laminate RMB with a substrate disposed on the pedestal 55, and a moving unit that moves the laser light generation unit so as to cut the raw material laminate RMB with a substrate into an arbitrary shape. As the laser cutting device 56, those well-known to those skilled in the art and used for cutting resin films can be appropriately used.

[0046] As described above, the intensity of the laser light 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 included in the raw material laminate RMB with a substrate are cut, but the substrate film BF is not cut. By the laser cutting device 56, the raw material laminate RM included in the raw material laminate RMB with a substrate can be cut to form an optical film laminate F1 having an arbitrary shape on the substrate film BF. In this case, it is possible to form only one optical film laminate F1 from one raw material laminate RMB with a substrate, or to form a plurality of optical film laminates F1 from one raw material laminate RMB with a substrate.

[0047] The device 50 includes a static eliminator 57. The static eliminator 57 is a device for removing static electricity from the charged raw material laminate RMB with a substrate. As the static eliminator 57, those well-known to those skilled in the art can be appropriately used. For example, as the static eliminator 57, JPK-3 manufactured by Kasuga Electric Co., Ltd. can be used.

[0048] In the raw material laminate RMB with a substrate including the optical film laminate F1 from which static electricity has been removed by the static eliminator 57, the adhesion between the raw material laminate RMB with a substrate and between the optical film laminate F1 and the substrate film BF has been released, and the optical film laminate F1 can be easily peeled off from the substrate film BF. In the first embodiment, the optical film laminate F1 can be obtained by peeling off the sheet-like substrate film BF after static elimination.

[0049] Therefore, the apparatus 50 includes a peeling device 58 that attaches the tape TP to the substrate film BF to connect the sheet-like substrate film BF and peels the substrate film BF together with the tape TP from the optical film laminate F1. The tape TP is fed out from the tape roll TPR with its adhesive surface facing the substrate film BF side. The fed-out tape TP is bonded at the bonding portion 58a to the substrate film BF of the raw material laminate RMB with a substrate including the optical film laminate F1 that has been sent out from the pedestal 55 and from which static electricity has been removed. The position where the tape TP is bonded is not limited, but may be at least a part of the substrate film BF, for example, only both ends. In FIG. 3, two narrow tapes TP are shown as being fed out from the roll TPR.

[0050] Downstream of the bonding portion 58a between the raw material laminate RMB with a substrate and the tape TP, the substrate film BF bonded with the tape TP is pulled in a direction away from the conveyance direction of the raw material laminate RMB with a substrate via the peeling roller (or peeling bar) 58b. Therefore, while the substrate film BF connected by the tape TP is wound up, the optical film laminate F1 peeled off from the substrate film BF is sent out from the peeling device 58 without changing its conveyance direction by the peeling roller 58b and is taken out by a conveyance device 59 well-known to those skilled in the art. In this way, one or more optical film laminates F1 having arbitrary shapes can be obtained. Next, the optical film laminate F1 is passed to subsequent processes, for example, an end face treatment process or a packaging process, by a conveyance device (not shown) including a pickup device well-known to those skilled in the art.

[0051] [Second Embodiment] FIG. 4 is a conceptual diagram of an apparatus 60 for manufacturing an optical film laminate having a raised portion according to the second embodiment. The apparatus 60 shows a sheet-web type apparatus that laminates a web-shaped base film BF on a sheet-shaped raw material laminate RM to form a raw material laminate RMB with a web-shaped base, and then charges the raw material laminate RMB with the web-shaped base and performs cutting with a laser beam. In the following, mainly, the configuration different from that of the apparatus 50 of the first embodiment will be described.

[0052] The apparatus 50 is configured such that a sheet-shaped raw material laminate RM is laminated on a sheet-shaped base film BF to form a sheet-shaped raw material laminate RMB with a base. On the other hand, in the apparatus 60, a plurality of sheet-shaped raw material laminates RM are continuously laminated on a web-shaped base film BF in its length direction to form a web-shaped raw material laminate RMB with a base. Therefore, in the apparatus 60, the web-shaped base film BF fed out from the roll BFR of the base film is configured to be conveyed to a laminating device 62 that laminates the raw material laminate RM and the base film BF. The conveying device 61 of the sheet-shaped raw material laminate RM and its function can be the same as those of the conveying device 51a of the apparatus 50.

[0053] In the laminating device 62, a web-shaped raw material laminate RMB with a base can be formed by passing a sheet-shaped raw material laminate RM and a web-shaped base film BF between a pair of laminating rollers 62a.

[0054] The apparatus 60 includes a charging device 63 on the downstream side of the laminating device 62. The charging device 63 charges the raw material laminate RMB with a base with static electricity after the sheet-shaped raw material laminate RM is laminated on the web-shaped base film BF, whereby the raw material laminate RM and the base film BF are adhered by static electricity. The position of the charging device 63 is not limited to this, and the charging device 63 may be arranged to charge the sheet-shaped raw material laminate RM or the web-shaped base film BF before being laminated on the upstream side of the laminating device 62.

[0055] The charged web-like raw material laminate RMB with a substrate is conveyed over the pedestal 65 by a conveying device 64 well-known to those skilled in the art. On the pedestal 65, the raw material laminate RMB with a substrate stops at one end and is cut by the laser beam of the laser cutting device 66. The pedestal 65 is preferably a suction pedestal so that the raw material laminate RMB with a substrate disposed thereon does not move during laser cutting. The raw material laminate RMB after cutting is discharged of static electricity by a static eliminator 67. The laser cutting device 66 and its functions can be the same as those of the laser cutting device 56 of the device 50, and the static eliminator 67 and its functions can also be the same as those of the static eliminator 57 of the device 50.

[0056] In the raw material laminate RMB including the optical film laminate F1 from which static electricity has been removed by the static eliminator 67, the adhesion state between the raw material laminate RM and the optical film laminate F1 and the web-like substrate film BF is released, and the optical film laminate F1 can be easily peeled off from the substrate film BF. In the device 60, in order to peel the optical film laminate F1 and the sheet-like substrate film BF, a peeling device 68 is provided downstream of the static eliminator 67.

[0057] The peeling device 68 has a peeling roller (or peeling bar) 68a, and the web-like substrate film BF is pulled in a direction away from the conveying direction of the raw material laminate RMB with a substrate via the peeling roller 68a. Accordingly, the web-like substrate film BF is peeled off from the optical film laminate F1 and wound up. The remaining portion RMR of the raw material laminate in which the optical film laminate F1 is cut is released from the adhesion state with the substrate film BF by being discharged of static electricity, so that when the web-like substrate film BF is wound up, it separates from the substrate film BF and is recovered, for example, by being dropped as it is. On the other hand, the optical film laminate F1 peeled off from the substrate film BF is sent out from the peeling device 68 without changing the conveying direction by the peeling roller 68a and is taken out by a conveying device 69 well-known to those skilled in the art. In this way, one or more optical film laminates F1 having arbitrary shapes can be obtained.

[0058] [Third Embodiment] FIG. 5 is a conceptual diagram of an apparatus 70 for manufacturing an optical film laminate having a raised portion according to the third embodiment. The apparatus 70 is a web-web type apparatus that laminates a web-shaped base film BF on a web-shaped raw material laminate RM to form a web-shaped raw material laminate RMB with a base material, and then charges the raw material laminate RMB with the base material and performs cutting with a laser beam. In the following, mainly, configurations different from those of the apparatus 50 of the first embodiment and the apparatus 60 of the second embodiment will be described.

[0059] The apparatus 50 is configured such that a sheet-shaped raw material laminate RM is laminated on a sheet-shaped base film BF to form a sheet-shaped raw material laminate RMB with a base material. In the apparatus 60, a plurality of sheet-shaped raw material laminates RM are continuously laminated on a web-shaped base film BF to form a web-shaped raw material laminate RMB with a base material. In contrast, in the apparatus 70, a web-shaped raw material laminate RM is laminated on a web-shaped base film BF to form a web-shaped raw material laminate RMB with a base material. For this reason, in the apparatus 70, the web-shaped 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 and the base film BF.

[0060] In the laminating device 72, a web-shaped raw material laminate RMB with a base material can be formed by passing the web-shaped raw material laminate RM and the web-shaped base film BF between a pair of laminating rolls 72a.

[0061] 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 a base material after the web-shaped raw material laminate RM is laminated on the web-shaped base film BF, whereby the raw material laminate RM and the base film MB are adhered by static electricity. The position of the charging device 73 is not limited to this, and the charging device 73 may be arranged to charge the web-shaped raw material laminate RM or the web-shaped base film BF before being laminated on the upstream side of the laminating device 72.

[0062] The raw material laminate RMB with a charged substrate is conveyed by a conveying device 74 and cut with a laser beam on a pedestal 75. The cut raw material laminate RMB with a substrate is then discharged from static electricity by a static eliminator 77. The conveying device 74, the pedestal 75, the laser cutting device 76, and the static eliminator 77, and their functions can be the same as those of the device 60.

[0063] In the raw material laminate RMB including the optical film laminate F1 from which static electricity has been removed by the static eliminator 77, the adhesion between the raw material laminate RMB with a substrate and the optical film laminate F1 and the web-shaped substrate film BF is released, and the optical film laminate F1 can be easily peeled off from the substrate film BF. Also in the device 70, in order to peel the optical film laminate F1 from the web-shaped substrate film BF, a peeling device 78 is provided downstream of the static eliminator 77.

[0064] The peeling device 78 has a peeling roller (or peeling bar) 78a, and the web-shaped substrate film BF is pulled in a direction away from the conveying direction of the raw material laminate RMB with a substrate via the peeling roller 78a. Therefore, the web-shaped substrate film BF is peeled off from the optical film laminate F1 and wound around a winding roller. Also, the remaining portion RMR of the web-shaped raw material laminate from which the optical film laminate F1 has been cut is released from the adhesion with the substrate film BF by being discharged from static electricity, and is wound in a direction different from the direction in which the web-shaped substrate film BF is wound via the peeling roller 78a. On the other hand, the optical film laminate F1 peeled off from the substrate film BF by discharging from static electricity and cut out from the web-shaped raw material laminate RM is sent out from the peeling device 78 without changing the conveying direction by the peeling roller 78a, and is taken out by a conveying device 79 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.

Example

[0065] Examples and comparative examples of the present invention will be described below. 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 carrier film was laminated on 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 substrate and charged with static electricity. In Examples 1 to 2 and Examples 4 to 6, charging was performed before nipping, and in Example 3, charging was performed after nipping. In Examples 1 to 5, negative charges were charged, and in Example 6, positive charges were charged.

[0066] Next, the amount of static electricity on the surface of the charged raw material laminate with a substrate was measured, and the raw material laminate with a substrate was cut with a laser beam from the side opposite to the side on which the carrier film was laminated (surface protection film side), leaving the carrier film. After cutting, the static electricity was removed, and for the optical film laminate obtained by peeling off the carrier film, the height of the raised portion formed at the end of the cut portion was measured.

[0067] On the other hand, in the comparative example, after nipping the raw material laminate with a lamination roller well-known to those skilled in the art, it was cut with a laser beam without charging, and the height of the raised portion of the optical film laminate from which the carrier film was removed was measured.

[0068] As the optical laminate, a polarizing film with a phase difference for mobile use (GRT1794XH1UHC) manufactured by Nitto Denko Corporation was used, and the thickness was 178 μm. As the carrier film, a PET film with a thickness of 25 μm was used. For the devices for charging and discharging static electricity, JPK-3 manufactured by Kasuga Electric Co., Ltd. was used in Examples 1 to 4 and Example 6, and PSM-2005PN manufactured by Kasuga Electric Co., Ltd. was used in Example 5. 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.

[0069] The height of the raised portion was measured as follows. For each of Examples 1 to 6 and the Comparative Example, 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 at the cut portion of each optical film laminate using a laser microscope (manufactured by Keyence Corporation). Fifty raised amounts were measured from each cross-sectional profile, and the average value of the fifty raised amounts was calculated. For each of the Examples and the Comparative Example, the average value of the raised amounts of the three optical film laminates thus calculated was further averaged, and this was taken as the height of the raised portion of the optical film laminate.

[0070]

Table 1

[0071] 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 side opposite to the carrier film of the raw material laminate with a substrate, and in Example 2, charging was performed from the carrier film side of the raw material laminate with a substrate. In any of the Examples, no raised portion occurred (Example 1) or, even if a raised portion occurred, the height of the raised portion was 1 μm (Example 2) on the adhesion surface where the carrier film was laminated (the "release liner side" in Table 1). On the other hand, raised portions with heights of 8 μm (Example 2) and 13 μm (Example 1) occurred on the open surface where the carrier film was not laminated (the "surface protection film side" in Table 1).

[0072] Example 3 is a case where the raw material laminate with a substrate was charged before the nip. The charging surface was the surface opposite to the carrier film. The numerical value of the static electricity amount in Example 3 was larger (i.e., the adhesive force due to static electricity was weaker) compared to Example 1 and Example 2, and was -0.2 kV to -0.5 kV. The output of the charging device in Example 3 was the same as that in Example 1 and Example 2, but it is considered that the static electricity amount at the time of measurement increased due to reasons such as the charge escaping when nipped after charging. In this Example, raised portions occurred on both the adhesion surface and the open surface, but the raised portions on the adhesion surface were lower than those on the open surface.

[0073] Example 4 is the case where charging is performed from the surface opposite to the carrier film after the nip. The amount of static electricity during measurement was about the same as in Example 3. In this example, the same charging device as in Examples 1 and 2 was operated at the same output to charge static electricity, but by increasing the distance to the charging surface compared to these examples, the amount of static electricity was adjusted to be about the same as in Example 3. Also in this example, as in Example 3, projections occurred on both the adhesion surface and the release surface, but the projections on the adhesion surface were lower than those on the release surface.

[0074] In Examples 3 and 4, since the numerical value of the amount of static electricity is larger than that in Examples 1 and 2 (that is, the adhesive force due to static electricity is weak), the adhesion between the raw material laminate and the carrier film is partially insufficient, and an air layer is formed by the impact during cutting with laser light. As a result, it is considered that higher projections occurred on the adhesion surface compared to Examples 1 and 2.

[0075] Example 5 is the case where the amount of static electricity is -11.0 kV to -12.0 kV, and charging was performed after the nip. When charging with such a small numerical value of static electricity (that is, the adhesive force due to static electricity is strong), although no projections occurred on the adhesion surface, there is a risk of problems such as attraction of foreign matter, poor peeling due to incomplete discharge, and adverse effects on peripheral devices due to atmospheric discharge.

[0076] Example 6 shows the results when the raw material laminate with a base material is charged with a positive charge opposite to that in Examples 1 to 5. The amount of static electricity charged was +5 kV to +7 kV. When charging with positive static electricity, although the absolute value of the amount of static electricity charged is larger than that in Examples 1 to 4, the adhesive force between the raw material laminate and the carrier film is weak, and the effect of suppressing projections was about the same as in Example 4.

[0077] The comparative example is the result when the raw material laminate with a substrate is cut with laser light without being charged. The raw material laminate with a substrate in the comparative example was also slightly charged due to friction or the like. In the comparative example, regardless of the presence or absence of the carrier film, large protrusions were generated on both the adhesion surface and the release surface.

Explanation of Signs

[0078] F1 Optical film laminate having protrusions on one surface 11 One surface 11a End 11b Edge 12 First protrusion 13 The other surface 13a End 13b Edge 15 End face F2 Optical film laminate having protrusions on both surfaces 21 One surface 21a End 21b Edge 22 First protrusion 23 The other surface 23a End 24 Second protrusion 25 End face BF Substrate film RM Raw material laminate RMB Raw material laminate with substrate RMR Remainder of raw material laminate TP Release tape CF Cover film 40 Charging device 41 Laser light 42 Static eliminator 50 Sheet - sheet type manufacturing device 51, 54, 59 Conveying device 52 Laminating device 52a Laminating roller 53 Charging device 55 Pedestal 56 Laser cutting device 57 Static eliminator 58 Peeling device 58a Bonding part 58b Peeling roller or peeling bar 60 Sheet-web type manufacturing apparatus 61, 69 Conveying device 62 Laminating device 62a Laminating roller 63 Charging device 65 Pedestal 66 Laser cutting device 67 Static eliminator 68 Peeling device 68a Peeling roller or peeling bar 70 Web-web type manufacturing apparatus 72 Laminating device 72a Laminating roller 73 Charging device 75 Pedestal 76 Laser cutting device 77 Static eliminator 78 Peeling device 78a Peeling roller or peeling bar

Claims

1. An optical film laminate having an arbitrary shape, wherein 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, the first resin film having a first raised portion at an end thereof, the second resin film having a second raised portion at an end corresponding to the end of the first resin film, the height of the first raised portion being different from the height of the second raised portion, Optical film laminate.

2. The optical film laminate according to claim 1, wherein either the height of the first raised portion or the height of the second raised portion is 1 μm.

3. The optical film laminate according to claim 1, wherein the sum of the height of the first raised portion and the height of the second raised portion is lower than 20% of the thickness of the optical film laminate in a portion without these raised portions.

4. The optical film laminate according to claim 3, wherein the sum of the height of the first raised portion and the height of the second raised portion is 35 μm or less.

5. The optical film laminate according to claim 1, wherein an end face of the optical film laminate between the first raised portion and the second raised portion is an inclined surface.

6. The optical film laminate 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.

7. The optical film laminate according to claim 6, wherein the height of the raised portion of the release liner is zero.

8. The optical film laminate according to claim 1, wherein the shape of the optical film laminate is a non-regular shape.

9. A method for manufacturing the optical film laminate according to any one of claims 1 to 8, 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 base material on either the first resin film or the second resin film of the raw material laminate to obtain a raw material laminate with a base material, a step of bringing the base material into close contact with the raw material laminate by charging static electricity to the raw material laminate, the base material, or the raw material laminate with a base material, or a plurality of these, a step of forming an arbitrary-shaped cut surface on the raw material laminate using a laser beam A step of removing static electricity from the raw material laminate with the substrate; A step of peeling one or more of the optical film laminates having the cut surface of an arbitrary shape from the substrate A method including.

10. The method according to claim 9, wherein the raw material laminate is a sheet-like laminate.

11. The method according to claim 9, wherein the substrate is a web-like substrate.

12. The method according to claim 9, wherein the substrate is a non-adhesive substrate.

13. The method according to claim 9, wherein the amount of static electricity to be charged is an amount of static electricity at which the substrate and the raw material laminate do not peel off when the cut surface is formed by the laser light.

14. The method according to claim 13, 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.

15. The method according to claim 14, wherein the amount of static electricity is -4.0 kV or more and -0.5 kV or less.

16. The substrate laminated on either the first resin film or the second resin film in the step of obtaining the raw material laminate with the substrate is a reused substrate peeled off in the step of peeling one or more of the optical film laminates having the cut surface of an arbitrary shape from the substrate. The method according to claim 9.

17. An apparatus for manufacturing the optical film laminate according to any one of claims 1 to 8, A transport device that transports 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 lamination device that laminates a substrate on either the first resin film or the second resin film of the raw material laminate to produce a raw material laminate with the substrate; A charging device that charges static electricity to the raw material laminate, the substrate, or the raw material laminate with the substrate, or a plurality of these, in order to bring the substrate and the raw material laminate into close contact; A laser cutting device that cuts the raw material laminate of the raw material laminate with the substrate to form one or more optical film laminates of an arbitrary shape; A static eliminator that removes static electricity from the raw material laminate with the substrate; A peeling device that peels one or more optical film laminates of an arbitrary shape from the substrate An apparatus comprising.

Images