Method for producing optical laminate

Abstract

To provide a method for manufacturing an optical laminate capable of enhancing the yield of an optical film raw material.SOLUTION: The present invention relates to a method for manufacturing an optical laminate 100 in which a film product part 2 and a resin sheet 3 are laminated. The present invention includes a product portion cutting step ST1 of cutting a plurality of film product portions 2 from an optical film material 1, and a laminating step ST2 of laminating the plurality of cut film product portions 2 and a plastic sheet 3 via an adhesive layer 12. The interval between the adjacent film product portions 2 cut out in the product portion-cutting step ST2 is smaller than the interval between the adjacent film product portions 2 laminated with the plastic sheet 3 in the laminating step ST1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an optical laminate in which a film product portion cut out from an original optical film and a resin sheet are laminated together, and more particularly, to a method for manufacturing an optical laminate that can increase the yield of the original optical film. [Background technology]

[0002] BACKGROUND ART Optical films such as polarizing films and retardation films have conventionally been used in image display devices such as televisions, personal computers, smartphones, smartwatches, and in-vehicle displays, as well as in eyeglasses and camera lenses. These optical films are produced as raw optical film sheets by being subjected to a stretching process or the like using a roll-to-roll method, and then cut into sheets having a shape appropriate for the intended use, and are attached to image display devices or the like.

[0003] Here, when an optical film is attached to an image display device or the like (especially when the image display device or the like has a curved shape), in addition to the film product portion, which is the portion used as the product, a gripping portion, which is a portion that grips the optical film, may be required around the film product portion (see, for example, Patent Document 1. Of the attachment member 12 described in Patent Document 1, the outer edge portion 12a corresponds to the gripping portion, and the portion inside the outer edge portion 12a corresponds to the film product portion).

[0004] However, when the raw optical film is cut into sheets including not only the film product portion but also the surrounding gripping portion, the cut optical film contains unnecessary gripping portions that are not used as products, which results in a problem of reduced yield of the raw optical film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-70282 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made to solve the problems of the conventional art as described above, and an object of the present invention is to provide a method for producing an optical laminate that can increase the yield of raw optical film. [Means for solving the problem]

[0007] In order to solve the above problem, the present invention provides a method for manufacturing an optical laminate, which includes a product part cutting process in which multiple film product parts are cut out from an original optical film, and a lamination process in which the cut-out multiple film product parts are laminated onto a resin sheet via an adhesive layer, wherein the distance between adjacent film product parts when cut out in the product part cutting process is smaller than the distance between adjacent film product parts laminated onto the resin sheet in the lamination process.

[0008] In the present invention, "the distance between adjacent film product portions" refers to the distance between the centers of adjacent film product portions. Furthermore, "the distance between adjacent film product portions when cut out in the product product portion cutting step is smaller than the distance between adjacent film product portions laminated with the resin sheet in the lamination step" refers to the maximum distance between adjacent film product portions when cut out in the product product portion cutting step being smaller than the maximum distance between adjacent film product portions laminated with the resin sheet in the lamination step, among combinations of adjacent film product portions. However, it is preferable that the distance between adjacent film product portions when cut out in the product product portion cutting step is smaller than the distance between adjacent film product portions laminated with the resin sheet in the lamination step for all combinations of adjacent film product portions, not just the relationship between the maximum distances. The optical laminate produced by the present invention is configured by laminating a film product portion and a resin sheet, and for example, the film product portion is used by being bonded to an object to be bonded, such as an image display device, and the resin sheet is used as a gripping portion when bonding the film product portion. According to the present invention, in the product portion cutting step, multiple film product portions are cut out from an optical film web, and in the lamination step, the cut-out multiple film product portions are laminated to a resin sheet via an adhesive layer. The present invention is characterized in that the distance between adjacent film product portions cut out in the product portion cutting step is smaller than the distance between adjacent film product portions laminated to the resin sheet in the lamination step. In other words, to ensure a portion of the resin sheet that can be used as a gripping portion when laminating to an object to be bonded (a portion not laminated with a film product portion), the distance between adjacent film product portions laminated to the resin sheet in the lamination step needs to be greater than a predetermined distance. However, because the distance between adjacent film product portions cut out in the product portion cutting step is smaller, the area of ​​the portion of the optical film web not used as a film product portion (a portion not cut out) can be smaller than the area of ​​the portion of the resin sheet that can be used as a gripping portion. This allows for a higher yield of optical film web compared to cutting not only film product portions but also gripping portions from an optical film web without using a resin sheet.

[0009] Preferably, the lamination process includes an inserting step in which a base having a plurality of recesses, each having a shape corresponding to the shape of the film product portion, is used to insert the plurality of cut-out film product portions into the plurality of recesses, and a resin sheet lamination step in which the resin sheet is laminated onto the plurality of film product portions inserted into the plurality of recesses.

[0010] According to the above-mentioned preferred method, the resin sheets are laminated with the cut-out film product portions fitted into the recesses of the base, which has the advantage of stabilizing the lamination. Furthermore, when the film product portions have a non-circular, irregular polygonal shape and an optical axis (e.g., a polarization axis), fitting the film product portions into recesses having a shape corresponding to the shape of the film product portions has the advantage of suppressing variation in the direction of the optical axes of the multiple film product portions.

[0011] Preferably, the base adheres the film product piece fitted into the recess to the bottom side of the recess.

[0012] According to the above-described preferred method, the film product parts fitted into the recesses are less likely to be misaligned relative to the recesses, thereby further stabilizing the lamination of the film product parts and the resin sheet. Furthermore, when the film product parts have noncircular, irregular polygonal shapes and optical axes, the film product parts are less likely to be misaligned, which further reduces variations in the directions of the optical axes of the multiple film product parts.

[0013] Preferably, the film product portion has an adhesive layer and a surface protective film laminated on the adhesive layer, and the lamination process has a peeling step between the fitting step and the resin sheet lamination step, in which in the fitting step, the cut-out film product portions are fitted into the recesses so that the surface protective film side of the cut-out film product portions is positioned opposite the bottom surface of the recess, in the peeling step, the surface protective film of the cut-out film product portions fitted into the recesses is peeled off to expose the adhesive layer, and in the resin sheet lamination step, the resin sheet is laminated onto the film product portions via the exposed adhesive layer.

[0014] According to the above-described preferred method, the resin sheet is laminated to a plurality of film product portions via the adhesive layers of the plurality of film product portions, so there is no need to provide an adhesive layer on the side of the resin sheet that will be laminated to the film product portions (the opposing side). This makes it possible to avoid problems such as the adhesive forming the adhesive layer on the portion of the resin sheet that is not laminated to the film product portions adhering to and contaminating the film product portions during lamination. Furthermore, by providing an adhesive layer on the resin sheet, it is possible to avoid problems such as the resin sheet adhering to the base via the adhesive layer on the portion of the resin sheet that is not laminated to the film product portions, making it difficult to remove. However, in the above-mentioned preferred method, it is also possible to provide an adhesive layer only on the portion of the resin sheet that will be laminated to the film product portion, thereby strengthening the lamination between the film product portion and the resin sheet.

[0015] Preferably, the resin sheet does not have a pressure-sensitive adhesive layer on the surface to be laminated onto the film product portion.

[0016] According to the above-mentioned preferred method, it is possible to reliably avoid problems such as the adhesive on the resin sheet adhering to the film product portion during lamination and causing contamination, or the resin sheet adhering to the base and becoming difficult to remove.

[0017] Preferably, the method includes a small piece cutting process for cutting the plurality of film product portions and the resin sheet laminated in the lamination process into small pieces, each of which includes one film product portion and a portion of the resin sheet on which the film product portion is not laminated.

[0018] According to the above-mentioned preferred method, an optical laminate (an optical laminate cut into small pieces) can be obtained immediately before being attached to an image display device or the like.

[0019] Preferably, the film product portion has an optical axis, and the variation in the direction of the optical axis of the plurality of film product portions before being cut into small pieces in the small piece cutting step is within ±1°.

[0020] Small variations in the direction of the optical axes of multiple film product portions, as in the preferred method described above, can be achieved, for example, by using a base having multiple recesses whose shapes correspond to the shapes of the film product portions, as described above.

[0021] The present invention is particularly effective when the film product has a shape that is likely to reduce the yield of the optical film web, specifically when the shape of the film product is not rectangular. [Effects of the Invention]

[0022] According to the present invention, when an optical laminate is produced in which a film product portion cut out from an optical film roll and a resin sheet are laminated together, the yield of the optical film roll can be increased. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a flow chart showing the outline of steps in a method for producing an optical laminate according to one embodiment of the present invention. [Figure 2] 2 is a diagram for schematically explaining a product portion cutting step ST1 shown in FIG. 1. FIG. [Figure 3] 2A to 2C are diagrams for schematically explaining the embedding step ST21 and the peeling step ST22 shown in FIG. [Figure 4] 1. FIG. 4 is a diagram for schematically explaining a resin sheet laminating step ST23 shown in FIG. [Figure 5] 1. FIG. 4 is a diagram for schematically explaining the small piece cutting step ST3 shown in FIG. [Figure 6] 1A and 1B are diagrams for schematically explaining an example of a method for bonding an optical film 11 to an object 200 to be bonded together. [Figure 7] FIG. 10 is a diagram illustrating an example of cutting out not only the film product portion 2 but also the grip portion 2a from the optical film roll 1 without using the resin sheet 3. DETAILED DESCRIPTION OF THE INVENTION

[0024] An embodiment of the present invention will be described below with reference to the accompanying drawings. Note that the drawings are for reference purposes only, and the dimensions, scale, and shapes of the components shown in the drawings may differ from the actual ones.

[0025] FIG. 1 is a flow diagram showing the outline of steps in a method for producing an optical laminate according to one embodiment of the present invention. As shown in FIG. 1, the manufacturing method according to this embodiment includes a product portion cutting process ST1, a lamination process ST2, and a small piece cutting process ST3, and is a method for manufacturing an optical laminate in which a film product portion and a resin sheet are laminated. Hereinafter, each of the steps ST1 to ST3 will be described in order.

[0026] <Product cutting process ST1> 2A and 2B are diagrams for explaining the product portion cutting step ST1, in which Fig. 2A is a plan view and Fig. 2B is a cross-sectional view. As shown in Fig. 2(a), in the product part cutting step ST1, a plurality of film product parts 2 (areas surrounded by closed curves in Fig. 2(a)) are cut out from an original optical film roll 1. Fig. 2(a) shows an example of a film product part 2 used for eyeglass lenses, and its shape is neither rectangular, circular nor regular polygonal. 2(b), the optical film roll 1 of this embodiment includes an optical film 11, a pressure-sensitive adhesive layer 12 provided on one side of the optical film 11, a surface protection film 13 laminated on the pressure-sensitive adhesive layer 12, a pressure-sensitive adhesive layer 14 provided on the other side of the optical film 11, and a release liner 15 laminated on the pressure-sensitive adhesive layer 14. The same is true for the film product part 2.

[0027] In the product part cutting step ST1, the optical film 11, the pressure-sensitive adhesive layer 12, the surface protective film 13, the pressure-sensitive adhesive layer 14, and the release liner 15 are all cut along the closed curve shown in Fig. 2(a) to cut out the film product part 2. The cutting method is not particularly limited, and an appropriate cutting method using, for example, a laser cutter, a rotary cutter, or a push-in blade (e.g., a Thomson blade) can be used. The components of the optical film roll 1 (components of the film product part 2), that is, the optical film 11, the pressure-sensitive adhesive layer 12, the surface protection film 13, the pressure-sensitive adhesive layer 14, and the release liner 15, will be described below.

[0028] [Optical Film 11] The optical film 11 may be, for example, a polarizing film. In a typical polarizing film, an appropriate transparent protective film is provided on one or both sides of the polarizer as needed. The polarizer may be, for example, a hydrophilic polymer film, such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or a partially saponified ethylene-vinyl acetate copolymer film, to which a dichroic substance, such as iodine or a dichroic dye, is adsorbed and then stretched to orient the dichroic substance. The transparent protective film provided on the surface of the polarizer is preferably made of a material having excellent transparency, mechanical strength, and thermal stability, such as a cellulose-based resin, a cyclic polyolefin-based resin, an acrylic-based resin, a phenylmaleimide-based resin, or a polycarbonate-based resin. An optically anisotropic film, such as a retardation plate, may also be used as the transparent protective film for the polarizer. The polarizer may be made of a liquid crystal compound. By using a polarizer made of a liquid crystal compound, durability against changes in optical properties upon heating can be satisfactorily satisfied without using a transparent protective film. As the liquid crystal compound, a lyotropic liquid crystal polymer is preferably used.

[0029] The optical film 1 may be a laminate of multiple films laminated together via an appropriate adhesive or pressure-sensitive adhesive. Examples of optical films other than polarizing films include films used in image display devices, such as retardation films, viewing angle widening films, viewing angle limiting (peeping prevention) films, and brightness enhancement films. The optical film may be provided with a touch sensor or the like. Furthermore, the surface of the optical film may be provided with a hard coat layer, an anti-reflection layer, an anti-glare layer, an anti-sticking layer, or the like, and may be subjected to a surface treatment for the purpose of improving adhesion, etc.

[0030] [Adhesive layers 12, 14] The pressure-sensitive adhesive layers 12 and 14 are preferably formed from an optically transparent pressure-sensitive adhesive. The pressure-sensitive adhesive layer 12 is interposed between the optical film 11 and the surface protection film 13 in the product portion cut-out step ST1, and is used to bond and laminate the film product portion 2 and the resin sheet 3 in the lamination step ST2, as described below. The pressure-sensitive adhesive layer 14 is interposed between the optical film 11 and the release liner 15 in the product portion cut-out step ST1, and is used to bond and laminate the optical film 11 and the bonding object 200 when bonding the optical film 11 and the bonding object 200, such as an image display device, as described below.

[0031] The adhesive constituting the adhesive layers 12, 14 can be appropriately selected from adhesives having a base polymer such as an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyvinyl ether, a vinyl acetate / vinyl chloride copolymer, a modified polyolefin, an epoxy-based material, a fluorine-based material, or a rubber-based material such as natural rubber or synthetic rubber. In particular, acrylic adhesives are preferably used because they have excellent optical transparency, adequate adhesive properties such as wettability, cohesiveness, and adhesion, and excellent weather resistance and heat resistance. The adhesive layers 12, 14 may be formed by laminating multiple adhesive layers.

[0032] The adhesive constituting the adhesive layers 12, 14 may be a photocurable adhesive that can be cured by light irradiation after lamination. By photocuring the adhesive by irradiating it with UV or the like after lamination, adhesive reliability can be improved. The photocurable adhesive preferably contains, for example, a polymer, a monomer or oligomer having a photopolymerizable functional group, and a photopolymerization initiator. A crosslinkable monomer having two or more polymerizable functional groups in one molecule may be used as the monomer or oligomer having a photopolymerizable functional group.

[0033] The thickness of the pressure-sensitive adhesive layers 12 and 14 is not particularly limited, and is generally about 5 to 500 μm, and preferably about 5 to 50 μm.

[0034] [Surface protection film 13, release liner 15] Surface protection film 13 is removably attached to the adhesive layer 12. By temporarily attaching surface protection film 13 to the adhesive layer 12, the exposed surface of adhesive layer 12 can be protected until the film product portion 2 and resin sheet 3 are bonded together, as described below. Similarly, release liner 15 is removably attached onto pressure-sensitive adhesive layer 14. By temporarily attaching release liner 15 onto pressure-sensitive adhesive layer 14, the exposed surface of pressure-sensitive adhesive layer 14 can be protected until optical film 11 and object 200 to be bonded are bonded together, as described below.

[0035] The surface protection film 13 and the release liner 15 are preferably made of plastic films such as polyethylene, polypropylene, polyethylene terephthalate, polyester film, etc. The thickness of the surface protection film 13 and the release liner 15 is generally about 5 to 200 μm, and preferably about 10 to 150 μm. The surface of surface protection film 13 that is bonded to pressure-sensitive adhesive layer 12 may be subjected to a release treatment using a silicone-based release agent or the like. Similarly, the surface of release liner 15 that is bonded to pressure-sensitive adhesive layer 14 may be subjected to a release treatment using a silicone-based release agent or the like.

[0036] <Lamination process ST2> In the lamination step ST2, the film product parts 2 cut out in the product part cutting step ST1 are laminated on a resin sheet 3 via an adhesive layer 12. In the lamination step ST2, a plurality of film product parts 2 are laminated on each resin sheet 3. Specifically, as shown in FIG. 1, the laminating step ST2 includes an inserting step ST21, a peeling step ST22, and a resin sheet laminating step ST23. Steps ST21 to ST23 will be explained in order below.

[0037] [Fitting step ST21] FIG. 3 is a diagram illustrating the fitting step ST21 and the peeling step ST22. FIG. 3(a) shows a plan view of the base 20 used in the fitting step ST21, and FIG. 3(b) shows a cross-sectional view of the base 20. FIG. 3(c) shows a plan view of the base 20 with multiple film product units 2 fitted into multiple recesses 21, and FIG. 3(d) shows a cross-sectional view of the base 20 with multiple film product units 2 fitted into multiple recesses 21. FIG. 3(e) shows an enlarged cross-sectional view of one film product unit 2 fitted into one recess 21 of the base 20. FIG. 3(f) is an enlarged cross-sectional view illustrating the peeling step ST22. 3(a) and 3(b), in the fitting step ST21, a base 20 is prepared having a plurality of recesses 21, each having a shape corresponding to the shape of the film product part 2. Specifically, in a plan view, the recesses 21 have a shape that is the same as or slightly larger than the shape of the film product part 2. Furthermore, the recesses 21 have a depth that is slightly smaller than the thickness of the film product part 2 (smaller by the thickness of the surface protection film 13). The base 20 may be made of a relatively hard material such as metal or hard synthetic resin, but is preferably made of a relatively soft material to prevent scratches on the film product portion 2. For example, the base 20 is made of a flexible synthetic resin, rubber, elastomer, or the like.

[0038] 3(c), 3(d), and 3(e), in fitting step ST21, the base 20 having the above configuration is used to fit the film product parts 2 cut out in product part cutting step ST1 into the recesses 21. Specifically, as shown in FIG. 3(e), the cut film product parts 13 are fitted into the recesses 21 so that the surface protection film 13 of the cut film product parts 2 is positioned on the opposite side (top side) of the recesses 21 from the bottom surface 21a. The recesses 21 are formed in the base 20 so that the distance between adjacent film product sections 2 when cut out in the product section cutting step ST1 (e.g., distance L1 shown in FIG. 2(a)) is smaller than the distance between adjacent film product sections 2 when fitted into the recesses 21 (e.g., distance L2 shown in FIG. 3(c)). In the examples shown in FIGS. 2(a) and 3(c), the distance between adjacent film product sections 2 when cut out in the product section cutting step ST1 (FIG. 2(a)) is smaller than the distance between adjacent film product sections 2 when fitted into the recesses 21 (FIG. 3(c)). However, the present invention is not limited to this. It is sufficient that the maximum distance between adjacent film product sections 2 when cut out in the product section cutting step ST1 is smaller than the maximum distance between adjacent film product sections 2 when fitted into the recesses 21 among the combinations of adjacent film product sections 2.

[0039] In addition, it is preferable that the base 20 is configured to adsorb the film product part 2 fitted into the recess 21 to the bottom side of the recess 21 so that the film product part 2 fitted into the recess 21 is less likely to shift position relative to the recess 21. Although the suction method is not particularly limited, an air suction method is preferred because it allows for easy holding and release of the film product portion 2. For example, a hole (not shown) connected to a suction device (not shown) may be provided in the bottom surface 21a of the recess 21, and the suction device may be driven to suck air through the hole, causing the film product portion 2 to be suctioned to the bottom surface 21a of the hole 21.

[0040] [Peeling step ST22] As shown in FIG. 3(f), in peeling step ST22, the surface protection films 13 of the film product parts 21 fitted in the recesses 21 are peeled off to expose the pressure-sensitive adhesive layer 12. The peel strength at the interface between the surface protection film 13 and the pressure-sensitive adhesive layer 12 is preferably smaller than the peel strength at the interface between the optical film 11 and the pressure-sensitive adhesive layer 12, the peel strength at the interface between the optical film 11 and the pressure-sensitive adhesive layer 14, and the peel strength at the interface between the release liner 15 and the pressure-sensitive adhesive layer 14. This makes it possible to easily peel off only the surface protection film 13 from the film product part 2. The releasability of the surface protection film 13 can be adjusted, for example, by the thickness of the surface protection film 13 and the type and thickness of a release agent applied to the surface of the surface protection film 13 (the surface to be bonded to the pressure-sensitive adhesive layer 12). In this specification, the structure after the surface protection film 13 is peeled off from the film product portion 2 is also referred to as the film product portion 2.

[0041] [Resin Sheet Lamination Step ST23] 4A and 4B are diagrams illustrating the resin sheet laminating step ST23. Fig. 4A shows a plan view, Fig. 4B shows a cross-sectional view, and Fig. 4C shows an enlarged cross-sectional view of one film product portion 2 and its vicinity. 4, in the resin sheet laminating step ST23, a resin sheet 3 is laminated on the film product parts 2 (film product parts 2 after peeling off the surface protective film 13) fitted into the recesses 21. Specifically, one resin sheet 3 is laminated on the film product parts 2 with the exposed adhesive layer 12 interposed therebetween. Since the resin sheet 3 is laminated with the film product portion 2 fitted into the recess 21 of the base 20, the lamination can be stabilized. Furthermore, when the optical film 1 has an optical axis, such as a polarizing film, the resin sheet 3 can be laminated with reduced variation in the direction of the optical axis of the multiple film product portions 2. Furthermore, when the base 20 is configured to adsorb the film product portion 2 fitted into the recess 21 to the bottom surface 21a of the recess 21, the film product portion fitted into the recess is less likely to become misaligned with respect to the recess, which makes it possible to further stabilize the lamination of the film product portion 2 and the resin sheet 3 and further reduce variation in the direction of the optical axis of the multiple film product portions 2.

[0042] The constituent material of the resin sheet 3 is preferably a plastic film, similar to the surface protective film 13 and the release liner 15. The thickness of the resin sheet 3 is preferably greater than that of the surface protective film 13 and the release liner 15, in order to increase the rigidity of the optical laminate 100 described below and improve the handleability. The resin sheet 3 may be made thicker by laminating multiple films via an appropriate adhesive or pressure-sensitive adhesive. It is preferable that the resin sheet 3 does not have an adhesive layer on the surface 31 that is to be laminated to the film product part 2. This reliably prevents problems such as the adhesive on the resin sheet 3 adhering to and contaminating the film product part 2 during lamination, and the resin sheet 3 adhering to the base 20 and becoming difficult to remove.

[0043] As described above, the distance between adjacent film product sections 2 when cut out in the product section cutting step ST1 (e.g., distance L1 shown in FIG. 2(a)) is smaller than the distance between adjacent film product sections 2 fitted in the recesses 21 (e.g., distance L2 shown in FIG. 3(c)). Therefore, the distance between adjacent film product sections 2 when cut out in the product section cutting step ST1 (e.g., distance L1 shown in FIG. 2(a)) is smaller than the distance between adjacent film product sections 2 laminated with the resin sheet 3 (e.g., distance L2 shown in FIG. 4(a)). Note that in the examples shown in FIGS. 2(a) and 4(c), for all combinations of adjacent film product sections 2, the distance between adjacent film product sections 2 when cut out in the product section cutting step ST1 (FIG. 2(a)) is smaller than the distance between adjacent film product sections 2 laminated with the resin sheet 3 (FIG. 4(a)). However, the present invention is not limited to this. In any combination of adjacent film product parts 2, the maximum distance between adjacent film product parts 2 when cut out in the product part cutting process ST1 should be smaller than the maximum distance between adjacent film product parts 2 laminated with the resin sheet 3.

[0044] As described above, in the lamination process ST2, by performing the embedding step ST21, the peeling step ST22 and the resin sheet lamination step ST23, an optical laminate 100' is obtained in which multiple film product parts 2 and one resin sheet 3 are laminated on the base 20 via the adhesive layer 12.

[0045] <Small piece cutting process ST3> The small piece cutting step ST3 is performed after the optical laminate 100' is removed from the base 20. Fig. 5 is a diagram illustrating the small piece cutting step ST3. Fig. 5(a) shows a plan view seen from the film product portion 2 side, and Fig. 5(b) shows a cross-sectional view. Fig. 5(c) is an enlarged cross-sectional view of the optical laminate 100 cut into small pieces. As shown in Figure 5, in the small piece cutting process ST3, the optical laminate 100' (multiple film product parts 2 and resin sheet 3 laminated in the lamination process ST2) is cut into small pieces, each of which includes one film product part 2 and a portion 32 of the resin sheet 3 where no film product part 2 is laminated, to obtain the optical laminate 100. Specifically, in the small piece cutting step ST3, one resin sheet 3 is cut along the dashed lines shown in Fig. 5(a) to cut it into a plurality of optical laminates 100. As with the product part cutting step ST1, the cutting method is not particularly limited, and an appropriate cutting method using, for example, a laser cutter, a rotary cutter, a push blade (for example, a Thomson blade), or the like can be used.

[0046] As mentioned above, when the optical film 1 constituting the film product portion 2 has an optical axis like a polarizing film, the resin sheet 3 can be stacked while suppressing the variation in the direction of the optical axis of the multiple film product portions 2 (i.e., the variation in the direction of the optical axis of the multiple film product portions 2 in the optical laminate 100' can be suppressed), so for example, it is possible to suppress the variation in the direction of the optical axis of the multiple film product portions 2 before they are cut into small pieces in the small piece cutting process ST3 to within ±1°.

[0047] FIG. 6 is a diagram for explaining an example of a method for bonding the optical film 11 to the object 200 to be bonded. When bonding the optical film 11 to an object 200 to be bonded, such as an image display device, first, as shown in Figure 6(a), the release liner 15 is peeled off from the optical laminate 100 obtained in the small piece cutting process ST3 to expose the pressure-sensitive adhesive layer 14. The peel strength at the interface between release liner 15 and pressure-sensitive adhesive layer 14 is preferably smaller than the peel strength at the interface between resin sheet 3 and pressure-sensitive adhesive layer 12, the peel strength at the interface between optical film 11 and pressure-sensitive adhesive layer 12, and the peel strength at the interface between optical film 11 and pressure-sensitive adhesive layer 14. This makes it possible to easily peel off only release liner 15 from optical laminate 100. The releasability of release liner 15 can be adjusted, for example, by the thickness of release liner 15 and the type and thickness of a release agent applied to the surface of release liner 15 (the surface to be bonded to pressure-sensitive adhesive layer 14).

[0048] 6(b), the optical laminate 100 from which the release liner 15 has been peeled is bonded to the object 200 to be bonded via the exposed pressure-sensitive adhesive layer 14. At this time, the portion 32 of the resin sheet 3 on which the film product portion 2 is not laminated can be used as a gripping portion for gripping the optical laminate 100 from which the release liner 15 has been peeled.

[0049] Finally, as shown in Figure 6(c), by peeling off the resin sheet 3 and the adhesive layer 12, a structure is obtained in which the optical film 11 that constituted the film product portion 2 and the object to be bonded 200 are laminated via the adhesive layer 14. The peel strength at the interface between the optical film 11 and the pressure-sensitive adhesive layer 12 is preferably smaller than the peel strength at the interface between the resin sheet 3 and the pressure-sensitive adhesive layer 12, the peel strength at the interface between the optical film 11 and the pressure-sensitive adhesive layer 14, and the peel strength at the interface between the object 200 to be bonded and the pressure-sensitive adhesive layer 14. This allows easy peeling of only the resin sheet 3 and the pressure-sensitive adhesive layer 12. The releasability of the optical film 11 can be adjusted, for example, by the type and thickness of a release agent applied to the surface of the optical film 11 (the surface to be bonded to the pressure-sensitive adhesive layer 12). It can also be adjusted by a hard coat layer, an anti-reflection layer, an anti-glare layer, an anti-sticking layer, etc., provided on the surface of the optical film.

[0050] According to the manufacturing method of this embodiment described above, in the product cut-out step ST1, a plurality of film product portions 2 are cut out from the optical film roll 1, as shown in Fig. 2, and in the lamination step ST2, the cut-out film product portions 2 are laminated onto a resin sheet 3 via a pressure-sensitive adhesive layer 12, as shown in Figs. 3 and 4. The distance between adjacent film product portions 2 when cut out in the product cut-out step ST1 (for example, distance L1 shown in Fig. 2(a)) is smaller than the distance between adjacent film product portions 2 laminated onto the resin sheet 3 in the lamination step ST2 (for example, distance L2 shown in Fig. 4(a)). In other words, to ensure that there is a portion of the resin sheet 3 (portion 32 where the film product portion 2 is not laminated) that can be used as a gripping portion when laminating the resin sheet 3 to the object 200 to be laminated, the distance between adjacent film product portions 2 laminated to the resin sheet 3 in the lamination process ST2 must be greater than a predetermined distance. However, since the distance between adjacent film product portions 2 when cut out in the product portion cutting process ST1 is small, the area of ​​the portion of the optical film roll 1 that is not used as the film product portion 2 (the portion that is not cut out, the portion indicated by symbol 2' in Figure 2(a)) can be made smaller than the area of ​​the portion 32 of the resin sheet that can be used as a gripping portion.

[0051] 7 is a diagram illustrating an example of cutting out not only the film product portion 2 but also the grip portion 2a from the optical film roll 1 without using the resin sheet 3 (in the example shown in FIG. 7, multiple rectangular portions each consisting of the film product portion 2 and the grip portion 2a are cut out). The area of ​​the grip portion 2a shown in FIG. 7 is equal to the area of ​​the portion 32 of the resin sheet 3 shown in FIG. 5(a) that can be used as the grip portion and that does not have the film product portion 2 laminated thereon. According to the manufacturing method of this embodiment, as described above, the area of ​​the portion of the optical film roll 1 that is not used as the film product portion 2 (the portion 2' that is not cut out) can be made smaller than the area of ​​the portion 32 of the resin sheet that can be used as a gripping portion. Therefore, as shown in FIG. 7, the yield of the optical film roll 1 can be increased compared to when not only the film product portion 2 but also the gripping portion 2a are cut out from the optical film roll 1 without using the resin sheet 3. [Explanation of symbols]

[0052] 1. Optical film roll 2. Film Products Department 3. Resin sheet 11. Optical film 12, 14... Adhesive layer 13. Surface protection film 15. Release liner 20···Pedestal 21. Recess 100, 100'...optical laminate 200....Object to be bonded ST1: Product cutting process ST2: Lamination process ST3: Small piece cutting process ST21: Fitting step ST22: Peeling step ST23...Resin sheet lamination step

Claims

1. A method for producing an optical laminate in which a film product portion and a resin sheet are laminated, comprising: a product portion cutting step of cutting out a plurality of the film product portions from an optical film roll; a lamination step of laminating the cut-out film product portions and the resin sheet via a pressure-sensitive adhesive layer, the distance between adjacent film product portions when cut out in the product portion cutting step is smaller than the distance between adjacent film product portions laminated with the resin sheet in the laminating step; A method for producing an optical laminate.

2. The lamination step includes: a fitting step of fitting the cut-out film product sections into a plurality of recesses using a base having a plurality of recesses each having a shape corresponding to the shape of the film product section; a resin sheet laminating step of laminating the resin sheet onto the plurality of film product portions fitted into the plurality of recesses, A method for producing the optical laminate according to claim 1 .

3. the base adheres the film product part fitted into the recess to the bottom surface of the recess; A method for producing the optical laminate according to claim 2 .

4. the film product portion has a pressure-sensitive adhesive layer and a surface protection film laminated on the pressure-sensitive adhesive layer, The lamination step includes a peeling step between the fitting step and the resin sheet lamination step, In the fitting step, the cut-out film product portions are fitted into the recesses so that the surface protection film sides of the cut-out film product portions are positioned opposite the bottom surfaces of the recesses, In the peeling step, the surface protection films of the film product parts fitted in the recesses are peeled off to expose the pressure-sensitive adhesive layer, In the resin sheet laminating step, the resin sheet is laminated on the plurality of film product portions via the exposed pressure-sensitive adhesive layer. The method for producing the optical laminate according to claim 2 or 3.

5. the resin sheet does not have a pressure-sensitive adhesive layer on the surface to be laminated to the film product portion; The method for producing the optical laminate according to claim 4 .

6. a small piece cutting step of cutting the plurality of film product portions and the resin sheet laminated in the laminating step into small pieces each including one of the film product portions and a portion of the resin sheet on which no film product portion is laminated, A method for producing the optical laminate according to claim 1 or 2.

7. the film product portion has an optical axis; the variation in the directions of the optical axes of the plurality of film product portions before being cut into small pieces in the small piece cutting step is within ±1°; The method for producing the optical laminate according to claim 6 .

8. The shape of the film product portion is not rectangular. A method for producing the optical laminate according to claim 1 or 2.

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