Method for manufacturing optical laminate with adhesive layer

Abstract

A method for producing an optical laminate with an adhesive layer, which is obtained by laminating an optical film, a first adhesive cured layer, a first liquid crystal layer, a second adhesive cured layer, a second liquid crystal layer, and an adhesive layer, comprises: a step for obtaining a liquid crystal layer laminate with a base material layer; laminating the first liquid crystal layer with the base material layer and the second liquid crystal layer with the base material layer such that the first liquid crystal layer and the second liquid crystal layer face each other with the second adhesive cured layer interposed therebetween; a step for obtaining a liquid crystal layer laminate in which at least the first base material layer is peeled off from the liquid crystal layer laminate with the base material layer; a step for obtaining an optical laminate in which an optical film is laminated on the first exposed surface side of the liquid crystal layer laminate exposed by peeling off the first base material layer with a first adhesive curing layer interposed therebetween; a step for peeling off the second substrate layer from the liquid crystal layer laminate with the substrate layer or the optical laminate; and a step for laminating an adhesive layer on the second exposed surface side of the optical laminate exposed by peeling off the second base material layer.

Description

[0001] This application is a divisional application of the application with the application number 201910191239.4 and the invention title "Manufacturing Method of an Optical Laminate with an Adhesive Layer" submitted by the applicant. The filing date of the parent application of this application is March 13, 2019, and the priority date is March 15, 2018. Technical Field

[0002] The present invention relates to a manufacturing method of an optical laminate with an adhesive layer. Background Art

[0003] Compared with liquid crystal display devices and the like, an organic EL display device using an organic light-emitting diode (OLED) can not only achieve light weight and thinness, but also achieve high image quality such as a wide viewing angle, a fast response speed, and a high contrast ratio. Therefore, it is used in various fields such as smartphones, TVs, and digital cameras. In addition, for an organic EL display device, since it is ultrathin and can display without using a backlight, device shapes such as bending and winding have also been proposed. In an organic EL display device, in order to suppress the reduction in visibility caused by the reflection of external light, it is known to use a circular polarizing plate or the like to improve the antireflection performance.

[0004] For example, in Patent Documents 1 and 2, as a film applied to an image display panel such as an organic EL display device, an optical film having an antireflection function is described. According to the description, the optical film has a retardation layer formed using a liquid crystal material.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-230386

[0008] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2015-79256 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] For the above-described optical film, in order not to impair the light weight and thinness that are characteristics of a display device, thinning and bendability above the current level are required. In addition, the above optical film is used after being attached to an optical display element. However, once so-called reverse curling occurs in the optical film, that is, the side attached to the optical display element curls concavely, it tends to be prone to poor conditions such as bubbles being mixed in when the optical film is attached to the optical display element or wrinkles being formed, and being observed as unevenness. Such poor conditions cause defects in the image display panel. Therefore, it is desired to suppress the reverse curling of the optical film.

[0011] An object of the present invention is to provide a method for manufacturing an optical laminate with an adhesive layer that suppresses reverse curling.

[0012] Method for solving the problem

[0013] The present invention provides a method for manufacturing an optical laminate with an adhesive layer as shown below.

[0014] 〔1〕A method for manufacturing an optical laminate with an adhesive layer, which is a method for manufacturing an optical laminate with an adhesive layer obtained by laminating an optical film, a first adhesive cured layer, a first liquid crystal layer, a second adhesive cured layer, a second liquid crystal layer, and an adhesive layer,

[0015] This manufacturing method includes:

[0016] A step of preparing a first liquid crystal layer with a substrate layer, the first liquid crystal layer with a substrate layer having a first substrate layer and the first liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the first substrate layer;

[0017] A step of preparing a second liquid crystal layer with a substrate layer, the second liquid crystal layer with a substrate layer having a second substrate layer and the second liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the second substrate layer;

[0018] A step of obtaining a liquid crystal layer laminate with a substrate layer, in which the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer are laminated so that the first liquid crystal layer and the second liquid crystal layer face each other with the second adhesive cured layer interposed therebetween to obtain a liquid crystal layer laminate with a substrate layer;

[0019] A step of obtaining a liquid crystal layer laminate, in which at least the first substrate layer is peeled off from the liquid crystal layer laminate with a substrate layer to obtain a liquid crystal layer laminate;

[0020] A step of obtaining an optical laminate, in which the optical film is laminated on the first exposed surface side of the liquid crystal layer laminate exposed due to peeling of the first substrate layer with the first adhesive cured layer interposed therebetween to obtain an optical laminate;

[0021] A step of peeling the second substrate layer from the liquid crystal layer laminate with a substrate layer or the optical laminate; and

[0022] A step of laminating the adhesive layer on the second exposed surface side of the optical laminate exposed due to peeling of the second substrate layer.

[0023] 〔2〕According to the method for manufacturing an optical laminate with an adhesive layer described in 〔1〕, wherein,

[0024] The step of obtaining the optical laminate includes:

[0025] A step of forming a first adhesive composition layer, which forms a first adhesive composition layer containing a first adhesive composition for forming the first cured adhesive layer on at least one of the optical film and the first exposed surface of the liquid crystal layer laminate; and

[0026] A step of forming the first cured adhesive layer, which cures the first adhesive composition layer after laminating the optical film on the first exposed surface side with the first adhesive composition layer interposed therebetween.

[0027] 〔3〕The method for manufacturing an optically laminated body with an adhesive layer according to 〔1〕 or 〔2〕, wherein

[0028] The step of obtaining the liquid crystal layer laminate with a substrate layer includes:

[0029] A step of forming a second adhesive composition layer, which forms a second adhesive composition layer containing an adhesive composition for forming the second cured adhesive layer on at least one of the first liquid crystal layer of the first liquid crystal layer with a substrate layer and the second liquid crystal layer of the second liquid crystal layer with a substrate layer; and

[0030] A step of forming the second cured adhesive layer, which cures the second adhesive composition layer after laminating the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer in such a manner that the first liquid crystal layer and the second liquid crystal layer face each other with the second adhesive composition layer interposed therebetween.

[0031] 〔4〕The method for manufacturing an optically laminated body with an adhesive layer according to any one of 〔1〕 to 〔3〕, wherein

[0032] The step of obtaining the liquid crystal layer laminate is a step of peeling the first substrate layer from the liquid crystal layer laminate with a substrate layer and not peeling the second substrate layer,

[0033] The manufacturing method includes a step of peeling the second substrate layer from the optically laminated body.

[0034] 〔5〕The method for manufacturing an optically laminated body with an adhesive layer according to any one of 〔1〕 to 〔3〕, wherein

[0035] The step of obtaining the liquid crystal layer laminate is a step of peeling the first substrate layer and the second substrate layer from the liquid crystal layer laminate with a substrate layer to obtain a liquid crystal layer laminate.

[0036] 〔6〕The method for manufacturing an optically laminated body with an adhesive layer according to any one of 〔1〕 to 〔5〕, wherein

[0037] The steps of the laminated adhesive layer include:

[0038] The step of preparing an adhesive layer with a release layer in which the adhesive layer and the release layer are laminated, and

[0039] The step of laminating the adhesive layer of the adhesive layer with the release layer to the second exposed surface of the optical laminate and then peeling off the release layer.

[0040] 〔7〕A method for manufacturing an optical laminate with an adhesive layer, which is a method for manufacturing an optical laminate with an adhesive layer in which an optical film, a first adhesive cured layer, a first liquid crystal layer, a second adhesive cured layer, a second liquid crystal layer, and an adhesive layer are laminated in sequence,

[0041] This manufacturing method includes:

[0042] The step of preparing a first liquid crystal layer with a substrate layer, where the first liquid crystal layer with a substrate layer has a first substrate layer and the first liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the first substrate layer;

[0043] The step of preparing a second liquid crystal layer with a substrate layer, where the second liquid crystal layer with a substrate layer has a second substrate layer and the second liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the second substrate layer;

[0044] The step of obtaining a liquid crystal layer laminate with a substrate layer, where the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer are laminated in such a way that the first liquid crystal layer and the second liquid crystal layer face each other with the second adhesive cured layer interposed therebetween;

[0045] The step of obtaining a liquid crystal layer laminate, where at least the second substrate layer is peeled off from the liquid crystal layer laminate with a substrate layer to obtain a liquid crystal layer laminate;

[0046] The step of obtaining a liquid crystal layer laminate with an adhesive layer, where the adhesive layer is laminated on the second exposed surface side of the liquid crystal layer laminate exposed due to peeling off the second substrate layer to obtain a liquid crystal layer laminate with an adhesive layer;

[0047] The step of peeling off the first substrate layer from the liquid crystal layer laminate with a substrate layer or the liquid crystal layer laminate with an adhesive layer; and

[0048] The step of laminating the optical film with the first adhesive cured layer interposed therebetween on the first exposed surface side of the liquid crystal layer laminate with an adhesive layer exposed due to peeling off the first substrate layer.

[0049] 〔8〕According to the method for manufacturing an optical laminate with an adhesive layer described in 〔7〕, wherein,

[0050] The step of obtaining the liquid crystal layer laminate with an adhesive layer includes:

[0051] A step of preparing an adhesive layer with a release layer in which the adhesive layer and the release layer are laminated, and

[0052] A step of laminating the adhesive layer of the adhesive layer with the release layer on the second exposed surface of the liquid crystal layer laminate and then peeling off the release layer.

[0053] 〔9〕The method for manufacturing an optical laminate with an adhesive layer according to any one of 〔1〕 to 〔8〕, wherein the optical film includes a polarizing plate.

[0054] 〔10〕The method for manufacturing an optical laminate with an adhesive layer according to any one of 〔1〕 to 〔9〕, wherein the optical film includes a polarizing plate with a protective film laminated on at least one surface thereof.

[0055] Advantageous Effects of the Invention

[0056] According to the present invention, an optical laminate with an adhesive layer that suppresses reverse curling can be manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 (a) to (d) are schematic cross-sectional views schematically showing an example of the manufacturing process of the optical laminate with an adhesive layer of the present invention.

[0058] Figure 2 (a) and (b) are schematic cross-sectional views schematically showing Figure 1 subsequent parts of the manufacturing process of the optical laminate with an adhesive layer shown.

[0059] Figure 3 (a) and (b) are schematic cross-sectional views schematically showing Figure 2 subsequent parts of the manufacturing process of the optical laminate with an adhesive layer shown.

[0060] Figure 4 (a) and (b) are schematic cross-sectional views schematically showing Figure 3 subsequent parts of the manufacturing process of the optical laminate with an adhesive layer shown.

[0061] Figure 5 (a) and (b) are schematic cross-sectional views schematically showing Figure 4 subsequent parts of the manufacturing process of the optical laminate with an adhesive layer shown.

[0062] Figure 6 (a) to (d) are schematic cross-sectional views schematically showing an example of the manufacturing process of another optical laminate with an adhesive layer of the present invention.

[0063] Figure 7 (a) to (e) are schematic cross-sectional views schematically showing an example of the manufacturing process of an optical laminate with an adhesive layer different from the present invention.

[0064] Figure 8 (a) to (d) are schematically showing Figure 7 schematic cross-sectional views of the subsequent part of the manufacturing process of the optical laminate with an adhesive layer shown.

[0065] Figure 9 (a) and (b) are schematically showing Figure 8 schematic cross-sectional views of the subsequent part of the manufacturing process of the optical laminate with an adhesive layer shown.

[0066] Explanation of symbols

[0067] 10, 10p First liquid crystal layer with a substrate layer, 11, 11p First substrate layer, 12, 12p First liquid crystal layer, 20, 20p Second liquid crystal layer with a substrate layer, 21, 21p Second substrate layer, 22, 22p Second liquid crystal layer, 25 Second liquid crystal layer with a composition layer, 31 First adhesive cured layer, 31p 1'st adhesive layer, 32 Second adhesive cured layer, 32a Second adhesive composition layer, 32p 2'st adhesive layer, 33 Second adhesive layer, 33p 3'st adhesive layer, 40 Liquid crystal layer laminate with a substrate layer, 41, 43 Liquid crystal layer laminate, 45 Liquid crystal laminate with an adhesive layer, 50 First adhesive layer with an adhesive layer, 52p 2'st release layer, 53 Release layer, 53p 3'st release layer, 58 Second adhesive layer with a release layer, 60, 60p Optical film, 61 Optical film with an adhesive layer, 70, 70p Optical laminate, 71, 71p Optical laminate with a substrate layer (optical laminate), 80, 81 Optical laminate with an adhesive layer. Detailed description of the preferred embodiments

[0068] Hereinafter, preferred embodiments of the manufacturing method of the optical laminate with an adhesive layer of the present invention will be described with reference to the accompanying drawings.

[0069] [Embodiment 1 (Manufacturing method of an optical laminate with an adhesive layer)]

[0070] Figures 1 to 5 is a schematic cross-sectional view schematically showing an example of the manufacturing process of the optical laminate with an adhesive layer of the present embodiment. In the figure, W represents the width direction. The optical laminate with an adhesive layer 80 manufactured by the manufacturing method of the optical laminate with an adhesive layer 80 of the present embodiment is as Figure 5As shown in Fig. (b), an optical film 60, a first adhesive cured layer 31, a first liquid crystal layer 12, a second adhesive cured layer 32, a second liquid crystal layer 22, and an adhesive layer 33 are stacked in this order. A release layer 53 may be provided on the side of the adhesive layer 33 opposite to the second liquid crystal layer 22.

[0071] A method for manufacturing an optical laminate 80 with an adhesive layer includes preparing Figure 1 the first liquid crystal layer 10 with a substrate layer as shown in Fig. (a), and Figure 1 the second liquid crystal layer 20 with a substrate layer as shown in Fig. (b). The first liquid crystal layer 10 with a substrate layer has a first substrate layer 11 and a first liquid crystal layer 12 formed by polymerizing a polymerizable liquid crystal compound on the first substrate layer 11. The second liquid crystal layer 20 with a substrate layer has a second substrate layer 21 and a second liquid crystal layer 22 formed by polymerizing a polymerizable liquid crystal compound on the second substrate layer 21.

[0072] The step of preparing the first liquid crystal layer 10 with a substrate layer may include the step of forming the first liquid crystal layer 12, that is, coating a liquid crystal layer-forming composition containing a polymerizable liquid crystal compound on the first substrate layer 11 and drying it, and then polymerizing and curing the polymerizable liquid crystal compound by irradiation with active energy rays such as ultraviolet rays to form the first liquid crystal layer 12. Similarly, the step of preparing the second liquid crystal layer 20 with a substrate layer may include the step of forming the second liquid crystal layer 22, that is, coating a liquid crystal layer-forming composition containing a polymerizable liquid crystal compound on the second substrate layer 21 and drying it, and then polymerizing and curing the polymerizable liquid crystal compound by irradiation with active energy rays such as ultraviolet rays to form the second liquid crystal layer 22.

[0073] Then, a step of forming a second adhesive composition layer 32a is carried out, and a second adhesive composition layer 32a containing a second adhesive composition for forming the second adhesive cured layer 32 is formed on the surface of the second liquid crystal layer 22 side of the second liquid crystal layer 20 with a substrate layer. By this step, a second liquid crystal layer 25 with a composition layer ( Figure 1 (c)) can be obtained.

[0074] The second liquid crystal layer 25 with a composition layer is stacked in this order with a second adhesive composition layer 32a, a second liquid crystal layer 22, and a second substrate layer 21 as shown in Figure 1 (c). The step of forming the second adhesive composition layer 32a may include the step of coating the second adhesive composition on the surface of the second liquid crystal layer 22 side of the second liquid crystal layer 20 with a substrate layer.

[0075] After laminating the second adhesive composition layer 32a of the obtained second liquid crystal layer 25 with a composition layer and the first liquid crystal layer 12 of the first liquid crystal layer 10 with a substrate layer ( Figure 1(d)), the second adhesive composition layer 32a is cured to form a second adhesive cured layer 32, and a liquid crystal layer laminate 40 with a substrate layer is obtained. Figure 2 (a). The method for curing the second adhesive composition layer 32a can be appropriately selected according to the type of the second adhesive composition, etc. For example, active energy ray irradiation, heat treatment, addition of a curing agent, etc. can be cited. The type of the second adhesive composition and its curing method will be described later. The liquid crystal layer laminate 40 with a substrate layer is as Figure 2 (a) shows, the first substrate layer 11, the first liquid crystal layer 12, the second adhesive cured layer 32, the second liquid crystal layer 22, and the second substrate layer 21 are laminated in this order. The first substrate layer 11 is peeled off from the liquid crystal layer laminate 40 with a substrate layer, and the second substrate layer 21 is not peeled off, whereby a liquid crystal layer laminate 41 is obtained. Figure 2 (b). The liquid crystal layer laminate 41 is as Figure 2 (b) shows, the first liquid crystal layer 12, the second adhesive cured layer 32, the second liquid crystal layer 22, and the second substrate layer 21 are laminated in this order.

[0076] Next, a step of forming a first adhesive composition layer 31a containing a first adhesive composition for forming a first adhesive cured layer 31 on the optical film 60 is performed. By this step, an optical film 61 with a composition layer can be obtained. Figure 3 (a). The optical film 61 with a composition layer is as Figure 3 (a) shows, the optical film 60 and the first adhesive composition layer 31a are laminated. The step of forming the first adhesive composition layer 31a may include a step of coating the first adhesive composition on the surface of the optical film 60.

[0077] Thereafter, the first adhesive composition layer 31a of the optical film 61 with a composition layer is bonded to the first liquid crystal layer 12 (first exposed surface) of the liquid crystal layer laminate 41 exposed by peeling off the first substrate layer 11. Figure 3 (b). Thereafter, the first adhesive composition layer 31a is cured, whereby a first adhesive cured layer 31 is formed and an optical laminate 71 (optical laminate) with a substrate layer is obtained. Figure 4 (a). The method for curing the first adhesive composition layer 31a can be appropriately selected according to the type of the first adhesive composition, etc. For example, active energy ray irradiation, heat treatment, addition of a curing agent, etc. can be cited. The type of the first adhesive composition and its curing method will be described later. The optical laminate 71 with a substrate layer is as Figure 4As shown in (a), an optical film 60, a first adhesive cured layer 31, a first liquid crystal layer 12, a second adhesive cured layer 32, a second liquid crystal layer 22, and a second substrate layer 21 are stacked in this order. By peeling off the second substrate layer 21 from the optical laminate 71 with the substrate layer, the optical laminate 70 can be obtained ( Figure 4 (b)). The optical laminate 70 includes an optical film 60, a first adhesive cured layer 31, a first liquid crystal layer 12, a second adhesive cured layer 32, and a second liquid crystal layer 22 stacked in this order.

[0078] Then, a bonding layer 58 with a release layer, which is obtained by laminating a release layer 53 and a bonding layer 33, is prepared ( Figure 5 (a)). The process of preparing the bonding layer 58 with the release layer may include a process of forming the bonding layer 33 by coating an adhesive composition on the release layer 53 and drying it, etc. Additionally, if necessary, a process of covering the surface of the bonding layer 33 opposite to the release layer 53 with another release layer may be provided.

[0079] The bonding layer 33 of the prepared bonding layer 58 with the release layer is bonded to the second liquid crystal layer 22 (second exposed surface) of the optical laminate 70 exposed due to the peeling of the second substrate layer 21, and an optical laminate 80 with a bonding layer is obtained ( Figure 5 (b)). The optical laminate 80 with the bonding layer obtained at this time has a release layer 53. When the optical laminate 80 with the bonding layer is to be laminated on an optical display element, the release layer 53 can be peeled off, and the bonding layer 33 can be bonded to the optical display element to form an image display panel.

[0080] In the method for manufacturing the above-described optical laminate 80 with an adhesive layer, a first liquid crystal layer 10 with a substrate layer and a second liquid crystal layer 20 with a substrate layer (hereinafter sometimes referred to as "liquid crystal layers with a substrate layer" collectively), in which a polymerizable compound is polymerized and cured on a first substrate layer 11 and a second substrate layer 21 (hereinafter sometimes referred to as "substrate layers" collectively), are used. In the liquid crystal layer with a substrate layer, a liquid crystal layer-forming composition containing a polymerizable liquid crystal compound is usually coated on the substrate layer and dried, and the polymerizable liquid crystal compound is polymerized and cured by irradiation with active energy rays such as ultraviolet rays, whereby a first liquid crystal layer 12 and a second liquid crystal layer 22 (hereinafter sometimes referred to as "liquid crystal layers" collectively) can be formed. It is presumed that in the liquid crystal layer formed through the above-described steps of coating, drying, polymerization, and curing, shrinkage stress generated during drying of the coated liquid crystal layer-forming composition and curing accompanying polymerization of the polymerizable liquid crystal compound remains. It is considered that in the state of the liquid crystal layer with a substrate layer in which the liquid crystal layer is present on the substrate layer, the above-described shrinkage stress is suppressed by the substrate layer. However, as described above, since the substrate layer is peeled off in the process of manufacturing the optical laminate 80 with an adhesive layer, the shrinkage stress of the liquid crystal layer is released due to peeling of the substrate layer. At this time, when the liquid crystal layer is adhered to the optical film, there may be a case where deformation in which the laminate of the optical film and the liquid crystal layer warps into an arch shape with the liquid crystal layer side as the inner side (hereinafter sometimes referred to as "reverse curling") occurs due to the shrinkage stress released by peeling the substrate layer.

[0081] Regarding the generation of such curling, it is considered that the more times the substrate layer is peeled off to release the shrinkage stress of the liquid crystal layer after laminating the optical film 60 and the liquid crystal layer, the more likely it is to occur. For example, as Figures 7 to 9 shown, in the case of manufacturing an optical laminate with an adhesive layer by laminating liquid crystal layers on an optical film in sequence, after laminating the optical film and the liquid crystal layer, the number of times of releasing the shrinkage stress of the liquid crystal layer tends to increase. Figures 7 to 9 is a schematic cross-sectional view schematically showing an example of a manufacturing process of an optical laminate with an adhesive layer different from the manufacturing process of the optical laminate with an adhesive layer shown in Figures 1 to 5 .

[0082] Figure 9 In the method for manufacturing the optical laminate 80p with an adhesive layer shown in (b), first, a first liquid crystal layer 10p with a substrate layer having a first liquid crystal layer 12p formed by polymerizing a polymerizable liquid crystal compound on a first substrate layer 11p ( Figure 7 (b)) is adhered to a first adhesive layer 31p of an adhesive layer-containing optical film 61p obtained by laminating an optical film 60p and a first adhesive layer 31p ( Figure 7 (a)) on the first adhesive layer 31p side of the first liquid crystal layer 12p of Figure 7(c)). Thereafter, the first base material layer 11p is peeled off ( Figure 7 (d)), and the first liquid crystal layer 12p exposed by this peeling is bonded to the second adhesive layer 32p formed on the second peeling layer 52p ( Figure 7 (e)), and the second peeling layer 52p is peeled off ( Figure 8 (a)).

[0083] Then, the second liquid crystal layer 20p with a base material layer having a second liquid crystal layer 22p formed by polymerizing a polymerizable liquid crystal compound on the second base material layer 21p ( Figure 8 (b)) is bonded to the second adhesive layer 32p on the side of the second liquid crystal layer 22p to obtain an optical laminate 71p with a base material layer ( Figure 8 (c)). The second base material layer 21p is peeled off from the optical laminate 71p with a base material layer to obtain an optical laminate 70p ( Figure 8 (d)).

[0084] Then, the second liquid crystal layer 22p exposed by peeling off the second base material layer 21p of the optical laminate 70p is bonded to the third adhesive layer 33p formed on the third peeling layer 53p ( Figure 9 (a)) to obtain an optical laminate 80p with an adhesive layer ( Figure 9 (b)).

[0085] As described above, in the manufacturing process shown in Figures 7 to 9 , after the first liquid crystal layer 12p is laminated on the optical film 60p with the first adhesive layer 31p interposed therebetween, the first base material layer 11p is peeled off, and after the second liquid crystal layer 22p is laminated on the first liquid crystal layer 12p with the second adhesive layer 32p interposed therebetween, the second base material layer 21p is peeled off. From this, it can be speculated that in each process of peeling off the first base material layer 11p and the second base material layer 21p, the shrinkage stresses of the first liquid crystal layer 12p and the second liquid crystal layer 22p are respectively released, and thus it is easy to generate reverse curling in the optical laminate 70p.

[0086] In contrast, Figures 1 to 5 in the manufacturing method of the optical laminate 80 with an adhesive layer according to the present embodiment shown in Figure 2 , first, the first liquid crystal layer 10 with a base material layer and the second liquid crystal layer 20 with a base material layer are laminated with the second adhesive curing layer 32 interposed therebetween to obtain a liquid crystal layer laminate 40 with a base material layer ( Figure 2 (a)). Thereafter, the first base material layer 11 is peeled off to obtain a liquid crystal layer laminate 41 in which the shrinkage stress of the first liquid crystal layer 12 is released ( Figure 4 (b)), and this liquid crystal layer laminate 41 is laminated with the optical film 60 with the first adhesive curing layer 31 interposed therebetween ( Figure 4(b)). Therefore, according to the manufacturing method of the optical laminate 80 with the adhesive layer, the peeling process after laminating the first liquid crystal layer 12 and the second liquid crystal layer 22 on the optical film 60 is only the process of peeling the second substrate layer 21. Compared with the manufacturing process Figures 7 to 9 shown, after laminating the liquid crystal layer on the optical film, the number of times of releasing the shrinkage stress of the liquid crystal layer can be reduced. Thus, it can be considered that compared with the optical laminate 70p and the optical laminate 80p with the adhesive layer obtained by using the manufacturing process Figures 7 to 9 shown, Figures 1 to 5 in the manufacturing method of the optical laminate 80 with the adhesive layer shown, the anti-curling generated in the optical laminate 70 and the optical laminate 80 with the adhesive layer can be reduced.

[0087] In addition, Figure 4 in the optical laminate 71 with the substrate layer shown in (a), the optical film 60 and the first liquid crystal layer 12 are laminated with the first adhesive cured layer 31 interposed therebetween, and the first liquid crystal layer 12 and the second liquid crystal layer 22 are laminated with the second adhesive cured layer 32 interposed therebetween. On the other hand, Figure 8 in the optical laminate 71p with the substrate layer shown in (c), the optical film 60p and the first liquid crystal layer 12p are laminated with the 1' adhesive layer 31p interposed therebetween, and the first liquid crystal layer 12p and the second liquid crystal layer 22p are laminated with the 2' adhesive layer 32p interposed therebetween. The first adhesive cured layer 31, the second adhesive cured layer 32 are higher in rigidity and more difficult to deform than the 1' adhesive layer 31p and the 2' adhesive layer 32p. Therefore, it can be speculated that even if the second substrate layer 21 is peeled from the optical laminate 71 with the substrate layer Figure 4 shown in (a), it is easy to maintain the state of suppressing the shrinkage stress of the first liquid crystal layer 12 and the second liquid crystal layer 22 by the first adhesive cured layer 31 and the second adhesive cured layer 32. In contrast, it can be considered that when the second substrate layer 21 is peeled from the optical laminate 71 with the substrate layer Figure 8 shown in (c), affected by the shrinkage stress of the second liquid crystal layer 22, the 1' adhesive layer 31p, the 2' adhesive layer 32p, and the optical film 60p are easy to deform, and it is easy to generate anti-curling in the optical laminate 70. Thus, compared with the optical laminate 70p and the optical laminate 80p with the adhesive layer obtained by using the manufacturing process Figures 7 to 9 shown, Figures 1 to 5 in the manufacturing method of the optical laminate 80 with the adhesive layer shown, it is easy to reduce the anti-curling generated in the optical laminate 70 and the optical laminate 80 with the adhesive layer.

[0088] By reducing the reverse curling generated in the optical laminate 70 as described above, when the optical laminate 80 with an adhesive layer obtained using the optical laminate 70 is attached to an optical display element, it is possible to suppress poor conditions such as air bubbles being mixed in between the optical laminate with an adhesive layer and the optical display element, the generation of wrinkles, or the occurrence of misalignment during attachment.

[0089] In addition, as Figure 7 (e) shows, after laminating the optical film 60p and the first liquid crystal layer 12p, a second adhesive layer 32p is sometimes provided on the first liquid crystal layer 12p. In this case, as described above, after laminating the second adhesive layer 32p provided on the second release layer 52p together with the second release layer 52p on the first liquid crystal layer 12p, there is a case where the second release layer 52p is peeled off. The process of peeling off the second release layer 52p can also be a cause for easily generating reverse curling in the optical laminate 70p.

[0090] On the other hand, Figures 1 to 5 In the manufacturing method of the optical laminate 80 with an adhesive layer according to the present embodiment shown, the first liquid crystal layer 12 and the second liquid crystal layer 22 are attached with the second adhesive curing layer 32 interposed therebetween to obtain Figure 2 (b) the liquid crystal layer laminate 41 shown. Thereafter, this liquid crystal layer laminate 41 is laminated on the optical film 60. Therefore, in the manufacturing method of the optical laminate 80 with an adhesive layer according to the present embodiment, compared with Figures 7 to 9 the manufacturing process of the optical laminate 80p with an adhesive layer shown, there is at least no process of peeling off the second release layer 52p, and thus the number of layers peeled off after being laminated on the optical film 60 can be reduced. Therefore, it can be considered that in the manufacturing method of the optical laminate 80 with an adhesive layer, compared with the manufacturing process of the optical laminate 80p with an adhesive layer, it is easier to suppress the reverse curling generated in the optical laminate 80 with an adhesive layer.

[0091] Regarding the reverse curling generated in the optical laminate, it can be considered that the smaller the thickness and rigidity of the optical film 60 contained in the optical laminate, the more easily it is affected by the release of the shrinkage stress caused by the liquid crystal layer. In addition, it can be considered that the greater the thickness and rigidity of the substrate layer, the greater the shrinkage stress remaining in the liquid crystal layer, and thus the more easily it is affected by the shrinkage stress released when peeling off the substrate layer. Therefore, the manufacturing method of the optical laminate according to the present embodiment is suitable for the case where the thickness of the optical film 60 is 2 μm or more and 500 μm or less. The thickness of the optical film 60 can be 10 μm or more, and in addition, it can be 350 μm or less, or 200 μm or less, or 150 μm or less.

[0092] Note that in the present embodiment, the first liquid crystal layer 10 with a substrate layer, the second liquid crystal layer 20 with a substrate layer, the second liquid crystal layer 25 with a composition layer, the optical laminate 70, the adhesive layer 58 with a release layer, and other film-like materials used for manufacturing the optical laminate with an adhesive layer are preferably long-sized film-like materials, and it is preferable to carry out each process while continuously transporting them. The width direction W is a direction orthogonal to the length direction of the film-like material.

[0093] The manufacturing method of the optical laminate of the present embodiment can be changed as in the following modification examples. In addition, the above-described embodiment and the following modification examples can be arbitrarily combined.

[0094] (Modification Example 1 of Embodiment 1)

[0095] In the above description, the case where the second liquid crystal layer 25 with a composition layer having a second adhesive composition layer 32a provided on the second liquid crystal layer 22 side of the second liquid crystal layer 20 with a substrate layer ( Figure 1 (c)), and the first liquid crystal layer 12 of the first liquid crystal layer 10 with a substrate layer is laminated on the second adhesive composition layer 32a has been described as an example. However, as long as a liquid crystal layer laminate 40 with a substrate layer in which the first liquid crystal layer 11 of the first liquid crystal layer 10 with a substrate layer and the second liquid crystal layer 22 of the second liquid crystal layer 20 with a substrate layer are laminated with the second adhesive cured layer 32 interposed therebetween ( Figure 2 (a)) can be obtained, it is not limited thereto. For example, a second adhesive composition layer 32a can be provided on the first liquid crystal layer 12 side of the first liquid crystal layer 10 with a substrate layer, and after laminating the second liquid crystal layer 22 of the second liquid crystal layer 20 with a substrate layer on the second adhesive composition layer 32a, the second adhesive composition layer 32a can be cured to form a second adhesive cured layer 32. In addition, a second adhesive composition layer 32a can also be formed on both the first liquid crystal layer 12 side of the first liquid crystal layer 10 with a substrate layer and the second liquid crystal layer 22 side of the second liquid crystal layer 20 with a substrate layer.

[0096] (Modification Example 2 of Embodiment 1)

[0097] In the above description, the first adhesive composition layer 31a is provided on the optical film 60 to obtain an optical film 61 with a composition layer ( Figure 3(a)) The case where the liquid crystal layer laminate 41 is laminated on the first adhesive composition layer 31a of the optical film 61 with the composition layer has been described as an example. However, as long as the optical film 60 can be laminated with the exposed surface (the first liquid crystal layer 12) of the liquid crystal layer laminate 41 exposed by peeling off the first base material layer 11 with the first adhesive composition layer 31a interposed therebetween, it is not limited thereto. For example, a liquid crystal layer laminate with a composition layer provided with a first adhesive composition layer 31a on the exposed surface (the first liquid crystal layer 12) of the liquid crystal layer laminate 41 can be obtained. After the optical film 60 is laminated on the first adhesive composition layer 31a, the first adhesive composition layer 31a is cured to form the first adhesive cured layer 31. In this case, the liquid crystal layer laminate with a composition layer only needs to sequentially include a first adhesive composition layer 31a, a first liquid crystal layer 12, a second adhesive cured layer 32, a second liquid crystal layer 22, and a second base material layer 21.

[0098] (Modification Example 3 of Embodiment 1)

[0099] In the above description, taking the case of obtaining Figure 2 the liquid crystal layer laminate 41 shown in (a) by peeling off the first base material layer 11 from the liquid crystal layer laminate 40 with a base material layer without peeling off the second base material layer 21, laminating the optical film 60 and the liquid crystal layer laminate 41 with the first adhesive cured layer 31 interposed therebetween, and then peeling off the second base material layer 21 as an example has been described. However, it is not limited thereto. For example, it is also possible to peel off the first base material layer 11 and the second base material layer 21 from Figure 2 the liquid crystal layer laminate 40 shown in (a) with a base material layer to obtain a liquid crystal layer laminate, and laminate the optical film 60 with the first adhesive cured layer 31 interposed on the exposed surface side of the liquid crystal layer laminate exposed by peeling off the first base material layer 11. The liquid crystal layer laminate obtained by peeling off the first base material layer 11 and the second base material layer 21 from the liquid crystal layer laminate 40 with a base material layer sequentially includes a first liquid crystal layer 12, a second adhesive cured layer 32, and a second liquid crystal layer 22. Figure 2 (a) shown in the liquid crystal layer laminate 40 with a base material layer to obtain a liquid crystal layer laminate, and laminate the optical film 60 with the first adhesive cured layer 31 interposed on the exposed surface side of the liquid crystal layer laminate exposed by peeling off the first base material layer 11. The liquid crystal layer laminate obtained by peeling off the first base material layer 11 and the second base material layer 21 from the liquid crystal layer laminate 40 with a base material layer sequentially includes a first liquid crystal layer 12, a second adhesive cured layer 32, and a second liquid crystal layer 22.

[0100] [Embodiment 2 (Manufacturing Method of Optical Laminate with Adhesive Layer)]

[0101] Figure 6 (a) to (d) are schematic cross-sectional views schematically showing an example of the manufacturing process of the optical laminate with an adhesive layer of the present embodiment. In the figure, W represents the width direction. The optical laminate with an adhesive layer 81 manufactured by the manufacturing method of the optical laminate with an adhesive layer of the present embodiment is the same as the optical laminate with an adhesive layer 80 ( Figure 5 (b)) described in the previous embodiment. As Figure 6As shown in (d), an optical film 60, a first adhesive cured layer 31, a first liquid crystal layer 12, a second adhesive cured layer 32, a second liquid crystal layer 22, and an adhesive layer 33 are stacked in sequence. A release layer 53 may also be provided on the side of the adhesive layer 33 opposite to the second liquid crystal layer 22.

[0102] In the method for manufacturing the optical laminate 81 with an adhesive layer, the same as the manufacturing method described in the previous embodiment is obtained Figure 2 The liquid crystal layer laminate 40 with a substrate layer as shown in (a) is prepared Figure 5 The adhesive layer 58 with a release layer as shown in (a). For the process of obtaining the liquid crystal layer laminate 40 with a substrate layer, as described in the previous embodiment based on Figure 1 (a) to (d) and Figure 2 (a) As described, for the process of preparing the adhesive layer 58 with a release layer, as described in the previous embodiment based on Figure 5 (a) As described, so its description is omitted.

[0103] Then, from Figure 2 The second substrate layer 21 is peeled off from the liquid crystal layer laminate 40 with a substrate layer as shown in (a) without peeling off the first substrate layer 11, and a liquid crystal layer laminate 43 is obtained ( Figure 6 (a)). The liquid crystal layer laminate 43 is as Figure 6 (a) As shown, the first substrate layer 11, the first liquid crystal layer 12, the second adhesive cured layer 32, and the second liquid crystal layer 22 are stacked in sequence. The second liquid crystal layer 22 (second exposed surface) of the liquid crystal layer laminate 43 exposed due to peeling off the second substrate layer 21 is bonded to the adhesive layer 33 of the adhesive layer 58 with a release layer to obtain a liquid crystal laminate 45 with an adhesive layer ( Figure 6 (b)). The liquid crystal laminate 45 with an adhesive layer is as Figure 6 (b) As shown, the first substrate layer 11, the first liquid crystal layer 12, the second adhesive cured layer 32, the second liquid crystal layer 22, the adhesive layer 33, and the release layer 53 are stacked in sequence.

[0104] Next, prepare Figure 3 The optical film 61 with a composition layer as shown in (a). For the process of obtaining the optical film 61 with a composition layer, as described in the previous embodiment based on Figure 3 (a) and (b) As described, so its description is omitted. Thereafter, the first substrate layer 11 is peeled off from the liquid crystal laminate 45 with an adhesive layer ( Figure 6(c)) After laminating the first adhesive composition layer 31a of the optical film 61 with the composition layer on the first liquid crystal layer 12 (first exposed surface) exposed by peeling off the first base material layer 11, the first adhesive composition layer 31a is cured, thereby forming the first adhesive cured layer 31 to obtain the optical laminate 81 with the adhesive layer ( Figure 6 (d)).

[0105] In the manufacturing method of the above optical laminate 81 with the adhesive layer, a liquid crystal layer laminate 43 in which the first liquid crystal layer 12 and the second liquid crystal layer 22 are laminated with the second adhesive cured layer 32 interposed therebetween is obtained, and then a liquid crystal layer laminate 45 with the adhesive layer in which the adhesive layer 33 is laminated on the second liquid crystal layer 22 is obtained. Thereafter, the first base material layer is peeled off from the liquid crystal layer laminate 45 with the adhesive layer, and the optical film 61 is laminated with the first adhesive cured layer 31 interposed therebetween. Therefore, for the same reasons as those described in the previous embodiment, it can be considered that the reverse curling of the obtained optical laminate 81 with the adhesive layer can be suppressed. Thus, when the optical laminate 81 with the adhesive layer is attached to the optical display element, poor conditions such as air bubbles being mixed in between the optical laminate and the optical display element, wrinkles being formed, and attachment errors being generated can be suppressed.

[0106] It should be noted that in this embodiment, the film-like materials such as the first liquid crystal layer 10 with the base material layer, the second liquid crystal layer 20 with the base material layer, the adhesive layer 58 with the release layer, the optical film 60, and the optical film 61 with the composition layer used for manufacturing the optical laminate with the adhesive layer are preferably all long-sized film-like materials, and it is preferable to carry out each process while continuously transporting them.

[0107] The width direction W is the direction orthogonal to the length direction of the film-like material.

[0108] The manufacturing method of the optical laminate of this embodiment can also be changed as in the following modification examples. In addition, the above embodiment and the following modification examples can be arbitrarily combined.

[0109] (Modification Example 1 of Embodiment 2)

[0110] In the above description, in order to obtain Figure 3(a) shows the case where the optical film 61 with the composition layer is taken as an example, and the first adhesive composition layer 31a of the optical film 61 with the composition layer is laminated on the first liquid crystal layer 12 exposed by peeling the first substrate layer 11 from the liquid crystal layer laminate 45 with the adhesive layer. However, as long as the optical film 60 can be laminated with the first adhesive composition layer 31a interposed between the first exposed surface (the first liquid crystal layer 12) of the liquid crystal layer laminate 45 with the adhesive layer exposed by peeling the first substrate layer 11, it is not limited thereto. For example, the first adhesive composition layer 31a can be provided on the first exposed surface (the first liquid crystal layer 12) of the liquid crystal layer laminate 45 with the adhesive layer from which the first substrate layer 11 has been peeled, and the optical film 60 can be laminated on the first adhesive composition layer 31a. In addition, the first adhesive composition layer 31a can be formed on both the first exposed surface (the first liquid crystal layer 12) of the liquid crystal layer laminate 45 with the adhesive layer from which the first substrate layer 11 has been peeled and the optical film 60.

[0111] (Modification 2 of Embodiment 2)

[0112] In the above description, Figure 2 the liquid crystal layer laminate 43 shown in (a) with the substrate layer is obtained by peeling the second substrate layer 21 without peeling the first substrate layer 11, Figure 6 and the case where the liquid crystal layer laminate 43 is laminated with the adhesive layer 33 of the adhesive layer 58 with the release layer and then the first substrate layer 11 is peeled is taken as an example for illustration. However, it is not limited thereto. For example, Figure 2 the first substrate layer 11 and the second substrate layer 21 can be peeled from the liquid crystal layer laminate 40 with the substrate layer shown in (a) to obtain a liquid crystal layer laminate, and the second liquid crystal layer side of the liquid crystal layer laminate is laminated with the adhesive layer 58 with the release layer to obtain a liquid crystal layer laminate with the adhesive layer. Then, on the first liquid crystal layer 12 side of the liquid crystal layer laminate with the adhesive layer, the optical film 60 is laminated with the first adhesive composition layer 31a interposed therebetween. In this case, the liquid crystal layer laminate is laminated with the first liquid crystal layer 12, the second adhesive cured layer 32, and the second liquid crystal layer 22 in sequence, and the liquid crystal layer laminate with the adhesive layer is laminated with the first liquid crystal layer 12, the second adhesive cured layer 32, the second liquid crystal layer 22, the adhesive layer 33, and the release layer 53 in sequence.

[0113] The above describes the embodiments of the present invention and their modifications. However, the present invention is not limited to these embodiments and their modifications. For example, the steps of the above embodiments and their modifications can be combined and implemented. Hereinafter, the steps common to all the embodiments and their modifications will be described in detail.

[0114] (Optical Film)

[0115] The optical film may be a polarizer, a polarizing plate having a protective layer formed on at least one surface of the polarizer, a polarizing plate with a protective film having a protective film laminated on at least one surface of the polarizing plate, a reflective film, a semi-transmissive reflective film, a brightness enhancement film, an optical compensation film, a film with an antiglare function, etc. The optical film may have a single-layer structure or may be a laminated optical film having a multi-layer structure of two or more layers. In this specification, the so-called "polarizer" refers to a layer having the property of transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis when non-polarized light is incident.

[0116] (Polarizer)

[0117] As the polarizer, any suitable polarizer can be used. In this specification, the so-called "polarizer" refers to a linear polarizer having the property of transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis when non-polarized light is incident. For example, the resin film forming the polarizer may be a single-layer resin film or a laminated film of two or more layers. The polarizer may be a cured film obtained by aligning a dichroic pigment in a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound.

[0118] As a specific example of a polarizer composed of a single-layer resin film, there can be mentioned a polarizer obtained by subjecting a hydrophilic polymer film such as a polyvinyl alcohol (hereinafter sometimes simply referred to as "PVA")-based film, a partially methylalated PVA-based film, an ethylene-vinyl acetate copolymer-based partially saponified film, etc. to a dyeing treatment using a dichroic substance such as iodine or a dichroic dye and a stretching treatment, a polyene-based oriented film such as a dehydrated product of PVA or a dehydrochlorinated product of polyvinyl chloride, etc. Since it has excellent optical properties, a polarizer obtained by dyeing a PVA-based film with iodine and performing uniaxial stretching is preferably used.

[0119] The polyvinyl alcohol-based resin can be produced by saponifying a polyvinyl acetate-based resin. The polyvinyl acetate-based resin may be, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and other monomers capable of copolymerizing with vinyl acetate. As other monomers capable of copolymerizing with vinyl acetate, for example, there can be mentioned unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamide-based compounds having an ammonium group, etc.

[0120] The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin can be modified. For example, polyvinyl formal, polyvinyl acetal, etc. modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1000 to 10000, preferably about 1500 to 5000.

[0121] The film obtained by forming a film of this polyvinyl alcohol-based resin is used as a raw material film for a polarizer. The method of forming a film of the polyvinyl alcohol-based resin is not particularly limited, and a publicly known method can be used for film formation. The film thickness of the polyvinyl alcohol-based resin raw material film is, for example, about 10 to 100 μm, preferably about 10 to 60 μm, and more preferably about 15 to 30 μm.

[0122] As another method for manufacturing a polarizer, a manufacturing method including the following steps can be cited. That is, first, a substrate film is prepared, and a solution of a resin such as a polyvinyl alcohol-based resin is coated on the substrate film, and drying for removing the solvent, etc. is performed to form a resin layer on the substrate film. It should be noted that a primer layer can be formed in advance on the surface of the substrate film where the resin layer is to be formed. As the substrate film, a resin film such as PET can be used. As the material for the primer layer, a resin obtained by crosslinking a hydrophilic resin used in a polarizer, etc. can be cited.

[0123] Then, if necessary, the amount of solvent such as moisture in the resin layer is adjusted. Thereafter, the substrate film and the resin layer are uniaxially stretched. Next, the resin layer is dyed with a dichroic pigment such as iodine so that the dichroic pigment is adsorbed on the resin layer and oriented. Next, if necessary, the resin layer adsorbed with the dichroic pigment and oriented is treated with an aqueous boric acid solution, and a cleaning step of rinsing off the aqueous boric acid solution is performed. Thus, a resin layer adsorbed with the dichroic pigment and oriented, that is, a film of a polarizer, can be manufactured. A publicly known method can be adopted in each step.

[0124] The uniaxial stretching of the substrate film and the resin layer can be performed before dyeing, during dyeing, during the boric acid treatment after dyeing, or uniaxial stretching can be performed separately in these multiple stages. The substrate film and the resin layer can be uniaxially stretched in the MD direction (film conveyance direction). In this case, it can be stretched uniaxially between rolls with different circumferential speeds, or a hot roll can be used for uniaxial stretching. In addition, the substrate film and the resin layer can be uniaxially stretched in the TD direction (direction perpendicular to the film conveyance direction). In this case, the so-called tenter method can be used. In addition, the stretching of the substrate film and the resin layer can be dry stretching performed in the atmosphere, or wet stretching performed in a state where the resin layer is swollen with a solvent. In order to exhibit the performance of the polarizer, the stretching ratio is 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. The upper limit of the stretching ratio is not particularly limited, but from the viewpoint of suppressing breakage, etc., it is preferably 8 times or less.

[0125] The polarizer produced by the above method can be obtained by peeling off the substrate film after laminating the following protective layer. According to this method, further thinning of the polarizer can be achieved.

[0126] As a method for manufacturing a polarizer which is a cured film obtained by aligning a dichroic pigment in a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound, the following method can be cited. That is, a polarizer-forming composition containing a polymerizable liquid crystal compound and a dichroic pigment is coated on a substrate film, and the polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state unchanged to be cured, thereby forming a polarizer. The polarizer obtained as described above is in a state of being laminated on the substrate film, and the polarizer with the substrate film can be used as an optical film. Alternatively, after laminating the polarizer with the substrate film and a liquid crystal layer laminate with a first adhesive cured layer interposed therebetween, the substrate film can be peeled off, and the polarizer can be used as an optical film.

[0127] As the dichroic pigment, a pigment having the property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction can be used. For example, a pigment having an absorption maximum wavelength (λmax) in the range of 300 to 700 nm is preferred. As such a dichroic pigment, for example, acridine pigments, oxazine pigments, cyanine pigments, naphthalene pigments, azo pigments, anthraquinone pigments, etc. can be cited, and among them, azo pigments are preferred. As azo pigments, monoazo pigments, bisazo pigments, trisazo pigments, tetrakisazo pigments, stilbene azo pigments, etc. can be cited, and bisazo pigments and trisazo pigments are more preferred.

[0128] The polarizer-forming composition may contain a solvent, a polymerization initiator such as a photoinitiator, a photosensitizer, a polymerization inhibitor, etc. For the polymerizable liquid crystal compound, dichroic pigment, solvent, polymerization initiator, photosensitizer, polymerization inhibitor, etc. contained in the polarizer-forming composition, known substances can be used. For example, the substances exemplified in JP-A-2017-102479 and JP-A-2017-83843 can be used. In addition, the polymerizable liquid crystal compound can be the same compound as the compounds exemplified for the polymerizable liquid crystal compound used to obtain the first liquid crystal layer and the second liquid crystal layer described later. For the method of forming a polarizer using the polarizer-forming composition, the methods exemplified in the above-mentioned publications can also be adopted.

[0129] The thickness of the polarizer is preferably 2 μm or more, more preferably 3 μm or more. In addition, the thickness of the polarizer is 25 μm or less, preferably 15 μm or less, more preferably 13 μm or less, and further preferably 7 μm or less. It should be noted that the above upper limit value and lower limit value can be arbitrarily combined. The thinner the thickness of the polarizer, the smaller the rigidity and the more easily it is affected by the shrinkage stress of the first liquid crystal layer and the second liquid crystal layer. Therefore, when using a polarizer with a small thickness as an optical film, the manufacturing methods of the optical laminate and the optical laminate with an adhesive layer of the above-described embodiments can be suitably used.

[0130] (Polarizing plate)

[0131] A polarizing plate can be formed by laminating a protective layer with a known adhesive layer or bonding layer on one or both sides of a polarizer. This polarizing plate is a so-called linear polarizing plate. As the protective layer that can be laminated on one or both sides of the polarizer, for example, a film formed of a thermoplastic resin with excellent transparency, mechanical strength, thermal stability, water resistance, isotropy, stretchability, etc. can be used.

[0132] Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; polyamide resins such as nylon or aromatic polyamide; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; cyclic polyolefin resins having a ring system and a norbornene structure (also called norbornene-based resins); (meth)acrylic resins; polyarylate resins; polystyrene resins; polyvinyl alcohol resins, and mixtures thereof. When protective layers are laminated on both sides of the polarizer, the resin compositions of the two protective layers can be the same or different. The manufacturing method of the optical laminate with an adhesive layer according to the above-described embodiment is preferable because it can suppress anti-curling even when a polarizing plate having a protective layer laminated only on one side of the polarizer is used as the optical film from the viewpoint of thinning. It should be noted that in this specification, the so-called “(meth)acrylic” means that it can be either acrylic or methacrylic. The “(meth)” in (meth)acrylate, etc. has the same meaning.

[0133] In order to improve the adhesion with a polarizer containing a PVA-based resin and a dichroic substance, the film formed of a thermoplastic resin can be subjected to surface treatment (such as corona treatment, etc.) or a thin layer such as a primer layer (also called a base coat layer) can be formed.

[0134] The protective layer preferably has a moisture permeability of 1 to 1500 g / m 2 ·24 h at a temperature of 40 °C and a humidity of 90% RH. If the moisture permeability of the protective layer is greater than 1500 g / m 2 ·24 h, in a high-temperature and high-humidity environment, there is a case where curling changes of the polarizing plate over time are likely to occur. The lower the moisture permeability of the protective layer, the more easily the effect of suppressing the curling change of the polarizing plate over time can be obtained. The moisture permeability of the protective layer at a temperature of 40 °C and a humidity of 90% RH is more preferably 1000 g / m 2 ·24 h or less, further preferably 100 g / m 2 ·24 h or less, and even more preferably 10 g / m 2 ·24 h or less. The moisture permeability can be measured in accordance with JIS Z 0208:1976.

[0135] It should be noted that in the case where protective layers are laminated on both sides of the polarizing plate, it is preferable that the moisture permeability of the outer protective layer laminated on the visible side when the optical laminate or the optical laminate with an adhesive layer is adhered to the optical display element is the same as that of the inner protective layer laminated on the first adhesive layer side, or one of the outer protective layers is smaller than the inner protective layer. Thus, especially when moisture is introduced during the storage of the polarizing plate, a flat shape can be maintained, or the inner protective layer can be swollen to make the polarizing plate curl toward the positive curling side, so that it is easy to make the optical laminate or the optical laminate with an adhesive layer curl toward the positive curling side. In addition, the moisture permeability of the outer protective layer is more preferably 10 g / m 2 ·24 hr or less. Thus, even in the case of a polarizing plate having a protective layer laminated on only one side of the polarizing plate, curling can be controlled, and after the optical laminate or the optical laminate with an adhesive layer is adhered to the optical display element, dimensional changes (deformations) over time can also be suppressed.

[0136] Furthermore, in order to further reduce the influence of the shrinkage stress of the first liquid crystal layer and the second liquid crystal layer and suppress the positive curling generated in the optical laminate and the optical laminate with an adhesive layer, in the polarizing plate used as an optical film, it is preferable to increase the rigidity of the protective layer laminated on the polarizing plate. The so-called rigidity here is defined as the value obtained by multiplying the tensile elastic modulus at room temperature (23 °C) (hereinafter sometimes simply referred to as the "23 °C elastic modulus") of the film used in the protective layer by the film thickness. For example, for a protective layer using a cellulose-based polymer represented by triacetyl cellulose, the 23 °C elastic modulus is preferably in the range of 3000 to 5000 MPa, for a protective layer using an acrylic-based polymer represented by polymethyl methacrylate, the 23 °C elastic modulus is preferably in the range of 2000 to 4000 MPa, and for a protective layer using a cycloolefin-based polymer such as having a norbornene structure, the 23 °C elastic modulus is preferably in the range of 2000 to 4000 MPa. In the outer protective layer, an acrylic-based polymer or a polyolefin-based polymer can be suitably used from the viewpoints of the above-mentioned moisture permeability and rigidity, and a cycloolefin-based polymer is particularly preferably used.

[0137] The protective layer can be, for example, a resin obtained by stretching the aforementioned thermoplastic resin, or an unstretched resin (hereinafter sometimes referred to as an "unstretched resin"). Examples of the stretching treatment include uniaxial stretching and biaxial stretching.

[0138] The stretching direction in the stretching process can be the length direction of the unstretched resin, the direction orthogonal to the length direction, or the direction obliquely intersecting with the length direction. In the case of uniaxial stretching, it is only necessary to stretch the unstretched resin along any one of these directions. Biaxial stretching can be simultaneous biaxial stretching in which the resin is stretched simultaneously along two stretching directions among these directions, or sequential biaxial stretching in which the resin is stretched along a given direction first and then along another direction.

[0139] The stretching process can be carried out, for example, by stretching along the length direction using two or more pairs of pinch rolls with an increased circumferential speed on the downstream side, or by holding both ends of the unstretched resin with chucks and stretching it along the direction orthogonal to the length direction. At this time, by adjusting the thickness of the stretched thermoplastic resin or the stretching ratio, the desired phase difference and wavelength dispersion can be controlled.

[0140] The stretched thermoplastic resin preferably satisfies the following formula.

[0141] (1) 80nm ≤ Re(590) ≤ 180nm;

[0142] (2) 0.5 < Rth(590) / Re(590) ≤ 0.8;

[0143] (3) 0.85 ≤ Re(450) / Re(550) < 1.00.

[0144] In the formula, Re(590), Re(450), and Re(550) respectively represent the in-plane phase differences at the measurement wavelengths of 590nm, 450nm, and 550nm, and Rth(590) represents the thickness-direction phase difference at the measurement wavelength of 590nm. These in-plane phase differences and thickness-direction phase differences refer to the values measured in an environment of 23°C and 55% relative humidity.

[0145] When the refractive index in the in-plane slow axis direction is set as nx, the refractive index in the in-plane fast axis direction (the direction orthogonal to the in-plane slow axis direction) is set as ny, the refractive index in the thickness direction is set as nz, and the thickness of the stretched thermoplastic resin is set as d, the in-plane phase difference Re and the thickness-direction phase difference Rth are defined by the following formulas (S1) and (S2).

[0146] (S1) Re = (nx - ny) × d;

[0147] (S2) Rth = [((nx + ny) / 2) - nz] × d.

[0148] The above-mentioned outer protective layer is preferably a stretched thermoplastic resin satisfying the above formulas (1) to (3). In addition, the above-mentioned outer protective layer is preferably adhered to the polarizing plate in such a manner that the slow axis is in a direction obliquely intersecting the absorption axis of the polarizing plate. For example, it is preferably adhered in such a manner that the angle of the slow axis of the outer protective layer with respect to the absorption axis of the polarizing plate is 45 ± 10° or 135 ± 10°. By setting the angle of the slow axis within the above range, a difference is generated between the phase of light in the fast axis direction and the phase of light in the slow axis direction. Therefore, if the optical laminate of the present embodiment is applied to an optical display element, the light emitted through the optical laminate can be circularly polarized light. Thus, a display device using the optical laminate of the present embodiment as an optical display element can provide a display image with excellent visibility even when viewing a display image through polarized sunglasses or the like.

[0149] The thickness of the protective layer is preferably 3 μm or more, more preferably 5 μm or more. In addition, the thickness of the protective layer is preferably 50 μm or less, more preferably 30 μm or less. It should be noted that the above upper limit value and lower limit value can be arbitrarily combined. Since the thinner the thickness of the polarizing plate, the smaller the rigidity and the more easily it is affected by the shrinkage stress of the first liquid crystal layer and the second liquid crystal layer, when a polarizing plate with a small thickness is used as an optical film, the manufacturing method of the optical laminate of the above embodiment and the manufacturing method of the optical laminate with an adhesive layer can be suitably used.

[0150] The surface on the side opposite to the polarizing plate of the protective layer may have a surface treatment layer. For example, it may have a hard coat layer, an antireflection layer, an anti-adhesion layer, an antiglare layer, a diffusion layer, etc. The surface treatment layer may be another layer laminated on the protective layer, or may be a layer formed by performing a surface treatment on the surface of the protective layer.

[0151] The hard coat layer is a layer for preventing damage to the surface of the polarizing plate, etc. For example, it can be formed by applying a cured film with excellent hardness, sliding properties, etc. of an ultraviolet curable resin such as an acrylic-based or silicone-based resin to the surface of the protective layer. The antireflection layer is a layer for preventing reflection of external light on the surface of the polarizing plate, and can be realized by forming an antireflection film according to a conventional method. In addition, the anti-adhesion layer is a layer for preventing adhesion to an adjacent layer.

[0152] The antiglare layer is a layer aimed at preventing the recognition of the transmitted light of the polarizing plate from being hindered by the reflection of external light on the surface of the polarizing plate. For example, it can be formed by imparting a fine concavo-convex structure to the surface of the protective layer by means of a roughening method based on sandblasting or embossing, or a method of blending transparent fine particles. As the transparent fine particles used for imparting a fine concavo-convex structure to the surface of the protective layer, for example, inorganic fine particles such as silica, alumina, titanium dioxide, zirconium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide having a conductivity with an average particle size of 0.5 to 50 μm, and organic fine particles such as crosslinked or uncrosslinked polymers can be cited. The content of the transparent fine particles is generally 2 to 50 parts by mass, preferably 5 to 25 parts by mass, based on 100 parts by mass of the resin for forming the layer having the fine concavo-convex structure. The antiglare layer can also serve as a diffusion layer (such as a viewing angle expansion function) for diffusing the transmitted light of the diffusion polarizing plate and expanding the viewing angle, etc.

[0153] In the case where the surface treatment layer is another layer laminated on the protective layer of the polarizing plate, the thickness of the surface treatment layer is preferably 0.5 μm or more, more preferably 1 μm or more. In addition, it is preferably 10 μm or less, more preferably 8 μm or less. If the thickness is less than 0.5 μm, there is a tendency that it is difficult to effectively prevent damage to the surface of the polarizing plate. In addition, if the thickness is greater than 10 μm, there is a case where it is difficult to suppress the reverse curling of the polarizing plate due to a large curing shrinkage or the like.

[0154] The manufacturing method of the optical laminate with an adhesive layer according to the above embodiment is suitable for the case where the thickness of the polarizing plate is 2 μm or more and 300 μm or less. The thickness of the polarizing plate can also be 10 μm or more, and can also be 150 μm or less, can also be 120 μm or less, and can also be 80 μm or less.

[0155] The measured MD curl value and the measured TD curl value of the polarizing plate obtained by peeling off the protective film from the polarizing plate with a protective film measured by the method described in the following examples are preferably independently in the range of -40 mm or more and 40 mm or less, more preferably in the range of -30 mm or more and 35 mm or less, and further preferably in the range of -20 mm or more and 30 mm or less. If the above-mentioned measured MD curl value and measured TD curl value are outside the above range, the polarizing plate has a tendency to easily become cylindrical and has a tendency to be difficult to obtain a curled shape. In addition, if the measured MD curl value and measured TD curl value of the polarizing plate with a protective film described below deviate from the measured MD curl value and measured TD curl value of the polarizing plate, warping occurs between the protective film and the polarizing plate, or a tunneling phenomenon where a gap is generated between the protective film and the polarizing plate, which is not preferable.

[0156] (Polarizing plate with protective film)

[0157] A protective film is usually laminated on one side of a polarizing plate, and thus a polarizing plate with a protective film can be produced. The protective film includes a resin film for the protective film and an adhesive layer for the protective film laminated thereon. The thickness of the protective film can be, for example, 30 to 200 μm, preferably 40 to 150 μm, and more preferably 50 to 120 μm.

[0158] Examples of the resin constituting the resin film for the protective film include polyolefin resins such as polyethylene-based resins and polypropylene-based resins; cyclic olefin-based resins; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate-based resins; (meth)acrylic resins, etc. Among them, polyester-based resins such as polyethylene terephthalate are preferred. The resin film for the protective film can have a single-layer structure or a multilayer structure with two or more layers.

[0159] As the adhesive constituting the adhesive layer for the protective film, the same adhesive as the adhesive constituting the adhesive layer described later can be used. In addition, the protective film can be obtained by coating an adhesive composition on the surface of the resin film for the protective film and drying it, etc., to form an adhesive layer. If necessary, for the adhesive coating surface of the resin film for the protective film, in order to improve the adhesion, surface treatment (such as corona treatment, etc.) can be carried out, or a thin layer such as a primer layer (also called a base coat layer) can be formed. In addition, if necessary, a release layer for protecting the surface on the side opposite to the resin film for the protective film of the adhesive layer for the protective film by covering can be provided. This release layer can be peeled off at an appropriate timing when laminating with the polarizing plate.

[0160] In the manufacturing process of a polarizing plate with a protective film, which is a polarizing plate with a protective film laminated thereon, positive curling can also be imparted in the longitudinal direction of the polarizing plate with a protective film by imparting a tension difference and a circumferential speed difference. Therefore, in the manufacturing method of the optical laminate with an adhesive layer in the above-described embodiment, when using a polarizing plate with a protective film as the optical film, by imparting positive curling to the polarizing plate with a protective film in the manufacturing process of the polarizing plate with a protective film, it can be expected that it is easier to suppress the reverse curling of the optical laminate and the optical laminate with an adhesive layer.

[0161] The polarization plate with a protective film preferably has the measured MD curl value and the measured TD curl value of the polarization plate with a protective film measured by the method described in the following examples independently in the range of -40 mm or more and 40 mm or less, more preferably in the range of -30 mm or more and 35 mm or less, and further preferably in the range of -20 mm or more and 30 mm or less. If the above-mentioned measured MD curl value and measured TD curl value are outside the above range, the polarization plate with a protective film tends to easily become cylindrical and has a tendency to be difficult to obtain a curled shape. In addition, when the polarization plate with a protective film is processed into a given size and attached to an optical display element, it is difficult to properly hold it by the suction mechanism of the attaching device, etc., and there is a tendency to mix in air bubbles or generate wrinkles during attachment, so it is not preferred.

[0162] Since the thinner the thickness of the polarization plate with a protective film, the smaller the rigidity and the more easily it is affected by the shrinkage stress of the first liquid crystal layer and the second liquid crystal layer, therefore, when using a polarization plate with a small thickness as an optical film, the manufacturing method of the optical laminate of the above embodiment and the manufacturing method of the optical laminate with an adhesive layer can be suitably used. When the optical film 60 in the above embodiment is a polarization plate with a protective film, the manufacturing method of the optical laminate with an adhesive layer of the above embodiment is suitable for the case where the thickness of the polarization plate with a protective film is 32 μm or more and 500 μm or less. The thickness of the polarization plate with a protective film can also be 40 μm or more, and can also be 350 μm or less, can also be 200 μm or less, and can also be 150 μm or less.

[0163] (Adhesive layer)

[0164] The adhesive layer refers to a layer composed of an adhesive. In this specification, the so-called "adhesive" is a soft rubber-like substance that exhibits adhesiveness by adhering itself to an adherend such as an optical film or a liquid crystal layer, and is a substance called a so-called pressure-sensitive adhesive. In addition, the active energy ray-curable adhesive described later can adjust the crosslinking degree and adhesive force by irradiating energy rays.

[0165] As the adhesive, an adhesive known in the past and having excellent optical transparency can be used without particular limitation. For example, an adhesive having a base polymer such as an acrylic-based, urethane-based, silicone-based, or polyvinyl ether-based polymer can be used. In addition, it can also be an active energy ray-curable adhesive, a thermosetting adhesive, etc. Among them, an adhesive having an acrylic resin excellent in transparency, adhesive force, re-peelability (hereinafter also referred to as reprocessability), weather resistance, heat resistance, etc. as a base polymer is suitable. The adhesive layer preferably consists of a reaction product of an adhesive composition containing (meth)acrylic resin (1), a crosslinking agent (2), and a silane compound (3), and may also contain other components (4).

[0166] ((Meth)acrylic resin (1))

[0167] The (meth)acrylic resin (1) contained in the adhesive composition is preferably a polymer (hereinafter also referred to as a “(meth)acrylate polymer”) having as a main component a structural unit derived from a (meth)acrylic acid alkyl ester represented by the following formula (I) (hereinafter also referred to as “structural unit (I)”) (for example, containing 50% by mass or more of this structural unit). In the present specification, the so-called “derived from” means that the chemical structure of a compound such as a (meth)acrylic acid alkyl ester changes due to polymerization.

[0168] [Chemical formula 1]

[0169]

[0170] [In the formula, R 10 represents a hydrogen atom or a methyl group, and R 20 represents an alkyl group having 1 to 20 carbon atoms, and the alkyl group may have any one of a linear, branched or cyclic structure, and a hydrogen atom of the alkyl group may be substituted with an alkoxy group having 1 to 10 carbon atoms.]

[0171] Examples of the (meth)acrylate represented by formula (I) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n- and iso-nonyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, tert-butyl (meth)acrylate, etc. Specific examples of the acrylic acid alkyl ester containing an alkoxy group include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, etc. Among them, n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate is preferably contained, and n-butyl (meth)acrylate is particularly preferably contained.

[0172] The (meth)acrylate polymer may contain a structural unit derived from a monomer other than the structural unit (I). The structural unit derived from other monomers may be one kind or two or more kinds. Examples of other monomers that the (meth)acrylate polymer can contain include monomers having a polar functional group, monomers having an aromatic group, and acrylamide-based monomers.

[0173] Examples of the monomer having a polar functional group include (meth)acrylate having a polar functional group. Examples of the polar functional group include a hydroxyl group, a carboxyl group, a substituted amino group, an unsubstituted amino group, etc. Examples of the polar functional group also include a heterocyclic group such as an epoxy group, etc.

[0174] The content of the structural unit derived from the monomer having a polar functional group in the (meth)acrylate polymer is preferably 20 parts by mass or less, more preferably 0.1 part by mass or more and 20 parts by mass or less, still more preferably 0.1 part by mass or more and 10 parts by mass or less, and particularly preferably 0.5 part by mass or more and 10 parts by mass or less, relative to 100 parts by mass of all the structural units of the (meth)acrylate polymer.

[0175] Examples of the monomer having an aromatic group include (meth)acrylate having 1 (meth)acryloyl group and 1 or more aromatic rings (such as a benzene ring, a naphthalene ring, etc.) in the molecule and having a phenyl group, a phenoxyethyl group, or a benzyl group.

[0176] The content of the structural unit derived from the monomer having an aromatic group in the (meth)acrylate polymer is preferably 50 parts by mass or less, more preferably 4 parts by mass or more and 50 parts by mass or less, still more preferably 4 parts by mass or more and 25 parts by mass or less, relative to 100 parts by mass of all the structural units of the (meth)acrylate polymer.

[0177] Examples of the acrylamide-based monomer include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide, etc. By including these structural units, the bleeding of additives such as the antistatic interfering agent described later can be suppressed.

[0178] In addition, as the structural unit derived from other monomers other than the structural unit (I), a structural unit derived from a styrene-based monomer, a structural unit derived from a vinyl-based monomer, a structural unit derived from a monomer having a plurality of (meth)acryloyl groups in the molecule, etc. may be included.

[0179] The weight-average molecular weight of the (meth)acrylic resin (1) (hereinafter also simply referred to as "Mw") is preferably 500,000 to 2,500,000. If the weight-average molecular weight is 500,000 or more, the durability of the adhesive layer in a high-temperature and high-humidity environment can be improved. If the weight-average molecular weight is 2,500,000 or less, the operability during coating of the coating liquid containing the adhesive composition becomes good. The molecular weight distribution (Mw / Mn) expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (hereinafter also simply referred to as "Mn") is usually 2 to 10. In this specification, the so-called "weight-average molecular weight" and "number-average molecular weight" are polystyrene conversion values measured by gel permeation chromatography (GPC).

[0180] When dissolving the (meth)acrylic resin (1) in ethyl acetate to prepare a 20 mass% solution, the viscosity at 25 °C is preferably 20 Pa·s or less, more preferably 0.1 to 15 Pa·s. If the viscosity of the (meth)acrylic resin (1) at 25 °C is within the above range, it contributes to reprocessability and the like. The above viscosity can be measured using a Brookfield viscometer.

[0181] From the viewpoint of balancing adhesiveness and durability, the glass transition temperature of the (meth)acrylic resin (1) is preferably -10 °C to -60 °C. It should be noted that the glass transition temperature can be measured using a differential scanning calorimeter (DSC).

[0182] The (meth)acrylic resin (1) may contain two or more (meth)acrylate polymers. As such a (meth)acrylate polymer, for example, a (meth)acrylate polymer having a relatively low molecular weight with a structural unit (I) derived from the (meth)acrylate as the main component and a weight-average molecular weight in the range of 50,000 to 300,000 can be cited.

[0183] (Crosslinking agent (2))

[0184] The adhesive composition for forming the adhesive layer preferably contains a crosslinking agent (2). As the crosslinking agent (2), conventional crosslinking agents (such as isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.) can be cited. In particular, from the viewpoints of the pot life, crosslinking speed, etc. of the adhesive composition, isocyanate-based compounds are preferred.

[0185] As an isocyanate compound, a compound having at least two isocyanate groups (-NCO) in the molecule is preferred. For example, aliphatic isocyanate compounds (such as hexamethylene diisocyanate, etc.), alicyclic isocyanate compounds (such as isophorone diisocyanate), hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, aromatic isocyanate compounds (such as toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.) can be cited. In addition, the crosslinking agent (2) can also be an adduct (addition compound) of the above isocyanate compound with a polyol compound [such as an adduct using glycerol, trimethylolpropane, etc.], an isocyanurate compound, a biuret type compound, a urethane prepolymer type isocyanate compound obtained by an addition reaction with a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc. The crosslinking agent (2) can be used alone or in combination of two or more. Among them, from the viewpoint of durability, toluene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate and their polyol compounds or their isocyanurate compounds are preferred.

[0186] The proportion of the crosslinking agent (2) relative to 100 parts by mass of the (meth)acrylic resin (1) can be, for example, 0.01 to 10 parts by mass, preferably 0.1 to 3 parts by mass, and more preferably 0.1 to 1 part by mass. If it is below the above upper limit value, it is beneficial to improve durability. If it is above the above lower limit value, the generation of gas is suppressed, which is beneficial to improve reprocessability.

[0187] (Silane compound (3))

[0188] The adhesive composition contains a silane compound (3). By containing the silane compound (3), the adhesion between the adhesive layer and the laminated layer can be improved. Two or more silane compounds (3) can also be used.

[0189] As the silane compound (3), for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethyldimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc. can be cited.

[0190] In addition, the silane compound (3) can contain oligomers derived from the above silane compound (3).

[0191] The content of the silane compound (3) in the adhesive composition is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, and further preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the (meth)acrylic resin (1). If the content of the silane compound (3) is 0.01 part by mass or more, it is easy to improve the adhesion between the adhesive layer and adherends such as an optical film and a liquid crystal layer. If the content is 10 parts by mass or less, bleeding of the silane compound (3) from the adhesive layer can be suppressed.

[0192] (Other components (4))

[0193] In the adhesive composition for forming the adhesive layer, as the other component (4), one or more additives such as an antistatic interference agent using an ionic compound, a solvent, a crosslinking catalyst, a tackifying resin (tackifier), a plasticizer, a weather resistance stabilizer, a softening agent, a dye, a pigment, an inorganic filler, and a resin other than an acrylic resin can be included.

[0194] (Reactive energy ray curable adhesive)

[0195] It is also useful to incorporate a polyfunctional acrylate or other ultraviolet curable compound into the adhesive composition and irradiate it with ultraviolet rays after forming the adhesive layer to cure it to form a harder adhesive layer. A reactive energy ray curable adhesive can be used. The "reactive energy ray curable adhesive" has the property of being cured by irradiation with energy rays such as ultraviolet rays and electron beams. A reactive energy ray curable adhesive is an adhesive having the following properties: since it also has adhesiveness before irradiation with energy rays, it can adhere to adherends such as an optical film and a liquid crystal layer, and the adhesion force can be adjusted by curing by irradiation with energy rays.

[0196] The reactive energy ray curable adhesive generally contains an acrylic adhesive and an energy ray polymerizable compound as main components. A crosslinking agent is usually also incorporated, and a photoinitiator, a photosensitizer, etc. can be incorporated as needed.

[0197] The adhesive layer preferably has a storage modulus of 0.10 to 10.0 MPa at 23°C, more preferably 0.15 to 5.0 MPa. If the storage modulus at 23°C is 0.10 MPa or more, poor conditions such as peeling can be suppressed when a temperature change occurs, so it is preferred. In addition, if it is 10.0 MPa or less, a decrease in durability due to a decrease in adhesive force is less likely to occur, so it is preferred. It should be noted that the storage modulus of the adhesive layer can be measured using a commercially available viscoelasticity measuring device, such as the viscoelasticity measuring device "DYNAMIC ANALYZER RDA II" manufactured by REOMETRIC.

[0198] The thickness of the adhesive layer is preferably 3 μm or more, more preferably 5 μm or more. In addition, the thickness of the adhesive layer is preferably 40 μm or less, more preferably 30 μm or less. It should be noted that the above upper limit value and lower limit value can be arbitrarily combined.

[0199] (Adhesive cured layer)

[0200] The first adhesive cured layer and the second adhesive cured layer (hereinafter sometimes collectively referred to as the "adhesive cured layer") refer to the layers formed by curing the curable components in the adhesive composition. As the adhesive composition for forming the adhesive cured layer, it is an adhesive other than a pressure-sensitive adhesive, and examples thereof include an aqueous adhesive and a radiation-curable adhesive. As the aqueous adhesive, for example, an adhesive in which a polyvinyl alcohol-based resin is dissolved or dispersed in water can be cited. As the radiation-curable adhesive, for example, a solvent-free radiation-curable adhesive containing a curable compound that is cured by irradiation with radiation such as ultraviolet rays, visible light, electron beams, or X-rays can be cited. By using a solvent-free radiation-curable adhesive, the interlayer adhesion can be improved. In contrast, if the radiation-curable adhesive contains a solvent (especially an organic solvent), even if the curable components contained in the adhesive are the same, sufficient adhesion cannot be obtained, and when the optical laminate is cut into a given size, poor conditions such as peeling at its end are likely to occur. In addition, since an additional step of drying the solvent is added, additional shrinkage stress caused by heat is received, and reverse curling is likely to occur in the optical laminate and the optical laminate with an adhesive layer.

[0201] When a solvent-free radiation-curable adhesive containing a curable compound that is cured by irradiation with radiation is used, the rigidity obtained by multiplying the storage modulus, which is an index representing the hardness of the cured radiation-curable adhesive, by the thickness is often higher than that of the cured aqueous adhesive. If the rigidity of the adhesive cured layer provided between the first liquid crystal layer and the second liquid crystal layer is high, curling caused by shrinkage stress during peeling from the substrate can be prevented, so it is preferable to use a radiation-curable adhesive.

[0202] As the radiation-curable adhesive, since it exhibits good adhesiveness, it preferably contains either or both of a cationically polymerizable curable compound and a free-radically polymerizable curable compound. The radiation-curable adhesive may further contain a cationic polymerization initiator or a free-radical polymerization initiator for initiating the curing reaction of the above curable compound.

[0203] Examples of the cationically polymerizable curable compound include epoxy compounds (compounds having one or more epoxy groups in the molecule), oxetane compounds (compounds having one or more oxetane rings in the molecule), or combinations thereof.

[0204] Examples of the radically polymerizable curable compound include (meth)acrylic compounds (compounds having one or more (meth)acryloyloxy groups in the molecule), other vinyl compounds having a radically polymerizable double bond, or combinations thereof.

[0205] The active energy ray curable adhesive may contain a sensitizer as needed. By using a sensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the adhesive layer can be further improved. As the sensitizer, a known sensitizer can be appropriately used. When the sensitizer is blended, the blending amount is preferably in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the active energy ray curable adhesive.

[0206] The active energy ray curable adhesive may contain additives such as an ion scavenger, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, an antifoaming agent, an antistatic interference agent, a leveling agent, and a solvent as needed.

[0207] An adhesive composition layer can be formed by applying the adhesive composition to the bonding surfaces of the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer. As the coating method, a usual coating technique using a die slit coater, a comma coater, a reverse roll coater, a trough roll coater, a rod coater, a wire bar coater, a blade coater, an air knife coater, etc. can be adopted.

[0208] The drying method for using an aqueous adhesive is not particularly limited. For example, a method of drying using a hot air dryer or an infrared dryer can be adopted.

[0209] In the case of using an active energy ray curable adhesive, active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays can be irradiated to cure the adhesive composition layer to form an adhesive cured layer. As the active energy ray, ultraviolet rays are preferred, and as the light source at this time, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, a black light, a microwave-excited mercury lamp, a metal halide lamp, etc. can be used.

[0210] In the case of curing the adhesive composition layer by ultraviolet irradiation, the light irradiation intensity of the ultraviolet rays is determined according to the composition of the adhesive composition and is not particularly limited, but is preferably 10 to 1000 mW / cm 2, more preferably 100 to 600 mW / cm 2 . If the light irradiation intensity of the resin composition is less than 10 mW / cm 2 , the reaction time is too long. If it is greater than 1000 mW / cm 2 , yellowing may occur in the obtained adhesive cured layer due to the heat radiated from the light source and the heat generated during the polymerization of the adhesive composition. In addition, greater shrinkage stress may be generated due to the heat radiated from the light source. The irradiation intensity is the intensity in the wavelength region effective for activating the polymerization initiator, preferably the photo cationic polymerization initiator. More preferably, it is the intensity in the wavelength region of 400 nm or less, and further preferably the intensity in the wavelength region of 280 to 320 nm. It is preferably irradiated once or more times with this light irradiation intensity so that the cumulative light amount is 10 mJ / cm 2 or more, preferably 100 to 1000 mJ / cm 2 , more preferably 200 to 600 mJ / cm 2 is set in such a manner. If the cumulative light amount of the adhesive composition layer is less than 10 mJ / cm 2 , the generation of active species from the polymerization initiator is not sufficient, and the curing of the adhesive composition layer is not sufficient. If the cumulative light amount is greater than 1000 mJ / cm 2 , the irradiation time becomes very long, which is not conducive to improving productivity. In addition, greater shrinkage stress may be generated due to the heat radiated from the light source. Depending on the types of the first substrate layer, the second substrate layer, the first liquid crystal layer, the second liquid crystal layer, etc., and the combination of the components in the adhesive composition, etc., the wavelengths (UVA (320 to 390 nm), UVB (280 to 320 nm), etc.) during light irradiation are different, and the required cumulative light amount also changes according to the wavelength during light irradiation.

[0211] As the viscosity of the energy ray curable adhesive, it can be selected as long as it can be coated by any coating method. However, the viscosity at 25°C is preferably in the range of 10 to 1000 mPa·sec, and more preferably in the range of 20 to 500 mPa·sec. If the viscosity is too small, there is a tendency that it is difficult to form an adhesive cured layer with a desired thickness. On the other hand, if the viscosity is too large, the energy ray curable adhesive is difficult to flow during coating, and there is a tendency that it is difficult to obtain a uniform coating film without unevenness. The viscosity mentioned here is the value measured with an E-type viscometer at 10 rps after adjusting the temperature of the adhesive to 25°C.

[0212] Regarding the storage modulus of the adhesive cured layer at a temperature of 30°C, from the viewpoints of the durability of the polarizing plate as an optical film and suppression of reverse curling, it is preferably 100 MPa or more, more preferably 1000 MPa or more, further preferably 1500 MPa or more, and particularly preferably 2000 MPa or more. On the other hand, if the storage modulus of the adhesive cured layer is too large, the adhesive cured layer becomes too hard, and the processability during blanking processing or the like for making the optical laminate with an adhesive layer into a given size will decrease. Therefore, the storage modulus of the adhesive cured layer at a temperature of 30°C is preferably 10000 MPa or less, more preferably 8000 MPa or less, and further preferably 5000 MPa or less.

[0213] The storage modulus of the adhesive cured layer at a temperature of 30°C can be calculated by the following steps. On one side of a cyclic polyolefin resin film with a thickness of 50 μm, the above-mentioned active energy ray-curable adhesive is coated using a coater (bar coater, manufactured by Daiichi Rika Co., Ltd.), and a cyclic polyolefin resin film with a thickness of 50 μm is laminated on the coated surface. Then, using the "D lamp tube" manufactured by FUSION UV SYSTEMS, ultraviolet rays are irradiated in such a way that the cumulative light amount is 1500 mJ / cm 2 (UVB) to cure the adhesive composition layer. It is cut into a size of 5 mm × 30 mm, and one cyclic polyolefin resin film is peeled off to obtain an adhesive cured layer with a resin film. The adhesive cured layer with the resin film is held by a dynamic viscoelasticity measuring device "DVA-220" manufactured by IT Measurement Control Co., Ltd. with a clamp interval of 2 cm in such a way that its long side is in the pulling direction, the frequencies of pulling and contraction are set to 10 Hz, and the temperature is raised at a rate of 10°C / minute to obtain the storage modulus at a temperature of 30°C.

[0214] The thickness of the adhesive cured layer is preferably 10 μm or less, more preferably 5 μm or less, and further preferably 2 μm or less. In addition, it is preferably 0.1 μm or more, more preferably 0.5 μm or more, and further preferably 1 μm or more. By making the thickness of the adhesive cured layer above the lower limit value, the rigidity becomes higher, and the curling suppression effect of the optical laminate and the optical laminate with an adhesive layer can be improved. On the other hand, by setting the thickness of the adhesive cured layer within the upper limit value, coating defects such as the mixing of air bubbles can be prevented.

[0215] (Adhesive layer with a release layer)

[0216] The adhesive layer with a release layer can be obtained, for example, by coating an adhesive composition on the demolding surface of the release layer and drying it to form the adhesive layer. The adhesive layer with a release layer may also have, if necessary, another release layer on the surface opposite to the release layer side for protecting the adhesive layer by covering. The release layer and the other release layer can be peeled off at an appropriate time.

[0217] (Release layer)

[0218] The release layer can be peeled off relative to the adhesive layer and has the functions of supporting the adhesive layer formed on the release layer and protecting the adhesive layer. As the release layer, known release films or release papers can be used. For example, it can be a layer obtained by performing a demolding treatment such as silicone coating on a film formed of a resin material, which is exemplified as a base material layer hereinafter. For the other release layer, the same material as the release layer can also be used.

[0219] The release layer can be peeled off relative to the adhesive layer, and the magnitude of the peeling force between the release layer and the adhesive layer needs to be determined in consideration of the order of peeling the release layer. For the above-mentioned peeling force, a test piece for measurement having an adhesive layer on the release layer (sized 200 mm in length and 25 mm in width) can be prepared, attached to a glass of an appropriate size, and using a universal testing machine (AGS-50NX) manufactured by Shimadzu Corporation, the release layer and the glass that have been partially peeled off to form a peeling starting point are respectively clamped, and the release layer is peeled off in a 180° direction at a speed of 300 mm / minute. The peeling strength measured at this time is set as the peeling force. The peeling force between the release layer and the adhesive layer is preferably 0.01 - 0.20 N / 25 mm, more preferably 0.02 - 0.10 N / 25 mm, and further preferably 0.02 - 0.06 N / 25 mm. If it is less than 0.01 N / 25 mm, warping may occur between the release layer and the adhesive layer during transportation. In addition, if it is greater than 0.20 N / 25 mm, the adhesion between the release layer and the adhesive layer is high, and the release layer becomes difficult to peel off from the adhesive layer. Therefore, it may result in a state where the adhesive layer breaks when the release layer is peeled off and a part of the adhesive layer adheres to the peeled release layer, or unexpected peeling between layers (for example, peeling between the layer joined to the side of the adhesive layer opposite to the release layer and the adhesive layer).

[0220] (Liquid crystal layer)

[0221] The first liquid crystal layer and the second liquid crystal layer (hereinafter sometimes referred to as "liquid crystal layer" together) are cured layers formed by polymerizing a polymerizable liquid crystal compound and can be retardation layers. The optical properties of the liquid crystal layer can be adjusted by using the orientation state of the polymerizable liquid crystal compound.

[0222] In this specification, the case where the optical axis of the polymerizable liquid crystal compound is horizontally oriented with respect to the plane of the substrate layer is defined as horizontal orientation, and the case where the optical axis of the polymerizable liquid crystal compound is vertically oriented with respect to the plane of the substrate layer is defined as vertical orientation. The optical axis means the direction in which the cross-section cut out in the direction orthogonal to the optical axis in the refractive index ellipsoid formed by the orientation of the polymerizable liquid crystal compound is a circle, that is, the direction in which the refractive indices in two directions are equal.

[0223] Examples of the polymerizable liquid crystal compound include rod-shaped polymerizable liquid crystal compounds and disc-shaped polymerizable liquid crystal compounds. When a rod-shaped polymerizable liquid crystal compound is horizontally or vertically oriented with respect to the substrate layer, the optical axis of the polymerizable liquid crystal compound coincides with the major axis direction of the polymerizable liquid crystal compound. When a disc-shaped polymerizable liquid crystal compound is oriented, the optical axis of the polymerizable liquid crystal compound exists in the direction orthogonal to the disc plane of the polymerizable liquid crystal compound.

[0224] In order to make the liquid crystal layer formed by polymerizing the polymerizable liquid crystal compound exhibit an in-plane retardation, it is only necessary to orient the polymerizable liquid crystal compound in an appropriate direction. When the polymerizable liquid crystal compound is rod-shaped, the in-plane retardation is exhibited by horizontally orienting the optical axis of the polymerizable liquid crystal compound with respect to the plane of the substrate layer. In this case, the optical axis direction coincides with the slow axis direction. When the polymerizable liquid crystal compound is disc-shaped, the in-plane retardation is exhibited by horizontally orienting the optical axis of the polymerizable liquid crystal compound with respect to the plane of the substrate layer. In this case, the optical axis is orthogonal to the slow axis. The orientation state of the polymerizable liquid crystal compound can be adjusted by using a combination of an alignment film and the polymerizable liquid crystal compound.

[0225] A polymerizable liquid crystal compound is a compound having a polymerizable group and having liquid crystallinity. The polymerizable group means a group participating in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group means a group that can participate in a polymerization reaction due to active radicals, acids, etc. generated from a photopolymerization initiator described later. Examples of the polymerizable group include vinyl, vinyloxy, 1-chloroethenyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, epoxyethyl, oxetanyl, etc. Among them, acryloyloxy, methacryloyloxy, vinyloxy, epoxyethyl, and oxetanyl are preferred, and acryloyloxy is more preferred. The liquid crystallinity possessed by the polymerizable liquid crystal compound can be thermotropic liquid crystal or lyotropic liquid crystal. If the thermotropic liquid crystal is classified by the degree of order, it can be nematic liquid crystal or smectic liquid crystal.

[0226] As the rod-shaped polymeric liquid crystal compound and the discotic polymeric liquid crystal compound, known compounds can be used. For example, the compounds exemplified in JP-A-2015-163937, JP-A-2016-42185, WO2016 / 158940, and JP-A-2016-224128 can be used.

[0227] The liquid crystal layer may have a single-layer structure or a multi-layer structure of two or more layers. In the case of having a multi-layer structure of two or more layers, when preparing the liquid crystal layer with a substrate layer described later, it is only necessary to form a multi-layer structure of two or more layers on the substrate layer. In the case where the liquid crystal layer has a single-layer structure, the thickness of the liquid crystal layer is preferably 0.3 μm or more, may be 1 μm or more, and is usually 10 μm or less, preferably 5 μm or less. In the case where the liquid crystal layer has a multi-layer structure of two or more layers, the thickness of the liquid crystal layer is preferably 0.5 μm or more, may be 1 μm or more, and is usually 10 μm or less, preferably 5 μm or less. From the viewpoint of contributing to the thinning of the entire polarizing plate and effectively suppressing the possible reverse curling, the thickness of the liquid crystal layer is preferably 5 μm or less. In addition, when the thickness of the liquid crystal layer is less than 0.3 μm, there is a tendency that the degree of reverse curling is slight, and thus there is little necessity to use the manufacturing method of the optical laminate and the manufacturing method of the optical laminate with an adhesive layer of the above-described embodiment.

[0228] (Liquid crystal layer with a substrate layer)

[0229] The first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer (hereinafter sometimes referred to as "liquid crystal layer with a substrate layer" collectively.) can be obtained by the following operation: on the substrate layer, a liquid crystal layer-forming composition containing a polymeric liquid crystal compound is coated and dried to form a liquid crystal layer as a cured layer formed by polymerizing the polymeric liquid crystal compound. When an alignment layer described later is formed on the substrate layer, the liquid crystal layer-forming composition may be coated on the alignment layer. In the case where the liquid crystal layer has a multi-layer structure of two or more layers, a multi-layer structure can be formed by sequentially coating liquid crystal layer-forming compositions having different compositions.

[0230] In addition to the polymeric liquid crystal compound, the liquid crystal layer-forming composition usually contains a solvent. The liquid crystal layer-forming composition may further contain a polymerization initiator, a reactive additive, a polymerization inhibitor, etc. For the solvent, polymerization initiator, reactive additive, polymerization inhibitor, etc., the substances exemplified in JP-A-2015-163937, JP-A-2016-42185, WO2016 / 158940, and JP-A-2016-224128 can be used.

[0231] Coating of the composition for forming a liquid crystal layer can be carried out by using known methods such as spin coating method, extrusion method, gravure coating method, die coating method, die slot coating method, bar coating method, coater method and other coating methods, flexography and other printing methods. After coating the composition for forming a liquid crystal layer, it is preferable to remove the solvent under the condition that the polymerizable liquid crystal compound contained in the coating layer does not polymerize. As the drying method, natural drying method, ventilation drying method, heat drying, reduced pressure drying method and the like can be mentioned.

[0232] Polymerization of the polymerizable liquid crystal compound carried out after drying of the coating layer can be carried out by using known methods for polymerizing a compound having a polymerizable functional group. As the polymerization method, for example, thermal polymerization, photopolymerization and the like can be mentioned, and photopolymerization is preferred from the viewpoint of ease of polymerization. In the case of polymerizing the polymerizable liquid crystal compound by photopolymerization, it is preferable to use a composition containing a photoinitiator as the composition for forming a liquid crystal layer, coat the composition for forming a liquid crystal layer and dry it, and perform liquid crystal alignment on the polymerizable liquid crystal compound contained in the dried film, and perform photopolymerization while maintaining the liquid crystal alignment state unchanged.

[0233] Photopolymerization can be carried out by irradiating the polymerizable liquid crystal compound having undergone liquid crystal alignment in the dried film with active energy rays. As the irradiated active energy rays, they can be appropriately selected according to the type and amount of the polymerizable group possessed by the polymerizable liquid crystal compound, the type of the photoinitiator, etc. For example, one or more active energy rays selected from visible light, ultraviolet rays, laser, X-rays, α-rays, β-rays and γ-rays can be mentioned. Among them, from the viewpoints of being easy to control the progress of the polymerization reaction and being able to use a device widely used in this field as a photopolymerization device, ultraviolet rays are preferred, and the types of the polymerizable liquid crystal compound and the photoinitiator are preferably selected in such a way that photopolymerization can be carried out by ultraviolet rays. During photopolymerization, the polymerization temperature can also be controlled by irradiating active energy rays while cooling the dried film by using an appropriate cooling mechanism.

[0234] (Substrate layer)

[0235] The first substrate layer and the second substrate layer (hereinafter sometimes referred to as "substrate layer" together.) have the function of a support layer for supporting the first alignment layer and the second alignment layer, and the first liquid crystal layer and the second liquid crystal layer formed thereon. The substrate layer is preferably a film formed of a resin material.

[0236] As the resin material, for example, a resin material with excellent transparency, mechanical strength, thermal stability, stretchability, etc. can be used. Specifically, polyolefin resins such as polyethylene and polypropylene can be cited; cyclic polyolefin resins such as norbornene-based polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth)acrylic resins such as (meth)acrylic acid and poly(methyl)methacrylate; cellulose ester resins such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; vinyl alcohol resins such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resins; polystyrene resins; polyarylate resins; polysulfone resins; polyethersulfone resins; polyamide resins; polyimide resins; polyether ketone resins; polyphenylene sulfide resins; polyphenylene ether resins; and their mixtures, copolymers, etc. Among these resins, any one of cyclic polyolefin resins, polyester resins, cellulose ester resins, and (meth)acrylic resins or their mixtures is preferably used.

[0237] The substrate layer can be a single layer of 1 kind of resin or a mixture of 2 or more resins, or can have a multilayer structure of 2 or more layers. In the case of having a multilayer structure, the resins for making each layer can be the same or different from each other, and can also be a coating / curing layer such as a hard coat.

[0238] In the resin material for making the film formed of the resin material, optional additives can be added. As the additives, for example, ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic interference agents, pigments, and coloring agents, etc. can be cited.

[0239] The thicknesses of the first substrate layer and the second substrate layer are not particularly limited. However, generally, from the aspects of operability such as strength and disposability, it is preferably 1 to 300 μm, more preferably 10 to 200 μm, and further preferably 30 to 120 μm.

[0240] In the case where the first liquid crystal layer with a substrate layer has the first alignment layer described later, or the second liquid crystal layer with a substrate layer has the second alignment layer described later, in order to improve the adhesion between the first substrate layer and the first alignment layer, and the adhesion between the second substrate layer and the second alignment layer, at least the surface of the first substrate layer on the side where the first alignment layer is formed, and at least the surface of the second substrate layer on the side where the second alignment layer is formed can be subjected to corona treatment, plasma treatment, flame treatment, etc., or a primer layer can also be formed.

[0241] The substrate layer can be peeled off relative to the liquid crystal layer or the subsequent alignment layer (the first alignment layer or the second alignment layer), and the magnitude of the peeling force between the substrate layer and the liquid crystal layer or the alignment layer needs to be determined in consideration of the order of peeling the substrate layer. The peeling force can be measured in the same manner as the method for measuring the peeling force between the peeling layer and the adhesive layer, except by using a test piece having a liquid crystal layer on the substrate layer or a test piece having an alignment layer and a liquid crystal layer on the substrate layer. The peeling force between the substrate layer and the liquid crystal layer or the alignment layer is preferably 0.01 to 0.50 N / 25 mm, more preferably 0.03 to 0.20 N / 25 mm, and still more preferably 0.05 to 0.18 N / 25 mm. If the peeling force is lower than the above lower limit value, warping may occur between the substrate layer and the liquid crystal layer or the alignment layer during transportation. In addition, if the peeling force is greater than the above upper limit value, due to excessive adhesion, it may be impossible to transfer the liquid crystal layer, or the liquid crystal layer and the alignment layer, to another liquid crystal layer, optical film, etc., and the peeling interface may change during transportation of each component in the process of manufacturing an optical laminate or an optical laminate with an adhesive layer.

[0242] The difference between the peeling force between the first substrate layer and the first liquid crystal layer or the subsequent first alignment layer (hereinafter sometimes referred to as "the first peeling force") and the peeling force between the second substrate layer and the second liquid crystal layer or the subsequent second alignment layer (hereinafter sometimes referred to as "the second peeling force") is preferably 0.01 N / 25 mm or more, more preferably 0.03 N / 25 mm or more. When peeling the first substrate layer first from the liquid crystal layer laminate with a substrate layer, it is preferable that the second peeling force is greater than the first peeling force. When peeling the second substrate layer first from the liquid crystal layer laminate with a substrate layer, it is preferable that the first peeling force is greater than the second peeling force. In addition, when peeling the first substrate layer first from the liquid crystal layer laminate with a substrate layer, from the viewpoint of long-size processing, it is preferable that the relationship of the peeling force between the second peeling layer and the second adhesive layer < the first peeling force < the second peeling force exists.

[0243] (Alignment layer)

[0244] The first liquid crystal layer with a substrate layer may include a first alignment layer between the first substrate layer and the first liquid crystal layer. In addition, the second liquid crystal layer with a substrate layer may include a second alignment layer between the second substrate layer and the second liquid crystal layer.

[0245] The first alignment layer and the second alignment layer have an alignment restricting force that causes the liquid crystal compounds contained in the first liquid crystal layer and the second liquid crystal layer formed on these alignment layers to be aligned in a desired direction. Examples of the first alignment layer and the second alignment layer include an alignment polymer layer formed of an alignment polymer, a photo-alignment polymer layer formed of a photo-alignment polymer, and a groove alignment layer having an uneven pattern or a plurality of grooves on the layer surface. The first alignment layer and the second alignment layer may be the same type of layer or different types of layers. The thickness of the first alignment layer and the second alignment layer is generally 10 to 4000 nm, preferably 50 to 3000 nm.

[0246] The alignment polymer layer can be formed as follows: dissolve the alignment polymer in a solvent, coat the resulting composition on a substrate layer (the first substrate layer or the second substrate layer), remove the solvent, and perform a rubbing treatment as needed. In this case, in the alignment polymer layer formed of the alignment polymer, the alignment restricting force can be arbitrarily adjusted by using the surface state of the alignment polymer and the rubbing conditions.

[0247] The photo-alignment polymer layer can be formed by coating a composition containing a polymer or monomer having a photoreactive group and a solvent on a substrate layer (the first substrate layer or the second substrate layer) and irradiating light such as ultraviolet light. Especially in the case of exhibiting an alignment restricting force in the horizontal direction, etc., it can be formed by irradiating polarized light. In this case, in the photo-alignment polymer layer, the alignment restricting force can be arbitrarily adjusted by using the polarized light irradiation conditions for the photo-alignment polymer, etc.

[0248] The groove alignment layer can be formed, for example, by a method of forming an uneven pattern by performing exposure, development, etc. on the surface of a photosensitive polyimide film with an exposure mask having a slit with a pattern shape; a method of forming an uncured layer of an active energy ray curable resin on a plate-shaped master having grooves on its surface, transferring this layer to a substrate layer (the first substrate layer or the second substrate layer) and curing it; a method of forming an uncured layer of an active energy ray curable resin on a substrate layer (the first substrate layer or the second substrate layer), and forming and curing unevenness by pressing a roller-shaped master having unevenness against this layer.

[0249] When the first liquid crystal layer with a substrate layer includes a first alignment layer, when the first substrate layer is peeled off, the first alignment layer can be peeled off together with the first substrate layer, or the first alignment layer can remain on the first liquid crystal layer. When the second liquid crystal layer with a substrate layer includes a second alignment layer, when the second substrate layer is peeled off, the second alignment layer can be peeled off together with the second substrate layer, or the second alignment layer can remain on the second liquid crystal layer. It should be noted that whether to peel off the first alignment layer together with the first substrate layer or leave it on the first liquid crystal layer can be set by adjusting the relationship of the adhesion force between the layers. For example, it can be adjusted by using the above-mentioned corona treatment, plasma treatment, flame treatment, primer layer and other surface treatments on the first substrate layer, or the components of the liquid crystal layer forming composition used to form the first liquid crystal layer. Similarly, by using the surface treatment on the second substrate layer, the second alignment layer can be peeled off together with the second substrate layer or left on the second liquid crystal layer.

[0250] When the first alignment layer remains on the first liquid crystal layer, the first adhesive cured layer can be provided on the first alignment layer. In addition, when the second alignment layer remains on the second liquid crystal layer, the adhesive layer can be provided on the second alignment layer.

[0251] (Circular polarizing plate)

[0252] The optical laminate of this embodiment can be used as a circular polarizing plate. When using Figure 4 the optical laminate 70 shown in (b) as a circular polarizing plate, the optical film 60 can be a polarizer, a polarizing plate, or a polarizing plate with a protective film, the first liquid crystal layer 12 can be a 1 / 2 wavelength retardation layer, and the second liquid crystal layer 22 can be a 1 / 4 wavelength retardation layer. Alternatively, on the basis of setting the optical film 60 as a polarizer, a polarizing plate, or a polarizing plate with a protective film as described above, the first liquid crystal layer 12 can be set as an inverse wavelength dispersion type 1 / 4 wavelength retardation layer, and the second liquid crystal layer 22 can be set as a positive C plate, whereby a circular polarizing plate can also be obtained.

[0253] [Examples]

[0254] Hereinafter, examples and comparative examples are given to further specifically illustrate the present invention, but the present invention is not limited by these examples. In the examples and comparative examples, "%" and "parts" are mass % and mass parts unless otherwise specified.

[0255] [Measurement of curling (1)]

[0256] From the optical laminates with an adhesive layer obtained in each example and each comparative example, a rhombus shape with a side length of 100 mm was cut out, and its diagonals were made parallel to the MD direction and the TD direction, respectively. After the obtained cut-out pieces were placed in an environment of 23°C and 55% relative humidity for 24 hours, the first spacer was peeled off to prepare test pieces. After sufficiently eliminating the static electricity of the test pieces, the test pieces were placed on a reference surface (a horizontal table) with the concave surface facing up, and the height of each of the four corners of the test pieces relative to the reference surface was measured. For the measured values, if the test piece was placed on the reference surface with the protective film side facing up, when the corner of the test piece was warped, this curl was defined as a positive curl, and the height of the corner relative to the reference surface was represented by a positive value. On the other hand, if the test piece was placed on the reference surface with the protective film side facing down, when the corner of the test piece was warped, this curl was defined as a reverse curl, and the height of the corner relative to the reference surface was represented by a negative value.

[0257] For the measured values obtained by measuring the test pieces from the optical laminates with an adhesive layer, the measured values of the heights of the two corners on the diagonal parallel to the MD direction relative to the reference surface were averaged, and the obtained value was calculated as the measured MD curl value. The measured values of the heights of the two corners on the diagonal parallel to the TD direction relative to the reference surface were averaged, and the obtained value was calculated as the measured TD curl value.

[0258] In addition, for the polarizing plates with a protective film used in each example and each comparative example, they were also cut out using the same steps as above. The height of each of the four corners of the obtained test pieces relative to the reference surface was measured, and the measured values were averaged using the same steps as above. The measured MD curl value and the measured TD curl value were calculated for the polarizing plates with a protective film.

[0259] From the measured MD curl value of the obtained polarizing plate with a protective film, the measured MD curl value of the optical laminate with an adhesive layer was subtracted, and the obtained value was used as the MD curl value of the optical laminate with an adhesive layer when there was a protective film. Similarly, from the measured TD curl value of the obtained polarizing plate with a protective film, the measured TD curl value of the optical laminate with an adhesive layer was subtracted, and the obtained value was used as the TD curl value of the optical laminate with an adhesive layer when there was a protective film.

[0260] 〔Measurement of curl (2)〕

[0261] Cut out pieces from the optical laminates with an adhesive layer obtained from each example and each comparative example. Use the material obtained by peeling off the protective film together with the first spacer from the cut-out pieces as test pieces. Otherwise, using the same procedure as in the above measurement of curl (1), calculate the measured MD curl value and the measured TD curl value of the optical laminate from which the protective film has been peeled off. Note that for the measured values, if the test piece is placed on the reference plane with the polarizing plate side facing up, in the case where the corner of the test piece is warped, this curl is defined as a positive curl, and the height of the corner relative to the reference plane is represented by a positive value. On the other hand, if the test piece is placed on the reference plane with the polarizing plate side facing down, in the case where the corner of the test piece is warped, this curl is defined as a reverse curl, and the height of the corner relative to the reference plane is represented by a negative value.

[0262] In addition, cut out pieces from the polarizing plates with a protective film used in each example and each comparative example. For the polarizing plates from which the protective film has been peeled off from the cut-out pieces, also measure the height of each of the four corners of the test pieces cut out using the same procedure as above relative to the reference plane, and average the measured values using the same procedure as above to calculate the measured MD curl value and the measured TD curl value of the polarizing plate from which the protective film has been peeled off.

[0263] Subtract the measured MD curl value of the optical laminate from which the protective film has been peeled off from the measured MD curl value of the polarizing plate from which the protective film has been peeled off, and use the resulting value as the MD curl value of the optical laminate with an adhesive layer without a protective film. Similarly, subtract the measured TD curl value of the optical laminate from which the protective film has been peeled off from the measured TD curl value of the polarizing plate from which the protective film has been peeled off, and use the resulting value as the TD curl value of the optical laminate with an adhesive layer without a protective film.

[0264] If the MD curl value and the TD curl value obtained in the above measurements of curl (1) and (2) are positive or 0, it indicates that reverse curl is suppressed. In addition, when the value is negative, the larger the absolute value, the more severe the reverse curl.

[0265] 〔Preparation of an Adhesive Layer with Spacers on Both Sides〕

[0266] An adhesive is manufactured using the following method. Into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen inlet tube, add 97.0 parts of n-butyl acrylate, 1.0 part of acrylic acid, 0.5 part of 2-hydroxyethyl acrylate, 200 parts of ethyl acetate, and 0.08 part of 2,2′-azobisisobutyronitrile. Replace the air inside the above reaction vessel with nitrogen. While stirring under a nitrogen atmosphere, heat the reaction solution to 60 °C, and after reacting for 6 hours, cool it to room temperature. Measure the weight-average molecular weight of a part of the resulting solution, and as a result, confirm that a (meth)acrylate polymer with a weight-average molecular weight of 1.8 million is obtained.

[0267] 100 parts (in terms of solid content; the same applies hereinafter) of the (meth)acrylate polymer obtained by the above operation, 0.30 part of trimethylolpropane-modified toluene diisocyanate (manufactured by Tosoh Corporation, trade name “CORONATE L”) as an isocyanate-based crosslinking agent, and 0.30 part of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KBM403”) as a silane coupling agent were mixed, stirred well, and diluted with ethyl acetate to obtain a coating solution of the adhesive composition.

[0268] The coating solution of the above adhesive composition was applied to the release-treated surface (release surface) of the first spacer (manufactured by LINTEC Corporation: SP-PLR382190) forming the release layer using a coater so that the dried thickness was 25 μm, and then dried at 100 °C for 1 minute to form an adhesive layer. On the side of the adhesive layer opposite to the surface that adheres to the spacer, another second spacer (manufactured by LINTEC Corporation: SP-PLR381031) was adhered to obtain an adhesive layer with spacers on both sides.

[0269] 〔Preparation of Adhesive Composition〕

[0270] The following cationic curable components a1 to a3 and a cationic polymerization initiator were mixed, and then the following cationic polymerization initiator and a sensitizer were further mixed, and then degassed to prepare a photocurable adhesive composition.

[0271] · Cationic curable component a1 (70 parts):

[0272] 3′,4′-Epoxycyclohexylmethyl 3′,4′-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation);

[0273] · Cationic curable component a2 (20 parts):

[0274] Neopentyl glycol diglycidyl ether (trade name: EX-211, manufactured by Nagase ChemteX Corporation);

[0275] · Cationic curable component a3 (10 parts):

[0276] 2-Ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation);

[0277] · Cationic polymerization initiator (2.25 parts (solid content amount)):

[0278] Product Name: 50% Propylene Carbonate Solution of CPI-100 (manufactured by San-Apro Ltd.);

[0279] · Sensitizer (2 parts):

[0280] 1,4-Diethoxynaphthalene.

[0281] [Preparation of Polarizing Plate with Protective Film]

[0282] A polyvinyl alcohol film with a thickness of 20 μm (average degree of polymerization of about 2400 and saponification degree of 99.9 mol% or more) is uniaxially stretched by dry stretching to about 5 times, then immersed in pure water at 60 °C for 1 minute while keeping the tension unchanged, and then immersed in an aqueous solution with a mass ratio of iodine / potassium iodide / water of 0.05 / 5 / 100 at 28 °C for 60 seconds. Thereafter, it is immersed in an aqueous solution with a mass ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 °C for 300 seconds. Next, it is washed with pure water at 26 °C for 20 seconds and then dried at 65 °C to obtain a polarizer with a thickness of 7 μm on which iodine is adsorbed and oriented on the polyvinyl alcohol film.

[0283] Then, an epoxy adhesive obtained as follows is coated on one side of the polarizer. That is, 3 parts of carboxyl-modified polyvinyl alcohol (trade name "KL-318" obtained from Kuraray Co., Ltd.) is dissolved in 100 parts of water, and 1.5 parts of a polyamide epoxy additive (trade name "Sumirez Resin 650(30)", an aqueous solution with a solid content concentration of 30%) as a water-soluble epoxy resin is added to this aqueous solution. As a protective layer, a transparent norbornene-based resin film with a thickness of 13 μm is laminated. By operating as described above, a polarizing plate with a protective layer laminated on one side of the polarizer is obtained. Then, a protective film with an acrylic adhesive layer of 15 μm formed on a polyethylene terephthalate (PET) film with a thickness of 38 μm is laminated on the surface of the norbornene-based resin film on the side opposite to the polarizer to obtain a polarizing plate with a protective film having a thickness of 73 μm. The measured MD curl value of this polarizing plate with a protective film is -20 mm, and the measured TD curl value is 1 mm. In addition, the measured MD curl value of the polarizing plate from which the protective film has been peeled off is 4 mm, and the measured TD curl value is -1 mm.

[0284] [Preparation of First Liquid Crystal Layer with Substrate Layer and Second Liquid Crystal Layer with Substrate Layer]

[0285] [Preparation of Photo-Orientation Layer Forming Composition (1)]

[0286] The following components are mixed, and the resulting mixture is stirred at a temperature of 80 °C for 1 hour to obtain the photo-orientation layer forming composition (1).

[0287] · Photo-alignment material (5 parts):

[0288] [Chemical formula 2]

[0289]

[0290] · Solvent (95 parts): Cyclopentanone.

[0291] (Preparation of the composition for forming an alignment layer (2))

[0292] 2-Butoxyethanol was added to commercially available SUNEVER SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is an alignment polymer, to obtain the composition for forming an alignment layer (2). The content ratio of the solid component of the obtained composition for forming an alignment layer (2) with respect to the total amount of the composition is 1%, and the content ratio of the solvent with respect to the total amount of the composition is 99%. The amount of the solid component of SUNEVER SE-610 was obtained by conversion based on the concentration described in the product specification sheet.

[0293] (Preparation of the composition for forming a liquid crystal layer (A-1))

[0294] The following components were mixed, and the resulting mixture was stirred at 80 °C for 1 hour to obtain the composition for forming a liquid crystal layer (A-1). The polymerizable liquid crystal compound A1 and the polymerizable liquid crystal compound A2 were synthesized by the method described in Japanese Patent Application Laid-Open No. 2010-31223.

[0295] · Polymerizable liquid crystal compound A1 (80 parts):

[0296] [Chemical formula 3]

[0297]

[0298] · Polymerizable liquid crystal compound A2 (20 parts):

[0299] [Chemical formula 4]

[0300]

[0301] · Polymerization initiator (6 parts):

[0302] 2-Dimethylamino-2-benzyl-1-(4-morpholinophenyl)-1-butanone (Irgacure 369; manufactured by Ciba Specialty Chemicals);

[0303] · Solvent (400 parts): Cyclopentanone.

[0304] (Preparation of the composition for forming a liquid crystal layer (B-1))

[0305] Mix the following components, and after stirring the resulting mixture at 80 °C for 1 hour, cool it to room temperature to obtain the liquid crystal layer-forming composition (B-1).

[0306] · Polymerizable liquid crystal compound LC242 (manufactured by BASF) (19.2%):

[0307] [Chemical formula 5]

[0308]

[0309] · Polymerization initiator (0.5%):

[0310] Irgacure (registered trademark) 907 (manufactured by BASF Japan);

[0311] · Reaction additive (1.1%):

[0312] Laromer (registered trademark) LR-9000 (manufactured by BASF Japan);

[0313] · Solvent (79.1%): Propylene glycol 1-monomethyl ether 2-acetate.

[0314] (Manufacture of the first liquid crystal layer with a substrate layer)

[0315] Use a corona treatment device (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) to treat a 100-μm-thick polyethylene terephthalate (PET) film once under the conditions of a power of 0.3 kW and a treatment speed of 3 m / min. Coat the photo-alignment layer-forming composition (1) on the surface where the corona treatment has been carried out with a bar coater, dry it at 80 °C for 1 minute, and use a polarized UV light irradiation device (SPOTCURE SP-7; manufactured by USHIO Inc.) to perform polarized UV exposure with a cumulative light amount of 100 mJ / cm 2 to obtain a photo-alignment layer. Measure the thickness of the obtained photo-alignment layer using a laser microscope (LEXT, manufactured by Olympus Corporation), and the result is 100 nm.

[0316] Next, coat the liquid crystal layer-forming composition (A-1) on the photo-alignment layer with a bar coater, dry it at 120 °C for 1 minute, and then use a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by USHIO Inc.) to irradiate ultraviolet rays (in a nitrogen atmosphere, wavelength: 365 nm, cumulative light amount at a wavelength of 365 nm: 1000 mJ / cm 2 ) to form the first liquid crystal layer as a retardation layer, and obtain the first liquid crystal layer with a substrate layer. The thickness of the first liquid crystal layer is 2 μm.

[0317] (Manufacture of the second liquid crystal layer with a substrate layer)

[0318] A corona treatment device (AGF - B10, manufactured by Kasuga Electric Co., Ltd.) was used to treat a polyethylene terephthalate (PET) film with a thickness of 38 μm once under the conditions of a power of 0.3 kW and a treatment speed of 3 m / min. The composition for forming an alignment layer (2) was bar-coated on the surface where the corona treatment was carried out and dried at 90°C for 1 minute to obtain an alignment layer. The thickness of the obtained alignment layer was measured using a laser microscope (LEXT, manufactured by Olympus Corporation), and the result was 34 nm.

[0319] Next, the composition for forming a liquid crystal layer (B - 1) was bar-coated on the alignment layer. After drying at 90°C for 1 minute, a high-pressure mercury lamp (Unicure VB - 15201BY - A, manufactured by USHIO Inc.) was used to irradiate ultraviolet light (in a nitrogen atmosphere, wavelength: 365 nm, cumulative light quantity at a wavelength of 365 nm: 1000 mJ / cm 2 ), thereby forming a second liquid crystal layer as a retardation layer to obtain a second liquid crystal layer with a substrate layer. The thickness of the second liquid crystal layer was 1 μm.

[0320] 〔Example 1〕

[0321] Using the first liquid crystal layer with a substrate layer, the second liquid crystal layer with a substrate layer, and the adhesive layer with spacers on both sides prepared in the above operations, an optical laminate with an adhesive layer was obtained through the process shown in Figures 1 to 6 . Specifically, it was carried out as follows.

[0322] The surface on the second liquid crystal layer side of the second liquid crystal layer with a substrate layer (length in the MD direction: 300 mm × length in the TD direction: 200 mm) prepared in the above operations was subjected to corona treatment (800 W, 10 m / min, bar electrode width: 700 mm, 1 Pass). The adhesive composition prepared in the above operations was bar-coated on this corona-treated surface using a coater (bar coater manufactured by Daiichi Rika Co., Ltd.) so that the thickness of the adhesive cured layer was 1 μm to form an adhesive composition layer (refer to Figure 1 (c)). Then, the surface on the first liquid crystal layer side of the first liquid crystal layer with a substrate layer (length in the MD direction: 300 mm × length in the TD direction: 200 mm) prepared in the above operations was subjected to corona treatment under the same conditions as above, and this corona-treated surface was bonded to the adhesive composition layer formed on the second liquid crystal layer with a substrate layer using a bonding device (“LPA3301” manufactured by FUJIPLA Co., Ltd.) (refer to Figure 1(d)), from the side of the second liquid crystal layer with the substrate layer, using an ultraviolet irradiation device with a conveyor belt (the lamp is the "H lamp tube" manufactured by Fusion UV Systems), irradiate with an irradiation intensity of 390 mW / cm in the UVA region 2 and a cumulative light quantity of 420 mJ / cm 2 , 400 mW / cm in the UVB region 2 and a cumulative light quantity of 400 mJ / cm 2 to cure the adhesive composition by irradiating ultraviolet rays, and obtain a liquid crystal layer laminate with a substrate layer (refer to Figure 2 (a)). It should be noted that if the storage modulus at room temperature of the adhesive cured layer obtained by curing the above adhesive composition layer is calculated by the above calculation method, it is about 3000 MPa.

[0323] Perform corona treatment (800 W, 10 m / min, bar electrode width 700 mm, 1 Pass) on the surface of the polarizing plate with a protective film prepared in the above operation (MD direction length 300 mm × TD direction length 200 mm) on the side opposite to the protective film side (polarizer side). Use a coater (a bar coater manufactured by Daiichi Rika Co., Ltd.) to coat the adhesive composition prepared in the above operation so that the thickness of the adhesive cured layer is 1 μm to form an adhesive composition layer, and obtain a polarizing plate with a composition layer (refer to Figure 3 (a)).

[0324] Bond the surface (the surface on the first liquid crystal layer side) exposed by peeling off the PET film (thickness 100 μm) of the first liquid crystal layer with the substrate layer of the liquid crystal layer laminate with the substrate layer to the adhesive composition layer of the polarizing plate with the composition layer using a bonding device ("LPA3301" manufactured by FUJIPLA Co., Ltd.) (refer to Figure 3 (b)), from the protective film side of the polarizing plate with the composition layer, using an ultraviolet irradiation device with a conveyor belt (the lamp is the "H lamp tube" manufactured by Fusion UV Systems), irradiate with an irradiation intensity of 390 mW / cm in the UVA region 2 and a cumulative light quantity of 420 mJ / cm 2 , 400 mW / cm in the UVB region 2 and a cumulative light quantity of 400 mJ / cm 2 to cure the adhesive composition by irradiating ultraviolet rays, and obtain an optical laminate with a substrate layer (refer to Figure 4(a)). The surface (the surface on the side of the second liquid crystal layer) of the PET film (thickness: 38 μm) of the second liquid crystal layer with the substrate layer of the optically laminated body with the substrate layer obtained by peeling is single-sheet bonded to the adhesive layer (300 mm × 200 mm) with spacers on both sides prepared in the above operation after peeling the second spacer, to obtain an optically laminated body with an adhesive layer (1) (refer to Figure 5 (b)). The obtained optically laminated body with an adhesive layer (1) is subjected to curl measurement (1) and (2), and the MD curl value and TD curl value of the optically laminated body with an adhesive layer (1) are calculated.

[0325] The results are shown in Table 1.

[0326] 〔Comparative Example 1〕

[0327] Using the first liquid crystal layer with the substrate layer, the second liquid crystal layer with the substrate layer, and the adhesive layer with spacers on both sides prepared in the above operation, an optically laminated body with an adhesive layer is obtained by the process shown in Figures 7 to 9 . Specifically, it is carried out as follows.

[0328] The surface on the side opposite to the protective film side (polarizer side) of the polarizing plate with a protective film (MD direction length: 300 mm × TD direction length: 200 mm) prepared in the above operation is subjected to corona treatment (800 W, 10 m / min, bar electrode width: 700 mm, 1 Pass). In addition, the second spacer is peeled from the adhesive layer with spacers on both sides (300 mm × 200 mm) prepared in the above operation. Using an automatic laminator HALTEC, the corona-treated surface of the polarizing plate with a protective film is single-sheet bonded to the adhesive layer exposed by peeling the second spacer from the adhesive layer with spacers on both sides to obtain a polarizing plate with an adhesive layer (refer to Figure 7 (a)).

[0329] The adhesive layer exposed by peeling the first spacer from the above polarizing plate with an adhesive layer is single-sheet bonded to the first liquid crystal layer of the first liquid crystal layer with the substrate layer (MD direction length: 300 mm × TD direction length: 200 mm) prepared in the above operation using an automatic laminator HALTEC (refer to Figure 7 (c)).

[0330] Next, the surface (the surface on the side of the first liquid crystal layer) of the first liquid crystal layer with the substrate layer bonded to the polarizing plate with a protective film, which is exposed by peeling the PET film (thickness: 100 μm), and the adhesive layer exposed by peeling the second spacer from the adhesive layer with spacers on both sides (300 mm × 200 mm) prepared in the above operation are single-sheet bonded using an automatic laminator HALTEC, and then the first spacer is peeled off (refer to Figure 8(a)). The adhesive layer exposed by peeling off the first spacer and the second liquid crystal layer with a substrate layer (length in the MD direction: 300 mm × length in the TD direction: 200 mm) prepared in the above operation are single-sheet laminated using an automatic laminator HALTEC to obtain an optical laminate with a substrate layer ( Figure 8 (c)).

[0331] The surface (the surface on the second liquid crystal layer side) exposed by peeling off the PET film (thickness: 38 μm) of the second liquid crystal layer with a substrate layer from the obtained optical laminate with a substrate layer and the adhesive layer exposed by peeling off the second spacer from the adhesive layer with spacers on both sides (300 mm × 200 mm) prepared in the above operation are single-sheet laminated using an automatic laminator HALTEC to obtain an optical laminate (2) with an adhesive layer. The curl measurements (1) and (2) are performed on the obtained optical laminate (2) with an adhesive layer, and the MD curl value and TD curl value of the optical laminate (2) with an adhesive layer are calculated. The results are shown in Table 1.

[0332] [Table 1]

[0333]

[0334] As shown in Table 1, compared with the optical laminate with an adhesive layer obtained in Comparative Example 1, the reverse curl of the optical laminate with an adhesive layer obtained in Example 1 is suppressed, and it can be seen that the manufacturing method of the optical laminate with an adhesive layer described in the above embodiment can suppress the reverse curl.

Claims

1. A method for manufacturing an optical laminate with an adhesive layer, which is a method for manufacturing an optical laminate with an adhesive layer obtained by laminating an optical film, a first adhesive cured layer, a first liquid crystal layer, a second adhesive cured layer, a second liquid crystal layer, and an adhesive layer. The optical film includes a polarizing plate with a protective film laminated on at least one side of the polarizing plate, and the polarizing plate is a polarizing plate with a protective layer formed on at least one side of the polarizing film. The protective film includes a resin film for the protective film and a bonding layer for the protective film laminated thereon, and the resin constituting the resin film for the protective film is selected from polyolefin resins, cyclic olefin resins, polyester resins, and polycarbonate resins. This manufacturing method includes: a step of preparing a first liquid crystal layer with a substrate layer, the first liquid crystal layer with a substrate layer having a first substrate layer and the first liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the first substrate layer, and the thickness of the first substrate layer is 100 μm or more and 300 μm or less; a step of preparing a second liquid crystal layer with a substrate layer, the second liquid crystal layer with a substrate layer having a second substrate layer and the second liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the second substrate layer; a step of obtaining a liquid crystal layer laminate with a substrate layer, laminating the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer so that the first liquid crystal layer and the second liquid crystal layer face each other with the second adhesive cured layer interposed therebetween to obtain a liquid crystal layer laminate with a substrate layer; a step of obtaining a liquid crystal layer laminate, peeling at least the first substrate layer from the liquid crystal layer laminate with a substrate layer to obtain a liquid crystal layer laminate; a step of obtaining an optical laminate, laminating the optical film with the first adhesive cured layer interposed therebetween on the first exposed surface side of the liquid crystal layer laminate exposed by peeling the first substrate layer to obtain an optical laminate; a step of peeling the second substrate layer from the liquid crystal layer laminate with a substrate layer or the optical laminate; and a step of laminating the adhesive layer on the second exposed surface side of the optical laminate exposed by peeling the second substrate layer.

2. The method for manufacturing an optical laminate with an adhesive layer according to claim 1, wherein, the step of obtaining the optical laminate includes: a step of forming a first adhesive composition layer, forming a first adhesive composition layer containing a first adhesive composition for forming the first adhesive cured layer on at least one of the optical film and the first exposed surface of the liquid crystal layer laminate; and a step of forming the first adhesive cured layer, after laminating the optical film on the first exposed surface side with the first adhesive composition layer interposed therebetween, curing the first adhesive composition layer to form the first adhesive cured layer.

3. The method for manufacturing an optical laminate with an adhesive layer according to claim 1 or 2, wherein, the step of obtaining the liquid crystal layer laminate with a substrate layer includes: A step of forming a second adhesive composition layer, forming a second adhesive composition layer containing an adhesive composition for forming the second adhesive cured layer on at least one of the first liquid crystal layer of the first liquid crystal layer with a substrate layer and the second liquid crystal layer of the second liquid crystal layer with a substrate layer; and A step of forming the second adhesive cured layer, after laminating the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer in such a manner that the first liquid crystal layer and the second liquid crystal layer face each other with the second adhesive composition layer interposed therebetween, curing the second adhesive composition layer to form the second adhesive cured layer.

4. The method for manufacturing an optical laminate with an adhesive layer according to claim 1 or 2, wherein, The step of obtaining the liquid crystal layer laminate is a step of peeling the first substrate layer from the liquid crystal layer laminate with a substrate layer and not peeling the second substrate layer, The manufacturing method includes a step of peeling the second substrate layer from the optical laminate.

5. The method for manufacturing an optical laminate with an adhesive layer according to claim 1 or 2, wherein, The step of obtaining the liquid crystal layer laminate is a step of peeling the first substrate layer and the second substrate layer from the liquid crystal layer laminate with a substrate layer to obtain a liquid crystal layer laminate.

6. The method for manufacturing an optical laminate with an adhesive layer according to claim 1 or 2, wherein, The step of laminating the adhesive layer includes: A step of preparing an adhesive layer with a release layer in which the adhesive layer and the release layer are laminated, and a step of laminating the adhesive layer of the adhesive layer with a release layer to the second exposed surface of the optical laminate and then peeling the release layer.

7. A method for manufacturing an optical laminate with an adhesive layer, which is a method for manufacturing an optical laminate with an adhesive layer in which an optical film, a first adhesive cured layer, a first liquid crystal layer, a second adhesive cured layer, a second liquid crystal layer, and an adhesive layer are laminated in sequence, The optical film includes a polarizing plate with a protective film laminated on at least one surface of the polarizing plate, and the polarizing plate is a polarizing plate having a protective layer formed on at least one surface of the polarizing film, The protective film includes a protective film resin film and a protective film adhesive layer laminated thereon, and the resin constituting the protective film resin film is selected from polyolefin resins, cyclic olefin resins, polyester resins, and polycarbonate resins, This manufacturing method includes: A step of preparing a first liquid crystal layer with a substrate layer, the first liquid crystal layer with a substrate layer having a first substrate layer and the first liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the first substrate layer, and the thickness of the first substrate layer is 100 μm or more and 300 μm or less; A step of preparing a second liquid crystal layer with a substrate layer, the second liquid crystal layer with a substrate layer having a second substrate layer and the second liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the second substrate layer; A process for obtaining a liquid crystal layer laminate with a substrate layer, in which the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer are laminated in such a manner that the first liquid crystal layer and the second liquid crystal layer face each other with the second adhesive cured layer interposed therebetween, thereby obtaining a liquid crystal layer laminate with a substrate layer; A process for obtaining a liquid crystal layer laminate, in which the second substrate layer is at least peeled off from the liquid crystal layer laminate with a substrate layer, thereby obtaining a liquid crystal layer laminate; A process for obtaining a liquid crystal layer laminate with an adhesive layer, in which the adhesive layer is laminated on the second exposed surface side of the liquid crystal layer laminate exposed due to the peeling of the second substrate layer, thereby obtaining a liquid crystal layer laminate with an adhesive layer; A process for peeling off the first substrate layer from the liquid crystal layer laminate with a substrate layer or the liquid crystal layer laminate with an adhesive layer; and A process for laminating the optical film with the first adhesive cured layer interposed therebetween on the first exposed surface side of the liquid crystal layer laminate with an adhesive layer exposed due to the peeling of the first substrate layer.

8. The method for manufacturing an optical laminate with an adhesive layer according to claim 7, wherein, the process for obtaining a liquid crystal layer laminate with an adhesive layer includes: a process for preparing an adhesive layer with a release layer in which the adhesive layer and the release layer are laminated, and a process for laminating the adhesive layer of the adhesive layer with a release layer on the second exposed surface of the liquid crystal layer laminate and then peeling off the release layer.

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