Optical laminate, method for manufacturing a substrate laminate, and method for manufacturing a polarizing plate

Abstract

To provide a base material laminate body in which an end piece of an optical laminate body manufactured in the step of manufacturing a polarizer can be easily removed.SOLUTION: A base material laminate body A includes a base material layer 2 and a surface processing layer 3 directly laminated on the surface of the base material layer 2. The base material laminate body A includes a pair of end parts AE facing each other in a direction substantially parallel to the surface of the base material layer 2 and a center part AC between the pair of end parts AE. The strength of separation of the base material layer 2 from the surface processing layer 3 in at least one of the end parts AE of the base material laminate body A is denoted by Ie. The strength of separation of the base material layer 2 from the surface processing layer 3 in the center part AC of the base material laminate body A is denoted by Ic. Ie is larger than Ic.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a base material laminate, an optical laminate, a method for manufacturing a base material laminate, and a method for manufacturing a polarizing plate.

Background Art

[0002] A polarizing plate is used in an image display device (such as a liquid crystal display or an organic EL display) such as a television, a computer, a smartphone, a smartwatch, a portable game machine, or an instrument panel of a vehicle. The polarizing plate is manufactured by laminating a plurality of layers such as a protective layer (protective film), a polarizer layer, an adhesive layer, and a retardation layer. (See Patent Documents 1 to 4 below.)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] The method for manufacturing a polarizing plate includes, for example, a step of directly laminating a surface treatment layer (such as a hard coat layer) on a base material layer (such as a PET film) to obtain a base material laminate, a step of laminating a polarizer layer directly or indirectly on the surface treatment layer included in the base material laminate, and a step of laminating another resin layer (such as a retardation layer) directly or indirectly on the polarizer layer via an adhesive layer. An optical laminate is produced by at least these steps. Then, the polarizing plate is obtained by peeling the base material layer from the optical laminate.

[0005] It is desirable that the adhesive layer covers the entire surface of the adherend layer (e.g., a polarizer layer, an overcoat layer covering the polarizer layer, or a retardation layer) to which the adhesive layer is directly laminated. However, the ends of the surface of the adherend layer tend to be difficult to be covered by the adhesive layer. The portion not covered by the adhesive layer at the ends of the surface of the adherend layer is referred to as an "uncovered portion". The portion that indirectly overlaps with the uncovered portion at the ends of each of the plurality of layers (e.g., a surface treatment layer and a polarizer layer) laminated between the adhesive layer and the base material layer constitutes an "end piece" together with the uncovered portion. In other words, the end piece is a portion that is not directly or indirectly fixed by the adhesive layer at the ends of the above optical laminate produced in the manufacturing process of the polarizing plate. Since the end piece is not fixed by the adhesive layer, it is likely to fall off from the above optical laminate in the manufacturing process of the polarizing plate. The polarizer layer containing a polymer of a polymerizable liquid crystal compound and a dichroic dye is thinner and more easily damaged than a conventional polarizer layer (stretched film) containing polyvinyl alcohol. Therefore, when the polarizer layer contained in the optical laminate contains a polymer of a polymerizable liquid crystal compound and a dichroic dye, the end piece is likely to fall off from the optical laminate. The end piece that has fallen off from the optical laminate contaminates the manufacturing line of the polarizing plate. As a result, the end piece is likely to be mixed into the polarizing plate as a foreign matter, and the quality of the polarizing plate deteriorates. By cutting off the ends of the optical laminate before peeling the base material layer from the optical laminate, the end piece can be removed from the optical laminate. However, when the ends of the optical laminate are cut off, the man-hours required for manufacturing the polarizing plate increase, and the productivity of the polarizing plate decreases. Further, when the ends of the optical laminate are cut off, the normal ends that do not need to be cut are likely to be cut off together with the end piece, and the raw materials constituting the ends of the optical laminate are wasted. As a result, the productivity of the polarizing plate decreases.

[0006] An object of one aspect of the present invention is to provide a base material laminate, an optical laminate, a method for manufacturing the base material laminate, and a method for manufacturing a polarizing plate capable of easily removing an end piece of an optical laminate produced in the manufacturing process of the polarizing plate.

Means for Solving the Problems

[0007] The base material laminate according to one aspect of the present invention includes a base material layer and a surface treatment layer directly laminated on the surface of the base material layer. The base material laminate includes a pair of end portions facing each other in a direction substantially parallel to the surface of the base material layer, and a central portion located between the pair of end portions. The peel strength of the base material layer with respect to the surface treatment layer at at least one end portion of the base material laminate is represented as Ie. The peel strength of the base material layer with respect to the surface treatment layer at the central portion of the base material laminate is represented as Ic. Ie is higher than Ic.

[0008] Ie may be higher than Ic and 0.40 N / 25 mm or more. Ic may be lower than Ie and 0.55 N / 25 mm or less.

[0009] The optical laminate according to one aspect of the present invention includes the above-described base material laminate and a polarizer layer. The polarizer layer is directly or indirectly laminated on the surface of the surface treatment layer included in the base material laminate. The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye.

[0010] In a direction substantially parallel to the surface of the surface treatment layer, at least one end portion of the base material laminate may be located outside the region surrounded by the outer periphery of the polarizer layer.

[0011] The optical laminate according to one aspect of the present invention may include an adhesive layer and another resin layer. The adhesive layer may be directly or indirectly laminated on the surface of the polarizer layer. The other resin layer may be directly laminated on the surface of the adhesive layer.

[0012] In the optical laminate according to one aspect of the present invention, the other resin layer may be a retardation layer.

[0013] In a direction parallel to the surface of the surface treatment layer, at least one end portion of the base material laminate may be located outside the region surrounded by the outer periphery of the adhesive layer.

[0014] In a direction substantially parallel to the surface of the surface treatment layer and substantially perpendicular to the outer periphery of the adhesive layer, the width of at least one end portion of the base material laminate may be 0.1 mm or more and less than 55 mm.

[0015] In a direction parallel to the surface of the surface treatment layer, at least one end of the polarizer layer may be located outside the region surrounded by the outer periphery of the adhesive layer.

[0016] The method for manufacturing a base material laminate according to one aspect of the present invention is a method for manufacturing the above-described base material laminate, and includes a step of directly laminating a surface treatment layer on the surface of a base material layer to obtain a laminate, a step of winding the laminate to obtain a roll, and a step of heating at least one of a pair of opposite end faces of the roll.

[0017] The method for manufacturing a base material laminate according to another aspect of the present invention is a method for manufacturing the above-described base material laminate, and includes a step of performing corona treatment on at least one of a pair of opposite end portions of the base material layer, and a step of directly laminating a surface treatment layer on the surface of the base material layer after the corona treatment.

[0018] The method for manufacturing a polarizing plate according to one aspect of the present invention includes a step of peeling a base material layer from the above-described optical laminate.

[0019] The method for manufacturing a polarizing plate according to another aspect of the present invention includes a step of directly laminating a surface treatment layer on the surface of a base material layer, a step of laminating a polarizer layer directly or indirectly on the surface of the surface treatment layer, a step of laminating another resin layer directly or indirectly on the surface of the polarizer layer via an adhesive layer, a step of simultaneously heating the end portions of the base material layer and the surface treatment layer after the step of laminating another resin layer directly or indirectly on the surface of the polarizer layer via an adhesive layer, and a step of peeling the base material layer after the step of simultaneously heating the end portions of the base material layer and the surface treatment layer. By the step of simultaneously heating the end portions of the base material layer and the surface treatment layer, the peeling strength of the end portion of the base material layer with respect to the end portion of the surface treatment layer is increased. The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye.

[0020] In the method for manufacturing a polarizing plate according to another aspect of the present invention, the other resin layer may be a retardation layer.

Effects of the Invention

[0021] According to one aspect of the present invention, there are provided a base material laminate, an optical laminate, a method for manufacturing the base material laminate, and a method for manufacturing a polarizing plate, which can easily remove an end piece of the optical laminate produced during the manufacturing process of the polarizing plate.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0023] Hereinafter, a preferred embodiment (First Embodiment) of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals are assigned to the same components. The present invention is not limited to the following embodiments. X, Y, and Z shown in each figure represent three mutually orthogonal coordinate axes. The directions indicated by the XYZ coordinate axes in each figure are common to each figure. The X-axis direction may be rephrased as the width direction of each layer included in the base material laminate, the optical laminate, and the polarizing plate respectively. The Y-axis direction may be rephrased as the longitudinal direction or the conveyance direction of each layer included in the base material laminate, the optical laminate, and the polarizing plate respectively. The Z-axis direction may be rephrased as the lamination direction of the base material laminate, the optical laminate, and the polarizing plate respectively.

[0024] (Base material laminate, optical laminate, polarizing plate, and method for manufacturing polarizing plate) As shown in FIG. 1, the base material laminate A according to the first embodiment includes at least a base material layer 2 and a surface treatment layer 3 directly laminated on the surface of the base material layer 2. Each of the base material layer 2 and the surface treatment layer 3 may be a layer containing a resin (polymer compound) described later. The surface treatment layer 3 may be referred to as a first protective layer or a hard coat layer. The surface treatment layer 3 may cover the entire surface of the base material layer 2. A base material protective layer 1 (base material protective film) may be directly laminated on the surface of the base material layer 2 located on the back of the surface on which the surface treatment layer 3 is laminated. The base material laminate A includes a pair of end portions AE facing each other in a direction (X-axis direction) substantially parallel to the surface of the base material layer 2, and a central portion AC located between the pair of end portions AE. The central portion AC may be alternatively described as a portion located between the pair of end portions AE of the base material laminate A in a cross-section of the base material laminate A substantially perpendicular to the surface of the base material layer 2. The peel strength of the base material layer 2 with respect to the surface treatment layer 3 at at least one end portion AE of the base material laminate A is represented as Ie. The peel strength of the base material layer 2 with respect to the surface treatment layer 3 at each of both end portions AE of the base material laminate A may be represented as Ie. The peel strength of the base material layer 2 with respect to the surface treatment layer 3 at the central portion AC of the base material laminate A is represented as Ic. Ie is higher than Ic. The peel strength of the base material layer 2 with respect to the surface treatment layer 3 at one end portion AE of the base material laminate A may be equal to the peel strength of the base material layer 2 with respect to the surface treatment layer 3 at the other end portion AE of the base material laminate A. The peel strength of the base material layer 2 with respect to the surface treatment layer 3 at one end portion AE of the base material laminate A may be different from the peel strength of the base material layer 2 with respect to the surface treatment layer 3 at the other end portion AE of the base material laminate A. The unit of the peel strength is N / 25 mm. For example, the peel strength is measured by a 180-degree peel test in accordance with Japanese Industrial Standard (JIS Z 0237). The base material layer 2 can be easily peeled from the surface treatment layer 3 located at the central portion AC of the base material laminate A. The surface treatment layer 3 located at the central portion AC of the base material laminate A is difficult to be damaged along with the peeling of the base material layer 2.

[0025] The optical laminate according to the first embodiment includes at least a base laminate A and a polarizer layer. The polarizer layer is laminated directly or indirectly on the surface of the surface treatment layer included in the base laminate. The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye.

[0026] In addition to the base laminate A and the polarizer layer, the optical laminate may further include an adhesive layer and another resin layer. The adhesive layer (the first adhesive layer described later) is laminated directly or indirectly on the surface of the polarizer layer. The other resin layer is laminated directly on the surface of the adhesive layer. In other words, the other resin layer is laminated directly or indirectly on the surface of the polarizer layer via the adhesive layer. For example, the other resin layer may be a retardation layer, an optical compensation layer, or a protective layer (the third protective layer described later). When any two layers constituting the optical laminate are denoted as layer A and layer B, the layer B laminated directly on layer A means the layer B laminated on layer A without passing through other layers. The layer B laminated indirectly on layer A means the layer B laminated on layer A via other layers.

[0027] FIG. 2 shows an example of the laminated structure of the optical laminate. However, the laminated structure of the optical laminate according to the first embodiment is not limited to the structure shown in FIG. 2. The optical laminate B shown in FIG. 2 includes a base laminate A, an alignment layer 4 directly laminated on the surface of the surface treatment layer 3 (first protective layer) included in the base laminate A, a polarizer layer 5 directly laminated on the surface of the alignment layer 4, a second protective layer 6 (overcoat layer) directly laminated on the surface of the polarizer layer 5, a first adhesive layer 7 directly laminated on the surface of the second protective layer 6, a retardation layer 8 (other resin layer) directly laminated on the surface of the first adhesive layer 7, a second adhesive layer 9 directly laminated on the surface of the retardation layer 8, an optical compensation layer 10 directly laminated on the surface of the second adhesive layer 9, and a third protective layer 11 laminated on the surface of the optical compensation layer 10. The thickness of each layer included in the optical laminate may be substantially uniform. The shape of the optical laminate B and each layer in a direction substantially perpendicular to the lamination direction (thickness direction of the polarizer layer 5) of the optical laminate may be substantially the same as the shape of the screen of the image display device. For example, the shape of the optical laminate B and each layer in a direction substantially perpendicular to the lamination direction (thickness direction of the polarizer layer 5) of the optical laminate B may be rectangular (rectangle or square). However, the shape of the optical laminate B and each layer in a direction substantially perpendicular to the lamination direction (thickness direction of the polarizer layer 5) of the optical laminate B is not limited. One or more notch portions (notches) may be formed at the end of the optical laminate B. One or more through holes may be formed in the optical laminate B.

[0028] As shown in FIGS. 2 and 3, in a direction (X-axis direction) substantially parallel to the surface of the surface treatment layer 3, a part or all of one end AE of the base laminate A may be located outside the region surrounded by the outer periphery 7c of the first adhesive layer 7. That is, in a direction substantially parallel to the surface of the surface treatment layer 3, at least one end AE of the base laminate A may protrude beyond the end of the first adhesive layer 7. In a direction substantially parallel to the surface of the surface treatment layer 3, a part or all of each of both ends AE of the base laminate A may be located outside the region surrounded by the outer periphery 7c of the first adhesive layer 7.

[0029] As shown in FIGS. 2 and 3, at least one end portion AE of the base material laminate A may be located outside the region surrounded by the outer periphery 5c of the polarizer layer 5 in a direction substantially parallel to the surface of the surface treatment layer 3. That is, in a direction substantially parallel to the surface of the surface treatment layer 3, at least one end portion AE of the base material laminate A may protrude beyond the end portion of the polarizer layer 5. In a direction substantially parallel to the surface of the surface treatment layer 3, a part or all of both end portions AE of the base material laminate A may be located outside the region surrounded by the outer periphery 5c of the polarizer layer 5.

[0030] As shown in FIGS. 2 and 3, in a direction substantially parallel to the surface of the surface treatment layer 3, a part or all of at least one end portion of the polarizer layer 5 may be located outside the region surrounded by the outer periphery 7c of the first adhesive layer 7. That is, in a direction substantially parallel to the surface of the surface treatment layer 3, at least one end portion of the polarizer layer 5 may protrude beyond the end portion of the first adhesive layer 7. In a direction substantially parallel to the surface of the surface treatment layer 3, a part or all of both end portions of the polarizer layer 5 may be located outside the region surrounded by the outer periphery 7c of the first adhesive layer 7.

[0031] As shown in FIG. 2, in a direction substantially parallel to the surface of the surface treatment layer 3, at least one end portion of the alignment layer 4 may protrude beyond the end portion of the first adhesive layer 7. In a direction substantially parallel to the surface of the surface treatment layer 3, both end portions of the alignment layer 4 may protrude beyond the end portion of the first adhesive layer 7.

[0032] As shown in FIG. 2, in a direction substantially parallel to the surface of the surface treatment layer 3, at least one end portion of the second protective layer 6 may protrude beyond the end portion of the first adhesive layer 7. In a direction substantially parallel to the surface of the surface treatment layer 3, both end portions of the second protective layer 6 may protrude beyond the end portion of the first adhesive layer 7.

[0033] At both ends of the second protective layer 6 protruding beyond the ends of the first adhesive layer 7 in a direction parallel to the surface of the surface treatment layer 3, there are a pair of uncovered portions not covered by the first adhesive layer 7. Both ends of each of the surface treatment layer 3 (first protective layer), the alignment layer 4, and the polarizer layer 5 laminated between the first adhesive layer 7 and the base material layer 2 indirectly overlap with the pair of uncovered portions (both ends of the second protective layer 6). In other words, both ends of each of the surface treatment layer 3, the alignment layer 4, the polarizer layer 5, and the second protective layer 6 protrude beyond the ends of the first adhesive layer 7 in a direction parallel to the surface of the surface treatment layer 3. Therefore, both ends of each of the surface treatment layer 3, the alignment layer 4, and the polarizer layer 5, together with the pair of uncovered portions, constitute a pair of end pieces E. Since the pair of end pieces E are not fixed by the first adhesive layer 7, they are likely to fall off from the optical laminate B during the manufacturing process of the polarizing plate.

[0034] As shown in FIG. 4, the method for manufacturing the polarizing plate C includes a step of peeling the base material layer 2 (and the protective layer 1 for the base material) from the above-mentioned optical laminate B.

[0035] A pair of layers in contact with each other between the first adhesive layer 7 and the base material layer 2 (that is, the surface treatment layer 3 and the alignment layer 4, the alignment layer 4 and the polarizer layer 5, and the polarizer layer 5 and the second protective layer 6) are firmly adhered to each other during these lamination processes. That is, a pair of layers in contact with each other between the first adhesive layer 7 and the base material layer 2 are difficult to peel from each other. In contrast, the peel strength Ic of the base material layer 2 with respect to the surface treatment layer 3 at the central portion AC of the base material laminate A is sufficiently low. That is, the central portion of the base material layer 2 is easily peeled from the surface treatment layer 3. On the other hand, the peel strength Ie of the base material layer 2 with respect to the surface treatment layer 3 at both ends AE of the base material laminate A is higher than Ic. That is, both ends of the base material layer 2 are more firmly adhered to the surface treatment layer 3 than the central portion of the base material layer 2. That is, both ends of the base material layer 2 are difficult to peel from the surface treatment layer 3. Therefore, as the central portion of the base material layer 2 is peeled from the surface treatment layer 3, a pair of end pieces E adhered to both ends of the base material layer 2 can be easily separated from the ends of the optical laminate B together with the base material layer 2. The laminated structure of the polarizing plate C obtained by peeling the base material layer 2 (and the protective layer 1 for the base material) from the optical laminate B may be the same as the laminated structure of the optical laminate B, excluding the base material layer 2, the protective layer 1 for the base material, and the end piece E.

[0036] According to the first embodiment, by peeling the base material layer 2 from the optical laminate B, a pair of end pieces E adhered to both ends of the base material layer 2 can be easily removed from the ends of the optical laminate B. As a result, the dropping of the end piece E from the optical laminate B in the manufacturing process of the polarizing plate can be suppressed. By suppressing the dropping of the end piece E from the optical laminate B, the contamination of the manufacturing line of the polarizing plate C by the end piece E is suppressed, and the mixing of the end piece E into the polarizing plate C is suppressed. As a result, the quality of the polarizing plate C is improved.

[0037] According to the first embodiment, in order to remove the end piece E from the optical laminate B, the conventional process of cutting off the end of the optical laminate B before the base material layer 2 is isolated is unnecessary. As a result, the man-hours required for manufacturing the polarizing plate C are reduced, and the productivity of the polarizing plate C is improved. According to the first embodiment, since it is not necessary to cut off the normal end that does not need to be cut together with the end piece from the optical laminate B, the portion that can be used as the polarizing plate C after removing the end piece is likely to remain in the optical laminate B, and the waste of the raw material for the polarizing plate is suppressed. As a result, the productivity of the polarizing plate C is improved.

[0038] Ie may be higher than Ic and may be 0.40 N / 25 mm or more and 1.80 N / 25 mm or less. Ic may be lower than Ie and may be 0.05 N / 25 mm or more and 0.55 N / 25 mm or less. The higher Ie is, the easier the end piece E adheres to the end of the base material layer 2, and the easier the end piece E is removed from the optical laminate B by peeling the base material layer 2. The lower Ic is, the easier it is to peel the base material layer 2 from the surface treatment layer 3 at the central portion of the base material laminate A, and the breakage of the surface treatment layer 3 accompanying the peeling of the base material layer 2 is suppressed.

[0039] As shown in FIG. 3, in the direction (X-axis direction) substantially parallel to the surface of the surface treatment layer 3 and substantially perpendicular to the outer periphery 7c of the first adhesive layer 7, the width W of at least one end AE of the base material laminate A AEmay be 0.1 mm or more and less than 55 mm. The width W of each of at least both ends AE of the base material laminate A AE may be 0.1 mm or more and less than 55 mm. The width W of the end AE AE When it is 0.1 mm or more, the whole of the end piece E easily adheres to the end of the base material layer 2, and the whole of the end piece E can be reliably removed from the optical laminate B. The width W of the end AE AE When it is less than 55 mm, the normal ends removed from the optical laminate B together with the end piece E are sufficiently few, and a portion that can be used as the polarizing plate C easily remains after the removal of the end piece E.

[0040] For example, the thickness of the protective layer 1 for the base material may be 5 μm or more and 100 μm or less. For example, the thickness of the base material layer 2 may be 5 μm or more and 100 μm or less. For example, the thickness of the surface treatment layer 3 (first protective layer) may be 0.1 μm or more and 13 μm or less, 0.3 μm or more and 8 μm or less, or 0.5 μm or more and 5 μm or less. For example, the thickness of the alignment layer 4 may be 10 nm or more and 5000 nm or less, 10 nm or more and 1000 nm or less, 10 nm or more and 500 nm or less, or 10 nm or more and 300 nm or less. For example, the thickness of the polarizer layer 5 may be 0.5 μm or more and 10 μm or less, 0.5 μm or more and 8 μm or less, or 1 μm or more and 5 μm or less. For example, the thickness of the second protective layer 6 may be 0.1 μm or more and 13 μm or less, 0.3 μm or more and 8 μm or less, or 0.5 μm or more and 5 μm or less. For example, the thickness of the first adhesive layer 7 may be 0.1 μm or more and 15 μm or less, 0.5 μm or more and 10 μm or less, or 1 μm or more and 5 μm or less. For example, the thickness of the retardation layer 8 (other resin layer) may be 0.1 μm or more and 10 μm or less, 0.5 μm or more and 8 μm or less, or 1 μm or more and 6 μm or less. For example, the thickness of the second adhesive layer 9 may be 0.1 μm or more and 15 μm or less, 0.5 μm or more and 10 μm or less, or 1 μm or more and 5 μm or less. For example, the thickness of the optical compensation layer 10 may be 0.1 μm or more and 10 μm or less, 0.5 μm or more and 8 μm or less, or 1 μm or more and 6 μm or less. For example, the thickness of the third protective layer 11 may be 5 μm or more and 100 μm or less. When the thicknesses of the surface treatment layer 3, the alignment layer 4, the polarizer layer 5, and the second protective layer 6 are within the above ranges, each layer is sufficiently thin, and when the substrate layer 2 is peeled off, each layer is likely to break at the ends of each layer. As a result, it is easy to remove the end piece E composed of the ends of the surface treatment layer 3, the alignment layer 4, the polarizer layer 5, and the second protective layer 6 from the optical laminate B.

[0041] (Method for manufacturing the substrate laminate A) An example of the method for manufacturing the substrate laminate A includes a step of directly laminating the surface treatment layer 3 on the surface of the substrate layer 2 to obtain a laminate, a step of winding the laminate to obtain a roll, and a step of heating at least one of a pair of opposing end faces of the roll. Both of the pair of opposing end faces of the roll may be heated. By heating the end faces of the roll, the ends of the substrate layer 2 and the surface treatment layer 3 located at the end faces of the roll are firmly fused to each other. As a result, a substrate laminate A having Ie higher than Ic can be obtained. The means for heating the end face of the roll may be a flame (e.g., a gas burner) or radiant heat (e.g., an infrared heater).

[0042] Another example of the method for manufacturing the substrate laminate A includes a step of performing corona treatment on at least one of a pair of opposing ends of the substrate layer 2, and a step of directly laminating the surface treatment layer 3 on the surface of the substrate layer 2 after the corona treatment. The corona treatment may be performed on both of the pair of opposing ends of the substrate layer 2. By the corona treatment, the surface of the end of the substrate layer 2 is modified. By laminating the surface treatment layer 3 on the substrate layer 2 whose end surface has been modified, the surface treatment layer 3 adheres firmly to the end of the substrate layer 2. As a result, a substrate laminate A having Ie higher than Ic can be obtained.

[0043] (Substrate protective layer 1, substrate layer 2, and third protective layer 11) For example, each of the protective layer 1 for the substrate, the substrate layer 2, and the third protective layer 11 may be a thermoplastic resin film selected from the group consisting of polyester resin films containing resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; cycloolefin resin films; cellulose acetate resin films containing resins such as triacetyl cellulose and diacetyl cellulose; polycarbonate resin films; acrylic resin films; methacrylic resin films; and polypropylene resin films. An adhesive layer may be formed on the surface of one pair of surfaces of the protective layer 1 for the substrate that faces the substrate layer 2.

[0044] (Surface treatment layer 3) The surface treatment layer 3 (first protective layer) protects the polarizer layer 5 (and the alignment layer 4) in each of the optical laminate B and the polarizing plate C, and suppresses the diffusion of the dichroic dye from the polarizer layer 5. For example, the surface treatment layer 3 may be a cured product of an ultraviolet curable resin. For example, the ultraviolet curable resin may be at least one selected from the group consisting of acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. Inorganic fine particles, organic fine particles, or a mixture thereof may be added to the surface treatment layer 3 to improve the mechanical strength of the surface treatment layer 3. The surface treatment layer 3 may be laminated on the surface of the substrate layer 2 by a transfer method. For example, the method for forming the surface treatment layer 3 may include a step of forming a coating film containing an uncured ultraviolet curable resin on the surface of a substrate film covered with a release agent, a step of transferring the coating film from the substrate film to the surface of the substrate layer 2, and a step of curing the coating film transferred to the surface of the substrate layer 2 by irradiation with ultraviolet rays.

[0045] When the surface treatment layer 3 is made of an acrylic resin cured by irradiation with ultraviolet rays and the substrate layer 2 is made of polyethylene terephthalate (PET), a substrate laminate A having Ie higher than Ic is easily formed, and each of Ie and Ic is easily controlled within the above-described numerical ranges.

[0046] (Alignment layer 4) The alignment layer 4 is a film containing a polymer compound and has a function of aligning the polymerizable liquid crystal compound constituting the polarizer layer 5 in a desired direction. For example, the alignment layer 4 may be an alignment film selected from the group consisting of an alignment film made of an alignment polymer, a photo-alignment film, and a groove alignment film.

[0047] The alignment polymer may be at least one polymer compound selected from the group consisting of polyamide having an amide bond in the molecule, gelatin having an amide bond in the molecule, polyimide having an imide bond in the molecule, polyamic acid which is a hydrolyzate of the polyimide, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylate ester.

[0048] For example, the method for forming the alignment layer 4 may include a step of forming a coating film containing an alignment polymer and a solvent on the surface of the surface treatment layer 3, a step of removing the solvent from the coating film, and a step of treating the coating film from which the solvent has been removed by a rubbing method.

[0049] The solvent used for forming the alignment layer 4 may be at least one solvent selected from the group consisting of water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene.

[0050] The photo-alignment film contains a polymer having a photoreactive group. The method for forming the photo-alignment film may include a step of forming a coating film containing a polymer or monomer having a photoreactive group and the above solvent on the surface of the surface treatment layer 3, and a step of irradiating the coating film with polarized light (preferably, polarized ultraviolet light).

[0051] The photoreactive group is a functional group that exhibits liquid crystal alignment ability by irradiation with light. For example, the photoreactive group may be a functional group that induces molecular alignment by irradiation with light. The photoreactive group may be a functional group that causes a photoreaction (isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodegradation reaction) that is the origin of the liquid crystal alignment ability. For example, the photoreactive group may be a functional group having at least one bond structure selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond).

[0052] The photoreactive group having a C=C bond may be at least one selected from the group consisting of a vinyl group, a polyene group, a stilbene group, a stilbazoyl group, a stilbazolium group, a chalcone group, and a cinnamoyl group. The photoreactive group having a C=N bond may be at least one selected from the group consisting of an aromatic Schiff base and an aromatic hydrazone. The photoreactive group having an N=N bond may be at least one selected from the group consisting of an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and an azoxybenzene-type structure. The photoreactive group having a C=O bond may be at least one selected from the group consisting of a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. The polymer having a photoreactive group may have at least one substituent selected from the group consisting of an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.

[0053] A groove alignment film is a film having a plurality of uneven patterns or a plurality of grooves formed on its surface. The polymerizable liquid crystal compound constituting the polarizer layer 5 is aligned in a predetermined direction along the uneven pattern or the plurality of grooves.

[0054] The method for forming a groove alignment film may include a step of forming an uneven pattern on the surface of a photosensitive polyimide film by exposing the surface of the photosensitive polyimide film using an exposure mask having a plurality of slits and developing and rinsing processes following the exposure. The method for forming a groove alignment film may include a step of forming a coating film containing an uncured ultraviolet curable resin on the surface of a plate-shaped master having grooves, a step of transferring the coating film from the master to the surface of the surface treatment layer 3, and a step of curing the coating film transferred to the surface of the surface treatment layer 3 by irradiating with ultraviolet rays. The method for forming a groove alignment film may include a step of forming a coating film containing an uncured ultraviolet curable resin on the surface of the surface treatment layer 3, a step of pressing the surface of a roll having a plurality of grooves against the surface of the coating film, and a step of curing the coating film having grooves formed on the surface by irradiating with ultraviolet rays.

[0055] (Polarizer layer 5) The polarizer layer 5 contains a polymer of a polymerizable liquid crystal compound and a dichroic dye. The method for forming the polarizer layer 5 may include a step of applying a raw material for a polarizer layer containing a polymerizable liquid crystal compound, a dichroic dye, and a solvent onto the surface of the alignment layer 4 to form a coating film, and a step of polymerizing the polymerizable liquid crystal compound in the coating film. For example, the "composition for forming a polarizing film" described in JP-A-2017-83843 may be used as the raw material for the polarizer layer.

[0056] The polymerizable liquid crystal compound is a compound having a polymerizable group and exhibiting liquid crystallinity. The polymerizable group is a group involved in a polymerization reaction. For example, the polymerizable group may be a photopolymerizable group. The photopolymerizable group may be a group involved in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator. For example, the polymerizable group may be at least one functional group selected from the group consisting of a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. The polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal.

[0057] The polymerizable liquid crystal compound may be a thermotropic liquid crystal compound that forms a nematic liquid crystal phase, a thermotropic liquid crystal compound that forms a smectic liquid crystal phase, or a thermotropic liquid crystal compound that forms a high-order smectic liquid crystal phase. The polymerizable liquid crystal compound may be a thermotropic liquid crystal compound that forms a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, or a smectic L phase. The X-ray diffraction pattern of the polarizer layer 5 having excellent polarization performance includes a peak of diffracted X-rays derived from a high-order structure such as a hexatic phase and a crystal phase. The peak of diffracted X-rays derived from the high-order structure may be a peak derived from a periodic structure of molecular orientation. The periodic interval of the molecular orientation may be 3 to 6 Å.

[0058] The polymerizable liquid crystal compound may be at least one compound represented by the following chemical formula A. U 1 -V 1 -W 1 -X 1 -Y 1 -X 2 -Y 2 -X 3 -W 2 -V 2 -U 2 (A) X 1 , X 2 and X 3Each independently represents a 1,4-phenylene group which may have a substituent, or a cyclohexane-1,4-diyl group which may have a substituent. However, X 1 X 2 and X 3 at least one of which is a 1,4-phenylene group which may have a substituent. -CH2- constituting the cyclohexane-1,4-diyl group may be substituted with -O-, -S- or -NR-. R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group. Y 1 and Y 2 Each independently represents -CH2CH2-, -CH2O-, -COO-, -OCOO-, a single bond, -N=N-, -CR a =CR b -, -C≡C- or -CR a =N-. R a and R b Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. U 1 represents a hydrogen atom or a polymerizable group. U 2 represents a polymerizable group. W 1 and W 2 Each independently represents a single bond, -O-, -S-, -COO- or -OCOO-. V 1 and V 2 Each independently represents an alkanediyl group having 1 to 20 carbon atoms and which may have a substituent. -CH2- constituting the alkanediyl group may be substituted with -O-, -S- or -NH-.

[0059] The dichroic dye has an absorption maximum wavelength (λ MAXIt may be a dye having . For example, the dichroic dye may be at least one dye selected from the group consisting of acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes. For example, the azo dye may be at least one dye selected from the group consisting of monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes. The polarizer layer 5 may contain two or more dichroic dyes (particularly azo dyes), or three or more dichroic dyes (particularly azo dyes).

[0060] For example, the azo dye may be a compound represented by the following chemical formula B. A 1 (-N=N-A 2 ) p -N=N-A 3 (B) A 1 and A 3 Each independently represents a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. A 2 represents a 1,4-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic group which may have a substituent. p represents an integer from 1 to 4. When p is 2 or more, the plurality of A 2 may be the same as each other, and the plurality of A 2 may be different from each other.

[0061] The solvent used for the raw material of the polarizer layer may be at least one solvent selected from the group consisting of alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorine-containing solvents such as chloroform and chlorobenzene.

[0062] The raw material for the polarizer layer may contain a polymerization initiator (such as a photoinitiator). For example, the polymerization initiator may be at least one compound selected from the group consisting of benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts.

[0063] In addition to the polymerizable liquid crystal compound, dichroic dye, solvent, and polymerization initiator, the raw material for the polarizer layer may further contain a sensitizer, polymerization inhibitor, leveling agent, and reactive additive.

[0064] The "photoalignment layer" described in International Publication No. 2020 / 122117 may be used as the alignment layer 4, and the "liquid crystal layer" described in the same document may be used as the polarizer layer 5. The "photoalignment film" described in International Publication No. 2020 / 179864 may be used as the alignment layer 4, and the "polarization layer" described in the same document may be used as the polarizer layer 5.

[0065] (Second protective layer 6) For example, the second protective layer 6 may contain a polyvinyl alcohol-based resin. For example, the polyvinyl alcohol-based resin may be at least one polyvinyl alcohol selected from the group consisting of partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol. The method for forming the second protective layer 6 may include a step of forming a coating film containing a polyvinyl alcohol-based resin and water on the surface of the polarizer layer 5, and a step of drying the coating film by heating the coating film.

[0066] The second protective layer 6 may contain a cured product of a cationically polymerizable compound such as an epoxy compound, an oxetane compound, and a vinyl compound. The second protective layer 6 may also contain a cured product of a radically polymerizable compound.

[0067] (First adhesive layer 7 and second adhesive layer 9) Each of the first adhesive layer 7 and the second adhesive layer 9 may contain a polymer (cured product) of at least one polymerizable compound selected from the group consisting of (meth)acrylate compounds such as polyfunctional acrylate compounds and polyfunctional methacrylate compounds; urethane (meth)acrylate compounds such as polyfunctional urethane acrylate compounds and polyfunctional urethane methacrylate compounds; epoxy (meth)acrylate compounds such as polyfunctional epoxy acrylate compounds and polyfunctional epoxy methacrylate compounds; carboxyl group-modified epoxy acrylate compounds, carboxyl group-modified epoxy methacrylate compounds, polyester acrylate compounds, polyester methacrylate compounds, epoxy compounds having an epoxy group, oxetane compounds having an oxetanyl group, and vinyl compounds. The polymerization method (curing method) of the polymerizable compound may be irradiation with light (such as ultraviolet light) or heating. An uncured first adhesive layer 7 containing a polymerizable compound and a solvent may be formed on the surface of the second protective layer 6 or the retardation layer 8, the retardation layer 8 may be bonded to the surface of the second protective layer 6 via the uncured first adhesive layer 7, and the first adhesive layer 7 may be cured immediately after the bonding of the retardation layer 8. An uncured second adhesive layer 9 containing a coincidence compound and a solvent may be formed on the surface of the retardation layer 8 or the optical compensation layer 10. The optical compensation layer 10 may be bonded to the surface of the retardation layer 8 via the uncured second adhesive layer 9, and the second adhesive layer 9 may be cured immediately after the bonding of the optical compensation layer 10. The composition of the first adhesive layer 7 may be the same as that of the second adhesive layer 9. The composition of the first adhesive layer 7 may be different from that of the second adhesive layer 9.

[0068] (Retardation layer 8 and optical compensation layer 10) The optical compensation layer 10 may be paraphrased as a retardation layer different from the retardation layer 8. For example, each of the retardation layer 8 and the optical compensation layer 10 may be at least one selected from the group consisting of positive A plates such as λ / 4 plates and λ / 2 plates, and positive C plates (optically oriented material vertically oriented films). Each of the retardation layer 8 and the optical compensation layer 10 may be formed by applying the above-mentioned polymerizable liquid crystal compound to an alignment layer different from the alignment layer 4. The method of forming the alignment layer for forming each of the retardation layer 8 and the optical compensation layer 10 may be the same as that of the alignment layer 4 for the polarizer layer 5.

[0069] The present invention is not necessarily limited to the above-described embodiments. Various modifications of the present invention are possible without departing from the spirit of the present invention, and such modified examples are also included in the present invention.

[0070] For example, the method for manufacturing the polarizing plate C according to the second embodiment of the present invention includes a first step of directly laminating the surface treatment layer 3 on the surface of the base material layer 2, a second step of laminating the polarizer layer 5 directly or indirectly on the surface of the surface treatment layer 3, and another resin layer directly or indirectly on the surface of the polarizer layer 5 via the first adhesive layer 7. A third step of laminating, a fourth step of simultaneously heating the ends of the base material layer 2 and the surface treatment layer 3 after the third step, and a fifth step of peeling the base material layer 2 after the fourth step. In the second embodiment, the polarizer layer 5 contains a polymer of a polymerizable liquid crystal compound and a dichroic dye. In the second embodiment, the other resin layer may be the retardation layer 8, the optical compensation layer 10, or the third protective layer 11. In the fourth step of simultaneously heating the respective ends of the base material layer 2 and the surface treatment layer 3, the respective ends of the base material layer 2 and the surface treatment layer 3 are fused to each other. As a result, the peel strength of the end of the base material layer 2 with respect to the end of the surface treatment layer 3 is increased. On the other hand, in portions other than the respective ends of the base material layer 2 and the surface treatment layer 3, the peel strength of the base material layer 2 with respect to the surface treatment layer 3 does not change. Therefore, by the fourth step, a base material laminate A in which Ie is higher than Ic can be obtained in the same manner as in the first embodiment described above. In other words, in the second embodiment, by the steps performed before the fifth step, an optical laminate B can be obtained in the same manner as in the first embodiment. Therefore, in the same manner as in the first embodiment, also in the second embodiment, by the fifth step of peeling the base material layer 2, the end piece E adhered to the end of the base material layer 2 can be easily removed from the end of the optical laminate B.

[0071] The polarizing plate according to the present invention may be a circularly polarizing plate or an elliptically polarizing plate including one or more retardation layers. The polarizing plate according to the present invention may also be a linearly polarizing plate that does not include a retardation layer.

Industrial Applicability

[0072] For example, the base material laminate and the optical laminate according to one aspect of the present invention may be used in the manufacture of a polarizing plate.

Explanation of Signs

[0073] 1... Protective layer for base material, 2... Base material layer, 3... Surface treatment layer (first protective layer), 4... Alignment layer, 5... Polarizer layer, 6... Second protective layer, 7... First adhesive layer, 8... Retardation layer (other resin layer), 9... Second adhesive layer, 10... Optical compensation layer (another retardation layer), 11... Third protective layer, A... Base material laminate, B... Optical laminate, C... Polarizing plate.

Claims

1. A base material laminate including a base material layer and a surface treatment layer directly laminated on the surface of the base material layer, An alignment layer directly laminated on the surface of the surface treatment layer, A polarizer layer directly laminated on the surface of the alignment layer, An optical laminate comprising: The surface treatment layer is a cured product of an ultraviolet curable resin, The thickness of the surface treatment layer is 0.1 μm or more and 13 μm or less, The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye, The base material laminate includes a pair of end portions facing each other in a direction substantially parallel to the surface of the base material layer, and a central portion located between the pair of end portions, The peel strength of the base material layer with respect to the surface treatment layer at at least one of the end portions is represented as Ie, The peel strength of the base material layer with respect to the surface treatment layer at the central portion is represented as Ic, The Ie is higher than the Ic, The end portion of the surface treatment layer is in close contact with the end portion of the base material layer at the end portion of the base material laminate, An end piece including the end portion of the surface treatment layer, the end portion of the alignment layer directly overlapping the end portion of the surface treatment layer, and the end portion of the polarizer layer directly overlapping the end portion of the alignment layer is separated from the optical laminate together with the base material layer as the base material layer is peeled off from the optical laminate. Optical laminate.

2. The Ie is higher than the Ic and is 0.40 N / 25 mm or more, The Ic is lower than the Ie and is 0.55 N / 25 mm or less, The optical laminate according to Claim 1.

3. The base material layer is a thermoplastic resin film of one kind selected from the group consisting of a polyester-based resin film, a cycloolefin-based resin film, a cellulose acetate-based resin film, a polycarbonate-based resin film, an acrylic-based resin film, a methacrylic-based resin film, and a polypropylene-based resin film. The optical laminate according to Claim 1 or 2.

4. The alignment layer is a film containing a polymer compound, and aligns the polymerizable liquid crystal compound constituting the polarizer layer. The optical laminate according to any one of Claims 1 to 3.

5. The alignment layer aligns the polymerizable liquid crystal compound constituting the polarizer layer, The alignment layer is an alignment film of one kind selected from the group consisting of an alignment film made of an alignment polymer, a photo-alignment film, and a groove alignment film. The alignment polymer is at least one polymer compound selected from the group consisting of polyamide having an amide bond in the molecule, gelatin having an amide bond in the molecule, polyimide having an imide bond in the molecule, polyamic acid which is a hydrolyzate of the polyimide, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylate ester. The photoalignment film contains a polymer having a photoreactive group. The photoreactive group is a functional group that exhibits liquid crystal alignment ability upon irradiation with light. The photoreactive group is a functional group having at least one bond structure selected from the group consisting of a carbon-carbon double bond, a carbon-nitrogen double bond, a nitrogen-nitrogen double bond, and a carbon-oxygen double bond. The groove alignment film is a film having a plurality of concavo-convex patterns or a plurality of grooves formed on the surface. The polymerizable liquid crystal compound constituting the polarizer layer is aligned in a predetermined direction along the concavo-convex pattern or the plurality of grooves. The optical laminate according to any one of claims 1 to 3.

6. The thickness of the base material layer is 5 μm or more and 100 μm or less. The thickness of the alignment layer is 10 nm or more and 5000 nm or less. The thickness of the polarizer layer is 0.5 μm or more and 10 μm or less. The optical laminate according to any one of claims 1 to 5.

7. In a direction substantially parallel to the surface of the surface treatment layer, at least one end of the base material laminate is located outside the region surrounded by the outer periphery of the polarizer layer. The optical laminate according to any one of claims 1 to 6.

8. It includes an adhesive layer and another resin layer. The adhesive layer is laminated directly or indirectly on the surface of the polarizer layer. The other resin layer is laminated directly on the surface of the adhesive layer. The optical laminate according to any one of claims 1 to 7.

9. The other resin layer is a retardation layer. The optical laminate according to claim 8.

10. In a direction substantially parallel to the surface of the surface treatment layer, at least one end of the base material laminate is located outside the region surrounded by the outer periphery of the adhesive layer. The optical laminate according to claim 8 or 9.

11. In a direction substantially parallel to the surface of the surface treatment layer and substantially perpendicular to the outer periphery of the adhesive layer, the width of at least one of the ends of the base material laminate is 0.1 mm or more and less than 55 mm. The optical laminate according to claim 10.

12. In a direction substantially parallel to the surface of the surface treatment layer, at least one end of the polarizer layer is located outside the region surrounded by the outer periphery of the adhesive layer. The optical laminate according to any one of claims 8 to 11.

13. A method for manufacturing a base material laminate, comprising: a step of directly laminating a surface treatment layer on the surface of a base material layer to obtain a laminate; a step of winding the laminate to obtain a roll; a step of heating at least one of the pair of opposing end faces of the roll; and the base material laminate includes the base material layer and the surface treatment layer directly laminated on the surface of the base material layer; the surface treatment layer is a cured product of an ultraviolet curable resin; the thickness of the surface treatment layer is 0.1 μm or more and 13 μm or less; the base material laminate includes a pair of opposing ends in a direction substantially parallel to the surface of the base material layer and a central portion located between the pair of ends; the peel strength of the base material layer with respect to the surface treatment layer at at least one of the ends is represented as Ie; the peel strength of the base material layer with respect to the surface treatment layer at the central portion is represented as Ic; the Ie is higher than the Ic; the end of the surface treatment layer is in close contact with the end of the base material layer at the end of the base material laminate; the end of the surface treatment layer separates from the surface treatment layer together with the base material layer as the base material layer peels off from the surface treatment layer. A method for manufacturing a base material laminate.

14. The Ie is higher than the Ic and is 0.40 N / 25 mm or more, the Ic is lower than the Ie and is 0.55 N / 25 mm or less. The method for manufacturing a base material laminate according to claim 13.

15. The base material layer is a thermoplastic resin film selected from the group consisting of a polyester-based resin film, a cycloolefin-based resin film, a cellulose acetate-based resin film, a polycarbonate-based resin film, an acrylic-based resin film, a methacrylic-based resin film, and a polypropylene-based resin film. The method for manufacturing a base material laminate according to claim 13 or 14.

16. The thickness of the base material layer is 5 μm or more and 100 μm or less. A method for manufacturing a base material laminate according to any one of claims 13 to 15.

17. A method for manufacturing a polarizing plate, comprising a step of peeling the base material layer from the optical laminate according to any one of claims 1 to 12. A method for manufacturing a polarizing plate.

18. A step of directly laminating a surface treatment layer on the surface of the base material layer; A step of laminating a polarizer layer directly or indirectly on the surface of the surface treatment layer; A step of laminating another resin layer directly or indirectly on the surface of the polarizer layer via an adhesive layer; After the step of laminating the other resin layer directly or indirectly on the surface of the polarizer layer via the adhesive layer, a step of simultaneously heating the ends of the base material layer and the surface treatment layer; After the step of simultaneously heating the ends of the base material layer and the surface treatment layer, a step of peeling the base material layer; comprising; By the step of simultaneously heating the ends of the base material layer and the surface treatment layer, an optical laminate including a base material laminate including the base material layer and the surface treatment layer, the polarizer layer, the adhesive layer, and the other resin layer is obtained; By the step of simultaneously heating the ends of the base material layer and the surface treatment layer, the peel strength of the end of the base material layer with respect to the end of the surface treatment layer is increased; The end of the surface treatment layer is in close contact with the end of the base material layer; By the step of peeling the base material layer, an end piece including the end of the surface treatment layer and the end of the polarizer layer is separated from the optical laminate together with the base material layer as the base material layer is peeled from the optical laminate; The surface treatment layer is a cured product of an ultraviolet curable resin; The thickness of the surface treatment layer is 0.1 μm or more and 13 μm or less; The polarizer layer includes a polymer of a polymerizable liquid crystal compound and a dichroic dye; A method for manufacturing a polarizing plate.

19. The other resin layer is a retardation layer; The method for manufacturing a polarizing plate according to claim 18.

20. The base material laminate includes a pair of ends facing each other in a direction substantially parallel to the surface of the base material layer, and a central portion located between the pair of ends; The peel strength of the base material layer with respect to the surface treatment layer at at least one end of the base material laminate is represented as Ie; The peel strength of the base material layer with respect to the surface treatment layer at the central portion of the base material laminate is represented as Ic; The Ie is higher than the Ic; The method for manufacturing a polarizing plate according to claim 18 or 19. Claim 21: The Ie is higher than the Ic and is 0.40 N / 25 mm or more, The Ic is lower than the Ie and is 0.55 N / 25 mm or less, The method for manufacturing a polarizing plate according to claim 20. Claim 22: The base material layer is a thermoplastic resin film selected from the group consisting of a polyester-based resin film, a cycloolefin-based resin film, a cellulose acetate-based resin film, a polycarbonate-based resin film, an acrylic-based resin film, a methacrylic-based resin film, and a polypropylene-based resin film. The method for manufacturing a polarizing plate according to any one of claims 18 to 21. Claim 23: The thickness of the base material layer is 5 μm or more and 100 μm or less, The thickness of the polarizer layer is 0.5 μm or more and 10 μm or less, The method for manufacturing a polarizing plate according to any one of claims 18 to 22.

Images