JP2023040681A - Base material laminate body, optical laminate body, method for manufacturing base material laminate body, and method for manufacturing polarizer - Google Patents

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

The present disclosure relates to a substrate laminate, an optical laminate, a method for producing a substrate laminate, and a method for producing a polarizing plate.

Polarizing plates are used in image display devices (liquid crystal displays, organic EL displays, etc.) such as televisions, computers, smart phones, smart watches, mobile game machines, and instrument panels of vehicles. A 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.)

JP 2019-028133 A JP 2017-83843 A WO2020/122117 WO2020/179864

A method for producing a polarizing plate includes, for example, a step of directly laminating a surface treatment layer (hard coat layer, etc.) on a substrate layer (PET film, etc.) to obtain a substrate laminate, and a step of laminating a polarizer layer on a substrate. A step of directly or indirectly laminating a surface treatment layer contained in the body, and a step of directly or indirectly laminating another resin layer (such as a retardation layer) on the polarizer layer via an adhesive layer; Prepare. An optical layered body is produced by at least these steps. Then, the polarizing plate is obtained by peeling the base layer from the optical layered body.

The adhesive layer desirably covers the entire surface of the adherend layer (for example, the polarizer layer, the overcoat layer covering the polarizer layer, or the retardation layer) on which the adhesive layer is directly laminated. However, the edge of the surface of the adherend layer tends to be difficult to cover with the adhesive layer. A portion not covered with the adhesive layer at the edge of the surface of the adherend layer is referred to as an "uncovered portion". A plurality of layers (e.g., a surface treatment layer and a polarizer layer) laminated between the adhesive layer and the base layer, and the portions indirectly overlapping with the uncovered portions at the ends of each are called " constitute an "end piece". In other words, the end piece is a portion that is not directly or indirectly fixed by an adhesive layer at the end of the above optical layered body 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 optical laminate during the manufacturing process of the polarizing plate. A 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 included in the optical layered body contains the polymer of the polymerizable liquid crystal compound and the dichroic dye, the end pieces are likely to fall off from the optical layered body. The edge pieces that fall off the optical laminate contaminate the polarizer production line. As a result, the end pieces are likely to be mixed into the polarizing plate as foreign matter, degrading the quality of the polarizing plate. By cutting the ends of the optical stack prior to peeling the substrate layer from the optical stack, the edge pieces can be removed from the optical stack. However, when the end portion of the optical layered body is cut off, the number of man-hours required for manufacturing the polarizing plate increases, and the productivity of the polarizing plate decreases. Furthermore, when the ends of the optical stack are cut off, the normal ends that do not need to be cut are likely to be cut off along with the end piece, thus wasting the raw material that makes up the ends of the optical stack. As a result, the productivity of the polarizing plate is lowered.

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

A substrate laminate according to one aspect of the present invention includes a substrate layer and a surface treatment layer directly laminated on the surface of the substrate layer. The substrate laminate includes a pair of end portions facing each other in a direction substantially parallel to the surface of the substrate layer, and a center portion positioned between the pair of end portions. The peel strength of the base material layer to the surface treatment layer at at least one end of the base material laminate is expressed as Ie. The peel strength of the substrate layer to the surface treatment layer in the central portion of the substrate laminate is represented by Ic. Ie is higher than Ic.

Ie may be higher than Ic and equal to or greater than 0.40 N/25 mm. Ic may be lower than Ie and no greater than 0.55N/25mm.

An optical layered body according to one aspect of the present invention includes the substrate layered body described above and a polarizer layer. The polarizer layer is laminated directly or indirectly on the surface of the surface treatment layer included in the substrate laminate. The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye.

In a direction substantially parallel to the surface of the surface treatment layer, at least one end of the substrate laminate may be positioned outside the region surrounded by the outer periphery of the polarizer layer.

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

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

In a direction parallel to the surface of the surface treatment layer, at least one end of the substrate laminate may be located outside the area surrounded by the outer periphery of the adhesive layer.

The width of at least one end of the substrate laminate may be 0.1 mm or more and less than 55 mm in a direction substantially parallel to the surface of the surface treatment layer and substantially perpendicular to the outer periphery of the adhesive layer.

At least one end of the polarizer layer may be positioned outside the area surrounded by the outer periphery of the adhesive layer in a direction parallel to the surface of the surface treatment layer.

A method for producing a substrate laminate according to one aspect of the present invention is a method for producing the above-described substrate laminate, comprising a step of directly laminating a surface treatment layer on the surface of the substrate layer to obtain a laminate; A step of winding a laminate to obtain a roll, and a step of heating at least one of a pair of opposing end faces of the roll.

A method for manufacturing a substrate laminate according to another aspect of the present invention is a method for manufacturing the above-described substrate laminate, wherein at least one of the pair of opposing ends of the substrate layer has a corona and a step of directly laminating the surface-treated layer on the surface of the substrate layer after the corona treatment.

A method for manufacturing a polarizing plate according to one aspect of the present invention includes a step of peeling off a substrate layer from the optical layered body.

A method for producing 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 substrate layer, and a step of directly or indirectly laminating a polarizer layer on the surface of the surface treatment layer. a step of directly or indirectly laminating another resin layer on the surface of the polarizer layer through the adhesive layer; and laminating the other resin layer onto the surface of the polarizer layer through the adhesive layer. After the step of directly or indirectly laminating the base layer and the surface treatment layer, after the step of simultaneously heating the ends of the base layer and the surface treatment layer, and the step of heating the ends of the base layer and the surface treatment layer at the same time, the base and detaching the material layer. The step of simultaneously heating the ends of the base layer and the surface treatment layer increases the peel strength of the ends of the base layer with respect to the ends of the surface treatment layer. The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye.

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.

According to one aspect of the present invention, there are provided a substrate laminate capable of easily removing an end piece of an optical laminate produced in the manufacturing process of a polarizing plate, an optical laminate, a method for producing the substrate laminate, And a method for manufacturing a polarizing plate is provided.

FIG. 1 shows a cross section of a substrate laminate according to one embodiment of the present invention, the cross section is substantially parallel to the stacking direction of the substrate laminate, and the substrate layer included in the substrate laminate is approximately perpendicular to the surface of the FIG. 2 shows a cross section of an optical layered body according to an embodiment of the present invention, the section is substantially parallel to the lamination direction of the optical layered body, and Almost vertical. FIG. 3 shows the surface of the surface treatment layer contained in the optical laminate according to one embodiment of the present invention, the outer circumference of the polarizer layer overlapping the surface of the surface treatment layer, and the outer circumference of the adhesive layer overlapping the surface of the surface treatment layer. show. FIG. 4 shows a cross section of the polarizing plate obtained by peeling off the base material layer from the optical layered body according to one embodiment of the present invention. and substantially perpendicular to the surfaces of the surface treatment layers included in the optical layered body and the polarizing plate.

A preferred embodiment (first embodiment) of the present invention will be described below with reference to the drawings. In the drawings, similar components are provided with similar reference numerals. The present invention is not limited to the following embodiments. X, Y and Z shown in each figure mean three coordinate axes orthogonal to each other. The directions indicated by the XYZ coordinate axes in each figure are common to each figure. The X-axis direction can be rephrased as the width direction of each layer included in each of the substrate laminate, the optical laminate, and the polarizing plate. The Y-axis direction may be rephrased as the longitudinal direction or the transport direction of each layer included in the substrate laminate, the optical laminate, and the polarizing plate. The Z-axis direction may be rephrased as the lamination direction of the substrate laminate, the optical laminate, and the polarizing plate.

(Base material laminate, optical laminate, polarizing plate, and method for producing polarizing plate)
As shown in FIG. 1 , the substrate laminate A according to the first embodiment includes at least a substrate layer 2 and a surface treatment layer 3 directly laminated on the surface of the substrate layer 2 . Each of the substrate layer 2 and the surface treatment layer 3 may be a layer containing a resin (polymer compound) to be described later. The surface treatment layer 3 may be called 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 substrate protective layer 1 (substrate protective film) may be directly laminated on the surface of the substrate layer 2 located behind the surface on which the surface treatment layer 3 is laminated. The substrate 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 substrate layer 2, and a central portion AC positioned between the pair of end portions AE. . The central portion AC may be rephrased as a portion located between the pair of end portions AE of the substrate laminate A in the cross section of the substrate laminate A substantially perpendicular to the surface of the substrate layer 2 . The peel strength of the base material layer 2 to the surface treatment layer 3 at at least one end AE of the base material laminate A is expressed as Ie. The peel strength of the base material layer 2 to the surface treatment layer 3 at both ends AE of the base material laminate A may be represented as Ie. The peel strength of the substrate layer 2 to the surface treatment layer 3 in the central portion AC of the substrate laminate A is represented by Ic. Ie is higher than Ic. The peel strength of the base layer 2 to the surface treatment layer 3 at one end AE of the base laminate A is the peel strength of the base layer 2 to the surface treatment layer 3 at the other end AE of the base laminate A. may be equal to The peel strength of the base layer 2 to the surface treatment layer 3 at one end AE of the base laminate A is the peel strength of the base layer 2 to the surface treatment layer 3 at the other end AE of the base laminate A. may differ from The unit of peel strength is N/25 mm. For example, the peel strength is measured by a 180-degree peel test conforming to Japanese Industrial Standards (JIS Z 0237). The base material layer 2 can be easily peeled off from the surface treatment layer 3 located in the central part AC of the base material laminate A. The surface treatment layer 3 positioned in the central portion AC of the base material laminate A is less likely to be damaged when the base material layer 2 is peeled off.

The optical layered body according to the first embodiment includes at least a substrate layered body A and a polarizer layer. A polarizer layer is laminated|stacked directly or indirectly on the surface of the surface treatment layer contained in a base-material laminated body. The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye.

The optical layered body may further include an adhesive layer and another resin layer in addition to the substrate layered body A and the polarizer layer. An adhesive layer (first adhesive layer described later) is laminated directly or indirectly on the surface of the polarizer layer. Another 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 (third protective layer to be described later).
When arbitrary two layers constituting the optical laminate are denoted as A layer and B layer, the B layer directly laminated on the A layer is the B layer laminated on the A layer without interposing another layer. means The B layer indirectly laminated on the A layer means the B layer laminated on the A layer via another layer.

FIG. 2 shows an example of the layered structure of the optical layered body. However, the laminated structure of the optical laminated body according to the first embodiment is not limited to the structure shown in FIG. The optical layered body B shown in FIG. A polarizer layer 5 directly laminated on the surface of 4, a second protective layer 6 (overcoat layer) directly laminated on the surface of the polarizer layer 5, and a second protective layer 6 directly laminated on the surface One adhesive layer 7, a retardation layer 8 (another resin layer) directly laminated on the surface of the first adhesive layer 7, and 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 layered body may be substantially uniform. The shape of the optical layered body B and each layer in the direction substantially perpendicular to the layering direction of the optical layered body B (thickness direction of the polarizer layer 5) may be substantially the same as the shape of the screen of the image display device. For example, the shape of the optical layered body B and each layer in a direction substantially perpendicular to the layering direction of the optical layered body B (thickness direction of the polarizer layer 5) may be rectangular (rectangular or square). However, the shape of the optical layered body B and each layer in the direction substantially perpendicular to the layering direction of the optical layered body B (thickness direction of the polarizer layer 5) is not limited. One or more notches may be formed in the edge of the optical stack B. FIG. One or more through-holes may be formed in the optical laminate B.

As shown in FIGS. 2 and 3, in a direction (X-axis direction) substantially parallel to the surface of the surface treatment layer 3, part or all of one end AE of the substrate laminate A is the first adhesion It may be located outside the area surrounded by the outer periphery 7c of the agent layer 7. FIG. That is, at least one end AE of the substrate 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 . In a direction substantially parallel to the surface of the surface treatment layer 3, both ends AE of the base material laminate A are partially or entirely outside the area surrounded by the outer periphery 7c of the first adhesive layer 7. may be located.

As shown in FIGS. 2 and 3, in the direction substantially parallel to the surface of the surface treatment layer 3, at least one end AE of the substrate laminate A is a region surrounded by the outer periphery 5c of the polarizer layer 5. may be located outside the That is, at least one end AE of the substrate laminate A may protrude beyond the end of the polarizer layer 5 in a direction substantially parallel to the surface of the surface treatment layer 3 . In the direction substantially parallel to the surface of the surface treatment layer 3, both ends AE of the base material laminate A are partially or entirely located outside the region surrounded by the outer periphery 5c of the polarizer layer 5. you can

As shown in FIGS. 2 and 3 , in the direction substantially parallel to the surface of the surface treatment layer 3 , part or all of at least one end of the polarizer layer 5 extends from the outer periphery 7 c of the first adhesive layer 7 . may be located outside the area enclosed by That is, at least one end of the polarizer layer 5 may protrude more than the end of the first adhesive layer 7 in a direction substantially parallel to the surface of the surface treatment layer 3 . In a direction substantially parallel to the surface of the surface treatment layer 3, both ends of the polarizer layer 5 are partially or wholly located outside the region surrounded by the outer periphery 7c of the first adhesive layer 7. good.

As shown in FIG. 2 , at least one end of the alignment layer 4 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 . Both ends of the alignment layer 4 may protrude beyond the ends of the first adhesive layer 7 in a direction substantially parallel to the surface of the surface treatment layer 3 .

As shown in FIG. 2 , at least one end of the second protective layer 6 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 . Both ends of the second protective layer 6 may protrude beyond the ends of the first adhesive layer 7 in a direction substantially parallel to the surface of the surface treatment layer 3 .

Both ends of the second protective layer 6 that protrude beyond the ends of the first adhesive layer 7 in the direction parallel to the surface of the surface treatment layer 3 are a pair of uncovered portions that are not covered with the first adhesive layer 7. is. Both ends of each of the surface treatment layer 3 (first protective layer), the orientation layer 4, and the polarizer layer 5 laminated between the first adhesive layer 7 and the base layer 2 are a pair of uncovered portions (Both ends of the second protective layer 6) are indirectly overlapped. In other words, both ends of the surface treatment layer 3, the orientation layer 4, the polarizer layer 5 and the second protective layer 6 are aligned with the ends of the first adhesive layer 7 in the direction parallel to the surface of the surface treatment layer 3. stands out more than Therefore, both ends of each of the surface treatment layer 3, the alignment layer 4, and the polarizer layer 5 form a pair of end pieces E together with a pair of uncoated portions. Since the pair of end pieces E are not fixed by the first adhesive layer 7, they are likely to come off from the optical layered body B in the manufacturing process of the polarizing plate.

As shown in FIG. 4, the method for manufacturing the polarizing plate C includes a step of peeling off the substrate layer 2 (and the substrate protective layer 1) from the optical layered body B described above.

A pair of layers in contact with each other between the first adhesive layer 7 and the substrate 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 The layers 6) are firmly adhered to each other during these lamination processes. In other words, the pair of layers that are in contact with each other between the first adhesive layer 7 and the base material layer 2 are difficult to separate from each other. In contrast, the peel strength Ic of the substrate layer 2 to the surface treatment layer 3 in the center AC of the substrate laminate A is sufficiently low. That is, the central portion of the base material layer 2 is easily peeled off from the surface treatment layer 3 .
On the other hand, the peel strength Ie of the substrate layer 2 to the surface treatment layer 3 at each of the end portions AE of the substrate laminate A is higher than Ic. That is, both ends of the base material layer 2 are in closer contact with the surface treatment layer 3 than the central part of the base material layer 2 . That is, both ends of the base material layer 2 are difficult to separate from the surface treatment layer 3 . Therefore, as the central portion of the substrate layer 2 is peeled off from the surface treatment layer 3, the pair of end pieces E adhered to both ends of the substrate layer 2 are separated from the optical layered body B together with the substrate layer 2. It can be easily separated from the ends.
The laminate structure of the polarizing plate C obtained by peeling the substrate layer 2 (and the substrate protective layer 1) from the optical laminate B is the substrate layer 2, the substrate protective layer 1, and the end piece E. , may be the same as the above laminated structure of the optical laminated body B.

According to the first embodiment, by peeling the base layer 2 from the optical layered body B, the pair of end pieces E adhered to both ends of the base layer 2 can be easily removed from the ends of the optical layered body B. can. As a result, it is possible to prevent the end piece E from falling off from the optical layered body B during the manufacturing process of the polarizing plate. By suppressing the falling off of the end piece E from the optical layered body B, the contamination of the production 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.

According to the first embodiment, in order to remove the end piece E from the optical stack B, the conventional step of cutting the end of the optical stack B before the substrate layer 2 is isolated is not necessary. . As a result, the number of man-hours required for manufacturing the polarizing plate C is reduced, and the productivity of the polarizing plate C is improved. According to the first embodiment, since it is not necessary to cut the normal end portion that does not need to be cut from the optical laminate B together with the end piece, the portion that can be used as the polarizing plate C after removal of the end piece is optical. It easily remains in the laminate B, and waste of the raw material for the polarizing plate is suppressed. As a result, the productivity of the polarizing plate C is improved.

Ie may be higher than Ic and between 0.40 N/25 mm and 1.80 N/25 mm. Ic may be lower than Ie and between 0.05 N/25 mm and 0.55 N/25 mm. The higher Ie is, the easier it is for the edge piece E to adhere to the edge of the substrate layer 2 , and the easier it is for the edge piece E to be removed from the optical layered body B by peeling off the substrate layer 2 . The lower the Ic, the easier it is to separate the base material layer 2 from the surface treatment layer 3 in the central portion of the base material laminate A, and the more the surface treatment layer 3 is prevented from being damaged due to the separation of the base material layer 2 .

As shown in FIG. 3, in a direction (X-axis direction) substantially parallel to the surface of the surface treatment layer 3 and substantially perpendicular to the outer circumference 7c of the first adhesive layer 7, at least one of the substrate laminates A The width W _AE of the end AE of may be 0.1 mm or more and less than 55 mm. Each width W _AE of at least both ends AE of the substrate laminate A may be 0.1 mm or more and less than 55 mm. When the width W AE of the end portion _AE is 0.1 mm or more, the entire end piece E easily adheres to the end portion of the base material layer 2, and the entire end piece E can be reliably removed from the optical layered body B. easy to do When the width W _AE of the edge AE is less than 55 mm, the normal edge removed from the optical stack B together with the edge piece E is sufficiently small that it can be used as a polarizer C after removing the edge piece E. parts tend to remain.

For example, the thickness of the substrate protective layer 1 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 between 10 nm and 5000 nm, between 10 nm and 1000 nm, between 10 nm and 500 nm, or between 10 nm and 300 nm.
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 (another 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 to 15 μm, 0.5 μm to 10 μm, or 1 μm to 5 μm.
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 thickness of each of the surface treatment layer 3, the alignment layer 4, the polarizer layer 5, and the second protective layer 6 is within the above range, each layer is sufficiently thin, and each layer is separated from each layer as the base layer 2 is peeled off. Easy to break at the ends. As a result, it is easy to remove from the optical layered body B the edge piece E that is composed of the edge portions of the surface treatment layer 3, the alignment layer 4, the polarizer layer 5, and the second protective layer 6, respectively.

(Manufacturing method of base material laminate A)
An example of the method for producing 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 facing the rolls. and heating at least one of the pair of end faces. Both of the pair of opposing end faces of the roll may be heated. By heating the end face of the roll, the ends of the substrate layer 2 and the surface treatment layer 3 positioned on the end face of the roll are strongly fused together. As a result, a substrate laminate A having Ie higher than Ic is obtained. The means for heating the end faces of the roll may be flame (eg gas burner) or radiant heat (eg infrared heater).

Another example of the method for producing the substrate laminate A includes a step of subjecting at least one end of a pair of opposing ends of the substrate layer 2 to corona treatment; and directly laminating on the surface of the material layer 2 . Corona treatment may be performed on both of a pair of opposing ends of the substrate layer 2 . The corona treatment modifies the surface of the edge of the base material layer 2 . By laminating the surface treatment layer 3 on the base material layer 2 whose end surface has been modified, the surface treatment layer 3 firmly adheres to the end part of the base material layer 2 . As a result, a substrate laminate A having Ie higher than Ic is obtained.

(Base Protective Layer 1, Base Layer 2 and Third Protective Layer 11)
For example, the substrate protective layer 1, the substrate layer 2, and the third protective layer 11 are polyester resin films containing resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; cyclopolyolefin resin films; A thermoplastic resin film selected from the group consisting of cellulose acetate resin films containing resins such as acetyl cellulose and diacetyl cellulose; polycarbonate resin films; acrylic resin films; methacrylic resin films; and polypropylene resin films. you can A pressure-sensitive adhesive layer may be formed on the surface facing the substrate layer 2 out of the pair of surfaces of the substrate protective layer 1 .

(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 prevents diffusion of the dichroic dye from the polarizer layer 5. Suppress. 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 in order to improve the mechanical strength of the surface treatment layer 3 . The surface treatment layer 3 may be laminated on the surface of the base material layer 2 by a transfer method. For example, the method for forming the surface treatment layer 3 includes the steps of forming a coating film containing an uncured ultraviolet curable resin on the surface of a substrate film covered with a release agent, and removing the coating film from the substrate film. A step of transferring to the surface of the material layer 2 and a step of curing the coating film transferred to the surface of the base material layer 2 by irradiation with ultraviolet rays may be included.

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

(Orientation layer 4)
The orientation layer 4 is a film containing a polymer compound, and has a function of orienting 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.

The oriented polymer includes 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, and alkyl-modified polyvinyl alcohol. , polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic acid ester.

For example, the method of forming the orientation layer 4 includes the steps of forming a coating film containing an orientation polymer and a solvent on the surface of the surface treatment layer 3, removing the solvent from the coating film, and removing the coating film from which the solvent has been removed. A step of treating by a rubbing method may be included.

Solvents used for forming the alignment layer 4 include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether. ester solvents such as 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; aliphatics such as pentane, hexane and heptane hydrocarbon solvents; 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. It may be a solvent.

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

A photoreactive group is a functional group that develops liquid crystal alignment ability by irradiating with light. For example, the photoreactive group may be a functional group that induces orientation of molecules upon exposure to light. The photoreactive group may be a functional group that causes a photoreaction (isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction) that is the origin of liquid crystal alignment ability. For example, photoreactive groups include carbon-carbon double bonds (C=C bonds), carbon-nitrogen double bonds (C=N bonds), nitrogen-nitrogen double bonds (N=N bonds), and carbon- It may be a functional group having at least one bond structure selected from the group consisting of oxygen double bonds (C═O bonds).

The photoreactive group having a C═C bond may be at least one selected from the group consisting of vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups and cinnamoyl groups. The photoreactive group having a C═N bond may be at least one selected from the group consisting of aromatic Schiff bases and aromatic hydrazones. 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 has 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. may have

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

The groove alignment film is formed by exposing the surface of the photosensitive polyimide film using an exposure mask having a plurality of slits, and developing and rinsing the film after exposure to form an uneven pattern on the surface of the photosensitive polyimide film. A forming step may be included. The method of forming the groove alignment film includes a step of forming a coating film containing an uncured ultraviolet curable resin on the surface of a plate-shaped master plate in which grooves are formed, and a step of applying the coating film from the master plate to the surface of the surface treatment layer 3. A transfer step and a step of curing the coating film transferred to the surface of the surface treatment layer 3 by irradiation with ultraviolet rays may be included. The method of forming the groove alignment film includes a step of forming a coating film containing an uncured ultraviolet curable resin on the surface of the surface treatment layer 3, and 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 the grooves formed on the surface by irradiating with ultraviolet rays.

(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 includes a step of applying a polarizer layer raw material containing a polymerizable liquid crystal compound, a dichroic dye, and a solvent to the surface of the alignment layer 4 to form a coating film; and a step of polymerizing the polymerizable liquid crystal compound. 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.

A polymerizable liquid crystal compound is a compound having a polymerizable group and exhibiting liquid crystallinity. A polymerizable group is a group that participates in a polymerization reaction. For example, the polymerizable group can be a photopolymerizable group. The photopolymerizable group may be a group that participates in a polymerization reaction by an active radical generated from a photopolymerization initiator, an acid, or the like. For example, the polymerizable group is at least one 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. may be a functional group of The polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal.

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 is a thermotropic that forms smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase or smectic L phase. It may be a liquid crystal compound. The X-ray diffraction pattern of the polarizer layer 5 having excellent polarizing performance includes diffracted X-ray peaks derived from higher-order structures such as hexatic phases and crystal phases. A diffraction X-ray peak derived from a higher-order structure may be a peak derived from a periodic structure of molecular orientation. The periodic spacing of the molecular orientation may be 3-6 Å.

The polymerizable liquid crystal compound may be at least one compound represented by the chemical formula A below.
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 ³ each independently represent an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group . However, at least one of X ¹ , X ² and X ³ is an optionally substituted 1,4-phenylene group. —CH ₂ — constituting a 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 are each independently -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, single bond, -N=N-, -CR ^a =CR ^b -, - represents C≡C- or -CR ^a =N-; R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
^U1 represents a hydrogen atom or a polymerizable group.
^U2 represents a polymerizable group.
W ¹ and W ² each independently represents a single bond, -O-, -S-, -COO- or -OCOO-.
Each of V ¹ and V ² independently represents an alkanediyl group having 1 to 20 carbon atoms and optionally having a substituent. —CH ₂ — constituting the alkanediyl group may be substituted with —O—, —S— or —NH—.

A dichroic dye may be a dye that has an absorption maximum wavelength (λ _MAX ) in the range that is 300-700 nm. 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, tetrakis azo dyes and stilbene azo dyes. The polarizer layer 5 may contain two or more dichroic dyes (especially azo dyes) or three or more dichroic dyes (especially azo dyes).

For example, the azo dye may be a compound represented by the chemical formula B below.
A ¹ (-N=NA ² ) _p -N=NA ³ (B)
A ¹ and A ³ are each independently a phenyl group optionally having substituent(s), a naphthyl group optionally having substituent(s), or a monovalent heterocyclic ring optionally having substituent(s) represents a group.
A ² is an optionally substituted 1,4-phenylene group, an optionally substituted naphthalene-1,4-diyl group, or an optionally substituted divalent represents a heterocyclic group.
p represents an integer of 1 to 4; When p is 2 or more, the plurality of A ² may be the same as each other, or the plurality of A ² may be different from each other.

Solvents used as raw materials for the polarizer layer include 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; ethyl acetate, butyl acetate, ethylene glycol. ester solvents such as 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; pentane, hexane and heptane At least one selected from the group consisting of aliphatic hydrocarbon solvents; 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. may be a solvent of

The raw material for the polarizer layer may contain a polymerization initiator (such as a photopolymerization initiator). 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.

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

A “photo-alignment layer” described in WO 2020/122117 may be used as the alignment layer 4 and a “liquid crystal layer” described in the same document may be used as the polarizer layer 5 . A “photo-alignment film” described in WO 2020/179864 may be used as the alignment layer 4 , and a “polarizing layer” described therein may be used as the polarizer layer 5 .

(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 is 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. may be at least one polyvinyl alcohol. A method for forming the second protective layer 6 includes 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. good.

The second protective layer 6 may contain a cured product of a cationic polymerizable compound such as an epoxy compound, an oxetane compound and a vinyl compound. The second protective layer 6 may contain a cured product of a radically polymerizable compound.

(First adhesive layer 7 and second adhesive layer 9)
Each of the first adhesive layer 7 and the second adhesive layer 9 contains (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; ) acrylate compounds; epoxy (meth)acrylate compounds such as polyfunctional epoxy acrylate compounds and polyfunctional epoxy methacrylate compounds; carboxyl group-modified epoxy acrylate compounds, pocarboxyl group-modified epoxy methacrylate compounds, polyester acrylate compounds, polyester methacrylate compounds, epoxy groups may contain a polymer (cured product) of at least one polymerizable compound selected from the group consisting of an epoxy compound having an oxetanyl group, an oxetane compound having an oxetanyl group, and a vinyl compound. The polymerization method (curing method) of the polymerizable compound may be irradiation of light (such as ultraviolet rays) 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, and the retardation layer 8 is the uncured first adhesive layer 7. and the first adhesive layer 7 may be cured immediately after the retardation layer 8 is laminated.
An uncured second adhesive layer 9 containing a polymerizable compound and a solvent may be formed on the surface of the retardation layer 8 or the optical compensation layer 10, and the optical compensation layer 10 forms the uncured second adhesive layer 9. The second adhesive layer 9 may be adhered to the surface of the retardation layer 8 via the optical compensation layer 10 , and the second adhesive layer 9 may be cured immediately after the optical compensation layer 10 is adhered.
The composition of the first adhesive layer 7 may be the same as the composition of the second adhesive layer 9 . The composition of the first adhesive layer 7 may differ from the composition of the second adhesive layer 9 .

(Retardation Layer 8 and Optical Compensation Layer 10)
The optical compensation layer 10 may be rephrased as a retardation layer different from the retardation layer 8 . For example, each of the retardation layer 8 and the optical compensation layer 10 is at least one selected from the group consisting of a positive A plate such as a λ / 4 plate and a λ / 2 plate, and a positive C plate (photo-alignment material vertical alignment film) can be Each of the retardation layer 8 and the optical compensation layer 10 may be formed by applying the polymerizable liquid crystal compound to an alignment layer different from the alignment layer 4 . The formation method of the alignment layer for forming the retardation layer 8 and the optical compensation layer 10 may be the same as that for the alignment layer 4 for the polarizer layer 5 .

The invention is not necessarily limited to the embodiments described above. Various modifications of the present invention are possible without departing from the gist of the present invention, and these modifications are also included in the present invention.

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, and a second step of directly or indirectly laminating on the surface; a third step of directly or indirectly laminating another resin layer on the surface of the polarizer layer 5 via the first adhesive layer 7; After the three steps, a fourth step of heating the ends of the substrate layer 2 and the surface treatment layer 3 at the same time, and a fifth step of peeling off the substrate 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.
By the fourth step of simultaneously heating the ends of the base material layer 2 and the surface treatment layer 3, the 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 edge of the base material layer 2 with respect to the edge of the surface treatment layer 3 increases. On the other hand, the peel strength of the base material layer 2 to the surface treatment layer 3 does not change at the portions other than the ends of the base material layer 2 and the surface treatment layer 3 . Therefore, by the fourth step, the substrate laminate A having Ie higher than Ic is obtained as in the first embodiment described above. In other words, in the second embodiment, the optical layered body B is obtained in the same manner as in the first embodiment by the steps performed before the fifth step. Therefore, in the second embodiment, as in the first embodiment, the end piece E adhered to the end of the base material layer 2 is separated from the end of the optical layered body B by the fifth step of peeling off the base material layer 2 . It can be easily removed from the part.

A polarizer according to the present invention may be a circular polarizer or an elliptically polarizer with one or more retardation layers. The polarizing plate according to the present invention may be a linear polarizing plate having no retardation layer.

For example, the substrate layered product and the optical layered product according to one aspect of the present invention may be used for manufacturing a polarizing plate.

DESCRIPTION OF SYMBOLS 1... Protective layer for base materials, 2... Base material layer, 3... Surface treatment layer (first protective layer), 4... Orientation layer, 5... Polarizer layer, 6... Second protective layer, 7... First adhesive Layer, 8... Retardation layer (another resin layer), 9... Second adhesive layer, 10... Optical compensation layer (another retardation layer), 11... Third protective layer, A... Base material laminate, B ... optical layered body, C ... polarizing plate.

Claims (14)

A substrate laminate comprising a substrate layer and a surface-treated layer directly laminated on the surface of the substrate layer,
The substrate laminate includes a pair of ends facing each other in a direction substantially parallel to the surface of the substrate layer, and a central portion located between the pair of ends,
The peel strength of the base layer with respect to the surface treatment layer at least one of the ends is represented as Ie,
The peel strength of the base layer with respect to the surface treatment layer in the central portion is represented as Ic,
Ie is higher than Ic;
Base material laminate. The Ie is higher than the Ic and is 0.40 N/25 mm or more,
The Ic is lower than the Ie and 0.55 N/25 mm or less,
The substrate laminate according to claim 1. A substrate laminate according to claim 1 or 2, and a polarizer layer,
The polarizer layer is laminated directly or indirectly on the surface of the surface treatment layer included in the substrate laminate,
The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye,
Optical laminate. At least one end of the substrate laminate is located outside a region surrounded by the outer periphery of the polarizer layer in a direction substantially parallel to the surface of the surface treatment layer,
The optical laminate according to claim 3. comprising 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 claim 3 or 4. The other resin layer is a retardation layer,
The optical laminate according to claim 5. In a direction substantially parallel to the surface of the surface treatment layer, at least one end of the substrate laminate is positioned outside a region surrounded by the outer periphery of the adhesive layer,
The optical laminate according to claim 5 or 6. 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 of the substrate laminate is 0.1 mm or more and less than 55 mm. be,
The optical laminate according to claim 7. At least one end of the polarizer layer is located outside the area surrounded by the outer periphery of the adhesive layer in a direction substantially parallel to the surface of the surface treatment layer,
The optical layered body according to any one of claims 5 to 8. A method for producing the substrate laminate according to claim 1 or 2,
a step of directly laminating the surface treatment layer on the surface of the base material layer to obtain a laminate;
A step of winding the laminate to obtain a roll;
a step of heating at least one end face of a pair of facing end faces of the roll;
comprising
A method for producing a substrate laminate. A method for producing the substrate laminate according to claim 1 or 2,
a step of performing a corona treatment on at least one of a pair of opposing ends of the base material layer;
After the corona treatment, directly laminating the surface treatment layer on the surface of the base material layer;
comprising
A method for producing a substrate laminate. A step of peeling off the base layer from the optical laminate according to any one of claims 3 to 9,
A method for manufacturing a polarizing plate. A step of directly laminating the surface treatment layer on the surface of the base material layer;
a step of directly or indirectly laminating a polarizer layer on the surface of the surface treatment layer;
a step of directly or indirectly laminating another resin layer on the surface of the polarizer layer via an adhesive layer;
After the step of directly or indirectly laminating the other resin layer on the surface of the polarizer layer through the adhesive layer, the end portions of the base layer and the surface treatment layer are simultaneously attached. a step of heating;
After the step of simultaneously heating the ends of the base layer and the surface treatment layer, the step of peeling off the base layer;
with
By the step of simultaneously heating the ends of the base material layer and the surface treatment layer, the peel strength of the ends of the base layer with respect to the edges of the surface treatment layer is increased,
The polarizer layer contains a polymer of a polymerizable liquid crystal compound and a dichroic dye,
A method for manufacturing a polarizing plate. The other resin layer is a retardation layer,
14. The method for producing a polarizing plate according to claim 13.

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