WO2022201907A1

WO2022201907A1 - Polarizing plate with retardation layer and production method therefor, and image display device using said polarizing plate with retardation layer

Info

Publication number: WO2022201907A1
Application number: PCT/JP2022/004574
Authority: WO
Inventors: 大輔林; 亮菅野
Original assignee: 日東電工株式会社
Priority date: 2021-03-22
Filing date: 2022-02-07
Publication date: 2022-09-29
Also published as: TW202248691A; KR20230145479A; JP2022146118A; CN117242374A

Abstract

Provided is a polarizing plate that is provided with a retardation layer and that can be used to implement an image display device in which a reflection hue change is inhibited in a high temperature environment. The polarizing plate with a retardation layer according to an embodiment of the present invention has: a polarizing plate including a polarizer and a protective layer on at least one side of the polarizer; a first retardation layer disposed on the polarizing plate on a side opposite to the visible side thereof; and a second retardation layer attached, via an adhesive layer, to the first retardation layer on a side opposite to the polarizing plate. The first retardation layer is a retardation layer other than a C plate, and the second retardation layer is a C plate. In one embodiment, the adhesive layer is made of an actinic radiation curable adhesive. The curing shrinkage rate of the adhesive is at least 5%. In another embodiment, a layered product of the first retardation layer and the second retardation layer is subjected to an annealing treatment.

Description

Polarizing plate with retardation layer, method for producing the same, and image display device using the polarizing plate with retardation layer

The present invention relates to a polarizing plate with a retardation layer, a manufacturing method thereof, and an image display device using the polarizing plate with a retardation layer.

In recent years, image display devices represented by liquid crystal display devices and electroluminescence (EL) display devices (eg, organic EL display devices and inorganic EL display devices) have rapidly spread. Polarizing plates and retardation plates are typically used in image display devices. Practically, a polarizing plate with a retardation layer, in which a polarizing plate and a retardation plate are integrated, is widely used. There is also an increasing demand for thinner layered polarizing plates. As one approach to thinning the retardation layer-equipped polarizing plate, a retardation layer-equipped polarizing plate using a retardation layer in which a liquid crystal compound is fixed in an aligned state has been proposed. However, an image display device using such a retardation layer-attached polarizing plate has a problem that the reflection hue change is large in a high-temperature environment.

JP 2020-064274 A

The present invention was made to solve the above-mentioned conventional problems, and its main object is to provide a polarizing plate with a retardation layer that can realize an image display device in which the change in reflection hue is suppressed in a high-temperature environment. That's what it is.

A polarizing plate with a retardation layer according to an embodiment of the present invention includes a polarizing plate including a polarizer and a protective layer on at least one of the polarizer, and a first position disposed on the side opposite to the viewing side of the polarizing plate. It has a retardation layer, and a second retardation layer attached to the side of the first retardation layer opposite to the polarizing plate via an adhesive layer. The first retardation layer is a retardation layer other than the C plate, and the second retardation layer is the C plate. In one embodiment, the adhesive layer is composed of an active energy ray-curable adhesive, and the curing shrinkage of the adhesive is 5% or more. In another embodiment, the laminate of the first retardation layer and the second retardation layer is annealed.
In one embodiment, the first retardation layer exhibits refractive index characteristics of nx>ny≧nz, Re(550) is 100 nm to 200 nm, and Re(450)<Re(550). the second retardation layer exhibits a refractive index characteristic of nz>nx=ny. Here, Re(450) and Re(550) are the in-plane retardation measured with light having wavelengths of 450 nm and 550 nm at 23° C., respectively.
In one embodiment, the first retardation layer and the second retardation layer are alignment fixed layers of a liquid crystal compound.
According to another aspect of the present invention, there is provided a method for producing the retardation layer-attached polarizing plate. This manufacturing method comprises forming the first retardation layer on a first substrate, forming the second retardation layer on a second substrate, and forming the first retardation layer on the first substrate and The first retardation layer of the laminate of the first retardation layers, the second substrate, and the second retardation layer of the laminate of the second retardation layers are irradiated with an active energy ray. laminating via a curable adhesive to form an intermediate laminate.
In one embodiment, the curing shrinkage of the active energy ray-curable adhesive is 5% or more. In this case, the manufacturing method includes increasing Re(550) of the first retardation layer by 0.5 nm or more when forming the intermediate laminate.
In another embodiment, the manufacturing method further includes annealing the intermediate laminate. In this case, the manufacturing method includes increasing Re(550) of the first retardation layer by 0.5 nm or more by the annealing treatment. In one embodiment, the annealing treatment has a treatment temperature of 80° C. or higher and a treatment time of 1 minute or longer.
According to still another aspect of the present invention, an image display device is provided. This image display device includes the retardation layer-attached polarizing plate described above.

According to the embodiment of the present invention, it is possible to obtain a polarizing plate with a retardation layer that can realize an image display device in which change in reflection hue is suppressed in a high-temperature environment.

1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to one embodiment of the present invention; FIG. FIG. 2 is a flow chart including schematic cross-sectional views for explaining the manufacturing process of the polarizing plate with retardation layer according to the embodiment of the present invention.

Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

(Definition of terms and symbols)
Definitions of terms and symbols used herein are as follows.
(1) refractive index (nx, ny, nz)
"nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., slow axis direction), and "ny" is the in-plane direction orthogonal to the slow axis (i.e., fast axis direction) and "nz" is the refractive index in the thickness direction.
(2) In-plane retardation (Re)
“Re(λ)” is an in-plane retardation measured at 23° C. with light having a wavelength of λ nm. For example, "Re(550)" is the in-plane retardation measured with light having a wavelength of 550 nm at 23°C. Re(λ) is obtained by the formula: Re(λ)=(nx−ny)×d, where d (nm) is the thickness of the layer (film).
(3) Thickness direction retardation (Rth)
“Rth(λ)” is the retardation in the thickness direction measured at 23° C. with light having a wavelength of λ nm. For example, “Rth(550)” is the retardation in the thickness direction measured at 23° C. with light having a wavelength of 550 nm. Rth(λ) is determined by the formula: Rth(λ)=(nx−nz)×d, where d (nm) is the thickness of the layer (film).
(4) Nz Coefficient The Nz coefficient is obtained by Nz=Rth/Re.
(5) Angle When referring to an angle in this specification, the angle includes both clockwise and counterclockwise directions with respect to a reference direction. Thus, for example, "45°" means ±45°.

A. Overall Configuration of Retardation Layer-Equipped Polarizing Plate FIG. 1 is a schematic cross-sectional view of a retardation layer-attached polarizing plate according to one embodiment of the present invention. A polarizing plate 100 with a retardation layer in the illustrated example typically has a polarizing plate 10, a first retardation layer 21, and a second retardation layer 22 in this order from the viewing side. Polarizing plate 10 includes polarizer 11 and a protective layer disposed on at least one of polarizer 11 . In the illustrated example, protective layers (viewing-side protective layer 12 and inner protective layer 13) are arranged on both sides of the polarizer 11, but one of the viewing-side protective layer 12 or the inner protective layer 13 is omitted depending on the purpose. may be The first retardation layer 21 is typically attached to the opposite side of the polarizing plate 10 to the viewing side with the first pressure-sensitive adhesive layer 40 interposed therebetween. The second retardation layer 22 is attached to the side of the first retardation layer 21 opposite to the polarizing plate 10 with an adhesive layer 30 interposed therebetween.

In the embodiment of the present invention, the first retardation layer 21 is a retardation layer other than the C plate, and the second retardation layer 22 is the C plate. The first retardation layer 21 typically exhibits a refractive index characteristic of nx>ny≧nz. That is, the first retardation layer can be a positive A plate (nx>ny=nz) or a negative B plate (nx>ny>nz). Further, the first retardation layer preferably has Re(550) of 100 nm to 200 nm, and preferably satisfies the relationship Re(450)<Re(550). The second retardation layer 22 typically exhibits a refractive index characteristic of nz>nx=ny. That is, the second retardation layer can be a positive C-plate. If the first retardation layer and the second retardation layer have such a structure, it is possible to realize a polarizing plate with a retardation layer having excellent antireflection properties.

The first retardation layer and the second retardation layer are typically oriented and fixed layers of a liquid crystal compound (hereinafter sometimes simply referred to as liquid crystal oriented and fixed layers). By using a liquid crystal compound, the difference between nx and ny in the resulting retardation layer can be significantly increased compared to a non-liquid crystal material. The layer thickness can be significantly reduced. Also, the second retardation layer (positive C plate) can be formed with a very thin thickness. As a result, it is possible to further reduce the thickness of the retardation layer-attached polarizing plate. As used herein, the term "fixed alignment layer" refers to a layer in which a liquid crystal compound is aligned in a predetermined direction and the alignment state is fixed. In addition, the "alignment fixed layer" is a concept including an alignment cured layer obtained by curing a liquid crystal monomer. The first retardation layer is typically aligned in a state in which rod-shaped liquid crystal compounds are aligned in the slow axis direction of the retardation layer (homogeneous alignment); In the film, rod-like liquid crystal compounds are aligned perpendicular to the film surface (homeotropic alignment).

In the embodiment of the present invention, the adhesive layer 30 is composed of an active energy ray-curable adhesive. Cure shrinkage of the adhesive is typically 5% or more. Additionally/or alternatively, the laminate of the first retardation layer and the second retardation layer is typically annealed. With such a configuration, the first Re(550) of the laminate (substantially, the first retardation layer) of the retardation layer and the second retardation layer can be increased. As a result, the initial front reflection hue a value and b value of the image display device (before being placed in a high temperature environment) are shifted in advance in the direction of change in a high temperature environment in the L ^* a ^* b ^* color space chromaticity diagram. can be made Therefore, it is possible to reduce the reflection hue change Δa ^* b ^* in a high-temperature environment (for example, after an endurance test). Such an effect is remarkable when the retardation layer is a liquid crystal alignment fixed layer. That is, the liquid crystal alignment fixed layer is susceptible to dimensional shrinkage of the polarizing plate in a high-temperature environment, and tends to have a larger reflection hue change Δa ^* b ^* than the resin film retardation layer. Here, as described above, by previously shifting the initial front reflection hue a value and b value in the direction of change in the high temperature environment (by experiencing the influence of dimensional shrinkage in advance), polarized light in the high temperature environment The effect of dimensional shrinkage of the plate can be reduced, and as a result, the reflected hue change Δa ^* b ^* can be reduced.

Practically, a second adhesive layer is provided on the side opposite to the polarizing plate 10 of the second retardation layer 22 (that is, as the outermost layer on the side opposite to the viewing side), and the polarizing plate with a retardation layer is It can be attached to the image display panel. Furthermore, it is preferable that a release film (not shown) is temporarily attached to the surface of the second pressure-sensitive adhesive layer 50 until the polarizing plate with the retardation layer is used. Temporarily attaching the release film protects the second pressure-sensitive adhesive layer 50 and enables roll formation of the retardation layer-attached polarizing plate.

The total thickness of the retardation layer-attached polarizing plate is preferably 120 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. A lower limit for the total thickness can be, for example, 45 μm. A polarizing plate with a retardation layer having such a total thickness can have extremely excellent flexibility and bending durability. As a result, the retardation layer-attached polarizing plate can be particularly preferably applied to a curved image display device and/or a bendable or foldable image display device. The total thickness of the retardation layer-attached polarizing plate refers to the total thickness from the viewer side protective layer 12 (if present) to the second retardation layer 22 . That is, the total thickness of the retardation layer-attached polarizing plate does not include the thickness of the second adhesive layer 50 .

The retardation layer-attached polarizing plate may further include other optical functional layers. The type, properties, number, combination, arrangement position, etc. of the optical functional layers that can be provided in the polarizing plate with a retardation layer can be appropriately set according to the purpose. For example, the polarizing plate with a retardation layer may further have a conductive layer or an isotropic substrate with a conductive layer (neither is shown). A conductive layer or an isotropic substrate with a conductive layer is typically provided outside the second retardation layer 22 (on the side opposite to the polarizing plate 10). When a conductive layer or an isotropic substrate with a conductive layer is provided, the polarizing plate with a retardation layer is incorporated with a touch sensor between the image display panel and the polarizing plate, so-called inner touch panel type input display device can be applied. . Further, for example, the retardation layer-attached polarizing plate may further include other retardation layers. Other optical properties of the retardation layer (for example, refractive index properties, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, etc. can be appropriately set according to the purpose.

The polarizing plate with a retardation layer may be sheet-shaped or elongated. As used herein, the term "long shape" means an elongated shape whose length is sufficiently long relative to its width, for example, an elongated shape whose length is 10 times or more, preferably 20 times or more, its width. include. The elongated retardation layer-attached polarizing plate can be wound into a roll.

The components of the retardation layer-equipped polarizing plate will be described in more detail below.

B. Polarizing plate B-1. Polarizer Any appropriate polarizer can be employed as the polarizer 11 . For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

Specific examples of the polarizer composed of a single-layer resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene/vinyl acetate copolymer films. In addition, oriented polyene films such as those dyed with dichroic substances such as iodine and dichroic dyes and stretched, and dehydrated PVA and dehydrochlorinated polyvinyl chloride films. A polarizer obtained by dyeing a PVA-based film with iodine and uniaxially stretching the film is preferably used because of its excellent optical properties.

The dyeing with iodine is performed, for example, by immersing the PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial drawing is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment, or may be performed while dyeing. Moreover, you may dye after extending|stretching. If necessary, the PVA-based film is subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, not only can dirt and anti-blocking agents on the surface of the PVA-based film be washed away, but also the PVA-based film can be swollen to remove uneven dyeing. can be prevented.

Specific examples of the polarizer obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and the resin A polarizer obtained by using a laminate with a PVA-based resin layer formed by coating on a substrate can be mentioned. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer formed by coating on the resin base material is obtained, for example, by applying a PVA-based resin solution to the resin base material and drying the resin base material. forming a PVA-based resin layer thereon to obtain a laminate of a resin substrate and a PVA-based resin layer; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer; obtain. In this embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching. Furthermore, stretching may further include stretching the laminate in air at a high temperature (eg, 95° C. or higher) before stretching in an aqueous boric acid solution, if necessary. The obtained resin substrate/polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the resin substrate/polarizer laminate. Then, any appropriate protective layer may be laminated on the release surface according to the purpose. Details of the method for manufacturing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. These publications are incorporated herein by reference in their entirety.

The thickness of the polarizer is preferably 15 µm or less, more preferably 12 µm or less, still more preferably 10 µm or less, and particularly preferably 8 µm or less. On the other hand, the thickness of the polarizer is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more. If the thickness of the polarizer is within such a range, it is possible to satisfactorily suppress curling during heating, and obtain excellent durability in appearance during heating.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or higher, more preferably 99.0% or higher, still more preferably 99.9% or higher.

B-2. Protective Layers The viewing-side protective layer 12 and inner protective layer 13 are each composed of any suitable film that can be used as a protective layer for a polarizer. Specific examples of the material that is the main component of the film include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and polysulfone-based resins. , polystyrene-based, cyclic olefin-based (for example, polynorbornene-based), polyolefin-based, (meth)acrylic-based, and acetate-based transparent resins. Thermosetting resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone, or ultraviolet curable resins may also be used. In addition, for example, a glassy polymer such as a siloxane-based polymer can also be used. Further, polymer films described in JP-A-2001-343529 (WO01/37007) can also be used. Materials for this film include, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in a side chain. can be used, for example, a resin composition comprising an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extrudate of the resin composition.

The polarizing plate with a retardation layer is typically arranged on the viewer side of the image display device as described later, and the viewer side protective layer 12 is arranged on the viewer side. Therefore, the visible-side protective layer 12 may be subjected to surface treatment such as hard coat treatment, anti-reflection treatment, anti-sticking treatment, and anti-glare treatment, if necessary. Further/or, the visible-side protective layer 12 may optionally be treated to improve visibility when viewed through polarized sunglasses (typically, imparting an (elliptical) circular polarization function, super imparting a high retardation) may be applied. By performing such processing, excellent visibility can be achieved even when the display screen is viewed through polarized lenses such as polarized sunglasses. Therefore, the retardation layer-attached polarizing plate can also be suitably applied to an image display device that can be used outdoors. In addition, as a material constituting the visible side protective layer, cyclic olefin-based (for example, polynorbornene-based) and cellulose-based resin (for example, TAC) are preferably used.

The thickness of the visible-side protective layer 12 is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, still more preferably 10 μm to 30 μm. In addition, when the surface treatment is performed, the thickness of the viewer side protective layer is the thickness including the thickness of the surface treatment layer.

The inner protective layer 13 is preferably optically isotropic in one embodiment. As used herein, “optically isotropic” means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is −10 nm to +10 nm. Say. The thickness of the inner protective layer 13 is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, still more preferably 10 μm to 30 μm. Preferred materials for the inner protective layer include cyclic olefin-based (eg, polynorbornene-based), cellulose-based resins (eg, TAC), and acrylic-based resins.

C. Retardation layer C-1. First Retardation Layer The first retardation layer 21 can typically function as a λ/4 plate. The first retardation layer is typically provided to impart antireflection properties to the image display device. The first retardation layer typically exhibits refractive index characteristics of nx>ny≧nz as described above. The in-plane retardation Re(550) of the first retardation layer is preferably 100 nm to 200 nm, more preferably 110 nm to 170 nm, still more preferably 120 nm to 160 nm, as described above. Here, "ny=nz" includes not only the case where ny and nz are completely equal but also the case where they are substantially equal. Therefore, ny>nz or ny<nz may be satisfied within a range that does not impair the effects of the present invention.

The Nz coefficient of the retardation layer is preferably 0.9 to 1.5, more preferably 0.9 to 1.3. By satisfying such a relationship, it is possible to obtain an image display device having a very excellent reflective hue.

The first retardation layer preferably exhibits reverse dispersion wavelength characteristics in which the retardation value increases according to the wavelength of the measurement light. That is, the first retardation layer preferably satisfies the relationship Re(450)<Re(550) as described above. The first retardation layer preferably further satisfies the relationship Re(550)<Re(650). Re(450)/Re(550) of the first retardation layer is preferably 0.8 or more and less than 1, more preferably 0.8 or more and 0.95 or less. Re(650)/Re(550) of the first retardation layer is preferably 1.0 or more and less than 1.15, more preferably 1.03 to 1.1. With such a configuration, very excellent antireflection properties can be achieved.

The angle between the slow axis of the retardation layer and the absorption axis of the polarizer is preferably 40° to 50°, more preferably 42° to 48°, still more preferably about 45°. If the angle is within such a range, an image display device having extremely excellent antireflection properties can be obtained by using a λ/4 plate as the retardation layer as described above.

The first retardation layer can typically be a liquid crystal alignment fixed layer as described above. As described above, by using a liquid crystal compound, the difference between nx and ny in the resulting retardation layer can be significantly increased compared to a non-liquid crystal material. The thickness of the retardation layer 1 can be remarkably reduced. In the first retardation layer, typically, as described above, rod-like liquid crystal compounds are aligned in the slow axis direction of the retardation layer (homogeneous alignment).

Liquid crystal compounds include, for example, liquid crystal compounds whose liquid crystal phase is a nematic phase (nematic liquid crystal). As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. Either lyotropic or thermotropic mechanism may be used to develop the liquid crystallinity of the liquid crystal compound. The liquid crystal polymer and liquid crystal monomer may be used alone or in combination.

When the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a crosslinkable monomer. This is because the alignment state of the liquid crystal monomer can be fixed by polymerizing or cross-linking (that is, curing) the liquid crystal monomer. After aligning the liquid crystal monomers, for example, the alignment state can be fixed by polymerizing or cross-linking the liquid crystal monomers. Here, a polymer is formed by polymerization and a three-dimensional network structure is formed by cross-linking, but these are non-liquid crystalline. Therefore, the formed first retardation layer does not undergo a transition to a liquid crystal phase, a glass phase, or a crystal phase due to a change in temperature, which is peculiar to liquid crystalline compounds. As a result, the first retardation layer becomes a highly stable retardation layer that is not affected by temperature changes.

The temperature range in which the liquid crystal monomer exhibits liquid crystallinity differs depending on the type. Specifically, the temperature range is preferably 40°C to 120°C, more preferably 50°C to 100°C, and most preferably 60°C to 90°C.

Any appropriate liquid crystal monomer can be adopted as the liquid crystal monomer. For example, polymerizable mesogenic compounds described in JP-T-2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171, and GB2280445 can be used.

The thickness of the first retardation layer can typically be set to a thickness that allows it to function properly as a λ/4 plate. The thickness of the first retardation layer is preferably 0.5 μm to 7 μm, more preferably 1 μm to 5 μm. By using a liquid crystal compound, it is possible to realize an in-plane retardation equivalent to that of a resin film with a thickness much thinner than that of a resin film.

C-2. Second Retardation Layer As described above, the second retardation layer 22 may be a positive C-plate exhibiting a refractive index characteristic of nz>nx=ny. By using a positive C plate as the second retardation layer, it is possible to satisfactorily prevent reflection in oblique directions and widen the viewing angle of the antireflection function. In this case, the thickness direction retardation Rth (550) of the second retardation layer is preferably −50 nm to −300 nm, more preferably −70 nm to −250 nm, still more preferably −90 nm to −200 nm, particularly preferably -100 nm to -180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal but also the case where nx and ny are substantially equal. That is, the in-plane retardation Re(550) of the second retardation layer can be less than 10 nm.

The second retardation layer can be made of any suitable material. The second retardation layer preferably consists of a film containing a liquid crystal material fixed in homeotropic alignment. A liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the retardation layer include the liquid crystal compound and the method for forming the retardation layer described in [0020] to [0028] of JP-A-2002-333642. In this case, the thickness of the second retardation layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 8 μm, still more preferably 0.5 μm to 5 μm.

D. Adhesive Layer As described above, the adhesive layer 30 is composed of an active energy ray-curable adhesive. The curing shrinkage of the adhesive is typically 5% or more, preferably 7% or more, more preferably 10% or more, and still more preferably 14% or more, as described above. The upper limit of cure shrinkage of the adhesive may be, for example, 20%. With such a configuration, Re (550) of the laminate of the first retardation layer and the second retardation layer (substantially, the first retardation layer) can be increased, The front reflection hue a value and b value at the initial stage (before being placed in a high temperature environment) of the image display device can be shifted in advance in the direction of change in the L ^* a ^* b ^* color space chromaticity diagram under the high temperature environment. can. Therefore, it is possible to reduce the reflection hue change Δa ^* b ^* in a high-temperature environment (for example, after an endurance test). When annealing the laminate of the first retardation layer and the second retardation layer, even if the curing shrinkage rate of the adhesive is smaller than the above range (for example, 3%), the above You may get an effect like

Any appropriate active energy ray-curable adhesive can be used as the active energy ray-curable adhesive as long as the cure shrinkage rate can be within the above range. Examples of active energy ray-curable adhesives include ultraviolet-curable adhesives and electron beam-curable adhesives. From the viewpoint of the curing mechanism, active energy ray-curable adhesives include, for example, radical-curing, cationic-curing, anion-curing, and hybrids of radical-curing and cationic-curing. Typically, a radical curing ultraviolet curing adhesive may be used. This is because it is excellent in versatility and the characteristics (structure) can be easily adjusted.

An active energy ray-curable adhesive typically contains a monofunctional component, a multifunctional component (curing component), and a photopolymerization initiator. Each monofunctional component and multifunctional component is typically a radically polymerizable compound. Preferred monofunctional components include, for example, higher alkyl esters of (meth)acrylic acid and modified products thereof. Specific examples include isostearyl acrylate, lauryl acrylate, acryloylmorpholine, and unsaturated fatty acid hydroxyalkyl ester-modified ε-caprolactone. Preferred multifunctional components include monomers and/or oligomers having two or more functional groups such as (meth)acrylate groups and (meth)acrylamide groups. Specific examples include polyethylene glycol diacrylate, trimethylpropane triacrylate, and glycerin triacrylate. Specific examples of monofunctional or multifunctional components other than the above include tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecanedimethanol diacrylate, phenoxydiethylene glycol acrylate, and cyclic trimethylolpropane formal acrylate. , dioxane glycol diacrylate, EO-modified diglycerin tetraacrylate, γ-butyrolactone acrylate, N-methylpyrrolidone, hydroxyethylacrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, 9-vinylcarbazole. be done. In one embodiment, the monofunctional or multifunctional component has a ring structure. Specific examples include acryloylmorpholine, γ-butyrolactone acrylate, unsaturated fatty acid hydroxyalkyl ester-modified ε-caprolactone, N-methylpyrrolidone, and 9-vinylcarbazole. Each of the monofunctional component and the polyfunctional component may be used alone or in combination of two or more.

The active energy ray-curable adhesive may further contain a cationic polymerizable compound, if necessary. The cationically polymerizable compound may be monofunctional or polyfunctional. Examples of monofunctional cationic polymerizable compounds include p-tert-butylphenyl glycidyl ether and 3-ethyl-3-[(2-ethylhexyl)oxy]oxetane. Examples of polyfunctional cationic polymerizable compounds include 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane. A silane coupling agent may be used as the cationic polymerizable compound. Examples of silane coupling agents include 3-glycidoxypropyltrimethoxysilane.

The active energy ray-curable adhesive may further contain an acrylic oligomer as necessary. The molecular weight of the acrylic oligomer can be appropriately set depending on the purpose.

The active energy ray-curable adhesive may further contain a plasticizer (for example, an oligomer component), a cross-linking agent, a diluent, etc., depending on the purpose. By adjusting the types, combinations, and blending ratios of these components, as well as the above-mentioned monofunctional components, polyfunctional components, cationic polymerizable compounds, acrylic oligomers and photopolymerization initiators, an activity having a desired cure shrinkage rate can be obtained. An energy ray-curable adhesive can be obtained. In addition, you may use a commercial item for each said component.

The thickness of the active energy ray-curable adhesive after curing is preferably 0.1 μm to 3.0 μm.

Details of the active energy ray-curable adhesive are described, for example, in JP-A-2018-017996. The description of the publication is incorporated herein by reference.

E. Adhesive Layer Any appropriate adhesive can be used for the first adhesive layer 40 and the second adhesive layer 50 depending on the purpose, and thus detailed description thereof is omitted.

F. Method for Producing Polarizing Plate with Retardation Layer Embodiments of the present invention also include the method for producing the polarizing plate with retardation layer. This manufacturing method includes forming a first retardation layer on a first substrate, forming a second retardation layer on a second substrate, and forming the first substrate and the second retardation layer. The first retardation layer of the laminate of one retardation layer, the second substrate and the second retardation layer of the laminate of the second retardation layer are combined with an active energy ray-curable laminating via an adhesive to form an intermediate laminate. A representative example of the manufacturing method will be described below with reference to FIG.

First, as shown in FIG. 2( a ), the first retardation layer 21 is formed on the first base material 61 . The first substrate may include any suitable resin film. Specific examples include cellulose resin films such as triacetyl cellulose (TAC) films, polyester films such as polyethylene terephthalate (PET) films, and acrylic resin films. A TAC film is preferred. The first retardation layer is typically formed by subjecting the surface of the first substrate to alignment treatment, applying a coating liquid containing a liquid crystal compound to the surface, and applying the liquid crystal compound to the alignment treatment. It can be formed by aligning in a direction to which the polarizer is aligned and fixing the alignment state. Any appropriate orientation treatment can be adopted as the orientation treatment. Specific examples include mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment. Specific examples of mechanical orientation treatment include rubbing treatment and stretching treatment. Specific examples of physical orientation treatment include magnetic orientation treatment and electric field orientation treatment. Specific examples of chemical alignment treatment include oblique vapor deposition and photo-alignment treatment. Arbitrary appropriate conditions can be adopted as the processing conditions for various alignment treatments depending on the purpose. Alignment of the liquid crystal compound is performed by treatment at a temperature at which a liquid crystal phase is exhibited depending on the type of liquid crystal compound. By performing such a temperature treatment, the liquid crystal compound assumes a liquid crystal state, and the liquid crystal compound is aligned in accordance with the orientation treatment direction of the surface of the base material. In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is a polymerizable monomer or a crosslinkable monomer, the orientation state is fixed by subjecting the liquid crystal compound oriented as described above to a polymerization treatment or a crosslinking treatment. Thus, the first retardation layer 21 is formed on the first base material 61 .

On the other hand, as shown in FIG. 2(b), the second retardation layer 22 is formed on the second substrate 62. The second substrate includes any suitable resin film. Specific examples are as described above for the first substrate. The second substrate is preferably a PET film. The second retardation layer is formed, for example, as described above using the liquid crystal compound and formation method described in [0020] to [0028] of JP-A-2002-333642. Thus, the second retardation layer 22 is formed on the second base material 62 .

Next, as shown in FIG. 2(c), the first retardation layer 21 and the second retardation layer 22 in each laminate obtained above are bonded via an active energy ray-curable adhesive. to form an intermediate laminate. The active energy ray-curable adhesive is as described in section D above. More specifically, for example, an active energy ray-curable adhesive is applied to the surface of the second retardation layer, and the first retardation layer is brought into contact with the surface (typically, bonded) to form an intermediate An intermediate laminate is formed by forming a laminate precursor, heating it if necessary, and irradiating a predetermined integrated amount of active energy rays (eg, ultraviolet rays) to cure the adhesive. Here, the cure shrinkage rate of the active energy ray-curable adhesive is typically 5% or more as described above. If the curing shrinkage rate is within such a range, the Re(550) of the first retardation layer is preferably 0.5 nm or more, more preferably It can be increased by 1.0 nm or more, more preferably 1.5 nm or more, particularly preferably 2.5 nm or more, and most preferably 3.0 nm or more. As a result, the initial front reflection hue a value and b value of the image display device (before being placed in a high temperature environment) are shifted in advance in the direction of change in a high temperature environment in the L ^* a ^* b ^* color space chromaticity diagram. can be made Therefore, it is possible to reduce the reflection hue change Δa ^* b ^* in a high-temperature environment (for example, after an endurance test). However, when an annealing treatment, which will be described later, is performed, the effects of the embodiment of the present invention may be obtained even if the curing shrinkage rate is less than 5%.

Next, as shown in FIG. 2(d), the intermediate laminate is annealed. The annealing temperature is preferably 80° C. or higher, more preferably 90° C. or higher, still more preferably 95° C. or higher, and particularly preferably 100° C. or higher. The upper limit of the treatment temperature can be 120° C., for example. The treatment time can vary depending on the treatment temperature. The treatment time is preferably 1 minute or longer, more preferably 3 minutes or longer, still more preferably 7 minutes or longer, and particularly preferably 10 minutes or longer. The upper limit of treatment time can be, for example, 20 minutes. By performing the annealing treatment, Re (550) of the first retardation layer is preferably 0.5 nm or more, more preferably 1.0 nm or more, still more preferably 1.5 nm or more, particularly preferably 2.5 nm or more, Especially preferably, it can be increased by 3.0 nm or more. As a result, the initial front reflection hue a value and b value of the image display device (before being placed in a high temperature environment) are shifted in advance in the direction of change in a high temperature environment in the L ^* a ^* b ^* color space chromaticity diagram. can be made Therefore, it is possible to reduce the reflection hue change Δa ^* b ^* in a high-temperature environment (for example, after an endurance test). However, when the curing shrinkage rate of the active energy ray-curable adhesive is 5% or more as described above, the effects of the embodiment of the present invention may be obtained without performing the annealing treatment.

Preferably, an intermediate laminate is formed using an active energy ray-curable adhesive having a curing shrinkage of 5% or more, and the intermediate laminate can be subjected to an annealing treatment. As a result, Re(550) of the first retardation layer can be further increased.

Next, as shown in FIG. 2(e), the first base material 61 is peeled off from the intermediate laminate, and the first adhesive layer 40 is applied to the peeled surface (surface of the first retardation layer 21). Then, the polarizing plate is attached with the first pressure-sensitive adhesive layer 40 interposed therebetween. In addition, since the polarizing plate can be manufactured by any appropriate method, detailed description of the manufacturing method of the polarizing plate is omitted. Practically, as shown in FIG. 2(f), the second base material 62 is peeled off, and the second adhesive layer 50 is placed on the peeled surface (surface of the second retardation layer 22). . For example, the second pressure-sensitive adhesive layer is formed on a release film (not shown), the laminate of the second pressure-sensitive adhesive layer and the release film, the second pressure-sensitive adhesive layer is the surface of the second retardation layer are placed in contact with the Thus, a polarizing plate with a retardation layer can be produced. The release film is removed when the retardation layer-attached polarizing plate is used.

G. Image Display Device The polarizing plate with a retardation layer according to the above items A to F can be applied to an image display device. Accordingly, embodiments of the present invention include imaging devices using such retardation layer-attached polarizing plates. The image display device according to the embodiment of the present invention typically includes the retardation layer-attached polarizing plate described in the above items A to F on the viewing side thereof. The retardation layer-attached polarizing plate is laminated such that the retardation layer is on the image display panel side (the polarizing plate is on the viewing side). Typical image display devices include liquid crystal display devices, organic electroluminescence (EL) display devices, and inorganic EL display devices. In one embodiment, the image display device (eg, organic EL display device) has a curved shape (substantially a curved display screen) and/or is bendable or bendable.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. "Parts" and "%" in Examples and Comparative Examples are by weight unless otherwise specified.

(1) Curing Shrinkage The curing shrinkage of the ultraviolet curable adhesives used in Examples and Comparative Examples was measured using a resin curing shrinkage stress measuring device "EU201" manufactured by Sentech.
(2) Retardation increase value For the first retardation layer (before intermediate laminate production) and the intermediate laminate (after annealing if annealing) produced in Examples and Comparative Examples, the phase difference manufactured by Axometrics The in-plane retardation was measured using a measuring device (product name “Axo Scan”). The in-plane retardation was measured at a wavelength of 550 nm and at a temperature of 23°C. The difference between the in-plane retardation of the intermediate laminate and the in-plane retardation of the first retardation layer before the production of the intermediate laminate was defined as the "retardation increase value". The in-plane retardation of the intermediate laminate is substantially the in-plane retardation of the first retardation layer in the laminate.
(3) Δa ^* b ^*
The retardation layer-equipped polarizing plates obtained in Examples and Comparative Examples were attached to alkali-free glass plates to prepare test samples. The test sample was subjected to a durability test at 80°C for 500 hours. The test sample before and after the durability test is placed on a mirror plate, and the a value and b value are measured using a spectrophotometer/color difference meter "CM-26d" manufactured by Konica Minolta, Inc., and the difference is Δa ^*. b ^* .

[Production Examples 1 to 4: Preparation of UV-curable adhesives A to D]
Each component shown in Table 1 was blended in the ratio shown in Table 1 to prepare UV-curable adhesives A to D. Table 1 shows the cure shrinkage rates of the UV-curable adhesives A to D. In addition, the meaning of each term shown in Table 1 is as follows.
ACMO: Acryloylmorpholine manufactured by KJ Chemicals
Plaxel FA1DDM: unsaturated fatty acid hydroxyalkyl ester-modified ε-caprolactone manufactured by Daicel ISTA: isostearyl acrylate Light acrylate LA manufactured by Osaka Organic Chemical Industry Co., Ltd.: Lauryl acrylate Light acrylate 14EG-A manufactured by Kyoeisha Chemical Co., Ltd.: Kyoeisha Chemical Polyethylene glycol diacrylate light acrylate TMP-A manufactured by Kyoeisha Chemical Co., Ltd. Aronix M-930: glycerin triacrylate manufactured by Toagosei KBM-403: 3-glycidoxy manufactured by Shin-Etsu Chemical Co., Ltd. Propyltrimethoxysilane EX-146: p-tert-butylphenyl glycidyl ether OXT-212 manufactured by Nagase ChemteX Corporation: 3-ethyl-3-[(2-ethylhexyl)oxy]oxetane OXT-221 manufactured by Toagosei Co., Ltd.: Toagosei Co., Ltd. 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane ARUFON UP-1190: Toagosei Co., Ltd. ARUFON UG-4010: Toagosei Co., Ltd. Omnirad 819: IGMresins CPI-110P manufactured by San-Apro Co., Ltd.

[Example 1]
1. Production of Polarizer As a thermoplastic resin substrate, a long amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a water absorption of 0.75% and a Tg of about 75° C. was used. Corona treatment was applied to one side of the resin substrate.
Polyvinyl alcohol (degree of polymerization: 4,200, degree of saponification: 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOSEFIMER Z410") mixed at 9:1: 100 weight of PVA-based resin 13 parts by weight of potassium iodide was added to parts by weight, and dissolved in water to prepare an aqueous PVA solution (coating solution).
The above PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60° C. to form a PVA-based resin layer having a thickness of 13 μm, thereby producing a laminate.
The obtained laminate was uniaxially stretched 2.4 times at the free end in the machine direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 130° C. (in-air auxiliary stretching treatment).
Next, the laminate was immersed in an insolubilizing bath (an aqueous boric acid solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (insolubilizing treatment).
Next, the finally obtained polarizing film is placed in a dyeing bath (iodine aqueous solution obtained by blending iodine and potassium iodide at a weight ratio of 1:7 with respect to 100 parts by weight of water) at a liquid temperature of 30 ° C. It was immersed for 60 seconds while adjusting the concentration so that the single transmittance (Ts) was a desired value (dyeing treatment).
Next, it was immersed for 30 seconds in a cross-linking bath at a liquid temperature of 40°C (an aqueous solution of boric acid obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water). (crosslinking treatment).
After that, while immersing the laminate in an aqueous solution of boric acid (boric acid concentration: 4.0% by weight, potassium iodide: 5.0% by weight) at a liquid temperature of 70°C, the laminate is moved between rolls with different peripheral speeds in the longitudinal direction (longitudinal direction). ) was uniaxially stretched so that the total draw ratio was 5.5 times (underwater stretching treatment).
After that, the laminate was immersed in a washing bath (aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (washing treatment).
After that, while drying in an oven kept at 90° C., it was brought into contact with a heating roll made of SUS whose surface temperature was kept at 75° C. for about 2 seconds (drying shrinkage treatment). The shrinkage ratio in the width direction of the laminate due to the drying shrinkage treatment was 5.2%.
Thus, a polarizer having a thickness of 5 μm was formed on the resin substrate.

2. Preparation of Polarizing Plate An HC-COP film was attached to the surface of the polarizer of the resin substrate/polarizer laminate obtained above via an ultraviolet curable adhesive. Specifically, the curable adhesive was applied so as to have a thickness of 1.0 μm, and was bonded using a roll machine. After that, UV light was applied from the HC-TAC film side to cure the adhesive. The HC-COP film is a film in which a hard coat (HC) layer (2 μm thick) is formed on a cyclic olefin resin (COP) film (25 μm thick), and the COP film is placed on the polarizer side. pasted together. Next, the resin substrate was peeled off, and a TAC film having an Re(550) of about 0 nm to 2 nm was attached to the peeled surface in the same manner as described above. Thus, a polarizing plate was obtained.

3. Preparation of Liquid Crystal Alignment Fixed Layer Constituting Retardation Layer 3-1. First retardation layer 55 parts of the compound represented by the formula (I), 25 parts of the compound represented by the formula (II), 20 parts of the compound represented by the formula (III), and 400 parts of cyclopentanone (CPN) After adding to, heat to 60 ° C., stir to dissolve, after confirming dissolution, return to room temperature, 3 parts of Irgacure 907 (manufactured by BASF Japan Co., Ltd.), Megafac F-554 (manufactured by DIC Corporation ) and 0.1 part of p-methoxyphenol (MEHQ) were added and further stirred to obtain a solution. The solution was clear and homogeneous. The resulting solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. On the other hand, a polyimide solution for alignment film was applied to a TAC substrate by spin coating, dried at 100° C. for 10 minutes, and then baked at 200° C. for 60 minutes to obtain a coating film. The resulting coating film was rubbed to form an alignment film. The rubbing treatment was performed using a commercially available rubbing device. The polymerizable composition obtained above was applied to the surface of the alignment film by spin coating, and dried at 100° C. for 2 minutes. After cooling the obtained coating film to room temperature, it was irradiated with ultraviolet rays for 30 seconds at an intensity of 30 mW/cm ² using a high-pressure mercury lamp to obtain a liquid crystal alignment fixed layer (thickness 4 μm). The in-plane retardation Re(550) of the liquid crystal alignment fixed layer was 130 nm. In addition, the Re(450)/Re(550) of the liquid crystal alignment fixed layer was 0.851, showing reverse dispersion wavelength characteristics.

3-2. Second retardation layer Side chain type represented by the following chemical formula (1) (numbers 65 and 35 in the formula indicate mol% of the monomer unit, and are conveniently represented by block polymer body: weight average molecular weight 5000) 20 parts by weight of a liquid crystal polymer, 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name Paliocolor LC242) and 5 parts by weight of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals: trade name Irgacure 907) were added to cyclopenta A liquid crystal coating liquid was prepared by dissolving in 200 parts by weight of non. Then, the coating solution was applied to the vertically aligned PET substrate using a bar coater, and dried by heating at 80° C. for 4 minutes to align the liquid crystal. By irradiating the liquid crystal layer with ultraviolet rays and curing the liquid crystal layer, a second retardation layer (thickness: 3 μm) exhibiting refractive index characteristics of nz>nx=ny was formed on the substrate.

4. Production of polarizing plate with retardation layer 3-1. and 3-2. The first retardation layer and the second retardation layer in each of the laminates obtained in 1. were bonded together via a UV adhesive A (having a thickness of 1 μm after curing) to form an intermediate laminate. This intermediate laminate was annealed at 100° C. for 10 minutes. The TAC substrate was peeled off from the annealed intermediate laminate, an acrylic pressure-sensitive adhesive (thickness: 5 μm) was placed on the surface of the first retardation layer, and a polarizing plate was bonded via the acrylic pressure-sensitive adhesive. At this time, the polarizing plate was attached so that the TAC film was on the side of the first retardation layer. Next, the PET substrate was peeled off, and a laminate of an acrylic pressure-sensitive adhesive (thickness: 26 μm)/release film was placed on the surface of the second retardation layer. Thus, a polarizing plate with a retardation layer was produced. The obtained polarizing plate with a retardation layer was subjected to the evaluation of (3) above. Table 2 shows the results.

[Examples 2 to 13 and Comparative Examples 1 to 3]
A polarizing plate with a retardation layer was obtained in the same manner as in Example 1 except that the UV adhesive shown in Table 2 was used and the intermediate laminate was annealed under the conditions shown in Table 2. The obtained polarizing plate with a retardation layer was subjected to the same evaluation as in Example 1. Table 2 shows the results. "None" in the column of annealing treatment in Table 2 indicates that no annealing treatment was performed.

[evaluation]
As is clear from Table 2, the retardation layer-attached polarizing plates of the examples of the present invention have smaller Δa ^* b ^* than the comparative examples. That is, it can be seen that the retardation layer-attached polarizing plate of the example of the present invention can realize an image display device in which the reflection hue change is suppressed in a high-temperature environment.

The polarizing plate with a retardation layer of the present invention is suitably used as an antireflection circularly polarizing plate for an image display device.

REFERENCE SIGNS LIST 10 polarizing plate 11 polarizer 12 protective layer 13 protective layer 21 first retardation layer 22 second retardation layer 30 adhesive layer 40 first adhesive layer 50 second adhesive layer 100 polarized light with retardation layer board

Claims

A polarizing plate comprising a polarizer and a protective layer on at least one of the polarizer, a first retardation layer disposed on the side opposite to the viewing side of the polarizing plate, and the polarized light of the first retardation layer and a second retardation layer bonded via an adhesive layer on the opposite side of the plate,
The first retardation layer is a retardation layer other than a C plate, the second retardation layer is a C plate,
The adhesive layer is composed of an active energy ray-curable adhesive, and the curing shrinkage of the adhesive is 5% or more.
A polarizing plate with a retardation layer.
A polarizing plate comprising a polarizer and a protective layer on at least one of the polarizer, a first retardation layer disposed on the side opposite to the viewing side of the polarizing plate, and the polarized light of the first retardation layer and a second retardation layer bonded via an adhesive layer on the opposite side of the plate,
The first retardation layer is a retardation layer other than a C plate, the second retardation layer is a C plate,
The laminate of the first retardation layer and the second retardation layer is annealed.
A polarizing plate with a retardation layer.
The first retardation layer exhibits refractive index characteristics of nx>ny≧nz, Re(550) is 100 nm to 200 nm, and satisfies the relationship Re(450)<Re(550),
wherein the second retardation layer exhibits a refractive index characteristic of nz>nx=ny;
The polarizing plate with a retardation layer according to claim 1 or 2:
Here, Re(450) and Re(550) are the in-plane retardation measured with light having wavelengths of 450 nm and 550 nm at 23° C., respectively.
The polarizing plate with a retardation layer according to claim 3, wherein the first retardation layer and the second retardation layer are alignment fixed layers of a liquid crystal compound.
A method for producing a polarizing plate with a retardation layer according to claim 1,
forming the first retardation layer on a first substrate;
Forming the second retardation layer on a second substrate, and forming the first retardation layer and the second substrate in a laminate of the first substrate and the first retardation layer Bonding the material and the second retardation layer of the laminate of the second retardation layer via an active energy ray-curable adhesive to form an intermediate laminate;
including
The curing shrinkage of the active energy ray-curable adhesive is 5% or more,
Production method.
The manufacturing method according to claim 5, comprising increasing Re(550) of the first retardation layer by 0.5 nm or more when forming the intermediate laminate.
A method for producing a polarizing plate with a retardation layer according to claim 2,
forming the first retardation layer on a first substrate;
forming the second retardation layer on a second substrate;
The first retardation layer of the laminate of the first substrate and the first retardation layer, the second retardation of the laminate of the second substrate and the second retardation layer laminating the layers together via an active energy ray-curable adhesive to form an intermediate laminate, and annealing the intermediate laminate;
A manufacturing method, including:
The manufacturing method according to claim 7, wherein the annealing treatment has a treatment temperature of 80°C or higher and a treatment time of 1 minute or longer.
The manufacturing method according to claim 7 or 8, comprising increasing Re(550) of the first retardation layer by 0.5 nm or more by the annealing treatment.
An image display device comprising the retardation layer-attached polarizing plate according to any one of claims 1 to 4.