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

Abstract

To provide a polarizing plate with a retardation layer which can realize an image display device in which reflection hue change under a high temperature environment is suppressed.SOLUTION: A polarizing plate with a retardation layer according to an embodiment of the present invention comprises: a polarizing plate which includes polarizers and a protective layer in at least one of the polarizers; a first retardation layer which is arranged on the side opposite to the viewing side of the polarizing plate; and a second retardation layer which is pasted to the side opposite to the polarizing plate of the first retardation layer via an adhesive layer. The first retardation layer is the retardation layer other than a C plate and the second retardation layer is the C plate. In one embodiment, the adhesive layer consists of the activation energy ray curable adhesive, and the cure shrinkage of the adhesive is 5% or greater. In another embodiment, the laminated body of the first retardation layer and the second retardation layer is subjected to the annealing treatment.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a polarizing plate with a retardation layer, a method for manufacturing the same, and an image display device using the polarizing plate with a retardation layer.

Background Art

[0002] In recent years, image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (for example, organic EL display devices and inorganic EL display devices) have been rapidly spreading. Typically, a polarizing plate and a retardation plate are 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. Recently, as the demand for thinning of image display devices has been increasing, the demand for thinning of the polarizing plate with a retardation layer has also been increasing. As one approach to thinning the polarizing plate with a retardation layer, a polarizing plate with a retardation layer 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 polarizing plate with a retardation layer has a problem that the change in reflected color phase in a high-temperature environment is large.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention has been made to solve the above 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 reflected color phase in a high-temperature environment is suppressed.

Means for Solving the Problems

[0005] The retardation film - attached polarizing plate according to an embodiment of the present invention includes a polarizing plate including a polarizer and at least one protective layer on at least one of the polarizers, a first retardation film disposed on the side opposite to the viewing side of the polarizing plate, and a second retardation film bonded to the side opposite to the polarizing plate of the first retardation film via an adhesive layer. The first retardation film is a retardation film other than a C - plate, and the second retardation film is a C - plate. In one embodiment, the adhesive layer is composed of an active energy ray - curable adhesive, and the curing shrinkage rate of the adhesive is 5% or more. In another embodiment, the laminate of the first retardation film and the second retardation film is annealed. In one embodiment, the first retardation film exhibits a refractive index characteristic of nx>ny≧nz, Re(550) is 100 nm to 200 nm, and satisfies the relationship of Re(450)<Re(550); the second retardation film exhibits a refractive index characteristic of nz>nx = ny. Here, Re(450) and Re(550) are the in - plane retardations measured with light of wavelengths 450 nm and 550 nm at 23°C, respectively. In one embodiment, the first retardation film and the second retardation film are alignment - solidified layers of a liquid crystal compound. According to another aspect of the present invention, a method for manufacturing the above - mentioned retardation film - attached polarizing plate is provided. This manufacturing method includes forming the first retardation film on a first substrate, forming the second retardation film on a second substrate, and bonding the first retardation film of the laminate of the first substrate and the first retardation film and the second retardation film of the laminate of the second substrate and the second retardation film via an active energy ray - curable adhesive to form an intermediate laminate. In one embodiment, the curing shrinkage rate 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 film 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 treatment temperature of the annealing treatment is 80°C or higher, and the treatment time is 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 polarizing plate with a retardation layer described above.

Effects of the Invention

[0006] According to an 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 reflection color phase change in a high-temperature environment is suppressed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

[0009] (Definitions of Terms and Symbols) The definitions of the terms and symbols in this specification 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., the slow axis direction), “ny” is the refractive index in the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and “nz” is the refractive index in the thickness direction. (2) In-Plane Retardation (Re) "Re(λ)" is the in-plane retardation measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured with light of wavelength 550 nm at 23°C. Re(λ) can be obtained by the formula: Re(λ) = (nx - ny) × d, where d (nm) is the thickness of the layer (film). (3) Retardation in the thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured with light of wavelength λ nm at 23°C. For example, "Rth(550)" is the retardation in the thickness direction measured with light of wavelength 550 nm at 23°C. Rth(λ) can be obtained 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 the reference direction. Therefore, for example, "45°" means ±45°.

[0010] A. Overall configuration of the polarizing plate with a retardation layer FIG. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to one embodiment of the present invention. The polarizing plate with a retardation layer 100 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. The polarizing plate 10 includes a polarizer 11 and a protective layer disposed on at least one of the polarizers 11. In the illustrated example, protective layers (viewing-side protective layer 12 and inner protective layer 13) are disposed on both sides of the polarizer 11, but one of the viewing-side protective layer 12 or the inner protective layer 13 may be omitted depending on the purpose or the like. The first retardation layer 21 is typically bonded to the side of the polarizing plate 10 opposite to the viewing side via a first adhesive layer 40. The second retardation layer 22 is bonded to the side of the first retardation layer 21 opposite to the polarizing plate 10 via an adhesive layer 30.

[0011] In an embodiment of the present invention, the first retardation layer 21 is a retardation layer other than a C-plate, and the second retardation layer 22 is a C-plate. The first retardation layer 21 typically exhibits refractive index characteristics 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 Re(550) of the first retardation layer is preferably 100 nm to 200 nm, and preferably satisfies the relationship of Re(450) < Re(550). The second retardation layer 22 typically exhibits refractive index characteristics 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 configuration, a polarizing plate with a retardation layer having excellent antireflection characteristics can be realized.

[0012] The first retardation layer and the second retardation layer are typically an alignment and curing layer of a liquid crystal compound (hereinafter, may be simply referred to as a liquid crystal alignment and curing layer). By using a liquid crystal compound, the difference between nx and ny of the obtained retardation layer can be made significantly larger than that of a non-liquid crystal material, so that the thickness of the first retardation layer for obtaining a desired in-plane retardation can be significantly reduced. Also, the second retardation layer (positive C-plate) can be formed with a very thin thickness. As a result, further thinning of the polarizing plate with a retardation layer can be realized. In this specification, the "alignment and curing layer" refers to a layer in which a liquid crystal compound is aligned in a predetermined direction within the layer and the alignment state is fixed. Note that the "alignment and curing layer" is a concept including an alignment and curing layer obtained by curing a liquid crystal monomer. The first retardation layer typically has rod-shaped liquid crystal compounds aligned in the direction of the slow axis of the retardation layer (homogeneous alignment); the second retardation layer typically has rod-shaped liquid crystal compounds aligned perpendicular to the film surface (homeotropic alignment).

[0013] In an embodiment of the present invention, the adhesive layer 30 is composed of an active energy ray-curable adhesive. The curing shrinkage rate of the adhesive is typically 5% or more. Further / alternatively, the laminate of the first retardation layer and the second retardation layer is typically annealed. With such a configuration, compared with the case where the curing shrinkage rate of the adhesive is small and / or the laminate of the first retardation layer and the second retardation layer is not annealed, the Re(550) of the laminate of the first retardation layer and the second retardation layer (substantially, the first retardation layer) can be increased. As a result, the initial (before being placed in a high-temperature environment) front reflection hue a-value and b-value of the image display device can be shifted in advance in the direction of change in the high-temperature environment in the L * a * b * chromaticity diagram of the color space. Therefore, the change in the reflection hue Δa * b * under a high-temperature environment (for example, after a durability test) can be reduced. Such an effect is remarkable when the retardation layer is a liquid crystal alignment curing layer. That is, the liquid crystal alignment curing layer is easily affected by the dimensional shrinkage of the polarizing plate under a high-temperature environment, and the change in the reflection hue Δa * b * tends to be larger than that of the retardation layer of the resin film. Here, as described above, by shifting the initial front reflection hue a-value and b-value in advance in the direction of change in the high-temperature environment (by experiencing the influence of dimensional shrinkage in advance), the influence of the dimensional shrinkage of the polarizing plate under a high-temperature environment can be reduced, and as a result, the change in the reflection hue Δa * b * can be reduced.

[0014] Practically, a second adhesive layer is provided on the side opposite to the polarizing plate 10 of the second retardation layer 22 (i.e., as the outermost layer on the side opposite to the viewing side), and the polarizing plate with a retardation layer can be attached to the image display panel. Further, it is preferable that a release film (not shown) is temporarily attached to the surface of the second adhesive layer 50 until the polarizing plate with a retardation layer is put into use. By temporarily attaching the release film, the second adhesive layer 50 is protected and the roll formation of the polarizing plate with a retardation layer becomes possible.

[0015] The total thickness of the polarizing plate with a retardation layer is preferably 120 μm or less, more preferably 100 μm or less, and still more preferably 80 μm or less. The lower limit of the total thickness can be, for example, 45 μm. The polarizing plate with a retardation layer having such a total thickness can have extremely excellent flexibility and bending durability. As a result, the polarizing plate with a retardation layer can be particularly preferably applied to a curved image display device and / or an image display device that can be bent or folded. Note that the total thickness of the polarizing plate with a retardation layer refers to the total thickness from the viewing-side protective layer 12 (if present) to the second retardation layer 22. That is, the total thickness of the polarizing plate with a retardation layer does not include the thickness of the second adhesive layer 50.

[0016] The polarizing plate with a retardation layer may further include other optical functional layers. The type, characteristics, number, combination, arrangement position, etc. of the optical functional layers that can be provided on 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 (both not shown). The conductive layer or the isotropic substrate with a conductive layer is typically provided on the outer side (the side opposite to the polarizing plate 10) of the second retardation layer 22. When the conductive layer or the isotropic substrate with a conductive layer is provided, the polarizing plate with a retardation layer can be applied to a so-called inner touch panel type input display device in which a touch sensor is incorporated between the image display panel and the polarizing plate. Also, for example, the polarizing plate with a retardation layer may further include other retardation layers. The optical characteristics (e.g., refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, etc. of the other retardation layers can be appropriately set according to the purpose.

[0017] The retardation film - attached polarizing plate may be in a sheet form or in a long - strip form. In this specification, the "long - strip form" means an elongated shape where the length is sufficiently long compared to the width. For example, it includes an elongated shape where the length is 10 times or more, preferably 20 times or more, the width. The long - strip retardation film - attached polarizing plate can be wound into a roll.

[0018] Hereinafter, the components of the retardation film - attached polarizing plate will be described in more detail.

[0019] B. Polarizing plate B - 1. Polarizer As the polarizer 11, any appropriate polarizer can be adopted. For example, the resin film forming the polarizer may be a single - layer resin film or a laminate of two or more layers.

[0020] Specific examples of polarizers composed of a single - layer resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) - based films, partially formalized PVA - based films, and ethylene - vinyl acetate copolymer - based partially saponified films, which are subjected to dyeing treatment with dichroic substances such as iodine and dichroic dyes and stretching treatment, and polyene - based oriented films such as dehydrated products of PVA and dehydrochlorinated products of polyvinyl chloride. Preferably, a polarizer obtained by dyeing a PVA - based film with iodine and uniaxially stretching it is used because of its excellent optical properties.

[0021] The above - mentioned dyeing with iodine is performed, for example, by immersing a PVA - based film in an iodine aqueous solution. The stretching ratio of the above - mentioned uniaxial stretching is preferably 3 to 7 times. The stretching may be performed after the dyeing treatment, during the dyeing, or after the stretching and then the dyeing. If necessary, the PVA - based film is subjected to swelling treatment, cross - linking treatment, washing treatment, drying treatment, etc. For example, by immersing the PVA - based film in water and washing it before dyeing, not only can the dirt and blocking preventer on the surface of the PVA - based film be washed away, but also the PVA - based film can be swollen to prevent uneven dyeing.

[0022] Specific examples of the polarizer obtained using the 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 polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate. The polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced, for example, by coating a PVA-based resin solution on the resin substrate and drying it to form a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer a polarizer. In the present embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Further, stretching may further include, if necessary, air stretching the laminate at a high temperature (for example, 95° C. or higher) before stretching in the aqueous boric acid solution. The obtained laminate of the resin substrate / polarizer 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 laminate of the resin substrate / polarizer, and an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface and used. Details of such a method for manufacturing a polarizer are described, for example, in JP-A-2012-73580 and Japanese Patent No. 6470455. The entire descriptions of these publications are incorporated herein by reference.

[0023] 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 still more preferably 3 μm or more. If the thickness of the polarizer is in such a range, curling during heating can be well suppressed, and good appearance durability during heating can be obtained.

[0024] The polarizer preferably exhibits absorption dichroism at any wavelength in the range 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 more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more.

[0025] B-2. Protective layer The visible-side protective layer 12 and the inner protective layer 13 are each composed of any suitable film that can be used as a protective layer for the 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, polysulfone-based, polystyrene-based, cyclic olefin-based (e.g., polynorbornene-based), polyolefin-based, (meth)acrylic-based, acetate-based, and other transparent resins. Also included are thermosetting resins or ultraviolet-curable resins such as (meth)acrylic-based, urethane-based, (meth)acrylic urethane-based, epoxy-based, and silicone-based resins. In addition, for example, glassy polymers such as siloxane-based polymers are also included. Further, the polymer film described in JP-A-2001-343529 (WO01 / 37007) can also be used. As the material of this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used. Examples include a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extruded product of the above resin composition.

[0026] The retardation layer - attached polarizing plate is typically disposed on the viewing side of an image display device as described later, and the viewing - side protective layer 12 is disposed on its viewing side. Therefore, the viewing - side protective layer 12 may be subjected to surface treatments such as hard - coating treatment, antireflection treatment, anti - sticking treatment, antiglare treatment, etc., as required. Further / alternatively, the viewing - side protective layer 12 may be subjected to a treatment (typically, imparting an (elliptical) polarization function, imparting an ultra - high retardation) to improve the visibility when viewing through polarized sunglasses, as required. By performing such a treatment, excellent visibility can be realized even when viewing a display screen through a polarizing lens such as polarized sunglasses. Therefore, the retardation layer - attached polarizing plate can be suitably applied to an image display device that can be used outdoors. Note that, as materials constituting the viewing - side protective layer, preferably, cyclic olefin - based (e.g., polynorbornene - based), cellulose - based resins (e.g., TAC) can be mentioned.

[0027] The thickness of the viewing - side protective layer 12 is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 10 μm to 30 μm. When a surface treatment is performed, the thickness of the viewing - side protective layer is the thickness including the thickness of the surface treatment layer.

[0028] In one embodiment, the inner protective layer 13 is preferably optically isotropic. In this specification, "optically isotropic" means that the in - plane retardation Re(550) is 0 nm to 10 nm and the retardation in the thickness direction Rth(550) is - 10 nm to + 10 nm. The thickness of the inner protective layer 13 is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 10 μm to 30 μm. As materials constituting the inner protective layer, preferably, cyclic olefin - based (e.g., polynorbornene - based), cellulose - based resins (e.g., TAC), acrylic - based resins can be mentioned.

[0029] 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 characteristics to an 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 as described above, more preferably 110 nm to 170 nm, and even more preferably 120 nm to 160 nm. Here, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, within a range that does not impair the effects of the present invention, ny > nz or ny < nz may occur.

[0030] 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, an image display device having a very excellent reflected hue can be obtained.

[0031] The first retardation layer preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. That is, the first retardation layer preferably satisfies the relationship of Re(450) < Re(550) as described above. The first retardation layer preferably further satisfies the relationship of 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 characteristics can be realized.

[0032] The angle formed by the slow axis of the retardation layer and the absorption axis of the polarizer is preferably 40° to 50°, more preferably 42° to 48°, and even more preferably about 45°. If the angle is within such a range, by using the retardation layer as a λ / 4 plate as described above, an image display device having very excellent antireflection characteristics can be obtained.

[0033] The first retardation layer can typically be a liquid crystal alignment solidification layer as described above. As described above, by using a liquid crystal compound, the difference between nx and ny of the obtained retardation layer can be made significantly larger than that of a non-liquid crystal material, so that the thickness of the first retardation layer for obtaining a desired in-plane retardation can be made significantly smaller. The first retardation layer is typically, as described above, oriented with rod-shaped liquid crystal compounds aligned in the direction of the slow axis of the retardation layer (homogeneous alignment).

[0034] Examples of the liquid crystal compound include a liquid crystal compound having a nematic liquid crystal phase (nematic liquid crystal). As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The mechanism for expressing the liquid crystallinity of the liquid crystal compound may be either lyotropic or thermotropic. The liquid crystal polymer and the liquid crystal monomer may be used alone or in combination.

[0035] 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 crosslinking (i.e., curing) the liquid crystal monomer. After the liquid crystal monomer is aligned, for example, if the liquid crystal monomers are polymerized or crosslinked with each other, the alignment state can be fixed thereby. Here, a polymer is formed by polymerization and a three-dimensional network structure is formed by crosslinking, but these are non-liquid crystalline. Therefore, in the formed first retardation layer, for example, a transition from a liquid crystal phase, a glass phase, or a crystal phase due to a temperature change peculiar to the liquid crystalline compound does not occur. As a result, the first retardation layer becomes an extremely stable retardation layer that is not affected by temperature changes.

[0036] The temperature range in which the liquid crystal monomer exhibits liquid crystallinity varies depending on its 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.

[0037] As the liquid crystal monomer, any suitable liquid crystal monomer can be adopted. For example, polymerizable mesogenic compounds described in JP-T-2002-533742 (WO00 / 37585), EP358208 (US5211877), EP66137 (US4388453), WO93 / 22397, EP0261712, DE19504224, DE4408171, GB2280445, etc. can be used.

[0038] The thickness of the first retardation layer can typically be set to a thickness that can function appropriately 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, an in-plane retardation equivalent to that of a resin film can be achieved at a thickness significantly thinner than the resin film.

[0039] C-2. Second retardation layer As described above, the second retardation layer 22 can be a positive C-plate having a refractive index characteristic showing the relationship of nz > nx = ny. By using a positive C-plate as the second retardation layer, reflection in the oblique direction can be well prevented, and a wide viewing angle of the antireflection function can be achieved. In this case, the retardation Rth(550) in the thickness direction 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, and particularly preferably -100 nm to -180 nm. Here, "nx = ny" includes not only the case where nx and ny are exactly 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.

[0040] The second retardation layer can be formed of any suitable material. The second retardation layer preferably comprises a film containing a liquid crystal material fixed in a homeotropic alignment. The 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 compounds and the method for forming the retardation layer described in paragraphs

[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, and still more preferably 0.5 μm to 5 μm.

[0041] D. Adhesive layer As described above, the adhesive layer 30 is composed of an active energy ray-curable adhesive. The curing shrinkage rate of the adhesive is typically 5% or more as described above, preferably 7% or more, more preferably 10% or more, and still more preferably 14% or more. The upper limit of the curing shrinkage rate of the adhesive can 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, and the front reflection hue a value and b value of the image display device in the initial stage (before being placed in a high-temperature environment) can be * a * b * shifted in advance in the direction of change in the high-temperature environment in the color space chromaticity diagram. Therefore, the change in reflection hue Δa * b * under high-temperature environment (for example, after the durability test) can be reduced. When annealing the laminate of the first retardation layer and the second retardation layer, even when the curing shrinkage rate of the adhesive is less than the above range (for example, 3%), the above-described effects may be obtained.

[0042] As the active energy ray-curable adhesive, any appropriate active energy ray-curable adhesive can be used as long as the curing shrinkage rate can be within the above range. Examples of the active energy ray-curable adhesive include an ultraviolet ray-curable adhesive and an electron beam-curable adhesive. Further, from the viewpoint of the curing mechanism, examples of the active energy ray-curable adhesive include a radical-curable type, a cation-curable type, an anion-curable type, and a hybrid of a radical-curable type and a cation-curable type. Typically, a radical-curable ultraviolet ray-curable adhesive can be used because of its excellent versatility and easy adjustment of characteristics (composition).

[0043] The active energy ray-curable adhesive typically contains a monofunctional component, a polyfunctional component (curing component), and a photopolymerization initiator. The monofunctional component and the polyfunctional component are each 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, acryloyl morpholine, and ε-caprolactone modified with an unsaturated fatty acid hydroxyalkyl ester. Preferred polyfunctional components include, for example, 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, trimethylolpropane triacrylate, and glycerin triacrylate. Specific examples of monofunctional components or polyfunctional components other than the above include tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, phenoxy diethylene glycol acrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, EO-modified diglycerin tetraacrylate, γ-butyrolactone acrylate, N-methylpyrrolidone, hydroxyethyl acrylamide, N-methylol acrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, and 9-vinylcarbazole. In one embodiment, the monofunctional component or the polyfunctional component has a ring structure. Specific examples include acryloyl morpholine, γ-butyrolactone acrylate, ε-caprolactone modified with an unsaturated fatty acid hydroxyalkyl ester, N-methylpyrrolidone, and 9-vinylcarbazole. The monofunctional component or the polyfunctional component may each be used alone or in combination of two or more thereof.

[0044] The active energy ray-curable adhesive may further contain a cationic polymerizable compound, if necessary. The cationic polymerizable compound may be monofunctional or polyfunctional. Examples of the monofunctional cationic polymerizable compound include p-tert-butylphenyl glycidyl ether and 3-ethyl-3-[(2-ethylhexyl)oxy]oxetane. Examples of the polyfunctional cationic polymerizable compound 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 the silane coupling agent include 3-glycidoxypropyltrimethoxysilane.

[0045] The active energy ray-curable adhesive may further contain an acrylic oligomer, if necessary. The molecular weight of the acrylic oligomer can be appropriately set according to the purpose.

[0046] The active energy ray-curable adhesive may further contain a plasticizer (e.g., oligomer component), a crosslinking agent, a diluent, etc., according to 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 photoinitiators, an active energy ray-curable adhesive having a desired curing shrinkage rate can be obtained. In addition, commercially available products may be used for each of the above components.

[0047] The thickness of the active energy ray-curable adhesive after curing is preferably 0.1 μm to 3.0 μm.

[0048] Details of the active energy ray-curable adhesive are described, for example, in JP-A-2018-017996. The description of the said publication is incorporated herein by reference.

[0049] E. Adhesive layer Regarding the first adhesive layer 40 and the second adhesive layer 50, since any appropriate adhesive can be used according to the purpose, detailed description thereof is omitted.

[0050] F. Method for manufacturing a polarizing plate with a phase difference layer Embodiments of the present invention also include the method for manufacturing the polarizing plate with a phase difference layer described above. This manufacturing method includes forming a first phase difference layer on a first base material, forming a second phase difference layer on a second base material, and laminating the first phase difference layer of the laminate of the first base material and the first phase difference layer and the second phase difference layer of the laminate of the second base material and the second phase difference layer through an active energy ray curable adhesive to form an intermediate laminate. Hereinafter, a representative example of the manufacturing method will be described with reference to FIG. 2.

[0051] First, as shown in Fig. 2(a), a first retardation layer 21 is formed on a first substrate 61. As the first substrate, any suitable resin film can be used. Specific examples include cellulose-based resin films such as triacetyl cellulose (TAC) films, polyester-based films such as polyethylene terephthalate (PET) films, and acrylic resin films. Preferably, it is a TAC film. The first retardation layer can typically be formed by subjecting the surface of the first substrate to an alignment treatment, applying a coating liquid containing a liquid crystal compound to the surface, aligning the liquid crystal compound in a direction corresponding to the alignment treatment, and fixing the alignment state. As the alignment treatment, any suitable alignment treatment can be adopted. Specifically, mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment can be mentioned. Specific examples of mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique evaporation method and photo-alignment treatment. The treatment conditions of various alignment treatments can be any suitable conditions according to the purpose. The alignment of the liquid crystal compound is performed by treating at a temperature at which the liquid crystal compound exhibits a liquid crystal phase according to the type of the liquid crystal compound. By performing such temperature treatment, the liquid crystal compound takes a liquid crystal state and the liquid crystal compound aligns according to the alignment treatment direction on the substrate surface. In one embodiment, the fixation of the alignment state is performed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is a polymerizable monomer or a crosslinkable monomer, the fixation of the alignment state is performed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or a crosslinking treatment. In this way, the first retardation layer 21 is formed on the first substrate 61.

[0052] On one hand, as shown in Fig. 2(b), a second retardation layer 22 is formed on a second substrate 62. As the second substrate, any suitable resin film can be used. Specific examples are the same as those 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 compounds and forming methods described in paragraphs

[0020] to

[0028] of JP-A-2002-333642. In this way, the second retardation layer 22 is formed on the second substrate 62.

[0053] Next, as shown in Fig. 2(c), the first retardation layer 21 and the second retardation layer 22 in each of the laminates obtained above are bonded together via an active energy ray-curable adhesive to form an intermediate laminate. The active energy ray-curable adhesive is as described in item 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 (typically, bonded to) the surface to form a precursor of the intermediate laminate, heated as necessary, and irradiated with a predetermined integrated amount of active energy rays (e.g., ultraviolet rays) to cure the adhesive, thereby forming the intermediate laminate. Here, the curing 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, when the intermediate laminate is formed, due to the shrinkage, Re(550) of the first retardation layer can be increased preferably by 0.5 nm or more, more preferably by 1.0 nm or more, still more preferably by 1.5 nm or more, particularly preferably by 2.5 nm or more, and most preferably by 3.0 nm or more. As a result, the initial (before being placed in a high-temperature environment) front reflection hue a value and b value of the image display device can be shifted in advance in the direction of change in the high-temperature environment in the L * a * b * chromaticity diagram of the color space. Therefore, the change in reflection hue Δa * b * under a high-temperature environment (e.g., after a durability test) can be reduced. However, when the annealing treatment described later is performed, the effects according to the embodiments of the present invention may be obtained even if the curing shrinkage rate is less than 5%.

[0054] 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, for example, 120° C. 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 the treatment time can be, for example, 20 minutes. By performing the annealing treatment, Re(550) of the first retardation layer can be increased preferably by 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, and especially preferably 3.0 nm or more. As a result, the front reflection hue a-value and b-value of the image display device in the initial stage (before being placed in a high-temperature environment) can be preliminarily shifted in the direction of change in the high-temperature environment in the L * a * b * color space chromaticity diagram. Therefore, the change in the reflection hue Δa * b * in the high-temperature environment (for example, after the durability test) can be reduced. However, when the curing shrinkage rate of the active energy ray-curable adhesive is 5% or more as described above, the effects according to the embodiments of the present invention may be obtained without performing the annealing treatment.

[0055] Preferably, an intermediate laminate can be formed using an active energy ray-curable adhesive having a curing shrinkage rate of 5% or more, and the intermediate laminate can be subjected to the annealing treatment. As a result, Re(550) of the first retardation layer can be further increased.

[0056] Next, as shown in FIG. 2(e), the first substrate 61 is peeled off from the intermediate laminate, the first adhesive layer 40 is disposed on the peeled surface (the surface of the first retardation layer 21), and a polarizing plate is bonded via the first adhesive layer 40. Since the polarizing plate can be produced by any suitable method, a detailed description of the manufacturing method of the polarizing plate is omitted. Practically, as shown in FIG. 2(f), the second substrate 62 is peeled off, and the second adhesive layer 50 is disposed on the peeled surface (the surface of the second retardation layer 22). For example, the second adhesive layer is formed on a release film (not shown), and a laminate of the second adhesive layer and the release film is disposed such that the second adhesive layer is in contact with the surface of the second retardation layer. In this way, a polarizing plate with a retardation layer can be produced. When using the polarizing plate with a retardation layer, the release film is removed.

[0057] G. Image Display Device The polarizing plate with a retardation layer described in Items A to F above can be applied to an image display device. Therefore, embodiments of the present invention include an image device using such a polarizing plate with a retardation layer. The image display device according to an embodiment of the present invention typically includes the polarizing plate with a retardation layer described in Items A to F above on its viewing side. The polarizing plate with a retardation layer is laminated such that the retardation layer faces the image display panel side (such that the polarizing plate faces the viewing side). Representative examples of the image display device include a liquid crystal display device, an organic electroluminescence (EL) display device, and an inorganic EL display device. In one embodiment, the image display device (e.g., an organic EL display device) has a curved shape (substantially a curved display screen) and / or is bendable or foldable.

Examples

[0058] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. The measurement methods for each characteristic are as follows. Unless otherwise specified, "parts" and "%" in the examples and comparative examples are based on weight.

[0059] (1) Curing Shrinkage Rate Regarding the UV-curable adhesives used in the examples and comparative examples, the curing shrinkage rate was measured using the resin curing shrinkage stress measuring device "EU201" manufactured by Sentec Co., Ltd. (2) Phase difference increase value Regarding the first phase difference layer (before producing the intermediate laminate) and the intermediate laminate (after annealing when annealed) produced in the examples and comparative examples, the in-plane phase difference was measured using a phase difference measuring device (product name "Axo Scan") manufactured by Axometrics Co., Ltd. The measurement wavelength of the in-plane phase difference was 550 nm, and the measurement temperature was 23°C. The difference between the in-plane phase difference of the intermediate laminate and the in-plane phase difference of the first phase difference layer before producing the intermediate laminate was defined as the "phase difference increase value". Note that the in-plane phase difference of the intermediate laminate is substantially the in-plane phase difference of the first phase difference layer in the laminate. (3) Δa * b * The polarizing plates with a phase difference layer obtained in the examples and comparative examples were bonded to a non-alkali glass plate to obtain test samples. The test samples were subjected to a durability test at 80°C for 500 hours. The test samples before and after the durability test were placed on a mirror surface plate, and the a value and b value were measured using a spectroscopic colorimeter / color difference meter "CM-26d" manufactured by Konica Minolta Co., Ltd., and the difference was defined as Δa * b * and.

[0060] [Production Examples 1 to 4: Preparation of UV-curable Adhesives A to D] Each component shown in Table 1 was blended at the ratio shown in Table 1 to prepare UV-curable adhesives A to D. The curing shrinkage rates of UV-curable adhesives A to D were as shown in Table 1. Note that the meanings of the terms shown in Table 1 are as follows. ACMO: Acryloylmorpholine manufactured by KJ Chemicals Co., Ltd. Placcel FA1DDM: Unsaturated fatty acid hydroxyalkyl ester-modified ε-caprolactone manufactured by Daicel Corporation ISTA: Isostearyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd. Light Acrylate L-A: Lauryl acrylate manufactured by Kyoeisha Chemical Co., Ltd. Light Acrylate 14EG-A: Polyethylene glycol diacrylate manufactured by Kyoeisha Chemical Co., Ltd. Light Acrylate TMP-A: Trimethylolpropane triacrylate manufactured by Kyoeisha Chemical Co., Ltd. Aronix M930: Glycerin triacrylate manufactured by Toagosei Co., Ltd. KBM-403: 3-Glycidoxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. EX-146: p-tert-Butylphenyl glycidyl ether manufactured by Nagase ChemteX Corporation OXT-212: 3-Ethyl-3-[(2-ethylhexyl)oxy]oxetane manufactured by Toagosei Co., Ltd. OXT-221: 3-Ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane manufactured by Toagosei Co., Ltd. ARUFON UP-1190: Manufactured by Toagosei Co., Ltd. ARUFON UG-4010: Manufactured by Toagosei Co., Ltd. Omnirad 819: Manufactured by IGM resins CPI-110P: Manufactured by San-Apro Ltd.

[0061]

Table 1

[0062] [Example 1] 1. Preparation of polarizer As the thermoplastic resin substrate, an amorphous isophthalic acid copolymerized polyethylene terephthalate film (thickness: 100 μm) that is long, has a water absorption rate of 0.75%, and a Tg of about 75°C was used. One side of the resin substrate was subjected to corona treatment. To 100 parts by weight of a PVA-based resin obtained by mixing polyvinyl alcohol (degree of polymerization 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Gosei Chemical Industry Co., Ltd., trade name "Gosefimer Z410") in a ratio of 9:1, 13 parts by weight of potassium iodide was added and dissolved in water to prepare a PVA aqueous solution (coating solution). The PVA aqueous solution was applied to the corona-treated surface of the resin substrate and dried at 60°C to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (length direction) between rolls with different peripheral speeds in an oven at 130°C (air-assisted stretching treatment). Next, the laminate was immersed in an insolubilization bath at a liquid temperature of 40°C (an aqueous boric acid solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment). Next, the laminate was immersed in a dyeing bath at a liquid temperature of 30°C (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) for 60 seconds while adjusting the concentration so that the single transmittance (Ts) of the finally obtained polarizing film became a desired value (dyeing treatment). Next, the laminate was immersed in a crosslinking bath at a liquid temperature of 40°C (an aqueous boric acid solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (crosslinking treatment). Thereafter, while immersing the laminate in an aqueous boric acid solution at a liquid temperature of 70°C (boric acid concentration 4.0% by weight, potassium iodide 5.0% by weight), uniaxial stretching was performed in the longitudinal direction (length direction) between rolls with different peripheral speeds so that the total stretching ratio became 5.5 times (stretching treatment in water). Thereafter, the laminate was immersed in a washing bath at a liquid temperature of 20°C (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) (washing treatment). Thereafter, while drying in an oven maintained at 90°C, it was brought into contact with a SUS heating roll whose surface temperature was maintained at 75°C for about 2 seconds (dry shrinkage treatment). The shrinkage rate in the width direction of the laminate due to the dry shrinkage treatment was 5.2%. In this way, a polarizer with a thickness of 5 μm was formed on the resin substrate.

[0063] 2. Production of a polarizing plate An HC-COP film was laminated on the surface of the polarizer of the resin substrate / polarizer laminate obtained above through an ultraviolet-curable adhesive. Specifically, the curable adhesive was applied so that its thickness was 1.0 μm, and then laminated using a roll machine. Thereafter, UV light was irradiated from the HC-TAC film side to cure the adhesive. The HC-COP film is a film in which a hard coat (HC) layer (thickness 2 μm) is formed on a cyclic olefin resin (COP) film (thickness 25 μm), and the COP film was laminated so as to be on the polarizer side. Next, the resin substrate was peeled off, and a TAC film having Re(550) of about 0 nm to 2 nm was laminated on the peeled surface in the same manner as above. In this way, a polarizing plate was obtained.

[0064] Preparation of a liquid crystal alignment cured layer constituting the retardation layer 3-1. First retardation layer 55 parts of the compound represented by formula (I), 25 parts of the compound represented by formula (II), and 20 parts of the compound represented by formula (III) were added to 400 parts of cyclopentanone (CPN), and then heated to 60 °C and stirred to dissolve. After dissolution was confirmed, the temperature was returned to room temperature, 3 parts of Irgacure 907 (manufactured by BASF Japan Ltd.), 0.2 part of Megafac F-554 (manufactured by DIC Corporation), and 0.1 part of p-methoxyphenol (MEHQ) were added, and further stirring was carried out to obtain a solution. The solution was transparent and uniform. The obtained solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. On the other hand, a polyimide solution for an 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 obtained coating film was subjected to rubbing treatment to form an alignment film. The rubbing treatment was performed using a commercially available rubbing apparatus. 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 the obtained coating film was cooled to room temperature, ultraviolet light was irradiated using a high-pressure mercury lamp at an intensity of 30 mW / cm 2 for 30 seconds to obtain a liquid crystal alignment cured layer (thickness 4 μm). The in-plane retardation Re(550) of the liquid crystal alignment cured layer was 130 nm. Also, Re(450) / Re(550) of the liquid crystal alignment cured layer was 0.851, showing reverse dispersion wavelength characteristics.

[0065] [Chemical formula] [Chemical formula]

[0066] 3-2. Second retardation layer 20 parts by weight of a side-chain liquid crystal polymer represented by the following chemical formula (1) (the numbers 65 and 35 in the formula represent mol% of monomer units and are represented as a block polymer for convenience: weight average molecular weight 5000), 80 parts by weight of a polymerizable liquid crystal showing 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 dissolved in 200 parts by weight of cyclopentanone to prepare a liquid crystal coating solution. Then, the coating solution was applied to a vertically aligned PET substrate by a bar coater, and the liquid crystal was aligned by heating and drying at 80°C for 4 minutes. The liquid crystal layer was irradiated with ultraviolet rays to cure the liquid crystal layer, thereby forming a second retardation layer (thickness 3 μm) showing a refractive index characteristic of nz>nx=ny on the substrate. [Chemical formula]

[0067] 4. Fabrication of a polarizing plate with a retardation layer The first retardation layer and the second retardation layer in each of the laminate obtained in the above 3-1. and 3-2. were bonded together via a UV adhesive A (thickness after curing: 1 μm) to form an intermediate laminate. This intermediate laminate was subjected to an annealing treatment at 100 °C for 10 minutes. The TAC substrate was peeled off from the annealed intermediate laminate, and an acrylic adhesive (thickness: 5 μm) was disposed on the surface of the first retardation layer, and a polarizing plate was bonded via the acrylic adhesive. At this time, the polarizing plate was bonded 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 adhesive (thickness: 26 μm) / release film was disposed 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 in the above (3). The results are shown in Table 2.

[0068] [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. The results are shown in Table 2. In addition, "none" in the column of the annealing treatment in Table 2 indicates that the annealing treatment was not performed.

[0069]

Table 2

[0070] [Evaluation] As is clear from Table 2, the polarizing plate with a retardation layer of the examples of the present invention has a smaller Δa * b * than the comparative examples. That is, it can be seen that the polarizing plate with a retardation layer of the examples of the present invention can realize an image display device in which the change in the reflected color phase in a high-temperature environment is suppressed.

Industrial Applicability

[0071] The polarizing plate with a retardation layer of the present invention is suitably used as a circular polarizing plate for preventing reflection in an image display device.

Explanation of Signs

[0072] 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 Polarizing plate with retardation layer

Claims

1. A polarizing plate including a polarizer and at least one protective layer on at least one of the polarizers, a first retardation layer disposed on the side opposite to the visible side of the polarizing plate, and a second retardation layer bonded via an adhesive layer to the side opposite to the polarizing plate of the first retardation layer, wherein the first retardation layer is a retardation layer other than a C-plate, and the second retardation layer is a C-plate, and a laminate of the first retardation layer and the second retardation layer is annealed. A polarizing plate with a retardation layer.

2. The first retardation layer exhibits a refractive index characteristic of nx > ny ≥ nz, Re(550) is from 100 nm to 200 nm, and satisfies the relationship of Re(450) < Re(550), and the second retardation layer exhibits a refractive index characteristic of nz > nx = ny. The polarizing plate with a retardation layer according to Claim 1: Here, Re(450) and Re(550) are the in-plane retardations measured with light of wavelengths 450 nm and 550 nm at 23°C, respectively.

3. The polarizing plate with a retardation layer according to Claim 2, wherein the first retardation layer and the second retardation layer are alignment and curing layers of a liquid crystal compound.

4. A method for manufacturing the polarizing plate with a retardation layer according to Claim 1, comprising: forming the first retardation layer on a first substrate, forming the second retardation layer on a second substrate, bonding the first retardation layer of the laminate of the first substrate and the first retardation layer and the second retardation layer of the laminate of the second substrate and the second retardation layer via an active energy ray curable adhesive to form an intermediate laminate, and annealing the intermediate laminate. A manufacturing method including the above steps.

5. The manufacturing method according to Claim 4, wherein the annealing treatment temperature is 80°C or higher and the treatment time is 1 minute or longer.

6. The manufacturing method according to Claim 4 or 5, including increasing Re(550) of the first retardation layer by 0.5 nm or more by the annealing treatment.

7. An image display device including the polarizing plate with a retardation layer according to any one of Claims 1 to 3.

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