Polarizing plate with phase difference layer attached and method of manufacturing the same, and image display device using the polarizing plate with phase difference layer attached said phase difference layer

Abstract

The present invention provides a polarizing plate with a phase difference layer attached, which can realize an image display device in which changes in reflection color under high temperature environments are suppressed. A polarizing plate with a phase difference layer attached according to an embodiment of the present invention comprises a polarizing plate including a polarizer and a protective layer on at least one of the polarizers, a first phase difference layer disposed on the side opposite to the viewing side of the polarizing plate, and a second phase difference layer laminated with an adhesive layer interposed on the side opposite to the polarizing plate of the first phase difference layer. The first phase difference layer is a phase difference layer other than a C-plate, and the second phase difference layer is a C-plate. In one embodiment, the adhesive layer is composed of an active energy beam curable adhesive, and the curing shrinkage rate of the adhesive is 5% or more. In another embodiment, the laminate of the first phase difference layer and the second phase difference layer is annealed.

Description

Technology Field

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

[0002] Recently, image display devices, represented by liquid crystal displays and electroluminescence (EL) displays (e.g., organic EL displays, inorganic EL displays), have been rapidly gaining popularity. Polarizers and phase difference plates are typically used in image display devices. In practical terms, polarizers with a phase difference layer attached, which integrate a polarizer and a phase difference plate, are widely used. However, as the demand for thinning image display devices has recently intensified, there is also a strong demand for thinning of polarizers with a phase difference layer attached. As one approach to thinning polarizers with a phase difference layer attached, a polarizer with a phase difference layer attached that utilizes a fixed phase difference layer while the liquid crystal compound is oriented has been proposed. However, image display devices using such polarizers with a phase difference layer attached have a problem in that the reflection color changes significantly under high-temperature environments. Prior art literature

[0003] Japanese Patent Publication No. 2020-064274 The problem to be solved

[0004] The present invention is made to solve the aforementioned conventional problems, and its main objective is to provide a polarizing plate with a phase difference layer attached that can realize an image display device in which changes in reflection color under high-temperature environments are suppressed. means of solving the problem

[0005] A polarizing plate with a phase difference layer attached according to an embodiment of the present invention comprises a polarizing plate including a polarizer and a protective layer on at least one of the polarizers, a first phase difference layer disposed on the side opposite to the viewing side of the polarizing plate, and a second phase difference layer laminated with an adhesive layer interposed on the side opposite to the polarizing plate of the first phase difference layer. The first phase difference layer is a phase difference layer other than a C-plate, and the second phase difference layer is a C-plate. In one embodiment, the adhesive layer is composed of an active energy beam curing adhesive, and the curing shrinkage rate of the adhesive is 5% or more. In another embodiment, the laminate of the first phase difference layer and the second phase difference layer is annealed.

[0006] In one embodiment, the first phase difference layer exhibits refractive index characteristics of nx > ny ≥ nz, Re (550) is 100 nm to 200 nm, and also Re (450)<Re(550)의 관계를 만족하며; 상기 제2 위상차층은 nz> It represents the refractive index characteristic of nx=ny. Here, Re(450) and Re(550) are the in-plane phase difference measured with light of wavelengths 450 nm and 550 nm at 23°C, respectively.

[0007] In one embodiment, the first phase difference layer and the second phase difference layer are orientation solidification layers of a liquid crystal compound.

[0008] According to another aspect of the present invention, a method for manufacturing a polarizing plate with a phase difference layer attached is provided. The manufacturing method comprises forming the first phase difference layer on a first substrate, forming the second phase difference layer on a second substrate, and forming an intermediate laminate by laminating the first phase difference layer of the laminate of the first substrate and the first phase difference layer and the second phase difference layer of the laminate of the second substrate and the second phase difference layer through an active energy beam curable adhesive.

[0009] In one embodiment, the curing shrinkage rate of the active energy beam curable adhesive is 5% or more. In this case, the manufacturing method includes increasing the Re (550) of the first phase difference layer by 0.5 nm or more when forming the intermediate laminate.

[0010] In another embodiment, the manufacturing method further comprises annealing the intermediate laminate. In this case, the manufacturing method comprises increasing the Re (550) of the first phase difference 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 higher.

[0011] According to a further aspect of the present invention, an image display device is provided. The image display device comprises a polarizing plate with a phase difference layer attached as described above. Effects of the invention

[0012] According to an embodiment of the present invention, a polarizing plate with a phase difference layer attached can be obtained to realize an image display device in which changes in reflection color under a high-temperature environment are suppressed. Brief explanation of the drawing

[0013] FIG. 1 is a schematic cross-sectional view of a polarizing plate with a phase difference layer attached according to one embodiment of the present invention. FIG. 2 is a flowchart including a schematic cross-sectional view illustrating the manufacturing process of a polarizing plate with a phase difference layer attached according to an embodiment of the present invention. Specific details for implementing the invention

[0014] Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

[0015] (Definition of Terms and Symbols)

[0016] The definitions of terms and symbols in this specification are as follows.

[0017] (1) Refractive index (nx, ny, nz)

[0018] 'nx' is the refractive index in the direction where the refractive index in the plane is maximum (i.e., the ground axis direction), 'ny' is the refractive index in the direction perpendicular to the ground axis in the plane (i.e., the true axis direction), and 'nz' is the refractive index in the thickness direction.

[0019] (2) In-plane phase difference (Re)

[0020] 'Re(λ)' is the in-plane phase difference measured with light of wavelength λ nm at 23°C. For example, 'Re(550)' is the in-plane phase difference measured with light of wavelength 550 nm at 23°C. Re(λ) can be calculated by the formula: Re(λ)=(nx-ny)×d, where the thickness of the layer (film) is d(nm).

[0021] (3) Phase difference in the thickness direction (Rth)

[0022] 'Rth(λ)' is the phase difference in the thickness direction measured with light of wavelength λnm at 23°C. For example, 'Rth(550)' is the phase difference in the thickness direction measured with light of wavelength 550nm at 23°C. Rth(λ) can be calculated by the formula: Rth(λ)=(nx-nz)×d, where the thickness of the layer (film) is d(nm).

[0023] (4) Nz coefficient

[0024] The Nz coefficient can be calculated using the formula Nz = Rth / Re.

[0025] (5) Angle

[0026] When referring to an angle in this specification, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. Accordingly, for example, '45°' means ±45°.

[0027] A. Overall configuration of the polarizer with phase difference layer attached

[0028] FIG. 1 is a schematic cross-sectional view of a polarizing plate with a phase difference layer attached according to one embodiment of the present invention. The polarizing plate (100) with a phase difference layer attached in the illustrated example typically includes a polarizing plate (10), a first phase difference layer (21), and a second phase difference 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 side of the polarizer (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 side of the viewing side protective layer (12) or the inner protective layer (13) may be omitted depending on the purpose, etc. The first phase difference layer (21) is typically laminated with a first adhesive layer (40) interposed on the side opposite to the viewing side of the polarizing plate (10). The second phase difference layer (22) is laminated with an adhesive layer (30) interposed on the opposite side of the polarizing plate (10) of the first phase difference layer (21).

[0029] In an embodiment of the present invention, the first phase difference layer (21) is a phase difference layer other than a C plate, and the second phase difference layer (22) is a C plate. The first phase difference layer (21) typically exhibits a refractive index characteristic of nx > ny ≥ nz. That is, the first phase difference layer may be a positive A plate (nx > ny = nz) or a negative B plate (nx > ny > nz). Additionally, the first phase difference layer has a Re (550) preferably of 100 nm to 200 nm, and preferably Re (450)<Re(550)의 관계를 만족한다. 제2 위상차층(22)은, 대표적으로는 nz> It exhibits the refractive index characteristic of nx=ny. That is, the second phase difference layer may be a positive C plate. If the first phase difference layer and the second phase difference layer have such a configuration, a polarizer with a phase difference layer attached having excellent anti-reflection characteristics can be realized.

[0030] The first phase difference layer and the second phase difference layer are, typically, an alignment solidification layer of a liquid crystal compound (hereinafter, it may be simply referred to as a liquid crystal alignment solidification layer). By using a liquid crystal compound, the difference between nx and ny of the obtained phase difference layer can be made significantly larger compared to non-liquid crystal materials, so the thickness of the first phase difference layer required to obtain a desired in-plane phase difference can be significantly reduced. In addition, the second phase difference layer (positive C plate) can be formed with a very thin thickness. As a result, further thinning of the polarizer with the phase difference layer attached can be realized. In this specification, "alignment solidification layer" refers to a layer in which a liquid crystal compound is oriented in a predetermined direction within the layer and its alignment state is fixed. In addition, "alignment curing layer" is a concept that includes an alignment curing layer obtained by curing a liquid crystal monomer. The first phase difference layer is, typically, a rod-shaped liquid crystal compound oriented in a state arranged along the ground axis direction of the phase difference layer (homogeneous alignment); The second phase difference layer typically consists of rod-shaped liquid crystal compounds oriented perpendicularly to the film plane (homeotropic orientation).

[0031] In an embodiment of the present invention, the adhesive layer (30) is composed of an active energy beam curing adhesive. The curing shrinkage rate of the adhesive is typically 5% or more. Additionally / or the laminate of the first phase difference layer and the second phase difference layer is typically annealed. With such a configuration, the Re (550) of the laminate of the first phase difference layer and the second phase difference layer (substantially the first phase difference layer) can be increased compared to cases where the curing shrinkage rate of the adhesive is small and / or where the laminate of the first phase difference layer and the second phase difference layer is not annealed. As a result, the front reflection color values ​​a and b of the image display device at the beginning (before being placed in a high-temperature environment) are L * a * b *In the color space chromaticity diagram, it can be pre-shifted in the direction of change under high-temperature environments. Therefore, the change in reflective color Δa under high-temperature environments (e.g., after a durability test) * b * can be reduced. This effect is pronounced when the phase difference layer is a liquid crystal alignment solidification layer. That is, the liquid crystal alignment solidification layer is susceptible to the dimensional shrinkage of the polarizer under high-temperature environments, and compared to the phase difference layer of a resin film, the change in reflection color Δa * b * There is a tendency for it to be large. Here, by shifting the initial frontal reflection color values ​​a and b in advance in the direction of change under a high-temperature environment as described above (by experiencing the effect of dimensional shrinkage in advance), the effect of dimensional shrinkage of the polarizer under a high-temperature environment can be reduced, and as a result, the reflection color change Δa * b * It can be made smaller.

[0032] In practical terms, a second adhesive layer is provided on the side opposite to the polarizing plate (10) of the second phase difference layer (22) (i.e., as the outermost layer opposite to the viewing side), and the polarizing plate with the phase difference layer attached can be attached to an image display panel. Additionally, it is preferable that a release film (not shown) be attached to the surface of the second adhesive layer (50) until the polarizing plate with the phase difference layer attached is provided for use. By attaching the release film, the second adhesive layer (50) is protected, and at the same time, the polarizing plate with the phase difference layer attached can be rolled up.

[0033] The total thickness of the polarizing plate with the phase difference layer attached is preferably 120 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. The lower limit of the total thickness may be, for example, 45 μm. A polarizing plate with a phase difference layer attached having such a total thickness may have excellent flexibility and bending durability. As a result, the polarizing plate with the phase difference layer attached can be particularly suitable for application to a curved image display device and / or a bendable or foldable image display device. Furthermore, the total thickness of the polarizing plate with the phase difference layer attached refers to the sum of the thickness from the viewing side protective layer (12) (if present) to the second phase difference layer (22). That is, the total thickness of the polarizing plate with the phase difference layer attached does not include the thickness of the second adhesive layer (50).

[0034] The polarizing plate with the phase difference layer attached may further include other optical functional layers. The type, characteristics, number, combination, and placement location of the optical functional layers that may be provided in the polarizing plate with the phase difference layer attached can be appropriately set according to the purpose. For example, the polarizing plate with the phase difference layer attached may further include a conductive layer or an isotropic substrate attached to a conductive layer (not all shown). The conductive layer or the isotropic substrate attached to a conductive layer is typically provided on the outer side of the second phase difference layer (22) (on the side opposite to the polarizing plate (10)). When the conductive layer or the isotropic substrate attached to a conductive layer is provided, the polarizing plate with the phase difference layer attached may be applied to a so-called inner touch panel type input display device in which a touch sensor is embedded between the image display panel and the polarizing plate. In addition, for example, the polarizing plate with the phase difference layer attached may further include other phase difference layers. Other optical properties of the phase difference layer (e.g., refractive index properties, in-plane phase difference, Nz modulus, photoelastic modulus), thickness, placement position, etc., can be appropriately set according to the purpose.

[0035] A polarizer with a phase difference layer attached may be in the form of a single sheet or a long sheet. In this specification, "long sheet" refers to an elongated shape in which the length is sufficiently long relative to the width, and includes, for example, an elongated shape in which the length is 10 times or more, preferably 20 times or more, relative to the width. A polarizer with a phase difference layer attached in the long sheet shape can be wound into a roll.

[0036] Below, the components of the polarizing plate with the phase difference layer attached will be explained in more detail.

[0037] B. Polarizing plate

[0038] B-1. Polarizer

[0039] Any suitable polarizer may be used 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.

[0040] Specific examples of a polarizer composed of a single-layer resin film include a hydrophilic polymer film, such as a polyvinyl alcohol (PVA)-based film, a partially formalized PVA-based film, or a partially saponified ethylene-vinyl acetate copolymer-based film, to which a dyeing treatment with a dichroic substance such as iodine or a dichroic dye and a stretching treatment have been performed, and a polyene-based oriented film, such as a dehydrated PVA or a dehydrochlorinated 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.

[0041] The above iodine dyeing is performed, for example, by immersing a PVA-based film in an aqueous iodine solution. The stretching ratio of the above uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. In addition, dyeing may be performed after stretching. If necessary, swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc., are performed on the PVA-based film. For example, by immersing the PVA-based film in water and washing it before dyeing, not only can contamination or anti-blocking agents on the surface of the PVA-based film be cleaned, but the PVA-based film can also be swollen to prevent dye stains.

[0042] Specific examples of polarizers 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 polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer applied and formed on the resin substrate. A polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer applied and formed on the resin substrate can be manufactured, for example, by applying a PVA-based resin solution to a 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; and by stretching and dyeing the laminate to make the PVA-based resin layer into a polarizer. In the present embodiment, stretching typically includes stretching the laminate by immersing it in an aqueous boric acid solution. Additionally, stretching may further include, if necessary, air-stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. The obtained resin substrate / polarizer laminate may be used as is (i.e., 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 and any suitable 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 Japanese Patent Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0043] The thickness of the polarizer is preferably 15 μm or less, more preferably 12 μm or less, even more preferably 10 μm or less, and particularly preferably 8 μm or less. Meanwhile, 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 this range, curling during heating can be effectively suppressed, and good durability of the appearance during heating is obtained.

[0044] The polarizer preferably exhibits absorption dichroism at any one of the wavelengths from 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 polarization degree of the polarizer is preferably 97.0% or higher, more preferably 99.0% or higher, and even more preferably 99.9% or higher.

[0045] B-2. Protective layer

[0046] The protective layer on the viewing side (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 materials that serve as the main components of the film include cellulose-based resins such as triacetylcellulose (TAC), or transparent resins such as 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, and acetate-based resins. In addition, thermosetting resins or UV-curing resins such as (meth)acrylic-based, urethane-based, (meth)acrylicurethane-based, epoxy-based, and silicone-based resins may also be used. Furthermore, glassy polymers such as siloxane-based polymers may also be used. In addition, a polymer film described in Japanese Patent Publication No. 2001-343529 (WO01 / 37007) may also be used. As a material for this film, a resin composition containing, for example, a thermoplastic resin having substituted or unsubstituted imide groups in a side chain and a thermoplastic resin having substituted or unsubstituted phenyl groups and nitrile groups in a side chain may be used, and for example, a resin composition having an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer may be used. The polymer film may, for example, be an extruded product of the above resin composition.

[0047] As described below, the polarizing plate with a phase difference layer is typically placed on the viewing side of an image display device, and the viewing side protective layer (12) is placed on the viewing side. Accordingly, the viewing side protective layer (12) may be subjected to surface treatments such as hard coating, anti-reflection, anti-sticking, and anti-glare treatment as needed. Additionally / or, the viewing side protective layer (12) may be subjected to treatments that improve visibility when viewed through polarized sunglasses (typically providing an (elliptical) polarization function or providing an ultra-high phase difference) as needed. By performing such treatments, excellent visibility can be achieved even when viewing the display screen through polarized lenses such as polarized sunglasses. Therefore, the polarizing plate with a phase difference layer can be suitably applied to an image display device that can be used outdoors. Furthermore, as a material constituting the viewing side protective layer, preferably a cyclic olefin-based (e.g., polynorbornene-based) or cellulose-based resin (e.g., TAC) may be used.

[0048] The thickness of the protective layer (12) on the visible side is preferably 5㎛ to 80㎛, more preferably 10㎛ to 40㎛, and even more preferably 10㎛ to 30㎛. In addition, if surface treatment is performed, the thickness of the protective layer on the visible side is the thickness including the thickness of the surface treatment layer.

[0049] In one embodiment, the inner protective layer (13) is preferably optically isotropic. In this specification, "optically isotropic" means that the in-plane phase difference Re (550) is 0 nm to 10 nm and the thickness direction phase difference 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. The materials constituting the inner protective layer may preferably be cyclic olefin-based (e.g., polynorbornene-based), cellulose-based resin (e.g., TAC), or acrylic-based resin.

[0050] C. Phase difference layer

[0051] C-1. First phase difference layer

[0052] The first phase difference layer (21) can function, typically, as a λ / 4 plate. The first phase difference layer is provided, typically, to impart anti-reflection properties to an image display device. The first phase difference layer, typically, exhibits refractive index properties of nx > ny ≥ nz as described above. The in-plane phase difference Re (550) of the first phase difference 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. Furthermore, 'ny=nz' here includes not only cases where ny and nz are completely identical but also cases where they are substantially identical. Therefore, within a range that does not impair the effects of the present invention, ny > nz or ny <nz가 되는 경우가 있을 수 있다.

[0053] The Nz coefficient of the phase difference layer is preferably 0.9 to 1.5, and more preferably 0.9 to 1.3. By satisfying this relationship, an image display device having a very excellent reflective color can be obtained.

[0054] The first phase difference layer preferably exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measurement light. That is, the first phase difference layer preferably Re(450) as described above <Re(550)의 관계를 만족한다. 제1 위상차층은, 바람직하게는 Re(550)<Re(650)의 관계를 더욱 만족한다. 제1 위상차층의 Re(450) / Re(550)는, 바람직하게는 0.8 이상 1 미만이고, 보다 바람직하게는 0.8 이상 0.95 이하이다. 제1 위상차층의 Re(650) / Re(550)는, 바람직하게는 1.0 이상 1.15 미만이고, 보다 바람직하게는 1.03~1.1이다. 이와 같은 구성이면, 매우 우수한 반사 방지 특성을 실현할 수 있다.

[0055] The angle formed by the ground axis of the phase difference 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 this range, an image display device having excellent anti-reflection characteristics can be obtained by making the phase difference layer a λ / 4 plate as described above.

[0056] The first phase difference layer can be, for example, 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 phase difference layer can be made significantly larger compared to non-liquid crystal materials, so the thickness of the first phase difference layer for obtaining a desired in-plane phase difference can be significantly reduced. The first phase difference layer is, for example, oriented such that rod-shaped liquid crystal compounds are aligned along the ground axis direction of the phase difference layer (homogeneous orientation).

[0057] Examples of liquid crystal compounds include liquid crystal compounds in which the liquid crystal phase is the nematic phase (nematic liquid crystal). Examples of such liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The mechanism of liquid crystallization of the liquid crystal compound may be either lyotropic or thermotropic. Liquid crystal polymers and liquid crystal monomers may each be used individually or in combination.

[0058] When the liquid crystal compound is a liquid crystal monomer, it is preferable that the liquid crystal monomer be a polymerizable monomer and a crosslinkable monomer. This is because the orientation state of the liquid crystal monomer can be fixed by polymerizing or crosslinking (i.e., curing) the liquid crystal monomer. After orienting the liquid crystal monomer, if the liquid crystal monomers are, for example, polymerized or crosslinked together, the orientation state can be fixed. Here, a polymer is formed by polymerization and a three-dimensional network structure is formed by crosslinking, but these are non-liquid. Therefore, the formed first phase difference layer does not undergo a transition to a liquid crystal phase, glass phase, or crystalline phase due to temperature changes characteristic of, for example, liquid crystal compounds. As a result, the first phase difference layer becomes a phase difference layer with excellent stability that is not affected by temperature changes.

[0059] The temperature range in which a liquid crystal monomer exhibits liquid crystal properties varies depending on the type thereof. 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.

[0060] Any suitable liquid crystal monomer may be used as the liquid crystal monomer. For example, polymerizable mesogen compounds described in Japanese Patent Application Publication No. 2002-533742 (WO00 / 37585), EP358208 (US5211877), EP66137 (US4388453), WO93 / 22397, EP0261712, DE19504224, DE4408171 and GB2280445, etc. may be used.

[0061] The thickness of the first phase difference layer can be set to a thickness that can function appropriately, typically as a λ / 4 plate. The thickness of the first phase difference layer is preferably 0.5 μm to 7 μm, and more preferably 1 μm to 5 μm. By using a liquid crystal compound, an in-plane phase difference equivalent to that of a resin film can be realized with a thickness significantly thinner than that of a resin film.

[0062] C-2. Second phase difference layer

[0063] The second phase difference layer (22) may be a positive C plate having a refractive index characteristic of nz > nx = ny as described above. By using a positive C plate as the second phase difference layer, reflection in the oblique direction can be effectively prevented, thereby enabling a wide viewing angle of the anti-reflection function. In this case, the phase difference Rth (550) in the thickness direction of the second phase difference layer is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, even more preferably -90 nm to -200 nm, and particularly preferably -100 nm to -180 nm. Here, 'nx=ny' includes not only cases where nx and ny are strictly identical but also cases where nx and ny are substantially identical. That is, the in-plane phase difference Re (550) of the second phase difference layer may be less than 10 nm.

[0064] The second phase difference layer may be formed from any suitable material. The second phase difference layer preferably comprises a film containing a liquid crystal material fixed to homeotropic orientation. The liquid crystal material capable of homeotropic orientation (liquid crystal compound) may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the phase difference layer include the liquid crystal compound and the method for forming the phase difference layer described in

[0020] to

[0028] of Japanese Patent Publication No. 2002-333642. In this case, the thickness of the second phase difference layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 8 μm, and even more preferably 0.5 μm to 5 μm.

[0065] D. Adhesive layer

[0066] The adhesive layer (30) is composed of an active energy beam curing adhesive as described above. 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 even more preferably 14% or more. The upper limit of the curing shrinkage rate of the adhesive may be, for example, 20%. With such a configuration, the Re (550) of the laminate of the first phase difference layer and the second phase difference layer (substantially, the first phase difference layer) can be increased, so that the front reflection color values ​​a and b of the image display device at the beginning (before being placed under a high-temperature environment) are L * a * b * In the color space chromaticity diagram, in the direction of change under high-temperature environments, in advance It can be shifted. Therefore, the change in reflective color Δa under high-temperature environments (e.g., after durability testing) * b * The above effect can be reduced. In addition, when annealing a laminate of the first phase difference layer and the second phase difference layer, even if the curing shrinkage rate of the adhesive is smaller than the above range (e.g., 3%), the above effect may be obtained.

[0067] As an active energy beam curing adhesive, any suitable active energy beam curing adhesive may be used as long as the curing shrinkage rate is within the above range. Examples of active energy beam curing adhesives include ultraviolet (UV) curing adhesives and electron beam curing adhesives. Furthermore, regarding the curing mechanism, examples of active energy beam curing adhesives include radical curing type, cationic curing type, anionic curing type, and hybrids of radical curing type and cationic curing type. Representatively, a radical curing type UV curing adhesive may be used. This is because it has excellent versatility and is easy to adjust the properties (composition).

[0068] Active energy beam curing adhesives typically contain a monofunctional component, a polyfunctional component (curing component), and a photopolymerization initiator. The monofunctional component and the polyfunctional component are each typically radical polymerizable compounds. Preferred monofunctional components include, for example, higher alkyl esters of (meth)acrylic acid and their modified forms. Specific examples include isostearyl acrylate, lauryl acrylate, acryloylmorpholine, and ε-caprolactone modified by unsaturated fatty acid hydroxyalkyl esters. 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, trimethylpropane triacrylate, and glycerin triacrylate. Specific examples of monofunctional or polyfunctional components other than those mentioned above include tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecanedimethanol diacrylate, phenoxydiethylene glycol acrylate, cyclic trimethylolpropaneformal acrylate, dioxane glycol diacrylate, EO-modified diglycerin tetraacrylate, γ-butyrolactone acrylate, N-methylpyrrolidone, hydroxyethylacrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, and 9-vinylcarbazole. In one embodiment, the monofunctional or polyfunctional component has a ring structure. Specific examples include acryloylmorpholine, γ-butyrolactone acrylate, ε-caprolactone modified by an unsaturated fatty acid hydroxyalkyl ester, N-methylpyrrolidone, and 9-vinylcarbazole. Monofunctional components or polyfunctional components may each be used alone, or two or more may be used in combination.

[0069] The active energy beam curing adhesive may further include a cationic polymerizable compound as needed. The cationic polymerizable compound may be monofunctional or polyfunctional. Examples of monofunctional cationic polymerizable compounds include p-tert-butylphenylglycidyl ether and 3-ethyl-3-[(2-ethylhexyl)oxy]oxetane. Examples of polyfunctional cationic polymerizable compounds include 3-ethyl-3-{[(3-ethyloxetane-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.

[0070] The active energy beam curing adhesive may further contain an acrylic oligomer as needed. The molecular weight of the acrylic oligomer can be appropriately set according to the purpose.

[0071] Active energy beam curable adhesives may further contain plasticizers (e.g., oligomer components), crosslinking agents, diluents, etc., depending on the purpose. By adjusting the types, combinations, and mixing ratios of these components, the monofunctional components, polyfunctional components, cationic polymerizable compounds, acrylic oligomers, and photopolymerization initiators, active energy beam curable adhesives having a desired curing shrinkage rate can be obtained. Additionally, commercially available products may be used for each of the above components.

[0072] The thickness of the active energy beam curable adhesive after curing is preferably 0.1㎛ to 3.0㎛.

[0073] Details of active energy beam curing adhesives are described, for example, in Japanese Patent Publication No. 2018-017996. The description in said publication is incorporated herein by reference.

[0074] E. Adhesive layer

[0075] For the first adhesive layer (40) and the second adhesive layer (50), any suitable adhesive can be used depending on the purpose, so a detailed description is omitted.

[0076] F. Method for manufacturing a polarizing plate with a phase difference layer

[0077] An embodiment of the present invention also includes a method for manufacturing a polarizing plate with a phase difference layer attached as described above. This manufacturing method comprises forming a first phase difference layer on a first substrate, forming a second phase difference layer on a second substrate, and forming an intermediate laminate by laminating the first phase difference layer of the laminate of the first substrate and the first phase difference layer and the second phase difference layer of the laminate of the second substrate and the second phase difference layer through an active energy beam curable adhesive. Hereinafter, a representative example of the manufacturing method will be described with reference to FIG. 2.

[0078] First, as shown in FIG. 2(a), a first phase difference layer (21) is formed on a first substrate (61). Any suitable resin film may be used as the first substrate. Specific examples include a cellulose-based resin film such as a triacetylcellulose (TAC) film, a polyester-based film such as a polyethylene terephthalate (PET) film, and an acrylic-based resin film. Preferably, it is a TAC film. The first phase difference layer can be formed by typically performing an orientation treatment on the surface of the first substrate, coating the surface with a coating solution containing a liquid crystal compound to orient the liquid crystal compound in a direction corresponding to the orientation treatment, and fixing the orientation state. Any suitable orientation treatment may be used as the orientation treatment. Specifically, mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment may be used. Specific examples of mechanical orientation treatment include rubbing treatment and stretching treatment. Specific examples of physical orientation treatments include magnetic field orientation treatment and electric field orientation treatment. Specific examples of chemical orientation treatments include orthographic deposition and photo-alignment treatment. Any appropriate condition may be adopted for the treatment conditions of various orientation treatments depending on the purpose. Orientation of the liquid crystal compound is performed by treating at a temperature that exhibits a liquid crystal phase, depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compound takes on a liquid crystal state, and the liquid crystal compound is oriented according to the orientation treatment direction of the substrate surface. In one embodiment, fixation of the orientation state is performed by cooling the liquid crystal compound oriented as described above. If the liquid crystal compound is a polymerizable monomer or a crosslinkable monomer, fixation of the orientation state is performed by performing a polymerization treatment or a crosslinking treatment on the liquid crystal compound oriented as described above. In this way, a first phase difference layer (21) is formed on the first substrate (61).

[0079] Meanwhile, as shown in FIG. 2(b), a second phase difference layer (22) is formed on the second substrate (62). Any suitable resin film may be used as the second substrate. Specific examples are as described above in relation to the first substrate. The second substrate is preferably a PET film. The second phase difference layer is formed, for example, using the liquid crystal compound and formation method described in

[0020] to

[0028] of Japanese Patent Publication No. 2002-333642 as described above. In this way, the second phase difference layer (22) is formed on the second substrate (62).

[0080] Next, as shown in (c) of FIG. 2, the first phase difference layer (21) and the second phase difference layer (22) in each of the laminates obtained above are bonded together with an active energy beam curable adhesive to form an intermediate laminate. The active energy beam curable adhesive is as described in Clause D above. More specifically, for example, the active energy beam curable adhesive is applied to the surface of the second phase difference layer, and the first phase difference layer is brought into contact with the surface (typically bonded) to form a precursor of the intermediate laminate, and if necessary, heated to irradiate a predetermined amount of active energy beams (e.g., ultraviolet rays) to cure the adhesive, thereby forming the intermediate laminate. Here, the curing shrinkage rate of the active energy beam curable adhesive is typically 5% or more as described above. If the curing shrinkage rate is within this range, when the intermediate laminate is formed, the Re (550) of the first phase difference layer can be increased by at least 0.5 nm, more preferably by at least 1.0 nm, even more preferably by at least 1.5 nm, particularly preferably by at least 2.5 nm, and very preferably by at least 3.0 nm due to the said shrinkage. As a result, the front reflection color values ​​a and b of the image display device at the beginning (before being placed under a high-temperature environment) are L * a * b * In the color space chromaticity diagram, in the direction of change under high-temperature environments, in advance It can be shifted. Therefore, the change in reflective color Δa under high-temperature environments (e.g., after durability testing) * b * The shrinkage rate can be reduced. However, if the annealing treatment described below is performed, the effect according to the embodiment of the present invention may be obtained even if the curing shrinkage rate is less than 5%.

[0081] 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, even more preferably 95°C or higher, and particularly preferably 100°C or higher. The upper limit of the annealing temperature may be, for example, 120°C. The processing time may vary depending on the processing temperature. The processing time is preferably 1 minute or more, more preferably 3 minutes or more, even more preferably 7 minutes or more, and particularly preferably 10 minutes or more. The upper limit of the processing time may be, for example, 20 minutes. By performing the annealing treatment, the Re (550) of the first phase difference layer can be increased preferably by 0.5 nm or more, more preferably by 1.0 nm or more, even more preferably by 1.5 nm or more, particularly preferably by 2.5 nm or more, and very preferably by 3.0 nm or more. As a result, the front reflection color values ​​a and b of the image display device at the beginning (before being placed under a high-temperature environment) are L * a * b * In the color space chromaticity diagram, in the direction of change under high-temperature environments, in advance It can be shifted. Therefore, the change in reflective color Δa under high-temperature environments (e.g., after durability testing) * b * The amount can be reduced. However, in cases where the curing shrinkage rate of the active energy beam curing adhesive is 5% or more as described above, the effect according to the embodiment of the present invention may be obtained without performing annealing treatment.

[0082] Preferably, an intermediate laminate can be formed using an active energy beam curable adhesive having a curing shrinkage rate of 5% or more, and said intermediate laminate can be subjected to an annealing treatment. As a result, the Re (550) of the first phase difference layer can be further increased.

[0083] Next, as shown in FIG. 2e, the first substrate (61) is peeled off from the intermediate laminate, and the first adhesive layer (40) is placed on the peeled surface (surface of the first phase difference layer (21)) to laminate a polarizing plate with the first adhesive layer (40) interposed therein. Furthermore, since the polarizing plate can be manufactured 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 placed on the peeled surface (surface of the second phase difference layer (22)). For example, the second adhesive layer is formed on a release film (not shown), and the laminate of the second adhesive layer and the release film is arranged so that the second adhesive layer contacts the surface of the second phase difference layer. In this way, a polarizing plate with a phase difference layer attached can be manufactured. When using a polarizer with a phase difference layer attached, the release film is removed.

[0084] G. Image display device

[0085] The polarizing plate with a phase difference layer attached as described in claims A through F above may be applied to an image display device. Accordingly, an embodiment of the present invention includes an image device utilizing such a polarizing plate with a phase difference layer attached. An image display device according to an embodiment of the present invention typically comprises a polarizing plate with a phase difference layer attached as described in claims A through F above on its viewing side. The polarizing plate with a phase difference layer attached is laminated so that the phase difference layer becomes the image display panel side (so that the polarizing plate becomes the viewing side). Examples of 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 (e.g., an organic EL display device) may have a curved shape (substantially, a curved display screen) and / or be bent or folded.

[0086] [Example]

[0087] The present invention will be specifically described below by way of examples, but the present invention is not limited by these examples. The measurement method for each characteristic is as follows. In addition, unless specifically stated otherwise, 'parts' and '%' in the examples and comparative examples are based on weight.

[0088] (1) Curing shrinkage rate

[0089] For the UV-curing adhesives used in the examples and comparative examples, the curing shrinkage rate was measured using the resin curing shrinkage rate stress measuring device 'EU201' manufactured by Sentec.

[0090] (2) Phase difference increase value

[0091] For the first phase difference layer (before fabrication of the intermediate laminate) and the intermediate laminate (after annealing treatment in the case of annealing treatment) fabricated 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. 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 fabrication of the intermediate laminate was defined as the 'phase difference rise value'. Furthermore, the in-plane phase difference of the intermediate laminate is substantially the in-plane phase difference of the first phase difference layer within the laminate.

[0092] (3) Δa * b *

[0093] The polarizers with phase difference layers obtained in the examples and comparative examples were laminated onto an alkali-free glass plate and used as test samples. These 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 plate, and the a and b values ​​were measured using a spectrophotometer / colorimeter 'CM-26d' manufactured by Konica Minolta, and the difference therefrom was Δa * b * ...did so.

[0094] [Preparation Examples 1-4: Preparation of UV-curing adhesives A-D]

[0095] UV-curing adhesives A to D were prepared by mixing each component shown in Table 1 in the proportions shown in Table 1. The curing shrinkage rates of UV-curing adhesives A to D were as shown in Table 1. In addition, the meaning of each term shown in Table 1 is as follows.

[0096] ACMO: Acryloylmorpholine manufactured by KJ Chemicals

[0097] Fluxel FA1DDM: Unsaturated fatty acid hydroxyalkyl ester formula ε-caprolactone manufactured by Daicel

[0098] ISTA: Isostearyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.

[0099] Light Acrylate LA: Lauryl acrylate manufactured by Kyoeisha Chemical Co., Ltd.

[0100] Light Acrylate 14EG-A: Polyethylene glycol diacrylate manufactured by Kyoei Chemical Co., Ltd.

[0101] Light Acrylate TMP-A: Trimethylpropane triacrylate manufactured by Kyoeisha Chemical Co., Ltd.

[0102] Alonix M-930: Glycerin triacrylate manufactured by Doa Gosei Co., Ltd.

[0103] KBM-403: 3-glycidoxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.

[0104] EX-146: p-tert-butylphenylglycidyl ether manufactured by Nagase Chemtex Co., Ltd.

[0105] OXT-212: 3-ethyl-3-[(2-ethylhexyl)oxy]oxetane manufactured by Doa Gosei Co., Ltd.

[0106] OXT-221: 3-ethyl-3-{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane manufactured by Doa Gosei Co., Ltd.

[0107] ARUFON UP-1190: Manufactured by Doa Gosei

[0108] ARUFON UG-4010: Manufactured by Doa Gosei

[0109] Omnirad 819: Manufactured by IGM Resins

[0110] CPI-110P: Manufactured by San Apro

[0111] [Table 1]

[0112]

[0113] [Example 1]

[0114] 1. Fabrication of a Polarizer

[0115] As a thermoplastic resin substrate, an amorphous isophthal copolymer polyethylene terephthalate film (thickness: 100 μm) was used, which is elongated, has an absorption rate of 0.75%, and a Tg of approximately 75°C. Corona treatment was performed on one side of the resin substrate.

[0116] A PVA aqueous solution (coating solution) was prepared by adding 13 parts by weight of potassium iodide to 100 parts by weight of a PVA-based resin mixed in a 9:1 ratio of polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Gosei Chemical Industry Co., Ltd., trade name 'Kose Feimer Z410') and dissolving the mixture in water.

[0117] A laminate was produced by applying the above PVA aqueous solution to the corona-treated surface of a resin substrate and drying it at 60°C to form a PVA-based resin layer with a thickness of 13 μm.

[0118] The obtained laminate was uniaxially stretched at the free end 2.4 times in the longitudinal direction (long direction) between rolls of different circumferential speeds in an oven at 130°C (air-assisted stretching treatment).

[0119] Next, the laminate was immersed for 30 seconds 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) (insolubilization treatment).

[0120] Next, the film was immersed for 60 seconds 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 respect to 100 parts by weight of water), while adjusting the concentration so that the elemental transmittance (Ts) of the finally obtained polarizing film becomes a desired value (dyeing treatment).

[0121] Next, it was immersed for 30 seconds 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) (crosslinking treatment).

[0122] Afterwards, the laminate was immersed in an aqueous boric acid solution (boric acid concentration 4.0 wt%, potassium iodide 5.0 wt%) at a liquid temperature of 70°C, and uniaxial stretching was performed in the longitudinal direction (long direction) between rolls of different circumferential speeds such that the total stretching ratio was 5.5 times (underwater stretching treatment).

[0123] Afterwards, the laminate was immersed in a cleaning 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) (cleaning treatment).

[0124] Afterwards, while drying in an oven maintained at 90°C, it was brought into contact with a heating roller made of SUS maintained at a surface temperature of 75°C for about 2 seconds (drying shrinkage treatment). The shrinkage rate of the laminate in the width direction due to the drying shrinkage treatment was 5.2%.

[0125] In this way, a polarizer with a thickness of 5 μm was formed on a resin substrate.

[0126] 2. Fabrication of polarizers

[0127] An HC-COP film was laminated onto the polarizer surface of the resin substrate / polarizer laminate obtained above, with a UV-curing adhesive interposed therebetween. Specifically, the curing adhesive was applied to a thickness of 1.0 μm and laminated using a roller machine. Subsequently, UV light was irradiated from the HC-TAC film side to cure the adhesive. Additionally, 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 film was laminated with the COP film facing the polarizer side. Next, the resin substrate was peeled off, and a TAC film with a Re (550) of about 0 nm to 2 nm was laminated onto the peeled surface in the same manner as above. In this way, a polarizing plate was obtained.

[0128] 3. Fabrication of the liquid crystal alignment solidification layer constituting the phase difference layer

[0129] 3-1. First phase difference layer

[0130] 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), heated to 60°C and stirred to dissolve, and after dissolution was confirmed, returned to room temperature and added 3 parts of Yirgacure 907 (manufactured by BASF Japan Co., Ltd.), 0.2 parts of Megapack F-554 (manufactured by DIC Co., Ltd.), and 0.1 parts of p-methoxyphenol (MEHQ), and further stirred 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. Meanwhile, the polyimide solution for the alignment film was applied to a TAC substrate using a spin coating method, dried at 100°C for 10 minutes, and then fired at 200°C for 60 minutes to obtain a coating film. The obtained 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, ultraviolet light was irradiated for 30 seconds at an intensity of 30 mW / cm² using a high-pressure mercury lamp to obtain a liquid crystal alignment solidification layer (thickness 4 μm). The in-plane phase difference Re (550) of the liquid crystal alignment solidification layer was 130 nm. In addition, the Re (450) / Re (550) of the liquid crystal alignment solidification layer was 0.851, exhibiting inverse dispersion wavelength characteristics.

[0131]

[0132]

[0133] 3-2. Second phase difference layer

[0134] A liquid crystal coating solution was prepared by dissolving 20 parts by weight of a side-chain liquid crystal polymer represented by the following chemical formula (1) (where the numbers 65 and 35 in the formula represent the mole% of monomer units and are conveniently represented as block polymers: weight average molecular weight 5000), 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 Chiba Specialty Chemicals: trade name Yirgacure 907) in 200 parts by weight of cyclopentanone. In addition, the liquid crystal was oriented by applying the coating solution to a PET substrate that had undergone vertical alignment treatment using a bar coater, and then heating and drying at 80°C for 4 minutes. By irradiating the liquid crystal layer with ultraviolet light and curing the liquid crystal layer, a second phase difference layer (thickness 3 μm) exhibiting refractive index characteristics of nz > nx = ny was formed on the substrate.

[0135]

[0136] 4. Fabrication of a polarizer with a phase difference layer

[0137] An intermediate laminate was formed by laminating the first phase difference layer and the second phase difference layer from each of the laminates obtained in 3-1 and 3-2 above with UV adhesive A (thickness of 1 μm after curing) interposed therein. 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 of 5 μm) was placed on the surface of the first phase difference layer, and a polarizing plate was laminated with said acrylic adhesive interposed therein. At this time, the polarizing plate was laminated with the TAC film facing the first phase difference layer side. Next, the PET substrate was peeled off, and a laminate of acrylic adhesive (thickness of 26 μm) / release film was placed on the surface of the second phase difference layer. In this way, a polarizing plate with a phase difference layer attached was fabricated. The obtained polarizing plate with a phase difference layer attached was subjected to the evaluation of (3) above. The results are shown in Table 2.

[0138] [Examples 2–13 and Comparative Examples 1–3]

[0139] A polarizer with a phase difference layer attached 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 polarizer with a phase difference layer attached was subjected to evaluation in the same manner as in Example 1. The results are shown in Table 2. In addition, 'None' in the annealing treatment column of Table 2 indicates that annealing treatment was not performed.

[0140] [Table 2]

[0141]

[0142] [evaluation]

[0143] As is evident from Table 2, the polarizer with a phase difference layer attached according to the embodiment of the present invention has Δa compared to the comparative example. * b * go It can be seen that the phase difference layer attached polarizer of the embodiment of the present invention can realize an image display device in which changes in reflection color under high temperature environments are suppressed.

[0144] [Industrial Applicability]

[0145] The polarizing plate with a phase difference layer attached according to the present invention is suitably used as a circular polarizing plate for anti-reflection of an image display device. Explanation of the symbols

[0146] 10: Polarizer 11: Polarizer 12: Protection layer 13: Protection layer 21: First phase difference layer 22: Second phase difference layer 30: Adhesive layer 40: First adhesive layer 50: Second adhesive layer 100: Polarizer with phase difference layer attached

Claims

Claim 1 A polarizing plate comprising a polarizer and a protective layer on at least one side of the polarizer, a first phase difference layer disposed on the side opposite to the viewing side of the polarizing plate, and a second phase difference layer laminated with an adhesive layer interposed on the side opposite to the polarizing plate of the first phase difference layer, wherein the first phase difference layer is a phase difference layer other than a C-plate, the second phase difference layer is a C-plate, the adhesive layer is composed of an active energy beam curing adhesive, and the curing shrinkage rate of the adhesive is 5% or more. Claim 2 A polarizing plate comprising a polarizer and a protective layer on at least one side of the polarizer, a first phase difference layer disposed on the side opposite to the viewing side of the polarizing plate, and a second phase difference layer laminated with an adhesive layer interposed on the side opposite to the polarizing plate of the first phase difference layer, wherein the first phase difference layer is a phase difference layer other than a C plate, the second phase difference layer is a C plate, and the laminate of the first phase difference layer and the second phase difference layer is annealed. Claim 3 In claim 1 or 2, the first phase difference layer exhibits a refractive index characteristic of nx > ny ≥ nz, Re (550) is 100 nm to 200 nm, and also Re (450)<Re(550)의 관계를 만족하고,상기 제2 위상차층이 nz> A polarizer with a phase difference layer attached, exhibiting refractive index characteristics of nx=ny: (wherein Re(450) and Re(550) are, respectively, in-plane phase differences measured with light of wavelengths of 450 nm and 550 nm at 23°C). Claim 4 In paragraph 3, the first phase difference layer and the second phase difference layer are orientation solidification layers of a liquid crystal compound, forming a phase difference layer attached polarizer. Claim 5 A method for manufacturing a polarizing plate with a phase difference layer attached as described in claim 1, comprising forming the first phase difference layer on a first substrate, forming the second phase difference layer on a second substrate, and laminating the first phase difference layer of the laminate of the first substrate and the first phase difference layer and the second phase difference layer of the laminate of the second substrate and the second phase difference layer through an active energy beam curable adhesive to form an intermediate laminate, wherein the curing shrinkage rate of the active energy beam curable adhesive is 5% or more. Claim 6 A manufacturing method according to claim 5, comprising increasing the Re(550) of the first phase difference layer by 0.5 nm or more when forming the intermediate laminate. Claim 7 A method for manufacturing a polarizing plate with a phase difference layer attached as described in paragraph 2, comprising: forming the first phase difference layer on a first substrate; forming the second phase difference layer on a second substrate; laminating the first phase difference layer of a laminate of the first substrate and the first phase difference layer and the second phase difference layer of a laminate of the second substrate and the second phase difference layer through an active energy beam curable adhesive to form an intermediate laminate; and annealing the intermediate laminate. Claim 8 A manufacturing method according to claim 7, wherein the processing temperature of the annealing treatment is 80℃ or higher and the processing time is 1 minute or higher. Claim 9 A manufacturing method according to claim 7 or 8, comprising increasing the Re(550) of the first phase difference layer by 0.5 nm or more by the annealing treatment. Claim 10 An image display device having a polarizing plate with a phase difference layer attached as described in claim 1 or 2.

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