TW202248691A - Polarizing plate with retardation layer and production method therefor, and image display device using said polarizing plate with retardation layer - Google Patents

Abstract

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

Description

Polarizing plate with retardation layer, manufacturing method thereof, and image display device using the polarizing plate with retardation layer

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

In recent years, image display devices represented by liquid crystal display devices and electroluminescence (EL, Electroluminescence) display devices (such as organic EL display devices and inorganic EL display devices) are rapidly becoming popular. In image display devices, polarizers and retardation plates are typically used. In terms of practicability, a polarizing plate with a retardation layer that integrates a polarizing plate and a retardation film is widely used, but recently, the demand for thinner image display devices has become increasingly strong. The demand for thinning the polarizing plate of the differential layer also increases accordingly. As one of methods for reducing the thickness of a polarizing plate with a retardation layer, a polarizing plate with a retardation layer using a retardation layer that fixes a liquid crystal compound in an aligned state has been proposed. However, an image display device using such a polarizing plate with a retardation layer has the problem of a large change in reflection hue in a high-temperature environment. prior art literature patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2020-064274

[Problem to be solved by the invention]

The present invention was made to solve the aforementioned problems, and its main object is to provide a polarizing plate with a retardation layer for an image display device capable of suppressing changes in reflection hue in a high-temperature environment. [Technical means to solve the problem]

A polarizing plate with a retardation layer according to an embodiment of the present invention has: a polarizing plate including a polarizing element and a protective layer on at least one side of the polarizing element; the side opposite to the side; and a second retardation layer, which is pasted on the opposite side of the first retardation layer to the polarizing plate via an adhesive layer. The first retardation layer is a retardation layer other than the C plate, and the second retardation layer is a C plate. In one embodiment, the adhesive layer includes an active energy ray-curable adhesive, and the hardening shrinkage of the adhesive is 5% or more. In another embodiment, the laminate of the first retardation layer and the second retardation layer is annealed. In one embodiment, the above-mentioned first retardation layer 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 above-mentioned first 2. The retardation layer exhibits a refractive index characteristic of nz>nx=ny. Here, Re(450) and Re(550) are the in-plane retardation measured at 23° C. with light having a wavelength of 450 nm and 550 nm, respectively. In one embodiment, the first retardation layer and the second retardation layer are alignment solidified layers of liquid crystal compounds. According to another aspect of the present invention, a method for manufacturing the above-mentioned polarizing plate with a retardation layer is provided. The manufacturing method includes: forming the above-mentioned first retardation layer on a first substrate; forming the above-mentioned second retardation layer on a second substrate; 1. The first retardation layer of the laminate of retardation layers and the second substrate and the second retardation layer of the laminate of the second retardation layers are bonded 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 layer by 0.5 nm or more when forming the intermediate laminate. In another embodiment, the above 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 above-mentioned annealing treatment has a treatment temperature of 80° C. or higher, and a treatment time of 1 minute or longer. According to still another aspect of the present invention, an image display device is provided. The image display device includes the above-mentioned polarizing plate with a retardation layer. [Effect of Invention]

According to the embodiments of the present invention, it is possible to obtain a polarizing plate with a retardation layer for an image display device capable of suppressing changes in reflection hue in a high-temperature environment.

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

(Definition of terms and symbols) The definitions of terms and symbols in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction where the in-plane refractive index reaches the maximum (ie, the slow axis direction), and "ny" is the refractive index in the in-plane direction perpendicular to the slow axis (ie, the slow axis direction), "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 at 23°C with light of wavelength 550 nm. Re(λ) is obtained by the formula: Re(λ)=(nx-ny)×d when the thickness of the layer (film) is d (nm). (3) Phase difference in thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured at 23°C with light of wavelength λ nm. For example, "Rth(550)" is the retardation in the thickness direction measured at 23°C with light of wavelength 550 nm. Rth(λ) is obtained by the formula: Rth(λ)=(nx-nz)×d when the thickness of the layer (film) is d (nm). (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 the clockwise direction and the counterclockwise direction with respect to the reference direction. So, for example, "45˚" means ±45˚.

A. Overall composition of polarizing plate with retardation layer FIG. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to an embodiment of the present invention. The polarizing plate 100 with a retardation layer shown in the illustration 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 polarizer 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 arranged on both sides of the polarizing element 11, but one of the viewing side protective layer 12 and the inner protective layer 13 can also be changed according to the purpose. omitted. The first retardation layer 21 is typically bonded to the opposite side of the polarizing plate 10 from the viewing side via the first adhesive layer 40 . The second retardation layer 22 is bonded to the opposite side of the first retardation layer 21 to the polarizing plate 10 through the adhesive layer 30 .

In the embodiment of the present invention, the first retardation layer 21 is a retardation layer other than the C plate, and the second retardation layer 22 is a C plate. The first retardation layer 21 typically exhibits a refractive index characteristic of nx>ny≧nz. That is, the first retardation layer may be a positive A plate (nx>ny=nz) or a negative B plate (nx>ny>nz). Furthermore, 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 a refractive index characteristic of nz>nx=ny. That is, the second retardation layer may be a positive C plate. When 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.

The first retardation layer and the second retardation layer are typically alignment-cured layers of liquid crystal compounds (hereinafter sometimes simply referred to as liquid-crystal alignment-cured layers). By using a liquid crystal compound, the difference between nx and ny of the obtained retardation layer can be significantly increased compared with non-liquid crystal materials, so the first retardation used to obtain the required in-plane retardation can be significantly reduced layer thickness. 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 achieved. In this specification, "alignment-cured layer" refers to a layer in which the liquid crystal compound is aligned in a specific direction within the layer, and its alignment state is fixed. Furthermore, the term "alignment hardened layer" includes the concept of an alignment hardened layer obtained by hardening liquid crystal monomers. The first retardation layer is typically aligned with the rod-shaped liquid crystal compound in the direction of the slow axis of the retardation layer (horizontal alignment); the second retardation layer is typically rod-shaped liquid crystal compound perpendicular to the film surface Alignment (vertical alignment).

In an embodiment of the present invention, the adhesive layer 30 includes an active energy ray-curable adhesive. The hardening shrinkage of the adhesive is typically 5% or more. Furthermore/or, the laminate of the first retardation layer and the second retardation layer is typically subjected to an annealing treatment. With such a configuration, compared with the case where the curing shrinkage rate of the adhesive is small, and/or the case where the laminated body of the first retardation layer and the second retardation layer is not annealed, the first retardation layer can be made The Re(550) of the laminate of the retardation layer and the second retardation layer (substantially the first retardation layer) increases. As a result, the front reflection hue a value and b value of the image display device at the initial stage (before it is placed in a high temperature environment) can be shifted in advance in the direction of change in the high temperature environment in the L ^* a ^* b ^* color space chromaticity diagram . Therefore, the reflection hue change Δa ^* b ^* in a high-temperature environment (for example, after an endurance test) can be reduced. This effect is remarkable when the retardation layer is a liquid crystal alignment solidified layer. That is, the liquid crystal alignment solidified layer is easily affected by the dimensional shrinkage of the polarizing plate in a high-temperature environment, and tends to have a larger reflection hue change Δa ^* b ^* than the retardation layer of the resin film. Here, the size of the polarizing plate in a high-temperature environment can be reduced by shifting the direction in which the initial front reflection hue a-value and b-value change in a high-temperature environment as described above (by experiencing the effect of dimensional shrinkage in advance). The effect of shrinkage, as a result, can reduce the reflection hue change Δa ^* b ^* .

In terms of practicality, a second adhesive layer is provided on the opposite side of the second retardation layer 22 to the polarizing plate 10 (that is, as the outermost layer on the opposite side to the viewing side), so that the polarizing plate with the retardation layer Can be attached to image display panels. Furthermore, preferably, 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 ready for use. By temporarily attaching the release film, the second adhesive layer 50 can be protected, and a polarizing plate with a retardation layer can be formed by rolling.

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

The polarizing plate with retardation layer may further include other optical function layers. The type, characteristics, quantity, combination, arrangement position, etc. of the optical function layers that can be provided in the polarizing plate with a retardation layer can be appropriately set according to the purpose. For example, the polarizing plate with a retardation layer may further have a conductive layer or an isotropic substrate with a conductive layer (both not shown). The conductive layer or the isotropic substrate with the conductive layer is typically provided outside the second retardation layer 22 (opposite to the polarizing plate 10 ). In the case where a conductive layer or an isotropic substrate with a conductive layer is provided, the polarizing plate with a retardation layer is assembled with a touch sensor between the image display panel and the polarizing plate, and can be applied to the so-called Internal touch panel type input display device. For another example, the polarizing plate with a retardation layer may further include another retardation layer. The optical characteristics (such as refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, etc. of other retardation layers can be appropriately set according to the purpose.

The polarizing plate with a retardation layer can be in the shape of a single sheet or in a strip shape. In this specification, "elongate shape" means a long and thin shape with a relatively long length relative to the width, including, for example, a long and thin shape whose length is 10 times or more, preferably 20 times or more, relative to the width. The elongated polarizing plate with a retardation layer can be wound into a roll.

Hereinafter, the constituent elements of the polarizing plate with a retardation layer will be described in more detail.

B. Polarizer B-1. Polarizing element As the polarizing element 11, any appropriate polarizing element can be used. For example, the resin film forming the polarizing element may be a single-layer resin film, or may be a laminate of two or more layers.

Specific examples of polarizing elements including a single-layer resin film include polyvinyl alcohol (PVA, Polyvinyl Alcohol)-based films, partially formalized PVA-based films, ethylene-vinyl acetate copolymer-based partially saponified films, and the like. Permanent polymer film, which is dyed and stretched with dichroic substances such as iodine or dichroic dyes, and polyene-based alignment films such as dehydrated PVA or dehydrochlorinated polyvinyl chloride. In terms of excellent optical properties, it is preferable to use a polarizing element obtained by dyeing a PVA-based film with iodine and uniaxially stretching it.

The above-mentioned dyeing with iodine is performed, for example, by immersing a PVA-type film in an iodine aqueous solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching can be performed after dyeing, or stretching can be performed while dyeing. In addition, dyeing may be performed after stretching. Swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc. are performed on the PVA-based film as necessary. For example, washing the PVA film by immersing it in water before dyeing can not only clean the dirt and anti-blocking agent on the surface of the PVA film, but also swell the PVA film to prevent uneven dyeing.

Specific examples of a polarizing element obtained by using a laminate include a laminate using a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material formed by coating. A polarizing element obtained by a laminate of PVA-based resin layers on the resin substrate. A polarizing element obtained by using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying it. A PVA-based resin layer is formed on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; the laminate is stretched and dyed to make the PVA-based resin layer into a polarizing element. In this embodiment, stretching typically includes immersing the laminate in an aqueous solution of boric acid and stretching it. Furthermore, stretching may further include stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in an aqueous solution of boric acid, if necessary. The obtained resin substrate/polarizer laminate can be used directly (i.e., the resin substrate can also be used as a protective layer for the polarizer), or the resin substrate can be peeled off from the resin substrate/polarizer laminate. This release surface layer can be used as any suitable protective layer according to the purpose. Details of the manufacturing method of such a polarizing element are described in, for example, Japanese Patent Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The entire descriptions of these publications are incorporated herein by reference.

The thickness of the polarizing element is preferably at most 15 μm, more preferably at most 12 μm, still more preferably at most 10 μm, particularly preferably at most 8 μm. On the other hand, the thickness of the polarizing element is preferably at least 1 μm, more preferably at least 2 μm, and still more preferably at least 3 μm. When the thickness of the polarizing element is within such a range, curling during heating can be favorably suppressed, and favorable appearance durability during heating can be obtained.

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

B-2. Protective layer The viewing-side protective layer 12 and the inner protective layer 13 each include any appropriate film that can be used as a protective layer of a polarizing element. Specific examples of the material of the main component of the film include cellulose-based resins such as triacetyl cellulose (TAC, Triacetyl Cellulose), polyester-based, polyvinyl alcohol-based, polycarbonate-based, and polyamide-based resins. Polyimide-based, polyether-based, polystyrene-based, polystyrene-based, cyclic olefin-based (such as polynorthene-based), polyolefin-based, (meth)acrylic-based, acetate-based and other transparent resins. Further, thermosetting resins such as (meth)acrylic, polyurethane, (meth)acrylic polyurethane, epoxy, and silicone, or ultraviolet curable resins can also be exemplified. In addition, glassy polymers, such as a siloxane polymer, are mentioned, for example. Moreover, the polymer film described in Unexamined-Japanese-Patent No. 2001-343529 (WO01/37007) can also be used. As the material of the film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imino group in the side chain, and a thermoplastic resin having a substituted or unsubstituted phenyl and nitrile group in the side chain can be used, for example. For example, the resin composition which has the alternating copolymer containing isobutylene and N-methylmaleimide, and an acrylonitrile-styrene copolymer is mentioned, for example. The polymer film may be, for example, an extruded product of the aforementioned resin composition.

The polarizing plate with a retardation layer is typically arranged on the viewing side of the image display device as described below, and the viewing side protective layer 12 is arranged on the viewing side. Therefore, surface treatments such as hard coating treatment, anti-reflection treatment, anti-blocking treatment, and anti-glare treatment can also be performed on the viewing-side protective layer 12 as required. Furthermore or alternatively, the viewing-side protective layer 12 may also be treated to improve the visibility of the situation of recognition through polarized sunglasses (typically, imparting (elliptical) polarized light function, imparting ultra-high retardation) to the viewing-side protective layer 12 as needed. By performing such processing, excellent visibility can be realized even when a display screen is viewed through a polarized lens such as polarized sunglasses. Therefore, the polarizing plate with a retardation layer can also be suitably applied to image display devices that can be used outdoors. Furthermore, as a material constituting the viewing-side protective layer, preferably, cyclic olefin-based resins (such as polynorthene-based resins) and cellulose-based resins (such as TAC) can be mentioned.

The thickness of the viewing-side protective layer 12 is preferably 5 μm-80 μm, more preferably 10 μm-40 μm, further preferably 10 μm-30 μm. Furthermore, in the case of surface treatment, the thickness of the protective layer on the viewing side includes the thickness of the surface treatment layer.

In one embodiment, the inner protective layer 13 is preferably optically isotropic. "Optical isotropy" in this specification means that the in-plane retardation Re(550) is 0 nm to 10 nm, and the retardation Rth(550) in the thickness direction is -10 nm to +10 nm. The thickness of the inner protective layer 13 is preferably from 5 μm to 80 μm, more preferably from 10 μm to 40 μm, and still more preferably from 10 μm to 30 μm. As a material constituting the inner protective layer, cyclic olefin-based (eg, polynorthene-based), cellulose-based resins (eg, TAC), and acrylic-based resins may, for example, be preferred.

C. Retardation layer C-1. The first retardation layer Typically, the first retardation layer 21 can function as a λ/4 plate. The first retardation layer is typically provided for imparting antireflection properties to an image display device. Typically, the first retardation layer exhibits a refractive index characteristic 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, further preferably 120 nm to 160 nm. Furthermore, "ny=nz" here includes not only the situation where ny and nz are completely equal, but also the situation where they are substantially equal. Therefore, ny>nz or ny<nz may exist in the range which does not impair the effect of this invention.

The Nz coefficient of the retardation layer is preferably from 0.9 to 1.5, more preferably from 0.9 to 1.3. By satisfying this relationship, an image display device having a very excellent reflection hue can be obtained.

The first retardation layer preferably exhibits inverse wavelength dispersion characteristics in which the retardation value increases according to the wavelength of the measurement light. That is, the first retardation layer preferably satisfies the relationship 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 from 1.0 to less than 1.15, more preferably from 1.03 to 1.1. With such a configuration, very excellent antireflection characteristics can be realized.

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

Typically, the first retardation layer may be a liquid crystal alignment solidified layer as described above. As described above, by using liquid crystal compounds, the difference between nx and ny of the obtained retardation layer can be significantly increased compared with non-liquid crystal materials, so the time required to obtain the desired in-plane retardation can be significantly reduced. The thickness of the first retardation layer. The first retardation layer is typically aligned (horizontal alignment) in a state where the rod-shaped liquid crystal compound is aligned in the slow axis direction of the retardation layer as described above.

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

When the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a crosslinkable monomer. Because by polymerizing or crosslinking (ie, hardening) the liquid crystal monomer, the alignment state of the liquid crystal monomer can be fixed. After aligning the liquid crystal monomers, for example, by polymerizing or cross-linking the liquid crystal monomers, the above alignment state can be fixed. Here, although a polymer is formed by polymerization and a three-dimensional network structure is formed by crosslinking, these are non-liquid crystalline. Therefore, the formed first retardation layer does not undergo transition to a liquid crystal phase, a glass phase, or a crystalline phase, for example, due to temperature changes peculiar to liquid crystal compounds. As a result, the first retardation layer becomes a retardation layer extremely excellent in stability without being affected by temperature changes.

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

Any appropriate liquid crystal monomer can be used as the above-mentioned liquid crystal monomer. For example, polymerizable mesogen compounds described in Japanese Patent Application Laid-Open No. 2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171, and GB2280445 can be used.

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

C-2. The second retardation layer As described above, the second retardation layer 22 may be a positive C plate whose refractive index characteristic shows the relationship of nz>nx=ny. By using the positive C plate as the second retardation layer, reflection in oblique directions can be well prevented, and wide viewing angle of the antireflection function becomes possible. 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, and more preferably -90 nm to -200 nm, particularly preferably -100 nm to -180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. That is, the in-plane retardation Re(550) of the second retardation layer may be less than 10 nm.

The second retardation layer can be formed of any appropriate material. The second retardation layer preferably includes a film containing a liquid crystal material fixed in a homeotropic alignment. The vertically aligned liquid crystal material (liquid crystal compound) can 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 those described in [0020] to [0028] of JP-A-2002-333642 and the method for forming the retardation layer. In this case, the thickness of the second retardation layer is preferably from 0.5 μm to 10 μm, more preferably from 0.5 μm to 8 μm, and still more preferably from 0.5 μm to 5 μm.

D. Adhesive Layer As described above, the adhesive layer 30 contains an active energy ray-curable adhesive. The hardening shrinkage of the adhesive agent is typically at least 5% as described above, preferably at least 7%, more preferably at least 10%, and still more preferably at least 14%. The upper limit of the hardening shrinkage of the adhesive can be 20%, for example. With such a configuration, the 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 initial stage of the image display device ( Before being placed in a high temperature environment), the front reflection hue a value and b value in the L ^* a ^* b ^* color space chromaticity diagram are shifted in advance in the direction of the change in the high temperature environment. Therefore, the reflection hue change Δa ^* b ^* in a high-temperature environment (for example, after an endurance test) can be reduced. Furthermore, in the case of annealing the laminate of the first retardation layer and the second retardation layer, even when the cure shrinkage of the adhesive is less than the above range (for example, 3%), the above-mentioned The situation of the effect.

As the active energy ray-curable adhesive, any appropriate active energy ray-curable adhesive can be used as long as the curing shrinkage rate is within the above-mentioned range. As an active energy ray hardening type adhesive agent, an ultraviolet-ray hardening type adhesive agent and an electron beam hardening type adhesive agent are mentioned, for example. In addition, from the viewpoint of curing mechanism, examples of active energy ray curing adhesives include radical curing, cation curing, anion curing, and mixtures of radical curing and cation curing. Typically, a radical-curing UV-curable adhesive can be used. Because it has excellent versatility and its characteristics (composition) can be adjusted easily.

Active energy ray-curable adhesives typically contain a monofunctional component, a polyfunctional component (hardening component), and a photopolymerization initiator. Each of the monofunctional component and the polyfunctional component is typically a radically polymerizable compound. As a preferable monofunctional component, the higher alkyl ester of (meth)acrylic acid, and its modified body are mentioned, for example. Specific examples include isostearyl acrylate, lauryl acrylate, acryloyl methanoline, and ε-caprolactone modified with unsaturated fatty acid hydroxyalkyl ester. As a preferable polyfunctional component, the monomer and/or oligomer which have two or more functional groups, such as a (meth)acrylate group and a (meth)acrylamide group, are mentioned, for example. Specific examples include polyethylene glycol diacrylate, trimethylpropane triacrylate, and glycerin triacrylate. Specific examples of monofunctional 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 acrylate, EO modified diglycerol tetraacrylate, γ-butyrolactone acrylate, N-methylpyrrolidine Ketone, hydroxyethylacrylamide, N-methylolacrylamide, N-methoxymethacrylamide, N-ethoxymethacrylamide, 9-vinylcarbazole. In one embodiment, the monofunctional component or the polyfunctional component has a ring structure. Specific examples include acryloyl methanoline, γ-butyrolactone acrylate, unsaturated fatty acid hydroxyalkyl ester-modified ε-caprolactone, N-methylpyrrolidone, and 9-vinylcarbazole. A monofunctional component or a polyfunctional component may be used individually, respectively, and may use 2 or more types together.

The active energy ray-curable adhesive may further contain a cationically polymerizable compound if necessary. A cationically polymerizable compound may be monofunctional or polyfunctional. As a monofunctional cationic polymerizable compound, p-tert-butylphenyl glycidyl ether and 3-ethyl-3-[(2-ethylhexyl)oxy] oxetane are mentioned, for example. As a polyfunctional cationic polymerizable compound, 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane is mentioned, for example. A silane coupling agent can also be used as a cationic polymerizable compound. As a silane coupling agent, 3-glyceryloxypropyl trimethoxysilane is mentioned, for example.

The active energy ray-curable adhesive may further contain an acrylic oligomer if necessary. The molecular weight of an acrylic oligomer can be suitably set according to the objective.

The active energy ray-curable adhesive may further contain a plasticizer (such as an oligomer component), a crosslinking agent, a diluent, and the like depending on the purpose. By adjusting the types, combinations, and blending ratios of these components, as well as the above-mentioned monofunctional components, polyfunctional components, cationic polymerizable compounds, acrylic oligomers, and photopolymerization initiators, it is possible to obtain desired Active energy ray hardening adhesive with hardening shrinkage rate. In addition, the above-mentioned each component can also use a commercial item.

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

Details of active energy ray-curable adhesives are described in, for example, Japanese Patent Laid-Open No. 2018-017996. The description of this publication is incorporated in this specification as a reference.

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, a detailed description thereof will be omitted.

F. Manufacturing method of polarizing plate with retardation layer Embodiments of the present invention also include a method for manufacturing the above-mentioned polarizing plate with a retardation layer. The 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; The first retardation layer of the laminate of the difference layers is bonded to the second substrate and the second retardation layer of the laminate of the second retardation layers to form an intermediate laminate. Hereinafter, a representative example of the manufacturing method will be described with reference to FIG. 2 .

First, as shown in FIG. 2( a ), the first retardation layer 21 is formed on the first base material 61 . Arbitrary appropriate resin films can be mentioned as a 1st base material. As specific examples, cellulose-based resin films such as triacetyl cellulose (TAC) films, polyester-based films such as polyethylene terephthalate (PET, Polyethylene Terephthalate) films, acrylic resin films, etc. membrane. TAC film is preferred. The first retardation layer can typically be performed by performing an alignment treatment on the surface of the first substrate, coating the surface with a coating liquid containing a liquid crystal compound and aligning the liquid crystal compound in a direction corresponding to the alignment treatment described above, This alignment state is fixed and formed. As the alignment treatment, any appropriate alignment treatment can be employed. Specifically, mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment may 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 the chemical alignment treatment include oblique vapor deposition and photo-alignment treatment. The processing conditions of various alignment processing can adopt arbitrary appropriate conditions according to the purpose. Alignment of liquid crystal compounds is carried out by performing treatment at a temperature at which a liquid crystal phase is displayed according to the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compound acquires a liquid crystal state, and the liquid crystal compound is aligned according to the direction of the alignment treatment on the surface of the substrate. In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is a polymerizable monomer or a crosslinkable monomer, the alignment state is fixed by performing a polymerization treatment or a crosslinking treatment on the liquid crystal compound aligned as described above. In this way, the first retardation layer 21 is formed on the first base material 61 .

On the other hand, as shown in FIG. 2( b ), the second retardation layer 22 is formed on the second base material 62 . Arbitrary appropriate resin films can be mentioned as a 2nd base material. Specific examples are as described above for the first base material. The second base material is preferably a PET film. The second retardation layer is formed, for example, using the liquid crystal compound and the formation method described in [0020] to [0028] of JP-A-2002-333642 as described above. In this way, the second retardation layer 22 is formed on the second base material 62 .

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

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

It is preferable to form an intermediate laminate using an active energy ray-curable adhesive having a hardening shrinkage rate of 5% or more, and subject the intermediate laminate to annealing treatment. As a result, Re(550) of the first retardation layer can be further increased.

Next, as shown in FIG. 2( e ), the first substrate 61 is peeled and removed from the intermediate laminate, and the first adhesive layer 40 is disposed on the peeled surface (the surface of the first retardation layer 21 ), and the first adhesive layer 40 is disposed through the first adhesive layer. 40 fit polarizer. Furthermore, since the polarizing plate can be produced by any appropriate method, the detailed description of the production method of the polarizing plate is omitted. Practically, as shown in FIG. 2( f ), the second base material 62 is peeled off, and the second adhesive layer 50 is arranged 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 the laminate of the second adhesive layer and the release film is arranged 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 manufactured. Remove the release film when using the polarizing plate with retardation layer.

G. Image display device The polarizing plate with a retardation layer described in the above items A to F can be applied to an image display device. Therefore, an embodiment of the present invention includes an image device using such a polarizing plate with a retardation layer. The image display device according to the embodiment of the present invention typically includes the polarizing plate with a retardation layer described in the above items A to F on the viewing side. The polarizing plate with a retardation layer is laminated so that the retardation layer is on the image display panel side (the polarizing plate is on the viewing side). Typical examples of image display devices include liquid crystal display devices, organic electroluminescence (EL) display devices, and inorganic EL display devices. In one embodiment, an image display device (such as an organic EL display device) has a curved shape (substantially a curved display screen), and/or can be bent or bent. Example

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. Furthermore, unless otherwise specified, the "parts" and "%" in the examples and comparative examples are based on weight.

(1) Curing shrinkage The curing shrinkage of the ultraviolet curable adhesives used in Examples and Comparative Examples was measured using a resin curing shrinkage stress measuring device "EU201" manufactured by Sentech Corporation. (2) Retardation increase value Regarding the first retardation layer (before the production of the intermediate laminate) and the intermediate laminate (after annealing in the case of annealing) produced in the examples and comparative examples, Axometrics The phase difference measurement device (product name "Axo Scan") manufactured by the company was used to measure the in-plane phase difference. The measurement wavelength of the in-plane retardation is 550 nm, and the measurement temperature is 23°C. The difference between the in-plane retardation of the intermediate laminate and the in-plane retardation of the first retardation layer before the preparation of the intermediate laminate was defined as the "retardation increase value". Furthermore, the in-plane retardation of the intermediate laminate is substantially the in-plane retardation of the first retardation layer in the laminate. (3) Δa ^* b ^* The polarizing plates with retardation layers obtained in Examples and Comparative Examples were bonded to non-alkali glass plates to prepare test samples. This test sample was subjected to a durability test at 80° C. for 500 hours. The test samples before and after the durability test were placed on the mirror plate, and the a value and the b value were measured using a spectrophotometer and color difference meter "CM-26d" manufactured by Konica Minolta Co., Ltd., and the difference was defined as Δa ^* b ^* .

[Manufacturing Examples 1-4: Preparation of UV Curable Adhesives A-D] The ingredients shown in Table 1 were mixed in the ratio shown in Table 1 to prepare UV-curable adhesives A to D. Table 1 shows the cure shrinkage ratios of UV-curable adhesives A to D. In addition, the meaning of each term shown in Table 1 is as follows. ACMO: Acryloyl methionine manufactured by KJ Chemicals PLACCEL FA1DDM: ε-caprolactone modified with unsaturated fatty acid hydroxyalkyl ester manufactured by Daicel 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: Trimethylpropane triacrylate manufactured by Kyoeisha Chemical Co., Ltd. ARONIX M-930: Glycerin triacrylate manufactured by Toagosei Co., Ltd. KBM-403: 3-Glyceryloxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. EX-146: p-tert-butylphenyl glycidyl ether manufactured by Nagase ChemteX Co., Ltd. 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 Toa Gosei Co., Ltd. Omnirad 819: Made by IGMresins CPI-110P: Manufactured by San-Apro

[Table 1] The content ratio of each component in the adhesive [% by weight] Adhesive A Adhesive B Adhesive C Adhesive D free radical polymerizable compound monofunctional ACMO 19.5 9.8 PLACCEL FA1DDM 12.7 19.6 ISTA 24.5 19.2 Light Acrylate LA 19.6 19.2 multifunctional Light Acrylate 14EG-A 9.8 9.6 Light Acrylate TMP-A 29.2 ARONIX M-930 29.2 cationic polymerizable compound Silane coupling agent KBM-403 2.0 1.0 0.9 monofunctional EX-146 13.5 36.8 OXT-212 19.2 28.3 multifunctional OXT-221 18.9 Acrylic oligomer ARUFON UP-1190 4.9 ARUFON UG-4010 14.7 14.5 9.4 Free Radical Polymerization Initiator Omnirad 819 2.0 2.0 1.9 1.9 photoacid generator CPI-110P 0.5 1.9 3.8 Hardening shrinkage % 15 7 5 3

[Example 1] 1. Fabrication of polarizing elements As the thermoplastic resin substrate, a long amorphous isophthalene copolymerized polyethylene terephthalate film (thickness: 100 μm) with a water absorption rate of 0.75% and a Tg of about 75° C. was used. Corona treatment is performed on one side of the resin substrate. Polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mole%) and acetoacetyl modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z410") at a ratio of 9: 1 mixed PVA-based resin 100 13 parts by weight of potassium iodide was added to parts by weight, and this was dissolved in water to prepare an aqueous PVA solution (coating solution). The above-mentioned 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 free end of the obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) between rollers having different circumferential speeds in an oven at 130° C. (in-air assisted stretching treatment). Next, the laminated body was immersed for 30 seconds in an insolubilization bath (an aqueous solution of boric acid prepared by mixing 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40° C. (insolubilization treatment). Then, in a dyeing bath (with respect to 100 parts by weight of water, an iodine aqueous solution obtained by preparing iodine and potassium iodide at a weight ratio of 1:7) at a liquid temperature of 30° C., the concentration was adjusted so that the polarizing film finally obtained When the monomer transmittance (Ts) reaches the desired value, one side is dipped for 60 seconds (dyeing treatment). Then, it was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40° C. for 30 seconds (crosslinking treatment). Thereafter, the laminated body was immersed in a boric acid aqueous solution (boric acid concentration: 4.0% by weight, potassium iodide: 5.0% by weight) at a liquid temperature of 70°C, while being uniaxially stretched in the longitudinal direction (longitudinal direction) between rollers with different peripheral speeds to obtain Make the total elongation ratio reach 5.5 times (extension treatment in water). Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 20° C. (washing treatment). Thereafter, while drying in an oven maintained at 90° C., it was brought into contact with a SUS heating roller whose surface temperature was maintained at 75° C. for about 2 seconds (drying shrinkage treatment). The shrinkage rate in the width direction of the laminate subjected to drying shrinkage treatment was 5.2%. In this way, a polarizing element with a thickness of 5 μm was formed on the resin substrate.

2. Production of polarizing plate The HC-COP film was pasted on the surface of the polarizer of the resin substrate/polarizer laminate obtained above through an ultraviolet curable adhesive. Specifically, it is applied so that the thickness of the hardening adhesive becomes 1.0 μm, and it is bonded using a roller press machine. Thereafter, UV (Ultraviolet) rays were irradiated from the HC-TAC film side to harden the adhesive. Furthermore, the HC-COP film is a film formed by forming a hard coat (HC) layer (thickness 2 μm) on a cyclic olefin resin (COP) film (thickness 25 μm), and is attached so that the COP film is on the side of the polarizer . Next, the resin substrate was peeled off, and a TAC film having an Re(550) of about 0 nm to 2 nm was attached to the peeled surface in the same manner as above. In this way, a polarizing plate was obtained.

3. Fabrication of the liquid crystal alignment solidified layer constituting the retardation layer 3-1. The first retardation layer Add 55 parts of the compound represented by formula (I) and 55 parts of the compound represented by formula (II) to 400 parts of cyclopentanone (CPN) After 25 parts of the compound and 20 parts of the compound represented by formula (III), heat, stir and dissolve at 60°C. After confirming the dissolution, return to room temperature and add Irgacure 907 (manufactured by BASF Japan Co., Ltd.) 3 parts, 0.2 parts of MEGAFAC F-554 (manufactured by DIC Co., Ltd.), and 0.1 part of p-methoxyphenol (MEHQ) were further stirred to obtain a solution. The solution is transparent and homogeneous. The obtained solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. On the other hand, the polyimide solution for the alignment film was coated on the 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 is subjected to rubbing treatment to form an alignment film. The rubbing treatment was performed using a commercially available rubbing device. The polymerizable composition obtained above was coated on the surface of the alignment film by spin coating method, and dried at 100° C. for 2 minutes. After the obtained coating film was cooled to room temperature, a high-pressure mercury lamp was used to irradiate ultraviolet light at an intensity of 30 mW/cm ² for 30 seconds to obtain a liquid crystal alignment solidified layer (thickness 4 μm). The in-plane retardation Re(550) of the liquid crystal alignment solidified layer was 130 nm. Also, Re(450)/Re(550) of the liquid crystal alignment solidified layer was 0.851, showing reverse wavelength dispersion characteristics.

[化2]

[chemical 1]

[Chem 2]

3-2. The second retardation layer is represented by the following chemical formula (1) (numbers 65 and 35 in the formula represent the mole % of the monomer unit, conveniently represented by a block polymer body: weight average molecular weight 5000) 20 parts by weight of a side-chain liquid crystal polymer, 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name PaliocolorLC 242), and a photopolymerization initiator (manufactured by Ciba Specialty Chemicals: trade name Irgacure 907) ) 5 parts by weight were dissolved in 200 parts by weight of cyclopentanone to prepare a liquid crystal coating solution. Then, the coating liquid was coated on the PET substrate subjected to the vertical alignment treatment by a bar coater, and then heated and dried at 80° C. for 4 minutes to align the liquid crystals. By irradiating the liquid crystal layer with ultraviolet rays, the liquid crystal layer was cured, and a second retardation layer (thickness 3 μm) exhibiting a refractive index characteristic of nz>nx=ny was formed on the substrate. [Chem 3]

4. Production of polarizing plate with retardation layer The first retardation layer and the second retardation layer in each of the laminates obtained in the above 3-1. and 3-2. were bonded via UV adhesive A (thickness after curing: 1 μm), and An intermediate laminate is formed. This intermediate laminate was subjected to annealing treatment at 100° C. for 10 minutes. The TAC substrate was peeled off from the annealed intermediate laminate, an acrylic adhesive (5 μm in thickness) was placed on the surface of the first retardation layer, and a polarizing plate was bonded through the acrylic adhesive. At this time, the polarizing plate was bonded so that the TAC film was located on the first retardation layer side. Next, the PET substrate was peeled off, and a laminate of acrylic adhesive (thickness 26 μm)/release film was placed on the surface of the second retardation layer. In this way, a polarizing plate with a retardation layer was produced. The obtained polarizing plate with a retardation layer was used for the evaluation in (3) above. The results are shown in Table 2.

[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 annealing treatment in Table 2 indicates that no annealing treatment was performed.

[Table 2] Adhesive Hardening shrinkage Annealing Phase difference rise value (nm) ∆a*b* Example 1 UV adhesive A 15% 100°C for 10 minutes 3.7 0.1 Example 2 ↑ 15% 80°C for 5 minutes 3.2 0.3 Example 3 ↑ 15% 80°C for 1 minute 2.7 0.4 Example 4 ↑ 15% none 1.6 1.2 Example 5 UV adhesive B 7% 100°C for 10 minutes 3.1 0.4 Example 6 ↑ 7% 80°C for 5 minutes 2.6 0.7 Example 7 ↑ 7% 80°C for 1 minute 2 0.9 Example 8 ↑ 7% none 1 1.2 Example 9 UV adhesive C 5% 100°C for 10 minutes 2.5 0.7 Example 10 ↑ 5% 80°C for 5 minutes 1.9 0.9 Example 11 ↑ 5% 80°C for 1 minute 1 1.1 Example 12 ↑ 5% none 0.6 1.4 Example 13 UV adhesive D 3% 100°C for 10 minutes 1.2 1.3 Comparative example 1 ↑ 3% 80°C for 5 minutes 0.4 2.1 Comparative example 2 ↑ 3% 80°C for 1 minute 0.3 2.2 Comparative example 3 ↑ 3% none 0 3

[Evaluation] It can be seen from Table 2 that Δa ^* b ^* of the polarizing plate with a retardation layer in the embodiment of the present invention is smaller than that in the comparative example. That is, it can be seen that the polarizing plate with a retardation layer according to the example of the present invention can realize an image display device in which the change in reflection hue in a high-temperature environment is suppressed. [Industrial availability]

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

10: polarizer 11: Polarizing element 12: Protective layer 13: Protective layer 21: The first retardation layer 22: The second retardation layer 30: Adhesive layer 40: 1st adhesive layer 50: 2nd adhesive layer 61: 1st substrate 62: Second substrate 100: Polarizing plate with retardation layer

FIG. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to an embodiment of the present invention. 2( a ) to ( f ) are flow charts including schematic cross-sectional views illustrating manufacturing steps of a polarizing plate with a retardation layer according to an embodiment of the present invention.

10: polarizer

11: Polarizing element

12: Protective layer

13: Protective layer

21: The first retardation layer

22: The second retardation layer

30: Adhesive layer

40: 1st adhesive layer

50: 2nd adhesive layer

100: Polarizing plate with retardation layer

Claims (10)

A polarizing plate with a retardation layer, which has: A polarizing plate, which includes a polarizing element and a protective layer on at least one side of the polarizing element; a first retardation layer, which is arranged on the opposite side of the polarizing plate from the viewing side; and a second retardation layer, which is passed through the following The agent layer is pasted on the opposite side of the first retardation layer to the polarizing plate; and The first retardation layer is a retardation layer other than the C plate, the second retardation layer is a C plate, The adhesive layer includes an active energy ray-curable adhesive, and the hardening shrinkage of the adhesive is more than 5%. A polarizing plate with a retardation layer, which has: A polarizing plate, which includes a polarizing element and a protective layer on at least one side of the polarizing element; a first retardation layer, which is arranged on the opposite side of the polarizing plate from the viewing side; and a second retardation layer, which is passed through the following The agent layer is pasted on the opposite side of the first retardation layer to the polarizing plate; and The first retardation layer is a retardation layer other than the C plate, the second retardation layer is a C plate, The laminate of the first retardation layer and the second retardation layer is annealed. For the polarizing plate with a retardation layer of claim 1 or 2, Wherein the above-mentioned first retardation layer 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), and The above-mentioned second retardation layer exhibits a refractive index characteristic of nz>nx=ny, Here, Re(450) and Re(550) are the in-plane retardation measured at 23° C. with light having a wavelength of 450 nm and 550 nm, respectively. The polarizing plate with retardation layer according to claim 3, wherein the first retardation layer and the second retardation layer are alignment solidified layers of liquid crystal compounds. A manufacturing method, which is a manufacturing method of a polarizing plate with a retardation layer as claimed in claim 1, and includes: forming the above-mentioned first retardation layer on the first substrate; forming the above-mentioned second retardation layer on the second substrate; and The first retardation layer of the laminate of the first substrate and the first retardation layer and the laminate of the second substrate and the second retardation layer are Laminating the second retardation layer to form an intermediate laminate; The hardening shrinkage rate of the active energy ray hardening adhesive is 5% or more. The manufacturing method according to claim 5, which includes increasing Re(550) of the first retardation layer by 0.5 nm or more when forming the intermediate laminate. a manufacturing method, It is a method of manufacturing a polarizing plate with a retardation layer as claimed in claim 2, and includes: forming the above-mentioned first retardation layer on the first substrate; Forming the above-mentioned second retardation layer on the second substrate; The first retardation layer of the laminate of the first substrate and the first retardation layer and the laminate of the second substrate and the second retardation layer are bonding the second retardation layer to form an intermediate laminate; and An annealing treatment is performed on this intermediate laminate. The manufacturing method according to claim 7, wherein the annealing treatment temperature is above 80° C., and the treatment time is above 1 minute. The manufacturing method according to claim 7 or 8, which includes increasing the Re(550) of the first retardation layer by 0.5 nm or more by the annealing treatment. An image display device comprising the polarizing plate with a retardation layer according to any one of Claims 1 to 4.

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