TW202229013A - Phase difference layer-equipped phase difference layer-equipped polarizing plate and organic electroluminescence display device using same - Google Patents

Abstract

Provided is a phase difference layer-equipped polarizing plate in which decolorization is markedly suppressed when the polarizing plate is applied in an organic EL display device. A phase difference layer-equipped polarizing plate according to an embodiment of the present invention has a polarizer and a block layer which is positioned on one side of the polarizer and which includes a phase difference layer, the amount of ammonia gas transmitted by the block layer being 70 g/m2.24 h or less.

Description

Polarizing plate with retardation layer and organic electroluminescence display device using same

The present invention relates to a polarizing plate with retardation layer and an organic electroluminescence (EL, Electroluminescence) display device using the same.

In recent years, with the spread of thin-type displays, a display (organic EL display device) equipped with an organic EL panel has been disclosed. Since the organic EL panel has a metal layer with high reflectivity, problems such as external light reflection and background reflection are likely to occur. Therefore, methods for preventing such problems by providing a circular polarizing plate on the viewing side are known (for example, Patent Document 1 and Patent Document 2). However, the circularly polarizing plate provided in the organic EL display device has a problem of easy discoloration. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-372622 [Patent Document 2] Japanese Patent No. 3325560

[Problems to be Solved by Invention]

The present invention has been made to solve the aforementioned problems, and its main purpose is to provide a polarizing plate with a retardation layer, which can significantly suppress discoloration when the polarizing plate is applied to an organic EL display device. [Technical means to solve problems]

According to an embodiment of the present invention, a polarizing plate with a retardation layer is provided. The polarizing plate with retardation layer has a polarizing element and a barrier layer disposed on one side of the polarizing element and including the retardation layer, and the ammonia gas permeation amount of the barrier layer is 70 g/m ² ·24h or less. In one embodiment, the ammonia gas permeation amount of the retardation layer is 70 g/m ² ·24h or less. In one embodiment, the blocking layer includes a protective layer of the polarizing element. In one embodiment, the ammonia gas permeation amount of the protective layer is 70 g/m ² ·24h or less. In one embodiment, the above-mentioned polarizing plate with retardation layer has a protective layer disposed on the other side of the above-mentioned polarizing element. In one embodiment, the single transmittance of the polarizing element is 40% or more and 45% or less. In one embodiment, Re(450)/Re(550) of the retardation layer is 0.8 or more and less than 1. In one embodiment, the thickness of the polarizing element is 10 μm or less. In one embodiment, the thickness of the polarizing plate with the retardation layer is 150 μm or less. According to another aspect of the present invention, an organic electroluminescence display device is provided. The organic electroluminescence display device has the above-mentioned polarizing plate with retardation layer. [Effect of invention]

According to the embodiment of the present invention, in the polarizing plate with retardation layer, by disposing a layer that satisfies a specific amount of ammonia gas transmission on one side of the polarizing element, discoloration can be significantly suppressed when applied to an organic EL display device. The polarizing plate with retardation layer.

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

(Definition of Terms and Symbols) Definitions of terms and symbols in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index reaches the maximum (ie, the direction of the slow axis), and "ny" is the direction in the plane orthogonal to the slow axis (ie, the direction of the advance axis) The refractive index of , "nz" is the refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re(λ)" is the in-plane retardation measured at 23°C with light having a wavelength of λ nm. For example, "Re(550)" is the in-plane retardation measured at 23°C with light having a wavelength of 550 nm. Re(λ) is obtained from the formula: Re(λ)=(nx−ny)×d when the thickness of the layer (film) is set to d (nm). (3) Phase difference in thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured at 23° C. with light having a wavelength of λ nm. For example, "Rth(550)" is the retardation in the thickness direction measured at 23° C. with light having a wavelength of 550 nm. Rth(λ) is obtained according to the formula: Rth(λ)=(nx−nz)×d when the thickness of the layer (film) is set as 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 a clockwise direction and a counterclockwise direction with respect to the reference direction. Therefore, for example, "45°" means ±45°.

A. Polarizing plate with retardation layer 1 is a schematic cross-sectional view showing a schematic configuration of a polarizing plate with a retardation layer according to an embodiment of the present invention. The polarizing plate 100 with retardation layer includes a polarizing element 11 , a protective layer (visible side protective layer) 12 disposed on the visible side of the polarizing element 11 , and a blocking layer 30 disposed on the opposite side of the polarizing element 11 . The barrier layer 30 includes the protective layer (inside protective layer) 13 of the polarizing element 11 and the retardation layer 20 in this order from the visible side. In this way, the protective layer 13 is disposed on the opposite side to the visible side of the polarizing element 11, and the protective layer 13 may be omitted depending on the purpose or the like. Specifically, the barrier layer 30 may also not contain the protective layer 13 . For example, when the retardation layer 20 is composed of a stretched film of a resin film and can also serve as a protective layer of the polarizer, the protective layer 13 may be omitted. On the other hand, when the retardation layer 20 is an alignment cured layer of a liquid crystal compound, the protective layer 13 is typically disposed. The retardation layer 20 may be a single layer, or may have a laminated structure in which two or more layers are laminated. In addition, the laminated body of a polarizing element and a protective layer is called a polarizing plate. In the illustrated example, the polarizing plate 10 has a polarizing element 11 and protective layers 12 and 13 .

The thickness of the polarizing plate with retardation layer (thickness from the protective layer on the visible side to the retardation layer) is preferably 150 μm or less, more preferably 120 μm or less, further preferably 100 μm or less, particularly preferably 80 μm or less . The lower limit of the thickness of the polarizing plate with retardation layer is preferably 20 μm, more preferably 45 μm. Such a polarizing plate with retardation layer can have excellent flexibility and bending durability, for example. As a result, the polarizing plate with retardation layer can be applied to an organic EL display device capable of bending, bending, bending, and curling.

Although not shown, the polarizing plate with retardation layer may further have other functional layers. The type, characteristic, number, combination, arrangement, etc. of the functional layers that the polarizing plate with retardation layer can have can be appropriately set according to the purpose. For example, the polarizing plate with retardation layer may further have a conductive layer or an isotropic substrate with a conductive layer. The polarizer with retardation layer having a conductive layer or an isotropic substrate with a conductive layer is applied to, for example, an organic EL display device in which a touch sensor is assembled inside an organic EL panel. As another example, the polarizing plate with retardation layer may further have other retardation layers. The optical properties (for example, refractive index properties, in-plane retardation, Nz coefficient, photoelasticity coefficient), thickness, arrangement, and the like of the other retardation layers can be appropriately set according to the purpose. As a specific example, on the viewing side of the polarizing plate 10, another retardation layer (representatively, a layer imparting (elliptically) polarized light function, a layer imparting ultra-high phase difference layer). By having these layers, even when the display screen is viewed through polarized lenses such as polarized sunglasses, excellent visibility can be achieved. Therefore, the obtained polarizing plate (polarizing plate with retardation layer) can also be preferably applied to an image display device that can be used outdoors.

Each member constituting the polarizing plate with retardation layer can be laminated via any appropriate adhesive layer (not shown). As a specific example of an adhesive layer, an adhesive bond layer and an adhesive bond layer are mentioned. Specifically, the retardation layer 20 can be attached to the polarizer 11 or the protective layer 13 via an adhesive layer (preferably using an active energy ray-curable adhesive), or can also be attached to the polarizer 11 or the protective layer 13 via an adhesive layer (eg, an acrylic adhesive). ) is attached to the polarizing element 11 or the protective layer 13 . When the retardation layer 20 has a laminated structure of two or more layers, each retardation layer is bonded via, for example, an adhesive layer (preferably, an active energy ray-curable adhesive). The blocking layer 30 may also include an adhesive layer disposed between the polarizing element 11 and the retardation layer 20 .

Although not shown, practically, an adhesive layer is provided on the opposite side of the retardation layer 20 from the side where the polarizer 11 is arranged (specifically, the outermost layer on the opposite side from the visible side), so that The polarizing plate with retardation layer can be attached to the organic EL panel body. Furthermore, it is preferable to temporarily adhere a release film (separator film) to the surface of the adhesive layer, before the polarizing plate with the retardation layer is used for use. By temporarily adhering the release film, the polarizing plate with the retardation layer can be formed into a roll while protecting the adhesive layer.

The polarizing plate with the retardation layer can be in the shape of a long strip or a single piece. Here, the "stripe shape" refers to an elongated shape whose length is sufficiently long relative to its width, for example, an elongated shape whose length is 10 times or more, preferably 20 times or more than its width. The long polarizing plate with retardation layer can be wound into a roll.

A-1. Barrier layer The ammonia gas permeation amount of the barrier layer 30 is 70 g/m ² · 24h or less, preferably 60 g/m ² · 24h or less, more preferably 50 g/m ² · 24h or less, and more Preferably it is 40 g/m ² · 24h or less, and particularly preferably 30 g/m ² · 24h or less. By providing such a barrier layer, discoloration can be significantly suppressed. The inventors of the present invention directly faced the new problem of decolorization of the polarizing plate with retardation layer when applying the polarizing plate with retardation layer to an organic EL display device, and made intensive research on this problem, and found that , the cause of discoloration comes from ammonia (substantially ammonium ions) that constitute the components of the organic EL panel. With such a blocking layer 30 , the ammonia reaching the polarizing element is blocked as much as possible, whereby discoloration can be significantly suppressed. Specifically, decomposition of a dichroic substance (typically, an iodine complex) contained in the polarizing element can be suppressed. The ammonia gas permeation amount of the barrier layer 30 is, for example, 3.0 g/m ² · 24h or more.

The ammonia gas permeation amount of the barrier layer 30 can be satisfied by at least one layer included in the barrier layer 30 , and can also be satisfied by a combination of two or more layers included in the barrier layer 30 . Specifically, the ammonia transmission amount of the barrier layer 30 can be achieved by the protective layer 13 of the polarizing element 11 , the retardation layer 20 can also be achieved, and can also be achieved by the above-mentioned adhesive layer (for example, an adhesive layer) , can also be achieved by a combination of these. In one embodiment, the ammonia gas permeation amount of both or either of the retardation layer 20 and the protective layer 13 is 70 g/m ² ·24h or less.

The above-mentioned ammonia gas permeation amount can be determined from the difference between the permeation amount of the aqueous ammonia solution and the permeation amount of water.

A-2. Polarizing element The polarizing element described above is typically a film containing a dichroic substance (representatively, iodine).

The thickness of the polarizing element is preferably 15 μm or less, more preferably 12 μm or less, still more preferably 10 μm or less, and particularly preferably 8 μm or less, from the viewpoint of thinning, for example. On the other hand, the thickness of the polarizing element is preferably 1 μm or more, more preferably 2 μm or more, and still more preferably 3 μm or more. When the thickness of the polarizing element is within this range, for example, curling during heating can be suppressed favorably, and favorable appearance durability during heating can be obtained.

The polarizing element preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizing element is, for example, 40.0% or more, preferably 41.5% or more, more preferably 43.0% or more, and still more preferably 44.5% or more. On the other hand, the monomer transmittance may be, for example, 46.0% or less, or 45.0% or less. The polarization degree of the polarizing element is preferably 97.0% or more, more preferably 99.0% or more, and still more preferably 99.9% or more.

The polarizing element can be produced by any appropriate method. Specifically, the polarizing element can be produced from a single-layer resin film, or can also be produced using a laminate of two or more layers.

The above-mentioned method of manufacturing a polarizing element from a single-layer resin film typically includes dyeing and stretching the resin film with a dichroic substance such as iodine or a dichroic dye. As the resin film, for example, hydrophilic polymer films such as polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymer-based partially saponified films are used. From the point of being excellent in optical properties, it is preferable to dye the PVA-based film with iodine and uniaxially extend it to obtain a polarizing element.

The above-mentioned dyeing with iodine can be performed, for example, by immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the above-mentioned uniaxial stretching is preferably 3 to 7 times. The extension can be carried out after dyeing or at the same time as dyeing. In addition, it is also possible to extend and then dye. If necessary, swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc. may be performed on the PVA-based film. For example, by immersing the PVA film in water for washing before dyeing, not only the dirt and anti-blocking agent on the surface of the PVA film can be removed, but also the PVA film can be swelled to prevent uneven dyeing.

Specific examples of the polarizing element obtained by using the above-mentioned laminate include a laminate using a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and coating A polarizing element obtained by a laminate of PVA-based resin layers formed on the resin substrate. A polarizing element obtained by using a laminate of a resin base material and coating a PVA-based resin layer formed on the resin base material can be produced, for example, by the following steps: apply a PVA-based resin solution to a resin base material, and dry it to obtain a polarizing element. A PVA-based resin layer is formed on a 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 polarizer. In this embodiment, it is preferable to form the polyvinyl-alcohol-type resin layer containing a halide and a polyvinyl-alcohol-type resin on one side of a resin base material. The stretching is typically performed by dipping the layered body in an aqueous solution of boric acid. Furthermore, the stretching may further include performing in-air stretching of the laminate at a high temperature (eg, 95° C. or higher) before stretching in a boric acid aqueous solution. In addition, in this embodiment, it is preferable to perform a drying shrinkage process on a laminated body, and this drying shrinkage process is made to shrink by 2% or more in the width direction by heating while being conveyed in the longitudinal direction. Typically, the manufacturing method of the present embodiment includes sequentially applying an in-air stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment to the laminate. By introducing auxiliary stretching, even in the case of coating PVA on a thermoplastic resin, the crystallinity of PVA can be improved, and higher optical properties can be achieved. In addition, by simultaneously improving the orientation of PVA in advance, when immersed in water in the subsequent dyeing step and stretching step, problems such as decrease in the orientation of PVA and dissolution can be prevented, thereby achieving higher optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, compared with the case where the PVA-based resin layer does not contain a halide, the alignment disorder of the polyvinyl alcohol molecules and the decrease in alignment can be suppressed. Thereby, the optical characteristics of the polarizing element obtained by the process steps of immersing the laminated body in liquid, such as a dyeing process and an underwater extension process, can be improved. Furthermore, optical characteristics can be improved by shrinking the laminate in the width direction by drying shrinkage treatment. The obtained laminate of resin substrate/polarizing element can be used as it is (that is, the resin substrate can be used as a protective layer of the polarizing element), or the resin substrate can be peeled off from the laminate of resin substrate/polarizing element. The peeling surface or the surface opposite to the peeling surface is used by laminating any appropriate protective layer according to the purpose. The 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 . All the descriptions of these gazettes are incorporated herein by reference.

A-3. Protective layer The above-mentioned protective layer is composed of any appropriate film that can be used as a protective layer of a polarizing element. Examples of materials constituting the protective layer include cellulose-based resins such as triacetyl cellulose (TAC, Triacetyl Cellulose), cycloolefin-based resins such as polynorbornene, (meth)acrylic-based resins, and polyterephthalene. Polyester resins such as ethylene formate (PET, Polyethylene Terephthalate) and polyethylene naphthalate (PEN, Polyethylene Naphthalate), polyolefin resins such as polyethylene, and polycarbonate resins. As a representative example of a (meth)acrylic-type resin, the (meth)acrylic-type resin which has a lactone ring structure is mentioned. (Meth)acrylic resins having a lactone ring structure are described in, for example, Japanese Patent Laid-Open No. 2000-230016, Japanese Patent Laid-Open No. 2001-151814, Japanese Patent Laid-Open No. 2002-120326, and Japanese Patent Laid-Open Publication No. 2001-151814. No. 2002-254544, Japanese Patent Laid-Open No. 2005-146084. These gazettes are incorporated herein by reference.

The polarizing plate with retardation layer is typically arranged on the visible side of the organic EL display device, and the protective layer 12 on the visible side can also be subjected to surface treatments such as hard coating treatment, anti-reflection treatment, anti-sticking treatment, and anti-glare treatment as needed. .

The thickness of the visible-side protective layer 12 can be appropriately set. The thickness of the visible-side protective layer 12 is preferably 10 μm to 80 μm, more preferably 15 μm to 70 μm, and still more preferably 20 μm to 50 μm. Furthermore, in the case of performing surface treatment, the thickness of the visible side protective layer 12 is the thickness including the surface treatment layer.

In one embodiment, the ammonia gas permeation amount of the protective layer 13 is 70 g/m ² · 24h or less, preferably 60 g/m ² · 24h or less, more preferably 50 g/m ² · 24h or less, and more Preferably it is 40 g/m ² · 24h or less, and particularly preferably 30 g/m ² · 24h or less. In this case, as the material constituting the protective layer 13, it is preferable to use at least one selected from the group consisting of cellulose-based resins, cycloolefin-based resins, and polyester-based resins.

In one embodiment, the protective layer 13 is preferably optically isotropic. In this specification, "being optically isotropic" 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 protective layer 13 can be appropriately set, for example, according to the required amount of ammonia gas permeation. The thickness of the protective layer 13 is preferably 10 μm to 80 μm, more preferably 20 μm to 70 μm, and still more preferably 30 μm to 50 μm. When the retardation layer 20 is a stretched film of a resin film, the protective layer 13 may be omitted, for example, from the viewpoint of thinning.

A-4. Retardation layer The retardation layer 20 may be a single layer or may have a laminated structure (substantially a two-layer structure).

When the retardation layer 20 is a single layer, the retardation layer 20 can typically function as a λ/4 plate. The retardation layer is typically provided to impart antireflection properties to the organic EL display device. The retardation layer typically exhibits a relationship of nx>ny=nz in refractive index characteristics. The in-plane retardation Re(550) of the retardation layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and still more preferably 120 nm to 160 nm. Furthermore, here "ny=nz" not only refers to the case where ny and nz are completely equal, but also includes the case where they are substantially equal. Therefore, in the range which does not impair the effect of this invention, the situation of ny>nz or ny<nz may exist.

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

When the retardation layer is a single layer, the retardation layer preferably exhibits an inverse wavelength dispersion characteristic in which the retardation value increases according to the wavelength of the measurement light. In this case, Re(450)/Re(550) of the retardation layer is preferably 0.8 or more and less than 1, more preferably 0.8 or more and 0.95 or less. With such a configuration, very excellent antireflection properties 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 further preferably about 45°. If the angle is within this range, by making the retardation layer a λ/4 plate as described above, an organic EL display device having very excellent antireflection properties can be obtained.

The retardation layer may be composed of any appropriate material as long as the above-mentioned characteristics are satisfied. Specifically, the retardation layer may be a stretched film of a resin film or an alignment cured layer of a liquid crystal compound (hereinafter referred to as a liquid crystal alignment cured layer).

When the retardation layer is a stretched film of a resin film, as a representative example of the resin constituting the resin film, a polycarbonate-based resin or a polyester-carbonate-based resin (hereinafter sometimes referred to as a polycarbonate-based resin) can be mentioned. ). As the polycarbonate-based resin, any appropriate polycarbonate-based resin can be used as long as the desired moisture permeability is obtained. For example, the polycarbonate-based resin contains: a structural unit derived from a perylene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit derived from a group selected from alicyclic diol, alicyclic dimethanol, di-, tri- Or polyethylene glycol, and a structural unit of at least one dihydroxy compound of the group consisting of alkylene glycol or spiroglycol. The polycarbonate-based resin preferably comprises: a structural unit derived from a perylene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, a structural unit derived from alicyclic dimethanol and/or a structural unit derived from di-, tri- or polymeric compounds. The structural unit of ethylene glycol; further preferably, it comprises: a structural unit derived from a perylene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit derived from di-, tri- or polyethylene glycol. The polycarbonate-based resin may also contain structural units derived from other dihydroxy compounds as required. A retardation layer can be formed by extending|stretching the film which consists of the polycarbonate-type resin mentioned above under arbitrary appropriate extending|stretching conditions. In addition, the details of the method of forming the polycarbonate-based resin and the retardation layer are described in, for example, Japanese Patent Laid-Open No. 2014-10291, Japanese Patent Laid-Open No. 2014-26266, and Japanese Patent Laid-Open No. 2015-212816. , Japanese Patent Laid-Open No. 2015-212817, Japanese Patent Laid-Open No. 2015-212818, Japanese Patent Laid-Open No. 2017-54093, and Japanese Patent Laid-Open No. 2018-60014. The descriptions of these gazettes are incorporated herein by reference.

When the retardation layer is a liquid crystal alignment cured layer, by using a liquid crystal compound, the difference between nx and ny of the obtained retardation layer can be significantly increased compared with the non-liquid crystal material, so it can be used to obtain the desired The thickness of the retardation layer with the in-plane retardation is significantly reduced. As a result, further thinning of the polarizing plate with a retardation layer (resulting in an organic EL display device) can be achieved. In this specification, the "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. In addition, the "alignment hardening layer" includes the concept of the alignment hardening layer obtained by hardening a liquid crystal monomer. In the present embodiment, the rod-shaped liquid crystal compound is typically aligned (horizontal alignment) in a state of being arranged in the direction of the retardation axis of the retardation layer. Specific examples of the liquid crystal compound and details of the method for forming the liquid crystal alignment cured layer are described in, for example, Japanese Patent Laid-Open No. 2006-163343 and Japanese Patent Laid-Open No. 2006-178389. The descriptions of these gazettes are incorporated herein by reference.

The thickness of the retardation layer can typically be set to a thickness that can function appropriately as a λ/4 plate. When the retardation layer is a stretched film of a resin film, the thickness of the retardation layer may be, for example, 10 μm to 60 μm. When the retardation layer is a liquid crystal alignment cured layer, the thickness of the retardation layer may be, for example, 1 μm˜5 μm.

When the retardation layer 20 has a laminated structure, the retardation layer typically has a two-layer structure of a first liquid crystal alignment cured layer and a second liquid crystal alignment cured layer. In this case, either the first liquid crystal alignment cured layer or the second liquid crystal alignment cured layer can function as a λ/2 plate, and the other can function as a λ/4 plate. Here, the case where the first liquid crystal alignment cured layer can function as a λ/2 plate and the second liquid crystal alignment cured layer can function as a λ/4 plate will be described, and vice versa. The thickness of the first liquid crystal alignment cured layer can be adjusted so that the required in-plane retardation of the λ/2 plate can be obtained, for example, it can be 2.0 μm to 4.0 μm. The thickness of the second liquid crystal alignment cured layer can be adjusted so that the required in-plane retardation of the λ/4 plate can be obtained, for example, it can be 1.0 μm to 2.5 μm. The in-plane retardation Re(550) of the first liquid crystal alignment cured layer is preferably 200 nm to 300 nm, more preferably 230 nm to 290 nm, and still more preferably 250 nm to 280 nm. As described above, the in-plane retardation Re(550) of the second liquid crystal alignment cured layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and more preferably 120 nm to 160 nm. The angle formed by the retardation axis of the first liquid crystal alignment cured layer and the absorption axis of the polarizer is preferably 10° to 20°, more preferably 12° to 18°, and more preferably about 15°. The angle formed by the retardation axis of the second liquid crystal alignment cured layer and the absorption axis of the polarizer is preferably 70° to 80°, more preferably 72° to 78°, and more preferably about 75°. With such a configuration, properties close to ideal reverse wavelength dispersion properties can be obtained, and as a result, very excellent antireflection properties can be realized.

In one embodiment, the ammonia gas permeation amount of the retardation layer 20 is 70 g/m ² ·24h or less, preferably 60 g/m ² ·24h or less, more preferably 50 g/m ² ·24h or less, and further It is preferably 40 g/m ² · 24h or less, and particularly preferably 30 g/m ² · 24h or less. In this case, the retardation layer 20 is preferably a stretched film of the above-mentioned resin film. As for the constituent material of the protective layer 13 to be combined with the retardation layer 20 as the stretched film of the resin film, at least one selected from the group consisting of cycloolefin-based resins and polyester-based resins is preferably used. By this combination, discoloration can be suppressed extremely significantly.

As for the constituent material of the protective layer 13 combined with the retardation layer 20 as the liquid crystal alignment cured layer, it is preferable to use a cellulose-based resin. By this combination, discoloration can be suppressed extremely significantly.

B. Organic EL Display Device The above-mentioned polarizing plate with retardation layer can be applied to an organic EL display device. Therefore, the organic EL display device according to the embodiment of the present invention has the above-mentioned polarizing plate with retardation layer.

2 is a schematic cross-sectional view showing a state in which a polarizing plate with a retardation layer is arranged on an organic EL panel in an organic EL display device according to an embodiment of the present invention. The polarizing plate 100 with retardation layer is arranged so that the blocking layer 30 is closer to the side of the organic EL panel body 40 than the polarizing element 11 is. Specifically, the polarizing plate 100 with a retardation layer is attached to the organic EL panel body 40 through an adhesive layer (not shown). The organic EL panel body 40 has a substrate 60 and an upper structure layer 80, wherein the upper structure layer 80 includes: a circuit layer including a thin film transistor (TFT, Thin-Film Transistor), an organic light-emitting diode (OLED, Organic Light-Emitting). Diode), and sealing film for sealing OLED, etc. The upper structure layer 80 contains, for example, a nitrogen-containing layer (eg, a nitride layer), and ammonia (ammonium) may be generated from the upper structure layer 80 . The above-mentioned polarizing plate with retardation layer can significantly suppress discoloration in an organic EL display device. In addition, the problem of discoloration can be solved without changing the design of the structure of the organic EL panel body.

For example, in the case of using a flexible substrate (eg, a resin substrate) as the substrate 60, the obtained organic EL display device can realize bending, bending, bending, curling, and the like. [Example]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. Furthermore, unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight. (1) The thickness of 10 μm or less was measured using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd., product name “MCPD-3000”). The thickness exceeding 10 μm was measured using a digital micrometer (manufactured by Anritsu Corporation, product name “KC-351C”). (2) Two cups A and B were prepared for ammonia gas permeation, and 150 g of 10% ammonia solution was added to cup A, and 150 g of water was added to cup B, and cut into a circular test piece with a diameter of 6 cm. (film) was sealed, cups A and B were allowed to stand in an oven set at 40°C (under atmospheric pressure) for 24 hours, and the weight changes of cups A and B before and after standing were measured. Calculate the difference between the weight change of cup A (permeation amount of ammonia gas and water) and the weight change amount of cup B (permeation amount of water) to obtain the permeation rate of ammonia gas (g/m ²・24h).

[Example 1] 1. Fabrication of polarizing element As the thermoplastic resin, an amorphous poly(ethylene terephthalate) film (thickness: 100 μm) in the shape of a long strip with a water absorption rate of 0.75% and a Tg (glass transition temperature) of about 75°C was used. substrate. Corona treatment is performed on one side of the resin substrate. PVA obtained by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetylacetate modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z410") at a ratio of 9:1 13 parts by weight of potassium iodide was added to 100 parts by weight of the resin, and this was dissolved in water to prepare an aqueous PVA solution (coating liquid). The above-mentioned PVA aqueous solution was coated on the corona-treated surface of the resin substrate and dried at 60° C. to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched 2.4 times at the free end in the longitudinal direction (longitudinal direction) between rolls having different circumferential speeds in an oven at 130° C. (in-air stretching treatment). Next, the layered body was immersed for 30 seconds in an insolubilization bath (a boric acid aqueous solution obtained by blending 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, face a dyeing bath with a liquid temperature of 30° C. (with respect to 100 parts by weight of water, an iodine aqueous solution obtained by preparing iodine and potassium iodide in a weight ratio of 1:7) to make the monomer transmittance of the polarizing film finally obtained ( Ts, single transmittance) was 43.0% to adjust the concentration, and one side was immersed in it for 60 seconds (dyeing treatment). Next, it was immersed for 30 seconds 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 (crosslinking treatment). After that, the layered body was immersed in an aqueous solution of boric acid (boric acid concentration 4.0 wt %, potassium iodide 5.0 wt %) at a liquid temperature of 70° C., and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different circumferential speeds to The total extension magnification was 5.5 times (in-water extension treatment). Then, the layered body was immersed in a cleaning bath (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 20°C (cleaning treatment). Then, it was made to contact with the heating roll made of SUS (Steel Use Stainless) whose surface temperature was maintained at 75 degreeC for about 2 second (drying shrinkage process), drying in the oven maintained at 90 degreeC. The shrinkage rate in the width direction of the laminate after 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 On the surface of the polarizing element of the resin substrate/polarizing element laminate obtained by the above steps, a TAC film with a thickness of 25 μm is pasted through an ultraviolet curable adhesive. Specifically, it was applied so that the thickness of the hardening adhesive would be 1.0 μm, and it was bonded using a roller press. Then, the adhesive was cured by irradiating UV (Ultraviolet) light rays from the TAC film side. Next, the resin base material was peeled off from the polarizer, and a cycloolefin-based resin film (thickness 13 μm, ammonia gas permeation amount 54 g/m ² ·24 h: hereinafter referred to as COP (Cyclo Olefin Polymer) film). In this way, a polarizing plate having a configuration of TAC film/polarizing element/COP film was obtained.

3. Production of retardation film constituting retardation layer 3-1. Polymerization of polyester carbonate-based resin Polymerization was performed using a batch polymerization apparatus including two vertical reactors equipped with stirring blades and control It is a reflux condenser at 100°C. 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)perpen-9-yl]methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB, Isosorbide), spirobi Alcohol (SPG, Spiroglycol) 42.28 parts by mass (0.139 mol), Diphenyl Carbonate (DPC, Diphenyl Carbonate) 63.77 parts by mass (0.298 mol) and calcium acetate monohydrate as a catalyst 1.19× ^10-2 parts by mass (6.78× 10 ^-5 mol). After the inside of the reactor was replaced with nitrogen under reduced pressure, it was heated with a heating medium, and stirring was started when the internal temperature reached 100°C. 40 minutes after the start of temperature increase, the internal temperature was brought to 220°C, and the pressure was reduced to 13.3 kPa 90 minutes after the pressure reached 220°C while controlling the internal temperature to maintain the temperature. The phenol vapor accompanying the polymerization reaction by-product was led to a reflux condenser at 100°C, and some monomer components contained in the phenol vapor were returned to the reactor, and the uncondensed phenol vapor was led to a condenser of 45°C for recovery. After nitrogen gas was introduced into the first reactor and the pressure was temporarily restored to atmospheric pressure, the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Then, the temperature increase and pressure reduction in the second reactor were started, and the internal temperature reached 240° C. and the pressure was 0.2 kPa in 50 minutes. Thereafter, polymerization is carried out until a specific stirring power is reached. When the specific power is reached, nitrogen gas is introduced into the reactor to re-pressurize, the produced polyester carbonate-based resin is extruded into water, and the strands are cut to obtain pellets.

3-2. Production of retardation film The obtained polyester carbonate-based resin (particulate matter) was vacuum-dried at 80° C. for 5 hours, and then a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250°C) was used. °C), T-die (width 200 mm, set temperature: 250 °C), cooling roll (set temperature: 120-130 °C), and film making device of a coiler, to produce a long resin film with a thickness of 135 μm . The obtained long resin film was stretched in the width direction at a stretching temperature of 133° C. and a stretching ratio of 2.8 times to obtain a retardation film with a thickness of 47 μm. Re(550) of the obtained retardation film was 141 nm, Re(450)/Re(550) was 0.82, and Nz coefficient was 1.12. In addition, the ammonia gas permeation amount of the obtained retardation film was 10 g/m ² ·24h.

4. Preparation of adhesive 4-1. Preparation of acrylic polymer Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a condenser, 91 parts of butyl acrylate, 6 parts of acryloylmorpholine (ACMO, 4-acryloylmorpholine), 2.7 parts of acrylic acid, and 4-hydroxy acrylic acid were charged Monomer mixture of 0.3 part of butyl ester. Furthermore, with respect to 100 parts of this monomer mixture, 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts of ethyl acetate, and nitrogen gas was introduced while stirring slowly. After the replacement, the liquid temperature in the flask was maintained at around 55°C, and a polymerization reaction was performed for 8 hours to prepare an acrylic polymer solution.

4-2. Preparation of adhesive A trimethylolpropane/toluene diisocyanate adduct (manufactured by Tosoh Corporation, trade name "Coronate L") was prepared with respect to 100 parts of solid content of the obtained acrylic polymer solution. ) 0.1 part, 0.3 part of a peroxide crosslinking agent (benzyl peroxide), and 0.2 part of an epoxy group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403") to obtain an adhesive. The ammonia gas permeation of the obtained adhesive (thickness 20 μm) was 118 g/m ² ·24h.

5. Production of polarizing plate with retardation layer The retardation film obtained by the above 3. was bonded to the COP film surface of the polarizing plate obtained by the above 2. through the adhesive (thickness 20 μm) obtained by the above 4. At this time, bonding was performed so that the absorption axis of the polarizing element and the retardation axis of the retardation film formed an angle of 45°. In this way, a polarizing plate with retardation layer is obtained.

[Example 2] In the production of the polarizing plate, a PET film (thickness 30 μm, ammonia gas permeation amount 53 g/m ² · 24 h) was used instead of the COP film, and the same procedure as in Example 1 was carried out to obtain a phase attached. The polarizing plate of the poor layer.

[Example 3] In the production of the polarizing plate, a TAC film (thickness 25 μm, ammonia gas permeation 30 g/m ² ·24 h) was used instead of the COP film, and the same procedure as in Example 1 was performed to obtain a phase attached. The polarizing plate of the poor layer.

[Example 4] In the production of the polarizing plate, an acrylic resin film with a lactone ring structure (thickness 20 μm, ammonia gas permeability 78 g/m ² ·24h) was used instead of the COP film, except that the same as Example 1 In the same way, a polarizing plate with retardation layer was obtained.

[Example 5] In the production of the polarizing plate, except that the COP film was not bonded to the polarizing element using an ultraviolet curable adhesive, it was carried out in the same manner as in Example 1 to obtain a polarizing plate with a retardation layer.

[Example 6] Except having used the following liquid crystal alignment cured layer as a retardation layer, it carried out similarly to Example 1, and obtained the polarizing plate with retardation layer.

(Production of liquid crystal alignment cured layer constituting retardation layer) 55 parts of compound represented by formula (I), 25 parts of compound represented by formula (II), and 20 parts of compound represented by formula (III) were added to cyclopentane After adding 400 parts of ketone (CPN, Cyclopentanone), it was heated to 60° C., stirred and dissolved. After confirming the dissolution, it was returned to room temperature, and 3 parts of Irgacure 907 (manufactured by BASF Japan Co., Ltd.), MEGAFAC F- 0.2 part of 554 (manufactured by DIC Co., Ltd.) and 0.1 part of p-methoxyphenol (MEHQ, 4-Methoxyphenol) were further stirred to obtain a solution. The solution is clear and homogeneous. The obtained solution was filtered with a 0.20 μm membrane filter to obtain a polymerizable composition. On the other hand, a polyimide solution for an alignment film was coated on a glass substrate with a thickness of 0.7 mm 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 is subjected to a rubbing treatment to form an alignment film. The rubbing treatment was performed using a commercially available rubbing device. The polymerizable composition obtained by the above steps was coated on a substrate (substantially an alignment film) by a spin coating method, and dried at 100° C. for 2 minutes. After cooling the obtained coating film to room temperature, a high-pressure mercury lamp was used to irradiate ultraviolet rays with an intensity of 30 mW/cm ² for 30 seconds to obtain a liquid crystal alignment cured layer. The in-plane retardation Re(550) of the obtained liquid crystal alignment cured layer was 130 nm, Re(450)/Re(550) was 0.851, and the liquid crystal alignment cured layer exhibited reverse wavelength dispersion characteristics. In addition, the ammonia gas permeation amount of the obtained liquid crystal alignment cured layer was 103 g/m ² ·24h.

[化2]

[hua 1]

[hua 2]

[Example 7] In the production of the polarizing plate, a TAC film (thickness 25 μm, ammonia gas permeability 30 g/m ² ·24h) was used instead of the COP film, and the above-mentioned liquid crystal alignment cured layer was used as the retardation layer. When combining with a polarizing plate, it carried out similarly to Example 1, except having used the ultraviolet curable adhesive (1.0 micrometers in thickness) without using the said adhesive agent, and obtained the polarizing plate with retardation layer.

[Comparative Example 1] In the production of the polarizing plate, a TAC film with a thickness of 40 μm was used instead of the TAC film with a thickness of 25 μm, and an acrylic resin film with a lactone ring structure (thickness 20 μm, ammonia gas transmission rate 78 g/m) was used ^2.24h ) Except having used the above-mentioned liquid crystal alignment cured layer as a retardation layer instead of the COP film, it carried out similarly to Example 1, and obtained the polarizing plate with retardation layer.

[Comparative Example 2] In the production of the polarizing plate, a TAC film with a thickness of 40 μm was used instead of the TAC film with a thickness of 25 μm, and the above-mentioned liquid crystal alignment cured layer was used as the retardation layer. the polarizer.

[Comparative Example 3] In the production of the polarizing plate, an acrylic resin film with a lactone ring structure (thickness 20 μm) was used instead of the TAC film with a thickness of 25 μm, and an acrylic resin film with a lactone ring structure (thickness 20 μm, A polarizing plate with a retardation layer was obtained in the same manner as in Example 1, except that the ammonia gas permeation amount was 78 g/m ² 24h) instead of the COP film and the above-mentioned liquid crystal alignment cured layer was used as the retardation layer.

The following evaluation was performed about the Example and the comparative example. The evaluation results are summarized in Table 1 together with the constitution of the polarizing plate (barrier layer) with retardation layer. <Evaluation> ○Single transmittance and degree of polarization Regarding the polarizing plates of the examples and comparative examples, the single transmittance Ts, parallel transmittance measured using an ultraviolet-visible spectrophotometer ("LPF-2000" manufactured by Otsuka Electronics Co., Ltd.) The rate Tp (parallel transmittance) and the orthogonal transmittance Tc (crossed transmittance) are respectively used as Ts, Tp and Tc of the polarizing element. These Ts, Tp, and Tc are Y values measured by the 2-degree field of view (C light source) of JIS Z8701 and corrected for visual sensitivity. From the obtained Tp and Tc, the polarization degree P was calculated|required by the following formula. Polarization degree P(%)={(Tp－Tc)/(Tp＋Tc)} ^1/2 × 100 ○Ammonia decolorization test Add 10% ammonia solution to a glass bottle (30 mm diameter, 50 mm depth cylindrical shape) 10 g, cover the opening of the glass bottle (the retardation layer is in contact with the opening) with the polarizing plate with the retardation layer obtained in Examples and Comparative Examples, and then heat the glass bottle at 65 ° C for 2 Hour. After heating, the degree of polarization of the portion corresponding to the opening of the glass bottle was measured, and the degree of polarization of the polarizing plate (substantially a polarizing element) with retardation layer before heating was set as P, and the degree of polarization after heating was set as P ', and ΔP was calculated according to the following formula. The smaller ΔP is, the more it means that decolorization by ammonia is suppressed. ΔP=P-P'

[Table 1] barrier Before decolorization test After decolorization test ΔP % The protective layer adhesive layer retardation layer type Ammonia gas permeability g/m ²・24h Ammonia gas permeability g/m ²・24h type Ammonia gas permeability g/m ²・24h P % P' % Example 1 COP 54 118 membrane 10 99.99 99.94 0.05 Example 2 PET 53 118 membrane 10 99.99 99.93 0.06 Example 3 TAC 30 118 membrane 10 99.99 99.25 1.74 Example 4 Acrylic 78 118 membrane 10 99.99 99.88 0.11 Example 5 - - 118 membrane 10 99.99 99.92 0.07 Example 6 COP 54 118 liquid crystal 103 99.99 89.57 10.42 Example 7 TAC 30 - liquid crystal 103 99.99 98.28 1.71 Comparative Example 1 Acrylic 78 118 liquid crystal 103 99.99 65.71 34.28 Comparative Example 2 - - 118 liquid crystal 103 99.99 43.23 56.76 Comparative Example 3 Acrylic 78 118 liquid crystal 103 99.99 12.39 87.60

In the examples, ΔP was less than 20%, and even when exposed to ammonia, a polarizing plate with a retardation layer with little change in the degree of polarization (no discoloration) was obtained. On the other hand, in the comparative example, the degree of polarization was greatly reduced, and it was even confirmed that the polarization function basically disappeared. [Industrial Availability]

The polarizing plate with retardation layer of the present invention can be preferably used as an anti-reflection circular polarizing plate for an organic EL display device, for example.

10: Polarizer 11: Polarizing element 12: Protective layer (visible side protective layer) 13: Protective layer (inside protective layer) 20: retardation layer 30: Barrier 40: Organic EL panel body 60: Substrate 80: Superstructure layer 100: Polarizing plate with retardation layer

1 is a schematic cross-sectional view showing a schematic configuration of a polarizing plate with a retardation layer according to an embodiment of the present invention. 2 is a schematic cross-sectional view showing a state in which a polarizing plate with a retardation layer is arranged on an organic EL panel in an organic EL display device according to an embodiment of the present invention.

10: Polarizer

11: Polarizing element

12: Protective layer (visible side protective layer)

13: Protective layer (inside protective layer)

20: retardation layer

30: Barrier

100: Polarizing plate with retardation layer

Claims (10)

A polarizing plate with a retardation layer, comprising: a polarizing element, and a barrier layer disposed on one side of the polarizing element and comprising a retardation layer, wherein the ammonia gas transmission amount of the barrier layer is 70 g/m ² ·24h or less . The polarizing plate with retardation layer according to claim 1, wherein the ammonia gas transmission amount of the retardation layer is 70 g/m ² ·24h or less. The polarizing plate with retardation layer according to claim 1 or 2, wherein the blocking layer comprises the protective layer of the polarizing element. The polarizing plate with retardation layer according to claim 3, wherein the ammonia gas transmission amount of the protective layer is 70 g/m ² ·24h or less. The polarizing plate with retardation layer according to any one of claims 1 to 4, which has a protective layer disposed on the other side of the polarizing element. The polarizing plate with retardation layer according to any one of claims 1 to 5, wherein the single transmittance of the polarizing element is 40% or more and 45% or less. The polarizing plate with retardation layer according to any one of claims 1 to 6, wherein Re(450)/Re(550) of the retardation layer is 0.8 or more and less than 1. The polarizing plate with retardation layer according to any one of claims 1 to 7, wherein the thickness of the polarizing element is 10 μm or less. The polarizing plate with retardation layer according to any one of claims 1 to 8, whose thickness is 150 μm or less. An organic electroluminescence display device having the polarizing plate with retardation layer according to any one of claims 1 to 9.

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