JP2017161606A - Polarizing plate with optical compensation layer and organic EL panel using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate with an optical compensation layer, which has excellent antireflective characteristics in an oblique direction while maintaining excellent antireflective characteristics in a frontal direction.SOLUTION: The polarizing plate with an optical compensation layer of the present invention is to be applied to an organic EL panel. The polarizing plate with an optical compensation layer includes a polarizer, a first optical compensation layer, a second optical compensation layer and a third optical compensation layer. The first optical compensation layer shows a refractive index characteristic represented by nx>nz>ny and has a Re(550) of 230 nm to 310 nm. The second optical compensation layer shows a refractive index characteristic represented by nx>ny≥nz and has a Re(550) of 100 nm to 180 nm, satisfying a relationship of Re(450)<Re(550). The third optical compensation layer shows a refractive index characteristic represented by nz>nx≥ny and has a Rth(550) of -260 nm to -10 nm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polarizing plate with an optical compensation layer and an organic EL panel using the same.

  In recent years, with the widespread use of thin displays, displays (organic EL display devices) equipped with organic EL panels have been proposed. Since the organic EL panel has a highly reflective metal layer, problems such as external light reflection and background reflection tend to occur. Thus, it is known to prevent these problems by providing a circularly polarizing plate on the viewing side. As a general circularly polarizing plate, a retardation film (typically a λ / 4 plate) is laminated so that its slow axis forms an angle of about 45 ° with respect to the absorption axis of the polarizer. Are known. In addition, in order to further improve the antireflection characteristics, attempts have been made to laminate retardation films (optical compensation layers) having various optical characteristics. However, all of the conventional circularly polarizing plates have a problem that the reflectance in the oblique direction is large (that is, the antireflection characteristics in the oblique direction are insufficient).

Japanese Patent No. 3325560

  The present invention has been made to solve the above-described conventional problems, and the main object of the present invention is to provide an optical compensation layer with excellent antireflection characteristics in the oblique direction while maintaining excellent antireflection characteristics in the front direction. It is to provide a polarizing plate.

The polarizing plate with an optical compensation layer of the present invention is used for an organic EL panel. This polarizing plate with an optical compensation layer includes a polarizer, a first optical compensation layer, a second optical compensation layer, and a third optical compensation layer. The first optical compensation layer exhibits a refractive index characteristic of nx>nz> ny, and Re (550) is 230 nm to 310 nm; the second optical compensation layer has a refractive index characteristic of nx> ny ≧ nz Re (550) is 100 nm to 180 nm and satisfies the relationship of Re (450) <Re (550); the third optical compensation layer exhibits a refractive index characteristic of nz> nx ≧ ny, and Rth (550) is -260 nm to -10 nm. Here, Re (450) and Re (550) represent in-plane retardation measured with light having a wavelength of 450 nm and 550 nm at 23 ° C., respectively, and Rth (550) is measured with light having a wavelength of 550 nm at 23 ° C. Represents the retardation in the thickness direction.
In one embodiment, the Nz coefficient of the first optical compensation layer is 0.1 to 0.4, and the absorption axis direction of the polarizer and the slow axis direction of the first optical compensation layer are The angle between the absorption axis of the polarizer and the slow axis of the second optical compensation layer is 35 ° to 55 °. In another embodiment, the Nz coefficient of the first optical compensation layer is 0.6 to 0.9, and the absorption axis direction of the polarizer and the slow axis direction of the first optical compensation layer are The angle between the absorption axis of the polarizer and the slow axis of the second optical compensation layer is 35 ° to 55 °.
In one embodiment, the polarizing plate with an optical compensation layer has a long shape, and the second optical compensation layer has a slow axis in a direction of 35 ° to 55 ° with respect to the longitudinal direction.
According to another aspect of the present invention, an organic EL panel is provided. This organic EL panel includes the above polarizing plate with an optical compensation layer.

  According to the present invention, in the polarizing plate with an optical compensation layer, the first optical compensation layer having a refractive index characteristic of nx> nz> ny and having a predetermined in-plane retardation, and nx> ny ≧ nz A second optical compensation layer exhibiting refractive index characteristics, having a predetermined in-plane retardation, and exhibiting wavelength dependence of inverse dispersion; exhibiting refractive index characteristics of nz> nx ≧ ny; By disposing the third optical compensation layer having a thickness direction retardation, a polarizing plate with an optical compensation layer having excellent antireflection characteristics in the front direction and excellent antireflection characteristics in the oblique direction is obtained. be able to.

It is a schematic sectional drawing of the polarizing plate with an optical compensation layer by one Embodiment of this invention.

  Hereinafter, although preferable embodiment of this invention is described, this invention is not limited to these embodiment.

(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 in which the in-plane refractive index is maximum (ie, the slow axis direction), and “ny” is the direction orthogonal to the slow axis in the plane (ie, the fast axis direction). “Nz” is the refractive index in the thickness direction.
(2) In-plane retardation (Re)
“Re (λ)” is an in-plane retardation measured with light having a wavelength of λ nm at 23 ° C. Re (λ) is obtained by the formula: Re = (nx−ny) × d, where d (nm) is the thickness of the layer (film). For example, “Re (550)” is an in-plane retardation measured with light having a wavelength of 550 nm at 23 ° C.
(3) Thickness direction retardation (Rth)
“Rth (λ)” is a retardation in the thickness direction measured with light having a wavelength of λ nm at 23 ° C. Rth (λ) is determined by the formula: Rth = (nx−nz) × d, where d (nm) is the thickness of the layer (film). For example, “Rth (550)” is a retardation in the thickness direction measured with light having a wavelength of 550 nm at 23 ° C.
(4) Nz coefficient The Nz coefficient is obtained by Nz = Rth / Re.
(5) Substantially orthogonal or parallel The expressions “substantially orthogonal” and “substantially orthogonal” include the case where the angle between the two directions is 90 ° ± 10 °, preferably 90 ° ± 7 °. And more preferably 90 ° ± 5 °. The expressions “substantially parallel” and “substantially parallel” include the case where the angle between two directions is 0 ° ± 10 °, preferably 0 ° ± 7 °, more preferably 0 ° ± 5 °. Further, in the present specification, the term “orthogonal” or “parallel” may include a substantially orthogonal state or a substantially parallel state.

A. 1 is a schematic sectional view of a polarizing plate with an optical compensation layer according to one embodiment of the present invention. The polarizing plate 100 with an optical compensation layer of this embodiment includes a polarizer 10, a first optical compensation layer 30, a second optical compensation layer 40, and a third optical compensation layer 50. In the illustrated example, the first optical compensation layer 30, the second optical compensation layer 40, and the third optical compensation layer 50 are arranged in order from the polarizer 10 side. The order of arrangement of the optical compensation layers 50 may be changed. Practically, the protective layer 20 can be provided on the opposite side of the polarizer 10 from the first optical compensation layer 30 as in the illustrated example. Further, the polarizing plate with an optical compensation layer may include another protective layer (also referred to as an inner protective layer) between the polarizer 10 and the first optical compensation layer 30. In the illustrated example, the inner protective layer is omitted. In this case, the first optical compensation layer 30 can also function as an inner protective layer. With such a configuration, the polarizing plate with an optical compensation layer can be further reduced in thickness. Furthermore, if necessary, a conductive layer and a base material may be provided in this order on the opposite side of the third optical compensation layer 50 from the second optical compensation layer 40 (that is, outside the third optical compensation layer 50). Good (both not shown). The base material is closely adhered to the conductive layer. In the present specification, “adhesion lamination” means that two layers are directly and firmly laminated without an adhesive layer (for example, an adhesive layer or an adhesive layer). The conductive layer and the base material can be typically introduced into the polarizing plate 100 with an optical compensation layer as a laminate of the base material and the conductive layer. By further providing a conductive layer and a substrate, the polarizing plate 100 with an optical compensation layer can be suitably used for an inner touch panel type input display device.

  The first optical compensation layer 30 has a relationship of refractive index nx> nz> ny and has a slow axis. The in-plane retardation Re (550) of the first optical compensation layer 30 is 230 nm to 310 nm. In one embodiment, the Nz coefficient of the first optical compensation layer is preferably 0.1 to 0.4. In this case, the slow axis of the first optical compensation layer 30 and the absorption axis of the polarizer 10 are substantially orthogonal. In another embodiment, the Nz coefficient of the first optical compensation layer is preferably between 0.6 and 0.9. In this case, the slow axis of the first optical compensation layer 30 and the absorption axis of the polarizer 10 are substantially parallel. The second optical compensation layer 40 has a refractive index characteristic of nx> ny ≧ nz and has a slow axis. The angle formed by the slow axis of the second optical compensation layer 40 and the absorption axis of the polarizer 10 is preferably 35 ° to 55 °, more preferably 38 ° to 52 °, and still more preferably 42 ° to 48 °, particularly preferably about 45 °. When the angle is within such a range, an excellent antireflection function can be realized. The second optical compensation layer 40 satisfies the relationship of Re (450) <Re (550), and the in-plane retardation Re (550) is 100 nm to 180 nm. The third optical compensation layer 50 has a refractive index characteristic of nz> nx ≧ ny. The thickness direction retardation Rth (550) of the third optical compensation layer 50 is −260 nm to −10 nm. As described above, the first optical compensation layer having a refractive index characteristic of nx> nz> ny and having a predetermined in-plane retardation, and the refractive index characteristic of nx> ny ≧ nz, and having a predetermined in-plane A second optical compensation layer having a phase difference and exhibiting wavelength dependence of inverse dispersion; and a third optical having a refractive index characteristic of nz> nx ≧ ny and having a predetermined thickness direction phase difference By arranging the compensation layer in this order from the polarizer side, it seems that the absorption axis of the polarizer when viewed from an oblique direction is apparent while maintaining excellent antireflection characteristics in the front direction due to the excellent circular polarization function By preventing light leakage due to axial misalignment, it is possible to realize a polarizing plate with an optical compensation layer having excellent antireflection characteristics in an oblique direction.

  The polarizing plate with an optical compensation layer may be a single wafer or may be long. When the polarizing plate with an optical compensation layer is long, the polarizer 10 typically has an absorption axis in a direction substantially parallel to the long direction. The second optical compensation layer 40 typically has a slow axis in the direction of 35 ° to 55 ° with respect to the longitudinal direction.

  Hereinafter, each layer and the optical film constituting the polarizing plate with an optical compensation layer will be described in detail.

A-1. Polarizer Any appropriate polarizer may be adopted as the polarizer 10. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

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

  The dyeing with iodine is performed, for example, by immersing a PVA film in an iodine aqueous solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be performed after the dyeing treatment or may be performed while dyeing. Moreover, you may dye | stain after extending | stretching. If necessary, the PVA film is subjected to swelling treatment, crosslinking treatment, washing treatment, drying treatment and the like. For example, by immersing the PVA film in water and washing it before dyeing, not only can the surface of the PVA film be cleaned of dirt and anti-blocking agents, but the PVA film can be swollen to cause uneven staining. Can be prevented.

  As a specific example of a polarizer obtained by using a laminate, a laminate of a resin substrate and a PVA resin layer (PVA resin film) laminated on the resin substrate, or a resin substrate and the resin Examples thereof include a polarizer obtained by using a laminate with a PVA resin layer applied and formed on a substrate. For example, a polarizer obtained by using a laminate of a resin base material and a PVA resin layer applied and formed on the resin base material may be obtained by, for example, applying a PVA resin solution to a resin base material and drying it. A PVA-based resin layer is formed thereon to obtain a laminate of a resin base material and a PVA-based resin layer; the laminate is stretched and dyed to make the PVA-based resin layer a polarizer; obtain. In the present embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching. Furthermore, the stretching may further include, if necessary, stretching the laminate in the air at a high temperature (for example, 95 ° C. or higher) before stretching in the aqueous boric acid solution. The obtained resin base material / polarizer laminate may be used as it is (that is, the resin base material may be used as a protective layer of the polarizer), and the resin base material is peeled from the resin base material / polarizer laminate. Any appropriate protective layer according to the purpose may be laminated on the release surface. Details of a method for manufacturing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580. This publication is incorporated herein by reference in its entirety.

  The thickness of the polarizer is preferably 25 μm or less, more preferably 1 μm to 12 μm, still more preferably 3 μm to 12 μm, and particularly preferably 3 μm to 8 μm. When the thickness of the polarizer is in such a range, curling during heating can be satisfactorily suppressed, and good appearance durability during heating can be obtained.

  The polarizer preferably exhibits absorption dichroism at any wavelength between 380 nm and 780 nm. The single transmittance of the polarizer is preferably 42.0% to 46.0%, more preferably 44.5% to 46.0%. The polarization degree of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.

A-2. First Optical Compensation Layer As described above, the first optical compensation layer 30 has a relationship of refractive index characteristics of nx>nz> ny. The in-plane retardation Re (550) of the first optical compensation layer is 230 nm to 310 nm, preferably 240 nm to 300 nm, and more preferably 260 nm to 280 nm. If the in-plane retardation of the first optical compensation layer is in such a range, the slow axis direction of the first optical compensation layer depends on the Nz coefficient as described above with respect to the absorption axis direction of the polarizer. By making it substantially orthogonal or parallel, it is possible to prevent the deterioration of the antireflection function in the oblique direction due to the apparent axial shift of the absorption axis of the polarizer.

  In one embodiment, the Nz coefficient of the first optical compensation layer is preferably 0.1 to 0.4, more preferably 0.2 to 0.3, and still more preferably 0.23 to 0.33. 0.27. In another embodiment, the Nz coefficient is preferably 0.6 to 0.9, more preferably 0.7 to 0.8, and even more preferably 0.73 to 0.77. If the Nz coefficient is in such a range, a better oblique antireflection characteristic is achieved by adjusting the angle of the slow axis of the first optical compensation layer and the absorption axis of the polarizer to a predetermined angle. Can do.

  The first optical compensation layer may exhibit a reverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light, and has a positive chromatic dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light. It may also be possible to show a flat chromatic dispersion characteristic in which the phase difference value hardly changes depending on the wavelength of the measurement light.

The first optical compensation layer is typically a retardation film formed of any appropriate resin capable of realizing the above characteristics. Examples of the resin that forms the retardation film include polyarylate, polyamide, polyimide, polyester, polyaryletherketone, polyamideimide, polyesterimide, polyvinyl alcohol, polyfumaric acid ester, polyethersulfone, polysulfone, and norbornene resin. A polycarbonate resin, a cellulose resin, and a polyurethane are mentioned. These resins may be used alone or in combination. Polyarylate or polycarbonate resin is preferable. More preferably, it is a polycarbonate resin or a polyarylate represented by the following formula (I). The polycarbonate resin will be described later with respect to the second optical compensation layer.

In formula (I), A and B each represent a substituent, and are a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group, and A and B are the same or different. Also good. a and b represent the corresponding number of substitutions of A and B, and are integers of 1 to 4, respectively. D is a covalent bond, CH ₂ group, C (CH ₃ ) ₂ group, C (CZ ₃ ) ₂ group (where Z is a halogen atom), CO group, O atom, S atom, SO ₂ group, Si (CH ₂ CH ₃ ) ₂ groups and N (CH ₃ ) groups. R1 is a linear or branched alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group. R2 is a linear or branched alkyl group having 2 to 10 carbon atoms, or a substituted or unsubstituted aryl group. R3, R4, R5 and R6 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R3, R4, R5 and R6 may be the same or different. p1 is an integer of 0 to 3, p2 is an integer of 1 to 3, and n is an integer of 2 or more.

  The first optical compensation layer can be formed, for example, by applying a coating solution obtained by dissolving or dispersing the resin in any appropriate solvent to a shrinkable film to form a coating film, and then shrinking the coating film. . Typically, in the contraction of the coating film, the laminate of the contractible film and the coating film is heated to contract the contractible film, and the contraction of the contractible film causes the coating film to contract. The shrinkage ratio of the coating film is preferably 0.50 to 0.99, more preferably 0.60 to 0.98, and still more preferably 0.70 to 0.95. The heating temperature is preferably 130 ° C to 170 ° C, more preferably 150 ° C to 160 ° C. In one embodiment, when shrinking a coating film, a layered product may be extended in the direction orthogonal to the shrinkage direction. In this case, the draw ratio of the laminate is preferably 1.01 to 3.0 times, more preferably 1.05 to 2.0 times, and even more preferably 1.10 times to 1.50. Is double. Specific examples of the material constituting the shrinkable film include polyolefin, polyester, acrylic resin, polyamide, polycarbonate, norbornene resin, polystyrene, polyvinyl chloride, polyvinylidene chloride, cellulose resin, polyethersulfone, polysulfone, polyimide, polyacrylic. , Acetate resin, polyarylate, polyvinyl alcohol, and liquid crystal polymer. These may be used alone or in combination. The shrinkable film is preferably a stretched film formed from these materials.

  The thickness of the first optical compensation layer is preferably 10 μm to 150 μm, more preferably 10 μm to 50 μm, and still more preferably 10 μm to 30 μm. With such a thickness, the desired in-plane retardation and Nz coefficient can be obtained.

A-3. Second Optical Compensation Layer As described above, the second optical compensation layer 40 has a relationship in refractive index characteristics of nx> ny ≧ nz. The in-plane retardation Re (550) of the second optical compensation layer is 100 nm to 180 nm, preferably 110 nm to 170 nm, and more preferably 120 nm to 160 nm. If the in-plane retardation of the second optical compensation layer is within such a range, the slow axis direction of the second optical compensation layer is set to 35 ° to 55 ° as described above with respect to the absorption axis direction of the polarizer. By setting the angle to be (especially about 45 °), an excellent antireflection function can be realized.

  The second optical compensation layer typically exhibits reverse dispersion wavelength characteristics. Specifically, the in-plane retardation satisfies the relationship Re (450) <Re (550). By satisfying such a relationship, an excellent reflection hue can be achieved. Re (450) / Re (550) is preferably 0.8 or more and less than 1, and more preferably 0.8 or more and 0.95 or less.

  The Nz coefficient of the second optical compensation layer is preferably 1.0 to 2.0, more preferably 1.0 to 1.5, and still more preferably 1.0 to 1.3. By satisfying such a relationship, a more excellent reflection hue can be achieved.

  The water absorption rate of the second optical compensation layer is preferably 3% or less, more preferably 2.5% or less, and further preferably 2% or less. By satisfying such a water absorption rate, it is possible to suppress changes in display characteristics over time. In addition, a water absorption rate can be calculated | required based on JISK7209.

  The second optical compensation layer is typically a retardation film formed of any appropriate resin capable of realizing the above characteristics. As the resin for forming the retardation film, a polycarbonate resin is preferably used.

  Any appropriate polycarbonate resin can be used as the polycarbonate resin as long as the effects of the present invention can be obtained. Preferably, the polycarbonate resin includes a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, an alicyclic diol, an alicyclic dimethanol, di, tri, or polyethylene glycol, and an alkylene. A structural unit derived from at least one dihydroxy compound selected from the group consisting of glycol or spiroglycol. Preferably, the polycarbonate resin is derived from a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, a structural unit derived from an alicyclic dimethanol and / or a di-, tri- or polyethylene glycol. More preferably, a structural unit derived from a fluorene-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 resin may contain structural units derived from other dihydroxy compounds as necessary. The details of the polycarbonate resin that can be suitably used in the present invention are described in, for example, Japanese Patent Application Laid-Open Nos. 2014-10291 and 2014-26266, and the description is incorporated herein by reference. The

  The glass transition temperature of the polycarbonate resin is preferably 110 ° C. or higher and 180 ° C. or lower, more preferably 120 ° C. or higher and 165 ° C. or lower. If the glass transition temperature is excessively low, the heat resistance tends to deteriorate, there is a possibility of causing a dimensional change after film formation, and the image quality of the resulting organic EL panel may be lowered. If the glass transition temperature is excessively high, the molding stability at the time of film molding may deteriorate, and the transparency of the film may be impaired. The glass transition temperature is determined according to JIS K 7121 (1987).

  The molecular weight of the polycarbonate resin can be represented by a reduced viscosity. The reduced viscosity is measured using a Ubbelohde viscometer at a temperature of 20.0 ° C. ± 0.1 ° C., using methylene chloride as a solvent, precisely adjusting the polycarbonate concentration to 0.6 g / dL. The lower limit of the reduced viscosity is usually preferably 0.30 dL / g, more preferably 0.35 dL / g or more. The upper limit of the reduced viscosity is usually preferably 1.20 dL / g, more preferably 1.00 dL / g, still more preferably 0.80 dL / g. If the reduced viscosity is less than the lower limit, there may be a problem that the mechanical strength of the molded product is reduced. On the other hand, if the reduced viscosity is larger than the upper limit, the fluidity at the time of molding is lowered, and there may be a problem that productivity and moldability are lowered.

  The retardation film is typically produced by stretching a resin film in at least one direction.

  Any appropriate method can be adopted as a method of forming the resin film. For example, a melt extrusion method (for example, a T-die molding method), a cast coating method (for example, a casting method), a calendar molding method, a hot press method, a co-extrusion method, a co-melting method, a multilayer extrusion method, an inflation molding method, etc. It is done. Preferably, a T-die molding method, a casting method, and an inflation molding method are used.

  The thickness of the resin film (unstretched film) can be set to any appropriate value depending on desired optical characteristics, stretching conditions described later, and the like. Preferably it is 50 micrometers-300 micrometers.

  Any appropriate stretching method and stretching conditions (for example, stretching temperature, stretching ratio, stretching direction) can be adopted for the stretching. Specifically, various stretching methods such as free end stretching, fixed end stretching, free end contraction, and fixed end contraction can be used singly or simultaneously or sequentially. The stretching direction can also be performed in various directions and dimensions such as a horizontal direction, a vertical direction, a thickness direction, and a diagonal direction. The stretching temperature is preferably Tg-30 ° C to Tg + 60 ° C, and more preferably Tg-10 ° C to Tg + 50 ° C, with respect to the glass transition temperature (Tg) of the resin film.

  By appropriately selecting the stretching method and stretching conditions, a retardation film having the desired optical characteristics (for example, refractive index characteristics, in-plane retardation, Nz coefficient) can be obtained.

  In one embodiment, the retardation film is produced by continuously stretching a long resin film obliquely in the direction of an angle θ with respect to the longitudinal direction. By adopting oblique stretching, a long stretched film having an orientation angle of θ with respect to the longitudinal direction of the film (slow axis in the direction of angle θ) can be obtained. For example, when laminating with a polarizer Roll-to-roll is possible, and the manufacturing process can be simplified. Since the absorption axis of the polarizer appears in the longitudinal direction or the width direction of the long film due to the manufacturing method thereof, the angle θ is the absorption axis of the polarizer and the slow axis of the second optical compensation layer. It can be an angle between

  Examples of the stretching machine used for the oblique stretching include a tenter-type stretching machine that can apply a feeding force, a pulling force, or a pulling force at different speeds in the lateral and / or longitudinal direction. The tenter type stretching machine includes a horizontal uniaxial stretching machine, a simultaneous biaxial stretching machine, and the like, but any suitable stretching machine can be used as long as a long resin film can be continuously stretched obliquely.

  The thickness of the retardation film (stretched film, that is, the second optical compensation layer) is preferably 20 μm to 100 μm, more preferably 20 μm to 80 μm, and still more preferably 20 μm to 65 μm. With such a thickness, the desired in-plane retardation and thickness direction retardation can be obtained.

A-4. Third Optical Compensation Layer As described above, the third optical compensation layer 50 has a relationship in which the refractive index characteristic is nz> nx ≧ ny. The thickness direction retardation Rth (550) of the third optical compensation layer is preferably −260 nm to −10 nm, more preferably −230 nm to −15 nm, and still more preferably −215 nm to −20 nm. By providing the third optical compensation layer having such optical characteristics, the reflection hue when viewed from an oblique direction is remarkably improved, and as a result, the polarization with an optical compensation layer having very excellent viewing angle characteristics. A plate can be obtained.

  In one embodiment, the third optical compensation layer has a refractive index of nx = ny. Here, “nx = ny” includes not only the case where nx and ny are exactly equal, but also the case where nx and ny are substantially equal. Specifically, Re (550) is less than 10 nm. In another embodiment, the third optical compensation layer has a refractive index relationship of nx> ny. Therefore, the third optical compensation layer may have a slow axis. The slow axis of the third optical compensation layer is substantially orthogonal or parallel to the absorption axis of the polarizer. The in-plane retardation Re (550) of the third optical compensation layer is preferably 10 nm to 150 nm, and more preferably 10 nm to 80 nm.

  The third optical compensation layer can be formed of any appropriate material. A liquid crystal layer fixed in homeotropic alignment is preferable. The liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the liquid crystal layer include the liquid crystal compounds and methods described in JP-A-2002-333642, [0020] to [0042]. In this case, the thickness is preferably 0.1 μm to 5 μm, more preferably 0.2 μm to 3 μm.

  As another preferred specific example, the third optical compensation layer may be a retardation film formed of a fumaric acid diester resin described in JP 2012-32784 A. In this case, the thickness is preferably 5 μm to 80 μm, more preferably 10 μm to 50 μm.

A-5. Protective layer The protective layer 20 is formed of any suitable film that can be used as a protective layer for a polarizer. Specific examples of the material as the main component of the film include cellulose resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and polysulfone-based materials. And transparent resins such as polystyrene, polynorbornene, polyolefin, (meth) acryl, and acetate. Further, thermosetting resins such as (meth) acrylic, urethane-based, (meth) acrylurethane-based, epoxy-based, and silicone-based or ultraviolet curable resins are also included. In addition to this, for example, a glassy polymer such as a siloxane polymer is also included. Moreover, the polymer film as described in Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007) can also be used. As a material for this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in the side chain For example, a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile / styrene copolymer can be mentioned. The polymer film can be, for example, an extruded product of the resin composition.

  The protective layer 20 may be subjected to surface treatment such as hard coat treatment, antireflection treatment, antisticking treatment, and antiglare treatment as necessary. Further / or, if necessary, the protective layer 20 may be treated to improve visibility when viewed through polarized sunglasses (typically, an (elliptical) circular polarization function is imparted, an ultrahigh phase difference is provided. May be applied). By performing such processing, excellent visibility can be achieved even when the display screen is viewed through a polarizing lens such as polarized sunglasses. Therefore, the polarizing plate with an optical compensation layer can be suitably applied to an image display device that can be used outdoors.

  The thickness of the protective layer 20 is typically 5 mm or less, preferably 1 mm or less, more preferably 1 μm to 500 μm, and even more preferably 5 μm to 150 μm. In addition, when the surface treatment is performed, the thickness of the protective layer is a thickness including the thickness of the surface treatment layer.

  When an inner protective layer is provided between the polarizer 10 and the first optical compensation layer 30, the inner protective layer is preferably optically isotropic. In this specification, “optically isotropic” means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is −10 nm to +10 nm. Say. The inner protective layer can be composed of any suitable material as long as it is optically isotropic. The material may be appropriately selected from the materials described above for the protective layer 20, for example.

  The thickness of the inner protective layer is preferably 5 μm to 200 μm, more preferably 10 μm to 100 μm, and still more preferably 15 μm to 95 μm.

A-6. Conductive layer or conductive layer with substrate The conductive layer can be formed on any suitable substrate by any suitable film formation method (eg, vacuum deposition, sputtering, CVD, ion plating, spraying, etc.). Further, it can be formed by forming a metal oxide film. After film formation, heat treatment (for example, 100 ° C. to 200 ° C.) may be performed as necessary. By performing the heat treatment, the amorphous film can be crystallized. Examples of the metal oxide include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. The indium oxide may be doped with divalent metal ions or tetravalent metal ions. Indium composite oxide is preferable, and indium-tin composite oxide (ITO) is more preferable. The indium-based composite oxide has characteristics that it has a high transmittance (for example, 80% or more) in the visible light region (380 nm to 780 nm) and a low surface resistance value per unit area.

  When the conductive layer contains a metal oxide, the thickness of the conductive layer is preferably 50 nm or less, more preferably 35 nm or less. The lower limit of the thickness of the conductive layer is preferably 10 nm.

  The surface resistance value of the conductive layer is preferably 300Ω / □ or less, more preferably 150Ω / □ or less, and further preferably 100Ω / □ or less.

  The conductive layer may be transferred from the base material to the third optical compensation layer, and the conductive layer alone may be used as a constituent layer of the polarizing plate with an optical compensation layer, or a laminate with the base material (conductive layer with base material). May be laminated on the third optical compensation layer. Typically, as described above, the conductive layer and the base material can be introduced into the polarizing plate with an optical compensation layer as a conductive layer with a base material.

  Arbitrary appropriate resin is mentioned as a material which comprises a base material. Preferably, it is resin excellent in transparency. Specific examples include cyclic olefin resins, polycarbonate resins, cellulose resins, polyester resins, and acrylic resins.

  Preferably, the substrate is optically isotropic, and therefore the conductive layer can be used as a conductive layer with an isotropic substrate in a polarizing plate with an optical compensation layer. Examples of the material constituting the optically isotropic substrate (isotropic substrate) include, for example, a material having a main skeleton such as a norbornene-based resin or an olefin-based resin, a lactone ring, or glutar Examples thereof include materials having a cyclic structure such as an imide ring in the main chain of the acrylic resin. When such a material is used, when an isotropic substrate is formed, it is possible to suppress the expression of the phase difference accompanying the orientation of the molecular chain.

  The thickness of the substrate is preferably 10 μm to 200 μm, more preferably 20 μm to 60 μm.

A-7. Others Arbitrary appropriate pressure-sensitive adhesive layers or adhesive layers are used for laminating the layers constituting the polarizing plate with an optical compensation layer of the present invention. The pressure-sensitive adhesive layer is typically formed of an acrylic pressure-sensitive adhesive. The adhesive layer is typically formed of a polyvinyl alcohol-based adhesive.

  Although not shown, an adhesive layer may be provided on the third optical compensation layer 50 side of the polarizing plate 100 with an optical compensation layer. By providing the pressure-sensitive adhesive layer in advance, it can be easily bonded to another optical member (for example, an organic EL cell). In addition, it is preferable that the peeling film is bonded together on the surface of this adhesive layer until it uses.

B. Organic EL Panel The organic EL panel of the present invention includes an organic EL cell and the polarizing plate with an optical compensation layer described in the above section A on the viewing side of the organic EL cell. The polarizing plate with an optical compensation layer is laminated so that the third optical compensation layer is on the organic EL cell side (so that the polarizer is on the viewing side).

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. In addition, the measuring method of each characteristic is as follows.

(1) Thickness The thickness was measured using a dial gauge (manufactured by PEACOCK, product name “DG-205”, dial gauge stand (product name “pds-2”)).
(2) Retardation A 50 mm × 50 mm sample was cut out from each optical compensation layer to obtain a measurement sample, and measurement was performed using Axoscan manufactured by Axometrics. The measurement wavelength was 450 nm, 550 nm, and the measurement temperature was 23 ° C.
Moreover, the average refractive index was measured using an Abbe refractometer manufactured by Atago Co., Ltd., and the refractive indexes nx, ny, and nz were calculated from the obtained retardation values.
(3) Reflection characteristics in oblique direction Simulation was performed using the characteristics of the polarizing plate with an optical compensation layer obtained in Examples and Comparative Examples. The front direction (polar angle 0 °) and the oblique direction (polar angle 60 °) were evaluated. For the simulation, “LCD MASTER Ver. 6.084” manufactured by Shintech Co., Ltd. was used. The reflection characteristics were simulated using the extended function of LCD Master. More specifically, the front reflection intensity, the front reflection hue, the oblique reflection intensity, and the oblique hue were evaluated. The oblique reflection intensity was evaluated as an average value of four points of polar angle 60 °, azimuth angle 45 °, 135 °, 225 ° and 315 °. The front reflection hue was evaluated as Δu′v ′ (neutral) from the neutral point, and the oblique hue was evaluated as a color shift Δu′v ′ at a polar angle of 60 ° and an azimuth angle of 0 ° to 360 °.

[Example 1]
(I) Preparation of first optical compensation layer (i-1) Synthesis of polyarylate In a reaction vessel equipped with a stirrer, 27.0 kg of 2,2-bis (4-hydroxyphenyl) -4-methylpentane and Tetrabutylammonium chloride 0.8 kg was dissolved in 250 L of sodium hydroxide solution. To this solution, a solution prepared by dissolving 13.5 kg of terephthalic acid chloride and 6.30 kg of isophthalic acid chloride in 300 L of toluene was added at a time while stirring, and stirred at room temperature for 90 minutes to obtain a polycondensation solution. Thereafter, the polycondensation solution was allowed to stand and separate to separate a toluene solution containing polyarylate. Next, the separation liquid was washed with acetic acid water and further washed with ion exchange water, and then poured into methanol to precipitate polyarylate. The precipitated polyarylate was filtered and dried under reduced pressure to obtain 34.1 kg of white polyarylate (yield 92%).

(I-2) Production of Retardation Layer 10 kg of the polyarylate obtained above was dissolved in 73 kg of toluene to prepare a coating solution. Thereafter, the coating solution is directly applied onto a shrinkable film (longitudinal uniaxially stretched polypropylene film, manufactured by Tokyo Ink Co., Ltd., trade name “Noblen”), and the coating film is dried at a temperature of 60 ° C. for 5 minutes. And dried at 80 ° C. for 5 minutes to form a shrinkable film / birefringent layer laminate. Using the simultaneous biaxial stretching machine, the obtained laminate is stretched at a stretching temperature of 155 ° C. to a shrinkage ratio of 0.70 in the MD direction and 1.15 times in the TD direction to form a retardation film on the shrinkable film. Formed. Next, the retardation film was peeled from the shrinkable film. The thickness of the retardation film was 15.0 μm, Re (550) = 272 nm, and Nz = 0.25. This retardation film was used as the first optical compensation layer.

(Ii) Production of Second Optical Compensation Layer (ii-1) Production of Polycarbonate Resin Film Using a batch polymerization apparatus comprising two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100 ° C. Polymerization was performed. 9,9- [4- (2-hydroxyethoxy) phenyl] fluorene (BHEPF), isosorbide (ISB), diethylene glycol (DEG), diphenyl carbonate (DPC), and magnesium acetate tetrahydrate in a molar ratio of BHEPF / ISB / DEG / DPC / magnesium acetate = 0.348 / 0.490 / 0.162 / 1.005 / 1.00 × 10 ⁻⁵ was charged. After sufficiently replacing the inside of the reactor with nitrogen (oxygen concentration 0.0005 to 0.001 vol%), heating was performed with a heating medium, and stirring was started when the internal temperature reached 100 ° C. After 40 minutes from the start of temperature increase, the internal temperature was reached to 220 ° C., and control was performed so as to maintain this temperature. At the same time, pressure reduction was started, and after reaching 220 ° C., 13.3 kPa was reached in 90 minutes. The phenol vapor produced as a by-product with the polymerization reaction was led to a reflux condenser at 100 ° C., and a monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the phenol vapor not condensed was led to a condenser at 45 ° C. and recovered.

  Nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, and then the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Subsequently, the temperature increase and pressure reduction in the second reactor were started, and the internal temperature was 240 ° C. and the pressure was 0.2 kPa in 50 minutes. Thereafter, polymerization was allowed to proceed until a predetermined stirring power was obtained. When a predetermined power is reached, nitrogen is introduced into the reactor, the pressure is restored, the reaction solution is withdrawn in the form of a strand, pelletized with a rotary cutter, and BHEPF / ISB / DEG = 34.8 / 49.0 / A polycarbonate resin having a copolymer composition of 16.2 [mol%] was obtained. This polycarbonate resin had a reduced viscosity of 0.430 dL / g and a glass transition temperature of 128 ° C.

(Ii-2) Preparation of retardation film The obtained polycarbonate resin was vacuum-dried at 80 ° C for 5 hours, and then a single-screw extruder (manufactured by Isuzu Chemical Industries, screw diameter 25 mm, cylinder setting temperature: 220 ° C), A polycarbonate resin film having a thickness of 130 μm was prepared using a film forming apparatus equipped with a T die (width 900 mm, set temperature: 220 ° C.), a chill roll (set temperature: 125 ° C.), and a winder. The polycarbonate resin film obtained had a water absorption rate of 1.2%.

  The polycarbonate resin film obtained as described above was obliquely stretched by a method in accordance with Example 1 of JP-A No. 2014-19483 to obtain a retardation film.

  The specific production procedure of the retardation film is as follows: A polycarbonate resin film (thickness 130 μm, width 765 mm) was preheated to 142 ° C. in the preheating zone of the stretching apparatus. In the preheating zone, the clip pitch of the left and right clips was 125 mm. Next, as soon as the film entered the first oblique stretching zone C1, the clip pitch of the right clip began to increase and increased from 125 mm to 177.5 mm in the first oblique stretching zone C1. The clip pitch change rate was 1.42. In the first oblique stretching zone C1, the clip pitch of the left clip started to decrease and decreased from 125 mm to 90 mm in the first oblique stretching zone C1. The clip pitch change rate was 0.72. Furthermore, as soon as the film entered the second oblique stretching zone C2, the clip pitch of the left clip started to increase and increased from 90 mm to 177.5 mm in the second oblique stretching zone C2. On the other hand, the clip pitch of the right clip was maintained at 177.5 mm in the second oblique stretching zone C2. Simultaneously with the oblique stretching, stretching in the width direction was performed 1.9 times. The oblique stretching was performed at 135 ° C. Next, MD shrinkage treatment was performed in the shrinkage zone. Specifically, the clip pitches of the left clip and right clip were both reduced from 177.5 mm to 165 mm. The shrinkage rate in the MD shrinkage treatment was 7.0%.

  As described above, a retardation film (thickness 40 μm) was obtained. Re (550) of the obtained retardation film is 147 nm, Rth (550) is 167 nm (nx: 1.5977, ny: 1.59404, nz: 1.5935), and the refractive index is nx> ny = nz. The characteristics are shown. Moreover, Re (450) / Re (550) of the obtained retardation film was 0.89. The slow axis direction of the retardation film was 45 ° with respect to the longitudinal direction. This retardation film was used as the second optical compensation layer.

(Iii) Production of Third Optical Compensation Layer In the following chemical formula (II) (numbers 65 and 35 in the formula indicate the mol% of the monomer unit and are represented by block polymer for convenience: weight average molecular weight 5000) 20 parts by weight of the side chain type liquid crystal polymer shown, polymerizable liquid crystal showing a nematic liquid crystal phase (manufactured by BASF: trade name: Palicolor LC242) and photopolymerization initiator (manufactured by Ciba Specialty Chemicals: trade name: Irgacure 907) 5 Part by weight was dissolved in 200 parts by weight of cyclopentanone to prepare a liquid crystal coating solution. And after apply | coating the said coating liquid to a base film (norbornene-type resin film: Nippon Zeon Co., Ltd. make, brand name "ZEONEX") with a bar coater, a liquid crystal is dried by heating at 80 degreeC for 4 minutes. Oriented. By irradiating the liquid crystal layer with ultraviolet rays and curing the liquid crystal layer, a liquid crystal solidified layer (thickness: 1.10 μm) serving as the second optical compensation layer was formed on the substrate. This layer has Re (550) of 0 nm and Rth (550) of -135 nm (nx: 1.5723, ny: 1.5723, nz: 1.5757), and exhibits a refractive index characteristic of nz> nx = ny. It was.

(Iv) Production of Laminate Roll the retardation film (first optical compensation layer) of (i) and the retardation film (second optical compensation layer) of (ii) through an acrylic pressure-sensitive adhesive. Bonding was performed by two rolls to obtain a retardation film laminate. After the liquid crystal solidified layer (third optical compensation layer) of (iii) is bonded to the second optical compensation layer of the retardation film laminate by roll-to-roll through an acrylic adhesive, the base The material film was peeled and removed to obtain a laminate of the first optical compensation layer / second optical compensation layer / third optical compensation layer.

(V) Production of polarizer A long roll of polyvinyl alcohol (PVA) resin film (product name “PE3000”, manufactured by Kuraray Co., Ltd.) having a thickness of 30 μm is longitudinally stretched 5.9 times in the longitudinal direction by a roll stretching machine. While being uniaxially stretched in the direction, swelling, dyeing, crosslinking, and washing treatment were simultaneously performed, and finally, a drying treatment was performed to produce a polarizer having a thickness of 12 μm.
Specifically, the swelling treatment was stretched 2.2 times while being treated with pure water at 20 ° C. Next, the dyeing treatment is performed in an aqueous solution at 30 ° C. in which the weight ratio of iodine and potassium iodide is 1: 7, the iodine concentration of which is adjusted so that the single transmittance of the obtained polarizer is 45.0%. The film was stretched 1.4 times. Furthermore, the crosslinking treatment employed a two-stage crosslinking treatment, and the first-stage crosslinking treatment was stretched 1.2 times while being treated in an aqueous solution in which boric acid and potassium iodide were dissolved at 40 ° C. The boric acid content of the aqueous solution of the first-stage crosslinking treatment was 5.0% by weight, and the potassium iodide content was 3.0% by weight. The cross-linking treatment at the second stage was stretched 1.6 times while being treated in an aqueous solution in which boric acid and potassium iodide were dissolved at 65 ° C. The boric acid content of the aqueous solution of the second crosslinking treatment was 4.3% by weight, and the potassium iodide content was 5.0% by weight. In addition, the cleaning treatment was performed with an aqueous potassium iodide solution at 20 ° C. The potassium iodide content of the aqueous solution for the washing treatment was 2.6% by weight. Finally, the drying process was performed at 70 ° C. for 5 minutes to obtain a polarizer.

(Vi) Production of polarizing plate HC-TAC film (thickness: having a hard coat (HC) layer formed on one side of the TAC film by a hard coat treatment on one side of the polarizer via a polyvinyl alcohol-based adhesive. 32 μm, corresponding to the protective layer) was bonded by roll-to-roll to obtain a long polarizing plate having a protective layer / polarizer configuration.

(Vii) Production of polarizing plate with optical compensation layer Laminate of polarizer surface of polarizing plate obtained above and first optical compensation layer / second optical compensation layer / third optical compensation layer obtained above The first optical compensation layer surface of the body is bonded via an acrylic adhesive, and the structure of the protective layer / polarizer / first optical compensation layer / second optical compensation layer / third optical compensation layer is formed. A long polarizing plate with an optical compensation layer was obtained. At this time, an angle formed between the absorption axis of the polarizer and the slow axis of the second optical compensation layer so that the absorption axis of the polarizer and the slow axis of the first optical compensation layer are substantially orthogonal to each other. Was laminated so that the angle was 45 °.

(Viii) Preparation of organic EL panel An adhesive layer was formed with an acrylic adhesive on the third optical compensation layer side of the obtained polarizing plate with an optical compensation layer, and cut into dimensions of 50 mm x 50 mm.
A smartphone (Galaxy-S5) manufactured by Samsung Radio Co., Ltd. was disassembled and the organic EL panel was taken out. The polarizing film affixed to this organic EL panel was peeled off, and the polarizing plate with an optical compensation layer cut out above was bonded together to obtain an organic EL panel.

  Using the characteristics of the obtained polarizing plate with an optical compensation layer, the reflection characteristics (3) were simulated. The results are shown in Table 1.

[Example 2]
The retardation film of polycarbonate resin obtained as described below was used as the first optical compensation layer, and the absorption axis of the polarizer and the slow axis of the first optical compensation layer were substantially parallel. Optical compensation having the configuration of protective layer / polarizer / second optical compensation layer / second optical compensation layer / third optical compensation layer in the same manner as in Example 1 except that the layers were bonded to each other. A polarizing plate with a layer was obtained. Furthermore, an organic EL panel was produced in the same manner as in Example 1 except that this polarizing plate with an optical compensation layer was used. The obtained polarizing plate with an optical compensation layer and the organic EL panel were subjected to the same evaluation as in Example 1. The results are shown in Table 1.

  Phosgene as a carbonate precursor, (A) 2,2-bis (4-hydroxyphenyl) propane as an aromatic dihydric phenol component, and (B) 1,1-bis (4-hydroxyphenyl) -3,3,5- Using trimethylcyclohexane, a repeating unit of the following formulas (3) and (4) having a weight ratio of (A) :( B) of 4: 6 and a weight average molecular weight (Mw) of 60,000 according to a conventional method Polycarbonate resin [number average molecular weight (Mn) = 33,000, Mw / Mn = 1.78] was obtained. 70 parts by weight of the above polycarbonate resin and 30 parts by weight of a styrene resin having a weight average molecular weight (Mw) of 1,300 [number average molecular weight (Mn) = 716, Mw / Mn = 1.78] (Sanyo Kasei Heimer SB75) Was added to 300 parts by weight of dichloromethane and stirred and mixed at room temperature for 4 hours to obtain a transparent solution. This solution was cast on a glass plate, allowed to stand at room temperature for 15 minutes, peeled off from the glass plate, dried in an oven at 80 ° C. for 10 minutes, and then at 120 ° C. for 20 minutes, and had a thickness of 36 μm and a glass transition temperature (Tg ) Obtained a polymer film of 140 ° C. The polymer film obtained had a light transmittance of 93% at a wavelength of 590 nm. The in-plane retardation value of the polymer film: Re (590) was 5.0 nm, and the retardation value in the thickness direction: Rth (590) was 12.0 nm. The average refractive index was 1.576.

  On both sides of the polymer film (thickness: 36 μm), a biaxially stretched polypropylene film [manufactured by Toray, trade name “Trephan” (thickness: 60 μm)] was bonded via an acrylic pressure-sensitive adhesive layer (thickness: 15 μm). Then, the longitudinal direction of the film was held with a roll stretching machine, and the film was stretched 1.49 times in an air circulation type thermostatic oven at 147 ° C. The obtained retardation film had a thickness of 40 μm, Re (550) = 270 nm, and Nz = 0.75.

[Comparative Example 1]
Polarized light with optical compensation layer having the configuration of protective layer / polarizer / second optical compensation layer / third optical compensation layer in the same manner as in Example 1 except that the first optical compensation layer was not laminated. I got a plate. Furthermore, an organic EL panel was produced in the same manner as in Example 1 except that this polarizing plate with an optical compensation layer was used. The obtained polarizing plate with an optical compensation layer and the organic EL panel were subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[Evaluation]
As is clear from Table 1, the polarizing plate with an optical compensation layer of the example of the present invention can have excellent antireflection characteristics in the oblique direction while maintaining excellent antireflection characteristics in the front direction. .

  The polarizing plate with an optical compensation layer of the present invention is suitably used for an organic EL panel.

DESCRIPTION OF SYMBOLS 10 Polarizer 20 Protective layer 30 1st optical compensation layer 40 2nd optical compensation layer 50 3rd optical compensation layer 100 Polarizing plate with an optical compensation layer

Claims (5)

A polarizer, a first optical compensation layer, a second optical compensation layer, and a third optical compensation layer;
The first optical compensation layer exhibits a refractive index characteristic of nx>nz> ny, Re (550) is 230 nm to 310 nm,
The second optical compensation layer exhibits refractive index characteristics of nx> ny ≧ nz, Re (550) is 100 nm to 180 nm, and satisfies the relationship of Re (450) <Re (550),
The third optical compensation layer exhibits a refractive index characteristic of nz> nx ≧ ny, Rth (550) is −260 nm to −10 nm,
Used for organic EL panels,
Polarizing plate with optical compensation layer:
Here, Re (450) and Re (550) represent in-plane retardation measured with light having a wavelength of 450 nm and 550 nm at 23 ° C., respectively, and Rth (550) is measured with light having a wavelength of 550 nm at 23 ° C. Represents the retardation in the thickness direction.   The Nz coefficient of the first optical compensation layer is 0.1 to 0.4, and the absorption axis direction of the polarizer and the slow axis direction of the first optical compensation layer are substantially orthogonal to each other. The polarizing plate with an optical compensation layer according to claim 1, wherein an angle formed between the absorption axis of the polarizer and the slow axis of the second optical compensation layer is 35 ° to 55 °.   The Nz coefficient of the first optical compensation layer is 0.6 to 0.9, and the absorption axis direction of the polarizer and the slow axis direction of the first optical compensation layer are substantially parallel; The polarizing plate with an optical compensation layer according to claim 1, wherein an angle formed between the absorption axis of the polarizer and the slow axis of the second optical compensation layer is 35 ° to 55 °. A long polarizing plate with an optical compensation layer,
The polarizing plate with an optical compensation layer according to claim 1, wherein the second optical compensation layer has a slow axis in a direction of 35 ° to 55 ° with respect to the longitudinal direction. An organic EL panel comprising the polarizing plate with an optical compensation layer according to claim 1.

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