JP2019197181A - Polarizing plate and display device - Google Patents

Abstract

To provide a circularly polarizing plate with a retardation film, which reduces a change of a reflective hue even after being put in a high temperature environment.SOLUTION: A circularly polarizing plate includes a polarizing plate and a retardation film. The retardation film includes a retardation layer with positive birefringence. The polarizing plate includes: a polarizer with a thickness of 15 μm or less; and protective films on both faces of the polarizer. The protective film between the polarizer and the retardation film is a non-oriented film with negative birefringence.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polarizing plate and a display device.

  In recent years, image display devices typified by organic electroluminescence (hereinafter also referred to as organic EL) display devices have been rapidly spread. In the organic EL display device, a circularly polarizing plate including a polarizer and a retardation film (λ / 4 plate) is mounted. By arranging the circularly polarizing plate, reflection of external light can be prevented and the visibility of the screen can be improved.

  With the rise of organic EL display devices, as the demand for thinner image display devices becomes stronger, thinner circular polarizing plates are also required. Changing from a retardation film obtained by molding a conventional resin film to a retardation film formed using a liquid crystal compound that can be thinned has been studied (for example, see Patent Document 1). When the circularly polarizing plate having the retardation film is placed in a high temperature environment, there is a problem that the hue of the circularly polarizing plate changes from the initial state to blue or red. Specifically, when the circularly polarizing plate is rectangular, the reflected hues near the four edges of the circularly polarizing plate may change to blue or red, respectively.

JP 2017-54093 A

  An object of the present invention is to solve the above-described problem, and to provide a circularly polarizing plate having a retardation film, which has a small in-plane change in reflected hue even after being placed in a high temperature environment. That is.

[1] A circularly polarizing plate having a polarizing plate and a retardation film,
The retardation film includes a retardation layer having positive birefringence,
The polarizing plate includes a polarizer having a thickness of 15 μm or less, and has protective films on both sides of the polarizer, and the protective film between the polarizer and the retardation film has negative birefringence. A circularly polarizing plate, which is a non-oriented film.
[2] The circularly polarizing plate according to [1], wherein the non-oriented film having negative birefringence includes at least one selected from the group consisting of (meth) acrylic resins, polystyrene resins, and maleimide resins. .
[3] The circularly polarizing plate according to [1] or [2], wherein an in-plane retardation value of the non-oriented film having negative birefringence is 10 nm or less.
[4] The circularly polarizing plate according to any one of [1] to [3], wherein the retardation layer is a layer obtained by curing a polymerizable liquid crystal compound.
[5] A display device in which the circularly polarizing plate according to any one of [1] to [4] is laminated on a display element.

  ADVANTAGE OF THE INVENTION According to this invention, it is a circularly-polarizing plate provided with retardation film, Comprising: Even after putting in a high temperature environment, a circularly-polarizing plate with a small in-plane change of a reflective hue can be provided.

It is an example of the schematic sectional drawing which shows the layer structure of a circularly-polarizing plate. It is an example of the schematic sectional drawing which shows the layer structure of an organic electroluminescence display. It is a top view of the sample for evaluation.

(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 (that is, the slow axis direction),
“Ny” is the direction perpendicular to the slow axis in the plane, and “nz” is the refractive index in the thickness direction.
(2) In-plane retardation value An in-plane retardation value (Re [λ]) refers to an in-plane retardation value at 23 ° C. and a wavelength λ (nm). Re [λ] is Re [λ] = when the film thickness is d (nm)
It is calculated by (nx−ny) × d.
(3) Thickness direction retardation value Thickness direction retardation value (Rth [λ]) refers to a retardation value in the thickness direction of the film at 23 ° C. and wavelength λ (nm). Rth [λ] is determined by Rth [λ] = ((nx + ny) / 2−nz) × d, where d (nm) is the thickness of the film.
(4) Non-oriented film The non-oriented film used in the present invention is a film satisfying an in-plane retardation value Re [590] of 10 nm or less at a wavelength of 590 nm. Furthermore, it is preferable that the retardation value Rth [590] in the thickness direction satisfy 15 nm or less because color change during the heat resistance test can be remarkably suppressed.

<Circularly polarizing plate>
The circularly polarizing plate of the present invention includes a polarizing plate and a retardation film. The polarizing plate and the retardation film can be laminated, for example, via an adhesive layer. As an adhesive layer, the below-mentioned adhesive layer and adhesive layer are mentioned, for example. In this invention, a polarizing plate means the laminated body which consists of a polarizer and the protective film bonded on both surfaces of the polarizer.

  Hereinafter, an example of the layer configuration of the circularly polarizing plate of the present invention will be described with reference to FIG. In addition, the adhesive bond layer for bonding the polarizer 10 and the protective films 11 and 12 in FIG. 1 is not shown in figure. In the circularly polarizing plate 100 shown in FIG. 1A, the first protective film 11 is laminated on one surface of the polarizer 10, and the second protective film 12 is laminated on the other surface of the polarizer 10. The polarizing plate 1 and the retardation film 2 including the layer 20 in which the polymerizable liquid crystal compound is cured have a layer structure in which the pressure-sensitive adhesive layer 13 is interposed therebetween. Further, the circularly polarizing plate 100 has an adhesive layer 14 on the surface of the retardation film 2 opposite to the polarizing plate 1. The pressure-sensitive adhesive layer 14 can be a pressure-sensitive adhesive layer for bonding to an organic EL display element or the like.

  In the circularly polarizing plate 101 shown in FIG. 1B, the first protective film 11 is laminated on one surface of the polarizer 10, and the second protective film 12 is laminated on the other surface of the polarizer 10. The polarizing plate 1 and the retardation film 2 have a layer structure in which the pressure-sensitive adhesive layer 13 is laminated. In the circularly polarizing plate 101, the retardation film 2 has a layer configuration in which a layer 20 in which a polymerizable liquid crystal compound is cured and a layer 21 in which the polymerizable liquid crystal compound is cured are laminated via an adhesive layer 15. Further, the circularly polarizing plate 101 has an adhesive layer 14 on the surface of the retardation film 2 opposite to the polarizing plate 1. The pressure-sensitive adhesive layer 14 can be a pressure-sensitive adhesive layer for bonding to an organic EL display element or the like.

  As shown in FIG. 1, the retardation film may have one retardation layer or two or more layers. Further, the retardation film may have an alignment film for aligning the polymerizable liquid crystal compound in the production stage.

  The circularly polarizing plate can have layers other than those shown in FIG. Examples of the layer that the circularly polarizing plate may further include a front plate and a light shielding pattern. The front plate can be disposed on the opposite side of the polarizing plate on which the retardation film is laminated.

  The light shielding pattern can be formed on the surface of the front plate on the polarizing plate side. The light shielding pattern is formed on the frame (non-display area) of the image display device, and the wiring of the image display device can be prevented from being visually recognized by the user.

  The shape of the main surface of the circularly polarizing plate can be substantially rectangular. The main surface means the surface having the widest area corresponding to the display surface. The term “substantially rectangular” refers to a shape that is cut or rounded so that at least one corner of the four corners (corners) is obtuse, or an end surface that is perpendicular to the main surface. A hollow part that has a recess (notch) that is partially recessed in the in-plane direction, or a part of the main surface that is hollowed into a shape such as a circle, ellipse, polygon, or a combination thereof. That you may have.

  The size of the circularly polarizing plate is not particularly limited. When the circularly polarizing plate is substantially rectangular, the length of the long side is preferably 6 cm or more and 35 cm or less, more preferably 10 cm or more and 30 cm or less, and the length of the short side is 5 cm or more and 30 cm or less. It is preferable that it is 6 cm or more and 25 cm or less.

<Polarizing plate>
In this invention, a polarizing plate means the laminated body which consists of a polarizer and the protective film bonded on both surfaces of the polarizer. The protective film provided in the polarizing plate may have a surface treatment layer such as a hard coat layer, an antireflection layer, or an antistatic layer described later. A polarizer and a protective film can be laminated | stacked through an adhesive bond layer or an adhesive layer, for example. The member with which a polarizing plate is provided is demonstrated below.

(1) Polarizer The polarizer provided in the polarizing plate absorbs linearly polarized light having a vibration surface parallel to the absorption axis and transmits linearly polarized light having a vibration surface orthogonal to the absorption axis (parallel to the transmission axis). It can be an absorptive polarizer having properties. As the polarizer of the first layer, a polarizer in which a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol-based resin film can be suitably used. The polarizer is, for example, a step of uniaxially stretching a polyvinyl alcohol resin film; a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol resin film with a dichroic dye; a polyvinyl on which the dichroic dye is adsorbed It can be produced by a method comprising a step of treating an alcohol-based resin film with a crosslinking solution such as an aqueous boric acid solution; and a step of washing with water after the treatment with the crosslinking solution.

  As the polyvinyl alcohol resin, a saponified polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers with other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, (meth) acrylamides having ammonium groups, and the like.

  In the present specification, “(meth) acryl” means at least one selected from acryl and methacryl. The same applies to “(meth) acryloyl”, “(meth) acrylate”, and the like.

  The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The average degree of polymerization of the polyvinyl alcohol resin is usually 1000 to 10000, preferably 1500 to 5000. The average degree of polymerization of the polyvinyl alcohol resin can be determined according to JIS K 6726.

  What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of a polarizer (polarizer). The method for forming the polyvinyl alcohol-based resin into a film is not particularly limited, and a known method is employed. The thickness of the polyvinyl alcohol raw film is not particularly limited, but in order to make the thickness of the polarizer 15 μm or less, it is preferable to use a film having a thickness of 5 to 35 μm. More preferably, it is 20 μm or less.

  Uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing the dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the crosslinking treatment. Moreover, you may uniaxially stretch in these several steps.

  In uniaxial stretching, it may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a hot roll. Further, the uniaxial stretching may be dry stretching in which stretching is performed in the air, or may be wet stretching in which stretching is performed in a state where a polyvinyl alcohol-based resin film is swollen using a solvent or water. The draw ratio is usually 3 to 8 times.

  As a method for dyeing a polyvinyl alcohol-based resin film with a dichroic dye, for example, a method of immersing the film in an aqueous solution containing the dichroic dye is employed. As the dichroic dye, iodine or a dichroic organic dye is used. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.

  As the crosslinking treatment after dyeing with a dichroic dye, a method of immersing a dyed polyvinyl alcohol resin film in a boric acid-containing aqueous solution is usually employed. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide.

  The thickness of the polarizer is usually 15 μm or less, preferably 13 μm or less, more preferably 10 μm or less, and further preferably 8 μm or less. The thickness of the polarizer is usually 2 μm or more and preferably 3 μm or more. According to the study by the present inventors, it has been clarified that the change in the hue of the circularly polarizing plate is caused by the change in the retardation value of the retardation film. Furthermore, it has been clarified that the change in the retardation value of the retardation film is caused by stress when the polarizing plate undergoes dimensional shrinkage in a circularly polarizing plate placed in a high temperature environment. Therefore, from the viewpoint of reducing the influence due to the contraction of the polarizer, setting the thickness of the polarizer to 15 μm or less is effective in preventing a change in the reflected hue.

  As the polarizer, for example, as described in JP-A-2006-170368, a cured film obtained by polymerizing a liquid crystal compound and a dichroic dye aligned may be used. As the dichroic dye, those having absorption within a wavelength range of 380 to 800 nm can be used, and an organic dye is preferably used. Examples of the dichroic dye include azo compounds. The liquid crystal compound is a liquid crystal compound that can be polymerized while being aligned, and can have a polymerizable group in the molecule. Further, as described in WO2011 / 024891, a polarizer may be formed from a dichroic dye having liquid crystallinity.

  The contraction force of the polarizer is preferably 2.0 N / 2 mm or less, more preferably 1.8 N / mm or less, and further preferably 1.5 N or less. In addition, the measuring method of the contractile force of a polarizer is based on the method as described in the Example mentioned later.

(2) Protective film The circularly-polarizing plate of this invention has a protective film on both surfaces of a polarizer. The protective film located between the polarizer and the retardation film has negative birefringence. Here, the negative birefringence means that a slow axis appears in a direction perpendicular to the stretching direction of the resin. Since the retardation film includes a retardation layer having positive birefringence, a retardation opposite to the retardation expression of the retardation film accompanying the thermal contraction of the polarizer is expressed. The color change is considered to be small. Here, positive birefringence means that a slow axis appears in a direction parallel to the stretching direction of the retardation film.

  The protective film laminated on both surfaces of the polarizer is a light-transmitting (preferably optically transparent) thermoplastic resin such as a chain polyolefin resin (polypropylene resin, etc.), a cyclic polyolefin resin (norbornene). Polyolefin resins such as triacetyl cellulose and diacetyl cellulose; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polycarbonate resins; and methyl methacrylate resins ( (Meth) acrylic resin; polystyrene resin; polyvinyl chloride resin; acrylonitrile / butadiene / styrene resin; acrylonitrile / styrene resin; polyvinyl acetate resin; polyvinylidene chloride resin; polyamide resin; It can be made from a maleimide resin film; system resin; modified polyphenylene ether resin; polysulfone resins; poly (ether sulfone) resins; polyarylate resin; polyamideimide resin; polyimide resin.

  In particular, the protective film used between the polarizer and the retardation film preferably has a negative birefringence. That is, it is preferable to use a film containing at least one selected from the group consisting of (meth) acrylic resins, polystyrene resins, and maleimide resins. By using such a resin film as a protective film, a polarizing plate having excellent durability can be obtained even when processed into an irregular shape.

The (meth) acrylic resin is a resin containing a compound having a (meth) acryloyl group as a main constituent monomer. Specific examples of (meth) acrylic resins include, for example, poly (meth) acrylic acid esters such as polymethyl methacrylate; methyl methacrylate- (meth) acrylic acid copolymer; methyl methacrylate- (meth) acrylic acid Ester copolymer; methyl methacrylate-acrylic ester- (meth) acrylic acid copolymer; (meth) methyl acrylate-styrene copolymer (MS resin etc.); methyl methacrylate and alicyclic hydrocarbon group And a copolymer (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.). Preferably, a polymer having a poly (meth) acrylic acid C _1-6 alkyl ester as a main component, such as poly (meth) acrylic acid methyl, is used, more preferably, methyl methacrylate is the main component (50 to 100). % Methyl methacrylate resin is used.

The in-plane retardation value Re of the (meth) acrylic resin film at a wavelength of 590 nm is preferably 10 nm or less, more preferably 7 nm or less, still more preferably 5 nm or less, and particularly preferably 3 nm or less. Yes, most preferably 1 nm or less. The thickness direction retardation value Rth of the (meth) acrylic resin film at a wavelength of 590 nm is preferably 15 nm or less, more preferably 10 nm or less, further preferably 5 nm or less, and particularly preferably 3 nm or less. Most preferably, it is 1 nm or less. If the in-plane retardation value and the thickness direction retardation value are in such a range, the color change during the heat resistance test can be significantly suppressed without impairing the properties of the retardation film described later. In order to set the in-plane retardation value and the retardation value in the thickness direction in such a range, for example, it can be obtained by using a (meth) acrylic resin having a glutarimide structure described later.

The (meth) acrylic resin may preferably have a structural unit that exhibits positive birefringence in a range having negative birefringence. If it has a structural unit that expresses positive birefringence and a structural unit that expresses negative birefringence, the abundance ratio can be adjusted to control the phase difference of the (meth) acrylic resin film. And a (meth) acrylic resin film having a low retardation can be obtained. Examples of the structural unit exhibiting positive birefringence include a structural unit constituting a lactone ring, polycarbonate, polyvinyl alcohol, cellulose acetate, polyester, polyarylate, polyimide, polyolefin, etc., and a general formula (1) described later. Examples include structural units. Examples of the structural unit exhibiting negative birefringence include a structural unit derived from a styrene monomer, a maleimide monomer, a structural unit of polymethyl methacrylate, a structural unit represented by the general formula (3) described later, and the like. Can be mentioned.

As the (meth) acrylic resin, a (meth) acrylic resin having a lactone ring structure or a glutarimide structure is preferably used. A (meth) acrylic resin having a lactone ring structure or a glutarimide structure is excellent in heat resistance. More preferred is a (meth) acrylic resin having a glutarimide structure. If a (meth) acrylic resin having a glutarimide structure is used, a (meth) acrylic resin film having low moisture permeability and a small retardation and ultraviolet transmittance can be obtained as described above. Examples of (meth) acrylic resins having a glutarimide structure (hereinafter also referred to as glutarimide resins) include, for example, JP-A-2006-309033, JP-A-2006-317560, JP-A-2006-328329, and JP-A-2006-328329. 2006-328334, JP-A 2006-337491, JP-A 2006-337492, JP-A 2006-337493, JP-A 2006-337469, JP-A 2007-009182, JP-A 2009- No. 161744. These descriptions are incorporated herein by reference.

Preferably, the glutarimide resin includes a structural unit represented by the following general formula (1) (hereinafter also referred to as a glutarimide unit) and a structural unit represented by the following general formula (2) (hereinafter referred to as (meta)). Also referred to as an acrylate unit).

式（１）において、Ｒ^１およびＲ^２は、それぞれ独立して、水素または炭素数１〜８のアルキル基であり、Ｒ^３は、水素、炭素数１〜１８のアルキル基、炭素数３〜１２のシクロアルキル基、または炭素数５〜１５の芳香環を含む置換基である。式（２）において、Ｒ^４およびＲ^５は、それぞれ独立して、水素または炭素数１〜８のアルキル基であり、Ｒ^６は、水素、炭素数１〜１８のアルキル基、炭素数３〜１２のシクロアルキル基、または炭素数５〜１５の芳香環を含む置換基である。

In Formula (1), R ¹ and R ² are each independently hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ³ is hydrogen, an alkyl group having 1 to 18 carbon atoms, or 3 to 3 carbon atoms. It is a substituent containing 12 cycloalkyl groups or an aromatic ring having 5 to 15 carbon atoms. In Formula (2), R ⁴ and R ⁵ are each independently hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁶ is hydrogen, an alkyl group having 1 to 18 carbon atoms, or 3 to 3 carbon atoms. It is a substituent containing 12 cycloalkyl groups or an aromatic ring having 5 to 15 carbon atoms.

The glutarimide resin may further contain a structural unit represented by the following general formula (3) (hereinafter also referred to as an aromatic vinyl unit) as necessary.

In Formula (3), R ⁷ is hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁸ is an aryl group having 6 to 10 carbon atoms.

In the general formula (1), preferably, R ¹ and R ² are each independently hydrogen or a methyl group, R ³ is hydrogen, a methyl group, a butyl group, or a cyclohexyl group, and more preferably , R ¹ is a methyl group, R ² is hydrogen, and R ³ is a methyl group.

The glutarimide resin may include only a single type as a glutarimide unit, or may include a plurality of types in which R ¹ , R ² , and R ³ in the general formula (1) are different. Good.

The glutarimide unit can be formed by imidizing the (meth) acrylic acid ester unit represented by the general formula (2). The glutarimide unit is an acid anhydride such as maleic anhydride, or a half ester of such an acid anhydride and a linear or branched alcohol having 1 to 20 carbon atoms; acrylic acid, methacrylic acid, maleic acid. It can also be formed by imidizing an α, β-ethylenically unsaturated carboxylic acid such as maleic anhydride, itaconic acid, itaconic anhydride, crotonic acid, fumaric acid, citraconic acid and the like.

In the general formula (2), preferably, R ⁴ and R ⁵ are each independently hydrogen or a methyl group, R ⁶ is hydrogen or a methyl group, and more preferably, R ⁴ is hydrogen. , R ⁵ is a methyl group, and R ⁶ is a methyl group.

The glutarimide resin may contain only a single type as a (meth) acrylic acid ester unit, or a plurality of types in which R ⁴ , R ⁵ and R ⁶ in the general formula (2) are different. May be included.

The glutarimide resin preferably contains styrene, α-methylstyrene, and more preferably styrene as the aromatic vinyl unit represented by the general formula (3). By having such an aromatic vinyl unit, the positive birefringence of the glutarimide structure can be reduced, and a (meth) acrylic resin film having a lower retardation can be obtained.

The glutarimide resin may contain only a single type as an aromatic vinyl unit, or may contain a plurality of types in which R ⁷ and R ⁸ are different.

The content of the glutarimide unit in the glutarimide resin is preferably changed depending on, for example, the structure of R ³ . The content of the glutarimide unit is preferably 1% by weight to 80% by weight, more preferably 1% by weight to 70% by weight, even more preferably 1% by weight, based on the total structural unit of the glutarimide resin. -60% by weight, particularly preferably 1-50% by weight. When the content of the glutarimide unit is in such a range, a (meth) acrylic resin film having a low retardation excellent in heat resistance can be obtained.

The content of the aromatic vinyl unit in the glutarimide resin can be appropriately set according to the purpose and desired characteristics. Depending on the application, the content of the aromatic vinyl unit may be zero. When the aromatic vinyl unit is contained, the content thereof is preferably 10% by weight to 80% by weight, more preferably 20% by weight to 80% by weight, based on the glutarimide unit of the glutarimide resin. More preferably, it is 20 to 60% by weight, and particularly preferably 20 to 50% by weight. When the content of the aromatic vinyl unit is within such a range, a (meth) acrylic resin film having a low retardation, excellent heat resistance and mechanical strength can be obtained.

The glutarimide resin may further be copolymerized with other structural units other than the glutarimide unit, the (meth) acrylic acid ester unit, and the aromatic vinyl unit, if necessary. Other structural units include, for example, nitrile monomers such as acrylonitrile and methacrylonitrile, and structures composed of maleimide monomers such as maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide. Units are listed. These other structural units may be directly copolymerized or graft copolymerized in the glutarimide resin.

The said (meth) acrylic-type resin film can contain arbitrary appropriate additives according to the objective. Examples of additives include hindered phenol-based, phosphorus-based, sulfur-based and the like antioxidants; light-resistant stabilizers, ultraviolet absorbers, weather-resistant stabilizers, heat stabilizers, and other stabilizers; glass fibers, carbon fibers, etc. Reinforcing materials; near infrared absorbers; flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, antimony oxide; antistatic agents such as anionic, cationic and nonionic surfactants; inorganic pigments, organic pigments, Colorants such as dyes; organic fillers and inorganic fillers; resin modifiers; plasticizers; lubricants; retardation reducing agents and the like. The kind, combination, content, and the like of the additive to be contained can be appropriately set according to the purpose and desired characteristics.

Although it does not specifically limit as a manufacturing method of the said (meth) acrylic-type resin film, For example, (meth) acrylic-type resin, an ultraviolet absorber, and other polymers, additives, etc. as needed Are sufficiently mixed by any appropriate mixing method to obtain a thermoplastic resin composition in advance, and then this can be formed into a film. Alternatively, a (meth) acrylic resin, an ultraviolet absorber, and if necessary, other polymers and additives are mixed in separate solutions to form a uniform mixed solution, and then film forming May be.

In order to produce the thermoplastic resin composition, for example, the film raw material is pre-blended with any appropriate mixer such as an omni mixer, and then the obtained mixture is extrusion kneaded. In this case, the mixer used for extrusion kneading is not particularly limited, and for example, any suitable mixer such as an extruder such as a single screw extruder or a twin screw extruder or a pressure kneader may be used. Can do.

Examples of the film forming method include any appropriate film forming method such as a solution casting method (solution casting method), a melt extrusion method, a calendar method, and a compression molding method. A melt extrusion method is preferred. Since the melt extrusion method does not use a solvent, it is possible to reduce the manufacturing cost and the burden on the global environment and work environment due to the solvent.

Examples of the melt extrusion method include a T-die method and an inflation method. The molding temperature is preferably 150 to 350 ° C, more preferably 200 to 300 ° C.

When film-forming by the above T-die method, a T-die is attached to the tip of a known single-screw extruder or twin-screw extruder, and the film extruded into a film is wound to obtain a roll-shaped film Can do. At this time, it is possible to perform uniaxial stretching by appropriately adjusting the temperature of the winding roll and adding stretching in the extrusion direction. Also, simultaneous biaxial stretching, sequential biaxial stretching, and the like can be performed by stretching the film in a direction perpendicular to the extrusion direction.

The (meth) acrylic resin film may be either an unstretched film or a stretched film as long as the desired retardation is obtained. In the case of a stretched film, either a uniaxially stretched film or a biaxially stretched film may be used. In the case of a biaxially stretched film, either a simultaneous biaxially stretched film or a sequential biaxially stretched film may be used.

  The stretching temperature is preferably in the vicinity of the glass transition temperature of the thermoplastic resin composition that is the film raw material, and specifically, preferably (glass transition temperature-30 ° C.) to (glass transition temperature + 30 ° C.) Preferably, it is within the range of (glass transition temperature−20 ° C.) to (glass transition temperature + 20 ° C.). If the stretching temperature is lower than (glass transition temperature −30 ° C.), the haze of the resulting film may increase, or the film may be torn or cracked, resulting in failure to obtain a predetermined stretching ratio. On the other hand, when the stretching temperature exceeds (glass transition temperature + 30 ° C.), the thickness unevenness of the resulting film becomes large, and the mechanical properties such as elongation, tear propagation strength, and fatigue resistance cannot be sufficiently improved. There is a tendency to. Furthermore, there is a tendency that troubles such as the film sticking to the roll tend to occur.

The draw ratio is preferably 1.1 to 3 times, more preferably 1.3 to 2.5 times. When the draw ratio is in such a range, the mechanical properties such as the film elongation, tear propagation strength, and fatigue resistance can be greatly improved. As a result, it is possible to produce a film with small thickness unevenness, substantially zero birefringence (and therefore a small phase difference), and a small haze.

The (meth) acrylic resin film can be subjected to heat treatment (annealing) or the like after the stretching treatment in order to stabilize its optical isotropy and mechanical properties. Arbitrary appropriate conditions can be employ | adopted for the conditions of heat processing.

The photoelastic coefficient of the (meth) acrylic resin film is preferably −3 to −100 × 10 ⁻¹³ Pa ⁻¹ , more preferably −5 to −70 × 10 ⁻¹³ Pa ⁻¹ , and further preferably. −15 to −50 × 10 ⁻¹³ Pa ⁻¹ . In addition, a photoelastic coefficient is the value measured by the method as described in the Example mentioned later.

The thickness of the (meth) acrylic resin film is preferably 10 μm to 200 μm, more preferably 20 μm to 100 μm. There exists a possibility that intensity | strength may fall that thickness is less than 10 micrometers. If the thickness exceeds 200 μm, the transparency may decrease.

As the 1st protective film 11, the same film as the above may be used, and another resin film may be used. For example, an olefin resin film, a polyester resin film, and a cellulose resin film are preferably used.

  As the chain polyolefin-based resin, polyethylene resin (polyethylene resin which is a homopolymer of ethylene or a copolymer mainly composed of ethylene), polypropylene resin (polypropylene resin which is a homopolymer of propylene, or propylene as a main component) And a copolymer composed of two or more chain olefins in addition to a chain olefin homopolymer such as

  The cyclic polyolefin resin is a general term for resins that are polymerized using a cyclic olefin as a polymerization unit, and is described, for example, in JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin. Specific examples of cyclic polyolefin resins include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins and chain olefins such as ethylene and propylene (typically Are random copolymers), graft polymers obtained by modifying them with unsaturated carboxylic acids or their derivatives, and hydrides thereof. Among these, norbornene resins using norbornene monomers such as norbornene and polycyclic norbornene monomers as cyclic olefins are preferably used.

  The polyester-based resin is a resin having an ester bond excluding the following cellulose ester-based resin, and is generally composed of a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. As the polyvalent carboxylic acid or a derivative thereof, a divalent dicarboxylic acid or a derivative thereof can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalenedicarboxylate. As the polyhydric alcohol, a divalent diol can be used, and examples thereof include ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol. A typical example of the polyester resin is polyethylene terephthalate which is a polycondensate of terephthalic acid and ethylene glycol.

  The cellulose ester resin is an ester of cellulose and a fatty acid. Specific examples of the cellulose ester resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Further, these copolymers and those in which a part of the hydroxyl group is modified with other substituents are also included. Among these, cellulose triacetate (triacetyl cellulose) is particularly preferable.

  When the in-plane retardation value Re (550) at a wavelength of 550 nm is set to 70 to 210 nm as the retardation value of the protective film 11, the visibility of the screen when the user wears polarized sunglasses or the like may be improved. it can.

  Although the thickness of the protective film 11 is usually 1 to 100 μm, it is preferably 5 to 60 μm, more preferably 10 to 55 μm, and further preferably 15 to 40 μm from the viewpoint of strength and handleability. .

  As described above, the protective film 11 has a hard coat layer, an antiglare layer, a light diffusion layer, an antireflection layer, a low refractive index layer, an antistatic layer, an antistatic layer on its outer surface (the surface opposite to the polarizer). A surface treatment layer (coating layer) such as a dirty layer may be provided. The thickness of the protective film 11 includes the thickness of the surface treatment layer.

  A protective film can be bonded to a polarizer through an adhesive layer or an adhesive layer, for example. As the adhesive forming the adhesive layer, a water-based adhesive, an active energy ray-curable adhesive, or a thermosetting adhesive can be used, and a water-based adhesive and an active energy ray-curable adhesive are preferable. As the pressure-sensitive adhesive layer, those described below can be used.

  Examples of the water-based adhesive include an adhesive made of a polyvinyl alcohol-based resin aqueous solution, an aqueous two-component urethane emulsion adhesive, and the like. Among these, a water-based adhesive composed of a polyvinyl alcohol-based resin aqueous solution is preferably used. Polyvinyl alcohol resins include vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. A polyvinyl alcohol copolymer obtained by saponifying a polymer, or a modified polyvinyl alcohol polymer obtained by partially modifying the hydroxyl group thereof can be used. The water-based adhesive can contain a crosslinking agent such as an aldehyde compound (glyoxal, etc.), an epoxy compound, a melamine compound, a methylol compound, an isocyanate compound, an amine compound, and a polyvalent metal salt.

  When using a water-based adhesive, it is preferable to carry out a drying step for removing water contained in the water-based adhesive after pasting the polarizer and the protective film. After the drying process, for example, a curing process for curing at a temperature of 20 to 45 ° C. may be provided.

  The active energy ray-curable adhesive is an adhesive containing a curable compound that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, and preferably ultraviolet curable adhesives. It is.

  The curable compound may be a cationic polymerizable curable compound or a radical polymerizable curable compound. Examples of the cationic polymerizable curable compound include an epoxy compound (a compound having one or more epoxy groups in the molecule) and an oxetane compound (one or two or more oxetane rings in the molecule). Or a combination thereof. Examples of the radical polymerizable curable compound include (meth) acrylic compounds (compounds having one or more (meth) acryloyloxy groups in the molecule) and radical polymerizable double bonds. Other vinyl compounds or combinations thereof can be mentioned. A cationic polymerizable curable compound and a radical polymerizable curable compound may be used in combination. The active energy ray-curable adhesive usually further includes a cationic polymerization initiator and / or a radical polymerization initiator for initiating a curing reaction of the curable compound.

  In laminating the polarizer and the protective film, a surface activation treatment may be applied to at least one of these laminating surfaces in order to enhance adhesiveness. As the surface activation treatment, dry treatment such as corona treatment, plasma treatment, discharge treatment (glow discharge treatment, etc.), flame treatment, ozone treatment, UV ozone treatment, ionizing active ray treatment (ultraviolet treatment, electron beam treatment, etc.) And wet treatment such as ultrasonic treatment using a solvent such as water and acetone, saponification treatment, and anchor coat treatment. These surface activation treatments may be performed alone or in combination of two or more.

  When protective films are bonded to both surfaces of the polarizer, the adhesive for bonding these protective films may be the same type of adhesive or different types of adhesives.

<Phase difference film>
The circularly polarizing plate of the present invention has a retardation film, and the retardation film has a retardation layer. The retardation layer preferably has a layer composed of a composition containing a polymerizable liquid crystal compound. Specifically, the layer composed of the composition containing a polymerizable liquid crystal compound means a layer obtained by curing the polymerizable liquid crystal compound. In this specification, a layer that gives a phase difference of λ / 2, a layer that gives a phase difference of λ / 4 (positive A layer), a positive C layer, and the like may be collectively referred to as a phase difference layer. Furthermore, the retardation film may include an alignment film described later.

  The layer in which the polymerizable liquid crystal compound is cured is formed, for example, on an alignment film provided on the substrate. The base material may have a function of supporting the alignment film and may be a long base material. This base material functions as a releasable support and can support a retardation layer for transfer. Furthermore, what has the adhesive force of the grade which the surface can peel is preferable. Examples of the substrate include resin films exemplified as the material for the protective film.

  Although it does not specifically limit as thickness of a base material, For example, it is preferable to set it as the range of 20 micrometers or more and 200 micrometers or less. When the thickness of the substrate is 20 μm or more, strength is imparted. On the other hand, when the thickness is 200 μm or less, it is possible to suppress an increase in processing waste and wear of the cutting blade when the substrate is cut into a single-wafer substrate.

  The base material may be subjected to various anti-blocking treatments. Examples of the anti-blocking process include an easy adhesion process, a process of kneading a filler and the like, an embossing process (knurling process), and the like. By applying such an anti-blocking treatment to the base material, it is possible to effectively prevent sticking between the base materials when winding the base material, so-called blocking, and to produce an optical film with high productivity. Is possible.

  The layer in which the polymerizable liquid crystal compound is cured is formed on the substrate via the alignment film. That is, a layer in which the base material and the alignment film are stacked in this order and the polymerizable liquid crystal compound is cured is stacked on the alignment film.

  The alignment film is not limited to the vertical alignment film, and may be an alignment film that horizontally aligns the molecular axis of the polymerizable liquid crystal compound, or may be an alignment film that tilts and aligns the molecular axis of the polymerizable liquid crystal compound. . The alignment film has a solvent resistance that does not dissolve by application of a composition containing a polymerizable liquid crystal compound, which will be described later, and has heat resistance in heat treatment for removing the solvent or aligning the liquid crystal compound. preferable. Examples of the alignment film include an alignment film containing an alignment polymer, a photo-alignment film, and a groove alignment film that forms an uneven pattern or a plurality of grooves on the surface and aligns them. The thickness of the alignment film is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm, more preferably 500 nm or less, and further preferably in the range of 10 nm to 200 nm. When the retardation film has an alignment film, the puncture elastic modulus is easily increased by increasing the thickness of the alignment film. By setting the thickness of the alignment film in the above range, moderate rigidity and toughness can be imparted to the polymerizable liquid crystal compound, and high film strength can be imparted.

  The resin used for the alignment film is not particularly limited as long as it is a resin used as a material for a known alignment film. A conventionally known monofunctional or polyfunctional (meth) acrylate monomer is used under a polymerization initiator. A cured product or the like that has been cured can be used. Specifically, as the (meth) acrylate monomer, for example, 2-ethylhexyl acrylate, cyclohexyl acrylate, diethylene glycol mono 2-ethylhexyl ether acrylate, diethylene glycol monophenyl ether acrylate, tetraethylene glycol monophenyl ether acrylate, trimethylolpropane triacrylate , Lauryl acrylate, lauryl methacrylate, isobornyl acrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxypropyl acrylate, benzyl acrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl methacrylate, benzyl methacrylate , Cyclo Hexyl methacrylate, methacrylic acid, can be exemplified urethane acrylate. In addition, as resin, one of these may be sufficient and a 2 or more types of mixture may be sufficient.

  The type of the polymerizable liquid crystal compound used in the present embodiment is not particularly limited, but is classified into a rod-shaped type (bar-shaped liquid crystal compound) and a disk-shaped type (disk-shaped liquid crystal compound, discotic liquid crystal compound) depending on its shape. it can. Furthermore, there are a low molecular type and a high molecular type, respectively. Polymer generally means a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992).

  In the present embodiment, any polymerizable liquid crystal compound can be used. Further, two or more kinds of rod-like liquid crystal compounds, two or more kinds of disk-like liquid crystal compounds, or a mixture of a rod-like liquid crystal compound and a disk-like liquid crystal compound may be used.

  As the rod-like liquid crystal compound, for example, the one described in claim 1 of JP-T-11-53019 or paragraphs [0026] to [0098] of JP-A-2005-289980 is preferably used. Can do. As the discotic liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 or paragraphs [0013] to [0108] of JP-A-2010-244038 are suitable. Can be used.

  Two or more polymerizable liquid crystal compounds may be used in combination. In that case, at least one kind has two or more polymerizable groups in the molecule. That is, the layer obtained by curing the polymerizable liquid crystal compound is preferably a layer formed by fixing a liquid crystal compound having a polymerizable group by polymerization. In this case, it is no longer necessary to exhibit liquid crystallinity after forming a layer.

  The polymerizable liquid crystal compound has a polymerizable group capable of undergoing a polymerization reaction. As the polymerizable group, for example, a functional group capable of addition polymerization reaction such as a polymerizable ethylenically unsaturated group or a ring polymerizable group is preferable. More specifically, examples of the polymerizable group include a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among these, a (meth) acryloyl group is preferable. The (meth) acryloyl group is a concept including both a methacryloyl group and an acryloyl group.

  As described later, the layer in which the polymerizable liquid crystal compound is cured can be formed by applying a composition containing the polymerizable liquid crystal compound on, for example, an alignment film and irradiating active energy rays. The composition may contain a component other than the polymerizable liquid crystal compound described above. For example, it is preferable that the composition contains a polymerization initiator. As the polymerization initiator to be used, for example, a thermal polymerization initiator or a photopolymerization initiator is selected according to the type of the polymerization reaction. Examples of the photopolymerization initiator include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, combinations of triarylimidazole dimers and p-aminophenyl ketones. The amount of the polymerization initiator used is preferably 0.01 to 20% by mass and more preferably 0.5 to 5% by mass with respect to the total solid content in the coating solution.

  In addition, the composition may contain a polymerizable monomer from the viewpoint of the uniformity of the coating film and the strength of the film. Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Among these, a polyfunctional radically polymerizable monomer is preferable.

  In addition, as a polymerizable monomer, what can be copolymerized with the polymeric liquid crystal compound mentioned above is preferable. It is preferable that the usage-amount of a polymerizable monomer is 1-50 mass% with respect to the total mass of a polymerizable liquid crystal compound, and it is more preferable that it is 2-30 mass%.

  The composition may contain a surfactant from the viewpoint of the uniformity of the coating film and the strength of the film. Examples of the surfactant include conventionally known compounds. Of these, fluorine compounds are particularly preferred.

The composition may contain a solvent, and an organic solvent is preferably used.
Examples of the organic solvent include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, ethyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Of these, alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.

  Further, the composition includes a vertical alignment promoter such as a polarizer interface side vertical alignment agent and an air interface side vertical alignment agent, and a horizontal alignment promotion such as a polarizer interface side horizontal alignment agent and an air interface side horizontal alignment agent. Various alignment agents such as an agent may be contained. Furthermore, in addition to the above components, the composition may contain an adhesion improver, a plasticizer, a polymer, and the like.

  The active energy rays include ultraviolet rays, visible light, electron beams, and X-rays, and are preferably ultraviolet rays. Examples of the light source of the active energy ray include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, and a wavelength range. Examples include LED light sources that emit light of 380 to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, and the like.

The irradiation intensity of ultraviolet radiation is typically the case of ultraviolet B wave (wavelength range 280 to 320 ^nm), a ^{10mW / cm 2 ~3,000mW / cm 2} . The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating the cationic polymerization initiator or radical polymerization initiator. The time for irradiation with ultraviolet rays is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and further preferably 0.1 seconds. ~ 1 minute.

Ultraviolet rays can be irradiated once or several times. Depending on the polymerization initiator used, the accumulated amount of light at a wavelength of 365nm is preferably in a 700 mJ / cm ² or more, more preferably, to 1,100mJ / cm ² or more, 1,300mJ / cm ² or more and More preferably. Setting the integrated light amount is advantageous in increasing the polymerization rate of the polymerizable liquid crystal compound constituting the retardation film and improving the heat resistance. Integrated light intensity at a wavelength of 365nm is preferably in a 2,000 mJ / cm ² or less, and more preferably to 1,800mJ / cm ² or less. Setting the integrated light amount may cause coloring of the retardation film.

  In the present embodiment, the thickness of the retardation layer is preferably 0.5 μm or more. Further, the thickness of the retardation layer is preferably 10 μm or less, and more preferably 5 μm or less. In addition, the upper limit value and lower limit value mentioned above can be combined arbitrarily. Sufficient durability is acquired as the thickness of a phase difference layer is more than the said lower limit. When the thickness of the retardation layer is not more than the above upper limit value, it can contribute to the thinning of the circularly polarizing plate. As for the thickness of the retardation layer, a desired in-plane retardation value and a retardation value in the thickness direction of a layer that gives a retardation of λ / 4, a layer that gives a retardation of λ / 2, or a positive C layer can be obtained. Can be adjusted.

  The retardation film may include one layer in which the polymerizable liquid crystal compound is cured, or may include two or more layers in which the polymerizable liquid crystal compound is cured. When the retardation film includes two layers in which the polymerizable liquid crystal compound is cured, the two layers are a layer giving a retardation of λ / 4 and a positive C layer, or a layer giving a retardation of λ / 4 and λ / 2 It is preferable that the layer gives a phase difference of. When the retardation film includes two layers in which the polymerizable liquid crystal compound is cured, the layers in which the polymerizable liquid crystal compound is cured are respectively formed on the alignment film, and both are laminated via the adhesive layer or the pressure-sensitive adhesive layer. Thus, the retardation film may be manufactured. After laminating both, the substrate and the alignment film can be peeled off. The thickness of the retardation film is preferably 3 to 30 μm, and more preferably 5 to 25 μm.

The photoelastic coefficient of the retardation film is preferably 3 to 100 × 10 ⁻¹³ Pa ⁻¹ , more preferably 5 to 70 × 10 ⁻¹³ Pa ⁻¹ , and further preferably 15 to 60 × 10 ⁻¹³ Pa ^{−1. −1} , and more preferably 20 to 60 × 10 ⁻¹³ Pa ⁻¹ . In addition, a photoelastic coefficient is the value measured by the method as described in the Example mentioned later.

<Adhesive layer>
The pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition mainly composed of a resin such as (meth) acrylic, rubber-based, urethane-based, ester-based, silicone-based, or polyvinyl ether-based. Especially, the adhesive composition which uses (meth) acrylic resin excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is suitable. The pressure-sensitive adhesive composition may be an active energy ray curable type or a thermosetting type. The thickness of an adhesive layer is 3-30 micrometers normally, Preferably it is 3-25 micrometers.

  Examples of the (meth) acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and (meth) acrylic acid 2- A polymer or copolymer having one or more (meth) acrylic acid esters such as ethylhexyl as a monomer is preferably used. The base polymer is preferably copolymerized with a polar monomer. Examples of polar monomers include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, glycidyl ( Mention may be made of monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as (meth) acrylate.

  The pressure-sensitive adhesive composition may contain only the above base polymer, but usually further contains a crosslinking agent. As a crosslinking agent, a metal ion having a valence of 2 or more, which forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound, which forms an amide bond with a carboxyl group; Examples thereof include epoxy compounds and polyols that form ester bonds with carboxyl groups; polyisocyanate compounds that form amide bonds with carboxyl groups. Of these, polyisocyanate compounds are preferred.

<Front plate>
The front plate is disposed on the viewing side of the polarizing plate. The front plate can be laminated on the polarizing plate via an adhesive layer. Examples of the adhesive layer include the aforementioned pressure-sensitive adhesive layer and adhesive layer. As shown in FIGS. 2A and 2B, the front plate 4 can be laminated on the protective film 11 in the polarizing plate 1 via the pressure-sensitive adhesive layer 16.

  Examples of the front plate include glass and a resin film including a hard coat layer on at least one surface. As glass, for example, highly transmissive glass or tempered glass can be used. In particular, when a thin transparent surface material is used, glass subjected to chemical strengthening is preferable. The thickness of the glass can be set to 100 μm to 5 mm, for example.

  A front plate comprising a hard coat layer on at least one surface of a resin film is not rigid like existing glass, and can have flexible characteristics. The thickness of a hard-coat layer is not specifically limited, For example, 5-100 micrometers may be sufficient.

  Resin films include cycloolefin derivatives having units of monomers containing cycloolefin, such as norbornene or polycyclic norbornene monomers, cellulose (diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, isobutyl ester cellulose) , Propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose) ethylene-vinyl acetate copolymer, polycycloolefin, polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyamideimide, polyethersulfone, polysulfone, polyethylene, Polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether Ketones, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, or a film formed of a polymer such as epoxy. As the resin film, an unstretched, uniaxial or biaxially stretched film can be used. These polymers can be used alone or in admixture of two or more. The resin film is a polyamideimide film or polyimide film excellent in transparency and heat resistance, uniaxial or biaxially stretched polyester film, a cycloolefin-based derivative film that is excellent in transparency and heat resistance, and can cope with an increase in size of the film. Polymethyl methacrylate films and triacetyl cellulose and isobutyl ester cellulose films having no transparency and optical anisotropy are preferred. The thickness of the resin film may be 5 to 200 μm, preferably 20 to 100 μm.

  The hard coat layer can be formed by curing a hard coat composition containing a reactive material that forms a crosslinked structure by irradiation with light or heat energy. The hard coat layer can be formed by curing a hard coat composition containing a photocurable (meth) acrylate monomer or oligomer and a photocurable epoxy monomer or oligomer simultaneously. The photocurable (meth) acrylate monomer may include one or more selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate, and polyester (meth) acrylate. The epoxy (meth) acrylate can be obtained by reacting an epoxy compound with a carboxylic acid having a (meth) acryloyl group.

  The hard coat composition may further include one or more selected from the group consisting of a solvent, a photoinitiator, and an additive. The additive may include one or more selected from the group consisting of inorganic nanoparticles, a leveling agent, and a stabilizer. In addition to the above, each component generally used in the art includes, for example, It may further contain an oxidizing agent, a UV absorber, a surfactant, a lubricant, an antifouling agent, and the like.

<Shading pattern>
The light shielding pattern can be provided as at least part of a bezel or a housing of a display device to which the front plate or the front plate is applied. The light shielding pattern can be formed on the display element side of the front plate. The light shielding pattern can hide each wiring of the display device so that it is not visually recognized by the user. The color and / or material of the light shielding pattern is not particularly limited, and can be formed of resin materials having various colors such as black, white, and gold. In one embodiment, the thickness of the light shielding pattern may be 2 μm to 50 μm, preferably 4 μm to 30 μm, and more preferably 6 μm to 15 μm. Further, a shape can be imparted to the light shielding pattern in order to suppress bubble mixing due to a step between the light shielding pattern and the display portion and visual recognition of the boundary portion.

<Method for producing circularly polarizing plate>
Taking the circularly polarizing plate 100 shown in FIG. 1A as an example, a method of manufacturing a circularly polarizing plate will be described. The circularly polarizing plate 100 can be manufactured by laminating the polarizing plate 1 and the retardation film 2 via the pressure-sensitive adhesive layer 13.

  The polarizing plate 1 can be manufactured by laminating the polarizer 10 and the protective films 11 and 12 via adhesive layers. The polarizing plate may be manufactured by preparing long members and bonding the respective members with roll-to-roll, and then cutting them into a predetermined shape, or cutting each member into a predetermined shape. You may paste together later. After bonding the protective films 11 and 12 to the polarizer 10, a heating process or a humidity control process may be provided.

  The retardation film 2 can be manufactured, for example, as follows. An alignment film is formed on the substrate, and a coating liquid containing a polymerizable liquid crystal compound is applied on the alignment film. In the state in which the polymerizable liquid crystal compound is aligned, the active energy ray is irradiated to cure the polymerizable liquid crystal compound. The pressure-sensitive adhesive layer 14 formed on the release film is laminated on the layer where the polymerizable liquid crystal compound is cured. Next, the substrate and / or the alignment film are peeled off. Next, the pressure-sensitive adhesive layer 13 formed on the release film is laminated on the protective film 12. The retardation film 2 may be manufactured by preparing long members and bonding the respective members with roll-to-roll, and then cutting them into a predetermined shape. After cutting, they may be bonded together.

  And the circularly-polarizing plate 100 can be produced by peeling the peeling film laminated | stacked on the adhesive layer 13, and bonding the retardation film 2 and the polarizing plate 1 through the adhesive layer 13. FIG. .

<Application>
The circularly polarizing plate can be used for various display devices. A display device is a device having a display element and includes a light-emitting element or a light-emitting device as a light-emitting source. Examples of the display device include a liquid crystal display device, an organic EL display device, an inorganic electroluminescence (hereinafter also referred to as inorganic EL) display device, an electron emission display device (for example, a field emission display device (also referred to as FED), and a surface field emission display. Device (also referred to as SED)), electronic paper (display device using electronic ink and electrophoretic elements, plasma display device, projection display device (eg, grating light valve (also referred to as GLV) display device), digital micromirror device (DMD) Display device), piezoelectric ceramic display, etc. The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, etc. These display devices are two-dimensional images. May be a display device that displays a 3D display device that displays a three-dimensional image What it may be. Yen polarizing plate can be particularly used particularly effectively in the organic EL display device or an inorganic EL display device.

  2A and 2B, in the organic EL display devices 104 and 105, a circularly polarizing plate is laminated on the organic EL display element 3 through an adhesive layer 14 laminated on the retardation film 20. It has a layer structure.

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further more concretely, this invention is not limited by these examples. In the examples, the parts and% representing the content or amount used are based on weight unless otherwise specified. In addition, the measurement of each physical property in the following examples was performed by the following method.

(1) Measuring method of film thickness It measured using MH-15M which is a digital micrometer made from Nikon Corporation.

(2) Measuring method of phase difference value It measured using phase difference measuring device KOBRA-WPR (made by Oji Scientific Instruments).
(3) Method of measuring reflected hue The reflected hue (a *, b *) was measured using a spectrocolorimeter (Konica Minolta Japan, Inc., trade name: CM-2600d). The reflected hue is a value when the light source is D65, and was measured by the SCI method (including regular reflected light).
(4) Photoelastic coefficient measurement method Using a phase difference measuring device KOBRA-WPR (manufactured by Oji Scientific Instruments Co., Ltd.), both ends of a sample (size 1.5 cm × 6 cm) are sandwiched to stress (0.5 N to 8 N). ), The retardation value (23 ° C./wavelength 550 nm) at the center of the sample was measured and calculated from the slope of the function of stress and retardation value. In this specification, a sample having positive birefringence is described as a positive value, and a sample having negative birefringence is described as a negative value. In addition, the measurement sample of the photoelastic coefficient of a retardation film produced the laminated body which consists of retardation film / adhesive A mentioned later / protective film C mentioned later, the slow axis of this laminated body, and the above-mentioned measurement sample. The sample for measurement was cut out so that the long sides of the were parallel. As the photoelastic coefficient of the retardation film, a value obtained by measuring while applying stress while sandwiching both short sides of the measurement sample was used. In stacking samples, corona treatment was performed on the stacking surface before stacking.
(5) Measuring method of contraction force of polarizer A piece of 2 mm in width and 50 mm in length was cut with a super cutter manufactured by Sugano Seiki Co., Ltd. so that the absorption axis direction of the polarizer was the major axis. The obtained strip-shaped polarizing film was used as a shrinkage force measurement sample. Set the sample for contraction force measurement to a thermomechanical analyzer (“TMA / 6100” manufactured by Hitachi High-Tech Science Co., Ltd.) with a distance between chucks of 10 mm, and place the test piece in a room at a temperature of 20 ° C./relative humidity of 55%. After being allowed to stand, the temperature in the sample chamber was raised from 20 ° C. to 80 ° C. over 1 minute, and the temperature in the sample chamber was set to be maintained at 80 ° C. after the temperature rise. After allowing the temperature to rise for 4 hours, the contraction force in the long side direction of the measurement sample was measured in an environment at 80 ° C. In this measurement, the static load was 0 mN, and a SUS probe was used as the jig.

[Production Example 1] Production of polarizing film A polyvinyl alcohol film having a thickness of 20 µm (average polymerization degree of about 2400, saponification degree of 99.9 mol% or more) is uniaxially stretched by about 4 times by dry stretching, and further maintained in a tension state. The sample was immersed in pure water at 40 ° C. for 40 seconds, and then immersed in an aqueous solution having an iodine / potassium iodide / water weight ratio of 0.052 / 5.7 / 100 at 28 ° C. for 30 seconds to perform a dyeing treatment. It was. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 11.0 / 6.2 / 100 at 70 ° C. for 120 seconds. Subsequently, after washing with pure water at 8 ° C. for 15 seconds, the film is dried at 60 ° C. for 50 seconds and then at 75 ° C. for 20 seconds while being held at a tension of 300 N, and iodine is adsorbed and oriented on the polyvinyl alcohol film. An absorption polarizer having a thickness of 8 μm was obtained. The contraction force of the obtained polarizer was 1.5 N / 2 mm.

[Production Example 2] Production of retardation film 5 parts (weight average molecular weight: 30000) of photoalignable material having the following structure and 95 parts of cyclopentanone (solvent) were mixed as components, and the resulting mixture was mixed at 80 ° C. The composition for alignment film formation was obtained by stirring for 1 hour.

以下に示す重合性液晶化合物Ａ、及び重合性液晶化合物Ｂを９０：１０の質量比で混合した混合物に対して、レベリング剤（Ｆ−５５６；ＤＩＣ社製）を１．０部、及び重合開始剤である２−ジメチルアミノ−２−ベンジル−１−（４−モルホリノフェニル）ブタン−１−オン（「イルガキュア３６９（Ｉｒｇ３６９）」、ＢＡＳＦジャパン株式会社製）を６部添加した。
さらに、固形分濃度が１３％となるようにＮ−メチル−２−ピロリドン（ＮＭＰ）を添加し、８０℃で１時間攪拌することにより、液晶硬化膜形成用組成物を得た。
重合性液晶化合物Ａは特開２０１０−３１２２３号公報に記載の方法で製造した。また、重合性液晶化合物Ｂは、特開２００９−１７３８９３号公報に記載の方法に準じて製造した。以下にそれぞれの分子構造を示す。
［重合性液晶化合物Ａ］

1.0 parts of a leveling agent (F-556; manufactured by DIC) and polymerization start with respect to a mixture in which polymerizable liquid crystal compound A and polymerizable liquid crystal compound B shown below were mixed at a mass ratio of 90:10 6 parts of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (“Irgacure 369 (Irg369)”, manufactured by BASF Japan Ltd.) as an agent was added.
Further, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%, and the mixture was stirred at 80 ° C. for 1 hour to obtain a composition for forming a liquid crystal cured film.
The polymerizable liquid crystal compound A was produced by the method described in JP 2010-31223 A. The polymerizable liquid crystal compound B was produced according to the method described in JP2009-173893A. Each molecular structure is shown below.
[Polymerizable liquid crystal compound A]

［重合性液晶化合物Ｂ］

[Polymerizable liquid crystal compound B]

〔基材、配向膜、液晶化合物が硬化した層からなる積層体の製造〕
基材として５０μｍ厚のシクロオレフィン系フィルム〔日本ゼオン（株）製の商品名「ＺＦ−１４−５０」〕上にコロナ処理を実施した後、配向膜形成用組成物をバーコーターで塗布し、８０℃で１分間乾燥し、偏光ＵＶ照射装置〔ウシオ電機（株）の商品名「ＳＰＯＴ ＣＵＲＥ ＳＰ−９」〕を用いて、波長３１３ｎｍにおける積算光量：１００ｍＪ／ｃｍ^２で軸角度４５°にて偏光ＵＶ露光を実施した。続いて、配向膜に、配向液晶硬化膜形成用組成物を、バーコーターを用いて塗布し、１２０℃で１分間乾燥した後、高圧水銀ランプ〔ウシオ電機（株） の商品名：「ユニキュアＶＢ−１５２０１ＢＹ−Ａ」〕を用いて、紫外線を照射（窒素雰囲気下、波長３６５ｎｍにおける積算光量：５００ｍＪ／ｃｍ^２）することにより、液晶化合物が硬化した層を形成し、基材、配向膜及び液晶化合物が硬化した層からなる積層体を得た。

[Manufacture of a laminate comprising a base material, an alignment film, and a layer obtained by curing a liquid crystal compound]
After carrying out corona treatment on a 50 μm-thick cycloolefin film (trade name “ZF-14-50” manufactured by Nippon Zeon Co., Ltd.) as a substrate, the alignment film forming composition was applied with a bar coater, Drying at 80 ° C. for 1 minute and using a polarized UV irradiation device (trade name “SPOT CURE SP-9” of USHIO INC.), Integrated light quantity at a wavelength of 313 nm: 100 mJ / cm ² and an axial angle of 45 ° Polarized UV exposure was performed. Subsequently, the alignment liquid crystal cured film forming composition was applied to the alignment film using a bar coater, dried at 120 ° C. for 1 minute, and then a high-pressure mercury lamp [trade name of Ushio Electric Co., Ltd .: “Unicure VB”. -15201BY-A "], a layer in which the liquid crystal compound is cured is formed by irradiating ultraviolet rays (in a nitrogen atmosphere, integrated light quantity at a wavelength of 365 nm: 500 mJ / cm ² ), and the substrate, alignment film, and liquid crystal A laminate comprising a layer in which the compound was cured was obtained.

The in-plane retardation value Re (λ) of the layer obtained by curing the liquid crystal compound produced by the above method is bonded to glass via an adhesive and then peeled off the cycloolefin-based film as a substrate. It was measured. The measurement results of the phase difference value Re (λ) at each wavelength are Re (450) = 121 nm, Re (550) = 142 nm, Re (650) = 146 nm, Re (450) / Re (550) = 0.85, Re (650) / Re (550) = 1.03. Moreover, the photoelastic coefficient of the obtained retardation film was 53.9 * 10 <^-13> Pa < ^-1 >.

[Preparation of protective film]
Protective film A: a film in which a hard coat layer having a thickness of 3 μm is formed on a stretched film made of a norbornene-based resin having a thickness of 25 μm [trade name “COP25ST-HC” manufactured by Nippon Paper Industries Co., Ltd.
Protective film B: a triacetyl cellulose film having a thickness of 20 μm and positive birefringence (trade name “ZRG20SL” manufactured by FUJIFILM Corporation). The in-plane retardation value Re of the protective film B at a wavelength of 590 nm was 1.1 nm, and the thickness direction retardation value Rth was 1.3 nm. The photoelastic coefficient was 94 × 10 ⁻¹³ Pa ⁻¹ .
Protective film C: a norbornene-based resin film having a positive birefringence of 23 μm in thickness (trade name “ZF14-023” manufactured by Nippon Zeon Co., Ltd.). The in-plane retardation value Re of the protective film C at a wavelength of 590 nm was 0.7 nm, and the thickness direction retardation value Rth was 4.2 nm. The photoelastic coefficient was 16 × 10 ⁻¹³ Pa ⁻¹ .

Protective film D:
Methacrylic resin film b: produced by the following procedure. As a methacrylic resin, a copolymer of methyl methacrylate / methyl acrylate = 96% / 4% (weight ratio) was prepared. As rubber particles, the innermost layer is made of a hard polymer polymerized with methyl methacrylate using a small amount of allyl methacrylate, the intermediate layer is mainly composed of butyl acrylate, and further contains styrene and a small amount of allyl methacrylate. A three-layered elastic particle consisting of a hard polymer polymerized with a small amount of ethyl acrylate in methyl methacrylate, and consisting of a soft elastic material polymerized using A material having an average particle size up to a certain elastic body of 240 nm was prepared. In this rubber particle, the total weight of the innermost layer and the intermediate layer was 70% of the entire particle.

70% by weight of the methacrylic resin and 30% by weight of the rubber particles were mixed with a super mixer, and melt-kneaded with a twin screw extruder to obtain pellets. This pellet is put into a 65 mmφ single screw extruder, extruded through a T-shaped die having a set temperature of 275 ° C., cooled by sandwiching the film with two polishing rolls having a mirror surface, and negative birefringence with a thickness of 40 μm. Protective film D was obtained as a methacrylic resin film having properties. The in-plane retardation value Re of the protective film E at a wavelength of 590 nm was 1.4 nm, and the retardation value Rth in the thickness direction was −4.6 nm. The photoelastic coefficient of the obtained film was −47 × 10 ⁻¹³ Pa ⁻¹ .

Protective film E:
100 parts by weight of imidized MS resin pellets (weight average molecular weight: 105,000) described in Production Example 1 of JP 2010-284840 A are dried at 100.5 kPa and 100 ° C. for 12 hours, and are a single screw extruder Was extruded from a T die at a die temperature of 270 ° C. and formed into a film (thickness 160 μm). Further, the film is stretched in an atmosphere of 150 ° C. in the transport direction (thickness 80 μm), and then stretched in an atmosphere of 150 ° C. in a direction orthogonal to the film transport direction to give a negative birefringence of 40 μm in thickness. A protective film ((meth) acrylic resin film) was obtained. The in-plane retardation value Re of the protective film E at a wavelength of 590 nm was 0.5 nm, and the thickness direction retardation value Rth was 0.82 nm. The photoelastic coefficient of the obtained film was −9 × 10 ⁻¹³ Pa ⁻¹ .

Protective film F: Triacetyl cellulose film having a thickness of 40 μm and positive birefringence (trade name “KC4CZW” manufactured by Konica Minolta Opto Co., Ltd.). The in-plane retardation value Re of the protective film F at a wavelength of 590 nm was 1.2 nm, and the thickness direction retardation value Rth was −1.1 nm. The photoelastic coefficient was 75 × 10 ⁻¹³ Pa ⁻¹ .

[Preparation of Adhesive A]
3 parts by weight of a carboxyl group-modified polyvinyl alcohol (trade name “KL-318” manufactured by Kuraray Co., Ltd.) is dissolved in 100 parts by weight of water, and a polyamide-epoxy additive that is a water-soluble epoxy resin [Taoka Chemical Industries, Ltd.] 1.5 parts by weight of a trade name “Sumirez Resin (registered trademark) 650 (30)”, an aqueous solution having a solid concentration of 30% by weight] was added to prepare an adhesive A.

[Preparation of adhesive B]
After mixing the cation curable components a1 to a3 and the cation polymerization initiator shown below, the cation polymerization initiator and the sensitizer shown below are further mixed, and then defoamed to obtain a photocurable adhesive B. Prepared. In addition, the following compounding quantity is based on solid content.
Cationic curable component a1 (70 parts):
3 ′, 4′-epoxycyclohexylmethyl 3 ′, 4′-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation)
Cationic curable component a2 (20 parts):
Neopentyl glycol diglycidyl ether (trade name: EX-211, manufactured by Nagase ChemteX Corporation)
Cationic curable component a3 (10 parts):
2-ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation)
Cationic polymerization initiator (2.25 parts (solid content)):
Product name: 50% propylene carbonate solution / sensitizer (2 parts) of CPI-100 (manufactured by San Apro):
1,4-diethoxynaphthalene

[Preparation of adhesive layer]
Adhesive A: Sheet-like adhesive having a thickness of 5 μm (“NCF # L2” manufactured by Lintec Corporation)
Adhesive B: Sheet-like adhesive having a thickness of 25 μm (“P-3132” manufactured by Lintec Corporation)

[Preparation of reflector]
A non-lighting panel of an OLED device (Samsung Electronics Co., Ltd., trade name: Galaxy-Tab S8.4) was prepared as a reflector.

[Production Example 2] Production of polarizing plate with single-sided protective film Adhesive A was applied to one surface of the polarizing film obtained in Production Example 1, and protective film A was bonded. At this time, the protective film A was bonded so that the stretching direction was 45 degrees with respect to the absorption axis of the polarizer. Then, it was made to dry and the polarizing plate with a single-sided protective film was obtained.

[Example 1]
Adhesive B was applied to the polarizing film surface of the polarizing plate with a single-side protective film obtained in Production Example 2 to a thickness of 1 μm, and protective film D was bonded. Thereafter, irradiation with ultraviolet rays (“H bulb” manufactured by Fusion UV Systems Co., Ltd., integrated light quantity 400 mJ / cm ² ) was carried out, the adhesive was cured, and a polarizing plate with a double-sided protective film was obtained. A retardation film was bonded to the protective film D side of the obtained polarizing plate with double-sided protective film via an adhesive A. Here, the retardation film was laminated so that the slow axis of the retardation film was 45 ° counterclockwise with respect to the absorption axis of the polarizing film. Furthermore, the adhesive B was stuck on the surface opposite to the adhesive layer A side of the retardation film to obtain a circularly polarizing plate with an adhesive. In addition, when bonding these materials, the corona treatment was implemented to the bonding surface of each material.

  The obtained circularly polarizing plate was cut into 140 mm × 70 mm so that the absorption axis of the polarizing film was 45 ° counterclockwise with respect to the long side. The circularly polarizing plate was bonded to non-alkali glass (Corning Corp., Eagle XG) via the acrylic adhesive exposed by peeling the release film.

[Example 2]
In Example 1, instead of the protective film D, a circularly polarizing plate was produced in the same manner except that the protective film E was used, and a sample for evaluation was produced.

[Comparative Example 1]
In Example 1, a circularly polarizing plate was prepared in the same manner except that the protective film B was used instead of the protective film D, and a sample for evaluation was prepared.

[Comparative Example 2]
In Example 1, instead of the protective film D, a circularly polarizing plate was produced in the same manner except that the protective film C was used, and a sample for evaluation was produced.

[Comparative Example 3]
In Example 1, instead of the protective film D, a circularly polarizing plate was produced in the same manner except that the protective film F was used, and a sample for evaluation was produced.

[Hue evaluation before and after heat test]
Each evaluation sample thus obtained was put in an oven at 80 ° C. for 168 hours, the evaluation sample was placed on a reflector, and the reflection hue was measured. The measurement points were the points shown in FIG. Nine points shown in FIG. 3 are points in a region 5 mm inside from the end of the circularly polarizing plate, and the short side direction is located at intervals of about 30 mm, and the long side direction is located at intervals of about 65 mm.

As an evaluation of in-plane uniformity, when a * and b * of each measurement point were plotted on color coordinates, the evaluation was performed based on the distance between two points that are the farthest away. That is, a value having the largest value of the following formula between two points was taken as an evaluation result.

Δa * b * = [(Δa *) ² + (Δb *) ² ] ^1/2

Δa * and Δb * represent the difference between a * and b * between any two points.

Visibility evaluation A: Δa * b * ≦ 0.8 Thermal unevenness is not visible at all.
B: 0.8 <Δa * b * ≦ 1.0 Very slight thermal unevenness is visible.
C: 1.0 <Δa * b * ≦ 1.8 Thermal unevenness is slightly visible.
D: 1.8 <Δa * b * Thermal unevenness is clearly visible.

The evaluation results are shown in Table 1.

INDUSTRIAL APPLICABILITY According to the present invention, a circularly polarizing plate having a retardation film, which is useful because it can provide a circularly polarizing plate having a small hue change before and after being placed in a high temperature environment, is useful. In particular, when a circularly polarizing plate having a retardation film including a layer obtained by curing a polymerizable liquid crystal compound is placed in a high temperature environment, an in-plane change in the reflection hue of the circularly polarizing plate is likely to occur. Even in the case of a circularly polarizing plate having a retardation film including a layer in which a liquid crystal compound is cured, a change in hue can be sufficiently suppressed even in a high temperature environment.
Therefore, the circularly polarizing plate of the present invention can be effectively used for display devices, particularly organic EL display devices and inorganic EL display devices.

DESCRIPTION OF SYMBOLS 1 Polarizing plate 2 Phase difference film 3 Organic EL display element 4 Front plate 5 Point 10 Polarizer
DESCRIPTION OF SYMBOLS 11,12 Protective film 13,14,16 Adhesive layer 15 Adhesive layer 20,21 Layer 100,101,102 which hardened | cured polymeric liquid crystal compound Circularly-polarizing plate 104,105 Organic electroluminescent display apparatus

Claims (5)

A circularly polarizing plate having a polarizing plate and a retardation film,
The retardation film includes a retardation layer having positive birefringence,
The polarizing plate includes a polarizer having a thickness of 15 μm or less, and has protective films on both sides of the polarizer, and the protective film between the polarizer and the retardation film has negative birefringence. A circularly polarizing plate, which is a non-oriented film. The circularly polarizing plate according to claim 1, wherein the non-oriented film having negative birefringence contains at least one selected from the group consisting of (meth) acrylic resins, polystyrene resins, and maleimide resins. The circularly polarizing plate according to claim 1 or 2, wherein an in-plane retardation value of the non-oriented film having negative birefringence is 10 nm or less. The circularly polarizing plate according to claim 1, wherein the retardation layer is a layer obtained by curing a polymerizable liquid crystal compound. A display device in which the circularly polarizing plate according to claim 1 is laminated on a display element.

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