KR102068399B1 - Polarizing plate, display device, and organic electroluminescence display device - Google Patents

Abstract

An object of the present invention is to provide a polarizing plate capable of suppressing the change in transmittance and maintaining the display quality of the display device even when the display device is exposed in a high temperature, high humidity environment, and a display device having the same and an organic EL display device. . The polarizing plate of this invention is a polarizing plate which has an optically anisotropic layer arrange | positioned adjacent to a polarizer and a polarizer in this order from a visual recognition side, and a polarizer is an iodine type polarizer in which iodine is adsorbed-oriented to a polyvinyl alcohol-type film. The optically anisotropic layer is a layer obtained by curing a composition containing a liquid crystalline compound having a polymerizable group and a photopolymerization initiator, and the photopolymerization initiator contains a photopolymerization initiator X having a base dissociation constant pKb of 8 or more and a molecular weight of 240 or more. It is a polarizing plate whose content of the photoinitiator X is 60 mass% or more with respect to the total mass of a photoinitiator.

Description

Polarizer, display device and organic electro luminescence display device {POLARIZING PLATE, DISPLAY DEVICE, AND ORGANIC ELECTROLUMINESCENCE DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polarizing plates (particularly circular polarizing plates), display devices, and organic electroluminescence (EL) display devices.

Conventionally, in order to suppress the bad influence by external light reflection, a circularly polarizing plate is used for an organic electroluminescence display, an LCD display device, etc.

As a circularly polarizing plate, the aspect which combined the retardation plate (so-called wideband (lambda) / 4 board) which consists of (lambda) / 2 plate and (lambda) / 4 plate, and a polarizer is used suitably, For example, similar patent documents 1 and 2 are similar, The configuration is disclosed.

Patent Document 1: International Publication No. 2013/137464 Patent Document 2: Japanese Unexamined Patent Publication No. 2014-063143

On the other hand, in recent years, further improvement is required regarding the durability of the display device, and specifically, even when the display device is exposed to a high temperature, high humidity environment, the transmittance of the polarizing plate does not change, and it is possible to maintain the display quality of the display device. It is required.

MEANS TO SOLVE THE PROBLEM The present inventors bonded the polarizing plate specifically disclosed by patent document 1 and 2 to a display apparatus, and evaluated durability, when employing the iodine type polarizer in which iodine is adsorbed and oriented in a polyvinyl alcohol-type film, While the existing level of demand has been met, recent higher levels have not been met, requiring further refinement.

Accordingly, an object of the present invention is to provide a polarizing plate capable of suppressing the change in transmittance and maintaining the display quality of the display device even when the display device is exposed in a high temperature, high humidity environment, and a display device having the same and an organic EL display device. Shall be.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, the display apparatus uses the composition containing the photoinitiator which shows a specific base dissociation constant (pKb) and a specific molecular weight for formation of an optically anisotropic layer, and a display apparatus is a high temperature, high humidity environment. Also when exposed under the present conditions, it was found that the change in the transmittance of the polarizing plate can be suppressed and the display quality of the display device can be maintained, thereby completing the present invention.

That is, it discovered that the said subject can be achieved by the following structures.

[1] A polarizing plate having, in this order, an optically anisotropic layer disposed adjacent to the polarizer and the polarizer from the viewer's side,

The polarizer is an iodine-based polarizer in which iodine is adsorbed and oriented on the polyvinyl alcohol-based film,

An optically anisotropic layer is a layer obtained by hardening | curing the composition containing the liquid crystalline compound which has a polymeric group, and a photoinitiator,

The photopolymerization initiator contains the photoinitiator X whose base dissociation constant pKb is 8 or more and whose molecular weight is 240 or more, and content of the photoinitiator X is 60 mass% or more with respect to the total mass of a photoinitiator.

[2] The polarizing plate according to [1], wherein the thickness of the polarizer is 2 to 30 µm.

[3] The optically anisotropic layer is a laminate having a λ / 2 plate and a λ / 4 plate,

From the visual recognition side, it has a polarizer, a (lambda) / 2 plate, and a (lambda) / 4 plate in this order,

In-plane retardation of the λ / 4 plate satisfies the following formula (I),

The polarizing plate as described in [1] or [2] in which the in-plane retardation of (lambda) / 2 plate satisfy | fills following formula (II).

115 nm ≤ Re4 (550) ≤ 155 nm ... (I)

Re2 (550) = 2 × Re4 (550) ± 50nm (II)

Here, in formula (I), Re4 (550) represents in-plane retardation at a wavelength of 550 nm of the λ / 4 plate, and in formula (II), Re2 (550) has a wavelength of 550 nm of the λ / 2 plate. In-plane retardation in is shown.

[4] The polarizing plate according to any one of [1] to [3], in which the optically anisotropic layer contains a discotic liquid crystalline compound.

[5] The polarizing plate according to any one of [1] to [4], which is used for an organic electro luminescence display device.

[6] A display device having the polarizing plate according to any one of [1] to [5].

[7] An organic electro luminescence display device having the polarizing plate according to [5].

According to the present invention, even when the display device is exposed under a high temperature and high humidity environment, a polarizing plate capable of suppressing the change in transmittance and maintaining the display quality of the display device, a display device having the same, and an organic EL display device can be provided. .

BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing which shows an example of embodiment of the polarizing plate of this invention.
It is typical sectional drawing which shows an example of embodiment of the polarizing plate of this invention.
3 is a schematic cross-sectional view showing an example (organic EL display device) of an embodiment of the display device of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Although description of the element | module described below may be made | formed based on typical embodiment of this invention, this invention is not limited to such embodiment.

In addition, the numerical range represented using "-" in this specification means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

In addition, "orthogonal" and "parallel" with respect to an angle mean the range of an exact angle ± 10 degrees, and "equal" and "different" with respect to an angle are judged based on whether the difference is less than 5 degrees. can do.

In addition, in this specification, a "visible light" means a thing of 380-780 nm. In this specification, the measurement wavelength is 550 nm when there is no swelling in particular with respect to the measurement wavelength.

Next, the term used in this specification is demonstrated.

Ground Shaft

In the present specification, the "ground axis" means the direction in which the refractive index becomes maximum in plane. In addition, when it is called the slow axis of an optically anisotropic layer, the slow axis of the whole optically anisotropic layer is intended.

<Re (λ), Rth (λ)>

In this specification, "Re ((lambda))" and "Rth ((lambda))" represent the in-plane retardation in wavelength (lambda), and the retardation of the thickness direction, respectively.

Re ((lambda)) is measured by injecting light of wavelength (lambda) nm to a film normal line direction in KOBRA 21ADH or KOBRA WR (all Oji Keisoku Kiki Co., Ltd. make). In the selection of the measurement wavelength λnm, the wavelength selection filter can be replaced by manual, or the measured value can be converted into a program or the like and measured.

Here, when the film to be measured is represented by the uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.

Rth (λ) is a rotation axis of Re (λ) with an in-plane slow axis (as determined by KOBRA 21ADH or KOBRA WR) as an inclination axis (rotational axis) (when there is no ground axis). And a total of six measurements are made by injecting light having a wavelength of λ nm from the inclined direction in 10 degree steps from the normal direction to 50 degrees on the one side with respect to the film normal direction, and measuring the total of six measured retardation values and the average refractive index. And the KOBRA 21ADH or KOBRA WR based on the input film thickness value.

In the above description, in the case of a film having a direction in which a retardation value becomes zero at a predetermined inclination angle with the in-plane slow axis as the rotation axis from the normal direction, the retardation value at the inclination angle larger than the inclination angle is the symbol. After changing to negative, it calculates in KOBRA 21ADH or KOBRA WR.

In addition, the slow axis is set as the inclination axis (rotation axis) (when there is no ground axis, any direction in the film plane is the rotation axis), and the retardation value is measured from any inclined two directions, and the value and the average refractive index Rth may be calculated from the following equations (1) and (2) based on the hypothesis value and the input peak value.

[Equation 1]

In formula, Re ((theta)) shows the retardation value in the direction which inclined angle (theta) from a normal line direction. In addition, nx represents the refractive index of the slow-axis direction in surface inside, ny represents the refractive index of the direction orthogonal to nx in surface, and nz represents the refractive index of the direction orthogonal to nx and ny. d represents the film thickness of a film.

When the film to be measured cannot be expressed by a single-axis or biaxial refractive ellipsoid, or a film without an optical axis (OPTIC AXIS), Rth (λ) is calculated by the following method.

Rth (λ) is 10 degrees from -50 degrees to +50 degrees with respect to the film normal direction with Re (λ) as the inclination axis (rotation axis) as the in-plane slow axis (as determined by KOBRA 21ADH or KOBRA WR). In each step, 11 pieces of light having a wavelength of λ nm are incident from the inclined direction, and calculated by KOBRA 21ADH or KOBRA WR on the basis of the measured retardation value, the assumption of the average refractive index, and the input film thickness value.

In the above measurement, the hypothetical value of the average refractive index may be a polymer handbook (JOHN WILEY & SONS, INC) and values of catalogs of various optical films. The unknown value of the average refractive index can be measured with an Abbe refractometer. The value of the average refractive index of the main optical film is illustrated below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethylmethacrylate (1.49), polystyrene (1.59). By inputting the assumption values and film thicknesses of these average refractive indices, nx, ny, and nz are calculated in KOBRA 21ADH or KOBRA WR. Nz = (nx-nz) / (nx-ny) is further calculated by this calculated nx, ny, and nz.

<Base dissociation constant (pKb)>

In this specification, the "base dissociation constant (pKb)" of a photoinitiator refers to pKb in 25 degreeC of water temperature, and is one of the indicators for showing the intensity | strength of a base quantitatively, and is synonymous with basicity constant.

Base dissociation constants (pKb) are described in A. E. Martell, R. M. Smith, "Critical Stability Constants", Vol. After calculating acid dissociation constant (pKa) by the method described in 1-3, Plenum Press (1974, 1975, 9177), it can obtain | require from the formula of pKb = 14.0-pKa.

[Polarizing Plate]

The polarizing plate of this invention is a polarizing plate which has an optically anisotropic layer arrange | positioned adjacent to a polarizer and a polarizer in this order from the visual recognition side.

Moreover, the polarizer which the polarizing plate of this invention has is an iodine system polarizer in which iodine is adsorption-oriented to a polyvinyl alcohol-type film.

Moreover, the optically anisotropic layer which the polarizing plate of this invention has is a layer obtained by hardening | curing the composition containing the liquid crystalline compound which has a polymeric group, and a photoinitiator, This photoinitiator has a base dissociation constant pKb of 8 or more, and also has a molecular weight It contains the photoinitiator X which is 240 or more, and content of the photoinitiator X is 60 mass% or more with respect to the total mass of a photoinitiator.

By having such a structure, even when a display apparatus is exposed in a high temperature, high humidity environment, it becomes a polarizing plate which can suppress the change of transmittance and can maintain the display quality of a display apparatus.

Although this is not clear in detail, the present inventors guess as follows.

First, the transmittance of a polarizing plate increases and the display quality of a display device is inferior from the result of the comparative example mentioned later, and exists at the time of formation of an optically anisotropic layer by using the photoinitiator with strong basicity, ie, small pKb. Alternatively, a phenomenon in which the photopolymerization initiator remaining after formation penetrates or diffuses into adjacent polarizers in a high temperature and high humidity environment, causes the boric acid crosslinking of the polarizer to dissociate. Moreover, about the cause of inferior display quality of a display apparatus, by using the photoinitiator with a small molecular weight, hardening of the liquid crystalline molecule in an optically anisotropic layer does not fully advance, but the orientation may become unstable, and the phenomenon that a haze may be considered. .

For this reason, in this invention, photopolymerization which fully advances hardening and invades or diffuses into a polarizer by forming an optically anisotropic layer using the composition containing the photoinitiator which shows a specific base dissociation constant (pKb) and a specific molecular weight is carried out. Since dissociation of boric acid bridge | crosslinking by an initiator could be suppressed, even when a display apparatus is exposed in high temperature, high humidity environment, it can be considered that the change of transmittance | permeability was suppressed and the display quality of the display apparatus was maintained.

Next, after demonstrating the whole structure of the polarizing plate of this invention using FIG. 1 and FIG. 2, the structure of each part is demonstrated in detail.

FIG. 1 and FIG. 2 are typical sectional drawing which shows an example of embodiment of the polarizing plate of this invention, respectively.

As shown to FIG. 1 and FIG. 2, the polarizing plates 10 and 20 both have the polarizer 12 and the optically anisotropic layer 14 in this order from the visual recognition side.

Moreover, as shown to FIG. 1 and FIG. 2, you may have the polarizer protective film 11 in the visual recognition side of the polarizer 12, and the adhesive layer 13 is provided between the polarizer 12 and the optically anisotropic layer 14. FIG. You may have it.

Moreover, the polarizing plate 20 shown in FIG. 2 has the (lambda) / 2 board 15, the adhesive layer 17, and the (lambda) / 4 board 16 as the optically anisotropic layer 14. Moreover, as shown in FIG.

[Polarizer]

The iodine type polarizer is used for the polarizer which the polarizing plate of this invention has. The iodine-based polarizer is iodine adsorbed on a polyvinyl alcohol-based film.

Such an iodine-based polarizer is obtained by, for example, at least performing a dyeing step, a crosslinking step and an stretching step on a polyvinyl alcohol-based film. In addition, each treatment bath of a dyeing bath, a crosslinking bath, and an extending | stretching bath is used for a dyeing process, a crosslinking process, and an extending process, and the treatment liquid (aqueous solution etc.) according to each process is used for each of these treatment baths.

Moreover, as another manufacturing method of such an iodine type polarizer, the method as described in Paragraph [0017]-[0042] of Unexamined-Japanese-Patent No. 2013-097170 is mentioned, for example, The content of these paragraphs is It shall be incorporated in this specification.

In the present invention, the thickness of the polarizer is not particularly limited, but from the viewpoint of excellent handleability and excellent optical properties, 2 to 30 µm is preferable, 2 to 25 µm are more preferable, and 5 to 20 µm are more preferable. .

Moreover, in this invention, although the single plate transmittance of a polarizer is not specifically limited, It is preferable that it is more than 43%, and it is more preferable that it is 44% or more and less than 50% because the effect which suppresses the change of the transmittance | permeability of a polarizing plate is expressed more. .

Here, the single-plate transmittance of a polarizer is measured at wavelength 550nm on 25 degreeC and 60% of relative humidity using VAP-7070 (made by Nippon Bunko Corporation), and uses the average value of 10 measurements.

[Optical anisotropic layer]

The optically anisotropic layer of the polarizing plate of this invention is arrange | positioned adjacent to the polarizer mentioned above, and hardens the composition (henceforth "the composition for optically anisotropic layer formation") containing the liquid crystalline compound and photoinitiator which has a polymeric group. It is a layer obtained by making it become a single layer structure, and the structure (laminated body) which laminated | stacked multiple layers may be sufficient.

Here, in this specification, the aspect in which the polarizer and the optically anisotropic layer are "adjacent" means that the polarizer and the optically anisotropic layer are in direct contact with each other, and as shown in FIG. 1 and FIG. The aspect which contact | connects through an adhesive layer or an adhesive bond layer is said. In addition, when an optically anisotropic layer is a laminated body, the polarizer and at least one layer (for example, 2 / (lambda) plate) of an optically anisotropic layer should just adjoin.

Below, the photoinitiator, the liquid crystalline compound, and arbitrary components which the composition for optically anisotropic layer formation contain are demonstrated.

<Photoinitiator>

As a photoinitiator, for example, acetophenones, benzoin, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds And disulfide compounds, fluoroamine compounds, aromatic sulfoniums, ropin dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like.

Moreover, Paragraph [0133]-[0151] of Unexamined-Japanese-Patent No. 2009-098658, "The latest UV curing technique" {Kijutsu Joho Kyoikai} (1991), p. 159, and "Ultraviolet Curing System" by Kato Kiyomi (first year of Heisei, issued by Sogo Kijutsu Center), p. The various examples described in 65-148 can also be mentioned.

Commercially available photo cleavage type photopolymerization initiators include "Irgacure 127 (pKB: 13, Molecular Weight: 340)", "Irgacure 184 (pKB: 17, Molecular Weight: 204)" manufactured by BASF, "Irgacure 819" (pKB: 24, molecular weight: 419) "," irgacure 907 (pKB: 5.6, molecular weight: 279) "," irgacure 369 (pKB: 5.3, molecular weight: 367) "," irgacure 379 (pKB) : 5.4, molecular weight: 381) "," Irgacure 2959 (pKB: 14, molecular weight: 224) "," Darocure 1173 (pKB: 16, molecular weight: 164) "and the like; "Kayacure-DETX-S", "Kayacure-BP-100", "Kayacure-BDMK", "Kayacure-CTX", "Kayacure-BMS" and "Kayacure" made by Nippon Kayaku Co., Ltd. -2-EAQ "," Kayacure-ABQ "," Kayacure-CPTX "," Kayacure-EPD "," Kayacure-ITX "," Kayacure-QTX "," Kayacure-BTC "," Kayaure Cure-MCA "and the like; And Sacommer's "Esacure (KIP100F, KB1, EB3, BP, X33, KTO46, KT37, KIP150, TZT)" and the like, and combinations thereof are preferable examples.

In the present invention, a photopolymerization initiator (photopolymerization initiator X) having a base dissociation constant (pKb) of 8 or more and a molecular weight of 240 or more is used among the photoinitiators exemplified above.

It is preferable that it is 8-50, and, as for the base dissociation constant (pKb) of such photoinitiator X, it is more preferable that it is 15-30.

Moreover, it is preferable that it is 240-1000, and, as for the molecular weight of photoinitiator X, it is more preferable that it is 300-600.

Moreover, in this invention, content in the composition for optically anisotropic layer formation of photoinitiator X is 60 mass% or more with respect to the total mass of the photoinitiator containing photoinitiator X, It is preferable that it is 65 mass% or more, 80 It is more preferable that it is more than mass%, and it is more preferable that it is an aspect which used only the photoinitiator X as 100 mass%, ie, a photoinitiator.

Moreover, in this invention, it is preferable that it is 0.01-20 mass% with respect to the total solid of the composition for optically anisotropic layer formation, and, as for the total mass of the photoinitiator containing photoinitiator X, it is more preferable that it is 0.5-5 mass%. Do.

<Liquid crystalline compound>

The liquid crystalline compound which the composition for optically anisotropic layer formation contains is a liquid crystalline compound which has a polymeric group.

Generally, a liquid crystalline compound can be classified into a rod-shaped type and a disk-shaped type from the shape. There are also low molecular and high polymer types, respectively. A polymer generally refers to a polymer having a degree of polymerization of 100 or more (polymer physics-phase transition dynamics, Toi Masao, p. 2, Iwanami Shoten, 1992).

In the present invention, any liquid crystal compound may be used, but it is preferable to use a rod-like liquid crystal compound (hereinafter abbreviated as "CLC") or a discotic liquid crystal compound (hereinafter abbreviated as "DLC"). It is more preferable to use a discotic liquid crystalline compound. Moreover, you may use 2 or more types of rod-like liquid crystalline compounds, 2 or more types of discotic liquid crystalline compounds, or a mixture of a rod-like liquid crystalline compound and a discotic liquid crystalline compound.

In this invention, although the liquid crystalline compound which has a polymeric group is used for immobilization of the liquid crystalline compound mentioned above, it is more preferable that a liquid crystalline compound has two or more polymeric groups in 1 molecule. Moreover, when a liquid crystalline compound is a mixture of two or more types, it is preferable that at least 1 type of liquid crystalline compound has a polymerizable group which is two or more in 1 molecule. Moreover, after a liquid crystalline compound is fixed by superposition | polymerization, it is not necessary to show liquid crystalline any more.

Moreover, the kind in particular of polymerizable group is not restrict | limited, The functional group which can carry out addition polymerization reaction is preferable, and a polymerizable ethylenically unsaturated group or a ring polymerizable group is preferable. More specifically, a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, etc. are mentioned preferably, A (meth) acryloyl group is more preferable. In addition, a (meth) acryloyl group is the notation which means a methacryloyl group or acryloyl group.

As a rod-shaped liquid crystalline compound, the thing of Claim 1 of Unexamined-Japanese-Patent No. 11-513019, and Paragraph [0026]-[0098] of Unexamined-Japanese-Patent No. 2005-289980 can be used preferably, For example, discotic liquid crystalline As the compound, for example, paragraphs [0020] to [0067] of JP 2007-108732 A and paragraphs [0013] to [0108] of JP 2010-244038A can be preferably used. It is not limited.

<Polymeric Monomer>

The composition for optically anisotropic layer formation may contain the polymerizable monomer from the point of the uniformity of a coating film and the intensity | strength of a film | membrane.

A radically polymerizable or cationically polymerizable compound is mentioned as a polymerizable monomer. Preferably, it is a polyfunctional radically polymerizable monomer and it is preferable that it is copolymerizable with the liquid crystalline compound containing said polymeric group. For example, the thing of Paragraph [0018]-[0020] of Unexamined-Japanese-Patent No. 2002-296423 can be mentioned.

It is preferable that it is 1-50 mass% with respect to the total mass of a liquid crystalline compound, and, as for the addition amount of a polymerizable monomer, it is more preferable that it is 2-30 mass%.

<Surfactant>

The composition for optically anisotropic layer formation may contain surfactant from the point of the uniformity of a coating film, and the strength of a film | membrane.

As a surfactant, a conventionally well-known compound is mentioned, Especially a fluorine-type compound is preferable. Specifically, for example, the compounds described in paragraphs [0028] to [0056] of JP 2001-330725 and the compounds described in paragraphs [0069] to [0126] of JP 2003-295212 are mentioned. Can be.

<Solvent>

The composition for optically anisotropic layer formation may contain the solvent (especially an organic solvent).

As the organic solvent, for example, an alcohol solvent and a ketone solvent are preferably used.

Specifically, acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexane, 2-heptanone, 4-heptanone, methyl isopropyl ketone, ethyl isopropyl ketone, diisopropyl ketone, Methyl isobutyl ketone, methyl t-butyl ketone, diacetyl, acetyl acetone, acetonyl acetone, diacetone alcohol, methyl oxide, chloroacetone, cyclopentanone, cyclohexanone, acetophenone, etc. are mentioned. Among these, methyl ethyl ketone and methyl isobutyl ketone are preferable. These solvents may be used alone, or may be used by mixing in any mixing ratio.

<Orientation agent>

The composition for optically anisotropic layer formation contains various orientation agents, such as a vertical alignment promoter, such as a polarizer interface side vertical aligning agent and an air interface side vertical aligning agent, a horizontal alignment promoter, such as a polarizer interface side horizontal aligning agent and an air interface side horizontal aligning agent. You may be.

The formation method of the optically anisotropic layer using the composition for optically anisotropic layer formation which has such a component is not specifically limited, For example, the composition for optically anisotropic layer formation is apply | coated to a predetermined board | substrate (including a board | substrate), and a coating film It can form by forming hardening process and performing hardening process (irradiation of ultraviolet rays (light irradiation process) or heat processing) with respect to the obtained coating film. Moreover, you may use the orientation film mentioned later as needed.

Application | coating of the composition for optically anisotropic layer formation can be performed by a well-known method (for example, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

In this invention, it is preferable that an optically anisotropic layer satisfy | fills following formula (III) from a viewpoint of making the polarizing plate of this invention function as a circularly polarizing plate.

100≤Re (550) ≤180nm ... (III)

Here, in Formula (III), Re (550) represents in-plane retardation in wavelength 550nm of an optically anisotropic layer.

In addition, in this specification, "a circularly polarizing plate" is used by the meaning containing both a long circularly polarizing plate and the circularly polarizing plate cut to the size contained in a display apparatus, unless there is particular description. In addition, the term "foundation" as used herein includes "punching" and "cutting".

In the present invention, the optically anisotropic layer is preferably a laminate having a λ / 2 plate and a λ / 4 plate because it functions as a λ / 4 plate in a wide wavelength range and can be used more suitably as a circularly polarizing plate. .

<λ / 2 edition>

The λ / 2 plate refers to an optically anisotropic layer in which the in-plane retardation Re (λ) at a specific wavelength λnm satisfies Re (λ) = λ / 2. In addition, this expression should just be achieved in any wavelength (for example, 550 nm) in visible region.

In this invention, it is preferable that it is 205-275 nm, and, as for in-plane retardation Re (550) in wavelength 550nm of (lambda) / 2 board, it is more preferable that it is 215-265 nm.

In this invention, (lambda) / 2 board can be formed by the formation method mentioned above using the composition for optically anisotropic layer formation mentioned above, Among the above-mentioned liquid crystalline compounds, a rod-shaped liquid crystalline compound or a discotic liquid crystalline compound It is preferable to use, and it is more preferable to use a discotic liquid crystalline compound.

Moreover, in this invention, although the thickness of (lambda) / 2 board in particular is not restrict | limited, 0.5-10 micrometers is preferable and 0.5-5 micrometers is more preferable for the reason that thickness reduction of a display apparatus becomes easy.

In addition, the said thickness intends average thickness, measures the thickness of arbitrary 5 places of (lambda) / 2 board, and arithmically averages them.

<λ / 4 edition>

A λ / 4 plate is a plate having a function of converting linearly polarized light of a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light), and the in-plane retardation Re (λ) at the specific wavelength λnm is Re (λ. refers to an optically anisotropic layer that satisfies) = λ / 4. In addition, this expression should just be achieved in any wavelength (for example, 550 nm) in visible region.

In this invention, it is preferable that it is 100-160 nm, and, as for in-plane retardation Re (550) in wavelength 550nm of (lambda) / 4 plate, it is more preferable that it is 115-155 nm.

In this invention, (lambda) / 4 plate can be formed by the formation method mentioned above using the composition for optically anisotropic layer formation mentioned above, Among the above-mentioned liquid crystalline compounds, a rod-shaped liquid crystalline compound or a discotic liquid crystalline compound is formed. It is preferable to use, and it is more preferable to use a discotic liquid crystalline compound.

In addition, in this invention, although the thickness of (lambda) / 4 board is not restrict | limited, 0.5-10 micrometers is preferable and 0.5-5 micrometers is more preferable from the reason which becomes easy to thin the display apparatus.

In addition, the said thickness intends average thickness, measures the thickness of arbitrary 5 places of (lambda) / 4 board, and arithmetic averages them.

In this invention, when using the laminated body which has above-mentioned (lambda) / 2 board and (lambda) / 4 board as an optically anisotropic layer, it is preferable to have a (lambda) / 2 board and a (lambda) / 4 board in this order from a visual recognition side. . The angle between the in-plane slow axis of the λ / 4 plate and the in-plane slow axis of the λ / 2 plate is preferably 60 ° ± 10 °.

In addition, the in-plane retardation of the λ / 4 plate satisfies the following formula (I), and the in-plane retardation of the λ / 2 plate gives the following formula (II) It is desirable to satisfy.

115 nm ≤ Re4 (550) ≤ 155 nm ... (I)

Re2 (550) = 2 × Re4 (550) ± 50nm (II)

Here, in formula (I), Re4 (550) represents in-plane retardation at a wavelength of 550 nm of the λ / 4 plate, and in formula (II), Re2 (550) has a wavelength of 550 nm of the λ / 2 plate. In-plane retardation in is shown.

Moreover, in this invention, when using the laminated body which has above-mentioned (lambda) / 2 board and (lambda) / 4 board as an optically anisotropic layer, in addition to the aspect which the above-mentioned (lambda) / 2 board and (lambda) / 4 board directly contact, The aspect containing other layers other than a (lambda) / 2 board and a (lambda) / 4 board may be sufficient in the range which does not impair an effect.

As another layer, the adhesive layer or adhesive bond layer provided between a (lambda) / 2 plate and (lambda) / 4 board, the alignment film used when forming an optically anisotropic layer, etc. are mentioned, for example.

<Adhesive layer, adhesive layer>

The pressure-sensitive adhesive and the adhesive which can be used in the present invention are not particularly limited, and a pressure-sensitive adhesive (for example, an acrylic pressure-sensitive adhesive or the like) or an adhesive (for example, an ultraviolet curable adhesive or a polyvinyl alcohol-based adhesive) can be used.

Moreover, as an adhesive and adhesive which can be used for this invention, Paragraph [0100]-[0115] of Unexamined-Japanese-Patent No. 2011-037140, Paragraph [0155]-[0171] of Unexamined-Japanese-Patent No. 2009-292870, etc. are described, for example. A pressure-sensitive adhesive can be used.

<Alignment Film>

An oriented film is a layer which has a function which defines the orientation direction of a liquid crystalline compound, and generally has a polymer as a main component.

As a polymer material for oriented films, many documents have description and a lot of commercial items can be obtained. As the polymer material to be used, polyvinyl alcohol or polyimide and derivatives thereof are preferable. In particular, modified or unmodified polyvinyl alcohol is preferable. Regarding the alignment film usable in the present invention, modified polyvinyl alcohol described in page 43, line 24 to page 49, line 8 of WO01 / 88574A1 and paragraphs [0071] to [0095] of Japanese Patent Publication No. 3907735 can be referred to. In addition, a well-known rubbing process is given to an orientation film normally. That is, it is preferable that the alignment film is a rubbing alignment film which is usually subjected to a rubbing treatment.

As above-mentioned, the thickness of an oriented film should just be 20 micrometers or less, Especially, it is preferable that it is 0.01-10 micrometers, It is more preferable that it is 0.01-1 micrometer, It is more preferable that it is 0.01-0.5 micrometer.

[Other floors]

The polarizing plate of this invention may be equipped with other layers other than the polarizer and optically anisotropic layer mentioned above in the range which does not impair the effect of this invention.

<Polarizer protective film>

As for the polarizing plate of this invention, the polarizer protective film may be arrange | positioned on the surface (surface on the opposite side to the side in which the optically anisotropic layer was provided) on the visual side of the polarizer mentioned above.

Specifically as a polarizer protective film, For example, thermoplastics, such as a cellulose acylate type film, a (meth) acrylic-type resin film, a cycloolefin resin film, a polyester resin film, a polycarbonate resin film, and a polyolefin resin film, are mentioned. And a resin film.

In addition, (meth) acrylic-type resin is a concept containing both methacryl-type resin and acrylic resin, and also contains the derivative of acrylate / methacrylate, especially the (co) polymer of acrylate ester / methacrylate ester. . Moreover, (meth) acrylic-type resin contains the (meth) acrylic-type polymer which has ring structure in main chain other than methacryl-type resin and acrylic resin, The polymer which has a lactone ring, the maleic anhydride type polymer which has a succinic anhydride ring, anhydrous The polymer which has a glutaric acid ring, and a glutarimide ring containing polymer are included.

Among these, it is preferable that it is a cellulose acylate type film and a (meth) acrylic resin type film from a viewpoint of workability and optical performance.

As a cellulose acylate type film which can be used suitably as a polarizer protective film, various well-known things can be used, For example, the thing of Unexamined-Japanese-Patent No. 2012-076051 can be used.

Moreover, as a (meth) acrylic resin type film, various well-known things can be used, Specifically, For example, the acrylic film of Unexamined-Japanese-Patent No. 2010-079175, the paragraph of [0032]-[0063] The lactone ring-containing polymer described in paragraphs [0017] to [0107] of 2009-98605 can be suitably employed.

It is preferable that it is 5 micrometers-40 micrometers, and, as for the thickness of a polarizer protective film, from a viewpoint of thickness reduction of a polarizing plate, it is more preferable that it is 10 micrometers-30 micrometers.

It is preferable that it is 60 g / m <^2> / 24h or more, as for the water vapor transmission rate of a polarizer protective film, it is more preferable that it is 105 g / m <^2> / 24h or more, and it is still more preferable that it is 110-1000 g / m <^2> / 24h.

The water vapor transmission rate here is the amount of water vapor which passed in 24 hours under conditions of 40 degreeC of temperature and 90% of a relative humidity according to the method described in "The moisture vapor permeability test method (cup method)" of JIS Z 0208: 1976. / m ² / 24h).

[Display device]

The display device of the present invention is a display device having the polarizing plate of the present invention described above.

Since the polarizing plate of this invention is used suitably for anti-reflective use, an organic electroluminescent display, a liquid crystal display, a plasma display panel, a cathode ray tube display, etc. are mentioned as a display apparatus of this invention, for example. It is preferable that it is an organic electroluminescence display among these.

Hereinafter, the case of the organic electroluminescence display containing the polarizing plate of this invention is demonstrated in detail.

[Organic EL display device]

The organic electroluminescence display which is a suitable aspect of the display apparatus of this invention has a polarizing plate which functions as a circularly polarizing plate among the polarizing plates of this invention mentioned above. Usually, a circularly polarizing plate is provided on the organic electroluminescent panel of an organic electroluminescence display. More specifically, as shown in FIG. 3, the organic EL display device 30 includes at least an organic EL panel 32 and a polarizing plate 20. In addition, the structure of the polarizing plate 20 is as showing in FIG. 2 except providing the adhesive 18 used for adhesion | attachment with the organic EL panel 32. As shown in FIG.

An organic EL panel is a member in which a plurality of organic compound thin films including a light emitting layer or a light emitting layer are formed between a pair of electrodes of an anode and a cathode, and in addition to a light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. And a protective layer, and each of these layers may have a different function. Various materials can be used for formation of each layer, respectively.

An anode supplies holes to a hole injection layer, a hole transport layer, a light emitting layer, and the like, and a metal, an alloy, a metal oxide, an electrically conductive compound, a mixture thereof, or the like can be used, and preferably a material having a work function of 4 eV or more. Specific examples thereof include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO), or metals such as gold, silver, chromium, and nickel, and mixtures or laminates of these metals and conductive metal oxides. Inorganic conductive materials such as water, copper iodide, copper sulfide, organic conductive materials such as polyaniline, polythiophene, polypyrrole, and laminates of these and ITO; and the like, and preferably conductive metal oxides, In particular, ITO is preferable in terms of productivity, high conductivity, transparency, and the like. Although the film thickness of an anode can be suitably selected according to a material, the thing of the range of 10 nm-5 micrometers is preferable normally, More preferably, it is 50 nm-1 micrometer, More preferably, it is 100 nm-500 nm.

Example

The present invention will be described in more detail based on Examples. The materials, usage amounts, ratios, treatment contents, treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be interpreted limitedly by the Example shown below.

EXAMPLE 1

(1) Preparation of cellulose acylate film (T1)

(Preparation of cellulose acetate solution A-1)

The following composition was put into the mixing tank, it stirred while heating, each component was dissolved, and the cellulose acetate solution A-1 was prepared.

----------------------------------------------

Composition of Cellulose Acetate Solution A-1

----------------------------------------------

100 parts by mass of cellulose acetate (acetylation degree 2.86)

320 parts by mass of methylene chloride (first solvent)

83 parts by mass of methanol (second solvent)

1-butanol (third solvent) 3 parts by mass

7.6 parts by mass of triphenyl phosphate

Biphenyl diphenyl phosphate 3.8 parts by mass

----------------------------------------------

(Preparation of Matte Dispersion B-1)

The following composition was put into the dispersing machine, it stirred, each component was melt | dissolved, and mat dispersion liquid B-1 was prepared.

-------------------------------------------------

Composition of Mat Dispersion B-1

-------------------------------------------------

Silica particle dispersion (average particle size 16 nm)

AEROSIL R972 (made by Nippon Aerosil Co., Ltd.) 10.0 parts by mass

Methylene chloride 72.8 parts by mass

3.9 parts by mass of methanol

0.5 parts by mass of butanol

Cellulose acetate solution A-1 10.3 parts by mass

-------------------------------------------------

(Preparation of ultraviolet absorbent solution C-1)

The following composition was put into the other mixing tank, it stirred while heating, each component was dissolved, and the ultraviolet absorber solution C-1 was prepared.

----------------------------------------------

Composition of Ultraviolet Absorber Solution C-1

----------------------------------------------

10.0 parts by mass of ultraviolet absorbent (UV-1)

10.0 parts by mass of ultraviolet absorbent (UV-2)

Methylene chloride 55.7 parts by mass

Methanol 10 parts by mass

Butanol 1.3 parts by mass

12.9 parts by mass of cellulose acetate solution A-1

----------------------------------------------

[Formula 1]

(Production of a cellulose acylate film)

Ultraviolet absorbers (UV-1) and UV absorbers (UV-2) are 1.0 per 100 parts by mass of cellulose acylate, respectively, in a mixture containing 94.6 parts by mass of cellulose acetate solution A-1 and 1.3 parts by mass of matt dispersion B-1. Ultraviolet absorber solution C-1 was added so that it might be a mass part, it stirred sufficiently, heating, each component was dissolved, and dope was prepared.

The prepared dope was heated at 30 degreeC, and it casted on the mirror surface stainless steel support body which is a drum of diameter 3m through a casting die. The surface temperature of the support was set to -5 ° C, and the coating width was 1470 mm. The flexible dope film was dried by spraying dry air at 34 ° C. on a drum at 150 m ³ / min, and peeled from the drum in a state where the residual solvent was 150%. At the time of peeling, extending | stretching of 15% was performed in a conveyance direction (length direction).

Then, it conveys, holding both ends of the film in the width direction (direction orthogonal to a stretching direction) with a pen tenter (pen tenter of FIG. 3 of Unexamined-Japanese-Patent No. 4-1009), and extending | stretching process to a width direction Did not do.

Furthermore, it dried further by conveying between the rolls of a heat processing apparatus, and manufactured the cellulose acylate film (T1).

The residual solvent amount of the produced elongate cellulose acylate film (T1) was 0.2%, the thickness was 60 µm, and Re and Rth at 550 nm were 0.8 nm and 40 nm, respectively.

(2) Preparation of Cellulose Acylate Film (T2)

(Production of core layer cellulose acylate dope)

The following composition was put into the mixing tank, it stirred, and each component was dissolved, and the core layer cellulose acetate solution (core layer cellulose acylate dope) was prepared.

-------------------------------------------------- -

100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.88.

10 parts by mass of ester oligomer A

4 parts by mass of the following polarizer durability improving agent

2 parts by mass of an ultraviolet absorber (the above UV-2)

430 parts by mass of methylene chloride (first solvent)

64 parts by mass of methanol (second solvent)

-------------------------------------------------- -

TABLE 1

Polarizer durability improver

[Formula 2]

(Production of outer layer cellulose acylate dope)

10 mass parts of the following mat agent solutions were added to 90 mass parts of core layer cellulose acylate dope, and the outer layer cellulose acetate solution (outer layer cellulose acylate dope) was prepared.

-------------------------------------------------

Silica particles with an average particle size of 20 nm

2 parts by mass of AEROSIL R972 (made by Nippon Aerosol)

Methylene chloride (first solvent) 76 parts by mass

11 parts by mass of methanol (second solvent)

1 part by mass of the core layer cellulose acylate dope

-------------------------------------------------

(Production of a cellulose acylate film)

The core layer cellulose acylate dope and the outer layer cellulose acylate dope on both sides were cast on the drum of 20 degreeC simultaneously from oil research. It peeled in the state of a solvent content rate of about 20 mass%, fixed both ends of the width direction of a film with a tenter clip, and dried while extending | stretching 1.1 times in the horizontal direction in the state which the residual solvent is 3 to 15%. Then, it conveyed further between the rolls of a heat processing apparatus, and further dried and produced the cellulose acylate film (T2) of thickness 25micrometer.

(3) Fabrication of phase difference plate F1

(Alkaline saponification treatment)

After passing the above-mentioned cellulose acylate film (T1) through a dielectric heating roll having a temperature of 60 ° C. and raising the film surface temperature to 40 ° C., an alkali solution having a composition shown below on the band surface of the film is used as a bar coater. It applied at 14 ml / m <^2> of coating amounts, and conveyed for 10 second under the steam type far-infrared heater made from Noritake Co., Ltd. heated at 110 degreeC.

Subsequently, 3 ml / m <^{2> of} pure waters were apply | coated similarly using the bar coater.

Subsequently, washing with a fountain coater and dehydration with an air knife were repeated three times, and then conveyed and dried for 10 seconds in a 70 ° C drying zone to prepare an alkali saponified cellulose acylate film.

-------------------------------------------------

Alkaline solution composition

-------------------------------------------------

4.7 parts by mass of potassium hydroxide

15.8 parts by mass of water

63.7 parts by mass of isopropanol

Surfactant SF-1: C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₂₀ H 1.0 parts by mass

Propylene glycol 14.8 parts by mass

-------------------------------------------------

(Formation of alignment film)

The alignment film coating liquid (A) of the following composition was apply | coated continuously to the wire bar of # 14 to the surface which gave alkali saponification process of a cellulose acylate film (T1). It dried for 60 second by the warm air of 60 degreeC, and 120 second by the warm air of 100 degreeC, and produced the oriented film.

------------------------------------------------

Composition of alignment film coating liquid

------------------------------------------------

10 parts by mass of the following polyvinyl alcohol

371 parts by mass of water

119 parts by mass of methanol

0.5 parts by mass of glutaraldehyde (crosslinking agent)

0.175 parts by mass of citric acid ester (manufactured by Sankyo Chemical Industries, Ltd.)

------------------------------------------------

Polyvinyl alcohol

[Formula 3]

(Formation of the first optically anisotropic layer (H))

The rubbing treatment was continuously performed on the produced alignment film. At this time, the longitudinal direction and the conveyance direction of the elongate film were parallel, and the angle formed by the film longitudinal direction and the rotation axis of the rubbing roller was 75 ° (the film width direction was 0 °, the film length direction was 90 °, and the alignment film The rotation axis of the rubbing roller is 165 ° when observed from the side and the clockwise direction is represented by a positive value based on the film width direction.

The optically anisotropic layer coating liquid (A) containing the discotic liquid crystal compound of the following composition was apply | coated continuously to the wire bar of # 5.0 on the produced oriented film, and the retardation plate (F1) was produced. The conveyance speed (V) of the film was 26 m / min. For drying the solvent of the coating liquid and aging of the discotic liquid crystal compound, heating is performed for 90 seconds with warm air at 130 ° C. for 60 seconds followed by 60 seconds with warm air at 100 ° C., and UV irradiation is performed at 80 ° C. to align the liquid crystal compound. Immobilized. The thickness of the first optically anisotropic layer (H) was 2.0 µm, and Re at 550 nm was 250 nm. The average inclination angle with respect to the film surface of the disk surface of a DLC compound was 90 degrees, and it confirmed that the DLC compound was orientating perpendicularly with respect to the film surface.

Moreover, the angle of the slow axis of the 1st optically anisotropic layer H is parallel to the rotation axis of a rubbing roller, and when it sees the width direction of a film as 0 degree (90 degree of length directions), it looked at from the 1st optically anisotropic layer H side. The slow axis was 165 °.

Moreover, the cellulose acylate film (T1) and the alignment film were in close contact with each other, and the first optically anisotropic layer (H) could be peeled from the alignment film.

-------------------------------------------------- -------

Composition of Optically Anisotropic Layer Coating Liquid (A)

-------------------------------------------------- -------

Discotic liquid crystal-1 80 parts by mass

Discotic liquid crystal-2 20 parts by mass

Orientation film interfacial alignment agent-1 2.0 parts by mass

0.21 parts by mass of fluorine-containing compound (FP-1)

0.05 parts by mass of fluorine-containing compound (FP-2)

0.10 parts by mass of fluorine-containing compound (FP-3)

5 parts by mass of modified trimethylolpropane triacrylate

Photopolymerization initiator Irgacure 819

  (pKB: 24, molecular weight: 419, manufactured by BASF Corporation) 4.0 parts by mass

200 parts by mass of methyl ethyl ketone

-------------------------------------------------- -------

Discotic LCD-1

[Formula 4]

Discotic LCD-2

[Formula 5]

Alignment layer interface alignment agent-1

[Formula 6]

Fluorine-containing compound (FP-1)

[Formula 7]

Fluorine-containing compound (FP-2)

[Formula 8]

Fluorine-containing compound (FP-3)

[Formula 9]

(4) Fabrication of phase difference plate F2

(Formation of Second Optically Anisotropic Layer Q)

Alkali saponification was performed to the cellulose acylate film (T1) by the same method as the retardation plate (F1), and the alignment film was formed.

Next, the rubbing process was performed continuously to the produced oriented film. At this time, the longitudinal direction and the conveyance direction of the elongate film were parallel, and the angle formed by the film longitudinal direction and the rotation axis of the rubbing roller was 75 ° (the film width direction was 0 °, the film length direction was 90 °, and the alignment film When observed from the side and the clockwise direction is defined as a positive value with respect to the film width direction, the rotation axis of the rubbing roller is 15 °).

The optically anisotropic layer coating liquid (B) containing the discotic liquid crystal compound of the following composition was apply | coated continuously to the wire bar of # 2.4 on the produced oriented film, and the retardation plate (F2) was produced. The conveyance speed (V) of the film was 26 m / min. For drying the solvent of the coating liquid and aging of the discotic liquid crystal compound, heating is performed for 90 seconds with warm air at 130 ° C. for 60 seconds followed by 60 seconds with warm air at 100 ° C., and UV irradiation is performed at 80 ° C. to align the liquid crystal compound. Immobilized. The thickness of the 2nd optically anisotropic layer Q was 0.96 micrometer, and Re in 550 nm was 120 nm. The average inclination angle with respect to the film surface of the disk surface of a DLC compound was 90 degrees, and it confirmed that the DLC compound was orientating perpendicularly with respect to the film surface.

Moreover, the angle of the slow axis of the 2nd optically anisotropic layer Q is orthogonal to the rotational axis of a rubbing roller, and when the width direction of a film makes 0 degree (90 degree of length directions), it looked at from the 2nd optically anisotropic layer Q side. The slow axis was 105 degrees.

Moreover, the cellulose acylate film (T1) and the alignment film were in close contact with each other, and the second optically anisotropic layer (Q) could be peeled from the alignment film.

-------------------------------------------------- --------

Composition of Optically Anisotropic Layer Coating Liquid (B)

-------------------------------------------------- --------

Discotic liquid crystal-1 80 parts by mass

Discotic liquid crystal-2 20 parts by mass

1.0 mass parts of aligning film interface aligning agent-1

0.20 parts by mass of fluorine-containing compound (FP-1)

0.10 parts by mass of fluorine-containing compound (FP-2)

0.10 parts by mass of fluorine-containing compound (FP-3)

10 parts by mass of modified trimethylolpropane triacrylate

Photopolymerization initiator Irgacure 819

  (pKB: 24, molecular weight: 419, manufactured by BASF Corporation) 5.0 parts by mass

200 parts by mass of methyl ethyl ketone

-------------------------------------------------- --------

(5) fabrication of polarizer

The polyvinyl alcohol (PVA) film of 60 micrometers in thickness was immersed in 25 degreeC pure water for 60 second, and it extended | stretched by 1.30 times after swelling process.

After immersing and dyeing the obtained film in the dyeing solution containing 0.2 mass part of iodine and 5 mass parts of potassium iodide for 30 second with respect to 100 mass parts of water, for 100 mass parts of water, It extended | stretched 8 times with respect to the original length, immersing at 80 degreeC for 80 second in the bridge | crosslinking liquid containing 4.3 mass parts boric acid and 3 mass parts potassium iodide. This stretched film was dried at 100 degreeC for 4 minutes, and the polarizer of thickness 20micrometer was obtained.

(6) saponification of polarizer protective film

The cellulose acylate film (T2) prepared above was immersed in an aqueous solution of sodium hydroxide at 55 ° C. at 1.5 mol / liter, and then sodium hydroxide was sufficiently washed out with water. Then, after immersing in 35 degreeC dilute sulfuric acid aqueous solution at 0.005 mol / liter for 1 minute, it immersed in water, and the dilute sulfuric acid aqueous solution was wash | cleaned sufficiently. Finally, the sample was sufficiently dried at 120 ° C.

(7) Fabrication of Polarizing Plate P1

The polarizer produced in said (5) and the cellulose acylate film (T2) saponified in said (6) were bonded together using polyvinyl alcohol-type adhesive agent continuously. Thus, the elongate polarizing plate P1 was produced. In addition, the absorption axis of a polarizer is coincident with the longitudinal direction of a polarizing plate, and when the width direction of a polarizer is 0 degrees (length direction is 90 degrees), the absorption axis of a polarizer was 90 degrees when it sees from the polarizer surface side.

(8) Preparation of Polarizing Plate P2

After bonding the surface of the polarizer side of the polarizing plate P1 mentioned above and the 1st optically anisotropic layer H of the retardation plate F1 mentioned above continuously using an adhesive, the cellulose which comprised the retardation plate F1 was comprised. The acylate film (T1) and the alignment film were peeled off, leaving only the first optically anisotropic layer (H).

Thus, the polarizing plate P2 which the polarizer protective film, the adhesive bond layer, the polarizer, the adhesive layer, and the 1st optically anisotropic layer H laminated | stacked in this order in the elongate shape was produced. The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (the length direction is 90 °), the absorption axis of the polarizer is 90 when viewed from the first optically anisotropic layer (H) side. °, the slow axis of the first optically anisotropic layer (H) was 15 degrees.

(9) Fabrication of Circular Polarizer Plate (CP1)

After bonding the surface of the 1st optically anisotropic layer H of the polarizing plate P2 mentioned above, and the surface of the 2nd optically anisotropic layer Q of the retardation plate F2 mentioned above continuously using an adhesive, a phase difference plate The cellulose acylate film (T1) and the alignment film which constituted (F2) were peeled off, and only the second optically anisotropic layer (Q) remained.

In this way, a circularly polarizing plate (CP1) in which a polarizer protective film, an adhesive layer, a polarizer, an adhesive layer, a first optically anisotropic layer (H), an adhesive layer, and a second optically anisotropic layer (Q) are laminated in this order in a long shape. ) The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (the length direction is 90 °), the absorption axis of the polarizer is 90 when viewed from the second optically anisotropic layer Q side. °, the slow axis of the 1st optically anisotropic layer H was 15 degrees, and the slow axis of the 2nd optically anisotropic layer Q was 75 degrees.

EXAMPLE 2

A polarizer and a polarizer protective film (cellulose acylate film (T2)) were prepared in the same manner as in Example 1 except that a polarizer produced by the following method was used instead of the polarizer in the polyvinyl alcohol adhesive. The long-shaped polarizing plate P3 bonded together was produced using, and circular polarizing plate CP2 was produced using this.

<Making Polarizers>

The polyvinyl alcohol (PVA) film of 20 micrometers in thickness was immersed in 25 degreeC pure water for 60 second, and after extending | stretching, it extended | stretched by 1.30 times. After immersing and dyeing the obtained film at 25 degreeC for 30 second in the dyeing liquid containing 0.3 mass part of iodine and 7.5 mass parts of potassium iodide with respect to 100 mass parts of water, with respect to 100 mass parts of water, It extended | stretched 8 times with respect to the original length, immersing at 80 degreeC for 80 second in the bridge | crosslinking liquid containing 4.3 mass parts boric acid and 3 mass parts potassium iodide. This stretched film was dried at 100 degreeC for 4 minutes, and the polarizer of thickness 8 micrometers was obtained.

EXAMPLE 3

A polarizer and a polarizer protective film (cellulose acylate film (T2)) were prepared in the same manner as in Example 1 except that a polarizer produced by the following method was used instead of the polarizer in the polyvinyl alcohol adhesive. The polarizing plate P4 of the elongate shape bonded together was produced continuously using, and the circularly polarizing plate CP3 was produced using this.

<Making Polarizers>

The polyvinyl alcohol (PVA) film of 20 micrometers in thickness was immersed in 25 degreeC pure water for 60 second, and after extending | stretching, it extended | stretched by 1.30 times. After immersing and dyeing the obtained film at 25 degreeC for 30 second in the dyeing liquid containing 0.3 mass part of iodine and 7.5 mass parts of potassium iodide with respect to 100 mass parts of water, with respect to 100 mass parts of water, It extended | stretched 12 times with respect to the original length, immersing at 80 degreeC for 80 second in the bridge | crosslinking liquid containing 4.3 mass parts boric acid and 3 mass parts potassium iodide. This stretched film was dried at 100 degreeC for 4 minutes, and the polarizer of thickness 5 micrometers was obtained.

EXAMPLE 4

 A polarizer and a polarizer protective film (cellulose acylate film (T2)) were prepared in the same manner as in Example 1 except that a polarizer produced by the following method was used instead of the polarizer in the polyvinyl alcohol adhesive. The polarizing plate P5 of the elongate shape bonded continuously using was produced, and circular polarizing plate CP4 was produced using this.

<Making Polarizers>

The polyvinyl alcohol (PVA) film of 60 micrometers in thickness was immersed in 25 degreeC pure water for 60 second, and it extended | stretched by 1.30 times after swelling process. After immersing and dyeing the obtained film in the dyeing solution containing 0.2 mass part of iodine and 5 mass parts of potassium iodide for 30 second with respect to 100 mass parts of water, for 100 mass parts of water, It was extended | stretched 6 times with respect to the original length, immersing at 80 degreeC for 80 second in the bridge | crosslinking liquid containing 4.3 mass parts boric acid and 3 mass parts potassium iodide. This stretched film was dried at 100 degreeC for 4 minutes, and the polarizer of thickness 30micrometer was obtained.

[Example 5]

Irgacure 127 (pKB: 13, molecular weight: 340, manufactured by BASF Corporation) was used instead of the photopolymerization initiator (irgacure 819) used in the preparation of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q). The polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, the first optically anisotropic layer (H), the pressure-sensitive adhesive layer, and the second optically anisotropic layer (Q) were formed in this order in the same manner as in Example 1 except for the above. A laminated circular polarizing plate (CP5) was produced.

EXAMPLE 6

(1) Preparation of Retardation Layer (F3)

(Formation of the first optically anisotropic layer (H))

Alkali saponification was performed to the cellulose acylate film (T1) by the same method as the retardation plate (F1), and the alignment film was formed.

Next, the rubbing process was performed continuously to the produced oriented film. At this time, the longitudinal direction and the conveyance direction of the elongate film were parallel, and the angle formed by the film longitudinal direction and the rotation axis of the rubbing roller was 75 ° (the film width direction was 0 °, the film length direction was 90 °, and the alignment film When viewed from the side and the clockwise direction is defined as a positive value with respect to the film width direction, the rotation axis of the rubbing roller is 165 °).

The optically anisotropic layer coating liquid (A) containing the discotic liquid crystal compound produced in Example 1 was apply | coated continuously to the wire bar of # 5.8 on the produced oriented film, and the retardation plate (F3) was produced. The conveyance speed (V) of the film was 26 m / min. For drying the solvent of the coating liquid and aging of the discotic liquid crystal compound, heating is performed for 90 seconds with warm air at 130 ° C. for 60 seconds followed by 60 seconds with warm air at 100 ° C., and UV irradiation is performed at 80 ° C. to align the liquid crystal compound. Immobilized. The thickness of the first optically anisotropic layer (H) was 2.3 µm, and Re at 550 nm was 290 nm. The average inclination angle with respect to the film surface of the disk surface of a DLC compound was 90 degrees, and it confirmed that the DLC compound was orientating perpendicularly with respect to the film surface.

Moreover, the angle of the slow axis of the 1st optically anisotropic layer H is parallel to the rotation axis of a rubbing roller, and when it sees the width direction of a film as 0 degree (90 degree of length directions), it looked at from the 1st optically anisotropic layer H side. The slow axis was 165 °.

Moreover, the cellulose acylate film (T1) and the alignment film (A) were in close contact with each other, and the first optically anisotropic layer (H) could be peeled from the alignment film.

(2) Preparation of Retardation Layer (F4)

(Formation of Second Optically Anisotropic Layer Q)

Alkali saponification was performed to the cellulose acylate film (T1) by the same method as the retardation plate (F1), and the alignment film was formed.

Next, the rubbing process was performed continuously to the produced oriented film. At this time, the longitudinal direction and the conveyance direction of the elongate film were parallel, and the angle formed by the film longitudinal direction and the rotation axis of the rubbing roller was 75 ° (the film width direction was 0 °, the film length direction was 90 °, and the alignment film When observed from the side and the clockwise direction is defined as a positive value with respect to the film width direction, the rotation axis of the rubbing roller is 15 °).

The optically anisotropic layer coating liquid (B) containing the discotic liquid crystal compound produced in Example 1 was apply | coated continuously to the wire bar of # 2.3 on the produced oriented film, and the retardation plate (F4) was produced. The conveyance speed (V) of the film was 26 m / min. For drying the solvent of the coating liquid and aging of the discotic liquid crystal compound, heating is performed for 90 seconds with warm air at 130 ° C. for 60 seconds followed by 60 seconds with warm air at 100 ° C., and UV irradiation is performed at 80 ° C. to align the liquid crystal compound. Immobilized. The thickness of the second optically anisotropic layer Q was 0.92 μm, and Re at 550 nm was 115 nm. The average inclination angle with respect to the film surface of the disk surface of a DLC compound was 90 degrees, and it confirmed that the DLC compound was orientating perpendicularly with respect to the film surface.

Moreover, the angle of the slow axis of the 2nd optically anisotropic layer Q is orthogonal to the rotational axis of a rubbing roller, and when the width direction of a film makes 0 degree (90 degree of length directions), it looked at from the 2nd optically anisotropic layer Q side. The slow axis was 105 degrees.

Moreover, the cellulose acylate film (T1) and the alignment film were in close contact with each other, and the second optically anisotropic layer (Q) could be peeled from the alignment film.

(3) Preparation of the polarizing plate P6

After bonding the surface of the polarizer side of the polarizing plate P1 produced in Example 1, and the 1st optically anisotropic layer H of the retardation plate F3 mentioned above continuously using an adhesive, the phase difference plate F3 is The cellulose acylate film (T1) and the orientation film which were comprised were peeled off, and only the 1st optically anisotropic layer (H) remained.

Thus, the polarizing plate P6 by which the polarizer protective film, the adhesive bond layer, the polarizer, the adhesive layer, and the 1st optically anisotropic layer (H) were laminated | stacked in this order in the elongate shape was produced. The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (the length direction is 90 °), the absorption axis of the polarizer is 90 when viewed from the first optically anisotropic layer (H) side. °, the slow axis of the first optically anisotropic layer (H) was 15 degrees.

(4) Fabrication of circular polarizer plate (CP6)

After bonding the surface of the 1st optically anisotropic layer H of the polarizing plate P6 mentioned above, and the surface of the 2nd optically anisotropic layer Q of the retardation plate F4 mentioned above continuously using an adhesive, a phase difference plate The cellulose acylate film (T1) and the alignment film which constituted (F4) were peeled off, and only the second optically anisotropic layer (Q) remained.

In this way, a circularly polarizing plate (CP6) in which a polarizer protective film, an adhesive layer, a polarizer, an adhesive layer, a first optically anisotropic layer (H), an adhesive layer, and a second optically anisotropic layer (Q) are laminated in this order in a long shape. ) The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (the length direction is 90 °), the absorption axis of the polarizer is 90 when viewed from the second optically anisotropic layer Q side. °, the slow axis of the 1st optically anisotropic layer H was 15 degrees, and the slow axis of the 2nd optically anisotropic layer Q was 75 degrees.

EXAMPLE 7

(1) Fabrication of phase difference plate F5

(Formation of Second Optically Anisotropic Layer Q)

Alkali saponification was performed to the cellulose acylate film (T1) by the same method as the retardation plate (F1), and the alignment film was formed.

Next, the rubbing process was performed continuously to the produced oriented film. At this time, the longitudinal direction and the conveyance direction of the elongate film were parallel, and the angle formed by the film longitudinal direction and the rotation axis of the rubbing roller was 75 ° (the film width direction was 0 °, the film length direction was 90 °, and the alignment film When observed from the side and the clockwise direction is defined as a positive value with respect to the film width direction, the rotation axis of the rubbing roller is 15 °).

The optically anisotropic layer coating liquid (C) containing the rod-shaped liquid crystal compound of the following composition was apply | coated continuously to the wire bar of # 2.2 on the produced oriented film, and the retardation plate (F5) was produced. The conveyance speed (V) of the film was 26 m / min. In order to dry the solvent of a coating liquid and the orientation aging of a rod-shaped liquid crystal compound, it heated for 60 second by 60 degreeC warm air, UV irradiation was performed at 60 degreeC, and the orientation of the liquid crystal compound was fixed. The thickness of the 2nd optically anisotropic layer Q was 0.8 micrometer, and Re in 550 nm was 120 nm. The average inclination angle with respect to the film surface of the long axis of a rod-shaped liquid crystal compound was 0 degrees, and it confirmed that the liquid crystal compound is orientating horizontally with respect to the film surface.

Moreover, the angle of the slow axis of the 2nd optically anisotropic layer Q is orthogonal to the rotational axis of a rubbing roller, and when the width direction of a film makes 0 degree (90 degree of length directions), it looked at from the 2nd optically anisotropic layer Q side. The slow axis was 105 degrees.

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Composition of Optically Anisotropic Layer Coating Liquid (C)

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80 parts by mass of rod-like liquid crystal compound-1

20 parts by mass of rod-like liquid crystal compound-2

Photopolymerization initiator Irgacure 819

  (pKB: 24, molecular weight: 419, manufactured by BASF Corporation) 3 parts by mass

1 part by mass of sensitizer (Kayacure-DETX, Nippon Kayaku Co., Ltd.)

0.3 parts by mass of fluorine-containing compound (FP-2)

193 parts by mass of methyl ethyl ketone

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Rod-shaped liquid crystal compound-1

[Formula 10]

Rod-shaped liquid crystal compound-2

[Formula 11]

(2) Fabrication of circular polarizer plate (CP7)

The surface of the 1st optically anisotropic layer H of the polarizing plate P2 produced in Example 1, and the surface of the 2nd optically anisotropic layer Q of the retardation plate F5 mentioned above were bonded together using an adhesive. Thereafter, the cellulose acylate film (T1) and the alignment film which constituted the retardation plate (F5) were peeled off, leaving only the second optically anisotropic layer (Q).

In this way, a circularly polarizing plate (CP7) in which a polarizer protective film, an adhesive layer, a polarizer, an adhesive layer, a first optically anisotropic layer (H), an adhesive layer and a second optically anisotropic layer (Q) are laminated in this order in a long shape. ) The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (the length direction is 90 °), the absorption axis of the polarizer is 90 when viewed from the second optically anisotropic layer Q side. °, the slow axis of the 1st optically anisotropic layer H was 15 degrees, and the slow axis of the 2nd optically anisotropic layer Q was 75 degrees.

EXAMPLE 8

(1) Fabrication of phase difference plate F6

(Formation of optically anisotropic layer)

Alkali saponification was performed to the cellulose acylate film (T1) by the same method as the retardation plate (F1), and the alignment film was formed.

Next, the rubbing process was performed continuously to the produced oriented film. At this time, the longitudinal direction and the conveyance direction of the elongate film were parallel, and the angle formed by the film longitudinal direction and the rotation axis of the rubbing roller was 45 ° (the film width direction was 0 °, the film length direction was 90 °, and the alignment film When observed from the side and the clockwise direction is defined as a positive value with respect to the film width direction, the rotation axis of the rubbing roller is 135 °).

The optically anisotropic layer coating liquid (C) containing the rod-shaped liquid crystal compound produced in Example 7 was continuously apply | coated # 2.2 wire bar on the produced oriented film, and the retardation plate (F6) was produced. The conveyance speed (V) of the film was 26 m / min. In order to dry the solvent of a coating liquid and the orientation aging of the rod-shaped liquid crystal compound, it heated for 60 second by 60 degreeC warm air, UV irradiation was performed at 60 degreeC, and the orientation of the liquid crystal compound was fixed. The thickness of the 2nd optically anisotropic layer Q was 0.8 micrometer, and Re in 550 nm was 120 nm. The average inclination angle with respect to the film surface of the long axis of a rod-shaped liquid crystal compound was 0 degrees, and it confirmed that the liquid crystal compound is orientating horizontally with respect to the film surface.

Moreover, the angle of the slow axis of an optically anisotropic layer was orthogonal to the rotation axis of a rubbing roller, and when the width direction of a film made 0 degree (90 degree of length directions), the slow axis was 45 degrees when it looked at from the optically anisotropic layer Q side. .

(2) Preparation of the polarizing plate (CP8)

After bonding together the surface of the polarizer of polarizing plate P1 produced in Example 1, and the surface of the optically anisotropic layer of retardation plate F6 mentioned above using an adhesive, the cellulose which comprised retardation plate F6 was comprised. The acylate film (T1) and the alignment film were peeled off, leaving only the optically anisotropic layer.

Thus, the circularly polarizing plate (CP8) which the polarizer protective film, the adhesive bond layer, the polarizer, the adhesive layer, and the optically anisotropic layer laminated | stacked in this order in the elongate shape was produced. The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (90 ° in the longitudinal direction), the absorption axis of the polarizer is 90 ° and the first optical anisotropy when viewed from the optically anisotropic layer side. The slow axis of the bed was 45 °.

EXAMPLE 9

(1) Preparation of polarizer

The polyvinyl alcohol (PVA) film of 20 micrometers in thickness was immersed in 25 degreeC pure water for 60 second, and after extending | stretching, it extended | stretched by 1.30 times. After immersing and dyeing the obtained film at 25 degreeC for 30 second in the dyeing liquid containing 0.3 mass part of iodine and 7.5 mass parts of potassium iodide with respect to 100 mass parts of water, with respect to 100 mass parts of water, It extended | stretched 20 times with respect to the original length, immersing at 80 degreeC for 80 second in the bridge | crosslinking liquid containing 4.3 mass parts boric acid and 3 mass parts potassium iodide. This stretched film was dried at 100 degreeC for 4 minutes, and the polarizer of thickness 1.8micrometer was obtained.

(2) Preparation of the polarizing plate P7

The polarizer produced above and the cellulose acylate film (T2) saponified in Example 1 were bonded together using the polyvinyl alcohol-type adhesive agent. In this way, polarizing plate P7 was produced. In addition, the absorption axis of a polarizer is coincident with the longitudinal direction of a polarizing plate, and when the width direction of a polarizer is 0 degrees (length direction is 90 degrees), the absorption axis of a polarizer was 90 degrees when it sees from the polarizer surface side.

(3) Preparation of the polarizing plate P8

After bonding the surface of the polarizer side of the polarizing plate P7 mentioned above with the 1st optically anisotropic layer H of the retardation plate F1 of Example 1 using an adhesive, the cellulose which comprised the retardation plate F1 The acylate film (T1) and the alignment film were peeled off, leaving only the first optically anisotropic layer (H).

Thus, the polarizing plate P8 in which the polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, and the first optically anisotropic layer (H) were laminated in this order was produced. The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (the length direction is 90 °), the absorption axis of the polarizer is 90 when viewed from the first optically anisotropic layer (H) side. °, the slow axis of the first optically anisotropic layer (H) was 15 degrees.

(4) Fabrication of Circular Polarizer Plate (CP9)

After bonding the surface of the 1st optically anisotropic layer H of the polarizing plate P8 mentioned above, and the surface of the 2nd optically anisotropic layer Q of the retardation plate F2 mentioned above using an adhesive, retardation plate F2 The cellulose acylate film (T1) and the alignment film which constituted) were peeled off, and only 2nd optically anisotropic layer (Q) remained.

Thus, the circularly polarizing plate CP9 in which the polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, the first optically anisotropic layer (H), the pressure-sensitive adhesive layer and the second optically anisotropic layer Q was laminated in this order was produced. did. The absorption axis of the polarizer coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizer is 0 ° (the length direction is 90 °), the absorption axis of the polarizer is 90 when viewed from the second optically anisotropic layer Q side. °, the slow axis of the 1st optically anisotropic layer H was 15 degrees, and the slow axis of the 2nd optically anisotropic layer Q was 75 degrees.

EXAMPLE 10

Regarding the photopolymerization initiator (Irgacure 819) used for the preparation of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q), 40 wt% of the mass was Irgacure 907 (pKB: 5.6, molecular weight: 279). , Manufactured by BASF Corporation) in the same manner as in Example 1, except that the polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, the first optically anisotropic layer (H), the pressure-sensitive adhesive layer, and the second optically anisotropic layer (Q) The circularly polarizing plate CP10 laminated | stacked in this order by the longest shape was produced.

[Comparative Example 1]

Irgacure 907 (pKB: 5.6, molecular weight: 279, manufactured by BASF Corporation) was used instead of the photopolymerization initiator (irgacure 819) used for the preparation of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q). The polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, the first optically anisotropic layer (H), the pressure-sensitive adhesive layer, and the second optically anisotropic layer (Q) were formed in this order in the same manner as in Example 7 except for the above. A laminated circular polarizing plate (CP11) was produced.

[Comparative Example 2]

Irgacure 369 (pKB: 5.3, molecular weight: 367, manufactured by BASF Corporation) was used instead of the photopolymerization initiator (irgacure 819) used in the preparation of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q). The polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, the first optically anisotropic layer (H), the pressure-sensitive adhesive layer, and the second optically anisotropic layer (Q) were formed in this order in the same manner as in Example 1 except for the above. A laminated circular polarizing plate (CP12) was produced.

[Comparative Example 3]

Irgacure 184 (pKB: 17, molecular weight: 204, manufactured by BASF Corporation) was used instead of the photopolymerization initiator (irgacure 819) used in the preparation of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q). The polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, the first optically anisotropic layer (H), the pressure-sensitive adhesive layer, and the second optically anisotropic layer (Q) were formed in this order in the same manner as in Example 1 except for the above. A laminated circular polarizing plate (CP13) was produced.

Further, the photopolymerization initiator was volatilized by the drying of the solvent of the coating liquid and the warm air drying for orientation aging of the discotic liquid crystal compound, and the curing was insufficient.

(Comparative Example 4)

Irgacure 907 (pKB: 5.6, molecular weight: 279, manufactured by BASF Corporation) was used instead of the photopolymerization initiator (irgacure 819) used for the preparation of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q). The polarizer protective film, the adhesive layer, the polarizer, the pressure-sensitive adhesive layer, the first optically anisotropic layer (H), the pressure-sensitive adhesive layer, and the second optically anisotropic layer (Q) were formed in this order in the same manner as in Example 3 except for the above. A laminated circular polarizing plate (CP14) was produced.

[Durability evaluation]

<Transmittance>

About each circularly polarizing plate produced by the Example and the comparative example, the single plate transmittance of the polarizing plate in wavelength 550nm was measured by the method shown below.

After measurement, each circularly polarizing plate was preserve | saved for 48 hours in the environment of 85 degreeC and 85% of a relative humidity, and the single plate transmittance was measured by the same method at wavelength 550nm.

The change amount (DELTA) CP (= single-sheet transmittance of each circular-polarizing plate before storage of each circularly-polarizing plate after preservation) of each circularly-polarizing plate before and after storage in the said environment was evaluated by the evaluation criteria shown below. The results are shown in Table 2 below.

(How to measure)

About each circularly polarizing plate, glass was stuck to the surface on the opposite side to a polarizer protective film.

The transmittance | permeability set the polarizer protective film side toward the light source, and measured using the automatic polarizing film measuring apparatus (VAP-7070, the Nippon Bunko Corporation make).

(Evaluation standard)

A: The change amount ΔCP of the transmittance is less than 3%

B: Amount of change ΔCP of transmittance is 3% or more and less than 5%

C: Change amount ΔCP of transmittance is 5% or more but less than 10%

D: Change amount ΔCP of transmittance is 10% or more

<Display article>

The display quality of each circularly polarizing plate was evaluated as follows.

The glass surface of the sample (glass with a circularly polarizing plate) used for the measurement of transmittance | permeability, and the reflecting plate (mat surface of aluminum foil) were bonded together using the adhesive, and visibility and display quality were evaluated under bright light.

Specifically, the reflected light when the fluorescent lamp was illuminated at the front and the polar angle of 45 degrees was observed, and the display quality at the polar angle of 45 degrees was evaluated based on the following criteria compared with the front.

Moreover, since this antireflection principle is the same principle as reflection of external light in the metal electrode of an organic electroluminescent display, it is similarly used suitably for an organic electroluminescent display.

(Evaluation standard)

A: Color change is not visually recognized at all (acceptable).

B: The color difference is visually recognized, but very slightly (acceptable).

C: Although the color difference is visually recognized, the reflected light is small and there is no problem in use (it is acceptable).

D: The color difference is visually recognized and the reflected light is also large and cannot be tolerated.

TABLE 2

As shown in Table 2, when the optically anisotropic layer was formed using a photopolymerization initiator having a base dissociation constant (pKb) of less than 8, it was found that the change in transmittance could not be suppressed and the display quality was also inferior (Comparative Example 1, 2 and 4).

Moreover, when an optically anisotropic layer was formed using the photoinitiator whose molecular weight is less than 240, since hardening became inadequate and haze rose, it turned out that it cannot evaluate (comparative example 3).

On the other hand, by using a photopolymerization initiator having a base dissociation constant (pKb) of 8 or more and a molecular weight of 240 or more, even when the display device is exposed in a high temperature, high humidity environment, the change in transmittance is suppressed and the display quality of the display device is reduced. It was found that it could be maintained (Examples 1 to 10).

In particular, from the comparison between Example 1 and Example 5, it was found that when the base dissociation constant (pKb) is 15 or more, the change in transmittance can be further suppressed and the display quality of the display device can be maintained higher.

Moreover, from the contrast between Example 1 and Example 6, the in-plane retardation of the λ / 4 plate satisfies the formula (I), and the in-plane retardation of the λ / 2 plate satisfies the formula (II). It has been found that the change of can be further suppressed and the display quality of the display device can be maintained higher.

In addition, from the contrast between Example 1 and Examples 7 and 8, not only the optically anisotropic layer using the discotic liquid crystalline compound but also the optically anisotropic layer using the rod-like liquid crystalline compound can suppress the change in transmittance and display the display device. It was found that the dignity can be kept high.

In addition, it was found from the contrast between Example 1 and Example 9 that when the thickness of the polarizer satisfies 2 to 30 μm, the change in transmittance can be further suppressed and the display quality of the display device can be maintained higher.

Moreover, from the result of Example 10, the photoinitiator contained in an optically anisotropic layer contains the photoinitiator X whose base dissociation constant pKb is 8 or more, and whose molecular weight is 240 or more, and content of the photoinitiator X is a thing of a photoinitiator. When it was 60 mass% or more with respect to total mass, it turned out that the change of transmittance | permeability can be suppressed and the display quality of a display apparatus can be maintained.

10, 20 polarizer
11 polarizer protective film
12 polarizer
13 pressure-sensitive adhesive layer
14 optically anisotropic layer
15 λ / 2 plates
16 λ / 4 plates
17 pressure sensitive adhesive layer
18 adhesive layer
30 organic EL display
32 organic EL panel

Claims (7)

As a polarizing plate which has a polarizer and an optically anisotropic layer arrange | positioned adjacent to the said polarizer in this order from a visual recognition side,
The polarizer is an iodine polarizer in which iodine is adsorbed and oriented on the polyvinyl alcohol-based film,
The optically anisotropic layer is a layer obtained by curing a composition containing a liquid crystalline compound having a polymerizable group and a photopolymerization initiator,
The said photoinitiator contains the photoinitiator X whose base dissociation constant pKb is 8 or more, and whose molecular weight is 240 or more, content of the said photoinitiator X is 60 mass% or more with respect to the total mass of the said photoinitiator,
The polarizer has a thickness of 2 to 30 μm,
The optically anisotropic layer contains a discotic liquid crystalline compound,
The optically anisotropic layer is a laminate having a λ / 2 plate and a λ / 4 plate,
From the visual recognition side, it has the said polarizer, the said (lambda) / 2 plate, and the said (lambda) / 4 plate in this order,
In-plane retardation of the λ / 4 plate satisfies the following formula (I),
The polarizing plate in which the in-plane retardation of the said (lambda) / 2 plate satisfy | fills following formula (II),
115 nm ≤ Re4 (550) ≤ 155 nm ... (I)
Re2 (550) = 2 × Re4 (550) ± 50nm (II)
Here, in Formula (I), Re4 (550) represents in-plane retardation at a wavelength of 550 nm of the λ / 4 plate, and in Formula (II), Re2 (550) represents the λ / 2 plate. In-plane retardation in wavelength 550nm is shown. delete delete delete The method according to claim 1,
Polarizing plate used for organic electroluminescent display. The display device which has a polarizing plate of Claim 1 or 5. The organic electroluminescent display device which has a polarizing plate of Claim 5.

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