KR20160014574A - Polarizing element and polarizing plate for display device having blue light emitting element - Google Patents

Abstract

[PROBLEMS] To a polarizing element or a polarizing plate capable of improving contrast and enhancing color display property in an organic electroluminescence display device.
[MEANS FOR SOLVING PROBLEMS] A base material having a polarizing function containing an azo compound is characterized in that the base material has a transmittance of 45% to 60% by itself, an average transmittance of 440 nm to 500 nm of 1 base material is 50% Is made orthogonal to the absorption axis direction so that the average transmittance of 550 to 650 nm is 10% or less.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing element or a polarizing plate for a display device having a blue light emitting element,

The present invention relates to a polarizing element or polarizer for organic electroluminescence.

Polarizing elements are generally produced by adsorbing and orienting iodine or a dichroic dye, which is a dichroic dye, on a polyvinyl alcohol resin film. A protective film containing triacetyl cellulose or the like is adhered to at least one surface of the polarizing element through an adhesive layer to form a polarizing plate and is used for a liquid crystal display device or the like. A polarizing plate using iodine as a dichroic dye is called an iodine polarizing plate and a polarizing plate using a dichroic dye as a dichroic dye is called a dye-based polarizing plate. Among these, the dye-based polarizing plate has high heat resistance, high durability and high stability, and is characterized by high color selectivity by blending. On the other hand, when compared with a polarizing plate having the same degree of polarization as the iodine- That is, there is a problem that the contrast is low. Therefore, it is desired to maintain high durability, to have various color selectivities, to have a higher transmittance, and to have high polarization characteristics.

In recent years, as shown in Patent Documents 1 and 2, a polarizing plate to which a 1/4? (1/4 wavelength to 550 nm) retardation plate having a retardation of 120 to 150 nm in phase difference is attached to a polarizing plate, (1/2 wavelength with respect to 550 nm) retardation plate having a retardation of 260 nm to 290 nm are adhered not only to a liquid crystal display but also to an organic EL display Device (hereinafter abbreviated as OLED), and the like. Although OLED displays by self-emission, an electrode or the like is provided in the display device thereof. When external light is incident on the device, reflected light is generated, and display contrast is lowered. In order to reduce the contrast deterioration due to the external light of the OLED, a 1/4? Phase difference plate is used as a circularly polarizing plate, and thus it is used in OLEDs for preventing reflection.

However, in general, the polarizing plate used in the OLED has white color when the absorption axes of two polarizing plates are arranged in parallel, and the polarizing plate used for the polarizing plate used for the liquid crystal display of 2 An iodine-based polarizing plate having a high degree of polarization exhibiting black was used when the absorption axes of the polarizing plates were arranged orthogonally. However, such an iodine-based polarizing plate has a problem that the transmittance thereof is 35% to 44%, so that the luminance is significantly lowered. In addition, since a large amount of light of 400 nm to 500 nm which is the short wavelength side of visible light is absorbed, the blue light emission effect of the OLED having strong luminescence near 460 nm is lowered as in the OLED described in Patent Document 3 and Patent Document 4, The luminance was lowered, and the displayability of color was deficient. In order to solve such a problem that the luminance is largely lowered as described above, it has been considered to use a iodine polarizer having a transmittance of 45% to 60% to prevent the luminance from lowering. However, since the iodine polarizer is inferior in durability, Resulting in a decrease in luminance due to use, and the reliability is remarkably lacking.

Patent Document 1: JP-A-2002-311239 Patent Document 2: JP-A 2007-27043 Patent Document 3: Japanese Patent No. 4970934 Patent Document 4: WO 2012/128081 Patent Document 5: Japanese Patent No. 4815149

Non-Patent Document 1: Application of Functional Dyes First Printing Edition CMC Publishing Co., Ltd. Masahiro Irie, P98 ~ 100 Non-Patent Document 2: Dye Chemical, Hosoda Yutaka Publications,

In view of such a problem, Patent Document 5 discloses a technique for improving the luminous efficiency by absorbing light of a wavelength band having a high light efficiency and increasing the transmittance of light of a wavelength band having a low light efficiency for OLED, Discloses a technique of an organic EL display capable of preventing a decrease in contrast ratio and contrast due to reflection. However, in this method, only a polarizing plate having the maximum absorption at 500 nm to 600 nm, which is a high visibility area, is disclosed, and improvement of contrast and display of color are insufficient only by adjustment of its transmittance. Further, with the polarizing plate adjusted only from 500 nm to 600 nm, the improvement of the contrast was insufficient. In Patent Document 5, there is no description on the specific transmittance, the degree of polarization, and the transmittance of each wavelength of the used polarizing plate.

When the light emission intensities of the respective wavelengths of the OLED described in Patent Document 3 and Patent Document 4 are checked, the light emission as shown in Fig. 1 is shown. The emission intensity of the OLED shown in Fig. 1 is measured using a spectroradiometer (Spectro Radiometer USR-40, manufactured by Ushio Electric Co., Ltd.), and the result is shown by converting the highest emission intensity to 100.

In the emission of OLED, light emission with a center at 460 nm is light emission by a blue light emitting material, and light emission with a center at 590 nm is light emission in which blue light emission is fluorescence-converted by a phosphor. This OLED method is called a color conversion method and is one of OLED methods. However, in this method, there is a problem that the color purity of blue is still poor, and further, when external light is incident on the OLED, the phosphor emits light and the contrast is lowered. The lowering of the contrast due to the external light is influenced by the stronger external light. In order to improve the color purity of the blue light emitting body and improve the light emitting efficiency, in order to suppress the emission of the phosphor by external light, It is necessary to control the transmittance of the light emitting layer. It has been necessary to design a polarizing element or a polarizing plate suitable for a display device having a blue self-luminous element.

In addition, when external light is incident on an OLED as in Patent Documents 3 and 4, it has been found that the light has a reflected light intensity as shown in Fig. The reflected light intensity of the OLED shown in Fig. 2 is a result obtained by measuring using the spectrophotometer U-4100 (manufactured by Hitachi, Ltd.), and converting the highest reflected light intensity to 100.

As shown in Fig. 2, it is found that the reflected light of the OLED by the external light exhibits strong reflection at 500 to 600 nm. The stronger the reflection of the external light, the larger the influence on the display device. Such reflected light is considered to be the influence of reflection of ITO (Indium Tin Oxide) transparent electrode used in OLED.

In this respect, it is required that OLEDs be capable of controlling the reflected light of 500 to 650 nm from external light without hindering the emission of 440 to 500 nm centered at 460 nm. In short, the polarizing element or its polarizing plate is required to have a single transmittance Has high transmittance and high durability, and has a high transmittance at 440 nm to 500 nm, and has a high degree of polarization at 500 nm to 650 nm, particularly a high degree of polarization at 550 nm to 650 nm.

Means for Solving the Problem As a result of intensive studies to solve the above problems, the present inventors have found that a polarizing element for a display device having a blue self-luminous element and including a substrate having a polarizing performance containing an azo compound, 45% to 60%, and the transmittance of each wavelength of 440 nm to 500 nm is 50% or more at a transmittance of each wavelength of one substrate and the two substrates are measured perpendicular to the absorption axis direction , And an average transmittance of 550 nm to 650 nm is 10% or less. The polarizing element or the polarizing plate of the present invention has been found to improve not only the contrast of the OLED but also the color reproducibility.

That is,

(1) A polarizing element comprising a base material having a polarizing function and containing an azo compound, wherein a transmittance of the base material is 45% to 60%, an average transmittance of 440 nm to 500 nm is 50% Wherein an average transmittance of 550 nm to 650 nm is 10% or less, which is obtained by measuring two polarizers perpendicularly to the absorption axis direction.

(2) An azo compound-containing base material having a polarizing function, wherein an average transmittance of 440 to 500 nm is 15% or more and a transmittance of 550 nm or less A polarizing element according to (1), wherein an average transmittance of at least 40%

(3) An azo compound-containing substrate having a polarizing property, wherein an average transmittance of 500 to 550 nm is 20% or less and a transmittance of 500 nm (1) or (2), wherein the average transmittance of the polarizing element is at least 45%

(4) The polarizing element according to any one of claims 1 to 3, wherein the polarization degree is at least 60%

(5) The polarizing element according to any one of claims 1 to 4, wherein at least one of the azo compounds contained in the substrate is in the form of a free acid and contains an azo compound represented by the formula (1)

Expression from, A ₁ represents a phenyl group or a naphthyl having a substituent, R ₁ denotes a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, sulfo, or sulfo, X ₁ is brought good substituents Phenylamino group.

(6) The polarizing element according to any one of (1) to (4), wherein at least one of the azo compounds contained in the substrate is in the form of a free acid and contains an azo compound represented by the formula (2).

In formula, A ₂ is a phenyl group having a substituent, R ₂ to R ₅ each independently, represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, or a sulfo group, X ₂ is a substituent Lt; RTI ID = 0.0 > phenylamino < / RTI > However, R ₂ to R ₅ do not satisfy that all of them are lower alkoxy groups at the same time.

(7) The polarizing element according to any one of (1) to (4), wherein at least one of the azo compounds contained in the substrate is in the form of free acid and contains an azo compound represented by the formula (3).

A ₃ represents a nitro group or an amino group, R ₆ and R ₇ each independently represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, X ₃ represents a substituent Lt; RTI ID = 0.0 > phenylamino < / RTI >

The average transmittance of 500 nm to 550 nm is 15% or less, the average transmittance of 440 nm to 500 nm of one substrate is 60% or more, and the average transmittance of 500 nm to 550 nm The polarizing element according to any one of (1) to (7), wherein the average transmittance of the polarizing element is 45% or more.

(9) An azo compound represented by the formula (4), wherein at least one of the azo compounds contained in the base material is in the form of a free acid, together with at least one of the azo compounds represented by the formulas (1) (1) to (8).

Wherein A ₄ represents a phenyl group having a substituent or a naphthyl group and R ₈ or R ₉ each independently represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, X ₄ represents an amino group which may have a substituent, a benzoylamino group which may have a substituent, a phenylamino group which may have a substituent, a phenylazo group which may have a substituent, or a naphthotriazole group which may have a substituent.

(10) The polarizing element according to (9), wherein X ₄ in the formula (4) is a phenylamino group which may have a substituent.

(11) The polarizing element according to (9) or (10), wherein A ₄ in the formula (4) is a phenyl group having a substituent.

(12) An azo compound represented by the formula (5), wherein at least one of the azo compounds contained in the base material is in the form of a free acid, together with any one of the azo compounds represented by the general formulas (1) (1) to (8).

In the formula, R ₁₀ and R ₁₁ each independently represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, a lower alkoxy group having a sulfo group, a carbonyl group or a phenyl group or a naphthyl group having a halogen atom.

(13) In the formula (5), R ₁₀ and R ₁₁ each independently represent a hydrogen atom, a lower alkyl group, a lower alkoxy group having a lower alkoxy group, a sulfo group or a sulfo group, a carbonyl group or a phenyl group having a halogen atom (12). ≪ / RTI >

(14) The polarizing element according to (13), wherein each of R ₁₀ and R ₁₁ is independently at least one substituent group, and the other substituent is a sulfo group or a carbonyl group.

(15) The polarizing element according to any one of (5) and (8) to (14), wherein R _{1 in the} formula (1) is a methyl group or a methoxy group.

(16) The polarizing element according to any one of (5) and (8) to (15), wherein A _{1 in the} formula (1) is a phenyl group having a substituent.

(17) The polarizing element according to any one of (6) to (14), wherein at least one of R ₄ and R _{5 in} the formula (2) is a methoxy group.

(18) The polarizing element according to any one of (6), (8) to (14) or (17), wherein at least one of R ₂ and R _{3 in} the formula (2) is a methoxy group.

19. The polarizing element according to characterized in that the phenyl group A ₂ is a substituent having the formula (2) (6), (8) to (15), (17) or (18).

(20) The polarizing element according to any one of (7) to (15), wherein at least one of R ₆ and R _{7 in} the formula (3) is a methoxy group.

(21) The polarizing element according to any one of (7) to (15) or (20), wherein R ₆ and R _{7 in} the formula (3) are methoxy groups.

(22) The polarizing element according to any one of (1) to (21), wherein the substrate comprises a polyvinyl alcohol-based resin film.

(23) The polarizer according to any one of (1) to (22), wherein a support film is provided on at least one surface of the polarizing element.

(24) The polarizing element described in any one of (1) to (22) or (22), wherein a retardation plate having a retardation of 120 nm to 150 nm is provided.

(25) The present invention relates to a polarizing element described in any one of (1) to (22), or an organic electroluminescence display device using the polarizing plate described in (23) or (24)

The present invention relates to a polarizing element or a polarizing plate capable of enhancing contrast and enhancing color display performance in a display device having a blue self-luminous device, particularly in an OLED.

1 shows the emission intensity of each wavelength of the OLED.
2 shows the intensity of the reflected light after the external light is incident on the OLED.
3 shows the transmittance of the polarizing plate of Example 2 on the first Y-axis, and the luminous intensity from the OLED display when the maximum intensity of Example 2 is converted to 100 on the second Y-axis.
Fig. 4 shows the light transmittance of the polarizing plate of Example 3 on the first Y-axis and the light intensity of the OLED display when the second Y-axis shows the highest intensity of Example 3 as 100. Fig.
5 shows the light transmittance of the polarizing plate of Example 6 on the first Y-axis and the light intensity from the OLED display when the maximum intensity of Example 6 is converted to 100 on the second Y-axis.
6 shows the light transmittance of the polarizing plate of Example 7 on the first Y-axis and the light intensity from the OLED display when the maximum intensity of Example 7 is converted to 100 on the second Y-axis.
7 shows the transmittance of the polarizing plate of Example 8 on the first Y-axis, and the luminous intensity from the OLED display device when the second Y-axis shows the highest intensity of Example 8 as 100. Fig.
8 shows the light emission intensity from the OLED display when the transmittance of the polarizing plate of Comparative Example 1 is converted to the first Y-axis and the highest intensity of Comparative Example 1 is converted to 100 to the second Y-axis.

Carrying out the invention  Best form for

The present invention relates to a polarizing element comprising a substrate having a polarizing function and containing a azo compound in a display device having a blue self-luminous device, in particular, an OLED, which has a simple transmittance of 45% to 60% The transmittance of each wavelength is 50% or more and the transmittance of each wavelength obtained by measuring the two substrates at right angles to the absorption axis direction has an average transmittance of 550 to 650 nm of 10 % Or less of a polarizing element or a polarizing plate.

The substrate is a film containing a hydrophilic polymer capable of containing an azo compound. The hydrophilic polymer is not particularly limited, and examples thereof include a polyvinyl alcohol-based resin, an amylose-based resin, a starch-based resin, a cellulose-based resin, and a polyacrylate-based resin. When an azo compound is contained, a resin including a polyvinyl alcohol-based resin and a derivative thereof is most preferable from the viewpoints of processability, dyeability, and crosslinkability. A polarizing element or a polarizing plate can be produced by incorporating the azo compound of the present invention and the combination thereof in the form of a film thereof and applying an orientation treatment such as drawing.

As the azo compound used in the present invention, a compound generally referred to as a dichroic dye can be used, but it is more preferable that the azo compound has high dichroism. In this case, the dichroic dye represented by an azo compound is not limited to azo compounds such as those shown in Non-Patent Document 1, children. direct. Yellow 12, Mr. children. direct. Yellow 28, Mr. children. direct. Yellow 44, Mr. children. direct. Orange 26, Mr. children. direct. Orange 39, Mr. children. direct. Orange 107, Mr. children. direct. Red 2, Mr. children. direct. Red 31, Mr. children. direct. Red 79, Mr. children. direct. Red 81, Mr. children. direct. Red 247, Mr. children. direct. Green 80, Mr. children. direct. Green 59, and organic dyes described in JP-A-2001-33627, JP-A-2002-296417, and JP-A-156759. These dichroic dyes include, in addition to the free acid, alkali metal salts (for example, Na salts, K salts, Li salts), ammonium salts, or salts of amines. However, the dichroic dye is not limited to these, and a known dichroic dye is exemplified.

The content of the dichroic dye including the azo compound in the substrate was adjusted so that the transmittance of the base material of the base material was 45% to 60%, the polarizing function was achieved, and the transmittance of each wavelength with respect to one substrate was 440 nm The average transmittance at 550 nm to 650 nm is adjusted to 10% or less in transmittance at each wavelength obtained by measuring two substrates at right angles to the absorption axis direction. Of the polarizing element or the polarizing plate can be obtained. Here, the average transmittance in the present invention is an average value of the transmittances obtained by measuring every 5 nm between the wavelength and the wavelength. Specifically, for example, an average value of 440 nm to 500 nm means an average value of transmittances of 440 nm, 445 nm, 450 nm, 460 nm, 465 nm, 470 nm, 475 nm, 480 nm, 485 nm, 490 nm, 495 nm and 500 nm. It is preferable that the transmittance of the base material group has a high transmittance because it affects the luminous efficiency when the light emitted from the OLED is transmitted. The transmittance at each wavelength obtained by measuring two substrates perpendicularly to the direction of the absorption axis is preferably as low as possible because it reduces the reflected light when external light is incident. However, in the case of an average transmittance of 440 nm to 500 nm, The transmittance of each wavelength obtained by increasing the transmittance of each wavelength to improve the efficiency of blue light emission and also the OLED display device has no factor of emitting light by external light. The transmittance in the base material group is preferably 45% to 55%. When the transmittance exceeds 60%, the polarization performance is remarkably lowered, which is not preferable. The degree of polarization at that time is preferably 60% or more, and preferably 70% or more, and more preferably 75% or more, although the decrease in contrast of the OLED is suppressed. As the control method of each wavelength, preferably, an average transmittance of 440 to 500 nm is 60% or more in transmittance of each wavelength in one substrate, and two substrates are measured perpendicular to the absorption axis direction The average transmittance at 550 nm to 650 nm in the transmittance at the wavelength is preferably 6% or less. Preferably, the transmittance at each wavelength obtained by measuring the transmittance of each wavelength of 440 nm to 500 nm is 65% or more and two substrates are perpendicular to the absorption axis direction, The average transmittance at 650 nm is preferably 3% or less.

In order to obtain a polarizing element suitable for an OLED, it is preferable that an average transmittance of 440 nm to 500 nm is 15% or more at a transmittance of each wavelength measured by making two of the substrates orthogonal to the absorption axis direction, It is preferable that the average transmittance of the wavelength of 550 to 650 nm is not less than 40% so that the emission of light of 440 to 500 nm is not inhibited and that the efficiency of light emission of the phosphor of 550 to 650 nm is not impaired. The average transmittance of each wavelength is in the range of 440 nm to 500 nm is 30% or more, and the transmittance of each wavelength of one substrate is in the range of 550 nm to 650 nm, More than 40% is good. Preferably, the average transmittance of each of the two substrates is in the range of 440 nm to 500 nm at a transmittance of each wavelength obtained by measuring the two substrates perpendicularly to the absorption axis direction of 40% or more, and the transmittance of each wavelength of one substrate , And an average transmittance of 550 nm to 650 nm is preferably 43% or more.

In order to prevent the contrast of the OLED from being affected by external light, it is preferable that the transmittance of each wavelength obtained by measuring two substrates, which are polarizing elements, perpendicular to the absorption axis direction is 20% And an average transmittance of 500 nm to 550 nm of one substrate is 45% or more. By controlling the polarization of 500 nm to 550 nm in this way, it is possible to suppress a decrease in contrast caused by external light.

The azo compound contained in the substrate is in the form of free acid and contains at least one azo compound represented by the formula (1), whereby a better polarizing element or polarizing plate of the present invention can be obtained. Preferably, R ₁ is a methyl group or a methoxy group, and more preferably, A ₁ is a phenyl group having a substituent.

The lower level of the lower alkyl group and the lower alkoxy group of the present invention means that the number of carbon atoms is 1 to 3. [

Expression from, A ₁ represents a phenyl group or a naphthyl having a substituent, R ₁ denotes a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, sulfo, or sulfo, X ₁ is brought good substituents Phenylamino group.

The azo compound contained in the substrate is in the form of free acid and contains at least one azo compound represented by the formula (2), whereby a better polarizing element or polarizing plate of the present invention can be obtained. Preferably, at least one of R ₄ and R _{5 in} the formula (2) is a methoxy group, more preferably at least one of R ₂ or R _{3 in} the formula (2) is a methoxy group, , It is preferable that A ₂ in the formula (2) is a phenyl group having a substituent.

In formula, A ₂ is a phenyl group having a substituent, R ₂ to R ₅ each independently, represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, or a sulfo group, X ₂ is a substituent Lt; RTI ID = 0.0 > phenylamino < / RTI > However, R ₂ to R ₅ do not satisfy that all of them are lower alkoxy groups at the same time.

The azo compound contained in the substrate is in the form of free acid and contains at least one azo compound represented by the formula (3), whereby a better polarizing element or polarizing plate of the present invention can be obtained. Preferably, it is recommended that at least one of R ₆ or R ₇ of formula (3) is a methoxy group, it is recommended more preferably, the R ₆ and R ₇ is a methoxy group of formula (3), and preferably , And A ₃ is a nitro group.

A ₃ represents a nitro group or an amino group, R ₆ and R ₇ each independently represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, X ₃ represents a substituent Lt; RTI ID = 0.0 > phenylamino < / RTI >

In order to improve the contrast of the OLED and improve the color reproducibility, it is preferable that the transmittance of each wavelength obtained by measuring two substrates having polarization perpendicular to the absorption axis direction is in the range of 500 nm to 550 nm and the average transmittance is 15% , And an average transmittance of 440 nm to 500 nm of one substrate is 60% or more, and an average transmittance of 500 nm to 550 nm is 45% or more.

In order to improve the contrast of the OLED and improve the color reproducibility, it is preferable that the transmittance of each wavelength obtained by measuring two substrates having polarization perpendicular to the absorption axis direction is in the range of 500 nm to 550 nm and the average transmittance is 15% (1) to (3) in order to obtain a good polarizing element having an average transmittance of 440 to 500 nm of not less than 60% and an average transmittance of 500 to 550 nm of not less than 45% With at least one of the azo compounds, at least one of the azo compounds contained in the substrate is in the form of free acid and at least one azo compound represented by the formula (4) is contained, whereby a better polarizing element can be obtained . Preferably, X ₄ in the formula (4) is a phenylamino group which may have a substituent, and more preferably, a further preferred polarizing element is obtained by the fact that A ₄ in the formula (4) is a phenyl group having a substituent have. Further, preferably, when R ₁ and R ₂ are hydrogen atoms, a better polarizing element can be obtained.

In the formulas, A ₄ represents a phenyl group or a naphthyl group having a substituent, and R ₉ or R ₉ each independently represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, X ₄ represents an amino group which may have a substituent, a benzoylamino group which may have a substituent, a phenylamino group which may have a substituent, a phenylazo group which may have a substituent, or a naphthotriazole group which may have a substituent.

In order to improve the contrast of the OLED and improve the color reproducibility, it is preferable that an average transmittance of 500 to 550 nm, which is obtained by measuring two substrates having polarized light orthogonal to the absorption axis direction, is 15% or less, In order to obtain a good polarizing element having an average transmittance of 440 to 500 nm of 60% or more and an average transmittance of 500 to 550 nm of 45% or more, any one of the azo compounds represented by formulas (1) to (3) At least one of the azo compounds contained in the azo compound is in the form of free acid and at least one azo compound represented by the formula (5) is contained, whereby a better polarizing element can be obtained. As the azo compound represented by the formula (5), preferably, R ₁₀ and R ₁₁ each independently represents a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, a carbonyl group or a halogen Is preferably a phenyl group having an atom in order to improve the contrast of the OLED and improve the color reproducibility. It is also preferable that R ₁₀ and R ₁₁ each independently represent a methoxy group, at least one substituent is a methoxy group, The substituent is preferably a sulfo group or a carbonyl group.

In the formula, R ₁₀ and R ₁₁ each independently represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, a lower alkoxy group having a sulfo group, a carbonyl group or a phenyl group or a naphthyl group having a halogen atom.

As a method for obtaining the dye represented by the formula (1), there may be mentioned, for example, the method described in Japanese Patent Publication No. 01-5623, but the method is not limited thereto.

Examples of the method for obtaining the dye represented by the formula (2) include the methods described in Japanese Patent No. 2622748, Japanese Patent No. 4825135, WO2007 / 148757, and WO2009 / 142192, but the present invention is not limited thereto.

As a method for obtaining the dye represented by the formula (3), for example, the method described in Japanese Patent Application No. 2011-197600 can be mentioned, but the method is not limited thereto.

Examples of the method for obtaining the azo compound represented by the formula (4) include the methods described in JP-A-2003-215338, JP-A-9-302250, JP-A-3881175, JP-A-4452237, , But are not limited thereto.

The azo compound represented by the formula (5) or its salt can be easily produced by coupling according to the production method of a conventional azo dye as described in Non-Patent Document 2. Specifically, when R ₁₀ and R ₁₁ are phenyl groups having a substituent, for example, R ₁₀ and R ₁₁ may be prepared by subjecting an amino compound represented by the formula (6) to a conventional method to obtain N, N-bis Hydroxy-3-sulfo-6-naphthyl) amine (generic name: di-acid) at 10 to 20 ° C to obtain a disazo compound. Subsequently, this solution is evaporated to dryness or salting-out, followed by drying, pulverization and pulverization to obtain the compound of formula (5).

Ra, Rb and Rc each independently represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, a lower alkoxy group having a sulfo group, a carbonyl group, or a halogen atom.

In the azo compounds A ₁ to A ₄ represented by the formulas (1) to (4), A ₃ represents a phenyl group or a naphthyl group having a substituent, and the substituent thereof includes a hydrogen atom, a lower alkyl group, a lower alkoxy group, A lower alkoxy group having a sulfo group or a sulfo group, or a carbonyl group. As a preferable substituent for further improving the efficiency and the high contrast of the OLED, a sulfo group, a methyl group, a methoxy group and a carbonyl group are preferable. The number of substituents may be one or two or more. When two or more substituents are present, the combination of substituents may have a plurality of the same substituents, but the combination thereof is not limited and may have a different substituent. For example, it is possible to select one substituent as a sulfo group and another substituent as a carbonyl group.

Next, the dye represented by the formula (1) is shown in the form of a free acid in more specific examples.

[Compound Example 1]

[Compound Example 2]

[Example 3]

[Compound Example 4]

[Example 5]

Next, a more specific example of the azo compound represented by the formula (2) is shown in the form of a free acid.

[Compound Example 6]

[Compound Example 7]

[Compound Example 8]

[Example 9]

[Example 10]

[Compound Example 11]

[Compound Example 12]

[Example 13]

[Compound Example 14]

 Next, the azo compound represented by the formula (3) is shown in the form of a free acid in a more specific example.

[Example 15]

[Compound Example 16]

[Example 17]

[Compound Example 18]

[Example 19]

[Example 20]

[Compound Example 21]

[Example 22]

[Example 23]

Specific examples of the dye represented by the chemical formula (4) include the azo compounds described in CI Direct Red 81, CI Direct Red 117, CI Direct Red 127, 3881175, 4033443, and the like.

Specific examples of the azo compound represented by the formula (4) are shown below in the form of free acid.

[Example 24]

[Example 25]

[Example 26]

[Example 27]

[Example 28]

[Example 29]

[Example 30]

[Example 31]

[Example 32]

[Example 33]

Specific examples of the azo compound represented by the formula (4) are shown below in the form of free acid.

[Example 34]

[Example 35]

[Example 36]

[Example 37]

[Example 38]

[Example 39]

[Example 40]

[Compound example 41]

[Compound Example 42]

Hereinafter, a specific method of producing a polarizing element will be described using a polyvinyl alcohol-based resin film as an example. The production method of the polyvinyl alcohol-based resin is not particularly limited and can be produced by a known method. As a production method, for example, a polyvinyl acetate resin can be obtained by saponification. As the polyvinyl acetate-based resin, polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as copolymers of vinyl acetate and other monomers copolymerizable therewith are exemplified. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids. The saponification degree of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 95 mol% or more. The polyvinyl alcohol-based resin may also be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol-based resin means a viscosity-average degree of polymerization, and can be determined by a well-known technique in the art. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, and preferably about 1,500 to 6,000.

Such a polyvinyl alcohol-based resin film is used as the original film. The method of forming the polyvinyl alcohol-based resin is not particularly limited, and a film can be formed by a known method. In this case, the polyvinyl alcohol-based resin film may contain glycerin, ethylene glycol, propylene glycol, low molecular weight polyethylene glycol or the like as a plasticizer. The amount of the plasticizer is 5 to 20% by weight, preferably 8 to 15% by weight. The thickness of the original film containing the polyvinyl alcohol-based resin is not particularly limited, but is preferably about 5 탆 to 150 탆, and preferably about 10 탆 to 100 탆.

The original film thus obtained is then subjected to a swelling step. The swelling treatment is applied by immersing in a solution at 20 to 50 ° C for 30 seconds to 10 minutes. The solution is preferably water. It is preferable to adjust the draw ratio to 1.00 to 1.50 times, preferably 1.10 to 1.35 times. In the case of shortening the time for producing the polarizing element film, the swelling process may be omitted since the film is swollen even in the dyeing process of the dye.

The swelling process is performed by immersing the polyvinyl alcohol resin film in a solution at 20 to 50 캜 for 30 seconds to 10 minutes. The solution is preferably water. In the case where the time for producing the polarizing element is shortened, the swelling step can be omitted since it swells even during the dyeing treatment of the dye.

After the swelling process, a dyeing process is carried out. In the dyeing step, it is possible to impregnate with an azo compound (commonly called a dichroic dye) shown in Non-Patent Document 1 and the like. This azo compound is impregnated with a dyeing step in that it is a step of coloring the color. As the azo compound, azo compounds represented by the following formula (1), (2), (3), (4) and (5) The pigment can be adsorbed and impregnated into the polyvinyl alcohol film. The dyeing step is not particularly limited as long as the dye is adsorbed and impregnated on the polyvinyl alcohol film. For example, the dyeing step is carried out by immersing the polyvinyl alcohol resin film in a solution containing an azo compound. The solution temperature in this step is preferably 5 to 60 占 폚, more preferably 20 to 50 占 폚, and particularly preferably 35 to 50 占 폚. The time for immersion in the solution can be appropriately adjusted, but it is preferably adjusted from 30 seconds to 20 minutes, more preferably from 1 to 10 minutes. The dyeing method is preferably carried out by immersing in the above solution, but may also be carried out by applying the solution to a polyvinyl alcohol resin film. The solution containing the azo compound may contain sodium bicarbonate, sodium chloride, sodium sulfate, anhydrous sodium sulfate, sodium tripolyphosphate and the like as the dyeing auxiliary. The content thereof can be adjusted to an arbitrary concentration depending on the time and temperature depending on the dyeability of the dye. The content of each of them is preferably 0 to 5% by weight, and more preferably 0.1 to 2% by weight. Azo compounds, which are dichroic dyes described in Non-Patent Document 1, and azo compounds represented by Chemical Formula (1), Chemical Formula (2), Chemical Formula (3), Chemical Formula (4), Chemical Formula (5) In addition, the salt of the compound may be used. Such a salt can be used as an alkali metal salt such as a lithium salt, a sodium salt, and a potassium salt, or an organic salt such as an ammonium salt or an alkylamine salt. Preferably, it is a sodium salt.

After the dyeing step, a cleaning step (hereinafter referred to as a cleaning step 1) can be performed before the next step. The cleaning step 1 is a step of cleaning the dye solvent attached to the surface of the polyvinyl alcohol resin film in the dyeing step. By performing the cleaning step 1, migration of the dye into the next liquid to be treated can be suppressed. In the cleaning step 1, water is generally used. The cleaning method is preferable to be immersed in the above solution, but it can be cleaned by applying the solution to the polyvinyl alcohol resin film. The cleaning time is not particularly limited, but is preferably 1 to 300 seconds, and more preferably 1 to 60 seconds. The temperature of the solvent in the cleaning step 1 needs to be a temperature at which the hydrophilic polymer is not dissolved. In general, it is cleaned at 5 to 40 ° C. However, even if the step of the cleaning step 1 is not carried out, there is no problem in performance, so that the present step may be omitted.

After the dyeing step or the washing step 1, a step of containing a crosslinking agent and / or a water-proofing agent can be carried out. Examples of the crosslinking agent include boron compounds such as boric acid, borax or ammonium borate, polyvalent aldehydes such as glyoxal or glutaraldehyde, polyvalent isocyanate compounds such as biuret type, isocyanurate type or block type, And the like can be used. In addition, ethylene glycol glycidyl ether, polyamide epichlorohydrin and the like can be used. Examples of the water-proofing agent include peroxydisuccinic acid, ammonium persulfate, calcium perchlorate, benzoin ethyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, ammonium chloride, magnesium chloride and the like. Is used. A step of containing a crosslinking agent and / or a water-proofing agent is carried out by using at least one crosslinking agent and / or a water-repellent agent as shown above. As the solvent at this time, water is preferable but not limited. The concentration of the crosslinking agent and / or the water-proofing agent in the solvent in the step of containing the crosslinking agent and / or the water-proofing agent is preferably 0.1 to 6.0% by weight, more preferably 1.0 to 4.0% by weight desirable. The solvent temperature in this step is preferably 5 to 70 캜, more preferably 5 to 50 캜. The method of containing the crosslinking agent and / or the water-proofing agent in the polyvinyl alcohol resin film is preferably carried out in the above solution, but the solution may be applied or coated on the polyvinyl alcohol resin film. The treatment time in this step is preferably 30 seconds to 6 minutes, more preferably 1 to 5 minutes. However, it is not essential to contain a cross-linking agent and / or a water-proofing agent, and in the case where it is desired to shorten the time, the cross-linking treatment or the water-resistant treatment is not required, this treatment step may be omitted.

After the dyeing step, the washing step 1, or the step of containing a crosslinking agent and / or a water-proofing agent is carried out, a drawing step is carried out. The stretching step is a step of uniaxially stretching the polyvinyl alcohol film. The stretching method may be either a wet stretching method or a dry stretching method, and the present invention can be achieved because the stretching magnification is 3 times or more. The stretching ratio is preferably 3 times or more, and preferably 5 to 7 times.

In the case of the dry stretching method, when the stretching heating medium is an air medium, the temperature of the air medium is preferably stretched at a room temperature to 180 ° C. The humidity is preferably treated in an atmosphere of 20 to 95% RH. As the heating method, for example, a rolling-in-zone stretching method, a roll-to-roll hot rolling method, a rolling-rolling method, an infrared heating stretching method and the like can be mentioned. Although the stretching process can be performed in one stage, it can also be performed in two or more stages in multi-stage stretching.

In the case of the wet stretching method, stretching is performed in water, a water-soluble organic solvent, or a mixed solution thereof. It is preferable to carry out the stretching treatment while immersing it in a solution containing a crosslinking agent and / or a water-proofing agent. Examples of the crosslinking agent include boron compounds such as boric acid, borax or ammonium borate, polyvalent aldehydes such as glyoxal or glutaraldehyde, polyvalent isocyanate compounds such as biuret type, isocyanurate type or block type, And the like can be used. In addition, ethylene glycol glycidyl ether, polyamide epichlorohydrin, and the like can be used. Examples of the water-proofing agent include peroxy succinic acid, ammonium persulfate, calcium perchlorate, benzoin ethyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, ammonium chloride, magnesium chloride and the like. The stretching is carried out in a solution containing at least one crosslinking agent and / or a water-repellent agent as shown above. The crosslinking agent is preferably boric acid. The concentration of the crosslinking agent and / or the water-proofing agent in the stretching step is preferably 0.5 to 15% by weight, and more preferably 2.0 to 8.0% by weight, for example. The draw ratio is preferably 2 to 8 times, more preferably 5 to 7 times. The stretching temperature is preferably 40 to 60 占 폚, more preferably 45 to 58 占 폚. The stretching time is usually 30 seconds to 20 minutes, more preferably 2 to 5 minutes. The wet stretching process can be performed in one stage, but it can also be performed in two or more stages in multi-stage stretching.

After the stretching process, there may be a step of depositing a crosslinking agent and / or a water-repellent agent on the surface of the film or adhering foreign matter, so that a cleaning step (hereinafter referred to as a cleaning step 2) for cleaning the film surface can be performed. The cleaning time is preferably 1 second to 5 minutes. The cleaning method is preferably immersed in the cleaning solution, but the solution can be cleaned by applying or coating the polyvinyl alcohol resin film. It may be subjected to a washing treatment in one stage or a multi-stage treatment in two or more stages. The solution temperature in the washing step is not particularly limited, but is usually 5 to 50 占 폚, preferably 10 to 40 占 폚.

Examples of the solvent to be used in the above-mentioned treatment step include water, dimethylsulfoxide, N-methylpyrrolidone, methanol, ethanol, propanol, isopropyl alcohol, glycerin, ethylene glycol, propylene glycol, diethylene glycol, But are not limited to, alcohols such as ethylene glycol, triethylene glycol, tetraethylene glycol or trimethylolpropane, and amines such as ethylenediamine or diethylenetriamine. Mixtures of one or more of these solvents may also be used. The most preferred solvent is water.

After the stretching process or the cleaning process 2, the drying process of the film is performed. The drying treatment can be carried out by natural drying. However, in order to further improve the drying efficiency, moisture can be removed from the surface and / or air blow drying can be performed by roll compression, air knife, or absorbing roll. The drying treatment temperature is preferably a drying treatment at 20 to 100 占 폚, more preferably a drying treatment at 60 to 100 占 폚. The drying treatment time is 30 seconds to 20 minutes, preferably 5 to 10 minutes.

In the above method, the base material having a polarizing function containing the azo compound of the present invention is used. The base material has a transmittance of 45% to 60% by itself, an average transmittance of 440 nm to 500 nm of one base material is 50% And the average transmittance of 550 nm to 650 nm obtained by measuring the two polarizing plates orthogonal to the absorption axis direction is 10% or less.

The obtained polarizing element is a polarizing plate by providing a transparent protective layer on one side or both sides thereof. The transparent protective layer can be provided as a coating layer of a polymer or as a laminate layer of a film. As the transparent polymer or film forming the transparent protective layer, a transparent polymer or film having high mechanical strength and good thermal stability is preferable. As the material to be used as the transparent protective layer, for example, a cellulose acetate resin or a film thereof such as triacetylcellulose or diacetylcellulose, an acrylic resin or a film thereof, a polyvinyl chloride resin or a film thereof, a nylon resin or a film thereof, An ester resin or a film thereof, a polyallylate resin or a film thereof, a cyclic olefin resin or a film thereof using a cyclic olefin such as norbornene as a monomer, a polyethylene, a polypropylene, a polyolefin having a cyclo- or norbornene skeleton, A resin, a polymer or a film thereof in which the main chain or side chain is imide and / or amide. As the transparent protective layer, a resin having liquid crystallinity or a film thereof may be provided. The thickness of the protective film is, for example, about 0.5 탆 to 200 탆. A polarizing plate is produced by providing one or more layers of the same type or different kinds of resins or films on one side or both sides thereof.

In order to adhere the transparent protective layer to the polarizing element, an adhesive is required. The adhesive is not particularly limited, but a polyvinyl alcohol adhesive is preferable. Examples of the polyvinyl alcohol adhesive include, but are not limited to, Goseonol NH-26 (manufactured by Nihon Kogyo Co., Ltd.) and Xceval RS-2117 (manufactured by Kuraray Co., Ltd.). To the adhesive, a cross-linking agent and / or a water-proofing agent may be added. As the polyvinyl alcohol adhesive, a maleic anhydride-isobutylene copolymer is used, but if necessary, an adhesive obtained by mixing a crosslinking agent can be used. As the maleic anhydride-isobutylene copolymer, there may be mentioned, for example, isobarane # 18 (manufactured by Kuraray Co.), isoban # 04 (manufactured by Kuraray Co., Ltd.), ammonia modified isobarane # 104 # 110 (manufactured by Kuraray Co., Ltd.), imidized isoban # 304 (manufactured by Kuraray Co., Ltd.) and imidized isoban # 310 (manufactured by Kuraray Co., Ltd.). A water-soluble polyfunctional epoxy compound may be used as the crosslinking agent. Examples of the water-soluble polyvalent epoxy compound include Denacol EX-521 (manufactured by Nagase Chemtech Co., Ltd.) and tetra-C (manufactured by Mitsui Gas Chemical Co., Ltd.). As the adhesive other than the polyvinyl alcohol resin, a known adhesive such as urethane-based, acrylic-based, or epoxy-based adhesive can be used. In addition, additives such as zinc compounds, chlorides, iodides and the like may be contained at a concentration of about 0.1 to 10% by weight at the same time for the purpose of improving the adhesion of the adhesive or improving the water resistance. The additives are not limited either. The transparent protective layer is adhered with an adhesive, and then dried or heat-treated at a suitable temperature to obtain a polarizing plate.

When the polarizing plate is adhered to a display device such as organic electroluminescence in some cases, various kinds of functional layers for improving the viewing angle and / or improving the contrast on the surface of the protective layer or film, A layer or a film having brightness enhancement may be provided. An adhesive is preferably used to adhere the polarizing plate to these films or display devices.

The polarizing plate may have various known functional layers such as an antireflection layer, an antiglare layer, and a hard coat layer on the other surface, that is, the exposed surface of the protective layer or the film. A coating method is preferable for producing the layer having various functions, but a film having the function can be bonded through an adhesive or a pressure-sensitive adhesive. The various functional layers may be layers or films for controlling the retardation. The OLED display device can have an antireflection function when external light is incident on the OLED by adhering a retardation plate of 120 to 150 nm, in particular, a 1/4? Retardation plate to about 555 nm.

In the above-mentioned method, the base material having a polarizing function containing the azo compound of the present invention, the transmittance of the base material of the base material is 45% to 60%, the average transmittance of 440 nm to 500 nm of one base material is 50% Wherein the average transmittance of 550 nm to 650 nm is 10% or less, which is obtained by measuring two substrates at right angles to the absorption axis direction. A display device having a color-light-emitting device using a polarizing element or a polarizing plate of the present invention, particularly an OLED, has high reliability, high contrast for a long period of time, and high color reproducibility.

The thus obtained polarizing element or polarizing plate of the present invention is used as an effective polarizing element or polarizing plate in a display device that emits blue light, for example, organic electroluminescence or the like, by providing a protective layer, a functional layer, .

Example

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto. The transmittance shown in the examples was evaluated as follows.

The transmittance when the polarizing element or the polarizing plate is measured in a single sheet as the transmittance Ts and the two polarizing elements or the polarizing plate are superimposed so that their absorption axis directions are the same is taken as the flat actuation transmittance Tp, Of the polarizing plate was superimposed on the polarizing plate so that its absorption axes were perpendicular to each other.

The simplex transmittance Ys is calculated by the following formula (I) by obtaining the spectral transmittance τλ for each wavelength interval dλ (here, 5 nm) in the wavelength region of 400 nm to 700 nm. In the formula, P? Represents the spectral distribution of the standard light (C light source), and y? Represents the 2-degree visual field color function.

In formula (I)

The spectral transmittance τλ was measured using a spectrophotometer ("U-4100" manufactured by Hitachi, Ltd.).

The polarization degree ρy was determined from the equation (II) from the equilibrium transmittance Tp and the orthogonality transmittance Tc.

The formula (II)

Example  One

A polyvinyl alcohol film (VF-XS manufactured by Kuraray Co., Ltd.) having an average degree of polymerization of 99% or more of 99% or more was immersed in hot water at 45 ° C for 2 minutes, and a swelling treatment was applied to obtain a stretching magnification of 1.30. The swollen film was dyed by immersing it in an aqueous solution at 45 占 폚 containing 1500 parts by weight of water, 1.5 parts by weight of sodium tripolyphosphate and 0.15 part by weight of the dye described in Example 2 of JP-A No. 09-132726. The film obtained by the dyeing was stretched 5.0 times while stretching the film for 5 minutes in an aqueous solution containing boric acid of 30.0 g / L at 50 占 폚. While the film obtained by the boric acid treatment was kept in a tense state, the film was washed with water at 30 캜 for 20 seconds, and the obtained film was dried at 70 캜 for 9 minutes to obtain a polarizing element having a transmittance of about 50% . The polarizing element obtained by drying and a triacetyl cellulose film (TD-80U manufactured by Fuji Photo Film Co., Ltd.) treated with alkali were laminated using a polyvinyl alcohol-based adhesive to obtain a polarizing plate. The resulting polarizer was subjected to a durability test for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Example  2

A polarizing element and a polarizing plate were manufactured and measured in the same manner except that 0.15 part by weight of the dye described in Example 2 of JP-A No. 09-132726 described in Example 1 was replaced by 0.15 part by weight of the dye described in Example 3 of JP-A-10-259311 As a sample. The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Example  3

Except that 0.15 part by weight of the dye described in Example 2 of JP-A No. 09-132726 described in Example 1 was replaced with 0.1 part by weight of the dye described in Example 2 of JP-A-2-309302 having the structure of formula (2) A polarizing element and a polarizing plate were prepared and used as a measurement sample. The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Example  4

0.15 parts by weight of the dye described in Example 2 of JP-A No. 09-132726 described in Example 1 was replaced with 0.2 parts by weight of the azo compound described in Example 1 having the structure of formula (1) And a polarizing plate were prepared and used as measurement samples. The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Example  5

0.15 parts by weight of the dye described in Example 2 of JP-A No. 09-132726 described in Example 1 was replaced with 0.2 part by weight of the azo compound described in International Publication No. WO2013 / 035752 A1 Compound Example 1 having the structure of Formula (3) A polarizing element and a polarizing plate were produced and used as a measurement sample. The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Example 6

0.15 parts by weight of the dye described in Example 2 of JP-A No. 09-132726 described in Example 1 was replaced with 0.098 parts by weight of the azo compound described in Example 1 of Japanese Patent No. 2622748 having the structure of Formula (2) A polarizing plate was prepared and used as a measurement sample. The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Example  7

The dyeing liquid containing 0.15 part by weight of the dye described in Example 2 of JP-A No. 09-132726 described in Example 1 was mixed with 0.098 part by weight of the azo compound described in Example 1 of Japanese Patent No. 2622748 having the structure of Formula (2) 5) 2012-041024 A polarizing element and a polarizing plate were prepared in the same manner as in Example A-3 except that the dyeing solution was replaced with a dyeing solution containing 0.7 parts by weight of the dye of the formula (16) described in Example A-3. The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Example  8

The dyeing solution containing 0.15 part by weight of the dye described in Example 2 of JP-A No. 09-132726 described in Example 1 was mixed with 0.098 part by weight of the azo compound described in Example 1 of Japanese Patent No. 2622748 having the structure of Formula (2) Polarizing plate and a polarizing plate were prepared in the same manner as in Example 1 except for replacing the dyeing solution in which 0.7 part by weight of the dye of Compound No. 1 with 4033443 having the structure of Formula (4) was used. The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH, and the transmittance and the degree of polarization were not changed.

Comparative Example  One

A measurement sample was prepared in the same manner as in Example 1, except that an iodine-based polarizing plate containing no dichroic dye was prepared according to the prescription of Comparative Example No. 2008-065222 and a polarizing plate having a transmittance of about 50% was produced . The durability test of the obtained polarizing plate was conducted for 700 hours under the environment of a temperature of 85 캜 and a relative humidity of 85% RH. The single light transmittance was changed to 88%, and the degree of polarization was lost.

Table 1 shows the transmittance (Ys), the degree of polarization (ρy), and the transmittance (ρy) of the base material in Examples 1 to 8 and Comparative Example 1 at 4 nm to 500 nm (hereinafter abbreviated as Ave440-500 (Hereinafter referred to as " Ave500 ") obtained by measuring the average transmittance (Ts) in a single body in a wavelength range of 500 nm to 550 nm (Hereinafter, abbreviated as " -550 ") and an average transmittance (Tc) of each wavelength obtained by measuring two substrates perpendicularly to the absorption axis direction. The average transmittance (Tc) of each wavelength obtained by measuring the average transmittance (Ts) in a single body at 650 nm (hereinafter abbreviated as Ave550-650) and two substrates perpendicular to the absorption axis direction.

From the results shown in Table 1, it is understood that a substrate having a polarization function containing the azo compound of the present invention having a high Ts of from 440 nm to 500 nm and a large difference between Ts and Tc of from 550 nm to 650 nm, To 60% of the average transmittance of 550 nm to 650 nm of two substrates obtained by measuring the average transmittance of 440 nm to 500 nm of the substrate to 50% or more and perpendicularly to the absorption axis direction is 10% or less Can be seen.

Next, a 1/4? Phase difference plate having a retardation of 138 nm obtained by stretching polycarbonate was adhered to the polarizing plate obtained in Examples 1 to 8 and Comparative Example 1 at an angle of 45 占 with respect to the stretching axis thereof and the absorption axis of the polarizing plate , And the resultant polarizing plate was adhered to an OLED display through a pressure-sensitive adhesive (PTR-3000, manufactured by Nippon Kayaku Co., Ltd.) to obtain a measurement sample. The xy color coordinates were measured using a color luminance meter (CS-200, manufactured by Konica Minolta) based on the xy chromaticity diagram determined in CIE 1931 when the red, green, and blue colors of the OLED were measured and the color purity was measured . The color reproduction range at that time is represented by the ratio (%) thereof by calculating the NTSC ratio (the color space ratio of the television standardized by the National Television System Committee). Table 2 shows the results of the xy color coordinates and the NTSC ratio when measuring the color purity thereof.

The NTSC ratio is a coordinate when the NTSC ratio is 100%. The color coordinates of red are (0.67, 0.33), the color coordinates of green are (0.21, 0.71), the color coordinates of blue are (0.14, 0.08) And the area derived from its coordinates was calculated as 100%. The calculation method was calculated according to the following formula (III): < EMI ID =

The formula (III)

NTSC ratio = (Rx Gy + Gx By + Bx Ry - Ry x Gx - Gy x Bx - By x Rx)

(Rx for red measurement, Ry for red measurement, Gx for green measurement, Gy for green measurement, Gy for green measurement, Bx for blue measurement, Bx for blue measurement, and the y coordinate is By, respectively)

From the results in Table 2, it can be seen that the NTSC ratio is improved by providing the OLED with the polarizing plate obtained by the present invention, as compared with the case of using the conventional iodine polarizing plate.

Next, the embodiment uses an example where the polarizer used in 6 with respect to the adhesive OLED through the 1 / 4λ, the condition of the external light luminance 500 cd / m ^2, color luminance meter (CS-200, Konica Minolta Co., Ltd.) the OLED luminance , And the contrast between the white projection and the black projection was calculated. The results are shown in Table 3. In addition, OLED-ON indicates a state when white light is emitted, and OLED-OFF indicates a state when displaying a black state.

Under the following Example 6 of the 1 / 4λ in respect of the adhesive OLED via the external light luminance 1500 cd / m ² polarizer conditions used in, the OLED luminance using a color luminance meter (CS-200, Konica Minolta Co., Ltd.) And the contrast between the white projection and the black projection was calculated. The results are shown in Table 4.

Next, the OLED luminance was measured using a color luminance meter (CS-200, manufactured by Konica Minolta Co., Ltd.) under the condition of an external light luminance of 500 cd / m ² with respect to the OLED in which the polarizer used in Example 8 was bonded via 1/4? , And the contrast between the white projection and the black projection was calculated. The results are shown in Table 5.

Next, OLED luminance was measured using a color luminance meter (CS-200, manufactured by Konica Minolta Co., Ltd.) under the condition of an external light luminance of 1500 cd / m ² with respect to the OLED to which the polarizer used in Example 8 was bonded via 1/4? , And the contrast between the white projection and the black projection was calculated. The results are shown in Table 6.

Then, using the Comparative Examples a polarizing plate used in the first with respect to the adhesive OLED through the 1 / 4λ, under the conditions of external light luminance 500 cd / m ^2, color luminance meter CS-200 (Konica Minolta Co., Ltd.) by measuring the OLED luminance , And the contrast between the white projection and the black projection was calculated. The results are shown in Table 7.

Then, using the Comparative Examples a polarizing plate used in the first with respect to the adhesive OLED through the 1 / 4λ, under the conditions of external light luminance 1500 cd / m ^2, color luminance meter CS-200 (Konica Minolta Co., Ltd.) by measuring the OLED luminance , And the contrast between the white projection and the black projection was calculated. The results are shown in Table 8.

As can be seen from the results of Tables 3 to 8, in the case of using the polarizing plates of Examples 1 to 8, the contrast at the time of incidence of external light was improved by about 10 times and the effect was also improved in contrast. It can be seen that the brightness at the time of white light emission in the case of white projection of the OLED is reduced and the improvement in contrast at the time of incidence of external light such as 500 cd / m ² or 500 cd / m ² is hardly observed .

3 shows the light emission intensity from the OLED display device when the transmittance of the polarizing plate of Example 2 is converted into the first Y-axis and the maximum intensity of 100 is converted into the second Y-axis. From the graph of FIG. 3, it can be seen from the graph of FIG. 3 that the base material having a polarizing function containing the azo compound of the present invention has a transmittance of 45% to 60% in the base of the base material and an average transmittance of 440 nm to 500 nm of 50% And the average transmittance of 550 nm to 650 nm is 10% or less, which is obtained by measuring two substrates perpendicularly to the absorption axis direction. The polarizing plate of the present invention is characterized in that it does not inhibit luminescence of 440 nm to 500 nm, It can be seen that the degree of polarization of the light is high.

Fig. 4 shows the light emission intensity from the OLED display device when the transmittance of the polarizing plate of Example 3 is converted into the first Y-axis and the maximum intensity of the polarizing plate is taken as 100 on the second Y-axis. From the graph of FIG. 4, it can be seen from the graph of FIG. 4 that the base material having a polarizing function containing the azo compound of the present invention has a transmittance of 45% to 60% in the base of the base material and an average transmittance of 440 nm to 500 nm of 50% And the average transmittance of 550 nm to 650 nm is 10% or less, which is obtained by measuring two substrates perpendicularly to the absorption axis direction. The polarizing plate of the present invention is characterized in that it does not inhibit luminescence of 440 nm to 500 nm, It can be seen that the degree of polarization of the light is high.

5 shows the light emission intensity from the OLED display device when the transmittance of the polarizing plate of Example 6 is converted into the first Y-axis and the maximum intensity of the polarizing plate is taken as 100 on the second Y-axis. From the graph of Fig. 5, it can be seen from the graph of Fig. 5 that the substrate having a polarizing function containing the azo compound of the present invention and having a transmittance of 45% to 60% in the substrate itself and an average transmittance of 440 nm to 500 nm And the average transmittance of 550 nm to 650 nm is 10% or less, which is obtained by measuring two substrates perpendicularly to the absorption axis direction. The polarizing plate of the present invention is characterized in that it does not inhibit luminescence of 440 nm to 500 nm, It can be seen that the degree of polarization of the light is high.

6 shows the light emission intensity from the OLED display device when the transmittance of the polarizing plate of Example 7 is converted to the first Y-axis and the maximum intensity of the polarizing plate is converted to 100 on the second Y-axis. From the graph of FIG. 6, it can be seen from the graph of FIG. 6 that the base material having a polarizing function containing the azo compound of the present invention has a transmittance of 45% to 60% in the base of the base material and an average transmittance of 440 nm to 500 nm of 50% And the average transmittance of 550 nm to 650 nm is 10% or less, which is obtained by measuring two substrates perpendicularly to the absorption axis direction. The polarizing plate of the present invention is characterized in that it does not inhibit luminescence of 440 nm to 500 nm, It can be seen that the degree of polarization of the light is high.

7 shows the light emission intensity from the OLED display device when the transmittance of the polarizing plate of Example 8 is converted into the first Y-axis and the maximum intensity of the polarizing plate is taken as 100 on the second Y-axis. From the graph of FIG. 7, it can be seen from the graph of FIG. 7 that the base material having a polarizing function containing the azo compound of the present invention has a transmittance of 45% to 60% in the base material itself and an average transmittance of 440 nm to 500 nm of 50% And the average transmittance of 550 nm to 650 nm is 10% or less, which is obtained by measuring two substrates perpendicularly to the absorption axis direction. The polarizing plate of the present invention is characterized in that it does not inhibit luminescence of 440 nm to 500 nm, It can be seen that the degree of polarization of the light is high.

Fig. 8 shows the light emission intensity from the OLED display device when the transmittance of the polarizing plate of Comparative Example 1 is converted to the first Y-axis and the maximum intensity of the polarizing plate is converted to 100 to the second Y-axis. From the graph of FIG. 8, it can be seen that a polarizing plate having an average transmittance of 440 nm to 500 nm of a substrate of 50% or less is obtained. 8, the polarizing plate of Comparative Example 1 inhibits emission of 440 nm to 500 nm, lowering the luminance of the OLED, and luminescence of the phosphor by external light can not be sufficiently suppressed, so that the contrast is lowered .

As can be seen from the results of Tables 1 to 8 and 3 to 8 using the polarizing plates of Examples 1 to 8 and Comparative Example 1, the substrate having a polarizing function containing the azo compound of the present invention, And an average transmittance of 550 to 650 nm obtained by measuring the transmittance of the substrate in the range of 45 to 60%, the average transmittance of 440 to 500 nm of one substrate being 50% or more, It is understood that the polarizing element or the polarizing plate of 10% or less has high durability, improves the color expression of the OLED, and improves the contrast upon incidence of external light. In the display device having the color-light-emitting device using the polarizing element or the polarizing plate of the present invention, in particular, in OLED, not only high contrast, high reliability, high contrast and high color reproducibility can be provided.

Claims (25)

A polarizing element comprising a base material having a polarizing function and containing an azo compound, wherein a transmittance of the base material is 45% to 60%, an average transmittance of 440 nm to 500 nm is 50% And an average transmittance of 550 nm to 650 nm, which is obtained by measuring the polarized light perpendicularly to the axial direction, is 10% or less. The polarizing plate according to claim 1, wherein the base material having a polarizing function containing an azo compound has an average transmittance of 440 nm to 500 nm of 15% or more, which is obtained by measuring two substrates perpendicularly to the absorption axis direction, And an average transmittance of 550 nm to 650 nm is 40% or more. The polarizing plate according to any one of claims 1 to 3, wherein the average transmittance of 500 nm to 550 nm obtained by measuring two of the above-mentioned substrates perpendicularly to the absorption axis direction is 20% or less , And an average transmittance of 500 nm to 550 nm of one substrate is 45% or more. The polarizing element according to any one of claims 1 to 3, wherein the polarization degree is 60% or more. The polarizing element according to any one of claims 1 to 4, wherein at least one of the azo compounds contained in the substrate is in the form of a free acid and contains an azo compound represented by the formula (1).

Expression from, A ₁ represents a phenyl group or a naphthyl having a substituent, R ₁ denotes a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, sulfo, or sulfo, X ₁ is brought good substituents Phenylamino group. The polarizing element according to any one of claims 1 to 4, wherein at least one of the azo compounds contained in the substrate is in the form of a free acid and contains an azo compound represented by the formula (2).

In formula, A ₂ is a phenyl group having a substituent, R ₂ to R ₅ each independently, represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, or a sulfo group, X ₂ is a substituent Lt; RTI ID = 0.0 > phenylamino < / RTI > However, R ₂ to R ₅ do not satisfy that all of them are lower alkoxy groups at the same time. The polarizing element according to any one of claims 1 to 4, wherein at least one of the azo compounds contained in the substrate is in the form of a free acid and contains an azo compound represented by the formula (3).

A ₃ represents a nitro group or an amino group, R ₆ and R ₇ each independently represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, X ₃ represents a substituent Lt; RTI ID = 0.0 > phenylamino < / RTI > The optical sheet according to any one of claims 1 to 7, wherein an average transmittance of 500 to 550 nm is 15% or less and a transmittance of 440 nm to 500 nm An average transmittance of 60% or more, and an average transmittance of 500 to 550 nm of 45% or more. The azo compound according to any one of claims 1 to 8, wherein at least one of the azo compounds contained in the base material together with at least one of the azo compounds represented by formulas (1) to (3) , And an azo compound represented by the formula (4).

Wherein A ₄ represents a phenyl group having a substituent or a naphthyl group and R ₈ or R ₉ each independently represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, X ₄ represents an amino group which may have a substituent, a benzoylamino group which may have a substituent, a phenylamino group which may have a substituent, a phenylazo group which may have a substituent, or a naphthotriazole group which may have a substituent. The polarizing element according to claim 9, wherein X ₄ in the formula (4) is a phenylamino group which may have a substituent. The polarizing element according to claim 9 or 10, wherein A ₄ in the formula (4) is a phenyl group having a substituent. The azo compound according to any one of claims 1 to 8, wherein at least one of the azo compounds contained in the base material is in the form of free acid, together with any one of the azo compounds represented by the general formulas (1) to (3) A polarizing element characterized by containing an azo compound represented by the formula (5).

In the formula, R ₁₀ and R ₁₁ each independently represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group, a lower alkoxy group having a sulfo group, a carbonyl group or a phenyl group or a naphthyl group having a halogen atom. A compound according to claim 12, wherein R ₁₀ and R _{11 in} the formula (5) each independently represent a lower alkoxy group having a hydrogen atom, a lower alkyl group, a lower alkoxy group, a sulfo group or a sulfo group, a carbonyl group, And is a phenyl group. The polarizing element according to claim 13, wherein R ₁₀ and R ₁₁ are each independently, at least one substituent is a methoxy group, and the other substituent is a sulfo group or a carbonyl group. The polarizing element according to any one of claims 5 and 8 to 14, wherein R _{1 in the} formula (1) is a methyl group or a methoxy group. The polarizing element according to any one of claims 5, 8 and 15, wherein A _{1 in the} formula (1) is a phenyl group having a substituent. The polarizing element according to any one of claims 6 to 14, wherein at least one of R ₄ and R _{5 in} the formula (2) is a methoxy group. The polarizing element according to any one of claims 6, 8 to 14 or 17, wherein at least one of R ₂ or R _{3 in} the formula (2) is a methoxy group. The polarizing element according to any one of claims 6, 8 to 15, 17 or 18, wherein A ₂ in the formula (2) is a phenyl group having a substituent. The polarizing element according to any one of claims 7 to 15, wherein at least one of R ₆ and R _{7 in} the formula (3) is a methoxy group. The polarizing element according to any one of claims 7 to 15 or 20, wherein R ₆ and R _{7 in} the formula (3) are methoxy groups. The polarizing element according to any one of claims 1 to 21, wherein the substrate comprises a polyvinyl alcohol-based resin film.  The polarizing plate according to any one of claims 1 to 22, which is obtained by providing a support film on at least one surface of a polarizing element. The polarizing plate according to any one of claims 1 to 22 or the polarizing plate according to claim 23, which is provided with a retarder having a retardation of 120 to 150 nm. An organic electroluminescent display device using the polarizing element according to any one of claims 1 to 22, or the polarizing plate according to any one of claims 23 to 24.

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