JP7336964B2 - optical control system - Google Patents

Description

The present invention relates to an optical control system that emits polarized light with high brightness and a display device using the same.

A polarizing plate having a function of transmitting or blocking light is a basic component of a display device such as a liquid crystal display (LCD) together with a liquid crystal having a function of switching light. The fields of application of LCDs are expanding from small devices such as calculators and clocks in the early days of the market to laptop computers, word processors, liquid crystal projectors, liquid crystal televisions, car navigation systems, indoor and outdoor information display devices, measuring instruments, and the like. In addition, polarizing plates can also be applied to lenses that have a polarizing function, and have been applied to sunglasses with improved visibility, and in recent years, to polarized glasses that are compatible with 3D televisions, etc. Weara Blue It is being applied to terminals and other familiar information terminals, and some of them are being put to practical use. Polarizing plates are used in a wide variety of applications, and their operating environments are wide ranging from low to high temperatures, low to high humidity, and low to high light intensity. A polarizing plate is desired.

In general, the polarizing film contained in the polarizing plate is obtained by dyeing or containing iodine or a dichroic dye in a film of stretched and oriented polyvinyl alcohol or a derivative thereof, or by dehydrochlorinating a polyvinyl chloride film or It is produced by being a polyene-based film in which polyene is produced by dehydration and oriented. Since the produced polarizing plate contains iodine and dichroic dyes that absorb in the visible region, the transmittance generally decreases. For example, the transmittance of common commercially available polarizing plates is 35 to 45%.

In addition, regarding the "degree of polarization", which is one of the indices indicating the polarization performance of a polarizing plate, in order to achieve a degree of polarization of 100%, when the x-axis and y-axis lights exist on a two-dimensional plane, one Only axial light needs to be absorbed. Therefore, a general polarizing plate uses iodine or a dichroic dye to absorb only one axis of light. If only one axis of light is absorbed, the amount of light transmitted through the polarizing plate is theoretically 50% or less with respect to the amount of incident light of 100%. Furthermore, due to a decrease in the degree of polarization due to poor orientation of iodine and dichroic dyes, light loss due to the film medium, interfacial reflection on the film surface, etc., the actual transmittance is even lower than 50%. , the transmittance of the conventional polarizing plate is as low as 35 to 45%. In order to solve the problem that the transmittance of general polarizing plates is as low as 35 to 45%, a polarizing plate for ultraviolet rays is developed as a technology for imparting a polarizing function while maintaining a certain degree of transmittance in the visible range. is described in Patent Document 1. However, the polarizing plate obtained by this technique is colored yellow, and only a polarizing plate that exhibits a polarizing function only for light around 410 nm can be provided. In other words, it does not impart a polarizing function to light in the visible range, which is highly visible.

If a polarizing plate with a low transmittance of light in the visible region or a polarizing plate with a low degree of polarization is used in a display, for example, the brightness and contrast of the entire display are lowered. In order to solve this problem, a method of obtaining polarized light without using a conventional polarizing plate has been researched, and as one of the methods, an element that emits polarized light (polarized light emitting element) is described in Patent Documents 2 to 6. It is

WO2005/001527 JP 2008-224854 A Japanese Patent No. 5849255 Japanese Patent No. 5713360 U.S. Pat. No. 3,276,316 JP-A-4-226162

However, the polarized light-emitting elements described in Patent Documents 2 to 4 use special metals such as europium and other lanthanoids, which are highly scarce, and therefore have high manufacturing costs and are difficult to mass-produce. is unsuitable for In addition, these polarized light emitting devices have a low degree of polarization, making it difficult to use them in displays, and it is difficult to obtain emitted light that is linearly polarized. In addition, since only circularly polarized light of a specific wavelength can be obtained, the application is limited, and even if it is used in a display, both brightness and contrast are low, and it is difficult to design a liquid crystal cell. Therefore, a new polarizing plate that exhibits polarized light emission, has high polarized light emission intensity, high transmittance in the visible light region, and can be applied to liquid crystal displays, etc. that require durability in harsh environments, and Development of materials used for it is strongly desired. On the other hand, Patent Documents 5 and 6 disclose patents relating to devices that emit polarized light by irradiating ultraviolet rays. However, the degree of polarization and brightness of the light-emitting element are extremely low, and the so-called polarization contrast is low, so that it is not sufficient for use in displays and the like, and in addition, its light resistance is also low.

The present invention emits polarized light that can be applied to liquid crystal displays, etc. that require high durability in harsh environments while emitting light having a high degree of polarization while having high polarized light emission luminance. An object of the present invention is to provide an optical control system, a polarizing plate using the same, and a display device.

The inventors of the present invention have made intensive studies to achieve this object, and as a result, a layer (A) that absorbs light in the near-ultraviolet to near-ultraviolet visible region and emits light using the absorbed light, and the layer A layer (B) that has absorption in the wavelength range of the light emitted by (A) and emits polarized light having a wavelength in the visible range using the light emitted by the layer (A). The inventors have found that the optical control system can emit polarized light with high brightness and have high durability, and have completed the present invention.

That is, the present invention relates to 1) to 12).
1)
A layer (A) that absorbs light in the near-ultraviolet to near-ultraviolet visible region and emits light using the absorbed light; ), and a layer (B) that emits polarized light having a wavelength in the visible range by using the light emitted by (B).
2)
1) The optical control system according to 1), wherein the layer (A) contains a compound (a) that absorbs light in a wavelength range of at least 300 to 360 nm and emits light having an emission wavelength in a wavelength range of at least 350 to 430 nm. .
3)
1) or 2), wherein the layer (B) contains a compound (b) that absorbs light in a wavelength range of at least 350 to 430 nm and emits light having an emission wavelength in a wavelength range of at least 400 to 700 nm. Optical control system.
4)
The optical control system according to any one of 1) to 3), wherein the light emitted by the layer (B) is linearly polarized light.
5)
The optical control system according to any one of 1) to 4), wherein the layer (A) is laminated on at least one side of the layer (B).
6)
The optical control system according to 5), wherein the layer (A) is laminated only on one side of the layer (B), and the layer (A) is provided on the light incident side.
7)
The optical control system according to any one of 1) to 5), wherein the layer (A) is laminated on both sides of the layer (B).
8)
The optical control system according to any one of 3) to 7), wherein the compound (b) is a compound having absorption anisotropy.
9)
The optical control system according to any one of 2) to 8), wherein the compound (a) is a compound having emission anisotropy.
10)
10. The optical system according to any one of claims 3 to 9, wherein the compound (b) has in its molecule at least one skeleton selected from the group consisting of a stilbene skeleton, a biphenyl skeleton and a coumarin skeleton. control system.
11)
A polarized light-emitting plate comprising the optical control system according to any one of 1) to 10).
12)
A display device comprising the optical control system according to any one of 1) to 10) or the polarized light emitting plate according to 11).

INDUSTRIAL APPLICABILITY The optical control system according to the present invention is capable of utilizing incident light with high efficiency, exhibiting a high polarizing effect at the emission wavelength, exhibiting a high-intensity light emitting effect, and imparting high durability. can. According to the present invention, highly efficient light emission can be achieved by converting the wavelength of light into the absorption wavelength of a dye that can absorb natural light or artificial light with high efficiency and provide polarized light emission. It is possible to provide an optical control system having high emission luminance while having high transmittance in the visible light region. Furthermore, it is generally known that polymers and dyes are degraded by certain light such as ultraviolet light. To provide an optical control system capable of substantially suppressing , imparting high durability to the element itself, and being suitably used for a display device, such as a liquid crystal display, in which particularly high light resistance is required. up to.

The present invention includes a layer (A) that absorbs light in the near-ultraviolet to near-ultraviolet visible range and emits light using the absorbed light, and a layer (A) that absorbs light in the wavelength range of light emitted by the layer (A). , and a layer (B) that absorbs part or all of the light emitted by the layer (A) and uses the absorbed light to emit polarized light having a wavelength in the visible region, An optical control system, a polarized light emitting plate comprising the same, and a display device comprising any of them are obtained.

As the light absorption band in the layer (A), it preferably absorbs light having an emission wavelength in the near-ultraviolet to near-ultraviolet-visible region, and does not inhibit the light emission of the layer (B), which emits substantially in the visible region. , and can increase the brightness of the layer (A). In addition, when the layer (A) absorbs light in the near-ultraviolet to near-ultraviolet-visible region, it is generally used as a layer that absorbs the energy of ultraviolet light that causes deterioration of the device and uses the energy mainly for light emission. Since it functions, deterioration of the layer (A) and deterioration of other layers can also be suppressed. The preferred light in the near-ultraviolet to near-ultraviolet-visible region, which is light absorbed by the layer (A), is light in the band of 300 to 360 nm. This band is generally regarded as the ultraviolet region, and is known to be difficult for the human eye to perceive.

In order to obtain the layer (A), the compound in the layer (A) has a light absorption action in the near-ultraviolet to near-ultraviolet visible region, and can convert the wavelength of light to emit light. or forming a layer of a substance having the same function (hereinafter referred to as compound (a)). Methods for forming a layer containing the compound (a) include, for example, a method in which the compound (a) is incorporated in a polymer, a thermosetting resin, or a photocurable resin to form a coating on a layer or film, and an existing film. When bonding the layer (B) to an arbitrary film such as a protective film or a substrate such as glass, an adhesive containing the compound (a) is used to form a layer as an adhesive layer. A method of forming (A), a method of forming the layer (A) when the adhesive contains the compound (a) and the layer (B) is laminated to a protective film such as an arbitrary film or a substrate such as glass. Alternatively, a method of forming a layer (A) as an adhesive layer containing the compound (a) or an adhesive layer in the case of lamination with a display device is exemplified, but the method is not limited thereto. Moreover, the compound (a) is preferably a compound having emission anisotropy.

The emission wavelength of the layer (A) is not particularly limited, and may be light in the near-ultraviolet to near-ultraviolet visible region, or light in the visible region of 400 to 700 nm. The emission wavelength partially or wholly overlaps with the absorption wavelength of the layer (B), which will be described later, so that the emission luminance of the layer (B) can be enhanced. However, since it is a preferred form not to affect the polarized light emission of the layer (B), the emission wavelength of the layer (A) is from near ultraviolet to near ultraviolet that does not reduce the brightness of the visible polarized light emission of the layer (B). Light in the visible region is preferable, or light capable of making visible polarized light emitted from the layer (B) have a higher degree of polarization. In particular, by containing a substance capable of absorbing light at least in the range of 300 to 360 nm and capable of emitting light in the range of 350 to 430 nm, the layer (B) provides light that is hardly visible to the human eye. can be achieved to emit more intense light. The compound (a) is preferably a substance capable of absorbing light of 300 to 360 nm and capable of emitting light of 350 to 430 nm. Examples of the compound (a) include 2-(2-pyridylamino)ethylamine dihydrochloride (absorbs light at 300 nm and emits light at 380 nm), 9,10-phenanthrenequinone (absorbs light at 310 nm, 365 nm light), diphenyl-1-perenylphosphine (which absorbs 352 nm light and emits 380 nm light), etc. can be used, but are not particularly limited. Especially in recent years, quantum dots, so-called quantum dots, have been developed, and it is known that quantum dot particles can provide similar functions. For example, gold quantum dots Au 5-8 (excitation wavelength: 330 nm, emission wavelength: 405 nm) manufactured by Dainippon Toryo Co., Ltd., but not limited to these substances, can be used regardless of inorganic or organic substances. The compound (a) can be used alone or in combination.

A preferable form of the layer (A) is a layer (A) containing a compound (a) that absorbs light in a wavelength range of at least 300 to 360 nm and emits light having an emission wavelength in a wavelength range of at least 350 to 430 nm. It is mentioned that it is. In the absorption of the layer (A), it is preferable that there is an absorption band in the range of 300 to 360 nm. It is possible to provide the layer (A) with light absorption that does not affect the light emission of the layer (B). In addition, the compound (a) has different absorption wavelengths and emission wavelengths, and the emission wavelength range is several tens of nm from the highest emission wavelength, for example, the highest emission wavelength ± 30 nm. More preferably, the highest emission wavelength is on the long wavelength side of 20 nm or more with respect to the highest absorption wavelength. That is, the layer (A) has a light absorption wavelength range of 300 to 360 nm and an emission wavelength range of 350 to 430 nm, so that it is substantially invisible to the human eye or difficult to see, and In the emission of polarized light in the visible region of the layer (B), it is possible to further increase the brightness and provide emission with a high degree of polarization.

The layer (B) is not only capable of absorbing light in the ultraviolet to visible light range, but also utilizes the light emitted by the layer (A) to emit polarized light having a wavelength in the visible range ( polarized light-emitting device). The layer (B) preferably contains a compound (b) that absorbs light in the wavelength range of at least 350 to 430 nm and emits light having an emission wavelength in the wavelength range of at least 400 to 700 nm. It is more preferable to form a layer of the compound (b) which has a light absorption action in the near-ultraviolet visible region and can convert the wavelength of light of that wavelength to emit polarized light. By having a light absorption action in the near-ultraviolet to near-ultraviolet visible range, it is possible to provide an element with high transmittance without absorbing light in the visible range. In other words, it is possible to provide an element capable of emitting polarized light in the visible range in spite of its high transmittance. A preferred embodiment of the layer (B) is a layer (B) containing a compound (b) having an absorption range of at least 350 to 430 nm and capable of emitting polarized light in a wavelength range of at least 400 to 700 nm. be able to. In the absorption of the layer (B), it is one of the preferred forms that there is absorption at 350 to 430 nm, and the light absorption wavelength and emission wavelength of the layer (A) are in the ultraviolet region to the near-ultraviolet-visible region, respectively. Therefore, it is possible to provide an element that emits polarized light in the visible range while having a high transmittance. Among them, when the wavelength at which the layer (B) exhibits the highest absorption is in the range of 350 to 430 nm, light is absorbed extremely efficiently, and the light is absorbed, and light emission using the absorbed light is possible. It is particularly preferred because it can provide bright polarized light.

The layer (A) and the layer (B) are preferably configured as adjacent layers in the optical control system. The contact is preferable because, for example, optical loss such as no reflection of light at the layer interface can be reduced. However, the layer (A) and the layer (B) do not necessarily have to be in direct contact. Since the optical control system includes the layer (A) and the layer (B), the layer (A) absorbs light incident from the outside, and the absorbed light is used to emit light from the layer (A). is absorbed by the layer (B) together with external light, and the absorbed light emitted by the layer (A) is also used to emit polarized light from the layer (B).

As for the positional relationship between the layer (A) and the layer (B), when the layer (A) and the layer (B) are configured as layers in contact with each other, the light emitted by the layer (A) is transferred to the layer (B). is preferable because the light loss due to interface reflection can be reduced and the layer (A) can be efficiently absorbed, and it is preferable that the layer (A) is laminated on at least one side of the layer (B). In addition, since the layer (A) is arranged on the light incident side, for example, the light source side with respect to the layer (B), the layer (A) efficiently absorbs the light from the light source, and furthermore, The layer (B) can efficiently absorb light emitted from the layer (A). In addition, when the light absorption of the layer (A) is not complete, that is, when there is leakage light from the light source from the layer (A), ambient light, for example, the layer (A) and the layer (A) from an arbitrary direction When external light is incident from both sides of the optical control system, such as when B) is irradiated with light that can be absorbed, by providing layer (A) on both sides of layer (B), both sides Since the layer (A) disposed in the layer (A) absorbs light and emits light, respectively, and can transmit light to the layer (B), the light utilization efficiency can be further increased.

The light emitted by the layer (B) is preferably linearly polarized light. Since the layer (B) is a layer that emits linearly polarized light, there is an advantage that a display device such as a liquid crystal display can be easily designed. Linearly polarized light is light that can also be represented as a wave in the direction of a fixed axis. By emitting linearly polarized light, that is, uniaxially polarized light, the degree of freedom in designing a display device such as a liquid crystal display increases. Many commercially available liquid crystal displays and polarized lenses use iodine-based polarizing plates and dye-based polarizing plates that can provide linearly polarized light, that is, polarizing plates using a dichroic dye having uniaxial absorption. Therefore, it can be easily considered that linearly polarized light is suitable for industrial use. On the other hand, if we try to use circularly polarized light or elliptically polarized light, the design of the liquid crystal cell, or the alignment of the liquid crystal used therein, becomes complicated, or the design of the retardation plate becomes extremely complicated. It is preferable that the polarized light is linearly polarized light because industrial use becomes difficult. Emission of linearly polarized light can be achieved by orienting the compound (b) in the same direction. In addition, by using the compound (b) and emitting light with polarized light in the same direction, the emission intensity of the layer (B) is increased, and is higher than the emission intensity of the compound (b) in an aqueous solution at the same concentration. to the extent that it can provide strong light.

The compound (b) is preferably a compound having absorption anisotropy in the light absorbing band. By orienting the compound (b) in the layer (B), it is possible to provide stronger light than the original emission intensity of the compound (b). It is preferable to have absorption anisotropy in addition to the light emission function. Absorption anisotropy is generally indicated as a dichroic ratio (hereinafter also referred to as RD), and the degree of orientation of the dye (hereinafter sometimes referred to as Order Parameter) is calculated from this dichroic ratio. can be done. The dichroic ratio is the ratio of the absorption amount of the axis with the strongest absorption to the absorption amount of the axis with the lowest absorption. is possible, preferably 10 or more, preferably 20 or more, more preferably 30 or more, and particularly preferably 40 or more. The degree of orientation is a numerical value given by the following formula (I), and is preferably 0.85 or more and 1.00 or less, and particularly preferably 0.90 or more and 0.96 or less. It is preferable to measure the dichroic ratio in a layer containing the compound (b), that is, in the measurement of the polarized light emitting device, in the absence of interface reflection. The above compound (b) can be used alone or in combination.

(Formula 1)
Order Parameter=(RD−1)/(RD+2) Formula (I)

As a preferred form of the layer (B), the compound (b) has at least one skeleton selected from the group consisting of a stilbene skeleton, a biphenyl skeleton, and a coumarin skeleton in its molecule, and the compound (b) is a layer (B) is oriented. An example of the manufacturing method is shown below.

<Base material>
The polarized light-emitting device uses a polymer film as a base material for adsorbing and orienting a polarized light-emitting dye, which will be described later. The polymer film is preferably formed from a hydrophilic polymer capable of adsorbing a general dichroic polarized light-emitting dye, particularly a dye having a stilbene skeleton, a dye having a biphenyl skeleton, or a dye having a coumarin skeleton. It is a hydrophilic polymer film obtained by Although the hydrophilic polymer is not particularly limited, for example, polyvinyl alcohol-based resins and starch-based resins are preferable. Resins and derivatives thereof are preferred. Examples of the above-mentioned polyvinyl alcohol-based resins and derivatives thereof include polyvinyl alcohol and derivatives thereof, and olefins such as ethylene and propylene, and inerts such as crotonic acid, acrylic acid, methacrylic acid, and maleic acid. Examples include those modified with saturated carboxylic acid or the like. Among them, a film made of polyvinyl alcohol or a derivative thereof is preferably used from the viewpoint of adsorption and orientation of a dichroic polarized light-emitting dye. The base material may be, for example, a film made of a commercially available polyvinyl alcohol-based resin or a derivative thereof, or may be produced by forming a polyvinyl alcohol-based resin into a film. The film-forming method of the polyvinyl alcohol-based resin is not particularly limited. After gelling, the solvent is removed by extraction), a cast film forming method (an aqueous solution of polyvinyl alcohol is poured onto a substrate and dried), and a method using a combination of these known film forming methods can be employed. The thickness of the substrate is usually 10-100 μm, preferably about 20-80 μm.

<Method for producing polarized light-emitting element>
The method for producing the polarized light emitting element is not limited to the following production method, but it is preferable to use a film made of polyvinyl alcohol or a derivative thereof, and a film made of polyvinyl alcohol or a derivative thereof is preferably used. A method for manufacturing a polarized light-emitting element will be described with an example of using it.
The method for producing the polarized light-emitting device includes a step of preparing a base material, a swelling step of immersing the base material in a swelling liquid to swell the base material, and applying the swollen base material to a polarized light-emitting dye described later. A dyeing step of impregnating the substrate with a dyeing solution containing at least the above and adsorbing the polarized light-emitting dye to the substrate, and immersing the substrate adsorbed with the polarized light-emitting dye in a solution containing boric acid to make the polarized light-emitting dye into the substrate. A cross-linking step of cross-linking in a washing solution, a stretching step of uniaxially stretching the substrate crosslinked with the polarized light-emitting dye in a certain direction to arrange the polarized light-emitting dye in a certain direction, and optionally washing the stretched substrate with a washing solution. and/or a drying step to dry the washed substrate.

(Swelling process)
The swelling step will be described. The swelling step is preferably carried out by immersing the substrate in a swelling liquid of 20 to 50° C. for 30 seconds to 10 minutes, and the swelling liquid is preferably water. The stretching ratio of the substrate with the swelling liquid is preferably adjusted to 1.00 to 1.50 times, more preferably 1.10 to 1.35 times.

(Dyeing process)
The dyeing process will be described. One or more polarized light-emitting dyes, which will be described later, are adsorbed on the substrate obtained through the swelling step. The dyeing step is not particularly limited as long as it is a method capable of adsorbing the following polarized light-emitting dye to the substrate. For example, the substrate is immersed in a dyeing solution containing the polarized light-emitting dye, or A method of applying a dyeing solution containing a polarized light-emitting dye to the substrate is preferred, but a method of immersing the substrate in a dyeing solution containing a polarized light-emitting dye is preferred. The concentration of the polarized light-emitting dye in the staining solution is not particularly limited as long as the polarized light-emitting dye is sufficiently adsorbed on the substrate. For example, the concentration of the polarized light-emitting dye in the staining solution is It is preferably 0.0001 to 1% by mass, more preferably 0.0001 to 0.5% by mass. The temperature of the dyeing solution in the dyeing step is preferably 5 to 80°C, more preferably 20 to 50°C, and particularly preferably 40 to 50°C. Also, the time for immersing the substrate in the dyeing solution can be adjusted as appropriate, preferably between 30 seconds and 20 minutes, more preferably between 1 and 10 minutes. The polarized light-emitting dyes contained in the dyeing solution may be used singly or in combination of two or more. Since the polarized light-emitting dyes to be described later have different emission colors depending on the difference in the dye structure, etc., by incorporating two or more types of polarized light-emitting dyes into the base material, the emitted light colors are appropriately adjusted to various colors. be able to. In addition, if necessary, the dyeing solution may further contain one or more organic dyes and/or fluorescent dyes in addition to the polarized light-emitting dyes described below.

(Polarized luminescent dye)
Examples of the polarized light-emitting dye include those that emit fluorescence or phosphorescence, and can be used as the compound (b). The dye is preferably a compound or a salt thereof that has at least one skeleton selected from the group consisting of a stilbene skeleton, a biphenyl skeleton, and a coumarin skeleton in the molecule and emits light using absorbed light. It is mentioned as. Those that emit fluorescent light or phosphorescent light are preferable, but the polarized light emitting dye has a fluorescence emitting function and has a dichroic ratio at the absorption wavelength of light, so that more highly polarized light can be emitted. can emit light. In particular, a polarized light-emitting dye having a stilbene skeleton, a biphenyl skeleton, or a coumarin skeleton in the dye molecule has excellent fluorescence emission characteristics and, by orientation, a high dichroic ratio at the absorption wavelength. These properties are derived from the properties of each of the above skeletons, and further improve these properties, and adjust various properties such as absorption wavelength, emission wavelength, light resistance, moisture resistance, ozone gas resistance, and other robustness and solubility. Depending on the purpose, it is possible to further introduce arbitrary substituents into each of the above skeletons. In the introduction of substituents, if the selection of the type of substituent or the position of substitution is not preferable, the amount of emitted light will be significantly reduced, even if a high degree of polarization can be achieved, as with conventional dye-based polarizing plates. In order to obtain excellent fluorescence emission properties and a high dichroic ratio, the selection of the type of substituent and the substitution position is particularly important. In addition, the polarized light-emitting dyes may be used singly or in combination of two or more.

(b-1) Dye Having a Stilbene Skeleton The dye having a stilbene skeleton is preferably a compound represented by the following formula (1) or a salt thereof.

In the above formula (1), L and M are each independently a nitro group, an optionally substituted amino group, an optionally substituted carbonylamide group, an optionally substituted Naphthotriazole group, optionally substituted alkyl group having 1 to 20 carbon atoms, optionally substituted vinyl group, optionally substituted amide group, optionally substituted Although it represents a ureido group, an aryl group which may have a substituent, and a carbonyl group which may have a substituent, it is not necessarily limited to these. Dyes having a stilbene skeleton represented by formula (1) are known to emit fluorescence and to obtain dichroism by orientation, which is mainly derived from the stilbene skeleton. and any substituent may be introduced. However, if the stilbene skeleton has an azo group at the L-position and the M-position, the fluorescence emission is significantly reduced, which is not preferable.

Examples of the amino group which may have a substituent include unsubstituted amino group, methylamino group, ethylamino group, n-butylamino group, tertiarybutylamino group, n-hexylamino group, dodecylamino dimethylamino group, diethylamino group, di-n-butylamino group, ethylmethylamino group, ethylhexylamino group, an optionally substituted alkylamino group having 1 to 20 carbon atoms, phenylamino group, diphenyl Substitution such as an arylamino group optionally having a substituent such as an amino group, a naphthylamino group, an N-phenyl-N-naphthylamino group, a methylcarbonylamino group, an ethylcarbonylamino group, and an n-butyl-carbonylamino group optionally substituted arylcarbonylamino group such as alkylcarbonylamino group having 1 to 20 carbon atoms which may have a group, phenylcarbonylamino group, biphenylcarbonylamino group, naphthylcarbonylamino group, methylsulfonylamino group, an alkylsulfonylamino group having 1 to 20 carbon atoms such as an ethylsulfonylamino group, a propylsulfonylamino group, and n-butyl-sulfonylamino group, a phenylsulfonylamino group, a naphthylsulfonylamino group, and the like. arylsulfonylamino, etc., optionally substituted alkylcarbonylamino groups having 1 to 20 carbon atoms, optionally substituted arylcarbonylamino groups, and alkylsulfonylamino groups having 1 to 20 carbon atoms. It is preferably an arylsulfonylamino group which may have a group or a substituent. In addition, the alkylamino group optionally having 1 to 20 carbon atoms, the arylamino group optionally having a substituent, and the alkylcarbonylamino group optionally having 1 to 20 carbon atoms There are no particular restrictions on the substituents in the group, an optionally substituted arylcarbonylamino group, an alkylsulfonylamino group having 1 to 20 carbon atoms, and an optionally substituted arylsulfonylamino group, Examples include nitro group, cyano group, hydroxyl group, sulfonic acid group, phosphoric acid group, carboxy group, carboxyalkyl group, halogen atom, alkoxy group, aryloxy group and the like.

Examples of the carboxyalkyl group include a methylcarboxy group and an ethylcarboxy group. Halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Alkoxy groups include methoxy, ethoxy, and propoxy groups. The aryloxy group includes a phenoxy group, a naphthoxy group and the like. Examples of the carbonylamido group which may have a substituent include N-methyl-carbonylamido group (--CONHCH ₃ ), N-ethyl-carbonylamido group (--CONHC ₂ H ₅ ), N-phenyl-carbonyl An amide group (--CONHC ₆ H ₅ ) and the like can be mentioned. Examples of the naphthotriazole group which may have a substituent include a benzotriazole group and a naphthotriazole group. Examples of the alkyl group having 1 to 20 carbon atoms which may have a substituent include straight alkyl groups such as methyl group, ethyl group, n-butyl group, n-hexyl group, n-octyl group and n-dodecyl group. Examples include branched chain alkyl groups such as chain alkyl groups, isopropyl groups, sec-butyl groups and tertiary butyl groups, and cyclic alkyl groups such as cyclohexyl groups and cyclopentyl groups. Examples of the vinyl group which may have a substituent include a vinyl group, a methylvinyl group, an ethylvinyl group, a divinyl group, a pentadiene group and the like. Examples of the amide group which may have a substituent include an acetamide group (--NHCOCH ₃ ) and a benzamide group (--NHCOC ₆ H ₅ ). Examples of the aryl group which may have a substituent include a phenyl group, a naphthyl group, an anthracenyl group, and a biphenyl group. Examples of the carbonyl group which may have a substituent include a methylcarbonyl group, an ethylcarbonyl group, an n-butyl-carbonyl group, a phenylcarbonyl group and the like. A carbonylamide group optionally having a substituent, a naphthotriazole group optionally having a substituent, an alkyl group having 1 to 20 carbon atoms optionally having a substituent, and optionally having a substituent As a substituent for a vinyl group, an amide group optionally having a substituent, a ureido group optionally having a substituent, an aryl group optionally having a substituent, and a carbonyl group optionally having a substituent is not particularly limited, but may be the same as the substituents described in the section on the optionally substituted amino group.

The dye having a stilbene skeleton represented by the above formula (1) is particularly preferably a dye represented by the following formula (2) or a salt thereof, or a dye represented by the following formula (3) or a salt thereof. By using these dyes, it is possible to obtain a polarized light-emitting device that emits brighter, brighter, and more polarized white light.

In the above formula (2), the substituent R is a hydrogen atom, a chlorine atom, a bromine atom, or a halogen atom such as a fluorine atom, a hydroxyl group, a carboxyl group, a nitro group, an optionally substituted alkyl group, or a substituent. It represents an alkoxy group which may have, or an amino group which may have a substituent. Halogen atoms may be the same as those described above. The alkyl group which may have a substituent may be the same as those described in the section on the alkyl group having 1 to 20 carbon atoms which may have a substituent. The alkoxy group which may have a substituent is preferably a methoxy group, an ethoxy group, or the like. The amino group which may have a substituent may be the same as described above, and is preferably a methylamino group, a dimethylamino group, an ethylamino group, a diethylamino group, a phenylamino group, or the like. The substituent R may be bonded to any carbon of the naphthalene ring in the naphthotriazole ring, but when the carbon condensed with the triazole ring is the 1- and 2-positions, the 3-position, 5-position, or Bonding to the 8-position is preferred. n is an integer of 0-3, preferably 1 or 2; The —(SO ₃ H) group may be attached to any carbon of the naphthalene ring in the naphthotriazole ring. —(SO ₃ H) group is substituted on the naphthalene ring when n=1, the 4-position, 6-position or 7-position when the carbon condensed with the triazole ring is the 1-position and the 2-position. and preferably at positions 5 and 7, and 6 and 8 when n=2, and a combination of positions 3, 6 and 8 when n=3. is preferred. Moreover, it is particularly preferable that R is a hydrogen atom and n is 1. X represents a nitro group or an optionally substituted amino group, preferably a nitro group. The amino, which may have a substituent, may be the same as described above, an alkylcarbonylamino group having 1 to 20 carbon atoms which may have a substituent, an arylcarbonylamino group which may have a substituent, An alkylsulfonylamino group having 1 to 20 carbon atoms or an optionally substituted arylsulfonylamino group is preferred.

Y in the above formula (3) represents an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted vinyl group, or an optionally substituted aryl group. , preferably an aryl group which may have a substituent, more preferably a naphthyl group which may have a substituent, and a naphthyl group substituted with an amino group and a sulfo group as a substituent. is particularly preferred. Z represents the same substituent as described for X in formula (2) above, preferably a nitro group.

Examples of the compound represented by formula (1) include the Kayaphor series (manufactured by Nippon Kayaku Co., Ltd.) and the Whitex series such as Whitex RP (manufactured by Sumitomo Chemical Co., Ltd.). In addition, the compounds represented by formula (1) are exemplified below, but are not limited to these.

(b-2) Dye Having Biphenyl Skeleton The dye having a biphenyl skeleton is preferably a compound represented by the following formula (4) or a salt thereof.

In the above formula (4), P and Q are each independently a nitro group, an optionally substituted amino group, an optionally substituted carbonylamide group, an optionally substituted Naphthotriazole group, optionally substituted alkyl group having 1 to 20 carbon atoms, optionally substituted vinyl group, optionally substituted amide group, optionally substituted It represents, but is not necessarily limited to, a ureido group, an aryl group which may have a substituent, or a carbonyl group which may have a substituent. optionally substituted amino group, optionally substituted carbonylamide group, optionally substituted naphthotriazole group, optionally substituted C 1-20 alkyl A vinyl group optionally having substituents, an amide group optionally having substituents, an aryl group optionally having substituents, and a carbonyl group optionally having substituents are the same as above. OK. However, having an azo group at the P position and/or the Q position of the biphenyl skeleton in formula (4) above is not preferable because fluorescence emission is significantly reduced.

The compound represented by the above formula (4) is preferably a compound represented by the following formula (5).

In the above formula (5), j represents an integer of 0-2. The preferred substitution position of the —(SO ₃ H) group is not particularly limited, but when the vinyl group is the 1st position, the 2nd and 4th positions are preferred, and the 2nd position is particularly preferred.

In the above formula (5), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an aralkyloxy group, an alkenyloxy , an alkylsulfonyl group having 1 to 4 carbon atoms, an arylsulfonyl group having 6 to 20 carbon atoms, a carbonamide group, a sulfonamide group, and a carboxyalkyl group. The carboxyalkyl group may be the same as described above.

Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, tertiary-butyl group and cyclobutyl group. Examples of the alkoxy group having 1 to 4 carbon atoms include methoxy group, ethoxy group, propoxy group, n-butoxy group, sec-butoxy group, tertiary butoxy group and cyclobutoxy group. Examples of the aralkyloxy group include aralkyloxy groups having 7 to 18 carbon atoms. Examples of the alkenyloxy group include alkenyloxy groups having 1 to 18 carbon atoms. Examples of the alkylsulfonyl group having 1 to 4 carbon atoms include methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, n-butylsulfonyl group, sec-butylsulfonyl group, tertiarybutylsulfonyl group and cyclobutylsulfonyl group. be done. Examples of the arylsulfonyl group having 6 to 20 carbon atoms include a phenylsulfonyl group, a naphthylsulfonyl group and a biphenylsulfonyl group.

In the above formula (5), preferred substitution positions of R ₁ to R ₄ are preferably the 2nd and 4th positions when the vinyl group is the 1st position.

A method for synthesizing the polarized light-emitting dye represented by the above formula (5) will be described below.

The polarized light-emitting dye represented by formula (5) above can be prepared by a known method, for example, by condensing 4-nitrobenzaldehyde-2-sulfonic acid with a phosphonate and then reducing the nitro group.

As the compound represented by formula (5), compounds described in JP-A-4-226162 can be used, and specific examples include the following compounds.

(b-3) Pigment Having a Coumarin Skeleton The dye having a coumarin skeleton is preferably a compound represented by the following formula (6-1) or a salt thereof.

In formula (6-1) above, A represents an optionally substituted coumarin skeleton, X represents a sulfo group or a carboxy group, and n represents an integer of 1-3.

The dye having a coumarin skeleton is more preferably represented by the following formula (6-2).

In formula (6-2) above, the group R represents a hydrocarbon group having 1 to 10 carbon atoms, Q represents a sulfur atom, an oxygen atom or a nitrogen atom, and n represents an integer of 1 to 3.

The above dye having a coumarin skeleton is particularly preferably represented by the following formula (6-3).

In formula (6-3) above, the group R represents a hydrocarbon group having 1 to 10 carbon atoms, and it is highly preferred that each of the two groups R is an ethyl group.

The salts of the compounds represented by formulas (1) to (6-3) above are salts formed with inorganic cations or organic cations. Inorganic cations include cations such as alkali metals, such as lithium, sodium, and potassium, as well as the ammonium ion (NH ₄ ⁺ ). Examples of organic cations include organic ammonium represented by the following formula (D).

In formula (D) above, Z ₁ to Z ₄ each independently represent a hydrogen atom, alkyl, hydroxyalkyl, or hydroxyalkoxyalkyl, and at least one of Z ₁ to Z ₄ is a group other than a hydrogen atom. .

Specific examples of Z ₁ to Z ₄ above include C ₁ -C ₆ alkyl, preferably C ₁ -C ₄ alkyl such as methyl, ethyl, butyl, pentyl and hexyl; hydroxymethyl, 2-hydroxyethyl, 3- Hydroxy C ₁ -C ₆ alkyl, preferably hydroxy C ₁ -C ₄ alkyl such as hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl and 2-hydroxybutyl; and hydroxyethoxymethyl, 2- Hydroxy C ₁ -C ₆ alkoxy C _{1 -C 6} alkyl, preferably hydroxy C ₁ -C ₄ alkoxy C ₁ -, such as hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 3-hydroxyethoxybutyl and 2-hydroxyethoxybutyl and _C4 alkyl.

Among the above inorganic cations and organic cations, more preferred are sodium ion, potassium ion, lithium ion, monoethanolammonium ion, diethanolammonium ion, triethanolammonium ion, monoisopropanolammonium ion, diisopropanolammonium ion, and triisopropanol. Examples include ammonium ions and cations such as ammonium. Among these, lithium ions, ammonium ions, and sodium ions are more preferred.

Other polarized light-emitting dyes that can be used in the polarized light-emitting device include, for example,
C. I. Fluorescent Brighter 5,
C. I. Fluorescent Brighter 8,
C. I. Fluorescent Brighter 12,
C. I. Fluorescent Brighter 28,
C. I. Fluorescent Brighter 30,
C. I. Fluorescent Brighter 33,
C. I. Fluorescent Brighter 350,
C. I. Fluorescent Brighter 360,
C. I. Fluorescent Brighter 365,
etc. These fluorescent dyes may be free acids or alkali metal salts (eg Na salts, K salts, Li salts), ammonium salts or salts of amines.

A polarized light-emitting device that emits polarized light can be obtained by aligning one or more of the above polarized light-emitting dyes in combination. In the case of using two or more polarized light-emitting dyes in the polarized light-emitting device, it is possible to adjust the light emission color to various colors by adjusting the mixing ratio of the polarized light-emitting dyes. For example, by adjusting the absolute values of the chromaticities a ^* and b ^* to be 5 or less, the polarized light emitted by the polarized light emitting element can be made white. The above chromaticity a ^* value and b ^* value are obtained according to JIS Z 8781-4: 2013, based on the spectral distribution measured for the light emitted from the polarized light emitting element when the light is incident on the polarized light emitting element. be done. The object color display method defined in JIS Z 8781-4:2013 corresponds to the object color display method defined by the International Commission on Illumination (abbreviated as “CIE”). The chromaticity a ^* value and b ^* value are usually measured by irradiating the measurement sample with natural light. and measuring the emitted light, the chromaticity a ^* value and b ^* value can be confirmed. The absolute value of a ^* of the emitted light is 5 or less, preferably 4 or less, more preferably 3 or less, still more preferably 2 or less, and particularly preferably 1 or less. The absolute value of b ^* of the emitted light is 5 or less, preferably 4 or less, more preferably 3 or less, still more preferably 2 or less, and particularly preferably 1 or less. If the absolute values of the a ^* value and the b ^* value are each independently 5 or less, it can be perceived as white by the human eye, and if both are 5 or less, it is perceived as more preferable white light emission. be able to. Since the emitted polarized light is white, it can be used as a natural light source such as sunlight, as a light source for paper white terminals, etc., and it has the advantage of being easy to apply even when placed in a display that uses a color filter. There is As for the emission intensity, there is no problem in applying it to a display if it can be perceived by the eye. In particular, it is important that the emitted light has a high degree of polarization and a high transmittance in the visible region as features of the present application.

(Other pigments)
The above-mentioned polarized light-emitting device contains one or a plurality of dyes or salts thereof having at least one skeleton selected from the group consisting of a stilbene skeleton, a biphenyl skeleton, and a coumarin skeleton in the molecule, and inhibits the polarized light-emitting function. If necessary, one or more other organic dyes or other fluorescent dyes may be further included for the purpose of color adjustment or the like. Other organic dyes are not particularly limited as long as they can produce the color (hue) of the polarized light-emitting element or the color of the emitted light, but those with high dichroism are preferred, and also have a stilbene skeleton, a biphenyl skeleton, and coumarin. A dye that has in its molecule at least any skeleton selected from the group consisting of a skeleton and has little effect on the polarization performance in the ultraviolet light region is preferred. Such other organic dyes include, for example, C.I. I. Direct. Yellow 12, C.I. I. Direct. Yellow 28, C.I. I. Direct. Yellow 44, C.I. I. Direct. Orange 26, C.I. I. Direct. Orange 39, C.I. I. Direct. Orange 71, C.I. I. Direct. Orange 107, C.I. I. Direct. Red2, C.I. I. Direct. Red31, C.I. I. Direct. Red79, C.I. I. Direct. Red81, C.I. I. Direct. Red 247, C.I. I. Direct. Blue 69, C.I. I. Direct. Blue 78, C.I. I. Direct. Green 80, and C.I. I. Direct. Green59 etc. are mentioned. These organic dyes may be free acids or alkali metal salts (eg Na salts, K salts, Li salts), ammonium salts or salts of amines. In addition, as the other fluorescent dyes, generally disclosed fluorescent dyes can also be used for the purpose of adjusting the emission color, and there is no particular limitation.

When other organic dyes or other fluorescent dyes are used in combination, it is possible to select the dyes to be blended and adjust the blending ratio and the like in order to adjust the desired color of the polarized light emitting device. Depending on the purpose of preparation, the mixing ratio of other organic dyes or other fluorescent dyes is not particularly limited, but the total amount of these other organic dyes or other fluorescent dyes is It is preferably used in the range of 0.01 to 10 parts by mass.

The dyeing solution may further contain a dyeing aid in addition to the dyes described above, if necessary. Dyeing assistants include, for example, sodium carbonate, sodium hydrogencarbonate, sodium chloride, sodium sulfate (mirabilite), anhydrous sodium sulfate and sodium tripolyphosphate, preferably sodium sulfate. The content of the dyeing aid can be arbitrarily adjusted depending on the dyeability of the dye used, the immersion time, the temperature of the dyeing solution, etc., but it is preferably 0.0001 to 10% by mass in the dyeing solution. It is more preferably 0.0001 to 2% by mass.

After the dyeing process, a pre-washing process may optionally be performed to remove the dyeing solution adhered to the surface of the substrate during the dyeing process. By going through the pre-washing step, it is possible to prevent the dye remaining on the surface of the substrate from migrating into the liquid to be treated next. In the pre-cleaning step, water is generally used as the cleaning liquid. As for the washing method, it is preferable to immerse the dyed base material in the washing solution, while the base material can be washed by applying the washing solution to the base material. Although the washing time is not particularly limited, it is preferably 1 to 300 seconds, more preferably 1 to 60 seconds. The temperature of the cleaning liquid in the pre-cleaning step must be a temperature at which the material constituting the base material does not dissolve, and the cleaning treatment is generally carried out at 5 to 40°C. Since performance of the polarized light-emitting element is not significantly affected even without the preliminary cleaning step, the preliminary cleaning step may be omitted.

(Crosslinking step)
After the dyeing step or the pre-washing step, the substrate may contain a cross-linking agent. The method of incorporating the cross-linking agent into the base material is preferably immersing the base material in a treatment solution containing the cross-linking agent, while the treatment solution may be applied or applied to the base material. As a cross-linking agent in the treatment solution, for example, a solution containing boric acid is used. The solvent in the treatment solution is not particularly limited, but water is preferred. The concentration of boric acid in the treatment solution is preferably 0.1 to 15% by mass, more preferably 0.1 to 10% by mass. The temperature of the treatment solution is preferably 30-80°C, more preferably 40-75°C. The processing time of this cross-linking step is preferably 30 seconds to 10 minutes, more preferably 1 to 6 minutes. By including this cross-linking step in the method for producing a polarized light-emitting element according to the present invention, the degree of polarization of the light emitted by the obtained polarizing element is high, and high contrast is exhibited as a display. This is an excellent effect that cannot be expected from the function of boric acid, which has been used in the prior art for the purpose of improving water resistance or light transmittance. Moreover, in the cross-linking step, if necessary, a fixing treatment may be further performed with an aqueous solution containing a cationic polymer compound. The fix treatment enables immobilization of the dye in the polarized light-emitting device. At this time, as the cationic polymer compound, for example, cation, dicyanamide and formalin polymerization condensate as dicyanide, dicyandiamide/diethylenetriamine polycondensate as polyamine, epichlorohydrin/dimethylamine addition polymer as polycation, dimethyl A diallylammonium chloride/dioxide ion copolymer, a diallylamine salt polymer, a dimethyldiallylammonium chloride polymer, an allylamine salt polymer, a dialkylaminoethyl acrylate quaternary salt polymer, and the like are used.

(Stretching process)
After passing through the said bridge|crosslinking process, an extending process is implemented. The stretching step is performed by uniaxially stretching the substrate in a given direction, and may be either a wet stretching method or a dry stretching method. The draw ratio is preferably 3 times or more, more preferably 5 to 8 times.

In the wet stretching method, the substrate is preferably stretched in water, a water-soluble organic solvent, or a mixed solution thereof. More preferably, the stretching treatment is performed while the substrate is immersed in a solution containing at least one cross-linking agent. As the cross-linking agent, for example, boric acid in the cross-linking agent step can be used, and preferably, the stretching treatment can be performed in the treatment solution used in the cross-linking step. The stretching temperature is preferably 40 to 70°C, more preferably 45 to 60°C. The stretching time is usually 30 seconds to 20 minutes, preferably 2 to 7 minutes. The wet stretching process may be carried out in one stage of stretching or may be carried out in two or more stages of multistage stretching. Optionally, the stretching treatment may be carried out before the dyeing step, in which case the orientation of the dyes can also be carried out at the time of dyeing.

In the above dry stretching method, when the heating medium for stretching is an air medium, the substrate is preferably stretched at a temperature of room temperature to 180°C. Also, the humidity is preferably in an atmosphere of 20 to 95% RH. Examples of the method for heating the substrate include roll-to-roll zone stretching, roll heating stretching, hot pressure stretching, infrared heating stretching, and the like, but are not limited to these stretching methods. The dry stretching process may be carried out in one stage of stretching or in multi-stage stretching of two or more stages.

(Washing process)
During the stretching step, the cross-linking agent may deposit or foreign matter may adhere to the surface of the substrate, so a washing step may be performed to wash the surface of the substrate. The washing time is preferably 1 second to 5 minutes. As for the cleaning method, the substrate is preferably immersed in the cleaning liquid, while the cleaning liquid may be applied or applied to the substrate for cleaning. Water is preferred as the cleaning liquid. The cleaning treatment may be performed in one step or in a multi-step treatment of two or more steps. The temperature of the washing solution in the washing step is not particularly limited, but is usually 5 to 50°C, preferably 10 to 40°C, and may be normal temperature.

Examples of solvents for the solutions or treatment liquids used in the above steps include, in addition to water, dimethyl sulfoxide, N-methylpyrrolidone, methanol, ethanol, propanol, isopropyl alcohol, glycerin, ethylene glycol, propylene glycol, diethylene glycol, alcohols such as triethylene glycol, tetraethylene glycol or trimethylolpropane; and amines such as ethylenediamine and diethylenetriamine. The solvent of the solution or treatment liquid is not limited to these, but is most preferably water. Moreover, the solvents for these solutions or treatment liquids may be used singly or as a mixture of two or more thereof.

(Drying process)
After the washing process, the substrate is dried. Drying treatment can be performed by natural drying, but in order to further increase the drying efficiency, it is possible to perform compression with a roll, removal of moisture from the surface with an air knife or water absorption roll, etc. In addition, air drying can be performed. It is also possible to The temperature of the drying treatment is preferably 20 to 100°C, more preferably 60 to 100°C. The drying time is preferably 30 seconds to 20 minutes, more preferably 5 to 10 minutes.

By the above method, the layer (B), which is a polarized light emitting element, can be produced, and by combining this with the layer (A), the optical control system of the present invention can be obtained. The layer (B) is an element that exhibits polarized light emission and also exhibits a polarizing function in the ultraviolet region, that is, an element that exhibits anisotropic absorption. In particular, a compound having at least one skeleton selected from the group consisting of the stilbene skeleton, biphenyl skeleton, and coumarin skeleton exemplified above in the molecule does not decompose even in a high-temperature or high-humidity heat environment, so it has high durability.

The optical control system receives irradiation of light in the non-visible light range such as the ultraviolet light range, absorbs the light in the ultraviolet light range, and uses the energy thereof to emit polarized light in the visible light range. Since the light emitted by the optical control system is polarized light in the visible light region, when the optical control system is observed through a general polarizing plate having a polarization function for light in the visible light region, the By changing the angle of the axis of a general polarizing plate having a polarizing function in the visible light region, polarized light can be visually recognized. That is, it becomes easy to distinguish between the light on the strong emission axis and the light on the axis that does not emit light (or the axis that emits extremely weak light). The degree of polarization of the polarized light emitted by the optical control system is at least 70%, preferably at least 80%, more preferably at least 90%, even more preferably at least 95%, particularly preferably at least 99%. Also, the optical control system preferably transmits light in the visible light range without absorbing it. If the transmittance of light in the visible light region of the optical control system is 60% or more in terms of the transmittance corrected for visual sensitivity, a liquid crystal display with significantly higher transmittance than the conventional liquid crystal display can be obtained. However, it is preferably 70% or more, more preferably 80% or more, still more preferably 85% or more, and particularly preferably 90% or more. Since the optical control system obtained in the present invention has a high degree of polarization, it not only has high transparency in the visible light region in the non-light-emitting state, but also emits strong light along the axis even in the light-emitting state. It is preferable because it absorbs uniaxial light when viewed through a common polarizing plate, so that an optical control system with high visual transparency can be obtained in an axis that does not emit light (or an axis that emits extremely weak light).

(polarized light emitting plate)
A polarizing light emitting plate with an optical control system is also included in this application. In addition to the above optical control system, the polarized light emitting plate can have a transparent protective layer and the like. The transparent protective layer is used to improve the water resistance, handleability, etc. of the optical control system, and does not affect the polarizing function exhibited by the optical control system.

The transparent protective layer is preferably a transparent protective layer having excellent optical transparency and mechanical strength. In addition, the transparent protective layer is preferably a film having a layer shape that can maintain the shape of the optical control system, and is a plastic film that is excellent in heat stability, moisture shielding properties, etc. in addition to transparency and mechanical strength. Preferably. Examples of materials for forming such a protective film include cellulose acetate films, acrylic films, fluorine films such as ethylene tetrafluoride/propylene hexafluoride copolymers, polyester resins, and polyolefin resins. Alternatively, a film made of a polyamide resin may be used, and preferably a triacetyl cellulose (TAC) film or a cycloolefin film is used. The thickness of the transparent protective layer is preferably in the range of 1 μm to 200 μm, more preferably in the range of 10 μm to 150 μm, particularly preferably in the range of 40 μm to 100 μm. The method for producing the polarized light-emitting plate is not particularly limited, but it can be produced, for example, by superimposing a transparent protective layer on the optical control system and laminating them according to a known recipe.

The polarized light-emitting plate may further include an adhesive layer between the transparent protective layer and the optical control system for bonding the transparent protective layer and the optical control system together. The adhesive constituting the adhesive layer is not particularly limited, but examples include polyvinyl alcohol-based adhesives, urethane emulsion-based adhesives, acrylic-based adhesives, polyester-isocyanate-based adhesives, etc., preferably A polyvinyl alcohol-based adhesive is used. After bonding the transparent protective layer and the polarized light-emitting element with an adhesive, the above polarized light-emitting plate can be produced by performing drying or heat treatment at an appropriate temperature.

In addition, the polarized light-emitting plate may appropriately include various known functional layers such as an antireflection layer, an antiglare layer, and a further transparent protective layer on the exposed surface of the transparent protective layer. When such layers having various functionalities are produced, a method of coating materials having various functionalities on the exposed surface of the transparent protective layer is preferable, and various functional layers or films are applied via an adhesive or a pressure-sensitive adhesive. It is also possible to laminate on the exposed surface of the transparent protective layer.

Examples of the additional transparent protective layer include a protective layer such as an acrylic-, urethane-, or polysiloxane-based hard coat layer. In addition, an antireflection layer may be provided on the exposed transparent protective layer in order to further improve the single transmittance. The antireflection layer can be formed, for example, by depositing or sputtering a substance such as silicon dioxide or titanium oxide on the transparent protective layer, or by thinly coating a fluorine-based substance on the transparent protective layer.

By the above method, it is possible to provide a preferable form of an optical control system or a polarized light emitting plate using the same.

In the present application, it is one of preferred embodiments that the above-described compound (a) in the layer (A) further has luminescence anisotropy. Since the layer (A) has emission anisotropy, it can emit only uniaxially polarized light, and the light in the emission axis coincides with the absorption emission axis of the layer (B), Light emitted by layer (A) can substantially provide light to layer (B) with high efficiency. The emission anisotropy can be expressed by having the absorption anisotropy of the layer (A), that is, the absorption anisotropy of the compound (a), like the layer (B). The absorption anisotropy is generally expressed as a dichroic ratio, and the degree of orientation of the compound (a) can be calculated from the dichroic ratio. The dichroic ratio is the ratio of the absorption amount of the axis with the strongest absorption and the absorption amount of the axis with the lowest absorption, and if the dichroic ratio is 2 or more, linearly polarized light can be emitted. Although not limited, about 70 has a sufficiently high dichroic ratio. The dichroic ratio is preferably 5 or more, preferably 10 or more, more preferably 20 or more, still more preferably 30 or more. The degree of orientation is a numerical value given by the above formula (I), and when it is 0.25 or more and 1.00 or less, it is possible to provide a more efficient polarized light emitting device or display device of the present application, but it is particularly preferable It is preferably 0.50 or more and 0.98 or less, more preferably 0.75 or more and 0.96 or less, and still more preferably 0.85 or more and 0.96 or less.

The optical control system or the polarizing light-emitting plate can be used not only as a single unit, but also as a display device such as a general display, especially a liquid crystal display. Furthermore, by using a general polarizing plate and the optical control system of the present application, polarization control by absorption and polarization control by light emission are possible, which is preferable.

The optical control system of the present application and the display device using it can be effectively used as a highly efficient polarized backlight for liquid crystal displays. It can be used for a see-through display capable of emitting light and a polarized light source having transparency. Furthermore, it can be utilized as an element, a light source, or a display device that can efficiently emit polarized light from ultraviolet light of 300 nm or more, which is natural light, as light in the visible region. That is, the optical control system of the present application and the display device using the same can efficiently emit polarized light particularly outdoors. Alternatively, by using the layer (A) as in the present application, it is possible to provide an optical control system having high light resistance and a display device using the same. In general, it is known that polymers and dyes are degraded by certain light such as ultraviolet rays. can be substantially suppressed, and the polarized light emitting element or the display device itself can be given high durability, and it can be suitably used for display devices that require particularly high light resistance, such as outdoor liquid crystal displays. An optical control system, or optical device, is provided.

EXAMPLES The present invention will be described in more detail below with reference to examples, but these are examples and do not limit the present invention in any way. Also, "%" and "parts" described below are based on mass unless otherwise specified. In each structural formula of the compounds used in each example and comparative example, an acidic functional group such as a sulfo group is described in the form of a free acid.

[Example 1]
(Synthesis example 1)
35.2 parts of commercially available 4-amino-4'-nitrostilbene-2,2'-disulfonic acid was added to 300 parts of water and stirred, and adjusted to pH 0.5 using 35% hydrochloric acid. 10.9 parts of a 40% aqueous sodium nitrite solution was added to the resulting solution, and the mixture was stirred at 10°C for 1 hour. After adjusting to pH 4.0, the mixture was stirred for 4 hours. 60 parts of sodium chloride was added to the resulting reaction solution, and the precipitated solid was separated by filtration, washed with 100 parts of acetone, and dried to obtain 62.3 parts of the compound represented by the following formula (7).

62.3 parts of the formula (7) obtained above was added to 300 parts of water and stirred, and the pH was adjusted to 10.0 using a 25% aqueous sodium hydroxide solution. 20 parts of 28% aqueous ammonia and 9.0 parts of copper sulfate pentahydrate were added to the obtained solution, and the mixture was stirred at 90° C. for 2 hours. 25 parts of sodium chloride was added to the obtained reaction liquid, and the precipitated solid was separated by filtration and washed with 100 parts of acetone to obtain 40.0 parts of a wet cake of the compound of the following formula (8). By drying the wet cake with a hot air dryer at 80° C., 20.0 parts of the compound (λmax: 376 nm) of the following formula (8) was obtained.

(Preparation of layer (B))
A 75 μm-thick polyvinyl alcohol film (VF-PS#7500 manufactured by Kuraray Co., Ltd.) was immersed in hot water at 40° C. for 3 minutes to swell the film. The film obtained by swelling the compound (b) described in Compound Example 5-1, 4,4'-bis-(sulfostyryl)biphenyl disodium aqueous solution (Tinopal NFW Liquid manufactured by BASF) 1.0 parts by weight , 0.3 parts by weight of compound (8) obtained in Synthesis Example 1, 1.0 parts by weight of Glauber's salt, and 1500 parts by weight of water at 45° C. for 4 minutes. The resulting film was stretched in an aqueous 3% boric acid solution at 50° C. for 5 minutes so as to be 5 times as long. The film obtained by stretching was washed with water at room temperature for 20 seconds while maintaining the stretched state, and then dried to obtain a polarized light-emitting element A serving as the layer (B) of the present application. The maximum absorption wavelength of the layer (B) was 377 nm, the Order Parameter calculated from the above formula (I) for the maximum absorption wavelength was 0.91, and the absorption band was 350 nm to 410 nm. . It was also found that the obtained layer (B) emits linearly polarized light having a maximum emission wavelength of 465 nm.

(Preparation of optical control system using layer (A) and layer (B))
A triacetyl cellulose film containing no ultraviolet absorber (ZRD-60 manufactured by Fuji Film Co., Ltd.) was treated with a 1.5 N sodium hydroxide aqueous solution at 35°C for 10 minutes, washed with water, and then dried at 70°C for 10 minutes. let me A triacetyl cellulose film obtained by alkali treatment is applied to both sides of the layer (B) obtained above. ) as 2-(2-pyridylamino)ethylamine dihydrochloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 0.5 parts by weight. An optical control system was obtained using layers (A) and (B) whose emission band lies at 380 nm±30 nm, with the highest derived absorption at 300 nm and highest wavelength emission at 380 nm. When the obtained optical control system was irradiated with ultraviolet rays using a 375 nm hand-held type black light (manufactured by Nichia Corporation "PW-UV943H-04"), it emitted white light and further passed through a polarizing plate. When the luminescence was confirmed, it was confirmed that white polarized luminescence was observed in the stretching axis direction during processing of the layer (B), while no polarized luminescence was observed in the non-stretching axis. That is, the layer (B) was a layer emitting linearly polarized light. The obtained optical control system was attached to glass to obtain a measurement sample.

[Example 2]
50 parts by weight of PET-30 manufactured by Nippon Kayaku Co., Ltd., 9,10-phenanthrenequinone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) corresponding to the compound (a) of the present application ) 0.5 parts by weight, 5 parts by weight of Irgacure-184, and 55 parts by weight of 2-butanone are coated so that the coating film thickness after drying for 3 minutes at 60 ° C. is 8 μm. Then, a layer (A) containing the compound (a) is formed by irradiating with ultraviolet light from a high-pressure mercury lamp (accumulated light amount 400 mJ/cm ² ), and a film (PAC-3-60T manufactured by San A Kaken Co., Ltd.) is formed on the layer. and treated with a 1.5N sodium hydroxide aqueous solution at 35° C. for 10 minutes while protecting the UV-polymerized resin composition coating layer, washed with water, and then dried at 70° C. for 10 minutes. Two triacetyl cellulose films having the obtained layer (A) were used, and the surfaces not having the layer (A) were coated with 100 parts by weight of water and a polyvinyl alcohol resin (Japan Vippoval NH-26) (manufactured by Co., Ltd.) was laminated with an aqueous solution of 4 parts by weight, dried at 70°C for 10 minutes, and the film protecting the surface was peeled off. Layer (A)/triacetylcellulose film/polarized light-emitting element A/triacetylcellulose film/layer (A) having a layer (A) with an emission at the highest wavelength of 365 nm and an emission band of 365 nm±30 nm ) was obtained. When the optical control system was irradiated with ultraviolet rays using a 375 nm hand light type black light ("PW-UV943H-04" manufactured by Nichia Corporation), white light was emitted, and the light emission was confirmed through a polarizing plate. As a result, it was confirmed that white polarized light was emitted in the direction along which the layer (B) was stretched, while polarized light was not emitted in the direction along which the layer (B) was not stretched. A glass plate was bonded to one layer (A) of the obtained optical control system to obtain a measurement sample.

[Example 3]
A triacetyl cellulose film (ZRD-60 manufactured by Fuji Film Co., Ltd.) containing no ultraviolet absorber was added to the polarized light emitting element A, which is the layer (B) prepared in Example 1, with a 1.5 N sodium hydroxide aqueous solution, and C. for 10 minutes, washed with water, dried at 70.degree. C. for 10 minutes, and treated with an alkali. An aqueous solution containing 4 parts by weight of an alcohol resin (NH-26, manufactured by Nihon Acetate Bipoval Co., Ltd.) is laminated and dried at 70° C. for 10 minutes to form a triacetyl cellulose film/polarized light emitting element A/triacetyl cellulose film. A polarized luminescent plate was obtained. On one triacetyl cellulose film surface, 100 parts by weight of PTR-3000 (solid content 23 wt%) manufactured by Nippon Kayaku Co., Ltd., which is an adhesive, and 9,10-phenanthrenequinone (Fujifilm Wako Pure Chemical Industries, Ltd.) as compound (a) Co., Ltd.) was added to 2 parts by weight per 100 parts of the resin solid content of PTR-3000. An optical control system was obtained provided with a layer (A) having an absorption at 310 nm and an emission at the highest wavelength at 365 nm, whose emission band was 365 nm±30 nm. Next, a glass plate is attached to the "layer (A)" having the adhesive function of the obtained optical control system, triacetyl cellulose film/polarized light emitting element A/triacetyl cellulose film/adhesive layer (layer ( A))/glass was used as a measurement sample.

[Example 4]
In the measurement sample prepared in Example 3, 100 parts by weight of PTR-3000 manufactured by Nippon Kayaku Co., Ltd. (solid content: 23 wt%), which is an adhesive, and a compound ( As a), a composition consisting of 2 parts by weight of 9,10-phenanthrenequinone (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was provided with a layer having a solid content thickness of 25 μm, and the triacetyl cellulose film used in Example 1 ( ZRD-60 manufactured by Fuji Film Co., Ltd.) was laminated to prepare a measurement sample of an optical control system having layers (A) on both sides of layers (B).

[Example 5]
A triacetyl cellulose film (ZRD-60 manufactured by Fuji Film Co., Ltd.) containing no ultraviolet absorber was added to the polarized light emitting element A, which is the layer (B) prepared in Example 1, with a 1.5 N sodium hydroxide aqueous solution, and C. for 10 minutes, washed with water, dried at 70.degree. C. for 10 minutes, and treated with an alkali. An aqueous solution containing 4 parts by weight of an alcohol resin (NH-26, manufactured by Nihon Acetate Bipoval Co., Ltd.) is laminated and dried at 70° C. for 10 minutes to form a triacetyl cellulose film/polarized light emitting element A/triacetyl cellulose film. A polarized luminescent plate was obtained. On one triacetyl cellulose film surface, 100 parts by weight of PTR-3000 (solid content: 23 wt%) manufactured by Nippon Kayaku Co., Ltd., which is an adhesive, and 2,5-Bis (5-tert-butyl-2) as compound (a) -benzoxazolyl)-thiophene (manufactured by Chori Co., Ltd.) is coated on one side with a composition of 2 parts by weight per 100 parts of the resin solid content of PTR-3000 so that the solid content film thickness is 25 μm, and the compound (a ) was formed on the layer (B) as the layer (A) containing the adhesive layer. An optical control system was obtained with a layer (A) having a highest absorption at 340 nm and a highest wavelength emission at 445 nm from compound (a) and an emission band between 400 and 530 nm. Next, the obtained layer (A) of the optical control system and the glass plate are laminated to form a structure of triacetyl cellulose film/polarized light emitting element A/triacetyl cellulose film/adhesive layer (layer (A))/glass. An optical control system was obtained.

[Example 6]
(Synthesis example 2)
3.3 parts of commercially available 3-(2-benzimidazolyl)-7-(diethylamino)coumarin was added to a mixed solution of 45 parts of 98% sulfuric acid and 10 parts of 30% fuming sulfuric acid, and the mixture was stirred at 25° C. for 24 hours. The obtained reaction liquid was added to 300 parts of water, and the precipitated solid was separated by filtration and washed with 100 parts of acetone to obtain 10.0 parts of wet cake. This wet cake was dried with a hot air dryer at 80° C. to synthesize 3.0 parts of a water-soluble coumarin dichroic dye corresponding to the present compound (b) represented by the following formula (9).

(Preparation of Polarized Light Emitting Element B)
A 75 μm-thick polyvinyl alcohol film (VF-PS#7500 manufactured by Kuraray Co., Ltd.) was immersed in hot water at 40° C. for 3 minutes to swell the film. The film obtained by swelling was treated as compound (b) with 45 parts containing 0.7 parts by weight of the compound of formula (9) obtained in Synthesis Example 2, 1.0 parts by weight of Glauber's salt, and 1500 parts by weight of water. ℃ aqueous solution for 4 minutes to contain. The obtained film was stretched 5 times at 50° C. for 5 minutes in an aqueous 3% boric acid solution. The film obtained by stretching was washed with water at room temperature for 20 seconds while being kept in a tensioned state, and then dried to obtain a polarized light-emitting device B. In the order parameter calculated from the above formula (I) of the polarized light emitting element B, the order parameter at 450 nm based on the compound (b), formula (9), was 0.54. Further, the maximum light absorption wavelength based on the compound (b) of formula (9) is 450 nm, the light absorption band is 360 to 500 nm, and the highest wavelength emission, that is, the maximum emission wavelength is 512 nm. It had the property of emitting linearly polarized light.

A triacetyl cellulose film (ZRD-60 manufactured by Fuji Film Co., Ltd.) containing no ultraviolet absorber was applied to the prepared layer (B), the polarized light emitting element B, in a 1.5N sodium hydroxide aqueous solution at 35°C for 10 minutes. 100 parts by weight of water, polyvinyl alcohol resin (Japanese An aqueous solution containing 4 parts by weight of NH-26 (Vipoval Acetate Co., Ltd.) was used for lamination, followed by drying at 70° C. for 10 minutes to obtain a polarized light-emitting plate having a structure of triacetyl cellulose film/polarized light-emitting element B/triacetyl cellulose film. Obtained. On one side of the triacetyl cellulose film surface, 100 parts by weight of PTR-3000 (solid content 23 wt%) manufactured by Nippon Kayaku Co., Ltd., which is an adhesive, and 2,5-Bis (5-tert-butyl- A composition comprising 2 parts by weight of 2-benzoxazolyl)-thiophene (manufactured by Chori Co., Ltd.) per 100 parts of the resin solid content of PTR-3000 was coated on one side so that the solid content film thickness was 25 μm, and the compound ( An optical control system was obtained provided with a layer (A) having a highest absorption at 340 nm and a highest wavelength emission at 445 nm from a) and whose emission band was between 400 and 530 nm. Next, a glass plate is attached to the adhesive layer, which is the layer (A) of the optical control system thus obtained, and triacetyl cellulose film/polarized light emitting element B/triacetyl cellulose film/adhesive layer (layer (A))/glass. An optical control system with the configuration of

[Example 7]
(Synthesis Example 3)
35.2 parts of commercially available 4-diamino-stilbene-2,2'-disulfonic acid was added to 300 parts of water and stirred, and 35 parts of 4-methoxy-benzoyl chloride was gradually added over about 1 hour. The mixture was stirred at 60° C. for 1 hour to react. After completion of the reaction, the reaction mixture was allowed to cool to room temperature, and the solid content was filtered and dried at 70°C to obtain 44.5 parts of the compound (a) of the present application represented by the following formula (10).

(Preparation of layer (A))
A 75 μm-thick polyvinyl alcohol film (VF-PS#7500 manufactured by Kuraray Co., Ltd.) was immersed in hot water at 40° C. for 3 minutes to swell the film. The film obtained by swelling was treated as compound (a) with 45 containing 0.2 parts by weight of the compound of formula (10) obtained in Synthesis Example 3, 1.0 parts by weight of Glauber's salt, and 1500 parts by weight of water. ℃ aqueous solution for 4 minutes to contain. The obtained film was stretched 5 times at 50° C. for 5 minutes in an aqueous 3% boric acid solution. The film obtained by stretching is washed with water at room temperature for 20 seconds while maintaining tension, and then dried.
It was washed with water at room temperature for 20 seconds and dried at 70°C to obtain layer (A). Further, the maximum absorption wavelength based on the formula (10), which is the compound (a) contained in the layer (A), is 340 nm, and the Order Parameter calculated from the above formula (I) is 0.85, It had the characteristic of emitting light with the highest wavelength, that is, polarized light with a maximum emission wavelength of 445 nm and an emission band of 400 to 495 nm.

For the prepared layer (A), a triacetyl cellulose film (ZRD-60 manufactured by Fuji Film Co., Ltd.) containing no ultraviolet absorber was treated with a 1.5N sodium hydroxide aqueous solution at 35° C. for 10 minutes, washed with water, Then, on one side of the triacetyl cellulose film obtained by drying at 70 ° C. for 10 minutes and alkali treatment, and the layer (A) containing the formula (10) obtained above, 100 parts by weight of water, polyvinyl alcohol resin ( NH-26 (manufactured by Nippon Acetic Acid-Poval Co., Ltd.) was laminated via an aqueous solution containing 4 parts by weight, and the triacetyl cellulose film/polarized light emitting element B/triacetyl cellulose film were laminated together with the stretching axis of the polarized light emitting element B. Laminated so that the stretching axis of the polyvinyl alcohol film forming (A) coincides, triacetyl cellulose film/polarized light emitting element B/triacetyl cellulose film/layer (A) containing formula (10)/triacetyl An optical control system of the present application was obtained, which consisted of a cellulose film.

[Comparative Example 1]
A polarized light-emitting plate was prepared in the same manner as in Example 1, except that a triacetyl cellulose film (ZRD-60 manufactured by Fuji Film Co., Ltd.) was used, and the polarized light-emitting element A, which is the layer (B), was made of an adhesive made only of polyvinyl alcohol resin. , a measurement sample was prepared by laminating the layer (B) and a glass plate.

[Comparative Example 2]
Measurement without layer (A) was performed in the same manner as in Example 6, except that 2,5-Bis(5-tert-butyl-2-benzoxazolyl)-thiophene (manufactured by Chori Co., Ltd.) was not used as compound (a). A sample was made.

Each measurement sample obtained was evaluated as follows.

[evaluation]
(h-1) single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc
Single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc of each measurement sample were measured using a spectrophotometer ("U-4100" manufactured by Hitachi, Ltd.). Here, the single transmittance Ts is the transmittance of each wavelength when a single measurement sample is measured. The parallel transmittance Tp is the spectral transmittance at each wavelength measured by superimposing two measurement samples so that their absorption axis directions are parallel. The orthogonal transmittance Tc is a spectral transmittance measured by superimposing two measurement samples so that their absorption axes are orthogonal to each other. Measurements were made over a wavelength range of 220-780 nm.

(h-2) Degree of polarization ρ
The polarization degree ρ of each measurement sample was obtained by substituting the parallel transmittance Tp and the orthogonal transmittance Tc into the following formula (II).

(Formula 2)
ρ = {(Tp−Tc)/(Tp+Tc)} ^1/2 × 100 Formula (II)

(h-3) Single transmittance Ys corrected for luminosity and degree of polarization ρy corrected for luminosity
The single transmittance Ys (%) of each measurement sample is obtained in the wavelength region of 400 to 700 nm in the visible region, and the single transmittance Ts (%) obtained at predetermined wavelength intervals dλ (here, 5 nm) is calculated according to JIS Z 8722. : is the transmittance corrected for luminosity according to 2009. Specifically, it was calculated by substituting the single transmittance Ts (%) into the formula (V). In the following formula (V), Pλ represents the spectral distribution of the standard light (C light source), and yλ represents the 2-degree visual field color matching function. The luminosity-corrected degree of polarization ρy (%) in each sample was the value obtained by calculating with the instrument when measuring with U-4100.

(Formula 3)

375 nm single transmittance (Ts 375 (%)), 375 nm polarization degree (ρ 375 (%)), and luminosity correction for each of the measurement samples obtained in Examples 1 to 7 and Comparative Examples 1 and 2 Table 1 shows the calculated transmittance (Ys (%)) and the degree of polarization (ρy (%)) corrected for visibility. The polarizing function in the ultraviolet region and the visible region in each of the obtained measurement samples can be seen.

[Table 1]

As shown in Table 1, it can be seen that the optical control systems shown in Examples 1 to 7 have a higher transmittance than the luminosity correction single transmittance (Ys). In addition, from the single transmittance (Ts 375) and the degree of polarization (ρ 375) at 375 nm, the compound of the present application has a transmittance of 37 to 56% for the irradiated light while having the function of converting light into polarized light at 375 nm. Therefore, it can be seen that the results show that at least light of 375 nm, which is in the ultraviolet region, is absorbed. On the other hand, it can be seen that Comparative Examples 1 and 2 also have the same luminous efficiency correction single transmittance (Ys) as the optical control systems of Examples 1 to 7.

(h-4) Measurement of polarization of emitted light As a light source, an ultraviolet LED (M340L4 manufactured by THORLABOS) that has the strongest output at 348 nm and emits light in the range of 335 to 380 nm is used. A cut filter (“IUV-340” manufactured by Isuzu Seiko Glass Co., Ltd.) was installed to cut visible light. Then, a measurement sample obtained in each example or comparative example, a polarizing plate (“SKN-18043P” manufactured by Polatechno Co., Ltd., thickness 180 μm, Ys: 43%) having polarization in the visible region and ultraviolet were placed in order. , polarized luminescence emitted by the measurement sample was measured using a spectral irradiance meter (“USR-40” manufactured by Ushio Inc.). That is, the light from the light source passed through an ultraviolet transmission/visible cut filter, a measurement sample, and a polarizing plate having polarization in the visible region and ultraviolet in this order, and was arranged so as to be incident on the spectral irradiance meter. At that time, the spectral luminescence amount of each wavelength was superimposed so that the axis where the luminescence of the measurement sample was maximum and the absorption axis direction of the ultraviolet/visible polarizing plate were parallel, and the spectral luminescence amount was measured as Lw (weak luminescence axis). Spectroscopic luminescence of each wavelength measured by superimposing so that the axis that maximizes the light emission of the sample and the absorption axis direction of a polarizing plate (“SKN-18043P” manufactured by Polatechno Co., Ltd.) having polarization in the visible and ultraviolet regions are orthogonal. Lw and Ls were measured, with the amount being Ls (strong emission axis). By checking the energy amount of light emitted in the visible region when the absorption axes of the measurement sample and the general polarizing plate are parallel and orthogonal, the polarized light emission in the visible region of 400 nm to 700 nm can be obtained. We evaluated the light that was used.

Table 2 shows Ls and Lw at wavelengths of 460 nm, 550 nm, 610 nm and 670 nm of the measurement samples obtained in Examples 1-7 and Comparative Examples 1-2.

[Table 2]

As shown in Table 2, at 460 nm, 550 nm and 610 nm, Examples 1 to 5 have higher Ls than Comparative Example 1, and Examples 6 to 7 have higher Ls than Comparative Example 2. It can be seen that the emission luminance is increased and the visibility is improved. In particular, in Example 4, the emission luminance is higher than in Examples 1-3. Moreover, Ls at 460 nm is greatly increased in Examples 6 and 7 as compared with the comparative example. Furthermore, in any of the examples, the values of Ls/Lw at all measured wavelengths were equal to or higher than those of the comparative example, indicating high polarization contrast. From the above, the optical control system of the present application and the polarizing plate can increase the luminance of emitted light and also increase the contrast of the obtained polarized light.

Based on the above, the optical control system and the polarizing plate of the present application can exhibit a high polarizing action in the emission wavelength and a high Durability can be imparted. According to the present invention, natural light can be efficiently used for light emission. In addition, it is possible to efficiently emit polarized light in the visible region by using the light that has not been absorbed by dyes to emit polarized light with high efficiency, and to achieve high transmittance in the visible region. It is possible to provide an optical control system that has a high emission brightness while having a high brightness. Further, it is generally known that polymers and dyes are degraded by certain light such as ultraviolet light. A polarized light-emitting element that substantially suppresses the energy generated by the light source, can impart high durability to the element itself, and can be suitably used for display devices that require particularly high light resistance, such as liquid crystal displays. Or to provide an optical device. In addition, since a film that is transparent and emits polarized light when exposed to ultraviolet light can be obtained, the present invention can be applied to various advantages such as security and design.

Claims (9)

A layer (A) that absorbs light in the near-ultraviolet to near-ultraviolet visible region and emits light using the absorbed light; ) is used to emit polarized light having a wavelength in the visible range, and a layer (B) that emits polarized light,
An optical control system in which the layer (A) is laminated on both sides of the layer (B) . The optical control according to claim 1, wherein the layer (A) contains a compound (a) that absorbs light in a wavelength range of at least 300 to 360 nm and emits light having an emission wavelength in a wavelength range of at least 350 to 430 nm. system. 3. The layer (B) according to claim 1 or 2, wherein the layer (B) contains a compound (b) that absorbs light in the wavelength range of at least 350 to 430 nm and emits light having an emission wavelength in the wavelength range of at least 400 to 700 nm. Optical control system. 4. The optical control system according to any one of claims 1 to 3, wherein the light emitted by the layer (B) is linearly polarized light. 4. The optical control system according to claim 3 , wherein the compound (b) is a compound having absorption anisotropy. 3. The optical control system according to claim 2 , wherein the compound (a) is a compound having emission anisotropy. 6. The optical control system according to claim 3, wherein the compound (b) has at least one skeleton selected from the group consisting of a stilbene skeleton, a biphenyl skeleton and a coumarin skeleton in its molecule. A polarized light-emitting plate comprising an optical control system according to any one of claims 1-7 . A display device comprising the optical control system according to any one of claims 1 to 7 or the polarized light emitting plate according to claim 8 .