CN113924289A

CN113924289A - Luminescent compound or salt thereof, and polarized light-emitting element, polarized light-emitting panel, and display device each containing the same

Info

Publication number: CN113924289A
Application number: CN202080041784.6A
Authority: CN
Inventors: 中村光则; 森田陵太郎; 望月典明
Original assignee: Nippon Kayaku Co Ltd
Current assignee: Nippon Kayaku Co Ltd
Priority date: 2019-07-12
Filing date: 2020-07-10
Publication date: 2022-01-11
Also published as: WO2021010337A1; TW202111086A; JPWO2021010337A1; JP7556856B2; TWI825331B

Abstract

A luminescent compound represented by the following formula (1) or a salt thereof.

Description

Luminescent compound or salt thereof, and polarized light-emitting element, polarized light-emitting panel, and display device each containing the same

Technical Field

The present invention relates to a novel light-emitting compound or a salt thereof, and a polarized light-emitting element, a polarized light-emitting panel, and a display device (display) each containing the compound.

Background

A polarizing plate having a light transmission and/or shielding function is a basic component of a Display device such as a Liquid Crystal Display (LCD) together with a Liquid Crystal having a light switching function. The application fields of the LCD are expanding from small-sized devices such as initial computers and watches to notebook computers, document processors, liquid crystal projectors, liquid crystal televisions, car navigation systems, and indoor and outdoor measuring devices. Further, the present invention is also applicable to lenses having a polarizing function, for example, sunglasses for improving visibility, and polarizing glasses for 3D televisions in recent years. As described above, polarizing plates are widely used, and their use environment is also expanded from low temperature to high temperature, low humidity to high humidity, low light amount to high light amount, and the like, and thus polarizing plates having high polarizing performance and high durability are required.

In general, a polarizing film constituting a polarizing plate is produced by stretching and aligning a film of polyvinyl alcohol or a derivative thereof containing iodine or a dichroic dye, or is produced by forming a polyene by dehydrochlorination of a polyvinyl chloride film or dehydration of a polyvinyl alcohol film and aligning the polyene. Since the polarizing plate formed of such a conventional polarizing film includes a dichroic dye having absorption in the visible light region, transmittance is reduced. For example, the transmittance of a general polarizing plate commercially available is 35 to 45%.

As a technique for imparting a polarizing function while maintaining a transmittance at a certain level in the visible light region, patent document 1 describes a technique of a polarizing plate for ultraviolet rays, which is a problem of a conventional polarizing plate in which the transmittance in the visible light region is reduced. However, this technique uses a yellow dye having absorption in the visible light region, and therefore has insufficient transmittance and is observed to have deep yellow coloration.

When a polarizing plate having a low transmittance in the visible light region is used for a display or the like, the transmittance of the entire display is reduced, and thus a method of obtaining polarization without using a conventional polarizing plate has been studied. As such a method, patent documents 2 to 4 describe a polarized light emitting device.

However, the polarized light emitting devices described in patent documents 2 to 4 contain special metals, such as rare and expensive metals including lanthanides and europium, and therefore, the cost is high, and the manufacturing is very difficult, which is not suitable for mass production. In addition, these polarized light emitting elements are difficult to use in displays because of weak polarized light emission, and linearly polarized light emission cannot be obtained. Therefore, development of a novel polarizing light-emitting panel which exhibits a polarizing light-emitting action, has high transparency in the visible light region, and can be used for a liquid crystal display or the like which requires durability under severe environments, and a material for forming the polarizing light-emitting panel have been demanded.

[ Prior art documents ]

[ patent document ]

Patent document 1: WO2005/015275

Patent document 2: japanese laid-open patent publication No. 2008-224854

Patent document 3: japanese patent laid-open publication No. 2013-121921

Patent document 4: WO 2011/111607.

Disclosure of Invention

[ problem to be solved by the invention ]

The purpose of the present application is to provide a novel light-emitting compound, and a polarized light-emitting element, a polarized light-emitting panel, and a display device each containing the compound.

[ means for solving the problems ]

The present inventors have intensively studied to achieve the object, and as a result, have found that a polarized light emitting element and a polarized light emitting panel containing a compound having a specific structure or a salt thereof have a high dichroic ratio in an ultraviolet region, exhibit a high transmittance in a visible light region, and exhibit excellent durability in a severe environment. Further, the compound having such a specific structure or a salt thereof exhibits an effect of emitting polarization in the visible light region by irradiating light in the ultraviolet light region to the near ultraviolet visible light region, for example, light of 300 to 430nm, and the present invention has been completed.

That is, the present invention relates to the following, but is not limited thereto.

[ invention 1]

(in the formula (1), at least one of X and Y (which may be independent of each other) is selected from the group consisting of a nitro group, an amino group which may have a substituent, an amide group which may have a substituent, an alkyl group having from C1 to 4 which may have a substituent, an alkoxy group having from C1 to 4 which may have a substituent, an aromatic group which may have a substituent, and a heterocyclic group which may have a substituent, and when X or Y is not the above-mentioned selected group, X or Y is selected from arbitrary substituents, M each independently represents a hydrogen atom, a metal ion, or an ammonium ion, M each independently represents an integer of from 0 to 2, and s is 0 or 1).

[ invention 2]

The light-emitting compound according to invention 1, wherein at least one of X and Y in the above formula (1) (both of which are independent of each other) is selected from the group consisting of substituents represented by the following formulae (2) to (8), or a salt thereof.

(in the above formula (2), R represents a hydrogen atom, a C1-4 alkyl group, a C1-4 alkyl group having a sulfo group, or a substituent selected from those represented by the formulae (3) to (7)A substituent group represented by the following formulae (3) and (4), wherein A is independently selected from the group consisting of a hydrogen atom, a halogen group, a nitro group, a hydroxyl group, an alkyl group having C1 to 4, an alkoxy group having C1 to 4, an alkyl group having C1 to 4 having a sulfo group, an alkyl group having C1 to 4 having a hydroxyl group, an alkyl group having C1 to 4 having a carboxyl group, an alkoxy group having C1 to 4 having a sulfo group, an alkoxy group having C1 to 4 having a hydroxyl group, and an alkoxy group having C1 to 4 having a carboxyl group, and q is a substituent group represented by the following formulae (3) and (4), and q is a substituent group represented by the following formula¹Represents an integer of 0 to 4, M in the above formulae (3) to (7) is as defined above for formula (1), and n in the above formulae (3) and (4)¹N in the above formulae (5) to (7)²Each independently represents an integer of 0 to 3, t in the formula (8) is 0 or 1, Z represents a group selected from the group consisting of an amino group which may have a substituent, a phenyl group which may have a substituent, a naphthyl group which may have a substituent, a benzoyl group which may have a substituent, a heterocyclic group which may have a substituent, and a stilbene group which may have a substituent, and each represents a bonding position of X or Y in the formula (1).

[ invention 3]

The light-emitting compound according to claim 1 or 2, wherein X and Y in the above formula (1) are each independently a nitro group, an amino group which may have a substituent, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aromatic group which may have a substituent, a heterocyclic group which may have a substituent, or a group selected from the group of substituents represented by the formulae (2) to (8), or a salt thereof.

[ invention 4]

The light-emitting compound or a salt thereof according to claim 1 or 2, wherein X and Y in the formula (1) are each independently selected from the group consisting of substituents represented by formulae (2) to (8), and when at least any one of X and Y is represented by formula (8), Z in formula (8) is any one selected from the group consisting of substituents represented by formulae (2) to (7) (wherein X represents a bonding position of Z in formula (8)).

[ invention 5]

The light-emitting compound according to invention 1 or 2, wherein one of X and Y in the above formula (1) is a nitro group or an amino group which may have a substituent, the other is selected from the group consisting of substituents represented by formulae (2) to (8), and when a substituent represented by formula (8) is selected, Z in formula (8) is selected from the group consisting of substituents represented by formulae (2) to (7), or a salt thereof.

[ invention 6]

The light-emitting compound according to claim 1 or 2, wherein any one of X and Y in the formula (1) is a nitro group or an amino group which may have a substituent, and any one of X and Y is a substituent represented by the formula (8), and Z in the formula (8) is a nitro group or an amino group which may have a substituent, or a salt thereof.

[ invention 7]

The light-emitting compound according to claim 1 or 2, wherein X and Y in the above formula (1) are both a nitro group or an amino group which may have a substituent, or a salt thereof.

[ invention 8]

The light-emitting compound according to invention 1 or 2, wherein X and Y in the above formula (1) are both selected from the group consisting of substituents represented by formulae (2) to (8), and when a substituent represented by formula (8) is selected, Z in the formula (8) is selected from the group consisting of substituents represented by formulae (2) to (7), or a salt thereof.

[ invention 9]

The light-emitting compound or a salt thereof according to any one of inventions 1 to 8, wherein s is 0.

[ invention 10]

A light-emitting compound according to any one of claims 1 to 8, or a salt thereof, wherein s is 1.

[ invention 11]

A polarized light-emitting element having a polarized light-emitting function and comprising the light-emitting compound according to any one of claims 1 to 10 or a salt thereof.

[ invention 12]

The polarized light emitting element according to invention 11, further comprising 1 or more kinds of organic dyes or fluorescent dyes other than the above luminescent compound or a salt thereof.

[ invention 13]

The polarized light emitting device according to invention 11 or 12, further comprising a substrate.

[ invention 14]

The polarized light emitting device according to invention 13, wherein the substrate is a film containing a polyvinyl alcohol resin or a derivative thereof.

[ invention 15]

A polarized light emitting panel comprising a transparent protective film on at least one surface of the polarized light emitting element according to any one of inventions 11 to 14.

[ invention 16]

A display device comprising the polarized light emitting element according to any one of claims 11 to 14 or the polarized light emitting panel according to claim 15.

[ efficacy of the invention ]

The light-emitting compound or a salt thereof having a specific structure of the present invention absorbs light in the ultraviolet to visible light region, for example, light in the ultraviolet to near ultraviolet visible light region, specifically, light of 300 to 430nm, and exhibits polarized light emission in the visible light region by utilizing its energy. Further, a polarizing element and a polarizing plate produced using the luminescent compound or a salt thereof are a novel polarized light emitting element and a polarized light emitting panel that exhibit polarized light emitting action. In one embodiment, the light-emitting compound or a salt thereof of the present invention, and a polarized light-emitting element and a polarized light-emitting panel containing the compound exhibit high polarization degree at absorption wavelengths. Therefore, by using the compound represented by the formula (1) or a salt thereof, a novel polarized light emitting element and a polarized light emitting panel which have a high degree of polarization in an absorption wavelength and exhibit polarized light emitting action can be provided without using a rare and expensive lanthanoid metal or the like. In one embodiment, the polarized light emitting element and the polarized light emitting panel of the present invention exhibit high transmittance in the visible light region. In one embodiment, the polarized light emitting element and the polarized light emitting panel of the present invention exhibit excellent durability against heat, humidity, and the like. Therefore, the polarized light emitting element and the polarized light emitting panel can be applied to display devices such as liquid crystal displays, which require high transmittance in the visible light region and high durability in severe environments.

Detailed Description

In the present description and claims, a "substituent" conveniently comprises a hydrogen atom. "optionally substituted" means that the compound has no substituent. For example, "phenyl group which may have a substituent" includes an unsubstituted pure phenyl group and a phenyl group having a substituent.

[ luminescent Compound ]

The luminescent compound of the present invention or a salt thereof is represented by the above formula (1). In the present specification, the "luminescent compound or a salt thereof" may be simply referred to as a "luminescent compound".

In the formula (1), at least one of X and Y (independently of each other) is selected from the group consisting of a nitro group, an amino group which may have a substituent, an amide group which may have a substituent, an alkyl group having from C1 to 4 (carbon atoms 1 to 4) which may have a substituent, an alkoxy group having from C1 to 4 which may have a substituent, an aromatic group which may have a substituent, and a heterocyclic group which may have a substituent, and when X or Y is not the above-mentioned selected group, X or Y is selected from an arbitrary substituent, M independently represents a hydrogen atom, a metal ion, or an ammonium ion, M independently represents an integer of from 0 to 2, and s is 0 or 1.

The "amino group which may have a substituent" mentioned above in the definitions of X and Y may be exemplified by amino groups; mono-substituted amino groups such as methylamino, ethylamino, n-butylamino, anilino, naphthylamino and the like; and di-substituted amino groups such as dimethylamino, diethylamino, di-n-butylamino, diphenylamino, ethylmethylamino, and ethylanilino.

The "amide group which may have a substituent" in the definitions of X and Y may be exemplified by: and a methylamide group, an ethylamide group, a phenylamide group, and the like. The substituent represented by the formulae (2) and (8) described below is also included in the "amide group which may have a substituent", and is one of more preferred embodiments thereof.

Examples of the "C1 to 4 alkyl group" of the above-mentioned "C1 to 4 alkyl group which may have a substituent(s)" in the definitions of X and Y include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, cyclobutyl and the like.

The "alkoxy group of C1 to 4" of the above-mentioned "alkoxy group of C1 to 4 which may have a substituent" in the definitions of X and Y may be exemplified by methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, cyclobutoxy and the like.

Examples of the "aromatic group" of the above-mentioned "aromatic group which may have a substituent" in the definitions of X and Y include phenyl, naphthyl, scallion group and the like.

The "heterocyclic group" of the "heterocyclic group which may have a substituent(s)" in the definitions of X and Y represents, for example, a heterocyclic ring having at least one of an oxygen atom, a nitrogen atom and a sulfur atom as a ring constituent, and these include not only monocyclic heterocyclic rings but also polycyclic heterocyclic rings in which the monocyclic heterocyclic ring further contains an aromatic ring such as a benzene ring or a naphthalene ring. Examples of the "heterocyclic group containing at least one of an oxygen atom, a nitrogen atom and a sulfur atom as a ring constituent" include a pyrrolyl group, a benzopyrolyl group, a thienyl group, a benzothienyl group, a thiazolyl group, a benzothiazolyl group, a naphthothiazolyl group, a triazolyl group, a benzotriazolyl group, a naphthotriazolyl group, a thiadiazolyl group, a benzothiadiazolyl group, a pyridyl group, a furyl group and a benzofuryl group.

The substituents in the above-mentioned "alkyl group of C1 to 4 which may have a substituent", "alkoxy group of C1 to 4 which may have a substituent", "aromatic group which may have a substituent", "heterocyclic group which may have a substituent" are not particularly limited, and examples thereof include nitro, hydroxyl, cyano, phosphoric acid group, sulfo, carboxyl, amino and the like. The "amino group which may have a substituent" and the "amido group which may have a substituent" may further have a substituent as exemplified herein.

Each M in the formula (1) represents independently a hydrogen atom, a metal ion, or an ammonium ion. Examples of the metal ions include alkali metal ions such as lithium ions, sodium ions, and potassium ions, and alkaline earth metal ions such as calcium ions and magnesium ions. The ammonium ion may be exemplified by ammonium ion (NH) in a narrow sense₄ ⁺) Methyl ammonium ion, dimethyl ammonium ion, triethyl ammonium ion, tetraethyl ammonium ion, tetra-n-propyl ammonium ion, tetra-n-butyl ammonium ion, monoethanol ammonium ion, diethanol ammonium ion, triethanol ammonium ion, monoisopropanol ammonium ion, diisopropanol ammonium ion, triisopropanol ammonium ion, triethanol ammonium ion, and the like. More specifically, for example, M represents a sulfonic acid (-SO) when M is a hydrogen atom₃H) And M represents sodium sulfonate (-SO) when M is sodium ion₃Na), M represents ammonium sulfonate (-SO) when M is ammonium ion₃NH₄). Particularly preferred examples of such ions include: lithium ions, ammonium ions, and sodium ions.

In the above formula (2), R represents hydrogenAn atom, an alkyl group of C1 to 4, an alkyl group of C1 to 4 having a sulfo group, or a substituent selected from the group consisting of substituents represented by formulae (3) to (7), wherein in formulae (3) and (4), a is a group independently selected from the group consisting of a hydrogen atom, a halogen group, a nitro group, a hydroxyl group, an alkyl group of C1 to 4, an alkoxy group of C1 to 4, an alkyl group of C1 to 4 having a sulfo group, an alkyl group of C1 to 4 having a hydroxyl group, an alkyl group of C1 to 4 having a carboxyl group, an alkoxy group of C1 to 4 having a sulfo group, an alkoxy group of C1 to 4 having a hydroxyl group, and an alkoxy group of C1 to 4 having a carboxyl group, q¹Represents an integer of 0 to 4, M in the above formulae (3) to (7) is as defined in the above formula (1), and n in the above formulae (3) and (4)¹N in the above formulae (5) to (7)²Each independently represents an integer of 0 to 3, t in the formula (8) is 0 or 1, Z represents a group selected from a phenyl group which may have a substituent, a naphthyl group which may have a substituent, a benzoyl group which may have a substituent, a heterocyclic group which may have a substituent, or a stilbene group which may have a substituent, and wherein X represents a bonding position in X or Y in the formula (1).

Examples of the "C1-4 alkyl group" in the definition of R include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, cyclobutyl and the like.

Examples of the "C1 to 4 alkyl group having a sulfo group" in the definition of R include sulfomethyl, sulfoethyl, sulfon-propyl, sulfon-butyl, sulfosec-butyl and the like.

Examples of the "halogen group" in the definition of A include a fluorine group, a chlorine group, a bromine group, an iodine group and the like.

The above-mentioned "alkyl group of C1 to 4" in the definition of A is as defined in R.

As the above-mentioned "alkoxy group of C1 to 4" in the definition of A, there can be exemplified methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, cyclobutoxy group and the like.

The above-mentioned "C1 to 4 alkyl group having a sulfo group" in the definition of A is as defined in R.

Examples of the "C1-4 alkyl group having a hydroxyl group" in the definition of A include hydroxymethyl, hydroxyethyl, hydroxy-n-propyl, hydroxyisopropyl, hydroxy-n-butyl, hydroxy-sec-butyl, hydroxy-tert-butyl, and hydroxycyclobutyl.

Examples of the "C1-4 alkyl group having a carboxyl group" in the definition of A include carboxymethyl, carboxyethyl, carboxyl-n-propyl, carboxyisopropyl, carboxyl-n-butyl, carboxyl-sec-butyl, carboxyl-tert-butyl, and carboxycyclobutyl.

The above-mentioned "alkoxy group of C1 to 4 having a sulfo group" in the definition of A may be exemplified by sulfomethoxy, sulfoethoxy, sulfo-n-propoxy, sulfoisopropoxy, sulfo-n-butoxy, sulfo-sec-butoxy, sulfo-tert-butoxy, sulfocyclobutoxy and the like.

Examples of the above-mentioned "alkoxy group of C1 to 4 having a hydroxyl group" in the definition of A include a hydroxymethoxy group, a hydroxyethoxy group, a hydroxyl-n-propoxy group, a hydroxyl-isopropoxy group, a hydroxyl-n-butoxy group, a hydroxyl-sec-butoxy group, a hydroxyl-tert-butoxy group, a hydroxyl-cyclobutoxy group and the like.

Examples of the "alkoxy group having C1 to 4 of a carboxyl group" in the definition of A include carboxymethoxy group, carboxyethoxy group, carboxy-n-propoxy group, carboxy-isopropoxy group, carboxy-n-butoxy group, carboxy-sec-butoxy group, carboxy-tert-butoxy group, carboxy-cyclobutoxy group and the like.

The "heterocyclic group" of the above-mentioned "heterocyclic group which may have substituents" in the definition of Z is as defined in X and Y.

The substituents in the above-mentioned "phenyl group which may have a substituent", "naphthyl group which may have a substituent", "benzoyl group which may have a substituent", "heterocyclic group which may have a substituent", and "stilbenyl group which may have a substituent" in the definition of Z are not particularly limited, and may be, for example, the same as the substituents exemplified above for the above-mentioned "alkyl group which may have a substituent C1 to 4" in the definition of X and Y.

M in the above formulae (3) to (7) is as defined above for the formula (1).

X and Y in the above formula (1) are preferably each independently a nitro group, an amino group which may have a substituent, an amide group which may have a substituent, an alkyl group of C1 to 4 which may have a substituent, an alkoxy group of C1 to 4 which may have a substituent, an aromatic group which may have a substituent, a heterocyclic group which may have a substituent, or a substituent selected from the group consisting of substituents represented by the above formulae (2) to (8); more preferably, at least one of X and Y in the above formula (1) (which are independent of each other) is selected from the group consisting of substituents represented by the formulae (2) to (8); at least one of X and Y in the above formula (1) (each independently) is selected from the group consisting of substituents represented by formulae (2) to (8), and when a substituent represented by formula (8) is selected, Z in formula (8) is more preferably selected from the group consisting of substituents represented by formulae (2) to (7); in the above formula (1), either one of X and Y is a nitro group or an amino group which may have a substituent, and the other is a substituent selected from the group consisting of the substituents represented by the formulae (2) to (8), and when the substituent represented by the formula (8) is selected, Z is more preferably a substituent selected from the group consisting of the substituents represented by the formulae (2) to (7); either one of X and Y in the formula (1) is nitro or an amino group which may have a substituent, the other is a substituent represented by the formula (8), and Z in the formula (8) is more preferably nitro or an amino group which may have a substituent; more preferably, X and Y are both nitro or amino which may have a substituent; x and Y in the above formula (1) are each selected from the group consisting of substituents represented by the formulae (2) to (8), and when a substituent represented by the formula (8) is selected, Z is more preferably selected from the group consisting of substituents represented by the formulae (2) to (7).

In one embodiment of the present invention, each m is 0.

In one embodiment of the present invention, s is 0. Next, a method for synthesizing the compound represented by the formula (1) in this embodiment will be described.

For example, 1 equivalent of each of the compound represented by formula (10) and the compound represented by formula (11) is heated in water, and sodium hydroxide is added thereto and dissolved. The desired compound was obtained by adding 1 equivalent of 4, 4' -biphenyldicarbonyl chloride represented by formula (9) which is commercially available and reacting.

In the above formulae (9) to (11), each of X, Y, M and m is defined as the above formula (1).

Next, specific examples of the luminescent compound represented by the above formula (1) or a salt thereof, wherein s is 0, are given below. The sulfo group and the like in the formula are represented in the form of a free acid.

In one embodiment of the present invention, s is 1. Next, a method for synthesizing the compound represented by the formula (1) in this embodiment will be described.

For example, 1 equivalent of each of the compound represented by the following formula (s10) and the compound represented by the following formula (s11) is heated in water, and sodium hydroxide is added thereto and dissolved. The desired compound was obtained by adding 1 equivalent of 4, 4' -biphenyldicarbonyl chloride represented by the following formula (9) which is commercially available and reacting.

In the above formulae (9), (s10), and (s11), X, Y, M and m are each as defined above for formula (1).

Next, specific examples of the luminescent compound represented by the above formula (1) or a salt thereof, wherein s is 1, are given below. The sulfo group and the like in the formula are represented in the form of a free acid.

The compound represented by the above formula (1) or a salt thereof is useful as a compound which can emit polarized light. A polarized light emitting device can be produced by aligning a substrate, for example, a polymer film such as polyvinyl alcohol or a derivative thereof, with 1 or more kinds of combinations of a compound represented by the formula (1) or a salt thereof and optionally an organic dye or a fluorescent dye other than the luminescent compound or a salt thereof by a publicly known method. The obtained polarized light emitting element is used as a polarized light emitting plate with a transparent protective film, and a hard coating layer (protective layer) or an AR (anti-reflection) layer and a support are optionally further provided on the polarized light emitting plate, and is applied to liquid crystal projectors, computers, clocks, notebook computers, document processors, liquid crystal televisions, car navigation, safety displays, anti-counterfeiting, indoor and outdoor measuring instruments or displays, lenses, glasses, and the like. In the present specification, the organic dye or fluorescent dye other than the luminescent compound or salt thereof of the present invention may be simply referred to as "other organic dye".

[ polarized light-emitting element ]

The present invention also includes a polarized light-emitting element containing the light-emitting compound represented by the above formula (1) or a salt thereof.

The polarized light emitting element preferably contains a light emitting compound represented by the above formula (1) or a salt thereof, and a substrate to which the polarized compound or a salt thereof is adsorbed and oriented. The polarized light-emitting element may contain one or more of the luminescent compounds represented by the above formula (1) or salts thereof alone.

The substrate is preferably a film obtained by forming a hydrophilic polymer film capable of adsorbing the luminescent compound represented by formula (1) or a salt thereof, or the like. The hydrophilic polymer is not particularly limited, and examples thereof include polyvinyl alcohol-based resins, amylose-based resins, starch-based resins, cellulose-based resins, and polyacrylate-based resins. Among such resins, polyvinyl alcohol resins or derivatives thereof are more preferable from the viewpoints of the adsorptivity, processability, orientation and the like of the luminescent compound represented by the formula (1) or a salt thereof. Any polyvinyl alcohol resin derivative generally known in the art can be used as the polyvinyl alcohol resin derivative. Examples of the resin include, but are not particularly limited to, unsaturated carboxylic acids such as crotonic acid, acrylic acid, methacrylic acid, and maleic acid, unsaturated sulfonic acids such as vinylsulfonic acid, propenesulfonic acid, methacrylsulfonic acid, p-styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (meth) acryloyloxyethylsulfonic acid, and modified polyvinyl alcohol resins obtained by copolymerizing an olefin such as ethylene or propylene with vinyl alcohol. The shape of the substrate is not particularly limited, and the substrate may be formed into any shape such as a film, a sheet, a flat plate, a curved plate, or a hemisphere. In addition, the thickness of the substrate is usually 10 to 100. mu.m, more preferably 20 to 80 μm.

The content of the luminescent compound represented by the formula (1) in the polarized light emitting element is not particularly limited, and the amount of the luminescent compound can be set in accordance with an arbitrary transmittance, and the amount of the luminescent compound (the amount of the luminescent compound) can be arbitrarily set in accordance with the transmittance required for the polarized light emitting element. The polarization performance of the polarized light emitting element varies not only by the blending ratio of the luminescent compound represented by formula (1) contained in the polarized light emitting element but also by various factors such as the degree of swelling, the stretching ratio, the dyeing time, the dyeing temperature, the pH at the time of dyeing, and the influence of salts of the substrate to which the luminescent compound is adsorbed. Therefore, the blending ratio of the luminescent compound represented by the formula (1) contained in the polarized light emitting element can be determined in accordance with the swelling degree of the substrate, the dyeing temperature, the dyeing time, the pH at the time of dyeing, the kind of salt, the salt concentration, the stretching ratio, and the like. The blending ratio can be adjusted as appropriate.

The polarized light emitting element may optionally further contain one or more other organic dyes in a range not to hinder the polarizing performance or for the purpose of color adjustment. The other organic dye to be used in combination is not particularly limited, but a dye having high dichroism is more preferable, and a dye having less influence on the polarizing performance in the absorption band region of the light-emitting compound represented by formula (1), for example, from the ultraviolet region to the near-ultraviolet visible region is more preferable. Other organic dyes to be used in combination are exemplified by c.i. direct yellow 12, c.i. direct yellow 28, c.i. direct yellow 44, c.i. direct orange 26, c.i. direct orange 39, c.i. direct orange 71, c.i. direct orange 107, c.i. direct red 2, c.i. direct red 31, c.i. direct red 79, c.i. direct red 81, c.i. direct red 247, c.i. direct blue 69, c.i. direct blue 78, c.i. direct green 80, and c.i. direct green 59. These other organic dyes may be in the form of free acids, alkali metal salts (e.g., Na, K, and Li salts), ammonium salts, or salts of amines.

When the other organic dyes are optionally used in combination, the kinds of the other organic dyes to be blended may be selected according to the purpose of color adjustment of a polarized light emitting device for the production purpose. The content is not particularly limited, and in general, when the mass of the luminescent compound represented by the above formula (1) is 1, the total mass of other organic dyes used in combination is preferably in the range of 0.01 to 10.

< method for producing polarized light emitting device >

Next, a method for manufacturing the polarized light emitting device of the present invention will be described. The production method is not limited to the following method, and may include, for example, the following steps: preparing a base material; a swelling step of immersing the base material in a swelling liquid and extending the base material by swelling; a dyeing step of immersing the swelled substrate in a dyeing solution containing at least 1 luminescent compound represented by the above formula (1), and allowing the substrate to adsorb the luminescent compound represented by the formula (1); a crosslinking step of immersing the base material having the luminescent compound represented by the formula (1) adsorbed thereon in a solution containing a crosslinking agent such as boric acid to crosslink the luminescent compound represented by the formula (1) in the base material; an extension step of uniaxially extending a base material, which is obtained by crosslinking a luminescent compound represented by formula (1), in a fixed direction, and arranging the luminescent compound represented by formula (1) in the fixed direction; a washing step of washing the extended substrate with a washing liquid; and a drying step of drying the washed substrate.

(preparation of base Material)

A substrate containing a light-emitting compound represented by the above formula (1) is prepared. The substrate can be produced by forming a film of a polyvinyl alcohol resin, for example, using a commercially available film containing a polyvinyl alcohol resin or a derivative thereof. The method for forming the film of the polyvinyl alcohol resin is not particularly limited, and publicly known film forming methods such as a method of melt-extruding aqueous polyvinyl alcohol, a casting film forming method, a wet film forming method, a gel film forming method (after the aqueous polyvinyl alcohol solution is once cooled and gelled, the solvent is removed by extraction), a casting film forming method (after the aqueous polyvinyl alcohol solution is fluidized and dried on the substrate), and a method combining these methods can be used. Polyvinyl alcohol having a degree of polymerization of 1000 to 10000 can be used, and the degree of polymerization is more preferably 1500 to 6000, and still more preferably 2000 to 6000.

(swelling step)

Then, the base material is subjected to swelling treatment. The swelling treatment is preferably carried out by immersing the substrate in a swelling liquid at 20 to 50 ℃ for 30 seconds to 10 minutes, and the swelling liquid is preferably water. The draw ratio of the swelling liquid to the base material is preferably adjusted to 1.00 to 1.50 times, more preferably to 1.10 to 1.35 times.

(dyeing step)

Then, at least 1 kind of light-emitting compound represented by formula (1) or a salt thereof is adsorbed and impregnated on the base material obtained by the swelling treatment. The dyeing step is not particularly limited as long as the substrate is adsorbed and impregnated with the luminescent compound represented by formula (1) or a salt thereof, and for example, it is preferable to immerse the substrate in a dyeing solution containing the luminescent compound represented by formula (1) or a salt thereof, and the adsorption may be performed by applying the dyeing solution to the substrate. The concentration of the luminescent compound represented by the formula (1) or a salt thereof in the dyeing solution is not particularly limited as long as the luminescent compound represented by the formula (1) or a salt thereof can be sufficiently adsorbed in the substrate, and is, for example, more preferably 0.0001 to 3% by mass, and still more preferably 0.001 to 1% by mass in the dyeing solution.

The temperature of the above-mentioned dyeing solution in the dyeing step is preferably 5 to 80 ℃, more preferably 20 to 50 ℃, particularly preferably 40 to 50 ℃. The time for immersing the base material in the dyeing solution may be appropriately adjusted, and is preferably adjusted to 30 seconds to 20 minutes, and more preferably 1 to 10 minutes.

As the compound contained in the dyeing solution, 1 kind of the luminescent compound represented by the formula (1) may be used alone or 2 or more kinds may be used in combination. Since the luminescent compound represented by the above formula (1) has a different luminescent color due to the difference in structure, the luminescent color to be produced can be appropriately adjusted to a desired color by adding 2 or more luminescent compounds represented by the above formula (1) or salts thereof, or a luminescent compound represented by the above formula (1) or salts thereof and 1 or more other luminescent compounds to the base material. In addition, the dyeing solution may optionally further contain 1 or 2 or more of the above-mentioned other organic dyes. In the description of the production of the polarized light emitting device and the polarized light emitting panel in the present specification, the luminescent compound represented by the formula (1) and other organic dyes may be collectively referred to as "a polarized pigment".

The dyeing solution may optionally further contain a dyeing assistant in addition to the above-mentioned polarizing pigment. Examples of the dyeing assistant include sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulfate (mirabilite), anhydrous sodium sulfate, and sodium tripolyphosphate, and sodium sulfate is more preferable. The content of the dyeing assistant can be arbitrarily adjusted by the above-mentioned dipping time and the temperature of the dyeing solution according to the dyeing property of the dichromatic dye to be used, but is preferably 0.1 to 10% by mass, more preferably 0.1 to 2% by mass in the dyeing solution.

After the dyeing step, a preliminary washing step may be optionally performed in order to remove the dyeing solution attached to the surface of the substrate in the dyeing step. By performing the preliminary washing step, the luminescent compound represented by the formula (1) or a salt thereof remaining on the surface of the substrate can be suppressed from being transferred to the treatment liquid in the following steps. In the preliminary washing step, water is generally used as the washing liquid. The washing method is preferably carried out by impregnating the dyed substrate with a washing liquid, and on the other hand, the substrate can be washed by applying a washing liquid thereto. The washing time is not particularly limited, and is preferably 1 to 300 seconds, more preferably 1 to 60 seconds. In the preliminary washing step, the temperature of the washing liquid needs to be a temperature at which the material constituting the substrate is not dissolved, and the washing treatment is generally performed at 5 to 40 ℃. In addition, the performance of the polarized light emitting element is not greatly affected even if the preliminary washing step is not provided, and therefore the preliminary washing step can be omitted.

(crosslinking step)

The dyeing step or the preliminary washing step may be followed by a crosslinking agent in the substrate. The method of containing the crosslinking agent in the substrate is more preferably a method of immersing the substrate in a treatment solution containing the crosslinking agent, and the treatment solution may be applied or coated on the substrate. The crosslinking agent in the treatment solution is preferably a solution containing boric acid. The solvent in the treatment solution is not particularly limited, and water is more preferable. The concentration of the crosslinking agent such as boric acid in the treatment solution is more preferably 0.1 to 15% by mass, and still more preferably 0.1 to 10% by mass. The temperature of the treatment solution is more preferably 30 to 80 ℃, more preferably 40 to 75 ℃. In addition, the treatment time of the crosslinking step is more preferably 30 seconds to 10 minutes, and more preferably 1 to 6 minutes. The method for manufacturing a polarized light emitting element of the present invention has the crosslinking step, and thus the obtained polarized light emitting element can emit light having high brightness and high polarization degree. This is an excellent effect which could not be expected at all from the function of boric acid used in the prior art for the purpose of improving moisture resistance or light transmittance. In the crosslinking step, the fixing treatment may be further carried out together with an aqueous solution containing a cationic polymer compound. The polarizing pigment can be immobilized by the fixing treatment. In this case, the cationic polymer compound may be, for example, a cation releasing compound, a dicyan compound, a polyamine compound, a polycationic compound, a dimethyldiallylammonium chloride/dioxide ion copolymer, a diallylamine salt polymer, a dimethyldiallylammonium chloride polymer, an allylamine salt polymer, or a dialkylaminoethyl acrylate quaternary salt polymer. The dicyan-based compound is exemplified by dicyanamide/formalin polycondensate. The polyamine-based compound may be exemplified by dicyanodiamine/diethylenetriamine condensate. The polycationic compound may be exemplified by epichlorohydrin/dimethylamine addition polymer.

(elongation step)

The extension step may be performed after or simultaneously with the crosslinking step. The stretching step is performed by uniaxially stretching the base material in a fixed direction. The stretching method may be either a wet stretching method or a dry stretching method. The draw ratio is more preferably 3 times or more, and still more preferably 5 to 9 times.

In the dry stretching method, when the stretching heating medium is an air medium, it is preferable that the stretching of the base material is performed at a temperature of the air medium of from room temperature to 180 ℃. Further, the humidity is more preferably in an environment of 20 to 95% RH. Examples of the method of heating the substrate include, but are not limited to, inter-roll stretching, roll heating stretching, hot-roll stretching, and infrared heating stretching. The dry extension step may be carried out by one-stage extension or by multi-stage extension with two or more stages.

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 1 crosslinking agent. The crosslinking agent may be boric acid in the crosslinking agent step, and it is preferable to perform the elongation treatment in the treatment solution used in the crosslinking step. The extension temperature is more preferably 40 to 70 ℃, more preferably 45 to 60 ℃. The extension time is usually 30 seconds to 20 minutes, more preferably 2 to 7 minutes. The wet stretching step may be performed by one-stage stretching, or may be performed by multi-stage stretching with two or more stages. In addition, the stretching treatment may be optionally performed before the dyeing step, and in this case, the alignment of the luminescent compound represented by the formula (1) or a salt thereof may be performed together at the time point of dyeing.

(washing step)

Since the crosslinking agent is precipitated or foreign matter is attached to the surface of the substrate after the extension step is performed, a cleaning step for cleaning the surface of the substrate can be performed. The washing time is more preferably 1 second to 5 minutes. The washing method is preferably a method in which the substrate is immersed in a washing liquid, but the substrate may be washed by applying or coating the washing liquid to the substrate. The washing liquid is preferably water. The washing treatment may be carried out in one stage, or may be carried out in a multistage treatment comprising two or more stages. The temperature of the washing solution in the washing step is not particularly limited, and is usually 5 to 50 ℃, preferably 10 to 40 ℃, and may be normal temperature.

The solvent of the solution or the treatment solution used in each step may be, for example, alcohols or amines in addition to the water. Examples of the alcohols include dimethyl sulfoxide, N-methylpyrrolidone (methyl pyrrolidone), methanol, ethanol, propanol, isopropanol, glycerol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and trimethylolpropane. Examples of the amines include ethylenediamine and diethylenetriamine. The solvent of the solution or the treatment solution is not limited to these, but water is most preferable. The solvent for these solutions or treatment solutions may be used alone in 1 kind, or may be a mixture of 2 or more kinds.

(drying step)

The washing step is preferably followed by a drying step of the substrate. The drying treatment may be performed by natural drying, but in order to improve drying efficiency, it may be performed by removing surface moisture or the like by compression with a roller, an air knife, a water suction roller or the like, or may be performed by air-blow drying. The temperature of the drying treatment is more preferably 20 to 100 ℃, and still more preferably 60 to 100 ℃. The drying time is more preferably 30 seconds to 20 minutes, and still more preferably 5 to 10 minutes.

The polarized light emitting device of the present invention can be produced by taking the above description as an example. In addition, the light-emitting compound represented by formula (1) in the present invention can be aligned by a method of mixing with a liquid crystal and aligning on a substrate, or by a method of sharing and coating on a substrate, whereby a polarized light-emitting element having various colors or neutral gray can be manufactured.

[ polarizing light-emitting sheet ]

The present invention also includes a polarized light emitting panel including the above polarized light emitting element.

The polarized light emitting panel of the present invention preferably has a transparent protective film on at least one surface of the polarized light emitting element. The transparent protective film is used to improve the water resistance, handling property, and the like of the polarized light emitting element. Therefore, it is preferable that the transparent protective film does not affect the polarization function exhibited by the polarized light emitting device of the present invention.

The transparent protective film is preferably a transparent protective film having excellent optical transparency and mechanical strength. The transparent protective film is preferably a film having a layer shape that can maintain the shape of the polarized light emitting element, and is preferably a plastic film having excellent thermal stability, moisture shielding property, and the like, in addition to transparency and mechanical strength. Examples of the material for forming such a transparent protective film include a cellulose acetate film, an acrylic film, a fluorine film such as a tetrafluoroethylene/hexafluoropropylene copolymer, a film made of a polyester resin, a polyolefin resin, or a polyamide resin, and a cellulose Triacetate (TAC) film or a cycloolefin film is preferably used. The thickness of the transparent protective film is more preferably in the range of 1 to 200. mu.m, more preferably in the range of 10 to 150. mu.m, particularly preferably in the range of 40 to 100. mu.m. The method for producing the polarized light emitting panel of the present invention is not particularly limited, and for example, a polarized light emitting panel can be produced by laminating a transparent protective film on a polarized light emitting element in a publicly known formulation.

The polarized light emitting panel may further include an adhesive layer between the transparent protective film and the polarized light emitting element for bonding the transparent protective film to the polarized light emitting element. The adhesive agent constituting the adhesive agent layer is not particularly limited, and examples thereof include: a polyvinyl alcohol adhesive, a urethane emulsion adhesive, an acrylic adhesive, a polyester isocyanate adhesive, and the like, and a polyvinyl alcohol adhesive is preferably used. After the transparent protective film and the polarized light emitting element are bonded by the adhesive, the polarized light emitting panel can be manufactured by drying or heat treatment at an appropriate temperature.

The polarizing light-emitting panel may be provided with various publicly known functional layers such as an anti-reflection layer, an anti-glare layer, and a reinforcing transparent protective film on the exposed surface of the transparent protective film. When a layer having such various functionalities is produced, a method of applying a material having various functionalities to the exposed surface of the transparent protective film is more preferable, and on the other hand, a layer or a film having such functionalities may be bonded to the exposed surface of the transparent protective film via an adhesive or a pressure-sensitive adhesive.

Examples of the transparent protective film include hard coat layers such as acrylic, urethane, and silicone. In addition, in order to further improve the monomer transmittance, an anti-reflection layer can be arranged on the exposed surface of the transparent protective film. The antireflection layer can be formed by, for example, vapor-depositing or sputtering a substance such as silicon dioxide or titanium oxide on the transparent protective film, or by thinly coating a fluorine-based substance on the transparent protective film.

The above-mentioned polarized light-emitting panel may be further provided with a transparent support such as glass, crystal, sapphire, or the like. In order to bond the polarizing light-emitting panel, the support preferably has a flat surface portion, and in terms of optical use, a transparent support is more preferred. The transparent support is classified into an inorganic support and an organic support, and examples of the support made of an inorganic material include: examples of the organic support include supports made of materials such as soda glass, borosilicate glass, crystal, sapphire, and spinel, and examples of the organic support include: a support composed of an acrylate, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, a cycloolefin polymer, or the like. The thickness and size of the transparent support are not particularly limited and can be appropriately determined. In the polarized light emitting panel having such a transparent support, it is preferable to provide an antireflection layer on one or both of the support surface and the surface of the polarized light emitting panel in order to further improve the transmittance of the single body. In order to bond the polarized light-emitting panel and the support plane portion, a transparent adhesive (pressure-sensitive adhesive) may be applied to the support plane portion, and then the polarized light-emitting panel of the present invention may be bonded to the applied surface. The adhesive or binder to be used is not particularly limited, and commercially available products can be used, and an acrylate-based adhesive or binder is more preferable.

The polarized light emitting panel may be a circular polarized light emitting panel or an elliptical polarized light emitting panel to which a phase difference plate is attached. In this case, when a support is further provided for the polarized light emitting panel, the support may be a retardation plate. Examples of the phase difference plate include, but are not limited to, a plate having a phase difference value of 1/4 λ or a plate having a phase difference value of 1/2 λ with respect to an absorption wavelength or a light emission wavelength of light. Having a phase difference of 1/4 λ allows the plate to function as a circularly polarizing plate or a circularly polarizing light-emitting plate for that wavelength, and can be used to convert polarization into a 90 ° direction or the like by using 1/2 λ. As described above, the polarizing light-emitting panel can be further provided with various functional layers, supports, and the like, and thus, the polarizing light-emitting panel can be used for various products such as lenses, glasses, and the like for liquid crystal projectors, computers, clocks, notebook computers, document processors, liquid crystal televisions, car navigations, and indoor and outdoor measurement instruments and displays.

The polarized light emitting element and the polarized light emitting panel of the present invention can exhibit high polarization degree in the region from ultraviolet region to near ultraviolet visible region, for example, 300 to 430nm, and exhibit polarized light emission action and high transmittance in the visible region. The polarized light emitting element and the polarized light emitting panel of the present invention exhibit excellent durability against heat, humidity, light, and the like, and therefore can maintain their performance even under severe environments, and have high durability as compared with conventional iodine-based polarizing plates. Therefore, the polarized light emitting element and the polarized light emitting panel of the present invention can be applied to various display devices such as televisions, portable terminals, tablet terminals, smart phones, displays for vehicles, digital signage used outdoors or indoors, and smart windows, which require high transparency in the visible light region and high durability in a severe environment.

[ display device ]

The present invention also includes a display device (display) including the above-described polarized light emitting element or polarized light emitting panel.

The display device can display polarized light emission by irradiating light in the ultraviolet region to the visible region, for example, light in the ultraviolet region to the near ultraviolet visible region, specifically, light of 300 to 430nm, and can display by utilizing this effect. The display device of the invention has high transmittance in a visible light region, so that the transmittance of the prior polarizing plate in the visible light region is not reduced, and even if the transmittance is reduced, the reduction of the transmittance is obviously reduced compared with the transmittance of the prior polarizing plate. For example, in an iodine-based polarizing plate which is a conventional polarizing plate or a dye-based polarizing plate using another dye, the degree of polarization is almost 100%, and the visibility in the visible light region is corrected to about 35 to 45%. The reason is as follows: in the conventional polarizing plate, both a vertical axis and a horizontal axis are used as an absorption axis of light, but in order to obtain a degree of polarization of almost 100%, it is necessary to absorb incident light on one of the vertical axis and the horizontal axis, that is, to absorb light in one axis and to generate polarization by transmitting light in the other axis. At this time, since the light of one axis is absorbed without being transmitted, the transmittance is inevitably 50% or less. In addition, in the conventional polarizing plate, a dichroic dye is aligned in a stretched film, but the dichroic dye is not aligned at 100%, and has a slight absorption component with respect to the transmission axis of light. Therefore, if the transmittance is about 45% or less without reflection from the surface of the substance, a polarization degree of almost 100% cannot be realized, that is, if the transmittance is not lowered, a high polarization degree cannot be realized. On the other hand, the polarized light emitting element and the polarized light emitting panel of the present invention have an axis (its polarizing function) for absorbing light in the ultraviolet region to the near-ultraviolet visible region, for example, in the range of 300 to 430nm, that is, have an effect of absorbing light in the ultraviolet region to the near-ultraviolet visible region, for example, in the range of 300 to 430nm, and show a polarized light emitting effect of emitting polarized light in the visible region, and on the other hand, hardly absorb light in the visible region, so that the transmittance in the visible region is very high. Further, since the polarizing plate exhibits polarized light emission in the visible light region, the loss of light is less than that of the conventional polarizing plate, that is, the transmittance is less reduced as compared with the conventional polarizing plate. Therefore, a display device, for example, a liquid crystal display, using the polarized light emitting element and the polarized light emitting panel of the present invention can obtain higher brightness than a liquid crystal display including a conventional polarizing plate. In addition, since the display device using the polarized light emitting element and the polarized light emitting panel of the present invention has high transparency, the display device can be a liquid crystal display, but can be a nearly transparent display. In addition, when displaying characters and images, the design can be made in a way that polarized light is transmitted, so that although the display is a transparent liquid crystal display, a display capable of displaying characters and the like can be obtained, namely, the display capable of displaying characters and the like on the transparent display can be obtained. Therefore, the display device of the present invention can obtain a transparent liquid crystal display without light loss, particularly a see-through display.

In addition, the display device can be applied to a liquid crystal display which can be displayed by ultraviolet light because the display device can be polarized to light in the ultraviolet light region to the near ultraviolet visible light region which is invisible or difficult to see to human eyes, for example, to light of 300 to 430 nm. For example, by checking an image displayed in the ultraviolet region to the near-ultraviolet visible region with a computer or the like, a simple and highly safe liquid crystal display device can be produced, which is visible only when light in the ultraviolet region to the near-ultraviolet visible region, for example, light of 300 to 430nm is irradiated.

In addition, since the above-described display device displays polarized light emission by irradiating light in the ultraviolet region to the near-ultraviolet visible region, for example, light of 300 to 430nm, and a liquid crystal display using the polarized light emission can be manufactured, a liquid crystal display using light in the ultraviolet region to the near-ultraviolet visible region can be realized instead of a general liquid crystal display using visible light. That is, a light-emitting liquid crystal display device can be manufactured which can display characters, images, and the like to be displayed even in a dark space where visible light is not present, as long as the space can be irradiated with light from an ultraviolet region to a near-ultraviolet visible region.

Further, since the visible light region and the ultraviolet light region have different light bands, a display in which 2 kinds of different displays are present simultaneously can be manufactured, and a liquid crystal display portion which can display light in the visible light region and a liquid crystal display portion which can display light by polarization light emission action by ultraviolet light can be manufactured. There are displays capable of 2 different displays, but there are no displays in which the same liquid crystal panel can perform different displays by different light sources in the ultraviolet region and the visible region. In this way, the display device of the present invention can produce a novel display by using the above-described polarized light emitting element or polarized light emitting panel.

The present invention also includes a liquid crystal display including the above-described polarized light emitting element, polarized light emitting panel, or display device. The liquid crystal cell used in the liquid crystal display is not limited to, for example, a TN liquid crystal cell, an STN liquid crystal cell, a VA liquid crystal cell, an IPS liquid crystal cell, and the like, and can be used in various liquid crystal display modes. The liquid crystal display has high durability, and thus can be provided for a liquid crystal display for vehicle or outdoor display.

The present invention also includes a neutral gray-polarized light-emitting panel for automotive or outdoor display, which includes the above-described polarized light-emitting element, polarized light-emitting panel, or display device. The neutral gray-polarized light-emitting panel for automotive or outdoor display is excellent in polarized light-emitting performance and is free from discoloration or deterioration in polarized light performance even in a high-temperature or high-humidity state inside or outside an automobile. The neutral gray refers to a light-emitting polarizing plate having a transmittance at a cross-point in the visible light region, in which the transmittance at each wavelength is significantly reduced or has a constant transmittance. Specifically, the cross-site transmittance is 0.3% or less, more preferably 0.1% or less, still more preferably 0.03% or less, and particularly preferably 0.01% or less, and the fixed transmittance means that the difference in transmittance with respect to the average transmittance at each wavelength is 1% or less.

[ examples ]

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples. In addition, "%" and "part(s)" described below are based on mass unless otherwise specified. In the respective structural formulae of the compounds used in the examples and comparative examples, the acidic functional group such as sulfo group is described as a free acid.

[ example 1]

(Synthesis example)

84 parts of the compound represented by the formula (25) was added to 1000 parts of water, heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. 27.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 73.4 parts of a compound represented by formula (16).

(preparation of polarized light emitting element and polarized light emitting Panel)

A polyvinyl alcohol film (VF-PS #7500 manufactured by Kuraray Co., Ltd.) having a thickness of 75 μm was immersed in water at 40 ℃ for 3 minutes to swell the film. The membrane obtained by swelling was immersed in an aqueous solution at 45 ℃ containing 0.2 part by mass of the compound represented by formula (16) obtained in synthesis example 1, 1.0 part by mass of mirabilite, and 1000 parts by mass of water for 4 minutes, so that the compound represented by formula (16) was contained in the membrane. The film containing the compound represented by formula (16) was stretched 5-fold in a 3% aqueous solution of boric acid at 50 ℃ for 5 minutes. The stretched film was washed with water at normal temperature for 20 seconds while being kept under tension, and dried at 70 ℃ to obtain a polarized light emitting device. On both sides of the obtained polarized light emitting element, a 60 μm thick ultraviolet absorber-free cellulose triacetate film (ZRD-60 manufactured by FUJIFILM Co.) subjected to surface saponification treatment with 1.5N sodium hydroxide was laminated with a 4 mass% aqueous solution of polyvinyl alcohol (NH-26 manufactured by JAPAN VAN & POVAL Co.) as an adhesive to obtain a polarized light emitting panel, which was used as a measurement sample of example 1.

In addition, even when a cellulose triacetate film (ZRD-60 manufactured by FUJIFILM corporation) containing no ultraviolet absorber was bonded to the polarized light emitting element, the optical characteristics of the polarized light emitting element were not affected at all. In the following examples and comparative examples, a cellulose triacetate film containing no ultraviolet absorber was also bonded to the polarized light emitting element, and similarly, the optical characteristics were not affected at all.

[ example 2]

61.6 parts of a compound represented by the formula (26) was added to 600 parts of water, heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. 27.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, it was allowed to cool to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 57.5 parts of a compound represented by the formula (15). In the preparation of the polarized light emitting element and the polarized light emitting panel of example 1, the measurement sample of example 2 was obtained in the same manner except that the compound represented by formula (15) was used instead of the compound represented by formula (16).

[ example 3]

21.8 parts of a compound represented by formula (27) and 10.8 parts of a compound represented by formula (28) were added to 400 parts of water, 25% sodium hydroxide was added to dissolve the above compounds while adjusting the pH to 6 to 7, and 15.6 parts of phenyl chloroformate was stirred at 50 to 70 ℃ for 6 hours to effect ureidoization. Salting out with sodium chloride, filtration and drying at 70 ℃ give 24.6 parts of a ureido compound of the formula (29). 24.6 parts of the obtained ureido compound represented by formula (29) and 27.8 parts of 4, 4' -biphenyldicarbonyl chloride were added to 1000 parts of water, and the mixture was heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. 9.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 12.2 parts of a compound represented by formula (20). In the preparation of the polarized light emitting element and the polarized light emitting panel of example 1, the measurement sample of example 3 was obtained in the same manner except that the compound represented by formula (20) was used instead of the compound represented by formula (16).

[ example 4]

61.6 parts of a compound represented by the formula (30) was added to 600 parts of water, heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. 27.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 57.5 parts of a compound represented by formula (18). In the preparation of the polarized light emitting element and the polarized light emitting panel of example 1, the measurement sample of example 4 was obtained in the same manner except that the compound represented by formula (18) was used instead of the compound represented by formula (16).

[ example 5]

21.6 parts of formula (28) was added to 600 parts of water, heated to 60 ℃ and 25% sodium hydroxide was added to dissolve the compound while adjusting the pH to 6 to 7. 27.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 35.2 parts of a compound represented by formula (31). 35.2 parts of a compound represented by the formula (31) and 66.7 parts of 4-nitro-4 '-aminostilbene-2, 2' -disulfonic acid are added to 800 parts of water, heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. Phenyl chloroformate 25.9 parts was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 66.5 parts of a compound represented by formula (22). In the preparation of the polarized light emitting element and the polarized light emitting panel of example 1, the measurement sample of example 5 was obtained in the same manner except that the compound represented by formula (22) was used instead of the compound represented by formula (16).

[ example s1]

80 parts of 4-nitro-4 '-aminostilbene-2, 2' -disulfonic acid was added to 1000 parts of water, heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. 27.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the obtained solid was dried at 70 ℃ to obtain 70 parts of a compound represented by the formula (s 14). In the production of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of example s1 was obtained in the same manner as described above, except that the compound represented by the formula (s14) was used instead of the compound represented by the formula (16).

[ example s2]

136 parts of the compound represented by the formula (s28) was added to 1000 parts of water, heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. 27.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the obtained solid was dried at 70 ℃ to obtain 103 parts of a compound represented by the formula (s 15). In the production of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of example s2 was obtained in the same manner as described above, except that the compound represented by the formula (s15) was used instead of the compound represented by the formula (16).

[ example s3]

40 parts of 4-nitro-4 '-aminostilbene-2, 2' -disulfonic acid and 68.2 parts of a compound represented by the formula (s28) were added to 1000 parts of water, heated to 60 ℃ and dissolved by adding 25% sodium hydroxide while adjusting the pH to 6 to 7. 40 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, it was allowed to cool to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 90.1 parts of a compound represented by the formula (s 29). In the production of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of example s3 was obtained in the same manner as described above, except that the compound represented by the formula (s29) was used instead of the compound represented by the formula (16).

[ example s4]

74.0 parts of 4,4 '-diaminostilbene-2, 2' -disulfonic acid was added to 1000 parts of water and heated to 60 ℃ and 25% sodium hydroxide was added to dissolve the above-mentioned compounds while adjusting the pH to 6 to 7. 27.8 parts of 4, 4' -biphenyldicarbonyl chloride was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, it was cooled to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 66.2 parts of a compound represented by the formula (s 12). In the production of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of example s4 was obtained in the same manner as described above, except that the compound represented by the formula (s12) was used instead of the compound represented by the formula (16).

[ example s5]

94.6 parts of the compound represented by the formula (s12) obtained in example 4 and 80 parts of 4-nitro-4 '-aminostilbene-2, 2' -disulfonic acid were added to 1000 parts of water, and the mixture was heated to 60 ℃ and dissolved in 25% sodium hydroxide while adjusting the pH to 6 to 7. Phenyl chloroformate 31.2 parts was added in small portions over about 1 hour. After all the addition, the reaction was stirred at 60 ℃ for 1 hour. After the reaction was completed, the reaction mixture was cooled to room temperature and filtered, and the resulting solid was dried at 70 ℃ to obtain 122.2 parts of a compound represented by the formula (s 19). In the production of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of example s5 was obtained in the same manner as described above, except that the compound represented by the formula (s19) was used instead of the compound represented by the formula (16).

Comparative example 1

In the preparation of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of comparative example 1 was obtained in the same manner except that a compound represented by the formula (c1) described in jp-a-4-226162 was used in place of the compound represented by the formula (16).

Comparative example 2

In the preparation of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of comparative example 2 was obtained in the same manner except that c.i. direct yellow 4 of the compound represented by formula (c2) was used instead of the compound represented by formula (16).

Comparative example 3

In the production of the polarized light emitting element and the polarized light emitting panel of example 1, a measurement sample of comparative example 3 was obtained in the same manner except that the compound represented by the formula (c3) was used instead of the compound represented by the formula (16).

[ evaluation ]

The measurement samples obtained in examples 1 to 5 and s1 to s5 and comparative examples 1 to 3 were used and evaluated in the following manner.

(a) Measurement of monomer transmittance Ts, parallel bit transmittance Tp, and orthogonal bit transmittance Tc

The single body transmittance Ts (%), the parallel bit transmittance Tp (%), and the orthogonal bit transmittance Tc (%) of each measurement sample were measured using a spectrophotometer ("U-4100" manufactured by Hitachi Ltd.). Here, the monomer transmittance Ts (%) is a transmittance at each wavelength when 1 measurement sample is measured. The parallel bit transmittance Tp (%) is a spectral transmittance at each wavelength measured by overlapping 2 measurement samples such that the absorption axis directions thereof are parallel to each other. The orthogonal transmittance Tc (%) is a spectral transmittance measured by superposing 2 measurement samples so that their absorption axes are orthogonal to each other. The transmittance was measured at a wavelength of 220 to 780 nm.

(b) Calculation of degree of polarization ρ

The degree of polarization ρ (%) of each measurement sample was obtained by substituting the parallel transmittance Tp and the orthogonal transmittance Tc into the following formula (i).

ρ＝{(Tp-Tc)/(Tp+Tc)}^1/2×100 (1)

(c) Calculation of the visibility-corrected monomer transmittance Ys

The visibility-corrected monomer transmittance Ys (%) of each measurement sample is a value obtained by measuring the monomer transmittance Ts in a wavelength region of 400 to 700nm in the visible light region at a specific wavelength interval d λ (here, 5nm) in accordance with JIS Z8722: 2009 transmittance obtained by visibility correction. Specifically, the monomer transmittance Ts is substituted for the formula (II) and the visibility-corrected monomer transmittance Ys is calculated. In the following formula (II), P λ represents the spectral distribution of the standard light (C light source), and y λ represents the 2-degree visual field color matching function.

(d) Measurement of polarization of luminescence

The light source was a 375nm handheld black light (PW-UV 943H-04, manufactured by Nissan chemical industries, Inc.) using an ultraviolet LED, and an ultraviolet-transmitting and visible light-cutting filter (IUV-340, manufactured by Wuling Kongzi Kogyo Co., Ltd.) was provided to the light source to cut off visible light. The measurement samples obtained in the examples and comparative examples were set, and the polarization of the sample light emission was measured using a spectroradiometer ("USR-40" manufactured by USHIO motors), and at this time, a polarizing plate having a polarizing function in the visible light region and the ultraviolet light region ("SKN-18043P" manufactured by Polatechno corporation, thickness 180 μm, Ys 43%) was set in the light receiving part of the spectroradiometer, and the polarized light emission amounts of the measurement samples obtained in the examples and comparative examples were measured. That is, the light from the light source is arranged and measured so that the light passes through the ultraviolet-transmitting and visible-light-cutting filter, the measurement sample, and the polarizing plate having polarization in the visible light region and the ultraviolet light region in this order, and is incident on the spectral radiometer. At this time, the absorption axis of the measurement sample having the maximum ultraviolet absorption and the absorption axis direction of the polarizing plate having polarization in the visible light region and the ultraviolet region ("SKN-18043P" manufactured by Polatechno corporation) were overlapped so as to be parallel, the amount of spectral emission of each wavelength measured was Lw (weak emission axis), the absorption axis of the measurement sample having the maximum ultraviolet absorption and the absorption axis direction of the polarizing plate having polarization in the visible light region and the ultraviolet region ("SKN-18043P" manufactured by Polatechno corporation) were overlapped so as to be orthogonal, and the amount of spectral emission of each wavelength measured was Ls (strong emission axis), and Lw and Ls were measured. The light energy emitted in the visible light region when the absorption axis of the test sample is parallel to or orthogonal to the absorption axis of a general polarizing plate was confirmed, and the polarized light emission in the visible light region of 400 to 700nm was evaluated based on this.

(e) Light resistance test

The light resistance test was carried out by irradiating SX-75 manufactured by Suga tester with light at an irradiation intensity of 60W, an ambient temperature of 50 ℃ and a relative humidity of 30% RH for 500 hours. Changes in Ls and Lw at each wavelength were observed.

Table 1 shows the wavelength showing the maximum polarization degree, the monomer transmittance Ts (%) at the wavelength showing the maximum polarization degree, the parallel bit transmittance Tp (%), the orthogonal bit transmittance Tc (%), and the polarization degree ρ (%), the visibility-corrected monomer transmittance Ys (%), and the visibility-corrected polarization degree ρ y (%) of each of the measurement samples obtained in examples 1 to 5 and s1 to s5 and comparative examples 1 to 3.

[ Table 1]

Table 2 below shows Ls and Lw at each wavelength of each measurement sample obtained in examples 1 to 5 and s1 to s5 and comparative examples 1 to 3.

[ Table 2]

Table 3 below shows Ls and Lw at each wavelength after the light resistance test of each of the measurement samples obtained in examples 1 to 5 and s1 to s5 and comparative example 1.

[ Table 3]

As shown in table 1, it is understood that the measurement samples of examples 1 to 5 and s1 to s5 and comparative example 1 have absorption in the ultraviolet region to the near-ultraviolet visible region, and function as a polarized light emitting panel in this region. On the other hand, it is found that the transmittance in the visible light region (visibility-corrected transmittance Ys) is 90% or more, and that the polarizing function is provided in the ultraviolet region to the near-ultraviolet visible light region, and the visible transparency is high. On the other hand, in comparative examples 2 and 3, the wavelength at which the maximum polarization degree is exhibited is 400nm or more, the visibility-corrected transmittance Ys is reduced, and the visible transmittance is observed to be reduced.

As shown in table 2, since Lw and Ls were detected in examples 1 to 5 and s1 to s5 and comparative example 1, it was found that these samples were polarized by irradiation with ultraviolet rays. On the other hand, in examples 1 to 5 and s1 to s5, the maximum light emission luminance was higher, or higher polarized light was emitted in the broad band of 400 to 700nm, as compared with comparative example 1.

In addition, as shown in table 3, examples 1 and s1 to s3 have high light resistance as compared to comparative example 1. Therefore, the polarized light emitting element and the polarized light emitting panel using the same of the present invention function not only as a polarized light emitting element that emits polarized light in the visible light region by irradiation with ultraviolet light, but also have high light resistance.

(f) Durability test

The polarized light emitting panels obtained in examples 1 to 5 and s1 to s5 were left to stand in an environment of 105 ℃ for 1000 hours and in an environment of 60 ℃ and 90% relative humidity for 1000 hours, and a durability test was conducted, at which a decrease in the degree of polarization and a change in the light emission of the polarized light were not observed. In this regard, the polarized light emitting elements and the polarized light emitting panels of examples 1 to 5 and s1 to s5 have high durability even under severe environments.

[ industrial applicability ]

When the luminescent compound of the present invention is contained in a substrate and used, a polarized light emitting element and a polarized light emitting panel which have high polarization degree at absorption wavelengths and exhibit polarized light emission can be obtained. In addition, the polarized light emitting element and the polarized light emitting panel have excellent durability and high transmittance in the visible light range. Therefore, a display device including the polarized light emitting element or the polarized light emitting panel of the present invention has high transparency in the visible light region, and can display an image by polarized light emission for a long period of time, and thus can be applied to a wide range of uses such as televisions, personal computers, tablet terminals, and transparent displays (see-through displays). In addition, the polarized light emitting element and the polarized light emitting panel containing the light emitting compound of the present invention can emit light by light in the ultraviolet region to near ultraviolet visible region, for example, 300 to 430nm, and thus can be applied to displays or media requiring high safety.

Claims

1. A luminescent compound represented by the following formula (1) or a salt thereof,

in the formula (1), at least one of X and Y (which may be independent of each other) is selected from the group consisting of a nitro group, an amino group which may have a substituent, an amide group which may have a substituent, an alkyl group having C1 to 4 which may have a substituent, an alkoxy group having C1 to 4 which may have a substituent, an aromatic group which may have a substituent, and a heterocyclic group which may have a substituent, and when X or Y is not the above selected group, X or Y is selected from an arbitrary substituent, M each independently represents a hydrogen atom, a metal ion, or an ammonium ion, M each independently represents an integer of 0 to 2, and s is 0 or 1.

2. The light-emitting compound or a salt thereof according to claim 1, wherein at least one of X and Y in the formula (1) (both independently of each other) is selected from the group consisting of substituents represented by the following formulae (2) to (8),

in the formula (2), R represents a hydrogen atom, an alkyl group having C1 to 4, an alkyl group having a sulfo group having C1 to 4, or a substituent selected from the group consisting of substituents represented by the formulae (3) to (7), in the formulae (3) and (4), A is independently selected from the group consisting of a hydrogen atom, a halogen group, a nitro group, a hydroxyl group, an alkyl group having C1 to 4, an alkoxy group having C1 to 4, an alkyl group having a sulfo group having C1 to 4, an alkyl group having a hydroxyl group having C1 to 4, an alkyl group having a carboxyl group having C1 to 4, an alkoxy group having a sulfo group having C1 to 4, an alkoxy group having a hydroxyl group having C1 to 4, and an alkoxy group having a carboxyl group having C1 to 4, and q is¹Represents an integer of 0 to 4, M in the above formulae (3) to (7) is as defined in the above formula (1), and n in the above formulae (3) and (4)¹N in the above formulae (5) to (7)²Each independently represents an integer of 0 to 3, t in the formula (8) is 0 or 1, Z represents a group selected from the group consisting of an amino group which may have a substituent, a phenyl group which may have a substituent, a naphthyl group which may have a substituent, a benzoyl group which may have a substituent, a heterocyclic group which may have a substituent, and a stilbene group which may have a substituent, and each represents a bonding position of X or Y in the formula (1).

3. The light-emitting compound according to claim 1 or 2, wherein X and Y in the formula (1) are each independently a nitro group, an amino group which may have a substituent, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aromatic group which may have a substituent, a heterocyclic group which may have a substituent, or a group selected from the group of substituents represented by the formulae (2) to (8), or a salt thereof.

4. The light-emitting compound or a salt thereof according to claim 1 or 2, wherein X and Y in the formula (1) are each independently selected from the group consisting of substituents represented by formulae (2) to (8), and when at least any one of X and Y is represented by formula (8), Z in formula (8) is any one selected from the group consisting of substituents represented by formulae (2) to (7) (wherein X represents a bonding position of Z in formula (8)).

5. The light-emitting compound or a salt thereof according to claim 1 or 2, wherein one of X and Y in the formula (1) is a nitro group or an amino group which may have a substituent, the other is selected from the group consisting of substituents represented by the formulae (2) to (8), and when the substituent represented by the formula (8) is selected, Z in the formula (8) is selected from the group consisting of substituents represented by the formulae (2) to (7).

6. The light-emitting compound or a salt thereof according to claim 1 or 2, wherein any one of X and Y in the formula (1) is a nitro group or an amino group that may have a substituent, wherein any one of X and Y is a substituent represented by the formula (8), and wherein Z in the formula (8) is a nitro group or an amino group that may have a substituent.

7. The light-emitting compound or a salt thereof according to claim 1 or 2, wherein X and Y in the formula (1) are each a nitro group or an amino group which may have a substituent.

8. The light-emitting compound or a salt thereof according to claim 1 or 2, wherein X and Y in the formula (1) are each selected from the group consisting of substituents represented by formulae (2) to (8), and when a substituent represented by formula (8) is selected, Z in the formula (8) is selected from the group consisting of substituents represented by formulae (2) to (7).

9. The light-emitting compound according to any one of claims 1 to 8, or a salt thereof, wherein s is 0.

10. The light-emitting compound according to any one of claims 1 to 8, or a salt thereof, wherein s is 1.

11. A polarized light-emitting element having a polarized light-emitting function and comprising the light-emitting compound according to any one of claims 1 to 10 or a salt thereof.

12. The polarized light emitting element according to claim 11, further comprising 1 or more organic dyes or fluorescent dyes other than the light emitting compound or a salt thereof.

13. The polarized light emitting element according to claim 11 or 12, further comprising a substrate.

14. The polarized light emitting element according to claim 13, wherein the substrate is a film containing a polyvinyl alcohol resin or a derivative thereof.

15. A polarized light emitting panel comprising the polarized light emitting element according to any one of claims 11 to 14 and a transparent protective film on at least one surface thereof.

16. A display device provided with the polarized light emitting element according to any one of claims 11 to 14 or the polarized light emitting panel according to claim 15.