JPH11185959A - Styryl compound and manufacture thereof and electroluminescent element employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroluminescent element which takes color to a wavelength of blue color part to blue green color part, excels in color taking characteristic and light emitting luminance, and excels in the durability so that a dark spot is not observed visually by containing at least one compound containing at least one unit having a specific structure. SOLUTION: This electroluminescent element contains at least one compound containing at least one unit expressed by the formula (where, X<1> denotes an oxygen atom, a sulfur atom or > NR<6> group, R<1> denotes an aromatic group or an alkenyl group, each of R<2> to R<6> denotes a hydrogen atom or a substituent, at least one of R<2> to R<5> denotes an aromatic group, and each of R<a> and R<b> denotes a hydrogen atom or a substituent). In this case, it contains at least one high molecular weight compound in which R<3> is an aromatic group, R<a> and R<b> are each hydrogen atom, R<4> is an aromatic group, R<1> is an aryl group, an aromatic group present in R<2> to R<5> is an aryl group and which has a skeleton expressed by the equation in a main chain.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a styryl compound, a method for producing the same, and an electroluminescence (EL) device containing the same.

[0002]

2. Description of the Related Art At present, research and development on various display elements are active. Among them, an organic EL element is capable of obtaining high-luminance light emission at a low voltage, and is attracting attention as a promising display element. For example, an EL element which forms an organic thin film by vapor deposition of an organic compound is known (Applied Physics Letters, vol. 51, paragraph 913, 1987).
Year). The organic EL device described in this document has a laminated structure of an electron transporting material and a hole transporting material, and its luminous characteristics are greatly improved as compared with a conventional single-layer type device.

[0003] As a means for improving the luminous efficiency of the stacked EL device, a method of doping a fluorescent dye is known. For example, Journal of Applied Physics 6
The organic EL device doped with a coumarin dye described in Vol. 5, No. 3610, 1989 has significantly improved luminous efficiency as compared with a device not doped.

In an organic EL device, the required emission color differs depending on the application, but light of a desired wavelength can be extracted by changing the type of fluorescent dye used. However, the number of fluorescent dyes that emit light with high efficiency at a desired wavelength and emit light in the blue to blue-green portion, which is excellent in durability, is small, and development thereof has been desired.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide
An object of the present invention is to provide a compound which emits light at a wavelength of a blue-green portion and has excellent durability, a method for producing the same, and an electroluminescent element containing the compound.

[0006]

The object of the present invention is achieved by the following. An electroluminescent device containing at least one compound containing at least one unit represented by the general formula (1).

[0007]

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(Wherein X ¹ represents an oxygen atom, a sulfur atom, or a> NR ⁶ group. R ¹ represents an aromatic group or an alkenyl group, and R ^{2 to} R ⁶ represent a hydrogen atom or a substituent. Represent.
However, at least one of R ^{2 to} R ⁵ represents an aromatic group. ^Ra and ^Rb represent a hydrogen atom or a substituent. ^{3. The} electroluminescent device according to claim 1, wherein R ^{3 in the} unit represented by the general formula (1) is an aromatic group, and R ^a and R ^b are hydrogen atoms. 2. The electroluminescent device according to claim 1, wherein R ^{4 of the} unit represented by the general formula (1) is an aromatic group, and R ^a and R ^b are hydrogen atoms. 2. The electroluminescent device according to claim ¹ , wherein R ¹ is an aryl group. 2. The electroluminescent device according to claim 1, wherein the aromatic group present in R ^{2 to} R ⁵ in the general formula (1) is an aryl group. A high molecular weight compound having a skeleton represented by the general formula (1) in the main chain. In the step of producing a compound containing at least one unit represented by the general formula (1), a boric acid derivative, a borate ester derivative and an aryl halide derivative or an aryl triflate derivative are added in the presence of a palladium catalyst. How to get a ring. An electroluminescent device according to any one of the above, wherein at least one high molecular weight compound having a skeleton represented by the general formula (1) in the main chain is contained.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A compound containing at least one unit represented by the general formula (1) will be described in detail.
X ¹ represents an oxygen atom, a sulfur atom or a> NR ⁶ group. The R ⁶ group represents a hydrogen atom or a substituent, and examples of the substituent include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms. Methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl,
Cyclopropyl, cyclopentyl, cyclohexyl and the like can be mentioned. ), An alkenyl group (preferably having 2 carbon atoms)
-20, more preferably 2-12 carbon atoms, particularly preferably 2-8 carbon atoms, for example, vinyl, allyl, 2-butenyl, 3-pentenyl and the like. ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms, such as propargyl and 3-pentynyl), and an aryl group (preferably). Has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 30 carbon atoms.
12, for example, phenyl, p-methylphenyl, naphthyl and the like. ), A substituted carbonyl group (preferably having 1 to 40 carbon atoms, more preferably having 1 to 2 carbon atoms)
0, particularly preferably 1 to 12 carbon atoms, for example, acetyl, benzoyl, methoxycarbonyl, dimethylaminocarbonyl, phenylaminocarbonyl and the like. ), Substituted sulfonyl groups (preferably having 1 to carbon atoms)
20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl. ), A heterocyclic group (preferably having 1 to 2 carbon atoms)
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and the hetero atom is a nitrogen atom, oxygen atom or sulfur atom, for example, imidazolyl, pyridyl,
Frills, piperidyl and the like. ). These substituents may be further substituted. R ⁶ is preferably a hydrogen atom, an alkyl group or an aryl group, and particularly preferably a hydrogen atom or an alkyl group. X
¹ is preferably an oxygen atom or a sulfur atom, and particularly preferably an oxygen atom.

R ¹ represents an aromatic group or an alkenyl group. As the aromatic group, an aryl group (preferably having 6 to 50 carbon atoms, more preferably having 6 to 30 carbon atoms, and particularly preferably having 6 to 12 carbon atoms, such as a phenyl group, a naphthyl group, and an anthracenyl group, is exemplified. ), An aromatic heterocyclic group (preferably having 1 to 50 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 2 to 12 carbon atoms, and the hetero atom is a nitrogen atom, an oxygen atom, or a sulfur atom. , A pyridyl group, a quinolyl group, a thiophene group, a carbazolyl group, an oxadiazolyl group, etc.), and these groups may be further substituted.
The alkenyl group preferably has 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl. May be further substituted.

R ¹ is preferably a substituted or unsubstituted aromatic group, particularly preferably a substituted or unsubstituted aryl group, more preferably a substituted or unsubstituted phenyl group.

The groups R ^{2 to} R ⁵ represent a hydrogen atom or a substituent, and at least one of the groups R ^{2 to} R ⁵ is an aromatic group. Examples of the aromatic group and the preferred range are the same as those of the aromatic group described for R ¹ . Examples of the substituent include, for example, an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms,
For example, methyl, ethyl, iso-propyl, tert-
Butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like. ), An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms, for example, vinyl, allyl,
-Butenyl, 3-pentenyl and the like. ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms, such as propargyl and 3-pentynyl), and an aryl group (preferably). Has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 carbon atoms.
-12, for example, phenyl, p-methylphenyl,
Naphthyl and the like. ), A substituted carbonyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably having 1 to 12 carbon atoms, such as acetyl, benzoyl, methoxycarbonyl, phenyloxycarbonyl, dimethylaminocarbonyl, and phenylaminocarbonyl. ), A substituted amino group (preferably having 1 to 20 carbon atoms, more preferably having 1 carbon atom)
To 16, particularly preferably 1 to 12 carbon atoms, such as dimethylamino, methylcarbamoyl, ethylsulfonylamino, dimethylaminocarbonylamino, and phthalimide. ), A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl. ), A sulfo group, a carboxyl group, and a heterocyclic group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 1 carbon atoms).
12, and as a hetero atom, a nitrogen atom, an oxygen atom,
Sulfur atoms such as imidazolyl, pyridyl, furyl, piperidyl, morpholino, benzoxazolyl, and triazolyl groups. ), A hydroxy group, an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include a methoxy group and a benzyloxy group). Aryloxy group (preferably having 6 to 2 carbon atoms)
It has 0, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenoxy group and a naphthyloxy group. ), A halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a thiol group, an alkylthio group (preferably having 1 to 2 carbon atoms).
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and the like, an arylthio group (preferably 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms). Particularly preferably having 6 carbon atoms
-12, such as a phenylthio group), and a cyano group. These substituents may be further substituted.

R ² and R ⁵ are preferably a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a halogen atom, or an alkoxy group, particularly preferably a hydrogen atom or an aryl group, and more preferably a hydrogen atom. .

R ³ and R ⁴ are preferably a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a halogen atom or an alkoxy group, and particularly preferably a hydrogen atom, an aryl group or an aromatic heterocyclic group. More preferably, they are a hydrogen atom and a phenyl group.

R ^a and R ^b each represent a hydrogen atom or a substituent;
As the substituent, for example, an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methyl, ethyl, is
o-propyl, tert-butyl, n-octyl, n-
Decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like can be mentioned. ), An aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 20 carbon atoms, particularly preferably having 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, and naphthyl), and hetero. Ring group (preferably having 1 to 2 carbon atoms)
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and the hetero atom is a nitrogen atom, oxygen atom or sulfur atom, for example, imidazolyl, pyridyl,
Frills, piperidyl and the like. ) And a cyano group. R ^a and R ^b are preferably hydrogen atoms.

The compound containing at least one unit represented by the general formula (1) may be a low molecular weight compound, or a compound having a residue represented by the general formula (1) connected to the polymer main chain. A molecular weight compound (preferably a weight average molecular weight of 1,000 to
5,000,000, particularly preferably 5000 to 20,000
00, more preferably 10,000 to 1,000,000)
Alternatively, a high molecular weight compound having a skeleton of the general formula (1) in the main chain (preferably a weight average molecular weight of 1,000 to 50,000)
00, particularly preferably 5000 to 2,000,000, and more preferably 10,000 to 1,000,000). In the case of a high molecular weight compound, it may be a homopolymer or a copolymer with another monomer.
As the compound represented by the general formula (1),
A low molecular weight compound or a high molecular weight compound having a skeleton represented by the general formula (1) in the main chain, more preferably a conjugated high molecular weight compound having a skeleton represented by the general formula (1) in the main chain It is.

Examples of the compound represented by formula (1) are shown below, but the invention is not limited thereto.

[0018]

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[0019]

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[0020]

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[0021]

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Next, a method for producing a compound containing at least one unit represented by the general formula (1) will be described. The compound containing at least one unit represented by the general formula (1) can be synthesized by various methods, for example, a method of homo-coupling an aryl halide in the presence of a nickel or copper derivative, an aryl halide derivative and vinylbenzene Production methods including a step using a technique of coupling the derivative in the presence of a palladium catalyst include a step of coupling a boric acid derivative or a borate ester derivative with an aryl halide derivative or an aryl triflate derivative in the presence of a palladium catalyst. Manufacturing methods are preferred. A technique using a boric acid derivative and an aryl halide derivative is more preferable. Examples of the boric acid derivative include substituted or unsubstituted arylboric acid derivatives (for example, phenylboric acid, p-fluorophenylboric acid, 1,4-phenyldiboric acid, 4,4'-biphenyldiboric acid, naphthylboric acid, and the like). ), A heteroaryl boric acid derivative (for example, pyridyl boric acid, etc.), a compound having a boric acid group at R ^{2 to} R ⁵ in the general formula (1), and the like. Examples of the borate derivative include substituted or unsubstituted arylborate derivatives (for example, pinacol phenylborate), heteroarylborate derivatives (for example, pinacol pyridylborate), and R ^{2 to} R of the general formula (1). ^And a compound having a boric acid ester group as No. ⁵ .

The halogen atom in the aryl halide derivative is preferably a chlorine, bromine or iodine atom, particularly preferably a bromine atom. Examples of the aryl halide derivative include compounds having a group in which at least one of R ^{2 to} R ⁵ has a halogen atom (for example, a bromine atom or a bromophenyl group) in the general formula (1), bromobenzene, dibromobenzene, dibromobiphenyl And the like. Examples of the aryl triflate derivative include compounds having a group in which at least one of R ^{2 to} R ⁵ has a trifluoromethanesulfonyl group (eg, a trifluoromethanesulfonyl group, a trifluoromethanesulfonylphenyl group, etc.) in the general formula (1), Sulfonylbenzene, ditrifluoromethanesulfonylbenzene and the like can be mentioned.

The palladium catalyst is not particularly restricted but includes, for example, palladium tetrakistriphenylphosphine, palladium carbon, palladium dichloride (dppf) and the like. A ligand such as triphenylphosphine may be added at the same time.

In this reaction, it is preferable to use a base.
The type of the base used is not particularly limited, and examples thereof include sodium carbonate, sodium acetate, and triethylamine. The amount of the base used is not particularly limited, but is preferably 0.1 to 20 equivalents, particularly preferably 1 to 10 equivalents, to the boric acid (ester) site. Here, 1 equivalent means that the number of moles of the boric acid (ester) group is equal to the number of moles of the base used.

In this reaction, it is preferable to use a solvent. The solvent used is not particularly limited, for example, ethanol, water,
Ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethylformamide, toluene and a mixed solvent thereof can be used.

Next, an EL device containing the styryl compound of the present invention will be described. The method for forming the organic layer of the EL device containing the styryl compound of the present invention is not particularly limited, but methods such as resistance heating evaporation, electron beam, sputtering, molecular lamination, and coating are used. In terms of surface and production, resistance heating evaporation and coating are preferred.

The light-emitting device of the present invention is a device in which a light-emitting layer or a plurality of organic compound thin films including the light-emitting layer is formed between a pair of anode and cathode electrodes. , An electron injection layer, an electron transport layer, a protective layer, and the like, and each of these layers may have another function. Various materials can be used for forming each layer.

The anode supplies holes to the hole injection layer, the hole transport layer, the light emitting layer, and the like. A metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof is used. It is possible to use a material having a work function of 4 eV or more. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO), or metals such as gold, silver, chromium, and nickel, and furthermore, these metals and conductive metal oxides. Mixtures or laminates, inorganic conductive substances such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO, and the like. Oxides,
In particular, ITO is preferable in terms of productivity, high conductivity, transparency, and the like. The thickness of the anode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm to 500 nm.

As the anode, a layer formed on a soda lime glass, an alkali-free glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass in order to reduce ions eluted from the glass. Further, when soda lime glass is used, it is preferable to use a glass coated with a barrier coat such as silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength. When glass is used, the thickness is usually 0.2 mm or more, preferably 0.7 mm or more. Various methods are used for producing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating evaporation method, a chemical reaction method (such as a sol-gel method), and a coating of a dispersion of indium tin oxide are used. The film is formed by the method described above. The anode can be cleaned or otherwise treated to lower the device's drive voltage,
It is also possible to increase the luminous efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment and the like are effective.

The cathode supplies electrons to the electron injection layer, the electron transport layer, the light-emitting layer, and the like. The cathode has good adhesion, ionization potential, and the like between the negative electrode such as the electron injection layer, the electron transport layer, and the light-emitting layer. It is selected in consideration of stability and the like. As a material for the cathode, a metal, an alloy, a metal halide, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples thereof include an alkali metal (for example, L
i, Na, K, etc.) and their fluorides, alkaline earth metals (eg, Mg, Ca, etc.) and their fluorides, gold, silver,
Lead, aluminum, a sodium-potassium alloy or a mixed metal thereof, a lithium-aluminum alloy or a mixed metal thereof, a magnesium-silver alloy or a mixed metal thereof, indium, rare earth metals such as ytterbium and the like, preferably a work function Is a material of 4 eV or less, more preferably aluminum, lithium-aluminum alloy or a mixed metal thereof, magnesium-
It is a silver alloy or a mixed metal thereof. The cathode can have not only a single-layer structure of the compound and the mixture, but also a stacked structure including the compound and the mixture. The thickness of the cathode can be appropriately selected depending on the material, but is usually from 10 nm to
It is preferably in the range of 5 μm, more preferably 50 n
m to 1 μm, more preferably 100 nm to 1 μm
It is. A method such as an electron beam method, a sputtering method, a resistance heating evaporation method, or a coating method is used for manufacturing the cathode, and a metal can be evaporated alone or two or more components can be simultaneously evaporated. Further, an alloy electrode can be formed by depositing a plurality of metals at the same time, or an alloy prepared in advance may be deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

The material of the light emitting layer is capable of injecting holes from an anode or a hole injection layer or a hole transport layer and applying electrons from a cathode or an electron injection layer or an electron transport layer when an electric field is applied. Any material can be used as long as it can form a layer having a function, a function of transferring injected charges, and a function of providing a field of recombination of holes and electrons to emit light. Preferably, the light emitting layer contains the styryl compound of the present invention, but other light emitting materials can also be used. For example, benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, perylene derivatives,
Perinone derivatives, oxadiazole derivatives, aldazine derivatives, pyrazine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styrylamine derivatives, aromatic dimethylidyne compounds, 8 And polymer compounds such as polythiophene, polyphenylene, and polyphenylenevinylene, and various metal complexes represented by metal complexes of quinolinol derivatives and rare earth complexes. Although the thickness of the light emitting layer is not particularly limited, it is usually 1 nm to 5 nm.
It is preferably in the range of μm, more preferably 5 nm to
It is 1 μm, and more preferably 10 nm to 500 nm. The method for forming the light-emitting layer is not particularly limited, but a method such as resistance heating evaporation, electron beam, sputtering, molecular lamination, coating (spin coating, casting, dip coating, etc.), and LB method And preferably a resistance heating evaporation and coating method.

The material of the hole injection layer and the hole transport layer has one of a function of injecting holes from the anode, a function of transporting holes, and a function of blocking electrons injected from the cathode. Should be fine. Specific examples thereof include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, and styryl anthracene derivatives , Fluorenone derivative, hydrazone derivative, stilbene derivative, silazane derivative, aromatic tertiary amine compound, styrylamine compound, aromatic dimethylidin compound, porphyrin compound, polysilane compound,
Examples thereof include poly (N-vinylcarbazole) derivatives, aniline-based copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, and the styryl compound of the present invention. The thickness of the hole injection layer and the hole transport layer is not particularly limited, but is usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. . The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. As a method for forming the hole injection layer and the hole transport layer, a vacuum evaporation method or L
Method B, a method of dissolving or dispersing the hole injecting and transporting agent in a solvent and coating (eg, spin coating, casting, dip coating, etc.) is used. In the case of the coating method, it can be dissolved or dispersed together with the resin component. Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N -Vinyl carbazole), hydrocarbon resins, ketone resins, phenoxy resins, polyamides, ethyl cellulose, vinyl acetate, ABS resins, polyurethanes, melamine resins, unsaturated polyester resins, alkyd resins, epoxy resins, silicone resins, and the like.

The material of the electron injecting layer and the electron transporting layer is not limited as long as it has a function of injecting electrons from the cathode, a function of transporting electrons, and a function of blocking holes injected from the anode. Good. Specific examples thereof include triazole derivatives, oxazole derivatives, oxadiazole derivatives,
Heterocyclic tetracarboxylic anhydrides such as fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene perylene, and phthalocyanine derivatives And metal complexes of 8-quinolinol derivatives, metal phthalocyanines, metal complexes having benzoxazole or benzothiazole as ligands, and styryl compounds of the present invention. The thickness of the electron injection layer and the electron transport layer is not particularly limited, but is preferably in the range of 1 nm to 5 μm.
It is more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-mentioned materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. Examples of the method for forming the electron injection layer and the electron transport layer include a vacuum deposition method, an LB method, and a method in which the electron injection and transport agent is dissolved or dispersed in a solvent and coated (spin coating, casting, dip coating, and the like). Is used. In the case of the coating method,
It can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified for the hole injection / transport layer can be applied.

As the material of the protective layer, any material may be used as long as it has a function of preventing the element which promotes the element deterioration such as moisture and oxygen from entering the element. As a specific example,
In, Sn, Pb, Au, Cu, Ag, Al, Ti, N
metal such as i, MgO, SiO, SiO ₂ , Al ₂ O ₃ , G
eO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O 3, T
metal oxides such as iO ₂ , MgF ₂ , LiF, AlF ₃ , C
aF ₂ metal fluorides such as, polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, poly-dichloro-difluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, At least one with tetrafluoroethylene
A copolymer obtained by copolymerizing a monomer mixture containing a kind of comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0.1% The following moisture-proof substances are listed. There is no particular limitation on the method of forming the protective layer, for example, a vacuum evaporation method,
Sputtering method, reactive sputtering method, MBE
(Molecular beam epitaxy) method, cluster ion beam method,
An ion plating method, a plasma polymerization method (high frequency excitation ion plating method), a plasma CVD method, a laser CVD method, a thermal CVD method, and a gas source CVD method can be applied.

[0036]

EXAMPLES Specific examples of the present invention will be described below, but the embodiments of the present invention are not limited to these examples. Synthesis of (1-1) Benzoxazole derivative 1 (7.6 g) and formylaniline derivative 2 (10 g) were mixed with ethylene glycol 50 m
of potassium-t-butoxide 4.1.
g was added. The solution was stirred for 8 hours while heating under reflux, then cooled to room temperature, 150 ml of isopropanol was added, and the precipitated solid was filtered. Crystallize the elementary crystals with ethyl acetate,
5.2 g of a yellow solid (1-1) was obtained. Synthesis of (1-7) Dibromo derivative 3 (0.38 g) and 4,4′-biphenyldibolic acid 4 (0.2 g) were added to diethylene glycol dimethyl ether 6 ml, water 2.5 ml, triphenylphosphine 0.03 g, sodium carbonate 0.5
g and 0.1 g of palladium carbon were added, and the solution was stirred for 12 hours while heating under reflux. The precipitated solid was filtered off and methanol was added to the solution washed with chloroform to obtain 0.1 g of a yellow solid (1-7). Synthesis of (1-13) To dibromo derivative 5 (0.77 g) and 4,4'-biphenyldibolic acid 4 (0.2 g) were added 6 ml of diethylene glycol dimethyl ether, 2.5 ml of water, 0.03 g of triphenylphosphine, and sodium carbonate. 0.5
g and 0.1 g of palladium carbon were added, and the solution was stirred for 12 hours while heating under reflux. 100 ml of ethyl acetate and 50 ml of aqueous hydrochloric acid (1N) were added, and the separated organic layer was washed with water and saturated saline, and then the organic layer was concentrated. Purification by column chromatography (ethyl acetate) gave yellow crystals (1-
13) 0.3 g was obtained.

[0037]

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[Preparation and Evaluation of EL Element] (Comparative Example) Polyvinylcarbazole 40 mg, PBD
12 mg of (pt-butylphenylbiphenyloxadiazole) and 1 mg of tetraphenylbutadiene were dissolved in 3 ml of dichloroethane, and spin-coated on a washed ITO substrate. The thickness of the formed organic thin film is about 120
nm. A mask (a mask having a light emitting area of 5 mm × 5 mm) patterned on the organic thin film is installed,
After co-depositing 50 nm of magnesium: silver = 10: 1 in a vapor deposition apparatus, 50 nm of silver was vapor deposited. Using a source measure unit 2400 manufactured by Toyo Technica, a DC constant voltage is applied to the EL element to emit light, and the luminance is measured using a luminance meter BM-8 manufactured by Topcon Corporation, and the emission wavelength is measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. Measured. As a result, the maximum luminance was 280 cd / m ² at 12 V.
Λmax of light emission was 450 nm. When the produced device was allowed to emit light after standing for 5 hours, a dark spot was visually observed on the light emitting surface. The occurrence of a dark spot on the light emitting surface means that the device has deteriorated.

(Examples 1 to 6) The results shown in Table 1 were obtained by using the styryl compound of the present invention instead of the tetraphenylbutadiene of the comparative example.

[0040]

[Table 1]

Example 7 Polyvinylcarbazole 40
mg and (1-3) were dissolved in 3 ml of dichloroethane and spin-coated on a washed ITO substrate. The thickness of the generated organic thin film was about 110 nm. After setting a mask patterned on the organic thin film and co-depositing 50 nm of magnesium: silver = 10: 1 in a vapor deposition apparatus,
50 nm of silver was deposited. When a voltage of 15 V was applied to the device, uniform blue-green light emission was obtained, and no dark spot was observed.

Example 8 A washed ITO substrate was placed in a vapor deposition apparatus, and TPD (N, N'-diphenyl-di (m-tolyl) benzidine was vapor-deposited to a thickness of 40 nm. Then, the compound (1-1) of the present invention was prepared. 10 nm was deposited, and TAZ (1
-Phenyl-2 (t-butylphenyl) -5-biphenyl-1,3,4-triazole) was deposited to a thickness of 20 nm, and Alq3 (Al-oxine) was deposited thereon to a thickness of 30 nm. Then, magnesium: silver = 10: 1 in a vapor deposition apparatus.
Was co-evaporated to 50 nm, and then 50 nm of silver was evaporated. When a voltage of 8 V was applied to the element, uniform blue light emission was obtained and no dark spot was observed.

The use of the styryl compound of the present invention makes it possible to produce a blue to blue-green light emitting EL device which emits light at a desired wavelength, and has excellent light emission luminance and excellent durability such that dark spots are not visually observed. Was.

[0044]

The styryl compound of the present invention develops a color in the wavelength range from blue to blue-green, and has excellent color-developing properties and durability. Therefore, the organic electroluminescent device using the same has improved light-emitting properties and durability. Are better.

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[Procedure amendment]

[Submission date] April 9, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

[0037]

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──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 26/06 C08F 26/06 C08L 39/04 C08L 39/04 C09K 11/06 655 C09K 11/06 655 680 680

Claims (8)

[Claims] 1. An electroluminescent device containing at least one compound containing at least one unit represented by the general formula (1). Embedded image (Wherein, X ¹ represents an oxygen atom, a sulfur atom, or a> NR ⁶ group. R ¹ represents an aromatic group or an alkenyl group,
R ^{2 to} R ⁶ represent a hydrogen atom or a substituent. However, R ² ~
At least one of R ⁵ represents an aromatic group. R ^a , R ^b
Represents a hydrogen atom or a substituent. ) 2. The electroluminescent device according to claim 1, wherein R ³ is a unit represented by the general formula (1).
Is an aromatic group, and R ^a and R ^b are hydrogen atoms. 3. The electroluminescent device according to claim 1, wherein R ⁴ is a unit represented by the general formula (1).
Is an aromatic group, and R ^a and R ^b are hydrogen atoms. 4. The electroluminescent device according to claim 1, wherein R ¹ is an aryl group. 5. The electroluminescent device according to claim 1, wherein R ² to R ² of the general formula (1)
An electroluminescent device, wherein the aromatic group present in R ⁵ is an aryl group. 6. A high molecular weight compound having a skeleton of the general formula (1) according to claim 1 in a main chain. 7. A boric acid derivative or borate ester derivative and an aryl halide derivative or an aryl triflate derivative are coupled in the presence of a palladium catalyst to form at least one unit represented by the general formula (1) according to claim 1. A method for producing a compound comprising: 8. The electroluminescent device according to claim 1, wherein the electroluminescent device contains at least one high molecular weight compound having a skeleton represented by the general formula (1) in the main chain. element.