JPH1154281A - Organic thin-film el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain superior luminescence characteristics by containment a polycarbonate resin formed of specific repeated unit, in at least one layer of a monolayered or multilayered organic compound thin film. SOLUTION: Resin is expressed with a formula, where Ar<1> ,<2> represents an aromatic bivalent group, R<1-4> represents an alkyl group or an aromatic group, R<1> and R<2> , R<3> and R<4> , R<1> and Ar<1> , R<3> and Ar<2> may form a ring with a nitrogen atom. Y<1> ,<2> represents an alkylene group, a cycloalkylene group, an alkylene ether group, or an O, S vinylene group, p<1> ,<2> =1,2, Ar<3> ,<4> represents an aromatic trivalent group, A represents an alkylene group, a cycloalkylidene group, an alkylene ether group, an O, S vinylene group, N=5-5000, X represents an alkylene group, a cycloalkylidene group, an alkylene ether group, -Ar<5> -Z-Ar<6> - (Ar<5> ,<6> represents an aromatic bivalent group, Z represents single bond, an alkylene group, a cycloalkylidene group, an alkylene ether group, an O, S, or vinylene group), the resin exhibits superior durability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel organic thin film EL.
More specifically, the present invention relates to an organic thin-film EL device made of an aromatic polycarbonate resin having excellent heat resistance, mechanical strength, and durability without change over time.

[0002]

2. Description of the Related Art In recent years, organic thin-film EL elements are self-luminous and have a high viewing angle dependency and high visibility. Further, since they are thin-film type solid-state elements, they are attracting attention from the viewpoint of space saving and the like. It has been started for practical research. However, there are many problems to be solved, such as further improvement of energy conversion efficiency and emission quantum efficiency, and provision of stability of the organic thin film over time.

Heretofore, there have been reported organic thin film EL devices using low molecules and those using polymers.
In the case of low molecular weight systems, it has been reported that high efficiency can be achieved by employing various laminated structures, and that durability can be improved by properly controlling the doping method. However, it has been reported that in the case of a low-molecular assembly, a change in the film state occurs over time over a long period of time, and there is an essential problem with respect to the stability of the film. On the other hand, in the case of polymer materials, PPV (poly-p-
phenylenevinylene) series and poly
-Thiophene and the like have been energetically studied. However, it is difficult to increase the purity of these materials, and the fluorescence quantum yield is essentially low. Therefore, at present, a high-performance EL device has not been obtained. In the case of a polymer material, considering that the glass state is essentially stable, if high fluorescence quantum efficiency can be imparted, an excellent EL device can be constructed.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned state of the art, and particularly has a charge transporting property and is excellent in heat resistance as a component constituting an organic thin film layer of a light emitting layer. It is an object of the present invention to provide an organic thin film EL element containing an aromatic polycarbonate resin, which does not change with time and has excellent durability.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an EL element having an organic layer containing a specific aromatic polycarbonate resin has excellent light emitting characteristics, and completed the present invention. I came to.

That is, according to the present invention, in an organic thin-film EL device having a light-emitting layer composed of a single layer or a plurality of organic compound thin films between an anode and a cathode facing each other, at least one layer of the organic compound thin film is provided. Is a layer containing an aromatic polycarbonate resin comprising a repeating unit represented by the following general formula (I):
An element is provided.

Embedded image [Wherein, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , A, R ¹ , R ² ,
R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ , n and X are the same as defined above, respectively. ]

Further, according to the present invention, at least one layer of the organic compound thin film of the light emitting layer contains an aromatic polycarbonate resin represented by the above general formula and an electron transporting substance, or a layer containing a light emitting substance. Wherein the organic thin film EL device is provided. According to the present invention, there is provided an organic thin-film EL device including a light-emitting layer composed of a plurality of organic compound thin films having at least one hole injection / transport layer between an anode and a cathode facing each other.
An organic thin film EL device is provided, wherein at least one of the hole injecting and transporting layers is a layer containing the aromatic polycarbonate resin represented by the general formula (I). According to the present invention, in an organic thin-film EL device including a light-emitting layer composed of a plurality of organic compound thin films between an anode and a cathode facing each other, the light-emitting layer is represented by the general formula (I). A layer containing an aromatic polycarbonate resin, at least one hole injection transport layer, and / or
Alternatively, there is provided an organic thin-film EL device comprising at least one electron injection / transport layer, or at least one hole and electron injection / transport layer.

Further, according to the present invention, the aromatic polycarbonate resin comprises a repeating unit represented by the following general formulas (II) and (III), and the composition ratio of the repeating unit is 0 <m / (m + 1) ≦ 1 is an aromatic polycarbonate resin.

Embedded image

Embedded image [Wherein, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , A, R ¹ , R ² ,
R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ , m, l and X are the same as defined above, respectively. ]

The aromatic polycarbonate resin contained in the light emitting layer of the organic thin film EL device of the present invention is a compound represented by the following general formula (I), the following general formula (II) or the following general formulas (II) and (III): It is composed of a unit, has a tertiary amine structure in a side chain, and has both hole transporting properties and fluorescent properties. Therefore, it can be used as a charge transporting polymer material or a fluorescent material in an organic thin film EL device.

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Embedded image

Embedded image [In each of the above formulas, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , A,
R ¹ , R ² , R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ , n, m, l
And X are the same as defined above. ]

The aromatic polycarbonate resin to be contained in the light emitting layer of the organic thin film EL device of the present invention can be produced by a method similar to the polymerization of bisphenol and a carbonic acid derivative, which is conventionally known as a method for producing a polycarbonate resin. That is, the aromatic polycarbonate resin comprising a repeating unit represented by the general formula (II) of the present invention comprises a diol compound having a tertiary amino group represented by the following general formula (IV), a bisaryl carbonate, Transesterification method,
It is produced by a phosgene method by solution or interfacial polymerization with phosgene, or a chloroformate method using monochloroformate or bischloroformate derived from a diol. At this time, by using a diol represented by the following general formula (V) in combination, an aromatic polyester comprising the repeating unit represented by the general formula (II) and the repeating unit represented by the general formula (III) A carbonate resin can be produced, whereby an aromatic polycarbonate resin having desired properties can be obtained. The ratio of the repeating unit having a tertiary amino group represented by the general formula (II) to the repeating unit represented by the general formula (III) can be selected from a wide range depending on desired characteristics. Further, the aromatic polycarbonate resin comprising the repeating unit represented by the general formula (I),
It can be obtained by interfacial polymerization or solution polymerization of a diol compound having a tertiary amino group represented by the following general formula (IV) and a bischloroformate derived from the general formula (V). It can also be obtained by polymerization of a bischloroformate derived from a diol compound having a tertiary amino group represented by the general formula (IV) and a diol represented by the general formula (V).

[0011]

Embedded image

Embedded image HO—X—OH (V) [In each of the formulas (IV) and (V), Ar ¹ , Ar ² , Ar ³ , A
r ⁴ , A, R ¹ , R ² , R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ ,
And X are the same as defined above. ]

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The present invention contains an aromatic polycarbonate resin comprising a repeating unit represented by the general formula (I), the general formula (II), or the general formula (II) and the general formula (III) as described above. The present invention relates to an organic thin-film EL device provided with a light-emitting layer made of an organic thin film.

The aromatic polycarbonate resin used in the present invention may be a homopolymer composed of the repeating unit represented by the general formula (II) or an alternating copolymer composed of the repeating unit represented by the general formula (I). It may be a random copolymer or a block copolymer having a repeating unit represented by formulas (II) and (III) as a constitutional unit. Further, the molecular weight of the aromatic polycarbonate resin of the present invention is 1000 in terms of polystyrene-equivalent number average molecular weight.
~ 1,000,000, preferably 2000-500000
It is.

The raw material for providing each repeating unit represented by the general formulas (I) and (II), which constitutes the aromatic polycarbonate resin used in the present invention, is represented by the general formula (IV)
In a diol compound having a tertiary amino group represented by the formula: Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , Ar ⁵ , Ar ⁶ ,
Specific examples of A, R ¹ , R ² , R ³ , R ⁴ , Y ¹ , Y ² , and X include the following.

When R ^{1 to} R ⁴ are a substituted or unsubstituted alkyl group, the alkyl group (—R ⁵ ) includes C _{1 to} C 4
_{12 is a} C ₁ -C ₉ , more preferably a C ₁ -C ₄ linear or branched alkyl group, and these alkyl groups are furthermore a fluorine atom, a hydroxyl group, a cyano group, a C ₁ -C ₄ alkoxy group , A phenyl group, or a halogen atom, C _1-
It may contain a phenyl group substituted with a C ₄ alkyl group or a C ₁ -C ₄ alkoxy group. Specifically, methyl, ethyl, n-propyl, i-propyl, t
-Butyl group, s-butyl group, n-butyl group, i-butyl group, trifluoromethyl group, 2-hydroxyethyl group,
2-cyanoethyl group, 2-ethoxyethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4
-Methylbenzyl group, 4-methoxybenzyl group, 4-phenylbenzyl group and the like.

When R ^{1 to} R ⁴ are a substituted or unsubstituted aromatic group, the aromatic group (—Ar ⁷ ) includes a carbocyclic aromatic group and a heterocyclic aromatic group. Typical examples of these include phenyl, biphenylyl, terphenylyl, petalenyl, indenyl, naphthyl, azulenyl, heptalenyl, biphenylenyl, as-indacenyl, fluorenyl, s-indacenyl, acenaphthenyl , A preadenyl group,
Fluorenyl group, s-indacenyl group, acenaphthylenyl group, preyadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrenyl group, triphenylrenyl group, Pyrenyl group, chrysenyl group and naphthacenyl group, pyridyl group, pyrazinyl group,
Triazinyl group, furyl group, pyrrolyl group, thienyl group,
Quinolyl group, coumarinyl group, benzofuranyl group, benzimidazolyl group, benzoxazolyl group, dibenzofuranyl group, benzothienyl group, dibenzothionyl group, indolyl group, carbazolyl group, pyrazolyl group, imidazolyl group, oxazolyl group, isoxazolyl group, Thiozolyl group, indazolyl group, benzothiazolyl group, pyridazinyl group, cinnolinyl group, quinazonilyl group, quinoxalyl group, phthalazinyl group, phthalazinyl group, chromonyl group, naphtholactonyl group, quinolonyl group, imidyl o-sulfobenzoate, imidyl maleate Group, naphthalidinyl group, benzimidazolonyl group, benzoxazolonyl group, benzothiazolonyl group, benzothiazothionyl group, quinazolonyl group, quinoxalonyl group, phthalazonyl group, dioxopi Midinyl group, pyridonyl group, isoquinolyl group, isoquinolyl group, isothiazolyl group, benzisoxazolyl group, benzisothiazolyl group, indazolonyl group, acridinyl group, acrylonyl group, quinazolindionyl group, quinoxaline dionyl group, benzoxazine dithione And a benzyl group, a benzoxazinyl group and a naphthalimidyl group.

The aromatic ^{2 of} Ar ¹ , Ar ² , Ar ⁵ and Ar ⁶
Specific examples of the trivalent group and the trivalent group in which Ar ³ and Ar ⁴ are aromatic include a divalent group and a trivalent group derived from the aromatic group defined as R ^{1 to} R ⁴ .

When A, Y ¹ , Y ² , X, and Z are a substituted or unsubstituted alkylene group (—R ⁶ —), the alkylene group is an alkyl group (—R ⁶ ) as defined above for R ^{1 to} R ^{4. 5} )
And a divalent group derived from Specifically, a methylene group, an ethylene group, a 1,3-propylene group,
1,4-butylene group, 2-methyl-1,3-propylene group, difluoromethylene group, hydroxyethylene group, cyanoethylene group, methoxyethylene group, phenylmethylene group, 4-methylphenylmethylene group, 2,2-propylene Group, 2,2-butylene group, diphenylmethylene group and the like.

When A, Y ¹ , Y ² , X, and Z are substituted or unsubstituted cycloalkylidene groups, the cycloalkylidene group is a group represented by the following formula.

Embedded image [In the formula, k represents an integer of 4 to 10. Specifically, a 1,1-cyclopentylidene group, 1,1-
Examples thereof include a cyclohexylidene group and a 1,1-cyclooctylidene group.

When A, Y ¹ , Y ² , X and Z are a substituted or unsubstituted alkylene ether group, specifically, dimethylene ether group, diethylene ether group, methylene ethylene ether group, bis (triethylene) ether Group, a bis (hexamethylene) ether group and the like.

In addition, these Ar ¹ , Ar ² , Ar ³ , Ar ⁴ ,
Ar ⁵ , Ar ⁶ , A, R ¹ , R ² , R ³ , R ⁴ , Y ¹ , Y ² ,
When X and Z have substituents, examples of such substituents include the alkyl groups and aromatic groups defined for R ^{1 to} R ⁴ , and the following various groups. (1) Halogen atom: fluorine, chlorine, bromine and iodine. (2) cyano group (—CN) (3) nitro group (—NO ₂ ) (4) hydroxy group (—OH) (5) alkoxy group (—OR ⁷ ); R ⁷ is defined as R ^{1 to} R ⁴ above. It represents an alkyl group (-R ^5). Specifically, methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy, n-butoxy, s-butoxy, i-butoxy, 2-hydroxyethoxy, 2-hydroxyethoxy
Examples include a cyanoethoxy group, a benzyloxy group, a 4-methylbenzyloxy group, and a trifluoromethoxy group. (6) alkylthio group (-SR ^8); R ⁸ represents an alkyl group as defined R ¹ to R ^4. Specific examples include a methylthio group, an ethylthio group, a benzylthio group, and a hydroxyethylthio group. (7) an aryloxy group (-OAr ^8); Ar ⁸ is R ¹ ~
Represents an aromatic group (—Ar ⁷ ) defined for R ⁴ . Specific examples include a phenoxy group, a 4-methylphenoxy group, and a naphthoxy group. (8) arylthio group (—SAr ⁹ ); Ar ⁹ is R ^{1 to} R ⁴
Represents an aromatic group (—Ar ⁷ ) defined by Specific examples include a phenylthio group and a naphthylthio group. (9) Amino group [—N (R ⁹ ) (R ¹⁰ )]; R ⁹ , R ¹⁰
Are each independently an alkyl group defined as R ^{1 to} R ⁴ (-
R ⁵ ) represents an aromatic group (—Ar ⁷ ) and may form a ring together. Specifically, a diethylamino group, N-methyl-
N-phenylamino group, N, N-diphenylamino group,
Examples thereof include an N, N-di (p-tolyl) amino group, a dibenzylamino group, a piperidino group, a morpholino group, and a uroridyl group. (10) Vinyl group [group represented by the following formula]

Embedded image

Embedded image [Wherein R ¹¹ and R ¹² are (1) to (4), (7), (8)
And a group defined as the aromatic hydrocarbon group (—Ar ⁷ ),
R ¹³ and R ¹⁴ each represent a group defined by an alkylene group (—R ⁶ —), a cycloalkylidene group, or an alkylene ether group, j is an integer of 0 or 1, W is an oxygen atom, a sulfur atom, a vinylene group or Represents an alkylene group. Specifically, a styryl group, a 4-methylstyryl group, a β-methylstyryl group, a 4-chlorostyryl group, a β-phenylstyryl group, a β- (4-methylphenyl) styryl group,
4-phenyl-1,3-butadienyl group and the like can be mentioned.

Next, specific examples of the diol represented by the general formula (V) are shown below. 1,3-propanediol,
1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 2-methyl-1,3-
Propanediol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-propanediol,
Aliphatic diols such as diethylene glycol, triethylene glycol, polyethylene glycol, and polytetramethylene ether glycol, and cyclic aliphatic diols such as 1,4-cyclohexanediol, 1,3-cyclohexanediol, and cyclohexane-1,4-dimethanol are used. No.

The diol having an aromatic ring includes
4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2 -Bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-
Bis (4-hydroxyphenyl) cyclopentane, 2,
2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-isopropyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 4,4′-dihydroxydiphenylsulfone, 4,
4'-dihydroxydiphenylsulfoxide, 4,4 '
-Dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide,
4,4'-dihydroxydiphenyl oxide, 2,2-
Bis (4-hydroxyphenyl) hexafluoropropane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxyphenyl) xanthene, ethylene glycol-bis (4-hydroxybenzoate), diethylene glycol- Bis (4-hydroxybenzoate), triethylene glycol-bis (4
-Hydroxybenzoate), 1,3-bis (4-hydroxyphenyl) -tetramethyldisiloxane, phenol-modified silicone oil and the like.

The aromatic polycarbonate resin used in the present invention is, as described above, a diol compound having a tertiary amino group or the like represented by the general formula (IV) and optionally a diol compound represented by the general formula (V). And a diol compound having a tertiary amino group or the like represented by the general formula (IV) and a diol compound represented by the general formula (V) by a transesterification method or a phosgene method. With bischloroformate derived from a diol in the presence of a solvent and a deoxidizing agent.

Hereinafter, the above manufacturing method will be described in more detail. In the transesterification method, a diol compound and a bisaryl carbonate are mixed in the presence of an inert gas, and the reaction is usually performed at 120 to 350 ° C. under reduced pressure. The degree of pressure reduction is changed stepwise, and finally, the pressure is reduced to 1 mmHg or less, and phenols produced are distilled out of the system. The reaction time is usually 1 to
It is about 4 hours. Moreover, you may add a molecular weight modifier and an antioxidant as needed. As the bisaryl carbonate, diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p
-Chlorophenyl carbonate, dinaphthyl carbonate and the like.

In the phosgene method, the reaction is usually carried out in the presence of a deoxidizing agent and a solvent. As the deoxidizing agent, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, pyridine and the like are used. As the solvent, for example, a halogenated hydrocarbon such as dichloromethane or chlorobenzene is used. In order to promote the reaction, for example, a tertiary amine,
A catalyst such as a quaternary ammonium salt can be used,
Phenol, p-tert as a molecular weight regulator
It is desirable to use a terminal terminator such as -butylphenol. The reaction temperature is usually 0 to 40 ° C, and the reaction time is several minutes to
It is preferably 5 hours and the pH during the reaction is usually maintained at 10 or more.

When bischloroformate is used, it can be obtained by dissolving a diol compound in a solvent, adding a deoxidizing agent, and adding bischloroformate thereto. As the deoxidizing agent, trimethylamine, triethylamine,
Tertiary amines such as tripropylamine and pyridine are used. As the solvent used in the reaction, for example, halogenated hydrocarbons such as dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, trichloroethylene and chloroform, and cyclic ether solvents such as tetrahydrofuran and dioxane are preferable. Further, it is desirable to use a terminal terminator such as phenol or p-tert-butylphenol as the molecular weight regulator. Reaction temperature is usually 0 to 40 ° C,
The reaction time is a few minutes to 5 hours.

If necessary, additives such as an antioxidant, a light stabilizer, a heat stabilizer, a lubricant, and a plasticizer can be added to the aromatic polycarbonate resin produced according to the above method.

In the following, typical examples of the aromatic polycarbonate resin used in the present invention are shown in Tables 1 to 3 by dividing the chemical structural formula into three units in order to avoid complexity. Thereafter, aromatic polycarbonate resin No. Is represented by a combination of the respective tables. For example, aromatic polycarbonate resin No. 2-4-1 is a compound composed of the following repeating units.

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[0030]

[Table 1- (1)]

[0031]

[Table 1- (2)]

[0032]

[Table 1- (3)]

[0033]

[Table 1- (4)]

[0034]

[Table 1- (5)]

[0035]

[Table 2]

[0036]

[Table 3]

Next, the organic thin film EL device of the present invention will be described. The layer containing the above-mentioned aromatic polycarbonate resin among the organic compound thin film layers in the organic thin film EL device of the present invention can be thinned by a known method such as a spin coating method or a casting method. The aromatic polycarbonate resin is easily dissolved in an organic solvent such as dichloromethane and tetrahydrofuran. Accordingly, a thin film can be prepared by preparing a solution having an appropriate concentration with an appropriate solvent capable of dissolving the aromatic polycarbonate resin, and applying the solution by the above method or the like. When a film containing an electron transporting substance or a luminescent substance is produced, they can be produced by dissolving them together in the above aromatic polycarbonate resin solution and applying them. In addition, by utilizing the property that different polymers are hardly compatible with each other, it is also possible to prepare a film that forms another kind of polymer micro-dispersed phase in one kind of polymer medium. In this case, a mixed solution in which the combination and the mixing ratio of the resins are changed is prepared, and the mixed solution may be applied by a similar wet film forming method. In such a film, the aromatic polycarbonate resin may be used as a polymer medium or as a finely dispersed phase.

Since these membranes are usually as thin as 20 μm or less, it is preferable to use the solution before coating by filtering the solution with a filter having a pore diameter of 0.45 μm or less, more preferably 0.1 μm or less. In the case where the organic layer in the organic thin film EL device is composed of a plurality of organic compound thin film layers and has a low molecular compound layer, a dry film forming method such as vacuum evaporation or sputtering can be used other than the wet film forming method. .

The light emitting layer constituting the organic thin film EL device of the present invention may be composed of a single layer or a plurality of organic compound thin films. When the light-emitting layer is composed of a single layer, the layer may be composed of a polycarbonate resin alone, and in some cases, a dispersion of a low-molecular compound having an electron-transport property, a blend with a polymer, or another charge. Blending with a transportable polymer and doping a trace amount of a fluorescent molecule with extremely high fluorescence quantum efficiency are also effective in increasing the efficiency.

The light-emitting layer constituting the organic thin-film EL device of the present invention can further comprise a plurality of layers, if necessary. In this case, an electron injection / transport layer, another light emitting layer, and the like can be further laminated on the polycarbonate resin-containing layer by a spin coating method or a vacuum evaporation method. Forming a hole injecting and transporting layer before forming a polycarbonate resin-containing layer may also be effective in improving performance.

As the electron transporting substance, an existing material having the ability to transport electrons can be used. For example, it has been reported that fluorenone, anthraquinodimethane, diphenoquinone, thiopyrandioxide, perylenetetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane, anthrone and the like and derivatives thereof and have excellent electron transportability so far. It is possible to use the oxadiazole derivative or the triazole derivative that is used.

As the fluorescent molecule having extremely high fluorescence quantum efficiency, a laser dye or the like which exhibits strong fluorescence in a solution state or an existing low molecular fluorescent material which has been used as a light emitting material in an organic EL device is used. It is possible to For example, anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene, chrysene, fluorescein, perylene, phthaloperylene, naphthaloperylene, perinone, phthaloperinone, naphthaloperinone, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, aldazine, bisbenzoxazoline, Bisstyryl, pyrazine, cyclopentadiene, quinoline metal complex, aminoquinoline metal complex, benzoquinoline metal complex, imine, diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran, polymethine, merocyanine, imidazole quinolated oxinoid compound, quinacridone, rubrene And their derivatives.

Further, as the material constituting the hole injecting and transporting layer, phthalocyanine compounds, porphyrin compounds, oxadiazole, triazole, triphenylamine compounds which have been reported to function in organic EL devices have been reported. It is possible to use an existing material such as polysilane.

The thickness of the organic compound thin film layer formed in this manner is not particularly limited, and is usually from 5 nm to 20 nm.
It is selected in the range of μm. More preferably, from 5 nm to 0.1 nm.
The range is 2 μm. The film thickness is adjusted in consideration of the occurrence of film defects such as pinholes, light interference within the device at the emission wavelength, and an increase in applied voltage due to an increase in film thickness.

As the anode of the organic thin film EL device in the present invention, a metal, an alloy, a metal oxide or the like having a work function of 4 eV, preferably more than 4.8 eV is used. Specific examples of such an electrode material include gold, platinum, palladium, silver, tank stainless steel, nickel, cobalt, ITO,
Use of a transparent electrode such as CuI, SnO ₂ , ZnO, etc. may be mentioned. Particularly preferably, an ITO substrate is suitable. ITO
In the case of a substrate, a substrate having a smooth surface is preferable, and dirt on the surface is thoroughly washed before use. As a cleaning method, a known method may be used, but a method in which ultraviolet irradiation in an ozone atmosphere or plasma treatment in an oxygen atmosphere is performed is preferable.

On the other hand, as the cathode, a metal, an alloy or the like having a work function lower than 4 eV is used. Specific examples of such a substance include sodium, calcium, magnesium, lithium, aluminum, samarium, and alloys thereof.

When the organic thin film EL device of the present invention is used as a surface light emitting device, at least one of these electrodes is sufficiently transparent in the emission wavelength region of the device, and the other side has a sufficient reflectance in the emission wavelength region. It is desirable to be large. In the case of edge emission, it is not necessary to be transparent. As the transparent electrode, the above-mentioned ITO is preferable, and a transparent glass plate or a plastic plate is also used for the substrate.

In order to improve the stability of the obtained organic thin film EL device to the temperature, humidity and atmosphere of the environment, it is effective to provide a protective layer on the surface of the device, or to protect the entire device by enclosing silicon oil or the like. It is.

Using the thus obtained organic thin film EL device of the present invention, a positive electrode is connected to the cathode and a negative electrode is connected to the cathode, and voltage is applied, so that EL emission can be observed. Normally, in an organic thin film EL device, Joule heat is generated by energization, and the heat causes recrystallization of the organic compound thin film layer, progress of aggregation, and diffusion of a low molecular material, all of which reduce the durability of the device. Have the problem to say. In the organic thin film EL device of the present invention, since a stable aromatic polycarbonate resin having a high melting point and an amorphous state is used for the organic compound thin film layer, device deterioration due to crystallization or aggregation and device deterioration due to diffusion can be suppressed, An element having good durability can be obtained.

[0050]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Production Example 1 Under a nitrogen stream, 8.67 g (10.0 mmol) of 1,1-bis [3- (4-di-p-tolylaminophenethyl) -4-hydroxyphenyl] cyclohexane and 3.04 g of triethylamine ( 30.0 mmol) was dissolved in 50 ml of dry tetrahydrofuran, and 2.31 g (10.0 mmol) of diethylene glycol bis (chloroformate) was added thereto.
(mmol) in 10 ml of dry tetrahydrofuran was added dropwise over 30 minutes at room temperature. Subsequently, after stirring at room temperature for 3 hours, phenol 0.04 g
(0.4 mmol) dissolved in 1 ml of tetrahydrofuran was added, and the mixture was further stirred for 10 minutes. Next, the precipitated triethylamine hydrochloride was removed by filtration, the tetrahydrofuran solution of the filtrate was dropped into methanol, and the precipitated resin was separated by filtration and dried by heating under reduced pressure. Further, the operation of dissolving the obtained resin in tetrahydrofuran and precipitating it in methanol is repeated twice, followed by heating under reduced pressure and drying to obtain the desired aromatic polycarbonate resin represented by the following structural formula (No. 2-4-1). 7.9
2 g (77.3% yield) were obtained. Its Tg is 91
° C, and the number average molecular weight and weight average molecular weight (in terms of polystyrene) were 5,800 and 11,900.

Embedded image The elemental analysis values of the aromatic polycarbonate resin were as follows. C% H% N% Found 79.20 6.82 2.54 Calculated 79.66 6.69 2.73

Example 1 An ITO substrate etched into a 2 mm stripe was washed with boiling alcohol, and the surface was treated with oxygen plasma. Compound No. A 1.0 wt% dichloromethane solution of 2-4-1 aromatic polycarbonate resin was prepared and filtered with a membrane filter having a pore size of 0.1 μm. Using this solution, an organic light emitting layer having a thickness of 100 nm was formed on the ITO substrate by spin coating. After sufficiently drying, the substrate is set inside the vapor deposition apparatus, and the pressure is set to 200 through a mask at a degree of vacuum of 10 ^-4 Pa.
An MgAg alloy layer having a thickness of 10 nm was formed to produce an organic thin film EL device. The size of the light emitting surface was 2 mm × 2 mm. Using the EL element thus manufactured, ITO was connected to the anode and MgAg was connected to the cathode.
, Blue emission was observed. This organic layer did not undergo any alteration such as crystallization.

Example 2 An organic thin film EL device was manufactured in the same manner as in Example 1. However, in this case, 2- (4-biphenyly) represented by the following structural formula is further contained in a dichloromethane solution.
l) -5- (4-t-butylphenyl) -1,
3,4-oxadiazole (PBD) (A) was dissolved to a solid content of 30 wt% to form an organic light emitting layer. Using the EL element manufactured in this way, IT
When O was connected to the anode and MgAg was connected to the cathode, blue light emission was observed at an applied voltage of 10 V. This organic layer did not undergo any alteration such as crystallization.

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Example 3 An organic thin film EL device was manufactured in the same manner as in Example 1. However, in the dichloromethane solution, 2- (4-Bip
(Henylyl) -5- (4-t-butylphenyl)
yl) -1,3,4-oxadiazole (PBD)
Was dissolved in a solid content of 30 wt% and a trace amount of a perylene derivative (B) represented by the following structural formula at 3 wt% to form an organic light emitting layer. Using the EL device manufactured in this manner, when ITO was connected to the anode and MgAg was connected to the cathode, orange light emission was observed at an applied voltage of 10 V. This organic layer did not undergo any alteration such as crystallization.

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Example 4 A 50 nm film similar to that of Example 1 was formed on an ITO substrate treated in the same manner as in Example 1 by the dipping method using the same dichloromethane solution as in Example 1. After performing sufficient drying, the substrate is set inside the vapor deposition apparatus, and 10 ^-4
An Alq molecule deposited film of the compound (C) represented by the following structural formula of 50 nm was formed at a degree of vacuum of Pa, and an MgAg alloy layer of 200 nm was further formed through a mask to produce an organic thin film EL device. The size of the light emitting surface is 2mm x 2m
m. Using the EL device thus manufactured,
When ITO was connected to the anode and MgAg was connected to the cathode, green light emission was observed at an applied voltage of 10 V. This organic layer did not undergo any alteration such as crystallization.

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Example 5 An organic thin film EL device was produced in the same manner as in Example 2. However, compound N is used as a polycarbonate resin component.
o. 2-4-2 was used. EL produced in this way
When ITO was connected to the anode and MgAg was connected to the cathode, blue light emission was observed at an applied voltage of 10 V. Also,
This organic layer did not undergo any alteration such as crystallization.

Example 6 An organic thin film EL device was produced in the same manner as in Example 2. However, compound N is used as a polycarbonate resin component.
o. 2-4-3 was used. EL produced in this way
When ITO was connected to the anode and MgAg was connected to the cathode using the device, blue light emission was observed at an applied voltage of 10 V.
This organic layer did not undergo any alteration such as crystallization.

Example 7 An organic thin film EL device was manufactured in the same manner as in Example 2. However, compound N is used as a polycarbonate resin component.
o. 2-4-5 was used. EL produced in this way
When ITO was connected to the anode and MgAg was connected to the cathode using the device, blue light emission was observed at an applied voltage of 10 V.
This organic layer did not undergo any alteration such as crystallization.

Example 8 An organic thin film EL device was produced in the same manner as in Example 4. However, compound N is used as a polycarbonate resin component.
o. 2-4-2 was used. EL produced in this way
When ITO was connected to the anode and MgAg was connected to the cathode using the device, green light emission was observed at an applied voltage of 10 V.
This organic layer did not undergo any alteration such as crystallization.

Example 9 An organic thin film EL device was produced in the same manner as in Example 4. However, compound N is used as a polycarbonate resin component.
o. 2-4-3 was used. EL produced in this way
When ITO was connected to the anode and MgAg was connected to the cathode using the device, green light emission was observed at an applied voltage of 10 V.
This organic layer did not undergo any alteration such as crystallization.

Example 10 An organic thin film EL device was produced in the same manner as in Example 4. However, compound N is used as a polycarbonate resin component.
o. 2-4-5 was used. EL produced in this way
When ITO was connected to the anode and MgAg was connected to the cathode using the device, green light emission was observed at an applied voltage of 10 V.
This organic layer did not undergo any alteration such as crystallization.

Example 11 An ITO substrate etched into a 2 mm stripe was washed with boiling alcohol, and the surface was further treated with oxygen plasma. A 10 nm-thick film of copper phthalocyanine was formed thereon as a hole injection / transport layer by vacuum evaporation. On top of this, the compound No. used in Example 1 was used. 2
The organic light-emitting layer having a thickness of 90 nm was formed by spin coating using the aromatic polycarbonate resin solution of -4-1. After sufficient drying, the substrate was set inside the vapor deposition apparatus, and 200 n was passed through a mask at a degree of vacuum of 10 ^-4 Pa.
An m-MgAg alloy layer was formed to produce an organic thin-film EL device. The size of the light emitting surface was 2 mm × 2 mm. Using the EL element thus produced, ITO was used as the anode,
When MgAg was connected to the cathode, blue light emission was observed at an applied voltage of 10 V. This organic layer did not undergo any alteration such as crystallization.

Example 12 In the same manner as in Example 11, a copper phthalocyanine layer and a compound No. 1 were formed on an ITO substrate. A 2-4-1 aromatic polycarbonate layer was produced. A 50 nm Alq molecule deposited film was formed thereon by a vacuum evaporation method in the same manner as in Example 4, and a 200 nm MgAg alloy layer was further formed via a mask, to produce an organic thin film EL device. The size of the light emitting surface is 2
mm × 2 mm. Using the EL device manufactured in this manner, when ITO was connected to the anode and MgAg was connected to the cathode, green light emission was observed at an applied voltage of 10 V.
This organic layer did not undergo any alteration such as crystallization.

Example 13 A copper phthalocyanine layer was formed on an ITO substrate in the same manner as in Example 11. On top of this, the compound N used in Example 3
o. 2-4-1 Aromatic polycarbonate resin and PBD
And a perylene derivative (B) was used to form an organic light-emitting layer by spin coating. Furthermore, by vacuum evaporation method,
An electron injection / transport layer having a thickness of 30 nm of an oxadiazole compound represented by the following structural formula (D) was prepared. Further, an MgAg alloy layer having a thickness of 200 nm was formed through a mask, thereby producing an organic thin film EL device. The size of the light emitting surface is 2
mm × 2 mm. When ITO was connected to the anode and MgAg was connected to the cathode using the EL device thus manufactured, orange light emission was observed at an applied voltage of 10 V. This organic layer did not undergo any alteration such as crystallization.

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[0065]

According to the organic thin film EL device of the present invention, the organic compound thin film layer constituting the light emitting layer has the general formula (I) or the general formula (2) having a tertiary amine structure in a side chain.
Alternatively, an aromatic polycarbonate resin comprising a repeating unit represented by the general formula (2) and the general formula (3) is used, and the aromatic polycarbonate resin has a charge transporting ability and a high mechanical strength. Since it has a high melting point and a stable amorphous state, it is an organic thin film EL device having excellent durability without causing deterioration of the device due to crystallization, aggregation or diffusion.

Claims (6)

[Claims] 1. An organic thin-film EL device comprising a light-emitting layer comprising a single layer or a plurality of organic compound thin films between an anode and a cathode facing each other, wherein at least one of the organic compound thin films has the following general formula ( An organic thin film EL device comprising a layer containing an aromatic polycarbonate resin comprising a repeating unit represented by I). Embedded image Wherein Ar ¹ and Ar ² are the same or different aromatic divalent groups, R ¹ , R ² , R ³ and R ⁴ are the same or different substituted or unsubstituted alkyl groups, substituted or unsubstituted aromatic groups Represents a group. R ¹ and R ² , R ³ and R ⁴ , R ¹ and Ar ^1, or R ³ and Ar ² may form a ring together with a nitrogen atom.
Y ¹ and Y ² represent the same or different substituted or unsubstituted alkylene group, substituted or unsubstituted cycloalkylidene group, substituted or unsubstituted alkylene ether group, oxygen atom, sulfur atom, vinylene group, p ₁ and p ₂ is an integer of 1 or 2 each. Ar ³ and Ar ⁴ are the same or different, substituted or unsubstituted aromatic trivalent group, A is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylidene group, a substituted or unsubstituted alkylene Represents an ether group, an oxygen atom, a sulfur atom, and a vinylene group. n represents an integer of 5 to 5000. X represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylidene group, a substituted or unsubstituted alkylene ether group, or a group selected from the following general formula. —Ar ⁵ —Z—Ar ⁶ — (where Ar ⁵ and Ar ⁶ are the same or different, substituted or unsubstituted aromatic divalent groups, Z is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted Represents a substituted cycloalkylidene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.)] 2. The method according to claim 1, wherein at least one layer of the organic compound thin film of the light emitting layer comprises a layer containing an aromatic polycarbonate resin represented by the following general formula (I) and an electron transporting substance. 2. The organic thin film EL device according to 1. Embedded image [Wherein, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , A, R ¹ , R ² ,
R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ , n and X are the same as defined above, respectively. ] 3. The organic light-emitting device according to claim 1, wherein at least one layer of the organic compound thin film of the light-emitting layer comprises a layer containing an aromatic polycarbonate resin represented by the following general formula (I), an electron-transporting substance, and a light-emitting substance. The organic thin film EL device according to claim 1, wherein Embedded image [Wherein, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , A, R ¹ , R ² ,
R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ , n and X are the same as defined above, respectively. ] 4. An organic thin-film EL device comprising a light emitting layer composed of a plurality of organic compound thin films having at least one hole injection / transport layer between an anode and a cathode facing each other, wherein at least one of the hole injection / transport layers is provided. An organic thin film EL device, wherein one layer is a layer containing an aromatic polycarbonate resin represented by the following general formula (I). Embedded image [Wherein, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , A, R ¹ , R ² ,
R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ , n and X are the same as defined above, respectively. ] 5. An organic thin film EL having a light emitting layer composed of a plurality of organic compound thin films between an anode and a cathode facing each other.
In the device, the light emitting layer comprises a layer containing an aromatic polycarbonate resin represented by the following general formula (I), at least one hole injection transport layer and / or at least one layer.
An organic thin-film EL device comprising: an electron injection / transport layer; or at least one hole and an electron injection / transport layer. Embedded image [Wherein, Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , A, R ¹ , R ² ,
R ³ , R ⁴ , Y ¹ , Y ² , p ₁ , p ₂ , n and X are the same as defined above, respectively. ] 6. The aromatic polycarbonate resin comprises repeating units represented by the following general formulas (II) and (III), and the composition ratio of the repeating units is 0 <m / (m +
The organic thin film EL device according to claim 1, 2, 3, 4, or 5, wherein 1) is an aromatic polycarbonate resin satisfying ≦ 1. Embedded image Embedded image Wherein Ar ¹ and Ar ² are the same or different aromatic divalent groups, R ¹ , R ² , R ³ and R ⁴ are the same or different substituted or unsubstituted alkyl groups, substituted or unsubstituted aromatic groups Represents a group. R ¹ and R ² , R ³ and R ⁴ , R ¹ and Ar ^1, or R ³ and Ar ² may form a ring together with a nitrogen atom.
Y ¹ and Y ² represent the same or different substituted or unsubstituted alkylene group, substituted or unsubstituted cycloalkylidene group, substituted or unsubstituted alkylene ether group, oxygen atom, sulfur atom, vinylene group, p ₁ and p ₂ is an integer of 1 or 2 each. Ar ³ and Ar ⁴ are the same or different, substituted or unsubstituted aromatic trivalent group, A is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylidene group, a substituted or unsubstituted alkylene Represents an ether group, an oxygen atom, a sulfur atom, and a vinylene group. X represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylidene group, a substituted or unsubstituted alkylene ether group, or a group selected from the following general formula. —Ar ⁵ —Z—Ar ⁶ — (where Ar ⁵ and Ar ⁶ are the same or different, substituted or unsubstituted aromatic divalent groups, Z is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted Represents a substituted cycloalkylidene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.) M represents an integer of 5 to 5000, and l represents an integer of 0 to 5000. ]