JPH1121551A - Organic thin film el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an EL element having excellent durability by selecting an EL element wherein at least one layer of the organic thin compound layers of the luminescent layer is one containing an aromatic polycarbonate resin. SOLUTION: There is provided an organic thin film EL element wherein at least one layer of the organic compound thin layers of the luminescent layer is one containing an aromatic polycarbonate resin comprising repeating units represented by formula I and having a number-average molecular weight of 1,000-1,000,000 or one containing an aromatic polycarbonate resin, an electron transport substance such as anthraquinonedimethane and a fluorescent substance such as anthracene. In the formula, R1 and R2 are each H, an aromatic hydrocarbon or the like; Ar1 , Ar2 and Ar3 are each a divalent aromatic hydrocarbon or the like; m is an integer of 5-5,000; X is a divalent aliphatic, a divalent cycloaliphatic or a divalent group represented by formula II; R3 and R4 are each an alkyl, an aromatic hydrocarbon group or the like; l and m are each 0-40; Y is a single bond, a 1-12C alkylene, -O-, a divalent group represented by formula III or the like; R5 and R6 , are each an alkyl or an aromatic hydrocarbon group; a is 0-20; and b is an integer of 1-2,000.

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, R ₁ , R ₂ , Ar ₁ , Ar ₂ , Ar ₃ , 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 (2) and (3), and the composition ratio of the repeating unit is 0 <k / (k + j) ≦ 1 is an aromatic polycarbonate resin.

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Embedded image [Wherein R ₁ , R ₂ , Ar ₁ , Ar ₂ , Ar ₃ , k, j and X are the same as defined above, respectively. ]

According to the present invention, there is provided each of the organic thin film EL devices, wherein the aromatic polycarbonate resin is an aromatic polycarbonate resin comprising a repeating unit represented by the following general formula (4). Is done.

Embedded image [Wherein, R ₇ , n and X are the same as defined above, respectively. ]

Further, according to the present invention, the aromatic polycarbonate resin comprises a repeating unit represented by the following general formulas (5) and (3), and the composition ratio of the repeating unit is 0 <k / (k + j) ≦ 1 is an aromatic polycarbonate resin.

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Embedded image [Wherein, R ₇ , k, j 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 represented by the following general formula (I), the following general formula (2) or the following general formulas (2) and (3): (4) An organic thin film comprising a repeating unit represented by the following general formula (5) or the following general formulas (5) and (3), having a triarylamine structure, and having both hole transporting properties and fluorescent properties. In an EL device, it can be used as a charge transporting polymer material or a fluorescent material.

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Embedded image [In each of the above formulas, R ₁ , R ₂ , R ₇ , Ar ₁ , Ar ₂ , Ar ₃ ,
n, k, j and X are each 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 the same method as 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 (2) or (5) of the present invention is a third resin represented by the following general formula (6) or (7). Method of transesterifying diol compound having a primary amino group with bisaryl carbonate, phosgene method by solution or interfacial polymerization with phosgene, or chloroformate method using monochloroformate or bischloroformate derived from diol And so on. In this case, by using a diol represented by the following general formula (8) in combination, the repeating unit having a tertiary amino group represented by the general formula (2) and the diol represented by the general formula (3)
Or an aromatic polycarbonate resin comprising a repeating unit represented by the following formula: or a repeating unit having a tertiary amino group represented by the above formula (5) and a repeating unit represented by the above formula (3) An aromatic polycarbonate resin can be produced, whereby an aromatic polycarbonate resin having desired characteristics can be obtained. The ratio of the repeating unit having a tertiary amino group represented by the general formula (2) to the repeating unit represented by the general formula (3), and the tertiary group represented by the general formula (5) The ratio of the repeating unit having an amino group to the repeating unit represented by the general formula (3) can be selected from a wide range depending on desired characteristics. The aromatic polycarbonate resin comprising a repeating unit having a tertiary amino group represented by the general formula (1) or (4) is represented by the following general formula (6) or (7). It can be obtained by interfacial polymerization or solution polymerization of a diol compound having a tertiary amino group or the like and a bischloroformate derived from the general formula (8). Further, by polymerization of bischloroformate derived from a diol compound having a tertiary amino group or the like represented by the general formula (6) or (7) with a diol represented by the general formula (8) Is also obtained.

[0013]

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Embedded image HO—X—OH (8) [In each of formulas (6) to (8), R ₁ , R ₂ , R ₇ , Ar ₁ , Ar
₂ , Ar ₃ and X are each the same as defined above. ]

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. As described above, the present invention provides an aromatic polycarbonate resin comprising the repeating unit represented by the general formula (I), the general formula (2), or the general formula (2) and the general formula (3), particularly A light emitting layer comprising an organic thin film containing an aromatic polycarbonate resin comprising a repeating unit represented by the general formula (4), the general formula (5), or the general formula (5) and the general formula (3) The present invention relates to an organic thin-film EL device provided with:

The aromatic polycarbonate resin used in the present invention may be a homopolymer comprising a repeating unit represented by the general formula (2) or (5), or a homopolymer represented by the general formula (1) or (4). And a random or block copolymer having a repeating unit represented by formulas (2) and (3) or a repeating unit represented by formulas (5) and (3) as a structural unit. Any of polymers may be used. The molecular weight of the aromatic polycarbonate resin of the present invention is 1 in terms of polystyrene-equivalent number average molecular weight.
000 to 1,000,000, preferably 2000 to 500
000.

In the general formulas, Ar ₁ , Ar ₂ and Ar _{3 each} represent an aromatic hydrocarbon or a heterocyclic divalent group, and specific examples thereof include phenyl, naphthyl,
Biphenylyl group, terphenylyl group, pyrenyl group, fluorenyl group, 9,9-dimethyl-2-fluorenyl group and the like, and thienyl group, benzothienyl group as a heterocyclic group,
Examples thereof include a divalent group such as a furyl group, a benzofuranyl group, a carbazolyl group, and a diphenylthioether group and a diphenylthioether group in which two aryl groups are bonded by oxygen and sulfur. These aromatic hydrocarbons or heterocyclic groups may have an alkyl group, an alkoxy group and a halogen atom described later as substituents.

The substituents R ₁ and R ₂ in each formula represent a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon or a heterocyclic group. Specific examples thereof include the following. Phenyl group, naphthyl group, biphenylyl group, terphenylyl group, pyrenyl group, fluorenyl group, 9,9-dimethyl-2-fluorenyl group, etc. as an aromatic hydrocarbon; and thienyl group, benzothienyl group, furyl group as a heterocyclic group Benzofuranyl group, carbazolyl group and the like. When R ₁ and R ₂ form a ring, 9
-Fluorenylidene, 5H-dibenzo [a, d] cycloheptenylidene and the like. A diphenylthioether group or diphenylthioether group in which these aryl groups are bonded by oxygen or sulfur may have a substituent described later.

The substituent R ₇ in each formula is a hydrogen atom,
It represents a halogen atom, an alkoxy group, an aryloxy group, an acyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, wherein the alkyl group is described later, and the aryl group is R ₁ , R 2 ₂ can be exemplified. Further, these may have a lower alkyl group, a lower alkoxy group and a halogen atom described later as substituents.

Specific examples of the substituents of Ar ₁ , Ar ₂ and Ar ₃ , the substituents of the aromatic hydrocarbons of R ₁ and R ₂ , the substituents of the heterocyclic group, and the substituents of R ₇ are shown below. . (1) Halogen atom, cyano group, nitro group. (2) alkyl group; preferably C ₁ -C _12, especially C ₁
To C ₈ , more preferably a C _{1 to} 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 to} C ₄ alkoxy group,
It may contain a phenyl group or a phenyl group substituted with a halogen atom, a C ₁ -C ₄ alkyl group or a C ₁ -C ₄ alkoxy group. Specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a 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 and the like. (3) alkoxy group (-OR ₈ ); R ₈ represents an alkyl group defined in (2). Specifically, methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy, n-butoxy, s-butoxy, i-butoxy, 2-hydroxyethoxy, 2-cyano Examples include an ethoxy group, a benzyloxy group, a 4-methylbenzyloxy group, and a trifluoromethoxy group.

(4) Aryloxy group: Examples of the aryl group include a phenyl group and a naphthyl group. This is C ₁
It may contain a C ₄ to C ₄ alkoxy group, a C _{1 to} C ₄ alkyl group or a halogen atom as a substituent. Specifically, a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methylphenoxy group, a 4-methoxyphenoxy group, a 4-chlorophenoxy group, a 6-methyl-2
-Naphthyloxy group and the like. (5) a substituted mercapto group or an arylmercapto group;
Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group. (6) alkyl-substituted amino group; the alkyl group represents the alkyl group defined in (2). Specific examples include a dimethylamino group, a diethylamino group, an N-methyl-N-propylamino group, an N, N-dibenzylamino group, and the like. (7) acyl group; specific examples include an acetyl group, a propionyl group, a butyryl group, a malonyl group, and a benzoyl group.

Next, specific examples of the diol represented by the general formula (8) 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 represented by the general formula (6) or (7) and, if necessary, A diol compound having a tertiary amino group represented by the general formula (6) or (7) is obtained by transesterification with a diol represented by the formula (8) or a phosgene method; It can be produced by a method of reacting bischloroformate derived from a diol represented by the general formula (8) in the presence of a solvent and a deoxidizing agent.

Hereinafter, the production 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.

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 above-mentioned 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 may 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 way 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 of the present invention, a metal, alloy, metal oxide or the like having a work function of 4 eV, preferably greater 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 smaller 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-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 encapsulating silicon oil or the like. It is.

When the organic thin film EL device of the present invention thus obtained is used, a positive electrode is connected to the anode and a negative electrode is connected to the cathode, and a voltage is applied, 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.

[0041]

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 A diol compound having a tertiary amino group has the following structure

Embedded image Dissolve 7.59 parts of 4- [bis (3-hydroxyphenyl) amino] stilbene represented by the following formula in 80 parts of dehydrated tetrahydrofuran (THF), and add 6.07 parts of triethylamine while stirring under a stream of nitrogen gas. After the bischloroformate of diethylene glycol 4.85
A solution prepared by dissolving the above solution in 16 parts of THF was added dropwise over about 1 hour while cooling to 20 ° C. in a water bath. Then, the reaction was further stirred for 1 hour at room temperature, and 4% by weight of phenol THF was added.
The reaction was terminated by adding 4.24 parts of the solution. Thereafter, the precipitated salt was removed by filtration, and the obtained reaction solution was dropped into 2500 parts of methanol to obtain a polycarbonate resin. This material was filtered and dried, taken out, and again with THF180.
The reprecipitation operation of dissolving in 2 parts of methanol and dropping into 2200 parts of methanol was repeated twice to obtain a polycarbonate resin (No. 1) having the following structure.

Embedded image When the molecular weight of the aromatic polycarbonate resin was measured by gel permeation chromatography,
The molecular weight in terms of polystyrene was as follows. Number average molecular weight 17000 Weight average molecular weight 64300 In addition, the glass transition boat of the resin was measured for
It was 97 degreeC as measured by C). Further, according to the infrared absorption spectrum (film) of the resin, 1760
An absorption based on C = 0 stretching vibration of carbonate was observed at cm ^-1 . The results of elemental analysis were as follows. (C ₃₂ H ₂₇ NO ₇ ) n C% H% N% Found 71.44 5.14 2.52 Calculated 71.50 5.06 2.61

Production Examples 2 and 3 Similarly, aromatic polycarbonate resins (Nos. 2 and 3) shown in Table 1 were obtained.

[Table 1]

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 the aromatic polycarbonate resin of No. 1 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 sufficient drying, the substrate was set inside the vapor deposition apparatus, and a 200 nm MgAg alloy layer was formed at a degree of vacuum of 10 ⁻⁴ Pa through a mask 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 an anode, and M
When gAg 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 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 was used. Using the EL element manufactured in this manner, 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. 3 was used. Using the EL element manufactured in this manner, 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 7 An organic thin film EL device was manufactured in the same manner as in Example 4. However, compound N is used as a polycarbonate resin component.
o. 2 was used. 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. Also,
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. 3 was used. 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. Also,
This organic layer did not undergo any alteration such as crystallization.

Example 9 An ITO substrate etched into a 2 mm stripe was washed with boiling alcohol, and the surface was 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. 1
The organic light-emitting layer having a thickness of 90 nm was formed by a spin coating method using the aromatic polycarbonate resin solution of (1). After performing sufficient drying, set the substrate inside the evaporation device,
200 nm Mg through a mask at a degree of vacuum of 10 ^-4 Pa
An Ag 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 an anode, and MgAg was used.
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 10 In the same manner as in Example 9, a copper phthalocyanine layer and a compound No. 1 were formed on an ITO substrate. 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 2mm x 2mm
Met. Using the EL device thus manufactured, I
When TO 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 11 A copper phthalocyanine layer was formed on an ITO substrate in the same manner as in Example 9. On top of this, the compound No. used in Example 3 was used.
Using a mixed solution of the aromatic polycarbonate resin, PBD and perylene derivative (B), an organic light-emitting layer was formed by a spin coating method. Further, the oxadiazole compound 3 of the compound (D) represented by the following structural formula was obtained by a vacuum evaporation method.
An electron injection / transport layer of 0 nm was produced. Further, a 200 nm MgAg alloy layer is formed through a mask, and the organic thin film E is formed.
An L element was produced. The size of the light emitting surface was 2 mm × 2 mm. Using the EL element manufactured in this way, IT
When O 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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[0055]

According to the organic thin film EL device of the present invention, the organic compound thin film constituting the light emitting layer has the triarylamine structure of the above-mentioned general formula (I) or (2).
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. Further, in the organic thin film EL device of the present invention, the aromatic polycarbonate resin is preferably represented by the general formula (4), the general formula (5), or the general formula (5) and the general formula (3). A device using an aromatic polycarbonate resin composed of the repeating unit represented is an organic thin film EL device having more excellent performance.

Claims (8)

[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, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heterocyclic group, which may be the same or different, and May be formed. Ar ₁ , Ar ₂ , and Ar ₃ represent a substituted or unsubstituted aromatic hydrocarbon divalent group or a substituted or unsubstituted heterocyclic group divalent group, and may be the same or different. n represents an integer of 5 to 5000.
X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula: In the formula, R ₃ and R ₄ each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom l, m: each independently represent an integer of 0 to 4 Y: a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Where Z represents a divalent group of an aliphatic hydrocarbon) or a divalent group represented by the following general formula: (Wherein, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.) Represents｝. ] 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, R ₁ , R ₂ , Ar ₁ , Ar ₂ , Ar ₃ , 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, R ₁ , R ₂ , Ar ₁ , Ar ₂ , Ar ₃ , 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, R ₁ , R ₂ , Ar ₁ , Ar ₂ , Ar ₃ , 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, R ₁ , R ₂ , Ar ₁ , Ar ₂ , Ar ₃ , n and X are the same as defined above, respectively. ] 6. The aromatic polycarbonate resin comprises repeating units represented by the following general formulas (2) and (3), and the composition ratio of the repeating units is 0 <k / (k + j).
The organic thin film E according to claim 1, 2, 3, 4, or 5, which is an aromatic polycarbonate resin satisfying ≦ 1.
L element. Embedded image Embedded image [Wherein, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heterocyclic group, which may be the same or different, and May be formed. Ar ₁ , Ar ₂ , and Ar ₃ represent a substituted or unsubstituted aromatic hydrocarbon divalent group or a substituted or unsubstituted heterocyclic group divalent group, and may be the same or different. X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula: In the formula, R ₃ and R ₄ each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom l, m: each independently represent an integer of 0 to 4 Y: a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Where Z represents a divalent group of an aliphatic hydrocarbon) or a divalent group represented by the following general formula: (Wherein, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.) Represents｝. k is an integer of 5-5000, j is 0
Represents an integer of 5000. ] 7. The organic compound according to claim 1, wherein the aromatic polycarbonate resin is an aromatic polycarbonate resin comprising a repeating unit represented by the following general formula (4). Thin film EL element. Embedded image [In the formula, R ₇ represents a hydrogen atom, a halogen atom, an alkoxy group, an aryloxy group, an acyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. n represents an integer of 5 to 5000. X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula: In the formula, R ₃ and R ₄ each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom l, m: each independently represent an integer of 0 to 4 Y: a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Where Z represents a divalent group of an aliphatic hydrocarbon) or a divalent group represented by the following general formula: (Wherein, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.) Represents｝. ] 8. The aromatic polycarbonate resin comprises repeating units represented by the following general formulas (5) and (3), and the composition ratio of the repeating units is 0 <k / (k + j).
6. The organic thin-film EL device according to 1, 2, 3, 4 or 5, wherein the organic thin-film EL device is an aromatic polycarbonate resin satisfying ≦ 1. Embedded image Embedded image [In the formula, R ₇ represents a hydrogen atom, a halogen atom, an alkoxy group, an aryl group, an acyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula: {Wherein, R ₃ and R ₄ each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom l, m: an integer of 0 to 4 Y: a single bond A linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Where Z represents a divalent group of an aliphatic hydrocarbon) or a divalent group represented by the following general formula: (Wherein, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.) Represents｝. k is an integer of 5-5000, j is 0
Represents an integer of 5000. ]