JP2003221484A - Light emitting polymer composition, organic electroluminescent element and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a light emitting polymer composition capable of forming an organic electroluminescent element (an EL element) which has high luminous efficiency and excellent durability and of forming a functional layer of an organic material with a wet method, and to provide an organic EL element and a method of manufacturing the same. <P>SOLUTION: The light emitting polymer composition is composed of a polymer component impregnated with a phosphorescent substance and the polymer component is composed of a hole-transporting component made from 50-99 mol% of a hole- transporting monomer and an electron-transporting component made from 50-1 mol% of an electron-transporting monomer. The polymer component either is a copolymer composed of 50-99 mol% of a structure unit stemming from a hole-transporting monomer and 50-1 mol% of a structure unit stemming from an electron-transporting monomer or is composed of a polymer derived from a hole-transporting monomer and a polymer derived from an electron-transporting monomer (wherein, the ratio of the two polymers is 50:50-99:1 in terms of a monomeric molar ratio). An organic EL element and a method of manufacture using the light emitting polymer composition are also provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a luminescent polymer composition which can be suitably used as an organic electroluminescent material, an organic electroluminescent element and a method for producing the same.

[0002]

2. Description of the Related Art Organic electroluminescent devices are
Being thin, capable of being driven by a DC voltage, having a wide viewing angle and high visibility because it is a self-luminous element, and having excellent characteristics such as fast response speed Therefore, it is expected as a next-generation display element, and its research is actively conducted. Conventionally,
The organic electroluminescent element has a single layer structure in which a light emitting layer made of an organic material is formed between an anode and a cathode, a structure having a hole transport layer between the anode and the light emitting layer, and a cathode. Multilayered structures such as those having an electron transport layer between the light emitting layer and the like are known, and these organic electroluminescent elements each have an electron injected from a cathode and a hole injected from an anode. However, the light is emitted by recombination in the light emitting layer.

In such an organic electroluminescence device, as a method for forming a functional organic material layer such as a light emitting layer and a hole transport layer, a dry method in which an organic material is formed by vacuum vapor deposition and an organic material is dissolved A wet method is known in which the solution is formed by coating and drying. Among these, the dry method has a complicated process, and it is difficult to cope with mass production, and there is a limit in forming a layer having a large area. On the other hand, in the wet method, the process is relatively simple, mass production is possible, and a functional organic material layer having a large area can be easily formed. Therefore, it is advantageous as compared with the dry method.

On the other hand, the functional organic material layer constituting the organic electroluminescence device is required to have high durability and high luminous efficiency, and conventionally, it is required that various functional materials are used. The following is known, and recently, a functional organic material layer containing a phosphorescent organic iridium compound or an organic osmium compound as a light emitting molecule has been proposed (see, for example, Patent Document 1). The functional organic material layer is made of only an organic iridium compound or an organic osmium compound, or these compounds, 4,4′-N,
N'-dicarbazole biphenyl and 4,4'-bis [N
And a hole-transporting material such as-(1-naphthyl) -N-phenyl-amino) biphenyl. However, since this functional organic material layer is formed by a dry method, it is difficult to cope with mass production and to form a large-area functional organic material layer.

In addition, MRS 2000 Fall Me
eting (November 27 − December 1, 2000 Bost
on, Massachusetts, USA), a luminescent material composed of an iridium compound, polyvinylcarbazole, and oxadiazole has been proposed. However, this luminescent material has a high luminous efficiency, but has a problem of poor durability.

[0006]

[Patent Document 1] International Publication No. 00/70655 pamphlet

[0007]

The present invention has been made based on the above circumstances, and its purpose is to:
To provide a light-emitting polymer composition which has a high luminous efficiency and can obtain an organic electroluminescence device having excellent durability and which can easily form a functional organic material layer by a wet method. is there. Another object of the present invention is to provide an organic electroluminescent device having high luminous efficiency and excellent durability, and a method for manufacturing the same.

[0008]

The luminescent polymer composition of the present invention comprises a phosphorescent agent in the polymer component,
The polymer component is a hole transporting component formed of 50 to 99 mol% of the hole transporting monomer, and 50 to 1 mol%.
And an electron transporting component formed from the electron transporting monomer.

In this luminescent polymer composition, the polymer component is a structural unit 50 derived from a hole transporting monomer.
It is possible to use a copolymer composed of ˜99 mol% and 50 to 1 mol% of a structural unit derived from an electron transporting monomer. Alternatively, in the above luminescent polymer composition, the polymer component is composed of a hole transporting polymer obtained by polymerizing a hole transporting monomer and an electron transporting polymer obtained by polymerizing an electron transporting monomer, The ratio of the hole transporting polymer and the electron transporting polymer can be 50:50 to 99: 1 in terms of a molar ratio converted into a monomer.

Further, it is preferable that the hole transporting monomer is a tertiary aromatic amine derivative and the electron transporting monomer is an oxadiazole derivative. Further, the phosphorescent agent is preferably a complex compound of a metal selected from iridium, platinum and osmium.

In particular, the phosphorescent agent is preferably an iridium complex compound represented by the following general formula (1).

[0012]

[Chemical 3]

[In the formula, R ¹ and R ² each represent a substituent consisting of a fluorine atom, an alkyl group or an aryl group, and may be the same as or different from each other. m is an integer of 0-4 and n is an integer of 0-4. It is preferable that the content of the impurity compound represented by the following general formula (X) in the phosphorescent agent is 1000 ppm or less.

[0014]

[Chemical 4]

[In the formula, R ¹ and R ² each represent a substituent consisting of a fluorine atom, an alkyl group or an aryl group, and may be the same or different from each other. m is an integer of 0-4 and n is an integer of 0-4. ]

The organic electroluminescent device of the present invention comprises a hole transporting component formed of 50 to 99 mol% of a hole transporting monomer and an electron transporting component formed of 50 to 1 mol% of an electron transporting monomer. A functional organic material layer having a function as a light emitting layer or a hole transporting layer, which is formed from a light emitting polymer composition containing a phosphorescent agent in a polymer component containing a functional component. It is characterized by The method for producing an organic electroluminescence device of the present invention is directed to a hole-transporting component formed of 50 to 99 mol% of a hole-transporting monomer and an electron-transporting component formed of 50 to 1 mol% of an electron-transporting monomer. A solution of a luminescent polymer composition containing a phosphorescent agent in a polymer component composed of an organic solvent and an organic solvent is applied to the surface of a substrate, and the organic solvent is removed from the resulting coating film. The method is characterized by having a step of forming a functional organic material layer by performing treatment.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The luminescent polymer composition of the present invention contains the component (B) composed of a phosphorescent agent in the component (A) composed of a polymer. A hole transporting component formed of 99 mol% of the hole transporting monomer and an electron transporting component formed of 50 to 1 mol% of the electron transporting monomer are used.

Specifically, the polymer of the component (A) in the present invention is a copolymer (A-1) comprising a structural unit derived from a hole transporting monomer and a structural unit derived from an electron transporting monomer. Or a mixed polymer (A-2) containing a hole-transporting polymer obtained by polymerizing a hole-transporting monomer and an electron-transporting polymer obtained by polymerizing an electron-transporting monomer.

In the present invention, "hole transporting polymer"
The term "polymer" has a function of injecting holes from the anode and transporting the holes when an electric field is applied, or a function of blocking electrons injected from the cathode. A monomer that gives a hydrophilic polymer is referred to as a "hole transporting monomer". Examples of such a hole transporting monomer include a polymerizable compound having a structure in which an electron-donating group such as an amino group is bonded to a large conjugated skeleton such as benzene, naphthalene, and biphenyl. Aromatic tertiary amine compounds having a triphenylamine skeleton structure or a carbazole skeleton structure are hole transporting monomers that give a hole transporting polymer having excellent properties.

The term "electron-transporting polymer" means a polymer having a function of injecting electrons from the cathode and transporting the electrons when an electric field is applied, or a function of blocking holes injected from the anode. A monomer that gives an electron-transporting polymer as described above is referred to as an “electron-transporting monomer”. As such an electron transporting monomer,
Oxadiazole derivatives, pasophenanthroline derivatives, triazole derivatives and the like can be mentioned.

[Copolymer (A-1)] Copolymer (A-
1) is a copolymer of a hole transporting monomer and an electron transporting monomer, and this copolymer is a random copolymer or a block copolymer obtained from the hole transporting monomer and the electron transporting monomer. It may be either a polymer or an alternating copolymer.

As the hole transporting monomer for obtaining the copolymer (A-1), it is preferable to use a tertiary aromatic amine derivative, especially a carbazole derivative, and specific examples thereof include N-vinylcarbazole. , 3,6-dimethyl-9-vinylcarbazole, 3,6-diethyl-9-
Examples thereof include vinylcarbazole, 3-methyl-9-vinylcarbazole, 3-ethyl-9-vinylcarbazole and the like. Among these, N-vinylcarbazole,
3,6-Dimethyl-9-vinylcarbazole is preferred.

An oxadiazole derivative is preferably used as the electron transporting monomer for obtaining the copolymer (A-1), and specific examples thereof include 2-β-naphthyl-5- (4-vinyl. Phenyl) -1,3,4-oxadiazole, 2-α-naphthyl-5- (4-vinylphenyl) -1,3,4-oxadiazole, 2-phenyl-5- (4-vinylphenyl) -Oxadiazole, 2
-Phenyl-5- (4-vinyl-p-biphenyl)-
1,3,4-oxadiazole, 2- (p-biphenyl) -5- (4-vinylphenyl) -oxadiazole, 2- (p-biphenyl) -5- (4-propenylphenyl) -1, 3,4-oxadiazole, 2-t-butoxyphenyl-5- (4- (4-vinylphenyl)-
Examples thereof include p-biphenyl) -1,3,4-oxadiazole or these oxadiazole derivatives substituted with an acryloyl group or a methacryloyl group. Among these, 2-β-naphthyl-5- (4-vinylphenyl) -1,3,4-oxadiazole, 2-
(P-biphenyl) -5- (4-vinylphenyl)-
1,3,4-oxadiazole, 2- (p-biphenyl) -5- (4-propenylphenyl) -1,3,4-
Oxadiazole is preferred.

In the copolymer (A-1), the molar ratio of the structural unit derived from the hole transporting monomer to the structural unit derived from the electron transporting monomer is 50:50 to 99: 1. The ratio is preferably 65:35 to 95: 5. When the proportion of the structural unit derived from the hole transporting monomer is too small, the hole injection amount is reduced, which is not preferable. On the other hand, if the proportion of structural units derived from the hole transporting monomer is too large, the amount of hole injection increases and the balance in recombination with electrons is lost, which is not preferable.

The copolymer (A-1) has a polystyrene-reduced weight average molecular weight of 2,000 to 1,500,000, especially 5,0 by gel permeation chromatography.
It is preferably from 00 to 500,000. When the weight average molecular weight is less than 2,000, the resulting luminescent polymer composition tends to have insufficient heat resistance, stability in a thin film state and mechanical strength. On the other hand, when the weight average molecular weight exceeds 1,500,000, the resulting luminescent polymer composition tends to have a remarkably high solution viscosity, resulting in poor handleability in the production of an organic electroluminescence device. However, it is not preferable because the stringiness of the solution occurs. The total proportion of the unreacted hole transporting monomer and electron transporting monomer contained in the copolymer (A-1) is preferably 5% by mass or less.

The copolymer (A-1) is obtained by copolymerizing a hole transporting monomer and an electron transporting monomer in the presence of a cationic polymerization catalyst, a radical polymerization catalyst or an anionic polymerization catalyst in an appropriate polymerization solvent. It is obtained by doing.

Here, as the polymerization solvent, halogenated hydrocarbons such as methylene chloride and chlorobenzene,
Aromatic hydrocarbons such as toluene and benzene, ether solvents such as dibutyl ether, diphenyl ether, dioxane and tetrahydrofuran, and highly polar solvents such as acetonitrile, nitrobenzene, N-methylpyrrolidone and dimethylacetamide can be used. As the cationic polymerization _{catalyst, HI-ZnI 2, I 2} , I 2 -HI
Etc. can be used.

As the radical polymerization catalyst, azobisisobutyronitrile, azobis-1-acetoxy-1-phenylethane or the like can be used. As the anionic polymerization catalyst, alkyllithium or the like can be used. The proportion of the polymerization catalyst used is 0.0001 per 1 mol of the total of the hole transporting monomer and the electron transporting monomer.
~ 0.5 mol. The reaction temperature is, for example, −150 to 50 ° C. when a cationic polymerization catalyst is used,
When using a radical polymerization catalyst, for example, 60 to 200
℃, when using an anionic polymerization catalyst, for example 0
~ 100 ° C.

[Mixed Polymer (A-2)] Mixed Polymer (A
-2) is a mixture of a hole transporting polymer obtained by polymerizing a hole transporting monomer and an electron transporting polymer obtained by polymerizing an electron transporting monomer. Here, specific examples of the hole-transporting monomer for obtaining the hole-transporting polymer and the electron-transporting monomer for obtaining the electron-transporting polymer include positive for obtaining the above-mentioned copolymer (A-1). Specific examples of the hole transporting monomer and the electron transporting monomer can be mentioned.

The hole-transporting polymer which constitutes the mixed polymer (A-2) has a polystyrene-reduced weight average molecular weight of 5,000-by gel permeation chromatography.
1,000,000, especially 10,000-1, 00
It is preferably 10,000. When the weight average molecular weight is less than 5,000, the resulting luminescent polymer composition tends to have insufficient heat resistance, stability in a thin film state, and mechanical strength. On the other hand, when the weight average molecular weight exceeds 1,000,000, the resulting luminescent polymer composition tends to have a remarkably high solution viscosity, resulting in poor handleability in the production of an organic electroluminescence device. However, it is not preferable because the stringiness of the solution occurs.

The electron transporting polymer preferably has a polystyrene reduced weight average molecular weight of 1,000 to 1,000,000 as determined by gel permeation chromatography. When the weight average molecular weight is less than 1,000, the resulting polymer tends to have insufficient heat resistance, stability and mechanical strength, while the weight average molecular weight is less than 1,000,000. When it exceeds, the resulting luminescent polymer composition tends to have a remarkably high solution viscosity, and in the production of the organic electroluminescence device, the handling property is lowered, and the stringing property of the solution occurs, Not preferable.

The ratio of the hole transporting polymer to the electron transporting polymer in the mixed polymer (A-2) is 50:50 to 99: 1 in terms of monomer, preferably 70:30 to 99. : 1 If the proportion of the hole-transporting polymer is too small, the amount of hole injection is reduced, which is not preferable. On the other hand, if the proportion of the hole-transporting polymer is too large, the amount of hole injection increases and the balance in recombination with electrons is lost, which is not preferable.

The hole-transporting polymer and the electron-transporting polymer can be produced by a cationic polymerization method, a radical polymerization method or an anionic polymerization method in an appropriate solvent for polymerization.

When the polymer is produced by the cationic polymerization method, the polymerization solvent is a halogenated hydrocarbon represented by methylene chloride, chlorobenzene or the like, an ether solvent such as dibutyl ether, diphenyl ether, dioxane or tetrahydrofuran, and acetonitrile. A highly polar solvent such as nitrobenzene can be used. As a cationic polymerization catalyst, HI-Zn
A catalyst such as I ₂ , I ₂ , and I ₂ -HI can be used, and in addition, a catalyst formed by combining a Lewis acid and a base such as a metal halide / ether complex can also be used. The ratio of such a cationic polymerization catalyst used is 0.01 to 0.00001 mol with respect to 1 mol of N-vinylcarbazole initially polymerized. The reaction temperature is, for example, −150 to 50 ° C.

When the polymer is produced by the radical polymerization method, the polymerization solvent is an amide solvent such as dimethylformamide, dimethylacetamide or N-methylpyrrolidone, benzene, toluene, xylene,
Hydrocarbon-based solvents such as hexane and cyclohexane, esters such as γ-butyrolactone and ethyl lactate, and ketone-based solvents such as cyclohexylbenzophenone and cyclohexanone can be used.

As the radical polymerization catalyst, peroxide and
4-methylsulfonyloxy-2,2 ', 6,6'-tetramethyl-1-piperidine-N-oxide, 2,
2 ', 5,5'-tetramethylpyrrolidine oxide,
4-oxo-2,2 ', 6,6'-tetramethyl-1-
It is possible to use a sulfide-based catalyst that is a combination of N-oxy radicals such as piperidine-N-oxide. The proportion of such radical polymerization catalyst used is
The amount is 0.0001 to 0.5 mol with respect to 1 mol of the monomer. The reaction temperature is, for example, 60 to 200 ° C.

In the case of producing a polymer by an anionic polymerization method, as a polymerization solvent, an aromatic hydrocarbon such as toluene and benzene, an aliphatic hydrocarbon such as hexane and heptane, an ether compound such as tetrahydrofuran and the like are used. it can. As an anionic polymerization catalyst,
Alkali metal compounds such as naphthalene potassium and butyl lithium, and alkaline earth metal compounds such as an art type complex of barium and aluminum can be used. Of these, butyllithium and naphthalenelithium are preferable. The proportion of such anionic polymerization catalyst used is 0.0001 to 0.1 mol per mol of the monomer. The reaction temperature is, for example, 0 to 100 ° C.

[Component (B)] The component (B) contained in the component (A) made of the above-mentioned polymer is a component made of a phosphorescent agent. As the phosphorescent agent, it is preferable to use a complex compound of a metal selected from iridium, platinum and osmium, and particularly preferable is a complex compound of an iridium metal.

In the present invention, as the iridium complex compound, iridium and phenylpyridine, phenylpyrimidine, bipyridyl, 1-phenylpyrazole, 2-
Phenylquinoline, 2-phenylbenzothiazole, 2
-Phenyl-2-oxazoline, 2,4-diphenyl-
1,3,4-oxadiazole, 5-phenyl-2-
(4-pyridyl) -1,3-oxadiazole, 2-
(2-Pyridyl-thiophene) -2-phenyl-4H-
A complex compound with a nitrogen atom-containing aromatic compound such as 3,1-benzoxazine-4 or a derivative thereof can be used. Specific examples of such iridium complex compounds include compounds represented by the following general formulas (1) to (3) and compounds represented by the following formulas (a) to (j). it can.

[0040]

[Chemical 5]

[0041]

[Chemical 6]

[0042]

[Chemical 7]

[In the above general formulas (1) to (3), R ¹ and R ² each represent a substituent consisting of a fluorine atom, an alkyl group or an aryl group, and may be the same or different. It may be one. m is 0
4 is an integer, and n is an integer of 0-4. In the above, specific examples of the alkyl group related to the substituent R ¹ or R ² include a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an n-butyl group, an isobutyl group, a hexyl group and an octyl group. Can be mentioned. Specific examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a biphenyl group and a naphthyl group.

[0044]

[Chemical 8]

[0045]

[Chemical 9]

Among the above, it is particularly preferable to use the iridium complex compound represented by the general formula (1) (hereinafter referred to as "specific iridium complex compound"). In addition, specific preferable examples of the specific iridium complex represented by the general formula (1) include a compound represented by the following formula (k) [tris (2-2-phenylpyridyl) iridium],
Examples thereof include a compound represented by the following formula (1) and a compound represented by the following formula (m).

[0047]

[Chemical 10]

[0048]

[Chemical 11]

This specific iridium complex compound is usually synthesized by reacting a compound represented by the following general formula (A) with a compound represented by the following general formula (B) in the presence of a polar solvent. However, the content of the specific impurity compound represented by the following general formula (X), which occurs in that case, is 1
It is important that it is 000 ppm or less.

[0050]

[Chemical 12]

[0051]

[Chemical 13]

[In the general formula (A), the general formula (B) and the general formula (X), R ¹ and R ² are the same as in the general formula (1). The specific iridium complex compound in which the content of the specific impurity compound is 1000 ppm can be obtained by purifying the reaction product of the above synthetic reaction.

In the specific iridium complex compound, when the content of the specific impurity compound exceeds 1000 ppm, the light emission performance of the specific iridium complex compound is hindered, so that both the emission brightness and the emission efficiency are increased. It becomes difficult to obtain a high organic electroluminescence element.

The reaction of the compound represented by the general formula (A) with the compound represented by the general formula (B) for synthesizing a specific iridium complex compound is carried out in the presence of a polar solvent. Be seen. Here, as the polar solvent, those having an appropriate boiling point can be selected from glycerin, ethylene glycol derivatives and propylene glycol derivatives, and specific examples of the ethylene glycol derivative include ethylene glycol monomethoxy ether. , Ethylene glycol monoethoxy ether, ethylene glycol monobutoxy ether and the like. In this reaction, the reaction temperature is usually 1
The reaction time is usually 50 to 300 ° C. and the reaction time is usually 1 to 24 hours.

The product of the above reaction is usually a dimer of the compound represented by the general formula (1), that is, a specific impurity compound represented by the general formula (X), for example, 10
Since it is contained in a proportion of about 00 to 100,000 ppm, the content of the specific impurity compound can be reduced to 1000 ppm or less by purifying this reaction product. Here, the purification method is not particularly limited, but, for example, a solvent extraction method, a column chromatography method, a recrystallization method, or a method combining these methods can be used.

According to the phosphorescent agent composed of the specific iridium complex compound thus obtained, since the content of the specific impurity compound is extremely small, the luminescent performance of the specific iridium complex compound is sufficiently exhibited, Therefore, it is possible to obtain an organic electroluminescence device having high emission brightness and high emission efficiency.

Preferred specific examples of the specific iridium complex represented by the general formula (2) include compounds represented by the following formula (n).

[0058]

[Chemical 14]

The platinum complex compound used as the phosphorescent agent is a porphyrin platinum complex, a phthalocyanine platinum complex or the like, specifically, octaethylporphyrin platinum complex, 2,3,7,8,12,13,17, 18-
Octaethyl-21H, 23H-platinum complex etc. can be mentioned. Further, as the osmium complex compound,
Various phosphorescent agents generally used can be used.

The proportion of the phosphorescent agent used is such that the polymer component 10
The amount is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 0 parts by mass. If this ratio is less than 0.1 parts by mass, it may be difficult to obtain sufficient light emission. On the other hand, this ratio is 3
If the amount exceeds 0 parts by mass, the proportion of the phosphorescent agent is excessive, which may cause a phenomenon of concentration quenching in which the brightness of the emission rather decreases, which is not preferable.

In the luminescent polymer composition of the present invention,
Usually, it is prepared as a composition solution by dissolving the above-mentioned polymer component and phosphorescent agent in an appropriate organic solvent, and this composition solution is applied to the surface of the substrate on which the functional organic material layer is to be formed. And forming a functional organic material layer in an organic electroluminescence device, which comprises a phosphorescent agent contained in a medium composed of a polymer component, by performing an organic solvent removal treatment on the obtained coating film. You can The functional organic material layer thus obtained may be applied as a light emitting layer or a hole transporting layer.

In the above, the organic solvent for preparing the composition solution is not particularly limited as long as it can dissolve the polymer component and the phosphorescent agent used, and specific examples thereof include chloroform and chlorobenzene. , Halogenated hydrocarbons such as tetrachloroethane, amide type solvents such as dimethylformamide and N-methylpyrrolidone, ethyl lactate, propylene glycol methyl ether acetate, ethyl ethoxy propionate, methyl amyl ketone, and the like. These organic solvents can be used alone or in combination of two or more. Among these, in that a thin film having a uniform thickness can be obtained,
Those having an appropriate evaporation rate, specifically a boiling point of 70 to
It is preferable to use an organic solvent at about 200 ° C.

The ratio of the organic solvent used varies depending on the kinds of the polymer component and the phosphorescent agent, but usually the total concentration of the polymer component and the phosphorescent agent in the composition solution is 0.1.
It is a ratio of 10% by mass. Further, as a means for applying the composition solution, for example, a spin coating method, a dipping method, a roll coating method, an ink jet method, a printing method or the like can be used. The thickness of the functional organic material layer formed is not particularly limited, but is usually 1
It is selected in the range of 0 to 1000 nm, preferably 30 to 200 nm.

According to such a luminescent polymer composition,
It is possible to obtain an organic electroluminescence device having high luminous efficiency and excellent durability, and moreover, a functional organic material layer can be easily formed by a wet method.

[0065]

EXAMPLES Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

(1) Synthesis of Polymer: <Synthesis Example 1 (Copolymer)> In a 1000 mL two-neck round bottom flask, under nitrogen gas atmosphere, 0.95 mol of N-vinylcarbazole and 2-biphenyl- 5 (p-vinylphenyl) -1,3,4-oxadiazole (hereinafter referred to as "V-
It is abbreviated as "PBD". ) 0.05 mol and 0.02 mol of azobisisobutyronitrile are added, and dimethylformamide in an amount which is 3 times the mass of the monomer is added,
Then, radical polymerization of the monomer was performed under the conditions of 70 ° C. and 12 hours. Then, the obtained reaction solution was poured into a large amount of methanol to solidify the reaction product. Further, by repeating the reprecipitation purification, the proportion of unreacted monomer contained in the reaction product was adjusted to 1% by mass or less. When the obtained copolymer was analyzed, it was found to be a copolymer composed of 94.8 mol% of structural units derived from N-vinylcarbazole and 5.2 mol% of structural units derived from V-PBD. When confirmed, the weight average molecular weight was measured by gel permeation chromatography and found to be 48,000 in terms of polystyrene. Hereinafter, this copolymer is referred to as "polymer (1)".

<Synthesis Example 2 (Copolymer)> In Synthesis Example 1, the amount of N-vinylcarbazole used was 0.8 mol, and V was V.
-Radical polymerization was performed in the same manner as in Synthesis Example 1 except that the amount of -PBD used was changed to 0.2 mol, and the reaction product was subjected to reprecipitation purification. When the obtained copolymer was analyzed, a structural unit 7 derived from N-vinylcarbazole was obtained.
9.5 mol% and structural units derived from V-PBD 20.
It was confirmed that the copolymer was 5% by mol, and the weight average molecular weight was measured by gel permeation chromatography to find that it was 39000 in terms of polystyrene.
Met. Hereinafter, this copolymer is referred to as "polymer (2)".

<Synthesis Example 3 (Copolymer)> In Synthesis Example 1, the amount of N-vinylcarbazole used was 0.5 mol, and V was V.
-Radical polymerization was performed in the same manner as in Synthesis Example 1 except that the amount of -PBD used was changed to 0.5 mol, and the reaction product was subjected to reprecipitation purification. When the obtained copolymer was analyzed, a structural unit 5 derived from N-vinylcarbazole was obtained.
0 mol% and 50 mol% of structural units derived from V-PBD
It was confirmed to be a copolymer consisting of and, and the weight average molecular weight was measured by gel permeation chromatography and found to be 28,000 in terms of polystyrene. Hereinafter, this copolymer is referred to as "polymer (3)".

<Synthesis Example 4 (Hole Transporting Polymer)> In Synthesis Example 1, the amount of N-vinylcarbazole used was 1.
Radical polymerization was carried out in the same manner as in Synthesis Example 1, except that the amount was changed to 0 mol and V-PBD was not used,
Reprecipitation purification was performed on the reaction product. The molecular weight of the obtained polymer was 18,000. Hereinafter, this polymer is referred to as "polymer (4)".

<Synthesis Example 5 (electron transporting polymer)> The same as Synthesis Example 1 except that the amount of V-PBD used was changed to 1.0 mol and N-vinylcarbazole was not used. Then, radical polymerization was carried out, and the reaction product was subjected to reprecipitation purification. The molecular weight of the obtained polymer was 35,000. Hereinafter, this copolymer is referred to as "polymer (5)".

<Synthesis Example 6 (Comparative Copolymer)> Synthesis Example 1
In Example 2, radical polymerization was performed in the same manner as in Synthesis Example 1 except that the amount of N-vinylcarbazole used was changed to 0.4 mol and the amount of V-PBD used was changed to 0.6 mol. Reprecipitation purification was performed. When the obtained copolymer was analyzed, it was found that 39 mol% of structural units derived from N-vinylcarbazole and 61 of structural units derived from V-PBD.
It was confirmed that the copolymer was a copolymer consisting of 1 mol% and the weight average molecular weight was measured by gel permeation chromatography and found to be 40,000 in terms of polystyrene. Hereinafter, this copolymer is referred to as "polymer (6)".

(2) Preparation of phosphorescent agent: Preparation example (1) In a 200 mL three-necked flask equipped with a condenser and a thermometer, under a nitrogen atmosphere, 2 g of μ-chlorobis (2-phenylpyridyl) iridium was added, and 2 -Prepare 3 ml of phenylpyridine and 160 ml of glycerin, and 260 ° C.
It heated above and refluxed for 10 hours. Then, the system is 35 ℃
Then, the reaction solution was poured into 1 L of water, the obtained solution was filtered, extracted with methylene chloride, and further separated by column chromatography. Then, the separated solution was extracted with methylene chloride, 100 mL of methanol was added, the solution was concentrated by an evaporator, and the concentrated solution was cooled to 5 ° C. and recrystallized to obtain yellow fibrous crystals. It was The yield was 70%. The obtained fibrous crystal was subjected to nuclear magnetic resonance spectrum analysis, infrared spectrum spectrum analysis, mass spectrum analysis and elemental analysis, and tris (2-2-phenylpyridyl) represented by the above formula (k) was obtained.
It contains iridium in a proportion of 99.9% by mass, and the dimer content of the impurity compound μ-chlorobis (2-phenylpyridyl) iridium is 0.01% (100 pp.
m) The following iridium complex compounds were confirmed. Hereinafter, this is referred to as "phosphorescent agent (1)".

Example 1 10 g of the polymer (1) obtained in Synthesis Example 1 and 0.5 g of the phosphorescent agent (1) obtained in Preparation Example (1) were mixed with cyclohexane at a solid concentration of 5% by mass. Were added to and mixed with each other, and this was filtered through a filter having a pore size of 2.52 μm to prepare a composition solution in which the luminescent polymer composition was dissolved in an organic solvent. This composition solution is used as a light emitting layer forming coating solution (1).

Example 2 The same as Example 1 except that 10 g of the polymer (2) obtained in Synthesis Example 2 was used instead of 10 g of the polymer (1) obtained in Synthesis Example 1. A composition solution was prepared. This composition solution is used as a coating solution (2) for forming a light emitting layer.

Example 3 The procedure of Example 1 was repeated except that 10 g of the polymer (3) obtained in Synthesis Example 3 was used instead of 10 g of the polymer (1) obtained in Synthesis Example 1. A composition solution was prepared. This composition solution is used as a light emitting layer forming coating solution (3).

Example 4 Instead of 10 g of the polymer (1) obtained in Synthesis Example 1, the polymer (4) obtained in Synthesis Example 4 and the polymer (5) obtained in Synthesis Example 5 were prepared. Other than using 10 g of a polymer mixture obtained by mixing the monomers in each polymer in a molar ratio of 9: 1.
A composition solution was prepared in the same manner as in Example 1. This composition solution is used as a light emitting layer forming coating liquid (4).

Comparative Example 1 The procedure of Example 1 was repeated except that 10 g of the polymer (4) obtained in Synthesis Example 4 was used instead of 10 g of the polymer (1) obtained in Synthesis Example 1. A composition solution was prepared. This composition solution is used as a light emitting layer forming coating solution (5).

Comparative Example 2 The procedure of Example 1 was repeated except that 10 g of the polymer (6) obtained in Synthesis Example 6 was used instead of 10 g of the polymer (1) obtained in Synthesis Example 1. A composition solution was prepared. This composition solution is used as a coating solution (6) for forming a light emitting layer.

<Test Example> (a) Preparation of organic electroluminescence device: An aromatic polymer (trade name: PEDOT manufactured by Bayer Co., Ltd.) was formed on a 5 cm square glass substrate having an ITO film formed on the surface thereof.
P8000) was dissolved in a proportion of 5% by mass, and the solution was applied and heat-treated at 250 ° C. for 30 minutes to form an aromatic polymer layer. Then, the coating liquid (1) for forming a light emitting layer is applied to the surface of the aromatic polymer layer by a spin coater to form a coating layer having a thickness of 70 nm, and this is heat-treated at 200 ° C. for 30 minutes. A luminescent layer made of the luminescent polymer composition was formed.

Then, bathophenanthroline and Cs were vapor-deposited on the surface of the obtained light-emitting layer in a molar ratio of 3: 1, and then an aluminum film having a thickness of 1500 Å was formed on the surface of the vapor-deposited film obtained. By forming, the organic electroluminescent element was produced. This is referred to as an organic EL element (1). Further, an organic electroluminescence device was prepared in the same manner as described above except that the coating solution (2) for forming a light emitting layer to the coating solution (6) for forming a light emitting layer were used in place of the coating solution (1) for forming a light emitting layer. It was made. The organic EL device (2) was prepared using the coating solution (2) for forming a light emitting layer, and the organic E element was prepared using the coating solution (3) for forming a light emitting layer.
L element (3), the one using the light emitting layer forming coating liquid (4) is an organic EL element (4), the one using the light emitting layer forming coating liquid (5) is an organic EL element (5), the light emitting layer forming coating liquid (6)
The organic EL element (6) is defined as follows.

(B) Light emission characteristics: For each of the organic EL element (1) to the organic EL element (6) produced in the above (a),
A light emitting layer was caused to emit light by applying a DC voltage of 25 V with the ITO film as an anode and the aluminum film as a cathode, and the light emission starting voltage, the maximum light emission luminance, the energy efficiency and the light emission efficiency were measured. (C) Durability: For each of the organic EL element (1) to the organic EL element (6) produced in (a) above, the light-emitting layer was caused to emit light under the condition that the applied voltage was constant at 20 V, and An index (hereinafter, referred to as “half-life period” when the half-life value of the organic EL element (6) is set to 100 by measuring the time (half-life period) until the emission brightness becomes half of the initial emission brightness. Called the "index"). The above results are shown in Table 1. In Table 1, "ratio H / E of polymer component" represents the molar ratio of the hole transporting component and the electron transporting component in the polymer component in terms of monomer.

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[Table 1]

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According to the present invention, it is possible to obtain an organic electroluminescence device having high luminous efficiency and excellent durability, and moreover, a functional organic material layer can be easily formed by a wet method. A luminescent polymer composition can be provided.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/10 H05B 33/10 33/14 33/14 B 33/22 33/22 D (72) Inventor Yasunori Negoro 1051 F-term, Kozato-cho, Yamanashi Prefecture (reference) 3K007 AB02 AB03 AB11 AB18 DB03 FA01 4J002 BJ001 EZ006 FD206 GP00 GQ00 GS00 4J100 AQ19P AQ19Q AQ26P BC44Q BC49Q CA04 DA01 JA32 JA43

Claims (9)

[Claims] 1. A phosphorescent agent is contained in a polymer component, and the polymer component comprises a hole transporting component formed from 50 to 99 mol% of a hole transporting monomer, and 50 to 1
A light-emitting polymer composition comprising an electron-transporting component formed of mol% of an electron-transporting monomer. 2. The polymer component is a copolymer comprising 50 to 99 mol% of structural units derived from a hole transporting monomer and 50 to 1 mol% of structural units derived from an electron transporting monomer. The luminescent polymer composition according to claim 1. 3. The polymer component comprises a hole-transporting polymer obtained by polymerizing a hole-transporting monomer and an electron-transporting polymer obtained by polymerizing an electron-transporting monomer. The molar ratio of the electron transporting polymer converted to the monomer is 50:50 to 99:
1. The luminescent polymer composition according to claim 1, which is 1. 4. The light-emitting compound according to claim 2, wherein the hole-transporting monomer is a tertiary aromatic amine derivative and the electron-transporting monomer is an oxadiazole derivative. Combined composition. 5. The luminescent polymer composition according to claim 1, wherein the phosphorescent agent is a complex compound of a metal selected from iridium, platinum and osmium. 6. The luminescent polymer composition according to claim 1, wherein the phosphorescent agent comprises an iridium complex compound represented by the following general formula (1). [Chemical 1] [In the formula, R ¹ and R ² each represent a substituent consisting of a fluorine atom, an alkyl group or an aryl group, and may be the same as or different from each other. m
Is an integer of 0 to 4, and n is an integer of 0 to 4. ] 7. The luminescent polymer composition according to claim 6, wherein the content of the impurity compound represented by the following general formula (X) in the phosphorescent agent is 1000 ppm or less. [Chemical 2] [In the formula, R ¹ and R ² each represent a substituent consisting of a fluorine atom, an alkyl group or an aryl group, and may be the same as or different from each other. m
Is an integer of 0 to 4, and n is an integer of 0 to 4. ] 8. A polymer comprising a hole transporting component formed of 50 to 99 mol% of a hole transporting monomer and an electron transporting component formed of 50 to 1 mol% of an electron transporting monomer. An organic electro-luminescent device comprising a functional organic material layer formed of a light-emitting polymer composition containing a phosphorescent agent as a component, and having a function as a light-emitting layer or a hole-transporting layer. Luminescence element. 9. A polymer comprising a hole transporting component formed of 50 to 99 mol% of a hole transporting monomer and an electron transporting component formed of 50 to 1 mol% of an electron transporting monomer. By applying a solution of a luminescent polymer composition containing a phosphorescent agent in an organic solvent to the surface of a substrate and performing a removal treatment of the organic solvent on the obtained coating film, the function is obtained. A method for manufacturing an organic electroluminescence device, comprising the step of forming a conductive organic material layer.