JP2002302516A - New polymer and light-emitting element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new polymer, and to provide a light emitting element including the polymer and excellent in high-luminance emission, high luminous efficiency and durability. SOLUTION: This polymer is represented by the general formula (1) [wherein, A is a monomer unit having a hole-transportable partial structure and an electron-transportable partial structure in the identical monomer unit; B is a monomer unit having another structure; m is an integer of >=1; n is an integer of >=0; and p and q each represent molar fraction (%), p is 1-100 (%), q is 0-99 (%) and p+q=100 (%)]. The other objective light-emitting element is characterized by including the polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel polymer, and high-luminance and high luminous efficiency containing the polymer.
The present invention relates to a light-emitting element having excellent durability.

[0002]

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

[0003] In this laminated element, an element is formed by evaporating a low molecular organic material as an element material.
As a technique for forming a thin film as used in an organic EL element, various methods such as a vacuum deposition method, a sputtering method, a CVD method, a PVD method, and a coating method using a solvent as described in the above-mentioned documents are used. be able to. The details are described in several publications. One example is ORGANIC ELECTROLUMINESCENT MATERIALS AND DEV
ICES (OPA, Amsterdam, 1997), and organic EL devices and the forefront of industrialization (NTS, 1998). The inventor has studied a method of applying a solution of an organic compound, particularly an organic polymer material, as a thin film forming technique. In the case of an organic polymer material, it is possible to form a thin film with few defects by using the material alone, and the formed thin film has excellent physical and chemical robustness.

However, the electron transporting property, the electron injecting property,
When a material having various functions such as a hole transporting property, a hole injecting property, and a light emitting property is used for a plurality of light emitting elements, in an organic polymer material, phase separation or the like often occurs at the time of mixing, and there is a problem in performance. I understand. Also, it has been found that there is a problem in terms of durability even when a low-molecular compound is used in a mixture with a polymer material.

[0005] In an attempt to improve the above drawbacks, a method of copolymerizing monomers having various functions can be considered. The inventors of the present invention have studied various methods and found that a simple copolymer is not sufficient. It turned out that performance could not be obtained.

In general, in a light emitting device, it is possible to improve the luminous efficiency by using a hole transporting compound and an electron transporting compound in a laminated or the same layer. The inventor has studied an element using a plurality of materials in a coating type organic EL element. As a light-emitting element material used for a coating type light-emitting element, an electron-rich heteroaromatic compound such as pyrrole, thiophene, or furan is effective as a hole-transporting compound. Further, as the electron transporting compound, an electron-deficient heteroaromatic compound containing a plurality of heteroconstituents is effective.
However, as described above, it has been found that when a plurality of functional materials are used in a light-emitting element, only low emission performance can be obtained between organic polymer materials. It was also found that when a low molecular compound was used in a mixture with a polymer material, there was a problem in durability.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
To develop new polymers. And the second
Another object of the present invention is to develop a light-emitting element which emits light with high luminance and good luminous efficiency and has excellent durability.

[0008]

Means for Solving the Problems The present invention has been achieved by the following polymer and light emitting device. 1. A polymer represented by the following general formula (1).

[0009]

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Wherein A represents a monomer unit having a hole transporting partial structure and an electron transporting partial structure in the same monomer unit, B represents a monomer unit having another structure, and m represents 1 Where n is 0
Represents the above integer. p and q each represent a mole fraction (%), p represents 1 to 100 (%), and q represents 0 to 99.
(%). p + q = 100 (%). ) 2. At least one of the hole transporting partial structures contained in A in the general formula (1) is pyrrole, thiophene,
2. The polymer according to the above item 1, which is a monomer unit containing furan or a fused ring derivative thereof. 3. At least one of the electron-transporting partial structures contained in A in the general formula (1) is a monomer unit containing a heterocyclic derivative containing two or more heteroatoms in one ring system. 2. The polymer according to the above 1, wherein 4. 4. The polymer according to any one of the above items 1 to 3, wherein at least one of the monomer units represented by A or B in the general formula (1) contains a ballast group having 4 or more carbon atoms. 5. The polymer according to any one of the above 1 to 4, wherein the monomer unit in the general formula (1) is a vinyl monomer unit. 6. A light-emitting device comprising at least one polymer coated between an anode and a cathode, wherein at least one of the polymers contains the polymer described in any one of (1) to (5). 7. 7. The light-emitting device according to any one of 1 to 6, wherein at least one light-emitting material capable of emitting light from a triplet exciton is used as the light-emitting material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In this specification, “to” indicates a range including numerical values described before and after it as a minimum value and a maximum value, respectively.

First, the polymer represented by the general formula (1) will be described. In the formula, A represents a monomer unit having a hole transporting partial structure and an electron transporting partial structure in the same monomer unit. The monomer unit in the present invention means a repeating unit. Although the hole transporting partial structure and the electron transporting partial structure exist in the monomer unit of the present invention, the order and distance of the two partial structures from the polymer main chain are not particularly limited. As a representative group of compounds having a hole transporting partial structure,
A compound having a tertiary nitrogen atom, that is, an amine derivative is exemplified. Among them, amines substituted by an aromatic hydrocarbon or a heteroaromatic compound are preferable, and particularly, a tertiary amine in which all of the substituents are an aromatic hydrocarbon or a heteroaromatic compound is preferable.

Next, an electron-excess heteroaromatic compound will be described. As an example, if the heteroatom has 1
And a five-membered heteroaromatic, and a compound condensed with each other or with an aromatic hydrocarbon. To list one example, for example, pyrrole, thiophene, furan, indole, carbazole, benzothiophene, benzofuran, dibenzothiophene, dibenzofuran, indolizine and the like can be mentioned. Further, as a compound having a nitrogen atom,
Hydrazone compounds, pyrazolone compounds, hydroxylamine compounds, alkoxyamine compounds and the like can also be used as the hole transporting group.

Among the above-mentioned ring structures, those containing pyrrole, thiophene, furan and their aromatic and heteroaromatic condensed ring derivatives are preferred in the present invention.
Pyrrole, thiophene, and furan are a group of compounds belonging to a group of structures called a π-electron-rich heteroaromatic ring, and the present invention uses a monomer unit containing a derivative thereof.

Examples of the above derivatives include benzo condensates of pyrrole, thiophene, and furan (eg, indole, carbazole, benzothiophene, dibenzothiophene, benzofuran, dibenzofuran, etc.).
Other examples include indolidine, thienothiophene, thienopyrrole, and isoindole. Among these, in the present invention, a monomer unit containing a pyrrole derivative is preferable, and carbazole is particularly preferably used.

The electron transporting partial structure will be described. As the group having an electron transporting property, compounds having various structures are known in the art, and a heteroaromatic ring is particularly used as an effective group.

The heteroaromatic ring includes a nitrogen-containing 5-membered heteroaromatic compound having two or more heteroatoms. Examples include pyrazole, imidazole, oxazole, thiazole, triazole (1,2,3-
And 1,2,4-), tetrazole, oxadiazole (1,2,
4-, 1,2,5- and 1,3,4-), thiadiazole (1,2,4-, 1,
2,5- and 1,3,4-). Compounds condensed with each other or with an aromatic hydrocarbon can be used in the same manner.

Similarly, examples of the heteroaromatic ring include nitrogen-containing 6-membered heteroaromatic compounds lacking ring electrons. Examples thereof include pyridine, pyridazine, pyrimidine, pyridazine, triazine and the like. As for these compounds, compounds which are condensed with each other or with aromatic hydrocarbons, 5-membered and 6-membered heteroaromatics can also be used. Examples thereof include quinazoline and quinoxaline.

In the present invention, the heteroaromatic ring is preferably a heteroaromatic ring containing a heterocyclic derivative containing two or more heteroatoms in one ring system. Examples of such a hetero ring include imidazole, pyrazole, pyridazine, pyrimidine, pyrazine, oxazole, thiazole, isoxazole, isothiazole, triazole, tetrazole, oxadiazole, thiadiazole, and the like, and a condensed ring thereof. In the present invention, among these, 1,3,4-oxadiazole derivatives are particularly preferably used.

In the present invention, the polymer having the two properties of the hole transporting property and the electron transporting property described above uses a polymer derived from a monomer contained in the same unit.

B in the general formula (1) represents a monomer unit having a structure other than A. The polymerization mode of the monomer unit when forming the polymer can be formed by various polymerization reactions such as vinyl polymerization, polycondensation, ring-opening polymerization, and aryl coupling polymerization. A polymer forming reaction by polymerization is preferred. As the monomer unit of B, a vinyl polymerized monomer (for example, styrene, acrylate, methacrylate, vinyl ether, substituted allyl, etc.) is preferable.

As the B unit, a monomer unit having only a hole transporting property or a monomer unit having only an electron transporting property can be used.

In the polymer of the present invention, a polymer in which at least one monomer unit of A and B is substituted with a ballast group having 4 or more carbon atoms is preferably used. The ballast group refers to an oil-soluble group having 4 or more carbon atoms, and is introduced to solubilize the polymer of the present invention in an organic solvent. Examples of the ballast group include an alkyl group, an alkoxy group, an ester group, an amide group, and a sulfonamide group. In addition, the case where these have two or more bonds and are connected is also included. The ballast group used in the present invention is preferably an alkyl group or an alkoxy group, and has 4 or more carbon atoms, preferably 8 to 20 carbon atoms.
In the following, both linear and branched ones can be used.

In the general formula (1), m represents an integer of 1 or more, and n represents an integer of 0 or more. p represents an integer of 1 to 100, and q represents an integer of 0 to 99. p + q = 100. m
Are preferably 1 to 3, and n is preferably 0 to 2, and more preferably m is 1 to 2 and n is 0. p is preferably 10 to 100, and q is preferably 0 to 90.
And more preferably p is 50 to 100 and q is 0 to 5
0.

The monomer unit of the present invention can be substituted with various substituents other than those having a function as a ballast group. Examples are listed below. Halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, formyl group, or substituted or unsubstituted alkyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms) For example, a methyl group, a t-butyl group,
And a cyclohexyl group. ), An alkenyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 15 carbon atoms)
It is. For example, vinyl group, 1-propenyl group, 1-butene
-2-yl group, cyclohexen-1-yl group and the like. ), An alkynyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 15 carbon atoms. For example, an ethynyl group, 1-
And a propynyl group. ), An aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms, such as phenyl, tolyl, xylyl, naphthyl, biphenylyl, and pyrenyl).

A heterocyclic group (preferably a 5- or 6-membered ring, which may be condensed with another ring.
Examples include a nitrogen atom, an oxygen atom, and a sulfur atom. It preferably has 2 to 30 carbon atoms, more preferably 2 to 15 carbon atoms. For example, a pyridyl group, a piperidyl group, an oxazolyl group, an oxadiazolyl group, a tetrahydrofuryl group, a thienyl group and the like can be mentioned. ), Primary to tertiary amino groups (amino group, alkylamino group, arylamino group, dialkylamino group, diarylamino group, alkylarylamino group, heterocyclic amino group, bisheterocyclic amino group, etc., preferably tertiary amino group , and the 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms. such as dimethylamino group, diphenylamino group, and a phenyl naphthyl amino group.), an imino group (-CR ₁₁ = NR ₁₂ or -N
= Group represented by CR ₁₃ R ₁₄ . Here, R _{11 to} R ₁₄ are groups selected from a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group and a primary to tertiary amino group. Preferably 1 to 30 carbon atoms, more preferably 1 to 30 carbon atoms
It is 15. ),

An alkoxy group (preferably having 1 to 30 carbon atoms;
More preferably, it has 1 to 15 carbon atoms. For example, a methoxy group, an ethoxy group, a cyclohexyloxy group and the like can be mentioned. ), An aryloxy group (preferably having 6 to 3 carbon atoms)
It has 0, more preferably 6 to 15 carbon atoms. For example, a phenoxy group, a 1-naphthoxy group, a 4-phenylphenoxy group and the like can be mentioned. ), An alkylthio group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms.
Examples thereof include a methylthio group, an ethylthio group, and a cyclohexylthio group. ), An arylthio group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms.
Examples include a phenylthio group and a tolylthio group. ) Carbonamide group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms, for example, acetamido group, benzoylamide group, N-methylbenzoylamide group, etc.), sulfonamido group ( Preferably carbon number
It has 1 to 30, more preferably 1 to 15 carbon atoms. For example, methanesulfonamide group, benzenesulfonamide group, p-
And a toluenesulfonamide group. ), A carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, an unsubstituted carbamoyl group, a methylcarbamoyl group, a dimethylcarbamoyl group,
Phenylcarbamoyl group, diphenylcarbamoyl group,
And a dioctylcarbamoyl group. ),

Sulfamoyl group (preferably having 1 to 3 carbon atoms)
It has 0, more preferably 1 to 15 carbon atoms. Examples include an unsubstituted sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group, diphenylsulfamoyl group, dioctylsulfamoyl group, and the like. ), An alkylcarbonyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms).
For example, an acetyl group, a propionyl group, a butyroyl group,
Lauroyl group and the like. ), An arylcarbonyl group (preferably having 6 to 30 carbon atoms, more preferably having 6 carbon atoms)
~ 15. Examples include a benzoyl group and a naphthoyl group. ), An alkylsulfonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms, such as a methanesulfonyl group and an ethanesulfonyl group), and an arylsulfonyl group (preferably having 6 carbon atoms). -30, more preferably 6-15 carbon atoms.
Examples thereof include a benzenesulfonyl group, a p-toluenesulfonyl group, and a 1-naphthalenesulfonyl group. ),

An alkoxycarbonyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example,
Examples thereof include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. ), An aryloxycarbonyl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms, such as a phenoxycarbonyl group and a 1-naphthoxycarbonyl group).
An alkylcarbonyloxy group (preferably having 1 to 3 carbon atoms)
It has 0, more preferably 1 to 15 carbon atoms. For example, an acetoxy group, a propionyloxy group, a butyroyloxy group and the like can be mentioned. ), An arylcarbonyloxy group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms, such as a benzoyloxy group and a 1-naphthoyloxy group), a urethane group (preferably having number
It has 1 to 30, more preferably 1 to 15 carbon atoms. For example, a methoxycarbonamide group, a phenoxycarbonamide group, a methylaminocarbonamide group and the like can be mentioned. ), A ureido group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. Examples thereof include a methylaminocarbonamide group, a dimethylaminocarbonamide group, and a diphenylaminocarbonamide group). And a carbonic ester group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms, such as a methoxycarbonyloxy group and a phenoxycarbonyloxy group). Hereinafter, specific examples of preferred monomer units and subsequent specific synthesis reaction examples are shown together with routes, but the present invention is of course not limited thereto.

[0030]

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[0031]

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(Specific method of synthesizing monomer)

[0033]

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1) Synthesis of Monomer A-1 (Synthesis of Compound X-1) In a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser, 300 ml of tetrahydrofuran, 50.1 g (0.3 mol) of carbazole, 4-bromomethylbenzoate 68.9 g (0.3 mol) of acid methyl ester was charged. While stirring the contents using a magnetic stirrer, 33.6 g (0.3 mol) of potassium-t-butoxide was gradually added thereto so that the internal temperature did not exceed 30 ° C. After completion of the addition, the mixture was stirred at room temperature for 1 hour, and reacted under reflux condition for 5 hours. After completion of the reaction, the reaction mixture was poured into 5 liters of water to precipitate crystals. The crystals were recrystallized from ethanol to obtain 85 g of compound X-1 as crystals.

(Synthesis of Compound X-2) In a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser, 126 g (0.4 mol) of compound X-1, 350 ml of ethanol and 200 ml of hydrazine monohydrate were charged. The reaction was carried out for 5 hours under reflux conditions while stirring using a magnetic stirrer. After completion of the reaction, the reaction mixture was poured into 5 liters of water to precipitate crystals. The crystals were recrystallized from ethanol to obtain 110 g of compound X-2.

(Synthesis of Compound X-3) In a 2000 ml three-necked flask equipped with a thermometer and a reflux condenser, 126 g (0.4 mol) of Compound X-2 and 600 ml of N, N-dimethylacetamide were charged. While stirring the contents using a magnetic stirrer, an ice-methanol bath was attached thereto, and the internal temperature was lowered to 0 ° C. Here, 88 g (0.4 mol) of 4-bromobenzoyl chloride was gradually added dropwise so that the internal temperature did not exceed 20 ° C. The reaction exothermed instantaneously and insoluble white crystals precipitated. After the completion of the dropwise addition, the reaction was further performed at room temperature for 30 minutes. After completion of the reaction, 600 ml of acetonitrile was added to completely precipitate crystals of the product. The precipitated crystals were separated by filtration under reduced pressure using a Nutsche. The crystals were washed with acetonitrile to obtain 200 g of Compound X-3 as crystals.

(Synthesis of Compound X-4) A 2000 ml three-necked flask equipped with a thermometer and a reflux condenser was charged with 200 g of the compound X-3 crystal and 1000 g of polyphosphoric acid.
Heated using an oil bath. Initially the contents are viscous, but the internal temperature
It becomes fluid from around 100 ° C. While stirring this mixture using a stirring spring, the internal temperature was 160
The reaction was carried out for 5 hours at ~ 180 ° C. After the completion of the reaction, when the internal temperature had dropped to around 100 ° C., the contents were added to cold water. As the temperature rose, white crystals precipitated.
The crystals were recrystallized from a mixed solvent of tetrahydrofuran / ethanol to obtain 147 g of compound X-4 as crystals.

(Synthesis of Monomer A-1) In a 2000 ml three-necked flask equipped with a thermometer and a reflux condenser, 72 g (0.3 mol) of the compound X-4, 2,6-
7 g of di-t-butyl-4-methylphenol, 1 g of triphenylphosphine, 5 g of 10% by mass palladium-supported activated carbon catalyst, 4-g
74 g (0.5 mol) of phenylboronic acid, 106 g of sodium carbonate
(1.0 mol), diethylene glycol dimethyl ether 50
0 ml and 50 ml of water were charged and reacted under reflux conditions for 5 hours while stirring using a stirring spring. After the reaction was completed, 500 ml of diethylene glycol dimethyl ether was further added thereto, and the catalyst was removed by filtration under reduced pressure using a hot Nutsche lined with celite. Methanol 1 in the filtrate
Addition of 1 liter resulted in precipitation of product crystals, which were filtered off after cooling. This crude crystal is treated with tetrahydrofuran /
Recrystallization from a mixed solvent of ethanol gave monomer A-1.
77 g of crystals were obtained.

Further, specific examples of polymer compounds (polymers preferably used in the present invention) formed by the polymerization reaction of the above monomers are shown below. The present invention is of course not limited by this specific example. In the chemical structural formulas shown below, the number at the lower right of the parenthesis of the polymer main chain part means a mole fraction (%), and unless otherwise specified, it means 100%, that is, 1.

[0040]

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[0041]

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[0042]

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[0043]

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(Specific Method for Synthesizing Polymer)

[0045]

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(Synthesis of Polymer P-1) In a 500 ml three-necked flask equipped with a thermometer, a gas inlet tube and a reflux condenser, 10 g of monomer A-1 and 200 ml of toluene were placed.
And passed through a stream of nitrogen. While stirring the contents using a magnetic stirrer, the internal temperature was controlled at 70 ° C. Here azobisisobutyronitrile (AIBN) as initiator
Was added 5 times every 1 hour in 0.1 g portions. When the polymerization reaction was continued for another 3 hours after the addition, the TLC plate was checked to confirm that all the monomers had disappeared. After filtering the polymer solution, the polymer solution was poured into 3 liters of methanol to precipitate and purify the polymer, and the precipitated polymer was separated by filtration and dried. In this way, 9.9 g of polymer P-1 was obtained as a flake-like solid.

The polymer that can be used in the present invention can be derived into a polymer by a polymerization method such as radical polymerization, ionic polymerization, polycondensation, or ring-opening polymerization. Among them, such as radical polymerization and ionic polymerization,
Polymers obtained by vinyl polymerization are preferably used. These polymerization methods are described in "Experimental Methods for Polymer Synthesis".
Details are described in Otsu-Kinoshita co-authored by Kagaku Dojin (1972). Weight average molecular weight (M
w) is 1000 to 10000000, preferably 2000 to 100000
0, particularly preferably 5,000 to 500,000. Further, the polymer of the present invention can be used as an organic light emitting device material in combination with other organic materials and inorganic materials. The organic material used in combination may be a low molecular organic material or a polymer.

The polymer synthesized from the monomer of the present invention can be used as an organic light emitting device material as any of a hole injecting material, a hole transporting material, a light emitting material, an electron transporting material, and an electron injecting material.

The polymer used in the present invention may be used alone or as a mixture with another polymer. Furthermore, it is also possible to use a mixture with a low molecular weight compound.

The present invention provides a method for manufacturing a light emitting device in which two or more light emitting device materials are applied as a thin film between an anode and a cathode. In particular, the present invention relates to a method for manufacturing an organic light emitting device using an organic material as a light emitting device material. According to the method of the present invention, after applying at least two or more layers of element material, the element material of the applied thin film is modified by applying physical or chemical post-treatment to improve the function as a light emitting element material. It is to let.

As the light emitting device material to be coated, a hole injecting material, a hole transporting material, a hole blocking material, an electron injecting material, an electron transporting material, an electron blocking material, a light emitting material, and the like are used. Any material may be used as long as the material is suitable. In the present invention, organic compounds are preferably used as the above various light emitting element materials.

When the polymer of the present invention is used as an organic light emitting device material, the organic light emitting device emits light from a singlet exciton, emits light from a triplet exciton (phosphorescent compound), One that emits light from both,
Although any of the light emitting materials can be used, a combination with a light emitting material containing light emission from a triplet exciton is particularly preferably used from the viewpoint of light emission efficiency.

As the luminescent material used in the present invention, at least one of an orthometalated metal complex and a porphyrin metal complex which are phosphorescent compounds is preferably used.
Orthometallated metal complexes are more preferably used.

The orthometalated metal complex used in the present invention will be described. The ortho-metalated metal complex is described in, for example, "Organic Metal Chemistry-Fundamentals and Applications-", p.
Shokabosha, written by Akio Yamamoto 1982, Photochemis
try and Photophysics of Coordination Compounds '' p
71-p77, p135-p146 Springer-Verlag H. Yersin 19
It is a general term for a group of compounds described in 1987 and the like.
As the central metal of the metal complex, any transition metal can be used. In the present invention, among them, rhodium, platinum, gold, iridium, ruthenium, palladium and the like can be preferably used. Of these, iridium is more preferred. The specific description and the compound examples of the ortho-metalated metal complex are described in Japanese Patent Application No. 2000-254171, paragraphs 0152 to 0180.

The valence of the metal of the orthometalated metal complex is not particularly limited, but is preferably trivalent when iridium is used. The ligand of the orthometalated metal complex is not particularly limited as long as it can form an orthometallated metal complex. For example, an aryl group-substituted nitrogen-containing aromatic hetero ring derivative (the substitution position of an aryl group is on a carbon adjacent to a nitrogen-containing aromatic hetero ring nitrogen atom, and examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, Examples of the nitrogen-containing aromatic heterocycle include pyridine, pyrimidine, pyrazine, pyridazine, quinoline, isoquinoline, quinoxaline, phthalazine, quinazoline, naphthyridine, cinnoline, perimidine, phenanthroline, pyrrole, imidazole, and pyrazole. , Oxazole, oxadiazole, triazole,
Thiadiazole, benzimidazole, benzoxazole, benzothiazole, phenanthridine and the like),

Heteroaryl group-substituted nitrogen-containing aromatic heterocyclic derivative (the substitution position of the heteroaryl group is on the carbon adjacent to the nitrogen-containing aromatic heterocycle nitrogen atom. Group, thiophenyl group, furyl group, etc.), 7,8-benzoquinoline derivative, phosphinoaryl derivative, phosphinoheteroaryl derivative, phosphinoxyaryl derivative, phosphinoxyhetero An aryl derivative, an aminomethylaryl derivative, an aminomethylheteroaryl derivative and the like can be mentioned. Of these, aryl-substituted nitrogen-containing aromatic heterocyclic derivatives, heteroaryl-substituted nitrogen-containing aromatic heterocyclic derivatives, and 7,8-benzoquinoline derivatives are preferable, and phenylpyridine derivatives, thiophenylpyridine derivatives, and 7,8-benzoquinoline Derivatives are more preferred, thiophenylpyridine derivatives,
7,8-Benzoquinoline derivatives are more preferred.

The porphyrin metal complex used in the present invention is preferably a platinum complex, more preferably a divalent platinum complex.

As an organic light emitting device in which light emission from a triplet exciton is observed, an iridium complex (Ir (ppy) ₃ : Tris-Or
tho-Metalated Complex of Iridium (III) with 2-Pheny
A green light-emitting device utilizing light emission from lpyridine) has been reported (Applied Physics Letters 75, 4 (1999)).
It has been reported that this device achieved an external quantum yield of 8%, surpassing the external quantum yield of 5%, which was said to be the limit of the conventional device.

Next, a light emitting device containing the compound of the present invention will be described. The method for forming the organic layer of the light-emitting element containing the compound of the present invention is not particularly limited, and a method such as resistance heating evaporation, electron beam, sputtering, molecular lamination, coating, or an inkjet method is used. From the viewpoint of characteristics and production, resistance heating evaporation and coating are preferred.

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

The light emitting device of the present invention comprises a polymer represented by the general formula (1) and at least one kind of the polymer. In order to provide a light-emitting device having high luminance emission, high luminous efficiency, and excellent durability, the organic compound layer of the light-emitting device preferably contains the polymer in an amount of 0.01 to 100% by mass, more preferably 1 to 100% by mass. % By mass.

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

As the anode, a layer formed on a soda lime glass, an alkali-free glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass in order to reduce ions eluted from the glass. Further, when soda lime glass is used, it is preferable to use a glass coated with a barrier coat such as silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength. When glass is used, the thickness is usually 0.2 mm or more, preferably 0.7 mm or more.

Various methods are used for producing an anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating evaporation method, a chemical reaction method (sol-
The film is formed by a method such as a gel method) or coating a dispersion of indium tin oxide. The anode can be washed or otherwise treated to lower the driving voltage of the device or increase the luminous efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment and the like are effective.

The cathode supplies electrons to the electron injecting layer, the electron transporting layer, the light emitting layer and the like. The cathode has good adhesion and ionization potential between the negative electrode and the adjacent layer such as the electron injecting layer, the electron transporting layer and the light emitting layer. It is selected in consideration of stability and the like. As a material for the cathode, a metal, an alloy, a metal halide, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples thereof include an alkali metal (for example, L
i, Na, K, Cs, etc.) and their fluorides, alkaline earth metals (eg, Mg, Ca, etc.) and their fluorides, gold,
Silver, lead, alnium, sodium-potassium alloy or mixed metal thereof, lithium-aluminum alloy or mixed metal thereof, magnesium-silver alloy or mixed metal thereof, indium, rare earth metal such as ytterbium, and the like, preferably A material having a work function of 4 eV or less, more preferably aluminum, a lithium-aluminum alloy or a mixed metal thereof, a magnesium-silver alloy or a mixed metal thereof, or the like.

The cathode may have not only a single-layer structure of the above compound and mixture, but also a laminated structure containing the above compound and mixture. The thickness of the cathode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm to 1 μm.

The cathode is manufactured by a method such as an electron beam method, a sputtering method, a resistance heating evaporation method, and a coating method. The metal can be evaporated alone or two or more components can be evaporated simultaneously. Further, an alloy electrode can be formed by depositing a plurality of metals at the same time, or an alloy prepared in advance may be deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

The material of the light emitting layer is capable of injecting holes from an anode, a hole injection layer, or a hole transport layer and applying electrons from a cathode, an electron injection layer, or an electron transport layer when an electric field is applied. Any material can be used as long as it can form a layer having a function, a function of transferring injected charges, and a function of providing a field of recombination of holes and electrons to emit light. Preferably, the light emitting layer contains the amine compound of the present invention, but other light emitting materials can also be used. For example, benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, perylene derivatives, perinone derivatives, oxadiazole derivatives, aldazine derivatives , Pyrazine derivative, cyclopentadiene derivative,
Bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styrylamine derivatives, aromatic dimethylidin compounds, various metal complexes represented by 8-quinolinol derivative metal complexes and rare earth complexes, Polymer compounds such as polythiophene, polyphenylene, and polyphenylenevinylene are exemplified. Although the thickness of the light emitting layer is not particularly limited, it is usually 1 nm to 5 nm.
It is preferably in the range of μm, more preferably 5 nm to
It is 1 μm, and more preferably 10 nm to 500 nm.

The method for forming the light emitting layer is not particularly limited, but includes resistance heating evaporation, electron beam, sputtering, molecular lamination, coating (spin coating, casting, dip coating, etc.), and LB method. And a method such as an ink-jet method, and preferably a resistance heating evaporation and a coating method.

The material of the hole injection layer and the hole transport layer has one of a function of injecting holes from the anode, a function of transporting holes, and a function of blocking electrons injected from the cathode. Should be fine. Specific examples thereof include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, and styryl anthracene derivatives , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds,
Examples thereof include poly (N-vinylcarbazole) derivatives, aniline-based copolymers, thiophene oligomers, and conductive polymer oligomers such as polythiophene. The thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 5 μm.
00 nm. The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

The hole injecting layer and the hole transporting layer may be formed by a vacuum deposition method, an LB method, an inkjet method, or a method of dissolving or dispersing the hole injecting / transporting agent in a solvent and coating (spin coating method, Casting method, dip coating method, etc.). In the case of the coating method, it can be dissolved or dispersed together with the resin component. Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N -Vinyl carbazole), hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, A
Examples include BS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, and silicone resin.

The material of the electron injecting layer and the electron transporting layer is not limited as long as it has a function of injecting electrons from the cathode, a function of transporting electrons, or a function of blocking holes injected from the anode. Good. Specific examples thereof include triazole derivatives, oxazole derivatives, oxadiazole derivatives,
Heterocyclic tetracarboxylic anhydrides such as fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbidiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene perylene, and phthalocyanines And various metal complexes represented by metal complexes of derivatives, 8-quinolinol derivatives, metal phthalocyanines, and metal complexes having benzoxazole or benzothiazole as ligands. The thickness of the electron injection layer and the electron transport layer is not particularly limited, but is usually 1 nm to 5 μm.
m, more preferably 5 nm to 1
μm, and more preferably 10 nm to 500 nm. The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-mentioned materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

The electron injecting layer and the electron transporting layer can be formed by a vacuum deposition method, an LB method, an ink-jet method, or a method of coating by dissolving or dispersing the electron injecting / transporting agent in a solvent (spin coating, casting, A dip coating method or the like is used. In the case of the coating method,
It can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified for the hole injection / transport layer can be applied.

As the material of the protective layer, any material may be used as long as it has a function of preventing a substance that promotes element deterioration such as moisture or oxygen from entering the element. As a specific example,
In, Sn, Pb, Au, Cu, Ag, Al, Ti, N
metal such as i, MgO, SiO, SiO ₂ , Al ₂ O ₃ , G
eO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O 3, T
metal oxides such as iO ₂ , MgF ₂ , LiF, AlF ₃ , C
aF ₂ metal fluorides such as, polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, poly-dichloro-difluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, At least one with tetrafluoroethylene
A copolymer obtained by copolymerizing a monomer mixture containing a kind of comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0.1% The following moisture-proof substances are listed.

The method for forming the protective layer is not particularly limited. For example, a vacuum deposition method, a sputtering method, a reactive sputtering method, an MBE (molecular beam epitaxy) method, a cluster ion beam method, an ion plating method, a plasma polymerization method ( High-frequency excitation ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, and inkjet method can be applied.

[0076]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited by these. Example 1 A transparent support substrate was made of ITO having a thickness of 150 nm formed on a 25 mm × 25 mm × 0.7 mm glass substrate (manufactured by Tokyo Sanyo Vacuum Co., Ltd.). This transparent support substrate was etched and washed.
After spin-coating a poly [(3,4-ethylenedioxy) -2,5-thiophene] polystyrenesulfonic acid dispersion (Bayer: Baytron P solid content 1.3%) on this substrate,
Vacuum drying was performed at 150 ° C. for 2 hours to form a coating layer having a thickness of 100 nm. On top of this, a poly (N-vinyl carbazole)
(PVK)) 40mg, PBD (2- (4'-t-butylphenyl) -5- (4 ''-
(Phenyl) phenyl) -1,3,4-oxadiazole) 12 mg,
Coumarin-6 1mg as light emitting material, 1,2-dichloroethane 2m
The solution dissolved in l was spin-coated. The thickness of this coating film was about 120 nm. A mask patterned on the organic thin film (a mask with a light emitting area of 5 mm x 5 mm) is installed,
In a vapor deposition apparatus, magnesium: silver = 10: 1 was co-deposited at 250 nm, and then silver was vapor-deposited at 300 nm, whereby an element 101 was formed.

The light emission characteristics of the device obtained above were measured using a source measure unit 2400 manufactured by Toyo Technica to apply a constant DC voltage to the EL device to emit light, and the luminance was measured by a luminance meter BM-8 manufactured by Topcon Corporation. The emission wavelength was measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. The emission luminance of the element 101 at an applied voltage of 19 V is 1500 cd / m ² ,
The maximum brightness (Lmax) when the voltage is further increased is 3400 cd
/ m ² . In addition, after measuring the emission spectrum, the external quantum efficiency of light emission calculated from the ratio of the input energy value to the value obtained by integrating the light emission energy of the entire spectral region was evaluated. The quantum efficiency (Qexmax) was 0.77%.

With respect to the element 101, except that the light emitting material of the light emitting layer and other materials were changed as described in Table 1,
Elements 102 to 123 having exactly the same element configuration as 1 were produced. Evaluation results of the light emission characteristics of these devices (specified as (initial) in the table) and the light emission characteristics after the devices were stored at 60 ° C. for one week in a nitrogen atmosphere (specified as (storage) in the table)
Are shown in Table 2.

[0079]

[Table 1]

[0080]

[Table 2]

[0081]

Embedded image

From the table, as compared with the light-emitting elements 101 to 104 using coumarin-6 as a light-emitting material, the elements 105 to 110 using the polymer of the present invention showed an initial light emission luminance and a light emission after storage under heating conditions. It can be seen that both light emission luminances are excellent. In addition, in the results of 111 to 123, which are devices using a light emitting material capable of emitting light from a triplet excited state, comparing the comparative examples 111 to 116 with the devices using the polymer of the present invention of 117 to 123, Luminance and luminous efficiency are both improved more than in the case of coumarin-6, and using a luminescent material that can emit light from a triplet excited state together with the polymer of the present invention is effective for luminous luminance and luminous efficiency. You can see that there is.

[0083]

It has been clarified that a light emitting device having high luminance and high luminous efficiency can be produced by containing the polymer of the present invention. Further, it is possible to provide an element which has a small luminance reduction after high-temperature storage and excellent durability.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (reference) H05B 33/14 H05B 33/14 BF term (reference) 3K007 AB00 AB02 AB03 AB13 BB05 CA01 CB01 CB03 DB03 EB00 FA01 4J100 AB07P AB07Q AB07R AL03Q AQ06P AQ06Q AQ06R BC43P BC43Q BC43R BC44P BC65P BC65Q BC65R BC73P BC79P BC79Q BC79R BC83P

Claims (7)

[Claims] 1. A polymer represented by the following general formula (1). Embedded image (Wherein, A represents a monomer unit having a hole transporting partial structure and an electron transporting partial structure in the same monomer unit. B represents a monomer unit having another structure. M is an integer of 1 or more.) And n represents an integer of 0 or more, p and q each represent a mole fraction (%), p represents 1 to 100 (%), and q represents 0 to 99 (%).
+ q = 100 (%). ) 2. A method according to claim 1, wherein at least one of the hole transporting partial structures contained in A in the general formula (1) is a monomer unit containing pyrrole, thiophene, furan, or a fused ring derivative thereof. The polymer of claim 1. 3. A method according to claim 1, wherein at least one of the electron-transporting partial structures contained in A in the general formula (1) has two ring structures in one ring system.
The polymer according to claim 1, which is a monomer unit containing a heterocyclic derivative containing one or more heteroatoms. 4. The polymer according to claim 1, wherein at least one of the monomer units represented by A or B in the general formula (1) contains a ballast group having 4 or more carbon atoms. 5. The method according to claim 1, wherein the monomer unit in the general formula (1) is a vinyl monomer unit.
The polymer according to any one of claims 1 to 4, wherein 6. A light emitting device comprising at least one polymer coated between an anode and a cathode, wherein at least one of the polymers contains the polymer according to claim 1. Light emitting element. 7. The light emitting device according to claim 1, wherein at least one light emitting material capable of emitting light from a triplet exciton is used as the light emitting material.