JP2002363227A - New polymer and luminescent element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a new polymer and a luminescent element which contains the polymer and has high luminance emission and high luminous efficiency and excellent durability. SOLUTION: The polymer is represented by the formula (1) (Am )p -(Bn )q -(Ck )r (A is a monomer unit containing pyrrole, thiophene, furan and its aromatic and heteroaromatic condensed ring derivatives; B is a monomer unit containing a heterocyclic derivative containing two or more hetero atoms on one ring system; C is a monomer unit containing a structure except those of B and C; (m) and (n) are each an integer of >=1; (k) is an integer of >=0; (p) and (q) are each a mol fraction (%) and are each 1-99; (r) is 0-98(%), p+q+5=100(%); at least one monomer unit of A, B and C is substituted with a >=4C ballast group).

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, particularly to an organic light-emitting element.

[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.

Japanese Patent Application Laid-Open No. 2000-286056 discloses an organic light emitting device material containing a carbazole derivative. JP
No. 9-255725 discloses that a polymer containing an oxadiazole group is used as an electron transporting material of an organic light-emitting device, and only discloses a copolymer with a carbazole derivative.

As an attempt to remedy the above-mentioned drawbacks, a method of copolymerizing monomers having various functions can be considered. However, when the inventor examined various methods, it was found that a simple copolymer was not sufficient. It turned out that performance could not be obtained.

In general, in a light-emitting element, the luminous efficiency can be improved by laminating a hole transporting compound and an electron transporting compound in the same layer or in 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.

[0008]

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.

[0009]

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).

[0010]

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(Wherein, A represents a monomer unit containing at least one selected from indole, carbazole, dibenzothiophene, benzofuran, and dibenzofuran. B represents imidazole, pyrazole,
Represents a monomer unit containing at least one selected from pyridazine, pyrimidine, pyrazine, oxazole, thiazole, isoxazole, isothiazole, triazole, tetrazole, oxadiazole and thiadiazole. B is imidazole, pyrazole, pyridazine, pyrimidine, pyrazine, oxazole, thiazole, isoxazole, isothiazole,
Represents a monomer unit containing at least one selected from triazole, tetrazole, oxadiazole and thiadiazole. C represents a monomer unit having another structure. m and n represent an integer of 1 or more, and k represents an integer of 0 or more. p, q, and r each mean a mole fraction (%), p and q represent 1 to 99 (%), and r
Represents 0 to 98 (%). p + q + r = 100 (%). In at least one monomer unit of A, B, and C, at least one selected from an alkyl group, an alkoxy group, an ester group, an amide group, and a sulfonamide group having 4 to 20 carbon atoms is substituted. I have. ) 2. Wherein at least one of A in the general formula (1) is a monomer unit having a carbazole skeleton, and at least one of B is a monomer unit having a 1,3,4-oxadiazole skeleton. The polymer as described. 3. 3. The polymer according to the above item 1 or 2, wherein each of A, B and C in the general formula (1) is a vinyl monomer unit. 4. 4. The polymer according to any one of the above items 1 to 3, wherein the polymer represented by the general formula (1) is a polymer represented by the following general formula (2).

[0012]

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(In the formula, A ′ represents carbazole, and may be bonded to the main chain and any of the 1- to 9-positions; B ′ is 1,3,
This is a partial structure containing a 4-oxadiazole skeleton, and C ′ represents a monomer unit having a structure other than A ′ and B ′. x, y, and z each represent a mole fraction (%);
And y represent 1 to 99 (%), r represents 0 to 98 (%), and p + q + r = 100 (%). A ', B', C '
Is substituted with a ballast group having 4 or more carbon atoms. )

5. A light emitting device having a layer containing at least one polymer between an anode and a cathode, wherein at least one of the polymers contains the polymer according to any one of the above 1 to 4. element. 6. 6. The light-emitting element according to the item 5, wherein at least one light-emitting material capable of emitting light from triplet excitons is used as the light-emitting material.

[0015]

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 (hereinafter, referred to as the polymer of the present invention). The polymer is composed of three monomer units of A, B and C, and r is 0 (p + q + r = 100 (%))
The polymer of the present invention is characterized in that it always contains the monomer units of A and B as main components. In addition, the monomer unit in the present invention (hereinafter, referred to as the monomer of the present invention) means a repeating unit.

In the polymer represented by the general formula (1), A represents a monomer unit containing pyrrole, thiophene, furan and aromatic and heteroaromatic condensed ring derivatives thereof. 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. As the derivative, first, a benzo condensate of pyrrole, thiophene, and furan (for example, indole,
Carbazole, benzothiophene, dibenzothiophene, benzofuran, dibenzofuran, etc.). Other examples include indolizine, 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.

B represents a monomer unit containing a heterocyclic derivative containing two or more heteroatoms in one ring system. Such heterocycles include imidazole, pyrazole, pyridazine, pyrimidine, pyrazine, oxazole, thiazole, isoxazole, isothiazole, triazole, tetrazole, oxadiazole,
Thiadiazole and the like and a condensed ring thereof can be exemplified. In the present invention, among these, 1,3,4-oxadiazole derivatives are particularly preferably used.

C represents a monomer unit having a structure other than A and B. 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. C
As the monomer unit, a vinyl polymerized monomer (for example, styrene, acrylate, methacrylate, vinyl ether, substituted allyl, etc.) is preferable.

In the polymer of the present invention, a polymer wherein at least one monomer unit of A, B and C 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 various organic solvents such as non-halogen and halogen. Examples of the ballast group include an alkyl group, an alkoxy group, an ester group, an amide group, a sulfonamide group and the like. The alkyl group, the alkoxy group (—OR;
The above alkyl groups) and ester groups (—COOR; R is an alkyl group having 3 or more carbon atoms) are preferable, and an alkyl group is more preferable. Also, these have two or more bonds,
This includes the case where they are linked. The ballast group used in the present invention is preferably an alkyl group or an alkoxy group, and has 4 or more, preferably 8 or more and 20 or less, and any of linear and branched can be used.

Since the polymer of the present invention has a ballast group, it can be dissolved not only in a halogen-based solvent but also in a non-halogen-based solvent such as toluene. However, a carbazole-based polymer having no ballast group has a low solubility in a non-halogen-based solvent, and thus it is difficult to form a film. A production method that does not use a non-halogen solvent, which is a solvent that can act on ozone layer destruction, can be selected. For the above reasons, the light emitting element of the present invention is excellent in light emission luminance, light emission efficiency, and durability because of good film formation.

In the general formula (1), m and n each represent an integer of 1 or more, and k represents an integer of 0 or more. p and q are each a molar fraction (%) and represent 1 to 99 (%), and r is 0 to 98.
(%). p + q + r = 100 (%). m is preferably 1 to 3, n is preferably 1 to 3, and k is preferably 0 to 2, and more preferably m is 1 to 2,
n is 1-2 and k is 0. Preferably 20 to 9 as p
5, preferably 1 to 50 as q, and preferably 0 as r
And p is more preferably 50 to 95, and q is 5
５０50, r is 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. ),

A 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.
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).

The general formula (1) is preferably the following general formula (2).

[0029]

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In the general formula (2), A ′ represents carbazole, and may be bonded to the main chain at any of the 1- to 9-positions. B ′ is a partial structure containing a 1,3,4-oxadiazole skeleton, and C ′ represents a monomer unit having a structure other than A ′ and B ′. x, y, and z are each a mole fraction (%)
X and y represent 1 to 99 (%), and r is 0 to
98 (%), and p + q + r = 100 (%).
At least one of A ', B', and C 'is substituted with a ballast group having 4 or more carbon atoms.

In the general formula (2), A ′ represents carbazole and may be bonded to any of the 1- to 9-positions, but is preferably bonded to the 9-position (nitrogen atom of carbazole). B ′ is a partial structure containing a 1,3,4-oxadiazole skeleton, and is preferably

[0032]

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This is a partial structure represented by Z is preferably 0. The preferred range of the ballast group and the preferred range of the substituent other than the ballast group are the same as those in the general formula (1).

Specific examples of the preferred monomer unit and a specific example of the synthesis reaction are shown below together with the route. However, the present invention is not limited thereto.

[0035]

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[0036]

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[0037]

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(Specific Method for Synthesizing Monomer)

[0039]

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1) Synthesis of Monomer A-3 (Synthesis of Compound X-1) Carbazole was placed in a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser.
50.1 g (0.3 mol), 1-bromododecane 77 g (0.31 mol), toluene 250 ml, potassium hydroxide 18 g (0.31 mol), tetra-n-butylammonium bromide 5 g, and water 100 ml were charged. While stirring the contents with a magnetic stirrer, reflux
Allowed to react for hours. After completion of the reaction, the aqueous layer was removed, and the toluene layer was washed twice with 200 ml of water. The aqueous layer was removed, and the toluene layer was dried over anhydrous magnesium sulfate. After filtration, the filtrate was evaporated under reduced pressure to remove the solvent, whereby a solid was deposited. The crystals were recrystallized from ethanol to obtain 92 g of compound X-1 as crystals.

(Synthesis of Compound X-2) N, N-dimethylformamide (DMF) (150 ml) was charged into a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser, and stirred with a magnetic stirrer. Then, an ice-methanol bath was attached thereto, and the internal temperature was lowered to -10 ° C. here,
47 g (0.3 mol) of phosphorus oxychloride was gradually added dropwise so that the internal temperature did not exceed 0 ° C. After the end of the dropping, 15
Stirring was continued for about a minute. Then here the crystal 101 of compound X-1
A solution of g (0.3 mol) dissolved in 200 ml of DMF was gradually added dropwise over 10 minutes. After completion of the dropwise addition, the reaction was carried out with stirring for about 30 minutes at room temperature, a hot water bath was attached, the temperature was raised to 80 ° C., and the reaction was carried out for another 3 hours. After completion of the reaction, the reaction mixture was poured into 3 liters of cold water to precipitate crystals. The crystals were separated by filtration and recrystallized from a mixed solvent of ethanol and water to obtain 97 g of Compound X-2 as crystals.

(Synthesis of Monomer A-3) In a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser, 72.6 g (0.2 mol) of compound X-2, 2,2 as a polymerization inhibitor,
5 g of 6-di-t-butyl-4-methylphenol, 71.5 g (0.2 mol) of triphenylmethylphosphonium bromide, and 400 ml of N, N-dimethylformamide (DMF) were charged, and stirred with a magnetic stirrer. Attach an ice-methanol bath to
The internal temperature was reduced to 0 ° C. Here, 0.2 mol equivalent of a methanol solution of 28% by mass of sodium methoxide was added dropwise over 10 minutes. After the completion of the dropwise addition, the cooling bath was removed, the temperature was changed to room temperature, and stirring was continued for about 3 hours in this state. After completion of the reaction, the reaction mixture was poured into 3 liters of cold water to precipitate crystals. The crystals were separated by filtration and separated by silica gel column chromatography using an eluent having a volume mixing ratio of n-hexane / ethyl acetate = 4/1 to obtain monomer A-
66 g of 3 crystals were obtained.

2) Synthesis of Monomer B-2 (Synthesis of Compound Y-1) In a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser, 117 g (0.5 mol) of 4-octylbenzoic acid, 400 ml of ethyl acetate, D as catalyst
One drop of MF was charged and the internal temperature was maintained at 50 ° C. using a hot water bath while stirring the contents using a magnetic stirrer. When 127 g (1.0 mol) of oxalyl chloride was gradually added dropwise, the reaction occurred while generating a violent gas. After completion of the dropwise addition, the reaction was further continued at this temperature, and when the reaction was continued for about 2 hours, almost no gas generation was observed. The reflux condenser was removed, a device for distillation under reduced pressure via a trap was attached, and all volatile components were distilled off using an aspirator. Thus, 4-octylbenzoyl chloride was synthesized. Separately, in a 2000 ml three-necked flask equipped with a thermometer and a reflux condenser, 107.6 g (0.5 mol) of 4-bromobenzhydrazide, N, N-
800 ml of dimethylacetamide was 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, the entire amount of 4-octylbenzoyl chloride synthesized above 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 give compound Y-
201 g of 1 crystal was obtained.

(Synthesis of Compound Y-2) A 200 ml three-necked flask equipped with a thermometer and a reflux condenser was charged with 200 g of the compound Y-1 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 ethanol to obtain 159 g of compound Y-2 as crystals.

(Synthesis of Monomer B-2) In a 2000 ml three-necked flask equipped with a thermometer and a reflux condenser, 124 g (0.3 mol) of the compound Y-2 and 2,6 as a polymerization inhibitor were added.
-Di-t-butyl-4-methylphenol 7 g, triphenylphosphine 1 g, 10% by mass palladium-supported activated carbon catalyst 5 g,
74 g (0.5 mol) of 4-phenylboronic acid, 106 sodium carbonate
g (1.0 mol), diethylene glycol dimethyl ether 5
100 ml of water and 100 ml of water were charged and reacted under reflux conditions for 5 hours while stirring with 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. The crude crystals were recrystallized from a mixed solvent of ethyl acetate / ethanol to obtain crystals of monomer B-2.
7 g were obtained.

Further, specific examples of the polymer compound (polymer preferably used in the present invention) formed by the polymerization reaction of the above-mentioned 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.

[0047]

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[0048]

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[0049]

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(Specific Method for Synthesizing Polymer)

[0051]

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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, 15.5 g of N-vinylcarbazole (0.08 mol
l), monomer B-2 8.72 g (0.02 mol), toluene 150 ml
And passed through a stream of nitrogen. While stirring the contents using a magnetic stirrer, the internal temperature was controlled at 70 ° C. To this, azobisisobutyronitrile as an initiator was added in 0.1 g portions five times every hour. 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 put into 3 liters of methanol to precipitate and purify the polymer, and the precipitated polymer was separated by filtration.
Dried. In this way, 22.9 g of the polymer P-5 was obtained as a flaky 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 host material, a hole injecting material, a hole transporting material, a light emitting material, an electron transporting material, and an electron injecting material. It is preferably used as a material having both functions of a host material and a charge injection transport 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 element having one or more layers, preferably two or more layers, of a light-emitting element material 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.

The materials contained in the light emitting device of the present invention include light emitting device materials such as a hole injecting material, a hole transporting material, a hole blocking material, an electron injecting material, an electron transporting material, an electron blocking material and a light emitting material. Any material may be used as long as it is used as the material. 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.

The luminescent material used in the present invention is preferably at least one of an orthometalated metal complex and a porphyrin metal complex which are phosphorescent compounds.
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 ortho-metalated metal complex is not particularly limited, but when iridium is used, trivalent is preferred. 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 has at least one layer containing the polymer represented by the general formula (1). To provide the light emitting device of the present invention,
In the organic compound layer of the light emitting device,
The content is preferably 1 to 100% by mass, more preferably 1 to 100% 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, a non-alkali 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 to produce the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating evaporation method, a chemical reaction method (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 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 an electron beam method, a sputtering method, a resistance heating evaporation method, a coating method, or the like. The metal can be evaporated alone or two or more components can be evaporated at the same time. 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 the anode or the hole injection layer or the hole transport layer when applying an electric field and also injecting electrons from the cathode or the electron injection layer or the electron transport layer. 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, 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. 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 a function of injecting holes from the anode, a function of transporting holes, or 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 ink jet method, or a method of coating by dissolving or dispersing the hole injecting and transporting agent in a solvent (spin coating, 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, and a function of blocking holes injected from the anode. Good. Specific examples thereof include triazole derivatives, oxazole derivatives, oxadiazole derivatives,
Heterocyclic tetracarboxylic anhydrides such as fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, 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.

Examples of the method for forming the electron injection layer and the electron transport layer include a vacuum deposition method, an LB method, an ink-jet method, and a method in which the electron injection and transport agent is dissolved or dispersed in a solvent and coated (spin coating method, casting method, 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 and oxygen from entering the element. As a specific example,
In, Sn, Pb, Au, Cu, Ag, Al, Ti, N
metal such as i, MgO, SiO, SiO ₂ , Al ₂ O ₃ , G
eO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O 3, T
metal oxides such as iO ₂ , MgF ₂ , LiF, AlF ₃ , C
aF ₂ metal fluorides such as, polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, poly-dichloro-difluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, At least one with tetrafluoroethylene
A copolymer obtained by copolymerizing a monomer mixture containing a kind of comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0.1% The following moisture-proof substances are listed.

The method for forming the protective layer is not particularly limited. For example, a vacuum evaporation 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.

[0082]

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 brightness 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%.

The device 101 was the same as the device 101 except that the light emitting material of the light emitting layer and other materials were changed as shown 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.

[0085]

[Table 1]

[0086]

[Table 2]

[0087]

Embedded image

From the table, as compared with the light emitting devices 101 to 104 using coumarin-6 as a light emitting material, the devices 105 to 110 using the polymer of the present invention showed an initial light emission luminance and an initial luminance 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.

[0089]

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

Claims (5)

[Claims] 1. A polymer represented by the following general formula (1). Embedded image (Where A represents a monomer unit containing at least one selected from pyrrole, thiophene, furan, indole, carbazole, dibenzothiophene, benzofuran, and dibenzofuran. B represents imidazole, pyrazole, pyridazine, pyrimidine, Pyrazine,
Represents a monomer unit containing at least one selected from oxazole, thiazole, isoxazole, isothiazole, triazole, tetrazole, oxadiazole and thiadiazole. C represents a monomer unit having another structure. m and n represent an integer of 1 or more, and k represents an integer of 0 or more. p, q, and r are each a mole fraction (%), p and q represent 1 to 99 (%), and r represents 0 to 98 (%). p + q + r = 100 (%)
It is. In at least one monomer unit of A, B, and C, at least one selected from an alkyl group, an alkoxy group, an ester group, an amide group, and a sulfonamide group having 4 to 20 carbon atoms is substituted. I have. ) 2. In the formula (1), at least one of A is a monomer unit having a carbazole skeleton, and at least one of B is a monomer unit having a 1,3,4-oxadiazole skeleton. The polymer according to claim 1, wherein 3. The polymer according to claim 1, wherein each of A, B and C in the general formula (1) is a vinyl monomer unit. 4. A light-emitting device having a layer containing at least one polymer between an anode and a cathode, wherein at least one of the polymers is the polymer according to any one of claims 1 to 3. A light emitting element characterized by the above-mentioned. 5. The light-emitting device according to claim 4, wherein the layer containing the polymer contains at least one light-emitting material capable of emitting light from triplet excitons.