JP2007277306A - Material for organic luminescent element, method for producing the same and the organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for organic luminescent elements able to form thin membranes and suitably used as a light emission material for the organic electroluminescent elements, and the organic electroluminescent element excellent in light emission characteristics and durability. <P>SOLUTION: The material for the organic electroluminescent elements having electron transporting properties and positive hole transporting property by copolymerizing conjugated carbazole with imidazole structure-containing unit and excellent in solubility to solvents and able to easily form the thin membranes is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic electroluminescent element polymer useful as an organic electroluminescent element material, a method for producing the same, a material composition for an organic electroluminescent element, and an organic electroluminescent element.

An organic electroluminescence element (hereinafter also referred to as “organic EL element”) can be driven by a DC voltage, is a self-luminous element, has a wide viewing angle and high visibility, and a response speed. Therefore, it is expected to be a next-generation display element, and its research is actively conducted today.
As such an organic EL element, one having a single layer structure in which a light emitting layer made of an organic material is formed between an anode and a cathode, one having a hole transport layer between the anode and the light emitting layer, A multilayer structure such as a structure having an electron transport layer between a cathode and a light emitting layer is known, and all of these organic EL elements were injected from the cathode and the anode. The holes emit light by recombination in the light emitting layer.

  In an organic EL element, as a method of forming a functional organic material layer such as a light emitting layer or a charge transport layer that transports charges such as electrons or holes, a dry method in which an organic material is vacuum-deposited, and an organic material solution are used. A wet method of applying and drying is known. Among these, the dry method has a complicated process and is difficult to be applied to mass production, and has a limit in forming a layer having a large area. On the other hand, the wet method has a comparatively simple process and can be applied to mass production, and has an advantage that a functional organic material layer having a large area can be easily formed by, for example, an inkjet method. Therefore, it is industrially advantageous compared to the dry method.

On the other hand, a light emitting layer of an organic EL element is required to have high light emission efficiency. Recently, in order to realize high light emission efficiency, energy such as a triplet state molecule in an excited state is applied to the organic EL element. Attempts have been made to use it for light emission.
Specifically, in the case of an organic EL element having such a configuration, it has been reported that the external quantum efficiency of the organic EL element exceeds 8%, which was conventionally considered a limit value, and can be 8%. (For example, see Non-Patent Document 1).

  However, in conventional organic EL devices that use energy such as molecules in a triplet state, the light emitting layer is made of a low molecular material and is formed by a dry method such as a vapor deposition method. There is a problem of poor productivity.

  In order to solve this problem, for example, a light emitting layer made of a composition made of an iridium complex compound and polyvinyl carbazole is formed by a wet method as an organic EL element made of a polymer material using energy such as triplet state molecules. Have been proposed (see, for example, Non-Patent Document 1).

  However, this organic EL device has a drawback of a short service life (durability).

“Applied Physics Letters”, 1999, vol. 75, p. 4 Japanese Patent Laid-Open No. 2001-257076

The present invention has been made on the basis of the above circumstances, and the object thereof is an organic electroluminescence element that can easily form a thin film and is suitably used as a light-emitting material for an organic electroluminescence element. It is to provide materials for use.
Another object of the present invention is to provide an organic electroluminescence device having excellent light emission characteristics and durability.

The material for an organic electroluminescence device of the present invention is characterized by containing a structure represented by the following general formula (Ia) and a structure represented by the following general formula (Ib) as repeating units.

[In the above general formula (Ia), T ² is a hydrogen atom, a halogen atom, a monovalent organic group, and T ^{3 to} T ⁶ are a hydrogen atom, a halogen atom, or a monovalent organic that may form a ring. Indicates a group. T ¹ is a direct or divalent organic group, Ar ¹ is an aromatic ring group that may or may not have a substituent, a condensed ring group that may or may not have a substituent, and a substituent. And an organic group having a trivalent conjugated structure selected from these conjugates and a heterocyclic group which may or may not be present. ]

[In the general formula (Ib), R ¹ represents a monovalent organic group, and the general formula (Ib) does not include the structure of the general formula (Ia). ]

In the method for producing a material for an organic electroluminescence element of the present invention, the following (A) and (B) are essential components, and the following (C) and / or (D) is added as necessary to add palladium (Pd). A step of polycondensation reaction in the presence of the catalyst.
(A) At least one of the compounds represented by the following general formulas (IV-a) and (Va).
(B) At least one of the compounds represented by the following general formulas (IV-b) and (Vb).
(C) At least one of the compounds represented by the following general formulas (IV-c) and (Vc).
(D) At least one of the compounds represented by the following general formulas (IV-d) and (Vd).

V ⁵ -Ar ² -V ⁶ formula (IV-c)
V ⁷ -Ar ³ -V ⁸ general formula (IV-d)

[In the general formula (IV-a), Ar ¹ and T ^{1 to} T ⁶ are the same as those in the general formula (Ia). In the general formula (IV-b), R ¹ is In the general formula (IV-c), Ar ² is the same as that in the general formula (Ic), and in the general formula (IV-d). , Ar ³ is the same as that in the general formula (Id). In the general formulas (IV-a) to (IV-d), V ^{1 to} V ⁸ each independently represent a chlorine atom, a bromine atom, an iodine atom or a trifluoromethanesulfonyloxy group, and may be the same or different. Good. ]

Y ⁵ -Ar ² -Y ⁶ formula (V-c)
Y ⁷ -Ar ³ -Y ⁸ general formula (Vd)

[In the general formula (Va), Ar ¹ and T ^{1 to} T ⁶ are the same as those in the general formula (Ia). In the general formula (Vb), R ¹ is In the general formula (Vc), Ar ² is the same as that in the general formula (Ic), and in the general formula (Vd). , Ar ³ is the same as that in the general formula (Id). In the general formulas (Vb) to (Vd), Y ^{1 to} Y ⁸ each independently represent a monovalent group derived from boric acid, and may be the same or different. ]

The organic electroluminescent element of the present invention is characterized by having a light emitting layer formed of the material for organic electroluminescent elements.

The organic electroluminescence device material of the present invention has a conjugated structure as a whole, so that it has good electron transportability and hole transportability, and easily forms a thin film with excellent solubility in solvents. Therefore, it is extremely useful as a light emitting material for an organic electroluminescence element. In addition, since the polymer chain has an imidazole structure, it has excellent electron transport properties and excellent morphological stability at the initial stage of film formation. Furthermore, the energy level is suitably adjusted by using carbazole in the main chain. For this reason, by using the organic electroluminescent element material of the present invention, it is possible to obtain an organic electroluminescent element having excellent luminous efficiency and a long service life (durability).

Hereinafter, embodiments of the present invention will be described in detail.
<Material for organic electroluminescence element>
The organic EL device material of the present invention is a polymer in which at least one of an aromatic ring, a condensed ring and a heterocyclic ring is directly connected to a carbazole ring and has a conjugated structure main chain containing an imidazole group (hereinafter referred to as an imidazole-containing polymer). And is useful as a light emitting material for an organic electroluminescence device.

  Here, the “conjugated structure” means a state in which two or more multiple bonds are linked via only one single bond and interact with each other.

  The imidazole-containing polymer of the present invention contains a carbazole ring in the main chain, so that the energy level range is useful for an organic EL device that emits phosphorescence, and particularly as a light-emitting material for an organic EL device that emits green light. Useful.

The imidazole-containing polymer of the present invention has a polystyrene-reduced weight average molecular weight (hereinafter referred to as “Mw”) measured by gel permeation chromatography (GPC) of 1,000 to 10,000,000, preferably 2,000 to 1,000,000.
When the Mw of the imidazole-containing polymer is less than 1,000, the polymer composition described below may not be uniformly applied, while the Mw of the imidazole-containing polymer is 10,000,000. When it exceeds 000, there is a possibility of becoming insoluble in a solvent.

  As the organic electroluminescent device material of the present invention, a material containing a structure represented by the general formula (Ia) and a structure represented by the general formula (Ib) as a repeating unit is preferably used.

The material for an organic electroluminescence device of the present invention is characterized by containing a structure represented by the following general formula (Ia) and a structure represented by the following general formula (Ib) as repeating units.

[In the above general formula (Ia), T ² is a hydrogen atom, a halogen atom, a monovalent organic group, and T ^{3 to} T ⁶ are a hydrogen atom, a halogen atom, or a monovalent organic that may form a ring. Indicates a group. T ¹ is a direct or divalent organic group, Ar ¹ is an aromatic ring group that may or may not have a substituent, a condensed ring group that may or may not have a substituent, and a substituent. And an organic group having a trivalent conjugated structure selected from these conjugates and a heterocyclic group which may or may not be present. ]

[In the general formula (Ib), R ¹ represents a monovalent organic group, and the general formula (Ib) does not include the structure of the general formula (Ia). ]

In the general formula (Ia), examples of Ar ¹ include structures of formulas (1a-1) to (1a-5), and formulas (1a-1) and (1a-5) are preferable.

（＊はポリマーに結合する部位を表す）

(* Represents the site that binds to the polymer)

In the general formula (Ia), examples of the monovalent organic group representing the group T ² include an optionally substituted alkyl group having 1 to 30 carbon atoms and an optionally substituted alkyl group having 6 to 30 carbon atoms. An aryl group can be mentioned.

Specific examples of the optionally substituted alkyl group having 1 to 30 carbon atoms for T ² include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t -Butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n -Tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, trifluoromethyl group, pentafluoroethyl group, hepta Examples thereof include a fluoro-n-propyl group and a nonafluoro-n-butyl group.

  Specific examples of the optionally substituted aryl group having 6 to 30 carbon atoms include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 4- (n-hexyl) phenyl group, 4- (n-heptyl) phenyl group, 4- (n-octyl) phenyl group, 4- (n-nonyl) phenyl group, 4- (n-decyl) phenyl group, 4- (n-undecyl) phenyl group, 4- (n-dodecyl) phenyl group, 4- (n-tetradecyl) phenyl group, 4- (n-hexadecyl) phenyl group, 4- (n-octadecyl) phenyl group, 4- (n-eicosyl) phenyl group, 1-naphthyl group, 4-biphenyl group, o-methoxyphenyl group, m-methoxyphenyl group, p-methoxyphenyl group, p-ethoxyphenyl group, 4- (n-hexyloxy) phenyl group, 4- (n-he (Tyroxy) phenyl group, 4- (n-octaloxy) phenyl group, 4- (n-nonyloxy) phenyl group, 4- (n-decyloxy) phenyl group, 4- (n-undecyloxy) phenyl group, 4- (n- Dodecyloxy) phenyl group, 4- (n-tetradecyloxy) phenyl group, 4- (n-hexadecyloxy) phenyl group, 4- (n-octadecyloxy) phenyl group, 4- (n-eicosyloxy) phenyl Group, o-fluorophenyl group, m-fluorophenyl group, p-fluorophenyl group, o-trifluoromethylphenyl group, m-trifluoromethylphenyl group, p-trifluoromethylphenyl group, perfluorophenyl group, formula (I '), etc. can be mentioned.

Among these, preferred as T ² are an alkyl group having 1 to 12 carbon atoms, a phenyl group, an o-tolyl group, an m-tolyl group, and a p-tolyl group. Particularly preferred is a phenyl group.

Examples of the groups T ^{3 to} T ⁶ include a hydrogen atom, a halogen atom, and a monovalent organic group that may form a ring. The monovalent organic group may include the same as the T ^2. Preferably they are a hydrogen atom, a fluorine atom, a methyl group, and a phenyl group.

In the general formula (Ia), examples of T ¹ include the following general formula (II).

[In the above general formula (II), D and E may be the same or different and are selected from -O-, -COO-, -OCO-, -NHCO-, -CONH-, -S-, and direct coupling. T ⁷ and T ⁸ may be the same or different and are each independently selected from a direct bond or an alkylene group having 1 to 20 carbon atoms or an arylene group having 6 to 30 carbon atoms. * Indicates a site binding to the imidazole group, and ● indicates a site binding to Ar ¹ . ]

T ¹ is preferably a direct bond, an alkylene group having 1 to 20 carbon atoms, and an arylene group having 6 to 30 carbon atoms. More preferable examples include direct coupling and arylenes of the formulas (1a-6) to (1a-10).

（＊はイミダゾール基に結合）

(* Is bonded to imidazole group)

Specific examples of the general formula (Ia) include (A-1) to (A-5).

（＊はポリマーに結合部位を表す）

(* Represents the binding site on the polymer)

In the general formula (Ib), examples of the monovalent organic group representing the group R ¹ include an optionally substituted alkyl group having 1 to 30 carbon atoms and an optionally substituted alkyl group having 6 to 30 carbon atoms. An aryl group can be mentioned.

Specific examples of the optionally substituted alkyl group having 1 to 30 carbon atoms and the optionally substituted aryl group having 6 to 30 carbon atoms of R ¹ include those similar to T ² .

In general formula (Ib), it is preferably polymerized at the 3, 6 or 2, 7 position relative to the N atom of carbazole. More preferably, it is polymerized at the 3,6 positions.

As the material for an organic electroluminescence element of the present invention, a material further containing a structure represented by the following general formula (Ic) as a repeating unit in the above-described configuration can be suitably used.

-Ar ² - formula (I-c)
[In the above general formula (Ic), Ar ² contains an Ir atom and may or may not have a substituent, an aromatic ring group, or a condensed group that may or may not have a substituent. An organic group having a divalent conjugated structure selected from a cyclic group, a heterocyclic group which may or may not have a substituent, and a conjugate thereof, wherein the general formulas (Ia) and ( Those not corresponding to Ib) are shown. ]

In the general formula (Ic), Ar ² can be represented by, for example, the general formula (1c-1).

[In the general formula (1c-1), Ar ^{2 ′} is selected from a trivalent aromatic ring group or a heterocyclic group, Q ¹ is a divalent organic group or a direct bond, and L ¹ is coordinated to an Ir atom. A monovalent ligand that can be formed, L ² represents a ligand that can coordinate to an Ir atom. ]

In the general formula (1c-1), examples of Ar ^{2 ′} include the following structures.

（＊はポリマーに結合部位を表す）

(* Represents the binding site on the polymer)

In the general formula (1c-1), examples of Q ¹ include the following general formula (1c-2).

[In general formula (1c-2), X and Z may be the same or different from each other, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -S-, and direct connection. Can do. Q ² , Q ^{2 ′} , and Q ³ may be the same or different and are each independently selected from a direct bond or an alkylene group having 1 to 20 carbon atoms or an arylene group having 6 to 20 carbon atoms. ]

In the general formula (1c-1), examples of L ¹ include acetylacetone derivatives and phenylpyridine derivatives such as the general formulas (1c-3) to (1c-5).

[In General Formula (1c-3), Q ⁴ represents an alkyl group having 1 to 20 carbon atoms. ]

[In General Formula (1c-4), Q ⁵ and Q ⁶ are selected from a fluorine atom, a trifluoromethyl group, and an alkyl group having 1 to 20 carbon atoms, which may be the same as or different from each other, and form a ring. May be. x and y are each independently an integer of 0 to 4. ]

[In General Formula (1c-5), Q ⁷ and Q ⁸ are selected from a fluorine atom, a trifluoromethyl group, and an alkyl group having 1 to 20 carbon atoms, which may be the same as or different from each other to form a ring. It may be. x is an integer of 0 to 3, and y is an integer of 0 to 5. ]

In General Formula (Ic), Ar ² can also be represented by General Formula (1c-6), for example.

[In General Formula (1c-6), L ³ and L ⁴ may be the same or different and may be a monovalent ligand capable of coordinating to Ir, and L ² may be coordinated to an Ir atom. Represents a quantifier. ]

In the general formula (1c-6), examples of L ³ and L ⁴ include phenylpyridine derivatives such as the general formula (1c-4) and the general formula (1c-5).

In general formula (1c-1) and general formula (1c-6), examples of L ² include acetylacetone derivatives and phenylpyridine derivatives such as general formula (1c-7) and general formula (1c-8). Can do.

[In General Formula (1c-7), Q ⁹ and Q ¹⁰ are selected from a fluorine atom, a trifluoromethyl group, and an alkyl group having 1 to 20 carbon atoms, which may be the same as or different from each other, and form a ring. May be. x is an integer of 0 to 5, and y is an integer of 0 to 4. ]

[In General Formula (1c-8), Q ¹¹ and Q ¹² may be the same or different and are selected from a hydrogen atom, a fluorine atom, a trifluoromethyl group, and an alkyl group having 1 to 20 carbon atoms. ]

Specific examples of Ar ² are given in (C-1) to (C-11).

（＊はポリマーに結合部位を表す）

(* Represents the binding site on the polymer)

(C-3) is described in J. Org. Am. Chem. Soc. 126, 7041 (2004). (C-4) is described in Chem. Eur. J. et al. 11, volume 5007 (2005). Q ⁹ and Q ¹⁰ in (C-9) are the same as those in General Formula (1c-7).

  As the material for an organic electroluminescence element of the present invention, a material further containing a structure represented by the following general formula (Id) as a repeating unit in the above configuration can also be suitably used.

—Ar ³ — general formula (Id)
[In the above general formula (Id), Ar ³ may have a substituent, an aromatic ring group which may or may not have a substituent, a condensed ring group which may or may not have a substituent, a substituent An organic group having a divalent conjugated structure selected from the above-mentioned heterocyclic groups, which may or may not have, and the above general formulas (Ia), (Ib), And those not corresponding to (Ic). ]

Examples of the organic group having a divalent conjugated structure that represents Ar ³ in the general formula (Id) include those represented by the following formulas (a) to (o).

[Wherein R ^{2 to} R ⁴ , R ⁶ and R ⁷ are each independently a hydrogen atom, a fluorine atom, a cyano group, a trifluoromethyl group, an optionally substituted alkyl group having 1 to 30 carbon atoms, or a substituent. Represents an optionally substituted aryl group having 6 to 30 carbon atoms, and R ⁵ represents a monovalent organic group. ]

Among these, as the organic group having a divalent conjugated structure representing the group Ar ³ , those represented by the formulas (a) and (e) and R ² having a hydrogen atom are preferable.

The ratio of the number of repetitions in general formula (Ia), the number of repetitions in general formula (Ib), the number of repetitions in general formula (Ic), and the number of repetitions in general formula (Id) is k: l. : M: n, where k + 1 + m + n is 100,
0 <k <100, 0 <l <100, 0 ≦ m ≦ 20, 0 ≦ n ≦ 50
Is preferably within the range of
5 ≦ k ≦ 90, 30 ≦ l ≦ 95, 0 ≦ m ≦ 20, 0 ≦ n ≦ 50
More preferably within the range of
20 ≦ k ≦ 70, 30 ≦ l ≦ 70, 1 ≦ m ≦ 10, 0 ≦ n ≦ 50,
It is especially preferable that it exists in the range.
Outside this range, there is a problem that sufficient light emission efficiency and durability of the organic electroluminescence element cannot be obtained.

  The imidazole-containing polymer of the present invention can be obtained by the following methods (1) to (4). This method is generally referred to as “SUZUKI coupling”.

(1) A method in which the following (a) and (b) are subjected to a polycondensation reaction, preferably in a solvent, in the presence of a catalyst containing palladium (Pd) (hereinafter referred to as “Pd-based catalyst”).
(2) A method in which the following (a), (b) and (c) are subjected to a polycondensation reaction, preferably in a solvent, in the presence of a catalyst containing palladium (Pd) (hereinafter referred to as “Pd-based catalyst”).
(3) A method in which the following (a), (b) and (d) are subjected to a polycondensation reaction, preferably in a solvent, in the presence of a catalyst containing palladium (Pd) (hereinafter referred to as “Pd-based catalyst”).
(4) The following (a), (b), (c) and (d) are polycondensed in the presence of a catalyst containing palladium (Pd) (hereinafter referred to as “Pd-based catalyst”), preferably in a solvent. How to react.

(A) At least one of the compounds represented by the general formulas (IV-a) and (Va).
(B) At least one of the compounds represented by the general formulas (IV-b) and (Vb).
(C) At least one of the compounds represented by the above general formulas (IV-c) and (Vc).
(D) At least one of the compounds represented by the general formulas (IV-d) and (Vd).

In the compounds represented by the general formulas (IV-a) to (IV-d) (hereinafter referred to as “raw dihalogen compound”), V ^{1 to} V ⁸ are each independently a chlorine atom, bromine atom, iodine atom or A trifluoromethanesulfonyloxy group is shown, and a bromine atom and an iodine atom are particularly preferable. In addition, the group V ³ and the group V ⁴ in the general formula (IV-b) are preferably bonded to the 2nd or 3rd position and the 6th or 7th position of the carbazole ring, respectively.
The above raw material dihalogen compounds can be used alone or in combination of two or more.

In the compounds represented by the general formulas (Va) to (Vd) (hereinafter referred to as “raw material boronic acid compounds”), Y ^{1 to} Y ⁸ are each independently monovalent derived from boric acid. Preferred examples include groups represented by the following formulas (ii) to (vi). In addition, Y ³ and Y ⁴ in the general formula (Vb) are preferably bonded to the 2nd or 3rd position and the 6th or 7th position of the carbazole ring, respectively.
The raw material boronic acid compounds as described above can be used alone or in combination of two or more.

  Examples of the raw material boronic acid compound having the groups represented by the above formulas (ii) to (vi) include bis halides or bis (trifluoromethanesulfonate) compounds as raw materials. Org. Chem. 1995, 60, p. It can be synthesized by the method described in 7508.

  In the above method, the ratio of the raw material dihalogen compound and the raw material boronic acid compound used for the polycondensation reaction for obtaining the imidazole-containing polymer is 0.9 to 1.1 equivalents of the raw material boronic acid compound to the raw material dihalogen compound. It is preferable that

Examples of the Pd-based catalyst used in the polycondensation reaction include tetrakis (triphenylphosphine) palladium (0), bis (triphenylphosphine) palladium (II) dichloride, [1,1-bis (diphenylphosphino) ferrocene. ] Palladium (II) dichloride-dichloromethane complex compound (1: 1), bis (triphenylphosphine) palladium (II) diacetate, benzylbis (triphenylphosphine) palladium (II) chloride, [1,2-bis (diphenylphosphine) [Fino) ethane] palladium (II) dichloride, [1,3-bis (diphenylphosphino) propane] palladium (II) dichloride, [1,4-bis (diphenylphosphino) butane] palladium (II) dichloride, bis ( Tri-o-tolylphosphine) para Um (II) dichloride, bis (tricyclohexylphosphine) palladium (II) dichloride, bis (methyldiphenylphosphine) palladium (II) dichloride, bis (benzonitrile) palladium (II) dichloride, bis (acetonitrile) palladium (II) dichloride Bis (dibenzylideneacetone) palladium (0), bis (2,4-pentanedionate) palladium (II), palladium (II) acetate, dichloro (1,5-cyclooctadiene) palladium (II), allyl Palladium (II) chloride dimer, [Ni-propylacrylamide / 4- (diphenylphosphino) styrene copolymer] palladium (II) dichloride and the like can be mentioned.
Of these Pd-based catalysts, tetrakis (triphenylphosphine) palladium (0) is particularly preferable.
These Pd-based catalysts can be used alone or in admixture of two or more.
The usage-amount of a Pd type catalyst is 0.1-20 mass parts normally with respect to a total of 100 mass parts of a raw material compound, Preferably it is 0.5-10 mass parts.

In the polycondensation reaction, a phosphine ligand can be added as necessary.
Examples of the phosphine ligand include tri-n-butylphosphine, tri-t-butylphosphine, tricyclohexylphosphine, dicyclohexylphenylphosphine, cyclohexyldiphenylphosphine, ethyldiphenylphosphine, phenyldiethylphosphine, methyldiphenylphosphine, and n-propyl. Diphenylphosphine, methoxydiphenylphosphine, ethoxydiphenylphosphine, triphenylphosphine, tri (2-methylphenyl) phosphine, tri (3-methylphenyl) phosphine, tri (4-methylphenyl) phosphine, tri (4-methoxyphenyl) phosphine , Tri (2,6-dimethoxyphenyl) phosphine, sodium diphenylphosphinobenzene-3-sulfonate, 4- (dimethylamino) B) phenyldiphenylphosphine, 2-pyridyldiphenylphosphine, tri (2-furyl) phosphine, tri (2-thienyl) phosphine, bis (diphenylphosphino) methane, 1,2-bis (dimethylphosphino) ethane, 1, 2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1,4-bis (diphenylphosphino) butane, 1,1-bis (diphenylphosphino) ferrocene, Examples include compounds represented by 6-1) to formula (6-9).
Of these phosphine ligands, triphenylphosphine is particularly preferable.
The above phosphine ligands can be used alone or in admixture of two or more.
The usage-amount of a phosphine ligand is 0-50 mass parts normally with respect to a total of 100 mass parts of a raw material compound, Preferably it is 0-20 mass parts.

In the polycondensation reaction, an alkali metal compound can be added as necessary. Examples of the alkali metal compound include methoxy sodium, ethoxy sodium, n-propoxy sodium, i-propoxy sodium, n-butoxy sodium, sec-butoxy sodium, t-butoxy sodium, sodium fluoride, sodium carbonate, sodium hydrogen carbonate, Methoxy potassium, ethoxy potassium, n-propoxy potassium, i-propoxy potassium, n-butoxy potassium, sec-butoxy potassium, t-butoxy potassium, potassium fluoride, potassium carbonate, potassium hydrogen carbonate, methoxy rubidium, ethoxy rubidium, n- Propoxy rubidium, i-propoxy rubidium, n-butoxy rubidium, sec-butoxy rubidium, t-butoxy rubidium, rubidium fluoride, rubidium carbonate, carbonic acid Rubidium, methoxycesium, ethoxycesium, n-propoxycesium, i-propoxycesium, n-butoxycesium, sec-butoxycesium, t-butoxycesium, cesium fluoride, cesium carbonate, cesium hydrogencarbonate, methoxyfrancium, ethoxyfrancium N-propoxy francium, i-propoxy francium, n-butoxy francium, sec-butoxy francium, t-butoxy francium, francium fluoride, francium carbonate, francium hydrogen carbonate and the like.
Of these alkali metal compounds, t-butoxy sodium, sodium carbonate, sodium hydrogen carbonate, t-butoxy potassium, potassium fluoride, potassium carbonate, potassium hydrogen carbonate, cesium fluoride and the like are preferable.
The above alkali metal compounds can be used alone or in admixture of two or more.
The usage-amount of an alkali metal compound is 10-5000 mass parts normally with respect to a total of 100 mass parts of a raw material compound, Preferably it is 100-1000 mass parts.
In addition to alkali metal compounds, quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide can also be used.
The above bases such as alkali metals and ammonium salts can be used by dissolving in water.

Examples of the solvent used in the polycondensation reaction include aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; ethers such as tetrahydrofuran, dioxane, diethyl ether, dimethoxyethane, diethoxyethane, anisole, and diphenyl ether; Esters such as ethyl acetate, n-propyl acetate, and n-butyl acetate; ketones such as cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone; N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone And amides.
Of these solvents, toluene, tetrahydrofuran and the like are preferable.
These solvents can be used alone or in admixture of two or more, and can also coexist with water.
The usage-amount of a solvent is 100-100,000 mass parts normally with respect to a total of 100 mass parts of a raw material compound, Preferably it is 400-10,000 mass parts.
A surfactant such as Aliquat 336 may also be added. The usage-amount of surfactant is 0-100 mass parts with respect to 100 mass parts of raw material compounds, Preferably it is 0-20 mass parts.

Further, in the polycondensation reaction, an end-capping agent can be used to seal the end of the obtained imidazole-containing polymer.
The end-capping agent may be charged together with the raw material compound during the polycondensation reaction, or may be added to the reaction system after the polycondensation reaction is completed. In the former case, a Pd-based catalyst, a phosphine ligand or an alkali metal compound can be added together.

  Specific examples of the end capping agent include phenylboric acid, (methyl) (phenyl) boric acid, (methoxy) (phenyl) boric acid, bromobenzene, and the like.

In the polycondensation reaction, the reaction temperature is usually 0 to 250 ° C., preferably 10 to 200 ° C., and the reaction time is usually 1 to 200 hours, preferably 3 to 80 hours.
Such a polycondensation reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon.

  In addition, as described in “Macromolecular” Vol. 35, p. 1988 (2002), general formulas (IV-a) to (IV-d) are used as monomers, and 1 equivalent or more of bis Even if (1,5-cyclooctadiene) nickel (0) is used, an imidazole-containing polymer can be obtained.

Since the imidazole-containing polymer as described above has excellent solubility in a solvent, a coating solution for forming a thin film can be easily prepared. Therefore, a thin film is easily formed with the coating solution. In addition, it has good charge transportability. Therefore, the imidazole-containing polymer can be used very suitably as a light-emitting material for an organic EL device, alone or in combination with other light-emitting materials having phosphorescence, for example.

The imidazole-containing polymer of the present invention may include a bond that causes the conjugated structure of the main chain to be cleaved as long as the characteristics as an organic EL element are not impaired.
Specifically, the organic group having a divalent conjugated structure representing the group Ar ³ in the general formula (1-d) is, for example, an organic group having a conjugated cleavage structure represented by the following formulas (q) to (u): Can be partially replaced.
In the case of replacing the conjugate cleavage structure with an organic group, the content ratio of the organic group of the conjugate cleavage structure may be 20% or less of the total of the organic group representing the group Ar ³ and the organic group of the conjugate cleavage structure. preferable. When the content ratio of the organic group of this conjugate cleavage structure exceeds 20%, a sufficient conjugate structure cannot be obtained, and problems such as insufficient emission characteristics and durability may occur.

  In the material composition for an organic electroluminescence device of the present invention, the imidazole-containing polymer can be used alone or in admixture of two or more.

  The imidazole-containing polymer of the present invention can be used by adding a triplet light-emitting metal complex compound (hereinafter referred to as “complex compound”).

  Examples of complex compounds include iridium complex compounds, platinum complex compounds, palladium complex compounds, rubidium complex compounds, osmium complex compounds, rhenium complex compounds, and among these, iridium complex compounds are particularly preferable.

Examples of the iridium complex compound include iridium, 2-phenylpyridine, 3-phenylpyridine, 2-phenylpyrimidine, 4-phenylpyrimidine, 5-phenylpyrimidine, bipyridyl, 1-phenylpyrazole, 2-phenylquinoline, 2- Phenylbenzothiazole, 2-phenyl-2-oxazoline, 2,4-diphenyl-1,3,4-oxadiazole, 5-phenyl-2- (4-pyridyl) -1,3,4-oxadiazole, And a complex compound with a nitrogen atom-containing aromatic compound such as a derivative thereof.
Specific examples of such iridium complex compounds include compounds represented by the following formulas (7) to (12).

In the above formulas (7) to (12), R ⁸ represents a substituent composed of a fluorine atom, a trifluoromethyl group, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and is the same It may be different or different. Independently, x is an integer of 0 to 4, and y is an integer of 0 to 3.

In the above, specific examples of the alkyl group having 1 to 20 carbon atoms according to the substituent R ⁸ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t -A butyl group, n-hexyl group, n-octyl group, etc. can be mentioned.
Specific examples of the aryl group having 6 to 20 carbon atoms related to the substituent R ⁸ include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-xylyl group, 2,4 -Xylyl group, 2,5-xylyl group, 2,6-xylyl group, 3,4-xylyl group, 3,5-xylyl group, 4-biphenyl group, 1-naphthyl group and the like can be mentioned.

  In the organic EL device material composition of the present invention, the content ratio of the complex component is preferably 0 to 30 parts by weight, more preferably 0 to 30 parts by weight with respect to 100 parts by weight of the polymer component composed of the imidazole-containing polymer. 10 parts by weight. When the content ratio of the complex component is excessive, there is a possibility that a phenomenon of concentration quenching in which the light emission luminance decreases instead.

  The organic EL element material composition of the present invention can be blended with an appropriate additive such as a charge transporting compound, if necessary.

  Specific examples of the charge transporting compound are represented by the following formulas (13-1) to (13-10), and the following formulas (14-1) to (14-20). Examples thereof include electron transporting compounds and hole transporting compounds represented by the following formulas (15-1) to (15-34).

Here, in the above formula (14-16), R ⁹ independently represents any of the groups represented by the following formulas (vii) to (ix).

  Here, in the above formula (15-12), n represents an integer of 1 or more.

  The content of the charge transporting compound in the material composition for an organic EL device of the present invention is 0 to 200 parts by weight, preferably 0 to 100 parts by weight, based on 100 parts by weight of the imidazole-containing polymer. .

  The material composition for an organic EL device of the present invention is usually prepared as a composition solution by dissolving the imidazole-containing polymer and a complex compound added as necessary in an appropriate organic solvent.

  Here, the organic solvent for preparing the composition solution is not particularly limited as long as it can dissolve the polymer component and the complex component to be used, and specific examples thereof include toluene, xylene, mesitylene and the like. Aromatic hydrocarbons; Halogenated hydrocarbons such as chloroform, dichloroethane, tetrachloroethane, chlorobenzene, o-dichlorobenzene; N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone, etc. Examples include amides, 2-heptanone, cyclohexanone, propylene glycol methyl ether acetate, ethyl lactate, ethyl 3-ethoxypropionate, and anisole. These organic solvents can be used alone or in combination of two or more. Among these, it is preferable to use an organic solvent having an appropriate evaporation rate, specifically, an organic solvent having a boiling point of about 70 to 200 ° C. in that a thin film having a uniform thickness can be easily obtained.

  The amount of the organic solvent used varies depending on the type and the type of the imidazole-containing polymer and the complex compound, but the total concentration of the imidazole-containing polymer and the complex compound is usually 0.1 to 20% by weight, preferably The amount is 0.5 to 10% by weight.

  Since the organic EL element material composition as described above contains the above-mentioned organic EL element material, it is possible to form a light emitting layer for an organic EL element having excellent light emission characteristics and durability.

<Organic EL device>
The organic EL element of this invention has a light emitting layer formed from said organic EL element material composition.
This light emitting layer can be formed by applying the above-described composition solution to the surface of an appropriate substrate and then removing the organic solvent.
As a method for applying the composition solution, for example, an appropriate method such as a spin coating method, a dipping method, a roll coating method, an ink jet method, or a printing method can be employed.
Although the thickness of the light emitting layer formed is not specifically limited, Usually, 10-200 nm, Preferably it selects in the range of 30-100 nm.
According to the material composition for an organic EL device of the present invention, a light emitting layer having sufficiently high light emission luminance can be easily formed by a wet method such as an ink jet method.

FIG. 1 is an explanatory cross-sectional view showing an example of the configuration of the organic EL element of the present invention.
In the organic EL element of this example, an anode 2 as an electrode for supplying holes is provided on a transparent substrate 1 by, for example, a transparent conductive film, and a hole injecting and transporting layer 3 is provided on the anode 2. A light emitting layer 4 is provided on the hole injecting and transporting layer 3, and an electron injecting layer 5 is provided on the light emitting layer 4 through a hole blocking layer 8 as necessary, and electrons are supplied onto the electron injecting layer 5. A cathode 6 as an electrode is provided, and the anode 2 and the cathode 6 are electrically connected to a DC power source 7.

In this organic EL element, as the transparent substrate 1, a soda glass substrate, a transparent resin substrate, a quartz glass substrate, or the like can be used.
The material constituting the anode 2 is preferably a transparent material having a large work function, for example, 4 eV or more. Examples thereof include an ITO (indium-tin oxide) film, a tin oxide (IV) film, and an oxide film. Examples thereof include a copper (II) film and a zinc oxide film. Here, the work function refers to the minimum work required to extract electrons from a solid in a vacuum.
The thickness of the anode 2 varies depending on the type of material, but is usually selected in the range of 10 to 1,000 nm, preferably 50 to 200 nm.

The hole injection transport layer 3 is provided to efficiently supply holes to the light emitting layer 4 and has a function of receiving holes from the anode 2 and transporting them to the light emitting layer 4. Is.
As a constituent material of the hole injection / transport layer 3, a charge injection / transport material such as poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate is preferably used.
The thickness of the hole injecting and transporting layer 3 is not particularly limited, but is usually selected in the range of 10 to 200 nm.

  The light emitting layer 4 has a function of combining electrons and holes and emitting the binding energy as light, and the light emitting layer 4 is formed of the above-described composition for organic EL elements. Although the thickness of the light emitting layer 4 is not specifically limited, Usually, it selects in the range of 5-200 nm.

  The hole block layer 8 is not necessarily essential, but is preferably provided. The hole blocking layer 8 suppresses the penetration of holes supplied to the light emitting layer 4 through the hole injecting and transporting layer 3 into the electron injecting and transporting layer 5, and the combination of electrons and holes in the light emitting layer 4. It has a function of promoting the light emission and further improving the light emission efficiency.

  The constituent material of the hole blocking layer 8 is preferably 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (basocproin: BCP) represented by the following formula (16), 1,3,5-tri (phenyl-2-benzimidazolyl) benzene (TPBI) represented by 17) can be used. The thickness of the hole block layer 8 is usually selected in the range of 10 to 100 nm.

The electron injecting and transporting layer 5 has a function of transporting electrons received from the cathode 6 to the light emitting layer 4 through the hole blocking layer 8.
As a constituent material of the electron injecting and transporting layer 5, a co-evaporation system (BCP, Cs) of a bathophenanthroline material and Cs is preferably used. In addition, an alkali metal or a compound thereof (for example, lithium fluoride, oxide) Lithium, etc.), alkaline earth metals and their compounds (eg, magnesium fluoride, strontium fluoride, etc.) can be used. The thickness of the electron injecting and transporting layer 5 is usually selected in the range of 0.1 to 100 nm.

As a constituent material of the cathode 6, a material having a small work function, for example, 4 eV or less is preferably used. Examples thereof include a metal film made of Al, Ca, Mg, In, or an alloy film of these metals. And so on.
The thickness of the cathode 6 varies depending on the type of material, but is usually selected in the range of 10 to 1,000 nm, preferably 50 to 200 nm.

Such an organic EL element can be manufactured as follows, for example.
First, the anode 2 is formed on the transparent substrate 1. As a method for forming the anode 2, for example, a vacuum deposition method, a sputtering method, or the like can be used. A commercially available material in which a transparent conductive film such as an ITO film is formed on the surface of a transparent substrate such as a glass substrate can also be used.

  Next, the hole injection transport layer 3 is formed on the formed anode 2. As a method for forming the hole injecting and transporting layer 3, for example, a hole injecting and transporting layer forming liquid is prepared by dissolving a charge injecting and transporting material in an appropriate solvent. The method of apply | coating to and removing a solvent from the obtained coating film can be mentioned.

  Next, the light emitting layer 4 is formed on the formed hole injecting and transporting layer 3. As a method for forming the light emitting layer 4, for example, the composition solution according to the above-described organic EL element material composition is used as a light emitting layer forming liquid, and this light emitting layer forming liquid is applied onto the hole injection transport layer 3, The method of removing a solvent from the obtained coating film can be mentioned.

Thereafter, a hole blocking layer 8, an electron injection transport layer 5 and a cathode 6 are sequentially formed on the formed light emitting layer 4, and the anode 2 and the cathode 6 are electrically connected to a DC power source 7, whereby an organic EL element is obtained. Is obtained.
Examples of the method for forming the hole block layer 8, the electron injection layer 5, and the cathode 6 include a dry method such as a vacuum deposition method.

In this organic EL element, when a DC voltage is applied between the anode 2 and the cathode 6 by the DC power source 7, the light emitting layer 4 emits light, and this light is transmitted to the hole injecting and transporting layer 3, the anode 2, and the transparent element. Radiated to the outside through the substrate 1.
According to the organic EL element having such a configuration, since the light emitting layer 4 is formed of the above-described composition for an organic EL element, high light emission luminance and light emission efficiency can be obtained.
In addition, by providing the hole blocking layer 8 in the organic EL element, the coupling between the holes from the anode 2 and the electrons from the cathode 6 is realized with high efficiency. As a result, higher luminance and luminous efficiency can be obtained. It is done.

  Specific examples of the present invention will be described below, but the present invention is not limited to these examples.

窒素導入管、温度計、還流管を備えた５００ｍＬの３つ口フラスコに、３，５−ジブロモ安息香酸クロリド５．００ｇ、Ｎ−フェニル−ｏ−フェニレンジアミン３．０９ｇを計り取り、窒素雰囲気下ジメチルホルムアミド２１０ｍＬに溶解させた後、室温にて１５時間攪拌した。反応終了後、反応溶液を１．５Ｌの水中に投入し、得られた沈殿物の濾過を行い、さらに十分に水で洗浄した。得られた化合物の精製を、ジメチルホルムアミド／メタノールを用いた再結晶により行い、化合物（１−１−１）を６．００ｇ得た。 Synthesis Example 1 (Synthesis of Compound 1-1-1)

In a 500 mL three-necked flask equipped with a nitrogen introduction tube, a thermometer, and a reflux tube, weigh out 5.00 g of 3,5-dibromobenzoic acid chloride and 3.09 g of N-phenyl-o-phenylenediamine, and in a nitrogen atmosphere After dissolving in 210 mL of dimethylformamide, the mixture was stirred at room temperature for 15 hours. After completion of the reaction, the reaction solution was poured into 1.5 L of water, and the resulting precipitate was filtered and further thoroughly washed with water. The obtained compound was purified by recrystallization using dimethylformamide / methanol to obtain 6.00 g of compound (1-1-1).

窒素導入管、温度計、還流管を備えた１００ｍＬの三口フラスコに、式（１−１−１）の化合物５．００ｇ、ポリりん酸７０ｇを取り窒素雰囲気下１６０℃にて１２時間攪拌した。攪拌終了後反応溶液を８００ｍＬの水中に投入し、得られた沈殿物の濾過を行い、さらに水で十分に洗浄した。得られた化合物の精製を、メタノールを用いた再結晶にて行い、化合物（１−１）３．８４ｇを得た。 Synthesis Example 2 (Synthesis of Compound 1-1)

In a 100 mL three-necked flask equipped with a nitrogen introduction tube, a thermometer, and a reflux tube, 5.00 g of the compound of formula (1-1-1) and 70 g of polyphosphoric acid were taken and stirred at 160 ° C. for 12 hours in a nitrogen atmosphere. After completion of the stirring, the reaction solution was poured into 800 mL of water, and the resulting precipitate was filtered and further washed thoroughly with water. The obtained compound was purified by recrystallization using methanol to obtain 3.84 g of compound (1-1).

Synthesis Example 2 (Synthesis of raw material carbazole ring-containing dihalogen compound)
First, after adding 12.00 g of 3,6-dibromocarbazole and 12.80 g of potassium carbonate to a 500 mL three-necked flask, the mixture was deaerated and then purged with nitrogen, and further 200 ml of N, N-dimethylformamide, 1-iodo-n. -8.0 ml of octane was added and it heated at 70 degreeC for 20 hours, stirring.
Thereafter, the reaction solution was transferred to a separatory funnel, 300 ml of water and 300 ml of ethyl acetate were added and shaken, and then allowed to stand to separate into two layers.
Thereafter, the obtained organic layer was washed with 300 ml of saturated brine, dried over anhydrous magnesium sulfate for 30 minutes, concentrated with an evaporator, and purified with a silica gel-n-hexane column to obtain the following formula (2-1 ) (Hereinafter, referred to as “raw carbazole ring-containing dihalogen compound (2-1)”) 10.05 g. When the purity of this raw material carbazole ring-containing dihalogen compound (2-1) was confirmed by high performance liquid chromatography (HPLC), it was 100%.

Synthesis Example 3 (Synthesis example of raw material boronic acid compound)
Tetrahydrous dehydrated after repeating degassing and nitrogen substitution 3 times by adding 10.00 g of the above-mentioned raw material carbazole ring-containing dihalogen compound (2-1) to a 500 ml three-necked flask equipped with a nitrogen introduction tube and a dropping funnel 114 mL was added and cooled to -78 ° C. Next, 34.7 mL of a 1.58 M n-butyllithium hexane solution was dropped, and the mixture was stirred at -78 ° C for 2 hours. Next, 10.21 g of 2-isopropyl-4,4,5,5-tetramethyl-1,3,2-dioxaborane was added dropwise and stirred at −78 ° C. for 1 hour, and then returned to room temperature and stirred for a whole day and night. After completion of the reaction, the reaction solution was concentrated, dissolved in ethyl acetate, and separated and washed with water. Subsequently, the raw material carbazole ring-containing boronic acid compound (4-1) represented by the following formula (4-1) was simply obtained in a yield of 5.6 g using a developing solvent of hexane: ethyl acetate = 9: 1 on a silica gel column. Released.

[Example 1]
(Polymerization of imidazole-containing polymer (A))
Add 1.611 g of compound (1-1) as a raw material dihalogen compound and 2.000 g of compound (4-1) and 0.174 g of tetrakis (triphenylphosphine) palladium as a raw material boronic acid compound to a three-necked flask with a capacity of 100 mL. After deaeration, the atmosphere was replaced with nitrogen. Next, 19 mL of degassed tetrahydrofuran and 11 mL of 2M potassium carbonate aqueous solution were added with each syringe and refluxed for 24 hours. After completion of the reaction, the reaction solution was transferred to a separatory funnel and separated into two layers. Thereafter, the obtained organic layer was concentrated and dropped into methanol, the precipitate was filtered off and dried under reduced pressure, whereby the ratio of carbazole ring group and imidazole-containing group (k: l) was k: l = 50: 50. As a result, 1.5 g of an imidazole-containing polymer (A) was obtained. The imidazole-containing polymer (A) had Mw of 5,000 and Mn of 3,500.
<Synthesis Example for Comparative Organic EL Device Production>
To a 100 mL three-necked flask, 15 g of 9-vinylcarbazole, 0.0125 g of azobisisobutyronitrile and 30 g of distilled N, N-dimethylformamide were added, and after bubbling with nitrogen for 15 minutes, the temperature was raised to 80 ° C. Raised and polymerized for 4 hours. Thereafter, the reaction solution is dropped into 400 mL of methanol, and the resulting precipitate is filtered off, washed with methanol, and dried under reduced pressure to obtain poly (9-vinylcarbazole) (hereinafter referred to as “polymer (a)”). .) Mw of the polymer (a) was 30,000.

〔実施例３〕
（有機ＥＬ素子用組成物（Ａ−２）の調整）
イミダゾール含有重合体（Ａ）０．１ｇ、上記式（１４−４）で表される電荷輸送性化合物（以下、「ＰＢＤ」という。）を０．０１ｇおよび式（７−１）０．００７ｇをクロロベンゼン３．６ｇに溶解させて有機ＥＬ素子用組成物（Ａ−２）とした。
〔比較例１〕
（比較用有機ＥＬ素子用組成物（ａ）の調整）
重合体（ａ）０．１ｇおよび式（７−１）０．０２ｇをクロロベンゼン４．０ｇに溶解させて比較用有機ＥＬ素子用組成物（ａ）とした。
〔実施例４〕
（有機ＥＬ素子の作製例１）
透明基板上にＩＴＯ膜が形成されてなるＩＴＯ基板を用意し、このＩＴＯ基板を、中性洗剤、超純水、イソプロピルアルコール、超純水、アセトンをこの順に用いて超音波洗浄した後、更に紫外線−オゾン（ＵＶ／Ｏ3 ）洗浄した。
次いで、このＩＴＯ基板のＩＴＯ膜上に、ポリ（３，４−エチレンジオキシチオフェン）−ポリスチレンスルホン酸塩の水溶液をスピンコート法により塗布し、得られた厚さ６５ｎｍの塗膜を窒素雰囲気下２５０℃で３０分間乾燥することにより、正孔注入輸送層を形成した。 [Example 2]
(Adjustment of composition for organic EL device (A-1))
0.1 g of the imidazole-containing polymer (A) and 0.007 g of the formula (7-1) were dissolved in 3.6 g of chlorobenzene to obtain a composition for organic EL devices (A-1).

Example 3
(Adjustment of composition for organic EL device (A-2))
0.1 g of the imidazole-containing polymer (A), 0.01 g of the charge transporting compound represented by the above formula (14-4) (hereinafter referred to as “PBD”) and 0.007 g of the formula (7-1) It was dissolved in 3.6 g of chlorobenzene to obtain an organic EL device composition (A-2).
[Comparative Example 1]
(Adjustment of composition for comparative organic EL device (a))
0.1 g of the polymer (a) and 0.02 g of the formula (7-1) were dissolved in 4.0 g of chlorobenzene to obtain a comparative organic EL device composition (a).
Example 4
(Production Example 1 of Organic EL Element)
An ITO substrate in which an ITO film is formed on a transparent substrate is prepared, and this ITO substrate is ultrasonically cleaned using a neutral detergent, ultrapure water, isopropyl alcohol, ultrapure water, and acetone in this order, and further Washed with UV-ozone (UV / O3).
Next, an aqueous solution of poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate is applied onto the ITO film of the ITO substrate by a spin coating method, and the obtained coating film having a thickness of 65 nm is applied in a nitrogen atmosphere. A hole injecting and transporting layer was formed by drying at 250 ° C. for 30 minutes.

On this hole injecting and transporting layer, the composition for organic EL elements (A-1) was applied as a light emitting layer forming liquid by a spin coating method, and the resulting 40 nm thick coating film was applied at 150 ° C. in a nitrogen atmosphere. The light emitting layer was formed by drying for 10 minutes.
Next, the laminate in which the hole injecting and transporting layer and the light emitting layer are laminated in this order on the ITO film is fixed in a vacuum apparatus, the pressure in the vacuum apparatus is reduced to 1 × 10 ⁻² Pa or less, and TPBI is reduced to 30 nm. A hole blocking layer is formed by vapor deposition to a thickness, and then an electron injection layer is formed by vapor deposition of lithium fluoride to a thickness of 0.5 nm. Further, a Ca metal having a thickness of 30 nm and an Al metal having a thickness of 100 nm. Were deposited in this order to form a cathode. Then, the organic EL element (1) was produced by sealing with glass.

(Characteristic evaluation of organic EL elements)
When the organic EL element (1) is turned on at 100 Cd and the current at that time is kept flowing, the time until the luminance reaches 50 Cd (hereinafter referred to as “half-life”) is measured, and the organic EL element Comparative organic EL element (a) prepared in the same manner as the organic EL element (1) except that the composition (a) for comparison organic EL element was used instead of the composition (A-1) for comparison (a). ), And the durability of the organic EL device (1) was evaluated by the relative half-life when the half-life of the comparative organic EL device (a) was set to 100. Thus, an element having a long service life was obtained.
Further, regarding the organic EL element (1), when the light emitting layer was caused to emit light, the maximum luminance was 20,000 Cd / m 2 and the light emission efficiency was 20 Cd / A.

Example 5
The organic EL device (2) was prepared in the same manner as the organic EL device (1) except that the organic EL device composition (A-2) was used instead of the organic EL device composition (A-1). Produced.
When the characteristics of the organic EL device were evaluated in the same manner as in Example 4, the maximum luminance was 25,000 Cd / m 2, the light emission efficiency was 25 Cd / A, and the durability was 500. Due to the effects of the present invention, the service life was long. An element was obtained.

It is sectional drawing for description which shows an example of a structure of the organic EL element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Anode 3 Hole transport layer 4 Light emitting layer 5 Electron transport layer 6 Cathode 7 DC power supply

Claims (9)

A material for an organic electroluminescence device comprising a structure represented by the following general formula (Ia) and a structure represented by the following general formula (Ib) as repeating units.

[In the above general formula (Ia), T ² is a hydrogen atom, a halogen atom, a monovalent organic group, and T ^{3 to} T ⁶ are a hydrogen atom, a halogen atom, or a monovalent organic that may form a ring. Indicates a group. T ¹ is a direct or divalent organic group, Ar ¹ is an aromatic ring group that may or may not have a substituent, a condensed ring group that may or may not have a substituent, and a substituent. And an organic group having a trivalent conjugated structure selected from these conjugates and a heterocyclic group which may or may not be present. ]

[In the general formula (Ib), R ¹ represents a monovalent organic group, and the general formula (Ib) does not include the structure of the general formula (Ia). ]
An organic electroluminescent element material comprising the structure represented by the following general formula (Ic) in the structure of claim 1 and a content of the structure of 20 mol% or less.
-Ar ² - formula (I-c)
[In the above general formula (Ic), Ar ² contains an Ir atom and may or may not have a substituent, an aromatic ring group, or a condensed group that may or may not have a substituent. An organic group having a divalent conjugated structure selected from a cyclic group, a heterocyclic group which may or may not have a substituent, and a conjugate thereof, wherein the general formulas (Ia) and ( Those not corresponding to Ib) are shown. ]
The structure of claim 1 further includes a structure represented by the following general formula (Id) as a repeating unit, and the content of the component is 50 mol% or less. .

—Ar ³ — general formula (Id)
[In the above general formula (Id), Ar ³ may have a substituent, an aromatic ring group which may or may not have a substituent, a condensed ring group which may or may not have a substituent, a substituent An organic group having a divalent conjugated structure selected from the above-mentioned heterocyclic groups, which may or may not have, and the above general formulas (Ia), (Ib), And those not corresponding to (Ic). ]
The organic electroluminescent element material according to claim 1, wherein T ¹ is represented by the following general formula (II).

[In the above general formula (II), D and E may be the same or different and are selected from -O-, -COO-, -OCO-, -NHCO-, -CONH-, -S-, and direct coupling. T ⁷ and T ⁸ may be the same or different and are each independently selected from a direct bond or an alkylene group having 1 to 20 carbon atoms or an arylene group having 6 to 30 carbon atoms. * Indicates a site binding to the imidazole group, and ● indicates a site binding to Ar ¹ . ]
The organic electroluminescent material according to claim 4, wherein Ar ¹ is selected from the following general formulas (1a-1) to (1a-5).

(* Represents the site that binds to the polymer)
The organic electroluminescent material according to claim 1, wherein T ² is an optionally substituted aryl group having 6 to 30 carbon atoms.
The organic electroluminescent element material according to claim 1, wherein R ¹ is selected from an optionally substituted alkyl group having 1 to 30 carbon atoms or an optionally substituted aryl group having 6 to 30 carbon atoms.
Including the following (a) and (b) as essential components, adding the following (c) and / or (d) as necessary, and subjecting to a polycondensation reaction in the presence of a catalyst containing palladium (Pd) The manufacturing method of the material for organic electroluminescent elements in any one of Claim 1 to 3 characterized by these.

(A) At least one of the compounds represented by the following general formulas (IV-a) and (Va).
(B) At least one of the compounds represented by the following general formulas (IV-b) and (Vb).
(C) At least one of the compounds represented by the following general formulas (IV-c) and (Vc).
(D) At least one of the compounds represented by the following general formulas (IV-d) and (Vd).

V ⁵ -Ar ² -V ⁶ formula (IV-c)
V ⁷ -Ar ³ -V ⁸ general formula (IV-d)
[In the general formula (IV-a), Ar ¹ and T ^{1 to} T ⁶ are the same as those in the general formula (Ia). In the general formula (IV-b), R ¹ is In the general formula (IV-c), Ar ² is the same as that in the general formula (Ic), and in the general formula (IV-d). , Ar ³ is the same as that in the general formula (Id). In the general formulas (IV-a) to (IV-d), V ^{1 to} V ⁸ each independently represent a chlorine atom, a bromine atom, an iodine atom or a trifluoromethanesulfonyloxy group, and may be the same or different. Good. ]

Y ⁵ -Ar ² -Y ⁶ formula (V-c)
Y ⁷ -Ar ³ -Y ⁸ general formula (Vd)
[In the general formula (Va), Ar ¹ and T ^{1 to} T ⁶ are the same as those in the general formula (Ia). In the general formula (Vb), R ¹ is In the general formula (Vc), Ar ² is the same as that in the general formula (Ic), and in the general formula (Vd). , Ar ³ is the same as that in the general formula (Id). In the general formulas (Vb) to (Vd), Y ^{1 to} Y ⁸ each independently represent a monovalent group derived from boric acid, and may be the same or different. ]
An organic electroluminescence device comprising a light emitting layer formed of the material for an organic electroluminescence device according to claim 1.

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