JP2008078495A - Organic electric field light emitting element and its manufacturing method, and image display medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electric field light emitting element having sufficient luminance, excellent in stability and durability, capable of being enlarged in area, and easy to be manufactured. <P>SOLUTION: The organic electric field light emitting element has an organic compound layer between a pair of electrodes, and the organic compound layer contains charge transportation polyurethane having a repetition structure represented by a formulas (I-1) and (I-2). In the formulas (I-1) and (I-2), Ar<SP>1</SP>represents a substituted or unsubstituted monovalent phenyl group, substituted or unsubstituted monovalent polynuclear hydrocarbon with 2-10 aromatic rings, substituted or unsubstituted monovalent condensed aromatic hydrocarbon with 2-10 aromatic rings, or a substituted or unsubstituted monovalent aromatic heterocycle, and X<SP>1</SP>represents a group shown by a formula (II). In the formula (II), Ar<SP>2</SP>represents a substituted or unsubstituted bivalent phenylene group, substituted or unsubstituted bivalent polynuclear hydrocarbon with 2-10 aromatic rings, substituted or unsubstituted bivalent condensed aromatic hydrocarbon with 2-10 aromatic rings, or a substituted or unsubstituted bivalent aromatic heterocycle, X<SP>2</SP>represents a substituted or unsubstituted alkylene group of 1-10C, and n is an integer of 1-10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an organic electroluminescent device using a specific charge transporting polyurethane, a method for producing the organic electroluminescent device, and an image display medium using the organic electroluminescent device.

  An electroluminescent element (hereinafter sometimes referred to as an “EL element”) is a self-luminous all-solid-state element, and is highly visible and resistant to impacts. At present, those using inorganic phosphors are the mainstream. However, since an AC voltage of 200 V or more is required for driving, there are problems such as high manufacturing cost and insufficient brightness.

On the other hand, research on EL devices using organic compounds first started with a single crystal such as anthracene, but in the case of a single crystal, a film thickness of about 1 mm and a driving voltage of 100 V or more were necessary. For this reason, attempts have been made to reduce the thickness by vapor deposition (see, for example, Non-Patent Document 1). However, the thin film obtained by this method still has a high driving voltage of 30 V, a low density of electron and hole carriers in the film, and a low probability of photon generation due to carrier recombination, resulting in sufficient luminance. I couldn't. However, in recent years, in a function-separated EL device in which a thin film of a hole-transporting organic low-molecular compound and a fluorescent organic low-molecular compound having an electron-transporting capability are sequentially stacked by a vacuum deposition method, 1000 cd / s at a low voltage of about 10V. A device capable of obtaining high luminance of m ² or more has been reported (see, for example, Non-Patent Document 2), and research and development of stacked EL devices have been actively conducted since then. These stacked devices are injected into the light emitting layer made of a fluorescent organic compound while maintaining the carrier balance of holes and electrons from the electrode through the charge transporting layer made of the organic compound having a charge transporting property and confined in the light emitting layer. High-luminance light emission is realized by recombination of the generated holes and electrons.

However, in this type of EL element, the following problems are shown for realization.
(1) Since it is driven at a high current density of several mA, a large amount of Joule heat is generated. For this reason, there is a phenomenon in which hole transporting low molecular weight compounds and fluorescent organic low molecular weight compounds formed in an amorphous glass state by vapor deposition are gradually crystallized and finally melted, resulting in a decrease in luminance and dielectric breakdown. It is often observed, and as a result, the lifetime of the device is reduced.

(2) Since a low molecular weight organic compound is formed in a plurality of vapor deposition steps to a thickness of 0.1 μm or less, pinholes are likely to occur, and the film thickness is under strictly controlled conditions to obtain sufficient performance. It is necessary to perform control. Therefore, productivity is low and it is difficult to increase the area.

  In order to solve the problem shown in (1) above, a starburst amine capable of obtaining a stable amorphous glass state is used as a hole transport material (see, for example, Non-Patent Document 3), or the side chain of polyphosphazene is used. An EL device using a polymer compound into which triphenylamine is introduced (see, for example, Non-Patent Document 4) has been reported. However, since these alone have an energy barrier due to the ionization potential of the hole transport material, they do not satisfy the hole injection property from the anode or the hole injection property to the light emitting layer. In the case of the former starburst amine, since the solubility is small, it is difficult to purify and it is difficult to increase the purity, and in the case of the latter polymer compound, a high current density cannot be obtained and sufficient brightness is obtained. There are also problems such as not being obtained.

  Next, in order to solve the problem shown in (2), research and development of an organic EL element having a single-layer structure capable of shortening the process is underway, and a conductive polymer such as poly (p-phenylene vinylene) is used. Although the element used (for example, refer nonpatent literature 5) and the element which mixed the electron transport material and the fluorescent pigment in hole transportable polyvinyl carbazole (for example, refer nonpatent literature 6) are proposed, it is still. Luminance and luminous efficiency are inferior to those of stacked organic EL devices using organic low-molecular compounds.

Also, from the viewpoint of manufacturing methods, wet coating methods have been studied in terms of manufacturing simplification, workability, large area, cost, etc., and it has been reported that elements can also be obtained by casting methods ( For example, refer nonpatent literature 7 and 8.). However, since the charge transport material is poorly soluble and compatible with the solvent and the resin, it is easy to crystallize, and there is a problem in production or characteristics.
Thin Solid Films, Vol. 94,171, (1982) Applied Physics Letter, Vol. 51,913 (1987) Proceedings of the 40th Joint Conference on Applied Physics 30a-SZK-14 (1993) 42nd Polymer Symposium Proceedings 20J21 (1993) Nature, Vol. 357, 477 (1992) Proceedings of the 38th Joint Conference on Applied Physics 31pg-12 (1991) Proceedings of the 50th Japan Society of Applied Physics 29p-ZP-5 (1989) Proceedings of the 51st Japan Society of Applied Physics 28a-PB-7 (1990)

  The present invention has been made in view of the above-described conventional problems, and its purpose is to have sufficient luminance, excellent stability and durability, and capable of large area, and easy to manufacture. An organic electroluminescent device, a method for manufacturing the same, and an image display medium using the organic electroluminescent device.

  As a result of intensive studies to achieve the above object, the present inventors can obtain charge mobility and thin film forming ability suitable for an organic electroluminescence device by using a charge transporting polyurethane having a specific repeating structure. As a result, the present invention has been completed.

That is, the present invention
<1> At least one of the organic compound layers is formed between a pair of electrodes composed of an anode and a cathode that are transparent or translucent, and at least one of the organic compound layers is represented by the following general formula (I- 1. An organic electroluminescence device comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by 1) and (I-2) as a partial structure.

[In the general formulas (I-1) and (I-2), Ar ¹ represents a substituted or unsubstituted monovalent phenyl group, a substituted or unsubstituted monovalent polynuclear aromatic carbon atom having 2 to 10 aromatic rings. Represents hydrogen, a substituted or unsubstituted monovalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted monovalent aromatic heterocyclic ring, and X ¹ is represented by the following general formula (II): Represents a group. ]

[In the general formula (II), Ar ² represents a substituted or unsubstituted divalent phenylene group, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted aromatic Represents a divalent condensed aromatic hydrocarbon having 2 to 10 rings or a substituted or unsubstituted divalent aromatic heterocyclic ring, X ² represents a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, n represents an integer of 1 to 10. ]

<2> The organic compound layer includes at least a light emitting layer and an electron transport layer, and at least one of the light emitting layer and the electron transport layer is represented by the general formulas (I-1) and (I-2). The organic electroluminescent element as described in <1> above, comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the structure as a partial structure.
<3> The organic electroluminescent element according to <2>, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane.
<4> The organic compound layer includes at least a hole transport layer, a light emitting layer, and an electron transport layer, and at least any one of the hole transport layer, the light emitting layer, and the electron transport layer has the general formula ( The organic material according to <1>, comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by I-1) and (I-2) as a partial structure An electroluminescent element.
<5> The organic electroluminescence device according to <4>, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane.
<6> The organic compound layer includes at least a hole transport layer and a light emitting layer, and at least one of the hole transport layer and the light emitting layer is represented by the general formulas (I-1) and (I-2). The organic electroluminescent device according to <1>, further comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the structures shown as a partial structure.
<7> The organic electroluminescent element according to <6>, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane.
<8> The organic compound layer is composed only of a light emitting layer having charge transporting ability, and the light emitting layer is at least one selected from the structures represented by the general formulas (I-1) and (I-2). <1>, characterized in that it comprises a charge transporting polyurethane having a repeating unit containing as a partial structure, and having a buffer layer between the light emitting layer having the charge transporting ability and the anode. It is an organic electroluminescent element.
<9> The organic electroluminescent element according to <8>, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane.

  <10> A charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure is represented by the following general formula (III-1): Or it is a charge transportable polyurethane shown by (III-2), It is an organic electroluminescent element as described in any one of said <1>-<9> characterized by the above-mentioned.

[In General Formulas (III-1) and (III-2), A represents at least one selected from the structures represented by General Formulas (I-1) and (I-2); Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, and T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or carbon Represents a divalent branched hydrocarbon group of 2 to 10, Y and Z each represents a substituted or unsubstituted divalent alkylene group or a substituted or unsubstituted divalent aromatic group; , 0 or 1, and p represents an integer of 5 to 5,000. ]

  <11> The method according to any one of <1> to <10>, wherein one or more organic compound layers are provided between a pair of electrodes including an anode and a cathode, at least one of which is transparent or translucent. An organic electroluminescent device manufacturing method for manufacturing an organic electroluminescent device, comprising at least a coating step of coating a coating solution obtained by dissolving constituent components of the organic compound layer in a solvent by ink jet printing. It is a manufacturing method of an organic electroluminescent element.

  <12> An image display medium comprising the organic electroluminescence device according to any one of <1> to <10> arranged in at least one of a matrix shape and a segment shape. .

  According to the present invention, an organic electroluminescence device having sufficient luminance, excellent stability and durability, capable of increasing the area, and easy to produce, and its production method, and the organic electroluminescence device are used. Image display medium can be provided.

  The organic electroluminescent device of the present invention is an electroluminescent device comprising one or a plurality of organic compound layers sandwiched between a pair of electrodes, at least one of which is transparent or translucent. At least one of the layers contains a charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by the following general formulas (I-1) and (I-2) as a partial structure; To do.

  In this organic electroluminescence device, at least one of the organic compound layers contains the charge transporting polyurethane, so that it has sufficient luminance and is excellent in stability and durability. Further, by using the charge transporting polyurethane, it is possible to increase the area and to manufacture easily.

[In the general formulas (I-1) and (I-2), Ar ¹ represents a substituted or unsubstituted monovalent phenyl group, a substituted or unsubstituted monovalent polynuclear aromatic carbon atom having 2 to 10 aromatic rings. Represents hydrogen, a substituted or unsubstituted monovalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted monovalent aromatic heterocyclic ring, and X ¹ is represented by the following general formula (II): Represents a group. ]

[In the general formula (II), Ar ² represents a substituted or unsubstituted divalent phenylene group, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted aromatic Represents a divalent condensed aromatic hydrocarbon having 2 to 10 rings or a substituted or unsubstituted divalent aromatic heterocyclic ring, X ² represents a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, n represents an integer of 1 to 10. ]

Since the charge transporting polyurethane can impart both functions of a hole transporting ability and an electron transporting ability by appropriately selecting a structure to be described later, a hole transporting layer, a light emitting layer, an electron depending on the purpose. It can be used for any layer such as a transport layer.
Hereinafter, in describing the present invention in detail, first, the charge transporting polyurethane in the present invention will be described in detail.

-Charge transporting polyurethane-
In the general formulas (I-1) and (I-2), Ar ¹ represents a substituted or unsubstituted monovalent phenyl group, a substituted or unsubstituted monovalent polynuclear aromatic carbon having 2 to 10 aromatic rings. It represents hydrogen, a substituted or unsubstituted monovalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted monovalent aromatic heterocyclic ring. The two Ar ¹ present in the general formulas (I-1) and (I-2) may be the same or different, but may be the same from the viewpoint of manufacturability. preferable.

In the general formulas (I-1) and (I-2), the number of aromatic rings constituting the polynuclear aromatic hydrocarbon and the condensed aromatic hydrocarbon selected as the structure representing Ar ¹ is further 2 to 5 In the condensed aromatic hydrocarbon, an aromatic hydrocarbon in which all aromatic rings are condensed is preferable. In the present invention, the polynuclear aromatic hydrocarbon and the condensed aromatic hydrocarbon specifically mean a polycyclic aromatic as defined below.
That is, the “polynuclear aromatic hydrocarbon” represents a hydrocarbon compound in which two or more aromatic rings composed of carbon and hydrogen are present and these aromatic rings are bonded to each other through a carbon-carbon bond. Specific examples include biphenyl, terphenyl, stilbene and the like. In addition, “condensed aromatic hydrocarbon” refers to a carbon atom in which two or more aromatic rings composed of carbon and hydrogen exist, and these aromatic rings share a pair of adjacent bonded carbon atoms. Represents a hydrogen compound. Specific examples include naphthalene, anthracene, phenanthrene, pyrene, perylene, and fluorene.

Furthermore, in the general formulas (I-1) and (I-2), the aromatic heterocyclic ring selected as the structure representing Ar ¹ represents an aromatic ring including elements other than carbon and hydrogen. Nr = 5 and / or 6 is preferably used as the number of atoms (Nr) constituting the ring skeleton. Further, the type and number of atoms (heterogeneous atoms) other than carbon atoms constituting the ring skeleton are not limited. For example, a sulfur atom, a nitrogen atom, an oxygen atom and the like are preferably used. / Or two or more hetero atoms may be contained. In particular, as the heterocyclic ring having a 5-membered ring structure, thiophene, thiophine, pyrrole, furan, or a heterocyclic ring in which the 3- and 4-position carbons thereof are further substituted with nitrogen is preferably used. A pyridine ring is preferably used as the ring.
These may be either all composed of a conjugated system or partly composed of a conjugated system, but those composed entirely of a conjugated system are preferred in terms of charge transportability and light emission efficiency.

In the general formulas (I-1) and (I-2), examples of the substituent substituted for each group represented by Ar ¹ include a hydrogen atom, an alkyl group, an alkoxy group, a phenoxy group, an aryl group, an aralkyl group, A substituted amino group, a halogen atom, etc. are mentioned. As said alkyl group, a C1-C10 thing is preferable, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a hexyl group etc. are mentioned. As said alkoxy group, a C1-C10 thing is preferable, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group etc. are mentioned. As said aryl group, a C6-C20 thing is preferable, for example, a phenyl group, a toluyl group, etc. are mentioned. As said aralkyl group, a C7-C20 thing is preferable, for example, a benzyl group, a phenethyl group, etc. are mentioned. Examples of the substituent in the substituted amino group include an alkyl group, an aryl group, and an aralkyl group, and specific examples are the same as described above.

In General Formulas (I-1) and (I-2), X ¹ represents a substituted or unsubstituted divalent aromatic group represented by General Formula (II).

In the general formula (II), Ar ² represents a substituted or unsubstituted divalent phenylene group, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted aromatic It represents a divalent fused aromatic hydrocarbon having 2 to 10 rings or a substituted or unsubstituted divalent aromatic heterocyclic ring. Here, the “polynuclear aromatic hydrocarbon”, “fused ring aromatic hydrocarbon”, and “aromatic heterocycle” are as already described in the section of Ar ¹ . Preferred examples of the divalent phenylene group, divalent polynuclear aromatic hydrocarbon, divalent condensed aromatic hydrocarbon and divalent aromatic heterocyclic ring are the monovalent enumerated in the section for Ar ¹ . Specific examples include divalent hydrogen atoms removed from one atom.
In general formula Ar ² that there are two in (II) it is not may also be the same or different and are preferably the same from the viewpoint of easy production.

In the general formula (II), the alkylene group having 1 to 10 carbon atoms represented by X ^2, for example, methylene group, ethylene group, propylene group, butylene group.
In addition, examples of the substituent substituted on the alkylene group include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group.
Among these (substituted) alkylene groups, an ethylene group, a propylene group, a butylene group, a methylethylene group, and an ethylethylene group are more preferable.

In general formula (II), when n = 2 or more, the two existing X ² may be the same or different, but are preferably the same from the viewpoint of manufacturability. Here, the “same” includes a case where the substitution position is axisymmetric arrangement in the case of having a substituent as shown in [Structure 25] shown in Table 2 below.

  In general formula (II), n represents an integer of 1 to 10, and preferably 2 to 5.

  Here, the preferable specific example of the structure shown by the said general formula (I-1) is shown.

  Moreover, the preferable specific example of the structure shown by the said general formula (I-2) is shown below.

  The charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure includes the following general formulas (III-1) and (III) The polyurethane represented by III-2) is preferably used.

[In General Formulas (III-1) and (III-2), A represents at least one selected from the structures represented by General Formulas (I-1) and (I-2); Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, and T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or carbon Represents a divalent branched hydrocarbon group of 2 to 10, Y and Z each represents a substituted or unsubstituted divalent alkylene group or a substituted or unsubstituted divalent aromatic group; , 0 or 1, and p represents an integer of 5 to 5,000. ]

  In the general formulas (III-1) and (III-2), A represents at least one selected from the structures represented by the general formulas (I-1) and (I-2). The plurality of A present in the polyurethanes represented by -1) and (III-2) may have the same structure or different structures.

In general formulas (III-1) and (III-2), R represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group.
As said alkyl group, a C1-C10 thing is preferable, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group etc. are mentioned. As an aryl group, a C6-C20 thing is preferable, for example, a phenyl group, a toluyl group, etc. are mentioned. As the aralkyl group, those having 7 to 20 carbon atoms are preferable, and examples thereof include a benzyl group and a phenethyl group. In addition, examples of the substituent of the substituted alkyl, substituted aryl, and substituted aralkyl group include a hydrogen atom, an alkyl group, an alkoxy group, a substituted amino group, and a halogen atom.

  In general formula (III-1) or (III-2), T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent branched hydrocarbon group having 2 to 10 carbon atoms. And preferably selected from a divalent linear hydrocarbon group having 2 to 6 carbon atoms or a divalent branched hydrocarbon group having 3 to 7 carbon atoms. Among these, more specifically, the divalent hydrocarbon groups shown below are particularly preferable.

In the general formulas (III-1) and (III-2), the two-(T) _m- existing across A are different even if the value of m and T are the same. It doesn't matter. In general formulas (III-1) and (III-2), a plurality of — (T) _m — may be the same or different. However, from the viewpoint of ease of production, it is preferable _that- (T) _m -in general formulas (III-1) and (III-2) are the same.

In general formulas (III-1) and (III-2), Y and Z represent a substituted or unsubstituted divalent alkylene group or a substituted or unsubstituted divalent aromatic group.
More specifically, when the polyurethane is synthesized by the method described later, Y represents a diisocyanate residue or a diamine residue, and Z represents a dihydric alcohol residue or a bischloroformate residue. To express.
Specific examples of Y and Z include groups selected from the following formulas (IV-1) to (IV-7).

[In the above formulae, R ¹¹ and R ¹² are each a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms, or a substituted or unsubstituted phenyl group. A group, a substituted or unsubstituted aralkyl group, a and b each independently represent an integer of 1 to 5, d and f each independently represent 0 or 1, and c and e each independently Represents an integer of 0 to 2, and V represents a group represented by the following formulas (V-1) to (V-11). ]

[In the above formulas (V-1), (V-10) and (V-11), g represents an integer of 1 to 5, and h and i represent an integer of 0 to 5. ]

  In general formulas (III-1) and (III-2), m represents 0 or 1, and p represents an integer of 5 to 5,000, preferably in the range of 10 to 1,000.

Here, preferred specific examples of the charge transporting polyurethane represented by the general formulas (III-1) and (III-2) are shown, but the present invention is not limited to these specific examples. In the table below, the numbers in the column A in the monomer column correspond to the structure numbers of specific examples of the structures represented by the general formulas (I-1) and (I-2). In the case where the Z column is “-”, specific examples of the charge transporting polyurethane represented by the general formula (III-1) are shown, and the others are specific examples of the charge transporting polyurethane shown by (III-2). Indicates.
In the following table, each specific example of the charge transporting polyurethane having a compound number assigned to the polymer column, for example, the specific example having a number of 15 is hereinafter referred to as “charge transporting polyurethane (15)”.

The weight average molecular weight Mw of the charge transporting polyurethane is preferably in the range of 5,000 to 1,000,000, and more preferably in the range of 10,000 to 300,000.
Here, the weight average molecular weight Mw can be measured by the following method.
The charge transporting polyurethane was dissolved in THF (tetrahydrofuran) to make a 0.1% by mass solution, filtered through a 0.1 μm PTFE filter, and the prepared solution was subjected to gel permeation chromatography (GPC / manufactured by Tosoh Corporation). Measured with HLC-8120GPC (in terms of styrene).

(Synthesis of charge transporting polyurethane)
Subsequently, the charge transporting polyurethanes represented by the general formulas (III-1) and (III-2) include, for example, charge transporting monomers represented by the following structural formulas (VI-1) to (VI-4), It can be synthesized by polymerizing by a known method described in the 4th edition, Experimental Chemistry Course Vol. 28 (Edited by Chemical Society of Japan, Maruzen, 1992), New Polymer Experiments Vol. 2 (Kyoritsu Shuppan, 1995), etc. .

[In Structural Formulas (VI-1) to (VI-4), A, T, and m are the same as A, T, and m in General Formula (III-1) or (III-2). ]

  First, a method for synthesizing the charge transporting monomers represented by the structural formulas (VI-1) to (VI-4) will be described. In addition, the monomer used as the raw material of the charge transporting polymer of the present invention can be synthesized by a known method, and for example, can be obtained according to the following synthesis route.

[In the above synthetic route, Ar ¹ is the same as defined above general formula (I-1) and the Ar ¹ in (I-2), ^{X 2} and Ar ^2, and ^{X 2} and Ar ² in the general formula (II) It is. G represents an iodine or bromine atom, B represents a hydrogen atom,-(T) _m -OH,-(T) _m -NCO,-(T) _m -OC (= O) Cl or-(T) _m-. NH ₂ , n ′ represents an even number of integers from 1 to 10, and k represents 1 or 2. NBS represents N-bromosuccinimide, and NCS represents N-chlorosuccinimide. ]

  In particular, when the compound represented by the structural formula (VI-1) is used, when B is a hydrogen atom in the above synthesis route, for example, 4th edition Experimental Chemistry Course Vol. 21, JP-A-7-61955 As described in the publication, etc., after obtaining a formyl body by the Vilsmeier method, it can be easily synthesized by reducing with a reducing agent such as a borohydride salt or an aluminum hydride salt, and the compound stability Is also preferable because it is high.

  Using the charge transporting monomers represented by the structural formulas (VI-1) to (VI-4) obtained as described above, polymerization is carried out by a known method, whereby the above general formulas (III-1) and ( A charge transporting polyurethane represented by III-2) can be synthesized. Specifically, the following synthesis methods can be mentioned.

[1] In the case of structural formulas (VI-1) and (VI-2) When the charge transporting monomer is a dihydric alcohol represented by the structural formula (VI-1), the diisocyanate represented by OCN-Y-NCO In the case where the charge transporting monomer is a diisocyanate represented by the structural formula (VI-2), it is mixed in an equivalent amount with a dihydric alcohol represented by HO-Z-OH. Is used for polymerization. Here, said Y and Z are the same as Y and Z in general formula (III-1) or (III-2), and are the same also in the following.

  As a catalyst, what is used for normal polyurethane synthesis reactions, such as organometallic compounds, such as dibutyltin (II) dilaurate, dibutyltin diacetate (II), and lead naphthenate, can be used. Further, when an aromatic diisocyanate is used for the synthesis of a charge transporting polyurethane, a tertiary amine such as triethylenediamine can be used as a catalyst. These organometallic compounds and tertiary amines may be used as a mixture. The amount of the catalyst is used in the range of 1 / 10,000 to 1/10 parts by weight, preferably 1 / 1,000 to 1/50 parts by weight with respect to 1 part by weight of the charge transporting monomer.

  Any solvent can be used as long as it dissolves the charge transporting monomer and diisocyanate or dihydric alcohol. However, from the viewpoint of reactivity, a hydrogen bond with a less polar solvent or alcohol is generated. It is preferable to use a non-solvent, and toluene, chlorobenzene, dichlorobenzene, 1-chloronaphthalene and the like are effective. The amount of the solvent is 1 to 100 parts by mass, preferably 2 to 50 parts by mass with respect to 1 part by mass of the charge transporting monomer. Moreover, reaction temperature can be set arbitrarily.

  After completion of the reaction, the reaction solution is dropped as it is into a poor solvent in which polyurethanes such as methanol and ethanol and polyurethane such as acetone are difficult to dissolve, and the charge transporting polyurethane is precipitated and separated, and then water or organic Wash thoroughly with solvent and dry. Furthermore, if necessary, the reprecipitation treatment may be repeated in which it is dissolved in a suitable organic solvent and dropped into a poor solvent to precipitate the charge transporting polyurethane. The reprecipitation treatment is preferably carried out with efficient stirring with a mechanical stirrer or the like. The solvent for dissolving the charge transporting polyurethane in the reprecipitation treatment is used in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight with respect to 1 part by weight of the charge transporting polyurethane. The poor solvent is used in an amount of 1 to 1,000 parts by weight, preferably 10 to 500 parts by weight, based on 1 part by weight of the charge transporting polyurethane.

[2] In the case of structural formulas (VI-3) and (VI-4) When the charge transporting monomer is bischloroformate represented by the structural formula (VI-3), H ₂ N—Y—NH ₂ In the case where the charge transporting monomer is a diamine represented by the structural formula (VI-4), it is mixed in an equivalent amount with a bischloroformate represented by ClOCO-Z-OCOCl. Both are polymerized using a catalyst.

  As the solvent, methylene chloride, dichloroethane, trichloroethane, tetrahydrofuran (THF), toluene, chlorobenzene, 1-chloronaphthalene and the like are effective, and 1 to 100 parts by mass, preferably 2 with respect to 1 part by mass of the charge transporting monomer. It is used in the range of ˜50 parts by mass. Moreover, reaction temperature can be set arbitrarily. After completion of the reaction, it can be purified by reprecipitation treatment as described above.

In addition, when the basicity of the diamine represented by H ₂ N—Y—NH ₂ is high, an interfacial polymerization method can also be used. That is, by adding diamines to water and adding an equivalent amount of acid to dissolve, the diamines and an equivalent charge transporting monomer solution represented by the above structural formula (IV-3) are added with vigorous stirring. Can be polymerized. Under the present circumstances, water is used in 1-1000 mass parts with respect to 1 mass part of diamines, Preferably it is 10-500 mass parts.

  As the solvent for dissolving the charge transporting monomer, methylene chloride, dichloroethane, trichloroethane, toluene, chlorobenzene, 1-chloronaphthalene and the like are effective. The reaction temperature can be arbitrarily set, and in order to promote the reaction, it is effective to use a phase transfer catalyst such as an ammonium salt or a sulfonium salt. The phase transfer catalyst is used in an amount of 0.1 to 10 parts by mass, preferably 0.2 to 5 parts by mass, with respect to 1 part by mass of the charge transporting monomer.

-Organic electroluminescence device-
Next, the organic electroluminescent element of the present invention will be described in detail.
The organic electroluminescent element of the present invention is composed of a pair of electrodes, at least one of which is transparent or translucent, and one or a plurality of organic compound layers including a light emitting layer sandwiched between the electrodes. The layer configuration is not particularly limited as long as it contains at least one kind of charge transporting polyurethane as described above in at least one layer.

  In the organic electroluminescent device of the present invention, when there is one organic compound layer, the organic compound layer means a light emitting layer having charge transporting ability, and the light emitting layer contains the charge transporting polyurethane. On the other hand, when there are a plurality of organic compound layers (that is, in the case of a function separation type in which each layer has a different function), at least one of the layers is a light emitting layer, and this light emitting layer is a light emitting layer having a charge transporting ability. Also good. In this case, the following (1) to (3) can be given as specific examples of the layer structure composed of the light emitting layer or the light emitting layer having the charge transporting capability and other layers.

(1) A layer configuration including a light emitting layer and an electron transport layer and / or an electron injection layer.
(2) A layer configuration including a hole transport layer and / or a hole injection layer, a light emitting layer, and an electron transport layer and / or an electron injection layer.
(3) A layer structure formed from a hole transport layer and / or a hole injection layer and a light emitting layer.

  The layers other than the light emitting layer having these layer configurations (1) to (3) and the light emitting layer having charge transporting capability have a function as a charge transport layer or a charge injection layer.

  In any one of the layer configurations (1) to (3), the charge transporting polyurethane may be contained in any one layer.

  In the organic electroluminescence device of the present invention, the light-emitting layer, the hole transport layer, the hole injection layer, the electron transport layer, and the electron injection layer are formed of a charge transport compound other than the charge transport polyurethane (hole transport property). A compound, an electron transporting compound). Details of such charge transporting compounds will be described later.

Hereinafter, although it demonstrates in detail, referring drawings, it is not necessarily limited to these.
1 to 4 are schematic cross-sectional views for explaining the layer structure of the organic electroluminescent element of the present invention. In the case of FIGS. 1, 2, and 3, there are a plurality of organic compound layers. FIG. 4 shows an example in which there is one organic compound layer. In FIG. 1 to FIG. 4, components having similar functions are described with the same reference numerals.

  The organic electroluminescent device shown in FIG. 1 is obtained by sequentially laminating a transparent electrode 2, a light emitting layer 4, an electron transport layer and / or an electron injection layer 5, and a back electrode 7 on a transparent insulator substrate 1. This corresponds to the configuration (1). However, when the layer denoted by reference numeral 5 is composed of an electron transport layer and an electron injection layer, the electron transport layer, the electron injection layer, and the back electrode 7 are laminated in this order on the back electrode 7 side of the light emitting layer 4. .

  The organic electroluminescent device shown in FIG. 2 includes a transparent electrode 2, a hole transport layer and / or a hole injection layer 3, a light emitting layer 4, an electron transport layer and / or an electron injection layer 5 on a transparent insulator substrate 1. The back electrode 7 is sequentially laminated, and corresponds to the layer configuration (2). However, when the layer indicated by reference numeral 3 is composed of a hole transport layer and a hole injection layer, the hole injection layer, the hole transport layer, and the light emitting layer 4 are provided on the back electrode 7 side of the transparent electrode 2. Laminated sequentially. When the layer indicated by reference numeral 5 is composed of an electron transport layer and an electron injection layer, the electron transport layer, the electron injection layer, and the back electrode 7 are laminated in this order on the back electrode 7 side of the light emitting layer 4. .

  The organic electroluminescent element shown in FIG. 3 is obtained by sequentially laminating a transparent electrode 2, a hole transport layer and / or a hole injection layer 3, a light emitting layer 4 and a back electrode 7 on a transparent insulator substrate 1. This corresponds to the layer configuration (3). However, when the layer indicated by reference numeral 3 is composed of a hole transport layer and a hole injection layer, the hole injection layer, the hole transport layer, and the light emitting layer 4 are provided on the back electrode 7 side of the transparent electrode 2. Laminated sequentially.

  The organic electroluminescent element shown in FIG. 4 is obtained by sequentially laminating a transparent electrode 2, a light emitting layer 6 having a charge transporting capability, and a back electrode 7 on a transparent insulator substrate 1.

Each will be described in detail below.
The charge transporting polyurethane in the present invention can be imparted with either a hole transport ability or an electron transport ability depending on the function of the organic compound layer contained therein.
For example, the charge transporting polyurethane may be contained in either the light emitting layer 4 or the electron transporting layer 5 in the case of the layer configuration of the organic electroluminescent device shown in FIG. Either can work. 2 may be contained in any of the hole transport layer 3, the light emitting layer 4, and the electron transport layer 5, and the hole transport layer 3, the light emitting layer 4, and the organic electroluminescent element shown in FIG. Any of the electron transport layers 5 can act. Furthermore, in the case of the layer configuration of the organic electroluminescent element shown in FIG. 3, it may be contained in either the hole transport layer 3 or the light emitting layer 4, and both act as the hole transport layer 3 and the light emitting layer 4. Can do. Furthermore, in the case of the layer structure of the organic electroluminescent element shown in FIG. 4, it can be contained in the light emitting layer 6 having the charge transporting ability and act as the light emitting layer 6 having the charge transporting ability.

  In the case of the layer configuration of the organic electroluminescence device shown in FIGS. 1 to 4, the transparent insulator substrate 1 is preferably transparent in order to extract emitted light, and glass, plastic film, etc. are used, but not limited thereto. Absent. Further, the transparent electrode 2 is preferably transparent so as to extract emitted light in the same manner as the transparent insulator substrate, and has a high work function for injecting holes. Indium tin oxide (ITO), tin oxide (NESA) ), Oxide films such as indium oxide and zinc oxide, and vapor deposited or sputtered gold, platinum, palladium and the like are used, but not limited thereto.

  In the case of the layer configuration of the organic electroluminescent element shown in FIGS. 1 and 2, the electron transport layer 5 may be formed of the charge transporting polyurethane alone provided with a function (electron transport ability) according to the purpose. In order to adjust the electron mobility for the purpose of further improving the electrical characteristics, the electron transporting compound other than the above-described charge transporting polyurethane of the present invention is contained in the range of 1% by mass to 50% by mass. It may be formed by dispersion and mixing. As such an electron transporting material, an oxadiazole derivative, a nitro-substituted fluorenone derivative, a diphenoquinone derivative, a thiopyrandioxide derivative, a fluorenylidenemethane derivative, and the like are preferable. Preferable specific examples include, but are not limited to, the following exemplary compounds (VII-1) to (VII-3). Moreover, you may combine with several electron transport material instead of single. In the case where the charge transporting polyurethane is not used, these electron transport materials are formed singly or in combination.

  In the case of the layer configuration of the organic electroluminescent element shown in FIGS. 2 and 3, the hole transport layer 3 is formed of the charge transporting polyurethane alone provided with a function (hole transport ability) according to the purpose. However, in order to adjust the hole mobility for the purpose of further improving the electrical characteristics, 1% by mass to 50% by mass of the hole transporting compound other than the above-described charge transporting polyurethane of the present invention. % May be mixed and dispersed. Examples of such hole transporting compounds include tetraphenylenediamine derivatives, triphenylamine derivatives, carbazole derivatives, stilbene derivatives, arylhydrazone derivatives, porphyrin compounds, and the like. VIII-1) to (VIII-9). Among these, a tetraphenylenediamine derivative is preferable because of its good compatibility with the charge transporting polyurethane. Moreover, the mixture with other general purpose resin etc. may be sufficient. In the case where the charge transporting polyurethane is not used, these hole transporting compounds are formed alone or in combination.

  Here, in the exemplary compounds (VIII-7) to (VIII-9), x represents an integer of 5 to 5,000, and n represents an integer of 5 to 5,000.

  In the case of the layer configuration of the organic electroluminescence device shown in FIGS. 1 to 3, the light emitting layer 4 uses a compound showing a high fluorescence quantum yield in the solid state as a light emitting material. When the light emitting material is an organic low molecular weight compound, it is a condition that a favorable thin film can be formed by applying a vacuum deposition method or applying and drying a solution or dispersion containing the organic low molecular weight compound and a binder resin. In the case of an organic polymer compound, it is a condition that a good thin film can be formed by applying and drying a solution or dispersion containing itself. For organic low molecular weight compounds, chelate type organometallic complexes, polynuclear / fused aromatic ring compounds, perylene derivatives, coumarin derivatives, styrylarylene derivatives, silole derivatives, oxazole derivatives, oxathiazole derivatives, oxadiazole derivatives, etc. In the case of a polymer compound, polyparaphenylene derivatives, polyparaphenylene vinylene derivatives, polythiophene derivatives, polyacetylene derivatives, polyfluorene derivatives and the like can be mentioned. As preferred specific examples, the following compounds (IX-1) to (IX-17) are used, but are not limited thereto.

[In Structural Formulas (IX-13) to (IX-17), n and x each independently represent an integer of 1 or more, and y represents 0 or 1. In formulas (IX-16) and (IX-17), Ar represents a substituted or unsubstituted monovalent or divalent aromatic group, and X represents a substituted or unsubstituted divalent aromatic group. ]

  Further, for the purpose of improving the durability or the luminous efficiency of the organic electroluminescent device, the light emitting material may be doped with a dye compound different from the light emitting material as a guest material. When the light emitting layer is formed by vacuum evaporation, doping can be performed by co-evaporation. When the light emitting layer is formed by applying and drying a solution or dispersion, the light emitting layer is mixed in the solution or dispersion. Thus, doping can be performed. The doping ratio of the dye compound in the light emitting layer is 0.001% by mass to 40% by mass, preferably 0.01% by mass to 10% by mass. As the coloring compound used for such doping, an organic compound that has good compatibility with the light emitting material and does not prevent the formation of a good thin film of the light emitting layer is used, preferably a DCM derivative, a quinacridone derivative, a rubrene derivative. And porphyrin-based compounds. As preferred specific examples, the following compounds (X-1) to (X-4) are used, but are not limited thereto.

  In addition, the light emitting layer 4 may be formed of the light emitting material alone, but for the purpose of further improving the electric characteristics and the light emitting characteristics, the light emitting material contains 1% by mass of the charge transporting polyurethane in the present invention. Alternatively, it may be formed by mixing and dispersing in the range of 50% by mass. Alternatively, a charge transporting compound (electron transporting compound, hole transporting compound) other than the charge transporting polyurethane may be mixed and dispersed in the light emitting material in the range of 1% by mass to 50% by mass. Good. Further, when the charge transporting polyurethane in the present invention also has a light emitting property, it may be used as a light emitting material. In that case, for the purpose of further improving the electrical property and the light emitting property, the light emitting material is used. A charge transporting compound other than the charge transporting polyurethane may be mixed and dispersed in the range of 1% by mass to 50% by mass.

  In the case of the layer configuration of the organic electroluminescent element shown in FIG. 4, the light emitting layer 6 having a charge transporting capability has a function (hole transporting capability or electron transporting capability) according to the purpose. A light-emitting material other than the charge-transporting polyurethane (preferably, at least one selected from the light-emitting materials (IX-1) to (IX-17) is 50% by mass or less). Although it is a dispersed organic compound layer, in order to adjust the balance between holes and electrons injected into the organic electroluminescence device, 10% by mass to 50% by mass of the charge transporting compound other than the charge transporting polyurethane of the present invention. % May be dispersed. Examples of such a charge transporting compound include an oxadiazole derivative, a nitro-substituted fluorenone derivative, a diphenoquinone derivative, a thiopyrandioxide derivative, a fluorenidenemethane derivative, and the like as an electron transport material when adjusting electron mobility. . Preferable specific examples include the exemplified compounds (VII-1) to (VII-3).

  In addition, it is preferable to use an organic compound that does not exhibit a strong interaction with the charge transporting polyurethane of the present invention, and the following exemplified compound (XI) is more preferably used, but it is not limited thereto.

  When adjusting the hole mobility at the same time, preferred examples of the hole transporting compound include tetraphenylenediamine derivatives, triphenylamine derivatives, carbazole derivatives, stilbene derivatives, arylhydrazone derivatives, porphyrin compounds, and the like. Specific examples thereof include the above-described exemplary compounds (VIII-1) to (VIII-9), and a tetraphenylenediamine derivative is preferred because of its good compatibility with the charge transporting polyurethane.

In the case of the layer structure of the organic electroluminescent element shown in FIGS. 1 to 4, a metal having a low work function is generally used for the back electrode 7 because it can be vacuum-deposited and performs electron injection, but magnesium is particularly preferable. , Aluminum, silver, indium and alloys thereof, metal halide compounds such as lithium fluoride and lithium oxide, and metal oxides. Further, a protective layer may be provided on the back electrode 7 in order to prevent the element from being deteriorated by moisture or oxygen. Specific materials for the protective layer include metals such as In, Sn, Pb, Au, Cu, Ag, and Al, metal oxides such as MgO, SiO ₂ , and TiO ₂ , polyethylene resin, polyurea resin, and polyimide resin. Resin. For forming the protective layer, a vacuum deposition method, a sputtering method, a plasma polymerization method, a CVD method, a coating method, or the like can be applied.

  The organic electroluminescent elements shown in FIGS. 1 to 4 are manufactured by sequentially forming individual layers on the transparent electrode 2 in accordance with the layer configuration of each organic electroluminescent element. Note that the hole transport layer and / or hole injection layer 3, the light emitting layer 4, the electron transport layer and / or the electron injection layer 5, or the light emitting layer 6 having a charge transporting capability are obtained by subjecting the above materials to vacuum deposition, Or it melt | dissolves or disperses | distributes in a suitable organic solvent, and it forms by the spin coating method, the casting method, the dip method, the inkjet method etc. on the said transparent electrode 1 using the obtained coating liquid. Of these, only the required amount of polymer material can be applied to the desired pixel position, and only a small amount of material is wasted, resulting in being friendly to the global environment, and high-definition patterning. The inkjet method is particularly preferred because it is possible, easy to make a large panel, and has a high degree of freedom for printing.

  The film thicknesses of the hole transport layer and / or hole injection layer 3, the light-emitting layer 4, the electron transport layer and / or the electron injection layer 5, and the light-emitting layer 6 having a charge transport capability are each 10 μm or less, particularly The range of 0.001 to 5 μm is preferable. The dispersion state of each of the above materials (the non-conjugated polymer, the light emitting material, etc.) may be a molecular dispersion state or a fine particle state such as a microcrystal. In the case of a film forming method using a coating solution, it is necessary to select a dispersion solvent in consideration of dispersibility and solubility of each of the above materials in order to obtain a molecular dispersion state. In order to disperse into fine particles, a ball mill, a sand mill, a paint shaker, an attritor, a homogenizer, an ultrasonic method, or the like can be used.

  Finally, in the case of the organic electroluminescent device shown in FIGS. 1 and 2, the back electrode 7 is formed on the electron transport layer and / or the electron injection layer 5 by vacuum deposition, sputtering, or the like. The organic electroluminescent element of the present invention is completed. In the case of the organic electroluminescent element shown in FIG. 3, the back electrode 7 is formed on the light emitting layer 4 and in the case of the organic electroluminescent element shown in FIG. Is formed by a vacuum deposition method, a sputtering method, or the like, thereby completing the organic electroluminescence device of the present invention.

The organic electroluminescent element of the present invention can emit light by applying a direct current voltage of 1 to 200 mA / cm ² at a current density of, for example, 4 to 20 V between a pair of electrodes.

-Image display medium-
An image display medium using the organic electroluminescent element of the present invention will be described.
The organic electroluminescent element of the present invention can be arranged in a matrix shape and / or a segment shape, whereby an image display medium can be formed. In the case where the organic electroluminescent elements are arranged in a matrix, the electrodes may be arranged in a matrix, or both the electrodes and the organic compound layer may be arranged in a matrix. Moreover, when arrange | positioning an organic electroluminescent element in a segment form, the aspect which arrange | positions only an electrode in a segment form may be sufficient, and the aspect which arrange | positions both an electrode and an organic compound layer in a segment form may be sufficient.
The organic compound layer arranged in a matrix or segment can be easily formed by using the ink jet method.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. In Examples, “part” and “%” are based on mass unless otherwise specified.

[Synthesis Example 1 Charge-Transporting Polyurethane (6)]
First, diamine 14 [the following monomer (XII)] was synthesized according to the following synthesis route.

2.0 g of diamine 14 [monomer (XII)] and 30.0 ml of chlorobenzene were placed in a 50 ml three-necked flask and dissolved. Next, a solution of 0.54 g of hexamethylene diisocyanate in chlorobenzene (10 ml) was added dropwise over 30 minutes, and the mixture was heated and stirred at 150 ° C. for 2 hours under a nitrogen stream. After completion of the reaction, the reaction solution was cooled to room temperature, and the reaction solution was dropped into 300 ml of methanol while stirring to precipitate a polymer. The obtained polymer was filtered, washed thoroughly with methanol, and dried. The obtained polymer was dissolved in 30 ml of tetrahydrofuran (THF), and the reprecipitation treatment in which this solution was dropped into 300 ml of methanol was repeated three times to obtain 1.7 g of a charge transporting polyurethane (6). When the molecular weight of this charge transporting polyurethane (6) was measured by gel permeation chromatography (GPC), Mw = 5.68 × 10 ⁴ (in terms of styrene), Mn / Mw = 2.38, The degree of polymerization p determined from the molecular weight was 68.

[Synthesis Example 2 Charge-Transporting Polyurethane (8)]
First, in the synthesis of monomer (XII) in Synthesis Example 1, diamine 18 [the following monomer (XIII)] was prepared in the same manner except that phenyl-9,9-dimethylfluoren-2-ylamine was used instead of diphenylamine. Synthesized.

2.0 g of diamine 18 [monomer (XIII)] and 30.0 ml of chlorobenzene were dissolved in a 50 ml three-necked flask. Next, a solution of 0.52 g of hexamethylene diisocyanate in chlorobenzene (10 ml) was added dropwise over 30 minutes, and the mixture was heated and stirred at 150 ° C. for 2.5 hours under a nitrogen stream. After completion of the reaction, the reaction solution was cooled to room temperature, and the reaction solution was dropped into 300 ml of methanol while stirring to precipitate a polymer. The obtained polymer was filtered, washed thoroughly with methanol, and dried. The obtained polymer was dissolved in 30 ml of THF, and the reprecipitation treatment in which this solution was dropped into 300 ml of methanol was repeated three times to obtain 1.8 g of a charge transporting polyurethane (8). When the molecular weight of this charge transporting polyurethane (8) was measured by GPC, Mw = 9.85 × 10 ⁴ (in terms of styrene) and Mn / Mw = 2.91, and the polymerization degree p determined from the molecular weight of the monomer Was 92.

[Synthesis Example 3 Charge-Transporting Polyurethane (10)]
First, in the synthesis of monomer (XII) in Synthesis Example 1, 1-methylethylenedioxythiophene was used in place of ethylenedioxythiophene, and phenyl-4-thienylphenylamine was used in place of diphenylamine. Thus, diamine 27 [the following monomer (XIV)] was synthesized.

2.0 g of diamine 27 [monomer (XIV)] and 30.0 ml of chlorobenzene were dissolved in a 50 ml three-necked flask. Next, a solution of 0.52 g of hexamethylene diisocyanate in chlorobenzene (10 ml) was added dropwise over 30 minutes, and the mixture was heated and stirred at 150 ° C. for 2.0 hours under a nitrogen stream. After completion of the reaction, the reaction solution was cooled to room temperature, and the reaction solution was dropped into 300 ml of methanol while stirring to precipitate a polymer. The obtained polymer was filtered, washed thoroughly with methanol, and dried. The obtained polymer was dissolved in 30 ml of THF, and the reprecipitation treatment in which this solution was dropped into 300 ml of methanol was repeated three times to obtain 1.8 g of a charge transporting polyurethane (10). When the molecular weight of this charge transporting polyurethane (10) was measured by GPC, Mw = 1.02 × 10 ⁵ (in terms of styrene) and Mn / Mw = 3.05, and the polymerization degree p determined from the molecular weight of the monomer Was 89.

[Synthesis Example 4 Charge-Transporting Polyurethane (84)]
First, in the synthesis of monomer (XII) in Synthesis Example 1, diamine 49 [following monomer (XV) is used except that 2,7-diiodo-9,9-dimethylfluorene is used instead of diiodobenzene. ] Was synthesized.

2.0 g of diamine 49 [monomer (XV)] and 30.0 ml of chlorobenzene were placed in a 50 ml three-necked flask and dissolved. Next, a chlorobenzene (10 ml) solution of 0.50 g of hexamethylene diisocyanate was dropped over 30 minutes, and the mixture was heated and stirred at 150 ° C. for 2.0 hours under a nitrogen stream. After completion of the reaction, the reaction solution was cooled to room temperature, and the reaction solution was dropped into 300 ml of methanol while stirring to precipitate a polymer. The obtained polymer was filtered, washed thoroughly with methanol, and dried. The polymer obtained was dissolved in 30 ml of THF, and the reprecipitation treatment in which this solution was dropped into 300 ml of methanol was repeated three times to obtain 1.7 g of a charge transporting polyurethane (84). When the molecular weight of this charge transporting polyurethane (84) was measured by GPC, Mw = 9.65 × 10 ⁴ (in terms of styrene) and Mn / Mw = 2.54, and the polymerization degree p determined from the molecular weight of the monomer Was 85.

[Synthesis Example 5-Charge transporting polyurethane (52)]
First, diamine 207 [the following monomer (XVI)] was synthesized in the same manner as in the synthesis of monomer (XII) in Synthesis Example 1 except that biphenylphenylamine was used instead of diphenylamine.

2.0 g of diamine 207 [monomer (XVI)] and 30.0 ml of chlorobenzene were dissolved in a 50 ml three-necked flask. Subsequently, a solution of 0.50 g of hexamethylene diisocyanate in chlorobenzene (10 ml) was added dropwise over 30 minutes, and the mixture was heated and stirred at 150 ° C. for 2.5 hours under a nitrogen stream. After completion of the reaction, the reaction solution was cooled to room temperature, and the reaction solution was dropped into 300 ml of methanol while stirring to precipitate a polymer. The obtained polymer was filtered, washed thoroughly with methanol, and dried. The obtained polymer was dissolved in 30 ml of THF, and the reprecipitation treatment in which this solution was dropped into 300 ml of methanol was repeated three times to obtain 1.8 g of a charge transporting polyurethane (52). When the molecular weight of this charge transporting polyurethane (52) was measured by GPC, Mw = 8.96 × 10 ⁴ (in terms of styrene) and Mn / Mw = 2.54, and the polymerization degree p determined from the molecular weight of the monomer Was 91.

  Next, using the charge transporting polyurethane synthesized by the above method, a device was produced as follows.

[Example 1]
A glass substrate on which a 2 mm wide strip-shaped ITO electrode is formed by etching is sequentially washed with neutral detergent, ultrapure water, acetone (for electronics industry, manufactured by Kanto Chemical), and 2-propanol (for electronics industry, manufactured by Kanto Chemical). Washing was performed by applying ultrasonic waves for 5 minutes each, and after drying, a luminescent polymer [the following exemplified compound (XVII), polyfluorene type, Mw≈10 ⁵ ] was prepared as a luminescent material as a 5% chlorobenzene solution. After filtering through a 1 μm polytetrafluoroethylene (PTFE) filter, it was applied by a spin coating method to form a light emitting layer having a thickness of 0.03 μm. Further, after sufficiently drying, as the electron transporting compound, the charge transporting polyurethane (10) synthesized in Synthesis Example 3 above was prepared as a 5% dichloroethane solution, filtered through a 0.1 μm PTFE filter, and then the light emitting layer. An electron transport layer having a thickness of 0.03 μm was formed by applying the film by spin coating. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Example 2]
In the same manner as in Example 1, after washing with ultrasonic waves, a dried 2 mm wide strip-shaped ITO electrode was formed on a glass substrate by etching, and a charge transporting polymer [the above exemplified compound (VIII- 9), polyester-based, Mw≈10 ⁵ ] as a 5% chlorobenzene solution, filtered through a 0.1 μm PTFE filter, and then applied onto the buffer layer by spin coating to form a 0.03 μm thick hole. A transport layer was formed. After sufficiently drying, sublimated and purified Alq3 [Exemplary Compound (IX-1)] as a light-emitting material is put on a tungsten board and evaporated by a vacuum evaporation method, and a film thickness of 0.05 μm is formed on the hole transport layer. A light emitting layer was formed. The degree of vacuum at this time was 10 ⁻⁵ Torr, and the board temperature was 300 ° C. Further, as the electron transporting compound, the charge transporting polyurethane (20) synthesized in Synthesis Example 4 was prepared as a 5% dichloroethane solution, filtered through a 0.1 μm PTFE filter, and then spin coated on the light emitting layer. This was applied to form an electron transport layer having a thickness of 0.03 μm. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Example 3]
As a luminescent material, a luminescent polymer [the above exemplified compound (XVII), polyfluorene-based, Mw≈10 ⁵ ] is prepared as a 5% chlorobenzene solution, filtered through a 0.1 μm PTFE filter, and then applied by spin coating. Then, an organic electroluminescent element was formed in the same manner as in Example 2 except that a 0.03 μm thick light emitting layer was formed.

[Example 4]
The charge transporting polyurethane (6) synthesized in Synthesis Example 1 as a hole transporting compound was prepared as a 5% chlorobenzene solution, filtered through a 0.1 μm PTFE filter, and then applied onto the buffer layer by a spin coating method. An organic electroluminescent element was formed in the same manner as in Example 3 except that a hole transport layer having a thickness of 0.01 μm was formed.

[Example 5]
Charge transport polyurethane (8) synthesized in Synthesis Example 2 as a hole transporting compound on a glass substrate formed by etching a 2 mm wide strip-shaped ITO electrode after ultrasonic cleaning in the same manner as in Example 1. Was prepared as a 5% chlorobenzene solution, filtered through a 0.1 μm PTFE filter, and then applied onto the buffer layer by spin coating to form a 0.01 μm thick hole transport layer. After sufficiently drying, sublimated and purified Alq3 [Exemplary Compound (IX-1)] as a light-emitting material is put on a tungsten board and evaporated by a vacuum evaporation method, and a film thickness of 0.05 μm is formed on the hole transport layer. A light emitting layer was formed. The degree of vacuum at this time was 10 ⁻⁵ Torr, and the board temperature was 300 ° C. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Example 6]
As a luminescent material, a luminescent polymer [the following exemplified compound (XVIII), PPV type, Mw≈10 ⁵ ] is prepared as a 5% chlorobenzene solution, filtered through a 0.1 μm PTFE filter, and then applied by spin coating. Thus, an organic electroluminescent element was formed in the same manner as in Example 5 except that a 0.03 μm thick light emitting layer was formed.

[Example 7]
The charge transport polyurethane of the present invention synthesized in Synthesis Example 5 as a charge transport compound on a glass substrate formed by etching a 2 mm wide strip-shaped ITO electrode after ultrasonic cleaning in the same manner as in Example 1 ( 52) and 0.1 part of a luminescent polymer [Exemplary Compound (XVIII), PPV, Mw≈10 ⁵ ] are mixed to prepare a 10% chlorobenzene solution, and 0.1 μm of PTFE is prepared. After filtering with a filter, it was applied on the buffer layer by spin coating to form a light emitting layer having a thickness of 0.05 μm and a charge transporting ability. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

Example 8
A glass substrate on which a 2 mm wide strip-shaped ITO electrode is formed by etching is sequentially washed with neutral detergent, ultrapure water, acetone (for electronics industry, manufactured by Kanto Chemical), and 2-propanol (for electronics industry, manufactured by Kanto Chemical). Washing was performed by applying ultrasonic waves for 5 minutes each, and after drying, a luminescent polymer [Exemplary Compound (XVIII), PPV system, Mw≈10 ⁵ ] was prepared as a luminescent material as a 5% chlorobenzene solution, 0.1 μm After filtering with a polytetrafluoroethylene (PTFE) filter, it was applied by an ink jet printing method to form a light emitting layer having a thickness of 0.03 μm. Further, after sufficiently drying, as the electron transporting compound, the charge transporting polyurethane (20) synthesized in Synthesis Example 4 was prepared as a 5% dichloroethane solution, filtered through a 0.1 μm PTFE filter, and then the light emitting layer. An electron transport layer having a film thickness of 0.03 μm was formed on the top by an ink-jet printing method. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Comparative Example 1]
A glass substrate on which a 2 mm wide strip-shaped ITO electrode is formed by etching is sequentially washed with neutral detergent, ultrapure water, acetone (for electronics industry, manufactured by Kanto Chemical), and 2-propanol (for electronics industry, manufactured by Kanto Chemical). Washing was performed by applying ultrasonic waves for 5 minutes each, and after drying, a luminescent polymer [Exemplary Compound (XVII), polyfluorene-based, Mw≈10 ⁵ ] was prepared as a luminescent material as a 5% chlorobenzene solution. After filtering through a 1 μm polytetrafluoroethylene (PTFE) filter, it was applied by a spin coating method to form a light emitting layer having a thickness of 0.03 μm. Further, after sufficiently drying, an electron transporting layer having a thickness of 0.05 μm composed of the exemplified compound (VII-1) was formed as an electron transporting compound by a vacuum deposition method. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic EL element was 0.04 cm ² .

[Comparative Example 2]
It is comprised from the said exemplary compound (VIII-2) as a hole transportable compound on the glass substrate which formed the 2 mm width strip-shaped ITO electrode by etching similarly to the comparative example 1, and was dried. A 0.065 μm-thick luminescent layer composed of Alq3 [substantially exemplified compound (IX-1)] obtained by sublimation-purifying a 0.05 μm-thick hole transport layer as a luminescent material is exemplified as an electron-transporting compound. An electron transport layer having a thickness of 0.05 μm composed of the compound (VII-1) was sequentially formed by a vacuum deposition method. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Comparative Example 3]
It is comprised from the said exemplary compound (VIII-2) as a hole transportable compound on the glass substrate which formed the 2 mm width strip-shaped ITO electrode by etching similarly to the comparative example 1, and was dried. A hole transport layer having a thickness of 0.05 μm is formed by a vacuum deposition method, and a light-emitting polymer (the exemplified compound (XVIII), PPV system, Mw≈10 ⁵ ) is prepared as a light-emitting material as a 5% chlorobenzene solution, After filtering with a 0.1 μm PTFE filter, it is applied by spin coating and sufficiently dried to form a 0.03 μm thick light-emitting layer, and further composed of the exemplified compound (VII-1) as an electron transporting compound An electron transport layer having a thickness of 0.05 μm was formed by vacuum deposition. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Comparative Example 4]
It is comprised from the said exemplary compound (VIII-2) as a hole transportable compound on the glass substrate which formed the 2 mm width strip-shaped ITO electrode by etching similarly to the comparative example 1, and was dried. A light emitting layer having a thickness of 0.065 μm composed of Alq3 [the exemplified compound (IX-1)] obtained by sublimation-purifying a 0.05 μm thick hole transport layer as a light emitting material was sequentially formed by a vacuum deposition method. . Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Comparative Example 5]
It is comprised from the said exemplary compound (VIII-2) as a hole transportable compound on the glass substrate which formed the 2 mm width strip-shaped ITO electrode by etching similarly to the comparative example 1, and was dried. A hole transport layer having a thickness of 0.05 μm was formed by vacuum deposition. Subsequently, a luminescent polymer [Exemplary Compound (XVIII), PPV, Mw≈10 ⁵ ] as a luminescent material was prepared as a 5% chlorobenzene solution, filtered through a 0.1 μm PTFE filter, and then spin-coated. This was applied and sufficiently dried to form a light emitting layer having a thickness of 0.03 μm. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

[Comparative Example 6]
In the same manner as in Comparative Example 1, after ultrasonic cleaning, on a glass substrate on which a dried 2 mm wide strip-shaped ITO electrode was formed by etching, 1 part of the exemplified compound (VIII-2) as a hole transporting compound, 1 part of Alq3 [substantially exemplified compound (IX-1)] purified by sublimation as a luminescent material and 1 part of polymethyl methacrylate (PMMA) as a binder resin were mixed to prepare a 10% dichloroethane solution. It filtered with the PTFE filter and apply | coated by the dip method, and the light emitting layer which has a 0.05-micrometer-thick charge transport ability was formed. Finally, a Mg—Ag alloy was deposited by co-evaporation to form a back electrode having a width of 2 mm and a thickness of 0.15 μm so as to cross the ITO electrode. The effective area of the formed organic electroluminescent element was 0.04 cm ² .

(Evaluation)
The organic electroluminescent device produced as described above was applied with a DC voltage in vacuum [133.3 × 10 ⁻³ Pa (10 ⁻⁵ Torr)] with the ITO electrode side plus and the Mg—Ag side minus. The emission was measured, and the rising voltage, maximum luminance, and driving current density at the maximum luminance were evaluated. The measurement results are shown in the following table.
Moreover, the light emission lifetime of the organic electroluminescent element was evaluated in dry nitrogen. In the measurement of the light emission lifetime, the current value was set so that the initial luminance was 50 cd / cm ^2, and the time until the luminance was halved from the initial value by low current driving was defined as the element lifetime (Hour). The device lifetime at this time is also shown in the following table.

  From the results shown in the above table, the charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) of the present invention as a partial structure, It has an ionization potential and charge mobility suitable for an organic electroluminescence device, and a good thin film can be formed using a spin coating method, a dip method, an ink jet method, or the like. Further, since the charge injection property and the transport property are improved, the charge balance is improved, and stable and high luminance and high efficiency characteristics are exhibited. Therefore, the organic electroluminescent element of the present invention is free from defects such as pinholes, can be easily increased in area, and has excellent durability and light emitting characteristics.

It is typical sectional drawing which shows an example of the laminated constitution of the organic electroluminescent element of this invention. It is typical sectional drawing which shows an example of the laminated constitution of the organic electroluminescent element of this invention. It is typical sectional drawing which shows an example of the laminated constitution of the organic electroluminescent element of this invention. It is typical sectional drawing which shows an example of the laminated constitution of the organic electroluminescent element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent insulator board | substrate 2 Transparent electrode 3 Hole transport layer and / or hole injection layer 4 Light emitting layer 5 Electron transport layer and / or electron injection layer 6 Light emitting layer with charge transport ability 7 Back electrode

Claims (12)

At least one of the organic compound layers is formed between a pair of electrodes composed of an anode and a cathode, each of which is transparent or translucent, and at least one of the organic compound layers has the following general formula (I-1) and An organic electroluminescent device comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the structure represented by (I-2) as a partial structure.

[In the general formulas (I-1) and (I-2), Ar ¹ represents a substituted or unsubstituted monovalent phenyl group, a substituted or unsubstituted monovalent polynuclear aromatic carbon atom having 2 to 10 aromatic rings. Represents hydrogen, a substituted or unsubstituted monovalent condensed aromatic hydrocarbon having 2 to 10 aromatic rings or a substituted or unsubstituted monovalent aromatic heterocyclic ring, and X ¹ is represented by the following general formula (II): Represents a group. ]

[In the general formula (II), Ar ² represents a substituted or unsubstituted divalent phenylene group, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted aromatic Represents a divalent condensed aromatic hydrocarbon having 2 to 10 rings or a substituted or unsubstituted divalent aromatic heterocyclic ring, X ² represents a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, n represents an integer of 1 to 10. ]   The organic compound layer includes at least a light emitting layer and an electron transport layer, and at least one of the light emitting layer and the electron transport layer is selected from the structures represented by the general formulas (I-1) and (I-2) The organic electroluminescent element according to claim 1, comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the above as a partial structure.   The organic electroluminescent element according to claim 2, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane.   The organic compound layer has at least a hole transport layer, a light emitting layer, and an electron transport layer, and at least one of the hole transport layer, the light emitting layer, and the electron transport layer has the general formula (I-1). The organic electroluminescent device according to claim 1, comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by (I) and (I-2) as a partial structure.   The organic electroluminescent element according to claim 4, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane.   The organic compound layer has at least a hole transport layer and a light emitting layer, and at least one of the hole transport layer and the light emitting layer is a structure represented by the general formulas (I-1) and (I-2). The organic electroluminescent element according to claim 1, comprising a charge transporting polyurethane having a repeating unit containing at least one selected from the group consisting of:   The organic light emitting device according to claim 6, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane.   The organic compound layer is composed only of a light emitting layer having a charge transporting ability, and the light emitting layer has at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure. 2. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device comprises a charge transporting polyurethane having a repeating unit, and a buffer layer between the light emitting layer having the charge transporting capability and the anode. .   9. The organic electroluminescent element according to claim 8, wherein the light emitting layer contains a charge transporting material other than the charge transporting polyurethane. The charge transporting polyurethane having a repeating unit containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure is represented by the following general formula (III-1) or (III The organic electroluminescent device according to any one of claims 1 to 9, wherein the organic electroluminescent device is a charge transporting polyurethane represented by -2).

[In General Formulas (III-1) and (III-2), A represents at least one selected from the structures represented by General Formulas (I-1) and (I-2); Represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, and T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or carbon Represents a divalent branched hydrocarbon group of 2 to 10, Y and Z each represents a substituted or unsubstituted divalent alkylene group or a substituted or unsubstituted divalent aromatic group; , 0 or 1, and p represents an integer of 5 to 5,000. ] The organic electroluminescent element according to any one of claims 1 to 10, wherein one or more organic compound layers are provided between a pair of electrodes composed of an anode and a cathode, at least one of which is transparent or translucent. A method for producing an organic electroluminescent device comprising:
The manufacturing method of the organic electroluminescent element characterized by having the application | coating process which apply | coats the application | coating solution which dissolved the component of the said organic compound layer in the solvent by inkjet printing.   An image display medium, wherein the organic electroluminescence device according to claim 1 is arranged in at least one of a matrix shape and a segment shape.

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