JP5966422B2 - Polymer, organic electroluminescent element material, composition for organic electroluminescent element, organic electroluminescent element, organic EL display device, and organic EL lighting - Google Patents

Description

  The present invention relates to a polymer, and in particular, a polymer useful as a hole injection layer and a hole transport layer of an organic electroluminescence device, an organic electroluminescence device material containing the polymer, a composition for an organic electroluminescence device, and an organic material. The present invention relates to an electroluminescent element, and an organic EL display and an organic EL illumination having the organic electroluminescent element.

  Examples of the method for forming the organic layer in the organic electroluminescence device include a vacuum deposition method and a wet film formation method. Since the vacuum deposition method is easy to stack, it has an advantage that the charge injection from the anode and / or the cathode is improved, and the exciton light-emitting layer is easily contained. On the other hand, the wet film formation method does not require a vacuum process, is easy to increase in area, and can be easily applied to a plurality of materials having various functions by using a coating liquid in which a plurality of materials having various functions are mixed. There is an advantage that a layer containing these materials can be formed.

However, since the wet film forming method is difficult to stack, the driving stability is inferior to that of the element by the vacuum vapor deposition method, and the present state is that it has not reached a practical level except for a part.
Therefore, in order to perform lamination by a wet film forming method, a polymer having a crosslinkable group has been developed. For example, Patent Documents 1 to 3 disclose organic electroluminescent elements that contain a specific polymer and are stacked by a wet film forming method.
However, these devices have a problem that the drive voltage is high and the light emission efficiency is low.

JP-T-2004-505169 Special table 2007-514654 gazette JP 2008-150516 A

An object of the present invention is to provide a polymer having a high hole injecting and transporting ability and a composition for an organic electroluminescent device containing the polymer.
Another object of the present invention is to provide an organic electroluminescent element having a low driving voltage, a high-quality organic EL display device, and organic EL illumination.

As a result of intensive studies, the present inventors have found that the above problems can be solved by using a polymer containing a specific repeating unit, and have completed the present invention.
That is, the present invention is at least a repeat represented by the following formulas (I-1), (I-2), (I-3), (II-1), (II-2) and (II-3). It exists in the polymer containing a unit, organic electroluminescent element material, the composition for organic electroluminescent elements, an organic electroluminescent element, an organic electroluminescence display, and organic electroluminescent illumination.

(In the above formula, R ¹ represents a group containing a crosslinkable group selected from the following crosslinkable group group T. R ² and R ³ are different from each other and have a hydrogen atom or a substituent. An alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aromatic hydrocarbon ring group which may have a substituent, or an aromatic heterocyclic group which may have a substituent .
<Crosslinkable group T>

(In the formula, R ^{21 to} R ²³ each independently represents a hydrogen atom or an alkyl group which may have a substituent. Ar ²¹ represents an aromatic hydrocarbon ring which may have a substituent. An aromatic heterocyclic group which may have a group or a substituent, and the benzocyclobutene ring may have a substituent))

The polymer of the present invention has a high hole injecting and transporting ability. Therefore, an element formed using the polymer of the present invention has a low driving voltage.
Further, since the polymer of the present invention is excellent in electrochemical stability, an element including a layer formed using the polymer is a flat panel display (for example, for OA computers or wall-mounted televisions), an in-vehicle display element. It can be applied to light sources (for example, light sources for copiers, backlight sources for liquid crystal displays and instruments), display boards, and indicator lamps that make use of the characteristics of cell phone displays and surface light emitters. Is a big one.

It is sectional drawing which shows typically an example of the structure of the organic electroluminescent element of this invention.

Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention does not exceed the gist thereof. Not specified in the content of [Polymer]
The present invention is a compound comprising repeating units represented by the following formulas (I-1), (I-2), (I-3), (II-1), (II-2) and (II-3). It is a coalescence.

(In the above formula, R ¹ represents a group containing a crosslinkable group selected from the following crosslinkable group group T. R ² and R ³ are different from each other and have a hydrogen atom or a substituent. Or an aromatic hydrocarbon ring group which may have a substituent, or an aromatic heterocyclic group which may have a substituent.
<Crosslinkable group T>

(In the formula, R ^{21 to} R ²³ each independently represents a hydrogen atom or an alkyl group which may have a substituent. Ar ²¹ represents an aromatic hydrocarbon ring which may have a substituent. An aromatic heterocyclic group which may have a group or a substituent, and the benzocyclobutene ring may have a substituent))
Here, in the formulas (II-1), (II-2), and (II-3), the polymer is represented by the following formulas (IV-1), (IV-2), and (IV-3). It is preferable.

(Note that R ¹ , R ² and R ^{3 have the same} meanings as in formulas ( II- 1), ( II- 2) and ( II- 3).)
Further, in the formulas (II-1), (II-2) and (II-3), it is a polymer represented by the following formulas (III-1), (III-2) and (III-3). It is preferable.

(Note that, for R ¹ , R ² and R ³ , the formulas (II-1), (II-2) and (II-3)
It is synonymous with. )
The above (IV-1), (IV-2), (IV-3), (III-1), (III-2) and (III-3) are used in that a high molecular weight polymer is obtained. It is preferable.
In addition, the repeating unit selected from the formulas (I-1), (I-2) and (I-3), and the formulas (II-1), (II- The repeating unit selected from 2) and (II-3) is preferably a polymer in which the repeating units are alternately arranged.

Furthermore, in terms of improved solubility, a repeating unit selected from the formulas (I-1), (I-2) and (I-3), and the formulas (II-1), (II-2) and ( It is preferable that the repeating unit selected from II-3) is a polymer that is randomly arranged.
A repeating unit selected from the formulas (I-1), (I-2) and (I-3) and a repeating unit selected from the formulas (II-1), (II-2) and (II-3) The ratio is preferably 2: 1 to 1: 2. More preferably, it is 1.5: 1 to 1: 1.5. The presence of repeating units at such a ratio improves durability and improves solubility.

(About R ¹ )
R ¹ represents a group containing a crosslinkable group selected from the following crosslinkable group group T.
<Crosslinkable group T>

(In the formula, R ^{21 to} R ²³ each independently represents a hydrogen atom or an alkyl group which may have a substituent. Ar ²¹ represents an aromatic ring group which may have a substituent. Show.
The benzocyclobutene ring may have a substituent, or the substituents may be bonded to each other to form a ring. )
The crosslinkable group is preferably a group that crosslinks by cationic polymerization. This is because the reactivity is high and the solubility in a solvent can be easily reduced. Examples thereof include cyclic ether groups such as epoxy groups and oxetane groups, and vinyl ether groups. Among these, an oxetane group is particularly preferable in terms of easy control of the rate of cationic polymerization. A vinyl ether group in which a vinyl group is bonded via an oxygen atom is particularly preferable in that a hydroxyl group that may cause deterioration of the device during cationic polymerization is hardly generated.

In addition, an arylvinylcarbonyl group such as a cinnamoyl group and a group that undergoes a cycloaddition reaction such as a group derived from a benzocyclobutene ring are preferable in terms of further improving electrochemical stability.
As the crosslinkable group, a group represented by the following formula is particularly preferable from the viewpoint of excellent electrochemical stability.

(The benzocyclobutene ring in the above formula may have a substituent. The substituents may be bonded to each other to form a ring.)
R ¹ may be a crosslinkable group itself selected from the following crosslinkable group group T, or may be one in which an appropriate divalent group is bonded to the crosslinkable group. As the divalent group, a group selected from the group consisting of an —O— group, a —C (═O) — group or a —CH ₂ — group which may have a substituent, can be arbitrarily combined and ratiod. And the bivalent group formed by connecting 1-30 in order is preferable.
It illustrates preferred examples of R ^1, but the present invention is not limited to the following examples thereof.

(About R ² and R ³ )
R ² and R ³ are different from each other and are each a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aromatic carbon which may have a substituent. A hydrogen ring group or an aromatic heterocyclic group which may have a substituent is shown.
From the viewpoint of hole injection / transport properties, R ² is preferably a hydrogen atom.

From the viewpoint of solubility before the crosslinking reaction, either one of R ² and R ³ is preferably an alkyl group or an alkoxy group.
From the viewpoint of electrochemical durability, any one of R ² and R ³ is preferably an alkyl group or an aromatic hydrocarbon ring group.
From the above viewpoints, it is particularly preferable that R ² is a hydrogen atom and R ³ is an alkyl group.

  Examples of the alkyl group which may have a substituent include a linear, branched, or cyclic alkyl group having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less. For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group, dodecyl group, etc. . An alkyl group having 3 to 8 carbon atoms is preferable from the viewpoint of not decreasing the hole injecting and transporting property and increasing the solubility.

Examples of the alkoxy group which may have a substituent include linear, branched, or cyclic alkyl groups having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less. For example, methoxy group, ethoxy group, tert-butoxy group, n-pentoxy group, cyclohexoxy group and the like . That do not reduce the positive hole injection transport, from the viewpoint of enhancing the solubility, preferably an alkyl group having 3 to 8 carbon atoms.

Examples of the aromatic hydrocarbon ring group which may have a substituent include monovalent or higher-valent groups of 6-membered monocyclic rings or 2-5 condensed rings. Examples thereof include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring and the like.
Examples of the aromatic heterocyclic group which may have a substituent include a monovalent or higher-valent group of a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. For example, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, Thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinoline ring Quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring and the like.

Examples of the aromatic heterocyclic group which may have a substituent include a monovalent or higher-valent group of a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. For example, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, Thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinoline ring Quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring and the like.
The substituent that the alkyl group, alkoxy group, aromatic hydrocarbon ring group, and aromatic heterocyclic group may have is not particularly limited, and examples thereof include groups selected from the following substituent group Z. An alkyl group, an alkoxy group, an aromatic hydrocarbon ring group, and an aromatic heterocyclic group are preferable.

(Substituent group Z)
For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group, dodecyl group, etc. A linear, branched or cyclic alkyl group having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less;
An alkenyl group having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a vinyl group;
An alkynyl group such as an ethynyl group, which usually has 2 or more carbon atoms and is usually 24 or less, preferably 12 or less;
For example, an alkoxy group having a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, such as a methoxy group or an ethoxy group;

For example, an aryloxy group having usually 4 or more, preferably 5 or more, usually 36 or less, preferably 24, such as a phenoxy group, a naphthoxy group, or a pyridyloxy group;
For example, an alkoxycarbonyl group having 2 or more carbon atoms, usually 24 or less, preferably 12 or less, such as a methoxycarbonyl group or an ethoxycarbonyl group;
For example, a dialkylamino group having 2 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a dimethylamino group or a diethylamino group;
For example, a diarylamino group having a carbon number of usually 10 or more, preferably 12 or more, usually 36 or less, preferably 24 or less, such as a diphenylamino group, a ditolylamino group, or an N-carbazolyl group;

An arylalkylamino group having usually 7 carbon atoms, usually 36 or less, preferably 24 or less, such as a phenylmethylamino group;
For example, an acetyl group, a benzoyl group, etc., an acyl group having usually 2 carbon atoms and usually having 24 or less, preferably 12;
For example, a halogen atom such as a fluorine atom or a chlorine atom;
A haloalkyl group having usually 1 or more and usually 12 or less, preferably 6 or less, such as a trifluoromethyl group;
For example, an alkylthio group having a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, such as a methylthio group or an ethylthio group;

For example, an arylthio group having a carbon number of usually 4 or more, preferably 5 or more, usually 36 or less, preferably 24 or less, such as a phenylthio group, a naphthylthio group, or a pyridylthio group;
For example, a silyl group having a carbon number of usually 2 or more, preferably 3 or more, usually 36 or less, preferably 24 or less, such as a trimethylsilyl group or a triphenylsilyl group;
For example, a siloxy group having 2 or more, preferably 3 or more, usually 36 or less, preferably 24 or less, such as trimethylsiloxy group or triphenylsiloxy group;
A cyano group;
For example, an aromatic hydrocarbon ring group having usually 6 or more carbon atoms and usually 36 or less, preferably 24 or less, such as a phenyl group or a naphthyl group;
For example, an aromatic heterocyclic group having 3 or more, preferably 4 or more, usually 36 or less, preferably 24 or less, such as thienyl group or pyridyl group.

Among these substituents, an alkyl group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms are preferable from the viewpoint of solubility.
In addition, each of the above substituents may further have a substituent, and examples thereof include the groups exemplified in the above section (Substituent Group Z).
The formula weight of the substituents for R ² and R ³ is preferably 200 or less, more preferably 100 or less, including further substituted substituents.

Within the above range, the number of nitrogen atoms per unit molecular weight in the polymer increases, and therefore the hole injection / transport capability of the polymer is good, which is preferable.
R ² and R ³ represent an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aromatic hydrocarbon ring group which may have a substituent, or a substituent. When it is an aromatic heterocyclic group which may be present, there may be a plurality of R ² and R ^{3 s,} and when there are a plurality, they may be the same or different. R ² and R ³ are preferably one or two, and more preferably one.

(Ratio of the cross-linking groups ^{R 1)}
When the number of crosslinkable groups possessed by the polymer of the present invention is expressed by the number per 1000 molecular weight, it is usually 3.0 or less, preferably 2.0 or less, more preferably 1.5 or less per 1000 molecular weight. Also, it is usually 0.05 or more, preferably 0.1 or more.
Within the above range, it is difficult to form a flat film due to cracks, and there are few unreacted crosslinkable groups remaining in the film after crosslinking, which hardly affects the drive life of the resulting device.

Furthermore, the film after cross-linking is preferable in that the solubility in a solvent is sufficiently lowered and a multilayer laminated structure can be easily formed by wet film formation.
Here, the number of crosslinkable groups per 1000 molecular weight of the polymer is calculated from the molar ratio of charged monomers at the time of synthesis and the structural formula, excluding the terminal groups from the polymer.
For example, the case of the polymer 1 synthesized in Synthesis Example 1 described later will be described.

In polymer 1, the molecular weight of the repeating unit excluding the terminal group is 254.51 on average, and the average number of crosslinkable groups is 0.1527 per repeating unit. When this is calculated by a simple proportion, the number of crosslinkable groups per 1000 molecular weight is calculated as 0.6.
In the polymer of the present invention, the repeating units represented by the formulas (I-1), (I-2), (I-3), (II-1), (II-2) and (II-3) Preferred specific examples are shown below, but the present invention is not limited thereto.
<Specific Example of Repeating Unit Represented by Formula (I-1)>

  <Specific Example of Repeating Unit Represented by Formula (I-2) or (I-3)>

  <Specific Example of Repeating Unit Represented by Formula (II-1)>

  <Specific Example of Repeating Unit Represented by Formula (II-2) or (II-3)>

Although the preferable specific example of the polymer of this invention is shown below, this invention is not limited to these.
<Specific examples of polymer>

[Reason why the polymer of the present invention is effective]
By using the polymer of the present invention, the solubility before cross-linking is high, the cross-linking is insolubilized, lamination is possible, the hole injection / transport capability is high, and the driving voltage of the resulting device is low. The reason is estimated as follows.
The polymer of the present invention comprises repeating units represented by formulas (I-1), (I-2), (I-3), (II-1), (II-2) and (II-3). Since it contains, it has at least 6 or more types of triphenylamine structures. Since the same skeleton called a triphenylamine structure is continuous and only the substituents and the mode of connection are different, it is considered that the solubility before crosslinking is high. In addition, since the polymer of the present invention has a continuous triphenylamine structure, which is the simplest structure among triarylamines having a hole injection / transport capability, It is presumed that the hole transportability is excellent.
As mentioned above, the organic electroluminescent element containing the layer formed using the polymer of this invention has a low drive voltage.

[Molecular weight range]
The weight average molecular weight (Mw) of the polymer of the present invention is usually 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, further preferably 200,000 or less, Usually, it is 1,000 or more, preferably 2,500 or more, more preferably 5,000 or more, and further preferably 20,000 or more.

Within the above range, the solubility of the polymer in the organic solvent and the film formability are good.
The number average molecular weight (Mn) is usually 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, and further preferably 2,000,000 or less, and usually 15 20,000 or more, preferably 20,000 or more.
Within the above range, the solubility of the polymer in the organic solvent and the film formability are good. Moreover, since the glass transition temperature, melting | fusing point, and vaporization temperature are favorable, it is preferable at the point which heat resistance is enough.

Further, the degree of dispersion of the polymer of the present invention (Mw / Mn: Mw represents a weight average molecular weight and Mn represents a number average molecular weight) is usually 2.4 or less, preferably 2.0 or less. The lower limit is 1.0 or more.
Within the above range, purification is easy, and solubility in an organic solvent and charge transportability are good, which is preferable.

Below, the measuring method of a weight average molecular weight and a number average molecular weight is shown.
The weight average molecular weight is determined by SEC (size exclusion chromatography) measurement.
Here, SEC measurement conditions are shown.
The column is TSKgel (manufactured by Tosoh Corp.) GMHXL × 2 or those exhibiting a resolution equal to or higher than that,
Particle size: 9mm
Column size: 7.8 mm inner diameter x 30 cm length x 2
Guaranteed theoretical plate number: about 14000TP / 30cm
The column temperature is 40 ° C.

The moving bed is selected from tetrahydrofuran and chloroform that do not adsorb to the filler, and the flow rate is 1.0 ml / min. The injection concentration is 0.1% by weight, and the injection amount is 0.10 ml. As a detector, UV / Vis (SPD-20AV, manufactured by Shimadzu Corporation) is used.
In SEC measurement, the elution time is shorter for higher molecular weight components and the elution time is longer for lower molecular weight components, but using the calibration curve calculated from the elution time of polystyrene (standard sample) with a known molecular weight, the elution time of the sample is changed to the molecular weight. The molecular weight distribution is determined by conversion, and the number average molecular weight is calculated therefrom.
The measuring device is not particularly limited as long as the same measurement as described above is possible, and other measuring devices may be used, but the above measuring device is preferably used.

[Physical properties]
The polymer of the present invention is preferably higher in solubility in an organic solvent in that a film can be formed uniformly.
The ionization potential of the polymer of the present invention is usually 4.50 to 5.70 eV, preferably 4.90 to 5.50 eV, and more preferably 5.00 to 5.40 eV. Within the above range, holes are easily generated and the hole injection property from the electrode is excellent, which is preferable in terms of low driving voltage when used as an element.

[Synthesis method]
The polymer of the present invention can be synthesized by selecting a raw material according to the structure of the target polymer and using a known method.
The method for polymerizing the polymer of the present invention is not particularly limited, and is arbitrary as long as the polymer of the present invention is obtained. For example, it can be produced by a polymerization method using the Ullmann reaction, a polymerization method using a Buchwald-Hartwig reaction, or the like using the above monomers.
In the case of the polymerization method by the Ullmann reaction and the polymerization method by the Buchwald-Hartwig reaction, for example, the polymer of the present invention is synthesized by reacting an aniline derivative, dihalogenated benzene, and dihalogenated biphenyl.

  In the above polymerization method, the reaction for forming an N-aryl bond is usually performed in the presence of a base such as potassium carbonate, tert-butoxy sodium, triethylamine or the like. Moreover, it can also carry out in presence of transition metal catalysts, such as copper and a palladium complex, for example.

<Organic electroluminescent material>
The polymer of the present invention is preferably used as an organic electroluminescent element material. That is, the organic electroluminescent element material made of the polymer of the present invention is preferable.
When used as an organic electroluminescent device material, it is preferably used as a material for forming a hole injection layer and / or a hole transport layer in an organic electroluminescent device, that is, a charge transport material. Moreover, since an organic electroluminescent element can be manufactured easily, it is preferable to use the polymer of this invention for the organic layer formed by a wet film-forming method.

<Composition for organic electroluminescence device>
The composition for organic electroluminescent elements of the present invention is a composition comprising the arylamine polymer of the present invention and a solvent.
The composition for organic electroluminescent elements of the present invention is generally used as a coating solution for forming an organic layer by a wet film-forming method in an organic electroluminescent element having an organic layer disposed between an anode and a cathode. It is done. It is preferable that the composition for organic electroluminescent elements of the present invention is used for forming a hole transport layer in the organic layer.

Here, when there is one layer between the anode and the light emitting layer in the organic electroluminescent element, this is referred to as a “hole transport layer”, and when there are two or more layers, the layer in contact with the anode is The “hole injection layer” and the other layers are collectively referred to as “hole transport layer”. In addition, layers provided between the anode and the light emitting layer may be collectively referred to as a “hole injection / transport layer”.
Although the composition for organic electroluminescent elements of the present invention is characterized by containing the arylamine polymer of the present invention, it usually further contains a solvent.
The solvent preferably dissolves the arylamine polymer of the present invention, and usually dissolves the polymer compound at room temperature at 0.05% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more. It is a solvent.

In addition, the composition for organic electroluminescent elements of this invention may contain only 1 type of the arylamine polymer of this invention, and may contain 2 or more types.
In the composition for organic electroluminescence device of the present invention, the arylamine polymer of the present invention is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, and usually 50%. It is contained in an amount of not more than wt%, preferably not more than 20 wt%, more preferably not more than 10 wt%.

Moreover, the said composition may contain additives, such as various additives. In this case, as the solvent, a solvent that dissolves both the arylamine polymer of the present invention and the additive by 0.05% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more is used. Is preferred.
The additive for promoting the crosslinking reaction of the arylamine polymer of the present invention contained in the composition for an organic electroluminescent device of the present invention includes an alkylphenone compound, an acylphosphine oxide compound, a metallocene compound, an oxime ester compound, an azo compound, Examples thereof include polymerization initiators such as onium salts and polymerization accelerators, photosensitizers such as condensed polycyclic hydrocarbons, porphyrin compounds, and diaryl ketone compounds. These may be used alone or in combination of two or more.

When the composition for organic electroluminescent elements of the present invention is used to form a hole injection layer, it is preferable to further contain an electron-accepting compound from the viewpoint of reducing the resistance value of the formed layer.
As the electron-accepting compound, a compound having an oxidizing power and an ability to accept one electron from the above-described hole-transporting compound is preferable. Specifically, a compound with an electron affinity of 4 eV or more is preferable, and a compound with a compound of 5 eV or more is more preferable.

  Examples of the electron-accepting compound include onium salts substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, iron (III) chloride (Japanese Patent Laid-Open No. 11-251067). Publication), high valence inorganic compounds such as ammonium peroxodisulfate, cyano compounds such as tetracyanoethylene, aromatic boron compounds such as tris (pentafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-31365), fullerene derivatives, iodine Etc.

Of the above-mentioned compounds, an onium salt substituted with an organic group, a high-valence inorganic compound, and the like are preferable because they have strong oxidizing power. In addition, an onium salt substituted with an organic group, a cyano compound, an aromatic boron compound, or the like is preferable because it is highly soluble in various solvents and can be applied to form a film by a wet film formation method.
Specific examples of onium salts substituted with organic groups, cyano compounds, and aromatic boron compounds suitable as electron-accepting compounds include those described in WO 2005/089024, and preferred examples thereof are also the same. is there. Examples thereof include compounds represented by the following structural formulas, but are not limited thereto.

In addition, an electron-accepting compound may be used individually by 1 type, and may use 2 or more types by arbitrary combinations and a ratio.
The solvent contained in the composition for organic electroluminescent elements of the present invention is not particularly limited, but is preferably toluene, xylene, methicylene because it is necessary to dissolve the arylamine polymer of the present invention. Aromatic compounds such as cyclohexylbenzene; halogen-containing solvents such as 1,2-dichloroethane, chlorobenzene, o-dichlorobenzene; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA), etc. Aliphatic ether, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethyl Ether solvents such as aromatic ethers such as nisol; aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate and n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, benzoic acid Examples thereof include organic solvents such as ester solvents such as isopropyl, propyl benzoate, and n-butyl benzoate. These may be used alone or in combination of two or more.

The concentration of the solvent contained in the composition for organic electroluminescent elements of the present invention is usually 10% by weight or more, preferably 50% by weight or more, more preferably 80% by weight or more.
In addition, it is widely known that moisture may promote deterioration of the performance of the organic electroluminescent element, particularly brightness reduction during continuous driving, in order to reduce moisture remaining in the coating film as much as possible. Among these solvents, those having a water solubility at 25 ° C. of 1% by weight or less are preferred, and solvents having a solubility of 0.1% by weight or less are more preferred.

Examples of the solvent contained in the composition for organic electroluminescent elements of the present invention include a solvent having a surface tension at 20 ° C. of less than 40 dyn / cm, preferably 36 dyn / cm or less, more preferably 33 dyn / cm or less.
That is, when the crosslinked layer in the present invention is formed by a wet film forming method, the affinity with the base is important. The uniformity of the film quality greatly affects the uniformity and stability of the light emission of the organic electroluminescence device. Low tension is required. By using such a solvent, the crosslinked layer in the present invention can be formed uniformly.

  Specific examples of such a low surface tension solvent include the aforementioned aromatic solvents such as toluene, xylene, methicylene and cyclohexylbenzene, ester solvents such as ethyl benzoate, ether solvents such as anisole, trifluoromethoxy, and the like. Anisole, pentafluoromethoxybenzene, 3- (trifluoromethyl) anisole, ethyl (pentafluorobenzoate) and the like can be mentioned.

The concentration of these solvents in the composition is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more.
Examples of the solvent contained in the composition for organic electroluminescence device of the present invention include a solvent having a vapor pressure at 25 ° C. of 10 mmHg or less, preferably 5 mmHg or less and usually 0.1 mmHg or more. By using such a solvent, it is possible to prepare a composition suitable for a process for producing an organic electroluminescent device by a wet film-forming method and suitable for the properties of the arylamine polymer of the present invention. Specific examples of such a solvent include the above-described aromatic solvents such as toluene, xylene, and methicylene, ether solvents, and ester solvents. The concentration of these solvents in the composition is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more.

  As a solvent contained in the composition for organic electroluminescent elements of the present invention, the vapor pressure at 25 ° C. is 2 mmHg or more, preferably 3 mmHg or more, more preferably 4 mmHg or more (however, the upper limit is preferably 10 mmHg or less). A mixed solvent of a solvent and a solvent having a vapor pressure at 25 ° C. of less than 2 mmHg, preferably 1 mmHg or less, more preferably 0.5 mmHg or less. By using such a mixed solvent, a homogeneous layer containing the arylamine polymer of the present invention and further an electron accepting compound can be formed by a wet film forming method. The concentration of the mixed solvent in the composition is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more.

  Since the organic electroluminescent element is formed by laminating a large number of layers made of an organic compound, it is very important that the film quality is uniform. When a layer is formed by a wet film forming method, a film forming method such as a coating method such as a spin coating method or a spray method, or a printing method such as an ink jet method or a screen method can be adopted depending on the material and properties of the base. For example, since the spray method is effective for forming a uniform film on a surface with unevenness, it is preferable when a layer made of an organic compound is provided on a surface where unevenness due to a patterned electrode or a partition between pixels remains. In the case of application by a spray method, it is preferable that the droplets of the application liquid sprayed from the nozzle to the application surface are as small as possible because uniform film quality can be obtained. For that purpose, a solvent with high vapor pressure is mixed with the coating liquid, and a part of the solvent is volatilized from the sprayed coating droplet in the coating atmosphere, so that fine droplets are generated immediately before adhering to the substrate. Is preferred. Also, in order to obtain a more uniform film quality, it is necessary to secure time for the liquid film generated on the substrate to be leveled immediately after coating. In order to achieve this purpose, a slower drying solvent, that is, a vapor A technique in which a solvent having a low pressure is contained to some extent is used.

Specific examples of the solvent having a vapor pressure of 2 mmHg to 10 mmHg at 25 ° C. include organic solvents such as xylene, anisole, cyclohexanone, and toluene. Examples of the solvent having a vapor pressure of less than 2 mmHg at 25 ° C. include ethyl benzoate, methyl benzoate, tetralin, and phenetole.
The ratio of the mixed solvent is such that the solvent whose vapor pressure at 25 ° C. is 2 mmHg or more is 5% by weight or more, preferably 25% by weight or more, but less than 50% by weight, and the vapor pressure at 25 ° C. is 25% by weight. The solvent which is less than 2 mmHg is 30% by weight or more, preferably 50% by weight or more, particularly preferably 75% by weight or more, but less than 95% by weight in the total mixed solvent.

  In addition, since an organic electroluminescent element is formed by laminating a plurality of layers made of organic compounds, each layer is required to be a uniform layer. In the case of forming a layer by a wet film forming method, moisture may be mixed into the coating solution (composition) for forming the layer, so that moisture may be mixed into the coating film and the uniformity of the film may be impaired. It is preferable that the water content is as low as possible. Specifically, the amount of water contained in the organic electroluminescent element composition is preferably 1% by weight or less, more preferably 0.1% by weight or less, and still more preferably 0.05% by weight or less.

  In addition, since organic electroluminescent devices use many materials such as cathodes that are significantly deteriorated by moisture, the presence of moisture is not preferable from the viewpoint of device degradation. Examples of the method for reducing the amount of water in the solution include nitrogen gas sealing, use of a desiccant, dehydration of the solvent in advance, use of a solvent with low water solubility, and the like. Among these, the use of a solvent having low water solubility is preferable because the solution coating film can prevent whitening by absorbing moisture in the atmosphere during the coating process.

From such a viewpoint, the composition for organic electroluminescent elements of the present invention contains, for example, a solvent having a water solubility at 25 ° C. of 1% by weight or less (preferably 0.1% by weight or less) in the composition. It is preferable to contain 10% by weight or more. The solvent satisfying the above solubility condition is more preferably 30% by weight or more, and particularly preferably 50% by weight or more.
In addition, as a solvent contained in the composition for organic electroluminescent elements of this invention, you may contain various other solvents other than the solvent mentioned above as needed. Examples of such other solvents include amides such as N, N-dimethylformamide and N, N-dimethylacetamide; dimethyl sulfoxide and the like.
Moreover, the composition for organic electroluminescent elements of this invention may contain various additives, such as coating property improving agents, such as a leveling agent and an antifoamer.

[Film formation method]
As described above, since the organic electroluminescent element is formed by laminating a plurality of layers made of organic compounds, it is very important that the film quality is uniform. When a layer is formed by a wet film forming method, a film forming method such as a coating method such as a spin coating method or a spray method, or a printing method such as an ink jet method or a screen method can be adopted depending on the material and properties of the base.

  When using a wet film-forming method, the arylamine polymer of the present invention and other components used as necessary (electron-accepting compounds, additives that promote crosslinking reaction, coatability improvers, etc.) are used as appropriate solvents. Dissolve to prepare the composition for organic electroluminescence device. This composition is applied onto a layer corresponding to the lower layer of the layer to be formed by a technique such as spin coating or dip coating, dried, and then crosslinked to form the crosslinked layer in the present invention.

(Formation method of organic thin film)
When forming into a film using the composition for organic electroluminescent elements of this invention, it heats normally after application | coating.
The heating method is not particularly limited, but the conditions for heat drying are usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 150 ° C. or higher, and usually 400 ° C. or lower, preferably 350 ° C. or lower, more preferably Heats the layer formed using the composition for organic electroluminescent elements to 300 ° C. or lower. The heating time is usually 1 minute or longer, preferably 24 hours or shorter. Although it does not specifically limit as a heating means, Means, such as mounting the laminated body which has the formed layer on a hotplate, or heating in oven, is used. For example, conditions such as heating on a hot plate at 120 ° C. or more for 1 minute or more can be used.

  In the case of irradiation with active energy such as light, a method of irradiating directly using an ultraviolet / visible / infrared light source such as an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a halogen lamp, an infrared lamp, or the above-mentioned light source is incorporated. Examples include a mask aligner and a method of irradiation using a conveyor type light irradiation device. In active energy irradiation other than light, for example, there is a method of irradiation using a so-called microwave oven that irradiates a microwave generated by a magnetron.

As the irradiation time, it is preferable to set conditions necessary for sufficient crosslinking reaction to occur, but irradiation is usually performed for 0.1 seconds or longer, preferably 10 hours or shorter.
The irradiation of active energy such as heating and light may be performed alone or in combination. When combined, the order of implementation is not particularly limited.
In order to reduce the amount of moisture contained in the layer and / or moisture adsorbed on the surface after execution, the irradiation of active energy such as heating and light is preferably performed in an atmosphere containing no moisture such as a nitrogen gas atmosphere. For the same purpose, when combined with heating and / or irradiation with active energy such as light, it is particularly preferable to perform at least the process immediately before the formation of the light emitting layer in an atmosphere containing no moisture such as a nitrogen gas atmosphere.

<Organic electroluminescent device>
The organic electroluminescent device of the present invention is an organic electroluminescent device having an anode, a cathode, and an organic layer disposed between the anode and the cathode on a substrate, wherein the organic layer is an arylamine polymer of the present invention. Or a layer formed by crosslinking the arylamine polymer of the present invention (hereinafter, referred to as “crosslinked layer of the present invention”) when the arylamine polymer of the present invention has a crosslinkable group. ).

Furthermore, in the organic electroluminescent element of the present invention, the layer containing the arylamine polymer of the present invention or the crosslinked layer is preferably a hole injection layer and / or a hole transport layer.
The layer containing the arylamine polymer of the present invention or the cross-linked layer is preferably formed by a wet film formation method using the composition for organic electroluminescent elements of the present invention.
Moreover, it is preferable to have a light emitting layer formed by a wet film forming method on the cathode side of the hole transport layer, and further, formed on the anode side of the hole transport layer by a wet film forming method. It is preferable to have a hole injection layer. That is, in the organic electroluminescent element of the present invention, it is preferable that all of the hole injection layer, the hole transport layer, and the light emitting layer are formed by a wet film forming method. In particular, the light emitting layer formed by this wet film forming method is preferably a layer made of a low molecular material.

  FIG. 1 is a cross-sectional view schematically showing an example of the structure of the organic electroluminescent element of the present invention. The organic electroluminescent device shown in FIG. 1 is configured by laminating an anode, a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron injection layer, and a cathode in this order on a substrate. . In the case of this configuration, the hole transport layer usually corresponds to the organic compound-containing layer of the present invention described above.

[1] Substrate
The substrate serves as a support for the organic electroluminescence device, and quartz or glass plates, metal plates or metal foils, plastic films or sheets are used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic electroluminescent element may be deteriorated by the outside air that has passed through the substrate, which is not preferable. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also a preferable method.

[2] Anode
The anode plays a role of hole injection into a layer on the light emitting layer side (hole injection layer, light emitting layer, or the like) described later. This anode is usually made of metal such as aluminum, gold, silver, nickel, palladium, platinum, metal oxide such as oxide of indium and / or tin, metal halide such as copper iodide, carbon black, or poly It is composed of conductive polymers such as (3-methylthiophene), polypyrrole, and polyaniline. In general, the anode is often formed by a sputtering method, a vacuum deposition method, or the like. Also, in the case of fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, etc., it is dispersed in an appropriate binder resin solution and placed on the substrate. An anode can also be formed by coating. Furthermore, in the case of a conductive polymer, a thin film can be directly formed on a substrate by electrolytic polymerization, or an anode can be formed by applying a conductive polymer on a substrate (Applied
Physics Letters, 1992, Vol. 60, pp. 2711). The anode can be formed by stacking different materials.

The thickness of the anode varies depending on the required transparency. When transparency is required, it is desirable that the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness is usually 5 nm or more, preferably 10 nm or more, Usually, it is 1000 nm or less, preferably 500 nm or less. If it may be opaque, the anode may be the same as the substrate. Furthermore, it is also possible to laminate different conductive materials on the anode.
In addition, the surface of the anode is treated with ultraviolet (UV) / ozone, oxygen plasma, or argon plasma for the purpose of removing impurities adhering to the anode and adjusting the ionization potential to improve the hole injection property. Is preferred.

[3] Hole injection layer
A hole injection layer is formed on the anode.
The hole injection layer is a layer that transports holes to a layer adjacent to the cathode side of the anode.
The organic electroluminescent device of the present invention may have a configuration in which the hole injection layer is omitted.
The hole injection layer preferably contains a hole transporting compound, and more preferably contains a hole transporting compound and an electron accepting compound. Further, the hole injection layer preferably contains a cation radical compound, and particularly preferably contains a cation radical compound and a hole transporting compound.

The hole injection layer may contain a binder resin and a coating property improving agent as necessary. The binder resin is preferably one that hardly acts as a charge trap.
The hole injection layer can be formed by depositing only the electron-accepting compound on the anode by a wet film-forming method, and directly applying and laminating the charge transport material composition thereon. In this case, a part of the charge transport material composition interacts with the electron-accepting compound, so that a layer excellent in hole injecting property is formed.

(Hole transporting compound)
As said hole transportable compound, the compound which has the ionization potential of 4.5 eV-6.0 eV is preferable. However, when used in the wet film forming method, it is preferable that the solubility in the solvent used in the wet film forming method is high.
The hole-transporting compound is preferably the arylamine polymer of the present invention from the viewpoint of excellent film-forming properties and high charge injection / transporting ability. That is, it is preferable to form a layer using the composition for organic electroluminescent elements of the present invention.

When a compound other than the arylamine polymer of the present invention is used as the hole transporting compound, examples of the hole transporting compound include aromatic amine compounds, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, and the like. . Of these, aromatic amine compounds are preferred from the viewpoints of amorphousness and visible light transmittance.
The type of the aromatic amine compound is not particularly limited, and may be a low molecular compound or a high molecular compound. From the viewpoint of the surface smoothing effect, a polymer having a weight average molecular weight of 1,000 or more and 1,000,000 or less. A compound (polymerizable hydrocarbon compound in which repeating units are continuous) is preferred.
Preferable examples of the aromatic tertiary amine polymer compound also include a polymer compound having a repeating unit represented by the following formula (1).

(In the above formula (1), Ar ^b1 and Ar ^b2 are each independently an aromatic hydrocarbon ring group which may have a substituent, or an aromatic heterocycle which may have a substituent. Represents a group Ar ^b3 to
Ar ^b5 each independently represents an aromatic hydrocarbon ring group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Z ^b represents a linking group selected from the following linking group group. Of Ar ^{b1 to} Ar ^b5 , two groups bonded to the same N atom may be bonded to each other to form a ring. )

(In the above formulas, Ar ^{b6 to} Ar ^b16 are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent. R ^b1 and R ^b2 each independently represents a hydrogen atom or an arbitrary substituent.
As Ar ^{b1 to} Ar ^b16 , a monovalent or divalent group derived from any aromatic hydrocarbon ring or aromatic heterocycle is applicable. These groups may be the same or different from each other. Further, these groups may further have an arbitrary substituent.

Specific examples of the aromatic tertiary amine polymer compound having a repeating unit represented by the general formula (1) include compounds described in International Publication No. 2005/089024 pamphlet.
The hole transporting compound used as the material for the hole injection layer may contain any one of these compounds alone, or may contain two or more.

In the case of containing two or more kinds of hole transporting compounds, the combination is arbitrary, but one or more kinds of aromatic tertiary amine polymer compounds and one or two kinds of other hole transporting compounds. It is preferable to use the above together.
(Electron-accepting compound)
As the electron-accepting compound, the above <7. This is the same as that described in the section “Composition for organic electroluminescence device>. The same applies to preferred specific examples.

(Cation radical compound)
As the cation radical compound, an ionic compound composed of a cation radical which is a chemical species obtained by removing one electron from a hole transporting compound and a counter anion is preferable. However, when the cation radical is derived from a hole transporting polymer compound, the cation radical has a structure in which one electron is removed from the repeating unit of the polymer compound.

The cation radical is preferably a chemical species obtained by removing one electron from the compound described above as the hole transporting compound. A chemical species obtained by removing one electron from a compound preferable as a hole transporting compound is preferable in terms of amorphousness, visible light transmittance, heat resistance, solubility, and the like.
Here, the cation radical compound can be generated by mixing the hole transporting compound and the electron accepting compound. That is, by mixing the hole transporting compound and the electron accepting compound, electron transfer occurs from the hole transporting compound to the electron accepting compound, and the cation radical and the counter anion of the hole transporting compound A cation ion compound consisting of

Cationic radical compounds derived from polymer compounds such as PEDOT / PSS (Adv. Mater., 2000, 12, 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, 94, 7716) It is also produced by oxidative polymerization (dehydrogenation polymerization).
Oxidative polymerization here refers to oxidation of a monomer chemically or electrochemically with peroxodisulfate in an acidic solution. In the case of this oxidative polymerization (dehydrogenation polymerization), the monomer is polymerized by oxidation, and a cation radical that is removed from the polymer repeating unit by using an anion derived from an acidic solution as a counter anion is removed. Generate.

The hole injection layer can be formed by either a wet film formation method or a dry film formation method such as a vacuum deposition method. The film is preferably formed by a wet film forming method from the viewpoint of excellent film forming properties.
The thickness of the hole injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.
The content of the electron-accepting compound in the hole-injecting layer with respect to the hole-transporting compound is usually 0.1 mol% or more, preferably 1 mol% or more. However, it is usually 100 mol% or less, preferably 40 mol% or less.

(Other components)
As a material for the hole injection layer, other components may be further contained in addition to the above-described hole transporting compound and electron accepting compound as long as the effects of the present invention are not significantly impaired. Examples of other components include various light emitting materials, electron transporting compounds, binder resins, and coating property improving agents. In addition, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and ratios.

(solvent)
At least one of the solvents of the composition for forming a hole injection layer used in the wet film formation method is preferably a compound that can dissolve the constituent material of the hole injection layer. The boiling point of this solvent is usually 110 ° C. or higher, preferably 140 ° C. or higher, particularly 200 ° C. or higher, usually 400 ° C. or lower, and preferably 300 ° C. or lower. If the boiling point of the solvent is too low, the drying speed is too high and the film quality may be deteriorated. Further, if the boiling point of the solvent is too high, it is necessary to increase the temperature of the drying step, which may adversely affect other layers and the substrate.

Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, amide solvents, and the like.
Examples of ether solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole , Phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, aromatic ethers such as 2,4-dimethylanisole, and the like.

Examples of the ester solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.
Examples of the aromatic hydrocarbon solvent include toluene, xylene, cyclohexylbenzene, 3-isopropylpropylphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene. Can be mentioned.
Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, and the like.
In addition, dimethyl sulfoxide and the like can also be used.
These solvent may use only 1 type and may use 2 or more types by arbitrary combinations and a ratio.

(Film formation method)
After preparing the composition for forming a hole injection layer, the composition is applied onto a layer corresponding to the lower layer of the hole injection layer (usually an anode) by wet film formation and dried to form a hole injection layer. Form.
The temperature in the film forming step is preferably 10 ° C. or higher, and preferably 50 ° C. or lower in order to prevent film loss due to the formation of crystals in the composition.
Although the relative humidity in a film-forming process is not limited unless the effect of this invention is impaired remarkably, it is 0.01 ppm or more normally and 80% or less normally.
After coating, the film of the composition for forming a hole injection layer is usually dried by heating or the like. As a drying method, a heating step is usually performed. Examples of the heating means used in the heating step include a clean oven, a hot plate, infrared rays, a halogen heater, microwave irradiation and the like. Among them, a clean oven and a hot plate are preferable in order to uniformly apply heat to the entire film.

  The heating temperature in the heating step is preferably heated at a temperature equal to or higher than the boiling point of the solvent used in the composition for forming a hole injection layer as long as the effects of the present invention are not significantly impaired. In the case of a mixed solvent containing two or more types of solvents used in the composition for forming a hole injection layer, it is preferable that at least one type is heated at a temperature equal to or higher than the boiling point of the solvent. In consideration of an increase in the boiling point of the solvent, the heating step is preferably performed at 120 ° C. or higher, preferably 410 ° C. or lower.

  In the heating step, the heating temperature is preferably equal to or higher than the boiling point of the solvent of the composition for forming a hole injection layer. The heating time is not limited as long as the coating film does not sufficiently crosslink, but is preferably 10 seconds or longer and usually 180 minutes or shorter. If the heating time is too long, the components of the other layers tend to diffuse, and if it is too short, the hole injection layer tends to be inhomogeneous. Heating may be performed in two steps.

<Formation of hole injection layer by vacuum deposition>
When forming the hole injection layer by vacuum deposition, one or more of the constituent materials of the hole injection layer (the aforementioned hole transporting compound, electron accepting compound, etc.) are placed in a vacuum vessel. Put in crucibles (if more than one material is used, put them in each crucible), evacuate the vacuum vessel to about 10-4 Pa with a suitable vacuum pump, then heat the crucible (two or more materials) When using a crucible, heat each crucible) and control the evaporation amount to evaporate (when using two or more materials, evaporate by controlling the evaporation amount independently) and place it facing the crucible A hole injection layer is formed on the anode of the substrate. In addition, when using 2 or more types of materials, those hole mixture layers can also be formed by putting them in a crucible and heating and evaporating them.

The degree of vacuum at the time of vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 × 10 ⁻⁶ Torr (0.13 × 10 ⁻⁴ Pa) or more, usually 9.0 × 10 ⁻⁶ Torr. (12.0 × 10 ⁻⁴ Pa) or less. The deposition rate is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 Å / second or more and usually 5.0 Å / second or less. The film forming temperature at the time of vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 10 ° C. or higher, preferably 50 ° C. or lower.
The thickness of the hole injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[4] Hole transport layer
The hole transport layer can be formed on the hole injection layer when there is a hole injection layer and on the anode when there is no hole injection layer. The organic electroluminescent device of the present invention may have a configuration in which the hole transport layer is omitted.
The material for forming the hole transport layer is preferably a material having a high hole transport capability and capable of efficiently transporting the injected holes. Therefore, it is preferable that the ionization potential is small, the transparency to visible light is high, the hole mobility is large, the stability is high, and impurities that become traps are not easily generated during manufacturing or use. In many cases, since it is in contact with the light emitting layer, it is preferable not to quench the light emitted from the light emitting layer or to reduce the efficiency by forming an exciplex with the light emitting layer.

As the hole transporting compound, the arylamine polymer of the present invention is particularly preferable from the above points. When a compound other than the arylamine polymer of the present invention is used as the hole transporting compound, a material conventionally used as a constituent material of the hole transport layer can be used. Examples of conventionally used materials include those exemplified as the hole transporting compound used in the above-described hole injection layer. In addition, two or more condensed aromatic rings including two or more tertiary amines represented by 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl are substituted with nitrogen atoms. Aromatic amine compounds having a starburst structure such as aromatic diamines (Japanese Patent Laid-Open No. Hei 5-23481), 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine (J. Lumin. 72-74, 985, 1997), aromatic amine compounds consisting of tetramers of triphenylamine (Chem. Commun., 2175, 1996), 2,2 ′, 7,7′-tetrakis. Spiro compounds such as-(diphenylamino) -9,9'-spirobifluorene (Synt
h. Metals, 91, 209, 1997), and carbazole derivatives such as 4,4′-N, N′-dicarbazolebiphenyl. Further, for example, polyvinyl carbazole, polyvinyl triphenylamine (Japanese Patent Laid-Open No. 7-53953), polyarylene ether sulfone (Polym. Adv. Tech., 7, 33, 1996) containing tetraphenylbenzidine, etc. Can be mentioned.

When the hole transport layer is formed by wet film formation, a composition for forming a hole transport layer is prepared in the same manner as in the formation of the hole injection layer, and then heated and dried after coating.
The composition for forming a hole transport layer contains a solvent in addition to the above hole transport compound. The solvent used is the same as that used for the composition for forming a hole injection layer. Also, the coating conditions, heating and drying conditions, and the like are the same as in the case of forming the hole injection layer.

In the case of forming the hole transport layer by vacuum deposition, the film forming conditions are the same as in the case of forming the hole injection layer.
The hole transport layer may contain various light emitting materials, electron transport compounds, binder resins, coatability improvers, and the like in addition to the hole transport compound.
The hole transport layer may also be a layer formed by crosslinking a crosslinkable compound. The crosslinkable compound is a compound having a crosslinkable group, and forms a network polymer compound by crosslinking.

Examples of such crosslinkable groups include cyclic ether groups such as oxetane groups and epoxy groups; groups containing unsaturated double bonds such as vinyl groups, trifluorovinyl groups, styryl groups, acrylic groups, methacryloyl groups, and cinnamoyl groups. A group derived from a benzocyclobutene ring;
The crosslinkable compound may be any of a monomer, an oligomer, and a polymer. The crosslinkable compound may have only 1 type, and may have 2 or more types by arbitrary combinations and ratios.

  As the crosslinkable compound, a hole transporting compound having a crosslinkable group is preferably used. Examples of hole transporting compounds include nitrogen-containing aromatic compound derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives, phthalocyanine derivatives, porphyrin derivatives; triphenylamine derivatives Silole derivatives; oligothiophene derivatives, condensed polycyclic aromatic derivatives, metal complexes and the like. Among them, nitrogen-containing aromatic derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives; triphenylamine derivatives, silole derivatives, condensed polycyclic aromatic derivatives, metal complexes, etc. Particularly preferred are triphenylamine derivatives.

In order to form a hole transport layer by crosslinking a crosslinkable compound, a composition for forming a hole transport layer in which a crosslinkable compound is dissolved or dispersed in a solvent is usually prepared and applied by wet film formation to crosslink. Let
The composition for forming a hole transport layer may contain an additive for promoting a crosslinking reaction in addition to the crosslinking compound. Examples of additives that promote the crosslinking reaction include polymerization initiators and polymerization accelerators such as alkylphenone compounds, acylphosphine oxide compounds, metallocene compounds, oxime ester compounds, azo compounds, onium salts; condensed polycyclic hydrocarbons, And photosensitizers such as porphyrin compounds and diaryl ketone compounds.

Further, it may contain a coating property improving agent such as a leveling agent and an antifoaming agent; an electron accepting compound; a binder resin;
In the composition for forming a hole transport layer, the crosslinkable compound is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, usually 50% by weight or less, preferably 20%. It is contained by weight% or less, more preferably 10% by weight or less.

After forming a composition for forming a hole transport layer containing a crosslinkable compound at such a concentration on a lower layer (usually a hole injection layer), the crosslinkable compound is formed by heating and / or irradiation with active energy such as light. It is crosslinked to form a network polymer compound.
Conditions such as temperature and humidity during coating, and heating conditions after coating are described in <7. Organic electroluminescence device> Same as the method described in [Film formation method]. Moreover, a preferable aspect is also the same.
The thickness of the hole transport layer is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[5] Light emitting layer
The light emitting layer is formed on the hole transport layer when there is a hole transport layer, and on the hole injection layer when there is no hole transport layer without the hole transport layer. When there is no hole injection layer, it is formed on the anode.
The light emitting layer may be a layer independent of the hole injection layer, the hole transport layer, and the hole blocking layer, the electron transport layer, etc., which will be described later, but does not form an independent light emitting layer. Other organic layers such as a transport layer and an electron transport layer may serve as the light emitting layer.
The light-emitting layer is formed by directly injecting holes from an anode or through a hole injection layer or a hole transport layer between electrodes to which an electric field is applied, and directly from a cathode, or a cathode buffer layer or an electron transport layer. It is a layer that is excited by recombination with electrons injected through a hole blocking layer or the like and becomes a main light emitting source.

The light emitting layer can be formed by any method as long as the effects of the present invention are not significantly impaired. For example, the light emitting layer is formed on the anode by a wet film forming method or a vacuum deposition method. However, in the case of manufacturing a light emitting element having a large area, the wet film forming method is preferable. The wet film formation method and the vacuum deposition method can be performed using the same method as the hole injection layer.
The light emitting layer contains at least a material having a light emitting property (light emitting material), and preferably a material having a hole transporting property (hole transporting material) or a material having an electron transporting property (electron). Transport material). Furthermore, the light emitting layer may contain other components without departing from the spirit of the present invention. As these materials, it is preferable to use low molecular weight materials from the viewpoint of forming a light emitting layer by a wet film forming method as described later.

Any known material can be applied as the light emitting material. For example, a fluorescent material or a phosphorescent material may be used, but a phosphorescent material is preferable from the viewpoint of internal quantum efficiency.
In order to improve the solubility in a solvent, it is also important to reduce the symmetry and rigidity of the molecules of the luminescent material, or to introduce a lipophilic substituent such as an alkyl group.
Hereinafter, although the example of a fluorescent dye is mentioned among light emitting materials, a fluorescent dye is not limited to the following illustrations.

Examples of the fluorescent light-emitting material (blue fluorescent dye) that emits blue light include naphthalene, chrysene, perylene, pyrene, anthracene, coumarin, p-bis (2-phenylethenyl) benzene, and derivatives thereof.
Examples of fluorescent dyes that give green light emission (green fluorescent dyes) include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al (C ₉ H ₆ NO) ₃ .

Examples of the fluorescent light emitting material (yellow fluorescent dye) that gives yellow light include rubrene, perimidone derivatives, and the like.
Examples of the fluorescent light-emitting material (red fluorescent dye) that emits red light include, for example, DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) -based compounds, benzopyran derivatives, rhodamine derivatives, Examples thereof include benzothioxanthene derivatives and azabenzothioxanthene.

  Specific examples of the phosphorescent material include tris (2-phenylpyridine) iridium, tris (2-phenylpyridine) ruthenium, tris (2-phenylpyridine) palladium, bis (2-phenylpyridine) platinum, tris (2- Phenylpyridine) osmium, tris (2-phenylpyridine) rhenium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, octaphenyl palladium porphyrin, and the like.

Polymeric light-emitting materials include poly (9,9-dioctylfluorene-2,7-diyl), poly [(9,9-dioctylfluorene-2,7-diyl) -co- (4,4′- (N
-(4-sec-butylphenyl)) diphenylamine)], poly [(9,9-dioctylfluorene-2,7-diyl) -co- (1,4-benzo-2 {2,1'-3}- And polyfluorene-based materials such as poly [2-methoxy-5- (2-hexylhexyloxy) -1,4-phenylenevinylene].

The arylamine polymer of the present invention can also be used as a light emitting material.
The molecular weight of the compound used as the light emitting material is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 10,000 or less, preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, and usually 100 or more, Preferably it is 200 or more, More preferably, it is 300 or more, More preferably, it is the range of 400 or more. If the molecular weight of the luminescent material is too small, the heat resistance will be significantly reduced, gas will be generated, the film quality will deteriorate when the film is formed, or the morphology of the organic electroluminescent element will change due to migration, etc. Sometimes come. On the other hand, if the molecular weight of the luminescent material is too large, it tends to be difficult to purify the organic compound, or it may take time to dissolve in the solvent.

In addition, any 1 type may be used for the luminescent material mentioned above, and 2 or more types may be used together by arbitrary combinations and a ratio.
The ratio of the light emitting material in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.05% by weight or more, and preferably 35% by weight or less. If the amount of the light emitting material is too small, uneven light emission may occur. If the amount is too large, the current efficiency may decrease. In addition, when using together 2 or more types of luminescent material, it is made for the total content of these to be contained in the said range.

Examples of the low molecular weight hole transport material include various compounds exemplified as the hole transport material of the above-described hole transport layer, and 4,4′-bis [N- (1-naphthyl) -N—. Aromatic diamines, including two or more tertiary amines, represented by phenylamino] biphenyl, wherein two or more condensed aromatic rings are substituted with nitrogen atoms (Japanese Patent Laid-Open No. 5-234681), 4, 4 ′, Aromatic amine compounds having a starburst structure such as 4 "-tris (1-naphthylphenylamino) triphenylamine (Journal of Luminescence, 1997, Vol.72-74, pp.985), tetramer of triphenylamine Aromatic amine compounds (Chemical Communications, 1996, pp.2175), spiro compounds such as 2,2 ′, 7,7′-tetrakis- (diphenylamino) -9,9′-spirobifluorene (Synthetic Metals, 1997, Vol.91, pp.209 )
Etc.

  Examples of low molecular weight electron transport materials include 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND) and 2,5-bis (6 ′-(2 ′, 2 "-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), bathophenanthroline (BPhen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) , Bathocuproine), 2- (4-biphenylyl) -5- (p-tertiarybutylphenyl) -1,3,4-oxadiazole (tBu-PBD) and 4,4′-bis (9-carbazole) -Biphenyl (CBP), 9,10-di- (2-naphthyl) anthracene (ADN) and the like.

These hole transport materials and electron transport materials are preferably used as host materials in the light emitting layer. Specific examples of the host material include those described in JP-A-2007-067383, JP-A-2007-88433, and JP-A-2007-110093, and preferred examples thereof are also the same.
Examples of the method for forming the light emitting layer include a wet film formation method and a vacuum deposition method.
From the point that a homogeneous and defect-free thin film can be easily obtained, the time required for formation can be shortened, and the effect of crosslinking the hole transport layer by the organic compound of the present invention can be enjoyed. The membrane method is preferred. When forming a light-emitting layer by a wet film formation method, prepare the coating solution by dissolving the above materials in an appropriate solvent, apply it to the hole transport layer after the above-mentioned formation, coat it, and dry it. Then, it is formed by removing the solvent. The formation method is the same as the formation method of the hole transport layer.
The thickness of the light emitting layer is usually 3 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[6] Hole blocking layer
A hole blocking layer 6 may be provided between the light emitting layer 5 and an electron injection layer 8 described later. The hole blocking layer 6 is a layer laminated on the light emitting layer 5 so as to be in contact with the interface of the light emitting layer 5 on the cathode 9 side.
The hole blocking layer 6 has a role of blocking holes moving from the anode 2 from reaching the cathode 9 and a role of efficiently transporting electrons injected from the cathode 9 toward the light emitting layer 5. Have
The physical properties required for the material constituting the hole blocking layer 6 include high electron mobility, low hole mobility, a large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). Is high. Examples of the material for the hole blocking layer satisfying such conditions include bis (2-methyl-8-quinolinolato) (phenolato) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanolato) aluminum, and the like. Mixed metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes, distyrylbiphenyl derivatives, etc. Triazole derivatives such as styryl compounds (JP-A-11-242996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (JP-A-7 -41759), phenanthroline derivatives such as bathocuproine (JP-A-10-79297), and the like. That. Further, a compound having at least one pyridine ring substituted at the 2,4,6-position described in International Publication No. 2005-022962 is also preferable as the material for the hole blocking layer 6.

In addition, the material of the hole-blocking layer 6 may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of the hole-blocking layer 6. FIG. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods.
The thickness of the hole blocking layer 6 is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[7] Electron transport layer
The electron transport layer is provided between the light emitting layer and the electron injection layer for the purpose of further improving the current efficiency of the device.
The electron transport layer is formed of a compound capable of efficiently transporting electrons injected from the cathode between the electrodes to which an electric field is applied in the direction of the light emitting layer. The electron transporting compound used in the electron transporting layer is a compound that has high electron injection efficiency from the cathode or the electron injection layer and has high electron mobility and can efficiently transport injected electrons. It is necessary.

Materials satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadiazole derivatives, Styryl biphenyl derivatives, silole derivatives, 3- or 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948)
No.), quinoxaline compound (JP-A-6-207169), phenanthroline derivative (JP-A-5-331459), 2-t-butyl-9,10-N, N′-dicyanoanthraquinonediimine, n Type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide and the like.

The lower limit of the thickness of the electron transport layer is usually 1 nm, preferably about 5 nm, and the upper limit is usually 300 nm, preferably about 100 nm.
The electron transport layer is formed by laminating on the hole blocking layer by a wet film formation method or a vacuum deposition method in the same manner as described above. Usually, a vacuum deposition method is used.

[8] Electron injection layer
The electron injection layer plays a role of efficiently injecting electrons injected from the cathode into the electron transport layer or the light emitting layer.
In order to perform electron injection efficiently, the material for forming the electron injection layer is preferably a metal having a low work function. Examples include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. The film thickness is usually preferably from 0.1 nm to 5 nm.
Further, organic electron transport materials represented by metal complexes such as nitrogen-containing heterocyclic compounds such as bathophenanthroline and aluminum complexes of 8-hydroxyquinoline described later are doped with alkali metals such as sodium, potassium, cesium, lithium and rubidium. (Described in JP-A-10-270171, JP-A 2002-1000047, JP-A 2002-1000048, and the like) makes it possible to improve electron injection / transport properties and achieve excellent film quality. Therefore, it is preferable. The film thickness in this case is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injection layer is formed by laminating on the light emitting layer or the hole blocking layer thereon by a wet film formation method or a vacuum deposition method.
Details of the wet film forming method are the same as those of the hole injection layer and the light emitting layer.
On the other hand, in the case of the vacuum vapor deposition method, a vapor deposition source is put into a crucible or a metal boat installed in a vacuum vessel, the inside of the vacuum vessel is evacuated to about 10 −4 Pa with an appropriate vacuum pump, and then the crucible or the metal boat. Is heated and evaporated to form an electron injection layer on the light-emitting layer, hole blocking layer or electron transport layer on the substrate placed facing the crucible or metal boat.

The alkali metal as the electron injection layer is deposited by using an alkali metal dispenser in which nichrome is filled with an alkali metal chromate and a reducing agent. By heating the dispenser in a vacuum container, the alkali metal chromate is reduced and the alkali metal is evaporated. When the organic electron transport material and the alkali metal are co-evaporated, the organic electron transport material is put in a crucible installed in a vacuum vessel, and the inside of the vacuum vessel is exhausted to about 10 −4 Pa with an appropriate vacuum pump. Each crucible and dispenser are simultaneously heated and evaporated to form an electron injection layer on the substrate placed facing the crucible and dispenser.
At this time, co-evaporation is uniformly performed in the film thickness direction of the electron injection layer, but there may be a concentration distribution in the film thickness direction.

[9] Cathode
The cathode plays a role of injecting electrons into a layer on the light emitting layer side (such as an electron injection layer or a light emitting layer). As the material of the cathode, it is possible to use the material used for the anode, but in order to efficiently inject electrons, a metal having a low work function is preferable, and tin, magnesium, indium, calcium, aluminum, A suitable metal such as silver or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

The thickness of the cathode is usually the same as that of the anode.
For the purpose of protecting the cathode made of a low work function metal, it is preferable to further stack a metal layer having a high work function and stable to the atmosphere because the stability of the device is increased. For this purpose, metals such as aluminum, silver, copper, nickel, chromium, gold, platinum are used.

[10] Other
The organic electroluminescent element having the layer configuration shown in FIG. 1 has been described above as an example. However, the organic electroluminescent element of the present invention may have another configuration without departing from the gist thereof. For example, as long as the performance is not impaired, an arbitrary layer may be provided between the anode and the cathode in addition to the layers described above, and an arbitrary layer may be omitted.
In the present invention, by using the arylamine polymer of the present invention for the hole transport layer, all of the hole injection layer, the hole transport layer and the light emitting layer can be laminated by a wet film formation method. This makes it possible to manufacture a large area display.
In addition, the structure opposite to that shown in FIG. 1, that is, a cathode, an electron injection layer, a light emitting layer, a hole injection layer, and an anode can be laminated in this order on a substrate, and at least one of them is transparent as described above. It is also possible to provide the organic electroluminescence device of the present invention between two high-height substrates.

Further, a structure in which a plurality of layers shown in FIG. 1 are stacked (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, the interfacial layer (between the light emitting units) (the anode is ITO)
If, for example, V ₂ O ₅ or the like is used as the charge generation layer (CGL) instead of the two layers when the cathode is Al, the barrier between the stages is reduced, which is more preferable from the viewpoint of current efficiency and driving voltage.
The present invention can be applied to any of an organic electroluminescent element having a single element, an element having a structure arranged in an array, and a structure having an anode and a cathode arranged in an XY matrix.

<Organic EL display device>
The organic EL display device of the present invention uses the above-described organic electroluminescent element of the present invention. There is no restriction | limiting in particular about the model and structure of the organic electroluminescent display apparatus of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.
For example, the organic EL display device of the present invention can be obtained by the method described in “Organic EL display” (Ohm, published on Aug. 20, 2004, Shizushi Tokito, Chiba Adachi, Hideyuki Murata). Can be formed.

<Organic EL lighting>
The organic EL illumination of the present invention uses the above-described organic electroluminescent element of the present invention. There is no restriction | limiting in particular about the model and structure of the organic EL illumination of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.

EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.
(Synthesis Example 1: Synthesis of Polymer 1)

Compound 1 (1.721 g, 11.538 mmol), Compound 2 (0.5734 g, 2.9364 mmol), Compound 3 (0.443 g, 4.7556 mmol), Compound 4 (3.0 g, 9.615 mmol) and tert- Sodium butoxy (6.2 g, 65.38 mmol), toluene (
15 ml) was charged, the inside of the system was sufficiently purged with nitrogen, and the mixture was heated to 60 ° C. (solution A). Tri-t-butylphosphine (0.311 g, 1.536 mmol) was added to a 10 ml toluene solution of tris (dibenzylideneacetone) dipalladium chloroform complex (0.2 g, 0.192 mmol) and heated to 60 ° C. ( Solution B). Solution B was added to solution A in a nitrogen stream and heated to reflux for 2.0 hours. After confirming that compounds 1 to 4 had disappeared, compound 5 (2.18 g, 9.2304 mmol) was additionally added. After heating under reflux for 1.0 hour, the reaction solution was allowed to cool, and the reaction solution was dropped into 500 ml of ethanol to crystallize crude polymer 1.

The obtained crude polymer 1 was dissolved in 60 ml of toluene, bromobenzene (0.6 g) and tert-butoxy sodium (6.2 g) were charged, the inside of the system was sufficiently purged with nitrogen, and the mixture was heated to 60 ° C. ( Solution C). Tri-t-butylphosphine (0.311 g, 1.536 mmol) was added to a 10 ml toluene solution of tris (dibenzylideneacetone) dipalladium chloroform complex (0.2 g), and the mixture was heated to 60 ° C. (solution D). In a nitrogen stream, solution D was added to solution C, and heated to reflux for 2 hours. N, N-diphenylamine (3.25 g) was added to the reaction solution. The reaction was heated to reflux for 4 hours. The reaction solution was allowed to cool and added dropwise to an ethanol / water (500 ml / 80 ml) solution to obtain an end-capped crude polymer 1 ′.

This end-capped crude polymer 1 ′ was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was separated by filtration. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The polymer collected by filtration was purified by column chromatography to obtain polymer 1 (1.0 g).
Weight average molecular weight (Mw) = 52000
Number average molecular weight (Mn) = 33900
Dispersity (Mw / Mn) = 1.53
(Reference Example 1: Synthesis of polymer 2)

Compound 6 (1.681 g, 4.8077 mmol), Compound 2 (0.566 g, 2.9006 mmol), Compound 3 (0.774 g, 8.173 mmol), Compound 4 (2.5 g, 8.0128 mmol) and tert- Sodium butoxy (5.2 g, 54.49 mmol), toluene (
18 ml) was charged, the inside of the system was sufficiently purged with nitrogen, and the mixture was heated to 60 ° C. (solution A). Tri-t-butylphosphine (0.264 g, 1.304 mmol) was added to a solution of tris (dibenzylideneacetone) dipalladium chloroform complex (0.169 g, 0.1603 mmol) in toluene 8 ml, and the mixture was heated to 60 ° C. ( Solution B). Solution B was added to solution A in a nitrogen stream and heated to reflux for 2.0 hours. After confirming disappearance of Compound 6 and Compounds 2-4, Compound 5 (1.815 g, 7.692 mmol) was added additionally. After heating under reflux for 1.0 hour, the reaction solution was allowed to cool, and the reaction solution was dropped into 450 ml of ethanol to crystallize the crude polymer 2.

The obtained crude polymer 2 was dissolved in 100 ml of toluene, bromobenzene (0.5 g) and tert-butoxy sodium (5.2 g) were charged, and the inside of the system was sufficiently purged with nitrogen.
(Solution C). Tri-t-butylphosphine (0.264 g, 1.304 mmol) was added to a toluene 8 ml solution of tris (dibenzylideneacetone) dipalladium chloroform complex (0.169 g), and the mixture was heated to 60 ° C. (solution D). In a nitrogen stream, solution D was added to solution C, and heated to reflux for 2 hours. N, N-diphenylamine (2.7 g) was added to the reaction solution. The reaction was heated to reflux for 4 hours. The reaction solution was allowed to cool and added dropwise to an ethanol / water (500 ml / 80 ml) solution to obtain an end-capped crude polymer 2 ′.

This end-capped crude polymer 2 ′ was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was separated by filtration. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The polymer collected by filtration was purified by column chromatography to obtain polymer 2 (1.5 g).
Weight average molecular weight (Mw) = 59000
Number average molecular weight (Mn) = 34100
Dispersity (Mw / Mn) = 1.73
(Synthesis Example 2: Synthesis of Polymer 3)

4,4′-dibromobiphenyl (3.000 g), 4-sec-butylaniline (1.722 g), compound 2 (0.9999 g), aniline (0.2398 g), tert-butoxy sodium (5.914 g), And toluene (25 ml) were charged, the inside of the system was sufficiently substituted with nitrogen, and the mixture was heated to 65 ° C. (solution A).
Meanwhile, tri-t-butylphosphine (0.311 g) was added to a toluene solution (5 ml) of tris (dibenzylideneacetone) dipalladium chloroform complex (0.199 g), and the mixture was heated to 65 ° C. (solution B).

In a nitrogen stream, solution B was added to solution A and heated to reflux for 2 hours. P-Dibromobenzene (2.087 g) was added to the reaction solution, and the mixture was heated to reflux for 1 hour. Further, p-dibromobenzene (0.090 g) was added and reacted for 2 hours.
The reaction solution was allowed to cool, and the reaction solution was dropped into 300 mL of ethanol to crystallize the crude polymer 3.

The obtained crude polymer 3 was dissolved in 250 mL of toluene, bromobenzene (0.604 g) and tert-butoxy sodium (5.91 g) were charged, the inside of the system was sufficiently purged with nitrogen, and the mixture was heated to 65 ° C. ( Solution C).
On the other hand, tri-t-butylphosphine (0.156 g) was added to 6 mL of a toluene solution of tris (dibenzylideneacetone) dipalladium chloroform complex (0.0995 g) and heated to 65 ° C. (solution D).

In a nitrogen stream, solution D was added to solution C, and heated to reflux for 2 hours. N, N-diphenylamine (5.66 g) was added to the reaction solution, and the mixture was further heated to reflux for 4 hours. The reaction solution was allowed to cool and added dropwise to ethanol (500 ml) to obtain end-capped crude polymer 3 ′.
Dissolve the end-capped crude polymer 3 ′ in 200 mL of toluene, add 150 mL of dilute hydrochloric acid and stir for 30 minutes, then wash 7 times with 100 mL of water, and add 400 mL of ethanol.
Re-precipitated. The obtained polymer was reprecipitated in acetone, and the precipitated polymer was separated by filtration. The polymer collected by filtration was purified by column chromatography to obtain polymer 3 (1.20 g). In addition, it was as follows when the weight average molecular weight and dispersion degree of the compound were measured.

Weight average molecular weight (Mw) = 98000
Dispersity (Mw / Mn) = 1.66
(Synthesis Example 3: Synthesis of Polymer 4)

4,4′-dibromobiphenyl (2.000 g), p-dibromobenzene (1.51
2 g), 4-sec-butylaniline (2.296 g), compound 2 (1.332 g), aniline (0.3197 g), sodium tert-butoxy (7.885 g), and toluene (35 ml) The interior was sufficiently purged with nitrogen and heated to 65 ° C. (solution A).
On the other hand, tri-t-butylphosphine (0.415 g) was added to a toluene solution (4 ml) of tris (dibenzylideneacetone) dipalladium chloroform complex (0.265 g) and heated to 65 ° C. (solution B).

In a nitrogen stream, solution B was added to solution A and heated to reflux for 1.5 hours. 4,4′-Dibromobiphenyl (2.000 g) and p-dibromobenzene (1.361 g) were added to the reaction solution, and the mixture was heated to reflux for 50 minutes. Further, p-dibromobenzene (0.030 g) was added and reacted for 2 hours.
The reaction solution was allowed to cool, and the reaction solution was dropped into 300 mL of ethanol to crystallize the crude polymer 4.

The obtained crude polymer 4 was dissolved in 200 mL of toluene, bromobenzene (0.805 g) and tert-butoxy sodium (7.885 g) were charged, the inside of the system was sufficiently purged with nitrogen, and the mixture was heated to 65 ° C. ( Solution C).
On the other hand, tri-t-butylphosphine (0.207 g) was added to 6 mL of a toluene solution of tris (dibenzylideneacetone) dipalladium chloroform complex (0.132 g), and heated to 65 ° C. (solution D).

In a nitrogen stream, solution D was added to solution C, and heated to reflux for 2 hours. To this reaction solution, 2.169 g of N, N-diphenylamine was added, and the mixture was further heated under reflux for 4 hours. The reaction solution was allowed to cool and added dropwise to ethanol (500 ml) to obtain end-capped crude polymer 4 ′.
This end-capped crude polymer 4 ′ was dissolved in 400 mL of toluene, and diluted hydrochloric acid 300
After adding 30 mL and stirring for 30 minutes, it was washed 6 times with 200 mL of water and 800 mL of ethanol.
Re-precipitated. The obtained polymer was reprecipitated in acetone, and the precipitated polymer was separated by filtration. The polymer collected by filtration was purified by column chromatography to obtain the desired product (1.38 g). In addition, it was as follows when the weight average molecular weight and dispersion degree of the compound were measured.
Weight average molecular weight (Mw) = 60000
Dispersity (Mw / Mn) = 1.38
<Creation of organic electroluminescence device>

Example 1
An organic electroluminescence device having a layer structure of (anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode) was produced.
An anode is formed by patterning an indium tin oxide (ITO) transparent conductive film on a glass substrate with a thickness of 70 nm (sputtered film, sheet resistance 15 Ω) into a 2 mm-wide stripe by ordinary photolithography technology did. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, then dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.
First, a polymer represented by the following structural formula (H3) (polymer 3 synthesized in Synthesis Example 2, Mw = 98000, dispersity Mw / Mn = 1.66), a polymer represented by structural formula (H5) (Mw = 83000, Mw / Mn = 1.43), a coating solution for forming a hole injection layer containing 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate and ethyl benzoate was prepared. This coating solution was deposited on the anode by spin coating under the following conditions to obtain a 65-nm-thick hole injection layer. The polymer represented by the structural formula (H5) was synthesized by the method described in JP-A 2010-155985.

<Coating liquid for hole injection layer formation>
Solvent Ethyl benzoate Coating solution concentration H3: 3.0% by weight
H5: 1.0% by weight
A1: 0.8% by weight
<Film formation conditions for hole injection layer>
Spinner speed 2700rpm
Spinner rotation time 30 seconds Spin coat atmosphere In-air heating condition In-air 230 ° C. 1 hour Subsequently, hole transport containing a polymer represented by the following formula (H6) (weight average molecular weight: 75000, dispersity: 1.52) A layer-forming coating solution was prepared, formed into a film by spin coating under the following conditions, and polymerized by heating to form a 20 nm-thick hole transport layer.
The polymer H6 was synthesized according to the method described in WO2011 / 099531.

<Coating liquid for hole transport layer formation>
Solvent Cyclohexylbenzene Coating solution concentration 1.4% by weight
<Hole transport layer deposition conditions>
Spinner speed 1800rpm
Spinner rotation time 30 seconds Spin coat atmosphere In-air heating condition In-air 230 ° C. 1 hour On the hole transport layer, a compound EM-1 having the following structure was formed as a light-emitting layer to a film thickness of 60 nm by a vacuum deposition method. .

After that, by vacuum deposition, lithium fluoride (LiF) as an electron injection layer has a thickness of 0.5 nm, and aluminum as a cathode has a thickness of 80 nm. Were stacked in a 2 mm wide stripe. As described above, an organic electroluminescent element having a light emitting area portion having a size of 2 mm × 2 mm was obtained.
From this device, green light emission was observed for the 530nm from EM-1 which is a material of the light-emitting layer and the emission maximum, the current density at the time of 4V is applied 4.03mA / cm ^2, the luminance is 180 cd ^{/ m} 2, The current efficiency was 4.45 cd / A.

(Example 2)
In Example 1, instead of (H3), the polymer represented by the following structural formula (H4) (polymer 4 synthesized in Synthesis Example 3, Mw = 60000, dispersity Mw) instead of (H3) in the coating solution for forming the hole injection layer A device was fabricated in the same manner as in Example 1 except that /Mn=1.38) was used.

From this element, green light emission having a light emission maximum of 530 nm derived from EM-1 which is the material of the light emitting layer was observed, the current density when applying 4V was 3.81 mA / cm ² , the luminance was 173 cd / m ² , The current efficiency was 4.54 cd / A.

(Example 3)
A device having a layer structure of (anode / hole injection layer / hole transport layer / cathode) was produced.
An anode is formed by patterning an indium tin oxide (ITO) transparent conductive film on a glass substrate with a thickness of 70 nm (sputtered film, sheet resistance 15 Ω) into a 2 mm-wide stripe by ordinary photolithography technology did. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, then dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

  First, a polymer represented by the following structural formula (H1) (Polymer 1 of Synthesis Example 1, Mw = 52000, Mw / Mn = 1.53), 4-isopropyl-4′-methyldiphenyl represented by the structural formula (A1) A coating solution for forming a hole injection layer containing iodonium tetrakis (pentafluorophenyl) borate and ethyl benzoate was prepared. This coating solution was formed on the anode by spin coating under the following conditions to obtain a 60 nm-thick hole injection layer.

<Coating liquid for hole injection layer formation>
Solvent Ethyl benzoate Coating solution concentration H1: 4.0% by weight
A1: 0.8% by weight
<Film formation conditions for hole injection layer>
Spinner speed 2700rpm
Spinner rotation time 30 seconds Spin coat atmosphere In-air heating condition In-air 230 ° C. 1 hour Subsequently, hole transport containing a polymer represented by the following formula (H6) (weight average molecular weight: 59000, dispersity: 1.55) A layer forming coating solution was prepared, formed into a film by spin coating under the following conditions, and polymerized by heating to form a hole transport layer.

<Coating liquid for hole transport layer formation>
Solvent Cyclohexylbenzene Coating solution concentration 1.4% by weight
<Hole transport layer deposition conditions>
Spinner speed 1500rpm
Spinner rotation time 30 seconds Spin coating atmosphere In-air heating condition In-air 230 ° C. 1 hour After that, by vacuum evaporation, aluminum is used as the cathode to have a film thickness of 80 nm. Laminated in stripes. As described above, an element having a current-carrying portion having a size of 2 mm × 2 mm was obtained. In the current-voltage measurement of this device, the voltage reaching the current density of 100 mA / cm ^{2 and} the current density when 3.5 V is applied are summarized in Table 1.

(Comparative Example 1)
In Example 3, instead of the polymer (H1) in the coating solution for forming the hole injection layer, (H2) (polymer 2 synthesized in Reference Synthesis Example 1, Mw = 59000, Mw / Mn = 1.73) weight average A device was fabricated in the same manner as in Example 3 except that molecular weight: 73000 and dispersity: 2.0) were used.

Current of the device of this - in the voltage measurement, the voltage reaches a current density of 100 mA / cm ^2, the current density at the time of 3.5V applied are summarized in Table 1.

As shown in Table 1, the device produced using the polymer of the present invention has a low voltage and a large current density, and it can be seen that the polymer of the present invention has a large hole injecting and transporting ability.
Therefore, an element formed using the polymer of the present invention is considered to have a low driving voltage.

1 Substrate
2 Anode
3 Hole injection layer
4 hole transport layer
5 Light emitting layer
6 Hole blocking layer
7 Electron transport layer
8 Electron injection layer
9 Cathode

Claims (15)

At least a repeating unit represented by the following formulas (I-1), (I-2), (I-3), (II-1), (II-2), and (II-3), Coalescence.

(In the above formula, R ¹ represents a group containing a crosslinkable group selected from the following crosslinkable group group T. R ²
, R ³ are different from each other and may have a hydrogen atom, an alkyl group which may have a substituent, an aromatic hydrocarbon ring group which may have a substituent, or a substituent. An aromatic heterocyclic group is shown. )
<Crosslinkable group T>

(In the above Kishiki, R ²¹ to R ²³ each independently represent a hydrogen atom or may have a substituent represents an alkyl group .Ar ²¹ is an aromatic hydrocarbon which may have a substituent An aromatic heterocyclic group which may have a ring group or a substituent is shown, and the benzocyclobutene ring may have a substituent. The polymer according to claim 1, wherein the formulas (II-1), (II-2) and (II-3) are the following formulas (III-1), (III-2) and (III-3).

(R ¹ , R ² and R ³ are synonymous with the formulas (II-1), (II-2) and (II-3).) The polymer according to claim 1, wherein the formulas (II-1), (II-2) and (II-3) are the following formulas (IV-1), (IV-2) and (IV-3).

(Note that R ¹ , R ² and R ^{3 have the same} meanings as in formulas ( II- 1), ( II- 2) and ( II- 3).)   A repeating unit selected from the formulas (I-1), (I-2) and (I-3) and a repeating unit selected from the formulas (II-1), (II-2) and (II-3) Are alternately arranged, The polymer according to any one of claims 1 to 3.   A repeating unit selected from the formulas (I-1), (I-2) and (I-3) and a repeating unit selected from the formulas (II-1), (II-2) and (II-3) These are the polymers as described in any one of Claims 1-3 currently arranged at random.   A repeating unit selected from the formulas (I-1), (I-2) and (I-3) and a repeating unit selected from the formulas (II-1), (II-2) and (II-3) The ratio according to claim 1 is 2: 1 to 1: 2. The polymer according to any one of claims 1 to 5. The polymer according to any one of claims 1 to 6, wherein R ² is a hydrogen atom, and R ³ is an alkyl group.   Organic electroluminescent element material containing the polymer as described in any one of Claims 1-7.   The composition for organic electroluminescent elements containing the polymer as described in any one of Claims 1-7.   The composition for organic electroluminescent elements according to claim 9, further comprising an electron accepting compound. In a method for producing an organic electroluminescent device having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate,
A method for producing an organic electroluminescent element, wherein the organic layer is formed by a wet film forming method using the composition for an organic electroluminescent element according to claim 9 or 10. The manufacturing method of the organic electroluminescent element of Claim 11 whose said organic layer is a positive hole injection layer and / or a positive hole transport layer. The method of manufacturing an organic electroluminescent element according to claim 11, wherein the organic layer is a hole injection layer and / or a hole transport layer and a light emitting layer. An organic EL display device manufactured by the method according to claim 11 , wherein the organic EL display device is manufactured . The manufacturing method of organic electroluminescent illumination characterized by using the organic electroluminescent element manufactured by the method as described in any one of Claims 11-13.

Images