JP2007123257A - Method of manufacturing organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic electroluminescent element capable of simply forming a laminated structure in a short time without selecting materials of an upper and lower layers, in a manufacturing method of an organic electroluminescent element for forming a laminated structure by application. <P>SOLUTION: In manufacturing the organic electroluminescent element having a positive electrode and a negative electrode on a substrate and having, between the positive electrode and the negative electrode, a polymer-containing layer containing a polymer and an oxidizer, the polymer-containing layer is heated to 100°C or above after forming the polymer-containing layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic electroluminescent element. Specifically, the present invention relates to a method of manufacturing a stacked organic electroluminescent device in which a plurality of organic layers are provided between an anode and a cathode.

  Since the announcement of Kodak's stacked organic electroluminescence (electroluminescence) element (hereinafter abbreviated as "EL") using the vacuum deposition method, organic EL displays have been actively developed and are now in practical use. It's getting on.

  In such a stacked organic EL element, a plurality of organic layers (such as a light emitting layer, a hole injection layer, a hole transport layer, and an electron transport layer) are stacked between an anode and a cathode. In many cases, these organic layers are formed by vacuum-depositing organic layer materials such as low molecular weight dyes. However, it is difficult to obtain a thin film that is homogeneous and free of defects by the vacuum deposition method, and it takes a long time to form several organic layers.

  On the other hand, a technique for forming a plurality of organic layers of a stacked organic EL element by a coating method has been reported. For example, in the description in the [Example] section of Patent Document 1, a hole injection / transport layer is formed by applying a polymer type hole injection / transport material or a hole injection / transport material and a polymer binder. From this, a light emitting layer is formed by applying a light emitting material and a polymer binder thereon.

JP-A-4-2096

However, when forming a laminated organic layer by a coating method, there are the following problems.
When the organic layer is formed by a coating method, usually, a material for the organic layer is dissolved in an appropriate solvent to prepare a coating solution, and this coating solution is applied and dried. However, if the same solvent is used for the coating solution for forming the lower layer (the organic layer formed first) and the coating solution for forming the upper layer (the organic layer formed on the lower layer), the upper layer At the time of formation, the lower layer components may be dissolved by the solvent of the upper layer coating solution and mixed with the upper layer. For this reason, there is a problem that the configuration of the organic layers that can be stacked is very limited, or a stacked structure cannot be formed, resulting in an organic EL element with low light emission efficiency.

  Therefore, when producing a stacked organic EL element by a coating method, generally, by producing a lower layer coating solution and an upper layer coating solution using different solvents (for example, an aqueous solvent and an organic solvent), A technique is used to prevent the underlying components from melting out. However, in such a method, since the material and structure of the lower layer are limited due to the necessity of stacking the upper layer, there is a problem that it is difficult to obtain a charge balance of carriers, and an element with a short lifetime is likely to be obtained in continuous driving. .

  The present invention has been made in view of the above-described problems, and its object is to easily manufacture a laminated organic electroluminescent device using a coating method without selecting the material and structure of the organic layer. Another object of the present invention is to provide a method for manufacturing an organic electroluminescent device, which can form a laminated structure in a short time.

  As a result of intensive studies, the inventors have formed an organic layer (polymer-containing layer) containing a polymer and an oxidant, and then heated it at 100 ° C. or higher, thereby reducing the characteristics of the organic electroluminescent device. The present inventors have found that the polymer-containing layer can be insolubilized without causing the organic layer to be easily laminated, and the organic layer thereon can be easily laminated.

  That is, the gist of the present invention is a method for producing an organic electroluminescent device having an anode and a cathode on a substrate and a polymer-containing layer containing a polymer and an oxidizing agent between the anode and the cathode. Then, after the formation of the polymer-containing layer, the polymer-containing layer is heated to 100 ° C. or higher.

  Another object of the present invention is to provide an organic electric field having an anode and a cathode on a substrate, and a polymer-containing layer formed from a composition containing a polymer and an oxidizing agent between the anode and the cathode. A method for producing a light-emitting device, comprising: forming the polymer-containing layer, and heating the polymer-containing layer to 100 ° C. or higher (claim 2).

  Here, after forming the anode and the polymer-containing layer in this order on the substrate, it is preferable to heat the polymer-containing layer to 100 ° C. or higher.

  The polymer-containing layer is preferably heated to 100 ° C. or higher in the presence of oxygen.

  Moreover, it is preferable to further form an organic layer on the polymer-containing layer after heating the polymer-containing layer to 100 ° C. or higher.

  The organic layer is preferably a layer containing at least one of a light emitting material, a hole blocking material, an electron transporting material, and an electron injecting material (Claim 6).

（式（Ｉ）中、
Ａｒ¹及びＡｒ²は各々独立して、置換基を有していてもよい芳香族炭化水素基、又は、置換基を有していてもよい芳香族複素環基を表わす。
Ａｒ³〜Ａｒ⁵は各々独立して、置換基を有していてもよい２価の芳香族炭化水素基、又は、置換基を有していてもよい２価の芳香族複素環基を表わす。
Ｘは、下記の連結基群Ｘ１の中から選ばれる連結基を表わす。）
・連結基群Ｘ１：

（式中、
Ａｒ¹¹〜Ａｒ²⁸は各々独立して、置換基を有していてもよい芳香族炭化水素基又は芳香族複素環基を表わす。
Ｒ³¹及びＲ³²は各々独立して、水素原子又は任意の置換基を表わす。） The polymer contained in the polymer-containing layer preferably has a structure represented by the following formula (I) and has a weight average molecular weight of 1,000 or more and 1,000,000 or less (Claim 7).

(In the formula (I),
Ar ¹ and Ar ² each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.
Ar ^{3 to} Ar ⁵ each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. .
X represents a linking group selected from the following linking group group X1. )
Linking group group X1:

(Where
Ar ^{11 to} Ar ²⁸ each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent.
R ³¹ and R ³² each independently represents a hydrogen atom or an arbitrary substituent. )

（式（II−１）〜（II−３）中、
Ｒ¹¹、Ｒ²¹及びＲ³¹は各々独立に、Ａ¹〜Ａ³と炭素原子で結合する有機基を表わす。
Ｒ¹²、Ｒ²²、Ｒ²³及びＲ³²〜Ｒ³⁴は各々独立に、任意の基を表わす。Ｒ¹¹〜Ｒ³⁴のうち隣接する２以上の基が、互いに結合して環を形成していてもよい。
Ａ¹〜Ａ³は何れも周期表第３周期以降の元素であって、Ａ¹は長周期型周期表の第１７族に属する元素を表わし、Ａ²は長周期型周期表の第１６族に属する元素を表わし、Ａ³は長周期型周期表の第１５族に属する元素を表わす。
Ｚ₁ ^n1-〜Ｚ₃ ^n3-は、各々独立に、対アニオンを表わす。
ｎ１〜ｎ３は各々独立に、対アニオンのイオン価を表わす。） Moreover, it is preferable that the oxidizing agent contained in the polymer-containing layer is at least one compound selected from the group consisting of compounds represented by the following formulas (II-1) to (II-3). .

(In the formulas (II-1) to (II-3),
R ¹¹ , R ²¹ and R ³¹ each independently represents an organic group bonded to A ^{1 to} A ³ via a carbon atom.
R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ each independently represents an arbitrary group. Two or more adjacent groups among R ^{11 to} R ³⁴ may be bonded to each other to form a ring.
A ^{1 to} A ³ are all elements after the third period of the periodic table, A ¹ represents an element belonging to Group 17 of the long-period periodic table, and A ² represents Group 16 of the long-period periodic table. A ³ represents an element belonging to Group 15 of the long-period periodic table.
Z ₁ ^{n1- to} Z ₃ ^n3- each independently represents a counter anion.
n1 to n3 each independently represent the ionic value of the counter anion. )

  According to the present invention, the polymer-containing layer can be insolubilized without degrading the performance of the organic electroluminescent device, and the layers on the polymer-containing layer can be easily laminated. Therefore, the organic electroluminescent element obtained by the production method of the present invention has high luminous efficiency, long life, and high reliability.

  Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following description, and various modifications can be made within the scope of the gist of the present invention.

[I. Manufacturing method of organic electroluminescence device]
The method for producing an organic EL device according to the present invention (hereinafter abbreviated as “manufacturing method of the present invention” as appropriate) has an anode and a cathode on a substrate, and a polymer and an oxidizing agent between the anode and the cathode. A method for producing an organic EL device having a polymer-containing layer, wherein the polymer-containing layer is heated to 100 ° C. or higher after the polymer-containing layer is formed, or an anode and a cathode on a substrate And an organic electroluminescent element having a polymer-containing layer formed from a composition containing a polymer and an oxidant between the anode and the cathode, wherein the polymer-containing layer is formed. Later, the polymer-containing layer is heated to 100 ° C. or higher.

  The polymer-containing layer (hereinafter sometimes referred to as “the polymer-containing layer of the present invention”) formed in the production method of the present invention is present between the anode and the cathode and contains at least a polymer and an oxidizing agent. It is. In addition, the polymer-containing layer formed from the composition containing the polymer and the oxidizing agent may be a layer containing the polymer and the oxidizing agent, and is obtained by the reaction of the compound contained in the composition. The layer containing the compound etc. which are obtained may be sufficient. Hereinafter, a composition containing a polymer and an oxidizing agent is referred to as a “polymer composition”.

  In the stacked organic EL element, [II. Various organic layers (light emitting layer, hole injection layer, hole transport layer, electron transport layer, etc.) are laminated and provided between the anode and the cathode as described in detail in the section of “Organic electroluminescent device”. . The polymer-containing layer of the present invention may be any of these organic layers, but is preferably an organic layer formed at a position close to the anode (or directly on the anode). Specifically, the polymer-containing layer of the present invention is usually formed as a hole injection layer. However, other functions may be provided by adding other materials. Furthermore, a function as a light emitting layer may be provided by adding a light emitting material or the like.

  In this section, the composition of the polymer-containing layer, the formation step and the heating step, and the formation of the organic layer thereon, which are the main features of the production method of the present invention, will be described. On the other hand, the specific configuration and the like of the organic EL element to which the production method of the present invention is applied will be described again (in the column of [II. Organic electroluminescent element] described later).

[I-1. Composition of polymer-containing layer]
<I-1-1. Polymer>
The type of the polymer contained in the polymer-containing layer and the polymer composition of the present invention is not particularly limited, but is preferably a compound having an ionization potential of 4.5 eV to 5.5 eV from the viewpoint of hole transport ability. The ionization potential is defined as the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of a material to the vacuum level, and can be measured directly by photoelectron spectroscopy or electrochemically. It can also be obtained by correcting the participation potential obtained with respect to the reference electrode. In the case of the latter method, for example, when a saturated sweet potato electrode (SCE) is used as a reference electrode, it is expressed by the following formula (“Molecular Semiconductors”, Springer-V
erlag, 1985, pp. 98).
Ionization potential = oxidation potential (vs. SCE) + 4.3 eV

  Examples of the polymer contained in the polymer-containing layer and the polymer composition of the present invention include aromatic amine compounds, phthalocyanine derivatives or porphyrin derivatives, oligothiophene derivatives, and the like. Among these, an aromatic amine compound is preferable from the viewpoint of amorphousness, solubility in a solvent, and transmittance of visible light.

  Among the aromatic amine compounds, an aromatic tertiary amine compound is particularly preferable in the present invention. The aromatic tertiary amine compound referred to in the present invention is a compound having an aromatic tertiary amine structure and includes a compound having a group derived from an aromatic tertiary amine.

  The type of the aromatic tertiary amine compound is not particularly limited, but a polymer compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less is more preferable from the viewpoint of the surface smoothing effect.

  Preferable examples of the aromatic tertiary amine polymer compound include a polymer compound having a repeating unit represented by the following formula (I).

(In the formula (I),
Ar ¹ and Ar ² each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.
Ar ^{3 to} Ar ⁵ each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. .
X represents a linking group selected from the following linking group group X1. )

Linking group group X1:

(In the formula, Ar ^{11 to} Ar ²⁸ each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or an arbitrary substituent. )

As Ar ^{1 to} Ar ⁵ and Ar ^{11 to} Ar ²⁸ , any monovalent or divalent group derived from any aromatic hydrocarbon ring or aromatic heterocyclic ring is applicable. These may be the same or different from each other. Moreover, you may have arbitrary substituents.

  Examples of the aromatic hydrocarbon ring include a 5- or 6-membered monocyclic ring or a 2-5 condensed ring. Specific examples 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 ring include a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. Specific examples include 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, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring , Synoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring and the like.

Ar ^{3 to} Ar ⁵ , Ar ^{11 to} Ar ¹⁵ , Ar ^{17 to} Ar ²⁰ , Ar ^{22 to} Ar ²⁵ , Ar ²⁷ , Ar ²⁸ may be one type or two or more types of aromatic hydrocarbon rings exemplified above. And / or two or more divalent groups derived from an aromatic heterocycle may be linked and used.

The group derived from the aromatic hydrocarbon ring and / or aromatic heterocycle of Ar ^{1 to} Ar ⁵ and Ar ^{11 to} Ar ²⁸ may further have a substituent unless it is contrary to the gist of the present invention. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less. The type of the substituent is not particularly limited, and examples thereof include one or more selected from the following substituent group W.

[Substituent group W]
An alkyl group having usually 1 or more, usually 10 or less, preferably 8 or less, such as a methyl group or an ethyl group; an alkenyl group having usually 2 or more, usually 11 or less, preferably 5 or less, such as a vinyl group An alkynyl group having usually 2 or more, usually 11 or less, preferably 5 or less, such as an ethynyl group; an alkoxy having a carbon number of usually 1 or more, usually 10 or less, preferably 6 or less, such as a methoxy group or an ethoxy group; A group; an aryloxy group such as a phenoxy group, a naphthoxy group, a pyridyloxy group, etc., usually 4 or more, preferably 5 or more, usually 25 or less, preferably 14 or less; a carbon such as a methoxycarbonyl group or an ethoxycarbonyl group An alkoxycarbonyl group having a number of usually 2 or more, usually 11 or less, preferably 7 or less; a dimethylamino group, a diethylamino group or the like, and usually having 2 or more carbon atoms Usually 20 or less, preferably 12 or less dialkylamino group; diphenylamino group, ditolylamino group, N-carbazolyl group, etc., and usually diarylamino having 10 or more carbon atoms, preferably 12 or more, usually 30 or less, preferably 22 or less Group: an arylalkylamino group having 6 or more carbon atoms, preferably 7 or more, usually 25 or less, preferably 17 or less, such as a phenylmethylamino group; an acetyl group, a benzoyl group or the like, and usually having 2 or more carbon atoms, Usually an acyl group of 10 or less, preferably 7 or less; a halogen atom such as a fluorine atom or a chlorine atom; a haloalkyl group having a carbon number of usually 1 or more, usually 8 or less, preferably 4 or less, such as a trifluoromethyl group; An alkylthio group having 1 to 10 carbon atoms, preferably 6 or less, preferably 6 or less; An arylthio group having usually 4 or more, preferably 5 or more, usually 25 or less, preferably 14 or less, such as a ruthio group, a naphthylthio group, or a pyridylthio group; Or more, preferably 3 or more, usually 33 or less, preferably 26 or less silyl group; trimethylsiloxy group, triphenylsiloxy group, etc., the carbon number is usually 2 or more, preferably 3 or more, usually 33 or less, preferably 26 or less. A siloxy group; a cyano group; an aromatic hydrocarbon ring group having usually 6 or more, usually 30 or less, preferably 18 or less, such as a phenyl group or a naphthyl group; a carbon number such as a thienyl group or a pyridyl group. An aromatic heterocyclic group of 3 or more, preferably 4 or more, usually 28 or less, preferably 17 or less.

Ar ¹ and Ar ² are preferably monovalent groups derived from a benzene ring, a naphthalene ring, a phenanthrene ring, a thiophene ring, or a pyridine ring from the viewpoint of the solubility, heat resistance, and hole injection / transport properties of the polymer compound. More preferred are a phenyl group and a naphthyl group.

Ar ^{3 to} Ar ⁵ are preferably divalent groups derived from a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring from the viewpoint of heat resistance and hole injection / transport properties including redox potential. More preferably a group, a biphenylene group, or a naphthylene group.

As R ¹ and R ² , a hydrogen atom or an arbitrary substituent is applicable. These may be the same or different from each other. The type of the substituent is not particularly limited as long as it is not contrary to the gist of the present invention. However, if applicable substituents are exemplified, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a silyl group, a siloxy group, an aromatic group A hydrocarbon group and an aromatic heterocyclic group are mentioned. Specific examples thereof include the groups exemplified above in the substituent group W.

  Among the polymer compounds having a repeating unit represented by the formula (I), a polymer compound having a repeating unit represented by the following formula (I ′) is particularly preferable because the hole injection / transport property is very high. .

In formula (I ′), R ^{41 to} R ⁴⁵ each independently represents an arbitrary substituent. Specific examples of the substituents of R ^{41 to} R ⁴⁵ are the same as the substituents that Ar ^{1 to} Ar ⁵ of formula (I) may have (that is, the substituents described in [Substituent group W]). It is. p and q each independently represent an integer of 0 or more and 5 or less. r, s, and t each independently represent an integer of 0 or more and 4 or less.

Y ′ represents a linking group selected from the following linking group group Y2.

In the above formulas, Ar ^{31 to} Ar ³⁷ each independently represents a monovalent or divalent group derived from an aromatic hydrocarbon ring or aromatic heterocycle which may have a substituent. Specific examples of Ar ^{31 to} Ar ³⁷ are the same as Ar ^{1 to} Ar ⁵ described above. Moreover, the substituent which may have is the same as said Ar < ¹ > -Ar < ⁵ >.

  Hereinafter, preferred specific examples of the repeating unit represented by the formula (I) and the formula (I ′) that can be applied in the present invention will be given, but the present invention is not limited to these.

  Among the above specific examples, (P-1) to (P-11), (P-13) to (P-18), (P-20), (P) are more preferable in terms of heat resistance and charge transportability. P-21), (P-23), (P-25), and (P-26) repeating units, more preferably (P-1), (P-3), (P-4), It is a repeating unit of (P-6), (P-9), and (P-10).

  Preferable examples of other aromatic tertiary amine polymer compounds include polymer compounds containing a repeating unit represented by the following formula (III-1) and / or formula (III-2).

(In the formulas (III-1) and (III-2), Ar ⁴⁵ , Ar ⁴⁷ and Ar ⁴⁸ each independently have an aromatic hydrocarbon group which may have a substituent, or a substituent. Ar ⁴⁴ and Ar ⁴⁶ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, or may have a substituent. And represents a good divalent aromatic heterocyclic group, R ^{41 to} R ⁴³ each independently represents a hydrogen atom or an arbitrary substituent.)

Specific examples of Ar ⁴⁵ , Ar ⁴⁷ , Ar ⁴⁸ and Ar ⁴⁴ , Ar ⁴⁶ , preferred examples, examples of substituents that may be included, and examples of preferred substituents are Ar ²¹ , Ar ²² and Ar ²³ to Ar respectively. Same as Ar ²⁵ . R ^{41 to} R ⁴³ are preferably a hydrogen atom or a substituent described in [Substituent group W], more preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group, an aromatic hydrocarbon group, It is an aromatic hydrocarbon group.

  Although the preferable specific example of the repeating unit represented by Formula (III-1) and (III-2) applicable in this invention is given to the following, this invention is not limited to these.

  Preferable examples of the aromatic amine polymer compound applicable in the present invention include polymer compounds having the following repeating units. However, the present invention is not limited to these examples.

  The aromatic tertiary amine polymer compound contained in the polymer-containing layer and the polymer composition of the present invention may be a homopolymer consisting of any one of the various repeating units described above, The copolymer containing 2 or more types by arbitrary combinations and a ratio may be sufficient. In the latter case, the form of the copolymer may be block copolymerization or random copolymerization.

  In addition, the polymer-containing layer and the polymer composition of the present invention may contain only one of the various polymers including the aromatic tertiary amine polymer compound described above, and two kinds thereof. You may contain the above by arbitrary combinations and ratios.

  The ratio of the polymer contained in the polymer-containing layer of the present invention is a value by weight ratio with respect to the whole polymer-containing layer, and is usually 10% by weight or more, preferably 30% by weight or more, and usually 99.9% by weight or less, preferably Is 99% by weight or less. When two or more kinds of polymers are used in combination, the total content thereof is included in the above range.

<I-1-2. Oxidizing agent>
The kind of oxidizing agent contained in the polymer-containing layer and the polymer composition of the present invention is not particularly limited. Examples include onium salts substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pendafluorophenyl) borate and triphenylsulfonium tetrafluoroborate; iron (III) chloride (Japanese Patent Laid-Open No. 11-251067). No.), high-valent inorganic compounds such as ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris (pendafluorophenyl) borane (JP-A-2003-31365); fullerene derivatives; Examples include iodine. Among the above compounds, an onium salt substituted with an organic group is preferable in terms of having strong oxidizing power, and an inorganic compound having a high valence is preferable, and an onium salt substituted with an organic group in terms of being soluble in various solvents, A cyano compound and an aromatic boron compound are preferable. From the viewpoint of achieving both strong oxidizing power and high solubility, an onium salt substituted with an organic group is most preferable, and a compound represented by the following formulas (II-1) to (II-3) is particularly preferable.

In the above formulas (II-1) to (II-3), R ¹¹ , R ²¹ and R ³¹ each independently represents an organic group bonded to A ^{1 to} A ³ via a carbon atom. R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ each independently represents an arbitrary group. Two or more adjacent groups among R ^{11 to} R ³⁴ may be bonded to each other to form a ring.
A ^{1 to} A ³ are all elements after the third period of the periodic table, A ¹ represents an element belonging to Group 17 of the long-period periodic table, and A ² represents Group 16 of the long-period periodic table. A ³ represents an element belonging to Group 15 of the long-period periodic table.
Z ₁ ^{n1- to} Z ₃ ^n3- each independently represents a counter anion.
n1 to n3 each independently represent the ionic value of the counter anion. )

In the above formulas (II-1) to (II-3), R ¹¹ , R ²¹ and R ³¹ each independently represents an organic group bonded to A ^{1 to} A ³ via a carbon atom, and R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ each independently represents an arbitrary substituent. Two or more adjacent groups among R ^{11 to} R ³⁴ may be bonded to each other to form a ring.

The type of R ¹¹ , R ²¹ and R ³¹ is not particularly limited as long as it is an organic group having a carbon atom at the bond portion with A ^{1 to} A ³ unless it is contrary to the gist of the present invention. The molecular weights of R ¹¹ , R ²¹ and R ³¹ are each a value including the substituent, and are usually 1000 or less, preferably 500 or less. Preferred examples of R ¹¹ , R ²¹ and R ³¹ include alkyl groups, alkenyl groups, alkynyl groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups from the viewpoint of delocalizing positive charges. Among them, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferable because it delocalizes positive charges and is thermally stable.

  Examples of the aromatic hydrocarbon group include a monovalent group derived from a 5- or 6-membered monocyclic ring or a 2-5 condensed ring, and a group capable of delocalizing a positive charge on the group. Specific examples thereof include a monovalent group derived from a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluorene ring, and the like. Can be mentioned.

  The aromatic heterocyclic group is a monovalent group derived from a 5- or 6-membered monocyclic ring or a 2-4 condensed ring, and includes a group that can delocalize a positive charge on the group. Specific examples thereof include furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, triazole 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, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline And monovalent groups derived from a ring, an isoquinoline ring, a sinoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, an azulene ring, and the like.

  Examples of the alkyl group include linear, branched, or cyclic alkyl groups having a carbon number of usually 1 or more and usually 12 or less, preferably 6 or less. Specific examples include methyl group, ethyl group, n-propyl group, 2-propyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group and the like.

  Examples of the alkenyl group include those having usually 2 or more, usually 12 or less, preferably 6 or less. Specific examples include a vinyl group, an allyl group, and a 1-butenyl group.

  Examples of the alkynyl group include those having usually 2 or more, usually 12 or less, preferably 6 or less. Specific examples include ethynyl group and propargyl group.

The type of R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ is not particularly limited as long as it is not contrary to the gist of the present invention. The molecular weights of R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ are each a value including the substituent, and are usually 1000 or less, preferably 500 or less. Examples of R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ are alkyl groups, alkenyl groups, alkynyl groups, aromatic hydrocarbon groups, aromatic heterocyclic groups, amino groups, alkoxy groups, aryloxy groups, acyls. Group, alkoxycarbonyl group, aryloxycarbonyl group, alkylcarbonyloxy group, alkylthio group, arylthio group, sulfonyl group, alkylsulfonyl group, arylsulfonyl group, cyano group, hydroxyl group, thiol group, silyl group and the like. Among them, like R ¹¹ , R ^21, and R ³¹ , an organic group having a carbon atom at the bond portion with A ^{1 to} A ³ is preferable from the viewpoint of high electron acceptability. Examples include an alkyl group, an alkenyl group, Alkynyl groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups are preferred. In particular, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferable because it has a large electron accepting property and is thermally stable.

Examples of the alkyl group, alkenyl group, alkynyl group, aromatic hydrocarbon group and aromatic heterocyclic group are the same as those described above for R ¹¹ , R ²¹ and R ³¹ .

  Examples of the amino group include an alkylamino group, an arylamino group, and an acylamino group.

  Examples of the alkylamino group include alkylamino groups having one or more alkyl groups usually having 1 or more carbon atoms and usually 12 or less, preferably 6 or less carbon atoms. Specific examples include methylamino group, dimethylamino group, diethylamino group, dibenzylamino group and the like.

  Examples of the arylamino group include arylamino groups having at least one aromatic hydrocarbon group or aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. It is done. Specific examples include phenylamino group, diphenylamino group, tolylamino group, pyridylamino group, thienylamino group and the like.

  The acylamino group includes an acylamino group having one or more acyl groups having usually 2 or more carbon atoms and usually 25 or less, preferably 15 or less carbon atoms. Specific examples include an acetylamino group and a benzoylamino group.

  The alkoxy group includes an alkoxy group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less. Specific examples include a methoxy group, an ethoxy group, and a butoxy group.

  Examples of the aryloxy group include aryloxy groups having an aromatic hydrocarbon group or an aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. Specific examples include phenyloxy group, naphthyloxy group, pyridyloxy group, thienyloxy group and the like.

  Examples of the acyl group include acyl groups having usually 1 or more carbon atoms and usually 25 or less, preferably 15 or less. Specific examples include formyl group, acetyl group, benzoyl group and the like.

  The alkoxycarbonyl group includes an alkoxycarbonyl group having usually 2 or more carbon atoms and usually 10 or less, preferably 7 or less. Specific examples include a methoxycarbonyl group and an ethoxycarbonyl group.

  Examples of the aryloxycarbonyl group include those having an aromatic hydrocarbon group or an aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. Specific examples include a phenoxycarbonyl group and a pyridyloxycarbonyl group.

  Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having usually 2 or more carbon atoms and usually 10 or less, preferably 7 or less. Specific examples include an acetoxy group and a trifluoroacetoxy group.

  The alkylthio group includes an alkylthio group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less. Specific examples include a methylthio group and an ethylthio group.

  The arylthio group includes an arylthio group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 14 or less. Specific examples include a phenylthio group, a naphthylthio group, and a pyridylthio group.

  Specific examples of the alkylsulfonyl group and the arylsulfonyl group include a mesyl group and a tosyl group.

  Specific examples of the sulfonyloxy group include a mesyloxy group and a tosyloxy group.

  Specific examples of the silyl group include a trimethylsilyl group and a triphenylsilyl group.

As described above, the groups exemplified as R ¹¹ , R ²¹ , R ³¹ , R ¹² , R ²² , R ²³ , and R ^{32 to} R ³⁴ are further substituted with other substituents unless they are contrary to the spirit of the present invention. It may be. The type of the substituent is not particularly limited, and examples thereof include a halogen atom in addition to the groups exemplified as R ¹¹ , R ²¹ , R ³¹ , R ¹² , R ²² , R ²³ , and R ^{32 to} R ³⁴ . A cyano group, a thiocyano group, a nitro group, etc. are mentioned. Among these, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an aromatic hydrocarbon group, and an aromatic heterocyclic group are preferable from the viewpoint of not hindering heat resistance and electron accepting property.

In formulas (II-1) to (II-3), A ^{1 to} A ³ are all elements from the third period (third to sixth periods) of the periodic table, and A ¹ is a long-period type An element belonging to Group 17 of the periodic table is represented, A ² represents an element belonging to Group 16 and A ³ represents an element belonging to Group 15.

Among these, from the viewpoint of electron acceptability and availability, elements before the fifth period (third to fifth periods) of the periodic table are preferable. That is, A ¹ is preferably any ^one of an iodine atom, a bromine atom, and a chlorine atom, A ² is preferably any one of a tellurium atom, a selenium atom, and a sulfur atom, and A ³ is preferably an antimony atom, an arsenic atom, Any of the phosphorus atoms is preferred.

In particular, from the viewpoints of electron acceptability and compound stability, a compound in which A ¹ in formula (II-1) is a bromine atom or an iodine atom, or A ² in formula (II-2) is a selenium atom or a sulfur atom. A compound in which A ¹ in formula (II-1) is an iodine atom is most preferable.

In formulas (II-1) to (II-3), Z ₁ ^{n1- to} Z ₃ ^n3- each independently represents a counter anion. The type of the counter anion is not particularly limited, and may be a monoatomic ion or a complex ion. However, the larger the size of the counter anion, the more the negative charge is delocalized, and the positive charge is also delocalized thereby increasing the electron accepting ability. Therefore, the complex ion is preferable to the monoatomic ion.

n1 to n3 are each independently an arbitrary positive integer corresponding to the ionic value of the counter anion Z ₁ ^{n1 to} Z ₃ ⁿ³⁻ . The values of n1 to n3 are not particularly limited, but all are preferably 1 or 2, and most preferably 1.

Specific examples of Z ₁ ^{n1- to} Z ₃ ^n3- include hydroxide ion, fluoride ion, chloride ion, bromide ion, iodide ion, cyanide ion, nitrate ion, nitrite ion, sulfate ion, sulfite. Ion, perchlorate ion, perbromate ion, periodate ion, chlorate ion, chlorite ion, hypochlorite ion, phosphate ion, phosphite ion, hypophosphite ion, borate ion , Isocyanate ion, hydrosulfide ion, tetrafluoroborate ion, hexafluorophosphate ion, hexachloroantimonate ion; carboxylate ion such as acetate ion, trifluoroacetate ion, benzoate ion; methanesulfonate ion, trifluoro Sulfonate ions such as romethanesulfonate ion; Alkoxy ions such as methoxy ion and t-butoxy ion For example.

In particular, as the counter anions Z ₁ ^{n1 to} Z ₃ ⁿ³ −, complex ions represented by the following formulas (II-4) to (II-6) are preferable from the viewpoint of stability of the compound and solubility in a solvent. In view of the large size, the negative charge is delocalized, and the positive charge is also delocalized to increase the electron accepting ability. Therefore, a complex ion represented by the following formula (II-6) is more preferable.

In formulas (II-4) and (II-6), E ¹ and E ³ each independently represents an element belonging to Group 13 of the long-period periodic table. Of these, a boron atom, an aluminum atom, and a gallium atom are preferable, and a boron atom is preferable from the viewpoint of stability of the compound and ease of synthesis and purification.

In formula (II-5), E ² represents an element belonging to Group 15 of the long-period periodic table. Among these, a phosphorus atom, an arsenic atom and an antimony atom are preferable, and a phosphorus atom is preferable from the viewpoint of stability of the compound, ease of synthesis and purification, and toxicity.

  In the formulas (II-4) and (II-5), X represents a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom, and is a fluorine atom in terms of stability of the compound, ease of synthesis and purification, A chlorine atom is preferred, and a fluorine atom is most preferred.

In formula (II-6), Ar ^{61 to} Ar ⁶⁴ each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group. Examples of the aromatic hydrocarbon group and aromatic heterocyclic group are derived from the same 5- or 6-membered monocyclic ring or 2-4 condensed ring as those exemplified above for R ¹¹ , R ²¹ and R ³¹ . A monovalent group is mentioned. Among these, a monovalent group derived from a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, or an isoquinoline ring is preferable from the viewpoint of stability and heat resistance of the compound.

The aromatic hydrocarbon group and aromatic heterocyclic group exemplified as Ar ^{61 to} Ar ⁶⁴ may be further substituted with another substituent as long as not departing from the gist of the present invention. The type of the substituent is not particularly limited, and any substituent can be applied, but an electron-withdrawing group is preferable.

Examples of preferable electron-withdrawing groups as the substituent that Ar ^{61 to} Ar ⁶⁴ may have include halogen atoms such as fluorine atom, chlorine atom and bromine atom; cyano group; thiocyano group; nitro group; mesyl group Alkylsulfonyl groups such as tosyl group; arylsulfonyl groups such as tosyl group; acyl groups such as formyl group, acetyl group, benzoyl group and the like, usually having 1 or more, usually 12 or less, preferably 6 or less; methoxycarbonyl group, ethoxycarbonyl An alkoxycarbonyl group having 2 or more carbon atoms, usually 10 or less, preferably 7 or less; a phenoxycarbonyl group, a pyridyloxycarbonyl group or the like, and usually having 3 or more carbon atoms, preferably 4 or more and usually 25 or less. An aryloxycarbonyl group having an aromatic hydrocarbon group or an aromatic heterocyclic group of preferably 15 or less; Bonyl group; aminosulfonyl group; trifluoromethyl group, pentafluoroethyl group, etc., a fluorine atom in a linear, branched or cyclic alkyl group having usually 1 or more, usually 10 or less, preferably 6 or less carbon atoms And a haloalkyl group substituted with a halogen atom such as a chlorine atom.

Especially, it is more preferable that at least one group among Ar ^{61 to} Ar ⁶⁴ has one or two or more fluorine atoms or chlorine atoms as substituents. In particular, it is most preferably a perfluoroaryl group in which all of the hydrogen atoms of Ar ^{61 to} Ar ⁶⁴ are substituted with fluorine atoms from the viewpoint of efficiently delocalizing negative charges and having an appropriate sublimation property. preferable. Specific examples of the perfluoroaryl group include a pentafluorophenyl group, a heptafluoro-2-naphthyl group, and a tetrafluoro-4-pyridyl group.

  The molecular weight of the compound is usually 100 or more, preferably 300 or more, more preferably 400 or more, and usually 5000 or less, preferably 3000 or less, more preferably 2000 or less. If the molecular weight of the compound is too small, delocalization of the positive charge and negative charge may be insufficient, so that the electron accepting ability may decrease. If the molecular weight of the compound is too large, the compound itself May interfere with charge transport.

  Specific examples of the compounds represented by formulas (II-4) to (II-6) are given below, but the present invention is not limited to these.

  The polymer-containing layer of the present invention may contain any one of the various oxidizing agents described above alone, or may contain two or more kinds in any combination and ratio. When two or more kinds of oxidizing agents are contained, two or more kinds of oxidizing agents corresponding to any one of the above formulas (II-1) to (II-3) may be combined. Two or more kinds of oxidizing agents corresponding to the above may be combined.

  The content of the oxidizing agent in the polymer-containing layer and the polymer composition of the present invention is a value relative to the polymer and the hole transporting compound described below, and is usually 0.1% by weight or more, preferably 1% by weight or more, and usually 100 % By weight or less, preferably 60% by weight or less, more preferably 50% by weight or less. A larger amount of the oxidizing agent is preferable because it is easily insolubilized, and the heating time can be insolubilized in a short time. In addition, when using together 2 or more types of oxidizing agents, it is made for the total content of these to be contained in the said range.

  In addition, during or after the formation of the polymer-containing layer, the above-described polymer having hole transportability or the compound having the following hole transportability reacts with this oxidizing agent, so that in the polymer-containing layer after film formation. Then, a cation radical and an ionic compound of a polymer having a hole transporting property or a compound having a hole transporting property may be generated.

<I-1-3. Hole-transporting compound>
The polymer-containing layer and polymer composition of the present invention may contain other components in addition to the above-described polymer and oxidizing agent. In particular, most of the polymers described above have a hole transporting property, but may further contain a compound having a hole transporting property (hereinafter sometimes referred to as a “hole transporting compound”). .

  The hole transporting compound can be appropriately selected from various compounds conventionally used as a hole injection / transport thin film purification material in an organic EL device. Among them, those having high solvent solubility are preferable.

  Preferable examples of the hole transporting compound include aromatic amine compounds. Of these, aromatic tertiary amine compounds are particularly preferred. Preferable specific examples of the aromatic tertiary amine compound include binaphthyl compounds represented by the following formula (IV).

In the formula (IV), Ar ^{51 to} Ar ⁵⁸ each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ⁵¹ and Ar ⁵² , Ar ⁵⁵ and Ar ⁵⁶ may be bonded to each other to form a ring. Specific examples, preferred examples of Ar ^{51 to} Ar ⁵⁸ , examples of substituents that may be present, and examples of preferred substituents are the same as those exemplified above for Ar ^{1 to} Ar ⁵ , respectively.

u and v each independently represent an integer of 0 or more and 4 or less. However, u + v ≧ 1. Particularly preferred are u = 1 and v = 1.
Q ¹ and Q ² each independently represents a direct bond or a divalent linking group.

In addition to-(Q ¹ NAr ⁵³ Ar ⁵⁷ (NAr ⁵¹ Ar ⁵² )) and-(Q ² NAr ⁵⁴ Ar ⁵⁸ (NAr ⁵⁵ Ar ⁵⁶ )), the naphthalene ring in formula (IV) has an optional substituent. You may have. Further, these substituents — (Q ¹ NAr ⁵³ Ar ⁵⁷ (NAr ⁵¹ Ar ⁵² ) and — (Q ² NAr ⁵⁴ Ar ⁵⁸ (NAr ⁵⁵ Ar ⁵⁶ )) may be substituted at any position of the naphthalene ring. However, among them, binaphthyl compounds substituted on the 4-position and 4′-position of the naphthalene ring in formula (IV) are more preferred.

  The binaphthylene structure in the compound represented by the formula (IV) preferably has a substituent at the 2,2′-position. As the substituent bonded to the 2,2′-position, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an alkenyl group which may have a substituent, The alkoxycarbonyl group etc. which may have a substituent are mentioned.

  In the compound represented by the formula (IV), the binaphthylene structure may have an arbitrary substituent other than the 2,2′-position. Examples of the substituent include, for example, the 2,2′-position. Examples of the substituent include the groups described above. The compound represented by the formula (IV) has a substituent at the 2-position and the 2'-position, so that the two naphthalene rings are twisted so that the solubility is improved.

  The molecular weight of the binaphthyl compound represented by the formula (IV) is usually 500 or more, preferably 700 or more, and usually 2000 or less, preferably 1200 or less.

  The preferred specific examples of the binaphthyl-based compound represented by the formula (IV) that can be applied in the present invention are shown below, but the present invention is not limited to these.

  Other examples of the aromatic amine compound applicable as the hole transporting compound of the present invention include conventionally known compounds that have been used as a hole injection / transport layer forming material in organic EL devices. For example, an aromatic diamine compound in which a tertiary aromatic amine unit such as 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane is linked (JP 59-194393 A); 4,4′- An aromatic amine containing two or more tertiary amines typified by bis [N- (1-naphthyl) -N-phenylamino] biphenyl and having two or more condensed aromatic rings substituted with nitrogen atoms No. 234681); an aromatic triamine having a starburst structure as a derivative of triphenylbenzene (US Pat. No. 4,923,774); N, N′-diphenyl-N, N′-bis (3-methylphenyl) biphenyl Aromatic diamines such as 4,4′-diamine (US Pat. No. 4,764,625); α, α, α ′, α′-tetramethyl-α, α′-bis (4-di- -Tolylaminophenyl) -p-xylene (Japanese Patent Laid-Open No. 3-269084); a sterically asymmetric triphenylamine derivative as a whole molecule (Japanese Patent Laid-Open No. 4-129271); a plurality of aromatic diamino groups in the pyrenyl group Individually substituted compounds (JP-A-4-175395); aromatic diamines in which tertiary aromatic amine units are linked by ethylene groups (JP-A-4-264189); aromatic diamines having a styryl structure (JP-A-4 No. -290851); Aromatic tertiary amine units linked by a thiophene group (JP-A-4-304466); Starburst type aromatic triamine (JP-A-4-308688); Kaihei 4-364153); a tertiary amine linked by a fluorene group (Japanese Patent Laid-open No. Hei 5-364153) No. 5473); Triamine compounds (JP-A-5-239455); Bisdipyridylaminobiphenyl (JP-A-5-320634); N, N, N-triphenylamine derivatives (JP-A-6-1972) An aromatic diamine having a phenoxazine structure (JP-A-7-138562); a diaminophenylphenanthridine derivative (JP-A-7-252474); a hydrazone compound (JP-A-2-311591); a silazane compound ( U.S. Pat. No. 4,950,950); silanamine derivatives (JP-A-6-49079); phosphamine derivatives (JP-A-6-25659); quinacridone compounds and the like. These aromatic amine compounds may be used in combination of two or more as required.

  Other specific examples of the aromatic amine compound applicable as the hole transporting compound of the present invention include metal complexes of 8-hydroxyquinoline derivatives having a diarylamino group. In the above metal complex, the central metal is alkali metal, alkaline earth metal, Sc, Y, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Al, Ga, In, Si, Ge, Sn , Sm, Eu, Tb, and the ligand 8-hydroxyquinoline has at least one diarylamino group as a substituent, but may have any substituent other than the diarylamino group .

  Preferred specific examples of the phthalocyanine derivative or porphyrin derivative applicable as the hole transporting compound of the present invention include porphyrin, 5,10,15,20-tetraphenyl-21H, 23H-porphyrin, 5,10,15 , 20-tetraphenyl-21H, 23H-porphyrin cobalt (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin copper (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin zinc (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin vanadium (IV) oxide, 5,10,15,20-tetra (4-pyridyl) -21H, 23H-porphyrin 29H, 31H-phthalocyanine copper (II), phthalocyanine zinc (II), lid Cyanine titanium, phthalocyanine oxide magnesium, phthalocyanine lead, phthalocyanine copper (II), 4,4 ', 4' ', 4' '' - tetraaza-29H, 31H-phthalocyanine, and the like.

  In addition, preferable specific examples of the oligothiophene derivative applicable as the hole transporting compound of the present invention include α-sexithiophene.

  The molecular weight of these hole transporting compounds is usually 200 or more, preferably 400 or more, more preferably 600 or more, and usually 5000 or less, preferably 3000 or less, more preferably 2000 or less, and further preferably 1700 or less. Especially preferably, it is the range of 1400 or less. If the molecular weight is too small, the heat resistance tends to be low, whereas if the molecular weight of the hole transporting compound is too large, synthesis and purification tend to be difficult.

  The polymer-containing layer and the polymer composition of the present invention may contain any one of the various hole transporting compounds described above alone, and contain two or more in any combination and ratio. May be.

<I-1-4. Other ingredients>
The polymer-containing layer and the polymer composition contain various components in addition to the above-described polymer and oxidizing agent, and the above-described hole-transporting compound used as necessary, without departing from the spirit of the present invention. May be. Examples of other components include various light emitting materials and electron transport materials. Further, as will be described later, when the polymer-containing layer is formed by using a wet film forming method, a binder resin, a coating property improving agent, or the like that does not trap charges may be added.

[I-2. Formation of polymer-containing layer
In the production method of the present invention, the method for forming the polymer-containing layer is not particularly limited, but a wet film-forming method is preferably used. In this case, the above-described polymer and oxidizing agent, and other components (binder resin, coatability improver, etc.) used as necessary are dissolved in an appropriate solvent to form a coating solution for film formation (polymer composition). To prepare. This coating solution is applied to the layer corresponding to the lower layer of the polymer-containing layer by a technique such as spin coating or dip coating (in the case where the polymer-containing layer is a hole injection layer, usually an anode formed on the substrate). The polymer-containing layer is formed by applying and drying.

  The solvent of the polymer composition is not particularly limited as long as it is a solvent that can dissolve at least the above-described oxidizing agent and polymer. Specifically, the polymer can be dissolved usually at 0.005% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more at normal temperature / normal pressure, and the oxidizing agent is usually 0%. 0.001% by weight or more, preferably 0.1% by weight or more, more preferably 0.2% by weight or more.

  The solvent for the polymer composition is preferably a solvent that does not contain an oxidant and a polymer, a deactivated substance that may deactivate a free carrier (cation radical) resulting from the mixture thereof, or a substance that generates a deactivated substance. .

  Examples of the solvent preferable as the solvent for the polymer composition include ether solvents and ester solvents. Specifically, examples of the ether solvent include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (hereinafter appropriately abbreviated as “PGMEA”) and the like. Aliphatic ether; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole Aromatic ethers and the like. Examples of ester solvents include aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, And aromatic esters such as n-butyl benzoate. Any of these may be used alone, or two or more of these may be used in any combination and ratio.

  Examples of solvents that can be used in addition to the ether solvents and ester solvents described above include aromatic hydrocarbon solvents such as benzene, toluene, and xylene; N, N-dimethylformamide, N, N-dimethylacetamide, and the like. Amide solvents; dimethyl sulfoxide and the like. Any of these may be used alone, or two or more of these may be used in any combination and ratio. Moreover, you may use 1 type, or 2 or more types in these solvents in combination with 1 type or 2 or more types in the above-mentioned ether solvent and ester solvent. In particular, aromatic hydrocarbon solvents such as benzene, toluene and xylene have a low ability to dissolve the oxidizing agent and the polymer, and therefore, it is preferable to use them mixed with ether solvents and ester solvents.

  The concentration of the solvent with respect to the polymer composition is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, and usually 99.999% by weight or less, preferably 99.99% by weight or less, Preferably it is the range of 99.9 weight% or less. In addition, when mixing and using 2 or more types of solvents as a solvent, it is made for the sum total of these solvents to satisfy | fill this range.

  In addition, since an organic EL element is usually formed by laminating layers (organic layers) made of a large number of organic compounds, each layer is required to be a uniform layer. When forming a layer by a wet film forming method, if a certain amount of moisture is present in the composition for forming each layer, moisture is mixed into the coating film and the uniformity of the film is impaired. Is preferably as small as possible. In general, since organic EL elements use many materials such as a cathode that are remarkably deteriorated by moisture, the presence of moisture is preferably as small as possible from the viewpoint of deterioration of the elements. For the above reasons, the amount of water contained in the polymer composition is usually 1% by weight or less, preferably 0.1% by weight or less, and more preferably 0.05% by weight or less.

  Examples of methods for reducing the amount of water in the polymer composition include nitrogen gas sealing, use of a desiccant, dehydration of the solvent in advance, and use of a solvent with low water solubility. Among these, it is preferable to use a solvent having low water solubility from the viewpoint of preventing the phenomenon that the solution coating absorbs moisture in the atmosphere and whitens during the coating process. Specifically, the polymer composition includes a solvent having low water solubility, specifically, a solvent having a water solubility of, for example, 1% by weight or less, preferably 0.1% by weight or less at 25 ° C. It is preferably contained at a concentration of usually 10% by weight or more, especially 30% by weight or more, and particularly 50% by weight or more based on the whole.

  The method for applying and forming the polymer composition by the wet film forming method is not particularly limited, and various known methods such as spin coating, spray coating, dip coating, die coating, flexographic printing, screen printing, and ink jet method are selected. Can be used.

  After application / film formation of the polymer composition, the resulting coating film is dried and the solvent is removed to form a polymer-containing layer. The method for drying is not particularly limited, and examples thereof include heat drying and drying under reduced pressure. Examples of the conditions for the heat drying include conditions such as heating on a hot plate usually at 80 ° C. or higher, preferably 100 ° C. or higher for 1 minute or longer.

  The film thickness of the polymer-containing layer is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[I-3. Heating of polymer-containing layer)
The production method of the present invention is characterized in that after the polymer-containing layer is formed, it is heated to 100 ° C. or higher. This heating may be performed at any time after the formation of the polymer-containing layer (usually after drying of the coating film when the polymer-containing layer is formed by a wet film formation method). Before forming another organic layer on the layer.

  The heating temperature (the maximum temperature of the polymer-containing layer at the time of heating) is usually 100 ° C. or higher as described above, but in order to sufficiently obtain the surface flattening effect and the dehydrating effect by the heat treatment, 150 ° C. or higher is preferable. 180 degreeC or more is further more preferable, and 200 degreeC or more is especially preferable. On the other hand, the upper limit of the heating temperature is usually 350 for the reason that the oxidant contained in the polymer-containing layer of the present invention is decomposed or exceeds the sublimation temperature and the polymer itself is chemically altered. ° C or lower, preferably 300 ° C or lower.

  In addition, since the heating temperature is the temperature of the polymer-containing layer itself as described above, the setting temperature of the heating means described later, the temperature of a layer other than the polymer-containing layer (for example, the substrate or the anode), the polymer-containing layer The temperature of the polymer-containing layer only needs to satisfy the above range regardless of the ambient environmental temperature or the like. The temperature of the polymer-containing layer can be measured using, for example, a surface thermometer or a radiation thermometer.

  The heating time (time during which the polymer-containing layer is heated to 100 ° C. or more) is usually 1 minute or more, preferably 5 minutes or more, more preferably 10 minutes or more, particularly preferably 30 minutes or more, and usually 8 hours or less. , Preferably 6 hours or less, more preferably 4 hours or less. If the heating time is too short, the reaction between the oxidant and the polymer contained in the polymer-containing layer of the present invention and the insolubilization due to the densification of the film may not be ensured. The outermost surface of the polymer-containing layer of the invention may be altered. The polymer-containing layer may be continuously heated to 100 ° C. or higher over the time in the above range, but even when the polymer-containing layer intermittently reaches 100 ° C. or higher, the accumulated time is It only has to satisfy the range. However, in order to ensure insolubilization of the polymer-containing layer, it is preferable that the polymer-containing layer is continuously heated to 100 ° C. or more for as long as possible in the above-mentioned range.

  The product of the above heating temperature and heating time {(heating temperature: ° C) × (heating time: hour)} is usually 1.6 (100 ° C. × 1/60 h) ° C. · h or more, preferably 8.3 (100 ° C. × 5/60 h) ° C. · h or more, more preferably 16.6 (100 × 10/60 h) ° C. · h or more, and usually 2800 (350 ° C. × 8 h) ° C. · h or less, preferably Is 2400 (300 ° C. × 8 h) ° C. · h or less, more preferably 2100 (350 ° C. × 6 h) ° C. · h or less. If the product of the heating temperature and the heating time is too small, as described above, the reaction between the oxidizing agent and the polymer contained in the polymer-containing layer of the present invention and the insolubilization due to the densification of the film cannot be ensured. If the product of the heating temperature and the heating time is too large, this also exceeds the decomposition or sublimation temperature of the oxidizing agent contained in the polymer-containing layer of the present invention, as described above. It may be chemically altered.

  The heating method (heating means and heating method) is not particularly limited. For example, an in-furnace bake method in which a substrate is placed in a heating furnace (baking furnace) to heat a coating film, on a plate (hot plate) A hot plate method in which a substrate is mounted on the substrate and the coating film is heated through the plate, a reduced pressure heating method in which the substrate is placed in a sealable chamber, the inside of the chamber is decompressed, and the coating film is decompressed and heated. There may be mentioned a method in which heaters are disposed on the upper surface side and the lower surface side, and the coating film is heated by irradiating electromagnetic waves (for example, infrared rays) from the heater.

  The heating environment is not particularly limited, but from the viewpoint of reliably insolubilizing the polymer-containing layer, the presence of oxygen is preferable. Specifically, the oxygen concentration is usually 1% or more, preferably 10% or more, more preferably 15% or more, and usually 99% or less, especially 50% or less, and more preferably 30% or less. Of course, an oxygen concentration of about 20%, which is a normal oxygen concentration in the atmosphere, is also preferable.

[I-4. Formation of organic layer
After the formation of the polymer-containing layer and heating, an organic layer is usually formed thereon. The type of the organic layer formed on the polymer-containing layer varies depending on the function of the polymer-containing layer and the laminated structure of the target organic EL device, but the light-emitting material, hole blocking material, electron transport material, hole injection material , A hole transport material, and an electron injection material are preferably a layer containing at least one, and when the polymer-containing layer is a hole injection layer, usually a light emitting layer, a hole transport layer, etc. Is applicable.

  The method for forming the organic layer on the polymer-containing layer is not particularly limited, and an appropriate method may be selected according to the type of the desired organic layer, but the insolubilization of the polymer-containing layer by the production method of the present invention is not limited. From the viewpoint of enjoying the effect, it is preferably formed by a wet film forming method.

  When the organic layer is formed by a wet film forming method, the organic layer material is dissolved in an appropriate solvent to prepare a coating solution, which is formed by coating and drying. The solvent may be appropriately selected according to the material of the organic layer. The specific method of coating and film formation is not particularly limited, and various known methods such as spin coating, spray coating, dip coating, die coating, flexographic printing, screen printing, and ink jet method can be selected and used. is there.

[I-5. Others]
According to the production method of the present invention, the polymer-containing layer can be insolubilized without degrading the performance of the organic EL element, and the organic layer on the polymer-containing layer can be easily laminated. The reason is not clear, but is presumed as follows.

  That is, by heating the polymer-containing layer to 100 ° C. or higher, hydrogen bonded to the aromatic hydrocarbon group or aromatic heterocyclic group in the polymer reacts with oxygen in the environment to undergo dehydration polymerization, It is presumed that the polymer-containing layer is insolubilized. In addition, since the polymer-containing layer is insolubilized, an organic layer on the polymer-containing layer can be easily formed, and the material of the polymer-containing layer and the material of the organic layer on the polymer-containing layer are mixed. Therefore, the characteristics of the organic EL element are not impaired, and as a result, it is presumed that the organic EL element with high luminous efficiency and long life can be provided.

In particular, when a polymer having an aromatic tertiary amine represented by the above formula (I) as a repeating unit is used as a component of a polymer-containing layer together with an oxidizing agent, it is heated to 100 ° C. or higher in the presence of oxygen after the formation of a coating film. In this case, Ar ¹ and Ar ² bonded to the tertiary amine, that is, hydrogen bonded to the optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group reacts with oxygen. Thus, it is presumed that the polymer-containing layer is insolubilized by dehydration polymerization.

[2. Organic electroluminescent device]
An organic EL device manufactured by the manufacturing method of the present invention (hereinafter, abbreviated as “organic EL device of the present invention” as appropriate) has an anode and a cathode on a substrate, and a plurality of organic layers between the anode and the cathode. It has a stacked structure in which layers are stacked. Any one of the plurality of organic layers (preferably the hole injection layer as described above) is formed as the above-described polymer-containing layer (a layer containing at least a polymer and an oxidizing agent).

  FIG. 1 is a cross-sectional view schematically showing an example of the structure of the organic EL element of the present invention. An organic EL element 10a shown in FIG. 1 is configured by laminating an anode 2, a hole injection layer 3, an organic light emitting layer 4, an electron injection layer 5 and a cathode 6 in this order on a substrate 1. In the case of this configuration, the hole injection layer 3 usually corresponds to the above-described polymer-containing layer, and the organic light emitting layer 4 corresponds to an organic layer formed on the polymer-containing layer.

[II-1. substrate〕
The substrate 1 serves as a support for the organic EL element, and a quartz or glass plate, a metal plate or a metal foil, a plastic film, a sheet, or the like is 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 EL element may be deteriorated by outside air that has passed through the substrate. 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.

[II-2. anode〕
The anode 2 plays a role of hole injection into a layer (hole injection layer 3 or organic light emitting layer 4 or the like) on the organic light emitting layer side described later. This anode 2 is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum, a metal oxide such as an oxide of indium and / or tin, a metal halide such as copper iodide, carbon black, or A conductive polymer such as poly (3-methylthiophene), polypyrrole, or polyaniline is used. In general, the anode 2 is often formed by a sputtering method, a vacuum deposition method, or the like. Further, in the case of metal fine particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, and conductive polymer fine powders, they are dispersed in an appropriate binder resin solution and placed on the substrate 1. It is also possible to form the anode 2 by applying to. Further, in the case of a conductive polymer, a thin film can be directly formed on the substrate 1 by electrolytic polymerization, or the anode 2 can be formed by applying a conductive polymer on the substrate 1 (Applied Physics Letters, 1992). Year, Vol. 60, pp. 2711). The anode 2 can also be formed by stacking different materials.

  The thickness of the anode 2 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 opaque, the anode 2 may be the same as the substrate 1. Furthermore, it is also possible to laminate different conductive materials on the anode 2 described above.

  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. A known anode buffer layer may be inserted between the hole injection layer and the anode for the purpose of further improving the efficiency of hole injection and improving the adhesion of the entire organic layer to the anode. .

[II-3. (Hole injection layer)
The hole injection layer 3 is a layer that transports holes from the anode 2 to the organic light emitting layer 4. In the production method of the present invention, the hole injection layer 3 is usually formed as a polymer-containing layer as described above. Therefore, the hole injection layer 3 contains the above-described polymer and oxidizing agent, and preferably contains a hole transporting compound. Details of these components are described in [I-1. As described in the column “Composition of polymer-containing layer”. Furthermore, the hole injection layer 3 may contain other components without departing from the spirit of the present invention.

  Examples of the method for forming the hole injection layer 3 on the anode 2 include a wet film formation method and a vacuum deposition method. As described above, a uniform and defect-free thin film can be easily obtained. The wet film-forming method is preferable from the viewpoint that the time required for the preparation is short. In addition, ITO (indium tin oxide), which is generally used as the anode 2, has a surface roughness (Ra) of about 10 nm in addition to its surface, and often has local protrusions. There was a problem that defects were easily generated. Forming the hole injection layer 3 on the anode 2 by the wet film formation method reduces the occurrence of device defects due to the unevenness of the surface of the anode 2 as compared with the case of forming by the vacuum deposition method. It also has advantages. Details of the method of forming the hole injection layer 3 by the wet film formation method are the same as those described in [I-2. As described in the section “Formation of polymer-containing layer”.

  The thickness of the hole injection layer 3 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

  When the hole injection layer 3 is formed as a polymer-containing layer, as described above, after the hole injection layer 3 is formed, it is heated to 100 ° C. or higher. The details are described in [I-3. This is as described in the section “Heating of polymer-containing layer”.

[II-4. Organic light emitting layer)
An organic light emitting layer 4 is provided on the hole injection layer 3. The organic light emitting layer 4 is excited by recombination of holes injected from the anode 2 through the hole injection layer 3 and electrons injected from the cathode 6 through the electron injection layer 5 between the electrodes to which an electric field is applied. Thus, it is a layer that becomes a main light emitting source.

  The organic light emitting layer 4 contains at least a material having a light emitting property (light emitting material), and preferably has a material having a hole transporting property (hole transporting compound) or an electron transporting property. Material (electron transporting compound). Furthermore, the organic light emitting layer 4 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 the organic light emitting layer 4 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.

  Examples of fluorescent dyes that emit blue light include perylene, pyrene, anthracene, coumarin, p-bis (2-phenylethenyl) benzene, and derivatives thereof. Examples of the green fluorescent dye include quinacridone derivatives and coumarin derivatives. Examples of yellow fluorescent dyes include rubrene and perimidone derivatives. Red fluorescent dyes include DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, etc. Can be mentioned.

  As the phosphorescent material, for example, a long-period type periodic table (hereinafter referred to as a long-period type periodic table when referred to as “periodic table” unless otherwise specified) is selected from the seventh to eleventh groups. And an organometallic complex containing a metal.

  Preferred examples of the metal selected from Groups 7 to 11 of the periodic table contained in the phosphorescent organometallic complex include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Preferred examples of these organometallic complexes include compounds represented by the following formula (V) or formula (VI).

｛式（Ｖ）中、Ｍは金属を表わし、ｑは上記金属の価数を表わす。また、Ｌ及びＬ′は二座配位子を表わす。ｊは０、１又は２の数を表わす。｝

{In Formula (V), M represents a metal, and q represents the valence of the metal. L and L ′ represent bidentate ligands. j represents a number of 0, 1 or 2. }

｛式（VI）中、Ｍ⁷は金属を表わし、Ｔは炭素原子又は窒素原子を表わす。Ｒ⁹²〜Ｒ⁹⁵は、それぞれ独立に置換基を表わす。但し、Ｔが窒素原子の場合は、Ｒ⁹⁴及びＲ⁹⁵は無い。｝

{In Formula (VI), M ⁷ represents a metal, and T represents a carbon atom or a nitrogen atom. R ^{92 to} R ⁹⁵ each independently represents a substituent. However, when T is a nitrogen atom, R ⁹⁴ and R ⁹⁵ are absent. }

  Hereinafter, the compound represented by the formula (V) will be described first.

  In formula (V), M represents an arbitrary metal, and specific examples of preferable ones include the metals described above as metals selected from Groups 7 to 11 of the periodic table.

  In the formula (V), the bidentate ligand L represents a ligand having the following partial structure.

  In the partial structure of L, ring A1 ″ represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent.

  Examples of the aromatic hydrocarbon group include a 5- or 6-membered monocyclic ring or a 2 to 5 condensed ring. Specific examples include monovalent groups derived from 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, etc. Is mentioned.

  Examples of the aromatic heterocyclic group include a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. Specific examples include 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, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring , Sinoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, monovalent group derived from an azulene ring, and the like.

  In the partial structure of L, ring A2 represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.

  Examples of the nitrogen-containing aromatic heterocyclic group include a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. Specific examples include pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, furopyrrole ring, thienofuran ring, benzoisoxazole ring. , Benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone Examples thereof include a monovalent group derived from a ring.

  Examples of the substituent that each ring A1 ″ or ring A2 may have include: a halogen atom such as a fluorine atom; an alkyl group such as a methyl group and an ethyl group; an alkenyl group such as a vinyl group; a methoxycarbonyl group and an ethoxy group Alkoxycarbonyl groups such as carbonyl groups; alkoxy groups such as methoxy groups and ethoxy groups; aryloxy groups such as phenoxy groups and benzyloxy groups; dialkylamino groups such as dimethylamino groups and diethylamino groups; diarylamino groups such as diphenylamino groups Carbazolyl group; acyl group such as acetyl group; haloalkyl group such as trifluoromethyl group; cyano group; aromatic hydrocarbon group such as phenyl group, naphthyl group, phenanthyl group and the like.

  In formula (V), bidentate ligand L ′ represents a ligand having the following partial structure. In the following formulae, “Ph” represents a phenyl group.

Among these, as L ′, the following ligands are preferable from the viewpoint of the stability of the complex.

  More preferred examples of the compound represented by the formula (V) include compounds represented by the following formulas (Va), (Vb), and (Vc).

{In Formula (Va), M ⁴ represents the same metal as M, w represents the valence of the metal, and ring A1 ″ represents an aromatic hydrocarbon group which may have a substituent. Ring A2 represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.}

{In Formula (Vb), M ⁵ represents the same metal as M, w represents the valence of the metal, and ring A1 ″ represents an aromatic hydrocarbon group which may have a substituent or Represents an aromatic heterocyclic group, and ring A2 represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.}

{In the formula (Vc), M ⁶ represents the same metal as M; w represents the valence of the metal; j represents 0, 1 or 2; and ring A1 ″ and ring A1 ′ represent Each independently represents an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group, and ring A2 and ring A2 ′ are each independently a nitrogen-containing optionally substituted group. Represents an aromatic heterocyclic group.}

  In the above formulas (Va), (Vb), (Vc), preferred examples of the ring A1 ″ and the ring A1 ′ include a phenyl group, a biphenyl group, a naphthyl group, an anthryl group, a thienyl group, a furyl group, a benzothienyl group, A benzofuryl group, a pyridyl group, a quinolyl group, an isoquinolyl group, a carbazolyl group, and the like can be given.

  In the above formulas (Va) to (Vc), preferred examples of ring A2 and ring A2 ′ include pyridyl group, pyrimidyl group, pyrazyl group, triazyl group, benzothiazole group, benzoxazole group, benzimidazole group, quinolyl group, An isoquinolyl group, a quinoxalyl group, a phenanthridyl group, and the like can be given.

  Examples of the substituent that the compounds represented by the above formulas (Va) to (Vc) may have include a halogen atom such as a fluorine atom; an alkyl group such as a methyl group and an ethyl group; an alkenyl group such as a vinyl group; Alkoxycarbonyl groups such as carbonyl group and ethoxycarbonyl group; alkoxy groups such as methoxy group and ethoxy group; aryloxy groups such as phenoxy group and benzyloxy group; dialkylamino groups such as dimethylamino group and diethylamino group; diphenylamino group and the like A carbazolyl group; an acyl group such as an acetyl group; a haloalkyl group such as a trifluoromethyl group; a cyano group, and the like.

When the substituent is an alkyl group, the carbon number is usually 1 or more and 6 or less.
When the substituent is an alkenyl group, the carbon number is usually 2 or more and 6 or less.
When the substituent is an alkoxycarbonyl group, the carbon number is usually 2 or more and 6 or less.
When the substituent is an alkoxy group, the carbon number is usually 1 or more and 6 or less.
When the substituent is an aryloxy group, the carbon number is usually 6 or more and 14 or less.
When the substituent is a dialkylamino group, the carbon number is usually 2 or more and 24 or less.
When the substituent is a diarylamino group, the carbon number is usually 12 or more and 28 or less.
When the substituent is an acyl group, the carbon number is usually 1 or more and 14 or less.
When the substituent is a haloalkyl group, the carbon number is usually 1 or more and 12 or less.

  These substituents may be connected to each other to form a ring. As a specific example, a substituent of the ring A1 ″ and a substituent of the ring A2 are bonded, or a substituent of the ring A1 ′ and a substituent of the ring A2 ′ are bonded, One condensed ring may be formed, such as a 7,8-benzoquinoline group.

  Among them, as a substituent for ring A1 ″, ring A1 ′, ring A2 and ring A2 ′, more preferably, an alkyl group, an alkoxy group, an aromatic hydrocarbon group, a cyano group, a halogen atom, a haloalkyl group, a diarylamino group, A carbazolyl group may be mentioned.

Further, preferred examples of M ^{4 to} M ⁶ in the formulas (Va) to (Vc) include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold.

  Specific examples of the organometallic complexes represented by the above formulas (V) and (Va) to (Vc) are shown below. However, the dopant is not limited to the following compounds.

  Among the organometallic complexes represented by the above formula (V), in particular, as the ligand L and / or L ′, a 2-arylpyridine-based ligand, that is, 2-arylpyridine, and an arbitrary substituent is bonded thereto. And compounds having an arbitrary group condensed thereto are preferable.

  The compounds described in International Patent Publication No. 2005/019373 can also be used as the light emitting material.

Next, the compound represented by formula (VI) will be described.
In the formula (VI), M ⁷ represents a metal. Specific examples include the metals described above as the metal selected from Groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum or gold is preferable, and divalent metals such as platinum and palladium are particularly preferable.

In the formula (VI), R ⁹² and R ⁹³ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, Represents an alkoxy group, an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group or an aromatic heterocyclic group;

Further, when T is a carbon atom, R ⁹⁴ and R ⁹⁵ each independently represent a substituent represented by the same examples as R ⁹² and R ⁹³ . Further, when T is a nitrogen atom, R ⁹⁴ and R ⁹⁵ are absent.

R ^{92 to} R ⁹⁵ may further have a substituent. When it has a substituent, there is no restriction | limiting in particular in the kind, Arbitrary groups can be made into a substituent.

Further, any two or more groups of R ^{92 to} R ⁹⁵ may be connected to each other to form a ring.

  Specific examples (T-1, T-10 to T-15) of the organometallic complex represented by the formula (VI) are shown below. However, the dopant is not limited to the following examples. In the following chemical formulae, Me represents a methyl group, and Et represents an ethyl group.

  In the present invention, the molecular weight of the compound used as the light emitting material 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 200 or more, more preferably 300 or more. More preferably, the range is 400 or more. If the molecular weight is too small, the heat resistance may be significantly reduced, gas may be generated, the film quality may be deteriorated when the film is formed, or the morphology of the organic electroluminescent element may be changed due to migration, etc. There is a case. If the molecular weight is too large, purification of the organic compound tends to be difficult, or it may take time to dissolve in the material.

  In addition, the polymer compound and polymer composition of the present invention may contain any one of the various light-emitting materials described above, and have two or more in any combination and ratio. It may be.

  Examples of the low molecular weight hole transporting compound include the aforementioned <I-1-3. 2 or more tertiary amines typified by 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl in addition to the various compounds exemplified in the column “Hole Transporting Compound>” An aromatic diamine having two or more condensed aromatic rings substituted with a nitrogen atom (Japanese Patent Laid-Open No. 5-234681), 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine, etc. Aromatic amine compounds having a starburst structure (Journal of Luminescence, 1997, Vol.72-74, pp.985), aromatic amine compounds consisting of tetramers of triphenylamine (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) and the like. It is done.

  Examples of low molecular weight electron transport compounds 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), 4,4′-bis (9-carbazole) ) -Biphenyl (CBP) and the like.

  Examples of the formation of the organic light emitting layer 4 include a wet film forming method and a vacuum evaporation method. As described above, a homogeneous and defect-free thin film can be easily obtained, and a time for forming can be shortened. Furthermore, a wet film-forming method is preferable from the viewpoint that the effect of insolubilization of the hole injection layer 3 (polymer-containing layer) by the production method of the present invention can be enjoyed. When the organic light emitting layer 4 is formed by a wet film forming method, the above-described materials are dissolved in an appropriate solvent to prepare a coating solution, and the hole injection layer 3 (polymer-containing layer) after the above formation and heating is prepared. It is formed by coating and forming a film on the substrate and drying to remove the solvent. The details are given in [I-2. The contents are basically the same as those described in the section “Formation of polymer-containing layer”.

  The film thickness of the organic light emitting layer 4 is usually 3 nm or more, preferably 5 nm or more, and usually 200 nm or less, preferably 100 nm or less.

[II-5. Electron injection layer
The electron injection layer 5 plays a role of efficiently injecting electrons injected from the cathode 6 into the organic light emitting layer 4. In order to perform electron injection efficiently, the material for forming the electron injection layer 5 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 5 is formed by laminating on the organic light emitting layer 4 by a wet film formation method or a vacuum deposition method. The details of the wet film forming method are the same as those of the hole injection layer 3 and the organic light emitting layer 4. On the other hand, in the case of the vacuum deposition method, a deposition source is put in a crucible or a metal boat installed in a vacuum vessel, and the inside of the vacuum vessel is evacuated to about 10 ⁻⁴ Pa by an appropriate vacuum pump, and then the crucible or metal. The boat is heated and evaporated to form an electron injection layer 5 on the organic light emitting layer 4 on the substrate placed facing the crucible or metal boat.

The alkali metal 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 co-depositing an organic electron transport material and an alkali metal, after placing the organic electron transport material in a crucible installed in a vacuum vessel and evacuating the vacuum vessel 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.

[II-6. cathode〕
The cathode 6 plays a role of injecting electrons into a layer (such as the electron injection layer 5 or the organic light emitting layer 4) on the organic light emitting layer side. As the material of the cathode 6, the material used for the anode 2 can be used. However, in order to perform electron injection efficiently, a metal having a low work function is preferable, and tin, magnesium, indium, calcium, A suitable metal such as aluminum or 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 film thickness of the cathode 6 is usually the same as that of the anode 2. 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. The thickness of the cathode 6 is the same as that of the anode 2.

[II-7. Others]
As described above, the organic EL element having the layer configuration shown in FIG. 1 has been mainly described. However, the organic EL 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 2 and the cathode 6 in addition to the layers described above, and an arbitrary layer may be omitted. .

  FIG. 2 is a cross-sectional view schematically showing another example of the structure of the organic EL element of the present invention. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. An organic EL element 10b shown in FIG. 2 has a hole transport layer 7 between the hole injection layer 3 and the organic light emitting layer 4 in addition to the same configuration as the organic EL element 10a of FIG. In the case of this configuration, the hole transport layer 7 corresponds to an organic layer formed on the polymer-containing layer (hole injection layer 3).

  Examples of the hole transport material for forming the hole transport layer 7 include the same compounds as those exemplified as the hole transport material that may be used in the polymer-containing layer. In addition, polymer materials such as polyarylene ether sulfone containing polyvinyl carbazole, polyvinyl triphenylamine, and tetraphenylbenzidine can be given. The hole transport layer 7 is formed by laminating these hole transport materials on the hole injection layer 3 by a wet film formation method or a vacuum deposition method. The film thickness of the hole transport layer 7 thus formed is usually 10 nm or more, preferably 30 nm. However, it is usually 300 nm or less, preferably 100 nm or less.

  FIG. 3 is a cross-sectional view schematically showing another example of the structure of the organic EL element of the present invention. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. The organic EL element 10c shown in FIG. 3 has an electron blocking layer 8 between the hole injection layer 3 and the organic light emitting layer 4 in addition to the same configuration as the organic EL element 10a shown in FIG. In the case of this configuration, the electron blocking layer 8 corresponds to an organic layer formed on the polymer-containing layer (hole injection layer 3).

  The electron blocking layer 8 is generated by increasing the probability of recombination with holes in the organic light emitting layer 4 by preventing electrons moving from the organic light emitting layer 4 from reaching the hole injection layer 3. There is a role of confining excitons in the light emitting layer 4 and a role of efficiently transporting holes injected from the hole injection layer 3 in the direction of the organic light emitting layer 4. This is particularly effective when a phosphorescent material or a blue light emitting material is used as the light emitting substance. The characteristics required for the electron blocking layer 7 include high hole transportability, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1). Furthermore, in the present invention, since the organic light emitting layer 4 is manufactured by a wet film forming method, it is easy to manufacture. Therefore, the electron blocking layer 7 is also required to have wet film forming compatibility. Examples of the material used for the electron blocking layer 7 include a copolymer of dioctylfluorene and triphenylamine typified by F8-TFB (described in International Publication No. 2004/084260).

  The electron blocking layer 8 can be formed by using a wet film forming method as in the case of the hole injection layer 3 and the organic light emitting layer 4, but is usually formed by a vacuum deposition method. Details of the procedure of the vacuum deposition method are the same as those of the electron injection layer 5.

  As described above, in addition to the configurations described with reference to FIGS. 1 to 3, various modifications can be considered as the configuration of the organic EL element of the present invention.

For example, an electron transport layer may be provided between the organic light emitting layer 4 and the electron injection layer 5.
The electron transport layer is provided for the purpose of further improving the light emitting efficiency of the device, and efficiently transports electrons injected from the cathode 6 between the electrodes to which an electric field is applied in the direction of the organic light emitting layer 4. Formed from a compound capable of

  The electron transporting compound used in the electron transporting layer is a compound that has high electron injection efficiency from the cathode 6 or the electron injection layer 5 and has high electron mobility and can efficiently transport injected electrons. It is necessary to be. 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 derivative, silole derivative, 3- or 5-hydroxyflavone metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compound (JP-A-6-207169) Publication), phenanthroline derivative (Japanese Patent Laid-Open No. 5-331459), 2-t-butyl-9,10-N, N′-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, Examples include n-type zinc selenide.

Similarly to the hole injection layer 3 and the organic light emitting layer 4, the electron transport layer can also be formed by a wet film formation method, but is usually formed by a vacuum deposition method. Details of the procedure of the vacuum deposition method are the same as those of the electron injection layer 5.
The film thickness of the electron transport layer is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

For example, a hole blocking layer may be provided between the organic light emitting layer 4 and the electron injection layer 5.
The hole blocking layer is laminated on the organic light emitting layer 4 so as to be in contact with the interface of the organic light emitting layer 4 on the cathode 6 side. 6 and a compound capable of efficiently transporting electrons injected from the cathode 6 toward the organic light emitting layer 4. The physical properties required for the material constituting the hole blocking layer include high electron mobility, low hole mobility, large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). It is expensive.

  As hole blocking materials satisfying such conditions, mixed materials such as bis (2-methyl-8-quinolinolato), (phenolato) aluminum, bis (2-methyl-8-quinolinolato), (triphenylsilanolato) aluminum, etc. Ligand complexes, metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolato) aluminum binuclear metal complexes, and styryl compounds such as distyrylbiphenyl derivatives (JP-A-11-242996), triazole derivatives such as 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (JP-A-7-41759) And phenanthroline derivatives such as bathocuproine (Japanese Patent Laid-Open No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at the 2,4,6-position described in International Publication No. 2005-022962 are also preferable as the hole blocking material.

The hole blocking layer can also be formed by a wet film formation method, as with the hole injection layer 3 and the organic light emitting layer 4, but is usually formed by a vacuum deposition method. Details of the procedure of the vacuum deposition method are the same as those of the electron injection layer 5.
The thickness of the hole blocking layer is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

Further, lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), lithium oxide (Li ₂ O), cesium carbonate (II) (CsCO ₃ ) is provided at the interface between the cathode 6 and the organic light emitting layer 4 or the electron transport layer. It is also an effective method to improve the efficiency of the element (Applied Physics Letters, 1997, Vol. 70, pp. 152; No. 74586; IEEE Transactions on Electron Devices, 1997, Vol. 44, pp. 1245; SID 04 Digest, pp. 154, etc.).

  Moreover, in the layer structure demonstrated above, it is also possible to laminate | stack components other than a board | substrate in reverse order. For example, in the layer configuration of FIG. 1, other components are provided on the substrate 1 in the order of the cathode 6, the electron injection layer 5, the organic light emitting layer 4, the hole injection layer 3, and the anode 2.

  Furthermore, the organic EL element of the present invention can be configured by laminating components other than the substrate between two substrates, at least one of which is transparent.

Further, a structure in which a plurality of components (light emitting units) other than the substrate are stacked in a plurality of layers (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, instead of the interface layer between the steps (between the light emitting units) (when the anode is ITO and the cathode is Al, these two layers), for example, a charge made of vanadium pentoxide (V ₂ O ₅ ) or the like. When a generation layer (Carrier Generation Layer: CGL) is provided, the barrier between the stages is reduced, which is more preferable from the viewpoint of luminous efficiency and driving voltage.

  Furthermore, the organic EL element of the present invention may be configured as a single organic EL element, or may be applied to a configuration in which a plurality of organic EL elements are arranged in an array, and the anode and cathode are X- You may apply to the structure arrange | positioned at Y matrix form.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

[Example 1]
First, 5% by weight of a polymer (weight average molecular mass 29600; glass transition temperature 177 ° C.) having a repeating structure of the above formula (I) (repeating unit represented by the above exemplified formula (P-1)), an oxidizing agent As a solution, 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate 1% by weight was dissolved in ethyl benzoate as a solvent to prepare a coating solution.

  A slide glass substrate (S-0313 manufactured by MATSUNAMI) was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning. The above-mentioned coating solution was apply | coated with the spin coater with respect to the glass substrate after washing | cleaning. The spin coating was performed in the atmosphere, and the environmental conditions were an air temperature of 23 ° C. and a relative humidity of 40%. The rotation speed of the spinner was 1500 rpm, and the spinner time was 30 seconds. After application, the film was dried by heating on a hot plate at 80 ° C. for 1 minute to form a uniform thin film (polymer-containing layer) having a thickness of 100 nm.

  The formed thin film (polymer-containing layer) was heated in an oven atmosphere at 230 ° C. for 180 minutes. After heating, the obtained thin film (polymer-containing layer) was rinsed with chloroform, the film thickness before and after rinsing was measured with a film thickness meter (Tencor P-15), and the decrease in film thickness was expressed in%. The results are shown in Table 1 below. From Table 1, it can be seen that the polymer-containing layer is insolubilized.

[Example 2]
A thin film (polymer-containing layer) was formed in the same procedure as in Example 1. The obtained thin film (polymer-containing layer) was heated in an oven atmosphere at 200 ° C. for 360 minutes, and then rinsed and film thickness was measured in the same procedure as in Example 1. The results are shown in Table 1 below. Table 1 shows that the polymer-containing layer is insolubilized. Compared with [Example 1], a slight decrease in film thickness is observed, but this is probably because the insolubilization reaction is slow when the heating temperature is low.

[Example 3]
Using an indium tin oxide (ITO) transparent conductive film deposited on a glass substrate with a thickness of 120 nm (manufactured by Sanyo Vacuum Co., Ltd., sputtered film), using ordinary photolithography technology and hydrochloric acid etching An anode was formed by patterning in a stripe shape having a width of 2 mm. This anode-formed substrate was cleaned in the order of ultrasonic cleaning with an aqueous surfactant solution, water cleaning with ultrapure water, ultrasonic cleaning with ultrapure water, and water cleaning with ultrapure water, followed by drying with compressed air, and finally UV irradiation. Ozone cleaning was performed.

  2% by weight of a polymer having a repeating structure of the above formula (I) (weight average molecular mass 29600; glass transition temperature 177 ° C.), and 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an oxidizing agent A coating solution was prepared by dissolving 0.4% by weight in ethyl benzoate as a solvent. This coating solution was spin-coated on the anode forming substrate. Spin coating was performed in air. The environmental conditions during spin coating were an air temperature of 23 ° C. and a relative humidity of 40%. The rotation speed of the spinner was 1500 rpm, and the spinner time was 30 seconds. After spin coating, the film was heated and dried on a hot plate at 80 ° C. for 1 minute to form a uniform thin film (polymer-containing layer) having a thickness of 30 nm to be a hole injection layer. This hole injection layer (polymer-containing layer) was heated in an oven atmosphere at 230 ° C. for 180 minutes.

Next, 4,4′-bis (9-carbazole) -biphenyl (CBP), which is a low molecular weight hole transporting compound, and 4,4 ′, which is a low molecular weight hole transporting compound, in a chloroform solvent. -Bis [N- (9-phenanthryl) -N-phenylamino] biphenyl (PPD), phosphorescent material fac tri (2-phenylpyridine) iridium (Ir (tpy) ₃ ), CBP: PPD: Ir ( A coating solution containing tpy) ₃ = 80: 10: 10 at a concentration of 2% by weight in total was prepared. This coating solution was applied by spin coating on the hole injection layer (polymer-containing layer) after the heat treatment. Spin coating was performed in air. The environmental conditions during spin coating were an air temperature of 23 ° C. and a relative humidity of 40%. The spinner speed was 3000 rpm and the spinner time was 60 seconds. After spin coating, a uniform thin film (organic light emitting layer) having a thickness of 100 nm was formed by heating and drying on a hot plate at 80 ° C. for 1 minute.

Next, the substrate on which the above-described organic light emitting layer is formed is placed in a vacuum deposition apparatus, and after roughly exhausting the apparatus with an oil rotary pump, the oil diffusion pump equipped with a liquid nitrogen trap is used. Was evacuated until the degree of vacuum was 2 × 10 ⁻⁶ Torr (about 2.7 × 10 ⁻⁴ Pa) or less. Vapor deposition of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), a low molecular organic material having electron transport properties, placed in a ceramic crucible placed in the apparatus. Was done. The degree of vacuum during the deposition was 1.3 × 10 ⁻⁶ Torr (about 1.7 × 10 ⁻⁴ Pa), and the deposition rate was 0.2 nm / second. As a result, a 20 nm-thick film was formed as an electron transport layer on the organic light-emitting layer.

The sample after vapor deposition is once taken out from the vacuum vapor deposition apparatus to the atmosphere, and a 2 mm wide stripe shadow mask as a mask for cathode vapor deposition is brought into close contact with the element so as to be orthogonal to the ITO stripe of the anode. It was. This is installed in another vacuum deposition apparatus, and the degree of vacuum in the apparatus is 2 × 10 ⁻⁶ Torr (about 2.7 × 10 ⁻⁴ Pa) or less in the same manner as the above-described deposition of the electron transport layer. It exhausted until it became. As a cathode, first, lithium fluoride (LiF) was deposited at a deposition rate of 0.01 nm / second and a degree of vacuum of 7.0 × 10 ⁻⁶ Torr (about 9.3 × 10 ⁻⁴ Pa) using a molybdenum boat. A film having a thickness of 0.5 nm was formed on the light emitting layer. Next, aluminum was similarly heated by a molybdenum boat and deposited at a deposition rate of 0.5 nm / second and at a vacuum degree of 1 × 10 ⁻⁶ Torr (about 1.3 × 10 ⁻⁴ Pa). By forming the layer, a two-layer cathode composed of a lithium fluoride layer and an aluminum layer was produced. The substrate temperature during the above two-layer cathode deposition was kept at room temperature.

By the above procedure, an organic EL element having a light emitting area portion having a size of 2 mm × 2 mm was obtained. Light emitting properties of the organic EL element, high luminance 17000cd / m ^2, the driving voltage at a luminance of 1000 cd / m ² was 10.1 [V].

[Example 4]
Example 4-1 to Example 4-8 were each performed according to the following procedure.
2% by weight of a polymer having a repeating structure of the above formula (I) (weight average molecular mass 29600; glass transition temperature 177 ° C.) and 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate X as an oxidizing agent % By weight (where “X” is the value of “Example 4-1” to “Example 4-8” shown in Table 2 below) is dissolved in ethyl benzoate as a solvent, and polymer composition A product (A1) was produced.

  Next, ultrasonic cleaning with an aqueous surfactant solution is performed on an ITO substrate (manufactured by Sanyo Vacuum Co., Ltd., sputtered film) on which a transparent conductive film of indium tin oxide (ITO) is deposited to a thickness of 120 nm on a glass substrate. After washing in the order of water washing with ultrapure water, ultrasonic washing with ultrapure water, and water washing with ultrapure water, they were dried with compressed air, and finally subjected to ultraviolet ozone cleaning.

  A polymer-containing layer (B1) was formed on the cleaned ITO substrate by spin coating using the polymer composition (A1) described above. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 40%, the spinner rotation speed was 1500 rpm, and the spinner time was 30 seconds. After coating, the substrate was heated and dried on a hot plate at 80 ° C. for 1 minute, and then heated in an oven atmosphere at 230 ° C. for Y (min) (where “Y” is “Example 4-1” shown in Table 2 below). -It is the value of "Example 4-8." Then, the organic device film (B1) was scraped off with a width of about 1 mm, and the film thickness L1 (nm) was measured with a film thickness meter (Tencor P-15).

  After that, this substrate is set on a spinner, and xylene is dropped on the position where the film thickness is measured. After 10 seconds, spin processing is performed at a spinner rotation speed of 1500 rpm and a spinner time of 30 seconds. P-15), the reduced film thickness L1-L2 (nm) after solvent spin treatment was calculated, and the degree of insolubilization was evaluated.

  For Example 4-1 to Example 4-8, the amount X (wt%) of the oxidizing agent (4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate) in the polymer composition, and 230 ° C. Table 2 below shows the time Y (min) heated at, the film thickness L1 before the solvent spin treatment, and the film thickness reduction amount L1-L2 (nm) after the solvent spin treatment.

[Example 5]
Example 5-1 to Example 5-5 were each performed according to the following procedure.
An indium tin oxide (ITO) transparent conductive film deposited on a glass substrate to a thickness of 120 nm (manufactured by Sanyo Vacuum Co., Ltd., sputtered film) using ordinary photolithography technology and hydrochloric acid etching An anode was formed by patterning into a stripe having a width of 2 mm. The patterned ITO substrate is cleaned in the order of ultrasonic cleaning with an aqueous surfactant solution, water cleaning with ultrapure water, ultrasonic cleaning with ultrapure water, and water cleaning with ultrapure water, followed by drying with compressed air, and finally UV irradiation. Ozone cleaning was performed.

  First, 2% by weight of a polymer having a repeating structure represented by the above formula (I) (weight average molecular mass 29600; glass transition temperature 177 ° C.) and 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluoro) as an oxidizing agent Phenyl) borate X wt% (where “X” is the value of “Example 5-1” to “Example 5-5” shown in Table 3 below) is dissolved in ethyl benzoate as a solvent. Then, a coating solution was prepared. It spin-coated on the said glass substrate, and formed the uniform thin film with a film thickness of 30 nm. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 40%, the spinner rotation speed was 1500 rpm, and the spinner time was 30 seconds. After coating, the substrate was heated and dried on a hot plate at 80 ° C. for 1 minute, and then heated in an oven atmosphere at 230 ° C. for Y (min) (where “Y” represents “Example 5-1” shown in Table 3 below). -Values of "Example 5-5"). This polymer layer becomes a hole injection layer.

  Next, 20 mg of a compound represented by the following structural formula (C-1), 20 mg of a compound represented by the following structural formula (C-2), and 2 mg of a compound represented by the following structural formula (C-3) were converted into xylene 2 Dissolved in 0.0 g to prepare a light emitting layer solution. This light emitting layer solution was applied on the above polymer layer by spin coating to a thickness of 80 nm to form a light emitting layer. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 40%, the spinner rotation speed was 1500 rpm, and the spinner time was 60 seconds. After the application, it was heat-dried at 80 ° C. for 1 minute on a hot plate, and then heat-dried at 80 ° C. for 1 hour at a vacuum degree of 0.01 MPa.

Next, the substrate on which the hole injection layer and the light emitting layer were applied and formed was placed in a vacuum deposition apparatus, the apparatus was roughly evacuated by an oil rotary pump, and the degree of vacuum in the apparatus was 2 × 10 ⁻⁶ Torr. The following structural formula (C-4) is exhausted using an oil diffusion pump equipped with a liquid nitrogen trap until the pressure is about 2.7 × 10 ⁻⁴ Pa or less, and placed in a ceramic crucible arranged in the apparatus. The compound represented by was heated for vapor deposition. The degree of vacuum at the time of deposition is 1.3 × 10 ⁻⁶ Torr (about 1.7 × 10 ⁻⁴ Pa), the deposition rate is about 1 mm / sec, and a film with a thickness of 5 nm is laminated on the light emitting layer. A hole blocking layer was formed. Next, vapor deposition was performed by heating Tris (8-hydroxyquinolinato) aluminum (III) placed in a ceramic crucible disposed in the apparatus. The degree of vacuum at the time of deposition is 1.3 × 10 ⁻⁶ Torr (about 1.7 × 10 ⁻⁴ Pa), the deposition rate is about 2 mm / sec, and a 30 nm-thick film is laminated on the hole blocking layer. Thus, an electron transport layer was formed.

Here, the evaporated element is once taken out from the vacuum evaporation apparatus to the atmosphere, and a 2 mm wide stripe shadow mask is brought into close contact with the element so as to be orthogonal to the anode ITO stripe as a mask for cathode evaporation. Then, it was installed in another vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 2 × 10 ⁻⁶ Torr in the same manner as in the organic layer deposition. As a cathode, first, lithium fluoride (LiF) was deposited on the light emitting layer with a film thickness of 0.5 nm at a deposition rate of 0.05 kg / sec and a degree of vacuum of 2.0 × 10 ⁻⁶ Torr using a molybdenum boat. A film was formed. Next, aluminum was similarly heated by a molybdenum boat to form an aluminum layer having a thickness of 80 nm at a deposition rate of 4 Å / sec and a degree of vacuum of 5 × 10 ⁻⁶ Torr to form a cathode. The substrate temperature at the time of vapor deposition of the above two-layer cathode was kept at room temperature. As described above, an organic electroluminescent element having a light emitting area portion having a size of 2 mm × 2 mm was obtained.

Table 3 below shows the voltage and current luminous efficiency when the luminance of the organic electroluminescent elements obtained in Example 5-1 to Example 5-5 was 100 cd / m ² .
In addition, the voltage and current density when the organic electroluminescent elements obtained in Example 5-1 to Example 5-5 were DC driven at an initial luminance of 1000 cd / m ² and the time during which the luminance was reduced to 500 cd / m ^2. Table 4 shows the voltage increase at that time.

[Example 6]
[Example 6-1]
An indium tin oxide (ITO) transparent conductive film deposited on a glass substrate to a thickness of 120 nm (manufactured by Sanyo Vacuum Co., Ltd., sputtered film) using ordinary photolithography technology and hydrochloric acid etching An anode was formed by patterning into a stripe having a width of 2 mm. The patterned ITO substrate is cleaned in the order of ultrasonic cleaning with an aqueous surfactant solution, water cleaning with ultrapure water, ultrasonic cleaning with ultrapure water, and water cleaning with ultrapure water, followed by drying with compressed air, and finally UV irradiation. Ozone cleaning was performed.

  First, 2% by weight of a polymer having a repeating structure represented by the above formula (I) (weight average molecular mass 29600; glass transition temperature 177 ° C.) and 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluoro) as an oxidizing agent 40% by weight of phenyl) borate was dissolved using ethyl benzoate as a solvent to prepare a coating solution for a hole injection layer. This coating solution for hole injection layer was spin-coated on the said glass substrate, and the uniform thin film with a film thickness of 30 nm was formed. Spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 40%, the spinner rotation speed was 1500 rpm, and the spinner time was 30 seconds. After application, the coating was dried on a hot plate at 80 ° C. for 1 minute, and then heated in an oven atmosphere at 230 ° C. for 30 minutes. This polymer layer becomes a hole injection layer.

  Next, 20 mg of the compound represented by the structural formula (C-1), 20 mg of the compound represented by the structural formula (C-2), and 2 mg of the compound represented by the structural formula (C-3) The resulting solution was dissolved in 0.0 g to prepare a light emitting layer coating solution. This light emitting layer coating solution was applied on the polymer layer to a thickness of 60 nm by spin coating to form a light emitting layer. The spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 40%. After the application, it was heated and dried at 80 ° C. for 1 minute on a hot plate, and then heated and dried at 130 ° C. for 1 hour at a vacuum degree of 0.01 MPa.

Next, the substrate on which the hole injection layer and the light emitting layer are applied and formed is placed in a vacuum vapor deposition apparatus, and after roughly evacuating the apparatus with an oil rotary pump, the degree of vacuum in the apparatus is 2 × 10 ⁻⁶ Torr. The compound represented by the following structural formula (C-4), which was evacuated with a cryopump until the pressure became about (2.7 × 10 ⁻⁴ Pa) or less, placed in a ceramic crucible arranged in the apparatus, was heated. The vapor deposition was performed. The degree of vacuum at the time of deposition is 1.3 × 10 ⁻⁶ Torr (about 1.7 × 10 ⁻⁴ Pa), the deposition rate is about 1 mm / sec, and a film with a thickness of 5 nm is laminated on the light emitting layer. A hole blocking layer was formed. Next, vapor deposition was performed by heating Tris (8-hydroxyquinolinato) aluminum (III) placed in a ceramic crucible disposed in the apparatus. The degree of vacuum at the time of deposition is 1.3 × 10 ⁻⁶ Torr (about 1.7 × 10 ⁻⁴ Pa), the deposition rate is about 2 mm / sec, and a 30 nm-thick film is laminated on the hole blocking layer. Thus, an electron transport layer was formed.

Here, the evaporated element is once taken out from the vacuum evaporation apparatus to the atmosphere, and a 2 mm wide stripe shadow mask is brought into close contact with the element so as to be orthogonal to the anode ITO stripe as a mask for cathode evaporation. Then, it was installed in another vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus was 2 × 10 ⁻⁶ Torr (about 2.7 × 10 ⁻⁴ Pa) in the same manner as the organic layer deposition. First, lithium fluoride (LiF) was used as a cathode, using a molybdenum boat, with a deposition rate of 0.05 kg / sec, a vacuum of 2.0 × 10 ⁻⁶ Torr (about 2.7 × 10 ⁻⁴ Pa), and 0 A film having a thickness of 0.5 nm was formed on the light emitting layer. Next, aluminum was similarly heated by a molybdenum boat to form an aluminum layer having a thickness of 80 nm at a deposition rate of 4 liters / second and a degree of vacuum of 5 × 10 ⁻⁶ Torr (about 6.7 × 10 ⁻⁴ Pa). A cathode was formed. The substrate temperature at the time of vapor deposition of the above two-layer cathode was kept at room temperature. As described above, an organic electroluminescent element having a light emitting area portion having a size of 2 mm × 2 mm was obtained.

Table 5 below shows the voltage and current luminous efficiency when the luminance of the organic electroluminescent element obtained in Example 6-1 is 100 cd / m ² .

In addition, the voltage and current density when the organic electroluminescence device obtained in Example 6-1 was DC driven at an initial luminance of 1000 cd / m ² , the time when the luminance was reduced to 500 cd / m ² and the voltage increase at that time were obtained. It is shown in Table 6 below.

[Example 6-2]
2% by weight of a polymer having a repeating structure shown below (weight average molecular mass 26500; glass transition temperature 208 ° C.) and 40% by weight of 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an oxidizing agent The solution was dissolved using ethyl benzoate as a solvent to prepare a coating solution for a hole injection layer. In the following formula, the parentheses represent individual repeating structures, n and m are integers representing the ratio of the corresponding repeating structures, and n: m = 1: 1. Further, the order of bonding of these repeating units is not particularly limited, and may be a block copolymer or a random copolymer.

  An organic electroluminescent element was obtained in the same manner as in Example 6-1 except that the hole injection layer was formed using this hole injection layer coating solution. The characteristics of this element are shown in Tables 5 and 6 below.

[Example 6-3]
2% by weight of a polymer having a repeating structure shown below (weight average molecular mass 28700; glass transition temperature 160 ° C.) and 40% by weight of 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an oxidizing agent The solution was dissolved using ethyl benzoate as a solvent to prepare a coating solution for a hole injection layer. In the following formula, the parentheses represent individual repeating structures, n and m are integers representing the ratio of the corresponding repeating structures, and n: m = 1: 1. Further, the order of bonding of these repeating units is not particularly limited, and may be a block copolymer or a random copolymer.

  An organic electroluminescent element was obtained in the same manner as in Example 6-1 except that the hole injection layer was formed using this hole injection layer coating solution. The characteristics of this element are shown in Tables 5 and 6 below.

[Example 6-4]
2% by weight of a polymer having a repeating structure shown below (weight average molecular mass 21800; glass transition temperature 214 ° C.) and 40% by weight of 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an oxidizing agent The solution was dissolved using ethyl benzoate as a solvent to prepare a coating solution for a hole injection layer. In the following formula, the parentheses represent a repeating structure, and n is an integer representing the number of repetitions of the repeating structure.

  An organic electroluminescent element was obtained in the same manner as in Example 6-1 except that the hole injection layer was formed using this hole injection layer coating solution. The characteristics of this element are shown in Tables 5 and 6 below.

[Example 6-5]
2% by weight of a polymer having a repeating structure shown below (weight average molecular mass: 33000; glass transition temperature: 167 ° C.) and 40% by weight of 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate as an oxidizing agent The solution was dissolved using ethyl benzoate as a solvent to prepare a coating solution for a hole injection layer. In the following formula, the parentheses represent a repeating structure, and n is an integer representing the number of repetitions of the repeating structure.

  An organic electroluminescent element was obtained in the same manner as in Example 6-1 except that the hole injection layer was formed using this hole injection layer coating solution. The characteristics of this element are shown in Tables 5 and 6 below.

  The present invention relates to various fields where an organic EL optical element is used, for example, a light source (for example, a light source of a copying machine, a flat panel display (for example, for an OA computer or a wall-mounted television) or a surface light emitter). It can be suitably used in the fields of liquid crystal displays and backlights of instruments), display panels, indicator lamps and the like.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Organic light emitting layer 5 Electron injection layer 6 Cathode 7 Hole transport layer 8 Electron blocking layers 10a to 10c Organic EL device

Claims (8)

A method for producing an organic electroluminescent device having an anode and a cathode on a substrate and having a polymer-containing layer containing a polymer and an oxidizing agent between the anode and the cathode,
A method for producing an organic electroluminescent device, comprising heating the polymer-containing layer to 100 ° C. or higher after the formation of the polymer-containing layer. A method for producing an organic electroluminescent device having an anode and a cathode on a substrate, and a polymer-containing layer formed from a composition containing a polymer and an oxidizing agent between the anode and the cathode,
A method for producing an organic electroluminescent device, comprising heating the polymer-containing layer to 100 ° C. or higher after the formation of the polymer-containing layer. 3. The organic electroluminescent element according to claim 1, wherein after forming the anode and the polymer-containing layer in this order on the substrate, the polymer-containing layer is heated to 100 ° C. or higher. Production method. The method for producing an organic electroluminescent element according to any one of claims 1 to 3, wherein the polymer-containing layer is heated to 100 ° C or higher in the presence of oxygen. The organic electroluminescence device according to any one of claims 1 to 4, wherein an organic layer is further formed on the polymer-containing layer after the polymer-containing layer is heated to 100 ° C or higher. Method. The organic layer is a layer containing at least one of a light emitting material, a hole blocking material, an electron transport material, and an electron injection material, according to any one of claims 1 to 5. The manufacturing method of an organic electroluminescent element. The polymer contained in the polymer-containing layer has a structure represented by the following formula (I) and has a weight average molecular weight of 1,000 or more and 1,000,000 or less. A method for producing an organic electroluminescent element according to claim 1.

(In the formula (I),
Ar ¹ and Ar ² each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.
Ar ^{3 to} Ar ⁵ each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. .
X represents a linking group selected from the following linking group group X1. )
Linking group group X1:

(Where
Ar ^{11 to} Ar ²⁸ each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or an arbitrary substituent. ) The oxidizing agent contained in the polymer-containing layer is at least one compound selected from the group consisting of compounds represented by the following formulas (II-1) to (II-3). 8. The method for producing an organic electroluminescent element according to any one of 7 above.

(In the formulas (II-1) to (II-3),
R ¹¹ , R ²¹ and R ³¹ each independently represents an organic group bonded to A ^{1 to} A ³ via a carbon atom.
R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ each independently represents an arbitrary group. Two or more adjacent groups among R ^{11 to} R ³⁴ may be bonded to each other to form a ring.
A ^{1 to} A ³ are all elements after the third period of the periodic table, A ¹ represents an element belonging to Group 17 of the long-period periodic table, and A ² represents Group 16 of the long-period periodic table. A ³ represents an element belonging to Group 15 of the long-period periodic table.
Z ₁ ^{n1- to} Z ₃ ^n3- each independently represents a counter anion.
n1 to n3 each independently represent the ionic value of the counter anion. )

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