JP2012089261A - Organic electroluminescent element and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a multilayer coating method in the manufacture of an organic EL element.SOLUTION: In the method of manufacturing an organic electroluminescent element including one or more organic compound layer formed between a pair of electrodes, at least one organic compound layer is formed by two following steps. The first step: a step for applying a composition containing an organic compound A having two or more thiol groups, the second step: a step for heating the composition applied in the first step, and making the organic compounds A react with each other to be insoluble.

Description

  The present invention relates to a method for producing an organic electroluminescent element (hereinafter also referred to as “organic EL element”), an organic EL element obtained by the production method, and an application thereof.

  In recent years, devices utilizing the electroluminescence phenomenon have become more important. As such a device, an electroluminescent element in which a light emitting material is formed in a layer form, a pair of electrodes including an anode and a cathode is provided on the light emitting layer, and light is emitted by applying a voltage attracts attention. Yes. Such an electroluminescent device injects holes and electrons from the anode and the cathode, respectively, by applying a voltage between the anode and the cathode, and the injected electrons and holes are combined in the light emitting layer. It emits light using the energy generated by doing so. In other words, an electroluminescent element is a device that utilizes a phenomenon in which light is generated when a light emitting material of a light emitting layer is excited by energy due to this coupling and returns from an excited state to a ground state again.

  When this electroluminescent element is used as a display device, the light emitting material is self-luminous, and therefore, the response speed as the light emitting material is high and the viewing angle is wide. Further, the structure of the electroluminescent element has an advantage that the display device can be easily reduced in thickness. In addition, an organic electroluminescent element using, for example, an organic substance as a light emitting material can emit light in white and is surface emitting. Therefore, the electroluminescent element can be used by being incorporated in a lighting device. Proposed.

  As described above, the organic EL element usually has an organic layer including an anode, a cathode, and at least a light emitting layer provided between both electrodes on a substrate.

  As the organic layer, in addition to the light emitting layer, a hole injection layer (anode buffer layer), a hole transport layer, a hole blocking layer, an electron transport layer, an electron injection layer, and the like are generally provided. Usually, an organic EL element is constituted by laminating these layers between an anode and a cathode. In recent years, in particular, a method for laminating each organic layer to solve the problem in order to improve luminous efficiency, luminance, and durability has been studied.

  The method for forming the organic layer can be broadly divided into those by vapor deposition (hereinafter also referred to as “vapor deposition method”) and those by coating (hereinafter also referred to as “coating method”).

  The vapor deposition method requires a large facility and is not a simple manufacturing method because its conditions are strictly controlled.

  On the other hand, the coating method is capable of forming an organic layer with relatively simple equipment, and has been developed in recent years because it can be easily applied to the enlargement of elements.

  However, there are various problems in forming an organic layer by a coating method. In particular, when another layer is formed on the formed organic layer by coating, the lower organic layer dissolves in the solvent used for the upper layer coating and the interface with the upper layer is disturbed. In some cases, the lower layer itself elutes and a multilayer structure cannot be formed.

  In order to solve this problem, after forming a layer coated with a compound having a functional group having reactivity such as polymerization, this is reacted so that it does not dissolve in a solvent or the like (hereinafter also referred to as “insolubilization”). .) A method is proposed.

  Patent Document 1 discloses that an organic layer in a coating method can be multilayered by applying a mixed composition of a thiol material and an ene material, then polymerizing the mixture and insolubilizing it in a solvent.

JP 2005-533873 A

  However, this polymerization reaction requires harsh conditions such as irradiation with ultraviolet rays for a long period of time, which is not preferable because it causes deterioration of the material.

  As described above, a sufficient solution method has not yet been found for multilayering in the production of an organic EL element by a coating method.

  An object of this invention is to solve the problem regarding the multilayering by the apply | coating method in manufacture of an organic EL element. Accordingly, an object of the present invention is to provide a method for producing an organic EL element having a very high efficiency light output and a long life, and an element.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

  That is, the present invention relates to the following [1] to [11], for example.

[1]
A method of manufacturing an organic electroluminescence device including one or more organic compound layers formed between a pair of electrodes, wherein at least one organic compound layer is formed by the following two steps: Manufacturing method of electroluminescence element;
1st process: The process of apply | coating the composition containing the organic compound A which has a 2 or more thiol group,
2nd process: The process of heating the composition apply | coated by the 1st process and making the thiol group which the organic compound A has react, and making it insolubilize.

[2]
The method for producing an organic electroluminescent element according to [1], wherein the organic compound A is a hole transporting compound, an electron transporting compound or a light emitting compound.

[3]
The method for producing an organic electroluminescent element according to [1], wherein the organic compound A is a hole transporting compound represented by the following general formula (1).

[In formula (1), at least one of R ² , R ³ , R ⁸ and R ¹³ is a substituent (A1) represented by the following formula (A1),

(In the formula (A1), a plurality of R ^aa are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E):

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), and n
Represents 0, 1 or 2. )
R ^a1 to R ^a10 of R ¹ to R ¹⁵ and in the substituent (A1) not substituted with a substituent (A1) of R ¹ to R ¹⁵ of the backbone structure are each independently a hydrogen atom, a halogen atom , Cyano group,
An amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (1) in total. ]
[4]
The method for producing an organic electroluminescent element according to [1], wherein the organic compound A is a hole transporting compound represented by the following general formula (1).

[In the formula (1), at least one of R ² , R ³ , R ⁸ and R ¹³ is a substituent (B1) represented by the following formula (B1),

(In the formula (B1), a plurality of ^Rbbs are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), p
Represents 0, 1 or 2. )
R ^b1 to R ^b8 of R ¹ to R ¹⁵ and substituents (B1) in which is not substituted with a substituent (B1) of R ¹ to R ¹⁵ of the backbone structure are each independently a hydrogen atom, a halogen atom , A cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thiol-containing group represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (1) in total. ]
[5]
The method for producing an organic electroluminescent element according to [1], wherein the organic compound A is a hole transporting compound represented by the following general formula (2).

[In the formula (2), R ²⁹ is a substituent (C1) represented by the following formula (C1) or a substituent (D1) represented by the following formula (D1),

(In the formula (C1), a plurality of R ^ccs are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), q
Represents 0, 1 or 2. )

(In the formula (D1), a plurality of R ^dds are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), and r
Represents 0, 1 or 2. )
(2-i) when R ²⁹ is a substituent (C1),
R ^{21 to} R ²⁸ in the skeleton structure and R ^c1 in the substituent (C1) are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, 10 alkoxy groups or a thiol-containing group (E) represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (2) in total,
(2-ii) when R ²⁹ is a substituent (D1),
R ^{21 to} R ²⁸ in the skeleton structure and R ^{d1 to} R ^d8 in the substituent (D1) are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, carbon A thiol-containing group (E) represented by the following formula (E):

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (2) in total. ]
[6]
[1] to [5], wherein one or more organic compound layers are further formed on the organic compound layer formed by the first step and the second step by the following two steps. The manufacturing method of the organic electroluminescent element as described in any one.

Third step: A step of applying a composition containing an organic compound having two or more thiol groups, which is different from the organic compound A,
Fourth step: A step of heating the composition applied in the third step to react and insolubilize thiol groups of an organic compound different from the organic compound A.

[7]
The said composition contains an oxidizing agent further, The manufacturing method of the organic electroluminescent element as described in any one of [1]-[6] characterized by the above-mentioned.

[8]
Heating temperature in a 2nd process is 30 to 200 degreeC, The manufacturing method of the organic electroluminescent element as described in any one of [1]-[7] characterized by the above-mentioned.

[9]
The organic electroluminescent element obtained by the manufacturing method as described in any one of [1]-[8].

[10]
A display apparatus provided with the organic electroluminescent element as described in [9].

[11]
A surface-emitting light source comprising the organic electroluminescence element according to [9].

  ADVANTAGE OF THE INVENTION According to this invention, the problem regarding multilayering by the apply | coating method can be solved in manufacture of an organic EL element. As a result, a method for producing an organic EL device having a very high-efficiency light output and a long lifetime, and the device are provided.

FIG. 1 is a cross-sectional view showing an example of an organic EL element in the present invention. FIG. 2 is a cross-sectional view showing an example of the organic EL element in the present invention. FIG. 3 is a cross-sectional view showing an example of the organic EL element in the present invention. FIG. 4 is a diagram schematically showing a method of measuring the thickness of the organic compound layer in the example.

11, 21, 31 ... substrate 12, 22, 32 ... anode 13, 23 ... hole transport layer 14, 24, 34 ... light emitting layer 25 ... electron transport layer 16, 26, 36 ... Cathode

<Method for producing organic EL element>
The method for producing an organic EL device of the present invention is a method for producing an organic EL device comprising one or more organic compound layers formed between a pair of electrodes (specifically, between an anode and a cathode), At least one organic compound layer is formed by the following two steps;
1st process: The process of apply | coating the composition containing the organic compound A which has a 2 or more thiol group,
2nd process: The process of heating the composition apply | coated by the 1st process and making organic compound A react and insolubilize.

[First step]
In the first step, a composition containing an organic compound A having two or more thiol groups is applied.

  The organic compound A contained in the composition has two or more thiol groups in one molecule, and usually has 2 to 6 thiol groups. The organic compound A is preferably a hole transporting compound, an electron transporting compound, or a light emitting compound. In this specification, a compound and a layer composed of all or one or more of a hole transporting compound, an electron transporting compound, and a light emitting compound are referred to as “organic EL compound” and “organic EL compound layer”, respectively. Say. Specifically, the organic EL compound layer is formed using a hole transport layer formed using a hole transport compound, an electron transport layer formed using an electron transport compound, and a light emitting compound. Such as a light emitting layer.

  When the organic compound A is a hole transporting compound, for example, a triarylamine derivative, an N, N, N ′, N′-tetraaryl (biphenyldiamine) derivative, an N, N, N ′, N′— Examples thereof include those in which two or more thiol groups are introduced into a hole transporting compound such as a tetraaryl (terphenyldiamine) derivative, a stilbene arylamine derivative, a carbazole derivative, and an oligothiophene derivative.

  When the organic compound A is an electron transporting compound, for example, a phenylene vinylene derivative, a benzoxazole derivative, an oxadiazole derivative, a thiadiazole derivative, a polyphenylene derivative, a pyridine derivative, a pyrimidine derivative, a triazine derivative, a pyrazone derivative, an azomethine derivative, And those obtained by introducing two or more thiol groups into an electron transporting compound such as a fluorenone derivative, a fluorenylidene derivative, a perylene derivative, or a boron derivative.

  When the organic compound A is a luminescent compound, for example, phenylene vinylene derivative, condensed polycyclic aromatic derivative, quinacridone derivative, stilbene derivative, coumarin derivative, pyran derivative, oxazoline derivative, porphyrin derivative, pyrazine derivative, organometallic complex And luminescent compounds such as perylene derivatives, in which two or more thiol groups are introduced.

  The hole transporting compound may be used alone or in combination of two or more, and the same applies to the electron transporting compound and the light emitting compound.

  Further, two or more of the hole transporting compound, the electron transporting compound and the light emitting compound may be mixed and used. For example, all of the above hole transporting compound, electron transporting compound and light emitting compound may be used.

  In addition, as an organic compound having two or more thiol groups, a compound having two or more functions among hole transporting property, electron transporting property, and light emitting property may be used.

  As the organic compound A, a hole transporting compound having a skeleton structure represented by the following formula (1) or (2) is more preferably used.

  The hole transporting compound (1) having a skeleton structure represented by the following formula (1) is:

In formula (1), at least one of R ² , R ³ , R ⁸ and R ¹³ is a substituent (A1) represented by the following formula (A1), or represented by the following formula (B1). It is a substituent (B1) (however, the hole transporting compound (1) does not have both the substituent (A1) and the substituent (B1)).

(In the formula (A1), a plurality of R ^aa are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E):

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), and n
Represents 0, 1 or 2. )

(In the formula (B1), a plurality of ^Rbbs are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), p
Represents 0, 1 or 2. )
(1-i) First, at least one of R ² , R ³ , R ⁸ and R ¹³ is a substituent (A1).
(Hole transporting compound (1-i)) will be described.

^Examples of the alkyl group in R ^aa in the substituent (A1) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tertiary butyl group, an amyl group, and a hexyl group. From the viewpoint of easy synthesis of the transportable compound (1), a methyl group, an ethyl group, and an isopropyl group are preferable, and a methyl group is particularly preferable.

Regarding the thiol-containing group (E) in R ^aa, examples of the alkylene group include a methylene group, an ethylene group, a propylene group, and a butylene group.

R ^a1 to R ^a10 of R ¹ to R ¹⁵ and in the substituent (A1) not substituted with a substituent (A1) of R ¹ to R ¹⁵ of the backbone structure are each independently a hydrogen atom, a halogen atom , Cyano group,
An amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms).

Examples of the halogen atom in R ^{1 to} R ¹⁵ and R ^{a1 to} R ^a10 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

Examples of the alkyl group in R ^{1 to} R ¹⁵ and R ^{a1 to} R ^a10 include the specific examples of the alkyl group in R ^aa described above. From the viewpoint of ease of synthesis of the hole transporting compound (1), methyl Group, ethyl group and isopropyl group are preferable, and methyl group is particularly preferable.

Examples of the alkoxy group in R ^{1 to} R ¹⁵ and R ^{a1 to} R ^a10 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isopropoxy group, an isobutoxy group, and a tertiary butoxy group. Group, propoxy group and butoxy group are preferable, and methoxy group is particularly preferable.

Regarding the thiol-containing group (E) in R ^{1 to} R ¹⁵ and R ^{a1 to} R ^a10, examples of the alkylene group include specific examples of the alkylene group in the thiol-containing group (E) in R ^aa described above.

  Two or three or more thiol-containing groups (E) are contained in the hole transporting compound (1-i) in total. Thereby, the preferable effect which is mentioned later in the multilayering of an organic compound layer is exhibited.

(1-ii) Next, at least one of R ² , R ³ , R ⁸ and R ¹³ is a substituent (B1
) (Hole transporting compound (1-ii)) will be described.

Examples of the alkyl group for R ^bb in the substituent (B1) include the specific examples of the alkyl group for R ^aa described above. From the viewpoint of ease of synthesis of the hole transporting compound (1), a methyl group, Group, isopropyl group is preferable, and methyl group is particularly preferable.

Regarding the thiol-containing group (E) in R ^bb, examples of the alkylene group include specific examples of the alkylene group in the thiol-containing group (E) in R ^aa described above.

R ^b1 to R ^b8 of R ¹ to R ¹⁵ and substituents (B1) in which is not substituted with a substituent (B1) of R ¹ to R ¹⁵ of the backbone structure are each independently a hydrogen atom, a halogen atom , A cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms).

The halogen atom in the R ¹ to R ¹⁵ and R ^b1 to R ^b8, fluorine atom, chlorine atom, bromine atom and iodine atom, a fluorine atom is preferable.

Examples of the alkyl group in R ^{1 to} R ¹⁵ and R ^{b1 to} R ^b8 include specific examples of the alkyl group in R ^aa described above. From the viewpoint of ease of synthesis of the hole transporting compound (1), methyl Group, ethyl group and isopropyl group are preferable, and methyl group is particularly preferable.

Examples of the alkoxy group in R ^{1 to} R ¹⁵ and R ^{b1 to} R ^b8 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isopropoxy group, an isobutoxy group, and a tertiary butoxy group. Group, propoxy group and butoxy group are preferable, and methoxy group is particularly preferable.

Regarding the thiol-containing group (E) in R ^{1 to} R ¹⁵ and R ^{b1 to} R ^b8, examples of the alkylene group include specific examples of the alkylene group in the thiol-containing group (E) in R ^aa described above.

  Two or more thiol-containing groups (E) are contained in total in the hole transporting compound (1-ii). Thereby, the preferable effect which is mentioned later in the multilayering of an organic compound layer is exhibited.

  The hole transporting compound (2) having a skeleton structure represented by the following formula (2) is:

In formula (2), R ²⁹ is a substituent (C1) represented by the following formula (C1) or a substituent (D1) represented by the following formula (D1).

(In the formula (C1), a plurality of R ^ccs are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), q
Represents 0, 1 or 2. )

(In the formula (D1), a plurality of R ^dds are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), and r
Represents 0, 1 or 2. )
(2-i) First, the case where R ²⁹ is a substituent (C1) (hole transporting compound (2-i)) will be described.

^Examples of the alkyl group for R ^cc in the substituent (C1) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tertiary butyl group, an amyl group, and a hexyl group. From the viewpoint of ease of synthesis of the transportable compound (2), a methyl group, an ethyl group, and an isopropyl group are preferable, and a methyl group is particularly preferable.

For thiol-containing group (E) in the R ^cc, the alkylene group include a methylene group, an ethylene group, a propylene group, butylene group.

R ^{21 to} R ²⁸ in the skeleton structure and R ^c1 in the substituent (C1) are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, 10 alkoxy groups or a thiol-containing group (E) represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms).

Examples of the halogen atom in R ^{21 to} R ²⁸ and R ^c1 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

Examples of the alkyl group in R ^{21 to} R ²⁸ and R ^c1 include the specific examples of the alkyl group in R ^cc described above. From the viewpoint of ease of synthesis of the hole transporting compound (2), a methyl group, ethyl Group and isopropyl group are preferable, and methyl group and ethyl group are particularly preferable.

Examples of the alkoxy group in R ^{21 to} R ²⁸ and R ^c1 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isopropoxy group, an isobutoxy group, and a tertiary butoxy group. Group, butoxy group is preferable, and methoxy group is particularly preferable.

As for the thiol-containing group (E) in R ^{21 to} R ²⁸ and R ^c1, examples of the alkylene group include specific examples of the alkylene group in the thiol-containing group (E) in R ^cc described above.

  Two or three or more thiol-containing groups (E) are contained in the hole transporting compound (2-i) in total. Thereby, the preferable effect which is mentioned later in the multilayering of an organic compound layer is exhibited.

(2-ii) Next, the case where R ²⁹ is a substituent (D1) (hole transporting compound (2-ii)) will be described.

Examples of the alkyl group in R ^dd in the substituent (D1) include specific examples of the alkyl group in R ^cc described above. From the viewpoint of ease of synthesis of the hole transporting compound (2), a methyl group, ethyl Group, isopropyl group is preferable, and methyl group is particularly preferable.

Regarding the thiol-containing group (E) in R ^dd, examples of the alkylene group include specific examples of the alkylene group in the thiol-containing group (E) in R ^cc described above.

R ^{21 to} R ²⁸ in the skeleton structure and R ^{d1 to} R ^d8 in the substituent (D1) are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, carbon A thiol-containing group (E) represented by the following formula (E):

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms).

Examples of the halogen atom in R ^{21 to} R ²⁸ and R ^{d1 to} R ^d8 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

Examples of the alkyl group in R ^{21 to} R ²⁸ and R ^{d1 to} R ^d8 include specific examples of the alkyl group in R ^cc described above. From the viewpoint of ease of synthesis of the hole transporting compound (2), methyl Group, ethyl group and isopropyl group are preferable, and methyl group is particularly preferable.

Examples of the alkoxy group in R ^{21 to} R ²⁸ and R ^{d1 to} R ^d8 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isopropoxy group, an isobutoxy group, and a tertiary butoxy group. Group, propoxy group and butoxy group are preferable, and methoxy group is particularly preferable.

Regarding the thiol-containing group (E) in R ^{21 to} R ²⁸ and R ^{d1 to} R ^d8, examples of the alkylene group include specific examples of the alkylene group in the thiol-containing group (E) in R ^cc described above.

  Two or three or more thiol-containing groups (E) are contained in the hole transporting compound (2-ii) in total. Thereby, the preferable effect which is mentioned later in the multilayering of an organic compound layer is exhibited.

  Specific examples of the hole transporting compound (1) represented by the formula (1) include hole transporting compounds represented by the following formulas (A1-1) to (A1-2) and (B1-1). It is done.

In the hole transporting compound (A1-1), in the hole transporting compound (1), R ⁸ is a substituent (
A1) is substituted and n is 1. At this time, it is preferable that the divalent group interposed between N at the center of the skeleton structure and N in the substituent (A1) is not substituted with the thiol-containing group (E). In other words, R ^{6 to} R ⁷ , R ^{9 to} R ¹⁰ and four R ^aa are preferably a hydrogen atom or the above alkyl group. And it is preferable that two or more of R ^{1 to} R ⁵ , R ^{11 to} R ¹⁵ , R ^{a1 to} R ^a5 and R ^{a6 to} R ^a10 are the thiol-containing group (E),
The group that is not the thiol-containing group (E) is preferably a hydrogen atom or the alkyl group. Further, ^{one or} more of R ^{1 to} R ⁵ and R ^{11 to} R ¹⁵ are the thiol-containing group (E), and one or more of R ^{a1 to} R ^a5 and R ^{a6 to} R ^a10 are the thiol-containing groups. More preferably, the group that is the group (E) and is not the thiol-containing group (E) is a hydrogen atom or the alkyl group.

The hole transporting compound (A1-2) is a case where R ³ , R ⁸ and R ¹³ are substituted with a substituent (A1) in the hole transporting compound (1), and n is 0. At this time, it is preferable that the divalent group interposed between N at the center of the skeleton structure and N in the substituent (A1) is not substituted with the thiol-containing group (E). In other words, R ^{1 to} R ² , R ^{4 to} R ⁵ , R ^{6 to} R ⁷ , R ⁹ to
R ¹⁰ , R ^{11 to} R ¹² and R ^{14 to} R ¹⁵ are preferably a hydrogen atom or the above alkyl group. And it is preferable that two or more of R ^{a1 to} R ^a10 (a total of 30 groups of ^three R ^{a1 to} R ^a10 each) are the thiol-containing group (E), and the thiol-containing group (E) It is preferable that the group which is not is a hydrogen atom or the said alkyl group.

The hole transporting compound (B1-1) is a case where R ³ , R ⁸ and R ¹³ are substituted with the substituent (B1) in the hole transporting compound (1), and p is 0. At this time, it is preferable that the divalent group interposed between N at the center of the skeleton structure and N in the substituent (A1) is not substituted with the thiol-containing group (E). In other words, R ^{1 to} R ² , R ^{4 to} R ⁵ , R ^{6 to} R ⁷ , R ⁹ to
R ¹⁰ , R ^{11 to} R ¹² and R ^{14 to} R ¹⁵ are preferably a hydrogen atom or the above alkyl group. And it is preferable that two or more of R ^{b1 to} R ^b8 (a total of 24 groups of three R ^{b1 to} R ^b8 each) is the thiol-containing group (E), and the thiol-containing group (E) It is preferable that the group which is not is a hydrogen atom or the said alkyl group.

  Specific examples of the hole transporting compound (2) represented by the formula (2) include hole transporting compounds represented by the following formulas (C1-1) and (D1-1).

In the hole-transporting compound (C1-1), in the hole-transporting compound (2), R ²⁹ is a substituent (
This is the case when q is 0. At this time, R ^c1 is preferably the alkyl group. And it is preferable that two or more of R ^{21 to} R ²⁴ and R ^{25 to} R ²⁸ are the thiol-containing group (E), and the group that is not the thiol-containing group (E) is a hydrogen atom or the alkyl group. Preferably there is. Furthermore, one or more of R ^{21 to} R ²⁴ are the thiol-containing group (E), and one or more of R ^{25 to} R ²⁸ are the thiol-containing group (E), and the thiol-containing group ( More preferably, the group other than E) is a hydrogen atom or the above alkyl group.

The hole transporting compound (D1-1) is a case where R ²⁹ is substituted with a substituent (D1) and r is 2 in the hole transporting compound (2). At this time, it is preferable that the divalent group interposed between N in the skeleton structure and N in the substituent (D1) is not substituted with the thiol-containing group (E). In other words, R ^dd is preferably a hydrogen atom or the above alkyl group. And it is preferable that two or more of R ^{21 to} R ²⁴ , R ^{25 to} R ²⁸ , R ^{d1 to} R ^d4 and R ^{d5 to} R ^d8 are the thiol-containing group (E), and the thiol-containing group (E ) Is preferably a hydrogen atom or the above alkyl group.

In the composition, a solvent is used together with the organic compound A. As the solvent, various organic solvents can be used. For example, aromatic solvents such as toluene, xylene, anisole, halogenated alkyl solvents such as chloroform and dichloroethane, alcohol solvents such as methanol and ethanol, acetone, Examples include ketone solvents such as methyl ethyl ketone and ether solvents such as dimethoxyethane and THF. These solvents may be used as a mixture. In particular, toluene and methanol are preferably used. The solvent is usually used in an amount of 100 to 100,000 parts by mass with respect to 100 parts by mass of the organic compound A.

  In addition, the composition may contain an oxidizing agent in order to increase the rate of reaction described later. Examples of the oxidizing agent include bromine, iodine, oxygen, hydrogen peroxide and the like, and iodine is particularly preferably used. The oxidizing agent is usually used in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the organic compound A.

  Furthermore, the composition may contain the organic compound B which does not have two or more thiol groups. Examples of the organic compound B include organic EL compounds having no two or more thiol groups as described below.

  The organic compound B is used in a range that does not adversely affect the multilayering of the organic compound layer as described later, and is usually used in an amount of 1 to 200 parts by mass with respect to 100 parts by mass of the organic compound A.

  The composition is obtained by dissolving or dispersing the organic compound A and, if necessary, the above components in a solvent.

  The coating method of the composition is not particularly limited, but the spin coating method, the casting method, the micro gravure coating method, the gravure coating method, the bar coating method, the roll are mainly formed on the layer where the organic compound layer by the composition is to be formed. It can be formed by a coating method such as a coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, or an inkjet printing method. Here, the layer for which the organic compound layer is to be formed of the composition is, for example, an anode or an organic compound layer already formed on the anode.

  Moreover, it is preferable to apply | coat the composition the quantity by which a suitable film thickness is obtained after a 2nd process.

[Second step]
In the second step, the composition applied in the first step is heated and the organic compounds A are reacted with each other to be insolubilized. Thus, the organic compound layer is formed in the present invention.

  Specifically, insolubilization is a material solution for forming a new organic compound layer on the organic compound layer formed in the first step and the second step, and a material solution using an organic solvent as a solvent. Even when applied, it means that the organic compound layer obtained through the first step and the second step does not dissolve.

  For insolubilization, for example, the reduction rate of the thickness of the organic compound layer obtained through the first step and the second step when the following treatment is performed ((1−thickness after treatment / thickness before treatment). (S) x 100 (%)), this reduction rate is, for example, 30% or less, preferably 10% or less, and more preferably 5% or less. In the present specification, “insolubilized” means that the reduction rate is in the above range.

  (Process): A substrate (25 mm square, plate thickness 1.1 mm, blue plate glass) provided on the surface with an organic compound layer obtained through the first step and the second step having a thickness of 20 nm is set on a spin coater. Then, 0.10 ml of toluene is dropped onto the layer, and then rotated at 3000 rpm for 30 seconds. This rotation starts within 5 seconds after the dropwise addition of toluene. Thereafter, the layer is left at 140 ° C. for 1 hour in a nitrogen atmosphere.

  In addition, in the production method of the present invention, “reacting the organic compounds A with each other to insolubilize” means (or in addition to the above description) thiol groups of the organic compound A (specifically different organic compounds). The thiol groups contained in the molecule of A are reacted to form an —SS— bond, thereby connecting the organic compound A to increase the molecular weight.

  The formation of this -S-S- bond can be confirmed by the method described in Examples.

  Organic compound layer obtained through the first step and the second step (in this specification, such an organic compound layer is also referred to as a high molecular weight organic compound layer) and one or more organic compound layers thereon The organic EL element having the above is excellent in terms of efficiency and lifetime.

  The cause is considered as follows. In the organic compound layer having a high molecular weight, since the organic compound A has a high molecular weight due to —S—S— bond, the organic compound layer having a high molecular weight can be formed even when an organic compound layer is further laminated thereon by a coating method. The compound layer does not dissolve. Further, it is considered that the disorder of the interface between the high molecular weight organic compound layer and the organic compound layer thereon is suppressed. This is considered to be excellent in terms of efficiency and life.

  An organic EL device having only one organic compound layer obtained through the first step and the second step as the organic compound layer is also excellent in terms of efficiency and life.

  The cause is considered as follows. In the organic compound layer formed by a conventional ordinary coating method, a cavity formed by evaporation of the solvent is not sufficiently filled and a dense film may not be formed. On the other hand, the organic compound layer having a high molecular weight according to the present invention is a dense film in which the cavity formed by evaporation of the solvent is sufficiently filled when the organic compound A has a high molecular weight by -SS-bonding. It is thought that is formed. This is considered to be excellent in terms of efficiency and life.

In JP-A-2000-223278, after immersing an electrode in a solution of a compound having a mercapto group, the excess solution is washed away and dried under reduced pressure, thereby forming a single to several molecular layers of the compound on the electrode surface. It is described that an ultra-thin film is formed. By this method, an attempt is made to form an organic layer on which other layers can be coated (laminated) on a mild condition. However, in this method, the mercapto group of the compound is bonded to the atoms constituting the electrode, so that the compound is insolubilized. Therefore, it is considered that only the monomolecular layer on the electrode surface is insolubilized. That is, it is not the organic compound layer having a high molecular weight described above. This document describes that a compound layer having a mercapto group can be stacked several tens to several hundreds of nanometers larger than the thickness of a monomolecular layer, and can serve as a hole transport layer ([0044] ) Since this film is not a high molecular weight organic compound layer, when it is further laminated by coating, there is a high possibility that it will be dissolved in the solvent. Is considered difficult to form.

  The heating temperature and heating time in the second step are appropriately selected so that the organic compound A has a sufficiently high molecular weight. For example, the heating temperature is preferably 30 ° C to 200 ° C. It is preferable from the point of reaction rate as it is 30 degreeC or more, and it is preferable from the point of the heat resistance of a compound as it is 200 degrees C or less. Moreover, it is more preferable that it is 40 to 150 degreeC, and it is further more preferable that it is 50 to 100 degreeC. The heating time is preferably 0.5 to 12 hours.

  The organic compound layer obtained through the first step and the second step is usually less than 10 μm, preferably 0.5 μm or less, more preferably 0.0001 to 0.5 μm.

  When manufacturing an organic EL device in which two or more organic compound layers are formed between a pair of electrodes, that is, between an anode and a cathode, the organic compound layer (first layer) laminated on the anode is the first described above. It is preferable to form by a process and a 2nd process. Thereby, the organic EL element which is excellent in terms of efficiency and lifetime can be obtained.

  Moreover, it is also preferable to further form one or more organic compound layers by the following two steps on the organic compound layer formed by the first step and the second step.

Third step: A step of applying a composition containing an organic compound having two or more thiol groups, which is different from the organic compound A,
Fourth step: A step of heating the composition applied in the third step to react and insolubilize thiol groups of an organic compound different from the organic compound A.

  Here, “an organic compound different from the organic compound A” is different from the organic compound A (specifically, the organic compound a1) used in the first step and the second step, but is selected from the organic compounds A described above. Organic compound (specifically, organic compound a2). In addition, specific descriptions of the third step and the fourth step are the same as those of the first step and the second step described above, respectively.

  In other words, it is also preferable to repeat the first step and the second step twice or more. That is, in the case of manufacturing an organic EL device in which two or more organic compound layers are formed between an anode and a cathode, the two adjacent organic compound layers are both subjected to the first step and the second step described above. Preferably it is formed. Here, the organic compound used in the first step and the second step of the first time and the organic compound used in the first step and the second step of the second time are organic compounds selected from the organic compound A described above, respectively. Organic compounds that are different from each other. Thereby, the organic EL element which is excellent in terms of efficiency and lifetime can be obtained. Thereby, the organic EL element which is excellent in terms of efficiency and lifetime can be obtained.

  For example, when manufacturing an organic EL device in which three or more organic compound layers are formed between the anode and the cathode, the organic compound layer (first layer) laminated on the anode is the first step and the second step described above. More preferably, the organic compound layer (second layer) formed thereon is formed by the third step and the fourth step described above.

  Moreover, when forming a 1st layer and a 2nd layer by a 1st process-a 4th process, it is also preferable that the organic compound A used in order to form a 1st layer has a 3 or more thiol group.

  Moreover, when manufacturing the organic EL element in which the organic compound layer of two or more layers was formed between the anode and the cathode, it is also preferable to form an organic compound layer by the 1st process-the 4th process mentioned above.

  In addition, you may provide an organic compound layer by the normal apply | coating method on the organic compound layer obtained through the 1st process and the 2nd process. The provision of the organic compound layer by a normal coating method means, for example, that a solution containing an organic EL compound (an organic EL compound not having two or more thiol groups) and an organic solvent is applied to form an organic compound layer. Say.

  Hereinafter, more specific embodiments of the present invention will be described.

Embodiment 1
The manufacturing method of Embodiment 1 is a manufacturing method of an organic EL element in which a substrate / anode / hole transport layer / light emitting layer / cathode is laminated in this order as shown in FIG. Here, the hole transport layer is formed by the first step and the second step, and the light emitting layer is formed by a normal coating method or vapor deposition method.

  A material that satisfies the mechanical strength required for the organic EL element is used for the substrate. For example, a substrate transparent to visible light is used. Specifically, glass such as soda glass and non-alkali glass; transparent plastic such as acrylic resin, methacrylic resin, polycarbonate resin, polyester resin, and nylon resin; silicon, etc. Can be used.

  The thickness of the substrate is preferably 0.1 to 10 mm, more preferably 0.25 to 2 mm, although it depends on the required mechanical strength.

  First, an anode is provided on the substrate by, for example, vacuum deposition, electron beam deposition, sputtering, chemical reaction, or coating.

  As the anode, a material having a surface resistance of preferably 1000 ohms or less, more preferably 100 ohms or less in a temperature range of -5 to 80 ° C can be used.

  When extracting light from the anode side of the organic EL element (bottom emission), the anode needs to be transparent to visible light (average transmittance for light of 380 to 680 nm is 50% or more). Examples of the material for the anode include indium tin oxide (ITO), indium-zinc oxide (IZO), and the like, and ITO is preferable among them because it is easily available as the anode of the organic EL element.

  In addition, when light is extracted from the cathode side of the organic EL element (top emission), the light transmittance of the anode is not limited, and the anode material is ITO, IZO, stainless steel, or copper, silver, gold, platinum. , Tungsten, titanium, tantalum or niobium, or an alloy thereof can be used.

  In the case of bottom emission, the thickness of the anode is preferably 2 to 300 nm in order to achieve high light transmittance, and in the case of top emission, it is preferably 2 nm to 2 mm.

  Next, a hole transport layer is formed on the anode by the first step and the second step described above. Here, the above-described hole transporting compound (1) or (2) is preferably used.

  Next, a light emitting layer is provided on the hole transport layer. The light-emitting layer uses a solution containing a light-emitting compound and an organic solvent, and is mainly used for spin coating, casting, micro gravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip It can be formed by a coating method such as a coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, or an inkjet printing method.

  The luminescent compound used here is not usually the organic compound A, that is, not a compound containing two or more thiol groups. Specifically, Omori Hiroshi: luminescent low molecular weight compound and luminescent high molecular weight compound described in Applied Physics, Vol. 70, No. 12, pp. 1419-1425 (2001), wherein a thiol group Examples thereof include compounds not containing two or more. Among these, a light-emitting polymer compound is preferable in that the element manufacturing process is simplified, and a phosphorescent compound is preferable in terms of high luminous efficiency. Therefore, a phosphorescent polymer compound is particularly preferable.

  The light-emitting polymer compound can be classified into a conjugated light-emitting polymer compound and a non-conjugated light-emitting polymer compound, and among them, the non-conjugated light-emitting polymer compound is preferable.

  For the reasons described above, the phosphorescent material used in the present invention is particularly preferably a phosphorescent non-conjugated polymer compound (the phosphorescent polymer and the non-conjugated luminous polymer compound). .

  The light emitting layer preferably contains at least a phosphorescent polymer having a phosphorescent unit that emits phosphorescence and a carrier transporting unit that transports carriers in one molecule. The phosphorescent polymer can be obtained by copolymerizing a phosphorescent compound having a polymerizable substituent and a carrier transporting compound having a polymerizable substituent. The phosphorescent compound is a metal complex containing a metal element selected from iridium, platinum and gold, and among them, an iridium complex is preferable.

  More specific examples and synthesis methods of phosphorescent polymers are disclosed in, for example, JP-A Nos. 2003-342325, 2003-119179, 2003-113246, and 2003-206320. JP 2003-147021 A, JP 2003-171391 A, JP 2004-346212 A, and JP 2005-97589 A.

The light emitting layer is preferably a layer containing the phosphorescent compound, but for the purpose of supplementing the carrier transport property of the light emitting layer, it is a hole transporting compound or an electron transporting compound and contains two or more thiol groups. May be included. In other words, the light emitting layer may be an electron transport / light emitting layer as in Example 1 described later. As the hole transporting compound used for these purposes, for example, TPD (N, N′-dimethyl-N, N ′-(3-methylphenyl) -1,1′-biphenyl-4,4′diamine) is used. , Α-NPD (4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), m-MTDATA (4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) Low molecular triphenylamine derivatives such as triphenylamine), polyvinyl carbazole, and polymers obtained by introducing a polymerizable functional group into the triphenylamine derivative, for example, disclosed in JP-A-8-157575 Examples include a polymer compound of a triphenylamine skeleton, polyparaphenylene vinylene, and polydialkylfluorene (these do not contain two or more thiol groups). Examples of the electron transporting compound include quinolinol derivative metal complexes such as Alq3 (tris (8-hydroxyquinolinato) aluminum (III)), oxadiazole derivatives, triazole derivatives, imidazole derivatives, triazine derivatives, and triarylboranes. A low molecular material such as a derivative, or a polymer obtained by introducing a polymerizable functional group into the above low molecular electron transporting compound, for example, a poly PBD disclosed in JP-A-10-1665 Electron transporting compounds (these do not contain two or more thiol groups) can be used.

  Finally, a cathode is formed on the light emitting layer by resistance heating vapor deposition, electron beam vapor deposition, sputtering, ion plating, or the like.

  As the cathode material of the organic EL optical device of the present invention, a material having a low work function and being chemically stable is used, and known cathodes such as Al, MgAg alloy, Al and alkali metal alloys such as AlLi and AlCa, etc. The material can be exemplified, but in view of chemical stability, the work function is preferably −2.9 eV or less.

  The thickness of the cathode is preferably 10 nm to 1 μm, and more preferably 50 to 500 nm.

  As described above, an organic EL device in which the substrate / anode / hole transport layer / light emitting layer / cathode is laminated in this order is obtained. In the manufacturing method of Embodiment 1, since the hole transport layer is an organic compound layer having a high molecular weight formed in the first step and the second step, an organic EL element excellent in terms of efficiency and life is finally obtained. It is done.

  Embodiment 1 may be a method for manufacturing an organic EL element in which a substrate / anode / first hole transport layer / second hole transport layer / light emitting layer / cathode are laminated in this order. Here, the first hole transport layer and the second hole transport layer are formed by the first step and the second step, and the light emitting layer is formed by a normal coating method. The first hole transport layer and the second hole transport layer are preferably appropriately selected from the above-described hole transport compounds (1) and (2) so as to be two layers having different ionization potentials.

[Embodiment 2]
The manufacturing method of Embodiment 2 is a manufacturing method of an organic EL element in which a substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode are laminated in this order as shown in FIG. Here, the hole transport layer is formed by the first step and the second step, the light emitting layer is formed by a normal coating method, and the electron transport layer is formed by a vapor deposition method.

  In the second embodiment, the lamination of the substrate, the anode, the hole transport layer, and the light emitting layer is the same as the manufacturing method of the first embodiment.

  Next, in Embodiment 2, an electron transport layer is provided on the formed light emitting layer by a vapor deposition method.

  Finally, a cathode is formed on the electron transport layer in the same manner as in the manufacturing method of the first embodiment.

  As described above, an organic EL device in which the substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode is laminated in this order is obtained. In the manufacturing method of Embodiment 2, since the hole transport layer is an organic compound layer having a high molecular weight in the first step and the second step, an organic EL element excellent in terms of efficiency and life is finally obtained. It is done.

Moreover, in the form of Embodiment 2, a positive hole transport layer and a light emitting layer may be formed by said 1st process and a 2nd process, and an electron carrying layer may be normally formed by the apply | coating method. In this case, the electron transport layer is mainly composed of a solution containing an electron transport compound and an organic solvent, and mainly a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire coating method. It can be formed by a coating method such as a bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, and an ink jet printing method.

  The electron transporting compound used here is not usually the organic compound A, that is, not a compound containing two or more thiol groups. Specifically, the electron transport compound which may be included in the light emitting layer of Embodiment 1 mentioned above is mentioned.

  Embodiment 2 may be a method for manufacturing an organic EL element in which a substrate / anode / first hole transport layer / second hole transport layer / light emitting layer / electron transport layer / cathode are laminated in this order. . Here, the first hole transport layer and the second hole transport layer are formed by the first step and the second step, the light emitting layer is formed by a normal coating method, and the electron transport layer is formed by a vapor deposition method. Alternatively, the first hole transport layer, the second hole transport layer and the light emitting layer are formed by the first step and the second step, and the electron transport layer is formed by a normal coating method or vapor deposition method. . The first hole transport layer and the second hole transport layer are preferably appropriately selected from the above-described hole transport compounds (1) and (2) so as to be two layers having different ionization potentials.

  The organic EL device obtained in Embodiment 2 has functions of separating carrier transport and light emission, so that the degree of freedom of material selection is greatly increased and various compounds having different emission wavelengths can be used. Diversification of luminescent hues becomes possible. In addition, it is possible to effectively confine each carrier or exciton in the central light emitting layer to improve the light emission efficiency.

[Embodiment 3]
The manufacturing method of Embodiment 3 is a manufacturing method of an organic EL element in which a substrate / anode / light emitting layer / cathode is laminated in this order as shown in FIG. Here, the light emitting layer is formed by the first step and the second step.

  In the third embodiment, the lamination of the substrate and the anode is the same as the manufacturing method of the first embodiment.

  Next, in Embodiment 3, a light emitting layer is formed on the anode by the first process and the second process described above. Here, the light emitting compound which has the 2 or more thiol group mentioned above is used suitably.

  Finally, a cathode is formed on the light emitting layer in the same manner as in the manufacturing method of the first embodiment.

  As described above, an organic EL element in which the substrate / anode / light emitting layer / cathode is laminated in this order is obtained. In the manufacturing method of Embodiment 3, since the light emitting layer is an organic compound layer having a high molecular weight by the first step and the second step, an organic EL element excellent in terms of efficiency, life and the like is finally obtained.

  In addition, the light emitting compound may be a case where it has a hole transport ability, an electron transport ability and a light emission performance by itself, and a mixture of compounds having respective characteristics is used. Also good.

In Embodiments 1 to 3, a protective layer for protecting the organic EL element may be mounted after the cathode is manufactured. In order to use the organic EL element stably for a long period of time, it is preferable to attach a protective layer and / or a protective cover in order to protect the element from the outside. As the protective layer, a polymer compound, metal oxide, metal fluoride, metal boride and the like can be used. As the protective cover, a glass plate, a plastic plate with a low water permeability treatment on the surface, a metal, or the like can be used. The cover is bonded to the element substrate with a thermosetting resin or a photocurable resin and sealed. Is preferably used. If a space is maintained using a spacer, it is easy to prevent the element from being damaged. If an inert gas such as nitrogen or argon is sealed in the space, the cathode can be prevented from being oxidized, and moisture adsorbed in the manufacturing process by installing a desiccant such as barium oxide in the space. It becomes easy to suppress giving an image to an element. Among these, it is preferable to take any one or more measures.

  Embodiments 1 to 3 are very basic device configurations, and the configuration of the organic EL device obtained by the production method of the present invention is not limited to these. For example, various layer configurations such as providing an insulating layer at the interface between the electrode and the organic layer, providing an adhesive layer or interference layer, and inserting an electron injection layer with good electron injection efficiency into the cathode or electron transport layer interface can be adopted. it can.

<Organic EL element and its use>
The organic EL device of the present invention is obtained by the above-described manufacturing method. The organic EL element of the present invention is suitably used in an image display device as a matrix or segment pixel. The organic EL element is also suitably used as a surface light source without forming pixels.

  Specifically, the organic EL device of the present invention includes a display device in a computer, a television, a mobile terminal, a mobile phone, a car navigation system, a sign, a signboard, a viewfinder of a video camera, a backlight, electrophotography, illumination, resist exposure. It is preferably used for a light irradiation device in a reading device, interior lighting, an optical communication system or the like.

[Example]
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[Evaluation methods]
(1) Method of measuring initial luminance, current efficiency, and luminance after 100 hours A voltage is applied stepwise to the organic EL element using a constant voltage power source (Keithley, SM2400), and the luminance of the organic EL element is measured with a luminance meter ( Quantification was performed with Topcon's BM-9). Luminous efficiency was determined from the ratio of luminance to current density.

  Moreover, the light emission lifetime measurement was performed by continuing applying a constant current to the organic EL element using the same apparatus and measuring the luminance at regular intervals.

(2) Insolubilization (Preparation of laminates A and B)
Separately from the organic EL elements of the following examples, for the evaluation of insolubilization (calculation of the reduction rate), on the blue plate glass (25 mm square, plate thickness 1.1 mm), the first step described in the examples described later and Two laminates provided with a high molecular weight organic compound layer (thickness 20 nm) were produced by the procedure of the second step, and were designated as laminate A and laminate B, respectively.

(Measurement of organic compound layer thickness)
A part of the organic compound layer of the layered product A is cut with a needle to expose the substrate (hereinafter, the substrate surface thus exposed is also referred to as “substrate exposed portion”), and using an AFM (atomic force microscope). By observing the surface of the laminate A on the side of the organic compound layer so as to cross the exposed portion of the substrate as shown in FIG. 4, the organic compound layer (hereinafter also referred to as “organic compound layer before dissolution test treatment”). The thickness of was measured.

(Dissolution test processing)
The organic compound layer having a high molecular weight of the laminate B was subjected to the following dissolution test treatment.

  After 0.10 ml of toluene was dropped on the organic compound layer of the laminate B, it was rotated at 3000 rpm for 30 seconds. This rotation started within 5 seconds after the dropwise addition of toluene. The sample was then left for 1 hour at 140 ° C. under a nitrogen atmosphere.

  Thereafter, the thickness of the organic compound layer of the laminate B (hereinafter also referred to as “organic compound layer after the dissolution test treatment”) is measured by the same method as that of the laminate A, and is defined by the following formula: The “reduction rate (%)” of the thickness of the organic compound layer was calculated.

Reduction rate = (1−Thickness of organic compound layer after dissolution test treatment / Thickness of organic compound layer before dissolution test treatment) × 100
In addition, about Example 3, about the case where the laminated body A and the laminated body B which provided the 1st positive hole transport layer and the laminated body A and the laminated body B which provided the 1st positive hole transport layer were used. Each of the above evaluations was performed.

(3) High molecular weight High molecular weight was confirmed by disappearance of the thiol group.

(Preparation of laminate C)
Compound B and 0.1 wt% of iodine with respect to compound B were dissolved in toluene to prepare a 2.0 wt% (total concentration of compound B and iodine) coating solution. Using this coating solution, a film was formed on blue plate glass (25 mm square, plate thickness 1.1 mm) by spin coating (2000 rpm), and heat-treated at 60 ° C. for 10 minutes and 120 ° C. for 1 hour to 50 nm. A laminate C was prepared.

(Preparation of laminate D)
Compound B was dissolved in toluene to prepare a 2.0 wt% coating solution. Using this coating solution, a film was formed on a blue plate glass (25 mm square, plate thickness 1.1 mm) by a spin coating method (2000 rpm), and dried at room temperature under reduced pressure to produce a 50 nm laminate D.

(Disappearance of thiol group)
As a result of IR measurement, the peak of 2564 cm ⁻¹ derived from the SH group found in the laminate D was not seen in the laminate C, so that the thiol groups reacted with each other, and the —SS— bond was observed. It is thought that the molecular weight was increased by the generation.

Even in the organic compound layers obtained through the first step and the second step in Examples 1 to 3, it is considered that the peak at 2564 cm ⁻¹ derived from the SH group is not observed at all. Therefore, it is considered that the thiol groups react with each other to generate -S-S- bonds, thereby increasing the molecular weight.

[Example 1]
What formed indium tin oxide (ITO) into a film thickness of 120 nm on the glass substrate by the sputtering method was used as a transparent conductive support substrate. This was ultrasonically washed successively with acetone and isopropyl alcohol (IPA), boiled and washed with IPA, and dried. Furthermore, what was UV / ozone cleaned was used as a transparent conductive support substrate.

(First Step and Second Step) Compound A was dissolved in toluene to prepare a 2.0 wt% coating solution. Using this coating solution, a film is formed on a transparent support substrate by spin coating (2000 rpm), and heat treatment is performed at 140 ° C. for 2 hours to produce an organic compound layer having a thickness of 50 nm, thereby forming a hole transport layer. did.

Next, a mixture of Compound P and Compound X in a weight ratio of 10:90 was dissolved in toluene, and 2.0 w
A coating solution of t% was prepared. Compound X was synthesized by the method described in JP-A No. 2005-006368. Using this coating solution, a film was formed on the previously prepared film by spin coating (2000 rpm) and heat-treated at 140 ° C. for 1 hour in a nitrogen atmosphere to form a 50 nm film, and an electron transport / light emitting layer Formed.

Further, using a vapor deposition material composed of aluminum and lithium (lithium concentration of 1 atomic%), a metal layer film having a thickness of 150 nm is formed on the organic layer by vacuum deposition, and the element having the structure shown in FIG. Was made. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec. Table 1 shows the results obtained by continuously emitting light for 100 hours by applying a DC voltage in a vacuum with the ITO electrode as the positive electrode and the aluminum-lithium electrode as the negative electrode.

[Comparative Example 1]
Compound A of Example 1 was changed to N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4′-diamino-1,1′-biphenyl to form a hole transport layer. Otherwise, the device of Comparative Example 1 was fabricated in exactly the same manner as the device of Example 1. Table 1 shows the results obtained by continuously emitting light for 100 hours by applying a DC voltage in a vacuum with the ITO electrode as the positive electrode and the aluminum-lithium electrode as the negative electrode.

[Example 2]
What formed indium tin oxide (ITO) into a film thickness of 120 nm on the glass substrate by the sputtering method was used as a transparent conductive support substrate. This was ultrasonically washed successively with acetone and isopropyl alcohol (IPA), boiled and washed with IPA, and dried. Furthermore, what was UV / ozone cleaned was used as a transparent conductive support substrate.

  (First Step and Second Step) 0.1 wt% iodine was dissolved in toluene with respect to Compound B and Compound B to prepare a coating solution of 2.0 wt% (total concentration of Compound B and iodine). Using this coating solution, a film was formed on a transparent support substrate by a spin coating method (2000 rpm), and heat-treated at 60 ° C. for 10 minutes and at 120 ° C. for 1 hour, and a 50 nm organic compound layer (hole transport layer) Was made.

Next, a mixture of Compound P and Compound X in a weight ratio of 10:90 was dissolved in toluene, and 2.0 w
A coating solution of t% was prepared. Using this coating solution, a film was formed on the previously prepared film by spin coating (2000 rpm) and heat-treated at 140 ° C. for 1 hour in a nitrogen atmosphere to form a 50 nm film, and an electron transport / light emitting layer Formed.

Further, using a vapor deposition material composed of aluminum and lithium (lithium concentration of 1 atomic%), a metal layer film having a thickness of 150 nm is formed on the organic layer by vacuum deposition, and the element having the structure shown in FIG. Was made. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.

When a direct current voltage was applied to the device thus fabricated using an ITO electrode as an anode and an aluminum-lithium electrode as a cathode, 32.9 cd / A of green light emission was observed. The other results are also shown in Table 1.

[Example 3]
What formed indium tin oxide (ITO) into a film thickness of 120 nm on the glass substrate by the sputtering method was used as a transparent conductive support substrate. This was ultrasonically washed successively with acetone and isopropyl alcohol (IPA), boiled and washed with IPA, and dried. Furthermore, what was UV / ozone cleaned was used as a transparent conductive support substrate.

  (First Step and First Step) 0.1 wt% iodine is dissolved in toluene with respect to Compound B and Compound B to prepare 2.0 wt% (total concentration of Compound B and iodine). did. Using this coating solution, a film is formed on a transparent support substrate by a spin coating method (2000 rpm), and heat-treated at 60 ° C. for 10 minutes and at 120 ° C. for 1 hour, and a 50 nm organic compound layer (first hole transport) Layer).

(Second Step 1 and Step 2) Next, Compound C is dissolved in toluene, and 1.0 w is added.
A coating solution of t% was prepared. Using this coating solution, a film was formed by spin coating (2000 rpm) on the previously prepared film, and heat-treated at 140 ° C. for 2 hours to form an organic compound layer (second hole transport layer) having a thickness of 20 nm. Was made.

Next, a mixture of Compound P and Compound X in a weight ratio of 10:90 was dissolved in toluene, and 2.0 w
A coating solution of t% was prepared. Using this coating solution, a film was formed on the previously prepared film by spin coating (2000 rpm) and heat-treated at 140 ° C. for 1 hour in a nitrogen atmosphere to form a 50 nm film, and an electron transport / light emitting layer Formed.

Furthermore, using a vapor deposition material composed of aluminum and lithium (lithium concentration 1 atom%), a metal layer film having a thickness of 150 nm is formed on the organic layer by a vacuum vapor deposition method. In the structure shown in FIG. A device having a structure in which the hole transport layer was changed to the first hole transport layer and the second transport layer was produced. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.

When a direct current voltage was applied to the device thus fabricated using an ITO electrode as an anode and an aluminum-lithium electrode as a cathode, a green light emission of 42.3 cd / A was observed. The other results are also shown in Table 1.

Claims (11)

A method of manufacturing an organic electroluminescence device including one or more organic compound layers formed between a pair of electrodes, wherein at least one organic compound layer is formed by the following two steps: Manufacturing method of electroluminescence element;
1st process: The process of apply | coating the composition containing the organic compound A which has a 2 or more thiol group,
2nd process: The process of heating the composition apply | coated by the 1st process and making the thiol group which the organic compound A has react, and making it insolubilize.   The method for producing an organic electroluminescent element according to claim 1, wherein the organic compound A is a hole transporting compound, an electron transporting compound, or a light emitting compound. The method for producing an organic electroluminescent element according to claim 1, wherein the organic compound A is a hole transporting compound represented by the following general formula (1).

[In formula (1), at least one of R ² , R ³ , R ⁸ and R ¹³ is a substituent (A1) represented by the following formula (A1),

(In the formula (A1), a plurality of R ^aa are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E):

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), and n
Represents 0, 1 or 2. )
R ^a1 to R ^a10 of R ¹ to R ¹⁵ and in the substituent (A1) not substituted with a substituent (A1) of R ¹ to R ¹⁵ of the skeletal structure (1) are each independently a hydrogen atom , A halogen atom, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (1) in total. ] The method for producing an organic electroluminescent element according to claim 1, wherein the organic compound A is a hole transporting compound represented by the following general formula (1).

[In the formula (1), at least one of R ² , R ³ , R ⁸ and R ¹³ is a substituent (B1) represented by the following formula (B1),

(In the formula (B1), a plurality of ^Rbbs are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), p
Represents 0, 1 or 2. )
R ^b1 to R ^b8 of R ¹ to R ¹⁵ and in the substituent (B1) not substituted with a substituent (B1) of R ¹ to R ¹⁵ of the skeletal structure (1) are each independently a hydrogen atom , A halogen atom, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thiol-containing group represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (1) in total. ] The method for producing an organic electroluminescent element according to claim 1, wherein the organic compound A is a hole transporting compound represented by the following general formula (2).

[In the formula (2), R ²⁹ is a substituent (C1) represented by the following formula (C1) or a substituent (D1) represented by the following formula (D1),

(In the formula (C1), a plurality of R ^ccs are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), q
Represents 0, 1 or 2. )

(In the formula (D1), a plurality of R ^dds are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)).

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms), and r
Represents 0, 1 or 2. )
(2-i) when R ²⁹ is a substituent (C1),
R ^{21 to} R ²⁸ in the skeleton structure (2) and R ^c1 in the substituent (C1) are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, carbon A thiol-containing group (E) represented by the following formula (E):

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (2) in total,
(2-ii) when R ²⁹ is a substituent (D1),
R ^{21 to} R ²⁸ in the skeleton structure (2) and R ^{d1 to} R ^d8 in the substituent (D1) are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, or an alkyl having 1 to 10 carbon atoms. Group, an alkoxy group having 1 to 10 carbon atoms, or a thiol-containing group (E) represented by the following formula (E)

(In formula (E), ^Re represents a single bond or an alkylene group having 1 to 10 carbon atoms),
Two or more thiol-containing groups (E) are contained in the hole transporting compound (2) in total. ] One or more organic compound layers are further formed on the organic compound layer formed by the first step and the second step by the following two steps. The manufacturing method of the organic electroluminescent element as described in one.
Third step: A step of applying a composition containing an organic compound having two or more thiol groups, which is different from the organic compound A,
Fourth step: A step of heating the composition applied in the third step to react and insolubilize thiol groups of an organic compound different from the organic compound A.   The said composition contains an oxidizing agent further, The manufacturing method of the organic electroluminescent element as described in any one of Claims 1-6 characterized by the above-mentioned.   The manufacturing temperature of the organic electroluminescent element according to any one of claims 1 to 7, wherein a heating temperature in the second step is 30C to 200C.   The organic electroluminescent element obtained by the manufacturing method as described in any one of Claims 1-8.   A display apparatus provided with the organic electroluminescent element of Claim 9.   A surface-emitting light source comprising the organic electroluminescence element according to claim 9.

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