WO2021044478A1

WO2021044478A1 - Ionic compound, organic electronics material, organic layer, organic electronics element, organic electroluminescent element, display element, lighting device, and method for manufacturing organic electronics element

Info

Publication number: WO2021044478A1
Application number: PCT/JP2019/034408
Authority: WO
Inventors: 和幸加茂; 伊織福島; 健一石塚; 貴紀宮; 俊輔児玉
Original assignee: 昭和電工マテリアルズ株式会社
Priority date: 2019-09-02
Filing date: 2019-09-02
Publication date: 2021-03-11
Also published as: JP2024037956A; JPWO2021044478A1; JP7444170B2

Abstract

An ionic compound containing an ammonium cation represented by formula (1a) and an anion has excellent heat resistance. In formula (1a), Ra, Rb and Rc independently represent a hydrogen atom or a monovalent organic group, wherein at least two radicals selected from Ra, Rb and Rc independently represent a monovalent organic group and at least one radical selected from Ra, Rb and Rc represents an organic group having a double bond.

Description

Ionic compounds, organic electronics materials, organic layers, organic electronics elements, organic electroluminescence elements, display elements, lighting devices, and methods for manufacturing organic electronics elements.

An embodiment of the present invention relates to an ionic compound, an organic electronic material, an organic layer, an organic electronic element, an organic electroluminescence element, a display element, a lighting device, and a method for manufacturing an organic electronic element.

Organic electronics devices are devices that perform electrical operations using organic substances, and are expected to exhibit features such as energy saving, low cost, and flexibility, and are attracting attention as a technology that replaces conventional silicon-based inorganic semiconductors. Has been done.

Examples of organic electronic devices include organic electroluminescence devices (hereinafter, also referred to as organic EL devices), organic photoelectric conversion devices, and organic transistors.

Among organic electronic devices, organic EL devices are attracting attention as large-area solid-state light source applications as alternatives to, for example, incandescent lamps and gas-filled lamps. It is also attracting attention as the most promising self-luminous display that can replace the liquid crystal display (LCD) in the flat panel display (FPD) field, and its commercialization is progressing.

Organic EL devices are roughly classified into two types, low-molecular-weight organic EL devices and high-molecular-weight organic EL devices, according to the organic materials used. In the high molecular weight organic EL device, a high molecular weight material is used as the organic material, and in the low molecular weight organic EL device, a low molecular weight material is used. Compared to low-molecular-weight organic EL devices, which are mainly formed in a vacuum system, high-molecular-weight organic EL devices can be easily formed by wet processes such as printing and inkjet. It is expected as an indispensable element for EL displays.

For this reason, the development of materials suitable for wet processes is underway.

Japanese Unexamined Patent Publication No. 2006-279007 International Publication No. 2010/1405553

Generally, an organic EL device manufactured by a wet process using a polymer material has the features that it is easy to reduce the cost and increase the area. However, an organic EL device containing a thin film produced by using a conventional polymer material is desired to be further improved in the characteristics of the organic EL device such as driving voltage, luminous efficiency, and luminous life. Further, since high-temperature baking is required in the process of drying the solvent in the production of the organic EL device, high-temperature process resistance is also desired for each material.

The present invention has been made in view of the above, and the embodiment of the present invention is an organic electronic material that can be used for an organic electronic element having excellent element characteristics, and an excellent heat resistance that can be used for the organic electronic material. It is an object of the present invention to provide an ionic compound. Another embodiment aims to provide an organic layer using the organic electronic material, and an organic electronic device, an organic electroluminescence device, a display element, and a lighting device including the organic layer. Furthermore, another embodiment aims to provide a method for manufacturing an organic electronic device using the organic electronic material.

One embodiment of the present invention relates to an ionic compound containing an ammonium cation and an anion represented by the following formula (1a).

In formula (1a), ^Ra , R ^b and R ^c each independently represent a hydrogen atom or a monovalent organic group, and at least two selected from ^Ra , R ^b and R ^{c are monovalent organic.} A group, ^{at least one selected from Ra} , R ^b and R ^c is an organic group containing a double bond.

Further, another embodiment of the present invention relates to an organic electronics material containing the ionic compound and the charge transporting compound.

Further, another embodiment of the present invention relates to an organic layer formed by using the organic electronic material.

Further, another embodiment of the present invention relates to an organic electronic device provided with the organic layer.

Further, another embodiment of the present invention relates to an organic electroluminescence device provided with the organic layer.

Further, another embodiment of the present invention relates to a display element including the organic electroluminescence element.

Further, another embodiment of the present invention relates to a lighting device including the organic electroluminescence element.

Further, another embodiment of the present invention relates to a display element including the lighting device and a liquid crystal element as a display means.

Further, another embodiment of the present invention relates to a method for manufacturing an organic electronic element, which comprises a step of forming an organic layer by a coating method using the organic electronic material.

According to the embodiment of the present invention, it is possible to provide an organic electronic material that can be used for an organic electronic device having excellent element characteristics, and an ionic compound that can be used for the organic electronic material and has excellent heat resistance. Further, according to another embodiment of the present invention, it is possible to provide an organic layer using the organic electronic material, and an organic electronic device, an organic electroluminescence device, a display element, and a lighting device including the organic layer. .. Further, according to another embodiment of the present invention, it is possible to provide a method for manufacturing an organic electronic device using the organic electronic material.

It is a schematic cross-sectional view which shows an example of the organic EL element which is one Embodiment of this invention.

Hereinafter, the ionic compound, the organic electronics material, the organic layer, the organic electronics element, the organic electroluminescence element, the display element, and the lighting device according to the embodiment of the present invention will be described in detail.

The embodiment of the present invention is as follows.

<1> An ionic compound containing an ammonium cation and an anion represented by the following formula (1a).

<2> The ionic compound according to <1>, wherein the organic group containing the double bond has 2 to 6 carbon atoms.

<3> The ionic compound according to <1> or <2>, wherein the double bond is located at the terminal of the organic group.

<4> The ionic compound according to any one of <1> to <3>, wherein the organic group has 4 or less carbon atoms in each of ^Ra , R ^b, and R ^c.

<5> The organic group containing the double bond is any one of <1> to <4> selected from the group consisting of a vinyl group, a propenyl group, an isopropenyl group, a butenyl group, and an isobutenyl group. Or the ionic compound according to item 1.

<6> The ionic compound according to any one of <1> to <5>, which contains only one organic group containing the double bond.

<7> The item according to any one of <1> to <5>, which contains two or more organic groups containing the double bond, and each of the organic groups containing the double bond is the same as each other. Ionic compounds according to.

<8> The ionic compound according to any one of <1> to <7>, wherein the anion is represented by any of the following formulas (1b) to (5b).

In formulas (1b) to (5b), E ¹ represents an oxygen atom, E ² represents a nitrogen atom, E ³ represents a carbon atom, E ⁴ represents a boron atom or a gallium atom, E ⁵ represents a phosphorus atom or an antimony atom, and Y ¹ ~ Y ⁶ independently represent a single bond or a divalent linking group, and R ¹ to R ¹⁶ each independently represent an electron-attracting monovalent group (R ² and R ³ , R ⁴ to R ^6). At least two groups selected from, at least two groups selected from ^{R 7} to R ¹⁰ ^{, and at least two groups selected from R 11} to R ^{16 may each be attached to each other.)} Represents.

<9> An organic electronic material containing the ionic compound and the charge transporting compound according to any one of <1> to <8>.

<10> The unit according to <9>, wherein the charge transporting compound has at least one unit selected from the group consisting of a unit containing an aromatic amine structure, a unit containing a carbazole structure, and a unit containing a thiophene structure. Organic electronics materials.

<11> The organic electronic material according to <9> or <10>, wherein the charge transporting compound has one or more polymerizable functional groups in the molecule.

<12> The organic electronic material according to <11>, wherein the polymerizable functional group contains at least one selected from the group consisting of an oxetane group, an epoxy group, and a vinyl ether group.

<13> The organic electronic material according to any one of <9> to <12>, which further contains a solvent.

<14> An organic layer formed by using the organic electronic material according to any one of <9> to <13>.

An organic electronic device provided with the organic layer according to <15> and <14>.

<16> The organic electronics element according to <15>, which has another organic layer on the organic layer.

<17> The organic electronic device according to <15> or <16>, which further has a substrate, and the substrate has flexibility.

<18> The organic electronic device according to <15> or <16>, further comprising a substrate, wherein the substrate is a resin film.

An organic electroluminescence device provided with the organic layer according to <19> and <14>.

<20> The organic electroluminescence device according to <19>, wherein the organic layer is a hole injection layer.

<21> The organic electroluminescence device according to <19>, wherein the organic layer is a hole transport layer.

<22> The organic electroluminescence device according to <19>, wherein the organic layer is a light emitting layer.

<23> The organic electroluminescence device according to any one of <19> to <22>, which has a white emission color.

<24> The organic electroluminescence device according to any one of <19> to <23>, further comprising a substrate, wherein the substrate has flexibility.

<25> The organic electroluminescence device according to any one of <19> to <23>, further comprising a substrate, wherein the substrate is a resin film.

A display device including the organic electroluminescence device according to any one of <26> and <19> to <25>.

<27> A lighting device provided with the organic electroluminescence element according to any one of <19> to <25>.

A display element including the lighting device according to <28> and <27> and a liquid crystal element as a display means.

<29> A method for manufacturing an organic electronic device, which comprises a step of forming an organic layer by a coating method using the organic electronic material according to <13>.

<Ionic compound>
The ionic compound of this embodiment comprises an ammonium cation and an anion represented by the following formula, which will be described later. Hereinafter, ammonium cations and anions will be described. The ionic compound of the present embodiment is preferably used as a dopant for organic electronic materials. When the charge-transporting polymer contains a polymerizable functional group, the ionic compound of the present embodiment is preferably used as a polymerization initiator.

(Ammonium cation)
The ammonium cation of the ionic compound of this embodiment is represented by the following formula (1a).

In formula (1a), ^Ra , R ^b and R ^c each independently represent a hydrogen atom or a monovalent organic group, and at least two selected from ^Ra , R ^b and R ^{c are monovalent organic.} It is the basis. Examples of the monovalent organic group include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an arylalkyl group and the like. These groups may further have a substituent, and examples of the substituent include an alkyl group, and an alkyl group having 1 to 10 carbon atoms is preferable. At ^{least two of R a} , R ^b and R ^c may be bonded to each other to form a ring. R ^a , R ^b and R ^c may be the same or different from each other. Further, ^{at least one selected from Ra} , R ^b and R ^c is an organic group containing a double bond. Examples of the organic group containing a double bond include an alkenyl group and the like.

In the present specification and the like, the organic group means an atomic group having one or more carbon atoms.
In the present specification and the like, the aryl group means an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. Examples of the aromatic hydrocarbon include a monocyclic ring, a condensed ring, or a polycyclic ring in which two or more selected from an independent monocyclic ring and a condensed ring are bonded via a single bond.
In the present specification and the like, the heteroaryl group refers to an atomic group obtained by removing one hydrogen atom from an aromatic heterocycle. Examples of the aromatic heterocycle include a monocyclic ring, a condensed ring, or a polycyclic ring in which two or more selected from an independent monocyclic ring and a condensed ring are bonded via a single bond.

Specific examples of R ^a , R ^b, and R ^c will be described, but the present invention is not limited to the following.

The alkyl group may be linear, branched or cyclic, and may have a substituent. The alkyl group preferably has 1 to 24 carbon atoms, more preferably 2 to 18 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, an i-butyl group, a t-butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group and an octyl group. 2-Ethylhexyl group, nonyl group, decyl group, dodecyl group, tetradecyl group, octadecyl group, 3,7-dimethyloctyl group, lauryl group, trifluoromethyl group, pentafluoroethyl group, perfluorobutyl group, perfluorohexyl group , Perfluorooctyl group and the like.

The alkenyl group may be linear, branched or cyclic, and may have a substituent. The alkenyl group preferably has 2 to 12, more preferably 2 to 8, and even more preferably 2 to 6. Specific examples of the alkenyl group include vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-octenyl group and 1-decenyl group. Examples include 1-octadecenyl group.

The alkynyl group may be linear, branched or cyclic, and may have a substituent. The carbon number of the alkynyl group is preferably 2 to 12, more preferably 2 to 8, and even more preferably 2 to 6. Specific examples of the alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-octynyl group, 1-decynyl group and 1-octadecynyl group. And so on.

The aryl group may further have a substituent, and examples of the substituent include an alkyl group, and an alkyl group having 1 to 10 carbon atoms is preferable. The monovalent aryl group in the unsubstituted state preferably has 6 to 60 carbon atoms, more preferably 6 to 30 carbon atoms, and further preferably 6 to 18 carbon atoms. Specifically, a phenyl group, a C1 to C12 alkoxyphenyl group (C1 to C12 indicate that the substituent has 1 to 12 carbon atoms; the same applies hereinafter), a C1 to C12 alkylphenyl group, Examples thereof include 1-naphthyl group, 2-naphthyl group, 1-anthrasenyl group, 2-anthrasenyl group, 9-anthrasenyl group, phenanthrene-yl group, pyrene-yl group, perylene-yl group, pentafluorophenyl group and the like.

Specific examples of C1-C12 alkyl include methyl, ethyl, propyl, i-propyl, butyl, i-butyl, t-butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, 3 , 7-Dimethyloctyl, lauryl and the like are exemplified.

The heteroaryl group may further have a substituent, and examples of the substituent include an alkyl group, and an alkyl group having 1 to 10 carbon atoms is preferable. The monovalent heteroaryl group in the unsubstituted state preferably has 4 to 60 carbon atoms, more preferably 4 to 40 carbon atoms, and further preferably 4 to 20 carbon atoms. Specifically, a thienyl group, a C1 to C12 alkylthenyl group, a pyrrolyl group, a frill group, a pyridyl group, a C1 to C12 alkylpyridyl group and the like are exemplified, and a thienyl group, a C1 to C12 alkylthenyl group, a pyridyl group, a C1 to A C12 alkylpyridyl group is preferred. Examples of C1-C12 alkyl are as described above.

The arylalkyl group is a group in which at least one hydrogen atom of the alkyl group is substituted with an aryl group. The arylalkyl group may further have a substituent, and examples of the substituent include an alkyl group, and an alkyl group having 1 to 10 carbon atoms is preferable. The monovalent arylalkyl group in the unsubstituted state preferably has 7 to 19 carbon atoms, more preferably 7 to 16 carbon atoms, and further preferably 7 to 13 carbon atoms. Examples of the alkyl group include the above-mentioned alkyl group, and examples of the aryl group include the above-mentioned aryl group. Specifically, a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, a diphenylmethyl group and the like are exemplified.

In the formula (1a), the organic group containing a double bond preferably has 2 to 6 carbon atoms. When the organic group containing a double bond has 2 to 6 carbon atoms, the ammonium cation of the ionic compound of the present embodiment can be easily produced, and the organic electronics element containing the ammonium cation can be used. Excellent element characteristics such as drive voltage, light emission efficiency, and light emission life can be obtained.

Generally, by increasing the carbon number (for example, 5 or more carbon atoms) of ^{the substituent of the ammonium cation (corresponding to Ra} , R ^b, R ^c, etc. in the ammonium cation of the ionic compound of the present embodiment), the solvent can be used. We are studying the improvement of the solubility of ionic compounds and the heat resistance of ionic compounds. On the other hand, the ammonium cation of the ionic compound of the present embodiment ^{is an organic group having at least one selected from Ra} , R ^b and R ^c containing a double bond, and is an organic group containing a double bond. It is considered that the heat resistance of the ionic compound is improved because the ammonium cation is stabilized by the cross-linking.

Therefore, the ionic compound of the present embodiment containing an organic group containing a double bond is excellent in heat resistance without increasing the carbon number of ^{the substituents Ra} , R ^b and R ^{c of the ammonium cation.} For ^example, R a, number of carbon atoms of the organic group in each of ^{R b} and ^{R c} ^(R a, one of ^{R b} and ^{R c} include be a hydrogen atom) is preferably 4 or less, more 3 or less preferable. It is considered that the small number of carbon atoms in the organic group suppresses the residual of bulky impurities and improves the element characteristics of the organic electronic device.

The double bond is preferably located at the terminal of the organic group, and examples of the organic group containing the double bond include a vinyl group, a propenyl group, an isopropenyl group, a butenyl group, and an isobutenyl group. And so on.

When the ammonium cation of the ionic compound of the present embodiment contains two or more organic groups containing a double bond, the organic groups containing the double bond are the same from each other from the viewpoint of ease of production. Is preferable.

(Anion)
The anion is not particularly limited, and for example, a known anion can be used. The viewpoint that the anion represented by the following formulas (1b), (2b), (3b), (4b) or (5b) drives the organic electronic element for a long time, and further, the viewpoint of reducing the driving voltage of the organic electronic element. Is preferable.

In formulas (1b) to (5b), E ¹ represents an oxygen atom, E ² represents a nitrogen atom, E ³ represents a carbon atom, E ⁴ represents a boron atom or a gallium atom, and E ⁵ represents a phosphorus atom or an antimony atom.
Y ¹ to Y ⁶ independently represent a single bond or a divalent linking group, respectively.
R ¹ to R ¹⁶ are at least two groups independently selected from electron-attracting monovalent groups (R ² and R ³ , R ⁴ to R ⁶ and at least R ⁷ to R ^10). The two ^{groups and at least two groups selected from R 11} to R ¹⁶ may each be attached to each other).

In the formulas (1b) to (5b), R ¹ to R ¹⁶ each independently represent an electron-attracting monovalent group. An electron-attracting monovalent group is a substituent that is more likely to attract an electron from the bonding atom side than a hydrogen atom. R ¹ to R ¹⁶ are preferably organic groups. At ^{least two groups selected from R 2} and R ³ , R ⁴ to R ^6, at least two groups selected from R ⁷ to R ¹⁰ , and at least two groups selected from ^{R 11} to R ¹⁶ , Each may be coupled to each other. The bonded groups may be cyclic.

Examples of electron-attracting monovalent groups include halogen atoms such as fluorine atom, chlorine atom and bromine atom; cyano group; thiocyano group; nitro group; alkylsulfonyl group such as mesil group (for example, 1 to 12 carbon atoms). , Preferably 1 to 8 carbon atoms, more preferably 1 to 6); arylsulfonyl groups such as tosyl groups (for example, 6 to 18 carbon atoms, preferably 6 to 15 carbon atoms, still more preferably 6 to 12 carbon atoms); Alkyloxysulfonyl groups such as methoxysulfonyl groups (eg 1-12 carbons, preferably 1-8 carbons, more preferably 1-6 carbons); aryloxysulfonyl groups such as phenoxysulfonyl groups (eg 6-carbons) 18, preferably 6 to 15 carbon atoms, more preferably 6 to 12 carbon atoms); acyl groups such as formyl groups, acetyl groups, benzoyl groups (for example, 1 to 12 carbon atoms, preferably 1 to 9 carbon atoms, still more preferable. 1 to 6 carbon atoms); acyloxy groups such as formyloxy groups and acetoxy groups (for example, 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, more preferably 1 to 6 carbon atoms); methoxycarbonyl groups, ethoxycarbonyl groups. An alkoxycarbonyl group such as a group (for example, 2 to 10 carbon atoms, preferably 2 to 8 carbon atoms, more preferably 2 to 7 carbon atoms); an "aryloxycarbonyl group or heteroaryl" such as a phenoxycarbonyl group or a pyridyloxycarbonyl group. "Oxycarbonyl group" (eg, 4 to 25 carbon atoms, preferably 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms); linear, branched or cyclic such as trifluoromethyl group and pentafluoroethyl group. "Haloalkyl group, haloalkenyl group or haloalkynyl group" in which a halogen atom is substituted with the "alkyl group, alkenyl group or alkynyl group" (for example, 1 to 10, preferably 1 to 8, more preferably carbon number). 1 to 6); A haloaryl group in which an aryl group such as a pentafluorophenyl group is substituted with a halogen atom (for example, 6 to 20 carbon atoms, preferably 6 to 16 carbon atoms, more preferably 6 to 12 carbon atoms); pentafluorophenyl. Examples thereof include a haloarylalkyl group in which an arylalkyl group such as a methyl group is substituted with a halogen atom (for example, 7 to 19 carbon atoms, preferably 7 to 16 carbon atoms, and more preferably 7 to 13 carbon atoms).

Further, as an example of an electron-attracting monovalent group, from the viewpoint of efficiently delocalizing a negative charge, among the examples of the electron-attracting monovalent group, "organic group having a hydrogen atom". A group in which a part or all of the hydrogen atom is replaced with a halogen atom is preferable. For example, a perfluoroalkylsulfonyl group, a perfluoroarylsulfonyl group, a perfluoroalkyloxysulfonyl group, a perfluoroaryloxysulfonyl group, a perfluoroacyl group, a perfluoroacyloxy group, a perfluoroalkoxycarbonyl group, a perfluoroaryloxycarbonyl group. , Perfluoroalkyl group, perfluoroalkenyl group, perfluoroalkynyl group, perfluoroaryl group, perfluoroarylalkyl group and the like.

Examples of electron-attracting monovalent groups include, in particular, a linear or branched perfluoroalkyl group having 1 to 8 carbon atoms, a cyclic perfluoroalkyl group having 3 to 6 carbon atoms, or carbon. Perfluoroaryl groups of number 6-18 are preferred.

The monovalent group of electronic attractiveness is not limited to these. The example of the electron-attracting monovalent group shown above may have a substituent or may have a hetero atom.

Specific examples of the electron-attracting monovalent group include the groups shown in the following substituent group (1). In the present specification and the like, "*" in the structural formula represents a binding site with another structural unit.

Substituent group (1)

In formulas (1b) to (5b), Y ¹ to Y ⁶ independently represent a single bond or a divalent linking group, respectively. When Y ¹ to Y ⁶ are single bonds, it means that E and R are directly bonded (for example, in the formula (1b), E ¹ and R ¹ are directly bonded). Examples of the divalent linking group include a linking group represented by any of the following formulas (1c) to (11c).

In the formulas (7c) to (11c), R independently represents a hydrogen atom or a monovalent group, and is preferably an organic group. It is more preferable that R is an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heteroaryl group independently from the viewpoints of improving electron acceptability, solubility in a solvent and the like. These groups may have substituents or heteroatoms. Further, R is preferably an electron-attracting monovalent group, and examples of the electron-attracting monovalent group include the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group. , Or the group shown in the substituent group (1).

The ionic compound of this embodiment has excellent heat resistance and can be used for organic electronic devices. Further, when used together with a charge transporting compound having a polymerizable functional group described later, the curability at a low temperature can be improved and the film forming property can be improved.

<Organic electronics materials>
The organic electronic material of the present embodiment contains the ionic compound of the above-described embodiment, and may contain only one type of ionic compound or two or more types of ionic compound. The organic electronic material of the present embodiment may further contain a charge transporting compound. By using the organic electronic material containing the ionic compound of the above-described embodiment, it is possible to obtain an organic electronic element having excellent driving voltage, luminous efficiency, luminous life and the like.

[Charge transporting compound]
The organic electronics material may contain a charge transporting compound. The charge transporting compound may be a low molecular weight compound or a polymer. From the viewpoint of solubility in an organic solvent, a polymer is preferable, and from the viewpoint of easy purification by sublimation, recrystallization, etc., a low molecular weight compound is preferable. The "polymer" includes an oligomer having a low degree of polymerization (for example, a number average degree of polymerization of 2 or more and 20 or less) and a polymer having a high degree of polymerization (for example, a number average degree of polymerization of more than 20). The charge transporting compound may be a commercially available compound or may be synthesized by a known method, and is not particularly limited.

The charge transporting compound preferably contains at least one unit selected from the group consisting of a unit containing an aromatic amine structure, a unit containing a carbazole structure, and a unit containing a thiophene structure.
The charge transporting compound preferably has one or more polymerizable functional groups in the molecule. The polymerizable functional group is not particularly limited, and preferred polymerizable functional groups include an oxetane group, an epoxy group, and a vinyl ether group.
When the charge transporting compound has a polymerizable functional group, the curability at low temperature is improved when the organic electronics material containing the charge transporting compound and the ionic compound of the above-described embodiment is used as an ink composition. Therefore, the film forming property at a low temperature can be improved.

(Charge transport polymer)
Hereinafter, the charge transporting polymer will be described.
Charge-transporting polymers have the ability to transport charges. The charge-transporting polymer may be linear or may have a branched structure. The charge-transporting polymer preferably contains at least a divalent structural unit D having charge transportability and a monovalent structural unit M constituting the terminal portion, and contains a trivalent or higher-valent structural unit T constituting the branch portion. Further may be included. The charge-transporting polymer may contain only one type of each structural unit, or may contain a plurality of types of each structural unit. Each structural unit is bound to each other at a binding site of "monovalent" to "trivalent or higher".

(Structure of charge transport polymer)
Examples of the partial structure contained in the charge transport polymer include the following. The charge-transporting polymer is not limited to those having the following partial structures. In the partial structure, "D" represents the structural unit D, "M" represents the structural unit M, and "T" represents the structural unit T. In the partial structure contained in the charge-transporting polymer shown below, "*" in the formula represents a binding site with another structural unit. In the following substructures, the plurality of Ds may be the same structural unit or different structural units from each other. The same applies to M and T.

Linear charge transport polymer

Charge-transporting polymer with a branched structure

(Structural unit D)
The structural unit D is a divalent structural unit having charge transportability. The structural unit D is not particularly limited as long as it includes an atomic group capable of transporting electric charges. For example, the structural unit D is a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, biphenyl structure, terphenyl structure, naphthalene structure, anthracene structure, tetracene structure, phenanthrene structure, dihydro. Phenanthrene structure, pyridine structure, pyrazine structure, quinoline structure, isoquinoline structure, quinoxalin structure, aclysine structure, diazaphenanthrene structure, furan structure, pyrrole structure, oxazole structure, oxaziazole structure, thiazole structure, thiazazole structure, triazole structure, benzo It is selected from a thiophene structure, a benzoxazole structure, a benzoxaziazole structure, a benzothiazole structure, a benzothiazazole structure, a benzotriazole structure, and a structure containing one or more of these. The aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure.

In the present embodiment, the structural unit D is a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, pyrrole structure, and these, from the viewpoint of obtaining excellent hole transportability. It is preferable to select from a structure containing one or more of these, and select from a substituted or unsubstituted aromatic amine structure, a carbazole structure, a thiophene structure, and a structure containing one or more of these. It is more preferable to be done. The structural unit D is derived from a substituted or unsubstituted fluorene structure, benzene structure, phenanthrene structure, pyridine structure, quinoline structure, and a structure containing one or more of these, from the viewpoint of obtaining excellent electron transportability. It is preferably selected.

Specific examples of the structural unit D include the following. The structural unit D is not limited to the following.

R independently represents a hydrogen atom or a substituent. When R is a substituent, the substituents are independently -R ¹ , -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ , and a halogen atom, and It is preferably selected from the group consisting of groups containing polymerizable functional groups, which will be described later. R ¹ to R ⁸ independently represent a hydrogen atom; a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms; or an aryl group or a heteroaryl group having 2 to 30 carbon atoms. The alkyl group may be further substituted with an aryl group or a heteroaryl group having 2 to 20 carbon atoms, and the aryl group or the heteroaryl group may be further substituted with a linear, cyclic or branched group having 1 to 22 carbon atoms. It may be substituted with an alkyl group. R is preferably a hydrogen atom, an alkyl group, an aryl group, or an alkyl-substituted aryl group. Ar represents an arylene group or a heteroarylene group having 2 to 30 carbon atoms. Ar is preferably an arylene group, more preferably a phenylene group. In the present specification and the like, the arylene group means an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon. Further, in the present specification and the like, the heteroarylene group means an atomic group obtained by removing two hydrogen atoms from an aromatic heterocycle. The description of the aromatic hydrocarbon and the aromatic heterocycle is the same as that of the aryl group and the heteroaryl group.

(Structural unit M)
The structural unit M is a monovalent structural unit constituting the terminal portion of the charge-transporting polymer. The structural unit M is not particularly limited, and is selected from, for example, a substituted or unsubstituted aromatic hydrocarbon structure, an aromatic heterocyclic structure, and a structure containing one or more of these. The structural unit M may have the same structure as the structural unit D except for the valence. In the present embodiment, the structural unit M is preferably a substituted or unsubstituted aromatic hydrocarbon structure from the viewpoint of imparting durability without lowering the charge transportability, and is preferably a substituted or unsubstituted benzene. The structure is more preferable. Further, as will be described later, when the charge-transporting polymer has a polymerizable functional group at the terminal portion, the structural unit M has a polymerizable structure (that is, a polymerizable functional group such as a pyrrole-yl group). May be good. Specific examples of the structural unit M include the following.

In the above formula, R includes a hydrogen atom or a substituent listed as R in the structural unit D. When the charge-transporting polymer has a polymerizable functional group at the terminal portion, it is preferable that at least one of R is a group containing a polymerizable functional group.

(Structural unit T)
The structural unit T is a trivalent or higher structural unit constituting the branched portion when the charge-transporting polymer has a branched structure. From the viewpoint of improving the durability of the organic electronic device, the structural unit T is preferably a hexavalent or lower structural unit, more preferably a tetravalent or lower structural unit, and further preferably a trivalent or tetravalent structural unit. Is. The structural unit T is preferably a unit having charge transportability. For example, the structural unit T is a substituted or unsubstituted triphenylamine structure, a carbazole structure, a condensed polycyclic aromatic hydrocarbon structure, and one or two of these, from the viewpoint of improving the durability of the organic electronic device. Includes at least one selected from structures containing more than one species. The structural unit T may have the same structure as the structural unit D except for the valence, and may have the same structure as the structural unit M except for the valence.

Specific examples of the structural unit T include the following. The structural unit T is not limited to the following.

W represents a trivalent linking group, for example, an arene triyl group having 2 to 30 carbon atoms or a heteroarene triyl group. In the present specification and the like, the arene triyl group refers to an atomic group obtained by removing three hydrogen atoms from an aromatic hydrocarbon. In the present specification and the like, the heteroarene triyl group refers to an atomic group obtained by removing three hydrogen atoms from an aromatic heterocycle. Ar independently represents a divalent linking group, and for example, each independently represents an arylene group or a heteroarylene group having 2 to 30 carbon atoms. Ar is preferably an arylene group, more preferably a phenylene group. Y represents a divalent linking group, for example, from the group having one or more hydrogen atoms among the substituents listed as R (excluding the group containing a polymerizable functional group) in the structural unit D. Examples thereof include a divalent group excluding one hydrogen atom. Z represents either a carbon atom, a silicon atom, or a phosphorus atom. In the structural unit, the fused ring, W, Y, and Ar may have a substituent, and examples of the substituent include the substituents listed as R in the structural unit D.

(Polymerizable functional group)
In the present embodiment, the charge-transporting polymer is preferably cured by a polymerization reaction and has at least one polymerizable functional group from the viewpoint of changing the solubility in a solvent. The "polymerizable functional group" refers to a functional group capable of forming a bond with each other by applying at least one of heat and light.

The polymerizable functional group includes a group having a carbon-carbon multiple bond (for example, a vinyl group, an allyl group, a butenyl group, an ethynyl group, an acryloyl group, an acryloyloxy group, an acryloylamino group, a methacryloyl group, a methacryloyloxy group, and a methacryloylamino group. Group, vinyloxy group, vinylamino group, etc.), group having a small ring (for example, cyclic alkyl group such as cyclopropyl group, cyclobutyl group; cyclic ether group such as epoxy group (oxylanyl group), oxetan group (oxetanyl group)) Examples thereof include a diketen group; an episulfide group; a lactone group; a lactam group, etc.), a heterocyclic group (for example, a furan-yl group, a pyrrole-yl group, a thiophen-yl group, a silol-yl group) and the like. These groups may further have a substituent, and examples of the substituent include an alkyl group, and an alkyl group having 1 to 10 carbon atoms is preferable. As the polymerizable functional group, a vinyl group, an acryloyl group, a methacryloyl group, an epoxy group, and an oxetane group are particularly preferable, and a vinyl group, an oxetan group, or an epoxy group is more preferable from the viewpoint of reactivity and characteristics of the organic electronic device. preferable.

From the viewpoint of increasing the degree of freedom of the polymerizable functional group and facilitating the occurrence of a polymerization reaction, it is preferable that the main skeleton of the charge-transporting polymer and the polymerizable functional group are linked by an alkylene chain.
Further, for example, when an organic layer is formed on an electrode, a hydrophilic chain such as an ethylene glycol chain or a diethylene glycol chain is used from the viewpoint of improving the affinity with a hydrophilic electrode such as ITO (indium oxide-tin oxide). It is preferable that they are connected. Further, from the viewpoint of facilitating the preparation of the monomer used for introducing the polymerizable functional group, the charge-transporting polymer polymerizes with at least one of the terminal portions of the alkylene chain and the hydrophilic chain, that is, these chains. At least one of the linking portion with the sex functional group and the connecting portion between these chains and the skeleton of the charge-transporting polymer may have an ether bond or an ester bond. The above-mentioned "group containing a polymerizable functional group" means a polymerizable functional group itself or a group in which a polymerizable functional group and an alkylene chain are combined. As the group containing the polymerizable functional group, for example, the group exemplified in International Publication No. 2010/1405553 can be preferably used.

The polymerizable functional group is introduced at the terminal portion (that is, the structural unit M) of the charge-transporting polymer or at a portion other than the terminal portion (that is, the structural unit D or T). It may be introduced in both the and non-terminal parts. From the viewpoint of curability, it is preferable that it is introduced at least at the terminal portion, and from the viewpoint of achieving both curability and charge transportability, it is preferable that it is introduced only at the terminal portion. Further, when the charge-transporting polymer has a branched structure, the polymerizable functional group may be introduced into the main chain or the side chain of the charge-transporting polymer, and both the main chain and the side chain may be introduced. It may be introduced in.

It is preferable that the polymerizable functional group is contained in a large amount in the charge-transporting polymer from the viewpoint of contributing to the change in solubility. On the other hand, the polymerizable functional group preferably contains a small amount in the charge-transporting polymer from the viewpoint of not hindering the charge-transporting property. The content of the polymerizable functional group can be appropriately set in consideration of these.

For example, the number of polymerizable functional groups per molecule of the charge-transporting polymer is preferably 2 or more, and more preferably 3 or more, from the viewpoint of obtaining a sufficient change in solubility. The number of polymerizable functional groups is preferably 1,000 or less, more preferably 700 or less, and even more preferably 500 or less, from the viewpoint of maintaining charge transportability.

The number of polymerizable functional groups per molecule of the charge-transporting polymer is the amount of the polymerizable functional group charged (for example, the amount of the monomer having the polymerizable functional group) used for synthesizing the charge-transporting polymer, and each structure. It can be obtained as an average value by using the amount of the monomer charged corresponding to the unit, the weight average molecular weight of the charge-transporting polymer, and the like. The number of polymerizable functional groups is the ratio of the integrated value of the signal derived from the polymerizable functional group in ^{the 1} H NMR (nuclear magnetic resonance) spectrum of the charge transport polymer to the integrated value of the entire spectrum, and the charge transport polymer. It can be calculated as an average value by using the weight average molecular weight of. When the amount to be charged is clear, it is preferable to adopt the value obtained by using the amount to be charged because it is convenient.

(Number average molecular weight)
The number average molecular weight of the charge-transporting polymer can be appropriately adjusted in consideration of solubility in a solvent, film-forming property, and the like. The number average molecular weight is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more, from the viewpoint of excellent charge transportability. The number average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, and more preferably 50,000 or less, from the viewpoint of maintaining good solubility in the solvent and facilitating the preparation of the ink composition. The following is more preferable.

(Weight average molecular weight)
The weight average molecular weight of the charge-transporting polymer can be appropriately adjusted in consideration of solubility in a solvent, film-forming property, and the like. The weight average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, still more preferably 10,000 or more, from the viewpoint of excellent charge transportability. The weight average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, and more preferably 400,000 or less, from the viewpoint of maintaining good solubility in the solvent and facilitating the preparation of the ink composition. The following is more preferable.

The number average molecular weight and the weight average molecular weight can be measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve.

(Ratio of structural units)
The ratio of the structural unit D contained in the charge-transporting polymer is preferably 10 mol% or more, more preferably 20 mol% or more, and 30 mol% or more, based on all the structural units, from the viewpoint of obtaining sufficient charge transportability. Is more preferable. Further, the ratio of the structural unit D is preferably 95 mol% or less, more preferably 90 mol% or less, more preferably 85 mol% or less, based on all the structural units, in consideration of the structural unit M and the structural unit T to be introduced as needed. More preferably, it is mol% or less.

The ratio of the structural unit M contained in the charge-transporting polymer is based on all the structural units from the viewpoint of improving the characteristics of the organic electronic device or from the viewpoint of suppressing the increase in viscosity and satisfactorily synthesizing the charge-transporting polymer. 5 mol% or more is preferable, 10 mol% or more is more preferable, and 15 mol% or more is further preferable. The ratio of the structural unit M is preferably 60 mol% or less, more preferably 55 mol% or less, still more preferably 50 mol% or less, based on all structural units, from the viewpoint of obtaining sufficient charge transportability.

When the charge transporting polymer contains the structural unit T, the ratio of the structural unit T is preferably 1 mol% or more, more preferably 5 mol% or more, based on all the structural units, from the viewpoint of improving the durability of the organic electronic device. It is preferable, and 10 mol% or more is more preferable. The ratio of the structural unit T is 50 mol% or less based on all structural units from the viewpoint of suppressing an increase in viscosity and satisfactorily synthesizing a charge-transporting polymer or obtaining sufficient charge-transporting property. Is preferable, 40 mol% or less is more preferable, and 30 mol% or less is further preferable.

When the charge-transporting polymer has a polymerizable functional group, the ratio of the polymerizable functional group is preferably 0.1 mol% or more based on all structural units from the viewpoint of efficiently curing the charge-transporting polymer. 1 mol% or more is more preferable, and 3 mol% or more is further preferable. The proportion of the polymerizable functional group is preferably 70 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, based on all structural units, from the viewpoint of obtaining good charge transportability. .. The "ratio of polymerizable functional groups" here means the ratio of structural units having polymerizable functional groups.

Considering the balance of charge transportability, durability, productivity, etc., the ratio (molar ratio) of the structural unit D and the structural unit M is preferably D: M = 100: 1 to 70, more preferably 100: 3 to 50. It is preferable, and 100: 5 to 30 is more preferable. When the charge transporting polymer contains the structural unit T, the ratio (molar ratio) of the structural unit D, the structural unit M, and the structural unit T is D: M: T = 100: 10 to 200: 10 to 100. Preferably, 100: 20 to 180: 20 to 90 is more preferable, and 100: 40 to 160: 30 to 80 is even more preferable.

The ratio of the structural units can be determined by using the amount of the monomer charged corresponding to each structural unit used for synthesizing the charge-transporting polymer. Further, the ratio of the structural units can be calculated as an average value by using the integrated value of the spectrum derived from each structural unit in ^{the 1 H NMR spectrum of the charge transport polymer.} When the amount to be charged is clear, it is preferable to adopt the value obtained by using the amount to be charged because it is convenient.

(Production method)
The charge-transporting polymer can be produced by various synthetic methods and is not particularly limited. For example, known coupling reactions such as Suzuki coupling, Negishi coupling, Sonogashira coupling, Still coupling, and Buchwald-Hartwig coupling can be used. Suzuki coupling causes a Pd-catalyzed cross-coupling reaction between an aromatic boronic acid derivative and an aromatic halide. According to Suzuki Coupling, a charge-transporting polymer can be easily produced by binding desired aromatic rings to each other.

In the coupling reaction, for example, a Pd (0) compound, a Pd (II) compound, a Ni compound and the like are used as the catalyst. Further, a catalyst species generated by mixing tris (dibenzylideneacetone) dipalladium (0), palladium (II) acetate or the like as a precursor and mixing with a phosphine ligand can also be used. Regarding the method for synthesizing the charge-transporting polymer, for example, the description of International Publication No. 2010/1405553 can be incorporated.

(Charge transporting low molecular weight compound)
Hereinafter, the charge transporting low molecular weight compound will be described.
The charge-transporting low-molecular-weight compound is not particularly limited as long as it contains an atomic group capable of transporting charges. The charge transporting low molecular weight compound may have a polymerizable functional group. The charge-transporting low molecular weight compound preferably contains at least one unit selected from the group consisting of a unit containing an aromatic amine structure, a unit containing a carbazole structure, and a unit containing a thiophene structure.

(Structure of charge transporting low molecular weight compound)
Examples of the structure of the charge transporting low molecular weight compound include the following. “D” represents the structural unit D, and “M” represents the structural unit M. The structural unit D and the structural unit M are as described above.

The organic electronics material may contain only one type of charge transporting compound (including a charge transporting low molecular weight compound), or may contain two or more types.

When the organic electronics material contains an ionic compound and a charge transporting compound, the content of the ionic compound is 0.1% by mass or more based on the mass of the charge transporting compound from the viewpoint of film forming property. Is preferable, 0.2% by mass or more is more preferable, and 0.5% by mass or more is further preferable. The content of the ionic compound is preferably 50% by mass or less, more preferably 40% by mass or less, and 30% by mass or less, based on the mass of the charge transporting compound, from the viewpoint of the driving voltage of the organic electronics element. More preferred.

[solvent]
The organic electronics material may further contain a solvent. The solvent-containing organic electronics material is preferably used as an ink composition in the manufacture of organic electronics devices.

As the solvent, water, an organic solvent, or a mixed solvent thereof can be used. Examples of the organic solvent include alcohols such as methanol, ethanol and isopropyl alcohol; alkanes such as pentane, hexane and octane; cyclic alkanes such as cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, methicylene, tetraline and diphenylmethane; ethylene glycol. Alibo ethers such as dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, Aromatic ethers such as 4-methoxytoluene, 2,3-dimethylanisole and 2,4-dimethylanisole; aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate and n-butyl lactate; phenyl acetate and propionic acid Aromatic esters such as phenyl, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate; amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide; dimethylsulfoxide, tetrahydrofuran, acetone , Chloroform, methylene chloride and the like. Preferred are aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers and the like. As the solvent, a non-polar organic solvent is preferable.

The content of the solvent in the ionic compound can be determined in consideration of application to various coating methods. For example, the ionic compound preferably contains an amount of the solvent having a charge-transporting polymer ratio of 0.1% by mass or more with respect to the solvent, and preferably contains an amount of the solvent having an amount of 0.2% by mass or more. It is more preferable that the solvent is contained in an amount of 0.5% by mass or more. Further, the ionic compound preferably contains a solvent in an amount such that the ratio of the charge transport polymer to the solvent is 20% by mass or less, and more preferably 15% by mass or less. It is more preferable to contain the solvent in an amount of 10% by mass or less.

[Additive]
The organic electronics material may further contain an additive as an optional component. Additives include, for example, polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, antioxidants, oxidizing agents, reducing agents, surface modifiers, emulsifiers, defoamers, etc. Dispersants, surfactants and the like can be mentioned. Further, if necessary, a known polymerization initiator and dopant may be used together with the ionic compound as long as the effects of the ionic compound of the present embodiment described above (for example, heat resistance, device characteristics, etc.) are not impaired. ..

<Organic layer>
The organic layer of the present embodiment is obtained by polymerizing a layer formed by a coating method using the organic electronic material of the above-described embodiment or an ink composition containing the organic electronic material, and further, the formed layer. It is a layer that has been allowed to insolubilize. By using an organic electronic material containing a solvent, an organic layer can be satisfactorily formed by a coating method. Examples of the coating method include a spin coating method; a casting method; a dipping method; a letterpress printing, a concave plate printing, an offset printing, a flat plate printing, a letterpress reversal offset printing, a screen printing, a plate printing method such as gravure printing; an inkjet method and the like. Known methods such as a plateless printing method can be mentioned. When the organic layer is formed by the coating method, the organic layer (coating layer) obtained after coating may be dried using a hot plate or an oven to remove the solvent.

When the organic electronics material contains a charge-transporting compound having a polymerizable functional group, these polymerization reactions can be allowed to proceed by light irradiation, heat treatment, or the like to change the solubility of the organic layer. In organic electronics materials, ionic compounds can function as polymerization initiators. By stacking organic layers having different solubilities, it is possible to easily increase the number of layers of organic electronic devices. As for the method of forming the organic layer, for example, the description of International Publication No. 2010/1405553 can be incorporated.
When the organic electronics material contains a charge-transporting compound having a polymerizable functional group, the curability at a low temperature can be improved when the ink composition is prepared. In addition, good stacking of organic layers is possible, and when an organic electronic device is used, the life of the organic electronic device can be extended.

The thickness of the organic layer after drying or curing is preferably 0.1 nm or more, more preferably 1 nm or more, and further preferably 3 nm or more from the viewpoint of improving the efficiency of charge transport. The thickness of the organic layer is preferably 300 nm or less, more preferably 200 nm or less, and further preferably 100 nm or less from the viewpoint of reducing the electric resistance.

<Organic electronics element>
The organic electronic device of the present embodiment has at least the organic layer of the above-described embodiment. Examples of the organic electronics element include an organic EL element such as an organic light emitting diode (OLED), an organic photoelectric conversion element, and an organic transistor. The organic electronics device preferably has a structure in which an organic layer is arranged between at least a pair of electrodes.

[Organic EL element]
The organic EL device of the present embodiment has at least one or more organic layers of the above-described embodiment. The organic EL device usually includes a light emitting layer, an anode, a cathode, and a substrate, and if necessary, provides other functional layers such as a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer. I have. Each layer may be formed by a thin-film deposition method or a coating method. The organic EL device preferably has an organic layer as a light emitting layer or another functional layer, more preferably as a functional layer, and further preferably as at least one of a hole injection layer and a hole transport layer.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an organic EL device. The organic EL device shown in FIG. 1 is a multi-layered device, and has a substrate 8, an anode 2, a hole injection layer 3, a hole transport layer 6, a light emitting layer 1, an electron transport layer 7, an electron injection layer 5, and a cathode. It has a multi-layer structure in which 4 are laminated in this order. Note that FIG. 1 is an example, and the organic EL element of the present embodiment is not limited to this figure. In FIG. 1, the hole injection layer 3 is an organic layer formed by using the above-mentioned organic electronic material, but the organic EL device of the present embodiment is not limited to such a structure, and other organic layers may be used. , It may be an organic layer formed by using the above-mentioned organic electronic material. For example, it is preferable to include an organic layer formed by using the above-mentioned organic electronics material as at least one layer selected from the group consisting of a hole transport layer, a hole injection layer and a light emitting layer. Hereinafter, each layer will be described.

[Light emitting layer]
As the material used for the light emitting layer, a light emitting material such as a low molecular weight compound, a polymer, or a dendrimer can be used. Polymers are preferred because they are highly soluble in solvents and suitable for coating methods. Examples of the light emitting material include fluorescent materials, phosphorescent materials, thermal activated delayed fluorescent materials (TADF) and the like.

Low molecular weight compounds such as perylene, coumarin, rubrene, quinacridone, stilbene, dyes for dye lasers, aluminum complexes, and derivatives thereof as fluorescent materials; polyfluorene, polyphenylene, polyphenylene vinylene, polyvinylcarbazole, fluorene-benzothiazol copolymer , Fluorene-triphenylamine copolymers, polymers such as derivatives thereof; mixtures thereof and the like.

As the phosphorescent material, a metal complex containing a metal such as Ir or Pt can be used. Examples of the Ir complex include FIr (pic) (iridium (III) bis [(4,6-difluorophenyl) -pyridinate-N, C ² ] picolinate) that emits blue light, and Ir (ppy) _{3 that emits green light.} (Factris (2-phenylpyridine) iridium), exhibiting red luminescence (btp) ₂ Ir (acac) (bis [2- (2'-benzo [4,5-α] thienyl) pyridinate-N, C ³ ] Iridium (acetyl-acetonate)), Ir (piq) ₃ (tris (1-phenylisoquinoline) iridium) and the like can be mentioned. Examples of the Pt complex include PtOEP (2, 3, 7, 8, 12, 13, 17, 18-octaethyl-21H, 23H-forfin platinum) that emits red light.

When the light emitting layer contains a phosphorescent material, it is preferable to further contain a host material in addition to the phosphorescent material. As the host material, a low molecular weight compound, a polymer, or a dendrimer can be used. Examples of low molecular weight compounds include CBP (4,4'-bis (9H-carbazole-9-yl) biphenyl), mCP (1,3-bis (9-carbazolyl) benzene), and CDBP (4,4'-. Bis (carbazole-9-yl) -2,2'-dimethylbiphenyl), derivatives thereof and the like, and as the polymer, the organic electronics material of the above-described embodiment, polyvinylcarbazole, polyphenylene, polyfluorene, derivatives thereof and the like can be used. Can be mentioned.

Examples of thermally activated delayed fluorescent materials include Adv. Mater., 21, 4802-4906 (2009); Appl. Phys. Lett., 98, 083302 (2011); Chem. Comm., 48, 9580 (2012). Appl. Phys. Lett., 101, 093306 (2012); J. Am. Chem. Soc., 134, 14706 (2012); Chem. Comm., 48, 11392 (2012); Nature, 492, 234 (2012) ); Adv. Mater., 25, 3319 (2013); J. Phys. Chem. A, 117, 5607 (2013); Phys. Chem. Chem. Phys., 15, 15850 (2013); Chem. Comm., 49, 10385 (2013); Chem. Lett., 43, 319 (2014), etc. can be used.

[Hole transport layer, hole injection layer]
The above-mentioned organic layer is preferably used as at least one of the hole injection layer and the hole transport layer, and more preferably at least as the hole transport layer. When the organic EL device has the above-mentioned organic layer as a hole transport layer and further has a hole injection layer, a known material can be used for the hole injection layer. Further, when the above-mentioned organic layer is provided as a hole injection layer and further has a hole transport layer, a known material can be used for the hole transport layer.

Examples of materials that can be used for the hole injection layer and the hole transport layer include aromatic amine compounds, phthalocyanine compounds, and thiophene compounds.

[Electron transport layer, electron injection layer]
Examples of the material used for the electron transport layer and the electron injection layer include fused ring tetracarboxylic acid anhydrides such as phenanthroline derivative, bipyridine derivative, nitro-substituted fluorene derivative, diphenylquinone derivative, thiopyrandioxide derivative, naphthalene and perylene, and carbodiimide. , Fluolenilidene methane derivative, anthraquinodimethane and antron derivative, oxadiazole derivative, thiadiazole derivative, benzoimidazole derivative, quinoxalin derivative, aluminum complex (for example, BAlq, Alq ₃ ) and the like. Further, the organic electronic material of the above-described embodiment can also be used.

[cathode]
As the cathode material, for example, a metal or a metal alloy such as Li, Ca, Mg, Al, In, Cs, Ba, Mg / Ag, LiF, CsF is used.

[anode]
As the anode material, for example, a metal (for example, Au) or another conductive material is used. Other materials include, for example, oxides (eg, ITO), conductive polymers (eg, polythiophene-polystyrene sulfonic acid mixture (PEDOT: PSS)).

[substrate]
Glass, plastic, etc. can be used as the substrate. The substrate is preferably transparent and preferably has flexibility. Quartz glass, light-transmitting resin film and the like are preferably used.

As the resin film, for example, a film containing polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, cellulose acetate propionate and the like. Can be mentioned.

When a resin film is used, the resin film may be coated with an inorganic substance such as silicon oxide or silicon nitride in order to suppress the permeation of water vapor, oxygen, etc.

[Emission color]
The emission color of the organic EL element is not particularly limited. An organic EL element exhibiting white light emission (also referred to as a white organic EL element) is preferable because it can be used for various lighting fixtures such as household lighting, vehicle interior lighting, clocks, and liquid crystal backlights.

As a method for forming the white organic EL element, a method of simultaneously emitting a plurality of emission colors using a plurality of light emitting materials and mixing the colors can be used. The combination of a plurality of emission colors is not particularly limited, but for example, a combination containing three emission maximum wavelengths of blue, green and red, and a complementary color relationship such as blue and yellow and yellow-green and orange. Examples thereof include a combination containing the two maximum emission wavelengths used. The emission color can be controlled by adjusting the type and amount of the emission material.

<Display element, lighting device, display device>
The display element of the present embodiment includes the organic EL element of the above-described embodiment. For example, by using an organic EL element as an element corresponding to each pixel of red, green, and blue (RGB), a color display element can be obtained. There are two methods for forming an image: a simple matrix type in which individual organic EL elements arranged on a panel are directly driven by electrodes arranged in a matrix, and an active matrix type in which a thin film transistor is arranged and driven in each element.

Further, the lighting device of the present embodiment includes the organic EL element of the above-described embodiment. Further, the display device of the present embodiment includes a lighting device and a liquid crystal element as a display means. For example, the display device can be a display device using the lighting device of the above-described embodiment as a backlight and a known liquid crystal element as a display means, that is, a liquid crystal display device.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Example 1]
(Synthesis of Ionic Compound 1)
Ionic compound 1 having the following structure was synthesized as follows.
25 g of acetone and 5 g of pure water were added to 1.111 g (10 mmol) of diallyl methylamine and stirred to obtain a uniform solution, and then 3.653 g of a 10% hydrogen chloride aqueous solution was slowly added dropwise, and the mixture was stirred for 1 hour after the completion of the addition. The solvent was distilled off from this solution under reduced pressure. Then, 77.49 g (11 mmol) of a 10% aqueous solution of Sodium tetrakis (pentafluorophenyl) borate was mixed, and the mixture was stirred for 1 hour. This was washed with water 5 times and dried to prepare a white solid.

[Example 2]
(Synthesis of Ionic Compound 2)
Ionic compound 2 having the following structure was synthesized as follows.
To 1.132 g (10 mmol) of diethylallylamine, 25 g of acetone and 5 g of pure water were added and stirred to obtain a uniform solution, and then 3.653 g of a 10% hydrogen chloride aqueous solution was slowly added dropwise, and the mixture was stirred for 1 hour after the completion of the addition. The solvent was distilled off from this solution under reduced pressure. Then, 77.49 g (11 mmol) of a 10% aqueous solution of Sodium tetrakis (pentafluorophenyl) borate was mixed, and the mixture was stirred for 1 hour. This was washed with water 5 times and dried to prepare a white solid.

[Example 3]
(Synthesis of Ionic Compound 3)
The ionic compound 3 having the following structure was synthesized as follows.
To 1.372 g (10 mmol) of triallylamine, 25 g of acetone and 5 g of pure water were added and stirred to obtain a uniform solution, and then 3.653 g of a 10% hydrogen chloride aqueous solution was slowly added dropwise, and the mixture was stirred for 1 hour after the completion of the addition. The solvent was distilled off from this solution under reduced pressure. Then, 77.49 g (11 mmol) of a 10% aqueous solution of Sodium tetrakis (pentafluorophenyl) borate was mixed, and the mixture was stirred for 1 hour. This was washed with water 5 times and dried to prepare a white solid.

[Comparative Example 1]
(Synthesis of Ionic Compound 4)
The ionic compound 4 having the following structure was synthesized as follows.
To 2.986 g (10 mmol) of N, N-dimethyloctadecylamine, 25 g of acetone and 5 g of pure water were added and stirred to make a uniform solution, then 3.653 g of a 10% hydrogen chloride aqueous solution was slowly added dropwise, and the mixture was stirred for 1 hour after the addition was completed. did. The solvent was distilled off from this solution under reduced pressure. Then, 77.49 g (11 mmol) of a 10% aqueous solution of Sodium tetrakis (pentafluorophenyl) borate was mixed, and the mixture was stirred for 1 hour. This was washed with water 5 times and dried to prepare a white solid.

[Comparative Example 2]
(Synthesis of Ionic Compound 5)
The ionic compound 5 having the following structure was synthesized as follows.
To 3.126 g (10 mmol) of N, N-didecanomethylamine, 25 g of acetone and 5 g of pure water were added and stirred to make a uniform solution, and then 3.653 g of a 10% hydrogen chloride aqueous solution was slowly added dropwise, and 1 hour after the completion of the addition. Stirred. The solvent was distilled off from this solution under reduced pressure. Then, 77.49 g (11 mmol) of a 10% aqueous solution of Sodium tetrakis (pentafluorophenyl) borate was mixed, and the mixture was stirred for 1 hour. This was washed with water 5 times and dried to prepare a white solid.

[Comparative Example 3]
(Synthesis of Ionic Compound 6)
The ionic compound 6 having the following structure was synthesized as follows.
To 5.220 g (10 mmol) of tridodecanoamine, 25 g of acetone and 5 g of pure water were added and stirred to obtain a uniform solution, and then 3.653 g of a 10% hydrogen chloride aqueous solution was slowly added dropwise, and the mixture was stirred for 1 hour after the completion of the addition. The solvent was distilled off from this solution under reduced pressure. Then, 77.49 g (11 mmol) of a 10% aqueous solution of Sodium tetrakis (pentafluorophenyl) borate was mixed, and the mixture was stirred for 1 hour. This was washed with water 5 times and dried to prepare a white solid.

[Comparative Example 4]
(Synthesis of Ionic Compound 7)
The ionic compound 7 having the following structure was synthesized as follows.
To 2.274 g (10 mmol) of trypentylamine, 25 g of acetone and 5 g of pure water were added and stirred to obtain a uniform solution, and then 3.653 g of a 10% hydrogen chloride aqueous solution was slowly added dropwise, and the mixture was stirred for 1 hour after the completion of the addition. The solvent was distilled off from this solution under reduced pressure. Then, 77.49 g (11 mmol) of a 10% aqueous solution of Sodium tetrakis (pentafluorophenyl) borate was mixed, and the mixture was stirred for 1 hour. This was washed with water 5 times and dried to prepare a white solid.

[Measurement of weight loss temperature]
The thermogravimetric reduction was determined by measuring 10 mg of each of the produced ionic compounds in air using a TG-DTA measuring device (DTG-60H manufactured by Shimadzu Corporation) under a temperature rising condition of 5 ° C./min. The temperature at which the weight loss of 2% occurred when each ionic compound was heated was defined as the weight loss temperature. Table 1 shows the evaluation results of the weight loss temperature.

The ionic compounds 1 to 3 (Examples 1 to 3) in the above-described embodiment showed higher weight loss temperatures than the ionic compounds 4 to 7 (Comparative Examples 1 to 4). It can be seen that the heat resistance is excellent by using an ionic compound having a small thermal weight loss.

<Preparation of charge-transporting polymer>
[Preparation of Pd catalyst]
Tris (dibenzylideneacetone) dipalladium (73.2 mg, 80 μmol) was weighed in a sample tube at room temperature in a glove box under a nitrogen atmosphere, toluene (15 mL) was added, and the mixture was stirred for 30 minutes. Similarly, tris (t-butyl) phosphine (129.6 mg, 640 μmol) was weighed into a sample tube, toluene (5 mL) was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at room temperature for 30 minutes to obtain a catalyst solution (hereinafter referred to as "Pd catalyst solution"). In the preparation of the Pd catalyst, all solvents were used after degassing with nitrogen bubbles for at least 30 minutes.

[Preparation of charge-transporting polymer]
A charge-transporting polymer 1 was prepared as shown below. The monomers used are shown below.

(Preparation of Charge Transport Polymer 1)
Monomer A (5.0 mmol), Monomer B (2.0 mmol), Monomer C (3.4 mmol), Monomer D (0.6 mmol), Methyltri-n-octylammonium chloride (manufactured by Alfa Aesar) in a three-necked round-bottom flask. "Aliquot 336") (0.04 g), 3M aqueous potassium hydroxide solution (7.79 g), and toluene (53 mL) were added, and the Pd catalyst solution (1.0 mL) prepared above was further added and mixed. .. The resulting mixture was heated to reflux for 2 hours. All operations up to this point were performed under a nitrogen stream. In addition, all the solvents were used after being degassed by nitrogen bubbles for 30 minutes or more.

After completion of the reaction, the organic layer was washed with water, and the organic layer was poured into methanol-water (9: 1). The resulting precipitate was collected by suction filtration and washed with methanol-water (9: 1). The resulting precipitate was dissolved in anisole, poured into methanol and reprecipitated. The obtained precipitate was collected by suction filtration, dissolved in anisole, and a metal adsorbent (“Triphenylphosphine, polymerase-bound on styrene-divinylbenzene copolymer” manufactured by Strem Chemicals, 200 mg with respect to 100 mg of the precipitate) was added to 80. The mixture was stirred at ° C. for 2 hours. After the stirring was completed, the metal adsorbent and the insoluble matter were removed by filtration, and then poured into methanol for reprecipitation. The resulting precipitate was collected by suction filtration and washed with methanol. The obtained precipitate was vacuum dried to prepare a charge-transporting polymer 1. The charge-transporting polymer 1 had a number average molecular weight of 11,900 and a weight average molecular weight of 66,200.

The number average molecular weight and the weight average molecular weight were measured by GPC (polystyrene conversion) using tetrahydrofuran (THF) as an eluent. The measurement conditions are as follows.
Equipment: High Performance Liquid Chromatograph Prominence Shimadzu Corporation Liquid Transfer Pump (LC-20AD)
Degassing unit (DGU-20A)
Autosampler (SIL-20AHT)
Column oven (CTO-20A)
PDA detector (SPD-M20A)
Differential Refractometer Detector (RID-20A)
Column: Gelpack®
GL-A160S (serial number: 686-1J27)
GL-A150S (serial number: 685-1J27) Hitachi Kasei Co., Ltd. Eluent: tetrahydrofuran (THF) (for HPLC, containing stabilizer) Fujifilm Wako Pure Chemical Industries, Ltd. Flow velocity: 1 mL / min
Column temperature: 40 ° C
Detection wavelength: 254 nm
Molecular weight standard substance: PStQuick A / B / C Tosoh Corporation

[Solvent resistance evaluation]
Organic layers A1 to 7 were formed using the charge-transporting polymer 1 and the ionic compounds 1 to 7, and the solvent resistance was evaluated by measuring the residual film ratio.

(Measurement of residual film ratio)
The ionic compound (10 mg) used in Example 1 was weighed into a 20 mL screw tube, a certain amount of chlorobenzene was added, and the mixture was stirred to prepare an ionic compound solution. Then, the charge-transporting polymer 1 (10 mg) and a certain amount of chlorobenzene (792 μL) were added to the 9 mL screw tube to dissolve the charge-transporting polymer. Then, a certain amount of the ionic compound solution was added to the above-mentioned 9 mL screw tube and stirred to prepare an ink composition. The ink composition is filtered through a polytetrafluoroethylene (PTFE) filter (pore diameter 0.2 μm), dropped onto a quartz substrate (length 22 mm × width 29 mm × thickness 0.7 mm), and a coating film is formed by a spin coater. Membrane. Subsequently, heat curing was carried out at 200 ° C. for 30 minutes in a nitrogen atmosphere to form an organic layer having a film thickness of 30 nm on a quartz substrate. (The solution was adjusted so that the charge-transporting polymer was 1 wt% and the ionic compound was 1 wt% with respect to the charge-transporting polymer.)

The absorbance A of the organic layer formed on the quartz substrate was measured using a spectrophotometer (“UV-2700” manufactured by Shimadzu Corporation). Subsequently, the mixture was immersed in anisole (10 mL, 25 ° C.) for 10 minutes in an environment of 25 ° C. so that the organic layer after measurement was on the upper surface. The absorbance B of the organic layer after immersion in anisole was measured, and the residual film ratio was calculated from the absorbance A of the formed organic layer and the absorbance B of the organic layer after immersion in anisole using the following formula. As the value of absorbance, the value at the maximum absorption wavelength of the organic layer was used. The larger the residual film ratio, the better the solvent resistance.

[Number 1]
Residual film ratio (%) = (absorbance B / absorbance A) x 100

Table 2 shows the measurement results of the residual film ratio.

The organic layers A1 to A3 using the ionic compounds 1 to 3 of the present embodiment have a better residual film ratio and a film forming property as compared with the organic layers A4 to A7 using the ionic compounds 4 to 7. Good measurement results were shown.

[Evaluation of element characteristics]
Organic EL devices 1 to 7 were prepared using the charge-transporting polymer 1 and the ionic compounds 1 to 7 according to the following, and the drive voltage, luminous efficiency, and emission lifetime were evaluated.

(Manufacturing of organic EL element)
The ionic compound (10.0 mg) used in Example 1 was weighed into a 20 mL screw tube, a certain amount of chlorobenzene was added, and the mixture was stirred to prepare an ionic compound solution. Then, a charge-transporting polymer (10 mg) and a certain amount of chlorobenzene were added to the 9 mL screw tube to dissolve the charge-transporting polymer. Then, a certain amount of the ionic compound solution was added to the above-mentioned 9 mL screw tube and stirred to prepare an ink composition. A patterned ITO having a width of 1.6 mm is formed on a glass substrate (length 22 mm × width 29 mm × thickness 0.7 mm), and an ink composition is applied onto the glass substrate and the formed ITO with a polytetrafluoroethylene (PTFE) filter (PTFE). The filtrate prepared by filtering with a pore size of 0.2 μm) was dropped, and a coating film was formed by a spin coater. Then, it was heated on a hot plate at 200 ° C. for 30 minutes in a nitrogen atmosphere to form a hole injection layer (30 nm). (The solution was adjusted so that the charge-transporting polymer was 1 wt% and the ionic compound was 1 wt% with respect to the charge-transporting polymer.)

The glass substrate having the hole injection layer is transferred into the vacuum vapor deposition machine, and α-NPD (40 nm), CBP: Ir (ppy) ₃ (94: 6, 30 nm), BAlq (10 nm), TPBi are placed on the hole injection layer. (30 nm), LiF (0.8 nm), and Al (100 nm) were deposited in this order by a vapor deposition method. Then, a sealing process was performed to produce an organic EL element.

(Evaluation of organic EL element)
When a voltage was applied to the organic EL element, green light emission was confirmed. For each of the organic EL device, the driving voltage of the light emitting luminance 5,000 cd / ^{m 2,} and luminescence was measured lifetime (luminance half-life) in the luminous efficiency, and the initial emission luminance 5,000 cd / ^{m 2.}

Table 3 shows the measurement results of drive voltage, luminous efficiency, and luminous life.

The organic EL devices 1 to 3 using the ionic compounds 1 to 3 of the present embodiment are compared with the organic EL devices 4 to 7 using the ionic compounds 4 to 7 in terms of drive voltage, light emission efficiency, and light emission lifetime. Good measurement results were shown.

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

Claims

An ionic compound containing an ammonium cation and an anion represented by the following formula (1a).

(In formula (1a), Ra , R b and R c each independently represent a hydrogen atom or a monovalent organic group, and at least two selected from Ra , R b and R c are monovalent. It is an organic group, and at least one selected from Ra , R b and R c is an organic group containing a double bond.)
The ionic compound according to claim 1, wherein the organic group containing the double bond has 2 to 6 carbon atoms.
The ionic compound according to claim 1 or 2, wherein the double bond is located at the end of the organic group.
The ionic compound according to any one of claims 1 to 3, wherein the organic group in each of R a , R b and R c has 4 or less carbon atoms.
The method according to any one of claims 1 to 4, wherein the organic group containing the double bond is one selected from the group consisting of a vinyl group, a propenyl group, an isopropenyl group, a butenyl group, and an isobutenyl group. Ionic compounds according to.
The ionic compound according to any one of claims 1 to 5, which contains only one organic group containing the double bond.
Containing two or more organic groups containing the double bond,
The ionic compound according to any one of claims 1 to 5, wherein each of the organic groups containing a double bond is the same as each other.
The ionic compound according to any one of claims 1 to 7, wherein the anion is represented by any of the following formulas (1b) to (5b).

(In equations (1b) to (5b),
E 1 represents an oxygen atom, E 2 represents a nitrogen atom, E 3 represents a carbon atom, E 4 represents a boron atom or a gallium atom, and E 5 represents a phosphorus atom or an antimony atom.
Y 1 to Y 6 independently represent a single bond or a divalent linking group, respectively.
R 1 to R 16 are at least two groups independently selected from electron-attracting monovalent groups (R 2 and R 3 , R 4 to R 6 and at least R 7 to R 10). The two groups and at least two groups selected from R 11 to R 16 may each be attached to each other). )
An organic electronics material containing the ionic compound and the charge transporting compound according to any one of claims 1 to 8.
The organic electronics according to claim 9, wherein the charge transporting compound has at least one unit selected from the group consisting of a unit containing an aromatic amine structure, a unit containing a carbazole structure, and a unit containing a thiophene structure. material.
The organic electronic material according to claim 9 or 10, wherein the charge-transporting compound has one or more polymerizable functional groups in the molecule.
The organic electronics material according to claim 11, wherein the polymerizable functional group contains at least one selected from the group consisting of an oxetane group, an epoxy group, and a vinyl ether group.
The organic electronic material according to any one of claims 9 to 12, further containing a solvent.
An organic layer formed by using the organic electronic material according to any one of claims 9 to 13.
An organic electronic device provided with the organic layer according to claim 14.
The organic electronic device according to claim 15, further comprising another organic layer on the organic layer.
The organic electronic device according to claim 15 or 16, further comprising a substrate, wherein the substrate has flexibility.
The organic electronic device according to claim 15 or 16, further comprising a substrate, wherein the substrate is a resin film.
An organic electroluminescence device provided with the organic layer according to claim 14.
The organic electroluminescence device according to claim 19, wherein the organic layer is a hole injection layer.
The organic electroluminescence device according to claim 19, wherein the organic layer is a hole transport layer.
The organic electroluminescence device according to claim 19, wherein the organic layer is a light emitting layer.
The organic electroluminescence device according to any one of claims 19 to 22, which has a white emission color.
The organic electroluminescence device according to any one of claims 19 to 23, further comprising a substrate, wherein the substrate has flexibility.
The organic electroluminescence device according to any one of claims 19 to 23, further comprising a substrate, wherein the substrate is a resin film.
A display device including the organic electroluminescence device according to any one of claims 19 to 25.
A lighting device provided with the organic electroluminescence element according to any one of claims 19 to 25.
A display element including the lighting device according to claim 27 and a liquid crystal element as a display means.
A method for manufacturing an organic electronic device, which comprises a step of forming an organic layer by a coating method using the organic electronic material according to claim 13.