JP7444170B2 - Ionic compound, organic electronic material, organic layer, organic electronic device, organic electroluminescent device, display device, lighting device, and method for producing an organic electronic device - Google Patents

Description

Embodiments of the present invention relate to ionic compounds, organic electronic materials, organic layers, organic electronic devices, organic electroluminescent devices, display devices, lighting devices, and methods of manufacturing organic electronic devices.

Organic electronic devices are devices that operate electrically using organic materials, and are expected to exhibit features such as energy saving, low cost, and flexibility, and are attracting attention as a technology that can replace conventional silicon-based inorganic semiconductors. has been done.

Examples of organic electronic devices include organic electroluminescent 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 a substitute for incandescent lamps, gas-filled lamps, and the like, and as a large-area solid-state light source. It is also attracting attention as the most promising self-luminous display to replace liquid crystal displays (LCDs) in the flat panel display (FPD) field, and its commercialization is progressing.

Organic EL devices are broadly classified into two types, low molecular type organic EL devices and high molecular type organic EL devices, based on the organic materials used. In a polymer type organic EL element, a polymer material is used as an organic material, and in a low molecule type organic EL element, a low molecule material is used. Compared to low-molecular-weight organic EL devices, which are mainly formed in a vacuum system, polymer-type organic EL devices can be easily formed using wet processes such as printing and inkjet, so they can be used for large-screen organic EL devices in the future. It is expected to be an essential element for EL displays.

For this reason, efforts are being made to develop materials suitable for wet processes.

Japanese Patent Application Publication No. 2006-279007 International Publication No. 2010/140553

In general, organic EL devices manufactured by wet processes using polymer materials have the advantage of being easy to reduce cost and increase in area. However, organic EL devices including thin films made using conventional polymeric materials are desired to be further improved in their characteristics, such as driving voltage, luminous efficiency, and luminous lifetime. Furthermore, since high-temperature baking is required in the process of drying the solvent to produce an organic EL element, each material is desired to have high-temperature process resistance.

The present invention has been made in view of the above, and embodiments of the present invention provide an organic electronics material that can be used for organic electronic elements with excellent device characteristics, and an organic electronics material that can be used for the organic electronics material and has excellent heat resistance. The purpose of the present invention is to provide an ionic compound that has the following properties. Further, other embodiments aim to provide an organic layer using the organic electronic material, and an organic electronic device, an organic electroluminescent device, a display device, 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 anion represented by the following formula (1a).

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

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

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

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

Further, another embodiment of the present invention relates to an organic electroluminescent device including the organic layer.

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

Further, another embodiment of the present invention relates to a lighting device including the organic electroluminescent 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 device, including a step of forming an organic layer by a coating method using the organic electronic material.

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

1 is a schematic cross-sectional view showing an example of an organic EL element that is an embodiment of the present invention.

Hereinafter, ionic compounds, organic electronic materials, organic layers, organic electronic elements, organic electroluminescent elements, display elements, and lighting devices according to embodiments of the present invention will be described in detail.

Embodiments of the invention are as follows.

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

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

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

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

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

<5> The double bond-containing organic group 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. 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> According to any one of <1> to <5>, the organic group contains two or more double bond-containing organic groups, and each of the double bond-containing organic groups is the same as each other. The ionic compound described in .

<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 is an oxygen atom, E ² is a nitrogen atom, E ³ is a carbon atom, E ⁴ is a boron atom or a gallium atom, E ⁵ is a phosphorus atom or an antimony atom, and Y ¹ ~Y ⁶ each independently represents a single bond or a divalent linking group, and R ¹ ~ R ¹⁶ each independently represents an electron-withdrawing monovalent group (R ² and R ³ , R ⁴ ~ 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 may each be bonded to each other.) represents.

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

<10> The charge transport 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 electronic 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 electronics material according to <11>, wherein the polymerizable functional group includes at least one selected from the group consisting of an oxetane group, an epoxy group, and a vinyl ether group.

<13> The organic electronics material according to any one of <9> to <12>, further containing a solvent.

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

<15> An organic electronics device comprising the organic layer according to <14>.

<16> The organic electronics device according to <15>, further comprising another organic layer on the organic layer.

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

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

<19> An organic electroluminescent device comprising the organic layer according to <14>.

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

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

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

<23> The organic electroluminescent device according to any one of <19> to <22>, wherein the emitted light color is white.

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

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

<26> A display element comprising the organic electroluminescent element according to any one of <19> to <25>.

<27> A lighting device comprising the organic electroluminescent element according to any one of <19> to <25>.

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

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

<Ionic compound>
The ionic compound of this embodiment consists of an ammonium cation and an anion represented by the following formula described below. Hereinafter, ammonium cations and anions will be explained. The ionic compound of this embodiment is preferably used as a dopant for organic electronics materials. Further, when the charge transporting polymer contains a polymerizable functional group, the ionic compound of this 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), R ^a , R ^b and R ^c each independently represent a hydrogen atom or a monovalent organic group, and at least two selected from R ^a , R ^b and R ^c are monovalent organic groups. 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. Moreover, at least one selected from R ^a , 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.

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

Specific examples of R ^a , R ^b and R ^c will be explained, but they are 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 methyl group, ethyl group, propyl group, i-propyl group, butyl group, i-butyl group, t-butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, 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 carbon atoms, more preferably 2 to 8 carbon atoms, and still more preferably 2 to 6 carbon atoms. Specific examples of alkenyl groups include vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-octenyl group, 1-decenyl group, Examples include 1-octadecenyl group.

The alkynyl group may be linear, branched, or cyclic, and may have a substituent. The alkynyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, and still more preferably 2 to 6 carbon atoms. Specific examples of alkynyl groups include ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-octynyl group, 1-decynyl group, 1-octadecynyl group. etc.

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 unsubstituted monovalent aryl group preferably has 6 to 60 carbon atoms, more preferably 6 to 30 carbon atoms, and still more preferably 6 to 18 carbon atoms. Specifically, phenyl group, C1 to C12 alkoxyphenyl group (C1 to C12 indicates that the substituent has 1 to 12 carbon atoms. The same applies below), C1 to C12 alkylphenyl group, Examples include 1-naphthyl group, 2-naphthyl group, 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, phenanthren-yl group, pyren-yl group, perylene-yl group, and pentafluorophenyl group.

Specific examples of C1 to 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.

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 unsubstituted monovalent heteroaryl group preferably has 4 to 60 carbon atoms, more preferably 4 to 40 carbon atoms, and still more preferably 4 to 20 carbon atoms. Specific examples include thienyl group, C1-C12 alkylthienyl group, pyrrolyl group, furyl group, pyridyl group, C1-C12 alkylpyridyl group, etc. A C12 alkylpyridyl group is preferred. Examples of C1-C12 alkyl are as described above.

The arylalkyl group is an alkyl group in which at least one hydrogen atom 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 unsubstituted monovalent arylalkyl group preferably has 7 to 19 carbon atoms, more preferably 7 to 16 carbon atoms, and still more preferably 7 to 13 carbon atoms. Examples of the alkyl group include the aforementioned alkyl groups, and examples of the aryl group include the aforementioned aryl groups. Specific examples include benzyl group, phenethyl group, naphthylmethyl group, naphthylethyl group, diphenylmethyl group, and the like.

In 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 this embodiment can be easily produced, and the organic electronic device containing the ammonium cation can be prepared by: Excellent device characteristics such as driving voltage, luminous efficiency, and luminous lifetime can be obtained.

Generally, by increasing the number of carbon atoms (e.g., 5 or more carbon atoms) of the substituent of the ammonium cation (corresponding to R ^a , R ^b , R ^c , etc. in the ammonium cation of the ionic compound of this embodiment), it is possible to We are investigating ways to improve the solubility of ionic compounds and the heat resistance of ionic compounds. On the other hand, in the ammonium cation of the ionic compound of the present embodiment, at least one selected from R ^a , R ^b , and R ^c is an organic group containing a double bond; Crosslinking stabilizes ammonium cations, which is thought to improve the heat resistance of the ionic compound.

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

Further, the double bond is preferably located at the end 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. etc.

When the ammonium cation of the ionic compound of this embodiment contains two or more double bond-containing organic groups, from the viewpoint of ease of manufacture, each of the double bond-containing organic groups is the same as the other. It is preferable.

(anion)
The anion is not particularly limited, and for example, known anions can be used. The anions represented by the following formulas (1b), (2b), (3b), (4b) or (5b) drive the organic electronics element for a long time, and further reduce the driving voltage of the organic electronics element. preferred.

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,
Y ¹ to Y ⁶ each independently represent a single bond or a divalent linking group,
R ¹ to R ¹⁶ each independently represent an electron-withdrawing monovalent group (R ² and R ³ , at least two groups selected from R ⁴ to R ⁶ , at least two groups selected from R ⁷ to R ¹⁰ ); The two groups and at least two groups selected from R ¹¹ to R ¹⁶ may each be bonded to each other.

In formulas (1b) to (5b), R ¹ to R ¹⁶ each independently represent an electron-withdrawing monovalent group. An electron-withdrawing monovalent group refers to a substituent that more easily attracts electrons from the bonding atom side than a hydrogen atom. R ¹ to R ¹⁶ are preferably organic groups. R ² and R ³ , at least two groups selected from 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 are , may be connected to each other. The bonded group may be cyclic.

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

Furthermore, as an example of an electron-withdrawing monovalent group, from the viewpoint of efficiently delocalizing negative charges, an "organic group having a hydrogen atom" among the above-mentioned examples of the electron-withdrawing monovalent group is used. Preferred examples include groups in which some or all of the hydrogen atoms are substituted with halogen atoms. For example, perfluoroalkylsulfonyl group, perfluoroarylsulfonyl group, perfluoroalkyloxysulfonyl group, perfluoroaryloxysulfonyl group, perfluoroacyl group, perfluoroacyloxy group, perfluoroalkoxycarbonyl group, perfluoroaryloxycarbonyl group , perfluoroalkyl group, perfluoroalkenyl group, perfluoroalkynyl group, perfluoroaryl group, perfluoroarylalkyl group, and the like.

Examples of electron-withdrawing monovalent groups include linear or branched perfluoroalkyl groups having 1 to 8 carbon atoms, cyclic perfluoroalkyl groups having 3 to 6 carbon atoms, or carbon Perfluoroaryl groups having numbers 6 to 18 are preferred.

The electron-withdrawing monovalent group is not limited to these. The electron-withdrawing monovalent group shown above may have a substituent or a heteroatom.

Specific examples of the electron-withdrawing monovalent group include groups shown in substituent group (1) below. In addition, in this specification etc., "*" in a structural formula represents the bonding site with another structural unit.

Substituent group (1)

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

In formulas (7c) to (11c), R each independently represents a hydrogen atom or a monovalent group, and is preferably an organic group. From the viewpoint of improving electron acceptability, solubility in a solvent, etc., each R is preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heteroaryl group. These groups may have a substituent or a heteroatom. Further, R is preferably an electron-withdrawing monovalent group, and examples of the electron-withdrawing monovalent group include the aforementioned alkyl group, alkenyl group, alkynyl group, aryl group, and heteroaryl group. , or the groups shown in the substituent group (1).

The ionic compound of this embodiment has excellent heat resistance and can be used for organic electronic devices. Furthermore, when used together with a charge transporting compound having a polymerizable functional group, which will be described later, it is possible to improve curability at low temperatures and improve film formability.

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

[Charge transporting compound]
The organic electronic material may contain a charge transporting compound. The charge transporting compound may be a low-molecular compound or a polymer. From the viewpoint of solubility in organic solvents, polymers are preferred, and from the viewpoint of ease of purification by sublimation, recrystallization, etc., low molecular weight compounds are preferred. "Polymer" includes oligomers with a low degree of polymerization (for example, number average degree of polymerization is 2 or more and 20 or less) and polymers with high degree of polymerization (for example, number average degree of polymerization is more than 20). The charge transporting compound may be a commercially available compound or one 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 within the molecule. Although the polymerizable functional group is not particularly limited, 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, when an ink composition is made of an organic electronics material containing this charge transporting compound and the ionic compound of the above embodiment, curability at low temperatures is improved. As a result, film formation properties at low temperatures can be improved.

(charge transporting polymer)
The charge transporting polymer will be explained below.
Charge transporting polymers have the ability to transport charge. The charge transporting polymer may be linear or may have a branched structure. The charge-transporting polymer preferably includes at least a divalent structural unit D having charge-transporting properties and a monovalent structural unit M constituting a terminal part, and a trivalent or higher valent structural unit T constituting a branch part. It may further contain. The charge transporting polymer may contain only one type of each structural unit, or may contain multiple types of each structural unit. The structural units are bonded to each other at "monovalent" to "trivalent or higher" binding sites.

(Structure of charge transporting polymer)
Examples of partial structures contained in the charge transporting polymer include the following. The charge transporting polymer is not limited to those having the following partial structure. 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 bonding site with another structural unit. In the following partial structures, a plurality of D's may be the same structural unit or different structural units. The same applies to M and T.

Linear charge transporting polymer

Charge-transporting polymer with branched structure

(structural unit D)
Structural unit D is a divalent structural unit having charge transport properties. The structural unit D is not particularly limited as long as it contains an atomic group having the ability to transport charges. For example, the structural unit D may be 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, dihydrocarbon Phenanthrene structure, pyridine structure, pyrazine structure, quinoline structure, isoquinoline structure, quinoxaline structure, acridine structure, diazaphenanthrene structure, furan structure, pyrrole structure, oxazole structure, oxadiazole structure, thiazole structure, thiadiazole structure, triazole structure, benzo It is selected from a thiophene structure, a benzoxazole structure, a benzoxadiazole structure, a benzothiazole structure, a benzothiadiazole 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 this embodiment, the structural unit D includes a substituted or unsubstituted aromatic amine structure, a carbazole structure, a thiophene structure, a fluorene structure, a benzene structure, a pyrrole structure, and these structures, from the viewpoint of obtaining excellent hole transport properties. The structure is preferably selected from a structure containing one or more of these, and is preferably selected 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 that From the viewpoint of obtaining excellent electron transport properties, the structural unit D is a substituted or unsubstituted fluorene structure, benzene structure, phenanthrene structure, pyridine structure, quinoline structure, or a structure containing one or more of these. Preferably selected.

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

Each R independently represents a hydrogen atom or a substituent. When R is a substituent, the substituents each independently include -R ¹ , -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ , a halogen atom, and It is preferably selected from the group consisting of groups containing a polymerizable functional group described below. R ¹ to R ⁸ each independently represent a hydrogen atom; a linear, cyclic, or branched alkyl group having 1 to 22 carbon atoms; or an aryl group or heteroaryl group having 2 to 30 carbon atoms. The alkyl group may be further substituted with an aryl group or heteroaryl group having 2 to 20 carbon atoms, and the aryl group or heteroaryl group may be further substituted with a linear, cyclic or branched aryl 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 this specification and the like, an arylene group refers to an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon. Furthermore, in this specification and the like, a heteroarylene group refers to an atomic group obtained by removing two hydrogen atoms from an aromatic heterocycle. Regarding aromatic hydrocarbons and aromatic heterocycles, the same explanations as for aryl groups and heteroaryl groups apply.

(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, substituted or unsubstituted aromatic hydrocarbon structures, aromatic heterocyclic structures, and structures 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 this embodiment, the structural unit M is preferably a substituted or unsubstituted aromatic hydrocarbon structure from the viewpoint of imparting durability without reducing charge transportability, and is preferably a substituted or unsubstituted aromatic hydrocarbon structure. More preferably, it has a structure. Furthermore, as described below, when the charge transporting polymer has a polymerizable functional group at the terminal end, the structural unit M is a polymerizable structure (i.e., a polymerizable functional group such as a pyrrol-yl group). Good too. Specific examples of the structural unit M include the following.

In the above formula, R is a hydrogen atom or a substituent listed as R in structural unit D. When the charge transporting polymer has a polymerizable functional group at the terminal end, 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-valent structural unit that constitutes a branch when the charge transporting polymer has a branched structure. From the viewpoint of improving the durability of the organic electronics element, the structural unit T is preferably a structural unit with a valence of 6 or less, more preferably a structural unit with a valence of 4 or less, and even more preferably a structural unit with a valence of 3 or 4. It is. The structural unit T is preferably a unit having charge transport properties. For example, from the viewpoint of improving the durability of organic electronic devices, the structural unit T may include a substituted or unsubstituted triphenylamine structure, a carbazole structure, a fused polycyclic aromatic hydrocarbon structure, and one or two of these. Contains at least one type selected from structures containing at least one type. 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 arenetriyl group or a heteroarenetriyl group having 2 to 30 carbon atoms. In this specification and the like, the arenetriyl group refers to an atomic group obtained by removing three hydrogen atoms from an aromatic hydrocarbon. In this specification and the like, a heteroarenetriyl group refers to an atomic group obtained by removing three hydrogen atoms from an aromatic heterocycle. Ar each independently represents a divalent linking group, 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, and for example, from among the substituents listed as R in structural unit D (excluding groups containing a polymerizable functional group), Examples include divalent groups with one hydrogen atom removed. Z represents either a carbon atom, a silicon atom, or a phosphorus atom. In the structural unit, the condensed ring, W, Y, and Ar may have a substituent, and examples of the substituent include the substituents listed for R in the structural unit D.

(Polymerizable functional group)
In this embodiment, the charge transporting polymer preferably has at least one polymerizable functional group from the viewpoint of curing by polymerization reaction and changing the solubility in a solvent. "Polymerizable functional group" refers to a functional group that can form a bond with each other by applying at least one of heat and light.

Examples of polymerizable functional groups include groups having carbon-carbon multiple bonds (for example, vinyl group, allyl group, butenyl group, ethynyl group, acryloyl group, acryloyloxy group, acryloylamino group, methacryloyl group, methacryloyloxy group, methacryloylamino group) group, vinyloxy group, vinylamino group, etc.), groups with small member rings (for example, cyclic alkyl groups such as cyclopropyl group, cyclobutyl group; cyclic ether groups such as epoxy group (oxiranyl group), oxetane group (oxetanyl group) ; diketene group; episulfide group; lactone group; lactam group, etc.), heterocyclic groups (eg, furan-yl group, pyrrol-yl group, thiophen-yl group, 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, vinyl groups, acryloyl groups, methacryloyl groups, epoxy groups, and oxetane groups are particularly preferable, and from the viewpoint of reactivity and characteristics of organic electronic devices, vinyl groups, oxetane groups, and epoxy groups are more preferable. preferable.

From the viewpoint of increasing the degree of freedom of the polymerizable functional group and facilitating the polymerization reaction, it is preferable that the main skeleton of the charge transporting polymer and the polymerizable functional group are connected through an alkylene chain.
For example, when forming an organic layer on an electrode, from the viewpoint of improving affinity with a hydrophilic electrode such as ITO (indium oxide-tin oxide), a hydrophilic chain such as an ethylene glycol chain or a diethylene glycol chain may be used. Preferably, they are connected. Furthermore, from the viewpoint of facilitating the preparation of the monomer used to introduce the polymerizable functional group, the charge transporting polymer should be polymerizable with at least one of the terminal parts of the alkylene chain and the hydrophilic chain, that is, the end portion of the alkylene chain and the hydrophilic chain. The polymer may have an ether bond or an ester bond in at least one of the connecting portion with the sexual functional group and the connecting portion between these chains and the backbone of the charge transporting polymer. The above-mentioned "group containing a polymerizable functional group" means a polymerizable functional group itself or a group containing a polymerizable functional group and an alkylene chain. As the group containing a polymerizable functional group, for example, a group exemplified in International Publication No. 2010/140553 can be suitably used.

Whether the polymerizable functional group is introduced into the terminal end of the charge transporting polymer (i.e., structural unit M) or into a part other than the terminal end (i.e., structural unit D or T), It may be introduced both at the end and at a portion other than the end. From the viewpoint of curability, it is preferable that it is introduced at least at the end portion, and from the viewpoint of achieving both curability and charge transportability, it is preferable that it is introduced only to the end portion. In addition, 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, or may be introduced into both the main chain and the side chain. may have been introduced.

From the viewpoint of contributing to changes in solubility, it is preferable that a large amount of polymerizable functional groups be contained in the charge transporting polymer. On the other hand, the amount of the polymerizable functional group contained in the charge-transporting polymer is preferably small from the viewpoint of not interfering with charge-transporting properties. The content of the polymerizable functional group can be appropriately set in consideration of these factors.

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

The number of polymerizable functional groups per molecule of charge transporting polymer is determined by the amount of polymerizable functional groups used to synthesize the charge transporting polymer (for example, the amount of monomer having a polymerizable functional group), each structure It can be determined as an average value using the amount of monomer charged corresponding to the unit, the weight average molecular weight of the charge transporting polymer, etc. In addition, the number of polymerizable functional groups is determined by the ratio of the integral value of the signal derived from the polymerizable functional group in the ¹ H NMR (nuclear magnetic resonance) spectrum of the charge transporting polymer to the integral value of the entire spectrum, and the number of the charge transporting polymer. It can be calculated as an average value using the weight average molecular weight, etc. When the amount of preparation is clear, it is preferable to use the value determined using the amount of preparation because it is simple.

(number average molecular weight)
The number average molecular weight of the charge-transporting polymer can be adjusted as appropriate, taking into account solubility in solvents, film-forming properties, 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 transport properties. In addition, the number average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, and 50,000 or less, from the viewpoint of maintaining good solubility in the solvent and facilitating the preparation of the ink composition. The following are more preferable.

(Weight average molecular weight)
The weight average molecular weight of the charge-transporting polymer can be adjusted as appropriate, taking into account solubility in solvents, film-forming properties, and the like. The weight average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, and even more preferably 10,000 or more from the viewpoint of excellent charge transport properties. In addition, the weight average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, and 400,000 or less, from the viewpoint of maintaining good solubility in the solvent and facilitating the preparation of the ink composition. The following are more preferable.

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

(Percentage of structural units)
From the viewpoint of obtaining sufficient charge transport properties, the proportion 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 the total structural units. is even more preferable. Furthermore, considering the structural unit M and the structural unit T introduced as necessary, the proportion of the structural unit D is preferably 95 mol% or less, more preferably 90 mol% or less, and 85 mol% or less based on the total structural units. More preferably, it is less than mol%.

The proportion of the structural unit M contained in the charge transporting polymer is determined based on the total structural units, from the viewpoint of improving the characteristics of organic electronic devices, or from the viewpoint of suppressing the increase in viscosity and facilitating the synthesis of the charge transporting polymer. , is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more. Further, from the viewpoint of obtaining sufficient charge transport properties, the proportion of the structural unit M is preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less, based on the total structural units.

When the charge transporting polymer contains a structural unit T, the proportion of the structural unit T is preferably 1 mol% or more, more preferably 5 mol% or more, based on all structural units, from the viewpoint of improving the durability of the organic electronics device. Preferably, 10 mol% or more is more preferable. In addition, the proportion of the structural unit T is 50 mol% or less based on the total structural units, from the viewpoint of suppressing the increase in viscosity and favorably synthesizing the charge transporting polymer, or from the viewpoint of obtaining sufficient charge transportability. is preferable, 40 mol% or less is more preferable, and even more preferably 30 mol% or less.

When the charge transporting polymer has a polymerizable functional group, the proportion 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. The content is more preferably 1 mol% or more, and even more preferably 3 mol% or more. In addition, from the viewpoint of obtaining good charge transport properties, the proportion of the polymerizable functional group is preferably 70 mol% or less, more preferably 60 mol% or less, and even more preferably 50 mol% or less, based on all structural units. . Note that the "ratio of polymerizable functional groups" herein refers to the ratio of structural units having polymerizable functional groups.

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

The proportion of structural units can be determined using the amount of monomers corresponding to each structural unit used to synthesize the charge transporting polymer. Further, the proportion of structural units can be calculated as an average value using the integral value of the spectrum derived from each structural unit in the ¹ H NMR spectrum of the charge transporting polymer. When the amount of preparation is clear, it is preferable to use a value determined using the amount of preparation because it is simple.

(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, Stille coupling, and Buchwald-Hartwig coupling can be used. Suzuki coupling causes a cross-coupling reaction between an aromatic boronic acid derivative and an aromatic halide using a Pd catalyst. According to Suzuki coupling, a charge transporting polymer can be easily produced by bonding desired aromatic rings to each other.

In the coupling reaction, for example, a Pd(0) compound, a Pd(II) compound, a Ni compound, etc. are used as a catalyst. Further, it is also possible to use a catalyst species generated by using tris(dibenzylideneacetone)dipalladium(0), palladium(II) acetate, or the like as a precursor and mixing it with a phosphine ligand. Regarding the method for synthesizing the charge transporting polymer, the description in International Publication No. 2010/140553 can be cited, for example.

(Charge transporting low molecular compound)
The charge transporting low molecular weight compound will be explained below.
The charge transporting low molecular weight compound is not particularly limited as long as it contains an atomic group having the ability to transport 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 type of 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 structures of charge transporting low molecular weight compounds 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 electronic 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 of charge transporting compound.

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 formability. It is preferably 0.2% by mass or more, more preferably 0.5% by mass or more. Further, from the viewpoint of driving voltage of the organic electronic device, 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. More preferred.

[solvent]
The organic electronic material may further contain a solvent. Organic electronic materials containing solvents are preferably used in the production of organic electronic devices as ink compositions.

As the solvent, water, an organic solvent, or a mixed solvent thereof can be used. Examples of organic solvents 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, mesitylene, tetralin, and diphenylmethane; ethylene glycol Aliphatic ethers such as dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl, 2-methoxytoluene, 3-methoxytoluene, Aromatic ethers such as 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole; Aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, n-butyl lactate; phenyl acetate, propionic acid Aromatic esters such as phenyl, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate; Amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; dimethyl sulfoxide, tetrahydrofuran, acetone , chloroform, methylene chloride, etc. Preferred are aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers, and the like. As the solvent, a nonpolar organic solvent is preferred.

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 a solvent in an amount such that the ratio of charge transporting polymer to the solvent is 0.1% by mass or more, and preferably 0.2% by mass or more. It is more preferable that the solvent be contained in an amount of 0.5% by mass or more. Further, the ionic compound preferably contains an amount of solvent such that the ratio of the charge transporting polymer to the solvent is 20% by mass or less, more preferably 15% by mass or less. It is more preferable that the amount of the solvent is 10% by mass or less.

[Additive]
The organic electronic material may further contain additives as optional components. Examples of additives include polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, reduction inhibitors, oxidizing agents, reducing agents, surface modifiers, emulsifiers, antifoaming agents, Examples include dispersants and surfactants. Furthermore, if necessary, known polymerization initiators and dopants may be used together with the ionic compound within a range that does not impede the effects (e.g., heat resistance, device characteristics, etc.) of the ionic compound of this embodiment described above. .

<Organic layer>
The organic layer of this embodiment is 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, or a layer formed by polymerizing the formed layer. This is the layer that has been made insolubilized. By using an organic electronics material containing a solvent, an organic layer can be formed satisfactorily by a coating method. Application methods include, for example, spin coating methods; casting methods; dipping methods; plate printing methods such as letterpress printing, intaglio printing, offset printing, planographic printing, letterpress reversal offset printing, screen printing, and gravure printing; inkjet methods, etc. Known methods such as plateless printing can be used. When forming an organic layer by a 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 electronic material contains a charge transporting compound having a polymerizable functional group, the solubility of the organic layer can be changed by advancing the polymerization reaction by light irradiation, heat treatment, etc. In organic electronic materials, ionic compounds can function as polymerization initiators. By stacking organic layers with varying solubility, it becomes possible to easily create multilayer organic electronic devices. Regarding the method for forming the organic layer, for example, the description in International Publication No. 2010/140553 can be cited.
When the organic electronic material contains a charge-transporting compound having a polymerizable functional group, it is possible to improve the curability at low temperatures when used as an ink composition. Further, it becomes possible to stack organic layers in a good manner, and when an organic electronic device is manufactured, a long life of the organic electronic device can be achieved.

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

<Organic electronics device>
The organic electronic device according to this embodiment has at least the organic layer according to the embodiment described above. Examples of the organic electronics device include organic EL devices such as organic light emitting diodes (OLEDs), organic photoelectric conversion devices, and organic transistors. The organic electronic device preferably has a structure in which an organic layer is disposed between at least one pair of electrodes.

[Organic EL element]
The organic EL element according to this embodiment has at least one organic layer according to the above-described embodiment. An organic EL device usually includes a light emitting layer, an anode, a cathode, and a substrate, and if necessary, other functional layers such as a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, etc. We are prepared. Each layer may be formed by a vapor 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 still more preferably as at least one of a hole injection layer and a hole transport layer.

FIG. 1 is a schematic cross-sectional view showing one embodiment of an organic EL element. The organic EL device shown in FIG. 1 has a multilayer structure, and includes 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 multilayer structure in which 4 layers are laminated in this order. Note that FIG. 1 is an example, and the organic EL element of this embodiment is not limited to this diagram. In FIG. 1, the hole injection layer 3 is an organic layer formed using the above-mentioned organic electronics material, but the organic EL element of this embodiment is not limited to such a structure, and may have other organic layers. , or an organic layer formed using the above-mentioned organic electronics materials. For example, it is preferable to include an organic layer formed 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. Each layer will be explained below.

[Light-emitting layer]
As the material for the light-emitting layer, light-emitting materials such as low-molecular compounds, polymers, and dendrimers can be used. Polymers are preferred because they have high solubility in solvents and are suitable for coating methods. Examples of the luminescent material include fluorescent materials, phosphorescent materials, thermally activated delayed fluorescent materials (TADF), and the like.

As fluorescent materials, low-molecular compounds such as perylene, coumarin, rubrene, quinacridone, stilbene, dyes for dye lasers, aluminum complexes, and derivatives thereof; polyfluorene, polyphenylene, polyphenylene vinylene, polyvinylcarbazole, fluorene-benzothiadiazole copolymer , fluorene-triphenylamine copolymer, and derivatives thereof; and mixtures thereof.

As the phosphorescent material, metal complexes containing metals such as Ir and Pt can be used. Examples of Ir complexes include FIr(pic) (iridium(III) bis[(4,6-difluorophenyl)-pyridinate-N,C ² ]picolinate) which emits blue light, and Ir(ppy) ₃ which emits green light. (Fact Tris(2-phenylpyridine)iridium), which exhibits 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. Examples of the Pt complex include PtOEP (2, 3, 7, 8, 12, 13, 17, 18-octaethyl-21H, 23H-phorfin platinum), which emits red light.

When the light-emitting layer contains a phosphorescent material, it is preferable that it further contains a host material in addition to the phosphorescent material. As the host material, low molecular weight compounds, polymers, or dendrimers can be used. Examples of low-molecular compounds include CBP (4,4'-bis(9H-carbazol-9-yl)biphenyl), mCP (1,3-bis(9-carbazolyl)benzene), and CDBP (4,4'- Bis(carbazol-9-yl)-2,2'-dimethylbiphenyl), derivatives thereof, etc., and the polymers include the organic electronic materials of the above embodiments, polyvinylcarbazole, polyphenylene, polyfluorene, derivatives thereof, etc. 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 cited.

[Hole transport layer, hole injection layer]
The organic layer described above is preferably used as at least one of a hole injection layer and a hole transport layer, and more preferably at least as a hole transport layer. When the organic EL element 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 organic layer is used as a hole injection layer and a hole transport layer is further provided, 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, thiophene compounds, and the like.

[Electron transport layer, electron injection layer]
Examples of materials used for the electron transport layer and the electron injection layer include phenanthroline derivatives, bipyridine derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyrane dioxide derivatives, fused ring tetracarboxylic acid anhydrides such as naphthalene and perylene, and carbodiimides. , fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, thiadiazole derivatives, benzimidazole derivatives, quinoxaline derivatives, aluminum complexes (eg, BAlq, Alq ₃ ), and the like. The organic electronic materials of the embodiments described above can also be used.

[cathode]
As the cathode material, for example, metals or metal alloys such as Li, Ca, Mg, Al, In, Cs, Ba, Mg/Ag, LiF, and CsF are used.

[anode]
As the anode material, for example, metal (eg, Au) or other conductive material is used. Other materials include, for example, oxides (eg, ITO) and 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 flexible. Preferably used are quartz glass, a light-transmissive resin film, and the like.

Examples of the resin film include films containing polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, cellulose acetate propionate, etc. can be mentioned.

When using a resin film, the resin film may be coated with an inorganic material 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. Organic EL elements that emit white light (also referred to as white organic EL elements) are preferable because they can be used in various lighting fixtures such as home lighting, car interior lighting, watches, and backlights for liquid crystals.

As a method for forming a white organic EL element, a method can be used in which a plurality of light emitting materials are used to emit light of a plurality of colors at the same time to mix the colors. Combinations of multiple luminescent colors are not particularly limited, but include, for example, combinations containing three luminescent maximum wavelengths of blue, green, and red, and complementary color relationships such as blue and yellow, yellow-green, and orange, etc. An example is a combination containing two utilized emission maximum wavelengths. The color of the emitted light can be controlled by adjusting the type and amount of the light emitting material.

<Display element, lighting device, display device>
The display element according to this embodiment includes the organic EL element according to the embodiment described above. For example, a color display element can be obtained by using organic EL elements as elements corresponding to red, green, and blue (RGB) pixels. Image forming methods include a simple matrix type in which individual organic EL elements arranged in 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 according to this embodiment includes the organic EL element according to the above-described embodiment. Furthermore, the display device according to this embodiment includes a lighting device and a liquid crystal element as a display means. For example, the display device can be a display device that uses the illumination 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.

EXAMPLES The present invention will be explained in more detail with reference to examples below, but the present invention is not limited to the following examples.

<Synthesis of ionic compounds>

[Example 1]
(Synthesis of ionic compound 1)
Ionic Compound 1 having the following structure was synthesized as follows.
After adding 25 g of acetone and 5 g of pure water to 1.111 g (10 mmol) of diallylmethylamine and stirring to obtain a homogeneous solution, 3.653 g of a 10% aqueous hydrogen chloride solution was slowly added dropwise, and the mixture was stirred for 1 hour after completion of the dropwise 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 stirred for 1 hour. This was washed with water five times and dried to produce a white solid.

[Example 2]
(Synthesis of ionic compound 2)
Ionic compound 2 having the following structure was synthesized as follows.
After adding 25 g of acetone and 5 g of pure water to 1.132 g (10 mmol) of diethylallylamine and stirring to obtain a homogeneous solution, 3.653 g of a 10% aqueous hydrogen chloride solution was slowly added dropwise, and after the addition was completed, the mixture was stirred for 1 hour. 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 stirred for 1 hour. This was washed with water five times and dried to produce a white solid.

[Example 3]
(Synthesis of ionic compound 3)
Ionic compound 3 having the following structure was synthesized as follows.
After adding 25 g of acetone and 5 g of pure water to 1.372 g (10 mmol) of triallylamine and stirring to obtain a homogeneous solution, 3.653 g of a 10% aqueous hydrogen chloride solution was slowly added dropwise, and after the addition was completed, the mixture was stirred for 1 hour. 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 stirred for 1 hour. This was washed with water five times and dried to produce a white solid.

[Comparative example 1]
(Synthesis of ionic compound 4)
Ionic compound 4 having the following structure was synthesized as follows.
After adding 25 g of acetone and 5 g of pure water to 2.986 g (10 mmol) of N,N-dimethyloctadecylamine and stirring to obtain a homogeneous solution, 3.653 g of a 10% aqueous hydrogen chloride solution was slowly added dropwise, and after the completion of the dropwise addition, the mixture was stirred for 1 hour. 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 stirred for 1 hour. This was washed with water five times and dried to produce a white solid.

[Comparative example 2]
(Synthesis of ionic compound 5)
Ionic Compound 5 having the following structure was synthesized as follows.
After adding 25 g of acetone and 5 g of pure water to 3.126 g (10 mmol) of N,N-didecanomethylamine and stirring to obtain a homogeneous solution, 3.653 g of a 10% aqueous hydrogen chloride solution was slowly added dropwise, and 1 hour after the completion of the dropwise 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 stirred for 1 hour. This was washed with water five times and dried to produce a white solid.

[Comparative example 3]
(Synthesis of ionic compound 6)
Ionic compound 6 having the following structure was synthesized as follows.
After adding 25 g of acetone and 5 g of pure water to 5.220 g (10 mmol) of tridodecanoamine and stirring to obtain a homogeneous solution, 3.653 g of a 10% aqueous hydrogen chloride solution was slowly added dropwise, and after the completion of the dropwise addition, the mixture was stirred for 1 hour. 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 stirred for 1 hour. This was washed with water five times and dried to produce a white solid.

[Comparative example 4]
(Synthesis of ionic compound 7)
Ionic Compound 7 having the following structure was synthesized as follows.
After adding 25 g of acetone and 5 g of pure water to 2.274 g (10 mmol) of tripentylamine and stirring to obtain a homogeneous solution, 3.653 g of a 10% aqueous hydrogen chloride solution was slowly added dropwise, and after the completion of the dropwise addition, the mixture was stirred for 1 hour. 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 stirred for 1 hour. This was washed with water five times and dried to produce a white solid.

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

Ionic Compounds 1 to 3 (Examples 1 to 3), which are the embodiments described above, all showed high weight loss temperatures when compared to Ionic Compounds 4 to 7 (Comparative Examples 1 to 4). It can be seen that by using an ionic compound with a small thermal weight loss, excellent heat resistance can be achieved.

EXAMPLES The present invention will be explained in more detail with reference to examples below, but the present invention is not limited to the following examples.

<Preparation of charge transporting polymer>
[Preparation of Pd catalyst]
In a glove box under a nitrogen atmosphere, tris(dibenzylideneacetone)dipalladium (73.2 mg, 80 μmol) was weighed into a sample tube at room temperature, 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 Pd catalysts, all solvents were used after being degassed with nitrogen bubbles for at least 30 min.

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

(Preparation of charge transporting polymer 1)
In a three-neck round bottom flask, 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) "Aliquot 336") (0.04 g), 3M potassium hydroxide aqueous solution (7.79 g), and toluene (53 mL) were added, and the previously prepared Pd catalyst solution (1.0 mL) was 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. Additionally, all solvents were used after being degassed with nitrogen bubbles for at least 30 minutes.

After the reaction was completed, the organic layer was washed with water and poured into methanol-water (9:1). The resulting precipitate was collected by suction filtration and washed with methanol-water (9:1). The obtained 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, polymer-bound on styrene-divinylbenzene copolymer" manufactured by Strem Chemicals, 200 mg per 100 mg of precipitate) was added to the solution. Stirred at ℃ for 2 hours. After the stirring was completed, the metal adsorbent and insoluble matter were removed by filtration, and then poured into methanol to cause reprecipitation. The resulting precipitate was collected by suction filtration and washed with methanol. The obtained precipitate was vacuum dried to produce charge transporting polymer 1. 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 weight average molecular weight were measured by GPC (polystyrene equivalent) using tetrahydrofuran (THF) as an eluent. The measurement conditions are as follows.
Equipment: High performance liquid chromatograph Prominence Shimadzu Corporation
Liquid pump (LC-20AD)
Deaeration unit (DGU-20A)
Auto sampler (SIL-20AHT)
Column oven (CTO-20A)
PDA detector (SPD-M20A)
Differential refractive index detector (RID-20A)
Column: Gelpack (registered trademark)
GL-A160S (serial number: 686-1J27)
GL-A150S (manufacturing number: 685-1J27) Hitachi Chemical Co., Ltd. Eluent: Tetrahydrofuran (THF) (for HPLC, contains stabilizer) Fujifilm Wako Pure Chemical Industries, Ltd. Flow rate: 1 mL/min
Column temperature: 40℃
Detection wavelength: 254nm
Molecular weight standard material: PStQuick A/B/C Tosoh Corporation

[Solvent resistance evaluation]
Organic layers A1 to A7 were formed using charge transporting polymer 1 and ionic compounds 1 to 7, and solvent resistance was evaluated by measuring the residual film rate.

(residual film rate measurement)
The ionic compound (10 mg) used in Example 1 was weighed into a 20 mL screw tube, and a certain amount of chlorobenzene was added and stirred to prepare an ionic compound solution. Next, charge transport polymer 1 (10 mg) and a certain amount of chlorobenzene (792 μL) were added to a 9 mL screw tube to dissolve the charge transport polymer. Thereafter, a certain amount of the ionic compound solution was added to the aforementioned 9 mL screw tube and stirred to prepare an ink composition. After filtering the ink composition through a polytetrafluoroethylene (PTFE) filter (pore size: 0.2 μm), it was dropped onto a quartz substrate (length: 22 mm x width: 29 mm x thickness: 0.7 mm), and a coating film was formed using a spin coater. It was filmed. Subsequently, heat curing was performed at 200° C. for 30 minutes in a nitrogen atmosphere to form an organic layer with a thickness of 30 nm on the quartz substrate. (The solution was adjusted so that the charge transport polymer was 1 wt% and the ionic compound was 1 wt% relative to the charge transport 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 sample was immersed in anisole (10 mL, 25°C) for 10 minutes in a 25°C environment so that the organic layer after measurement was on the top. The absorbance B of the organic layer after immersion in anisole was measured, and the residual film rate 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. Note that the value at the maximum absorption wavelength of the organic layer was used as the absorbance value. The higher the residual film ratio, the better the solvent resistance.

[Number 1]
Remaining film rate (%) = (Absorbance B/Absorbance A) x 100

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

The organic layers A1 to A3 using ionic compounds 1 to 3 according to the present embodiment have a better residual film rate and are better in film formability than the organic layers A4 to A7 using ionic compounds 4 to 7. Good measurement results were shown.

EXAMPLES The present invention will be explained in more detail with reference to examples below, but the present invention is not limited to the following examples.

[Element characteristics evaluation]
Organic EL devices 1 to 7 were prepared using charge transporting polymer 1 and ionic compounds 1 to 7 according to the following procedure, and the driving voltage, luminous efficiency, and luminescent lifetime were evaluated.

(Production of organic EL element)
The ionic compound (10.0 mg) used in Example 1 was weighed into a 20 mL screw tube, and a certain amount of chlorobenzene was added and stirred to prepare an ionic compound solution. Next, a charge transporting polymer (10 mg) and a certain amount of chlorobenzene were added to a 9 mL screw tube to dissolve the charge transporting polymer. Thereafter, a certain amount of the ionic compound solution was added to the aforementioned 9 mL screw tube and stirred to prepare an ink composition. ITO patterned to a width of 1.6 mm was formed on a glass substrate (22 mm long x 29 mm wide x 0.7 mm thick), and the ink composition was applied to the glass substrate and the formed ITO using a polytetrafluoroethylene (PTFE) filter ( A filtrate prepared by filtration through a pore size of 0.2 μm was added dropwise, and a coating film was formed using a spin coater. Next, 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 transport polymer was 1 wt% and the ionic compound was 1 wt% relative to the charge transport polymer.)

The glass substrate having the hole injection layer was transferred into a vacuum evaporator, and α-NPD (40 nm), CBP:Ir(ppy) ₃ (94:6, 30 nm), BAlq (10 nm), and TPBi were deposited on the hole injection layer. (30 nm), LiF (0.8 nm), and Al (100 nm) were deposited in this order by vapor deposition. Thereafter, a sealing treatment 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 organic EL element, the driving voltage, luminous efficiency, and luminous lifetime (luminance half-life time) at an initial luminance of 5,000 cd/m ² were measured at a luminance of 5,000 cd/m ² .

Table 3 shows the measurement results of driving voltage, luminous efficiency, and luminous lifetime.

Organic EL devices 1 to 3 using ionic compounds 1 to 3 according to the present embodiment are superior in driving voltage, luminous efficiency, and luminous lifetime compared to organic EL devices 4 to 7 using ionic compounds 4 to 7. It showed good measurement results.

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 (11)

An ionic compound containing an ammonium cation represented by the following formula (1a) and an anion represented by any of the following formulas (1b) to (5b).

(In formula (1a), R ^a , R ^b and R ^c each independently represent an alkyl group having 4 or less carbon atoms or an alkenyl group having 4 or less carbon atoms , and R ^a , R ^b and R ^c At least one selected from is an alkenyl group having 4 or less carbon atoms .)

(In formulas (1b) to (5b),
E ¹ is an oxygen atom, E ² is a nitrogen atom, E ³ is a carbon atom, E ⁴ is a boron atom or a gallium atom, E ⁵ is a phosphorus atom or an antimony atom,
Y ¹ to Y ⁶ each independently represent a single bond or a divalent linking group,
R ¹ to R ¹⁶ each independently represent an electron-withdrawing monovalent group (R ² and R ³ , at least two groups selected from R ⁴ to R ⁶ , at least two groups selected from R ⁷ to R ¹⁰ ); The two groups and at least two groups selected from R ¹¹ to R ¹⁶ may each be bonded to each other. ) The electron-withdrawing monovalent group in the formulas (1b) to (5b) is a linear or branched perfluoroalkyl group having 1 to 8 carbon atoms, or a cyclic perfluoroalkyl group having 3 to 6 carbon atoms. The ionic compound according to claim 1, which is an alkyl group or a perfluoroaryl group having 6 to 18 carbon atoms. Claim 1 or 2, wherein Y ¹ to Y ⁶ in formulas (1b) to (5b) are each independently a single bond or a linking group represented by any one of the following formulas (1c) to (11c): The ionic compounds described.
The ionic compound according to any one of claims 1 to 3 , wherein in the ammonium cation represented by the formula (1a) , the double bond of the alkenyl group is located at the terminal of the alkenyl group . The ionic compound according to any one of claims 1 to 3 , wherein in the ammonium cation represented by formula (1a), R ^a , R ^b and R ^c are one propenyl group and two ethyl groups. In the ammonium cation represented by the formula (1a), R ^a , R ^b and R ^c are two propenyl groups and one methyl group, or R ^b and R ^c are three propenyl groups. The ionic compound according to any one of 1 to 3. An organic electronics material comprising the ionic compound according to any one of claims 1 to 6 and a charge transporting compound. The organic electronics according to claim 7 , 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 7 or 8 , wherein the charge transporting compound has one or more polymerizable functional groups in its molecule. The organic electronic material according to claim 9 , wherein the polymerizable functional group includes 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 7 to 10 , further comprising a solvent.

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