JP7552203B2 - Organic Electronic Materials and Their Applications - Google Patents

Description

One embodiment of the present disclosure relates to an organic electronic material. Another embodiment of the present disclosure relates to the use of the organic electronic material. More specifically, the present disclosure relates to an organic layer, an organic electronic element, an organic electroluminescence element, a display element, a lighting device, and a display device formed using the organic electronic material.

Organic electronics elements are elements that use organic materials to perform electrical functions, and are expected to offer advantages such as energy saving, low cost, and flexibility, and are attracting attention as a technology that can replace conventional silicon-based inorganic semiconductors. Examples of organic electronics elements include organic electroluminescence elements (hereinafter also referred to as "organic EL elements"), organic photoelectric conversion elements, and organic transistors.

Among organic electronic elements, organic EL elements have been attracting attention as a large-area solid-state light source that can replace incandescent lamps and gas-filled lamps. They are also attracting attention as a promising self-luminous display that can replace liquid crystal displays (LCDs) in the field of flat panel displays (FPDs), and commercialization of these elements is progressing.

The manufacturing methods for organic EL elements can be broadly divided into two types: dry processes, in which films are formed mainly in a vacuum system, and wet processes, in which films are formed by plate printing such as letterpress printing and intaglio printing, or plateless printing such as inkjet printing. Progress is being made in the development of materials suitable for each process.

Because wet processes allow for easy film formation, they are expected to be an essential method for the future enlargement of organic EL displays. For this reason, efforts have been made to develop organic electronics materials that can be used in wet processes. For example, charge-transporting polymers with polymerizable functional groups have been reported (for example, Patent Document 1).

International Publication No. 2010/140553

Organic EL elements produced by a wet process have the advantage of being easy to produce at low cost and with a large area. However, organic EL elements produced by a wet process are still not fully satisfactory in various properties such as driving voltage, luminous life, and luminous efficiency, and improvements are required. In particular, from the viewpoint of lowering the driving voltage and extending the life of organic EL elements, there is a demand for organic electronic materials with excellent conductivity. Therefore, in view of the above, one embodiment of the present disclosure provides an organic electronic material with excellent conductivity.

As a result of extensive research, the inventors discovered that charge-transporting polymers having silyl groups have excellent electrical conductivity, leading to the completion of the present invention.

That is, one embodiment of the present invention relates to an organic electronic material containing a charge transporting polymer having a silyl group represented by the following formula (I).
_-SiR3 (I)
[In the formula, each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom.]

In the organic electronics material, the charge transport polymer preferably has a silyl group represented by formula (I) at its terminal.

In the organic electronic material, the charge transporting polymer preferably contains a terminal structure having a silyl group represented by the following formula (IA).
-Ar-(SiR ₃ )n (IA)
[In the formula, Ar is an arylene group, each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom, and n is an integer from 1 to 20.]

［式中、Ｒは、それぞれ独立して、水素原子、アルキル基、アリール基、ヘテロアリール基、又はハロゲン原子であり、ｎは１～５の整数である。］ In the organic electronic material, the charge transporting polymer preferably contains a terminal structure having a silyl group represented by the following formula (IA-1).

[In the formula, each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom, and n is an integer of 1 to 5.]

In the organic electronics material, it is preferable that the charge transport polymer further has a polymerizable functional group.

In the organic electronic material, the charge transport polymer preferably contains one or more structures selected from the group consisting of substituted or unsubstituted aromatic amine structures, carbazole structures, thiophene structures, bithiophene structures, benzothiophene structures, pyridine structures, furan structures, quinoline structures, benzene structures, and fluorene structures.

In the organic electronics material, it is preferable that the charge transport polymer has a structure that branches in three or more directions.

One embodiment relates to an ink composition comprising the organic electronic material of the above embodiment and a solvent.

One embodiment relates to an organic layer formed using the organic electronics material or ink composition of the above embodiment.

One embodiment relates to an organic electronics element having the organic layer of the above embodiment.

One embodiment relates to an organic electroluminescence element having the organic layer of the above embodiment.

One embodiment relates to a display device equipped with the organic electroluminescence element of the above embodiment.

One embodiment relates to a lighting device equipped with the organic electroluminescence element of the above embodiment.

One embodiment relates to a display device that includes the lighting device of the above embodiment and a liquid crystal element as a display means.

According to one embodiment of the present disclosure, an organic electronic material having excellent electrical conductivity can be provided. In addition, the organic electronic material can be used to form an organic layer having excellent electrical conductivity, thereby making it possible to achieve a low driving voltage and a long life for organic electronic elements such as organic EL elements.

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

The following describes an embodiment of the present invention, but the present invention is not limited to the following embodiment and includes various embodiments.

<Organic Electronics Materials>
The organic electronic material contains a charge transporting polymer having a silyl group represented by the following formula (I).
_-SiR3 (I)

In the above formula, each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom.
The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and even more preferably 1 to 12 carbon atoms. The alkyl group may have any of a linear structure, a branched structure, and a cyclic structure. In one embodiment, an alkyl group having a linear or branched structure and having 1 to 12 carbon atoms is preferred. From the viewpoint of solubility, the alkyl group more preferably has 2 to 10 carbon atoms, and even more preferably has 3 to 8 carbon atoms. The aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon, and preferably has 6 to 30 carbon atoms. In one embodiment, a phenyl group or a naphthylene group is preferred.
The heteroaryl group is an atomic group obtained by removing one hydrogen atom from an aromatic heterocycle, and preferably has a carbon number of 2 to 30. In one embodiment, a triphenylamine group or a carbazole group is preferred.
The alkyl group may be further substituted with an aryl group or a heteroaryl group, and the aryl group or the heteroaryl group may be further substituted with a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms.
The halogen atom may be a fluorine atom, a bromine atom, or a chlorine atom. In one embodiment, a fluorine atom is preferred.

In one embodiment, each R in the above formula (I) is preferably independently a hydrogen atom, an alkyl group, or an aryl group. It is more preferable that at least one of the three Rs bonded to the Si atom is an alkyl group or an aryl group. In one embodiment, it is more preferable that at least two Rs are alkyl groups or aryl groups, and it is even more preferable that all three Rs are alkyl groups and/or aryl groups, which is a tri-substituted silyl group. In one embodiment, the structural portion represented by the above formula (I) is preferably a trialkylsilyl group, an alkylarylsilyl group, or a triarylsilyl group.

The above trialkylsilyl group has a structure in which the three Rs bonded to the Si atom are replaced with alkyl groups. Specific examples include trimethylsilyl, triethylsilyl, tripropylsilyl, triisopropylsilyl, tri-n-butylsilyl, tri-s-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, diethylmethylsilyl, n-propyldimethylsilyl, di-n-propylmethylsilyl, ethyldi-n-propylsilyl, diethyl-n-propylsilyl, n-butyldimethylsilyl, di-n-butylmethylsilyl, n-butylethyldisilyl, n-butyldiethylsilyl, n-butyldi-n-propylsilyl, di-n-butyl-n-propylsilyl, and n-butyldiisopropylsilyl. silyl, di-n-butylisopropylsilyl, s-butyldimethylsilyl, di-s-butylmethylsilyl, s-butylethyldisilyl, s-butyldiethylsilyl, s-butyldi-n-propylsilyl, di-s-butyln-propylsilyl, s-butyldiisopropylsilyl, di-s-butylisopropylsilyl, t-butyldimethylsilyl, di-t-butylmethylsilyl, t-butyldiethylsilyl, di-t-butylethylsilyl, t-butyldi-n-propylsilyl, di-t-butyln-propylsilyl, t-butyldiisopropylsilyl, and di-t-butylisopropylsilyl.

The alkylarylsilyl group has a structure in which the three Rs bonded to the Si atom are substituted with alkyl and aryl groups. Specific examples include dimethylphenylsilyl, methyldiphenylsilyl, diethylphenylsilyl, ethyldiphenylsilyl, di-n-propylphenylsilyl, n-propyldiphenylsilyl, diisopropylphenylsilyl, isopropyldiphenylsilyl, di-n-butylphenylsilyl, n-butyldiphenylsilyl, di-s-butylphenylsilyl, s-butyldiphenylsilyl, di-t-butylphenylsilyl, and t-butyldiphenylsilyl.

The above triarylsilyl group refers to a structure in which the three Rs bonded to the Si atom are replaced with aryl groups. Specific examples include a triphenylsilyl group and a trinaphthylsilyl group.

The aryl group in the alkylarylsilyl group or the triarylsilyl group may be further substituted with a substituent such as an alkyl group. The aryl group may have a structure such as tolyl-substituted (o-, m-, p-methylphenyl), xylyl-substituted (dimethylphenyl), or mesityl-substituted (trimethylphenyl).

In one embodiment, the silyl group is preferably a tri-substituted silyl group selected from the group consisting of trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, tri-t-butylsilyl, dimethylphenylsilyl, methyldiphenylsilyl, di-t-butylphenylsilyl, t-butyldiphenylsilyl, and triphenylsilyl.

The organic electronics material may contain two or more types of charge transport polymers having a silyl group represented by formula (I) above, or may further contain other charge transport polymers. Charge transport polymers are described in more detail below.

[Charge transport polymer]
The charge transporting polymer constituting the organic electronic material may have a structural portion having a silyl group represented by the above formula (I) and may have the ability to transport charges. In one embodiment, the charge to be transported is preferably a hole. A hole transporting compound can be used, for example, as a hole injection layer or a hole transport layer of an organic EL element. Also, an electron transporting compound can be used as an electron transport layer or an electron injection layer. Also, a compound that transports both holes and electrons can be used as a material for a light emitting layer. In one embodiment, the charge transporting polymer can be suitably used as a material for at least one of a hole injection layer and a hole transport layer.

The charge transporting polymer has one or more structural units having charge transportability, and at least one of the structural units has a silyl group represented by the above formula (I). The charge transporting polymer may be linear or have a branched structure. The charge transporting polymer preferably contains at least a divalent structural unit L having charge transportability and a monovalent structural unit T constituting the terminal portion, and may further contain a trivalent or higher structural unit B constituting the branch portion.

In one embodiment, the charge transporting polymer preferably contains a divalent structural unit L having charge transport properties and a trivalent or higher structural unit B having charge transport properties. The charge transporting polymer may contain only one type of each structural unit, or may contain multiple types of each structural unit. In the charge transporting polymer, the structural units are bonded to each other at "monovalent" to "trivalent or higher" bonding sites.

Examples of partial structures contained in the charge transporting polymer include the following. The charge transporting polymer is not limited to polymers having the following partial structures. In the partial structures, "L" represents structural unit L, "T" represents structural unit T, and "B" represents structural unit B. "*" represents a bonding site with other structural units. In the partial structures below, multiple Ls may be the same structural unit or different structural units. The same applies to T and B.

Examples of linear charge-transporting polymers

Examples of charge-transporting polymers with branched structures

The silyl group represented by the above formula (I) may be introduced into the terminal portion of the charge transport polymer (i.e., the structural unit T), into a portion other than the terminal portion (i.e., the structural unit L or B), or into both the terminal portion and the portion other than the terminal portion. From the viewpoint of the solubility of the polymer, it is preferable that it is introduced into the terminal portion. In addition, when the charge transport polymer has a branched structure, the silyl group represented by the above formula (I) may be introduced into the main chain of the charge transport polymer, into the side chain, or into both the main chain and the side chain.

From this viewpoint, the charge transporting polymer preferably contains a structural moiety having a silyl group represented by the following formula (IA).
-Ar-(SiR ₃ )n (IA)
In the formula, Ar is an arylene or heteroarylene group. Each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom, as described above in detail. n is an integer of 1 or more that varies depending on the structure of Ar. In one embodiment, n is preferably an integer of 1 to 20, more preferably an integer of 1 to 10, and even more preferably an integer of 1 to 5. Each structural unit will be described in more detail below.

(Structural unit L)
The structural unit L is a divalent structural unit having charge transportability. The structural unit L is not particularly limited as long as it contains an atomic group having the ability to transport charge. For example, the structural unit L is selected from substituted or unsubstituted aromatic amine structures, carbazole structures, thiophene structures, fluorene structures, benzene structures, biphenyl structures, terphenyl structures, naphthalene structures, anthracene structures, tetracene structures, phenanthrene structures, dihydrophenanthrene structures, pyridine structures, pyrazine structures, quinoline structures, isoquinoline structures, quinoxaline structures, acridine structures, diazaphenanthrene structures, furan structures, pyrrole structures, oxazole structures, oxadiazole structures, thiazole structures, thiadiazole structures, triazole structures, benzothiophene structures, benzoxazole structures, benzoxadiazole structures, benzothiazole structures, benzothiadiazole structures, benzotriazole structures, phenoxazine structures, and structures containing one or more of these. The aromatic amine structure may be an aniline structure, but is preferably a triarylamine structure, and more preferably a triphenylamine structure.

In one embodiment, from the viewpoint of obtaining excellent hole transport properties, the structural unit L preferably includes one or more structures selected from the group consisting of a substituted or unsubstituted aromatic amine structure, a carbazole structure, a thiophene structure, a bithiophene structure, a benzothiophene structure, a pyridine structure, a furan structure, a quinoline structure, a benzene structure, and a fluorene structure.
In one embodiment, the benzene structure may be a part of an aromatic amine structure, such as a triphenylamine structure, or may form a benzoporphyrin structure in combination with a pyrrole structure. More preferably, the structural unit L is selected from a substituted or unsubstituted aromatic amine structure, a carbazole structure, and a structure containing one or more of these.

Specific examples of structural unit L include the following. Structural unit L is not limited to the following.

Each R independently represents a hydrogen atom or a substituent. When R is a substituent, the substituent is preferably selected from the group consisting of -R ¹ , -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ , a halogen atom, and a polymerizable functional group described below. In one embodiment, from the viewpoint of introducing a silyl group represented by formula (IA) or a structural moiety represented by (IA), R may be -SiR ⁶ R ⁷ R ⁸ .
R ¹ to R ⁸ each independently represent a hydrogen atom (except for R ¹ ); a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms; or an aryl or heteroaryl group having 2 to 30 carbon atoms. An aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. A heteroaryl group is an atomic group obtained by removing one hydrogen atom from an aromatic heterocycle.
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 alkyl group having 1 to 22 carbon atoms.

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. An arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon. A heteroarylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic heterocycle. Ar is preferably an arylene group, and more preferably a phenylene group.
The aromatic hydrocarbon may be a monocyclic ring, a condensed ring, or a polycyclic ring in which two or more rings selected from a monocyclic ring and a condensed ring are bonded via a single bond. The aromatic heterocyclic ring may be a monocyclic ring, a condensed ring, or a polycyclic ring in which two or more rings selected from a monocyclic ring and a condensed ring are bonded via a single bond.

In one embodiment, the structural unit L preferably includes at least one of an aromatic amine structure and a carbazole structure. The aromatic amine structure is preferably a triphenylamine structure. In the triphenylamine structure, at least one phenyl group may have a substituent. In one embodiment, the substituent is preferably an electron-withdrawing group such as a fluorine atom or a fluoroalkyl group. The carbon number of the fluoroalkyl group is preferably 1 to 4, more preferably 1 or 2. The fluoroalkyl group may be a perfluoroalkyl group. In one embodiment, the structural unit L preferably has the following structure. In the formula, the substituent Ra is a fluorine atom or a fluoroalkyl group, and the details are as described above. Although not particularly limited, when the triphenylamine structure has the above structure, it is preferable because it tends to be easy to obtain excellent conductivity.

(Structural unit B)
The structural unit B is a trivalent or higher structural unit constituting a branched portion when the charge transporting polymer has a branched structure. From the viewpoint of improving the durability of an organic electronics element, the structural unit B is preferably hexavalent or lower, more preferably trivalent or tetravalent. The structural unit B is preferably a unit having charge transport properties. For example, from the viewpoint of improving the durability of an organic electronics element, the structural unit B is preferably a substituted or unsubstituted aromatic amine structure, a carbazole structure, or a condensed polycyclic aromatic hydrocarbon structure.

Specific examples of the structural unit B include the following: The structural unit B 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. The arenetriyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic hydrocarbon. The heteroarenetriyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic heterocycle. Ar each independently represents a divalent linking group, for example, 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 examples thereof include divalent groups in which one hydrogen atom has been removed from a group having one or more hydrogen atoms among R in the structural unit L (excluding the structural portion represented by formula (IA) above and polymerizable functional groups).
Z represents any one of a carbon atom, a silicon atom, or a phosphorus atom. In the structural unit, the benzene ring and Ar may have a substituent. An example of the substituent is R in the structural unit L. In one embodiment, the structural unit B may have a structural moiety represented by the above formula (I) as a substituent.
In one embodiment, the structural unit B preferably contains at least one of an aromatic amine structure and a carbazole structure.

(Structural unit T)
The structural unit T is a monovalent structural unit constituting the terminal portion of the charge transporting polymer. The structural unit T 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 T may have the same structure as the structural unit L. In one embodiment, the structural unit T is preferably a substituted or unsubstituted aromatic hydrocarbon structure, more preferably a substituted or unsubstituted benzene structure, from the viewpoint of imparting durability without reducing the charge transportability.

In one embodiment, the charge transporting polymer preferably contains, as the structural unit T, a terminal structure T1 having a silyl group represented by the following formula:
-Ar-(SiR ₃ )n (IA)
In the formula, Ar is an arylene group, each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom, and n is an integer of 1 to 20. The details are as described above.

式中、Ｒは、それぞれ独立して、水素原子、アルキル基、アリール基、ヘテロアリール基、又はハロゲン原子である。詳細は先に説明した通りである。ｎは１～５の整数であり、１又は２が好ましい。＊は他の構造単位との結合部位を表す。 In one embodiment, the charge transporting polymer more preferably contains, as the structural unit T, a terminal structure (structural unit T1) having a silyl group represented by the following formula (IA-1).

In the formula, each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom. Details are as described above. n is an integer of 1 to 5, and preferably 1 or 2. * represents a bonding site with other structural units.

特に限定するものではないが、一実施形態において、構造単位Ｔ１としては、式（ａ）又は（ｃ）で表される構造が好ましい。 Specific examples of the structural unit T1 having a silyl group include the following.

Although not particularly limited, in one embodiment, the structural unit T1 is preferably a structure represented by formula (a) or (c).

In one embodiment, from the viewpoint of increasing the conductivity of the charge transport polymer, the proportion of structural units T1 having a silyl group is preferably 50 mol % or more, more preferably 75 mol % or more, and even more preferably 85 mol % or more, based on the total amount of structural units T. In one embodiment, the proportion of the structural units T2 can be 100 mol %.

In one embodiment, the charge transporting polymer preferably has a polymerizable functional group at the end from the viewpoint of enhancing curability. Therefore, the charge transporting polymer preferably has a structural unit T2 at the end, which is represented by the following formula (II). In the formula, Ar, X, and Y are as described above.
-Ar-X-Y (II)

In the above formula (II), Ar represents an arylene group or heteroarylene group having 2 to 30 carbon atoms. The arylene group means a group having a structure obtained by removing two hydrogen atoms from an aromatic hydrocarbon. The heteroarylene group means a group having a structure obtained by removing two hydrogen atoms from an aromatic heterocycle. The aromatic hydrocarbon and aromatic heterocycle may each be a monocyclic structure such as benzene, or a fused ring structure in which rings are fused to each other, such as naphthalene.
Specific examples of aromatic hydrocarbons include benzene, naphthalene, anthracene, tetracene, fluorene, and phenanthrene.Specific examples of aromatic heterocycles include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, and benzothiophene.
The aromatic hydrocarbon and aromatic heterocycle may be a polycyclic structure in which two or more rings selected from a monocycle and a condensed ring are bonded via a single bond. Examples of aromatic hydrocarbons having such a polycyclic structure include biphenyl, terphenyl, and triphenylbenzene. The aromatic hydrocarbon and aromatic heterocycle may be unsubstituted or may have one or more substituents. The substituent may be, for example, a linear, cyclic, or branched alkyl group having 1 to 22 carbon atoms. The number of carbon atoms is preferably 1 to 15, more preferably 1 to 12, and even more preferably 1 to 6. In one embodiment, Ar is preferably a phenylene group or a naphthylene group, and more preferably a phenylene group.

In the above formula (II), X is a divalent group (linking group) derived from an aliphatic hydrocarbon group having 1 to 10 carbon atoms. The linking group may have a linear, branched, cyclic, or combination thereof. The linking group may be saturated or unsaturated. In one embodiment, from the viewpoint of easy availability of monomers, the linking group preferably has a linear structure. It is more preferable that the linking group has a saturated linear structure.

From the above viewpoint, in the above formula (II), X is preferably -(CH ₂ )n-, where n is preferably an integer of 1 to 10, more preferably an integer of 1 to 8, and even more preferably an integer of 1 to 7. In one embodiment, from the viewpoint of solubility, n is more preferably an integer of 2 to 10, and even more preferably an integer of 3 to 8.

In the above formula (II), Y represents a polymerizable functional group. A "polymerizable functional group" refers to a functional group that can form a bond by applying at least one of heat and light. The polymerizable functional group Y may be unsubstituted or may have a substituent.

Specific examples of the polymerizable functional group Y include groups having a carbon-carbon multiple bond (e.g., vinyl group, allyl group, butenyl group, ethynyl group, acryloyl group, methacryloyl group), groups having a small ring (e.g., cyclic alkyl groups such as cyclopropyl group and cyclobutyl group; cyclic ether groups such as epoxy group (oxiranyl group) and oxetane group (oxetanyl group); diketene group; episulfide group; lactone group; lactam group, etc.), and heterocyclic groups (e.g., furanyl group, pyrrolyl group, thiophenyl group, siloleyl group).

In one embodiment, the polymerizable functional group Y may be any one of a substituted or unsubstituted oxetane group, an epoxy group, a vinyl group, an acryloyl group, and a methacryloyl group. From the viewpoint of reactivity and the properties of the organic electronics element, a substituted or unsubstituted vinyl group, an oxetane group, or an epoxy group is more preferable. When these polymerizable functional groups have a substituent, the substituent is preferably a linear, cyclic, or branched saturated alkyl group having 1 to 22 carbon atoms. The number of carbon atoms is more preferably 1 to 8, and even more preferably 1 to 4. The substituent is most preferably a linear saturated alkyl group having 1 to 4 carbon atoms.

In one embodiment, from the viewpoint of storage stability, the polymerizable functional group Y is preferably a substituted or unsubstituted oxetane group represented by the following formula (Y1): In the formula, R may be a hydrogen atom or a saturated alkyl group having 1 to 4 carbon atoms. It is particularly preferable that R is a methyl group or an ethyl group.

A charge transport polymer having at least one structural portion represented by the above formula (II) contains at least one polymerizable functional group Y in its structure. Compounds containing polymerizable functional groups can be cured by a polymerization reaction, and the solubility in a solvent can be changed by curing. Therefore, a charge transport polymer having at least one structural portion represented by the above formula (II) has excellent curability and is a material suitable for wet processes.

By using a charge transport polymer containing the structural unit T2, it becomes easy to obtain excellent curability. It is more preferable that the charge transport polymer has a structural moiety represented by the above formula (II) as the structural unit T2. In one embodiment, from the viewpoint of enhancing the curability of the charge transport polymer, the proportion of the structural unit T2 having the structural moiety represented by the above formula (II) is preferably 50 mol% or more, more preferably 75 mol% or more, and even more preferably 85 mol% or more, based on the total amount of the structural units T. In one embodiment, the proportion of the structural unit T2 can be 100 mol%.

In one embodiment, from the viewpoint of easily obtaining a charge transport polymer having excellent electrical conductivity and curability, it is preferable that the structural unit T contains a structural unit T1 having a structural portion represented by formula (I) and a structural unit T2 having a structural portion represented by formula (II). Although not particularly limited, the ratio of the structural unit T1 to the structural unit T2 in the structural unit T (T1:T2) is preferably 10:90 to 90:10. The above ratio is more preferably 20:80 to 80:20, and even more preferably 25:75 to 75:25.

(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, etc. From the viewpoint of excellent charge transportability, the number average molecular weight is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. In addition, from the viewpoint of maintaining good solubility in a solvent and facilitating preparation of an ink composition, the number average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less.

(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, etc. From the viewpoint of excellent charge transportability, 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. In addition, from the viewpoint of maintaining good solubility in a solvent and facilitating preparation of an ink composition, the weight average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, and even more preferably 400,000 or less.

The number average molecular weight and the weight average molecular weight can be measured by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene under the following conditions.
Pump: L-6050 Hitachi High-Technologies Corporation UV-Vis detector: L-3000 Hitachi High-Technologies Corporation Column: Gelpack (registered trademark) GL-A160S/GL-A150S Hitachi Chemical Co., Ltd.
Eluent: THF (for HPLC, no stabilizer) Wako Pure Chemical Industries, Ltd.
Flow rate: 1mL/min
Column temperature: Room temperature Molecular weight standard: Standard polystyrene

(Proportion of structural units)
The ratio of the structural unit L contained in the charge transporting polymer is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 30 mol % or more, based on the total structural units, from the viewpoint of obtaining sufficient charge transportability. Also, the ratio of the structural unit L is preferably 95 mol % or less, more preferably 90 mol % or less, and even more preferably 85 mol % or less, taking into consideration the structural unit T and the structural unit B introduced as necessary.

The proportion of the structural unit T contained in the charge transport polymer is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more, based on the total structural units, from the viewpoint of improving the characteristics of the organic electronics element, or from the viewpoint of suppressing an increase in viscosity and smoothly synthesizing the charge transport polymer. Also, from the viewpoint of obtaining sufficient charge transportability, the proportion of the structural unit T is preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less. In one embodiment, the proportion of the structural unit T means the combined proportion of the structural units T1 and T2 having the structural portion represented by the above formula (I).

When the charge transport polymer contains structural unit B, the proportion of structural unit B is preferably 1 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on all structural units, from the viewpoint of improving the durability of the organic electronics element. Furthermore, the proportion of structural unit B is preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less, from the viewpoint of suppressing an increase in viscosity and smoothly synthesizing the charge transport polymer, or from the viewpoint of obtaining sufficient charge transportability.

Considering the balance of charge transportability, durability, productivity, etc., the ratio (molar ratio) of the structural unit L and the structural unit T is preferably L:T=100:1-70, more preferably 100:3-50, and even more preferably 100:5-30. Furthermore, when the charge transport polymer contains the structural unit B, the ratio (molar ratio) of the structural unit L, the structural unit T, and the structural unit B is preferably L:T:B=100:10-200:10-100, more preferably 100:20-180:20-90, and even more preferably 100:40-160:30-80.

The ratio of structural unit can be obtained by using the amount of monomer corresponding to each structural unit used to synthesize charge transport polymer.In addition, the ratio of structural unit can be calculated as an average value by utilizing the integral value of the spectrum derived from each structural unit in the ¹ H NMR spectrum of charge transport polymer.Because it is simple, when the amount of charge is clear, it is preferable to adopt the value obtained by using the amount of charge.

When the charge transport polymer is a hole transport compound, from the viewpoint of obtaining high hole injection and hole transport properties, the hole transport compound is preferably a compound having at least one of a unit having an aromatic amine structure and a unit having a carbazole structure as a main structural unit. From this viewpoint, the ratio of the total number of at least one of the units having an aromatic amine structure and the units having a carbazole structure to the total number of structural units in the charge transport polymer (excluding terminal structural units) is preferably 40% or more, more preferably 45% or more, and even more preferably 50% or more. It is also possible to set the ratio of the total number of at least one of the units having an aromatic amine structure and the units having a carbazole structure to 100%.

The charge transport polymer having the structural portion represented by the above formula (I) contains a polymerizable functional group in the molecule. From the viewpoint of contributing to the change in solubility, it is preferable that the polymerizable functional group is contained in a large amount in the charge transport polymer. On the other hand, from the viewpoint of not interfering with the charge transportability, it is preferable that the amount of the polymerizable functional group contained in the charge transport polymer is small. Therefore, the content of the polymerizable functional group can be appropriately set taking these into consideration.

For example, the number of polymerizable functional groups per molecule of the charge transport polymer is preferably 2 or more, more preferably 3 or more, from the viewpoint of obtaining a sufficient change in solubility. Also, the number of polymerizable functional groups is preferably 1,000 or less, more preferably 500 or less, from the viewpoint of maintaining charge transportability. Here, the number of polymerizable functional groups means the sum of the polymerizable functional groups contained in the structural portion represented by the above formula (I) and the polymerizable functional groups present as other substituents.

The number of polymerizable functional groups per molecule of the charge transporting polymer can be determined as an average value using the amount of monomer having a polymerizable functional group charged relative to the total amount of monomer corresponding to each structural unit used to synthesize the charge transporting polymer, the weight average molecular weight of the charge transporting polymer, etc.
The number of polymerizable functional groups can be calculated as an average value using the ratio of the integral value of the signal derived from the polymerizable functional group in the ^1H NMR (nuclear magnetic resonance) spectrum of the charge transport polymer to the integral value of the entire spectrum, the weight average molecular weight of the charge transport polymer, etc.
When the charge amount is known, it is preferable to employ the value determined using the charge amount, because this is simple and easy.

In one embodiment, the proportion of polymerizable functional groups in the charge transport polymer is preferably 0.1 mol% or more, more preferably 1 mol% or more, and even more preferably 3 mol% or more, based on all structural units, from the viewpoint of efficiently curing the charge transport polymer. Also, the proportion of polymerizable functional groups is preferably 70 mol% or less, more preferably 60 mol% or less, and even more preferably 50 mol% or less, from the viewpoint of obtaining good charge transport properties. Note that the "proportion of polymerizable functional groups" here refers to the proportion of structural units having polymerizable functional groups to all structural units.

(Production method)
The charge transporting polymer can be produced by various synthesis 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 is a cross-coupling reaction between an aromatic boronic acid derivative and an aromatic halide using a Pd catalyst. According to Suzuki coupling, the charge transporting polymer can be easily produced by bonding desired aromatic rings together.

In the coupling reaction, for example, Pd(0) compounds, Pd(II) compounds, Ni compounds, etc. are used as catalysts. In addition, catalyst species generated by mixing precursors such as tris(dibenzylideneacetone)dipalladium(0) and palladium(II) acetate with a phosphine ligand can also be used. For the synthesis method of the charge transporting polymer, for example, see the description in International Publication No. 2010/140553.

[Dopant]
The organic electronic material may further contain a dopant. The dopant is not particularly limited as long as it is a compound that can exhibit a doping effect by being added to the organic electronic material and improve the transportability of charges. There are p-type doping and n-type doping, and in p-type doping, a substance that acts as an electron acceptor is used as a dopant, and in n-type doping, a substance that acts as an electron donor is used as a dopant. It is preferable to perform p-type doping to improve hole transportability, and n-type doping to improve electron transportability. The dopant used in the organic electronic material may be a dopant that exhibits either the effect of p-type doping or n-type doping. In addition, one type of dopant may be added alone, or a mixture of multiple types of dopants may be added.

The dopant used in p-type doping is an electron-accepting compound, and examples thereof include Lewis acids, protonic acids, transition metal compounds, ionic compounds, halogen compounds, and π-conjugated compounds. Specifically, Lewis acids include FeCl ₃ , PF ₅ , AsF ₅ , SbF ₅ , BF ₅ , BCl ₃ , BBr _{3 ,} etc.; protonic acids include inorganic acids such as HF, HCl, HBr, HNO ₅ , H ₂ SO ₄ , HClO _{4 ,} etc., and organic acids such as benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, polyvinylsulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, 1-butanesulfonic acid, vinylphenylsulfonic acid, camphorsulfonic acid, etc.; transition metal compounds include FeOCl, TiCl ₄ , ZrCl ₄ , HfCl ₄ , NbF ₅ , AlCl ₃ , NbCl ₅ , TaCl ₅ , MoF _{5 .} Examples of ionic compounds include salts having perfluoro anions such as tetrakis(pentafluorophenyl)borate ion, tris(trifluoromethanesulfonyl)methide ion, bis(trifluoromethanesulfonyl)imide ion, hexafluoroantimonate ion, AsF ₆ ^- (hexafluoroarsenate ion), BF ₄ ^- (tetrafluoroborate ion), and PF ₆ ^- (hexafluorophosphate ion), and salts having the conjugate base of the above-mentioned protonic acids as an anion; examples of halogen compounds include Cl ₂ , Br ₂ , I ₂ , ICl, ICl ₃ , IBr, and IF; and examples of π-conjugated compounds include TCNE (tetracyanoethylene), TCNQ (tetracyanoquinodimethane), and the like. It is also possible to use electron-accepting compounds described in JP-A-2000-36390, JP-A-2005-75948, JP-A-2003-213002, etc. Among the above, Lewis acids, ionic compounds, π-conjugated compounds, etc. are preferred, ionic compounds are more preferred, and onium salts are even more preferred. The onium salt refers to a compound consisting of a cation moiety containing an onium ion such as iodonium or ammonium, and a corresponding anion moiety.

The dopant used in n-type doping is an electron-donating compound, and examples thereof include alkali metals such as Li and Cs, alkaline earth metals such as Mg and Ca, at least one of salts of alkali metals and alkaline earth metals such _as LiF and _Cs2CO3 , metal complexes, and electron-donating organic compounds.

In order to facilitate the change in solubility of the organic layer, it is preferable to use a compound that can act as a polymerization initiator for the polymerizable functional group as a dopant. Examples of substances that function both as a dopant and a polymerization initiator include the above-mentioned ionic compounds.

[Other optional ingredients]
The organic electronic material may further contain a charge transporting low molecular weight compound, another polymer, and the like.

[Content]
From the viewpoint of obtaining good charge transportability, the content of the charge transporting polymer is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on the total mass of the organic electronic material. It is also possible for the content to be 100% by mass.

When a dopant is contained, the content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, based on the total mass of the organic electronic material, from the viewpoint of improving the charge transport properties of the organic electronic material. Furthermore, from the viewpoint of maintaining good film-forming properties, the content is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total mass of the organic electronic material.

[Polymerization initiator]
The organic electronic material preferably contains a polymerization initiator. As the polymerization initiator, a known radical polymerization initiator, cationic polymerization initiator, anionic polymerization initiator, etc. can be used. From the viewpoint of easily preparing the ink composition, it is preferable to use a substance that functions as both a dopant and a polymerization initiator. As a cationic polymerization initiator also having a dopant function, for example, the above-mentioned ionic compounds can be suitably used. For example, an onium salt of a perfluoro anion and a cation such as an iodonium ion or an ammonium ion can be mentioned. Specific examples of the onium salt include the following compounds.

<Ink composition>
The organic electronic material may be an ink composition containing the organic electronic material of the above embodiment and a solvent capable of dissolving or dispersing the material. By using the ink composition, an organic layer can be easily formed by a simple method such as a coating method.

[solvent]
The solvent may be water, an organic solvent, or a mixture thereof. The organic solvent may be alcohol such as methanol, ethanol, or isopropyl alcohol;
Alkanes such as pentane, hexane, octane, etc.;
Cyclic alkanes such as cyclohexane;
Aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, tetralin, and diphenylmethane;
Aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate;
Aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole;
Aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate;
Aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate;
Amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide;
Examples of the solvent include dimethyl sulfoxide, tetrahydrofuran, acetone, chloroform, and methylene chloride.
Among the above, preferred are aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers, etc. In one embodiment, the solvent is preferably an aromatic hydrocarbon, and among these, toluene is preferred.

[Additives]
The ink composition may further contain additives as optional components, such as a polymerization inhibitor, a stabilizer, a thickener, a gelling agent, a flame retardant, an antioxidant, a reducing agent, an oxidizing agent, a reducing agent, a surface modifier, an emulsifier, an antifoaming agent, a dispersant, and a surfactant.

[Content]
The content of the solvent in the ink composition can be determined taking into consideration application to various coating methods. For example, the content of the solvent is preferably such that the ratio of the charge transporting polymer to the solvent is 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.5% by mass or more.
Regarding the content of the solvent, the ratio of the charge transporting polymer to the solvent is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

<Organic Layer>
In one embodiment, the organic layer is a layer formed using the organic electronic material of the above embodiment. The organic electronic material of the above embodiment may be used as an ink composition. By using the ink composition, the organic layer can be well formed by a coating method. Examples of the coating method include known methods such as spin coating method, casting method, immersion method, plate printing method such as letterpress printing, intaglio printing, offset printing, lithographic printing, letterpress reverse offset printing, screen printing, and gravure printing, and plateless printing method such as inkjet method. When the organic layer is formed by a coating method, the organic layer (coated layer) obtained after coating may be dried using a hot plate or an oven to remove the solvent.

The solubility of the organic layer may be changed by accelerating the polymerization reaction of the charge transport polymer through light irradiation, heat treatment, etc. By stacking organic layers with different solubilities, it becomes possible to easily achieve multi-layering of organic electronics elements. For the method of forming the organic layer, see, for example, the description in International Publication No. 2010/140553.

From the viewpoint of improving the efficiency of charge transport, 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 reducing the 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 elements>
In one embodiment, an organic electronics element has at least the organic layer of the above embodiment. Examples of the organic electronics element include an organic EL element, an organic photoelectric conversion element, an organic transistor, etc. The organic electronics element preferably has a structure in which an organic layer is disposed between at least a pair of electrodes.

[Organic EL element]
In one embodiment, the organic EL element has at least the organic layer of the above embodiment. The organic EL element usually has a light-emitting layer, an anode, a cathode, and a substrate, and, if necessary, has other functional layers such as a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer. Each layer may be formed by a deposition method or a coating method. The organic EL element preferably has an organic layer as a light-emitting layer or other 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 cross-sectional schematic diagram showing one embodiment of an organic EL element. The organic EL element in Fig. 1 is a multi-layered element having, in this order, a substrate 8, an anode 2, a hole injection layer 3 and a hole transport layer 6 made of the organic layer of the above embodiment, a light-emitting layer 1, an electron transport layer 7, an electron injection layer 5, and a cathode 4. Each layer will be described below.
In FIG. 1 , the hole injection layer 3 and the hole transport layer 6 are organic layers formed using the organic electronic materials described above, but the organic EL described in this specification is not limited to such a structure, and other organic layers may be organic layers formed using the organic electronic materials described above.

[Light-emitting layer]
The material used for the light-emitting layer may be a light-emitting material such as a low molecular weight compound, a polymer, or a dendrimer. Polymers are preferred because they are highly soluble in solvents and suitable for coating methods. Light-emitting materials include fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescent materials (TADFs).

The above-mentioned fluorescent materials include low molecular weight compounds such as perylene, coumarin, rubrene, quinacridone, stilbene, dyes for dye lasers, aluminum complexes, and derivatives thereof; polymers such as polyfluorene, polyphenylene, polyphenylenevinylene, polyvinylcarbazole, fluorene-benzothiadiazole copolymer, fluorene-triphenylamine copolymer, and derivatives thereof; and mixtures thereof.

The phosphorescent material may be a metal complex containing a metal such as Ir or Pt. Examples of Ir complexes include FIr(pic) (iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C ² ]picolinate) which emits blue light, Ir(ppy) ₃ (factris(2-phenylpyridine)iridium) which emits green light, (btp) ₂ Ir(acac) (bis[2-(2'-benzo[4,5-α]thienyl)pyridinato-N,C ³ ]iridium(acetylacetonate)) which emits red light, and Ir(piq) ₃ (tris(1-phenylisoquinoline)iridium). An example of a Pt complex is PtOEP (2,3,7,8,12,13,17,18-octaethyl-21H,23H-phorphine platinum), which emits red light.

When the light-emitting layer contains the phosphorescent material, it is preferable that the light-emitting layer further contains a host material in addition to the phosphorescent material. The host material may be a low molecular weight compound, a polymer, or a dendrimer. Examples of the low molecular weight compound include CBP (4,4'-bis(9H-carbazol-9-yl)biphenyl), mCP (1,3-bis(9-carbazolyl)benzene), CDBP (4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl), and derivatives thereof.
Examples of the polymer include the organic electronic material of the above embodiment, polyvinylcarbazole, polyphenylene, polyfluorene, and derivatives thereof.

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.

In one embodiment, the organic EL element preferably has an emission layer containing a phosphorescent material. In another embodiment, the organic EL element preferably has an emission layer containing a thermally activated delayed fluorescent material.

[Hole transport layer, hole injection layer]
1, the hole injection layer 3 and the hole transport layer 6 may be organic layers formed using the organic electronic materials described above, but the organic EL element of the present embodiment is not limited to such a structure. Organic layers other than the hole injection layer and the hole transport layer may be formed using the organic electronic materials described above.
The organic electronic material is preferably used as at least one of a hole transport layer and a hole injection layer, and more preferably used as at least a hole transport layer. For example, when an organic EL element has an organic layer formed using the organic electronic material as a hole transport layer and further has a hole injection layer, a known material can be used for the hole injection layer. Also, for example, when an organic EL element has an organic layer formed using the organic electronic material as a hole injection layer and further has a hole transport layer, a known material can be used for the hole transport layer.
Materials that can be used for the hole injection layer and the hole transport layer include aromatic amine compounds (aromatic diamines such as N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (α-NPD)), phthalocyanine compounds, and thiophene compounds (thiophene conductive polymers (poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)), etc.).

[Electron transport layer, electron injection layer]
Materials used for the electron transport layer and the electron injection layer include phenanthroline derivatives, bipyridine derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, condensed ring tetracarboxylic acid anhydrides such as naphthalene and perylene, carbodiimides, fluorene derivatives, and the like. Olenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, thiadiazole derivatives, benzimidazole derivatives (e.g., 2,2',2"-(1,3,5-benzenetriyl)tris(1- phenyl-1H-benzimidazole (TPBi)), quinoxaline derivatives, aluminum complexes (e.g., bis(2-methyl-8-quinolinolato)-4-(phenylphenolato)aluminum (BAlq)), and the like. The organic electronic materials of the above embodiments can also be used.

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

[anode]
The anode material may be a metal (e.g., Au) or other electrically conductive material, such as an oxide (e.g., ITO: indium oxide/tin oxide) or a conductive polymer (e.g., polythiophene-polystyrene sulfonate mixture (PEDOT:PSS)).

[substrate]
In one embodiment, the organic electronic device preferably further includes a substrate. The substrate may be made of glass, plastic, or the like. The substrate is preferably transparent. A substrate having flexibility (flexible substrate) is also preferable. Specifically, a substrate such as quartz glass or a light-transmitting resin film is preferable.

Examples of resin films include films made of polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, cellulose acetate propionate, etc.

When using a resin film, the resin film may be coated with an inorganic material such as silicon oxide or silicon nitride to prevent the transmission of water vapor, oxygen, etc.

[Emitted color]
The color of the emitted light from the organic EL element is not particularly limited. A white organic EL element is preferable because it can be used in various lighting fixtures such as home lighting, car lighting, clocks, and liquid crystal backlights.

A method for forming a white organic EL element can be to use a method in which multiple luminescent materials are used to simultaneously emit multiple luminescent colors and mix the colors. Combinations of multiple luminescent colors are not particularly limited, but include combinations containing three maximum emission wavelengths of blue, green, and red, and combinations containing two maximum emission wavelengths, such as blue and yellow, or yellow-green and orange. The luminescent color can be controlled by adjusting the type and amount of the luminescent material.

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

In one embodiment, the lighting device includes the organic EL element of the above embodiment. Furthermore, in one embodiment, the display device 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 lighting device of the above embodiment as a backlight and a known liquid crystal element as a display means, i.e., a liquid crystal display device.

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

<1> Preparation of Organic Electronic Materials Synthesis examples of materials used in the following examples are shown below.

1. Preparation of Pd catalyst (Preparation Example 1)
This step was carried out in a glove box under a nitrogen atmosphere. At room temperature, a fluororesin-coated ceramic stirrer was placed in a glass sample vial, 73.2 mg (80 μmol) of tris(dibenzylideneacetone)dipalladium was weighed out, 15 mL of toluene was added, and the mixture was stirred for 30 minutes. Similarly, a fluororesin-coated ceramic stirrer was placed in a glass sample vial, 129.6 mg (640 μmol) of tris(t-butyl)phosphine was weighed out, 5 mL of toluene was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at 80° C. for 2 hours, and the resulting solution was used to remove insoluble matter using a membrane filter with a pore size of 0.2 μm. The solution thus obtained was used as a Pd catalyst solution to synthesize the following charge-transporting polymer. All solvents were used after being degassed by nitrogen bubbling for 30 minutes or more.

2. Synthesis of charge-transporting polymer (charge-transporting polymer 1)
In a 200 mL three-necked round-bottom glass flask, 2.58 g (5.0 mmol) of the following monomer 1, 0.96 g (2.0 mmol) of the following monomer 2, 0.54 g (2.0 mmol) of the following monomer 3, 0.46 g (2.0 mmol) of the following monomer 4, and 48.3 mL of toluene were added, and 3.9 mL of a 1 mass% toluene solution of trioctylmethylammonium chloride and 7.2 mL of a 3M aqueous potassium hydroxide solution were added. All solvents were used after being degassed by nitrogen bubbling for 30 minutes or more. A reflux condenser and a nitrogen gas flow tube were attached to the flask containing the reaction solution, and the flask was immersed in an oil bath heated to 60 ° C. and stirred for 30 minutes to dissolve the monomer. Next, 1.0 mL of the Pd catalyst solution obtained in Preparation Example 1 was added, and the temperature of the oil bath was set to 120 ° C. to carry out the reaction. The reaction solution was heated and refluxed for 2 hours. All reactions were carried out under a nitrogen stream.

After the reaction was completed, the organic layer was washed with water and poured into a methanol-water (9:1) solution. The resulting precipitate was filtered off and washed with methanol. The resulting precipitate was washed with ethyl acetate, and the eluted solid was vacuum dried. The dried solid was dissolved in toluene, and a metal adsorbent ("Triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer" manufactured by Strem Chemicals, 200 mg per 100 mg of precipitate) was added and stirred at 40°C for 2 hours. After stirring was completed, the solution was filtered through a membrane filter with a pore size of 0.2 μm to remove the metal adsorbent and solid impurities, and the solution was poured into methanol. The precipitate was suction filtered, the resulting precipitate was washed with methanol, and the solid was vacuum dried to obtain charge transport polymer 1.

(Charge Transporting Polymer 2)
Charge transporting polymer 2 was synthesized in the same manner as in the synthesis of charge transporting polymer 1, except that the reaction was carried out using monomer 5 shown below instead of monomer 4.

(Charge Transporting Polymer 3)
Charge transporting polymer 3 was synthesized in the same manner as in the synthesis of charge transporting polymer 1, except that the reaction was carried out using monomer 6 shown below instead of monomer 4.

(Charge Transporting Polymer 4)
Charge transporting polymer 4 was synthesized in the same manner as in the synthesis of charge transporting polymer 1, except that the reaction was carried out using monomer 7 shown below instead of monomer 4.

(Charge transport polymer 5)
Charge transporting polymer 5 was synthesized in the same manner as in the synthesis of charge transporting polymer 1, except that the reaction was carried out using monomer 8 shown below instead of monomer 4.

(Charge transport polymer 6)
Charge transporting polymer 6 was synthesized in the same manner as in the synthesis of charge transporting polymer 1, except that the reaction was carried out using monomer 9 shown below instead of monomer 4.

(Charge transport polymer 7)
Charge transporting polymer 7 was synthesized in the same manner as in the synthesis of charge transporting polymer 1, except that the reaction was carried out using monomer 10 shown below instead of monomer 4.

3. Synthesis of ionic compounds (ionic compound 1)
A fluororesin-coated magnetic stirrer was placed in a 200 mL wide-mouth flask, 1.8 g of N,N-dimethyl-N-octadecylamine (Tokyo Chemical Industry Co., Ltd.) was weighed, 15 mL of acetone and 3 mL of pure water were added, and the mixture was stirred for 10 minutes. 2.2 g of a 10% by mass aqueous hydrochloric acid solution was added dropwise while stirring the obtained solution. Then, the solvent was reduced in pressure using a rotary evaporator until a white precipitate was precipitated. 46.5 g of a 10% by mass aqueous tetrakis(pentafluorophenylborate) sodium salt solution was added to the obtained solution (including the precipitate) while stirring, and the mixture was stirred for 30 minutes. Then, the organic layer was washed four times with pure water, and the precipitate was separated by filtration. The obtained precipitate was washed with pure water and then dried under vacuum. The dried solid was dissolved in methanol, and insoluble matter was removed using a 0.2 μm membrane filter, and the solution was poured into pure water and the white precipitate was separated by filtration. The obtained white precipitate was dried in vacuum to obtain ionic compound 1. The chemical structure of ionic compound 1 is shown in the following formula.

<2> Evaluation of Organic Electronic Materials 1. Preparation of Organic Electronic Materials Organic electronic materials (ink compositions) were prepared using the previously prepared charge transport polymers 1 to 7 and ionic compound 1. More specifically, the charge transport polymer (10.0 mg), ionic compound 1 (0.1 mg), and toluene (1.12 ml) were mixed to prepare the ink compositions.

2. Preparation of organic HOD element In the atmosphere, the ink composition prepared above was spin-coated at 3000 rpm on a glass substrate on which ITO was patterned to a width of 1.6 mm to form a coating film. The glass substrate with the coating film (organic layer) was then placed on a hot plate in a glove box substituted with a nitrogen atmosphere, and heated at a temperature of 200° C. for 30 minutes to cure the organic layer.

The substrate having the organic layer (hole injection layer) made of the cured coating film obtained as described above was transferred into a vacuum deposition machine, and a film of Al (100 nm) was formed on the organic layer of the substrate by deposition, followed by sealing treatment to produce an organic HOD (Hole Only Device).

3. Evaluation of organic HOD When a voltage was applied to the prepared organic HOD, it was found that a current flowed, and it was confirmed that the organic layer had a hole injection function. The current density of the organic HOD was measured at a driving voltage of 0.5 V. The results are shown in Table 1.

As shown in Table 1, in comparison with the comparative example in which a charge transporting polymer without a silyl group was used, the examples in which a charge transporting polymer having a silyl group was used had a higher current density and excellent conductivity. Therefore, by introducing a silyl group into the charge transporting polymer, the conductivity can be improved, and an organic electronics material that is useful for lowering the driving voltage and extending the life of an organic EL element can be realized.

Claims (14)

The organic electronic material contains a charge-transporting polymer having a structure branched in three or more directions, the charge-transporting polymer having a trivalent or higher structural unit that includes at least one of an aromatic amine structure and a carbazole structure and constitutes a branched portion, a divalent structural unit that includes at least one of an aromatic amine structure and a carbazole structure, and a monovalent structural unit that includes a structure having a silyl group represented by the following formula (IA-1) and constitutes a terminal portion :
[In the formula, each R is independently a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, or a halogen atom, and n is an integer of 1 to 5. ] The organic electronic material according to claim 1 , wherein the divalent structural unit comprises a structural unit represented by the following formula (II):
[In the formula, the substituent Ra is a fluorine atom or a fluoroalkyl group.] The organic electronic material according to claim 2 , wherein in the structural unit represented by formula (II), the substituent Ra is a fluorine atom. The organic electronic material according to any one of claims 1 to 3, wherein the trivalent or higher structural unit includes a structural unit represented by the following formula (III) :
The organic electronic material according to any one of claims 1 to 4, wherein the charge transporting polymer further has a polymerizable functional group. 6. The organic electronic material according to claim 1, wherein in the structure having a silyl group represented by formula (IA-1), R each independently represents an alkyl group, and n is 1 or 2. 7. The organic electronic material according to claim 1, wherein the proportion of the structure having a silyl group is 50 mol % or more based on the total amount of the monovalent structural units. An ink composition comprising the organic electronic material according to any one of claims 1 to 7 and a solvent. An organic layer formed using the organic electronics material described in any one of claims 1 to 7 or the ink composition described in claim 8. An organic electronics element having the organic layer according to claim 9. An organic electroluminescence element having the organic layer according to claim 9. A display device comprising the organic electroluminescence element according to claim 11. A lighting device comprising the organic electroluminescence element according to claim 11. A display device comprising the lighting device according to claim 13 and a liquid crystal element as a display means.