JP2017059724A - Organic electronics material, ink composition including the same, organic electronics device, and electroluminescent device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electronics material and an ink composition which enable the enhancement of an organic electronics device and an organic EL device in light emission efficiency.SOLUTION: As an organic electronics material, a charge transport polymer including the structure (I) below in a molecule is arranged. [In the formula, Rto Rindependently represent a hydrogen atom or an alkyl group with 1-4C; at least one of Rto Ris an alkyl group with 1-4C.]SELECTED DRAWING: None

Description

  The present invention relates to an organic electronic material and an ink composition containing the material. The present invention also relates to an organic electronics element and an organic electroluminescence element produced using the ink composition.

  Organic electronics elements are elements that perform electrical operations using organic substances, and are expected to exhibit features such as energy saving, low cost, and flexibility, and are attracting attention as a technology that can replace conventional inorganic semiconductors based on silicon. ing.

  Examples of organic electronics elements include organic electroluminescence elements (hereinafter also referred to as organic EL elements), organic photoelectric conversion elements, organic transistors, and the like.

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

  Organic EL elements are roughly classified into two types, low molecular organic EL elements and polymer organic EL elements, from the organic materials used. So far, various studies have been conducted on both elements in order to improve element characteristics such as luminous efficiency and element lifetime.

For example, a method is known in which device characteristics are improved by multilayering an organic layer of an organic EL device. In the low molecular weight organic EL element, a low molecular weight organic material is used, and film formation is mainly performed according to a vacuum deposition method. Therefore, multilayering can be easily achieved by performing vapor deposition while sequentially changing the organic material to be used.
On the other hand, in a polymer type organic EL element, a high molecular weight organic material is used, and film formation is performed according to a wet process such as printing or inkjet. High-molecular organic EL elements can be formed by simple methods such as printing and ink-jet as compared with low-molecular organic EL elements that require film formation in a vacuum system. It is expected as an indispensable element for organic EL displays. However, when a multilayer organic layer is produced according to a wet process, the lower layer is dissolved when the upper layer is applied, and the multilayering tends to be difficult.

On the other hand, there are several reports on polymer-type organic EL devices having multiple organic layers. Non-Patent Document 1 discloses a device having a three-layer structure using compounds having greatly different solubilities. Patent Document 1 discloses an element having a three-layer structure in which a layer called an interlayer is introduced on PEDOT: PSS. Furthermore, Non-Patent Documents 2 to 4 and Patent Document 2 describe a device using a siloxane compound or a compound containing a polymerizable functional group such as an oxetane group and a vinyl group for the purpose of insolubilizing a thin film with respect to a solvent. Disclosure.
However, in particular, when water-soluble PEDOT: PSS is used, it is necessary to remove moisture remaining in the thin film because the element is easily deteriorated by moisture. Also, when a siloxane compound is used, the compound is unstable with respect to moisture in the air, and the device tends to deteriorate. Thus, in the field of polymer organic EL devices, further improvements in device characteristics such as light emission efficiency and device life are required.

  In the first place, in order to manufacture a polymer type organic EL device having excellent device characteristics by a simple method, a high molecular weight organic material suitable for a wet process is required, and the properties of the organic material should be further improved. is necessary. Among the characteristics, in order to improve the light emission efficiency, for example, an organic material having a wide band gap is desired as a hole transport material. In contrast, Patent Document 3 discloses a compound in which two fluorenyl groups are introduced with respect to one phenyl group in a triphenylamine structure. More specifically, the present invention relates to a compound in which two fluorenyl groups are introduced relative to each other in a meta position relative to a phenyl group. Patent Document 3 discloses that such a compound can provide a wide band gap while ensuring high mobility due to the fluorenyl group and high Tg (glass transition temperature). However, since the disclosed compounds are low molecular weight compounds, it is difficult to perform wet processes using such compounds.

JP 2007-1119763 A International Publication No. 2008/010487 JP 2007-291064 A

Y. Goto, T. Hayashida, M. Noto, IDW '04 Proceedings of The 11th International Display Workshop, 1343-1346 (2004) H. Yan, P. Lee, N. R. Armstrong, A. Graham, G. A. Evemenko, P. Dutta, T. J. Marks, J. Am. Chem. Soc., 127, 3172-4183 (2005) E. Bacher, M. Bayerl, P. Rudati, N. Reckfuss, C. David, K. Meerholz, O. Nuyken, Macromolecules, 38, 1640 (2005) M. S. Liu, Y. H. Niu, J. W. Ka, H. L. Yip, F. Huang, J. Luo, T. D. Wong, A. K. Y. Jen, Macromolecules, 41, 9570 (2008)

  As described above, in the field of polymer organic EL devices, development of high molecular weight organic materials suitable for wet processes is desired for further improvement of device characteristics. For example, it is desired to realize an organic electronic material that has a wide band gap and can improve luminous efficiency. Therefore, an object of the embodiment of the present invention is to provide an organic electronic material and an ink composition that can improve the light emission efficiency of the organic EL element. Another object of the present invention is to provide an organic electronics element and an organic EL element having excellent luminous efficiency using the organic electronics material and ink composition.

  As a result of intensive studies, the present inventors have found that the light-emitting efficiency of the organic electronic device can be improved by introducing a substituent into a specific position of the structure in which two benzene rings are bonded in the charge transporting polymer. The headline and the present invention have been completed. That is, the present invention relates to the matters described below.

[1] An organic electronic material comprising a charge transporting polymer having a structure (I) represented by the following formula in a molecule.

[Wherein, R ^{1 to} R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{1 to} R ⁴ is an alkyl group having 1 to 4 carbon atoms. is there. ]

[2] The organic electronic material according to [1], wherein the structure (I) includes a substituted biphenylene structure (I-1) represented by the following formula.

[Wherein, R ^{1 to} R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{1 to} R ⁴ is an alkyl group having 1 to 4 carbon atoms. is there. ]

  [3] The organic electronics according to [1] or [2], wherein the charge transporting polymer includes a divalent structural unit having charge transporting property and a trivalent or higher structural unit having charge transporting property. material.

  [4] The organic electronic material according to [3], wherein at least one of the divalent structural unit and the trivalent or higher structural unit includes the structure (I).

  [5] The organic electronic material according to [3], wherein the partial structure formed by combining the divalent structural unit and the trivalent or higher structural unit includes the structure (I).

  [6] At least one of the divalent structural unit and the trivalent or higher structural unit is a substituted or unsubstituted aromatic amine structure, carbazole structure, benzene structure, and one or more of these. The organic electronic material according to any one of the above [3] to [5], comprising a structure selected from the containing structures.

  [7] The organic according to any one of [3] to [5], wherein the divalent structural unit and the trivalent or higher structural unit each include a substituted or unsubstituted aromatic amine structure. Electronics material.

  [8] The organic electronic material according to any one of [1] to [7], wherein the charge transporting polymer further has one or more polymerizable functional groups in the molecule.

  [9] An ink composition comprising the organic electronic material according to any one of [1] to [7] above and a solvent.

  [10] The ink composition according to [9], further including a polymerization initiator.

  [11] An organic electronic device comprising a substrate and an organic layer formed using the ink composition according to [9] or [10].

  [12] The organic electronic device according to [11], wherein the substrate is a resin film.

  [13] An organic electroluminescent device having an organic layer formed using the ink composition according to [9] or [10].

  [14] The organic electroluminescent element according to the above [13], wherein the organic layer is a hole injection layer.

  [15] The organic electroluminescent element according to the above [13], wherein the organic layer is a hole transport layer.

  [16] The organic electroluminescence device according to any one of [13] to [15], further including a pair of electrodes including an anode and a cathode, wherein the organic layer is disposed between the pair of electrodes. .

  According to the organic electronic material and the ink composition which are the embodiments of the present invention, the luminous efficiency of the organic EL element can be improved. Moreover, according to another embodiment of the present invention, an organic electronics element and an organic EL element having excellent luminous efficiency can be provided using the organic electronics material and the ink composition.

It is a cross-sectional schematic diagram which shows an example of the structure of the organic EL element which is embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
<Organic electronics materials>
The organic electronic material which is one embodiment of the present invention contains a charge transporting polymer. The charge transporting polymer contains the structure (I) shown below in the molecule.

In the formula, R ^{1 to} R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{1 to} R ⁴ is an alkyl group having 1 to 4 carbon atoms. . “*” Represents a binding site with another structure. Here, the alkyl group having 1 to 4 carbon atoms may be a straight chain alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group, or a branched alkyl group such as an i-propyl group and a t-butyl group. It may be a group. The alkyl group having 1 to 4 carbon atoms is preferably a linear alkyl group, more preferably a methyl group.

The charge transporting polymer may be in any form as long as it contains the structure (I) in the molecule. In one embodiment, the charge transporting polymer preferably includes a substituted biphenylene structure (I-1) shown below.

^Wherein, R 1 to R ⁴ are the same as ^R 1 to R ⁴ described in Structure (I) above. That is, R ^{1 to} R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{1 to} R ⁴ is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable. “*” Represents a binding site with another structure.

As shown in the structures (I) and (I-1), in the structure in which two benzene rings are bonded, at least one substituent is located at the ortho position (R ^{1 to} R ⁴ ) starting from the bonding site. When present, the two benzene rings are likely to have a twisted structure due to steric hindrance. From this, when the charge transporting polymer has the structure (I) in the molecule, the conjugated molecule is difficult to take a conjugated structure, and the conjugation in the molecule is easily cleaved. Then, by introducing a twisted structure in the molecule, it becomes easy to obtain a charge transporting polymer having a wide band gap. Therefore, the luminous efficiency of the organic EL device can be easily improved by using the organic electronic material of the present invention containing the charge transporting polymer having the structure (I). The organic electronic element may contain only one kind of charge transporting polymer or two or more kinds. Hereinafter, embodiments of the charge transporting polymer will be described more specifically.

[Charge transporting polymer]
Charge transporting polymers have the ability to transport charge. The charge transporting polymer includes a structural unit having a charge transporting property. The charge transporting polymer may be linear or have a branched structure. The charge transporting polymer preferably includes at least a divalent structural unit L having charge transporting properties and a monovalent structural unit T constituting a terminal portion, and a trivalent or higher structural unit B constituting a branched portion. Further, it may be included. The charge transporting polymer may contain only one type of each structural unit, or may contain a plurality of types. In the charge transporting polymer, each structural unit is bonded to each other at a binding site of “monovalent” to “trivalent or higher”.

(Construction)
Examples of the partial structure contained in the charge transporting polymer include the following. The charge transporting polymer is not limited to a polymer having the following partial structure. In the partial structure, “L” represents the structural unit L, “T” represents the structural unit T, and “B” represents the structural unit B. “*” Represents a binding site with another structural unit. In the following partial structures, a plurality of L may be the same structural unit or different structural units. The same applies to T and B.

Linear charge transporting polymer

Charge transporting polymer having a branched structure

  In the present invention, the charge transporting polymer has the structure (I) shown above in the molecule. In one embodiment, the charge transporting polymer comprises structure (I) in at least one structural unit of structural units L, B, and T. Preferably, at least one of the structural unit L and the structural unit B includes the structure (I) in the structural unit. More preferably, at least the structural unit B includes the structure (I). In another embodiment, the charge transporting polymer includes the structure (I) in a partial structure formed by bonding the structural units L, B, and T. More preferably, the partial structure formed by bonding the structural units L and B includes the structure (I). Here, in each embodiment, the structure (I) is more preferably a substituted biphenylene structure (I-1). Hereinafter, each structural unit constituting the charge transporting polymer will be specifically described.

(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 charges. The structural unit L is a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, biphenylene structure, terphenylene structure, naphthalene structure, anthracene structure, tetracene structure, phenanthrene structure, dihydrophenanthrene 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, benzothiophene structure , Benzoxazole structure, benzooxadiazole structure, benzothiazole structure, benzothiadiazole structure, benzotriazole structure, and one or more of these It is selected from the structure containing. The aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure.

  In one embodiment, the structural unit L includes a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, pyrrole structure, and these from the viewpoint of obtaining excellent hole transport properties. It is preferable to select from the structure containing 1 type, or 2 or more types. In another embodiment, from the viewpoint of obtaining excellent electron transport properties, the structural unit L is a substituted or unsubstituted fluorene structure, benzene structure, phenanthrene structure, pyridine structure, quinoline structure, and one or two of these. It is preferably selected from structures containing more than one species.

  Although not particularly limited, in one embodiment, the structural unit L is selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, benzene structure, and a structure including one or more of these. Structure to be included. Hereinafter, the structural unit L will be described more specifically.

(Structural unit L1)
In one embodiment, the structural unit L comprises the structure (I) shown above in the structural unit. Hereinafter, such a structural unit is referred to as L1. For example, the structural unit L1 includes a structure selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, benzene structure, and a structure including one or more of these, and in the structural unit Includes structure (I) shown above. More preferably, the structural unit L1 includes at least one of a substituted or unsubstituted aromatic amine structure and carbazole structure. More preferably, the structural unit L1 includes at least a substituted or unsubstituted aromatic amine structure. Here, the aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure.

Specific examples of the structural unit L1 include the following. However, the structural unit L1 is not limited to the following.

In each formula, R is the same as R ^{1 to} R ⁴ described in the structure (I). That is, R ^{1 to} R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{1 to} R ⁴ is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable.

(Structural unit L2)
In another embodiment, the structural unit L has a structure capable of forming the structure (I) by bonding with another structural unit. Hereinafter, such a divalent structural unit is referred to as L2. For example, the structural unit L2 is selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, benzene structure, and a structure including one or more of them, and a structure ( It has a structure capable of forming I). More preferably, the structural unit L2 includes at least one of a substituted or unsubstituted aromatic amine structure and carbazole structure. More preferably, the structural unit L2 includes at least a substituted or unsubstituted aromatic amine structure. Here, the aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure. Here, the structure capable of forming the structure (I) by bonding with another structural unit refers to at least one substituent R at the ortho position starting from the bonding site with the other structural unit in the benzene ring in the structural unit. Intended to have one structure.

Specific examples of the structural unit L2 include the following. However, the structural unit L2 is not limited to the following.

In the formula, each R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable.
R ′ each independently represents a hydrogen atom or a substituent. The substituent is selected from the group consisting of a halogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, an alkoxy group, an alkylcarbonyl group, and an alkylamide group, and an aryl group having 6 to 30 carbon atoms. At least one substituent. Here, the aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon, and may have a substituent. In the above formula, only one R ′ is shown, but two or more R ′ may be present in the molecule. In this case, adjacent R ′ may be bonded to form a ring. Examples of the substituent for the aryl include an alkyl group, an alkoxyl group, an amino group, an imide group, a sulfo group, a carboxyl group, and a phosphonyl group. In one embodiment, R ′ is a hydrogen atom or a linear alkyl having 1 to 8 carbon atoms. The alkyl group may be linear or branched, and more preferably is a linear alkyl group having 1 to 4 carbon atoms.

(Structural unit L3)
In another embodiment, the structural unit L may include a structure having no substituent at the ortho position starting from a bonding site with another structural unit in the benzene ring in the structural unit. Hereinafter, such a structural unit is referred to as a structural unit L3. The structural unit L3 intends, for example, a structure in which all Rs in the structural unit L2 described above are hydrogen atoms. In contrast to the structural unit L2 described above, the structural unit L3 may be substituted with a substituent R ′ other than R.

Specific examples of the structural unit L3 include the following. However, the structural unit L3 is not limited to the following. In the formula, R ′ is the same as R ′ in the structural unit L2 described above. In one embodiment of the structural unit L3 exemplified below, R ′ is a hydrogen atom or a linear alkyl group having 1 to 8 carbon atoms, and the alkyl group is preferably a linear alkyl group having 1 to 4 carbon atoms. It is.

In one embodiment, the structural unit L can be selected from the divalent structural units exemplified below, including the structural units L1 to L3 described above. Specific examples of the structural unit L include the following. However, the structural unit L is not limited to the following.

Each R independently represents a hydrogen atom or a substituent. Preferably, each R independently represents —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 later. Selected from the group consisting of containing groups. R ^{1 to} R ⁸ each independently represents 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 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 heterocyclic ring. The alkyl group may be further substituted by an aryl group or heteroaryl group having 2 to 20 carbon atoms, and the aryl group or heteroaryl group is further linear, cyclic or branched 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 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, more preferably a phenylene group.

  Examples of the aromatic hydrocarbon include a single ring, a condensed ring, or a polycycle in which two or more selected from a single ring and a condensed ring are bonded via a single bond. Examples of the aromatic heterocycle include a single ring, a condensed ring, or a polycycle in which two or more selected from a monocycle and a condensed ring are bonded via a single bond.

(Structural unit B)
The structural unit B is a trivalent or higher-valent structural unit that constitutes a branched portion when the charge transporting polymer has a branched structure. The structural unit B is preferably hexavalent or less, more preferably trivalent or tetravalent, from the viewpoint of improving the durability of the organic electronic element. The structural unit B is preferably a unit having charge transportability. For example, the structural unit B is a substituted or unsubstituted aromatic amine structure, carbazole structure, condensed polycyclic aromatic hydrocarbon structure, and one or two of these from the viewpoint of improving the durability of the organic electronic device. Selected from structures containing more than one species.

  Although not particularly limited, in one embodiment, the structural unit B is selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, benzene structure, and a structure including one or more of these. Is done. More preferably, the structural unit B includes at least one of a substituted or unsubstituted aromatic amine structure and carbazole structure. More preferably, the structural unit B includes at least a substituted or unsubstituted aromatic amine structure. Here, the aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure. Hereinafter, the structural unit B will be described more specifically.

(Structural unit B1)
In one embodiment, the structural unit B comprises the structure (I) shown above in the structural unit. Hereinafter, such a structural unit is referred to as B1. For example, the structural unit B1 is selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, benzene structure, and a structure containing one or more of these, and the structure shown above in the structural unit (I) is included.

Specific examples of the structural unit B1 include the following. However, the structural unit B1 is not limited to the following.

In the formula, R is the same as R ^{1 to} R ⁴ described in the structure (I). That is, each R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable.

(Structural unit B2)
In another embodiment, the structural unit B has a structure capable of forming the structural unit (I) by bonding with another structural unit. Hereinafter, such a trivalent or higher structural unit is referred to as B2. For example, the structural unit B2 is selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, benzene structure, and a structure including one or more of these, and is formed by bonding with another structural unit. It has a structure capable of forming (I). Here, the structure capable of forming the structure (I) by bonding with another structural unit means that the benzene ring in the structural unit has 1 to 4 carbon atoms in the ortho position starting from the bonding site with the other structural unit. It is intended to have at least one alkyl group.

Specific examples of the structural unit B2 include the following. However, the structural unit B2 is not limited to the following.

  In each formula, each R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable.

The charge transporting polymer preferably includes the following structural unit B2-1 having a triphenylamine structure among the structural units B2 exemplified above.

  In the formula, R is the same as R described in the structural unit B2.

  The following is mentioned as a more concrete structure of the said structural unit B2-1. Especially, although it does not specifically limit, B2-1A, B2-1B, and B2-1C are mentioned as an example of a preferable structural unit.

  In the formula, each R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable.

(Structural unit B3)
In another embodiment, the structural unit B may include a structure having no substituent at the ortho position starting from a bonding site with another structural unit in the benzene ring in the structural unit. Hereinafter, such a structural unit is referred to as a structural unit B3. The structural unit B3 intends, for example, a structure in which all Rs in the structural unit B2 described above are hydrogen atoms. In contrast to the structural unit B2 described above, the structural unit B3 may be substituted with a substituent R ′ other than R.

Specific examples of the structural unit B3 include the following. However, the structural unit B3 is not limited to the following. In the formula, R ′ is the same as R ′ in the structural unit L2 described above. In one embodiment of the structural unit L3 exemplified below, R ′ is a hydrogen atom or a linear alkyl having 1 to 8 carbon atoms. The alkyl group may be linear or branched, and more preferably is a linear alkyl group having 1 to 4 carbon atoms.

  In one embodiment, the structural unit B can be selected from trivalent or higher structural units exemplified below including the structural units B1 to B3 described above. Specific examples of the structural unit B include the following. However, 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 heteroarene triyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic heterocyclic ring. Ar each independently represents a divalent linking group, for example, each independently represents an arylene group or heteroarylene group having 2 to 30 carbon atoms. Ar is preferably an arylene group, more preferably a phenylene group. Y represents a divalent linking group. For example, one R atom in the structural unit L (excluding a group containing a polymerizable functional group) has one more hydrogen atom from a group having one or more hydrogen atoms. And divalent groups excluding. Z represents any of a carbon atom, a silicon atom, or a phosphorus atom. In the structural unit, the benzene ring and Ar may have a substituent, and examples of the substituent include R in the structural unit L.

(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, aromatic heterocyclic structure, and a structure including one or more of these. The structural unit T may have the same structure as the structural unit L and / or the structural unit B. That is, even if the structural unit T includes the structure (I) described above, the structural unit T may have a structure capable of forming the structure (I) by bonding with another structural unit.

  In one embodiment, the structural unit T is preferably a substituted or unsubstituted aromatic hydrocarbon structure from the viewpoint of imparting durability without deteriorating charge transportability, and is preferably a substituted or unsubstituted benzene structure. A structure is more preferable. In other embodiments, as described later, when the charge transporting polymer has a polymerizable functional group at the terminal portion, the structural unit T has a polymerizable structure (for example, a polymerizable functional group such as a pyrrol-yl group). ).

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

  R is the same as R in the structural unit L. When the charge transporting polymer has a polymerizable functional group at the terminal portion, preferably at least one of R is a group containing a polymerizable functional group. In addition, at least one of R located in the ortho position starting from the bonding site in the benzene ring in the structural unit may be an alkyl group having 1 to 4 carbon atoms. In this case, the charge transporting polymer has a structure including the structure (I) at the terminal portion.

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

  The polymerizable functional group includes a group having a carbon-carbon multiple bond (for example, vinyl group, allyl group, butenyl group, ethynyl group, acryloyl group, acryloyloxy group, acryloylamino group, methacryloyl group, methacryloyloxy group, methacryloylamino group). Groups, vinyloxy groups, vinylamino groups, etc.), groups having a small ring (eg, cyclic alkyl groups such as cyclopropyl groups, cyclobutyl groups; cyclic ether groups such as epoxy groups (oxiranyl groups), oxetane groups (oxetanyl groups), etc. Diketene group; episulfide group; lactone group; lactam group, etc.), heterocyclic group (for example, furan-yl group, pyrrol-yl group, thiophen-yl group, silole-yl group) and the like. As the polymerizable functional group, a vinyl group, an acryloyl group, a methacryloyl group, an epoxy group, and an oxetane group are particularly preferable, and from the viewpoint of reactivity and characteristics of the organic electronics element, a vinyl group, an oxetane group, or an epoxy group is 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 by an alkylene chain. In addition, for example, when an organic layer is formed on an electrode, it is connected with a hydrophilic chain such as an ethylene glycol chain or a diethylene glycol chain from the viewpoint of improving the affinity with a hydrophilic electrode such as ITO. preferable. Further, from the viewpoint of facilitating the preparation of the monomer used for introducing the polymerizable functional group, the charge transporting polymer is polymerized with the end of the alkylene chain and / or the hydrophilic chain, that is, with these chains. An ether bond or an ester bond may be present at the connecting portion with the functional group and / or the connecting portion between these chains and the skeleton of the charge transporting polymer. The above-mentioned “group containing a polymerizable functional group” means a polymerizable functional group itself or a group obtained by combining a polymerizable functional group with an alkylene chain or the like. As the group containing a polymerizable functional group, for example, a group exemplified in International Publication No. WO2010 / 140553 can be suitably used.

Although it does not specifically limit, In one Embodiment, the following is mentioned as a specific example of the preferable structural unit T.

  The polymerizable functional group may be introduced into the terminal part (that is, the structural unit T) of the charge transporting polymer, or may be introduced into a part other than the terminal part (that is, the structural unit L or B). And may be introduced into both of the portions other than the terminal. From the viewpoint of curability, it is preferably introduced at least at the end portion, and from the viewpoint of achieving both curability and charge transportability, it is preferably introduced only at the end portion. When the charge transporting polymer has a branched structure, the polymerizable functional group may be introduced into the main chain of the charge transporting polymer or into the side chain, and both the main chain and the side chain may be introduced. May be introduced.

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

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

The number of polymerizable functional groups per molecule of the charge transporting polymer is the amount of the polymerizable functional group used to synthesize the charge transporting polymer (for example, the amount of the monomer having a polymerizable functional group), each structure The average value can be obtained by using the monomer charge corresponding to the unit and the weight average molecular weight of the charge transporting polymer. The number of polymerizable functional groups is the ratio between the integral value of the signal derived from the polymerizable functional group and the integral value of the entire spectrum in the ¹ H NMR (nuclear magnetic resonance) spectrum of the charge transporting polymer, the charge transporting polymer The weight average molecular weight can be used to calculate the average value. Since it is simple, when the preparation amount is clear, a value obtained by using the preparation amount is preferably adopted.

  As mentioned above, although each structural unit was demonstrated, in this invention, a charge transport polymer contains the structure (I) in a molecule | numerator, It is characterized by the above-mentioned. When the charge transporting polymer contains the structure (I), it is easy to obtain a wide band gap. Therefore, it is possible to improve the light emission efficiency of the organic EL element or the like by using the charge transporting polymer containing the structure (I) in the molecule.

  The ratio of the structure (I) contained in one molecule of the charge transporting polymer is not particularly limited. The ratio of the structure (I) can be adjusted by, for example, the amount of the monomer capable of deriving the structural unit L1 or B1 including the structure (I). Or it can also adjust with the preparation amount of the monomer which can derive | lead-out the structural unit L2 or B2 which has a structure which can form a structure (I). In one embodiment, from the viewpoint of widening the band gap, the ratio of the total of the structural units L1, L2, B1, and B2 is preferably 10 mol% or more, more preferably 20 mol% or more, based on all structural units. 30 mol% or more is more preferable. On the other hand, from the viewpoint of charge transportability, the ratio of the total of the structural units L1, L2, B1, and B2 is preferably 90 mol% or less, more preferably 80 mol% or less, and 70 mol based on all structural units. % Or less is more preferable. When the structural unit T includes the structure (I) or has a structure capable of forming the structure (I), the above ratio includes the structural unit T.

  The charge-transporting polymer preferably includes a trivalent or higher valent structural unit B, and has a structure branched in three or more directions with this structural unit as a branching portion. When the charge transporting polymer has a branched structure, the viscosity of the polymer solution hardly changes with respect to the change in the molecular weight, which is preferable in terms of easy adjustment of the molecular weight. Moreover, it is preferable also from the point that it is easy to improve the durability of an organic electronics element.

  In the first embodiment, the charge transporting polymer includes a divalent structural unit L, a trivalent or higher structural unit B, and a monovalent structural unit T, and at least one of the structural units L, B, and T. One has the structure (I) in the structural unit. The charge transporting polymer preferably has (I) in at least one of the structural units L and B. That is, the charge transporting polymer preferably includes at least one of the structural unit L1 and the structural unit B1.

  In the second embodiment, the charge transporting polymer has the structure (I) in the partial structure formed by the combination of the structural units L, B and T. More preferably, the charge transporting polymer has a structure (I) in a partial structure formed by a bond between a divalent structural unit L and a trivalent or higher structural unit B. In such an embodiment, the charge transporting polymer includes a structure selected from substituted or unsubstituted aromatic amine structures, carbazole structures, benzene structures, and structures containing one or more of these structures. It is preferable to have a combination of a divalent structural unit L and a trivalent or higher structural unit B, and to include at least one of the structural unit L2 and the structural unit B2 in the above combination.

  A specific example of such a second embodiment is a divalent structural unit L2 having a substituted or unsubstituted aromatic amine structure in the combination of the divalent structural unit L and the trivalent or higher structural unit B. And a combination of a trivalent or higher structural unit B2 having a substituted or unsubstituted aromatic amine structure. More specifically, the divalent structural unit L2 and the trivalent or higher structural unit B2 may each have a triphenylamine structure. In this case, the charge transporting polymer includes the following partial structure (I-2) formed by the bond between the structural unit L2 and the structural unit B2, and has the structure (I) in the partial structure.

In the formula, R is the same as R ^{1 to} R ⁴ described in the structure (I). That is, each R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R is an alkyl group having 1 to 4 carbon atoms. The alkyl group may be linear or branched. In one embodiment, at least one of R is preferably a linear alkyl group, more preferably a methyl group.
R ′ is the same as R ′ of the structural unit L2 described above. In one embodiment, R ′ is a hydrogen atom or a linear alkyl having 1 to 8 carbon atoms. The alkyl group is preferably a linear alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

Another specific example of the second embodiment is a divalent structural unit L2 having a substituted or unsubstituted aromatic amine structure in the combination of the divalent structural unit L and the trivalent or higher structural unit B. And any one of trivalent or higher structural units B2.
An example of the combination is a combination of the divalent structural unit L3 and the trivalent or higher structural unit B2. In this case, the charge transporting polymer includes, for example, a partial structure (I-3) shown below formed by a bond between the structural unit L3 and the structural unit B2, and has the structure (I) in the partial structure.

In the formula, R is an alkyl group having 1 to 4 carbon atoms, and the alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable.
R ′ is the same as R ′ in the structural unit L2. In one embodiment, R ′ is the same as R ′ of the structural unit L2 described above. In one embodiment, R ′ is a hydrogen atom or a linear alkyl having 1 to 8 carbon atoms. The alkyl group is preferably a linear alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

Another example of the combination is a combination of the divalent structural unit L2 and the trivalent or higher structural unit B3. In this case, the charge transporting polymer has, for example, a partial structure (I-4) shown below formed by a bond between the structural unit L2 and the structural unit B3, and has the structure (I) in the partial structure. .

In the formula, R is an alkyl group having 1 to 4 carbon atoms, and the alkyl group may be linear or branched. A linear alkyl group is preferable, and a methyl group is more preferable.
R ′ is the same as R ′ in the structural unit L2. This is the same as R ′ of the structural unit L2 described above. In one embodiment, R ′ is a hydrogen atom or a linear alkyl having 1 to 8 carbon atoms. The alkyl group is preferably a linear alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

(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 formability, and the like. The number average molecular weight is preferably 500 or more, more preferably 1,000 or more, and still more preferably 2,000 or more, from the viewpoint of excellent charge transportability. In one embodiment, the number average molecular weight is preferably 3000 or more. The number average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, and more preferably 50,000 from the viewpoint of maintaining good solubility in a solvent and facilitating the preparation of an ink composition. The following is more preferable.

(Weight average molecular weight)
The weight average molecular weight of the charge transporting polymer can be appropriately adjusted in consideration of solubility in a solvent, film formability, and the like. The weight average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, and still more preferably 10,000 or more, from the viewpoint of excellent charge transportability. In one embodiment, the weight average molecular weight is preferably 20,000 or more. Further, the weight average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, and more preferably 400,000 from the viewpoint of maintaining good solubility in a solvent and facilitating preparation of an ink composition. The following is more preferable.

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

(Percentage of structural units)
The proportion of the structural unit L contained in the charge transporting polymer is preferably 10 mol% or more, more preferably 20 mol% or more, and more preferably 30 mol% or more based on the total structural unit from the viewpoint of obtaining sufficient charge transportability. Is more preferable. Further, the ratio of the structural unit L is preferably 95 mol% or less, more preferably 90 mol% or less, and still more preferably 85 mol% or less in consideration of the structural unit T and the structural unit B introduced as necessary. Here, the ratio of the structural unit L means the total of the structural units L including the structural units L1, L2, and L3.

  The proportion of the structural unit T contained in the charge transporting polymer is based on the total structural unit from the viewpoint of improving the characteristics of the organic electronics element or suppressing the increase in the viscosity and satisfactorily synthesizing the charge transporting polymer. 5 mol% or more is preferable, 10 mol% or more is more preferable, and 15 mol% or more is still more preferable. The proportion of the structural unit T is preferably 60 mol% or less, more preferably 55 mol% or less, and still more preferably 50 mol% or less from the viewpoint of obtaining sufficient charge transport properties.

  When the charge transporting polymer contains the structural unit B, the proportion of the structural unit B is preferably 1 mol% or more, more preferably 5 mol% or more, based on the total structural units, from the viewpoint of improving the durability of the organic electronics element. 10 mol% or more is more preferable. The proportion of the structural unit B is preferably 50 mol% or less, preferably 40 mol% or less, from the viewpoint of suppressing the increase in viscosity and satisfactorily synthesizing the charge transporting polymer or obtaining sufficient charge transportability. Is more preferable, and 30 mol% or less is still more preferable. Here, the ratio of the structural unit B means the total of the structural units B including the structural units B1, B2, and B3.

  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 the total structural unit from the viewpoint of efficiently curing the charge transporting polymer, 1 mol% or more is more preferable, and 3 mol% or more is still more preferable. The proportion of the polymerizable functional group is preferably 70 mol% or less, more preferably 60 mol% or less, and still more preferably 50 mol% or less from the viewpoint of obtaining good charge transportability. The “ratio of polymerizable functional groups” here refers to the ratio of structural units having a polymerizable functional group.

  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 to 70, more preferably 100: 3 to 50. Preferably, 100: 5-30 is more preferable. When the charge transporting polymer includes the structural unit B, the ratio (molar ratio) of the structural unit L, the structural unit T, and the structural unit B is L: T: B = 100: 10 to 200: 10 to 100. Preferably, 100: 20-180: 20-90 are more preferable, and 100: 40-160: 30-80 are still more preferable. Here, the ratio of the structural unit L means the total of the structural units L including the structural units L1, L2, and L3. The proportion of the structural unit B means the total of the structural units B including the structural units B1, B2, and B3.

The proportion of the structural unit can be determined by using the charged amount of the monomer corresponding to each structural unit used for synthesizing the charge transporting polymer. Moreover, the ratio of the structural unit can be calculated as an average value using an integrated value of the spectrum derived from each structural unit in the ¹ H NMR spectrum of the charge transporting polymer. Since it is simple, when the preparation amount is clear, a value obtained by using the preparation amount is preferably adopted.

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

  In the coupling reaction, for example, a Pd (0) compound, a Pd (II) compound, a Ni compound, or the like is used as a catalyst. In addition, a catalyst species generated by mixing tris (dibenzylideneacetone) dipalladium (0), palladium (II) acetate and the like with a phosphine ligand can also be used. For the method for synthesizing the charge transporting polymer, for example, the description of International Publication No. WO2010 / 140553 can be referred to.

Examples of monomer combinations that can be used in the Suzuki coupling reaction include the following.

  Each of the monomers L, B, and T is a monomer that can derive the structural units L, B, and T described above. In the monomer L, R ′ may be the same as R described in the structural unit L. In one Embodiment, R 'is a hydrogen atom or a C1-C8 alkyl group. The alkyl group may be a linear or branched alkyl group, more preferably a linear alkyl group. In the monomer B, each R is independently hydrogen or an alkyl group having 1 to 4 carbon atoms, and at least one of R is an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms is preferably a linear alkyl group, and more preferably a methyl group.

  According to the combination of the monomers, a polymer in which structural units L, B, and T derived from each monomer are bonded to each other is obtained by a reaction between a boronic acid group and a bromo group in the monomer. According to the exemplified combination of monomers, the structure (I) is formed in the partial structure formed by combining the structural unit L and the structural unit B. Each monomer may have a combination of reactive functional groups that can form a bond by reaction with each other, and may have a structure in which a boronic acid group and a bromo group are interchanged with each other. , A boronic acid ester, or a halogen group other than a bromo group.

[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 be added to the organic electronic material to develop a doping effect and improve the charge transport property. Doping includes p-type doping and n-type doping. In p-type doping, a substance serving as an electron acceptor is used as a dopant, and in n-type doping, a substance serving as an electron donor is used as a dopant. It is preferable to perform p-type doping for improving hole transportability and n-type doping for improving electron transportability. The dopant used in the organic electronic material may be a dopant that exhibits any effect of p-type doping or n-type doping. Further, one kind of dopant may be added alone, or plural kinds of dopants may be mixed and added.

The dopant used for p-type doping is an electron-accepting compound, and examples thereof include Lewis acids, proton acids, transition metal compounds, ionic compounds, halogen compounds, and π-conjugated compounds. Specifically, as the Lewis acid, FeCl ₃ , PF ₅ , AsF ₅ , SbF ₅ , BF ₅ , BCl ₃ , BBr _{3 and the} like; as the protonic acid, HF, HCl, HBr, HNO ₅ , H ₂ SO ₄ , HClO _{4 and} other inorganic acids, benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, polyvinylsulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, 1-butanesulfonic acid, vinylphenylsulfonic acid Organic acids such as camphorsulfonic acid; transition metal compounds include FeOCl, TiCl ₄ , ZrCl ₄ , HfCl ₄ , NbF ₅ , AlCl ₃ , NbCl ₅ , TaCl ₅ , MoF ₅ ; Phenyl) borate ion, tris (trifluoro) Methanesulfonyl) Mechidoion, bis (trifluoromethanesulfonyl) imide ion, hexafluoroantimonate ion, AsF ₆ ^- (hexafluoro arsenic acid ions), BF ₄ ^- (tetrafluoroborate), PF ₆ ^- (hexafluorophosphate) salts having a perfluoroalkyl anions etc., a salt with a conjugate base of the protonic acid as an anion. Examples of the halogen _{compound, Cl 2, Br 2, I} 2, ICl, ICl 3, IBr, IF and the like; [pi conjugated compound Examples thereof include TCNE (tetracyanoethylene), TCNQ (tetracyanoquinodimethane) and the like. Moreover, it is also possible to use the electron-accepting compounds described in JP 2000-36390 A, JP 2005-75948 A, JP 2003-213002 A, and the like. Preferred are Lewis acids, ionic compounds, π-conjugated compounds and the like.

The dopant used for n-type doping is an electron donating compound, for example, alkali metals such as Li and Cs; alkaline earth metals such as Mg and Ca; alkali metals such as LiF and Cs ₂ CO ₃ and / or Examples include alkaline earth metal salts; metal complexes; electron-donating organic compounds.

  When the charge transporting polymer has a polymerizable functional group, it is preferable to use a compound that can act as a polymerization initiator for the polymerizable functional group as a dopant in order to facilitate the change in solubility of the organic layer.

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

[Content]
The content of the charge transporting polymer is preferably 50% by weight or more, more preferably 70% by weight or more, and further preferably 80% by weight or more based on the total weight of the organic electronic material from the viewpoint of obtaining good charge transporting properties. preferable. It may be 100% by mass.

  When the dopant is contained, the content is preferably 0.01% by mass or more, and 0.1% by mass or more with respect to the total mass of the organic electronic material from the viewpoint of improving the charge transport property of the organic electronic material. More preferred is 0.5% by mass or more. Moreover, from a viewpoint of maintaining favorable film formability, 50 mass% or less is preferable with respect to the total mass of the organic electronic material, 30 mass% or less is more preferable, and 20 mass% or less is still more preferable.

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

[solvent]
As the solvent, water, an organic solvent, or a mixed solvent thereof can be used. 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, phenetole, 2-methoxytoluene, 3-methoxytoluene, Aromatic ethers such as 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole; ethyl acetate, n-butyl acetate, ethyl lactate, n-butyl lactate Aliphatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate; N, N-dimethylformamide, N, N-dimethylacetamide, etc. Amide solvents; dimethyl sulfoxide, tetrahydrofuran, acetone, chloroform, methylene chloride and the like can be mentioned. Preferred are aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers and the like.

[Polymerization initiator]
When the charge transporting polymer has a polymerizable functional group, the ink composition preferably contains a polymerization initiator. As the polymerization initiator, known radical polymerization initiators, cationic polymerization initiators, anionic polymerization initiators and the like can be used. From the viewpoint of easily preparing the ink composition, it is preferable to use a substance having both a function as a dopant and a function as a polymerization initiator. As such a substance, the said ionic compound is mentioned, for example.

[Additive]
The ink composition may further contain an additive as an optional component. Examples of additives include polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, antioxidants, oxidizing agents, reducing agents, surface modifiers, emulsifiers, antifoaming agents, Examples thereof include a dispersant and a surfactant.

[Content]
The content of the solvent in the ink composition can be determined in consideration of 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 0.5% by mass or more. More preferred is an amount of The content of the solvent is preferably 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, and even more preferably 10% by mass or less. .

<Organic layer>
The organic layer which is embodiment of this invention is a layer formed using the organic electronics material or ink composition of the said embodiment. By using the ink composition, the organic layer can be favorably formed by a coating method. Examples of the coating method include spin coating method; casting method; dipping method; letterpress printing, intaglio printing, offset printing, planographic printing, letterpress inversion offset printing, screen printing, gravure printing and other plate printing methods; ink jet method, etc. A known method such as a plateless printing method may be used. When the organic layer is formed by a coating method, the organic layer (coating layer) obtained after the coating may be dried using a hot plate or an oven to remove the solvent.

  When the charge transporting polymer has a polymerizable functional group, the solubility of the organic layer can be changed by advancing the polymerization reaction of the charge transporting polymer by light irradiation, heat treatment or the like. By laminating organic layers with different solubility, it is possible to easily increase the number of organic electronics elements. For the method of forming the organic layer, for example, the description of International Publication No. WO2010 / 140553 can be referred to.

  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 further preferably 3 nm or more. In addition, the thickness of the organic layer is preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 100 nm or less, from the viewpoint of reducing electrical resistance.

<Organic electronics elements>
The organic electronics element which is embodiment of this invention has the organic layer of the said embodiment at least. Examples of the organic electronics element include an organic EL element, an organic photoelectric conversion element, and an organic transistor. The organic electronic element preferably has a structure in which an organic layer is disposed between at least a pair of electrodes including an anode and a cathode.

[Organic EL device]
The organic EL element which is embodiment of this invention has an organic layer of the said embodiment at least. In one embodiment, the organic EL element has a substrate and the organic layer of the above embodiment. The organic EL element usually includes a light emitting layer, an anode, a cathode, and a substrate, and other functional layers such as a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer are provided as necessary. I have. Each layer may be formed by a vapor 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 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 an embodiment of an organic EL element. The organic EL element of FIG. 1 is an element having a multilayer structure, and includes 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, The electron injection layer 5 and the cathode 4 are provided in this order. Hereinafter, each layer will be described.

[Light emitting layer]
As a material used for the light emitting layer, a light emitting material such as a low molecular compound, a polymer, or a dendrimer can be used. A polymer is preferable because it has high solubility in a solvent and is suitable for a coating method. Examples of the light emitting material include a fluorescent material, a phosphorescent material, a thermally activated delayed fluorescent material (TADF), and the like.

  Low molecular weight compounds such as perylene, coumarin, rubrene, quinacdrine, stilbene, dye laser dyes, aluminum complexes, and derivatives thereof; polyfluorene, polyphenylene, polyphenylene vinylene, polyvinyl carbazole, fluorene-benzothiadiazole copolymer , Fluorene-triphenylamine copolymers, polymers thereof such as derivatives thereof; mixtures thereof and the like.

As the phosphorescent material, a metal complex containing a metal such as Ir or Pt can be used. Examples of the Ir complex include FIr (pic) that emits blue light (iridium (III) bis [(4,6-difluorophenyl) -pyridinate-N, C ² ] picolinate), Ir (ppy) ₃ that emits green light. (Factris (2-phenylpyridine) iridium), which emits red light (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-formin platinum) that emits red light.

  When the light emitting layer includes a phosphorescent material, it is preferable that a host material is further included in addition to the phosphorescent material. As the host material, a low molecular compound, a polymer, or a dendrimer can be used. 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), derivatives thereof, and the like include polymers of the organic electronic materials, polyvinyl carbazole, polyphenylene, polyfluorene, derivatives thereof, and the like of the above embodiment. It is done.

  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) 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, thiopyran dioxide derivatives, condensed ring tetracarboxylic anhydrides such as naphthalene and perylene, and carbodiimides. Fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, thiadiazole derivatives, benzimidazole derivatives, quinoxaline derivatives, aluminum complexes, and the like. Moreover, the organic electronic material of the said embodiment can also be used.

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

[anode]
As the anode material, for example, a metal (for example, Au) or another material having conductivity is used. Examples of other materials include oxides (for example, ITO: indium oxide / tin oxide) and conductive polymers (for example, polythiophene-polystyrene sulfonic acid mixture (PEDOT: PSS)).

[substrate]
As the substrate, glass, plastic or the like can be used. The substrate is preferably transparent and preferably has flexibility. Quartz glass, light transmissive resin film, and the like are preferably used.

  Examples of the resin film include polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, and cellulose acetate propionate. Can be mentioned.

  When using a resin film, in order to suppress permeation | transmission of water vapor | steam, oxygen, etc., you may coat and use inorganic substances, such as a silicon oxide and a silicon nitride, on a resin film.

[Luminescent color]
The emission color of the organic EL element is not particularly limited. The white organic EL element is preferable because it can be used for various lighting devices such as home lighting, interior lighting, a clock, or a liquid crystal backlight.

  As a method of forming a white organic EL element, a method of simultaneously emitting light of a plurality of emission colors using a plurality of light emitting materials and mixing the colors can be used. A combination of a plurality of emission colors is not particularly limited, but a combination containing three emission maximum wavelengths of blue, green and red, a combination containing two emission maximum wavelengths of blue and yellow, yellow green and orange, etc. Is mentioned. The emission color can be controlled by adjusting the type and amount of the light emitting material.

<Display element, lighting device, display device>
The display element which is embodiment of this invention is equipped with the organic EL element of the said embodiment. For example, a color display element can be obtained by using an organic EL element as an element corresponding to each pixel of red, green, and blue (RGB). 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.

  Moreover, the illuminating device which is embodiment of this invention is equipped with the organic EL element of embodiment of this invention. Furthermore, the display apparatus which is embodiment of this invention is equipped with the illuminating device and the liquid crystal element as a display means. For example, the display device may be a display device using a known liquid crystal element as a display unit, that is, a liquid crystal display device, using the illumination device according to the embodiment of the present invention as a backlight.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to the following embodiment.

I. Preparation of charge transporting polymer (Preparation of Pd catalyst)
The catalyst used in preparing the charge transporting polymer was prepared as follows.
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, anisole (15 ml) was added, and the mixture was stirred for 30 minutes. Similarly, tris (t-butyl) phosphine (129.6 mg, 640 μmol) was weighed in a sample tube, anisole (5 ml) was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at room temperature for 30 minutes, and the resulting product was used as a catalyst.

(Preparation Example 1) Charge transporting polymer 1
In a three-necked round bottom flask, monomer 1 (5.0 mmol), monomer 2 (2.0 mmol), monomer 3 (4.0 mmol) and anisole (20 ml) shown below were placed, and the Pd catalyst prepared earlier was further added. Solution (7.5 ml) was added. After stirring these raw materials for 30 minutes, a 10% tetraethylammonium hydroxide aqueous solution (20 ml) was added. In addition, all the solvents used for reaction were used after deaerating for 30 minutes or more with a nitrogen bubble. The reaction mixture was heated and refluxed for 2 hours. All operations so far were performed under a nitrogen stream.

  After completion of the reaction, the organic layer was washed with water, and the organic layer was poured into methanol-water (9: 1). The resulting precipitate was suction filtered and washed with methanol-water (9: 1). The resulting precipitate was dissolved in toluene and reprecipitated from methanol. The obtained precipitate was suction filtered, dissolved in toluene, triphenylphosphine, polymer-bound on styrene-divine benzene copolymer (200 mg from 100 mg of polymer, polymer), and stirred overnight. After completion of the stirring, triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer and insoluble matter were removed by filtration, and the filtrate was concentrated by a rotary evaporator. The residue was dissolved in toluene and then reprecipitated from methanol-acetone (8: 3). The resulting precipitate was filtered by suction and washed with methanol-acetone (8: 3). The obtained precipitate was vacuum-dried to obtain 1.3 g of charge transporting polymer 1.

  The number average molecular weight of the obtained charge transporting polymer 1 was 5800, and the mass average molecular weight was 39700. The charge transporting polymer 1 has a structural unit L (derived from the monomer 1), a structural unit B2 (derived from the monomer 2), and a structural unit T (derived from the monomer 3). 5%, 18.2%, and 36.4%.

The number average molecular weight and the weight average molecular weight were measured by GPC (polyethylene conversion) using tetrahydrofuran (THF) as an eluent. The measurement conditions are as follows.
Liquid feed pump: L-6050 Hitachi High-Technologies UV-Vis detector: L-3000 Hitachi High-Technologies columns: Gelpack (registered trademark) GL-A160S / GL-A150S Hitachi Chemical Co., Ltd.
Eluent: THF (for HPLC, without stabilizer) Wako Pure Chemical Industries, Ltd.
Flow rate: 1 mL / min
Column temperature: Room temperature Molecular weight Standard: Standard polystyrene

(Preparation Example 2) Charge transporting polymer 2
A charge transporting polymer 2 was prepared in the same manner as in Preparation Example 1 except that the monomer 2 in Preparation Example 1 was changed to the monomer 4 shown below. The number average molecular weight of the obtained charge transporting polymer 2 was 3500, and the mass average molecular weight was 27300. The charge transporting polymer 2 has a structural unit L (derived from the monomer 1), a structural unit B2 (derived from the monomer 4), and a structural unit T (derived from the monomer 3). 5%, 18.2%, and 36.4%.

(Preparation Example 3) Charge transporting polymer 3
A charge transporting polymer 3 was prepared in the same manner as in Preparation Example 1 except that the monomer 2 in Preparation Example 1 was changed to the monomer 5 shown below.
The number average molecular weight of the obtained charge transporting polymer 3 was 7800, and the mass average molecular weight was 31000. The charge transporting polymer 3 has a structural unit L (derived from the monomer 1), a structural unit B (derived from the monomer 5), and a structural unit T (derived from the monomer 3). 5%, 18.2%, and 36.4%.

II. Evaluation of Organic Electronics Materials The charge transporting polymers 1 to 3 prepared above were used as organic electronics materials, and various characteristics were examined.

<Organic EL device>
In Examples 1 and 2 and Comparative Example 1 below, an organic EL element having a hole transport layer constituted by using the charge transport polymers 1 to 3 prepared previously was examined.
Example 1
An ink composition for a hole injection layer, comprising charge transporting polymer 3 (10.0 mg), compound 1 (0.5 mg) represented by the following formula as a polymerization initiator, and toluene (2.3 mL) was prepared. did. In a nitrogen atmosphere, the ink composition prepared above was spin-coated at 3000 min ⁻¹ on a glass substrate patterned with ITO to a width of 1.6 mm, and then heated on a hot plate at 220 ° C. for 10 minutes. Was cured to form a hole injection layer (30 nm).

Next, an ink composition for a hole transport layer composed of charge transporting polymer 1 (20 mg) and toluene (2.3 mL) was prepared. The obtained ink composition was spin-coated on the previously formed hole injection layer at 3000 min ⁻¹ , then heated on a hot plate at 180 ° C. for 10 minutes, and the coating film was dried. A transport layer (40 nm) was formed. Thereby, a laminate of glass substrate / hole injection layer / hole transport layer was obtained.

Next, the laminate obtained as described above was transferred during vacuum deposition, and CBP: Ir (ppy) ₃ (94: 6, ₃₀ nm), BAlq (10 nm), Alq ₃ was formed on the hole transport layer. (30 nm), LiF (0.8 nm), Al (100 nm) were formed in this order by a vapor deposition method, and sealing treatment was performed to produce an organic EL element.
The luminous efficiency of the obtained organic EL element was evaluated using a luminance meter (Topcon, BM7) and a current voltmeter (YOKOGAWA / HEWLETT / PACKARD 4140B). Specifically, the light emission efficiency was measured when the light emission luminance was set to 3000 cd / m ² . The results are shown in Table 1.

(Example 2)
An organic EL device was produced in the same manner as in Example 1 except that the charge transporting polymer 1 in the ink composition was changed to the charge transporting polymer 2 in the hole transport layer forming step. The luminous efficiency of the obtained organic EL device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
An organic EL device was produced in the same manner as in Example 1 except that the charge transporting polymer 1 in the ink composition was changed to the charge transporting polymer 3 in the hole transport layer forming step. The luminous efficiency of the obtained organic EL device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

  From comparison between Examples 1 and 2 and Comparative Example 1, it can be seen that an improvement in luminous efficiency can be achieved by constituting an organic EL device using a charge transporting polymer having a specific structure in the molecule. More specifically, the charge transporting polymers 1 and 2 used in Examples 1 and 2 have a substituent at a specific position of the benzene ring in the polymer molecule. In contrast, the charge transporting polymer 3 used in Comparative Example 1 does not have a substituent at a specific position of the benzene ring in the polymer molecule.

Table 2 shows the results of measuring the UV spectra of the charge transporting polymers 1 to 3 respectively. As can be seen from Table 2, the charge transporting polymers 1 and 2 have a substituent introduced based on the absorption edge of the charge transporting polymer 3 having no substituent at a specific position of the benzene ring in the polymer molecule. The absorption edge is shifted. From this, it can be seen that the conjugated structure is twisted. It can also be seen that such a twisted structure widens the band gap.

<Evaluation of solvent resistance>
First, using the layered structure of the hole injection layer / hole transport layer as a model, an embodiment in which the hole transport layer was formed using the charge transport polymers 1 to 3 previously prepared was studied. More specifically, in Examples 3 to 6 below, the resistance of a laminate obtained by forming a film of the ink composition containing the charge transporting polymers 1 to 3 on the hole injection layer according to a coating method. The solvent property was evaluated.

(Example 3)
Ink composition 1 comprising charge-transporting polymer 3 (10.0 mg), compound 1 (0.5 mg) represented by the following formula as a polymerization initiator, and toluene (2.3 mL) was prepared. This ink composition 1 was spin-coated on a quartz plate at 3000 rpm. Next, the coating film was dried on a hot plate at 180 ° C. for 10 minutes to form a first thin film on the quartz plate.

  Next, an ink composition 2 composed of charge transporting polymer 1 (10.0 mg) and toluene (2.3 mL) was prepared. This ink composition 2 was spin-coated on the first thin film at 3000 rpm. Next, the second thin film was formed by heating at 180 ° C. for 10 minutes on a hot plate, and a laminate of quartz plate / first thin film / second thin film was obtained. The obtained laminate was immersed in toluene for 1 minute and washed. The residual film ratio was measured from the ratio of absorbance (Abs) of the absorption maximum (λmax) in the UV-vis spectrum of the laminate before and after washing. The results are shown in Table 3.

Example 4
Except that the second thin film was formed using the ink composition obtained by changing the charge transporting polymer 1 to the charge transporting polymer 2 for the ink composition 2 of Example 3, the same as in Example 3, A laminate was obtained. About the obtained laminated body, it carried out similarly to Example 3, and measured the remaining film rate. The results are shown in Table 3.

(Example 5)
The ink composition 2 of Example 3 was changed to an ink composition comprising the charge transporting polymer 1 (10.0 mg), the compound 1 (0.5 mg) as a polymerization initiator, and toluene (2.3 mL). Then, a laminate was obtained in the same manner as in Example 3 except that the second thin film was formed. About the obtained laminated body, it carried out similarly to Example 3, and measured the remaining film rate. The results are shown in Table 3.

(Example 6)
The ink composition 2 of Example 3 was changed to an ink composition comprising the charge transporting polymer 2 (10.0 mg), the compound 1 (0.5 mg) as a polymerization initiator, and toluene (2.3 mL). A laminate was obtained in the same manner as in Example 3 except that the second thin film was formed. Moreover, about the obtained laminated body, it carried out similarly to Example 3, and measured the remaining film rate. The results are shown in Table 3.

  As apparent from Examples 3 to 6, the charge transporting polymer has a polymerizable functional group in the molecule, so that the hole transporting layer is insolubilized and a high remaining film ratio can be achieved. From this, it is understood that when a charge transporting polymer having a polymerizable functional group in the molecule is used, it becomes easier to form an organic layer by a wet process, and further, lamination by a coating method is possible on the upper layer. .

DESCRIPTION OF SYMBOLS 1 Light emitting layer 2 Anode 3 Hole injection layer 4 Cathode 5 Electron injection layer 6 Hole transport layer 7 Electron transport layer

Claims (16)

An organic electronic material comprising a charge transporting polymer having a structure (I) represented by the following formula in a molecule.

[Wherein, R ^{1 to} R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{1 to} R ⁴ is an alkyl group having 1 to 4 carbon atoms. is there. ] The organic electronics material according to claim 1, wherein the structure (I) includes a substituted biphenylene structure (I-1) represented by the following formula.

[Wherein, R ^{1 to} R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{1 to} R ⁴ is an alkyl group having 1 to 4 carbon atoms. is there. ]   The organic electronic material according to claim 1 or 2, wherein the charge transporting polymer includes a divalent structural unit having charge transporting properties and a trivalent or higher structural unit having charge transporting properties.   The organic electronic material according to claim 3, wherein at least one of the divalent structural unit and the trivalent or higher structural unit includes the structure (I).   The organic electronic material according to claim 3, wherein a partial structure formed by bonding the divalent structural unit and the trivalent or higher structural unit includes the structure (I).   At least one of the divalent structural unit and the trivalent or higher structural unit is a substituted or unsubstituted aromatic amine structure, carbazole structure, and benzene structure, and a structure containing one or more of these. 6. The organic electronic material according to any one of claims 3 to 5, comprising a selected structure.   The organic electronic material according to claim 3, wherein the divalent structural unit and the trivalent or higher structural unit each include a substituted or unsubstituted aromatic amine structure.   The organic electronic material according to any one of claims 1 to 7, wherein the charge transporting polymer further has one or more polymerizable functional groups in a molecule.   An ink composition comprising the organic electronic material according to claim 1 and a solvent.   The ink composition according to claim 9, further comprising a polymerization initiator.   The organic electronics element containing a board | substrate and the organic layer formed using the ink composition of Claim 9 or 10.   The organic electronics element according to claim 11, wherein the substrate is a resin film.   The organic electroluminescent element which has an organic layer formed using the ink composition of Claim 9 or 10.   The organic electroluminescent element according to claim 13, wherein the organic layer is a hole injection layer.   The organic electroluminescent element according to claim 13, wherein the organic layer is a hole transport layer.   The organic electroluminescent element according to any one of claims 13 to 15, further comprising a pair of electrodes composed of an anode and a cathode, wherein the organic layer is disposed between the pair of electrodes.

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