JP2020145236A - Organic electronics material and use thereof - Google Patents

Abstract

To provide an organic electronics material suitable for a wet process and improving life characteristics of an organic electronics element, provide an organic layer suitable for improving life characteristics of the organic electronics element, and further provide the organic electronic element with excellent life characteristics, the organic EL element, a display element, a lighting device, and a display device.SOLUTION: An organic electronics material contains a charge-transporting polymer or oligomer having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms.SELECTED DRAWING: None

Description

Embodiments of the present invention relate to organic electronics materials, ink compositions, organic layers, organic electronics devices, organic electroluminescence devices (also referred to as "organic EL devices"), display devices, lighting devices, and display devices.

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

The organic EL element is roughly classified into two types, a low molecular weight organic EL element using a low molecular weight compound and a high molecular weight organic EL element using a high molecular weight compound, depending on the organic material used. The method for manufacturing an organic EL element is a dry process in which film formation is mainly performed in a vacuum system, and a wet process in which film formation is performed by plate printing such as letterpress printing or intaglio printing, or plateless printing such as inkjet. It is roughly divided into two. The wet process is expected as an indispensable method for future large-screen organic EL displays because simple film formation is possible (see, for example, Patent Document 1 and Non-Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-279007

Kengo Hirose, Daisuke Kumaki, Nobuaki Koike, Akira Kuriyama, Seiichiro Ikehata, Shizushi Tokito, 53rd Joint Lecture on Applied Physics, 26p-ZK-4 (2006)

The organic EL device manufactured by using the wet process has the features that the cost can be reduced and the area can be easily increased. However, with respect to the characteristics of the organic EL element, further improvement is desired in the organic EL element manufactured by using the wet process.

In view of the above, it is an object of the present invention to provide an organic electronic material and an ink composition suitable for a wet process and for improving the life characteristics of an organic electronic device. Another embodiment of the present invention provides an organic layer suitable for improving the life characteristics of an organic electronic device, and further, an organic electronic device, an organic EL element, a display element, a lighting device, and an organic electronic device having excellent life characteristics. An object of the present invention is to provide a display device.

式中、Ａｒは置換又は非置換の芳香環を表す。Ｒ^１は、炭素数１０〜２４の直鎖のアルキル基を表す。＊は他の構造単位との結合部位を表す。
（５）前記電荷輸送性ポリマー又はオリゴマーが、置換又は非置換の、芳香族アミン構造、カルバゾール構造、チオフェン構造、フルオレン構造、ベンゼン構造、及び、ピロール構造からなる群から選択される少なくとも１種を含む２価の構造単位を有する、前記有機エレクトロニクス材料。
（６）前記電荷輸送性ポリマー又はオリゴマーが、３個以上の末端を有する、前記有機エレクトロニクス材料。
（７）前記電荷輸送性ポリマー又はオリゴマーが、前記炭素数１０〜２４の直鎖のアルキル基を有する芳香環を含む構造単位を、全末端数を基準として２５モル％以上の末端に有する、前記有機エレクトロニクス材料。
（８）前記電荷輸送性ポリマー又はオリゴマーが、正孔輸送性を有する構造単位を有するモノマーと、炭素数１０〜２４の直鎖のアルキル基を有する芳香環を含む構造単位を有するモノマーとを少なくとも含むモノマー混合物の共重合体である、前記有機エレクトロニクス材料。
（９）前記電荷輸送性ポリマー又はオリゴマーが、重合性官能基を更に有する、前記有機エレクトロニクス材料。
（１０）前記有機エレクトロニクス材料と、溶媒とを含む、インク組成物。
（１１）前記有機エレクトロニクス材料、又は前記インク組成物を用いて形成された、有機層。
（１２）前記有機層を少なくとも一つ備える、有機エレクトロニクス素子。
（１３）前記有機層を少なくとも一つ備える、有機エレクトロルミネセンス素子。
（１４）フレキシブル基板を更に備える、前記有機エレクトロルミネセンス素子。
（１５）樹脂フィルム基板を更に備える、前記有機エレクトロルミネセンス素子。
（１６）前記有機エレクトロルミネセンス素子を備えた、表示素子。
（１７）前記有機エレクトロルミネセンス素子を備えた、照明装置。
（１８）前記照明装置と、表示手段として液晶素子とを備えた、表示装置。 Embodiments of the present invention relate to the following.
(1) An organic electronics material containing a charge-transporting polymer or oligomer having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms.
(2) The organic electronic material in which the aromatic ring contains an aromatic hydrocarbon.
(3) The organic electronics material, wherein the charge-transporting polymer or oligomer has at least one terminal structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms.
(4) The organic electronics material in which the charge-transporting polymer or oligomer has a structural unit represented by the following general formula.

In the formula, Ar represents a substituted or unsubstituted aromatic ring. R ¹ represents a linear alkyl group having 10 to 24 carbon atoms. * Represents a binding site with another structural unit.
(5) At least one selected from the group consisting of an aromatic amine structure, a carbazole structure, a thiophene structure, a fluorene structure, a benzene structure, and a pyrrole structure in which the charge transport polymer or oligomer is substituted or unsubstituted. The organic electronic material having a divalent structural unit containing.
(6) The organic electronics material in which the charge-transporting polymer or oligomer has three or more ends.
(7) The charge-transporting polymer or oligomer has a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms at the terminal of 25 mol% or more based on the total number of terminals. Organic electronics materials.
(8) The charge-transporting polymer or oligomer contains at least a monomer having a structural unit having a hole-transporting property and a monomer having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms. The organic electronics material, which is a copolymer of a monomer mixture containing.
(9) The organic electronics material in which the charge-transporting polymer or oligomer further has a polymerizable functional group.
(10) An ink composition containing the organic electronic material and a solvent.
(11) An organic layer formed by using the organic electronic material or the ink composition.
(12) An organic electronic device including at least one of the organic layers.
(13) An organic electroluminescence device including at least one of the organic layers.
(14) The organic electroluminescence device further comprising a flexible substrate.
(15) The organic electroluminescence device further comprising a resin film substrate.
(16) A display element including the organic electroluminescence element.
(17) A lighting device provided with the organic electroluminescence element.
(18) A display device including the lighting device and a liquid crystal element as a display means.

The organic electronic material and ink composition according to the embodiment of the present invention are suitable for a wet process and are suitable for improving the life characteristics of an organic electronic device. Further, the organic layer according to the embodiment of the present invention is suitable for improving the life characteristics of the organic electronic device.
Further, the organic electronics element, the organic EL element, the display element, the lighting device, and the display device according to the embodiment of the present invention have excellent life characteristics.

It is sectional drawing which shows an example of the organic EL element which is an embodiment of this invention.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

<Organic electronics materials>
The organic electronic material of the present embodiment is characterized by containing a charge transport polymer or oligomer having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms. The organic electronics material may contain only one type of charge-transporting polymer or oligomer, or may contain two or more types. The charge-transporting polymer or oligomer is preferable in that it is superior in film-forming property in a wet process as compared with a low-molecular-weight compound.

[Charge transport polymer or oligomer]
A charge-transporting polymer or oligomer (in the following description, the charge-transporting polymer or oligomer is also collectively referred to as a "charge-transporting polymer") is a polymer or oligomer capable of transporting charges. The charge-transporting polymer may be linear or may have a branched structure. The charge-transporting polymer preferably has at least a divalent structural unit L having a charge-transporting property and a monovalent structural unit T constituting the terminal portion, and a trivalent or higher-valent structural unit B constituting the branch portion. May further have. The charge-transporting polymer may have only one type of each structural unit, or may have a plurality of types of each. In charge-transporting polymers, the structural units are attached to each other at "monovalent" to "trivalent or higher" binding sites.

As will be described later, the charge-transporting polymer of the present embodiment is characterized by having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms as a characteristic structure. For example, the charge-transporting polymer may have a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms at at least one end. That is, at least a part of the above-mentioned "monovalent structural unit T" may be a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms. Further, a linear chain having 10 to 24 carbon atoms is added to at least a part of the substituent of the above "divalent structural unit L" or at least a part of the substituent of the "trivalent or higher structural unit B" other than the polymer terminal. It may contain an aromatic ring having an alkyl group of.

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

Linear charge transport polymer

Charge-transporting polymer with branched structure

In the present embodiment, the charge-transporting polymer is a linear chain having 10 to 24 carbon atoms in at least a part of the structural unit T and the substituents of the structural unit L and the substituents of the structural unit B. It preferably contains an aromatic ring having an alkyl group.

(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 includes an atomic group capable of transporting electric charges. For example, the structural unit L is a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophenanthrene structure, fluorene structure, benzene structure, biphenylene structure, turphenylene structure, naphthalene structure, anthracene structure, tetracene structure, phenanthrene structure, dihydro. Phenanthrene structure, pyridine structure, pyrazine structure, quinoline structure, isoquinoline structure, quinoxalin structure, aclysine structure, diazaphenanthrene structure, furan structure, pyrrole structure, oxazole structure, oxaziazole structure, thiazole structure, thiazazole structure, triazole structure, benzo It contains at least one selected from the group consisting of a thiophene structure, a benzoxazole structure, a benzoxaziazole structure, a benzothiazole structure, a benzothiazazole structure, and a benzotriazole structure. The aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure. Further, the structural unit L may contain an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms.

In the present embodiment, the structural unit L is composed of a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, and pyrrole structure from the viewpoint of obtaining excellent hole transportability. It is preferable to contain at least one selected from the group, and more preferably to contain at least one selected from the group consisting of a substituted or unsubstituted aromatic amine structure and a carbazole structure. The structural unit L includes at least one selected from the group consisting of a substituted or unsubstituted fluorene structure, benzene structure, phenanthrene structure, pyridine structure, and quinoline structure from the viewpoint of obtaining excellent electron transportability. Is preferable.

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

R each independently represents a hydrogen atom or a substituent. It is preferable that at least one R is a hydrogen atom. When R is a substituent, the substituents are independently -R ¹ , -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ , halogen atom, respectively. It is preferable to select from the group consisting of groups containing polymerizable functional groups, which will be described later. R ^{1 to} R ⁸ each independently have a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 24 carbon atoms, an alkenyl group, and an alkynyl group, and an aryl having 2 to 30 carbon atoms. Represents a group or heteroaryl group. Aryl groups are atomic groups obtained by removing one hydrogen atom from aromatic hydrocarbons. 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 having 1 to 24 carbon atoms. May be substituted with an alkyl group or an alkoxy group. R is preferably a hydrogen atom or a group selected from the group consisting of an alkyl group, an aryl group, an alkyl-substituted aryl group, and an alkyl-substituted heteroaryl group. As the alkyl-substituted aryl group or alkyl-substituted heteroaryl group, for example, an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms is preferable. Ar represents an arylene group or a heteroarylene group having 2 to 30 carbon atoms. The 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.

(Structural unit T)
The structural unit T is a monovalent structural unit constituting the terminal portion of the charge-transporting polymer. As will be described later, when the charge-transporting polymer has a polymerizable functional group at the terminal portion, the structural unit T may have a polymerizable structure (that is, a polymerizable functional group such as a pyrrole-yl group). .. Further, the structural unit T may have the same structure as the structural unit L except for the valence, or may have a different structure. Further, the structural unit T may contain an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms.

(Structural unit T1)
In the present embodiment, at least a part of the structural unit T preferably has a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms, and the structural unit is referred to as "structural unit T1". Call it. The charge-transporting polymer may have only one type of structural unit T1 at at least one end, or may have two or more types. It is preferable that the charge transporting polymer has the structural unit T1 at the terminal because the hole transporting property is improved. It is considered that having a long-chain alkyl group allows polymer molecules to be aligned via the alkyl group, improving hole transportability, and as a result, exhibiting high performance as an organic electronics material.

In the structural unit T1, the structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms is preferably a structural unit as shown in the following formula.

In the above formula, Ar represents a substituted or unsubstituted aromatic ring. R ¹ represents a linear alkyl group having 10 to 24 carbon atoms. * Represents a binding site with another structural unit. Ar is preferably an aromatic hydrocarbon or an aromatic heterocycle. When Ar has a substituent, examples of the substituent include a substituent listed as R in the structural formula (1) described later. R ¹ is a linear alkyl group having 10 to 24 carbon atoms, preferably a linear alkyl group having 12 to 24 carbon atoms, and more preferably a linear alkyl group having 14 to 24 carbon atoms.

Further, in the structural unit T1, the structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms is particularly preferably a structural unit as shown in the following structural formula (1).

In the above structural formula, R ¹ represents a linear alkyl group having 10 to 24 carbon atoms, preferably a linear alkyl group having 12 to 24 carbon atoms, and more preferably a linear alkyl group having 14 to 24 carbon atoms. preferable. R represents a substituent, each of which has 1 to 22 carbon atoms, a linear, cyclic or branched alkyl group, an alkenyl group, an alkynyl group, and an alkoxy group, and 2 carbon atoms. It is preferably at least one selected from the group consisting of ~ 30 aryl groups and heteroaryl groups. The aryl group and the heteroaryl group may further have a substituent, and the substituent is preferably a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms. When the charge-transporting polymer has a polymerizable functional group at the terminal portion, at least one of R may be a group containing a polymerizable functional group. m represents an integer from 0 to 4. * Represents a binding site with another structural unit. In addition, m is preferably 0.

The replacement position of R ¹ may be any, but from the viewpoint of the effect of lowering the drive voltage, the para position, the meta position, or the ortho position may be based on * in the above structural formula (1). This order is preferable. It is also possible to include two or more benzene rings having different substitution positions of R ^{1 in} the charge transport polymer.

Preferred specific examples of the structural unit T1 are listed below. The structural unit T1 is not limited to the following. Further, it is preferable that m in the following structural formula is 0. In addition, R in the following structural formula represents a substituent, and each of the substituents independently includes the substituents listed as R in the above structural formula (1).

(Structural unit T2)
In the present embodiment, the charge transporting polymer has a structural unit other than the structural unit T1 as the terminal structural unit T, that is, a structural unit that does not contain an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms (hereinafter, , This is referred to as "structural unit T2"). The charge transporting polymer may have only one type of structural unit T2, or may have two or more types.

The structural unit T2 is not particularly limited, and includes, for example, at least one selected from the group consisting of a substituted or unsubstituted aromatic hydrocarbon structure and an aromatic heterocyclic structure. In the present embodiment, the structural unit T2 is preferably a substituted or unsubstituted aromatic hydrocarbon structure from the viewpoint of imparting durability without lowering the charge transportability, and is preferably a substituted or unsubstituted benzene. The structure is more preferable. Further, as will be described later, when the charge-transporting polymer has a polymerizable functional group at the terminal portion, the structural unit T2 has a polymerizable structure (that is, a polymerizable functional group such as a pyrrole-yl group). May be good. The structural unit T2 may have the same structure as the structural unit L except for the valence, or may have a different structure.

Specific examples of the structural unit T2 include the following. The structural unit T2 is not limited to the following.

In the above formula, R includes a hydrogen atom or a substituent mentioned as R in the structural unit L. (However, substituents having a structure in which the structural unit T2 contains an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms are excluded.) When the charge-transporting polymer has a polymerizable functional group at the terminal portion, it is preferable that at least one of R is a group containing a polymerizable functional group.

The ratio of the structural unit T1 at all ends of the charge transport polymer is 25 mol% or more, more preferably 30 mol% or more, still more preferably 35 mol%, based on the total number of ends, from the viewpoint of improving the characteristics of the organic electronic device. That is all. The upper limit is not particularly limited and is 100 mol% or less. The ratio at all ends can be determined by the charge amount ratio (molar ratio) of the monomers corresponding to the structural units at the ends used for synthesizing the charge-transporting polymer. Further, the ratio of the structural units can be calculated as an average value by using the integrated value of the spectrum derived from each structural unit in the ¹ H NMR spectrum of the charge transport polymer. When the amount to be charged is clear, it is preferable to adopt the value obtained by using the amount to be charged because it is convenient.

When the charge-transporting polymer has the structural unit T2, the ratio of the structural unit T2 at all ends is preferably 75 mol% or less, more preferably 70, based on the total number of ends, from the viewpoint of improving the characteristics of the organic electronic device. It is mol% or less, more preferably 65 mol% or less. The lower limit is not particularly limited, but may be, for example, 5 mol% or more in consideration of the introduction of a polymerizable substituent described later and the introduction of a substituent for improving the film forming property, the wettability, and the like.

(Structural unit B)
The structural unit B is a trivalent or higher structural unit constituting the branched portion when the charge-transporting polymer has a branched structure. The structural unit B is preferably a hexavalent or less structural unit, and more preferably a trivalent or tetravalent structural unit from the viewpoint of improving the durability of the organic electronic device. The structural unit B is preferably a unit having charge transportability. For example, the structural unit B is selected from at least a group consisting of a substituted or unsubstituted aromatic amine structure, a carbazole structure, and a condensed polycyclic aromatic hydrocarbon structure from the viewpoint of improving the durability of the organic electronic device. Includes one. The structural unit B may have the same structure as the structural unit L other than the valence, or may have a different structure, and has the same structure as the structural unit T except for the valence. Alternatively, it may have a different structure. Further, the structural unit B may contain an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms.

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 arene triyl group having 2 to 30 carbon atoms or a heteroarene triyl group. The arenetriyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic hydrocarbon. A heteroarene triyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic heterocycle. Ar independently represents a divalent linking group, and for example, each independently represents an arylene group or a heteroarylene group having 2 to 30 carbon atoms. Ar is preferably an arylene group, more preferably a phenylene group. Y represents a divalent linking group, for example, from the group having one or more hydrogen atoms among the substituents listed as R (excluding the group containing a polymerizable functional group) in the structural unit L. Examples thereof include a divalent group excluding one hydrogen atom. Z represents either a carbon atom, a silicon atom, or a phosphorus atom. In the structural unit, the condensed ring, W, Y, and Ar may have a substituent, and as an example of the substituent, a group containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms, And the substituents listed as R in the structural unit L can be mentioned.

In the present embodiment, the charge-transporting polymer has at least one of a structural unit T1 and a structural unit L and a structural unit B containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms as a substituent. It is preferable, and it is more preferable to have the structural unit T1. Further, the charge transporting polymer preferably has a structure branched in three or more directions having three or more ends. The "structure branched in three or more directions" means that the degree of polymerization is smaller than that of the main chain when the chain having the highest degree of polymerization is used as the main chain among various chains in one molecule of the charge-transporting polymer. It means that there is one or more side chains. In the present specification, the degree of polymerization indicates how many structural units contained in the charge-transporting polymer are contained in one molecule of the charge-transporting polymer. In the present specification, the side chain is a chain different from the main chain of the charge-transporting polymer and has at least one structural unit, and other than the side chain is regarded as a substituent.

(Polymerizable functional group)
In the present embodiment, the charge-transporting polymer preferably has at least one polymerizable functional group (also referred to as “polymerizable substituent”) 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 capable of forming a bond with each other by applying at least one of heat and light.

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

From the viewpoint of increasing the degree of freedom of the polymerizable functional group and facilitating the polymerization reaction, the main skeleton of the charge-transporting polymer and the polymerizable functional group are, for example, a linear alkylene chain having 1 to 8 carbon atoms. It is preferable that they are connected. Further, for example, when an organic layer is formed on an electrode, a hydrophilic chain such as an ethylene glycol chain or a diethylene glycol chain is used from the viewpoint of improving the affinity with a hydrophilic electrode such as ITO (indium oxide-tin oxide). It is preferable that they are connected by. Further, from the viewpoint of facilitating the preparation of the monomer used for introducing the polymerizable functional group, the charge transport polymer is used with at least one of the ends of the alkylene chain and the hydrophilic chain, that is, with these chains. At least one of the linking portion with the polymerizable functional group and the connecting portion between these chains and the skeleton of the charge-transporting polymer may have an ether bond or an ester bond. Examples of the above-mentioned "group containing a polymerizable functional group" include the polymerizable functional group itself, or a group in which a polymerizable functional group and an alkylene chain are combined. As the group containing the polymerizable functional group, for example, the group exemplified in International Publication No. 2010/1405553 can be preferably used.

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

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

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

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

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

(Weight average molecular weight)
The weight average molecular weight of the charge-transporting polymer can be appropriately adjusted in consideration of solubility in a solvent, film-forming property, and the like. The weight average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, still more preferably 10,000 or more, from the viewpoint of excellent charge transportability. The weight average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, and more preferably 400,000 or less, from the viewpoint of maintaining good solubility in the solvent and facilitating the preparation of the ink composition. The following is more preferable, and 300,000 or less is most preferable.

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

(Ratio of structural units)
The proportion of structural units contained in the charge-transporting polymer containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms is 9 mol% or more based on all structural units from the viewpoint of improving the characteristics of the organic electronic device. Is preferable, 27 mol% or more is more preferable, and 36 mol% or more is further preferable. The upper limit is not particularly limited and is 100 mol% or less.

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 30 mol% or more, based on all the structural units, from the viewpoint of obtaining sufficient charge transportability. Is more preferable. Further, the ratio of the structural unit L is preferably 95 mol% or less, more preferably 90 mol% or less, more preferably 85 mol% or less, based on all the structural units, in consideration of the structural unit T and the structural unit B to be introduced as needed. More preferably, it is mol% or less.

The ratio of the structural unit T (the total of the structural units T1 and T2) contained in the charge-transporting polymer is from the viewpoint of improving the characteristics of the organic electronics element or suppressing the increase in viscosity, and the charge-transporting polymer is satisfactorily synthesized. From the viewpoint, 5 mol% or more is preferable, 10 mol% or more is more preferable, and 15 mol% or more is further preferable, based on all structural units. The ratio of the structural unit T is preferably 60 mol% or less, more preferably 55 mol% or less, still more preferably 50 mol% or less, based on all structural units, from the viewpoint of obtaining sufficient charge transportability.

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

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

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

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

In a particularly preferable aspect of the present embodiment, the charge transporting polymer is at least one of a structural unit having an aromatic amine structure and a structural unit having a carbazole structure from the viewpoint of having high hole injection property, hole transport property and the like. Is preferably a compound having the main structural unit (main skeleton). Further, the charge transporting polymer is preferably a compound having at least two or more polymerizable substituents from the viewpoint of facilitating multi-layering. The polymerizable substituent is preferably a cyclic ether group, a group having a carbon-carbon multiple bond, or the like from the viewpoint of having excellent curability.

(Production method)
The charge-transporting polymer in the present embodiment is a monomer mixture containing at least a monomer having a structural unit having an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms and a monomer having a structural unit having a charge-transporting property. It is preferably a copolymer of. In particular, the monomer having a structural unit having a charge transport property is preferably a monomer having a structural unit having a hole transport property. For example, one or more monomers having the structural unit T1 and one or more monomers having the structural unit L, and optionally another one or more monomers (for example, a monomer having the structural unit B). It can be preferably produced by copolymerizing these monomers with a mixture of monomers which may be contained. The form of copolymerization may be alternating, random, block or graft copolymers, or copolymers having an intermediate structure thereof, for example, random copolymers having a blocking property. ..

The charge-transporting polymer can be produced by various synthetic methods and is not particularly limited. For example, known coupling reactions such as Suzuki coupling, Negishi coupling, Sonogashira coupling, Still coupling, and Buchwald-Hartwig coupling can be used. Suzuki coupling causes a 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 to each other.

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

[Dopant]
The organic electronics material can contain any additive and may further contain, for example, a dopant. The dopant is not particularly limited as long as it can exhibit a doping effect and improve charge transportability by being added to an organic electronic material. Doping includes p-type doping and n-type doping. In p-type doping, a substance that acts as an electron acceptor as a dopant is used, and in n-type doping, a substance that acts as an electron donor as a dopant is used. 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 electronics material may be a dopant that exhibits the effects of either p-type doping or n-type doping. Further, one kind of dopant may be added alone, or a plurality of 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 acid, protonic acid, transition metal compound, ionic compound, halogen compound, and π-conjugated compound. Specifically, as Lewis acid, FeCl ₃ , PF ₅ , AsF ₅ , SbF ₅ , BF ₅ , BCl ₃ , BBr _3, etc .; as sulfonic acid, HF, HCl, HBr, HNO ₅ , H ₂ SO ₄ , inorganic acids such as HClO _4, benzenesulfonic acid, p- toluenesulfonic acid, dodecylbenzenesulfonic acid, polyvinyl sulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, 1-butane sulfonic acid, vinyl phenyl sulfonate , Organic acids such as camphorsulfonic acid; as transition metal compounds, FeOCl, TiCl ₄ , ZrCl ₄ , HfCl ₄ , NbF ₅ , AlCl ₃ , NbCl ₅ , TaCl ₅ , MoF ₅ ; as ionic compounds, tetrakis (pentafluoro) phenyl) borate, tris (trifluoromethanesulfonyl) Mechidoion, bis (trifluoromethanesulfonyl) imide ion, hexafluoroantimonate ion, AsF ₆ ^- (hexafluoro arsenic acid ions), BF ₄ ^- (tetrafluoroborate), PF ^- ₆ salt having a perfluoroalkyl anions of (hexafluorophosphate) and the like, salts with a conjugate base of the aforementioned protonic acid as anion; halogen _{compounds, Cl 2, Br 2, I} 2, ICl, ICl 3 , IBr, IF, etc .; Examples of the π-conjugated compound include TCNE (tetracyanoethylene) and TCNQ (tetracyanoquinodimethane). It is also possible to use the electron-accepting compounds described in JP-A-2000-36390, JP-A-2005-75948, JP-A-2003-213002, and the like. As the dopant used for p-type doping, it is preferable to use Lewis acid, an ionic compound, a π-conjugated compound or the like.

The dopant used for n-type doping is an electron-donating compound, for example, an alkali metal such as Li, Cs; an alkaline earth metal such as Mg, Ca; an alkali metal such as LiF, Cs ₂ CO _3, or an alkaline soil. Examples include salts of similar metals; 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 the dopant in order to facilitate the change in the solubility of the organic layer.

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

[Content]
The content of the charge-transporting polymer in the organic electronics material is preferably 50% by mass or more, more preferably 70% by mass or more, based on the total mass of the organic electronics material from the viewpoint of obtaining good charge-transporting property. , 80% by mass or more is more preferable. The upper limit of the content of the charge-transporting polymer is not particularly limited, and may be 100% by mass. Considering that the organic electronics material contains additives such as dopants, the content of the charge-transporting polymer may be, for example, 95% by mass or less, 90% by mass or less, etc. with respect to the total mass of the organic electronics material.

When the organic electronics material contains a dopant, the content thereof is preferably 0.01% by mass or more, preferably 0.1% by mass, based on the total mass of the organic electronics material from the viewpoint of improving the charge transportability of the organic electronics material. It is more preferably mass% or more, and further preferably 0.5 mass% or more. Further, from the viewpoint of maintaining good film forming property, 50% by mass or less is preferable, 30% by mass or less is more preferable, and 20% by mass or less is further preferable with respect to the total mass of the organic electronics material.

<Ink composition>
The ink composition of the present embodiment contains the organic electronic material of the above-described embodiment and a solvent capable of dissolving or dispersing the organic electronic 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. Examples of the organic solvent include alcohols such as methanol, ethanol and isopropyl alcohol; alkanes such as pentane, hexane and octane; cyclic alkanes such as cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, tetraline and diphenylmethane; ethylene glycol. Alibo ethers such as dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, Aromatic ethers such as 4-methoxytoluene, 2,3-dimethylanisole and 2,4-dimethylanisole; aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate and n-butyl lactate; phenyl acetate, propionic acid Aromatic esters such as phenyl, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate; amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide; dimethylsulfoxide, tetrahydrofuran, acetone , Chloroform, methylene chloride and the like. Aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers and the like are preferable.

[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 that the ink composition can be easily prepared, it is preferable to use a substance having both a function as a dopant and a function as a polymerization initiator. Examples of such a substance include the above-mentioned ionic compounds and the like.

[Additive]
The ink composition may further contain an additive as an optional component. Additives include, for example, polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, antioxidants, oxidizing agents, reducing agents, surface modifiers, emulsifiers, defoamers, etc. Dispersants, surfactants and the like can be mentioned.

[Content]
The content of the solvent in the ink composition can be determined in consideration of application to various coating methods. For example, the ink composition preferably contains an amount of the solvent in which the ratio of the charge transporting polymer to the solvent is 0.1% by mass or more, and preferably contains an amount of the solvent in an amount of 0.2% by mass or more. Is more preferable, and it is further preferable to contain an amount of the solvent in an amount of 0.5% by mass or more. Further, the ink composition preferably contains an amount of the solvent in which the ratio of the charge-transporting polymer to the solvent is 20% by mass or less, and more preferably 15% by mass or less. It is more preferable to contain the solvent in an amount of 10% by mass or less.

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

When the charge-transporting polymer has a polymerizable functional group, the polymerization reaction of the charge-transporting polymer can be allowed to proceed by light irradiation, heat treatment, or the like, and the solubility of the organic layer can be changed. By stacking organic layers having different solubilities, it is possible to easily increase the number of layers of organic electronic devices. As for the method for forming the organic layer, for example, the description of International Publication No. 2010/1405553 can be incorporated.

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

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

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

FIG. 1 is a schematic cross-sectional view showing an embodiment of an organic EL device. The organic EL device shown in FIG. 1 is a multi-layered device, and has a substrate 8, an anode 2, a hole injection layer 3, a hole transport layer 6, a light emitting layer 1, an electron transport layer 7, an electron injection layer 5, and a cathode. 4 has a multi-layer structure in which 4 are laminated in this order. Hereinafter, each layer will be described.

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

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

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

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

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

[Hole injection layer, hole transport layer]
The above-mentioned organic layer is preferably used as at least one of the hole injection layer and the hole transport layer, and more preferably at least as the hole transport layer. As described above, these layers can be easily formed by using an ink composition containing an organic electronic material.
When the organic EL device has the above-mentioned organic layer as a hole transport layer and further has a hole injection layer, a known material can be used for the hole injection layer. Further, when the organic EL element has the above-mentioned organic layer as a hole injection layer and further has a hole transport layer, a known material can be used for the hole transport layer.

When a material containing a triphenylamine structure is used for the hole injection layer, it is preferable to use the organic electronics material of the above-described embodiment for the hole transport layer from the viewpoint of energy level with respect to hole movement. is there. In particular, when the hole injection layer contains a polymerization initiator and the hole transport layer uses a branched polymer having a polymerizable substituent as the above-mentioned charge transport polymer, the hole transport layer can be cured. Therefore, it is possible to further apply a light emitting layer made of ink or the like to the upper layer.

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

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

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

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

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

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

[Sealing]
The organic EL element may be sealed in order to reduce the influence of the outside air and prolong the life. As the material used for sealing, a plastic film such as glass, epoxy resin, acrylic resin, polyethylene terephthalate or polyethylene naphthalate, or an inorganic substance such as silicon oxide or silicon nitride can be used, but the material is not limited thereto. Absent. The sealing method is not particularly limited, and a known method can be used.

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

As a method for forming the white organic EL element, a method can be used in which a plurality of luminescent materials are used to simultaneously emit a plurality of luminescent colors to mix the colors. The combination of a plurality of emission colors is not particularly limited, but is a combination containing three emission maximum wavelengths of blue, green, and red, a combination containing two emission maximum wavelengths such as blue and yellow, and yellowish green and orange. Can be mentioned. The emission color can be controlled by adjusting the type and amount of the emission material.

<Display element, lighting device, display device>
The display element of the present embodiment includes the organic EL element of the above-described embodiment. For example, 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). There are two methods for forming an image: a simple matrix type in which individual organic EL elements arranged on a panel are directly driven by electrodes arranged in a matrix, and an active matrix type in which a thin film transistor is arranged and driven in each element.

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

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. Unless otherwise specified, "%" means "mass%".

<Preparation of Pd catalyst>
Tris (dibenzylideneacetone) dipalladium (73.2 mg, 80 μmol) was weighed in a sample tube at room temperature in a glove box under a nitrogen atmosphere, 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 into 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 to catalyze. All solvents were degassed by nitrogen bubbles for at least 30 minutes before use.

<Synthesis of charge transport polymer 1>
In a three-necked round-bottom flask, the following monomer L-1 (5.0 mmol), the following monomer B-1 (2.0 mmol), the following monomer T2-1 (2.0 mmol), the following monomer T2-2 (2.0 mmol), And anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. After stirring for 30 minutes, a 10% tetraethylammonium hydroxide aqueous solution (20 mL) was added. All solvents were degassed by nitrogen bubbles for at least 30 minutes before use. The mixture was heated to reflux for 2 hours. All operations up to this point 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 collected by suction filtration and washed with methanol-water (9: 1). The resulting precipitate was dissolved in toluene, poured into methanol and reprecipitated. The obtained precipitate is collected by suction filtration, 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) is added. It was stirred in the evening. After the stirring was completed, the metal adsorbent and the insoluble matter were filtered off, and the filtrate was concentrated on a rotary evaporator. The concentrate was dissolved in toluene and then poured into methanol-acetone (8: 3) for reprecipitation. The resulting precipitate was collected by suction filtration and washed with methanol-acetone (8: 3). The obtained precipitate was vacuum dried to obtain a charge-transporting polymer 1.

The obtained charge-transporting polymer 1 had a number average molecular weight of 5,200 and a weight average molecular weight of 41,200. The charge transporting polymer 1 is a structural unit derived from the monomer L-1, a structural unit derived from the monomer B-1, a structural unit derived from the monomer T2-1 having an oxetane group, and a structure derived from the monomer T2-2. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 18.2%, and 18.2%.

The number average molecular weight and the mass average molecular weight were measured by GPC (polystyrene conversion) using tetrahydrofuran (THF) as an eluent. The measurement conditions are as follows.
Liquid transfer 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 (HPLC) For use, does not contain stabilizers) Fujifilm Wako Pure Chemical Industries, Ltd.
Flow velocity: 1 mL / min
Column temperature: Room temperature Molecular weight standard substance: Standard polystyrene

<Synthesis of charge transport polymer 2>
In a three-necked round-bottom flask, the above-mentioned monomer L-1 (5.0 mmol), the following monomer B-2 (2.0 mmol), the following monomer T1-1 (3.0 mmol), and the above-mentioned monomer T2-1 (1.0 mmol). ) And anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. Subsequently, the charge transport polymer 2 was synthesized in the same manner as the charge transport polymer 1 was synthesized.

The obtained charge-transporting polymer 2 had a number average molecular weight of 16,800 and a weight average molecular weight of 76,100. The charge-transporting polymer 2 is a structural unit derived from the monomer L-1, a structural unit derived from the monomer B-2, a structural unit derived from the monomer T1-1, and a structure derived from the monomer T2-1 having an oxetane group. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 27.3%, and 9.1%.

<Synthesis of charge transport polymer 3>
In a three-necked round-bottom flask, the above-mentioned monomer L-1 (5.0 mmol), the above-mentioned monomer B-2 (2.0 mmol), the following monomer T1-2 (3.0 mmol), and the above-mentioned monomer T2-1 (1. 0 mmol) and anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. Subsequently, the charge transport polymer 3 was synthesized in the same manner as the charge transport polymer 1 was synthesized.

The obtained charge-transporting polymer 3 had a number average molecular weight of 15,900 and a weight average molecular weight of 68,900. The charge-transporting polymer 3 has a structural unit derived from monomer L-1, a structural unit derived from monomer B-2, a structural unit derived from monomer T1-2, and a structure derived from monomer T2-1 having an oxetane group. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 27.3%, and 9.1%.

<Synthesis of charge transport polymer 4>
In a three-necked round-bottom flask, the above-mentioned monomer L-1 (5.0 mmol), the above-mentioned monomer B-2 (2.0 mmol), the following monomer T1-3 (3.0 mmol), and the above-mentioned monomer T2-1 (1. 0 mmol) and anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. Hereinafter, the charge transport polymer 4 was synthesized in the same manner as the charge transport polymer 1.

The obtained charge-transporting polymer 4 had a number average molecular weight of 15,600 and a weight average molecular weight of 65,000. The charge-transporting polymer 4 has a structural unit derived from the monomer L-1, a structural unit derived from the monomer B-2, a structural unit derived from the monomer T1-3, and a structure derived from the monomer T2-1 having an oxetane group. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 27.3%, and 9.1%.

<Synthesis of charge transport polymer 5>
In a three-necked round-bottom flask, the above-mentioned monomer L-1 (5.0 mmol), the above-mentioned monomer B-2 (2.0 mmol), the following monomer T1-4 (3.0 mmol), and the above-mentioned monomer T2-1 (1. 0 mmol) and anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. Subsequently, the charge transport polymer 5 was synthesized in the same manner as the charge transport polymer 1 was synthesized.

The obtained charge-transporting polymer 5 had a number average molecular weight of 14,500 and a weight average molecular weight of 58,500. The charge transporting polymer 5 is a structural unit derived from the monomer L-1, a structural unit derived from the monomer B-2, a structural unit derived from the monomer T1-4, and a structure derived from the monomer T2-1 having an oxetane group. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 27.3%, and 9.1%.

<Synthesis of charge transport polymer 6>
In a three-necked round-bottom flask, the above-mentioned monomer L-1 (5.0 mmol), the above-mentioned monomer B-2 (2.0 mmol), the following monomer T2-3 (3.0 mmol), and the above-mentioned monomer T2-1 (1. 0 mmol) and anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. Subsequently, the charge transport polymer 6 was synthesized in the same manner as the charge transport polymer 1.

The obtained charge-transporting polymer 6 had a number average molecular weight of 16,300 and a weight average molecular weight of 82,600. The charge-transporting polymer 6 has a structural unit derived from the monomer L-1, a structural unit derived from the monomer B-2, a structural unit derived from the monomer T2-3, and a structure derived from the monomer T2-1 having an oxetane group. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 27.3%, and 9.1%.

<Synthesis of charge transport polymer 7>
In a three-necked round-bottom flask, the above-mentioned monomer L-1 (5.0 mmol), the above-mentioned monomer B-2 (2.0 mmol), the following monomer T2-4 (3.0 mmol), and the above-mentioned monomer T2-1 (1. 0 mmol) and anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. Subsequently, the charge transport polymer 7 was synthesized in the same manner as the charge transport polymer 1.

The obtained charge-transporting polymer 7 had a number average molecular weight of 16,500 and a weight average molecular weight of 75,900. The charge-transporting polymer 7 has a structural unit derived from the monomer L-1, a structural unit derived from the monomer B-2, a structural unit derived from the monomer T2-4, and a structure derived from the monomer T2-1 having an oxetane group. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 27.3%, and 9.1%.

<Synthesis of charge transport polymer 8>
In a three-necked round-bottom flask, the above-mentioned monomer L-1 (5.0 mmol), the above-mentioned monomer B-2 (2.0 mmol), the following monomer T2-5 (3.0 mmol), and the above-mentioned monomer T2-1 (1. 0 mmol) and anisole (20 mL) were added, and the prepared Pd catalyst solution (7.5 mL) was further added. Subsequently, the charge transport polymer 8 was synthesized in the same manner as the charge transport polymer 1.

The obtained charge-transporting polymer 8 had a number average molecular weight of 15,400 and a weight average molecular weight of 74,600. The charge-transporting polymer 8 has a structural unit derived from the monomer L-1, a structural unit derived from the monomer B-2, a structural unit derived from the monomer T2-5, and a structure derived from the monomer T2-1 having an oxetane group. It had units, and the proportions (molar ratios) of each structural unit were 45.5%, 18.2%, 27.3%, and 9.1%.

<Manufacturing of organic EL element>
[Examples 1 to 4 and Comparative Examples 1 to 3]
Under a nitrogen atmosphere, the charge-transporting polymer 1 (10.0 mg), the following electron-accepting compound 1 (0.5 mg), and toluene (2.3 mL) are mixed to prepare an ink composition for forming a hole injection layer. Prepared. An ITO patterned with a width of 1.6 mm is formed on a glass substrate, and the ink composition is spin-coated on the formed ITO at a rotation speed of 3,000 min ^-1 , and then on a hot plate at 220 ° C. for 10 minutes. It was heated and cured to form a hole injection layer (25 nm).

Next, any one of the charge-transporting polymers 2 to 8 (10.0 mg) shown in Table 1, the above-mentioned electron-accepting compound 1 (0.5 mg) and toluene (1.15 mL) were mixed and positively mixed. An ink composition for forming a hole transport layer was prepared. The ink composition was spin-coated on the formed hole injection layer at a rotation speed of 3,000 min ^-1 , and then heated on a hot plate at 200 ° C. for 10 minutes to cure the hole transport layer (40 nm). Formed. In each Example and Comparative Example, the hole transport layer could be formed without dissolving the hole injection layer.

The glass substrate on which the ITO, the hole injection layer, and the hole transport layer are laminated is transferred into a vacuum vapor deposition machine, and CBP: Ir (ppy) ₃ (94: 6, 30 nm), BAlq ( 10 nm), TPBi (30 nm), LiF (0.8 nm), and Al (100 nm) were deposited in this order by a vapor deposition method and sealed to prepare an organic EL device.

When a voltage was applied to the organic EL elements obtained in Examples 1 to 4 and Comparative Examples 1 to 3, green light emission was confirmed. For each organic EL element, the light emission lifetime (luminance half-time) at an initial brightness of 5,000 cd / m ² was measured.
The measurement results are shown in Table 2.

As shown in Table 2, from the comparison between Examples 1 to 4 and Comparative Examples 1 to 3, by using the organic electronics material of the present embodiment for the hole transport layer, a long-life organic substance having excellent drive stability is used. It was found that an EL element can be obtained.

<Manufacturing of white organic EL element (lighting device)>
[Example 5]
Under a nitrogen atmosphere, charge-transporting polymer 1 (10.0 mg), electron-accepting compound 1 (0.5 mg), and toluene (2.3 mL) are mixed to prepare an ink composition for forming a hole injection layer. did. An ITO patterned with a width of 1.6 mm is formed on a glass substrate, and the ink composition is spin-coated on the formed ITO at a rotation speed of 3,000 min ^-1 , and then on a hot plate at 220 ° C. for 10 minutes. It was heated and cured to form a hole injection layer (25 nm).

The charge-transporting polymer 2 (20 mg) and toluene (1.15 mL) were mixed to prepare an ink composition for forming a hole transport layer. The ink composition was spin-coated on the hole injection layer at a rotation speed of 3,000 min ^-1 , and then heated and cured on a hot plate at 200 ° C. for 10 minutes to form a hole transport layer (40 nm). .. The hole transport layer could be formed without dissolving the hole injection layer.

CDBP (15 mg), FIR (pic) (0.9 mg), Ir (ppy) ₃ (0.9 mg), (btp) ₂ Ir (acac) (1.2 mg), and dichlorobenzene (0 mg) under a nitrogen atmosphere. .5 mL) was mixed to prepare an ink composition for forming a light emitting layer. The ink composition was spin-coated on the hole transport layer at a rotation speed of 3,000 min ^-1 , and then heated and dried on a hot plate at 80 ° C. for 5 minutes to form a light emitting layer (40 nm). The light emitting layer could be formed without dissolving the hole transport layer.

A glass substrate in which the hole injection layer, the hole transport layer, and the light emitting layer are laminated in this order is transferred into a vacuum vapor deposition machine, and BAlq (10 nm), TPBi (30 nm), LiF (0.5 nm), and LiF (0.5 nm) are placed on the light emitting layer. Al (100 nm) was formed in this order by a vapor deposition method. Then, it was sealed to produce a white organic EL device. The obtained white organic EL element could be used as a lighting device.

[Comparative Example 4]
A white organic EL device was produced in the same manner as in Example 5 except that the charge-transporting polymer 2 was changed to the charge-transporting polymer 6. The light emitting layer could be formed without dissolving the hole transport layer. Moreover, the white organic EL element could be used as a lighting device.

A voltage was applied to the white organic EL elements obtained in Example 5 and Comparative Example 4, and the light emission lifetime (luminance half-time) was measured with an initial brightness of 1,000 cd / m ² . When the emission lifetime of the white organic EL element of Example 5 was 1, the emission lifetime of the white organic EL element of Comparative Example 4 was 0.23. The white organic EL device of Example 5 showed an excellent emission lifetime.

As described above, the excellent effect of this embodiment was shown by using the examples. In addition to the charge-transporting polymer used in the examples, a charge-transporting polymer having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms is used to obtain an organic EL device having a long life. It is possible and exhibits excellent effects as well.

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

Claims (18)

An organic electronic material comprising a charge-transporting polymer or oligomer having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms. The organic electronic material according to claim 1, wherein the aromatic ring contains an aromatic hydrocarbon. The organic electronic material according to claim 1 or 2, wherein the charge-transporting polymer or oligomer has at least one terminal structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms. The organic electronic material according to any one of claims 1 to 3, wherein the charge-transporting polymer or oligomer has a structural unit represented by the following general formula.

(In the formula, Ar represents a substituted or unsubstituted aromatic ring. R ¹ represents a linear alkyl group having 10 to 24 carbon atoms. * Represents a binding site with another structural unit.) The charge-transporting polymer or oligomer is divalent including at least one selected from the group consisting of a substituted or unsubstituted aromatic amine structure, a carbazole structure, a thiophene structure, a fluorene structure, a benzene structure, and a pyrrole structure. The organic electronic material according to any one of claims 1 to 4, which has the structural unit of. The organic electronic material according to any one of claims 1 to 5, wherein the charge-transporting polymer or oligomer has three or more ends. Claims 1 to 1, wherein the charge-transporting polymer or oligomer has a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms at the terminal of 25 mol% or more based on the total number of terminals. The organic electronic material according to any one of 6. A monomer in which the charge-transporting polymer or oligomer contains at least a monomer having a structural unit having a hole-transporting property and a monomer having a structural unit containing an aromatic ring having a linear alkyl group having 10 to 24 carbon atoms. The organic electronics material according to any one of claims 1 to 7, which is a copolymer of a mixture. The organic electronic material according to any one of claims 1 to 8, wherein the charge-transporting polymer or oligomer further has a polymerizable functional group. An ink composition containing the organic electronic material according to any one of claims 1 to 9 and a solvent. An organic layer formed by using the organic electronic material according to any one of claims 1 to 9 or the ink composition according to claim 10. An organic electronic device including at least one organic layer according to claim 11. An organic electroluminescent device comprising at least one organic layer according to claim 11. The organic electroluminescence device according to claim 13, further comprising a flexible substrate. The organic electroluminescence device according to claim 13, further comprising a resin film substrate. A display device including the organic electroluminescence device according to any one of claims 13 to 15. A lighting device comprising the organic electroluminescence device according to any one of claims 13 to 15. A display device including the lighting device according to claim 17 and a liquid crystal element as a display means.

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