JP2018125450A - Charge transporting material, ink composition using the same, organic electronic device, organic electroluminescent device, display device, lighting apparatus, and display apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge transporting material containing a charge transporting polymer, which can be used for an organic electronic device, an ink composition containing the same, an organic electronic device excellent in luminous efficiency and emission lifetime, an organic EL device, a display device using those, a lighting device, and a display device.SOLUTION: The charge transporting polymer containing a trivalent structural unit having a spirobifluorene derivative skeleton is constituted and used as a charge transporting material.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a charge transport material and an ink composition using the material. In another embodiment of the present invention, an organic electronics element, an organic electroluminescence element, a display element, a lighting device, and an organic layer using the charge transporting material or an ink composition containing the material, and The present invention relates to a display device.

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

  Examples of the organic electronics element include an organic electroluminescence element (hereinafter also referred to as “organic EL element”), an organic photoelectric conversion element, and an organic transistor.

  Among organic electronic elements, organic EL elements are attracting attention as an alternative to incandescent lamps, gas-filled lamps, or as large-area solid-state light source applications. 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. In the polymer organic EL element, a polymer material is used as an organic material, and in the low molecular organic EL element, a low molecular material is used. Compared with low-molecular-weight organic EL elements, which are mainly deposited in a vacuum system, polymer-type organic EL elements can be easily formed by wet processes such as printing and inkjet. It is expected as an indispensable element for screen organic EL displays.

  Therefore, in recent years, development and examination of a polymer material suitable for a wet process has been advanced (Patent Document 1).

JP 2006-279007 A

  In general, when an organic EL element is formed using a polymer material, it has the feature that cost reduction and area increase are easy. Therefore, in recent years, various methods for improving various characteristics of the organic EL element have been studied by multilayering an organic layer produced using a polymer material and separating the functions of each layer. However, an organic EL element having an organic layer manufactured using a conventional polymer material is desired to be further improved in characteristics such as driving voltage, light emission efficiency, and light emission lifetime.

  In view of the above, an embodiment of the present invention has an object to provide a charge transporting material containing a polymer material that can be suitably used for an organic electronic device, and an ink composition containing the material. Another embodiment of the present invention is an organic electronics element, an organic EL element, and a display element and an illuminating device using the charge transporting material or the ink composition, which are excellent in luminous efficiency and luminous lifetime. And a display device.

  As a result of intensive studies, the present inventors have found that a charge transporting polymer having a specific structural unit is suitable as a charge transporting material constituting an organic layer of an organic electronics element, and to complete the present invention. It came. That is, the embodiment of the present invention relates to the following items.

One embodiment of the present invention relates to a charge transporting material including a charge transporting polymer having a structure branched in three or more directions, wherein the charge transporting polymer includes a trivalent structural unit having a spirobifluorene derivative skeleton. .
Here, the charge transporting polymer preferably further includes a divalent structural unit having charge transporting property. The divalent structural unit is preferably selected from the group consisting of a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, bithiophene structure, benzene structure, and fluorene structure. The aromatic amine structure preferably includes a triphenylamine structure or an aniline structure. The charge transporting polymer preferably includes a partial structure in which three of the divalent structural units are bonded to one of the trivalent structural units having the spirobifluorene derivative skeleton. The charge transporting material is preferably used as a hole transporting material.

One embodiment of the present invention relates to an ink composition comprising the charge transporting material and a solvent.
One embodiment of the present invention relates to an organic electronic device having an organic layer containing the charge transporting material.
One embodiment of the present invention relates to organic electroluminescence having an organic layer containing the charge transporting material. Here, it is preferable that the organic electroluminescent element further includes a flexible substrate. The flexible substrate preferably includes a resin film.
One embodiment of the present invention relates to a display device comprising the organic electroluminescence device.
One embodiment of the present invention relates to a proof device comprising the organic electroluminescent element.
One embodiment of the present invention relates to a display device including the illumination device and a liquid crystal element as a display unit.

  According to the embodiments of the present invention, it is possible to provide a charge transporting material containing a charge transporting polymer suitable as a constituent material of an organic electronic element, and an ink composition containing the material. Further, using the above charge transporting material or ink composition, an organic electronics element and an organic EL element having a low driving voltage and excellent light emission efficiency and lifetime, and a display element, an illumination device, and a display using the same An apparatus can be provided.

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

Hereinafter, although embodiment of this invention is described, this invention is not limited to these embodiment.
<Charge transport material>
The charge transport material of this embodiment includes a charge transport polymer having a structure branched in three or more directions. The charge transporting polymer has an ability to transport charges. Hereinafter, the charge transporting polymer will be described in detail.

(Charge transporting polymer)
In the above charge transporting polymer, “a structure branched in three or more directions” means that the main chain is a chain having the largest degree of polymerization among various chains in one molecule of the charge transporting polymer. It means that there is one or more side chains having the same degree of polymerization or a lower degree of polymerization. In the present embodiment, the degree of polymerization represents how many monomer units used for synthesizing the charge transporting polymer per molecule of the charge transporting polymer. In the present embodiment, the side chain is a chain different from the main chain of the charge transporting polymer and has at least one structural unit. Other than that, the side chain is regarded as a substituent instead of a side chain. The “polymer” is a concept including a so-called “oligomer” having a small number of structural units.

  The charge transporting polymer includes a trivalent or higher structural unit (hereinafter, also referred to as “structural unit B”) that constitutes the branched portion of the “structure branched in three or more directions” described above. Here, the term “trivalent or higher” in the structural unit means that there are three or more bonds in the structural unit that form a binding site with another structural unit. That is, the valence of the structural unit corresponds to the number of bonds.

  In one embodiment, the charge transporting polymer includes a trivalent structural unit having a spirobifluorene derivative skeleton (hereinafter, also referred to as “structural unit B1”) as the structural unit B in the molecule. . Here, the trivalent structural unit B1 having a spirobifluorene derivative skeleton means that there are three bonds directly connected to the spirobifluorene derivative ring in the structural unit. The position of the bond directly linked to the spirobifluorene derivative ring is not particularly limited, and the spirobifluorene derivative may have a substituent.

上記一般式（Ｘ）において、「＊」は他の構造単位との結合部位を示し、Ｒは置換基を示す。また、一般式（Ｘ）には示していないが、結合部位を有するベンゼン環に、さらに任意の置換基が含まれていても良い。Ｒは、−ＮＡｒＡｒ’(Ａｒ及びＡｒ’は置換されていてもよいアリール基又はヘテロアリール基であり、ＡｒとＡｒ’が環を形成していてもよい。) であることが好ましく、Ａｒ及びＡｒ’は置換されていてもよいフェニル基であることが好ましい。 That is, an example of the structural unit B1 can be represented by the following general formula (X).

In the above general formula (X), “*” represents a binding site with another structural unit, and R represents a substituent. Further, although not shown in the general formula (X), the benzene ring having a binding site may further contain an arbitrary substituent. R is preferably —NArAr ′ (Ar and Ar ′ are an optionally substituted aryl group or heteroaryl group, and Ar and Ar ′ may form a ring), Ar and Ar ′ is preferably an optionally substituted phenyl group.

For example, an example of the structural unit B1 can be represented by the following general formula (Y). “*” And “R” are the same as in the general formula (X).

In the most preferred embodiment, the charge transporting material includes a structural unit B1 represented by the following general formula (1) or (2). As the structural unit B1, a plurality of structural units can be included in combination. For example, a trivalent structural unit B1 other than those represented by the following general formula (1) or (2) may be included.

In formulas (1) and (2), R _{1 to} R ₁₈ are each independently a hydrogen atom, a linear, cyclic or branched alkyl group, alkenyl group, alkynyl group having 1 to 22 carbon atoms, And an alkoxy group and at least one selected from the group consisting of an aryl group and a heteroaryl group having 2 to 30 carbon atoms. The aryl group and heteroaryl group may have a substituent, and the substituent is preferably a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms.
More preferably, R _{1 to} R ₁₈ are each independently a hydrogen atom, a linear, cyclic or branched alkyl group, alkenyl group, alkynyl group, and alkoxy group having 1 to 8 carbon atoms, and a carbon number. It is at least one selected from the group consisting of 2 to 16 aryl groups and heteroaryl groups. More preferably, R _{1 to} R ₁₈ are each a hydrogen atom or an alkyl group, and in the latter case, one alkyl group is preferably included for each benzene ring.

A compound having a spirobifluorene derivative skeleton is characterized by being rigid and stable. In addition, since the charge transporting polymer having a branched structure is excellent in solubility and curability, it is easy to form an organic layer by a coating method. Therefore, a useful charge transporting material can be formed using a charge transporting polymer including a specific structural unit having a spirobifluorene derivative skeleton. Moreover, durability of an organic EL element etc. can be improved by using such a charge transport material.
In particular, as shown in the general formula (1), the structural unit B1 contains a spirobifluorene structure and a triphenylamine structure in a shared ring, so that the stability of the charge transporting polymer is high. As a result, it is considered that when used as a hole injection layer or a hole transport layer, luminance deterioration can be suppressed and the light emission lifetime can be extended.

(Structure of charge transporting polymer)
In one embodiment, the charge transporting polymer includes the structural unit B1 as the trivalent or higher structural unit B constituting the branched portion, and further includes a monovalent structural unit (hereinafter referred to as “ Also referred to as “structural unit T”). In another embodiment, the charge transporting polymer contains the structural unit B1 as the trivalent or higher structural unit B, and further has a charge transporting divalent structural unit (hereinafter referred to as “structural unit L”). And the above-mentioned monovalent structural unit T. The charge transporting polymer may contain only one kind of each structural unit, or may contain plural kinds of structural units. In the charge transporting polymer, each structural unit is bonded to each other at a binding site of “monovalent” to “trivalent or higher”.

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

  Although not particularly limited, in one embodiment, the charge transporting polymer includes a trivalent structural unit B1 having a spirobifluorene derivative skeleton as the trivalent or higher structural unit B, and includes 1 of the structural unit B1. It is preferable to include a partial structure in which three divalent structural units L having charge transporting properties are bonded. Hereinafter, each structural unit will be specifically described.

(Structural unit B)
The structural unit B is a trivalent or higher structural unit that forms a branched portion in a charge transporting polymer having a structure branched in three or more directions. 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 a charge transporting property.
In the present embodiment, the structural unit B includes at least a trivalent structural unit B1 having the spirobifluorene derivative skeleton, and includes a trivalent or higher structural unit B2 having other charge transport properties as necessary. But you can.

  From the viewpoint of obtaining effects such as durability and low driving voltage, in one embodiment, the proportion of the structural unit B1 in the charge transporting polymer is preferably 1 mol% or more, more preferably 3 mol% or more, and 5 mol%. The above is most preferable. On the other hand, from the viewpoint of further improving the charge transportability of the charge transportable polymer, the charge transportable polymer preferably includes another structural unit having excellent charge transportability in addition to the structural unit B1. From such a viewpoint, in one embodiment, the proportion of the structural unit B1 in the charge transporting polymer is preferably 50 mol% or less, more preferably 40 mol% or less, and further preferably 30 mol% or less.

  By using a charge transporting material containing a charge transporting polymer in which the proportion of the structural unit B1 is within the above range, an organic EL device having excellent durability and luminous efficiency can be easily obtained. In addition, the charge transporting polymer prepared so that the proportion of the structural unit B1 is within the above range is preferable in that it has an appropriate molecular weight as the charge transporting material.

  The proportion of the structural unit B1 in the charge transporting polymer can be achieved by adjusting the amount of the monomer compound having the structural unit B1 when preparing the charge transporting polymer. The proportion of the structural unit B1 can be calculated from the ratio (molar ratio) of the monomer compound having the structural unit B1 to the total charged amount of various monomer compounds used as raw materials. The proportion of the structural unit B1 can also be calculated from the integral ratio of the characteristic peaks by measuring the NMR of the charge transporting polymer.

  In one embodiment, the charge transporting polymer preferably includes the structural unit B1 and the other trivalent or higher structural unit B2 as the trivalent or higher structural unit B. Here, the ratio of the structural unit B1 to the total amount of the structural units B1 and B2 is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more. By adjusting the proportion of the structural unit B1 within the above range, in addition to excellent charge transportability, it is easy to obtain the advantage of the structural unit having a spirobifluorene derivative skeleton. The proportion of the structural unit B1 in the trivalent or higher structural unit B may be 100 mol%.

  The structural unit B2 includes, for example, a substituted or unsubstituted aromatic amine structure, carbazole structure, condensed polycyclic aromatic hydrocarbon structure (provided that the spirobifluorene derivative skeleton is present from the viewpoint of improving the durability of the organic electronics element. Except for the trivalent structural unit B1) and a structure containing one or more of these. The aromatic amine structure is preferably a triarylamine structure, and more preferably a triphenylamine structure. The structural unit B2 may have the same structure as the structural unit L described later, or may have a different structure.

Specific examples of the structural unit B2 include the following. However, the structural unit B2 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 described later.

(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. For example, the structural unit L is a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, biphenylene structure, terphenylene structure, spirobifluorene derivative 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 It is selected from one or structure comprising two or more al. The aromatic amine structure is preferably an aniline structure or a triarylamine structure, and the triarylamine structure is more preferably a triphenylamine structure. Of the benzene structures, a p-phenylene structure and an m-phenylene structure are preferable.

In one embodiment, the structural unit L is a group consisting of a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, bithiophene structure, benzene structure, and fluorene structure from the viewpoint of obtaining excellent hole transport properties. Is preferably selected from. In one embodiment, the structural unit L is more preferably selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, and a structure including one or more of these.
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.

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 ~
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. Ar is preferably an arylene group, more preferably a phenylene group. 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 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. 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 another embodiment, as will be described later, when the charge transporting polymer has a polymerizable functional group at the terminal portion, the structural unit T has a polymerizable structure (that is, polymerizable such as a pyrrole-yl group). Functional group). The structural unit T may have the same structure as the structural units L and / or B2, or may have a different structure.

Specific examples of the structural unit T include the following. However, 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.

(Polymerizable functional group)
In one embodiment, from the viewpoint of curing by a polymerization reaction and changing the solubility in a solvent, the charge transporting polymer preferably has at least one polymerizable functional group in the molecule. 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. 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.

  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. The polymerizable functional group may be introduced into the main chain of the charge transporting polymer, may be introduced into the side chain, or may be introduced into both the main chain and the side chain.

  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 hindering the charge transporting property, it is preferable that the amount contained in the charge transporting 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.

(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. 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. 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 B contained in the charge transporting polymer is preferably 1 mol% or more, more preferably 5 mol% or more, more preferably 10 mol%, based on the total structural unit, from the viewpoint of improving the durability of the organic electronics element. The above 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 trivalent structural unit B1 having a spirobifluorene derivative skeleton and the other trivalent or higher structural unit B2 having any other charge transporting property.

  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.

  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 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.

  In consideration of the balance of charge transportability, durability, productivity, and the like, the charge transportable polymer preferably includes a structural unit L and a structural unit T in addition to the structural unit B. In one embodiment, the ratio (molar ratio) of structural units is preferably L: T: B = 100: 10 to 200: 10 to 100, more preferably 100: 20 to 180: 20 to 90, and 100: 40 to 160: 30-80 is more preferable.

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.

(Method for producing charge transporting polymer)
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.

(Raw material monomer compound)
Although not particularly limited, an example of a combination of raw material monomers that can be used when a charge transporting polymer is prepared using the Suzuki coupling reaction is shown. In the example of the monomer (L), R is the same as R described above for the structural unit L.

[Dopant]
When an organic electronic element is constituted using a charge transporting material, the charge transporting material may further contain an additive known as an organic electronic material. In one embodiment, the charge transport material may further contain a dopant. The dopant is not particularly limited as long as it can be added to the charge transporting material to develop a doping effect and improve the charge transporting 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 for the charge transporting 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, HN
Inorganic acids such as O ₅ , H ₂ SO ₄ , HClO ₄ , benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, polyvinylsulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, 1-butane Organic acids such as sulfonic acid, vinyl phenyl sulfonic acid, camphor sulfonic acid; transition metal compounds include FeOCl, TiCl ₄ , ZrCl ₄ , HfCl ₄ , NbF ₅ , AlCl ₃ , NbCl ₅ , TaCl ₅ , MoF ₅ ; ionic compounds the tetrakis (pentafluorophenyl) borate ion, tris (trifluoromethanesulfonyl) Mechidoion, bis (trifluoromethanesulfonyl) imide ion, hexafluoroantimonate ion, AsF 6 _- ^{(hexafluoroarsenate} ion ), BF 4 _- ^{(tetrafluoroborate),} PF 6 _- ^(salt having a perfluoroalkyl anions of hexafluorophosphate) and the like, such as salts with conjugate base of the protonic acid as anion; halogen compounds, Cl ₂ , Br ₂ , I ₂ , ICl, ICl ₃ , IBr, IF, etc .; π-conjugated compounds include TCNE (tetracyanoethylene),
Examples include TCNQ (tetracyanoquinodimethane). 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 charge transporting material may further contain a charge transporting low molecular weight compound, other polymers, 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 more preferably 80% by weight or more based on the total weight of the charge transporting material from the viewpoint of obtaining good charge transporting properties. Further preferred. It may be 100% by mass.

  When the dopant is contained, the content thereof is preferably 0.01% by mass or more, and 0.1% by mass with respect to the total mass of the charge transporting material, from the viewpoint of improving the charge transporting property of the charge transporting material. The above is more preferable, and 0.5% by mass or more is still more preferable. Further, from the viewpoint of maintaining good film formability, the content is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less with respect to the total mass of the charge transporting material.

<Ink composition>
The ink composition of this embodiment contains the charge transport 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>
An organic layer is a layer contained in the organic electronics element or organic EL element of one Embodiment mentioned later, and is a layer formed using the charge transport 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 of the present embodiment has at least the organic layer of the above-described embodiment. Examples of the organic electronics element include an organic EL element, 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.

[Organic EL device]
The organic EL element of this embodiment has at least 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.

  Fluorescent materials such as perylene, coumarin, rubrene, quinacdrine, stilbene, dyes for dye lasers, aluminum complexes, and derivatives thereof; polyfluorene, polyphenylene, polyphenylene vinylene, polyvinylcarbazole, 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 are polymers such as the charge transport material of the above embodiment, polyvinylcarbazole, polyphenylene, polyfluorene, derivatives thereof, and the like. Can be mentioned.

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

[Electron transport layer, electron injection layer]
Examples of materials used for the electron transport layer and the electron injection layer include condensed ring tetracarboxylic acid anhydrides such as phenanthroline derivatives, bipyridine derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, spirobifluorene derivatives, and perylene. Products, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, thiadiazole derivatives, benzimidazole derivatives, quinoxaline derivatives, aluminum complexes, and the like. In addition, the charge transport material of the above 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, and a complementary color relationship such as blue and yellow, yellow green and orange, etc. are used. A combination containing two emission maximum wavelengths can be 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 of this embodiment includes the organic EL element of the above 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 of this embodiment is provided with the organic EL element of this embodiment. Furthermore, the display device of this embodiment includes a lighting device and a liquid crystal element as a display unit. For example, the display device can be a display device that uses the illumination device of the present embodiment as a backlight and uses a known liquid crystal element as a display unit, that is, a liquid crystal display device.

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

<1> Preparation of charge transporting polymer (Preparation of Pd catalyst)
In a glove box under a nitrogen atmosphere, tris (dibenzylideneacetone) dipalladium (73.2 mg, 80 μmol) was weighed into a sample tube at room temperature, 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, toluene (5 mL) was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at room temperature for 30 minutes to obtain a catalyst solution. In preparing the catalyst, all solvents were used after degassing with nitrogen bubbles for 30 minutes or more.

(Preparation Example 1) Charge transporting polymer 1
In a three-necked round bottom flask, the following monomer 1-1 (1.0 mmol), the following monomer 1-2 (3.0 mmol), the following monomer 2 (5.0 mmol), the following monomer 3 (2.0 mmol), a KOH aqueous solution (3M) (20 mL), trioctylmethylammonium chloride (0.1 mL) and toluene (20 mL) were added, and a separately prepared Pd catalyst solution (7.5 mL) was further added and stirred. After stirring for 30 minutes, was added to the flask. The mixture was heated to reflux for 2 hours. All the operations so far were performed under a nitrogen stream. All the solvents were used after deaeration with nitrogen bubbles for 30 minutes or more.

After completion of the reaction, the organic layer was washed with water. The organic layer was then poured into methanol-water (9: 1). The resulting precipitate was suction filtered and washed with methanol-water (9: 1). The washed precipitate was dissolved in toluene and reprecipitated from methanol. The obtained precipitate was filtered by suction, and then the process of heating and stirring in butyl acetate (60 ml) at 60 ° C. and filtration was repeated 3 times to remove low molecular weight substances. It melt | dissolved in toluene (30 ml), Si-thiol (made by Biotage) added the double weight of the polymer after low molecular weight removal, and it heated and refluxed at 120 degreeC for 2 hours.
After completion of the stirring, Si-thiol and insoluble matter were removed by filtration, reprecipitation was performed in methanol, and the obtained solid was vacuum-dried to prepare a charge transporting polymer 1.
The number average molecular weight of the obtained charge transporting polymer 1 was 7,800, and the weight average molecular weight was 31,000. The molecular weight was measured by GPC (polystyrene conversion) using THF as an eluent. The charge transporting polymer 1 includes a trivalent or higher valent structural unit B2 (derived from the monomer 3), a divalent structural unit L (derived from the monomer 2), and a polymerizable functional group that do not include a spirobifluorene derivative skeleton. The proportion of each structural unit was 18.2%, 45.5%, and 36.4% in order.

The measurement conditions of the number average molecular weight and the weight average molecular weight are as follows.
Liquid feed pump: L-6050 Hitachi High-Technologies Corporation
UV-Vis detector: L-3000 Hitachi High-Technologies Corporation Column: Gelpack ^(R) GL-A160S / GL-A150S Hitachi Chemical Co., Ltd.
Eluent: THF (manufactured by Wako Pure Chemical Industries, HPLC, without stabilizer)
Flow rate: 1 mL / min
Column temperature: Room temperature Molecular weight standard: Standard polystyrene

(Preparation Example 2) Charge transporting polymer 2
In a three-neck round bottom flask, monomer 1-1 (1.0 mmol), monomer 1-2 (3.0 mmol), monomer 2 (5.0 mmol) described in Preparation Example 1 and monomer 4 (2.0 mmol) described below And toluene (20 mL) were added, and a separately prepared Pd catalyst solution (7.5 mL) was added and stirred. Thereafter, the charge transporting polymer 2 was prepared in the same manner as described in Preparation Example 1.
The number average molecular weight of the obtained charge transporting polymer 2 was 8,800, and the weight average molecular weight was 32,000. The charge transporting polymer 2 includes a trivalent structural unit B1 (derived from the monomer 4) including a spirobifluorene derivative skeleton, a divalent structural unit L (derived from the monomer 2), and a monovalent structural unit T ( The ratio of each structural unit was 19.8%, 42.5%, and 37.7% in this order.

(Preparation Example 3) Charge transporting polymer 3
In a three-necked round bottom flask, monomer 1-1 (1.0 mmol), monomer 1-2 (3.0 mmol), monomer 2 (5.0 mmol) described in Preparation Example 1 and monomer 5 (2.0 mmol) described below were prepared. And toluene (20 mL) were added, and a separately prepared Pd catalyst solution (7.5 mL) was added and stirred. Thereafter, the charge transporting polymer 3 was prepared in the same manner as described in Preparation Example 1.
The number average molecular weight of the obtained charge transporting polymer 2 was 7,300, and the weight average molecular weight was 29,000. The charge transporting polymer 3 includes a trivalent structural unit B1 (derived from the monomer 5) including a spirobifluorene derivative skeleton, a divalent structural unit L (derived from the monomer 2), and a monovalent structural unit T ( The ratio of each structural unit was 21.5%, 39.2%, and 39.3% in order.

<2-1> Preparation of organic EL element (Comparative Example 1)
An ink composition comprising the charge transporting polymer 1 (10.0 mg) obtained in Preparation Example 1, the following ionic compound (I) (0.5 mg), and toluene (2.3 mL) was prepared. Next, the above ink composition was spin-coated at 3000 min ⁻¹ on a glass substrate (film thickness 0.7 mm) obtained by patterning ITO with a width of 1.6 mm in a nitrogen atmosphere, and subsequently, 200 ° C. on a hot plate. It was cured by heating for 10 minutes to form a hole injection layer (30 nm).

The glass substrate / hole injection layer sample obtained as described above was transferred into a vacuum evaporator, and αNPD (20 nm), CBP: Ir (ppy) ₃ (94: 6, 30 nm) was formed on the hole injection layer. ), BAlq (10 nm), Alq ₃ (30 nm), LiF (0.8 nm), and Al (100 nm) in this order, film formation by vapor deposition is carried out, so that a hole transport layer, a light emitting layer, a hole blocking layer are formed. , An electron transport layer, an electron injection layer, and a cathode were sequentially laminated. After forming the cathode by vapor deposition of Al, the laminate was moved into a dry nitrogen environment without opening to the atmosphere, and the laminate and the laminated glass containing 0.4 mm counterbore in 0.7 mm non-alkali glass The ITO glass substrate of the body was sealed using a photocurable epoxy resin to perform sealing, and an organic EL element was produced.

Example 1
An organic EL device was produced in the same manner as in Comparative Example 1 except that the charge transporting polymer 2 was used in place of the charge transporting polymer 1 in Comparative Example 1.

(Example 2)
An organic EL device was produced in the same manner as in Comparative Example 1 except that the charge transporting polymer 3 was used in place of the charge transporting polymer 1 in Comparative Example 1.

(Comparative Example 2)
A PEDOT: PSS dispersion liquid (AI4083 LVW142, manufactured by Stark Vitec Co., Ltd.) was spin-coated at a rotation speed of 1500 min ⁻¹ on a glass substrate patterned with ITO in a width of 1.6 mm. The hole injection layer (40 nm) was formed by heat-drying at ° C./10 minutes. Subsequent experiments were performed in a dry nitrogen environment.

Next, an ink composition comprising charge transporting polymer 1 (20 mg), ionic compound (I) (1.0 mg), and toluene (2.3 mL) was prepared, and the hole injection layer formed earlier was prepared. Was spin-coated at 3000 min ⁻¹ . Subsequently, the film was dried by heating at 230 ° C. for 30 minutes on a hot plate to form a hole transport layer (40 nm). Subsequently, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode were formed on the hole transport layer in the same manner as in Comparative Example 1 to produce an organic EL device.

(Example 3)
An organic EL device was produced in the same manner as in Comparative Example 2 except that the charge transporting polymer 2 was used in place of the charge transporting polymer 1 in Comparative Example 2.

Example 4
An organic EL device was produced in the same manner as in Comparative Example 2 except that the charge transporting polymer 3 was used in place of the charge transporting polymer 1 in Comparative Example 2.

<2-2> Evaluation of organic EL element When a voltage was applied to the organic EL elements obtained in Examples 1 to 4 and Comparative Examples 1 and 2, green light emission was confirmed. For each element, to measure the emission luminance 1000 cd / ^{m 2} at a driving voltage and light emission efficiency, and initial luminance of 3000 cd / ^{m 2} in the emission lifetime (luminance half-life). The measurement results are shown in Table 2.

  As can be seen from Table 2, the organic EL elements of Examples 1 to 4 exhibited a longer emission lifetime than Comparative Examples 1 and 2. That is, from the viewpoint of constituent materials of the hole injection layer and the hole transport layer, the charge transport material having a specific branched structure derived from a trivalent structural unit having a spirobifluorene derivative skeleton as the charge transport material. It has been found that the light emission lifetime is improved by using a conductive polymer.

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 8 Substrate

Claims (13)

A charge transporting material comprising a charge transporting polymer having a structure branched in three or more directions, wherein the charge transporting polymer has a spirobifluorene derivative skeleton represented by the following formula (1) or (2) A charge transporting material comprising a trivalent structural unit.

(In Formula (1) and (2), R < ₁ > -R < ₁₈ > is respectively independently a hydrogen atom, a C1-C22 linear, cyclic or branched alkyl group, alkenyl group, alkynyl group. And at least one selected from the group consisting of an aryl group and a heteroaryl group having 2 to 30 carbon atoms which may have a substituent.   The charge transporting polymer further includes a divalent structural unit having charge transporting property, and the divalent structural unit is a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, bithiophene structure, The charge transport material according to claim 1, which is selected from the group consisting of a benzene structure and a fluorene structure.   The charge transport material according to claim 2, wherein the aromatic amine structure includes a triphenylamine structure or an aniline structure.   The charge transporting polymer includes a partial structure in which three of the divalent structural units are bonded to one of the trivalent structural units having the spirobifluorene derivative skeleton. Charge transport material.   The charge transport material according to any one of claims 1 to 4, which is used as a hole transport material.   An ink composition comprising the charge transporting material according to claim 1 and a solvent.   The organic electronics element which has an organic layer containing the electric charge transport material of any one of Claims 1-5.   The organic electroluminescent element which has an organic layer containing the electric charge transport material of any one of Claims 1-5.   The organic electroluminescent element according to claim 8, further comprising a flexible substrate.   The organic electroluminescent element according to claim 9, wherein the flexible substrate includes a resin film.   The display element provided with the organic electroluminescent element of any one of Claims 8-10.   The illuminating device provided with the organic electroluminescent element of any one of Claims 8-10.   A display device comprising the illumination device according to claim 12 and a liquid crystal element as display means.

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