WO2018020571A1 - Organic electronics material - Google Patents

Abstract

Provided is an organic electronics material for an organic electroluminescence element having excellent heat resistance and service life characteristics. An organic electronics material containing a charge-transporting polymer that includes: a structural unit that is trivalent or greater and has a 9-phenylcarbazole structure; and a structural unit having a triphenylamine structure in which at least one phenyl group has an alkoxy group.

Description

Organic electronics materials

Embodiments of the present invention relate to an organic electronic material and an organic thin film using the material. Moreover, other embodiment of this invention is related with the organic electronics element and organic electroluminescent element containing the said organic thin film, and the display element, illuminating device, and display apparatus using these.

An organic electronics element is an element that performs an electrical operation using an organic substance, and is expected to exhibit features such as energy saving, low cost, and flexibility. Therefore, it attracts attention as a technology that replaces the conventional inorganic semiconductor mainly composed of silicon.
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 electronics elements, organic EL elements are attracting attention as applications for large-area solid-state light sources that can replace, for example, incandescent lamps or gas-filled lamps. 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 low molecular organic EL elements and polymer organic EL elements, depending on the organic materials used. In the polymer organic EL element, a polymer compound is used as an organic material, and in the low molecular organic EL element, a low molecular compound is used. On the other hand, the manufacturing method of the organic EL element includes 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 relief printing and intaglio printing, and plateless printing such as inkjet. It is roughly divided into The wet process is expected to be an indispensable method for realizing a large-screen organic EL display in the future because simple film formation is possible.

Therefore, in recent years, materials suitable for wet processes have been developed. For example, studies have been conducted to produce a multilayer organic EL device using a polymer compound having a polymerizable functional group (see, for example, Patent Document 1 and Non-Patent Document 1).

JP 2006-279007 A

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

An organic EL device manufactured using a polymer compound according to a wet process has a feature that it is easy to reduce the cost and increase the area. However, organic EL devices manufactured using conventional polymer compounds are desired to be further improved in various characteristics of the organic EL elements such as driving voltage, light emission efficiency, and lifetime characteristics. In order to improve various characteristics of the organic EL device, it is desirable that the polymer compound has an excellent charge transport property and an excellent thermal stability.

However, conventional polymer compounds used in organic EL devices often have insufficient thermal stability (heat resistance). Therefore, a conventional organic thin film made of a polymer compound is likely to be deteriorated by heat during a high-temperature processing process and driving an organic EL element. Accompanying such a heat resistance problem, an organic EL element that is not yet satisfactory in terms of lifetime characteristics has not been obtained, and further improvement is desired.

In view of the above, an embodiment of the present invention aims to provide an organic electronic material including a polymer compound having excellent charge transportability and excellent heat resistance, and an organic thin film using the material. And In addition, another embodiment of the present invention provides an organic electronics element and an organic EL element that are excellent in heat resistance and life characteristics, including the organic thin film, and a display element, an illuminating device, and a display device using the same. The purpose is to do.

As a result of intensive studies on a polymer compound having a charge transporting property, the present inventors have at least a 9-phenylcarbazole structure and a triphenylamine structure in which at least one phenyl group has an alkoxy group, and the above 9 It has been found that a specific charge transporting polymer having a structure branched from a phenylcarbazole structure in three or more directions has excellent heat resistance and can be suitably used as an organic electronic material. Furthermore, the present inventors have found that an organic electronic material containing the specific charge transporting polymer is effective in improving the heat resistance and life characteristics of the organic EL element, and has completed the present invention. That is, the embodiment of the present invention relates to the following.

Embodiments of the present invention relate to organic electronic materials. The organic electronic material contains a charge transporting polymer including a trivalent or higher valent structural unit having a 9-phenylcarbazole structure and a structural unit having a triphenylamine structure in which at least one phenyl group has an alkoxy group. It is characterized by.
In the organic electronic material, the charge transporting polymer preferably has a polymerizable functional group.
The organic electronic material preferably further contains a dopant. The dopant preferably contains an onium salt.

Other embodiment of this invention is related with the organic thin film formed using the organic electronics material of the said embodiment.

Another embodiment of the present invention relates to an organic electronic device including at least one of the organic thin films of the above embodiment.

Other embodiment of this invention is related with the organic electroluminescent element containing at least 1 of the organic thin film of the said embodiment. The organic thin film of the above embodiment is preferably at least one of a hole injection layer and a hole transport layer.
The organic electroluminescence element preferably further includes a flexible substrate or further includes a resin film substrate.

Other embodiment of this invention is related with the display element provided with the organic electroluminescent element of the said embodiment.

Other embodiment of this invention is related with the illuminating device provided with the organic electroluminescent element of the said embodiment.

Another embodiment of the present invention relates to a display device including the illumination device of the above embodiment and a liquid crystal element as a display means.

According to the embodiment of the present invention, it is possible to provide an organic electronic material having excellent charge transportability and heat resistance, and an organic thin film using the material. Moreover, according to other embodiment of this invention, the organic electronics element excellent in heat resistance and lifetime characteristics including the organic thin film formed using the organic electronics material, an organic EL element, and a display using the same An element, a lighting device, and a display device can be provided.

FIG. 1 is a schematic diagram showing an example of an organic EL element according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an example of an organic EL element according to an embodiment of the present invention. FIG. 3 is a graph of voltage-current density curves when a voltage is applied to each hole-only device obtained in Examples 1 to 4 and Comparative Examples 1 to 4.

Hereinafter, embodiments of the present invention will be described in detail.
<Organic electronics materials>
The organic electronic material that is an embodiment of the present invention contains one or more charge transporting polymers having the ability to transport charges. The organic electronic material includes at least a charge transporting polymer having a structure branched in three or more directions, and the polymer includes at least a trivalent or higher valent structural unit (1) having a 9-phenylcarbazole structure and a nitrogen atom. And a structural unit (2) having a triphenylamine structure, wherein one phenyl group has at least one alkoxy group.
Since the charge transporting polymer has excellent charge transporting ability and excellent heat resistance, the use of them makes it possible to easily improve various device characteristics including the light emission lifetime. The organic electronic material may contain two or more of the specific charge transporting polymers, or may further contain other charge transporting polymers.

[Charge transporting polymer]
The charge transporting polymer having a structure branched in three or more directions includes a trivalent or higher structural unit B including a trivalent or higher structural unit (1) having a 9-phenylcarbazole structure and a monovalent constituting a terminal portion. And a divalent structural unit L having a charge transporting property may be included. Preferably, the specific charge transporting polymer includes a trivalent or higher structural unit B including at least the structural unit (1), a divalent structural unit L, and a monovalent structural unit T. In the charge transporting polymer, the structural unit (2) having the triphenylamine structure is included in at least one of the structural units B, L, and T. The structural unit (2) is preferably contained in at least one of the structural units L and T.

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

(Construction)
Examples of the partial structure contained in the charge transporting polymer having a structure branched in three or more directions include the following. The charge transporting polymer is not limited to a polymer having the following partial structure. 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, a plurality of L may be the same structural unit or different structural units. The same applies to “T” and “B”.

Charge transporting polymer

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

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

W represents a trivalent linking group, for example, an arenetriyl group or a heteroarenetriyl group having 2 to 30 carbon atoms. The arenetriyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic hydrocarbon. The 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 one or more substituents R. The substituents R each independently include —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 groups. R ¹ to R ⁸ each independently represents a hydrogen atom; a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms; or an aryl group or heteroaryl group having 2 to 30 carbon atoms (provided that Except when R ¹ is a hydrogen atom).
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 with an aryl group or heteroaryl group having 2 to 20 carbon atoms, and the aryl group or heteroaryl group may be further linear, cyclic or branched having 1 to 22 carbon atoms. It may be substituted with an alkyl group.
R is preferably an alkyl group, an aryl group, or an alkyl-substituted aryl 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 B1)
The charge transporting polymer used in the organic electronic material according to the embodiment of the present invention may optionally contain the trivalent or higher structural unit B constituting the branched portion described above, but has at least a 9-phenylcarbazole structure. And a trivalent or higher structural unit (1). Hereinafter, the trivalent or higher structural unit (1) is also referred to as a structural unit B1.
The 9-phenylcarbazole structure means a structure in which a hydrogen moiety on the nitrogen atom of 9H-carbazole is substituted with a phenyl group. Therefore, the structural unit B1 intends a structure having the 9-phenylcarbazole structure and having three or more linking groups that can be bonded to other structures. The phenyl group bonded to the nitrogen atom may have a substituent or a linking group, and the substituents may be linked to form a cyclic structure. The aromatic ring forming the carbazole skeleton may also have a substituent or a linking group.

When the charge transporting polymer contains a trivalent or higher structural unit B1 having a 9-phenylcarbazole structure in the molecule, it becomes easy to improve the light emission efficiency of the organic EL device. Although details are unknown, it is considered that the charge transporting polymer containing the structural unit B1 in the molecule is caused by a high triplet (T1) level.

Specific examples of the structural unit B1 include the following.

Preferred specific examples of the structural unit B1 include the following.

In the structural units (B1-a) and (B1-a ′), l is an integer of 0 to 4, m and n are each independently an integer of 0 to 3, and the number of substituents R is Show. In the structural units (B1-b) and (B1-b ′), l and m are each independently an integer of 0 to 3, n is an integer of 0 to 4, and each represents the number of substituents R. Indicates. In each of the structural units, “*” represents a binding site with another structure.
The substituents R each independently include —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 groups. R ¹ to R ⁸ are as described above for the structural unit B. In one embodiment, the substituent R in each structural unit is preferably a linear, cyclic, or branched alkyl group having 1 to 12 carbon atoms, or an aryl group having 2 to 12 carbon atoms. The aryl group may be further substituted with a linear, cyclic, or branched alkyl group having 1 to 12 carbon atoms.

In one embodiment of each structural unit described above, l + m + n is preferably 0 to 3, and more preferably 0 or 1. In one embodiment, the substituent R is more preferably selected from the group consisting of a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms and an aryl group having 2 to 8 carbon atoms.

More preferable specific examples of the structural unit B1 include the following. However, the structural unit B1 is not limited to the following. In each structural unit, “*” indicates a binding site with another structure.

(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, biphenyl structure, terphenyl structure, naphthalene structure, anthracene structure, tetracene structure, phenanthrene structure, dihydro Phenanthrene structure, pyridine structure, pyrazine structure, quinoline structure, isoquinoline structure, quinoxaline structure, acridine structure, diazaphenanthrene structure, furan structure, pyrrole structure, oxazole structure, oxadiazole structure, thiazole structure, thiadiazole structure, triazole structure, benzo Thiophene structure, benzoxazole structure, benzooxadiazole structure, benzothiazole structure, benzothiadiazole structure, benzotriazole structure, and one or two of these It is selected from the structure including the upper.

In one embodiment, the structural unit L includes a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, pyrrole structure, and these from the viewpoint of obtaining excellent hole transport properties. Preferably, it is selected from a structure containing one or more of these, and is selected from a substituted or unsubstituted aromatic amine structure, carbazole structure, and a structure containing one or more of these Is more preferable. Here, the aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure.

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

Each R independently represents a hydrogen atom or a substituent. Preferably, each R independently represents —R ¹ , —OR ² , —SR ³ , —OCOR ⁴ , —COOR ⁵ , —SiR ⁶ R ⁷ R ⁸ , a halogen atom, and a polymerizable functional group described later. Selected from the group consisting of containing groups. R ¹ to R ⁸ each independently represents a hydrogen atom; a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms; or an aryl group or heteroaryl group having 2 to 30 carbon atoms. The aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. A heteroaryl group is an atomic group obtained by removing one hydrogen atom from an aromatic heterocyclic ring. The alkyl group may be further substituted with an aryl group or heteroaryl group having 2 to 20 carbon atoms, and the aryl group or heteroaryl group may be further linear, cyclic or branched having 1 to 22 carbon atoms. It may be substituted with an alkyl group. R is preferably a hydrogen atom, an alkyl group, an aryl group, or an alkyl-substituted aryl group. Ar represents an arylene group or heteroarylene group having 2 to 30 carbon atoms. An arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon. A heteroarylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic heterocycle. Ar is preferably an arylene group, more preferably a phenylene group.

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

(Structural unit L1)
The charge transporting polymer used in the organic electronic material according to the embodiment of the present invention may optionally include the above-described divalent structural unit L. However, in one embodiment, at least one phenyl group is an alkoxy group. And a divalent structural unit (2) having a triphenylamine structure. Hereinafter, the divalent structural unit (2) is also referred to as a structural unit L1.
In the structural unit L1, the triphenylamine structure means that at least one phenyl group bonded to a nitrogen atom has a structure having at least one alkoxy group. The phenyl group may have a substituent other than an alkoxy group or a linking group, and the substituents may be linked to form a cyclic structure. That is, the structural unit L1 intends a structure in which two linking groups are bonded to a triphenylamine structure in which at least one phenyl group has an alkoxy group.

When the charge transporting polymer contains the structural unit L1 in the molecule, it is easy to improve the light emission lifetime of the organic EL element. Although details are unknown, in the triphenylamine structure, when an alkoxy group is introduced into at least one phenyl group, the heat resistance is easily improved. Therefore, by using a charge transporting polymer containing a structural unit having such a specific triphenylamine structure, the heat resistance of the polymer is improved and the deterioration of the organic thin film is suppressed, so that the organic EL device emits light. It is thought that it contributes to the improvement of life.

Specific examples of the structural unit L1 include the following.

Preferred specific examples of the structural unit L1 include the following.

In the structural units (L1-a) and (L1-a ′), l is an integer of 0 to 5, m and n are each independently an integer of 0 to 4, and the number of substituents R is Indicates. In the structural unit, “*” indicates a binding site with another structure.

In the structural unit, l + n + m is 1 or more, and at least one substituent R is an alkoxy group (—OR). The alkoxy group is intended to be a group in which an alkyl group having 1 to 8 carbon atoms is bonded to an oxygen atom. In one embodiment, the alkoxy group is preferably a group in which a linear or branched alkyl group having 1 to 8 carbon atoms is bonded to an oxygen atom.
In the structural unit, at least one phenyl group bonded to the nitrogen atom may have a substituent R other than the alkoxy group (—OR). Substituents R other than the alkoxy group include, for example, —R ¹ , —OR ² , —SR ³ , —OCOR ⁴ , —COOR ⁵ , —SiR ⁶ R ⁷ R ⁸ , a halogen atom, and a polymerizable function described later. Selected from the group consisting of groups containing groups. Here, R ¹ to R ⁸ are as described above for the structural unit B1. However, —OR ² does not include the alkoxy group (—OR).

More preferable specific examples of the structural unit L1 include the following. However, the structural unit L1 is not limited to the following. In each structural unit, “*” indicates a binding site with another structure.

(Structural unit T)
The structural unit T is a monovalent structural unit constituting the terminal portion of the charge transporting polymer. The structural unit T is not particularly limited, and is selected from, for example, a substituted or unsubstituted aromatic hydrocarbon structure, aromatic heterocyclic structure, and a structure including one or more of these. The structural unit T may have the same structure as the structural unit L. 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 described later, when the charge transporting polymer has a polymerizable functional group at the terminal portion, the structural unit T has a polymerizable structure (for example, a polymerizable functional group such as a pyrrol-yl group). ).

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

R is the same as R in the structural unit L. When the charge transporting polymer has a polymerizable functional group at the terminal portion, preferably at least one of R is a group containing a polymerizable functional group.

(Structural unit T1)
The charge transporting polymer used in the organic electronic material according to the embodiment of the present invention may optionally include the monovalent structural unit T shown above, but in one embodiment, the trivalent group having at least one alkoxy group. A monovalent structural unit (1) having a phenylamine structure is included. Hereinafter, the monovalent structural unit (1) is also referred to as a structural unit T1.

Specific examples of the structural unit T1 include the following.

Specific examples of the structural unit T1 include the following.

In the structural units (T1-a) and (T1-a ′), l and m are each independently an integer of 0 to 5, n is an integer of 0 to 4, and each represents the number of substituents R. Indicates. l + n + m is 1 or more, and at least one substituent R is an alkoxy group (—OR). The alkoxy group is intended to be a group in which an alkyl group having 1 to 8 carbon atoms is bonded to an oxygen atom. In the structural unit, at least one phenyl group bonded to the nitrogen atom may have a substituent R other than the alkoxy group. The alkoxy group (—OR) and the substituent R other than the alkoxy group are as described above for the divalent structural unit L1. When the structural unit T1 is included in the molecule of the charge transporting polymer, excellent heat resistance can be obtained, which makes it easy to improve the light emission lifetime of the organic EL element.

More preferable specific examples of the structural unit T1 include the following. However, the structural unit T1 is not limited to the following. In each structural unit, “*” indicates a binding site with another structure.

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

Examples of the polymerizable functional group include a group having a carbon-carbon multiple bond (for example, vinyl group, allyl group, butenyl group, ethynyl group, acryloyl group, acryloyloxy group, acryloylamino group, methacryloyl group, methacryloyloxy group, methacryloylamino group). Groups, vinyloxy groups, vinylamino groups, etc.), groups having a small ring (eg, cyclic alkyl groups such as cyclopropyl groups, cyclobutyl groups; cyclic ether groups such as epoxy groups (oxiranyl groups), oxetane groups (oxetanyl groups), etc. Diketene group; episulfide group; lactone group; lactam group, etc.), heterocyclic group (for example, furan-yl group, pyrrol-yl group, thiophen-yl group, silole-yl group) and the like. As the polymerizable functional group, a vinyl group, an acryloyl group, a methacryloyl group, an epoxy group, and an oxetane group are particularly preferable, and from the viewpoint of reactivity and characteristics of the organic electronics element, a vinyl group, an oxetane group, or an epoxy group is more preferable. preferable.

From the viewpoint of increasing the degree of freedom of the polymerizable functional group and facilitating the polymerization reaction, the main skeleton of the charge transporting polymer and the polymerizable functional group are preferably 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. When the charge transporting polymer has a branched structure, the polymerizable functional group may be introduced into the main chain of the charge transporting polymer or into the side chain, and both the main chain and the side chain may be introduced. May be introduced.

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

For example, the number of polymerizable functional groups per molecule of the charge transporting polymer is preferably 2 or more, more preferably 3 or more from the viewpoint of obtaining a sufficient 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 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.

In one embodiment, the charge transporting polymer having a structure branched in three or more directions includes at least a trivalent or higher structural unit B1 having a 9-phenylcarbazole structure as the trivalent or higher structural unit B, and the structural unit L and / or T includes structural units L1 and / or T1 having a triphenylamine structure having at least one alkoxy group.
In another embodiment, the charge transporting polymer includes at least the structural unit L1 and / or T1 as the structural unit B1 and the structural unit L and / or T.
In still another embodiment, the charge transporting polymer includes the structural unit B1, the structural unit L, and the structural unit T, and the structural unit T has at least the structural unit T1 and a polymerizable functional group. And the structural unit T.

According to the embodiment of the present invention, by using a charge transporting polymer including at least the structural unit B1, the structural unit L1, and / or the structural unit T1, the heat resistance and the emission lifetime of the organic EL element are improved. It becomes possible to do. From the viewpoint of effectively obtaining such effects, the proportion of the structural unit B1 contained in the structural unit B is preferably 50 mol% or more, more preferably 60 mol, based on the total amount of the structural unit B. % Or more, more preferably 70 mol% or more.
When the charge transporting polymer includes the structural unit L1, the structural unit L1 is preferably 50 mol% or more, more preferably 60 mol% or more, and still more preferably 70 mol% or more based on the total amount of the structural unit L. To do.
Further, when the charge transporting polymer includes the structural unit T1 as the structural unit T, the structural unit T1 is preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 50 based on the total amount of the structural unit T. More than mol%.
In particular, from the viewpoint of improving the heat resistance of the charge transporting polymer, the proportion of the structural units L1 and / or T1 is preferably 10 mol% or more, more preferably 20 mol% or more, based on the total constituent units of the polymer. 30 mol% or more is more preferable. When the charge transporting polymer includes the structural units L1 and T1, the above ratio means the total amount of L1 and T1.

(Ratio of structural units B, L, and T)
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. The said ratio means the total amount of the structural unit B including the structural unit B1.

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. When the charge transporting polymer contains the structural unit L1, the above ratio means the total amount including the structural unit L1.

The proportion of the structural unit T contained in the charge transporting polymer is based on the total structural unit from the viewpoint of improving the characteristics of the organic electronics element or suppressing the increase in the viscosity and satisfactorily synthesizing the charge transporting polymer. 5 mol% or more is preferable, 10 mol% or more is more preferable, and 15 mol% or more is still more preferable. The proportion of the structural unit T is preferably 60 mol% or less, more preferably 55 mol% or less, and still more preferably 50 mol% or less from the viewpoint of obtaining sufficient charge transport properties. When the charge transporting polymer contains the structural unit T1, the above ratio means the total amount including the structural unit T1.

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

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

(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.

(Production method)
The charge transporting polymer can be produced by various synthetic methods and is not particularly limited. For example, known coupling reactions such as Suzuki coupling, Negishi coupling, Sonogashira coupling, Stille coupling, Buchwald-Hartwig coupling and the like can be used. Suzuki coupling causes a cross coupling reaction using a Pd catalyst between an aromatic boronic acid derivative and an aromatic halide. According to Suzuki coupling, a charge transporting polymer can be easily produced by bonding desired aromatic rings together.

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

[Dopant]
The organic electronic material may further contain a dopant. The dopant is not particularly limited as long as it is a compound that can be added to the organic electronic material to develop a doping effect and improve the charge transport property. Doping includes p-type doping and n-type doping. In p-type doping, a substance serving as an electron acceptor is used as a dopant, and in n-type doping, a substance serving as an electron donor is used as a dopant. It is preferable to perform p-type doping for improving hole transportability and n-type doping for improving electron transportability. The dopant used in the organic electronic material may be a dopant that exhibits any effect of p-type doping or n-type doping. Further, one kind of dopant may be added alone, or plural kinds of dopants may be mixed and added.

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

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

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

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

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

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

<Ink composition>
In one embodiment, the organic electronic material may further contain a solvent capable of dissolving or dispersing the material to constitute an ink composition. The ink composition contains at least the organic electronic material of the above embodiment and a solvent capable of dissolving or dispersing the material. The ink composition may contain various known additives as required, as long as the characteristics of the organic electronic material are not deteriorated. By using such an 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 and 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 thin film (organic layer)>
The organic layer which is embodiment of this invention is a layer formed using the organic electronics material or ink composition of the said embodiment. By using the ink composition, the organic layer can be favorably formed by a coating method.
Therefore, an example of the method for producing an organic layer that is an embodiment of the present invention includes a step of applying an ink composition. 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.
The manufacturing method includes any steps such as drying the organic layer (that is, the coating layer) obtained after coating using a hot plate or an oven, removing the solvent, and curing the coating layer. Further, it may be included.

When the charge transporting polymer has a polymerizable functional group, the solubility of the organic layer can be changed by proceeding 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 charge transport efficiency, the thickness of the organic layer after drying or curing is preferably 0.1 nm or more, more preferably 1 nm or more, and further preferably 3 nm or more. In addition, the thickness of the organic layer is preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 100 nm or less, from the viewpoint of reducing electrical resistance.

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

[Organic EL device]
The organic EL element which is embodiment of this invention has an organic layer of the said embodiment at least. 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. In one embodiment, the organic layer can be formed satisfactorily according to a coating method using the ink composition described above.

FIG.1 and FIG.2 is a cross-sectional schematic diagram which shows one Embodiment of an organic EL element, respectively. The organic EL element shown in FIG. 1 is an element having a multilayer structure, and has an anode 1, a hole injection layer 2, a light emitting layer 3, an electron injection layer 4, and a cathode 5 in this order on a substrate 6. . In one embodiment, the hole injection layer 2 is composed of an organic layer that is one embodiment of the present invention.
The organic EL element shown in FIG. 2 is an element having a multilayer structure. On the substrate 6, the anode 1, the hole injection layer 2, the hole transport layer 7, the light emitting layer 3, the electron transport layer 8, and the electron injection layer 4 are provided. And the cathode 5 in this order. In one embodiment, at least one of the hole injection layer 2 and the hole transport layer 7 is composed of an organic layer that is an embodiment of the present invention. 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, and mixtures thereof.

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), and 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.

In the case where 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 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. Examples of the polymer include the organic electronic materials, polyvinyl carbazole, polyphenylene, polyfluorene, derivatives thereof, and the like of the above embodiment. It is done.

Examples of thermally activated delayed fluorescent materials include Adv.AMater., 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.

[Hole transport layer, hole injection layer]
As a material constituting the hole transport layer and the hole injection layer, an organic electronic material which is an embodiment of the present invention can be given. In one embodiment, at least one of the hole injection layer and the hole transport layer is preferably composed of an organic electronic material that is an embodiment of the present invention.
As a material constituting the hole transport layer and the hole injection layer, a material containing a polymer different from the charge transport polymer contained in the organic electronics material according to the embodiment of the present invention can be used. For example, an organic electronic material containing a charge transporting polymer including a trivalent or higher valent structural unit having a 9-phenylcarbazole structure and a structural unit having a triphenylamine structure having no alkoxy group as a substituent for the phenyl group. It can also be used. In addition, a known material can also be used.

Known materials that can be used for the hole injection layer and the hole transport layer include, for example, (aromatic amine compounds (for example, N, N′-di (naphthalen-1-yl) -N, N′-diphenyl) -Aromatic diamines such as benzidine (α-NPD)), phthalocyanine compounds, thiophene compounds (eg, thiophene conductive polymers (eg, poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfone) Acid salt) (PEDOT: PSS) and the like).

In one embodiment, when the organic EL device has a hole injection layer and a hole transport layer, the hole injection layer is formed using a known material or the other organic electronic material, and the hole transport layer is formed. It is preferable to comprise from the organic layer formed using the organic electronics material which is embodiment of this invention.

[Electron transport layer, electron injection layer]
Examples of materials used for the electron transport layer and the electron injection layer include phenanthroline derivatives, bipyridine derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, condensed ring tetracarboxylic anhydrides such as naphthalene and perylene, and carbodiimides. Fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, thiadiazole derivatives, benzimidazole derivatives, quinoxaline derivatives, aluminum complexes, and the like. Moreover, the organic electronic material of the said embodiment can also be used.

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

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

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

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

In the case of using a resin film, an inorganic substance such as silicon oxide or silicon nitride may be coated on the resin film in order to suppress permeation of water vapor, oxygen and the like.

[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 a plurality of emission colors using a plurality of light emitting materials and mixing the colors can be used. The combination of a plurality of emission colors is not particularly limited, but there are a combination containing three emission maximum wavelengths of blue, green and red, and a combination containing two emission maximum wavelengths such as blue and yellow, yellow green and orange. 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 which is embodiment of this invention is equipped with the organic EL element of the said embodiment. For example, a color display element can be obtained by using an organic EL element as an element corresponding to each pixel of red, green, and blue (RGB). Image forming methods include a simple matrix type in which individual organic EL elements arranged in a panel are directly driven by electrodes arranged in a matrix, and an active matrix type in which a thin film transistor is arranged and driven in each element.

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

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

<I> Preparation of charge transporting polymer (Preparation of Pd catalyst)
Tris (dibenzylideneacene) dipalladium (73.2 mg, 80 μmol) was weighed into 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 in a sample tube, anisole (5 mL) was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at room temperature for 30 minutes, and then used as a Pd catalyst solution. All solvents were used after being degassed with nitrogen bubbles for more than 30 minutes.

(Charge transporting polymer 1)
In a three-neck round bottom flask, the following monomer B1-1 (2.0 mmol), the following monomer L1 (5.0 mmol), the following monomer T-1 (1.0 mmol), the following monomer T-2 (3.0 mmol), and anisole (20 mL) was added, and the previously prepared Pd catalyst solution (7.5 mL) was further added. After the reaction solution was stirred for 30 minutes, a 10% tetraethylammonium hydroxide aqueous solution (20 mL) was added to the reaction solution. All raw materials were used after being degassed with nitrogen bubbles for 30 minutes or more. The mixture was heated to reflux for 2 hours. The operation so far was 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 and reprecipitated from methanol. The obtained precipitate was collected by suction filtration, dissolved in toluene, and a metal adsorbent (“Triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer” manufactured by Strem Chemicals, 200 mg with respect to 100 mg of the precipitate) was added. Stir overnight. After completion of the stirring, the metal adsorbent and insoluble matter were removed by filtration, and the filtrate was concentrated with a rotary evaporator. The concentrate was dissolved in toluene and then reprecipitated from methanol-acetone (8: 3). 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 number average molecular weight of the obtained charge transporting polymer 1 was 33,700, and the weight average molecular weight was 92,000.

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

(Charge transporting polymer 2)
In a three-necked round bottom flask, the above monomer B1-1 (2.0 mmol), the following monomer L-1 (5.0 mmol), the above monomer T-1 (1.0 mmol), the following monomer T1 (3.0 mmol), and anisole (20 mL) was added, and the previously prepared Pd catalyst solution (7.5 mL) was further added. Thereafter, the charge transporting polymer 2 was synthesized in the same manner as the synthesis of the charge transporting polymer 1.
The number average molecular weight of the obtained charge transporting polymer 2 was 18,400, and the weight average molecular weight was 47,000.

(Charge transporting polymer 3)
A three-necked round bottom flask was charged with the monomer B1-1 (2.0 mmol), the monomer L1 (5.0 mmol), the monomer T-1 (1.0 mmol), the monomer T1 (3.0 mmol), and anisole (20 mL). ), And the previously prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the charge transporting polymer 3 was synthesized in the same manner as the synthesis of the charge transporting polymer 1.
The number average molecular weight of the obtained charge transporting polymer 3 was 23,600, and the weight average molecular weight was 61,200.

(Charge transporting polymer 4)
In a three-necked round bottom flask, the following monomer B1-2 (2.0 mmol), monomer L1 (5.0 mmol), monomer T-1 (1.0 mmol), monomer T-2 (3.0 mmol), and anisole (20 mL) was added, and the previously prepared Pd catalyst solution (7.5 mL) was further added. Thereafter, the charge transporting polymer 4 was synthesized in the same manner as the charge transporting polymer 1 was synthesized.
The resulting charge transporting polymer 4 had a number average molecular weight of 20,200 and a weight average molecular weight of 79,800.

(Charge transporting polymer 5)
In a three-necked round bottom flask, the monomer B1-2 (2.0 mmol), the monomer L-1 (5.0 mmol), the monomer T-1 (1.0 mmol), the monomer T1 (3.0 mmol), and anisole (20 mL) was added, and the previously prepared Pd catalyst solution (7.5 mL) was further added. Thereafter, the charge transporting polymer 5 was synthesized in the same manner as the charge transporting polymer 1 was synthesized.
The number average molecular weight of the obtained charge transporting polymer 5 was 18,400, and the weight average molecular weight was 52,700.

(Charge transporting polymer 6)
A three-necked round bottom flask was charged with the monomer B1-2 (2.0 mmol), the monomer L1 (5.0 mmol), the monomer T-1 (1.0 mmol), the monomer T1 (3.0 mmol), and anisole (20 mL). ), And the previously prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the charge transporting polymer 6 was synthesized in the same manner as the charge transporting polymer 1 was synthesized.
The number average molecular weight of the obtained charge transporting polymer 6 was 25,100, and the weight average molecular weight was 84,300.

(Charge transporting polymer 7)
In a three-necked round bottom flask, the monomer B1-1 (2.0 mmol), the monomer L-1 (5.0 mmol), the monomer T-1 (1.0 mmol), the monomer T-2 (3.0 mmol), And anisole (20 mL) were added, and the previously prepared Pd catalyst solution (7.5 mL) was further added. Thereafter, the charge transporting polymer 7 was synthesized in the same manner as the charge transporting polymer 1 was synthesized.
The number average molecular weight of the obtained charge transporting polymer 7 was 30,900, and the weight average molecular weight was 88,800.

(Charge transporting polymer 8)
In a three-necked round bottom flask, the monomer B1-2 (2.0 mmol), the monomer L-1 (5.0 mmol), the monomer T-1 (1.0 mmol), the monomer T-2 (3.0 mmol), And anisole (20 mL) were added, and the previously prepared Pd catalyst solution (7.5 mL) was further added. Thereafter, the charge transporting polymer 8 was synthesized in the same manner as the charge transporting polymer 1 was synthesized.
The number average molecular weight of the obtained charge transporting polymer 8 was 19,900, and the weight average molecular weight was 65,000.

(Charge transporting polymer 9)
In a three-necked round bottom flask, the following monomer B-1 (2.0 mmol), the above monomer L-1 (5.0 mmol), the following monomer T-3 (1.0 mmol), the above monomer T-2 (3.0 mmol), And anisole (20 mL) were added, and the previously prepared Pd catalyst solution (7.5 mL) was further added. Thereafter, the charge transporting polymer 9 was synthesized in the same manner as the charge transporting polymer 1 was synthesized.
The number average molecular weight of the obtained charge transporting polymer 9 was 39,200, and the weight average molecular weight was 75,200.

注記：
　添文字（１）は、９－フェニルカルバゾール構造を有する３価以上の構造単位に相当することを示す。
　添文字（２）は、少なくとも１つのフェニル基がアルコキシ基を有するトリフェニルアミン構造を有する構造単位に相当することを示す。
The monomers used in the preparation of charge transporting polymers 1-9 are summarized in the following table.

Note:
The subscript (1) indicates that it corresponds to a trivalent or higher structural unit having a 9-phenylcarbazole structure.
The subscript (2) indicates that at least one phenyl group corresponds to a structural unit having a triphenylamine structure having an alkoxy group.

<II> Fabrication and evaluation of hole-only device (heat resistance evaluation of charge transporting polymer)
Using each of the charge transporting polymers prepared above, a hole-only device was produced as follows, and the heat resistance was evaluated from the current density characteristics.

Example 1
Under a nitrogen atmosphere, charge transporting polymer 1 (50.0 mg), the following dopant 1 (2.5 mg), and toluene (1.36 mL) were mixed to prepare an ink composition. An ink composition was spin-coated on a glass substrate patterned with ITO to a width of 1.6 mm at a rotation speed of 3,000 min ⁻¹ , and then the coating film was cured by heating at 180 ° C. for 10 minutes on a hot plate. A hole injection layer (150 nm) was formed.
The glass substrate having the hole injection layer was transferred into a vacuum vapor deposition machine, and Al (150 nm) was deposited on the hole injection layer by a vapor deposition method. Then, the sealing process was performed and the hole only device was produced.

(Example 2)
A hole-only device was fabricated in the same manner as in Example 1, except that the heating conditions on the hot plate were changed to 230 ° C. for 30 minutes in the hole injection layer forming step in the hole-only device of Example 1.

(Example 3)
A hole-only device was produced in the same manner as in Example 1 except that the charge transporting polymer 1 was changed to the charge transporting polymer 2 in the hole injection layer forming step in the hole-only device of Example 1.

(Example 4)
A hole-only device was fabricated in the same manner as in Example 3 except that in the hole injection layer forming step of the hole-only device of Example 3, the heating conditions on the hot plate were changed to 230 ° C. for 30 minutes.

(Comparative Example 1)
A hole-only device was produced in the same manner as in Example 1 except that the charge transporting polymer 1 was changed to the charge transporting polymer 9 in the hole injection layer forming step in the hole-only device of Example 1.

(Comparative Example 2)
A hole-only device was fabricated in the same manner as in Comparative Example 1 except that the heating conditions on the hot plate were changed to 230 ° C. for 30 minutes in the hole injection layer forming step in the hole-only device of Comparative Example 1.

(Comparative Example 3)
A hole-only device was produced in the same manner as in Example 1 except that the charge transporting polymer 1 was changed to the charge transporting polymer 8 in the hole injection layer forming step in the hole-only device of Example 1.

(Comparative Example 4)
A hole-only device was fabricated in the same manner as in Comparative Example 3, except that the heating conditions on the hot plate were changed to 230 ° C. for 30 minutes in the hole injection layer forming step in the hole-only device of Comparative Example 3.

Table 2 summarizes the materials and heating conditions used for forming the hole injection layers of the hole-only devices in Examples 1 to 4 and Comparative Examples 1 to 4 described above.

FIG. 3 shows a graph of voltage-current density curves when a voltage is applied to each hole-only device obtained in Examples 1 to 4 and Comparative Examples 1 to 4.
As is clear from the graph shown in FIG. 3, the heating conditions during the formation of the hole injection layer are more severe (that is, higher temperature and longer heating time) than Comparative Examples 1 and 3, and In 4, the drive voltage is significantly increased. Here, the drive voltage means a voltage necessary for obtaining a constant current density. On the other hand, the increase in drive voltage in Examples 2 and 4 in which the heating conditions during the formation of the hole injection layer are more severe than those in Examples 1 and 3 are slight.
Generally, when the heat resistance of a polymer is low, the organic thin film deteriorates due to the thermal history, and the driving voltage of the organic EL element tends to increase. From such a viewpoint, as is clear from the comparison between Examples 1 to 4 and Comparative Examples 1 to 4, the 9-phenylcarbazole structural unit and the triphenylamine structure in which at least one phenyl group has an alkoxy group. It turns out that the polymer which has both shows the heat resistance superior to the polymer which does not contain the said specific structure. Such an improvement in heat resistance makes it easy to maintain a stable driving voltage.

<III> Preparation and Evaluation of Organic EL Element <III-1>
The following examples and comparative examples relate to embodiments in which an organic thin film formed using an organic electronic material (ink composition) containing a charge transporting polymer is applied to a hole injection layer.
(Example 5)
Under a nitrogen atmosphere, charge transporting polymer 1 (10.0 mg), the following dopant 1 (0.5 mg), and toluene (2.3 mL) were mixed to prepare an ink composition. An ink composition was spin-coated on a glass substrate patterned with ITO at a width of 1.6 mm at a rotation speed of 3,000 min ⁻¹ , and then the coating film was cured by heating on a hot plate at 230 ° C. for 30 minutes to obtain a positive coating. A hole injection layer (30 nm) was formed.

　ガラス基板を、真空蒸着機中に移し、正孔注入層上にα－ＮＰＤ（４０ｎｍ）、ＣＢＰ：Ｉｒ（ｐｐｙ）_３（９４：６、３０ｎｍ）、ＢＡｌｑ（１０ｎｍ）、ＴＰＢｉ（３０ｎｍ）、Ｌｉｑ（２．０ｎｍ）、及びＡｌ（１５０ｎｍ）をこの順に蒸着法で成膜した。その後、封止処理を行って有機ＥＬ素子を作製した。

The glass substrate was transferred into a vacuum evaporator, and α-NPD (40 nm), CBP: Ir (ppy) ₃ (94: 6, 30 nm), BAlq (10 nm), TPBi (30 nm), Liq were formed on the hole injection layer. (2.0 nm) and Al (150 nm) were formed in this order by vapor deposition. Then, the sealing process was performed and the organic EL element was produced.

(Example 6)
An organic EL device was produced in the same manner as in Example 5 except that the charge transporting polymer 1 was changed to the charge transporting polymer 2 in the step of forming the hole injection layer in the organic EL device of Example 5.

(Example 7)
An organic EL device was produced in the same manner as in Example 5 except that the charge transporting polymer 1 was changed to the charge transporting polymer 3 in the step of forming the hole injection layer in the organic EL device of Example 5.

(Comparative Example 5)
An organic EL device was produced in the same manner as in Example 5 except that the charge transporting polymer 1 was changed to the charge transporting polymer 7 in the step of forming the hole injection layer in the organic EL device of Example 5.

(Comparative Example 6)
An organic EL device was produced in the same manner as in Example 5 except that the charge transporting polymer 1 was changed to the charge transporting polymer 8 in the step of forming the hole injection layer in the organic EL device of Example 5.

(Comparative Example 7)
An organic EL device was produced in the same manner as in Example 5 except that the charge transporting polymer 1 was changed to the charge transporting polymer 9 in the step of forming the hole injection layer in the organic EL device of Example 5.

Table 3 summarizes the materials used for forming the hole injection layer of the organic EL elements in Examples 5 to 7 and Comparative Examples 5 to 7.

When voltage was applied to each organic EL element obtained in Examples 5 to 7 and Comparative Examples 5 to 7, green light emission was confirmed. For each element, the light emission efficiency at a light emission luminance of 5,000 cd / m ² and the light emission lifetime (luminance half time) at an initial luminance of 5,000 cd / m ² were measured. Table 4 shows the measurement results. For the measurement of luminance, “SR-3AR” manufactured by Topcon Technohouse Co., Ltd. was used.

As shown in Table 4, in Examples 5 to 7, organic EL elements with higher luminous efficiency and longer life were obtained compared to Comparative Examples 5 to 7. From these results, it can be seen that the use of the organic electronic material containing the specific charge transporting polymer required in the present invention can improve the luminous efficiency and the lifetime.

<III-2>
The following examples and comparative examples relate to embodiments in which an organic thin film formed using an organic electronic material (ink composition) containing a charge transporting polymer is applied to a hole transporting layer.
(Example 8)
Under a nitrogen atmosphere, the charge transporting polymer 7 (10.0 mg), the dopant 1 (0.5 mg), and toluene (2.3 mL) were mixed to prepare an ink composition. The ink composition was spin-coated on a glass substrate patterned with a width of 1.6 mm at a rotation speed of 3,000 min ⁻¹ and then cured by heating on a hot plate at 220 ° C. for 10 minutes to form a hole injection layer. (30 nm) was formed.

Next, charge transporting polymer 4 (20.0 mg), the following dopant 2 (0.5 mg), and toluene (2.3 mL) were mixed to prepare an ink composition. On the hole injection layer, the ink composition was spin-coated at a rotation speed of 3,000 min ⁻¹ , and then the coating film was cured by heating on a hot plate at 200 ° C. for 10 minutes to obtain a hole transport layer (40 nm). Formed. The hole transport layer could be formed without dissolving the hole injection layer.

The glass substrate is transferred into a vacuum evaporator and CBP: Ir (ppy) ₃ (94: 6, 30 nm), BAlq (10 nm), TPBi (30 nm), Liq (2.0 nm), and Al (150 nm) was deposited in this order by a vapor deposition method. Then, the sealing process was performed and the organic EL element was produced.

Example 9
An organic EL device was produced in the same manner as in Example 8 except that the charge transporting polymer 4 was changed to the charge transporting polymer 5 in the step of forming the hole transporting layer in the organic EL device of Example 8.

(Example 10)
An organic EL device was produced in the same manner as in Example 8 except that the charge transporting polymer 4 was changed to the charge transporting polymer 6 in the step of forming the hole transport layer in the organic EL device of Example 8.

(Example 11)
An organic EL device was produced in the same manner as in Example 10 except that the charge transporting polymer 7 was changed to the charge transporting polymer 3 in the step of forming the hole injection layer in the organic EL device of Example 10.

(Comparative Example 8)
An organic EL device was produced in the same manner as in Example 8 except that the charge transporting polymer 4 was changed to the charge transporting polymer 8 in the step of forming the hole transport layer in the organic EL device of Example 8.

(Comparative Example 9)
In the hole injection layer forming step in the organic EL device of Example 8, the charge transporting polymer 7 was changed to the charge transporting polymer 9, and in the hole transporting layer forming step, the charge transporting polymer 4 was charged. An organic EL device was produced in the same manner as in Example 8 except that the transporting polymer 7 was used.

Table 5 summarizes the materials used for forming the hole injection layer and the hole transport layer of the organic EL elements in Examples 8 to 11 and Comparative Examples 8 and 9.

When voltage was applied to the organic EL devices obtained in Examples 8 to 11 and Comparative Examples 8 and 9, green light emission was confirmed. For each element, the light emission efficiency at a light emission luminance of 5,000 cd / m ² and the light emission lifetime (luminance half time) at an initial luminance of 5,000 cd / m ² were measured. Table 6 shows the measurement results. For the measurement of luminance, “SR-3AR” manufactured by Topcon Technohouse Co., Ltd. was used.

As shown in Table 6, in Examples 8 to 11, organic EL elements with higher luminous efficiency and longer life were obtained compared to Comparative Examples 8 and 9. From these results, it can be seen that the use of the organic electronic material containing the specific charge transporting polymer required in the present invention can improve the luminous efficiency and the lifetime.

<IV> Production and Evaluation of White Organic EL Element (Lighting Device) (Example 12)
Under a nitrogen atmosphere, the charge transporting polymer 3 (10.0 mg), the dopant 1 (0.5 mg), and toluene (2.3 mL) were mixed to prepare an ink composition. An ink composition was spin-coated on a glass substrate patterned with a width of 1.6 mm at a rotation speed of 3,000 min ⁻¹ , and then the coating film was cured by heating at 220 ° C. for 10 minutes on a hot plate. A hole injection layer (30 nm) was formed.

Next, the charge transporting polymer 6 (20.0 mg), the dopant 2 (0.5 mg), and toluene (2.3 mL) were mixed to prepare an ink composition. The ink composition was spin coated on the hole injection layer at a rotation speed of 3,000 min ⁻¹ and then cured by heating on a hot plate at 230 ° C. for 30 minutes to form a hole transport layer (40 nm). . The hole transport layer could be formed without dissolving the hole injection layer.

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

The glass substrate was transferred into a vacuum vapor deposition machine, and BAlq (10 nm), TPBi (30 nm), Liq (2.0 nm), and Al (150 nm) were formed in this order on the light emitting layer by vapor deposition. Then, the sealing process was performed and the white organic EL element was produced. The white organic EL element could be used as a lighting device.

(Comparative Example 10)
In the step of forming the hole injection layer in the white organic EL device of Example 12, the charge transporting polymer 3 was changed to the charge transporting polymer 7, and in the step of forming the hole transporting layer, the charge transporting polymer 6 was changed to A white organic EL device was produced in the same manner as in Example 12 except that the charge transporting polymer 8 was used.

By applying a voltage to the white organic EL device obtained in Example 12 and Comparative Example 10, measuring the emission lifetime (luminance half-life) in the voltage and the initial luminance 1,000 cd / ^{m 2} in luminance 1,000 cd / ^{m 2} did. Assuming that the voltage of Example 12 was 1.0, the voltage of Comparative Example 10 was 1.09. Further, assuming that the light emission life of Example 12 was 1.0, the light emission life of Comparative Example 10 was 0.33. Thus, the white organic EL element of Example 12 had excellent driving voltage and light emission lifetime.

As described above, the effect of the embodiment of the present invention was shown by the examples. However, according to the present invention, not only the charge transport polymer used in the examples, but also other charge transport polymers can be used in the same manner as long as they do not depart from the scope of the present invention. It is possible to obtain an element.

According to the organic electronic material containing the charge transporting polymer according to the embodiment of the present invention, the organic layer can be easily formed by a wet process. In addition, by improving the heat resistance of the charge transporting polymer, the driving voltage can be stably maintained, and an organic EL element excellent in various element characteristics such as life characteristics can be easily obtained.

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

Claims (14)

An organic electronic material containing a charge transporting polymer comprising a trivalent or higher structural unit having a 9-phenylcarbazole structure and a structural unit having a triphenylamine structure in which at least one phenyl group has an alkoxy group. The organic electronic material according to claim 1, wherein the charge transporting polymer has a polymerizable functional group. * The organic electronic material according to claim 1 or 2, further comprising a dopant. The organic electronic material according to claim 3, wherein the dopant contains an onium salt. An organic thin film formed using the organic electronic material according to any one of claims 1 to 4. An organic electronics element comprising at least one of the organic thin films according to claim 5. An organic electroluminescence device comprising at least one of the organic thin films according to claim 5. The organic electroluminescent element according to claim 7, wherein the organic thin film is a hole injection layer. The organic electroluminescent device according to claim 7, wherein the organic thin film is a hole transport layer. The organic electroluminescence device according to any one of claims 7 to 9, further comprising a flexible substrate. The organic electroluminescent device according to any one of claims 7 to 9, further comprising a resin film substrate. A display element comprising the organic electroluminescent element according to any one of claims 7 to 11. An illumination device comprising the organic electroluminescence element according to any one of claims 7 to 11. A display device comprising the illumination device according to claim 13 and a liquid crystal element as display means.

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