JP2019131670A - Organic electronics material - Google Patents

Abstract

To provide an organic electronics material for an organic electroluminescence element having excellent heat resistance and life properties.SOLUTION: The present invention provides an organic electronics material containing a charge transporting polymer containing a structural unit having an N-phenylphenothiazine structure.SELECTED DRAWING: None

Description

  Embodiments described herein relate generally 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 high molecular 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.

  For this reason, in recent years, development of materials suitable for wet processes has been promoted. 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, Satoshi 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 cost reduction and area increase are easy. 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 element, it is desirable that the polymer compound has an excellent charge transport property.

  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 tends to be easily deteriorated by heat at the time of a high-temperature processing process and driving of an organic EL element. Along with the problem of heat resistance, further improvement is desired particularly from the viewpoint of life characteristics.

  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 transport property, the present inventors have found that a charge transport polymer containing a structural unit having an N-phenylphenothiazine structure has excellent heat resistance and is suitable for an organic electronics material. Found that can be used. 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 an organic electronic material containing a charge transporting polymer comprising a structural unit having an N-phenylphenothiazine structure.
Other embodiment of this invention is related with the organic thin film formed using the organic electronics material of the said embodiment.
Other embodiment of this invention is related with the organic electronics element containing the organic thin film of the said embodiment.
Other embodiment of this invention is related with the organic electroluminescent element containing the organic thin film of the said embodiment.
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.
Other embodiment of this invention is related with the illuminating device of the said embodiment, and the display apparatus provided with the liquid crystal element as a display means.

  According to the embodiments of the present invention, it is possible to provide an organic electronic material including a polymer compound having excellent charge transporting properties and excellent 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 containing the said organic thin film, an organic EL element, a display element using the same, an illuminating device, and a display apparatus 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 graph of a voltage-current density curve when a voltage is applied to each hole-only device obtained in Example 1 and Comparative Example 1. FIG. 3 is a graph of voltage-current density curves when a voltage is applied to each hole-only device obtained in Examples 2-1 and 2-2 and Comparative Examples 2-1 and 2-2.

  Hereinafter, although embodiment of this invention is described in detail, this invention is not limited to these embodiment.

In this specification, an aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. A heteroaryl group is an atomic group obtained by removing one hydrogen atom from an aromatic heterocyclic ring. 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. 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.
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.

<Organic electronics materials>
The organic electronic material according to an embodiment of the present invention includes at least a charge transporting polymer including a structural unit having an N-phenylphenothiazine structure (hereinafter also referred to as “charge transporting polymer A”).
Since the charge transporting polymer A has an excellent charge transporting capability, the use of this polymer can easily improve various device characteristics including the light emission lifetime. The organic electronic material may contain two or more kinds of the charge transporting polymer A.

[Charge transporting polymer A]
The charge transporting polymer A has an ability to transport charges.
The charge transporting polymer A preferably includes a structural unit having an N-phenylphenothiazine structure.
The N-phenylphenothiazine structure is a structure in which a hydrogen atom on a nitrogen atom of phenothiazine is substituted with a phenyl group, and the phenyl group bonded to the nitrogen atom is one or more substituents R ^a and / or one or more linked groups. may have a group, linked substituents R ^a together may form a cyclic structure, an aromatic ring one or more substituents R ^a and / or one or more linking group for forming a phenothiazine skeleton The substituents R ^a may be linked to each other to form a cyclic structure.

The substituent R ^a is preferably each independently —R ¹ , —OR ² , —SR ³ , —OCOR ⁴ , —COOR ⁵ , —SiR ⁶ R ⁷ R ⁸ , a halogen atom, and the polymerizability described later. Selected from the group consisting of groups containing functional groups. R ¹ represents 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, and R ^{2 to} R ⁸ are each independently hydrogen. An 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 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. The substituent R ^a is more preferably —R ¹ or —OR ² , and still more preferably a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group having 2 to 30 carbon atoms ( For example, a phenyl group) or —OR ² (R ² is a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms). When the N-phenylphenothiazine structure has two or more substituents R ^a , they may be the same or different.
As an example of the linking group, a group having one or more hydrogen atoms out of those exemplified as the substituent R ^a (excluding a group containing a polymerizable functional group), and further adding one hydrogen atom. Excluded are divalent groups.

The structural unit having an N-phenylphenothiazine structure may have at least one N-phenylphenothiazine structure, and may have two or more N-phenylphenothiazine structures.
The charge transporting polymer A may have only one type of structural unit having an N-phenylphenothiazine structure, or may have two or more types.

Examples of the structural unit having an N-phenylphenothiazine structure include those represented by any of the following formulas A-1 to A-8. In the following formulas A-1 to A-8, R ^a is the same as the above-described substituent R ^a and is independently selected. k, the number of l and m are each substituents ^{R a,} k is an integer of 0 to 5, l are each independently an integer of 0 to 4, m is independently an integer of 0 to 3 is there. “*” Represents a binding site with another structural unit.

The charge transporting polymer A may be linear or have a structure branched in three or more directions.
The charge transporting polymer A 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 structural unit B having a valence of 3 or more constituting a branched portion. May further be included. The charge transporting polymer A may contain only one type of each structural unit, or may contain a plurality of types. In the charge transporting polymer, each structural unit is bonded to each other at a binding site of “monovalent” to “trivalent or higher”. In the charge transporting polymer A, preferably, the structural unit having an N-phenylphenothiazine structure is included in at least one of the structural units B, L, and T, and is included in at least one of the structural units B and L. Is more preferable.

The charge transporting polymer A is preferably a linear polymer from the viewpoint of easy control of the molecular weight, and has a structure (branched structure) branched in three or more directions from the viewpoint of high charge transporting property and heat resistance. It is preferable.
The linear charge transporting polymer A preferably contains a divalent structural unit having an N-phenylphenothiazine structure, for example, a divalent structural unit having an N-phenylphenothiazine structure and other charge transporting properties. And a divalent structural unit.
Even if the charge transporting polymer A having a structure branched in three or more directions includes a divalent structural unit having an N-phenylphenothiazine structure, for example, a structure having a trivalent or higher structure having an N-phenylphenothiazine structure. It may contain a unit. When a trivalent or higher structural unit having an N-phenylphenothiazine structure is included, it may include at least a monovalent structural unit T constituting a terminal portion, and may further include a divalent structural unit L having charge transportability.

(Construction)
Examples of the partial structure contained in the charge transporting polymer A include the following. The charge transporting polymer A 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”.

Linear charge transporting polymer A

Charge transporting polymer A having a branched structure

  Hereinafter, each structural unit will be described more specifically.

(Structural unit L)
The structural unit L is a divalent structural unit having charge transportability. The structural unit L is not particularly limited as long as it contains an atomic group having the ability to transport charges.
The charge transporting polymer A may contain, as the structural unit L, for example, only a divalent structural unit having an N-phenylphenothiazine structure (hereinafter sometimes referred to as “structural unit La”). Only a divalent structural unit other than may be included, and a structural unit La and a divalent structural unit L other than the structural unit La may be included.

  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 may be selected from a 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 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.

The divalent structural unit La having an N-phenylphenothiazine structure will be described.
When the charge transporting polymer A contains the structural unit La in the molecule, it becomes easy to reduce the driving voltage of the organic EL element and improve the light emission lifetime. Although details are unknown, when an N-phenylphenothiazine structure is introduced, charge transportability is improved. Therefore, it is considered that the use of a charge transporting polymer containing a structural unit having an N-phenylphenothiazine structure contributes to the reduction of the driving voltage of the organic EL element, and hence the improvement of the light emission lifetime.

Preferable specific examples of the structural unit La include, for example, those represented by the above formula (A-1), (A-2) or (A-3). Examples of the structural unit represented by the formula (A-1), (A-2) or (A-3) include the following.

(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. The charge transporting polymer A may include, as the structural unit T, for example, only a monovalent structural unit having an N-phenylphenothiazine structure (hereinafter sometimes referred to as “structural unit Ta”). Only the monovalent structural unit T other than the above may be included, and the structural unit Ta and the monovalent structural unit T other than the structural unit Ta may be included.

  The structural unit T may be 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 other embodiments, as described later, when the charge transporting polymer has a polymerizable functional group at the terminal portion, the structural unit T has a polymerizable structure (for example, a polymerizable functional group such as a pyrrol-yl group). ).

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

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

The monovalent structural unit Ta having an N-phenylphenothiazine structure will be described.
Preferable specific examples of the structural unit Ta include, for example, those represented by the above formula (A-4) or (A-5). Examples of the structural unit represented by the formula (A-4) or (A-5) include the following.

(Structural unit B)
The structural unit B is a trivalent or higher-valent structural unit that constitutes a branched portion when the charge transporting polymer A has a 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.

  The charge transporting polymer A may include, as the structural unit B, for example, only a trivalent or higher valent structural unit having an N-phenylphenothiazine structure (hereinafter also referred to as “structural unit Ba”). Only the trivalent or higher structural unit B other than the unit Ba may be included, and the structural unit Ba and the trivalent or higher structural unit B other than the structural unit Ba may be included.

  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. It may be 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. Examples of the substituent R include R in the structural unit L (except when R ¹ is a hydrogen atom).

The tri- or higher valent structural unit Ba having an N-phenylphenothiazine structure will be described.
When the charge transporting polymer contains the structural unit Ba in the molecule, it becomes easy to reduce the driving voltage of the organic EL element. Although details are unknown, it is considered that the charge transporting polymer containing the structural unit in the molecule is excellent in charge transporting property.

Specific examples of the structural unit Ba include, for example, those represented by the above formula (A-6), (A-7), or (A-8). Examples of the structural unit represented by the formula (A-6), (A-7) or (A-8) include the following.

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

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

  From the viewpoint of increasing the degree of freedom of the polymerizable functional group and facilitating the polymerization reaction, it is preferable that the main skeleton of the charge transporting polymer and the polymerizable functional group are connected by an alkylene chain. In addition, for example, when an organic layer is formed on an electrode, it is connected with a hydrophilic chain such as an ethylene glycol chain or a diethylene glycol chain from the viewpoint of improving the affinity with a hydrophilic electrode such as ITO. preferable. Further, from the viewpoint of facilitating the preparation of the monomer used for introducing the polymerizable functional group, the charge transporting polymer is polymerized with the end of the alkylene chain and / or the hydrophilic chain, that is, with these chains. An ether bond or an ester bond may be present at the connecting portion with the functional group and / or the connecting portion between these chains and the skeleton of the charge transporting polymer. The above-mentioned “group containing a polymerizable functional group” means a polymerizable functional group itself or a group obtained by combining a polymerizable functional group with an alkylene chain or the like. As the group containing a polymerizable functional group, for example, a group exemplified in International Publication No. WO2010 / 140553 can be suitably used.

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

  It is preferable that a large amount of the polymerizable functional group is contained in the charge transporting polymer from the viewpoint of contributing to the change in solubility. On the other hand, from the viewpoint of not 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 A 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 A 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), The average value can be obtained by using the monomer charge corresponding to each structural unit, the weight average molecular weight of the charge transporting polymer, and the like. 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 A may include, for example, a trivalent or higher structural unit Ba having an N-phenylphenothiazine structure, and may further include a structural unit T having a polymerizable functional group.
In another embodiment, the charge transporting polymer A may include, for example, a divalent structural unit La having an N-phenylphenothiazine structure, and may further include a structural unit T having a polymerizable functional group. .

When the charge transporting polymer A contains the structural unit Ba, the proportion of the structural unit Ba contained in the structural unit B is based on the total amount of the structural unit B from the viewpoint of improving the heat resistance and light emission lifetime of the organic EL element. The structural unit Ba is preferably 40 mol% or more, more preferably 50 mol% or more, further preferably 60 mol% or more, and further preferably 70 mol% or more.
Further, when the charge transporting polymer A includes the structural unit La, the structural unit La is preferably 40 mol% or more, more preferably 50 mol% or more, further preferably 60 mol%, based on the total amount of the structural unit L. Above, more preferably 70 mol% or more.
When the charge transporting polymer A includes the structural unit Ta, the structural unit Ta is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more based on the total amount of the structural unit T. .
In particular, from the viewpoint of improving the heat resistance of the charge transporting polymer A, the proportion of the structural unit La and / or Ta is preferably 10 mol% or more, more preferably 20 mol% or more, based on the total structural units of the polymer. Preferably, 30 mol% or more is more preferable. When the charge transporting polymer A includes the structural units La and Ta, the above ratio means the total amount of La and Ta.

(Ratio of structural units B, L, and T)
The proportion of the structural unit B contained in the charge transporting polymer A 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. % Or more is more preferable. In addition, the proportion of the structural unit B is preferably 50 mol% or less, from the viewpoint of suppressing the increase in viscosity and satisfactorily synthesizing the charge transporting polymer A or obtaining sufficient charge transportability, The following is more preferable, and 30 mol% or less is still more preferable. The ratio of the structural unit B means the total amount of the structural unit B including the structural unit Ba.

  The proportion of the structural unit L contained in the charge transporting polymer A is preferably 10 mol% or more, more preferably 20 mol% or more, more preferably 30 mol%, based on the total structural units, from the viewpoint of obtaining sufficient charge transportability. The above 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 A includes the structural unit La, the proportion of the structural unit L means the total amount including the structural unit La.

  The proportion of the structural unit T contained in the charge transporting polymer A is the total structural unit from the viewpoint of improving the characteristics of the organic electronics element or suppressing the increase in viscosity and favorably synthesizing the charge transporting polymer A. As a reference, 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 A contains the structural unit Ta, the proportion of the structural unit T means the total amount including the structural unit Ta.

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

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

The proportion of the structural unit can be determined using the amount of monomer charged corresponding to each structural unit used for synthesizing the charge transporting polymer A. 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 A 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 A 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 A can be produced by various synthesis methods and is not particularly limited. For example, known coupling reactions such as Suzuki coupling, Negishi coupling, Sonogashira coupling, Stille coupling, 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. 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.
Examples of the ionic compound include onium salts. As an onium salt, the compound which consists of cations, such as iodonium and ammonium, and a counter anion is mentioned, for example.

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 A 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 easily change the solubility of the organic layer.

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

[Content]
The content of the charge transporting polymer A is preferably 50% by mass or more, more preferably 70% by mass or more, and more preferably 80% by mass or more based on the total mass of the organic electronic 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 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, 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 A 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 A to the solvent is 0.1% by mass or more, more preferably 0.2% by mass or more, and 0.5% by mass. The amount which becomes the above is still more preferable. The content of the solvent is preferably such that the ratio of the charge transporting polymer A to the solvent is 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less. preferable.

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

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

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

[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 is a schematic cross-sectional view showing an embodiment of an organic EL element. The organic EL element shown in FIG. 1 is an element having a multilayer structure, and includes a substrate 8, an anode 2, a hole injection layer 3, a hole transport layer 6, a light emitting layer 1, an electron transport layer 7, an electron injection layer 5, and a cathode. 4 in this order. In one embodiment, for example, 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. In another embodiment, the organic EL element may have a substrate 8, an anode 2, a hole injection layer 3, a light emitting layer 1, an electron injection layer 5, and a cathode 4 in this order.
Hereinafter, each layer will be described.

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

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

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

  When the light emitting layer includes a phosphorescent material, it is preferable that a host material is further included in addition to the phosphorescent material. As the host material, a low molecular compound, a polymer, or a dendrimer can be used. Examples of the low molecular weight compound include CBP (4,4′-bis (9H-carbazol-9-yl) biphenyl), mCP (1,3-bis (9-carbazolyl) benzene), CDBP (4,4′- Bis (carbazol-9-yl) -2,2′-dimethylbiphenyl), derivatives thereof, and the like include polymers of the organic electronic materials, polyvinyl carbazole, polyphenylene, polyfluorene, derivatives thereof, and the like of the above embodiment. It is done.

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

[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 A contained in the organic electronic material which is an embodiment of the present invention can also be used. In addition, a known material can also be used.

  Examples of known materials that can be used for the hole injection layer and the hole transport layer include 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-styrenesulfonic acid) Salt) (PEDOT: PSS) and the like.

  In one embodiment, when the organic EL element has a hole injection layer and a hole transport layer, the organic electronic material according to the embodiment of the present invention is used for the hole injection layer, and a known material is used for the hole transport layer. Alternatively, other organic electronic materials described above may be used. In one embodiment, the organic EL element may use the organic electronics material according to the embodiment of the present invention for the hole transport layer, and use a known material or the other organic electronics materials for the hole injection layer. .

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

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

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

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

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

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

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

  As a method of forming a white organic EL element, a method of simultaneously emitting light of a plurality of emission colors using a plurality of light emitting materials and mixing the colors can be used. 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.

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

Embodiments of the present invention include the following, but the present invention is not limited to the following embodiments.
<1> An organic electronic material containing a charge transporting polymer containing a structural unit having an N-phenylphenothiazine structure.
<2> The organic electronic material according to <1>, wherein the charge transporting polymer has a polymerizable functional group.
<3> The organic electronic material according to <1> or <2>, further containing a dopant.
<4> The organic electronic material according to <3>, wherein the dopant includes an onium salt.
<5> An organic thin film formed using the organic electronic material according to any one of <1> to <4>.
<6> An organic electronics element comprising the organic thin film according to <5>.
<7> An organic electroluminescence device comprising the organic thin film according to <5>.
<8> The organic electroluminescent element according to <7>, wherein the organic thin film is a hole injection layer.
<9> The organic electroluminescent element according to <7>, wherein the organic thin film is a hole transport layer.
<10> The organic electroluminescent element according to any one of <7> to <9>, further including a flexible substrate.
<11> The organic electroluminescent element according to any one of <7> to <9>, further including a resin film substrate.
<12> The display element provided with the organic electroluminescent element of any one of <7>-<11>.
<13> A lighting device comprising the organic electroluminescent element according to any one of <7> to <11>.
<14> A display device comprising the illumination device according to <13> and a liquid crystal element as a display unit.

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

<I> Synthesis of monomer having N-phenylphenothiazine structure (Synthesis of monomer having N-phenylphenothiazine structure (PT-1))

In a three-necked flask, phenothiazine (19.8 g, 0.1 mol), 4-bromobutylbenzene (21.3 g, 0.1 mol), palladium (II) acetate (0.225 g, 1 mmol), NaOtBu (14.4 g, 0.1 mol). 15 mol) and o-xylene (300 mL) were added, and the flask was moved into the glove box. The solution was bubbled with nitrogen gas for 20 minutes and degassed. P (t-Bu) ₃ (0.606 g, 3 mmol) was added and sealed. The flask was taken out of the glove box, a cooling pipe was attached, and heating and refluxing were performed at 150 ° C. for 5 hours under a nitrogen flow. After cooling the solution, the solution was filtered through Celite and concentrated with an evaporator to obtain a black solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (9: 1) as a developing solution, and 25.3 g of a pale yellow solid of N- (4-butylphenyl) phenothiazine was obtained. Obtained. The yield was 76.3%.

  N- (4-Butylphenyl) phenothiazine (2.14 g, 6.46 mmol) was added to the three-necked flask and dissolved in N, N-dimethylformamide (100 mL). N-Bromosuccinimide (4.02 g, 22.6 mmol) was added little by little under stirring, and then stirred for 6 hours. After concentrating the reaction solution with an evaporator, ethyl acetate and pure water were added to perform extraction and washing with water. The obtained organic layer was concentrated with an evaporator to obtain a dark red solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (4: 1) as a developing solution, and 2.68 g of a monomer (PT-1) having an N-phenylphenothiazine structure was obtained. Obtained. The yield was 84.7%.

(Synthesis of monomer (PT-2) having N-phenylphenothiazine structure)

In a three-necked flask, phenothiazine (19.8 g, 0.1 mol), bromobenzene (15.7 g, 0.1 mol), palladium (II) acetate (0.225 g, 1 mmol), NaOtBu (14.4 g, 0.15 mol), o-Xylene (300 mL) was added and the flask was moved into the glove box. The solution was bubbled with nitrogen gas for 20 minutes and degassed. P (t-Bu) ₃ (0.606 g, 3 mmol) was added and sealed. The flask was taken out of the glove box, a cooling pipe was attached, and heating and refluxing were performed at 150 ° C. for 5 hours under a nitrogen flow. After cooling the solution, the solution was filtered through Celite and concentrated with an evaporator to obtain a black solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (9: 1) as a developing solution to obtain 17.3 g of a light yellow solid of N-phenylphenothiazine. The yield was 63.0%.

  N-phenylphenothiazine (1.07 g, 3.88 mmol) was added to the three-necked flask and dissolved in N, N-dimethylformamide (100 mL). N-bromosuccinimide (3.45 g, 19.4 mmol) was added little by little under stirring, and then stirred for 6 hours. After concentrating the reaction solution with an evaporator, ethyl acetate and pure water were added to perform extraction and washing with water. The obtained organic layer was concentrated with an evaporator to obtain a dark red solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (2: 1) as a developing solution to obtain 1.45 g of a monomer (PT-2) having an N-phenylphenothiazine structure. Obtained. The yield was 73.2%.

<II> 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 containing a structural unit having an N-phenylphenothiazine structure)
To the three-necked round bottom flask, the following monomer PT-1 (4.0 mmol), the following monomer L-1 (5.0 mmol), the following monomer T-1 (2.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was 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 resulting 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 for 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 5,300, and the weight average molecular weight was 8,600.

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 containing a structural unit having an N-phenylphenothiazine structure)
The following monomer PT-2 (2.0 mmol), the monomer L-1 (5.0 mmol), the monomer T-1 (4.0 mmol) and anisole (20 mL) were added to a three-necked round bottom flask. The prepared Pd catalyst solution (7.5 mL) was 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 15,800, and the weight average molecular weight was 78,200.

(Charge transporting polymer 3 containing a structural unit having an N-phenylphenothiazine structure)
To the three-neck round bottom flask, the monomer PT-1 (5.0 mmol), the following monomer L-2 (4.0 mmol), the monomer T-1 (2.0 mmol) and anisole (20 mL) were added. The 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 5,600, and the weight average molecular weight was 10,400.

(Charge transporting polymer 4 containing a structural unit having an N-phenylphenothiazine structure)
To the three-necked round bottom flask, the monomer PT-2 (2.0 mmol), the following monomer L-3 (5.0 mmol), the monomer T-1 (4.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the charge transporting polymer 4 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 4 was 12,500, and the weight average molecular weight was 63,900.

(Charge transporting polymer 5)
To the three-necked round bottom flask, the monomer L-1 (5.0 mmol), the following monomer L-2 (4.0 mmol), the monomer T-1 (2.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was 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 6,600, and the weight average molecular weight was 12,400.

(Charge transporting polymer 6)
To a three-necked round bottom flask, the following monomer B-1 (2.0 mmol), monomer L-3 (5.0 mmol), monomer T-1 (4.0 mmol) and anisole (20 mL) were added. The 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 16,600, and the weight average molecular weight was 58,900.

The monomers used for the preparation of charge transporting polymers 1-6 are summarized in Table 1 below.

<III> Production and Evaluation of Hole-Only Device Using each charge transportable polymer prepared above, a hole-only device was produced as follows, and charge transportability was evaluated from its current density characteristics.

Example 1
Under a nitrogen atmosphere, charge transporting polymer 2 (50.0 mg), the following dopant 1 (2.5 mg), and toluene (1.36 mL) were mixed to prepare an ink composition. After spin-coating the ink composition on a glass substrate patterned with ITO at a width of 1.6 mm at a rotation speed of 3,000 min ⁻¹ , 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.

(Comparative Example 1)
A hole-only device was produced in the same manner as in Example 1 except that the charge transporting polymer 2 was changed to the charge transporting polymer 6 in the hole injection layer forming step in the hole-only device of Example 1.

Table 2 summarizes the materials and heating conditions used for forming the hole injection layer of the hole-only device in Example 1 and Comparative Example 1.

A graph of a voltage-current density curve when voltage is applied to each hole-only device obtained in Example 1 and Comparative Example 1 is shown in FIG.
As is clear from the graph shown in FIG. 2, it can be seen that Example 1 has a large increase in current density with respect to voltage and is excellent in charge transportability compared to Comparative Example 1. As is clear from the comparison between Example 1 and Comparative Example 1, the polymer containing a structural unit having an N-phenylphenothiazine structure is superior to a polymer having no structural unit having an N-phenylphenothiazine structure. It can be seen that

(Example 2-1)
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. After spin-coating the ink composition on a glass substrate patterned with ITO to a width of 1.6 mm at a rotation speed of 3,000 min ⁻¹ , the coating film was cured by heating on a hot plate at 230 ° C. for 30 minutes, 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 2-2)
A hole-only device was produced in the same manner as in Example 2-1, except that the heating on the hot plate was changed to 180 ° C. for 10 minutes in the hole injection layer forming step in the hole-only device of Example 2-1. did.

(Comparative Example 2-1)
A hole-only device was produced in the same manner as in Example 2-1, except that the charge transporting polymer 1 was changed to the charge transporting polymer 5 in the hole injection layer forming step in the hole-only device of Example 2-1. did.

(Comparative Example 2-2)
A hole-only device was fabricated in the same manner as in Comparative Example 2-1, except that the heating on the hot plate was changed to 180 ° C. for 10 minutes in the hole injection layer forming step in the hole-only device of Comparative Example 2-1. did.

  Table 3 summarizes the materials and heating conditions used for forming the hole injection layer of the hole-only devices in Examples 2-1 and 2-2 and Comparative Examples 2-1 and 2-2.

FIG. 3 shows a graph of voltage-current density curves when a voltage is applied to each hole-only device obtained in Examples 2-1 and 2-2 and Comparative Examples 2-1 and 2-2.
As is clear from the graph shown in FIG. 3, the heating conditions for forming the hole injection layer are more severe (ie, higher temperature and longer heating time) than Comparative Example 2-2. In 1, the driving voltage is significantly increased. Here, the drive voltage means a voltage necessary for obtaining a constant current density. On the other hand, as compared with Example 2-2, the drive voltage rises slightly in Example 2-1 where the heating conditions during the formation of the hole injection layer are more severe.
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. In this respect, as is clear from the comparison between Examples 2-1 and 2-2 and Comparative Examples 2-1 and 2-2, the polymer containing a structural unit having an N-phenylphenothiazine structure is N- It turns out that the heat resistance superior to the polymer which does not contain the structural unit which has a phenylphenothiazine structure is shown. Such an improvement in heat resistance makes it easy to maintain a stable driving voltage.

<IV> Production and Evaluation of Organic EL Device The following examples and comparative examples are 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. About.
Example 3
Under a nitrogen atmosphere, the charge transporting polymer 2 (10.0 mg), the dopant 1 (0.5 mg), and toluene (2.3 mL) were mixed to prepare an ink composition. After spin-coating the ink composition on a glass substrate patterned with ITO to a width of 1.6 mm at a rotation speed of 3,000 min ⁻¹ , the coating film was cured by heating on a hot plate at 230 ° C. for 30 minutes, A hole injection layer (30 nm) was formed.

The glass substrate was transferred into a vacuum deposition machine, and α-NPD (40 nm), CBP: Ir (ppy) ₃ (94: 6, 30 nm), BAlq (bis (2-methyl-8-quinolinolate) was formed on the hole injection layer. ) -4- (phenylphenolato) aluminum) (10 nm), TPBi (1,3,5-tris (1-phenyl-1H-benzimidazol-2-yl) benzene) (30 nm), LiF (2.0 nm) And Al (150 nm) were formed in this order by the vapor deposition method. Then, the sealing process was performed and the organic EL element was produced.

(Comparative Example 3)
An organic EL device was produced in the same manner as in Example 3 except that the charge transporting polymer 2 was changed to the charge transporting polymer 6 in the step of forming the hole injection layer in the organic EL device of Example 3.

Table 4 summarizes the materials used for forming the hole injection layer of the organic EL device in Example 3 and Comparative Example 3 above.

When voltage was applied to each organic EL element obtained in Example 3 and Comparative Example 3, 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 5 shows the measurement results. For the measurement of luminance, “SR-3AR” manufactured by Topcon Techno House Co., Ltd. was used.

  As shown in Table 5, in Example 3, an organic EL element having a higher luminous efficiency and a longer lifetime was obtained as compared with Comparative Example 3. 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.

  As described above, the effects of the embodiments of the present invention are 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 which is an 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 comprising a charge transporting polymer comprising a structural unit having an N-phenylphenothiazine structure.   The organic electronic material according to claim 1, wherein the charge transporting polymer has a polymerizable functional group.   The organic electronic material of Claim 1 or 2 which further contains a dopant.   The organic electronics material of claim 3, wherein the dopant comprises an onium salt.   The organic thin film formed using the organic electronics material of any one of Claims 1-4.   An organic electronic device comprising the organic thin film according to claim 5.   An organic electroluminescence device comprising the organic thin film 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 element according to claim 7, wherein the organic thin film is a hole transport layer.   The organic electroluminescent element of any one of Claims 7-9 which further has a flexible substrate.   The organic electroluminescent element of any one of Claims 7-9 which further has a resin film board | substrate.   The display element provided with the organic electroluminescent element of any one of Claims 7-11.   The illuminating device provided with the organic electroluminescent element of any one of Claims 7-11.   A display device comprising the illumination device according to claim 13 and a liquid crystal element as a display means.

Images