JP2018104718A - Charge transporting material, ink composition using the material, organic electronics element, organic electroluminescent element, display element, display device and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge transporting material containing a polymer compound which facilitates deposition by coating method and is available in an organic electronics element, and to provide an ink composition containing the material, an organic electronics element excellent in luminous efficiency and emission lifetime, an organic EL element, and a display element, a lighting system, and a display device using them.SOLUTION: A polymer compound contains a first structural unit derived from a condensed polycyclic aromatic hydrocarbon and having three or more branches, and at least three second structural units having charge transportability coupled to the branch of the first structural unit, and the polymer compound is used as a charge transporting material.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a charge transport material and an ink composition using the material. In another embodiment of the present invention, an organic electronic device, an organic electroluminescent device (hereinafter also referred to as “organic EL device”) using the charge transporting material or an ink composition containing the material, The present invention relates to a display element, a lighting device, and a display device.

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

  Examples of organic electronics elements include organic EL elements, organic photoelectric conversion elements, and organic transistors.

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

  Organic EL elements are roughly classified into two types, low molecular organic EL elements and polymer organic EL elements, from the organic materials used. In the polymer organic EL element, a polymer material is used as an organic material, and in the low molecular organic EL element, a low molecular material is used. Compared with low-molecular-weight organic EL elements, which are mainly deposited in a vacuum system, polymer-type organic EL elements can be easily formed by wet processes such as printing and inkjet. It is expected as an indispensable element for screen organic EL displays.

  For this reason, in recent years, development of polymer materials suitable for wet processes has been promoted, and for example, studies as described in Patent Document 1 have been conducted.

JP 2006-279007 A

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

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

  As a result of intensive studies, the present inventors have found that a polymer compound having a specific structural unit is suitable as a charge transporting material, and have completed the present invention. That is, the present invention relates to the matters described below.

  (1) A charge transporting material comprising a polymer compound having a branched structure branched in three or more directions and having a charge transporting property, wherein the polymer compound is derived from a condensed polycyclic aromatic hydrocarbon. And a charge transporting material comprising at least three first structural units having three or more branch portions and second structural units having charge transport properties bonded to the branch portions of the first structural unit.

  (2) The first structural unit is at least one selected from the group consisting of anthracene, tetracene, pentacene, phenanthrene, chrysene, triphenylene, tetraphen, pyrene, picene, pentaphen, perylene, helicene, coronene anthracene, and tetracene. The charge transporting material according to (1) above, comprising a structure derived from a condensed polycyclic aromatic hydrocarbon of a kind.

  (3) The second structural unit has at least one structure selected from the group consisting of an aromatic amine structure, a carbazole structure, a thiophene structure, a bithiophene structure, a p-phenylene structure, an m-phenylene structure, and a fluorene structure. The charge transporting material according to (1) or (2) above.

  (4) The charge transport material according to any one of (1) to (3), which is used as a hole transport material.

  (5) An ink composition comprising the charge transporting material according to any one of (1) to (4) above and a solvent.

  (6) An organic electronic device having an organic layer containing the charge transporting material according to any one of (1) to (4) above.

  (7) An organic electroluminescence device having an organic layer containing the charge transporting material according to any one of (1) to (4).

  (8) The organic electroluminescent element according to (7), further including a flexible substrate.

  (9) The organic electroluminescent element according to (8), wherein the flexible substrate includes a resin film.

  (10) A display device comprising the organic electroluminescent device according to any one of (7) to (9).

  (11) A lighting device including the organic electroluminescent element according to any one of (7) to (9).

  (12) A display device comprising the illumination device according to (11) above and a liquid crystal element as display means.

  According to the embodiment of the present invention, it is possible to provide a charge transporting material containing a polymer material that can be suitably used for an organic electronic device, and an ink composition containing the material. In addition, by using the ink composition, an organic electronics element and an organic EL element having a low driving voltage and excellent light emission efficiency and light emission lifetime, and a display element, an illumination device, and a display device using the same are provided. Can do.

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

Hereinafter, embodiments of the present invention will be described.
<Charge transport material>
One embodiment of the present invention relates to a charge transporting material. The charge transporting material includes a polymer compound having a branched structure branched in three or more directions and having a charge transporting property. The polymer compound is derived from a condensed polycyclic aromatic hydrocarbon and has a first structural unit having three or more branched parts, and a charge transporting property bonded to the branched parts of the first structural unit. It has at least three second structural units. By using such a specific polymer compound as a charge transporting material, it is possible to improve the durability of the organic EL element, and to further improve the light emission efficiency and the light emission lifetime.

Hereinafter, the polymer compound will be described in detail.
(Polymer compound)
In the polymer compound contained in the charge transport material, the “branched structure branched in three or more directions” means a chain having the largest degree of polymerization among various chains in one molecule of the polymer compound. When a chain is used, it means that there are three or more side chains having the same degree of polymerization as the main chain or a lower degree of polymerization. In the present invention, the degree of polymerization represents how many monomer units used for synthesizing a polymer compound are contained per molecule of the polymer compound. In the present invention, the side chain is a chain different from the main chain of the polymer compound and has at least one polymer unit, and the other side is regarded as a substituent rather than a side chain. That is, in the present invention, the above “branched structure branched in three or more directions” means that the above bond is bonded to the first structural unit derived from a condensed polycyclic aromatic hydrocarbon and having three or more bonds. It is intended to include a structure formed by combining at least three second structural units having charge transporting properties.

  The condensed polycyclic aromatic hydrocarbon for deriving the first structural unit is a compound in which a plurality of aromatic rings are condensed, and it is easy to obtain excellent charge transportability. An aromatic ring is preferably present. Considering the solubility of the charge transport material, the number of aromatic rings present in the molecule is preferably in the range of 3-6. The condensed polycyclic aromatic hydrocarbon may be one in which a plurality of aromatic rings are linearly connected or non-directly connected.

  In a preferred embodiment, the condensed polycyclic aromatic hydrocarbon from which the first structural unit is derived is anthracene, tetracene, pentacene, phenanthrene, chrysene, triphenylene, tetraphen, pyrene, picene, pentaphen, perylene, helicene, and It includes at least one structure selected from the group consisting of coronene. Although not particularly limited, it is more preferable that the first structural unit includes a structural unit derived from pyrene because it is easy to obtain excellent charge transportability and durability.

  In a preferred embodiment, the second structural unit is easy to obtain an excellent charge transport property, and thus has an aromatic amine structure, carbazole structure, thiophene structure, bithiophene structure, p-phenylene structure, m- It includes at least one structure selected from the group consisting of a phenylene structure and a fluorene structure. Among these, it is more preferable to include at least one selected from the group consisting of an aromatic amine structure, a carbazole structure, a thiophene structure, and a bithiophene structure.

  The polymer compound can be synthesized by a method well known to those skilled in the art. Although not particularly limited, the polymer compound is produced by polymerizing various monomers including, for example, a condensed polycyclic aromatic hydrocarbon monomer having three or more polymerizable sites in one molecule. Can do. Alternatively, it may be produced by forming linear polymer compounds and then polymerizing them. When the polymer compound is a copolymer, the copolymer may be a random, block or graft copolymer, or a copolymer having an intermediate structure thereof, for example, a block property. It may be a random copolymer.

  In one embodiment, the polymer compound is an oligomer or a polymer obtained by a reaction between a first monomer compound containing the first structural unit and a second monomer compound containing the second structural unit. . A well-known method in this technical field can be applied to the above reaction. For example, a Suzuki coupling reaction in which a bond is formed between a boronic acid and a halogen such as bromine can be applied using a Pd (0) or Pd (II) compound as a catalyst. For a specific method for preparing the polymer compound using the Suzuki coupling reaction, for example, the description in WO2010 / 140553 can be referred to.

  Specific examples of each monomer compound that can be suitably used when preparing a polymer compound using the Suzuki coupling reaction are shown below.

  In the formula, each R represents an independent group, and in each monomer compound, at least three R in the molecule are reactive substituents selected from a residue of boronic acid or boronic acid ester, a triflate group, and a halogen group. Have The present invention intends to form a polymer compound having a branched structure branched in three or more directions by binding such a reactive substituent to a branched portion and a structural unit having charge transporting properties. ing. In the monomer compound, R other than the reactive substituent is a hydrogen atom, a linear, cyclic or branched alkyl group, alkenyl group, alkynyl group, alkoxy group having 1 to 22 carbon atoms, and carbon number. It is at least one selected from the group consisting of 2 to 30 aryl groups and heteroaryl groups.

  Although it does not specifically limit, the compound which has the pyrene structure shown below among the said 1st monomer compounds is preferable. When the polymer compound includes a structural unit derived from pyrene, it is easy to obtain excellent charge transportability and durability.

  In the polymer compound, the proportion of the first structural unit is preferably 1 mol% or more, more preferably 3 mol% or more, and most preferably 5 mol% or more. On the other hand, the proportion of the first structural unit is preferably 95 mol% or less, more preferably 90 mol% or less, and most preferably 85 mol% or less. If the said ratio is in the said range, it will become easy to obtain the outstanding durability and the outstanding charge transportability. Moreover, the said ratio is preferable also in the point from which the high molecular compound which has moderate molecular weight as a charge transport material is obtained. The said ratio can be adjusted as a ratio (molar ratio) of the said 1st monomer with respect to the sum total of the preparation amount of the various monomer compounds used as a raw material at the time of preparation of the said high molecular compound.

  In the formula, each R represents an independent substituent, and in each monomer compound, at least one R, preferably two R, are selected from a residue of a boronic acid or boronic ester, a triflate group, and a halogen group Has a reactive substituent. In the monomer compound, R other than the reactive substituent is a hydrogen atom, a linear, cyclic or branched alkyl group, alkenyl group, alkynyl group, alkoxy group having 1 to 22 carbon atoms, and carbon number. It is at least one selected from the group consisting of 2 to 30 aryl groups and heteroaryl groups. In the formula, X represents either an ether group or a methylene group.

  Although it does not specifically limit, the compound which has a structure shown below among the said 2nd monomer compounds is preferable. In particular, when a compound including a structural unit having a triphenylamine structure is used, excellent hole transportability can be easily obtained when the polymer compound is used as the charge transport material.

In the polymer compound, the ratio of the second structural unit having the charge transporting property is preferably 10 mol% or more, more preferably 20 mol% or more, and more preferably 30% mol or more from the viewpoint of obtaining sufficient charge transportability. Is most preferred. On the other hand, the ratio of the second structural unit is preferably 95 mol% or less, more preferably 90 mol% or less, and most preferably 85 mol% or less. If the said ratio is in the said range, it will become easy to obtain the outstanding durability and the outstanding charge transportability.
In addition, the ratio of the said structural unit can be adjusted as a ratio (molar ratio) of the said 2nd monomer compound with respect to the sum total of the preparation amount of each monomer compound used as a raw material at the time of preparation of the said high molecular compound.

  Although it does not specifically limit, the high molecular compound by this invention obtained by the Suzuki coupling reaction between the above-mentioned 1st and 2nd monomer compounds has a structural unit (X), for example.

  In the formula, A, B, and C mean structural units derived from the monomer compound used as a raw material.

An example of the polymer compound having the structural unit (X) is shown below.

  In another embodiment, the polymer compound preferably has one or more polymerizable substituents in the molecule in order to change the solubility. Here, “polymerizable substituent” (hereinafter referred to as “polymerizable substituent”) refers to a substituent capable of forming a bond between two or more molecules during the polymerization reaction of the polymer compound. means.

  Specific examples of the polymerizable substituent include a group having a carbon-carbon multiple bond, a group having a small ring, a lactone group, a lactam group, and a group containing a siloxane derivative. Specific examples of the group having a carbon-carbon multiple bond include vinyl group, acetylene group (ethynyl group), butenyl group, acrylic group (acryloyl group), acrylate group (acryloyloxy group), acrylamide group (acryloylamino group), Methacryl group (methacryloyl group), methacrylate group (methacryloyloxy group), methacrylamide group (methacryloylamino group), aryl group, allyl group, vinyl ether group (vinyloxy group), vinylamino group, furan-yl group, pyrrol-yl group , A thiophen-yl group, and a silol-yl group. Specific examples of the group having a small ring include a cyclopropyl group, a cyclobutyl group, an epoxy group (oxiranyl group), an oxetane group (oxetanyl group), a diketene group, and an episulfide group.

  Another example of the polymerizable substituent is a combination of substituents capable of forming an ester bond or an amide bond. For example, a combination of an ester group and an amino group, or a combination of an ester group and a hydroxyl group.

  In one embodiment, from the viewpoint of reactivity, the polymer compound is particularly selected from the group consisting of an oxetane group, an epoxy group, a vinyl group, a vinyl ether group, an acrylate group, and a methacrylate group as the polymerizable substituent. It preferably contains at least one group. Most preferably, the polymer compound contains at least one of an oxetane group and a vinyl group.

  In order to increase the degree of freedom of the polymerizable substituent and to facilitate the curing reaction of the polymer compound, the polymerizable substituent has 1 to 8 carbon atoms relative to the structural unit in the polymer compound. Bonding via an alkyl chain is preferred. Moreover, when using the said high molecular compound as a film | membrane material of an organic EL element, the said polymeric substituent is couple | bonded with the hydrophilic group from a viewpoint of improving the affinity with hydrophilic films, such as ITO, and a film | membrane. It is preferable. Examples of the hydrophilic group include alkyleneoxy chains having 2 to 8 carbon atoms such as ethylene glycol chains and diethylene glycol chains. Furthermore, from the viewpoint of facilitating the preparation of the polymer compound having the polymerizable substituent, it has a terminal portion of the alkyl chain or alkyleneoxy chain, that is, a linking portion with the polymerizable substituent, and a hole transport property. The connecting portion with the second structural unit may have an ether bond. As specific examples of the polymerizable substituent, the substituents exemplified in JP 2012-253067 A can be referred to.

  Although not particularly limited, the polymer compound having a polymerizable substituent may be, for example, a Suzuki coupling using a third monomer exemplified below in addition to the first and second monomers. It can be prepared by carrying out the reaction.

  In the formula, X is a reactive substituent selected from the group consisting of boronic acid or boronic acid ester residues, triflate groups, and halogen groups. R represents an independent substituent, and at least one R is the polymerizable substituent. The monomer compound has a hydrogen atom, a linear, cyclic or branched alkyl group, alkenyl group, alkynyl group, and alkoxy group as a substituent R other than the polymerizable substituent, and It has a group selected from the group consisting of an aryl group having 2 to 30 carbon atoms and a heteroaryl group.

Specific examples of the structure of the polymerizable substituent include the following.

  When the polymer compound has a polymerizable substituent, the substituent may be connected to the main chain of the molecular chain or may be connected to the end of the molecular chain. Since the introduction of the substituent is easy, the substituent is preferably located at the end of the molecular chain.

  Although it does not specifically limit, The following is mentioned as an example of the compound which can be used conveniently as a 3rd monomer.

  When the polymer compound has a polymerizable substituent, the number of polymerizable substituents contained in the molecule is not particularly limited. However, since it becomes easy to change the solubility, the polymer compound preferably contains two or more of the substituents, more preferably three or more, in the molecule.

  The number of polymerizable substituents per molecule of the polymer compound can be adjusted by the ratio of the third monomer that derives the structural unit having the polymerizable substituent. From the viewpoint of introducing the polymerizable substituent, the ratio of the third monomer to the total amount of all monomers used in preparing the polymer compound is preferably 0.1 mol% or more, more preferably 1 mol% or more. Preferably, 3 mol% or more is most preferable. When the ratio of the third monomer is within the above range, it is also preferable in that the solubility of the polymer compound can be easily changed. Further, from the viewpoint of obtaining good hole transportability in the polymer compound, the proportion of the third monomer is preferably 70 mol% or less, more preferably 60 mol% or less, and further preferably 50 mol% or less. When the ratio of the third monomer is within the above range, it is also preferable in that it is easy to obtain a sufficient molecular weight in the polymer compound.

  Although it does not specifically limit, As one Embodiment of the said high molecular compound, the compound obtained by reaction between the following monomers is mentioned.

  Another embodiment of the polymer compound includes a compound obtained by a reaction between the following monomers.

  The number average molecular weight of the polymer compound can be appropriately adjusted in consideration of solubility in a solvent and film formability. From the viewpoint of excellent hole transportability, the number average molecular weight is preferably 500 or more, more preferably 1,000 or more, and further preferably 2,000 or more. Further, from the viewpoint of maintaining good solubility in a solvent and facilitating the preparation of a coating solution or coating ink, the number average molecular weight is preferably 1,000,000 or less, preferably 100,000 or less. More preferably, it is more preferably 50,000 or less. A number average molecular weight means the number average molecular weight of standard polystyrene conversion by gel permeation chromatography (GPC).

  The weight average molecular weight of the polymer compound can be appropriately adjusted in consideration of solubility in a solvent and film formability. 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 hole transportability. From the viewpoint of maintaining good solubility in a solvent and facilitating the preparation of a coating solution or coating ink, the weight average molecular weight is preferably 1,000,000 or less, and preferably 700,000 or less. More preferably, it is more preferably 400,000 or less. A weight average molecular weight means the weight average molecular weight of standard polystyrene conversion by gel permeation chromatography (GPC).

  In this specification, the charge transport material is intended to be essentially composed of the above-described polymer compound. However, in one embodiment, the charge transport material of the present invention may contain various additives well known as charge transport materials in the art in addition to the polymer compound. For example, the charge transporting material may further include an electron accepting compound that can act as an electron acceptor for the polymer compound in order to adjust the charge transporting property. When the charge transporting material contains an electron accepting compound, it is preferable in that it is easier to obtain excellent hole transporting properties.

Hereinafter, the electron-accepting compound will be described.
(Electron-accepting compound)
As the electron-accepting compound, specifically, both inorganic and organic materials can be used. For example, electron-accepting compounds described in patent documents (Japanese Patent Laid-Open Nos. 2003-031365 and 2006-233162), Super Bronsted described in Japanese Patent Nos. 3957635 and 2012-72310. Acid compounds and derivatives can be used. In addition, for example, an onium salt containing one kind selected from the following cations and one kind selected from the following anions can be used.

(Cation)
Examples of the cation include H ⁺ , carbenium ion, ammonium ion, anilinium ion, pyridinium ion, imidazolium ion, pyrrolidinium ion, quinolinium ion, imonium ion, aminium ion, oxonium ion, and pyrylium ion. , Chromenilium, xanthylium ion, iodonium ion, sulfonium ion, phosphonium ion, tropylium ion, cation with transition metal, etc., carbenium ion, ammonium ion, anilinium ion, aminium ion, iodonium ion, sulfonium ion Tropylium ion is preferred. Ammonium ion, anilinium ion, iodonium ion, and sulfonium ion are more preferable from the viewpoint of compatibility between the solubility change characteristics of the composition and storage stability.

(Anion)
Examples of the anion include halogen ions such as F ⁻ , Cl ⁻ , Br ⁻ and I ⁻ ; OH ⁻ ; ClO ₄ ⁻ ; FSO ₃ ⁻ , ClSO ₃ ⁻ , CH ₃ SO ₃ ⁻ and C ₆ H ₅ SO ₃ ^−. , Sulfonate ions such as CF ₃ SO ₃ ^— , sulfate ions such as HSO ₄ ⁻ , SO ₄ ²⁻ ; carbonate ions such as HCO ₃ ⁻ , CO ₃ ²⁻ ; H ₂ PO ₄ ⁻ , HPO ₄ ^{2. -,} phosphate ion such as _{^{PO 4 3-; PF 6 -,}} PF 5 OH - fluorophosphate ions such _{as; [(CF 3 CF 2)} 3 PF 3] -, [(CF 3 CF 2 CF 2 ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₂ PF ₄ ] ⁻ , [((CF ₃ ) ₂ CFCF ₂ ) ₃ PF _{3 ^{] -, [((CF 3}} ) CFCF _{2) 2} PF _4] ^- a fluorinated alkyl fluorophosphate ions such ^{_{as; (CF 3 SO 2) 3}} C -, (CF 3 SO 2) 2 N - fluoroalkanes methide such as, imide ion such; BF _{^{4 -, B (C 6 F}} 5) 4 -, B (C 6 H 4 CF 3) 4 - borate ions such _{^{as; SbF 6 -, SbF 5 OH}} - fluoro antimonate ion such as; AsF ₆ ^- , _AsF 5 OH ^- fluoroarsenate periodate ions such as; AlCl ₄ ^-, BiF ₆ ^-, and the like. Among them, fluorophosphate ions such as PF ₆ ⁻ and PF ₅ OH ^— , [(CF ₃ CF ₂ ) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , [(( CF ₃ ) ₂ CF) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₂ PF ₄ ] ⁻ , [((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ] ⁻ and [((CF ₃ ) ₂ CFCF _{2) 2} PF _4] ^- a fluorinated alkyl fluorophosphate ions such ^{_{as; (CF 3 SO 2) 3}} C -, (CF 3 SO 2) 2 N - fluoroalkanes methide such as imide ion such, BF _{^{4 -, B (C 6 F}} 5) 4 -, B (C 6 H 4 CF 3) 4 - borate ion such _{^{as, SbF 6 -, SbF 5 OH}} - compounds containing fluoro antimonate ion such as is Like Yes.

In one embodiment, it is preferable to use an onium salt having an anion as the electron-accepting compound. Specific examples of the compound include the ionic compound (I) shown below.

  In the case of using an electron-accepting compound, the proportion thereof is preferably 0.01% by mass or more based on the total mass of the charge transporting material from the viewpoint of improving the charge transporting property of the charge transporting material. It is more preferably 1% by mass or more, and further preferably 0.5% by mass or more. Further, from the viewpoint of maintaining good film formability, it is preferably 50% by mass or less, more preferably 30% by mass or less, and more preferably 20% by mass or less with respect to the total mass of the charge transporting material. More preferably.

<Ink composition>
One embodiment of the present invention relates to an ink composition containing the charge transporting material and a solvent. As the solvent, a solvent capable of forming a coating layer using the charge transporting material can be used. Preferably, a solvent that can dissolve the charge transporting material can be used. The ink composition has excellent durability and charge transportability because the polymer compound in the charge transport material has a specific branched structure. Therefore, it can be suitably used as a material for a thin film constituting an organic layer such as an organic electronic device. The ink composition can easily form the organic layer by a simple method such as a coating method.

  Examples of the solvent include water; alcohols such as methanol, ethanol and isopropyl alcohol; alkanes such as pentane, hexane and octane; cyclic alkanes such as cyclohexane; aromatic carbonization such as benzene, toluene, xylene, mesitylene, tetralin and diphenylmethane. Hydrogen; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3 -Aromatic ethers such as methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole; ethyl acetate, n-butyl acetate, ethyl lactate, milk aliphatic esters such as n-butyl; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate; N, N-dimethylformamide, N, N- Amide solvents such as dimethylacetamide; dimethyl sulfoxide, tetrahydrofuran, acetone, chloroform, methylene chloride and the like. The solvent preferably contains one or more selected from the group consisting of aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, and aromatic ethers.

  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 polymer compound in the charge transporting material is 0.1% by mass or more, more preferably 0.2% by mass or more with respect to the solvent. The amount of 0.5% by mass or more is more preferable. Further, the content of the solvent is preferably such that the ratio of the polymer compound in the charge transporting material to the solvent is 10% by mass or less, more preferably 5% by mass or less, and more preferably 3% by mass or less. More preferred is an amount of

  Examples of the method for applying the ink composition include an inkjet method, a casting method, a dipping method, letterpress printing, intaglio printing, offset printing, planographic printing, letterpress reverse printing, screen printing, gravure printing, and the like, and Known methods such as a spin coating method may be mentioned. Moreover, when forming an organic layer by the apply | coating method, after apply | coating an ink composition, the obtained application layer may be dried with a hotplate or oven, and a solvent may be removed.

  When the polymer compound in the charge transporting material has a polymerizable substituent, the coating film can be cured by polymerization. Therefore, it is easy to add an organic layer by a coating method to achieve multilayering. It becomes. As a trigger for initiating the polymerization of the polymer compound, methods such as light irradiation and heating are generally used. Although there is no restriction | limiting in particular, From the viewpoint that a process is simple, the method by a heating is preferable. Heating can be performed on a hot plate or in an oven.

  The heating temperature and the heating time can be adjusted as long as the polymerization reaction can be sufficiently advanced. Although there is no restriction | limiting in particular, The said heating temperature becomes like this. Preferably it is 300 degrees C or less, More preferably, it is 250 degrees C or less, More preferably, it is 200 degrees C or less. Various substrates can be applied within the above temperature range. From the viewpoint of increasing the polymerization rate of the coating layer, the heating temperature is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, and further preferably 60 ° C. or higher. The heating time is preferably 2 hours or less, more preferably 1 hour or less, and even more preferably 30 minutes or less from the viewpoint of increasing productivity. From the viewpoint of allowing the polymerization to proceed completely, the heating time is preferably 1 minute or longer, more preferably 3 minutes or longer, and even more preferably 5 minutes or longer.

  When using the light irradiation method, a light source such as a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a xenon lamp, a fluorescent lamp, a light-emitting diode, or sunlight can be used.

  The ink composition may contain various additives in addition to the charge transporting material and the solvent. Specific examples of various additives include polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, antioxidants, oxidizing agents, reducing agents, surface modifiers, emulsifiers, antifoaming agents. , Dispersants, and surfactants.

<Organic electronics elements>
One embodiment of the present invention relates to an organic electronic element having an organic layer containing the charge transporting material. The organic electronics element means an element having a structure in which the organic layer is disposed between at least a pair of electrodes, such as an organic electroluminescence (organic EL) element, an organic thin film solar cell, and an organic light emitting transistor. That is, the organic electronic device according to the present invention is characterized by having an organic layer containing a specific polymer compound having a specific branched structure and having a charge transporting property. Therefore, it is considered that by using the charge transporting material, excellent durability and charge transportability can be obtained in various devices having the organic layer without being limited to a specific device. As one embodiment, the organic electronic device has an organic layer obtained by applying an ink composition containing the charge transporting material. When the polymer compound in the charge transporting material has a polymerizable substituent, the organic layer can be easily multilayered by a coating method. Hereinafter, a specific embodiment of the organic EL element will be described as an example.

<Organic EL device>
An organic EL device according to an embodiment of the present invention has an organic layer containing the charge transporting material. The organic EL element usually has a substrate, at least a pair of an anode and a cathode, and a light-emitting layer, and if necessary, such as a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer. It may have a functional layer. In one embodiment of the organic EL element, at least one of the light emitting layer and the other functional layer can be configured using the organic layer. In one embodiment, the organic layer is preferably used to constitute a functional layer including at least one of a hole injection layer and a hole transport layer.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of an organic EL device according to the present invention. In FIG. 1, the structure of the organic EL element which has the multilayer organic layer comprised from the light emitting layer shown with the referential mark 1, and several other functional layers is illustrated. In the figure, reference numeral 2 is an anode, 3 is a hole injection layer, 4 is a cathode, and 5 is an electron injection layer. Reference numeral 6 denotes a hole transport layer, 7 denotes an electron transport layer, and 8 denotes a substrate. Hereinafter, each layer will be described in detail.

(Light emitting layer)
As a compound having a function other than the charge transport function, a known material used for a light-emitting layer can be used. The material used for the light emitting layer may be a low molecular compound, a polymer or an oligomer, and a dendrimer or the like can also be used. Low molecular weight compounds that utilize fluorescence include perylene, coumarin, rubrene, quinacridone, dye dyes for dye laser (eg, rhodamine, DCM1, etc.), aluminum complexes (eg, Tris (8-hydroxyquinolinato) aluminum (III) (Alq ₃ )), Stilbene, and derivatives thereof. Polymers or oligomers that utilize fluorescence include polyfluorene, polyphenylene, polyphenylene vinylene (PPV), polyvinyl carbazole (PVK), fluorene-benzothiadiazole copolymer, fluorene-triphenylamine copolymer, and derivatives thereof. And a mixture can be suitably used.

  On the other hand, in recent years, phosphorescent organic EL elements have been actively developed in order to increase the efficiency of organic EL elements. In the phosphorescent organic EL element, not only singlet state energy but also triplet state energy can be used, and the internal quantum yield can be increased to 100% in principle. In a phosphorescent organic EL element, phosphorescence is extracted by doping a host material with a metal complex phosphorescent material containing a heavy metal such as platinum or iridium as a phosphorescent dopant (MA Baldo et al., Nature, vol. 395). , p. 151 (1998), MA Baldo et al., Applied Physics Letters, vol. 75, p. 4 (1999), MA Baldo et al., Nature, vol. 403, p. 750 (2000)) .

Also in the organic EL device of the present invention, it is preferable to use a phosphorescent material for the light emitting layer from the viewpoint of high efficiency. As the phosphorescent material, a metal complex containing a central metal such as Ir or Pt can be preferably used. Specifically, as an Ir complex, for example, FIr (pic) [iridium (III) bis [(4,6-difluorophenyl) -pyridinate-N, C ² ] picolinate] that emits blue light and green light are emitted. Ir (ppy) ₃ [Factris (2-phenylpyridine) iridium] (see MA Baldo et al., Nature, vol. 403, p. 750 (2000)), or emits red light (btp) ₂ Ir ( acac) {Bis [2- (2′-benzo [4,5-α] thienyl) pyridinate-N, C ³ ] iridium (acetyl-acetonate)} (Adachi et al., Appl. Phys. Lett., 78 no 11, 2001, 1622), Ir (piq) ₃ [tris (1-phenylisoquinoline) iridium] and the like.

  Examples of the Pt complex include 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-forphineplatinum (PtOEP) that emits red light. The phosphorescent material can be a small molecule or a dendrite species, such as an iridium nucleus dendrimer. Moreover, these derivatives can also be used conveniently.

  In the case where the light emitting layer includes a phosphorescent material, it is preferable that a host material be included in addition to the phosphorescent material. The host material may be a low molecular compound or a high molecular compound, and a dendrimer or the like can also be used.

  Examples of low molecular weight compounds include α-NPD (N, N′-Di (1-naphthyl) -N, N′-diphenylbenzidine) and CBP (4,4′-Bis (carbazol-9-yl) -biphenyl). , MCP (1,3-Bis (9-carbazolyl) benzene), CDBP (4,4'-Bis (carbazol-9-yl) -2,2'-dimethylbiphenyl), etc. Polyvinylcarbazole, polyphenylene, polyfluorene and the like can be used, and derivatives thereof can also be used.

The light emitting layer may be formed by a vapor deposition method or a coating method.
When forming by the apply | coating method, an organic EL element can be manufactured cheaply and it is more preferable. In order to form the light emitting layer by a coating method, a solution containing a phosphorescent material and, if necessary, a host material, for example, an ink jet method, a casting method, a dipping method, a relief printing, an intaglio printing, an offset printing, a lithographic printing, a relief printing It can be carried out by applying on a desired substrate by a known method such as a printing method such as reverse offset printing, screen printing or gravure printing, or spin coating method.

(cathode)
The cathode material is preferably a metal or metal alloy such as Li, Ca, Mg, Al, In, Cs, Ba, Mg / Ag, LiF, and CsF. The formation of the cathode is not particularly limited, and can be performed by applying a known method.

(anode)
As the anode, a metal (for example, Au) or other material having metal conductivity, for example, an oxide (for example, ITO: indium oxide / tin oxide), a conductive polymer (for example, a polythiophene-polystyrene sulfonic acid mixture (for example, PEDOT: PSS)) can also be used. The formation of the anode is not particularly limited, and can be performed by applying a known method.

(Other functional layers)
In addition to the light emitting layer, the organic EL device of the present invention has at least one layer selected from the group consisting of a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer as a functional layer. It is preferable. In one embodiment, it is preferable to include at least one of a hole injection layer and a hole transport layer. Hereinafter, typical functional layers will be described.
(Hole injection layer, hole transport layer)
In the present invention, at least one of the hole injection layer and the hole transport layer is preferably configured as an organic layer containing the charge transport material of the present invention. In one embodiment, the organic EL element preferably has at least a hole transport layer as the functional layer, and the hole transport layer is preferably configured as an organic layer containing the charge transport material. In this embodiment, the hole transport layer can be easily formed by applying an ink composition containing the charge transport material. In such an embodiment, when a hole injection layer is used in combination, the hole injection layer is not particularly limited and can be formed using a material well known in the art. In one embodiment, the hole injection layer can be easily formed by applying an ink composition containing a charge transporting material having a triarylamine structure, for example. In one embodiment of the present invention, the coating film is cured in the formation of the hole injection layer, and the ink composition containing the charge transporting material of the present invention is subsequently applied onto the coating film, thereby forming a charge. Lamination of the injection layer / charge transport layer can be easily performed.

(Electron transport layer, electron injection layer)
The electron transport layer and the electron injection layer can be formed according to methods well known in the art. Examples of materials that can be used to form the electron transport layer and / or the electron injection layer include, for example, phenanthroline derivatives (for example, 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)). , Bipyridine derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole Derivatives (2- (4-Biphenylyl) -5- (4-tert-butylphenyl-1,3,4-oxadiazole) (PBD)), aluminum complexes (eg Tris (8-hydroxyquinolinato) aluminum (III) (Alq ₃ )). Furthermore, in the oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, or a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can be used.

(substrate)
The kind of board | substrate which can be used for an organic EL element is not specifically limited, You may be board | substrates, such as glass and a resin film. As one embodiment, it is preferable to use a flexible substrate known in the art as a flexible substrate. As an example of the flexible substrate, a substrate including at least one selected from the group consisting of thin film glass, aluminum foil, and resin film can be given. The substrate is preferably transparent. From such a viewpoint, for example, a glass substrate, a quartz substrate, or a substrate including a light-transmitting resin film is preferable. Among these, when a light-transmitting resin film is used as the substrate, it is particularly preferable because it is not only excellent in transparency but also easy to impart flexibility to the organic EL element.

  Examples of the resin film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), and cellulose. Examples include films made of triacetate (TAC), cellulose acetate propionate (CAP), and the like.

  In the case of using the 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 or oxygen. Moreover, the said resin film may be used independently, or may be used in multiple layers combining multiple.

(Sealing)
The organic EL element may be sealed in order to reduce the influence of outside air and extend the life. As a material used for sealing, glass, epoxy resin, acrylic resin, plastic films such as PET and PEN, and inorganic materials such as silicon oxide and silicon nitride can be used.

  The sealing method is not particularly limited. For example, a method of directly forming on an organic EL element by vacuum deposition, sputtering, coating method, or the like, a method of bonding glass or a plastic film to the organic EL element with an adhesive, or the like. It can be used.

(Luminescent color)
The color of light emitted from the organic EL element is not particularly limited, but the white light-emitting element is preferable because it can be used for various lighting fixtures such as home lighting, interior lighting, clocks, and liquid crystal backlights.

  As a method for forming a white light emitting element, it is currently difficult to emit white light with a single material. Therefore, white light emission is obtained by using a plurality of light-emitting materials to emit a plurality of light emission colors simultaneously and mix the colors. A combination of a plurality of emission colors is not particularly limited. However, a combination of three emission maximum wavelengths of blue, green, and red, a complementary color relationship such as blue and yellow, yellow green and orange is used. The thing containing two light emission maximum wavelengths is mentioned. The emission color can be controlled by adjusting the type and amount of the phosphorescent material.

<Display element, lighting device, display device>
One embodiment of the present invention relates to a display element including the organic EL element. For example, a color display element can be obtained by using the organic EL element as an element corresponding to each pixel of red, green, and blue (RGB). Image formation includes 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 thin film transistors are arranged and driven in each element. The former is simple in structure but has a limit on the number of vertical pixels and is used for displaying characters. The latter is used for high-quality displays because the drive voltage is low and the current is small, and a bright high-definition image is obtained.

Another embodiment of the present invention relates to a lighting device including the above organic EL element. Further, one embodiment of the present invention relates to a display device including the above lighting device and a liquid crystal element as display means.
For example, the illumination device may be used as a backlight (white light-emitting light source), and a display device using a liquid crystal element as a display unit, that is, a liquid crystal display device may be configured. Such a configuration is a configuration in which only the backlight is replaced with the above-described lighting device in a known liquid crystal display device, and a known technique can be diverted to the liquid crystal element portion.

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

<1> Preparation of polymer compound (Preparation of Pd catalyst)
In a glove box under a nitrogen atmosphere, tris (dibenzylideneacetone) dipalladium (73.2 mg, 80 μmol) was weighed into a sample tube at room temperature, anisole (15 ml) was added, and the mixture was stirred for 30 minutes. Similarly, tris (t-butyl) phosphine (129.6 mg, 640 μmol) was weighed in a sample tube, anisole (5 mL) was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at room temperature for 30 minutes to obtain a catalyst solution. In preparing the catalyst, all solvents were used after degassing with nitrogen bubbles for 30 minutes or more.

Preparation Example 1 Polymer Compound 1
The charge transporting polymer compound 1 was prepared as follows. The polymer compound 1 is a compound that does not contain a structural unit derived from a condensed polycyclic aromatic hydrocarbon.
The following monomer 1 (4.0 mmol), the following monomer 2 (5.0 mmol), the following monomer 3 (2.0 mmol), and anisole (20 mL) were added to a three-necked round bottom flask, and a separately prepared Pd catalyst solution (7.5 mL) was added and stirred. After stirring for 30 minutes, a 10% tetraethylammonium hydroxide aqueous solution (20 mL) was added to the flask. The mixture was heated to reflux for 2 hours. All the operations so far were performed under a nitrogen stream. All the solvents were used after deaeration with nitrogen bubbles for 30 minutes or more.

After completion of the reaction, the organic layer was washed with water. The organic layer was then poured into methanol-water (9: 1). The resulting precipitate was suction filtered and washed with methanol-water (9: 1). The washed precipitate was dissolved in toluene and reprecipitated from methanol. The obtained precipitate was filtered by suction, dissolved in toluene, and added with triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer (Strem Chemicals, 200 mg per 100 mg of polymer, hereinafter referred to as “metal adsorbent”). Stir overnight.
After completion of the stirring, the metal adsorbent and insoluble matter were removed by filtration, and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in toluene and then reprecipitated from methanol-acetone (8: 3). The resulting precipitate was filtered by suction and washed with methanol-acetone (8: 3).
The resulting precipitate was vacuum-dried to prepare polymer compound 1. The number average molecular weight of the obtained polymer compound 1 was 7,800, and the weight average molecular weight was 31,000. The molecular weight was measured by GPC (polystyrene conversion) using THF as an eluent.

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

(Preparation Example 2-polymer compound 2)
The charge transporting polymer compound 2 was prepared as follows. The polymer compound 2 is a compound that does not contain a structural unit derived from a condensed polycyclic aromatic hydrocarbon.
Monomer 2 (5.0 mmol) and monomer 3 (2.0 mmol) described in Preparation Example 1, monomer 4 (4.0 mmol), and anisole (20 ml) described in Preparation Example 1 were added to a three-necked round bottom flask. The Pd catalyst solution (7.5 ml) was added and stirred. Thereafter, polymer compound 2 was prepared in the same manner as described in Preparation Example 1. The number average molecular weight of the obtained polymer compound 2 was 22,900, and the weight average molecular weight was 169,000.

(Preparation Example 3-polymer compound 3)
The charge transporting polymer compound 3 was prepared as follows. The polymer compound 3 is a compound having a structural unit having three or more branched parts and derived from a condensed polycyclic aromatic hydrocarbon.
In a three-necked round bottom flask, monomer 2 (5.0 mmol) described in Preparation Example 1, monomer 4 (3.5 mmol) described in Preparation Example 2, monomer 5 (1.5 mmol) below, anisole (20 ml), Further, a separately prepared Pd catalyst solution (7.5 ml) was added and stirred. Thereafter, polymer compound 3 was prepared in the same manner as described in Preparation Example 1. The number average molecular weight of the obtained polymer compound 3 was 3,300, and the weight average molecular weight was 30,600. In the polymer compound 3, the proportion of each structural unit derived from each monomer was monomer 5:15 mol%, monomer 2:50 mol%, and monomer 4:35 mol%.

(Preparation Example 4—Polymer Compound 4)
The charge transporting polymer compound 4 was prepared as follows. The polymer compound 4 is a compound that includes a structural unit derived from a condensed polycyclic aromatic hydrocarbon but does not have a branched structure that branches in three or more directions.
In a three-necked round bottom flask, monomer 2 (5.0 mmol) described in Preparation Example 1, monomer 6 (4.0 mmol) shown below, monomer 4 (2.0 mmol) described in Preparation Example 2, and anisole (20 ml) And a separately prepared Pd catalyst solution (7.5 ml) was added and stirred. Thereafter, polymer compound 4 was prepared in the same manner as described in Preparation Example 1. The number average molecular weight of the obtained polymer compound 4 was 2,500, and the weight average molecular weight was 10,400.

(Preparation Example 5-Polymer compound 5)
The charge transporting polymer compound 5 was prepared as follows. The polymer compound 5 is a compound having three or more branches, including a structural unit derived from a condensed polycyclic aromatic hydrocarbon, and further having a polymerizable substituent.
In a three-necked round bottom flask, monomer 2 (5.0 mmol), monomer 1 (1.0 mmol) described in Preparation Example 1, monomer 5 (2.0 mmol) described in Preparation Example 3, and Monomer 4 (3.0 mmol) and anisole (20 ml) were added, and a separately prepared Pd catalyst solution (7.5 ml) was added and stirred. Thereafter, polymer compound 5 was prepared in the same manner as described in Preparation Example 1. The number average molecular weight of the obtained polymer compound 5 was 40,100, and the weight average molecular weight was 232,000.

(Preparation Example 6 polymer compound 6)
A charge transporting polymer compound 6 was prepared as follows. The polymer compound 6 includes a structural unit derived from a condensed polycyclic aromatic hydrocarbon, but does not have a branched structure that branches in three or more directions.
In a three-necked round bottom flask, monomer 2 (5.0 mmol) described in Preparation Example 1, monomer 6 (4.0 mmol) described in Preparation Example 4, monomer 1 (2.0 mmol) described in Preparation Example 1 and Then, anisole (20 ml) was added, and a separately prepared Pd catalyst solution (7.5 ml) was added and stirred. Thereafter, polymer compound 4 was prepared in the same manner as described in Preparation Example 1. The number average molecular weight of the obtained polymer compound 6 was 5,200, and the weight average molecular weight was 8,000.

<2-1> Preparation of organic EL element (Example 1)
Ink composition 1 comprising polymer compound 1 (10.0 mg) obtained in Preparation Example 1, the following ionic compound (I) (0.5 mg), and toluene (2.3 mL) was prepared. Next, in a nitrogen atmosphere, the ink composition ¹ was spin-coated at 3000 min ⁻¹ on a glass substrate (thickness 0.7 mm) obtained by patterning ITO to a width of 1.6 mm, and subsequently 220 on a hot plate. C. for 10 minutes to cure and form a hole injection layer (30 nm).

Next, an ink composition 3 composed of the polymer compound 3 (20 mg) obtained in Preparation Example 3, the ionic compound (I) (1.0 mg), and toluene (2.3 mL) was prepared. On the formed hole injection layer, spin coating was performed at 3000 min ⁻¹ . Subsequently, it was dried by heating at 180 ° C. for 10 minutes on a hot plate to form a hole transport layer (40 nm). Here, the formation of the hole transport layer was successfully carried out without dissolving the hole injection layer.

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

(Comparative Example 1)
Ink composition 2 comprising polymer compound 2 (20 mg) obtained in Preparation Example 2, the ionic compound (I) (1.0 mg) described in Example 1 and toluene (2.3 mL). Was prepared. In Example 1, the same procedure as in Example 1 was conducted except that the ink composition 2 was used instead of the ink composition 3 used for forming the hole transport layer of the organic EL device. An EL element was produced.

(Comparative Example 2)
An ink composition 4 comprising the polymer compound 4 (20 mg) obtained in Preparation Example 4, the ionic compound (I) (1.0 mg) described in Example 1, and toluene (2.3 mL) was prepared. Prepared. In Example 1, the same procedure as in Example 1 was conducted except that the ink composition 4 was used instead of the ink composition 3 used to form the hole transport layer of the organic EL device. An EL element was produced.

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

  As can be seen from Table 1, the organic EL device of Example 1 had a driving voltage lower than that of Comparative Examples 1 and 2, an excellent luminous efficiency, and a long luminous lifetime. That is, from the viewpoint of the constituent material of the hole transport layer, by using a polymer compound having a specific branched structure derived from a polycyclic aromatic hydrocarbon compound in the molecule as the charge transport material, It can be seen that special effects such as improvement in luminous efficiency and luminous lifetime can be obtained.

<3-1> Production of white organic EL element (illumination device) (Example 2)
In the same manner as in Example 1, ink composition 1 comprising polymer compound 1 (10.0 mg), ionic compound (I) (0.5 mg), and toluene (2.3 mL) was prepared. Next, in a nitrogen atmosphere, the ink composition ¹ was spin-coated at 3000 min ⁻¹ on a glass substrate (thickness 0.7 mm) obtained by patterning ITO to a width of 1.6 mm, and subsequently 220 on a hot plate. C. for 10 minutes to cure and form a hole injection layer (30 nm).

Next, an ink composition 5 consisting of polymer compound 5 (20 mg), ionic compound (I) (1.0 mg), and toluene (2.3 mL) was prepared in the same manner as Example 1. On the hole injection layer formed previously, spin coating was performed at 3000 min ⁻¹ . Subsequently, the film was dried by heating at 200 ° C. for 10 minutes on a hot plate to form a hole transport layer (40 nm).
Here, the formation of the hole transport layer was successfully carried out without dissolving the hole injection layer.

Next, on the glass substrate / hole injection layer / hole transport layer laminate obtained as described above, CDBP (15 mg), FIr (pic) (0.9 mg), Ir (in nitrogen) a mixture of (ppy) ₃ (0.9 mg), (btp) ₂ Ir (acac) (1.2 mg), and dichlorobenzene (0.5 mL) is spin-coated at 3000 min ⁻¹ and then at 80 ° C. for 5 It was made to dry for minutes and the light emitting layer (40 nm) was formed. Here, the formation of the light emitting layer could be carried out satisfactorily without dissolving the hole transport layer.

Further, by performing film formation by vapor deposition in the order of BAlq (10 nm), Alq ₃ (30 nm), LiF (0.5 nm), and Al (100 nm), a hole blocking layer and an electron transport layer are formed on the light emitting layer. A layer, an electron injection layer, and a cathode were sequentially laminated. After laminating the cathode by vapor deposition of Al as described above, the laminate was moved into a dry nitrogen environment without opening to the atmosphere, and sealing was performed by adding 0.4 mm counterbore to 0.7 mm non-alkali glass. Sealing was performed by bonding the glass and the ITO glass substrate of the above laminate using a photocurable epoxy resin to produce a white organic EL element. The obtained white organic EL element could be used as a lighting device.

(Comparative Example 3)
An ink composition 6 comprising the polymer compound 6 (20 mg) obtained in Preparation Example 6, the ionic compound (I) described in Example 1 (1.0 mg), and toluene (2.3 mL) was prepared. . In Example 2, except that the ink composition 6 was used instead of the ink composition 5 used for forming the hole transport layer of the white organic EL device, all were the same as in Example 2, A white organic EL device was obtained.

<3-2> Evaluation of white organic EL element (illumination device) Voltage was applied to each white organic EL element obtained in Example 2 and Comparative Example 3 to obtain a light emission lifetime at an initial luminance of 1000 cd / m ^2. It was measured. When the driving voltage, luminous efficiency, and luminous lifetime of Example 2 were set to 1, in Comparative Example 3, the driving voltage was 1.2, the luminous efficiency was 0.8, and the luminous life was 0.3.

  That is, the white organic EL element of Example 2 has a low driving voltage and excellent light emission efficiency and light emission lifetime in comparison with the white organic EL element of Comparative Example 3. From these results, as in Example 1, as a charge transport material constituting the hole transport layer, a polymer compound having a specific branched structure derived from a condensed polycyclic aromatic hydrocarbon compound in the molecule was used. It turns out that special effects, such as an improvement of luminous efficiency and luminous lifetime, are acquired by using.

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

Claims (24)

A charge transporting material comprising a polymer compound having a branched structure branched in three or more directions and having a charge transporting property,
A first structural unit in which the polymer compound is derived from a condensed polycyclic aromatic hydrocarbon having three or more conjugated aromatic rings in the molecule and having three or more branched parts; and the first structure A charge transporting material comprising at least one structure having at least three second structural units having charge transporting properties bonded to the branched portion of the unit.   The charge transport material according to claim 1, wherein the first structural unit includes a structure derived from a condensed polycyclic aromatic hydrocarbon having 3 to 6 aromatic rings in the molecule.   The first structural unit is at least one condensation selected from the group consisting of anthracene, tetracene, pentacene, phenanthrene, chrysene, triphenylene, tetraphen, pyrene, picene, pentaphen, perylene, helicene, coronene anthracene, and tetracene. The charge transporting material according to claim 1, comprising a structure derived from a polycyclic aromatic hydrocarbon.   The charge transport material according to claim 3, wherein the first structural unit includes a structure derived from pyrene.   The charge transport material according to claim 1, wherein the second structural unit has a triphenylamine structure.   The charge transport material according to claim 1, wherein the first structural unit includes a structure derived from pyrene, and the second structural unit includes a structure derived from triphenylamine.   The charge transport material according to claim 1, wherein the polymer compound has one or more polymerizable substituents in the molecule.   The charge transport material according to claim 7, wherein the polymer compound includes a third structural unit having a polymerizable substituent in addition to the first and second structural units.   The charge transporting material according to claim 8, wherein the third structural unit has a benzene ring structure.   The polymerizable substituent is a group having a carbon-carbon multiple bond, a group having a small ring, a lactone group, a lactam group, a group containing a siloxane derivative, an oxetane group, an epoxy group, a vinyl group, a vinyl ether group, or an acrylate group. And at least one group selected from the group consisting of a methacrylate group, or a combination of an ester group and an amino group, or a combination of an ester group and a hydroxyl group. Charge transport material.   The charge transporting material according to claim 10, wherein the polymerizable substituent includes an oxetane group.   The charge transport material according to any one of claims 9 to 11, wherein the polymerizable substituent is bonded to the benzene ring structure via an alkyl chain having 1 to 8 carbon atoms.   The charge transporting material according to claim 7, wherein the polymerizable substituent is bonded to a hydrophilic group. The polymer compound is a polymer compound (A) obtained by reacting the following monomer 2, the following monomer 4, and the following monomer 5, or the following monomer 1, the following monomer 2, the following monomer 4, and the following The charge transport material according to any one of claims 7 to 13, which is a polymer compound (B) obtained by reacting the monomer 5.

  The polymer compound (A) is a compound obtained by a reaction at a molar ratio of monomer 2: monomer 4: monomer 5 = 5.0: 3.5: 1.5, and the polymer compound (B) is The charge transport property according to claim 14, which is a compound obtained by a reaction at a molar ratio of monomer 1: monomer 2: monomer 4: monomer 5 = 1.0: 5.0: 3.0: 2.0. material.   The charge transport material according to claim 1, which is used as a hole transport material.   An ink composition comprising the charge transporting material according to claim 1 and a solvent.   The organic electronics element which has an organic layer containing the electric charge transport material of any one of Claims 1-15.   The organic electroluminescent element which has an organic layer containing the charge transport material of any one of Claims 1-15.   The organic electroluminescent element according to claim 19, further comprising a flexible substrate.   The organic electroluminescent element according to claim 20, wherein the flexible substrate includes a resin film.   The display element provided with the organic electroluminescent element of any one of Claims 19-21.   The illuminating device provided with the organic electroluminescent element of any one of Claims 19-21.   A display device comprising the illumination device according to claim 23 and a liquid crystal element as display means.

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