Charge transport material, ink composition, organic layer, organic electronic element, organic electroluminescence element, lighting device, display element, and display device

Abstract

To provide a charge transport material and an ink composition suitable for a coating process and capable of forming an organic layer having excellent solvent resistance, to provide an organic layer suitable for improving the characteristics of an organic electronic element, and to provide an organic electronic element, an organic EL element, a display element, a lighting device, and a display device having excellent characteristics.SOLUTION: A charge transport material includes a first polymer having a first polymerizable substituent and a second polymer having a second polymerizable substituent different from the first polymerizable substituent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to a charge transport material, an ink composition, an organic layer, an organic electronics device, an organic electroluminescence device (also referred to as an "organic EL device"), a lighting device, a display device, and a display apparatus. [Background technology]

[0002] Organic electroluminescent (EL) devices are attracting attention as large-area solid-state light sources, replacing incandescent lamps, gas-filled lamps, etc. They are also attracting attention as a promising self-emissive display to replace liquid crystal displays (LCDs) in the field of flat panel displays (FPDs), and commercialization of these devices is progressing.

[0003] Organic EL devices are broadly divided into two types based on the organic materials used: low-molecular-weight organic EL devices that use low-molecular-weight compounds, and polymer-type organic EL devices that use polymer compounds. Manufacturing methods for organic EL devices are broadly divided into dry processes, in which films are formed primarily in a vacuum system, and coating processes, in which films are formed by plate printing such as relief printing and intaglio printing, or plateless printing such as inkjet printing. Because coating processes enable simple film formation, they are expected to become an essential method for future large-screen organic EL displays. For example, Patent Document 1 discloses an organic electronics material containing a polymer or oligomer with a structure that branches in three directions.

[0004] Furthermore, in order to improve the efficiency and / or extend the life of organic EL devices, attempts have been made to form multiple organic layers and separate the functions of each layer. For example, Patent Document 2 discusses a method of using a compound having at least one polymerizable group to form multiple organic layers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2010 / 140553 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-279007 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the coating process, where multiple layers are formed using an ink composition, a problem may arise in that when the upper layer is applied, the lower layer is dissolved by the solvent contained in the upper layer.

[0007] In view of the above, an object of an embodiment of the present invention is to provide a charge transport material and an ink composition that are suitable for a coating process and that can form an organic layer that is excellent in solvent solubility resistance (hereinafter also referred to as "solvent resistance"). Another object of another embodiment of the present invention is to provide an organic layer that is suitable for improving the properties of organic electronic elements. Another object of another embodiment of the present invention is to provide an organic electronic element, an organic EL element, a display element, a lighting device, and a display device that have excellent properties. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to achieve the above object and have found that an organic layer formed using a charge transport material containing two or more polymers having different polymerizable substituents exhibits excellent solvent resistance.

[0009] Examples of embodiments of the present invention are listed below, but the present invention is not limited to the following embodiments.

[0010] (1) A charge transport material comprising a first polymer having a first polymerizable substituent and a second polymer having a second polymerizable substituent different from the first polymerizable substituent.

[0011] (2) The charge transport material according to (1), wherein the first polymerizable substituent comprises the following structure: *-Ar-(CH2) n -CH=CH2 In the above structures, * represents a bonding site to other structures, Ar represents a substituted or unsubstituted arylene group or heteroarylene group, and n is an integer of 0-20.

[0012] (3) The charge transporting material according to (2), wherein Ar is a substituted or unsubstituted phenylene group.

[0013] (4) The charge transport material according to any one of (1) to (3), wherein the second polymerizable substituent includes at least one selected from the group consisting of a cyclopropyl group, a cyclobutyl group, a benzocyclobutenyl group, an epoxy group, and an oxetanyl group.

[0014] (5) The charge transport material according to any one of (1) to (4), wherein the second polymerizable substituent contains a benzocyclobutenyl group.

[0015] (6) An ink composition comprising the charge transport material according to any one of (1) to (5) above and a solvent.

[0016] (7) An organic layer formed using the charge transport material according to any one of (1) to (5) or the ink composition according to (6).

[0017] (8) An organic electronic device comprising at least one organic layer according to (7).

[0018] (9) An organic electroluminescence device comprising at least one organic layer according to (7).

[0019] (10) The organic electroluminescence device according to (9), further comprising a flexible substrate.

[0020] (11) The organic electroluminescence element according to (9), further comprising a resin film substrate.

[0021] (12) A display device comprising the organic electroluminescence device according to any one of (9) to (11).

[0022] (13) A lighting device comprising the organic electroluminescence element according to any one of (9) to (11).

[0023] (14) A display device comprising the organic electroluminescence element according to any one of (9) to (11).

[0024] (15) A display device comprising the display device according to (14) and a liquid crystal element as a display means. [Effects of the Invention]

[0025] According to an embodiment of the present invention, a charge transport material and an ink composition can be provided that are suitable for a coating process and can form an organic layer that has excellent solvent resistance. Furthermore, according to another embodiment of the present invention, an organic layer that is suitable for improving the properties of organic electronic devices can be provided. According to another embodiment of the present invention, an organic electronic device, an organic EL device, a display device, a lighting device, and a display device that have excellent properties can be provided. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of an organic EL element according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

[0028] <Charge transport material> The charge transport material according to this embodiment contains two or more charge transport polymers having different polymerizable substituents. Specifically, the charge transport material contains at least a charge transport polymer having a first polymerizable substituent (hereinafter also referred to as a "first polymer") and a charge transport polymer having a second polymerizable substituent different from the first polymerizable substituent (hereinafter also referred to as a "second polymer"). The charge transport material may contain two or more first polymers and two or more second polymers. The charge transport material may further contain a charge transport polymer other than the first polymer and the second polymer. In other words, the charge transport material may further contain a charge transport polymer that does not contain a polymerizable substituent.

[0029] [Charge-transporting polymer] The first polymer and the second polymer (hereinafter collectively referred to as "charge transporting polymers") will be described below. Charge-transporting polymers have the ability to transport charges. The term "polymer" includes so-called "oligomers," which have a small number of repeating structural units.

[0030] [Charge-transporting polymer structure] Examples of partial structures contained in the charge transport polymer include the following. The charge transport polymer is not limited to polymers having the following partial structures. In the partial structures, "L" represents a divalent structural unit L, "T" represents a monovalent structural unit T, and "B" represents a trivalent or higher structural unit B. In the partial structures contained in the charge transport polymer shown below, "*" in the formula represents a bonding site with another structural unit. In the partial structures below, multiple Ls may be the same structural unit or different structural units. The same applies to T and B.

[0031] Linear charge-transporting polymer

[0032] [ka]

[0033] Charge-transporting polymers with branched structures

[0034] [ka]

[0035] (Structural unit L) The structural unit L is a divalent structural unit having charge transport properties. The structural unit L is not particularly limited as long as it contains an atomic group capable of transporting a charge. For example, the structural unit L is selected from substituted or unsubstituted aromatic amine structures, carbazole structures, thiophene structures, fluorene structures, benzene structures, biphenylene structures, terphenylene structures, naphthalene structures, anthracene structures, tetracene structures, phenanthrene structures, dihydrophenanthrene structures, pyridine structures, pyrazine structures, quinoline structures, isoquinoline structures, quinoxaline structures, acridine structures, diazaphenanthrene structures, furan structures, pyrrole structures, oxazole structures, oxadiazole structures, thiazole structures, thiadiazole structures, triazole structures, benzothiophene structures, benzoxazole structures, benzoxadiazole structures, benzothiazole structures, benzothiadiazole structures, benzotriazole structures, and structures containing one or more of these. The aromatic amine structure is preferably a triarylamine structure, and more preferably a triphenylamine structure.

[0036] In one embodiment, from the viewpoint of obtaining excellent hole transport properties, the structural unit L is preferably selected from a substituted or unsubstituted aromatic amine structure, a carbazole structure, a thiophene structure, a fluorene structure, a benzene structure, a pyrrole structure, and structures containing one or more of these, and more preferably selected from a substituted or unsubstituted aromatic amine structure, a carbazole structure, a thiophene structure, and structures containing one or more of these. From the viewpoint of obtaining excellent electron transport properties, the structural unit L is preferably selected from a substituted or unsubstituted fluorene structure, a benzene structure, a phenanthrene structure, a pyridine structure, a quinoline structure, and structures containing one or more of these.

[0037] Specific examples of the structural unit L include the following: The structural unit L is not limited to the following.

[0038] [ka]

[0039] [ka]

[0040] Each R independently represents a hydrogen atom or a substituent. All R may be hydrogen atoms. When R is a substituent, each R independently represents a -R 1 , -OR 2 , -SR 3 , -OCOR 4 , -COOR 5 , -SiR 6 R 7 R 8 , a halogen atom, and a group containing a polymerizable substituent, as described below. 1 ~R 8 each independently represents a hydrogen atom; a linear, cyclic, or branched alkyl group having 1 to 22 carbon atoms; or an aryl or heteroaryl group having 2 to 30 carbon atoms. The alkyl group may be further substituted with an aryl or heteroaryl group having 2 to 20 carbon atoms, and the aryl or heteroaryl group may be further substituted with a linear, cyclic, or branched alkyl group having 1 to 22 carbon atoms. R is preferably a hydrogen atom, an alkyl group, an aryl group, or an alkyl-substituted aryl group. Ar represents an arylene or heteroarylene group having 2 to 30 carbon atoms.

[0041] Specific examples of the aromatic hydrocarbon contained in the arylene group and the aromatic heterocycle contained in the heteroarylene group are the same as those described for the aryl group and heteroaryl group.

[0042] The structural unit L may be, for example, the following structural unit (1).

[0043] [ka]

[0044] In the structural unit (1), * denotes a bonding site to other structures, and each Ar independently represents a substituted or unsubstituted aryl group or arylene group. Two Ar may bond together to form a ring.

[0045] An aryl group is an atomic group formed by removing one hydrogen atom from an aromatic hydrocarbon. An arylene group is an atomic group formed by removing two hydrogen atoms from an aromatic hydrocarbon. Examples of aromatic hydrocarbons contained in aryl and arylene groups include benzene, naphthalene, anthracene, tetracene, fluorene, and phenanthrene.

[0046] Each Ar is preferably a substituted or unsubstituted phenyl group or phenylene group, a substituted or unsubstituted naphthyl group or naphthylene group, or a substituted or unsubstituted anthracenyl group or anthrylene group, and more preferably a substituted or unsubstituted phenyl group or phenylene group, or a substituted or unsubstituted naphthyl group or naphthylene group.

[0047] The structural unit (1) is preferably a structural unit such as that shown in the following structural formula:

[0048] [ka]

[0049] In the structural unit (1a), * represents a bonding site to another structure, and R represents a hydrogen atom or a substituent. In the structural unit (1a), at least one R has an electron-withdrawing group as a substituent. The substituents in the structural unit (1a) are each independently -R 1 , -OR 2 , -SR 3 , -OCOR4 , -COOR 5 , -SiR 6 R 7 R 8 and halogen atoms. 1 ~R 8 are each independently a hydrogen atom or at least one selected from the group consisting of linear, cyclic, or branched alkyl groups, alkenyl groups, alkynyl groups, and alkoxy groups having 1 to 22 carbon atoms, and aryl groups and heteroaryl groups having 2 to 30 carbon atoms. A heteroaryl group refers to an atomic group obtained by removing one hydrogen atom from an aromatic heterocycle. The aryl group and heteroaryl group may further have a substituent. The substituent is preferably a linear, cyclic, or branched alkyl group having 1 to 22 carbon atoms, or a heteroaryl group having 2 to 30 carbon atoms.

[0050] Examples of the electron-withdrawing group include a cyano group, a nitro group, an alkylsulfonyl group (e.g., a methylsulfonyl group), an arylsulfonyl group (e.g., a phenylsulfonyl group), a halogen atom, a halogenated alkyl group, etc. Specific examples of the aromatic heterocycle include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, and benzothiophene.

[0051] In the structural unit (1a), a1 represents an integer of 0 to 5, and a2 and a3 each independently represent an integer of 0 to 4. From the viewpoint of ease of bonding with other structures, a2 and a3 are preferably 0.

[0052] Furthermore, in the structural unit (1a), a1 is 1 or more, and (R) a1In the formula, R is preferably an electron-withdrawing group, and preferably contains, for example, a fluoro group or a fluoroalkyl group, which is an electron-withdrawing group. Furthermore, R is preferably at least one structural unit selected from the group consisting of the following structural units (1b) to (1e) containing a fluoro group or a perfluoromethyl group.

[0053] [ka]

[0054] (Structural unit T) The structural unit T is a monovalent structural unit that constitutes the terminal portion of the charge transporting polymer. The structural unit T is not particularly limited and may be selected from, for example, a substituted or unsubstituted aromatic hydrocarbon structure, an aromatic heterocyclic structure, and a structure containing one or more of these. The structural unit T may have the same structure as the structural unit L. In one embodiment, from the viewpoint of imparting durability without reducing charge transportability, the structural unit T is preferably a substituted or unsubstituted aromatic hydrocarbon structure, and more preferably a substituted or unsubstituted benzene structure. The structural unit T may have the same structure as the structural unit L except for the valence, or may have a different structure.

[0055] Specific examples of the structural unit T include the following: The structural unit T is not limited to the following.

[0056] [ka]

[0057] In the structural unit (2-1), * represents a bonding site to other structures, and each R independently represents a halogen atom or a halogenated alkyl group. The halogenated alkyl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2. The halogenated alkyl group is preferably a perhalogenated alkyl group, and more preferably a fluoroalkyl group or perfluoroalkyl group in which the halogen atom is a fluorine atom.

[0058] The two R's may be the same or different, and are preferably the same. Each R is more preferably a fluoroalkyl group, and more preferably a perfluoroalkyl group having 1 to 4 carbon atoms.

[0059] In the structural unit (2-2), * represents a bonding site to other structures, and R each independently represents a hydrogen atom or a linear alkyl group, with at least one R being a linear alkyl group. The linear alkyl group preferably has 4 to 20 carbon atoms, more preferably 4 to 16 carbon atoms, and even more preferably 4 to 12 carbon atoms.

[0060] The structural unit (2-1) is preferably, for example, the following structural unit (2a-1).

[0061] [ka]

[0062] In the structural unit (2a-1), m and n each independently represent an integer of 1 to 4. m and n may be the same or different, and are preferably the same.

[0063] The structural unit (2a-1) is particularly preferably the following structural unit (2b-1).

[0064] [ka]

[0065] The structural unit (2-2) is preferably, for example, the following structural unit (2a-2).

[0066] [ka]

[0067] In the structural unit (2a-2), n represents an integer of 4 to 20. From the viewpoint of improving life characteristics, n is preferably 4 to 7. From the viewpoint of improving solubility, n is preferably 9 to 20. In consideration of the balance between improving life characteristics and improving solubility, n may be 4 to 16 or 4 to 12.

[0068] The structural unit (2a-2) is particularly preferably the following structural unit (2b-2).

[0069] [ka]

[0070] (Structural unit B) When the charge-transporting polymer has a branched structure, the structural unit B is a trivalent or higher structural unit that constitutes the branched portion. From the viewpoint of improving the durability of the organic electronic device, the structural unit B is preferably a hexavalent or lower structural unit, more preferably a trivalent or tetravalent structural unit. The structural unit B is preferably a unit having charge transport properties. For example, from the viewpoint of improving the durability of the organic electronic device, the structural unit B is selected from a substituted or unsubstituted aromatic amine structure, a carbazole structure, a fused polycyclic aromatic hydrocarbon structure, and a structure containing one or more of these. The structural unit B may have the same structure as the structural unit L or a different structure other than the valence, and may also have the same structure as the structural unit T or a different structure.

[0071] Specific examples of the structural unit B include the following: The structural unit B is not limited to the following.

[0072] [ka]

[0073] W represents a trivalent linking group, for example, an arenetriyl group or heteroarenetriyl group having 2 to 30 carbon atoms. An arenetriyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic hydrocarbon. A heteroarenetriyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic heterocycle. Ar each independently represent a divalent linking group, for example, 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, a divalent group obtained by removing one more hydrogen atom from a group having one or more hydrogen atoms among the substituents exemplified as R in the structural unit L (excluding groups containing a polymerizable substituent). Z represents a carbon atom, a silicon atom, or a phosphorus atom. In the structural unit, the fused ring, W, Y, and Ar may have a substituent, and examples of the substituent include the substituents exemplified as R in the structural unit L.

[0074] The structural unit B may be, for example, the following structural units (3-1) and (3-2) (hereinafter collectively referred to as structural unit (3)).

[0075] [ka]

[0076] In the structural units (3-1) and (3-2), * represents a bonding site with other structures, Ar represents a substituted or unsubstituted arylene group, and R represents a hydrogen atom or a substituent. The substituents in R in the structural units (3-1) and (3-2) are each independently -R 1 , -OR 2 , -SR 3 , -OCOR 4 , -COOR 5 , -SiR 6 R 7 R 8 and halogen atoms. 1 ~R 8are each independently a hydrogen atom or at least one selected from the group consisting of linear, cyclic, or branched alkyl groups, alkenyl groups, alkynyl groups, and alkoxy groups having 1 to 22 carbon atoms, and aryl groups and heteroaryl groups having 2 to 30 carbon atoms. The aryl groups and heteroaryl groups may further have a substituent. The substituent is preferably a linear, cyclic, or branched alkyl group having 1 to 22 carbon atoms, or a heteroaryl group having 2 to 30 carbon atoms.

[0077] In the structural units (3-1) and (3-2), b2 and b3 each independently represent an integer of 0 to 4, and b5 and b6 each independently represent an integer of 0 to 3. From the viewpoint of ease of bonding with other structures, b2, b3, b5, and b6 are preferably 0.

[0078] The structural units (3-1) and (3-2) are preferably structural units such as those shown in the following structural formulas.

[0079] [ka]

[0080] In the structural units (3a-1) and (3a-2), * represents a bonding site to other structures, and R represents a hydrogen atom or a substituent, and the substituents each independently represent the above-mentioned -R 1 , -OR 2 , -SR 3 , -OCOR 4 , -COOR 5 , -SiR 6 R 7 R 8 and halogen atoms.

[0081] In the structural units (3a-1) and (3a-2), b1 to b4 each independently represent an integer of 0 to 4, and b5 and b6 each independently represent an integer of 0 to 3. From the viewpoint of ease of bonding with other structures, b1 to b6 are preferably 0.

[0082] The structural unit (3a-1) is preferably, for example, the following structural unit (3b-1).

[0083] [ka]

[0084] The structural unit (3a-2) is preferably, for example, the following structural unit (3b-2).

[0085] [ka]

[0086] [Content of each structural unit]

[0087] From the viewpoint of adjusting the energy level, the content of the structural unit (1) is preferably 50 mol % or more, more preferably 75 mol % or more, and even more preferably 90 mol % or more, based on the total amount of the structural units L. The upper limit of the content of the structural unit (1) is 100 mol %.

[0088] From the viewpoint of obtaining sufficient charge transportability, the content of the structural unit L contained in the charge-transporting polymer is preferably 10 mol % or more, more preferably 15 mol % or more, and even more preferably 20 mol % or more, based on all structural units. In addition, the content of the structural unit L is preferably 95 mol % or less, more preferably 90 mol % or less, and even more preferably 85 mol % or less, taking into account the structural units T and B.

[0089] From the viewpoint of obtaining good charge transport properties, the content of the structural unit (2) is preferably 50 mol % or more, more preferably 75 mol % or more, and even more preferably 90 mol % or more, based on the total amount of the structural unit B. The upper limit of the content of the structural unit (2) is 100 mol %.

[0090] The content of the structural unit B contained in the charge-transporting polymer is preferably 1 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on the total structural units, from the viewpoint of obtaining an organic layer having excellent solvent resistance. Furthermore, the content of the trivalent or higher structural unit is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and particularly preferably 20 mol% or less, from the viewpoint of suppressing an increase in viscosity and smoothly synthesizing the charge-transporting polymer, or from the viewpoint of obtaining sufficient charge transportability.

[0091] From the viewpoint of obtaining good storage stability of the liquid composition, the content of the structural unit (3) is preferably 85 mol % or more, more preferably 90 mol % or more, and even more preferably 95 mol % or more, based on the total amount of monovalent structural units. The upper limit of the content of the structural unit (3) is 100 mol %.

[0092] The content of the structural unit T contained in the charge-transporting polymer is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 15 mol % or more, based on all structural units, from the viewpoints of curability and solubility of the charge-transporting polymer and improving the properties of organic electronic devices. Furthermore, the content of the monovalent structural unit is preferably 60 mol % or less, more preferably 55 mol % or less, and even more preferably 50 mol % or less, from the viewpoint of obtaining sufficient charge-transporting properties.

[0093] The ratio (molar ratio) of the contents of the structural unit L, the structural unit B, and the structural unit T contained in the charge-transporting polymer is preferably structural unit L:structural unit B:structural unit T=100:5 to 70:50 to 150, more preferably 100:10 to 60:60 to 135, and even more preferably 100:15 to 50:80 to 120, taking into consideration the balance of the effects of each structural unit.

[0094] (number average molecular weight) The number-average molecular weight of the charge-transporting polymer can be adjusted appropriately taking into consideration solubility in solvents, film-forming properties, etc. From the viewpoint of excellent charge transport properties, the number-average molecular weight is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. Furthermore, from the viewpoint of maintaining good solubility in solvents and facilitating preparation of the ink composition, the number-average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less.

[0095] (Weight average molecular weight) The weight-average molecular weight of the charge-transporting polymer can be adjusted appropriately taking into consideration solubility in a solvent, film-forming properties, etc. From the viewpoint of excellent charge transport properties, the weight-average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, and even more preferably 10,000 or more. Furthermore, from the viewpoint of maintaining good solubility in a solvent and facilitating preparation of an ink composition, the weight-average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, and even more preferably 400,000 or less.

[0096] The number average molecular weight and the weight average molecular weight can be measured by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene.

[0097] (Method for producing charge transport polymer) Charge-transporting polymers can be produced by various synthesis methods, and are not particularly limited. For example, well-known coupling reactions such as Suzuki coupling, Negishi coupling, Sonogashira coupling, Stille coupling, and Buchwald-Hartwig coupling can be used. Suzuki coupling involves a cross-coupling reaction between an aromatic boronic acid derivative and an aromatic halide using a Pd catalyst. Suzuki coupling allows for the easy production of charge-transporting polymers by bonding the desired aromatic rings together.

[0098] In the coupling reaction, catalysts such as Pd(0) compounds, Pd(II) compounds, and Ni compounds are used. Alternatively, catalyst species generated by mixing precursors such as tris(dibenzylideneacetone)dipalladium(0) and palladium(II) acetate with a phosphine ligand can be used. Regarding the synthesis method of charge-transporting polymers, the description in International Publication No. 2010 / 140553 can be cited.

[0099] [First polymer] (Structural unit (4)) The first polymer is the charge-transporting polymer described above, which contains a structural unit (4) having a first polymerizable substituent. The structural unit (4) may be a monovalent structural unit having one bonding site with another structure, a divalent structural unit having two bonding sites with another structure, or a trivalent or higher structural unit having three or more bonding sites with another structure. However, from the viewpoint of achieving both the curability and charge transportability of the charge-transporting polymer, it is preferable that the first polymerizable substituent be contained in a monovalent structural unit.

[0100] [First polymerizable substituent] The first polymerizable substituent has the ability to harden through a polymerization reaction and change the solubility in a solvent. The term "polymerizable substituent" refers to a functional group that can form intramolecular and / or intermolecular bonds with each other by applying heat and / or light.

[0101] Examples of the first polymerizable substituent include a group having a carbon-carbon unsaturated bond (e.g., a vinyl group, an allyl group, a butenyl group, an ethynyl group, an acryloyl group, an acryloyloxy group, an acryloylamino group, a methacryloyl group, a methacryloyloxy group, a methacryloylamino group, a vinyloxy group, a vinylamino group, etc.), a group having a small ring (e.g., a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, etc.; a cycloalkenyl group such as a cyclopropenyl group, a cyclobutenyl group, etc.; a fused ring group such as a benzocyclobutenyl group; a cyclic ether group such as an epoxy group (oxiranyl group), an oxetanyl group, etc.; a diketene group; an episulfide group; a lactone group; a lactam group, etc.), and a group having a heterocycle having a heteroatom (e.g., a furanyl group, a pyrrolyl group, a thiophenyl group, a silolyl group). As the polymerizable substituent, particularly, an ethynyl group, a vinyl group, an acryloyl group, a methacryloyl group, a cyclobutenyl group, an epoxy group, and an oxetanyl group are preferable, and from the viewpoint of transparency and the properties of an organic electronic device, a vinyl group, a cyclobutenyl group, an epoxy group, or an oxetanyl group are more preferable, and from the viewpoint of reactivity, an epoxy group or an oxetanyl group is even more preferable. Furthermore, the above-mentioned group having a carbon-carbon unsaturated bond, the group having a small ring, and the group having a heterocycle having a heteroatom may have a substituent, and for example, it is preferable that the group has an alkyl group.

[0102] From the viewpoint of increasing the degree of freedom of the first polymerizable substituent and facilitating the polymerization reaction, the main skeleton of the charge transport polymer and the polymerizable substituent may be linked by an alkylene chain. Furthermore, for example, when an organic layer described later is formed on an electrode, from the viewpoint of improving affinity with a hydrophilic electrode such as ITO (indium oxide-tin oxide), the main skeleton and the polymerizable substituent may be linked by a hydrophilic chain such as an ethylene glycol chain or a diethylene glycol chain. Furthermore, from the viewpoint of facilitating the preparation of a monomer used to introduce the polymerizable substituent, the charge transport polymer may have an ether bond or an ester bond at the terminal of the alkylene chain and / or the hydrophilic chain, i.e., at the link between these chains and the polymerizable substituent and / or at the link between these chains and the skeleton of the charge transport polymer.

[0103] By introducing the first polymerizable substituent into the terminal portion of the charge transporting polymer, it is possible to achieve both the curability and charge transportability of the charge transporting polymer, which is preferable.

[0104] In this specification, the chain with the highest degree of polymerization among the various chains in one molecule of a charge-transporting polymer is considered to be the main chain. A side chain is a chain different from the main chain of the charge-transporting polymer and has at least one structural unit. Anything other than the side chain is considered a substituent. A terminal substituent attached to the main chain and / or side chain is referred to as a "polymerizable end group." As described above, it is preferable that a polymerizable end group be introduced into the charge-transporting polymer. In one embodiment, for example, the charge-transporting material may be configured such that the first polymer contains a first polymerizable end group and the second polymer contains a second polymerizable end group different from the first polymerizable end group.

[0105] From the viewpoints of transparency and the properties of organic electronic devices, the first polymerizable substituent is a group having a carbon-carbon unsaturated bond (e.g., a vinyl group, an allyl group, a butenyl group, an ethynyl group, an acryloyl group, an acryloyloxy group, an acryloylamino group, a methacryloyl group, a methacryloyloxy group, a methacryloylamino group, a vinyloxy group, a vinylamino group, etc.).

[0106] Specific examples of the structural unit (4) include, but are not limited to, the following structural unit (4a), which is a monovalent structural unit.

[0107] *-Ar-(CH2) n -CH=CH2(4a)

[0108] In the structural unit (4a), * represents a bonding site with other structures, Ar represents a substituted or unsubstituted arylene group or heteroarylene group, and n is an integer of 0 to 20. The heteroarylene group refers to an atomic group obtained by removing two hydrogen atoms from an aromatic heterocycle. Specific examples of aromatic hydrocarbons include benzene, naphthalene, anthracene, tetracene, fluorene, and phenanthrene. The arylene group is preferably a phenylene group or a naphthylene group, and more preferably a phenylene group. Specific examples of aromatic heterocycles include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, and benzothiophene. From the viewpoint of improving life characteristics, n is preferably 0 to 8, more preferably 0 to 6, even more preferably 0 to 3, and particularly preferably 0 or 1. From the viewpoint of improving solubility, n is preferably 4 to 20, more preferably 4 to 16, even more preferably 4 to 12, and particularly preferably 4 to 8.

[0109] The structural unit (4a) has excellent reactivity, which allows the curing reaction of the charge-transporting polymer to proceed efficiently. Furthermore, when the charge-transporting polymer contains a polymerizable substituent that contributes to the curing reaction, an ink composition having excellent storage stability, as described below, can be obtained. The structure (4a) preferably has a small value of n, since this allows for the production of an organic electronics device that exhibits better life characteristics. On the other hand, the structural unit (1a) preferably has a large value of n, since this allows for excellent solubility.

[0110] The structural unit (4a) preferably has a structure such as that shown in the following structural formula:

[0111] [ka]

[0112] The first polymer may contain only one type of the structural unit, or may contain two or more types.

[0113] [Structural unit content] As described above, the structural unit (4) is preferably introduced into the terminal portion of the charge-transporting polymer. In this case, the content of the structural unit (4) is preferably 1 to 50 mol % based on the structural unit constituting the polymer terminal. From the viewpoint of improving the solvent resistance of the organic layer, the content of the structural unit is preferably 2 mol % or more, more preferably 3 mol % or more, even more preferably 5 mol % or more, and particularly preferably 10 mol % or more. From the viewpoint of the charge transport property of the charge-transporting polymer, the content of the structural unit is preferably 50 mol % or less, more preferably 45 mol % or less, and even more preferably 40 mol % or less. To obtain high charge transport property, the content may be 35 mol % or less, or even 30 mol % or less.

[0114] From the viewpoint of efficiently curing the charge-transporting polymer, the proportion of the first polymerizable substituent contained in the structural unit (4) is preferably 0.1 mol % or more, more preferably 1 mol % or more, and even more preferably 3 mol % or more, based on the structural units constituting the polymer terminals. Furthermore, from the viewpoint of obtaining good charge-transporting properties, the proportion of the first polymerizable substituent is preferably 70 mol % or less, more preferably 60 mol % or less, and even more preferably 50 mol % or less, based on all structural units. Here, the "proportion of polymerizable substituent" refers to the proportion of structural units having a polymerizable substituent.

[0115] From the viewpoint of contributing to the change in solubility, it is preferable that the first polymerizable substituent is contained in a large amount in the charge transport polymer. On the other hand, from the viewpoint of not interfering with the charge transport property, it is preferable that the first polymerizable substituent is contained in a small amount in the charge transport polymer. The content of the polymerizable substituent can be appropriately set taking these into consideration.

[0116] For example, the number of polymerizable substituents per molecule of the charge-transporting polymer is preferably 2 or more, more preferably 3 or more, from the viewpoint of obtaining a sufficient change in solubility, and is preferably 1,000 or less, more preferably 500 or less, from the viewpoint of maintaining charge-transporting properties.

[0117] The number of polymerizable substituents per molecule of the charge transport polymer can be determined as an average value using the amount of polymerizable substituents (for example, the amount of monomers having polymerizable substituents) used to synthesize the charge transport polymer, the amount of monomers corresponding to each structural unit, the weight average molecular weight of the charge transport polymer, etc. 1 It can be calculated as an average value using the ratio of the integral value of the signal derived from the polymerizable substituent to the integral value of the entire spectrum in a H NMR (nuclear magnetic resonance) spectrum, the weight average molecular weight of the charge transport polymer, etc. When the amount of charge is known, it is preferable to use the value calculated using the amount of charge because it is simple.

[0118] [Second polymer] (Structural unit (5)) The second polymer is the charge-transporting polymer described above, which contains a structural unit (5) having a second polymerizable substituent different from the first polymerizable substituent. The structural unit (5) having the second polymerizable substituent contained in the second polymer may be any of a monovalent structural unit having one bonding site with another structure, a divalent structural unit having two bonding sites with another structure, or a trivalent or higher structural unit having three or more bonding sites with another structure. However, from the viewpoint of achieving both the curability and charge transportability of the charge-transporting polymer, it is preferable that the second polymerizable substituent be contained in a monovalent structural unit.

[0119] [Second Polymerizable Substituent] The second polymerizable substituent can be any of the polymerizable substituents exemplified as the first polymerizable substituent described above (provided that the first polymerizable substituent and the second polymerizable substituent are different from each other). For example, the second polymer can be a group having a small ring (e.g., a cyclic alkyl group such as a cyclopropyl group or a cyclobutyl group; a fused ring group such as a benzocyclobutenyl group; a cyclic ether group such as an epoxy group or an oxetanyl group; a diketene group; an episulfide group; a lactone group; a lactam group, etc.). From the viewpoint of curability by heating, a cyclopropyl group, a cyclobutyl group, a benzocyclobutenyl group, an epoxy group, or an oxetanyl group is more preferred, and a benzocyclobutenyl group, which is relatively stable and can be crosslinked by heating alone, is most preferred.

[0120] [Structural unit content] The content of the structural unit (5) is preferably 1 to 50 mol % based on the structural unit constituting the polymer terminal. From the viewpoint of improving the solvent resistance of the organic layer, the content of the structural unit is preferably 2 mol % or more, more preferably 3 mol % or more, even more preferably 5 mol % or more, and particularly preferably 10 mol % or more. From the viewpoint of the charge transport property of the charge transport polymer, the content of the structural unit is preferably 50 mol % or less, more preferably 45 mol % or less, and even more preferably 40 mol % or less. To obtain high charge transport property, the content may be 35 mol % or less, or may be 30 mol % or less.

[0121] The proportion of the second polymerizable substituent contained in the structural unit (5) is preferably 0.1 mol % or more, more preferably 1 mol % or more, and even more preferably 3 mol % or more, based on the structural units constituting the polymer terminals, from the viewpoint of efficiently curing the charge-transporting polymer. Also, from the viewpoint of obtaining good charge-transporting properties, the proportion of the polymerizable substituent is preferably 70 mol % or less, more preferably 60 mol % or less, and even more preferably 50 mol % or less, based on all structural units.

[0122] In this embodiment, the first polymer and the second polymer are described as examples. However, the present invention is not limited to these examples. The charge-transporting material may contain two or more charge-transporting polymers having different polymerizable substituents, such as the first polymer and the second polymer. The ratio of the two or more charge-transporting polymers contained in the charge-transporting material is not particularly limited. For example, the charge-transporting material may contain equal amounts of the first polymer and the second polymer. This configuration allows for an organic layer with superior solvent resistance compared to a charge-transporting material containing only one charge-transporting polymer with a polymerizable substituent, making it easy to incorporate a multilayer organic layer into an organic electronics device. Furthermore, compared to a charge-transporting material containing a single charge-transporting polymer having two polymerizable substituents, the charge-transporting material of this embodiment allows for the synthesis of a charge-transporting polymer without having to consider the compatibility and blending ratio of the two polymerizable substituents. This makes it easy to obtain an organic layer with excellent solvent resistance, making it easy to incorporate a multilayer organic layer into an organic electronics device.

[0123] [Optional ingredients] Additives such as polymerization initiators, antioxidants, anti-yellowing agents, ultraviolet absorbers, visible light absorbers, colorants, plasticizers, stabilizers, and fillers may be added to the organic electronics device within a range that does not adversely affect the device's properties. Furthermore, an ionic compound may be mixed with the charge transport material to improve the luminous efficiency and lifespan of the organic EL device. By mixing and using an ionic compound, the electrical conductivity, stability, and lifespan of the organic EL device can be improved.

[0124] (ionic compounds) Here, in this specification and the like, the term "ionic compound" refers to a compound consisting of a cation and an anion. From the viewpoint of electrical conductivity and stability, an anion containing an electron-withdrawing organic substituent is preferred, and examples thereof include halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; alkylsulfonyl groups substituted with alkyls such as cyano groups, thiocyano groups, nitro groups, and mesyl groups; arylsulfonyl groups substituted with aryls such as tosyl groups and mesityl groups; acyl groups having a carbon number of typically 1 to 12, preferably 6, such as formyl groups, acetyl groups, and benzoyl groups; alkoxycarbonyl groups having a carbon number of typically 2 to 10, preferably 7, such as methoxycarbonyl groups and ethoxycarbonyl groups; and alkoxycarbonyl groups having a carbon number of typically 2 to 10, preferably 7, such as phenoxycarbonyl groups and pyridyloxycarbonyl groups. Examples of such groups include an aryloxycarbonyl group having an aromatic hydrocarbon group or an aromatic heterocyclic group of typically 3 or more, preferably 4 or more and 25 or less, and preferably 15 or less; an acyloxy group having typically 2 to 20 carbon atoms such as acetoxy; a haloalkyl, haloalkenyl, haloalkynyl group having typically 1 to 10 carbon atoms, preferably 6 or less, linear, branched, or cyclic alkyl, alkenyl, or alkynyl group having a carbon atom substituted with a halogen atom such as a fluorine atom or a chlorine atom, and a haloaryl group having typically 6 to 20 carbon atoms such as a pentafluorophenyl group.

[0125] The cation in the ionic compound is not particularly limited, but is preferably a monovalent cation from the viewpoint of reactivity and ease of handling. More preferred cations of the ionic compound include iodonium, sulfonium, phosphonium, carbenium (trityl), anilinium, bismuthonium, ammonium, selenium, pyridinium, imidazolium, oxonium, quinolinium, pyrrolidinium, aminium, immonium, tropylium, morpholinium, piperidinium, quinolium, isoquinolium, thiazonium, and acridium.

[0126] The cation may be contained in a polymer.

[0127] In addition, the ionic compound is preferably an onium salt from the viewpoint of improving charge transportability. The onium salt refers to a compound consisting of a cation such as a sulfonium ion, an iodonium ion, a selenium ion, an ammonium ion, a phosphonium ion, an oxonium ion, or a bismuthonium ion and a counter anion. Examples of the anion include F - , Cl - , Br - , I - Halogen ions such as OH - ;ClO4 - ;FSO3 - , ClSO3 - , CH3SO3 - , C6H5SO3 - , CF3SO3 - Sulfonic acid ions such as HSO4 - , SO4 2- Sulfate ions such as HCO3 - , CO3 2- Carbonate ions such as H2PO4 - , HPO4 2- , PO4 3- Phosphate ions such as PF6 - , PF5OH - Fluorophosphate ions such as BF4 - , B(C6F5)4 - , B(C6H4CF3)4 - Boric acid ions such as AlCl4 - ;BiF6 - ;SbF6 - , SbF5OH - Fluoroantimonate ions such as AsF6 - , AsF5OH - and fluoroarsenate ions such as the above.

[0128] The ionic compounds may be used alone or in combination of two or more.

[0129] (Polymerization initiator) The ionic compound can be used as a polymerization initiator to promote the curing of the charge transport polymer. The trigger for initiating polymerization is not particularly limited as long as it exhibits the ability to polymerize a polymerizable substituent by application of heat, light, microwaves, radiation, electron beams, etc., but is preferably one that initiates polymerization by light irradiation and / or heating, and most preferably one that initiates polymerization by heating.

[0130] In this embodiment, the polymerization initiator is used in an amount of 0.1 to 50% by mass, more preferably 0.1 to 25% by mass, and even more preferably 0.1 to 20% by mass, based on the charge transport material. If the proportion of the polymerization initiator mixed is less than this, polymerization does not proceed efficiently and the solubility cannot be changed sufficiently. If the proportion is greater than this, a large amount of polymerization initiator and / or decomposition products remain, reducing the effectiveness of washing. Furthermore, a sensitizer may be included to improve photosensitivity and / or heat sensitivity.

[0131] <Ink composition> The ink composition of this embodiment is characterized by containing the above-described charge transport material and a solvent, and may also contain other additives such as a polymerization inhibitor, a stabilizer, a thickener, a gelling agent, a flame retardant, an antioxidant, a reduction inhibitor, an oxidizing agent, a reducing agent, a surface modifier, an emulsifier, an antifoaming agent, a dispersant, a surfactant, etc. Examples of the solvent include water and alcohols such as methanol, ethanol, and isopropyl alcohol; alkanes such as pentane, hexane, and octane; cyclic alkanes such as cyclohexane; aromatic solvents such as benzene, toluene, xylene, mesitylene, tetralin, and diphenylmethane; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethoxytoluene, 2,4-dimethylphenyl ether, 2,5-dimethylphenyl ether, 2,6-dimethylphenyl ether, 1,7-dimethylphenyl ether, 1,8-dimethylphenyl ether, 1,9 ... Examples of the solvent include aromatic ethers such as methylanisole and 2,4-dimethylanisole; aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate and n-butyl lactate; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate and n-butyl benzoate; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; and others such as dimethyl sulfoxide, tetrahydrofuran, acetone, chloroform and methylene chloride. However, aromatic solvents, aliphatic esters, aromatic esters, aliphatic ethers and aromatic ethers are preferably used.

[0132] In the ink composition of this embodiment, the content of the charge transporting polymer relative to the solvent is preferably 0.1 to 50% by mass from the viewpoint of applicability to various coating processes. From the viewpoint of reducing the amount of solvent remaining during film formation, the content of the charge transporting polymer is more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. Furthermore, from the viewpoint of uniformly dissolving the charge transporting material, the content is more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0133] <Organic layer> The organic layer of this embodiment is a layer formed using the charge transport material or ink composition. By using a charge transport material or ink composition containing a solvent, an organic layer can be successfully formed by a coating method. Examples of coating methods include known methods such as spin coating; casting; immersion; plate-based printing methods such as relief printing, intaglio printing, offset printing, lithographic printing, relief reverse offset printing, screen printing, and gravure printing; and plateless printing methods such as inkjet printing. When forming an organic layer by a coating method, the organic layer (coated layer) obtained after coating may be dried using a hot plate or oven to remove the solvent.

[0134] When the charge-transporting polymer contains a polymerizable substituent, the polymerization reaction can be accelerated by light irradiation, heat treatment, or the like, thereby changing the solubility of the organic layer. In the charge-transporting material, an ionic compound can function as a polymerization initiator. By stacking organic layers with different solubilities, it becomes possible to easily achieve a multilayer organic electronics device. Regarding the method for forming the organic layer, the description of International Publication No. 2010 / 140553 can be cited, for example.

[0135] For example, an organic layer can be formed by forming a thin film from an ink composition containing the above-mentioned charge transport polymer, polymerization initiator, and solvent, and then heating the thin film in vacuum, air, or an inert gas atmosphere such as nitrogen or argon. The heating temperature and time are not particularly limited as long as they allow the polymerization reaction to proceed sufficiently. However, since various substrates can be used, the temperature is preferably 300°C or less, more preferably 200°C or less, and even more preferably 150°C or less. From the viewpoint of increasing productivity, the heating time is preferably 8 hours or less, more preferably 2 hours or less, and even more preferably 1 hour or less.

[0136] The thickness of the organic layer after drying or curing is preferably 0.1 nm or more, more preferably 1 nm or more, and even more preferably 3 nm or more from the viewpoint of improving charge transport efficiency, and is preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less from the viewpoint of reducing electrical resistance.

[0137] The organic layer of this embodiment can be used in the organic electronics elements and organic EL elements described below, and can form organic electronics elements and organic EL elements that have a lower driving voltage and a longer light emission lifetime than conventional elements. <Organic electronics elements> The organic electronic device of this embodiment includes at least one of the organic layers. Examples of the organic electronic device include organic EL devices such as organic light-emitting diodes (OLEDs), organic photoelectric conversion devices, and organic transistors. The organic electronic device preferably has a structure in which an organic layer is disposed between at least a pair of electrodes. The organic electronic device of this embodiment is not particularly limited as long as it includes a light-emitting layer, an organic layer, an anode, a cathode, and a substrate. The organic layer can be used as a hole injection layer, an electron injection layer, a hole transport layer, or an electron transport layer.

[0138] <Organic EL element> The organic EL device of this embodiment includes at least one organic layer. The organic EL device of this embodiment is not particularly limited as long as it includes an emitting layer, an organic layer, an anode, a cathode, and a substrate. The organic layer can be used as a hole injection layer, an electron injection layer, a hole transport layer, or an electron transport layer. It is also preferable to use the organic layer of this embodiment as the hole injection layer or the hole transport layer.

[0139] Fig. 1 is a cross-sectional view showing one embodiment of an organic EL element. The organic EL element shown in Fig. 1 has a multilayer structure in which a substrate 8, an anode 2, a hole injection layer 3, a hole transport layer 6, an emitting layer 1, an electron transport layer 7, an electron injection layer 5, and a cathode 4 are laminated in this order. Each layer will be described in detail below.

[0140] (Emitting layer) The material used for the light-emitting layer may be a low-molecular-weight compound or a polymer, and dendrimers and the like can also be used. Examples of low-molecular-weight compounds that utilize fluorescence include perylene, coumarin, rubrene, quinacridone, dyes for dye lasers (e.g., rhodamine, DCM1, etc.), aluminum complexes (e.g., Tris(8-hydroxyquinolinato)aluminum(III) (Alq3)), stilbene, and derivatives thereof. Examples of polymers that utilize fluorescence include polyfluorene, polyphenylene, polyphenylenevinylene (PPV), polyvinylcarbazole (PVK), fluorene-benzothiadiazole copolymers, fluorene-triphenylamine copolymers, and derivatives and mixtures thereof.

[0141] Meanwhile, in recent years, in order to improve the efficiency of organic EL devices, the development of phosphorescent organic EL devices has also been actively pursued. Phosphorescent organic EL devices can utilize not only singlet state energy but also triplet state energy, and in principle, the internal quantum yield can be increased to 100%. In phosphorescent organic EL devices, phosphorescent light is extracted by doping a metal complex phosphorescent material containing a heavy metal such as platinum or iridium as a phosphorescent dopant into a host material (see 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)).

[0142] In the organic EL device of this embodiment, it is also preferable to use a phosphorescent material in 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 suitably used. Specifically, as the Ir complex, for example, FIr(pic) [iridium(III)bis[(4,6-difluorophenyl)-pyridinate-N,C], which emits blue light, can be used. 2]picolinate], Ir(ppy)3 [fatty tris(2-phenylpyridine)iridium] exhibiting green emission (see MA Baldo et al., Nature, Vol. 403, p. 750 (2000) above), or (btp)2Ir(acac){bis[2-(2'-benzo[4,5-α]thienyl)pyridinato-N,C] 3 ]iridium(acetylacetonate)}, Ir(piq)3 [tris(1-phenylisoquinoline)iridium] (see Adachi et al., Appl. Phys. Lett., 78 no. 11, 2001, 1622, supra).

[0143] Examples of Pt complexes include 2,3,7,8,12,13,17,18-octaethyl-21H,23H-phorphine platinum (PtOEP), which emits red light. The phosphorescent material may be a small molecule or dendritic species, such as an iridium-cored dendrimer, and derivatives thereof may also be suitably used.

[0144] When the light-emitting layer contains a phosphorescent material, it preferably contains a host material in addition to the phosphorescent material. The host material may be a low-molecular-weight compound or a high-molecular-weight compound, and a dendrimer or the like may also be used.

[0145] Examples of low molecular weight compounds that can be used include CBP (4,4'-Bis(Carbazol-9-yl)-biphenyl), mCP (1,3-bis(9-carbazolyl)benzene), and CDBP (4,4'-Bis(Carbazol-9-yl)-2,2'-dimethylbiphenyl). Examples of high molecular weight compounds that can be used include polyvinylcarbazole, polyphenylene, and polyfluorene, and derivatives of these compounds can also be used.

[0146] The light-emitting layer may be formed by a vapor deposition method or a coating method. Formation by a coating method is more preferable because it allows the organic EL device to be produced at low cost. To form the light-emitting layer by a coating method, a solution containing a phosphorescent material and, if necessary, a host material can be applied to a desired substrate by a known method, such as a printing method such as an inkjet method, a casting method, a dipping method, letterpress printing, intaglio printing, offset printing, lithographic printing, letterpress reverse offset printing, screen printing, or gravure printing, or a spin coating method.

[0147] (cathode) The cathode material is preferably a metal or a metal alloy such as Li, Ca, Mg, Al, In, Cs, Ba, Mg—Ag, LiF, or CsF.

[0148] (anode) The anode may be made of a metal (e.g., Au) or other material with metallic conductivity, such as an oxide (e.g., ITO) or a conductive polymer (e.g., a polythiophene-polystyrene sulfonic acid mixture (PEDOT:PSS)).

[0149] (hole transport layer, hole injection layer) It is preferable to use the organic layer described above as at least one of a hole transport layer and a hole injection layer. As described above, these layers can be easily formed by using an organic layer containing an organic electronic material. Furthermore, for example, when an organic EL device has the organic layer described above as a hole transport layer and further has a hole injection layer, a known material may be used for the hole injection layer. Furthermore, when an organic EL device has the organic layer described above as a hole injection layer and further has a hole transport layer, a known material may be used for the hole transport layer. Furthermore, an organic EL device may have the organic layer described above as a hole transport layer and a hole injection layer.

[0150] When a material containing a triphenylamine structure is used for the hole injection layer, it is preferable to use the above-mentioned organic layer for the hole transport layer from the viewpoint of the energy level for hole migration. In this case, the polymerization initiator may be contained in the organic layer that is the hole transport layer, or in an organic layer below the hole transport layer.

[0151] (electron transport layer, electron injection layer) Examples of materials for the electron transport layer and electron injection layer include phenanthroline derivatives (e.g., 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)), bipyridine derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic acid anhydrides such as naphthalene perylene, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives (2-(4-biphenylyl)-5-(4-tert-butylphenyl-1,3,4-oxadiazole) (PBD)), and aluminum complexes (e.g., Tris(8-hydroxyquinolinato)aluminum(III) (Alq3)). Thiadiazole derivatives, in which the oxygen atom of the oxadiazole ring is replaced with a sulfur atom, and quinoxaline derivatives having a quinoxaline ring, which is known as an electron-withdrawing group, can also be used.

[0152] (substrate) The substrate usable for the organic EL element of this embodiment is not particularly limited to the type of glass, plastic, etc., and is not particularly limited as long as it is transparent, but glass, quartz, a light-transmitting resin film, etc. is preferably used. When a resin film is used, flexibility can be imparted to the organic EL element, and it is particularly preferred because it functions as a flexible substrate.

[0153] Examples of resin films include films made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), etc.

[0154] When a resin film is used, the resin film may be coated with an inorganic material such as silicon oxide or silicon nitride in order to suppress the permeation of water vapor, oxygen, and the like.

[0155] (Emitting color) The color of light emitted from the organic EL element of this embodiment is not particularly limited, but a white light-emitting element is preferred because it can be used in various lighting fixtures such as home lighting, car lighting, clocks, and LCD backlights.

[0156] Currently, it is difficult to produce white light from a single material, so white light is obtained by using multiple light-emitting materials to simultaneously emit multiple colors and mixing them. Combinations of multiple colors include, but are not limited to, those containing three maximum emission wavelengths (blue, green, and red), and those containing two maximum emission wavelengths that utilize complementary color relationships, such as blue and yellow, or yellow-green and orange. Furthermore, the emission color can be controlled by adjusting the type and amount of phosphorescent material.

[0157] <Display elements, lighting devices, display devices> The display element of this embodiment is characterized by including the organic EL element. For example, by using organic EL elements as elements corresponding to each pixel of red, green, and blue (RGB), a color display element can be obtained. Image formation methods include a simple matrix type that directly drives individual organic EL elements arranged on a panel with electrodes arranged in a matrix, and an active matrix type that arranges and drives a thin film transistor for each element. The former has a simple structure but is limited in the number of vertical pixels, so it is used for displays such as characters. The latter has a low driving voltage and requires little current, and can obtain a bright and high-definition image, so it is used for high-quality displays.

[0158] In addition, the lighting device of this embodiment is characterized by including the organic EL element. Further, the display device of this embodiment is characterized by including the lighting device and a liquid crystal element as a display means. A display device using the above lighting device as a backlight (white light source) and a liquid crystal element as a display means, that is, a liquid crystal display device, may be used. This configuration is a configuration in which only the backlight in a known liquid crystal display device is replaced with the above lighting device, and the liquid crystal element portion can use known techniques.

Example

[0159] Hereinafter, the present embodiment will be described more specifically with reference to examples, but the present embodiment is not limited to the following examples.

[0160] Hereinafter, a synthesis example of the charge transport material used in this example will be shown.

[0161] <Preparation of Pd Catalyst> In a glove box under a nitrogen atmosphere, a fluororesin-coated ceramic stir bar was placed in a glass sample vial at room temperature. 73.2 mg (80 μmol) of tris(dibenzylideneacetone)dipalladium was weighed out, 15 mL of toluene was added, and the mixture was stirred for 30 minutes. Similarly, a fluororesin-coated ceramic stir bar was placed in a glass sample vial. 129.6 mg (640 μmol) of tris(t-butyl)phosphine was weighed out, 5 mL of toluene was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at 80 °C for 2 hours. The resulting solution was filtered through a 0.2 μm pore membrane filter to remove insoluble matter, and the resulting solution was used as the catalyst. All solvents were degassed by bubbling nitrogen for at least 30 minutes before use.

[0162] <Synthesis of charge transport materials> (Synthesis of charge transporting polymer 1) A 100 mL three-necked round-bottom glass flask was charged with 2.34 g (4.6 mmol) of Monomer 1 (see below), 0.87 g (1.8 mmol) of Monomer 2 (see below), 0.91 g (3.1 mmol) of Monomer 3 (see below), 0.15 g (0.6 mmol) of Monomer 4 (see below), and 17.7 mL of toluene. 3.9 mL of a 1% by mass trioctylmethylammonium chloride toluene solution and 7.2 mL of a 3 M potassium hydroxide aqueous solution were then added. All solvents were degassed by nitrogen bubbling for at least 30 minutes before use. A reflux condenser and nitrogen gas flow tube were attached to the flask containing the reaction solution, and the flask was immersed in an oil bath heated to 60 °C and stirred for 30 minutes to dissolve the monomer. Next, 1.0 mL of the Pd catalyst solution prepared above was added, and the oil bath temperature was raised to 120 °C to carry out the reaction. The reaction solution was heated to reflux for 2 hours. All reactions were carried out under a nitrogen stream.

[0163] [ka]

[0164] After the reaction was complete, the organic layer was removed and poured into a 9:1 methanol-water mixture. The resulting precipitate was filtered and washed with methanol. The resulting precipitate was washed with ethyl acetate, and the eluted solid was vacuum dried. The dried solid was dissolved in toluene, and a metal adsorbent (Strem Chemicals' "Triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer," 200 mg per 100 mg of precipitate) was added and stirred at 40°C for 2 hours. After stirring, the solution was filtered through a 0.2 μm pore membrane filter to remove the metal adsorbent and solid impurities, and then poured into methanol. The precipitate was suction filtered, washed with methanol, and then vacuum dried to obtain charge-transporting polymer 1.

[0165] (Synthesis of charge transporting polymer 2) Charge transporting polymer 1 was synthesized in the same manner as in the synthesis of the above charge transporting polymer 1, except that the reaction was carried out using the following monomer 5 instead of monomer 4.

[0166] [ka]

[0167] (Synthesis of charge transporting polymer 3) The synthesis was carried out in the same manner as in the synthesis of the above charge transporting polymer 1, except that the reaction was carried out using the following monomer 6 instead of monomer 4.

[0168] [ka]

[0169] (Synthesis of charge transporting polymer 4) Charge transporting polymer 1 was synthesized in the same manner as in the synthesis of the above charge transporting polymer 1, except that the reaction was carried out using the following monomer 7 instead of monomer 4.

[0170] [ka]

[0171] (Evaluation of Solvent Resistance) An organic layer was formed using a charge-transporting polymer, and solvent resistance was evaluated by measuring the residual film ratio as follows. Specifically, an organic layer was formed using the steps described below, and the quartz plate with the formed organic layer was immersed in 10 mL of toluene under atmospheric pressure and at room temperature and allowed to stand for 10 minutes. The residual film ratio (%) of the organic layer was calculated using the following formula from the ratio of the absorbance (Abs) at the absorption maximum (λmax) in the visible ultraviolet spectroscopy (UV-vis) spectrum before and after immersion of the organic layer in toluene. The higher the residual film ratio, the better the solvent resistance.

[0172] Residual film rate (%) = (absorbance of organic layer after immersion in toluene / absorbance of organic layer before immersion in toluene) × 100

[0173] Example 1 The charge-transporting polymer 1 (5.0 mg) and the charge-transporting polymer 3 (5.0 mg) were weighed between glass samples and dissolved in 0.9 mL of toluene to prepare a charge-transporting polymer solution. The charge-transporting polymer solution was spin-coated onto a quartz plate at 3,000 rpm in air. The spin-coated quartz plate was then placed in a nitrogen-atmosphere glove box and heated on a hot plate at 230°C for 30 minutes to undergo a curing reaction, forming an organic layer. The remaining film ratio (%) of the organic layer was then calculated.

[0174] Example 2 The same procedure as in Example 1 was carried out except that Charge Transporting Polymer 4 was used instead of Charge Transporting Polymer 3, and the remaining film ratio was measured.

[0175] Example 3 The same procedure as in Example 1 was carried out except that Charge Transporting Polymer 2 was used instead of Charge Transporting Polymer 1, and the remaining film ratio was measured.

[0176] Example 4 The same procedure as in Example 3 was carried out except that Charge Transporting Polymer 4 was used instead of Charge Transporting Polymer 3, and the remaining film ratio was measured.

[0177] (Comparative Example 1) The same procedure as in Example 1 was carried out except that charge transporting polymer 1 was used instead of charge transporting polymer 3, and the remaining film ratio was measured (total amount of charge transporting polymer 1: 10.0 mg).

[0178] (Comparative Example 2) The same procedure as in Example 3 was carried out except that Charge Transporting Polymer 2 was used instead of Charge Transporting Polymer 3, and the remaining film rate was measured (total amount of Charge Transporting Polymer 2: 10.0 mg).

[0179] The results of Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 1 below.

[0180] [Table 1]

[0181] It can be seen from Examples 1 to 4 that the use of two types of charge transporting polymers improves the film remaining rate compared to Comparative Examples 1 and 2, in which only one type of charge transporting polymer is used.

[0182] As described above, when the charge transporting material contains two types of charge transporting polymers, it becomes possible to laminate organic layers in a good condition. [Explanation of symbols]

[0183] 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 PCB

Claims

1. a first polymer having a first polymerizable substituent; a second polymer having a second polymerizable substituent different from the first polymerizable substituent.

2. 2. The charge transport material of claim 1, wherein the first polymerizable substituent comprises the following structure: *-Ar-(CH ２ ) ｎ -CH=CH ２ In the above structure, * represents a bonding site to another structure, Ar represents a substituted or unsubstituted arylene group or heteroarylene group, and n is an integer of 0 to 20.

3. 3. The charge transport material according to claim 2, wherein Ar is a substituted or unsubstituted phenylene group.

4. 4. The charge transport material according to claim 1, wherein the second polymerizable substituent comprises at least one selected from the group consisting of a cyclopropyl group, a cyclobutyl group, a benzocyclobutenyl group, an epoxy group, and an oxetanyl group.

5. 5. The charge transport material according to claim 1, wherein the second polymerizable substituent comprises a benzocyclobutenyl group.

6. An ink composition comprising the charge transporting material according to any one of claims 1 to 5 and a solvent.

7. An organic layer formed using the charge transporting material according to any one of claims 1 to 5 or the ink composition according to claim 6.

8. An organic electronic device comprising at least one organic layer according to claim 7 .

9. An organic electroluminescence device comprising at least one organic layer according to claim 7 .

10. The organic electroluminescent device according to claim 9 , further comprising a flexible substrate.

11. The organic electroluminescence device according to claim 9 , further comprising a resin film substrate.

12. A display device comprising the organic electroluminescence device according to any one of claims 9 to 11.

13. A lighting device comprising the organic electroluminescence element according to any one of claims 9 to 11.

14. A display device comprising the organic electroluminescence element according to any one of claims 9 to 11.

15. A display device comprising the display device according to claim 14 and a liquid crystal element as a display means.

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