Charge transport materials and organic electronic devices

Abstract

To provide a charge transport material with excellent curability. [Solution] A charge transport material comprising an ionic compound containing a cation selected from the group consisting of a pyridine ring, a quinoline ring, an isoquinoline ring, and an acridine ring, and a charge transport polymer having a polymerizable functional group.

Description

Technical Field

[0001] The present disclosure relates to a charge transporting material, an ink composition, an organic electronic device, an organic electroluminescent device (organic EL device), and a photoelectric conversion device.

Background Art

[0002] An organic electronic device is a device that performs electrical operations using organic substances, and is expected to exhibit features such as energy saving, low cost, and flexibility. Examples of organic electronic devices include organic EL devices, organic photoelectric conversion devices, organic transistors, and the like.

[0003] Further improvement in various device characteristics of these organic electronic devices is desired. For example, as a means for enhancing the performance of an organic EL device, attempts have been made to form a multilayer organic layer and separate the functions of each layer. When forming a multilayer by a wet process, solvent resistance of the lower layer against the solvent of the coating solution used for forming the upper layer is required.

[0004] In order to form a multilayer organic layer, for example, a method using a compound having at least one polymerizable group has been studied (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present disclosure provides a charge transporting material having excellent curability and an ink composition containing the charge transporting material. Further, the present disclosure provides an organic electronic device, an organic EL device, and a photoelectric conversion device including an organic layer having excellent solvent resistance.

Means for Solving the Problem

[0007] The present invention includes the following embodiments. The present invention is not limited to the following embodiments. (1) A charge transport material containing an ionic compound containing a cation having at least one selected from the group consisting of a pyridine ring, a quinoline ring, an isoquinoline ring, and an acridine ring, and a charge transport polymer having a polymerizable functional group. (2) The charge transport material according to (1), wherein the cation includes at least one selected from the group consisting of a cation represented by the following formula (Py1), a cation represented by the following formula (Py2), a cation represented by the following formula (Py3), and a cation represented by the following formula (Py4).

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0008] According to this disclosure, a charge transport material having excellent curability and an ink composition containing the charge transport material can be obtained. Furthermore, according to this disclosure, an organic electronic device, an organic EL device, and a photoelectric conversion device containing an organic layer with excellent solvent resistance can be obtained. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will now be described. The present invention is not limited to the following embodiments. Furthermore, the following embodiments can be implemented individually or in combination. Combinations of multiple embodiments are also included in the present invention.

[0010] In numerical ranges described stepwise within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, the upper or lower limits of numerical ranges described within this disclosure may be replaced with the values ​​shown in the examples. A numerical value may be selected from the upper and lower limits described stepwise within this disclosure to form a stepped numerical range. Also, the upper and lower limits described within this disclosure may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple types of the substance corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple types of substances present in the composition, unless otherwise specified. In this disclosure, each structure in the polymer may contain multiple types of that structure. When multiple types of structures exist in the polymer, the content or amount of each structure means the total content or amount of those multiple types of structures present in the polymer, unless otherwise specified. In this disclosure, “layers” include continuous and discontinuous layers. The thickness of a “layer” may be uniform or non-uniform. The outer edges of a “layer” in the planar direction and the outer edges in the thickness direction may be defined or indefinite, respectively. The same applies to “films.”

[0011] <Charge transport material> An embodiment of the present invention, a charge-transporting material, contains an ionic compound and a charge-transporting polymer having a polymerizable functional group. The ionic compound is a compound containing a cation, which includes at least one selected from the group consisting of a pyridine ring, a quinoline ring, an isoquinoline ring, and an acridine ring. The ionic compound usually contains a cation and anion such that their charges are balanced. In the charge-transporting material, the ionic compound may function as a polymerization initiator that initiates the polymerization reaction of the charge-transporting polymer having a polymerizable functional group. The charge-transporting material may contain only one ionic compound or two or more ionic compounds.

[0012] [Ionic compounds] The ionic compound contains a cation comprising at least one selected from the group consisting of a pyridine ring, a quinoline ring, an isoquinoline ring, and an acridine ring. The charge transport material has excellent curability by containing an ionic compound containing a cation comprising at least one selected from the group consisting of a pyridine ring, a quinoline ring, an isoquinoline ring, and an acridine ring.

[0013] (cation) The ionic compound may contain, for example, at least one selected from the group consisting of a cation having a pyridine ring, a cation having a quinoline ring, a cation having an isoquinoline ring, and a cation having an acridine ring; it may contain at least one selected from the group consisting of pyridinium, quinolinium, isoquinolinium, and acridinium; and it may contain at least one selected from the group consisting of a cation represented by the following formula (Py1), a cation represented by the following formula (Py2), a cation represented by the following formula (Py3), and a cation represented by the following formula (Py4). When the ionic compound contains a cation represented by any of the following formulas, the charge transport material tends to exhibit better curability.

[0014] In embodiments of the present invention, the smaller the ionic interaction energy of the ionic compound, the weaker the electrical bond between the cation and anion during salt formation, and the less energy is required for charge separation. The ionic interaction energy tends to be lower if the cation has a conjugated structure containing a nitrogen atom, or has appropriate steric hindrance. Furthermore, the smaller the proton dissociation energy of the ionic compound, the easier it is for the proton to separate from the cation. The proton dissociation energy tends to be lower if the cation has a resonance structure. From these tendencies, it is presumed that if the ionic compound contains a cation comprising at least one selected from the group consisting of a pyridine ring, a quinoline ring, an isoquinoline ring, and an acridine ring, the formation of proton adducts of charge-transporting polymers will proceed more easily, and the polymerization reaction can be carried out efficiently. Note that the considerations and presumptions described in this disclosure do not limit the present invention.

[0015] (Cation containing a pyridine ring) A cation having a pyridine ring may have one or more pyridine rings, preferably a cation having one pyridine ring. The pyridine ring may be substituted or unsubstituted. If the pyridine ring is substituted, the substituents may be, for example, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, arylalkyl groups, heteroarylalkyl groups, alkylaryl groups, alkylheteroaryl groups, halogen groups, nitro groups, cyano groups, amino groups, imino groups, bis(alkylcarbonyl)amino groups, bis(alkylcarbonyl)amino groups, bis(alkylcarbonyl)amino groups, alkylcarbonylamino groups, arylcarbonylamino groups, heteroarylcarbonylamino groups, alkyloxycarbonylamino groups, aryloxycarbonylamino groups, heteroaryloxycarbonylamino groups, silyl groups, sulfo groups, or phosphoric acid. The substituents include at least one selected from the group consisting of a halogen group, a phosphono group, a phosphoryl group, a hydroxyl group, a thio group, a formyl group, a carboxyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylthio group, an arylthio group, a heteroarylthio group, an alkylcarbonyl group, an arylcarbonyl group, a heteroarylcarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, a heteroarylcarbonyloxy group, an alkyloxycarbonyloxy group, an aryloxycarbonyloxy group, a heteroaryloxycarbonyl group, an alkyloxycarbonyloxy group, an aryloxycarbonyloxy group, and a heteroaryloxycarbonyloxy group. These substituents may be substituted or unsubstituted substituents, and the substituents that a substituted substituent may have may include, for example, at least one selected from the group. Examples of halogen groups include a fluoro group, a chloro group, a bromo group, an iodo group, etc. The examples of substituents also apply to cations other than those having a pyridine ring, as illustrated below.

[0016] Cations having a pyridine ring include, for example, the cation represented by the following formula (Py1).

[0017] [ka]

[0018] In the formula, R 2 ~R 6 Each of these independently represents a hydrogen atom or a substituent. In some embodiments, R 2 ~R 6 This includes at least one selected from the group consisting of halogens, alkyl groups, haloalkyl groups, aryl groups, heteroaryl groups, cyano groups; groups containing N to which N is bonded to a pyridine ring; groups containing O to which O is bonded to a pyridine ring; groups containing P to which P is bonded to a pyridine ring; and groups containing S to which S is bonded to a pyridine ring. Specifically, it can be selected from the examples of substituents listed above. R 2 ~R 6 The example also applies to cations represented by formulas other than the formula (Py1) shown below.

[0019] In equation (Py1), for example, R 2 ~R 6 It is all hydrogen atoms. Or, for example, R 2 ~R 6 Each of them is independently either a hydrogen atom or a substituent; one is a substituent and the rest are hydrogen atoms; or one is an alkyl group (e.g., C1-C6), an alkenyl group (e.g., C1-C6), a substituted or unsubstituted amino group (substituting, for example, an alkyl group with C1-C6), or a cyano group, and the rest are hydrogen atoms. Or, for example, R 2 ~R 6 Each of them is independently either a hydrogen atom or a substituent; any two are substituents and the rest are hydrogen atoms; or any two are alkyl groups (e.g., 1 to 6 carbon atoms) and the rest are hydrogen atoms.

[0020] (Cation containing a quinoline ring) A cation having a quinoline ring may be a cation having one or more quinoline rings, preferably a cation having one quinoline ring. The quinoline ring may be substituted or unsubstituted. A cation having a quinoline ring includes, for example, a cation represented by the following formula (Py2).

[0021] [ka]

[0022] In the formula, R 2 ~R 8 Each of these independently represents a hydrogen atom or a substituent. In equation (Py2), for example, R 2 ~R 8 It is all hydrogen atoms. Or, for example, R 2 ~R 8 Each of them is independently either a hydrogen atom or a substituent; or one of them is a substituent and the rest are hydrogen atoms.

[0023] (Cation containing an isoquinoline ring) A cation having an isoquinoline ring may be a cation having one or more isoquinoline rings, preferably a cation having one isoquinoline ring. The isoquinoline ring may be substituted or unsubstituted. A cation having an isoquinoline ring includes, for example, a cation represented by the following formula (Py3).

[0024] [ka]

[0025] In the formula, R 1 and R 3 ~R 8 Each of these independently represents a hydrogen atom or a substituent. In equation (Py3), for example, R 1 and R 3 ~R 8 It is all hydrogen atoms. Or, for example, R 1and R 3 ~R 6 Each of them is independently either a hydrogen atom or a substituent; or one of them is a substituent and the rest are hydrogen atoms.

[0026] (Cation containing an acridine ring) A cation having an acridine ring may be a cation having one or more acridine rings, preferably a cation having one acridine ring. The acridine ring may be substituted or unsubstituted. A cation having an acridine ring includes, for example, a cation represented by the following formula (Py4).

[0027] [ka]

[0028] In the formula, R 1 ~R 9 Each of these independently represents a hydrogen atom or a substituent. In equation (Py4), for example, R 1 ~R 9 It is all hydrogen atoms. Or, for example, R 1 ~R 9 Each of them is independently either a hydrogen atom or a substituent; or one of them is a substituent and the rest are hydrogen atoms.

[0029] (Anion) Examples of anions contained in ionic compounds include anions whose negative charge is mainly located on oxygen, nitrogen, carbon, boron, gallium, phosphorus, or antimony atoms. Ionic compounds may contain, for example, boron-containing anions; substituted or unsubstituted tetrakis(aryl)boron anions; or diphenylmethylammonium tetrakis(pentafluorophenyl)borate.

[0030] Anions include, for example, anions represented by any of the following formulas (A1) to (A4).

[0031] [ka]

[0032] In the formula, R 11 ~R 20 These are each an independently electron-withdrawing monovalent group (R 12 and R 13 , R 14 ~R 16 At least two groups selected from, and R 17 ~R 20 At least two of the selected groups may be bonded to each other.

[0033] Examples of electron-withdrawing monovalent groups include halogen atoms such as fluorine, chlorine, and bromine; alkylsulfonyl groups such as cyano, thiocyano, nitro, and mesyl groups (e.g., 1 to 12 carbon atoms, preferably 1 to 6); arylsulfonyl groups such as tosyl groups (e.g., 6 to 18 carbon atoms, preferably 6 to 12); alkyloxysulfonyl groups such as methoxysulfonyl groups (e.g., 1 to 12 carbon atoms, preferably 1 to 6); aryloxysulfonyl groups such as phenoxysulfonyl groups (e.g., 6 to 18 carbon atoms, preferably 6 to 12); acyl groups such as formyl, acetyl, and benzoyl groups (e.g., 1 to 12 carbon atoms, preferably 1 to 6); acyloxy groups such as formyloxy and acetoxy groups (e.g., 1 to 20 carbon atoms, preferably 1 to 6); alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups (e.g., Examples include groups with 2 to 10 carbon atoms, preferably 2 to 7; "aryloxycarbonyl groups or heteroaryloxycarbonyl groups" such as phenoxycarbonyl groups and pyridyloxycarbonyl groups (e.g., 4 to 25 carbon atoms, preferably 5 to 15 carbon atoms); "haloalkyl groups, haloalkenyl groups or haloalkynyl groups" in which a halogen atom is substituted on a linear, branched, or cyclic "alkyl group, alkenyl group, or alkynyl group" such as trifluoromethyl group or pentafluoroethyl group (e.g., 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms); haloaryl groups in which a halogen atom is substituted on an aryl group such as pentafluorophenyl group (e.g., 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms); and haloarylalkyl groups in which a halogen atom is substituted on an arylalkyl group such as pentafluorophenylmethyl group (e.g., 7 to 19 carbon atoms, preferably 7 to 13 carbon atoms). 11 ~R 20 It is preferable that it be an organic group.

[0034] From the viewpoint of charge transport, the anion preferably contains an anion represented by the following formula (A4-1), and more preferably contains a tetrakis(aryl)boron anion. The aryl groups in the tetrakis(aryl)boron anion may be independently substituted or unsubstituted. Examples of substituents are the same as the substituents that the pyridine ring may have as described above.

[0035] [ka]

[0036] [Charge-transporting polymer] Charge-transporting polymers have polymerizable functional groups. The presence of polymerizable functional groups allows for curing. By curing a coating film containing a charge-transporting polymer to form an organic layer, the organic layer can be imparted with the solvent resistance necessary for laminating an upper layer by a wet process. In embodiments of the present invention, the uncured layer containing the charge-transporting polymer and the ionic compound, formed using an ink composition containing a charge-transporting material, may be referred to as a coating film. In this disclosure, "polymer" also includes so-called "oligomers" with a small number of structural units. A charge-transporting material containing a charge-transporting polymer having polymerizable functional groups and the aforementioned ionic compound allows for the formation of an organic layer with good solvent resistance. The charge-transporting material may contain only one type of charge-transporting polymer, or it may contain two or more types.

[0037] Examples of polymerizable functional groups include substituted or unsubstituted carbon-carbon multiple bonded groups (e.g., vinyl group (ethenyl group), styryl group, allyl group, butenyl group, ethynyl group, acryloyl group, acryloyloxy group, acryloylamino group, methacryloyl group, methacryloyloxy group, methacryloylamino group, vinyloxy group, vinylamino group), substituted or unsubstituted cyclic alkyl groups (e.g., cyclopropyl group, benzocyclobutenyl group, cyclobutyl group), and substituted or unsubstituted cyclic ether structures (e.g., epoxy group (oxyranyl group), oxetane group (oxetanyl group)). The substituents when these groups are substituted are not particularly limited, but examples include linear, branched, or cyclic alkyl groups. The number of carbon atoms in the alkyl group is preferably 1 to 22, more preferably 1 to 10, and even more preferably 1 to 4. In some embodiments, the polymerizable functional group has at least one group selected from the group consisting of oxyranyl group, oxetanyl group, ethenyl group, propargyl group, ethenyloxy group, propargyloxy group, ethenylphenyl group, and propargylphenyl group. The charge transport polymer may have groups having a substituted or unsubstituted cyclic ether structure, preferably substituted or unsubstituted oxetane groups (oxetanyl groups).

[0038] In charge-transporting polymers, it is preferable that polymerizable functional groups are introduced at least at the terminal portion of the charge-transporting polymer (i.e., structural unit T, described later). Polymerizable functional groups may also be introduced at non-terminal portions (i.e., structural units L or B, described later), or at both terminal and non-terminal portions. From the viewpoint of achieving both curability and charge transportability, it is preferable that they are introduced only at the terminal portion. If the charge-transporting polymer has a branched structure, polymerizable functional groups may be introduced at the main chain, at the side chains, or at both the main chain and side chains.

[0039] The number of polymerizable functional groups per molecule of charge-transporting polymer may be, for example, 2 or more, 3 or more, 5 or more, 10 or more, or 20 or more, from the viewpoint of obtaining a sufficient change in solubility. The number of polymerizable functional groups may be 1,000 or less, 800 or less, 700 or less, 600 or less, or 500 or less, from the viewpoint of maintaining charge transport properties.

[0040] The charge-transport polymer may be linear or branched, having a branched structure. For example, the charge-transport polymer may contain at least divalent structural units L and monovalent structural units T, and may further contain trivalent or higher-valent structural units B in the branched portion. The charge-transport polymer may contain at least trivalent or higher-valent structural units B and monovalent structural units T in the branched portion, and may further contain divalent structural units. The molecular chain has a chain-like structure containing at least one selected from the group consisting of divalent and trivalent structural units. If the charge-transport polymer is a branched polymer, it exhibits excellent heat resistance, and furthermore, many substituents or functional groups can be introduced at the ends. The charge-transport polymer may contain only one type of each structural unit, or multiple types of each. In the charge-transport polymer, each structural unit is bonded to one to three or more bonding sites.

[0041] In some embodiments, the charge-transporting polymer includes a branched structure having at least one structural unit B and three or more structural units L bonded to the one structural unit B. For example, the charge-transporting polymer includes a multiple branched structure having one structural unit B and three or more structural units L bonded to the one structural unit B, and further having at least one other structural unit B bonded to the three or more structural units L, and two or more other structural units L bonded to the other structural unit B for each of the three or more structural units L.

[0042] Examples of multiple branched structures contained in charge-transporting polymers include the following. In the structure, "L" represents a divalent structural unit, "B" represents a trivalent or higher structural unit, and "T" represents a monovalent structural unit. In the following structure, multiple Ls may be the same structural unit or different structural units. Multiple Bs may be the same structural unit or different structural units. Multiple Ts may be the same structural unit or different structural units. Note that charge-transporting polymers are not limited to polymers having the following structure.

[0043] [ka]

[0044] The charge-transporting polymer preferably contains a structural unit comprising at least one structure selected from the group consisting of aromatic amine structures, carbazole structures, thiophene structures, benzene structures, pyrrole structures, furan structures, and fluorene structures. Including any of these structures improves charge transport, particularly hole transport. In a preferred embodiment, the charge-transporting polymer contains a structural unit comprising an aromatic amine structure.

[0045] The charge-transport polymer contains, for example, structural unit L, structural unit B, or both structural unit L and structural unit B, a structural unit comprising at least one structure selected from the group consisting of aromatic amine structures, carbazole structures, thiophene structures, benzene structures, pyrrole structures, furan structures, and fluorene structures.

[0046] Structural unit L is a divalent structural unit having charge transport properties. Structural unit L is not particularly limited as long as it contains an atomic group that has the ability to transport charge. For example, structural unit L is selected from substituted or unsubstituted aromatic amine structures, carbazole structures, thiophene structures, bithiophene 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, N-arylphenoxazine structures, and structures containing one or more of these. The aromatic amine structure is preferably a triarylamine structure, and more preferably a triphenylamine structure.

[0047] In some embodiments, the structural unit L preferably includes one or more structures selected from the group consisting of substituted or unsubstituted aromatic amine structures, carbazole structures, thiophene structures, benzene structures, pyrrole structures, furan structures, and fluorene structures, from the viewpoint of obtaining excellent hole transportability; more preferably includes one or more structures selected from the group consisting of substituted or unsubstituted aromatic amine structures, carbazole structures, thiophene structures, furan structures, and fluorene structures; even more preferably includes one or more structures selected from the group consisting of substituted or unsubstituted aromatic amine structures and carbazole structures; and particularly preferably includes a substituted or unsubstituted aromatic amine structure.

[0048] Structural unit L includes, for example, a structural unit represented by the following formula (1) (hereinafter referred to as "structural unit (1)").

[0049] [ka]

[0050] In the formula, Ar independently represents a substituted or unsubstituted aromatic hydrocarbon group.

[0051] In the aromatic hydrocarbon group, the aromatic hydrocarbon is selected from the group consisting of, for example, benzene, naphthalene, anthracene, tetracene, fluorene, phenanthrene, 9,10-dihydrophenanthrene, triphenylene, pyrene, chrysene, perylene, triphenylene, pentacene, and benzopyrene. The aromatic hydrocarbon may be benzene, naphthalene, fluorene, anthracene, or phenanthrene, may be benzene or naphthalene, or may be benzene.

[0052] The Ar groups are preferably, independently, substituted or unsubstituted benzene groups, substituted or unsubstituted naphthalene groups, or substituted or unsubstituted anthracene groups, and more preferably substituted or unsubstituted benzene groups or substituted or unsubstituted naphthalene groups.

[0053] The aromatic hydrocarbon group may have substituents. Examples of substituents include -R 1 , -OR 2 , -SR 3 , -OCOR 4 ,-COOR 5 , -SiR 6 R 7 R 8 Examples include substituents selected from the group consisting of halogen groups and groups containing polymerizable functional groups (hereinafter sometimes referred to as "substituent Ra").

[0054] R 1 For example, it is selected from the group consisting of alkyl groups, aryl groups, and heteroaryl groups. 2 ~R 8 For example, each of these is independently selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a heteroaryl group.

[0055] In structural unit (1), at least one Ar may be a substituent aromatic hydrocarbon group, and preferably, from the viewpoint of solubility of the charge transport polymer, it may be an aromatic hydrocarbon group having an alkyl group (e.g., 1 to 6 carbon atoms).

[0056] Structural unit (1) includes, for example, a structural unit represented by the following formula (1a).

[0057] [ka]

[0058] In the formula, R represents either a hydrogen atom or a substituent, independently. An example of a substituent is the substituent Ra.

[0059] For example, at least one R may be an alkyl group (e.g., having 1 to 6 carbon atoms). The number of alkyl R groups may be, for example, 1 to 8, 1 to 6, 1 to 4, or 1 to 3. The non-alkyl R groups may be hydrogen atoms.

[0060] Structural unit B is a trivalent or higher structural unit contained in the branching portion when the charge-transporting polymer has a branched structure. From the viewpoint of improving the durability of organic electronic devices, structural unit B is, for example, hexavalent or less, and preferably trivalent or tetravalent. Structural unit B may be a unit that has charge-transporting properties. For example, from the viewpoint of improving the durability of organic electronic devices, structural unit B is selected from substituted or unsubstituted aromatic amine structures, carbazole structures, condensed polycyclic aromatic hydrocarbon structures, and structures containing one or more of these. For example, structural unit B is selected from substituted or unsubstituted aromatic amine structures, carbazole structures, condensed polycyclic aromatic hydrocarbon structures, and structures containing one or more of these. An example of a substituent is substituent Ra.

[0061] Structural unit B includes, for example, a structural unit represented by the following formula (2) (hereinafter referred to as "structural unit (2)").

[0062] [ka]

[0063] In the formula, Ar independently represents a substituted or unsubstituted aromatic hydrocarbon group.

[0064] For substituted or unsubstituted aromatic hydrocarbon groups, the description of substituted or unsubstituted aromatic hydrocarbon groups in structural unit (1) above can be applied. Ar is preferably an unsubstituted aromatic hydrocarbon group.

[0065] In structural unit (2), Ar is preferably independently a substituted or unsubstituted benzene group, a substituted or unsubstituted naphthalene group, or a substituted or unsubstituted anthracene group, more preferably a substituted or unsubstituted benzene group or a substituted or unsubstituted naphthalene group, and even more preferably a substituted or unsubstituted benzene group.

[0066] Structural unit (2) includes, for example, a structural unit represented by the following formula (2a).

[0067] [ka]

[0068] In the formula, each R independently represents either a hydrogen atom or a substituent. An example of a substituent is the substituent Ra. For example, all of R may be hydrogen atoms.

[0069] Structural unit T is a monovalent structural unit that constitutes the terminal portion of the charge-transporting polymer. Structural unit T is selected from, for example, substituted or unsubstituted aromatic hydrocarbon structures, aromatic heterocyclic structures, and structures containing one or more of these. From the viewpoint of imparting durability without reducing charge transportability, structural unit T is preferably a substituted or unsubstituted aromatic hydrocarbon structure, and more preferably a substituted or unsubstituted benzene structure. Examples of substituents include substituent Ra and polymerizable functional groups. When structural unit T contains polymerizable functional groups, good curability of the charge-transporting polymer is easily obtained.

[0070] Structural unit T includes, for example, a structural unit represented by the following formula (3) (hereinafter referred to as "structural unit (3)").

[0071] [ka]

[0072] In the formula, Ar represents a substituted or unsubstituted aromatic hydrocarbon group, and PGG represents a group containing a polymerizable functional group. a represents 0 or 1, and z represents an integer of 1 or more.

[0073] The upper limit of z is determined by the structure of Ar. For example, if Ar is a benzene ring, z is 5 or less, and may be 2 or less.

[0074] Structural unit (3) includes, for example, a structural unit represented by the following formula (3a).

[0075] [ka]

[0076] In the formula, R represents either a hydrogen atom or a substituent, independently. An example of a substituent is the substituent Ra.

[0077] At least one R may be a group containing a polymerizable functional group. The number of R groups containing polymerizable functional groups may be, for example, one. R groups that do not contain polymerizable functional groups may be hydrogen atoms.

[0078] The number-average molecular weight of the charge-transport polymer can be adjusted as appropriate, taking into consideration its solubility in the solvent, film-forming properties, etc. From the viewpoint of excellent charge transport properties, the number-average molecular weight may be, for example, 500 or more, 1,000 or more, 2,000 or more, or 5,000 or more. From the viewpoint of maintaining good solubility in the solvent and facilitating the preparation of the ink composition, the number-average molecular weight may be, for example, 1,000,000 or less, 100,000 or less, 50,000 or less, or 30,000 or less.

[0079] The weight-average molecular weight of the charge-transport polymer can be adjusted as appropriate, taking into consideration its solubility in the solvent, film-forming properties, etc. From the viewpoint of excellent charge transport properties, the weight-average molecular weight may be, for example, 1,000 or more, 5,000 or more, 10,000 or more, or 30,000 or more. From the viewpoint of maintaining good solubility in the solvent and facilitating the preparation of the ink composition, the weight-average molecular weight may be, for example, 1,000,000 or less, 700,000 or less, 400,000 or less, 200,000 or less, or 100,000 or less.

[0080] The number-average molecular weight and weight-average molecular weight can be determined by gel permeation chromatography (GPC) using a calibration curve for standard polystyrene.

[0081] When a charge-transporting polymer contains structural units L, the proportion of structural units L is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total number of structural units, from the viewpoint of obtaining sufficient charge transport. Furthermore, considering structural units T and structural units B which are introduced as needed, the proportion of structural units L is preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 85 mol% or less.

[0082] When the charge-transporting polymer contains structural unit B, the proportion of structural unit B 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 improving the durability of organic electronic devices. Furthermore, from the viewpoint of suppressing the increase in viscosity and ensuring good synthesis of the charge-transporting polymer, or from the viewpoint of obtaining sufficient charge transport properties, the proportion of structural unit B is preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less.

[0083] From the viewpoint of improving the properties of organic electronic devices or suppressing viscosity increases and ensuring good synthesis of charge transport polymers, the proportion of structural units T in the charge transport polymer is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more, based on the total structural units. Furthermore, from the viewpoint of obtaining sufficient charge transport properties, the proportion of structural units T is preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less.

[0084] When a charge-transporting polymer has polymerizable functional groups at its ends, from the viewpoint of obtaining good curability, the ratio of structural units T having polymerizable functional groups may be, for example, 5 mol% or more, 20 mol% or more, 40 mol% or more, 60 mol% or more, or 80 mol% or more, based on the total amount of structural units T. The ratio of structural units T having polymerizable functional groups may be 100 mol% or less, and from the viewpoint of obtaining good charge transport, it may be 85 mol% or less, 75 mol% or less, or 65 mol% or less.

[0085] The ratio of structural units can be determined using the amount of monomer corresponding to each structural unit used to synthesize the charge-transport polymer. 1 The average value can be calculated by using the integral values ​​of the spectra derived from each structural unit in the 1H NMR spectrum. For simplicity, if the amount of charge is known, it is preferable to use the value obtained using the amount of charge. The ratios for the terminal groups mentioned above can also be calculated using the amount of charge or 1This can be determined by using 1H NMR spectroscopy.

[0086] Charge-transporting polymers can be produced by various synthetic methods and are not particularly limited. For example, known coupling reactions such as Suzuki coupling, Negishi coupling, Sonogashira coupling, Still coupling, and Buchwald-Hartwig coupling can be used. In Suzuki coupling, a cross-coupling reaction using a Pd catalyst occurs between an aromatic boronic acid derivative and an aromatic halide. By using Suzuki coupling, charge-transporting polymers can be easily synthesized by bonding the desired aromatic rings together. For information on the synthesis method of charge-transporting polymers, see, for example, International Publication No. 2010 / 140553.

[0087] [Optional ingredients] The charge-transporting material may further contain any components other than the ionic compound and the charge-transporting polymer, such as dopants, polymerization initiators, ionic compounds, charge-transporting polymers, and additives. Examples of additives include polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, reduction inhibitors, oxidizing agents, reducing agents, surface modifiers, emulsifiers, defoaming agents, dispersants, and surfactants.

[0088] [Content] The content of the ionic compound may be, for example, 1% by mass or more, 10% by mass or more, or 20% by mass or more relative to the charge transport polymer, from the viewpoint of improving the curability of the charge transport material. From the viewpoint of maintaining good film-forming properties, it may be, for example, 10% by mass or less, 5% by mass or less, or 3% by mass or less relative to the charge transport polymer.

[0089] The content of the charge-transporting polymer may be, for example, 50% by mass or more, 70% by mass or more, or 80% by mass or more, relative to the mass of the charge-transporting material, from the viewpoint of obtaining good charge transport properties. The total content of the charge-transporting polymer and ionic compound may also be 100% by mass relative to the mass of the charge-transporting material.

[0090] <Ink composition> The ink composition contains the charge-transporting material and a solvent capable of dissolving or dispersing the material. By using the ink composition, an organic layer can be easily formed by a simple method such as coating.

[0091] [solvent] As a solvent, water, organic solvents, or mixtures thereof can be used. Organic solvents include alcohols such as methanol, ethanol, and isopropyl alcohol; alkanes such as pentane, hexane, and octane; cyclic alkanes such as cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, tetralin, phenylcyclohexane, and diphenylmethane; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate; and 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, and 2-methoxytoluene. Examples include aromatic ethers such as n, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and 3-phenoxytoluene; 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 dimethyl sulfoxide, tetrahydrofuran, acetone, chloroform, and methylene chloride. Preferably, the mixture consists of aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, and aromatic ethers; more preferably, aromatic hydrocarbons, aromatic ethers, and aromatic esters; and even more preferably, aromatic hydrocarbons.

[0092] [Additives] The ink composition may further contain additives as optional components. Examples of additives include polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, reduction inhibitors, oxidizing agents, reducing agents, surface modifiers, emulsifiers, defoaming agents, dispersants, and surfactants.

[0093] [Content] The solvent content in the ink composition can be determined considering its application to various coating methods. For example, the solvent content may be such that the charge-transporting polymer content relative to the solvent is, for example, 0.1% by mass or more, 0.2% by mass or more, or 0.5% by mass or more. Alternatively, the solvent content may be such that the charge-transporting polymer content relative to the solvent is, for example, 20% by mass or less, 15% by mass or less, or 10% by mass or less.

[0094] <Organic layer> The organic layer is a layer formed using the charge-transporting material or the ink composition, and includes a cured product of the charge-transporting polymer. By using the ink composition, the organic layer can be well formed by a coating method. Examples of coating methods include known methods such as spin coating, casting, immersion, plated printing methods such as letterpress printing, intaglio printing, offset printing, lithographic printing, letterpress-reverse offset printing, screen printing, and gravure printing, and plateless printing methods such as inkjet printing. When forming the organic layer by a coating method, the uncured coating film obtained after coating may be dried using a hot plate or oven to remove the solvent.

[0095] By applying treatments such as light irradiation and heat treatment to the coated film, the polymerization reaction of the charge-transporting polymer can be promoted, and the solubility of the coated film can be changed. By laminating other layers on the cured organic layer (cured film) obtained after the change, it becomes possible to easily create multilayer organic electronic elements. For the method of forming the organic layer, refer to, for example, the description in International Publication No. 2010 / 140553. The heat treatment of the coated film can be carried out in an atmospheric or nitrogen atmosphere. From the viewpoint of improving charge transportability, it is preferable to heat treat the coated film in a nitrogen atmosphere. The ionic compound can particularly improve the solvent resistance of the organic layer when the coated film is heat treated in a nitrogen atmosphere. The heating temperature may be, for example, 110°C or higher, 130°C or higher, or 170°C. The heating temperature may be, for example, 210°C or lower, 180°C or lower, or 140°C or lower.

[0096] The thickness of the cured organic layer is, for example, 0.1 nm or more, 1 nm or more, or 3 nm or more, from the viewpoint of improving the efficiency of charge transport. The thickness of the organic layer is, for example, 300 nm or less, 200 nm or less, or 100 nm or less, from the viewpoint of reducing electrical resistance.

[0097] <Organic Electronics Components> In embodiments of the present invention, the organic electronic element has at least the organic layer. Examples of organic electronic elements include organic EL elements such as organic light-emitting diodes (OLEDs), organic photoelectric conversion elements, and organic transistors. Preferably, the organic electronic element has a structure in which an organic layer is disposed between at least one pair of electrodes.

[0098] <Organic electroluminescent elements (organic EL elements)> In embodiments of the present invention, the organic EL element has at least the organic layer. The organic EL element typically comprises an emissive layer, an anode, a cathode, and a substrate, and optionally includes functional layers such as a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer. Each layer may be formed by vapor deposition or by coating. Known materials can be used to form each layer. For known materials, see, for example, International Publication No. 2010 / 140553. The organic EL element preferably has an organic layer as an emissive layer or a functional layer, more preferably as a functional layer, and even more preferably as at least one of a hole injection layer and a hole transport layer. For the structure and manufacturing method of the organic EL, see, for example, International Publication No. 2010 / 140553.

[0099] The organic layer formed using the charge-transporting material is preferably used as at least one of a hole injection layer and a hole transport layer, and more preferably as at least a hole injection layer. As described above, these layers can be easily formed by using an ink composition containing the charge-transporting material.

[0100] If the organic EL element has an organic layer formed using the charge-transporting material as a hole transport layer, and further has a hole injection layer, known materials can be used for the hole injection layer. It is also preferable to use the charge-transporting material for both the hole injection layer and the hole transport layer.

[0101] <Display elements, lighting devices, display devices> In embodiments of the present invention, the display element comprises the organic EL elements. For example, by using organic EL elements as elements corresponding to red, green, and blue (RGB) pixels, a color display element can be obtained. The image formation method includes a simple matrix type in which individual organic EL elements arranged on a panel are directly driven by electrodes arranged in a matrix, and an active matrix type in which thin-film transistors are placed in each element for driving.

[0102] The lighting device includes the aforementioned organic EL element. The display device includes the lighting device and a liquid crystal element as a display means. For example, the display device can be a display device that uses the lighting device as a backlight and a known liquid crystal element as a display means, i.e., a liquid crystal display device.

[0103] <Organic photoelectric conversion element> In embodiments of the present invention, the organic photoelectric element includes at least the organic layer. The organic photoelectric element includes organic solar cells, organic image sensors, and the like. The organic photoelectric element comprises, for example, a photoelectric conversion layer, electrodes, and a substrate. Furthermore, it may have other layers such as a buffer layer and an electron transport layer for the purpose of improving conversion efficiency or stability in air. The organic photoelectric element has at least the organic layer, and the organic layer can be used as a photoelectric conversion layer and a buffer layer, and is preferably used as a buffer layer. Therefore, an example of an organic photoelectric element has an anode, an organic layer as a buffer layer, a photoelectric conversion layer, and a cathode in this order, and may have any additional layers between these layers.

[0104] Any material can be used for the photoelectric conversion layer as long as it absorbs light, causes charge separation, and generates electromotive force. The material of the photoelectric conversion layer may, for example, be a mixture of a p-type organic semiconductor and an n-type organic semiconductor from the viewpoint of conversion efficiency. Examples of p-type organic semiconductors include polymers or oligomers such as oligothiophenes, polyalkylthiophenes, poly(3-hexylthiophene) (P3HT), and polyphenylene vinylene (PPV); porphyrins, phthalocyanines, copper phthalocyanines; and derivatives thereof. Examples of n-type organic semiconductors include polymers or oligomers containing -CN or -CF3 groups such as CN-poly(phenylene-vinylene) (CN-PPV), MEH-CN-PPV, and their -CF3-substituted polymers; polymers or oligomers such as poly(fluorene) derivatives and fluorene-benzothiadiazole copolymers; and fullerene (C 60Examples include naphthalenetetracarboxylic anhydride (NTCDA), perylenetetracarboxylic anhydride (PTCDA), quinacridone; and derivatives thereof. Furthermore, from the viewpoint of conversion efficiency, flexibility, productivity, etc., the material of the photoelectric conversion layer may be a material containing a perovskite compound.

[0105] The method for forming the photoelectric conversion layer is not particularly limited and may be formed by vapor deposition or by coating. Forming by coating is more preferable because it allows for the inexpensive manufacture of organic photoelectric conversion elements. As a method for forming by coating, the method described for forming the light-emitting layer can be used.

[0106] The organic photoelectric conversion element may have the above-mentioned buffer layer in addition to the photoelectric conversion layer, and may also have layers such as an electron transport layer. The buffer layer may be the organic layer, and the electron transport layer may be a layer containing LiF, TiOx, ZnOx, etc. [Examples]

[0107] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples.

[0108] <Synthesis of ionic compounds> (Synthesis of ionic compound 1) Ionic compound 1, represented by the structural formula below, was synthesized as follows. 3.47 g (30 mmol) of pyridine hydrochloride was mixed with 30 g of acetone and stirred to form a solution. Then, 233.77 g (33 mmol) of a 10% aqueous solution of sodium tetrakis (pentafluorophenyl) borate was added and the mixture was stirred for 1 hour. 30 mL of deionized water was added and the mixture was washed three times at 50°C. A white solid was obtained by filtration. The obtained solid was washed with deionized water, dissolved in 30 mL of methanol, and insoluble matter was removed using a syringe filter (polytetrafluoroethylene (PTFE) membrane, pore size 0.2 μm). The solvent was then removed by vacuum distillation to obtain ionic compound 1.

[0109] [ka]

[0110] (Synthesis of ionic compound 2) Ionic compound 2, represented by the structural formula below, was synthesized as follows. 3.15 g (30 mmol) of 4-vinylpyridine was mixed with 75 g of acetone and 15 g of pure water and stirred to form a solution. Then, 10.96 g of 10% by mass aqueous solution of hydrogen chloride was slowly added dropwise, and after the addition was complete, the mixture was stirred for 1 hour. The solvent was removed from this solution under reduced pressure until a solid precipitated. Next, 233.77 g (33 mmol) of 10% by mass aqueous solution of sodium tetrakis (pentafluorophenyl) borate was mixed and stirred for 1 hour. 30 mL of deionized water was added and the mixture was washed three times at 50°C. A white solid was obtained by filtration. The obtained solid was washed with deionized water, dissolved in 30 mL of methanol, and insoluble matter was removed using a syringe filter (PTFE membrane, pore size 0.2 μm). The solvent was then removed under reduced pressure to obtain ionic compound 2.

[0111] [ka]

[0112] (Synthesis of ionic compound 3) Ionic compound 3, represented by the following structural formula, was prepared by the same method as in the synthesis of ionic compound 2, except that 4-dimethylaminopyridine (30 mmol) was used instead of 4-vinylpyridine.

[0113] [ka]

[0114] (Synthesis of ionic compound 4) Ionic compound 4, represented by the following structural formula, was prepared by the same method as in the synthesis of ionic compound 2, except that 4-cyanopyridine (30 mmol) was used instead of 4-vinylpyridine.

[0115] [ka]

[0116] (Synthesis of ionic compound 5) Ionic compound 5, represented by the following structural formula, was prepared by the same method as in the synthesis of ionic compound 2, except that 2-pentylpyridine (30 mmol) was used instead of 4-vinylpyridine.

[0117] [ka]

[0118] (Synthesis of ionic compound 6) Ionic compound 6, represented by the following structural formula, was prepared by the same method as in the synthesis of ionic compound 2, except that 2,6-bis(t-butyl)pyridine (30 mmol) was used instead of 4-vinylpyridine.

[0119] [ka]

[0120] (Synthesis of ionic compound 7) Ionic compound 7, represented by the following structural formula, was prepared by the same method as in the synthesis of ionic compound 2, except that quinoline (30 mmol) was used instead of 4-vinylpyridine.

[0121] [ka]

[0122] (Synthesis of ionic compound 8) Ionic compound 8, represented by the following structural formula, was prepared by the same method as in the synthesis of ionic compound 2, except that N,N-dimethyloctadecylamine (30 mmol) was used instead of 4-vinylpyridine.

[0123] [ka]

[0124] <Preparation of charge-transporting polymers> (Preparation of Pd catalyst) In a glove box under a nitrogen atmosphere at room temperature, a fluoropolymer-coated magnetic stirring bar was placed in a glass sample vial, 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 to obtain a solution. Similarly, a fluoropolymer-coated magnetic stirring 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 to obtain a solution. These solutions were mixed and stirred at 80°C for 2 hours. Insoluble matter was removed using a PTFE membrane filter with a pore size of 0.2 μm, and the resulting solution was used as the Pd catalyst solution. All solvents were degassed by nitrogen bubbling for at least 30 minutes before use.

[0125] (Synthesis of charge-transporting polymers) 2.51 g of monomer A, 0.88 g of monomer B, and 0.99 g of monomer C were weighed into a 100 mL three-necked round-bottom glass flask. 3.89 mL of a toluene solution of 1% by mass trioctylmethylammonium chloride, 3.74 mL of a 3 M potassium hydroxide aqueous solution, and 40.54 mL of toluene were added. All solvents were degassed by nitrogen bubbling for at least 30 minutes before use. A reflux condenser and a nitrogen gas flow tube were then attached to the flask, and the flask was immersed in an oil bath heated to 120 °C. The mixture was stirred under reflux for 10 minutes to dissolve the monomers. Subsequently, 1.00 mL of Pd catalyst solution was added to the liquid in the flask, and the mixture was heated under reflux for 2 hours. The entire reaction was carried out under a nitrogen atmosphere.

[0126] After the reaction was complete, the flask was removed from the oil bath, 10 mL of 0.1 mol / L aqueous solution of sodium N,N-diethyldithiocarbamate was added, and the mixture was stirred for 30 minutes. The reaction mixture was allowed to stand for 10 minutes, the separated aqueous layer was removed, and the organic layer was washed twice with water. The organic layer was filtered through a 0.2 μm pore size PTFE membrane filter, and the filtrate was poured into a methanol-water (9:1) mixture. The resulting precipitate was filtered off and washed with methanol. The precipitate was further washed with ethyl acetate, and the remaining solid was filtered by suction and washed with methanol. After washing, the solid was vacuum dried to obtain the charge-transporting polymer. The number-average molecular weight of the obtained charge-transporting polymer was 16,000, and the weight-average molecular weight was 47,000.

[0127] [ka]

[0128] (Measurement of number-average molecular weight, measurement of weight-average molecular weight) The number-average molecular weight and weight-average molecular weight of charge-transporting polymers were measured using gel permeation chromatography (GPC) under the following conditions. Equipment: High-performance liquid chromatograph Prominence, manufactured by Shimadzu Corporation. Liquid transfer pump (LC-20AD) Degassing unit (DGU-20A) Autosampler (SIL-20AHT) Column oven (CTO-20A) PDA detector (SPD-M20A) Differential refractive index detector (RID-20A) Column: Gelpack GL-A160S (serial number: 686-1J27) GL-A150S (serial number: 685-1J27) Eluent: Tetrahydrofuran (THF) (for HPLC, contains stabilizer) Fujifilm Wako Pure Chemical Industries, Ltd. Flow rate: 1mL / min Column temperature: 40℃ Detection wavelength: 254nm Molecular weight standard material: PStQuick B / C / D, Tosoh Corporation

[0129] (Evaluation of solvent resistance) Ionic compounds 1-8 were weighed at 10 mg each into glass vials and dissolved in 5 mL of cyclopentanone to obtain ionic compound solutions. Next, 15.0 mg of charge-transporting polymer was weighed into a glass sample tube and dissolved in 0.96 mL of cyclopentanone to prepare a charge-transporting polymer solution. The ionic compound solution was added to the charge-transporting polymer solution so that the ionic compound content was 0.1 mol% relative to the charge-transporting polymer, and the solutions were mixed by shaking in a vortex mixer for 3 minutes to prepare an ink composition for solvent solubility evaluation. The ink composition for solvent solubility evaluation was subjected to 3,000 mins under atmospheric pressure on a quartz plate. -1 The plates were spin-coated. Next, the spin-coated quartz plates were placed in a glove box under a nitrogen atmosphere and heated on a hot plate under a nitrogen atmosphere at 120°C, 150°C, or 200°C for 30 minutes to cure and form an organic layer. The formed quartz plates with the organic layer were immersed in 10 mL of toluene under air and at room temperature and left to stand for 10 minutes. The absorbance (Abs) of the absorption maximum (λmax) in the visible ultraviolet (UV-vis) spectroscopy (UV-vis) spectrum of the quartz plates with the organic layer was measured before and after immersion in toluene, and the residual film percentage (%) of the organic layer was calculated using the following formula. Absorbance A is the absorbance of the organic layer before immersion, and absorbance B is the absorbance of the organic layer after immersion in toluene. The measurement results are shown in Table 1.

[0130]

number

[0131] [Table 1]

[0132] (Fabrication of organic hole-only devices) Ionic compounds 1-8 were weighed at 10 mg each into glass vials and dissolved in 5 mL of cyclopentanone to obtain ionic compound solutions. Next, 35.0 mg of charge-transporting polymer was weighed into a glass sample tube and dissolved in 0.84 mL of cyclopentanone to prepare a charge-transporting polymer solution. The ionic compound solution was added to the charge-transporting polymer solution so that the ionic compound amounted to 0.1 mol% relative to the charge-transporting polymer, and the solutions were mixed by shaking in a vortex mixer for 3 minutes to prepare an ink composition for fabricating organic hole-only device elements.

[0133] Under atmospheric pressure, an ink composition for fabricating organic hole-only device elements is applied to a glass substrate patterned with ITO to a width of 1.6 mm, at a rotation speed of 3,000 min⁻¹. ー1 The coated film was formed by spin coating. Next, the glass substrate was placed on a hot plate inside a glove box with a nitrogen atmosphere and heated at 120°C for 30 minutes to cure the coated film and form an organic layer.

[0134] The organic layer was formed with a thickness of 100 nm (±5 nm). The thickness of the organic layer was determined by forming an organic layer on a quartz substrate under the above conditions, measuring the thickness at multiple points using a contact-type film thickness gauge, and taking the average value as the thickness of the organic layer.

[0135] The glass substrate having the organic layer obtained as described above was transferred to a vacuum deposition machine, and an aluminum (100 nm) film was deposited on the organic layer by evaporation. Subsequently, a sealing process was performed to fabricate an organic hole-only device (HOD).

[0136] (Evaluation of Organic HOD) When a voltage was applied to the organic HOD, current flowed, confirming that the organic layer possesses hole injection capabilities. The current density of the organic HOD was measured at a driving voltage of 3.0V. The measurement results are shown in Table 2.

[0137] [Table 2]

Claims

1. A charge transport material comprising an ionic compound containing a cation having at least one selected from the group consisting of a pyridine ring, a quinoline ring, an isoquinoline ring, and an acridine ring, and a charge transport polymer having a polymerizable functional group.

2. The charge transport material according to claim 1, wherein the cation comprises at least one selected from the group consisting of a cation represented by the following formula (Py1), a cation represented by the following formula (Py2), a cation represented by the following formula (Py3), and a cation represented by the following formula (Py4). 【Chemistry 1】 (In the formula, R ２ ~R ６ Each of these independently represents a hydrogen atom or a substituent. 【Chemistry 2】 (In the formula, R ２ ~R ８ Each of these independently represents a hydrogen atom or a substituent. 【Transformation 3】 (In the formula, R １ and R ３ ~R ８ Each of these independently represents a hydrogen atom or a substituent. 【Chemistry 4】 (wherein, R １ to R ９ each independently represents a hydrogen atom or a substituent.)

3. The aforementioned ionic compound is represented by the formula (Py1), R ２ ~R ６ The charge transport material according to claim 2, wherein at least one of the following comprises a cation selected from the group consisting of halogen, alkyl group, haloalkyl group, aryl group, heteroaryl group, cyano group; N comprising a group to which N is bonded to a pyridine ring; O comprising a group to which O is bonded to a pyridine ring; P comprising a group to which P is bonded to a pyridine ring; and S comprising a group to which S is bonded to a pyridine ring.

4. The charge transport material according to claim 2, wherein the ionic compound contains a boron-containing anion.

5. The charge transport material according to claim 3, wherein the ionic compound comprises a substituted or unsubstituted tetrakis(aryl)boron anion.

6. The charge transport material according to any one of claims 1 to 5, wherein the polymerizable functional group comprises at least one selected from the group consisting of an oxyranyl group, an oxetanyl group, an ethenyl group, a propargyl group, an ethenyloxy group, a propargyloxy group, an ethenylphenyl group, and a propargylphenyl group.

7. The charge-transporting polymer has a structural unit comprising at least one structure selected from the group consisting of an aromatic amine structure, a carbazole structure, a thiophene structure, a benzene structure, a pyrrole structure, a furan structure, and a fluorene structure, according to any one of claims 1 to 5.

8. The charge transport material according to any one of claims 1 to 5, wherein the charge transport polymer includes a branched polymer.

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

10. An organic electronic element having an organic layer formed using the ink composition described in claim 9.

11. An organic electroluminescent element having an organic layer formed using the ink composition described in claim 9.

12. A photoelectric conversion element having an organic layer formed using the ink composition described in claim 9.

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