Polymer, composition for organic electroluminescent element, organic electroluminescent element, organic EL display device, and organic EL illumination

Abstract

The present invention addresses the problem of providing: a polymer which does not melt at low temperatures in a short period of time, has high hole injection transport energy, and has high durability; and a composition containing the polymer. The present invention relates to a polymer comprising a repeating unit represented by the following formula (1), and a composition comprising the polymer and an electron-accepting compound represented by a specific formula. [Formula 1] (definitions of substituents are as described in the specification)

Description

Technical Field

[0001] The present invention relates to a polymer, and in particular to a polymer that can be used as a hole injection layer and a hole transport layer of an organic electroluminescent element, a composition for an organic electroluminescent element containing the polymer, and an organic EL display and an organic EL lighting having the organic electroluminescent element. Background Art

[0002] As methods for forming the organic layer in an organic electroluminescent element, vacuum evaporation and wet film-forming methods can be cited. Since vacuum evaporation is easy to stack, it has the following advantages: it is easy to improve the charge injection from the anode and / or cathode, and it is easy to confine the excitons in the light-emitting layer. On the other hand, the wet film-forming method has the following advantages: it does not require a vacuum process, it is easy to apply to a large area, and by using a coating liquid in which a plurality of materials having various functions are mixed, a layer containing a plurality of materials having various functions can be easily formed. However, the current situation is that the wet film-forming method is difficult to stack, and therefore has poor driving stability compared to elements using the vacuum evaporation method, and except for some, it has not yet reached a practical level.

[0003] Therefore, for lamination using wet film formation methods, charge-transporting polymers with crosslinking groups that do not melt after coating are desired and are being developed. Specifically, Patent Documents 1 to 4 disclose polymers having benzocyclobutene as a crosslinking group, which exhibits excellent durability, and an arylamine structure as a charge-transporting site. Patent Document 5 discloses a polymer having 1,2-dihydrocyclobuteno[a]naphthalene as a crosslinking group and an arylamine structure as a charge-transporting site, which exhibits excellent transport properties. Prior art literature Patent Literature

[0004] Patent Document 1: International Publication No. 2009 / 123269 Patent Document 2: International Publication No. 2011 / 078387 Patent Document 3: International Publication No. 2011 / 093428 Patent Document 4: International Publication No. 2013 / 191137 Patent Document 5: Japanese Patent Application Publication No. 2019-173032 Summary of the Invention Problems to be solved by the invention

[0005] According to the research of the present inventors, in order to prevent the benzocyclobutene-containing polymers described in Patent Documents 1 to 4 from melting, a large amount of energy is required, and high-temperature and long-term baking is required, which causes problems. Specifically, it is known that the heat resistance of components such as substrates, partitions, and insulating films must be improved, and baking takes a long time, so only small quantities of components can be produced. In addition, in order to prevent the 1,2-dihydrocyclobutene-[a]naphthalene-containing polymer described in Patent Document 5 from melting, although the baking temperature can be lowered compared to the baking temperature for preventing the benzocyclobutene-containing polymers described in Patent Documents 1 to 4 from melting, a baking temperature of 210°C or above is still required, and the baking temperature cannot be sufficiently lowered.

[0006] Therefore, the present invention aims to provide a polymer and a composition containing the polymer that does not melt at low temperatures for a short period of time, has high hole injection and transport capabilities, and is highly durable. Furthermore, the present invention aims to provide an organic electroluminescent device that can be easily manufactured and has a long driving life. Technical solutions to the problem

[0007] The present inventors have conducted intensive studies and, as a result, have found that the above-mentioned problems can be solved by using a polymer having a specific cross-linking group, thereby completing the present invention.

[0008] That is, the gist of the present invention is as follows.

[0009] A first embodiment of the present invention relates to a polymer containing a repeating unit represented by the following formula (1).

[0010] [Chemistry 1]

[0011] (In formula (1), Ar 1 It represents a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the above divalent aromatic hydrocarbon groups and the above divalent aromatic heterocyclic groups are linked directly or via a linking group. Ar 2 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by linking a plurality of groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups. Ar 1 with Ar 2 A ring may be formed via a single bond or a linking group, or may not be formed. Ar 1 With or without substituents. Ar 2 With or without substituents. Ar 2 It has at least one cross-linking group represented by formula (2) or formula (3).

[0012] [Chemistry 2]

[0013] [Chemistry 3]

[0014] (In formula (2) and formula (3), Ar 3 ~Ar 5 Each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent, Ar 6 represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent, R 1 represents a hydrogen atom, or a monovalent alkyl group which may be substituted, a monovalent alkenyl group which may be substituted, a monovalent alkynyl group which may be substituted, a monovalent alkoxy group which may be substituted, a monovalent aromatic hydrocarbon group, or a monovalent aromatic heterocyclic group which may be substituted, HA 1 represents an oxygen atom or a sulfur atom, n1 represents an integer from 1 to 5, n2 represents an integer from 0 to 5, n3 represents an integer from 0 to 5, "-*" indicates the position of bonding with formula (1).

[0015] A second aspect of the present invention relates to a polymer, wherein, in the polymer of the first aspect, Ar 2 Having HA selected from formula (2) 1 The cross-linking group is an oxygen atom and HA in formula (3) 1 At least one of the group consisting of cross-linking groups consisting of oxygen atoms.

[0016] A third embodiment of the present invention relates to a polymer, wherein in the polymer of embodiment 1 or 2, Ar 2 Having Ar selected from formula (2) 3 is a cross-linking group of a benzene ring and Ar in formula (3) 6 At least one of the group consisting of cross-linking groups which is a phenyl group.

[0017] A fourth aspect of the present invention relates to a polymer, wherein, in the polymer according to any one of aspects 1 to 3, The crosslinking group represented by the formula (2) is selected from the following structural groups.

[0018] [Chemistry 4]

[0019] (“-*” indicates the position of bonding with formula (1))

[0020] A fifth aspect of the present invention relates to a polymer according to any one of aspects 1 to 3, wherein the crosslinking group represented by the formula (3) is selected from the following structural groups.

[0021] [Chemistry 5]

[0022] [Chemistry 6]

[0023] (“-*” indicates the position of bonding with formula (1))

[0024] A sixth aspect of the present invention relates to a polymer, wherein, in the polymer according to any one of aspects 1 to 5, The repeating unit represented by formula (1) is a repeating unit represented by the following formula (1-1), (1-2), (1-3), (1-4) or (1-5).

[0025] [Chemistry 7]

[0026] (In formula (1-1), Ar 2 and Ar in the formula (1) 2 same. X is -C(R 207 )(R 208 )-、-N(R 209 )-or-C(R 211 )(R 212 )-C(R 213 )(R 214 )-. R 201 、R 202 、R 221 and R 222 Each is independently an alkyl group which may have a substituent. R 207 ~R 209 and R 211 ~R 214 Each is independently a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. a and b are each independently an integer of 0-4. c is an integer from 0 to 3. d is an integer from 0 to 4. i and j are each independently an integer of 0-3. Where a×c+b×d+i+j is greater than or equal to 1.)

[0027] [Chemistry 8]

[0028] (In formula (1-2), Ar 2 and Ar in the formula (1) 2 same. R 303 and R 306 Each independently represents an alkyl group which may have a substituent. R 304 and R 305 Each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. l is 0 or 1. m is 1 or 2. n is 0 or 1. p is 0 or 1. q is 0 or 1.)

[0029] [Chemistry 9]

[0030] (In formula (1-3), Ar 2 and Ar in the formula (1) 2 same. Ar 41 It represents an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the above divalent aromatic hydrocarbon groups and the above divalent aromatic heterocyclic groups are linked directly or via a linking group. R 441 and R 442 Each independently represents an alkyl group which may have a substituent. t is 1 or 2. u is 0 or 1. r and s are each independently an integer of 0-4. Here, r×t+s×u is greater than or equal to 1.)

[0031] [Chemistry 10]

[0032] (In formula (1-4), Ar 2 and Ar in the formula (1)2 same. R 517 ~R 519 Each independently represents an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group. f, g, and h are each independently an integer of 0-4. e is an integer from 0 to 3. However, when g is an integer greater than or equal to 1, e is an integer greater than or equal to 1. Wherein, f+e×g+h is greater than or equal to 1.)

[0033] [Chemistry 11]

[0034] (In formula (1-5), Ar 2 and Ar in the formula (1) 2 same. n60 is an integer from 1 to 5.)

[0035] A seventh aspect of the present invention relates to a polymer, wherein, in the polymer of the sixth aspect, The repeating unit represented by the above formula (1-1) is a repeating unit represented by the following formula (1-1-1). [Chemistry 12]

[0036] (In formula (1-1-1), Ar 2 , X, R 201 、R 202 、R 221 、R 222 , a, b, c, d and Ar in the formula (1-1) 2 , X, R 201 、R 202 、R 221 、R 222 , a, b, c, d are the same. a1, a2, b1, b2, i1, i2, j1, and j2 each independently represent 0 or 1. Among them, a, b, c, d, a1, a2, b1, b2, i1, i2, j1, and j2 satisfy any one of the following conditions (1) and (2). Condition (1) At least one of a1, a2, and a is an integer greater than or equal to 1, at least one of b1, b2, and b is an integer greater than or equal to 1, c is an integer greater than or equal to 1, and d is an integer greater than or equal to 1. When c is 1, at least one of a1 or a2 is 1, and when d is 1, at least one of b1 or b2 is 1. Condition (2) At least one of i1, i2, j1, and j2 is 1. Ring A1 refers to rings with or without R at specific positions. 201 divalent benzene ring. Ring A2 refers to a ring with or without R 201 A divalent group formed by connecting c-1 benzene rings, wherein when c is 1, it refers to a monocyclic divalent benzene ring. Ring A3 refers to a divalent condensed ring formed by further bonding a biphenyl structure to X. Ring A4 refers to a ring with or without R 202 A divalent group formed by connecting d-1 benzene rings, wherein when d is 1, it refers to a monocyclic divalent benzene ring. Ring A5 refers to rings with or without R at specific positions. 202 divalent benzene ring.)

[0037] An eighth aspect of the present invention relates to a polymer, wherein, in the polymer of the sixth aspect, Ar present in the repeating unit represented by formula (1) 1 ~Ar 6 、Ar 41 、R 201 、R 202 、R 221 、R 222 、R 207 ~R 209 、R 211 ~R 214 、R 301 、R 304 ~R 306 、R 441 、R 442 and R 517 ~R 519 None of them has a substituent.

[0038] A ninth aspect of the present invention relates to a composition comprising the polymer according to any one of the first to eighth aspects and an electron-accepting compound.

[0039] A tenth aspect of the present invention relates to a composition comprising the composition of the ninth aspect: The electron-accepting compound is represented by the following formula (81).

[0040] [Chemistry 13]

[0041] (In formula (81), 5 R 81 , 5 Rs 82 , 5 Rs 83 , 5 Rs 84 Each is independent and R 81 ~R 84 Each is independently a hydrogen atom, a deuterium atom, a halogen atom, an aromatic hydrocarbon group having 6 to 50 carbon atoms which may be substituted, an aromatic heterocyclic group having 3 to 50 carbon atoms which may be substituted, a fluorine-substituted alkyl group having 1 to 12 carbon atoms, or a crosslinking group. Ph 1 、Ph 2 、Ph 3 、Ph 4 are symbols representing individual benzene rings. X + represents the counter cation. Wherein, formula (81) has at least 2 cross-linking groups.

[0042] Aspect 11 of the present invention relates to a composition comprising the composition of aspect 10, *-Ph in the formula (81) 1 -(R 81 )5. *-Ph 2 -(R 82 )5. *-Ph 3 -(R 83 )5. *-Ph 4 -(R 84 )5, at least one is a group represented by the following formula (84) having 4 fluorine atoms.

[0043] [Chemistry 14]

[0044] (In formula (84), * represents the position of bonding with boron B in formula (81), F4 represents substitution with four fluorine atoms, R 85 represents an aromatic hydrocarbon group which may have a substituent and / or a cross-linking group, or a cross-linking group.)

[0045] A twelfth aspect of the present invention relates to a composition comprising the composition of embodiment 10 or 11: The electron-accepting compound represented by the formula (81) has at least one crosslinking group selected from the crosslinking group group T below, which is represented by formulas (X1) to (X17). <Crosslinking Group T>

[0046] [Chemistry 15]

[0047] (In formulae (X1) to (X17), Q represents a direct bond or a linking group. “*” indicates the bonding position. R in formula (X3), formula (X4), formula (X5) and formula (X9) 110 represents a hydrogen atom or an alkyl group which may have a substituent. In formulae (X1) to (X3), the benzene ring and the naphthalene ring may or may not have a substituent. Furthermore, the substituents may be bonded to each other to form a ring or may not form a ring. In formula (X1) and formula (X2), the cyclobutene ring may have a substituent.

[0048] A thirteenth aspect of the present invention relates to a composition comprising the composition of the twelfth aspect: The electron-accepting compound represented by the formula (81) has at least one crosslinking group selected from the group consisting of the formulas (X1) to (X3).

[0049] A fourteenth aspect of the present invention relates to a composition comprising the composition according to any one of aspects 9 to 13: Also contains solvent.

[0050] A fifteenth aspect of the present invention relates to a method for producing an organic electroluminescent element. The organic electroluminescent element has an anode and a cathode on a substrate and an organic layer between the anode and the cathode, wherein the manufacturing method includes the following steps: The method comprises using the composition of embodiment 14 and forming the organic layer by a wet film forming method.

[0051] A sixteenth aspect of the present invention relates to a method for producing an organic electroluminescent element, which is the method for producing an organic electroluminescent element according to the fifteenth aspect, wherein: The organic layer is located between the anode and the light-emitting layer.

[0052] A seventeenth embodiment of the present invention relates to an organic electroluminescent element. It has an anode and a cathode on a substrate and an organic layer between the anode and the cathode, wherein the organic layer contains a crosslinked reaction product of a polymer containing a repeating unit represented by the following formula (1) and an electron-accepting compound.

[0053] [Chemistry 16]

[0054] (In formula (1), Ar 1It represents a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the above divalent aromatic hydrocarbon groups and the above divalent aromatic heterocyclic groups are linked directly or via a linking group. Ar 2 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by linking a plurality of groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups. Ar 1 with Ar 2 A ring may be formed via a single bond or a linking group, or may not be formed. Ar 1 With or without substituents. Ar 2 With or without substituents. Ar 2 It has at least one cross-linking group represented by formula (2) or formula (3).

[0055] [Chemistry 17]

[0056] [Chemistry 18]

[0057] (In formula (2) and formula (3), Ar 3 ~Ar 5 Each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent, Ar 6 represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent, R 1 represents a hydrogen atom, or a monovalent alkyl group which may be substituted, a monovalent alkenyl group which may be substituted, a monovalent alkynyl group which may be substituted, a monovalent alkoxy group which may be substituted, a monovalent aromatic hydrocarbon group, or a monovalent aromatic heterocyclic group which may be substituted, HA 1 represents an oxygen atom or a sulfur atom, n1 represents an integer from 1 to 5, n2 represents an integer from 0 to 5, n3 represents an integer from 0 to 5, "-*" indicates the position of bonding with formula (1).

[0058] An eighteenth embodiment of the present invention relates to an organic electroluminescent device according to the seventeenth embodiment, wherein the electron-accepting compound is represented by the following formula (81).

[0059] [Chemistry 19]

[0060] (In formula (81), 5 R 81 , 5 Rs 82 , 5 Rs 83 , 5 Rs 84 Each is independent and R 81 ~R 84 Each is independently a hydrogen atom, a deuterium atom, a halogen atom, an aromatic hydrocarbon group having 6 to 50 carbon atoms which may be substituted, an aromatic heterocyclic group having 3 to 50 carbon atoms which may be substituted, a fluorine-substituted alkyl group having 1 to 12 carbon atoms, or a crosslinking group. Ph 1 、Ph 2 、Ph 3 、Ph 4 are symbols representing individual benzene rings. X + represents the counter cation. Wherein, formula (81) has at least 2 cross-linking groups.

[0061] A nineteenth embodiment of the present invention relates to an organic electroluminescent element. It is manufactured using the method for manufacturing an organic electroluminescent element of embodiment 15 or 16.

[0062] A 20th aspect of the present invention relates to a display device including the organic electroluminescent element according to the 17th or 18th aspect.

[0063] A twenty-first aspect of the present invention relates to a lighting device including the organic electroluminescent element according to the seventeenth or eighteenth aspect. Effects of the Invention

[0064] According to the present invention, an organic electroluminescent element having a long driving life can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic cross-sectional view showing a structural example of the organic electroluminescent element of the present invention. Reference numerals 1 substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5. Luminescent layer 6 Electron Transport Layer 7 Cathode 8 Organic electroluminescent elements DETAILED DESCRIPTION

[0066] Hereinafter, embodiments of a composition, an organic electroluminescent element, a method for manufacturing the same, a display device, and an illuminating device according to one embodiment of the present invention will be described in detail. The following description is a first embodiment as an example (representative example) of an embodiment of the present invention, but the present invention is not limited to these contents as long as it does not exceed its purport. In the present invention, “may have a substituent” means that the compound may have one or more substituents.

[0067] [definition] Hereinafter, when the structures of the polymer having a crosslinking group and the electron-accepting compound having a crosslinking group of the present invention are described in detail, unless otherwise specified, the common partial structures are the following structures.

[0068] <Aromatic heterocyclic group> The aromatic heterocyclic group refers to a monovalent, divalent, or trivalent or higher-valent aromatic heterocyclic structure depending on the bonding state in the structure of the compound to be described later. The number of carbon atoms in the aromatic heterocyclic structure is generally not limited, but is preferably 3 to 60 carbon atoms. The upper limit of the carbon number is more preferably 48 or less carbon atoms, and more preferably 30 or less carbon atoms. Specifically, examples include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a pyridine ring, a quinazoline ring, a quinazolinone, an azulene ring, or a group formed by connecting multiple thereof. When multiple aromatic heterocycles are connected, they may be connected with the same structure or with different structures. When a plurality of aromatic heterocyclic rings are linked together, generally, a structure in which 2 to 10 rings are linked together can be used, and a structure in which 2 to 5 rings are linked together is preferred. The aromatic heterocyclic structure is preferably a thiophene ring, a benzothiophene ring, a pyrimidine ring, a triazine ring, a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring.

[0069] <Crosslinking Group> Here, a crosslinking group refers to a group that reacts with other crosslinking groups located near the crosslinking group to form a new chemical bond upon exposure to heat and / or active energy rays. In this case, the reactive group may be the same group as the crosslinking group or a different group.

[0070] <Substituent Group> Unless otherwise specified, a substituent is an arbitrary group, and is preferably a group selected from the following substituent group Z. In addition, when it is described that a substituent that may be present is selected from the substituent group Z or a substituent that may be present is preferably selected from the substituent group Z, preferred substituents are also as described in the substituent group Z below.

[0071] <Substituent Group Z> The substituent group Z is a group consisting of an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, and an aromatic heterocyclic group. These substituents may have any of linear, branched, and cyclic structures.

[0072] More specifically, the substituent group Z includes the following structures. A linear, branched or cyclic alkyl group having 1 or more, preferably 4 or more, and 24 or less, preferably 12 or less, more preferably 8 or less, and more preferably 6 or less. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl. The carbon number of the alkenyl group is usually 2 or more, and usually 24 or less, and preferably 12 or less. Specific examples include vinyl group and the like. The carbon number of the alkynyl group is usually 2 or more, and usually 24 or less, and preferably 12 or less. Specific examples include ethynyl and the like. An alkoxy group having 1 to 24 carbon atoms, preferably 12 or less. Specific examples include a methoxy group and an ethoxy group. An aryloxy group or heteroaryloxy group having 4 or more, preferably 5 or more, and 36 or less, preferably 24 or less carbon atoms. Specific examples include a phenoxy group, a naphthyloxy group, and a pyridyloxy group. An alkoxycarbonyl group having 2 or more and 24 or less, preferably 12 or less carbon atoms. Specific examples include a methoxycarbonyl group and an ethoxycarbonyl group. A dialkylamino group having 2 or more carbon atoms and 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples include dimethylamino and diethylamino groups. A diarylamino group having 10 or more, preferably 12 or more, and 36 or less, preferably 24 or less carbon atoms. Specific examples include diphenylamino, ditolylamino, and N-carbazolyl groups. An arylalkylamino group having 7 or more carbon atoms and 36 or less, preferably 24 or less carbon atoms. Specific examples include phenylmethylamino. An acyl group having 2 or more and 24 or less, preferably 12 or less carbon atoms. Specific examples include acetyl and benzoyl. Halogen atoms such as fluorine atoms and chlorine atoms are preferred. A halogenated alkyl group having 1 or more carbon atoms and 12 or less carbon atoms, preferably 6 or less carbon atoms. Specific examples thereof include trifluoromethyl and the like. An alkylthio group having 1 or more carbon atoms, and usually 24 or less, and preferably 12 or less carbon atoms. Specific examples include a methylthio group and an ethylthio group. An arylthio group having 4 or more, preferably 5 or more, and 36 or less, preferably 24 or less carbon atoms. Specific examples include phenylthio, naphthylthio, and pyridylthio. The silyl group has a carbon number of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less. Specific examples include a trimethylsilyl group and a triphenylsilyl group. A silyloxy group having 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less carbon atoms. Specific examples include a trimethylsilyloxy group and a triphenylsilyloxy group. cyano group. An aromatic hydrocarbon group having 6 or more carbon atoms and 36 or less, preferably 24 or less carbon atoms. Specific examples include a phenyl group, a naphthyl group, and a group formed by linking a plurality of phenyl groups. An aromatic heterocyclic group having 3 or more, preferably 4 or more, and 36 or less, preferably 24 or less carbon atoms. Specific examples include thienyl and pyridyl.

[0073] The substituents may have any structure of a linear, branched or cyclic structure. When the above substituents are adjacent, the adjacent substituents may be bonded to each other to form a ring. Preferred ring sizes are four-membered rings, five-membered rings, and six-membered rings, with specific examples being cyclobutane rings, cyclopentane rings, and cyclohexane rings.

[0074] Among the above-mentioned substituent group Z, an alkyl group, an alkoxy group, an aromatic hydrocarbon group, and an aromatic heterocyclic group are preferred.

[0075] Each substituent in the above-mentioned substituent group Z may further have a substituent. Examples of such substituents include the same groups as those in the above-mentioned substituent group Z or crosslinking groups. Preferably, the substituent has no further substituent, or the substituent further possesses an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, or a phenyl group. From the perspective of charge transport properties, it is more preferable to have no further substituent. When the substituent that each substituent of the above substituent group Z may further have is a crosslinking group, the crosslinking group is preferably a crosslinking group selected from the above crosslinking group group T. The substituent further having a crosslinking group is preferably an alkyl group or an aromatic hydrocarbon group.

[0076] <Charge Transport Materials> The charge transport material of the present invention refers to a material capable of transporting holes and / or electrons. The polymer having a cross-linking group described later and the charge transporting polymer compound of the present invention are both charge transport materials. In addition, the charge transport material of the present invention is preferably hole transporting, preferably a material that is oxidized by an electron accepting compound and converted to a cation radical. In the present invention, as the charge transporting polymer compound, it is preferably a hole transporting polymer compound, preferably a polymer comprising an arylamine structure as a repeating unit. In this case, charge refers to a usual hole, transporting charge refers to transporting holes, charge transport film refers to a hole transport film, and charge injection layer refers to a hole injection layer.

[0077] [Polymer of the present invention] The polymer according to the embodiment of the present invention is a polymer containing a repeating unit represented by the following formula (1).

[0078] [Chemistry 20]

[0079] (In formula (1), Ar 1 It represents a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the foregoing divalent aromatic hydrocarbon groups and the foregoing divalent aromatic heterocyclic groups are linked directly or via a linking group. Ar 2 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by linking a plurality of groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups. Ar 1 with Ar 2 The ring can be formed via a single bond or a linking group. Ar 1 It may have a substituent. Ar 2 It may have a substituent. Ar 2 It has at least one cross-linking group represented by formula (2) or formula (3).

[0080] [Chemistry 21]

[0081] [Chemistry 22]

[0082] (In formula (2) and formula (3), Ar 3 ~Ar 5 each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent, Ar 6 represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent, R 1 represents a hydrogen atom, or a monovalent alkyl group which may have a substituent, a monovalent alkenyl group which may have a substituent, a monovalent alkynyl group which may have a substituent, a monovalent alkoxy group which may have a substituent, a monovalent aromatic hydrocarbon group, or a monovalent aromatic heterocyclic group which may have a substituent, HA 1 represents an oxygen atom or a sulfur atom, n1 represents an integer from 1 to 5, n2 represents an integer from 0 to 5, n3 represents an integer from 0 to 5, "-*" indicates the position of bonding with formula (1).

[0083] <Polymer comprising a repeating unit represented by formula (1)>

[0084] [Chemistry 23]

[0085] (In formula (1), Ar 1 It represents a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the foregoing divalent aromatic hydrocarbon groups and the foregoing divalent aromatic heterocyclic groups are linked directly or via a linking group. Ar 2 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by linking a plurality of groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups. Ar 1 with Ar 2 The ring can be formed via a single bond or a linking group. Ar 1 It may have a substituent. Ar 2 It may have a substituent. Ar 2 It has at least one cross-linking group represented by formula (2) or formula (3).

[0086] Ar 1 、Ar 2 The substituent that may be present is preferably a substituent selected from the aforementioned substituent group Z.

[0087] (Terminal Group) In this specification, the terminal group refers to the structure of the terminal portion of the polymer formed by the end-capping agent used when terminating the polymerization of the polymer. In the composition of the present invention, the terminal group of the polymer comprising the repeating unit represented by formula (1) is preferably a hydrocarbon group. As the hydrocarbon group, from the viewpoint of charge transportability, it is preferably a hydrocarbon group having 1 or more and 60 or less carbon atoms, more preferably a hydrocarbon group having 1 or more and 40 or less carbon atoms, and further preferably a hydrocarbon group having 1 or more and 30 or less carbon atoms.

[0088] Examples of the hydrocarbon group include: A linear, branched, or cyclic alkyl group having usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, or a dodecyl group; A linear, branched, or cyclic alkenyl group having usually 2 or more and 24 or less, preferably 12 or less carbon atoms, such as a vinyl group; a linear or branched alkynyl group having usually 2 or more and 24 or less, preferably 12 or less carbon atoms, such as an ethynyl group; The aromatic hydrocarbon group, such as a phenyl group and a naphthyl group, usually has 6 or more and 36 or less, preferably 24 or less carbon atoms.

[0089] These hydrocarbon groups may further have a substituent, and the substituent that may be further possessed is preferably an alkyl group or an aromatic hydrocarbon group. When there are multiple substituents that may be further possessed, they may be bonded to each other to form a ring.

[0090] From the viewpoint of charge transportability and durability, the terminal group is preferably an alkyl group or an aromatic hydrocarbon group, more preferably an aromatic hydrocarbon group.

[0091] (Ar 1 ) Ar 1 It represents a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the foregoing divalent aromatic hydrocarbon groups and the foregoing divalent aromatic heterocyclic groups are linked directly or via a linking group; the aromatic hydrocarbon group and the aromatic heterocyclic group may have a substituent. The substituent that may be present is preferably a substituent selected from the aforementioned substituent group Z.

[0092] (Twisted structure) As a repeating unit represented by the aforementioned formula (1), in the case where Ar 1 It is preferred that the main chain structure represented by includes a partial structure represented by the following formula (63) to form a structure in which the main chain is twisted, thereby inhibiting conjugation.

[0093] [Chemistry 24]

[0094] (In formula (63), R 601 is an alkyl group which may have a substituent, Ar 621 is a divalent aromatic hydrocarbon group which may have a substituent, or a divalent aromatic heterocyclic group which may have a substituent, Ring Ar represents an aromatic hydrocarbon structure which may have a substituent, or a divalent aromatic heterocyclic structure which may have a substituent, -* indicates the bonding position with the adjacent atom. ) It should be noted that Ar in the repeating unit of the arylamine structure represented by the above formula (1) 1 In the above formula (63), the left and right sides are irrelevant. That is, the following formula (63') also has the same meaning as the above formula (63).

[0095] [Chemistry 25]

[0096] (Ar 2 ) Ar 2 It represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by linking a plurality of groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups. The aromatic hydrocarbon group and the aromatic heterocyclic group may have a substituent. The substituent that may be present is preferably a substituent selected from the aforementioned substituent group Z. Ar 2 It has at least one cross-linking group represented by formula (2) or formula (3).

[0097] [Chemistry 26]

[0098] [Chemistry 27]

[0099] (In formula (2) and formula (3), Ar 3 ~Ar 5 each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent, Ar 6 represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent, R 1 represents a hydrogen atom, or a monovalent alkyl group which may have a substituent, a monovalent alkenyl group which may have a substituent, a monovalent alkynyl group which may have a substituent, a monovalent alkoxy group which may have a substituent, a monovalent aromatic hydrocarbon group, or a monovalent aromatic heterocyclic group which may have a substituent, HA 1 represents an oxygen atom or a sulfur atom, n1 represents an integer from 1 to 5, n2 represents an integer from 0 to 5, n3 represents an integer from 0 to 5, "-*" indicates the position of bonding with formula (1).

[0100] From the viewpoint of stability, Ar 2 Having HA selected from formula (2) 1 The cross-linking group is an oxygen atom and HA in formula (3) 1 At least one of the group consisting of cross-linking groups consisting of oxygen atoms. In addition, from the viewpoint of crosslinking temperature, Ar is preferably 2 Having Ar selected from formula (2) 3 is a cross-linking group of a benzene ring and Ar in formula (3) 6 At least one of the group consisting of cross-linking groups which is a phenyl group.

[0101] (Ar 3 ~Ar 5 ) Ar 3 ~Ar 5 Each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. 3 ~Ar 5 It preferably has no substituent. The aromatic hydrocarbon ring is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring are preferred. The aromatic heterocycle is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specific examples include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, and a phenanthridine ring. Preferred are pyridine ring, pyrazine ring, pyrimidine ring, imidazole ring, benzothiazole ring, benzoxazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring. More preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring. Most preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, quinoxaline ring, and quinazoline ring. More preferred are a furan ring, a benzofuran ring, a thiophene ring, and a benzothiophene ring. As Ar 3 ~Ar 5 , preferably a benzene ring, a naphthalene ring, or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, and most preferably a benzene ring.

[0102] (Ar 6 ) Ar 6 represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent. 6 It preferably has no substituent. The aromatic hydrocarbon ring is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring are preferred. The aromatic heterocycle is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specific examples include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, and a phenanthridine ring. Preferred are pyridine ring, pyrazine ring, pyrimidine ring, imidazole ring, benzothiazole ring, benzoxazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring. More preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring. Most preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, quinoxaline ring, and quinazoline ring. More preferred are a furan ring, a benzofuran ring, a thiophene ring, and a benzothiophene ring. As Ar 6 , preferably a benzene ring, a naphthalene ring, or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, and most preferably a benzene ring.

[0103] (R 1 ) R 1 R represents a hydrogen atom, a monovalent alkyl group which may have a substituent, a monovalent alkenyl group which may have a substituent, a monovalent alkynyl group which may have a substituent, a monovalent alkoxy group which may have a substituent, a monovalent aromatic hydrocarbon group, or a monovalent aromatic heterocyclic group which may have a substituent. 1 Preferred is a hydrogen atom.

[0104] (HA 1 ) HA 1 Represents an oxygen atom or a sulfur atom. 1 An oxygen atom is preferred.

[0105] (n1) n1 represents an integer of 1 to 5. From the viewpoint of reactivity of the crosslinking group, n1 is preferably an integer of 2 or greater. From the viewpoint of durability, n1 is preferably an integer of 4 or less, and more preferably an integer of 3 or less.

[0106] (n2) n2 represents an integer of 0 to 5. From the viewpoint of solubility, n2 is preferably an integer of 1 or greater, more preferably an integer of 2 or greater. From the viewpoint of durability, n2 is preferably an integer of 4 or less, more preferably an integer of 3 or less.

[0107] (n3) n3 represents an integer of 0 to 5. From the viewpoint of reactivity of the crosslinking group, n3 is preferably an integer of 3 or less, more preferably an integer of 2 or less, further preferably an integer of 1 or less, and most preferably 0.

[0108] <(Ar 3 )n1、(Ar 4 )n2> From the viewpoint of solubility and durability of the compound, (Ar 3 )n1、(Ar 4 )n2 preferably has at least one partial structure selected from the following formulae (72-1) to (72-6).

[0109] [Chemistry 28]

[0110] In each of the above formulas (72-1) to (72-6), * represents a bonding position to an adjacent structure or a hydrogen atom, and at least one of the two *s represents a bonding position to an adjacent structure. In the following description, unless otherwise specified, the definition of * is the same.

[0111] As the formula (72-2), the following formula (72-2-2) is preferable.

[0112] [Chemistry 29]

[0113] As formula (72-2), the following formula (72-2-3) is more preferable.

[0114] [Chemistry 30]

[0115] In addition, from the viewpoint of solubility and durability of the polymer, as (Ar 3 )n1、(Ar 4 )n2 has a preferred partial structure including a partial structure represented by formula (72-1) and a partial structure represented by formula (72-2).

[0116] (Specific examples of the cross-linking group represented by formula (2)) Specific examples of the cross-linking group represented by formula (2) are given below, but the cross-linking group represented by formula (2) is not limited to these.

[0117] [Chemistry 31]

[0118] (“-*” indicates the position of bonding with formula (1))

[0119] (Specific examples of the cross-linking group represented by formula (3)) Specific examples of the cross-linking group represented by formula (3) are given below, but the cross-linking group represented by formula (3) is not limited to these.

[0120] [Chemistry 32]

[0121] [Chemistry 33]

[0122] (“-*” indicates the position of bonding with formula (1))

[0123] Formula (2) or formula (3) is a structure formed by bonding an aryloxy group, heteroaryloxy group, arylthio group or heteroarylthio group such as a phenoxy group to the cyclobutene ring, so the electron donation to the cyclobutene ring is strong. Therefore, it is believed that the activation energy required for the ring-opening reaction of the structure represented by formula (2) or formula (3) is smaller than the activation energy of the ring-opening reaction of the benzocyclobutene and 1,2-dihydrocyclobutene [a] naphthalene currently used, and the cross-linking reaction can be carried out at a lower temperature. Further, by lowering the cross-linking temperature, the energy of the ring-opening and activated state becomes smaller. As a result, it is believed that the side reaction to the portion related to charge transport can be reduced, the hole trap can be reduced, and the driving voltage of the organic electroluminescent element can be reduced. In addition, the polymer of the present invention can carry out the cross-linking reaction at a lower temperature, and its reaction speed is also fast. Therefore, it is believed that when the polymer of the present invention is used in combination with other charge transport materials or electron accepting compounds, the unevenness of the components caused by the cross-linking process can be suppressed, so a layer with excellent charge transport can be obtained, and an organic electroluminescent element with excellent luminescent performance can be obtained.

[0124] <Preferred Ar 2 > From the perspective of excellent charge transport and durability, Ar 2 An aromatic hydrocarbon group is preferred, with a benzene ring (phenyl), a group consisting of 2 to 5 linked benzene rings, or a monovalent group consisting of a fluorene ring (fluorenyl) being more preferred. Fluorenyl is further preferred, and 2-fluorenyl is particularly preferred. These may have a substituent. The substituent is preferably a group selected from the aforementioned substituent group Z.

[0125] As Ar 2The substituents that the aromatic hydrocarbon group and the aromatic heterocyclic group may have are not particularly limited as long as they do not significantly reduce the properties of the present polymer. The substituents are preferably groups selected from the substituent group Z described below, more preferably alkyl, alkoxy, aromatic hydrocarbon, aromatic heterocyclic, and even more preferably alkyl.

[0126] From the perspective of solubility in solvents, Ar 2 A fluorenyl group substituted with an alkyl group having 1 to 24 carbon atoms is preferred, and a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms is particularly preferred. Furthermore, a 9-alkyl-2-fluorenyl group substituted with an alkyl group at the 9-position of the 2-fluorenyl group is preferred, and a 9,9'-dialkyl-2-fluorenyl group disubstituted with an alkyl group is particularly preferred.

[0127] A fluorenyl group in which at least one of the 9-position and the 9'-position is substituted with an alkyl group tends to improve solvent solubility and the durability of the fluorenyl ring. Furthermore, a fluorenyl group in which both the 9-position and the 9'-position are substituted with an alkyl group tends to further improve solvent solubility and the durability of the fluorenyl ring.

[0128] In addition, from the perspective of solubility in solvents, Ar 2 Spirobifluorenyl is also preferred.

[0129] In addition, as a polymer containing a repeating unit represented by the above formula (1), it is preferable that Ar in the repeating unit represented by the above formula (1) is 2 It is a repeating unit of a group represented by the following formula (51), a group represented by the following formula (52), or a group represented by the following formula (53).

[0130] <Group represented by formula (51)>

[0131] [Chemistry 34]

[0132] (In formula (51), * represents the position of bonding to the nitrogen atom of the main chain of formula (1), Ar 53 、Ar 54 Each independently represents a divalent aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have a substituent or aromatic heterocyclic groups which may have a substituent are linked directly or via a linking group, Ar 55 represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group in which a plurality of aromatic hydrocarbon groups or aromatic heterocyclic groups which may have a substituent are linked directly or via a linking group, Ar 56 represents a hydrogen atom or a substituent.)

[0133] Here, each aromatic hydrocarbon group and each aromatic heterocyclic group may have a substituent. The substituent that may be present is preferably a group selected from the aforementioned substituent group Z.

[0134] (Ar 53 ) Ar 53 The group is preferably a group consisting of 1 to 6 divalent aromatic hydrocarbon groups linked together, more preferably a group consisting of 2 to 4 divalent aromatic hydrocarbon groups linked together, more preferably a group consisting of 1 to 4 phenylene rings linked together, and particularly preferably a biphenylene group consisting of two phenylene rings linked together.

[0135] These groups may have a substituent. As a substituent that may have, a group selected from the aforementioned substituent group Z is preferred. Preferably, Ar 53 It has no substituent.

[0136] When these multiple divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are linked, it is preferred that the multiple linked divalent aromatic hydrocarbon groups are non-conjugated. Specifically, it is preferred that the group contain 1,3-phenylene groups or groups having substituents and having a twisted structure due to the steric effect of the substituents. It is more preferred that the group contain multiple unsubstituted 1,3-phenylene groups or groups having unsubstituted 1,3-phenylene groups linked.

[0137] (Ar 54 ) From the perspective of excellent charge transport and durability, Ar 54 Preferably, the group is formed by connecting one or more divalent aromatic hydrocarbon groups, which may be the same or different, and the divalent aromatic hydrocarbon group may have a substituent. When multiple groups are connected, the number of connected groups is preferably 2 to 10, more preferably 6 or less, and particularly preferably 3 or less from the perspective of film stability. Preferred aromatic hydrocarbon structures are benzene rings, naphthalene rings, anthracene rings, and fluorene rings, with benzene rings and fluorene rings being more preferred. As a group formed by connecting multiple groups, a group formed by connecting 1 to 4 phenylene rings or a group formed by connecting a phenylene ring and a fluorene ring is preferred. From the perspective of LUMO expansion, a biphenylene ring formed by connecting two phenylene rings is particularly preferred.

[0138] These groups may have substituents. The substituents that may be present are preferably groups selected from the aforementioned substituent group Z. More preferred substituents are phenyl, naphthyl, and fluorenyl. Furthermore, it is also preferred that the groups have no substituents.

[0139] (Ar 55 ) Ar 55It is an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking a plurality of aromatic hydrocarbon groups or aromatic heterocyclic groups which may have a substituent directly or via a linking group. It is preferably a group formed by linking a plurality of monovalent aromatic hydrocarbon groups or monovalent aromatic hydrocarbon groups.

[0140] These groups may have a substituent, and the substituent that may be present is preferably a group selected from the aforementioned substituent group Z.

[0141] When a plurality of these groups are linked, preferably 2 to 10 groups are linked to form a divalent group, and 2 to 5 groups are linked to form a monovalent group. 51 The same aromatic hydrocarbon groups and aromatic heterocyclic groups.

[0142] As Ar 55 , preferably having a structure represented by any one of the following schemes 2A, 2B, and 2C.

[0143] [Chemistry 35]

[0144] [Chemistry 36]

[0145] [Chemistry 37]

[0146] In the above schemes 2A to 2C, "-*" indicates that 54 Bonding position: When there are multiple "-*", any one of them represents the bonding position with Ar 54 Bonding location. These structures may have a substituent. As the substituent that these structures may have, a group selected from the above-mentioned substituent group Z is preferable.

[0147] (R 31 and R 32 ) R for Schemes 2A and 2B 31 and R 32 Each is independently preferably a linear, branched or cyclic alkyl group which may have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more and 6 or less, more preferably 3 or less, and further preferably a methyl group or an ethyl group.

[0148] R 31 and R 32 They may be the same or different, but from the perspective of being able to evenly distribute the charge around the nitrogen atom and facilitating synthesis, it is preferred that all R 31 and R 32are the same group.

[0149] (Ar d18 ) Ar in Scheme 2B d18 Each is independently an aromatic hydrocarbon group or an aromatic heterocyclic group. d18 It is preferably an aromatic hydrocarbon group, more preferably a phenyl group. These groups may further have a substituent. As the substituent that may be present, a group selected from the aforementioned substituent group Z is preferred.

[0150] From the perspective of LUMO distribution of molecules, as Ar 55 , preferably structures selected from the above a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-18 and e-1 to e-4. Furthermore, from the viewpoint of promoting the expansion of the LUMO of the molecule by having an electron-withdrawing group, preferably structures selected from a-1 to a-4, b-1 to b-9, d-1 to d-12, d-17, d-18 and e-1 to e-4. Furthermore, from the viewpoint of a high triplet energy level and the effect of confining the formed excitons in the light-emitting layer, preferably structures selected from a-1 to a-4, d-1 to d-12, d-17, d-18 and e-1 to e-4. Moreover, from the viewpoint of simple synthesis and excellent stability, d-1, d-10, d-17, d-18 and e-1 are more preferred, and the benzene ring structure of d-1, the fluorene structure of d-6 or the carbazole structure of d-17 are particularly preferred.

[0151] Ar 55 In the case of the fluorene structure represented by d-6, 2-fluorenyl is preferred. Furthermore, the 9 and 9' positions may have a substituent, and the substituent is preferably a group selected from the aforementioned substituent group Z. As the substituent, an alkyl group is particularly preferred.

[0152] (Ar 56 ) Ar 56 Represents a hydrogen atom or a substituent. 56 When it is a substituent, it is not particularly limited, but is preferably an aromatic hydrocarbon group or an aromatic heterocyclic group, and may further have a substituent selected from the substituent group Z.

[0153] Ar 56 When it is a substituent, it is preferably bonded to Ar in formula (51) from the viewpoint of improving durability. 56 From the perspective of ease of synthesis and charge transport, Ar 56 Preferably, it is a hydrogen atom. From the viewpoint of improving durability and charge transport properties, Ar 56An aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent is preferred, and an aromatic hydrocarbon group which may have a substituent is more preferred.

[0154] From the viewpoint of ease of synthesis and charge transport properties, Ar 56 Preferred is a hydrogen atom.

[0155] (Specific examples of the group represented by formula (51)) Specific examples of the group represented by formula (51) are given below, but the group represented by formula (51) is not limited to these.

[0156] [Chemistry 38]

[0157] <Group represented by formula (52)>

[0158] [Chemistry 39]

[0159] (In formula (52), Ar 61 and Ar 62 Each is independently a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have a substituent or aromatic heterocyclic groups which may have a substituent are linked directly or via a linking group, Ar 63 ~Ar 65 are each independently a hydrogen atom or a substituent. * represents the bonding position to the nitrogen atom of the main chain in formula (1).

[0160] The substituents that each aromatic hydrocarbon group may have and the substituents that each aromatic heterocyclic group may have, and Ar when it is a substituent 63 ~Ar 65 It is preferably a group selected from the aforementioned substituent group Z.

[0161] (Ar 63 ~Ar 65 ) Ar 63 ~Ar 65 Each independently with the aforementioned Ar 56 same. Ar 63 ~Ar 64 Preferred is a hydrogen atom.

[0162] (Ar 62 ) Ar 62It is a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have a substituent or aromatic heterocyclic groups which may have a substituent are linked directly or via a linking group. Preferably, it is a group formed by linking a plurality of divalent aromatic hydrocarbon groups which may have a substituent or a divalent aromatic hydrocarbon group which may have a substituent. Here, the substituents which the aromatic hydrocarbon group may have and the substituents which the aromatic heterocyclic group may have are preferably the same as those in the above-mentioned substituent group Z.

[0163] Ar 62 The specific structure and Ar 54 same.

[0164] Ar 62 The specific preferred groups are divalent groups of benzene rings, naphthalene rings, anthracene rings, fluorene rings, or groups formed by connecting multiple groups thereof, more preferably divalent groups of benzene rings, or groups formed by connecting multiple groups thereof, particularly preferably 1,4-phenylene formed by divalent benzene rings connected at the 1,4 positions, 2,7-fluorenylene formed by divalent fluorene rings connected at the 2,7 positions, or groups formed by connecting multiple groups thereof, and most preferably a group containing "1,4-phenylene-2,7-fluorenylene-1,4-phenylene".

[0165] In Ar 62 In these preferred structures, it is preferred that the phenylene group has no substituents other than the connecting position, and Ar is not affected by the steric effect of the substituents. 62 In addition, from the perspective of improving solubility and durability of the fluorene structure, the fluorenylene group preferably has a substituent at the 9,9' position. The substituent is preferably a substituent selected from the aforementioned substituent group Z, and among them, an alkyl group is more preferred.

[0166] (Ar 61 ) Ar 61 For the aforementioned Ar 53 The same groups have the same preferred structures.

[0167] (Specific examples of the group represented by formula (52)) Specific examples of the group represented by formula (52) are given below, but the group represented by formula (52) is not limited to these.

[0168] [Chemistry 40]

[0169] <Group represented by formula (53)>

[0170] [Chemistry 41]

[0171] (In formula (53), * represents the position of bonding to the nitrogen atom of the main chain of formula (1), Ar 71 represents a divalent aromatic hydrocarbon group, Ar 72 and Ar 73 Each independently represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a monovalent group formed by linking two or more groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups directly or via a linking group, and these groups may have a substituent. Ring HA is an aromatic heterocycle containing a nitrogen atom, X 2 、Y 2 Each independently represents a carbon atom or a nitrogen atom, X 2 and Y 2 When at least one of the carbon atoms is a carbon atom, the carbon atom may have a substituent.

[0172] The optional substituent is preferably a group selected from the aforementioned substituent group Z.

[0173] <Ar 71 > Ar 71 For the aforementioned Ar 53 Same group.

[0174] As Ar 71 , particularly preferably a group formed by connecting 2 to 6 benzene rings which may have a substituent, and most preferably a tetraphenylene group formed by connecting 4 benzene rings which may have a substituent.

[0175] In addition, Ar 71 It preferably contains at least one benzene ring linked at the 1- and 3-positions of the non-conjugated portion, and more preferably contains two or more benzene rings.

[0176] Ar 71 In the case of a group in which a plurality of divalent aromatic hydrocarbon groups which may have a substituent are linked, it is preferred that all of the groups be linked by direct bonds from the viewpoint of charge transport properties and durability.

[0177] Therefore, as Ar 71 Preferred structures linking the nitrogen atom of the polymer backbone and the ring HA in formula (53) are shown in Schemes 2-1 and 2-2 below. "-*" indicates the position of bonding to a nitrogen atom of the polymer backbone or the ring HA in formula (53). Either of the two "-*"s may be bonded to a nitrogen atom of the polymer backbone or to the ring HA.

[0178] [Chemistry 42]

[0179] As Ar 71 The substituents that may be present may be any one of the aforementioned substituent group Z or a combination thereof. 71 The preferred range of the substituents that may be present is the same as that of the aforementioned Ar 53 The substituents that may be possessed by the aromatic hydrocarbon group are the same as those in the case of the aromatic hydrocarbon group.

[0180] <X 2 and Y 2 > X 2 and Y 2 Each independently represents a C (carbon) atom or a N (nitrogen) atom. 2 and Y 2 When at least one of them is a C atom, they may have a substituent.

[0181] From the perspective of making LUMO more easily localized near the ring HA, X 2 and Y 2 Both are preferably N atoms.

[0182] As X 2 and Y 2 When at least one of the atoms is a C atom, any one of the aforementioned substituent groups Z or a combination thereof may be used as a substituent. From the viewpoint of charge transport properties, X 2 and Y 2 More preferably, it has no substituent.

[0183] <Ar 72 and Ar 73 > Ar 72 and Ar 73 Each independently represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a monovalent group formed by linking two or more groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups directly or via a linking group. These groups may have a substituent, and the substituents that may be present are preferably groups selected from the aforementioned substituent group Z.

[0184] From the perspective of LUMO distribution of molecules, Ar 72 and Ar 73 Each is preferably independently selected from the structures a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-16, and e-1 to e-4 shown in the aforementioned Schemes 2A to 2C. Furthermore, from the viewpoint of promoting LUMO expansion of the molecule by having an electron-withdrawing group, structures selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-12, and e-1 to e-4 are preferred. Furthermore, from the viewpoint of a high triplet energy level and the effect of confining the formed excitons in the light-emitting layer, structures selected from a-1 to a-4, d-1 to d-12, and e-1 to e-4 are preferred. In order to prevent molecular aggregation, structures selected from d-1 to d-12 and e-1 to e-4 are more preferred. 72 and Ar 73 The structure of d-1 or d-10 is preferred, and the benzene ring structure of d-1 is particularly preferred. Furthermore, these structures may have a substituent.

[0185] (Specific examples of the group represented by formula (53)) Specific examples of the group represented by formula (53) are given below, but the group represented by formula (53) is not limited to these.

[0186] [Chemistry 43]

[0187] (Preferred repeating unit represented by formula (1)) The repeating unit represented by the aforementioned formula (1) is preferably a repeating unit represented by the following formula (1-1), (1-2), (1-3), (1-4), or (1-5).

[0188] <Repeating unit represented by formula (1-1)>

[0189] [Chemistry 44]

[0190] (In formula (1-1), Ar 2 and Ar in the above formula (1) 2 same. X is -C(R 207 )(R 208 )-、-N(R 209 )-or-C(R 211 )(R 212 )-C(R 213 )(R 214 )-. R 201 、R 202 、R 221 and R 222 Each independently represents an alkyl group which may have a substituent. R 207 ~R 209 and R 211 ~R 214Each is independently a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. a and b are each independently an integer of 0-4. c is an integer from 0 to 3. d is an integer from 0 to 4. i and j are each independently an integer of 0-3. Where a×c+b×d+i+j is greater than or equal to 1.)

[0191] (R 201 、R 202 、R 221 、R 222 ) R in the repeating unit represented by the above formula (1-1) 201 、R 202 、R 221 and R 222 Each independently represents an alkyl group which may have a substituent.

[0192] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, it is preferably 1 or more, and preferably 8 or less, more preferably 6 or less, and even more preferably 3 or less. The alkyl group is more preferably a methyl group or an ethyl group.

[0193] R 201 When there are multiple, multiple R 201 Can be the same or different, R 202 When there are multiple, multiple R 202 From the perspective of being able to evenly distribute the charge around the nitrogen atom and facilitating synthesis, all R 201 With R 202 The same groups are preferred.

[0194] R 221 When there are multiple, multiple R 221 Can be the same or different, R 222 When there are multiple, multiple R 222 Can be the same or different. From the perspective of ease of synthesis, all R 221 With R 222 The same groups are preferred.

[0195] (R 207 ~R 209 and R 211 ~R 214 ) R 207 ~R 209 and R 211 ~R 214Each is independently a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.

[0196] The alkyl group is not particularly limited, but in order to tend to improve the solubility of the polymer, the number of carbon atoms is preferably 1 or more, and preferably 24 or less, more preferably 8 or less, and further preferably 6 or less. The alkyl group may have a linear, branched, or cyclic structure.

[0197] Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, a cyclohexyl group, and a dodecyl group.

[0198] The aralkyl group is not particularly limited, but the number of carbon atoms is preferably 5 or more and preferably 60 or less, more preferably 40 or less, in order to tend to improve the solubility of the polymer.

[0199] Specific examples of the aralkyl group include 1,1-dimethyl-1-phenylmethyl, 1,1-di(n-butyl)-1-phenylmethyl, 1,1-di(n-hexyl)-1-phenylmethyl, 1,1-di(n-octyl)-1-phenylmethyl, phenylmethyl, phenylethyl, 3-phenyl-1-propyl, 4-phenyl-1-n-butyl, 1-methyl-1-phenylethyl, 5-phenyl-1-n-propyl, 6-phenyl-1-n-hexyl, 6-naphthyl-1-n-hexyl, 7-phenyl-1-n-heptyl, 8-phenyl-1-n-octyl, and 4-phenylcyclohexyl.

[0200] The aromatic hydrocarbon group is not particularly limited, but the number of carbon atoms is preferably 6 or more and preferably 60 or less, and more preferably 30 or less, in order to tend to improve the solubility of the polymer.

[0201] Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, A monovalent group of a six-membered ring such as a ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, or a condensed two- to five-membered ring, or a group formed by connecting a plurality of these rings, etc.

[0202] From the perspective of improving charge transport and durability, R 207 and R 208 Preferably, it is a methyl group or an aromatic hydrocarbon group, R 207 and R 208 More preferably, it is methyl, R 209 More preferred is phenyl.

[0203] R 201 、R 202 、R 221 、R 222The alkyl group, R 207 ~R 209 and R 211 ~R 214 The alkyl, aralkyl and aromatic hydrocarbon groups may have a substituent. The substituents include the aforementioned R 207 ~R 209 and R 211 ~R 214 The groups are exemplified as preferred groups of alkyl, aralkyl and aromatic hydrocarbon groups.

[0204] From the perspective of low voltage, R 201 、R 202 、R 221 、R 222 The alkyl group, R 207 ~R 209 and R 211 ~R 214 The alkyl group, aralkyl group and aromatic hydrocarbon group most preferably have no substituent.

[0205] (a, b, c, and d) In the repeating unit represented by the above formula (1-1), a and b are each independently an integer of 0 to 4. a+b is preferably 1 or greater, and further, a and b are each preferably an integer of 2 or less, and both a and b are more preferably 1. Here, when b is an integer of 1 or greater, d is also an integer of 1 or greater. Furthermore, when c is an integer of 2 or greater, multiple a's may be the same or different, and when d is an integer of 2 or greater, multiple b's may be the same or different.

[0206] When a+b is 1 or greater, the aromatic rings in the main chain are twisted due to steric hindrance, resulting in excellent solvent solubility of the polymer. Furthermore, a coating film formed by a wet film-forming method and then heat-treated tends to be highly insoluble in solvents. Therefore, when a+b is 1 or greater, when another organic layer (e.g., a light-emitting layer) is formed on the coating film by a wet film-forming method, dissolution of the polymer into the composition for forming the other organic layer containing an organic solvent is suppressed.

[0207] In the repeating unit represented by the above formula (1-1), c is an integer of 0 to 3, and d is an integer of 0 to 4. c and d are each preferably an integer of 2 or less, more preferably c and d are equal, and particularly preferably both c and d are 1 or both c and d are 2.

[0208] When c and d in the repeating unit represented by the above formula (1-1) are both 1 or both c and d are 2 and a and b are both 2 or 1, R 201 With R 202 Most preferably, the bonding is at positions symmetrical to each other.

[0209] Here, R 201 With R202 Bonding at mutually symmetrical positions means that relative to the fluorene ring, carbazole ring or 9,10-dihydrophenanthrene derivative structure in formula (1-1), R 201 With R 202 The bonding positions are symmetrical. In this case, the structure is considered to be the same when the main chain axis is rotated 180 degrees.

[0210] Existence R 221 and R 222 When X is present, each of the carbon atoms of the benzene ring to which X is bonded is preferably present at the 1-position, 3-position, 6-position or 8-position. 221 and / or R 222 , bonded with R 221 and / or R 222 The fused ring and the adjacent benzene ring on the main chain are twisted due to steric hindrance, and the polymer has excellent solubility in solvents. At the same time, the coating film formed by the wet film forming method and heated tends to have excellent insolubility in solvents, so it is preferred.

[0211] (i, j) In the repeating unit represented by the above formula (1-1), i and j are each independently an integer of 0 to 3. i and j are each independently preferably an integer of 0 to 2, more preferably 0 or 1. i and j are preferably the same integer. In order to twist the main chain of the polymer, i and j are preferably 1 or 2, and R is preferably 221 and / or R 222 Bonded to the 1-position and / or 3-position of the benzene ring. From the perspective of ease of synthesis, i and j are preferably 0. It should be noted that the bonding position of the aforementioned benzene ring is the adjacent carbon atom to which X is bonded and R 221 or R 222 The carbon atom that can be bonded is designated as the 1-position, and the carbon atom that will bond to the adjacent structure as the main chain is designated as the 2-position.

[0212] (X) From the viewpoint of high stability during charge transfer, X in the above formula (1-1) is preferably -C(R 207 )(R 208 )-or-N(R 209 )-, more preferably -C(R 207 )(R 208 )-.

[0213] (Preferred repeating unit) The repeating unit represented by the above formula (1-1) is particularly preferably a repeating unit represented by any one of the following formulae (54-1) to (54-7).

[0214] [Chemistry 45]

[0215] [Chemistry 46]

[0216] In the above formula, R 201 and R 202 Same, and R 201 and R 202 The bonds are in mutually symmetrical positions.

[0217] <Preferred Examples of the Repeating Unit Main Chain Represented by Formula (1-1)> The main chain structure other than the nitrogen atom in the above formula (1-1) is not particularly limited, but is preferably the following structure, for example.

[0218] [Chemistry 47]

[0219] [Chemistry 48]

[0220] [Chemistry 49]

[0221] [Chemistry 50]

[0222] [Chemistry 51]

[0223] [Chemistry 52]

[0224] [Chemistry 53]

[0225] [Chemistry 54]

[0226] <Repeating unit represented by formula (1-2)>

[0227] [Chemistry 55]

[0228] (In formula (1-2), Ar 2 and Ar in the above formula (1) 2 same. R 303 and R 306 Each independently represents an alkyl group which may have a substituent. R 304 and R 305Each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. l is 0 or 1. m is 1 or 2. n is 0 or 1. p is 0 or 1. q is 0 or 1.)

[0229] (R 303 、R 306 ) R in the repeating unit represented by the above formula (1-2) 303 and R 306 Each independently represents an alkyl group which may have a substituent.

[0230] Examples of the alkyl group include the group consisting of the group R 201 and R 202 The same alkyl group may have substituents and preferred structures as R 201 and R 202 Same substituents and preferred structures.

[0231] R 303 When there are multiple, multiple R 303 Can be the same or different, R 306 When there are multiple, multiple R 306 Can be the same or different.

[0232] (R 304 、R 305 ) R in the repeating unit represented by the above formula (1-2) 304 and R 305 Each is independently an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent, preferably an alkyl group which may have a substituent. Preferred R 304 With R 305 same.

[0233] The alkyl group is a linear, branched or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more, preferably 24 or less, more preferably 8 or less, and further preferably 6 or less, in order to improve the solubility of the polymer.

[0234] Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, a cyclohexyl group, and a dodecyl group.

[0235] The alkoxy group is not particularly limited, and is composed of an alkoxy group (-OR 10) of R 10 The alkyl group represented may have any structure of linear, branched or cyclic. However, in order to tend to improve the solubility of the polymer, the number of carbon atoms is preferably 1 or more, and preferably 24 or less, and more preferably 12 or less.

[0236] Specific examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, a hexyloxy group, a 1-methylpentyloxy group, and a cyclohexyloxy group.

[0237] The aralkyl group is not particularly limited, but preferably has 5 or more carbon atoms, and preferably has 60 or less carbon atoms, and more preferably has 40 or less carbon atoms, in order to tend to improve the solubility of the polymer.

[0238] Specific examples of the aralkyl group include 1,1-dimethyl-1-phenylmethyl, 1,1-di(n-butyl)-1-phenylmethyl, 1,1-di(n-hexyl)-1-phenylmethyl, 1,1-di(n-octyl)-1-phenylmethyl, phenylmethyl, phenylethyl, 3-phenyl-1-propyl, 4-phenyl-1-n-butyl, 1-methyl-1-phenylethyl, 5-phenyl-1-n-propyl, 6-phenyl-1-n-hexyl, 6-naphthyl-1-n-hexyl, 7-phenyl-1-n-heptyl, 8-phenyl-1-n-octyl, and 4-phenylcyclohexyl.

[0239] R 304 、R 305 The substituents that the alkyl group, alkoxy group and aralkyl group may have include the following: 207 ~R 209 and R 211 ~R 214 The groups are exemplified as preferred groups of alkyl, aralkyl and aromatic hydrocarbon groups.

[0240] From the perspective of low voltage, R 304 、R 305 The alkyl group, alkoxy group and aralkyl group most preferably have no substituent.

[0241] (l, m and n) l represents 0 or 1, and n represents 0 or 1.

[0242] l and n are each independent, and l+n is preferably 1 or more, more preferably 1 or 2, and even more preferably 2. When l+n is within the above range, the solubility of the polymer is improved and the tendency of precipitation from the composition of the present invention containing the polymer can be suppressed.

[0243] m represents 1 or 2, and is preferably 1 because the organic electroluminescent device produced using the composition of the present invention can be driven at a low voltage and there is a tendency for the hole injection ability, transport ability, and durability to be improved.

[0244] (p and q) p represents 0 or 1, and q represents 0 or 1. When l=n=1, p and q are not 0 at the same time. By making p and q not 0 at the same time, there is a tendency to improve the solubility of the polymer and to suppress precipitation from the composition of the present invention containing the polymer. In addition, for the same reasons as a and b above, when p+q is 1 or more, the aromatic ring of the main chain is twisted due to steric hindrance, the polymer has excellent solubility in the solvent, and the coating film formed by the wet film forming method and heated has an excellent tendency to be insoluble in the solvent. Therefore, when p+q is 1 or more, when other organic layers (such as a light-emitting layer) are formed on the coating film by the wet film forming method, the dissolution of the polymer into the composition for forming the other organic layer containing an organic solvent is suppressed.

[0245] <Specific examples of the repeating unit main chain represented by formula (1-2)> The main chain structure other than the nitrogen atom in formula (1-2) is not particularly limited, and examples thereof include the following structures.

[0246] [Chemistry 56]

[0247] [Chemistry 57]

[0248] [Chemistry 58]

[0249] [Chemistry 59]

[0250] [Chemistry 60]

[0251] [Chemistry 61]

[0252] [Chemistry 62]

[0253] [Chemistry 63]

[0254] <Repeating unit represented by formula (1-3)>

[0255] [Chemistry 64]

[0256] (In formula (1-3), Ar 2and Ar in the above formula (1) 2 same. Ar 41 It represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of at least one group selected from the group consisting of the foregoing divalent aromatic hydrocarbon groups and the foregoing divalent aromatic heterocyclic groups are linked directly or via a linking group. R 441 and R 442 Each independently represents an alkyl group which may have a substituent. t is 1 or 2. u is 0 or 1. r and s are each independently an integer of 0-4. Here, r×t+s×u is greater than or equal to 1.)

[0257] (R 441 、R 442 ) R in the repeating unit represented by the above formula (1-3) 441 、R 442 Each is independently an alkyl group which may have a substituent.

[0258] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited. However, in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more, and preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. The alkyl group is further preferably a methyl group or a hexyl group.

[0259] R 441 and R 442 When there are multiple R 441 and R 442 Can be the same or different.

[0260] (r, s, t, and u) In the repeating unit represented by formula (1-3), r and s are each independently an integer of 0 to 4. When t is 2, the multiple r's may be the same or different. r + s is preferably 1 or greater, and further, r and s are each preferably an integer of 2 or less. When r + s is 1 or greater, it is believed that the driving life of the organic electroluminescent element is further increased for the same reasons as a and b in the aforementioned formula (1-1).

[0261] In the repeating unit represented by the above formula (1-3), t is 1 or 2, and u is 0 or 1. t is preferably 1, and u is preferably 1.

[0262] (Ar 41 ) Ar 41It is a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of at least one group selected from the group consisting of the foregoing divalent aromatic hydrocarbon groups and the foregoing divalent aromatic heterocyclic groups are linked directly or via a linking group.

[0263] As Ar 41 The aromatic hydrocarbon group and the aromatic hydrocarbon group in the formula (1) can be exemplified by the following: 1 Furthermore, the aromatic hydrocarbon group and the substituent that the aromatic hydrocarbon group may have are preferably a group selected from the aforementioned substituent group Z, and the substituent that may be further possessed is also preferably the same as the aforementioned substituent group Z.

[0264] <Repeating unit represented by formula (1-4)>

[0265] [Chemistry 65]

[0266] (In formula (1-4), Ar 2 and Ar in the above formula (1) 2 same. R 517 ~R 519 Each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. f, g, and h are each independently an integer of 0-4. e is an integer from 0 to 3. However, when g is an integer greater than or equal to 1, e is an integer greater than or equal to 1. Wherein, f+e×g+h is greater than or equal to 1.)

[0267] (R 517 ~R 519 ) R 517 ~R 519 The aromatic hydrocarbon group and the aromatic heterocyclic group are each independently the same as the aforementioned Ar 2 Furthermore, the substituents that these groups may have are preferably the same as those in the aforementioned substituent group Z.

[0268] R 517 ~R 519 The alkyl and aralkyl groups in the R 207 The same groups as those mentioned in the above, and further as a substituent which may be possessed, are preferably the same as those in the above R 207 Same group.

[0269] R 517~R 519 The alkoxy group in is preferably an alkoxy group exemplified in the aforementioned substituent group Z, and the substituent group that may be possessed is preferably the aforementioned substituent group Z.

[0270] (f, g, h) f, g, and h each independently represent an integer of 0-4. When e is an integer of 2 or greater, a plurality of g's may be the same or different. f+g+h is preferably 1 or greater. f+h is preferably greater than 1, More preferably, f+h is an integer greater than or equal to 1 and f, g, and h are integers less than or equal to 2. More preferably, f+h is an integer greater than or equal to 1 and f and h are integers less than or equal to 1. The most preferred values ​​of f and h are both 1.

[0271] When f and h are both 1, R 517 With R 519 The bonding is preferably at positions symmetrical to each other. In addition, R 517 With R 519 same.

[0272] More preferably, g is 2. When g is 2, the most preferred 518 The bonds are in mutually symmetrical positions. When g is 2, the most preferred number is 2 R 518 same.

[0273] Here, R 517 With R 519 Bonding at mutually symmetrical positions refers to the following bonding positions. However, for the purpose of description, a 180-degree rotation around the main chain is considered to be the same structure.

[0274] [Chemistry 66]

[0275] It should be noted that when the polymer of the present embodiment contains a repeating unit represented by formula (1-1) and a repeating unit represented by formula (1-4), the ratio of the repeating unit represented by formula (1-1) to the repeating unit represented by formula (1-4) (the number of moles of the repeating unit represented by formula (1-4)) / (the number of moles of the repeating unit represented by formula (1-1)) is preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.5 or more, further preferably 0.9 or more, and particularly preferably 1.0 or more. In addition, this ratio is preferably 2.0 or less, more preferably 1.5 or less, and further preferably 1.2 or less.

[0276] In addition, the repeating unit represented by the aforementioned formula (1-4) is preferably a repeating unit represented by the following formula (58).

[0277] [Chemistry 67]

[0278] When the repeating unit is represented by the above formula (58), g = 0 or 2 is preferred. When g = 2, the bonding positions are 2-position and 5-position. When g = 0, that is, there is no R 518 When the steric hindrance caused by g = 2 and the bonding positions are 2 and 5, that is, the steric hindrance is 2 R 518 When the benzene ring is bonded diagonally, R 517 With R 519 Able to bond at mutually symmetrical positions.

[0279] Furthermore, the repeating unit represented by the aforementioned formula (58) is more preferably a repeating unit represented by the following formula (59) wherein e=3.

[0280] [Chemistry 68]

[0281] When the repeating unit is represented by the above formula (59), g = 0 or 2 is preferred. When g = 2, the bonding positions are 2-position and 5-position. When g = 0, that is, there is no R 518 When the steric hindrance caused by g = 2 and the bonding positions are 2 and 5, that is, the steric hindrance is 2 R 518 When the benzene ring is bonded diagonally, R 517 With R 519 Able to bond at mutually symmetrical positions.

[0282] <Specific examples of the repeating unit main chain represented by formula (1-4)> The main chain structure of the repeating unit represented by formula (1-4) is not particularly limited, and examples thereof include the following structures.

[0283] [Chemistry 69]

[0284] <Repeating Unit Represented by Formula (1-5)> The polymer having the aforementioned arylamine structure as a repeating unit preferably further has a structure represented by the following formula (1-5) as a repeating unit.

[0285] [Chemistry 70]

[0286] (In formula (1-5), Ar 2 and Ar in the above formula (1)2 same. n60 is an integer from 1 to 5.)

[0287] (n60) n60 represents an integer of 1 to 5, preferably an integer of 1 to 4, and more preferably an integer of 1 to 3.

[0288] <Structure that hinders conjugation torsion> When the functional material used in the composition of the present invention is a polymer having a repeating unit represented by the aforementioned formula (1), the repeating unit represented by the aforementioned formula (1) is more preferably a repeating unit represented by the aforementioned formula (1-1), (1-2), (1-3), or (1-4). In addition, the partial structure represented by the aforementioned formula (63) is preferably a partial structure represented by the following formula (61) or the following formula (61'). Therefore, as the repeating unit represented by the aforementioned formula (1), it is further preferred to be a repeating unit represented by the aforementioned formula (1-1) containing a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure, a repeating unit represented by the aforementioned formula (1-2) containing a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure, a repeating unit represented by the aforementioned formula (1-3) containing a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure, or a repeating unit represented by the aforementioned formula (1-4) containing a partial structure represented by the following formula (61) or the following formula (61') as the main chain structure.

[0289] [Chemistry 71]

[0290] (In formula (61) and formula (61'), R 601 R in formula (1-1) 201 or R 202 , R in formula (1-2) 303 、R 304 、R 305 , or R 406 , R in formula (1-3) 441 or R 442 , R in formula (1-4) 517 、R 518 or R 519 , -* indicates the bonding position with the adjacent atoms. When formula (61) is a partial structure of formula (1-1) or a partial structure of formula (1-2), ring B may be a part of a condensed ring. When formula (61') is a partial structure of formula (1-1) or a partial structure of formula (1-2), ring B may be a part of a condensed ring. The partial structures represented by formula (61) and formula (61') except R 601 In addition, in the case of a partial structure of the formula (1-1), ring A and ring B may have R 201 or R 202 , when it is a partial structure of formula (1-2), it may have R 303 、R 304 、R 305 or R 306 , when it is a partial structure of formula (1-3), it may have R 441 or R 442 , when it is a partial structure of formula (1-4), it may also have R 517 、R 518 or R 519 . )

[0291] <Repeating Unit Represented by Formula (1-1-1)> As the repeating unit represented by the aforementioned formula (1), a repeating unit represented by the aforementioned formula (1-1) containing a partial structure represented by the aforementioned formula (61) or the aforementioned formula (61') as a main chain structure, that is, a repeating unit represented by the following formula (1-1-1) is particularly preferred. That is, the repeating unit represented by the aforementioned formula (1-1) is preferably a repeating unit represented by the following formula (1-1-1).

[0292] [Chemistry 72]

[0293] (In formula (1-1-1), Ar 2 , X, R 201 、R 202 、R 221 、R 222 , a, b, c, d and Ar in the above formula (1-1) 2 , X, R 201 、R 202 、R 221 、R 222 , a, b, c, d are the same. a1, a2, b1, b2, i1, i2, j1, and j2 each independently represent 0 or 1. Among them, a, b, c, d, a1, a2, b1, b2, i1, i2, j1, and j2 satisfy any one of the following conditions (1) and (2). Condition (1) At least one of a1, a2, and a is an integer greater than or equal to 1, at least one of b1, b2, and b is an integer greater than or equal to 1, c is an integer greater than or equal to 1, and d is an integer greater than or equal to 1. When c is 1, at least one of a1 or a2 is 1, and when d is 1, at least one of b1 or b2 is 1. Condition (2) At least one of i1, i2, j1, and j2 is 1. Ring A1 may have R at a specific position. 201 divalent benzene ring. Ring A2 may have R 201 A divalent group formed by connecting c-1 benzene rings, wherein when c is 1, it refers to a monocyclic divalent benzene ring. Ring A3 refers to a divalent condensed ring formed by further bonding a biphenyl structure to X. Ring A4 may have R 202 A divalent group formed by connecting d-1 benzene rings, wherein when d is 1, it refers to a monocyclic divalent benzene ring. Ring A5 may have R at a specific position 202 divalent benzene ring.)

[0294] Here, a in formula (1-1) is an integer greater than or equal to 1, which has the same meaning as at least one of a1, a2, and a in formula (1-1-1), and b in formula (1-1) is an integer greater than or equal to 1, which has the same meaning as at least one of b1, b2, and b in formula (1-1-1).

[0295] As shown below, Formula (1-1-1) contains the aforementioned Formula (61) or the aforementioned Formula (61') as a partial structure. When at least one of a1, a2, and a is an integer greater than or equal to 1, When at least one of a1 or a2 is 1 and c is an integer greater than or equal to 2, ring A1 and ring A2 include the aforementioned formula (61) or the aforementioned formula (61') as a partial structure; when c is 1, ring A1 and ring A3 include the aforementioned formula (61) or the aforementioned formula (61') as a partial structure. When a is 1, ring A2 and ring A1, or ring A2 and ring A3 contain the aforementioned formula (61) or the aforementioned formula (61') as a partial structure. Similarly, it can be seen that when at least one of b1, b2, and b is an integer greater than or equal to 1, the aforementioned formula (61) or the aforementioned formula (61') is also included as a partial structure. In addition, it can be seen that when at least one of i1, i2, j1 and j2 is 1, When one or both of i1 and i2 are 1, the bond of ring A3 is R 221The ring of and the benzene ring of ring A2 form formula (61') as a partial structure, When one or both of j1 and j2 are 1, the bond of ring A3 is R 222 The ring of forms the formula (61) with the benzene ring of ring A4 as a partial structure. That is, it was found that ring A3 and ring A2, or ring A3 and ring A4, had a twisted structure. Therefore, since Formula (1-1-1) includes a structure in which the aromatic ring of the main chain is twisted, it is a twisted structure that inhibits conjugation and is therefore preferred.

[0296] <Polymer Molecular Weight> The molecular weight of the polymer contained in the composition of the present invention is described below.

[0297] The weight average molecular weight (Mw) of the polymer having the above-mentioned arylamine structure as a repeating unit is generally 1,000,000 or less, preferably 500,000 or less, more preferably 100,000 or less, further preferably 70,000 or less, and particularly preferably 50,000 or less. Furthermore, the weight average molecular weight is generally 5,000 or more, preferably 10,000 or more, further preferably 12,000 or more, and particularly preferably 15,000 or more.

[0298] When the weight-average molecular weight of the polymer having the above-mentioned arylamine structure as a repeating unit is below the aforementioned upper limit, solubility in solvents can be achieved, and there is a tendency for excellent film-forming properties. Furthermore, when the weight-average molecular weight of the polymer is above the aforementioned lower limit, decreases in the polymer's glass transition temperature, melting point, and vaporization temperature may be suppressed, thereby improving heat resistance. Furthermore, the coating film after the crosslinking reaction may be sufficiently insoluble in organic solvents.

[0299] The number average molecular weight (Mn) of the polymer having the above-mentioned arylamine structure as a repeating unit is generally 750,000 or less, preferably 250,000 or less, more preferably 100,000 or less, and particularly preferably 50,000 or less. Furthermore, the number average molecular weight is generally 2,000 or more, preferably 4,000 or more, more preferably 6,000 or more, and even more preferably 8,000 or more.

[0300] Furthermore, the dispersity (Mw / Mn) of the polymer having the above-mentioned arylamine structure as a repeating unit is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. It should be noted that the lower the dispersity value, the better, so the lower limit is ideally 1. If the dispersity of the polymer is below the above upper limit, purification is easy, and solubility in solvents and charge transport performance are good.

[0301] Typically, the weight-average molecular weight and number-average molecular weight of a polymer are determined by SEC (size exclusion chromatography). In SEC, higher molecular weight components have shorter dissolution times, while lower molecular weight components have longer dissolution times. Using a calibration curve calculated from the dissolution time of polystyrene (standard sample) of known molecular weight, the dissolution time of the sample is converted into molecular weight to calculate the weight-average molecular weight and number-average molecular weight.

[0302] <Content of the Repeating Unit Represented by Formula (1)> The content of the repeating unit represented by formula (1) in the polymer is not particularly limited. In 100 mol% of all the repeating units in the polymer, the repeating unit represented by formula (1) is usually contained in an amount of 10 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and further preferably 50 mol% or more.

[0303] The repeating units of the polymer may be composed solely of the repeating units represented by formula (1), but may also contain repeating units different from the repeating units represented by formula (1) for the purpose of balancing the various properties when used as an organic electroluminescent element. In this case, the content of the repeating units represented by formula (1) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

[0304] <Repeating unit represented by formula (50-2)> The polymer including the arylamine structure of the present invention as a repeating unit may further include a structure represented by the following formula (50-2) in the main chain.

[0305] [Chemistry 73]

[0306] (In formula (50-2), R 81 、R 83 Each independently represents a hydrogen atom, an alkyl group, an aromatic hydrocarbon group or an aromatic heterocyclic group. 81 、R 83 When there are multiple, they can be the same or different. 80 Indicates an integer from 1 to 5.)

[0307] R 81 、R 83 When the alkyl group is a linear, branched, or cyclic alkyl group, the alkyl group may have any number of carbon atoms. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more, 8 or less, more preferably 6 or less, and even more preferably 3 or less, in order to maintain the solubility of the polymer. The alkyl group is more preferably a methyl group or an ethyl group.

[0308] R 81 、R 83When it is an aromatic hydrocarbon group or an aromatic heterocyclic group, it is preferably a structure described in the above "Definition".

[0309] R 81 、R 83 It may have a substituent, and the substituent is preferably a substituent selected from the aforementioned substituent group Z or a crosslinking group.

[0310] From the perspective of polymer durability and charge transport properties, p 80 It is preferably an integer of 3 or less, more preferably an integer of 2 or less, and most preferably 1.

[0311] By including the structure represented by formula (50-2), the conjugation of the polymer main chain is cut, and the S1 energy level and T1 energy level of the polymer are improved. When a composition containing this polymer is used for the hole transport layer of an organic electroluminescent element, it is believed that it is less likely to deactivate the excitons of the light-emitting layer, and the luminous efficiency becomes higher, which is preferred.

[0312] (Preferred repeating unit of polymer) Here, in the repeating units represented by various formulas, the specific structure is sometimes referred to as a "repeating unit". The specific structure refers to a structure obtained by substituting each specific structure or numerical value into all symbols in the general formula. That is, the polymer represented by formula (1) may include only one repeating unit among the repeating units represented by the aforementioned formula (1-1), (1-2), (1-3), (1-4) or (1-5), or may include more than two repeating units. When more than two repeating units are included, these more than two repeating units may be repeating units contained in the same aforementioned general formula, or may be repeating units contained in different general formulas. From the viewpoint of charge transportability and durability, the polymer having an arylamine structure as a repeating unit is further preferably a polymer containing only one or two specific repeating units represented by these various formulas and not containing other repeating units.

[0313] In addition, it is preferred that Ar present in the repeating unit of the polymer represented by formula (1) 1 ~Ar 6 、Ar 41 、R 201 、R 202 、R 221 、R 222 、R 207 ~R 209 、R 211 ~R 214 、R 301 、R 304 ~R 306 、R 441 、R 442 and R 517 ~R519 None of them has a substituent. It should be noted that the polymer represented by formula (1) may contain all Ar 1 ~Ar 6 、Ar 41 、R 201 、R 202 、R 221 、R 222 、R 207 ~R 209 、R 211 ~R 214 、R 301 、R 304 ~R 306 、R 441 、R 442 and R 517 ~R 519 In the present specification, when the polymer represented by formula (1) contains a part of the aforementioned groups, the groups that do not exist are regarded as having no substituent.

[0314] <Specific example> Specific examples of the aforementioned polymer are shown below, but the aforementioned polymer is not limited thereto. Note that the numbers in the chemical formula represent the molar ratio of the repeating units. These polymers may be any of random copolymers, alternating copolymers, block copolymers, graft copolymers, and the order of monomer arrangement is not limited.

[0315] [Chemistry 74]

[0316] [Chemistry 75]

[0317] <Polymer Production Method> The method for producing the polymer of the present invention is not particularly limited and may be any. For example, it may include: a polymerization method based on Suzuki reaction, a polymerization method based on Grignard reaction, a polymerization method based on Yamamoto reaction, a polymerization method based on Ullmann reaction, a polymerization method based on Buchwald-Hartwig reaction, etc. In addition, it may be produced by the same manufacturing method as the manufacturing method of the polymer described in International Publication No. 2019 / 177175, International Publication No. 2020 / 171190, and International Publication No. 2021 / 125011.

[0318] In the case of the polymerization method based on the Ullmann reaction and the polymerization method based on the Buchwald-Hartwig reaction, for example, a polymer containing a repeating unit represented by the aforementioned formula (1-1) is synthesized by reacting a dihalogenated aryl group (Z represents a halogen atom such as I, Br, Cl, or F) represented by the following formula (2a) with a primary aminoaryl group represented by the following formula (2b).

[0319] [Chemistry 76]

[0320] (In the above reaction formula, Ar 2 、R 201 、R 202 , X, a to d have the same meanings as those in the aforementioned formula (1-1).

[0321] In addition, in the case of a polymerization method based on the Ullmann reaction and a polymerization method based on the Buchwald-Hartwig reaction, for example, a polymer containing a repeating unit represented by the formula (1-2) is synthesized by reacting a dihalogenated aryl group represented by the formula (3a) (Z represents a halogen atom such as I, Br, Cl, F, etc.) with a primary aminoaryl group represented by the formula (3b).

[0322] [Chemistry 77]

[0323] (In the above reaction formula, Ar 2 、R 303 ~R 306 , n, m, l, p, q have the same meanings as those in the aforementioned formula (1-2).

[0324] It should be noted that, in the above-mentioned polymerization method, the reaction to form an N-aryl bond is usually carried out in the presence of a base such as potassium carbonate, sodium tert-butoxide, or triethylamine. Alternatively, the reaction may be carried out in the presence of a transition metal catalyst such as a copper or palladium complex.

[0325] <Applications of polymers> The polymer of the present invention is not particularly limited, but due to its excellent electrochemical stability, it is conceivable that elements comprising a layer formed using the polymer will be applied to flat panel displays (e.g., for OA computers, wall-mounted TVs), car display elements, mobile phone displays, light sources that effectively utilize the characteristics of surface emitters (e.g., light sources for copiers, liquid crystal displays, backlight sources for measuring instruments), display panels, and indicator lights.

[0326] [Composition of the present invention] The composition of the embodiment of the present invention is preferably a composition comprising a polymer containing a repeating unit represented by formula (1) and an electron-accepting compound, and the electron-accepting compound is preferably an electron-accepting compound represented by the following formula (81). Hereinafter, the electron-accepting compound represented by the following formula (81) may be referred to as the "electron-accepting compound of the present invention."

[0327] [Electron-accepting compound] In order to improve the hole injectability from anode to hole injection layer or hole transport layer or in order to improve the charge transportability in hole injection layer or hole transport layer, the charge transport material contained in hole injection layer or hole transport layer preferably includes a cation radical site. In order to make charge transport material carry out cation radicalization, electron accepting compound is used when hole injection layer or hole transport layer is formed. As the parent core skeleton of electron accepting compound, owing to having high stability by tetraaryl borate ion as an anion having an ionic valence of 1 described later and the ionic compound consisting of counter cation, it is preferred.

[0328] (Cation Radicalization of Charge Transport Materials) The cation radicalization of the charge transport material proceeds as follows. When a compound having an amine structure is used as a charge transport material, when a tetraarylborate with diaryliodonium as a counter cation is used as an electron accepting compound, then when the hole injection layer or the hole transport layer is formed, the counter cation can be changed from diaryliodonium to ammonium cation as shown in the following formula.

[0329] [Chemistry 78]

[0330] (e.g., Ar, Ar 1’ ~Ar 4’ Each is independently an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by connecting a plurality of structures selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent.

[0331] Since the ammonium cation generated in the above reaction has a half-occupied molecular orbital (SOMO) capable of accepting electrons, the tetraarylborate having the ammonium ion as a counter cation is an electron-accepting compound.

[0332] In the present invention, a compound composed of a cation of the charge transport material and a tetraarylborate ion as an anion is referred to as a charge transport ionic compound. Details will be described later.

[0333] As described later, the hole injection layer and / or hole transport layer of the organic electroluminescent element of the present invention is preferably obtained by wet film formation of the charge transport film-forming composition of the present invention. The charge transport film-forming composition of the present invention is preferably a composition obtained by dissolving or dispersing the electron-accepting compound having a tetraarylborate ion structure described later and the charge transport material described later in an organic solvent. Furthermore, the charge transport layer of the organic electroluminescent element of the present invention preferably contains a charge transporting ionic compound having a tetraarylborate ion structure as an anion and a cation of the charge transport material of the present invention as a counter cation.

[0334] (Cross-linking reaction product) When the charge transport material of the present invention has a crosslinking group, the crosslinking reaction product with the electron-accepting compound having the crosslinking group includes the following crosslinking reaction products. A compound in which electron-accepting compounds are cross-linked. A compound formed by cross-linking an electron-accepting compound and a charge-transporting material. A compound formed by cross-linking an electron-accepting compound with the tetraarylboric acid ion of the present invention. The compound of the present invention is a compound in which tetraarylborate ions are cross-linked. The compound of the present invention is a cross-linked compound of a tetraarylborate ion and a charge transport material.

[0335] Here, the “tetraarylborate ion in the present invention” includes the following cases: the case where it exists as an electron-accepting compound of an ionic compound composed of a tetraarylborate ion and a counter cation described later, and the case where it exists as a charge-transporting ionic compound composed of a tetraarylborate ion and a cation of a charge-transporting material described later.

[0336] As long as the cross-linking reaction can proceed, the two cross-linking groups that undergo the cross-linking reaction may be the same cross-linking group or different cross-linking groups.

[0337] (Preferred electron-accepting compound) The electron-accepting compound is preferably an ionic compound composed of a tetraaryl borate ion and a counter cation, and more preferably an electron-accepting ionic compound composed of a counter anion and a counter cation as a non-coordinating anion represented by the following formula (81). The following formula (81) has a tetraaryl borate ion of the formula (82) described later as an anion. It should be noted that the electron-accepting compound of the present invention is sometimes referred to as an electron-accepting ionic compound.

[0338] [Chemistry 79]

[0339] (In formula (81), 5 R 81 , 5 Rs 82 , 5 Rs 83 , 5 Rs 84 Each is independent and R 81 ~R 84 Each is independently a hydrogen atom, a deuterium atom, a halogen atom (I atom, Br atom, Cl atom, F atom), an aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 50 carbon atoms which may have a substituent, a fluorine-substituted alkyl group having 1 to 12 carbon atoms, or a crosslinking group. Ph 1 、Ph 2 、Ph 3 、Ph 4 are symbols representing individual benzene rings. X + represents the counter cation. Wherein, formula (81) has at least 2 cross-linking groups.

[0340] The electron-accepting compound represented by the aforementioned formula (81) has at least two crosslinking groups. The crosslinking groups are preferably present in the anion portion of the electron-accepting compound represented by the aforementioned formula (81), that is, in the formula (82) described later as a tetraarylborate ion.

[0341] <Tetraarylborate Ion> As the mother core skeleton of the above-mentioned electron-accepting compound, an ionic compound composed of a tetraarylborate ion as an anion with an ionic valence of 1 and a counter cation in which the boron atom is substituted with four aromatic hydrocarbon rings which may have substituents or an aromatic heterocycle which may have substituents is preferred because of its high stability.

[0342] The tetraarylborate ion is an anion of the aforementioned formula (81) represented by the following formula (82).

[0343] [Chemistry 80]

[0344] (In formula (82), R 81 ~R 84 Each of them is related to R in formula (81) 81 ~R 84 same. Ph 1 ~Ph 4 Each of them is related to Ph in formula (81) 1 ~Ph 4 Same as , refers to the symbol of 4 benzene rings. )

[0345] R 81 ~R84 The number of carbon atoms of the aromatic hydrocarbon group used is preferably 6 to 50. As the aromatic hydrocarbon structure, a monocyclic ring or a two- to six-membered condensed ring and a structure formed by connecting 2 to 8 of them are preferred. Specific examples of the aromatic hydrocarbon group include: benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzopyrene ring, A single monovalent group of a 1,2-diphenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, a fluorene ring, a biphenyl structure, a terphenyl structure or a quaterphenyl structure and a monovalent group formed by connecting 2 to 8 of them.

[0346] R 81 ~R 84 The number of carbon atoms of the aromatic heterocyclic group used in the present invention is preferably 3 to 50. The aromatic heterocyclic structure is preferably a monocyclic ring or a two- to six-membered condensed ring or a structure in which 2 to 8 of these rings are linked together. Specific examples of the aromatic heterocyclic group include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a phenanthridine ring, a quinazoline ring, a quinazolinone ring, or an azulene ring, and monovalent groups formed by linking 2 to 8 of these rings. Furthermore, the aromatic heterocyclic group herein may contain at least one of these individual structures, and the linked structure may include an aromatic hydrocarbon structure. When an aromatic hydrocarbon structure is included, the structure may be a structure in which 2 to 8 aromatic heterocycles and aromatic hydrocarbon rings are connected together. Here, as the aromatic hydrocarbon ring, the aforementioned R 81 ~R 84 The individual structures of the aromatic hydrocarbon rings used in the invention.

[0347] Among them, from the perspective of excellent stability and heat resistance, more preferred are monovalent groups of a benzene ring, a naphthalene ring, a fluorene ring, a pyridine ring, or a carbazole ring, or monovalent groups such as biphenyl groups formed by linking 2 to 5 of these groups. Particularly preferred are monovalent groups of a benzene ring or groups formed by linking 2 to 5 benzene rings, specifically phenyl, biphenyl, and terphenyl groups.

[0348] The number of aromatic hydrocarbon groups and aromatic heterocyclic groups contained in a monovalent group formed by linking a plurality of structures selected from aromatic hydrocarbon groups which may have substituents and aromatic heterocyclic groups which may have substituents is preferably 2 or more and 8 or less, more preferably 4 or less, and even more preferably 3 or less. In particular, when the aromatic hydrocarbon group is a biphenyl group, a terphenyl group, or a quaterphenyl group, it is regarded as a structure in which two phenyl groups are linked together, a structure in which three phenyl groups are linked together, or a structure in which four phenyl groups are linked together, respectively.

[0349] As R 81 ~R 84 The substituent that may be present is preferably a group selected from the aforementioned substituent group Z or the crosslinking group group T described later.

[0350] From the perspective of improving the stability of anions and thus enhancing the stabilization effect of cations, R 81 ~R 84 Preferably, it is a fluorine atom or a fluorine-substituted alkyl group. In addition, the number of fluorine atoms or fluorine-substituted alkyl groups is preferably 2 or more, more preferably 3 or more, and most preferably 4.

[0351] As R 81 ~R 84 The fluorine-substituted alkyl group used is preferably a linear or branched alkyl group having 1 to 12 carbon atoms and substituted with a fluorine atom, more preferably a perfluoroalkyl group, further preferably a linear or branched perfluoroalkyl group having 1 to 5 carbon atoms, particularly preferably a linear or branched perfluoroalkyl group having 1 to 3 carbon atoms, and most preferably a perfluoromethyl group. This is because the charge injection layer of the crosslinked reaction product containing the electron-accepting compound having a crosslinking group or the coating film stacked thereon becomes stable. The fluorine-substituted alkyl group is preferably bonded to the para position of the boron atom.

[0352] From the viewpoint of further increasing the stability of the anion and further improving the cation stabilization effect, the tetraaryl borate ion is preferably *-Ph in the aforementioned formula (81). 1 -(R 81 )5. *-Ph 2 -(R 82 )5. *-Ph 3 -(R 83 )5. *-Ph 4 -(R 84 )5, (* represents the position of bonding with boron B of formula (81)) at least one of them is a group represented by the following formula (84) having 4 fluorine atoms. Based on the aspect of improving the stability of the anion, it is further preferred that at least 2 of them are the same group represented by formula (84). Based on the aspect of further improving the stability of the anion, it is most preferred that at least 3 of them are the same group represented by formula (84).

[0353] [Chemistry 81]

[0354] (In formula (84), * represents the position of bonding with boron B in formula (81), F4 represents substitution with four fluorine atoms, R 85 represents an aromatic hydrocarbon group which may have a substituent and / or a cross-linking group, or a cross-linking group.)

[0355] Can be used in R85 The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 40. As the aromatic hydrocarbon structure, a monocyclic ring or a two- to six-membered condensed ring and a structure formed by connecting 2 to 5 of them are preferred. Specifically, there can be mentioned: a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, The crosslinking group that the aromatic hydrocarbon group may have is preferably a crosslinking group selected from the crosslinking group group T described below.

[0356] Can be used in R 85 The crosslinking group is preferably a crosslinking group selected from the crosslinking group group T described later. The aromatic hydrocarbon group and the substituent which the aromatic hydrocarbon group may have but is not a crosslinking group are preferably a group selected from the substituent group Z. Among them, an aromatic hydrocarbon group is preferred from the viewpoint of stability, and an alkyl group is preferred from the viewpoint of solubility.

[0357] <Crosslinking Group T> The crosslinking group is not limited, and examples thereof include a group containing an alkenyl group, a group containing a conjugated diene structure, a group containing an alkynyl group, a group containing an oxirane structure, a group containing an oxetane structure, a group containing an aziridine structure, an azide group, a group containing a maleic anhydride structure, a group containing an alkenyl group bonded to an aromatic ring, and a cyclobutene ring fused to an aromatic ring. Specific examples of preferred crosslinking groups are preferably represented by any of the following formulas (X1) to (X17) in the crosslinking group group T below, and more preferably by any of the following formulas (X1) to (X3). That is, the electron-accepting compound represented by the aforementioned formula (81) preferably has at least one cross-linking group selected from the following cross-linking group group T of formulas (X1) to (X17), and more preferably has at least one cross-linking group selected from formulas (X1) to (X3).

[0358] [Chemistry 82]

[0359] (In formulae (X1) to (X17), Q represents a direct bond or a linking group. “*” indicates the bonding position. R in formula (X3), formula (X4), formula (X5) and formula (X9) 110 represents a hydrogen atom or an alkyl group which may have a substituent. In formulae (X1) to (X3), the benzene ring and the naphthalene ring may have a substituent. Furthermore, substituents may bond to each other to form a ring. In formula (X1) and formula (X2), the cyclobutene ring may have a substituent.

[0360] (Q) When Q is a linking group, the linking group is not particularly limited, but is preferably an alkylene group, a divalent oxygen atom, or a divalent aromatic hydrocarbon group which may have a substituent. The alkylene group generally has 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms. The divalent aromatic hydrocarbon group usually has 6 or more carbon atoms, and usually has 36 or less carbon atoms, preferably 30 or less carbon atoms, and more preferably 24 or less carbon atoms. The structure of the aromatic hydrocarbon ring is preferably a benzene ring, and the substituents it may have may be selected from the aforementioned substituent group Z.

[0361] R 110 The alkyl group represented by is a linear, branched or cyclic structure, and has 1 or more carbon atoms, preferably 24 or less, more preferably 12 or less, and further preferably 8 or less.

[0362] As the benzene ring and naphthalene ring of formula (X1) to (X3) and R of formula (X3), formula (X4), (X5), and (X9) 110 The substituent that may be present is preferably an alkyl group, an aromatic hydrocarbon group, an alkoxy group, or an aralkyl group. The alkyl group as a substituent has a linear, branched or cyclic structure and preferably has 24 or less carbon atoms, more preferably 12 or less carbon atoms, further preferably 8 or less carbon atoms, and preferably 1 or more carbon atoms. The number of carbon atoms in the aromatic hydrocarbon group as a substituent is preferably 24 or less, more preferably 18 or less, further preferably 12 or less, and preferably 6 or more. The aromatic hydrocarbon group may further have the aforementioned alkyl group as a substituent. The number of carbon atoms in the alkoxy group as a substituent is preferably 24 or less, more preferably 12 or less, further preferably 8 or less, and preferably 1 or more. The number of carbon atoms in the aralkyl group as a substituent is preferably 30 or less, more preferably 24 or less, even more preferably 14 or less, and preferably 7 or more. The alkylene group contained in the aralkyl group is preferably a linear or branched structure. The aryl group contained in the aralkyl group may further have the aforementioned alkyl group as a substituent. The cyclobutene ring of formula (X1) or (X2) may have a substituent preferably being an alkyl group. The alkyl group serving as the substituent is a linear, branched, or cyclic structure, and preferably has 24 or fewer carbon atoms, more preferably 12 or fewer, further preferably 8 or fewer, and preferably 1 or more carbon atoms.

[0363] As the crosslinking group, a crosslinking group represented by either formula (X1) or formula (X2) is preferred because the crosslinking reaction proceeds only by heat, the polarity is low, and the effect on charge transport is small.

[0364] As shown in the following formula, the crosslinking group represented by formula (X1) opens the cyclobutene ring due to heat, and the groups after the ring opening bond with each other to form a crosslinked structure. It should be noted that the description of the linking group Q in formulas (X1) to (X3) is omitted below.

[0365] [Chemistry 83]

[0366] As shown in the following formula, the crosslinking group represented by formula (X2) opens the cyclobutene ring due to heat, and the groups after the ring opening are bonded to each other to form a crosslinked structure.

[0367] [Chemistry 84]

[0368] The crosslinking group represented by either formula (X1) or formula (X2) opens the cyclobutene ring due to heat, and the opened group reacts with a double bond when there is a double bond nearby to form a crosslinked structure. The following shows an example in which a crosslinked structure is formed by a ring-opened group of a crosslinking group represented by formula (X1) and a crosslinking group represented by formula (X3) having a double bond site.

[0369] [Chemistry 85]

[0370] As a group containing a double bond that can react with a cross-linking group represented by any one of formula (X1) and formula (X2), in addition to the cross-linking group represented by formula (X3), there can be mentioned a cross-linking group represented by any one of formulas (X4), (X5), (X11), (X14), (X15), (X16), and (X17). When these groups containing a double bond are used as the cross-linking group in the electron-accepting compound, it is preferred that the hole injection layer and / or the hole transport layer formed by the hole transport compound contain a cross-linking group represented by any one of formula (X1) and formula (X2). The possibility of forming a cross-linked structure is increased.

[0371] As the crosslinking group, a crosslinking group represented by any of the radically polymerizable formulae (X3), (X4), and (X5) is preferred because it has low polarity and is less likely to interfere with charge transport.

[0372] As the crosslinking group, a crosslinking group represented by formula (X6) is preferred from the viewpoint of improving electron accepting property. It should be noted that when the crosslinking group represented by formula (X6) is used, a crosslinking reaction as described below proceeds.

[0373] [Chemistry 86]

[0374] From the perspective of high reactivity, a crosslinking group represented by either formula (X7) or (X8) is preferred. It should be noted that when a crosslinking group represented by formula (X7) and a crosslinking group represented by formula (X8) are used, a crosslinking reaction as described below is performed.

[0375] [Chemistry 87]

[0376] As the crosslinking group, a crosslinking group represented by any of the cationically polymerizable formulas (X9), (X10), and (X11) is preferred because of its high reactivity.

[0377] <Ionic Compound Containing Tetraarylborate Ion> Tetraarylborate ions are used as the electron-accepting ionic compound containing tetraarylborate ions.

[0378] (Counter cation) The counter cation is preferably an iodonium cation, a sulfonium cation, a carbonium ion, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation, or a ferrocenium cation having a transition metal, more preferably an iodonium cation, a sulfonium cation, a carbonium ion, or an ammonium cation, and particularly preferably an iodonium cation.

[0379] As the iodonium cation, a structure represented by the following formula (4) is preferred, and the same further preferred structure applies.

[0380] Specific examples of the iodonium cation include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, 4-tert-butoxyphenylphenyliodonium cation, 4-methoxyphenylphenyliodonium cation, and 4-isopropylphenyl-4-methylphenyliodonium cation.

[0381] Specific examples of the sulfonium cation include triphenylsulfonium cation, 4-hydroxyphenyldiphenylsulfonium cation, 4-cyclohexylphenyldiphenylsulfonium cation, 4-methylsulfonylphenyldiphenylsulfonium cation, (4-tert-butoxyphenyl)diphenylsulfonium cation, bis(4-tert-butoxyphenyl)phenylsulfonium cation, and 4-cyclohexylsulfonylphenyldiphenylsulfonium cation.

[0382] Specifically, preferred examples of the carbocation include trisubstituted carbocations such as triphenylcarbocation, tri(methylphenyl)carbocation, and tri(dimethylphenyl)carbocation.

[0383] As the ammonium cation, specifically, preferred are trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, tributylammonium cation, and tri(n-butyl)ammonium cation; N,N-dialkylanilammonium cations such as N,N-diethylanilammonium cation and N,N-2,4,6-pentamethylanilammonium cation; and dialkylammonium cations such as di(isopropyl)ammonium cation and dicyclohexylammonium cation.

[0384] Specifically, preferred examples of the phosphonium cation include tetraarylphosphonium cations such as tetraphenylphosphonium cation, tetra(methylphenyl)phosphonium cation, and tetra(dimethylphenyl)phosphonium cation; and tetraalkylphosphonium cations such as tetrabutylphosphonium cation and tetrapropylphosphonium cation.

[0385] Among these, from the viewpoint of the film stability of the compound, iodonium cations, carbonium ions, and sulfonium cations are preferred, and iodonium cations are more preferred.

[0386] (X + : iodonium cation) X as the counter cation in the aforementioned formula (81) + An iodonium cation having the structure of the following formula (83) is preferred.

[0387] [Chemistry 88]

[0388] In formula (83), Ar 81 、Ar 82 Each independently represents an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, more preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, and most preferably a phenyl group. The substituent group that may be present is a group selected from the aforementioned substituent group Z, with an alkyl group being most preferred. Preferred examples of the aromatic hydrocarbon group include phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthrenyl, triphenylene, and naphthylphenyl. From the perspective of compound stability, phenyl is most preferred.

[0389] (Molecular weight) The molecular weight of the electron-accepting compound of the present invention is usually 900 or more, preferably 1000 or more, more preferably 1200 or more, and is usually 10000 or less, preferably 5000 or less, more preferably 3000 or less. If the molecular weight is too small, the delocalization of positive and negative charges is insufficient, and thus the electron-accepting ability may decrease. If the molecular weight is too large, charge transport may be hindered.

[0390] (specific example) Specific examples of the electron-accepting compound represented by formula (81) are given below, but the present invention is not limited to these.

[0391] [Chemistry 89]

[0392] [Chemistry 90]

[0393] [Chemistry 91]

[0394] <Content of the polymer of the present invention> In the composition ratio of the solid components of the composition of the present invention, from the perspective of reducing the injection barrier in the charge transport layer, the content of the polymer of the present invention is preferably 10% by weight or more, more preferably 25% by weight or more, and even more preferably 30% by weight or more. On the other hand, from the perspective of maintaining charge transport properties in the charge transport layer, the content of the polymer of the present invention in the composition of the present invention is preferably 99% by weight or less, more preferably 90% by weight or less, and even more preferably 80% by weight or less in the composition ratio of the solid components of the composition.

[0395] <Composition Ratio / Content of Polymer and Electron-Accepting Compound in Composition> In the composition of the present invention, relative to the total amount of the polymer of the present invention and the electron accepting compound of the present invention, the content of the polymer of the present invention is preferably 99 weight % or less, more preferably 97 weight % or less, and further preferably 95 weight % or less. In addition, it is preferably 50 weight % or more, more preferably 70 weight % or more, and further preferably 80 weight % or more. It is believed that by within these ranges, the film formed using the composition of the present invention is fully cross-linked without melting, and can be directly wet-coated into a film on the film formed using the composition of the present invention, and in the case where the film formed using the composition of the present invention is used as a charge injection film, the injection barrier to the charge transport layer is reduced and the charge transport property is excellent, the stability during charge transport is improved, and the durability of the element comprising the film formed using the composition of the present invention is improved.

[0396] [Composition] The composition of the present invention may further contain a solvent, a polymerization initiator, additives and the like.

[0397] <Solvent> The composition of the present invention, except polymer of the present invention and electron accepting compound of the present invention, also preferably contains solvent.Particularly when using composition of the present invention to form charge transport film by wet film forming method, preferably adopt the state that polymer of the present invention and electron accepting compound of the present invention are dissolved using solvent.

[0398] As the solvent contained in the composition of the present invention, as long as it is a solvent that can dissolve the polymer of the present invention and the electron-accepting compound of the present invention at the same time, its type is not particularly limited. Here, the solvent that dissolves the polymer of the present invention and the electron-accepting compound of the present invention refers to a solvent that preferably dissolves more than 0.005 weight %, more preferably dissolves more than 0.5 weight %, and further preferably dissolves more than 1 weight % of the polymer of the present invention. In addition, it is a solvent that preferably dissolves more than 0.001 weight %, more preferably dissolves more than 0.1 weight %, and further preferably dissolves more than 0.2 weight % of the aforementioned electron-accepting compound. In addition, it is a solvent that preferably dissolves more than 0.005 weight %, more preferably dissolves more than 0.5 weight %, and further preferably dissolves more than 1 weight % of the aforementioned charge transporting polymer compound.

[0399] Preferred solvents include, for example, aromatic hydrocarbon solvents, ether solvents, and ester solvents. Specific examples of the aromatic hydrocarbon solvent include toluene, xylene, mesitylene, tetralin, and cyclohexylbenzene. Examples of the ether solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole. Examples of the ester solvent include aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; and aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate. These may be used alone or in any combination and ratio of two or more.

[0400] As solvents that can be used other than the above-mentioned ether solvents and ester solvents, for example, amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide, dimethyl sulfoxide, etc. can be mentioned. Any one of these can be used alone, or two or more can be used in any combination and ratio. In addition, one or two or more of these solvents can be used in combination with one or two or more of the above-mentioned ether solvents and ester solvents. In particular, since aromatic hydrocarbon solvents such as benzene, toluene, and xylene have low ability to dissolve electron-accepting compounds and free carriers (cationic radicals), it is preferably used in combination with ether solvents and ester solvents.

[0401] When a solvent is used, the concentration of the solvent relative to the composition of the present invention is preferably 10% by weight or more, more preferably 30% by weight or more, and even more preferably 50% by weight or more. Furthermore, the concentration of the solvent relative to the composition is preferably 99.999% by weight or less, more preferably 99.99% by weight or less, and even more preferably 99.9% by weight or less. It should be noted that when two or more solvents are mixed, the total amount of these solvents should be within this range.

[0402] It should be noted that, when the composition of the present invention is used for organic electroluminescent element, because organic electroluminescent element is to be formed by the layer stacking of multiple organic compounds, therefore require each layer to be uniform layer.When using wet film forming method to form layer, when there is moisture in the solution (composition) used for thin film formation, then can sneak into moisture in the coating and damage the uniformity of film, therefore preferably the moisture content in the solution is as little as possible.In addition, usually organic electroluminescent element mostly uses negative electrode etc. because of moisture and the material of remarkable deterioration, therefore from the viewpoint of element deterioration, it is not preferably there is moisture.

[0403] Specifically, the amount of water contained in the composition of the present invention is preferably 1% by weight or less, more preferably 0.1% by weight or less, and more preferably 0.05% by weight or less. Examples of methods for reducing the water content in the composition include nitrogen sealing, use of a desiccant, prior dehydration of the solvent, and use of a solvent with low solubility in water. Among these, use of a solvent with low solubility in water is preferred from the viewpoint of preventing the solution coating from absorbing moisture from the atmosphere and turning white during the coating step. In the case of use for film formation by a wet film-forming method, the composition of the present invention preferably contains a solvent with low solubility in water, specifically a solvent with a solubility in water of 1% by weight or less, preferably 0.1% by weight or less, at a concentration of 10% by weight or more, preferably 30% by weight or more, and particularly 50% by weight or more, relative to the entire composition.

[0404] <Charge Transport Film Composition> In the case where the electron-accepting compound having a cross-linking group is the aforementioned electron-accepting ionic compound, it is preferably used as a composition containing the electron-accepting ionic compound and the aforementioned polymer of formula (1) (hereinafter, sometimes appropriately referred to as "charge transport film composition (A)"), or a composition containing a charge transport ionic compound composed of a cationic radical containing a polymer described later and a counter anion as part of the electron-accepting ionic compound (hereinafter, sometimes appropriately referred to as "charge transport film composition (B)"). For convenience, the description here is divided into a charge transport membrane composition (A) and a charge transport membrane composition (B), but the charge transport membrane composition also includes the following composition: a composition containing the aforementioned electron-accepting ionic compound, the polymer described later, and a charge transport ionic compound composed of a cationic radical of the polymer described later and a counter anion that is part of the aforementioned electron-accepting ionic compound.

[0405] It should be noted that the charge transport film compositions (A) and (B) are compositions that can be widely used as charge transport materials (charge transport material compositions). However, they are typically formed into films and used as hole injection layers and / or hole transport layers, that is, as "charge transport films" that transport holes as electric charges. Therefore, they are specifically referred to as "charge transport film compositions" in this specification.

[0406] <Charge Transport Film Composition (A)> The charge transport film composition (A) comprises the aforementioned polymer, the aforementioned electron-accepting compound having a crosslinking group, and a solvent. The aforementioned polymer may be contained alone or in combination of two or more.

[0407] <Method for Preparing Charge Transport Film Composition (A)> The charge transport film composition (A) is prepared by mixing at least the electron accepting compound of the present invention and the polymer of the present invention. In this case, the charge transport film composition (A) contains a solvent, and preferably the electron accepting compound of the present invention and the polymer of the present invention are dissolved in the solvent and mixed.

[0408] The content of the aforementioned electron accepting compound of the present invention in the charge transfer film composition (A) is measured relative to the value of the aforementioned polymer of the present invention, usually 0.1 weight % or more, preferably 1 weight % or more, in addition usually 100 weight % or less, preferably 40 weight % or less. If the content of the electron accepting compound is above the above lower limit, it is possible to fully generate free carriers (cationic radicals of the aforementioned polymer of the present invention) and preferably, if it is below the above upper limit, it is possible to ensure sufficient charge transfer energy and preferably. When using two or more electron accepting compounds, the content of their total is included in the above range. The same is true for charge transporting compounds.

[0409] <Charge Transport Film Composition (B)> As described above, the charge transport film composition (B) is a composition containing a charge transport ionic compound composed of the cation radical of the aforementioned polymer of the present invention and the counter anion of the aforementioned electron accepting ionic compound. The cation radical of the polymer of the present invention, which is a cation of the charge-transporting ionic compound, is a chemical species obtained by removing one electron from the electrically neutral compound shown in the polymer of the present invention. The cationic radical of the polymer of the present invention is a polymer having a structure represented by the following formula (110).

[0410] [Chemistry 92]

[0411] (In the above formula (110), Ar 1 、Ar 2 Each of them is the same as Ar in the above formula (1) 1 、Ar 2 same)

[0412] <Charge-Transporting Ionic Compounds> The charge-transporting ionic compound is a compound in which the cation radical of the aforementioned polymer of the present invention is ionically bonded to a counter anion that is a part of the electron-accepting ionic compound. The charge-transporting ionic compound can be obtained by mixing the electron-accepting ionic compound with the polymer of the present invention, and is easily soluble in various solvents. Specifically, it can be obtained by the method described below in the "Method for Preparing the Charge Transport Film Composition (B)".

[0413] <Method for Preparing Charge Transport Film Composition (B)> The charge-transporting ionic compound (B) is preferably prepared by dissolving an electron-accepting ionic compound and the polymer of the present invention in a solvent and mixing them. In this solution, the polymer of the present invention is oxidized by the electron-accepting ionic compound to form a cation radical, thereby generating an ionic compound of the counter anion of the electron-accepting ionic compound and the cation radical of the polymer of the present invention, i.e., the charge-transporting ionic compound.

[0414] In this case, by mixing the polymer of the present invention and the electron-accepting ionic compound in a solution, the probability of the electron-accepting ionic compound being present near the nitrogen atom of the amine structure, which is a site easily oxidized in the polymer of the present invention, increases. The amine in the polymer of the present invention is oxidized by the electron-accepting ionic compound to form a cation radical. This is because an ionic compound of the counter anion of the electron-accepting ionic compound and the cation radical of the polymer of the present invention is easily generated. At this time, from the perspective of promoting the above reaction, it is preferable to heat the solution.

[0415] In addition, it is also preferred to heat the mixture of the electron accepting ionic compound and the aforementioned polymer of the present invention to prepare. The mixture is preferably a film obtained by applying a solution in a solvent to which the electron accepting ionic compound and the aforementioned polymer of the present invention are dissolved, drying the solution and forming the film. By heating the mixture, the electron accepting ionic compound and the aforementioned polymer of the present invention diffuse into each other in the mixture, and the probability of the electron accepting compound being present near the nitrogen atom of the amine at the easily oxidized site of the aforementioned polymer of the present invention increases, because the ionic compound of the cationic free radical of the counter anion of the electron accepting ionic compound and the aforementioned polymer of the present invention is easily generated. The heating temperature at this time is preferably a temperature at which the cross-linking group of the composition does not undergo a cross-linking reaction, but even if it is a temperature at which the cross-linking group undergoes a cross-linking reaction, the cross-linking reaction also occurs while diffusing, and therefore the electron accepting ionic compound can be formed without problem.

[0416] The charge transport film composition (B) may contain one or more of the aforementioned charge transport ionic compounds. It is preferred to contain one or two charge transport ionic compounds, and more preferably, to contain one. This is because charge transport ionic compounds have low ionization potential variation and excellent hole transport properties. A composition containing one or two charge-transporting ionic compounds alone refers to a composition prepared using only two or three electron-accepting ionic compounds and the aforementioned polymer of the present invention in total, and is a composition prepared using at least one electron-accepting ionic compound and at least one aforementioned polymer of the present invention.

[0417] The charge transport film composition (B) preferably contains a charge transport compound in addition to the charge transport ionic compound. When preparing the charge transport film composition (B), the content of the polymer of the present invention as a charge amount relative to the charge transport ionic compound is preferably 10% by weight or more, more preferably 20% by weight or more, and more preferably 30% by weight or more, and is preferably 10,000% by weight or less, and more preferably 1,000% by weight or less.

[0418] Regarding the charge transport film formed by the charge transport film composition (B), a high hole injection / transport ability is exerted by the migration of positive charges from the charge transport ionic compound to the nearby neutral charge transport compound. Therefore, the weight ratio of the charge transport ionic compound to the neutral polymer of the present invention is preferably about 1:100 to 100:1, and more preferably about 1:20 to 20:1.

[0419] <Relationship between Charge Transport Film Compositions (A) and (B)> The charge transport film formed from the charge transport film composition (A) has excellent heat resistance and high hole injection / transport capabilities. The reasons for achieving such excellent properties are described below. The charge transport film composition (A) contains the aforementioned electron accepting compound and charge transporting compound. The cation in the electron accepting ionic compound has a hypervalent central atom, and its positive charge is widely delocalized, so it has high electron acceptance. Thus, electron migration occurs from the charge transport compound to the cation of the electron accepting ionic compound, generating a charge transporting ionic compound composed of a cation radical and a counter anion of the charge transporting compound. The cation radical of the charge transporting compound becomes a charge carrier, so the conductivity of the charge transport film can be improved. That is, it is believed that when the charge transport film composition (A) is prepared, at least a portion of the charge transporting ionic compound composed of a cation radical of the charge transporting compound and a counter anion of the electron accepting ionic compound is generated. For example, when electron migration occurs from the charge-transporting compound represented by formula (7) below to the electron-accepting compound represented by formula (6), a charge-transporting ionic compound represented by formula (9) is generated, which is composed of a cation radical of the charge-transporting compound and a counter anion.

[0420] [Chemistry 93]

[0421] [Preparation of composition] The composition of the present invention can be prepared by mixing the polymer of the present invention, the electron-accepting compound of the present invention, and preferably further mixing a functional material containing the aforementioned electron-accepting compound with a solvent and heating for a certain period of time to dissolve or disperse it. In order to uniformly dissolve or disperse the functional material in the solvent, the heating temperature is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, for example, 100-115°C. In addition, the heating time is preferably 30 minutes or longer, more preferably 45 minutes or longer, and even more preferably 60 minutes or longer, for example, 60-180 minutes.

[0422] The heated composition is filtered using a membrane filter or depth filter to remove coarse particles before use. Considering the application of the composition by ejection from the nozzle of an inkjet head, the pore size of the filter is preferably 0.5 μm or less, more preferably 0.2 μm or less, and even more preferably 0.1 μm or less.

[0423] [Film Formation Method Using Composition] When forming a film using the composition of the present invention, the composition of the present invention is preferably a solution containing a solvent, and the composition of the present invention is preferably subjected to wet film formation. Wet film formation involves applying a solvent-containing composition onto a substrate and drying to remove the solvent to form a film. The coating method is not particularly limited, and examples thereof include spin coating, dip coating, die coating, rod coating, bar coating, roller coating, spray coating, capillary coating, inkjet printing, screen printing, gravure printing, and flexographic printing.

[0424] The solvent is typically removed by drying by heating. Examples of heating methods used in the heating step include a clean oven, a hot plate, and infrared heating. Infrared heating can be achieved with a halogen heater, a ceramic-coated halogen heater, or a ceramic heater. Infrared heating directly applies thermal energy to the substrate or film, allowing for faster drying compared to heating in an oven or hot plate. This minimizes the effects of atmospheric gases (moisture, oxygen) and fine dust, improving productivity and making it preferable.

[0425] The heating temperature is usually 80° C. or higher, preferably 100° C. or higher, more preferably 150° C. or higher. The heating temperature is usually 300° C. or lower, preferably 280° C. or lower, more preferably 260° C. or lower. The heating time is usually 10 seconds or longer, preferably 60 seconds or longer, more preferably 90 seconds or longer, and usually 120 minutes or shorter, preferably 60 minutes or shorter, more preferably 30 minutes or shorter. In addition, vacuum drying is also preferably performed before heat drying. The thickness of the organic layer formed by the wet film-forming method is usually 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more. In addition, the thickness is usually 1000 nm or less, preferably 500 nm or less, more preferably 300 nm or less.

[0426] [Organic electroluminescent element] The film using the composition of the present invention and the film formed using the composition of the present invention can be suitably used as a charge transport layer, and the charge transport layer is particularly preferably used as a charge transport film of an organic electroluminescent element. As one embodiment, the organic electroluminescent element of the present invention has an anode and a cathode on a substrate and an organic layer between the anode and the cathode, wherein the organic layer contains a cross-linked reaction product of a polymer containing a repeating unit represented by formula (1) and an electron-accepting compound. The electron-accepting compound is preferably an electron-accepting compound represented by formula (81). The polymer containing a repeating unit represented by formula (1) and the electron-accepting compound represented by formula (81) and their preferred embodiments are as described above.

[0427] The aforementioned organic layer contains a repeating unit represented by formula (1), and the repeating units represented by formula (1) preferably contain a cross-linked product having a cross-linked structure bonded via at least one of the structures represented by the following formulas (2-1), (2-2), (2-3), (2-4), (2-5), (3-1), and (3-2). In addition, the cross-linked product more preferably has a group obtained by removing at least one hydrogen atom from an electron-accepting compound represented by formula (81). The repeating unit represented by formula (1) and the electron-accepting compound represented by formula (81) and their preferred embodiments are as described above.

[0428] [Chemistry 94]

[0429] [Chemistry 95]

[0430] [Chemistry 96]

[0431] (In formula (2-1), formula (2-2), formula (2-3), formula (2-4), formula (2-5), formula (3-1), and formula (3-2), Ar 3 ~Ar 5 、Ar 6 、R 1 , HA 1 , n1, n2, n3 and Ar in formula (2) and formula (3)3 ~Ar 5 、Ar 6 、R 1 , HA 1 , n1, n2, and n3 are the same. R 110 represents a hydrogen atom or an alkyl group which may have a substituent, "-*" each represents a bonding position to formula (1).

[0432] As an example of the structure of the organic electroluminescent element of the present invention, Figure 1 Schematic diagram (cross section) of a structural example of the organic electroluminescent element 8 is shown in FIG. Figure 1 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents a light emitting layer, 6 represents an electron transport layer, and 7 represents a cathode.

[0433] <Substrate> Substrate 1 serves as the support for the organic electroluminescent element and is typically made of a quartz or glass plate, a metal plate or foil, or a plastic film or sheet. Glass plates are preferred, as are plates made of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone. Because the organic electroluminescent element is less susceptible to degradation by external air, the substrate is preferably made of a material with high gas barrier properties. Therefore, particularly when using a synthetic resin substrate with low gas barrier properties, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to enhance the gas barrier properties.

[0434] <Anode> The anode 2 has the function of injecting holes into the layer on the light-emitting layer 5 side.

[0435] The anode 2 is usually composed of metals such as aluminum, gold, silver, nickel, palladium, and platinum; metal oxides such as indium and / or tin oxides; metal halides such as copper iodide; carbon black, and conductive polymers such as poly(3-methylthiophene), polypyrrole, and polyaniline.

[0436] The anode 2 is usually formed by a dry method such as sputtering or vacuum evaporation. In addition, when using metal particles such as silver, copper iodide, carbon black, conductive metal oxide particles, conductive polymer powder, etc. to form the anode, it can also be formed by dispersing them in a suitable binder resin solution and applying them on the substrate. In the case of a conductive polymer, the anode can also be formed by directly forming a thin film on the substrate by electrolytic polymerization or by applying the conductive polymer on the substrate (Applied Physics Letters, Vol. 60, p. 2711, 1992).

[0437] The anode 2 is usually a single-layer structure, but may be a laminated structure as appropriate. When the anode 2 is a laminated structure, different conductive materials may be laminated on the first layer of the anode.

[0438] The thickness of the anode 2 can be determined based on the required transparency and material. In particular, when high transparency is required, the thickness is preferably such that the transmittance of visible light is 60% or more, and more preferably such that the transmittance of visible light is 80% or more. The thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, when transparency is not required, the thickness of the anode 2 can be arbitrarily set based on the required strength, etc. In this case, the anode 2 can be the same thickness as the substrate.

[0439] When forming other layers on the surface of the anode 2, it is preferred to pre-treat with ultraviolet light / ozone, oxygen plasma, argon plasma, etc. before film formation to remove impurities on the anode 2 and adjust its ionization potential to improve hole injection properties.

[0440] <Hole Injection Layer> The layer that performs the function of transporting holes from the anode 2 side to the light-emitting layer 5 side is generally referred to as a hole injection and transport layer or a hole transport layer. Furthermore, when there are two or more layers that perform the function of transporting holes from the anode 2 side to the light-emitting layer 5 side, the layer closer to the anode side is sometimes referred to as a hole injection layer 3. Forming a hole injection layer 3 is preferred from the perspective of strengthening the function of transporting holes from the anode 2 side to the light-emitting layer 5 side. When forming the hole injection layer 3, the hole injection layer 3 is generally formed on the anode 2.

[0441] The hole injection layer 3 formed using the composition of the present invention contains a crosslinked reaction product of the carbazole compound of the present invention and the electron-accepting compound of the present invention.

[0442] The method for forming the hole injection layer 3 is not particularly limited, and examples thereof include a vacuum deposition method and a wet film formation method. When forming the layer by a wet film forming method, the composition of the present invention is prepared, applied to the anode 2 by a wet film forming method such as spin coating or dip coating, and dried to form the hole injection layer 3 .

[0443] Particularly preferably, a film formed using a composition comprising the aforementioned carbazole compound of the present invention and the aforementioned electron-accepting compound of the present invention, and a composition comprising the aforementioned carbazole compound of the present invention and the aforementioned electron-accepting compound of the present invention are used. The film thickness of the hole injection layer 3 formed in this manner is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[0444] The hole injection layer may be formed by vacuum deposition or wet film formation, but is preferably formed by wet film formation because of its excellent film-forming properties. Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, and amide solvents.

[0445] Examples of the ether solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

[0446] Examples of the ester solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

[0447] Examples of the aromatic hydrocarbon solvent include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene.

[0448] Examples of the amide solvent include N,N-dimethylformamide and N,N-dimethylacetamide.

[0449] In addition, dimethyl sulfoxide and the like can also be used.

[0450] The hole injection layer 3 is formed by a wet film-forming method generally by preparing a hole injection layer-forming composition, applying the composition onto a layer corresponding to the lower layer of the hole injection layer 3 (generally the anode 2 ), and drying the composition.

[0451] The hole injection layer 3 is usually formed and then dried by heating, drying under reduced pressure, or the like.

[0452] <Hole Transport Layer> The hole transport layer 4 is a layer that transports holes from the anode 2 to the light-emitting layer 5. While the hole transport layer 4 is not an essential layer in the organic electroluminescent element of the present invention, it is preferably formed in order to transport holes from the anode 2 to the light-emitting layer 5. When the hole transport layer 4 is formed, it is typically formed between the anode 2 and the light-emitting layer 5. Furthermore, when the hole injection layer 3 is present, it is formed between the hole injection layer 3 and the light-emitting layer 5.

[0453] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

[0454] The material forming the hole transport layer 4 is preferably a material with high hole transport properties and capable of efficiently transporting injected holes. To this end, it is preferred that the material has a low ionization potential, high transparency to visible light, high hole mobility, excellent stability, and is not prone to the formation of impurities that become traps during manufacturing or use. In addition, in most cases, the hole transport layer 4 is in contact with the light-emitting layer 5, so it is preferred not to quench the light from the light-emitting layer 5 or to not form an exciplex with the light-emitting layer 5, thereby reducing efficiency.

[0455] The material of the hole transport layer 4 may be any material that has been conventionally used as a constituent material of the hole transport layer, and examples thereof include the materials exemplified as the hole transport compound used in the aforementioned hole injection layer 3. Examples thereof include aromatic amine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, condensed-ring polycyclic aromatic derivatives, and metal complexes.

[0456] Examples include polyvinylcarbazole derivatives, polyarylamine derivatives, polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ether sulfone derivatives containing tetraphenylbenzidine, polyarylene vinylene derivatives, polysiloxane derivatives, polythiophene derivatives, and poly(p-phenylene vinylene) derivatives. These may be alternating copolymers, random copolymers, block polymers, or graft copolymers. Furthermore, they may be polymers having branches in the main chain and three or more terminal ends, or so-called dendrimers.

[0457] Among them, polyarylamine derivatives and polyarylene derivatives are preferred. The polyarylamine derivative is preferably a polymer comprising a repeating unit represented by the following formula (I). In particular, a polymer consisting of a repeating unit represented by the following formula (I) is preferred. In this case, in each repeating unit, Ar a ' or Ar b 'It can be different.

[0458] [Chemistry 97]

[0459] (In formula (I), Ar a ' and Ar b ' each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.)

[0460] Examples of the polyarylene derivative include polymers having an arylene group such as an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent in its repeating unit.

[0461] The polyarylene derivative is preferably a polymer having a repeating unit composed of the following formula (II-1) and / or the following formula (II-2).

[0462] [Chemistry 98]

[0463] (In formula (II-1), R a 、R b 、R c and R d Each independently represents an alkyl group, an alkoxy group, a phenylalkyl group, a phenylalkoxy group, a phenyl group, a phenoxy group, an alkylphenyl group, an alkoxyphenyl group, an alkylcarbonyl group, an alkoxycarbonyl group, or a carboxyl group. x11 and x12 each independently represent an integer from 0 to 3. When x11 or x12 is an integer greater than 2, the number of R groups contained in one molecule is a or R b Can be the same or different, adjacent R a or R b They can form a ring with each other.)

[0464] [Chemistry 99]

[0465] (In formula (II-2), R e and R f Each independently of R in the above formula (II-1) a 、R b 、R c or R d x13 and x14 each independently represent an integer from 0 to 3. When x13 or x14 is an integer greater than 2, the number of R e and R f Can be the same or different, adjacent R e or R f L represents an atom or group of atoms constituting a five-membered ring or a six-membered ring.

[0466] Specific examples of L include an oxygen atom, a boron atom which may have a substituent, a nitrogen atom which may have a substituent, a silicon atom which may have a substituent, a phosphorus atom which may have a substituent, a sulfur atom which may have a substituent, a carbon atom which may have a substituent, or a group formed by bonding these.

[0467] Furthermore, the polyarylene derivative preferably has a repeating unit represented by the following formula (III-3) in addition to the repeating unit composed of the above formula (II-1) and / or the above formula (II-2).

[0468] [Chemistry 100]

[0469] (In formula (III-3), Ar c ~Ar i Each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. x15 and x16 each independently represent 0 or 1.

[0470] Specific examples of the above formulae (III-1) to (III-3) and specific examples of the polyarylene derivative include those described in JP-A-2008-98619.

[0471] When the hole transport layer 4 is formed by a wet film formation method, a hole transport layer-forming composition is prepared in the same manner as in the formation of the hole injection layer 3 , and then heated and dried after wet film formation.

[0472] The hole transport layer-forming composition contains, in addition to the aforementioned hole transport compound, a solvent. The solvent used is the same as that used in the hole injection layer-forming composition. Furthermore, the film formation conditions, heating and drying conditions, and the like are the same as those used for forming the hole injection layer 3.

[0473] When the hole transport layer is formed by vacuum deposition, the film formation conditions and the like are the same as those for forming the hole injection layer 3 .

[0474] The hole transport layer 4 may contain various light-emitting materials, electron transport compounds, binder resins, coating improvers, and the like in addition to the hole transport compound described above.

[0475] Alternatively, the hole transport layer 4 may be a layer formed by cross-linking a cross-linking compound. The cross-linking compound is a compound having a cross-linking group and forms a network polymer compound by cross-linking.

[0476] Examples of the crosslinking group include groups derived from cyclic ethers such as oxetane and epoxy compounds; groups derived from unsaturated double bonds such as vinyl, trifluorovinyl, styryl, acrylic, methacryloyl, and styrylaldehyde; and groups derived from benzocyclobutene.

[0477] The crosslinking compound may be any of a monomer, an oligomer, and a polymer. The crosslinking compound may be present in one type or in two or more types in any combination and ratio.

[0478] As the cross-linking compound, a hole-transporting compound having a cross-linking group is preferably used. As hole transport compounds, the compounds exemplified above can be mentioned, and as cross-linking compounds, compounds in which a cross-linking group is bonded to a main chain or a side chain for these hole transport compounds can be mentioned. Particularly preferably, the cross-linking group is bonded to the main chain via a linking group such as an alkylene group. In addition, as a hole transport compound, in particular, a polymer comprising a repeating unit having a cross-linking group is preferred, and preferably a polymer having a repeating unit in which the cross-linking group in the above-mentioned formula (I) or formulas (II-1) to (III-3) is bonded directly or via a linking group.

[0479] In forming the hole transport layer 4 by crosslinking the crosslinkable compound, a hole transport layer-forming composition is generally prepared by dissolving or dispersing the crosslinkable compound in a solvent, and the composition is formed by wet film formation to achieve crosslinking.

[0480] The thickness of the hole transport layer 4 formed in this manner is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 150 nm or less.

[0481] <Luminous Layer> The light-emitting layer 5 is a layer that emits light by being excited by the recombination of holes injected from the anode 2 and electrons injected from the cathode 7 when an electric field is applied between the pair of electrodes. The light-emitting layer 5 is formed between the anode 2 and the cathode 7. If a hole injection layer exists on the anode, the light-emitting layer is formed between the hole injection layer and the cathode. If a hole transport layer exists on the anode, the light-emitting layer is formed between the hole transport layer and the cathode. As described above, the organic electroluminescent device in the present invention preferably contains a suitable light-emitting layer-forming material as the light-emitting layer.

[0482] The thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention. However, a thicker thickness is preferred to reduce the risk of defects in the film, while a thinner thickness is preferred to facilitate a low driving voltage. Therefore, the thickness is preferably 3 nm or greater, more preferably 5 nm or greater, and is generally preferably 200 nm or less, more preferably 100 nm or less.

[0483] The light-emitting layer 5 contains at least a material having a light-emitting property (light-emitting material), and preferably contains one or more host materials.

[0484] <Suitable Materials for Light-Emitting Layer> The light-emitting layer of the present invention comprises a light-emitting material and a charge transport material. The light-emitting material may be a phosphorescent material or a fluorescent material. Preferably, the red and green light-emitting materials are phosphorescent materials, and the blue light-emitting material is a fluorescent material.

[0485] (Phosphorescent materials) Phosphorescent materials are materials that emit light from an excited triplet state. Representative examples include metal complex compounds containing Ir, Pt, Eu, and the like. The material preferably contains a metal complex.

[0486] Among metal complexes, examples of phosphorescent organometallic complexes that emit light via the triplet state include Werner-type complexes or organometallic complex compounds containing a metal selected from Groups 7 to 11 of the long-periodic periodic table (hereinafter, unless otherwise specified, "periodic table" refers to the long-periodic periodic table) as a central metal. Examples of such phosphorescent materials include those described in International Publication Nos. 2014 / 024889, 2015 / 087961, 2016 / 194784, and JP-A-2014-074000. Preferably, the compound is represented by the following formula (201) or the following formula (205), and more preferably, the compound is represented by the following formula (201).

[0487] [Chemistry 101]

[0488] (In formula (201), ring A1 represents an aromatic hydrocarbon structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A2 represents an aromatic heterocyclic structure which may have a substituent. R 101 、R 102 Each independently represents a structure represented by formula (202), and "*" represents a bonding position to ring A1 or ring A2. 101 、R 102 Can be the same or different, in R 101 、R 102 When there are plural of each, they may be the same or different.

[0489] Ar 201 、Ar 203 Each independently represents an aromatic hydrocarbon structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Substituents bonded to ring A1, substituents bonded to ring A2, or substituents bonded to ring A1 and substituents bonded to ring A2 may bond to each other to form a ring.

[0490] B 201 -L 200 -B 202 Indicates an anionic bidentate ligand. B 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may also be a ring-forming atom. 200 Represents a single bond or with B 201 and B 202 Together they form a bidentate ligand. 201 -L 200 -B 202 , they may be the same or different.

[0491] It should be noted that in formulas (201) and (202), i1 and i2 each independently represent an integer from 0 to 12, i3 indicates that it can replace Ar 202 The number of is an integer greater than 0, i4 indicates that it can replace Ar 201 The number of is an integer greater than 0, k1 and k2 each independently represent an integer greater than or equal to 0, with the number of rings that can be substituted for ring A1 and ring A2 being the upper limit. z represents an integer from 1 to 3.)

[0492] (Substituent) Unless otherwise specified, the substituent possessed by the compound represented by formula (201) is preferably a group selected from the following substituent group S.

[0493] <Substituent Group S> The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, further preferably an alkyl group having 1 to 8 carbon atoms, and particularly preferably an alkyl group having 1 to 6 carbon atoms. The alkoxy group is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and still more preferably an alkoxy group having 1 to 6 carbon atoms. The aryloxy group is preferably an aryloxy group having 6 to 20 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, further preferably an aryloxy group having 6 to 12 carbon atoms, and particularly preferably an aryloxy group having 6 carbon atoms. The heteroaryloxy group is preferably a heteroaryloxy group having 3 to 20 carbon atoms, and more preferably a heteroaryloxy group having 3 to 12 carbon atoms. The alkylamino group is preferably an alkylamino group having 1 to 20 carbon atoms, and more preferably an alkylamino group having 1 to 12 carbon atoms. The arylamino group is preferably an arylamino group having 6 to 36 carbon atoms, and more preferably an arylamino group having 6 to 24 carbon atoms. The aralkyl group is preferably an aralkyl group having 7 to 40 carbon atoms, more preferably an aralkyl group having 7 to 18 carbon atoms, and even more preferably an aralkyl group having 7 to 12 carbon atoms. The heteroaralkyl group is preferably a heteroaralkyl group having 7 to 40 carbon atoms, and more preferably a heteroaralkyl group having 7 to 18 carbon atoms. The alkenyl group is preferably an alkenyl group having 2 to 20 carbon atoms, more preferably an alkenyl group having 2 to 12 carbon atoms, further preferably an alkenyl group having 2 to 8 carbon atoms, and particularly preferably an alkenyl group having 2 to 6 carbon atoms. Alkynyl group, preferably an alkynyl group having 2 to 20 carbon atoms, more preferably an alkynyl group having 2 to 12 carbon atoms. The aryl group is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 24 carbon atoms, further preferably an aryl group having 6 to 18 carbon atoms, and particularly preferably an aryl group having 6 to 14 carbon atoms. The heteroaryl group is preferably a heteroaryl group having 3 to 30 carbon atoms, more preferably a heteroaryl group having 3 to 24 carbon atoms, further preferably a heteroaryl group having 3 to 18 carbon atoms, and particularly preferably a heteroaryl group having 3 to 14 carbon atoms. The alkylsilyl group is preferably an alkylsilyl group having 1 to 20 carbon atoms, and more preferably an alkylsilyl group having 1 to 12 carbon atoms. The arylsilyl group is preferably an arylsilyl group having 6 to 20 carbon atoms, and more preferably an arylsilyl group having 6 to 14 carbon atoms. - Alkylcarbonyl group, preferably an alkylcarbonyl group having 2 to 20 carbon atoms. The arylcarbonyl group is preferably an arylcarbonyl group having 7 to 20 carbon atoms.

[0494] One or more hydrogen atoms in the above groups may be substituted by fluorine atoms, or one or more hydrogen atoms may be substituted by deuterium atoms. Unless otherwise specified, an aryl group is an aromatic hydrocarbon ring, and a heteroaryl group is an aromatic heterocycle. · A hydrogen atom, a deuterium atom, a fluorine atom, a cyano group or -SF5.

[0495] Among the above-mentioned substituent group S, preferably, alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, alkylsilyl, arylsilyl, and groups in which one or more hydrogen atoms of these groups are substituted with fluorine atoms, fluorine atoms, cyano or -SF5, More preferably, it is an alkyl group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, a group in which one or more hydrogen atoms of these groups are substituted by a fluorine atom, a fluorine atom, a cyano group or -SF5, More preferably, they are alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, alkylsilyl, and arylsilyl. Particularly preferred are alkyl, arylamino, aralkyl, alkenyl, aryl, and heteroaryl. Most preferred are alkyl, arylamino, aralkyl, aryl, and heteroaryl.

[0496] These substituent groups S may further have a substituent selected from the substituent group S. Preferred, more preferred, further preferred, particularly preferred, and most preferred substituents are the same as those in the substituent group S.

[0497] (Ring A1) Ring A1 represents an aromatic hydrocarbon structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent.

[0498] The aromatic hydrocarbon ring is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring are preferred.

[0499] The aromatic heterocycle is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom, and more preferably a furan ring, a benzofuran ring, a thiophene ring, or a benzothiophene ring. Ring A1 is more preferably a benzene ring, a naphthalene ring, or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, and most preferably a benzene ring.

[0500] (Ring A2) Ring A2 represents an aromatic heterocyclic structure which may have a substituent. The aromatic heterocycle is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specific examples include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, and a phenanthridine ring. Preferred are pyridine ring, pyrazine ring, pyrimidine ring, imidazole ring, benzothiazole ring, benzoxazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring. More preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring. Most preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, quinoxaline ring, and quinazoline ring.

[0501] (Combination of Ring A1 and Ring A2) Preferred combinations of Ring A1 and Ring A2, expressed as (Ring A1-Ring A2), are (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-benzothiazole ring), (benzene ring-imidazole ring), (benzene ring-pyrrole ring), (benzene ring-oxadiazole ring) and (benzene ring-thiophene ring).

[0502] (Substituents of Ring A1 and Ring A2) The substituent that Ring A1 and Ring A2 may have can be arbitrarily selected, but is preferably one or more substituents selected from the aforementioned substituent group S.

[0503] (Ar 201 、Ar 202 、Ar 203 ) Ar 201 、Ar 203 Each independently represents an aromatic hydrocarbon structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent.

[0504] Ar 201 、Ar 202 、Ar 203 When any one of the above is an aromatic hydrocarbon structure which may have a substituent, the aromatic hydrocarbon structure is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an acenaphthene ring, a fluoranthene ring, or a fluorene ring is preferred, a benzene ring, a naphthalene ring, or a fluorene ring is more preferred, and a benzene ring is most preferred.

[0505] Ar 201 、Ar 202When any one of them is a benzene ring which may have a substituent, it is preferred that at least one benzene ring is bonded to the adjacent structure at the ortho position or the meta position, and it is more preferred that at least one benzene ring is bonded to the adjacent structure at the meta position.

[0506] Ar 201 、Ar 202 、Ar 203 When any one of them is a fluorene ring which may have a substituent, the 9-position and 9'-position of the fluorene ring preferably have a substituent or are bonded to an adjacent structure.

[0507] Ar 201 、Ar 202 、Ar 203 When any one of the is an aromatic heterocyclic structure which may have a substituent, the aromatic heterocyclic structure is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom or a sulfur atom as a heteroatom. Specifically, examples include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, a phenanthridine ring, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring. Preferably, the pyridine ring, the pyrimidine ring, the triazine ring, the carbazole ring, the dibenzofuran ring, and the dibenzothiophene ring are used.

[0508] Ar 201 、Ar 202 、Ar 203 When any one of them is a carbazole ring which may have a substituent, it is preferred that the N position of the carbazole ring has a substituent or is bonded to an adjacent structure.

[0509] Ar 202 When it is an aliphatic hydrocarbon structure which may have a substituent, it is an aliphatic hydrocarbon structure having a linear, branched or cyclic structure, and preferably has 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, and even more preferably 1 to 8 carbon atoms.

[0510] (i1, i2, i3, i4, k1, k2) i1 and i2 each independently represent an integer of 0 to 12, preferably an integer of 1 to 12, more preferably an integer of 1 to 8, and further preferably an integer of 1 to 6. Within this range, improvement in solubility or charge transport properties can be expected. i3 preferably represents an integer of 0 to 5, more preferably an integer of 0 to 2, and even more preferably 0 or 1. i4 preferably represents an integer of 0 to 2, and more preferably 0 or 1. k1 and k2 each independently represent an integer of preferably 0 to 3, more preferably an integer of 1 to 3, further preferably 1 or 2, and particularly preferably 1.

[0511] (Ar 201 、Ar 202 、Ar 203 Preferred substituents of Ar 201 、Ar 202 、Ar 203 The substituents that may be present may be arbitrarily selected, but are preferably one or more substituents selected from the aforementioned substituent group S. Preferred groups are also as shown in the aforementioned substituent group S, but are more preferably unsubstituted (hydrogen atom), alkyl, aryl, particularly preferably unsubstituted (hydrogen atom), alkyl, most preferably unsubstituted (hydrogen atom) or tert-butyl, preferably tert-butyl in the presence of Ar 203 When substituted with Ar 203 , in the absence of Ar 203 When substituted with Ar 202 , in the absence of Ar 202 and Ar 203 When substituted with Ar 201 .

[0512] (Preferred embodiment of the compound represented by formula (201)) The compound represented by the above formula (201) is preferably a compound that satisfies any one or more of the following (I) to (IV).

[0513] (I) Phenylene connection formula The structure represented by formula (202) is preferably a structure having a group formed by connecting benzene rings, that is, a benzene ring structure, i1 is an integer from 1 to 6, and at least one of the aforementioned benzene rings is bonded to an adjacent structure at the ortho position or meta position. With such a structure, it is expected that the solubility is improved and the charge transport property is improved.

[0514] (II) (phenylene)-aralkyl (alkyl) Ring A1 or Ring A2 has a structure in which an alkyl group or an aralkyl group is bonded to an aromatic hydrocarbon group or an aromatic heterocyclic group, that is, Ar 201 is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, i1 is an integer from 1 to 6, Ar 202 is an aliphatic hydrocarbon structure, i2 is an integer from 1 to 12, preferably an integer from 3 to 8, Ar 203 A benzene ring structure, i3 is 0 or 1, preferably Ar 201 The aromatic hydrocarbon structure is more preferably a structure in which 1 to 5 benzene rings are connected, and more preferably a structure in which 1 benzene ring is connected. With such a structure, it is expected that the solubility is improved and the charge transport property is improved.

[0515] (III) Dendrites A structure in which a dendron is bonded to ring A1 or ring A2, for example, Ar201 、Ar 202 Benzene ring structure, Ar 203 It is a biphenyl or terphenyl structure, i1 and i2 are integers of 1 to 6, i3 is 2, and j is 2. With such a structure, it is expected that the solubility is improved and the charge transport property is improved.

[0516] (IV)B 201 -L 200 -B 202 By B 201 -L 200 -B 202 The structure represented is preferably a structure represented by the following formula (203) or the following formula (204).

[0517] [Chemistry 102]

[0518] In formula (203), R 211 、R 212 、R 213 Each independently represents a substituent. In formula (204), ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom which may have a substituent. Ring B3 is preferably a pyridine ring.

[0519] (Preferred phosphorescent material) The phosphorescent material represented by the above formula (201) is not particularly limited, but the following materials can be cited as preferred materials.

[0520] [Chemistry 103]

[0521] [Chemistry 104]

[0522] In addition, a phosphorescent material represented by the following formula (205) is also preferred.

[0523] [Chemistry 105]

[0524] [In formula (205), M 2 R represents a metal, and T represents a carbon atom or a nitrogen atom. 92 ~R 95 Each independently represents a substituent. When T is a nitrogen atom, there is no R 94 and R 95 . ]

[0525] In formula (205), as M2 Specific examples include metals selected from Groups 7 to 11 of the periodic table. Among them, preferably, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum or gold is used, and particularly preferably, divalent metals such as platinum and palladium are used.

[0526] In addition, in formula (205), R 92 and R 93 Each independently represents a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, an alkoxy group, an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group.

[0527] Moreover, when T is a carbon atom, R 94 and R 95 Each independently represents the 92 and R 93 In addition, when T is a nitrogen atom, there is no R directly bonded to the T. 94 or R 95 In addition, R 92 ~R 95 It may also have a substituent. As a substituent, it may be the substituent mentioned above. Further, R 92 ~R 95 Any two or more groups in the group may be linked to form a ring.

[0528] (Molecular weight) The molecular weight of the phosphorescent material is preferably 5000 or less, more preferably 4000 or less, and particularly preferably 3000 or less. Furthermore, the molecular weight of the phosphorescent material is preferably 800 or more, more preferably 1000 or more, and even more preferably 1200 or more. It is believed that within this molecular weight range, a light-emitting layer can be obtained in which the phosphorescent material is uniformly mixed with the charge transport material without agglomeration, and thus has high luminous efficiency.

[0529] The phosphorescent material preferably has a large molecular weight because it has a high Tg, melting point, decomposition temperature, and other factors, resulting in excellent heat resistance of the phosphorescent material and the resulting light-emitting layer, and is less likely to experience degradation of film quality due to gas generation, recrystallization, and molecular migration, or an increase in impurity concentration associated with thermal decomposition of the material. On the other hand, the phosphorescent material preferably has a small molecular weight because it facilitates purification of the organic compound.

[0530] (Charge Transport Materials) The charge transport material used in the light-emitting layer is a material having a skeleton with excellent charge transport properties, and is preferably selected from electron transport materials, hole transport materials, and bipolar materials capable of transporting both electrons and holes.

[0531] Specific examples of skeletons having excellent charge transport properties include aromatic structures, aromatic amine structures, triarylamine structures, dibenzofuran structures, naphthalene structures, phenanthrene structures, phthalocyanine structures, porphyrin structures, thiophene structures, benzylphenyl structures, fluorene structures, quinacridone structures, triphenylene structures, carbazole structures, pyrene structures, anthracene structures, phenanthroline structures, quinoline structures, pyridine structures, pyrimidine structures, triazine structures, oxadiazole structures, and imidazole structures.

[0532] As the electron transport material, from the viewpoint of excellent electron transport properties and a relatively stable structure, a compound having a pyridine structure, a pyrimidine structure, or a triazine structure is more preferable, and a compound having a pyrimidine structure or a triazine structure is even more preferable.

[0533] The hole transport material is a compound having a structure with excellent hole transport properties. Among the aforementioned central skeletons with excellent charge transport properties, a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure or a pyrene structure is preferred as a structure with excellent hole transport properties, and a carbazole structure, a dibenzofuran structure or a triarylamine structure is further preferred.

[0534] The charge transport material used in the light-emitting layer preferably has a fused ring structure of three or more rings, and more preferably a compound having two or more fused ring structures of three or more rings or a compound having at least one fused ring of five or more rings. By using these compounds, the rigidity of the molecule is increased, and the effect of suppressing the degree of molecular motion of the thermal response is easily obtained. Furthermore, from the aspects of charge transportability and material durability, the fused rings of three or more rings and the fused rings of five or more rings preferably have aromatic hydrocarbon rings or aromatic heterocycles.

[0535] Specific examples of the fused ring structure having three or more rings include anthracene structure, phenanthrene structure, pyrene structure, The structure of the present invention may be a tetracene structure, a triphenylene structure, a fluorene structure, a benzofluorene structure, an indenofluorene structure, an indolofluorene structure, a carbazole structure, an indenocarbazole structure, an indolocarbazole structure, a dibenzofuran structure, a dibenzothiophene structure, etc. From the viewpoint of charge transport and solubility, at least one structure selected from the group consisting of a phenanthrene structure, a fluorene structure, an indenofluorene structure, a carbazole structure, an indenocarbazole structure, an indolocarbazole structure, a dibenzofuran structure, and a dibenzothiophene structure is preferred. From the viewpoint of durability against charge, a carbazole structure or an indolocarbazole structure is more preferred.

[0536] In the present invention, from the viewpoint of durability against charge of the organic electroluminescent element, it is preferred that at least one of the charge transport materials of the light-emitting layer is a material having a pyrimidine skeleton or a triazine skeleton.

[0537] From the perspective of excellent flexibility, the charge transport material of the light-emitting layer is preferably a polymer material. The light-emitting layer formed using a material with excellent flexibility is preferably used as the light-emitting layer of an organic electroluminescent element formed on a flexible substrate. When the charge transport material contained in the light-emitting layer is a polymer material, the molecular weight is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and even more preferably 10,000 to 100,000.

[0538] Furthermore, the charge transport material for the light-emitting layer is preferably a low molecular weight material from the perspectives of ease of synthesis and purification, ease of designing electron and hole transport properties, and ease of viscosity adjustment when dissolved in a solvent. When the charge transport material contained in the light-emitting layer is a low molecular weight material, the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less, preferably 300 or more, more preferably 350 or more, and even more preferably 400 or more.

[0539] (Fluorescent material) The fluorescent material is not particularly limited, but is preferably a compound represented by the following formula (211).

[0540] [Chemistry 106]

[0541] In the above formula (211), Ar 241 represents an aromatic hydrocarbon condensed ring structure which may have a substituent, Ar 242 、Ar 243 Each independently represents an alkyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by bonding these groups. n41 is an integer of 1 to 4.

[0542] Ar 241 It preferably represents an aromatic hydrocarbon condensed ring structure having 10 to 30 carbon atoms, and specific examples of the ring structure include naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, tetracene, Perylene, etc. Ar 241 More preferably, it is an aromatic hydrocarbon condensed ring structure having 12 to 20 carbon atoms. Specific examples of the ring structure include acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, tetracene, Perylene. Ar 241 More preferably, it is an aromatic hydrocarbon condensed ring structure having 16 to 18 carbon atoms. Specific examples of the ring structure include fluoranthene, pyrene,

[0543] n41 is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and most preferably 2.

[0544] As Ar 242 、Ar 243 The alkyl group is preferably an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. As Ar 242 、Ar 243 The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably an aromatic hydrocarbon group having 6 to 24 carbon atoms, and most preferably a phenyl group or a naphthyl group. As Ar 242 、Ar 243 The aromatic heterocyclic group is preferably an aromatic heterocyclic group having 3 to 30 carbon atoms, more preferably an aromatic heterocyclic group having 5 to 24 carbon atoms, specifically preferably a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group, more preferably a dibenzofuranyl group.

[0545] Ar 241 、Ar 242 、Ar 243 The substituent that may be possessed is preferably a group selected from the aforementioned substituent group S, more preferably a hydrocarbon group included in the substituent group S, and even more preferably a hydrocarbon group among the groups preferred as the substituent group S.

[0546] The charge transport material used together with the fluorescent material is not particularly limited, but is preferably a material represented by the following formula (212).

[0547] [Chemistry 107]

[0548] In the above formula (212), R 251 、R 252 Each independently represents a structure represented by the following formula (213), R 253 Indicates a substituent, there are multiple R 253 When n43 is an integer from 0 to 8, they may be the same or different.

[0549] [Chemistry 108]

[0550] In the above formula (213), * represents the bonding position to the anthracene ring of formula (212), Ar 254 、Ar 255 Each independently represents an aromatic hydrocarbon structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent, Ar 254 、Ar 255When a plurality of them exist, they may be the same or different, n44 is an integer of 1 to 5, and n45 is an integer of 0 to 5.

[0551] Ar 254 It is preferably a monocyclic or condensed aromatic hydrocarbon structure having 6 to 30 carbon atoms which may have a substituent, and more preferably a monocyclic or condensed aromatic hydrocarbon structure having 6 to 12 carbon atoms which may have a substituent.

[0552] Ar 255 Preferably, it is a monocyclic or condensed aromatic hydrocarbon structure having 6 to 30 carbon atoms which may have a substituent, or a condensed aromatic heterocyclic structure having 6 to 30 carbon atoms which may have a substituent. 255 More preferably, it is a monocyclic or condensed aromatic hydrocarbon structure having 6 to 12 carbon atoms which may have a substituent, or a condensed aromatic heterocyclic structure having 12 carbon atoms which may have a substituent.

[0553] n44 is preferably an integer of 1 to 3, more preferably 1 or 2. n45 is preferably an integer of 0-3, more preferably an integer of 0-2.

[0554] Substituent R 253 、Ar 254 and Ar 255 The substituent that may be present is preferably a group selected from the aforementioned substituent group S. More preferably, it is a hydrocarbon group included in the substituent group S, and even more preferably, it is a hydrocarbon group among the groups preferred as the substituent group S.

[0555] The molecular weight of the fluorescent material and the charge transport material is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less. Furthermore, it is preferably 300 or more, more preferably 350 or more, and even more preferably 400 or more.

[0556] [Hole blocking layer] A hole blocking layer may be provided between the light-emitting layer 5 and the electron injection layer described later. The hole blocking layer is a layer stacked on the light-emitting layer 5 so as to be in contact with the interface of the light-emitting layer 5 on the cathode 7 side.

[0557] The hole blocking layer has the function of blocking holes moving from the anode 2 from reaching the cathode 7 and the function of efficiently transporting electrons injected from the cathode 7 toward the light-emitting layer 5. The physical properties required of the material constituting the hole blocking layer include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and a high excited triplet energy level (T1).

[0558] As materials for the hole blocking layer that meet such conditions, there can be mentioned, for example: mixed ligand complexes such as bis(2-methyl-8-hydroxyquinolinolato)(phenol)aluminum, bis(2-methyl-8-hydroxyquinolinolato)(triphenylsilanol)aluminum, metal complexes such as bis(2-methyl-8-hydroxyquinolinolato)aluminum-μ-oxo-bis-(2-methyl-8-hydroxyquinolinolato)aluminum binuclear metal complexes, styryl compounds such as distyrylbiphenyl derivatives (Japanese Patent Publication No. 11-242996), triazole derivatives such as 3-(4-biphenyl)-4-phenyl-5(4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Publication No. 7-41759), and phenanthroline derivatives such as bathocuproin (Japanese Patent Publication No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at the 2-, 4-, or 6-positions as described in International Publication No. 2005 / 022962 are also preferred as materials for the hole-blocking layer.

[0559] There is no limitation on the method for forming the hole blocking layer, and the hole blocking layer may be formed by a wet film forming method, an evaporation method, or other methods.

[0560] The thickness of the hole blocking layer is arbitrary unless the effects of the present invention are significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[0561] <Electron Transport Layer> In order to further improve the current efficiency of the device, the electron transport layer 6 is provided between the light emitting layer 5 and the cathode 7 .

[0562] The electron transport layer 6 is formed of a compound that can efficiently transport electrons injected from the cathode 7 toward the light-emitting layer 5 between electrodes to which an electric field is applied. The electron transport compound used in the electron transport layer 6 needs to be a compound that has high electron injection efficiency from the cathode 7 and high electron mobility, and can efficiently transport the injected electrons.

[0563] Specific examples of the electron transport compound used in the electron transport layer include metal complexes such as an aluminum complex of 8-hydroxyquinoline (Japanese Patent Application Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, tribenzimidazolylbenzene (U.S. Patent No. 5,645,948), quinoxaline compounds (Japanese Patent Application Laid-Open No. 6-207169), phenanthroline derivatives (Japanese Patent Application Laid-Open No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinonediimide, N-type hydrogenated amorphous silicon carbide, N-type zinc sulfide, and N-type zinc selenide.

[0564] The thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0565] The electron transport layer 6 is formed by laminating on the hole blocking layer using the same wet film forming method or vacuum deposition method as described above. Usually, the vacuum deposition method is used. As described above, in the present invention, the electron transport layer can be formed by a wet film formation method on the light-emitting layer containing a suitable light-emitting layer-forming material.

[0566] <Electron Injection Layer> In order to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5 , an electron injection layer may be provided.

[0567] In order to effectively inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. As an example, alkali metals such as sodium or cesium, alkaline earth metals such as barium or calcium, etc. can be used. The film thickness is usually 0.1 nm or more, preferably 5 nm or less.

[0568] Furthermore, since doping organic electron transport materials represented by nitrogen-containing heterocyclic compounds such as bathophenanthroline or metal complexes such as aluminum complexes of 8-hydroxyquinoline with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (recorded in Japanese Patent Publication No. 10-270171, Japanese Patent Publication No. 2002-100478, Japanese Patent Publication No. 2002-100482, etc.) can also improve electron injection / transport properties while achieving excellent film quality, it is preferred.

[0569] The thickness of the electron injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

[0570] The electron injection layer is formed by laminating the hole blocking layer and the electron transport layer 6 on the light emitting layer 5 or thereon by a wet film forming method or a vacuum deposition method. The details of the wet film formation method are the same as those of the aforementioned light-emitting layer.

[0571] There is also a case where the hole blocking layer, the electron transport layer, and the electron injection layer are formed into one layer by co-doping an electron transport material and a lithium complex.

[0572] <Cathode> The cathode 7 plays a role in injecting electrons into a layer on the light-emitting layer 5 side (electron injection layer or light-emitting layer, etc.).

[0573] As the material of the cathode 7, the material used for the anode 2 described above can be used. However, in order to effectively inject electrons, it is preferable to use a metal with a low work function, such as tin, magnesium, indium, calcium, aluminum, silver, or an alloy thereof. Specific examples include low-work-function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0574] In order to improve the stability of the organic electroluminescent element, it is preferable to stack a metal layer with a high work function and good stability in the atmosphere on the cathode to protect the cathode made of a low work function metal. Examples of the metal to be stacked include aluminum, silver, copper, nickel, chromium, gold, and platinum.

[0575] The cathode film thickness is usually the same as the anode film thickness.

[0576] <Other layers> The organic electroluminescent device of the present invention may further include other layers, unless the effects of the present invention are significantly impaired. In other words, the organic electroluminescent device may include any other layers described above between the anode and the cathode.

[0577] <Other component configuration> The organic electroluminescent element of the present invention may also have a structure opposite to that described above, that is, for example, a cathode, an electron injection layer, an electron transport layer, a hole blocking layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode are sequentially stacked on a substrate.

[0578] When the organic electroluminescent element of the present invention is applied to an organic electroluminescent device, it can be used as a single organic electroluminescent element, or it can be made into a structure in which a plurality of organic electroluminescent elements are arranged in an array, or it can be made into a structure in which the anode and cathode are arranged in an XY matrix.

[0579] [Method for producing an organic electroluminescent element] The organic electroluminescent element of the present invention can be manufactured by a manufacturing method comprising the following steps, wherein the step uses the composition of the present invention and utilizes a wet film-forming method to form an organic layer. Preferably, the manufacturing method of an organic electroluminescent element having an anode and a cathode on a substrate and an organic layer between the anode and the cathode includes the step of using the composition of the present invention and utilizing a wet film-forming method to form the organic layer. The organic layer is more preferably an organic layer located between the anode and the light-emitting layer.

[0580] The organic electroluminescent element of the present invention is preferably an organic electroluminescent element produced by the above-mentioned production method.

[0581] [Display device] The display device (organic electroluminescent element display device) of the present invention includes the organic electroluminescent element of the present invention. The display device of the present invention is not particularly limited in its design or structure, and can be assembled using the organic electroluminescent element of the present invention in a conventional manner.

[0582] For example, the organic EL display device of the present invention can be formed by the method described in "Organic EL Display" (Ohmsha Co., Ltd., published on August 20, 2004, written by Shizuo Tokito, Chihaya Adachi, and Hideyuki Murata).

[0583] [lighting device] The lighting device of the present invention (organic electroluminescent element lighting device) includes the organic electroluminescent element of the present invention. The design and structure of the lighting device of the present invention are not particularly limited and can be assembled using the organic electroluminescent element of the present invention in a conventional manner. Example

[0584] The present invention will be described in more detail below with reference to the following examples. However, the present invention is not limited to the following examples, and the present invention can be implemented with any modifications without departing from the spirit of the present invention.

[0585] <Synthesis of Compound 7>

[0586] [Chemistry 109]

[0587] Under a nitrogen atmosphere, N,N-dimethylformamide (50 mL) was added to compound 1 (4.78 g, 50.8 mmol) and potassium carbonate (14.0 g, 101.6 mmol). Then, compound 2 (10.2 g, 55.1 mmol) dissolved in N,N-dimethylformamide (30 mL) was added and stirred at 70 ° C for 6 hours. Desalted water was added and extracted with ethyl acetate. The organic layer was washed with a saturated sodium chloride aqueous solution, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was treated by silica gel column chromatography to obtain compound 3 (amount 7.73 g, yield 78%).

[0588] [Chemistry 110]

[0589] Under a nitrogen atmosphere, N,N-dimethylformamide (30 mL) was added to compound 3 (1.83 g, 9.32 mmol), followed by N-bromosuccinimide (NBS, 1.66 g, 9.32 mmol). The mixture was stirred at room temperature for 8 hours, then desalted water was added and extracted with ethyl acetate. The organic layer was washed with a saturated sodium chloride aqueous solution, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was filtered and washed with methanol to obtain compound 4 (generated amount 2.10 g, yield 82%).

[0590] [Chemistry 111]

[0591] To compound 4 (2.03 g, 7.38 mmol) and compound 5 (2.40 g, 7.38 mmol) were added nitrogen-bubbled toluene (30 ml), ethanol (15 ml) and a potassium phosphate solution (2.0 mol / L, 15 mL) in sequence. Pd(PPh3)4 (85 mg, 0.074 mmol) was then added and stirred at 70°C for 5 hours. The mixture was cooled to room temperature, and then a saturated sodium chloride aqueous solution was added and extracted with toluene. The organic layer was washed with a saturated sodium chloride aqueous solution, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was treated by silica gel column chromatography to obtain compound 6 (generated amount 2.50 g, yield 86%).

[0592] [Chemistry 112]

[0593] Under a nitrogen stream, tetrahydrofuran (92 mL) and ethanol (23 mL) were added to compound 6 (2.54 g, 6.45 mmol), followed by palladium on carbon (10%, wet with approximately 55% water, 0.5 g). The mixture was stirred at 50°C for 10 minutes. Hydrazine monohydrate (2.15 ml) was then added dropwise, and the mixture was stirred at 50°C for 2.5 hours. The reaction mixture was filtered under reduced pressure through water-wetted celite, and the filtrate was concentrated to provide compound 7 (2.2 g, 95% yield).

[0594] <Synthesis of Compound 8, Compound 10, and Compound 11>

[0595] [Chemistry 113]

[0596] Compound 8, Compound 10, and Compound 11 were synthesized by the method described in International Publication No. 2019 / 177175.

[0597] <Example 1> [Synthesis of Polymer 1] Polymer 1 was synthesized according to the following reaction formula.

[0598] [Chemistry 114]

[0599] Compound 8 (1.5 g, 2.82 mmol), 2-amino-9,9-dihexylfluorene of compound 9 (0.857 g, 2.45 mmol), compound 7 (0.953 g, 2.62 mmol), compound 10 (0.555 g, 0.56 mmol), sodium tert-butoxide (2.09 g, 21.75 mmol) and toluene (45 ml) were added, the system was fully replaced with nitrogen, and the mixture was heated to 60°C (solution A1). To a solution of tris(dibenzylideneacetone)dipalladium complex (0.052 g, 0.057 mmol) in 9 ml of toluene was added [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.12 g, 0.45 mmol), and the mixture was heated to 60° C. (solution B1).

[0600] Under a nitrogen stream, solution B1 was added to solution A1 and heated under reflux for 1.0 hour. After confirming the disappearance of compound 7, compound 11 (1.022 g, 2.079 mmol) was added. After 1 hour, bromobenzene (1.24 g, 7.90 mmol) was added and heated under reflux for 2 hours. The reaction solution was cooled naturally and added dropwise to an ethanol / water solution (210 ml / 30 ml) to obtain a crude end-capped polymer.

[0601] The end-capped crude polymer was dissolved in toluene and subjected to secondary precipitation in acetone, and the precipitated polymer was filtered out. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and subjected to secondary precipitation with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain the target polymer 1 (2.2 g). The molecular weight of the obtained polymer 1 is shown below. Weight average molecular weight (Mw) = 13024 Number average molecular weight (Mn) = 9303 Dispersity (Mw / Mn) = 1.40

[0602] <Comparative Example 1> [Synthesis of Polymer 2] According to the following reaction formula, polymer 2 was synthesized.

[0603] [Chemistry 115]

[0604] Compound 12 was synthesized by the method described in International Publication No. 2020 / 171190.

[0605] 4,4'-Dibromo-p-terphenyl (2.0 g, 5.15 mmol), 2-amino-9,9-dihexylfluorene (3.21 g, 9.18 mmol), compound 12 (0.447 g, 1.12 mmol), sodium tert-butoxide (3.82 g, 39.75 mmol) and toluene (55 ml) were added, the system was fully replaced with nitrogen, and the temperature was raised to 60°C (solution A2). To a solution of tris(dibenzylideneacetone)dipalladium complex (0.094 g, 0.103 mmol) in 6 ml of toluene was added [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.219 g, 0.825 mmol), and the mixture was heated to 60° C. (solution B2).

[0606] Under a nitrogen stream, solution B2 was added to solution A2 and heated under reflux for 1 hour. After confirming the disappearance of compound 9, 2,7-bis(4-bromophenyl)-9,9-dihexylfluorene (2.38 g, 3.69 mmol) was added. After 1 hour, bromobenzene (2.31 g, 14.71 mmol) was added and heated under reflux for 2 hours. The reaction solution was cooled naturally and added dropwise to an ethanol / water solution (185 ml / 30 ml) to obtain a crude end-capped polymer.

[0607] The end-capped crude polymer was dissolved in toluene and subjected to secondary precipitation in acetone, and the precipitated polymer was filtered out. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and subjected to secondary precipitation with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain polymer 2 (1.9 g) as the target product. The molecular weight of the obtained polymer 2 is shown below. Weight average molecular weight (Mw) = 20310 Number average molecular weight (Mn) = 16510 Dispersion (Mw / Mn) = 1.23

[0608] <Comparative Example 2> [Synthesis of Polymer 3] According to the following reaction formula, polymer 3 was synthesized.

[0609] [Chemistry 116]

[0610] Compound 8 (1.68 g, 3.2 mmol), compound 9 (1.48 g, 4.2 mmol), compound 12 (0.33 g, 0.8 mmol), compound 10 (1.24 g, 1.3 mmol), sodium tert-butoxide (2.34 g, 24.3 mmol) and toluene (48 ml) were added, the system was fully replaced with nitrogen, and the temperature was raised to 60°C (solution A3). To a solution of tris(dibenzylideneacetone)dipalladium complex (0.058 g, 0.06 mmol) in 9 ml of toluene was added [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.13 g, 0.5 mmol), and the mixture was heated to 60° C. (solution B3).

[0611] Under a nitrogen stream, solution B3 was added to solution A3 and heated under reflux for 1.0 hour. After confirming the disappearance of compound 8, compound 11 (1.20 g, 2.4 mmol) was added. After 1 hour, bromobenzene (1.2 g, 7.7 mmol) was added and heated under reflux for 2 hours. The reaction solution was cooled naturally and added dropwise to 250 ml of ethanol to obtain a crude end-capped polymer.

[0612] The end-capped crude polymer was dissolved in toluene and subjected to secondary precipitation in acetone, and the precipitated polymer was filtered out. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and subjected to secondary precipitation with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain polymer 3 (2.7 g) as the target product. The molecular weight of the obtained polymer 3 is as follows. Weight average molecular weight (Mw) = 19350 Number average molecular weight (Mn) = 14770 Dispersity (Mw / Mn) = 1.31

[0613] <Crosslinking Temperature> When the polymer of Example 1 (Polymer 1) was subjected to differential scanning calorimetry (DSC, in air, heating rate of 10°C / min) using a DSC-50 manufactured by Shimadzu Corporation, heat generation associated with the crosslinking reaction was observed, and the peak starting point, which is the crosslinking initiation temperature, was 193°C. Similarly, when the polymer of Comparative Example 1 (Polymer 2) was subjected to differential scanning calorimetry, heat generation associated with the crosslinking reaction was observed, and the peak starting point was 209°C.

[0614] These results confirm that the specific crosslinking groups contained in polymer 1 undergo a crosslinking reaction at a temperature 16°C lower than that of 1,2-dihydrocyclobuta[a]naphthalene contained in polymer 2. Therefore, it is believed that the polymer of the present invention having a crosslinking group represented by formula (2) or (3) is insoluble in solvents at lower temperatures than conventional polymers having 1,2-dihydrocyclobuta[a]naphthalene as a crosslinking group. Therefore, the polymer of the present invention is able to remain insoluble at low temperatures.

[0615] <Evaluation of Solvent Resistance> Formation of a film for evaluating solvent resistance using the obtained polymer and evaluation of the solvent resistance of the obtained film were carried out as follows. First, a solution was prepared by dissolving the polymer 1 in anisole at a concentration of 2.0% by weight. The solution was dropped onto an ITO substrate in air, spin-coated, and dried on a hot plate at 100°C for 1 minute. The substrate was baked on a hot plate at 200°C, 210°C, 220°C, or 230°C to form a 60 nm thick film for solvent resistance evaluation.

[0616] Next, the substrate with the film for solvent resistance evaluation formed thereon was placed on a spin coater, and 150 μL of a test solvent was dripped onto the substrate. The substrate was then left to stand for 90 seconds as a solvent resistance test. Toluene was used as the test solvent. The substrate was then rotated at 1500 rpm for 30 seconds and then at 4000 rpm for 30 seconds to spin off the added solvent. The substrate was then dried on a hot plate at 145°C for 15 minutes. Solvent resistance was estimated based on the change in film thickness before and after the solvent resistance test.

[0617] Regarding polymer 3, a film for evaluating solvent resistance was prepared in the same manner as for polymer 1, and a solvent resistance test was performed.

[0618] The solvent resistance was evaluated based on the following criteria. ○: After the solvent resistance test, 70% or more of the film thickness before the solvent resistance test was observed to remain. ×: After the solvent resistance test, the film remaining was less than 70% of the film thickness before the solvent resistance test.

[0619] The results of the solvent resistance test of Polymer 1 and Polymer 3 are summarized in Table 1 below.

[0620] [Table 1] Table 1 Baking temperature Polymer 1 Polymer 3 200℃ ○ × 210℃ ○ × 220℃ ○ × 230℃ ○ ○

[0621] <Fabrication of Organic Electroluminescent Element> [Example 1] An organic electroluminescent device was produced by the following method. A 70nm thick transparent conductive film of indium tin oxide (ITO) (manufactured by Geomatec, a sputtered film) was deposited on a glass substrate and patterned into 2mm-wide stripes using conventional photolithography and hydrochloric acid etching to form an anode. The substrate with the ITO pattern was then cleaned sequentially with ultrasonic cleaning using a surfactant aqueous solution, then rinsed with ultrapure water, ultrasonic cleaning using ultrapure water, and finally rinsed with ultrapure water. The substrate was then dried with compressed air and finally cleaned with ultraviolet ozone.

[0622] As a hole injection layer-forming composition, the polymer 1 was dissolved in anisole at a concentration of 2.0 wt % and the electron-accepting compound (A-1) was dissolved in anisole at a concentration of 0.4 wt % to prepare the composition of the present invention. The composition was spin-coated on the substrate in the atmosphere and baked on a hot plate at 240° C. for 30 minutes in the atmosphere to form a uniform thin film with a thickness of 40 nm as a hole injection layer.

[0623] [Chemistry 117]

[0624] Next, a charge-transporting polymer compound having the following structural formula (HT-1) was dissolved in cyclohexylbenzene to prepare a 2.0 wt % solution. In a nitrogen glove box, the solution was spin-coated on a substrate coated with the hole injection layer, and baked at 230° C. for 30 minutes on a hot plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm as a hole transport layer.

[0625] [Chemistry 118]

[0626] Next, as materials for the light-emitting layer, a compound (H-1) having the following structure was dissolved in cyclohexylbenzene at a concentration of 1.2 wt %, (H-2) at a concentration of 1.2 wt %, (H-3) at a concentration of 0.80 wt %, and (D-1) at a concentration of 1.0 wt %, thereby preparing a composition for forming a light-emitting layer.

[0627] [Chemistry 119]

[0628] [Chemistry 120]

[0629] In a nitrogen glove box, the solution was spin-coated on the substrate coated with the hole transport layer and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 40 nm as the light-emitting layer. The substrate to which the light-emitting layer was formed was placed in a vacuum deposition device, and the inside of the device was evacuated to 2×10 -4 Below Pa.

[0630] Next, the following structural formula (ET-1) and 8-hydroxyquinolinol lithium were co-deposited on the light-emitting layer by vacuum deposition at a film thickness ratio of 2:3 to form an electron transport layer with a thickness of 30 nm.

[0631] [Chemistry 121]

[0632] Next, a 2mm-wide striped shadow mask was placed in close contact with the substrate, perpendicular to the ITO stripes of the anode, as a mask for cathode deposition. The aluminum was heated using a molybdenum boat to form an 80nm-thick aluminum layer, forming the cathode. This produced an organic electroluminescent device with a 2mm x 2mm luminescent area.

[0633] [Example 2] As the composition for forming a hole injection layer of the present invention, a composition is prepared by dissolving polymer 1 at a concentration of 2.0 weight % and an electron-accepting compound (A-2) at a concentration of 0.4 weight % in anisole, and the hole injection layer is formed using this composition. Except for this, an organic electroluminescent element is prepared in the same manner as in Example 1.

[0634] [Chemistry 122]

[0635] [Comparative Example 1] As a comparative composition for forming a hole injection layer, a composition was prepared by dissolving polymer 3 at a concentration of 2.0 wt% and an electron-accepting compound (A-1) at a concentration of 0.4 wt% in anisole. The hole injection layer was formed using this composition. Otherwise, an organic electroluminescent element was prepared in the same manner as in Example 1.

[0636] [Comparative Example 2] As a comparative composition for forming a hole injection layer, a composition was prepared by dissolving polymer 3 at a concentration of 2.0 wt% and an electron-accepting compound (A-2) at a concentration of 0.4 wt% in anisole. The hole injection layer was formed using this composition. Otherwise, an organic electroluminescent element was prepared in the same manner as in Example 1.

[0637] In the organic electroluminescent devices obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the 2 The time (LT95) required for the luminance to decrease to 90% of the initial luminance when the device is continuously energized is shown in Table 2. In Table 2, the values ​​of Examples 1 and 2 and Comparative Example 1 are relative values, with the value of Comparative Example 2 set to 1. The results in Table 2 show that the driving life of the organic electroluminescent device is improved when the polymer of the present invention is added to the composition.

[0638] [Table 2] Table 2

[0639] [Example 3] An organic electroluminescent device was produced by the following method. A 70nm thick transparent conductive film of indium tin oxide (ITO) (manufactured by Gioma Co., Ltd., sputtered) was deposited on a glass substrate and patterned into 2mm-wide stripes using conventional photolithography and hydrochloric acid etching to form an anode. The substrate with the ITO pattern was then cleaned sequentially with ultrasonic cleaning using a surfactant aqueous solution, then rinsed with ultrapure water, ultrasonic cleaning using ultrapure water, and finally rinsed with ultrapure water. The substrate was then dried with compressed air and finally cleaned with ultraviolet ozone.

[0640] As a hole injection layer-forming composition, the polymer 1 was dissolved in anisole at a concentration of 2.0 wt % and the electron-accepting compound (A-1) was dissolved in anisole at a concentration of 0.4 wt % to prepare the composition of the present invention. The composition was spin-coated on the substrate in the atmosphere and baked on a hot plate at 240° C. for 30 minutes in the atmosphere to form a uniform thin film with a thickness of 40 nm as a hole injection layer.

[0641] Next, a charge-transporting polymer compound having the following structural formula (HT-1) was dissolved in cyclohexylbenzene to prepare a 2.0 wt % solution. In a nitrogen glove box, the solution was spin-coated on a substrate coated with the hole injection layer, and baked at 230° C. for 30 minutes on a hot plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm as a hole transport layer.

[0642] [Chemistry 123]

[0643] Next, as materials for the light-emitting layer, compound (H-4) having the following structure was dissolved in cyclohexylbenzene at a concentration of 3.8 wt % and (D-2) at a concentration of 0.38 wt %, thereby preparing a light-emitting layer-forming composition.

[0644] [Chemistry 124]

[0645] In a nitrogen glove box, the solution was spin-coated on the substrate coated with the hole transport layer and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 40 nm as the light-emitting layer. After forming the light-emitting layer, an organic electroluminescent device was produced in the same manner as in Example 1.

[0646] [Comparative Example 3] As a comparative composition for forming a hole injection layer, a composition was prepared by dissolving polymer 3 at a concentration of 2.0 wt% and an electron-accepting compound (A-1) at a concentration of 0.4 wt% in anisole. The hole injection layer was formed using this composition. Otherwise, an organic electroluminescent element was prepared in the same manner as in Example 3.

[0647] The organic electroluminescent devices obtained in Example 3 and Comparative Example 3 were measured at 1,000 cd / m 2 Current efficiency (cd / A) during luminescence. In addition, the organic electroluminescent devices obtained in Example 3 and Comparative Example 3 were measured at 20 mA / cm 2 The time (LT95) required for the luminance to decrease to 95% of the initial luminance when the device was continuously energized was calculated. The results of these measurements are shown in Table 3. In Table 3, the values ​​of Example 3 are relative values ​​with the values ​​of Comparative Example 3 set to 1. The results in Table 3 show that the luminous efficiency and driving life of the organic electroluminescent device are improved when the polymer of the present invention is added to the composition.

[0648] [Table 3] Table 3

[0649] While various embodiments have been described above, it goes without saying that the present invention is not limited to the examples described. Those skilled in the art will appreciate that various variations or modifications are conceivable within the scope of the claims, and these naturally fall within the technical scope of the present invention. Furthermore, the various components of the above embodiments may be arbitrarily combined without departing from the spirit of the invention.

[0650] It should be noted that this application is based on the Japanese patent application (Japanese Patent Application No. 2023-026165) filed on February 22, 2023, the contents of which are incorporated herein by reference. Industrial applicability

[0651] Since the polymer of the present invention has excellent electrochemical stability, it is conceivable that elements comprising a layer formed using the polymer may be applied to, for example, flat-panel displays (e.g., for OA computers, wall-mounted televisions), car-mounted display elements, mobile phone displays, light sources that effectively utilize the characteristics of surface-emitting bodies (e.g., light sources for copiers, liquid crystal displays, backlight sources for measuring instruments), display panels, and indicator lights.

Claims

1. A polymer comprising a repeating unit represented by the following formula (1), In formula (1), Ar 1 represents a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the above divalent aromatic hydrocarbon groups and the above divalent aromatic heterocyclic groups are linked directly or via a linking group, Ar 2 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by connecting a plurality of groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups, Ar 1 with Ar 2 forming a ring via a single bond or a linking group, or not forming a ring, Ar 1 with or without substituents, Ar 2 with or without substituents, Ar 2 having at least one cross-linking group represented by formula (2) or formula (3), In formula (2) and formula (3), Ar 3 ~Ar 5 Each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent, Ar 6 represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent, R 1 represents a hydrogen atom, or a monovalent alkyl group which may be substituted, a monovalent alkenyl group which may be substituted, a monovalent alkynyl group which may be substituted, a monovalent alkoxy group which may be substituted, a monovalent aromatic hydrocarbon group, or a monovalent aromatic heterocyclic group which may be substituted, HA 1 represents an oxygen atom or a sulfur atom, n1 represents an integer from 1 to 5, n2 represents an integer from 0 to 5, n3 represents an integer from 0 to 5, "-*" indicates the position of bonding to formula (1).

2. The polymer according to claim 1, wherein Ar 2 Having HA selected from formula (2) 1 The cross-linking group is an oxygen atom and HA in formula (3) 1 At least one of the group consisting of cross-linking groups consisting of oxygen atoms.

3. The polymer according to claim 1, wherein Ar 2 Having Ar selected from formula (2) 3 is a cross-linking group of a benzene ring and Ar in formula (3) 6 At least one of the group consisting of cross-linking groups which is a phenyl group.

4. The polymer according to claim 1, wherein The cross-linking group represented by the formula (2) is selected from the following structural groups, "-*" indicates the position of bonding to formula (1).

5. The polymer according to claim 1, wherein The cross-linking group represented by the formula (3) is selected from the following structural groups, "-*" indicates the position of bonding to formula (1).

6. The polymer according to claim 1, wherein The repeating unit represented by formula (1) is a repeating unit represented by the following formula (1-1), (1-2), (1-3), (1-4) or (1-5), In formula (1-1), Ar 2 and Ar in the formula (1) 2 same, X is -C(R 207 )(R 208 )-、-N(R 209 )-or-C(R 211 )(R 212 )-C(R 213 )(R 214 )-, R 201 、R 202 、R 221 and R 222 are each independently an alkyl group which may have a substituent, R 207 ~R 209 and R 211 ~R 214 are each independently a hydrogen atom, an alkyl group which may be substituted, an aralkyl group which may be substituted, or an aromatic hydrocarbon group which may be substituted, a and b are each independently an integer from 0 to 4, c is an integer from 0 to 3, d is an integer from 0 to 4, i and j are each independently an integer from 0 to 3, Where a×c+b×d+i+j is greater than 1, In formula (1-2), Ar 2 and Ar in the formula (1) 2 same, R 303 and R 306 Each independently represents an alkyl group which may have a substituent, R 304 and R 305 each independently represents an alkyl group which may be substituted, an alkoxy group which may be substituted, or an aralkyl group which may be substituted, l is 0 or 1, m is 1 or 2, n is 0 or 1, p is 0 or 1, q is 0 or 1, In formula (1-3), Ar 2 and Ar in the formula (1) 2 same, Ar 41 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of at least one group selected from the group consisting of the above divalent aromatic hydrocarbon groups and the above divalent aromatic heterocyclic groups are linked directly or via a linking group, R 441 and R 442 Each independently represents an alkyl group which may have a substituent, t is 1 or 2, u is 0 or 1, r and s are each independently an integer from 0 to 4, Among them, r×t+s×u is greater than 1, In formula (1-4), Ar 2 and Ar in the formula (1) 2 same, R 517 ~R 519 each independently represents an alkyl group which may be substituted, an alkoxy group which may be substituted, an aralkyl group which may be substituted, an aromatic hydrocarbon group which may be substituted, or an aromatic heterocyclic group which may be substituted, f, g, and h are each independently an integer of 0 to 4, e is an integer from 0 to 3, When g is an integer greater than or equal to 1, e is an integer greater than or equal to 1. Where, f+e×g+h is greater than 1, In formula (1-5), Ar 2 and Ar in the formula (1) 2 same, n60 is an integer from 1 to 5.

7. The polymer according to claim 6, wherein The repeating unit represented by the formula (1-1) is a repeating unit represented by the following formula (1-1-1), In formula (1-1-1), Ar 2 , X, R 201 、R 202 、R 221 、R 222 , a, b, c, d and Ar in the formula (1-1) 2 , X, R 201 、R 202 、R 221 、R 222 , a, b, c, d are the same, a1, a2, b1, b2, i1, i2, j1, j2 each independently represent 0 or 1, Among them, a, b, c, d, a1, a2, b1, b2, i1, i2, j1, j2 meet any of the following conditions (1) and (2), Condition (1) At least one of a1, a2, and a is an integer greater than or equal to 1, at least one of b1, b2, and b is an integer greater than or equal to 1, c is an integer greater than or equal to 1, and d is an integer greater than or equal to 1. When c is 1, at least one of a1 or a2 is 1, and when d is 1, at least one of b1 or b2 is 1. Condition (2) At least one of i1, i2, j1 and j2 is 1, Ring A1 refers to rings with or without R at specific positions. 201 The divalent benzene ring, Ring A2 refers to a ring with or without R 201 A divalent group formed by connecting c-1 benzene rings, wherein when c is 1, it refers to a monocyclic divalent benzene ring, Ring A3 refers to a divalent condensed ring formed by further bonding a biphenyl structure to X. Ring A4 refers to a ring with or without R 202 A divalent group formed by connecting d-1 benzene rings, wherein when d is 1, it refers to a monocyclic divalent benzene ring, Ring A5 refers to rings with or without R at specific positions. 202 divalent benzene ring.

8. The polymer according to claim 6, wherein Ar present in the repeating unit represented by formula (1) 1 ~Ar 6 、Ar 41 、R 201 、R 202 、R 221 、R 222 、R 207 ~R 209 、R 211 ~R 214 、R 301 、R 304 ~R 306 、R 441 、R 442 and R 517 ~R 519 None of them has a substituent. 9 . A composition comprising the polymer according to claim 1 and an electron-accepting compound.

10. The composition according to claim 9, wherein The electron-accepting compound is represented by the following formula (81): In formula (81), 5 R 81 , 5 Rs 82 , 5 Rs 83 , 5 Rs 84 Each is independent and R 81 ~R 84 each independently represents a hydrogen atom, a deuterium atom, a halogen atom, an aromatic hydrocarbon group having 6 to 50 carbon atoms which may be substituted, an aromatic heterocyclic group having 3 to 50 carbon atoms which may be substituted, a fluorine-substituted alkyl group having 1 to 12 carbon atoms, or a crosslinking group, Ph 1 、Ph 2 、Ph 3 、Ph 4 are symbols representing individual benzene rings. X + represents the counter cation, Wherein, formula (81) has at least 2 cross-linking groups.

11. The composition according to claim 10, wherein *-Ph in the formula (81) 1 -(R 81 )5. *-Ph 2 -(R 82 )5. *-Ph 3 -(R 83 )5. *-Ph 4 -(R 84 ) 5, at least one of which is a group represented by the following formula (84) having 4 fluorine atoms, In formula (84), * represents the position of bonding with boron B in formula (81), F4 represents substitution with four fluorine atoms, R 85 represents an aromatic hydrocarbon group which may have a substituent and / or a cross-linking group, or a cross-linking group.

12. The composition according to claim 10, wherein The electron-accepting compound represented by the formula (81) has at least one crosslinking group selected from the following crosslinking group group T of formulas (X1) to (X17), <Crosslinking Group T> In formulas (X1) to (X17), Q represents a direct bond or a linking group, "*" indicates the bonding position, R in formula (X3), formula (X4), formula (X5) and formula (X9) 110 represents a hydrogen atom or an alkyl group which may have a substituent, In formulas (X1) to (X3), the benzene ring and the naphthalene ring may or may not have a substituent, and the substituents may be bonded to each other to form a ring or not. In formula (X1) and formula (X2), the cyclobutene ring may have a substituent.

13. The composition according to claim 12, wherein The electron-accepting compound represented by the formula (81) has at least one crosslinking group selected from the group consisting of the formulas (X1) to (X3). The composition according to claim 9 , further comprising a solvent.

15. A method for manufacturing an organic electroluminescent element, wherein: The organic electroluminescent element has an anode and a cathode on a substrate and an organic layer between the anode and the cathode. The manufacturing method includes the following steps: The organic layer is formed using the composition according to claim 14 by a wet film-forming method.

16. The method for manufacturing an organic electroluminescent element according to claim 15, wherein: The organic layer is located between the anode and the light-emitting layer.

17. An organic electroluminescent element, wherein: An anode and a cathode are provided on a substrate, and an organic layer is provided between the anode and the cathode, wherein the organic layer contains a crosslinked reaction product of a polymer containing a repeating unit represented by the following formula (1) and an electron-accepting compound, In formula (1), Ar 1 represents a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, or a divalent group in which a plurality of at least one group selected from the group consisting of the above divalent aromatic hydrocarbon groups and the above divalent aromatic heterocyclic groups are linked directly or via a linking group, Ar 2 represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group formed by connecting a plurality of groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups, Ar 1 with Ar 2 forming a ring via a single bond or a linking group, or not forming a ring, Ar 1 with or without substituents, Ar 2 with or without substituents, Ar 2 having at least one cross-linking group represented by formula (2) or formula (3), In formula (2) and formula (3), Ar 3 ~Ar 5 Each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent, Ar 6 represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent, R 1 represents a hydrogen atom, or a monovalent alkyl group which may be substituted, a monovalent alkenyl group which may be substituted, a monovalent alkynyl group which may be substituted, a monovalent alkoxy group which may be substituted, a monovalent aromatic hydrocarbon group, or a monovalent aromatic heterocyclic group which may be substituted, HA 1 represents an oxygen atom or a sulfur atom, n1 represents an integer from 1 to 5, n2 represents an integer from 0 to 5, n3 represents an integer from 0 to 5, "-*" indicates the position of bonding to formula (1).

18. The organic electroluminescent element according to claim 17, wherein The electron-accepting compound is represented by the following formula (81), In formula (81), 5 R 81 , 5 Rs 82 , 5 Rs 83 , 5 Rs 84 Each is independent and R 81 ~R 84 each independently represents a hydrogen atom, a deuterium atom, a halogen atom, an aromatic hydrocarbon group having 6 to 50 carbon atoms which may be substituted, an aromatic heterocyclic group having 3 to 50 carbon atoms which may be substituted, a fluorine-substituted alkyl group having 1 to 12 carbon atoms, or a crosslinking group, Ph 1 、Ph 2 、Ph 3 、Ph 4 are symbols representing individual benzene rings. X + represents the counter cation, Wherein, formula (81) has at least 2 cross-linking groups. 19 . An organic electroluminescent device produced by the method for producing an organic electroluminescent device according to claim 15 . 20 . A display device comprising the organic electroluminescent element according to claim 17 .

21. A lighting device comprising the organic electroluminescent element according to claim 17.

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