polymer

Abstract

Provided is a polymer that has a high excited singlet level (S1) and a high excited triplet level (T1), suppresses quenching due to energy transfer from a light-emitting material or a light-emitting exciton, and has a high light-emitting efficiency, and a composition for an organic electroluminescent element containing the polymer. The present invention relates to a polymer containing a repeating unit represented by the following formula (1). The definitions of the respective groups in formula (1) are the same as the definitions described in the specification.

Description

Technical Field

[0001] This invention relates to a polymer, and more specifically, to a polymer useful as a charge-transporting material for organic electroluminescent elements. Furthermore, this invention relates to compositions for organic electroluminescent elements containing the polymer, organic electroluminescent elements comprising layers formed using the composition, and organic EL display devices and organic EL lighting having the organic electroluminescent elements. Background Technology

[0002] Methods for forming the organic layer in organic electroluminescent devices include vacuum evaporation and wet deposition. Vacuum evaporation offers advantages such as improved charge injection from the anode and / or cathode and easier encapsulation of excitons within the light-emitting layer due to its ease of layering. On the other hand, wet deposition offers advantages such as eliminating the need for a vacuum process, ease of large-area application, and the ability to easily form layers containing various functional materials using a coating solution mixed with multiple materials.

[0003] However, wet film deposition methods are difficult to stack, resulting in poorer driving stability compared to components obtained using vacuum evaporation methods. Currently, except for a few, they cannot reach practical levels.

[0004] Therefore, charge-transporting polymers that can be laminated based on wet film formation methods are being developed.

[0005] Patent documents 1 and 2 disclose a hole injection transport material with a structure in which a fluorene ring or carbazole ring is bonded to a benzene ring in the main chain of a polymer.

[0006] Patent document 3 discloses polymers having repeating triarylamine units and polymers whose main chain contains fluorene rings. Furthermore, it describes increasing the triplet energy of the polymer by incorporating a substituent-containing phenylene group into the polymer main chain to induce torsion.

[0007] Patent document 4 discloses a polymer having a main chain of triarylamine and fluorene, and a polymer that is twisted by setting a substituent on a phenylene atom adjacent to a nitrogen atom.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2016-084370

[0011] Patent Document 2: Japanese Patent Application Publication No. 2017-002287

[0012] Patent Document 3: Japanese Patent Publication No. 2007-520858

[0013] Patent Document 4: International Publication No. 2019 / 177175 Summary of the Invention

[0014] However, through the research of the inventors, it was found that the technologies disclosed in the aforementioned patent documents have the following problems.

[0015] The polymers described in Patent Documents 1 and 2 suffer from low excited singlet (S1) and excited triplet (T1) energy levels due to the extension of the π-conjugated system in the main chain, resulting in quenching caused by energy transfer from the luminescent material and excitons, thus reducing luminescence efficiency. Therefore, a charge transport material with high S1 and T1 energy levels is desired.

[0016] Patent Document 3 discloses a method to increase the triplet energy of a polymer by generating a torsion effect by including a phenylene oxide with a substituent, and general formula (III) as an example. However, Patent Document 3 does not disclose a polymer that can solve the above-mentioned problem. The same is true for Patent Document 4.

[0017] The objective of this invention is to provide a polymer with high excited singlet (S1) and excited triplet (T1) energy levels, high luminous efficiency, suppression of quenching caused by energy transfer from the luminescent material and luminescent excitons, and a composition for an organic electroluminescent element comprising the polymer.

[0018] The inventors conducted in-depth research and found that the above-mentioned problems could be solved by using polymers with specific repeating units, thus completing the present invention.

[0019] That is, the essence of the present invention is contained in the following <1> to <17>.

[0020] <1> A polymer comprising repeating units represented by the following formula (1).

[0021]

[0022] In equation (1),

[0023] Ar 1 This indicates a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0024] Ar 2 and Ar 3 Each can independently represent a divalent aromatic hydrocarbon group that may have substituents, or a divalent group formed by multiple aromatic hydrocarbon groups that may have substituents being directly or indirectly connected in the main chain direction by linking groups.

[0025] X represents -C(R) 7 (R) 8 )-、-N(R 9 ) - or - C(R 10 (R) 11 )-C(R 12 (R) 13 )-,

[0026] R 1 ~R 8 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0027] R 1 R 2 R 5 R 6 At least one of them is an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0028] R 9 ~R 13 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, an aralkyl group that may have substituents, or an aromatic hydrocarbon group that may have substituents.

[0029] n represents an integer from 1 to 3.

[0030] Among them, the two structures of the nitrogen atom of the main chain amine that constitute the polymer backbone and are directly bonded to the main chain amine of formula (1) are both phenylene oxides that can have substituents.

[0031] <2> According to the polymer described in <1>, wherein, in the above formula (1), with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is not the nitrogen atom of the main chain amine, in Ar 2 The structure shown is a phenylene group without substituents, in which the nitrogen atom of the main chain amine is bonded.

[0032] with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is the nitrogen atom of the main chain amine, at least one of the following conditions must be satisfied: In Ar 2 The structure shown is a phenylene group without substituents bonded to the nitrogen atom of the main chain amine, and in Ar... 3 The structure represented by Ar 3 The structure in the adjacent-bonded repeating unit that is directly bonded to the nitrogen atom of the main chain amine is a phenylene without substituents.

[0033] <3> According to <1> or <2> the polymer, wherein the two structures in the main chain of the polymer that are bonded to the nitrogen atom of the main chain amine in the above formula (1) are phenylene oxides without substituents.

[0034] <4> The polymer according to any one of <1> to <3>, wherein the above formula (1) is represented by the following formula (2)-1 or the following formula (2)-2.

[0035]

[0036] In equation (2)-1 or equation (2)-2,

[0037] Ar 1 R 1 ~R 6 X is defined in the same way as in equation (1) above.

[0038] R 20 ~R 23 Each independently with R 1 same,

[0039] g, h, and i each independently represent integers from 1 to 3.

[0040] j and k each independently represent integers from 1 to 2.

[0041] <5> The polymer according to any one of <1> to <4>, wherein it further comprises at least one of the repeating units represented by formula (3)-1 and the repeating units represented by formula (3)-2.

[0042]

[0043] In equation (3)-1 or equation (3)-2,

[0044] Ar 4 Each repeating unit independently represents a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0045] X 30 Represents -C(R) 37 (R) 38 )-、-N(R 39 ) - or - C(R 40 (R) 41 )-C(R 42 (R) 43 )-,

[0046] R 33 R 34 R 37 R 38 R 120 ~R 123 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0047] R 39 ~R 43 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, an aralkyl group that may have substituents, or an aromatic hydrocarbon group that may have substituents.

[0048] g 3 h 3 i 3 Each can independently represent an integer from 1 to 3.

[0049] j 3 k 3 Each can independently represent an integer from 1 to 2.

[0050] <6> The polymer according to any one of <1> to <5>, wherein Ar 1 It is represented by the following formula (A1).

[0051]

[0052] In formula (A1),

[0053] Ar 6 and Ar 7 Each can independently represent a divalent aromatic hydrocarbon group that may have substituents, a divalent aromatic heterocyclic group that may have substituents, or a divalent group formed by multiple groups selected from both substituent aromatic hydrocarbon groups and substituent aromatic heterocyclic groups, either directly or indirectly linked by a linking group.

[0054] Ar 8 This indicates a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0055] Ar 9 Represents a hydrogen atom or a substituent.

[0056] -* indicates the bonding position with the nitrogen atom in the above formula (1).

[0057] <7> According to the polymer described in <5> or <6>, wherein Ar 4It is represented by the following formula (A2).

[0058]

[0059] In formula (A2),

[0060] Ar 36 and Ar 37 Each can independently represent a divalent aromatic hydrocarbon group that may have substituents, a divalent aromatic heterocyclic group that may have substituents, or a divalent group formed by multiple groups selected from both substituent aromatic hydrocarbon groups and substituent aromatic heterocyclic groups, either directly or indirectly linked by a linking group.

[0061] Ar 38 This indicates a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0062] Ar 39 Represents a hydrogen atom or a substituent.

[0063] -* indicates the bonding position with the nitrogen atom in formula (3)-1 or formula (3)-2 above.

[0064] <8> The polymer according to any one of <1> to <7>, wherein R 1 and R 2 Each can independently represent an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0065] <9> The polymer according to any one of <1> to <8>, wherein the polymer has crosslinking groups as substituents.

[0066] <10> The polymer according to any one of <1> to <9>, wherein the weight-average molecular weight (Mw) is 10,000 or more and the dispersion (Mw / Mn) is 3.5 or less.

[0067] <11> A composition for an organic electroluminescent element, comprising the polymer described in any one of <1> to <10>.

[0068] <12> 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 is provided between the anode and the cathode.

[0069] The manufacturing method comprises the following steps: forming the organic layer described above using the organic electroluminescent element composition described in <11> by a wet film deposition method.

[0070] <13> The method for manufacturing an organic electroluminescent element according to <12>, wherein the organic layer has at least one of a hole injection layer and a hole transport layer.

[0071] <14> The method for manufacturing an organic electroluminescent element according to <13> includes, between the anode and the cathode, the hole injection layer, the hole transport layer, and the light-emitting layer.

[0072] The organic layer described above has the hole injection layer, the hole transport layer, and the light-emitting layer described above.

[0073] <15> An organic electroluminescent element comprising a layer of a polymer containing any one of <1> to <10>, or a polymer obtained by crosslinking the aforementioned polymers.

[0074] <16> An organic EL display device comprising the organic electroluminescent element described in <15>.

[0075] <17> An organic EL lighting, comprising the organic electroluminescent element described in <15>.

[0076] According to the present invention, it is possible to provide a polymer with high excited singlet level (S1) and excited triplet level (T1), high luminous efficiency, suppression of quenching caused by energy transfer from the luminescent material and luminescent excitons, and a composition for an organic electroluminescent element comprising the polymer. Attached Figure Description

[0077] Figure 1 This is a schematic cross-sectional view showing a structural example of the organic electroluminescent element of the present invention. Detailed Implementation

[0078] The embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be implemented in various ways within the scope of its spirit.

[0079] <Polymer>

[0080] The polymer of the present invention is a polymer comprising the structure represented by the following formula (1).

[0081]

[0082] In equation (1),

[0083] Ar 1This indicates a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0084] Ar 2 and Ar 3 Each can independently represent a divalent aromatic hydrocarbon group that may have substituents, or a divalent group formed by multiple aromatic hydrocarbon groups that may have substituents being directly or indirectly connected in the main chain direction by linking groups.

[0085] X represents -C(R) 7 (R) 8 )-、-N(R 9 ) - or - C(R 10 (R) 11 )-C(R 12 (R) 13 )-,

[0086] R 1 ~R 8 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0087] R 1 R 2 R 5 R 6 At least one of them is an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0088] R 9 ~R 13 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, an aralkyl group that may have substituents, or an aromatic hydrocarbon group that may have substituents.

[0089] n represents an integer from 1 to 3.

[0090] At this point, the two structures that constitute the main chain of the polymer and are directly bonded to the nitrogen atom of the main chain amine of formula (1) are preferably phenylene oxides that can have substituents.

[0091] In addition, with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is not the nitrogen atom of the main chain amine, Ar 2 The ring bonded to the nitrogen atom of the main chain amine does not have substituents.

[0092] with Ar 3Adjacent bonded repeating units with Ar 3 When the bonded atom is the nitrogen atom of the main chain amine, it is preferable to satisfy at least one of the following conditions, namely, Ar 2 The ring bonded to the nitrogen atom of the main chain amine in the amine does not have substituents, and Ar 3 The ring bonded to the nitrogen atom of the main chain amine does not have substituents.

[0093] Furthermore, with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is not the nitrogen atom of the main chain amine, in Ar 2 The structure shown is a phenylene group without substituents, in which the nitrogen atom of the main chain amine is bonded.

[0094] with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is the nitrogen atom of the main chain amine, it is preferable to satisfy at least one of the following conditions, namely, in Ar 2 The structure shown is a phenylene group without substituents bonded to the nitrogen atom of the main chain amine, and in Ar... 3 The structure represented by Ar 3 The structure of the repeating unit with adjacent bonding that is bonded to the nitrogen atom of the main chain amine is a phenylene without substituents.

[0095] It should be noted that, with Ar 3 Adjacent bonded repeating units with Ar 3 In the case where the bonded atom is not the nitrogen atom of the main chain amine, in Ar 2 The structure shown is an Ar-type phenylene group with no substituents, bonded to the nitrogen atom of the main chain amine. 2 This refers to the expression Ar 2 The R mentioned later in equation (1)-4 62 A structure consisting entirely of hydrogen.

[0096] In addition, with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is the nitrogen atom of the main chain amine,

[0097] In Ar 2 The structure shown is an Ar-type phenylene group with no substituents, bonded to the nitrogen atom of the main chain amine. 2 This refers to Ar 2 The R mentioned later in equation (1)-4 62 A structure consisting entirely of hydrogen.

[0098] In Ar 3 The structure represented by Ar 3The structure of the repeating unit with adjacent bonding bonded to the nitrogen atom of the main chain amine is an Ar-type phenylene group without substituents. 3 This refers to Ar 3 The R mentioned later in equation (1)-5 63 It has a structure consisting entirely of hydrogen.

[0099] The reason why the polymer of the present invention achieves the above-mentioned effects is not yet clear, but it is believed to be as follows.

[0100] The polymer of the present invention comprises a main chain containing a fluorene ring having a substituent at a specific position, a carbazole ring having a substituent at a specific position, or a 9,10-dihydrophenanthrene derivative structure having a substituent at a specific position, by including the structure represented by formula (1) above. Preferably, a phenylene group is bonded at the 2,7-position in these fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structures. A specific position refers to R... 1 R 2 R 5 or R 6 The replacement position.

[0101] Through these fluorene rings, carbazole rings, or 9,10-dihydrophenanthrene derivative structures, R 1 R 2 R 5 or R 6 The substitution sites have substituents, which introduce steric hindrance. Therefore, the facets of the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure are more twisted relative to the facets of the rings bonded at positions 2 or 7 in these structures. In this case, the polymer of the present invention has a main-chain structure where the extension of the π-conjugated system is hindered due to the steric hindrance of the substituents. Therefore, it exhibits high excited singlet (S1) and excited triplet (T1) energy levels, and quenching caused by energy transfer from the luminescent excitons is suppressed, resulting in excellent luminescence efficiency.

[0102] Furthermore, since the two structures in the main chain of the polymer that are directly bonded to the nitrogen atom of the main chain amine in formula (1) are monocyclic phenylene, the T1 and S1 energy levels are higher, which is preferred.

[0103] Conventionally, as in Patent Document 4, substituents are placed on the ring such as the phenylene bonded to the nitrogen atom, forming a twist with the adjacent fluorene or similar structures. When substituents are introduced into the ring bonded to the nitrogen atom of the main-chain amine, it is believed that the presence of the substituents hinders the expansion of the HOMO around the nitrogen atom, thus weakening electronic durability. In this invention, when the ring bonded to the nitrogen atom of the main-chain amine does not have substituents, the expansion of the HOMO around the nitrogen atom is not hindered, and the HOMO extends to the ring adjacent to the nitrogen atom, achieving higher electronic durability. As a result, it is believed that an organic electroluminescent element with a long driving lifetime can be obtained while maintaining high luminous efficiency.

[0104] In this invention, when the ring bonded to the nitrogen atom of the main-chain amine does not have substituents, the expansion of the HOMO around the nitrogen atom is not hindered, and the HOMO extends to the ring adjacent to the nitrogen atom, thus achieving high electronic durability. As a result, it is believed that an organic electroluminescent element with a long driving lifetime can be obtained while maintaining high luminous efficiency.

[0105] In addition, it is believed that R 1 R 2 R 5 and R 6 The structures of at least one of the fluorene ring, carbazole ring or 9,10-dihydrophenanthrene derivatives with substituents can become more electrically stable and thus have higher durability by bonding an aromatic ring at the 2,7-position.

[0106] Furthermore, when fluorene rings, carbazole rings, or 9,10-dihydrophenanthrene derivative structures are bonded to electron-withdrawing groups, the LUMO is entirely distributed within the conjugated group extended from the 9-position of the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure. On the other hand, it is believed that because the HOMO is distributed in the main chain near the amine, the intramolecular HOMO is separated from the LUMO and localized, thus exhibiting a tendency to increase the durability of electrons and excitons.

[0107] It is believed that if the energy level difference between the organic layers in an organic electroluminescent device is inappropriate, it will be difficult to inject carriers into the light-emitting layer, leading to an increase in the driving voltage. Alternatively, carrier leakage from the light-emitting layer to adjacent layers may easily occur, resulting in a decrease in device efficiency.

[0108] In contrast, a charge transport material having a higher energy level than the excitons of the luminescent material present in the luminescent layer, as in this invention, is more effective at sealing the excitons of the luminescent material and is therefore preferred.

[0109] Furthermore, the layer obtained by wet film deposition using an organic electroluminescent element composition containing the polymer of the present invention does not produce cracks and is relatively flat. As a result, the organic electroluminescent element of the present invention having this layer has high brightness and long driving life.

[0110] Furthermore, due to the excellent electrochemical stability of the polymer of the present invention, it is believed that organic electroluminescent elements containing layers formed using the polymer of the present invention can be applied to flat panel displays (e.g., for OA computers, wall-mounted TVs), automotive display elements, mobile phone displays, light sources utilizing the characteristics of surface light emitters (e.g., light sources for copiers, liquid crystal displays, backlights for measuring instruments), display panels, and indicator lights, and their technical value is enormous.

[0111] (Ar 1 )

[0112] Ar 1 It refers to a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by directly or indirectly connecting multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0113] In the polymer of the present invention, Ar 1 When multiple Ar exist, multiple Ar 1 They can be the same or different.

[0114] As a monovalent aromatic hydrocarbon group, an aromatic hydrocarbon group with 6 to 60 carbon atoms is preferred. Specifically, examples include benzene rings, azurite rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. Monovalent groups of six-membered rings, such as triphenylene ring, acenaphthene ring, fluoranthene ring, and fluorene ring, or monocyclic or di- to pentacyclic fused rings.

[0115] As a monovalent aromatic heterocyclic group, an aromatic heterocyclic group with 3 to 60 carbon atoms is preferred. Specifically, examples include furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, and imidazole rings. Diazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrazole ring, thienopyrazole ring, thienopyrazole ring, furanopyrazole ring, furanofuran ring, thienofuran ring, benzyl isocyanate Monovalent groups of five- or six-membered rings, such as azole rings, benzisothiazol rings, benzimazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, cyclophosphine rings, quinoxaline rings, phenanthridine rings, piridine rings, quinazoline rings, and quinazolineone rings, are monovalent groups of single or two- to four-membered fused rings.

[0116] Examples of linking groups include oxygen atoms or carbonyl groups. Since the triplet energy level can be increased by forming a non-conjugated structure with aromatic rings, a structure in which benzene rings are linked to each other using oxygen atoms or carbonyl groups can also be used. A structure in which the rings are directly linked without the aid of linking groups is preferred. Regarding Ar... 2 Ar 3 Ar4 Ar 6 Ar 7 Ar 8 Ar 11 Ar 12 Ar 36 Ar 37 Ar 38 The same applies to the linking groups in it.

[0117] Among these, considering the advantages of excellent charge transport and excellent durability, monovalent aromatic hydrocarbon groups are preferred, monovalent groups of benzene rings or fluorene rings are more preferred, phenyl or fluorenyl groups are even more preferred, fluorenyl groups are particularly preferred, and 2-fluorenyl groups are the most preferred.

[0118] In addition, considering its solubility in coating solvents, Ar 1 The preferred fluorenyl group is one substituted with an alkyl group having 1 to 24 carbon atoms, and particularly preferred is a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms. Furthermore, Ar... 1 Preferably, a 9-alkyl-2-fluorenyl group with an alkyl group substituted at the 9-position of the 2-fluorenyl group is used, and particularly preferably a 9,9-dialkyl-2-fluorenyl group with a disubstituted alkyl group is used. This is achieved by using Ar... 1 The fluorene group, which is substituted with an alkyl group, has improved solubility in the solvent and is therefore preferred.

[0119] As a monovalent group formed by directly or indirectly linking multiple groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups that may have substituents, a monovalent group formed by directly or indirectly linking multiple groups selected from the above-mentioned aromatic hydrocarbon groups and aromatic heterocyclic groups can be used.

[0120] Among them, by containing electron-withdrawing groups, the LUMO of the molecule is reduced, making it easier to withdraw electrons. In polymers containing aryl amines, from the viewpoint of improving the electronic durability of the molecule through LUMO and HOMO localization, structures represented by the formula (A1) described later are preferred, such as monovalent groups of benzene rings and carbazole rings, monovalent groups of triazine rings, etc.

[0121] As Ar 1 The substituents that may be present include groups selected from the substituent group Z described below or the crosslinking groups described below.

[0122] (Ar 1 (preferred range)

[0123] Ar 1 Preferably, it is represented by the following formula (A1).

[0124]

[0125] In formula (A1),

[0126] Ar 6 and Ar 7 Each can independently represent a divalent aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a divalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly connected by a linking group.

[0127] Ar 8 This indicates a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0128] Ar 9 Represents a hydrogen atom or a substituent.

[0129] -* indicates the bonding position with the nitrogen atom in formula (1), formula (2)-1 or formula (2)-2.

[0130] (Ar 6 Ar 7 )

[0131] As an aromatic hydrocarbon group, an aromatic hydrocarbon group with 6 to 60 carbon atoms is preferred. Specifically, examples include benzene rings, azurite rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. Divalent groups of six-membered rings such as cyclopentadiene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring, etc., or divalent groups of multiple such rings connected together.

[0132] As an aromatic heterocyclic group, an aromatic heterocyclic group with 3 to 60 carbon atoms is preferred. Specifically, examples include furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, and imidazole rings. Diazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrazole ring, thienopyrazole ring, thienopyrazole ring, furanopyrazole ring, furanofuran ring, thienofuran ring, benzyl isocyanate Divalent groups of single or two- to four-membered rings, such as azole rings, benzisothiazolium rings, benzimazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, borazine rings, quinoxaline rings, phenanthridine rings, piridine rings, quinazoline rings, and quinazolineone rings, or divalent groups of structures selected from these rings linked together.

[0133] As a divalent group selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, which are directly or indirectly linked by a linking group, the divalent group can be formed by linking multiple identical groups or by linking multiple different groups. As a divalent group selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, which are directly or indirectly linked by a linking group, multiple of the aforementioned aromatic hydrocarbon groups or aromatic heterocyclic groups can be linked directly or indirectly by a linking group.

[0134] Considering its excellent charge transport properties and superior durability, Ar 6 and Ar 7 Preferably, the divalent group is selected from one or more groups of unsubstituted divalent aromatic hydrocarbon groups and unsubstituted divalent aromatic heterocyclic groups, which are directly or indirectly bonded by a linking group. From the viewpoint of improving hole transport, as a group directly bonded to the nitrogen atom, an unsubstituted aromatic hydrocarbon group is preferred, a phenylene group or a divalent fluorene group without a substituent is more preferred, and a phenylene group without a substituent is particularly preferred.

[0135] Preferably, a fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure is bonded to a benzene ring directly bonded to a nitrogen atom. It is also preferred that one or more phenylene structures are further connected between the benzene ring directly bonded to a nitrogen atom and the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure.

[0136] Considering the localization of the LUMO at position 9 of the carbazole ring and the HOMO in the main chain, Ar 7 Preferably, the group can be formed by connecting 1 to 6 substituent divalent aromatic hydrocarbon groups, more preferably, the group can be formed by connecting 2 to 4 substituent divalent aromatic hydrocarbon groups, and even more preferably, the group can be formed by connecting 1 to 4 substituent benzene rings, and particularly preferably, the group can be formed by connecting 2 substituent benzene rings.

[0137] (Ar 8 )

[0138] Considering its excellent charge transport properties and superior durability, Ar 8 Preferably, the group can be formed by linking one or more monovalent aromatic hydrocarbon groups, which may have substituents. As mentioned above, from -Ar 7 -Ar 8From the perspective of LUMO distribution in the represented structure, the more connections, the better; however, from the perspective of charge transport and membrane stability, the fewer connections, the better. The number of connections is preferably 2 to 10, more preferably 6 or less, and particularly preferably 3 or less from the perspective of membrane stability.

[0139] Preferred aromatic hydrocarbon ring structures are benzene rings, naphthalene rings, anthracene rings, and fluorene rings, with benzene rings and fluorene rings being more preferred.

[0140] Preferred aromatic heterocyclic structures include benzothiophene rings, indole rings, carbazole rings, triazine rings, and quinazoline rings.

[0141] As a divalent group selected from aromatic hydrocarbon groups and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group, it is preferable to form a group consisting of 2 to 4 substituent benzene rings, or a group consisting of a substituent benzene ring linked to a substituent fluorene ring. From the viewpoint of LUMO extension, biphenylene rings consisting of 2 substituent benzene rings are particularly preferred.

[0142] As Ar 8 The substituents that can be present can be any of the substituents in the substituent group Z described later, or a combination thereof. From the viewpoint of suppressing LUMO extension, Ar... 8 The substituents that can be present are preferably other than N-carbazolyl, indolocarbazolyl, and indocarbazolyl, with phenyl, naphthyl, and fluorenyl being more preferred substituents.

[0143] Furthermore, it is preferable that the carbazole ring of formula (A1) has the structure shown below at position 9. From the viewpoint of further improving the LUMO distribution of the molecule, it is more preferable that the structure is selected from a-1~a-4, b-1~b-9, c-1~c-5, d-1~d-16, e1~e4 and f1~f4.

[0144] From the viewpoint of promoting LUMO expansion of the molecule by further incorporating electron-withdrawing groups, structures selected from a−1 to a−4, b−1 to b−6, d−1 to d−13, e1 to e4, and f1 to f4 are preferred. From the viewpoint of high triplet energy levels and the effect of confining the formed excitons within the luminescent layer, structures selected from a−1 to a−4, d−1 to d−13, e1 to e4, f1, and f4 are further preferred. Furthermore, these structures may contain substituents. It should be noted that in the following group of compounds, "−*" indicates a derivative with Ar. 7 The key, when there are multiple "-*", represents one of the keys.

[0145]

[0146]

[0147] In the above compound group, R 30 and R 31 Each can independently represent a hydrogen atom, or an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0148] As an alkyl, alkoxy, or aralkyl group, it can be used with R 1 ~R 8 The same alkyl, alkoxy, aralkyl, R 30 and R 31 The substituents that can be present can also be used with R 1 ~R 8 The same substituents.

[0149] (Ar 9 )

[0150] Ar 9 It represents a hydrogen atom or a substituent.

[0151] Ar 9 When the substituent is present, there are no particular limitations, but it is preferably an aromatic hydrocarbon group or an aromatic heterocyclic group that can have a substituent. As a preferred structure, it is similar to the Ar described above. 4 The same applies to the groups mentioned above.

[0152] Ar 9 When substituents are used, Ar is preferred from the viewpoint of improving durability. 9 It is bonded to the 3-position of carbazole. Considering ease of synthesis and charge transport, Ar... 9 Preferably, hydrogen atoms. From the viewpoint of improved durability and charge transport properties, Ar... 9 Preferably, it is an aromatic hydrocarbon group that may have substituents or an aromatic heterocyclic group that may have substituents, and more preferably, it is an aromatic hydrocarbon group that may have substituents.

[0153] As Ar 9 When the substituent is an aromatic hydrocarbon group or an aromatic heterocyclic group that can have a substituent, the preferred substituents are the same as those listed in the substituent group Z or the crosslinking groups described later, and these substituents can also have the same substituents. Furthermore, from the viewpoint of insolubility, Ar... 9 Preferably, it contains at least one crosslinking group as a substituent, as described later.

[0154] For the polymer of the present invention, as represented by formula (1), it preferably contains Ar. 1The structure can be either a benzene ring with substituents or a fluorene ring with substituents, or a structure represented by formula (A1), and is further preferably containing Ar. 1 The structures are those of a monovalent group of a fluorene ring that can have substituents and those represented by formula (A1).

[0155] (Ar 2 Ar 3 )

[0156] Ar 2 and Ar 3 Each can independently represent a divalent aromatic hydrocarbon group that may have substituents, or a divalent group formed by the direct or intermediate connection of multiple aromatic hydrocarbon groups that may have substituents along the main chain direction.

[0157] In addition, with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is not the nitrogen atom of the main chain amine, in Ar 2 The structure shown is a phenylene group without substituents, in which the nitrogen atom of the main chain amine is bonded.

[0158] with Ar 3 Adjacent bonded repeating units with Ar 3 When the bonded atom is the nitrogen atom of the main chain amine, it is preferable to satisfy at least one of the following conditions, namely, in Ar 2 The structure shown is a phenylene group without substituents bonded to the nitrogen atom of the main chain amine, and in Ar... 3 The structure represented by Ar 3 The structure in the adjacent-bonded repeating unit that is directly bonded to the nitrogen atom of the main chain amine is a phenylene without substituents.

[0159] As a divalent aromatic hydrocarbon group, an aromatic hydrocarbon group with 6 to 60 carbon atoms is preferred. Specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. Monocyclic or divalent groups of six-membered rings such as triphenylene ring, acenaphthene ring, fluoranthene ring, and fluorene ring.

[0160] In terms of excellent charge transport properties and excellent durability, the preferred divalent group is one or more groups of a divalent aromatic hydrocarbon group that are directly or indirectly bonded by a linking group.

[0161] From the perspective of improving hole transportability, as an Ar 2Preferably, the aromatic hydrocarbon group is unsubstituted, more preferably, it is an unsubstituted phenylene or an unsubstituted divalent fluorene group, and particularly preferably, it is an unsubstituted phenylene. Preferably, a fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure is bonded to the phenylene ring directly bonded to the nitrogen atom, and even more preferably, one or more phenylene groups are further linked between the phenylene ring directly bonded to the nitrogen atom and the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure.

[0162] As a divalent group formed by the direct or intermediate linkage of multiple aromatic hydrocarbon groups that may have substituents, it can be a group formed by the linkage of multiple identical groups or multiple different groups.

[0163] As a divalent group formed by the direct or intermediate linkage of multiple aromatic hydrocarbon groups that may have substituents, for example, biphenyl and terphenyl.

[0164] From the perspective of charge transport and durability, multiple aromatic hydrocarbon groups that may have substituents are preferably directly bonded together without a linking group.

[0165] As Ar 2 and Ar 3 The substituents that can be present can be any of those in the substituent group Z described later. Ar 2 and Ar 3 The substituents that can be present are particularly preferably straight-chain, branched, or cyclic alkyl groups. The number of carbon atoms in the alkyl group is not particularly limited, but to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more, more preferably 4 or more, more preferably 12 or less, and even more preferably 8 or less. The alkyl group is particularly preferably hexyl. 2 and Ar 3 The substituents that can be present can be used in combination.

[0166] Substituents that can be present as straight-chain, branched, or cyclic alkyl groups can be selected from the substituent group Z described below, with hydrogen atoms being particularly preferred from a stability point of view.

[0167] Ar 2 and Ar 3 When a ring adjacent to a nitrogen atom is present, the HOMO of the molecule is reduced by ensuring that at least one of the rings is free of substituents, making it easier to inject charge into the luminescent layer. 2 and Ar 3 When the ring is adjacent to a nitrogen atom, it is particularly preferred that the ring is entirely free of substituents.

[0168] (X)

[0169] X represents -C(R)7 (R) 8 )-、-N(R 9 ) - or - C(R 10 (R) 11 )-C(R 12 (R) 13 )-.

[0170] X is preferably -C(R) 7 (R) 8 ) - or - C(R 10 (R) 11 )-C(R 12 (R) 13 The optimal choice is -C(R) - 7 (R) 8 )-.

[0171] (R 1 ~R 8 )

[0172] R 1 ~R 8 Each can independently represent hydrogen, an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0173] Through R 1 ~R 8 Each can be an independent hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents, which can cause the main chain to twist.

[0174] As an alkyl group, examples include straight-chain, branched, or cyclic alkyl groups with 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl, and dodecyl.

[0175] As an alkoxy group, since it tends to improve the solubility of the polymer, alkoxy groups with 1 to 24 carbon atoms are preferred. Specifically, examples include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, and hexoxy.

[0176] Aryl groups are not particularly limited, but since they tend to improve the solubility of polymers, aryl groups with 5 to 60 carbon atoms are preferred, aryl groups with 40 or fewer carbon atoms are more preferred, aryl groups with 7 or more carbon atoms are even more preferred, aryl groups with 10 or more carbon atoms are particularly preferred, and aryl groups with 12 or more carbon atoms are especially preferred.

[0177] Specifically, examples 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.

[0178] R 1 ~R 8 When R is not a hydrogen atom, 1 ~R 8 Preferably, the alkyl group can be a straight-chain, branched, or cyclic alkyl group that may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 to 6, more preferably 3 or less, and even more preferably methyl or ethyl.

[0179] R other than hydrogen atoms 1 ~R 8 When multiple atoms are present, the charge can be evenly distributed around the nitrogen atom. Furthermore, due to its ease of synthesis, R atoms other than hydrogen atoms... 1 ~R 8 When multiple groups are present, they are preferably the same group.

[0180] Additionally, R 1 R 2 R 5 R 6 At least one of them is an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or an aralkyl group that may have a substituent.

[0181] From the perspective of forming a torsion, R 1 and R 2 common or R 5 and R 6 Commonly preferred are alkyl groups that can have substituents, alkoxy groups that can have substituents, or aralkyl groups that can have substituents, especially R from a synthetic point of view. 1 and R 2 Each of the following is particularly preferred independently: an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or an aralkyl group that may have a substituent.

[0182] From the perspective of achieving the best durability, the optimal choice is R. 1 and R 2Each alkyl group is independently alkyl. From the perspective of achieving excellent charge transport without causing the main chain to twist without distancing the polymers in the membrane, the alkyl group preferably has 8 or fewer carbon atoms, more preferably 6 or fewer. When the alkyl group has 4 or fewer carbon atoms, the polymers in the membrane become sufficiently close together; to further improve charge transport, a methyl group with 1 carbon atom is even more preferred.

[0183] As R 1 ~R 8 The substituents that may be present are preferably any one or a combination thereof, from the substituent group Z described later, an aralkyl group having 7 to 40 carbon atoms, or a heterocyclic aralkyl group having 4 to 37 carbon atoms.

[0184] As R 1 ~R 8 The substituents that can be present, from the perspective of durability, are preferably alkyl groups with 1 to 24 carbon atoms, aralkyl groups with 7 to 40 carbon atoms, heterocyclic aralkyl groups with 3 to 37 carbon atoms, arylamino groups with 10 to 24 carbon atoms, aromatic hydrocarbon groups with 6 to 36 carbon atoms, or aromatic heterocyclic groups with 3 to 36 carbon atoms.

[0185] More preferably, alkyl groups having 1 to 12 carbon atoms, aralkyl groups having 7 to 30 carbon atoms, heterocyclic aralkyl groups having 3 to 27 carbon atoms, aromatic hydrocarbon groups having 6 to 24 carbon atoms, or aromatic heterocyclic groups having 3 to 24 carbon atoms.

[0186] Further preferred are aryl groups with 6 to 24 carbon atoms.

[0187] As R 1 ~R 8 The substituents that may be present are preferably aromatic hydrocarbon groups with 6 to 24 carbon atoms or aromatic heterocyclic groups with 3 to 24 carbon atoms, and more preferably phenyl, naphthyl, fluorenyl, carbazolyl, indolocarbazolyl, indobenzocarbazolyl, or indobenzofluorenyl.

[0188] Furthermore, from a synthetic point of view, R 1 ~R 8 Preferably, it is hydrogen, an unsubstituted alkyl group, an unsubstituted alkoxy group, or an unsubstituted aralkyl group.

[0189] (R 9 ~R 13 )

[0190] R 9 ~R 13 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an alkoxy group that may have substituents, an aralkyl group that may have substituents, or an aromatic hydrocarbon group that may have substituents.

[0191] As an alkyl, alkoxy, or aralkyl group, it can be used with R 1 ~R 8 The same alkyl, alkoxy, aralkyl, R 9 ~R 13 The substituents that can be present can also be used with R 1 ~R 8 The same substituents.

[0192] As an aromatic hydrocarbon group, an aromatic hydrocarbon group with 6 to 60 carbon atoms is preferred. Specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. Monovalent groups of six-membered rings, such as benzene rings, triphenylene rings, acenaphthene rings, fluoranthene rings, and fluorene rings, are preferred. From a durability point of view, monovalent groups of benzene rings and fluorene rings are particularly preferred.

[0193] When the polymer of the present invention is formed into a film and then further coated to form other layers, from the viewpoint of increased insolubility in solvent, X possesses R 7 ~R 13 The substituents that can be further included are preferably crosslinking groups, as described later. Among these, R is preferred because it does not readily impede charge transport. 7 R 8 R 10 ~R 13 Either of them preferably has the crosslinking group described later as a further substituent, R 7 and R 8 At least one of them is further preferably having a crosslinking group as a further substituent, as described later.

[0194] It should be noted that X is -C(R) 7 (R) 8 ) - when and R 5 and / or R 6 When R is not a hydrogen atom, 7 With R 5 R 7 With R 6 R 8 With R 5 and R 8 With R 6 They do not combine to form a ring under any circumstances.

[0195] In addition, the two structures in the main chain of the polymer that are bonded to the nitrogen atom of the main chain amine in formula (1) are preferably phenylene oxides that can have substituents.

[0196] <Preferred Repeating Unit Structure>

[0197] The repeating unit represented by the above formula (1) is more preferably represented by the following formula (2)-1 or the following formula (2)-2.

[0198]

[0199] In equation (2)-1 or equation (2)-2,

[0200] Ar 1 R 1 ~R 6 X is defined in the same way as in equation (1) above.

[0201] R 20 ~R 23 Each independently with R 1 same,

[0202] g, h, and i each independently represent integers from 1 to 3.

[0203] j and k each independently represent integers from 1 to 2.

[0204] In addition, the structure in the main chain of the polymer that is directly bonded to the nitrogen atom of the main chain amine in formula (2)-1 or formula (2)-2 is preferably a phenylene without substituents.

[0205] (g, h, i, j, and k)

[0206] g and i are each an independent integer from 1 to 3.

[0207] Furthermore, g+i is preferably 2 or more. In addition, g and i are each preferably 2 or less independently, and from the viewpoint of not easily hindering charge transport, g and i are further preferably 1.

[0208] h is an integer from 1 to 3. Furthermore, h is preferably 2 or less, and from the viewpoint of not easily hindering charge transport, h is further preferably 1.

[0209] j and k are each an independent integer from 1 to 2.

[0210] Furthermore, j+k is preferably 2 or more. In addition, j and k are each preferably 2 or less independently, and from the viewpoint of not easily hindering charge transport, j and k are further preferably 1.

[0211] When h, j, and k are all 1 or h, j, and k are all 2, R 20 =R 23 And R 21 =R 22 This makes the structure symmetrical, and therefore preferred.

[0212] From the viewpoint of element durability or low voltage reduction when used in organic electroluminescent elements, it is preferable to include repeating units represented by formula (2)-1 or formula (2)-2.

[0213] <Preferred Repeating Unit Structure and Partial Structure>

[0214] The two structures constituting the main chain of the polymer of the present invention and directly bonded to the nitrogen atom of the main chain amine in formula (1) are further preferably phenylene oxides that may have substituents.

[0215] Here, in the structure that constitutes the main chain of the polymer, the two structures of the nitrogen atom of the main chain amine directly bonded to the main chain in formula (1) are both phenylenes that can have substituents, which refers to the following two cases (a) and (b).

[0216] (a) The case where multiple repeating units are connected and repeated, as represented by equation (1) above.

[0217] (b) The case where the N of the repeating unit represented by the above formula (1) is bonded to a structure other than that in the above formula (1).

[0218] Here, in case (a), the polymer of the present invention has repeating units represented by the following formulas (1)-2, and in case (b), the polymer of the present invention has a partial structure represented by the following formulas (1)-3.

[0219]

[0220]

[0221] (in equation (1)-2,

[0222] Ar 1 Ar 2 Ar 3 R 1 ~R 6 The expressions (1) represent Ar, X, and n. 1 Ar 2 Ar 3 R 1 ~R 6 X, n

[0223] n62 and n63 are both 4.

[0224] Multiple R 62 Each independently of R in equation (1) 1 The same, that is, representing hydrogen, alkyl groups that may have substituents, alkoxy groups that may have substituents, or aralkyl groups that may have substituents.

[0225] Multiple R 63Each independently of R in equation (1) 1 The same, that is, representing hydrogen, alkyl groups that may have substituents, alkoxy groups that may have substituents, or aralkyl groups that may have substituents.

[0226] Among them, Ar 2 For equation (1)-4 and Ar 3 For equation (1)-5,

[0227] In equation (1)-4,

[0228] * indicates the key in the main chain.

[0229] Ar 32 For Ar from the above equation (1) 2 Remove Ar 2 The remaining structure, which includes nitrogen atoms bonded to the main chain of formula (1) and may have substituents such as phenylene, wherein Ar 2 When the phenylene group can have substituents, it indicates direct bonding.

[0230] In equation (1)-5,

[0231] * indicates the key in the main chain.

[0232] Ar 33 For Ar from the above equation (1) 3 Remove Ar 3 The remaining structure, which may have substituents, is directly bonded to the adjacent repeating unit of the repeating unit represented by formula (1), wherein Ar 3 When the phenylene group can have substituents, it indicates direct bonding.

[0233] In equation (1)-3,

[0234] Q indicates that it can have R 62 The phenylene is part or all of the structure of the N-repeating unit represented by formula (1) that is directly bonded to it.

[0235] Ar 1 Ar 2 Ar 32 R 1 ~R 6 R 62 X, n, n62 and Ar in equation (1)-2 1 Ar 2 Ar 32 R 1 ~R 6 R 62 X, n, and n62 are the same.

[0236] Ar3 Ar in equation (1) 3 same,

[0237] n61 is 4.

[0238] Multiple R 61 Each independently of R in equation (1) 1 The same, that is, representing hydrogen, alkyl groups that may have substituents, alkoxy groups that may have substituents, or aralkyl groups that may have substituents.

[0239] Among them, Ar 2 (Formula (1) - 4)

[0240] Ar in equation (1)-3 3 The preferred structure is the one represented by formula (1)-5.

[0241] When the polymer of the present invention is a polymer having repeating units represented by the above formula (1)-2, the repeating units represented by the above formula (1)-2 are preferably the following formula (1)-2-2, and more preferably the following formula (1)-2-3.

[0242]

[0243] Equation (1)-2-2 indicates that there are 4 R values ​​in the above equation (1)-2. 62 Two of them are hydrogen and there are four Rs. 63 Two of them are hydrogen.

[0244] The two R atoms bonded to the phenylene 62 At least one of them is not hydrogen, and is bonded to the two R atoms of the phenylene group. 63 At least one of them is not hydrogen.

[0245]

[0246] Equation (1)-2-3 indicates that there are 4 R values ​​in the above equation (1)-2. 62 And there are 4 R 63 It is all hydrogen.

[0247] When the polymer of the present invention has a partial structure represented by the above formula (1)-3, the partial structure represented by the above formula (1)-3 is preferably the following formula (1)-3-2, and more preferably the following formula (1)-3-3.

[0248]

[0249] Equation (1)-3-2 indicates that there are 4 R values ​​in the above equation (1)-3. 61 Two of them are hydrogen and there are four Rs. 62Two of them are hydrogen.

[0250] The two R atoms bonded to the phenylene 61 At least one of them is not hydrogen and is bonded to the two R atoms of the phenylene group. 62 At least one of them is not hydrogen.

[0251] Ar in equation (1)-3-2 3 The preferred structure is the one represented by formula (1)-5.

[0252]

[0253] Equation (1)-3-3 indicates that there are 4 R values ​​in the above equation (1)-3. 61 And there are 4 R 62 It is all hydrogen.

[0254] Ar in equation (1)-3-3 3 The preferred structure is the one represented by formula (1)-5.

[0255] Furthermore, Ar, as represented by the above equation (1)-4 2 The preferred structure is represented by formula (1)-4-2 or formula (1)-4-3.

[0256]

[0257] In equations (1)-4-2 and (1)-4-3,

[0258] R 20 R 22 Each independently relates to R in the above equation (2)-2 20 R 22 same,

[0259] g is the same as g in equation (2)-1 above and represents an integer from 1 to 3. The preferred value and the rationale are also the same as g in equation (2)-1 above.

[0260] j is the same as j in the above formula (2)-2 and represents an integer from 1 to 2. The preferred value and the reason are also the same as j in the above formula (2)-2.

[0261] Furthermore, Ar, as represented by the above equation (1)-5 3 The preferred structure is represented by formula (1)-5-2 or formula (1)-5-3.

[0262]

[0263] In equations (1)-5-2 and (1)-5-3,

[0264] R 23 R 24Each independently relates to R in the above equation (2)-2 23 R 24 same,

[0265] i is the same as i in equation (2)-1 above and represents an integer from 1 to 3. The preferred value and the rationale are also the same as i in equation (2)-1 above.

[0266] k is the same as k in the above formula (2)-2 and represents an integer from 1 to 2. The preferred value and the reason are also the same as k in the above formula (2)-2.

[0267] In the partial structures of the structures represented by formulas (1)-2, (1)-3, (1)-4, (1)-5, (1)-2-2, (1)-2-3, (1)-3-2, (1)-3-3, (1)-4, (1)-4-2, (1)-4-3, (1)-5, (1)-5-2, and (1)-5-3, when no substituent is present, the substituent group Z described later can be selected. Preferably, the structure does not have any of the substituents that can be present.

[0268] (Substitute basis set Z)

[0269] As a substitute for the basis set Z, the following structures can be cited.

[0270] For example, alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl are straight-chain, branched, or cyclic alkyl groups with a carbon number of 1 or more, preferably 4 or more, usually 24 or less, and preferably 12 or less.

[0271] For example, vinyl groups are alkenyl groups, which typically have 2 or more carbon atoms, typically 24 or less, and preferably 12 or less;

[0272] For example, acetylene groups, etc., typically have 2 or more carbon atoms, typically 24 or less, and preferably 12 or less;

[0273] For example, alkoxy groups such as methoxy and ethoxy groups typically have 1 or more carbon atoms, typically 24 or less, and preferably 12 or less;

[0274] For example, aryloxy or heteroaryloxy compounds such as phenoxy, naphthoxy, and pyridinoxy typically have 4 or more carbon atoms, preferably 5 or more, typically 36 or less, and preferably 24 or less;

[0275] For example, alkoxycarbonyl groups, such as methoxycarbonyl and ethoxycarbonyl, typically have 2 or more carbon atoms, typically 24 or less, and preferably 12 or less;

[0276] For example, dialkylamino, dimethylamino, etc., are dialkylamino groups with a carbon number of 2 or more, usually 24 or less, and preferably 12 or less;

[0277] For example, diarylamino groups such as diphenylamino, xylylamino, and N-carbazole group typically have 10 or more carbon atoms, preferably 12 or more, typically 36 or less, and preferably 24 or less.

[0278] For example, arylalkylamino compounds, such as phenylmethylamino, typically have 7 or more carbon atoms, typically 36 or less, and preferably 24 or less;

[0279] For example, acyl groups such as acetyl and benzoyl have a carbon number of 2 or more, usually 24 or less, and preferably 12 or less;

[0280] For example, halogen atoms such as fluorine and chlorine atoms;

[0281] For example, trifluoromethyl and other haloalkyl groups typically have 1 or more carbon atoms, typically 12 or less, and preferably 6 or less;

[0282] For example, alkylthio groups such as methylthio and ethylthio typically have 1 or more carbon atoms, typically 24 or less, and preferably 12 or less;

[0283] For example, arylthio groups such as phenylthio, naphthio, and pyridinethio typically have 4 or more carbon atoms, preferably 5 or more, typically 36 or less, and preferably 24 or less;

[0284] For example, silyl groups such as trimethylsilyl and triphenylsilyl typically have 2 or more carbon atoms, preferably 3 or more, typically 36 or less, and preferably 24 or less;

[0285] For example, siloxy groups such as trimethylsiloxy and triphenylsiloxy typically have 2 or more carbon atoms, preferably 3 or more, typically 36 or less, and preferably 24 or less;

[0286] Cyano;

[0287] For example, aromatic hydrocarbon groups such as phenyl and naphthyl typically have 6 or more carbon atoms, typically 36 or less, and preferably 24 or less;

[0288] For example, aromatic heterocyclic groups such as thiophene group and pyridyl group have a carbon number of 3 or more, preferably 4 or more, usually 36 or less, and preferably 24 or less.

[0289] Among the substituent group Z described above, alkyl, alkoxy, aromatic hydrocarbon, and aromatic heterocyclic groups are preferred. From the viewpoint of charge transport or ease of synthesis, Ar... 1 ~Ar 3 R1 ~R 13 R 20 ~R 23 Further preferred options include those without substituents.

[0290] Furthermore, each substituent in the aforementioned substituent group Z may further have substituents. Examples of such substituents include the same substituents as those in the aforementioned substituent group (substituent group Z) or crosslinking groups described later. Preferably, each substituent in the aforementioned substituent group Z does not have further substituents, or has an alkyl group with 6 or fewer carbon atoms, an alkoxy group with 6 or fewer carbon atoms, a phenyl group, or a crosslinking group described later. From the viewpoint of charge transport, it is more preferable that each substituent in the aforementioned substituent group Z does not have further substituents.

[0291] [Terminal group]

[0292] In this invention, the terminator refers to the structure at the end of the polymer formed by a capping agent used at the end of polymer polymerization. The terminators of the polymers of this invention are typically hydrocarbon groups. From the viewpoint of charge transport, the number of carbon atoms in the hydrocarbon group is preferably 1 to 60, more preferably 1 to 40, and even more preferably 1 to 30.

[0293] The following are some of the preferred examples:

[0294] For example, alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl are straight-chain, branched, or cyclic alkyl groups with a carbon number of 1 or more, preferably 4 or more, usually 24 or less, and preferably 12 or less.

[0295] For example, vinyl groups are alkenyl groups that typically have 2 or more carbon atoms, typically 24 or less, and preferably 12 or less.

[0296] For example, acetylene groups, etc., typically have 2 or more carbon atoms, typically 24 or less, and preferably 12 or less;

[0297] For example, aromatic hydrocarbon cyclic groups such as phenyl and naphthyl typically have 6 or more carbon atoms, typically 36 or less, and preferably 24 or less.

[0298] These hydrocarbon groups may further have substituents, preferably alkyl or aromatic hydrocarbon groups, and when multiple substituents are present, they can bond with each other to form a ring.

[0299] From the viewpoint of charge transport and durability, these may further have substituents, preferably alkyl or aromatic hydrocarbon groups, and more preferably aromatic hydrocarbon groups.

[0300] [Soluble groups]

[0301] In order to exhibit solubility in solvents, the polymers of the present invention preferably have soluble groups. The soluble groups in the present invention are straight-chain or branched alkyl or alkylene groups having 3 to 24 carbon atoms, preferably 12 or less.

[0302] Preferably, the alkyl, alkoxy, or aralkyl group is used, for example, n-propyl, 2-propyl, n-butyl, isobutyl, etc. More preferably, it is n-hexyl or n-octyl. The soluble group may have substituents.

[0303] The above R 1 ~R 13 and R 20 ~R 23 When one or more of the components are of these structures, these groups are considered soluble groups. Furthermore, when the substituents in this invention satisfy the above-mentioned conditions for soluble groups, these substituents are considered soluble groups.

[0304] (Number of soluble groups)

[0305] From the perspective of easily obtaining polymer solutions suitable for wet film formation, the polymer of the present invention should have as many soluble groups as possible. On the other hand, from the perspective of minimizing the reduction in film thickness due to layer dissolution in the solvent when forming other layers on top of the film layer using wet film formation, the less the reduction, the better.

[0306] The number of soluble groups in the polymer of the present invention can be expressed by the number of moles per 1g of polymer.

[0307] When the number of soluble groups in the polymer of the present invention is expressed in moles per 1g of polymer, it is generally 4.0 mmol or less, preferably 3.0 mmol or less, more preferably 2.0 mmol or less, and generally 0.1 mmol or more, preferably 0.5 mmol or more, relative to 1g of polymer.

[0308] When the number of soluble groups is within the above-mentioned range, the polymer readily dissolves in the solvent, making it easy to obtain a composition containing a polymer suitable for wet film formation. Furthermore, due to the appropriate density of soluble groups, the polymer exhibits sufficient low solubility in organic solvents after drying in the solvent. Therefore, a multilayered structure can be formed using the wet film formation method.

[0309] Here, the number of soluble groups per 1g of polymer can be calculated from the polymer after removing its terminal groups, the molar ratio of the monomers fed during synthesis, and the structural formula.

[0310] When describing the case of polymer 1 synthesized in Example 1 described below, the average molecular weight of the repeating units after removing the terminal groups in polymer 1 is 682, and the average number of hexyl groups, which are soluble groups, is 0.9 per repeating unit. When calculated by simple proportions, the number of soluble groups per gram of molecular weight is 1.31 mmol.

[0311]

[0312] [Crosslinking groups]

[0313] The polymers of the present invention can have crosslinking groups. The crosslinking groups in the polymers of the present invention can be present in the repeating units represented by formula (1), or in other repeating units different from the repeating units represented by formula (1). In particular, in Ar, which serves as a side chain... 1 The component containing crosslinking groups is preferred because it facilitates crosslinking reactions.

[0314] The polymers of this invention have crosslinking groups, which enable a significant difference in solubility in organic solvents before and after a reaction (insoluble reaction) caused by heat and / or active energy rays.

[0315] Crosslinking groups are groups that react with groups that make up other molecules in their vicinity, forming new chemical bonds, through irradiation with heat and / or active energy rays.

[0316] In this case, the reacting group can be the same as the crosslinking group or a different group.

[0317] As a crosslinking group, it is preferably a group comprising a cyclobutene ring condensed with an aromatic ring, an alkenyl group bonded to an aromatic ring, and more preferably a group selected from the following crosslinking group group T. The crosslinking group is preferably further substituted with substituent group Z.

[0318] (Crosslinked group group T)

[0319] The crosslinking group group T has the structure shown below.

[0320]

[0321] In the above crosslinking group group T, R 24 ~R 26 Each can independently represent a hydrogen atom or an alkyl group. R 27 ~R 29 Each can independently represent an alkyl or alkoxy group. Ar 21 Ar 22This indicates an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents. p represents an integer from 1 to 4, q represents an integer from 1 to 5, and r represents an integer from 1 to 7.

[0322] When p is 2 or higher, multiple R 27 They can be the same or different, adjacent R 27 They can bond together to form a ring.

[0323] When q is 2 or more, multiple R 28 They can be the same or different, replacing the R adjacent to the aromatic ring. 28 They can bond together to form a ring.

[0324] When r is 2 or higher, multiple R 29 They can be the same or different.

[0325] As R 24 ~R 29 Alkyl groups, including straight-chain or branched chain alkyl groups having 6 or fewer carbon atoms. Examples include methyl, ethyl, n-propyl, 2-propyl, n-butyl, isobutyl, etc. Methyl or ethyl groups are more preferred. (By R...) 24 ~R 29 The alkyl group has 6 or fewer carbon atoms, so the crosslinking reaction is not hindered by space, and there is a tendency for the film to become insoluble.

[0326] As R 27 ~R 29 The alkoxy group can be categorized as a straight-chain or branched chain alkoxy group having 6 or fewer carbon atoms, such as methoxy, ethoxy, n-propoxy, 2-propoxy, n-butoxy, etc. More preferably, it is methoxy or ethoxy. If R 27 ~R 29 If the number of carbon atoms in the alkoxy group is less than 6, the cross-linking reaction will not be hindered by space, and there is a tendency for the membrane to become insoluble.

[0327] In Ar 21 Ar 22 Among them, aromatic hydrocarbon groups that can have substituents include monocyclic or two- to five-membered rings such as benzene rings or naphthalene rings with one free valence atom. Benzene rings with one free valence atom are particularly preferred.

[0328] Additionally, in Ar 21 Ar 22In this context, the aromatic heterocyclic group that can have substituents is preferably an aromatic heterocyclic group with 3 to 60 carbon atoms having one free valence atom. Specifically, examples include monovalent groups of five- to six-membered rings such as furan ring, benzofuran ring, thiophene ring, benzothiophene ring, imidazole ring, indole ring, carbazole ring, benzimidazole ring, pyridine ring, pyrimidine ring, triazine ring, isoquinoline ring, quinoxaline ring, phenanthridine ring, and quinazoline ring, or monovalent groups formed by connecting multiple of these structures. Benzofuran ring, benzothiophene ring, carbazole ring, and triazine ring are particularly preferred.

[0329] Ar 22 It can be a group formed by bonding two or more aromatic hydrocarbon groups that can have substituents. Examples of such groups include diphenylene and terphenylene, with 4,4'-diphenylene being preferred.

[0330] Ar 21 Ar 22 It can have the same substituents as the aforementioned substituent group Z.

[0331] As a crosslinking group, in order to further improve the electrochemical stability of the device, groups that undergo cycloaddition reactions, such as aryl vinyl carbonyl groups like cinnamyl, benzocyclobutene rings with monovalent free atomic valence, and 1,2-dihydrocyclobutene[a]naphthalene rings with monovalent free atomic valence, are preferred.

[0332] Furthermore, regarding the crosslinking groups, those comprising a cyclobutene ring having a monovalent free valence and a 1,2-dihydrocyclobutene[a]naphthyl ring having a monovalent free valence are preferred for the sake of particularly stable crosslinked structure. More preferably, these groups include a benzocyclobutene ring or a 1,2-dihydrocyclobutene[a]naphthyl ring having a monovalent free valence. Groups comprising a 1,2-dihydrocyclobutene[a]naphthyl ring having a monovalent free valence are particularly preferred for the sake of low crosslinking reaction temperature.

[0333] (Number of cross-linking groups)

[0334] The polymer of the present invention has as many crosslinking groups as possible, which makes it sufficiently insoluble through crosslinking and facilitates the formation of other layers on it using wet film-forming methods. On the other hand, the fewer crosslinking groups, the better, as it makes the formed layer less prone to cracking, less likely to leave unreacted crosslinking groups, and facilitates a long lifespan for the organic electroluminescent element.

[0335] The number of crosslinking groups present in one polymer chain in the polymer of the present invention is preferably 1 or more, more preferably 2 or more, and even more preferably 200 or less, more preferably 100 or less.

[0336] Furthermore, the number of crosslinking groups in the polymer of the present invention can be expressed as the number of groups relative to the molecular weight of the polymer, 1000.

[0337] When the number of crosslinking groups in the polymer of the present invention is expressed as the number of groups relative to the molecular weight 1000 of the polymer, it is generally 3.0 or less relative to the molecular weight 1000, preferably 2.0 or less, more preferably 1.0 or less, and generally 0.01 or more, preferably 0.05 or more.

[0338] When the number of cross-linking groups is within the above range, cracks are less likely to occur, and a flat film is easily obtained.

[0339] In addition, due to the appropriate crosslinking density, there are fewer unreacted crosslinking groups remaining in the layer after the crosslinking reaction, which is less likely to affect the lifespan of the obtained components.

[0340] Furthermore, due to the high solubility of the cross-linked material in organic solvents, it is easy to form multilayered structures using wet film-forming methods.

[0341] [The amount of repeating units]

[0342] In the polymer of the present invention, the content of the repeating unit represented by formula (1) is not particularly limited, but generally the polymer contains 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, and particularly preferably 30 mol% or more. The repeating unit of the polymer of the present invention may consist only of the repeating unit represented by formula (1), but for the purpose of balancing many performance aspects when manufacturing organic electroluminescent devices, it may also have other repeating units different from formula (1). In this case, the content of the repeating unit represented by formula (1) in the polymer is generally 50 mol% or more, preferably 60 mol% or more.

[0343] [Other preferred repeating units that may be included]

[0344] The polymer of the present invention preferably further contains at least one of the repeating units represented by formula (3)-1 and the repeating units represented by formula (3)-2.

[0345]

[0346] In equation (3)-1 or equation (3)-2,

[0347] Ar 4 Each repeating unit independently represents a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0348] X 30 Represents -C(R) 37 (R) 38 )-、-N(R 39 ) - or - C(R 40 (R) 41 )-C(R 42 (R) 43 )-,

[0349] R 33 R 34 R 37 R 38 R 120 ~R 123 Each can independently represent hydrogen, an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents.

[0350] R 39 ~R 43 Each can independently represent hydrogen, an alkyl group that may have substituents, an alkoxy group that may have substituents, an aralkyl group that may have substituents, or an aromatic hydrocarbon group that may have substituents.

[0351] g 3 h 3 i 3 Each can independently represent an integer from 1 to 3.

[0352] j 3 k 3 Each can independently represent an integer from 1 to 2.

[0353] R 33 R 34 R 37 R 38 R 120 ~R 123 The alkyl, alkoxy, and aralkyl groups in R can be used with R 1 ~R 8 The same alkyl, alkoxy, and aralkyl groups.

[0354] R 39 ~R 43 The alkyl, alkoxy, aralkyl, and aromatic hydrocarbon groups in R can be used with R 9 ~R 13 The same alkyl, alkoxy, aralkyl, and aromatic hydrocarbon groups.

[0355] (Ar 4 )

[0356] Ar 4Each repeating unit independently represents a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by directly or indirectly connecting multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0357] Ar in the polymer of the present invention 4 When multiple Ar exist, multiple Ar 4 They can be the same or different.

[0358] As an aromatic hydrocarbon group, an aromatic hydrocarbon group with 6 to 60 carbon atoms is preferred. Specifically, examples include benzene rings, azurite rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. Monovalent groups of six-membered rings such as triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring, etc., or monovalent groups formed by connecting multiple of them in a structure selected from these.

[0359] As an aromatic heterocyclic group, an aromatic heterocyclic group with 3 to 60 carbon atoms is preferred. Specifically, examples include furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, and imidazole rings. Diazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrazole ring, thienopyrazole ring, thienopyrazole ring, furanopyrazole ring, furanofuran ring, thienofuran ring, benzyl isocyanate Monovalent groups of five- to six-membered rings, such as azole rings, benzisothiazol rings, benzimazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, borazine rings, quinoxaline rings, phenanthridine rings, piridine rings, quinazoline rings, and quinazolineone rings, or monovalent groups of multiple such rings connected together.

[0360] Considering its excellent charge transport properties and superior durability, Ar 4 Preferably, the substituted aromatic hydrocarbon group may be used, more preferably a monovalent group of a benzene ring or fluorene ring may be used, i.e., a substituted phenyl or fluorenyl group may be used, further preferably a substituted fluorenyl group may be used, and particularly preferably a substituted 2-fluorenyl group may be used.

[0361] As Ar 4 The aromatic hydrocarbon group and aromatic heterocyclic group may have substituents, and there are no particular limitations as long as they do not significantly reduce the properties of the polymer of the present invention. Groups selected from the above-mentioned substituent group Z or the above-mentioned crosslinking groups are preferred, preferably alkyl, alkoxy, aromatic hydrocarbon group, aromatic heterocyclic group or the above-mentioned crosslinking group, and more preferably alkyl.

[0362] Considering its solubility in coating solvents, Ar 4 The preferred fluorenyl group is one substituted with an alkyl group having 1 to 24 carbon atoms, and the most preferred fluorenyl group is one substituted with an alkyl group having 4 to 12 carbon atoms. Further preferred is a 9-alkyl-2-fluorenyl group with an alkyl group substituted at the 9-position of the 2-fluorenyl group, and the most preferred is a 9,9-dialkyl-2-fluorenyl group with a disubstituted alkyl group.

[0363] via Ar 4 Fluorene groups with at least one alkyl substituted at the 9' and 9' positions tend to exhibit improved solubility in solvents and increased durability of the fluorene ring. Furthermore, through Ar... 4 The presence of alkyl-substituted fluorene groups at both the 9' and 9' positions tends to further enhance solubility in solvents and the durability of the fluorene ring.

[0364] Furthermore, Ar is preferred because its insolubility in solvent increases during layering and coating after film formation. 4 It contains the aforementioned cross-linking groups.

[0365] From the viewpoint of insolubility, the polymer of the present invention preferably comprises repeating units represented by formulas (3)-1 and (3)-2 containing at least one of the aforementioned crosslinking groups as further substituents, preferably in Ar 4 The aromatic hydrocarbon group or aromatic heterocyclic group may have a substituent on which the crosslinking group is further substituted.

[0366] From the viewpoint of the durability or low voltage of the element when used in an organic electroluminescent element, the polymer of the present invention preferably further comprises repeating units represented by formula (3)-1.

[0367] (Ar 4 (preferred range)

[0368] Ar 4 The preferred expression is represented by the following formula (A2).

[0369]

[0370] In formula (A2),

[0371] Ar 36 and Ar 37 Each can independently represent a divalent aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a divalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly connected by a linking group.

[0372] Ar 38This indicates a monovalent aromatic hydrocarbon group that may have substituents, a monovalent aromatic heterocyclic group that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, either directly or indirectly linked by a linking group.

[0373] Ar 39 Represents a hydrogen atom or a substituent.

[0374] -* indicates the bonding position with the nitrogen atom in formula (3)-1 or formula (3)-2 above.

[0375] Ar 36 ~Ar 39 Specific examples and preferred ranges with Ar 6 ~Ar 9 same.

[0376] [Molecular weight of the polymer]

[0377] The weight-average molecular weight (Mw) of the polymer of the present invention is generally 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, further preferably 200,000 or less, and particularly preferably 100,000 or less. Additionally, it is generally 10,000 or more, preferably 15,000 or more, and more preferably 20,000 or more.

[0378] By setting the weight-average molecular weight of the polymer below the aforementioned upper limit, excellent film-forming properties are obtained, resulting in good solubility in solvents. Furthermore, by setting the weight-average molecular weight of the polymer above the aforementioned lower limit, the decrease in the polymer's glass transition temperature, melting point, and vaporization temperature is suppressed, sometimes improving heat resistance. In addition, the coating film after the crosslinking reaction sometimes exhibits sufficient insolubility in organic solvents.

[0379] Furthermore, the number average molecular weight (Mn) of the polymer of the present invention is generally 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, and particularly preferably 100,000 or less. Additionally, it is generally 2,000 or more, preferably 4,000 or more, more preferably 8,000 or more, and even more preferably 20,000 or more.

[0380] Furthermore, the dispersity (Mw / Mn) in the polymer of the present invention is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. It should be noted that since a smaller dispersity value is better, the lower limit is ideally 1. When the dispersity of the polymer of the present invention is below the above-mentioned upper limit, it is easy to purify, and also exhibits good solubility in solvents and charge transport capability.

[0381] Typically, the weight-average molecular weight and number-average molecular weight of polymers are determined by size exclusion chromatography (SEC). In SEC determination, the higher the molecular weight component, the shorter the elution time, and the lower the molecular weight component, the longer the elution time. Using a standard curve calculated from the elution time of polystyrene (a standard sample) with a known molecular weight, the dissolution time of the sample is converted into molecular weight, and the weight-average molecular weight and number-average molecular weight are calculated from this.

[0382] [Other repeating units]

[0383] In terms of charge transport and durability, the polymer of the present invention may further comprise repeating units represented by formula (5) or formula (6). Although the repeating unit represented by formula (5) below also comprises a structure consistent with a portion of the repeating units represented by formula (1), formula (2)-1, formula (2)-2, formula (3)-1 or formula (3)-2 above, it is a structure of other repeating units that are different from them.

[0384]

[0385] -Ar 12 - (6)

[0386] In equation (5), Ar 10 This indicates an aromatic hydrocarbon group that may have substituents or an aromatic heterocyclic group that may have substituents.

[0387] Ar 11 It refers to a divalent aromatic hydrocarbon group that may have substituents, a divalent aromatic heterocyclic group that may have substituents, or a divalent group formed by directly or indirectly connecting multiple groups selected from the aromatic hydrocarbon group that may have substituents and the aromatic heterocyclic group that may have substituents in the main chain direction.

[0388] In equation (6), Ar 12 It refers to a divalent aromatic hydrocarbon group that may have substituents, a divalent aromatic heterocyclic group that may have substituents, or a divalent group formed by directly or indirectly connecting multiple groups selected from the aromatic hydrocarbon group that may have substituents and the aromatic heterocyclic group that may have substituents in the main chain direction.

[0389] (Ar 10 Ar 11 and Ar 12 )

[0390] As Ar 10 Ar 11 and Ar 12 The aromatic hydrocarbon groups and aromatic heterocyclic groups in Ar 10 Ar represents the expression in equation (1) 1 The same group, Ar11 and Ar 12 Ar represents the expression (A1) 6 The same group. Ar 10 Ar 11 and Ar 12 The substituents that may be present are preferably the same as those in the substituent group Z or the crosslinking group described above.

[0391] Ar in the polymer of the present invention 10 When multiple Ar exist, multiple Ar 10 They can be the same or different.

[0392] [Preferred Polymers]

[0393] The polymer of the present invention preferably comprises repeating units represented by any of the following chemical formulas (7).

[0394]

[0395] In each polymer of chemical formula group (7), Ar 13 The above Ar 1 Ar 4 Multiple Ar in each polymer 13 The Ar content in each polymer can be the same or different. 13 At least one of them is the aforementioned Ar 1 X, R 1 R 2 R 20 R 21 R 22 R 23 Similar to equations (2)-1 and (2)-2 above. 1 m 1 This indicates the molar ratio of repeating units in a polymer.

[0396] [Specific example]

[0397] Specific examples of the polymers of the present invention are shown below, but are not limited thereto. It should be noted that the numbers in the chemical formulas indicate the molar ratio of repeating units.

[0398] These polymers can be any of random copolymers, alternating copolymers, block copolymers, or graft copolymers, and the order of the monomers is not limited.

[0399]

[0400]

[0401]

[0402]

[0403]

[0404]

[0405]

[0406]

[0407]

[0408]

[0409]

[0410]

[0411]

[0412]

[0413] [Polymer Manufacturing Methods]

[0414] There are no particular limitations on the method for manufacturing the polymer of the present invention. The polymer of the present invention can be manufactured, for example, by polymerization methods based on the Suzuki reaction, polymerization methods based on the Grignard reaction, polymerization methods based on the Yamamoto reaction, polymerization methods based on the Ullmann reaction, polymerization methods based on the Buchwald-Hartwig reaction, and so on.

[0415] When using polymerization methods based on the Ullmann reaction and polymerization methods based on the Buchwald-Hartwig reaction, for example, the polymer of the present invention is synthesized by reacting a dihalogenated aryl group (Y represents a halogen atom such as I, Br, Cl, F, etc.) represented by formula (1a) with a primary amino aryl group represented by formula (1b), and further reacting a compound represented by formula (2a).

[0416]

[0417] In the above formula, Ar 1 R 1 ~R 2 X, g, and i have the same meaning as in equations (2)-1 to (2)-2 above. 1 m 1 The numbers in a chemical formula represent the molar ratio of repeating units.

[0418] It should be noted that in the above polymerization methods, the reaction that forms N-aryl bonds is usually carried out in the presence of bases such as potassium carbonate, sodium tert-butoxide, and triethylamine.

[0419] Alternatively, it can be carried out in the presence of transition metal catalysts such as copper or palladium complexes.

[0420] <Organic Electroluminescent Element Materials>

[0421] The polymers of the present invention are particularly suitable for use as organic electroluminescent element materials. In other words, the polymers of the present invention are preferably organic electroluminescent element materials.

[0422] The polymer of the present invention is preferably used as a hole transport material because it is a polymer with excellent hole transport properties.

[0423] The polymers of the present invention are typically contained between the anode and the light-emitting layer in an organic electroluminescent element. That is, they are preferably used as materials for forming at least one of the hole injection layer and the hole transport layer, i.e., charge transport materials.

[0424] Furthermore, the polymer of the present invention can be included in the light-emitting layer of an organic electroluminescent element. That is, it can be used as a charge transport material included in the light-emitting layer.

[0425] When used as a charge transport material, it may contain one polymer of the present invention, or two or more polymers in any combination and in any ratio.

[0426] When at least one of the hole injection layer and hole transport layer of an organic electroluminescent element is formed using the polymer of the present invention, the content of the polymer of the present invention in the hole injection layer or hole transport layer is typically 1 to 100% by mass, preferably 5 to 100% by mass, and more preferably 10 to 100% by mass. Within the above range, the charge transport properties of the hole injection layer or hole transport layer are improved, the driving voltage is reduced, and the driving stability is improved, which is therefore preferred.

[0427] When the content of the polymer of the present invention is not 100% by mass in the hole injection layer or hole transport layer, hole transport compounds, etc., can be cited as components constituting the hole injection layer or hole transport layer.

[0428] Furthermore, since organic electroluminescent elements can be easily manufactured, the polymers of the present invention are preferably used in organic layers formed by wet film deposition.

[0429] <Compositions for Organic Electroluminescent Devices>

[0430] The organic electroluminescent device composition of the present invention contains the polymer of the present invention. It should be noted that the organic electroluminescent device composition of the present invention may contain one polymer of the present invention, or may contain two or more polymers in any combination and in any ratio.

[0431] [Polymer content]

[0432] The content of the polymer in the composition for organic electroluminescent elements of the present invention is generally 0.01 to 70% by mass, preferably 0.1 to 60% by mass, and more preferably 0.5 to 50% by mass.

[0433] Within the above range, the formed organic layer is less prone to defects and uneven film thickness, and is therefore preferred.

[0434] It should be noted that the composition for organic electroluminescent elements of the present invention may contain solvents or the like in addition to the polymers described above.

[0435] [solvent]

[0436] The organic electroluminescent device composition of the present invention typically contains a solvent. This solvent preferably dissolves the aforementioned polymer. Specifically, a solvent that typically dissolves 0.05% by mass or more, preferably 0.5% by mass or more, and more preferably 1% by mass or more of the aforementioned polymer at room temperature is suitable.

[0437] Specific examples of solvents include aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene; halogen-containing solvents such as 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, and 2... Ether solvents such as aromatic ethers like 3-dimethylanisole and 2,4-dimethylanisole; aliphatic ester solvents such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; ester solvents such as aromatic esters like phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, isopropyl benzoate, propyl benzoate, and n-butyl benzoate; and organic solvents used in the hole injection layer formation composition and hole transport layer formation composition described later.

[0438] It should be noted that one solvent may be used, or two or more solvents may be used in any combination and in any ratio.

[0439] The solvent contained in the composition for the organic electroluminescent element of the present invention is preferably a solvent with a surface tension of less than 40 dyn / cm at 20°C, more preferably less than 36 dyn / cm, and more preferably less than 33 dyn / cm.

[0440] When forming a coating using the organic electroluminescent element composition of the present invention via a wet film deposition method, and crosslinking the aforementioned polymer to form an organic layer, it is preferable that the solvent has a high affinity for the substrate. This is because the uniformity of the film significantly affects the uniformity and stability of the luminescence emitted by the organic electroluminescent element. Therefore, the organic electroluminescent element composition used in the wet film deposition method requires low surface tension to achieve higher leveling properties and form a uniform coating. Therefore, by using a solvent with the low surface tension described above, a uniform layer containing the aforementioned polymer can be formed, and consequently, a uniform crosslinked layer can be formed, which is preferable.

[0441] Specific examples of solvents with low surface tension include aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene; ester solvents such as ethyl benzoate; ether solvents such as anisole; trifluoromethoxyanisole; pentafluoromethoxybenzene; 3-(trifluoromethyl)anisole; and ethyl (pentafluorobenzoate).

[0442] On the other hand, the solvent contained in the organic electroluminescent element composition of the present invention is preferably a solvent with a vapor pressure of typically 10 mmHg or less at 25°C, more preferably 5 mmHg or less, and typically 0.1 mmHg or more. By using such a solvent, it is suitable for a process of manufacturing organic electroluminescent elements using a wet film deposition method, and it is possible to prepare an organic electroluminescent element composition suitable for the properties of the polymer of the present invention.

[0443] Specific examples of such solvents include aromatic solvents such as toluene, xylene, and mesitylene, as well as ether solvents and ester solvents.

[0444] However, moisture can degrade the performance of organic electroluminescent elements, particularly by promoting a decrease in brightness during continuous operation. Therefore, in order to minimize residual moisture in wet film formation, solvents with a water solubility of 1% by mass or less at 25°C are preferred, and solvents with a water solubility of 0.1% by mass or less at 25°C are more preferred.

[0445] The solvent content in the organic electroluminescent element composition of the present invention is typically 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 80% by mass or more. By having a solvent content of the above-mentioned lower limit or above, the flatness and uniformity of the formed layer can be improved.

[0446] [Electron-accepting compounds]

[0447] Regarding low resistance, the organic electroluminescent element composition of the present invention preferably further contains an electron-accepting compound. In particular, when the organic electroluminescent element composition of the present invention is used to form a hole injection layer, it is preferable to contain an electron-accepting compound.

[0448] As an electron-accepting compound, it is preferred to have oxidizing ability and the ability to accept an electron from the polymer. Specifically, compounds with an electron affinity of 4 eV or more are preferred, and compounds with an electron affinity of 5 eV or more are even more preferred.

[0449] Examples of such electron-accepting compounds include, for example, one or more compounds selected from triarylboron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids.

[0450] Specifically, examples include onium salts with substituted organic groups, such as 4-isopropyl-4'-methyldiphenyliodonium tetra(pentafluorophenyl)borate and triphenylsulfonium tetrafluoroborate (International Publication No. 2005 / 089024, International Publication No. 2017 / 164268); inorganic compounds with high atomic valences, such as ferric chloride (III) (Japanese Patent Application Publication No. 11-251067) and ammonium peroxydisulfate; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tri(pentafluorophenyl)borane (Japanese Patent Application Publication No. 2003-31365); fullerene derivatives and iodine, etc.

[0451] The composition for organic electroluminescent elements of the present invention may contain only one electron-accepting compound as described above, or may contain two or more compounds in any combination and ratio.

[0452] When the composition for organic electroluminescent elements of the present invention contains an electron-accepting compound, the content of the electron-accepting compound is generally 0.0005% by mass or more, preferably 0.001% by mass or more, generally 20% by mass or less, and preferably 10% by mass or less. Furthermore, the content of the electron-accepting compound in the composition for organic electroluminescent elements relative to the above-mentioned polymer is generally 0.5% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, generally 80% by mass or less, preferably 60% by mass or less, and even more preferably 40% by mass or less.

[0453] When the content of the electron-accepting compound in the composition for organic electroluminescent elements is at or above the lower limit mentioned above, the organic layer formed has low resistance because the electron acceptor accepts electrons from the polymer. Therefore, it is preferable. When the content is below the upper limit mentioned above, the organic layer formed is less prone to defects and less prone to uneven film thickness. Therefore, it is preferable.

[0454] [Cat radical compounds]

[0455] The composition for organic electroluminescent elements of the present invention may further contain cationic free radical compounds.

[0456] As a cationic radical compound, it is preferable to be an ionic compound consisting of a cationic radical, which is a chemical substance obtained by removing an electron from a hole-transporting compound, and a counter anion. Wherein, when the cationic radical originates from a hole-transporting polymer, the cationic radical becomes a structure obtained by removing an electron from a repeating unit of the polymer.

[0457] Furthermore, the preferred cation radical is a chemical substance obtained by removing one electron from a hole-transporting compound described later. Considering factors such as amorphousness, visible light transmittance, heat resistance, and solubility, the preferred cation radical is a chemical substance obtained by removing one electron from a compound preferred as a hole-transporting compound.

[0458] Here, the cationic radical compound can be generated by mixing the hole-transporting compound (described later) with the electron-accepting compound (described earlier). That is, by mixing the hole-transporting compound with the electron-accepting compound, an electron transfer occurs from the hole-transporting compound to the electron-accepting compound, generating a cationic compound composed of the cationic radical of the hole-transporting compound and a counter anion.

[0459] When the organic electroluminescent element composition of the present invention contains a cationic radical compound, the content of the cationic radical compound in the organic electroluminescent element composition is generally 0.0005% by mass or more, preferably 0.001% by mass or more, generally 40% by mass or less, and preferably 20% by mass or less. When the content of the cationic radical compound is at or above the lower limit, the formed organic layer has low resistance, which is therefore preferred. When the content is at or below the upper limit, the formed organic layer is less prone to defects and less prone to uneven film thickness, which is also preferred.

[0460] It should be noted that, in addition to the components described above, the organic electroluminescent element composition of the present invention may also contain, in the amounts described below, the components included in the hole injection layer formation composition and the hole transport layer formation composition.

[0461] <Light-emitting layer materials>

[0462] In an organic electroluminescent element in which the polymer of the present invention is used as a charge-transmitting material for forming at least one of a hole injection layer and a hole transport layer, the light-emitting layer comprises a light-emitting material and a host material.

[0463] The luminescent material can be either a phosphorescent material or a fluorescent material.

[0464] In organic electroluminescent devices in which the polymer of the present invention is used as a charge-transmitting material for forming at least one of a hole injection layer and a hole transport layer, when the light-emitting layer is a phosphorescent layer, the following materials are preferred as phosphorescent materials.

[0465] [Phosphorescent materials]

[0466] Phosphorescent materials are materials that exhibit luminescence from an excited triplet state. For example, metal complexes containing Ir, Pt, Eu, etc., are representative examples, and the structure of such materials preferably includes metal complexes.

[0467] Among metal complexes, phosphorescent organometallic complexes that emit light via a triplet state are examples of Werner-type complexes or organometallic complexes containing a metal selected from Groups 7 to 11 of the long-period periodic table (hereinafter, unless otherwise specified, "periodic table" refers to the long-period periodic table) as the central metal. As such phosphorescent materials, compounds represented by formula (201) or formula (202) are preferred, and compounds represented by formula (201) are more preferred.

[0468]

[0469] In equation (201), M is a metal selected from groups 7 to 11 of the periodic table, such as ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, and europium.

[0470] Ring A1 represents an aromatic hydrocarbon ring structure that may have substituents or an aromatic heterocyclic structure that may have substituents.

[0471] Ring A2 represents an aromatic heterocyclic structure that can have substituents.

[0472] R 201 R 202 Each is an independent structure represented by the above formula (202), where "*" indicates bonding with ring A1 and / or ring A2. R 201 R 202 They can be the same or different, R 201 R 202 When multiple instances exist, they can be the same or different.

[0473] Ar 201 Ar 203 Each can independently represent an aromatic hydrocarbon ring structure that may have substituents or an aromatic heterocyclic structure that may have substituents.

[0474] Ar 202This indicates an aromatic hydrocarbon ring structure that can have substituents, an aromatic heterocyclic structure that can have substituents, or an aliphatic hydrocarbon structure that can have substituents.

[0475] Substituents bonded to ring A1, substituents bonded to ring A2, or substituents bonded to ring A1 and substituents bonded to ring A2 can bond to each other to form a ring.

[0476] B 201 -L 200 -B 202 B represents anionic bidentate ligands. 201 and B 202 Each atom can be independently represented by a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms can be the atoms that make up the ring. L 200 Indicates a single bond or a bond with B. 201 and B 202 Together, they form a group of atoms that constitute a bidentate ligand. B 201 -L 200 -B 202 When multiple instances exist, they may be the same or different.

[0477] i1 and i2 each independently represent integers from 0 to 12.

[0478] i3 is a potential replacement for Ar 202 The number of elements is an integer greater than or equal to 0, which is the upper limit.

[0479] j1 is a replacement for Ar 201 The number of elements is an integer greater than or equal to 0, which is the upper limit.

[0480] k1 and k2 are each independent integers greater than 0 with the number of substitutable rings A1 and A2 as the upper limit.

[0481] m1 is an integer from 1 to 3.

[0482] <Substituted base set Z'>

[0483] • Alkyl group, preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, even more preferably an alkyl group having 1 to 8 carbon atoms, and particularly preferably an alkyl group having 1 to 6 carbon atoms.

[0484] • Alkoxy group, preferably an alkoxy group with 1 to 20 carbon atoms, more preferably an alkoxy group with 1 to 12 carbon atoms, and even more preferably an alkoxy group with 1 to 6 carbon atoms.

[0485] • Aryloxy group, preferably an aryloxy group with 6 to 20 carbon atoms, more preferably an aryloxy group with 6 to 14 carbon atoms, even more preferably an aryloxy group with 6 to 12 carbon atoms, and particularly preferably an aryloxy group with 6 carbon atoms.

[0486] • Heteroaryloxy group, preferably a heteroaryloxy group with 3 to 20 carbon atoms, more preferably a heteroaryloxy group with 3 to 12 carbon atoms.

[0487] • Alkylamino, preferably alkylamino with 1 to 20 carbon atoms, more preferably alkylamino with 1 to 12 carbon atoms.

[0488] • Arylamino, preferably arylamino with 6 to 36 carbon atoms, more preferably arylamino with 6 to 24 carbon atoms.

[0489] • Aryl group, preferably an aryl group with 7 to 40 carbon atoms, more preferably an aryl group with 7 to 18 carbon atoms, and even more preferably an aryl group with 7 to 12 carbon atoms.

[0490] • Heteroaryl groups, preferably heteroaryl groups with 7 to 40 carbon atoms, more preferably heteroaryl groups with 7 to 18 carbon atoms.

[0491] • Alkenyl, preferably an alkenyl with 2 to 20 carbon atoms, more preferably an alkenyl with 2 to 12 carbon atoms, even more preferably an alkenyl with 2 to 8 carbon atoms, and particularly preferably an alkenyl with 2 to 6 carbon atoms.

[0492] • Alkyne group, preferably an alkyne group with 2 to 20 carbon atoms, more preferably an alkyne group with 2 to 12 carbon atoms.

[0493] • Aryl, preferably aryl with 6 to 30 carbon atoms, more preferably aryl with 6 to 24 carbon atoms, even more preferably aryl with 6 to 18 carbon atoms, and particularly preferably aryl with 6 to 14 carbon atoms.

[0494] • Heteroaryl, preferably a heteroaryl having 3 to 30 carbon atoms, more preferably a heteroaryl having 3 to 24 carbon atoms, even more preferably a heteroaryl having 3 to 18 carbon atoms, and particularly preferably a heteroaryl having 3 to 14 carbon atoms.

[0495] • Alkyl silyl group, preferably an alkyl silyl group having 1 to 20 carbon atoms, more preferably an alkyl silyl group having 1 to 12 carbon atoms.

[0496] • Arylsilyl group, preferably arylsilyl group with 6 to 20 carbon atoms of aryl group, more preferably arylsilyl group with 6 to 14 carbon atoms of aryl group.

[0497] • Alkyl carbonyl, preferably an alkyl carbonyl group with 2 to 20 carbon atoms.

[0498] • Aryl carbonyl, preferably aryl carbonyl with 7 to 20 carbon atoms.

[0499] • Hydrogen atom, deuterium atom, fluorine atom, cyano group or -SF5.

[0500] One or more hydrogen atoms in the above groups can be replaced by fluorine atoms, or one or more hydrogen atoms can be replaced by deuterium atoms.

[0501] (Preferred substituent groups in substituent group Z')

[0502] In these substituent base sets Z'

[0503] Preferably, the groups are alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, alkylsilyl, arylsilyl, and groups in which one or more hydrogen atoms of these groups are replaced by fluorine atoms, fluorine atoms, cyano, or -SF5.

[0504] More preferably, it is an alkyl, arylamino, aralkyl, alkenyl, aryl, heteroaryl, and groups in which one or more hydrogen atoms of these groups are replaced by fluorine atoms, fluorine atoms, cyano, or -SF5.

[0505] Further preferred are alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, alkylsilyl, and arylsilyl.

[0506] Particularly preferred are alkyl, arylamino, aralkyl, alkenyl, aryl, and heteroaryl groups.

[0507] The most preferred compounds are alkyl, arylamino, aralkyl, aryl, and heteroaryl.

[0508] (Substituents replacing Z')

[0509] These substituent groups Z' may further have substituents selected from substituent group Z' as substituents. The preferred groups, more preferred groups, further preferred groups, particularly preferred groups, and most preferred groups of the substituents that may be present are the same as the preferred groups in substituent group Z'.

[0510] (Ring A1)

[0511] Ring A1 represents an aromatic hydrocarbon ring structure that may have substituents or an aromatic heterocyclic structure that may have substituents.

[0512] The aromatic hydrocarbon ring of ring A1 is preferably an aromatic hydrocarbon ring with 6 to 30 carbon atoms. Specifically, benzene ring, naphthalene ring, anthracene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, and fluorene ring are preferred.

[0513] As an aromatic heterocycle of ring A1, it is preferably an aromatic heterocycle with 3 to 30 carbon atoms containing any one of nitrogen, oxygen or sulfur atoms as heteroatoms, and more preferably a furan ring, benzofuran ring, thiophene ring or benzothiophene ring.

[0514] The 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.

[0515] (Ring A2)

[0516] Ring A2 represents an aromatic heterocyclic structure that can have substituents.

[0517] The aromatic heterocycle of ring A2 is preferably an aromatic heterocycle with 3 to 30 carbon atoms containing nitrogen, oxygen, or sulfur atoms as heteroatoms. Specifically, examples include pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, and imidazole rings. azole ring, thiazole ring, benzothiazole ring, benzo[] The rings are azole rings, benzimidazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, naphthidine rings, phenanthridine rings, and more preferably pyridine rings, pyrazine rings, pyrimidine rings, imidazole rings, benzothiazole rings, and benzo[] ... The ring may be an azole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, or a quinazoline ring, more preferably a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, or a quinazoline ring, and most preferably a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, a quinoxaline ring, or a quinazoline ring.

[0518] As a preferred combination of ring A1 and ring A2, when represented as (ring A1 - ring A2), it is (benzene ring - pyridine ring), (benzene ring - quinoline ring), (benzene ring - quinoxaline ring), (benzene ring - quinazoline ring), (benzene ring - imidazole ring), (benzene ring - benzothiazole ring).

[0519] (Substituents in ring A1 and ring A2)

[0520] The substituents that ring A1 and ring A2 may have can be arbitrarily selected, but are preferably one or more substituents selected from the above substituent group Z'.

[0521] (Ar 201 Ar 202 Ar 203 )

[0522] Ar 201 Ar 203 Each can independently represent an aromatic hydrocarbon ring structure that may have substituents or an aromatic heterocyclic structure that may have substituents.

[0523] Ar 202 This indicates an aromatic hydrocarbon ring structure that can have substituents, an aromatic heterocyclic structure that can have substituents, or an aliphatic hydrocarbon structure that can have substituents.

[0524] (Ar 201 Ar 202 Ar 203(aromatic hydrocarbon ring)

[0525] Ar 201 Ar 202 Ar 203 When any of the components is an aromatic hydrocarbon ring structure that can have substituents, the aromatic hydrocarbon ring structure is preferably an aromatic hydrocarbon ring with 6 to 30 carbon atoms. Specifically, benzene ring, naphthalene ring, anthracene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, and fluorene ring are preferred, benzene ring, naphthalene ring, and fluorene ring are more preferred, and benzene ring is most preferred.

[0526] (9,9' of the eu)

[0527] Ar 201 Ar 202 Ar 203 When either of the fluorene rings is a substituent, the 9th and 9' positions of the fluorene ring preferably have substituents or are bonded to adjacent structures.

[0528] (ortho- and meta-phenylene)

[0529] Ar 201 Ar 202 When any of the components is a benzene ring that may have substituents, it is preferable that at least one benzene ring is bonded to an adjacent structure at the ortho or meta position, and more preferably at least one benzene ring is bonded to an adjacent structure at the meta position.

[0530] (Ar 201 Ar 202 Ar 203 (aromatic heterocycles)

[0531] Ar 201 Ar 202 Ar 203 When any of the components is an aromatic heterocyclic structure that can have substituents, the preferred aromatic heterocyclic structure is an aromatic heterocycle with 3 to 30 carbon atoms containing nitrogen, oxygen, or sulfur atoms as heteroatoms. Specifically, examples include pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, and imidazole rings. azole ring, thiazole ring, benzothiazole ring, benzo[] The rings are azole rings, benzimidazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, naphthidine rings, phenanthridine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings, and are more preferably pyridine rings, pyrimidine rings, triazine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings.

[0532] (N position of carbazole)

[0533] Ar 201 Ar 202 Ar 203When either of the carbazole rings can have substituents, the N-position of the carbazole ring preferably has a substituent or is bonded to an adjacent structure.

[0534] (Ar 202 (aliphatic hydrocarbons)

[0535] Ar 202 When the structure is an aliphatic hydrocarbon that can have substituents, it is an aliphatic hydrocarbon structure having a straight chain, a branched chain, or a cyclic structure, preferably having 1 to 24 carbon atoms, more preferably having 1 to 12 carbon atoms, and even more preferably having 1 to 8 carbon atoms.

[0536] (Preferred range of i1 and i2)

[0537] i1 and i2 represent integers from 0 to 12, preferably from 1 to 12, more preferably from 1 to 8, and even more preferably from 1 to 6. Within this range, improved solubility and improved charge transport can be expected.

[0538] (Preferred range of i3)

[0539] i3 preferably represents an integer from 0 to 5, more preferably from 0 to 2, and even more preferably 0 or 1.

[0540] (Preferred range of j1)

[0541] j1 preferably represents an integer from 0 to 2, and more preferably 0 or 1.

[0542] (Preferred range of k1 and k2)

[0543] k1 and k2 preferably represent integers from 0 to 3, more preferably from 1 to 3, even more preferably 1 or 2, and especially preferably 1.

[0544] (Ar 201 Ar 202 Ar 203 (Preferred substituents)

[0545] Ar 201 Ar 202 Ar 203 The substituents that can be present can be arbitrarily selected, preferably one or more substituents selected from the substituent group Z' above. The preferred groups are also as described in the substituent group Z' above, more preferably hydrogen atoms, alkyl groups, aryl groups, particularly preferably hydrogen atoms, alkyl groups, and most preferably unsubstituted (hydrogen atoms).

[0546] (Preferred structure of equation (201))

[0547] Of the structures described in formula (201) above, the following structure is preferred.

[0548] (Phenylidene-linked)

[0549] It has a structure with groups linked together by benzene rings. That is, Ar 201 The structure is a benzene ring, i1 is 1 to 6, and at least one of the aforementioned benzene rings is bonded to an adjacent structure at the ortho or meta position. With this structure, improved solubility and charge transport can be expected.

[0550] ((phenylene)-(aralkyl)-(alkyl))

[0551] A structure having an aromatic hydrocarbon cyclogroup or aromatic heterocyclic group bonded to ring A1 or ring A2. That is, Ar 201 It has an aromatic hydrocarbon ring structure or an aromatic heterocyclic structure, i1 is 1 to 6, Ar 202 It has an aliphatic hydrocarbon structure, i2 is 1 to 12, preferably 3 to 8, and Ar 203 It has a benzene ring structure, and i3 is 0 or 1. Ar is preferred. 201 The aforementioned aromatic hydrocarbon ring structure is more preferably a structure consisting of 1 to 5 benzene rings, and more preferably a single benzene ring. This structure can be expected to improve solubility and charge transport properties.

[0552] (Dendromorphic molecules)

[0553] A structure in which dendritic molecules are bonded to ring A1 or ring A2. For example, Ar 201 Ar 202 It has a benzene ring structure, Ar 203 The structure is biphenyl or terphenyl, i1 and i2 are 1 to 6, i3 is 2, and j is 2. With this structure, improved solubility and charge transport can be expected.

[0554] (B 201 -L 200 -B 202 )

[0555] B 201 -L 200 -B 202 B represents anionic bidentate ligands. 201 and B 202 Each atom can be independently represented as a carbon atom, oxygen atom, or nitrogen atom; these atoms can also be the atoms that make up a ring. L 200 Indicates a single bond or a bond with B. 201 and B 202 Together, they form a group of atoms that constitute a bidentate ligand. B 201 -L 200 -B 202 When multiple instances exist, they may be the same or different.

[0556] B 201 -L200 -B 202 The structure represented is preferably the structure represented by the following formula (203) or (204).

[0557]

[0558] In equation (203), R 211 R 212 R 213 Indicates a substituent.

[0559] The substituents can be chosen arbitrarily, but are preferably one or more substituents selected from the substituent group Z' mentioned above.

[0560]

[0561] In formula (204), ring B3 represents an aromatic heterocyclic structure containing nitrogen atoms that may have substituents. Ring B3 is preferably a pyridine ring.

[0562] The substituents that ring B3 may have are not particularly limited, but are preferably one or more substituents selected from the substituent group Z' mentioned above.

[0563] (Preferred phosphorescent material represented by formula (201))

[0564] The phosphorescent material represented by formula (201) is not particularly limited, but the following structures can be specifically cited.

[0565]

[0566]

[0567]

[0568]

[0569] (The compound represented by formula (205))

[0570] In addition, as a phosphorescent material, the compound represented by the following formula (205) is preferred.

[0571]

[0572] In equation (205), M 2 T represents a metal, and T represents a carbon or nitrogen atom. R 92 ~R 95 Each substituent can be represented independently. When T is a nitrogen atom, there is no R. 94 and R 95 .

[0573] In equation (205), M2 The metal is indicated. Specific examples include the aforementioned metals selected from groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold are preferred, and divalent metals such as platinum and palladium are particularly preferred.

[0574] In addition, in equation (205), R 92 and R 93 Each can independently represent a hydrogen atom, halogen atom, alkyl, aralkyl, alkenyl, cyano, amino, acyl, alkoxycarbonyl, carboxyl, alkoxy, alkylamino, aralkylamino, haloalkyl, hydroxyl, aryloxy, aromatic hydrocarbon, or aromatic heterocyclic group.

[0575] Furthermore, when T is a carbon atom, R 94 and R 95 Each is independently represented by R 92 and R 93 The same examples represent substituents. Additionally, when T is a nitrogen atom, there is no R directly bonded to that T. 94 or R 95 .

[0576] Additionally, R 92 ~R 95 It can further have substituents. These substituents can be the ones described above. Furthermore, R 92 ~R 95 Any two or more groups in it can connect with each other to form a ring.

[0577] (Molecular weight of phosphorescent materials)

[0578] 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 typically 800 or more, preferably 1000 or more, and more preferably 1200 or more. It is believed that within this molecular weight range, the phosphorescent material can be uniformly mixed with the charge transport material without agglomerating, resulting in a light-emitting layer with high luminous efficiency.

[0579] From the perspectives of high Tg, melting point, decomposition temperature, excellent heat resistance of the phosphorescent material and the formed luminescent layer, and less likelihood of film quality degradation due to gas generation, recrystallization, and molecular migration, as well as the reduction in impurity concentration accompanying thermal decomposition of the material, a larger molecular weight of the phosphorescent material is preferred. On the other hand, for the sake of easy purification of organic compounds, a smaller molecular weight of the phosphorescent material is better.

[0580] [Main Material]

[0581] In an organic electroluminescent element in which a polymer, as an embodiment of the present invention, is used as a charge-transmitting material for forming at least one of a hole injection layer and a hole transport layer, and the light-emitting layer is a phosphorescent material, the following materials are preferred as the main material.

[0582] <Main Material>

[0583] The main material of the light-emitting layer is a framework material with excellent charge transport properties, preferably selected from electron transport materials, hole transport materials, and bipolar materials that can transport both electrons and holes.

[0584] (A framework with excellent charge transport properties)

[0585] As a framework with excellent charge transport properties, examples 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, o-phenanthroline structures, quinoline structures, pyridine structures, pyrimidine structures, and triazine structures. Diazole or imidazole structures, etc.

[0586] (Electron transport materials)

[0587] From the viewpoint that a structure with excellent electron transport properties is a relatively stable material, compounds having pyridine, pyrimidine, or triazine structures are preferred as electron transport materials, and compounds having pyrimidine or triazine structures are even more preferred.

[0588] (Hole-transporting materials)

[0589] Hole transport material is a compound with a structure that has excellent hole transport properties. In the above-mentioned central framework with excellent charge transport properties, the structure with excellent hole transport properties is preferably a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure or a pyrene structure. The structure with excellent hole transport properties is even more preferably a carbazole structure, a dibenzofuran structure or a triarylamine structure.

[0590] Alternatively, the polymer of the present invention can also be used as a hole transport material contained in the light-emitting layer.

[0591] (Fused ring structure with three or more rings)

[0592] The host material of the light-emitting layer is preferably a compound having a fused ring structure of three or more rings, 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 molecules is increased, making it easier to suppress the degree of molecular motion in thermal response. Furthermore, in terms of charge transport and material durability, it is preferable that the fused rings of three or more rings and the fused rings of five or more rings have aromatic hydrocarbon rings or aromatic heterocycles.

[0593] As fused ring structures with three or more rings, examples include anthracene, phenanthrene, and pyrene structures. Structures include tetraphenyl, triphenylene, fluorene, benzo[a]fluorene, indo[a]fluorene, indole[a]fluorene, carbazole, indo[a]carbazole, indole[a]carbazole, dibenzofuran, and dibenzothiophene.

[0594] From the viewpoint of charge transport and solubility, it is preferably selected from at least one of the following structures: phenanthrene, fluorene, indo[f]fluorene, carbazole, indo[f]carbazole, indole[f]carbazole, dibenzofuran, and dibenzothiophene. From the viewpoint of charge durability, carbazole or indole[f]carbazole is further preferred.

[0595] From the viewpoint of the durability of organic electroluminescent elements to charge, in this invention, at least one of the main materials of the light-emitting layer is preferably a material having a pyrimidine framework or a triazine framework.

[0596] (Molecular weight range)

[0597] From the viewpoint of excellent flexibility, the main material of the light-emitting layer is preferably a polymer material. The light-emitting layer formed using a highly flexible material is preferably the light-emitting layer of an organic electroluminescent element formed on a flexible substrate. When the main 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.

[0598] Furthermore, from the viewpoints of ease of synthesis and purification, ease of designing electron transport and hole transport properties, and ease of viscosity adjustment when dissolved in a solvent, the host material of the light-emitting layer is preferably a low molecular weight material. When the host material contained in the light-emitting layer is a low molecular weight material, the molecular weight is preferably 5000 or less, more preferably 4000 or less, particularly preferably 3000 or less, most preferably 2000 or less, typically 300 or more, preferably 350 or more, and more preferably 400 or more.

[0599] [Fluorescent Emitting Layer Material]

[0600] In organic electroluminescent elements in which the polymer of the present invention is used as a charge-transmitting material for forming at least one of a hole injection layer and a hole transport layer, when the light-emitting layer is a fluorescent light-emitting layer material, the following blue fluorescent light-emitting layer material is preferred.

[0601] (Blue fluorescent emissive layer material)

[0602] There are no particular limitations on the blue fluorescent emitting layer material, but the compound represented by the following formula (211) is preferred.

[0603]

[0604] In the above equation (211), Ar 241 Ar represents an aromatic hydrocarbon fused ring structure that can have substituents. 242 Ar 243 Each can independently represent an alkyl group that may have substituents, an aromatic hydrocarbon group that may have substituents, or a group formed by their bonding or condensation. n41 is an integer from 1 to 4.

[0605] Ar 241 Preferably, the structure represents a fused ring structure of an aromatic hydrocarbon with 10 to 30 carbon atoms. Specific examples of such structures include naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, and tetraphenylene. Perylene, etc. More preferably, it is an aromatic hydrocarbon fused ring structure with 12 to 20 carbon atoms; specific structures include acenaphthene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, and tetraphenylene. Perylene. More preferably, it has an aromatic hydrocarbon fused ring structure with 16-18 carbon atoms. Examples of specific structures include fluoranthene, pyrene, etc.

[0606] Ar 242 Ar 243 The alkyl group is preferably a straight-chain, branched, or cyclic alkyl group that may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but to maintain the solubility of the blue fluorescent emitting layer material, the number of carbon atoms is preferably 1 to 6, more preferably 3 or less. The alkyl group is further preferably methyl, ethyl, or tert-butyl.

[0607] Ar 242 Ar 243 They can be the same or different. Ar 242 Ar 243Preferably, the aromatic hydrocarbon ring structure having 6 to 18 carbon atoms or a group formed by their bonding or condensation is used. Specific structures include benzene rings, biphenyl rings, terphenyl rings, naphthyl rings, fluorene rings, dibenzothiophene rings, dibenzofuran rings, carbazole rings, triphenylene rings, and perylene rings. More preferably, the aromatic hydrocarbon ring structure having 6 to 12 carbon atoms or a group formed by their bonding or condensation is used. Specific structures include benzene rings, biphenyl rings, terphenyl rings, naphthyl rings, fluorene rings, dibenzothiophene rings, dibenzofuran rings, and carbazole rings. Even more preferably, the aromatic hydrocarbon ring structure having 12 carbon atoms or a group formed by their condensation is used. Specific structures include fluorene rings, dibenzothiophene rings, dibenzofuran rings, and carbazole rings.

[0608] n41 is an integer from 1 to 4, preferably from 1 to 3, further preferably from 1 to 2, and most preferably from 2.

[0609] (Ar 241 Ar 242 Ar 243 (substituents)

[0610] Ar 241 Ar 242 Ar 243 The substituents that may be present are preferably selected from groups in the substituent group Z', more preferably hydrocarbon groups contained in the substituent group Z', and even more preferably hydrocarbon groups among the groups preferred in the substituent group Z'.

[0611] (Main material for the blue fluorescent emitting layer)

[0612] In organic electroluminescent elements in which the polymer of the present invention is used as a charge-transmitting material for forming at least one of a hole injection layer and a hole transport layer, when the light-emitting layer is a fluorescent light-emitting material, the following materials are preferred as the main material.

[0613] There are no particular limitations on the main material used for the blue fluorescent emitting layer, but the compound represented by the following formula (212) is preferred.

[0614]

[0615] In the above equation (212), R 241 R 242 Each of the structures represented independently by the following equation (213), R 243 R represents a substituent. 243 When multiple instances exist, they can be the same or different, and n43 is an integer from 0 to 8.

[0616]

[0617] Ar 244 Ar 245Each can independently represent an aromatic hydrocarbon ring structure that may have substituents, or a heteroaromatic ring structure that may have substituents. Ar 244 Ar 245 When multiple n44 and n45 exist, they can be the same or different. n44 is an integer from 1 to 5, and n45 is an integer from 0 to 5.

[0618] Ar 244 Preferably, it is an aromatic hydrocarbon ring structure having a single ring or fused ring with 6 to 30 carbon atoms that may have substituents, and more preferably, it is an aromatic hydrocarbon ring structure having a single ring or fused ring with 6 to 12 carbon atoms that may have substituents.

[0619] Ar 245 Preferably, it is an aromatic hydrocarbon ring structure having substituents as a monocyclic or fused ring with 6 to 30 carbon atoms, or an aromatic heterocyclic structure having substituents as a fused ring with 6 to 30 carbon atoms. More preferably, it is an aromatic hydrocarbon ring structure having substituents as a monocyclic or fused ring with 6 to 12 carbon atoms, or an aromatic heterocyclic structure having substituents as a fused ring with 12 carbon atoms.

[0620] n44 is preferably 1 to 3, more preferably 1 or 2, and n45 is preferably 0 to 3, more preferably 0 to 2.

[0621] (R 243 Ar 244 Ar 245 (substituents)

[0622] R as a substituent 243 And Ar 244 and Ar 245 The substituents that may be present are preferably selected from groups in the substituent group Z', more preferably hydrocarbon groups contained in the substituent group Z', and even more preferably hydrocarbon groups among the groups preferred in the substituent group Z'.

[0623] (molecular weight)

[0624] The molecular weight of the luminescent material and the host material used in the blue fluorescent luminescent layer is preferably below 5000, more preferably below 4000, particularly preferably below 3000, most preferably below 2000, usually above 300, preferably above 350, and more preferably above 400.

[0625] Organic electroluminescent devices

[0626] The organic electroluminescent element of the present invention is characterized in that it has an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, the organic layer comprising a layer formed by using an organic electroluminescent element composition containing the above-mentioned polymer by a wet film deposition method.

[0627] In the organic electroluminescent element of the present invention, the layer formed by wet film deposition is preferably at least one of a hole injection layer and a hole transport layer. It is particularly preferred that the organic layer has a hole injection layer, a hole transport layer and a light-emitting layer, all of which are formed by wet film deposition.

[0628] In this invention, wet film formation refers to a method that uses wet film formation methods, such as spin coating, dip coating, mold coating, rod coating, doctor blade coating, roller coating, spray coating, capillary coating, inkjet coating, nozzle printing, screen printing, gravure printing, and flexographic printing, as the film formation method, and then dries the resulting coated film to form a film. Among these film formation methods, spin coating, spray coating, inkjet printing, and nozzle printing are preferred.

[0629] As an example of the structure of the organic electroluminescent element of the present invention, in Figure 1 A schematic diagram (cross-section) of a structural example of the organic electroluminescent element 10 is shown. Figure 1 In the diagram, 1 represents the substrate, 2 represents the anode, 3 represents the hole injection layer, 4 represents the hole transport layer, 5 represents the light-emitting layer, 6 represents the hole blocking layer, 7 represents the electron transport layer, 8 represents the electron injection layer, and 9 represents the cathode.

[0630] The following is for reference Figure 1 An example of an embodiment, including the layer structure of an organic electroluminescent element and its general formation method, will be described.

[0631] [Substrate]

[0632] The substrate 1 serves as the support for the organic electroluminescent element and is typically made of materials such as quartz, glass, metal, metal foil, plastic film, or sheet. Glass or transparent synthetic resin substrates such as polyester, polymethyl methacrylate, polycarbonate, or polysulfone are preferred. Since it is difficult for the organic electroluminescent element to deteriorate due to external air, the substrate is preferably made of a material with high gas barrier properties. Therefore, especially when using a material with low gas barrier properties, such as a substrate made of synthetic resin, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve gas barrier properties.

[0633] [anode]

[0634] Anode 2 functions to inject holes into the layer on the side of the light-emitting layer 5.

[0635] Anode 2 is typically 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.

[0636] The anode 2 is typically formed using dry methods such as sputtering or vacuum evaporation. Alternatively, when using metal particles such as silver, copper iodide, carbon black, conductive metal oxide particles, or conductive polymer powders to form the anode, it can be formed by dispersing them in a suitable binder resin solution and coating them onto a substrate. Furthermore, in the case of conductive polymers, a thin film can be formed directly on the substrate via electrolytic polymerization, or the anode can be formed by coating the conductive polymer onto the substrate (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0637] Anode 2 is typically a single-layer structure, but it can also be made into a multilayer structure. When anode 2 is a multilayer structure, different conductive materials can be stacked on top of the first anode layer.

[0638] The thickness of anode 2 can be determined based on the required transparency and material properties. In particular, when high transparency is required, a thickness with a visible light transmittance of 60% or more is preferred, and a thickness of 80% or more is even more preferred. The thickness of anode 2 is typically 5 nm or more, preferably 10 nm or more, and typically 1000 nm or less, preferably 500 nm or less.

[0639] On the other hand, if transparency is not required, the thickness of the anode 2 can be any thickness as long as the required strength is needed. In this case, the anode 2 can be the same thickness as the substrate.

[0640] When forming other layers on the surface of anode 2, impurities on anode 2 are removed by performing treatments such as ultraviolet / ozone, oxygen plasma, and argon plasma before film formation, and its ionization potential is adjusted to improve hole injection.

[0641] [Hollow Injection Layer]

[0642] The layer that functions to transport holes from the anode 2 side to the light-emitting layer 5 side is generally referred to as a hole injection transport layer or hole transport layer. Furthermore, when there are two or more layers that function to transport 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 the hole injection layer 3. In terms of enhancing the function of transporting holes from the anode 2 side to the light-emitting layer 5 side, it is preferable to form a hole injection layer 3. When forming the hole injection layer 3, it is typically formed on the anode 2.

[0643] The thickness of the hole injection layer 3 is typically 1 nm or more, preferably 5 nm or more, and typically 1000 nm or less, preferably 500 nm or less.

[0644] The hole injection layer can be formed by vacuum evaporation or wet deposition. For better film formation properties, wet deposition is preferred.

[0645] The hole injection layer 3 preferably contains a hole-transporting compound, more preferably a hole-transporting compound and an electron-accepting compound. Further preferably, the hole injection layer contains a cationic radical compound, and particularly preferably, it contains both a cationic radical compound and a hole-transporting compound.

[0646] The following describes a general method for forming a hole injection layer. In the organic light-emitting element of the present invention, the hole injection layer is preferably formed by using the above-described organic light-emitting element composition by a wet film deposition method.

[0647] [Hole-transporting compounds]

[0648] The composition for forming a hole injection layer typically contains a hole transport compound that forms the hole injection layer 3.

[0649] Furthermore, in the case of wet film formation methods, solvents are typically also included. The composition for forming the hole injection layer preferably has high hole transport properties, enabling efficient transport of injected holes. Therefore, a high hole mobility is preferred, minimizing the generation of impurities that could become traps during manufacturing and use.

[0650] Furthermore, it is preferable to have excellent stability, low ionization potential, and high transparency to visible light. In particular, when the hole injection layer comes into contact with the light-emitting layer, it is preferable to prevent quenching of light emission from the light-emitting layer and to prevent the formation of excitokines with the light-emitting layer, thereby reducing the luminescence efficiency.

[0651] From the viewpoint of the charge injection barrier from the anode to the hole injection layer, compounds having an ionization potential of 4.5 eV to 6.0 eV are preferred as hole-transporting compounds. Examples of hole-transporting compounds include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds obtained by linking a tertiary amine to a fluorene group, hydrazone compounds, silazane compounds, and quinacridone compounds.

[0652] Of the exemplary compounds described above, aromatic amine compounds are preferred from the perspective of amorphousness and visible light transmittance, and aromatic tertiary amine compounds are particularly preferred. Here, aromatic tertiary amine compounds refer to compounds having an aromatic tertiary amine structure, and also include compounds having groups derived from aromatic tertiary amines.

[0653] There are no particular restrictions on the types of aromatic tertiary amine compounds. However, considering the ease with which uniform luminescence can be obtained through surface smoothing, it is preferable to use polymeric compounds (polymeric compounds with linked repeating units) with a weight-average molecular weight of 1,000 to 1,000,000.

[0654] In order to improve the conductivity of the hole injection layer by oxidizing the hole transport compound, the hole injection layer 3 preferably contains the aforementioned electron accepting compound and the aforementioned cationic radical compound.

[0655] It can also generate cationic radical compounds from polymers, such as PEDOT / PSS (Adv. Mater., 2000, Vol. 12, p. 481) and emerald green imine hydrochloride (J. Phys. Chem., 1990, Vol. 94, p. 7716), through oxidative polymerization (dehydrogenation polymerization).

[0656] The oxidative polymerization described here refers to the chemical or electrochemical oxidation of monomers in an acidic solution using peroxydisulfate or similar substances. In this case of oxidative polymerization (dehydrogenation polymerization), the monomer is polymerized through oxidation, and the anion from the acidic solution becomes a counter anion, generating a cationic free radical after removing an electron from the repeating unit of the polymer.

[0657] [Cavity injection layer formed using wet film formation method]

[0658] When forming the hole injection layer 3 using a wet film-forming method, a film-forming composition (a composition for forming the hole injection layer) is typically prepared by mixing it with a solvent (a solvent for the hole injection layer) that can dissolve the material that forms the hole injection layer. This composition for forming the hole injection layer is then coated and formed on a layer (usually the anode) that corresponds to the lower layer of the hole injection layer, and dried to form the hole injection layer.

[0659] The concentration of the hole-transporting compound in the composition for forming the hole injection layer is arbitrary as long as it does not significantly impair the effects of the present invention, but a lower concentration is preferred in terms of film thickness uniformity, while a higher concentration is preferred in terms of minimizing defects in the hole injection layer. Specifically, the concentration is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, particularly preferably 50% by mass or less.

[0660] Examples of solvents include ether solvents, ester solvents, aromatic hydrocarbon solvents, and amide solvents.

[0661] Examples of ether solvents 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.

[0662] Examples of ester solvents include phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate, and other aromatic esters.

[0663] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene.

[0664] Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide.

[0665] In addition, dimethyl sulfoxide, etc., can also be used.

[0666] The formation of the hole injection layer 3 based on a wet film-forming method is typically carried out by coating the hole injection layer formation composition onto a layer (typically the anode 2) corresponding to the lower layer of the hole injection layer 3 after preparation and drying.

[0667] Hole injection layer 3 is usually dried after film formation by heating, depressurization drying, etc.

[0668] [A hole-injection layer is formed by vacuum evaporation]

[0669] When forming the hole injection layer 3 by vacuum evaporation, typically one or more of the constituent materials of the hole injection layer 3 (such as the aforementioned hole transport compound and electron acceptor compound) are placed in a crucible placed inside a vacuum container (when using two or more materials, they are usually placed in separate crucibles), and the vacuum container is evacuated to 1000 liters using a vacuum pump. － 4 After approximately Pa, the crucible is heated (when using two or more materials, each crucible is usually heated), and the evaporation rate of the material in the crucible is controlled while the material is evaporated (when using two or more materials, the evaporation rate is usually controlled independently for each material), forming a hole injection layer on the anode of the substrate placed opposite the crucible.

[0670] It should be noted that when using more than two materials, their mixture can also be placed in a crucible and heated to evaporate and form a cavity injection layer.

[0671] The vacuum level during vapor deposition is not limited as long as it does not significantly impair the effectiveness of the invention; it is typically 0.1 × 10⁻⁶. - 6 Torr(0.13×10 －4 Pa)~9.0×10 -6 Torr(12.0×10 -4 Pa). The vapor deposition rate is not limited as long as it does not significantly impair the effectiveness of the invention; it is typically [value missing]. The film-forming temperature during vapor deposition is not limited as long as it does not significantly impair the effect of the present invention; it is preferably carried out at 10°C to 50°C.

[0672] It should be noted that the hole injection layer 3 can be cross-linked with the hole transport layer 4, which will be described later.

[0673] Hole transport layer

[0674] The hole transport layer 4 is a layer that functions to transport holes from the anode 2 side to the light-emitting layer 5 side. The hole transport layer 4 is not a necessary layer in the organic electroluminescent element of the present invention, but it is preferable to form this layer to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5. When forming the hole transport layer 4, it is typically formed between the anode 2 and the light-emitting layer 5. Alternatively, if the hole injection layer 3 described above is present, it is formed between the hole injection layer 3 and the light-emitting layer 5.

[0675] The thickness of the hole transport layer 4 is typically 5 nm or more, preferably 10 nm or more, and on the other hand, it is typically 300 nm or less, preferably 100 nm or less.

[0676] The hole transport layer 4 can be formed by vacuum evaporation or wet deposition. For better film formation properties, wet deposition is preferred.

[0677] The following describes a general method for forming a hole transport layer, but in the organic electroluminescent element of the present invention, it is preferable to use the above-described organic electroluminescent element composition to form the hole transport layer using a wet film deposition method.

[0678] Hole transport layer 4 typically contains a hole transport compound. Preferably, the aforementioned polymer or a polymer cross-linked from the aforementioned polymer is preferred as the hole transport compound contained in hole transport layer 4. In addition to the aforementioned polymer, examples of hole transport compounds include: aromatic diamines containing two or more tertiary amines and having two or more fused aromatic rings substituted for nitrogen atoms, represented by 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (Japanese Patent Application Publication No. 5-234681); aromatic amine compounds with a starburst structure, such as 4,4',4”-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., vols. 72-74, p. 985, 1997); and aromatic amine compounds composed of tetramers of triphenylamine (Chem. Com). Preferred examples include spirocyclic compounds such as 2,2',7,7'-tetra-(diphenylamino)-9,9'-spirodifluorene (Synth. Metals, Vol. 91, p. 209, 1997) and carbazole derivatives such as 4,4'-N,N'-dicarbazole biphenyl. Additionally, the hole transport layer 4 may contain, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Application Laid-Open No. 7-53953), or polyarylene ether sulfone containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, p. 33, 1996).

[0679] [A hole transport layer is formed using a wet film deposition method]

[0680] When forming a hole transport layer using a wet film deposition method, a hole transport layer forming composition is typically used instead of a hole injection layer forming composition, just as when forming the aforementioned hole injection layer using a wet film deposition method.

[0681] When forming a hole transport layer using a wet film deposition method, the hole transport layer forming composition typically further contains a solvent. The solvent used in the hole transport layer forming composition can be the same solvent used in the hole injection layer forming composition described above.

[0682] The concentration of the hole-transporting compound in the composition for forming the hole transport layer can be in the same range as the concentration of the hole-transporting compound in the composition for forming the hole injection layer.

[0683] The formation of the hole transport layer based on the wet film formation method can be carried out in the same way as the aforementioned hole injection layer film formation method.

[0684] [A hole transport layer is formed by vacuum evaporation]

[0685] When forming a hole transport layer using vacuum evaporation, the hole transport layer forming composition can usually be used instead of the hole injection layer forming composition, just as it is used when forming the hole injection layer using vacuum evaporation. The film formation conditions, such as vacuum degree, evaporation rate, and temperature, can be performed under the same conditions as those for vacuum evaporation of the hole injection layer.

[0686] [Emitting Layer]

[0687] The light-emitting layer 5 is a layer that functions to emit light by recombination of holes injected from the anode 2 and electrons injected from the cathode 9 when an electric field is provided between a pair of electrodes.

[0688] The light-emitting layer 5 is formed between the anode 2 and the cathode 9. When there is a hole injection layer on the anode, the light-emitting layer is formed between the hole injection layer and the cathode. When there is a hole transport layer on the anode, the light-emitting layer is formed between the hole transport layer and the cathode.

[0689] The thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effect of the present invention. A thicker layer is preferred in terms of reducing the likelihood of defects in the film, while a thinner layer is preferred in terms of facilitating the use of low driving voltages. Therefore, the thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and more preferably 200 nm or less, more preferably 100 nm or less.

[0690] The light-emitting layer 5 contains at least a material with light-emitting properties (light-emitting material), and preferably contains a material with charge-transporting properties (charge-transporting material).

[0691] Among them, the materials mentioned above as the light-emitting layer materials are preferred.

[0692] Alternatively, the following materials may also be used appropriately.

[0693] [Luminescent Materials]

[0694] There are no particular limitations as long as the luminescent material emits light at the desired emission wavelength without hindering the effect of the present invention; any known luminescent material can be used. The luminescent material can be a fluorescent luminescent material or a phosphorescent luminescent material, with materials having good luminescent efficiency being preferred. From the viewpoint of internal quantum efficiency, phosphorescent luminescent materials are preferred.

[0695] Examples of fluorescent materials include the following.

[0696] Examples of fluorescent materials that provide blue light emission (blue fluorescent materials) include, for example, naphthalene, perylene, pyrene, anthracene, and coumarin. p-Bis(2-phenylvinyl)benzene and their derivatives, etc.

[0697] Examples of fluorescent materials that provide green light emission include, for example, quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al(C9H6NO)3.

[0698] Examples of fluorescent materials that provide yellow light emission (yellow fluorescent materials) include, for example, rubrene and perimidone derivatives.

[0699] Examples of fluorescent materials that provide red light emission (red fluorescent materials) include, for example, DCM (4-(diacrylonitrile methylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxan derivatives, azobenzothioxan, etc.

[0700] In addition, examples of phosphorescent materials include organometallic complexes containing metals selected from groups 7 to 11 of the long-period periodic table. Preferred metals selected from groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

[0701] As ligands for organometallic complexes, preferred ligands are those formed by linking a heteroaryl group to pyridine, pyrazole, or o-phenanthroline, such as heteroarylpyridine or heteroarylpyrazole. Phenylidene pyridine ligands and phenylpyrazole ligands are particularly preferred. Here, heteroaryl refers to aryl or heteroaryl groups.

[0702] Preferred phosphorescent materials include, for example, phenylpyridine complexes such as tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, tris(2-phenylpyridine)osmium, and tris(2-phenylpyridine)rhenium, as well as porphyrin complexes such as octaethylplatinumporphyrin, octaphenylplatinumporphyrin, octaethylpalladiumporphyrin, and octaphenylpalladiumporphyrin.

[0703] Examples of polymer-based luminescent materials include poly(9,9-dioctylfluorene-2,7-diyl), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)], poly[(9,9-dioctylfluorene-2,7-diyl)-co-(1,4-benzo-2{2,1'-3}-triazole)], and polyphenylene vinylidene materials such as poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylidene].

[0704] [charge transport materials]

[0705] The charge transport material is a material that has the property of transporting positive charge (holes) or negative charge (electrons). There are no particular restrictions as long as the effect of the present invention is not impaired, and known luminescent materials can be used.

[0706] The charge transport material can be any compound that has been used in the light-emitting layer of organic electroluminescent devices, and compounds used as the main material of the light-emitting layer are particularly preferred.

[0707] Alternatively, the polymer of the present invention can also be used as the main material of the light-emitting layer.

[0708] Specifically, examples of charge transport materials include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds formed by linking tertiary amines with fluorene groups, hydrazone compounds, silazane compounds, silanamine compounds, phosphoramide compounds, and quinacridone compounds, which are examples of hole transport compounds used as hole injection layers. Furthermore, anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, and o-phenanthroline compounds are also examples. Diazole compounds, silicone compounds, and other electron-transporting compounds.

[0709] Alternatively, aromatic diamines containing two or more tertiary amines and in which two or more fused aromatic rings are substituted for nitrogen atoms, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (Japanese Patent Application Publication No. 5-234681), and aromatic amine compounds with starburst structures, such as 4,4',4”-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., Vol. 72-74, p. 985, 1997), may also be preferred (J. Lumin., Vol. 72-74, p. 985, 1997). Compounds exemplified as hole-transporting compounds of the hole transport layer include: aromatic amine compounds composed of tetramers of triphenylamine (Chem. Commun., 2175, 1996); fluorene compounds such as 2,2',7,7'-tetra-(diphenylamino)-9,9'-spirodifluorene (Synth. Metals, Vol. 91, 209, 1997); and carbazole compounds such as 4,4'-N,N'-dicarbazole biphenyl.

[0710] In addition, 2-(4-biphenyl)-5-(p-tert-butylphenyl)-1,3,4- can also be cited. diazole (tBu-PBD), 2,5-bis(1-naphthyl)-1,3,4- diazole (BND), etc. Diazole compounds, silylopadiene compounds such as 2,5-bis(6'-(2',2”-bipyridyl))-1,1-dimethyl-3,4-diphenylsiloxane (PyPySPyPy), and o-phenanthroline compounds such as BPhen and 2,9-dimethyl-4,7-diphenyl-1,10-o-phenanthroline (BCP, bath copper spirit), etc.

[0711] [The luminescent layer is formed using a wet film deposition method]

[0712] The light-emitting layer can be formed by vacuum evaporation or wet deposition. Due to its excellent film-forming properties, wet deposition is preferred, and spin coating and inkjet printing are even more preferred. In particular, when forming a hole injection layer or hole transport layer as the lower layer of the light-emitting layer using the above-mentioned organic electroluminescent element composition, it is easy to stack using wet deposition, so wet deposition is preferred.

[0713] When forming a light-emitting layer using a wet film deposition method, the light-emitting layer forming composition prepared by mixing with a solvent (a solvent for light-emitting layers) that can dissolve the material to form the light-emitting layer is usually used instead of the hole injection layer forming composition, similar to when forming the hole injection layer using a wet film deposition method.

[0714] As solvents, examples include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents used for the formation of the hole injection layer, as well as alkane-based solvents, halogenated aromatic hydrocarbon-based solvents, aliphatic alcohol-based solvents, alicyclic alcohol-based solvents, aliphatic ketone-based solvents, and alicyclic ketone-based solvents. Specific examples of solvents are given below, but are not intended to limit the invention to these examples without impairing its effectiveness.

[0715] Examples include aliphatic ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); aromatic ether solvents such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethyl anisole, 2,4-dimethyl anisole, and diphenyl ether; aromatic ester solvents such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; and toluene, xylene, mesitylene, and cyclohexylene. Aromatic hydrocarbon solvents such as benzene, tetrahydronaphthalene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; alkane solvents such as n-decane, cyclohexane, ethylcyclohexane, decahydronaphthalene, and dicyclohexane; halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; aliphatic alcohol solvents such as butanol and hexanol; alicyclic alcohol solvents such as cyclohexanol and cyclooctanol; aliphatic ketone solvents such as methyl ethyl ketone and dibutyl ketone; and alicyclic ketone solvents such as cyclohexanone, cyclooctanone, and fentanyl ketone. Alkane solvents and aromatic hydrocarbon solvents are particularly preferred.

[0716] [Cavity barrier]

[0717] A hole blocking layer 6 can be disposed between the light-emitting layer 5 and the electron injection layer 8 (described later). The hole blocking layer 6 is a layer stacked on the light-emitting layer 5 in such a way that it is in contact with the interface on the cathode 9 side of the light-emitting layer 5.

[0718] The hole blocking layer 6 has the functions of preventing holes migrating from the anode 2 from reaching the cathode 9, and efficiently transmitting electrons injected from the cathode 9 towards the light-emitting layer 5.

[0719] As for the required physical properties of the material constituting the hole blocking layer 6, examples include high electron mobility and low hole mobility, large band gap (difference between HOMO and LUMO), and high excited triplet energy level (T1).

[0720] Materials that satisfy such conditions for hole-blocking layers include, for example, mixed ligand complexes such as bis(2-methyl-8-hydroxyquinoline)(phenolic)aluminum and bis(2-methyl-8-hydroxyquinoline)(triphenylsilanolic)aluminum, metal complexes such as bis(2-methyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2-methyl-8-hydroxyquinoline)aluminum dinuclear metal complexes, styrene compounds such as stilbene biphenyl derivatives (Japanese Patent Application Publication No. 11-242996), triazole derivatives such as 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Application Publication No. 7-41759), and o-phenanthroline derivatives such as copper hydroxide (Japanese Patent Application Publication No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at positions 2, 4, or 6, as described in International Publication No. 2005 / 022962, are also preferred materials for hole-blocking layers.

[0721] There are no restrictions on the method for forming the hole blocking layer 6. Therefore, it can be formed using wet film deposition, vapor deposition, or other methods.

[0722] The thickness of the hole blocking layer 6 is arbitrary as long as it does not significantly impair the effect of the present invention. It is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[0723] [Electron transport layer]

[0724] To further improve the current efficiency of the device, an electron transport layer 7 is provided between the light-emitting layer 5 and the electron injection layer 8.

[0725] The electron transport layer 7 is formed of a compound that can efficiently transport electrons injected from the cathode 9 towards the light-emitting layer 5 between the electrodes providing the electric field. As an electron transport compound used in the electron transport layer 7, it is necessary to have high electron injection efficiency from the cathode 9 or the electron injection layer 8, high electron mobility, and the ability to efficiently transport the injected electrons.

[0726] As electron transport compounds used in electron transport layers, examples include, for instance, metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Application Publication No. 59-194393), and metal complexes of 10-hydroxybenzo[h]quinoline. Diazole derivatives, stilbene-biphenyl derivatives, silylopyrocyclopentadiene derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzo[a] Azole metal complexes, benzothiazole metal complexes, tribenzimidazolylbenzene (US Patent No. 5,645,948), quinoxaline compounds (Japanese Patent Application Publication No. 6-207,169), o-phenanthroline derivatives (Japanese Patent Application Publication No. 5-331,459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinone diimide, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, etc.

[0727] The thickness of the electron transport layer 7 is typically 1 nm or more, preferably 5 nm or more, and typically 300 nm or less, preferably 100 nm or less.

[0728] The electron transport layer 7 is formed on the hole blocking layer 6 by means of a wet film deposition method or a vacuum evaporation method, as described above. Vacuum evaporation method is usually used.

[0729] [Electron Injection Layer]

[0730] The electron injection layer 8 serves to efficiently inject electrons injected from the cathode 9 into the electron transport layer 7 or the light-emitting layer 5.

[0731] To ensure efficient electron injection, the material forming the electron injection layer 8 is preferably a metal with a low work function. Examples include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. The film thickness is preferably 0.1 nm to 5 nm.

[0732] Furthermore, in order to improve electron injection and electron transport properties while obtaining excellent film quality, it is preferable to dope organic electron transport materials with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (described in Japanese Patent Application Publication No. 10-270171, 2002-100478, and 2002-100482, etc.).

[0733] The thickness of the electron injection layer 8 is typically 5 nm or more, preferably 10 nm or more, and typically 200 nm or less, preferably 100 nm or less.

[0734] The electron injection layer 8 is formed by laminating the light-emitting layer 5 or the hole blocking layer 6 and electron transport layer 7 on it using a wet film deposition method or a vacuum evaporation method.

[0735] The details of the wet film formation method are the same as those for the aforementioned light-emitting layer.

[0736] [cathode]

[0737] The cathode 9 serves to inject electrons into the layer (electron injection layer or light-emitting layer, etc.) on the side of the light-emitting layer 5.

[0738] The cathode 9 can be made of the same material used in the anode 2 described above, but for efficient electron injection, a metal with a low work function is preferred. For example, metals such as tin, magnesium, indium, calcium, aluminum, and silver, or their alloys, can be used. Specific examples of alloys include low work function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0739] Regarding the stability of the component, it is preferable to stack a metal layer with a high work function and stability in the atmosphere on the cathode to protect the cathode, which is made of a metal with a low work function. Examples of metals that can be used for stacking include aluminum, silver, copper, nickel, chromium, gold, and platinum.

[0740] The film thickness of the cathode is usually the same as that of the anode.

[0741] [Other layers]

[0742] The organic electroluminescent element of the present invention may further have other layers, provided that the effect of the present invention is not significantly impaired. That is, any layer other than those described above may be present between the anode and the cathode.

[0743] [Other components]

[0744] The organic electroluminescent element of the present invention may also have a structure opposite to the above description, that is, a structure in which 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.

[0745] When the organic electroluminescent element of the present invention is used in an organic electroluminescent device, it can be used as a single organic electroluminescent element, or as a configuration in which multiple organic electroluminescent elements are arranged in an array, or as a configuration in which an anode and a cathode are arranged in an X-Y matrix.

[0746] <Organic EL Display Device>

[0747] The organic EL display device (organic electroluminescent element display device) of the present invention uses the above-described organic electroluminescent element. The type and structure of the organic EL display device of the present invention are not particularly limited, and it can be assembled using the above-described organic electroluminescent element according to conventional methods.

[0748] For example, the organic EL display device of the present invention can be formed using the method described in "Organic EL Display" (Ohmsha Corporation, released on August 20, 2017, written by Shizushi Tokito, Chinatsu Adachi, and Hideyuki Murata).

[0749] <Organic EL Lighting>

[0750] The organic EL lighting (organic electroluminescent element lighting) of the present invention is obtained by using the above-described organic electroluminescent element. There are no particular limitations on the type or structure of the organic EL lighting of the present invention; it can be assembled using the above-described organic electroluminescent element according to conventional methods.

[0751] Example

[0752] The following embodiments illustrate the present invention in more detail. However, the present invention is not limited to the following embodiments, and can be implemented with any modifications as long as it does not depart from its spirit.

[0753] <Synthesis of Intermediates>

[0754] [Synthesis of Compound 1]

[0755]

[0756] Under a nitrogen flow, 4-bromo-3-iodotoluene (10.6 g, 35.7 mmol), 2,5-dimethylphenylboronic acid (5.1 g, 33.9 mmol), potassium phosphate (18.0 g, 84.8 mmol), toluene (85 ml), ethanol (43 ml), and water (43 ml) were placed into a flask, and the system was heated to 60 °C to allow for complete nitrogen replacement.

[0757] Add bis(triphenylphosphine)palladium(II) dichloride (0.12 g, 0.17 mmol) and stir at 60 °C for 2 hours. Add water to the reaction mixture and extract with toluene. Dry the organic layer with anhydrous magnesium sulfate and purify crudely using activated clay. Purify the crude product by column chromatography (developing solvent: hexane) to give compound 1 (8.4 g, yield 89.8%).

[0758] [Synthesis of Compound 2]

[0759]

[0760] Under a nitrogen stream, 70 ml of N,N-dimethylacetamide, compound 1 (8.4 g, 30.5 mmol), terpentine (3.1 g, 30.5 mmol), and potassium carbonate (25.0 g, 184.1 mmol) were added to a 300 ml flask, and the mixture was stirred while being bubbled under nitrogen at 50 °C for 15 minutes. Then, a solution prepared with 20 ml of N,N-dimethylacetamide, palladium acetate Pd(OAc)2 (0.23 g, 0.92 mmol), and tricyclohexylphosphine (0.51 g, 1.83 mmol) was added, and the mixture was reacted at 150 °C for 3 hours.

[0761] 120 ml of pure water was added dropwise at room temperature, and the mixture was extracted with 120 ml of dichloromethane and dried over anhydrous magnesium sulfate. Further purification was performed by column chromatography (developing solvent: hexane) to give compound 2 (5.0 g, yield 84.3%).

[0762] [Synthesis of Compound 3]

[0763]

[0764] Under a nitrogen stream, compound 2 (5.0 g, 25.7 mmol), 30 mL of tetrahydrofuran, and potassium tert-butoxide (11.6 g, 102.9 mmol) were placed in a flask, and the system was thoroughly nitrogen-purged at room temperature. Iodomethane (11.0 g, 77.2 mmol) was slowly added dropwise, and the mixture was stirred at 40 °C for 4 hours. 150 mL of deionized water was added to the reaction mixture at room temperature, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and concentrated. Further purification was performed by column chromatography (developing solvent: hexane) to give compound 3 (4.2 g, yield 73.1%).

[0765] [Synthesis of Compound 4]

[0766]

[0767] Compound 3 (4.2 g, 18.8 mmol), iodine (0.05 g, 0.19 mmol), and 25 mL of dichloromethane were placed in a flask. A solution containing bromine (6.3 g, 39.5 mmol) was slowly added dropwise to 5 mL of dichloromethane at 0 °C. After 1 hour, ice water was added to the reaction mixture and the mixture was stirred. Sodium thiosulfate aqueous solution (0.5 g, 20 mL water) was added, and the mixture was extracted with dichloromethane. The organic layer was dried over anhydrous magnesium sulfate. Purification was performed by column chromatography (developing solvent: hexane / dichloromethane = 100 / 1) to give compound 4 (4.3 g, yield 60.2%).

[0768] [Synthesis of Compound 5]

[0769]

[0770] Under a nitrogen stream, 50 ml of dimethyl sulfoxide, compound 4 (4.3 g, 11.3 mmol), bis(pinacol)diboron (8.6 g, 33.9 mmol), and potassium acetate (6.7 g, 67.9 mmol) were added to a 200 ml flask, and the mixture was stirred at 60 °C for 30 minutes. Then, 0.92 g, 1.1 mmol of 1,1'-bis(diphenylphosphine)ferrocene-palladium(II)-dichloromethane [PdCl2(dppf)CH2Cl2] was added, and the mixture was reacted at 95 °C for 4 hours.

[0771] The reaction solution was filtered under reduced pressure by adding pure water dropwise at room temperature. The filtrate was extracted with toluene, dried over anhydrous magnesium sulfate, and crudely purified using activated clay. The crude product was further purified by column chromatography (developing solvent: hexane / ethyl acetate = 950 / 50) to give compound 5 (3.1 g, yield 57.8%).

[0772] [Synthesis of Compound 6]

[0773]

[0774] Next, compound 5 (3.1 g, 6.5 mmol), 1-bromo-4-iodobenzene (5.5 g, 19.6 mmol), potassium phosphate (2 M aqueous solution, 20 ml), toluene (40 ml), and ethanol (20 ml) were placed in a flask, and the system was heated to 60 °C after complete nitrogen replacement. Bis(triphenylphosphine)palladium(II) dichloride (0.092 g, 0.13 mmol) was added, and the mixture was stirred at 60 °C for 8 hours. Water was added to the reaction mixture, and extraction was performed with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude purified product was purified by column chromatography (developing solvent: hexane:toluene = 600:400) to give compound 6 (2.6 g, yield 74.7%).

[0775] [Synthesis of Compound 7]

[0776]

[0777] Compound 7 was synthesized using the method described in International Publication No. 2019 / 177175.

[0778] [Synthesis of Compound 9]

[0779]

[0780] Under a nitrogen stream, 50 ml of dimethyl sulfoxide, commercially available compound 8 (10.0 g, 23.04 mmol), bis(pinacol)diboron (17.5 g, 68.91 mmol), and potassium acetate (13.5 g, 137.56 mmol) were added to a 200 ml flask, and the mixture was stirred at 60 °C for 30 minutes. Then, 1,1'-bis(diphenylphosphine)ferrocene-palladium(II)-dichloromethane [PdCl2(dppf)CH2Cl2] (1.9 g, 23.27 mmol) was added, and the mixture was reacted at 95 °C for 4.5 hours.

[0781] The reaction solution was filtered under reduced pressure by adding pure water dropwise at room temperature. The filtrate was extracted with toluene, dried over anhydrous magnesium sulfate, and crudely purified using activated clay. The crude purified product was further purified by column chromatography (developing solvent: hexane / ethyl acetate = 700 / 300) to give compound 9 (8.2 g, yield 82%).

[0782] [Synthesis of Compound 10]

[0783]

[0784] Next, compound 9 (3.0 g, 6.91 mmol), 1-bromo-4-iodobenzene (7.8 g, 27.6 mmol), potassium phosphate (2 M aqueous solution, 21 ml), toluene (50 ml), and ethanol (25 ml) were placed in a flask, and the system was heated to 60 °C after complete nitrogen replacement. Bis(triphenylphosphine)palladium(II) dichloride (0.049 g, 0.07 mmol) was added, and the mixture was stirred at 60 °C for 1.5 hours. Water was added to the reaction mixture, and the mixture was extracted with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude purified product was purified by column chromatography (developing solvent: hexane:toluene = 750:250) to give compound 10 (0.6 g, yield 17.6%).

[0785] [Synthesis of Compound 11]

[0786]

[0787] Compound 11 was obtained using the same reaction conditions and purification methods as compound 10.

[0788] <Example 1>

[0789] [Synthesis of Polymer 1]

[0790] Polymer 1 was synthesized according to the following reaction formula.

[0791]

[0792] Compound 6 (2.50 g, 4.70 mmol), 2-amino-9,9-dihexylfluorene (1.15 g, 3.29 mmol), compound 7 (0.93 g, 0.95 mmol), 2-amino-9,9-dimethylfluorene (1.08 g, 5.16 mmol), sodium tert-butoxide (3.48 g, 36.21 mmol), and toluene (45 g, 52 ml) were added to the system, and the system was subjected to complete nitrogen replacement and heated to 60 °C (solution A1).

[0793] Add [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.20 g, 0.75 mmol) to a 15 mL toluene solution of tris(di-benzylacetone)palladium complex (86.0 mg, 0.094 mmol) and heat to 60 °C (solution B1).

[0794] Under a nitrogen stream, solution B1 was added to solution A1 and the mixture was heated under reflux for 1 hour. After confirming the disappearance of compound 7, compound 10 (2.50 g, 5.08 mmol) was added. After heating under reflux for 2 hours, bromobenzene (0.89 g, 5.67 mmol) was added, and the mixture was heated under reflux for another 2 hours. The reaction mixture was cooled, and 101 ml of toluene was added dropwise to an ethanol / water (550 ml / 100 ml) solution to obtain the end-capped crude polymer.

[0795] The end-capped crude polymer was dissolved in toluene, then precipitated in acetone, and the precipitated polymer was filtered off. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and then reprecipitated with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain polymer 1 (2.2 g) as the target analyte. The molecular weight of the obtained polymer 1 is as follows.

[0796] Weight-average molecular weight (Mw) = 37550

[0797] Number average molecular weight (Mn) = 30040

[0798] Dispersion (Mw / Mn) = 1.25

[0799] It should be noted that in Example 1 and other examples, standard curves were prepared using polystyrene of various molecular weights, and the molecular weight of the polymer was determined under the following conditions.

[0800] Apparatus: SHIMADZU GPC system, system control: CBM-20Alite, column oven: CTO-20A, pump: LC-20AT, detector: SPD-20AV, solvent: THF, column (manufacturer, model no.: TSKgel SupermultiporeHZ-M (4.6mm IDx150mm)).

[0801] x4μm Temperature: 40℃, Flow rate: 0.35mL / min, Injection volume and sample concentration: 10μL, 1% conc.

[0802] <Example 2>

[0803] [Synthesis of Polymer 2]

[0804] Polymer 2 was synthesized according to the following reaction formula.

[0805]

[0806] Compound 10 (1.2 g, 2.44 mmol), 2-amino-9,9-dihexylfluorene (0.21 g, 0.60 mmol), compound 7 (2.40 g, 2.44 mmol), 2-amino-9,9-dimethylfluorene (0.39 g, 1.86 mmol), sodium tert-butoxide (1.81 g, 18.83 mmol), and toluene (64 g, 73 ml) were added to the system, and the system was subjected to complete nitrogen replacement and heated to 60 °C (solution A2).

[0807] Add [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.11 g, 0.41 mmol) to an 8 mL toluene solution of tris(di-benzylacetone)dipalladium complex (0.045 g, 0.049 mmol) and heat to 60 °C (solution B2).

[0808] Under a nitrogen stream, solution B2 was added to solution A2 and the mixture was heated under reflux for 1 hour. After confirming the disappearance of compound 7, compound 6 (0.26 g, 0.49 mmol) was added. After 1 hour, compound 10 (0.804 g, 1.63 mmol) was added. After reflux for 1 hour, bromobenzene (0.5 g, 3.18 mmol) was added, and the mixture was heated under reflux for 2 hours. The cooled reaction mixture was then added dropwise to an ethanol / water (270 ml / 50 ml) solution to obtain the end-capped crude polymer.

[0809] The end-capped crude polymer was dissolved in toluene, then precipitated in acetone, and the precipitated polymer was filtered off. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and then reprecipitated with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain polymer 2 (2.3 g) as the target analyte. The molecular weight of the obtained polymer 2 is as follows.

[0810] Weight-average molecular weight (Mw) = 39600

[0811] Number average molecular weight (Mn) = 29118

[0812] Dispersion (Mw / Mn) = 1.36

[0813] <Comparative Examples 1 and 2>

[0814] Polymer 7 and polymer 11 described in International Publication No. 2019 / 177175 are used as Comparative Examples 1 and 2.

[0815]

[0816]

[0817] [Determination of excited singlet (S1) and excited triplet (T1) energy levels in polymers]

[0818] Each polymer was dissolved in 2-methyltetrahydrofuran to prepare a 0.01% (w / w) solution. The fluorescence and phosphorescence spectra of this solution sample were measured using a fluorescence spectrophotometer (Hitachi, F-4500) at an excitation wavelength of 350 nm under liquid nitrogen-based cooling conditions. The S1 and T1 energy levels were derived from the peak wavelengths of the emission peaks located on the shortest wavelength side of the obtained fluorescence and phosphorescence spectra.

[0819] The measurement results are shown in Table 1.

[0820] [Table 1]

[0821]

[0822] Examples 1 and 2 (polymers 1 and 2) have higher S1 and T1 energy levels than Comparative Examples 1 and 2 (polymers 7 and 11), indicating that quenching caused by energy transfer from the luminescent excitons to the polymer is less likely to occur in organic electroluminescent elements.

[0823] <Example 3>

[0824] [Synthesis of Polymer 3]

[0825]

[0826] Compound 6 (1.5 g, 2.82 mmol), 2-amino-9,9-dihexylfluorene (0.611 g, 1.75 mmol), compound 7 (1.11 g, 1.13 mmol), 2-amino-9,9-dimethylfluorene (0.58 g, 2.76 mmol), sodium tert-butoxide (2.09 g, 21.75 mmol), and toluene (72 g, 83 ml) were added to the system. The system was then subjected to complete nitrogen replacement and heated to 60 °C (solution A3).

[0827] Add [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.12 g, 0.45 mmol) to a 9 mL toluene solution of tris(di-benzylacetone)dipalladium complex (0.052 g, 0.056 mmol) and heat to 60 °C (solution B3).

[0828] Under a nitrogen stream, solution B3 was added to solution A3 and the mixture was heated under reflux for 1 hour. After confirming the disappearance of compound 6, compound 6 (1.34 g, 2.51 mmol) was added. After heating under reflux for 2 hours, bromobenzene (0.49 g, 3.12 mmol) was added, and the mixture was heated under reflux for 1 hour. The cooled reaction mixture was then added dropwise to an ethanol / water (270 ml / 50 ml) solution to obtain the end-capped crude polymer.

[0829] The end-capped crude polymer was dissolved in toluene, then precipitated in acetone, and the precipitated polymer was filtered off. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and then reprecipitated with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain polymer 3 (2.0 g) as the target analyte. The molecular weight of the obtained polymer 3 is as follows.

[0830] Weight-average molecular weight (Mw) = 42000

[0831] Number average molecular weight (Mn) = 31579

[0832] Dispersion (Mw / Mn) = 1.33

[0833] The following method is used to fabricate organic electroluminescent elements.

[0834] An anode was formed by depositing a 50 nm thick transparent conductive indium tin oxide (ITO) film on a glass substrate (manufactured by GEOMATEC, sputtered film). This film was then patterned with 2 mm wide stripes using conventional photolithography and hydrochloric acid etching. The substrate with the ITO pattern was then subjected to a series of steps: ultrasonic cleaning with a surfactant aqueous solution, rinsing with ultrapure water, ultrasonic cleaning with ultrapure water, rinsing with ultrapure water, drying with compressed air, and finally ultraviolet ozone cleaning.

[0835] As a composition for forming a hole injection layer, a composition is prepared by dissolving 3.0% by mass of a hole-transporting polymeric compound having a repeating structure of the following formula (P-1) and 0.6% by mass of an electron-accepting compound (HI-1) in ethyl benzoate.

[0836]

[0837] The solution was spin-coated onto the substrate in the atmosphere and dried in the atmosphere at 240°C for 30 minutes using a hot plate to form a uniform thin film with a thickness of 40 nm, which served as a hole injection layer.

[0838] Next, the polymer of the present invention (polymer 3) having the following structural formula is dissolved in 1,3,5-trimethylbenzene to prepare a 2.0% by mass solution.

[0839] The solution was spin-coated onto a substrate with the hole injection layer coated thereon in a nitrogen glove box, and dried at 230°C for 30 minutes using a hot plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm, which serves as the hole transport layer.

[0840]

[0841] Subsequently, as materials for the light-emitting layer, a compound having the following structure (H-1) at a concentration of 1.2% by mass, a compound having the following structure (H-2) at a concentration of 1.2% by mass, a compound having the following structure (H-3) at a concentration of 0.8% by mass, and a compound having the following structure (D-1) at a concentration of 1.0% by mass are dissolved in cyclohexylbenzene to prepare a composition for forming the light-emitting layer.

[0842]

[0843] The solution was spin-coated onto a substrate with the hole transport layer coated thereon in a nitrogen glove box, and dried at 120°C for 20 minutes using a hot plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm, which served as the light-emitting layer.

[0844] The substrate to which the light-emitting layer is formed is placed in a vacuum evaporation apparatus, and the air inside the apparatus is evaporated to a pressure of 2×10⁻⁶. -4 Below Pa.

[0845] Next, the following structural formula (ET-1) and lithium 8-hydroxyquinoline were co-deposited on the light-emitting layer using a vacuum evaporation method at a film thickness ratio of 2:3 to form an electron transport layer with a film thickness of 30 nm.

[0846]

[0847] Next, a 2mm wide striped shadow mask, used as a cathode evaporation mask, is bonded to the substrate in a manner orthogonal to the ITO stripes of the anode. Aluminum is heated using a molybdenum boat to form an aluminum layer with a film thickness of 80nm, thus forming the cathode. This yields an organic electroluminescent device with a light-emitting area of ​​2mm × 2mm.

[0848] <Comparative Example 3>

[0849] A hole transport layer is formed by dissolving a polymeric compound having the following structural formula (HT-2) in 1,3,5-trimethylbenzene. Otherwise, an organic electroluminescent element is fabricated in the same manner as in Example 3.

[0850]

[0851] Synthesis of HT-2

[0852]

[0853] Compound 11 (2.5 g, 4.96 mmol), 2-amino-9,9-dihexylfluorene (0.683 g, 1.95 mmol), compound 7 (1.95 g, 1.98 mmol), 2-amino-9,9-dimethylfluorene (1.25 g, 5.98 mmol), sodium tert-butoxide (3.76 g, 38.19 mmol), and toluene (45 g, 52 ml) were added to the system. The system was then subjected to complete nitrogen replacement and heated to 60 °C (solution A4).

[0854] Add [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.211 g, 0.79 mmol) to a 16 mL toluene solution of tris(di-benzylacetone)dipalladium complex (0.091 g, 0.099 mmol) and heat to 60 °C (solution B4).

[0855] Under a nitrogen stream, solution B4 was added to solution A4 and the mixture was heated under reflux for 1 hour. After confirming the disappearance of compound 11, compound 11 (2.15 g, 4.26 mmol) was added. After heating under reflux for 2 hours, bromobenzene (0.55 g, 3.50 mmol) was added, and the mixture was heated under reflux for 1 hour. The reaction mixture was cooled, and 88 g of toluene was added to dilute the reaction mixture before it was added dropwise to an ethanol / water (300 ml / 50 ml) solution to obtain the end-capped crude polymer.

[0856] The end-capped crude polymer was dissolved in toluene, then precipitated in acetone, and the precipitated polymer was filtered off. The resulting polymer was dissolved in toluene, washed with dilute hydrochloric acid, and then reprecipitated with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain HT-2 (3.2 g) as the target analyte. The molecular weight of the obtained HT-2 is as follows.

[0857] Weight-average molecular weight (Mw) = 39600

[0858] Number average molecular weight (Mn) = 28905

[0859] Dispersion (Mw / Mn) = 1.37

[0860] [Evaluation of Organic Electroluminescent Devices]

[0861] The organic electroluminescent elements obtained in Example 3 and Comparative Example 3 were measured at 1000 cd / m². 2The voltage, current luminous efficiency (cd / A), and external quantum efficiency (EQE (%)) during emission were measured. The relative voltage was obtained by subtracting the voltage of Comparative Example 3 from the voltage of Example 3. The relative current luminous efficiency of Example 3 was obtained by setting the current luminous efficiency of Comparative Example 3 to 100. The external quantum efficiency (EQE (%)) of Example 3 was calculated by setting the external quantum efficiency (EQE (%)) of Comparative Example 3 to 100, and this was obtained as the relative EQE. These measurement results are shown in Table 2.

[0862] [Table 2]

[0863]

[0864] The results in Table 2 show that high-performance elements can be obtained in the organic electroluminescent elements of the present invention.

[0865] [Confirming the S1 and T1 energy levels through calculations]

[0866] The S1 and T1 energy levels of structural units 1 to 9 in the following model were confirmed by calculation.

[0867] Calculation Method: The T1 and S1 energy levels were calculated using Gaussian 09, Revision B.01 software. Density functional theory was employed as the quantum chemical calculation method, using B3LYP as the functional and 6-31G as the basis function. The ground state structure optimization calculation and functional were performed using B3LYP, with 6-31G as the basis function. * Perform structural optimization calculations in the ground state.

[0868] Gaussian 09, Revision B.01

[0869] M.J.Frisch, G.W.Trucks, H.B.Schlegel, G.E.Scuseria, M.A.Robb, J.R.Cheeseman, G.Scalmani, V.Barone, B.Mennucci, G.A.Petersson, H.Nakatsuji, M.Caricato, X.Li, H.P.Hratchian, A.F.Izmaylov, J.Bloino, G.Zheng, J.L.Sonnenberg, M.Hada, M.Ehara, K.Toyota, R.Fukuda, J.Hasegawa, M.Ishida, T.Nakajima, Y.Honda, O.Kitao, H.Nakai, T.Vreven, J.A.Montgomery, Jr., J.E.Peralta, F.Ogliaro, M.Bearpark, J.J.Heyd, E.Brothers, K.N.Kudin, V.N.Staroverov, T.Keith, R.Kobayashi, J.Normand, K.Raghavachari, A.Rendell, J.C.Burant, S.S.Iyengar, J.Tomasi, M.Cossi, N.Rega, J.M.Millam, M.Klene, J.E.Knox, J.B.Cross, V.Bakken, C.Adamo, J.Jaramillo, R.Gomperts, R.E.Stratmann, O.Yazyev, A.J.Austin, R.Cammi, C.Pomelli, J.W.Ochterski, R.L.Martin, K.Morokuma, V.G.Zakrzewski, G.A.Voth, P.Salvador, J.J.Dannenberg, S.Dapprich, A.D.Daniels, O.Farkas, J.B.Foresman, J.V.Ortiz, J.Cioslowski, and D.J.Fox, Gaussian, Inc., Wallingford CT, 2010.

[0870]

[0871] The T1 and S1 energy level results of this calculation are shown in Table 3.

[0872] [Table 3]

[0873]

[0874] In units 1 and 2, by introducing methyl groups as substituents at positions 3 and 6 or positions 1 and 8 of fluorene, a further twisted structure is formed by the steric hindrance of the adjacent bonded fluorene and phenylene gene substituents compared to unit 4, which does not have substituents at positions 1, 3, 6, and 8 of fluorene.

[0875] On the other hand, fluorene does not have substituents at positions 1, 3, 6, and 8, and the carbon atom adjacent to the phenylene bonded to the fluorene has a methyl group. The twisted structure, i.e., unit 3, also forms a twisted structure in the same way as units 1 and 2.

[0876] However, it was unexpectedly discovered that even though they both have torsion, units 1 and 2, which are the structures of this invention, have a higher S1 energy level than unit 3, which is good.

[0877] Furthermore, it is known that unit 2 has a higher T1 energy level than unit 1 and unit 3, which is good.

[0878] Furthermore, in the polymer of the present invention, the nitrogen atom of the amine adjacent to the main chain is preferably a monocyclic ring, i.e., a phenylene ring. In this case, the phenylene ring is further preferably unsubstituted. In the main chain of the polymer of the present invention, the structure adjacent to the nitrogen atom of the amine is a monocyclic ring, which has higher S1 and T1 energy levels than a fused ring. Therefore, it is believed that organic electroluminescent devices formed by connecting a hole transport layer containing the polymer of the present invention to a light-emitting layer have higher luminous efficiency.

[0879] To verify the above, assume that R is in the structure represented by equation (A) as the model structure. 1 and R 2 or R 51 and R 52 In the case of methyl or hydrogen, and Ar 20 This includes the case of a divalent group of fluorene as a fused ring, a divalent group of biphenyl bonded with two phenylene groups, or a phenylene group.

[0880] As a specific structure, the T1 and S1 energy levels of the structures of units 5 to 9 are calculated. It should be noted that the unit structure (1) in equation (A) is the structure contained in the repeating structure represented by the above equation (1).

[0881] The results of the T1 and S1 energy levels calculated in this study are shown in Table 4.

[0882]

[0883]

[0884] [Table 4]

[0885]

[0886] As Ar 20 Based on the comparison between unit 6 and unit 5, and between unit 8 or unit 9 and unit 7, it can be seen that: compared to the structure of nitrogen atom bonded to the main chain being a divalent group of fluorene as a fused ring, when the structure of nitrogen atom bonded to the main chain is a divalent group of biphenyl as a monocyclic ring or a phenylene, the T1 energy level and S1 energy level are higher, which is better.

[0887] Additionally, Ar 20 When comparing unit 6, which is a divalent group of biphenyl, with unit 8, the R of fluorene, which is part of the structure of unit structure (1), is different. 1 and R 2 R is a methyl group with a phenylene backbone. 51 and R 52 The structure of unit 6 for hydrogen and R of fluorene as part of unit structure (1) 1 and R 2 R is a hydrogen-containing phenylene group with a main chain. 51 and R 52 Compared to the structure of unit 8 of the methyl group, S 1 The energy level is higher, which is considered good.

[0888] Ar 20 A comparison of unit 5 and unit 7 of the divalent group of fluorene also shows that the S1 energy level is higher in unit 5, which is better. Furthermore, it can be seen that Ar... 20 The structure of unit 9, which is a phenylene group, is similar to that of Ar. 20 Compared to unit 6, which is a divalent group of biphenyl, the T1 energy level is higher and therefore better.

[0889] The present invention has been described in detail with reference to specific embodiments. It will be clear to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2020-157856, filed on September 18, 2020, the contents of which are incorporated herein by reference.

[0890] Symbol explanation.

[0891] 1.Substrate

[0892] 2. Anode

[0893] 3. Hole injection layer

[0894] 4. Hole transport layer

[0895] 5. Emissive layer

[0896] 6. Cavity barrier layer

[0897] 7. Electron transport layer

[0898] 8. Electron injection layer

[0899] 9. Cathode

[0900] 10. Organic electroluminescent elements

Claims

1. A polymer comprising repeating units represented by the following formula (1), When multiple repeating units represented by equation (1) are connected and repeated, the polymer has a repeating unit structure represented by the following equations (1)-2, or When a structure other than that in Equation (1) is bonded next to N of the repeating unit represented by Equation (1), the polymer has a partial structure represented by Equations (1)-3 below. In equation (1), Ar 1 This refers to an aromatic hydrocarbon group having 6 to 60 monovalent carbon atoms that may have substituents, an aromatic heterocyclic group having 3 to 60 monovalent carbon atoms that may have substituents, or a monovalent group formed by directly or indirectly connecting multiple groups selected from aromatic hydrocarbon groups having 6 to 60 monovalent carbon atoms and aromatic heterocyclic groups having 3 to 60 monovalent carbon atoms that may have substituents. Ar 2 and Ar 3 Each can independently represent an aromatic hydrocarbon group with 6 to 60 divalent carbon atoms that may have substituents, or a divalent group formed by the direct or intermediate connection of multiple aromatic hydrocarbon groups with 6 to 60 carbon atoms in the main chain direction, either with substituents. X represents -C(R) 7 (R) 8 )-、-N(R 9 ) - or - C(R) 10 (R) 11 ) - C(R 12 (R) 13 ) -, R 1 ~R 8 Each can independently represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms that may have substituents, or an aralkyl group having 5 to 60 carbon atoms that may have substituents. R 1 and R 2 Together, or, R 5 and R 6 Together they are alkyl groups having 1 to 24 carbon atoms that may have substituents, or aralkyl groups having 5 to 60 carbon atoms that may have substituents. R 9 ~R 13 Each can independently represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms that may have substituents, an alkoxy group having 1 to 24 carbon atoms that may have substituents, an aralkyl group having 5 to 60 carbon atoms that may have substituents, or an aromatic hydrocarbon group having 6 to 60 carbon atoms that may have substituents. n represents an integer from 1 to 3; In equation (1)-2, Ar 1 , Ar 2 , Ar 3 , R 1 to R 6 , X, n represent Ar in formula (1) 1 , Ar 2 , Ar 3 , R 1 to R 6 , X, n, n62 and n63 are both 4. Multiple R 62 Each independently of R in equation (1) 1 same, Multiple R 63 Each independently of R in equation (1) 1 same, in, Ar 2 For equation (1) - 4 and Ar 3 For equation (1) - 5, In equation (1)-4, * indicates the key in the main chain. Ar 32 For Ar from the above equation (1) 2 Remove Ar 2 The remaining structure, which includes nitrogen atoms bonded to the main chain of formula (1) and may have substituents such as phenylene, wherein Ar 2 When Ar is a phenylene group that can have substituents, 32 Indicates direct bonding. In equation (1)-5, * indicates the key in the main chain. Ar 33 For Ar from the above equation (1) 3 Remove Ar 3 The remaining structure, which may have substituents, is directly bonded to the adjacent repeating unit of the repeating unit represented by formula (1), wherein Ar 3 When Ar is a phenylene group that can have substituents, 33 Indicates direct bonding; In equation (1)-3, Q indicates that it can have R 61 The phenylene is part or all of the structure of the N-repeating unit represented by formula (1) that is directly bonded to it. Ar 1 Ar 2 Ar 32 R 1 ~R 6 R 62 X, n, n62 and Ar in equation (1)-2 1 Ar 2 Ar 32 R 1 ~R 6 R 62 X, n, and n62 are the same. Ar 3 Ar in equation (1) 3 same, n61 is 4. Multiple R 61 Each independently of R in equation (1) 1 same, Among them, Ar 2 Equation (1) - 4.

2. The polymer according to claim 1, wherein, In equation (1)-3, R 62 For hydrogen atoms, in formula (1)-2, R 62 and / or R 63 It is a hydrogen atom.

3. The polymer according to claim 1, wherein, In equation (1)-3, R 61 and R 62 For hydrogen atoms, in formula (1)-2, R 62 and R 63 It is a hydrogen atom.

4. The polymer according to claim 1, wherein, The formula (1) is represented by either formula (2)-1 or formula (2)-2. In equation (2)-1 or equation (2)-2, Ar 1 R 1 ~R 6 X is defined in the same way as in equation (1). R 20 ~R 23 Each independently with R 1 same, g, h, and i each independently represent integers from 1 to 3. j and k each independently represent integers from 1 to 2.

5. The polymer according to claim 1, wherein, It further includes at least one of the repeating units represented by equation (3)-1 and the repeating units represented by equation (3)-2. In equation (3)-1 or equation (3)-2, Ar 4 Each repeating unit independently represents an aromatic hydrocarbon group having 6 to 60 monovalent carbon atoms that may have substituents, an aromatic heterocyclic group having 3 to 60 monovalent carbon atoms that may have substituents, or a monovalent group formed by multiple groups selected from aromatic hydrocarbon groups having 6 to 60 monovalent carbon atoms that may have substituents and aromatic heterocyclic groups having 3 to 60 monovalent carbon atoms that may have substituents, either directly or indirectly linked by a linking group. X 30 Represents -C(R) 37 (R) 38 )-、-N(R 39 ) - or - C(R) 40 (R) 41 ) - C(R 42 (R) 43 ) -, R 33 R 34 R 37 R 38 R 120 ~R 123 Each can independently represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms that may have substituents, or an aralkyl group having 5 to 60 carbon atoms that may have substituents. R 39 ~R 43 Each can independently represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms that may have substituents, an alkoxy group having 1 to 24 carbon atoms that may have substituents, an aralkyl group having 5 to 60 carbon atoms that may have substituents, or an aromatic hydrocarbon group having 6 to 60 carbon atoms that may have substituents. g 3 h 3 i 3 Each can independently represent an integer from 1 to 3. j 3 k 3 Each can independently represent an integer from 1 to 2.

6. The polymer according to claim 1, wherein, Ar 1 It is represented by the following formula (A1), In formula (A1), Ar 6 and Ar 7 Each can independently represent an aromatic hydrocarbon group having 6 to 60 substituents, an aromatic heterocyclic group having 3 to 60 substituents, or a divalent group formed by multiple groups selected from aromatic hydrocarbon groups having 6 to 60 substituents and aromatic heterocyclic groups having 3 to 60 substituents, either directly or indirectly linked by a linking group. Ar 8 This refers to an aromatic hydrocarbon group having 6 to 60 monovalent carbon atoms that may have substituents, an aromatic heterocyclic group having 3 to 60 monovalent carbon atoms that may have substituents, or a monovalent group formed by directly or indirectly connecting multiple groups selected from aromatic hydrocarbon groups having 6 to 60 monovalent carbon atoms and aromatic heterocyclic groups having 3 to 60 monovalent carbon atoms that may have substituents. Ar 9 Represents a hydrogen atom or a substituent. -* indicates the bonding position with the nitrogen atom in the formula (1).

7. The polymer according to claim 6, wherein, The Ar 6 and Ar 7 The aromatic hydrocarbon group having 6 to 60 substituents and the aromatic heterocyclic group having 3 to 60 substituents are divalent groups of benzene ring, naphthalene ring, fluorene ring, indole ring, pyridine ring or triazine ring, or are divalent groups formed by connecting multiple structures selected from the divalent groups.

8. The polymer according to claim 6, wherein, The Ar 8 This represents a structure selected from the following: a-1~a-4, b-1~b-6, d-1~d-13, e-1~e-4, and f-1~f-4. In the compound group, "-*" indicates a similarity to Ar. 7 When multiple "-*" symbols exist, one of them represents a key, R 30 and R 31 Each can independently represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms that may have substituents, an alkoxy group having 1 to 24 carbon atoms that may have substituents, or an aralkyl group having 5 to 60 carbon atoms that may have substituents.

9. The polymer according to claim 5, wherein, Ar 4 It is represented by the following formula (A2), In formula (A2), Ar 36 and Ar 37 Each can independently represent an aromatic hydrocarbon group having 6 to 60 substituents, an aromatic heterocyclic group having 3 to 60 substituents, or a divalent group formed by multiple groups selected from aromatic hydrocarbon groups having 6 to 60 substituents and aromatic heterocyclic groups having 3 to 60 substituents, either directly or indirectly linked by a linking group. Ar 38 This refers to an aromatic hydrocarbon group having 6 to 60 monovalent carbon atoms that may have substituents, an aromatic heterocyclic group having 3 to 60 monovalent carbon atoms that may have substituents, or a monovalent group formed by directly or indirectly connecting multiple groups selected from aromatic hydrocarbon groups having 6 to 60 monovalent carbon atoms and aromatic heterocyclic groups having 3 to 60 monovalent carbon atoms that may have substituents. Ar 39 Represents a hydrogen atom or a substituent. -* indicates the bonding position with the nitrogen atom in formula (3)-1 or formula (3)-2.

10. The polymer according to claim 9, wherein, The Ar 36 and Ar 37 The aromatic hydrocarbon group with 6 to 60 divalent carbon atoms that may have substituents and the aromatic heterocyclic group with 3 to 60 divalent carbon atoms that may have substituents are divalent groups of benzene ring, naphthalene ring, fluorene ring, indole ring, pyridine ring or triazine ring that may have substituents, or are divalent groups formed by connecting multiple structures selected from the divalent groups.

11. The polymer according to claim 9, wherein, The Ar 38 This represents a structure selected from the following: a-1~a-4, b-1~b-6, d-1~d-13, e-1~e-4, and f-1~f-4. In the compound group, "-*" indicates a similarity to Ar. 37 When multiple "-*" symbols exist, one of them represents a key, R 30 and R 31 Each can independently represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms that may have substituents, an alkoxy group having 1 to 24 carbon atoms that may have substituents, or an aralkyl group having 5 to 60 carbon atoms that may have substituents.

12. The polymer according to claim 1, wherein, R 1 and R 2 Each can independently represent an alkyl group having 1 to 24 carbon atoms that may have substituents, or an aralkyl group having 5 to 60 carbon atoms that may have substituents.

13. The polymer according to claim 1, wherein, The R 1 and R 2 Each can be independently represented as methyl, ethyl, n-propyl, 4-phenyl-1-n-butyl, 1-methyl-1-phenylethyl, or 6-phenyl-1-n-hexyl.

14. The polymer according to claim 1, wherein, The Ar 2 This indicates that it can have substituents such as phenylene, biphenyl, or terphenyl.

15. The polymer according to claim 1, wherein, The polymer has crosslinking groups as substituents.

16. The polymer according to claim 1, wherein, The weight-average molecular weight (Mw) is above 10,000, and the dispersion (Mw / Mn) is below 3.

5.

17. A composition for an organic electroluminescent element comprising the polymer according to any one of claims 1 to 16.

18. 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 is provided between the anode and the cathode. The manufacturing method comprises the following steps: forming the organic layer using the composition for organic electroluminescent elements according to claim 17 via a wet film deposition method.

19. The method for manufacturing an organic electroluminescent element according to claim 18, wherein, The organic layer has at least one of a hole injection layer and a hole transport layer.

20. The method for manufacturing an organic electroluminescent element according to claim 19, wherein, The space between the anode and the cathode comprises the hole injection layer, the hole transport layer, and the light-emitting layer. The organic layer has the hole injection layer, the hole transport layer, and the light-emitting layer.

21. An organic electroluminescent element comprising a layer containing the polymer of any one of claims 1 to 16, or a polymer obtained by crosslinking said polymer.

22. An organic EL display device comprising the organic electroluminescent element as described in claim 21.

23. An organic EL lighting device comprising the organic electroluminescent element of claim 21.

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