Organic electroluminescent element, organic EL display device, and organic EL lighting

Abstract

This invention provides an organic electroluminescent element having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate. The organic layer has a hole transport layer and a light-emitting layer adjacent to the hole transport layer. At least one material contained in the hole transport layer and at least one material contained in the light-emitting layer have the same partial structure A as shown in the following formula (31). The ring HA is a monocyclic or an aromatic heterocyclic ring with 2 to 6 fused rings and may have substituents. 0 It is a monovalent group consisting of two or more groups selected from aromatic hydrocarbon groups that may have substituents, aromatic heterocyclic groups that may have substituents, or aromatic hydrocarbon groups that may have substituents connected together. n1 is 0 or Ar is attached to the ring HA. 0 The number of substitutions that can be performed is an integer.

Description

Technical Field

[0001] This invention relates to an organic electroluminescent element, an organic EL display device having the organic electroluminescent element, and organic EL lighting. Background Technology

[0002] Methods for forming the organic layer in organic electroluminescent devices include vacuum evaporation and wet deposition. Vacuum evaporation facilitates layer stacking and thus offers advantages such as improved charge injection from the anode and / or cathode and easy encapsulation of excitons within the light-emitting layer. On the other hand, wet deposition offers advantages such as the elimination of the need for vacuum processes, ease of large-area application, and the ability to easily form layers containing various functional materials using a coating solution composed of a mixture of multiple materials.

[0003] However, wet film deposition is difficult to stack, so compared with components obtained by vacuum evaporation, the driving stability is poor, and except for a few, it has not reached the practical level.

[0004] For the purpose of lamination using a wet film-forming method, a charge-transporting polymer with crosslinking groups is desired, and its development is underway. For example, Patent Document 1 discloses an organic EL fabricated by laminating multiple layers using a wet film-forming method.

[0005] Patent Document 1: International Publication No. 2013 / 080696

[0006] However, the lamination process using conventional wet film deposition methods presents challenges in terms of hole transport efficiency between layers, such as between the light-emitting layer and the hole transport layer.

[0007] Patent Document 1 discloses a host compound as the light-emitting layer. From the viewpoint of charge transport, a host compound having a structure common to the compound constituting the hole transport layer is preferred. However, the disclosed structure is only a very small part, and it is not clear what other structures can achieve this effect. In addition, there is still room for research regarding the overall effect of the organic electroluminescent element, such as brightness and driving lifetime. Summary of the Invention

[0008] The objective of this invention is to provide an organic electroluminescent element with high brightness and long driving life.

[0009] The inventors have discovered that in an organic electroluminescent element having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, the organic layer has a hole transport layer and a light-emitting layer adjacent to the hole transport layer, and both the materials contained in the hole transport layer and the materials contained in the light-emitting layer have a specific structure as part of the structure, thereby improving the performance of the organic electroluminescent element. The specific structure is an electron-withdrawing structure and contains a single ring or an aromatic heterocycle with 2 to 6 fused rings.

[0010] The main idea of ​​this invention is as shown in [1] to

[19] below.

[0011] [1] An organic electroluminescent element has an anode, a cathode and an organic layer between the anode and the cathode on a substrate, wherein the organic layer has a hole transport layer and a light-emitting layer adjacent to the hole transport layer, and at least one of the materials contained in the hole transport layer and at least one of the materials contained in the light-emitting layer have the same partial structure A as shown in the following formula (31).

[0012]

[0013] (In formula (31),

[0014] Cyclic HA represents a monocyclic or 2-6 fused rings of aromatic heterocyclic compounds that may have substituents.

[0015] The benzene ring in formula (31) may have substituents.

[0016] Ar 0 It represents an aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0017] n1 represents 0 or Ar on ring HA. 0 The number of substitutions that can be performed is an integer.

[0018] When n1 is 2 or more, multiple Ar 0 (They can be the same or different)

[0019] [2] According to the organic electroluminescent element of [1], at least one of the material containing partial structure A in the hole transport layer and the material containing partial structure A in the light-emitting layer has two or more partial structures A.

[0020] [3] The organic electroluminescent element according to [1] or [2], wherein the partial structure A shown in the above formula (31) is the structure shown in any of the following formulas (33) to (35).

[0021]

[0022] (In equations (33) to (35),)

[0023] Ar 0 n1 and Ar in equation (31) 0 The meanings of n1 and n2 are the same. The benzene ring in formulas (33) to (35) can have substituents.

[0024] X and Y each independently represent a C atom or an N atom.

[0025] When X and Y are C atoms, Ar0 can form bonds.

[0026] [4] According to the organic electroluminescent element described in [3], in the partial structure shown in the above formula (35), X and Y are N atoms.

[0027] [5] An organic electroluminescent element according to any one of [1] to [4], wherein the material containing partial structure A in the hole transport layer is a polymer compound having repeating units as shown in the following formula (1).

[0028]

[0029] (In formula (1),)

[0030] A represents a partial structure A.

[0031] G represents an aromatic hydrocarbon group that can have substituents, or an N atom.

[0032] Ar 2 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 via a linking group of two or more groups selected from divalent aromatic hydrocarbon groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents.

[0033] Ar 20 (This refers to a divalent aromatic hydrocarbon group that is directly bonded, may have substituents, or is a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups that may have substituents.)

[0034] [6] According to the organic electroluminescent element of [5], wherein G is a group composed of any one of a benzene ring that may have a substituent, a fluorene ring that may have a substituent, or a spirofluorene ring that may have a substituent.

[0035] [7] The organic electroluminescent element according to [5], wherein the above-mentioned G is an N atom.

[0036] [8] According to the organic electroluminescent element of [7], the repeating unit shown in the above formula (1) is any of the repeating units shown in formulas (2)-1 to (2)-3 below.

[0037]

[0038] (In equations (2)-1 to (2)-3,

[0039] A has the same meaning as A in the above formula (1).

[0040] Q represents -C(R) 5 (R) 6 )-、-N(R 7 - or -C(R) 11 (R) 12 )-C(R 13 (R) 14 )-.

[0041] R 1 ~R 4 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.

[0042] R 5 ~R 7 and R 11 ~R 14 Each can independently represent 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.

[0043] a and b are each independent integers from 0 to 4.

[0044] c1 to c5 are each an independent integer from 0 to 3.

[0045] Among them, at least one of c3 and c5 is 1 or more.

[0046] d1 to d4 are each an independent integer from 1 to 4.

[0047] There are multiple R in this repeating unit 1 R 2 R 3 R 4 At that time, R 1 R 2 R 3 R 4 (They can be the same or different)

[0048] [9] An organic electroluminescent element according to any one of [5] to [8], wherein -Ar in the above formula (1)20 -A is represented by the following formula (15).

[0049]

[0050] (In formula (15),)

[0051] X and Y each independently represent a C atom or a N atom. A ring with X, Y, and N is equivalent to ring HA in equation (31).

[0052] Ar 1 It refers to a divalent aromatic hydrocarbon group that may have substituents, or a divalent group formed by connecting multiple divalent aromatic hydrocarbon groups that may have substituents.

[0053] Ar 3 Ar 4 Each can independently represent an aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0054] Among them, in Ar 1 Ar 3 Ar 4 In at least one of them, the structure bonded to the cyclic HA is a benzene ring.

[0055] * indicates the bonding site with G)

[0056]

[10] According to the organic electroluminescent element described in [9], wherein -Ar in the above formula (1) 20 -A is represented by the following formula (16).

[0057]

[0058] (In formula (16),)

[0059] X, Y, and * have the same meaning as X, Y, and * in the above formula (15).

[0060] A ring with X, Y and N is equivalent to the ring HA in the same way as equation (15).

[0061] Ar 1’ This indicates direct bonding or Ar in equation (15) above. 1 The residues that are bonded to the cyclic HA when the structure is a benzene ring.

[0062] Ar 3’ Ar 4’ Represents a hydrogen atom or Ar in equation (15) above. 3 Ar 4(The residues that are bonded to the HA ring when the structure is a benzene ring)

[0063]

[11] An organic electroluminescent element according to any one of [5] to

[10] , wherein the material containing partial structure A in the hole transport layer further has repeating units as shown in the following formula (3).

[0064]

[0065] (In formula (3),)

[0066] Ar 13 This indicates an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents but does not contain part of structure A.

[0067] Ar 14 This 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 via a linking group of two or more groups selected from divalent aromatic hydrocarbon groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents.

[0068]

[12] The organic electroluminescent element according to [1] to

[11] , wherein the light-emitting layer comprises a low molecular weight compound having the above-described partial structure A, wherein the low molecular weight compound is a compound with a molecular weight of 5,000 or less as shown in any of the following formulas (10) to (12).

[0069]

[0070] (In equations (10) to (12),

[0071] A represents the aforementioned partial structure A.

[0072] B represents a single bond or any partial structure.

[0073] na, nb, and nc represent integers from 1 to 5.

[0074] When na, nb, and nc are 2 or more, multiple A, B, and AB can be the same or different.

[0075]

[13] According to the organic electroluminescent element of

[12] , the low molecular weight compound represented by the above formula (10) is represented by the following formula (10A).

[0076]

[0077] (In formula (10A),

[0078] HA represents any of the trivalent aromatic heterocyclic groups shown in the following structural formulas (10A-a), (10A-b), and (10A-c).

[0079] Xa 1 Ya 1 and Za 1 Each can independently represent a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or a divalent aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0080] Xa 2 Ya 2 and Za 2 Each can independently represent a hydrogen atom, an aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or an aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0081] g11, h11, and j11 each independently represent integers from 0 to 6.

[0082] At least one of g11, h11, and j11 is an integer greater than or equal to 1.

[0083] When g11, h11, and j11 are 2 or higher, Xa 1 Ya 1 Za 1 They can be the same or different.

[0084] R 31 Represents a hydrogen atom or substituent, 4 Rs 31 (They can be the same or different)

[0085]

[0086] (In equations (10A-a) to (10A-c), * indicates the bonding position)

[0087]

[14] According to the organic electroluminescent element of

[13] , the low molecular weight compound represented by the above formula (10) is represented by the following formulas (10A-1) to (10A-3).

[0088]

[0089] (In formulas (10A-1) to (10A-3),

[0090] Xa 1 Ya 1 Za 1 Xa 2 Ya 2 Za 2 With Xa in equation (10) 1Ya 1 Za 1 Xa 2 Ya 2 Za 2 They have the same meaning.

[0091] R 33 Represents a hydrogen atom or substituent, multiple R 33 They can be the same or different.

[0092] g11', h11', and j11' each independently represent integers from 0 to 5.

[0093] When g11', h11', and j11' are 2 or more, multiple Xa 1 Ya 1 Za 1 (They can be the same or different)

[0094]

[15] According to the organic electroluminescent element of

[12] , the low molecular weight compound represented by the above formula (10) is represented by the following formula (10B).

[0095]

[0096] (In formula (10B),)

[0097] A has the same meaning as A in the above formula (10).

[0098] Xb 1 Yb 1 and Zb 1 Each can independently represent a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or a divalent aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0099] p12, q12, and r12 each independently represent integers from 0 to 6.

[0100] When p12, q12, and r12 are 2 or more, multiple Xb 1 Yb 1 Zb 1 They can be the same or different.

[0101] q13 and r13 each independently represent 0 or 1.

[0102] Among them, q12 and q13 are not both 0, and r12 and r13 are both 0.

[0103] Yb when q13 is 0 2 Zb when r13 is 0 2Each can independently represent a hydrogen atom, an aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or an aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0104] Yb when q13 is 1 2 It is a direct bond.

[0105] Zb when r13 is 1 2 (for direct bonding)

[0106]

[16] According to the organic electroluminescent element of

[15] , the low molecular weight compound represented by the above formula (10) is represented by the following formula (10B-1).

[0107]

[0108] (In formula (10B-1),

[0109] A、Xb 1 Yb 1 Zb 1 Yb 2 Zb 2 q13, r13 and A, Xb in the above formula (10B) 1 Yb 1 Zb 1 Yb 2 Zb 2 q13 and r13 have the same meaning.

[0110] p12', q12', and r12' each independently represent integers from 0 to 5.

[0111] When p12', q12', and r12' are 2 or more, multiple Xb 1 Yb 1 Zb 1 They can be the same or different.

[0112] q15 and r15 are each 4 or 5 independently.

[0113] R 33 It can be a hydrogen atom or a substituent.

[0114] Multiple R in equation (10B-1) 33 (They can be the same or different)

[0115]

[17] The organic electroluminescent element according to

[12] , wherein the low molecular weight compound represented by the above formula (12) is represented by the following formula (12A).

[0116]

[0117] (In formula (12A),

[0118] Ring HA, Ar 0 With the rings HA and Ar in the above formula (31) 0 They have the same meaning.

[0119] The meaning of nc is the same as that of nc in the above formula (12).

[0120] Xc 1 and Yc 1 Each can independently represent a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or a divalent aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0121] Xc 2 and Yc 2 Each can independently represent a hydrogen atom, an aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or an aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0122] s11 and t11 each independently represent integers from 0 to 6.

[0123] When s11 and t11 are 2 or higher, multiple Xc 1 Yc 1 They can be the same or different.

[0124] R 31 It represents a hydrogen atom or a substituent.

[0125] u11 is a substituent R 31 The quantity that can be replaced.

[0126] u12 is a substituent Ar 0 The quantity that can be replaced.

[0127] When u11 is 2 or higher, multiple R 31 (They can be the same or different)

[0128]

[18] An organic EL display device comprising an organic electroluminescent element as described in any one of [1] to

[17] .

[0129]

[19] An organic EL lighting, comprising an organic electroluminescent element as described in any one of [1] to

[17] .

[0130] According to the present invention, an organic electroluminescent element with high brightness and long driving life can be provided.

[0131] The reason why the organic electroluminescent element, as one embodiment of the present invention, achieves the above-mentioned effect is not yet clear, but the following is considered.

[0132] Regarding the organic electroluminescent element of the present invention, both the hole transport layer and the light-emitting layer contain a material having a specific structure as a partial structure (referred to as "partial structure A" in this invention) (hereinafter, sometimes referred to as "material containing partial structure A"). This specific structure is an electron-withdrawing structure comprising an aromatic heterocyclic group with a single ring or 2 to 6 fused rings. In partial structure A, LUMO is easily localized and electron durability is high. Therefore, it is believed that the degradation of the hole transport layer caused by electrons leaking from the light-emitting layer to the hole transport layer is suppressed. Furthermore, it is believed that electrons localized near the interface of the hole transport layer and the light-emitting layer contribute to recombination in the light-emitting layer, thus improving luminous efficiency. Furthermore, it is believed that low voltage is achieved by efficiently transporting electrons and holes. Attached Figure Description

[0133] Figure 1 This is a schematic cross-sectional view showing a structural example of the organic electroluminescent element of the present invention. Detailed Implementation

[0134] Hereinafter, an organic electroluminescent element, an organic EL display device having the organic electroluminescent element, and an embodiment of organic EL lighting, as one embodiment of the present invention, will be described in detail. The following description is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents as long as it does not depart from its spirit.

[0135] [Partial Structure A]

[0136] The organic electroluminescent element of the present invention is characterized in that it is an organic electroluminescent element having an anode, a cathode and an organic layer between the anode and the cathode on a substrate, wherein the organic layer has a hole transport layer and a light-emitting layer adjacent to the hole transport layer, and at least one of the materials contained in the hole transport layer and at least one of the materials contained in the light-emitting layer have the same partial structure A as shown in the following formula (31).

[0137]

[0138] (In formula (31),

[0139] Cyclic HA represents a monocyclic or 2-6 fused rings of aromatic heterocyclic compounds that may have substituents.

[0140] The benzene ring in formula (31) may have substituents.

[0141] Ar 0It represents an aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0142] n1 represents 0 or Ar on ring HA. 0 The number of substitutions that can be performed is an integer.

[0143] When n1 is 2 or more, multiple Ar 0 (They can be the same or different)

[0144] The fact that the material containing partial structure A in the hole transport layer and the material containing partial structure A in the light emission layer have the same partial structure A as shown in formula (31) is an important component for this invention. The effect of this invention can be obtained by having the common partial structure A shown in formula (31) in the material containing the hole transport layer and the material containing the light emission layer.

[0145] In this invention, either or both of the material containing partial structure A in the hole transport layer and the material containing partial structure A in the light-emitting layer are more preferably materials containing partial structure A having two or more of the same partial structure A. Particularly preferred are materials containing partial structure A having two or more identical partial structures A in both the material containing partial structure A in the hole transport layer and the material containing partial structure A in the light-emitting layer. With such a combination, it is expected that the electronic durability of the organic electroluminescent element will be further improved, enabling the organic electroluminescent element to achieve high brightness and long lifetime.

[0146] Here, the term "material containing two or more identical partial structures A" refers to a compound having two or more identical partial structures A within a single compound when the compound is a low-molecular-weight compound. When the compound is a high-molecular-weight compound, it refers to a compound having two or more identical partial structures A within a single repeating unit.

[0147] In this invention, either or both of the materials containing partial structure A in the hole transport layer and the materials containing partial structure A in the light-emitting layer are preferably materials containing two or more materials having partial structure A. With such a combination, it is expected that the electronic durability of the organic electroluminescent element will be further improved, enabling the organic electroluminescent element to achieve high brightness and long lifespan.

[0148] The material containing a portion of structure A in the hole transport layer is not particularly limited, but is preferably a polymer compound. Among the polymer compounds containing a portion of structure A, polymer compounds having repeating units as shown in formula (1) described later are preferred.

[0149] There are no particular restrictions on the material containing part of structure A in the light-emitting layer, but low molecular weight compounds are preferred.

[0150] When the material containing partial structure A is a polymer compound, the number of partial structures A contained in the polymer compound is preferably more than the number of partial structures A contained in the repeating units of the polymer compound. When there are two partial structures A in all repeating units of the polymer compound, the number of partial structures A contained in the polymer compound is polymer repeating units × 2. When the polymer compound has multiple repeating units, it is sufficient that at least one repeating unit has partial structure A.

[0151] There are no particular restrictions on the bonding method of the material containing partial structure A in the hole transport layer and the material containing partial structure A in the light emission layer.

[0152] From the viewpoint of charge transport and electronic durability, in the material containing partial structure A in either the hole transport layer or the light emission layer, partial structure A is preferably as shown in the following formula (31)-2, in which the benzene ring in partial structure A is bonded in the material containing partial structure A.

[0153]

[0154] (In Equation (31)-2, * represents the bonding site in the material containing part of structure A)

[0155] (HA)

[0156] In the partial structure A shown in formula (31) above, HA represents an aromatic heterocycle with a single ring or 2 to 6 fused rings that may have substituents. The ring-forming atom of the aromatic heterocycle, other than carbon, is preferably any one of nitrogen, oxygen, or sulfur.

[0157] The cyclic HA, as described below, is preferably a dibenzofuran ring, a dibenzothiophene ring, a pyridine ring, a pyrimidine ring, or a 1,3,5-triazine ring, with a particular preference for a 1,3,5-triazine ring.

[0158] (Ar 0 )

[0159] In the partial structure A shown in equation (31) above, Ar 0It represents an aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0160] As an aromatic hydrocarbon group, it is preferably a group with 6 or more but less than 60 carbon atoms. Specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. Monovalent groups consisting of a single ring or 2 to 5 fused rings of a six-membered ring such as a cyclopentadiene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, or fluorene ring, or monovalent groups consisting of 2 to 10 rings selected from these.

[0161] Preferably, it is a benzene ring, naphthalene ring, fluorene ring, or a monovalent group consisting of 2 to 10 rings selected from these.

[0162] As an aromatic heterocyclic group, it is preferably a group having 3 or more and 60 or fewer carbon atoms. 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 consisting of single rings or 2 to 4 fused rings 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, cyclophosphine rings, quinoxaline rings, phenanthridine rings, piridine rings, quinazoline rings, quinazoline ketone rings, dibenzofuran rings, dibenzothiophene rings, indole-carbazole rings, and phenanthrene-rhein rings, or monovalent groups consisting of 2 to 10 of these linked monovalent groups.

[0163] Preferably, the monovalent group is a thiophene ring, pyrrole ring, imidazole ring, pyridine ring, pyrimidine ring, triazine ring, quinoline ring, quinazoline ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, indole-carbazole ring, phenanthroline ring, or a monovalent group consisting of 2 to 10 of these linked groups.

[0164] As a monovalent group formed by linking two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents, the group can be formed by linking multiple identical groups or by linking multiple different groups. The total number of linked aromatic hydrocarbon groups and / or aromatic heterocyclic groups is preferably 2 to 10.

[0165] Ar 0 Preferably, it is an aromatic hydrocarbon group that can be substituted with a substituent or an aromatic heterocyclic group that can be substituted with a substituent.

[0166] (Preferred partial structure A)

[0167] From the viewpoint of charge transport and electron durability, the partial structure A shown in equation (31) is preferably the structure shown in equations (33) to (35) below.

[0168]

[0169] (In equations (33) to (35),)

[0170] Ar 0 n1 and Ar in equation (31) 0 The meanings of n1 and n2 are the same. The benzene ring in formulas (33) to (35) can have substituents.

[0171] X and Y each independently represent a C atom or an N atom.

[0172] When X and Y are C atoms, Ar 0 (Can be bonded)

[0173] From the viewpoint of charge transport and electron durability, the above formula (35) is preferably represented by the following formula (36), and more preferably by the following formula (37).

[0174] In the structure shown in formula (37), electron donation and acceptance are carried out using a biphenyl structure with high electron tolerance, and the electron durability of the compound is further improved. As a result, it is believed that the driving lifetime of the organic electroluminescent element is extended.

[0175] In formula (36) below, the three benzene rings may have substituents. In formula (37) below, the four benzene rings may have substituents.

[0176]

[0177] The structure shown in equation (37) above is further preferably the structure represented by equation (37-2) below.

[0178]

[0179] In formula (37-2), "*" and "*1" represent the bonding positions or substituent bonding positions of materials containing partial structure A in the hole transport layer or materials containing partial structure A in the luminescent layer. In formula (37-2), considering that the conjugation of the electronically durable biphenyl structure does not extend, resulting in high S1 and T1 energy levels and less exciton deactivation in the luminescent layer, thus increasing luminous efficiency, at least "*1" is preferably a bonding position or substituent bonding position of materials containing partial structure A in the hole transport layer or materials containing partial structure A in the luminescent layer. From this perspective, it is further preferred that atoms other than hydrogen atoms are bonded to "*1" and at least one "*".

[0180] In formulas (35), (36), and (37) above, X and Y are preferably N atoms. Therefore, from the viewpoint of charge transport and stability, the partial structures shown in formulas (36) and (37) above are preferably the structures shown in formulas (TzP) and (TzP-2) below (hereinafter sometimes referred to as "partial structure (TzP)" and "partial structure (TzP-2)"). It should be noted that the three benzene rings of partial structure (TzP) and the four benzene rings of partial structure (TzP-2) may have substituents.

[0181]

[0182] Formula (TzP-2) is further preferably the structure shown in Formula (TzP-3) below. The reason for preferring the structure shown in Formula (TzP-3) below is the same as the reason for preferring the structure shown in Formula (37-2) above.

[0183]

[0184] In Equation (37-2), “*” and “*1” represent the bonding positions of the materials containing partial structure A in the hole transport layer or the materials containing partial structure A in the luminescent layer, or the bonding positions of the substituents.

[0185] Furthermore, in the organic electroluminescent element of the present invention, among the material containing partial structure A in the hole transport layer and the material containing partial structure A in the light-emitting layer, it is preferable that the similarity of the framework of the common structure of partial structure A is high. High similarity of the framework of the common structure of partial structure A means that the molecular weight of the consistent partial structure A is large.

[0186] When the partial structure A shown in formula (31) is any one of formulas (33) to (35) above, in the material containing partial structure A in the hole transport layer or the material containing partial structure A in the light emission layer, it is preferable that the benzene ring portion of partial structure A is the bonding position in the material containing partial structure A in the hole transport layer or the material containing partial structure A in the light emission layer.

[0187] Ar in equations (31), (33) to (35) above 0 The benzene ring in formulas (31), (33) to (37), (TzP) and (TzP-2) may have substituents selected from the following substituent group Z.

[0188] [Substituted basis set Z]

[0189] The following substituents can be cited as substituent group Z.

[0190] 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 and usually 24 or less, preferably 12 or less.

[0191] For example, vinyl groups are alkenyl groups, which typically have 2 or more carbon atoms and typically have 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms;

[0192] For example, acetylene groups, which typically have 2 or more carbon atoms and typically have 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms;

[0193] For example, alkoxy groups such as methoxy and ethoxy groups typically have 1 or more carbon atoms and typically 24 or fewer, preferably 12 or fewer;

[0194] For example, aryloxy or heteroaryloxy compounds such as phenoxy, naphthoxy, and pyridinoxy typically have 4 or more carbon atoms, preferably 5 or more and typically 36 or less, preferably 24 or less;

[0195] For example, alkoxycarbonyl groups, such as methoxycarbonyl and ethoxycarbonyl, typically have 2 or more carbon atoms and typically 24 or less, preferably 12 or less;

[0196] For example, dialkylamino, dimethylamino, etc., are dialkylamino groups with a carbon number of 2 or more and usually 24 or less, preferably 12 or less;

[0197] For example, diarylamino groups such as diphenylamino, xylylamino, and N-carbazole group typically have 10 or more carbon atoms, preferably 12 or more and typically 36 or less, preferably 24 or less;

[0198] For example, arylalkylamino compounds, such as phenylmethylamino, typically have 7 or more carbon atoms and typically 36 or fewer, preferably 24 or fewer;

[0199] For example, acyl groups such as acetyl and benzoyl have a carbon number of 2 or more and usually 24 or less, preferably 12 or less;

[0200] For example, halogen atoms such as fluorine and chlorine atoms;

[0201] For example, trifluoromethyl and other haloalkyl groups typically have 1 or more carbon atoms and typically 12 or less, preferably 6 or less;

[0202] For example, alkylthio groups such as methylthio and ethylthio typically have 1 or more carbon atoms and typically 24 or less, preferably 12 or less;

[0203] For example, phenylthio, naphthio, pyridinethio, etc. are arylthio or heteroarylthio groups with a carbon number of 4 or more, preferably 5 or more and usually 36 or less, preferably 24 or less;

[0204] For example, silyl groups such as trimethylsilyl and triphenylsilyl typically have 2 or more carbon atoms, preferably 3 or more and typically 36 or less, preferably 24 or less;

[0205] For example, siloxy groups such as trimethylsiloxy and triphenylsiloxy typically have 2 or more carbon atoms, preferably 3 or more and typically 36 or less, preferably 24 or less;

[0206] Cyano;

[0207] For example, the number of carbon atoms in a monovalent group formed by connecting multiple identical or different monocyclic or fused-ring aromatic hydrocarbon rings, such as phenyl or naphthyl, is usually 6 or more and usually 36 or less, preferably 24 or less.

[0208] For example, the number of carbon atoms in a monovalent group formed by connecting multiple identical or different monocyclic or fused-ring aromatic heterocycles, such as thiophene group, is typically 3 or more, preferably 5 or more and typically 36 or less, preferably 24 or less.

[0209] A monovalent aromatic group formed by the connection of an aromatic hydrocarbon ring and an aromatic heterocyclic group, wherein when there are multiple aromatic hydrocarbon rings or aromatic heterocyclic groups, they may be the same or different, and the number of carbon atoms is 8 or more and 36 or less, preferably 24 or less.

[0210] In the above-mentioned substituent group Z, a monovalent aromatic group formed by the connection of the above-mentioned alkyl, alkoxy, aromatic hydrocarbon, aromatic heterocyclic, aromatic hydrocarbon ring, and aromatic heterocyclic group is preferred. From the viewpoint of charge transport, it is further preferred to have no substituent, or to have a monovalent aromatic group formed by the connection of aromatic hydrocarbon, aromatic heterocyclic, aromatic hydrocarbon ring, and aromatic heterocyclic group.

[0211] Each substituent in the above-described substituent group Z may further have substituents. Examples of such substituents include those identical to those in the above-described substituent group Z. Preferably, no further substituents are present, or the substituents are alkyl groups with 6 or fewer carbon atoms, alkoxy groups with 6 or fewer carbon atoms, phenyl groups, or crosslinking groups described later. From the viewpoint of charge transport, it is more preferable that no further substituents are present.

[0212] [Polymer compounds]

[0213] As an example of the present invention, the material containing a portion of structure A in the hole transport layer is a polymer compound, which can be exemplified by a polymer compound containing repeating units as shown in the following formula (1) (hereinafter, sometimes referred to as "polymer of this embodiment").

[0214]

[0215] (In formula (1),)

[0216] A represents a partial structure A.

[0217] G represents an aromatic hydrocarbon group that can have substituents, or an N atom.

[0218] Ar 2 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 via a linking group of two or more groups selected from divalent aromatic hydrocarbon groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents.

[0219] Ar 20 (This refers to a divalent aromatic hydrocarbon group that is directly bonded, may have substituents, or is a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups that may have substituents.)

[0220] (G)

[0221] In the repeating unit shown in formula (1) above, G represents an aromatic hydrocarbon group that may have substituents, or an N atom. From the viewpoint of excellent charge transport properties and the separation and localization of the LUMO distributed around the periphery of partial structure A and the HOMO distributed in the main chain, G is preferably a group composed of a benzene ring that may have substituents, a fluorene ring that may have substituents, or a spirofluorene ring that may have substituents, and more preferably the structure shown in process 1 below. The structure below may also have substituents. In the figure, "-*" indicates a group with Ar 20 The bonding sites.

[0222]

[0223] When G is an aromatic hydrocarbon group that can have substituents, the preferred substituents are any one or a combination of the substituent group Z described above, an aralkyl group with 7 to 40 carbon atoms, or a heterocyclic aralkyl group with 4 to 37 carbon atoms. From a durability perspective, the substituents may be the same or different each time they appear, preferably an alkyl group with 1 to 24 carbon atoms, an aralkyl group with 7 to 40 carbon atoms, a heterocyclic aralkyl group with 3 to 37 carbon atoms, an arylamino group with 10 to 24 carbon atoms, an aromatic hydrocarbon group with 6 to 36 carbon atoms, or an aromatic heterocyclic group with 3 to 36 carbon atoms; more preferably an alkyl group with 1 to 12 carbon atoms, an aralkyl group with 7 to 30 carbon atoms, a heterocyclic aralkyl group with 3 to 27 carbon atoms, an aromatic hydrocarbon group with 6 to 24 carbon atoms, or an aromatic heterocyclic group with 3 to 24 carbon atoms; and even more preferably an aromatic hydrocarbon group with 6 to 24 carbon atoms.

[0224] From the viewpoint of charge transport, the appearance of each group may be the same or different, preferably an aromatic hydrocarbon group with 6 to 24 carbon atoms or an aromatic heterocyclic group with 3 to 24 carbon atoms, and more preferably phenyl, naphthyl, fluorenyl, carbazole, indolocarbazole, indenecarbazole, or indenefluorenyl. In particular, if it is bonded to the 9-position of spirodifluorene or fluorene, the conjugation will be cleaved. Therefore, from the viewpoint of further localizing the LUMO distributed in part of structure A and the HOMO distributed in the main chain, fluorenyl or indenefluorenyl are preferred. From the perspective of ease of synthesis and charge transport stability, G is most preferably without substituents.

[0225] From the perspective of excellent charge transport properties, especially excellent hole transport properties, G is preferably an N atom (nitrogen atom).

[0226] (Ar 2 Ar 20 )

[0227] In the repeating unit shown in equation (1) above, Ar 2It refers to a divalent group formed by connecting two or more groups selected from divalent aromatic hydrocarbon groups that may have substituents, divalent aromatic heterocyclic groups that may have substituents, or divalent groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents.

[0228] Ar 20 It represents a divalent aromatic hydrocarbon group that is directly bonded, may have substituents, or is formed by connecting two or more divalent aromatic hydrocarbon groups that may have substituents.

[0229] As Ar 2 Ar 20 The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group with 6 or more but less than 60 carbon atoms. Specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. A monocyclic ring or a divalent group consisting of 2 to 5 fused rings of a six-membered ring such as a cyclopentadiene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, or a divalent group consisting of 2 to 10 rings selected from these.

[0230] As Ar 2 The aromatic heterocyclic group is preferably an aromatic heterocyclic group having 3 or more and 60 or fewer carbon atoms. 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 A monocyclic or divalent group consisting of 2 to 4 fused rings of five- to six-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 a divalent group consisting of 2 to 10 rings selected from these.

[0231] As Ar 2 The divalent group is formed by connecting two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents. It can be a group formed by connecting multiple identical groups or a group formed by connecting multiple different groups. When multiple groups are connected, it is preferable to connect 2 to 10 groups.

[0232] From the perspectives of excellent charge transport and excellent durability, Ar 2Preferably, the divalent group is a divalent group formed directly or via a linking group, selected from one or more divalent aromatic hydrocarbon groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents. In the case of a linking group, an oxygen atom or a carbonyl group is preferred.

[0233] By forming a non-conjugated structure with aromatic rings, the triplet state level can be improved. Therefore, it is preferable to use oxygen atoms or carbonyl groups to connect the phenylene rings to each other.

[0234] From the viewpoint of improving charge transport and stability through π-conjugation, benzene rings or fluorene rings are preferred.

[0235] From the perspective that the main chain structure, which hinders the expansion of the π-conjugated system, has higher excited singlet and triplet energy levels (S1) and suppresses quenching caused by energy transfer of self-luminescent excitons, resulting in excellent luminescence efficiency, the torsional structure bonded with fluorene rings and alkyl-containing phenylene groups is particularly preferred.

[0236] In terms of ease of synthesis and purification of monomer intermediates, structures containing methyl-containing phenylene groups are particularly preferred.

[0237] Considering the localization of LUMO distributed in part of structure A and HOMO distributed in the main chain, Ar 20 Preferably, it is a group formed by directly bonding or by linking 1 to 9 substituent divalent aromatic hydrocarbon groups, more preferably a group formed by directly bonding or by linking 1 to 7 substituent divalent aromatic hydrocarbon groups. More preferably, it is a group formed by linking 1 to 5 substituent benzene rings, particularly preferably a group formed by linking 3 substituent benzene rings together with the benzene ring contained in A to form a tetraphenylene phenoxide.

[0238] From the viewpoint that the main chain and partial structure A are non-conjugated, and the LUMO distributed in partial structure A and the HOMO distributed in the main chain are further localized, it is preferable to include at least one benzene ring connected at the 1,3 position, and more preferably to include two or more.

[0239] In the case of groups that can be formed by linking multiple divalent aromatic hydrocarbon groups with substituents, from the viewpoint of charge transport or durability, it is preferable to link them all by direct bonding.

[0240] When G is a nitrogen atom, from the perspective of improving hole transport, Ar, which is directly bonded to G, is considered... 2The structure may preferably contain a substituted aromatic hydrocarbon group, more preferably a substituted phenylene group or a substituted fluorene group, and particularly preferably a substituted phenylene group. Preferably, the benzene ring or fluorene ring is bonded to a benzene ring directly bonded to G, which is a nitrogen atom. It is also preferred that one or more phenylene groups are further connected between the benzene ring directly bonded to the nitrogen atom and the fluorene ring.

[0241] In Ar 2 Ar 20 The substituents that can be present in cases other than direct bonding are the same as those that can be present in cases where G is an aromatic hydrocarbon group. From the perspectives of ease of synthesis and charge transport stability, Ar... 2 Ar 20 The optimal choice is one without substituents.

[0242] From the perspective of excellent electronic durability, the -Ar in the repeating unit shown in equation (1) above 20 -A is preferably represented by the following formula (15), and more preferably by the formula (16) described later.

[0243]

[0244] (In formula (15),)

[0245] X and Y each independently represent a C atom or a N atom. A ring with X, Y, and N is equivalent to ring HA in equation (31).

[0246] Ar 1 It refers to a divalent aromatic hydrocarbon group that may have substituents, or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups that may have substituents.

[0247] Ar 3 Ar 4 Each can independently represent an aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0248] Among them, in Ar 1 Ar 3 Ar 4 In at least one of them, the structure bonded to the cyclic HA is a benzene ring.

[0249] * indicates the bonding site with G)

[0250] (Ar 1 )

[0251] Ar 1This refers to a divalent aromatic hydrocarbon group that may have substituents, or a divalent group formed by connecting multiple divalent aromatic hydrocarbon groups that may have substituents. As an aromatic hydrocarbon, it is preferred to have 6 or more and 60 or fewer carbon atoms. Specifically, benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, benzo[a]pyrene rings, etc., are preferred. A monocyclic ring or a divalent group consisting of 2 to 5 fused rings of a six-membered ring such as a cyclopentadiene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, or a divalent group consisting of 2 to 10 rings selected from these.

[0252] As Ar 1 The substituents that may be present can be any of the substituents in the group Z described above, or a combination thereof. From the viewpoint of durability and charge transport properties, it is preferable to use substituents derived from Ar as described above. 2 Substituents that have the same substituents can be selected.

[0253] (Ar 3 Ar 4 )

[0254] Ar 3 and Ar 4 Preferably, each of the groups is an aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups that may have substituents and aromatic heterocyclic groups that may have substituents.

[0255] As an aromatic hydrocarbon group, it is preferably an aromatic hydrocarbon group with 6 or more but less than 60 carbon atoms. Specifically, it is preferably a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetraphenylene ring, pyrene ring, benzo[a]pyrene ring, etc. Monovalent groups consisting of a single ring or 2 to 5 fused rings of a six-membered ring such as a cyclopentadiene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, or fluorene ring, or monovalent groups consisting of 2 to 10 rings selected from these.

[0256] As an aromatic heterocyclic group, it is preferably an aromatic heterocyclic group with 3 or more and 60 or fewer carbon atoms. 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 consisting of single rings or 2 to 4 fused rings 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, borazolin rings, quinoxaline rings, phenanthridine rings, piridine rings, quinazoline rings, and quinazolineone rings, or monovalent groups selected from these rings connected in groups of 2 to 10.

[0257] It is a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups, preferably a monovalent group formed by connecting 2 to 10 structures selected from the above-mentioned aromatic hydrocarbons and aromatic heterocycles.

[0258] From the perspective of LUMO distribution, Ar 3 and Ar 4 Preferably, each has an independent structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-17 and e-1 to e-4 as shown in process 2 below.

[0259] From the viewpoint of promoting LUMO expansion of the molecule by further having electron-withdrawing groups, the structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-13 and e-1 to e-4 is preferred.

[0260] Furthermore, from the viewpoint of a high triplet state level and the effect of confining the formed excitons in the luminescent layer, the structure selected from a-1 to a-4, d-1 to d-13 and e-1 to e-4 is preferred.

[0261] To prevent molecular aggregation, structures selected from d-1 to d-13 and e-1 to e-4 are further preferred.

[0262] From the perspective of ease of synthesis and excellent stability, Ar is particularly preferred. 3 =Ar 4 =The structure of the benzene ring with d-3.

[0263] These structures can also have substituents. In the figure, "-*" indicates the bonding site with ring HA. When there are multiple "-*", any one of them represents the bonding site with ring HA.

[0264]

[0265] R in process 2 above 3A and R 3B Preferably, each alkyl group is 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 in order to maintain the solubility of the polymer, it is preferred to have 1 or more and 6 or less carbon atoms, more preferably 3 or less, and even more preferably methyl or ethyl.

[0266] R 3A and R 3B They can be the same or different. From the perspective of being able to evenly distribute the charge around the nitrogen atom, and thus facilitating synthesis, all R values ​​are preferred. 3A and R 3BThey are the same group.

[0267] As Ar 3 and Ar 4 The substituents that may be present can be any of the substituents in the group Z described above, or a combination thereof. From the viewpoint of durability and charge transport properties, it is preferable to use substituents derived from Ar as described above. 2 Substituents that have the same substituents can be selected.

[0268]

[0269] (In formula (16),)

[0270] X, Y, and * have the same meaning as X, Y, and * in the above formula (15).

[0271] A ring with X, Y and N is equivalent to the ring HA in the same way as equation (15).

[0272] Ar 1’ This indicates direct bonding or Ar in equation (15) above. 1 The residues that are cyclically bonded to cyclic HA and have X, Y, and N rings are benzene rings.

[0273] Ar 3’ Ar 4’ Represents a hydrogen atom or Ar in equation (15) above. 3 Ar 4 (The residues of the cyclic structure with X, Y, and N bonds, equivalent to cyclic HA, are benzene rings)

[0274] [Preferred Repeating Unit Structure]

[0275] The repeating unit shown in the above formula (1) is preferably a repeating unit shown in any of the following formulas (2)-1 to (2)-3.

[0276]

[0277] (In equations (2)-1 to (2)-3,

[0278] A has the same meaning as A in the above formula (1).

[0279] Q represents -C(R) 5 (R) 6 )-、-N(R 7 - or -C(R) 11 (R) 12 )-C(R 13 (R) 14 )-.

[0280] R 1 ~R4 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.

[0281] R 5 ~R 7 and R 11 ~R 14 Each can independently represent 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.

[0282] a and b are each independent integers from 0 to 4.

[0283] c1 to c5 are each an independent integer from 0 to 3.

[0284] Among them, at least one of c3 and c5 is 1 or more.

[0285] d1 to d4 are each an independent integer from 1 to 4.

[0286] There are multiple R in this repeating unit 1 R 2 R 3 R 4 At that time, R 1 R 2 R 3 R 4 (They can be the same or different)

[0287] (R 1 and R 2 )

[0288] R in the repeating units shown in equations (2)-1 to (2)-3 above 1 and R 2 Each can be independently an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents. R 1 and R 2 Preferably, each alkyl group is 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 in order to maintain the solubility of the polymer, it is preferred to have 1 or more and 6 or less carbon atoms, more preferably 3 or less, and even more preferably methyl or ethyl.

[0289] There are multiple R in this repeating unit 1 and R 2 At that time, R 1 and R 2 They can be the same or different. From the perspective of being able to evenly distribute the charge around the nitrogen atom, and thus facilitating synthesis, all R values ​​are preferred. 1 and R2 They are the same group.

[0290] (R 3 and R 4 )

[0291] R in the repeating units shown in equations (2)-1 to (2)-3 above 3 and R 4 Each can be independently an alkyl group that may have substituents, an alkoxy group that may have substituents, or an aralkyl group that may have substituents. R 3 and R 4 Preferably, each alkyl group is 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 in order to maintain the solubility of the polymer, it is preferred to have 1 or more carbon atoms, more preferably 4 or more carbon atoms, more preferably 12 or less carbon atoms, further preferably 8 or less carbon atoms, and particularly preferably hexyl.

[0292] (R 5 ~R 7 and R 11 ~R 14 )

[0293] R 5 ~R 7 and R 11 ~R 14 Each can be 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. R 5 ~R 7 and R 11 ~R 14 Preferably, each can be an alkyl group that may have substituents, an aralkyl group that may have substituents, or an aromatic hydrocarbon group that may have substituents.

[0294] The alkyl group is not particularly limited, but it is preferred to be long to easily improve the solubility of the polymer, and short to improve film stability and charge transport. The alkyl group preferably has 1 or more and 24 or less carbon atoms, more preferably 12 or less, further preferably 8 or less, particularly preferably 6 or less, more preferably 2 or more, further preferably 3 or more, and particularly preferably 4 or more. Furthermore, the alkyl group can be any of the following structures: straight-chain, branched, or cyclic.

[0295] Examples of such alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl, and dodecyl.

[0296] The alkoxy group is not particularly limited, but in order to easily improve the solubility of the polymer, it is preferred that the number of carbon atoms is 1 or more and 24 or less, more preferably 12 or less, even more preferably 8 or less, particularly preferably 6 or less, and preferably 2 or more, even more preferably 3 or more, and particularly preferably 4 or more.

[0297] Specifically, examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, and hexoxy.

[0298] The aralkyl group is not particularly limited, but in order to easily improve the solubility of the polymer, it is preferred that the number of carbon atoms is 7 or more and 60 or less, more preferably 40 or less, more preferably 8 or more, even more preferably 10 or more, and particularly preferably 12 or more.

[0299] Specifically, examples of this aralkyl group include 1,1-dimethyl-1-phenylmethyl, 1,1-di(n-butyl)-1-phenylmethyl, 1,1-di(n-hexyl)-1-phenylmethyl, 1,1-di(n-octyl)-1-phenylmethyl, phenylmethyl, phenylethyl, 3-phenyl-1-propyl, 4-phenyl-1-n-butyl, 1-methyl-1-phenylethyl, 5-phenyl-1-n-propyl, 6-phenyl-1-n-hexyl, 6-naphthyl-1-n-hexyl, 7-phenyl-1-n-heptyl, 8-phenyl-1-n-octyl, 4-phenylcyclohexyl, etc.

[0300] The aromatic hydrocarbon group is not particularly limited, but in order to easily improve the solubility of the polymer, it is preferred to have 6 or more and 60 or less carbon atoms, more preferably 30 or less, further preferably 24 or less, and particularly preferably 14 or less.

[0301] Specifically, examples of aromatic hydrocarbon groups include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. The monovalent group is a single ring or a group consisting of 2 to 5 fused rings, such as a six-membered ring, triphenylene ring, acenaphthene ring, fluoranthene ring, or fluorene ring, or a group consisting of 2 to 8 rings selected from these. Preferably, it is a single ring or a group consisting of 2 to 4 rings.

[0302] From the perspective of improving charge transport and durability, R 5 ~R 7 Preferably alkyl or aromatic hydrocarbon groups, R 5 and R 6 More preferably, it is an alkyl group, R 7 More preferably, it is an aromatic hydrocarbon group, and the preferred number of carbon atoms is as described above.

[0303] From the perspective of improving solubility and excellent charge transport properties, R 5 and R 6Preferably, it is an alkyl group with 3 or more but less than 8 carbon atoms or an aralkyl group with 9 or more but less than 40 carbon atoms.

[0304] The above R 1 ~R 4 Alkyl, alkoxy, aralkyl, R 5 ~R 7 and R 11 ~R 14 The alkyl, alkoxy, aralkyl, and aromatic hydrocarbon groups may further have substituents. Examples of substituents that may be further included as R mentioned above are... 5 ~R 7 and R 11 ~R 14 Preferred groups, such as alkyl, alkoxy, aralkyl, and aromatic hydrocarbon groups, or crosslinking groups described later.

[0305] From the perspective of low voltage, the above R 1 ~R 4 Alkyl, alkoxy, aralkyl, R 5 ~R 7 and R 11 ~R 14 The alkyl, alkoxy, aralkyl, and aromatic hydrocarbon groups are preferably free of substituents.

[0306] In the case where other layers are further coated and laminated after the polymer of this embodiment is formed into a film, from the viewpoint of improving the insolubility in solvents, R 5 ~R 7 and R 11 ~R 14 The substituents that can be further included are preferably crosslinking groups, as described later. Among these, R is preferred from the viewpoint of not easily hindering charge transport. 5 R 6 and R 11 ~R 14 Any of them has the crosslinking group described later as a further substituent, and R is further preferred. 5 and R 6 At least one of them has a crosslinking group as a further substituent, as described later.

[0307] (a, b, c1~c5, d1~d4)

[0308] In the repeating units shown in equations (2)-1 to (2)-2 above, a and b are each independently an integer from 0 to 4. It is preferable that a and b are each less than 2, and it is even more preferable that a and b are both 0 or 1.

[0309] In the repeating units shown in equations (2)-1 to (2)-3 above, c1 to c5 are each independently an integer from 0 to 3. Among them, at least one of c3 and c5 is 1 or higher, and d1 to d4 are each independently an integer from 1 to 4.

[0310] c1~c5 and d1~d4 are preferably each independently 2 or less.

[0311] More preferably, both c1 and c2 are 0 or 1. More preferably, c1 and c2 are 1.

[0312] Preferably, at least one of c3 or c4, or both c3 and c4 are 1 or more. More preferably, both c3 and c4 are 1.

[0313] c5 is preferably 1 or higher.

[0314] C1 and C2, C3 and C4, and D1 to D4 are further preferably equal. Further preferably, C1 to C5 and D1 to D4 are all 1 or 2. Particularly preferably, C1 to C5 and D1 to D4 are all 1.

[0315] In the case where c1 and c2 in the repeating unit shown in equation (2)-1 above are both 1 or 2, and a and b are both 2 or 1, the optimal value is R. 1 With R 2 They are bonded to each other at symmetrical positions.

[0316] In the case where c3 and c4 in the repeating unit shown in equation (2)-2 above are both 1 or 2, and a and b are both 2 or 1, the optimal value is R. 1 With R 2 They are bonded to each other at symmetrical positions.

[0317] Here, about R 1 With R 2 Bonded to positions symmetrical to each other, taking an example of the case where Q=C, c1=c2=1, a=b=2 in the above equation (2)-1, the following equations (1-1) and (1-2) will be used to illustrate the bonded positions symmetrical to each other.

[0318] R 1 With R 2 Bonded at mutually symmetrical positions refers to R relative to the fluorene rings of the main chain in equations (1-1) and (1-2) below. 1 With R 2 The bond positions are opposite. In this case, a 180-degree rotation about the main chain axis is considered the same structure. For example, in equation (1-1) below, R... 1 'With R 2 'In contrast, R 1 "With R" 2 "In contrast, equation (1-1) and equation (1-2) are considered to have the same structure."

[0319]

[0320] (specific example)

[0321] As a specific example of a preferred repeating unit structure, the following structure can be cited.

[0322]

[0323]

[0324]

[0325] [Terminal group]

[0326] In this embodiment, the terminal group refers to the structure at the end of the polymer formed by the end-capping agent used at the end of the polymer polymerization. The terminal group of the polymer in this embodiment is generally a hydrocarbon group. From the viewpoint of charge transport, a hydrocarbon group with 1 or more and 60 or less carbon atoms is preferred, a hydrocarbon group with 1 or more and 40 or less carbon atoms is more preferred, and a hydrocarbon group with 1 or more and 30 or less carbon atoms is even more preferred.

[0327] The following groups are preferred as terminal groups.

[0328] 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 and usually 24 or less, preferably 12 or less.

[0329] For example, vinyl groups are alkenyl groups, which typically have 2 or more carbon atoms and typically have 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms;

[0330] For example, acetylene groups, which typically have 2 or more carbon atoms and typically have 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms;

[0331] For example, aromatic hydrocarbon cyclic groups such as phenyl and naphthyl typically have 6 or more carbon atoms and typically 36 or less, preferably 24 or less.

[0332] These hydrocarbon groups may further have substituents. The substituents that may be further included are preferably alkyl or aromatic hydrocarbon groups. When multiple substituents are present, they can bond together to form a ring.

[0333] The hydrocarbon group that serves as the terminal group may further have substituents, which, from the viewpoint of charge transport and durability, are preferably alkyl or aromatic hydrocarbon groups, and more preferably aromatic hydrocarbon groups.

[0334] [Soluble groups]

[0335] The polymer of this embodiment preferably has a soluble group to exhibit solubility in a solvent. The soluble group in this embodiment is a straight-chain or branched alkyl or alkylene group having 3 or more carbon atoms and 24 or fewer carbon atoms, preferably 12 or fewer carbon atoms. Among these, alkyl, alkoxy, or aralkyl groups are preferred, such as n-propyl, 2-propyl, n-butyl, isobutyl, n-hexyl, n-octyl, etc. n-Hexyl or n-octyl is more preferred. The soluble group may also have substituents.

[0336] (Number of soluble groups)

[0337] Regarding the soluble groups present in the polymer of this embodiment, more are preferred from the viewpoint that it is easy to obtain a polymer solution that can be used in wet film formation. On the other hand, fewer are preferred from the viewpoint that when other layers are formed on the layer formed using the polymer of this embodiment by wet film formation, the reduction in film thickness caused by the dissolution of the lower layer in the solvent is minimal.

[0338] The number of soluble groups in the polymer of this embodiment can be expressed by the number of moles per 1g of polymer.

[0339] When the number of soluble groups in the polymer of this embodiment is expressed in moles per 1g of polymer, the amount per 1g of polymer is typically 4.0 mmol or less, preferably 3.0 mmol or less, more preferably 2.0 mmol or less, and typically 0.1 mmol or more, preferably 0.5 mmol or more.

[0340] If the number of soluble groups is within the above range, the polymer is easily soluble in the solvent, and a composition containing a polymer suitable for wet film formation can be easily obtained. In addition, the density of soluble groups is moderate, and the solubility in organic solvents is sufficient after heating and drying the solvent, so a multilayered structure can be formed using the wet film formation method.

[0341] The number of soluble groups per gram of polymer can be calculated from the molar ratio of monomers and the structural formula during synthesis after removing the terminal groups from the polymer.

[0342] If we consider the case of polymer 1 represented by formula (HT-1) used in Example 1 described later, then as follows, in polymer 1, the average molecular weight of the repeating units excluding the terminal groups is 748.4, and the average number of hexyl groups, which are soluble groups, is 1.3 per repeating unit. If calculated by simple proportion, the number of soluble groups per gram of molecular weight is calculated to be 1.74 mmol.

[0343]

[0344] [Crosslinking groups]

[0345] The polymer of this embodiment may also have crosslinking groups. The crosslinking groups in the polymer of this embodiment may be present in the repeating unit shown in formula (1) above, or they may be present in repeating units different from the repeating unit shown in formula (1) above. In particular, it is preferable that the aromatic hydrocarbon group or aromatic heterocyclic group that serves as the side chain bond has crosslinking groups, as it facilitates the crosslinking reaction.

[0346] By having cross-linking groups, it is possible to produce a large difference in solubility in organic solvents before and after a reaction (a poorly soluble reaction) that occurs under the influence of heat and / or active energy rays.

[0347] A crosslinking group is a group that reacts with groups that make up other molecules located near the crosslinking group to form new chemical bonds through irradiation with heat and / or active energy rays. In this case, the reacting group can be the same as the crosslinking group or a different group.

[0348] As a crosslinking group, it is preferably a group comprising a cyclobutene ring fused to an aromatic ring and an alkenyl group bonded to an aromatic ring, and more preferably a group selected from the following crosslinking group group K. The crosslinking group is preferably contained in the polymer in the form of substituents further replaced by those present in the above-described structures.

[0349] (Crosslinking group group K)

[0350] The crosslinking group group K has the structure shown below.

[0351]

[0352] In the above crosslinking group group K, R 21 ~R 23 Each can independently represent a hydrogen atom or an alkyl group. R 24 ~R 26 Each can independently represent an alkyl or alkoxy group. p represents an integer from 1 to 4, q represents an integer from 1 to 4, and r represents an integer from 1 to 4.

[0353] When p is 2 or higher, multiple R 24 They can be the same or different, adjacent R 24 They can also bond together to form a ring.

[0354] When q is 2 or more, multiple R 25 They can be the same or different, adjacent R 25 They can also bond together to form a ring.

[0355] When r is 2 or higher, multiple R 26They can be the same or different, adjacent R 26 They can also bond together to form a ring.

[0356] Ar 21 Ar 22 Each can be independently represented as an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents.

[0357] "-*" indicates the bonding site.

[0358] As R 21 ~R 26 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 are more preferred. It is believed that through R... 21 ~R 26 The alkyl group has 6 or fewer carbon atoms, which does not stereochemically hinder the crosslinking reaction, and the film formed by the polymer of this embodiment is prone to insolubility.

[0359] As R 24 ~R 26 The alkoxy group can be categorized into straight-chain or branched chain alkoxy groups with 6 or fewer carbon atoms. Examples include methoxy, ethoxy, n-propoxy, 2-propoxy, and n-butoxy. Methoxy or ethoxy are more preferred. It is assumed that if R... 24 ~R 26 If the number of carbon atoms is 6 or less, the cross-linking reaction will not be hindered by stereochemistry, and the film formed by the polymer of this embodiment is prone to insolubility.

[0360] As Ar 21 and Ar 22 The aromatic hydrocarbon group may have substituents, such as a single ring with a six-membered ring, such as a benzene ring or a naphthalene ring, or a fused ring with 2 to 5 rings. In particular, a benzene ring with a single free valence is preferred.

[0361] Ar 22 It can also be a group formed by bonding two or more aromatic hydrocarbon groups that can have substituents. Examples of such groups include biphenylene and terphenylene, with 4,4'-biphenylene being the most preferred.

[0362] As Ar 21 and Ar 22 The group can be an aromatic heterocyclic group with substituents, such as a monocyclic ring or a triazine ring with one free valence, or a fused ring of two to five members. A triazine ring with one free valence is particularly preferred.

[0363] Ar 21 Ar 22It can have the same substituents as the substituent group Z mentioned above.

[0364] As crosslinking groups, from the perspective of further improving the electrochemical stability of the device, groups that can undergo cyclization addition reactions, such as aryl vinyl carbonyl groups like cinnamyl, benzocyclobutene rings with a monovalent free valence, and 1,2-dihydrocyclobutene[a]naphthyl rings with a monovalent free valence, are preferred.

[0365] Among the crosslinking groups, from the perspective of particularly stable crosslinked structure, groups comprising cyclobutene rings fused to an aromatic ring having a monovalent free valence or 1,2-dihydrocyclobutene[a]naphthyl rings having a monovalent free valence are preferred, with benzocyclobutene rings or 1,2-dihydrocyclobutene[a]naphthyl rings having a monovalent free valence being more preferred. From the perspective of low crosslinking reaction temperature, 1,2-dihydrocyclobutene[a]naphthyl rings having a monovalent free valence are particularly preferred as crosslinking groups.

[0366] (Number of cross-linking groups)

[0367] Regarding the crosslinking groups of the polymer in this embodiment, more is preferred from the perspective that they are sufficiently insoluble through crosslinking, making it easy to form other layers on them using a wet film-forming method. On the other hand, fewer crosslinking groups are preferred from the perspective that the formed layers are less prone to cracking, less likely to leave unreacted crosslinking groups, and easier to extend the lifespan of the organic electroluminescent element.

[0368] In this embodiment, the number of crosslinking groups present in one polymer chain is preferably 1 or more, more preferably 2 or more, and preferably 200 or less, more preferably 100 or less.

[0369] The number of crosslinking groups in the polymer of this embodiment can be expressed as the number relative to the molecular weight of the polymer, which is 1000.

[0370] When the number of crosslinking groups in the polymer of this embodiment is expressed as the number relative to the molecular weight of the polymer 1000, it is generally 3.0 or less, preferably 2.0 or less, more preferably 1.0 or less, and generally 0.01 or more, preferably 0.05 or more, relative to the molecular weight of 1000.

[0371] If the number of crosslinking groups is within the above range, cracks are less likely to occur, and a flat film can be easily obtained from the polymer of this embodiment. In addition, since the crosslinking density is moderate, there are few unreacted crosslinking groups remaining in the layer after the crosslinking reaction, which is less likely to affect the lifespan of the obtained device.

[0372] Furthermore, due to the sufficient solubility of organic solvents after the cross-linking reaction, it is easy to form a multilayered structure using the wet film-forming method.

[0373] The number of crosslinking groups per 1000 molecular weight of the polymer can be calculated from the molar ratio of the monomers incorporated during synthesis and the structural formula after removing the terminal groups from the polymer.

[0374] If we consider the case of polymer 1 represented by formula (HT-1) used in Example 1 described later, in polymer 1, the average molecular weight of the repeating units excluding the terminal groups is 748.4, and there are 0.15 crosslinking groups per repeating unit. If calculated by simple proportion, the number of crosslinking groups relative to a molecular weight of 1000 is calculated to be 0.20.

[0375]

[0376] [The amount of repeating units]

[0377] In the polymer of this embodiment, the content of the repeating unit shown in formula (1) is not particularly limited, and it is generally contained in the polymer at 5 mol% or more, preferably at 10 mol% or more, more preferably at 15 mol% or more, and particularly preferably at 20 mol% or more. In the polymer of this embodiment, the repeating unit may consist only of the repeating unit shown in formula (1), but for the purpose of balancing various performance characteristics when manufacturing an organic electroluminescent element, it may also have repeating units different from those in formula (1). In this case, the content of the repeating unit shown in formula (1) in the polymer is generally 99 mol% or less, preferably 95 mol% or less.

[0378] [Other preferred repeating units that may be included]

[0379] The polymer of this embodiment also preferably further comprises the repeating unit shown in formula (3) below. The repeating unit shown in formula (3) is preferably the repeating unit shown in any one of formula (3)-1, formula (3)-2 or formula (3)-3 below.

[0380]

[0381] (In formula (3),)

[0382] Ar 13 This indicates an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents but does not contain part of structure A.

[0383] Ar 14This 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 via a linking group of two or more groups selected from divalent aromatic hydrocarbon groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents.

[0384]

[0385] (In equations (3)-1 to (3)-3,

[0386] Ar 7 This indicates an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents but does not contain part of structure A.

[0387] Q represents -C(R) 5 (R) 6 )-、-N(R 7 - or -C(R) 11 (R) 12 )-C(R 13 (R) 14 )-.

[0388] R 1 ~R 4 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.

[0389] R 5 ~R 7 and R 11 ~R 14 Each can independently represent 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.

[0390] a and b are each independent integers from 0 to 4.

[0391] c1 to c5 are each an independent integer from 0 to 3.

[0392] Among them, at least one of c3 and c5 is 1 or more.

[0393] d1 to d4 are each an independent integer from 1 to 4.

[0394] There are multiple R in this repeating unit 1 R 2 R 3 R 4 At that time, R 1 R 2 R 3 R 4 They can be the same or different.

[0395] Among them, Q and R 1 ~R 4 Q and R can be used in equations (2)-1 to (2)-3 above. 1 ~R 4 The structure is the same, and the preferred range is also the same. Therefore, the same symbols can be used, but they can also be different.

[0396] c1~c5 and d1~d4 can take the same values ​​as c1~c5 and d1~d4 in equations (2)-1 to (2)-3 above, and the preferred ranges are also the same. Therefore, the same symbols can be used, but they can also be different.

[0397] (Ar 7 )

[0398] In the repeating units shown in equations (3)-1 to (3)-3 above, Ar 7 Each repeating unit independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents but does not contain part of structure A.

[0399] The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group with 6 or more but less than 60 carbon atoms. Specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. A monovalent group consisting of a single ring or 2 to 5 fused rings of a six-membered ring, such as a triphenylene ring, acenaphthene ring, fluoranthene ring, or fluorene ring, or multiple rings selected from these. When multiple rings are connected, a monovalent group consisting of 2 to 10 rings is preferred.

[0400] The aromatic heterocyclic group is preferably an aromatic heterocyclic group having 3 or more and 60 or fewer carbon atoms. 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 A monovalent group consisting of a single ring or 2 to 4 fused rings of five- to six-membered rings, such as azole rings, benzisothiazolium rings, benzimazole rings, pyrazine rings, pyridazine rings, quinoline rings, isoquinoline rings, cyclophosphine rings, quinoxaline rings, phenanthridine rings, piridine rings, quinazoline rings, and quinazolineone rings, or multiple rings selected from these. When multiple rings are connected, it is preferable to connect 2 to 10 monovalent groups.

[0401] From the perspectives of excellent charge transport and excellent durability, Ar 7Preferably, it is an aromatic hydrocarbon group that can have substituents. More preferably, it is a monovalent group of a benzene ring or fluorene ring that can have substituents, i.e., a phenyl or fluorenyl group that can have substituents, even more preferably a fluorenyl group that can have substituents, and particularly preferably a 2-fluorenyl group that can have substituents.

[0402] As Ar 7 The aromatic hydrocarbon group may have substituents, and there are no particular limitations as long as they do not significantly reduce the properties of the polymer of this embodiment. Preferably, substituents are selected from the substituent group Z or the crosslinking groups described above. As such substituents, alkyl, alkoxy, aromatic hydrocarbon, aromatic heterocyclic group that is not equivalent to part of structure A, or the crosslinking groups described above are preferred, and alkyl is more preferred.

[0403] From the perspective of solubility in coating solvents, Ar 7 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, a 9-alkyl-2-fluorenyl group with an alkyl group substituted at the 9-position of the 2-fluorenyl group is preferred, and particularly preferred is a 9,9'-dialkyl-2-fluorenyl group with two substituted alkyl groups. By having a fluorenyl group substituted with an alkyl group at at least one of the 9- and 9' positions, the solubility in solvents and the durability of the fluorenyl ring are easily improved. Furthermore, by having a fluorenyl group substituted with an alkyl group at both the 9- and 9' positions, the solubility in solvents and the durability of the fluorenyl ring are easily further improved.

[0404] Ar 7 The inclusion of the aforementioned crosslinking groups enhances the insolubility of the solvent during film formation and subsequent lamination.

[0405] From the viewpoint of insolubility, it is preferable to include repeating units of formulas (3)-1 to (3)-3 containing at least one of the aforementioned crosslinking groups as further substituents. This crosslinking group is preferably further substituted with Ar. 7 The aromatic hydrocarbon groups shown may have substituents.

[0406] (specific example)

[0407] As specific examples of the repeating unit structures shown in equations (3)-1 to (3)-3 above, the following structures can be cited.

[0408]

[0409]

[0410]

[0411] [Other repeating units]

[0412] From the perspective of charge transport and durability, the polymer of this embodiment may further include repeating units as shown in formula (4) or formula (5) below.

[0413]

[0414] -Ar 10 - (5)

[0415] In equation (4), R 8 and R 9 Each can independently represent a hydrogen atom, an alkyl group that may have substituents, an aromatic hydrocarbon group that may have substituents, or an aromatic heterocyclic group that may have substituents.

[0416] In equation (5), Ar 10 It refers to a divalent aromatic hydrocarbon group that may have substituents, an aromatic heterocyclic group that may have substituents, or a divalent group formed by directly or via a linking group of two or more groups selected from divalent aromatic hydrocarbon groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents.

[0417] (R 8 and R 9 )

[0418] As R 8 and R 9 The alkyl, aromatic hydrocarbon, and aromatic heterocyclic groups can be exemplified as substituent group Z above. These groups may have substituents that are preferably the same as those in substituent group Z or the crosslinking groups described above.

[0419] (Ar 10 )

[0420] As Ar 10 The specific structure can be exemplified by Ar, which is similar to the above equation (1). 2 The same divalent groups. These groups may have substituents that are preferably the same as those in the substituent group Z or the crosslinking groups described above.

[0421] [Molecular weight of the polymer]

[0422] The weight-average molecular weight (Mw) of the polymer in this embodiment is typically 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 200,000 or less, particularly preferably 100,000 or less, typically 10,000 or more, and preferably 15,000 or more.

[0423] When the weight-average molecular weight of the polymer is below the upper limit mentioned above, there is a tendency to obtain excellent solvent solubility and film-forming properties. When the weight-average molecular weight of the polymer is above the lower limit mentioned above, the decrease in the glass transition temperature, melting point, and vaporization temperature of the polymer is suppressed, and the heat resistance is improved. In addition, there are cases where the coating film is sufficiently insoluble in organic solvents after the crosslinking reaction.

[0424] The number average molecular weight (Mn) of the polymer in this embodiment is generally 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, particularly preferably 100,000 or less, generally 2,000 or more, preferably 4,000 or more, more preferably 8,000 or more, and even more preferably 20,000 or more.

[0425] The dispersion (Mw / Mn) of the polymer in this embodiment is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. A smaller dispersion value is better, therefore a lower limit of 1 is ideal. If the dispersion of the polymer is below the aforementioned upper limit, it is easy to purify and exhibits good solubility in solvents or good charge transport properties.

[0426] Typically, the weight-average molecular weight and number-average molecular weight of polymers are determined by size exclusion chromatography (SEC). In SEC determination, higher molecular weight components require shorter elution times, while lower molecular weight components require longer elution times. The elution time of the sample is converted into molecular weight using a calibration curve calculated based on the elution time of polystyrene (a standard sample) with a known molecular weight, and the weight-average molecular weight and number-average molecular weight are then calculated.

[0427] [Preferred Polymers]

[0428] The polymer in this embodiment is most preferably represented by any one of the following formulas (6a) to (6h).

[0429]

[0430] In the polymers of formulas (6a) to (6h), A, Q, and R 1 R 2 R 3 R 4 A, Q, and R in equations (2)-1 to (2)-3 above 1 R 2 R 3 R 4 Same. Ar 7 Ar in equations (3)-1 to (3)-3 above 7 Same. At least one A or Ar in each polymer. 7 Preferably, it has the above-mentioned crosslinking groups. n and m represent the number of repetitions.

[0431] [Specific example]

[0432] The following examples illustrate specific examples of polymers of this embodiment other than polymer 1 represented by formula (HT-1) and polymers represented by formulas (HT-2) and (HT-4) used in the embodiments described later. The polymers of this embodiment are not limited to these. The numbers in the following chemical formulas indicate the molar ratio of repeating units.

[0433] These polymers can be any of random copolymers, alternating copolymers, block copolymers, or graft copolymers, and the order of repeating units is not limited.

[0434]

[0435]

[0436]

[0437]

[0438]

[0439] [Polymer Manufacturing Methods]

[0440] There are no particular limitations on the method for manufacturing the polymer in this embodiment. For example, it can be manufactured by polymerization methods utilizing the Suzuki reaction, the Grignard reaction, the Yamamoto reaction, the Ullmann reaction, or the Buchwald-Hartwig reaction.

[0441] In the case of polymerization using the Ullmann reaction and polymerization using the Buchwald-Hartwig reaction, the polymer of this embodiment is synthesized, for example, by reacting the dihaloaryl group (E represents halogen atoms such as I, Br, Cl, F, etc.) shown in formula (1a) with the primary aminoaryl group shown in formula (1b) and further reacting with the dihaloaryl group shown in formula (2a).

[0442]

[0443] In the above formula, A and R 1 ~R 2 Q, a, b, c1, d1 have the same meaning as equations (2)-1 to (2)-3 above. n and m represent the number of repetitions.

[0444] In the above polymerization methods, the reaction that forms the N-aryl bond is typically carried out in the presence of a base such as potassium carbonate, sodium tert-butoxide, or triethylamine. Alternatively, it can be carried out in the presence of a transition metal catalyst such as a copper or palladium complex.

[0445] [Low molecular weight compounds]

[0446] The material containing a portion of structure A in the light-emitting layer, as an embodiment of the present invention, is preferably a low molecular weight compound. The material containing a portion of structure A in the low molecular weight compound is preferably a compound with a molecular weight of 5000 or less as shown in the following formula (10), formula (11) or formula (12) (hereinafter, these compounds are sometimes referred to as "low molecular weight compounds of this embodiment").

[0447]

[0448] (In equations (10) to (12),)

[0449] A represents the aforementioned partial structure A.

[0450] B represents a single bond or any partial structure.

[0451] na, nb, and nc represent integers from 1 to 5.

[0452] When na, nb, and nc are 2 or more, multiple A, B, and AB can be the same or different.

[0453] (B)

[0454] B in formulas (10) and (11) above is not particularly limited. Preferably, it can be a functional group that can have a substituent, an aromatic hydrocarbon group that can have a substituent, an aromatic heterocyclic group that can have a substituent, or a group formed by directly or via a linking group of two or more groups selected from aromatic hydrocarbon groups that can have a substituent and aromatic heterocyclic groups that can have a substituent.

[0455] As a functional group, it is preferred to include a group containing a structure with hole transport capability, a structure with electron transport capability, a structure that inhibits charge transport, a structure that imparts solubility in organic solvents, a structure that hinders crystallization and improves amorphousness, or a group with luminescent properties.

[0456] Preferably, the structure comprises an aromatic amine structure, i.e., at least one aromatic hydrocarbon group bonded to the nitrogen atom of the amine, as a group that has hole transport capability.

[0457] As a group consisting of two or more groups selected from aromatic hydrocarbon groups, aromatic heterocyclic groups, aromatic hydrocarbon groups that may have substituents, and aromatic heterocyclic groups that may have substituents, either directly or via a linking group, preferably based on Ar in the above formula (31). 0 Groups with the same structure.

[0458] As a location of A where B is bonded, preferably at least one B is bonded to a ring HA in part of structure A.

[0459] The low molecular weight compound in this embodiment is preferably a charge transport material in the light-emitting layer. The low molecular weight compound in this embodiment is preferably a compound represented by formula (10) or formula (12) above.

[0460] The compound represented by formula (10) above is preferably a compound represented by formula (10A) or formula (10B) below. The compound represented by formula (12) above is preferably a compound represented by formula (12A) below.

[0461]

[0462] (In formula (10A),

[0463] HA represents any of the trivalent aromatic heterocyclic groups shown in the following structural formulas (10A-a), (10A-b), and (10A-c).

[0464] Xa 1 Ya 1 and Za 1 Each can independently represent a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or a divalent aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0465] Xa 2 Ya 2 and Za 2 Each can independently represent a hydrogen atom, an aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or an aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0466] g11, h11, and j11 each independently represent integers from 0 to 6.

[0467] At least one of g11, h11, and j11 is an integer greater than or equal to 1.

[0468] When g11, h11, and j11 are 2 or higher, Xa 1 Ya 1 Za 1 They can be the same or different.

[0469] R 31 Represents a hydrogen atom or substituent. 4 R's 31 (They can be the same or different)

[0470]

[0471] (In equations (10A-a) to (10A-c), * indicates the bonding position)

[0472]

[0473] (In formula (10B),)

[0474] A has the same meaning as A in the above formula (10).

[0475] Xb 1 Yb 1 and Zb 1 Each can independently represent a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or a divalent aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0476] p12, q12, and r12 each independently represent integers from 0 to 6.

[0477] When p12, q12, and r12 are 2 or higher, multiple Xb 1 Yb 1 Zb 1 They can be the same or different.

[0478] q13 and r13 each independently represent 0 or 1.

[0479] Among them, q12 and q13 are not both 0, and r12 and r13 are both 0.

[0480] Yb when q13 is 0 2 Zb when r13 is 0 2 Each can independently represent a hydrogen atom, an aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or an aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0481] Yb when q13 is 1 2 It is a direct bond.

[0482] Zb when r13 is 1 2 (for direct bonding)

[0483]

[0484] (In formula (12A),

[0485] Ring HA, Ar 0With the rings HA and Ar in the above formula (31) 0 They have the same meaning.

[0486] The meaning of nc is the same as that of nc in the above formula (12).

[0487] Xc 1 and Yc 1 Each can independently represent a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or a divalent aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0488] Xc 2 and Yc 2 Each can independently represent a hydrogen atom, an aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or an aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents.

[0489] s11 and t11 each independently represent integers from 0 to 6.

[0490] When s11 and t11 are 2 or higher, multiple Xc 1 Yc 1 They can be the same or different.

[0491] R 31 It represents a hydrogen atom or a substituent.

[0492] u11 is a substituent R 31 The quantity that can be replaced.

[0493] u12 is a substituent Ar 0 The quantity that can be replaced.

[0494] When u11 is 2 or higher, multiple R 31 (They can be the same or different)

[0495] In formulas (10A), (10B), and (12A) above, the aromatic hydrocarbon ring, which is an aromatic hydrocarbon group with 6 to 30 carbon atoms, is preferably a single six-membered ring or a fused ring of 2 to 5 members. Specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, fluorene rings, perylene rings, tetraphenylene rings, pyrene rings, and benzo[a]pyrene rings. Cyclic rings, triphenylene rings, fluoranthene rings, etc. More preferably, they are monocyclic or 2-3 fused rings; specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, and fluorene rings. Among these, benzene rings, naphthalene rings, phenanthrene rings, and fluorene rings are preferred, and benzene rings or fluorene rings are more preferred.

[0496] In formulas (10A), (10B), and (12A) above, the aromatic heterocyclic group having 3 to 30 carbon atoms is preferably a single ring of five or six members or 2 to 5 fused rings thereof. Specifically, examples include furan rings, benzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, pyrrole rings, pyrazole rings, and imidazole rings. Diazole ring, indole ring, carbazole ring, indole-carbazole ring, pyrrolo-imidazol ring, pyrrolo-pyrazole ring, pyrrolo-pyrazole ring, thiophenolo-pyrazole ring, thiophenolo-thiophene ring, furano-pyrazole ring, furano-furan ring, thiophenolo-furan ring, benzyl isocyanate Azole ring, benzisothiazolium ring, benzimazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cyclophosphine ring, quinoxaline ring, peptidine ring, quinazoline ring, quinazoline ring, etc.

[0497] Preferably, the ring is a thiophene ring, a pyrrole ring, an imidazole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, an indole-carbazole ring, or a phenanthroline ring; more preferably, it is a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, or an indole-carbazole ring; and even more preferably, it is a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, or an indole-carbazole ring.

[0498] In the above formula (10A), Xa 2 Ya 2 Za 2 When q13 = 0 in the above formula (10B), Yb 2 Zb when r13 = 0 2 Xc in the above formula (12A) 2 Yc 2 The aromatic hydrocarbon rings in the mixture are preferably benzene rings, naphthalene rings or phenanthrene rings, and the aromatic heterocycles are preferably carbazole rings, dibenzofuran rings, dibenzothiophene rings or indolocarbazole rings, and more preferably aromatic hydrocarbon rings.

[0499] R as a substituent 31 Preferably, the substituent is an aromatic hydrocarbon group with 6 to 30 carbon atoms or an aromatic heterocyclic group with 3 to 30 carbon atoms. From the viewpoint of improving durability and charge transport, an aromatic hydrocarbon group with substituent is further preferred. The R in the case of substituent... 31 When multiple instances exist, they can be different from each other.

[0500] Substituents that can be present in the aromatic rings of hydrocarbons with 6 to 30 carbon atoms, and substituents that can be present in heteroaromatic rings with 3 to 30 carbon atoms, i.e., substituents R 31The substituents that may be present are the same as those listed in substituent group Z or the crosslinking groups in the polymer of this embodiment, and the preferred substituents are also the same. These substituents may further include the same substituents.

[0501] The compound shown in the above formula (10A) is more preferably the compound shown in the following general formulas (10A-1) to (10A-3).

[0502]

[0503] (In formulas (10A-1) to (10A-3),

[0504] Xa 1 Ya 1 Za 1 Xa 2 Ya 2 Za 2 With Xa in equation (10) 1 Ya 1 Za 1 Xa 2 Ya 2 Za 2 They have the same meaning.

[0505] R 33 Represents a hydrogen atom or a substituent. Multiple Rs 33 They can be the same or different.

[0506] g11', h11', and j11' each independently represent integers from 0 to 5.

[0507] When g11', h11', and j11' are 2 or more, multiple Xa 1 Ya 1 Za 1 (They can be the same or different)

[0508] In the above formulas (10A-1) to (10A-3), the partial structure formed by bonding one of the three benzene rings with the central pyridine ring, pyrimidine ring, or triazine ring can be regarded as partial structure A, and R is bonded to the benzene ring constituting partial structure A. 33 Equivalent to R in equation (10A) 31 .

[0509] The compound represented by the above formula (10B) is preferably the compound represented by the following formula (10B-1).

[0510]

[0511] (In formula (10B-1),

[0512] A、Xb 1 Yb 1 Zb 1 Yb 2 Zb 2 q13, r13 and A, Xb in the above formula (10B) 1 Yb 1 Zb 1 Yb 2 Zb 2 q13 and r13 have the same meaning.

[0513] p12', q12', and r12' each independently represent integers from 0 to 5.

[0514] When p12', q12', and r12' are 2 or more, multiple Xb 1 Yb 1 Zb 1 They can be the same or different.

[0515] q15 and r15 are each 4 or 5 independently.

[0516] R 33 It can be a hydrogen atom or a substituent.

[0517] Multiple R in equation (10B-1) 33 (They can be the same or different)

[0518] R in equations (10A-1) to (10A-3) and (10B-1) above 33 When it is a substituent, the group and R 33 When it is a substituent, it can further have substituents and the above-mentioned R. 31 The same applies to the case.

[0519] [Molecular weight]

[0520] The molecular weight of the low-molecular-weight compound in this embodiment is typically 5000 or less, 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. Since the molecular weight of the low-molecular-weight compound in this embodiment includes the desired partial structure A, its molecular weight is typically above the aforementioned lower limit.

[0521] [Specific example]

[0522] The following are specific examples of low molecular weight compounds used in this embodiment. The low molecular weight compounds used in this embodiment are not limited to these examples.

[0523]

[0524]

[0525]

[0526] [Luminescent dopant]

[0527] In one aspect of the present invention, the low-molecular-weight compound contained in the light-emitting layer, i.e., the material containing a portion of structure A, is preferably a light-emitting dopant. As a light-emitting dopant, the compound shown in the following formula (40) is preferred. In the following formula (40), the ring HA in the portion of structure A shown in the above formula (31) corresponds to a triazine ring, and Ar... 0 Corresponding to the pyridine ring. In equation (40), R... 44 In the case where n1 is 2, and the other Ar is a substituted aromatic hydrocarbon group, a substituted aromatic heterocyclic group, or a monovalent group formed by connecting two or more groups selected from substituted aromatic hydrocarbon groups and substituted aromatic heterocyclic groups, the other Ar is 2. 0 For R 44 .

[0528]

[0529] In equation (40) above, R 41 R 42 R 43 Each group is independently an alkyl group having 1 to 20 carbon atoms, a (hetero)arylalkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 30 carbon atoms. These groups may further have substituents. In the presence of multiple R groups... 41 R 42 R 43 In the case of multiple R, they can be the same or different. 41 In the case of adjacent R 41 They can bond together to form a ring.

[0530] a40 is an integer from 0 to 4, b40 is an integer from 0 to 3, and c40 is an integer from 0 to 5.

[0531] R 44Each group is independently composed of a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an alkyl group with 1 to 20 carbon atoms, a (hetero)arylalkyl group with 7 to 40 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, a (hetero)aryloxy group with 3 to 20 carbon atoms, an alkylsilyl group with 1 to 20 carbon atoms, an arylsilyl group with 6 to 20 carbon atoms, an alkylcarbonyl group with 2 to 20 carbon atoms, an arylcarbonyl group with 7 to 20 carbon atoms, an alkylamino group with 2 to 20 carbon atoms, an arylamino group with 6 to 20 carbon atoms, or a (hetero)aryl group with 3 to 20 carbon atoms. These groups may further have substituents. The presence of multiple R groups... 44 In this case, they can be the same or different.

[0532] L 1 This indicates an organic ligand, where m40 is an integer from 1 to 3.

[0533] From a durability perspective, R 41 ~R 44 More preferably, each of the following is independently an alkyl group having 1 to 20 carbon atoms, a heteroaryl group having 7 to 40 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a heteroaryl group having 3 to 30 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms; even more preferably, an alkyl group having 1 to 20 carbon atoms, a heteroaryl group having 7 to 40 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms; and even more preferably, an alkyl group having 1 to 20 carbon atoms, an aryl group having 7 to 40 carbon atoms or an aryl group having 6 to 20 carbon atoms.

[0534] R 41 ~R 44 The substituents that may be further included are preferably substituents selected from the substituent group Z described above.

[0535] When a40 is 2 or higher, two adjacent R 41 They can bond together to form a ring.

[0536] As there are multiple R 41 And adjacent R 41 Substances that bond together to form rings include, for example, fluorene, naphthalene, dibenzothiophene, and dibenzofuran. From a stability point of view, fluorene is particularly preferred.

[0537] From the viewpoint of extending the emission wavelength, adjacent R values ​​are preferred. 41 Substances that bond together to form rings.

[0538] Furthermore, from the viewpoint of avoiding increasing the wavelength of the emitted light, adjacent R values ​​are preferred. 41 Substances that are not mutually bonded and do not form rings. That is, in preferred formula (40), a40 is 1, or a40 is 2 or more and does not have adjacent R. 41A ring formed by mutual bonding.

[0539] From the perspective of ease of manufacture, a40 is preferably 0; from the perspective of improving durability and solubility, it is preferably 1 or 2, and more preferably 1. From the perspective of ease of manufacture, b40 is preferably 0; from the perspective of improving solubility, it is preferably 1.

[0540] From the perspective of having many structures with high electron acceptability containing triazine rings and more stable LUMO, m40 is preferably 2 or 3, and more preferably 3.

[0541] L 1 The ligand is an organic ligand, with no particular limitation, but preferably a monovalent bidentate ligand, more preferably selected from the following chemical formulas. It should be noted that the dashed lines in the following chemical formulas represent coordinate bonds. In the presence of two organic ligands L... 1 In the case of organic ligand L 1 They can be of different structures. Additionally, when m40 is 3, L does not exist. 1 .

[0542] When m40 in equation (40) is less than 3, L 1 Preferably, it has at least one structure selected from the following formulas (3), (4) and (5).

[0543]

[0544] In equations (3), (4), and (5) above, R 49 R 50 R in equation (40) above 41 The meaning is the same. That is, selected from and as R 41 And within the same group of substituents, preferred examples are also possible, which may further contain substituents. In the presence of multiple R... 49 R 50 In this case, they can be the same or different.

[0545] R 51 ~R 53 Each of the following can be a hydrogen atom, an alkyl group with 1 to 20 carbon atoms that can be replaced by a fluorine atom, a phenyl group that can be replaced by an alkyl group with 1 to 20 carbon atoms, or a halogen atom.

[0546] g is an integer from 0 to 4. h is an integer from 0 to 4.

[0547] Ring B 40 It can be a pyridine ring, pyrimidine ring, imidazole ring, quinoline ring, isoquinoline ring, quinazoline ring, quinoxaline ring, azatriphenylene ring, carbline ring, benzothiazole ring, or benzo[] Azole ring. Ring B 40It can further have substituents.

[0548] R 49 R 50 Ring B 40 The substituents that may be further included are preferably substituents selected from the substituent group Z described above.

[0549] Further optimized R 49 R 50 Each of these groups is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms that can be replaced by an alkyl group having 1 to 20 carbon atoms. Here, an aryl group having 6 to 30 carbon atoms refers to a monocyclic, bicyclic, tricyclic, or multiple monocyclic, bicyclic, or tricyclic groups connected together.

[0550] From the perspective of ease of manufacture, g and h are preferably 0; from the perspective of improving solubility, g or h are preferably 1 or 2, and more preferably 1.

[0551] R 51 ~R 53 Each of the following can independently represent a hydrogen atom, an alkyl group with 1 to 20 carbon atoms that can be substituted by a fluorine atom, a phenyl group that can be substituted by an alkyl group with 1 to 20 carbon atoms, or a halogen atom, preferably R. 51 and R 53 It is methyl or tert-butyl, R 52 It consists of hydrogen atoms, alkyl groups with 1 to 20 carbon atoms, or phenyl groups.

[0552] From a durability perspective, Ring B 40 Preferably, it is a pyridine ring, a pyrimidine ring, or an imidazole ring, and more preferably a pyridine ring.

[0553] From the perspectives of durability and improved solubility, cyclic B... 40 The hydrogen atoms on the surface are preferably replaced by alkyl groups with 1 to 20 carbon atoms, heteroaryl groups with 7 to 40 carbon atoms, or heteroaryl groups with 3 to 20 carbon atoms.

[0554] From the perspective of ease of manufacturing, ring B 40 The hydrogen atoms on the surface are preferably not substituted.

[0555] Ring B 40 The hydrogen atoms on the phenyl group readily generate excitons when used as organic electroluminescent elements. Therefore, from the perspective of improving luminous efficiency, they are preferably substituted with phenyl or naphthyl groups, which can have substituents. The substituents that the phenyl or naphthyl group can have are preferably selected from the substituent group Z described above.

[0556] Ring B 40Excitons are easily generated on auxiliary dopants, therefore, from the perspective of improving luminescence efficiency, quinoline rings, isoquinoline rings, quinazoline rings, quinoxaline rings, azirtriphenylene rings, and carbline rings are preferred. Among these, from the perspective of durability and displaying red luminescence, quinoline rings, isoquinoline rings, and quinazoline rings are more preferred.

[0557] Further optimized ring B 40 The substituent is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms that can be replaced by an alkyl group having 1 to 20 carbon atoms. Here, an aryl group having 6 to 20 carbon atoms refers to a monocyclic, bicyclic, tricyclic, or multiple monocyclic, bicyclic, or tricyclic groups connected together.

[0558] For the light-emitting dopant contained in the light-emitting layer, which is an aspect of the present invention, i.e., the compound represented by formula (40), R is preferred. 44 It is a compound of phenyl that can have substituents, namely the compound shown in the following formula (40-1).

[0559]

[0560] In the above formula, R 41 R 42 R 43 a40, b40, c40, L 1 m40 and R in equation (40) 41 R 42 R 43 a40, b40, c40, L 1 m40 and m40 have the same meaning.

[0561] R 45 With R 43 The meaning is the same, R 43 With R 45 They can be the same or different. When there are multiple R... 43 R 45 In this case, they can be the same or different.

[0562] d40 is an integer from 0 to 5.

[0563] From a durability perspective, R 43 R 45 Preferably, it is an alkyl group with 1 to 20 carbon atoms, a heteroaryl group with 7 to 40 carbon atoms, an arylamino group with 6 to 20 carbon atoms, or a heteroaryl group with 3 to 30 carbon atoms; more preferably, it is an alkyl group with 1 to 20 carbon atoms, a heteroaryl group with 7 to 40 carbon atoms, or a heteroaryl group with 3 to 20 carbon atoms; and even more preferably, it is an alkyl group with 1 to 20 carbon atoms or an aryl group with 7 to 40 carbon atoms.

[0564] R 43 R 45 The substituents that may be further included are preferably substituents selected from the substituent group Z described above.

[0565] From the perspective of ease of manufacture, c40 and d40 are preferably 0; from the perspective of improving durability and solubility, they are preferably 1 or 2, and more preferably 1. From the perspective of ease of manufacture, b40 is preferably 0; from the perspective of improving solubility, it is preferably 1.

[0566] As one aspect of the present invention, the light-emitting dopant represented by formula (40) contained in the light-emitting layer is preferably a40 is 2 or more and adjacent R 41 They bond together to form a fluorene ring structure. Preferably, the compound is represented by the following formula (40-2).

[0567]

[0568] In the above formula, R 42 ~R 44 b40, c40, L 1 m40 and R in equation (40) 42 ~R 44 b40, c40, L 1 m40 and m40 have the same meaning.

[0569] R 54 ~R 56 For substituents. In the presence of multiple R... 54 ~R 56 In this case, they can be the same or different.

[0570] i40 is an integer from 0 to 4.

[0571] R 54 It is a replacement for R 51 R when it is phenyl 51 The substituents on the surface are preferably selected from the substituent group Z described above. 54 More preferably, it is an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms that can be replaced by an alkyl group having 1 to 20 carbon atoms. Here, an aromatic hydrocarbon group having 6 to 30 carbon atoms refers to a monocyclic, 2 to 4-cyclic fused ring, or a group consisting of multiple monocyclic or 2 to 4-cyclic fused rings connected together. R 54 Further preferred are alkyl groups having 1 to 20 carbon atoms, and even more preferred are alkyl groups having 1 to 8 carbon atoms.

[0572] R 55 R 56 It is a replacement for R41 Part of or R 41 R when it is methyl 41 The substituents on the group are preferably each independently an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms that can be replaced by an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms that can be replaced by an alkoxy group having 1 to 20 carbon atoms. Here, an aromatic hydrocarbon group having 6 to 30 carbon atoms refers to a monocyclic, 2 to 4-cyclic fused ring, or a group consisting of multiple monocyclic or 2 to 4-cyclic fused rings connected together. R 55 R 56 More preferably, it is an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 or 12 carbon atoms that can be replaced by an alkyl group having 1 to 20 carbon atoms. More preferably, it is an alkyl group having 1 to 8 carbon atoms, or an aromatic hydrocarbon group having 6 carbon atoms that can be replaced by an alkyl group having 1 to 8 carbon atoms. Here, the aromatic hydrocarbon structure having 6 carbon atoms is a benzene structure, and the aromatic hydrocarbon structure having 12 carbon atoms is a biphenyl structure.

[0573] As R 54 ~R 56 Specific examples of preferred alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, isopropyl, isobutyl, isopentyl, tert-butyl, cyclohexyl, 2-ethylhexyl, etc.

[0574] As R 54 ~R 56 Specific examples of preferred aromatic hydrocarbon groups include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetraphenylene rings, pyrene rings, benzo[a]pyrene rings, etc. Monovalent groups such as cyclic rings, triphenyl rings, fluoranthene rings, biphenyl, and terphenyl.

[0575] As R 54 ~R 56 Specific examples of preferred alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, hexoxy, cyclohexoxy, octadecyloxy, etc.

[0576] As an embodiment of the present invention, the compound represented by formula (40-1) contained in the light-emitting layer as a light-emitting dopant is further preferably a compound represented by formula (40-3).

[0577]

[0578] In the above formula, R 42 R 43 R 45 b40, c40, d40, L 1 m40 and R in equation (40-1) 42 R43 R 45 b40, c40, d40, L 1 m40 and m40 have the same meaning.

[0579] R 54 ~R 56 i40 and R in equation (40-2) 54 ~R 56 i40 and i40 have the same meaning.

[0580] The following are preferred examples of compounds of formula (40) that serve as luminescent dopants contained in the luminescent layer as an embodiment of the invention, other than those shown in the examples, but the invention is not limited to these.

[0581]

[0582]

[0583]

[0584] [Hole transport layer]

[0585] The hole transport layer of the organic electroluminescent element of the present invention (hereinafter, sometimes referred to as "the hole transport layer of this embodiment") preferably contains the polymer of this embodiment as a material containing part of structure A.

[0586] The hole transport layer of this embodiment may contain one of the polymers of this embodiment, or may contain two or more polymers in any combination and any ratio.

[0587] The content of the polymer in the hole transport layer of this embodiment is typically 1 to 100% by weight, preferably 5 to 100% by weight, and more preferably 10 to 100% by weight. If it is within the above range, the charge transport property of the hole transport layer of this embodiment is improved, the driving voltage is reduced, and the driving stability is improved, which is therefore preferred.

[0588] In cases where the polymer in this embodiment is not 100% by weight in the hole transport layer of this embodiment, hole transport compounds, etc., can be cited as components constituting the hole transport layer of this embodiment.

[0589] From the perspective of easily manufacturing organic electroluminescent elements, the polymer of this embodiment is preferably used in the hole transport layer of this embodiment formed by a wet film deposition method. The method for forming the hole transport layer by the wet film deposition method will be described later.

[0590] [Composition for forming a hole transport layer]

[0591] The hole transport layer forming composition for forming the hole transport layer of this embodiment by wet film deposition contains the polymer described in this embodiment. The hole transport layer forming composition of this embodiment may contain one of the above-described polymers, or may contain two or more of them in any combination and any ratio.

[0592] [Polymer content]

[0593] The content of the polymer in the hole transport layer formation composition of this embodiment is generally 0.01 to 70% by weight, preferably 0.1 to 60% by weight, and more preferably 0.5 to 50% by weight.

[0594] If the hole transport layer is within the above range, it is less likely to have defects and uneven film thickness, and is therefore preferred.

[0595] In addition to the polymer described above, the composition for forming the hole transport layer in this embodiment may also contain solvents or the like.

[0596] [solvent]

[0597] The hole transport layer formation composition of this embodiment typically contains a solvent. The solvent is preferably used to dissolve the polymer. Specifically, a solvent that dissolves the polymer at room temperature is preferred, typically 0.05% by weight or more, preferably 0.5% by weight or more, and more preferably 1% by weight or more.

[0598] 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 2,3-dimethoxybenzene. - Ether solvents such as aromatic ethers like dimethyl anisole and 2,4-dimethyl anisole; 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 other organic solvents used in the hole injection layer formation composition or hole transport layer formation composition described below.

[0599] One solvent can be used, or two or more solvents can be used in any combination and in any ratio.

[0600] The solvent contained in the hole transport layer formation composition of this embodiment is preferably a solvent with a surface tension of less than 40 dyn / cm at 20°C, more preferably 36 dyn / cm or less, and more preferably 33 dyn / cm or less.

[0601] When forming a hole transport layer using the hole transport layer composition of this embodiment and forming a coating film by a wet film deposition method, thereby crosslinking the aforementioned polymer to form a hole transport layer, a high affinity between the solvent and the substrate is preferable. This is because the uniformity of the film has a significant impact on the uniformity and stability of light emission from the organic electroluminescent element. Therefore, the hole transport layer formation composition used in the wet film deposition method requires low surface tension in order to form a coating film with higher leveling properties and uniformity. Therefore, by using a solvent with low surface tension as described above, a uniform layer containing the aforementioned polymer can be formed, and consequently, a uniform crosslinked layer can be formed, which is therefore preferable.

[0602] Specific examples of solvents with low surface tension include aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene; aromatic ester solvents such as ethyl benzoate; aromatic ether solvents such as anisole; trifluoromethoxyanisole; pentafluoromethoxybenzene; 3-(trifluoromethyl)anisole; and ethyl (pentafluorobenzoate).

[0603] On the other hand, the solvent contained in the hole transport layer forming composition of this embodiment 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, a hole transport layer forming composition suitable for a process of manufacturing a hole transport layer by a wet film deposition method and suitable for the properties of the polymer of this embodiment can be prepared.

[0604] To obtain a more uniform film, it is preferable that the solvent evaporates from the liquid film immediately after film formation at an appropriate rate. Therefore, the boiling point of the solvent used is as described above, typically 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and typically 350°C or lower, preferably 300°C or lower, more preferably 280°C or lower.

[0605] Specific examples of such solvents include the aforementioned aromatic solvents such as mesitylene and cyclohexylbenzene, aromatic ether solvents, and aromatic ester solvents.

[0606] Moisture can cause performance degradation in organic electroluminescent elements, particularly potentially leading to a decrease in brightness during continuous operation. Therefore, in order to minimize residual moisture in wet film formation, the solvents used are preferably solvents with a water solubility of 1% by weight or less at 25°C, and more preferably solvents with a solubility of 0.1% by weight or less.

[0607] The solvent content in the hole transport layer formation composition of this embodiment is typically 10% by weight or more, preferably 30% by weight or more, and particularly preferably 50% by weight or more. By ensuring that the solvent content is at or above the aforementioned lower limit, the flatness and uniformity of the formed layer can be achieved.

[0608] [Electron-accepting compounds]

[0609] From the viewpoint of reducing resistance, the composition for forming the hole transport layer in this embodiment may further contain an electron-accepting compound.

[0610] As an electron-accepting compound, a compound having oxidizing power and the ability to accept an electron from the aforementioned polymer is preferred. Specifically, compounds with an electron affinity of 4 eV or higher are preferred, and compounds with an electron affinity of 5 eV or higher are even more preferred.

[0611] Examples of such electron-accepting compounds include, for example, triarylboron compounds, metal halides, Lewis acids, organic acids, and... Compounds of one or more of the following: salts, salts of aryl amines and metal halides, and salts of aryl amines and Lewis acids.

[0612] Specifically, 4-isopropyl-4'-methyldiphenyliodide can be cited as an example. Tetra(pentafluorophenyl)borate, triphenylsulfonium tetrafluoroborate, etc., have undergone organic group substitution. Salts (International Publication No. 2005 / 089024), (International Publication No. 2017 / 164268); ferric chloride (III) (Japanese Patent Application Publication No. 11-251067), ammonium peroxydisulfate and other high-valence inorganic compounds; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris(pentafluorophenyl)borane (Japanese Patent Application Publication No. 2003-31365); fullerene derivatives and iodine, etc.

[0613] The hole transport layer formation composition of this embodiment may contain one of the electron accepting compounds described above, or it may contain two or more in any combination and ratio.

[0614] In the case where the hole transport layer formation composition of this embodiment contains an electron accepting compound, the content of the electron accepting compound is generally 0.0005% by weight or more, preferably 0.001% by weight or more, and generally 20% by weight or less, preferably 10% by weight or less.

[0615] The proportion of the electron-accepting compound in the composition for forming the hole transport layer relative to the polymer is generally 0.5% by weight or more, preferably 1% by weight or more, more preferably 3% by weight or more, and generally 80% by weight or less, preferably 60% by weight or less, and even more preferably 40% by weight or less.

[0616] If the content of the electron-accepting compound in the composition for forming the hole transport layer is at or above the lower limit mentioned above, the electron acceptor accepts electrons from the polymer, resulting in a low-resistivity hole transport layer, which is therefore preferred. If the content of the electron-accepting compound in the composition for forming the hole transport layer is below the upper limit mentioned above, the formed hole transport layer is less prone to defects and uneven film thickness, which is also preferred.

[0617] [Cat radical compounds]

[0618] The hole transport layer formation composition of this embodiment may further contain cationic free radical compounds.

[0619] As a cationic radical compound, it is preferable to form an ionic compound consisting of a cationic radical, which is a chemical species that has removed an electron from a hole-transporting compound, and a counter anion. In the case where the cationic radical originates from a hole-transporting polymer, the cationic radical becomes a structure that has removed an electron from a repeating unit of the polymer.

[0620] As a cation radical, it is preferably a chemical species that has removed one electron from a hole-transporting compound, as described later. From the perspectives of amorphousness, visible light transmittance, heat resistance, and solubility, it is preferable to use a chemical species that has removed one electron from a compound that is preferred as a hole-transporting compound.

[0621] Here, cationic radical compounds can be generated by mixing the hole-transporting compound (described later) with the electron-accepting compound described above. That is, by mixing the hole-transporting compound and the electron-accepting compound, electrons move 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.

[0622] In the case where the hole transport layer formation composition of this embodiment contains a cationic radical compound, the content of the cationic radical compound in the hole transport layer formation composition is typically 0.0005% by weight or more, preferably 0.001% by weight or more, and typically 40% by weight or less, preferably 20% by weight or less. If the content of the cationic radical compound is at or above the lower limit, the formed hole transport layer has low resistance, which is therefore preferred. If the content of the cationic radical compound is at or below the upper limit, the formed hole transport layer is less prone to defects and less prone to uneven film thickness, which is also preferred.

[0623] In the hole transport layer forming composition of this embodiment, in addition to the above-described components, the components contained in the hole injection layer forming composition or the hole transport layer forming composition may also be included in the amounts described later.

[0624] [Emitting layer]

[0625] The light-emitting layer of the organic electroluminescent element of the present invention (hereinafter, sometimes referred to as "the light-emitting layer of this embodiment") preferably contains the low molecular weight compound of this embodiment as a material containing a portion of structure A.

[0626] The light-emitting layer of this embodiment may contain one of the low-molecular-weight compounds of this embodiment, or may contain two or more in any combination and any ratio.

[0627] The light-emitting layer of this embodiment includes at least the low molecular weight compound and the light-emitting material of this embodiment, with the low molecular weight compound serving as the main material of the light-emitting material.

[0628] Phosphorescent or fluorescent materials can be used as luminescent materials.

[0629] The content of luminescent material contained in the luminescent layer of the present invention is typically 0.1% to 50% by weight, preferably 0.2% to 40% by weight, and more preferably 0.5% to 35% by weight. High luminous efficiency can be obtained if the content of luminescent material is within the above range.

[0630] In this embodiment, the content of the low-molecular-weight compound in the light-emitting layer, calculated based on the content of materials other than the light-emitting material, is typically 5% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more, particularly preferably 30% by weight or more, typically 100% by weight or less, preferably 90% by weight or less, more preferably 80% by weight or less, and particularly preferably 70% by weight or less. If it falls within the above range, the charge transport properties of the light-emitting layer in this embodiment are considered to be improved, the driving voltage to be reduced, and the driving stability to be improved, therefore it is preferred.

[0631] In the case where the light-emitting layer of this embodiment contains components other than the light-emitting material and the low-molecular-weight compound of this embodiment, examples of other components include charge transport materials, which will be described later. The content of other components, such as the charge transport material, in the light-emitting layer of this embodiment is generally 0% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more, particularly preferably 30% by weight, and generally 95% by weight or less, preferably 90% by weight or less, more preferably 80% by weight or less, and particularly preferably 70% by weight or less. It is believed that if the above range is met, the carrier balance between electrons and holes in the light-emitting layer is good, the luminous efficiency is improved, the charge transport is improved, the voltage is reduced, and the driving stability is improved, therefore this is preferable.

[0632] From the perspective of easily manufacturing organic electroluminescent elements, the low-molecular-weight compound of this embodiment is preferably used in the light-emitting layer of this embodiment formed by a wet film deposition method. The method for forming the light-emitting layer using the wet film deposition method will be described later.

[0633] [Composition for forming a light-emitting layer]

[0634] The composition for forming the light-emitting layer of this embodiment by wet film deposition contains the low-molecular-weight compound described in this embodiment. The composition for forming the light-emitting layer of this embodiment may contain one of the aforementioned low-molecular-weight compounds, or may contain two or more compounds in any combination and ratio.

[0635] [Content of low molecular weight compounds]

[0636] The total content of the above-mentioned low molecular weight compound, luminescent material, charge transport material and other solid components in the composition for forming the light-emitting layer in this embodiment is generally 0.01% to 70% by weight, preferably 0.1% to 60% by weight, and more preferably 0.5% to 50% by weight.

[0637] If the light-emitting layer is within the above range, it is less likely to produce defects and uneven film thickness, and is therefore preferred.

[0638] In addition to the low molecular weight compound, luminescent material, charge transport material, and other components mentioned above, the composition for forming the light-emitting layer in this embodiment may also contain solvents, etc.

[0639] [solvent]

[0640] The composition for forming the light-emitting layer in this embodiment typically contains a solvent.

[0641] As a solvent, it can be selected from the same solvent contained in the composition for forming the hole transport layer described above. The required properties of the solvent are also the same, and the preferred solvent is also the same.

[0642] The amount of solvent used is arbitrary as long as it does not significantly impair the effect of the present invention, but it is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 50% by mass or more, and preferably 99.99% by mass or less, more preferably 99.9% by mass or less, and particularly preferably 99% by mass or less, based on its content in the composition for forming the light-emitting layer.

[0643] [Phosphorescent emissive layer]

[0644] In the case where the light-emitting layer in this embodiment is a phosphorescent light-emitting layer containing a phosphorescent material as the light-emitting material, the following materials are preferred as the phosphorescent light-emitting material.

[0645] <Phosphorescent materials>

[0646] Phosphorescent materials are materials that exhibit luminescence from an excited triplet state. For example, metal coordination compounds containing Ir, Pt, Eu, etc., are representative examples, and the structure of such materials preferably includes metal coordination compounds.

[0647] Among metal complexes, phosphorescent organometallic complexes that emit light via a triplet state are examples of Werner-type complexes or organometallic coordination compounds containing metals 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 those represented by formula (205) below are preferred, and compounds represented by formula (201) below are more preferably preferred.

[0648] [The compound represented by formula (201)]

[0649]

[0650] In formula (201), ring A1 represents an aromatic hydrocarbon ring structure that may have substituents or an aromatic heterocyclic structure that may have substituents.

[0651] Ring A2 represents an aromatic heterocyclic structure that can have substituents.

[0652] R 201 R 202 Each is independently represented by the structure shown in equation (202). "*" indicates the bonding site with ring A1 or ring A2. R 201 R 202 They can be the same or different. In R 201R 202 When multiple instances exist, they can be the same or different.

[0653] Ar 201 Ar 203 Each can independently represent an aromatic hydrocarbon structure that may have substituents or an aromatic heterocyclic structure that may have substituents.

[0654] Ar 202 This indicates an aromatic hydrocarbon structure that can have substituents, an aromatic heterocyclic structure that can have substituents, or an aliphatic hydrocarbon structure that can have substituents.

[0655] Substituents bonded to ring A1, substituents bonded to ring A2, or substituents bonded to ring A1 and substituents bonded to ring A2 can also bond to each other to form a ring.

[0656] B 201 -L 200 -B 202 B indicates 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 the atomic group that constitutes the bidentate ligand. In B 201 -L 200 -B 202 When multiple instances exist, they can be the same or different.

[0657] i1 and i2 each independently represent integers greater than 0 and less than 12.

[0658] i3 is a potential replacement for Ar 202 The quantity is an integer greater than or equal to 0, which is the upper limit.

[0659] j1 is a replacement for Ar 201 The quantity is an integer greater than or equal to 0, which is the upper limit.

[0660] k1 and k2 are each independent integers greater than 0 that represent the number of rings A1 and A2 that can be replaced by rings A1 and A2 as the upper limit.

[0661] m1 is an integer from 1 to 3.

[0662] Unless otherwise specified, the substituents described above are preferably selected from the substituent group Z' below.

[0663] <Substituted base set Z'>

[0664] 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.

[0665] • Alkoxy group: preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and even more preferably an alkoxy group having 1 to 6 carbon atoms.

[0666] • 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.

[0667] • Heteroaryloxy group: preferably a heteroaryloxy group with 3 to 20 carbon atoms, more preferably a heteroaryloxy group with 3 to 12 carbon atoms.

[0668] • Alkylamino group: preferably an alkylamino group having 1 to 20 carbon atoms, more preferably an alkylamino group having 1 to 12 carbon atoms.

[0669] • Arylamino group: preferably an arylamino group with 6 to 36 carbon atoms, more preferably an arylamino group with 6 to 24 carbon atoms.

[0670] • 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.

[0671] • Heteroaryl groups: preferably heteroaryl groups with 4 to 40 carbon atoms, more preferably heteroaryl groups with 4 to 18 carbon atoms.

[0672] • Alkenyl group: preferably an alkenyl group with 2 to 20 carbon atoms, more preferably an alkenyl group with 2 to 12 carbon atoms, even more preferably an alkenyl group with 2 to 8 carbon atoms, and particularly preferably an alkenyl group with 2 to 6 carbon atoms.

[0673] • Alkyne group: preferably an alkyne group with 2 to 20 carbon atoms, more preferably an alkyne group with 2 to 12 carbon atoms.

[0674] • Aryl group: preferably an aryl group with 6 to 30 carbon atoms, more preferably an aryl group with 6 to 24 carbon atoms, even more preferably an aryl group with 6 to 18 carbon atoms, and particularly preferably an aryl group with 6 to 14 carbon atoms.

[0675] • Heteroaryl group: preferably a heteroaryl group with 3 to 30 carbon atoms, more preferably a heteroaryl group with 3 to 24 carbon atoms, even more preferably a heteroaryl group with 3 to 18 carbon atoms, and particularly preferably a heteroaryl group with 3 to 14 carbon atoms.

[0676] • Alkylsilyl group: preferably an alkylsilyl group having 1 to 20 carbon atoms, more preferably an alkylsilyl group having 1 to 12 carbon atoms.

[0677] • Arylsilyl group: preferably an arylsilyl group having 6 to 20 carbon atoms, more preferably an arylsilyl group having 6 to 14 carbon atoms.

[0678] • Alkyl carbonyl group: preferably an alkyl carbonyl group with 2 to 20 carbon atoms

[0679] • Aryl carbonyl group: preferably an aryl carbonyl group with 7 to 20 carbon atoms

[0680] Regarding the substituents mentioned above, one or more hydrogen atoms can be replaced by fluorine atoms, or one or more hydrogen atoms can be replaced by deuterium atoms.

[0681] Unless otherwise specified, aryl groups are aromatic hydrocarbon groups, and heteroaryl groups are aromatic heterocyclic groups.

[0682] • Hydrogen atom, deuterium atom, fluorine atom, cyano group or -SF5

[0683] (Preferred groups in substituent group Z')

[0684] In the above substituent group Z',

[0685] Preferably, alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, alkylsilyl, arylsilyl, and groups in which one or more hydrogen atoms are substituted by fluorine atoms, fluorine atoms, cyano, -SF5,

[0686] More preferably, alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, and groups in which one or more hydrogen atoms are substituted by fluorine atoms, fluorine atoms, cyano, -SF5,

[0687] Further preferred are alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, and heteroaryl.

[0688] Particularly preferred are alkyl, arylamino, aralkyl, alkenyl, aryl, and heteroaryl groups.

[0689] The most preferred compounds are alkyl, arylamino, aralkyl, aryl, and heteroaryl.

[0690] (Substituents replacing Z')

[0691] These substituent groups Z' may further have substituents selected from those in substituent group Z'. 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'.

[0692] <Ring A1>

[0693] Ring A1 represents an aromatic hydrocarbon ring structure that may have substituents or an aromatic heterocyclic structure that may have substituents.

[0694] The aromatic hydrocarbon ring, which is ring A1, is preferably an aromatic hydrocarbon ring with 6 to 30 carbon atoms. Specifically, it is preferably a benzene ring, a naphthalene ring, an anthracene ring, a triphenylene ring, an acenaphthene ring, a fluorene ring, or a benzene ring.

[0695] 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.

[0696] 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.

[0697] <Ring A2>

[0698] Ring A2 represents an aromatic heterocyclic structure that can have substituents.

[0699] As an aromatic heterocycle of ring A2, it is preferably an aromatic heterocycle with 3 to 30 carbon atoms, including any one of nitrogen, oxygen, or sulfur atoms as heteroatoms. Specifically, examples include pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, imidazole rings, etc. 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.

[0700] (Combination of ring A1 and ring A2)

[0701] As a preferred combination of ring A1 and ring A2, if expressed as (ring A1-ring A2), then it is (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-imidazolium ring), (benzene ring-benzothiazole ring).

[0702] (Substituents in ring A1 and ring A2)

[0703] The substituents that ring A1 and ring A2 may have can be arbitrarily selected, but are preferably one or more substituents selected from the substituent group Z' mentioned above.

[0704] <Ar 201 Ar 202 Ar 203 >

[0705] 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.

[0706] 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.

[0707] (Ar 201 Ar 202 Ar 203 (aromatic hydrocarbon ring)

[0708] In Ar 201 Ar 202 Ar 203 When any of the components is an aromatic hydrocarbon structure that can have substituents, the aromatic hydrocarbon structure is preferably an aromatic hydrocarbon ring with 6 to 30 carbon atoms. Specifically, examples include benzene rings, naphthalene rings, anthracene rings, triphenylene rings, acenaphthene rings, fluoranthene rings, and fluorene rings, with benzene rings, naphthalene rings, and fluorene rings being more preferred, and benzene rings being the most preferred.

[0709] (9,9' of the eu)

[0710] In Ar 201 Ar 202 Ar 203 In the case that either of the fluorene rings can have substituents, the 9th and 9' positions of the fluorene ring are preferably substituents or bonded to adjacent structures.

[0711] (o-phenylene, m-phenylene)

[0712] In Ar 201 Ar 202 When either of the benzene rings can have substituents, it is preferable that at least one benzene ring is bonded to the adjacent structure at the ortho or meta position, and more preferably at least one benzene ring is bonded to the adjacent structure at the meta position.

[0713] (Ar 201 Ar202 Ar 203 (aromatic heterocycles)

[0714] In 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, including any one of 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.

[0715] (N position of carbazole)

[0716] In Ar 201 Ar 202 Ar 203 In the case where 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.

[0717] (Ar 202 (aliphatic hydrocarbons)

[0718] In Ar 202 When the aliphatic hydrocarbon structure can have substituents, it is a straight-chain, branched-chain, or cyclic aliphatic hydrocarbon structure, preferably with 1 or more and 24 or less carbon atoms, more preferably with 1 or more and 12 or less carbon atoms, and more preferably with 1 or more and 8 or less carbon atoms.

[0719] <i1, i2, i3, j1, k1, k2>

[0720] (The preferred range of i1 and i2)

[0721] i1 represents an integer from 0 to 12, preferably 1 to 12, more preferably 1 to 8, and even more preferably an integer from 1 to 6. By using this range, it is expected to improve solubility and charge transport properties.

[0722] (Preferred range of i3)

[0723] i3 preferably represents an integer from 0 to 5, more preferably from 0 to 2, and even more preferably 0 or 1.

[0724] (The preferred range of j1)

[0725] j1 preferably represents an integer from 0 to 2, and more preferably 0 or 1.

[0726] (The preferred range of k1 and k2)

[0727] 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.

[0728] <Ar 201 Ar 202 Ar 203 Preferred substituents >

[0729] Ar 201 Ar 202 Ar 203 The substituents that can be present can be chosen arbitrarily, but are preferably one or more substituents selected from the substituent group Z' described above. Preferred groups are also as shown in the substituent group Z' described above, more preferably hydrogen atoms, alkyl groups, aryl groups, particularly preferably hydrogen atoms, alkyl groups, and most preferably unsubstituted (hydrogen atoms).

[0730] <Preferred structure of formula (201)>

[0731] Of the compounds shown in the above formula (201), compounds having the following structure are preferred.

[0732] (Phenylidene-linked)

[0733] It has a structure with groups formed by the linkage of benzene rings.

[0734] That is, Ar 201 It has a benzene ring structure, i1 is 1 to 6, and at least one of the above benzene rings is bonded to the adjacent structure at the ortho or meta position.

[0735] By adopting this structure, improved solubility and charge transport can be expected.

[0736] ((phenylene)-(aryl)-(alkyl))

[0737] It has a structure in which an aromatic hydrocarbon group or an aromatic heterocyclic group is bonded to an alkyl or aralkyl group in ring A1 or ring A2.

[0738] That is, Ar 201 It has an aromatic hydrocarbon structure or an aromatic heterocyclic structure, i1 is 1 to 6, Ar 202 It has an aliphatic hydrocarbon structure, i2 is 1-12, preferably 3-8, and Ar 203 It has a benzene ring structure, and i3 is 0 or 1.

[0739] Preferred Ar 201The structure is an aromatic hydrocarbon as described above, and is more preferably a structure consisting of 1 to 5 benzene rings, and more preferably a single benzene ring.

[0740] By adopting this structure, improved solubility and charge transport can be expected.

[0741] (dendritic)

[0742] The structure has dendrites bonded to ring A1 or ring A2.

[0743] For example, Ar, Ar 202 It has a benzene ring structure, Ar 203 It has a biphenyl or triphenyl biphenyl structure, i1 and i2 are 1 to 6, i3 is 2, and j is 2.

[0744] By adopting this structure, improved solubility and charge transport can be expected.

[0745] <B 201 -L 200 -B 202 >

[0746] B 201 -L 200 -B 202 B indicates 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 the atomic group that constitutes the bidentate ligand. In B 201 -L 200 -B 202 When multiple instances exist, they can be the same or different.

[0747] B 201 -L 200 -B 202 The structure shown is preferably the structure shown in formula (203) or formula (204) below.

[0748]

[0749] (In equation (203), R) 211 R 212 R 213 (Indicates substituent)

[0750]

[0751] (In formula (204), ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom that may have substituents. Ring B3 is preferably a pyridine ring.)

[0752] <Preferred phosphorescent material according to formula (201)>

[0753] The phosphorescent material represented by formula (201) is not particularly limited, but the following structures can be specifically cited. Hereinafter, "Ph" means "phenyl" and "Me" means "methyl".

[0754]

[0755]

[0756]

[0757]

[0758] [The compound shown in formula (205)]

[0759]

[0760] In equation (205), M 2 It represents a metal. T represents a carbon atom or a nitrogen atom. R 92 ~R 95 Each substituent can be represented independently. Specifically, when T is a nitrogen atom, R does not exist. 94 and R 95 .

[0761] In equation (205), M 2 The term "metal" can be used as a specific example. Metals selected from groups 7 to 11 of the periodic table can be cited as examples. 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.

[0762] 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.

[0763] When T is a carbon atom, R 94 and R 95 Each is independently represented by R. 92 and R 93 The same example represents the substituent.

[0764] When T is a nitrogen atom, there is no R directly bonded to T. 94 or R 95 .

[0765] R 92 ~R 95 It may also have substituents. The substituents can be those described above.

[0766] R 92 ~R 95 Any two or more groups in it can also connect with each other to form a ring.

[0767] <Molecular weight of phosphorescent materials>

[0768] The molecular weight of the phosphorescent material is preferably below 5000, more preferably below 4000, particularly preferably below 3000, typically above 800, preferably above 1000, and more preferably above 1200. It is believed that within this molecular weight range, a phosphorescent layer with high luminous efficiency can be obtained where the phosphorescent materials do not aggregate but are uniformly mixed with the charge transport material, resulting in a luminescent layer that exhibits no luminescence.

[0769] From the perspectives of high Tg or melting point, decomposition temperature, excellent heat resistance of the phosphorescent material and the formed luminescent layer, and less likelihood of film quality degradation or impurity concentration increase due to thermal decomposition of the material caused by gas generation, recrystallization, and molecular migration, a large molecular weight is preferred for phosphorescent materials. On the other hand, from the perspective of ease of purification of organic compounds, a small molecular weight is preferred for phosphorescent materials.

[0770] [Main material for phosphorescent emitting layer]

[0771] The light-emitting layer of this embodiment contains the low molecular weight compound of this embodiment as the main material. When the light-emitting layer is a phosphorescent light-emitting layer, it is preferable to include the following materials as other main materials.

[0772] 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 capable of transporting both electrons and holes.

[0773] (A framework with excellent charge transport properties)

[0774] 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, phenanthrene-rholine structures, quinoline structures, pyridine structures, pyrimidine structures, and triazine structures. Diazole or imidazole structures, etc.

[0775] (Electron transport materials)

[0776] From the viewpoint of being a material with excellent electron transport properties and relatively stable structure, compounds having pyridine, pyrimidine, or triazine structures are more preferred as electron transport materials, and compounds having pyrimidine or triazine structures are even more preferred as electron transport materials.

[0777] (Hole-transporting materials)

[0778] Hole-transporting materials are compounds with excellent hole-transporting structures. In the aforementioned central framework with excellent charge transporting properties, the structure with excellent hole transporting properties is preferably a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure, or a pyrene structure, and more preferably a carbazole structure, a dibenzofuran structure, or a triarylamine structure.

[0779] (Fused ring structure with three or more rings)

[0780] The host material of the luminescent layer preferably has a fused ring structure with three or more rings, and more preferably a compound having two or more fused rings with three or more rings or a compound having at least one fused ring with five or more rings. With these compounds, the following effects are easily obtained: increased molecular rigidity and suppression of the degree of molecular motion in response to heat. Furthermore, from the perspective of charge transport and material durability, fused rings with three or more rings and fused rings with five or more rings preferably have aromatic hydrocarbon rings or aromatic heterocycles.

[0781] Examples of fused ring structures with three or more rings include anthracene, phenanthrene, and pyrene structures. The structure includes, but is not limited to, tetraphenyl, triphenylene, fluorene, benzo[a]fluorene, indo[a]fluorene, indole[a]fluorene, carbazole, indo[a]carbazole, indole[a]carbazole, dibenzofuran, and dibenzothiophene structures. From the viewpoint of charge transport and solubility, at least one of the following structures is preferred: phenanthrene, fluorene, indo[a]fluorene, carbazole, indo[a]carbazole, indole[a]carbazole, dibenzofuran, and dibenzothiophene. From the viewpoint of durability relative to charge, a carbazole or indole[a]carbazole structure is further preferred.

[0782] From the viewpoint of the durability of organic electroluminescent elements against charge, it is preferable that at least one of the host materials of the light-emitting layer is a material having a pyrimidine framework or a triazine framework.

[0783] (Molecular weight range)

[0784] From the viewpoint of excellent flexibility, the main material of the light-emitting layer is preferably a polymer material. A light-emitting layer formed using a highly flexible material is preferred as 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 or more and 1,000,000 or less, more preferably 10,000 or more and 500,000 or less, and even more preferably 10,000 or more and 100,000 or less.

[0785] From the viewpoints of ease of synthesis and purification, ease of design of 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 low molecular weight. When the host material contained in the light-emitting layer is low molecular weight, the molecular weight is preferably 5000 or less, more preferably 4000 or less, particularly preferably 3000 or less, most preferably 2000 or less, and generally 300 or more, preferably 350 or more, and more preferably 400 or more.

[0786] [Fluorescent Emitting Layer]

[0787] In the case where the light-emitting layer in this embodiment is a fluorescent light-emitting layer, it is preferable to use the following blue fluorescent light-emitting material as the fluorescent light-emitting material for the blue fluorescent light-emitting layer.

[0788] <Blue fluorescent materials>

[0789] The luminescent material used for the blue fluorescent luminescent layer is not particularly limited, but the compound shown in the following formula (211) is preferred.

[0790]

[0791] In the above equation (211), Ar 241 This indicates a fused-ring structure of aromatic hydrocarbons that can have substituents. Ar 242 Ar 243 Each can independently represent an alkyl group, an aromatic hydrocarbon group, or a group bonded with such a group that may have substituents. n41 is an integer from 1 to 4.

[0792] Ar 241 Preferably, the structure represents a fused ring structure of an aromatic hydrocarbon with 10 to 30 carbon atoms. Specific structures include naphthalene rings, acenaphthene rings, fluorene rings, anthracene rings, phenanthrene rings, fluoranthene rings, pyrene rings, and tetraphenyl rings. Rings, perylene rings, etc. More preferably, aromatic hydrocarbon fused ring structures with 12 to 20 carbon atoms. Specific structures include acenaphthene rings, fluorene rings, anthracene rings, phenanthrene rings, fluoranthene rings, pyrene rings, and tetraphenyl rings. Cyclic rings, perylene rings. More preferably, fused ring structures of aromatic hydrocarbons with 16-18 carbon atoms are preferred. Specific structures include fluoranthene rings, pyrene rings, and... ring.

[0793] n41 is an integer from 1 to 4, preferably from 1 to 3, further preferably from 1 to 2, and most preferably from 2.

[0794] (Ar 241 Ar 242 Ar 243 (substituents)

[0795] Ar 241 Ar 242 Ar 243 The substituents that may be present are preferably groups selected from the substituent group Z' above, more preferably hydrocarbon groups contained in the substituent group Z', and even more preferably hydrocarbon groups that are preferred as substituent group Z'.

[0796] [Main material for blue fluorescent emissive layer]

[0797] In the light-emitting layer of this embodiment, the low molecular weight compound of this embodiment is used as the main material for the light-emitting material. When using a blue fluorescent light-emitting material, the following materials are preferred as other main materials.

[0798] There are no particular limitations on the main material used for the blue fluorescent emitting layer, but the compound shown in the following formula (212) is preferred.

[0799]

[0800] In the above equation (212), R 241 R 242 Each is independently represented by the structure shown in equation (213) below. R 243 Indicates a substituent. In R 243 If multiple instances exist, they can be the same or different. n43 is an integer from 0 to 8.

[0801]

[0802] In the above equation (213), Ar 244 Ar 245 Each can independently represent an aromatic hydrocarbon structure that may have substituents or a heteroaromatic ring structure that may have substituents. In 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. n45 is an integer from 0 to 5.

[0803] Ar 244Preferably, it is an aromatic hydrocarbon structure with a single ring or fused ring having 6 to 30 carbon atoms and substituents; more preferably, it is an aromatic hydrocarbon structure with a single ring or fused ring having 6 to 12 carbon atoms and substituents.

[0804] Ar 245 Preferably, it is an aromatic hydrocarbon structure with a single ring or fused ring having 6 to 30 carbon atoms and substituents, or an aromatic heterocyclic structure with a fused ring having 6 to 30 carbon atoms and substituents. More preferably, it is an aromatic hydrocarbon structure with a single ring or fused ring having 6 to 12 carbon atoms and substituents, or an aromatic heterocyclic structure with a fused ring having 12 carbon atoms and substituents.

[0805] n44 is preferably an integer from 1 to 3, and more preferably 1 or 2.

[0806] n45 is preferably 0 to 3, and more preferably 0 to 2.

[0807] (R 243 Ar 244 Ar 245 (substituents)

[0808] R as a substituent 243 and Ar 244 and Ar 245 The substituents that may be present are preferably groups selected from the substituent group Z' above, more preferably hydrocarbon groups contained in the substituent group Z', and even more preferably hydrocarbon groups that are preferred as substituent group Z'.

[0809] (molecular weight)

[0810] The molecular weight of the luminescent material and its main material used in the blue fluorescent luminescent layer is preferably less than 5000, more preferably less than 4000, particularly preferably less than 3000, most preferably less than 2000, and generally more than 300, preferably more than 350, and more preferably more than 400.

[0811] [Organic electroluminescent devices]

[0812] The organic electroluminescent element of this embodiment is an organic electroluminescent element having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate. The organic layer is characterized in that the organic layer has a hole transport layer and a light-emitting layer adjacent to the hole transport layer, wherein at least one of the materials contained in the hole transport layer and at least one of the materials contained in the light-emitting layer are materials containing the same partial structure A.

[0813] The preferred forms of the hole transport layer of this embodiment, which includes a material containing a portion of structure A, and the light-emitting layer of this embodiment, which includes a material containing a portion of structure A, are as described above.

[0814] As an example of the structure of the organic electroluminescent element in this embodiment, in Figure 1 The diagram shows a cross-section of an example structure of the organic electroluminescent element 10. 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.

[0815] 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.

[0816] In this embodiment, wet film formation refers to a method of forming a film by using wet methods such as spin coating, dip coating, mold coating, bar coating, doctor blade coating, roller coating, spray coating, capillary coating, inkjet coating, nozzle printing, screen printing, gravure printing, and flexographic printing, and then drying the coated film to form a film. Among these film formation methods, spin coating, spray coating, inkjet printing, and nozzle printing are preferred.

[0817] [Substrate]

[0818] The substrate 1 serves as a support for the organic electroluminescent element and can typically be made of quartz or glass plates, metal plates or foils, plastic films or sheets, etc. Among these, plates made of transparent synthetic resins such as glass, polyester, polymethyl methacrylate, polycarbonate, and polysulfone are preferred. From the perspective of minimizing degradation of the organic electroluminescent element caused by external gases, the substrate is preferably made of a material with high gas barrier properties. Therefore, especially when using materials with low gas barrier properties such as substrates made of synthetic resins, 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.

[0819] [anode]

[0820] Anode 2 is responsible for injecting holes into the light-emitting layer 5.

[0821] 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.

[0822] The anode 2 is usually formed by dry methods such as sputtering and vacuum evaporation.

[0823] When using metal particles such as silver, copper iodide, carbon black, conductive metal oxide particles, or conductive polymer micropowders to form the anode, it can also be formed by dispersing them in a suitable binder resin solution and coating them onto a substrate.

[0824] In the case of conductive polymers, thin films can also be formed directly on the substrate by electrolytic polymerization, or an anode can be formed by coating the substrate with conductive polymers (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0825] Anode 2 is typically a single-layer structure, but a multilayer structure can also be appropriately adopted. In the case of a multilayer structure for anode 2, different conductive materials can be stacked on the first anode layer.

[0826] The thickness of anode 2 can be determined based on the required transparency and material properties. Particularly when high transparency is required, a thickness with a visible light transmittance of 60% or more is preferred, and a transmittance of 80% or more is even more preferred. The thickness of anode 2 is preferably 5 nm or more, more preferably 10 nm or more, and typically 1000 nm or less, more preferably 500 nm or less. When transparency is not required, the thickness of anode 2 can be any thickness as needed for required strength, etc. In this case, anode 2 can also be the same thickness as the substrate.

[0827] When other layers are formed on the surface of anode 2, it is preferable to perform ultraviolet / ozone, oxygen plasma, argon plasma or other treatments before film formation, thereby removing impurities on anode 2 and adjusting its ionization potential to improve hole injection capability.

[0828] [Hollow Injection Layer]

[0829] The layer that performs the function of transporting holes from the anode 2 side to the light-emitting layer 5 side is usually called the hole injection transport layer or hole transport layer. When there are two or more layers performing the function of transporting holes from the anode 2 side to the light-emitting layer 5 side, the layer closer to the anode side is sometimes called the hole injection layer 3. From the perspective of enhancing the function of transporting holes from the anode 2 side to the light-emitting layer 5 side, it is preferable to form the hole injection layer 3. When forming the hole injection layer 3, it is usually formed on the anode 2.

[0830] The thickness of the hole injection layer 3 is typically 1 nm or more, preferably 5 nm or more, and typically less than 1000 nm, preferably less than 500 nm.

[0831] The hole injection layer can be formed by vacuum evaporation or wet deposition. From the perspective of superior film formation properties, wet deposition is preferred.

[0832] The hole injection layer 3 preferably contains a hole-transporting compound, more preferably a hole-transporting compound and an electron-accepting compound. Furthermore, it is preferable that the hole injection layer contains a cationic radical compound, and particularly preferably a cationic radical compound and a hole-transporting compound.

[0833] The following describes a general method for forming a hole injection layer. In the organic light-emitting element of this embodiment, the hole injection layer is preferably formed using the above-described composition for organic light-emitting elements and by a wet film deposition method.

[0834] <Hole-transporting compounds>

[0835] The composition for forming the hole injection layer typically contains a hole-transporting compound that forms the hole injection layer 3. In the case of a wet film deposition method, the composition for forming the hole injection layer typically also further contains a solvent. 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 or use. Furthermore, excellent stability, low ionization potential, and high transparency to visible light are preferred. Especially when the hole injection layer 3 is in contact with the light-emitting layer 5, compounds that do not quench luminescence from the light-emitting layer 5, or that form excitation complexes with the light-emitting layer 5 without reducing luminescence efficiency, are preferred.

[0836] From the viewpoint of the charge injection barrier from the anode 2 to the hole injection layer 3, compounds with 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 formed by linking tertiary amines with fluorene groups, hydrazone compounds, silazane compounds, and quinacridone compounds.

[0837] Of the compounds illustrated above, aromatic amine compounds are preferred from the perspective of amorphousness and visible light transmittance, and aromatic tertiary amine compounds are particularly preferred. Aromatic tertiary amine compounds also include compounds having an aromatic tertiary amine structure, that is, compounds having groups derived from aromatic tertiary amines.

[0838] There are no particular restrictions on the types of aromatic tertiary amine compounds. From the perspective of easily obtaining uniform luminescence through surface smoothing effect, it is preferred to use polymeric compounds (polymeric compounds with linked repeating units) with a weight average molecular weight of 1,000 or more and 1,000,000 or less.

[0839] In the hole injection layer 3, in order to improve the conductivity of the hole injection layer by oxidation of the hole transport compound, it is preferable to contain the above-mentioned electron acceptor compound or the above-mentioned cationic radical compound.

[0840] Cationic radical compounds derived from polymers, such as PEDOT / PSS (Adv. Mater., 2000, Vol. 12, p. 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, Vol. 94, p. 7716), are also generated through oxidative polymerization (dehydrogenation polymerization).

[0841] The oxidative polymerization described here refers to the chemical or electrochemical oxidation of monomers in an acidic solution using peroxydisulfate or similar substances. In the case of this oxidative polymerization (dehydrogenation polymerization), the monomers are polymerized through oxidation, and cationic free radicals are generated, which use anions from the acidic solution as counter-anions and remove an electron from the repeating unit of the polymer.

[0842] <Formation of a Cavity Injection Layer Using a Wet Film Formation Method>

[0843] In the case of forming the hole injection layer 3 by wet film formation, a film-forming composition (a composition for forming the hole injection layer) is usually prepared by mixing the material that will become the hole injection layer 3 with a soluble solvent (a solvent for the hole injection layer), and the composition for forming the hole injection layer is coated on a layer (usually the anode 2) that corresponds to the lower layer of the hole injection layer 3, and then dried to form the film.

[0844] The concentration of the hole-transporting compound in the hole injection layer formation composition is arbitrary as long as it does not significantly impair the effects of the present invention, but a low concentration is preferred from the perspective of uniformity of film thickness, and a high concentration is preferred from the perspective of minimizing defects in the hole injection layer. Specifically, it is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, particularly preferably 0.5% by weight or more, and preferably 70% by weight or less, more preferably 60% by weight or less, and particularly preferably 50% by weight or less.

[0845] Examples of solvents include ether solvents, ester solvents, aromatic hydrocarbon solvents, and amide solvents.

[0846] 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.

[0847] Examples of ester solvents include phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate, and other aromatic esters.

[0848] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene.

[0849] Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide.

[0850] In addition to these, dimethyl sulfoxide, etc., can also be used.

[0851] The formation of the hole injection layer 3 using the wet film formation method is usually carried out by preparing a composition for forming the hole injection layer, coating it into a film on a layer (usually the anode 2) corresponding to the lower layer of the hole injection layer 3, and then drying it.

[0852] Hole injection layer 3 is usually dried after film formation by heating or depressurization drying.

[0853] <Formation of a hole injection layer using vacuum evaporation>

[0854] When forming the hole injection layer 3 by vacuum evaporation, 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 typically placed in a crucible placed inside a vacuum container (if two or more materials are used, they are typically placed in different crucibles). The vacuum container is then evacuated to 1000 ppm using a vacuum pump. -4 After heating to approximately 100 Pa, the crucible is heated (when using two or more materials, the crucibles are usually heated separately), and the evaporation rate of the materials inside the crucible is controlled while evaporating them (when using two or more materials, the evaporation rate is usually controlled independently while evaporating them), forming a hole injection layer 3 on the anode 2 on the substrate 1 facing the crucible. When using two or more materials, a mixture of them can also be placed in the crucible and heated to evaporate them to form a hole injection layer.

[0855] 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) or above and 9.0 × 10 -6 Torr(12.0×10 -4 The evaporation rate is not limited as long as it does not significantly impair the effect of the invention, and is typically [amount missing]. / second or more and / second or less. As long as it does not significantly impair the effect of the present invention, the film formation temperature during vapor deposition is not limited, but it is preferably performed at 10°C or higher and 50°C or lower.

[0856] Hole injection layer 3 can also be cross-linked with hole transport layer 4, which will be described later.

[0857] Hole transport layer

[0858] The hole transport layer 4 is a layer that performs the function of transporting holes from the anode 2 side to the light-emitting layer 5 side. In this embodiment, the hole transport layer 4 preferably contains the polymer of this embodiment as a material containing a portion of structure A. The hole transport layer 4 is generally formed between the anode 2 and the light-emitting layer 5. In the case where the hole injection layer 3 described above is present, the hole transport layer 4 is formed between the hole injection layer 3 and the light-emitting layer 5.

[0859] The thickness of the hole transport layer 4 is typically 5 nm or more, preferably 10 nm or more, and typically less than 300 nm, preferably less than 100 nm.

[0860] The hole transport layer 4 can be formed by vacuum evaporation or wet deposition. From the perspective of excellent film formation properties, it is preferred to form it by wet deposition.

[0861] The following describes a general method for forming a hole transport layer. In this embodiment, the hole transport layer is preferably formed using the aforementioned hole transport layer formation composition and a wet film deposition method.

[0862] Hole transport layer 4 typically contains a hole transport compound. Preferably, the hole transport compound contained in hole transport layer 4 is the polymer described in this embodiment, or a polymer formed by crosslinking the polymer if it has crosslinking groups. Furthermore, in addition to the polymer described above, it may also contain the hole transport compound described above, preferably aromatic diamines containing two or more tertiary amines and having two or more fused aromatic rings substituted on the nitrogen atom, 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., Vol. 72-74, p. 985, 1997), or aromatic amine compounds composed of tetramers of triphenylamine (Chemistry). Communications (Chem. Commun., 2175 pages, 1996), spiro compounds such as 2,2',7,7'-tetra-(diphenylamino)-9,9'-spirodifluorene (Synth. Metals, Vol. 91, 209 pages, 1997), carbazole derivatives such as 4,4'-N,N'-dicarbazole biphenyl, etc. Additionally, it may contain polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Application Laid-Open No. 7-53953), polyarylene ether sulfones containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, 33 pages, 1996), etc.

[0863] <Formation of Hole Transport Layer Using Wet Film Formation Method>

[0864] In the case of forming the hole transport layer 4 using a wet film deposition method, the hole transport layer forming composition is usually used instead of the hole injection layer forming composition, just as in the case of forming the hole injection layer 3 using a wet film deposition method described above.

[0865] When forming the hole transport layer 4 using a wet film deposition method, the composition for forming the hole transport layer typically further contains a solvent. The solvent used in the composition for forming the hole transport layer can be the same solvent used in the composition for forming the hole injection layer described above.

[0866] The concentration of the hole-transporting compound in the composition for forming the hole transport layer can be within the same range as the concentration of the hole-transporting compound in the composition for forming the hole injection layer.

[0867] The formation of the hole transport layer 4 using the wet film formation method can be carried out in the same way as the film formation method of the hole injection layer 3 described above.

[0868] <Formation of Hole Transport Layer Using Vacuum Evaporation>

[0869] In the case of forming the hole transport layer 4 using vacuum evaporation, the same material used to form the hole injection layer 3 can generally be used instead of the material used to form the hole transport layer 4, just as in the case of forming the hole injection layer 3 using vacuum evaporation. The film formation conditions, such as vacuum level, evaporation rate, and temperature, can be the same as those used for the vacuum evaporation of the hole injection layer 3.

[0870] [Emitting Layer]

[0871] The light-emitting layer 5 is a layer that performs the following function: when an electric field is applied between a pair of electrodes, it is excited by the recombination of holes injected from the anode 2 and electrons injected from the cathode 9, thereby emitting light. The light-emitting layer 5 is formed between the anode 2 and the cathode 9. The light-emitting layer 5 is formed between the hole transport layer 4 and the cathode 9.

[0872] The thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effect of the present invention, but a thicker layer is preferred from the perspective of minimizing defects in the film. On the other hand, a thinner layer is preferred from the perspective of easily forming a low driving voltage. Therefore, the thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and generally preferably 200 nm or less, more preferably 100 nm or less.

[0873] 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). The light-emitting layer of this embodiment preferably contains at least the low-molecular-weight compound of this embodiment as the light-emitting material and a material containing a portion of structure A.

[0874] The following describes a general method for forming a light-emitting material and a light-emitting layer. In the organic electroluminescent element of this embodiment, the light-emitting layer is preferably formed using the above-described light-emitting layer forming composition and by a wet film deposition method.

[0875] <Luminescent Materials>

[0876] There are no particular limitations as long as the luminescent material emits light at the desired wavelength without impairing 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, but a material with good luminescent efficiency is preferred. From the viewpoint of internal quantum efficiency, phosphorescent luminescent materials are preferred.

[0877] Examples of fluorescent materials include the following.

[0878] Examples of fluorescent materials that provide blue light emission include naphthalene, perylene, pyrene, anthracene, and coumarin. p-Bis(2-phenylvinyl)benzene and their derivatives, etc.

[0879] Examples of fluorescent materials that provide green light emission include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al(C9H6NO)3.

[0880] Examples of fluorescent materials that provide yellow light emission (yellow fluorescent materials) include rubrene and naphthyrimidine derivatives.

[0881] Examples of fluorescent materials that provide red emission (red fluorescent materials) include DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) series compounds, benzopyran derivatives, rhodamine derivatives, benzothioxan derivatives, and azabenzothioxan.

[0882] Examples of phosphorescent materials include organometallic complexes containing metals selected from groups 7 to 11 of the 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.

[0883] As ligands for organometallic complexes, preferred ligands are those formed by linking a heteroaryl group to pyridine, pyrazole, phenanthroline, etc., such as heteroarylpyridine ligands and heteroarylpyrazole ligands. Phenylpyridine ligands and phenylpyrazole ligands are particularly preferred. Here, heteroaryl refers to aryl or heteroaryl.

[0884] As preferred phosphorescent materials, examples include tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, tris(2-phenylpyridine)osmium, tris(2-phenylpyridine)rhenium and other phenylpyridine complexes, as well as porphyrin complexes such as octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, and octaphenylpalladium porphyrin.

[0885] 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 poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenyleneethylene], etc.

[0886] <Charge Transport Materials>

[0887] The charge transport material is a material that has the property of transporting positive charge (holes) or negative charge (electrons). There are no particular limitations on the charge transport material as long as it does not impair the effect of the present invention, and known charge transport materials can be used.

[0888] The charge transport material can be compounds that have been used in the light-emitting layer of organic electroluminescent elements, and compounds that are used as the host material of the light-emitting layer are particularly preferred.

[0889] As charge transport materials other than the low-molecular-weight compounds of this embodiment, examples 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, silaneamine compounds, phosphoamine compounds, and quinacridone compounds, which are examples of hole transport compounds used as hole injection layer materials. Furthermore, anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, phenanthroline compounds, etc., can be cited as examples. Diazole compounds, thiophene compounds, and other electron-transporting compounds.

[0890] Alternatively, aromatic diamines containing two or more tertiary amines and with two or more fused aromatic rings 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). Examples of compounds that serve as hole-transporting compounds in the hole transport layer include aromatic amine compounds composed of tetramers of triphenylamine (Chem. Commun., p. 2175, 1996), fluorene compounds such as 2,2',7,7'-tetra-(diphenylamino)-9,9'-spirodifluorene (Synth. Metals, Vol. 91, p. 209, 1997), and carbazole compounds such as 4,4'-N,N'-dicarbazole biphenyl.

[0891] Additionally, 2-(4-biphenyl)-5-(p-tert-butylphenyl)-1,3,4- diazole (tBu-PBD), 2,5-bis(1-naphthyl)-1,3,4- diazole (BND), etc. Diazole compounds; thiophene compounds such as 2,5-bis(6'-(2',2”-bipyridyl))-1,1-dimethyl-3,4-diphenylthiophene (PyPySPyPy); phenanthroline compounds such as bBPhen and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP).

[0892] <Formation of a light-emitting layer using a wet film-forming method>

[0893] The light-emitting layer 5 can be formed by vacuum evaporation or by wet deposition. From the perspective of excellent film formation properties, wet deposition is preferred, and spin coating and inkjet printing are further preferred. In particular, if the hole transport layer 4, which is the lower layer of the light-emitting layer 5, is formed using the aforementioned hole transport layer forming composition, it is easy to perform lamination using the wet deposition method; therefore, the wet deposition method is preferred. In the case of forming the light-emitting layer 5 by wet deposition, the aforementioned light-emitting layer forming composition is generally used instead of the hole injection layer forming composition, similar to the case of forming the aforementioned hole injection layer using the wet deposition method.

[0894] As a solvent removal method after wet film formation, heating or reduced pressure can be used. For the heating device used in the heating method, a cleaning oven or a heating plate is preferred from the perspective of providing heat evenly to the entire film.

[0895] The heating temperature in the heating process is arbitrary as long as it does not significantly impair the effects of the present invention. Higher temperatures are preferred for shortening drying time, while lower temperatures are preferred for minimizing damage to the material. The upper limit of the heating temperature is typically 250°C or lower, preferably 200°C or lower, and more preferably 150°C or lower. The lower limit of the heating temperature is typically 30°C or higher, preferably 50°C or higher, and more preferably 80°C or higher. Temperatures exceeding the above upper limits are less desirable because they may decompose or crystallize due to higher heat resistance than commonly used charge-transporting or phosphorescent materials. If the heating temperature is below the above lower limits, solvent removal requires a longer time, which is also undesirable. The heating time in the heating process can be appropriately determined based on the boiling point and vapor pressure of the solvent in the composition for forming the light-emitting layer, the heat resistance of the material, and the heating conditions.

[0896] <Formation of a light-emitting layer using vacuum evaporation>

[0897] When the light-emitting layer 5 is formed by vacuum evaporation, one or more of the constituent materials of the light-emitting layer 5 (the aforementioned light-emitting material, the low-molecular-weight compound of this embodiment, the charge-transporting compound, etc.) are typically placed in a crucible placed inside a vacuum container (if two or more materials are used, they are typically placed in different crucibles), and the vacuum container is evacuated to 1000 liters using a vacuum pump. -4After heating to approximately 100 Pa, the crucible is heated (when using two or more materials, the crucibles are usually heated separately), and the evaporation rate of the materials in the crucible is controlled while evaporating them (when using two or more materials, the evaporation rate is usually controlled independently while evaporating them), so that the light-emitting layer 5 is formed on the hole transport layer 4 placed facing the crucible. When using two or more materials, a mixture of them can also be placed in the crucible and heated to evaporate them to form the light-emitting layer 5.

[0898] 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) or above and 9.0 × 10 -6 Torr(12.0×10 -4 The evaporation rate is not limited as long as it does not significantly impair the effect of the invention, and is typically [amount missing]. / second or more and / second or less. As long as it does not significantly impair the effect of the present invention, the film formation temperature during vapor deposition is not limited, but it is preferably performed at 10°C or higher and 50°C or lower.

[0899] [Cavity barrier]

[0900] A hole blocking layer 6 may also be provided 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.

[0901] The hole blocking layer 6 serves to block holes moving from the anode 2 from reaching the cathode 9 and to efficiently transport electrons injected from the cathode 9 to the light-emitting layer 5. The required physical properties of the material constituting the hole blocking layer 6 include high electron mobility and low hole mobility, a large bandgap (difference between HOMO and LUMO), and a high excited triplet energy level (T1).

[0902] Examples of materials that satisfy such conditions for the hole-blocking layer 6 include, for instance, mixed ligand complexes such as bis(2-methyl-8-hydroxyquinoline)(phenol)aluminum and bis(2-methyl-8-hydroxyquinoline)(triphenylsilanol)aluminum, metal complexes such as bis(2-methyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2-methyl-8-quinoline)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 phenanthrene 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, and 6, as described in International Publication No. 2005 / 022962, are also preferred as materials for the hole blocking layer 6.

[0903] 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.

[0904] The thickness of the hole blocking layer 6 is arbitrary as long as it does not significantly impair the effect of the present invention, but 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.

[0905] [Electron transport layer]

[0906] The electron transport layer 7 is disposed between the light-emitting layer 5 and the electron injection layer 8 for the purpose of further improving the current efficiency of the device.

[0907] The electron transport layer 7 is formed of a compound capable of efficiently transporting electrons injected from the cathode 9 to the light-emitting layer 5 between electrodes subjected to an electric field. The electron transport compound used in the electron transport layer 7 needs to be a compound with high electron injection efficiency from the cathode 9 or the electron injection layer 8 and high electron mobility, capable of efficiently transporting the injected electrons.

[0908] 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, thiophene 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), 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.

[0909] 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.

[0910] The electron transport layer 7 is formed on the hole blocking layer 6 by laminating it using a wet film deposition method or a vacuum evaporation method, as described above. Vacuum evaporation is typically used.

[0911] [Electron Injection Layer]

[0912] The electron injection layer 8 performs the following function: efficiently injecting electrons injected from the cathode 9 into the electron transport layer 7 or the light-emitting layer 5.

[0913] 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 or cesium, and alkaline earth metals such as barium or calcium. In this case, the thickness of the electron injection layer 8 is typically preferred to be 0.1 nm or more and 5 nm or less.

[0914] As the material for forming the electron injection layer 8, doping organic electron transport materials with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (as described in Japanese Patent Application Publication No. 10-270171, 2002-100478, and 2002-100482, etc.) can achieve both improved electron injection and transport properties, and is therefore preferred.

[0915] In this case, 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.

[0916] The electron injection layer 8 is formed by laminating the light-emitting layer 5 or the hole blocking layer 6 or the electron transport layer 7 on it using a wet film deposition method or a vacuum evaporation method.

[0917] The details of the wet film formation method are the same as those of the light-emitting layer described above.

[0918] [cathode]

[0919] The cathode 9 functions as a layer that injects electrons into the side of the light-emitting layer 5 (electron injection layer 8 or light-emitting layer 5, etc.).

[0920] The cathode 9 can be made of the same material used in the anode 2 described above. From the perspective of efficient electron injection, a metal with a low work function is preferred, such as tin, magnesium, indium, calcium, aluminum, silver, or alloys thereof. Specific examples include alloy electrodes with low work functions such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0921] From the perspective of component stability, it is preferable to stack a metal layer with a high work function and relative stability to the atmosphere on the cathode 9 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.

[0922] The film thickness of cathode 9 is usually the same as that of anode 2.

[0923] [Other layers]

[0924] Provided that the effect of the present invention is not significantly impaired, the organic electroluminescent element of this embodiment may further have other layers. That is, any other layer mentioned above may also be present between the anode 2 and the cathode 9.

[0925] [Other components]

[0926] The organic electroluminescent element of this embodiment can also have a structure opposite to that described above, i.e., the cathode 9, electron injection layer 8, electron transport layer 7, hole blocking layer 6, light-emitting layer 5, hole transport layer 4, hole injection layer 3, and anode 2 are stacked on the substrate 1 in that order. Alternatively, the organic electroluminescent element of the present invention can be disposed between at least two substrates with high transparency.

[0927] When the organic electroluminescent element of this embodiment is applied to an organic electroluminescent device, it can be used as a single organic electroluminescent element, or it can be configured to have multiple organic electroluminescent elements arranged in an array, or it can be configured to have the anode and cathode arranged in an XY matrix.

[0928] [Organic EL display device]

[0929] The organic EL display device (organic electroluminescent element display device) of this embodiment uses the above-described organic electroluminescent element. There are no particular limitations on the model or structure of the organic EL display device of this embodiment; the above-described organic electroluminescent element can be used and assembled according to conventional methods.

[0930] For example, the organic EL display device of the present invention can be formed by such a method as described in "Organic EL Display" (Ohm Corporation, published on August 20, 2004, written by Shizushi Tokito, Chinatsuya Adachi, and Hideyuki Murata).

[0931] [Organic EL Lighting]

[0932] The organic EL lighting (organic electroluminescent element lighting) of this embodiment uses the above-described organic electroluminescent element. There are no particular limitations on the model or structure of the organic EL lighting of this embodiment; the above-described organic electroluminescent element can be used and assembled according to common methods.

[0933] Example

[0934] The following embodiments further illustrate the present invention in detail. The present invention is not limited to the following embodiments; any modifications can be made to implement the invention without departing from its spirit.

[0935] [Synthetic Example 1: Synthesis of a polymer compound possessing part of structure A]

[0936] <Synthesis of raw material monomers>

[0937]

[0938] Under a nitrogen stream, 3-bromo-3'-nitro-biphenyl (14.1 g, 50.5 mmol), bis(pinacol)diboron (17.1 g, 60.6 mmol), and potassium acetate (24.8 g, 253.0 mmol) were placed in a 1000 ml flask, and nitrogen replacement was performed at room temperature. Subsequently, 200 ml of 1,4-dioxane was added. Alkane was added to 1,1'-bis(diphenylphosphino)ferrocene-palladium(II)-dichloromethane [PdCl2(dppf)CH2Cl2] (1.24 g, 1.52 mmol), and the reaction was carried out at 100 °C for 8.5 hours.

[0939] The reaction solution was filtered under reduced pressure, diluted with toluene, and crudely purified using activated clay. The crude product was then purified by column chromatography (developing solvent: hexane / ethyl acetate = 80 / 20) to obtain compound 1 (16.3 g, yield 99.5%).

[0940]

[0941] Next, compound 1 (8.7 g, 26.76 mmol), 1-bromo-3-iodobenzene (7.95 g, 28.1 mmol), potassium phosphate aqueous solution (2 M, 40.1 ml), toluene (80 ml), and ethanol (40 ml) were placed into a flask, and the system was thoroughly nitrogen-replaced and heated to 65 °C.

[0942] Bis(triphenylphosphine)palladium(II) dichloride (0.094 g, 0.134 mmol) was added to the mixture, and the mixture was stirred at 65 °C for 3 hours. Water was added to the reaction mixture, and extraction was performed using toluene. The organic layer was dried using anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was further purified by column chromatography (developing solvent: hexane / dichloromethane = 80 / 20) to give compound 2 (8.6 g, yield 90.5%).

[0943]

[0944] Under a nitrogen atmosphere, 100 ml of dimethyl sulfoxide, compound 2 (8.55 g, 24.14 mmol), bis(pinacol)diboron (7.36 g, 28.97 mmol), and potassium acetate (7.1 g, 72.42 mmol) were placed in a 300 ml flask and stirred at 60 °C for 30 minutes. Subsequently, 0.99 g, 1.21 mmol of 1,1'-bis(diphenylphosphino)ferrocene-palladium(II)-dichloromethane [PdCl2(dppf)CH2Cl2] was added, and the reaction was carried out at 85 °C for 4.0 hours.

[0945] The reaction solution was filtered under reduced pressure, the filtrate was extracted with toluene, dried with anhydrous magnesium sulfate, and crudely purified using activated clay. The crude product was then purified by column chromatography (developing solvent: hexane / ethyl acetate = 90 / 10) to obtain compound 3 (9.3 g, yield 96.0%).

[0946]

[0947] Next, compound 3 (9.3 g, 23.18 mmol), 1-bromo-4-iodobenzene (6.88 g, 24.33 mmol), potassium phosphate aqueous solution (2 M, 34.8 ml), toluene (80 ml), and ethanol (40 ml) were placed into a flask, and the system was thoroughly nitrogen-replaced and heated to 65 °C.

[0948] Bis(triphenylphosphine)palladium(II) dichloride (0.081 g, 0.116 mmol) was added, and the mixture was stirred at 65 °C for 3.5 h. Water was added to the reaction mixture, and extraction was performed using toluene. The organic layer was dried with anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was purified by column chromatography (developing solvent: hexane / dichloromethane = 75 / 25) to give compound 4 (8.7 g, yield 87.2%).

[0949]

[0950] Under a nitrogen atmosphere, 100 ml of dimethyl sulfoxide, compound 4 (8.7 g, 20.22 mmol), bis(pinacol)diboron (6.2 g, 24.26 mmol), and potassium acetate (5.95 g, 60.66 mmol) were placed in a 300 ml flask and stirred at 60 °C for 30 minutes. Subsequently, 1,1'-bis(diphenylphosphino)ferrocene-palladium(II)-dichloromethane [PdCl2(dppf)CH2Cl2] (0.83 g, 1.01 mmol) was added, and the reaction was carried out at 85 °C for 3.0 hours.

[0951] The reaction solution was filtered under reduced pressure, the filtrate was extracted with toluene, dried with anhydrous magnesium sulfate, and purified with activated clay. The crude product was then purified by column chromatography (developing solvent: hexane / dichloromethane = 50 / 50) to obtain compound 5 (7.2 g, yield 75.0%).

[0952]

[0953] Next, compound 5 (7.1 g, 14.87 mmol), commercially available 2-chloro-4,6-diphenyl-1,3,5-triazine (3.98 g, 14.87 mmol), potassium phosphate aqueous solution (2 M, 23.0 ml), toluene (50 ml), and ethanol (25 ml) were placed into a flask, and the system was thoroughly nitrogen-replaced and heated to 65 °C.

[0954] Tetra(triphenylphosphine)palladium(0) (0.52 g, 0.45 mmol) was added, and the mixture was stirred at 85 °C for 4.0 h. The precipitated insoluble matter was filtered under reduced pressure, and the filtrate was washed with 50 mL of dichloromethane and added dropwise to 200 mL of ethanol. The precipitate was filtered under reduced pressure and dried to give compound 6 (5.3 g, yield 61.2%).

[0955]

[0956] Under a nitrogen atmosphere, 500 ml of tetrahydrofuran, 50 ml of ethanol, compound 6 (5.3 g, 9.10 mmol), and palladium / carbon (10%, approximately 55% aqueous wet product, 0.72 g) were placed in a 1000 ml flask and stirred at 50 °C for 15 minutes. Subsequently, hydrazine monohydrate (3.1 g) was added dropwise, and the reaction was continued at this temperature for 3 hours.

[0957] The reaction solution was filtered under reduced pressure using water-moistened diatomaceous earth, and the filtrate was concentrated to obtain compound 7 (4.8 g, yield 95.1%).

[0958]

[0959] In a 500 mL flask, compound 8 (8.0 g, 49 mmol), 1-bromo-1'-iodo-3,3'-biphenyl (17.7 g, 49 mmol), 120 mL of toluene, 60 mL of ethanol, and 62 mL of 2 M potassium phosphate aqueous solution were placed and bubbled under nitrogen for 30 minutes. Tetra(triphenylphosphine)palladium(0) (1.43 g, 1.24 mmol) was added, and the mixture was heated and stirred at 90 °C for 3 hours. Afterward, the mixture was cooled to room temperature, washed separately with water and toluene, and the organic layer was dried over anhydrous magnesium sulfate. The solvent was then removed under reduced pressure. The residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 9) to give 15.5 g of compound 9 as a colorless oil.

[0960]

[0961] In a 500 mL flask, compound 9 (15.5 g, 44 mmol), 3-aminophenylboronic acid monohydrate (6.4 g, 41 mmol), 100 mL toluene, 50 mL ethanol, and 55 mL of 2 M potassium phosphate aqueous solution were placed and subjected to nitrogen bubbling for 30 minutes. Tetra(triphenylphosphine)palladium(0) (1.3 g, 1.15 mmol) was added, and the mixture was heated and stirred at 90 °C for 3.5 h. Afterward, the mixture was cooled to room temperature, washed with water and toluene, and the organic layer was dried over anhydrous magnesium sulfate. The solvent was then removed under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate / hexane = 2 / 8) to give 7.8 g of compound 10 as a pale yellow syrup.

[0962]

[0963] A solution containing 270 ml of toluene, 135 ml of ethanol, 20.0 g (44.8 mmol) of compound 11, 50.72 g (179.3 mmol) of 5-bromo-2-iodotoluene, and 191 ml of 2M potassium phosphate aqueous solution was placed in a 1 L flask and degassed under vacuum, followed by nitrogen replacement. The mixture was heated and stirred for 30 minutes under a nitrogen stream. Then, 0.63 g (0.90 mmol) of bis(triphenylphosphine)palladium(II) dichloride was added, and the mixture was refluxed for 6 hours. Water was added to the reaction solution, and extraction was performed using toluene, followed by treatment with anhydrous magnesium sulfate and activated clay. The toluene solution was refluxed, the insoluble matter was filtered, and recrystallization yielded a colorless solid of compound 12 (yield 14.2 g, 60.2%).

[0964]

[0965] Compound 14 was synthesized by the same method as that used for the synthesis of compound 12, except that 1-bromo-4-iodobenzene was used instead of 5-bromo-2-iodotoluene.

[0966] <Synthesis of a polymer (polymer 1) with partial structure A>

[0967]

[0968] Compound 12 (2.5 g, 4.7 mmol), compound 13 (2.134 g, 6.1 mmol), compound 10 (0.51 g, 1.4 mmol), compound 7 (1.04 g, 1.9 mmol), sodium tert-butoxide (3.48 g, 36.2 mmol), and toluene (71 ml) were added to the system. The system was then thoroughly nitrogen-replaced and heated to 60 °C (solution A1).

[0969] Additionally, [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (199.4 mg, 0.8 mmol) was added to a 14 ml toluene solution of tris(dibenzylacetone)palladium complex (86.0 mg, 0.09 mmol) and heated to 60 °C (solution B1).

[0970] 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 compounds 7, 10, and 13, compound 14 (1.78 g, 3.5 mmol) was added. After heating under reflux for 2 hours, bromobenzene (1.84 g, 11.7 mmol) was added, and the mixture was heated under reflux for 1 hour. The reaction mixture was cooled and added dropwise to an ethanol / water (370 ml / 70 ml) solution to obtain the end-capped crude polymer.

[0971] The end-capped crude polymer was dissolved in toluene and then precipitated in acetone. The precipitated polymer was filtered off. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and then reprecipitated using ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain polymer 1 (2.5 g) as the target analyte. The molecular weight and other properties of the obtained polymer 1 are as follows.

[0972] Weight-average molecular weight (Mw) = 20600

[0973] Number average molecular weight (Mn) = 15260

[0974] Dispersion (Mw / Mn) = 1.35

[0975] [Example 1]

[0976] Organic electroluminescent elements are fabricated using the following method.

[0977] A glass substrate (manufactured by Sanrong Vacuum Corporation, sputtered) with a 70nm thick transparent conductive film of indium tin oxide (ITO) was deposited on it. The substrate was then patterned with 2mm wide stripes using conventional photolithography and hydrochloric acid etching to form the anode. The substrate, thus patterned with ITO, was then cleaned in the following sequence: ultrasonic cleaning with a surfactant aqueous solution, rinsing with ultrapure water, ultrasonic cleaning with ultrapure water, and rinsing with ultrapure water. Afterward, it was dried with compressed air and finally subjected to ultraviolet ozone cleaning.

[0978] As a composition for forming a hole injection layer, 100 parts by weight of a hole-transporting polymeric compound having a repeating structure as shown in formula (P-1) and 20 parts by weight of a compound as shown in formula (HI-1) are weighed and dissolved in ethyl benzoate to prepare a composition with a solid content concentration of 3.0% by weight.

[0979]

[0980] The hole injection layer forming composition was spin-coated onto the substrate in the atmosphere and dried in the atmosphere at 240°C for 30 minutes using a heating plate to form a uniform thin film with a thickness of 40 nm, thus forming a hole injection layer.

[0981] Next, 100 parts by weight of the charge transport polymer compound of the following formula (HT-1) synthesized in Synthesis Example 1 were dissolved in cyclohexylbenzene to prepare a hole transport layer forming composition consisting of a 3.0% by weight solution.

[0982] The hole transport layer forming composition was spin-coated onto a substrate with the hole injection layer coated in the above-mentioned film in a nitrogen glove box. The substrate was then dried at 230°C for 30 minutes using a heating plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm, thus forming the hole transport layer.

[0983]

[0984] Next, 15 parts by weight of the compound shown in formula (H-1), 15 parts by weight of the compound shown in formula (H-2), 70 parts by weight of the compound shown in formula (H-3), and 20 parts by weight of the compound shown in formula (D-1) as materials for the light-emitting layer are weighed and dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 7.8% by weight as a composition for forming the light-emitting layer.

[0985]

[0986] The composition for forming the light-emitting layer is spin-coated onto a substrate coated with the hole transport layer in a nitrogen glove box. The substrate is then dried at 120°C for 20 minutes using a heating plate in the nitrogen glove box to form a uniform thin film with a thickness of 70 nm, thus forming the light-emitting layer.

[0987] 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.

[0988] Next, the compound shown in formula (HB-1) and lithium 8-hydroxyquinoline were deposited on the light-emitting layer at a film thickness ratio of 2:3 using a vacuum evaporation method. Co-evaporation was performed at a rate of / second to form a hole blocking layer with a thickness of 30 nm.

[0989]

[0990] Next, a 2mm wide striped shadow mask, which serves as a mask for cathode evaporation, is fitted onto the substrate in a manner orthogonal to the ITO stripes of the anode, and placed in another vacuum evaporation apparatus.

[0991] Furthermore, as the cathode, a molybdenum boat is used to heat the aluminum at a vapor deposition rate. / second~ A cathode is formed by creating an aluminum layer with a thickness of 80 nm per second.

[0992] An organic electroluminescent element with a light-emitting area of ​​2mm × 2mm is obtained in the manner described above.

[0993] [Comparative Example 1]

[0994] Except for changing the material composition of the light-emitting layer to a weight ratio of (H-4):(H-5):(H-3):(D-1) = 15:15:70:20, the organic electroluminescent element was fabricated in the same manner as in Example 1. (H-4) and (H-5) are represented by the following formula.

[0995]

[0996] [Component Evaluation]

[0997] The application of 10 mA / cm² to the organic electroluminescent elements obtained in Example 1 and Comparative Example 1 was measured. 2 The voltage at which the current is measured is the relative voltage obtained by subtracting the voltage of Comparative Example 1 from the voltage of Example 1. Furthermore, the luminous efficacy (cd / A) at this time is measured, and the relative luminous efficacy of Example 1 when the luminous efficacy of Comparative Example 1 is set to 1 is taken as the relative luminous efficacy.

[0998] Additionally, at 40mA / cm 2 These organic electroluminescent elements were driven, and the 15% luminance decay lifetime (LT85) was measured to determine the ratio when the 15% decay lifetime of Comparative Example 1 was 1 (hereinafter referred to as "relative decay lifetime").

[0999] They are shown in Table 1.

[1000] As shown in Table 1, the organic electroluminescent element of the present invention, which contains compounds having the same partial structure A, i.e., the structure shown in formula (TzP), in the hole transport layer and the light emission layer, achieves low voltage and long lifetime.

[1001] Here, the charge transport polymer compound represented by formula (HT-1) used in Example 1 and the compound represented by formula (H-1) both have a structure consisting of four benzene rings linked to triazine, thus exhibiting high commonality, which is believed to contribute to long lifetime.

[1002] [Table 1]

[1003]

[1004] [Example 2]

[1005] Organic electroluminescent elements are fabricated using the following method.

[1006] A glass substrate (manufactured by Geomatec, sputtered) with a 50 nm thick transparent conductive film of indium tin oxide (ITO) was deposited on it. This substrate was then patterned with 2 mm wide stripes using conventional photolithography and hydrochloric acid etching to form the anode. The ITO-patterned substrate was then cleaned in the following sequence: ultrasonic cleaning with a surfactant aqueous solution, rinsing with ultrapure water, ultrasonic cleaning with ultrapure water, and rinsing with ultrapure water again. After drying with compressed air, it was finally subjected to ultraviolet ozone cleaning.

[1007] As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0 wt% of the hole-transporting polymer compound having the repeating structure shown in Formula (P-1) and 0.6 wt% of the compound shown in Formula (HI-1) used in Example 1 in ethyl benzoate.

[1008] The above-mentioned hole injection layer forming composition is spin-coated onto the above-mentioned substrate in the atmosphere, and dried in the atmosphere at 240°C for 30 minutes using a heating plate to form a uniform thin film with a thickness of 40 nm, thus forming a hole injection layer.

[1009] Next, 100 parts by weight of the charge-transporting polymer compound of the following formula (HT-2), which is used as a hole transport layer material, are dissolved in cyclohexylbenzene to prepare a hole transport layer forming composition consisting of a 3.0% by weight solution.

[1010] The above-mentioned hole transport layer forming composition is spin-coated onto a substrate coated with the above-mentioned hole injection layer in a nitrogen glove box. The substrate is then dried at 230°C for 30 minutes using a heating plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm, thus forming a hole transport layer.

[1011]

[1012] Next, 50 parts by weight of the compound shown in formula (H-1) above, 50 parts by weight of the compound shown in formula (H-6) below, and 15 parts by weight of the compound shown in formula (D-1) above, used as materials for the light-emitting layer, were weighed and dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming the light-emitting layer.

[1013]

[1014] The above-mentioned light-emitting layer forming composition is spin-coated onto a substrate coated with the above-mentioned hole transport layer in a nitrogen glove box. The substrate is then dried at 120°C for 20 minutes using a heating plate in the nitrogen glove box to form a uniform thin film with a thickness of 80 nm, thus forming the light-emitting layer.

[1015] 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.

[1016] Next, the compound shown in formula (ET-1) and lithium 8-hydroxyquinoline were deposited on the light-emitting layer at a film thickness ratio of 2:3 using a vacuum evaporation method. Co-evaporation was performed at a rate of / second to form a hole blocking layer with a thickness of 30 nm.

[1017]

[1018] Next, a 2mm wide striped shadow mask, which serves as a mask for cathode evaporation, is fitted onto the substrate in a manner orthogonal to the ITO stripes of the anode, and placed in another vacuum evaporation apparatus.

[1019] Furthermore, as the cathode, a molybdenum boat is used to heat the aluminum at a vapor deposition rate. / second~ A cathode is formed by creating an aluminum layer with a thickness of 80 nm per second.

[1020] An organic electroluminescent element with a light-emitting area of ​​2mm × 2mm is obtained in the manner described above.

[1021] [Comparative Example 2]

[1022] Except for changing the material composition of the light-emitting layer to a weight ratio of (H-4):(H-6):(D-1) = 50:50:15, the organic electroluminescent element was fabricated in the same manner as in Example 1. (H-4) is the substance shown in Comparative Example 1 above.

[1023] [Component Evaluation]

[1024] When the organic electroluminescent elements obtained in Example 2 and Comparative Example 2 are energized, the result is obtained at 1000 cd / m². 2 The voltage and external quantum efficiency (EQE(%)) of the light emitted.

[1025] The value obtained by subtracting the voltage of Comparative Example 2 from the voltage of Example 2 is recorded as the relative voltage in Table 2.

[1026] The EQE of Example 2 when the EQE of Comparative Example 2 is set to 1 is recorded as the relative EQE in Table 2.

[1027] In addition, the drive life of the component is evaluated using 60 mA / cm². 2 The current density was continuously applied to the element, and the time (LT90 (hr)) until the brightness of the element decreased to 90% of the initial brightness was measured. The lifetime of LT90 of Example 2 when the LT90 of Comparative Example 2 was 1 was recorded as the relative lifetime in Table 2.

[1028] As shown in Table 2, the organic electroluminescent element of the present invention, which contains compounds having the same partial structure A, i.e., the structure shown in formula (TzP), in the hole transport layer and the light emission layer, achieves low voltage and long lifetime.

[1029] [Table 2]

[1030]

[1031] [Example 3]

[1032] Weigh 50 parts by weight of the compound shown in formula (H-7), 50 parts by weight of the compound shown in formula (H-8), and 15 parts by weight of the compound shown in formula (D-1) as materials for the light-emitting layer, dissolve them in cyclohexylbenzene, and prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming the light-emitting layer. Otherwise, the element is made in the same manner as in Example 2.

[1033]

[1034] [Example 4]

[1035] Weigh 50 parts by weight of the compound shown in formula (H-1), 50 parts by weight of the compound shown in formula (H-8), and 15 parts by weight of the compound shown in formula (D-1) as materials for the light-emitting layer, dissolve them in cyclohexylbenzene, and prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming the light-emitting layer. Otherwise, the element is made in the same manner as in Example 2.

[1036] [Comparative Example 3]

[1037] Weigh 50 parts by weight of the compound shown in formula (H-4), 50 parts by weight of the compound shown in formula (H-8), and 15 parts by weight of the compound shown in formula (D-1) as materials for the light-emitting layer, dissolve them in cyclohexylbenzene, and prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming the light-emitting layer. Otherwise, the element is made in the same manner as in Example 2.

[1038] [Comparative Example 4]

[1039] Except that the charge transport polymer compound shown in formula (HT-3) is used instead of the charge transport polymer compound shown in formula (HT-2) as the hole transport layer material, the element is fabricated in the same manner as in Comparative Example 3.

[1040]

[1041] [Component Evaluation]

[1042] When the organic electroluminescent elements obtained in Examples 3 and 4 and Comparative Examples 3 and 4 are energized, the result is obtained at 1000 cd / m². 2 The voltage and external quantum efficiency (EQE(%)) of the light emitted.

[1043] The relative voltages are recorded in Table 3 by subtracting the voltage of Comparative Example 4 from the voltages of Examples 3, 4, and 3.

[1044] The relative EQEs of Example 3, Example 4 and Comparative Example 3 when the EQE of Comparative Example 4 is 1 are recorded in Table 3.

[1045] In addition, the drive life of the component is evaluated using 60 mA / cm². 2 The current density was continuously applied to the element, and the time (LT95 (hr)) until the brightness of the element decreased to 95% of the initial brightness was measured. The lifetimes of LT95 of Example 3, Example 4 and Comparative Example 3 when LT95 of Comparative Example 4 was 1 are recorded as relative lifetimes in Table 3.

[1046] As shown in Table 3, the organic electroluminescent element of the present invention, which contains compounds having the same partial structure A, i.e., the structure shown in formula (TzP), in the hole transport layer and the light emission layer, achieves low voltage and long lifetime.

[1047] [Table 3]

[1048]

[1049] [Example 5]

[1050] Weigh 50 parts by weight of the compound shown in formula (H-9), 50 parts by weight of the compound shown in formula (H-6), and 15 parts by weight of the compound shown in formula (D-2) as materials for the light-emitting layer, dissolve them in cyclohexylbenzene, and prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming the light-emitting layer. Otherwise, the element is made in the same manner as in Example 3.

[1051]

[1052] [Comparative Example 5]

[1053] The charge transport polymer compound shown in formula (HT-3) above is used instead of the charge transport polymer compound shown in formula (HT-2) above as the hole transport layer material; and 50 parts by weight of the compound shown in formula (H-9), 50 parts by weight of the compound shown in formula (H-6) above, and 15 parts by weight of the compound shown in formula (D-3) below are weighed as the material of the light-emitting layer, and dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as the composition for forming the light-emitting layer. Otherwise, the element is made in the same manner as in Example 4.

[1054]

[1055] [Component Evaluation]

[1056] When the organic electroluminescent elements obtained in Example 5 and Comparative Example 5 are energized, the result is determined at 1000 cd / m². 2 The voltage and external quantum efficiency (EQE(%)) of the light emitted.

[1057] The value obtained by subtracting the voltage of Comparative Example 5 from the voltage of Example 5 is recorded as the relative voltage in Table 4.

[1058] The EQE of Example 5 when the EQE of Comparative Example 5 is 1 is recorded as the relative EQE in Table 4.

[1059] In addition, the drive life of the component is evaluated using 60 mA / cm². 2 The current density was continuously applied to the element, and the time (LT95 (hr)) until the brightness of the element decreased to 95% of the initial brightness was measured. The lifetime of LT95 of Example 5 when the LT95 of Comparative Example 5 was 1 was recorded as the relative lifetime in Table 4.

[1060] As shown in Table 4, the organic electroluminescent element of the present invention, which contains compounds having the same partial structure A, i.e., the structure shown in formula (TzP), in the hole transport layer and the light emission layer, achieves low voltage and long lifetime.

[1061] [Table 4]

[1062]

[1063] [Example 6]

[1064] The charge transport polymer compound shown in formula (HT-4) is used instead of the charge transport polymer compound shown in formula (HT-2) as the hole transport layer material; and 50 parts by weight of the compound shown in formula (H-10), 25 parts by weight of the compound shown in formula (H-11), 25 parts by weight of the compound shown in formula (H-12) and 30 parts by weight of the compound shown in formula (D-4) are weighed as the material of the light-emitting layer, and dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as the composition for forming the light-emitting layer. Otherwise, the element is fabricated in the same manner as in Example 2.

[1065]

[1066] [Comparative Example 6]

[1067] The element was fabricated in the same manner as in Example 6, except that the charge transport polymer compound shown in Formula (HT-3) was used instead of the charge transport polymer compound shown in Formula (HT-4) as the hole transport layer material.

[1068] [Component Evaluation]

[1069] When the organic electroluminescent elements obtained in Example 6 and Comparative Example 6 are energized, the result is obtained at 1000 cd / m². 2 The external quantum efficiency (EQE (%)) during luminescence is shown. The EQE of Example 6 when the EQE of Comparative Example 6 is set to 1 is recorded as the relative EQE in Table 5.

[1070] In addition, the drive life of the component is evaluated using 15 mA / cm². 2 The current density was continuously applied to the element, and the time (LT90 (hr)) until the brightness of the element decreased to 90% of the initial brightness was measured. The lifetime of LT90 of Example 6 when the LT90 of Comparative Example 6 was 1 was recorded as the relative lifetime in Table 5.

[1071] As shown in Table 5, the organic electroluminescent element of the present invention, which contains compounds having the same partial structure A in the hole transport layer and the light emission layer, achieves low voltage and long lifetime.

[1072] [Table 5]

[1073]

[1074] The invention has been described in detail using specific methods, but it will be apparent to those skilled in the art that various modifications can be made without departing from the intent and scope of the invention.

[1075] This application is based on Japanese Patent Application 2020-027324, filed on February 20, 2020, the entire contents of which are incorporated herein by reference.

[1076] Symbol Explanation

[1077] 1 substrate

[1078] 2 Anode

[1079] 3. Hole injection layer

[1080] 4. Hole transport layer

[1081] 5. Light-emitting layer

[1082] 6. Cavity barrier layer

[1083] 7. Electron Transport Layer

[1084] 8 Electron Injection Layer

[1085] 9 Cathode

[1086] 10 Organic electroluminescent elements

Claims

1. An organic electroluminescent device having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate. The organic layer has a hole transport layer and a light-emitting layer adjacent to the hole transport layer. At least one material contained in the hole transport layer and at least one material contained in the light-emitting layer have the same partial structure A as shown in the following formula (31). The partial structure A shown in equation (31) is the structure shown in equation (35) below. The light-emitting layer comprises a low-molecular-weight compound having the partial structure A, wherein the low-molecular-weight compound is a compound with a molecular weight of less than 5000 as shown in any of the following formulas (10A-1) to (10A-3). ， In equation (31), Cyclic HA represents an aromatic heterocycle with 3 or more but less than 60 carbon atoms, consisting of a monocyclic ring or 2 to 6 fused rings, and may have substituents. The benzene ring in formula (31) can have substituents. Ar 0 This refers to an aromatic hydrocarbon group having 6 or more but less than 60 carbon atoms that may have substituents, an aromatic heterocyclic group having 3 or more but less than 60 carbon atoms that may have substituents, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups having 6 or more but less than 60 carbon atoms that may have substituents and aromatic heterocyclic groups having 3 or more but less than 60 carbon atoms that may have substituents. n1 represents 0 or Ar on ring HA. 0 Integers less than the number of substitutions. When n1 is 2 or more, multiple Ar 0 They can be the same or different. The substituent is selected from the group Z of substituents below. ， In equation (35), Ar 0 n1 and Ar in equation (31) 0 The meanings of n1 and n2 are the same. The benzene ring in formula (35) can also have substituents. X and Y can each independently represent a C atom or a N atom. When X and Y are C atoms, Ar 0 Bonding can be performed. The substituent is selected from the group Z of substituents below. ， In equations (10A-1) to (10A-3), Xa 1 Ya 1 and Za 1 Each can independently represent a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or a divalent aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents. Xa 2 Ya 2 and Za 2 Each can independently represent a hydrogen atom, an aromatic hydrocarbon group with 6 to 30 carbon atoms that may have substituents, or an aromatic heterocyclic group with 3 to 30 carbon atoms that may have substituents. R 33 Represents a hydrogen atom or substituent, multiple R 33 They can be the same or different. Xa 1 Ya 1 Za 1 Xa 2 Ya 2 and Za 2 Possible substituents and R when used as a substituent 33 The substituents listed in substituent group Z below or the crosslinking groups listed in crosslinking group K below are examples of substituents. g11', h11', and j11' each independently represent integers from 0 to 5. When g11', h11', and j11' are 2 or more, multiple Xa 1 Ya 1 Za 1 They can be the same or different. [Substituted basis set Z] Alkyl groups that are straight-chain, branched, or cyclic and have 1 or more but less than 24 carbon atoms; Alkenes with 2 or more but less than 24 carbon atoms; Alkyne groups with 2 or more but less than 24 carbon atoms; Alkoxy groups having 1 or more but less than 24 carbon atoms; Aryloxy or heteroaryloxy groups having 4 or more carbon atoms and 24 carbon atoms; Alkoxycarbonyl group with 2 or more but less than 24 carbon atoms; Dialkylamino groups with 2 or more but less than 24 carbon atoms; Diarylamino groups with 10 or more but less than 36 carbon atoms; Arylalkylamino groups with 7 or more but less than 36 carbon atoms; Acyl groups with 2 or more but less than 24 carbon atoms; Halogen atom; Alkyl halogenates having 1 or more but less than 12 carbon atoms; Alkylthio groups with 1 or more but less than 24 carbon atoms; Arylthio or heteroarylthio groups with 4 or more but less than 36 carbon atoms; silane groups having 2 or more but less than 36 carbon atoms; Silyloxy groups with 2 or more but less than 36 carbon atoms; Cyano; Aromatic hydrocarbon groups with 6 or more but less than 36 carbon atoms; Aromatic heterocyclic groups with 3 or more but less than 36 carbon atoms; A monovalent aromatic group is formed by the connection of an aromatic hydrocarbon ring and an aromatic heterocyclic group. When there are multiple aromatic hydrocarbon rings or aromatic heterocyclic groups, they can be the same or different. The number of carbon atoms is 8 or more and 36 or less. [Crosslinking group K] ， R 21 ~R 23 Each can independently represent an alkyl group having 6 or fewer hydrogen atoms. R 24 ~R 26 Each can independently represent an alkyl group or an alkoxy group with 6 or fewer carbon atoms. p represents an integer from 1 to 4, q represents an integer from 1 to 4, and r represents an integer from 1 to 4. Ar 21 Ar 22 Each can independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents. Ar 21 Ar 22 The substituents that can be present are the same as those in the substituent group Z. "-*" indicates the bonding site.

2. The organic electroluminescent element according to claim 1, wherein, At least one of the materials containing partial structure A in the hole transport layer and the materials containing partial structure A in the light-emitting layer has two or more partial structures A.

3. The organic electroluminescent element according to claim 1, wherein, In the partial structure shown in equation (35), X and Y are N atoms.

4. The organic electroluminescent element according to claim 1, wherein, The Ar 0 The rings are benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetraphenylene ring, pyrene ring, benzo[a]pyrene ring, etc. Rings, triphenylene rings, acenaphthene rings, fluoranthene rings, fluorene rings, or monovalent groups formed by connecting 2 to 10 rings selected from these, or furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, etc. 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 azole rings, benzisothiazolium 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, quinazoline ketone rings, dibenzofuran rings, dibenzothiophene rings, indole-carbazole rings, phenanthridine rings, or monovalent groups formed by connecting 2 to 10 of these.

5. The organic electroluminescent element according to any one of claims 1 to 4, wherein, The material containing part of structure A in the hole transport layer is a polymer compound having repeating units as shown in formula (1). ， In equation (1), A represents a partial structure A. G represents an aromatic hydrocarbon group that can have substituents, or an N atom. Ar 2 This refers to a divalent aromatic hydrocarbon group having 6 or more but less than 60 carbon atoms that may have substituents, a divalent aromatic heterocyclic group having 3 or more but less than 60 carbon atoms that may have substituents, or a divalent group formed by directly or via a linking group of two or more groups selected from divalent aromatic hydrocarbon groups having 6 or more but less than 60 carbon atoms that may have substituents and divalent aromatic heterocyclic groups having 3 or more but less than 60 carbon atoms that may have substituents. Ar 20 This refers to a divalent aromatic hydrocarbon group consisting of 6 or more but less than 60 carbon atoms that can have substituents, or a divalent group formed by connecting multiple divalent aromatic hydrocarbon groups that can have substituents. The substituents may be any one or a combination thereof, of the substituent group Z, an aralkyl group having 7 to 40 carbon atoms, or a heterocyclic aralkyl group having 4 to 37 carbon atoms.

6. The organic electroluminescent element according to claim 5, wherein, The G is a group consisting of any one of a benzene ring that may have substituents, a fluorene ring that may have substituents, or a spirofluorene ring that may have substituents.

7. The organic electroluminescent element according to claim 5, wherein, The structure G is as shown in the following process 1. ， "-*" indicates that Ar 20 The bonding sites.

8. The organic electroluminescent element according to claim 5, wherein, The G is an N atom.

9. The organic electroluminescent element according to claim 8, wherein, The repeating unit shown in equation (1) is any one of the repeating units shown in equations (2)-1 to (2)-3 below. ， In equations (2)-1 to (2)-3, A has the same meaning as A in equation (1). Q represents -C(R) 5 (R) 6 )-、-N(R 7 - or -C(R) 11 (R) 12 )-C(R 13 (R) 14 )-, R 1 ~R 4 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. R 5 ~R 7 and R 11 ~R 14 Each can independently represent 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. The substituents that may be present are alkyl groups with 1 or more and 24 or fewer carbon atoms, alkoxy groups with 1 or more and 24 or fewer carbon atoms, aralkyl groups with 7 or more and 60 or fewer carbon atoms, aromatic hydrocarbon groups with 6 or more and 60 or fewer carbon atoms, or crosslinking groups. a and b are each independent integers from 0 to 4. c1 to c5 are each an independent integer from 0 to 3. Among them, at least one of c3 and c5 is 1 or higher. d1 to d4 are each an independent integer from 1 to 4. There are multiple R in this repeating unit 1 R 2 R 3 R 4 At that time, R 1 R 2 R 3 R 4 They can be the same or different.

10. The organic electroluminescent element according to claim 9, wherein, The crosslinking group is selected from the following crosslinking group group K. (Crosslinking group group K) ， R 21 ~R 23 Each can independently represent an alkyl group having 6 or fewer hydrogen atoms. R 24 ~R 26 Each can independently represent an alkyl group or an alkoxy group with 6 or fewer carbon atoms. p represents an integer from 1 to 4, q represents an integer from 1 to 4, and r represents an integer from 1 to 4. Ar 21 Ar 22 Each can independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents. Ar 21 Ar 22 The substituents that can be present are the same as those in the substituent group Z. "-*" indicates the bonding site.

11. The organic electroluminescent element according to claim 9, wherein, R in equation (2)-1 and equation (2)-2 1 R 2 R is an alkyl group having 1 or more and 6 or fewer carbon atoms that may have the substituents. 3 R 4 It is an alkyl group that can have 1 or more but less than 12 carbon atoms having the substituent.

12. The organic electroluminescent element according to claim 9, wherein, R in equation (2)-1 5 ~R 7 and R 11 ~R 14 Each of the substituents can be an alkyl group having 1 or more and 24 or less carbon atoms, an alkoxy group having 1 or more and 24 or less carbon atoms, an aralkyl group having 7 or more and 60 or less carbon atoms, or an aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms.

13. The organic electroluminescent element according to claim 5, wherein, In the formula (1) -Ar 20 -A is represented by the following formula (15), ， In equation (15), X and Y each independently represent a C atom or a N atom, and a ring with X, Y, and N is equivalent to ring HA in equation (31). Ar 1 This indicates a divalent aromatic hydrocarbon group having 6 or more but less than 60 carbon atoms that may have substituents, or a divalent group formed by connecting multiple divalent aromatic hydrocarbon groups having 6 or more but less than 60 carbon atoms that may have substituents. The substituents may be any one of the substituent group Z or a combination thereof. Ar 3 Ar 4 Each of the following can independently represent an aromatic hydrocarbon group having 6 or more but less than 60 carbon atoms, an aromatic heterocyclic group having 3 or more but less than 60 carbon atoms, or a monovalent group formed by connecting two or more groups selected from aromatic hydrocarbon groups having 6 or more but less than 60 carbon atoms and aromatic heterocyclic groups having 3 or more but less carbon atoms. The substituents can be any of the substituent group Z or a combination thereof. Among them, in Ar 1 Ar 3 Ar 4 In at least one of them, the structure bonded to the cyclic HA is a benzene ring. * indicates the bonding site with G.

14. The organic electroluminescent element according to claim 13, wherein, Ar in equation (15) 3 and Ar 4 Each of them independently possesses a structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-17, and e-1 to e-4 as shown in process 2 below. ， These structures can also have substituents. In the figure, "-*" indicates the bonding site with ring HA. When there are multiple "-*", any one of them represents the bonding site with ring HA. R 3A and R 3B Each can be an independent straight-chain, branched, or cyclic alkyl group that may have substituents. The substituents may be any one of the substituent group Z or a combination thereof.

15. The organic electroluminescent element according to claim 13, wherein, In the formula (1) -Ar 20 -A is represented by the following formula (16), ， In equation (16), X, Y, and * have the same meaning as X, Y, and * in equation (15). A ring having X, Y, and N is similarly equivalent to the ring HA in equation (15). Ar 1’ This indicates direct bonding or Ar in equation (15). 1 The residues that are bonded to the cyclic HA when the structure is a benzene ring. Ar 3’ Ar 4’ Represents a hydrogen atom or Ar in equation (15) 3 Ar 4 The residues that are bonded to the cyclic HA when the structure is a benzene ring.

16. The organic electroluminescent element according to claim 5, wherein, The material containing part of structure A in the hole transport layer further has repeating units as shown in the following formula (3). ， In equation (3), Ar 13 This indicates an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents but does not contain part of structure A. Ar 14 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 via a linking group of two or more groups selected from divalent aromatic hydrocarbon groups that may have substituents and divalent aromatic heterocyclic groups that may have substituents.

17. An organic EL display device comprising an organic electroluminescent element as described in any one of claims 1 to 4.

18. An organic EL lighting device comprising an organic electroluminescent element as claimed in any one of claims 1 to 4.

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