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

Abstract

This organic electroluminescent element comprises, on a substrate, a positive electrode, a negative electrode, and an organic layer between the positive electrode and the negative electrode. The organic layer has a hole transport layer, and a light-emitting layer adjacent to the hole transport layer. At least one of materials contained in the hole transport layer and at least one of materials contained in the light-emitting layer both have the same partial structure A represented by formula (31). The ring HA is an aromatic heterocyclic ring, which may have a substituent, of a single ring or 2-6 fused rings. Ar0 is an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group obtained by linking a plurality of at least two groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. n1 is 0 or an integer equal to or less than the number in which Ar0 can be substituted for the ring HA.

Description

[Technical field]

[0001] The present invention relates to an organic electroluminescent device, and an organic EL display device and an organic EL lighting device that have the organic electroluminescent device. [Background technology]

[0002] Methods for forming an organic layer in an organic electroluminescent device include a vacuum deposition method and a wet film formation method. The vacuum deposition method has the advantage that lamination is easy, improving charge injection from the anode and / or cathode, and easily confining excitons in the light-emitting layer. On the other hand, the wet film formation method has the advantages that it does not require a vacuum process, is easy to make a large area, and can easily form a layer containing multiple materials with various functions by using a coating liquid in which multiple materials with various functions are mixed. However, since it is difficult to form layers using the wet film formation method, the driving stability is inferior to that of elements formed by the vacuum deposition method, and with the exception of a few, they have not yet reached a practical level.

[0003] In order to perform lamination by the wet film-forming method, a charge-transporting polymer having a crosslinkable group is desired, and its development is being carried out. For example, Patent Document 1 discloses an organic electroluminescence device produced by laminating multiple layers by the wet film-forming method. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2013 / 080696 Summary of the Invention [Problem to be solved by the invention]

[0005] However, lamination by the conventional wet film formation method has a problem in terms of hole transport efficiency between laminated layers, for example, between a light-emitting layer and a hole-transport layer.

[0006] Patent Document 1 discloses that the host compound of the light-emitting layer should have a structure common to that of the compound constituting the hole transport layer from the viewpoint of charge transport. However, the disclosed structures are only a small part of the whole, and it is not clear what other structures can achieve this effect. In addition, there is still room for further study regarding the overall effect of the organic electroluminescent device, such as brightness and driving life.

[0007] An object of the present invention is to provide an organic electroluminescent device having high brightness and a long operating life. Means for solving the problem

[0008] The present inventors have found that in 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, and both a material contained in the hole transport layer and a material contained in the light-emitting layer contain, as a partial structure, a specific structure containing a single ring or an aromatic heterocycle having 2 to 6 condensed rings, which is an electron-withdrawing structure, and the performance of the organic electroluminescent device is improved. The gist of the present invention is as follows [1] to

[19] .

[0009] [1] An organic electroluminescence device having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, the organic layer having a hole transport layer and a light emitting layer adjacent to the hole transport layer, wherein at least one material contained in the hole transport layer and at least one material contained in the light emitting layer both have the same partial structure A represented by the following formula (31):

[0010] [ka]

[0011] (In formula (31), Ring HA represents a monocyclic or 2-6 condensed ring aromatic heterocycle which may have a substituent. The benzene ring in the formula (31) may have a substituent. Ar 0represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking together two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. n1 is 0 or Ar in the ring HA. 0 represents an integer equal to or smaller than the number that can be substituted. When n1 is 2 or more, multiple Ar 0 may be the same or different.)

[0012] [2] The organic electroluminescent device according to [1], wherein at least one of the material having the partial structure A contained in the hole transport layer and the material having the partial structure A contained in the light-emitting layer has two or more partial structures A.

[0013] [3] The organic electroluminescent device according to [1] or [2], wherein the partial structure A represented by the formula (31) is a structure represented by any one of the following formulas (33) to (35):

[0014] [ka]

[0015] (In formulas (33) to (35), Ar 0 and n1 has the same meaning as in formula (31). The benzene ring in formulae (33) to (35) may have a substituent. Each of X and Y independently represents a C atom or a N atom. When X and Y are C atoms, Ar 0 may be bonded.)

[0016] [4] The organic electroluminescent device according to [3], wherein in the partial structure represented by the formula (35), X and Y are N atoms.

[0017] [5] The organic electroluminescent device according to any one of [1] to [4], wherein the material having the partial structure A contained in the hole transport layer is a polymer compound having a repeating unit represented by the following formula (1):

[0018] [ka]

[0019] (In formula (1), A represents partial structure A. G represents an aromatic hydrocarbon group which may have a substituent, or a nitrogen atom. Ar 2 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group. Ar 20 represents a direct bond, a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together.

[0020] [6] The organic electroluminescent device according to [5], wherein G is a group consisting of a benzene ring which may have a substituent, a fluorene ring which may have a substituent, or a spirofluorene ring which may have a substituent.

[0021] [7] The organic electroluminescent device according to [5], wherein G is a N atom.

[0022] [8] The organic electroluminescent device according to [7], wherein the repeating unit represented by the formula (1) is a repeating unit represented by any one of the following formulae (2)-1 to (2-3):

[0023] [ka]

[0024] (In formulas (2)-1 to (2)-3, A has the same meaning as A in the above formula (1). Q is -C(R5 )(R 6 )-, -N(R 7 )-or-C(R 11 )(R 12 )-C(R 13 )(R 14 )-represents. R 1 ~R 4 each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. R 5 ~R 7 and R 11 ~R 14 each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. a and b each independently represents an integer of 0 to 4. c1 to c5 each independently represents an integer of 0 to 3. However, at least one of c3 and c5 is 1 or greater. d1 to d4 each independently represents an integer of 1 to 4. R 1 , R 2 , R 3 , R 4 When there are a plurality of in the repeating unit, R 1 , R 2 , R 3 , R 4 may be the same or different.)

[0025] [9] -Ar in the above formula (1) 20 The organic electroluminescent device according to any one of [5] to [8], wherein A is represented by the following formula (15):

[0026] [ka]

[0027] (In formula (15), X and Y each independently represent a C atom or an N atom. The ring having X, Y and N corresponds to the ring HA in formula (31). Ar 1 represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together. Ar 3 , Ar 4 each independently represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. However, Ar 1 , Ar 3 , Ar 4 In at least one of these, the structure attached to the ring HA is a benzene ring. * indicates the binding site for G.)

[0028]

[10] -Ar in the above formula (1) 20 The organic electroluminescent device according to [9], wherein -A is represented by the following formula (16):

[0029] [ka]

[0030] (In formula (16), X, Y, and * are defined as in formula (15). The ring having X, Y and N corresponds to ring HA as in formula (15). Ar 1 ' is a direct bond or in the formula (15), Ar 1 This represents a residue when the structure bonded to the ring HA is a benzene ring. Ar 3 ', Ar 4 ' is a hydrogen atom or, in the formula (15), Ar 3 , Ar 4 This represents a residue in which the structure bonded to the ring HA is a benzene ring.)

[0031]

[11] The organic electroluminescent device according to any one of [5] to

[10] , wherein the material having the partial structure A contained in the hole transport layer further has a repeating unit represented by the following formula (3):

[0032] [ka]

[0033] (In formula (3), Ar 13 represents an aromatic hydrocarbon group which does not contain the partial structure A and which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar 14 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group.

[0034]

[12] The organic electroluminescent device according to any one of [1] to

[11] , wherein the light-emitting layer contains a low-molecular-weight compound having the partial structure A, and the low-molecular-weight compound is a compound represented by any one of the following formulas (10) to (12) having a molecular weight of 5,000 or less:

[0035] [ka]

[0036] (In formulas (10) to (12), A is the partial structure A. B represents a single bond or an arbitrary partial structure. Each of na, nb, and nc represents an integer of 1 to 5. When na, nb, and nc are 2 or more, the multiple A, B, and AB may be the same or different.)

[0037]

[13] The organic electroluminescent device according to

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

[0038] [ka]

[0039] (In formula (10A), HA represents any one of trivalent aromatic heterocyclic groups represented by the following structural formulas (10A-a), (10A-b), and (10A-c). Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. Xa 2 , Ya 2 and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. g11, h11, and j11 each independently represent an integer of 0 to 6. At least one of g11, h11, and j11 is an integer of 1 or more. If g11, h11, and j11 are 2 or more, Xa 1 , Ya 1 , Za 1 may be the same or different. R 31 represents a hydrogen atom or a substituent, and four R 31 may be the same or different.)

[0040] [ka]

[0041] (In formulas (10A-a) to (10A-c), * represents a bonding position.)

[0042]

[14] The organic electroluminescent device according to

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

[0043] [ka]

[0044] (In formulas (10A-1) to (10A-3), Xa 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 , Za 2 has the same meaning as in equation (10). R 33 represents a hydrogen atom or a substituent, and a plurality of R 33 may be the same or different. g11', h11' and j11' each independently represents an integer of 0 to 5. When g11', h11', and j11' are 2 or more, multiple Xa 1 , Ya 1 , Za 1 may be the same or different.)

[0045]

[15] The organic electroluminescent device according to

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

[0046] [ka]

[0047] (In formula (10B), A has the same meaning as in the above formula (10). Xb 1 , Yb 1 , and Zb 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. p12, q12, and r12 each independently represent an integer of 0 to 6. If p12, q12, r12 are ≥2, multiple Xbs 1 , Yb 1 , Zb 1 may be the same or different. q13 and r13 each independently represents 0 or 1. However, q12 and q13 are not 0 at the same time, and r12 and r13 are not 0 at the same time. Yb when q13 is 0 2 and Zb when r13 is 0 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. Yb when q13 is 1 2 is a direct bond. Zb when r13 is 1 2 is a direct bond.)

[0048]

[16] The organic electroluminescent device according to

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

[0049] [ka]

[0050] (In formula (10B-1), A, Xb 1 , Yb 1 , Zb 1 , Yb 2 , Zb 2 , q13 and r13 have the same meanings as in formula (10B). p12', q12' and r12' each independently represents an integer of 0 to 5. If p12', q12', or r12' is 2 or more, multiple Xb 1 , Yb 1 , Zb 1 may be the same or different. q15 and r15 each independently is 4 or 5. R 33 is a hydrogen atom or a substituent. In formula (10B-1), 33 may be the same or different.)

[0051]

[17] The organic electroluminescent device according to

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

[0052] [ka]

[0053] (In formula (12A), Ring HA, Ar 0 has the same meaning as in the above formula (31). nc has the same meaning as in formula (12). Xc 1 and Yc 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. Xc 2 and Yc 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. s11 and t11 each independently represents an integer of 0 to 6. If s11, t11 are 2 or more, multiple Xc 1 , Yc 1 may be the same or different. R 31 represents a hydrogen atom or a substituent. u11 is a substituent R 31 are the numbers that can be substituted. u12 is a substituent Ar 0 are the numbers that can be substituted. If u11 is 2 or more, multiple R 31 may be the same or different.)

[0054]

[18] An organic EL display device comprising the organic electroluminescent element according to any one of [1] to

[17] .

[0055]

[19] An organic electroluminescence lighting device comprising the organic electroluminescence element according to any one of [1] to

[17] . Effect of the Invention

[0056] According to the present invention, it is possible to provide an organic electroluminescent device having high brightness and a long operating life.

[0057] The reason why the organic electroluminescent device according to one embodiment of the present invention exhibits the above-mentioned effects is not clear, but the following is thought to be the reason. The organic electroluminescence device of the present invention contains a material (hereinafter, sometimes referred to as a "material containing partial structure A") having a specific structure containing a monocyclic or 2-6 condensed ring aromatic heterocyclic group, which is an electron-attracting structure, as a partial structure (in the present invention, referred to as "partial structure A") in both the hole transport layer and the light emitting layer. The partial structure A is easy to localize the LUMO and has high electron durability. Therefore, it is considered that deterioration of the hole transport layer caused by electrons leaking from the light emitting layer to the hole transport layer is suppressed. Furthermore, it is considered that the electrons localized in the vicinity of the interface of the hole transport layer with the light emitting layer contribute to recombination in the light emitting layer, and the light emitting efficiency is improved. Furthermore, it is considered that the voltage is reduced by efficiently transporting electrons and holes. [Brief description of the drawings]

[0058] [Figure 1] 1 is a schematic cross-sectional view showing an example of the structure of an organic electroluminescent device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] An organic electroluminescent device according to one embodiment of the present invention, and an organic EL display device and an organic EL lighting device having the organic electroluminescent device will be described in detail below. 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 go beyond the gist of the invention.

[0060] [Partial structure A] The organic electroluminescent device of the present invention is 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 having 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 both have the same partial structure A represented by the following formula (31):

[0061] [ka]

[0062] (In formula (31), Ring HA represents a monocyclic or 2-6 condensed ring aromatic heterocycle which may have a substituent. The benzene ring in the formula (31) may have a substituent. Ar 0 represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking together two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. n1 is 0 or Ar in the ring HA. 0 represents an integer equal to or smaller than the number that can be substituted. When n1 is 2 or more, multiple Ar 0 may be the same or different.)

[0063] The material containing partial structure A contained in the hole transport layer and the material containing partial structure A contained in the light emitting layer have partial structure A represented by the above formula (31), and it is an important constituent element of the present invention that they have the same partial structure A. The effect of the present invention can be obtained by the material contained in the hole transport layer and the material contained in the light emitting layer having the common partial structure A represented by formula (31).

[0064] In the present invention, it is more preferable that either one or both of the partial structure A-containing material contained in the hole transport layer and the partial structure A-containing material contained in the light emitting layer are partial structure A-containing materials having two or more partial structures A. It is particularly preferable that the partial structure A-containing material contained in the hole transport layer and the partial structure A-containing material contained in the light emitting layer are both partial structure A-containing materials having two or more identical partial structures A. With such a combination, it is expected that the electronic durability of the organic electroluminescent element will be further improved, and the organic electroluminescent element will have high brightness and a long life.

[0065] Here, the partial structure A-containing material having two or more identical partial structures A means that, when the partial structure A-containing material having two or more identical partial structures A is a low molecular weight compound, one compound has two or more identical partial structures A. When the partial structure A-containing material having two or more identical partial structures A is a high molecular weight compound, one repeating unit has two or more identical partial structures A.

[0066] In the present invention, it is also preferable that either or both of the partial structure A-containing material contained in the hole transport layer and the partial structure A-containing material contained in the light-emitting layer contain two or more materials having the partial structure A. With such a combination, it is expected that the electronic durability of the organic electroluminescent device will be further improved, and the organic electroluminescent device will have high brightness and a long life.

[0067] The partial structure A-containing material contained in the hole transport layer is not particularly limited, but is preferably a polymer compound. As the partial structure A-containing material of the polymer compound, a polymer compound having a repeating unit represented by the formula (1) shown below is preferably mentioned.

[0068] The material containing the partial structure A contained in the light-emitting layer is not particularly limited, but is preferably a low molecular weight compound.

[0069] When the partial structure A-containing material is a polymer compound, the number of partial structures A contained in the polymer compound is preferably equal to or greater than the number of partial structures A contained in the repeating units of the polymer compound. When two partial structures A exist in all repeating units of the polymer compound, the number of partial structures A contained in the polymer compound is twice the repeating units of the polymer compound. When the polymer compound has multiple repeating units, it is sufficient that at least one repeating unit has the partial structure A.

[0070] The bonding method of the partial structure A in the partial structure A-containing material contained in the hole transport layer and the partial structure A-containing material contained in the light emitting layer is not particularly limited.

[0071] From the viewpoint of charge transport properties and electron durability, in both the hole transport layer and the light emitting layer, the partial structure A-containing material is preferably such that the benzene ring in the partial structure A is bonded in the partial structure A-containing material, as represented by the following formula (31)-2.

[0072] [ka]

[0073] (In formula (31)-2, * represents a bonding site in the material containing partial structure A.)

[0074] (HA) In the partial structure A represented by the formula (31), HA represents an aromatic heterocycle which may have a single ring or 2 to 6 condensed rings. The ring-forming atoms of the aromatic heterocycle are preferably any one of a nitrogen atom, an oxygen atom, and a sulfur atom in addition to a carbon atom.

[0075] As described below, the ring HA is preferably a dibenzofuran ring, a dibenzothiophene ring, a pyridine ring, a pyrimidine ring, or a 1,3,5-triazine ring, and particularly preferably a 1,3,5-triazine ring.

[0076] (Ar 0 ) In the partial structure A represented by the formula (31), Ar 0 represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent.

[0077] The aromatic hydrocarbon group preferably has a carbon number of 6 or more and 60 or less. Specific examples include a monovalent group of a 6-membered monocyclic ring or 2 to 5 condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, or a fluorene ring, or a monovalent group in which 2 to 10 rings selected from these are linked together. Preferably, it is a monovalent group in which benzene rings, naphthalene rings, fluorene rings or rings selected from these are linked together by 2 to 10 rings.

[0078] The aromatic heterocyclic group preferably has 3 or more and 60 or less carbon atoms. Specific examples thereof include monovalent groups of a 5- or 6-membered monocyclic ring or 2- to 4-condensed ring such as a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, a dibenzofuran ring, a dibenzothiophene ring, an indolocarbazole ring, or a phenanthroline ring, or a monovalent group formed by connecting 2 to 10 of these. Preferred are monovalent groups of 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 indolocarbazole ring, or a phenanthroline ring, or a monovalent group in which 2 to 10 of these are linked together.

[0079] The monovalent group to which two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are linked may be a group to which multiple identical groups are linked, or a group to which multiple different groups are linked. The total number of linked aromatic hydrocarbon groups and / or aromatic heterocyclic groups is preferably 2 to 10.

[0080] Ar 0 is preferably an aromatic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon group which is substituted with an aromatic heterocyclic group which may have a substituent.

[0081] (Preferred partial structure A) The partial structure A represented by formula (31) is preferably a structure represented by the following formulae (33) to (35) from the viewpoint of charge transport properties and electron durability.

[0082] [ka]

[0083] (In formulas (33) to (35), Ar 0 and n1 has the same meaning as in formula (31). The benzene ring in formulae (33) to (35) may have a substituent. Each of X and Y independently represents a C atom or a N atom. When X and Y are C atoms, Ar 0 may be bonded.)

[0084] The above formula (35) is preferably represented by the following formula (36) from the viewpoint of charge transport properties and electron durability, and is more preferably represented by the following formula (37). In the structure represented by formula (37), electrons are donated and received at the biphenyl structure, which has high electron durability, thereby improving the electron durability of the compound, and as a result, it is believed that the operating life of the organic electroluminescent device is extended. In the following formula (36), the three benzene rings may have a substituent. In the following formula (37), the four benzene rings may have a substituent.

[0085] [ka]

[0086] The structure represented by the above formula (37) is more preferably a structure represented by the following formula (37-2).

[0087] [ka]

[0088] In formula (37-2), "*" and "*1" represent the bonding position of the partial structure A-containing material contained in the hole transport layer or the partial structure A-containing material contained in the light-emitting layer, or the bonding position of a substituent. In formula (37-2), it is preferable that at least "*1" is the bonding position of the partial structure A-containing material contained in the hole transport layer or the partial structure A-containing material contained in the light-emitting layer, or the bonding position of a substituent, because it is considered that the conjugation of the electron-durable biphenyl structure does not spread, the S1 level and T1 level are high, the excitons in the light-emitting layer are not easily deactivated, and the light-emitting efficiency is high. From this viewpoint, it is more preferable that "*1" and at least one "*" are bonded to something other than a hydrogen atom.

[0089] In the above formulas (35), (36), and (37), X and Y are preferably N atoms. Therefore, the partial structures represented by the above formulas (36) and (37) are structures represented by the following formulas (TzP) and (TzP-2), respectively (hereinafter, these may be referred to as "partial structure (TzP)" and "partial structure (TzP-2)"). chargeThis is preferable from the viewpoint of transportability and stability. The three benzene rings of the partial structure (TzP) and the four benzene rings of the partial structure (TzP-2) may have a substituent.

[0090] [ka]

[0091] Formula (TzP-2) is more preferably a structure represented by the following formula (TzP-3): The reason why the structure represented by the following formula (TzP-3) is preferred is the same as the reason why the structure represented by the above formula (37-2) is preferred.

[0092] [ka]

[0093] In formula (37-2), "*" and "*1" represent the bonding position of the partial structure A-containing material contained in the hole transport layer or the partial structure A-containing material contained in the light-emitting layer, or the bonding position of a substituent.

[0094] In the organic electroluminescent device of the present invention, it is preferable that the partial structure A-containing material contained in the hole transport layer and the partial structure A-containing material contained in the light emitting layer have a high similarity in the skeleton of the common structure as the partial structure A. A high similarity in the skeleton of the common structure as the partial structure A means that the molecular weight of the matching partial structure A is large.

[0095] When the partial structure A represented by the formula (31) is any one of the formulae (33) to (35), in the partial structure A-containing material contained in the hole transport layer or the partial structure A-containing material contained in the light-emitting layer, it is preferable that the benzene ring moiety of the partial structure A is a bonding site in the partial structure A-containing material contained in the hole transport layer or the partial structure A-containing material contained in the light-emitting layer.

[0096] In the formulas (31), (33) to (35), Ar 0The substituent that the benzene ring in the formulae (31), (33) to (37), (TzP) and (TzP-2) may have can be selected from the following substituent group Z.

[0097] [Substituent group Z] The substituent group Z includes the following substituents. For example, linear, branched, or cyclic alkyl groups having usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, or a dodecyl group; For example, an alkenyl group having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a vinyl group; For example, an alkynyl group having typically 2 or more carbon atoms and typically 24 or less, preferably 12 or less, such as an ethynyl group; For example, an alkoxy group having usually 1 or more and usually 24 or less, preferably 12 or less, carbon atoms, such as a methoxy group or an ethoxy group; For example, a phenoxy group, a naphthoxy group, a pyridyloxy group, etc., have a carbon number of usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less. below an aryloxy group or a heteroaryloxy group, For example, alkoxycarbonyl groups having usually 2 or more and usually 24 or less, preferably 12 or less, carbon atoms, such as a methoxycarbonyl group or an ethoxycarbonyl group; For example, dialkylamino groups having usually 2 or more and usually 24 or less, preferably 12 or less, carbon atoms, such as a dimethylamino group or a diethylamino group; For example, diarylamino groups having usually 10 or more, preferably 12 or more, and usually 36 or less, preferably 24 or less, such as a diphenylamino group, a ditolylamino group, or an N-carbazolyl group; For example, an arylalkylamino group, such as a phenylmethylamino group, which usually has 7 or more carbon atoms and usually has 36 or less, preferably 24 or less carbon atoms; For example, acyl groups such as an acetyl group and a benzoyl group, each of which usually has 2 or more carbon atoms and usually has 24 or less, preferably 12 or less carbon atoms; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, haloalkyl groups having typically 1 or more and typically 12 or less, preferably 6 or less, carbon atoms, such as a trifluoromethyl group; For example, an alkylthio group having usually 1 or more and usually 24 or less, preferably 12 or less, carbon atoms, such as a methylthio group or an ethylthio group; For example, an arylthio group or heteroarylthio group having usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less, such as a phenylthio group, a naphthylthio group, or a pyridylthio group; For example, a silyl group having usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less, such as a trimethylsilyl group or a triphenylsilyl group; For example, a siloxy group having usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less, such as a trimethylsiloxy group or a triphenylsiloxy group; Cyano group; For example, an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, or a monovalent group in which a plurality of identical or different monocyclic or condensed aromatic hydrocarbon rings are linked together, the carbon number of which is usually 6 or more and usually 36 or less, preferably 24 or less; For example, a thienyl group or the like, or a monovalent group in which a plurality of identical or different monocyclic or condensed aromatic heterocyclic rings are linked together, the number of carbon atoms being usually 3 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less: A monovalent aromatic group in which an aromatic hydrocarbon ring and an aromatic heterocyclic group are linked, and when there are multiple aromatic hydrocarbon rings or aromatic heterocyclic groups, they may be the same or different, and the monovalent aromatic group has 8 to 36 carbon atoms, preferably 24 or less.

[0098] Among the above-mentioned substituent group Z, the alkyl group, the alkoxy group, the aromatic hydrocarbon group, the aromatic heterocyclic group, the monovalent aromatic group to which the aromatic hydrocarbon ring and the aromatic heterocyclic group are linked is preferable. From the viewpoint of charge transportability, it is more preferable that the compound has no substituent or has a monovalent aromatic group to which the aromatic hydrocarbon group, the aromatic heterocyclic group, the aromatic hydrocarbon ring and the aromatic heterocyclic group are linked.

[0099] Each of the substituents in the above-mentioned substituent group Z may further have a substituent. Examples of the substituent include the same ones as those in the above-mentioned substituent group Z. Preferably, the compound has no further substituent, or has an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, a phenyl group, or a crosslinkable group described below as a further substituent. From the viewpoint of charge transportability, it is more preferable that the compound has no further substituent.

[0100] [Polymer compound] An example of a polymer compound that is a material containing partial structure A and is included in the hole transport layer, which is one embodiment of the present invention, is a polymer compound that contains a repeating unit represented by the following formula (1) (hereinafter, may be referred to as the "polymer of the present embodiment").

[0101] [ka]

[0102] (In formula (1), A represents partial structure A. G represents an aromatic hydrocarbon group which may have a substituent, or a nitrogen atom. Ar 2 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group. Ar 20represents a direct bond, a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together.

[0103] (G) In the repeating unit represented by the formula (1), G represents an aromatic hydrocarbon group which may have a substituent, or an N atom. From the viewpoint of excellent charge transport properties and of the LUMO distributed around the partial structure A and the HOMO distributed in the main chain being separately localized, G is preferably a group consisting of a benzene ring which may have a substituent, a fluorene ring which may have a substituent, or a spirofluorene ring which may have a substituent, and more preferably the structure shown in the following scheme 1. The following structure may have a substituent. In the figure, "-*" represents Ar 20 represents the binding site with

[0104] [ka]

[0105] When G is an aromatic hydrocarbon group which may have a substituent, the optional substituent is preferably any one of the above-mentioned substituent group Z, an aralkyl group having 7 to 40 carbon atoms, or an aralkyl group of a heterocycle having 4 to 37 carbon atoms, or a combination thereof. Among them, from the viewpoint of durability, each occurrence of each of them may be the same or different, and is preferably an alkyl group having 1 to 24 carbon atoms, an aralkyl group having 7 to 40 carbon atoms, an aralkyl group of a heterocycle having 3 to 37 carbon atoms, an arylamino group having 10 to 24 carbon atoms, an aromatic hydrocarbon group having 6 to 36 carbon atoms, or an aromatic heterocycle group having 3 to 36 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, an aralkyl group of a heterocycle having 3 to 27 carbon atoms, an aromatic hydrocarbon group having 6 to 24 carbon atoms, or an aromatic heterocycle group having 3 to 24 carbon atoms, and even more preferably an aromatic hydrocarbon group having 6 to 24 carbon atoms. From the viewpoint of charge transportability, each occurrence of each of the groups may be the same or different, and each group is preferably an aromatic hydrocarbon group having 6 to 24 carbon atoms or an aromatic heterocyclic group having 3 to 24 carbon atoms, more preferably a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group, an indolocarbazolyl group, an indenocarbazolyl group, or an indenofluorenyl group. In particular, when the group is bonded to the 9-position of spirobifluorene or fluorene, the conjugation is broken, and the LUMO distributed in the partial structure A and the HOMO distributed in the main chain are connected to each other. but From the viewpoint of further localization, G is preferably a fluorenyl group or an indenofluorenyl group. From the viewpoint of ease of synthesis and charge transport stability, it is most preferable that G has no substituent.

[0106] From the viewpoint of excellent charge transport properties, particularly excellent hole transport properties, G is preferably an N atom (nitrogen atom).

[0107] (Ar 2 , Ar 20 ) In the repeating unit represented by the formula (1), Ar 2 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group formed by linking two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent.

[0108] Ar 20 represents a direct bond, a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together.

[0109] Ar 2 , Ar 20The aromatic hydrocarbon group preferably has a carbon number of 6 or more and 60 or less. Specific examples include divalent groups of a 6-membered monocyclic ring or 2 to 5 condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, or a divalent group in which 2 to 10 rings selected from these are linked together.

[0110] Ar 2 The aromatic heterocyclic group preferably has 3 or more and 60 or less carbon atoms. Specific examples thereof include a divalent group of a 5- or 6-membered monocyclic or 2- to 4-condensed ring such as a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a perimidine ring, a quinazoline ring, or a quinazolinone ring, or a divalent group in which 2 to 10 rings selected from these are linked.

[0111] Ar 2 The divalent group having two or more groups selected from the aromatic hydrocarbon group which may have a substituent and the aromatic heterocyclic group which may have a substituent linked together may be a group having a plurality of the same groups linked together, or a group having a plurality of different groups linked together. When a plurality of groups are linked together, it is preferable that the group has 2 to 10 groups linked together.

[0112] Ar 2 is preferably a divalent group to which one or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are bonded directly or via a linking group, from the viewpoints of excellent charge transport properties and excellent durability. . RenWhen a linking group is present, it is preferably an oxygen atom or a carbonyl group. Since the triplet level can be increased by forming a non-conjugated structure with an aromatic ring, a structure in which phenylene rings are linked together via an oxygen atom or a carbonyl group is preferred. The charge transport property is improved by expanding the π-conjugated system, and from the viewpoint of excellent stability, a benzene ring or a fluorene ring is preferable. The main chain structure is one in which the spread of the π-conjugated system is inhibited, the excited singlet energy level (S1) and the excited triplet energy level (T1) are high, and quenching due to energy transfer from the emitting exciton is suppressed, resulting in excellent luminescence efficiency. From this viewpoint, a phenylene having a fluorene ring and an alkyl group and but Bonding twist structures are particularly preferred. Among these, a structure containing a phenylene group having a methyl group is particularly preferred in view of the difficulty of synthesis and purification of the monomer intermediate.

[0113] Ar 20 is preferably a group in which 1 to 9 divalent aromatic hydrocarbon groups which may be directly bonded or substituted are linked, and more preferably a group in which 1 to 7 divalent aromatic hydrocarbon groups which may be directly bonded or substituted are linked, from the viewpoint of localizing the LUMO distributed in the partial structure A and the HOMO distributed in the main chain, and is more preferably a group in which 1 to 5 benzene rings which may be substituted are linked, and particularly preferably a quaterphenylene group in which 3 benzene rings which may be substituted are linked together with the benzene ring contained in A. From the viewpoint of making the main chain and the partial structure A non-conjugated and thus making the LUMO distributed in the partial structure A and the HOMO distributed in the main chain more localized, it is preferable that the compound contains at least one benzene ring linked at the 1,3-positions, and it is more preferable that the compound contains two or more benzene rings linked at the 1,3-positions. In the case of a group in which a plurality of divalent aromatic hydrocarbon groups which may have a substituent are linked, it is preferred that all of them are linked by direct bonding from the viewpoint of charge transport properties or durability.

[0114] When G is a nitrogen atom, the hole transport property is improved, so Ar 2As the partial structure of , an aromatic hydrocarbon group which may have a substituent is preferable, a phenylene group which may have a substituent or a fluorenylene group which may have a substituent is more preferable, and a phenylene group which may have a substituent is particularly preferable. A benzene ring or a fluorene ring is preferably bonded to the benzene ring which is directly bonded to the nitrogen atom G, and a structure in which one or more phenylene groups are further bonded between the benzene ring which is directly bonded to the nitrogen atom and the fluorene ring is also preferable.

[0115] Ar 2 , Ar 20 The substituents that may be present when G is other than a direct bond are the same as those that may be present when G is an aromatic hydrocarbon group. From the viewpoint of ease of synthesis and charge transport stability, Ar 2 , Ar 20 Most preferably, has no substituent.

[0116] From the viewpoint of excellent electron durability, -Ar 20 -A is preferably represented by the following formula (15), and more preferably represented by the formula (16) shown below.

[0117] [ka]

[0118] (In formula (15), X and Y each independently represent a C atom or an N atom. The ring having X, Y and N corresponds to the ring HA in formula (31). Ar 1 represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together. Ar 3 , Ar 4each independently represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. However, Ar 1 , Ar 3 , Ar 4 In at least one of these, the structure attached to the ring HA is a benzene ring. * indicates the binding site for G.)

[0119] (Ar 1 ) Ar 1 represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together. The aromatic hydrocarbon preferably has 6 or more and 60 or less carbon atoms. Specifically, a divalent group of a 6-membered monocyclic ring or 2 to 5 condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, or a fluorene ring, or a divalent group in which 2 to 10 rings selected from these are linked together, is preferred. Ar 1 As the substituent that may be possessed by Ar, any one of the above-mentioned substituent group Z or a combination thereof can be used. From the viewpoint of durability and charge transportability, the above-mentioned Ar 2 It is preferable that the substituents are selected from the same ones that may be possessed by the group.

[0120] (Ar 3 , Ar 4 ) Ar 3 and Ar 4 are preferably each independently an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group in which two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are linked together.

[0121] The aromatic hydrocarbon group preferably has a carbon number of 6 or more and 60 or less. Specifically, a monovalent group of a 6-membered monocyclic ring or 2 to 5 condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, or a fluorene ring, or a monovalent group in which 2 to 10 rings selected from these are linked together is preferred.

[0122] The aromatic heterocyclic group preferably has a carbon number of 3 or more and 60 or less. Specific examples thereof include a monovalent group of a 5- to 6-membered monocyclic ring or a monovalent group of 2- to 4-condensed rings such as a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a perimidine ring, a quinazoline ring, and a quinazolinone ring, or a monovalent group in which 2 to 10 rings selected from these are connected.

[0123] The monovalent group in which two or more groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups are linked together is preferably a monovalent group in which 2 to 10 structures selected from the aromatic hydrocarbons and aromatic heterocyclic groups are linked together.

[0124] From the viewpoint of LUMO distribution, Ar 3 and Ar 4 each independently has 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 shown in Scheme 2 below. Furthermore, from the viewpoint of promoting the broadening of the LUMO of the molecule by having an electron-withdrawing group, structures selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-13, and e-1 to e-4 are preferred. Furthermore, from the viewpoint of the effect of trapping excitons formed in the light-emitting layer, which has a high triplet level, structures selected from a-1 to a-4, d-1 to d-13, and e-1 to e-4 are preferred. In order to prevent molecular aggregation, structures selected from d-1 to d-13 and e-1 to e-4 are more preferable. Ar is chosen because it is easy to synthesize and has excellent stability. 3 =Ar 4 The benzene ring structure of =d-3 is particularly preferred. These structures may have a substituent. In the diagram, "-*" indicates the binding site to the cyclic HA. When there are multiple "-*", any one of them represents the binding site to the cyclic HA.

[0125] [ka]

[0126] R in Scheme 2 above 3A and R 3B are each preferably independently a linear, branched or cyclic alkyl group which may have a substituent. The number of carbon atoms of the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 to 6, more preferably 3 or less, and further preferably a methyl group or an ethyl group.

[0127] R 3A and R 3B may be the same or different. Since the charge can be uniformly distributed around the nitrogen atom and the synthesis is easy, all R 3A and R 3B are preferably the same group.

[0128] Ar 3 and Ar 4As the substituent that may be possessed by Ar, any one of the above-mentioned substituent group Z or a combination thereof can be used. From the viewpoint of durability and charge transportability, the above-mentioned Ar 2 It is preferable that the substituents are selected from the same ones that may be possessed by the group.

[0129] [ka]

[0130] (In formula (16), X, Y, and * are defined as in formula (15). The ring having X, Y and N corresponds to ring HA as in formula (15). Ar 1 ' is a direct bond or in the formula (15), Ar 1 This represents a residue in which the structure bonded to the ring having X, Y, and N corresponding to the ring HA of the formula (I) is a benzene ring. Ar 3 ', Ar 4 ' is a hydrogen atom or, in the formula (15), Ar 3 , Ar 4 It represents a residue in which the structure bonded to the ring having X, Y, and N corresponding to the ring HA of is a benzene ring.

[0131] [Preferable repeating unit structure] The repeating unit represented by the formula (1) is preferably a repeating unit represented by any one of the following formulae (2)-1 to (2)-3.

[0132] [ka]

[0133] (In formulas (2)-1 to (2)-3, A has the same meaning as A in the above formula (1). Q is -C(R 5 )(R 6 )-, -N(R 7 )-or-C(R 11 )(R12 )-C(R 13 )(R 14 )-represents. R 1 ~R 4 each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. R 5 ~R 7 and R 11 ~R 14 each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. a and b each independently represents an integer of 0 to 4. c1 to c5 each independently represents an integer of 0 to 3. However, at least one of c3 and c5 is 1 or greater. d1 to d4 each independently represents an integer of 1 to 4. R 1 , R 2 , R 3 , R 4 When there are a plurality of in the repeating unit, R 1 , R 2 , R 3 , R 4 may be the same or different.)

[0134] (R 1 and R 2 ) R in the repeating units represented by the above formulas (2)-1 to (2-3) 1 and R 2 R each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. 1 and R 2are each preferably independently a linear, branched or cyclic alkyl group which may have a substituent. The number of carbon atoms of the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 to 6, more preferably 3 or less, and further preferably a methyl group or an ethyl group.

[0135] R 1 and R 2 When there are a plurality of in the repeating unit, R 1 and R 2 may be the same or different. Since the charge can be uniformly distributed around the nitrogen atom and the synthesis is easy, all R 1 and 2 are preferably the same group.

[0136] (R 3 and R 4 ) R in the repeating units represented by the above formulas (2)-1 to (2-3) 3 and R 4 R each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. 3 and R 4 are each preferably independently a linear, branched or cyclic alkyl group which may have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more, more preferably 4 or more, and is preferably 12 or less, even more preferably 8 or less, and is particularly preferably a hexyl group.

[0137] (R 5 ~R 7 and R 11 ~R 14 ) R 5 ~R 7 and R 11 ~R 14R each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. 5 ~R 7 and R 11 ~R 14 are preferably each independently an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.

[0138] The alkyl group is not particularly limited, but it is preferable that it is long in order to easily improve the solubility of the polymer, and it is preferable that it is short in order to improve the stability of the film and improve the charge transportability.The alkyl group preferably has 1 or more and 24 or less carbon atoms, more preferably 12 or less, even more preferably 8 or less, particularly preferably 6 or less, more preferably 2 or more, even more preferably 3 or more, and particularly preferably 4 or more.The alkyl group may have any structure of straight chain, branched or cyclic. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, a cyclohexyl group, and a dodecyl group.

[0139] The alkoxy group is not particularly limited, but in order to easily improve the solubility of the polymer, the alkoxy group preferably has 1 or more and 24 or less carbon atoms, more preferably has 12 or less, even more preferably has 8 or less, particularly preferably has 6 or less, more preferably has 2 or more, even more preferably has 3 or more, and particularly preferably has 4 or more carbon atoms. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, a tert-butoxy group, and a hexyloxy group.

[0140] The aralkyl group is not particularly limited, but since it is easy to improve the solubility of the polymer, it preferably has 7 or more and 60 or less carbon atoms, more preferably 40 or less, more preferably 8 or more, even more preferably 10 or more, and particularly preferably 12 or more. Specific examples of the aralkyl group include a 1,1-dimethyl-1-phenylmethyl group, a 1,1-di(n-butyl)-1-phenylmethyl group, a 1,1-di(n-hexyl)-1-phenylmethyl group, a 1,1-di(n-octyl)-1-phenylmethyl group, a phenylmethyl group, a phenylethyl group, a 3-phenyl-1-propyl group, a 4-phenyl-1-n-butyl group, a 1-methyl-1-phenylethyl group, a 5-phenyl-1-n-propyl group, a 6-phenyl-1-n-hexyl group, a 6-naphthyl-1-n-hexyl group, a 7-phenyl-1-n-heptyl group, an 8-phenyl-1-n-octyl group, and a 4-phenylcyclohexyl group.

[0141] The aromatic hydrocarbon group is not particularly limited, but in order to easily improve the solubility of the polymer, the aromatic hydrocarbon group preferably has 6 or more and 60 or less carbon atoms, more preferably 30 or less, even more preferably 24 or less, and particularly preferably 14 or less. Specific examples of the aromatic hydrocarbon group include monovalent groups of 6-membered monocyclic rings or 2 to 5 condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, or groups in which 2 to 8 ring structures selected from these are linked together. 4 consecutive It is the foundation that connects them.

[0142] From the viewpoint of improving charge transport and durability, R 5 ~R 7 is preferably an alkyl group or an aromatic hydrocarbon group, and R 5 and R 6 is more preferably an alkyl group, and R 7 is more preferably an aromatic hydrocarbon group, the preferred number of carbon atoms being as described above. In terms of improving solubility while providing excellent charge transport properties, R5 and 6 is preferably an alkyl group having 3 to 8 carbon atoms or an aralkyl group having 9 to 40 carbon atoms.

[0143] R 1 ~R 4 Alkyl groups, alkoxy groups, aralkyl groups, R 5 ~R 7 and R 11 ~R 14 The alkyl group, alkoxy group, aralkyl group and aromatic hydrocarbon group may further have a substituent. The further substituent that may be further possessed is the above-mentioned R 5 ~R 7 and R 11 ~R 14 Examples of the alkyl group, alkoxy group, aralkyl group and aromatic hydrocarbon group include those mentioned as preferred groups in the above, or the crosslinkable groups described below. R 1 ~R 4 Alkyl groups, alkoxy groups, aralkyl groups, R 5 ~R 7 and R 11 ~R 14 From the viewpoint of reducing the voltage, it is most preferable that the alkyl group, alkoxy group, aralkyl group and aromatic hydrocarbon group have no substituent.

[0144] R 5 ~R 7 and R 11 ~R 14 In the case where another layer is further coated and laminated after the polymer of the present embodiment is formed into a film, the substituent that may be further possessed by R is preferably a crosslinkable group described later from the viewpoint of improving insolubility in a solvent. 5 , R 6 , and R 11 ~R 14 It is preferable that any one of R has a crosslinkable group described later as a further substituent. 5 and R 6 It is more preferable that at least one of them has a crosslinkable group described below as an additional substituent.

[0145] (a, b, c1-c5, d1-d4) In the repeating units represented by formulae (2)-1 and (2)-2, a and b each independently represent an integer of 0 to 4. Each of a and b is preferably 2 or less, and both a and b are more preferably 0 or 1 at the same time.

[0146] In the repeating units represented by formulae (2)-1 to (2)-3, c1 to c5 each independently represent an integer of 0 to 3, provided that at least one of c3 and c5 is 1 or greater, and d1 to d4 each independently represent an integer of 1 to 4. It is preferable that c1 to c5 and d1 to d4 each independently is 2 or less. It is more preferable that both c1 and c2 are 0 or 1 at the same time. 1 in It is even more preferable that there is. At least one of c3 or c4, or both of c3 and c4, is preferably greater than or equal to 1. It is more preferable that both of c3 and c4 are 1. It is preferable that c5 is 1 or more. It is more preferable that c1 and c2, c3 and c4, and d1 to d4 are equal to each other. It is more preferable that c1 to c5 and d1 to d4 are all 1 or 2. It is particularly preferable that c1 to c5 and d1 to d4 are all 1.

[0147] In the repeating unit represented by the formula (2)-1, when both c1 and c2 are simultaneously 1 or 2 and both a and b are 2 or 1, R 1 and R 2 are most preferably bonded at symmetrical positions relative to each other. In the repeating unit represented by the formula (2)-2, when both c3 and c4 are simultaneously 1 or 2 and both a and b are 2 or 1, R 1 and R 2 are most preferably bonded at symmetrical positions relative to each other.

[0148] Here, R 1 and R 2and are bonded at positions symmetrical to each other will be explained using the following formulas (1-1) and (1-2) taking as an example the case where Q=C, c1=c2=1, and a=b=2 in the above formula (2)-1. R 1 and R 2 The fact that R and R are bonded at positions symmetrical to each other means that R and R are bonded at positions symmetrical to each other to the fluorene ring of the main chain in the following formulas (1-1) and (1-2). 1 and R 2 The binding position of Symmetric In this case, a 180 degree rotation around the main chain is considered to be the same structure. For example, in the following formula (1-1), R 1 ' and R 2 'And Symmetric , R 1 " and R 2 "And Symmetric Formula (1-1) and Formula (1-2) are considered to have the same structure.

[0149] [ka]

[0150] (Specific examples) Specific examples of preferred repeating unit structures include the following structures.

[0151] [ka]

[0152] [ka]

[0153] [ka]

[0154] [Terminal group] In this embodiment, the term "terminal group" refers to the structure of the terminal part of the polymer formed by the endcapping agent used at the end of the polymerization of the polymer. The terminal group of the polymer in this embodiment is usually a hydrocarbon group. From the viewpoint of charge transportability, the hydrocarbon group preferably has 1 to 60 carbon atoms, more preferably 1 to 40 carbon atoms, and even more preferably 1 to 30 carbon atoms.

[0155] The terminal group preferably includes the following: For example, linear, branched, or cyclic alkyl groups having usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, or a dodecyl group; For example, an alkenyl group having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a vinyl group; For example, an alkynyl group having typically 2 or more carbon atoms and typically 24 or less, preferably 12 or less, such as an ethynyl group; For example, aromatic hydrocarbon ring groups having usually 6 or more and usually 36 or less, preferably 24 or less, such as a phenyl group and a naphthyl group:

[0156] These hydrocarbon groups may further have a substituent. The further optional substituent is preferably an alkyl group or an aromatic hydrocarbon group. When there are a plurality of these further optional substituents, they may be bonded to each other to form a ring. The substituent that the terminal hydrocarbon group may further have is preferably an alkyl group or an aromatic hydrocarbon group, more preferably an aromatic hydrocarbon group, from the viewpoints of charge transportability and durability.

[0157] [Soluble group] The polymer of this embodiment preferably has a soluble group to exhibit solubility in a solvent. The soluble group in this embodiment is a group having a linear or branched alkyl or alkylene group having 3 to 24 carbon atoms, preferably 12 or less carbon atoms. Among these, preferred are alkyl, alkoxy, or aralkyl groups, such as n-propyl, 2-propyl, n-butyl, isobutyl, n-hexyl, and n-octyl groups. More preferred are n-hexyl and n-octyl groups. The soluble group may have a substituent.

[0158] (Number of soluble groups) The polymer of the present embodiment preferably has a large number of soluble groups in that a polymer solution that can be used in a wet film-forming method can be easily obtained, whereas the polymer of the present embodiment preferably has a small number of soluble groups in that a film thickness reduction caused by dissolving the lower layer in a solvent is small when another layer is formed on the layer formed using the polymer of the present embodiment by a wet film-forming method.

[0159] The number of soluble groups contained in the polymer of the present embodiment can be expressed as the number of moles per gram of the polymer. The number of soluble groups possessed by the polymer of this embodiment, expressed as the number of moles per gram of polymer, is usually 4.0 mmol or less, preferably 3.0 mmol or less, and more preferably 2.0 mmol or less, and is usually 0.1 mmol or more, and preferably 0.5 mmol or more, per gram of polymer. When the number of soluble groups is within the above range, the polymer is easily dissolved in a solvent, and a composition containing the polymer suitable for a wet film-forming method can be easily obtained. In addition, since the soluble group density is appropriate and the polymer has sufficient poor solubility in an organic solvent after drying with heating, a multilayer laminate structure can be formed by the wet film-forming method.

[0160] The number of soluble groups per 1 g of a polymer can be calculated from the molar ratio of monomers charged during synthesis and the structural formula, excluding the terminal groups from the polymer. Taking the case of polymer 1 represented by formula (HT-1) used in Example 1 described later, as shown below, the average molecular weight of the repeating units excluding the terminal groups in polymer 1 is 748.4, and the number of hexyl groups, which are soluble groups, per repeating unit is 1.3 on average. When calculated based on a simple proportionality, the number of soluble groups per gram of molecular weight is calculated to be 1.74 millimoles.

[0161] [ka]

[0162] [Crosslinkable group] The polymer of this embodiment may have a crosslinkable group. The crosslinkable group in the polymer of this embodiment may be present in the repeating unit represented by the formula (1) or may be present in a repeating unit other than the repeating unit represented by the formula (1). In particular, it is preferable that the aromatic hydrocarbon group or aromatic heterocyclic group bonded as a side chain has a crosslinkable group, since the crosslinking reaction is easily promoted. The presence of a crosslinkable group can cause a large difference in solubility in an organic solvent before and after a reaction (insolubilization reaction) caused by irradiation with heat and / or active energy rays.

[0163] The crosslinkable group refers to a group that reacts with a group constituting another molecule located in the vicinity of the crosslinkable group upon exposure to heat and / or active energy rays to form a new chemical bond. In this case, the reactive group may be the same as or different from the crosslinkable group.

[0164] The crosslinkable group is preferably a group containing a cyclobutene ring condensed with an aromatic ring or an alkenyl group bonded to an aromatic ring, and more preferably a group selected from the following crosslinkable group group K. The crosslinkable group is preferably contained in the polymer in the form of a further substitution on the substituent of each of the above structures.

[0165] (Crosslinkable group K) The crosslinkable group group K has the structure shown below.

[0166] [ka]

[0167] In the above crosslinkable group K, R 21 ~R 23 Each independently represents a hydrogen atom or an alkyl group. 24 ~R 26 each independently represents an alkyl group or an alkoxy group, p represents an integer of 1 to 4, q represents an integer of 1 to 4, and r represents an integer of 1 to 4. When p is 2 or more, multiple R 24 may be the same or different, and adjacent R 24 They may be bonded to each other to form a ring. When q is 2 or more, multiple R 25 may be the same or different, and adjacent R 25 They may be bonded to each other to form a ring. When r is 2 or more, multiple R 26 may be the same or different, and adjacent R 26 They may be bonded to each other to form a ring. Ar 1 , Ar 22 each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent. "-*" is the binding site.

[0168] R 21 ~R 26 Examples of the alkyl group of R include linear or branched chain alkyl groups having 6 or less carbon atoms. Examples include methyl, ethyl, n-propyl, 2-propyl, n-butyl, and isobutyl groups. More preferred are methyl and ethyl groups. 21 ~R 26 It is believed that when the alkyl group has 6 or less carbon atoms, the crosslinking reaction is not sterically hindered, and the film formed by the polymer of this embodiment is likely to be insolubilized.

[0169] R 24 ~R 26Examples of the alkoxy group include linear or branched chain alkoxy groups having 6 or less carbon atoms. Examples include methoxy, ethoxy, n-propoxy, 2-propoxy, and n-butoxy groups. More preferred are methoxy and ethoxy groups. 24 ~R 26 When the number of carbon atoms is 6 or less, it is considered that the crosslinking reaction is not sterically hindered, and the film formed by the polymer of this embodiment is likely to be insolubilized.

[0170] Ar 21 and Ar 22 Examples of the aromatic hydrocarbon group which may have a substituent include a 6-membered monocyclic ring or a 2- to 5-condensed ring such as a benzene ring or a naphthalene ring, each having one free valence. A benzene ring having one free valence is particularly preferred. Ar 22 may be a group in which two or more aromatic hydrocarbon groups, which may have a substituent, are bonded together. Examples of such groups include a biphenylene group and a terphenylene group, and a 4,4'-biphenylene group is preferred. Ar 21 and Ar 22 Examples of the aromatic heterocyclic group which may have a substituent include a 6-membered monocyclic ring or a 2- to 5-condensed ring such as a pyridine ring or a triazine ring, each having one free valence. In particular, a triazine ring having one free valence is preferred. Ar 21 , Ar 22 The substituents which may be possessed by are the same as those in the above-mentioned group Z of substituents.

[0171] As the crosslinkable group, a group that undergoes a cycloaddition reaction, such as an arylvinylcarbonyl group such as a cinnamoyl group, a benzocyclobutene ring having a monovalent free valence, or a 1,2-dihydrocyclobuta[a]naphthalene ring having a monovalent free valence, is preferred in terms of further improving the electrochemical stability of the element.

[0172] Among the crosslinkable groups, a group containing a cyclobutene ring condensed with an aromatic ring having a monovalent free valence, or a 1,2-dihydrocyclobuta[a]naphthalene ring having a monovalent free valence is preferred, in that the structure after crosslinking is particularly stable, and among these, a benzocyclobutene ring or a 1,2-dihydrocyclobuta[a]naphthalene ring having a monovalent free valence is more preferred. As the crosslinkable group, a 1,2-dihydrocyclobuta[a]naphthalene ring having a monovalent free valence is particularly preferred, in that the crosslinking reaction temperature is low.

[0173] (Number of crosslinkable groups) The crosslinkable groups of the polymer of the present embodiment are preferably large in number, since the polymer is sufficiently insolubilized by crosslinking and other layers can be easily formed thereon by a wet film-forming method, whereas the crosslinkable groups are preferably small in number, since the formed layer is less likely to crack, unreacted crosslinkable groups are less likely to remain, and the organic electroluminescent device is more likely to have a long life.

[0174] In the polymer of this embodiment, the number of crosslinkable groups present in one polymer chain is preferably 1 or more, more preferably 2 or more, and is preferably 200 or less, more preferably 100 or less.

[0175] The number of crosslinkable groups contained in the polymer of this embodiment can be expressed as the number per 1,000 molecular weight of the polymer. The number of crosslinkable groups possessed by the polymer of the present embodiment, expressed as the number per 1000 molecular weight of the polymer, is usually 3.0 or less, preferably 2.0 or less, and more preferably 1.0 or less, and is usually 0.01 or more, and preferably 0.05 or more, per 1000 molecular weight.

[0176] When the number of crosslinkable groups is within the above range, cracks are unlikely to occur, and a flat film is easily obtained from the polymer of this embodiment. In addition, since the crosslink density is appropriate, there are few unreacted crosslinkable groups remaining in the layer after the crosslinking reaction, and the life of the obtained element is unlikely to be affected. Furthermore, since the polymer has a sufficiently low solubility in organic solvents after the crosslinking reaction, a multi-layer laminate structure can be easily formed by a wet film-forming method.

[0177] The number of crosslinkable groups per 1000 molecular weight of the polymer can be calculated from the molar ratio of the monomers charged during synthesis and the structural formula, excluding the terminal groups from the polymer. Taking the case of polymer 1 represented by formula (HT-1) used in Example 1 described later as an example, the molecular weight of the repeating units excluding the terminal groups in polymer 1 is an average of 748.4, and the number of crosslinkable groups per repeating unit is 0.15. When calculated based on a simple proportionality, the number of crosslinkable groups per molecular weight of 1000 is calculated to be 0.20.

[0178] [ka]

[0179] [Repeating unit content] In the polymer of this embodiment, the content of the repeating unit represented by formula (1) is not particularly limited, but is usually contained in the polymer at 5 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, and particularly preferably 20 mol% or more. The polymer of this embodiment may be composed of only the repeating unit represented by formula (1), but may have a repeating unit other than formula (1) for the purpose of balancing various performances when made into an organic electroluminescent device. In that case, the content of the repeating unit represented by formula (1) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

[0180] [Other preferred repeating units that may be included] The polymer of the present embodiment preferably further contains a repeating unit represented by the following formula (3): The repeating unit represented by formula (3) is preferably a repeating unit represented by any one of the following formulas (3)-1, (3)-2, and (3)-3.

[0181] [ka]

[0182] (In formula (3), Ar 13 represents an aromatic hydrocarbon group which does not contain the partial structure A and which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar 14 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group.

[0183] [ka]

[0184] (In formulas (3)-1 to (3)-3, Ar 7 represents an aromatic hydrocarbon group which does not contain the partial structure A and which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Q is -C(R 5 )(R 6 )-, -N(R 7 )-or-C(R 11 )(R 12 )-C(R 13 )(R 14 )-represents. R 1 ~R 4 each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. R 5 ~R 7 and R 11 ~R 14 each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. a and b each independently represents an integer of 0 to 4. c1 to c5 each independently represents an integer of 0 to 3. However, at least one of c3 and c5 is 1 or greater. d1 to d4 each independently represents an integer of 1 to 4. R 1 , R 2 , R 3 , R 4 When there are a plurality of in the repeating unit, R 1 , R 2 , R 3 , R 4 may be the same or different. However, Q and R 1 ~R 4 represents Q and R in the formulas (2)-1 to (2-3). 1 ~ 4 The same structures and preferred ranges are also the same. Therefore, although the same symbols are used, they may be different. c1 to c5 and d1 to d4 can take the same values ​​as c1 to c5 and d1 to d4 in the formulas (2)-1 to (2)-3, and the preferred ranges are also the same. Therefore, although the same symbols are used, they may be different.)

[0185] (Ar 7 ) In the repeating units represented by the formulas (3)-1 to (3)-3, Ar 7 represents, independently in each repeating unit, an aromatic hydrocarbon group which does not contain the partial structure A and which may have a substituent, or an aromatic heterocyclic group which may have a substituent.

[0186] The aromatic hydrocarbon group preferably has 6 or more and 60 or less carbon atoms. Specific examples include a 6-membered monocyclic ring or a 2-5 condensed ring such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, a fluorene ring, etc., or a monovalent group in which a plurality of rings selected from these are linked. In the case of linking a plurality of rings, a monovalent group in which 2 to 10 rings are linked is preferred.

[0187] The aromatic heterocyclic group preferably has 3 or more and 60 or less carbon atoms. Specific examples thereof include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyrazine ring, a pyridazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, and the like, and a monovalent group in which a plurality of rings selected from these are linked. In the case of linking a plurality of rings, a monovalent group in which 2 to 10 rings are linked is preferable.

[0188] Ar 7 is preferably an aromatic hydrocarbon group which may have a substituent, from the viewpoints of excellent charge transportability and durability. Among them, a monovalent group of a benzene ring or fluorene ring which may have a substituent, i.e., a phenyl group or a fluorenyl group which may have a substituent, is more preferred, a fluorenyl group which may have a substituent, is further preferred, and a 2-fluorenyl group which may have a substituent is particularly preferred.

[0189] Ar 7 The substituent that the aromatic hydrocarbon group may have is not particularly limited as long as it does not significantly impair the properties of the polymer of the present embodiment. Preferred examples include groups selected from the above-mentioned substituent group Z or the above-mentioned crosslinkable groups. The substituent is preferably an alkyl group, an alkoxy group, an aromatic hydrocarbon group, an aromatic heterocyclic group not corresponding to the partial structure A, or the above-mentioned crosslinkable group, and more preferably an alkyl group.

[0190] Ar 7In terms of solubility in a coating solvent, a fluorenyl group substituted with an alkyl group having 1 to 24 carbon atoms is preferred, and a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms is particularly preferred. Furthermore, a 9-alkyl-2-fluorenyl group in which an alkyl group is substituted at the 9-position of a 2-fluorenyl group is preferred, and a 9,9'-dialkyl-2-fluorenyl group in which two alkyl groups are substituted is particularly preferred. By using a fluorenyl group in which at least one of the 9-position and the 9'-position is substituted with an alkyl group, the solubility in a solvent and the durability of the fluorene ring are likely to be improved. Furthermore, by using a fluorenyl group in which both the 9-position and the 9'-position are substituted with alkyl groups, the solubility in a solvent and the durability of the fluorene ring are likely to be further improved. Ar 7 It is preferable that the compound contains the crosslinkable group, since this improves the insolubility in a solvent during lamination coating after film formation.

[0191] From the viewpoint of insolubilization, it is preferable that the repeating units represented by formula (3)-1 to formula (3)-3 each containing at least one of the above-mentioned crosslinkable groups are contained as further substituents. The crosslinkable group is Ar 7 It is preferable that the aromatic hydrocarbon group represented by the following formula (1) is further substituted with a substituent which the aromatic hydrocarbon group represented by the following formula (1) may have.

[0192] (Specific examples) Specific examples of the repeating unit structures represented by the formulas (3)-1 to (3-3) include the following structures.

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] [Other repeating units] The polymer of the present embodiment may further contain a repeating unit represented by the following formula (4) or (5) in terms of charge transport properties and durability.

[0197] [ka]

[0198] In formula (4), R 8 and R 9 each independently represents a hydrogen atom, an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent.

[0199] In formula (5), Ar 10 represents a divalent aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group.

[0200] (R 8 and R 9 ) R 8 and R 9 Examples of the alkyl group, aromatic hydrocarbon group, and aromatic heterocyclic group include the alkyl group, aromatic hydrocarbon group, and aromatic heterocyclic group exemplified as the substituent group Z. The substituents that these groups may have are preferably the same as those in the substituent group Z or the crosslinkable group.

[0201] (Ar 10 ) Ar 10 As a specific structure, Ar 2 The substituents which these groups may have are preferably the same as those in the above-mentioned substituent group Z or the above-mentioned crosslinkable groups.

[0202] [Molecular weight of polymer] The weight average molecular weight (Mw) of the polymer of this embodiment is usually 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, further preferably 200,000 or less, particularly preferably 100,000 or less, and is usually 10,000 or more, preferably 15,000 or more.

[0203] When the weight average molecular weight of the polymer is equal to or less than the upper limit, the polymer tends to have good solubility in a solvent and excellent film-forming properties. When the weight average molecular weight of the polymer is equal to or more than the lower limit, the polymer's glass transition temperature, melting point, and vaporization temperature are prevented from decreasing, and the heat resistance may be improved. In addition, the coating film after the crosslinking reaction may have sufficient insolubility in organic solvents.

[0204] The number average molecular weight (Mn) of the polymer of this embodiment is usually 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, and particularly preferably 100,000 or less, and is usually 2,000 or more, preferably 4,000 or more, more preferably 8,000 or more, and even more preferably 20,000 or more.

[0205] The dispersity (Mw / Mn) of the polymer of this embodiment is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. Since the smaller the dispersity, the better, the lower limit is ideally 1. When the dispersity of the polymer is equal to or less than the upper limit, purification is easy, and the solubility in a solvent and the charge transport ability are good.

[0206] Usually, the weight average molecular weight and number average molecular weight of a polymer are determined by SEC (size exclusion chromatography) measurement. In SEC measurement, the higher the molecular weight component, the shorter the elution time, and the lower the molecular weight component, the longer the elution time. The weight average molecular weight and number average molecular weight are calculated by converting the elution time of the sample into molecular weight using a calibration curve calculated from the elution time of polystyrene (standard sample) with a known molecular weight.

[0207] [Preferred polymer] The polymer of the present embodiment is most preferably represented by any one of the following formulas (6a) to (6h).

[0208] [ka]

[0209] In each of the polymers of formulas (6a) to (6h), A, Q, R 1 , R 2 , R 3 , R 4 is the same as in the above formulas (2)-1 to (2)-3. 7 is the same as in the above formula (3)-1 to formula (3)-3. At least one A or Ar in each polymer 7 It is preferable that n and m each represent the number of repetitions.

[0210] [Specific example] Specific examples of the polymer of this embodiment other than the polymer 1 represented by formula (HT-1) and the polymers represented by formulas (HT-2) and (HT-4) used in the examples described later are shown below. The polymer of this embodiment is not limited to these. The numbers in the following chemical formulas represent the molar ratio of the repeating units. These polymers may be any of random copolymers, alternating copolymers, block copolymers, graft copolymers, etc., and the arrangement order of the repeating units is not limited.

[0211] [ka]

[0212] [ka]

[0213] [ka]

[0214] [ka]

[0215] [ka]

[0216] [Polymer manufacturing method] The method for producing the polymer of the present embodiment is not particularly limited. For example, the polymerization method may be a polymerization method based on the Suzuki reaction, a polymerization method based on the Grignard reaction, a polymerization method based on the Yamamoto reaction, a polymerization method based on the Ullmann reaction, or a polymerization method based on the Buchwald-Hartwig reaction. etc. So it can be manufactured.

[0217] In the case of the polymerization method by the Ullmann reaction and the polymerization method by the Buchwald-Hartwig reaction, for example, an aryl dihalide represented by the following formula (1a) (E represents a halogen atom such as I, Br, Cl, F, etc.) is reacted with a primary aminoaryl represented by formula (1b), and then further reacted with an aryl dihalide represented by formula (2a), thereby synthesizing the polymer of the present embodiment.

[0218] [ka]

[0219] In the above formula, A and R 1 ~ 2 , Q, a, b, c1, and d1 are defined as in the formulae (2)-1 to (2)-3. n and m represent the number of repetitions.

[0220] In the above polymerization method, the reaction for forming the N-aryl bond is usually carried out in the presence of a base such as potassium carbonate, sodium tert-butoxide, triethylamine, etc. It can also be carried out in the presence of a transition metal catalyst such as a copper or palladium complex.

[0221] [Low molecular compound] The partial structure A-containing material contained in the light-emitting layer according to one embodiment of the present invention is preferably a low molecular weight compound. The partial structure A-containing material of the low molecular weight compound is preferably a compound having a molecular weight of 5,000 or less and represented by the following formula (10), (11), or (12) (hereinafter, these compounds may be referred to as the "low molecular weight compound of this embodiment").

[0222] [ka]

[0223] (In formulas (10) to (12), A is the partial structure A. B represents a single bond or an arbitrary partial structure. Each of na, nb, and nc represents an integer of 1 to 5. When na, nb, and nc are 2 or more, the multiple A, B, and AB may be the same or different.)

[0224] (B) B in the above formula (10) and formula (11) is not particularly limited, but is preferably a functional group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a group in which two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group.

[0225] The functional group is preferably a group containing a structure having a hole transport property, a structure having an electron transport property, a structure that suppresses charge transport, a structure that imparts solubility in an organic solvent, a structure that inhibits crystallization and improves amorphousness, or a structure having light-emitting properties. As the structure having hole transport properties, an aromatic amine structure, that is, a group containing a structure in which at least one aromatic hydrocarbon group is bonded to a nitrogen atom of an amine, is preferred.

[0226] Examples of the group in which two or more groups selected from an aromatic hydrocarbon group, an aromatic heterocyclic group, an aromatic hydrocarbon group which may have a substituent, and an aromatic heterocyclic group which may have a substituent are linked directly or via a linking group include Ar 0 Those based on a structure similar to that of

[0227] As for the position of A to which B is bonded, it is preferable that at least one B is bonded to the ring HA in the partial structure A.

[0228] The low molecular weight compound of this embodiment is preferably a charge transport material in the light emitting layer. The low molecular weight compound of this embodiment is preferably a compound represented by the above formula (10) or (12).

[0229] The compound represented by formula (10) is preferably a compound represented by the following formula (10A) or (10B): The compound represented by formula (12) is preferably a compound represented by the following formula (12A):

[0230] [ka]

[0231] (In formula (10A), HA represents any one of trivalent aromatic heterocyclic groups represented by the following structural formulas (10A-a), (10A-b), and (10A-c). Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. Xa 2 , Ya 2 and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. g11, h11, and j11 each independently represent an integer of 0 to 6. At least one of g11, h11, and j11 is an integer of 1 or more. If g11, h11, and j11 are 2 or more, Xa 1 , Ya 1 , Za 1 may be the same or different. R 31 represents a hydrogen atom or a substituent. 31 may be the same or different.)

[0232] [ka]

[0233] (In formulas (10A-a) to (10A-c), * represents a bonding position.)

[0234] [ka]

[0235] (In formula (10B), A has the same meaning as in the above formula (10). Xb 1 , Yb 1 , and Zb 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. p12, q12, and r12 each independently represent an integer of 0 to 6. If p12, q12, r12 are ≥2, multiple Xbs 1 , Yb 1 , Zb 1 may be the same or different. q13 and r13 each independently represents 0 or 1. However, q12 and q13 are not 0 at the same time, and r12 and r13 are not 0 at the same time. Yb when q13 is 0 2 and Zb when r13 is 02 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. Yb when q13 is 1 2 is a direct bond. Zb when r13 is 1 2 is a direct bond.)

[0236] [ka]

[0237] (In formula (12A), Ring HA, Ar 0 has the same meaning as in the above formula (31). nc has the same meaning as in formula (12). Xc 1 and Yc 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. Xc 2 and Yc 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. s11 and t11 each independently represents an integer of 0 to 6. If s11, t11 are 2 or more, multiple Xc 1 , Yc 1 may be the same or different. R 31 represents a hydrogen atom or a substituent. u11 is a substituent R 31 are the numbers that can be substituted. u12 is a substituent Ar 0 are the numbers that can be substituted. If u11 is 2 or more, multiple R 31 may be the same or different.)

[0238] In the formulae (10A), (10B), and (12A), the aromatic hydrocarbon ring of the aromatic hydrocarbon group having 6 to 30 carbon atoms is preferably a 6-membered monocyclic ring or 2 to 5 condensed rings. Specific examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, and a fluoranthene ring. More preferred are a monocyclic ring or 2 to 3 condensed rings, and specific examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a fluorene ring. Of these, preferred are a benzene ring, a naphthalene ring, a phenanthrene ring, and a fluorene ring, and more preferred are a benzene ring or a fluorene ring.

[0239] In the above formulae (10A), (10B) and (12A), the aromatic heterocycle of the aromatic heterocyclic group having 3 to 30 carbon atoms is preferably a 5- or 6-membered monocycle or a 2- to 5-condensed ring thereof. Specific examples thereof include a furan ring, a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, an indolocarbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a perimidine ring, a quinazoline ring, and a quinazolinone ring. Among these, 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 indolocarbazole ring, or Phenanthroline In ringMore 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 indolocarbazole ring, and further preferably, it is a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, or an indolocarbazole ring.

[0240] Xa in the formula (10A) 2 , Ya 2 , Za 2 , Yb when q13=0 in the formula (10B) 2 , and Zb when r13=0 2 , Xc in the formula (12A) 2 , Yc 2 In the above formula, particularly preferred aromatic hydrocarbon rings are a benzene ring, a naphthalene ring, or a phenanthrene ring, and particularly preferred aromatic heterocycles are a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, or an indolocarbazole ring, with the aromatic hydrocarbon ring being more preferred.

[0241] R when it is a substituent 31 is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. From the viewpoint of improving durability and charge transportability, an aromatic hydrocarbon group which may have a substituent is more preferable. When R is a substituent, 31 When a plurality of are present, they may be different from each other.

[0242] The above-mentioned substituents which may be possessed by the hydrocarbon aromatic ring having 6 to 30 carbon atoms, the substituents which may be possessed by the heteroaromatic ring having 3 to 30 carbon atoms, and the substituent R 31 The substituents which may be possessed by the crosslinkable group are the same as those exemplified in the substituent group Z in the polymer of the present embodiment, and the preferred substituents are also the same. The same also applies to the substituents which these substituents may further possess.

[0243] The compound represented by the formula (10A) is more preferably a compound represented by the following general formulas (10A-1) to (10A-3).

[0244] [ka]

[0245] (In formulas (10A-1) to (10A-3), Xa 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 , Za 2 has the same meaning as in equation (10). R 33 represents a hydrogen atom or a substituent. 33 may be the same or different. g11', h11' and j11' each independently represents an integer of 0 to 5. When g11', h11', and j11' are 2 or more, multiple Xa 1 , Ya 1 , Za 1 may be the same or different.)

[0246] In each of the above formulas (10A-1) to (10A-3), a partial structure in which one of the three benzene rings is bonded to the central pyridine ring, pyrimidine ring, or triazine ring can be regarded as partial structure A, and R bonded to the benzene ring constituting partial structure A can be regarded as a partial structure A. 33 is R in formula (10A). 31 This applies.

[0247] The compound represented by the formula (10B) is preferably a compound represented by the following formula (10B-1).

[0248] [ka]

[0249] (In formula (10B-1), A, Xb 1 , Yb 1 , Zb 1 , Yb 2 , Zb 2 , q13 and r13 have the same meanings as in formula (10B). p12', q12' and r12' each independently represents an integer of 0 to 5. If p12', q12', or r12' is 2 or more, multiple Xb 1 , Yb 1 , Zb 1 may be the same or different. q15 and r15 each independently is 4 or 5. R 33 is a hydrogen atom or a substituent. In formula (10B-1), 33 may be the same or different.)

[0250] R in the formulas (10A-1) to (10A-3) and (10B-1) 33 is a substituent, and R 33 When R is a substituent, it may further have the following substituents: 31 The same is true for

[0251] [Molecular weight] The molecular weight of the low molecular weight compound of this embodiment is usually 5,000 or less, preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less, and is usually 300 or more, preferably 350 or more, and more preferably 400 or more. Since the low molecular weight compound of this embodiment contains the required partial structure A, the molecular weight is usually the above-mentioned lower limit or more.

[0252] [Specific example] Specific examples of the low molecular weight compound of this embodiment are shown below. The low molecular weight compound of this embodiment is not limited to these.

[0253] [ka]

[0254] [ka]

[0255] [ka]

[0256] [Light-emitting dopants] The material containing partial structure A, which is a low molecular weight compound contained in the light-emitting layer according to one embodiment of the present invention, is also preferably a light-emitting dopant. The light-emitting dopant is preferably a compound represented by the following formula (40). The following formula (40) represents a compound in which the ring HA in the partial structure A represented by the above formula (31) is a triazine ring, Ar 0 corresponds to the pyridine ring. R in formula (40) 44 is an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group in which two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are linked together, n1 is 2, and the other Ar 0 is R 44 It is.

[0257] [ka]

[0258] In the above formula (40), R 41 , R 42 , R 43are each independently an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl 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 a substituent. R 41 , R 42 , R 43 When multiple are present, they may be the same or different. R 41 If there are multiple, adjacent R 41 may be bonded to each other to form a ring. 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.

[0259] R 44 are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl 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 2 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms. These groups may further have a substituent. R 44 When multiple are present, they may be the same or different. L 1 represents an organic ligand, and m40 is an integer of 1 to 3.

[0260] R 41 ~R 44are each independently, from the viewpoint of durability, more preferably an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an arylamino group having 6 to 20 carbon atoms, a (hetero)aryl group having 3 to 30 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms, even more preferably an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms, and even more preferably an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R 41 ~R 44 The substituent which may further be possessed by is preferably a substituent selected from the above-mentioned substituent group Z. If a40 is 2 or more, two adjacent R 41 may be bonded to each other to form a ring.

[0261] R 41 There are multiple adjacent R 41 Examples of the ring formed by bonding with each other include fluorene, naphthalene, dibenzothiophene, and dibenzofuran. From the viewpoint of stability, fluorene is particularly preferable. From the viewpoint of increasing the emission wavelength, adjacent R 41 are preferably bonded to each other to form a ring.

[0262] In addition, from the viewpoint of not making the emission wavelength longer, 41 are preferably not bonded to each other to form a ring. That is, in the formula (40), a40 is 1, or a40 is 2 or more and adjacent R 41 It is preferred that there are no rings bonded to each other.

[0263] In view of ease of production, a40 is preferably 0, and in view of enhanced durability and solubility, a40 is preferably 1 or 2, and more preferably 1. In view of ease of production, b40 is preferably 0, and in view of enhanced solubility, a40 is preferably 1. Since there are many highly electron-accepting structures containing a triazine ring, and the LUMO is more stabilized, m40 is preferably 2 or 3, and more preferably 3.

[0264] L 1 is an organic ligand, and is not particularly limited, but is preferably a monovalent bidentate ligand, and more preferably is selected from the following chemical formulas. In the following chemical formulas, the dashed lines represent coordinate bonds. Two organic ligands L 1 When present, the organic ligand L 1 may have different structures. Also, when m40 is 3, L 1 does not exist. When m40 in formula (40) is less than 3, L 1 has at least one structure selected from the group consisting of the following formulas (3), (4), and (5).

[0265] [ka]

[0266] In the above formulas (3), (4), and (5), R 49 , R 50 is R in the formula (40). 41 That is, R 41 The substituents are selected from the same group as those selected for R, and preferred examples are also the same, and R may further have a substituent. 49 , R 50 When multiple are present, they may be the same or different.

[0267] R 51 ~R 53 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with a fluorine atom, a phenyl group which may be substituted with an alkyl group having 1 to 20 carbon atoms, or a halogen atom.

[0268] g is an integer from 0 to 4. h is an integer from 0 to 4.

[0269] Ring B 40 is a pyridine ring, a pyrimidine ring, an imidazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, an azatriphenylene ring, a carboline ring, a benzothiazole ring, or a benzoxazole ring. 40 may further have a substituent.

[0270] R 49 , R 50 , ring B 40 The substituent which may further be possessed by is preferably a substituent selected from the above-mentioned substituent group Z. More preferred R 49 , R 50 are each independently an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 20 carbon atoms. Here, the aryl group having 6 to 30 carbon atoms is a monocyclic ring, a condensed bicyclic ring, a condensed tricyclic ring, or a group in which a plurality of monocyclic rings, condensed bicyclic rings, or condensed tricyclic rings are linked together.

[0271] g and h are preferably 0 in terms of ease of production, and are preferably 1 or 2, and more preferably 1, in terms of enhancing solubility.

[0272] R 51 ~R 53 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with a fluorine atom, a phenyl group which may be substituted with an alkyl group having 1 to 20 carbon atoms, or a halogen atom, and preferably, R 51 and R 53 is a methyl group or a t-butyl group, and R 52 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a phenyl group.

[0273] Ring B 40 From the viewpoint of durability, is preferably a pyridine ring, a pyrimidine ring, or an imidazole ring, and more preferably a pyridine ring. Ring B 40From the viewpoints of durability and enhanced solubility, the above hydrogen atoms are preferably substituted with an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms. Ring B 40 From the viewpoint of ease of production, it is preferred that the hydrogen atoms on the above are not substituted. Ring B 40 Since the hydrogen atom above is likely to generate excitons when used as an organic electroluminescent device, it is preferable that the hydrogen atom be substituted with a phenyl group or naphthyl group which may have a substituent, in order to improve the luminous efficiency. The substituent which the phenyl group or naphthyl group may have is preferably a substituent selected from the above-mentioned substituent group Z.

[0274] Ring B 40 is preferably a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, an azatriphenylene ring, or a carboline ring in terms of increasing luminous efficiency since excitons are easily generated on the assist dopant. Among these, a quinoline ring, an isoquinoline ring, or a quinazoline ring is more preferable in terms of durability and red light emission. More preferred 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 which may be substituted with an alkyl group having 1 to 20 carbon atoms. Here, the aryl group having 6 to 20 carbon atoms is a monocyclic ring, a condensed two-ring ring, a condensed three-ring ring, or a group in which a plurality of monocyclic rings, a condensed two-ring ring, or a condensed three-ring ring are linked together.

[0275] The compound represented by formula (40), which is an emitting dopant contained in the emitting layer according to one embodiment of the present invention, is R 44 is a phenyl group which may have a substituent, that is, a compound represented by the following formula (40-1) is preferred.

[0276] [ka]

[0277] In the above formula, R 41 , R 42 , R 43 , a40, b40, c40, L 1 , m40 is R in formula (40) 41 , R 42 , R 43 , a40, b40, c40, L 1 , and m40, respectively. R 45 is R 43 is synonymous with R 43 and R 45 may be the same or different. R 43 , R 45 When multiple are present, they may be the same or different. d40 is an integer from 0 to 5.

[0278] R 43 , R 45 From the viewpoint of durability, is preferably an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 30 carbon atoms, more preferably an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms, and even more preferably an alkyl group having 1 to 20 carbon atoms or an aralkyl group having 7 to 40 carbon atoms. R 43 , R 45 The substituent which may further be possessed by is preferably a substituent selected from the above-mentioned substituent group Z.

[0279] From the viewpoint of ease of production, c40 and d40 are preferably 0, and from the viewpoint of enhancing durability and solubility, they are preferably 1 or 2, and more preferably 1. From the viewpoint of ease of production, b40 is preferably 0, and from the viewpoint of enhancing solubility, they are preferably 1.

[0280] In the light-emitting dopant represented by formula (40) contained in the light-emitting layer according to one embodiment of the present invention, a40 is 2 or more, and adjacent R 41A structure in which the fluorene ring is formed by bonding to each other is preferred. Among these, a compound represented by the following formula (40-2) is preferred.

[0281] [ka]

[0282] In the above formula, R 42 ~R 44 , b40, c40, L 1 , m40 is R in formula (40) 42 ~R 44 , b40, c40, L 1 , and m40, respectively. R 54 ~R 56 is a substituent. 54 ~R 56 When multiple are present, they may be the same or different. i40 is an integer between 0 and 4.

[0283] R 54 is R 51 When R is a phenyl group, 51 R is a substituent which substitutes on R, and is preferably a substituent selected from the above-mentioned substituent group Z. 54 R is more preferably an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 20 carbon atoms. Here, the aromatic hydrocarbon group having 6 to 30 carbon atoms is a monocyclic ring, a condensed ring having 2 to 4 rings, or a group in which a plurality of monocyclic rings or a condensed ring having 2 to 4 rings are linked together. 54 is more preferably an alkyl group having 1 to 20 carbon atoms, and even more preferably an alkyl group having 1 to 8 carbon atoms.

[0284] R 55 , R 56 is R 41 Part of or R 41 R when it is a methyl group 41R is preferably a substituent which is independently selected from an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may be substituted with 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 which may be substituted with an alkoxy group having 1 to 20 carbon atoms. Here, the aromatic hydrocarbon group having 6 to 30 carbon atoms is a monocyclic ring, a condensed ring having 2 to 4 rings, or a group in which a plurality of monocyclic rings or a condensed ring having 2 to 4 rings are linked together. 55 , R 56 is more preferably an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 or 12 carbon atoms which may be substituted with an alkyl group having 1 to 20 carbon atoms, and even more preferably an alkyl group having 1 to 8 carbon atoms, or an aromatic hydrocarbon group having 6 carbon atoms which may be substituted with 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.

[0285] R 54 ~R 56 Specific preferred examples of the alkyl group in include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an isopropyl group, an isobutyl group, an isopentyl group, a t-butyl group, a cyclohexyl group, and a 2-ethylhexyl group.

[0286] R 54 ~R 56 Specific examples of preferred aromatic hydrocarbon groups in include monovalent groups such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, a fluoranthene ring, a biphenyl group, and a terphenyl group.

[0287] R 54 ~R 56 Specific preferred examples of the alkoxy group in include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a hexyloxy group, a cyclohexyloxy group, and an octadecyloxy group.

[0288] The compound serving as the light-emitting dopant represented by formula (40-1) contained in the light-emitting layer according to one embodiment of the present invention is more preferably a compound represented by the following formula (40-3).

[0289] [ka]

[0290] In the above formula, R 42 , R 43 , R 45 , b40, c40, d40, L 1 , m40 is R in formula (40-1) 42 , R 43 , R 45 , b40, c40, d40, L 1 , and m40, respectively. R 54 ~R 56 , i40 is R in formula (40-2) 54 ~R 56 , and i40, respectively.

[0291] Preferred specific examples of the compound represented by formula (40) which is to be used as an emitting dopant in the emitting layer, which is one embodiment of the present invention other than those shown in the Examples, are shown below, but the present invention is not limited thereto.

[0292] [ka]

[0293] [ka]

[0294] [ka]

[0295] [Hole transport layer] The hole transport layer of the organic electroluminescent device of the present invention (hereinafter sometimes referred to as the "hole transport layer of this embodiment") preferably contains the above-mentioned polymer of this embodiment as a partial structure A-containing material. The hole transport layer of this embodiment may contain one type of the polymer of this embodiment, or may contain two or more types in any combination and in any ratio.

[0296] The content of the polymer of this embodiment in the hole transport layer of this embodiment is usually 1 to 100% by weight, preferably 5 to 100% by weight, and more preferably 10 to 100% by weight. The above range is preferable because 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.

[0297] When the polymer of this embodiment does not account for 100% by weight in the hole transport layer of this embodiment, examples of components constituting the hole transport layer of this embodiment include hole transport compounds described below.

[0298] Since the organic electroluminescent device can be easily produced, the polymer of the present embodiment is preferably used for the hole transport layer of the present embodiment formed by a wet film formation method. The method of forming the hole transport layer by the wet film formation method will be described later.

[0299] [Hole transport layer forming composition] The composition for forming a hole transport layer for forming the hole transport layer of the present embodiment by a wet film formation method contains the polymer of the present embodiment. The composition for forming a hole transport layer of the present embodiment may contain one type of the polymer, or may contain two or more types of the polymer in any combination and in any ratio.

[0300] [Polymer content] The content of the polymer in the composition for forming a hole transport layer of the present embodiment is usually 0.01 to 70% by weight, preferably 0.1 to 60% by weight, and more preferably 0.5 to 50% by weight. Within the above range, defects are unlikely to occur in the formed hole transport layer, and unevenness in the film thickness is unlikely to occur, which is preferable. The composition for forming a hole transport layer of the present embodiment may contain a solvent and the like in addition to the polymer.

[0301] [solvent] The composition for forming a hole transport layer of the present embodiment usually contains a solvent. This solvent is preferably one that dissolves the above-mentioned polymer. Specifically, a solvent that dissolves the above-mentioned polymer at room temperature is suitable, usually at 0.05% by weight or more, preferably at 0.5% by weight or more, and more preferably at 1% by weight or more.

[0302] Specific examples of the solvent include organic solvents such as aromatic solvents, such as toluene, xylene, mesitylene, and cyclohexylbenzene; halogen-containing solvents, such as 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene; ether-based solvents, such as 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, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole; aliphatic ester-based solvents, such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; ester-based solvents, such as aromatic esters, such as 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-forming composition and hole transport layer-forming composition described below.

[0303] The solvent may be used alone or in any combination of two or more in any ratio.

[0304] Among these, the solvent contained in the composition for forming a hole transport layer of this embodiment is preferably a solvent having a surface tension at 20° C. of usually less than 40 dyn / cm, preferably 36 dyn / cm or less, and more preferably 33 dyn / cm or less.

[0305] When forming a coating film by a wet film-forming method using the composition for forming a hole transport layer of this embodiment and crosslinking the polymer to form a hole transport layer, it is preferable that the affinity between the solvent and the base is high. This is because the uniformity of the film quality greatly affects the uniformity and stability of the light emission of the organic electroluminescent device. Therefore, the composition for forming a hole transport layer used in the wet film-forming method is required to have a low surface tension so that a coating film with high leveling properties and uniformity can be formed. Therefore, by using a solvent having such a low surface tension, a uniform layer containing the polymer can be formed, and thus a uniform crosslinked layer can be formed, which is preferable.

[0306] Specific examples of the low surface tension solvent include the above-mentioned aromatic solvents such as toluene, xylene, mesitylene, cyclohexylbenzene, etc., aromatic ester solvents such as ethyl benzoate, etc., aromatic ether solvents such as anisole, etc., trifluoromethoxyanisole, pentafluoromethoxybenzene, 3-(trifluoromethyl)anisole, ethyl(pentafluorobenzoate), etc.

[0307] On the other hand, the solvent contained in the composition for forming a hole transport layer of this embodiment is preferably one having a vapor pressure of usually 10 mmHg or less, preferably 5 mmHg or less, and usually 0.1 mmHg or more at 25° C. By using such a solvent, it is possible to prepare a composition for forming a hole transport layer that is suitable for the process of producing a hole transport layer by a wet film formation method and that is suited to the properties of the polymer of this embodiment.

[0308] In order to obtain a more uniform film, it is preferable that the solvent evaporates at an appropriate rate from the liquid film immediately after the film formation. Therefore, as described above, the boiling point of the solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 350°C or lower, preferably 300°C or lower, more preferably 280°C or lower. Specific examples of such solvents include the above-mentioned aromatic solvents such as mesitylene and cyclohexylbenzene, aromatic ether solvents, and aromatic ester solvents.

[0309] Moisture may cause performance degradation of organic electroluminescent devices, particularly promoting a decrease in luminance during continuous operation. Therefore, in order to reduce the amount of moisture remaining during wet film formation as much as possible, among the above solvents, those having a water solubility of 1% by weight or less at 25° C. are preferred, and those having a water solubility of 0.1% by weight or less are more preferred.

[0310] The content of the solvent contained in the composition for forming a hole transport layer of the present embodiment is usually 10% by weight or more, preferably 30% by weight or more, and particularly preferably 50% by weight or more. By making the content of the solvent equal to or more than the above lower limit, the flatness and uniformity of the layer to be formed can be improved.

[0311] [Electron-accepting compounds] The composition for forming a hole transport layer of the present embodiment may further contain an electron accepting compound from the viewpoint of reducing resistance. The electron-accepting compound is preferably a compound having an oxidizing power and an ability to accept one electron from the polymer. Specifically, a compound having an electron affinity of 4 eV or more is preferable, and a compound having an electron affinity of 5 eV or more is more preferable.

[0312] Examples of such electron-accepting compounds include one or more compounds selected from the group consisting of triarylboron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids.

[0313] Specific examples include onium salts substituted with organic groups, such as 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate and triphenylsulfonium tetrafluoroborate (WO 2005 / 089024), (WO 2017 / 164268); high-valent inorganic compounds such as iron(III) chloride (JP 11-251067 A) and ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris(pentafluorophenyl)borane (JP 2003-31365 A); fullerene derivatives, and iodine.

[0314] The composition for forming a hole transport layer of the present embodiment may contain one type of the above-mentioned electron accepting compound alone, or may contain two or more types in any combination and ratio.

[0315] When the composition for forming a hole transport layer of this embodiment contains an electron accepting compound, the content of the electron accepting compound is usually 0.0005% by weight or more, preferably 0.001% by weight or more, and usually 20% by weight or less, preferably 10% by weight or less. The ratio of the electron accepting compound to the above polymer in the composition for forming a hole transport layer is usually 0.5% by weight or more, preferably 1% by weight or more, more preferably 3% by weight or more, and usually 80% by weight or less, preferably 60% by weight or less, and more preferably 40% by weight or less.

[0316] When the content of the electron-accepting compound in the composition for forming a hole transport layer is equal to or more than the lower limit, the electron acceptor accepts electrons from the polymer, and the resistance of the formed hole transport layer is reduced, which is preferable.When the content of the electron-accepting compound in the composition for forming a hole transport layer is equal to or less than the upper limit, the formed hole transport layer is less likely to have defects and is less likely to have uneven thickness, which is preferable.

[0317] [Cation radical compounds] The composition for forming a hole transport layer of the present embodiment may further contain a cation radical compound. The cation radical compound is preferably an ionic compound consisting of a cation radical, which is a chemical species obtained by removing one electron from a hole transporting compound, and a counter anion. However, when the cation radical is derived from a hole transporting polymer compound, the cation radical has a structure in which one electron is removed from a repeating unit of the polymer compound.

[0318] The cation radical is preferably a chemical species obtained by removing one electron from a hole transporting compound described below. A chemical species obtained by removing one electron from a compound preferred as a hole transporting compound is preferable in terms of amorphousness, visible light transmittance, heat resistance, solubility, etc.

[0319] Here, the cation radical compound can be generated by mixing a hole transporting compound described below with the electron accepting compound described above. That is, by mixing the hole transporting compound with the electron accepting compound, electrons are transferred from the hole transporting compound to the electron accepting compound, and a cation ion compound consisting of a cation radical of the hole transporting compound and a counter anion is generated.

[0320] When the composition for forming a hole transport layer of the present embodiment contains a cation radical compound, the content of the cation radical compound in the composition for forming a hole transport layer is usually 0.0005% by weight or more, preferably 0.001% by weight or more, and usually 40% by weight or less, preferably 20% by weight or less. When the content of the cation radical compound is equal to or more than the lower limit, the resistance of the formed hole transport layer is reduced, which is preferable. When the content of the cation radical compound is equal to or less than the upper limit, the formed hole transport layer is less likely to have defects and is less likely to have uneven thickness, which is preferable.

[0321] In addition to the above components, the composition for forming a hole transport layer of the present embodiment may contain components contained in the composition for forming a hole injection layer or the composition for forming a hole transport layer described below in the amounts described below.

[0322] [Light-emitting layer] The light-emitting layer of the organic electroluminescent device of the present invention (hereinafter sometimes referred to as "the light-emitting layer of this embodiment") preferably contains the above-mentioned low molecular weight compound of this embodiment as a partial structure A-containing material. The light-emitting layer of this embodiment may contain one type of the low molecular weight compound of this embodiment, or may contain two or more types in any combination and in any ratio.

[0323] The light-emitting layer of this embodiment contains at least the low molecular weight compound of this embodiment and a light-emitting material, and the low molecular weight compound of this embodiment functions as a host material for the light-emitting material. The light-emitting material may be a phosphorescent material or a fluorescent material.

[0324] The content of the light emitting material in the light emitting layer of the present invention is usually 0.1 to 50% by weight, preferably 0.2 to 40% by weight, and more preferably 0.5 to 35% by weight. When the content of the light emitting material is within the above range, high light emitting efficiency can be obtained.

[0325] The content of the low molecular weight compound of this embodiment in the light emitting layer of this embodiment is usually 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, as the content in materials other than the light emitting material, and usually 100% by weight or less, preferably 90% by weight or less, more preferably 80% by weight or less, particularly preferably 70% by weight or less. The above range is preferable because it is considered that the charge transportability of the light emitting layer of this embodiment is improved, the driving voltage is reduced, and the driving stability is improved.

[0326] When the light-emitting layer of this embodiment contains other components other than the light-emitting material and the low molecular compound of this embodiment, the other components include a charge transport material described later. The content of other components such as a charge transport material described later in the light-emitting layer of this embodiment is usually 0% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more, particularly preferably 30% by weight, and usually 95% by weight or less, preferably 90% by weight or less, more preferably 80% by weight or less, particularly preferably 70% by weight or less, as the content in materials other than the light-emitting material. If it is within the above range, it is preferable because it is considered that the carrier balance of electrons and holes in the light-emitting layer is good, the charge transportability is improved, the voltage is reduced, and the driving stability is improved.

[0327] Since the organic electroluminescent device can be easily manufactured, the low molecular weight compound of the present embodiment is preferably used in the light emitting layer of the present embodiment formed by a wet film formation method. The method of forming the light emitting layer by the wet film formation method will be described later.

[0328] [Composition for forming light-emitting layer] The composition for forming the light-emitting layer of this embodiment by a wet film-forming method contains the low molecular weight compound of this embodiment. The composition for forming the light-emitting layer of this embodiment may contain one type of the low molecular weight compound, or may contain two or more types of the low molecular weight compound in any combination and in any ratio.

[0329] [Low molecular weight compound content] The total content of solids such as the low molecular weight compound, the light emitting material, the charge transport material, etc. in the composition for forming the light emitting layer of this embodiment is usually 0.01 to 70% by weight, preferably 0.1 to 60% by weight, and more preferably 0.5 to 50% by weight. Within the above range, defects are unlikely to occur in the formed light-emitting layer, and unevenness in the film thickness is unlikely to occur, which is preferable. The composition for forming a light-emitting layer of the present embodiment may contain a solvent and the like in addition to the above-mentioned components such as the low molecular weight compound, the light-emitting material, and the charge transport material.

[0330] [solvent] The composition for forming a light-emitting layer of the present embodiment usually contains a solvent.

[0331] The solvent may be selected from the same solvents contained in the composition for forming a hole transport layer. The properties required for the solvent are also the same, and the preferred solvents are also the same.

[0332] The amount of the solvent used may be any amount as long as it does not significantly impair the effects of the present invention; however, the content in the composition for forming the light-emitting layer is preferably 1 mass % or more, more preferably 10 mass % or more, particularly preferably 50 mass % or more, and is preferably 99.99 mass % or less, more preferably 99.9 mass % or less, particularly preferably 99 mass % or less.

[0333] [Phosphorescent layer] When the light-emitting layer of the present embodiment is a phosphorescent light-emitting layer containing a phosphorescent material as the light-emitting material, the following materials are preferable as the phosphorescent material.

[0334] <Phosphorescent materials> The phosphorescent material is a material that emits light from an excited triplet state. Representative examples of the phosphorescent material include metal complex compounds containing Ir, Pt, Eu, etc., and the material preferably has a structure containing a metal complex.

[0335] Among metal complexes, examples of phosphorescent organometallic complexes that emit light via a triplet state include Werner-type complexes or organometallic complex compounds containing a metal selected from Groups 7 to 11 of the long-form periodic table (hereinafter, unless otherwise specified, the term "periodic table" refers to the long-form periodic table) as a central metal. As such phosphorescent materials, a compound represented by formula (201) or a compound represented by the following formula (205) is preferred, and a compound represented by the following formula (201) is more preferred.

[0336] [Compound represented by formula (201)] [ka]

[0337] In formula (201), ring A1 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A2 represents an aromatic heterocyclic structure which may have a substituent. R 201 , R 202 are each independently a structure represented by formula (202). "*" represents the bonding site with ring A1 or ring A2. R 201 , R 202 may be the same or different. R 201 , R 202 When there are multiple of each, they may be the same or different. Ar 201 , Ar 203 each independently represents an aromatic hydrocarbon structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent. Ar 202 represents an aromatic hydrocarbon structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. The substituents bonded to ring A1, the substituents bonded to ring A2, or the substituents bonded to ring A1 and the substituents bonded to ring A2 may be bonded to each other to form a ring. B 201 -L 200 -B 202 represents an anionic bidentate ligand. 201 and B. 202 each independently represents a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may be atoms constituting a ring. 200 is a single bond or B 201 and B. 202 Represents an atomic group that, together with B, constitutes a bidentate ligand. 201 -L 200 -B 202 When multiple are present, they may be the same or different. i1 and i2 each independently represent an integer of 0 to 12. i3 is Ar 202is an integer greater than or equal to 0, up to the number that can be substituted for it. j1 is Ar 201 is an integer greater than or equal to 0, up to the number that can be substituted for it. k1 and k2 each independently represent an integer of 0 or more, which is the upper limit of the number of substitutions that can be made on ring A1 and ring A2. m1 is an integer from 1 to 3.

[0338] Unless otherwise specified, the above-mentioned substituent is preferably a group selected from the following substituent group Z'.

[0339] <Substituent group Z´> Alkyl group: preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 8 carbon atoms, particularly preferably an alkyl group having 1 to 6 carbon atoms. 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. Aryloxy group: preferably an aryloxy group having 6 to 20 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, even more preferably an aryloxy group having 6 to 12 carbon atoms, particularly preferably an aryloxy group having 6 carbon atoms. Heteroaryloxy group: preferably a heteroaryloxy group having 3 to 20 carbon atoms, more preferably a heteroaryloxy group having 3 to 12 carbon atoms. Alkylamino group: preferably an alkylamino group having 1 to 20 carbon atoms, more preferably an alkylamino group having 1 to 12 carbon atoms. Arylamino group: preferably an arylamino group having 6 to 36 carbon atoms, more preferably an arylamino group having 6 to 24 carbon atoms. Aralkyl group: preferably an aralkyl group having 7 to 40 carbon atoms, more preferably an aralkyl group having 7 to 18 carbon atoms, and even more preferably an aralkyl group having 7 to 12 carbon atoms. Heteroaralkyl group: preferably a heteroaralkyl group having 4 to 40 carbon atoms, more preferably a heteroaralkyl group having 4 to 18 carbon atoms. Alkenyl group: preferably an alkenyl group having 2 to 20 carbon atoms, more preferably an alkenyl group having 2 to 12 carbon atoms, even more preferably an alkenyl group having 2 to 8 carbon atoms, particularly preferably an alkenyl group having 2 to 6 carbon atoms. Alkynyl group: preferably an alkynyl group having 2 to 20 carbon atoms, more preferably an alkynyl group having 2 to 12 carbon atoms. Aryl group: preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 24 carbon atoms, still more preferably an aryl group having 6 to 18 carbon atoms, particularly preferably an aryl group having 6 to 14 carbon atoms. Heteroaryl group: preferably a heteroaryl group having 3 to 30 carbon atoms, more preferably a heteroaryl group having 3 to 24 carbon atoms, even more preferably a heteroaryl group having 3 to 18 carbon atoms, particularly preferably a heteroaryl group having 3 to 14 carbon atoms. Alkylsilyl group: preferably an alkylsilyl group having an alkyl group with 1 to 20 carbon atoms, more preferably an alkylsilyl group having an alkyl group with 1 to 12 carbon atoms. Arylsilyl group: preferably an arylsilyl group having 6 to 20 carbon atoms in the aryl group, more preferably an arylsilyl group having 6 to 14 carbon atoms in the aryl group. Alkylcarbonyl group: preferably an alkylcarbonyl group having 2 to 20 carbon atoms Arylcarbonyl group: preferably an arylcarbonyl group having 7 to 20 carbon atoms The above substituents have one or more hydrogen atoms replaced with fluorine atoms, or one or more hydrogen atoms replaced with deuterium atoms. Be It may be possible. Unless otherwise specified, an aryl group is an aromatic hydrocarbon group, and a heteroaryl group is an aromatic heterocyclic group. Hydrogen atom, deuterium atom, fluorine atom, cyano group, or -SF5

[0340] (Preferred Groups in Substituent Group Z') Among the above-mentioned substituent group Z', Preferred are an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkylsilyl group, an arylsilyl group, a group in which one or more hydrogen atoms of these groups are replaced with a fluorine atom, a fluorine atom, a cyano group, and -SF5. More preferred are an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, a group in which one or more hydrogen atoms of these groups are replaced with a fluorine atom, a fluorine atom, a cyano group, and -SF5. More preferred are an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, and a heteroaryl group. Particularly preferred are an alkyl group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, and a heteroaryl group. Most preferred are an alkyl group, an arylamino group, an aralkyl group, an aryl group and a heteroaryl group.

[0341] (Substituent for Z') These substituent groups Z' may further have a substituent selected from the substituent group Z' as a substituent. The preferred groups, more preferred groups, further more preferred groups, particularly preferred groups, and most preferred groups of the substituents that may be had are the same as the preferred groups in the substituent group Z'.

[0342] <Ring A1> Ring A1 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent.

[0343] The aromatic hydrocarbon ring of ring A1 is preferably an aromatic hydrocarbon ring having a carbon number of 6 to 30. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an acenaphthene ring, a fluoranthene ring, or a fluorene ring is preferred. The aromatic heterocycle of ring A1 is preferably an aromatic heterocycle having 3 to 30 carbon atoms containing a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom, and more preferably a furan ring, a benzofuran ring, a thiophene ring, or a benzothiophene ring. Ring A1 is more preferably a benzene ring, a naphthalene ring, or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, and most preferably a benzene ring.

[0344] <Ring A2> Ring A2 represents an aromatic heterocyclic structure which may have a substituent.

[0345] The aromatic heterocycle of ring A2 is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specific examples of the ring include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, and a phenanthridine ring. More preferred are a pyridine ring, a pyrazine ring, a pyrimidine ring, an imidazole ring, a benzothiazole ring, a benzoxazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, and a quinazoline ring. More preferred are a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, and a quinazoline ring. Most preferred are a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, a quinoxaline ring, and a quinazoline ring.

[0346] (Combination of Ring A1 and Ring A2) Preferred combinations of ring A1 and ring A2, expressed as (ring A1-ring A2), include (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-imidazole ring), and (benzene ring-benzothiazole ring).

[0347] (Substituents of Ring A1 and Ring A2) The substituents which the ring A1 and the ring A2 may have can be arbitrarily selected, but are preferably one or more kinds of substituents selected from the above-mentioned substituent group Z'.

[0348] <Ar 201 , Ar 202 , Ar 203 > Ar 201 , Ar 203 each independently represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent. Ar 202 represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent.

[0349] (Ar 201 , Ar 202 , Ar 203 (aromatic hydrocarbon ring) Ar 201 , Ar 202 , Ar 203 When any one of the above is an aromatic hydrocarbon structure which may have a substituent, the aromatic hydrocarbon structure is preferably an aromatic hydrocarbon ring having a carbon number of 6 to 30. Specific examples include a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, more preferably a benzene ring, a naphthalene ring, and a fluorene ring, and most preferably a benzene ring.

[0350] (9,9' positions of fluorene) Ar 201 , Ar 202 , Ar 203 When any one of the above is a fluorene ring which may have a substituent, the 9-position and the 9'-position of the fluorene ring preferably have a substituent or are bonded to an adjacent structure.

[0351] (o-, m-phenylene) Ar 201 , Ar 02or the like. When any of the above is a benzene ring which may have a substituent, it is preferable that at least one of the benzene rings is bonded to an adjacent structure at an ortho-position or a meta-position, and it is more preferable that at least one of the benzene rings is bonded to an adjacent structure at a meta-position.

[0352] (Ar 201 , Ar 202 , Ar 203 (aromatic heterocycle of Ar 201 , Ar 202 , Ar 203 is an aromatic heterocyclic structure which may have a substituent, the aromatic heterocyclic structure is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specific examples include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, a phenanthridine ring, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring, and more preferably a pyridine ring, a pyrimidine ring, a triazine ring, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring.

[0353] (N-position of carbazole) Ar 201 , Ar 202 , Ar 203 When any one of the groups is a carbazole ring which may have a substituent, the N-position of the carbazole ring preferably has a substituent or is bonded to an adjacent structure.

[0354] (Ar 202 aliphatic hydrocarbons) Ar 202 When is an aliphatic hydrocarbon structure which may have a substituent, it is an aliphatic hydrocarbon structure having a straight chain, branched chain, or cyclic structure, and preferably has 1 or more and 24 or less carbon atoms, further preferably has 1 or more and 12 or less carbon atoms, and further preferably has 1 or more and 8 or less carbon atoms.

[0355] <i1、i2、i3、j1、k1、k2> (Preferable range of i1 and i2) i1 represents an integer of 0 to 12, preferably an integer of 1 to 12, further preferably an integer of 1 to 8, and further preferably an integer of 1 to 6. When it is within this range, improvements in solubility and charge transportability are expected.

[0356] (preferable range for i3) i3 preferably represents an integer of 0 to 5, more preferably 0 to 2, and even more preferably 0 or 1.

[0357] (Preferable range of j1) j1 preferably represents an integer of 0 to 2, and more preferably 0 or 1.

[0358] (Preferable ranges of k1 and k2) k1 and k2 each represent an integer of preferably 0 to 3, more preferably 1 to 3, even more preferably 1 or 2, and particularly preferably 1.

[0359] <Ar 201 , Ar 202 , Ar 203 Preferred substituents for Ar 201 , Ar 202 , Ar 203 The substituent that may be possessed by may be arbitrarily selected, but is preferably one or more kinds of substituents selected from the above-mentioned substituent group Z'. The preferred groups are also the same as those in the above-mentioned substituent group Z', but are more preferably a hydrogen atom, an alkyl group, or an aryl group, particularly preferably a hydrogen atom or an alkyl group, and most preferably unsubstituted (hydrogen atom).

[0360] <Preferred structure of formula (201)> Among the compounds represented by the above formula (201), a compound having the following structure is preferred.

[0361] (Phenylene linkage) A structure having groups linked to benzene rings. That is, Ar 201 is a benzene ring structure, i1 is 1 to 6, and at least one of the benzene rings is bonded to an adjacent structure at the ortho position or meta position. This structure is expected to improve the solubility and charge transport properties.

[0362] ((phenylene)-(aralkyl)-(alkyl)) A structure having an aromatic hydrocarbon group or aromatic heterocyclic group to which an alkyl group or an aralkyl group is bonded in ring A1 or ring A2. That is, Ar 201 is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, i1 is 1 to 6, Ar 202 is an aliphatic hydrocarbon structure, i2 is 1 to 12, preferably 3 to 8, Ar 203 is a benzene ring structure, and i3 is 0 or 1. Preferably, Ar 201 is the aromatic hydrocarbon structure, more preferably a structure in which 1 to 5 benzene rings are linked together, and even more preferably a structure in which there is one benzene ring. This structure is expected to improve the solubility and charge transport properties.

[0363] (Dendron) A structure in which a dendron is bonded to ring A1 or ring A2. For example, Ar, Ar 202 is a benzene ring structure, Ar 203 has a biphenyl or terphenyl structure, i1 and i2 are 1 to 6, i3 is 2, and j is 2. This structure is expected to improve the solubility and charge transport properties.

[0364] 201 -L 200 -B 202 > B 201 -L 200 -B 202 represents an anionic bidentate ligand. 201 and B. 202 ​each independently represents a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may be atoms constituting a ring. 200 is a single bond or B 201 and B. 202 Represents an atomic group that, together with B, constitutes a bidentate ligand. 201 -L 200 -B 202 When multiple are present, they may be the same or different.

[0365] B 201 -L 200 -B 202 The structure represented by the formula (203) or (204) is preferably a structure represented by the formula (203) or (204) below.

[0366] [ka]

[0367] (In formula (203), R 211 , R 212 , R 213 represents a substituent.)

[0368] [ka]

[0369] (In formula (204), ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom which may have a substituent. Ring B3 is preferably a pyridine ring.)

[0370] <Preferred phosphorescent material represented by formula (201)> The phosphorescent material represented by formula (201) is not particularly limited, but specific examples include the following structures: In the following, "Ph" represents a "phenyl group" and "Me" represents a "methyl group."

[0371] [ka]

[0372] [ka]

[0373] [ka]

[0374] [ka]

[0375] [ka]

[0376] [Compound represented by formula (205)] [ka]

[0377] In formula (205), M 2 represents a metal. T represents a carbon atom or a nitrogen atom. R 92 ~R 95 each independently represents a substituent. However, when T is a nitrogen atom, R 94 and R 95 There isn't.

[0378] In formula (205), M 2 represents a metal. Specific examples include the metals mentioned above as metals selected from Groups 7 to 11 of the periodic table. Among these, preferred are ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold, and particularly preferred are divalent metals such as platinum and palladium.

[0379] In formula (205), R 92 and R 93each independently represents a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, an alkoxy group, an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group.

[0380] If T is a carbon atom, R 94 and R 95 are each independently R 92 and R 93 When T is a nitrogen atom, R 94 or R 95 does not exist. R 92 ~R 95 may further have a substituent. The substituent may be the same as those described above. R 92 ~R 5 Any two or more of the groups may be linked to each other to form a ring.

[0381] <Molecular weight of phosphorescent material> The molecular weight of the phosphorescent material is preferably not more than 5000, more preferably not more than 4000, particularly preferably not more than 3000, and is usually not less than 800, preferably not less than 1000, and more preferably not less than 1200. It is believed that by having the molecular weight within this range, the phosphorescent materials do not aggregate with each other and can be uniformly mixed with the charge transport material, thereby making it possible to obtain a light-emitting layer with high luminous efficiency.

[0382] The molecular weight of the phosphorescent material is preferably large in terms of high Tg, melting point, decomposition temperature, etc., excellent heat resistance of the phosphorescent material and the formed light-emitting layer, and resistance to deterioration of film quality due to gas generation, recrystallization, molecular migration, etc., and increase in impurity concentration due to thermal decomposition of the material, etc. On the other hand, the molecular weight of the phosphorescent material is preferably small in terms of ease of purification of the organic compound.

[0383] [Host material for phosphorescent layer] The light-emitting layer of this embodiment contains the low molecular weight compound of this embodiment as a host material. When the light-emitting layer is a phosphorescent light-emitting layer, it preferably contains the following materials as other host materials.

[0384] The host material of the light-emitting layer is a material having a skeleton with excellent charge transport properties, and is preferably selected from electron transport materials, hole transport materials, and bipolar materials capable of transporting both electrons and holes.

[0385] (Structure with excellent charge transport properties) Specific examples of skeletons having excellent charge transport properties include an aromatic structure, an aromatic amine structure, a triarylamine structure, a dibenzofuran structure, a naphthalene structure, a phenanthrene structure, a phthalocyanine structure, a porphyrin structure, a thiophene structure, a benzylphenyl structure, a fluorene structure, a quinacridone structure, a triphenylene structure, a carbazole structure, a pyrene structure, an anthracene structure, a phenanthroline structure, a quinoline structure, a pyridine structure, a pyrimidine structure, a triazine structure, an oxadiazole structure, and an imidazole structure.

[0386] (electron transport material) As the electron transporting material, from the viewpoint of a material having excellent electron transporting properties and a relatively stable structure, a compound having a pyridine structure, a pyrimidine structure, or a triazine structure is more preferable, and a compound having a pyrimidine structure or a triazine structure is further preferable.

[0387] (Hole transport material) The hole transport material is a compound having a structure with excellent hole transport properties. Among the central skeletons with excellent charge transport properties, a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure, or a pyrene structure is preferable as a structure with excellent hole transport properties, and a carbazole structure, a dibenzofuran structure, or a triarylamine structure is more preferable.

[0388] (3 or more condensed ring structures) The host material of the light-emitting layer preferably has a condensed ring structure of 3 or more rings, more preferably a compound having two or more condensed ring structures of 3 or more rings or a compound having at least one condensed ring of 5 or more rings. By using these compounds, the rigidity of the molecule increases, and it becomes easier to obtain the effect of suppressing the degree of molecular motion in response to heat. Furthermore, the condensed rings of 3 or more rings and the condensed rings of 5 or more rings preferably have an aromatic hydrocarbon ring or an aromatic heterocyclic ring in terms of charge transportability and durability of the material.

[0389] Specific examples of the condensed ring structure having three or more rings include anthracene structure, phenanthrene structure, pyrene structure, chrysene structure, naphthacene structure, triphenylene structure, fluorene structure, benzofluorene structure, indenofluorene structure, indolofluorene structure, carbazole structure, indenocarbazole structure, indolocarbazole structure, dibenzofuran structure, and dibenzothiophene structure. From the viewpoint of charge transportability and solubility, at least one selected from the group consisting of phenanthrene structure, fluorene structure, indenofluorene structure, carbazole structure, indenocarbazole structure, indolocarbazole structure, dibenzofuran structure, and dibenzothiophene structure is preferred. From the viewpoint of durability against charge, a carbazole structure or an indolocarbazole structure is more preferred.

[0390] From the viewpoint of durability of the organic electroluminescent device against electric charges, at least one of the host materials of the light-emitting layer is preferably a material having a pyrimidine skeleton or a triazine skeleton.

[0391] (Molecular weight range) The host material of the light-emitting layer is preferably a polymeric material from the viewpoint of excellent flexibility. The light-emitting layer formed using a material having excellent flexibility is preferable as the light-emitting layer of an organic electroluminescent element formed on a flexible substrate. When the host material contained in the light-emitting layer is a polymeric material, the molecular weight is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and even more preferably 10,000 to 100,000.

[0392] The host material of the light-emitting layer is preferably a low molecular weight material from the viewpoints of ease of synthesis and purification, ease of designing electron transport performance and hole transport performance, and ease of viscosity adjustment when dissolved in a solvent. When the host material contained in the light-emitting layer is a low molecular weight material, the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less, and is usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0393] [Fluorescent layer] When the light-emitting layer of the present embodiment is a fluorescent light-emitting layer, it is preferably a blue fluorescent light-emitting layer using the following blue fluorescent light-emitting material as the fluorescent light-emitting material.

[0394] <Blue fluorescent material> The light-emitting material for the blue fluorescent layer is not particularly limited, but a compound represented by the following formula (211) is preferable.

[0395] [ka]

[0396] In the above formula (211), Ar 241 represents an aromatic hydrocarbon condensed ring structure which may have a substituent. 242 , Ar 243 each independently represents an alkyl group which may have a substituent, an aromatic hydrocarbon group, or a group in which these are bonded. n41 is an integer of 1 to 4.

[0397] Ar 241 represents an aromatic hydrocarbon condensed ring structure having preferably 10 to 30 carbon atoms. Specific examples of the structure include a naphthalene ring, an acenaphthene ring, a fluorene ring, an anthracene ring, a phenanthene ring, and the like. hmmExamples of the ring include a fluoranthene ring, a pyrene ring, a tetracene ring, a chrysene ring, and a perylene ring. More preferred are aromatic hydrocarbon condensed ring structures having 12 to 20 carbon atoms. Specific examples of the ring include an acenaphthene ring, a fluorene ring, an anthracene ring, a phenanthene ring, and the like. hmm Examples of the ring include a fluoranthene ring, a pyrene ring, a tetracene ring, a chrysene ring, and a perylene ring. More preferred is an aromatic hydrocarbon condensed ring structure having a carbon number of 16 to 18. Specific examples of the structure include a fluoranthene ring, a pyrene ring, and a chrysene ring.

[0398] n41 is an integer of 1 to 4, preferably 1 to 3, more preferably 1 or 2, and most preferably 2.

[0399] (Ar 241 , Ar 242 , Ar 243 (Substituents of Ar 241 , Ar 242 , Ar 243 The substituent which may be possessed by is preferably a group selected from the above-mentioned substituent group Z', more preferably a hydrocarbon group included in the substituent group Z', and even more preferably a hydrocarbon group among the groups preferred as the substituent group Z'.

[0400] [Host material for blue fluorescent emitting layer] In the light-emitting layer of this embodiment, the low molecular weight compound of this embodiment is used as a host material for the light-emitting material. When a blue fluorescent light-emitting material is used, the following materials are preferable as other host materials.

[0401] The host material for the blue fluorescent emitting layer is not particularly limited, but a compound represented by the following formula (212) is preferable.

[0402] [ka]

[0403] In the above formula (212), R 241 , R 242are each independently a structure represented by the following formula (213). 243 R represents a substituent. 243 When there are a plurality of n43, they may be the same or different.

[0404] [ka]

[0405] In the above formula (213), Ar 244 , Ar 245 each independently represents an aromatic hydrocarbon structure which may have a substituent, or a heteroaromatic ring structure which may have a substituent. Ar 244 , Ar 245 When a plurality of are present, they may be the same or different. n44 is an integer of 1 to 5. n45 is an integer of 0 to 5.

[0406] Ar 244 is preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 30 carbon atoms and which may have a substituent, and more preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 12 carbon atoms and which may have a substituent.

[0407] Ar 245 is preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 30 carbon atoms and which may have a substituent, or an aromatic heterocyclic structure which is a fused ring having 6 to 30 carbon atoms and which may have a substituent, and is more preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 12 carbon atoms and which may have a substituent, or an aromatic heterocyclic structure which is a fused ring having 12 carbon atoms and which may have a substituent.

[0408] n44 is preferably an integer of 1 to 3, and more preferably 1 or 2. n45 is preferably an integer of 0 to 3, and more preferably 0 to 2.

[0409] (R 243 , Ar 244 , Ar245 (Substituents of The substituent R 243 and Ar 244 and Ar 245 The substituent which may be possessed by is preferably a group selected from the above-mentioned substituent group Z', more preferably a hydrocarbon group included in the substituent group Z', and even more preferably a hydrocarbon group among the groups preferred as the substituent group Z'.

[0410] (molecular weight) The molecular weight of the emitting material for the blue fluorescent emitting layer and its host material is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less, and is usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0411] [Organic electroluminescent element] The organic electroluminescent device of the present embodiment is 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 having a hole transport layer and a light-emitting layer adjacent to the hole transport layer, and is characterized in that 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 partial structure A-containing materials having the same partial structure A.

[0412] The preferred embodiments of the hole transport layer of this embodiment containing the partial structure A-containing material and the light emitting layer of this embodiment containing the partial structure A-containing material are as described above.

[0413] As an example of the structure of the organic electroluminescent element of this embodiment, Fig. 1 shows a schematic diagram (cross section) of an example of the structure of an organic electroluminescent element 10. In Fig. 1, 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents a light-emitting layer, 6 represents a hole blocking layer, 7 represents an electron transport layer, 8 represents an electron injection layer, and 9 represents a cathode.

[0414] Hereinafter, an example of an embodiment of the layer structure of an organic electroluminescent device and a general method for forming the same will be described with reference to FIG.

[0415] In the present embodiment, the wet film formation method refers to a film formation method, i.e., a coating method, which employs a wet film formation method such as spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet printing, nozzle printing, screen printing, gravure printing, flexographic printing, etc., and then dries the coating film to form a film. Among these film formation methods, the spin coating, spray coating, inkjet printing, nozzle printing, etc. are preferred.

[0416] [substrate] The substrate 1 is a support for the organic electroluminescent element, and is usually made of a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, or the like. Of these, a glass plate or a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferred. The substrate is preferably made of a material with high gas barrier properties, since the organic electroluminescent element is less likely to deteriorate due to the outside air. For this reason, when a material with low gas barrier properties such as a synthetic resin substrate is used, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to increase the gas barrier properties.

[0417] [anode] The anode 2 has the function of injecting holes into the layers on the light-emitting layer 5 side. The anode 2 is usually composed of a metal such as aluminum, gold, silver, nickel, palladium, or platinum; a metal oxide such as indium and / or tin oxide; a metal halide such as copper iodide; carbon black, or a conductive polymer such as poly(3-methylthiophene), polypyrrole, or polyaniline.

[0418] The anode 2 is usually formed by a dry method such as sputtering or vacuum deposition. When forming the anode using fine metal particles such as silver, fine particles such as copper iodide, carbon black, fine conductive metal oxide particles, fine conductive polymer powder, etc., the anode can be formed by dispersing them in an appropriate binder resin solution and applying it onto a substrate. In the case of a conductive polymer, a thin film can be formed directly on the substrate by electrolytic polymerization, or the anode can be formed by applying the conductive polymer onto the substrate (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0419] The anode 2 usually has a single-layer structure, but may have a laminated structure as appropriate. When the anode 2 has a laminated structure, a different conductive material may be laminated on the first anode layer.

[0420] The thickness of the anode 2 may be determined according to the required transparency and material. When particularly high transparency is required, a thickness that provides a visible light transmittance of 60% or more is preferable, and a thickness that provides a visible light transmittance of 80% or more is more preferable. The thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. When transparency is not required, the thickness of the anode 2 may be arbitrarily determined according to the required strength, and in this case, the anode 2 may have the same thickness as the substrate.

[0421] When another layer is formed on the surface of the anode 2, it is preferable to perform a treatment with ultraviolet light / ozone, oxygen plasma, argon plasma, or the like before the film formation to remove impurities on the anode 2 and to adjust the ionization potential to improve the hole injection property.

[0422] [Hole injection layer] A layer having the function of transporting holes from the anode 2 side to the light-emitting layer 5 side is usually called a hole injection transport layer or a hole transport layer. When there are two or more layers having the function of transporting holes from the anode 2 side to the light-emitting layer 5 side, the layer closer to the anode side may be called a hole injection layer 3. It is preferable to form the hole injection layer 3 in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5 side. When the hole injection layer 3 is formed, the hole injection layer 3 is usually formed on the anode 2.

[0423] The thickness of the hole injection layer 3 is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[0424] The hole injection layer may be formed by a vacuum deposition method or a wet film formation method, but is preferably formed by a wet film formation method in terms of excellent film formability.

[0425] The hole injection layer 3 preferably contains a hole transporting compound, more preferably contains a hole transporting compound and an electron accepting compound, and further preferably contains a cation radical compound, particularly preferably contains a cation radical compound and a hole transporting compound.

[0426] A general method for forming a hole injection layer will be described below. In the organic electroluminescent device of the present embodiment, the hole injection layer is preferably formed by a wet film formation method using the composition for organic electroluminescent devices.

[0427] <Hole transport compound> The hole injection layer forming composition usually contains a hole transporting compound that will become the hole injection layer 3. In the case of a wet film forming method, the hole injection layer forming composition usually further contains a solvent. The hole injection layer forming composition preferably has high hole transporting properties and can efficiently transport injected holes. For this reason, it is preferable that the hole injection layer forming composition has high hole mobility and is less likely to generate impurities that become traps during production or use. It is also preferable that the composition has excellent stability, low ionization potential, and high transparency to visible light. In particular, when the hole injection layer 3 is in contact with the light emitting layer 5, it is preferable that the composition does not quench the light emission from the light emitting layer 5 or does not form an exciplex with the light emitting layer 5 to reduce the light emitting efficiency.

[0428] The hole transport compound is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV from the viewpoint of the charge injection barrier from the anode 2 to the hole injection layer 3. Examples of the hole transport compound include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which a tertiary amine is linked via a fluorene group, hydrazone compounds, silazane compounds, and quinacridone compounds.

[0429] Among the above-mentioned exemplary compounds, aromatic amine compounds are preferred from the viewpoint of amorphousness and visible light transmittance, and aromatic tertiary amine compounds are particularly preferred. The aromatic tertiary amine compounds are compounds having an aromatic tertiary amine structure, and also include compounds having a group derived from an aromatic tertiary amine.

[0430] The type of aromatic tertiary amine compound is not particularly limited, but it is preferable to use a polymer compound (polymerized compound having a series of repeating units) having a weight-average molecular weight of 1,000 or more and 1,000,000 or less, since uniform light emission is easily obtained due to the surface smoothing effect.

[0431] It is preferable that the hole injection layer 3 contains the above-mentioned electron accepting compound or the above-mentioned cation radical compound, since the conductivity of the hole injection layer can be improved by oxidation of the hole transport compound.

[0432] Cation radical compounds derived from polymer compounds such as PEDOT / PSS (Adv. Mater., 2000, Vol. 12, p. 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, Vol. 94, p. 7716) are also produced by oxidative polymerization (dehydrogenative polymerization).

[0433] The oxidative polymerization referred to here is a method in which a monomer is chemically or electrochemically oxidized in an acidic solution using peroxodisulfate or the like. In the case of this oxidative polymerization (dehydrogenative polymerization), the monomer is oxidized to polymerize, and a cation radical is generated by removing one electron from the repeating unit of the polymer, with the anion derived from the acidic solution as the counter anion.

[0434] <Formation of hole injection layer by wet film formation method> When the hole injection layer 3 is formed by a wet film formation method, a material for the hole injection layer 3 is usually mixed with a soluble solvent (solvent for the hole injection layer) to prepare a composition for film formation (composition for forming a hole injection layer), and this composition for forming a hole injection layer is applied onto a layer corresponding to the lower layer of the hole injection layer 3 (usually, the anode 2) to form a film, and then dried to form the film.

[0435] The concentration of the hole transporting compound in the composition for forming the hole injection layer is arbitrary as long as it does not significantly impair the effects of the present invention, but in terms of the uniformity of the film thickness, the lower the concentration, the more preferable, and in terms of preventing defects from occurring in the hole injection layer, the higher the concentration. Specifically, the concentration is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, particularly preferably 0.5% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less, and particularly preferably 50% by weight or less.

[0436] Examples of the solvent include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

[0437] Examples of the ether solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA), and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

[0438] Examples of the ester solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

[0439] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, and 1,4-diisopropylbenzene. , M ethylnaphthalene and the like.

[0440] Examples of the amide solvent include N,N-dimethylformamide and N,N-dimethylacetamide. In addition, dimethyl sulfoxide and the like can also be used.

[0441] The formation of the hole injection layer 3 by a wet film formation method is usually carried out by preparing a composition for forming the hole injection layer, applying the composition onto a layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2) and drying the composition. After the hole injection layer 3 is formed, the coating film is usually dried by heating, drying under reduced pressure, or the like.

[0442] <Formation of hole injection layer by vacuum deposition method> When forming the hole injection layer 3 by the vacuum deposition method, one or more of the constituent materials of the hole injection layer 3 (such as the above-mentioned hole transport compound and electron accepting compound) are usually placed in a crucible installed in a vacuum chamber (when two or more materials are used, each is usually placed in a separate crucible), and the inside of the vacuum chamber is vacuumed at 1000° C. with a vacuum pump. -4 After evacuating to about 10 Pa, the crucible is heated (when two or more types of materials are used, usually each crucible is heated) and the materials in the crucible are evaporated while controlling the amount of evaporation (when two or more types of materials are used, usually each material is evaporated while controlling the amount of evaporation independently), forming a hole injection layer 3 on an anode 2 on a substrate 1 placed opposite the crucible. When two or more types of materials are used, a mixture of those materials can be placed in a crucible and heated to evaporate to form a hole injection layer.

[0443] The degree of vacuum during deposition is not limited as long as it does not significantly impair the effects of the present invention. -6 Torr (0.13×10 -4 Pa) or above, 9.0×10 -6 Torr (12.0 × 10 -4 The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The deposition temperature during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is preferably 10° C. or more and 50° C. or less. The hole injection layer 3 may be crosslinked in the same manner as the hole transport layer 4 described below.

[0444] [Hole transport layer] The hole transport layer 4 is a layer that transports holes from the anode 2 side to the light emitting layer 5 side. The hole transport layer 4 of this embodiment preferably contains the polymer of this embodiment as the partial structure A-containing material. The hole transport layer 4 is usually formed between the anode 2 and the light emitting layer 5. When the above-mentioned hole injection layer 3 is present, the hole transport layer 4 is formed between the hole injection layer 3 and the light emitting layer 5.

[0445] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0446] The hole transport layer 4 may be formed by a vacuum deposition method or a wet film formation method, but is preferably formed by a wet film formation method in terms of excellent film formability.

[0447] A general method for forming a hole transport layer will be described below. The hole transport layer of the present embodiment is preferably formed by a wet film formation method using the above-mentioned composition for forming a hole transport layer.

[0448] The hole transport layer 4 usually contains a hole transport compound. The hole transport compound contained in the hole transport layer 4 is preferably the polymer of the present embodiment described above, or a crosslinked polymer of the polymer when the polymer has a crosslinkable group. In addition to the above polymer, the hole transport compound may be, preferably, an aromatic diamine containing two or more tertiary amines and having two or more condensed aromatic rings substituted with nitrogen atoms, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (JP Patent Publication No. 5-234681), or an aromatic amine compound having a starburst structure, such as 4,4',4''-tris(1-naphthylphenylamino)triphenylamine (J. Lumin ., vol. 72-74, p. 985, 1997), aromatic amine compounds consisting of triphenylamine tetramers (Chem. Commun., p. 2175, 1996), spiro compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, vol. 91, p. 209, 1997), carbazole derivatives such as 4,4'-N,N'-dicarbazole biphenyl, etc. Also, polyvinyl carbazole, polyvinyl triphenylamine (JP Patent Publication 7-53953 A), polyarylene ether sulfone containing tetraphenyl benzidine (Polym. Adv. Tech., vol. 7, p. 33, 1996), etc. may be included.

[0449] <Formation of hole transport layer by wet film formation method> When the hole transport layer 4 is formed by a wet film formation method, it is usually formed using a composition for forming a hole transport layer instead of the composition for forming a hole injection layer, in the same manner as when the above-mentioned hole injection layer 3 is formed by a wet film formation method.

[0450] When the hole transport layer 4 is formed by a wet film formation method, the composition for forming a hole transport layer usually further contains a solvent. The solvent used in the composition for forming a hole transport layer may be the same as the solvent used in the composition for forming a hole injection layer described above. The concentration of the hole transporting compound in the composition for forming a hole transport layer can be in the same range as the concentration of the hole transporting compound in the composition for forming a hole injection layer. The hole transport layer 4 can be formed by a wet film formation method similar to the film formation method for the hole injection layer 3 described above.

[0451] <Formation of hole transport layer by vacuum deposition method> When the hole transport layer 4 is formed by the vacuum deposition method, it can be formed in the same manner as when the hole injection layer 3 is formed by the vacuum deposition method, using the material of the hole transport layer 4 instead of the material of the hole injection layer 3. The film formation conditions such as the degree of vacuum, deposition rate, and temperature during deposition can be the same as those during the vacuum deposition of the hole injection layer 3.

[0452] [Light-emitting layer] The light-emitting layer 5 is a layer that is excited by the recombination of holes injected from the anode 2 and electrons injected from the cathode 9 when an electric field is applied between the pair of electrodes, and thus emits light. The light-emitting layer 5 is a layer 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.

[0453] The thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention, but a thicker thickness is preferable in terms of preventing defects from occurring in the film. On the other hand, a thinner thickness is preferable in terms of facilitating a low driving voltage. For this reason, the thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and usually preferably 200 nm or less, more preferably 100 nm or less.

[0454] The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material) and preferably contains a material having charge transport properties (charge transport material). The light-emitting layer of this embodiment contains at least a light-emitting material and a material containing partial structure A, which is preferably a low molecular weight compound of this embodiment.

[0455] Common light-emitting materials and methods for forming a light-emitting layer are described below. In the organic electroluminescent device of this embodiment, the light-emitting layer is preferably formed by a wet film-forming method using the above-mentioned composition for forming a light-emitting layer.

[0456] <Light-emitting materials> The light-emitting material is not particularly limited as long as it emits light at a desired emission wavelength and does not impair the effects of the present invention, and any known light-emitting material can be used. The light-emitting material may be a fluorescent material or a phosphorescent material, but a material with good luminous efficiency is preferred, and a phosphorescent material is preferred from the viewpoint of internal quantum efficiency.

[0457] Examples of the fluorescent material include the following materials.

[0458] Examples of fluorescent light-emitting materials that emit blue light (blue fluorescent light-emitting materials) include naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis(2-phenylethenyl)benzene, and derivatives thereof.

[0459] Examples of fluorescent materials that emit green light (green fluorescent materials) include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al(C9H6NO)3.

[0460] Examples of fluorescent light-emitting materials that give yellow light emission (yellow fluorescent light-emitting materials) include rubrene and perimidon derivatives.

[0461] Examples of fluorescent materials that emit red light (red fluorescent materials) include DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, and azabenzothioxanthene.

[0462] Examples of phosphorescent materials include organometallic complexes containing a metal selected from Groups 7 to 11 of the long-form periodic table. Preferred examples of metals selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

[0463] As the ligand of the organometallic complex, a ligand in which a (hetero)aryl group is linked to pyridine, pyrazole, phenanthroline, etc., such as a (hetero)arylpyridine ligand or a (hetero)arylpyrazole ligand, is preferred, and a phenylpyridine ligand or a phenylpyrazole ligand is particularly preferred. Here, the (hetero)aryl represents an aryl group or a heteroaryl group.

[0464] Specific examples of preferred phosphorescent materials include phenylpyridine complexes such as tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, tris(2-phenylpyridine)osmium, and tris(2-phenylpyridine)rhenium; and porphyrin complexes such as octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, and octaphenylpalladium porphyrin.

[0465] Polymer-based light-emitting materials include polyfluorene-based materials such as poly(9,9-dioctylfluorene-2,7-diyl), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)], and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(1,4-benzo-2{2,1'-3}-triazole)]; poly[2-methoxy-5-(2- workman Examples of suitable polyphenylenevinylene-based materials include polyphenylenevinylene such as (1,4-phenylenevinylene) and (2,4-phenylenevinylene).

[0466] <Charge transport material> The charge transporting material is a material that has a positive charge (hole) or negative charge (electron) transporting property. The charge transporting material is not particularly limited as long as it does not impair the effects of the present invention, and known charge transporting materials can be used.

[0467] The charge transporting material may be a compound that has been used in the light emitting layer of an organic electroluminescent device, and is preferably a compound that has been used as a host material in the light emitting layer.

[0468] Specific examples of charge transporting materials other than the low molecular weight compound of this embodiment include aromatic amine compounds including the polymer of this embodiment, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which a tertiary amine is linked via a fluorene group, hydrazone compounds, silazane compounds, silanamine compounds, phosphamine compounds, and quinacridone compounds, which are exemplified as hole transporting compounds for the hole injection layer. Other examples include electron transporting compounds such as anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, phenanthroline compounds, oxadiazole compounds, and silole compounds.

[0469] Further, for example, aromatic diamines containing two or more tertiary amines, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, in which two or more condensed aromatic rings are substituted with nitrogen atoms (JP Patent Publication No. 5-234681), aromatic amine compounds having a starburst structure, such as 4,4',4''-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., vol. 72-74, p. 985, 1997), triphenylamine, etc. Also preferably usable are the compounds exemplified as hole-transporting compounds for the hole-transporting layer, such as aromatic amine compounds consisting of a tetramer of fluorene (Chem. Commun., p. 2175, 1996), fluorene compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, vol. 91, p. 209, 1997), and carbazole compounds such as 4,4'-N,N'-dicarbazolebiphenyl.

[0470] Other examples include oxadiazole compounds such as 2-(4-biphenylyl)-5-(p-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD) and 2,5-bis(1-naphthyl)-1,3,4-oxadiazole (BND); silole compounds such as 2,5-bis(6'-(2',2''-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy); and phenanthroline compounds such as bathophenanthroline (BPhen) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, bathocuproine).

[0471] <Formation of light-emitting layer by wet film formation method> The method for forming the light-emitting layer 5 may be a vacuum deposition method or a wet film-forming method. The wet film-forming method is preferable because of its excellent film-forming properties, and the spin-coating method and the ink-jet method are more preferable. In particular, when the hole transport layer 4, which is the lower layer of the light-emitting layer 5, is formed using the above-mentioned hole transport layer-forming composition, lamination by the wet film-forming method is easy, so that the wet film-forming method is preferably adopted. When the light-emitting layer 5 is formed by the wet film-forming method, it is usually formed by using the above-mentioned light-emitting layer-forming composition instead of the hole injection layer-forming composition in the same manner as when the above-mentioned hole injection layer is formed by the wet film-forming method.

[0472] The solvent can be removed after the wet film formation by heating or reducing pressure. In the heating method, a clean oven or a hot plate is preferable as a heating means for applying heat uniformly to the entire film.

[0473] The heating temperature in the heating step may be any temperature as long as it does not significantly impair the effects of the present invention. A higher temperature is preferable in terms of shortening the drying time, while a lower temperature is preferable in terms of minimizing damage to the material. heating The upper limit of the temperature is usually 250°C or lower, preferably 200°C or lower, and more preferably 150°C or lower. heating The lower limit of the temperature is usually 30° C. or higher, preferably 50° C. or higher, and more preferably 80° C. or higher. heating A temperature exceeding the upper limit is not preferred because the heat resistance of the charge transport material or phosphorescent material that is usually used is higher and decomposition or crystallization may occur. A heating temperature below the lower limit is not preferred because it takes a long time to remove the solvent. The heating time in the heating step is appropriately determined depending 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.

[0474] <Formation of light-emitting layer by vacuum deposition method> When forming the light-emitting layer 5 by the vacuum deposition method, one or more of the constituent materials of the light-emitting layer 5 (the above-mentioned light-emitting material, the low molecular compound of this embodiment, the charge transporting compound, etc.) are usually placed in a crucible installed in a vacuum container (when two or more materials are used, each is usually placed in a separate crucible), and the inside of the vacuum container is vacuumed for 10 minutes with a vacuum pump. -4 After evacuating to about 10 Pa, the crucible is heated (when two or more types of materials are used, usually each crucible is heated) and the materials in the crucible are evaporated while controlling the evaporation amount (when two or more types of materials are used, usually each material is evaporated while controlling the evaporation amount independently), forming the light-emitting layer 5 on the hole transport layer 4 placed opposite the crucible. When two or more types of materials are used, a mixture of those materials can also be placed in the crucible and heated to evaporate to form the light-emitting layer 5.

[0475] The degree of vacuum during deposition is not limited as long as it does not significantly impair the effects of the present invention. -6 Torr (0.13×10 -4 Pa) or above, 9.0×10 -6 Torr (12.0 × 10 -4 The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The deposition temperature during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is preferably 10° C. or more and 50° C. or less.

[0476] [Hole blocking layer] A hole blocking layer 6 may be provided between the light emitting layer 5 and the electron injection layer 8 described below. The hole blocking layer 6 is a layer laminated on the light emitting layer 5 so as to be in contact with the interface of the light emitting layer 5 on the cathode 9 side.

[0477] The hole-blocking layer 6 has a role of preventing holes migrating from the anode 2 from reaching the cathode 9, and a role of efficiently transporting electrons injected from the cathode 9 toward the light-emitting layer 5. Required physical properties of the material constituting the hole-blocking layer 6 include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1).

[0478] Examples of materials for the hole blocking layer 6 that satisfy these conditions include mixed ligand complexes such as bis(2-methyl-8-quinolinolato)(phenolato)aluminum and bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum; metal complexes such as bis(2-methyl-8-quinolinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolinolato)aluminum binuclear metal complex; styryl compounds such as distyrylbiphenyl derivatives (JP Patent Publication No. 11-242996); triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (JP Patent Publication No. 7-41759); and phenanthroline derivatives such as bathocuproine (JP Patent Publication No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at the 2-, 4- and 6-positions, as described in International Publication No. 2005 / 022962, are also preferred as materials for the hole blocking layer 6.

[0479] There is no limitation on the method for forming the hole blocking layer 6. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods. The thickness of the hole blocking layer 6 is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[0480] [Electron transport layer] The electron transport layer 7 is provided between the light emitting layer 5 and the electron injection layer 8 for the purpose of further improving the current efficiency of the device.

[0481] The electron transport layer 7 is made of a compound capable of efficiently transporting electrons injected from the cathode 9 between the electrodes to which an electric field is applied, toward the light emitting layer 5. The electron transporting compound used in the electron transport layer 7 is required to have a high efficiency of electron injection from the cathode 9 or the electron injection layer 8, a high electron mobility, and the ability to efficiently transport the injected electrons.

[0482] Specific examples of the electron transporting compound used in the electron transport layer include metal complexes such as aluminum complexes of 8-hydroxyquinoline (JP-A-59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (U.S. Pat. No. 5,645,948), quinoxaline compounds (JP-A-6-207169), phenanthroline derivatives (JP-A-5-331459), 2-t-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

[0483] The thickness of the electron transport layer 7 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0484] The electron transport layer 7 is formed by laminating it on the hole blocking layer 6 by the wet film formation method or the vacuum deposition method in the same manner as described above. Usually, the vacuum deposition method is used.

[0485] [Electron injection layer] The electron injection layer 8 plays a role of efficiently injecting electrons injected from the cathode 9 into the electron transport layer 7 or the light emitting layer 5 .

[0486] To efficiently inject electrons, the material forming the electron injection layer 8 is preferably a metal with a low work function. Examples of such a material include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. In this case, the thickness of the electron injection layer 8 is preferably generally 0.1 nm or more and 5 nm or less.

[0487] Further, as a material for forming the electron injection layer 8, an organic electron transport material, typified by a nitrogen-containing heterocyclic compound such as bathophenanthroline or a metal complex such as an aluminum complex of 8-hydroxyquinoline, doped with an alkali metal such as sodium, potassium, cesium, lithium or rubidium (described in JP-A-10-270171, JP-A-2002-100478, JP-A-2002-100482, etc.), is also preferable because it improves the electron injection and transport properties and makes it possible to achieve both excellent film quality. In this case, the film thickness of the electron injection layer 8 is in the range of usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

[0488] The electron injection layer 8 is formed by laminating it on the light-emitting layer 5 or on the hole blocking layer 6 or electron transport layer 7 thereon by a wet film formation method or a vacuum deposition method. The details of the wet film formation method are the same as those of the light-emitting layer described above.

[0489] [cathode] The cathode 9 plays a role of injecting electrons into the layer on the light-emitting layer 5 side (the electron injection layer 8 or the light-emitting layer 5, etc.).

[0490] The material of the cathode 9 can be the same as that of the anode 2. For efficient electron injection, it is preferable to use a metal with a low work function, such as tin, magnesium, indium, calcium, aluminum, silver, or an alloy thereof. Specific examples include low-work-function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

[0491] From the viewpoint of element stability, it is preferable to protect the cathode made of a metal having a low work function by laminating a metal layer having a high work function and stable against the atmosphere on the cathode 9. Examples of the metal to be laminated include aluminum, silver, copper, nickel, chromium, gold, platinum, and the like. The thickness of the cathode 9 is usually similar to that of the anode 2 .

[0492] [Other layers] The organic electroluminescent device of the present embodiment may further include other layers as long as the effects of the present invention are not significantly impaired. That is, any of the above-mentioned other layers may be included between the anode 2 and the cathode 9.

[0493] [Other element configurations] The organic electroluminescent device of this embodiment may have a structure opposite to that described above, that is, a cathode 9, an electron injection layer 8, an electron transport layer 7, a hole blocking layer 6, a light emitting layer 5, a hole transport layer 4, a hole injection layer 3, and an anode 2 laminated in this order on a substrate 1. The organic electroluminescent device of the present invention may also be provided between two substrates, at least one of which is highly transparent.

[0494] When the organic electroluminescent element of the present embodiment is applied to an organic electroluminescent device, it may be used as a single organic electroluminescent element, or may be used in a configuration in which a plurality of organic electroluminescent elements are arranged in an array, or may be used in a configuration in which anodes and cathodes are arranged in an XY matrix.

[0495] [Organic EL display device] The organic EL display device (organic electroluminescence element display device) of this embodiment uses the above-mentioned organic electroluminescence element. The type and structure of the organic EL display device of this embodiment are not particularly limited, and the organic EL display device can be assembled by a conventional method using the above-mentioned organic electroluminescence element. For example, the organic EL display device of the present invention can be formed by a method such as that described in "Organic EL Display" (Ohmsha, published on August 20, 2004, by Tokito Shizuo, Adachi Chihaya, and Murata Hideyuki).

[0496] [Organic EL lighting] The organic EL lighting (organic electroluminescence element lighting) of this embodiment uses the above-mentioned organic electroluminescence element. There are no particular limitations on the type or structure of the organic EL lighting of this embodiment, and it can be assembled in accordance with a conventional method using the above-mentioned organic electroluminescence element. Working Example

[0497] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples, and the present invention can be practiced with any modifications without departing from the gist of the present invention.

[0498] [Synthesis Example 1: Synthesis of polymer compound having partial structure A] <Synthesis of raw material monomers> [ka]

[0499] Under a nitrogen stream, 3-bromo-3'-nitro-biphenyl (14.1g, 50.5mmol), bis(pinacolato)diboron (17.1g, 60.6mmol), and potassium acetate (24.8g, 253.0mmol) were placed in a 1000ml flask and purged with nitrogen at room temperature. Then, 200ml of 1,4-dioxane was placed in the flask, and 1,1'-bis(diphenylphosphino)ferrocene-palladium(II)dichloride-dichloromethane [PdCl2(dppf)CH2Cl2] (1.24g, 1.52mmol) was added, and the mixture was reacted at 100°C for 8.5 hours. The reaction solution was filtered under reduced pressure, diluted with toluene, and crudely purified with activated clay. The crude product was further purified by column chromatography (developing solution: hexane / ethyl acetate = 80 / 20) to obtain compound 1 (16.3 g, yield 99.5%).

[0500] [ka]

[0501] Next, compound 1 (8.7 g, 26.76 mmol), 1-bromo-3-iodobenzene (7.95 g, 28.1 mmol), an aqueous potassium phosphate solution (2 M, 40.1 ml), toluene (80 ml), and ethanol (40 ml) were charged into a flask, and the system was thoroughly replaced with nitrogen and heated to 65°C. Bis(triphenylphosphine)palladium(II) dichloride (0.094 g, 0.134 mmol) was added thereto, and the mixture was stirred at 65° C. for 3 hours. Water was added to the reaction solution, and the mixture was extracted with toluene. The organic layer was dried over anhydrous magnesium sulfate and extracted with activated clay. To The crude product was purified by column chromatography (developing solution: hexane / methylene chloride=80 / 20) to obtain compound 2 (8.6 g, yield 90.5%).

[0502] [ka]

[0503] Under a nitrogen stream, 100 ml of dimethyl sulfate was added to a 300 ml flask. Hoki Cid, compound 2 (8.55 g, 24.14 mmol), bis(pinacolato)diboron (7.36 g, 28.97 mmol), and potassium acetate (7.1 g, 72.42 mmol) were added and stirred at 60° C. for 30 minutes. Then, 1,1'-bis(diphenylphosphino)ferrocene-palladium(II) dichloride-dichloromethane [PdCl2(dppf)CH2Cl2] (0.99 g, 1.21 mmol) was added and reacted at 85° C. for 4.0 hours. The reaction mixture was filtered under reduced pressure, and the filtrate was extracted with toluene, dried over anhydrous magnesium sulfate, and then extracted with activated clay. Coarse The crude product was further purified by column chromatography (developing solution: hexane / ethyl acetate=90 / 10) to obtain compound 3 (9.3 g, yield 96.0%).

[0504] [ka]

[0505] Next, compound 3 (9.3 g, 23.18 mmol), 1-bromo-4-iodobenzene (6.88 g, 24.33 mmol), an aqueous potassium phosphate solution (2 M, 34.8 ml), toluene (80 ml), and ethanol (40 ml) were charged into a flask, and the system was thoroughly replaced with nitrogen and heated to 65°C. Bis(triphenylphosphine)palladium(II) dichloride (0.081 g, 0.116 mmol) was added thereto and stirred at 65°C for 3.5 hours. Water was added to the reaction solution, and extraction was performed with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was purified by column chromatography (developing solution: hexane / methylene chloride = 75 / 25) to obtain compound 4 (8.7 g, yield 87.2%).

[0506] [ka]

[0507] Under a nitrogen stream, 100 ml of dimethyl sulfate was added to a 300 ml flask. Hoki Cid, compound 4 (8.7 g, 20.22 mmol), bis(pinacolato)diboron (6.2 g, 24.26 mmol), and potassium acetate (5.95 g, 60.66 mmol) were added and stirred at 60° C. for 30 minutes. Then, 1,1'-bis(diphenylphosphino)ferrocene-palladium(II) dichloride-dichloromethane [PdCl2(dppf)CH2Cl2] (0.83 g, 1.01 mmol) was added and reacted at 85° C. for 3.0 hours. The reaction mixture was filtered under reduced pressure, and the filtrate was extracted with toluene, dried over anhydrous magnesium sulfate, and then extracted with activated clay. Coarse The crude product was further purified by column chromatography (developing solution: hexane / methylene chloride=50 / 50) to obtain compound 5 (7.2 g, yield 75.0%).

[0508] [ka]

[0509] 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), an aqueous potassium phosphate solution (2 M, 23.0 ml), toluene (50 ml), and ethanol (25 ml) were charged into a flask, and the system was thoroughly replaced with nitrogen and heated to 65°C. Tetrakis(triphenylphosphine)palladium(0) (0.52 g, 0.45 mmol) was added thereto, and the mixture was stirred at 85° C. for 4.0 hours. The precipitated insoluble matter was filtered under reduced pressure, and the filtered product was washed by suspending it in 50 ml of methylene chloride and added dropwise to 200 ml of ethanol. The precipitate was filtered under reduced pressure and dried to obtain compound 6 (5.3 g, yield 61.2%).

[0510] [ka]

[0511] Under a nitrogen stream, 500 ml of tetrahydrofuran, 50 ml of ethanol, compound 6 (5.3 g, 9.10 mmol), and palladium / carbon (10%, approximately 55% wet with water, 0.72 g) were placed in a 1000 ml flask and stirred at 50° C. for 15 minutes. D Rhazine monohydrate (3.1 g) was added dropwise and the reaction was carried out at this temperature for 3 hours. The reaction mixture was filtered through water-wet Celite under reduced pressure, and the filtrate was concentrated to obtain Compound 7 (4.8 g, yield 95.1%).

[0512] [ka]

[0513] Compound 8 (8.0 g, 49 mmol), 1-bromo-1'-iodo-3,3'-biphenyl (17.7 g, 49 mmol), toluene 120 ml, ethanol 60 ml, and 2M potassium phosphate aqueous solution (62 ml) were placed in a 500 ml flask, and nitrogen bubbling was performed for 30 minutes. Tetrakis(triphenylphosphine)palladium(0) (1.43 g, 1.24 mmol) was added, and the mixture was heated and stirred at 90°C for 3 hours. The mixture was then cooled to room temperature, and water and toluene were added for separation and washing, after which the organic layer was dried over anhydrous magnesium sulfate. The solvent was then removed under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 9) to obtain 15.5 g of compound 9 as a colorless oil.

[0514] [ka]

[0515] In a 500 ml flask, compound 9 (15.5 g, 44 mmol), 3-aminophenylboronic acid monohydrate (6.4 g, 41 mmol), toluene 100 ml, ethanol 50 ml, and 2 M potassium phosphate aqueous solution (55 ml) were placed, and nitrogen bubbling was performed for 30 minutes. Tetrakis (triphenylphosphine) palladium (0) (1.3 g, 1.15 mmol) was added, and the mixture was heated and stirred at 90 ° C for 3.5 hours. After that, it was cooled to room temperature, and water and toluene were added and washed by separation, and the organic layer was dried with anhydrous magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate / hexane = 2 / 8) to obtain 7.8 g of compound 10 as a pale yellow starch syrup.

[0516] [ka]

[0517] In a 1 L flask, add 270 ml of toluene, 135 ml of ethanol, and 20.0 g (44.8 mmol) of compound 11. 5 -Bromo- 2 A solution containing 50.72 g (179.3 mmol) of iodotoluene and 2 M aqueous potassium phosphate solution (191 ml) was degassed under vacuum and replaced with nitrogen. The solution was heated under a nitrogen stream and stirred for 30 minutes. Then, 0.63 g (0.90 mmol) of bis(triphenylphosphine)palladium(II) dichloride was added and refluxed for 6 hours. Water was added to the reaction solution, which was then extracted with toluene and treated with anhydrous magnesium sulfate and activated clay. The toluene solution was heated under reflux, and the insoluble matter was filtered and recrystallized to obtain colorless solid compound 12 (yield: 14.2 g, 60.2%).

[0518] [ka]

[0519] Compound 14 was synthesized in the same manner as in the synthesis of compound 12, except that 1-bromo-4-iodobenzene was used instead of 5-bromo-2-iodotoluene.

[0520] <Synthesis of polymer compound (polymer 1) having partial structure A> [ka]

[0521] 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 charged, the system was thoroughly purged with nitrogen, and the system was heated to 60° C. (Solution A1). Separately, to a solution of tris(dibenzylideneacetone)dipalladium complex (86.0 mg, 0.09 mmol) in 14 ml of toluene was added [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (199.4 mg, 0.8 mmol), and the mixture was heated to 60° C. (Solution B1).

[0522] Solution B1 was added to solution A1 in a nitrogen stream, and the mixture was heated and refluxed for 1.0 hour. After confirming that compounds 7, 10, and 13 had disappeared, compound 14 (1.78 g, 3.5 mmol) was added. After heating and refluxing for 2 hours, bromobenzene (1.84 g, 11.7 mmol) was added, and the mixture was heated and refluxed for 1 hour. The reaction solution was allowed to cool, and then added dropwise to an ethanol / water (370 ml / 70 ml) solution to obtain an end-capped crude polymer. The end-capped crude polymer was dissolved in toluene and reprecipitated in acetone, and the precipitated polymer was filtered off. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated in ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain the target polymer 1 (2.5 g). The molecular weight of the obtained polymer 1 was as follows:

[0523] Weight average molecular weight (Mw)=20,600 Number average molecular weight (Mn)=15,260 Dispersity (Mw / Mn)=1.35

[0524] [Example 1] An organic electroluminescent device was fabricated in the following manner. A 70 nm thick indium tin oxide (ITO) transparent conductive film (manufactured by Sanyo Vacuum, sputtered film) was deposited on a glass substrate and patterned into 2 mm wide stripes using standard photolithography techniques and hydrochloric acid etching to form the anode. The substrate with the ITO pattern formed in this way was ultrasonically cleaned with a surfactant solution, rinsed with ultrapure water, ultrasonically cleaned with ultrapure water, and rinsed with ultrapure water, in that order, then dried with compressed air, and finally cleaned with ultraviolet ozone.

[0525] As a composition for forming a hole injection layer, 100 parts by weight of a hole transporting polymer compound having a repeating structure represented by the following formula (P-1) and 20 parts by weight of a compound represented by the following formula (HI-1) were weighed out and dissolved in ethyl benzoate to prepare a composition with a solid concentration of 3.0% by weight.

[0526] [ka]

[0527] This composition for forming a hole injection layer was spin-coated on the substrate in the atmosphere and dried on a hot plate in the atmosphere at 240° C. for 30 minutes to form a uniform thin film with a thickness of 40 nm, which was used as a hole injection layer.

[0528] Next, 100 parts by weight of a charge transporting polymer compound represented by the following formula (HT-1), which is Polymer 1 synthesized in Synthesis Example 1, was dissolved in cyclohexylbenzene to prepare a composition for forming a hole transport layer consisting of a 3.0 wt % solution. This composition for forming a hole transport layer was spin-coated in a nitrogen glove box onto the substrate on which the above-mentioned hole injection layer had been coated, and dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 40 nm, which was used as the hole transport layer.

[0529] [ka]

[0530] Subsequently, as materials for the light-emitting layer, 15 parts by weight of a compound represented by the following formula (H-1), 15 parts by weight of a compound represented by the following formula (H-2), 70 parts by weight of a compound represented by the following formula (H-3), and 20 parts by weight of a compound represented by the following formula (D-1) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solid concentration of 7.8% by weight as a composition for forming a light-emitting layer.

[0531] [ka]

[0532] [ka]

[0533] This composition for forming an emissive layer was spin-coated in a nitrogen glove box onto the substrate on which the hole transport layer had been coated, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 70 nm, which was used as the emissive layer.

[0534] The substrate on which the light-emitting layer had been formed was placed in a vacuum deposition apparatus, and the inside of the apparatus was heated to 2 × 10 -4 The pressure was evacuated until the pressure was below 1 Pa.

[0535] Next, a compound represented by the following formula (HB-1) and 8-hydroxyquinolinolatolithium were co-deposited on the light-emitting layer in a thickness ratio of 2:3 at a rate of 1 Å / sec by vacuum deposition to form a hole-blocking layer with a thickness of 30 nm.

[0536] [ka]

[0537] Next, a 2 mm wide striped shadow mask as a mask for cathode deposition was placed in close contact with the substrate so as to be perpendicular to the ITO stripes of the anode, and then placed in another vacuum deposition apparatus. Then, aluminum was heated in a molybdenum boat to form an aluminum layer having a thickness of 80 nm at a deposition rate of 1 to 8.6 Å / sec to form a cathode. In this manner, an organic electroluminescence device having a light-emitting area measuring 2 mm×2 mm was obtained.

[0538] [Comparative Example 1] An organic electroluminescent device was produced in the same manner as in Example 1, except that the material composition of the light-emitting layer was changed to a weight ratio of (H-4):(H-5):(H-3):(D-1)=15:15:70:20. (H-4) and (H-5) are represented by the following formulas.

[0539] [ka]

[0540] [Element evaluation] The organic electroluminescence devices obtained in Example 1 and Comparative Example 1 were subjected to a current of 10 mA / cm 2 The voltage when a current of 1000 was applied was measured, and the value obtained by subtracting the voltage of Comparative Example 1 from the voltage of Example 1 was taken as the relative voltage. In addition, the current luminous efficiency (cd / A) at that time was measured, and the relative current luminous efficiency of Example 1 when the current luminous efficiency of Comparative Example 1 was taken as 1 was taken as the relative luminous efficiency. In addition, these organic electroluminescent devices were driven at 40 mA / cm 2 The 15% luminance decay life (LT85) was measured, and the ratio (hereinafter referred to as "relative decay life") was calculated assuming that the 15% luminance decay life of Comparative Example 1 was 1. They are shown in Table 1.

[0541] From Table 1, it was found that the organic electroluminescent device of the present invention, which contains a compound having the same partial structure A represented by formula (TzP) in the hole transport layer and the light emitting layer, exhibits lower voltage and longer life. Here, the charge transporting polymer compound represented by formula (HT-1) used in Example 1 and the compound represented by formula (H-1) both have a structure in which four benzene rings are linked to triazine, and therefore have a high degree of commonality, which is also considered to contribute to the long life.

[0542] [Table 1]

[0543] [Example 2] An organic electroluminescent device was fabricated in the following manner. A 50 nm thick indium tin oxide (ITO) transparent conductive film (Geomatec, sputtered film) was deposited on a glass substrate and patterned into 2 mm wide stripes using standard photolithography and hydrochloric acid etching to form the anode. The substrate with the ITO pattern formed in this way was ultrasonically cleaned with a surfactant solution, rinsed with ultrapure water, ultrasonically cleaned with ultrapure water, and rinsed with ultrapure water, in that order, then dried with compressed air, and finally cleaned with ultraviolet ozone.

[0544] 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 a repeating structure represented by formula (P-1) used in Example 1 and 0.6 wt % of the compound represented by formula (HI-1) in ethyl benzoate.

[0545] This composition for forming a hole injection layer was spin-coated on the substrate in the atmosphere and dried on a hot plate in the atmosphere at 240° C. for 30 minutes to form a uniform thin film with a thickness of 40 nm, which was used as a hole injection layer.

[0546] Next, 100 parts by weight of a charge transporting polymer compound represented by the following formula (HT-2) was dissolved in cyclohexylbenzene to prepare a 3.0% by weight solution of a composition for forming a hole transport layer. This composition for forming a hole transport layer was spin-coated in a nitrogen glove box onto the substrate on which the above-mentioned hole injection layer had been coated, and then dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 40 nm, which was used as the hole transport layer.

[0547] [ka]

[0548] Subsequently, as materials for the light-emitting layer, 50 parts by weight of the compound represented by formula (H-1) used in Example 1, 50 parts by weight of the compound represented by formula (H-6) below, and 15 parts by weight of the compound represented by formula (D-1) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer.

[0549] [ka]

[0550] This composition for forming an emissive layer was spin-coated in a nitrogen glove box onto the substrate on which the hole transport layer had been coated, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 80 nm, which was used as the emissive layer.

[0551] The substrate on which the light-emitting layer had been formed was placed in a vacuum deposition apparatus, and the inside of the apparatus was heated to 2 × 10 -4 The pressure was evacuated until the pressure was below 1 Pa.

[0552] Next, a compound represented by the following formula (ET-1) and 8-hydroxyquinolinolatolithium were co-deposited on the light-emitting layer in a thickness ratio of 2:3 at a rate of 1 Å / sec by vacuum deposition to form a hole-blocking layer with a thickness of 30 nm.

[0553] [ka]

[0554] Next, a 2 mm wide striped shadow mask as a mask for cathode deposition was placed in close contact with the substrate so as to be perpendicular to the ITO stripes of the anode, and then placed in another vacuum deposition apparatus. Then, aluminum was heated in a molybdenum boat to form an aluminum layer having a thickness of 80 nm at a deposition rate of 1 to 8.6 Å / sec to form a cathode. In this manner, an organic electroluminescence device having a light-emitting area measuring 2 mm×2 mm was obtained.

[0555] [Comparative Example 2] 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, an organic electroluminescent device was produced in the same manner as in Example 1. (H-4) is the same as that shown in Comparative Example 1.

[0556] [Element evaluation] The organic electroluminescence devices obtained in Example 2 and Comparative Example 2 were energized at 1000 cd / m 2 The voltage and external quantum efficiency (EQE (%)) were measured when the device was driven to emit light at a luminance of 1000 Hz. The value obtained by subtracting the voltage of Comparative Example 2 from the voltage of Example 2 is shown in Table 2 as the relative voltage. The EQE of Example 2 is shown in Table 2 as a relative EQE when the EQE of Comparative Example 2 is taken as 1. In addition, to evaluate the operating life of the element, a current of 60 mA / cm was applied to this element. 2 The time it took for the luminance of the element to decrease to 90% of the initial luminance (LT90 (hr)) was measured, and the LT90 life of Example 2 was shown in Table 2 as a relative life when the LT90 of Comparative Example 2 was taken as 1.

[0557] From Table 2, it was found that the organic electroluminescent device of the present invention, which contains a compound having the same partial structure A represented by formula (TzP) in the hole transport layer and the light emitting layer, exhibits lower voltage and longer life.

[0558] [Table 2]

[0559] [Example 3] As materials for the light-emitting layer, 50 parts by weight of a compound represented by the following formula (H-7), 50 parts by weight of a compound represented by the following formula (H-8), and 15 parts by weight of the compound represented by the formula (D-1) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solid concentration of 5.0% by weight as a composition for forming a light-emitting layer. An element was produced in the same manner as in Example 2, except that:

[0560] [ka]

[0561] [Example 4] As materials for the light-emitting layer, 50 parts by weight of the compound represented by formula (H-1), 50 parts by weight of the compound represented by formula (H-8), and 15 parts by weight of the compound represented by formula (D-1) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer. An element was produced in the same manner as in Example 2, except that the materials were dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer.

[0562] [Comparative Example 3] As materials for the light-emitting layer, 50 parts by weight of the compound represented by formula (H-4), 50 parts by weight of the compound represented by formula (H-8), and 15 parts by weight of the compound represented by formula (D-1) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer. An element was produced in the same manner as in Example 2, except that the materials were dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer.

[0563] [Comparative Example 4] A device was prepared in the same manner as in Comparative Example 3, except that a charge transporting polymer compound represented by the following formula (HT-3) was used as the hole transporting layer material instead of the charge transporting polymer compound represented by the formula (HT-2).

[0564] [ka]

[0565] [Element evaluation] The organic electroluminescent devices obtained in Examples 3 and 4 and Comparative Examples 3 and 4 were energized at 1000 cd / m 2 The voltage and external quantum efficiency (EQE (%)) were measured when the device was driven to emit light at a luminance of 1000 Hz. The values ​​obtained by subtracting the voltage of Comparative Example 4 from the voltages of Examples 3, 4, and Comparative Example 3 are shown in Table 3 as relative voltages. The EQEs of Example 3, Example 4, and Comparative Example 3 are shown in Table 3 as relative EQEs when the EQE of Comparative Example 4 is taken as 1. In addition, to evaluate the operating life of the element, a current of 60 mA / cm was applied to this element. 2 A current density of 1000 mA was continuously applied to each of the elements, and the time (LT95 (hr)) until the luminance of the element decreased to 95% of the initial luminance was measured. The LT95 lifespans of Example 3, Example 4, and Comparative Example 3 were shown in Table 3 as relative lifespans when the LT95 of Comparative Example 4 was taken as 1.

[0566] From Table 3, it was found that the organic electroluminescent device of the present invention, which contains a compound having the same partial structure A represented by formula (TzP) in the hole transport layer and the light emitting layer, exhibits lower voltage and longer life.

[0567] [Table 3]

[0568] [Example 5] As materials for the light-emitting layer, 50 parts by weight of a compound represented by the following formula (H-9), 50 parts by weight of a compound represented by the above formula (H-6), and 15 parts by weight of a compound represented by the following formula (D-2) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solid concentration of 5.0% by weight as a composition for forming a light-emitting layer. An element was produced in the same manner as in Example 3.

[0569] [ka]

[0570] [Comparative Example 5] A device was produced in the same manner as in Example 4, except that the charge transporting polymer compound represented by the formula (HT-3) was used instead of the charge transporting polymer compound represented by the formula (HT-2) as the hole transport layer material, and 50 parts by weight of the compound represented by the formula (H-9), 50 parts by weight of the compound represented by the formula (H-6), and 15 parts by weight of the compound represented by the following formula (D-3) were weighed out as the light emitting layer materials and dissolved in cyclohexylbenzene to prepare a solution with a solid concentration of 5.0% by weight as a composition for forming a light emitting layer.

[0571] [ka]

[0572] [Element evaluation] The organic electroluminescence devices obtained in Example 5 and Comparative Example 5 were energized at 1000 cd / m 2 The voltage and external quantum efficiency (EQE (%)) were measured when the device was driven to emit light at a luminance of 1000 Hz. The value obtained by subtracting the voltage of Comparative Example 5 from the voltage of Example 5 is shown in Table 4 as a relative voltage. The EQE of Example 5 is shown in Table 4 as a relative EQE when the EQE of Comparative Example 5 is taken as 1. In addition, to evaluate the operating life of the element, a current of 60 mA / cm was applied to this element. 2 The time it took for the luminance of the element to decrease to 95% of the initial luminance (LT95 (hr)) was measured, and the LT95 life of Example 5 was shown as a relative life in Table 4 when the LT95 of Comparative Example 5 was taken as 1.

[0573] From Table 4, it was found that the organic electroluminescent device of the present invention, which contains a compound having the same partial structure A represented by formula (TzP) in the hole transport layer and the light emitting layer, exhibits lower voltage and longer life.

[0574] [Table 4]

[0575] [Example 6] A device was produced in the same manner as in Example 2, except that a charge transporting polymer compound represented by the following formula (HT-4) was used as the hole transport layer material instead of the charge transporting polymer compound represented by the above formula (HT-2), and that 50 parts by weight of a compound represented by the following formula (H-10), 25 parts by weight of a compound represented by the following formula (H-11), 25 parts by weight of a compound represented by the following formula (H-12), and 30 parts by weight of a compound represented by the following formula (D-4) were weighed out as materials for the light emitting layer, and dissolved in cyclohexylbenzene to prepare a solution with a solid concentration of 5.0% by weight as a composition for forming a light emitting layer.

[0576] [ka]

[0577] [Comparative Example 6] A device was prepared in the same manner as in Example 6, except that the charge transporting polymer compound represented by formula (HT-3) was used as the hole transporting layer material instead of the charge transporting polymer compound represented by formula (HT-4).

[0578] [Element evaluation] The organic electroluminescence devices obtained in Example 6 and Comparative Example 6 were energized at 1000 cd / m 2 The external quantum efficiency (EQE (%)) was determined when the device was caused to emit light at a luminance of 1. The EQE of Example 6 is shown in Table 5 as the relative EQE when the EQE of Comparative Example 6 is taken as 1. In addition, to evaluate the operating life of the element, a current of 15 mA / cm was applied to this element. 2 The time it took for the luminance of the element to decrease to 90% of the initial luminance (LT90 (hr)) was measured, and the LT90 life of Example 6 was shown as a relative life in Table 5 when the LT90 of Comparative Example 6 was taken as 1.

[0579] From Table 5, it was found that the organic electroluminescence device of the present invention, in which the hole transport layer and the light emitting layer contain a compound having the same partial structure A, exhibits a lower voltage and a longer life.

[0580] [Table 5]

[0581] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2020-027324 filed on February 20, 2020, the entirety of which is incorporated by reference. Explanation of symbols

[0582] 1 Board 2 Anode 3. Hole injection layer 4. Hole transport layer 5. Light-emitting layer 6 Hole Blocking Layer 7 Electron transport layer 8 Electron injection layer 9 Cathode 10 Organic electroluminescent device

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 includes a hole transport layer and a light emitting layer adjacent to the hole transport layer; an organic electroluminescence device in which 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 represented by the following formula (31), The partial structure A represented by the formula (31) is a structure represented by the following formula (35): The light-emitting layer contains a low-molecular-weight compound having the partial structure A, and the low-molecular-weight compound is a compound represented by any one of the following formulas (10A-1) to (10A-3) and having a molecular weight of 5,000 or less. 【Chemistry 1】 (In formula (31), Ring HA represents a monocyclic or 2-6 condensed ring aromatic heterocycle which may have a substituent. The benzene ring in the formula (31) may have a substituent. Ar ０ represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. n1 is 0 or Ar in the ring HA. ０ represents an integer equal to or less than the number that can be substituted. When n1 is 2 or more, a plurality of Ar ０ may be the same or different.) 【Chemistry 2】 (In formula (35), Ar ０ and n1 has the same meaning as in formula (31). The benzene ring in formula (35) may have a substituent. Each of X and Y independently represents a C atom or a N atom. When X and Y are C atoms, Ar ０ may be bonded.) 【Chemistry 3】 (In formulas (10A-1) to (10A-3), Xa 1 , Ya 1 , and Za 1 each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. Xa 2 , Ya 2 and Za 2 each independently represent a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. R 33 represents a hydrogen atom or a substituent. A plurality of R 33 s may be the same or different. g11', h11' and j11' each independently represents an integer of 0 to 5. When g11', h11', and j11' are 2 or more, the multiple Xa 1 s, Ya 1 s, and Za 1 s may be the same or different.

2. 2 . The organic electroluminescent device according to claim 1 , wherein at least one of the material having the partial structure A contained in the hole transport layer and the material having the partial structure A contained in the light emitting layer has two or more partial structures A.

3. The organic electroluminescent device according to claim 1 or 2, wherein in the partial structure represented by the formula (35), X and Y are N atoms.

4. 4. The organic electroluminescent device according to claim 1, wherein the material having the partial structure A contained in the hole transport layer is a polymer compound having a repeating unit represented by the following formula (1): 【Chemistry 4】 (In formula (1), A represents partial structure A. G represents an aromatic hydrocarbon group which may have a substituent, or a nitrogen atom. Ar ２ represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group. Ar ２０ represents a direct bond, a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together.

5. 5. The organic electroluminescent device according to claim 4, wherein the G is a group consisting of a benzene ring which may have a substituent, a fluorene ring which may have a substituent, or a spirofluorene ring which may have a substituent.

6. The organic electroluminescent device according to claim 4 , wherein the G is a N atom.

7. 7. The organic electroluminescent device according to claim 6, wherein the repeating unit represented by formula (1) is a repeating unit represented by any one of the following formulas (2)-1 to (2)-3: 【Chemistry 5】 (In formula (2)-1 to formula (2)-3, A has the same meaning as A in the above formula (1). Q is -C(R ５ ) (R ６ ) -, -N(R ７ )-or-C(R １１ ) (R １２ )-C(R １３ ) (R １４ )- represents. R １ ~R ４ each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aralkyl group which may have a substituent. R ５ ~R ７ and R １１ ~R １４ each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. a and b each independently represents an integer of 0 to 4. c1 to c5 each independently represents an integer of 0 to 3. However, at least one of c3 and c5 is 1 or more. d1 to d4 each independently represents an integer of 1 to 4. R １ , R ２ , R ３ , R ４ When there are a plurality of in the repeating unit, R １ , R ２ , R ３ , R ４ may be the same or different.)

8. -Ar in the formula (1) ２０ The organic electroluminescent device according to any one of claims 4 to 7, wherein -A is represented by the following formula (15): 【Chemistry 6】 (In formula (15), X and Y each independently represent a C atom or an N atom. The ring having X, Y and N corresponds to the ring HA in formula (31). Ar １ represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which two or more divalent aromatic hydrocarbon groups which may have a substituent are linked together. Ar ３ , Ar ４ each independently represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by linking two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. However, Ar １ , Ar ３ , Ar ４ In at least one of the above, the structure bonded to the ring HA is a benzene ring. * indicates the binding site with G.)

9. -Ar in the formula (1) ２０ 9. The organic electroluminescent device according to claim 8, wherein -A is represented by the following formula (16): 【Chemistry 7】 (In formula (16), X, Y and * are defined as in formula (15). The ring having X, Y and N corresponds to ring HA as in formula (15). Ar １ ' is a direct bond or in formula (15), １ This represents a residue in which the structure bonded to the ring HA is a benzene ring. Ar ３ ', Ar ４ ' is a hydrogen atom or ３ , Ar ４ The structure bonded to the ring HA of the formula (I) is a benzene ring.

10. 10. The organic electroluminescent device according to claim 4, wherein the material having the partial structure A contained in the hole transport layer further has a repeating unit represented by the following formula (3): 【Chemistry 8】 (In formula (3), Ar １３ represents an aromatic hydrocarbon group which does not contain the partial structure A and which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar １４ represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group.

11. An organic EL display device comprising the organic electroluminescent device according to any one of claims 1 to 10.

12. An organic electroluminescence (EL) lighting device comprising the organic electroluminescence device according to any one of claims 1 to 10.

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