polymer

Abstract

The present invention addresses the problem of providing: a polymer which has a high excited singlet energy level (S1) and a high excited triplet energy level (T1), prevents the quenching of light due to the energy transfer from a light-emitting material or a light-emitting exciton, and has a high luminous efficiency; and a composition for organic electroluminescent elements, which contains the polymer. The present invention relates to a polymer containing a repeating unit represented by formula (1).　The definition for each of the groups in formula (1) is as defined in the description.

Description

[Technical Field]

[0001] The present invention relates to polymers, and more particularly to polymers useful as charge transport materials for organic electroluminescent devices. Furthermore, the present invention relates to a composition for organic electroluminescent devices containing the polymer, an organic electroluminescent device including a layer formed using the composition, and an organic EL display device and organic EL lighting having the organic electroluminescent device. [Background technology]

[0002] Methods for forming the organic layer in organic electroluminescent devices include vacuum deposition and wet deposition. Vacuum deposition has the advantage of easy stacking, which improves charge injection from the anode and / or cathode and facilitates the containment of excitons in the light-emitting layer. On the other hand, wet deposition does not require a vacuum process, is easy to scale up to large areas, and has the advantage of easily forming layers containing multiple materials with various functions by using a coating solution that is a mixture of multiple materials with various functions.

[0003] However, because wet deposition methods make it difficult to create multilayer structures, they have inferior driving stability compared to devices made by vacuum deposition methods, and currently, with a few exceptions, they have not reached a practical level. Therefore, the development of charge-transporting polymers that can be laminated using wet film deposition methods is underway.

[0004] Patent documents 1 and 2 disclose hole-injection transportable materials having a structure in which a fluorene ring or a carbazole ring and a phenylene ring are bonded to the main chain of the polymer.

[0005] Patent Document 3 discloses polymers having triarylamine repeating units and polymers containing fluorene rings in the main chain. It also describes increasing the triplet energy of the polymer by generating twists in the polymer main chain by including substituted phenylene groups.

[0006] Patent Document 4 discloses a polymer having triarylamine and fluorene as its main chain, wherein a twist is generated by providing substituents on the phenylene group adjacent to the nitrogen atom. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2016-084370 [Patent Document 2] Japanese Patent Application Publication No. 2017-002287 [Patent Document 3] Japan Special Publication No. 2007-520858 [Patent Document 4] International Publication No. 2019 / 177175 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, through the inventors' research, it was found that the technologies disclosed in the above-mentioned patent documents each have the following problems.

[0009] The polymers described in Patent Documents 1 and 2 have a problem in that, because the main chain has a π-conjugated system, the excited singlet energy level (S1) and excited triplet energy level (T1) are low, and quenching occurs due to energy transfer from the luminescent material and excitons, resulting in a decrease in luminescence efficiency. Therefore, there is a need for charge transport materials with high S1 and T1 energy levels.

[0010] Patent Document 3 discloses a method for increasing the triplet energy of a polymer by generating twist through the inclusion of substituted phenylene groups, and provides an example of general formula (III). However, Patent Document 3 does not disclose a polymer that can solve the above problem. The same is true for Patent Document 4.

[0011] The present invention aims to provide a polymer having high singlet excitation energy level (S1) and triplet excitation energy level (T1), suppressing quenching due to energy transfer from a luminescent material and a luminescent exciton, and having high luminous efficiency, and a composition for an organic electroluminescent device containing the polymer.

Means for Solving the Problems

[0012] As a result of intensive studies, the present inventors have found that the above problems can be solved by using a polymer having a specific repeating unit, and have completed the present invention.

[0013] That is, the gist of the present invention resides in the following <1> to <17>. <1> A polymer containing a repeating unit represented by the following formula (1).

[0014]

Chemical formula

[0015] In formula (1), Ar 11 , 9 , 7 , 8 , 13 , 12 , 10 , , 8 , 1 represents a monovalent group in which a plurality of groups selected from a monovalent aromatic hydrocarbon group which may have a substituent, a monovalent aromatic heterocyclic group which may have a substituent, or a monovalent aromatic hydrocarbon group which may have a substituent and a monovalent aromatic heterocyclic group which may have a substituent are directly or via a linking group, Ar 2 and Ar 3 each independently represent a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have a substituent are directly or via a linking group linked in the main chain direction, X represents -C(R[[ID=​​​​​​​​​​​​​​​​​​Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R 1 , R 2 , R 5 , R 6 At least one of them is an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R 9 ~R 13 Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group. n represents an integer between 1 and 3. However, the two structures that constitute the main chain of the polymer and are directly bonded to the nitrogen atom of the main chain amine of formula (1) are both phenylene groups, which may have substituents. <2> In the above formula (1), Ar 3 Ar in the repeating unit that is adjacent to and joined 3 If the atom bonding with it is not the nitrogen atom of the main chain amine, then Ar 2 In the structure represented by , the structure bonded to the nitrogen atom of the main chain amine is a phenylene group without substituents. Ar 3 Ar in the repeating unit that is adjacent to and joined 3 If the atom that bonds with it is the nitrogen atom of the main chain amine, then Ar 2 In the structure represented by , the structure bonded to the nitrogen atom of the main chain amine is a phenylene group without substituents, and Ar 3 In the structure represented by Ar 3 At least one of the following conditions is met: the structure directly bonded to the nitrogen atom of the main chain amine in the repeating unit adjacent to it is a phenylene group without substituents. <1> The polymer described above. <3> The two structures in the main chain of the polymer that are bonded to the nitrogen atom of the main chain amine in formula (1) are unsubstituted phenylene groups. <1> or <2> The polymer described above. <4> The above equation (1) is expressed by the following equation (2)-1 or equation (2)-2, <1> ~ <3> A polymer as described in any one of the following.

[0016] [ka]

[0017] In equation (2)-1 or equation (2)-2, Ar 1 , R 1 ~R 6 X is the same as the definition in equation (1) above, R 20 ~R 23 Each of them independently, R 1 It is similar to this, g, h, and i each independently represent integers between 1 and 3. j and k each independently represent integers between 1 and 2. <5> Furthermore, it includes at least one of the repeating units represented by the following formula (3)-1 and the following formula (3)-2, <1> ~ <4> A polymer as described in any one of the following.

[0018] [ka]

[0019] In equation (3)-1 or equation (3)-2, Ar 4 In each repeating unit, independently, a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups, X 30 -C(R 37 )(R 38 )-,-N(R 39 )-, or -C(R 40 )(R 41 )-C(R 42 )(R43 )- represents, R 33 , R 34 , R 37 , R 38 , R 120 ~R 123 Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R 39 ~R 43 Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group. g 3 h 3 i 3 Each of these independently represents an integer between 1 and 3. j 3 , k 3 Each of these independently represents an integer between 1 and 2. <6> Ar 1 This is expressed by the following formula (A1): <1> ~ <5> A polymer as described in any one of the following.

[0020] [ka]

[0021] In formula (A1), Ar 6 and Ar 7 Each of these independently represents a divalent aromatic hydrocarbon group which may have substituents, a divalent aromatic heterocyclic group which may have substituents, or a divalent group in which multiple groups selected from a divalent aromatic hydrocarbon group which may have substituents and a divalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar 8This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar 9 represents a hydrogen atom or substituent, -* represents the bonding position with the nitrogen atom in formula (1) above. <7> Ar 4 This is expressed by the following formula (A2): <5> or <6> The polymer described above.

[0022] [ka]

[0023] In formula (A2), Ar 36 and Ar 37 Each independently represents a divalent aromatic hydrocarbon group which may have substituents, a heterocyclic aromatic group which may have substituents, or a divalent group in which multiple groups selected from a heterocyclic aromatic hydrocarbon group which may have substituents and a heterocyclic aromatic group which may have substituents are linked directly or via linking groups. Ar 38 This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar 39 represents a hydrogen atom or substituent, -* represents the bond position with the nitrogen atom in formula (3)-1 or formula (3)-2. <8> R 1 and R 2 Each of these independently represents an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. <1> ~ <7> A polymer as described in any one of the following. <9> The polymer has a crosslinkable group as a substituent. <1> ~ <8> A polymer as described in any one of the following. <10> The weight-average molecular weight (Mw) is 10,000 or more, and the degree of dispersion (Mw / Mn) is 3.5 or less. <1> ~ <9> A polymer as described in any one of the following. <11> <1> ~ <10> A composition for an organic electroluminescent element, comprising the polymer described in any one of the following. <12> A method for manufacturing an organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, The above-mentioned, <11> A method for manufacturing an organic electroluminescent element, comprising the step of forming it by a wet film deposition method using the organic electroluminescent element composition described above. <13> The organic layer has at least one of a hole injection layer and a hole transport layer. <12> A method for manufacturing an organic electroluminescent element as described above. <14> The anode and the cathode are interposed, comprising the hole injection layer, the hole transport layer, and the light-emitting layer. The organic layer comprises the hole injection layer, the hole transport layer, and the light-emitting layer. <13> A method for manufacturing an organic electroluminescent element as described above. <15> <1> ~ <10> An organic electroluminescent element comprising a polymer according to any one of the above, or a layer containing a polymer obtained by crosslinking the said polymer. <16> <15> An organic EL display device comprising the organic electroluminescent element described above. <17> <15> Organic EL lighting comprising the organic electroluminescent element described above. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a polymer with high excited singlet energy levels (S1) and excited triplet energy levels (T1), suppressing quenching due to energy transfer from the light-emitting material and excitons, and having high luminescence efficiency, as well as a composition for an organic electroluminescent device containing the polymer. [Brief explanation of the drawing]

[0025] [Figure 1]Figure 1 is a schematic cross-sectional view showing an example of the structure of the organic electroluminescent element of the present invention. [Modes for carrying out the invention]

[0026] The embodiments of the present invention will be described in detail below, but the present invention is not limited to the embodiments described below and can be implemented in various ways within the scope of its gist.

[0027] <polymer> The polymer of the present invention is a polymer containing a structure represented by the following formula (1).

[0028] [ka]

[0029] In formula (1), Ar 1 This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar 2 and Ar 3 Each of these independently represents a divalent aromatic hydrocarbon group which may have substituents, or a divalent group in which multiple aromatic hydrocarbon groups which may have substituents are linked directly or via linking groups in the direction of the main chain. X is -C(R 7 )(R 8 )-,-N(R 9 )-, or -C(R 10 )(R 11 )-C(R 12 )(R 13 )- represents, R 1 ~R 8 Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R1 , R 2 , R 5 , R 6 At least one of them is 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 9 ~R 13 each independently represents a hydrogen atom, 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, n represents an integer from 1 to 3.

[0030] At this time, for the structure constituting the main chain of the polymer, it is preferable that both of the two structures directly bonded to the nitrogen atom of the main chain amine of the formula (1) are phenylene groups which may have a substituent.

[0031] Also, when the atom bonded to Ar 3 in the repeating unit adjacent to and bonded to is not the nitrogen atom of the main chain amine, the ring bonded to the nitrogen atom of the main chain amine in Ar 3 has no substituent, 2 When the atom bonded to Ar in the repeating unit adjacent to and bonded to is the nitrogen atom of the main chain amine, it is preferable that at least one of the ring bonded to the nitrogen atom of the main chain amine in Ar 3 has no substituent and the ring bonded to the nitrogen atom of the main chain amine in Ar 3 has no substituent. 2 in Ar 3 is satisfied.

[0032] Furthermore, when the atom bonded to Ar 3 (This 7 - digit tag 3 should remain unchanged as per the rule)in the repeating unit adjacent to and bonded to is not the nitrogen atom of the main chain amine, among the structures represented by Ar 3 the structure bonded to the nitrogen atom of the main chain amine is a phenylene group having no substituent, <​​​​3 When the atom bonding to Ar is the nitrogen atom of the main-chain amine, 2 among the structures represented by Ar, the structure bonding to the nitrogen atom of the main-chain amine is a phenylene group having no substituent, and 3 among the structures represented by Ar, 3 it is preferable that at least one of the following is satisfied: the structure bonding to the nitrogen atom of the main-chain amine in the repeating unit bonding adjacent to Ar is a phenylene group having no substituent.

[0033] In addition, when the atom bonding to Ar in the repeating unit bonding adjacent to Ar is not the nitrogen atom of the main-chain amine, 3 Ar in the repeating unit bonding adjacent to Ar 3 where the structure bonding to Ar is not the nitrogen atom of the main-chain amine, 2 among the structures represented by Ar, Ar in which the structure bonding to the nitrogen atom of the main-chain amine is a phenylene group having no substituent 2 refers to the structure in the following formula (1)-4 representing Ar, where all of the following R 2 are hydrogen, 62 and also, when the atom bonding to Ar in the repeating unit bonding adjacent to Ar is the nitrogen atom of the main-chain amine, 3 Ar in the repeating unit bonding adjacent to Ar 3 where the structure bonding to Ar is the nitrogen atom of the main-chain amine, Ar in the structures represented by 2 where the structure bonding to the nitrogen atom of the main-chain amine is a phenylene group having no substituent 2 refers to the structure in the following formula (1)-4 representing Ar, where all of the following R 2 are hydrogen, 62 and Ar in the structures represented by 3 where the structure bonding to the nitrogen atom of the main-chain amine in the repeating unit bonding adjacent to Ar is a phenylene group having no substituent 3 refers to the structure in the following formula (1)-5 representing Ar, where all of the following R 3 are hydrogen. 3 In the following formula (1)-5 representing Ar, all of the following R 63 are hydrogen.

[0034] The reason why the polymer of the present invention exhibits the above effects is not clear, but the following is considered. The main chain of the polymer of the present invention includes a fluorene ring having substituents at specific positions, a carbazole ring having substituents at specific positions, or a 9,10-dihydrophenanthrene derivative structure having substituents at specific positions. Preferably, a phenylene group is bonded to the 2,7-position of these fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structures. The specific position is R 1 , R 2 , R 5 , or R 6 This is the substitution position.

[0035] These fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structures are R 1 , R 2 , R 5 , or R 6 By having substituents at the substitutional positions, the planes of the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure become more twisted relative to the planes of the ring bonded at positions 2 or 7 of those structures due to steric hindrance by the substituents. In this case, the polymer of the present invention has a main chain structure in which the expansion of the π-conjugated system is inhibited by the steric hindrance of the substituents, resulting in high excited singlet energy levels (S1) and excited triplet energy levels (T1), and excellent luminescence efficiency because quenching due to energy transfer from luminescent excitons is suppressed.

[0036] Furthermore, the two structures in the main chain of the polymer that are directly bonded to the nitrogen atom of the main chain amine in formula (1) are monocyclic phenylene groups, which is preferable because it increases the T1 and S1 energy levels.

[0037] Conventionally, as described in Patent Document 4, substituents were added to rings such as phenylene groups bonded to the nitrogen atom, causing a twist with structures such as fluorene bonded to the adjacent ring. When substituents are introduced to rings bonded to the nitrogen atom of the main chain amine in this way, it is thought that the presence of substituents inhibits the expansion of the HOMO around the nitrogen atom, resulting in weaker electron durability. In the present invention, when the ring bonded adjacent to the nitrogen atom of the main chain amine does not have substituents, the expansion of the HOMO around the nitrogen atom is not inhibited, and the HOMO expands to the ring adjacent to the nitrogen atom, achieving high electron durability. As a result, it is thought that an organic electroluminescent element with a long operating life can be obtained while maintaining high luminescence efficiency.

[0038] In this invention, when the ring bonded adjacent to the nitrogen atom of the main chain amine does not have substituents, the expansion of the HOMO around the nitrogen atom is not inhibited, and the HOMO extends to the ring adjacent to the nitrogen atom, resulting in high electron durability. As a result, it is believed that an organic electroluminescent element with a long operating lifetime can be obtained while maintaining high luminescence efficiency.

[0039] Also, R 1 , R 2 , R 5 , and R 6 It is believed that a fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure having substituents on at least one of these rings becomes more electrically stable and can achieve high durability by bonding an aromatic ring at the 2,7-position.

[0040] Furthermore, when the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure is bonded to an electron-withdrawing group, the LUMO is distributed entirely within the conjugated group extended from the 9th position of the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure. On the other hand, the HOMO is distributed in the main chain near the amine, so the intramolecular HOMO and LUMO are localized separately, which is thought to improve the resistance to electrons and excitons.

[0041] In an organic electroluminescent device, if the energy level difference between organic layers is not appropriate, it becomes difficult to inject carriers into the light-emitting layer, and the driving voltage increases. Or, carrier leakage from the light-emitting layer to adjacent layers is likely to occur, and the device efficiency is considered to decrease.

[0042] On the other hand, a charge transport material having an energy level higher than the energy level of excitons of the light-emitting material in the light-emitting layer as in the present invention has a high effect of confining excitons of the light-emitting material and is preferable.

[0043] Further, a layer obtained by wet film formation using the composition for an organic electroluminescent device containing the polymer of the present invention does not have cracks or the like and is flat. As a result, the organic electroluminescent device of the present invention having such a layer has high luminance and a long driving life.

[0044] Further, since the polymer of the present invention has excellent electrochemical stability, an organic electroluminescent device including a layer formed using the polymer of the present invention can be applied to flat panel displays (for example, for OA computers and wall-mounted TVs), in-vehicle display elements, mobile phone displays, light sources utilizing characteristics as surface light emitters (for example, light sources for copying machines, backlight sources for liquid crystal displays and instruments), display panels, and indicator lights, and its technical value is great.

[0045] (Ar 1 ) Ar 1 represents a monovalent group in which a plurality of groups selected from a monovalent aromatic hydrocarbon group which may have a substituent, a monovalent aromatic heterocyclic group which may have a substituent, or a monovalent aromatic hydrocarbon group which may have a substituent and a monovalent aromatic heterocyclic group which may have a substituent are directly or via a linking group linked.

[0046] In the polymer of the present invention, when there are a plurality of Ar 1 , the plurality of Ar 1 may be the same or different.

[0047] Preferred monovalent aromatic hydrocarbon groups are those having 6 to 60 carbon atoms. Specifically, examples include monovalent groups of 6-membered rings, either monocyclic or 2- to 5-condensed rings, such as benzene rings, azulene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings.

[0048] Preferably, the monovalent aromatic heterocyclic group is an aromatic heterocyclic group having 3 to 60 carbon atoms. Specifically, examples include monovalent groups of 5 or 6-membered rings or 2-4 fused rings such as furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrrole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, phenantholidine rings, perimidine rings, quinazoline rings, and quinazolinone rings.

[0049] Examples of linking groups include oxygen atoms or carbonyl groups. Since the triplet level can be increased by forming a non-conjugated structure with the aromatic ring, a structure in which phenylene rings are linked by oxygen atoms or carbonyl groups can also be used. Preferably, a structure in which the rings are directly linked without the use of linking groups. Ar 2 Ar 3 Ar 4 Ar 6 Ar 7 Ar 8 Ar 11 Ar 12 Ar 36 Ar 37 Ar 38 The same applies to the linking group in this case.

[0050] Among these, monovalent aromatic hydrocarbon groups are preferred due to their excellent charge transport properties and durability, monovalent groups of benzene or fluorene rings are more preferred, phenyl or fluorenyl groups are even more preferred, fluorenyl groups are particularly preferred, and 2-fluorenyl groups are most preferred.

[0051] Also, Ar 1 From the viewpoint of solubility in the 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, Ar 1 The 9-alkyl-2-fluorenyl group, in which an alkyl group is substituted at the 9-position of the 2-fluorenyl group, is preferred, and the 9,9-dialkyl-2-fluorenyl group, in which two alkyl groups are substituted, is particularly preferred. 1 The fluorenyl group, substituted with an alkyl group, is preferable because it improves solubility in the solvent.

[0052] As a monovalent group formed by directly linking or via linking groups multiple groups selected from optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, a monovalent group formed by directly linking or via linking groups multiple groups selected from the above aromatic hydrocarbon groups and aromatic heterocyclic groups can be used.

[0053] Among these, those represented by formula (A1), described later, are preferred, such as monovalent groups having a benzene ring and a carbazole ring, or monovalent groups having a triazine ring, from the viewpoint that the inclusion of an electron-withdrawing group lowers the LUMO of the molecule, making it more likely to accept electrons, and in polymers containing arylamines, the electron durability of the molecule is increased due to the localization of the LUMO and HOMO.

[0054] Ar 1 The substituents that may be present include groups selected from the substituent group Z described later or from the crosslinking groups described later.

[0055] (Ar 1 (Preferred range) Ar1 It is preferable that it be represented by the following formula (A1).

[0056] [ka]

[0057] In formula (A1), Ar 6 and Ar 7 Each independently represents a divalent aromatic hydrocarbon group which may have substituents, a heterocyclic aromatic group which may have substituents, or a divalent group in which multiple groups selected from a heterocyclic aromatic hydrocarbon group which may have substituents and a heterocyclic aromatic group which may have substituents are linked directly or via linking groups. Ar 8 This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar 9 represents a hydrogen atom or substituent, -* indicates the bond position with the nitrogen atom in formula (1), formula (2)-1, or formula (2)-2.

[0058] (Ar 6 Ar 7 ) As aromatic hydrocarbon groups, those having 6 to 60 carbon atoms are preferred. Specifically, examples include benzene rings, azulene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings, which are 6-membered monocyclic or 2- to 5-fused divalent rings, or divalent groups formed by linking multiple structures selected from these.

[0059] Preferred aromatic heterocyclic groups are those having 3 to 60 carbon atoms, specifically including furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrrole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, phenantholidine rings, perimidine rings, quinazoline rings, quinazolinone rings, and other divalent groups of 5-6 membered monocyclic or 2-4 fused rings, or divalent groups formed by linking multiple structures selected from these.

[0060] The divalent group, formed by the direct or via-linking groups of multiple groups selected from optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, may be a group in which multiple identical groups are linked, or a group in which multiple different groups are linked. The divalent group, formed by the direct or via-linking groups of multiple groups selected from optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, may be a monovalent group in which multiple above-mentioned aromatic hydrocarbon groups or above-mentioned aromatic heterocyclic groups are directly or via-linking groups.

[0061] Ar 6 and Ar 7 From the standpoint of excellent charge transport properties and durability, it is preferable that the group is a divalent group in which one or more groups selected from unsubstituted divalent aromatic hydrocarbon groups and unsubstituted divalent aromatic heterocyclic groups are directly or via linking groups, and from the standpoint of improved hole transport properties, an unsubstituted aromatic hydrocarbon group is preferred as the group directly bonded to the nitrogen atom, an unsubstituted phenylene group or an unsubstituted divalent fluorene group is more preferred, and an unsubstituted phenylene group is particularly preferred. The phenylene ring directly bonded to the nitrogen atom preferably has a fluorene ring, a carbazole ring, or a 9,10-dihydrophenanthrene derivative structure bonded thereto, and a structure in which one or more phenylene groups are further linked between the phenylene ring directly bonded to the nitrogen atom and the fluorene ring, the carbazole ring, or the 9,10-dihydrophenanthrene derivative structure is also preferable.

[0062] Ar 7 Ar is preferably a group in which 1 to 6 divalent aromatic hydrocarbon groups which may have substituents are linked from the viewpoint of the localization of the LUMO distributed at the 9-position of the carbazole ring and the HOMO distributed in the main chain, more preferably a group in which 2 to 4 divalent aromatic hydrocarbon groups which may have substituents are linked, still more preferably a group in which 1 to 4 phenylene rings which may have substituents are linked, and particularly preferably biphenylene in which 2 phenylene rings which may have substituents are linked.

[0063] (Ar 8 ) Ar 8 Ar is preferably a group in which one or more monovalent aromatic hydrocarbon groups which may be the same or different are linked from the viewpoints of excellent charge transportability and excellent durability, and the monovalent aromatic hydrocarbon group may have a substituent. As described above, from the viewpoint of the distribution of the LUMO in the structure represented by -Ar 7 -Ar 8 it is preferable that the number of linked groups is larger, but from the viewpoints of charge transportability and film stability, it is preferable that the number of linked groups is smaller. When linking, 2 or more and 10 or less are preferable, 6 or less is more preferable, and 3 or less is particularly preferable from the viewpoint of film stability.

[0064] Preferable aromatic hydrocarbon structures include a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring, and more preferably a benzene ring and a fluorene ring. Preferable aromatic heterocyclic structures include a benzothiophene ring, an indole ring, a carbazole ring, a triazine ring, and a quinazoline ring.

[0065] As a divalent group formed by the direct or via linking group linkage of multiple groups selected from optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, a group consisting of two to four optionally substituted phenylene rings linked together, or a group consisting of an optionally substituted phenylene ring linked to an optionally substituted fluorene ring, is preferred. From the viewpoint of broadening the LUMO, biphenylene, consisting of two optionally substituted phenylene rings linked together, is particularly preferred.

[0066] Ar 8 As substituents that may be present, any of the substituent group Z described later, or a combination thereof, can be used. From the viewpoint of inhibiting LUMO expansion, Ar 8 The substituents that may be present are preferably other than N-carbazolyl, indolocarbazolyl, and indenocarbazolyl groups, and more preferably phenyl, naphthyl, and fluorenyl groups.

[0067] Furthermore, it is preferable that the carbazole ring of formula (A1) has the structure shown below at position 9, and it is even more preferable that it has a structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-16, e1 to e4 and f1 to f4 from the viewpoint of distributing the LUMO of the molecule.

[0068] Furthermore, from the viewpoint of promoting the expansion of the molecule's LUMO by having electron-withdrawing groups, it is preferable to have a structure selected from a-1 to a-4, b-1 to b-6, d-1 to d-13, e1 to e4, and f1 to f4. Furthermore, from the viewpoint of having a high triplet level and the effect of confining excitons formed in the luminescence layer, it is preferable to have a structure selected from a-1 to a-4, d-1 to d-13, e1 to e4, f1, and f4. These structures may also have substituents. Note that in the following group of compounds, "-*" represents Ar 8 This indicates a combination with another element, and if there are multiple "-*" symbols, only one of them represents the combination.

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] Among the above group of compounds, R 30 and R 31 Each of these independently represents a hydrogen atom, or an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group.

[0073] Examples of alkyl groups, alkoxy groups, and aralkyl groups include R 1 ~R 8 A similar tool can be used, R 30 and R 31 R may also have substituents. 1 ~R 8 Similar materials can be used.

[0074] (Ar 9 ) Ar 9 represents a hydrogen atom or substituent. Ar 9 When is a substituent, it is not particularly limited, but preferably an aromatic hydrocarbon group which may have substituents or an aromatic heterocyclic group which may have substituents. A preferred structure is the Ar 4 This is similar to the basis mentioned earlier.

[0075] Ar 9 If Ar is a substituent, 9 It is preferable for Ar to be bound at the 3-position of carbazole from the viewpoint of improving durability. 9 From the viewpoint of ease of synthesis and charge transport properties, it is preferable that it be a hydrogen atom. 9From the viewpoint of improving durability and charge transport, it is preferable that the component is an aromatic hydrocarbon group that may have substituents or an aromatic heterocyclic group that may have substituents, and more preferably an aromatic hydrocarbon group that may have substituents.

[0076] Ar 9 When is an aromatic hydrocarbon group or an aromatic heterocyclic group that may have substituents, the substituents are the same as those listed in substituent group Z below or the crosslinking groups below, and the preferred substituents are the same as those further possessed by those substituents. Also, from the viewpoint of insolubilization, Ar 9 Preferably, it contains at least one crosslinkable group as a substituent, as described below.

[0077] The polymer of the present invention has a structure represented by formula (1), and Ar 1 However, it is preferable to include both a structure in which there is a monovalent group of a benzene ring or a fluorene ring that may have substituents, and a structure represented by formula (A1), and it is even more preferable to include both a structure in which there is a monovalent group of a fluorene ring that may have substituents, and a structure represented by formula (A1).

[0078] (Ar 2 Ar 3 ) Ar 2 and Ar 3 Each of these independently represents a divalent aromatic hydrocarbon group which may have substituents, or a divalent group in which multiple aromatic hydrocarbon groups which may have substituents are linked directly or via linking groups in the direction of the main chain.

[0079] Also, Ar 3 Ar in the repeating unit that is adjacent to and joined 3 If the atom bonding with it is not the nitrogen atom of the main chain amine, then Ar 2 In the structure represented by , the structure bonded to the nitrogen atom of the main chain amine is a phenylene group without substituents. Ar 3Ar in the repeating unit that is adjacent to and joined 3 If the atom that bonds with it is the nitrogen atom of the main chain amine, then Ar 2 In the structure represented by , the structure bonded to the nitrogen atom of the main chain amine is a phenylene group without substituents, and Ar 3 In the structure represented by Ar 3 It is preferable that at least one of the following conditions is met: the structure directly bonded to the nitrogen atom of the main chain amine in the repeating unit adjacent to it is a phenylene group without substituents.

[0080] As for the divalent aromatic hydrocarbon group, aromatic hydrocarbon groups having 6 to 60 carbon atoms are preferred, and specifically, examples include divalent groups of 6-membered monocyclic or 2- to 5-fused rings such as benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings.

[0081] Among these, divalent groups are preferred because they have excellent charge transport properties and durability, and one or more groups selected from divalent aromatic hydrocarbon groups without substituents are directly or via linking groups.

[0082] Because hole transport performance is improved, Ar 2 As such, an unsubstituted aromatic hydrocarbon group is preferred, an unsubstituted phenylene group or an unsubstituted divalent fluorene group is more preferred, and an unsubstituted phenylene group is particularly preferred. A fluorene ring, a carbazole ring, or a 9,10-dihydrophenanthrene derivative structure is preferably bonded to the phenylene ring directly bonded to the nitrogen atom, and a structure in which one or more phenylene groups are further linked between the phenylene ring directly bonded to the nitrogen atom and the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure is also preferred.

[0083] A divalent group formed by directly or via a linking group of an aromatic hydrocarbon group that may have multiple substituents may be a group in which multiple identical groups are linked, or a group in which multiple different groups are linked. Examples of divalent groups formed by the direct or via-linking of aromatic hydrocarbon groups, which may have multiple substituents, include biphenyl groups and terphenyl groups.

[0084] From the viewpoint of charge transport and durability, it is preferable that aromatic hydrocarbon groups, which may have multiple substituents, are directly bonded and linked without having linking groups.

[0085] Ar 2 and Ar 3 As substituents that may be present, any of the substituent group Z described later can be used. 2 and Ar 3 The substituents that may be present are preferably linear, branched, or cyclic alkyl groups that may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more, more preferably 4 or more, preferably 12 or less, and more preferably 8 or less, and the alkyl group is particularly preferably a hexyl group. 2 and Ar 3 The substituents that may be present can be in combination.

[0086] The substituents that linear, branched, or cyclic alkyl groups may have can be selected from the substituent group Z described later, but hydrogen atoms are particularly preferred from the viewpoint of stability.

[0087] Ar 2 and Ar 3 If the molecule has a ring adjacent to the nitrogen atom, at least one of the rings will be substituent-free, which lowers the molecule's HOMO and makes it easier to inject charge into the light-emitting layer. 2 and Ar 3 If the molecule has a ring adjacent to a nitrogen atom, it is particularly preferable that all of the rings are free of substituents.

[0088] (X) X is -C(R 7 )(R 8 )-,-N(R 9 )-, or -C(R 10 )(R 11 )-C(R 12 )(R 13 ) represents. X is preferably -C(R 7 )(R 8 )-, or -C(R 10 )(R 11 )-C(R 12 )(R 13 )-, and most preferably -C(R 7 )(R 8 )-is.

[0089] (R 1 ~R 8 ) R 1 ~R 8 Each of these independently represents hydrogen, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group.

[0090] R 1 ~R 8 Each of these elements independently comprises a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group, thereby allowing a twist to be formed in the main chain.

[0091] Examples of alkyl groups include linear, branched, or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl, and dodecyl groups.

[0092] As alkoxy groups, those with 1 to 24 carbon atoms are preferred because they tend to improve the solubility of the polymer. Specifically, examples include methoxy groups, ethoxy groups, n-propoxy groups, i-propoxy groups, n-butoxy groups, i-butoxy groups, tert-butoxy groups, and hexyloxy groups.

[0093] The aralkyl group is not particularly limited, but because it tends to improve the solubility of the polymer, an aralkyl group having 5 to 60 carbon atoms is preferred, an aralkyl group having 40 carbon atoms is more preferred, an aralkyl group having 7 or more carbon atoms is even more preferred, an aralkyl group having 10 or more carbon atoms is even more preferred, and an aralkyl group having 12 or more carbon atoms is particularly preferred.

[0094] Specifically, examples include 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 1,1-di(n-hexyl)-1-phenylmethyl group, 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 6-naphthyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group, 8-phenyl-1-n-octyl group, and 4-phenylcyclohexyl group.

[0095] R 1 ~R 8 If R is not a hydrogen atom, 1 ~R 8 The alkyl group is preferably a linear, branched, or cyclic alkyl group, which may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but to maintain the solubility of the polymer, it is preferably 1 to 6 carbon atoms, more preferably 3 or less, and even more preferably a methyl group or an ethyl group.

[0096] R other than hydrogen atoms 1 ~R 8When multiple R atoms exist, the charge can be uniformly distributed around the nitrogen atom, and furthermore, synthesis is easy, so R atoms other than hydrogen atoms are also available. 1 ~R 8 If multiple such groups exist, it is preferable that they be the same group.

[0097] Also, R 1 , R 2 , R 5 , R 6 At least one of these is an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group.

[0098] From the perspective of forming a twist, R 1 and R 2 together, or R 5 and R 6 Preferably, both are alkyl groups which may have substituents, alkoxy groups which may have substituents, or aralkyl groups which may have substituents, and from a synthetic viewpoint, R is particularly preferable. 1 and R 2 It is particularly preferable that each of these independently be an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group.

[0099] From the standpoint of having the best durability, R is the most preferred. 1 and R 2 Each of these is an alkyl group independently. The number of carbon atoms in the alkyl group is preferably 8 or less, and more preferably 6 or less, because it is thought to cause a twist in the main chain and keep the distance between polymers in the film from increasing, resulting in excellent charge transport properties. The number of carbon atoms in the alkyl group is preferably 4 or less, as this is thought to further improve charge transport properties by keeping the distance between polymers in the film from increasing. A methyl group with 1 carbon atom is even more preferable.

[0100] R 1 ~R 8The substituents that may be present are preferably one of the substituent group Z described later, an aralkyl group having 7 to 40 carbon atoms, or an aralkyl group of a heterocyclic ring having 4 to 37 carbon atoms, or a combination thereof.

[0101] R 1 ~R 8 From the viewpoint of durability, the substituents that may be present are preferably C1-C24 alkyl groups, C7-C40 aralkyl groups, C3-C37 heterocyclic aralkyl groups, C10-C24 arylamino groups, C6-C36 aromatic hydrocarbon groups, or C3-C36 aromatic heterocyclic groups. A C1-C12 alkyl group, a C7-C30 aralkyl group, a C3-C27 heterocyclic aralkyl group, a C6-C24 aromatic hydrocarbon group, or a C3-C24 aromatic heterocyclic group is more preferable. An aryl group having 6 to 24 carbon atoms is even more preferred.

[0102] R 1 ~R 8 From the viewpoint of charge transport, the substituents that may be present are preferably aromatic hydrocarbon groups having 6 to 24 carbon atoms, or aromatic heterocyclic groups having 3 to 24 carbon atoms, and more preferably phenyl groups, naphthyl groups, fluorenyl groups, carbazolyl groups, indolocarbazolyl groups, indenocarbazolyl groups, or indenofluorenyl groups.

[0103] Also, R 1 ~R 8 From a synthetic standpoint, it is preferable that the component is hydrogen, an unsubstituted alkyl group, an unsubstituted alkoxy group, or an unsubstituted aralkyl group.

[0104] (R 9 ~R 13 ) R 9 ~R 13Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group.

[0105] Examples of alkyl groups, alkoxy groups, and aralkyl groups include R 1 ~R 8 A similar tool can be used, R 9 ~R 13 R may also have substituents. 1 ~R 8 Similar materials can be used.

[0106] As aromatic hydrocarbon groups, those having 6 to 60 carbon atoms are preferred. Specifically, examples include monovalent groups of 6-membered rings, either monocyclic or 2- to 5-condensed rings, such as benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings. From the viewpoint of durability, monovalent groups of benzene rings and fluorene rings are particularly preferred.

[0107] X possesses R 7 ~R 13 The substituents that may further be present are preferably crosslinkable groups, as described below, from the viewpoint of improving solvent insolubility when the polymer of the present invention is laminated by coating another layer after film formation. In particular, R is preferred because it does not interfere with charge transport. 7 , R 8 , R 10 ~R 13 Preferably, one of them has a crosslinking group as a further substituent, R 7 and R 8 It is even more preferable that at least one of them has a crosslinking group as a further substituent, as described below.

[0108] Furthermore, X is -C(R 7 )(R 8 )- and R 5 and / or R 6If R is not a hydrogen atom, 7 and R 5 , R 7 and R 6 , R 8 and R 5 , and R 8 and R 6 In either case, they do not combine to form a ring.

[0109] Furthermore, it is preferable that the two structures in the main chain of the polymer that are bonded to the nitrogen atom of the main chain amine in formula (1) are phenylene groups, which may have substituents.

[0110] <Preferred repeating unit structure> In particular, the repeating unit represented by formula (1) above is more preferably represented by formula (2)-1 or formula (2)-2 below.

[0111] [ka]

[0112] In equation (2)-1 or equation (2)-2, Ar 1 , R 1 ~R 6 X is the same as the definition in equation (1) above, R 20 ~R 23 Each of them independently, R 1 It is similar to this, g, h, and i each independently represent integers between 1 and 3. j and k each independently represent integers between 1 and 2. Furthermore, the structure in the main chain of the polymer that is directly bonded to the nitrogen atom of the main chain amine in formula (2)-1 or formula (2)-2 is preferably an unsubstituted phenylene group.

[0113] (g, h, i, j, and k) g and i are each independent integers between 1 and 3. Furthermore, it is preferable that g+i is 2 or greater. Moreover, it is preferable that g and i are each independently 2 or less, and it is even more preferable that both g and i are 1, as this does not hinder charge transport.

[0114] h is an integer between 1 and 3. Furthermore, it is preferable that h is 2 or less, and even more preferable that h be 1, as this does not hinder charge transport.

[0115] j and k are each independent integers between 1 and 2. Furthermore, it is preferable that j+k is 2 or greater. Moreover, it is preferable that j and k are each independently 2 or less, and it is even more preferable that both j and k are 1, as this does not hinder charge transport.

[0116] If h, j, and k are all 1, or if h, j, and k are all 2, then R 20 =R 23 , and R 21 =R 22 This is preferable because it results in a symmetrical structure.

[0117] From the viewpoint of device durability or voltage reduction when used in organic electroluminescent devices, it is preferable to include repeating units represented by formula (2)-1 or formula (2)-2.

[0118] <Preferred repeating unit structure and substructure> In the structure constituting the main chain of the polymer of the present invention, it is even more preferable that both structures directly bonded to the nitrogen atom of the main chain amine in formula (1) are phenylene groups which may have substituents. Here, in the structure constituting the main chain of the polymer, the two structures directly bonded to the nitrogen atom of the main chain amine in formula (1) are both phenylene groups which may have substituents, in the following two cases: (a) and (b). (a) When multiple repeating units represented by formula (1) are linked together and repeated. (b) When a structure other than that represented by formula (1) is coupled next to N of the repeating unit represented by formula (1).

[0119] Here, In case (a), the polymer of the present invention has repeating units represented by the following formula (1)-2, (b) In this case, the polymer of the present invention has a substructure represented by the following formula (1)-3.

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] (In equation (1)-2, Ar 1 Ar 2 Ar 3 , R 1 ~R 6 X and n are Ar in equation (1). 1 Ar 2 Ar 3 , R 1 ~R 6 , X, n represent, n62 and n63 are 4. Multiple R 62 Each of these independently represents R in equation (1). 1 It is similar to the above, that is, it represents hydrogen, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group, Multiple R 63 Each of these independently represents R in equation (1). 1 It is similar to the above, that is, it represents hydrogen, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group, However, Ar2 is equation (1)-4, and Ar 3 Equation (1)-5, In equation (1)-4, * represents a bond in the main chain. Ar 32 is Ar in the above formula (1) 2 From, Ar 2 The remaining structure is obtained by removing the phenylene group, which may have substituents, that is bonded to the nitrogen atom of the main chain in formula (1), However, Ar 2 In the case of a phenylene group which may have substituents, it represents a direct bond. In equation (1)-5, * represents a bond in the main chain. Ar 33 is Ar in the above formula (1) 3 From, Ar 3 The remaining structure is obtained by removing the phenylene group, which may have substituents, that is directly bonded to the adjacent repeating unit of the repeating unit represented by formula (1) in the formula, However, Ar 3 In the case of a phenylene group which may have substituents, it represents a direct bond. In equation (1)-3, R represented by Q 62 The phenylene group which may have is part or all of the structure that is directly bonded to N in the repeating unit represented by formula (1), Ar 1 Ar 2 Ar 32 , R 1 ~R 6 , R 62 , X, n, n62 are Ar in equation (1)-2 1 Ar 2 Ar 32 , R 1 ~R 6 , R 62 , X, n, n62 are similar, Ar 3 In equation (1), Ar 3 It is similar to this, n61 is 4. Multiple R 61 Each of these independently represents R in equation (1).1 It is similar to the above, that is, it represents hydrogen, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group, However, Ar 2 This is equation (1)-4.

[0124] Ar in equation (1)-3 3 It is preferable that the structure is represented by formula (1)-5.

[0125] When the polymer of the present invention is a polymer having repeating units represented by formula (1)-2, the repeating units represented by formula (1)-2 are preferably the following formula (1)-2-2, and more preferably the following formula (1)-2-3.

[0126] [ka]

[0127] Equation (1)-2-2 is the same as the above equation (1)-2, where there are four R 62 Two of them are hydrogen, and there are four R 63 These two represent hydrogen, Two R groups bonded to the phenylene group 62 At least one of them is not hydrogen, and the two R atoms are bonded to the phenylene group. 63 At least one of them is not hydrogen.

[0128] [ka]

[0129] Equation (1)-2-3 is obtained by taking the four R values ​​in equation (1)-2. 62 and the four R 63 This indicates that all of them are hydrogen.

[0130] When the polymer of the present invention has a substructure represented by formula (1)-3, the substructure represented by formula (1)-3 is preferably formula (1)-3-2, and more preferably formula (1)-3-3.

[0131] [ka]

[0132] Equation (1)-3-2 is obtained by taking the four R values ​​in the above equation (1)-3. 61 Two of them are hydrogen, and there are four R 62 These two represent hydrogen, Two R groups bonded to the phenylene group 61 At least one of them is not hydrogen, and the two R atoms are bonded to the phenylene group. 62 At least one of them is not hydrogen.

[0133] Ar in equation (1)-3-2 3 It is preferable that the structure is represented by formula (1)-5.

[0134] [ka]

[0135] Equation (1)-3-3 is the same as the above equation (1)-3, where there are four R 61 and the four R 62 This indicates that all of them are hydrogen.

[0136] Ar in equation (1)-3-3 3 It is preferable that the structure is represented by formula (1)-5. Furthermore, Ar represented by formula (1)-4 above 2 Preferably, the structure is represented by formula (1)-4-2 or formula (1)-4-3.

[0137] [ka]

[0138] In equations (1)-4-2 and (1)-4-3, R 20 , R 22 Each of these independently corresponds to R in equation (2)-2 above. 20 , R 22 It is similar to this, g is the same as g in equation (2)-1 above, representing an integer from 1 to 3, and the preferred value and reason are the same as g in equation (2)-1 above. j is the same as j in equation (2)-2 above, representing an integer between 1 and 2, and the preferred value and reason are the same as for j in equation (2)-2 above.

[0139] Furthermore, Ar, represented by formula (1)-5 above 3 Preferably, the structure is represented by formula (1)-5-2 or formula (1)-5-3.

[0140] [ka]

[0141] In equations (1)-5-2 and (1)-5-3, R 23 , R 24 Each of these independently corresponds to R in equation (2)-2 above. 23 , R 24 It is similar to this, i is the same as i in equation (2)-1 above, representing an integer from 1 to 3, and the preferred value and reason are the same as i in equation (2)-1 above. k is the same as k in equation (2)-2 above, representing an integer between 1 and 2, and the preferred value and reason are the same as for k in equation (2)-2 above.

[0142] In each of the substructures constituting the structures represented by formulas (1)-2, (1)-3, (1)-4, (1)-5, (1)-2-2-, (1)-2-3, (1)-3-2, (1)-3-3, (1)-4, (1)-4-2, (1)-4-3, (1)-5, (1)-5-2, and (1)-5-3, if substituents are permitted, they can be selected from the substituent group Z described later. Preferably, the structure does not have any substituents.

[0143] (substituent group Z) The substituent group Z includes the following structures. For example, linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, typically 24 or less, and preferably 12 or less, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl groups; For example, an alkenyl group such as a vinyl group, which usually has 2 or more carbon atoms, usually 24 or fewer, preferably 12 or fewer; For example, an alkynyl group such as an ethynyl group, which usually has 2 or more carbon atoms, usually 24 or less, preferably 12 or less; For example, alkoxy groups such as methoxy groups and ethoxy groups, which typically have one or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, aryloxy or heteroaryloxy groups such as phenoxy groups, naphthoxy groups, and pyridyloxy groups, which typically have 4 or more carbon atoms, preferably 5 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer; For example, alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups, which typically have 2 or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, dialkylamino groups such as dimethylamino groups and diethylamino groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, diarylamino groups such as diphenylamino groups, ditylamino groups, and N-carbazolyl groups, which typically have 10 or more carbon atoms, preferably 12 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer; For example, arylalkylamino groups such as phenylmethylamino groups, which typically have 7 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer; For example, acyl groups such as acetyl groups and benzoyl groups, which typically have 2 or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, a haloalkyl group having typically one or more carbon atoms, typically 12 or fewer, preferably 6 or fewer, such as a trifluoromethyl group; For example, alkylthio groups such as methylthio groups and ethylthio groups, which typically have 1 or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, arylthio groups such as phenylthio groups, naphthylthio groups, and pyridylthio groups, which typically have 4 or more carbon atoms, preferably 5 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer; For example, silyl groups such as trimethylsilyl group and triphenylsilyl group, which typically have 2 or more carbon atoms, preferably 3 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer carbon atoms; For example, siloxy groups such as trimethylsiloxy group and triphenylsiloxy group, which typically have 2 or more carbon atoms, preferably 3 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer carbon atoms; Cyano group; For example, aromatic hydrocarbon groups such as phenyl groups and naphthyl groups, which typically have 6 or more carbon atoms, and usually 36 or fewer, preferably 24 or fewer; For example, aromatic heterocyclic groups such as thienyl groups and pyridyl groups, which typically have 3 or more carbon atoms, preferably 4 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer.

[0144] Among the substituent group Z described above, preferably are alkyl groups, alkoxy groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups. From the viewpoint of charge transport properties or ease of synthesis, Ar 1 ~Ar 3 , R1 ~R 13 , R 20 ~R 23 It is even more preferable that it does not have substituents.

[0145] Furthermore, each substituent in the substituent group Z may have further substituents. Examples of these substituents include those identical to the substituents (substituent group Z) or the crosslinking groups described later. Preferably, each substituent in the substituent group Z has no further substituents, or has an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, a phenyl group, or the crosslinking groups described later. From the viewpoint of charge transport, it is more preferable that each substituent in the substituent group Z has no further substituents.

[0146] [Terminal group] In the present invention, the term "end group" refers to the structure of the end portion of a polymer formed by an end capping agent used at the end of polymerization. The end groups of the polymer in the present invention are usually hydrocarbon groups. From the viewpoint of charge transport properties, the number of carbon atoms in the hydrocarbon group is preferably 1 to 60, more preferably 1 to 40, and even more preferably 1 to 30.

[0147] Preferably, For example, linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, typically 24 or less, and preferably 12 or less, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl groups; For example, an alkenyl group such as a vinyl group, which usually has 2 or more carbon atoms, usually 24 or fewer, preferably 12 or fewer; For example, an alkynyl group such as an ethynyl group, which usually has 2 or more carbon atoms, usually 24 or less, preferably 12 or less; Examples include aromatic hydrocarbon ring groups such as phenyl groups and naphthyl groups, which typically have 6 or more carbon atoms, and usually 36 or fewer, preferably 24 or fewer.

[0148] These hydrocarbon groups may have further substituents, and the substituents that may be further substituents are preferably alkyl groups or aromatic hydrocarbon groups. If there are multiple such substituents, they may be bonded to each other to form a ring.

[0149] These further substituents are preferably alkyl groups or aromatic hydrocarbon groups, and more preferably aromatic hydrocarbon groups, from the viewpoint of charge transport and durability.

[0150] [Soluble group] The polymer of the present invention preferably has a soluble group in order to exhibit solubility in a solvent. The soluble group in the present invention is a group having a linear or branched alkyl group or alkylene group having 3 to 24 carbon atoms, preferably 12 carbon atoms or less.

[0151] Among these, alkyl groups, alkoxy groups, or aralkyl groups are preferred, such as n-propyl groups, 2-propyl groups, n-butyl groups, and isobutyl groups. More preferably, n-hexyl groups or n-octyl groups are preferred. The soluble group may have substituents.

[0152] The aforementioned R 1 ~R 13 and R 20 ~R 23 If one or more of these structures are present, those groups are considered soluble groups. Furthermore, if the substituents in the present invention satisfy the conditions for a soluble group, those substituents are considered soluble groups.

[0153] (Number of soluble groups) The polymer of the present invention is preferable to have a large number of soluble groups in order to make it easier to obtain a polymer solution that can be used in wet film deposition. On the other hand, it is preferable to have fewer soluble groups in order to minimize the reduction in film thickness due to the dissolution of the layer in the solvent when another layer is formed on top of the deposited layer using the wet film deposition method.

[0154] The number of soluble groups in the polymer of the present invention can be expressed as the number of moles per gram of polymer. When the number of soluble groups in the polymer of the present invention is expressed as moles per gram of polymer, it is usually 4.0 mmol or less, preferably 3.0 mmol or less, more preferably 2.0 mmol or less, and also usually 0.1 mmol or more, preferably 0.5 mmol or more.

[0155] When the number of soluble groups is within the above range, the polymer dissolves easily in the solvent, making it easier to obtain a polymer-containing composition suitable for wet film deposition. Furthermore, because the soluble group density is appropriate, the polymer exhibits sufficient sparing solubility in organic solvents after heating and drying. Therefore, a multilayer structure can be formed using the wet film deposition method.

[0156] Here, the number of soluble groups per gram of polymer can be calculated from the molecular ratio of the monomers used in synthesis and the structural formula, after removing the terminal groups from the polymer.

[0157] As explained below, in the case of polymer 1 synthesized in Example 1 described later, the average molecular weight of the repeating units excluding the terminal groups in polymer 1 is 682, and the average number of soluble hexyl groups per repeating unit is 0.9. Calculating this using simple proportion, the number of soluble groups per gram of molecular weight is calculated to be 1.31 millimoles.

[0158] [ka]

[0159] [Crosslinkable group] The polymer of the present invention may have crosslinkable groups. The crosslinkable groups in the polymer of the present invention may be present in the repeating unit represented by formula (1), or in a repeating unit other than the repeating unit represented by formula (1). In particular, the Ar side chain 1 Having crosslinkable groups is preferable because it facilitates the crosslinking reaction.

[0160] The polymer of the present invention has crosslinkable groups, which allows for a significant difference in solubility in organic solvents before and after a reaction (poor solubility reaction) caused by irradiation with heat and / or active energy rays.

[0161] A crosslinkable group is a group that, upon irradiation with heat and / or active energy rays, reacts with other molecules located near it to form a new chemical bond. In this case, the reacting group may be the same as the crosslinking group or a different group.

[0162] The crosslinkable group is preferably a cyclobutene ring fused to an aromatic ring, or a group containing an alkenyl group bonded to an aromatic ring, and more preferably a group selected from the following crosslinkable group T. The crosslinkable group is preferably further substituted with substituent group Z.

[0163] (Crosslinkable group T) The crosslinkable group T has the following structure.

[0164] [ka]

[0165] In the above crosslinkable group T, R 24 ~R 26 Each of these independently represents a hydrogen atom or an alkyl group. 27 ~R 29 Each of these independently represents an alkyl group or an alkoxy group. 21 Ar 22 represents an aromatic hydrocarbon group or aromatic heterocyclic group which may have substituents. p represents an integer from 1 to 4, q represents an integer from 1 to 5, and r represents an integer from 1 to 7.

[0166] When p is 2 or greater, multiple R 27 The adjacent R can be the same or different, and 27 They may join together to form a ring. When q is 2 or greater, multiple R 28The R rings may be the same or different, and they can be substituted into the aromatic ring. 28 They may join together to form a ring. When r is 2 or greater, multiple R 29 They may be the same or different.

[0167] R 24 ~R 29 Examples of alkyl groups include linear or branched linear alkyl groups having 6 or fewer carbon atoms. Examples include methyl, ethyl, n-propyl, 2-propyl, n-butyl, and isobutyl groups. More preferably, methyl or ethyl groups. 24 ~R 29 Because the alkyl group has 6 or fewer carbon atoms, it does not sterically inhibit the crosslinking reaction, and film insolubilization tends to occur easily.

[0168] R 27 ~R 29 Examples of alkoxy groups include linear or branched alkoxy groups having 6 or fewer carbon atoms, such as methoxy, ethoxy, n-propoxy, 2-propoxy, and n-butoxy groups. More preferably, a methoxy or ethoxy group. 27 ~R 29 If the alkoxy group has 6 or fewer carbon atoms, it does not sterically inhibit the crosslinking reaction, and film insolubilization tends to occur more easily.

[0169] Ar 21 Ar 22 In this context, examples of aromatic hydrocarbon groups that may have substituents include monocyclic or 2-5 fused rings of 6 members, such as benzene rings and naphthalene rings, having one free valency. A benzene ring having one free valency is particularly preferred.

[0170] Also, Ar 21 Ar 22In this context, preferred aromatic heterocyclic groups may have substituents and have one free valency, with 3 to 60 carbon atoms. Specifically, examples include monovalent groups of 5-6 membered monocyclic or 2-4 fused rings, such as furan rings, benzofuran rings, thiophene rings, benzothiophene rings, imidazole rings, indole rings, carbazole rings, benzimidazole rings, pyridine rings, pyrimidine rings, triazine rings, isoquinoline rings, quinoxaline rings, phenanthridine rings, and quinazoline rings, or monovalent groups formed by linking multiple structures selected from these. Benzofuran rings, benzothiophene rings, carbazole rings, and triazine rings are particularly preferred.

[0171] Ar 22 This may be a group in which two or more aromatic hydrocarbon groups, which may have substituents, are bonded together. Examples of such groups include biphenylene groups and terphenylene groups, with 4,4'-biphenylene groups being preferred. Ar 21 Ar 22 The substituents that may be present are the same as those of the substituent group Z mentioned above.

[0172] As crosslinking groups, cycloaddition groups such as aryl vinyl carbonyl groups including cinnamoyl groups, benzocyclobutene rings with monovalent free valence, and 1,2-dihydrocyclobuta[a]naphthalene rings with monovalent free valence are preferred in that they further improve the electrochemical stability of the device.

[0173] Furthermore, among the crosslinkable groups, groups containing a cyclobutene ring fused to an aromatic ring with a monovalent free valence, or a 1,2-dihydrocyclobuta[a]naphthalene ring with a monovalent free valence are preferred in terms of the particularly stable structure after crosslinking. Among these, groups containing a benzocyclobutene ring or a 1,2-dihydrocyclobuta[a]naphthalene ring with a monovalent free valence are even more preferred, and groups containing a 1,2-dihydrocyclobuta[a]naphthalene ring with a monovalent free valence are particularly preferred in terms of the low crosslinking reaction temperature.

[0174] (Number of crosslinking groups) In the polymer of the present invention, a greater number of crosslinkable groups is preferable because they become sufficiently insoluble upon crosslinking, making it easier to form other layers on top of them by wet film deposition. On the other hand, a smaller number of crosslinkable groups is preferable because it makes it less likely for cracks to occur in the formed layer, less unreacted crosslinkable groups to remain, and the organic electroluminescent device tends to have a longer lifespan.

[0175] In the polymer of the present invention, the number of crosslinkable groups present in one polymer chain is preferably 1 or more, more preferably 2 or more, and preferably 200 or less, more preferably 100 or less.

[0176] Furthermore, the number of crosslinkable groups in the polymer of the present invention can be expressed as the number per 1000 units of molecular weight of the polymer.

[0177] When the number of crosslinkable groups in the polymer of the present invention is expressed as the number per 1000 units of molecular weight of the polymer, it is usually 3.0 or less, preferably 2.0 or less, more preferably 1.0 or less, and also usually 0.01 or more, preferably 0.05 or more.

[0178] When the number of crosslinkable groups is within the above range, cracks are less likely to occur, and a flat film is more easily obtained. Furthermore, because the crosslinking density is moderate, there are few unreacted crosslinkable groups remaining in the layer after the crosslinking reaction, which does not significantly affect the lifespan of the resulting device. Furthermore, because it exhibits sufficient poor solubility in organic solvents after the crosslinking reaction, it is easy to form a multilayer laminated structure using the wet film deposition method.

[0179] [Content of repeating units] In the polymer of the present invention, the content of the repeating unit represented by formula (1) is not particularly limited, but it is usually contained in the polymer in an amount of 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, and particularly preferably 30 mol% or more. The polymer of the present invention may consist only of the repeating unit represented by formula (1), but for the purpose of balancing the various performances when used as an organic electroluminescent element, it may also have repeating units other than those of formula (1). In that case, the content of the repeating unit represented by formula (1) in the polymer is usually 50 mol% or more, preferably 60 mol% or more.

[0180] [Other preferred repeating units that may be included] The polymer of the present invention preferably further comprises at least one of the repeating units represented by the following formula (3)-1 and the following formula (3)-2.

[0181] [ka]

[0182] In equation (3)-1 or equation (3)-2, Ar 4 In each repeating unit, independently, a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups, X 30 -C(R 37 )(R 38 )-,-N(R 39 )-, or -C(R 40 )(R 41 )-C(R 42 )(R 43 )- represents, R 33 , R 34 , R 37 , R 38 , R 120~R 123 Each of these independently represents hydrogen, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R 39 ~R 43 Each of these independently represents hydrogen, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group. g 3 h 3 i 3 Each of these independently represents an integer between 1 and 3. j 3 , k 3 Each of these independently represents an integer between 1 and 2.

[0183] R 33 , R 34 , R 37 , R 38 , R 120 ~R 123 In this context, alkyl groups, alkoxy groups, and aralkyl groups are R 1 ~R 8 Similar materials can be used.

[0184] R 39 ~R 43 In R, alkyl groups, alkoxy groups, aralkyl groups, and aromatic hydrocarbon groups are R 9 ~R 13 Similar materials can be used.

[0185] (Ar 4 ) Ar 4 In each repeating unit, independently, a monovalent aromatic hydrocarbon group may have substituents, a monovalent aromatic heterocyclic group may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group and a monovalent aromatic heterocyclic group may have substituents are linked directly or via linking groups. In the polymer of the present invention, Ar 4 If multiple Ar4 They may be the same or different.

[0186] Preferred aromatic hydrocarbon groups are those having 6 to 60 carbon atoms. Specifically, examples include monovalent groups of 6-membered rings or 2- to 5-fused rings, such as benzene rings, azulene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings, or monovalent groups formed by linking multiple structures selected from these.

[0187] Preferred aromatic heterocyclic groups are monovalent groups of 5-6 membered rings or 2-4 fused rings, such as furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrrole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, phenanthridine rings, perimidine rings, quinazoline rings, and quinazolinone rings, or monovalent groups formed by linking multiple structures selected from these.

[0188] Ar 4 From the standpoint of excellent charge transport properties and durability, substituted aromatic hydrocarbon groups are preferred, among which substituted monovalent groups of benzene or fluorene rings are more preferred, i.e., substituted phenyl or fluorenyl groups, even more preferred, substituted fluorenyl groups are even more preferred, and substituted 2-fluorenyl groups are particularly preferred.

[0189] Ar 4The substituents that the aromatic hydrocarbon group and aromatic heterocyclic group may have are not particularly limited, as long as they do not significantly reduce the properties of the polymer of the present invention. Preferably, these are groups selected from the substituent group Z or the crosslinkable groups, and alkyl groups, alkoxy groups, aromatic hydrocarbon groups, aromatic heterocyclic groups or the crosslinkable groups are preferred, with alkyl groups being more preferred.

[0190] Ar 4 From the viewpoint of solubility in the 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 the 2-fluorenyl group is preferred, and a 9,9-dialkyl-2-fluorenyl group in which two alkyl groups are substituted is particularly preferred.

[0191] Ar 4 The fact that the fluorenyl group has at least one of the 9th and 9' positions substituted with an alkyl group tends to improve solubility in solvents and durability of the fluorene ring. Furthermore, Ar 4 The presence of a fluorenyl group with both the 9th and 9' positions substituted with alkyl groups tends to further improve solubility in solvents and the durability of the fluorene ring.

[0192] Also, Ar 4 It is preferable that the material contains the aforementioned crosslinkable group, as this improves its insolubility in the solvent when layered coating after film formation.

[0193] From the viewpoint of insolubilization, the polymer of the present invention preferably includes, as further substituents, repeating units represented by formulas (3)-1 and (3)-2, which include at least one of the aforementioned crosslinkable groups, wherein the crosslinkable group is Ar 4 It is preferable that the aromatic hydrocarbon group or aromatic heterocyclic group represented by is further substituted with substituents that may be present on the group.

[0194] From the viewpoint of device durability or voltage reduction when used in organic electroluminescent devices, the polymer of the present invention preferably further contains repeating units represented by formula (3)-1.

[0195] (Ar 4 (Preferred range) Ar 4 It is preferable that it be represented by the following formula (A2).

[0196] [ka]

[0197] In formula (A2), Ar 36 and Ar 37 Each independently represents a divalent aromatic hydrocarbon group which may have substituents, a heterocyclic aromatic group which may have substituents, or a divalent group in which multiple groups selected from a heterocyclic aromatic hydrocarbon group which may have substituents and a heterocyclic aromatic group which may have substituents are linked directly or via linking groups. Ar 38 This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar 39 represents a hydrogen atom or substituent, -* represents the bond position with the nitrogen atom in formula (3)-1 or formula (3)-2.

[0198] Ar 36 ~Ar 39 Specific examples and preferred ranges are, 6 ~Ar 9 It is similar to that.

[0199] [Molecular weight of polymer] The weight-average molecular weight (Mw) of the polymer of the present invention is typically 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 200,000 or less, and particularly preferably 100,000 or less. It is also typically 10,000 or more, preferably 15,000 or more, and more preferably 20,000 or more.

[0200] When the weight-average molecular weight of the polymer is below the upper limit, solubility in the solvent is obtained, and the film-forming properties tend to be excellent. Furthermore, when the weight-average molecular weight of the polymer is above the lower limit, the decrease in the polymer's glass transition temperature, melting point, and vaporization temperature is suppressed, which may improve heat resistance. In addition, the insolubility of the coating film in organic solvents after the crosslinking reaction may be sufficient.

[0201] Furthermore, the number-average molecular weight (Mn) of the polymer of the present invention 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. Also, it 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.

[0202] Furthermore, the degree of dispersion (Mw / Mn) in the polymer of the present invention is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. Since a smaller degree of dispersion is better, the lower limit is ideally 1. When the degree of dispersion of the polymer of the present invention is below the above upper limit, purification is easy, and solubility in solvents and charge transport ability are good.

[0203] Typically, the weight-average molecular weight and number-average molecular weight of polymers are determined by SEC (size exclusion chromatography) measurement. In SEC measurement, components with higher molecular weights have shorter elution times, while components with lower molecular weights have longer elution times. However, by using a calibration curve calculated from the elution time of polystyrene (standard sample) with a known molecular weight, the weight-average molecular weight and number-average molecular weight can be calculated by converting the sample's elution time to molecular weight.

[0204] [Other repeating units] The polymer of the present invention may further contain repeating units represented by formula (5) or formula (6) in terms of charge transport properties and durability. The repeating units represented by formula (5) below include structures that coincide with some structural parts of the repeating units represented by formulas (1), (2)-1, (2)-2, (3)-1, or (3)-2, but are structures of repeating units other than those.

[0205] [ka]

[0206] In formula (5), Ar 10 This represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group. Ar 11 This represents a divalent aromatic hydrocarbon group which may have substituents, a divalent aromatic heterocyclic group which may have substituents, or a divalent group in which multiple groups selected from a divalent aromatic hydrocarbon group which may have substituents and a divalent aromatic heterocyclic group which may have substituents are linked in the direction of the main chain, either directly or via linking groups.

[0207] In formula (6), Ar 12 This represents a divalent aromatic hydrocarbon group which may have substituents, a divalent aromatic heterocyclic group which may have substituents, or a divalent group in which multiple groups selected from a divalent aromatic hydrocarbon group which may have substituents and a divalent aromatic heterocyclic group which may have substituents are linked in the direction of the main chain, either directly or via linking groups.

[0208] (Ar 10 Ar 11 and Ar 12 ) Ar 10 Ar 11 and Ar 12 In this context, the aromatic hydrocarbon group and aromatic heterocyclic group are Ar 10 is Ar in equation (1) 1 Similar to the base, Ar 11 and Ar 12is Ar of equation (A1) 6 It represents a similar group as Ar. 10 Ar 11 and Ar 12 The substituents that may be present are preferably the substituent group Z or groups similar to the crosslinking group. In the polymer of the present invention, Ar 10 If multiple Ar 10 They may be the same or different.

[0209] [Preferred polymer] The polymer of the present invention most preferably contains a repeating unit represented by any of the following formula group (7).

[0210] [ka]

[0211] In each polymer of formula group (7), Ar 13 The above 1 Ar 4 This represents multiple Ar in each polymer. 13 The Ar in each polymer may be the same or different, 13 At least one of the Ar 1 X, R 1 , R 2 , R 20 , R 21 , R 22 , R 23 This is the same as in equations (2)-1 and (2)-2 above. 1 , m 1 This represents the molar ratio of repeating units in the polymer.

[0212] [Specific example] Specific examples of the polymers of the present invention are shown below, but the invention is not limited to these examples. The numbers in the chemical formulas represent the molar ratio of repeating units. These polymers may be random copolymers, alternating copolymers, block copolymers, or graft copolymers, and the order of monomer arrangement is not limited.

[0213]

change

[0214]

change

[0215]

change

[0216]

change

[0217]

change

[0218]

change

[0219]

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[0220]

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[0221]

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[0222]

change

[0223]

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[0224] [ka]

[0225] [ka]

[0226] [ka]

[0227] [Method for producing polymers] The method for producing the polymer of the present invention is not particularly limited. The polymer of the present invention can be produced, for example, by polymerization by the Suzuki reaction, the Grignard reaction, the Yamamoto reaction, the Ullmann reaction, the Buchwald-Hartwig reaction, and the like.

[0228] In the polymerization methods by the Ullmann reaction and the Buchwald-Hartwig reaction, for example, the polymer of the present invention is synthesized by reacting an aryl dihalide represented by formula (1a) (where Y represents a halogen atom such as I, Br, Cl, or F) with a primary aminoaryl represented by formula (1b), and then reacting it with a compound represented by formula (2a).

[0229] [ka]

[0230] In the above formula, Ar 1 , R 1 ~R 2 X, g, and i are equivalent to those in equations (2)-1 to (2)-2 above. 1 , m 1 In the chemical formula, the numbers represent the molar ratio of the repeating units. In the polymerization method described above, the reaction that forms the N-aryl bond is usually carried out in the presence of a base such as potassium carbonate, tert-butoxysodium, or triethylamine. Furthermore, the process can also be carried out in the presence of transition metal catalysts, such as copper or palladium complexes.

[0231] <Organic electroluminescent light-emitting material> The polymer of the present invention can be particularly suitably used as an organic electroluminescent material. In other words, the polymer of the present invention is preferably an organic electroluminescent material. Since the polymer of the present invention is a polymer with excellent hole transport properties, it is preferable to use it as a hole transporting material. The polymer of the present invention is typically contained between the anode and the light-emitting layer in an organic field-generating device. That is, it is preferable to use it as a material that forms at least one of the hole injection layer and the hole transport layer, i.e., as a charge transport material. Furthermore, the polymer of the present invention may be included in the light-emitting layer of an organic electroluminescent device. That is, it can be used as a charge transport material included in the light-emitting layer. When used as a charge transport material, the polymer of the present invention may contain one type, or it may contain two or more types in any combination and any ratio.

[0232] When forming at least one of the hole injection layer and the hole transport layer of an organic electroluminescent element using the polymer of the present invention, the content of the polymer of the present invention in the hole injection layer or the hole transport layer is usually 1 to 100% by mass, preferably 5 to 100% by mass, and more preferably 10 to 100% by mass. This range is preferable because it improves the charge transport performance of the hole injection layer or the hole transport layer, reduces the driving voltage, and improves driving stability.

[0233] When the polymer content of the present invention is not 100% by mass in the hole injection layer or hole transport layer, examples of components constituting the hole injection layer or hole transport layer include hole transport compounds and the like, as described later. Furthermore, since organic electroluminescent devices can be easily manufactured, the polymer of the present invention is preferably used in organic layers formed by a wet film deposition method.

[0234] <Composition for Organic Electroluminescent Light-Emitting Devices> The organic electroluminescent element composition of the present invention contains the polymer of the present invention. The organic electroluminescent element composition of the present invention may contain one type of polymer of the present invention, or it may contain two or more types in any combination and any ratio.

[0235] [Polymer content] The content of the above polymer in the organic electroluminescent element composition of the present invention is typically 0.01 to 70% by mass, preferably 0.1 to 60% by mass, and more preferably 0.5 to 50% by mass. Within the above range is preferable because it makes it less likely for defects to occur in the formed organic layer and less likely for film thickness to be uneven. Furthermore, the organic electroluminescent element composition of the present invention may contain solvents and other elements in addition to the polymer described above.

[0236] [solvent] The organic electroluminescent element composition of the present invention typically contains a solvent. This solvent is preferably one that dissolves the polymer. Specifically, a solvent that dissolves the polymer at a concentration of typically 0.05% by mass or more, preferably 0.5% by mass or more, and more preferably 1% by mass or more, at room temperature is preferred.

[0237] Specific examples of solvents include aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene; halogen-containing solvents such as 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole; aliphatic ester solvents such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, isopropyl benzoate, propyl benzoate, and n-butyl benzoate; and other organic solvents used in the hole injection layer formation composition and hole transport layer formation composition described later. Furthermore, one type of solvent may be used, or two or more types may be used in any combination and ratio.

[0238] In particular, the solvent contained in the organic electroluminescent element composition of the present invention is preferably a solvent whose surface tension at 20°C is typically less than 40 dyn / cm, preferably 36 dyn / cm or less, and more preferably 33 dyn / cm or less.

[0239] When forming a coating film by a wet deposition method using the organic electroluminescent element composition of the present invention, and crosslinking the polymer to form an organic layer, it is preferable that the solvent has high affinity to the substrate. This is because the uniformity of the film quality greatly affects the uniformity and stability of the light emission of the organic electroluminescent element. Therefore, the organic electroluminescent element composition used in the wet deposition method is required to have low surface tension so that it can form a coating film with higher leveling properties and uniformity. Thus, it is preferable to use a solvent having such low surface tension so that a uniform layer containing the polymer can be formed, and consequently a uniform crosslinked layer can be formed.

[0240] Specific examples of solvents with low surface tension include aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene mentioned above, ester solvents such as ethyl benzoate, ether solvents such as anisole, trifluoromethoxyanisole, pentafluoromethoxybenzene, 3-(trifluoromethyl)anisole, and ethyl (pentafluorobenzoate).

[0241] On the other hand, the solvent contained in the organic electroluminescent element composition of the present invention is preferably one whose vapor pressure at 25°C is typically 10 mmHg or less, preferably 5 mmHg or less, and typically 0.1 mmHg or more. By using such a solvent, it is possible to prepare an organic electroluminescent element composition that is suitable for a process of manufacturing organic electroluminescent elements by a wet film deposition method and is suitable for the properties of the polymer of the present invention. Specific examples of such solvents include aromatic solvents such as toluene, xylene, and mesitylene, as well as ether solvents and ester solvents.

[0242] Incidentally, moisture can cause performance degradation of organic electroluminescent devices, and in particular can accelerate the decrease in brightness during continuous operation. Therefore, in order to reduce the amount of moisture remaining during wet film formation as much as possible, among the solvents mentioned above, those in which the solubility of water at 25°C is 1% by mass or less are preferred, and solvents in which the solubility of water is 0.1% by mass or less are more preferred.

[0243] The solvent content in the organic electroluminescent element composition of the present invention is usually 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 80% by mass or more. By having a solvent content above the lower limit mentioned above, the flatness and uniformity of the formed layer can be improved.

[0244] [Electron-accepting compounds] The organic electroluminescent element composition of the present invention preferably further contains an electron-accepting compound in order to reduce resistance. In particular, when the organic electroluminescent element composition of the present invention is used to form a hole injection layer, it is preferable to include an electron-accepting compound.

[0245] As electron-accepting compounds, compounds that have oxidizing power and the ability to accept one electron from the polymer are preferred. Specifically, compounds with an electron affinity of 4 eV or more are preferred, and compounds with an electron affinity of 5 eV or more are more preferred.

[0246] 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.

[0247] Specifically, examples include onium salts with substituted organic groups such as 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl) borate and triphenylsulfonium tetrafluoroborate (International Publication No. 2005 / 089024, International Publication No. 2017 / 164268); high-valence inorganic compounds such as iron(III) chloride (Japanese Patent Publication No. 11-251067) and ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris(pentafluorophenyl)borane (Japanese Patent Publication No. 2003-31365); fullerene derivatives and iodine.

[0248] The organic electroluminescent element composition of the present invention may contain one of the above-mentioned electron-accepting compounds alone, or it may contain two or more in any combination and ratio.

[0249] When the organic electroluminescent element composition of the present invention contains an electron-accepting compound, the content of the electron-accepting compound is usually 0.0005% by mass or more, preferably 0.001% by mass or more, usually 20% by mass or less, preferably 10% by mass or less. Furthermore, the content of the electron-accepting compound relative to the polymer in the organic electroluminescent element composition is usually 0.5% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, usually 80% by mass or less, preferably 60% by mass or less, and even more preferably 40% by mass or less.

[0250] It is preferable that the content of the electron-accepting compound in the composition for organic electroluminescent elements is above the lower limit above, as this allows the electron acceptor to accept electrons from the polymer, resulting in a lower resistance of the formed organic layer. It is also preferable that the content is below the upper limit above, as this makes it less likely for defects to occur in the formed organic layer and less likely for film thickness to be uneven.

[0251] [Cationic radical compounds] The organic electroluminescent element composition of the present invention may further contain a cationic radical compound. As the cationic radical compound, an ionic compound consisting of a cationic radical, which is a chemical species obtained by removing one electron from a hole-transporting compound, and a counter anion is preferred. However, if the cationic radical is derived from a hole-transporting polymer compound, the cationic radical will have a structure obtained by removing one electron from the repeating unit of the polymer compound.

[0252] Furthermore, the cation radical is preferably a species obtained by removing one electron from a hole-transporting compound, as described later. It is preferable that the cation radical be a species obtained by removing one electron from a preferred hole-transporting compound, from the viewpoints of amorphousness, visible light transmittance, heat resistance, and solubility.

[0253] Here, a cationic radical compound can be generated by mixing a hole-transporting compound (described later) with the aforementioned electron-accepting compound. That is, by mixing the hole-transporting compound and the electron-accepting compound, electron transfer occurs from the hole-transporting compound to the electron-accepting compound, generating a cationic ion compound consisting of the cationic radical and counter anion of the hole-transporting compound.

[0254] When the organic electroluminescent element composition of the present invention contains a cationic radical compound, the content of the cationic radical compound in the organic electroluminescent element composition is usually 0.0005% by mass or more, preferably 0.001% by mass or more, and usually 40% by mass or less, preferably 20% by mass or less. It is preferable that the content of the cationic radical compound is above the lower limit because it results in a low-resistance organic layer, and it is preferable that it is below the upper limit because it is less likely to cause defects in the organic layer and less likely to cause uneven film thickness.

[0255] In addition to the components described above, the organic electroluminescent element composition of the present invention may also contain components found in the hole injection layer forming composition and the hole transport layer forming composition described later, in the amounts described later.

[0256] <Luminescent layer material> In an organic electroluminescent device using the polymer of the present invention as a charge-transporting material forming at least one of a hole injection layer and a hole transport layer, the light-emitting layer comprises a light-emitting material and a host material. The light-emitting material can be either a phosphorescent material or a fluorescent material.

[0257] In an organic electroluminescent device using the polymer of the present invention as a charge transport material forming at least one of a hole injection layer and a hole transport layer, if the light-emitting layer is a phosphorescent light-emitting layer, the following materials are preferred as the phosphorescent light-emitting material.

[0258] [Phosphorescent materials] Phosphorescent materials are materials that exhibit light emission from an excited triplet state. Typical examples include metal complex compounds containing Ir, Pt, Eu, etc., and materials with a metal complex structure are preferred.

[0259] 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-period periodic table (hereinafter, unless otherwise specified, "periodic table" refers to the long-period periodic table) as the central metal. As such phosphorescent materials, compounds represented by formula (201) or formula (202) are preferred, and compounds represented by formula (201) are more preferred.

[0260] [ka]

[0261] In equation (201), M is a metal selected from groups 7-11 of the periodic table, such as ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, and europium.

[0262] Ring A1 represents an aromatic hydrocarbon ring structure or an aromatic heterocyclic structure that may have substituents. Ring A2 represents an aromatic heterocyclic structure that may have substituents.

[0263] R 201 , R 202 Each of these is an independent structure represented by the above formula (202), and "*" indicates bonding with ring A1 and / or ring A2. 201 , R 202 R can be the same or different, 201 , R 202 If there are multiple instances of each, they may be the same or different.

[0264] Ar 201 Ar203 Each of these independently represents an aromatic hydrocarbon structure which may have substituents, or an aromatic heterocyclic structure which may have substituents. Ar 202 This represents an optionally substituted aromatic hydrocarbon structure, an optionally substituted aromatic heterocyclic structure, or an optionally substituted aliphatic hydrocarbon structure.

[0265] Substituents bonded to ring A1 may bond to each other, substituents bonded to ring A2 may bond to each other, or substituents bonded to ring A1 and substituents bonded to ring A2 may bond to each other to form a ring.

[0266] B 201 -L 200 -B 202 This represents an anionic bidentate ligand. 201 and B 202 Each of these independently represents a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may be atoms that constitute a ring. 200 is a single bond, or B 201 and B 202 B represents the group of atoms that together constitute a bidentate ligand. 201 -L 200 -B 202 If multiple instances exist, they may be identical or different.

[0267] i1 and i2 each independently represent integers between 0 and 12 (inclusive). i3 is Ar 202 It is a non-negative integer, with the upper limit being the number of values ​​that can be substituted for it. j1 is Ar 201 It is a non-negative integer, with the upper limit being the number of values ​​that can be substituted for it. k1 and k2 are non-negative integers, each independently, with the upper limit being the number of permutations in rings A1 and A2, respectively. m1 is an integer between 1 and 3.

[0268] <Substituent group Z´> Alkyl alkyl groups, preferably C1 to C20 alkyl groups, more preferably C1 to C12 alkyl groups, even more preferably C1 to C8 alkyl groups, and particularly preferably C1 to C6 alkyl groups. • Alkoxy groups, preferably alkoxy groups having 1 to 20 carbon atoms, more preferably alkoxy groups having 1 to 12 carbon atoms, and even more preferably alkoxy groups having 1 to 6 carbon atoms. • An 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, and particularly preferably an aryloxy group having 6 carbon atoms. A 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. • An arylamino group, preferably an arylamino group having 6 to 36 carbon atoms, more preferably an arylamino group having 6 to 24 carbon atoms. Aralkyl groups, preferably aralkyl groups having 7 to 40 carbon atoms, more preferably aralkyl groups having 7 to 18 carbon atoms, and even more preferably aralkyl groups having 7 to 12 carbon atoms. • Heteroaralkyl groups, preferably heteroaralkyl groups having 7 to 40 carbon atoms, more preferably heteroaralkyl groups having 7 to 18 carbon atoms. Alkenyl groups, preferably alkenyl groups having 2 to 20 carbon atoms, more preferably alkenyl groups having 2 to 12 carbon atoms, even more preferably alkenyl groups having 2 to 8 carbon atoms, and particularly preferably alkenyl groups 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. • An aryl group, preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 24 carbon atoms, even more preferably an aryl group having 6 to 18 carbon atoms, and particularly preferably an aryl group having 6 to 14 carbon atoms. Heteroaryl groups, preferably heteroaryl groups having 3 to 30 carbon atoms, more preferably heteroaryl groups having 3 to 24 carbon atoms, even more preferably heteroaryl groups having 3 to 18 carbon atoms, and particularly preferably heteroaryl groups having 3 to 14 carbon atoms. • Alkylsilyl group, preferably an alkylsilyl group having 1 to 20 carbon atoms in the alkyl group, more preferably an alkylsilyl group having 1 to 12 carbon atoms in the alkyl group. • An 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. Hydrogen atom, deuterium atom, fluorine atom, cyano group, or -SF5.

[0269] The above groups may have one or more hydrogen atoms replaced by fluorine atoms, or one or more hydrogen atoms replaced by deuterium atoms.

[0270] (Preferred group among substituent group Z') Of these substituent groups Z', Preferably, alkyl groups, alkoxy groups, aryloxy groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkylsilyl groups, arylsilyl groups, and groups in which one or more hydrogen atoms of these groups are replaced by fluorine atoms, fluorine atoms, cyano groups, or -SF5. More preferably alkyl groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, and groups in which one or more hydrogen atoms of these groups are replaced by fluorine atoms, fluorine atoms, cyano groups, or -SF5. More preferably, alkyl groups, alkoxy groups, aryloxy groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkylsilyl groups, and arylsilyl groups. Particularly preferred are alkyl groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, and heteroaryl groups. Most preferably, the group is an alkyl group, an arylamino group, an aralkyl group, an aryl group, or a heteroaryl group.

[0271] (Substituents to be substituted for Z') These substituent groups Z' may further contain substituents selected from substituent group Z. The preferred groups, more preferred groups, even more preferred groups, particularly preferred groups, and most preferred groups of the substituents that may be present are the same as the preferred groups in substituent group Z'.

[0272] (Ring A1) Ring A1 represents an aromatic hydrocarbon ring structure or an aromatic heterocyclic structure that may have substituents.

[0273] The aromatic hydrocarbon ring of ring A1 is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms, and specifically, a benzene ring, naphthalene ring, anthracene ring, triphenylyl ring, acenaphthene ring, fluorantene ring, or fluorene ring is preferred.

[0274] The aromatic heterocycle of ring A1 is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom, and more preferably a furan ring, a benzofuran ring, a thiophene ring, or a benzothiophene ring.

[0275] More preferably, ring A1 is 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.

[0276] (ring A2) Ring A2 represents an aromatic heterocyclic structure that may have substituents.

[0277] The aromatic heterocycle of ring A2 is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specifically, examples include pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, imidazole rings, oxazole rings, thiazole rings, benzothiazole rings, benzoxazole rings, benzimidazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, naphthyridine rings, and phenanthridine rings. More preferably, the rings are pyridine rings, pyrazine rings, pyrimidine rings, imidazole rings, benzothiazole rings, benzoxazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, and quinazoline rings; more preferably, the rings are pyridine rings, imidazole rings, benzothiazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, and quinazoline rings; and most preferably, the rings are pyridine rings, imidazole rings, benzothiazole rings, quinoline rings, quinoxaline rings, and quinazoline rings.

[0278] Preferred combinations of ring A1 and ring A2, when denoted as (ring A1-ring A2), are (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).

[0279] (Substituents of ring A1 and ring A2) The substituents that rings A1 and A2 may have can be arbitrarily selected, but preferably one or more substituents selected from the substituent group Z'.

[0280] (Ar 201 Ar 202 Ar 203 ) Ar 201 Ar 203 Each of these independently represents an aromatic hydrocarbon ring structure that may have substituents, or an aromatic heterocyclic ring structure that may have substituents. Ar 202This represents an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic structure, or an optionally substituted aliphatic hydrocarbon structure.

[0281] (Ar 201 Ar 202 Ar 203 (Aromatic hydrocarbon ring) Ar 201 Ar 202 Ar 203 In the case of an aromatic hydrocarbon structure in which any of the elements may have substituents, the aromatic hydrocarbon structure is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms, specifically a benzene ring, naphthalene ring, anthracene ring, triphenylyl ring, acenaphthene ring, fluorantene ring, or fluorene ring, more preferably a benzene ring, naphthalene ring, or fluorene ring, and most preferably a benzene ring.

[0282] (Fluorescent 9, 9') Ar 201 Ar 202 Ar 203 If either of the elements is a fluorene ring which may have substituents, it is preferable that the 9th and 9' positions of the fluorene ring have substituents or are bonded to adjacent structures.

[0283] (o-, m-phenylene) Ar 201 Ar 202 If any of the elements is a benzene ring which may have substituents, it is preferable that at least one benzene ring is bonded to an adjacent structure at the ortho or meta position, and more preferably that at least one benzene ring is bonded to an adjacent structure at the meta position.

[0284] (Ar 201 Ar 202 Ar 203 (Aromatic heterocycle) Ar 201 Ar 202 Ar 203In the case of an aromatic heterocyclic structure in which any of the atoms may have substituents, the aromatic heterocyclic structure is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms and containing a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specifically, examples include pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, imidazole rings, oxazole rings, thiazole rings, benzothiazole rings, benzoxazole rings, benzimidazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, naphthyridine rings, phenantholidine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings. More preferably, the pyridine rings, pyrimidine rings, triazine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings.

[0285] (N position of carbazole) Ar 201 Ar 202 Ar 203 If either of the elements is a carbazole ring which may have substituents, it is preferable that the N-position of the carbazole ring has a substituent or is bonded to an adjacent structure.

[0286] (Ar 202 (Aliphatic hydrocarbons) Ar 202 If the aliphatic hydrocarbon structure may have substituents, it is a linear, branched, or cyclic aliphatic hydrocarbon structure, preferably having 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, and even more preferably 1 to 8 carbon atoms.

[0287] (Preferred ranges for i1 and i2) i1 represents an integer between 0 and 12, preferably between 1 and 12, more preferably between 1 and 8, and more preferably between 1 and 6. This range is expected to improve solubility and charge transport.

[0288] (Preferred range for i3) i3 preferably represents an integer between 0 and 5, more preferably between 0 and 2, and more preferably 0 or 1.

[0289] (Preferred range of j1) j1 preferably represents an integer between 0 and 2, and more preferably 0 or 1.

[0290] (Preferred ranges for k1 and k2) k1 and k2 preferably represent integers between 0 and 3, more preferably between 1 and 3, more preferably 1 or 2, and particularly preferably 1.

[0291] (Ar 201 Ar 202 Ar 203 Preferred substituents) Ar 201 Ar 202 Ar 203 The substituents that may be present can be arbitrarily selected, but preferably one or more substituents selected from the substituent group Z', and the preferred groups are also as shown in substituent group Z', but more preferably a hydrogen atom, an alkyl group, or an aryl group, particularly preferably a hydrogen atom, an alkyl group, and most preferably unsubstituted (hydrogen atom).

[0292] (Preferred structure of formula (201)) Among the structures represented by formula (201) above, the following structure is preferred.

[0293] (Phenylene coupled type) A structure having a group in which benzene rings are linked. That is, Ar 201 The structure is a benzene ring, i1 is 1 to 6, and at least one of the benzene rings is bonded to an adjacent structure at the ortho or meta position. This structure is expected to improve solubility and charge transport.

[0294] ((phenylene)-(aralkyl)-(alkyl)) A structure having an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or aralkyl group is bonded to ring A1 or ring A2. That is, Ar 201is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, i1 is 1 to 6, Ar 202 The structure is an aliphatic hydrocarbon, i2 is 1 to 12, preferably 3 to 8, Ar 203 The structure is a benzene ring, and i3 is 0 or 1. Preferably, Ar 201 The structure is the aforementioned aromatic hydrocarbon structure, more preferably a structure in which 1 to 5 benzene rings are linked, and more preferably a single benzene ring. This structure is expected to improve solubility and charge transport.

[0295] (Dendron) A structure in which a dendron is bonded to ring A1 or ring A2. For example, Ar 201 Ar 202 The benzene ring structure, Ar 203 The structure is biphenyl or terphenyl, with i1 and i2 being 1-6, i3 being 2, and j being 2. This structure is expected to improve solubility and charge transport.

[0296] (B 201 -L 200 -B 202 ) B 201 -L 200 -B 202 This represents an anionic bidentate ligand. 201 and B 202 Each of these independently represents a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may be atoms that constitute a ring. 200 is a single bond, or B 201 and B 202 B represents the group of atoms that together constitute a bidentate ligand. 201 -L 200 -B 202 If multiple instances exist, they may be identical or different. B 201 -L 200 -B 202 Among the structures represented by the formulas, the structure represented by the following formulas (203) or (204) is preferred.

[0297] [ka]

[0298] In formula (203), R 211 , R 212 , R 213 represents a substituent. The substituents can be arbitrarily selected, but preferably one or more substituents selected from the substituent group Z'.

[0299] [ka]

[0300] In formula (204), ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom, which may have substituents. Ring B3 is preferably a pyridine ring.

[0301] The substituents that ring B3 may have are not particularly limited, but preferably one or more substituents selected from the substituent group Z'.

[0302] (Preferred phosphorescent material represented by formula (201)) The phosphorescent material represented by equation (201) is not particularly limited, but the following structures are examples.

[0303] [ka]

[0304] [ka]

[0305] [ka]

[0306] [ka]

[0307] [ka]

[0308] (The compound represented by formula (205)) Furthermore, as the phosphorescent material, a compound represented by the following formula (205) is preferred.

[0309] [ka]

[0310] In formula (205), M 2 R represents a metal, and T represents a carbon or nitrogen atom. 92 ~R 95 Each of these independently represents a substituent. However, if T is a nitrogen atom, then R 94 and R 95 There isn't one.

[0311] In formula (205), M 2 represents a metal. Specific examples include the metals mentioned above, selected from groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold are preferred, and divalent metals such as platinum and palladium are particularly preferred.

[0312] Also, in equation (205), R 92 and R 93 Each of these 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.

[0313] Furthermore, if T is a carbon atom, R 94 and R 95 Each of them independently, R 92 and R93 This represents substituents represented by similar examples. Furthermore, if T is a nitrogen atom, R is directly bonded to T. 94 or R 95 It does not exist.

[0314] Also, R 92 ~R 95 It may further have substituents. The substituents can be the substituents mentioned above. Furthermore, R 92 ~R 95 Any two or more of these groups may be linked together to form a ring.

[0315] (Molecular weight of phosphorescent material) The molecular weight of the phosphorescent material is preferably 5000 or less, more preferably 4000 or less, and particularly preferably 3000 or less. Furthermore, the molecular weight of the phosphorescent material is usually 800 or more, preferably 1000 or more, and more preferably 1200 or more. This molecular weight range allows the phosphorescent materials to mix uniformly with the charge transport material without agglomerating, resulting in a highly efficient luminescent layer.

[0316] A large molecular weight is preferable for phosphorescent materials because it results in high Tg, melting point, and decomposition temperature, providing excellent heat resistance for the phosphorescent material and the formed luminescent layer, and reducing the likelihood of deterioration of film quality due to gas generation, recrystallization, and molecular migration, as well as an increase in impurity concentration due to thermal decomposition of the material. On the other hand, a small molecular weight is preferable for phosphorescent materials because it facilitates the purification of organic compounds.

[0317] [Host Materials] In an organic electroluminescent device using a polymer, which is one embodiment of the present invention, as a charge transport material forming at least one of a hole injection layer and a hole transport layer, if the light-emitting layer is a phosphorescent material, the following materials are preferred as the host material.

[0318] <Host Materials> The host material of the light-emitting layer is a material having a framework with excellent charge transport properties, and is preferably selected from electron-transporting materials, hole-transporting materials, and bipolar materials capable of transporting both electrons and holes.

[0319] (A skeleton with excellent charge transport properties) Examples of skeletons with excellent charge transport properties include aromatic structures, aromatic amine structures, triarylamine structures, dibenzofuran structures, naphthalene structures, phenanthrene structures, phthalocyanine structures, porphyrin structures, thiophene structures, benzylphenyl structures, fluorene structures, quinacridone structures, triphenylene structures, carbazole structures, pyrene structures, anthracene structures, phenanthroline structures, quinoline structures, pyridine structures, pyrimidine structures, triazine structures, oxadiazole structures, or imidazole structures.

[0320] (electron transport material) As an electron transport material, from the viewpoint of having excellent electron transport properties and a relatively stable structure, compounds having pyridine, pyrimidine, or triazine structures are more preferred, and compounds having pyrimidine or triazine structures are even more preferred.

[0321] (Hole transport material) A hole-transporting material is a compound having a structure that exhibits excellent hole transport properties. Among the central skeletons exhibiting excellent charge transport properties, a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure, or a pyrene structure is preferred as a structure with excellent hole transport properties, and a carbazole structure, a dibenzofuran structure, or a triarylamine structure is even more preferred. Furthermore, the polymer of the present invention can also be used as a hole transport material contained in the light-emitting layer.

[0322] (Condensed ring structure with 3 or more rings) The host material of the light-emitting layer is preferably a compound having a fused ring structure of three or more rings, and more preferably a compound having two or more fused ring structures of three or more rings, or a compound having at least one fused ring structure of five or more rings. These compounds increase the rigidity of the molecules, making it easier to suppress the degree of molecular motion that responds to heat. Furthermore, it is preferable for the fused rings of three or more rings and the fused rings of five or more rings to have aromatic hydrocarbon rings or aromatic heterocycles, in terms of charge transport properties and material durability.

[0323] Examples of fused ring structures with three or more rings include anthracene structures, phenanthrene structures, pyrene structures, chrysene structures, naphthacene structures, triphenylene structures, fluorene structures, benzofluorene structures, indenofluorene structures, indolofluorene structures, carbazole structures, indenocarbazole structures, indolocarbazole structures, dibenzofuran structures, and dibenzothiophene structures.

[0324] From the viewpoint of charge transport 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, and from the viewpoint of resistance to electric charge, the carbazole structure or indolocarbazole structure is more preferred.

[0325] In the present invention, from the viewpoint of the durability of the organic electroluminescent element against charge, it is preferable that at least one of the host materials of the light-emitting layer is a material having a pyrimidine skeleton or a triazine skeleton.

[0326] (Molecular weight range) The host material of the light-emitting layer is preferably a polymer material from the viewpoint of excellent flexibility. A light-emitting layer formed using a material with excellent flexibility is preferred as a light-emitting layer for an organic electroluminescent device formed on a flexible substrate. When the host material contained in the light-emitting layer is a polymer material, the molecular weight is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and more preferably 10,000 to 100,000.

[0327] Furthermore, the host material of the light-emitting layer is preferably low molecular weight from the viewpoint 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, most preferably 2,000 or less, usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0328] [Fluorescent-emitting layer material] In an organic electroluminescent device using the polymer of the present invention as a charge transport material forming at least one of a hole injection layer and a hole transport layer, if the light-emitting layer is a fluorescent light-emitting layer material, it is preferable that it is the following blue fluorescent light-emitting layer material.

[0329] (Blue fluorescent emitting layer material) The blue fluorescent emitting layer material is not particularly limited, but compounds represented by the following formula (211) are preferred.

[0330] [ka]

[0331] In the above equation (211), Ar 241 represents an aromatic hydrocarbon condensed ring structure which may have substituents, and Ar 242 Ar 243Each of these independently represents an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, or a group formed by the bonding or condensation of these. n41 is an integer from 1 to 4.

[0332] Ar 241 Preferably, it represents an aromatic hydrocarbon condensed ring structure having 10 to 30 carbon atoms, and specific examples of such structures include naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, fluorantene, pyrene, tetracene, chrysene, and perylene. More preferably, it represents an aromatic hydrocarbon condensed ring structure having 12 to 20 carbon atoms, and specific examples of such structures include acenaphthene, fluorene, anthracene, phenanthrene, fluorantene, pyrene, tetracene, chrysene, and perylene. Even more preferably, it represents an aromatic hydrocarbon condensed ring structure having 16 to 18 carbon atoms, and specific examples of such structures include fluorantene, pyrene, and chrysene.

[0333] Ar 242 Ar 243 The alkyl group in is preferably a linear, branched, or cyclic alkyl group, which may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the blue fluorescent emitting layer material, the number of carbon atoms is preferably 1 to 6, and more preferably 3 or less. The alkyl group is even more preferably a methyl group, an ethyl group, or a tert-butyl group.

[0334] Ar 242 Ar 243 They can be the same or different. 242 Ar 243Preferably, represents an aromatic hydrocarbon ring structure having 6 to 18 carbon atoms or a group formed by bonding or condensing these rings. Specific examples of such structures include benzene rings, biphenyl rings, ta-phenyl rings, naphthalene rings, fluorene rings, dibenzothiophene rings, dibenzofuran rings, carbazole rings, triphenylene rings, and perylene rings. More preferably, it represents an aromatic hydrocarbon ring structure having 6 to 12 carbon atoms or a group formed by bonding or condensing these rings. Preferably, it represents an aromatic hydrocarbon ring structure having 12 carbon atoms or a group formed by condensing these rings. Specific examples of such structures include fluorene rings, dibenzothiophene rings, dibenzofuran rings, and carbazole rings.

[0335] n41 is an integer between 1 and 4, preferably between 1 and 3, more preferably between 1 and 2, and most preferably 2.

[0336] (Ar 241 Ar 242 Ar 243 (substituents of) Ar 241 Ar 242 Ar 243 The substituents that may be present are preferably groups selected from the substituent group Z', more preferably hydrocarbon groups included in substituent group Z', and even more preferably hydrocarbon groups among the groups preferred by substituent group Z'.

[0337] (Host material for blue fluorescent emitting layer) In an organic electroluminescent device using the polymer of the present invention as a charge transport material forming at least one of a hole injection layer and a hole transport layer, if the light-emitting layer is a phosphorescent material, the following materials are preferred as the host material. The host material for the blue fluorescent emitting layer is not particularly limited, but compounds represented by the following formula (212) are preferred.

[0338] [ka]

[0339] In the above equation (212), R 241 , R 242 Each of these is independently represented by the following equation (213), and R 243 R represents a substituent, 243 If there are multiple values, they may be the same or different, and n43 is an integer between 0 and 8.

[0340] [ka]

[0341] Ar 244 Ar 245 Each independently represents an aromatic hydrocarbon structure which may have substituents, or a heteroaromatic ring structure which may have substituents, and Ar 244 Ar 245 If there are multiple instances of each, they may be the same or different, n44 is an integer from 1 to 5, and n45 is an integer from 0 to 5.

[0342] Ar 244 Preferably, it is an aromatic hydrocarbon structure having 6 to 30 carbon atoms and being a monocyclic or fused ring, and may have substituents; more preferably, it is an aromatic hydrocarbon structure having 6 to 12 carbon atoms and being a monocyclic or fused ring, and may have substituents.

[0343] Ar 245 Preferably, it is an aromatic hydrocarbon structure having 6 to 30 carbon atoms and being a monocyclic or fused ring, or an aromatic heterocyclic structure having 6 to 30 carbon atoms and being a fused ring, and more preferably, it is an aromatic hydrocarbon structure having 6 to 12 carbon atoms and being a monocyclic or fused ring, or an aromatic heterocyclic structure having 12 carbon atoms and being a fused ring, or being a fused ring, being a fused ring, being 12 carbon atoms, and being substituted.

[0344] n44 is preferably 1 to 3, more preferably 1 or 2, and n45 is preferably 0 to 3, more preferably 0 to 2.

[0345] (R 243 Ar 244 Ar 245 (substituents of) R is a substituent. 243 And, Ar 244 and Ar 245 The substituents that may be present are preferably groups selected from the substituent group Z', more preferably hydrocarbon groups included in substituent group Z', and even more preferably hydrocarbon groups among the groups preferred by substituent group Z'.

[0346] (molecular weight) The molecular weight of the light-emitting material and host material for the blue fluorescent light-emitting layer is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, most preferably 2,000 or less, usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0347] <Organic electroluminescent element> The present invention relates to an organic electroluminescent element having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode, wherein the organic layer includes a layer formed by a wet film deposition method using an organic electroluminescent element composition containing the polymer.

[0348] In the organic electroluminescent element of the present invention, the layer formed by the wet deposition method is preferably at least one of a hole injection layer and a hole transport layer, and in particular, it is preferable that this organic layer comprises a hole injection layer, a hole transport layer and a light-emitting layer, and that all of these hole injection layer, hole transport layer and light-emitting layer are layers formed by the wet deposition method.

[0349] In the present invention, a wet film formation method refers to a method in which a film is formed using a wet method, such as spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet, nozzle printing, screen printing, gravure printing, or flexographic printing, and the resulting coated film is dried to form a film. Among these film formation methods, spin coating, spray coating, inkjet, and nozzle printing are preferred.

[0350] As an example of the structure of the organic electroluminescent element of the present invention, Figure 1 shows a schematic diagram (cross-section) of an example of the structure of an organic electroluminescent element 10. In Figure 1, 1 represents the substrate, 2 the anode, 3 the hole injection layer, 4 the hole transport layer, 5 the light-emitting layer, 6 the hole blocking layer, 7 the electron transport layer, 8 the electron injection layer, and 9 the cathode. Hereinafter, an example of an embodiment of the layer structure of an organic electroluminescent element and its general formation method will be described with reference to Figure 1.

[0351] [substrate] The substrate 1 serves as a support for the organic electroluminescent element, and is typically made of quartz, glass, metal, plastic film, or sheet. Of these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferred. The substrate should preferably be made of a material with high gas barrier properties to prevent degradation of the organic electroluminescent element by the outside air. Therefore, especially when using a material with low gas barrier properties, such as a synthetic resin substrate, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve its gas barrier properties.

[0352] [anode] Anode 2 is responsible for injecting holes into the layer on the light-emitting layer 5 side. Anode 2 is typically composed of metals such as aluminum, gold, silver, nickel, palladium, and platinum; metal oxides such as indium and / or tin oxides; metal halides such as copper iodide; carbon black; and conductive polymers such as poly(3-methylthiophene), polypyrrole, and polyaniline.

[0353] The formation of anode 2 is usually carried out by dry methods such as sputtering or vacuum deposition. When forming the anode using metal nanoparticles such as silver, nanoparticles such as copper iodide, carbon black, conductive metal oxide nanoparticles, or conductive polymer fine powder, it can also be formed by dispersing them in a suitable binder resin solution and coating it onto a substrate. In the case of conductive polymers, the anode can also be formed by directly forming a thin film on the substrate by electrolytic polymerization, or by coating the substrate with conductive polymer (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0354] Anode 2 is usually a single-layer structure, but may be a multilayer structure as appropriate. If anode 2 is a multilayer structure, different conductive materials may be laminated on the first layer of anode.

[0355] The thickness of anode 2 should be determined according to the required transparency and material. When particularly high transparency is required, a thickness that allows for a visible light transmittance of 60% or more is preferable, and a thickness that allows for a transmittance of 80% or more is even more preferable. The thickness of anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, if transparency is not required, the thickness of anode 2 can be arbitrarily set according to the required strength, etc., and in this case, anode 2 may be the same thickness as the substrate.

[0356] When depositing other layers on the surface of anode 2, it is preferable to remove impurities from anode 2 and adjust its ionization potential to improve hole injection properties by treating it with ultraviolet / ozone, oxygen plasma, argon plasma, etc., before deposition.

[0357] [Hole injection layer] The layer responsible for transporting holes from the anode 2 to the light-emitting layer 5 is usually called a hole injection transport layer or hole transport layer. When there are two or more layers responsible for transporting holes from the anode 2 to the light-emitting layer 5, the layer closer to the anode is sometimes called the hole injection layer 3. It is preferable to form the hole injection layer 3 because it enhances the function of transporting holes from the anode 2 to the light-emitting layer 5. When forming the hole injection layer 3, it is usually formed on the anode 2.

[0358] 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. The hole injection layer can be formed by either vacuum deposition or wet deposition. However, wet deposition is preferable for forming the hole injection layer due to its superior film-forming properties.

[0359] The hole injection layer 3 preferably contains a hole transport compound, and more preferably contains both a hole transport compound and an electron acceptor compound. Furthermore, it is preferable that the hole injection layer contains a cationic radical compound, and particularly preferable that it contains both a cationic radical compound and a hole transport compound.

[0360] A general method for forming a hole injection layer is described below, but in the organic electroluminescent device of the present invention, it is preferable that the hole injection layer is formed by a wet film deposition method using the organic electroluminescent device composition.

[0361] [Hole transport compounds] Compositions for forming hole injection layers typically contain a hole-transporting compound that forms the hole injection layer 3. Furthermore, in the case of wet film deposition, a solvent is usually also included. The hole injection layer formation composition preferably has high hole transportability, allowing for efficient transport of injected holes. Therefore, it is preferable that the hole mobility is high and that trapping impurities are less likely to be generated during manufacturing or use. Furthermore, it is preferable that the hole injection layer has excellent stability, a low ionization potential, and high transparency to visible light. In particular, when the hole injection layer is in contact with the light-emitting layer, it is preferable that it does not quench the light emitted from the light-emitting layer or that it does not form an exciplex with the light-emitting layer, thereby reducing the luminescence efficiency.

[0362] As hole-transporting compounds, compounds having an ionization potential of 4.5 eV to 6.0 eV are preferred from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of hole-transporting compounds include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which tertiary amines are linked by fluorene groups, hydrazone compounds, silazane compounds, quinacridone compounds, and the like.

[0363] Of the example compounds described above, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, from the viewpoint of amorphousness and visible light transmittance. Here, 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.

[0364] The type of aromatic tertiary amine compound is not particularly limited, but it is preferable to use a polymer compound (polymerized compound with repeating units) with a weight-average molecular weight of 1,000 or more and 1,000,000 or less, as this makes it easier to obtain uniform luminescence due to the surface smoothing effect.

[0365] The hole injection layer 3 preferably contains the aforementioned electron-accepting compound or the aforementioned cationic radical compound, as the conductivity of the hole injection layer can be improved by oxidation of the hole-transporting compound.

[0366] Cationic 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) can also be generated by oxidative polymerization (dehydrogenation polymerization).

[0367] Oxidative polymerization, as used here, involves chemically or electrochemically oxidizing monomers in an acidic solution using peroxodisulfate or the like. In this oxidative polymerization (dehydrogenation polymerization), the monomers are oxidized to form polymers, and at the same time, cationic radicals are generated, which have one electron removed from the repeating units of the polymer, with an anion from the acidic solution acting as a counter-anion.

[0368] [Formation of hole injection layer by wet deposition method] When forming the hole injection layer 3 by a wet film deposition method, the material to be the hole injection layer is usually mixed with a soluble solvent (solvent for the hole injection layer) to prepare a film deposition composition (composition for forming the hole injection layer). This composition is then applied to the layer corresponding to the layer below the hole injection layer (usually the anode), deposited, and dried to form the layer.

[0369] The concentration of the hole transporting compound in the hole injection layer forming composition is arbitrary as long as it does not significantly impair the effects of the present invention. However, a lower concentration is preferable in terms of uniformity of film thickness, while a higher concentration is preferable in terms of preventing defects from occurring in the hole injection layer. Specifically, the concentration is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.5% by mass or more. On the other hand, the concentration is preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

[0370] Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

[0371] Examples of ether-based solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA), and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

[0372] Examples of ester solvents include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

[0373] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene.

[0374] Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide. In addition to these, dimethyl sulfoxide and the like can also be used.

[0375] The hole injection layer 3 is typically formed by a wet deposition method, which involves preparing a hole injection layer formation composition, coating it onto the layer below the hole injection layer 3 (usually the anode 2), and then drying it. The hole injection layer 3 is typically dried after film formation by heating or reduced-pressure drying.

[0376] [Formation of hole injection layer by vacuum deposition method] When forming the hole injection layer 3 by vacuum deposition, typically one or more of the constituent materials of the hole injection layer 3 (such as the aforementioned hole transporting compound and electron-accepting compound) are placed in a crucible set up inside a vacuum container (if more than two materials are used, each is usually placed in a separate crucible), and the inside of the vacuum container is vacuumed with a vacuum pump for 10°C.-4 After evacuating to approximately Pa, the crucible is heated (if two or more materials are used, each crucible is usually heated) to evaporate the materials in the crucible while controlling the evaporation rate (if two or more materials are used, each is usually evaporated independently) to form a hole injection layer on the anode on the substrate placed facing the crucible. Furthermore, when using two or more materials, the mixture can be placed in a crucible, heated, and evaporated to form a hole-injection layer.

[0377] The vacuum level during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is typically 0.1 × 10⁻⁶. -6 Torr(0.13×10 -4 Pa) or more, 9.0×10 -6 Torr(12.0×10 -4 The pressure is less than or equal to Pa. 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 also be cross-linked in the same manner as the hole transport layer 4 described later.

[0378] [Hole transport layer] The hole transport layer 4 is a layer responsible for transporting holes from the anode 2 to the light-emitting layer 5. Although the hole transport layer 4 is not an essential layer in the organic electroluminescent device of the present invention, it is preferable to form this layer in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5. When the hole transport layer 4 is formed, it is usually formed between the anode 2 and the light-emitting layer 5. Also, if the hole injection layer 3 described above is present, it is formed between the hole injection layer 3 and the light-emitting layer 5.

[0379] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and on the other hand, it is usually 300 nm or less, preferably 100 nm or less.

[0380] The hole transport layer 4 may be formed by vacuum deposition or wet deposition. However, due to its superior film-forming properties, it is preferable to form the hole transport layer 4 by wet deposition.

[0381] A general method for forming a hole transport layer is described below, but in the organic electroluminescent device of the present invention, the hole transport layer is preferably formed by a wet film deposition method using the above-mentioned organic electroluminescent device composition.

[0382] The hole transport layer 4 typically contains a hole transport compound. The hole transport compound included in the hole transport layer 4 is preferably the polymer described above or a polymer obtained by crosslinking the polymer described above. Furthermore, in addition to the polymer described above, other preferred materials include the hole transport compound, aromatic diamines such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, which contains two or more tertiary amines and in which two or more condensed aromatic rings are substituted with nitrogen atoms (Japanese Patent Publication No. 5-234681), and aromatic amine compounds having a starburst structure such as 4,4',4''-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., 72-7). Preferred materials include aromatic amine compounds consisting of a tetramer of triphenylamine (Chem.Commun., 2175, 1996), spiro compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth.Metals, vol.91, p.209, 1997), and carbazole derivatives such as 4,4'-N,N'-dicarbazolebiphenyl. The hole transport layer 4 may also contain, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Publication No. 7-53953), polyarylene ethersulfone containing tetraphenylbenzidine (Polym.Adv.Tech., vol.7, p.33, 1996).

[0383] [Formation of hole transport layer by wet deposition method] When forming a hole transport layer using a wet deposition method, the hole transport layer is usually formed using a hole transport layer formation composition instead of a hole injection layer formation composition, in the same manner as when forming the hole injection layer using the wet deposition method described above.

[0384] When forming a hole transport layer by a wet film deposition method, the hole transport layer forming composition typically also contains a solvent. The solvent used in the hole transport layer forming composition can be the same solvent used in the hole injection layer forming composition described above. The concentration of the hole-transporting compound in the hole-transporting layer-forming composition can be within the same range as the concentration of the hole-transporting compound in the hole-injection layer-forming composition. The hole transport layer can be formed by a wet deposition method in the same manner as the hole injection layer deposition method described above.

[0385] [Formation of a hole transport layer by vacuum deposition] When forming a hole transport layer by vacuum deposition, it is usually possible to form it using a hole transport layer formation composition instead of a hole injection layer formation composition, in the same manner as when forming the hole injection layer by vacuum deposition described above. The deposition conditions, such as the degree of vacuum, deposition rate, and temperature, can be the same as those for vacuum deposition of the hole injection layer.

[0386] [Luminous layer] The light-emitting layer 5 is a layer that is excited and emits light when an electric field is applied between a pair of electrodes, by the recombination of holes injected from the anode 2 and electrons injected from the cathode 9. The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 9. If there is a hole injection layer above the anode, the light-emitting layer is formed between the hole injection layer and the cathode. If there is a hole transport layer above the anode, the light-emitting layer is formed between the hole transport layer and the cathode.

[0387] The film thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention. However, a thicker film is preferable in that defects are less likely to occur in the film, while a thinner film is preferable in that it is easier to achieve a low driving voltage. For this reason, the film thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and more preferably 200 nm or less, and even more preferably 100 nm or less.

[0388] The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material), and preferably a material having charge-transporting properties (charge-transporting material). Among these, the materials listed above as the light-emitting layer material are preferred. The following materials are also preferably used.

[0389] [Luminescent material] The luminescent 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; known luminescent materials can be used. The luminescent material may be a fluorescent material or a phosphorescent material, but a material with good luminescence efficiency is preferred, and a phosphorescent material is preferred from the viewpoint of internal quantum efficiency.

[0390] Examples of fluorescent materials include the following: Examples of fluorescent materials that emit blue light (blue fluorescent materials) include naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis(2-phenylethenyl)benzene, and their derivatives. Examples of fluorescent materials that emit green light (green fluorescent materials) include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al(C9H6NO)3.

[0391] Examples of fluorescent materials that emit yellow light (yellow fluorescent materials) include rubrene and perimidone derivatives. 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.

[0392] Examples of phosphorescent materials include organometallic complexes containing metals selected from groups 7 to 11 of the long-period periodic table. Preferred metals selected from groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

[0393] Preferred ligands for organometallic complexes include (hetero)arylpyridine ligands and (hetero)arylpyrazole ligands, which are ligands in which a (hetero)aryl group is linked to pyridine, pyrazole, phenanthroline, etc., with phenylpyridine ligands and phenylpyrazole ligands being particularly preferred. Here, (hetero)aryl refers to an aryl group or a heteroaryl group.

[0394] Preferred phosphorescent materials include, specifically, phenylpyridine complexes such as tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, tris(2-phenylpyridine)osmium, and tris(2-phenylpyridine)rhenium, as well as porphyrin complexes such as octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, and octaphenylpalladium porphyrin.

[0395] Examples of polymer-based luminescent 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)], and polyphenylene vinylene-based materials such as poly[2-methoxy-5-(2-hexylhexyloxy)-1,4-phenylene vinylene].

[0396] [Charge transport material] A charge-transporting material is a material that has the ability to transport positive charges (holes) or negative charges (electrons), and is not particularly limited as long as it does not impair the effects of the present invention; known light-emitting materials can be used. The charge transport material can be a compound that has been conventionally used in the light-emitting layer of an organic electroluminescent device, and in particular, a compound used as a host material for the light-emitting layer is preferred. Furthermore, the polymer of the present invention can also be used as a host material for the light-emitting layer.

[0397] Examples of charge-transporting materials include aromatic amine compounds containing the polymer of the present invention, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which tertiary amines are linked by fluorene groups, hydrazone compounds, silazane compounds, silanamine compounds, phosphatamine compounds, quinacridone compounds, and other compounds exemplified as hole-transporting compounds for the hole-injection layer. Other examples of electron-transporting compounds include anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, phenanthroline compounds, oxadiazole compounds, silole compounds, and so on.

[0398] Furthermore, 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 (Japanese Patent Publication No. 5-234681), and aromatic amine compounds having a starburst structure such as 4,4',4''-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., Vol. 72-74, p. 985, 1997), and triphenylamine Compounds exemplified as hole-transporting compounds for the hole transport layer, such as aromatic amine compounds consisting of a tetramer of fluorine (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'-dicarbazole biphenyl, can also be preferably used.

[0399] In addition, 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 vasophenanthroline (BPhen) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, vasocuproine).

[0400] [Formation of the light-emitting layer by wet film deposition method] The light-emitting layer may be formed by vacuum deposition or wet deposition, but wet deposition is preferred due to its superior film-forming properties, and spin coating and inkjet methods are even more preferred. In particular, when the hole injection layer or hole transport layer that forms the lower layer of the light-emitting layer is formed using the above-mentioned organic electroluminescent element composition, it is preferable to use wet deposition because lamination by wet deposition is easy.

[0401] When forming a light-emitting layer by a wet deposition method, the light-emitting layer is usually formed using a composition prepared by mixing the material to be formed as the light-emitting layer with a soluble solvent (solvent for the light-emitting layer), instead of the composition for forming the hole injection layer, in the same manner as when forming the hole injection layer by the wet deposition method described above.

[0402] Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents, as mentioned for the formation of the hole implantation layer, as well as alkane-based solvents, halogenated aromatic hydrocarbon-based solvents, aliphatic alcohol-based solvents, alicyclic alcohol-based solvents, aliphatic ketone-based solvents, and alicyclic ketone-based solvents. Specific examples of solvents are given below, but the invention is not limited to these, as long as they do not impair the effects of the present invention.

[0403] For example, aliphatic ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); aromatic ether solvents such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether; aromatic ester solvents such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; toluene, xylene, mesitylene, cyclohexylbenzene, tetralin, and 3-isopropyl bisulfite. Examples include aromatic hydrocarbon solvents such as phenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; alkane solvents such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; aliphatic alcohol solvents such as butanol and hexanol; alicyclic alcohol solvents such as cyclohexanol and cyclooctanol; aliphatic ketone solvents such as methyl ethyl ketone and dibutyl ketone; and alicyclic ketone solvents such as cyclohexanone, cyclooctanone, and fencone. Of these, alkane solvents and aromatic hydrocarbon solvents are particularly preferred.

[0404] [Hole Blocking Layer] A hole-blocking layer 6 may be provided between the light-emitting layer 5 and the electron injection layer 8, which will be described later. The hole-blocking layer 6 is a layer that is 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.

[0405] This hole blocking layer 6 has the role of preventing holes moving from the anode 2 from reaching the cathode 9, and the role of efficiently transporting electrons injected from the cathode 9 toward the light-emitting layer 5. The required properties for 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).

[0406] Examples of hole blocking layer materials 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 dinuclear metal complexes, styryl compounds such as distyrylbiphenyl derivatives (Japanese Patent Publication No. 11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Publication No. 7-41759), and phenanthroline derivatives such as basocproine (Japanese 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 hole blocking layers.

[0407] There are no restrictions on the method of forming the hole blocking layer 6. Therefore, it can be formed by wet deposition, vapor deposition, 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 is usually 100 nm or less, preferably 50 nm or less.

[0408] [Electron transport layer] The electron transport layer 7 is provided between the light-emitting layer 5 and the electron injection layer 8 with the aim of further improving the current efficiency of the device.

[0409] The electron transport layer 7 is formed from a compound that can efficiently transport electrons injected from the cathode 9 towards the light-emitting layer 5 between electrodes under an applied electric field. The electron transport compound used in the electron transport layer 7 must have high electron injection efficiency from the cathode 9 or the electron injection layer 8, high electron mobility, and be able to efficiently transport the injected electrons.

[0410] Examples of electron-transporting compounds used in the electron transport layer include, for example, metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Publication No. 59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolbenzene (U.S. Patent No. 5645948), quinoxaline compounds (Japanese Patent Publication No. 6-207169), phenanthroline derivatives (Japanese Patent Publication No. 5-331459), 2-t-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, and the like.

[0411] 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.

[0412] The electron transport layer 7 is formed by laminating it onto the hole blocking layer 6 using either a wet deposition method or a vacuum deposition method, as described above. Vacuum deposition is typically used.

[0413] [Electron injection layer] The electron injection layer 8 plays the role of efficiently injecting electrons injected from the cathode 9 into the electron transport layer 7 or the light-emitting layer 5.

[0414] To efficiently perform electron injection, the material forming the electron injection layer 8 is preferably a metal with a low work function. Examples include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. The film thickness is preferably 0.1 nm or more and 5 nm or less.

[0415] Furthermore, doping organic electron transport materials, such as nitrogen-containing heterocyclic compounds like bathophenanthroline and metal complexes like aluminum complexes of 8-hydroxyquinoline, with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (as described in Japanese Patent Publication No. 10-270171, Japanese Patent Publication No. 2002-100478, Japanese Patent Publication No. 2002-100482, etc.) is also preferable because it improves electron injection and electron transport properties and enables the achievement of excellent film quality.

[0416] The film thickness of the electron injection layer 8 is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

[0417] The electron injection layer 8 is formed by laminating it onto the light-emitting layer 5 or the hole-blocking layer 6 or electron transport layer 7 located thereon, using a wet deposition method or a vacuum deposition method. The details for the wet film deposition method are the same as those for the luminescent layer described above.

[0418] [cathode] The cathode 9 plays the role of injecting electrons into the layer on the light-emitting layer 5 side (such as the electron injection layer or light-emitting layer).

[0419] As the material for the cathode 9, the same material used for the anode 2 can be used. However, for efficient electron injection, it is preferable to use a metal with a low work function. For example, metals such as tin, magnesium, indium, calcium, aluminum, and silver, or alloys thereof, can be used. Specific examples of alloys include low-work-function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0420] In terms of device stability, it is preferable to protect the cathode, which is made of a metal with a low work function, by laminating a metal layer with a high work function and stability to the atmosphere on top of the cathode. Examples of metals to be laminated include aluminum, silver, copper, nickel, chromium, gold, and platinum. The film thickness of the cathode is usually similar to that of the anode.

[0421] [Other layers] The organic electroluminescent element of the present invention may have other layers as long as they do not significantly impair the effects of the present invention. That is, it may have any other layer between the anode and the cathode as described above.

[0422] [Other component configurations] The organic electroluminescent element of the present invention can also have a structure opposite to that described above, namely, a structure in which a cathode, electron injection layer, electron transport layer, hole blocking layer, light-emitting layer, hole transport layer, hole injection layer, and anode are stacked in that order on a substrate.

[0423] When applying the organic electroluminescent element of the present invention to an organic electroluminescent device, it may be used as a single organic electroluminescent element, in a configuration in which multiple organic electroluminescent elements are arranged in an array, or in a configuration in which the anode and cathode are arranged in an XY matrix.

[0424] <Organic EL display device> The organic EL display device (organic electroluminescent element display device) of the present invention uses the organic electroluminescent element described above. There are no particular restrictions on the type or structure of the organic EL display device of the present invention, and it can be assembled using the organic electroluminescent element described above in accordance with conventional methods.

[0425] 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 August 20, 2004, authored by Shizuka Tokito, Chihaya Adachi, and Hideyuki Murata).

[0426] <Organic EL lighting> The organic EL lighting (organic electroluminescent element lighting) of the present invention uses the organic electroluminescent element described above. There are no particular restrictions on the type or structure of the organic EL lighting of the present invention, and it can be assembled according to conventional methods using the organic electroluminescent element described above. [Examples]

[0427] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples, and can be modified and implemented as such without departing from its essence.

[0428] <Synthesis of intermediates> [Synthesis of Compound 1]

[0429] [ka]

[0430] Under a nitrogen atmosphere, 4-bromo-3-iodotoluene (10.6 g, 35.7 mmol), 2,5-dimethylphenylboronic acid (5.1 g, 33.9 mmol), potassium phosphate (18.0 g, 84.8 mmol), toluene (85 ml), ethanol (43 ml), and water (43 ml) were placed in a flask, and the system was thoroughly purged with nitrogen and heated to 60°C.

[0431] Bis(triphenylphosphine)palladium(II) dichloride (0.12 g, 0.17 mmol) was added and the mixture was stirred at 60°C for 2 hours. Water was added to the reaction mixture and extracted 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 (eluent: hexane) to obtain compound 1 (8.4 g, yield 89.8%).

[0432] [Synthesis of Compound 2]

[0433] [ka]

[0434] Under a nitrogen stream, 70 ml of N,N-dimethylacetamide, compound 1 (8.4 g, 30.5 mmol), pivalic acid (3.1 g, 30.5 mmol), and potassium carbonate (25.0 g, 184.1 mmol) were placed in a 300 ml flask and stirred with nitrogen bubbling at 50°C for 15 minutes. Then, a solution prepared with 20 ml of N,N-dimethylacetamide, palladium acetate Pd(OAc)2 (0.23 g, 0.92 mmol), and tricyclohexylphosphophine (0.51 g, 1.83 mmol) was added and reacted at 150°C for 3 hours.

[0435] 120 ml of pure water was added dropwise at room temperature, extracted with 120 ml of methylene chloride, and dried over anhydrous magnesium sulfate. Further purification by column chromatography (eluent: hexane) yielded compound 2 (5.0 g, yield 84.3%).

[0436] [Synthesis of Compound 3]

[0437] [ka]

[0438] Under a nitrogen atmosphere, compound 2 (5.0 g, 25.7 mmol), 30 ml of tetrahydrofuran, and potassium tert-butoxide (11.6 g, 102.9 mmol) were placed in a flask, and the system was thoroughly purged with nitrogen at room temperature. Iodomethane (11.0 g, 77.2 mmol) was gradually added dropwise, and the mixture was stirred at 40°C for 4 hours. 150 ml of deionized water was added to the reaction mixture at room temperature, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and concentrated. Further purification by column chromatography (eluent: hexane) yielded compound 3 (4.2 g, yield 73.1%).

[0439] [Synthesis of Compound 4]

[0440] [ka]

[0441] Compound 3 (4.2 g, 18.8 mmol), iodine (0.05 g, 0.19 mmol), and 25 ml of methylene chloride were placed in a flask. A solution of 5 ml of methylene chloride with bromine (6.3 g, 39.5 mmol) was slowly added dropwise at 0°C. After 1 hour, the reaction mixture was poured into ice water and stirred. Sodium thiosulfate aqueous solution (0.5 g, 20 ml of water) was added, and extraction was performed with methylene chloride. The organic layer was dried over anhydrous magnesium sulfate. The mixture was purified by column chromatography (eluent: hexane / methylene chloride = 100 / 1) to obtain compound 4 (4.3 g, yield 60.2%).

[0442] [Synthesis of Compound 5]

[0443] [ka]

[0444] Under a nitrogen atmosphere, 50 ml of dimethyl sulfoxide, compound 4 (4.3 g, 11.3 mmol), bis(pinacolato)diborone (8.6 g, 33.9 mmol), and potassium acetate (6.7 g, 67.9 mmol) were added to a 200 ml flask and stirred at 60°C for 30 minutes. Then, 1,1'-bis(diphenylphosphino)ferrocene-palladium(II) dichloride-dichloromethane [PdCl2(dppf)CH2Cl2] (0.92 g, 1.1 mmol) was added and the mixture was reacted at 95°C for 4 hours.

[0445] The reaction mixture was filtered under reduced pressure after adding pure water dropwise at room temperature, and the filtrate was extracted with toluene. The mixture was then dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was further purified by column chromatography (eluent: hexane / ethyl acetate = 950 / 50) to obtain compound 5 (3.1 g, yield 57.8%).

[0446] [Synthesis of Compound 6]

[0447] [ka]

[0448] Next, compound 5 (3.1 g, 6.5 mmol), 1-bromo-4-iodobenzene (5.5 g, 19.6 mmol), potassium phosphate (2 M aqueous solution, 20 ml), toluene (40 ml), and ethanol (20 ml) were placed in a flask, the system was thoroughly purged with nitrogen, and the mixture was heated to 60°C. Bis(triphenylphosphine)palladium(II) dichloride (0.092 g, 0.13 mmol) was added, and the mixture was stirred at 60°C for 8 hours. Water was added to the reaction mixture, and extraction was performed with toluene. The organic layer was dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was purified by column chromatography (eluent:hexane:toluene = 600:400) to obtain compound 6 (2.6 g, yield 74.7%).

[0449] [Synthesis of Compound 7]

[0450] [ka]

[0451] Compound 7 was synthesized using the method described in International Publication No. 2019 / 177175.

[0452] [Synthesis of Compound 9]

[0453] [ka]

[0454] Under a nitrogen atmosphere, 50 ml of dimethyl sulfoxide, commercially available compound 8 (10.0 g, 23.04 mmol), bis(pinacolato)diborone (17.5 g, 68.91 mmol), and potassium acetate (13.5 g, 137.56 mmol) were added to a 200 ml flask and stirred at 60°C for 30 minutes. Then, 1,1'-bis(diphenylphosphin)ferrocene-palladium(II) dichloride-dichloromethane [PdCl2(dppf)CH2Cl2] (1.9 g, 23.27 mmol) was added and the mixture was reacted at 95°C for 4.5 hours.

[0455] The reaction mixture was filtered under reduced pressure after adding pure water dropwise at room temperature, and the filtrate was extracted with toluene. The mixture was then dried over anhydrous magnesium sulfate and crudely purified using activated clay. The crude product was further purified by column chromatography (eluent: hexane / ethyl acetate = 700 / 300) to obtain compound 9 (8.2 g, yield 82%).

[0456] [Synthesis of Compound 10]

[0457] [ka]

[0458] Next, compound 9 (3.0 g, 6.91 mmol), 1-bromo-4-iodobenzene (7.8 g, 27.6 mmol), potassium phosphate (2 M aqueous solution, 21 ml), toluene (50 ml), and ethanol (25 ml) were placed in a flask, the system was thoroughly purged with nitrogen, and the mixture was heated to 60°C. Bis(triphenylphosphine)palladium(II) dichloride (0.049 g, 0.07 mmol) was added, and the mixture was stirred at 60°C for 1.5 hours. Water was added to the reaction mixture, and 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 (eluent:hexane:toluene = 750:250) to obtain compound 10 (0.6 g, yield 17.6%).

[0459] [Synthesis of Compound 11]

[0460] [ka]

[0461] Compound 11 was obtained using the same reaction conditions and purification method as for compound 10. <Example 1> [Synthesis of Polymer 1] Polymer 1 was synthesized according to the following reaction equation.

[0462] [ka]

[0463] Compound 6 (2.50 g, 4.70 mmol), 2-amino-9,9-dihexylfluorene (1.15 g, 3.29 mmol), Compound 7 (0.93 g, 0.95 mmol), 2-amino-9,9-dimethylfluorene (1.08 g, 5.16 mmol), tert-butoxysodium (3.48 g, 36.21 mmol), and toluene (45 g, 52 ml) were charged, the system was thoroughly purged with nitrogen, and heated to 60°C (Solution A1).

[0464] To a 15 ml solution of tris(dibenzylideneacetone)dipalladium complex (86.0 mg, 0.094 mmol) in toluene, [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.20 g, 0.75 mmol) was added and heated to 60°C (Solution B1).

[0465] Under a nitrogen atmosphere, solution B1 was added to solution A1 and the reaction was carried out under reflux for 1.0 hour. After confirming that compound 7 had disappeared, compound 10 (2.50 g, 5.08 mmol) was added. After heating under reflux for 2 hours, bromobenzene (0.89 g, 5.67 mmol) was added and the reaction was carried out under reflux for 2 hours. The reaction mixture was allowed to cool, 101 ml of toluene was added, and the mixture was added dropwise to an ethanol / water (550 ml / 100 ml) solution to obtain a crude polymer with end caps.

[0466] The end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was filtered off. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The filtered polymer was purified by column chromatography to obtain the target polymer 1 (2.2 g). The molecular weight and other properties of the obtained polymer 1 were as follows.

[0467] Weight average molecular weight (Mw)=37550 Number average molecular weight (Mn)=30040 Dispersity (Mw / Mn)=1.25

[0468] In Example 1 and the other examples, calibration curves were created using polystyrene of each molecular weight, and the molecular weight of the polymer was measured under the following conditions. Equipment: SHIMADZU GPC system System Control: CBM-20Alite Column Oven:CTO-20APump :LC-20ATDetector :SPD-20AVSolvent :THFColumns (manufacturer, model no.:TSKgel Supermultipore HZ-M (4.6mm ID x 150mm) x4μmTemperature:40℃Flow rate:0.35mL / minInjection volume and concentration of sample:10μL, 1% conc.

[0469] <Example 2> [Synthesis of Polymer 2] Polymer 2 was synthesized according to the following reaction equation.

[0470] [ka]

[0471] Compound 10 (1.2g, 2.44 mmol), 2-amino-9,9-dihexylfluorene (0.21g, 0.60 mmol), Compound 7 (2.40g, 2.44 mmol), 2-amino-9,9-dimethylfluorene (0.39g, 1.86 mmol), tert-butoxysodium (1.81g, 18.83 mmol), and toluene (64g, 73 ml) were charged, the system was thoroughly purged with nitrogen, and heated to 60°C (Solution A2).

[0472] To an 8 ml solution of tris(dibenzylideneacetone)dipalladium complex (0.045 g, 0.049 mmol) in toluene, [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.11 g, 0.41 mmol) was added and heated to 60°C (Solution B2).

[0473] Under a nitrogen atmosphere, solution B2 was added to solution A2 and the reaction was carried out under reflux by heating for 1.0 hour. After confirming that compound 7 had disappeared, compound 6 (0.26 g, 0.49 mmol) was added. After 1 hour, compound 10 (0.804 g, 1.63 mmol) was added. After heating under reflux for 1 hour, bromobenzene (0.5 g, 3.18 mmol) was added and the reaction was carried out under reflux by heating for 2 hours. The reaction mixture was allowed to cool, and the crude polymer was obtained by dropping it into an ethanol / water (270 ml / 50 ml) solution and end-capping.

[0474] The end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was filtered off. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The filtered polymer was purified by column chromatography to obtain the target polymer 2 (2.3 g). The molecular weight and other properties of the obtained polymer 2 were as follows.

[0475] Weight average molecular weight (Mw)=39600 Number average molecular weight (Mn)=29118 Dispersity (Mw / Mn)=1.36

[0476] <Comparative Examples 1 and 2> Polymers 7 and 11 described in International Publication No. 2019 / 177175 were used as Comparative Examples 1 and 2.

[0477] [ka]

[0478] [ka]

[0479] [Measurement of excited singlet energy levels (S1) and excited triplet energy levels (T1) of polymers] Each polymer was dissolved in 2-methyltetrahydrofuran to prepare a 0.01% by mass solution. The fluorescence emission spectrum and phosphorescence emission spectrum of this solution sample were measured using a fluorescence spectrophotometer (Hitachi, Ltd., F-4500) at an excitation wavelength of 350 nm and under cooling conditions with liquid nitrogen. The S1 and T1 levels were obtained from the peak top wavelength of the shortest emission peak in the obtained fluorescence emission spectrum and phosphorescence emission spectrum. The measurement results are shown in Table 1.

[0480] [Table 1]

[0481] Examples 1 and 2 (polymers 1 and 2) have higher S1 and T1 energy levels than Comparative Examples 1 and 2 (polymers 7 and 11), demonstrating that quenching due to energy transfer from each light-emitting exciton to the polymer is less likely to occur in organic electroluminescent devices.

[0482] <Example 3> [Synthesis of Polymer 3]

[0483] [ka]

[0484] Compound 6 (1.5g, 2.82 mmol), 2-amino-9,9-dihexylfluorene (0.611g, 1.75 mmol), Compound 7 (1.11g, 1.13 mmol), 2-amino-9,9-dimethylfluorene (0.58g, 2.76 mmol), tert-butoxysodium (2.09g, 21.75 mmol), and toluene (72g, 83 ml) were charged, the system was thoroughly purged with nitrogen, and heated to 60°C (Solution A3).

[0485] To a 9 ml solution of tris(dibenzylideneacetone)dipalladium complex (0.052 g, 0.056 mmol) in toluene, [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.12 g, 0.45 mmol) was added and heated to 60°C (Solution B3).

[0486] Under a nitrogen atmosphere, solution B3 was added to solution A3 and the reaction was carried out under reflux for 1.0 hour. After confirming that compound 6 had disappeared, compound 6 (1.34 g, 2.51 mmol) was added. After heating under reflux for 2 hours, bromobenzene (0.49 g, 3.12 mmol) was added and the reaction was carried out under reflux for 1 hour. The reaction mixture was allowed to cool, and the crude polymer was obtained by dropping it into an ethanol / water (270 ml / 50 ml) solution and end-capping.

[0487] The end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was filtered off. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The filtered polymer was purified by column chromatography to obtain the target polymer 3 (2.0 g). The molecular weight and other properties of the obtained polymer 3 were as follows.

[0488] Weight average molecular weight (Mw)=42000 Number average molecular weight (Mn)=31579 Dispersity (Mw / Mn)=1.33

[0489] Organic electroluminescent devices were fabricated using the following method. A transparent conductive film of indium tin oxide (ITO) was deposited to a thickness of 50 nm on a glass substrate (Geomatec Co., Ltd., sputter-deposited product). This film was then patterned into 2 mm wide stripes using conventional photolithography techniques and hydrochloric acid etching to form an anode. The substrate with the ITO pattern was then cleaned in the following order: ultrasonic cleaning with a surfactant aqueous solution, rinsing with ultrapure water, ultrasonic cleaning with ultrapure water, and rinsing with ultrapure water. After drying with compressed air, the substrate was finally cleaned with ultraviolet ozone.

[0490] As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0% by mass of a hole-transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6% by mass of an electron-accepting compound (HI-1) in ethyl benzoate.

[0491] [ka]

[0492] This solution was spin-coated onto the substrate in air, dried on a hot plate at 240°C for 30 minutes in air to form a uniform thin film with a thickness of 40 nm, which served as the hole injection layer.

[0493] Next, the polymer of the present invention (polymer 3) having the following structural formula was dissolved in 1,3,5-trimethylbenzene to prepare a 2.0% by mass solution.

[0494] This solution was spin-coated onto a substrate coated with the hole injection layer in a nitrogen glove box, 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 served as the hole transport layer.

[0495] [ka]

[0496] Subsequently, as a material for the light-emitting layer, a composition for forming the light-emitting layer was prepared by dissolving a compound (H-1) having the following structure in cyclohexylbenzene at a concentration of 1.2% by mass, a compound (H-2) having the following structure in 1.2% by mass, a compound (H-3) having the following structure in 0.8% by mass, and a compound (D-1) having the following structure in 1.0% by mass.

[0497] [ka]

[0498] This solution was spin-coated onto a substrate coated with the hole transport layer in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 40 nm, which served as the light-emitting layer.

[0499] A substrate with the light-emitting layer deposited is placed in a vacuum deposition apparatus, and the inside of the apparatus is 2 × 10 -4 The exhaust was vented until the pressure dropped below Pa.

[0500] Next, the following structural formula (ET-1) and 8-hydroxyquinolinolatritium were co-deposited onto the light-emitting layer in a film thickness ratio of 2:3 using vacuum deposition to form an electron transport layer with a film thickness of 30 nm.

[0501] [ka]

[0502] Next, a 2 mm wide striped shadow mask was placed in close contact with the substrate as a mask for cathode deposition, perpendicular to the ITO stripe of the anode. The aluminum was then heated using a molybdenum boat to form an aluminum layer with a thickness of 80 nm, thereby forming the cathode. In this way, an organic electroluminescent device having an emitting area of ​​2 mm × 2 mm was obtained.

[0503] <Comparative Example 3> An organic electroluminescent device was fabricated in the same manner as in Example 3, except that the hole transport layer was formed from a composition obtained by dissolving a polymer compound having the following structural formula (HT-2) in 1,3,5-trimethylbenzene.

[0504] [ka]

[0505] [Synthesis of HT-2]

[0506] [ka]

[0507] Compound 11 (2.5g, 4.96 mmol), 2-amino-9,9-dihexylfluorene (0.683g, 1.95 mmol), Compound 7 (1.95g, 1.98 mmol), 2-amino-9,9-dimethylfluorene (1.25g, 5.98 mmol), tert-butoxysodium (3.76g, 38.19 mmol), and toluene (45g, 52 ml) were charged, the system was thoroughly purged with nitrogen, and heated to 60°C (Solution A4).

[0508] To a 16 ml solution of tris(dibenzylideneacetone)dipalladium complex (0.091 g, 0.099 mmol) in toluene, [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (Amphos) (0.211 g, 0.79 mmol) was added and heated to 60°C (Solution B4).

[0509] Under a nitrogen atmosphere, solution B4 was added to solution A4 and the reaction was carried out under reflux for 1.0 hour. After confirming that compound 11 had disappeared, compound 11 (2.15 g, 4.26 mmol) was added. After heating under reflux for 2 hours, bromobenzene (0.55 g, 3.50 mmol) was added and the reaction was carried out under reflux for 1 hour. The reaction solution was allowed to cool, diluted with 88 g of toluene, and then added dropwise to an ethanol / water (300 ml / 50 ml) solution to obtain a crude polymer with end caps.

[0510] The end-capped crude polymer was dissolved in toluene, reprecipitated in acetone, and the precipitated polymer was filtered off. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and reprecipitated with ammonia-containing ethanol. The filtered polymer was purified by column chromatography to obtain the target product, HT-2 (3.2 g). The molecular weight and other properties of the obtained HT-2 were as follows.

[0511] Weight average molecular weight (Mw)=39600 Number average molecular weight (Mn)=28905 Dispersity (Mw / Mn)=1.37

[0512] [Evaluation of Organic Electroluminescent Devices] The organic electroluminescent elements obtained in Example 3 and Comparative Example 3 were subjected to a 1,000 cd / m² test. 2 The voltage, current luminescence efficiency (cd / A), and external quantum efficiency (EQE(%)) were measured when the light was emitted. The relative voltage was defined as the value obtained by subtracting the voltage of Comparative Example 3 from the voltage of Example 3. The relative current luminescence efficiency of Example 3 was defined as the relative current luminescence efficiency when the current luminescence efficiency of Comparative Example 3 was set to 100. The external quantum efficiency (EQE(%)) of Example 3 was determined when the external quantum efficiency (EQE(%)) of Comparative Example 3 was set to 100, and this was defined as the relative EQE. These measurement results are shown in Table 2.

[0513] [Table 2]

[0514] The results in Table 2 show that high-performance devices can be obtained with the organic electroluminescent device of the present invention.

[0515] [Confirmation of S1 and T1 levels by calculation] The S1 and T1 levels of the following model structural units 1 to 9 were confirmed through calculations.

[0516] Calculation Method: The software Gaussian 09, Revision B.01 was used for the calculation of T1 and S1 levels. Density Functional Theory was adopted as the quantum chemical calculation method, with B3LYP as the functional and 6-31G as the basis set for the ground state structure optimization calculation. * We performed a structural optimization calculation of the ground state using [this method].

[0517] Gaussian 09, Revision B.01, M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G.A. Petersson, H. Nakatsuji, M. Caricato, X. Li, H.P. Hratchian, A.F. Izmaylov, J. Bloino, G. Zheng, J.L. Sonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, J.A. Montgomery, Jr., J.E. Peralta, F. Ogliaro, M. Bearpark, J.J. Heyd, E. Brothers, K.N. Kudin, V.N. Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J.C. Burant, S.S. Iyengar, J. Tomasi, M. Cossi, N. Rega, J.M. Millam, M. Klene, J.E. Knox, J.B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R.E. Stratmann, O. Yazyev, A.J. Austin, R. Cammi, C. Pomelli, J.W. Ochterski, R.L. Martin, K. Morokuma, V.G. Zakrzewski, G.A. Voth, P. Salvador, J.J. Dannenberg, S. Dapprich, A.D. Daniels, O. Farkas, J.B. Foresman, J.V. Ortiz, J.C. Cioslowski, and D.J. Fox, Gaussian, Inc., Wallingford CT, 2010.

[0518]

Chem.

[0519] The T1 and S1 level results from this calculation are shown in Table 3.

[0520] [Table 3]

[0521] In units 1 and 2, by introducing methyl groups as substituents at the 3rd and 6th positions, or the 1st and 8th positions, the adjacently bonded fluorene and phenylene form a more twisted structure due to steric hindrance from the substituents, compared to unit 4, which has no substituents at any of the 1st, 3rd, 6th, and 8th positions of the fluorene.

[0522] On the other hand, unit 3, which has no substituents at positions 1, 3, 6, and 8 of fluorene and has a twisted structure in which the phenylene adjacent to the fluorene has a methyl group on the carbon atom adjacent to the carbon atom bonded to the fluorene, also forms a twisted structure similar to unit 1 and unit 2.

[0523] However, surprisingly, even though they both have the same torsion, units 1 and 2, which are the structures of the present invention, were found to have a higher S1 level than unit 3, indicating superior performance.

[0524] Furthermore, Unit 2 was found to have an even higher T1 level than Units 1 and 3, indicating a better performance.

[0525] Furthermore, it is preferable that the main chain of the polymer of the present invention has a monoring adjacent to the nitrogen atom of the amine, i.e., phenylene. In this case, it is even more preferable that the phenylene is unsubstituted. In the main chain of the polymer of the present invention, the S1 and T1 levels are higher when the adjacent to the nitrogen atom of the amine is a monoring rather than a fused ring. Therefore, it is believed that an organic electroluminescent device in which a light-emitting layer is formed in contact with a hole transport layer containing the polymer of the present invention has high luminescence efficiency.

[0526] To verify this, we use the structure represented by equation (A) as the model structure, R 1 and R 2 , or R 51 and R 52 However, if it is a methyl group or hydrogen, and Ar 20 We assumed that the group is either a divalent group of fluorene, which is a fused ring; a divalent group of biphenyl, which has two phenylene units bonded to it; or a phenylene group.

[0527] For specific structures, the T1 and S1 levels were calculated for the structures of units 5 to 9. Note that the unit structure (1) in equation (A) is a structure included in the repeating structure represented by equation (1). The T1 and S1 level results from this calculation are shown in Table 4.

[0528] [ka]

[0529] [ka]

[0530] [Table 4]

[0531] Ar 20 From comparisons between Unit 6 and Unit 5, and between Unit 8 or Unit 9 and Unit 7, it was found that the divalent biphenyl group and phenylene group, which have monocyclic structures bonded to the nitrogen atom, have higher T1 and S1 levels and are therefore better than the divalent fluorene group, which has a fused ring structure bonded to the nitrogen atom of the main chain.

[0532] Also, Ar 20 When comparing unit 6 and unit 8, which are the divalent groups of biphenyl, the R of fluorene, which is a substructure of the unit structure (1), 1 and R 2The methyl group is the R of phenylene in the main chain. 51 and R 52 The structure of unit 6, where hydrogen is present, is similar to the structure of fluorene, which is a substructure of unit structure (1). 1 and R 2 It is hydrogen and the R of phenylene in the main chain 51 and R 52 The structure of unit 8, which is a methyl group, is S 1 The level was found to be high and in good condition.

[0533] Ar 20 Similarly, in a comparison between unit 5 and unit 7, which are the divalent groups of fluorene, it was found that unit 5 had a higher S1 level and was superior. 20 The structure of unit 9, where is a phenylene group, is Ar 20 It was found that this has a higher T1 level and is better than unit 6, which is the divalent group of biphenylene.

[0534] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2020-157856 filed on 18 September 2020, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0535] 1. Circuit board 2.Anode 3. Hole injection layer 4. Hole transport layer 5. Emitting layer 6. Hole Blocking Layer 7.Electron transport layer 8.Electron injection layer 9.Cathode 10. Organic electroluminescent element

Claims

1. A polymer comprising a repeating unit represented by the following formula (1), and further comprising at least one of the repeating units represented by the following formula (3)-1 and the following formula (3)-2. 【Chemistry 1】 (In formula (1), Ar １ This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar ２ and Ar ３ Each of these independently represents a divalent aromatic hydrocarbon group which may have substituents, or a divalent group in which multiple aromatic hydrocarbon groups which may have substituents are linked directly or via linking groups in the direction of the main chain. X represents -C(R ７ )(R ８ )-, -N(R ９ )-, or -C(R １０ )(R １１ )-C(R １２ )(R １３ )-, and R １ ~R ８ Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R １ , R ２ , R ５ , R ６ At least one of them is an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R ９ ~R １３ Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group. n represents an integer between 1 and 3. However, the two structures that constitute the main chain of the polymer and are directly bonded to the nitrogen atom of the main chain amine in formula (1) are both phenylene groups, which may have substituents. 【Chemistry 2】 (In equation (3)-1 or equation (3)-2, Ar 4 independently represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. X 30 represents -C(R 37)(R 38)-, -N(R 39)-, or -C(R 40)(R 41)-C(R 42)(R 43)-, R 33, R 34, R 37, R 38, R 120 to R 123 each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R39 to R43 each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group. g3, h3, and i3 each independently represent integers between 1 and 3. j³ and k³ each independently represent integers between 1 and 2.

2. In the above formula (1), Ar ３ Ar in the repeating unit adjacent to and joined ３ If the atom that bonds with it is not the nitrogen atom of the main chain amine, Ar ２ In the structure represented by , the structure bonded to the nitrogen atom of the main chain amine is a phenylene group without substituents. Ar ３ Ar in the repeating unit adjacent to and joined ３ If the atom that bonds with it is the nitrogen atom of the main chain amine, then Ar ２ In the structure represented by , the structure bonded to the nitrogen atom of the main chain amine is a phenylene group without substituents, and Ar ３ In the structure represented by Ar ３ The polymer according to claim 1, wherein at least one of the following conditions is met: the structure that directly bonds to the nitrogen atom of the main chain amine in the repeating unit adjacent to is a phenylene group without substituents.

3. The polymer according to claim 1 or 2, wherein the two structures in the main chain of the polymer that are bonded to the nitrogen atom of the main chain amine in formula (1) are unsubstituted phenylene groups.

4. The polymer according to any one of claims 1 to 3, wherein formula (1) is represented by the following formula (2)-1 or the following formula (2)-2. 【Transformation 3】 (In equation (2)-1 or equation (2)-2, Ar １ , R １ ~R ６ X is the same as the definition in formula (1) above, R ２０ ~R ２３ Each of them independently, R １ It is similar to this, g, h, and i each independently represent integers from 1 to 3. j and k each independently represent integers between 1 and 2.

5. Ar １ The polymer according to any one of claims 1 to 4, wherein is represented by the following formula (A1). 【Chemistry 4】 (In formula (A1), Ar ６ and Ar ７ Each of these independently represents a divalent aromatic hydrocarbon group which may have substituents, a divalent aromatic heterocyclic group which may have substituents, or a divalent group in which multiple groups selected from a divalent aromatic hydrocarbon group which may have substituents and a divalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar ８ This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar ９ represents a hydrogen atom or substituent, -* indicates the bonding position with the nitrogen atom in formula (1) above.

6. Ar ４ The polymer according to any one of claims 1 to 5, wherein is represented by the following formula (A2). 【Transformation 5】 (In formula (A2), Ar ３６ and Ar ３７ Each independently represents a divalent aromatic hydrocarbon group which may have substituents, a heterocyclic aromatic group which may have substituents, or a divalent group in which multiple groups selected from a heterocyclic aromatic hydrocarbon group which may have substituents and a heterocyclic aromatic group which may have substituents are linked directly or via linking groups. Ar ３８ This represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar ３９ represents a hydrogen atom or substituent, -* indicates the bonding position with the nitrogen atom in formula (3)-1 or formula (3)-2.

7. R １ and R ２ The polymer according to any one of claims 1 to 6, wherein each independently represents an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group.

8. A polymer comprising a repeating unit represented by the following formula (1), and having a crosslinkable group as a substituent. 【Transformation 6】 (In formula (1), Ar 1 represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar2 and Ar3 each independently represent a divalent aromatic hydrocarbon group which may have substituents, or a divalent group in which multiple aromatic hydrocarbon groups which may have substituents are linked directly or via linking groups in the direction of the main chain. X represents -C(R7)(R8)-, -N(R9)-, or -C(R10)(R11)-C(R12)(R13)-, R1 to R8 each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. At least one of R1, R2, R5, and R6 is an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R9 to R13 each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group. n represents an integer between 1 and 3. However, the two structures that constitute the main chain of the polymer and are directly bonded to the nitrogen atom of the main chain amine in formula (1) are both phenylene groups, which may have substituents.

9. A polymer according to any one of claims 1 to 8, wherein the weight-average molecular weight (Mw) is 10,000 or more, and the degree of dispersion (Mw / Mn) is 3.5 or less.

10. A composition for an organic electroluminescent element, comprising the polymer according to any one of claims 1 to 9.

11. A method for manufacturing an organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, The aforementioned organic layer is formed by a wet film deposition method using an organic electroluminescent element composition. The organic layer has at least one of a hole injection layer and a hole transport layer, The method for producing an organic electroluminescent element, wherein the composition for the organic electroluminescent element contains a polymer comprising a repeating unit represented by the following formula (1). 【Transformation 7】 (In formula (1), Ar 1 represents a monovalent aromatic hydrocarbon group which may have substituents, a monovalent aromatic heterocyclic group which may have substituents, or a monovalent group in which multiple groups selected from a monovalent aromatic hydrocarbon group which may have substituents and a monovalent aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Ar2 and Ar3 each independently represent a divalent aromatic hydrocarbon group which may have substituents, or a divalent group in which multiple aromatic hydrocarbon groups which may have substituents are linked directly or via linking groups in the direction of the main chain. X represents -C(R7)(R8)-, -N(R9)-, or -C(R10)(R11)-C(R12)(R13)-, R1 to R8 each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. At least one of R1, R2, R5, and R6 is an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R9 to R13 each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group. n represents an integer between 1 and 3. However, the two structures that constitute the main chain of the polymer and are directly bonded to the nitrogen atom of the main chain amine in formula (1) are both phenylene groups, which may have substituents.

12. The anode and the cathode are interposed, comprising the hole injection layer, the hole transport layer, and the light-emitting layer. The method for manufacturing an organic electroluminescent element according to claim 11, wherein the organic layer comprises the hole injection layer, the hole transport layer, and the light-emitting layer.

13. An organic electroluminescent element comprising a layer containing the polymer according to any one of claims 1 to 9, or a polymer obtained by crosslinking the polymer.

14. An organic EL display device comprising the organic electroluminescent element described in Claim 13.

15. Organic EL lighting comprising the organic electroluminescent element described in Claim 13.

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