Method for manufacturing organic semiconductor devices

Abstract

The present invention relates to a method for manufacturing an organic semiconductor element, the method comprising a step for applying and heating a first composition to provide a first functional film, and a step for applying a second composition on the first functional film to provide a second functional film, the first composition including a first functional material, wherein the first functional material includes an arylamine polymer having none of a bridging group, a polymerization group, or a cleavable solubilizing group, and having a weight-average molecular weight of 15000 to 50000 inclusive, and the second composition includes a solvent and has a viscosity of less than or equal to 15 mPa･s at 23℃, the solvent including at least one first solvent component having a viscosity of greater than or equal to 3 mPa･s at 23℃.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an organic semiconductor device that can suitably form a functional film, which is an organic film made of a functional material. [Background technology]

[0002] Examples of organic semiconductor devices include organic electroluminescent devices and organic transistors. Among these, the most common method for manufacturing organic electroluminescent devices is to deposit organic materials as thin films using vacuum deposition and then stack them. However, in recent years, there has been growing research into wet deposition methods, which involve depositing and stacking organic materials in solution using methods such as inkjet printing, as a manufacturing method with superior material utilization efficiency.

[0003] To form an organic electroluminescent element by laminating multiple layers using wet deposition, the coated thin film must be insoluble in the composition applied to the upper layer. Generally, the most stable method used involves incorporating crosslinking groups or polymerization groups into the composition and then creating bonds through post-coating processing to make it insoluble.

[0004] However, it has been found that laminating a light-emitting layer on a hole transport layer made using functional materials containing crosslinking or polymerization groups negatively affects the lifespan of blue elements in particular, as well as the light-emitting efficiency of blue and green elements.

[0005] For example, Patent Document 1 discloses a method for insolubilizing a semiconductor material that does not contain crosslinking groups or polymerization groups, which involves partially insolubilizing it by one or more of the following treatments: heat, vacuum, and open air drying, and then washing away the remaining dissolved portion to use only the insolubilized portion. Patent document 2 discloses a method for partially making a polymer, which is stacked as a semiconductor material, insoluble by heating it at a temperature higher than its glass transition temperature. Patent Document 3 discloses that a charge transport layer can be made insoluble even without the presence of crosslinking groups by heating the charge transport layer, irradiating it with electromagnetic waves, and especially irradiating it with UV light. Patent Document 4 discloses a method in which a thermally dissociable soluble group dissociates and becomes insoluble due to a chemical change caused by heat. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japan Special Publication No. 2005-537628 [Patent Document 2] Japanese Patent Publication No. 2013-065564 [Patent Document 3] Japanese Patent Application Publication No. 2014-212126 [Patent Document 4] Japanese Patent Publication No. 2010-059417 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the insolubilization method using semiconductor materials that do not contain crosslinking or polymerization groups, as disclosed in Patent Document 1, does not achieve complete insolubilization. Similarly, the method disclosed in Patent Document 2 assumes the use of the cleaning residue and does not achieve complete insolubilization of the laminated material itself. Patent document 3 also envisions the use of the remaining material after cleaning, stating that partial dissolution is preferable due to interfacial mixing with the upper layer. However, this impairs the use of optical interference, and in shorter wavelength blue and phosphorescent green elements, it may lead to a deterioration in efficiency and lifespan. Furthermore, the thickness of the remaining material is said to depend on the molecular weight, and to obtain a 20 nm charge transport layer, it is necessary to use a charge transport material with a molecular weight of 300,000. In order to use secondary interference, which avoids leakage due to foreign matter and obtains optical interference conditions with high color purity, a charge transport layer thickness of 50 to 150 nm is preferable, and it is difficult to form a charge transport layer of that thickness using this method. Methods of insolubilization using chemical changes of thermally dissociable groups, such as those disclosed in Patent Document 4, may hinder device efficiency in terms of the incorporation of dissociated materials into the upper layer.

[0008] Furthermore, it is generally known that using a "orthogonal solvent" with low solubility in the materials constituting the lower layer as the solvent in the upper layer composition is effective. However, in solution-type organic electroluminescent devices, the structures of the two stacked functional materials are similar, which limits the use of orthogonal solvents.

[0009] Furthermore, if the functional material constituting the lower layer is a low-solubility material with a molecular weight of several hundred thousand, insolubilization becomes easier. However, using a functional material with a large molecular weight increases the viscosity of the coating composition, negatively affecting its coatability and ultimately limiting the ability to create thick films or high-resolution designs that require high-concentration inks.

[0010] Furthermore, as the industrialization of organic semiconductor device manufacturing by wet film deposition approaches, there is an increasing demand for more practical insolubilization. This requires insolubilization of the underlying layer to be performed in a short time and at low temperatures, and to withstand the long solvent immersion required for coating larger area panels.

[0011] The present invention has been made in view of the above. Specifically, the objective is to provide a method for manufacturing a semiconductor light-emitting element that exhibits excellent insolubility of the functional film when an upper layer is provided, and that can be widely used, when forming a functional film containing organic material constituting an organic semiconductor element by wet deposition. More specifically, the objective is to achieve a good insolubilization effect without giving the above-mentioned organic material crosslinking groups, polymerization groups, or detachable solubilizing groups. Furthermore, by allowing a wide selection of the above-mentioned organic material and upper layer, the objective is to provide a method for manufacturing organic electroluminescent devices that enable the lamination of functional materials with excellent luminescence efficiency, luminescence lifetime, and coatability. [Means for solving the problem]

[0012] As a result of diligent research by the present inventors, we have found that even if the organic material constituting the functional film does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups, the above problem can be solved if the composition forming the upper layer satisfies certain requirements. In other words, the gist of this invention is as follows:

[0013] [1] A step of applying and heating the first composition to provide a first functional film, The process includes the step of applying a second composition onto the first functional film to provide a second functional film, The first composition comprises a first functional material, The first functional material described above does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups, and has a weight-average molecular weight of 15,000 to 50,000. below It contains an arylamine polymer, The second composition contains a solvent and has a viscosity of 15 mPa·s or less at 23°C. A method for manufacturing an organic semiconductor device, wherein the solvent comprises at least one first solvent component having a viscosity of 3 mPa·s or more at 23°C. [2] The solvent further comprises a second solvent component having a viscosity of less than 3 mPa·s at 23°C. A method for manufacturing an organic semiconductor device, wherein the fluid activation energy of the first solvent component is 17 kJ / mol or more [1]. [3] A step of applying and heating the first composition to provide a first functional film, The process includes the step of applying a second composition onto the first functional film to provide a second functional film, The first composition comprises a first functional material, The first functional material comprises an arylamine polymer that does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups. The second composition contains a solvent and has a viscosity of 15 mPa·s or less at 23°C. The solvent contains at least one first solvent component having a flow activation energy of 17 kJ / mol or more. A method for manufacturing an organic semiconductor device, wherein the solvent further comprises a second solvent component having a viscosity of less than 3 mPa·s at 23°C. [4] A method for producing an organic semiconductor device according to [3], wherein the weight-average molecular weight of the arylamine polymer is 15,000 or more and 50,000 or less. [5] A step of applying and heating the first composition to provide a first functional film, The process includes the step of applying a second composition onto the first functional film to provide a second functional film, The first composition comprises a first functional material, The first functional material comprises an arylamine polymer that does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups. The second composition contains a solvent and has a viscosity of 15 mPa·s or less at 23°C. The solvent contains at least one first solvent component having a viscosity of 3 mPa·s or more at 23°C. The solvent further comprises a second solvent component having a viscosity of less than 3 mPa·s at 23°C. A method for manufacturing an organic semiconductor device, wherein the fluid activation energy of the first solvent component is 17 kJ / mol or more. [6] The method for manufacturing an organic semiconductor device according to any one of [1] to [5], wherein the arylamine polymer has repeating units represented by the following formula (50).

[0014] [ka]

[0015] (In formula (50), Ar 51 This represents a group consisting of one or more linked groups, selected from at least one of an aromatic hydrocarbon group which may have substituents and an aromatic heterocyclic group which may have substituents, and all substituents are groups other than crosslinking groups, polymerization groups, or leaving solubilizing groups. Ar 52represents a divalent group to which one or more groups selected from at least one of a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are linked, the linking being made directly or via a linking group, and all of the substituents are groups other than a crosslinking group, a polymerizable group or a dissociable solubilizing group. Ar 51 and Ar 52 may be bonded directly or via a linking group to form a ring. However, Ar 51 and Ar 52 do not have any of a crosslinking group, a polymerizable group and a dissociable solubilizing group.)

[0016] [7] The method for producing an organic semiconductor device according to [6], wherein the arylamine polymer includes a structure in which a plurality of benzene ring structures are linked in the para position in the main chain, and at least one of the plurality of benzene ring structures has a substituent at at least one of two carbon atoms adjacent to a carbon atom that binds to an adjacent benzene ring structure. [8] The method for producing an organic semiconductor device according to [6] or [7], wherein the repeating unit represented by the formula (50) is represented by the following formula (54).

[0017]

Chemical formula

[0018] (In the formula (54), Ar 51 is the same as Ar 51 in the formula (50), X is -C(R 7 )(R 8 )-, -N(R 9 )- or -C(R 11 )(R 12 )-C(R 13 )(R 14 )-, R 1 and R 2Each of these is independently an alkyl group which may have substituents, and the substituent is a group other than a crosslinking group, a polymerization group, or a detachable solubilizing group. R 7 ~R 9 and R 11 ~R 14 Each of these is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group, and all of the substituents are groups other than crosslinking groups, polymerization groups, or leaving solubilizing groups. a and b are independent integers between 0 and 4. c is an integer between 1 and 3. d is an integer between 0 and 4. R 1 If there are multiple R 1 They may be the same or different. R 2 If there are multiple R 2 They may be the same or different.

[0019] [9] A method for manufacturing an organic semiconductor device according to [8], wherein the value represented by a+b in formula (54) is 1 or greater.

[10] A method for manufacturing an organic semiconductor device according to any one of [1] to [9], wherein the Hansen solubility parameter δP of the first solvent component satisfies the relationship δP < 7.

[11] A method for manufacturing an organic semiconductor device according to any one of [1] to

[10] , wherein two minutes or more are required from the time the second composition is applied onto the first functional film until the solvent evaporates.

[12] The second composition comprises a second functional material different from the first functional material, The method for producing an organic semiconductor device according to any one of [1] to

[11] , wherein the second functional material comprises a low molecular weight aromatic compound having a molecular weight of less than 2000.

[13] A method for manufacturing an organic semiconductor device according to any one of [1] to

[12] , wherein the first functional film is a hole transport layer and the second functional film is a light-emitting layer.

[14] A method for manufacturing an organic semiconductor device according to any one of [1] to

[13] , wherein the heating in the step of providing the first functional film is performed at a temperature lower than the glass transition temperature of the arylamine polymer.

[15] The theoretical surface area (Å) of the first solvent component calculated using the COSMO-RS solvation model. 2 ), volume (Å) 3 A method for manufacturing an organic semiconductor device according to any one of [1] to

[14] , wherein the boiling point (°C) and viscosity at 23°C (mPa·s) satisfy the following relation (A). 32 × viscosity - 4.3 × theoretical surface area + 5.4 × volume - boiling point > 150···(A)

[16] A method for producing an organic semiconductor device according to any one of [1] to

[15] , wherein the total content of the first solvent components in the second composition is 15% by mass or more.

[17] A method for producing an organic semiconductor device according to any one of [1] to

[16] , wherein the first solvent component comprises an aromatic hydrocarbon structure. [Effects of the Invention]

[0020] The present invention allows for the formation of another film on a functional film containing organic materials constituting an organic semiconductor element by wet deposition, without using organic materials that have crosslinking groups, polymerization groups, or desorbable solubilizing groups and can be made insoluble by post-coating treatment. Since the organic materials contained in the functional film can be broadly selected, and the composition for forming the other film on top can also be broadly selected, for example, when the organic semiconductor element is an organic electroluminescent element, it is possible to provide a method for manufacturing an organic electroluminescent element that enables the stacking of functional materials with excellent luminous efficiency, luminous lifetime, and coatability. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is a schematic cross-sectional view showing a typical example of an organic electroluminescent element structure. [Modes for carrying out the invention]

[0022] The inventors have found that the above problems can be solved by using any of the following manufacturing methods (a) to (c).

[0023] (a) A step of applying and heating a first composition to provide a first functional film, and a step of applying a second composition on the first functional film to provide a second functional film, wherein the first composition comprises a first functional material, the first functional material does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups, and has a weight-average molecular weight of 15,000 or more and 50,000 below A method for producing an organic semiconductor device, comprising an arylamine polymer, wherein the second composition comprises a solvent having a viscosity of 15 mPa·s or less at 23°C, and the solvent comprises at least one first solvent component having a viscosity of 3 mPa·s or more at 23°C.

[0024] (b) A method for producing an organic semiconductor device, comprising the steps of: applying and heating a first composition to provide a first functional film; and applying a second composition on the first functional film to provide a second functional film, wherein the first composition comprises a first functional material, the first functional material comprises an arylamine polymer that does not have any crosslinking groups, polymerizing groups, or leaving solubilizing groups; the second composition comprises a solvent and has a viscosity of 15 mPa·s or less at 23°C, the solvent comprises at least one first solvent component having a flow activation energy of 17 kJ / mol or more, and the solvent further comprises a second solvent component having a viscosity of less than 3 mPa·s at 23°C.

[0025] (c) A method for manufacturing an organic semiconductor device, comprising the steps of: applying and heating a first composition to provide a first functional film; and applying a second composition on the first functional film to provide a second functional film, wherein the first composition comprises a first functional material, the first functional material comprises an arylamine polymer that does not have any crosslinking groups, polymerization groups, or leaving solubilizing groups; the second composition comprises a solvent and has a viscosity of 15 mPa·s or less at 23°C, the solvent comprises at least one first solvent component having a viscosity of 3 mPa·s or more at 23°C, the solvent further comprises a second solvent component having a viscosity of less than 3 mPa·s at 23°C, and the fluid activation energy of the first solvent component is 17 kJ / mol or more.

[0026] According to the manufacturing method of this embodiment, since it does not use a method in which arylamine polymers are given crosslinking groups, polymerization groups, or leaving solubilizing groups as organic materials and then made insoluble by post-coating treatment, it is possible to reduce adverse effects on the lifespan of the device and the luminous efficiency when it is an organic electroluminescent device, and to realize an organic semiconductor device having a functional film with excellent luminous efficiency and luminous lifetime. Furthermore, since the arylamine polymer does not have any crosslinking groups, polymerization groups, or leaving solubilizing groups, a polymer with a small molecular weight that can suppress viscosity increase with concentration can be used as a functional material, and the first functional film can be obtained by coating and heating.

[0027] The second composition constituting the second functional film has a viscosity of 15 mPa·s or less at 23°C and contains a first solvent component that satisfies a viscosity of 3 mPa·s or more at 23°C, or contains a first solvent component that satisfies a flow activation energy of 17 kJ / mol or more and a second solvent component that satisfies a viscosity of less than 3 mPa·s at 23°C. Therefore, even if the underlying first functional film does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups, it is possible to prevent the dissolution of the first functional film and the deterioration of performance due to the mixing of dissolved components into the second functional film during the industrially required immersion time.

[0028] According to the manufacturing method using the first and second compositions in this embodiment, the first functional film is made using a first functional material that does not contain structures that degrade properties, and when the second composition is applied to the first functional film to form the second functional film, the elution of the first functional material and its contamination into the second functional film can be prevented, thereby improving the properties. Structures that degrade properties include crosslinking groups, polymerization groups, and detachable solubilizing groups, and in the case of an organic semiconductor device that is an organic electroluminescent device, such properties refer to luminescence properties. Furthermore, the above manufacturing method enables long-term insoluble durability of the first functional material, making it easy to apply to large substrates.

[0029] Other benefits include the elimination of the need for washing after the formation of the first functional film when forming a high-purity second functional film, and the ability to relax the heating conditions (temperature and time) previously used for insolubilization. Furthermore, even if the molecular weight of the first functional material is reduced, the resulting deterioration of insolubility durability can be suppressed. As a result, it becomes possible to use a material with a small molecular weight for the first functional material and realize processes that tend to increase the viscosity of the first composition, such as high-resolution processing and thick-film lamination.

[0030] The present invention will be described in detail below with reference to specific examples, but is not limited to these examples.

[0031] <First functional membrane, second functional membrane> The first functional film is a film obtained by coating and heating the first composition, and a second functional film is formed on this film. In the case of the organic electroluminescent device shown in Figure 1, the first functional film may be, for example, a hole injection layer 3 formed on the anode 2, or a hole transport layer 4 formed on the hole injection layer 3.

[0032] The second functional film is a functional film obtained by coating the surface of the first functional film with the second composition. In the case of the organic electroluminescent device shown in Figure 1, examples include a hole transport layer 4 formed on the hole injection layer 3, or a light-emitting layer 5 formed on the hole transport layer 4.

[0033] <First Composition> The first composition comprises a first functional material, the first functional material containing an arylamine polymer that does not have any crosslinking groups, polymerization groups, or leaving solubilizing groups. It also typically contains a solvent (organic solvent). The first composition may contain one type of the above-mentioned arylamine polymer as the first functional material, or it may contain two or more types in any combination and any ratio. The first composition may contain functional materials other than the first functional material, such as electron-accepting compounds and charge-transporting materials described later.

[0034] <First functional material> The first functional material is an arylamine polymer that does not have any crosslinking groups, polymerization groups, or leaving solubilizing groups, and is, for example, a polymer having repeating units represented by the following formula (50).

[0035] [ka]

[0036] (In formula (50), Ar 51 This represents a group consisting of one or more linked groups, selected from at least one of an aromatic hydrocarbon group which may have substituents and an aromatic heterocyclic group which may have substituents, and all substituents are groups other than crosslinking groups, polymerization groups, or leaving solubilizing groups. Ar 52 This represents a divalent group formed by linking one or more groups selected from at least one of a substituted divalent aromatic hydrocarbon group and a substituted divalent aromatic heterocyclic group, wherein the linking is made directly or via linking groups, and the substituents are all groups other than crosslinking groups, polymerization groups, or leaving solubilizing groups. Ar 51 and Ar 52 These may be directly or via linking groups to form a ring. However, Ar 51 Ar 52 It does not have any crosslinking groups, polymerization groups, or leaving solubilizing groups.

[0037] (crosslinking group) The arylamine polymer used in the first functional material does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups. Here, a crosslinking group refers to a group that, upon irradiation with heat and / or active energy rays, reacts with other crosslinking groups located in its vicinity to form a new chemical bond. In this case, the reacting group may be the same as the crosslinking group or a different group.

[0038] Examples of crosslinking groups, though not limited to them, include groups containing alkenyl groups, groups containing conjugated diene structures, groups containing alkynyl groups, groups containing oxirane structures, groups containing oxetane structures, groups containing aziridine structures, azide groups, groups containing maleic anhydride structures, groups containing alkenyl groups bonded to aromatic rings, and cyclobutene rings fused to aromatic rings. Specific examples of crosslinking groups include, for example, groups selected from the following group of crosslinking groups T.

[0039] (Bridging group T)

[0040] [ka]

[0041] [ka]

[0042] In the above-mentioned group of bridged structures T, R 3 R represents an alkyl group having 1 to 4 carbon atoms. From the viewpoint of easily forming an oxetane ring, 3 A methyl group or an ethyl group is particularly preferred. XL n represents a methylene group, an oxygen atom, or a sulfur atom. XL This represents an integer from 0 to 5. XL If there are multiple instances, they may be the same or different, nXL If multiple such groups exist, they may be identical or different. * and *1 represent the bonding positions. These bridging groups may have substituents.

[0043] (polymerization group) The polymerization groups that are not present in the arylamine polymer used in the first functional material refer to the functional groups that undergo polymerization reactions in the reaction of polymerizing monomers, which is a common practice.

[0044] (Leaving solubilizing group) The detachable solubilizing groups that are not present in the arylamine polymer used in the first functional material are groups that are soluble in a solvent and thermally dissociate from the bonded group (e.g., a hydrocarbon ring) above a certain temperature (e.g., 70°C or higher). The dissociation of such detachable solubilizing groups reduces the solubility of the polymer in the solvent. Examples of leaving-release solubilizing groups include the "thermally dissociable solubilizing group" described in Japanese Patent Publication No. 2010-059417.

[0045] (Ar 52 (Main chain) In the repeating unit represented by the above formula (50), Ar 52 This represents a group formed by linking one or more groups, selected from at least one of a divalent aromatic hydrocarbon group which may have substituents and a divalent aromatic heterocyclic group which may have substituents. When multiple selected groups are linked, they may be directly linked or linked via linking groups. Here, the substituents that the aromatic hydrocarbon group and the aromatic heterocyclic group may have are substituents other than crosslinking groups, polymerization groups, or leaving solubilizing groups, and groups similar to those of substituent group Z described later are preferred. In this specification, crosslinking groups, polymerization groups, and leaving solubilizing groups may be collectively referred to as "crosslinking groups, etc."

[0046] The aromatic hydrocarbon group preferably has 6 to 60 carbon atoms, and specifically includes a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluorantene ring, fluorene ring, etc., which are 6-membered monocyclic or 2-5 fused ring divalent groups or groups in which multiple such groups are linked. When multiple groups are linked, 2 to 10 The basis of Examples include linked divalent groups, and it is preferable that the divalent group consists of 2 to 5 linked groups. For example, "divalent group of a benzene ring" means "a benzene ring having a divalent free valency," that is, a phenylene group.

[0047] The aromatic heterocyclic group is preferably a divalent monocyclic or 2-4 fused ring with 5-6 membered rings, or a group formed by linking multiple such rings, such as a furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrrole ring, pyrrolopyrrole ring, thienopyrrole ring, thienopyrrole ring, phlopyrrole ring, phlofuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, sinnoline ring, quinoxaline ring, phenanthidine ring, perimidine ring, quinazoline ring, quinazolinone ring, and azulene ring. When multiple units are linked together, a divalent group consisting of 2 to 10 linked groups is preferred, and a divalent group consisting of 2 to 5 linked groups is more preferred.

[0048] The divalent group, which is formed by the direct linkage or via a linking group of multiple aromatic hydrocarbon groups or aromatic heterocyclic groups that may have substituents, may be a group in which multiple identical groups are linked, or a group in which multiple different groups are linked. Preferably, the group to be linked is a divalent group in which 2 to 10 groups are linked, and more preferably a divalent group in which 2 to 5 groups are linked.

[0049] (Ar 51 (Side chain) In the repeating unit represented by the above formula (50), Ar 51 This represents a group consisting of one or more linked groups, selected from at least one of an aromatic hydrocarbon group which may have substituents and an aromatic heterocyclic group which may have substituents. Here, the substituents which the aromatic hydrocarbon group and the aromatic heterocyclic group may have are substituents other than crosslinking groups, polymerization groups, or leaving solubilizing groups, and groups similar to those of substituent group Z described later are preferred.

[0050] The aromatic hydrocarbon group is preferably one with 6 to 60 carbon atoms, and specifically, examples include monovalent groups of 6-membered rings 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, or groups in which multiple such groups are linked. When multiple groups are linked, examples include monovalent groups with 2 to 10 linked groups, and it is preferable that the group has 2 to 5 linked groups. For example, "monovalent group of a benzene ring" means "a benzene ring with a monovalent free valency," that is, a phenyl group.

[0051] The aromatic heterocyclic group is preferably a monovalent group of a 5-6 membered ring or a 2-4 fused ring, such as a furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, phlopyrrole ring, phlofuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, sinnoline ring, quinoxaline ring, phenanthidine ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring, etc., or a group in which multiple such groups are linked. When multiple units are linked together, a monovalent group consisting of 2 to 10 linked groups is preferred, and a monovalent group consisting of 2 to 5 linked groups is more preferred.

[0052] The monovalent group, which consists of multiple optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups, may consist of multiple identical groups or multiple different groups. Preferably, the group to be joined consists of 2 to 10 monovalent groups, and more preferably, 2 to 5 monovalent groups.

[0053] Ar 51 From the standpoint of excellent charge transport properties and durability, aromatic hydrocarbon groups which may have substituents other than crosslinking groups are preferred, and among these, monovalent groups of benzene rings or fluorene rings which may have substituents other than crosslinking groups are more preferred, i.e., phenyl groups or fluorenyl groups which may have substituents other than crosslinking groups are more preferred, fluorenyl groups which may have substituents other than crosslinking groups are even more preferred, and 2-fluorenyl groups which may have substituents other than crosslinking groups are particularly preferred.

[0054] Ar 51Other substituents besides the crosslinking groups 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. Preferably, the substituents are groups selected from the substituent group Z described below, with alkyl groups, alkoxy groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups being more preferred, and alkyl groups being even more preferred.

[0055] Ar 51 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 the 9-position of the 2-fluorenyl group is substituted with an alkyl group is preferred, and a 9,9'-dialkyl-2-fluorenyl group substituted with two alkyl groups is particularly preferred.

[0056] The fluorenyl group in which at least one of the 9th and 9' positions is substituted with an alkyl group tends to have improved solubility in solvents and durability of the fluorene ring. Furthermore, the fluorenyl group in which both the 9th and 9' positions are substituted with alkyl groups tends to have even improved solubility in solvents and durability of the fluorene ring.

[0057] Also, Ar 51 From the viewpoint of solubility in the coating solvent, it is also preferable that it be a spirobifluorenyl group.

[0058] Also, Ar 51 Ar 52 They may be bonded directly or via a linking group to form a ring.

[0059] (Content of repeating units represented by formula (50)) In the polymer contained in the first functional film, the content of the repeating unit represented by formula (50) is not particularly limited, but the repeating unit represented by formula (50) is usually contained in the polymer in an amount of 10 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more.

[0060] The polymer contained in the first functional film may consist only of repeating units represented by formula (50), that is, 100 mol%, but may also contain repeating units other than those represented by formula (50) in order to balance the various performance characteristics when used as an organic electroluminescent element. In that case, the content of repeating units represented by formula (50) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

[0061] (terminal group) In this specification, an 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. In the first functional film, the end group of the polymer containing the repeating unit represented by formula (50) is preferably a hydrocarbon group. From the viewpoint of charge transport properties, hydrocarbon groups having 1 to 60 carbon atoms are preferred, hydrocarbon groups having 1 to 40 carbon atoms are more preferred, and hydrocarbon groups having 1 to 30 carbon atoms are even more preferred.

[0062] Examples of hydrocarbon groups include the following: 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 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl groups; A linear, branched, or cyclic alkenyl group, such as a vinyl group, having typically 2 to 24 carbon atoms, preferably 12 or fewer; A linear or branched alkynyl group, such as an ethynyl group, having typically 2 to 24 carbon atoms, preferably 12 or fewer; Aromatic hydrocarbon groups, such as phenyl groups and naphthyl groups, which typically have 6 to 36 carbon atoms, preferably 24 or fewer.

[0063] These hydrocarbon groups may have further substituents, and the substituents that may be present 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.

[0064] The terminal group is preferably an alkyl group or an aromatic hydrocarbon group, and more preferably an aromatic hydrocarbon group, from the viewpoint of charge transport and durability.

[0065] (Substituent group Z) The substituent group Z consists of alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryloxy groups, heteroaryloxy groups, alkoxycarbonyl groups, dialkylamino groups, diarylamino groups, arylalkylamino groups, acyl groups, halogen atoms, haloalkyl groups, alkylthio groups, arylthio groups, silyl groups, siloxy groups, cyano groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups. These substituents may include linear, branched, or cyclic structures.

[0066] More specifically, the substituent group Z includes the following structures. A linear, branched, or cyclic alkyl group having 1 or more carbon atoms, preferably 4 or more, 24 or less, preferably 12 or less, more preferably 8 or less, and more preferably 6 or less. Specific examples include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group, dodecyl group, and the like. An alkoxy group having 1 to 24 carbon atoms, preferably 12 or fewer. Specific examples include a methoxy group and an ethoxy group. An aryloxy group or heteroaryloxy group having 4 or more carbon atoms, preferably 5 or more, and 36 or less, preferably 24 or less. Specific examples include a phenoxy group, a naphthoxy group, a pyridyloxy group, and the like. An alkoxycarbonyl group having 2 or more and 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples include a methoxycarbonyl group, an ethoxycarbonyl group, etc. A dialkylamino group having 2 or more and 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples include a dimethylamino group, a diethylamino group, etc. A diarylamino group having 10 or more, preferably 12 or more carbon atoms and 36 or less, preferably 24 or less carbon atoms. Specific examples include a diphenylamino group, a ditolylamino group, an N-carbazolyl group, etc. An arylalkylamino group having 7 or more and 36 or less carbon atoms, preferably 24 or less carbon atoms. Specific examples include a phenylmethylamino group. An acyl group having 2 or more and 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples include an acetyl group, a benzoyl group. A halogen atom such as a fluorine atom, a chlorine atom; A haloalkyl group having 1 or more and 12 or less carbon atoms, preferably 6 or less carbon atoms. Specific examples include a trifluoromethyl group, etc. An alkylthio group having 1 or more and 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples include a methylthio group, an ethylthio group, etc. An arylthio group having 4 or more, preferably 5 or more carbon atoms and 36 or less, preferably 24 or less carbon atoms. Specifically, a phenylthio group, a naphthylthio group, a pyridylthio group, etc. are included. A silyl group having usually 2 or more, preferably 3 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms. Specific examples include a trimethylsilyl group, a triphenylsilyl group, etc. A siloxy group having 2 or more, preferably 3 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms. Specific examples include a trimethylsiloxy group, a triphenylsiloxy group, etc. A cyano group. An aromatic hydrocarbon group having 6 or more and 36 or less carbon atoms, preferably 24 or less carbon atoms. Specific examples include a phenyl group, a naphthyl group, etc. An aromatic heterocyclic group having 3 or more carbon atoms, preferably 4 or more carbon atoms, and 36 or less carbon atoms, preferably 24 or less carbon atoms. Specific examples include a thienyl group, a pyridyl group, and the like. The above substituents may include any of linear, branched or cyclic structures.

[0067] Among the above substituent groups Z, preferably, an alkyl group, an alkoxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group. From the viewpoint of charge transport property, it is more preferable not to have a substituent. In addition, each substituent of the above substituent group Z may further have a substituent. Examples of such substituents include the same ones as the above substituent group Z. The substituent that may further be present is preferably absent or an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, and more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, or a phenyl group. From the viewpoint of charge transport property, it is more preferable not to have a further substituent.

[0068] (Preferred Ar 51 ) In addition, as the polymer, at least one of Ar in the repeating unit represented by the above formula (50) 51 is preferably a group represented by the following formula (51), the following formula (52), or the following formula (53).

[0069] (Preferred Ar 51 : Formula (51))

[0070]

Chemical formula

[0071] (In formula (51), * represents a bond with N of the main chain of formula (50), Ar 53 、Ar 54Each of these independently represents a divalent group formed by linking one or more groups selected from at least one of optionally substituted divalent aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, wherein the linking is made directly or via linking groups. Ar 55 represents a monovalent group formed by linking one or more groups selected from at least one of optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, wherein the linking is made directly or via linking groups. Ar 56 (This represents a hydrogen atom or substituent.)

[0072] Here, each aromatic hydrocarbon group and each aromatic heterocyclic group may have substituents, and Ar when it is a substituent. 56 These are substituents other than crosslinking groups.

[0073] (Ar 53 Ar 54 ) In the group represented by formula (51) above, Ar 53 Ar 54 Each of these independently represents a divalent group formed by linking one or more groups selected from at least one of optionally substituted divalent aromatic hydrocarbon groups and optionally substituted divalent aromatic heterocyclic groups, wherein the linking is made directly or via linking groups. Preferably, it is a divalent aromatic hydrocarbon group which may have substituents, or a group in which multiple divalent aromatic hydrocarbon groups which may have substituents are linked together. Here, the substituents which the aromatic hydrocarbon group and the aromatic heterocyclic group may have are substituents other than bridging groups, and groups similar to those of substituent group Z are preferred. Ar 53 and Ar 54 The aromatic hydrocarbon group and aromatic heterocyclic group are the Ar 52 Similar aromatic hydrocarbon groups and aromatic heterocyclic groups can be used.

[0074] A divalent group formed by the direct or via linking groups of multiple groups selected from at least one of an aromatic hydrocarbon group which may have substituents and an aromatic heterocyclic group which may have substituents may be a group in which multiple identical groups are linked, or a group in which multiple different groups are linked. When multiple divalent groups are linked together, a divalent group consisting of 2 to 10 linked groups is preferred, and a divalent group consisting of 2 to 5 linked groups is preferred.

[0075] Ar 53 The group preferably consists of one or two to six substituted divalent aromatic hydrocarbon groups, more preferably one or two to four substituted divalent aromatic hydrocarbon groups, more preferably one or two to four substituted phenylene rings, and particularly preferably biphenylene consisting of two substituted phenylene rings. Furthermore, when multiple divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are linked together, it is preferable that the linked divalent aromatic hydrocarbon groups are bonded in such a way that they are not conjugated. Specifically, it is preferable to include a 1,3-phenylene group or a group having substituents that form a twisted structure due to the steric effect of the substituents.

[0076] Ar 53 The substituents that may be present are substituents other than crosslinking groups, and groups similar to those of substituent group Z are preferred. Preferably, Ar 53 It has no substituents.

[0077] Ar 54 From the viewpoint of excellent charge transport properties and durability, a group consisting of one divalent aromatic hydrocarbon group or a group in which multiple divalent aromatic hydrocarbon groups, which may be the same or different, are linked together is preferred, and the divalent aromatic hydrocarbon group may have substituents. When multiple divalent aromatic hydrocarbon groups are linked together, the number of divalent aromatic hydrocarbon groups is preferably 2 to 10, more preferably 6 or less, and particularly preferred to be 3 or less from the viewpoint of film stability.

[0078] Preferred aromatic hydrocarbon structures include a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring, with benzene rings and fluorene rings being more preferred. Preferred multiple linked groups include groups consisting of 2 to 4 optionally substituted phenylene rings, or groups consisting of an optionally substituted phenylene ring and an optionally substituted fluorene ring. It is also preferable to have only one optionally substituted phenylene ring. From the viewpoint of broadening the LUMO, biphenylenes consisting of two optionally substituted phenylene rings are particularly preferred.

[0079] Ar 54 The substituents that may be present include any of the substituent group Z mentioned above, or a combination thereof. The substituents are preferably other than the N-carbazolyl group, indrocarbazolyl group, and indenocarbazolyl group, and more preferably the phenyl group, naphthyl group, and fluorenyl group. It is also preferable that the substituent has no substituents.

[0080] (Ar 55 ) Ar 55 This represents a monovalent group formed by linking one or more groups selected from at least one of optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, wherein the linkage is made directly or via linking groups. Preferably, it is an optionally substituted monovalent aromatic hydrocarbon group or a group formed by linking multiple optionally substituted monovalent aromatic hydrocarbon groups. Here, the substituents that the aromatic hydrocarbon group and the aromatic heterocyclic group may have are substituents other than crosslinking groups, and groups similar to those of substituent group Z are preferred.

[0081] When multiple groups selected from at least one of the aromatic hydrocarbon group and the aromatic heterocyclic group are linked, a monovalent group consisting of 2 to 10 linked groups is preferred, and a monovalent group consisting of 2 to 5 linked groups is more preferred. As for aromatic hydrocarbon groups and aromatic heterocyclic groups, the above Ar51 The same aromatic hydrocarbon groups and aromatic heterocyclic groups can be used.

[0082] Ar 55 Preferably, it has a structure represented by any of the following Scheme 2. Further, from the viewpoint of distributing the LUMO of the molecule, a structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-16, and e-1 to e-4 shown in the following Scheme 2 is preferable. From the viewpoint of promoting the broadening of the LUMO of the molecule by further having an electron-withdrawing group, a structure selected from a-1 to a-4, b-1 to b-9, d-1 to d-12, and e-1 to e-4 is preferable. Further, from the viewpoint of effects such as having a high triplet level and confining excitons formed in the light-emitting layer when the second functional film is used as the light-emitting layer, a structure selected from a-1 to a-4, d-1 to d-12, and e-1 to e-4 is preferable. Also, from the viewpoints of being easily synthesized and having excellent stability, d-1 and d-10 are more preferable, and the benzene ring structure of d-1 is particularly preferable.

[0083] Furthermore, these structures may have substituents. In the structural formula, “-*” represents the bonding position with Ar 54 When there are a plurality of “-*”, any one of them represents the bonding position with Ar 54

[0084]

Chemical formula

[0085]

Chemical formula

[0086] (R 31 and R 32 ) R in Scheme 2 31 and R 32 ​is preferably a linear, branched or cyclic alkyl group which may independently have a substituent. The number of carbon atoms of the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, it is preferably 1 or more and 6 or less, more preferably 3 or less, and still more preferably a methyl group or an ethyl group.

[0087] R 31 and R 32 may be the same or different, and when there are a plurality of R 31 and R 32 respectively, they may also be the same or different, but since the charge can be uniformly distributed around the nitrogen atom and the synthesis is easier, all R 31 and R 32 are preferably the same group.

[0088] Ar 55 As the substituent that may be possessed, any of the above-mentioned substituent groups Z or a combination thereof can be used. From the viewpoints of durability and charge transportability, it is preferably selected from the same substituents as the substituents that the above-mentioned Ar 54 may have.

[0089] (Ar 56 ) Ar 56 represents a hydrogen atom or a substituent. When Ar 56 is a substituent, it is not particularly limited, but is preferably an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. As a preferred structure, it is the same as the aromatic hydrocarbon structure and aromatic heterocyclic structure exemplified for the above Ar 53 , Ar 54 and is a monovalent structure. However, when Ar 56 is a substituent, it is not a crosslinking group or the like.

[0090] Ar 56When it is a substituent, it is preferable that it is bonded to the 3-position of carbazole from the viewpoint of improving durability. Further, from the viewpoints of improving durability and charge transportability, it is preferably an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and more preferably an aromatic hydrocarbon group which may have a substituent. Ar 56 is preferably a hydrogen atom from the viewpoints of ease of synthesis and charge transportability.

[0091] Ar 56 When Ar is an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, the substituents are the same as the substituents listed in the above-mentioned substituent group Z, the preferable substituents are the same, and the substituents which they may further have are also the same.

[0092] (Preferred Ar 51 : Formula (52)) Ar in the repeating unit represented by the above formula (50) 51 It is also preferable that at least one of them is a group represented by the following formula (52). The reason is that in the two carbazole structures in the following formula (52), the LUMO is distributed in the aromatic hydrocarbon group or aromatic heterocyclic group between the nitrogen atoms of each other, so the influence on the main chain amine in the formula (50) is suppressed, and it is considered that the durability against the electrons and excitons of the main chain amine is improved.

[0093]

Chemical formula

[0094] (In formula (52), Ar 61 and Ar 62 each independently represents a divalent group in which one group or a plurality of groups selected from at least one of a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are connected, and the connection is made directly or via a linking group. Ar 63~Ar 65 Each of these is independently a hydrogen atom or a substituent. * indicates the bond position to the nitrogen atom in equation (50).

[0095] However, each aromatic hydrocarbon group and each aromatic heterocyclic group may have substituents, and Ar in the case of substituents 63 ~Ar 65 These are substituents other than crosslinking groups.

[0096] (Ar 63 ~Ar 65 ) Ar 63 ~Ar 65 These are, independently, Ar in equation (51). 56 It is similar to that.

[0097] (Ar 62 ) Ar 62 This represents a divalent group formed by linking one or more groups selected from at least one of optionally substituted divalent aromatic hydrocarbon groups and optionally substituted divalent aromatic heterocyclic groups, wherein the linking is made directly or via linking groups. Preferably, it is an optionally substituted divalent aromatic hydrocarbon group or a group formed by linking multiple optionally substituted divalent aromatic hydrocarbon groups. Ar 62 The specific structure is shown in equation (51) Ar 54 It is similar to that.

[0098] Ar 62 Specific preferred groups are divalent groups of a benzene ring, naphthalene ring, anthracene ring, or fluorene ring, or groups in which multiple such groups are linked; more preferably, divalent groups of a benzene ring, divalent groups of a fluorene ring, or groups in which multiple such groups are linked; particularly preferably, 1,4-phenylene groups in which a benzene ring is linked at the 1,4 positions divalently; 2,7-fluorenylene groups in which a fluorene ring is linked at the 2,7 positions divalently; or groups in which multiple such groups are linked; and most preferably, groups containing "1,4-phenylene group-2,7-fluorenylene group-1,4-phenylene group-".

[0099] Ar 62 In these preferred structures, the phenylene group has no substituents other than at the linking position, which is due to the steric effect of substituents on Ar 62 It is preferable that no twisting occurs. Furthermore, it is preferable for the fluorenylene group to have substituents at the 9,9' position, from the viewpoint of improving solubility and the durability of the fluorene structure.

[0100] (Ar 61 ) Ar 61 In equation (52), Ar 53 It is a similar group, and the preferred structure is also similar.

[0101] (Preferred Ar 51 :Formula (53)) Ar in the repeating unit represented by the above formula (50) 51 It is also preferable that at least one of these is a group represented by the following formula (53).

[0102] [ka]

[0103] (In formula (53), * represents the bond with N in the main chain of equation (50), Ar 71 This represents a divalent aromatic hydrocarbon group which may have substituents, Ar 72 and Ar 73 Each of these independently represents a divalent group formed by linking one or more groups selected from at least one of optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, wherein the linking is made directly or via linking groups. The ring HA is an aromatic heterocycle containing a nitrogen atom, and X 2 , Y 2 Each of these independently represents either a C atom or an N atom, and X 2 or Y 2 However, in the case of a carbon atom, it may have substituents.

[0104] (Ar 71 ) Ar 71 In equation (51), Ar 53 It is a similar base. Ar 71 Preferably, the group consists of one optionally substituted divalent aromatic hydrocarbon group or a group in which 2 to 10 optionally substituted divalent aromatic hydrocarbon groups are linked together. More preferably, the group consists of one optionally substituted divalent aromatic hydrocarbon group or a group in which 2 to 8 optionally substituted divalent aromatic hydrocarbon groups are linked together. In particular, a group consisting of 2 to 6 optionally substituted divalent aromatic hydrocarbon groups is even more preferable. Ar 71 In particular, a group consisting of 2 to 6 linked benzene rings, which may have substituents, is preferred, and a quaterphenylene group consisting of 4 linked benzene rings, which may have substituents, is most preferred.

[0105] Also, Ar 71 It is preferable that it contains at least one benzene ring linked at the 1,3 positions, which are non-conjugated sites, and more preferably two or more. Ar 71 In the case of a group consisting of multiple linked divalent aromatic hydrocarbon groups, which may have substituents, it is preferable from the viewpoint of charge transportability or durability that all of them are directly bonded together. Therefore, Ar 71 The preferred structure for connecting the nitrogen in the polymer's main chain with the ring HA in formula (53) is shown in the following structural formula. In the following structural formula, the two "-*" symbols represent the bonding sites, one of which is bonded to the nitrogen in the polymer's main chain and the other to the ring HA in formula (53). Either of the two "-*" symbols may be bonded to the nitrogen in the polymer's main chain or to the ring HA.

[0106] [ka]

[0107] Ar71 As substituents that may be present, any of the substituent group Z or a combination thereof can be used. 71 A preferred range of substituents that may be present is Ar in formula (51) above. 53 It is a similar group, and a more preferred structure is the Ar 53 It is similar to the preferred group.

[0108] (X 2 and Y 2 ) X 2 and Y 2 Each of these independently represents either a carbon (C) atom or a nitrogen (N) atom. 2 or Y 2 However, in the case of a carbon atom, it may have substituents. From the perspective of making it easier to localize LUMO around the ring HA, X 2 , Y 2 Preferably, all of these are N atoms.

[0109] X 2 or Y 2 If the atom is a C atom, any of the substituents in the substituent group Z or any combination thereof can be used. From the viewpoint of charge transport, it is even more preferable that the atom has no substituents.

[0110] (Ar 72 and Ar 73 ) Ar 72 and Ar 73 Each of these independently represents a divalent group consisting of one or more linked groups, selected from at least one of optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups, wherein the linkage is made directly or via linking groups.

[0111] From the perspective of distributing the LUMO of molecules, Ar 72 and Ar 73 Each of these independently corresponds to Ar in equation (51). 55It is preferable to have the same structure as the structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-16, and e-1 to e-4 shown in the above scheme 2. Furthermore, from the viewpoint of promoting the expansion of the molecular LUMO by having electron-withdrawing groups, structures selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-12, and e-1 to e-4 are preferred. Furthermore, when a second functional film with a higher triplet level is used as the light-emitting layer, a structure selected from a-1 to a-4, d-1 to d-12, and e-1 to e-4 is preferred from the viewpoint of confining excitons formed in the light-emitting layer. Furthermore, from the viewpoint of preventing molecular aggregation, structures selected from d-1 to d-12 and e-1 to e-4 are even more preferable. From the viewpoint of being easy to synthesize and having excellent stability, Ar 72 and Ar 73 The structure is the same as , and d-1 or d-10 is preferred, with the benzene ring structure of d-1 being particularly preferred.

[0112] These structures may also have substituents. In the structural formula, "-*" represents a bonding site to the ring HA. If there are multiple "-*" symbols, it indicates that at least one of them is a bonding site to the ring HA.

[0113] Ar 72 and Ar 73 As substituents that may be present, any of those shown above as (substituent group Z) or a combination thereof can be used. From the viewpoint of durability and charge transportability, substituents other than crosslinking groups, etc., and groups similar to those in substituent group Z above are preferred.

[0114] (Preferred main chain) The arylamine polymer having the repeating unit represented by formula (50) above preferably includes a structure in which a plurality of benzene ring structures are linked at the para position in the main chain, and it is preferable that at least one of the plurality of benzene ring structures has a substituent on at least one of the two carbon atoms located next to the carbon atom bonded to the adjacent benzene ring structure. Either one or both of the two adjacent benzene ring structures may be part of a fused ring. This is because it lowers the glass transition temperature of the arylamine polymer and makes the layer easier to solidify.

[0115] The repeating unit represented by formula (50) above is preferably the repeating unit represented by formula (54), formula (55), formula (56), or formula (57), with the repeating unit represented by formula (54) being more preferred.

[0116] (The repeating unit represented by equation (54))

[0117] [ka]

[0118] (In formula (54), Ar 51 This is Ar in equation (50) above. 51 It is similar to, X is -C(R 7 )(R 8 )-,-N(R 9 )- or -C(R 11 )(R 12 )-C(R 13 )(R 14 )- and, R 1 and R 2 Each of these is an alkyl group which may have substituents other than crosslinking groups, R 7 ~R 9 and R 11 ~R 14Each of these is independently an alkyl group which may have substituents other than a hydrogen atom or a bridging group, an aralkyl group which may have substituents other than a bridging group, or an aromatic hydrocarbon group which may have substituents other than a bridging group. a and b are independent integers between 0 and 4. c is an integer between 1 and 3. d is an integer between 0 and 4. R 1 If there are multiple R 1 They may be the same or different. R 2 If there are multiple R 2 They may be the same or different.

[0119] (R 1 , R 2 ) R in the repeating unit represented by the above formula (54) 1 and R 2 Each of these is an alkyl group that may have substituents other than crosslinking groups, etc., independently.

[0120] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but to maintain the solubility of the polymer, it is preferably 1 or more, preferably 8 or less, more preferably 6 or less, and even more preferably 3 or less. The alkyl group is more preferably a methyl group or an ethyl group.

[0121] R 1 If there are multiple R 1 They may be the same or different, R 2 If there are multiple R 2 They may be the same or different. Note that R 1 The cases in which there are multiple R include when a is an integer greater than or equal to 2, when c is an integer greater than or equal to 2, and when both are true. In any of these cases, there are multiple R 1 They may be the same or different. 2 The same applies to R. 2The cases where there are multiple R include when b is an integer greater than or equal to 2, when d is an integer greater than or equal to 2, and when both are true. In any of these cases, there are multiple R 2 They may be the same or different. Because the charge can be uniformly distributed around the nitrogen atom, and furthermore, it is easy to synthesize, all R 1 and R 2 It is preferable that they are the same group.

[0122] R 1 , R 2 The alkyl group may have substituents other than crosslinking groups, etc. Substituents other than crosslinking groups, etc. are described later in R 7 ~R 9 and R 11 ~R 14 Preferred groups include alkyl groups, aralkyl groups, and aromatic hydrocarbon groups. R 1 , R 2 From the viewpoint of lowering the voltage, it is most preferable that the alkyl group does not have substituents.

[0123] (R 7 ~R 9 and R 11 ~R 14 ) R 7 ~R 9 and R 11 ~R 14 Each of these is independently an alkyl group which may have substituents other than a hydrogen atom or a bridging group, an aralkyl group which may have substituents other than a bridging group, or an aromatic hydrocarbon group which may have substituents other than a bridging group.

[0124] The alkyl group is not particularly limited, but it is preferable that it has 1 or more carbon atoms, preferably 24 or fewer, more preferably 8 or fewer, and even more preferably 6 or fewer, as it tends to improve the solubility of the polymer. The alkyl group may also have a linear, branched, or cyclic structure.

[0125] Examples of the alkyl group include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, dodecyl group, and the like.

[0126] The aralkyl group is not particularly limited, but it tends to improve the solubility of the polymer, so it is preferable that it has 5 or more carbon atoms, preferably 60 or fewer, and more preferably 40 or fewer.

[0127] Examples of the aralkyl group 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.

[0128] The aromatic hydrocarbon group is not particularly limited, but it is preferable that it has 6 or more carbon atoms, preferably 60 or fewer, and more preferably 30 or fewer, as it tends to improve the solubility of the polymer.

[0129] Examples of the aromatic hydrocarbon group include monovalent groups of 6-membered rings 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, or groups in which multiple such groups are linked together.

[0130] From the viewpoint of improving charge transport and durability, R 7 ~R 9 R is preferably a methyl group or an aromatic hydrocarbon group. 7 and R8 It is more preferably a methyl group, R 9 It is more preferable that it be a phenyl group.

[0131] R 7 ~R 9 and R 11 ~R 14 The alkyl group, aralkyl group, and aromatic hydrocarbon group may have substituents other than the crosslinking group. The substituents other than the crosslinking group are as described above in R 7 ~R 9 and R 11 ~R 14 The groups listed above are preferred alkyl groups, aralkyl groups, and aromatic hydrocarbon groups.

[0132] R 7 ~R 9 and R 11 ~R 14 From the viewpoint of lowering the voltage, it is most preferable that the alkyl group, aralkyl group, and aromatic hydrocarbon group in the given molecule are free of substituents.

[0133] (a, b, c, and d) In the repeating unit represented by formula (54) above, a and b are each independent integers between 0 and 4. The value represented by a + b is preferably 1 or greater, and more preferably a and b are each 2 or less, and more preferably both a and b are 1. In a structure where a is 1 or greater, c is independently defined by c phenylene groups when c is 1 or greater, and in a structure where b is 1 or greater, d is independently defined by d phenylene groups when d is 1 or greater.

[0134] When the value represented by a+b is 1 or greater, the aromatic rings of the main chain are twisted due to steric hindrance, resulting in excellent solubility of the polymer in the solvent. Conversely, coatings formed by wet deposition and heat-treated tend to exhibit excellent solvent insolubility. Therefore, when the value represented by a+b is 1 or greater, and another organic layer, i.e., a second functional film, is formed on the first functional film by wet deposition, the elution of polymers such as arylamine polymers contained in the first composition into the second composition containing an organic solvent is suppressed. As a result, the impact on the formed second functional film is reduced, and the operating life of the organic semiconductor device is expected to be further extended.

[0135] In the repeating unit represented by the above formula (54), c is an integer from 1 to 3, and d is an integer from 0 to 4. Preferably, c and d are each 2 or less, more preferably c and d are equal, and particularly preferably both c and d are 1, or both c and d are 2.

[0136] If both c and d in the repeating unit represented by the above formula (54) are 1, or both c and d are 2, and both a and b are 2 or 1, then R 1 and R 2 It is most preferable that they are joined in positions symmetrical to each other.

[0137] Here, R 1 and R 2 The bond between them in symmetrical positions means that, relative to the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure in formula (54), R 1 and R 2 This refers to the symmetrical positioning of the bonds. In this case, a 180-degree rotation around the main chain axis is considered to result in the same structure.

[0138] (X) In equation (54) above, X is -C(R) because of its high stability during charge transport. 7 )(R 8 )- or -N(R 9 )- is preferred, -C(R 7 )(R 8) - is more preferable.

[0139] (Preferred repeating unit) The repeating unit represented by formula (54) above is particularly preferably a repeating unit shown by any of the following formulas (54-1) to (54-4).

[0140] [ka]

[0141] In the above formula, Ar 51 , R 1 , R 2 And X is Ar in equation (54). 51 , R 1 , R 2 And are similar to X, respectively, but R 1 and R 2 They are identical, and R 1 and R 2 It is preferable that they are joined in positions symmetrical to each other.

[0142] (Specific example of a repeating main chain represented by formula (54)) The main chain structure excluding the nitrogen atom in formula (54) above is not particularly limited, but examples include the following structures.

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] [ka]

[0148] [ka]

[0149] [ka]

[0150] (The repeating unit represented by equation (55))

[0151] [ka]

[0152] (In formula (55), Ar 51 This is Ar in equation (50) above. 51 It is similar to, R 3 and R 6 Each of these is an alkyl group which may have substituents other than crosslinking groups, R 4 and R 5 Each of these is independently an alkyl group which may have substituents other than a crosslinking group, an alkoxy group which may have substituents other than a crosslinking group, or an aralkyl group which may have substituents other than a crosslinking group. l is either 0 or 1. m is either 1 or 2. n is either 0 or 1. p is either 0 or 1, q is either 0 or 1.

[0153] (R 3 , R 6 ) R in the repeating unit represented by the above formula (55) 3 and R6 Each of these is an alkyl group that may have substituents other than crosslinking groups, etc., independently. As an alkyl group, R in formula (54) above 1 and R 2 Similar examples include substituents that may be present and preferred structures of R. 1 and R 2 Similar examples include the above.

[0154] (R 4 , R 5 ) R in the repeating unit represented by the above formula (55) 4 and R 5 Each of these is independently an alkyl group which may have substituents other than a crosslinking group, an alkoxy group which may have substituents other than a crosslinking group, or an aralkyl group which may have substituents other than a crosslinking group.

[0155] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but it is preferably 1 or more, preferably 24 or less, more preferably 8 or less, and even more preferably 6 or less, as this tends to improve the solubility of the polymer.

[0156] Examples of the alkyl group include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, dodecyl group, and the like.

[0157] The alkoxy group is not particularly limited, and is an alkoxy group (-OR 10 ) of R 10 The alkyl group represented by may have a linear, branched, or cyclic structure, and since it tends to improve the solubility of the polymer, it is preferably one or more carbon atoms, preferably 24 or fewer, and more preferably 12 or fewer.

[0158] Examples of such alkoxy groups include methoxy, ethoxy, n-propoxy, n-butoxy, hexyloxy, 1-methylpentyloxy, and cyclohexyloxy groups.

[0159] The aralkyl group is not particularly limited, but it tends to improve the solubility of the polymer, so it is preferable that it has 5 or more carbon atoms, preferably 60 or fewer, and more preferably 40 or fewer.

[0160] Examples of such aralkyl groups 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.

[0161] (l, m, and n) l represents 0 or 1, and n represents 0 or 1.

[0162] l and n are independent of each other, and the value represented by l+n is preferably 1 or greater, more preferably 1 or 2, and even more preferably 2. When the value represented by l+n is within the above range, the solubility of the polymer contained in the first functional film is increased, and precipitation from the first composition containing the polymer tends to be suppressed.

[0163] m represents either 1 or 2. When the organic semiconductor element is an organic electroluminescent element, it is preferable that it be 1, as it can be driven at a low voltage and tends to improve hole injection capability, transport capability, and durability.

[0164] (p and q) p represents 0 or 1, and q represents 0 or 1. Note that when p=1, l=1, and when q=1, n=1. When l=n=1, p and q cannot be 0 at the same time. The fact that p and q cannot be 0 at the same time tends to increase the solubility of the polymer contained in the first functional film and suppress precipitation from the first composition containing the polymer. Furthermore, for the same reasons as in a and b above, it is considered preferable that the operating life of the organic semiconductor device is further extended when the value represented by p+q is 1 or greater.

[0165] (Specific example of a repeating main chain represented by formula (55)) The main chain structure excluding the nitrogen atom in formula (55) is not particularly limited, but examples include the following structures.

[0166] [ka]

[0167] [ka]

[0168] [ka]

[0169] [ka]

[0170] [ka]

[0171] [ka]

[0172] [ka]

[0173] [ka]

[0174] (The repeating unit represented by equation (56))

[0175] [ka]

[0176] (In formula (56), Ar 51 This is Ar in equation (50) above. 51 It is similar to, Ar 41 This represents a divalent group consisting of one or more linked groups, selected from at least one of a divalent aromatic hydrocarbon group which may have substituents other than a bridging group, and a divalent aromatic heterocyclic group which may have substituents other than a bridging group, and the linkage is made directly or via linking groups. R 41 and R 42 Each of these is an alkyl group which may have substituents other than crosslinking groups, t is either 1 or 2. u is either 0 or 1, r and s are independent integers between 0 and 4.

[0177] (R 41 , R 42 ) R in the repeating unit represented by the above formula (56) 41 , R 42 Each of these is an alkyl group that may have substituents other than crosslinking groups, etc., independently.

[0178] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more, preferably 10 or less, more preferably 8 or less, and more preferably 6 or less. The alkyl group is even more preferably a methyl group or a hexyl group.

[0179] R 41 and R 42 If there are multiple R in the repeating unit represented by the above formula (56), then multiple R 41 and R 42 They may be the same or different. 41 Cases where there are multiple R include cases where r is 2 or more, t is 2 or more, or both. 42 The case where there are multiple instances of s is when s is 2 or greater.

[0180] (r, s, t, and u) In the repeating unit represented by formula (56), r and s are each independent integers between 0 and 4. The value represented by r + s is preferably 1 or greater, and furthermore, r and s are each preferably 2 or less. Note that r is independently defined for each of the t phenylene groups when t is 1 or greater, and s is defined when u = 1. If the value represented by r+s is 1 or greater, the operating life of the organic semiconductor device is expected to be even longer for the same reasons as a and b in equation (54) above.

[0181] In the repeating unit represented by the above formula (56), t is 1 or 2, and u is 0 or 1. t is preferably 1, and u is preferably 1.

[0182] (Ar 41 ) Ar 41 This represents a divalent group formed by linking one or more groups selected from at least one of a divalent aromatic hydrocarbon group which may have substituents other than a bridging group, and a divalent aromatic heterocyclic group which may have substituents other than a bridging group, and the linking is made directly or via linking groups.

[0183] Ar 41 The aromatic hydrocarbon group in and of the aromatic hydrocarbon group is Ar in formula (50). 52 Similar groups can be cited. Furthermore, the aromatic hydrocarbon group and the substituents that the aromatic hydrocarbon group may have are preferably the same as those in substituent group Z, and it is even more preferable that the substituents that may be present are the same as those in substituent group Z.

[0184] (Specific examples of repeating units represented by equation (56)) The repeating unit represented by equation (56) is not particularly limited, but for example, the following structure can be considered.

[0185] [ka]

[0186] (The repeating unit represented by equation (57))

[0187] [ka]

[0188] (In formula (57), Ar 51 This is Ar in equation (50) above. 51 It is similar to, R 17 ~R 19 Each of these independently represents an alkyl group which may have substituents other than a crosslinking group, an alkoxy group which may have substituents other than a crosslinking group, an aralkyl group which may have substituents other than a crosslinking group, an aromatic hydrocarbon group which may have substituents other than a crosslinking group, or an aromatic heterocyclic group which may have substituents other than a crosslinking group. f, g, and h each independently represent integers between 0 and 4, and the value expressed by f + g + h is greater than or equal to 1. e represents an integer between 0 and 3.

[0189] (R 17~R 19 ) R 17 ~R 19 In this, the aromatic hydrocarbon group and the aromatic heterocyclic group are each independently of the Ar 51 The aromatic hydrocarbon groups and aromatic heterocyclic groups listed above are similar to these groups, and also include groups other than the bridging groups that these groups may have. of The substituents are the above substituent group. Z and Similar groups are preferred. R 17 ~R 19 The alkyl and aralkyl groups in the R 7 Groups similar to the alkyl and aralkyl groups listed above are preferred, and substituents other than crosslinking groups that may also be present are also preferred. 7 A similar base is preferred. R 17 ~R 19 The alkoxy group in is preferably one of the alkoxy groups listed in substituent group Z above, and any substituents other than bridging groups that may also be present are the same as those in substituent group Z above.

[0190] (f, g, h) f, g, and h each independently represent integers between 0 and 4, and the value expressed by f + g + h is 1 or greater. Note that g is defined independently for each of the e phenylene groups when e is 2 or greater. The value represented by f+h is preferably 1 or greater. The value represented by f+h is preferably 1 or greater, and more preferably f, g, and h are all 2 or less. The value represented by f+h is 1 or greater, and it is even more preferable that both f and h are 1 or less. It is most preferable that both f and h are 1. If both f and h are 1, R 17 and R 19 It is preferable that they are joined in positions symmetrical to each other. Also, R 17 and R 19 It is preferable that it is the same as and more preferably that g is 2. If g is 2, then the two R 18It is most preferable that they are bonded to each other in the para position, and if g is 2, then the two R 18 It is most preferable that they be identical. Here, R 17 and R 19 The term "bonding in symmetrical positions" refers to the following bond positions. However, for notational purposes, a 180-degree rotation around the main chain axis is considered to represent the same structure.

[0191] [ka]

[0192] Furthermore, the repeating unit represented by formula (57) above is preferably the repeating unit represented by formula (58) below.

[0193] (The repeating unit represented by equation (58))

[0194] [ka]

[0195] In the case of the repeating unit represented by the above formula (58), g is preferably 0 or 2. When g=2, the bond positions are preferably 2 and 5. When g=0, i.e., R 18 When there is no steric hindrance, and when g=2 and the bond positions are at positions 2 and 5, i.e., when there are two R's steric hindrances 18 If it is at a diagonal position on the benzene ring to which it is bonded, then R 17 and R 19 It is possible for them to be joined in positions symmetrical to each other.

[0196] Furthermore, it is even more preferable that the repeating unit represented by the above formula (58) is the repeating unit shown in the following formula (59) where e=3.

[0197] (The repeating unit represented by equation (59))

[0198] [ka]

[0199] In the case of the repeating unit represented by formula (59) above, g=0 or 2 is preferable. When g=2, the bond positions are preferably at positions 2 and 5. When g=0, i.e., R 18 When there is no steric hindrance, and when g=2 and the bond positions are at positions 2 and 5, that is, when there are two R's steric hindrances 18 If it is at a diagonal position on the benzene ring to which it is bonded, then R 17 and R 19 It is possible for them to be joined in positions symmetrical to each other.

[0200] (Molecular weight of arylamine polymer) The molecular weight of the arylamine polymer contained in the first functional membrane is described below.

[0201] The weight-average molecular weight (Mw) of the arylamine polymer, preferably an arylamine polymer containing repeating units represented by the above formula (50), is typically 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 200,000 or less, particularly preferably 100,000 or less, and most preferably 50,000 or less. Furthermore, the weight-average molecular weight is typically 2,500 or more, preferably 5,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, and particularly preferably 17,000 or more.

[0202] When the weight-average molecular weight of the arylamine polymer is below the above upper limit, solubility in the solvent is obtained, and it tends to have excellent film-forming properties. Furthermore, when the weight-average molecular weight of the arylamine polymer is above the above lower limit, the decrease in the glass transition temperature, melting point, and vaporization temperature of the arylamine polymer is suppressed, and the heat resistance may be improved. Conventionally, arylamine polymers with a weight-average molecular weight of 15,000 to 50,000 that do not have crosslinking groups were thought to be unable to achieve industrially practical insolubility. By using the composition of the present invention, it is possible to achieve industrially required durability to the upper solvent for 2 minutes or more, preferably 15 minutes or more, even with relatively low temperature and short firing time.

[0203] Furthermore, the number-average molecular weight (Mn) of the arylamine polymer is typically 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, particularly preferably 100,000 or less, and most preferably 40,000 or less. In addition, the number-average molecular weight is typically 2,000 or more, preferably 4,000 or more, more preferably 6,000 or more, and even more preferably 8,000 or more.

[0204] Furthermore, the degree of dispersion (Mw / Mn) in the arylamine polymer 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 arylamine polymer is below the above upper limit, purification is easy, and solubility in solvents and charge transport capacity are good.

[0205] 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.

[0206] (Specific example) Specific examples of arylamine polymers are shown below, but the arylamine polymers in this embodiment are not limited to these. The numbers in the chemical formulas represent the molar ratio of repeating units, where n represents the number of repeating units.

[0207] These arylamine polymers may be random copolymers, alternating copolymers, block copolymers, or graft copolymers, and are not limited to the order of monomer arrangement.

[0208] [ka]

[0209] [ka]

[0210] [ka]

[0211] [ka]

[0212] Specific examples of arylamine polymers containing repeating units represented by formula (56) are shown below, but the arylamine polymers in this embodiment are not limited to these. The numbers in the chemical formulas represent the molar ratio of the repeating units, where n represents the number of repeating units.

[0213] These arylamine polymers may be random copolymers, alternating copolymers, block copolymers, or graft copolymers, and are not limited to the order of monomer arrangement.

[0214] [ka]

[0215] [ka]

[0216] (Method for manufacturing arylamine polymers) The method for producing the arylamine polymer contained in the first functional material is not particularly limited and is arbitrary. Examples include polymerization by the Suzuki reaction, polymerization by the Grignard reaction, polymerization by the Yamamoto reaction, polymerization by the Ullmann reaction, polymerization by the Buchwald-Hartwig reaction, and so on.

[0217] In the polymerization methods by the Ullmann reaction and the Buchwald-Hartwig reaction, for example, by reacting an aryl dihalide represented by formula (2a) with a primary aminoaryl represented by formula (2b), a polymer containing a repeating unit represented by formula (2), i.e., the repeating unit represented by formula (54), is synthesized.

[0218] [ka]

[0219] (In the above reaction equation, Z represents halogen atoms such as I, Br, Cl, and F. Also, Ar 1 , R 1 , R 2 , X, a~d are Ar in equation (54) above. 1 , R 1 , R 2 X, a-d, and d are all synonymous.

[0220] Furthermore, in the case of polymerization by the Ullmann reaction and polymerization by the Buchwald-Hartwig reaction, for example, by reacting an aryl dihalide represented by the following formula (3a) with a primary aminoaryl represented by the following formula (3b), a polymer containing a repeating unit represented by the following formula (3), i.e., the repeating unit represented by the above formula (55), is synthesized.

[0221] [ka]

[0222] (In the above reaction equation, Z represents halogen atoms such as I, Br, Cl, and F. Also, Ar 2 , R 3 ~R 6 l~n, p, q are Ar in equation (55) above. 2 , R 3 ~R 6 l~n, p, and q are all synonymous.

[0223] 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. It can also be carried out in the presence of a transition metal catalyst such as a copper or palladium complex.

[0224] (Arylamine polymer content) The content of the above-mentioned arylamine polymer in the first composition is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and also usually 70% by mass or less, preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 20% by mass or less. When the content of the arylamine polymer is within the above range, defects are less likely to occur in the formed first functional film, and uneven film thickness is less likely to occur, which is therefore preferable.

[0225] (solvent) The first composition typically contains a solvent. This solvent is preferably one that dissolves the arylamine polymer. Specifically, a solvent that dissolves the arylamine polymer in the first composition 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.

[0226] Specific examples of solvents include aromatic solvents such as toluene, xylene, mesitylene, cyclohexylbenzene, and methylnaphthalene; 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); and 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, and 3-methoxytoluene. Examples of organic solvents include ether-based solvents such as ene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole; aliphatic ester-based solvents such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; ester-based solvents such as aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, isopropyl benzoate, propyl benzoate, and n-butyl benzoate; and other organic solvents used in the hole injection layer formation compositions and hole transport layer formation compositions described later.

[0227] Furthermore, one type of solvent may be used, or two or more types may be used in any combination and ratio.

[0228] The surface tension of the solvent at 20°C is typically less than 40 dyn / cm, preferably 36 dyn / cm or less, and more preferably 33 dyn / cm or less. The lower limit of the surface tension is not particularly limited, but is typically 20 dyn / cm or more.

[0229] On the other hand, the vapor pressure of the solvent at 25°C is usually 10 mmHg or less, preferably 5 mmHg or less, and usually 0.1 mmHg or more. By using such a solvent, a first composition suitable for the properties of arylamine polymers can be prepared, which is suitable for the process of manufacturing organic semiconductor devices by wet film deposition.

[0230] Specific examples of such solvents include aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene, as well as ether solvents and ester solvents.

[0231] Incidentally, moisture can cause performance degradation of organic semiconductor devices, and in particular, it may accelerate the decrease in brightness during continuous operation when used as an organic electroluminescent device. Therefore, in order to reduce the amount of moisture remaining during wet film formation as much as possible, the solubility of water in the solvent at 25°C is preferably 1% by mass or less, more preferably 0.1% by mass or less, and the lower the amount, the better.

[0232] The solvent content in the first composition 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. A solvent content above the lower limit mentioned above ensures good flatness and uniformity of the formed layer. The upper limit of the solvent content is not particularly limited, but is usually 99.95% by mass or less.

[0233] <Second composition> The second composition is a composition that is applied onto the first functional film to form a second functional film. The second composition contains a solvent and has a viscosity of 15 mPa·s or less at 23°C. The solvent contains at least one first solvent component that satisfies a viscosity of 3 mPa·s or more at 23°C, or contains at least one first solvent component that satisfies a flow activation energy of 17 kJ / mol or more and at least one second solvent component that satisfies a viscosity of less than 3 mPa·s at 23°C.

[0234] Furthermore, the second composition may contain a second functional material that is different from the first functional material contained in the first composition. For example, if the organic semiconductor device is an organic electroluminescent device and the second functional film is an emissive layer, then the second functional material is usually a functional material such as an emissive material.

[0235] In one embodiment of the present invention, the viscosity of the first solvent component at 23°C is 3 mPa·s or higher, which prevents the dissolution of the first functional film. A viscosity of 4 mPa·s or higher is preferred, and 5 mPa·s or higher is more preferred. Furthermore, from the viewpoint of film flatness within the pixel, it is desirable that the viscosity of the first solvent component be 20 mPa·s or lower. In this embodiment, the solvent may contain only the first solvent component, or it may contain other solvent components.

[0236] The upper limit of the viscosity of the second composition varies depending on the application method. When applied by an inkjet device, the viscosity of the second composition at 23°C is preferably 15 mPa·s or less, more preferably 12 mPa·s or less, and even more preferably 10 mPa·s or less, from the viewpoint of facilitating ejection from the inkjet head. Furthermore, from the viewpoint of ejection stability, the viscosity of the second composition at 23°C is preferably 1 mPa·s or more, and even more preferably 2 mPa·s or more.

[0237] In this embodiment, the viscosity is measured using an E-type viscometer RE85L (manufactured by Toki Sangyo Co., Ltd.) at a temperature of 23°C with a cone plate rotation speed of 20 rpm to 100 rpm.

[0238] When applying the second composition over a large area, the immersion time is prolonged. During this time, the solvent gradually evaporates, lowering the temperature of the second composition and increasing its viscosity. If a solvent component with high viscosity temperature dependence (fluid activation energy) is used as the first solvent component, it is possible to use a solvent with a lower initial viscosity as the first solvent component and reduce the proportion of the first solvent in the second composition. In this way, lowering the initial viscosity of the solvent makes it possible to create a composition more suitable for ejection using the inkjet method. From this perspective, another embodiment of the present invention includes a first solvent component having a flow activation energy of 17 kJ / mol or more, and a second solvent component having a viscosity of less than 3 mPa·s. The flow activation energy of the first solvent component is 17 kJ / mol or more, more preferably 19 kJ / mol or more, and even more preferably 21 kJ / mol or more. There is no particular upper limit, but it is preferably 40 kJ / mol or less, more preferably 35 kJ / mol or less, even more preferably 32 kJ / mol or less, and particularly preferably 30 kJ / mol or less. A higher flow activation energy is preferable because it leads to a greater increase in viscosity due to the temperature drop when latent heat is removed by the volatilization of the solvent.

[0239] In yet another aspect of the present invention, the solvent comprises a first solvent component having a viscosity of 3 mPa·s or more at 23°C and a flow activation energy of 17 kJ / mol or more, and further comprises a second solvent component satisfying a viscosity of less than 3 mPa·s at 23°C. The preferred ranges for the viscosity and flow activation energy of the first solvent component at 23°C are as described above.

[0240] <Specific examples of the first solvent component> The first solvent component contained in the solvent of the second composition can be, for example, one of the compounds mentioned above that has a viscosity of 3 mPa·s or more at 23°C in the solvent of the first composition, such as isoamyl benzoate (3.36), 2-isopropylnaphthalene (3.45), fencone (3.47), decylbenzene (3.5), hexyl benzoate (4.08), 3-ethylbiphenyl (5.01), and 2-ethylhexyl benzoate (5.9). Examples include 2-phenoxyethyl isobutyrate (6.28), 4-isopropylbiphenyl (6.61), 4-methoxybenzoate ethyl (6.77), α-tetralone (7.2), tert-butylphenyl carbonate (7.24), 1-naphthaldehyde (7.24), 2-phenoxyethyl acetate (7.56), benzyl benzoate (8.45), diethyl phthalate (10.58), 1,1-diphenylpentane (10.8), and benzylphenyl carbonate (16.2). The numbers in parentheses after the above solvents indicate the viscosity (unit: mPa·s) at 23°C.

[0241] Furthermore, as the first solvent component contained in the solvent of the second composition, for example, any of the compounds mentioned above that have a fluid activation energy of 17 kJ / mol or more can be used as the solvent of the first composition. Examples include isoamyl benzoate (17.9), fencone (17.8), hexyl benzoate (19.5), 2-ethylhexyl benzoate (23.4), 4-isopropylbiphenyl (24.6), benzyl benzoate (24.5), 1,1-diphenylpentane (29.7), and benzylphenyl carbonate (32.6). The numbers in parentheses after the solvents listed above indicate the fluid activation energy (unit: kJ / mol). The fluid activation energy is E in equation (I) below. The fluid activation energy is determined by measuring the viscosity of the solvent at different temperatures, plotting the logarithm of viscosity against the reciprocal of temperature, and taking the slope of the plot. η = A exp(E / RT) (I) η: Viscosity (cP) A: Constant E: Fluid activation energy (kJ / mol) R: Gas constant (8.314 J / K / mol) T: Temperature (K) This can be determined by [method].

[0242] The second composition contains one or more first solvent components that satisfy a viscosity of 3 mPa·s or more and / or a flow activation energy of 17 kJ / mol or more at 23°C. This allows for industrially required insolubilization durability of 2 minutes or more, preferably 5 minutes or more, and more preferably 15 minutes or more, even if the arylamine polymer of the first functional film is not insolubilized by crosslinking groups, etc., and the thin film contains a first functional material with a small molecular weight that is calcined at a relatively low temperature and for a short time. This is thought to be because, due to heat treatment, rearrangement occurs at the surface and interface of the first functional film before the bulk, forming a relatively insoluble cover that suppresses solvent penetration and elution into the interior of the first functional film. The ease of penetration into the interior varies depending on the volume, shape, and internal degrees of freedom of the solvent molecules contained in the second composition. Furthermore, the stronger the intermolecular forces between solvent molecules, the more it hinders penetration and dispersion. The above-mentioned factors are more precisely determined by the relational equation (A) described later, but in a simplified manner, this can be achieved by using one or more first solvent components whose viscosity at 23°C is 3 mPa·s or higher.

[0243] From the viewpoint of ensuring the solubility of the second functional material, the first solvent component is preferably one having an aromatic hydrocarbon structure. Specifically, examples include solvent components having structures such as benzoic acid, biphenyl, and naphthalene.

[0244] The Hansen solubility parameter δP of the first solvent component is preferably δP < 10, and more preferably δP < 7. Due to the insolubilization characteristics of the first functional film, the durability time tends to be shortened with highly polar solvents, but a sufficient insolubilization durability time can be ensured by keeping δP within this range.

[0245] Furthermore, preferably, the theoretical surface area (Å) of the first solvent component calculated using the COSMO-RS solvation model. 2 ), volume (Å)3 The following relation (A) is satisfied for the ), boiling point (°C), and viscosity at 23°C (mPa·s). By satisfying the following relation (A) with respect to the first solvent component, longer-lasting insolubilization can be achieved. 32 × viscosity - 4.3 × theoretical surface area + 5.4 × volume - boiling point > 150···(A)

[0246] In the above relation (A), "viscosity" is the viscosity (mPa·s) of the first solvent component at 23°C. "Boiling point" is the boiling point of the first solvent component at atmospheric pressure. The "theoretical surface area" and "volume" of the first solvent component are values ​​calculated using the method described in A. Klamt, "COSMO-RS: From Quantum Chemistry to Fluid Phase Thermodynamics and Drug Design," Elsevier Science, 1st edition (September 29, 2005). Simply put, it is a value obtained by adding the volume obtained by stacking VDW spheres on the atoms of the structure-optimized molecule and its surface area (Cavity volume used in COSMO calculations). The coefficients in the above relation (A) are values ​​that were determined experimentally.

[0247] Viscosity indicates the force that holds solvent molecules together and correlates with the difficulty of penetration and dispersion into the first functional film. Furthermore, while a larger volume of solvent molecules makes penetration into the first functional film more difficult, a larger surface area for the same volume results in a shape that deviates from spherical and has a smaller cross-sectional area, i.e., a shape that facilitates penetration; therefore, a smaller surface area is preferable. Solvents with lower boiling points evaporate more easily, and the heat of vaporization lowers the temperature of the second composition, resulting in an increase in solvent viscosity. In addition, the vaporization of the solvent increases the concentration of solid materials in the second composition, thereby suppressing the solvent's effect on the underlying functional material film.

[0248] The value expressed on the left side of the above relation (A) is more preferably 160 or higher, and even more preferably 180 or higher, from the viewpoint of insolubilization. Furthermore, examples of the first solvent component that satisfies the above relation (A) include isoamyl benzoate (3.45), fencone (3.47), decylbenzene (3.5), hexyl benzoate (4.08), and benzoate. acid Examples include 2-ethylhexyl (5.9), 2-phenoxyethyl isobutyrate (6.28), 4-isopropylbiphenyl (6.61), 4-ethyl methoxybenzoate (6.77), tert-butylphenyl carbonate (7.24), 1-naphthaldehyde (7.24), 2-phenoxyethyl acetate (7.56), benzyl benzoate (8.45), 1,1-diphenylpentane (10.8), and benzylphenyl carbonate (16.2). The numbers in parentheses after the above solvents indicate the viscosity at 23°C.

[0249] <Other solvent components / composition> The second composition may contain other solvents besides the first solvent component. The second solvent component may have a lower viscosity than the first solvent component. That is, the second solvent component is a solvent with a viscosity of less than 3 mPa·s at 23°C. Specifically, examples include those listed as solvents included in the first composition that have a viscosity of less than 3 mPa·s at 23°C. The second solvent component is preferably included if the fluid activation energy of the first solvent component is 17 kJ / mol or higher.

[0250] The fluid activation energy of the second solvent component is preferably 10 kJ / mol or more, more preferably 12 kJ / mol or more, and even more preferably 14 kJ / mol or more. There is no particular upper limit, but it is preferably 18 kJ / mol or less, more preferably 17 kJ / mol or less, even more preferably 16 kJ / mol or less, and especially even more preferably 15 kJ / mol or less.

[0251] When applying using an inkjet device, it is desirable to include a low-viscosity second solvent component to lower the overall viscosity of the second composition, from the viewpoint of proper ejection from the inkjet head. In particular, from the viewpoint of avoiding drying during the process of applying the second composition to form the second functional film, it is preferable that the boiling point of the second solvent component be 180°C or higher. Examples of such second solvent components include ethyl benzoate, tetralin, 2-ethylnaphthalene, ethyl toluate, cyclohexylbenzene, and butyl benzoate.

[0252] From the viewpoint of ensuring insolubilization time, the first solvent component is preferably present in the second composition in a total amount of 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more. There is no particular upper limit to the total content of the first solvent component, but it is usually 99% by mass or less. Furthermore, considering the normal solid content concentration, the total content of the first solvent component is preferably 95% by mass or less, and if a second solvent component is present, the total content of the first solvent component is preferably 90% by mass or less. Moreover, from the viewpoint of solvent evaporability, the total content of the first solvent component is preferably 70% by mass or less, and more preferably 50% by mass or less.

[0253] When the solvent of the second composition is a mixed solvent containing the first solvent component plus the second solvent component, the ratio of the first solvent component to the total of the first and second solvent components is preferably 10% or more by mass, and more preferably 15% or more. This is because, considering the order of evaporation of the mixed solvent, it is desirable that a certain amount of the first solvent component remains until the second solvent component, which does not correspond to the first solvent component, evaporates.

[0254] The proportion of the second solvent component to the sum of the first and second solvent components is preferably 30% by mass or more. A proportion of 30% by mass or more allows the temperature of the first solvent to be appropriately lowered by the evaporation of the second solvent component, thereby increasing the viscosity of the first solvent component. The proportion of the second solvent component is more preferably 50% by mass or more, and most preferably 70% by mass or more. From the viewpoint of the flatness of the functional film, the proportion of the second solvent component is preferably 90% by mass or less, and from the viewpoint of leaving a certain amount of the first solvent component before the second solvent component evaporates, the proportion of the second solvent component is more preferably 85% by mass or less. Furthermore, from the viewpoint of evaporating the second solvent component earlier than the first solvent component, the boiling point of the second solvent component is preferably lower than that of the first solvent component, preferably 280°C or lower, and more preferably 250°C or lower. On the other hand, from the viewpoint of drying control in large-area coating, the boiling point of the second solvent component is preferably 180°C or higher, and more preferably 200°C or higher.

[0255] As mentioned above, from the viewpoint of not dissolving the lower layer, the first functional layer, it is preferable that the second composition has a first solvent component with a viscosity of 3 mPa·s or more at 23°C. On the other hand, from the viewpoint of ejection performance in inkjet coating, it is preferable that the viscosity of the composition is low (viscosity of 15 mPa·s or less at 23°C). From the viewpoint of reducing the overall viscosity of the second composition, it is preferable that the second composition has a second solvent component with a viscosity of less than 3 mPa·s at 23°C. Furthermore, the second solvent component is preferably included if the fluid activation energy of the first solvent component is 17 kJ / mol or higher. Having a fluid activation energy of 17 kJ / mol or higher makes it easier to achieve both the inkjet ejection performance and the insolubility of the underlying layer. The second solvent component is a low-viscosity solvent (viscosity less than 3 mPa·s at 23°C) and tends to volatilize before the first solvent component. In doing so, it absorbs heat of vaporization, lowering the temperature of the second composition. The high fluid activation energy of the first solvent component increases the viscosity of the remaining second composition, making it difficult for it to penetrate the underlying first functional layer, which is preferable from the viewpoint of insolubilization.

[0256] The second composition may contain a second functional material different from the first functional material. When the organic semiconductor device is an organic electroluminescent element and the second functional film is a hole transport layer, the second functional material can be, for example, a hole transport material. ,The hole transport material may include, for example, an arylamine polymer of formula (50) similar to that of the first functional membrane, or one of the hole transport materials described later may be used.

[0257] When the organic semiconductor element is an organic electroluminescent element and the second functional film is a light-emitting layer, the second functional material can be a light-emitting material such as a phosphorescent material described later, or a charge transport material. It is also preferable to include a low molecular weight aromatic compound as the second functional material. When the second functional material is low molecular weight, the viscosity of the second composition can be lower than when it is high molecular weight. When a high viscosity solvent is used as the first solvent component, or when the first solvent component is used in a high composition ratio, the viscosity of the entire second composition tends to increase, but this is more acceptable if the second functional material is low molecular weight.

[0258] As low molecular weight aromatic compounds, for example, those described later can be used as charge transport materials for the light-emitting layer. The molecular weight of the low molecular weight aromatic compound is preferably less than 5000, more preferably 4000 or less, even more preferably 3000 or less, and particularly preferably less than 2000.

[0259] The second composition in this embodiment may contain only one second functional material, or it may contain two or more second functional materials.

[0260] (Solvent and functional material content) There are no particular restrictions on the content of the first functional material and the second functional material in the first composition and the second composition in this embodiment, but each is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, more preferably 1.0% by weight or more, preferably 20% by weight or less, more preferably 15% by weight or less, and more preferably 10% by weight or less.

[0261] <Film formation by wet deposition method> The method for manufacturing an organic semiconductor device according to this embodiment includes the steps of applying and heating a first composition to provide a first functional film, and applying a second composition on the first functional film to provide a second functional film. These processes include, but are not limited to, the following examples i) or ii) where, if the organic semiconductor device is an organic electroluminescent device, the first functional film is a hole injection layer and the second functional film is a hole transport layer, or the first functional film is a hole transport layer and the second functional film is a light-emitting layer.

[0262] i) A step of applying and heating a first composition onto the anode to provide a hole injection layer as a first functional film, and a step of applying a second composition on the hole injection layer to provide a hole transport layer as a second functional film. ii) A step of applying and heating a first composition onto a hole injection layer to provide a hole transport layer as a first functional film, and a step of applying a second composition onto the hole transport layer to provide a light-emitting layer as a second functional film.

[0263] In this embodiment, when the organic semiconductor element is an organic electroluminescent element, it typically has a substrate on which electrodes are provided, with a micro-region partitioned by partitions called banks where light-emitting pixels are located. The first composition of this embodiment is applied to this micro-region partitioned by banks by dispensing, dried, and then appropriately heated to form the first functional film.

[0264] The ejection method involves ejecting droplets smaller than the micro-regions partitioned by the bank from a minute nozzle, and it is preferable to fill the micro-regions partitioned by the bank with the first composition by ejecting multiple droplets. The ejection method is preferably an inkjet method.

[0265] In the wet film deposition method, a small area partitioned by a bank is filled with the first composition, and then vacuum-dried. Vacuum drying is the process of volatilizing the solvent by reducing the pressure.

[0266] While most of the solvent can be evaporated by vacuum drying, it is preferable to perform subsequent heat drying to ensure thorough drying. The heating temperature and duration should preferably be such that the first functional film does not crystallize or aggregate.

[0267] When the first composition contains a functional material that is a low molecular weight material, the heating temperature is usually 50°C or higher, preferably 80°C or higher, more preferably 100°C or higher, more preferably 120°C or higher, and usually 200°C or lower, preferably 180°C or lower, more preferably 150°C or lower. The heating time is usually 1 minute or more, preferably 3 minutes or more, more preferably 5 minutes or more, and usually 120 minutes or less, preferably 90 minutes or less, more preferably 60 minutes or less.

[0268] Since the first functional material contains an arylamine polymer, which is a polymer material, the heating temperature is usually 80°C or higher, preferably 100°C or higher, more preferably 150°C or higher, and more preferably 200°C or higher, and usually 300°C or lower, preferably 270°C or lower, and more preferably 240°C or lower. The heating time is usually 1 minute or more, preferably 3 minutes or more, more preferably 5 minutes or more, and usually 120 minutes or less, preferably 90 minutes or less, and more preferably 60 minutes or less.

[0269] Within the range where solvent removal and the required insolubilization endurance time are achieved, the heating temperature in the step of forming the first functional film is preferably lower, and may be carried out at a temperature lower than the glass transition temperature of the arylamine polymer.

[0270] Heating can be carried out using a hot plate, oven, infrared irradiation, etc. In the case of infrared irradiation, which directly applies molecular vibrations, a heating time close to the lower limit above is sufficient. In the case of hot plate heating, where the substrate is in direct contact with the heat source or the heat source and substrate are placed very close together, a longer time is required than with infrared irradiation. In the case of oven heating, that is, heating with a gas inside the oven, usually air or an inert gas such as nitrogen or argon, it takes time for the temperature to rise, so a heating time close to the upper limit above is preferable. The heating time is adjusted as appropriate depending on the heating method.

[0271] A second functional film is formed by applying a second composition onto a first functional film formed in the bank by coating and heating. Similar to the first composition, an inkjet method is preferred for coating.

[0272] In this embodiment, the second composition to be applied contains at least one first solvent component that satisfies a viscosity of 3 mPa·s or more and / or a flow activation energy of 17 kJ / mol or more at 23°C, so that it does not dissolve the first functional film for longer than the time required industrially. Here, industrially, the process of forming a film on a large substrate using a coating method, particularly an inkjet method, is assumed to require at least 2 minutes from the time the second composition is applied to the first functional film until the solvent contained in the second composition evaporates, that is, immersion for at least 2 minutes. Here, immersion means that the second composition is in contact with the entire or partial surface of the first functional film in a liquid state. Therefore, it is preferable that the first functional film does not dissolve after immersion for at least 2 minutes, more preferably 5 minutes, even more preferably 10 minutes, and even more preferably 15 minutes or more. The atmospheric pressure and temperature at this time are assumed to be 1 Pa or higher and 50°C or lower, respectively.

[0273] Here, "until the solvent evaporates" means until the entire solvent contained in the second composition has evaporated. That is, if the solvent contained in the second composition is only the first solvent component, it means until the first solvent component has evaporated. If the solvent contained in the second composition is both the first and second solvent components, it means until all of them have evaporated. Furthermore, for a solvent to evaporate completely, the amount of residual solvent does not need to be exactly zero. Depending on the boiling point of the solvent, some residual solvent may remain. Therefore, if the volume-based concentration in the second functional film is 100 ppm or less, it can be considered that the solvent has evaporated completely.

[0274] Furthermore, the first functional film does not need to be insolubilized at all positions in its cross-sectional direction. Even with polymer materials that do not form chemical bonds through crosslinking groups, when an arylamine polymer with an appropriate molecular structure and molecular weight is subjected to thermal treatment, the surface and interface rearrange prior to the bulk portion, forming a surface that is less susceptible to elution by the solvent used during the upper layer coating. At this time, most of the thin film remains in an amorphous state, and dissolves rapidly after the surface elution.

[0275] The first functional film can utilize low molecular weight functional materials that offer advantages in terms of lower temperature and shorter heat treatment times, as well as greater flexibility in film thickness design, all within the range where this insolubility can be achieved.

[0276] In the insolubilized state described above, the influence of the second composition on the endurance time until the dissolution of the first functional film begins varies depending on the solvent molecules contained in the second composition, particularly the volume, surface area, internal degrees of freedom, and intermolecular forces between solvent molecules of the first solvent component. There is little correlation with the Hansen solubility parameter δP of the solvent molecules, but solvent molecules with a δP above a certain level tend to shorten the endurance time and should be avoided. The inventors experimentally elucidated the criteria for selecting a preferred solvent molecule and established a determination formula. This is the aforementioned relational formula (A) below. 32 × viscosity - 4.3 × theoretical surface area + 5.4 × volume - boiling point > 150···(A) Furthermore, this determination can be made in a simplified manner by roughly determining the viscosity of the solvent.

[0277] Furthermore, when applying the second composition onto the first functional film, assuming that an inkjet device is used, the second composition as a whole must have a viscosity suitable for ejection, i.e., a viscosity of 15 mPa·s or less. However, depending on the application method, a viscosity of 15 mPa·s or less is not mandatory.

[0278] [First functional membrane and second functional membrane] The content of the first functional material or the second functional material contained in the first functional film or the second functional film is usually 70% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more, particularly preferably 95% by weight or more, and most preferably substantially 100% by weight, with an upper limit of 100% by weight. Substantially 100% by weight means that the functional film may contain trace amounts of additives, residual solvents, and impurities. By having the content of the functional material in the functional film within this range, the function of the functional material can be expressed more effectively.

[0279] [Layer structure and formation method of organic electroluminescent devices] A preferred example of an embodiment of the layer configuration and method of forming the organic semiconductor element manufactured using the first and second compositions in this embodiment, when the organic semiconductor element is an organic electroluminescent element (hereinafter sometimes referred to as "organic electroluminescent element in this embodiment"), will be described with reference to Figure 1.

[0280] Figure 1 is a schematic cross-sectional view showing an example of the structure of the organic electroluminescent element 10 in this embodiment. 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.

[0281] In this embodiment, the organic electroluminescent device has an anode 2, a light-emitting layer 5, and a cathode 9 as essential constituent layers, but if necessary, other functional layers may be included between the anode 2 and the light-emitting layer 5 and between the cathode 9 and the light-emitting layer 5, as shown in Figure 1.

[0282] [substrate] Substrate 1 serves as a support for the organic electroluminescent device. Substrate 1 can be a plate of quartz or glass, a metal plate or metal foil, a plastic film or sheet, etc. Glass plates are particularly preferred; transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, or polysulfone are also preferred.

[0283] When using a synthetic resin substrate, it is preferable to pay attention to its gas barrier properties. A high gas barrier property of the substrate is preferable because it reduces the likelihood of degradation of the organic electroluminescent element due to outside air passing through the substrate. For this reason, one preferred method is to ensure gas barrier properties by providing a dense silicon oxide film or the like on at least one side of the synthetic resin substrate.

[0284] [anode] Anode 2 is an electrode that plays the role of injecting holes into the layer on the light-emitting layer 5 side. The 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; or conductive polymers such as poly(3-methylthiophene), polypyrrole, and polyaniline.

[0285] The formation of anode 2 is usually carried out by methods such as sputtering or vacuum deposition. When forming anode 2 using metal nanoparticles such as silver, nanoparticles such as copper iodide, carbon black, conductive metal oxide nanoparticles, conductive polymer fine powder, etc., the anode 2 can also be formed by dispersing these nanoparticles in a suitable binder resin solution and coating it onto substrate 1. In the case of conductive polymers, a thin film can also be formed directly on the substrate 1 by electrolytic polymerization. Alternatively, a conductive polymer can be coated onto substrate 1 to form anode 2 (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0286] Anode 2 is usually a single-layer structure, but it can also be a multilayer structure consisting of multiple materials if desired.

[0287] The thickness of anode 2 can be selected as appropriate depending on the required transparency and other factors. When transparency is required, it is preferable to have a visible light transmittance of 60% or more, preferably 80% or more. In this case, the thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably around 500 nm or less. If opacity is acceptable, the thickness of anode 2 is arbitrary. A substrate 1 that also functions as anode 2 may be used. It is also possible to laminate different conductive materials on top of the above anode 2.

[0288] To remove impurities attached to anode 2 and adjust the ionization potential to improve hole injection performance, it is also preferable to treat the surface of anode 2 with ultraviolet (UV) / ozone, or with oxygen plasma or argon plasma.

[0289] [Hole injection layer] The hole injection layer 3 is the layer into which holes flow from the electrode when transporting holes from the anode 2 to the light-emitting layer 5. When the hole injection layer 3 is provided, it is usually formed on the anode 2.

[0290] The method for forming the hole injection layer 3 can be either vacuum deposition or wet deposition, and there are no particular restrictions. However, from the viewpoint of reducing dark spots, it is preferable to form the hole injection layer 3 by wet deposition. The thickness of the hole injection layer 3 is typically 5 nm or more, preferably 10 nm or more, and typically 1000 nm or less, preferably 500 nm or less.

[0291] (Hole transport material) Compositions for forming hole injection layers typically contain a hole transport material and a solvent as constituent materials of the hole injection layer 3.

[0292] The hole transport material is typically used in the hole injection layer 3 of an organic electroluminescent device. Any compound with hole transport properties may be a polymer or other high-molecular-weight compound, or a monomer or other low-molecular-weight compound, but a polymer is preferred.

[0293] As hole transport materials, compounds having an ionization potential of 4.5 eV to 6.0 eV are preferred from the viewpoint of a charge injection barrier from anode 2 to hole injection layer 3. Examples of hole transport materials include aromatic amine derivatives, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, benzylphenyl derivatives, compounds in which tertiary amines are linked by fluorene groups, hydrazone derivatives, silazane derivatives, silanamin derivatives, phosphatamine derivatives, quinacridone derivatives, polyaniline derivatives, polypyrrole derivatives, polyphenylene vinylene derivatives, polythienylene vinylene derivatives, polyquinoline derivatives, polyquinoxaline derivatives, carbon, and the like.

[0294] In this specification, derivatives include, for example, aromatic amine derivatives, the aromatic amine itself and compounds having an aromatic amine as the main skeleton, and may be polymers or monomers.

[0295] The hole transport material used as the material for the hole injection layer 3 may contain one of these compounds alone, or two or more of them. When two or more hole transport materials are included, the combination is arbitrary, but it is preferable to use one or more aromatic tertiary amine polymer compounds in combination with one or more other hole transport materials.

[0296] As hole transport materials, aromatic amine compounds are preferred among those exemplified above in terms of amorphous nature and visible light transmittance, and aromatic tertiary amine compounds are particularly preferred. Aromatic tertiary amine compounds are compounds having an aromatic tertiary amine structure, and also include compounds having groups derived from aromatic tertiary amines.

[0297] The type of aromatic tertiary amine compound is not particularly limited, but polymer compounds (polymerized compounds with repeating units) with a weight-average molecular weight of 1,000 or more and 1,000,000 or less are more preferred from the viewpoint of uniform luminescence due to the surface smoothing effect. Preferred examples of aromatic tertiary amine polymer compounds include polymer compounds having repeating units represented by the following formula (1) or formula (11).

[0298] [ka]

[0299] (In formula (1), Ar 3 This represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have substituents, and Ar 4 (This represents a divalent group formed by linking one or more groups selected from at least one of a divalent aromatic hydrocarbon group and a divalent aromatic heterocyclic group, which may have substituents, and the linking is made directly or via linking groups.)

[0300] In formula (1) above, when an aromatic hydrocarbon group and an aromatic heterocyclic group are linked together via a linking group, the linking group is a divalent linking group, and examples include a group formed by linking 1 to 30 groups, preferably 1 to 5, and more preferably 1 to 3, selected from -O- groups, -C(=O)- groups, and (may have substituents) -CH2- groups in any order.

[0301] Among the linking groups, Ar in formula (1) is superior in that it is excellent at hole injection into the light-emitting layer. 4 However, it is preferable that the aromatic hydrocarbon group or aromatic heterocyclic group is linked together via a linking group represented by the following formula (2).

[0302] [ka]

[0303] (In formula (2), d represents an integer between 1 and 10. R 8 and R 9 Each of these independently represents an alkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, which may have a hydrogen atom or a substituent. R 8 , R 9 If multiple instances exist, they may be the same or different.

[0304] [ka]

[0305] (In equation (11) above, j, k, l', m', n', and p' each independently represent a non-negative integer, provided that l'+m'≧1. 11 Ar 12 Ar 14 Each of these independently represents a divalent aromatic ring group having 30 or fewer carbon atoms, which may have substituents. 13 Q represents a divalent aromatic ring group having 30 or fewer carbon atoms, which may have substituents, or a divalent group represented by the following formula (12), 11 Q 12 Each of these independently represents an oxygen atom, a sulfur atom, or a hydrocarbon chain having 6 or fewer carbon atoms, which may have substituents. 1 ~S 4 Each of these is independently represented by the group shown in formula (13) below. (Note that, in this context, an aromatic ring group refers to at least one of an aromatic hydrocarbon ring group and an aromatic heterocyclic ring group.)

[0306] Ar 11 Ar 12 Ar 14Examples of aromatic ring groups include monocyclic rings, 2-6 fused rings, or groups in which two or more of these aromatic rings are linked together. Specific examples of monocyclic or 2-6 fused aromatic ring groups include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluorantene ring, fluorene ring, biphenyl group, terphenyl group, quaterphenyl group, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, and pyrazole ring. Examples of divalent groups derived from roloimidazole rings, pyrrolopyrazole rings, pyrrolopyrrole rings, thienopyrrole rings, thienohyphene 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, cinoline rings, quinoxaline rings, phenanthridine rings, perimidine rings, quinazoline rings, quinazolinone rings, or azulene rings. Among these, divalent groups derived from benzene rings, naphthalene rings, fluorene rings, pyridine rings, or carbazole rings, or biphenyl groups, are preferred because they efficiently delocalize negative charges and have excellent stability and heat resistance. Ar 13 Examples of aromatic ring groups include Ar 11 Ar 12 Ar 14 This is the same as in the previous case.

[0307] [ka]

[0308] (In the above formula (12), R 11 R represents an alkyl group, an aromatic ring group, or a trivalent group consisting of an alkyl group having 40 or fewer carbon atoms and an aromatic ring group, and these may have substituents. 12 represents an alkyl group, an aromatic ring group, or a divalent group consisting of an alkyl group with 40 or fewer carbon atoms and an aromatic ring group, which may have substituents.31 represents a monovalent aromatic ring group or a monovalent bridging group, and these groups may have substituents. q' represents an integer from 1 to 4. If q' is 2 or greater, multiple R 12 They may be the same or different, and multiple Ar 31 These may be the same or different. An asterisk (*) indicates a bond with the nitrogen atom in equation (11).

[0309] R 11 The aromatic ring group is preferably a single aromatic ring group having 3 to 30 carbon atoms, either a monocyclic or fused ring, or a group in which 2 to 6 such rings are linked together. Specific examples include trivalent groups derived from benzene rings, fluorene rings, naphthalene rings, carbazole rings, dibenzofuran rings, dibenzothiophene rings, and groups in which 2 to 6 of these rings are linked together. R 11 The alkyl group is preferably a linear, branched, or ring-containing alkyl group having 1 to 12 carbon atoms. Specific examples include groups derived from methane, ethane, propane, isopropane, butane, isobutane, pentane, hexane, and octane. R 11 Preferably, the group consisting of an alkyl group having 40 or fewer carbon atoms and an aromatic ring group is a group in which a linear, branched, or ring-containing alkyl group having 1 to 12 carbon atoms is linked to one or two to six aromatic ring groups that are monocyclic or fused rings having 3 to 30 carbon atoms.

[0310] R 12 Specific examples of aromatic ring groups include benzene rings, fluorene rings, naphthalene rings, carbazole rings, dibenzofuran rings, dibenzothiophene rings, and divalent groups derived from linked rings with 30 or fewer carbon atoms. R 12 Specific examples of alkyl groups include divalent groups derived from methane, ethane, propane, isopropane, butane, isobutane, pentane, hexane, and octane.

[0311] Ar 31Specific examples of aromatic ring groups include benzene rings, fluorene rings, naphthalene rings, carbazole rings, dibenzofuran rings, dibenzothiophene rings, and monovalent groups derived from linked rings with 30 or fewer carbon atoms.

[0312] Examples of preferred structures of formula (12) include the following structure, R 11 In the following substructure, the benzene ring or fluorene ring in the main chain may have further substituents.

[0313] [ka]

[0314] Ar 31 Examples of crosslinking groups include groups derived from benzocyclobutene rings, naphthocyclobutene rings, or oxetane rings, vinyl groups, acrylic groups, etc. Due to the stability of the compound, groups derived from benzocyclobutene rings or naphthocyclobutene rings are preferred.

[0315] [ka]

[0316] (In equation (13) above, x and y each represent an independent integer of 0 or greater. 21 Ar 23 Each of these independently represents a divalent aromatic ring group, and these groups may have substituents. 22 R represents a monovalent aromatic ring group which may have substituents, 13 represents an alkyl group, an aromatic ring group, or a divalent group consisting of an alkyl group and an aromatic ring group, which may have substituents. 32 represents a monovalent aromatic ring group or a monovalent bridging group, which may have substituents. An asterisk (*) indicates a bond with the nitrogen atom in formula (11).

[0317] Ar 21 Ar 23 Examples of aromatic ring groups include Ar11 Ar 12 Ar 14 This is the same as in the previous case.

[0318] Ar 22 Ar 32 Examples of aromatic ring groups include monocyclic rings, 2-6 fused rings, or groups in which two or more of these aromatic rings are linked. Specific examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, fluorene rings, biphenyl groups, terphenyl groups, quaterphenyl groups, furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, and pyrroloimidazole. Examples of monovalent groups derived from rings, pyrrolopyrazole rings, pyrrolopyrrole rings, thienopyrrole rings, thienothiophene 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, cinoline rings, quinoxaline rings, phenanthridine rings, perimidine rings, quinazoline rings, quinazolinone rings, or azulene rings. Among these, monovalent groups derived from benzene rings, naphthalene rings, fluorene rings, pyridine rings, or carbazole rings, or biphenyl groups, are preferred because they efficiently delocalize negative charges and have excellent stability and heat resistance.

[0319] R 13 Examples of alkyl groups or aromatic ring groups include R 12 It is similar to that.

[0320] Ar 32 The crosslinking group is not particularly limited, but preferred examples include groups derived from benzocyclobutene rings, naphthocyclobutene rings or oxetane rings, vinyl groups, acrylic groups, and the like.

[0321] The above Ar 11 ~Ar 14 , R11 ~R 13 Ar 21 ~Ar 23 Ar 31 ~Ar 32 Q 11 Q 12 Each of these may have further substituents, as long as it does not contradict the spirit of the present invention. The molecular weight of the substituent is preferably 400 or less, and more preferably 250 or less. The type of substituent is not particularly limited, but examples include one or more types selected from the substituent group W below.

[0322] [Substituent group W] Alkyl groups having 1 or more carbon atoms, preferably 10 or less, and more preferably 8 or less, such as methyl and ethyl groups; alkenyl groups having 2 or more carbon atoms, preferably 11 or less, and more preferably 5 or less, such as vinyl groups; alkynyl groups having 2 or more carbon atoms, preferably 11 or less, and more preferably 5 or less, such as ethynyl groups; alkoxy groups having 1 or more carbon atoms, preferably 10 or less, and more preferably 6 or less, such as methoxy and ethoxy groups; phenoxy, naphthoxy, pyridyloxy groups, etc. having 4 or more carbon atoms, preferably 5 or more, preferably 25 or less, and more preferably 14 or fewer aryloxy groups; methoxycarbonyl groups, ethoxycarbonyl groups, etc., with 2 or more carbon atoms, preferably 11 or fewer, more preferably 7 or fewer; dialkylamino groups, etc., with 2 or more carbon atoms, preferably 20 or fewer, more preferably 12 or fewer; diarylamino groups, etc., with 10 or more carbon atoms, preferably 12 or more, preferably 30 or fewer, more preferably 22 or fewer; phenylmethylamino groups, etc., with 6 or more carbon atoms. , more preferably 7 or more, preferably 25 or less, and more preferably 17 or less arylalkylamino groups; acetyl groups, benzoyl groups, etc., with 2 or more carbon atoms, preferably 10 or less, and more preferably 7 or less acyl groups; halogen atoms such as fluorine atoms and chlorine atoms; haloalkyl groups such as trifluoromethyl groups, with 1 or more carbon atoms, preferably 8 or less, and more preferably 4 or less haloalkyl groups; methylthio groups, ethylthio groups, etc., with 1 or more carbon atoms, preferably 10 or less, and more preferably 6 or less alkylthio groups; phenylthio groups, naphthylthio groups, pyridylthio groups, etc. arylthio groups having 4 or more carbon atoms, preferably 5 or more, preferably 25 or less, and more preferably 14 or less; silyl groups having 2 or more carbon atoms, preferably 3 or more, preferably 33 or less, and more preferably 26 or less, such as trimethylsilyl group and triphenylsilyl group; siloxy groups having 2 or more carbon atoms, preferably 3 or more, preferably 33 or less, and more preferably 26 or less, such as trimethylsiloxy group and triphenylsiloxy group; cyano groups; aromatic hydrocarbon groups having 6 or more carbon atoms, preferably 30 or less, and more preferably 18 or less, such as phenyl group and naphthyl group;Aromatic heterocyclic groups such as thienyl groups and pyridyl groups, having 3 or more carbon atoms, preferably 4 or more, preferably 28 or fewer, and more preferably 17 or fewer.

[0323] Of the substituent group W described above, alkyl groups or alkoxy groups are preferred from the viewpoint of improving solubility, and aromatic hydrocarbon groups or aromatic heterocyclic groups are preferred from the viewpoint of charge transport and stability.

[0324] In particular, among polymer compounds having repeating units represented by formula (11), polymer compounds having repeating units represented by formula (14) below are preferred because they exhibit very high hole injection and transport properties.

[0325] [ka]

[0326] (In the above formula (14), R 21 ~R 25 Each of these independently represents an arbitrary substituent. 21 ~R 25 Specific examples of substituents are the same as those listed in [substituent group W] above. s and t each independently represent integers between 0 and 5, inclusive. u, v, and w each independently represent integers between 0 and 4 (inclusive).

[0327] Preferred examples of aromatic tertiary amine polymer compounds include polymer compounds containing repeating units represented by the following formulas (15) and / or (16).

[0328] [ka]

[0329] (In equations (15) and (16) above, Ar 45 Ar 47 and Ar 48Each of these independently represents a potentially substituted monovalent aromatic hydrocarbon group or a potentially substituted monovalent aromatic heterocyclic group. 44 and Ar 46 Each of these independently represents a optionally substituted divalent aromatic hydrocarbon group or an optionally substituted divalent aromatic heterocyclic group. 41 ~R 43 Each of these independently represents a hydrogen atom or any substituent.

[0330] Ar 45 Ar 47 and Ar 48 Examples of specific examples, preferred examples, examples of optional substituents, and examples of preferred substituents are given by Ar 22 It is similar to Ar 44 and Ar 46 Examples of specific examples, preferred examples, examples of optional substituents, and examples of preferred substituents are given by Ar 11 Ar 12 and Ar 14 It is similar to R. 41 ~R 43 Preferably, the substituent is a hydrogen atom or one of the substituents listed in [substituent group W] above, and more preferably, it is a hydrogen atom, an alkyl group, an alkoxy group, an amino group, an aromatic hydrocarbon group, or an aromatic heterocyclic group.

[0331] The following are some preferred examples of repeating units represented by formulas (15) and (16) that are applicable to this embodiment, but the present invention is not limited to these.

[0332] [ka]

[0333] (Electron-accepting compounds) The hole injection layer forming composition preferably contains an electron-accepting compound as a constituent material of the hole injection layer 3.

[0334] Electron-accepting compounds are preferably compounds that possess oxidizing power and the ability to accept one electron from the hole transport material mentioned above. Specifically, electron-accepting compounds are preferably those with an electron affinity of 4.0 eV or higher, and more preferably those with an electron affinity of 5.0 eV or higher.

[0335] 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. More specifically, examples of electron-accepting compounds 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 and aromatic boron compounds such as tris(pentafluorophenyl)borane (Japanese Patent Publication No. 2003-31365); fullerene derivatives; iodine; and sulfonate ions such as polystyrene sulfonate ions, alkylbenzene sulfonate ions, and camphor sulfonate ions.

[0336] The electron-accepting compound can improve the conductivity of the hole injection layer 3 by oxidizing the hole transport material.

[0337] (Other constituent materials) As long as the effects of the present invention are not significantly impaired, the material of the hole injection layer 3 may also contain other components in addition to the hole transport material and electron-accepting compound described above.

[0338] (solvent) It is preferable that at least one of the solvents in the hole injection layer formation composition used in the wet film deposition method is a compound capable of dissolving the constituent materials of the hole injection layer 3 described above.

[0339] If the hole injection layer forming composition is the second composition in this embodiment, the solvent is the first solvent component or the second solvent component in this embodiment.

[0340] Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

[0341] 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.

[0342] Examples of ester solvents include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

[0343] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene.

[0344] Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide. Other substances such as dimethyl sulfoxide can also be used. Among these, aromatic esters and aromatic ethers are particularly preferred.

[0345] These solvents may be used individually, or two or more may be used in any combination and ratio.

[0346] The concentration of the hole transport material in the hole injection layer forming composition is arbitrary, as long as it does not significantly impair the effects of the present invention. The concentration of the hole transport material in the hole injection layer forming composition is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and even more preferably 0.5% by weight or more, from the viewpoint of uniformity of film thickness. The concentration of the hole transport material in the hole injection layer forming composition is preferably 70% by weight or less, more preferably 60% by weight or less, and even more preferably 50% by weight or less. A low concentration is preferable in that it is less likely to cause unevenness in film thickness. A high concentration is preferable in that it is less likely to cause defects in the formed hole injection layer.

[0347] (Formation of hole injection layer by wet deposition method) When forming a hole injection layer 3 by a wet deposition method, a composition for film formation (composition for forming the hole injection layer) is usually prepared by mixing the materials constituting the hole injection layer 3 with a suitable solvent (solvent for the hole injection layer). This composition for forming the hole injection layer 3 is then applied to the layer corresponding to the layer below the hole injection layer (usually the anode 2) using an appropriate method, deposited, and dried to form the hole injection layer 3.

[0348] (Formation of hole injection layer 3 by vacuum deposition method) When forming the hole injection layer 3 by vacuum deposition, the hole injection layer 3 can be formed, for example, as follows. One or more of the constituent materials of the hole injection layer 3 (such as the aforementioned hole transport material and electron acceptor compound) are placed in crucibles set up inside the vacuum chamber (if more than two materials are used, each is placed in its own crucible), and the inside of the vacuum chamber is vacuumed with a suitable vacuum pump for 10°C. -4 The air is evacuated to approximately Pa. After this, the crucible is heated (each crucible is heated if two or more materials are used), and the evaporation rate is controlled to evaporate the material (each material is evaporated independently if two or more materials are used) to form a hole injection layer 3 on the anode 2 of the substrate 1, which is placed facing the crucible. If two or more materials are used, a mixture of these materials can also be placed in the crucible, heated, and evaporated to form the hole injection layer 3.

[0349] The vacuum level during deposition is not limited as long as it does not significantly impair the effects of the present invention. The vacuum level during vapor deposition is typically 0.1 × 10⁻⁶. -6 Torr(0.13×10 -4 Pa) or more, 9.0×10 -6 Torr(12.0× 10 -4 Pa) is less than or equal to [amount]. The deposition rate is not limited as long as it does not significantly impair the effects of the present invention. The deposition rate is typically between 0.1 Å / second and 5.0 Å / second. The film deposition temperature during vapor deposition is not limited as long as it does not significantly impair the effects of the present invention. The film deposition temperature during vapor deposition is preferably 10°C or higher and 50°C or lower.

[0350] [Hole transport layer] The hole transport layer 4 is a layer that transports holes from the anode 2 to the light-emitting layer 5. Typically, the hole transport layer 4 is formed on top of the hole injection layer 3 if one is present, and on top of the anode 2 if the hole injection layer 3 is not present.

[0351] The method for forming the hole transport layer 4 can be either vacuum deposition or wet deposition, and there are no particular restrictions. However, from the viewpoint of reducing dark spots, it is preferable to form the hole transport layer 4 by wet deposition.

[0352] The hole transport layer 4 contains a hole transport material. The hole transport material forming the hole transport layer 4 is preferably a material with high hole transport properties and the ability to efficiently transport injected holes. Therefore, the hole transport material forming the hole transport layer 4 is preferably one with a low ionization potential, high transparency to visible light, high hole mobility, excellent stability, and less generation of trapping impurities during manufacturing and use. In many cases, the hole transport layer 4 is in contact with the light-emitting layer 5, so it is preferable that it does not quench the light emission from the light-emitting layer 5 or form an excyplex with the light-emitting layer 5, thereby reducing efficiency.

[0353] The hole transport material for hole transport layer 4 can be any material that has been conventionally used as a constituent material for hole transport layer 4. Examples of materials for hole transport layer 4 include arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, condensed polycyclic aromatic derivatives, and metal complexes. The hole transport material used in the hole injection layer forming composition can also be used as the hole transport material forming hole transport layer 4.

[0354] Examples of hole transport materials for hole transport layer 4 include polyvinylcarbazole derivatives, polyarylamine derivatives (arylamine polymers), polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ethersulfone derivatives containing tetraphenylbenzidine, polyarylenevinylene derivatives, polysiloxane derivatives, polythiophene derivatives, and poly(p-phenylenevinylene) derivatives. These may be alternating copolymers, random polymers, block polymers, or graft copolymers. They may also be polymers with branched main chains and three or more terminal ends, or so-called dendrimers.

[0355] In particular, polyarylamine derivatives and polyarylene derivatives are preferred as the hole transport material for the hole transport layer 4. Specific examples of polyarylamine derivatives and polyarylene derivatives include those described in Japanese Patent Publication No. 2008-98619. As the polyarylamine derivative, it is preferable to use an aromatic tertiary amine polymer compound represented by formula (50).

[0356] When forming the hole transport layer 4 by a wet film deposition method, the hole transport layer forming composition is prepared in the same manner as for forming the hole injection layer 3, followed by wet film deposition and drying. The hole transport layer formation composition contains a solvent in addition to the hole transport material described above. The solvent used is the same as that used in the hole injection layer formation composition. The film formation conditions, drying conditions, etc., are also the same as those for the formation of hole injection layer 3. If the hole transport layer forming composition is the second composition in this embodiment, the solvent is the first solvent component or the second solvent component in this embodiment. When forming the hole transport layer 4 by vacuum deposition, the film formation conditions are the same as those for forming the hole injection layer 3.

[0357] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 200 nm or less, taking into consideration factors such as the penetration of low molecular weight material in the light-emitting layer 5 and the swelling of the hole transport material.

[0358] [Luminous layer] The light-emitting layer 5 is the main light-emitting layer, excited by the recombination of holes injected from the anode 2 and electrons injected from the cathode 9 between electrodes under an applied electric field. The light-emitting layer 5 is usually formed on top of the hole transport layer 4 if one is present, on top of the hole injection layer 3 if one is present but one is not, and on top of the anode 2 if neither the hole transport layer 4 nor the hole injection layer 3 is present.

[0359] <Materials for luminescent layers> Materials for light-emitting layers typically include a light-emitting material and a host charge transport material.

[0360] <Luminescent materials> As the light-emitting material, any known material commonly used as a light-emitting material in organic electroluminescent devices can be applied, and there are no particular restrictions. Any material that emits light at a desired emission wavelength and has good luminescence efficiency should be used. The light-emitting material may be a fluorescent material or a phosphorescent material, but from the viewpoint of internal quantum efficiency, a phosphorescent material is preferred. More preferably, the red and green light-emitting materials are phosphorescent materials, and the blue light-emitting material is a fluorescent material.

[0361] When the second composition in this embodiment is a composition for forming an emissive layer, it is preferable to use the following phosphorescent material, fluorescent material, and charge transport material.

[0362] <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.

[0363] 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. Examples of such phosphorescent materials include those described in International Publication No. 2014 / 024889, International Publication No. 2015-087961, International Publication No. 2016 / 194784, and Japanese Patent Publication No. 2014-074000. Preferably, the compound is represented by the following formula (201) or the following formula (205), and more preferably, the compound is represented by the following formula (201).

[0364] [ka]

[0365] In formula (201), ring A1 represents an aromatic hydrocarbon ring structure which may have substituents or an aromatic heterocyclic structure which may have substituents. Ring A2 represents an aromatic heterocyclic structure that may have substituents. R 201 , R 202 Each of these is an independent structure represented by formula (202), where "*" indicates the bond position with ring A1 or ring A2. 201 , R 202 R can be the same or different, 201 , R 202If there are multiple instances of each, they may be the same or different.

[0366] In equation (202), 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 202 This represents an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic structure, or an optionally substituted aliphatic hydrocarbon structure. The substituents bonded to ring A1 of formula (201), the substituents bonded to ring A2, or the substituents bonded to ring A1 and the substituents bonded to ring A2 may bond to each other to form a ring.

[0367] 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.

[0368] In addition, in equations (201) and (202), i1 and i2 each independently represent integers between 0 and 12 (inclusive). i3 is Ar 202 Represents a non-negative integer with an upper limit of the number that can be substituted for, i4 is Ar 201 Represents a non-negative integer with an upper limit of the number that can be substituted for, k1 and k2 each independently represent non-negative integers up to the number of numbers that can be permuted in rings A1 and A2, respectively. z represents an integer between 1 and 3.

[0369] (substituent) Unless otherwise specified, the substituent is preferably a group selected from the following substituent group S.

[0370] <Substituent group S> 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.

[0371] The groups of the above substituent group S may have one or more hydrogen atoms replaced by fluorine atoms, or one or more hydrogen atoms replaced by deuterium atoms. Unless otherwise specified, aryls are aromatic hydrocarbon rings, and heteroaryls are aromatic heterocycles.

[0372] Of the above substituent group S, preferably are 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, 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. 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.

[0373] These substituent groups S may further contain substituents selected from substituent group S. 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 S.

[0374] (Ring A1) Ring A1 represents an aromatic hydrocarbon ring structure or an aromatic heterocyclic structure that may have substituents.

[0375] The aromatic hydrocarbon ring is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, benzene rings, naphthalene rings, anthracene rings, triphenylyl rings, acenaphthene rings, fluorantene rings, and fluorene rings are preferred.

[0376] As the aromatic heterocycle, a C3 to C30 aromatic heterocycle containing a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom is preferred. More preferably, it is a furan ring, a benzofuran ring, a thiophene ring, or a benzothiophene ring. 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.

[0377] (ring A2) Ring A2 represents an aromatic heterocyclic structure that may have substituents. The aromatic heterocycle is preferably an aromatic heterocycle having 3 to 30 carbon atoms, which contains one of the following as a heteroatom: a nitrogen atom, an oxygen atom, or a sulfur atom. 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 phenanthidine rings. Preferably, these are pyridine rings, pyrazine rings, pyrimidine rings, imidazole rings, benzothiazole rings, benzoxazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, and quinazoline rings. More preferably, these are pyridine rings, imidazole rings, benzothiazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, and quinazoline rings. Most preferably, these are pyridine rings, imidazole rings, benzothiazole rings, quinoline rings, quinoxaline rings, and quinazoline rings.

[0378] (Combination of ring A1 and ring A2) Preferred combinations of ring A1 and ring A2, when denoted as (ring A1-ring A2), include (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-benzothiazole ring), (benzene ring-imidazole ring), (benzene ring-pyrrole ring), (benzene ring-diazole ring), and (benzene ring-thiophene ring).

[0379] (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 S.

[0380] (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 202 This represents an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic structure, or an optionally substituted aliphatic hydrocarbon structure.

[0381] Ar 201 Ar 202 Ar 203 If any of the elements is an aromatic hydrocarbon ring structure which may have substituents, the aromatic hydrocarbon ring 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 is preferred, more preferably a benzene ring, naphthalene ring, or fluorene ring, and most preferably a benzene ring.

[0382] 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.

[0383] 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.

[0384] Ar 201 Ar 202 Ar 203In the case of an aromatic heterocyclic structure in which any of the elements 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, and preferably pyridine rings, pyrimidine rings, triazine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings.

[0385] 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.

[0386] 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 more preferably 1 to 8 carbon atoms.

[0387] (i1, i2, i3, i4, k1, k2) i1 and i2 each independently represent integers from 0 to 12, preferably from 1 to 12, more preferably from 1 to 8, and more preferably from 1 to 6. This range is expected to improve solubility and charge transport. i3 preferably represents an integer between 0 and 5, more preferably an integer between 0 and 2, and more preferably 0 or 1. i4 preferably represents an integer between 0 and 2, and more preferably 0 or 1. k1 and k2 each independently represent integers preferably between 0 and 3, more preferably between 1 and 3, more preferably 1 or 2, and particularly preferably 1.

[0388] (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 S, and the preferred groups are also as described in substituent group S, but more preferably unsubstituted (hydrogen atom), alkyl group, or aryl group, particularly preferably unsubstituted (hydrogen atom) or alkyl group, and most preferably unsubstituted (hydrogen atom) or tertiary butyl group. The tertiary butyl group is Ar 203 If Ar 203 Ar 203 If it does not exist, Ar 202 Ar 202 and Ar 203 If it does not exist, Ar 201 It is preferable that it be substituted with

[0389] (Preferred embodiment of the compound represented by formula (201)) The compound represented by the above formula (201) is preferably a compound that satisfies one or more of the following conditions (I) to (IV). (I) Phenylene coupled type The structure represented by formula (202) is preferably a structure having a group in which benzene rings are linked, i.e., a benzene ring structure, i1 being an integer from 1 to 6, and at least one of the benzene rings being bonded to an adjacent structure at the ortho or meta position. This structure is expected to improve both solubility and charge transport.

[0390] (II)(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, i.e., Ar 201 is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, i1 is an integer from 1 to 6, Ar 202 The structure is an aliphatic hydrocarbon, i2 is an integer from 1 to 12, preferably an integer from 3 to 8, Ar 203 The structure is a benzene ring structure, i3 is 0 or 1, preferably Ar 201 This is the aforementioned aromatic hydrocarbon structure, more preferably a structure in which 1 to 5 benzene rings are linked together, and more preferably a single benzene ring. This structure is expected to improve both solubility and charge transport.

[0391] (III) Dendron A structure in which a dendron is attached to ring A1 or ring A2, for example, Ar 201 Ar 202 The benzene ring structure, Ar 203 The structure is biphenyl or terphenyl, i1 and i2 are integers from 1 to 6, i3 is 2, and j is 2. This structure is expected to improve both solubility and charge transport.

[0392] (IV)B 201 -L 200 -B 202 B 201 -L 200 -B 202 The structure represented by is preferably the structure represented by the following formula (203) or formula (204).

[0393] [ka]

[0394] In formula (203), R 211 , R 212 , R 213 Each of these independently represents a substituent. 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.

[0395] (Preferred phosphorescent material) The phosphorescent material represented by the above formula (201) is not particularly limited, but the following are preferred.

[0396] [ka]

[0397] [ka]

[0398] Furthermore, phosphorescent materials represented by the following formula (205) are also preferred.

[0399] [ka]

[0400] (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.)

[0401] In formula (205), M 2 Specific examples include metals selected from groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold are preferred, and divalent metals such as platinum and palladium are particularly preferred.

[0402] Also, in equation (205), R 92 and R 93Each 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.

[0403] Furthermore, if T is a carbon atom, R 94 and R 95 Each of them is independent of R 92 and R 93 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. 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.

[0404] (molecular weight) The molecular weight of the phosphorescent material is preferably 5000 or less, more preferably 4000 or less, and particularly preferably 3000 or less. Furthermore, the molecular weight of the phosphorescent material is preferably 800 or more, more preferably 1000 or more, and even more preferably 1200 or more. 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.

[0405] 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.

[0406] <Charge transport material> The charge transport material used in the light-emitting layer is preferably a material having a framework with excellent charge transport properties, and is selected from electron transport materials, hole transport materials, and bipolar materials capable of transporting both electrons and holes.

[0407] 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.

[0408] 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.

[0409] Hole-transporting materials are compounds having a structure that exhibits excellent hole transport properties. Among the central skeletons exhibiting excellent charge transport properties, carbazole structures, dibenzofuran structures, triarylamine structures, naphthalene structures, phenanthrene structures, or pyrene structures are preferred as structures with excellent hole transport properties, and carbazole structures, dibenzofuran structures, or triarylamine structures are even more preferred.

[0410] The charge transport material used in the light-emitting layer preferably has a fused ring structure of three or more rings, and more preferably is a compound having two or more fused ring structures of three or more rings, or a compound having at least one fused ring of five or more rings. These compounds increase molecular rigidity, making it easier to suppress the degree of molecular motion that responds to heat. Furthermore, the fused rings of three or more rings and the fused rings of five or more rings preferably have aromatic hydrocarbon rings or aromatic heterocycles, in terms of charge transport properties and material durability.

[0411] Examples of condensed 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. From the viewpoint of charge transport and solubility, at least one selected from the group consisting of phenanthrene structures, fluorene structures, indenofluorene structures, carbazole structures, indenocarbazole structures, indolocarbazole structures, dibenzofuran structures, and dibenzothiophene structures is preferred, and from the viewpoint of resistance to charge, carbazole structures or indolocarbazole structures are more preferred.

[0412] In this embodiment, from the viewpoint of the charge resistance of the organic electroluminescent element, it is preferable that at least one of the charge transport materials in the light-emitting layer is a material having a pyrimidine skeleton or a triazine skeleton.

[0413] The charge transport 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 the light-emitting layer of an organic electroluminescent element formed on a flexible substrate. When the charge transport material contained in the light-emitting layer is a polymer material, the weight-average molecular weight is preferably 5,000 or more, more preferably 10,000 or more, preferably 1,000,000 or less, more preferably 500,000 or less, and even more preferably 100,000 or less.

[0414] Furthermore, the charge transport material for 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 adjusting viscosity when dissolved in a solvent. When the charge transport material contained in the light-emitting layer is a low molecular weight material, the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, most preferably 2,000 or less, preferably 300 or more, more preferably 350 or more, and even more preferably 400 or more.

[0415] <Fluorescent materials> The fluorescent material is not particularly limited, but compounds represented by the following formula (211) are preferred.

[0416] [ka]

[0417] In the above equation (211), Ar 241 represents an aromatic hydrocarbon condensed ring structure which may have substituents, and Ar 242 Ar 243 Each of these independently represents an alkyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, or a group to which these are bonded, which may each have substituents. n41 is an integer from 1 to 4.

[0418] Ar 241 Preferably, it represents an aromatic hydrocarbon condensed ring structure with 10 to 30 carbon atoms, and specific ring structures include naphthalene, acenaphthene, fluorene, anthracene, and phena. hmm Examples include trene, fluorantene, pyrene, tetracene, chrycene, and perylene. Ar 241 It is more preferably an aromatic hydrocarbon condensed ring structure having 12 to 20 carbon atoms, and specific ring structures include acenaphthene, fluorene, anthracene, and phena hmm Examples include trene, fluorantene, pyrene, tetracene, chrysene, and perylene. Ar 241 More preferably, it is an aromatic hydrocarbon condensed ring structure having 16 to 18 carbon atoms, and specific examples of ring structures include fluorantene, pyrene, and chrysene.

[0419] n41 is an integer from 1 to 4, preferably an integer from 1 to 3, more preferably 1 or 2, and most preferably 2.

[0420] Ar 242 Ar 243 The alkyl group is preferably an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Ar 242 Ar 243 The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably an aromatic hydrocarbon group having 6 to 24 carbon atoms, and most preferably a phenyl group or a naphthyl group. Ar 242 Ar 243 The aromatic heterocyclic group is preferably an aromatic heterocyclic group having 3 to 30 carbon atoms, more preferably an aromatic heterocyclic group having 5 to 24 carbon atoms, specifically a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group, with the dibenzofuranyl group being more preferred.

[0421] Ar 241 Ar 242 Ar 243 The substituents that may be present are preferably groups selected from the substituent group S, more preferably hydrocarbon groups included in substituent group S, and even more preferably hydrocarbon groups among the groups preferred as substituent group S.

[0422] The charge transport material used with the above-mentioned fluorescent material is not particularly limited, but one represented by the following formula (212) is preferred.

[0423] [ka]

[0424] In the above equation (212), R 251 , R 252 Each of these is independently represented by the following equation (213), and R 253 R represents a substituent, 253If there are multiple values, they may be the same or different, and n43 is an integer between 0 and 8.

[0425] [ka]

[0426] In the above equation (213), * represents the bond with the anthracene ring in equation (212), and Ar 254 Ar 255 Each of these independently represents an aromatic hydrocarbon structure which may have substituents, or a heteroaromatic ring structure which may have substituents, and Ar 254 Ar 255 If there are multiple instances of each, they may be the same or different, and n44 is an integer from 1 to 5, and n45 is an integer from 0 to 5.

[0427] Ar 254 Preferably, it is an aromatic hydrocarbon structure having 6 to 30 carbon atoms and being a monocyclic or fused ring, which may have substituents, and more preferably, it is an aromatic hydrocarbon structure having 6 to 12 carbon atoms and being a monocyclic or fused ring, which may have substituents.

[0428] Ar 255 Preferably, it is an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 30 carbon atoms and may have substituents, or an aromatic heterocyclic structure which is a fused ring having 6 to 30 carbon atoms and may have substituents. 255 More preferably, it is an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 12 carbon atoms and may have substituents, or an aromatic heterocyclic structure which is a fused ring having 6 to 12 carbon atoms and may have substituents.

[0429] n44 is preferably an integer between 1 and 3, and more preferably 1 or 2. n45 is preferably an integer between 0 and 3, and more preferably an integer between 0 and 2.

[0430] R is a substituent. 253 Ar 254 and Ar255 The substituents that may be present are preferably groups selected from the substituent group S. More preferably, they are hydrocarbon groups included in substituent group S, and even more preferably, they are hydrocarbon groups among the groups preferred as substituent group S.

[0431] The weight molecular weight of the fluorescent material and the charge transport material is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably 2,000 or less. It is also preferably 300 or more, more preferably 350 or more, and even more preferably 400 or more.

[0432] [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 within the electron transport layer that also plays a role in preventing holes moving from the anode 2 from reaching the cathode 9. The hole blocking layer 6 is a layer that is laminated on top of 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.

[0433] The 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.

[0434] 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 energy level (T1). Examples of materials for the hole blocking layer 6 that satisfy these conditions include mixed ligand complexes such as bis(2-methyl-8-quinolinolato)(phenolato)aluminum and bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum, metal complexes such as bis(2-methyl-8-quinolato)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 basocuproine (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 the hole blocking layer 6.

[0435] There are no restrictions on the method of forming the hole blocking layer 6. The hole blocking layer 6 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. The thickness of the hole blocking layer 6 is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[0436] [Electron transport layer] The electron transport layer 7 is a layer provided between the light-emitting layer 5 and the cathode 9 for transporting electrons.

[0437] Typically, the electron transport material used for the electron transport layer 7 is a compound that has high electron injection efficiency from the cathode 9 or the adjacent layer on the cathode 9 side, and also has high electron mobility, enabling efficient transport of injected electrons. Examples of compounds that satisfy these conditions include metal complexes such as aluminum and lithium 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, triazine compound derivatives, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

[0438] As the electron transport material used in the electron transport layer 7, electron transporting organic compounds, such as nitrogen-containing heterocyclic compounds like bathophenanthroline or metal complexes like aluminum complexes of 8-hydroxyquinoline, are preferred because they can be doped 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.) to achieve both electron injection transport properties and excellent film quality. Furthermore, doping the above-mentioned electron transporting organic compounds with inorganic salts such as lithium fluoride or cesium carbonate is also effective.

[0439] There are no restrictions on the method of forming the electron transport layer 7. The electron transport layer 7 can be formed by wet deposition, vapor deposition, or other methods.

[0440] The thickness of the electron transport layer 7 is arbitrary as long as it does not significantly impair the effects of the present invention. 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.

[0441] [Electron injection layer] To efficiently inject electrons from the cathode 9 into the light-emitting layer 5, an electron injection layer 8 may be provided between the electron transport layer 7 and the cathode 9, which will be described later. The electron injection layer 8 is made of an inorganic salt or the like.

[0442] Examples of materials for the electron injection layer 8 include lithium fluoride (LiF), magnesium fluoride (MgF2), lithium oxide (Li2O), and cesium(II) carbonate (CsCO3) (see Applied Physics Letters, 1997, Vol. 70, pp. 152; Japanese Patent Publication No. 10-74586; IEEE Transactions on Electron Devices, 1997, Vol. 44, pp. 1245; SID 04 Digest, pp. 154, etc.).

[0443] Since the electron injection layer 8 often does not have charge transport properties, it is preferable to use it as an ultrathin film in order to efficiently perform electron injection, and its film thickness is usually 0.1 nm or more, preferably 5 nm or less.

[0444] [cathode] The cathode 9 is an electrode that plays the role of injecting electrons into the layer on the light-emitting layer 5 side.

[0445] Common materials for the cathode 9 include 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; or conductive polymers such as poly(3-methylthiophene), polypyrrole, and polyaniline. Of these, metals with low work functions are preferred for efficient electron injection, and suitable metals such as tin, magnesium, indium, calcium, aluminum, and silver, or alloys thereof, are used. Specific examples include low-work-function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0446] The cathode 9 material may consist of only one type, or two or more types may be used in any combination and ratio.

[0447] The thickness of the cathode 9 varies depending on the required transparency. If transparency is required, the transmittance of visible light is usually 60% or more, preferably 80% or more. In this case, the thickness of the cathode 9 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably around 500 nm or less. If opacity is acceptable, the thickness of the cathode 9 is arbitrary, and the cathode may be the same thickness as the substrate.

[0448] It is also possible to layer different conductive materials on top of cathode 9. For example, to protect a cathode made of a low-work-function metal such as alkali metals like sodium or cesium, or alkaline earth metals like barium or calcium, it is preferable to further laminate a metal layer with a high work function and stability to the atmosphere on top of it, as this increases the stability of the device. For this purpose, metals such as aluminum, silver, copper, nickel, chromium, gold, and platinum are used. These materials may be used individually, or two or more may be used in any combination and ratio.

[0449] [Other layers] The organic electroluminescent element in this embodiment may have a different configuration, without departing from its spirit. For example, as long as its performance is not impaired, there may be any additional layers between the anode 2 and cathode 9 besides the layers described above, and non-essential layers among the layers described above may be omitted.

[0450] In the layer configuration described above, it is also possible to stack the components other than the substrate in the reverse order. For example, in the layer configuration shown in Figure 1, the other components may be placed on the substrate 1 in the following order: cathode 9, electron injection layer 8, electron transport layer 7, hole blocking layer 6, light-emitting layer 5, hole transport layer 4, hole injection layer 3, and anode 2.

[0451] The organic electroluminescent element in this embodiment may be configured as a single organic electroluminescent element, or it may be applied to a configuration in which multiple organic electroluminescent elements are arranged in an array, or it may be applied to a configuration in which the anode and cathode are arranged in an XY matrix.

[0452] Each of the above-mentioned layers may contain components other than those described as materials, as long as they do not significantly impair the effects of the present invention.

[0453] <Organic electroluminescent devices> By providing two or more organic electroluminescent elements that emit light in different colors, an organic electroluminescent device such as an organic EL display device or organic EL lighting can be created. In this organic electroluminescent device, by using at least one, preferably all, organic electroluminescent elements as described in this embodiment, a high-quality organic electroluminescent device can be provided.

[0454] <Organic EL display device> There are no particular restrictions on the type or structure of the organic EL display device using the organic electroluminescent element in this embodiment, and it can be assembled according to conventional methods using the organic electroluminescent element in this embodiment. For example, an organic EL display device can be formed using the method described in "Organic EL Display" (Ohmsha, published August 20, 2004, authored by Shizuka Tokito, Chihaya Adachi, and Hideyuki Murata). [Examples]

[0455] <Synthesis of arylamine polymer 1>

[0456] [ka]

[0457] The arylamine polymer 1 represented by the above formula was synthesized by a conventionally known method. Its weight-average molecular weight was 29140, its molecular weight distribution (expressed as weight-average molecular weight / number-average molecular weight) was 1.25, and its glass transition temperature was 229°C.

[0458] <Formation of the first functional membrane> A glass substrate with a thickness of 0.7 mm and dimensions of 25 x 37 mm was cleaned using UV / ozone. The arylamine polymer 1 prepared above was used as the first functional material, and a first composition was prepared by dissolving it in anisole, a solvent, and this was deposited as a film over the entire surface of a glass substrate by spin coating. The arylamine polymer content in the first composition was 3.2% by mass. This was heated at 220°C for 30 minutes under an N2 atmosphere to obtain an insoluble first functional film with a thickness of 100 nm.

[0459] <Immersion of the first functional membrane> 130 μL of the solvent component of the second composition, as listed in Table 1, was taken and dropped onto the first functional film. After holding in an atmospheric environment at 23°C for the time indicated in Table 1 (5 to 15 minutes), the solvent was removed by rotating the glass substrate at 3000 rpm for 2 minutes using a spin coater. Next, it was dried in a vacuum dryer heated to 30°C for at least 3 minutes. The achieved vacuum level was 10 Pa or less. Subsequently, the solvent was completely removed by heating at 100°C for 1 minute and then at 230°C for 10 minutes. The holding time (immersion time), the viscosity of the solvent components at 23°C, and the Hansen solubility parameter δP of the solvent components are as shown in Table 1, along with the structural formulas of each solvent component. Furthermore, the second composition described above contains only a solvent component. Therefore, the viscosity of the second composition at 23°C is the same as the viscosity of the solvent component when there is only one solvent component, i.e., in Examples 1-8 and Comparative Examples 1-4. Here, since the viscosity of Example 8 is greater than 15 mPa·s, when actually obtaining an organic semiconductor device, it is preferable to make the viscosity of the second composition 15 mPa·s or less by adding a low viscosity solvent, reducing the solid content concentration in the second composition, or using a solid component with a low molecular weight that does not easily increase viscosity. When there are two solvent components, i.e., in Examples 9 and 10, the viscosity of the second composition is determined by the viscosity of the two solvent components and their content ratio.

[0460] <Measurement of the film thickness of the first functional film> The thickness of the first functional film was determined using a reflectance spectrometer (OPTM). The reflection spectra at eight in-plane locations of the first functional film were measured, with the measurement locations being consistent across the substrates. The reflection spectra were measured before and after the immersion of the first functional film. Prior to the experiment, nine thin films with different thicknesses of the first functional film were prepared by varying the concentration of the arylamine polymer in the first composition and the spin-coating rotation speed. A calibrated optical model was generated by correlating the step thickness measured by a KOSAKA surfcoder with the reflection spectrum. The optical thickness at eight locations was calculated using the optical model from the measured reflection spectra.

[0461] <Calculation of residual film percentage> For each level and each of the eight locations within the plane, the change in the thickness of the first functional film before and after immersion was divided, and the average of the eight remaining film percentages was taken as the remaining film percentage for the level. The results are shown in Table 1. In this example, a second composition consisting of at least one of the first and second solvent components was used. However, the residual film ratio would show a similar trend if a second functional film containing a second functional material were also provided.

[0462] <Solvent determination formula> As a reference for determining the suitability of individual solvent components, the values ​​represented by the left-hand side of the following relational equation (A) were calculated for each solvent component used in Examples 1-8 and Comparative Examples 1-4. The results are shown in the section on Rejection Equation (A) in Table 1. 32 × viscosity - 4.3 × theoretical surface area + 5.4 × volume - boiling point > 150···(A) The theoretical surface area and volume in the above relation (A) were calculated using the method described in A. Klamt, "COSMO-RS: From Quantum Chemistry to Fluid Phase Thermodynamics and Drug Design," Elsevier Science, 1st edition (September 29, 2005). If the above relation (A) is satisfied, that is, if the value calculated on the left side is greater than 150, then such a solvent component can be judged as suitable as the first solvent component. Also, in Table 1, "-" indicates that the value has not been calculated.

[0463] <Flow-activated energy> The fluid activation energy is E in equation (I) below. The fluid activation energy is determined by measuring the viscosity of the solvent at different temperatures, plotting the logarithm of viscosity against the reciprocal of temperature, and taking the slope of the plot. η = A exp(E / RT) (I) η: Viscosity (cP) A: Constant E: Fluid activation energy (kJ / mol) R: Gas constant (8.314 J / K / mol) T: Temperature (K) In this invention, the viscosity of the solvent is measured using an E-type viscometer RE85L (manufactured by Toki Sangyo Co., Ltd.) at 23°C with a cone plate rotation speed of 20 rpm to 100 rpm.

[0464] [Table 1]

[0465] As shown in Table 1, when a first solvent component satisfying a viscosity of 3 mPa·s or higher and / or a flow activation energy of 17 kJ / mol or higher at 23°C was used, the elution of the first functional film could be suppressed even with an immersion time of 15 minutes. This also correlates with the value expressed on the left side of relation (A), demonstrating that it is possible to select a solvent component that suppresses the elution of the first functional material. The reason the residual film rate exceeds 100% is that a slight deviation occurs from the optical model used to fit the optical film thickness due to changes in optical properties. Furthermore, the residual film rate was high in Examples 9 and 10, which included the first solvent component of Example 5 and the second solvent component of Comparative Example 5. This indicates that by including an appropriate solvent as the first solvent, the elution of the first functional material can be suppressed even in the presence of the second solvent.

[0466] [ka]

[0467] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0468] This application is based on Japanese Patent Application No. 2021-076580 filed on April 28, 2021, and its contents are incorporated herein by reference. [Explanation of symbols]

[0469] 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 step of applying and heating the first composition to provide a first functional film, The process includes the step of applying a second composition onto the first functional film to provide a second functional film, The first composition comprises a first functional material, The first functional material comprises an arylamine polymer having a weight-average molecular weight of 15,000 or more and 50,000 or less, which does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups. The second composition contains a solvent and has a viscosity of 15 mPa·s or less at 23°C. The solvent comprises at least one first solvent component having a viscosity of 3 mPa·s or more at 23°C, and a second solvent component having a viscosity of less than 3 mPa·s at 23°C. The ratio of the first solvent component to the sum of the first and second solvent components is 15% by mass or more and 50% by mass or less. A method for manufacturing an organic semiconductor device, wherein the ratio of the second solvent component to the sum of the first and second solvent components is 50% by mass or more and 85% by mass or less.

2. The method for manufacturing an organic semiconductor device according to Claim 1, wherein the fluid activation energy of the first solvent component is 17 kJ / mol or more.

3. A step of applying and heating the first composition to provide a first functional film, The process includes the step of applying a second composition onto the first functional film to provide a second functional film, The first composition comprises a first functional material, The first functional material comprises an arylamine polymer that does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups. The second composition contains a solvent and has a viscosity of 15 mPa·s or less at 23°C. The solvent contains at least one first solvent component having a fluid activation energy of 17 kJ / mol or more. The solvent further comprises a second solvent component having a viscosity of less than 3 mPa·s at 23°C. The ratio of the first solvent component to the sum of the first and second solvent components is 15% by mass or more and 50% by mass or less. A method for manufacturing an organic semiconductor device, wherein the ratio of the second solvent component to the sum of the first and second solvent components is 50% by mass or more and 85% by mass or less.

4. The method for producing an organic semiconductor device according to claim 3, wherein the weight-average molecular weight of the arylamine polymer is 15,000 or more and 50,000 or less.

5. A step of applying and heating the first composition to provide a first functional film, The process includes the step of applying a second composition onto the first functional film to provide a second functional film, The first composition comprises a first functional material, The first functional material comprises an arylamine polymer that does not have any crosslinking groups, polymerization groups, or detachable solubilizing groups. The second composition contains a solvent and has a viscosity of 15 mPa·s or less at 23°C. The solvent contains at least one first solvent component having a viscosity of 3 mPa·s or more at 23°C. The solvent further comprises a second solvent component having a viscosity of less than 3 mPa·s at 23°C. The fluid activation energy of the first solvent component is 17 kJ / mol or more. The ratio of the first solvent component to the sum of the first and second solvent components is 15% by mass or more and 50% by mass or less. A method for manufacturing an organic semiconductor device, wherein the ratio of the second solvent component to the sum of the first and second solvent components is 50% by mass or more and 85% by mass or less.

6. The method for producing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the arylamine polymer has repeating units represented by the following formula (50). 【Chemistry 1】 (In formula (50), Ar ５１ This represents a group consisting of one or more linked groups, selected from at least one of an aromatic hydrocarbon group which may have substituents and an aromatic heterocyclic group which may have substituents, and all substituents are groups other than crosslinking groups, polymerization groups, or leaving solubilizing groups. Ar ５２ This represents a divalent group formed by linking one or more groups selected from at least one of a substituted divalent aromatic hydrocarbon group and a substituted divalent aromatic heterocyclic group, wherein the linking is made directly or via linking groups, and all substituents are groups other than crosslinking groups, polymerization groups, or leaving solubilizing groups. Ar ５１ and Ar ５２ These may be directly or via linking groups to form a ring. However, Ar ５１ Ar ５２ It does not have any crosslinking groups, polymerization groups, or leaving solubilizing groups.

7. The method for producing an organic semiconductor device according to claim 6, wherein the arylamine polymer includes a structure in which a plurality of benzene ring structures are linked at the para position in the main chain, and at least one of the plurality of benzene ring structures has a substituent on at least one of the two carbon atoms located next to the carbon atom bonded to the adjacent benzene ring structure.

8. A method for manufacturing an organic semiconductor device according to claim 6, wherein the repeating unit represented by formula (50) is represented by the following formula (54). 【Chemistry 2】 (In formula (54), Ar ５１ Ar in formula (50) ５１ It is similar to, X is -C(R ７ )(R ８ )-, -N(R ９ )- or -C(R １１ )(R １２ )-C(R １３ )(R １４ )-, and R １ and R ２ Each of these is independently an alkyl group which may have substituents, and the substituent is a group other than a crosslinking group, a polymerization group, or a detachable solubilizing group. R ７ ~R ９ and R １１ ~R １４ Each of these is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group, and all of the substituents are groups other than crosslinking groups, polymerization groups, or leaving solubilizing groups. a and b are each independent integers between 0 and 4. c is an integer between 1 and 3. d is an integer between 0 and 4. R １ If there are multiple R's, １ They may be the same or different. R ２ If there are multiple R's, ２ They may be the same or different.

9. The method for manufacturing an organic semiconductor element according to claim 8, wherein the value represented by a + b in formula (54) is 1 or more.

10. A method for manufacturing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the Hansen solubility parameter δP of the first solvent component satisfies the relationship δP < 7.

11. A method for manufacturing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein it takes two minutes or more from the time the second composition is applied onto the first functional film until the solvent evaporates.

12. The second composition comprises a second functional material different from the first functional material, The method for producing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the second functional material comprises a low molecular weight aromatic compound having a molecular weight of less than 2000.

13. A method for manufacturing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the first functional film is a hole transport layer and the second functional film is a light-emitting layer.

14. A method for manufacturing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the heating in the step of providing the first functional film is performed at a temperature lower than the glass transition temperature of the arylamine polymer.

15. The theoretical surface area (Å) of the first solvent component calculated using the COSMO-RS solvation model. ２ ), volume (Å ３ A method for manufacturing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the temperature and boiling point (°C), and viscosity at 23°C (mPa·s) satisfy the following relational expression (A). 32 × viscosity - 4.3 × theoretical surface area + 5.4 × volume - boiling point > 150 ... (A)

16. A method for producing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the total content of the first solvent components in the second composition is 15% by mass or more.

17. A method for producing an organic semiconductor device according to any one of claims 1, 3, and 5, wherein the first solvent component includes an aromatic hydrocarbon structure.

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