Organic electroluminescent element

Abstract

This invention provides a practically useful material and premixed composition for organic electric field light-emitting elements (OLEDs) that exhibits low voltage, high efficiency, and long lifespan, as well as OLEDs using these characteristics. An OLED material is represented by any one of the following general formulas (1) to (7). (Y represents O, etc., Ar...) 7 ~Ar 9 Each is independently an aromatic heterocyclic group having 3 to 17 carbon atoms, either substituted or unsubstituted, and at least one is represented by formula (1a); Ar 1 and Ar 2 Each of the above is an aromatic hydrocarbon group, either substituted or unsubstituted, having 6 to 18 carbon atoms, and represents the bonding position with the general formulas (1) to (7); R 1 ~R 4 X can be independently identified as hydrogen, deuterium, etc. 1 ~X 3 Each is independently represented by N, R by deuterium, and a to d by substitution numbers, where a and c are integers from 1 to 4, and b and d are integers from 1 to 2.

Description

Technical Field

[0001] This invention relates to an organic electric field light-emitting element (hereinafter referred to as an organic EL element), and more specifically, to an organic EL element comprising a specific hybrid host material. Background Technology

[0002] By applying a voltage to an organic EL (electroluminescence) device, holes are injected into the emissive layer from the anode, and electrons are injected into the emissive layer from the cathode. In the emissive layer, the injected holes and electrons recombine to generate excitons. At this point, according to the statistical law of electron spin, singlet and triplet excitons are generated in a 1:3 ratio. Regarding fluorescent organic EL devices using light emitted from singlet excitons, the internal quantum efficiency is considered to be limited to 25%. On the other hand, phosphorescent organic EL devices using light emitted from triplet excitons have achieved an internal quantum efficiency of 100% by efficiently performing intersystem crossings from singlet excitons.

[0003] High-efficiency organic EL devices utilizing delayed fluorescence are currently under development. For example, Patent Document 1 discloses an organic EL device that utilizes the triplet-triplet fusion (TTF) mechanism, one of the mechanisms of delayed fluorescence. The TTF mechanism utilizes the phenomenon of generating singlet excitons through the collision of two triplet excitons, theoretically increasing the internal quantum efficiency to 40%. However, compared with phosphorescent organic EL devices, its efficiency is low, thus requiring further improvements in efficiency and low-voltage characteristics.

[0004] Furthermore, Patent Document 2 discloses an organic EL device that utilizes the thermally activated delayed fluorescence (TADF) mechanism. The TADF mechanism leverages the phenomenon that, in materials with a small energy difference between singlet and triplet levels, an inverse intersystem crossing occurs from a triplet exciton to a singlet exciton, theoretically increasing the internal quantum efficiency to 100%.

[0005] However, there is room for improvement in efficiency and lifespan in either mechanism, and improvements are also needed regarding the reduction of drive voltage.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: WO2010 / 134350

[0009] Patent Document 2: WO2011 / 070963

[0010] Patent Document 3: Korean Patent Publication No. 2015-0095186

[0011] Patent Document 4: Korean Patent Publication No. 20110016288

[0012] Patent Document 5: WO2011 / 019173

[0013] Patent Document 6: WO2014 / 057684

[0014] Patent Document 7: WO2018 / 043435

[0015] Patent Document 8: Korean Patent No. 101959821

[0016] Patent Document 9: WO2015 / 169412

[0017] Patent Document 10: Korean Patent Publication No. 20140097044

[0018] Patent Document 11: Korean Patent Publication No. 20160146619

[0019] Patent documents 3, 4, 5, and 6 disclose the use of specific cyclic compounds containing oxogroup elements such as oxygen or sulfur atoms and nitrogen atoms as the main material of the light-emitting layer.

[0020] Patent document 7 discloses a mixed host material for the light-emitting layer, which is a specific cyclic compound containing oxalic elements such as oxygen or sulfur atoms and nitrogen atoms, and a biscarbazole compound.

[0021] Patent documents 8 and 9 disclose the use of a specific azazine-substituted dibenzofuran compound and a biscarbazole compound as a mixed host material for the luminescent layer.

[0022] Patent documents 10 and 11 disclose examples of the synthesis of specific cyclic compounds containing nitrogen atoms.

[0023] However, none of these measures can be considered sufficient, and further improvements are expected. Summary of the Invention

[0024] The problem that the invention aims to solve

[0025] Compared to liquid crystal displays (LCDs), organic EL displays (OLEDs) are characterized by their thinness, light weight, high contrast, and ability to display high-speed animations. Furthermore, their design flexibility, such as curved or flexible designs, is highly valued, and they are widely used in display devices such as mobile phones and televisions. However, to reduce battery consumption when used in portable devices, further reduction in voltage is needed. Additionally, as a light source, OLEDs are inferior to inorganic light-emitting diodes (LEDs) in terms of brightness and lifespan, thus requiring improvements in efficiency and device lifespan. In view of this situation, the object of the present invention is to provide a material for an organic field-emitting element that enables the realization of a practically useful organic EL element with low voltage, high efficiency, and long lifespan.

[0026] Technical means to solve the problem

[0027] Through diligent research, the inventors discovered that by using a specified host material in the light-emitting layer, wherein a specific hybrid host material is used, the organic electric field light-emitting element can solve the aforementioned problem, thus completing the present invention.

[0028] The present invention is a material for an organic electric field light-emitting element, which is represented by any one of the following general formulas (1) to (7).

[0029] [Chemistry 1]

[0030]

[0031] In general formulas (1) to (7), Y is selected from O, S, N-Ar. 9 either of them, Ar 7 Ar 8 and Ar 9 Ar is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 7 of these aromatic groups. 7 ~Ar 9 At least one of them represents the expression represented by equation (1a). Ar 1 and Ar 2 Each of these groups is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 3 of these aromatic groups. This indicates the bond position with respect to general formulas (1) to (7). 1 ~R 4Each of these groups is independently hydrogen, deuterium, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 3 of these aromatic groups. Wherein, when R... 1 ~R 4 When the group is an aromatic hydrocarbon group, it can condense with the benzene ring to form a ring. X 1 ~X 3 Each is independently N, CH, or CR, and at least one is N. R is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 3 of these aromatic groups. a to d are the number of substitutions, where a and c are integers from 1 to 4, and b and d are integers from 1 to 2.

[0032] The preferred embodiment of the present invention is as follows: in the general formulas (1) to (7), R 1 ~R 4 It is hydrogen, deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of two of these aromatic groups; Y is O or S; Ar 1 and Ar 2 At least one of them is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or any substituted or unsubstituted linked aromatic group formed by two linked aromatic rings of these; satisfying any one of the above conditions.

[0033] Furthermore, the present invention is as follows: an organic electric field light-emitting element comprising one or more organic layers between opposing anodes and cathodes, characterized in that at least one organic layer contains an organic electric field light-emitting element material represented by general formulas (1) to (7). Furthermore, the organic light-emitting element is an organic electric field light-emitting element comprising one or more light-emitting layers between opposing anodes and cathodes, and at least one light-emitting layer contains a first host selected from compounds represented by general formulas (1) to (7), a second host selected from compounds represented by general formula (8), and a light-emitting dopant material. Moreover, the first host and the second host are different compounds. The compounds represented by general formulas (1) to (7) are used as the first host (also called an electron transport host and an N-type host) due to their excellent electron injection transport capabilities.

[0034] [Chemistry 2]

[0035]

[0036] In the general formula (8), Ar 5 and Ar 6 Each of the following groups independently represents hydrogen, deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 5 of these aromatic groups. L independently represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms. R 5 ~R 6 Each group is independently hydrogen, deuterium, or an aliphatic hydrocarbon group with 1 to 10 carbon atoms, g to j represent the number of substitutions, g and h are integers from 1 to 4, and i and j are integers from 1 to 3.

[0037] As a compound of the general formula (8), it has the form represented by the following formula (9). In formula (9), the symbols used in the general formula (8) have the same meaning.

[0038] [Chemistry 3]

[0039]

[0040] A preferred embodiment of the present invention is as follows: in the general formula (8) or formula (9), g~j is g+h+i+j=14; R 5 and R 6 At least one of them is deuterium; or Ar 5 and Ar 6 It is a substituted or unsubstituted phenyl, biphenyl, or terphenyl; satisfying any of the above.

[0041] The preferred luminescent dopant material is an organometallic complex containing at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold; or a thermally activated delayed fluorescence dopant material may be used.

[0042] Furthermore, the present invention is a mixed composition characterized by comprising a compound represented by any one of general formulas (1) to (7) as a first main body, and a compound represented by any one of general formulas (8) or (9) as a second main body, wherein preferably, it is a mixed composition formed by mixing a compound represented by any one of general formulas (1) to (7) as a first main body and a compound represented by general formula (9) as a second main body. The mixed composition may be a powder, solid, or film, as long as it comprises a compound represented by any one of general formulas (1) to (7) as a first main body and a compound represented by any one of general formulas (8) or (9) as a second main body. Furthermore, the mixed composition can be prepared by mixing a main compound, including a compound represented by general formulas (1) to (7) as the first main body and a compound represented by any one of general formulas (8) or (9) as the second main body, in a powder state. It can also be prepared by melting the compound under reduced pressure or in an inert gas atmosphere such as nitrogen, thereby performing melt mixing. Alternatively, it can be prepared by sublimating the compounds to be mixed together. Alternatively, it can be prepared as a vapor-deposited film by methods such as vapor deposition. The vapor-deposited film can be prepared by vaporization from a single evaporation source or by vaporization from different evaporation sources. Furthermore, the vapor-deposited film includes a light-emitting layer having a dopant (a luminescent dopant material).

[0043] Regarding the mixing ratio of the mixed composition, whether it is mixed in powder form, vaporized from different evaporation sources, or in film form, the ratio of the compounds represented by general formulas (1) to (7) to the total of the compounds represented by general formulas (8) or (9) is preferably 10 wt% or more and less than 80 wt%, more preferably 20 wt% or more and less than 70 wt%.

[0044] Furthermore, the present invention is a method for manufacturing an organic EL element, characterized by comprising the following steps: when manufacturing the organic electric field light-emitting element, a premixed composition is prepared by pre-mixing powders of a compound represented by any one of general formulas (1) to (7) as a first main body and a compound represented by any one of general formulas (8) or (9) as a second main body, and then a light-emitting layer is formed by vapor deposition of a main material containing the premixed composition. Here, in this specification, the premixed composition refers to a composition containing powders of a compound represented by any one of general formulas (1) to (7) as a first main body and a compound represented by any one of general formulas (8) or (9) as a second main body.

[0045] In the mixed composition and the premixed composition, the difference in temperature between the first body and the second body when the weight decreases by 50% is preferably within 20°C.

[0046] The effects of the invention

[0047] According to the present invention, by using specified materials for organic field light-emitting elements, practically useful organic EL elements with low voltage, high efficiency, and long lifetime characteristics can be realized. Specifically, by mixing a specific condensed heterocyclic compound containing oxogroup elements such as oxygen or sulfur atoms and nitrogen atoms as a first host and a specific biscarbazole compound as a second host, an organic EL element with low voltage, high efficiency, and long lifetime can be obtained. Attached Figure Description

[0048] Figure 1 This is a schematic cross-sectional view showing an example of an organic EL element. Detailed Implementation

[0049] The organic field light-emitting element material of the present invention comprises compounds represented by general formulas (1) to (7). The compounds of general formulas (1) to (7) can be suitably formed into an organic field light-emitting element as follows: That is, the organic field light-emitting element of the present invention is an organic field light-emitting element having multiple organic layers between the anode and cathode, wherein the organic layers include at least one light-emitting layer, the light-emitting layer comprising a compound represented by any one of general formulas (1) to (7) (first host), a compound represented by general formula (8) or general formula (9) (second host), and a light-emitting dopant material. The first host and the second host perform different charge injection transport in the light-emitting layer; in this application, the first host mainly performs electron injection transport, and the second host mainly performs hole injection transport. Here, as a material for an organic field light-emitting element, the compounds represented by any one of general formulas (1) to (7) have excellent electron injection transport capabilities and are useful as the electron injection transport host material (also called an N-type host material). Hereinafter, the compounds represented by general formulas (1) to (7) are also called the first subject, and the compounds represented by general formulas (8) or (9) are also called the second subject.

[0050] In general formulas (1) to (7), the shared symbols have the same meaning, preferably general formulas (1) to (6), and more preferably general formulas (1) to (2). X 1 ~X 3 Each is independently N, CH, or CR, and at least one is N. X is preferred. 1 ~X 3 In this context, two or more are represented by N. X is a more preferred term. 1 ~X 3All are N. Y is independently O, S, or N-Ar. 9 Preferably, it is O or S, more preferably O.

[0051] Ar 7 ~Ar 9 Each of these is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 7 aromatic rings of these aromatic groups. Preferably, it is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 15 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 3 of the aforementioned aromatic hydrocarbon groups. 1 and Ar 2 Each is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 3 of these aromatic groups. Preferably, Ar... 1 and Ar 2 At least one of them is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by two linked aromatic rings of these.

[0052] As the Ar 7 ~Ar 9 Specific examples of unsubstituted aromatic hydrocarbon groups having 6 to 18 carbon atoms, unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or linked aromatic groups consisting of 2 to 7 of these aromatic rings, include: benzene, naphthalene, acenaphthene, azulene, anthracene, phenylene oxide, pyrene, phenanthrene, fluorene, triphenylene oxide, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, etc. A group formed by removing hydrogen from compounds consisting of isoxazole, quinoline, isoquinoline, quinoxaline, quinazoline, thiadiazole, phthalazine, tetrazolium, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimidazole, benzotriazole, benzoisothiazole, benzothiadiazole, purine, pyranone, coumarin, isocoumarin, chromone, dibenzofuran, dibenzothiophene, dibenzoselenophene, carbazole, or 2 to 7 of these linked together. Preferably, a group formed by removing hydrogen from compounds consisting of benzene, naphthalene, acenaphthene, acenaphthene, azulene, anthracene, phenylene oxide, pyrene, phenanthrene, fluorene, triphenylene oxide, carbazole, dibenzofuran, dibenzothiophene, or 2 to 5 of these linked together. More preferably, a group formed from benzene, biphenyl, or terphenyl. The terphenyl group can be linear or branched.

[0053] As Ar 1 and Ar2 Specific examples of an unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, an unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 3 of these aromatic rings, except that the number of linked aromatic groups is 2 to 3, and is related to the Ar 7 ~Ar 9 The situation described in the text is the same.

[0054] R 1 ~R 4 Each of the following is independently hydrogen, deuterium, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking two or three aromatic rings of such aromatic hydrocarbon groups and aromatic heterocyclic groups. Preferably, it is hydrogen, deuterium, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking two of such aromatic groups. More preferably, it is hydrogen, deuterium, or phenyl. Additionally, when R... 1 ~R 4 When it is an aromatic hydrocarbon group, it can react with R. 1 ~R 4 The bonded benzene ring or aromatic ring condenses to form a ring.

[0055] R is independently deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 3 aromatic rings selected from these aromatic hydrocarbon groups and aromatic heterocyclic groups. Preferably, it is hydrogen, deuterium, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 of these aromatic groups. More preferably, it is hydrogen, deuterium, or phenyl. Furthermore, when R is an aromatic hydrocarbon group, it can condense with the benzene ring or aromatic ring bonded to R to form a ring.

[0056] Regarding R 1 ~R 4 Specific examples where R is an unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, an unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or an unsubstituted linked aromatic group consisting of 2 to 3 aromatic rings of these aromatic groups, except that 2 to 3 aromatic rings of the aromatic hydrocarbon group or aromatic heterocyclic group are linked together with the Ar 7 ~Ar 9 The specific examples illustrated in are the same.

[0057] Regarding R 1 ~R 4Specific examples of aliphatic hydrocarbon groups having 1 to 10 carbon atoms include: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. These can be deuterated. Preferably, the deuterated alkyl group has 1 to 4 carbon atoms. Propyl and pentyl groups can be linearly linked or branched, while hexyl and heptyl groups can be linearly or cyclically linked or branched. Furthermore, these can be deuterated. Preferably, the deuterated linear or branched propyl group.

[0058] a~d represent the substitution numbers, where a and c independently represent integers from 1 to 4, and b and d represent integers from 1 to 2. When R 1 ~R 4 When hydrogen and deuterium are not included, it is preferable that a and c are integers of 1 to 2, and b and d are integers of 1; more preferably, a, b, c, and d are all integers of 1. When hydrogen and deuterium are included, it is preferable that a and c are integers of 3 to 4, and b and d are integers of 2; more preferably, a and c are integers of 4, and b and d are all integers of 2. Furthermore, the sum of a to d should preferably be 1 or more, preferably 4 or more. Moreover, R is preferred. 1 ~R 4 At least one exists as deuterium.

[0059] In the general formula (8), the two carbazole rings may be bonded at the 2, 3, or 4 positions, but are preferably bonded at the 3 position as shown in the general formula (9). In general formulas (8) and (9), the same symbols have the same meaning.

[0060] In the general formula (8) or the general formula (9), Ar 5 ~Ar 6 Each of the following is independently hydrogen, deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of the aromatic rings of these aromatic groups. Preferably, it is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 15 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 3 of the aromatic hydrocarbon groups. More preferably, it is a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted biphenyl group, or a substituted or unsubstituted terphenyl group.

[0061] Regarding Ar 5 ~Ar 6 Specific examples of unsubstituted aromatic hydrocarbon groups having 6 to 18 carbon atoms, unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or unsubstituted linked aromatic groups consisting of 2 to 5 of these aromatic groups, except that the number of linked aromatic groups is 2 to 5, and is related to Ar 7 ~Ar9 The situation is the same.

[0062] In general formula (8) or general formula (9), L is independently a single bond, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms. Preferably, it is a single bond, or a substituted or unsubstituted phenylene group. The linkage can be any of ortho-linking, meta-linking, or para-linking.

[0063] As a preferred form of the compound represented by the general formula (8), compounds represented by structures such as the general formula (9) can be listed.

[0064] R 5 and R 6 Each of the following groups independently represents hydrogen, deuterium, or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. Deuterium is preferred. A specific example of an aliphatic hydrocarbon group having 1 to 10 carbon atoms is related to R. 1 ~R 4 The situation is the same.

[0065] g~j and i~h represent the substitution numbers, where g and h represent integers from 1 to 4, and i and j represent integers from 1 to 3. When R 5 ~R 6 When hydrogen and deuterium are not included, it is preferable that g and h are integers of 1 to 2, and i and j are integers of 1; more preferably, g, h, i, and j are integers of 1. When hydrogen and deuterium are included, it is preferable that g and h are integers of 3 to 4, and i and j are integers of 2 to 3; more preferably, g and h are integers of 4, and i and j are integers of 3. Furthermore, the sum of g to j and i to h should preferably be 1 or more, preferably 4 or more. Moreover, R is preferred. 5 ~R 6 At least one exists as deuterium.

[0066] In this specification, linked aromatic groups refer to aromatic rings of two or more aromatic groups linked together by single bonds. These linked aromatic groups can be linear or branched. The linkage positions of the benzene rings can be ortho, meta, or para, but para or meta linkage is preferred. The aromatic groups can be aromatic hydrocarbon groups or aromatic heterocyclic groups, and the multiple aromatic groups can be the same or different.

[0067] In this specification, aromatic hydrocarbon groups, aromatic heterocyclic groups, or linked aromatic groups may each have substituents. When substituents are present, the substituents are preferably deuterium, halogen, cyano, triarylsilyl, aliphatic hydrocarbon group with 1 to 10 carbon atoms, alkenyl with 2 to 5 carbon atoms, alkoxy with 1 to 5 carbon atoms, or diarylamino with 12 to 44 carbon atoms. Here, when the substituent is an aliphatic hydrocarbon group with 1 to 10 carbon atoms, it can be linear, branched, or cyclic. Furthermore, when the triarylsilyl or diarylamino is a substituent for the aromatic hydrocarbon group, aromatic heterocyclic group, or linked aromatic group, silicon and carbon, or nitrogen and carbon, are bonded by a single bond, respectively. Furthermore, the number of substituents is preferably 0 to 5, and more preferably 0 to 2. Additionally, when calculating the number of carbon atoms in aromatic hydrocarbon groups and aromatic heterocyclic groups with substituents, the number of carbon atoms in the substituents is not included. However, it is preferable that the total number of carbons, including the number of carbons of the substituents, satisfies the range.

[0068] Specific examples of the substituents include: deuterium, cyano, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, neopentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, vinyl, propenyl, butenyl, pentenyl, methoxy, ethoxy, propoxy, butoxy, pentoxy, diphenylamino, naphthylphenylamino, dinaphthylamino, dianthrylamino, diphenoxyamino, dipyreneamino, etc. Preferably, the substituents include: deuterium, cyano, methyl, ethyl, tert-butyl, propyl, butyl, pentyl, neopentyl, hexyl, heptyl, or octyldiphenylamino, naphthylphenylamino, or dinaphthylamino.

[0069] The compounds represented by general formulas (1) to (7), and the compounds represented by general formulas (8) or (9), may contain deuterium or not. Furthermore, both the compounds represented by general formulas (1) to (7), and the compounds represented by general formulas (8) or (9) may contain deuterium or not. Moreover, only one of the compounds represented by general formulas (1) to (7), or the compounds represented by general formulas (8) or (9), may contain deuterium. When at least one of the compounds represented by general formulas (1) to (7), and the compounds represented by general formulas (8) or (9) is a deuterium-containing compound, the performance (luminous efficiency and lifetime) of the organic EL element is improved. Deuterium can be incorporated into R... 1 ~R 4 and R 5 and R 6 At least a portion of it is deuterium, and it is introduced into compounds represented by general formulas (1) to (7) or (8) and (9), or R is used to make 1 ~R 4 and R 5 and R6 Any of the following can be used as the aliphatic hydrocarbon group, the aromatic hydrocarbon group, the aromatic heterocyclic group, or the linked aromatic group, and the hydrogen contained in these groups can be deuterated. Preferably, deuterium is introduced into the compounds represented by general formulas (1) to (7), or the compounds represented by general formulas (8) or (9).

[0070] Furthermore, the unsubstituted aromatic hydrocarbon groups, unsubstituted aromatic heterocyclic groups, unsubstituted linked aromatic groups, substituents of these aromatic groups, or part or all of the hydrogen in the aliphatic hydrocarbon groups specifically exemplified may be deuterated. That is, part or all of the hydrogen in each of the compounds represented by general formulas (1) to (7) and the compounds represented by general formulas (8) or (9) may be deuterated. In addition, deuterated compounds include both cases containing a single compound and cases containing a mixture of two or more compounds. That is, if the deuteration rate is specifically described, a deuteration rate of 50% means that an average of half of the hydrogen in all hydrogens is replaced with deuterium, and the deuterated compound may be a single compound or a mixture of different deuteration rates. In this specification, deuteration rate and average deuteration rate have the same meaning.

[0071] When a portion of the hydrogen atoms in the compounds represented by general formulas (1) to (7) and (8) or (9) are deuterium, it is preferable that at least 20% of all hydrogen atoms in the compounds represented by general formulas (1) to (7) and (8) or (9) are deuterium, more preferably at least 40% deuterium, even more preferably at least 50% deuterium, and most preferably at least 70% deuterium.

[0072] The deuteration rate can be determined by mass analysis or proton nuclear magnetic resonance (NMR) spectrometry. For example, when determined by NMR spectrometry, the sample is first prepared by adding the compound and an internal standard to a deuterated solvent and dissolving them. The proton concentration [mol / g] of the compound in the sample is calculated based on the ratio of the integrated intensity of the internal standard to that of the compound. Next, the ratio of the proton concentration of the deuterated compound to that of its corresponding undeuterated compound is calculated and subtracted from 1, thereby calculating the deuteration rate of the deuterated compound. Alternatively, the deuteration rate of a partial structure can be calculated using the same steps based on the integrated intensity of the chemical shift originating from the partial structure in question.

[0073] The following are specific examples of compounds represented by general formulas (1) to (7), but are not limited to these exemplified compounds.

[0074] [Chemistry 4]

[0075]

[0076] [Chemistry 5]

[0077]

[0078] [Chemistry 6]

[0079]

[0080] [Chemistry 7]

[0081]

[0082] [Chemistry 8]

[0083]

[0084] [Chemistry 9]

[0085]

[0086] [Chemistry 10]

[0087]

[0088] [Chemistry 11-1]

[0089]

[0090] [Chemistry 11-2]

[0091]

[0092] [Chemistry 11-3]

[0093]

[0094] The following are specific examples of compounds represented by the general formulas (8) and (9), but are not limited to these exemplified compounds.

[0095] [Chemistry 12]

[0096]

[0097] [Chemistry 13]

[0098]

[0099] [Chemistry 14]

[0100]

[0101] [Chemistry 15]

[0102]

[0103] [Chemistry 16]

[0104]

[0105] [Chemistry 17]

[0106]

[0107] [Chemistry 18]

[0108]

[0109] The organic EL element of the present invention includes one or more light-emitting layers between opposing anodes and cathodes. The organic EL element is characterized in that at least one light-emitting layer comprises a first body represented by any one of general formulas (1) to (7) and a second body represented by general formula (8) or (9). The first and second bodies may be contained within the light-emitting layer or may be a mixed composition for forming the light-emitting layer. The mixed composition may contain a luminescent dopant or other host material. Methods for forming the light-emitting layer include: vapor deposition of two compounds from different evaporation sources; and pre-mixing two compounds to form a premixed composition, which is then vaporized from a single evaporation source for vapor deposition. The latter method, also known as premixed vapor deposition, provides organic EL elements with excellent performance and lifespan.

[0110] The proportion of the first and second components relative to their total weight is preferably 10 wt% or more and less than 80 wt%, more preferably 20 wt% or more and less than 70 wt%. When the first and second components are included in a mixed composition or a premixed composition, the proportion of the first and second components remains the same. Furthermore, in the case of mixed compositions and premixed compositions, it is ideal to maintain a constant evaporation ratio between the two components; therefore, it is preferable to set the difference in their evaporation temperatures, or the difference in their 50% weight reduction temperatures, to be within 20°C.

[0111] Next, the structure of the organic EL element of the present invention will be described with reference to the accompanying drawings, but the structure of the organic EL element of the present invention is not limited thereto.

[0112] Figure 1This is a cross-sectional view showing a typical organic EL element structure. 1 represents the substrate, 2 represents the anode, 3 represents the hole injection layer, 4 represents the hole transport layer, 5 represents the light-emitting layer, 6 represents the electron transport layer, and 7 represents the cathode. In the organic EL element of the present invention, an exciton blocking layer may be present adjacent to the light-emitting layer, and an electron blocking layer may also be present between the light-emitting layer and the hole injection layer. The exciton blocking layer may be inserted into either the anode side or the cathode side of the light-emitting layer, or simultaneously into both sides. In the organic EL element of the present invention, an anode, a light-emitting layer, and a cathode are required layers, but in addition to the required layers, a hole injection transport layer and an electron injection transport layer are preferably present, and furthermore, a hole blocking layer is preferably present between the light-emitting layer and the electron injection transport layer. Furthermore, the hole injection transport layer refers to either or both of the hole injection layer and the hole transport layer, and the electron injection transport layer refers to either or both of the electron injection layer and the electron transport layer.

[0113] It can also be used for Figure 1 In the opposite structure, where a cathode 7, an electron transport layer 6, a light-emitting layer 5, a hole transport layer 4, a hole injection layer 3, and an anode 2 are sequentially stacked on a substrate 1, layers can be added or omitted as needed.

[0114] -Substrate-

[0115] The organic EL element of the present invention is preferably supported on a substrate. The substrate is not particularly limited, as long as it is a substrate that has been used for organic EL elements before, such as a substrate containing glass, transparent plastic, quartz, etc.

[0116] -anode-

[0117] As the anode material in an organic electroluminescent (EL) element, materials containing metals, alloys, electrically conductive compounds, or mixtures thereof with a high work function (4 eV or higher) are preferably used. Specific examples of such electrode materials include metals such as Au, CuI, indium tin oxide (ITO), SnO2, and ZnO, which are conductive and transparent materials. Alternatively, amorphous materials such as IDIXO (In2O3-ZnO) that can be formed into transparent conductive films can also be used. The anode can be formed into a thin film using methods such as vapor deposition or sputtering, and a pattern of the desired shape can be formed using photolithography. Alternatively, when pattern precision is not critical (around 100 μm or higher), a pattern can be formed by separating the desired shape from the vapor deposition or sputtering of the electrode material. Alternatively, when using a coatable substance such as an organic conductive compound, wet film formation methods such as printing or coating can be used. When light is emitted from the anode, it is ideal to have a transmittance greater than 10%, and the sheet resistance of the anode is preferably less than several hundred Ω / □. The film thickness also depends on the material, and is typically selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

[0118] -cathode-

[0119] On the other hand, as cathode materials, materials comprising metals (electron-injecting metals), alloys, electrically conductive compounds, or mixtures thereof with low work functions (below 4 eV) can be used. Specific examples of such electrode materials include: sodium, sodium-potassium alloys, magnesium, lithium, magnesium / copper mixtures, magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / alumina (Al₂O₃) mixtures, indium, lithium / aluminum mixtures, rare earth metals, etc. Among these, in terms of electron injection performance and durability against oxidation, mixtures of electron-injecting metals and second metals that are more stable and have a larger work function than the first metal are suitable, such as magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / alumina mixtures, lithium / aluminum mixtures, aluminum, etc. Cathodes can be fabricated by forming thin films from these cathode materials using methods such as vapor deposition or sputtering. Furthermore, as a cathode, the sheet resistance is preferably several hundred Ω / □ or less, and the film thickness is typically selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. Furthermore, in order to allow the emitted light to pass through, if either the anode or cathode of the organic EL element is transparent or translucent, the luminous brightness will be increased, which is appropriate.

[0120] Furthermore, after forming the metal on the cathode with a film thickness of 1 nm to 20 nm, a conductive transparent material listed in the description of the anode is formed on it, thereby making a transparent or translucent cathode. By applying the method described above, an element in which both the anode and the cathode are transparent can be made.

[0121] -Emitting Layer-

[0122] The light-emitting layer is a layer that emits light after generating excitons by recombination of holes and electrons injected from the anode and cathode, respectively, and the light-emitting layer contains organic light-emitting dopant material and host material.

[0123] The main body includes the first main body and the second main body. Depending on the need, one or more other main body materials, such as known main body materials, may be combined and used. Preferably, these other main body materials are compounds that possess hole transport capability, electron transport capability, prevent the luminescence from becoming too long-wavelength, and have a high glass transition temperature.

[0124] Other main materials are known from most patent documents and can be selected from them. Specific examples of main materials, though not specifically limited, include: indole-carbazole derivatives recorded in WO2008 / 056746A1 or WO2008 / 146839A1, carbazole derivatives recorded in WO2009 / 086028A1 or WO2012 / 077520A1, CBP (N,N-biscarbazole biphenyl) derivatives, triazine derivatives recorded in WO2014 / 185595A1 or WO2018 / 021663A1, indobenzocarbazole derivatives recorded in WO2010 / 136109A1 or WO2011 / 000455A1, and dibenzofuran derivatives, triazole derivatives, indole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, and polyarylalkane derivatives recorded in WO2015 / 169412A1. Metal complexes representing various metal complexes, including pyrazoline derivatives, pyrazolineone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrene-anthracene derivatives, fluorene derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrene-amine compounds, aromatic dimethylene compounds, porphyrin compounds, anthraquinone dimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiamium dioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthalene and perylene, phthalocyanine derivatives, metal complexes of 8-hydroxyquinoline derivatives or metal phthalocyanines, metal complexes of benzoxazole or benzothiazole derivatives, polysilane compounds, poly(N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylidene derivatives, polyfluorene derivatives, and other polymer compounds.

[0125] The following are specific examples of the other main body materials, but are not limited to these.

[0126] [Chemistry 19]

[0127]

[0128] When using multiple substrates, each substrate can be deposited from different evaporation sources, or a premixed composition can be prepared by pre-mixing before evaporation, thereby allowing multiple substrates to be deposited simultaneously from one evaporation source.

[0129] Ideally, premixing methods should be those that can mix as uniformly as possible. Examples of such methods include pulverizing and mixing, heating and melting under reduced pressure or inert gas atmospheres such as nitrogen, or sublimation, but these methods are not the only ones that can be used.

[0130] The premixed composition may be in the form of powder, rod, film or granules.

[0131] As the organic light-emitting dopant material, phosphorescent dopant, fluorescent dopant, or thermally activated delayed fluorescence dopant are preferably examples.

[0132] As a phosphorescent dopant, it may contain an organometallic complex comprising at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Specifically, iridium complexes described in the Journal of the American Chemical Society (J. Am. Chem. Soc.) 2001, 123, 4304, JP2013-530515A, US2016 / 0049599A1, US2017 / 0069848A1, US2018 / 0282356A1, or US2019 / 0036043A1, or platinum complexes described in US2018 / 0013078A1 or KR2018 / 094482A, etc., may be used, but are not limited to these.

[0133] The phosphorescent dopant material may contain only one type or more types in the luminescent layer. The content of the phosphorescent dopant material is preferably 0.1 wt% to 30 wt% relative to the host material, and more preferably 1 wt% to 20 wt%.

[0134] There are no particular limitations on phosphorescent dopant materials; specifically, examples such as the following can be cited.

[0135] [Chemistry 20]

[0136]

[0137] [Chemistry 21]

[0138]

[0139] [Chemistry 22]

[0140]

[0141] As a fluorescent dopant, there are no particular limitations. Examples include: benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, styrene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalene dicarboximide derivatives, coumarin derivatives, condensed aromatic compounds, perinone derivatives, oxadiazole derivatives, oxazine derivatives, aldazine derivatives, pyrrolidine derivatives, cyclopentadiene derivatives, bis(styrene)anthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazopyridine derivatives, styrene-amine derivatives, diketopyrrolopyrrole derivatives, aromatic secondary methyl compounds, metal complexes of 8-hydroxyquinoline derivatives or metal complexes of pyrrole methylene derivatives, rare earth complexes, various metal complexes represented by transition metal complexes, polymer compounds such as polythiophene, polyphenylene, and polyphenylacetylene, and organosilanes, etc. Preferably, the derivatives include condensed aromatic derivatives, styryl derivatives, diketopyrrolopyrrole derivatives, oxazine derivatives, pyrrole methylene metal complexes, transition metal complexes, or lanthanide complexes. More preferably, the derivatives include naphthalene, pyrene, thionyl, triphenylene, benzo[c]phenanthrene, benzo[a]anthracene, pentanebenzene, perylene, fluoranthene, acenaphthene-fluoranthene, dibenzo[a,j]anthracene, dibenzo[a,h]anthracene, benzo[a]naphthalene, hexaphenylene, naphtho[2,1-f]isoquinoline, α-naphthaphenanthridine, phenanthridine, quinolino[6,5-f]quinoline, benzonaphtho[2,3-b]thiophene, etc. These may also have alkyl, aryl, aromatic heterocyclic groups, or diarylamino groups as substituents.

[0142] The fluorescent dopant material in the luminescent layer may contain only one type or two or more types. The preferred content of the fluorescent dopant material is 0.1 wt% to 20 wt% relative to the host material, and more preferably 1 wt% to 10 wt%.

[0143] There are no particular limitations on thermally activated delayed fluorescence dopants. Examples include: metal complexes such as tin complexes or copper complexes; indole-carbazole derivatives as described in WO2011 / 070963A1; cyanobenzene derivatives and carbazole derivatives as described in Nature 2012, 492, 234; and phenazine derivatives, oxadiazole derivatives, triazole derivatives, sulfone derivatives, phenoxazine derivatives, and acridine derivatives as described in Nature Photonics 2014, 8, 326.

[0144] There are no particular limitations on thermally activated delayed fluorescence dopants; specifically, examples such as the following can be cited.

[0145] [Chemistry 23]

[0146]

[0147] The thermally activated delayed fluorescence (TEF) dopant material may contain only one type or two or more types in the luminescent layer. Furthermore, the TEF dopant may be used in combination with phosphorescent or fluorescent dopant. The content of the TEF dopant material relative to the host material is preferably 0.1 wt% to 50 wt%, more preferably 1 wt% to 30 wt%.

[0148] -Injection Layer-

[0149] An injection layer is a layer placed between the electrode and the organic layer to reduce the driving voltage or increase the luminous brightness. There are hole injection layers and electron injection layers, which can exist between the anode and the luminescent layer or hole transport layer, and between the cathode and the luminescent layer or electron transport layer. The injection layer can be set as needed.

[0150] -hole blocking layer-

[0151] In a broad sense, a hole blocking layer functions as an electron transport layer. It includes hole-blocking materials that can transport electrons but have a significantly lower ability to transport holes. By transporting electrons and blocking holes, it can increase the recombination probability of electrons and holes in the light-emitting layer.

[0152] -Electron blocking layer-

[0153] In a broad sense, the electron blocking layer functions as a hole transport layer, increasing the probability of electrons and holes recombinating in the luminescent layer by transporting holes and blocking electrons.

[0154] Known electron blocking layer materials can be used as the electron blocking layer material, and hole transport layer materials described later can be used as needed. The thickness of the electron blocking layer is preferably 3 nm to 100 nm, more preferably 5 nm to 30 nm.

[0155] -Exciton blocking layer-

[0156] An exciton blocking layer is a layer used to prevent excitons generated by the recombination of holes and electrons in the light-emitting layer from diffusing into the charge transport layer. By inserting this layer, excitons can be efficiently sealed into the light-emitting layer, thereby improving the luminous efficiency of the device. In devices with two or more adjacent light-emitting layers, the exciton blocking layer can be inserted between two adjacent light-emitting layers.

[0157] Known exciton blocking layer materials can be used as the exciton blocking layer material. Examples include 1,3-dicarbazolylbenzene (mCP) or bis(2-methyl-8-hydroxyquinoline)-4-phenylphenolaluminum(III) (BAlq).

[0158] -Hole transport layer-

[0159] A hole transport layer consists of hole transport materials that have the function of transporting holes. A hole transport layer can be a single layer or multiple layers.

[0160] The hole transport material is any material that possesses either hole injection or transport or electron barrier properties, and can be either organic or inorganic. Any previously known compound can be selected for use in the hole transport layer. Examples of such hole transport materials include: porphyrin derivatives, arylamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrene-anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymeric oligomers, particularly thiophene oligomers. Porphyrin derivatives, arylamine derivatives, and styrene-anthracene derivatives are preferred, and arylamine derivatives are more preferred.

[0161] -Electron transport layer-

[0162] An electron transport layer consists of materials that can transport electrons, and can be a single layer or multiple layers.

[0163] As an electron transport material (and sometimes also a hole blocking material), it only needs to have the function of transferring electrons injected from the cathode to the light-emitting layer. Any previously known compound can be selected for use in the electron transport layer, such as: polycyclic aromatic derivatives of naphthalene, anthracene, phenanthroline, etc.; tris(8-hydroxyquinoline)aluminum(III) derivatives; phosphine oxide derivatives; nitro-substituted fluorene derivatives; diphenylquinone derivatives; thiamethane dioxide derivatives; carbodiimide; fluorenemethane derivatives; anthraquinone dimethane derivatives and anthrone derivatives; bipyridine derivatives; quinoline derivatives; oxadiazole derivatives; benzimidazole derivatives; benzothiazole derivatives; indolecarbazole derivatives, etc. Furthermore, polymers incorporating these materials into polymer chains or using these materials as the main chain of a polymer can also be used.

[0164] In the manufacturing method of the organic EL element of the present invention, the following steps are included: mixing a compound represented by general formulas (1) to (7) (first host) with a compound represented by general formulas (8) and (9) (second host) to prepare a premixed composition, and then evaporating the obtained premixed composition from a vapor deposition source to form a light-emitting layer by vapor deposition. By premixing the two host materials in this way, the performance of the organic EL element can be improved. As a mixing method, powder mixing or melt mixing can be used.

[0165] The premixed composition obtained by the premixing is preferably within 20°C of the difference between the 50% weight reduction temperature of the first and second base materials. Here, the 50% weight reduction temperature refers to the temperature at which a 50% weight reduction occurs when the temperature is increased from room temperature to 550°C at a rate of 10°C per minute under reduced pressure (1 Pa) by thermogravimetry-differential thermal analysis (TG-DTA). It is believed that vaporization caused by evaporation or sublimation is most intense near this temperature.

[0166] Example

[0167] The present invention will be described in more detail below through embodiments, but the present invention is not limited to these embodiments and can be implemented in various forms as long as it does not depart from its spirit.

[0168] As representative examples, synthetic examples of compounds 1-3, 1-9, 1-89, 1-90, 1-131, and 2-117 are shown. Other compounds are synthesized using a similar method. Regarding the deuteration rate, the ratio of the proton concentration of the deuterated compound obtained from proton NMR analysis to the proton concentration of its corresponding undeuterated compound is calculated, and then subtracted from 1 to obtain the deuteration rate of the deuterated compound.

[0169] Synthesis example 1

[0170] [Chemistry 24]

[0171]

[0172] 0.11 g of 60 wt% sodium hydride was added to 30 ml of N,N'-dimethylacetamide (DMAc), followed by 1.0 g (2.37 mmol) of compound (a) dissolved in DMAc, and the mixture was stirred for 30 minutes. Then, 1.06 g (3.08 mmol) of compound (b) was added, and the mixture was stirred for 4 hours. The reactants were separated and purified to obtain 0.69 g (0.95 mmol, 40% yield) of a yellow solid of compounds (1-3). (APCI-TOFMS, m / z 730 [M+H]) + ).

[0173] Synthesis example 2

[0174] [Chemistry 25]

[0175]

[0176] 0.11 g of 60 wt% sodium hydride was added to 30 ml of N,N'-dimethylacetamide (DMAc), followed by 1.0 g (2.37 mmol) of compound (c) dissolved in DMAc, and the mixture was stirred for 30 minutes. Then, 1.06 g (3.08 mmol) of compound (b) was added, and the mixture was stirred for 3 hours. The reactants were separated and purified to obtain 0.65 g (0.89 mmol, 38% yield) of a yellow solid containing compounds (1-9). (APCI-TOFMS, m / z 730 [M+H]) + ).

[0177] Synthesis example 3

[0178] [Chemistry 26]

[0179]

[0180] 0.5 g (0.69 mmol) of compounds (1-3) was mixed with 10 mL of deuterated benzene (C6D6) and 3.0 g (20 mmol) of trifluoromethanesulfonic acid (TfOH), and the mixture was heated and stirred at 50 °C for 3 hours under a nitrogen atmosphere. The reaction solution was then rapidly cooled in 20 mL of a deuterated aqueous solution of sodium carbonate (2.3 g), followed by separation and purification to obtain 0.26 g (0.35 mmol, yield 50%, deuteration rate 89%) of compounds (1-89) as deuterated derivatives. (APCI-TOFMS, m / z 761 [M+H]) + ).

[0181] The average deuteration rate of compounds 1-89 was determined by proton nuclear magnetic resonance spectrometry. The assay sample was prepared by dissolving compounds 1-89 (5.0 mg) and dimethyl sulfone (2.0 mg) as an internal standard in deuterated tetrahydrofuran (1.0 ml). The average proton concentration [mol / g] of compounds 1-89 in the assay sample was calculated based on the integral intensity ratio of the internal standard to that of compounds 1-89. Similarly, the average proton concentration [mol / g] of the non-deuterated compounds (compounds 1-3) of compounds 1-89 was also calculated. Then, the ratio of the proton concentration of compounds 1-89 to that of compounds 1-3 was calculated and subtracted from 1, thus yielding an average deuteration rate of 89% for compounds 1-89.

[0182] Synthesis example 4

[0183] [Chemistry 27]

[0184]

[0185] 0.5 g (0.69 mmol) of compounds (1-9) was mixed with 10 mL of deuterated benzene (C6D6) and 3.0 g (20 mmol) of trifluoromethanesulfonic acid (TfOH), and the mixture was heated and stirred at 50 °C for 3 hours under a nitrogen atmosphere. The reaction mixture was then rapidly cooled in 20 mL of a deuterated aqueous solution of sodium carbonate (2.3 g), followed by separation and purification to obtain 0.21 g (0.28 mmol, yield 40%, deuteration rate 87%) of compounds (1-90) as deuterated derivatives. (APCI-TOFMS, m / z 761 [M+H]) + ).

[0186] The average deuteration rate of compounds 1-90 was determined by proton nuclear magnetic resonance spectrometry. The assay sample was prepared by dissolving compounds 1-90 (5.0 mg) and dimethyl sulfone (2.0 mg) as an internal standard in deuterated tetrahydrofuran (1.0 ml). The average proton concentration [mol / g] of compounds 1-90 in the assay sample was calculated based on the integral intensity ratio of the internal standard to that of compounds 1-90. Similarly, the average proton concentration [mol / g] of the non-deuterated forms of compounds 1-90 (compounds 1-9) was also calculated. Next, the ratio of the proton concentration of compounds 1-90 to that of compounds 1-9 was calculated and subtracted from 1, thus yielding an average deuteration rate of 87% for compounds 1-90.

[0187] Synthesis example 5

[0188] [Chemistry 28-1]

[0189]

[0190] 8.3 g (14.8 mmol) of compound (2-2) was added to 160 mL of deuterated benzene (C6D6) and 10.0 g of deuterated trifluoromethane sulfonic acid (TfOD), and the mixture was heated and stirred at 50 °C for 6.5 h under a nitrogen atmosphere. The reaction solution was then rapidly cooled in 200 mL of a deuterated aqueous solution of sodium carbonate (7.4 g), and the mixture was separated and purified to obtain 2.0 g (3.40 mmol, yield 23%, deuteration 84%) of a white solid, compound (2-117). (APCI-TOFMS, m / z 589 [M+H]) + ).

[0191] The average deuteration rate of compound 2-117 was determined by proton nuclear magnetic resonance spectrometry. The assay sample was prepared by dissolving compound 2-117 (5.0 mg) and dimethyl sulfone (2.0 mg) as an internal standard in deuterated tetrahydrofuran (1.0 ml). The average proton concentration [mol / g] of compound 2-117 in the assay sample was calculated based on the ratio of the integrated intensity of the internal standard to that of compound 2-117. Similarly, the average proton concentration [mol / g] of the non-deuterated form of compound 2-117 (compound 2-2) was also calculated. The ratio of the proton concentration of compound 2-117 to that of compound 2-2 was then calculated and subtracted from 1, yielding an average deuteration rate of 84% for compound 2-117.

[0192] Synthesis example 6

[0193] [Chemistry 28-2]

[0194]

[0195] Add 0.11 g of 60 wt% sodium hydride to 30 ml of N,N'-dimethylacetamide (DMAc), then add 1.2 g (2.37 mmol) of the compound dissolved in DMAc (d), and stir for 30 minutes. Add 0.86 g (3.08 mmol) of the compound (e), and stir for 3 hours. Separate and purify the reaction product to obtain 1.08 g (1.42 mmol, yield 60%, deuteration 90%) of a yellow solid of compound (1-131). (APCI-TOFMS, m / z 762 [M+H]) + ).

[0196] The average deuteration rate of compounds 1-131 was determined by proton nuclear magnetic resonance spectrometry. The assay sample was prepared by dissolving compound 1-131 (5.0 mg) and dimethyl sulfone (2.0 mg) as an internal standard in deuterated tetrahydrofuran (1.0 ml). The average proton concentration [mol / g] of compound 1-131 in the assay sample was calculated based on the ratio of the integrated intensity of the internal standard to that of compound 1-131. Similarly, the average proton concentration [mol / g] of the non-deuterated form of compound 1-131 (compound 1-126) was calculated. Then, the ratio of the proton concentration of compound 1-131 to that of compound 1-126 was calculated and subtracted from 1, thus yielding an average deuteration rate of 90% for compound 1-131.

[0197] The following examples and comparative examples show the compounds used.

[0198] [Chemistry 29]

[0199]

[0200] The remaining example compounds and comparative example compounds were synthesized by performing the reaction in the same manner as in Synthetic Examples 1 to 2. Furthermore, the remaining example compounds and comparative example compounds, as deuterates, were synthesized by performing the reaction in the same manner as in Synthetic Examples 3 to 6. Additionally, the deuteration rates were determined for Example Compounds 1-94, 1-95, 2-220, 2-233, and 2-235, as described above. The results are shown in Table 1.

[0201] [Table 1]

[0202]

[0203] Example 1

[0204] On a glass substrate with an ITO-containing anode having a film thickness of 70 nm, vacuum evaporation was performed at a vacuum degree of 4.0 × 10⁻⁶. -5Pa was used to stack the thin films. First, HAT-CN was formed to a thickness of 25 nm as a hole injection layer on ITO. Next, Spiro-TPD was formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10 nm as an electron blocking layer. Next, compounds 1-3 as the host and Ir(ppy)3 as the light-emitting dopant were co-deposited from different evaporation sources to form a light-emitting layer to a thickness of 40 nm. At this time, co-deposition was performed under evaporation conditions with an Ir(ppy)3 concentration of 10 wt%. Next, ET-1 was formed to a thickness of 20 nm as an electron transport layer. Then, LiF was formed to a thickness of 1 nm as an electron injection layer on the electron transport layer. Finally, Al was formed to a thickness of 70 nm as a cathode on the electron injection layer, thereby fabricating an organic EL device.

[0205] Examples 2-11, Comparative Examples 1-3

[0206] In Example 1, the compounds shown in Table 2 were used as the main body, and the organic EL element was fabricated in the same manner as in Example 1.

[0207] The evaluation results of the fabricated organic EL elements are shown in Table 2. In the table, brightness, voltage, and power efficiency are expressed as a function of a drive current of 10 mA / cm². 2 The value at that time is the initial characteristic. LT97 has a drive current of 20 mA / cm². 2 The time it takes for the brightness to decay to 97% when the initial brightness is set to 100%, and this represents the lifetime characteristic. The main compound number is an additional number attached to the illustrative compound.

[0208] [Table 2]

[0209]

[0210] Example 12

[0211] On a glass substrate with an ITO-containing anode having a film thickness of 110 nm, a vacuum evaporation method was used to deposit the film at a vacuum degree of 4.0 × 10⁻⁶. -5Pa is used to stack various thin films. First, HAT-CN is formed to a thickness of 25 nm as a hole injection layer on ITO. Next, spiro-TPD is formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 is formed to a thickness of 5 nm as an electron blocking layer. Then, compounds 1-3 as the first host, compound 2-2 as the second host, and Ir(ppy)3 as the light-emitting dopant are co-deposited from different evaporation sources to form a light-emitting layer to a thickness of 35 nm. At this time, co-deposition is performed under evaporation conditions where the concentration of Ir(ppy)3 is 10 wt% and the weight ratio of the first host to the second host is 30:70. Next, ET-1 is formed to a thickness of 20 nm as an electron transport layer. Then, LiF is formed to a thickness of 1 nm on the electron transport layer as an electron injection layer. Finally, Al is formed to a thickness of 70 nm on the electron injection layer as a cathode, thereby fabricating an organic EL device.

[0212] Examples 13-42, Comparative Examples 4-12

[0213] The compounds shown in Tables 3-1 and 3-2 were used as the first and second main components, and were set to the weight ratios shown in Tables 3-1 and 3-2. Otherwise, organic EL elements were fabricated in the same manner as in Example 12.

[0214] Examples 43-46, Comparative Examples 13 and 14

[0215] The first and second bodies shown in Tables 3-1 and 3-2 were weighed in the weight ratios shown in Tables 3-1 and 3-2, and then ground and mixed in a mortar to obtain a premixed composition. The premixed composition was then vapor-deposited from a vapor deposition source, and an organic EL element was fabricated in the same manner as in Example 12.

[0216] The evaluation results of the fabricated organic EL elements are shown in Tables 3-1 and 3-2. In the tables, brightness, voltage, and power efficiency are expressed as a driving current of 10 mA / cm². 2 The value at that time is the initial characteristic. LT97 has a drive current of 20 mA / cm². 2 The time it takes for the brightness to decay to 97% when the initial brightness is set to 100% is also represented, indicating lifetime characteristics. The designations of the main compound, the first main compound, and the second main compound are additional designations used in the illustrated compounds, and the weight ratio is the first main compound : the second main compound.

[0217] [Table 3-1]

[0218]

[0219] [Table 3-2]

[0220]

[0221] Based on the results in Tables 3-1 and 3-2, it can be seen that the efficiency and lifespan of Examples 12, 14, and 16-24 are improved compared to Comparative Examples 4-6. Furthermore, the efficiency and lifespan are improved compared to Comparative Examples 7, 9-10, and 34, 37, and 39-42. Comparative Examples 13-14 and 43-46 also exhibit the same favorable characteristics as the aforementioned examples. The other examples also demonstrate good component characteristics compared to the comparative examples.

[0222] Table 4 describes the 50% weight reduction temperature (T) for compounds 1-1, 1-152, 2-101, 2-223, and A. 50 ).

[0223] [Table 4]

[0224]

[0225] Industrial availability

[0226] According to the present invention, by using a specified material for organic electric field light-emitting elements, it is possible to realize a practically useful organic EL element with low voltage, high efficiency and long lifespan.

[0227] Explanation of icon numbers

[0228] 1: Substrate

[0229] 2: Anode

[0230] 3: Hole injection layer

[0231] 4: Hole transport layer

[0232] 5: Emissive layer

[0233] 6: Electron transport layer

[0234] 7: Cathode

Claims

1. A material for an organic electric field light-emitting element, represented by any one of the following general formulas (1) to (7). [Chemistry 1-1] [Chemistry 1-2] (In the general formulas (1) to (7), Y is selected from O, S, N-Ar) 9 either of them, Ar 7 Ar 8 and Ar 9 Ar is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 7 of these aromatic groups. 7 ~Ar 9 At least one of them represents the expression represented by equation (1a). Ar 1 and Ar 2 Each of these groups is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 3 of these aromatic groups. This indicates the bond position with respect to general formulas (1) to (7). 1 ~R 4 Each of these groups is independently composed of hydrogen, deuterium, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 3 of these aromatic groups. When R 1 ~R 4 When the group is an aromatic hydrocarbon group, it can condense with the benzene ring to form a ring. X 1 ~X 3 Each is independently N, CH, or CR, and at least one is N. R is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 3 of these aromatic groups. a to d are the number of substitutions, where a and c are integers from 1 to 4, and b and d are integers from 1 to 2.

2. The material for organic electric field light-emitting elements according to claim 1, characterized in that, The R 1 ~R 4 Each is independently hydrogen, deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of two of these aromatic groups.

3. The material for organic electric field light-emitting elements according to claim 1, characterized in that, The X 1 ~X 3 All are N.

4. The material for organic electric field light-emitting elements according to claim 1, characterized in that, The Y is either O or S.

5. The material for organic electric field light-emitting elements according to claim 1, characterized in that, The Ar 1 and Ar 2 At least one of them is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by two linked aromatic rings of these.

6. An organic electric field light-emitting element comprising one or more organic layers between opposing anodes and cathodes, wherein at least one organic layer contains the material for an organic electric field light-emitting element as described in claim 1.

7. An organic electric field light-emitting element comprising one or more light-emitting layers between opposing anodes and cathodes, wherein at least one light-emitting layer contains a first host material selected from materials for organic electric field light-emitting elements as claimed in any one of claims 1 to 5, a second host material selected from compounds represented by the following general formula (8), and a light-emitting dopant material. [Chemistry 2] (Here, Ar) 5 and Ar 6 Each of the following groups independently represents hydrogen, deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group having 2 to 5 of these groups. L independently represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms. R 5 ~R 6 Each group independently represents hydrogen, deuterium, or an aliphatic hydrocarbon group with 1 to 10 carbon atoms. g to j represent the substitution number, where g and h are integers from 1 to 4, and i and j are integers from 1 to 3.

8. The organic electric field light-emitting element according to claim 7, characterized in that, The general formula (8) is represented by the following formula (9). [Chemistry 3] (Here, Ar) 5 Ar 6 L, R 5 R 6 g~j has the same meaning as general formula (8).

9. The organic electric field light-emitting element according to claim 7, wherein, The Ar 5 and Ar 6 Each can be independently a substituted or unsubstituted phenyl, a substituted or unsubstituted biphenyl, or a substituted or unsubstituted terphenyl.

10. The organic electric field light-emitting element according to claim 7, characterized in that, The R 5 and R 6 At least one of them is deuterium.

11. The organic electric field light-emitting element according to claim 10, characterized in that, The value of g to j is g + h + i + j = 14.

12. The organic electric field light-emitting element according to claim 7, characterized in that, The luminescent dopant material is an organometallic complex containing at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold.

13. The organic electric field light-emitting element according to claim 7, characterized in that, The luminescent dopant material is a thermally activated delayed fluorescence dopant material.

14. A mixed composition, characterized in that, It includes a compound represented by any one of the general formulas (1) to (7) as described in claim 1 as the first subject, and a compound represented by any one of the general formulas (8) as described in claim 6 or (9) as described in claim 8 as the second subject.

15. The mixture according to claim 14, characterized in that, The temperature difference between the first body and the second body when the weight is reduced by 50% is within 20°C.

16. A method for manufacturing an organic electric field light-emitting element, characterized in that, The process includes the following steps: when manufacturing the organic electric field light-emitting element as described in claim 7, the first body and the second body are premixed to form a premixed composition, and then a body material containing the premixed composition is vapor-deposited to form a light-emitting layer.

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