Organic electroluminescent element

Abstract

Provided is an organic EL element having a low voltage, high efficiency, and a long service life. Provided are: an organic EL element which contains a first host represented by general formula (1), a second host represented by general formula (2), and a light-emitting dopant material; a pre-mixture; and a method for producing the organic EL element. Ring F is represented by formula (1f), Ar1 and Ar2 are each independently a phenyl group or the like, Ar3 is a C6-30 aromatic hydrocarbon group or the like, and the average deuteration rate of Ar3 is 50% or more. Each R1 independently represents deuterium or the like, and the average deuterization rate of the indolocarbazole skeleton and all hydrogen contained in R1 is 50% or more. Ar5 and Ar6 are each independently a C6-30 aromatic hydrocarbon group or the like, and have an average deuteration rate of 30% or more. Each R2 independently represents deuterium or the like, and the average deuterization rate of all hydrogen contained in the dicarbazole and R2 is 50% or more. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to an organic electroluminescent element (hereinafter referred to as an organic EL element), and more particularly to an organic EL element including a specific mixed host material. Background Art

[0002] By applying voltage to the organic EL (electroluminescence) element, holes are injected from the anode into the light-emitting layer, and electrons are injected from the cathode into the light-emitting layer. In addition, in the light-emitting layer, the injected holes recombine with the electrons to generate excitons. At this time, according to the statistical law of electron spin, singlet excitons and triplet excitons are generated in a ratio of 1:3. Regarding fluorescent organic EL elements using light generated by singlet excitons, the limit of the internal quantum efficiency is considered to be 25%. On the other hand, it is known that phosphorescent organic EL elements using light generated by triplet excitons can increase the internal quantum efficiency to 100% when intersystem crossing is efficiently performed from singlet excitons.

[0003] Recently, a highly efficient organic EL element utilizing delayed fluorescence is being developed. For example, Patent Document 1 discloses an organic EL element utilizing a triplet-triplet fusion (TTF) mechanism, which is one of the mechanisms of delayed fluorescence. The TTF mechanism utilizes the phenomenon of generating singlet excitons by the collision of two triplet excitons, and is believed to theoretically increase the internal quantum efficiency to 40%. However, when compared with a phosphorescent organic EL element, the efficiency is low, and therefore further improvements in efficiency and low voltage characteristics are required.

[0004] In addition, Patent Document 2 discloses an organic EL element that utilizes the thermally activated delayed fluorescence (TADF) mechanism. The TADF mechanism utilizes the following phenomenon: in a material with a small energy difference between the singlet energy level and the triplet energy level, reverse intersystem crossing from triplet excitons to singlet excitons occurs; it is believed that the internal quantum efficiency can be increased to 100% in theory.

[0005] However, in any mechanism, there is room for improvement in efficiency and lifespan, and in addition, there is also demand for improvement in reducing the driving voltage.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent document 1: WO2010 / 134350

[0009] Patent Document 2: WO2011 / 070963

[0010] Patent Document 3: WO2008 / 056746

[0011] Patent Document 4: WO2018 / 198844

[0012] Patent document 5: US10333077B2

[0013] Patent document 6: JP5784621B2

[0014] Patent document 7: KR102054806B1

[0015] Patent Document 8: KR102283849B1

[0016] Patent document 9: KR20220013910A

[0017] Patent Document 10: KR102193015B1

[0018] Patent Document 3 discloses the use of an indolocarbazole compound as a host material for a light-emitting layer.

[0019] Patent Documents 4 and 5 disclose using an indolocarbazole compound and a biscarbazole compound as a mixed host material for a light-emitting layer.

[0020] Patent Documents 6 and 7 disclose the use of a deuterated indolocarbazole compound as a host material for a light-emitting layer.

[0021] Patent Documents 8 and 9 disclose using a deuterated biscarbazole compound as a host material for a light-emitting layer.

[0022] Patent Documents 7 and 10 disclose using a deuterated indolocarbazole compound and a biscarbazole compound as a mixed host material for a light-emitting layer.

[0023] However, none of them can be said to be sufficient, and further improvements are desired. Summary of the invention

[0024] Problems to be solved by the invention

[0025] Compared with liquid crystal displays, organic EL displays are thin and light, have high contrast, and can display high-speed animations. In addition, their design features such as curved and flexible surfaces are also highly valued, and they are widely used in display devices represented by mobile phones and televisions. However, in order to suppress battery consumption when used as portable terminals, further low voltage is required. In addition, as a light source, it is inferior to inorganic light-emitting diodes (LEDs) in terms of brightness or life, so it is required to improve efficiency or increase component life. In view of the above situation, the purpose of the present invention is to provide a practically useful organic EL element with low voltage, high efficiency, and long life characteristics.

[0026] Technical means of solving problems

[0027] The present inventors have conducted intensive studies and, as a result, have found that an organic electroluminescent device using a specific mixed host material in a light-emitting layer can solve the above-mentioned problems, thereby completing the present invention.

[0028] The present invention relates to an organic electric field light-emitting element, comprising one or more light-emitting layers between an anode and a cathode facing each other, wherein at least one light-emitting layer contains: a first host selected from a compound represented by the following general formula (1); a second host selected from a compound represented by the following general formula (2); and a light-emitting dopant material.

[0029] [Chemistry 1]

[0030]

[0031] [Chemistry 2]

[0032]

[0033] In the general formula (1), ring F is a heterocyclic ring represented by the formula (1f) which is condensed with two adjacent benzene rings at any positions. 1 and Ar 2 are each independently a substituted or unsubstituted phenyl group containing deuterium, or a substituted or unsubstituted biphenyl group containing deuterium.

[0034] Ar 3 It is a deuterated substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a deuterated substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a deuterated substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic groups, and the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different. 1Each of them is independently deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms and containing deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms and containing deuterium, or a substituted or unsubstituted linked aromatic group containing deuterium formed by linking 2 to 5 of these aromatic groups, and the aromatic hydrocarbon groups or aromatic heterocyclic groups when linked may be the same or different. a to c are the number of substitutions, a and c are integers of 0 to 4, and b is an integer of 0 to 2.

[0035] Among them, R 1 At least one of the following is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group which is partially or entirely substituted with deuterium in which two to five of these aromatic groups are linked, and the indolecarbazole skeleton and R as a substituent thereof are 1 The average deuteration rate of all hydrogen contained in is more than 50%. 3 Some or all of the hydrogen contained in Ar is replaced by deuterium. 3 The average deuteration rate of all hydrogen contained therein is above 50%.

[0036] In the general formula (2), Ar 5 and Ar 6 Each independently represents a deuterium-containing substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a deuterium-containing substituted or unsubstituted linked aromatic group in which two to five of these aromatic groups are linked, and the linked aromatic hydrocarbon groups may be the same or different.

[0037] R 2 Each of them is independently deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms and containing deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms and containing deuterium, or a substituted or unsubstituted linked aromatic group containing deuterium formed by linking 2 to 5 of these aromatic groups, and the aromatic hydrocarbon groups or aromatic heterocyclic groups when linked may be the same or different. d to g are the number of substitutions, d and g are integers of 0 to 4, and e and f are integers of 0 to 3.

[0038] Among them, R 2 At least one of the following is deuterium, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group which is partially or entirely substituted with deuterium in which two to five of these aromatic groups are linked, and the bicarbazole skeleton and R as the substituent are 2The average deuteration rate of all hydrogen contained in is 50% or more. 5 and Ar 6 A portion of the hydrogen contained in Ar is replaced by deuterium. 5 and Ar 6 The average deuteration rate of all hydrogen contained in the gas is more than 30%.

[0039] In the general formula (1), Ar 3 Preferably, it is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, a substituted or unsubstituted quaterphenyl group containing deuterium, a substituted or unsubstituted dibenzofuranyl group containing deuterium, or a substituted or unsubstituted dibenzothiophenyl group containing deuterium. Further, more preferably, it is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, or a substituted or unsubstituted quaterphenyl group containing deuterium. In the general formula (1), preferably, R 1 For deuterium.

[0040] Furthermore, in the general formula (1), Ar 3 The average deuteration rate of all hydrogen atoms contained in the indolecarbazole is preferably 70% or more. 1 The average deuteration rate of all hydrogen contained in the hydrogen is preferably 70% or more.

[0041] In the general formula (2), Ar 5 and Ar 6 Preferably, it is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, a substituted or unsubstituted dibenzofuranyl group containing deuterium, or a substituted or unsubstituted dibenzothiophenyl group containing deuterium, and more preferably, it is a substituted or unsubstituted phenyl group containing deuterium, or a substituted or unsubstituted biphenyl group containing deuterium. In the general formula (2), preferably, R2 is deuterium.

[0042] Furthermore, in the general formula (2), Ar 5 and Ar 6 The average deuteration rate of all hydrogen contained in the mixture is preferably 50% or more.

[0043] The organic electric field light-emitting element of the present invention is an organic electric field light-emitting element comprising the following light-emitting layer, that is, the light-emitting layer has a mixed host comprising two compounds and a dopant (luminescent dopant material). Wherein, as the mixed host, the ratio of the compound represented by the general formula (1) to the total of the compound represented by the general formula (1) and the compound represented by the general formula (2) is preferably 10wt% or more and less than 80wt%, more preferably 30wt% or more and less than 80wt%. In addition, it is more preferred that the luminescent dopant material is an organic metal complex comprising at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold, or is a thermally activated delayed fluorescence dopant.

[0044] The present invention relates to a premixture, comprising a first host and a second host, for forming a light-emitting layer in an organic electric field light-emitting element, wherein the organic electric field light-emitting element includes the light-emitting layer containing a host and a light-emitting dopant material between an anode and a cathode facing each other, wherein the premixture is characterized in that the first host is selected from the compound represented by the general formula (1), and the second host is selected from the compound represented by the general formula (2). In the premixture, the preferred forms of the compound represented by the general formula (1) and the compound represented by the general formula (2) and the preferred mixing ratio of these compounds are also the same as the compounds configured in the organic electric field light-emitting element. In addition, when manufacturing the organic electric field light-emitting element, it is preferred to have the following steps: after mixing the first host represented by the general formula (1) and the second host represented by the general formula (2) to form a premixture, the host material containing the premixture is evaporated to form a light-emitting layer.

[0045] In the method for manufacturing the organic electroluminescent element, the difference between the 50% weight reduction temperatures of the first body and the second body is preferably within 20°C.

[0046] Effects of the Invention

[0047] According to the present invention, by mixing a first host having a nitrogen-containing six-membered ring and a phenyl or biphenyl group in an indole carbazole and further substituted with deuterium, and a deuterium-substituted biscarbazole compound as a second host, an organic EL element having low voltage, high efficiency and long life can be obtained. In addition, by mixing the first host with the previous second host to prepare a premix, and then using the host material containing the premix, an organic EL element with high brightness, high efficiency and long life can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0049] The first host material contained in the light-emitting layer of the organic EL device of the present invention is represented by the above-mentioned general formula (1).

[0050] In the general formula (1), ring F is a heterocyclic ring represented by the formula (1f) which is condensed with two adjacent benzene rings at any positions. 1 and Ar 2 Each of the above is independently a substituted or unsubstituted phenyl containing deuterium, or a substituted or unsubstituted biphenyl containing deuterium, preferably an unsubstituted phenyl or an unsubstituted biphenyl. Here, the so-called substitution containing deuterium includes two cases: the case where only the basic skeleton has a substituent, and the case where the hydrogen contained in the basic skeleton and its substituent is replaced by deuterium. For example, the so-called substituted phenyl containing deuterium includes two cases: the case where the phenyl as the basic skeleton has a substituent, and the case where the hydrogen contained in the phenyl and the substituent possessed by the phenyl is replaced by deuterium.

[0051] Ar 3 It is a deuterium-containing substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a deuterium-containing substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a deuterium-containing substituted or unsubstituted linked aromatic group in which two to five of these aromatic groups are linked, and the aromatic hydrocarbon groups or aromatic heterocyclic groups when linked may be the same or different. In addition, preferred are deuterium-containing substituted or unsubstituted phenyl, deuterium-containing substituted or unsubstituted biphenyl, deuterium-containing substituted or unsubstituted terphenyl, deuterium-containing substituted or unsubstituted quaterphenyl, deuterium-containing substituted or unsubstituted dibenzofuranyl, or deuterium-containing substituted or unsubstituted dibenzothiophenyl, and more preferred are deuterium-containing substituted or unsubstituted phenyl, deuterium-containing substituted or unsubstituted biphenyl, deuterium-containing substituted or unsubstituted terphenyl, or deuterium-containing substituted or unsubstituted quaterphenyl.

[0052] As Ar 3 Specific examples of an unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, an unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group in which two to five of these aromatic groups are linked include: benzene, naphthalene, dihydroacenaphthene, acenaphthene, azulene, anthracene, Pyrene, phenanthrene, fluorene, triphenylene, benzo[a]anthracene, tetracene, pentacene, hexacene, coronene, heptacene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, quinoline, isoquinoline, quinoxaline, quinazoline, thiadiazole, phthalazine, tetrazole, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimidazole, benzotriazole, benzisothiazole, benzothiadiazole, purine, pyrone, coumarin, isocoumarin, chromone, dibenzofuran, dibenzothiophene, dibenzoselenophene, carbazole, or a group formed by removing one hydrogen atom from a compound in which 2 to 5 of these are linked together. Preferably, it is a group formed by removing one hydrogen from benzene, dibenzofuran, dibenzothiophene, carbazole, or a compound composed of 2 to 5 of these groups linked together, more preferably a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a dibenzofuranyl group, or a dibenzothiophene group, and further preferably a quaterphenyl group. The terphenyl group and the quaterphenyl group may be linked in a straight chain or may be branched.

[0053] R 1 Each independently represents deuterium, a substituted or unsubstituted aromatic hydrocarbon group containing deuterium and having 6 to 10 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group containing deuterium and having 3 to 12 carbon atoms, or a substituted or unsubstituted linked aromatic group containing deuterium in which two to five of these aromatic groups are linked, and the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different. Preferably R 1 is deuterium, and preferably at least one R 1 It is the aromatic hydrocarbon group, the aromatic heterocyclic group, or the linked aromatic group.

[0054] As R 1Specific examples of the unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms, the unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms, or the linked aromatic group in which two to five of these aromatic rings are linked include: a group formed by removing one hydrogen atom from benzene, naphthalene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, quinoline, isoquinoline, quinoxaline, quinazoline, thiadiazole, phthalazine, tetrazole, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimidazole, benzotriazole, benzisothiazole, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophene, carbazole, or a compound in which two to five of these are linked. Preferably, it is a group formed by removing one hydrogen atom from benzene, dibenzofuran, dibenzothiophene, carbazole, or a compound composed of 2 to 5 of these groups. More preferably, it is a group formed by removing one hydrogen atom from benzene, dibenzofuran, dibenzothiophene, carbazole, or a compound composed of 2 to 3 of these groups. Still more preferably, it is a group formed by removing one hydrogen atom from benzene, carbazole, or a compound composed of 2 to 3 of these groups.

[0055] In the general formula (1), Ar 1 and Ar 2 Part or all of may be deuterated. Preferably Ar 1 and Ar 2 The average deuteration rate of R1 is 0%. In the general formula (1), at least one of R1 is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic rings which is partially or entirely substituted with deuterium, and the average deuteration rate of all hydrogen contained in the indolecarbazole skeleton and R1 as its substituent is 50% or more, preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. In addition, in the general formula (1), Ar 3 Some or all of the hydrogen contained in Ar is replaced by deuterium. 3 The average deuteration rate of all hydrogen contained in is 50% or more, preferably 70% or more, and more preferably 80% or more. Furthermore, the average deuteration rate of all hydrogen contained in the compound represented by the general formula (1) as a whole is preferably 30% or more, more preferably 40% or more, and more preferably 50% or more. The deuterated substance represented by the general formula (1) includes two cases: a case where it contains a single compound represented by the general formula (1) and a case where it contains a mixture of two or more compounds represented by the general formula (1). That is, for the average deuteration rate, if Ar is used as 3 Taking the example of Ar3 When the average deuteration rate of hydrogen on Ar is 50%, 3 On average, N / 2 of the N hydrogen atoms are replaced by deuterium. The deuterated compound represented by the general formula (1) may be a single compound or a mixture of compounds with different deuteration rates.

[0056] The average deuteration rate can be obtained by mass spectrometry or proton nuclear magnetic resonance spectroscopy. For example, in the case of obtaining by proton nuclear magnetic resonance spectroscopy, first, the sample is prepared by adding the compound and the internal standard substance to the deuterated solvent and dissolving it, and the proton concentration [mol / g] of the compound contained in the sample is calculated according to the integrated intensity ratio of the internal standard substance and the compound source. Next, the ratio of the proton concentration of the deuterated compound and the proton concentration of the corresponding undeuterated compound is calculated, and subtracted from 1, so that the average deuteration rate of the deuterated compound can be calculated. In addition, the average deuteration rate of the partial structure can be calculated according to the integrated intensity of the chemical shift of the partial structure as the object, according to the same process.

[0057] The second host material contained in the light-emitting layer of the organic EL device of the present invention is represented by the above-mentioned general formula (2).

[0058] In the general formula (2), Ar 5 and Ar 6 Each independently represents a deuterium-containing substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a deuterium-containing substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic groups, and the linked aromatic hydrocarbon groups may be the same or different. 5 and Ar 6 Each of them is independently a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, a substituted or unsubstituted dibenzofuranyl group containing deuterium, or a substituted or unsubstituted dibenzothienyl group containing deuterium, and more preferably a substituted or unsubstituted phenyl group containing deuterium, or a substituted or unsubstituted biphenyl group containing deuterium.

[0059] Ar 5 and Ar 6 Specific examples of unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms and unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms are the same as Ar 3 The same situation.

[0060] R 2Each independently represents deuterium, a substituted or unsubstituted aromatic hydrocarbon group containing deuterium and having 6 to 10 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group containing deuterium and having 3 to 12 carbon atoms, or a substituted or unsubstituted linked aromatic group containing deuterium in which two to five of these aromatic groups are linked, and the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different. Preferably R 2 For deuterium.

[0061] R 2 Specific examples of an unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms, an unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms, or a linked aromatic group in which two to five of these aromatic groups are linked together are as follows: 1 The same is true for the case of . Preferably, it is a group generated by extracting one hydrogen from benzene, dibenzofuran, dibenzothiophene, carbazole, or a compound composed of 2 to 5 of these, and more preferably, it is a group generated by extracting one hydrogen from benzene, dibenzofuran, dibenzothiophene, carbazole, or a compound composed of 2 to 3 of these.

[0062] In the general formula (2), R 2 At least one of the following is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group which is partially or entirely substituted with deuterium in which two to five of these aromatic groups are linked, and the bicarbazole skeleton and R as the substituent are 2 The average deuteration rate of all hydrogen contained in is 50% or more, preferably 70% or more. 5 and Ar 6 Some or all of the hydrogen contained in Ar is replaced by deuterium. 5 and Ar 6 The average deuteration rate of all hydrogen contained in is 30% or more, preferably 50% or more. Furthermore, the average deuteration rate of all hydrogen contained in the compound represented by the general formula (2) as a whole is preferably 30% or more, more preferably 50% or more. Here, the average deuteration rate and its calculation method are the same as those in the general formula (1).

[0063] In this specification, a linked aromatic group refers to an aromatic group formed by linking two or more aromatic groups by a single bond. These linked aromatic groups may be straight-chain or branched. The linking position when the benzene rings are linked to each other may be any one of the ortho position, meta position, or para position. The aromatic group may be an aromatic hydrocarbon group or an aromatic heterocyclic group, and the multiple aromatic groups may be the same or different.

[0064] In the present specification, the aromatic hydrocarbon group, the aromatic heterocyclic group, or the linked aromatic group may have a substituent. When having a substituent, the substituent is preferably deuterium, halogen, cyano, triarylsilyl, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a diarylamino group having 12 to 44 carbon atoms. Here, when the substituent is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, it may be straight-chain, branched, or cyclic. In addition, when the triarylsilyl group or the diarylamino group replaces the aromatic hydrocarbon group, the aromatic heterocyclic group, or the linked aromatic group, silicon and carbon, or nitrogen and carbon are bonded to a single bond, respectively.

[0065] Specific examples of the substituent 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, pentyloxy, diphenylamino, naphthylphenylamino, dinaphthylamino, dianthrylamino, diphenanthrylamino, dipyrenylamino, etc. Preferably, deuterium, cyano, methyl, ethyl, tert-butyl, propyl, butyl, pentyl, neopentyl, hexyl, heptyl, or octyldiphenylamino, naphthylphenylamino, or dinaphthylamino.

[0066] The specific examples of the compounds represented by the general formula (1) are shown below, but are not limited to these exemplified compounds. In addition, in the following structural formula, the substitution number of l, m, n, o, p, q, r, s, t, etc. of the substituted deuterium (D) refers to an average number and varies according to the deuteration rate (D rate).

[0067] [Chemistry 3-1]

[0068]

[0069] [Chemistry 3-2]

[0070]

[0071] [Chemistry 3-3]

[0072]

[0073] [Chemistry 3-4]

[0074]

[0075] [Chemistry 3-5]

[0076]

[0077] [Chemistry 3-6]

[0078]

[0079] [Chemistry 3-7]

[0080]

[0081] [Chemistry 3-8]

[0082]

[0083] [Chemistry 3-9]

[0084]

[0085] [Chemistry 3-10]

[0086]

[0087] [Chemistry 4-1]

[0088]

[0089] [Chemistry 4-2]

[0090]

[0091] [Chemistry 4-3]

[0092]

[0093] [Chemistry 4-4]

[0094]

[0095] [Chemistry 4-5]

[0096]

[0097] [Chemistry 4-6]

[0098]

[0099] [Chemistry 4-7]

[0100]

[0101] [Chemistry 4-8]

[0102]

[0103] [Chemistry 4-9]

[0104]

[0105] [Chemistry 4-10]

[0106]

[0107] [Chemistry 5-1]

[0108]

[0109] [Chemistry 5-2]

[0110]

[0111] [Chemistry 5-3]

[0112]

[0113] [Chemistry 5-4]

[0114]

[0115] [Chemistry 5-5]

[0116]

[0117] [Chemistry 5-6]

[0118]

[0119] [Chemistry 5-7]

[0120]

[0121] [Chemistry 5-8]

[0122]

[0123] [Chemistry 5-9]

[0124]

[0125] [Chemistry 5-10]

[0126]

[0127] [Chemistry 6-1]

[0128]

[0129] [Chemistry 6-2]

[0130]

[0131] [Chemistry 6-3]

[0132]

[0133] [Chemistry 6-4]

[0134]

[0135] [Chemistry 6-5]

[0136]

[0137] [Chemistry 6-6]

[0138]

[0139] [Chemistry 6-7]

[0140]

[0141] [Chemistry 6-8]

[0142]

[0143] [Chemistry 6-9]

[0144]

[0145] [Chemistry 6-10]

[0146]

[0147] [Chemistry 6-11]

[0148]

[0149] [Chemistry 6-12]

[0150]

[0151] [Chemistry 6-13]

[0152]

[0153] Specific examples of compounds represented by the general formula (2) are shown below, but are not limited to these exemplified compounds. In addition, in the following structural formula, the number of substitutions such as l', m', n', o', p', q', r', s', t', etc. of the substituted deuterium (D) refers to an average number and varies according to the deuteration rate (D rate).

[0154] [Chemistry 7]

[0155]

[0156] [Chemistry 8]

[0157]

[0158] [Chemistry 9]

[0159]

[0160] [Chemistry 10]

[0161]

[0162] [Chemistry 11]

[0163]

[0164] [Chemistry 12]

[0165]

[0166] [Chemistry 13]

[0167]

[0168] [Chemistry 14]

[0169]

[0170] [Chemistry 15]

[0171]

[0172] The host material for an organic EL device of the present invention is suitably used as a host material for a light-emitting layer.

[0173] Next, the structure of the organic EL element of the present invention will be described with reference to the drawings, but the structure of the organic EL element of the present invention is not limited thereto.

[0174] Figure 1 It is a cross-sectional view showing a structural example of a general organic EL element used in the present invention, 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents a light-emitting layer, 6 represents an electron transport layer, and 7 represents a cathode. In the organic EL element of the present invention, an exciton blocking layer may be adjacent to the light-emitting layer, and an electron blocking layer may also be provided 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, and may also be inserted into both sides at the same time. In the organic EL element of the present invention, an anode, a light-emitting layer, and a cathode are provided as necessary layers, but in addition to the necessary layers, a hole injection transport layer and an electron injection transport layer may also be provided, and a hole blocking layer may also be provided between the light-emitting layer and the electron injection transport layer. In addition, a hole injection transport layer refers to either or both of a hole injection layer and a hole transport layer, and an electron injection transport layer refers to either or both of an electron injection layer and an electron transport layer.

[0175] It can also be used with Figure 1In the opposite structure, that is, the cathode 7, the electron transport layer 6, the light emitting layer 5, the hole transport layer 4, the hole injection layer 3, and the anode 2 are sequentially stacked on the substrate 1, in which case the layers can be added or omitted as needed.

[0176] -Substrate-

[0177] 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 conventionally used for organic EL elements, and for example, a substrate made of glass, transparent plastic, quartz, etc. can be used.

[0178] -anode-

[0179] As the anode material in the organic EL element, a material containing a metal, alloy, electrically conductive compound or a mixture of these with a large work function (4 eV or more) can be preferably used. Specific examples of such electrode materials include: metals such as Au; conductive transparent materials such as CuI, indium tin oxide (ITO), SnO2, and ZnO. In addition, amorphous materials such as IDIXO (In2O3-ZnO) that can be made into transparent conductive films can also be used. The anode can be formed into a thin film by methods such as evaporation or sputtering, and a pattern of the desired shape can be formed by photolithography. Or, when the pattern accuracy is not very required (about 100 μm or more), a mask of the desired shape can be used to form a pattern during the evaporation or sputtering of the electrode material. Alternatively, when using a coatable substance such as an organic conductive compound, a wet film forming method such as printing or coating can also be used. When light is taken out from the anode, the transmittance is preferably greater than 10%, and the sheet resistance of the anode is preferably less than several hundred Ω / Y. The film thickness also depends on the material, and is usually selected in the range of 10nm to 1000nm, preferably 10nm to 200nm.

[0180] -cathode-

[0181] On the other hand, as a cathode material, a material containing a metal (electron injecting metal) with a small work function (less than 4 eV), an alloy, an electrically conductive compound, or a mixture of these 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 / aluminum oxide (Al2O3) mixtures, indium, lithium / aluminum mixtures, rare earth metals, etc. Among these, in terms of electron injectability and durability to oxidation, etc., a mixture of an electron injecting metal and a second metal that is a metal with a larger work function value than the metal and stable, such as a magnesium / silver mixture, a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide mixture, a lithium / aluminum mixture, aluminum, etc. is suitable. The cathode can be made as follows: these cathode materials are formed into a thin film by a method such as evaporation or sputtering. In addition, as a cathode, the sheet resistance is preferably less than several hundred Ω / Υ, and the film thickness is usually selected in the range of 10nm to 5μm, preferably 50nm to 200nm. Furthermore, in order to transmit the emitted light, it is preferable that either the anode or cathode of the organic EL element is transparent or semi-transparent, because the emission brightness is improved.

[0182] In addition, after the metal is formed on the cathode with a film thickness of 1nm to 20nm, the conductive transparent material listed in the description of the anode is formed thereon, thereby making a transparent or translucent cathode. By applying the method, an element in which both the anode and the cathode are transparent can be made.

[0183] -Luminous layer-

[0184] The light-emitting layer is a layer that emits light after excitons are generated by recombination of holes and electrons injected from the anode and the cathode, respectively, and the light-emitting layer may contain an organic light-emitting dopant material and a host material.

[0185] It is preferred that the compound represented by the general formula (1) is used as the first host in the host, and the compound represented by the general formula (2) is used as the second host. The first host material of the compound represented by the general formula (1) can be one or two or more different compounds. Similarly, the second host material of the compound represented by the general formula (2) can be one or two or more different compounds. Regarding the mixing ratio (weight ratio) of the first host and the second host, the proportion of the first host is preferably 10wt% or more and less than 80wt%, preferably 30wt% or more and less than 80wt% relative to the total of the first host and the second host. If necessary, one or more other known host materials can also be used in combination, but the amount used is preferably set to 50wt% or less relative to the total of the first host and the second host, preferably set to 25wt% or less. As other known host materials, it is preferred that the compound has hole transport ability, electron transport ability, prevents the long wavelength of light emission, and has a high glass transition temperature.

[0186] Other known host materials are known from a number of patent documents and the like, and can be selected from these. Specific examples of the host material are not particularly limited, and examples thereof include indolecarbazole derivatives described in WO2008 / 056746A1 or WO2008 / 146839A1, carbazole derivatives described in WO2009 / 086028A1 or WO2012 / 077520A1, CBP (N,N-biscarbazolylbiphenyl) derivatives, triazine derivatives described in WO2014 / 185595A1 or WO2018 / 021663A1, indenocarbazole derivatives described in WO2010 / 136109A1 or WO2011 / 000455A1, dibenzofuran derivatives described in WO2015 / 169412A1, triazole derivatives, indole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, and polyarylalkane derivatives. , pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styryl anthracene derivatives, fluorenone derivatives, hydrazone derivatives, distyrene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylene compounds, porphyrin compounds, anthraquinone dimethane derivatives, anthrone derivatives, diphenylquinone derivatives, dioxythiopyran derivatives, naphthyl perylene and other heterocyclic tetracarboxylic anhydrides, phthalocyanine derivatives, metal complexes of 8-hydroxyquinoline derivatives or metal phthalocyanines, various metal complexes represented by metal complexes of benzoxazole or benzothiazole derivatives, polysilane compounds, poly(N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, polythiophene derivatives, polyphenylene derivatives, polyparaphenylene vinylene derivatives, polyfluorene derivatives and other polymer compounds, etc.

[0187] Specific examples of the other known host materials are shown below, but the present invention is not limited to these. In addition, for other known host materials, part or all of the hydrogen may be deuterated.

[0188] [Chemistry 16]

[0189]

[0190] Preferred examples of the organic light-emitting dopant material include phosphorescent dopants, fluorescent dopants, and thermally activated delayed fluorescent dopants.

[0191] As a phosphorescent dopant, an organic metal complex comprising at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold may be contained. Specifically, iridium complexes described in "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 suitably used, but are not limited to these.

[0192] The phosphorescent dopant material may be contained in the light emitting layer in one kind or in two or more kinds. The content of the phosphorescent dopant material is preferably 0.1 wt% to 30 wt%, more preferably 1 wt% to 20 wt%, based on the host material.

[0193] The phosphorescent dopant material is not particularly limited, and specific examples include the following.

[0194] [Chemistry 17]

[0195]

[0196] [Chemistry 18]

[0197]

[0198] [Chemistry 19]

[0199]

[0200] The fluorescent dopant is not particularly limited, and examples thereof include benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, condensed aromatic compounds, perinone derivatives, oxadiazole derivatives, oxazine derivatives, aldazine derivatives, pyrrolidine derivatives, cyclopentadiene derivatives, distyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, styrylamine derivatives, diketopyrrolopyrrole derivatives, aromatic dimethyl compounds, metal complexes of 8-hydroxyquinoline derivatives or metal complexes of pyrromethene derivatives, rare earth complexes, various metal complexes represented by transition metal complexes, polymer compounds such as polythiophene, polyphenylene, and polyphenylene vinylene, and organosilane derivatives. Preferred examples include condensed aromatic derivatives, styryl derivatives, diketopyrrolopyrrole derivatives, oxazine derivatives, pyrromethene metal complexes, transition metal complexes, or lanthanide complexes, and more preferred examples include naphthalene, pyrene, Triphenylene, benzo[c]phenanthrene, benzo[a]anthracene, pentacene, perylene, fluoranthene, acenaphthofluoranthene, dibenzo[a,j]anthracene, dibenzo[a,h]anthracene, benzo[a]naphthalene, hexacene, naphtho[2,1-f]isoquinoline, α-naphthaphenanthridine, phenanthrooxazole, quinolino[6,5-f]quinoline, benzonaphtho[2,3-b]thiophene, etc. These may have an alkyl group, an aryl group, an aromatic heterocyclic group, or a diarylamino group as a substituent.

[0201] The light-emitting layer may contain only one type of fluorescent dopant material or two or more types of fluorescent dopant materials. The content of the fluorescent dopant material is preferably 0.1 wt% to 20 wt%, more preferably 1 wt% to 10 wt%, based on the host material.

[0202] The thermally activated delayed fluorescence dopant is not particularly limited, and examples thereof include metal complexes such as tin complexes or copper complexes, or indolecarbazole derivatives described in WO2011 / 070963A1, cyanobenzene derivatives and carbazole derivatives described in Nature 2012, 492, 234, phenazine derivatives, oxadiazole derivatives, triazole derivatives, sulfone derivatives, phenoxazine derivatives, and acridine derivatives described in Nature Photonics 2014, 8, 326.

[0203] The thermally activated delayed fluorescence dopant material is not particularly limited, and specific examples thereof include the following.

[0204] [Chemistry 20]

[0205]

[0206] The thermally activated delayed fluorescent dopant material may contain only one or more than one in the light-emitting layer. In addition, the thermally activated delayed fluorescent dopant may be mixed with a phosphorescent dopant or a fluorescent dopant. The content of the thermally activated delayed fluorescent dopant material is preferably 0.1wt% to 50wt%, more preferably 1wt% to 30wt% relative to the host material.

[0207] -Injection layer-

[0208] The so-called injection layer is a layer provided between the electrode and the organic layer in order to reduce the driving voltage or increase the luminous brightness. There are hole injection layer and electron injection layer, which can exist between the anode and the light-emitting layer or the hole transport layer, and between the cathode and the light-emitting layer or the electron transport layer. The injection layer can be provided as needed.

[0209] -Hole blocking layer-

[0210] The so-called hole blocking layer, in a broad sense, has the function of an electron transport layer and includes a hole blocking material that has the function of transporting electrons but has a significantly lower ability to transport holes. It can increase the probability of recombination between electrons and holes in the light-emitting layer by transporting electrons and blocking holes.

[0211] -Electron blocking layer-

[0212] The electron blocking layer, in a broad sense, has the function of a hole transporting layer, and can increase the probability of recombination between electrons and holes in the light-emitting layer by transporting holes and blocking electrons.

[0213] As the material of the electron blocking layer, a known electron blocking layer material can be used, and the material of the hole transport layer described later can be used as necessary. The film thickness of the electron blocking layer is preferably 3 nm to 100 nm, more preferably 5 nm to 30 nm.

[0214] - Exciton blocking layer -

[0215] The so-called exciton blocking layer is a layer used to block the excitons generated by the recombination of holes and electrons in the light-emitting layer from diffusing to the charge transport layer. By inserting this layer, the excitons can be efficiently sealed in the light-emitting layer, which can improve the luminous efficiency of the element. In an element with two or more light-emitting layers adjacent to each other, the exciton blocking layer can be inserted between two adjacent light-emitting layers.

[0216] As the material of the exciton-blocking layer, a known exciton-blocking layer material can be used, for example, 1,3-dicarbazolylbenzene (mCP) or bis(2-methyl-8-hydroxyquinoline)-4-phenylphenol aluminum (III) (BAlq) can be mentioned.

[0217] -Hole transport layer-

[0218] The hole transport layer includes a hole transport material having the function of transporting holes, and the hole transport layer may be provided as a single layer or multiple layers.

[0219] As a hole transport material, it is a material having any of the properties of hole injection or transport and electron barrier, and can be any of organic and inorganic substances. In the hole transport layer, any one can be selected from previously known compounds and used. As the hole transport material, for example, 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, styryl anthracene derivatives, fluorenone derivatives, hydrazone derivatives, distyrene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, especially thiophene oligomers, etc., preferably using porphyrin derivatives, arylamine derivatives and styrylamine derivatives, more preferably using arylamine derivatives.

[0220] -Electron transport layer-

[0221] The electron transport layer includes a material having a function of transporting electrons, and the electron transport layer may be provided as a single layer or multiple layers.

[0222] As an electron transport material (sometimes also serving as a hole blocking material), it is sufficient as long as it has the function of transmitting the electrons injected from the cathode to the light-emitting layer. The electron transport layer can be selected from any of the previously known compounds, for example, polycyclic aromatic derivatives such as naphthalene, anthracene, and phenanthroline, tris(8-hydroxyquinoline)aluminum(III) derivatives, phosphine oxide derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, dioxide thiopyran derivatives, carbodiimide, fluorenyl methane derivatives, anthraquinone dimethane derivatives and anthrone derivatives, bipyridine derivatives, quinoline derivatives, oxadiazole derivatives, benzimidazole derivatives, benzothiazole derivatives, indole and carbazole derivatives, etc., and further, polymer materials that introduce these materials into polymer chains or use these materials as the main chain of polymers can also be used.

[0223] The method for manufacturing an organic electroluminescent element of the present invention comprises: a step of premixing a first main material represented by the general formula (1) and a second main material represented by the general formula (2), and a step of forming a light-emitting layer by vapor deposition of the obtained mixture from an evaporation source. By premixing the two main materials in this way, the performance of the organic EL element can be improved. As a premixing method, it is ideal to use a method that can mix as evenly as possible, and examples include pulverization mixing, heating and melting under reduced pressure or in an inert gas atmosphere such as nitrogen, sublimation, etc., but are not limited to these methods. In addition, the form of the main body and its premixture can be powder, rod-shaped, or granular.

[0224] In order to perform co-evaporation from one evaporation source, the composition obtained by the premixing preferably has a 50% weight reduction temperature difference between the first host material represented by the general formula (1) and the second host material represented by the general formula (2) within 20°C.

[0225] Here, the 50% weight loss temperature refers to the temperature at which the weight is reduced by 50% when the temperature is increased from room temperature to 550°C at a rate of 10°C per minute in a thermogravimetry-differential thermal analysis (TG-DTA) measurement under a nitrogen flow reduced pressure (1 Pa). It is believed that gasification due to evaporation or sublimation is most intense near this temperature.

[0226] When a plurality of entities are used, each entity may be vapor-deposited from a different vapor deposition source, or a plurality of entities may be vapor-deposited simultaneously from a single vapor deposition source by pre-mixing them before vapor deposition to form a premix.

[0227] Regarding the deuterated compound represented by the general formula (1) or the general formula (2), there are known methods for manufacturing using all or part of the deuterated starting materials, and methods for manufacturing by hydrogen / deuterium exchange reactions. All or part of the deuterated raw materials can be purchased from commercial suppliers, or manufactured by known hydrogen / deuterium exchange reactions. As known hydrogen / deuterium exchange reactions, there are methods in which deuterium gas or its equivalent is acted on a non-deuterated body in the presence of a transition metal catalyst, or methods in which a deuterated solvent (deuterated benzene, etc.) is used to treat a non-deuterated body in the presence of an acid catalyst, etc.

[0228] Example

[0229] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples and can be implemented in various forms without departing from the gist of the present invention.

[0230] In addition, Dα in the formula represents that each compound is independently deuterated with hydrogen in part or in whole.

[0231] Synthesis example 1

[0232] [Chemistry 21]

[0233]

[0234] 160 ml of deuterated benzene (C6D6) and 20.0 g of deuterated trifluoromethanesulfonic acid (Trifluoromethanesulfonic acid-d, TfOD) were added to 6.8 g of compound (a), and the mixture was heated and stirred at 50° C. for 4 hours under a nitrogen atmosphere. The reaction solution was added to a deuterated aqueous solution (400 ml) of sodium carbonate (14.8 g) for quenching, and then separated and purified to obtain 6.0 g of compound (a)-D as a deuterated product.

[0235] Synthesis example 2

[0236] [Chemistry 22]

[0237]

[0238] 160 ml of deuterated benzene (C6D6) and 50.0 g of deuterated trifluoromethanesulfonic acid (TfOD) were added to 15.0 g of compound (b), and heated and stirred for 2 hours at room temperature (RT) under a nitrogen atmosphere. The reaction solution was added to a deuterated aqueous solution (800 ml) of sodium carbonate (36.8 g) for quenching, separation, and purification to obtain 14.0 g of compound (b)-D as a deuterated product.

[0239] Synthesis example 3

[0240] [Chemistry 23]

[0241]

[0242] To 5 g of compound (a)-D, 5.6 g of compound (b)-D, 8.6 g of tripotassium phosphate, and 60 ml of 1,3-dimethyl-2-imidazolidinone were added, and the mixture was stirred at 200° C. for 48 hours under a nitrogen atmosphere. After cooling to room temperature, the mixture was purified by silica gel column chromatography and crystallization to obtain 6.6 g (yield 70%) of the intermediate (1-1-D1) as a white solid.

[0243] Under a nitrogen atmosphere, 1.3 g of 60% by weight sodium hydride was added to 30 ml of N, N'-dimethylacetamide to prepare a suspension. 6 g of the intermediate (1-1-D1) dissolved in 170 mL of N, N'-dimethylacetamide was added thereto and stirred for 30 minutes. 5.1 g of compound (c) was added thereto and stirred for 6 hours. The reaction solution was added to a mixed solution of methanol (300 ml) and distilled water (100 ml) while stirring, and the precipitated solid obtained was filtered out. The obtained solid was refined and crystallized by silica gel column chromatography to obtain 6.5 g (yield 66%) of compound 104-2 as a yellow solid.

[0244] For compound 104-2, the deuteration rate was obtained by proton nuclear magnetic resonance spectroscopy. The test sample was prepared by dissolving compound 104-2 (5.0 mg) and dimethyl sulfone (2.0 mg) as an internal standard substance in deuterated tetrahydrofuran (1.0 ml). According to the integrated intensity ratio of the internal standard substance and the compound 104-2 source, the average proton concentration [mol / g] of compound 104-2 contained in the test sample was calculated. In addition, the average proton concentration [mol / g] was also calculated for the non-deuterated body of compound 104-2 (equivalent to comparative example compound C). Next, the ratio of the proton concentration of compound 104-2 to the proton concentration of comparative example compound C was calculated and subtracted from 1 to calculate the average deuteration rate of compound 104-2.

[0245] Synthesis example 4

[0246] [Chemistry 24]

[0247]

[0248] To 6.6 g of compound (1-1) were added 160 ml of deuterated benzene (C6D6) and 10.0 g of deuterated trifluoromethanesulfonic acid (TfOD), and the mixture was heated and stirred at 50° C. for 4 hours under a nitrogen atmosphere. The reaction solution was added to a deuterated aqueous solution (100 ml) of sodium carbonate (8.0 g) and quenched, and separated and purified to obtain 5.4 g of compound (1-1-D2) as a deuterated product.

[0249] Synthesis example 5

[0250] [Chemistry 25]

[0251]

[0252] Under a nitrogen atmosphere, 1.3 g of 60 wt% sodium hydride was added to 30 ml of N, N'-dimethylacetamide to prepare a suspension. 5.0 g of the intermediate (1-1-D2) dissolved in 170 mL of N, N'-dimethylacetamide was added thereto and stirred for 30 minutes. 4.3 g of compound (c) was added thereto and stirred for 6 hours. The reaction solution was added to a mixed solution of methanol (300 ml) and distilled water (100 ml) while stirring, and the precipitated solid obtained was filtered out. The obtained solid was refined and crystallized by silica gel column chromatography to obtain 5.8 g (yield 71%) of compound 104-1 as a yellow solid.

[0253] The same reactions as in Synthesis Examples 1 to 5 were carried out to synthesize deuterated compounds 101-2, 102-2, 101-3, 107-2, 108-1, 108-2, 115-2, 116-2, 117-2, 1451-2, 119-2, 106-2, 106-3, 1642-2, 1642-3, 1665-2, 1665-3, 1639-2, 1673-2, 120-2, 149-2, 172-2, and 1524-2. In addition, the deuteration rates of 101-2, 102-2, 101-3, 104-1, 107-2, 108-1, 108-2, 115-2, 116-2, 117-2, 1451-2, 119-2, 106-2, 106-3, 1642-2, 1642-3, 1665-2, 1665-3, 1639-2, 1673-2, 120-2, 149-2, 172-2, and 1524-2 were calculated in the same manner as 104-2. 1 ,Ar 1 and Ar 2 , and Ar 3 The deuteration rate of the partial structure of the compound 101-2 or the compound 101-3 is calculated in the same manner as described above based on the integrated intensity of the chemical shift derived from the partial structure of the object. In addition, in Table 1 below, the number of hydrogens before deuteration represents the number of all hydrogens contained in each partial structure or the whole of each compound, and the average deuteration rate represents the ratio of their hydrogens being deuterated. In addition, for example, when represented as compound 101-2 or compound 101-3, compounds having the same structure but different deuteration rates are represented.

[0254] [Table 1]

[0255]

[0256] Synthesis Example 7

[0257] According to the following reaction, compound (2) was synthesized.

[0258] [Chemistry 26]

[0259]

[0260] 150 ml of deuterated chloroform (CDCl3) and 30.5 g of iron (III) chloride were added to compound (1) (10.0 g), and the mixture was stirred at room temperature for 12 hours under a nitrogen atmosphere. 300 g of methanol was added to the reaction solution for dilution, followed by separation and purification to obtain 2.9 g of compound (2) as a deuterated product in the form of a white solid.

[0261] Synthesis example 8

[0262] Compound (3) was synthesized by the following reaction. Compound (2) shows an example of a structural formula when the deuteration rate of hydrogen atoms on two carbazole rings is 100%, and the same is true for Compound (3).

[0263] [Chemistry 27]

[0264]

[0265] 1.9 g of bromobenzene-d5, 300 ml of m-xylene, 0.3 g of bis(tri-tert-butylphosphine)palladium, and 7.0 g of potassium carbonate were added to compound (2) (3.5 g), and the mixture was stirred for 5 hours under heating reflux in a nitrogen atmosphere. The reaction solution was cooled, separated, and purified to obtain 2.0 g of compound (3) as a deuterated product in the form of a white solid.

[0266] Synthesis example 9

[0267] Compound 202-2 was synthesized by the following reaction. Compound 202-2 shows an example of a structural formula in which the deuteration rate of hydrogen atoms on two carbazole rings and hydrogen atoms on the biphenyl group on N of biscarbazole is 100%.

[0268] [Chemistry 28]

[0269]

[0270] 2.1 g of deuterated p-bromobiphenyl, 100 ml of m-xylene, 0.2 g of bis(tri-tert-butylphosphine)palladium, and 4.9 g of potassium carbonate were added to compound (3) (3.0 g), and the mixture was stirred for 5 hours under heating and reflux in a nitrogen atmosphere. The reaction solution was cooled, separated, and purified to obtain 1.4 g of compound 202-2 as a deuterated product in the form of a white solid.

[0271] Synthesis example 10

[0272] According to the following reaction, compound 202-1 was synthesized.

[0273] [Chemistry 29]

[0274]

[0275] 160 ml of deuterated benzene (C6D6) and 10.0 g of deuterated trifluoromethanesulfonic acid (TfOD) were added to 8.3 g of comparative compound H, and the mixture was heated and stirred at 50° C. for 6.5 hours under a nitrogen atmosphere. The reaction solution was added to a deuterated aqueous solution (200 ml) of sodium carbonate (7.4 g) for quenching, and then separated and purified to obtain 2.5 g of compound 202-1 as a deuterated product in the form of a white solid.

[0276] Synthesis Example 11

[0277] According to the following reaction, compound (5) was synthesized.

[0278] [Chemistry 30]

[0279]

[0280] 240 ml of deuterated benzene (C6D6) and 18.4 g of deuterated trifluoromethanesulfonic acid (TfOD) were added to 10.0 g of compound (4), and the mixture was heated and stirred at 50°C for 5.0 hours under a nitrogen atmosphere. The reaction solution was added to a deuterated aqueous solution (150 ml) of sodium carbonate (14.3 g) and quenched, and then separated and purified to obtain 8.9 g of compound (5) as a deuterated product.

[0281] Synthesis example 12

[0282] According to the following reaction, compound 202-3 was synthesized.

[0283] [Chemistry 31]

[0284]

[0285] 4.3 g of p-bromobiphenyl, 100 ml of m-xylene, 0.4 g of bis(tri-tert-butylphosphine)palladium, and 5.0 g of potassium carbonate were added to compound (5) (5.0 g), and the mixture was stirred for 5 hours under heating and reflux in a nitrogen atmosphere. The reaction solution was cooled, separated, and purified to obtain 2.7 g of compound 202-3 as a deuterated product in the form of a white solid.

[0286] Synthesis example 13

[0287] Compound 205-1, Compound 205-2, and Compound 208-2 were synthesized as deuterated products by the same reaction as in Synthesis Examples 7 to 10. In addition, the following biscarbazole skeletons and their substituents R were calculated in the same manner as in 104-2. 2 , and Ar 5 with Ar 6 The deuteration rate of the partial structure and the overall deuteration rate.

[0288] [Table 2]

[0289]

[0290] The compounds used in Examples and Comparative Examples are shown below.

[0291] [Chemistry 32]

[0292]

[0293] [Chemistry 33]

[0294]

[0295] Example 1

[0296] On a glass substrate formed with an anode containing ITO with a film thickness of 110nm, various thin films were stacked at a vacuum degree of 4.0×10-5Pa using a vacuum evaporation method. First, HAT-CN was formed to a thickness of 25nm on ITO as a hole injection layer, and then Spiro (spiro)-TPD was formed to a thickness of 30nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10nm as an electron blocking layer. Next, compound 108-1 as the first main body, compound 202-1 as the second main body, and Ir(ppy)3 as a light-emitting dopant were co-evaporated from different evaporation sources to form a light-emitting layer with a thickness of 40nm. At this time, co-evaporation was performed under evaporation conditions in which the concentration of Ir(ppy)3 was 10wt% and the weight ratio of the first main body to the second main body was 30:70. Next, ET-1 was formed to a thickness of 20nm as an electron transport layer. Furthermore, LiF was formed to a thickness of 1 nm on the electron transport layer as an electron injection layer, and finally Al was formed to a thickness of 70 nm on the electron injection layer as a cathode, thereby manufacturing an organic EL device.

[0297] Example 2 to Example 25, Example 31 to Example 47

[0298] An organic EL device was produced in the same manner as in Example 1 except that the compounds shown in Table 3 were used as the first host and the second host and the weight ratios shown in Table 3 were used.

[0299] Example 26 to Example 30, Example 48 to Example 59

[0300] The first main body and the second main body shown in Table 3 were weighed in a weight ratio shown in Table 3 and ground and mixed in a mortar to obtain a premix, and the premix was vapor-deposited from a vapor deposition source. An organic EL element was prepared in the same manner as in Example 1, except that the premix was vapor-deposited from a vapor deposition source.

[0301] Comparative Examples 1 to 9

[0302] An organic EL device was produced in the same manner as in Example 1 except that the compounds shown in Table 3 were used as the first host and the second host and the weight ratios shown in Table 3 were used.

[0303] Comparative Examples 10 to 13

[0304] The first main body and the second main body shown in Table 3 were weighed in a weight ratio shown in Table 3 and ground and mixed in a mortar to obtain a premix, and the premix was vapor-deposited from a vapor deposition source. An organic EL element was prepared in the same manner as in Example 1, except that the premix was vapor-deposited from a vapor deposition source.

[0305] The evaluation results of the produced organic EL elements are shown in Table 3. In the table, the brightness, voltage, and power efficiency are the values ​​at a driving current of 10 mA / cm2 and are initial characteristics. LT97 is the time it takes for the brightness to decay to 97% when the initial brightness at a driving current of 20 mA / cm2 is set to 100%, and represents the life characteristics. The weight ratio is the first main body: the second main body.

[0306] [Table 3-1]

[0307]

[0308] [Table 3-2]

[0309]

[0310] From the results of Table 3-1 and Table 3-2, it can be seen that Examples 1 to 59 show a long life characteristic compared to the comparative examples.

[0311] Table 4 shows the 50% weight loss temperature (T50) of the compounds used in Examples and Comparative Examples.

[0312] [Table 4]

[0313] Compound T50[℃] 101-2 279 101-3 281 104-2 280 102-2 288 106-2 290 106-3 290 1642-2 274 1642-3 276 1665-2 277 1665-3 277 1639-2 315 1673-2 279 120-2 274 149-2 293 172-2 279 1524-2 278 202-2 283 208-2 292 205-2 317 H 283 I 292

[0314] Industrial Applicability

[0315] According to the present invention, by mixing a first host having a nitrogen-containing six-membered ring and a phenyl or biphenyl group in an indole carbazole and further substituted with deuterium, and a deuterium-substituted biscarbazole compound as a second host, an organic EL element having low voltage, high efficiency and long life can be obtained. In addition, by mixing the first host with the previous second host to prepare a premix, and then using the host material containing the premix, an organic EL element with high brightness, high efficiency and long life can be obtained.

[0316] Description of Figure Numbers

[0317] 1: Substrate

[0318] 2: Anode

[0319] 3: Hole injection layer

[0320] 4: Hole transport layer

[0321] 5: Luminous layer

[0322] 6: Electron transport layer

[0323] 7: Cathode

Claims

1. An organic electroluminescent element comprising one or more luminescent layers between an anode and a cathode facing each other, wherein at least one luminescent layer comprises: a first host selected from a compound represented by the following general formula (1); a second host selected from a compound represented by the following general formula (2); and a luminescent dopant material, [Chemistry 1] (In the general formula (1), ring F is a heterocyclic ring represented by the formula (1f) which is condensed with two adjacent benzene rings at any positions; Ar 1 and Ar 2 are independently a substituted or unsubstituted phenyl group containing deuterium, or a substituted or unsubstituted biphenyl group containing deuterium; Ar 3 is a deuterated substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a deuterated substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a deuterated substituted or unsubstituted linked aromatic group in which two to five of these aromatic groups are linked, and the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different; R 1 Each of the following is independently deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms and containing deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms and containing deuterium, or a substituted or unsubstituted linked aromatic group containing deuterium formed by linking 2 to 5 of these aromatic groups, wherein the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different; a to c are the number of substitutions, a and c are integers of 0 to 4, and b is an integer of 0 to 2; wherein, R 1 At least one of the following is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group which is partially or entirely substituted with deuterium in which two to five of these aromatic groups are linked, and the indolecarbazole skeleton and R as a substituent thereof are 1 The average deuteration rate of all hydrogen contained in the Ar 3 Some or all of the hydrogen contained in Ar is replaced by deuterium. 3 The average deuteration rate of all hydrogen contained in the [Chemistry 2] (Here, Ar 5 and Ar 6 Each independently represents a deuterium-containing substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a deuterium-containing substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic groups, and the linked aromatic hydrocarbon groups may be the same or different; R 2 are independently deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms and containing deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms and containing deuterium, or a substituted or unsubstituted linked aromatic group containing deuterium formed by linking 2 to 5 of these aromatic groups, wherein the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different; d to g are the number of substitutions, d and g are integers of 0 to 4, and e and f are integers of 0 to 3; wherein R 2 At least one of the following is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group which is partially or entirely substituted with deuterium in which two to five of these aromatic groups are linked, and the bicarbazole skeleton and R as the substituent are 2 The average deuteration rate of all hydrogen contained in the Ar 5 and Ar 6 Some or all of the hydrogen contained in Ar is replaced by deuterium. 5 and Ar 6 The average deuteration rate of all hydrogen contained in the mixture is more than 30%).

2. The organic electroluminescent element according to claim 1, characterized in that: In the general formula (1), Ar 3 is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, a substituted or unsubstituted quaterphenyl group containing deuterium, a substituted or unsubstituted dibenzofuranyl group containing deuterium, or a substituted or unsubstituted dibenzothienyl group containing deuterium.

3. The organic electroluminescent element according to claim 1, characterized in that: In the general formula (1), Ar 3 is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, or a substituted or unsubstituted quaterphenyl group containing deuterium.

4. The organic electroluminescent element according to claim 1, characterized in that: In the general formula (1), Ar 3 The average deuteration rate of all hydrogen contained in the gas is more than 70%.

5. The organic electroluminescent element according to claim 1, characterized in that: In the general formula (1), R 1 For deuterium.

6. The organic electroluminescent element according to claim 1, characterized in that: In the general formula (2), Ar 5 and Ar 6 is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, a substituted or unsubstituted dibenzofuranyl group containing deuterium, or a substituted or unsubstituted dibenzothienyl group containing deuterium.

7. The organic electroluminescent element according to claim 1, characterized in that: In the general formula (2), Ar 5 and Ar 6 is a substituted or unsubstituted phenyl group containing deuterium, or a substituted or unsubstituted biphenyl group containing deuterium.

8. The organic electroluminescent element according to claim 1, characterized in that: In the general formula (2), Ar 5 and Ar 6 The average deuteration rate of all hydrogen in the reactor is above 50%.

9. The organic electroluminescent element according to claim 1, wherein: In the general formula (2), R 2 For deuterium.

10. The organic electroluminescent element according to claim 1, characterized in that: The ratio of the first body to the total of the first body and the second body is 10 wt % or more and less than 80 wt %.

11. The organic electroluminescent element according to claim 1, characterized in that: The light-emitting dopant material is an organic metal complex containing at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold.

12. The organic electroluminescent element according to claim 1, characterized in that: The luminescent dopant material is a thermally activated delayed fluorescence luminescent dopant material.

13. A premixture comprising a first host and a second host, for forming a light-emitting layer in an organic electric field light-emitting element, wherein the organic electric field light-emitting element comprises the light-emitting layer containing the host and a light-emitting dopant material between an anode and a cathode facing each other, wherein the first host is selected from a compound represented by the following general formula (1), and the second host is selected from a compound represented by the following general formula (2), [Chemistry 3] (In the general formula (1), ring F is a heterocyclic ring represented by the formula (1f) which is condensed with two adjacent benzene rings at any positions; Ar 1 and Ar 2 are independently a substituted or unsubstituted phenyl group containing deuterium, or a substituted or unsubstituted biphenyl group containing deuterium; Ar 3 is a deuterated substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a deuterated substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a deuterated substituted or unsubstituted linked aromatic group in which two to five of these aromatic groups are linked, and the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different; R 1 Each of the following is independently deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms and containing deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms and containing deuterium, or a substituted or unsubstituted linked aromatic group containing deuterium formed by linking 2 to 5 of these aromatic groups, wherein the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different; a to c are the number of substitutions, a and c are integers of 0 to 4, and b is an integer of 0 to 2; wherein, R 1 At least one of the following is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group which is partially or entirely substituted with deuterium in which two to five of these aromatic groups are linked, and the indolecarbazole skeleton and R as a substituent thereof are 1 The average deuteration rate of all hydrogen contained in is 50% or more; in addition, Ar 3 Some or all of the hydrogen contained in Ar is replaced by deuterium. 3 The average deuteration rate of all hydrogen contained in the [Chemistry 4] (Here, Ar 5 and Ar 6 Each independently represents a deuterium-containing substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a deuterium-containing substituted or unsubstituted linked aromatic group formed by linking 2 to 5 of these aromatic groups, and the linked aromatic hydrocarbon groups may be the same or different; R 2 Each of them is independently deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms and containing deuterium, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms and containing deuterium, or a substituted or unsubstituted linked aromatic group containing deuterium formed by linking 2 to 5 of these aromatic groups, and the linked aromatic hydrocarbon groups or aromatic heterocyclic groups may be the same or different; d to g are the number of substitutions, d and g are integers of 0 to 4, and e and f are integers of 0 to 3; wherein R 2 At least one of the following is deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms which is partially or entirely substituted with deuterium, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms which is partially or entirely substituted with deuterium, or a substituted or unsubstituted linked aromatic group which is partially or entirely substituted with deuterium in which two to five of these aromatic groups are linked, and the bicarbazole skeleton and R as the substituent are 2 The average deuteration rate of all hydrogen contained in is 50% or more; in addition, Ar 5 and Ar 6 A portion of the hydrogen contained in Ar is replaced by deuterium. 5 and Ar 6 The average deuteration rate of all hydrogen contained in the mixture is more than 30%).

14. The premix according to claim 13, wherein In the general formula (1), Ar 3 is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, a substituted or unsubstituted quaterphenyl group containing deuterium, a substituted or unsubstituted dibenzofuranyl group containing deuterium, or a substituted or unsubstituted dibenzothienyl group containing deuterium.

15. The premix according to claim 13, characterized in that In the general formula (1), Ar 3 is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, or a substituted or unsubstituted quaterphenyl group containing deuterium.

16. The premix according to claim 13, characterized in that In the general formula (1), Ar 3 The average deuteration rate of all hydrogen contained in the gas is more than 70%.

17. The premix according to claim 13, characterized in that In the general formula (1), R 1 For deuterium.

18. The premix according to claim 13, characterized in that In the general formula (2), Ar 5 and Ar 6 is a substituted or unsubstituted phenyl group containing deuterium, a substituted or unsubstituted biphenyl group containing deuterium, a substituted or unsubstituted terphenyl group containing deuterium, a substituted or unsubstituted dibenzofuranyl group containing deuterium, or a substituted or unsubstituted dibenzothienyl group containing deuterium.

19. The premix according to claim 13, characterized in that In the general formula (2), Ar 5 and Ar 6 is a substituted or unsubstituted phenyl group containing deuterium, or a substituted or unsubstituted biphenyl group containing deuterium.

20. The premix according to claim 13, characterized in that In the general formula (2), Ar 5 and Ar 6 The average deuteration rate of all hydrogen in the reactor is above 50%.

21. The premix according to claim 13, wherein In the general formula (2), R 2 For deuterium.

22. The premix according to claim 13, characterized in that The ratio of the compound represented by the general formula (1) to the total of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 10 wt % or more and less than 80 wt %.

23. The premix according to claim 13, characterized in that The difference in 50% weight loss temperature between the compound represented by the general formula (1) and the compound represented by the general formula (2) is within 20°C.

24. A method for manufacturing an organic electroluminescent element, characterized in that: When manufacturing the organic electric field light-emitting element according to claim 1, the following steps are included: after mixing the first host represented by the general formula (1) and the second host represented by the general formula (2) to prepare a premix, the host material containing the premix is ​​evaporated to form a light-emitting layer.

Images