Charge transport composition

Abstract

The present invention provides a charge transport composition, which comprises: a charge transport material containing a polythiophene derivative represented by formula (1) or an amine adduct thereof, an organosilane compound selected from silanes containing a fluoroalkyl group, etc., metal oxide nanoparticles, and an organic solvent. (R 1 and R 2 are each independently a hydrogen atom, an alkoxy group having 1 to 40 carbon atoms, -O-[Z-O] p -R e , or a sulfonic acid group, etc., or is -O-Y-O- formed by the combination of R 1 and R 2 , Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted with a sulfonic acid group, Z is an alkylene group having 1 to 40 carbon atoms which may be substituted with a halogen atom, p is an integer of 1 or more, and R e is a hydrogen atom, or an alkyl group having 1 to 40 carbon atoms, etc.).

Description

Technical Field

[0001] The present invention relates to a charge transporting composition. Background Art

[0002] Regarding organic electroluminescence (EL) elements, practical applications in fields such as displays and lighting are expected. Therefore, in recent years, various developments related to materials and element structures have been carried out for the purpose of low-voltage driving, high brightness, long life, etc.

[0003] In this organic EL element, from the viewpoint of improving its performance, multiple functional thin films are used. Among them, the hole injection layer and the hole transport layer are responsible for the transfer of charges between the anode and the light-emitting layer, and play an important role in reducing the voltage driving of the organic EL element and increasing the brightness.

[0004] The formation methods of the hole injection layer and the hole transport layer are roughly divided into dry methods represented by evaporation methods and wet methods represented by spin coating methods. If these methods are compared, the wet method can manufacture a thin film with high flatness with high efficiency over a large area. Therefore, the wet method is often used especially in the field of displays.

[0005] At present, when seeking to improve the performance of organic EL elements, the wet materials for the hole injection layer and the hole transport layer often need to be improved. In particular, since they can contribute to the improvement of the brightness characteristics and the life characteristics of organic EL elements, the urgent expectation for materials that can provide a charge transporting thin film with excellent flatness is increasing day by day.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-045667

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2007-169593

[0010] Patent Document 3: International Publication No. 2017 / 014946

[0011] Patent Document 4: International Publication No. 2008 / 129947

[0012] Patent Document 5: International Publication No. 2017 / 041701 Summary of the Invention

[0013] Problems to be Solved by the Invention

[0014] The present invention has been completed in view of the above actual situation, and an object thereof is to provide a charge transport composition capable of giving a film having high flatness and high charge transportability and achieving excellent brightness characteristics when applied to an organic EL element.

[0015] Means for Solving the Problems

[0016] The inventors of the present invention conducted intensive studies repeatedly in order to achieve the above object, and as a result, found that a charge transport composition containing a specified charge transport substance containing a polythiophene derivative or an amine adduct thereof, a specified organosilane compound having a fluorine atom, metal oxide nanoparticles, and a solvent can give a film having high flatness and high charge transportability, and also found that when this film is applied to an organic EL element, excellent brightness characteristics can be achieved, thereby completing the present invention.

[0017] Furthermore, it has been reported that by containing glycidoxypropyltrimethoxysilane and a specified siloxane-based substance in a composition containing a conductive polymer such as polystyrene sulfonic acid and polyaniline, the brightness characteristics and lifetime of an organic EL element including a film obtained from this composition can be improved (see Patent Documents 1 and 2), but there is no report on a charge transport composition containing the organosilane compound used in the present invention.

[0018] That is, the present invention provides:

[0019] 1. A charge transport composition, characterized by containing: a charge transport substance having a polythiophene derivative or an amine adduct thereof containing a repeating unit represented by formula (1), at least one organosilane compound selected from a silane containing a fluoroalkyl group and a silane containing a fluoroaryl group, metal oxide nanoparticles, and a solvent,

[0020] [Chemical Formula 1]

[0021]

[0022] (In the formula, R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, -O-[Z-O] p -R e , or a sulfonic acid group, or is -O-Y-O- formed by the combination of R 1 and R 2 , Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted with a sulfonic acid group, Z is an alkylene group having 1 to 40 carbon atoms which may be substituted with a halogen atom, p is an integer of 1 or more, R eis a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms.)

[0023] 2. The charge transporting composition according to 1, wherein the silane containing a fluoroalkyl group and the silane containing a fluoroaryl group each have a fluoroalkyl group and a fluoroaryl group at at least one molecular terminal,

[0024] 3. The charge transporting composition according to 1 or 2, wherein the fluoroalkyl group and the fluoroaryl group are a perfluoroalkyl group and a perfluoroaryl group, respectively,

[0025] 4. The charge transporting composition according to 3, wherein the organosilane compound is at least one selected from the following formulas (A1) and (B1),

[0026] [Chemical formula 2]

[0027]

[0028] (In the formula, R 3 is a single bond, an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, an ester bond, an ether bond or a carbonyl bond, R 4 and R 5 are independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a trialkylsilyl group having 1 to 10 carbon atoms, X is a perfluoroalkyl group having 1 to 20 carbon atoms or a perfluoroaryl group having 6 to 20 carbon atoms, L is O, S or N, m is 1 or 2, and n is 2 or 3.)

[0029] 5. The charge transporting composition according to any one of 1 to 4, wherein the metal oxide nanoparticles are SiO 2 ,

[0030] 6. The charge transporting composition according to any one of 1 to 5, wherein the R 1 is a sulfonic acid group, the R 2 is an alkoxy group having 1 to 40 carbon atoms or -O-[Z-O] p -R e , or the R 1 and R 2 are -O-Y-O- formed by the combination of R 1 and R 2 ,

[0031] 7. The charge transporting composition according to any one of 1 to 6, which further comprises an electron-accepting dopant substance,

[0032] 8. The charge transporting composition according to 7, wherein the electron-accepting dopant substance is an arylsulfonic acid compound,

[0033] 9. A charge transporting film obtained from the charge transporting composition according to any one of 1 to 8,

[0034] 10. An organic electroluminescent element having the charge-transporting thin film of 9.

[0035] 11. The organic electroluminescent element of 10, wherein the charge-transporting thin film is a hole injection layer or a hole transport layer.

[0036] 12. A method for manufacturing a charge-transporting thin film, characterized in that the charge-transporting composition according to any one of 1 to 8 is coated on a substrate and the solvent is evaporated.

[0037] 13. A method for manufacturing an organic electroluminescent element, characterized in that the charge-transporting thin film of 9 is used.

[0038] Effects of the Invention

[0039] By using the charge-transporting composition of the present invention, a charge-transporting thin film with good flatness can be obtained with good reproducibility by various wet processes.

[0040] By applying the charge-transporting thin film of the present invention with good flatness to the hole injection layer, hole transport layer, preferably the hole injection layer of an organic EL element, reduction of the driving voltage of the element, improvement of the quantum efficiency, and extension of the lifetime can be achieved.

[0041] In addition, the charge-transporting composition of the present invention can also manufacture a thin film with excellent charge transportability with good reproducibility even in the case of various wet processes such as spin coating method and inkjet method that can form a film over a large area, and thus can also sufficiently meet the development in the field of organic EL elements in recent years. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Emission images of the organic EL elements fabricated in Examples 3-1 to 3-3 and Comparative Examples 3-1 to 3-3. DETAILED DESCRIPTION

[0043] The present invention will be described in more detail below. It should be noted that in the present invention, the "solid content" related to the charge-transporting composition of the present invention means the components other than the solvent contained in the composition. In addition, the charge transportability is synonymous with conductivity and synonymous with hole transportability.

[0044] The charge-transporting composition of the present invention contains: a charge-transporting substance having a polythiophene derivative or its amine adduct containing a repeating unit represented by the formula (1), at least one organosilane compound selected from a silane containing a fluoroalkyl group and a silane containing a fluoroaryl group, metal oxide nanoparticles, and an organic solvent.

[0045] [Chemical Formula 3]

[0046]

[0047] In the formula, R 1 and R 2 are independently a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, -O-[Z-O] p -R e or a sulfonic acid group, or is -O-Y-O- formed by the combination of R 1 and R 2 ; Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted with a sulfonic acid group; Z is an alkylene group having 1 to 40 carbon atoms which may be substituted with a halogen atom; p is an integer of 1 or more; R e is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0048] As the alkyl group having 1 to 40 carbon atoms, a linear, branched or cyclic one is acceptable. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, docosyl, triacontyl, and tetracosyl, etc. An alkyl group having 1 to 18 carbon atoms is preferred, and an alkyl group having 1 to 8 carbon atoms is more preferred.

[0049] Examples of the fluoroalkyl group having 1 to 40 carbon atoms include groups in which at least one hydrogen atom of the above alkyl group having 1 to 40 carbon atoms is replaced by a fluorine atom, and there is no particular limitation. For example, fluoromethyl, difluoromethyl, perfluoromethyl, 1-fluoroethyl, 2-fluoroethyl, 1,2-difluoroethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, 1,1,2-trifluoroethyl, 1,2,2-trifluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, 1,2,2,2-tetrafluoroethyl, perfluoroethyl, 1-fluoropropyl, 2-fluoropropyl, 3-fluoropropyl, 1,1-difluoropropyl, 1,2-difluoropropyl, 1,3-difluoropropyl, 2,2-difluoropropyl, 2,3-difluoropropyl, 3,3-difluoropropyl, 1,1,2-trifluoropropyl, 1,1,3-trifluoropropyl, 1,2,3-trifluoropropyl, 1,3,3-trifluoropropyl, 2,2,3-trifluoropropyl, 2,3,3-trifluoropropyl, 3,3,3-trifluoropropyl, 1,1,2,2-tetrafluoropropyl, 1,1,2,3-tetrafluoropropyl, 1,2,2,3-tetrafluoropropyl, 1,3,3,3-tetrafluoropropyl, 2,2,3,3-tetrafluoropropyl, 2,3,3,3-tetrafluoropropyl, 1,1,2,2,3-pentafluoropropyl, 1,2,2,3,3-pentafluoropropyl, 1,1,3,3,3-pentafluoropropyl, 1,2,3,3,3-pentafluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl, and perfluorooctyl can be mentioned.

[0050] Examples of the alkoxy group having 1 to 40 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, c-propoxy group, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, n-nonadecyloxy, and n-icosyloxy, but are not limited thereto. Herein, the alkyl group may be linear, branched, or cyclic.

[0051] As the fluoroalkoxy group having 1 to 40 carbon atoms, there is no particular limitation as long as at least one hydrogen atom on the carbon atom is substituted with a fluorine atom. For example, fluoro-methoxy, difluoro-methoxy, perfluoro-methoxy, 1-fluoro-ethoxy, 2-fluoro-ethoxy, 1,2-difluoro-ethoxy, 1,1-difluoro-ethoxy, 2,2-difluoro-ethoxy, 1,1,2-trifluoro-ethoxy, 1,2,2-trifluoro-ethoxy, 2,2,2-trifluoro-ethoxy, 1,1,2,2-tetrafluoro-ethoxy, 1,2,2,2-tetrafluoro-ethoxy, perfluoro-ethoxy, 1-fluoro-propoxy, 2-fluoro-propoxy, 3-fluoro-propoxy, 1,1-difluoro-propoxy, 1,2-difluoro-propoxy, 1,3-difluoro-propoxy, 2,2-difluoro-propoxy, 2,3-difluoro-propoxy, 3,3-difluoro-propoxy, 1,1,2-trifluoro-propoxy, 1,1,3-trifluoro-propoxy, 1,2,3-trifluoro-propoxy, 1,3,3-trifluoro-propoxy, 2,2,3-trifluoro-propoxy, 2,3,3-trifluoro-propoxy, 3,3,3-trifluoro-propoxy, 1,1,2,2-tetrafluoro-propoxy, 1,1,2,3-tetrafluoro-propoxy, 1,2,2,3-tetrafluoro-propoxy, 1,3,3,3-tetrafluoro-propoxy, 2,2,3,3-tetrafluoro-propoxy, 2,3,3,3-tetrafluoro-propoxy, 1,1,2,2,3-pentafluoro-propoxy, 1,2,2,3,3-pentafluoro-propoxy, 1,1,3,3,3-pentafluoro-propoxy, 1,2,3,3,3-pentafluoro-propoxy, 2,2,3,3,3-pentafluoro-propoxy, and perfluoro-propoxy can be mentioned.

[0052] As the alkylene group having 1 to 40 carbon atoms, it may be linear, branched or cyclic. For example, methylene, ethylene, propylene, trimethylene, tetramethylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene, octadecylene, nonadecylene, icosylene, etc. can be mentioned, but it is not limited to these.

[0053] As the aryl group having 6 to 20 carbon atoms, for example, phenyl, tolyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, etc. can be mentioned, and phenyl, tolyl and naphthyl are preferred.

[0054] As the aryloxy group having 6 to 20 carbon atoms, for example, phenoxy, anthryloxy, naphthyloxy, phenanthryloxy, fluorenyloxy, etc. can be mentioned, but it is not limited to these.

[0055] As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom can be mentioned.

[0056] In the polythiophene derivative containing the repeating unit represented by the above formula (1), preferably R1 and R 2 are each independently a hydrogen atom, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, -O[C(R a R b )-C(R c R d )-O] p -R e , -OR f , or a sulfonic acid group, or is -O-Y-O- formed by the combination of R 1 and R 2 .

[0057] R a to R d each independently represent a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Specific examples of these groups are the same as those listed above.

[0058] Among them, R a to R d are each independently preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group.

[0059] R e is preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group, more preferably a hydrogen atom, a methyl group, a propyl group, or a butyl group.

[0060] In addition, p is preferably 1, 2, or 3.

[0061] In addition, R f is preferably a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms, more preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group, and further preferably -CH 2 CF 3 .

[0062] In the present invention, R 1 is preferably a hydrogen atom or a sulfonic acid group, more preferably a sulfonic acid group, and R 2 is preferably an alkoxy group having 1 to 40 carbon atoms or -O-[Z-O] p -R e , more preferably -O[C(R a R b )-C(R c R d )-O] p -R e or -OR f , and further preferably -O[C(R a R b)-C(R c R d )-O] p -R e 、-O-CH 2 CH 2 -O-CH 2 CH 2 -O-CH 3 、-O-CH 2 CH 2 -O-CH 2 CH 2 -OH or -O-CH 2 CH 2 -OH, or preferably R 1 and R 2 form -O-Y-O- by combining with each other.

[0063] For example, the above-mentioned polythiophene derivative involved in the preferred embodiment of the present invention includes R 1 being a sulfonic acid group, R 2 being a repeating unit other than a sulfonic acid group, or including R 1 and R 2 forming a repeating unit of -O-Y-O- by combination.

[0064] That is, preferably, the above-mentioned polythiophene derivative includes R 1 being a sulfonic acid group, R 2 being an alkoxy group having 1 to 40 carbon atoms or -O-[Z-O] p -R e repeating units, or including R 1 and R 2 forming a repeating unit of -O-Y-O- by combination.

[0065] More preferably, the above-mentioned polythiophene derivative includes R 1 being a sulfonic acid group, R 2 being -O[C(R a R b )-C(R c R d )-O] p -R e or -OR f repeating units.

[0066] Still more preferably, the above-mentioned polythiophene derivative includes R 1 being a sulfonic acid group, R 2 being -O[C(R a R b )-C(R c R d )-O] p -Re repeating unit, or containing R 1 and R 2 is a repeating unit of -O-Y-O- formed by combination.

[0067] More preferably, the above poly(thiophene) derivative contains R 1 is a sulfonic acid group, R 2 is -O-CH 2 CH 2 -O-CH 2 CH 2 -O-CH 3 -O-CH 2 CH 2 -O-CH 2 CH 2 -OH, or -O-CH 2 CH 2 -OH repeating unit, or containing R 1 and R 2 is a repeating unit of a group represented by the following formulas (Y1) and (Y2) formed by combination.

[0068] [Chemical formula 4]

[0069]

[0070] As a preferred specific example of the above poly(thiophene) derivative, for example, poly(thiophene) containing any one of the repeating units represented by the following formulas (1-1) to (1-5) can be cited.

[0071] [Chemical formula 5]

[0072]

[0073] In addition, the above poly(thiophene) derivative does not necessarily have a sulfonic acid group in all repeating units. Therefore, not all repeating units necessarily have the same structure, and repeating units with different structures may also be included. As a preferred structure, for example, a poly(thiophene) derivative having a structure represented by the following formula (1a) can be cited, but it is not limited thereto. Further, in the following formula, each unit may be combined randomly or as a block polymer.

[0074] [Chemical formula 6]

[0075]

[0076] In the formula, a to d represent the molar ratios of each unit, satisfying 0 ≤ a ≤ 1, 0 ≤ b ≤ 1, 0 < a + b ≤ 1, 0 ≤ c < 1, 0 ≤ d < 1, and a + b + c + d = 1.

[0077] Furthermore, the above-mentioned polythiophene derivatives can be homopolymers or copolymers (statistically, including random, gradient, and block copolymers). As a polymer containing monomer A and monomer B, block copolymers include, for example, A-B diblock copolymers, A-B-A triblock copolymers, and (AB) m - multi-block copolymers. The polythiophene may contain repeating units derived from other types of monomers (such as thienothiophene, selenophene, pyrrole, furan, tellurophene, aniline, arylamine, and arylene (such as phenylene, phenylenevinylene, and fluorene, etc.)).

[0078] In the present invention, regarding the content of the repeating unit represented by formula (1) in the polythiophene derivative, among the repeating units contained in the polythiophene derivative, it is preferably more than 50 mol%, more preferably more than 80 mol%, further preferably more than 90 mol%, still further preferably more than 95 mol%, and most preferably 100 mol%.

[0079] In the present invention, depending on the purity of the initial monomer compound used in the polymerization, the formed polymer may contain repeating units derived from impurities. In the present invention, the term "homopolymer" as described above means a polymer containing repeating units derived from one type of monomer, and may contain repeating units derived from impurities. In the present invention, the above-mentioned polythiophene derivative is preferably a homopolymer in which substantially all repeating units are the repeating units represented by the above formula (1), and more preferably a homopolymer containing at least one of the repeating units represented by the above formulas (1-1) to (1-5).

[0080] In the present invention, when the above-mentioned polythiophene derivative contains a repeating unit having a sulfonic acid group, from the viewpoint of further improving the solubility and dispersibility in an organic solvent, an amine compound can be further used to form an amine adduct in which the amine compound is added to at least a part of the sulfonic acid group contained in the polythiophene derivative.

[0081] Examples of amine compounds that can be used in the formation of amine adducts include monoalkylamine compounds such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-ethylhexylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-nonadecylamine, n-eicosylamine; primary amine compounds such as monoarylamine compounds like aniline, methylaniline, 1-naphthylamine, 2-naphthylamine, 1-anthrylamine, 2-anthrylamine, 9-anthrylamine, 1-phenanthrylamine, 2-phenanthrylamine, 3-phenanthrylamine, 4-phenanthrylamine, 9-phenanthrylamine; secondary amine compounds such as dialkylamine compounds like N-ethylmethylamine, N-methyl-n-propylamine, N-methylisopropylamine, N-methyl-n-butylamine, N-methylsec-butylamine, N-methyltert-butylamine, N-methylisobutylamine, diethylamine, N-ethyl-n-propylamine, N-ethylisopropylamine, N-ethyl-n-butylamine, N-ethylsec-butylamine, N-ethyltert-butylamine, dipropylamine, N-n-propylisopropylamine, N-n-propyl-n-butylamine, N-n-propylsec-butylamine, diisopropylamine, N-n-butylisopropylamine, N-tert-butylisopropylamine, di(n-butyl)amine, di(sec-butyl)amine, diisobutylamine, aziridine, 2-methylaziridine, 2,2-dimethylaziridine, azetidine, 2-methylazetidine, pyrrolidine, 2-methylpyrrolidine, 3-methylpyrrolidine, 2,5-dimethylpyrrolidine, piperidine, 2,6-dimethylpiperidine, 3,5-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, hexamethyleneimine, heptamethyleneimine, octamethyleneimine; diarylamine compounds such as diphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, 1,1'-dinaphthylamine, 2,2'-dinaphthylamine, 1,2'-dinaphthylamine, carbazole, 7H-benzo[c]carbazole, 11H-benzo[a]carbazole, 7H-dibenzo[c,g]carbazole, 13H-dibenzo[a,i]carbazole; and alkylarylamine compounds such as N-methylaniline, N-ethylaniline, N-n-propylaniline, N-isopropylaniline, N-n-butylaniline, N-sec-butylaniline, N-isobutylaniline, N-methyl-1-naphthylamine, N-ethyl-1-naphthylamine, N-n-propyl-1-naphthylamine, indoline, isoindoline, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroisoquinoline.Tertiary amine compounds such as N,N-dimethylethylamine, N,N-dimethyl-n-propylamine, N,N-dimethylisopropylamine, N,N-dimethyl-n-butylamine, N,N-dimethylsec-butylamine, N,N-dimethyltert-butylamine, N,N-dimethylisobutylamine, N,N-diethylmethylamine, N-methylbis(n-propyl)amine, N-methyldiisopropylamine, N-methylbis(n-butyl)amine, N-methyldiisobutylamine, triethylamine, N,N-diethyl-n-butylamine, N,N-diisopropylethylamine, N,N-di(n-butyl)ethylamine, tris(n-propyl)amine, tris(isopropyl)amine, tris(n-butyl)amine, tris(isobutyl)amine, 1-methylazetidine, 1-methylpyrrolidine, 1-methylpiperidine; triarylamine compounds such as triphenylamine; alkyl diarylamine compounds such as N-methyldiphenylamine, N-ethyldiphenylamine, 9-methylcarbazole, 9-ethylcarbazole; and dialkylarylamine compounds such as N,N-diethylaniline, N,N-di(n-propyl)aniline, N,N-di(isopropyl)aniline, N,N-di(n-butyl)aniline. Considering the balance of the solubility of the amine adduct and the charge transport properties of the resulting charge transport film, tertiary amine compounds are preferred, trialkylamine compounds are more preferred, and triethylamine is further preferred.

[0082] The amine adduct can be obtained by adding a polythiophene derivative to the amine itself or its solution and stirring well.

[0083] In the present invention, the above-mentioned polythiophene derivative or its amine adduct can be a product treated with a reducing agent.

[0084] In the case of the polythiophene derivative or its amine adduct, in some of the repeating units constituting them, the chemical structure sometimes becomes an oxidized structure called a "quinone-type structure". The term "quinone-type structure" is used relative to the term "benzene-type structure". Relative to the latter, which is a structure containing an aromatic ring, the former means that the double bond within the aromatic ring moves outside the ring (as a result, the aromatic ring disappears), forming two exocyclic double bonds conjugated with the other double bonds remaining within the ring. For those skilled in the art, the relationship between these two structures can be easily understood from the relationship between the structures of benzoquinone and hydroquinone. The quinone-type structure of the repeating units of various conjugated polymers is well known to those skilled in the art. As an example, the quinone-type structure corresponding to the repeating unit of the polythiophene derivative represented by the above formula (1) is shown in the following formula (1').

[0085] [Chemical formula 7]

[0086]

[0087] In formula (1'), R 1 and R 2 are as defined in the above formula (1).

[0088] The quinoid structure is formed by a doping reaction, which is a process in which a polythiophene derivative containing a repeating unit represented by the above formula (1) undergoes an oxidation reaction using a dopant. It forms a part of the structures called "polaron structure" and "bipolaron structure" that impart charge transport properties to the polythiophene derivative. These structures are well-known. In the fabrication of an organic EL device, the introduction of the "polaron structure" and / or "bipolaron structure" is necessary. In fact, during the fabrication of an organic EL device, when a film formed from a charge transport composition is subjected to a firing treatment, the above-mentioned doping reaction is intentionally induced to achieve this. The reason for the presence of the quinoid structure in the polythiophene derivative before the doping reaction is thought to be that the polythiophene derivative undergoes an unintentional oxidation reaction equivalent to the doping reaction during its manufacturing process (particularly, the sulfonation process therein).

[0089] There is a correlation between the amount of the quinoid structure contained in the above polythiophene derivative and the solubility and dispersibility of the polythiophene derivative in an organic solvent. If the amount of the quinoid structure increases, its solubility and dispersibility tend to decrease. Therefore, the introduction of the quinoid structure after forming a film from the charge transport composition does not cause problems. However, if the quinoid structure is excessively introduced into the polythiophene derivative through the above-mentioned unintentional oxidation reaction, it sometimes poses an obstacle to the manufacture of the charge transport composition. For polythiophene derivatives, it is known that the solubility and dispersibility in an organic solvent fluctuate, and one of the reasons is thought to be that the amount of the quinoid structure introduced into the polythiophene through the above-mentioned unintentional oxidation reaction varies depending on the differences in the manufacturing conditions of each polythiophene derivative.

[0090] Therefore, if the above polythiophene derivative is subjected to a reduction treatment using a reducing agent, even if the quinoid structure is excessively introduced into the polythiophene derivative, the quinoid structure is reduced through reduction, and the solubility and dispersibility of the polythiophene derivative in an organic solvent are improved. Thus, it becomes possible to stably manufacture a good charge transport composition that gives a film with excellent homogeneity.

[0091] Regarding the conditions of the reduction treatment, as long as the above quinoid structure can be reduced to appropriately transform it into a non-oxidized structure, that is, the above benzene-type structure (for example, in a polythiophene derivative containing a repeating unit represented by the above formula (1), transforming the quinoid structure represented by the above formula (1') into the structure represented by the above formula (1)), there are no particular limitations. For example, this treatment can be carried out by bringing only the polythiophene derivative and the amine adduct into contact with a reducing agent in the presence or absence of an appropriate solvent.

[0092] Such a reducing agent also has no particular limitations as long as it can be appropriately reduced. For example, ammonia water, hydrazine, etc., which are easily available as commercial products, are appropriate.

[0093] In addition, the amount of the reducing agent varies depending on the type of the reducing agent used, and thus cannot be generally specified. Usually, from the viewpoint of appropriately performing reduction, it is 0.1 part by mass or more, and from the viewpoint of not leaving an excessive reducing agent, it is 10 parts by mass or less, relative to 100 parts by mass of the polythiophene derivative and the amine adduct to be treated.

[0094] As an example of a specific method of the reduction treatment, the polythiophene derivative and the amine adduct are stirred overnight at room temperature in 28% ammonia water. By such a reduction treatment under relatively mild conditions, the solubility and dispersibility of the polythiophene derivative and the amine adduct in an organic solvent are sufficiently improved.

[0095] In the charge transport composition of the present invention, when using the amine adduct of the polythiophene derivative, the above reduction treatment can be carried out before forming the amine adduct or after forming the amine adduct.

[0096] Furthermore, by this reduction treatment, the solubility and dispersibility of the polythiophene derivative or its amine adduct in a solvent change, and as a result, the polythiophene derivative or its amine adduct that was not dissolved in the reaction system at the start of the treatment may dissolve at the end of the treatment. In such a case, by adding the polythiophene derivative or its amine adduct and an incompatible organic solvent (acetone, isopropyl alcohol, etc. in the case of sulfonated polythiophene) to the reaction system to cause precipitation of the polythiophene derivative or its amine adduct, and by using methods such as filtration, the polythiophene derivative or its amine adduct can be recovered.

[0097] The weight average molecular weight of the polythiophene derivative or its amine adduct represented by the formula (1) is preferably 1,000 to 1,000,000, more preferably 5,000 to 100,000, and still more preferably 10,000 to 50,000. By making the weight average molecular weight above the lower limit, good conductivity can be obtained with good reproducibility, and by making it below the upper limit, the solubility in a solvent is improved. It should be noted that the weight average molecular weight is a polystyrene conversion value obtained by gel permeation chromatography.

[0098] Furthermore, the polythiophene derivative or its amine adduct contained in the charge transport composition of the present invention may be a single kind of the polythiophene derivative or its amine adduct containing the repeating unit represented by the formula (1), or two or more kinds.

[0099] In addition, the polythiophene derivative containing the repeating unit represented by the formula (1) can be a commercially available product or a product polymerized by a known method using a thiophene derivative or the like as an initial raw material. In either case, a product refined by a method such as reprecipitation or ion exchange is preferably used. By using the refined product, the characteristics of the organic EL element including the thin film obtained from the composition containing the derivative can be further improved.

[0100] It should be noted that the sulfonation of the conjugated polymer and the sulfonated conjugated polymer (including sulfonated polythiophene) are described in U.S. Patent No. 8,017,241 to Seshadri et al.

[0101] In addition, for sulfonated polythiophene, it is described in International Publication No. 2008 / 073149 and International Publication No. 2016 / 171935.

[0102] In the present invention, at least a part of the polythiophene derivative containing the repeating unit represented by the formula (1) or its amine adduct contained in the charge transporting composition is dissolved in an organic solvent.

[0103] Furthermore, in the present invention, without particular limitation, within the range not impairing the effects of the present invention, as the charge transporting material, a charge transporting material containing a charge transporting compound other than the polythiophene derivative containing the repeating unit represented by the formula (1) or its amine adduct can be used in combination, and it is preferably composed only of the polythiophene derivative containing the repeating unit represented by the formula (1) or its amine adduct.

[0104] Regarding the content of the charge transporting material in the charge transporting composition of the present invention, generally, considering the desired film thickness, viscosity of the composition, etc., it is appropriately determined within the range of 0.05 to 40% by mass, preferably 0.1 to 35% by mass, relative to the whole composition.

[0105] The charge transporting composition of the present invention contains an organosilane compound selected from at least one of a silane containing a fluoroalkyl group and a silane containing a fluoroaryl group.

[0106] As the above-mentioned fluoroalkyl group, groups similar to the fluoroalkyl groups having 1 to 20 carbon atoms exemplified above can be mentioned, preferably fluoroalkyl groups having 1 to 10 carbon atoms, more preferably fluoroalkyl groups having 1 to 8 carbon atoms.

[0107] As the above-mentioned fluoroaryl group, groups in which at least one hydrogen atom of the above-mentioned exemplified aryl group having 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms, is substituted with a fluorine atom can be mentioned, and there is no particular limitation. For example, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2,3-difluorophenyl, 2,4-difluorophenyl, 2,5-difluorophenyl, 2,6-difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl, 2,3,4-trifluorophenyl, 2,3,5-trifluorophenyl, 2,3,6-trifluorophenyl, 2,4,5-trifluorophenyl, 2,4,6-trifluorophenyl, 3,4,5-trifluorophenyl, 2,3,4,5-tetrafluorophenyl, 2,3,4,6-tetrafluorophenyl, 2,3,5,6-tetrafluorophenyl, perfluorophenyl, trifluoromethylphenyl, perfluorotolyl, 2-fluoro-1-naphthyl, 3-fluoro-1-naphthyl, 4-fluoro-1-naphthyl, 6-fluoro-1-naphthyl, 7-fluoro-1-naphthyl, 8-fluoro-1-naphthyl, 4,5-difluoro-1-naphthyl, 5,7-difluoro-1-naphthyl, 5,8-difluoro-1-naphthyl, 5,6,7,8-tetrafluoro-1-naphthyl, heptafluoro-1-naphthyl, 1-fluoro-2-naphthyl, 5-fluoro-2-naphthyl, 6-fluoro-2-naphthyl, 7-fluoro-2-naphthyl, 5,7-difluoro-2-naphthyl and heptafluoro-2-naphthyl can be mentioned.

[0108] As the above-mentioned organosilane compound, it is preferably provided with a fluoroalkyl group or a fluoroaryl group at at least one molecular end, and more preferably provided with a perfluoroalkyl group and a perfluoroaryl group.

[0109] As the silane containing a fluoroalkyl group or the silane containing a fluoroaryl group that can be preferably used in the present invention, silanes containing a fluoroalkyl group or silanes containing a fluoroaryl group represented by the following formula (A1) or (B1) can be mentioned, but are not limited thereto.

[0110] [Chemical formula 8]

[0111]

[0112] In the formula, R 3 are independently a single bond, an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, an ester bond, an ether bond or a carbonyl bond, R 4 and R 5 are independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a trialkylsilyl group having 1 to 10 carbon atoms, X is a perfluoroalkyl group having 1 to 20 carbon atoms or a perfluoroaryl group having 6 to 20 carbon atoms, L is O, S or N, m is 1 or 2, and n is 2 or 3.

[0113] As the alkylene group having 1 to 20 carbon atoms, groups similar to the above-mentioned exemplified alkylene group having 1 to 20 carbon atoms can be mentioned. An alkylene group having 1 to 10 carbon atoms is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and methylene, ethylene and trimethylene are further preferred.

[0114] Examples of the arylene group having 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms, include phenylene, biphenylene, naphthylene, and anthrylene. In the present invention, phenylene is more preferred.

[0115] Examples of the alkyl group having 1 to 20 carbon atoms include the same groups as those exemplified above for the alkyl group having 1 to 20 carbon atoms. An alkyl group having 1 to 10 carbon atoms is preferred, an alkyl group having 1 to 5 carbon atoms is more preferred, and methyl and ethyl are further preferred.

[0116] Examples of the alkoxy group having 1 to 20 carbon atoms include the same groups as those exemplified above for the alkoxy group having 1 to 20 carbon atoms. An alkoxy group having 1 to 10 carbon atoms is preferred, an alkoxy group having 1 to 5 carbon atoms is more preferred, and methoxy and ethoxy are further preferred.

[0117] Examples of the trialkylsilyl group having 1 to 10 carbon atoms include trimethylsilyl, triethylsilyl, tripropylsilyl, tributylsilyl, tripentylsilyl, trihexylsilyl, pentyl-dimethylsilyl, hexyl-dimethylsilyl, octyl-dimethylsilyl, and decyl-dimethylsilyl, in which each alkyl group has 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms. In the present invention, trimethylsilyl and triethylsilyl are preferred.

[0118] Examples of the perfluoroalkyl group having 1 to 20 carbon atoms include groups in which all hydrogen atoms of the alkyl group having 1 to 20 carbon atoms exemplified above are substituted with fluorine atoms. A perfluoroalkyl group having 1 to 10 carbon atoms is preferred, and a perfluoroalkyl group having 1 to 8 carbon atoms is more preferred.

[0119] Examples of the perfluoroaryl group having 6 to 20 carbon atoms include groups in which all hydrogen atoms of the aryl group having 6 to 20 carbon atoms are substituted with fluorine atoms. A perfluoroaryl group having 6 to 12 carbon atoms is preferred, and perfluorophenyl and perfluorotolyl are more preferred.

[0120] L is O, S, or N, and O is preferred.

[0121] m is 1 or 2, and 1 is preferred.

[0122] n is a number corresponding to the valence of L, is 2 or 3, and 2 is preferred.

[0123] Specific examples of the fluoroalkyl group-containing silane or fluoroaryl group-containing silane represented by the formula (A1) or (B1) are listed below, but are not limited thereto.

[0124] The fluoroalkyl group-containing silane represented by the formula (A1-1) is particularly preferred.

[0125] [Chemical formula 9]

[0126]

[0127] [Chemical Formula 10]

[0128]

[0129] [Chemical Formula 11]

[0130]

[0131] Regarding the content of the fluoroalkyl group-containing silane and / or fluoroaryl group-containing silane in the charge transport composition of the present invention, in terms of the mass of the solid component, generally, expressed as the total of the fluoroalkyl group-containing silane and the fluoroaryl group-containing silane, it is about 0.1 to 50% by mass. Considering the balance such as the improvement of the flatness of the obtained thin film and the suppression of the decrease in charge transport properties, it is preferably about 0.5 to 40% by mass, more preferably about 0.8 to 30% by mass, and further preferably about 1 to 20% by mass.

[0132] The above-mentioned organosilane compounds used in the present invention can be synthesized by known methods or obtained as commercially available products. Examples of such commercially available products include KBM-7103 (manufactured by Shin-Etsu Chemical Co., Ltd.), SIT8365.0 (manufactured by Gelest, Inc.), SIT8618.0 (manufactured by Gelest, Inc.), SIT8356.0 (manufactured by Gelest, Inc.), SIT8343.0 (manufactured by Gelest, Inc.), SIT8345.0 (manufactured by Gelest, Inc.), SIP6716.73 (manufactured by Gelest, Inc.), SIP6716.6 (manufactured by Gelest, Inc.), SIN6597.7 (manufactured by Gelest, Inc.), SIT8176.0 (manufactured by Gelest, Inc.), SIH5841.5 (manufactured by Gelest, Inc.), SIN6597.65 (manufactured by Gelest, Inc.), SIT8175.0 (manufactured by Gelest, Inc.), SIH5841.2 (manufactured by Gelest, Inc.), SIB1710.0 (manufactured by Gelest, Inc.), etc., but are not limited to these.

[0133] Furthermore, in the charge transport composition of the present invention, in addition to the fluoroalkyl group-containing silane and the fluoroaryl group-containing silane, in order to adjust the film physical properties, etc. of the obtained charge transport thin film, other alkoxysilanes and siloxane-based materials can be used in combination.

[0134] The other alkoxysilanes and / or siloxane-based materials can be a single type or two or more types.

[0135] Examples of such other alkoxysilanes include tetraalkoxysilanes such as tetraethoxysilane and tetramethoxysilane; trialkoxysilanes such as phenyltriethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, and dimethyldiethoxysilane; and dialkoxysilanes such as dimethyldimethoxysilane as tetraalkoxysilanes.

[0136] Examples of the siloxane-based material include products obtained by hydrolyzing a silane containing a fluoroalkyl group and / or a silane containing a fluoroaryl group and / or other silanes. Specific examples thereof include polysiloxanes such as poly(tetraethoxysilane) and poly(phenylethoxysilane).

[0137] From the viewpoint of compatibility with a silane containing a fluoroalkyl group and a silane containing a fluoroaryl group, tetraalkoxysilanes, trialkoxysilanes, and dialkoxysilanes are preferred.

[0138] When using the above-described other alkoxysilanes, their content is not particularly limited as long as it is an amount that does not impair the effects of the present invention and exhibits the above-described effects, and is usually 50% by mass or less relative to the total mass of the silane containing a fluoroalkyl group and the silane containing a fluoroaryl group.

[0139] The charge transport composition of the present invention contains metal oxide nanoparticles. The term "nanoparticles" means fine particles having an average particle diameter of the primary particles in the nanometer range (typically 500 nm or less). The term "metal oxide nanoparticles" means metal oxides formed into nanoparticles.

[0140] The primary particle size of the metal oxide nanoparticles used in the present invention is not particularly limited as long as it is in the nanometer size. If a film having excellent flatness is to be obtained with good reproducibility, it is preferably 2 to 150 nm, more preferably 3 to 100 nm, and further preferably 5 to 50 nm. It should be noted that the particle size is the measured value of the nitrogen adsorption isotherm obtained by the BET method.

[0141] The metal constituting the metal oxide nanoparticles in the present invention includes semimetals in addition to metals in the ordinary sense.

[0142] The metal in the ordinary sense is not particularly limited, and it is preferably one or more selected from tin (Sn), titanium (Ti), aluminum (Al), zirconium (Zr), zinc (Zn), niobium (Nb), tantalum (Ta), and tungsten (W).

[0143] On the other hand, a so-called semi-metal means an element whose chemical and / or physical properties are intermediate between those of a metal and a non-metal. A general definition of a semi-metal has not been established. In the present invention, six elements, namely boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te), are defined as semi-metals. These semi-metals can be used alone, or two or more of them can be used in combination. Additionally, they can also be used in combination with metals in the ordinary sense.

[0144] The metal oxide nanoparticles used in the present invention preferably contain oxides of one or more metals selected from boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), tin (Sn), titanium (Ti), aluminum (Al), zirconium (Zr), zinc (Zn), niobium (Nb), tantalum (Ta), and tungsten (W). It should be noted that when the metals are combined in two or more kinds, the metal oxide can be a mixture of oxides of individual metals, or a composite oxide containing multiple metals.

[0145] Specific examples of the metal oxide include B 2 O 3 、B 2 O、SiO 2 、SiO、GeO 2 、GeO、As 2 O 4 、As 2 O 3 、As 2 O 5 、Sb 2 O 3 、Sb 2 O 5 、TeO 2 、SnO 2 、ZrO 2 、Al 2 O 3 、ZnO, etc. Preferably, B 2 O 3 、B 2 O、SiO 2 、SiO、GeO 2 、GeO、As 2 O 4 、As 2 O 3 、As 2 O 5 、SnO 2 、SnO、Sb 2 O 3 、TeO 2 and their mixtures, more preferably SiO 2 .

[0146] The metal oxide nanoparticles contained in the charge transporting composition of the present invention may be a single type or two or more types.

[0147] The metal oxide nanoparticles contained in the charge transporting composition of the present invention are preferably uniformly dispersed in the composition.

[0148] Furthermore, the above-mentioned metal oxide nanoparticles may contain one or more organic capping groups. The organic capping group may be reactive or non-reactive. Examples of the reactive organic capping group include organic capping groups that can be crosslinked using ultraviolet light or a radical initiator.

[0149] In the charge transporting composition of the present invention, the content of the metal oxide nanoparticles is not particularly limited. From the viewpoints of suppressing the aggregation of particles in the charge transporting material and obtaining a film with excellent flatness with good reproducibility, etc., it is preferably 40 to 95% by mass, more preferably 50 to 95% by mass, and most preferably 60 to 90% by mass based on the mass of the solid components.

[0150] In particular, in the present invention, by using a metal oxide nanoparticle sol in which metal oxide nanoparticles are dispersed, a composition in which the metal oxide nanoparticles are uniformly dispersed can be prepared with good reproducibility.

[0151] That is, compared with mixing the metal oxide nanoparticles themselves with a charge transporting material, etc. in a solvent to disperse them, by preparing a metal oxide nanoparticle sol in advance and mixing the sol with a mixture obtained by dissolving or dispersing the charge transporting material, etc. in a solvent, a charge transporting composition in which the metal oxide nanoparticles are uniformly dispersed can be manufactured with good reproducibility.

[0152] Such a metal oxide nanoparticle sol can use commercially available products, and can also be prepared by a known method using a solvent and metal oxide nanoparticles that the charge transporting composition of the present invention may contain.

[0153] In particular, when preparing the charge transporting composition of the present invention, it is preferable to use a silica sol in which SiO 2 nanoparticles are dispersed in a dispersion medium.

[0154] There is no particular limitation on the silica sol, and it can be appropriately selected and used from known silica sols.

[0155] Commercially available silica sols are usually in the form of a dispersion liquid. Examples of commercially available silica sols include SiO 2Products of dispersion of nanoparticles in various solvents such as water, methanol, methyl ethyl ketone, methyl isobutyl ketone, N,N-dimethylacetamide, ethylene glycol, isopropanol, methanol, ethylene glycol monopropyl ether, cyclohexanone, ethyl acetate, toluene, propylene glycol monomethyl ether acetate, etc.

[0156] In particular, in the present invention, the dispersion medium is preferably a silica sol of an alcohol solvent or water, and more preferably a silica sol of an alcohol solvent. As the alcohol solvent, water-soluble alcohols are preferred, and methanol, 2-propanol, and ethylene glycol are more preferred.

[0157] Specific examples of commercially available silica sols include water-dispersed silica sols such as SNOWTEX (registered trademark) ST-O, ST-OS, ST-O-40, ST-OL manufactured by Nissan Chemical Industries, Ltd., and SILICADOL 20, 30, 40 manufactured by Nippon Chemical Co., Ltd.; organic silica sols such as methanol silica sols, MA-ST-M, MA-ST-L, IPA-ST, IPA-ST-L, IPA-ST-ZL, EG-ST manufactured by Nissan Chemical Industries, Ltd., etc., but are not limited to these.

[0158] In addition, the concentration of the silica sol is not particularly limited, preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and further preferably 15 to 30% by mass.

[0159] SiO in the silica sol 2 The concentration of the nanoparticles is usually about 5 to 50% by mass. When mixing a mixture obtained by dissolving or dispersing the silica sol and a charge transporting substance, etc. in a solvent, depending on the type of the solvent contained in the mixture, sometimes SiO 2 nanoparticles aggregate. Therefore, this should be noted when preparing the composition. 2

[0160] The charge transporting composition of the present invention contains an organic solvent.

[0161] As such an organic solvent, as long as it disperses or dissolves components other than the organic solvents used in the charge transporting composition of the present invention, there is no particular limitation.

[0162] As specific examples, for instance, it can be appropriately selected and used from aromatic or halogenated aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, chlorobenzene, etc.; aliphatic hydrocarbons such as n-heptane, n-hexane, cyclohexane, etc.; ether solvents such as diethyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, etc.; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; ester solvents such as ethyl acetate, n-hexyl acetate, ethyl lactate, γ-butyrolactone, etc.; halogenated hydrocarbon solvents such as dichloromethane, dichloromethane, 1,2-dichloroethane, chloroform, etc.; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc.; alcohol solvents such as methanol, ethanol, isopropanol, n-propanol, cyclohexanol, diacetone alcohol, 2-phenoxyethanol, etc.; glycol ether solvents such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol diglycidyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, etc.; glycol solvents such as ethylene glycol, propylene glycol, hexylene glycol, 1,3-octanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, etc.

[0163] It should be noted that these organic solvents can be used individually or in combination of two or more.

[0164] In the charge transport composition of the present invention, as the solvent, water can also be included. In terms of the content of water, from the viewpoint of reproducibly obtaining an organic EL element with excellent durability, it is preferably 10% by mass or less of all solvents, more preferably 5% by mass or less, and most preferably only organic solvents are used as the solvent. It should be noted that "only using organic solvents" in this case means that only organic solvents are used as the solvent, and it does not deny the existence of "water" contained in trace amounts in the used organic solvents, solid components, etc.

[0165] In the charge transport composition of the present invention, depending on the use of the obtained film, a dopant substance can be included for the purpose of improving its charge transport ability, etc.

[0166] As the dopant substance, as long as it is soluble in at least one solvent used in the composition, there is no particular limitation, and both inorganic dopant substances and organic dopant substances can be used.

[0167] As the inorganic dopant substance, examples include heteropolyacids such as phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, phosphotungstomolybdic acid, silicotungstic acid, etc.; inorganic strong acids such as hydrogen chloride, sulfuric acid, nitric acid, phosphoric acid, etc.; aluminum(III) chloride (AlCl 3 )、titanium(IV) chloride (TiCl4 ) boron tribromide (BBr 3 ) boron trifluoride ether complex (BF 3 ·OEt 2 ) iron(III) chloride (FeCl 3 ) copper(II) chloride (CuCl 2 ) antimony(V) pentachloride (SbCl 5 ) arsenic(V) pentafluoride (AsF 5 ) phosphorus pentafluoride (PF 5 ) and other metal halides such as Cl 2 , Br 2 , I 2 , ICl, ICl 3 , IBr, IF 4 and other halogens etc.

[0168] In addition, as organic dopant substances, tetracyanoquinodimethane (TCNQ) derivatives such as 7,7,8,8 - tetracyanoquinodimethane (TCNQ), 2 - fluoro - 7,7,8,8 - tetracyanoquinodimethane, 2,5 - difluoro - 7,7,8,8 - tetracyanoquinodimethane can be cited; halogenated tetracyanoquinodimethane (halogenated TCNQ) derivatives such as tetrafluoro - 7,7,8,8 - tetracyanoquinodimethane (F4TCNQ), tetrachloro - 7,7,8,8 - tetracyanoquinodimethane, 2 - fluoro - 7,7,8,8 - tetracyanoquinodimethane, 2 - chloro - 7,7,8,8 - tetracyanoquinodimethane, 2,5 - difluoro - 7,7,8,8 - tetracyanoquinodimethane, 2,5 - dichloro - 7,7,8,8 - tetracyanoquinodimethane; benzoquinone derivatives such as tetrachloro - 1,4 - benzoquinone (tetrachlorobenzoquinone), 2,3 - dichloro - 5,6 - dicyano - 1,4 - benzoquinone (DDQ); arylsulfonic acid compounds such as benzenesulfonic acid, toluenesulfonic acid, p - styrenesulfonic acid, 2 - naphthalenesulfonic acid, 4 - hydroxybenzenesulfonic acid, 5 - sulfosalicylic acid, p - dodecylbenzenesulfonic acid, dihexylbenzenesulfonic acid, 2,5 - dihexylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, 6,7 - dibutyl - 2 - naphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, 3 - dodecyl - 2 - naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 4 - hexyl - 1 - naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2 - octyl - 1 - naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 7 - hexyl - 1 - naphthalenesulfonic acid, 6 - hexyl - 2 - naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, 2,7 - dinonyl - 4 - naphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, 2,7 - dinonyl - 4,5 - naphthalenedisulfonic acid, 1,4 - benzodioxanedisulfonic acid derivatives described in International Publication No. 2005 / 000832, arylsulfonic acid derivatives described in International Publication No. 2006 / 025342, dinonylnaphthalenesulfonic acid derivatives described in Japanese Patent Application Laid - Open No. 2005 - 108828, etc.; aromatic sulfocompounds such as polystyrenesulfonic acid; non - aromatic sulfocompounds such as 10 - camphorsulfonic acid, etc.

[0169] These inorganic and organic dopant substances can be used individually, one type at a time, or two or more types can be used in combination.

[0170] Examples of the arylsulfonic acid compounds preferably used as the dopant substances in the present invention include arylsulfonic acid compounds represented by formula (H1) or (H2).

[0171] [Chemical formula 12]

[0172]

[0173] A 1 represents O or S, preferably O.

[0174] A 2 represents a naphthalene ring or an anthracene ring, preferably a naphthalene ring.

[0175] A 3 represents a 2- to 4-valent perfluorobiphenyl group, and s represents the number of bonds of A 1 to A 3 is an integer satisfying 2 ≤ s ≤ 4, preferably A 3 is perfluorobenzene-4,4'-diyl, and s is 2.

[0176] q represents the number of sulfonic acid groups bonded to A 2 is an integer satisfying 1 ≤ q ≤ 4, and most preferably 2.

[0177] A 4 ~A 8 each independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, or a halogenated alkenyl group having 2 to 20 carbon atoms, and at least three of A 4 ~A 8 are halogen atoms.

[0178] Examples of the halogenated alkyl group having 1 to 20 carbon atoms include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4,4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, 1,1,2,2,3,3,4,4,4-nonafluorobutyl, and the like.

[0179] Examples of the halogenated alkenyl group having 2 to 20 carbon atoms include perfluorovinyl, perfluoropropenyl (allyl), perfluorobutenyl, and the like.

[0180] In addition, examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms are the same as those described above, and as the halogen atom, a fluorine atom is preferred.

[0181] Among these, A 4 ~A 8 is preferably a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms, and at least 3 of A 4 ~A 8 are fluorine atoms. More preferably, it is a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkenyl group having 2 to 5 carbon atoms, and at least 3 of A 4 ~A 8 are fluorine atoms. Further preferably, it is a hydrogen atom, a fluorine atom, a cyano group, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkenyl group having 1 to 5 carbon atoms, and A 4 , A 5 and A 8 are fluorine atoms.

[0182] It should be noted that a perfluoroalkyl group means a group in which all hydrogen atoms of an alkyl group are replaced by fluorine atoms, and a perfluoroalkenyl group means a group in which all hydrogen atoms of an alkenyl group are replaced by fluorine atoms.

[0183] r represents the number of sulfonic acid groups bonded to the naphthalene ring, and is an integer satisfying 1 ≤ r ≤ 4. Preferably, it is 2 to 4, and most preferably 2.

[0184] When an organic compound is used as a dopant substance, if the solubility in an organic solvent is considered, its molecular weight is preferably 3,000 or less, and more preferably 2,500 or less.

[0185] In particular, there is no particular limitation on the molecular weight of the arylsulfonic acid compound used as a dopant substance. If the solubility in an organic solvent is considered, it is preferably 2,000 or less, and more preferably 1,500 or less.

[0186] In the present invention, examples of the arylsulfonic acid compound that can be preferably used include the following compounds, but are not limited thereto.

[0187] [Chemical formula 13]

[0188]

[0189] Regarding the charge transporting composition of the present invention, in order to improve the dispersibility, solubility, etc. of the polythiophene derivative or its amine adduct, an amine compound may be included.

[0190] Such an amine compound is not particularly limited as long as it is soluble in at least one solvent used in the composition, and may be a single one or two or more.

[0191] As specific examples of primary amine compounds, there may be mentioned monoalkylamine compounds such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-ethylhexylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-nonadecylamine, n-eicosylamine, etc.; monoarylamine compounds such as aniline, methylaniline, 1-naphthylamine, 2-naphthylamine, 1-anthrylamine, 2-anthrylamine, 9-anthrylamine, 1-phenanthrylamine, 2-phenanthrylamine, 3-phenanthrylamine, 4-phenanthrylamine, 9-phenanthrylamine, etc.

[0192] As specific examples of secondary amine compounds, there may be mentioned dialkylamine compounds such as N-ethylmethylamine, N-methyl-n-propylamine, N-methylisopropylamine, N-methyl-n-butylamine, N-methylsec-butylamine, N-methyltert-butylamine, N-methylisobutylamine, diethylamine, N-ethyl-n-propylamine, N-ethylisopropylamine, N-ethyl-n-butylamine, N-ethylsec-butylamine, N-ethyltert-butylamine, dipropylamine, N-n-propylisopropylamine, N-n-propyl-n-butylamine, N-n-propylsec-butylamine, diisopropylamine, N-n-butylisopropylamine, N-tert-butylisopropylamine, bis(n-butyl)amine, bis(sec-butyl)amine, diisobutylamine, aziridine, 2-methylaziridine, 2,2-dimethylaziridine, azetidine, 2-methylazetidine, pyrrolidine, 2-methylpyrrolidine, 3-methylpyrrolidine, 2,5-dimethylpyrrolidine, piperidine, 2,6-dimethylpiperidine, 3,5-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, hexamethyleneimine, heptamethyleneimine, octamethyleneimine, etc.; diarylamine compounds such as diphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, 1,1'-dinaphthylamine, 2,2'-dinaphthylamine, 1,2'-dinaphthylamine, carbazole, 7H-benzo[c]carbazole, 11H-benzo[a]carbazole, 7H-dibenzo[c,g]carbazole, 13H-dibenzo[a,i]carbazole, etc.; alkylarylamine compounds such as N-methylaniline, N-ethylaniline, N-n-propylaniline, N-isopropylaniline, N-n-butylaniline, N-sec-butylaniline, N-isobutylaniline, N-methyl-1-naphthylamine, N-ethyl-1-naphthylamine, N-n-propyl-1-naphthylamine, indoline, isoindoline, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroisoquinoline, etc.

[0193] As specific examples of the tertiary amine compound, N,N-dimethylethylamine, N,N-dimethyl-n-propylamine, N,N-dimethylisopropylamine, N,N-dimethyl-n-butylamine, N,N-dimethyl-sec-butylamine, N,N-dimethyl-tert-butylamine, N,N-dimethylisobutylamine, N,N-diethylmethylamine, N-methyl-di(n-propyl)amine, N-methyl-diisopropylamine, N-methyl-di(n-butyl)amine, N-methyl-diisobutylamine, triethylamine, N,N-diethyl-n-butylamine, N,N-diisopropylethylamine, N,N-di(n-butyl)ethylamine, tri(n-propyl)amine, tri(isopropyl)amine, tri(n-butyl)amine, tri(isobutyl)amine, 1-methylazetidine, 1-methylpyrrolidine, 1-methylpiperidine and other trialkylamine compounds can be cited; triphenylamine and other triarylamine compounds; N-methyldiphenylamine, N-ethyldiphenylamine, 9-methylcarbazole, 9-ethylcarbazole and other alkyldiarylamine compounds; N,N-diethylaniline, N,N-di(n-propyl)aniline, N,N-di(isopropyl)aniline, N,N-di(n-butyl)aniline and other dialkylarylamine compounds, etc.

[0194] In particular, when the charge transporting composition of the present invention contains an amine compound, since it has excellent ability to improve the dispersibility and solubility of the polythiophene derivative or its amine adduct used in the present invention, the amine compound preferably contains a primary amine compound, and preferably contains a monoalkylamine, particularly a monoalkylamine having 2 or more and 20 or less carbon atoms.

[0195] When the charge transporting composition of the present invention contains an amine compound, in terms of its content, it is usually 200% by mass or less relative to the polythiophene derivative or its amine adduct used in the present invention, and in order to obtain the above effects produced by the amine compound, it is preferably 50% by mass or more.

[0196] The viscosity of the charge transporting composition of the present invention is usually 1 to 50 mPa·s at 25°C, and the surface tension is usually 20 to 50 mN / m at 25°C.

[0197] The viscosity and surface tension of the charge transporting composition of the present invention can be adjusted by changing the types of organic solvents used, their ratios, the solid content concentration, etc. in consideration of various factors such as the coating method to be used and the desired film thickness.

[0198] In addition, the solid content concentration of the charge transporting composition in the present invention is appropriately set in consideration of the viscosity and surface tension of the composition, the thickness of the produced thin film, etc., and is usually about 0.1 to 15.0% by mass. From the viewpoint of suppressing the aggregation of charge transporting substances and metal oxide nanoparticles in the composition, it is preferably 10.0% by mass or less, more preferably 8.0% by mass or less, and further preferably 5% by mass or less.

[0199] The charge transport composition of the present invention can be produced by mixing a polythiophene derivative or its amine adduct containing a repeating unit represented by formula (1), an organosilane compound selected from at least one of a silane containing a fluoroalkyl group and a silane containing a fluoroaryl group, metal oxide nanoparticles, and an organic solvent.

[0200] There is no particular limitation on the mixing order. As an example of a method for easily and reproducibly producing the charge transport composition of the present invention, there can be mentioned a method in which a polythiophene derivative or its amine adduct containing a repeating unit represented by formula (1), a silane containing a fluoroalkyl group, a silane containing a fluoroaryl group, etc. are mixed with an organic solvent to obtain a mixture, and a metal oxide nanoparticle sol prepared in advance is added to this mixture; a method in which this mixture is added to a sol of metal oxide nanoparticles prepared in advance. In this case, if necessary, an organic solvent can be further added finally, or in the case where a part of the components that are relatively easily soluble in the solvent is not contained in the mixture, it can be added finally. From the viewpoint of suppressing aggregation and separation of the constituent components and reproducibly preparing a charge transport composition with excellent uniformity, it is preferable to separately prepare a metal oxide nanoparticle sol in a good dispersion state or a good dissolution state and a mixture containing other components, mix the two, and then stir well. It should be noted that attention should be paid to the fact that metal oxide nanoparticles, polythiophene derivatives or their amine adducts may aggregate or precipitate during mixing depending on the type and amount of the solvent mixed together. In addition, in the case of preparing a composition using a sol, attention should also be paid to the following point: it is necessary to determine the concentration of the sol and its usage amount so that the metal oxide nanoparticles in the finally obtained composition become the desired amount.

[0201] In the preparation of the composition, heating can be appropriately carried out within the range where the components are not decomposed or deteriorated.

[0202] In the present invention, for the charge transport composition, in order to reproducibly obtain a film with higher flatness, it can be filtered using a submicron filter or the like during the intermediate stage of manufacturing the composition or after mixing all the components.

[0203] By coating and firing the charge transport composition of the present invention described above on a substrate, a charge transport film of the present invention can be formed on the substrate.

[0204] There is no particular limitation on the coating method of the composition, and examples include an immersion method, a spin coating method, a transfer printing method, a roll coating method, a brush coating, an inkjet method, a spraying method, a slot coating method, etc. It is preferable to adjust the viscosity and surface tension of the composition according to the coating method.

[0205] In addition, when using the charge transport composition of the present invention, the firing atmosphere is not particularly limited. Not only in an air atmosphere, but also in an inert gas such as nitrogen or in a vacuum, a film having a uniform film formation surface and high charge transport properties can be obtained.

[0206] Regarding the firing temperature, it is appropriately set within a range of about 100 to 260 °C in consideration of the use of the obtained film, the degree of charge transport properties imparted to the obtained film, the type of solvent, the boiling point, etc. When the obtained film is used as a hole injection layer of an organic EL element, it is preferably about 140 to 250 °C, more preferably about 145 to 240 °C.

[0207] Furthermore, at the time of firing, in order to exhibit higher uniform film formation properties and react on the substrate, a temperature change of two or more stages can be given, and heating can be performed using appropriate equipment such as a hot plate or an oven.

[0208] The film thickness of the charge transport film is not particularly limited. When it is used as a hole injection layer or a hole transport layer of an organic EL element, it is usually 3 to 300 nm, preferably 5 to 200 nm. As a method for changing the film thickness, there are methods such as changing the solid content concentration in the composition and changing the amount of the composition on the substrate during coating.

[0209] The organic EL element of the present invention has a pair of electrodes, and between these electrodes, there is a functional film composed of the charge transport film of the present invention described above.

[0210] As a representative configuration of the organic EL element, the following (a) to (f) can be cited, but it is not limited to these. It should be noted that in the following configurations, an electron blocking layer etc. can be provided between the light emitting layer and the anode as needed, and a hole blocking layer etc. can be provided between the light emitting layer and the cathode. In addition, the hole injection layer, the hole transport layer, or the hole injection transport layer can also function as an electron blocking layer etc., and the electron injection layer, the electron transport layer, or the electron injection transport layer can also function as a hole blocking layer etc. Furthermore, as needed, an arbitrary functional layer can be provided between each layer.

[0211] (a) Anode / Hole injection layer / Hole transport layer / Light emitting layer / Electron transport layer / Electron injection layer / Cathode

[0212] (b) Anode / Hole injection layer / Hole transport layer / Light emitting layer / Electron injection transport layer / Cathode

[0213] (c) Anode / Hole injection transport layer / Light emitting layer / Electron transport layer / Electron injection layer / Cathode

[0214] (d) Anode / Hole injection transport layer / Light emitting layer / Electron injection transport layer / Cathode

[0215] (e) Anode / Hole injection layer / Hole transport layer / Light-emitting layer / Cathode

[0216] (f) Anode / Hole injection and transport layer / Light-emitting layer / Cathode

[0217] "Hole injection layer", "hole transport layer" and "hole injection and transport layer" are layers formed between the light-emitting layer and the anode, and have the function of transporting holes from the anode to the light-emitting layer. When only one layer of hole-transporting material is provided between the light-emitting layer and the anode, it is the "hole injection and transport layer". When two or more layers of hole-transporting material are provided between the light-emitting layer and the anode, the layer close to the anode is the "hole injection layer", and the other layers are the "hole transport layer". In particular, the hole injection (transport) layer uses a thin film that is excellent not only in hole acceptability from the anode but also in hole injection property to the hole transport (light-emitting) layer.

[0218] "Electron injection layer", "electron transport layer" and "electron injection and transport layer" are layers formed between the light-emitting layer and the cathode, and have the function of transporting electrons from the cathode to the light-emitting layer. When only one layer of electron-transporting material is provided between the light-emitting layer and the cathode, it is the "electron injection and transport layer". When two or more layers of electron-transporting material are provided between the light-emitting layer and the cathode, the layer close to the cathode is the "electron injection layer", and the other layers are the "electron transport layer".

[0219] "Light-emitting layer" is an organic layer having a light-emitting function. In the case of an doping system, it contains a host material and a dopant material. At this time, the host material mainly has the functions of promoting the recombination of electrons and holes and confining excitons within the light-emitting layer, and the dopant material has the function of efficiently emitting light from the excitons obtained by recombination. In the case of a phosphorescent element, the host material mainly has the function of confining the excitons generated by the dopant within the light-emitting layer.

[0220] The charge-transporting thin film made from the charge-transporting composition of the present invention can be used as a functional layer formed between the anode and the light-emitting layer in an organic EL element, and is preferably used for the hole injection layer, hole transport layer, hole injection and transport layer, and more preferably for the hole injection layer.

[0221] As the materials and manufacturing methods when using the charge-transporting composition of the present invention to manufacture an organic EL element, the following materials and manufacturing methods can be cited, but are not limited to these.

[0222] An example of a method for manufacturing an OLED element having a hole injection layer composed of a film obtained from the above-described charge transport composition is as follows. Further, for the electrodes, it is preferable to perform cleaning using alcohol, pure water, etc. and surface treatment such as UV ozone treatment and oxygen-plasma treatment in a range that does not cause adverse effects on the electrodes in advance.

[0223] On the anode substrate, using the above method, a hole injection layer is formed using the above charge transport composition. It is introduced into a vacuum evaporation apparatus, and a hole transport layer, a light-emitting layer, an electron transport layer / hole blocking layer, an electron injection layer, and a cathode metal are sequentially evaporated. Alternatively, in this method, instead of forming the hole transport layer and the light-emitting layer by evaporation, a composition for forming a hole transport layer containing a hole-transporting polymer and a composition for forming a light-emitting layer containing a light-emitting polymer are used, and these layers are formed by a wet method. Further, if necessary, an electron blocking layer can be provided between the light-emitting layer and the hole transport layer.

[0224] Examples of the anode material include transparent electrodes represented by indium tin oxide (ITO) and indium zinc oxide (IZO), metal anodes composed of metals represented by aluminum or their alloys, etc., and anode materials preferably subjected to a planarization treatment. Poly(thiophene) derivatives and polyaniline derivatives having high charge transport properties can also be used.

[0225] Further, examples of other metals constituting the metal anode include gold, silver, copper, indium, their alloys, etc., but are not limited thereto.

[0226] Examples of the material for forming the hole transport layer include triarylamines such as (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spiro dimer, N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine (α-NPD), 4,4',4''-tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), 4,4',4''-tris[1-naphthyl(phenyl)amino]triphenylamine (1-TNATA), etc., and oligothiophenes such as 5,5''-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2''-terthiophene (BMA-3T).

[0227] Examples of materials for forming the light-emitting layer include low-molecular-weight light-emitting materials such as metal complexes such as aluminum complexes of 8-hydroxyquinoline, metal complexes of 10-hydroxybenzo[h]quinoline, styrylbiphenyl derivatives, styrylarylene derivatives, metal complexes of (2-hydroxyphenyl)benzothiazole, and silole derivatives; systems in which a light-emitting material and an electron-transporting material are mixed in high-molecular-weight compounds such as poly(p-phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly(3-alkylthiophene), and polyvinylcarbazole, etc., but are not limited to these.

[0228] In addition, in the case of forming the light-emitting layer by vapor deposition, co-vapor deposition with a light-emitting dopant is possible. Examples of the light-emitting dopant include metal complexes such as tris(2-phenylpyridine)iridium(III) (Ir(ppy) 3 ), etc., tetracene derivatives such as rubrene, quinacridone derivatives, condensed polycyclic aromatic rings such as perylene, etc., but are not limited to these.

[0229] Examples of materials for forming the electron-transporting layer / hole-blocking layer include oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, pyrimidine derivatives, etc., but are not limited to these.

[0230] Examples of materials for forming the electron-injecting layer include metal oxides such as lithium oxide (Li 2 O), magnesium oxide (MgO), aluminum oxide (Al 2 O 3 ), etc., metal fluorides such as lithium fluoride (LiF), sodium fluoride (NaF), etc., but are not limited to these.

[0231] Examples of the cathode material include aluminum, magnesium-silver alloy, aluminum-lithium alloy, etc., but are not limited to these.

[0232] Examples of materials for forming the electron-blocking layer include tris(phenylpyrazole)iridium, etc., but are not limited thereto.

[0233] Examples of hole-transporting polymers include poly[(9,9-dihexylfluorene-2,7-diyl)-co-(N,N'-bis{4-butylphenyl}-1,4-diaminophenylene)], poly[(9,9-dioctylfluorene-2,7-diyl)-co-(N,N'-bis{4-butylphenyl}-1,1'-biphenyl-4,4-diamine)], poly[(9,9-bis{1'-penten-5'-yl}fluorene-2,7-diyl)-co-(N,N'-bis{4-butylphenyl}-1,4-diaminophenylene)], poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] capped with polysilsesquioxane, poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-butylphenyl))diphenylamine)], and the like.

[0234] Examples of light-emitting polymers include polyfluorene derivatives such as poly(9,9-dialkylfluorene) (PDAF), poly(phenylenevinylene) derivatives such as poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV), poly(thiophene) derivatives such as poly(3-alkylthiophene) (PAT), polyvinylcarbazole (PVCz), and the like.

[0235] The materials constituting the anode, the cathode, and the layers formed therebetween vary depending on whether the device to be manufactured has a bottom-emission structure or a top-emission structure. Therefore, the materials are appropriately selected in consideration of this point.

[0236] Generally, in a device with a bottom-emission structure, a transparent anode is used on the substrate side, and light is extracted from the substrate side. In a device with a top-emission structure, a reflective anode made of metal is used, and light is extracted from the transparent electrode (cathode) side opposite to the substrate side. Therefore, for example, as the anode material, a transparent anode such as ITO is used when manufacturing a device with a bottom-emission structure, and a reflective anode such as Al / Nd is used when manufacturing a device with a top-emission structure.

[0237] Regarding the organic EL device of the present invention, in order to prevent deterioration of characteristics, it is sealed together with a water scavenger or the like according to a conventional method as needed.

[0238] As described above, the charge-transporting composition of the present invention is preferably used for forming a hole injection layer or a hole transport layer of an organic EL device. In addition, it can also be used for forming a charge-transporting thin film in electronic devices such as an organic photoelectric conversion device, an organic thin-film solar cell, an organic perovskite photoelectric conversion device, an organic integrated circuit, an organic field-effect transistor, an organic thin-film transistor, an organic light-emitting transistor, an organic optical detector, an organic photoreceptor, an organic electrochromic element, a light-emitting electrochemical cell, a quantum dot light-emitting diode, a quantum laser, an organic laser diode, and an organic plasmonic light-emitting element.

[0239] Example

[0240] Examples and comparative examples are listed below to illustrate the present invention more specifically, but the present invention is not limited to the following examples. It should be noted that the devices used are as described below.

[0241] (1) Substrate cleaning: Manufactured by Choshu Sangyo Co., Ltd., substrate cleaning device (reduced-pressure plasma method)

[0242] (2) Coating of the composition: Manufactured by Mikasa Co., Ltd., spin coater MS-A100

[0243] (3) Film thickness measurement: Manufactured by Kosaka Laboratory Ltd., fine shape measuring instrument SURFCORDER ET-4000

[0244] (4) Fabrication of EL element: Manufactured by Choshu Sangyo Co., Ltd., multi-functional evaporation device system C-E2L1G1-N

[0245] (5) Measurement of brightness etc. of EL element: Manufactured by Tech World Co., Ltd., I-V-L measurement system

[0246] [1] Synthesis of compound

[0247] [Synthesis Example 1] Synthesis of polythiophene derivative

[0248] 500 g of an aqueous dispersion of a polymer having a repeating unit containing the repeating unit represented by the above formula (1a), i.e., a polythiophene derivative (concentration 0.6% by mass), was mixed with 0.9 g of triethylamine, and the resulting mixture was dried to dryness by rotary evaporation. Then, the obtained dried product was further dried overnight in a vacuum oven at 50 °C to obtain 4 g of a polythiophene derivative A in which an amine was added to a sulfonic acid group.

[0249] [2] Preparation of charge transport composition

[0250] [Example 1-1]

[0251] 0.030 g of polythiophene derivative A and 0.048 g of 2-ethylhexylamine (2-EHA) were mixed with 0.941 g of ethylene glycol (EG) and 1.930 g of diethylene glycol (DEG), and the mixture was stirred at 80 °C for 1 hour using a hot stirrer. 0.965 g of 2-phenoxyethanol (2-BOE) and 4.826 g of triethylene glycol dimethyl ether (TEGDME) were added to the resulting mixture. To this was added SiO containing metal oxide nanoparticles 2The dispersion medium was 1.244 g of silicone sol EG-ST (manufactured by Nissan Chemical Industries, Ltd., 20.5% by mass, the same hereinafter) with ethylene glycol, 0.015 g of the organosilane compound represented by the above formula (A1-1) (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-7103). After stirring, the resulting mixture was filtered through a PP syringe filter with a pore size of 0.2 μm to prepare a charge transport composition.

[0252] [Example 1-2]

[0253] First, an ethylene glycol solution containing 10% by mass of the arylsulfonic acid (arylsulfonic acid B) represented by the above formula (b-1) was prepared. For the preparation of the solution, a hot stirrer was used and stirred at 400 rpm and 50 °C for 1 hour.

[0254] Next, another container was prepared, 0.030 g of polythiophene derivative A and 0.048 g of 2-EHA were mixed with 0.788 g of EG and 1.930 g of DEG, and stirred at 80 °C for 1 hour using a hot stirrer. 0.965 g of 2-BOE and 4.826 g of TEGDME were added to the resulting mixture and stirred. 0.300 g of a 10% by mass ethylene glycol solution of arylsulfonic acid B, 1.098 g of EG-ST, and 0.015 g of KBM-7103 were added thereto and stirred, and the resulting mixture was filtered through a PP syringe filter with a pore size of 0.2 μm to prepare a charge transport composition.

[0255] It should be noted that the arylsulfonic acid represented by the formula (b-1) was synthesized according to International Publication No. 2006 / 025342 (the same hereinafter).

[0256] In addition, a 10% by mass ethylene glycol solution of arylsulfonic acid B was also used in Comparative Example 1-2.

[0257] [Example 1-3]

[0258] 0.030 g of polythiophene derivative A and 0.048 g of 2-EHA were mixed with 0.941 g of EG and 1.930 g of DEG, and stirred at 80 °C for 1 hour using a hot stirrer. 0.965 g of 2-BOE and 4.826 g of TEGDME were added to the resulting mixture. 1.244 g of EG-ST and 0.015 g of the organosilane compound represented by the above formula (A1-8) (manufactured by Gelest, Inc., SIP6716.6) were added thereto and stirred, and the resulting mixture was filtered through a PP syringe filter with a pore size of 0.2 μm to prepare a charge transport composition.

[0259] [Comparative Example 1-1]

[0260] 0.030 g of polythiophene derivative A and 0.048 g of 2-EHA were mixed with 0.883 g of EG and 1.930 g of DEG, and stirred at 80 °C for 1 hour using a hot stirrer. 0.965 g of 2-BOE and 4.826 g of TEGDME were added to the resulting mixture and stirred. 1.317 g of EG-ST was added thereto and stirred, and the resulting mixture was filtered through a PP syringe filter with a pore size of 0.2 μm to prepare a charge transporting composition.

[0261] [Comparative Example 1-2]

[0262] 0.030 g of polythiophene derivative A and 0.048 g of 2-EHA were mixed with 0.788 g of EG and 1.930 g of DEG, and stirred at 80 °C for 1 hour using a hot stirrer. 0.965 g of 2-BOE and 4.826 g of TEGDME were added to the resulting mixture and stirred. 0.300 g of a 10 mass% ethylene glycol solution of arylsulfonic acid B, 1.098 g of EG-ST, and 0.015 g of phenyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., LS-2750) were added thereto and stirred, and the resulting mixture was filtered through a PP syringe filter with a pore size of 0.2 μm to prepare a charge transporting composition.

[0263] [Comparative Example 1-3]

[0264] 0.030 g of polythiophene derivative A and 0.048 g of 2-EHA were mixed with 0.941 g of EG and 1.930 g of DEG, and stirred at 80 °C for 1 hour using a hot stirrer. 0.965 g of 2-BOE and 4.826 g of TEGDME were added to the resulting mixture. 1.244 g of EG-ST and 0.015 g of phenyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., LS-2750) were added thereto and stirred, and the resulting mixture was filtered through a PP syringe filter with a pore size of 0.2 μm to prepare a charge transporting composition.

[0265] [3] Fabrication and Characterization of Devices

[0266] In the following Examples and Comparative Examples, the following product was used as the ITO substrate: a 25 mm × 25 mm × 0.7 t glass substrate with ITO patterned on the surface with a film thickness of 150 nm. Before use, impurities on the surface were removed using an O 2 plasma cleaning device (150 W, 30 seconds).

[0267] [3-1] Fabrication and Characterization of Single-Layer Devices (SLD)

[0268] [Example 2-1]

[0269] After coating the composition obtained in Example 1-1 on an ITO substrate using a spin coater, it was subjected to a preliminary firing at 120 °C for 1 minute under the atmosphere, and then, a main firing was carried out at 200 °C for 15 minutes, forming a 50-nm thin film on the ITO substrate.

[0270] On it, an aluminum thin film was formed using an evaporation apparatus (vacuum degree: 4.0×10 -5 Pa), obtaining a single-layer element. The evaporation was carried out under the condition of an evaporation rate of 0.2 nm / second. The film thickness of the aluminum thin film was set to 80 nm.

[0271] Furthermore, in order to prevent deterioration of characteristics caused by the influence of oxygen, water, etc. in the air, the SLD was sealed with a sealing substrate, and its characteristics were evaluated. Sealing was carried out according to the following procedure.

[0272] The SLD was placed between the sealing substrates in a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -85 °C or less, and the sealing substrates were bonded using an adhesive material (MORESCO MOISTURE CUT WB90US(P) manufactured by MORESCO Corporation). At this time, a water-trapping agent (HD-071010W-40 manufactured by Dainic Corporation) was placed together with the SLD inside the sealing substrates. For the bonded sealing substrates, UV light (wavelength: 365 nm, irradiation dose: 6,000 mJ / cm 2 ) was irradiated, and then annealing treatment was carried out at 80 °C for 1 hour to cure the adhesive material.

[0273] [Example 2-2]

[0274] An SLD was fabricated in the same manner as in Example 2-1, except that the composition obtained in Example 1-2 was used instead of the composition obtained in Example 1-1.

[0275] [Example 2-3]

[0276] An SLD was fabricated in the same manner as in Example 2-1, except that the composition obtained in Example 1-3 was used instead of the composition obtained in Example 1-1.

[0277] For each of the SLDs fabricated in the above examples, the current density at a driving voltage of 3 V was measured. The results are shown in Table 1.

[0278] [Table 1]

[0279]

[0280] [3-2] Fabrication and Characteristic Evaluation of Organic EL Element

[0281] [Example 3-1]

[0282] After coating the composition obtained in Example 1-1 on an ITO substrate using a spin coater, it was dried at 120 °C for 1 minute in the atmosphere, and then fired at 200 °C for 15 minutes to form a uniform 50-nm thin film (hole injection layer) on the ITO substrate.

[0283] On top of this, using an evaporation apparatus (vacuum degree: 2.0×10 -5 Pa), a 30-nm film of α-NPD (N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine) was formed. The evaporation rate at this time was set to 0.2 nm / second. Next, a 10-nm film of the electron blocking material HTEB-01 manufactured by Kanto Chemical Co., Inc. was formed. Next, co-evaporation was performed on the host material NS60 for the light-emitting layer and the dopant material Ir(PPy) 3 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. For the co-evaporation, the evaporation rate was controlled so that the concentration of Ir(PPy) 3 became 6%, and a 40-nm layer was stacked. Next, thin films of Alq 3 , lithium fluoride, and aluminum were sequentially stacked to obtain an organic EL element. At this time, regarding the evaporation rate, for Alq 3 and aluminum, it was set to 0.2 nm / second, and for lithium fluoride, it was set to 0.02 nm / second. The film thicknesses of the thin films of Alq 3 , lithium fluoride, and aluminum were set to 20 nm, 0.5 nm, and 80 nm, respectively.

[0284] Furthermore, in order to prevent deterioration of characteristics due to the influence of oxygen, water, etc. in the air, the organic EL element was sealed with a sealing substrate, and its characteristics were evaluated. Sealing was performed using the same method as above.

[0285] [Examples 3-2 to 3-3, Comparative Examples 3-1 to 3-3]

[0286] Except for using the compositions obtained in Examples 1-2 to 1-3 and Comparative Examples 1-1 to 1-3 instead of the composition obtained in Example 1-1, organic EL elements were fabricated using the same method as in Example 3-1.

[0287] For these elements, the light-emitting images at a driving voltage of 4.5 V were observed. The results are shown in Figure 1 . In addition, the voltage, current efficiency, external quantum efficiency of luminescence (EQE), and luminance lifetime (initial luminance: 5,000 cd / m 2 ) were measured at a luminance of 5,000 cd / m 2 . The results are shown in Table 2. It should be noted that the area of the light-emitting surface of each element was set to 2 mm × 2 mm.

[0288] [Table 2]

[0289]

[0290] As can be seen from Figure 1 the above, in the case of using the composition of the comparative example, unevenness on the surface of the obtained film was observed, and in many cases, a film with high flatness was not obtained. On the other hand, in the case of using the composition of the present invention, unevenness on the surface was not observed, and a charge transport film with excellent flatness could be manufactured with good reproducibility. Furthermore, as shown in Table 2, the organic EL element including the film obtained from the composition of the present invention (Example 3-1) had a lower driving voltage, higher current efficiency and EQE, and an extremely long luminance lifetime compared with the organic EL element including the film obtained from the composition of the comparative example (Comparative Example 3-1). In addition, compared with Comparative Example 3-2, Example 3-2 showed the same level of driving voltage, current efficiency and EQE, and had an extremely long luminance lifetime. In addition, compared with Comparative Example 3-3, Example 3-3 had a lower driving voltage, higher current efficiency and EQE.

Claims

1. An organic electroluminescent element having a charge-transporting thin film obtained from a charge-transporting composition, wherein the charge-transporting composition is characterized by containing: a charge-transporting substance having a polythiophene derivative or an amine adduct thereof containing a repeating unit represented by formula (1), at least one organosilane compound selected from a silane containing a fluoroalkyl group and a silane containing a fluoroaryl group, metal oxide nanoparticles, and a solvent, The metal oxide nanoparticles are SiO 2 , wherein the organosilane compound is at least one selected from the following formulas (A1-1) to (A1-15), (B1-1), and (B1-2), [Chemical formula 1] In the formula, R 1 is a hydrogen atom or a sulfonic acid group, R 2 is an alkoxy group having 1 to 40 carbon atoms or -O-[Z-O] p -R e , or R 1 and R 2 are -O-Y-O- formed by their combination, Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted by a sulfonic acid group, Z is an alkylene group having 1 to 40 carbon atoms which may be substituted by a halogen atom, p is an integer of 1 or more, and R e is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms. [Chemical formula 3] [Chemical formula 4] [Chemical formula 5] 2. The organic electroluminescent element according to claim 1, wherein the organosilane compound is the formula (A1-1) or (A1-8).

3. The organic electroluminescent element according to claim 1, wherein Said R 1 is a sulfonic acid group, said R 2 is an alkoxy group having 1 to 40 carbon atoms or -O-[Z-O] p -R e , or said R 1 and R 2 form -O-Y-O- by bonding.

4. The organic electroluminescent element according to claim 1, further comprising an electron-accepting dopant substance.

5. The organic electroluminescent element according to claim 4, wherein the electron-accepting dopant substance is an arylsulfonic acid compound.

6. The organic electroluminescent element according to claim 1, wherein the content of the silane containing a fluoroalkyl group and / or the silane containing a fluoroaryl group, expressed as the total of the silane containing a fluoroalkyl group and the silane containing a fluoroaryl group, is 0.1 to 50% by mass based on the mass of the solid content.

7. The organic electroluminescent element according to claim 1, wherein the content of the metal oxide nanoparticles is 40 to 95% by mass based on the mass of the solid content.

8. The organic electroluminescent element according to claim 1, wherein the solid content concentration of the charge-transporting composition is 0.1 to 15.0% by mass.

9. The organic electroluminescent element according to claim 1, wherein the charge-transporting thin film is a hole injection layer or a hole transport layer.

10. The organic electroluminescent element according to claim 1, wherein the charge-transporting thin film is obtained by coating the charge-transporting composition on a substrate and evaporating the solvent.

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