Fluorinated arylsulfonate polymer compound and use of same

Abstract

This fluorinated arylsulfonate polymer compound characterized by including a repeating unit represented by formula (1) and formula (2) provides, when used as a dopant substance for an organic EL element or the like, a charge transporting thin film having excellent hole injection properties and hole transport properties. [In the formulae, ArF1 and ArF2 each independently represent a fluorinated arylene group, X1 and X2 each independently represent O, S, NH, CONH, or NHCO, ArS represents an aryl group having at least one SO3R group on a ring (R represents a hydrogen atom or an alkali metal atom), R1 represents an alkyl group having 3-10 carbon atoms at least one of which being substituted with a fluorine atom, and R2 and R3 each independently represent a hydrogen atom or a methyl group.]

Description

Fluorinated aryl sulfonic acid polymer compounds and uses thereof

[0001] The present invention relates to a fluorinated aryl sulfonic acid polymer compound and its use.

[0002] In organic electroluminescence (hereinafter referred to as organic EL) devices, organic functional films made of organic compounds are used as light-emitting layers and charge injection layers. In particular, the hole injection layer is responsible for transferring charges between the anode and the hole transport layer, and is a layer that plays an important role in achieving low-voltage operation and high brightness of the organic EL device, and therefore, the hole transport layer formed thereon is required to have high hole injection properties.

[0003] Methods for forming hole injection layers are roughly divided into dry processes, such as vapor deposition, and wet processes, such as inkjet printing and spin coating. Compared to these processes, wet processes are more efficient at producing thin films with high flatness over large areas. Therefore, as organic EL displays are increasingly being manufactured with larger areas, there is a demand for hole injection layers that can be formed by wet processes. A technology related to hole injection materials that can be formed by wet processes has been reported (Patent Document 1).

[0004] Furthermore, in recent years, with the development of display technology, quantum dot electroluminescence (hereinafter referred to as quantum dot EL) devices, which use quantum dot materials as light-emitting layers, have emerged and are showing promise for a wide range of applications. These quantum dot EL devices can be manufactured at low cost using wet processes, and are attracting much attention in fields such as display technology and lighting due to their characteristics, such as controllability of emission wavelength, high color purity, high luminous efficiency, and flexibility.

[0005] As one such technique, the present applicant has already reported that when a specific fluorinated arylsulfonic acid polymer compound having a fluorinated arylene group and an aryl group containing at least one sulfo group or a salt thereof is used as a dopant substance together with a charge transport substance, a thin film having excellent charge transport properties can be realized, and an organic EL device including such a thin film exhibits good characteristics and has excellent life performance (Patent Document 2). However, there is room for further improvement in terms of hole injection properties and hole transport properties of this compound.

[0006] International Publication No. WO 2008 / 032616 International Publication No. WO 2023 / 008176

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluorinated arylsulfonic acid polymer compound that, when used as a dopant substance in an organic EL device or the like, gives a charge-transporting thin film that is excellent in hole injection property and hole transport property.

[0008] As a result of extensive research aimed at solving the above problems, the present inventors have found that a specific fluorinated arylsulfonic acid polymer into which a fluorinated alkyl group with low surface energy has been introduced has the property of being able to be efficiently doped into a charge transport substance near the surface layer of a charge transport thin film, thereby improving the hole injection property and hole transport property into the upper layer of a charge transport thin film containing the polymer, and thereby improving the performance of an organic EL device or the like comprising the thin film, and have completed the present invention.

[0009] That is, the present invention provides: 1. a fluorinated arylsulfonic acid polymer compound characterized by containing repeating units represented by the following formula (1) and the following formula (2): [In the formula, Ar F1 and Ar F2 each independently represents a fluorinated arylene group; 1 and X 2 each independently represents O, S, NH, CONH, or NHCO; Ar S represents an aryl group having at least one SO3R group on the ring (R represents a hydrogen atom or an alkali metal atom), and R 1represents an alkyl group having 3 to 10 carbon atoms substituted with at least one fluorine atom, and R 2 and R 3 each independently represents a hydrogen atom or a methyl group.] 2. F1 and Ar F2 3. The fluorinated arylsulfonic acid polymer compound of 1, wherein Ar is a perfluoroarylene group; F1 and Ar F2 3. The fluorinated arylsulfonic acid polymer compound of 2, wherein Ar is a tetrafluorophenylene group; S 4. The fluorinated aryl sulfonic acid polymer compound according to any one of 1 to 3, wherein Ar is an aryl group having two or more of the SO3R groups on the ring; S Fluorinated arylsulfonic acid polymer compound of 4, wherein X is a naphthyl group having two or more of the SO3R groups on the ring; 1 and X 2 is O; 7. a dopant substance comprising the fluorinated arylsulfonic acid polymer compound of any one of 1 to 6; 8. a charge transport varnish comprising a charge transport substance, the dopant substance of 7, and a solvent; 9. the charge transport varnish of 8, in which the charge transport substance is an arylamine derivative or a thiophene derivative; 10. a charge transport thin film obtained from the charge transport varnish of 8 or 9; 11. an electronic device comprising the charge transport thin film of 10; 12. the electronic device of 11, in which the charge transport thin film is a hole injection layer or a hole transport layer; 13. the electronic device of 11, in which the electronic device is an organic electroluminescence device or a quantum dot electroluminescence device.

[0010]

[0013] The fluorinated arylsulfonic acid polymer compound of the present invention has a fluorinated alkyl group with low surface energy. Therefore, when a charge-transporting thin film containing the polymer is formed by a wet process, the polymer tends to be localized in the surface layer, allowing efficient doping into the charge-transporting material near the surface. This improves the hole injection and hole transport properties of the charge-transporting thin film containing the polymer for the layer formed thereon. Organic EL devices comprising the charge-transporting thin film of the present invention exhibit excellent characteristics, particularly low driving voltage, high efficiency, and long life. The fluorinated arylsulfonic acid polymer compound of the present invention, which has such properties, can be suitably used as a dopant substance in the production of thin films for electronic devices, including organic EL devices and quantum dot EL devices.

[0011] The compound obtained in Synthesis Example 2 1 FIG. 1 shows a H-NMR spectrum.

[0012] The present invention is described in further detail below. [1] Fluorinated arylsulfonic acid polymer compound The fluorinated arylsulfonic acid polymer compound according to the present invention is characterized by containing repeating units represented by the following formula (1) and the following formula (2).

[0013]

[0014] In formulas (1) and (2), Ar F1 and Ar F2 each independently represents a fluorinated arylene group. These fluorinated arylene groups are not particularly limited as long as at least one hydrogen atom on the arylene group is substituted with a fluorine atom, but it is preferable that at least one of the remaining hydrogen atoms is substituted with an electron-withdrawing group other than a sulfo group. Examples of the electron-withdrawing group include halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; nitro groups; cyano groups; acyl groups; carboxy groups; carboxylic acid ester groups; and acyl groups such as formyl groups and acetyl groups. In particular, Ar F1 and Ar F2The fluorinated arylene group is preferably an arylene group substituted with two or more fluorine atoms, and more preferably a perfluoroarylene group.

[0015] Ar F1 and Ar F2 There is no particular limitation on the number of carbon atoms in the arylene group constituting Ar, but the number of carbon atoms is preferably 6 to 20, and more preferably 6 to 16. Specific examples thereof include 1,4-phenylene, 1,3-phenylene, 1,2-phenylene, 1,5-naphthylene, 1,7-naphthylene, 1,8-naphthylene, 2,6-naphthylene, 2,7-naphthylene, 4,4'-biphenylylene, and anthracenyl groups, with a phenylene group being preferred and a 1,4-phenylene group being more preferred. Therefore, Ar F1 and Ar F2 As the alkyl group, a tetrafluorophenylene group is preferred, and a 2,3,5,6-tetrafluoro-1,4-phenylene group is more preferred.

[0016] X 1 and X 2 each independently represents O, S, NH, CONH, or NHCO, with O or S being preferred, and O being more preferred.

[0017] In formula (1), Ar S represents an aryl group having at least one SO3R group on the ring, and R represents a hydrogen atom or an alkali metal atom such as Li, Na, or K, preferably a hydrogen atom. S There is no particular limitation on the number of carbon atoms in the aryl group constituting Ar, but it is preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and even more preferably 6 to 12 carbon atoms. Specific examples thereof include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl groups, with naphthyl groups being preferred, and 1-naphthyl groups being more preferred. S The number of SO3R groups contained in the compound may be one or more, preferably two to four, and more preferably two.

[0018] In formulas (1) and (2), R1 represents an alkyl group having 3 to 10 carbon atoms, preferably 3 to 8 carbon atoms, and more preferably 3 to 6 carbon atoms, substituted with at least one fluorine atom; R 2 and R 3 R each independently represents a hydrogen atom or a methyl group. 1 Specific examples of the alkyl group having 3 to 10 carbon atoms substituted with at least one, preferably two or more, more preferably three or more, even more preferably four or more, and still more preferably five or more fluorine atoms include 3-fluoropropyl, 2-fluoropropyl, 1-fluoropropyl, 3,3-difluoropropyl, 2,2-difluoropropyl, 1,1-difluoropropyl, 3,3,3-trifluoropropyl, 2,3,3,3-tetrafluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluoropropyl, 4-fluorobutyl, 3-fluorobutyl, 2-fluorobutyl, 1-fluorobutyl, 4,4-difluorobutyl, 3,3-difluorobutyl, 2,2-difluorobutyl, 1,1-difluorobutyl, 4,4,4- trifluorobutyl, 3,3,4,4,4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, perfluorobutyl, 5-fluoropentyl, 4-fluoropentyl, 3-fluoropentyl, 2-fluoropentyl, 1-fluoropentyl, 5,5-difluoropentyl, 4,4-difluoropentyl, 3,3-difluoropentyl, 2,2-difluoropentyl, 1,1-difluoropentyl, 5,5,5-trifluoropentyl, 4,4,5,5,5-pentafluoropentyl, 3,3,4,4,5,5,5-heptafluoropentyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl, and perfluorooctyl groups.

[0019] Suitable units of formula (1) include those represented by the following formula (1-1):

[0020] (wherein n1 represents an integer of 1 to 4, R 2 and Ar S has the same meaning as above.)

[0021] More preferred units of formula (1) include those represented by the following formula (1-2):

[0022] (wherein n1 represents an integer of 1 to 4, R 2 and Ar S has the same meaning as above.)

[0023] Even more preferred examples of the unit of formula (1) include those represented by the following formula (1-3):

[0024] (In the formula, Ar S has the same meaning as above.)

[0025] Also suitable Ar S As the compound represented by the following formula (Ar S -1) to (Ar S -6).

[0026] (In the formula, R has the same meaning as above, and n represents an integer of 2 to 4.)

[0027] (In the formula, R has the same meaning as above.)

[0028] (In the formula, R has the same meaning as above.)

[0029] (In the formula, R has the same meaning as above.)

[0030] Suitable units of formula (2) include those represented by the following formula (2-1):

[0031] (wherein n2 represents an integer of 1 to 4, R 1 and R 3 has the same meaning as above.)

[0032] More preferred units of formula (2) include those represented by the following formula (2-2):

[0033] (wherein n2 represents an integer of 1 to 4, R 1 and R 3 has the same meaning as above.)

[0034] Even more preferred examples of the unit of formula (2) include those represented by the following formula (2-3):

[0035] (In the formula, R 1 has the same meaning as above.)

[0036] In the fluorinated arylsulfonic acid polymer compound of the present invention, the content ratio of the unit of formula (1) to the unit of formula (2) is not particularly limited. However, in consideration of the effect of improving hole injection properties and the like when used as a dopant substance, the molar ratio of formula (1):formula (2) is preferably 10:1 to 1:10, more preferably 5:1 to 1:5, and even more preferably 4:1 to 1:4.

[0037] The fluorinated arylsulfonic acid polymer compound of the present invention may be a polymer containing only repeating units represented by the above formula (1) and formula (2), but may also contain a repeating unit represented by the following formula (3) (excluding the units of formula (1) and formula (2)).

[0038]

[0039] In formula (3), R′ represents a monovalent organic group, and R 4 represents a hydrogen atom or a methyl group. Examples of the monovalent organic group represented by R' include a monovalent hydrocarbon group, a heteroaryl group, and a -COOR" group (wherein R" represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms). There are no particular restrictions on the number of carbon atoms in the monovalent hydrocarbon group, but a carbon number of 1 to 20 is preferred, a carbon number of 6 to 20 is more preferred, and a carbon number of 6 to 10 is even more preferred. Specific examples thereof include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and aryl groups such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl.

[0040] Specific examples of heteroaryl groups include heteroaryl groups having 2 to 20 carbon atoms, such as 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, 2-imidazolyl, 4-imidazolyl, 2-pyridyl, 3-pyridyl, and 4-pyridyl groups.

[0041] Examples of the alkyl group having 1 to 10 carbon atoms represented by R″ include the same groups as those exemplified above, and among these, alkyl groups having 1 to 5 carbon atoms are preferred.

[0042] In addition, the monovalent hydrocarbon group, heteroaryl group, and alkyl group having 1 to 10 carbon atoms represented by R" may have some or all of their hydrogen atoms substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, a carboxy group, a sulfo group, and a hydroxyl group. Examples of the halogen atom include the same atoms as those exemplified above.

[0043] When the fluorinated arylsulfonic acid polymer compound of the present invention contains a repeating unit represented by formula (3), the content thereof is not particularly limited, but is preferably 0.1 to 50 mol %, more preferably 0.1 to 30 mol %, still more preferably 0.1 to 20 mol %, and even more preferably 0.1 to 10 mol % in the fluorinated arylsulfonic acid polymer compound.

[0044] The molecular weight of the fluorinated arylsulfonic acid polymer compound of the present invention is not particularly limited, but from the viewpoint of improving heat resistance and ensuring solubility in solvents, the weight average molecular weight Mw is preferably 1,000 to 50,000, more preferably 1,500 to 10,000, and even more preferably 2,000 to 10,000. The molecular weight distribution (Mw / Mn) is preferably 1 to 3, and more preferably 1 to 2. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) using polyethylene oxide as a standard sample.

[0045] The fluorinated arylsulfonic acid polymer compound of the present invention can be obtained by polymerizing a monomer represented by the following formula (1A), a monomer represented by the following formula (2A), and, if necessary, a monomer represented by the following formula (3A) in the presence of a solvent and a radical polymerization initiator by a known radical polymerization method. In this case, two or more types of monomers represented by formula (1A) may be used in combination, two or more types of monomers represented by formula (2A) may be used in combination, and two or more types of monomers represented by formula (3A) may be used in combination.

[0046] (In the formula, Ar F1 , Ar F2 , Ar S , X 1 , X 2 , R 1 , R 2 , R 3 , R 4 and R' have the same meaning as above.)

[0047] As the radical polymerization initiator, known compounds such as a radical thermal polymerization initiator, a radical photopolymerization initiator, etc. The radical thermal polymerization initiator is a compound that generates radicals when heated to a temperature equal to or higher than its decomposition temperature. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), diacyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy-2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), and azo compounds (azobisisobutyronitrile, 2,2′-di(2-hydroxyethyl)azobisisobutyronitrile, etc.). The radical thermal polymerization initiators may be used alone or in combination of two or more.

[0048] The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by light irradiation. Examples of such radical photopolymerization initiators include benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenyl ketone ... , 2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 4-dimethylaminobenzoic acid ethyl ester, 4-dimethylaminobenzoic acid isoamyl ester, 4,4'-di(tert-butylperoxycarbonyl)benzophenone, 3,4,4'-tri(tert-butylperoxy carbonyl)benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxy) styryl)-4,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(ethoxycarbonylmethyl)]-2,6-di(trichloromethyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4'-methoxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 2-mercaptobenzothiazole, 3,3'-carbonylbis(7-diethylaminocoumarin), 2-(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2 ,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 3-(2-methyl-2-dimethylaminopropionyl)carbazole, 3,6-bis(2-methyl-2-morpholinopropionyl)-9-n-dodecylcarbazole, 1-hydroxycyclohexyl phenyl ketone, Bis(5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetra(t-hexylperoxycarbonyl)benzophenone, 3,3'-di(methoxycarbonyl)-4,4'-di(t-butylperoxycarbonyl)benzophenone, 3,4'- Examples of the radical photopolymerization initiator include di(methoxycarbonyl)-4,3'-di(t-butylperoxycarbonyl)benzophenone, 4,4'-di(methoxycarbonyl)-3,3'-di(t-butylperoxycarbonyl)benzophenone, 2-(3-methyl-3H-benzothiazol-2-ylidene)-1-naphthalen-2-yl-ethanone, and 2-(3-methyl-1,3-benzothiazol-2(3H)-ylidene)-1-(2-benzoyl)ethanone. One type of radical photopolymerization initiator may be used alone, or two or more types may be used in combination.

[0049] The solvent used in the polymerization reaction is not particularly limited as long as it dissolves the produced polymer. Specific examples thereof include water, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, isopropyl alcohol, methoxymethyl pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,Examples of organic solvents include 4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide.

[0050] The polymerization temperature during radical polymerization can be selected from any temperature range of 30 to 150°C, but is preferably in the range of 50 to 100°C.

[0051] The monomer of formula (1A) can be produced by a known method disclosed in Patent Document 2, for example, by reacting an arylsulfonate having a hydroxyl group with a fluoroaryl compound in the presence of a base. The monomer of formula (2A) can be produced by reacting a fluorinated alkyl alcohol with a fluoroaryl compound in the presence of a base.

[0052] [2] Charge-Transporting Varnish The charge-transporting varnish of the present invention contains a dopant substance consisting of the above-mentioned fluorinated arylsulfonic acid polymer compound, a charge-transporting substance, and a solvent. In the present invention, charge-transporting property is synonymous with electrical conductivity and hole-transporting property. The charge-transporting varnish may itself have charge-transporting property, or the solid film obtained from it may have charge-transporting property.

[0053] The charge transporting substance is not particularly limited, and can be appropriately selected from charge transporting compounds, charge transporting oligomers, charge transporting polymers, etc. used in the field of organic electroluminescence, etc. Specific examples thereof include various charge transporting compounds such as arylamine derivatives such as oligoaniline derivatives, N,N'-diarylbenzidine derivatives, and N,N,N',N'-tetraarylbenzidine derivatives; thiophene derivatives such as oligothiophene derivatives, thienothiophene derivatives, and thienobenzothiophene derivatives; and pyrrole derivatives such as oligopyrrole; and charge transporting polymers such as charge transporting oligomers, polythiophene derivatives, polyaniline derivatives, and polypyrrole derivatives, among which polythiophene derivatives and arylamine derivatives are preferred.

[0054] Furthermore, from the viewpoint of producing a thin film with high flatness, it is preferable that the charge transport compound (low molecular weight compound) or charge transport oligomer, such as an arylamine compound represented by formula (H2) or (H3) described later, is monodisperse (i.e., has a molecular weight distribution of 1). In this case, the molecular weight of the charge transport substance is usually about 200 to 9,000 from the viewpoint of preparing a uniform varnish that gives a thin film with high flatness, but from the viewpoint of obtaining a thin film with better charge transport properties, it is preferably 300 or more, and more preferably 400 or more, and from the viewpoint of preparing a uniform varnish that gives a thin film with high flatness with good reproducibility, it is preferably 8,000 or less, more preferably 7,000 or less, even more preferably 6,000 or less, and even more preferably 5,000 or less.

[0055] Examples of the charge transporting substance include those described in JP 2002-151272 A, WO 2004 / 105446 A, WO 2005 / 043962 A, WO 2008 / 032617 A, WO 2008 / 032616 A, WO 2013 / 042623 A, WO 2014 / 141998 A, WO 2014 / 185208 A, WO 2015 / 050253 A, WO 2015 / 137391 A, WO 2015 / 137395 A, WO 2015 / 146912 A, WO 2015 / 146965, WO 2016 / 190326, WO 2016 / 136544, WO 2016 / 204079, WO 2017 / 122649, WO 2017 / 164158, WO 2019 / 177043, WO 2020 / 027258, WO 2020 / 027261, WO 2020 / 027264, WO 2020 / 196154, WO 2020 / 203594, WO 2020 / 241730 and the like.

[0056] In a preferred embodiment, the charge transporting substance is a polythiophene derivative containing a repeating unit represented by formula (H1) or an amine adduct thereof.

[0057]

[0058] In the formula, R 1 ' and R 2 ' each independently represents 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] h -R e , or a sulfo group, or R 1 ' and R 2 ' are bonded to each other to form -O-Y-O-, Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and which may be substituted with a sulfo 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.

[0059] The alkyl group having 1 to 40 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-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-eicosanyl, behenyl, triacontyl, tetracontyl, etc. In the present invention, an alkyl group having 1 to 18 carbon atoms is preferred, and an alkyl group having 1 to 8 carbon atoms is more preferred.

[0060] The fluoroalkyl group having 1 to 40 carbon atoms is not particularly limited as long as it is an alkyl group having 1 to 40 carbon atoms in which at least one hydrogen atom on a carbon atom is substituted with a fluorine atom, and specific examples thereof include 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, and 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 groups.

[0061] The alkoxy group having 1 to 40 carbon atoms may have a linear, branched, or cyclic alkyl group, and specific examples thereof include methoxy, ethoxy, n-propoxy, i-propoxy, c-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, n-hexoxy, 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-eicosanyloxy groups.

[0062] The fluoroalkoxy group having 1 to 40 carbon atoms is not particularly limited as long as it is an alkoxy group having 1 to 40 carbon atoms in which at least one hydrogen atom on a carbon atom is substituted with a fluorine atom, and specific examples thereof include fluoromethoxy, difluoromethoxy, perfluoromethoxy, 1-fluoroethoxy, 2-fluoroethoxy, 1,2-difluoroethoxy, 1,1-difluoroethoxy, 2,2-difluoroethoxy, 1,1,2-trifluoroethoxy, 1,2,2-trifluoroethoxy, 2,2,2-trifluoroethoxy, 1,1,2,2-tetrafluoroethoxy, 1,2,2,2-tetrafluoroethoxy, perfluoroethoxy, 1-fluoropropoxy, 2-fluoropropoxy, 3-fluoropropoxy, 1,1-difluoropropoxy, 1,2-difluoropropoxy, 1,3-difluoropropoxy, 2,2-difluoropropoxy, 2,3-difluoropropoxy, 3,3-difluoropropoxy, 1,1,2-trifluoropropoxy, 1,1,3-trifluoropropoxy, 1,2,3-trifluoropropoxy, 1,3,3-trifluoropropoxy, 2,2,3-trifluoropropoxy, 2,3,3-trifluoropropoxy, 3,3,3-trifluoropropoxy, 1,1,2,2-tetrafluoropropoxy, 1,1,2,3-tetrafluoropropoxy, 1,2,2,3-tetrafluoropropoxy oxy, 1,3,3,3-tetrafluoropropoxy, 2,2,3,3-tetrafluoropropoxy, 2,3,3,3-tetrafluoropropoxy, 1,1,2,2,3-pentafluoropropoxy, 1,2,2,3,3-pentafluoropropoxy, 1,1,3,3,3-pentafluoropropoxy, 1,2,3,3,3-pentafluoropropoxy, 2,2,3,3,3-pentafluoropropoxy, and perfluoropropoxy groups.

[0063] The alkylene group having 1 to 40 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene, octadecylene, nonadecylene, and eicosanylene groups.

[0064] Specific examples of aryl groups having 6 to 20 carbon atoms include phenyl, tolyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl groups, with phenyl, tolyl, and naphthyl being preferred. Specific examples of aryloxy groups having 6 to 20 carbon atoms include phenoxy, anthracenoxy, naphthoxy, phenanthrenoxy, and fluorenoxy groups. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0065] In the above formula (H1), R 1 ' and R 2 ' each independently represents a hydrogen atom, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, or -O[C(R a R b )-C(R c R d ) -O] h -R e , -OR f , or a sulfo group, or R 1 ' and R 2 -O-Y-O- formed by bonding R' is preferred. a ~R d each independently represents 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, and specific examples of these groups include the same groups as those listed above. a ~R dare 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. e is 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 is preferably a hydrogen atom, a methyl group, a propyl group, or a butyl group. h is preferably an integer of 1 to 5, and more preferably 1, 2, or 3.

[0066] R f represents 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, but 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, and more preferably —CHCF.

[0067] The above R 1 is preferably a hydrogen atom or a sulfo group, more preferably a sulfo group, and R 2 ' is preferably an alkoxy group having 1 to 40 carbon atoms or -O-[ZO] h -R e , more preferably —O[C(R a R b )-C(R c R d ) -O] h -R e or -OR f , and even more preferably —O[C(R a R b )-C(R c R d ) -O] h -R e , —O—CH2CH2—O—CH2CH2—O—CH3, —O—CH2CH2—O—CH2CH2—OH or —O—CH2CH2—OH, or R 1 ' and R 2 ' are bonded to each other to form -O-Y-O-.

[0068] For example, the polythiophene derivative according to a preferred embodiment of the present invention may be 1 ' is a sulfo group, and R 2 ' contains a repeating unit other than a sulfo group, or R 1' and R 2 Preferably, the polythiophene derivative contains a repeating unit in which R 1 ' is a sulfo group, and R 2 ' is an alkoxy group having 1 to 40 carbon atoms or -O-[ZO] h -R e or R 1 ' and R 2 More preferably, the polythiophene derivative contains a repeating unit of -O-Y-O- formed by bonding of R 1 ' is a sulfo group, and R 2 ' is -O[C(R a R b )-C(R c R d ) -O] h -R e or -OR f More preferably, the polythiophene derivative comprises a repeating unit represented by R 1 ' is a sulfo group, and R 2 ' is -O[C(R a R b )-C(R c R d ) -O] h -R e or R 1 ' and R 2 More preferably, the polythiophene derivative contains a repeating unit of -O-Y-O- formed by bonding of R 1 ' is a sulfo group, and R 2 R′ comprises a repeat unit in which R is —O—CH2CH2—O—CH2CH2—O—CH3, —O—CH2CH2—O—CH2CH2—OH, or —O—CH2CH2—OH; 1 ' and R 2 ' are bonded to each other to form repeating units which are groups represented by the following formulae (Y1) and (Y2).

[0069]

[0070] Preferred specific examples of the polythiophene derivative include polythiophenes containing at least one repeating unit represented by the following formulae (H1-1) to (H1-5).

[0071]

[0072] A suitable structure of the polythiophene derivative is, for example, a polythiophene derivative having a structure represented by the following formula (1a): In the following formula, the units may be bonded randomly or as a block polymer.

[0073]

[0074] In the formula, a to d represent the molar ratio of each unit, and satisfy the following conditions: 0≦a≦1, 0≦b≦1, 0<a+b≦1, 0≦c<1, 0≦d<1, a+b+c+d=1.

[0075] Furthermore, the polythiophene derivatives may be homopolymers or copolymers (including statistical, random, gradient, and block copolymers). As polymers containing monomers A and B, block copolymers include, for example, AB diblock copolymers, A-B-A triblock copolymers, and (AB) k - including multi-block copolymers. Polythiophenes may also contain repeat units derived from other types of monomers, such as thienothiophenes, selenophenes, pyrroles, furans, tellurophenes, anilines, arylamines, and arylenes (such as phenylene, phenylenevinylene, and fluorene).

[0076] The content of the repeating unit represented by formula (H1) in the polythiophene derivative is preferably more than 50 mol %, more preferably 80 mol % or more, even more preferably 90 mol % or more, still more preferably 95 mol % or more, and most preferably 100 mol % of all repeating units contained in the polythiophene derivative.

[0077] The polythiophene derivative may contain repeating units derived from impurities, depending on the purity of the starting monomers used in the polymerization. The term "homopolymer" refers to a polymer containing repeating units derived from one type of monomer, but may also contain repeating units derived from impurities. The polythiophene derivative is preferably a polymer in which essentially all repeating units are repeating units represented by formula (H1), and more preferably a polymer containing at least one of repeating units represented by formulas (H1-1) to (H1-5).

[0078] When the polythiophene derivative contains a repeating unit having a sulfo group, from the viewpoint of further improving solubility and dispersibility in organic solvents, the polythiophene derivative is preferably an amine adduct in which an amine compound is added to at least a portion of the sulfo groups contained therein.

[0079] Examples of amine compounds that can be used to form the amine adduct include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, s-butylamine, t-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, and n- monoalkylamine compounds such as octadecylamine, n-nonadecylamine, and n-eicosanylamine; primary amine compounds such as monoarylamine compounds such as aniline, tolylamine, 1-naphthylamine, 2-naphthylamine, 1-anthrylamine, 2-anthrylamine, 9-anthrylamine, 1-phenanthrylamine, 2-phenanthrylamine, 3-phenanthrylamine, 4-phenanthrylamine, and 9-phenanthrylamine; primary amine compounds such as N-ethylmethylamine, N-methyl-n-propylamine, N-methylisopropylamine, N-methyl- n-butylamine, N-methyl-s-butylamine, N-methyl-t-butylamine, N-methylisobutylamine, diethylamine, N-ethyl-n-propylamine, N-ethylisopropylamine, N-ethyl-n-butylamine, N-ethyl-s-butylamine, N-ethyl-t-butylamine, dipropylamine, N-n-propylisopropylamine, N-n-propyl-n-butylamine, N-n-propyl-s-butylamine, diisopropylamine, N-n-butylisopropylamine, N-t-butylisopropylamine, di(n- dialkylamine compounds such as di(butyl)amine, di(s-butyl)amine, diisobutylamine, aziridine (ethyleneimine), 2-methylaziridine (propyleneimine), 2,2-dimethylaziridine, azetidine (trimethyleneimine), 2-methylazetidine, pyrrolidine, 2-methylpyrrolidine, 3-methylpyrrolidine, 2,5-dimethylpyrrolidine, piperidine, 2,6-dimethylpiperidine, 3,5-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, hexamethyleneimine, heptamethyleneimine, and 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, and 13H-dibenzo[a,i]carbazole; N-methylaniline, N-ethylaniline, N-n-propylaniline, N-iso ... secondary amine compounds such as alkylarylamine compounds such as N,N-isopropylaniline, N-n-butylaniline, N-s-butylaniline, N-isobutylaniline, N-methyl-1-naphthylamine, N-ethyl-1-naphthylamine, N-n-propyl-1-naphthylamine, indoline, isoindoline, 1,2,3,4-tetrahydroquinoline, and 1,2,3,4-tetrahydroisoquinoline; Trialkylamine compounds such as N-dimethylisopropylamine, N,N-dimethyl-n-butylamine, N,N-dimethyl-s-butylamine, N,N-dimethyl-t-butylamine, N,N-dimethylisobutylamine, N,N-diethylmethylamine, N-methyldi(n-propyl)amine, N-methyldiisopropylamine, N-methyldi(n-butyl)amine, N-methyldiisobutylamine, triethylamine, N,N-diethyl-n-butylamine, N,N-diisopropylethylamine, N,N-di(n-butyl)ethylamine, tri(n-propyl)amine, tri(i-propyl)amine, tri(n-butyl)amine, tri(i-butyl)amine, 1-methylacetidine, 1-methylpyrrolidine, and 1-methylpiperidine; triarylamine compounds such as triphenylamine; alkyldiarylamine compounds such as N-methyldiphenylamine, N-ethyldiphenylamine, 9-methylcarbazole, and 9-ethylcarbazole;Examples of suitable tertiary amine compounds include dialkylarylamine compounds such as N,N-diethylaniline, N,N-di(n-propyl)aniline, N,N-di(i-propyl)aniline, and N,N-di(n-butyl)aniline. However, taking into consideration the balance between the solubility of the amine adduct and the charge transport properties of the resulting organic functional film, tertiary amine compounds are preferred, trialkylamine compounds are more preferred, and triethylamine is even more preferred. The amine adduct can be obtained by adding the polythiophene derivative to the amine itself or a solution thereof and stirring thoroughly.

[0080] The polythiophene derivative or its amine adduct may be treated with a reducing agent. In polythiophene derivatives or their amine adducts, some of the repeating units constituting them may have an oxidized chemical structure called a "quinoid structure." The term "quinoid structure" is used in contrast to the term "benzenoid structure." The latter refers to a structure containing an aromatic ring, whereas the former refers to a structure in which a double bond within the aromatic ring moves outside the ring (resulting in the disappearance of the aromatic ring), forming two exocyclic double bonds conjugated with other double bonds remaining within the ring. Those skilled in the art can easily understand the relationship between these two structures from the relationship between the structures of benzoquinone and hydroquinone. Quinoid structures for repeating units of various conjugated polymers are well known to those skilled in the art. As an example, a quinoid structure corresponding to a repeating unit of a polythiophene derivative containing a repeating unit represented by the above formula (H1) is shown in the following formula (H1').

[0081] (In the formula, R 1’ and R 2’ is as defined in the above formula (H1).

[0082] This quinoid structure is generated by a process in which a polythiophene derivative containing a repeating unit represented by formula (H1) undergoes an oxidation reaction with a dopant, a so-called doping reaction, and forms part of structures known as "polaron structures" and "bipolaron structures" that impart charge transport properties to the polythiophene derivative. These structures are known. The introduction of a "polaron structure" and / or a "bipolaron structure" is essential in the fabrication of organic EL devices. In fact, this is achieved by intentionally inducing the doping reaction when a thin film formed from a charge transport varnish is baked during the fabrication of organic EL devices. The presence of a quinoid structure in the polythiophene derivative prior to the doping reaction is thought to be due to an unintended oxidation reaction equivalent to the doping reaction occurring in the polythiophene derivative during its manufacturing process (particularly the sulfonation step therein).

[0083] There is a correlation between the amount of quinoid structures contained in the polythiophene derivative and the solubility and dispersibility of the polythiophene derivative in organic solvents; as the amount of quinoid structures increases, the solubility and dispersibility tend to decrease. Therefore, the introduction of quinoid structures after a thin film is formed from a charge-transporting varnish does not cause any problems. However, if an excessive amount of quinoid structures is introduced into the polythiophene derivative due to the unintended oxidation reaction, the production of the charge-transporting varnish may be hindered. Polythiophene derivatives are known to have varying solubility and dispersibility in organic solvents. One of the causes is thought to be that the amount of quinoid structures introduced into the polythiophene due to the unintended oxidation reaction varies depending on the production conditions of each polythiophene derivative. Therefore, when the polythiophene derivative is subjected to a reduction treatment using a reducing agent, even if an excessive amount of quinoid structures is introduced into the polythiophene derivative, the quinoid structures are reduced by reduction, improving the solubility and dispersibility of the polythiophene derivative in organic solvents. This enables the stable production of a good charge-transporting varnish that provides a thin film with excellent uniformity.

[0084] The conditions for the reduction treatment are not particularly limited as long as they can reduce the quinoid structure and appropriately convert it into a non-oxidized structure, i.e., the benzenoid structure (for example, in the case of a polythiophene derivative containing a repeating unit represented by formula (H1) above, the quinoid structure represented by formula (H1′) is converted into the structure represented by formula (H1) above). For example, this treatment can be carried out by simply contacting the polythiophene derivative or the amine adduct with a reducing agent in the presence or absence of a suitable solvent. The reducing agent is also not particularly limited as long as it can appropriately reduce the polythiophene derivative or the amine adduct. Suitable examples of the reducing agent include aqueous ammonia and hydrazine, which are readily available commercially. The amount of the reducing agent cannot be generally specified because it varies depending on the amount of reducing agent used. However, it is usually 0.1 parts by mass or more per 100 parts by mass of the polythiophene derivative or the amine adduct to be treated in order to appropriately reduce the polythiophene derivative or the amine adduct, and 10 parts by mass or less in order to prevent excess reducing agent from remaining.

[0085] In one example of a specific reduction method, the polythiophene derivative or the amine adduct is stirred overnight in 28% aqueous ammonia at room temperature. Reduction under such relatively mild conditions sufficiently improves the solubility and dispersibility of the polythiophene derivative or the amine adduct in organic solvents.

[0086] When an amine adduct of a polythiophene derivative is used in the charge-transporting varnish of the present invention, the reduction treatment may be carried out either before or after the formation of the amine adduct.

[0087] Note that, as a result of this reduction treatment changing the solubility or dispersibility of the polythiophene derivative or its amine adduct in the solvent, the polythiophene derivative or its amine adduct, which was not dissolved in the reaction system at the start of the treatment, may become dissolved by the completion of the treatment. In such cases, the polythiophene derivative or its amine adduct can be recovered by a method such as adding an organic solvent incompatible with the polythiophene derivative or its amine adduct (acetone, isopropyl alcohol, etc., in the case of sulfonated polythiophene) to the reaction system to cause a precipitate of the polythiophene derivative or its amine adduct, and then filtering the precipitate.

[0088] The weight-average molecular weight of the polythiophene derivative or its amine adduct containing a repeating unit represented by formula (H1) is preferably about 1,000 to 1,000,000, more preferably about 5,000 to 100,000, and even more preferably about 10,000 to about 50,000. By setting the weight-average molecular weight at or above the lower limit, good electrical conductivity can be obtained with good reproducibility, while by setting it at or below the upper limit, solubility in solvents is improved. Note that this weight-average molecular weight is a polystyrene-equivalent value measured by GPC.

[0089] The polythiophene derivative or its amine adduct contained in the charge-transporting varnish used in the present invention may be a polythiophene derivative or its amine adduct containing a repeating unit represented by formula (H1), or two or more of them may be used. The polythiophene derivative containing a repeating unit represented by formula (H1) may be a commercially available product, or may be one polymerized by a known method using a thiophene derivative or the like as a starting material. In either case, it is preferable to use one purified by a method such as reprecipitation or ion exchange. The use of a purified product can further improve the properties of an organic EL device equipped with a thin film obtained from the charge-transporting varnish of the present invention.

[0090] Sulfonation of conjugated polymers and sulfonated conjugated polymers (including sulfonated polythiophenes) are described in U.S. Patent No. 8,017,241 to Seshadri et al., and sulfonated polythiophenes are described in WO 2008 / 073149 and WO 2016 / 171935.

[0091] At least a portion of the polythiophene derivative containing the repeating unit represented by the formula (H1) or its amine adduct is dissolved in a solvent described below.

[0092] In the present invention, when a polythiophene derivative having a repeating unit represented by formula (H1) or an amine adduct thereof is used, the polythiophene derivative or the amine adduct thereof may be used in combination with a charge transporting substance composed of another charge transporting compound, but it is preferable that only a polythiophene derivative having a repeating unit represented by formula (H1) or an amine adduct thereof is used.

[0093] When a polythiophene derivative containing a repeating unit represented by formula (H1) or an amine adduct thereof is used, the content of the charge-transporting substance in the charge-transporting varnish is usually determined appropriately in the range of 0.05 to 40% by mass, preferably 0.1 to 35% by mass, based on the solid content, taking into consideration the desired film thickness, the viscosity of the varnish, and the like.

[0094] Other preferred embodiments of the charge transporting substance include those represented by the following formulae (H2) and (H3).

[0095]

[0096] The aniline derivative represented by formula (H2) may be an oxidized aniline derivative (quinone diimine derivative) having a quinone diimine structure represented by the following formula in its molecule: Methods for oxidizing an aniline derivative to form a quinone diimine derivative include the methods described in WO 2008 / 010474 and WO 2014 / 119782.

[0097]

[0098] In formula (H2), R1a ~R 6a are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, Z 1 an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z 2 an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, optionally substituted with -NHY; 1 , -NY 2 Y 3 , -OY 4 , or -SY 5 represents a group, and Y 1 ~Y 5 are each independently Z 1 an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z 2 represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted by 1 is a halogen atom, a nitro group, a cyano group, an amino group, or Z 3 represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, which may be substituted by 2 is a halogen atom, a nitro group, a cyano group, an amino group, or Z 3 represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with 3 represents a halogen atom, a nitro group, a cyano group, or an amino group; k and l each independently represent an integer of 1 to 5.

[0099] In formula (H3), R 7a ~R 10a are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a thiol group, a phosphate group, a sulfo group, a carboxyl group, Z 1 an alkoxy group having 1 to 20 carbon atoms, a thioalkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z 2R represents an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 1 to 20 carbon atoms, each of which may be substituted with 11a ~R 14a each independently represents a hydrogen atom, a phenyl group, a naphthyl group, a pyridyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a furanyl group, a pyrrolyl group, a pyrazolyl group, an imidazolyl group, a thienyl group (these groups may be substituted with a halogen atom, a nitro group, a cyano group, a hydroxyl group, a thiol group, a phosphate group, a sulfo group, a carboxy group, an alkoxy group having 1 to 20 carbon atoms, a thioalkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 1 to 20 carbon atoms), or a group represented by formula (H3a) (with the proviso that R 11a ~R 14a At least one of the groups is a hydrogen atom, and m represents an integer of 2 to 5. 1 and Z 2 has the same meaning as above.

[0100]

[0101] In formula (H3a), R 15a ~R 18a are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a thiol group, a phosphate group, a sulfo group, a carboxyl group, Z 1 an alkoxy group having 1 to 20 carbon atoms, a thioalkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z 2 R represents an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 1 to 20 carbon atoms, each of which may be substituted with 19a and R 20aeach independently represents a phenyl group, a naphthyl group, an anthryl group, a pyridyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a furanyl group, a pyrrolyl group, a pyrazolyl group, an imidazolyl group, or a thienyl group (these groups may be bonded to each other to form a ring, or may be substituted with a halogen atom, a nitro group, a cyano group, a hydroxyl group, a thiol group, a phosphate group, a sulfo group, a carboxy group, an alkoxy group having 1 to 20 carbon atoms, a thioalkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 1 to 20 carbon atoms). Z 1 and Z 2 has the same meaning as above.

[0102] In the above formulas, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and examples thereof include linear or branched alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; and cyclic alkyl groups having 3 to 20 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, and bicyclodecyl groups.

[0103] Specific examples of alkenyl groups having 2 to 20 carbon atoms include ethenyl, n-1-propenyl, n-2-propenyl, 1-methylethenyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, n-1-decenyl, and n-1-eicosenyl groups.

[0104] Specific examples of alkynyl groups having 2 to 20 carbon atoms include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, n-3-butynyl, 1-methyl-2-propynyl, n-1-pentynyl, n-2-pentynyl, n-3-pentynyl, n-4-pentynyl, 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n-butynyl, 1,1-dimethyl-n-propynyl, n-1-hexynyl, n-1-decynyl, n-1-pentadecinyl, and n-1-eicosynyl groups.

[0105] Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl groups.

[0106] Specific examples of the aralkyl group having 7 to 20 carbon atoms include benzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl, and naphthylpropyl groups.

[0107] Specific examples of heteroaryl groups having 2 to 20 carbon atoms include 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, 2-imidazolyl, 4-imidazolyl, 2-pyridyl, 3-pyridyl, and 4-pyridyl groups.

[0108] Examples of haloalkyl groups having 1 to 20 carbon atoms include those in which at least one hydrogen atom of the alkyl groups having 1 to 20 carbon atoms has been substituted with a halogen atom. Among these, fluoroalkyl groups are preferred, and perfluoroalkyl groups are more preferred. Specific examples thereof include fluoromethyl, difluoromethyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, heptafluoropropyl, 2,2,3,3,3-pentafluoropropyl, 2,2,3,3-tetrafluoropropyl, 2,2,2-trifluoro-1-(trifluoromethyl)ethyl, nonafluorobutyl, 4,4,4-trifluorobutyl, undecafluoropentyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, 2,2,3,3,4,4,5,5-octafluoropentyl, tridecafluorohexyl, 2,2,3,3,4,4,5,5,6,6,6-undecafluorohexyl, 2,2,3,3,4,4,5,5,6,6-decafluorohexyl, and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups.

[0109] Specific examples of the alkoxy group having 1 to 20 carbon atoms include methoxy, ethoxy, n-propoxy, i-propoxy, c-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, n-hexoxy, 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-eicosanyloxy groups.

[0110] Specific examples of the thioalkoxy (alkylthio) group having 1 to 20 carbon atoms include methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, s-butylthio, t-butylthio, n-pentylthio, n-hexylthio, n-heptylthio, n-octylthio, n-nonylthio, n-decylthio, n-undecylthio, n-dodecylthio, n-tridecylthio, n-tetradecylthio, n-pentadecylthio, n-hexadecylthio, n-heptadecylthio, n-octadecylthio, n-nonadecylthio, and n-eicosanylthio groups.

[0111] Specific examples of the acyl group having 1 to 20 carbon atoms include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, and benzoyl groups.

[0112] In formula (H2), R 1a ~R 6a represents a hydrogen atom, a halogen atom, or Z 1 an alkyl group having 1 to 20 carbon atoms which may be substituted with 2 an aryl group having 6 to 20 carbon atoms which may be substituted with -NHY; 1 , -NY 2 Y 3 , -OY 4 , or -SY 5 is preferred, in which case Y 1 ~Y 5 Is Z 1 an alkyl group having 1 to 10 carbon atoms which may be substituted with Z 2 An aryl group having 6 to 10 carbon atoms which may be substituted by is preferred, and Z 1 an alkyl group having 1 to 6 carbon atoms which may be substituted with Z 2 A phenyl group optionally substituted with R is more preferred, and an alkyl group having 1 to 6 carbon atoms or a phenyl group is even more preferred. 1a ~R 6a represents a hydrogen atom, a fluorine atom, a methyl group, a phenyl group, or a diphenylamino group (Y 2 and Y 3 is a phenyl group 2 Y 3 ) is more preferred, and R1a ~R 4a is a hydrogen atom, and R 5a and R 6a At the same time, a hydrogen atom or a diphenylamino group is even more preferred.

[0113] In particular, R 1a ~R 6a and Y 1 ~Y 5 In this case, Z 1 is a halogen atom or Z 3 An aryl group having 6 to 10 carbon atoms which may be substituted with is preferred, a fluorine atom or a phenyl group is more preferred, and it is even more preferred that it is absent (i.e., an unsubstituted group). 2 is a halogen atom or Z 3 An alkyl group having 1 to 10 carbon atoms which may be substituted with is preferred, a fluorine atom or an alkyl group having 1 to 6 carbon atoms is more preferred, and it is even more preferred that it is not present (i.e., it is an unsubstituted group). 3 is preferably a halogen atom, more preferably a fluorine atom, and even more preferably is absent (i.e., is an unsubstituted group). From the viewpoint of increasing the solubility of the aniline derivative represented by formula (H2), k and l preferably satisfy k+l≦8, more preferably k+l≦5.

[0114] In formula (H3), R 7a ~R 10a is preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and more preferably a hydrogen atom. In addition, in consideration of increasing the solubility of the aniline derivative represented by formula (H3) in a solvent and improving the uniformity of the resulting thin film, R 11a and R 13a are preferably both hydrogen atoms. 11a and R 13a are both hydrogen atoms, and R 12a and R 14aare each independently a phenyl group (this phenyl group may be substituted with a halogen atom, a nitro group, a cyano group, a hydroxyl group, a thiol group, a phosphate group, a sulfo group, a carboxy group, an alkoxy group having 1 to 20 carbon atoms, a thioalkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 1 to 20 carbon atoms), or a group represented by the above formula (H3a), and R 11a and R 13a are both hydrogen atoms, and R 12a and R 14a are each independently a phenyl group, or R 19a′ and R 20a′ and R are each a phenyl group, and more preferably a group represented by the following formula (H3a'): 11a and R 13a are both hydrogen atoms, and R 12a and R 14a Furthermore, m is preferably 2 to 4 in consideration of the availability of the compound, ease of production, cost, etc., and more preferably 2 or 3 in consideration of increasing solubility in a solvent, and is optimal in consideration of the balance between the availability of the compound, ease of production, production cost, solubility in a solvent, transparency of the resulting thin film, etc.

[0115]

[0116] The aniline derivatives represented by formulas (H2) and (H3) may be commercially available products or products produced by known methods such as those described in the above publications. In either case, however, it is preferable to use products purified by recrystallization, vapor deposition, or the like before preparing the charge-transporting varnish. By using a purified product, the properties of electronic devices equipped with thin films obtained from the varnish can be further improved. When purifying by recrystallization, for example, 1,4-dioxane, tetrahydrofuran, or the like can be used as a solvent.

[0117] In the present invention, as the charge transporting substance represented by formula (H2) or (H3), one compound selected from the compounds represented by formula (H2) or (H3) (i.e., having a polydispersity of 1 in molecular weight distribution) may be used alone, or two or more compounds may be used in combination.

[0118] Specific examples of the charge transporting materials represented by formulas (H2) and (H3) that can be suitably used in the present invention include, but are not limited to, the following.

[0119]

[0120] Furthermore, in the present invention, aniline derivatives represented by the following formula can also be suitably used as charge transporting materials.

[0121] (In the formula, DPA represents a diphenylamino group.)

[0122] In the charge-transporting varnish of the present invention, the amount of the fluorinated arylsulfonic acid polymer compound used as the dopant substance is preferably about 0.1 to 10.0, more preferably about 0.2 to 5.0, relative to the charge-transporting substance such as a polythiophene derivative or an arylamine derivative, in terms of mass ratio, per 1 part. The charge-transporting varnish of the present invention may contain known organic or inorganic dopant substances in addition to the fluorinated arylsulfonic acid polymer compound, but it is preferable that the charge-transporting varnish does not contain these other dopant substances.

[0123] The solvent used in preparing the charge-transporting varnish of the present invention may be a highly polar solvent capable of dissolving the charge-transporting material, dopant material, etc., used. If necessary, a low-polarity solvent may be used because it has better process compatibility than a high-polarity solvent. In the present invention, a low-polarity solvent is defined as one having a dielectric constant of less than 7 at a frequency of 100 kHz, and a high-polarity solvent is defined as one having a dielectric constant of 7 or more at a frequency of 100 kHz.

[0124] Examples of low-polarity solvents include: chlorine-based solvents such as chloroform and chlorobenzene; aromatic hydrocarbon-based solvents such as toluene, xylene, tetralin, cyclohexylbenzene, and decylbenzene; aliphatic alcohol-based solvents such as 1-octanol, 1-nonanol, and 1-decanol; ether-based solvents such as tetrahydrofuran, dioxane, anisole, 4-methoxytoluene, 3-phenoxytoluene, dibenzyl ether, diethylene glycol dimethyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, and triethylene glycol butyl methyl ether; and ester-based solvents such as methyl benzoate, ethyl benzoate, butyl benzoate, isoamyl benzoate, bis(2-ethylhexyl) phthalate, dibutyl maleate, dibutyl oxalate, hexyl acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate.

[0125] Examples of highly polar solvents include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutyramide, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone; ketone solvents such as ethyl methyl ketone, isophorone, and cyclohexanone; cyano solvents such as acetonitrile and 3-methoxypropionitrile; polyhydric alcohol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, and 2,3-butanediol; monohydric alcohol solvents other than aliphatic alcohols such as diethylene glycol monomethyl ether, diethylene glycol monophenyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, benzyl alcohol, 2-phenoxyethanol, 2-benzyloxyethanol, 3-phenoxybenzyl alcohol, and tetrahydrofurfuryl alcohol; and sulfoxide solvents such as dimethyl sulfoxide.

[0126] Furthermore, the charge-transporting varnish of the present invention may contain one or more types of metal oxide nanoparticles. Nanoparticles refer to fine particles whose primary particle average particle diameter is on the order of nanometers (typically 500 nm or less). Metal oxide nanoparticles refer to metal oxides formed into nanoparticles. The primary particle diameter of the metal oxide nanoparticles is not particularly limited as long as it is nano-sized, but is preferably 2 to 150 nm, more preferably 3 to 100 nm, and even more preferably 5 to 50 nm. The particle diameter is measured using a nitrogen adsorption isotherm according to the BET method.

[0127] The metals constituting the metal oxide nanoparticles include metals in the usual sense as well as metalloids. While metals in the usual sense are not particularly limited, it is preferable to use one or more selected from the group consisting of tin (Sn), titanium (Ti), aluminum (Al), zirconium (Zr), zinc (Zn), niobium (Nb), tantalum (Ta), and tungsten (W). Meanwhile, metalloids refer to elements whose chemical and / or physical properties are intermediate between those of metals and nonmetals. While a universal definition of metalloids has not been established, in the present invention, a total of six elements, namely boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te), are considered metalloids. These metalloids may be used alone or in combination with two or more of them, or may be used in combination with metals in the usual sense.

[0128] In particular, the metal oxide nanoparticles preferably contain an oxide 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). When two or more metals are used in combination, the metal oxide may be a mixture of oxides of individual metals or a composite oxide containing multiple metals.

[0129] Specific examples of metal oxides include BO, BO, SiO, SiO, GeO, GeO, AsO, AsO, AsO, SbO, SbO, TeO, SnO, SnO, ZrO, AlO, and ZnO. However, BO, BO, SiO, SiO, GeO, GeO, AsO, AsO, AsO, SnO, SnO, SbO, TeO, and mixtures thereof are preferred, and SiO is more preferred.

[0130] The amount of metal oxide nanoparticles is not particularly limited, but from the viewpoint of improving the transparency of the obtained thin film, enhancing the uniformity of the film, etc., the lower limit of the solid content is usually 50 mass %, preferably 60 mass %, more preferably 65 mass %, and the upper limit is usually 95 mass %, preferably 90 mass %.

[0131] In particular, in the present invention, it is preferable to use a silica sol in which SiO nanoparticles are dispersed in a dispersion medium as the metal oxide nanoparticles. The silica sol is not particularly limited, and any known silica sol can be appropriately selected and used. Commercially available silica sols are usually in the form of a dispersion liquid. Examples of commercially available silica sols include those in which SiO nanoparticles are dispersed 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, and propylene glycol monomethyl ether acetate.

[0132] Specific examples of commercially available silica sols include, but are not limited to, water-dispersed silica sols such as Snowtex (registered trademark) ST-O, ST-OS, ST-O-40, and ST-OL manufactured by Nissan Chemical Industries, Ltd., and Silicadol 20, 30, and 40 manufactured by Nippon Chemical Industry Co., Ltd., and organosilica sols such as methanol silica sol, MA-ST-M, MA-ST-L, IPA-ST, IPA-ST-L, IPA-ST-ZL, and EG-ST manufactured by Nissan Chemical Industries, Ltd. The solids concentration of the silica sol is also not particularly limited, but is preferably 5 to 60 mass%, more preferably 10 to 50 mass%, and even more preferably 15 to 30 mass%.

[0133] The amount of silica sol used is appropriately determined in consideration of its concentration so that the amount of silica ultimately contained in the charge transport varnish will be the blended amount of the metal oxide nanoparticles described above.

[0134] Furthermore, when the resulting thin film of the charge-transporting varnish of the present invention is used as a hole-injection layer of an organic EL device or the like, the charge-transporting varnish may contain an organosilane compound for the purpose of improving the injection properties into the hole-transporting layer and improving the life characteristics of the device. The content of the organosilane compound is usually about 1 to 30 mass % based on the total mass of the charge-transporting substance and the dopant substance. Examples of the organosilane compound include dialkoxysilane compounds, trialkoxysilane compounds, and tetraalkoxysilane compounds.

[0135] The viscosity of the charge-transporting varnish is determined as appropriate depending on the thickness of the thin film to be produced and the solid content concentration, but is typically 1 to 50 mPa·s at 25°C. In the present invention, the solid content refers to the components contained in the charge-transporting varnish other than the solvent. The solid content concentration of the charge-transporting varnish is determined as appropriate taking into account the viscosity and surface tension of the varnish, the thickness of the thin film to be produced, and the like, but is typically about 0.1 to 10.0% by mass. In consideration of improving the coatability of the varnish, it is preferably about 0.5 to 5.0% by mass, and more preferably about 1.0 to 3.0% by mass.

[0136] The method for preparing the charge-transporting varnish is not particularly limited, but examples include a method in which a charge-transporting substance and a dopant substance are dissolved in a high-polarity solvent, and then a low-polarity solvent and surface-treated metal oxide nanoparticles are added thereto, and a method in which a high-polarity solvent and a low-polarity solvent are mixed, and then a charge-transporting substance and a dopant substance are dissolved therein, and then surface-treated metal oxide nanoparticles are added thereto.

[0137] In particular, when preparing a charge-transporting varnish, from the viewpoint of obtaining a thin film with higher flatness with good reproducibility, it is desirable to use a varnish obtained by dissolving a charge-transporting substance, a dopant substance, etc. in an organic solvent and then filtering the solution using a filter or the like on the order of submicrometers.

[0138] The charge-transporting varnish described above can be used to easily produce a charge-transporting thin film, and is therefore suitable for use in producing electronic devices, particularly organic EL devices and quantum dot EL devices. In this case, the charge-transporting thin film can be formed by applying the charge-transporting varnish described above to a substrate and baking it. The method for applying the varnish is not particularly limited, and examples include dipping, spin coating, transfer printing, roll coating, brush coating, inkjet coating, spraying, and slit coating. It is preferable to adjust the viscosity and surface tension of the varnish depending on the application method.

[0139] Furthermore, the atmosphere in which the charge-transporting varnish is baked after application is not particularly limited, and a thin film with a uniform film surface and high charge transport properties can be obtained not only in an air atmosphere but also in an inert gas such as nitrogen or in a vacuum. However, depending on the type of dopant substance used, a thin film with charge transport properties can sometimes be reproducibly obtained by baking the varnish in an air atmosphere.

[0140] The baking temperature is appropriately determined within the range of about 100 to 260° C., taking into consideration the use of the resulting thin film, the degree of charge transport property to be imparted to the resulting thin film, the type and boiling point of the solvent, etc. For example, when the resulting thin film is used as a hole injection layer of an organic EL device, a temperature of about 140 to 250° C. is preferred, and about 145 to 240° C. is more preferred. However, when the above-mentioned arylamine compound is used as the charge transport material, a thin film having good charge transport property can be obtained even by baking at a low temperature of 200° C. or less. During baking, the temperature may be changed in two or more stages for the purpose of achieving more uniform film formation or promoting the reaction on the substrate. Heating may be performed using an appropriate device such as a hot plate or an oven.

[0141] The thickness of the charge transport thin film is not particularly limited, but is preferably 5 to 300 nm when used as a functional layer provided between an anode and a light-emitting layer, such as a hole injection layer, hole transport layer, or hole injection transport layer, of an organic EL device or a quantum dot EL device. Methods for changing the film thickness include changing the solids concentration in the varnish or changing the amount of solution on the substrate during application.

[0142] [3] Organic EL Devices and Quantum Dot EL Devices When the above-described charge transport thin film is applied to an organic EL device or a quantum dot EL device, the device can be configured to include the above-described charge transport thin film between a pair of electrodes. Typical configurations of organic EL devices and quantum dot EL devices include, but are not limited to, the following (a) to (f). In the configurations described below, an electron blocking layer or the like can be provided between the light-emitting layer and the anode, and a hole blocking layer or the like can be provided between the light-emitting layer and the cathode, as necessary. Furthermore, the hole injection layer, hole transport layer, or hole injection transport layer may also function as an electron blocking layer, and the electron injection layer, electron transport layer, or electron injection transport layer may also function as a hole blocking layer. Furthermore, an optional functional layer can be provided between each layer as necessary. (a) anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (b) anode / hole injection layer / hole transport layer / light-emitting layer / electron injection transport layer / cathode (c) anode / hole injection transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (d) anode / hole injection transport layer / light-emitting layer / electron injection transport layer / cathode (e) anode / hole injection layer / hole transport layer / light-emitting layer / cathode (f) anode / hole injection transport layer / light-emitting layer / cathode

[0143] The terms "hole injection layer," "hole transport layer," and "hole injection transport layer" refer to layers formed between the light-emitting layer and the anode, which have the function of transporting holes from the anode to the light-emitting layer. When only one layer of a hole-transporting material is provided between the light-emitting layer and the anode, it is the "hole injection transport layer." When two or more layers of a hole-transporting material are provided between the light-emitting layer and the anode, the layer closest to the anode is the "hole injection layer," and the remaining layers are "hole transport layers." In particular, the hole injection (transport) layer is a thin film that is excellent not only in the ability to accept holes from the anode but also in the ability to inject holes into the hole transport (light-emitting) layer. The terms "electron injection layer," "electron transport layer," and "electron injection transport layer" refer to layers formed between the light-emitting layer and the cathode, which transport electrons from the cathode to the light-emitting layer. When only one layer of an electron-transporting material is provided between the light-emitting layer and the cathode, it is the "electron injection transport layer." When two or more layers of an electron-transporting material are provided between the light-emitting layer and the cathode, the layer closest to the cathode is the "electron injection layer," and the remaining layers are "electron transport layers." The term "light-emitting layer" refers to an organic layer that emits light. When a doping system is employed, it contains a host material and a dopant material. In this case, the host material primarily promotes the recombination of electrons and holes and confines excitons within the light-emitting layer, while the dopant material efficiently emits the excitons obtained by recombination. In the case of phosphorescent devices, the host material primarily confines excitons generated by the dopant within the light-emitting layer.

[0144] The charge-transporting thin film of the present invention can be used as a functional layer provided between an anode and an emitting layer in an organic EL device or a quantum dot EL device, and is suitable as a hole-injection layer, a hole-transport layer, or a hole-injection-transport layer, more suitable as a hole-injection layer or a hole-transport layer, and even more suitable as a hole-injection layer.

[0145] Materials and methods for producing an EL device using the charge-transport varnish of the present invention include, but are not limited to, those listed below. An example of a method for producing an OLED device having a hole-injection layer made of a thin film obtained from the charge-transport varnish of the present invention is as follows. It is preferable to preliminarily clean the electrodes with alcohol, pure water, or the like, or to perform surface treatments such as UV ozone treatment or oxygen-plasma treatment, to the extent that they do not adversely affect the electrodes. A hole-injection layer made of the charge-transport thin film of the present invention is formed on an anode substrate by the above-described method. This substrate is then introduced into a vacuum deposition apparatus, and a hole-transport layer, a light-emitting layer, an electron-transport layer, an electron-transport layer / hole-blocking layer, an electron-injection layer, and a cathode metal are sequentially deposited by vapor deposition. Alternatively, instead of forming the hole-transport layer and the light-emitting layer by vapor deposition in this method, these layers are formed by a wet process using a hole-transport layer-forming composition containing a hole-transport polymer and a light-emitting layer-forming composition containing a light-emitting polymer. If necessary, an electron-blocking layer may be provided between the light-emitting layer and the hole-transport layer.

[0146] Examples of anode materials include transparent electrodes such as indium tin oxide (ITO) and indium zinc oxide (IZO), and metal anodes made of metals such as aluminum or alloys thereof, preferably those that have undergone planarization. Polythiophene derivatives and polyaniline derivatives with high charge transport properties can also be used. Other metals that can be used to make metal anodes include, but are not limited to, gold, silver, copper, indium, and alloys thereof.

[0147] Examples of materials for forming the hole transport layer include triarylamines such as (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spiro dimer, N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD), 4,4',4"-tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), and 4,4',4"-tris[1-naphthyl(phenyl)amino]triphenylamine (1-TNATA), and oligothiophenes such as 5,5"-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2"-terthiophene (BMA-3T).

[0148] Examples of materials for forming the light-emitting layer include, but are not limited to, low-molecular-weight light-emitting materials such as metal complexes (e.g., aluminum complexes of 8-hydroxyquinoline), metal complexes of 10-hydroxybenzo[h]quinoline, bisstyrylbenzene derivatives, bisstyrylarylene derivatives, metal complexes of (2-hydroxyphenyl)benzothiazole, and silole derivatives; and systems in which a light-emitting material and an electron transfer material are mixed with a polymer compound (e.g., poly(p-phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly(3-alkylthiophene), or polyvinylcarbazole. Furthermore, when the light-emitting layer is formed by vapor deposition, it may be co-deposited with a light-emitting dopant. Examples of light-emitting dopants include, but are not limited to, metal complexes (e.g., tris(2-phenylpyridine)iridium(III) (Ir(ppy)), naphthacene derivatives (e.g., rubrene), quinacridone derivatives, and fused polycyclic aromatic rings (e.g., perylene).

[0149] Examples of materials for forming the electron transport layer / hole blocking layer include, but are not limited to, oxydiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives.

[0150] Materials for forming the electron injection layer include, but are not limited to, metal oxides such as lithium oxide (LiO), magnesium oxide (MgO), and alumina (AlO), and metal fluorides such as lithium fluoride (LiF) and sodium fluoride (NaF). Cathode materials include, but are not limited to, aluminum, magnesium-silver alloys, and aluminum-lithium alloys. Materials for forming the electron blocking layer include, but are not limited to, tris(phenylpyrazole)iridium.

[0151] Examples of hole transporting polymers include poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,1'-biphenylene-4,4-diamine)], poly[(9,9-bis{1'-penten-5'-yl}fluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene)], and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]-endcapped with Examples of the polysilcisquinoxane include poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'(N-(4-sec-butylphenyl)diphenylamine)], poly(9-vinylcarbazole), and poly(4-butyl-N,N-diphenylaniline).

[0152] Examples of the light-emitting polymer include polyfluorene derivatives such as poly(9,9-dialkylfluorene) (PDAF), polyphenylenevinylene derivatives such as poly(2-methoxy-5-(2'-ethylhexoxy)-1,4-phenylenevinylene) (MEH-PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

[0153] The quantum dot material may include at least one semiconductor material selected from the group consisting of II-VI semiconductors, III-V semiconductors, I-III-VI semiconductors, IV semiconductors, and I-II-IV-VI semiconductors. Specific examples of the semiconductor material include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, CdHgZnTe, Cd dZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe; GaN, GaP, GaAs, GaSb , AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, Al PSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaIn NSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSe Examples include, but are not limited to, S, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe; Si, Ge, SiC, SiGe, AgInSe, CuGaSe, CuInS, CuGaS, CuInSe, AgInS, AgGaSe, AgGaS, C, Si, and Ge.

[0154] As described above, the charge-transporting varnish of the present invention is suitably used for forming functional layers such as a hole injection layer, a hole transport layer, and a hole injection transport layer that are provided between an anode and a light-emitting layer in an organic EL device or a quantum dot EL device. However, it can also be used for forming charge-transporting thin films in electronic devices such as organic photoelectric conversion devices, organic thin-film solar cells, organic perovskite photoelectric conversion devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic optical inspectors, organic photoreceptors, organic field quenching devices, light-emitting electrochemical cells, quantum lasers, organic laser diodes, and organic plasmon light-emitting devices.

[0155] The present invention will be explained in more detail below with reference to synthesis examples, preparation examples, working examples, and comparative examples, but the present invention is not limited to the following examples. The apparatuses used are as follows: (1) 1 H-NMR: AVANCE III HD500MHz Nuclear Magnetic Resonance Spectrometer manufactured by Bruker (2) Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn): Tosoh Corporation GPC device HLC-8320GPC (column: Shodex KD-805, column temperature: 50 ° C., detector: UV detector (254 nm) and RI detector, eluent: DMF, LiBr (30 mM), phosphoric acid (30 mM), THF (1%), column flow rate: 1 mL / min, standard sample: polystyrene) (3) Cleaning of substrate: Choshu Sangyo Co., Ltd., substrate cleaning device (low pressure plasma type) (4) Application of charge transport varnish: Mikasa Co., Ltd., spin coater MS-A100 (5) Measurement of contact angle: Kyowa Interface Science Co., Ltd., fully automatic contact angle meter DM-700 (6) Preparation of hole-only device (HOD) and organic EL element: Multifunctional deposition system C-E2L1G1-N manufactured by Choshu Sangyo Co., Ltd. (7) Measurement of luminance, etc. of hole-only device (HOD) and organic EL element: Multi-channel IVL measurement device manufactured by EHC Co., Ltd.

[0156] [1] Synthesis of Raw Material Compounds (Monomers) [Synthesis Example 1] Synthesis of Compound 1 Compound 1, a sodium arylsulfonate compound represented by the following formula, was synthesized according to the method described in WO 2023 / 008176.

[0157]

[0158] [Synthesis Example 2] Synthesis of Compound 2

[0159] Sodium hydride (55% by mass dispersion in liquid paraffin, 2.97 g, 68.0 mmol, manufactured by Kanto Chemical Co., Inc.) was added to a four-necked recovery flask, and the atmosphere was replaced with nitrogen. Then, dehydrated tetrahydrofuran (hereinafter referred to as "THF", 65 ml, manufactured by Kanto Chemical Co., Inc.) was added and cooled to 0°C. A mixed solution of 2,2,3,3,3-pentafluoro-1-propanol (8.50 g, 56.7 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and dehydrated THF (32 ml) was added dropwise, and the mixture was stirred at 0°C for 30 minutes. A mixed solution of 2,3,4,5,6-pentafluorostyrene (10.0 g, 51.5 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and dehydrated THF (32 ml) was then added dropwise, and the mixture was stirred at 0°C for 30 minutes. The mixture was then stirred at room temperature for 4 hours. The reaction solution was slowly added dropwise to water (310 g) under ice cooling. The resulting mixed solution was subjected to a liquid separation treatment with ethyl acetate (130 mL x 3). The resulting organic layer was dried over anhydrous sodium sulfate. The dried solution was evaporated under reduced pressure to remove the solvent, and the resulting residue was purified by vacuum distillation (0.4 mmHg, 42°C) to obtain Compound 2 (13.6 g, 42.0 mmol) as a pale yellow oil (yield 82%). 1 The H-NMR spectrum (measurement solvent: dimethylsulfoxide-d) is shown in FIG.

[0160] [2] Polymer Synthesis [Example 1-1] Synthesis of Polymer A

[0161] Compound 1 (2.04 g, 3.91 mmol) obtained in Synthesis Example 1, Compound 2 (0.54 g, 1.68 mmol) obtained in Synthesis Example 2, 2,2'-azobis(isobutyronitrile) (hereinafter referred to as "AIBN", 46 mg, 0.28 mmol, manufactured by Kanto Chemical Co., Inc.), and dimethyl sulfoxide (hereinafter referred to as "DMSO", 25.8 g, manufactured by Junsei Chemical Co., Ltd.) were added to a three-necked recovery flask. The solution was degassed and then stirred at room temperature under a nitrogen atmosphere until Compound 1 and Compound 2 were completely dissolved. The mixture was then heated and stirred at 80°C for 8 hours. The reaction solution was concentrated and added dropwise to a mixed solvent (130 g) of methanol / ethyl acetate (1 wt / 3.5 wt), followed by stirring at room temperature for 1 hour. The precipitated solid was then collected by suction filtration and washed with a mixed solvent of methanol / ethyl acetate (1 wt / 3.5 wt). The washed solid was dried under reduced pressure to obtain Intermediate Polymer A (2.0 g). To a flask, intermediate polymer A (2.0 g) and a mixed solvent (30 g) of methanol / water (1 wt / 1 wt) were added and stirred at room temperature. Then, 9.1 mL of a cation exchange resin (Dowex Monosphere 650C, manufactured by Sigma-Aldrich) was added and stirred at room temperature for 30 minutes. The cation exchange resin was removed by suction filtration, and the filtrate was dried under reduced pressure to remove the solvent, yielding polymer A (1.74 g) as an orange solid. Mn = 2300, Mw = 6550, Mw / Mn = 2.85 (GPC).

[0162] [Example 1-2] Synthesis of Polymer B

[0163] Compound 1 (2.01 g, 3.85 mmol) obtained in Synthesis Example 1, Compound 2 (0.31 g, 0.96 mmol) obtained in Synthesis Example 2, AIBN (39 mg, 0.24 mmol), and DMSO (23.2 g) were added to a three-necked recovery flask. The solution was degassed and then stirred at room temperature under a nitrogen atmosphere until Compound 1 and Compound 2 were completely dissolved. The mixture was then heated and stirred at 80°C for 8 hours. The reaction solution was concentrated and added dropwise to a mixed solvent (140 g) of methanol / ethyl acetate (1 wt / 3.5 wt), followed by stirring at room temperature for 1 hour. The precipitated solid was then collected by suction filtration and washed with a mixed solvent of methanol / ethyl acetate (1 wt / 3.5 wt). The washed solid was dried under reduced pressure to obtain Intermediate Polymer B (1.82 g). Intermediate Polymer B (1.82 g) and a mixed solvent (30 g) of methanol / water (1 wt / 1 wt) were added to the flask, followed by stirring at room temperature. Then, 9.1 mL of a cation exchange resin (Dowex Monosphere 650C) was added, and the mixture was stirred at room temperature for 30 minutes. The cation exchange resin was removed by suction filtration, and the filtrate was dried under reduced pressure to remove the solvent, yielding Polymer B (1.55 g) as an orange solid. Mn = 1670, Mw = 4470, Mw / Mn = 2.68 (GPC).

[0164] [Comparative Example 1-1] Synthesis of Polymer C

[0165] Compound 1 (1.50 g, 2.87 mmol) obtained in Synthesis Example 1, 2,3,4,5,6-pentafluorostyrene (0.24 g, 1.24 mmol), AIBN (34 mg, 0.21 mmol), and DMSO (17.4 g) were added to a three-necked recovery flask. The solution was degassed and then stirred at room temperature under a nitrogen atmosphere until the monomer was completely dissolved. The mixture was then heated and stirred at 80°C for 9 hours. The reaction solution was concentrated and added dropwise to a mixed solvent (90 g) of methanol / ethyl acetate (1 wt / 3.5 wt), followed by stirring at room temperature for 1 hour. The precipitated solid was then collected by suction filtration and washed with a mixed solvent of methanol / ethyl acetate (1 wt / 3.5 wt). The washed solid was dried under reduced pressure to obtain intermediate polymer C (1.27 g). Intermediate polymer C (1.27 g) and a mixed solvent (20 g) of methanol / water (1 wt / 1 wt) were added to the flask and stirred at room temperature. Then, 6.4 mL of a cation exchange resin (Dowex Monosphere 650C) was added, and the mixture was stirred at room temperature for 30 minutes. The cation exchange resin was removed by suction filtration, and the filtrate was dried under reduced pressure to remove the solvent, yielding Polymer C (1.08 g) as an orange solid. Mn = 1910, Mw = 4370, Mw / Mn = 2.29 (GPC).

[0166] [3] Preparation of composition for preparing charge-transporting varnish [Preparation Example 1-1] 8.75 g of 1,3-dimethyl-2-imidazolidinone (manufactured by Kanto Chemical Co., Ltd.; the same applies hereinafter) and 0.75 g of n-butylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 0.5 g of an amine adduct of a polythiophene derivative, which is a polymer containing a repeating unit represented by formula (1a), synthesized sequentially according to the methods described in U.S. Pat. No. 8,017,241 and WO 2016 / 171935, and the mixture was stirred at 80° C. for 3 hours using a hot stirrer to obtain a solution in which the polythiophene was dissolved.

[0167]

[0168] Preparation Example 1-2 50 g of ST-OS (manufactured by Nissan Chemical Industries, Ltd.), which is a water-dispersed silica sol, and dipropylene glycol monomethyl ether (manufactured by Kanto Chemical Co., Ltd.; the same applies hereinafter) were placed in a recovery flask, and the water contained in the ST-OS was solvent-substituted with dipropylene glycol monomethyl ether using an evaporator, thereby obtaining a dipropylene glycol monomethyl ether-dispersed silica sol (silica concentration 15.7% by mass).

[0169] [4] Preparation of Charge-Transporting Varnish [Example 2-1] 1,3-dimethyl-2-imidazolidinone (hereinafter referred to as "DMI", 2.37 g), dipropylene glycol (3.38 g, manufactured by Junsei Chemical Co., Ltd., the same applies hereinafter), dipropylene glycol monomethyl ether (2.17 g), and Polymer A (45 mg) synthesized in Example 1-1 were added to a recovery flask and stirred at 50°C for 1 hour using a stirrer. Then, 0.60 g of the polythiophene solution obtained in Preparation Example 1-1 was added, and the mixture was stirred at room temperature for 30 minutes. Then, 1.44 g of the dipropylene glycol monomethyl ether-dispersed silica sol obtained in Preparation Example 1-2 was added, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge-transporting varnish.

[0170] Example 2-2: DMI (2.37 g), dipropylene glycol (3.38 g), dipropylene glycol monomethyl ether (2.17 g), and polymer B (45 mg) synthesized in Example 1-2 were added to a recovery flask and stirred at 50°C for 1 hour using a stirrer. Then, 0.60 g of the polythiophene solution obtained in Preparation Example 1-1 was added, and the mixture was stirred at room temperature for 30 minutes. Then, 1.44 g of the dipropylene glycol monomethyl ether-dispersed silica sol obtained in Preparation Example 1-2 was added, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge-transporting varnish.

[0171] Example 2-3: DMI (3.02 g), 2,3-butanediol (4.02 g, manufactured by Kanto Chemical Co., Inc., the same applies hereinafter), dipropylene glycol monomethyl ether (2.71 g), and polymer A (0.17 g) synthesized in Example 1-1 were added to a recovery flask and stirred at 50°C for 1 hour using a stirrer. Subsequently, 0.08 g of the aniline compound represented by formula (2a), synthesized according to the method described in WO 2013 / 084664, was added, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge-transporting varnish.

[0172]

[0173] Example 2-4: DMI (3.02 g), 2,3-butanediol (4.02 g), dipropylene glycol monomethyl ether (2.71 g), and polymer B (0.17 g) synthesized in Example 1-2 were added to a recovery flask and stirred at 50°C for 1 hour using a stirrer. Then, 0.08 g of the aniline compound represented by formula (2a) was added, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge-transporting varnish.

[0174] [Comparative Example 2-1] DMI (2.37 g), dipropylene glycol (3.38 g), dipropylene glycol monomethyl ether (2.17 g), and polymer C (45 mg) synthesized in Comparative Example 1-1 were added to a recovery flask and stirred at 50°C for 1 hour using a stirrer. Then, 0.60 g of the polythiophene solution obtained in Preparation Example 1-1 was added, and the mixture was stirred at room temperature for 30 minutes. Then, 1.44 g of the dipropylene glycol monomethyl ether-dispersed silica sol obtained in Preparation Example 1-2 was added, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge-transporting varnish.

[0175] [Comparative Example 2-2] DMI (3.02 g), 2,3-butanediol (4.02 g), dipropylene glycol monomethyl ether (2.71 g), and polymer C (0.17 g) synthesized in Comparative Example 1-1 were added to a recovery flask and stirred at 50°C for 1 hour using a stirrer. Then, aniline compound (0.08 g) represented by formula (2a) was added, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was filtered through a PP syringe filter with a pore size of 0.2 μm to obtain a charge-transporting varnish.

[0176] [5] Evaluation of Water Contact Angle on Charge-Transporting Thin Film [Example 3-1] The charge-transporting varnish obtained in Example 2-1 was applied to an ITO substrate using a spin coater and then baked in air at 120°C for 1 minute. The substrate was then baked in air at 230°C for 15 minutes to form a uniform thin film with a thickness of 65 nm on the ITO substrate. The ITO substrate used was a 50 mm x 50 mm x 0.7 mm glass substrate on which indium tin oxide (ITO) was patterned to a thickness of 50 nm. Prior to use, impurities on the surface were removed using an O2 plasma cleaning device (150 W, 30 seconds).

[0177] [Examples 3-2 to 3-4, Comparative Examples 3-1 to 3-2] A uniform thin film having a thickness of 65 nm was formed on an ITO substrate in the same manner as in Example 3-1, except that the charge-transporting varnish was changed to the charge-transporting varnishes obtained in Examples 2-2 to 2-4 and Comparative Examples 2-1 and 2-2, respectively.

[0178] For the charge-transporting thin films formed on the ITO substrates in Examples 3-1 to 3-4 and Comparative Examples 3-1 and 3-2, the water contact angle on each thin film was measured using a contact angle meter. The amount of water droplet was 1.1 μL, and the contact angle was measured 7 seconds after the droplet landed. The results are shown in Table 1.

[0179]

[0180] As shown in Table 1, when the results of Examples 3-1 to 3-2 and Comparative Example 3-1 are compared with the results of Examples 3-3 to 3-4 and Comparative Example 3-2, it is found that the water contact angle on the thin film formed from the charge transport varnish using polymer A or polymer B is higher than the water contact angle on the thin film formed from the charge transport varnish using polymer C. One of the reasons for this is considered to be that polymer A and polymer B contain fluorinated alkyl groups with low surface energy in their molecules, and therefore, when a charge transport thin film is formed, they are more likely to be unevenly distributed on the film surface than polymer C.

[0181] [6] Fabrication and Evaluation of Hole-Only Device (HOD) [Example 4-1] The charge-transporting varnish obtained in Example 2-1 was applied to an ITO substrate using a spin coater, and then dried at 120°C for 1 minute in an air atmosphere. The substrate was then baked at 230°C for 15 minutes in an air atmosphere to form a uniform thin film of 65 nm on the ITO substrate. The ITO substrate used was a 25 mm x 25 mm x 0.7 mm glass substrate with a patterned ITO film of 150 nm thickness formed on its surface. Prior to use, impurities on the surface were removed using an O2 plasma cleaning device (150 W, 30 seconds) (hereinafter the same). The ITO substrate on which the thin film had been formed was then vacuum-evaporated (vacuum degree 1.0 x 10 -5 Using a vacuum oven (2000 W), α-NPD (N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. was deposited to a thickness of 80 nm at a deposition rate of 0.2 nm / sec. Next, aluminum was deposited to a thickness of 80 nm at a deposition rate of 0.2 nm / sec to obtain HOD.

[0182] To prevent deterioration of characteristics due to the influence of oxygen, water, etc. in the air, the HOD was sealed with a sealing substrate before its characteristics were evaluated. Sealing was performed as follows. In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -76°C or less, the organic EL element was placed between sealing substrates, and the sealing substrates were bonded together with an adhesive (Moresco Moisture Cut WB90US(P) manufactured by MORESCO Corporation). At this time, a moisture scavenger (HD-071010W-40 manufactured by DYNIC Co., Ltd.) was placed inside the sealing substrate together with the HOD. The bonded sealing substrates were irradiated with UV light (wavelength: 365 nm, irradiation dose: 6,000 mJ / cm).2 ), and then annealed at 80°C for 1 hour to cure the adhesive.

[0183] [Examples 4-2 to 4-4, Comparative Examples 4-1 to 4-2] HODs were prepared in the same manner as in Example 4-1, except that the charge-transporting varnish was changed to the charge-transporting varnishes obtained in Examples 2-2 to 2-4 and Comparative Examples 2-1 to 2-2, respectively.

[0184] The current-voltage characteristics were evaluated for each of the devices fabricated in Examples 4-1 to 4-4 and Comparative Examples 4-1 and 4-2. Specifically, the current density (mA / cm) was measured when a voltage was applied to the fabricated HOD from −5 V to +5 V in 0.25 V increments. 2 The current density when a voltage of +5 V was applied to each element is shown in Table 2.

[0185]

[0186] As shown in Table 2, when the results of Examples 4-1 to 4-2 and Comparative Example 4-1 are compared with those of Examples 4-3 to 4-4 and Comparative Example 4-2, it is found that the HOD using the charge transport varnish made with polymer A or polymer B exhibits a higher current amount than the HOD using the charge transport varnish made with polymer C. This result is thought to be due to the fact that when a charge transport thin film is formed from each charge transport varnish, polymer A or polymer B, which functions as a dopant, is more likely to be unevenly distributed on the film surface than when polymer C is used, and therefore the charge transport substance present on the film surface is efficiently doped, thereby improving the hole injection property into the NPB film formed on the upper layer.

[0187] [7] Preparation and Evaluation of Organic EL Device [Example 5-1] The charge transporting varnish obtained in Example 2-1 was applied to an ITO substrate using a spin coater, and then dried at 120°C for 1 minute in an air atmosphere. The substrate was then baked at 230°C for 15 minutes in an air atmosphere to form a uniform thin film of 65 nm on the ITO substrate. The ITO substrate on which the thin film had been formed was then subjected to a vapor deposition apparatus (vacuum degree 1.0 x 10 -5A 30-nm film of α-NPD was formed at a deposition rate of 0.2 nm / sec using a fluorine-containing fluoride (PA) solution. Next, a 10-nm film of the electron blocking material HTEB-01 (Kanto Chemical Co., Ltd.) was formed. Next, the emitting layer host material NS60 (Nippon Steel & Sumikin Chemical Co., Ltd.) and the emitting layer dopant material Ir(ppy)3 were co-deposited. The deposition rate was controlled so that the Ir(ppy)3 concentration was 6%, resulting in a 40-nm layer. Next, thin films of Alq3, lithium fluoride, and aluminum were sequentially deposited to obtain an organic EL device. The deposition rates were 0.2 nm / sec for Alq3 and aluminum, and 0.02 nm / sec for lithium fluoride, resulting in film thicknesses of 20 nm, 0.5 nm, and 80 nm, respectively.

[0188]

[0189] In order to prevent deterioration of characteristics due to the influence of oxygen, water, etc. in the air, the organic EL elements were sealed with sealing substrates before their characteristics were evaluated. Sealing was performed according to the following procedure. In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -76°C or less, the organic EL elements were placed between sealing substrates, and the sealing substrates were bonded together with an adhesive (Moresco Moisture Cut WB90US(P) manufactured by MORESCO Corporation). At this time, a moisture scavenger (HD-071010W-40 manufactured by DYNIC Corporation) was placed inside the sealing substrates together with the organic EL elements. The bonded sealing substrates were irradiated with UV light (wavelength: 365 nm, irradiation dose: 6,000 mJ / cm). 2 ) and then annealed at 80°C for 1 hour to harden the adhesive.

[0190] [Examples 5-2 to 5-4, Comparative Examples 5-1 to 5-2] Organic EL devices were produced in the same manner as in Example 5-1, except that the charge-transporting varnish was changed to the charge-transporting varnishes obtained in Examples 2-2 to 2-4 and Comparative Examples 2-1 and 2-2, respectively.

[0191] For each of the elements produced in Examples 5-1 to 5-4 and Comparative Examples 5-1 and 5-2, a luminance of 10,000 cd / m 2 The driving voltage, current density, luminous efficiency, and luminance LT80 (initial luminance 10,000 cd / m 2The time required for the temperature to decay to 80% was measured. The results are shown in Table 3.

[0192]

[0193] As shown in Table 3, comparing the results of Examples 5-1 and 5-2 with Comparative Example 5-1 and the results of Examples 5-3 and 5-4 with Comparative Example 5-2, it can be seen that the organic EL element using the charge-transporting varnish containing polymer A and polymer B exhibits a lower driving voltage, higher efficiency, and longer life than the organic EL element using the charge-transporting crocodile water containing polymer C. This result correlates with the HOD results described above, and it is believed that the charge-transporting thin film obtained from the charge-transporting varnish containing polymer A or polymer B has improved hole injection properties into the hole-transporting layer formed on top compared to the charge-transporting thin film obtained from the charge-transporting varnish containing polymer C, leading to improved organic EL element characteristics.

Claims

1. A fluorinated arylsulfonic acid polymer compound comprising repeating units represented by the following formula (1) and formula (2): [In the formula, Ar F1 and Ar F2 each independently represents a fluorinated arylene group; 1 and X 2 each independently represents O, S, NH, CONH, or NHCO; Ar S represents an aryl group having at least one SOR group on the ring (R represents a hydrogen atom or an alkali metal atom); R 1 represents an alkyl group having 3 to 10 carbon atoms substituted with at least one fluorine atom, R 2 and R 3 each independently represents a hydrogen atom or a methyl group.

2. The Ar F1 and Ar F2 The fluorinated arylsulfonic acid polymer compound according to claim 1, wherein is a perfluoroarylene group.

3. The Ar F1 and Ar F2 The fluorinated arylsulfonic acid polymer compound according to claim 2, wherein is a tetrafluorophenylene group.

4. The Ar S 2. The fluorinated aryl sulfonic acid polymer compound of claim 1, wherein is an aryl group having two or more of said SO3R groups on the ring.

5. The Ar S The fluorinated arylsulfonic acid polymer compound of claim 4, wherein is a naphthyl group having two or more of said SO3R groups on the ring.

6. The above X 1 and X 2 The fluorinated arylsulfonic acid polymer compound of claim 1 , wherein 7. A dopant material comprising the fluorinated arylsulfonic acid polymer compound of claim 1.

8. A charge transporting varnish comprising a charge transporting material, the dopant material according to claim 7, and a solvent.

9. The charge transporting varnish according to claim 8, wherein said charge transporting substance is an arylamine derivative or a thiophene derivative.

10. A charge-transporting thin film obtained from the charge-transporting varnish according to claim 8 or 9.

11. An electronic device comprising the charge transporting thin film according to claim 10.

12. The electronic device according to claim 11, wherein the charge transporting thin film is a hole injection layer or a hole transport layer.

13. The electronic device according to claim 11, which is an organic electroluminescence device or a quantum dot electroluminescence device.

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