TWI650307B - Charge transport varnish - Google Patents

Abstract

A charge-transporting varnish containing a charge-transporting substance and a doping substance, such as an organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent, such as 4-chlorophenyltrimethoxysilane, and an organic solvent, can impart flatness, A thin film that is excellent in charge transport properties and coatability of an upper layer material and exhibits excellent brightness characteristics when applied to an organic EL device.

Description

Charge transport varnish

The present invention relates to a charge-transporting varnish.

In the field of displays or lighting, the practical use of organic electroluminescence (EL) elements is highly anticipated. Therefore, various developments have been made on materials or element structures for the purpose of low driving voltage, high brightness, and long life.

A plurality of functional thin films are used in organic EL devices. One of the hole injection layers is responsible for the charge exchange between the anode and the hole transport layer or the light-emitting layer. In order to achieve the low driving voltage and high voltage of the organic EL device, Shows important functions in brightness.

The method for forming the hole injection layer is roughly different between a dry process represented by a vapor deposition method and a wet process represented by a spin coating method. When comparing these processes, the wet process can more efficiently produce large-area and high-flatness thin films, so it is particularly in the field of displays, not on the formation of the hole injection layer, and on the hole transport The formation of upper layers such as layers and light-emitting layers is also more commonly performed by a wet process (see Patent Document 1).

Under such circumstances, the present inventors have developed various charge-transporting varnishes containing an aniline derivative as a charge-transporting substance (refer to Patent Documents 2 to 7), but there is still a demand for further improvement of the hole injection layer application. Wet process materials.

In particular, since it can impart brightness characteristics to an organic EL element, high uniformity is required not only for the hole injection layer but also for the hole transport layer (see Patent Document 8), and there is a demand for a film having excellent flatness and a charge transport property. And, on this film, a material having excellent coatability of a hole transporting layer or a light emitting layer formed by a wet process can also be realized.

[Prior technical literature] [Patent Literature]

[Patent Document 1] JP 2008-78181

[Patent Document 2] International Publication No. 2006/025342

[Patent Document 3] International Publication No. 2008/032616

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

[Patent Document 5] International Publication No. 2010/041701

[Patent Document 6] International Publication No. 2010/058777

[Patent Document 7] International Publication No. 2013/042623

[Patent Document 8] JP 2008-27646

The present invention has been made in view of the above circumstances, and its purpose The purpose is to provide a charge-transporting varnish, which is a thin film which can impart high flatness and high charge-transportation properties, and also has excellent coatability of an upper layer material, and can exhibit excellent brightness characteristics when applied to an organic EL element.

In order to achieve the above-mentioned object, the present inventors have conducted careful and repeated research and found that the use of a charge-transporting varnish containing a charge-transporting substance, a doping substance, and an organic silane compound containing a chlorine atom can produce a flatness, The present invention has completed a thin film having excellent charge-transporting properties and excellent coatability of an upper layer material, and achieving good brightness characteristics when the film is applied to an organic EL element.

In addition, Patent Documents 3 and 4 have disclosed that films obtained from a charge-transporting varnish composed of an oligoaniline derivative, an electron-accepting or hole-accepting dopant substance, a silane compound, and an organic solvent, or have the same. An organic EL device, but does not specifically disclose the silane compound used in the present invention or the charge-transporting varnish containing the same, and there is no description or teaching of the film obtained from the varnish with excellent coating properties for the material on the upper layer. .

That is, the present invention provides the following: 1. A charge-transporting varnish comprising a charge-transporting substance, a doping substance, an organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent, and an organic solvent; 2. The charge-transporting varnish of 1, wherein the organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent is a trialkoxysilane compound substituted with a chlorine-containing monovalent hydrocarbon group; 3. The charge-transporting varnish according to 1 or 2, wherein the aforementioned chlorine-containing monovalent hydrocarbon group is at least one selected from a chlorinated alkyl group having 1 to 20 carbon atoms and a chlorinated aryl group having 6 to 20 carbon atoms; The charge-transporting varnish according to any one of 1 to 3, wherein the organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent is chlorophenyltrialkoxysilane; 5. The charge transport according to any one of 1 to 4 Varnish, wherein the aforementioned doping substance is heteropoly acid; 6. a charge transporting thin film, which is produced using the charge transporting varnish according to any one of 1 to 5; 7. an electronic device, which has A charge-transporting film such as 6 .; 8. An organic electroluminescence device having a charge-transporting film such as 6 .; 9. An organic electro-luminescence device according to 8, wherein the aforementioned charge-transporting film is a hole injection layer Or hole transport layer; 10. A method for manufacturing a charge transporting film, characterized in that the charge transporting varnish according to any one of 1 to 5 is coated on a substrate and the solvent is evaporated.

The thin film obtained from the charge-transporting varnish of the present invention has high flatness and high charge-transporting property, and when the thin-film is applied to a hole injection layer, an organic EL device capable of achieving good brightness characteristics can be obtained.

The film obtained from the charge-transporting varnish of the present invention It contains a monovalent hydrocarbon group containing a chlorine atom derived from a silane compound, but the contact angle of the solvent used for the material on the surface of the silane compound is not different from the film obtained without adding a silane compound.

In addition, the charge-transporting varnish of the present invention can produce a film having excellent charge-transportability with good reproducibility even when various wet processes capable of forming a large-area film, such as a spin coating method or a slit coating method, are used. It can also fully respond to the progress in the field of organic EL elements in recent years.

The thin film obtained from the charge-transporting varnish of the present invention can also be used as an anode buffer layer for an anti-charge film or an organic thin-film solar cell.

Hereinafter, the present invention will be described in more detail.

The charge-transporting varnish of the present invention includes a charge-transporting substance, a doping substance, an organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent, and an organic solvent.

Here, the charge transportability is synonymous with conductivity and also with hole transportability. The charge-transporting substance may be a substance having a charge-transporting property itself, or a substance having a charge-transporting property when used with a dopant substance (electron-capacitive substance). The charge-transporting varnish may be one having a charge-transporting property by itself, or a solid film system obtained therefrom.

The charge-transporting substance used in the present invention is not particularly limited as long as it is a substance having a charge-transporting substance. For example, charge-transporting monomers and charge-transporting oligomers used in the field of organic EL devices can be suitably used. Materials or polymers, but from the reproducible modulation From the viewpoint of a charge-transporting varnish of a highly flat charge-transporting film, a charge-transporting oligomer is preferred.

Specific examples of the charge-transporting oligomer include oligoaniline derivatives, N, N'-diarylbenzidine derivatives, and N, N, N ', N'-tetraarylbenzidine derivatives. Various holes such as aniline derivatives (arylamine derivatives), oligothiophene derivatives, thienothiophene derivatives, thiophene benzothiophene derivatives, thiophene derivatives, etc. Among the transportable substances, arylamine derivatives and thiophene derivatives are preferred, and arylamine derivatives are more preferred.

In the present invention, the molecular weight of the charge-transporting oligomer is not particularly limited as long as it is soluble in an organic solvent, and is usually 200 to 9,000.

From the viewpoint of obtaining a high charge-transporting film with excellent reproducibility, the molecular weight is preferably 300 or more, and more preferably 400 or more. It imparts a uniform varnish with a high flatness film from the modulation reproducibility. From a viewpoint, 8,000 or less is preferable, 7,000 or less is preferable, 6,000 or less is more preferable, and 5,000 or less is more preferable.

From the viewpoint of preventing separation of the charge-transporting substance during the thin film formation, it is preferable that the charge-transporting substance such as a charge-transporting oligomer does not have a molecular weight distribution (dispersion degree is 1) (that is, a single molecular weight is preferred) .

Specific examples of the aniline derivative include those represented by the formula (1), but are not limited thereto.

In formula (1), X ¹ represents -NY ^1- , -O-, -S-,-(CR ⁷ R ⁸ ) _L- , or a single bond, but when m1 or m2 is 0, it represents -NY ^1- .

Lines Y ¹ each independently represent a hydrogen atom, an alkyl group may be substituted with Z ¹ of the carbon atoms of 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms of the alkynyl group of 2 to 20, Z ^2, or may be substituted to carbon An aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms.

Specific examples of the alkyl group having 1 to 20 carbon atoms may be any of linear, branched, and cyclic, and examples thereof include methyl, ethyl, n-propyl, isopropyl, Carbon of n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, etc. 1 to 20 linear or branched chain alkyl groups; cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, Bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl, etc. cyclic alkyl groups having 3 to 20 carbon atoms.

Specific examples of the alkenyl group having 2 to 20 carbon atoms include vinyl, n-1-propenyl, n-2-propenyl, 1-methylvinyl, n-1-butenyl, and n 2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl , 1-methyl-2-propenyl, n-1-pentenyl, n-1-decenyl, n-1-icosenyl, and the like.

Specific examples of the alkynyl group having 2 to 20 carbon atoms include, for example, 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-pentadeynyl, n-1-icosynyl and the like.

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-phenanthrene, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl and the like.

Specific examples of the heteroaryl group having 2 to 20 carbon atoms include 2-thienyl, 3-thienyl, 2-furyl, 3-furyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isooxazolyl, 4-isooxazolyl, 5-isooxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4- Isothiazolyl, 5-isothiazolyl, 2-imidazolyl, 4-imidazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, and the like.

R ⁷ and R ⁸ each independently represent a hydrogen atom; a halogen atom; a nitro group; a cyano group; an amine group; an aldehyde group; a hydroxyl group; a sulfhydryl group; a sulfonic acid group; a carboxylic acid group; a carbon number of 1 to 20 which can be substituted by Z ¹ An alkyl group, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms which may be substituted by Z ² ; or -NHY ² 、 -NY ³ Y ⁴ 、 -C (O) Y ⁵ 、 -OY ⁶ 、 -SY ⁷ 、 -SO ₃ Y ⁸ 、 -C (O) OY ⁹ 、 -OC (O) Y ¹⁰ 、 -C (O ) NHY ¹¹ or C (O) NY ¹² Y ¹³ radical.

Y ² to Y ¹³ are independent of each other and represent 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 that can be substituted with Z ¹ , or a carbon group that can be substituted with Z ² An aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms.

Z ¹ is a halogen atom, a nitro group, a cyano group, an amine group, an aldehyde group, a hydroxyl group, a sulfhydryl group, a sulfonic acid group, a carboxylic acid group, or an aryl group having 6 to 20 carbon atoms or 2 to 2 carbon atoms which may be substituted by Z ³ 20's heteroaryl.

Z ² is a halogen atom, a nitro group, a cyano group, an amine group, an aldehyde group, a hydroxyl group, a sulfhydryl group, a sulfonic acid group, a carboxylic acid group, or an alkyl group having 1 to 20 carbon atoms and 2 to 2 carbon atoms which can be substituted by Z ³ Alkenyl group of 20 or alkynyl group with 2 to 20 carbon atoms.

Z ³ is a halogen atom, a nitro group, a cyano group, an amine group, an aldehyde group, a hydroxyl group, a mercapto group, a sulfonic acid group, or a carboxylic acid group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Other examples of the alkyl group, alkenyl group, alkynyl group, aryl group, and heteroaryl group of R ⁷ , R ^8, and Y ² to Y ¹³ include the same ones described above.

Among these, as R ⁷ and R ⁸ , a hydrogen atom or an alkyl group having 1 to 20 carbon atoms substituted with Z ^{1 is} preferred, and a hydrogen atom or a methyl group substituted with Z ¹ is more preferred. All are hydrogen atoms.

L represents the number of repeating units of the divalent alkylene represented by-(CR ⁷ R ⁸ )-, which is an integer of 1 to 20, but 1 to 10 is preferred, 1 to 5 is preferred, and 1 to 2 is better, 1 is best.

Moreover, when L is 2 or more, the plural R ⁷ may be the same as or different from each other, and the plural R ⁸ may be the same or different from each other.

In particular, X ¹ is preferably -NY ¹ -or a single bond. In addition, Y ¹ is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may be substituted by Z ¹ , more preferably a hydrogen atom or a methyl group which may be substituted by Z ¹ , and most preferably a hydrogen atom.

R ¹ to R ⁴ represent hydrogen atom independently; halogen atom; nitro group; cyano group; amine group; aldehyde group; hydroxyl group; mercapto group; sulfonic acid group; carboxylic acid group; carbon number which can be substituted by Z ^{1 is} 1-20 An alkyl group, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms which may be substituted by Z ² ; or -NHY ² 、 -NY ³ Y ⁴ 、 -C (O) Y ⁵ 、 -OY ⁶ 、 -SY ⁷ 、 -SO ₃ Y ⁸ 、 -C (O) OY ⁹ 、 -OC (O) Y ¹⁰ 、 -C (O ) NHY ¹¹ or C (O) NY ¹² Y ¹³ (Y ² to Y ¹³ represents the same meaning as above). Examples of such a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and a heteroaryl group include the same as those described above.

In particular, in Formula (1), R ¹ to R ⁴ are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , or an aromatic group having 6 to 14 carbon atoms which may be substituted with Z ² The radical is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 10 carbon atoms which can be substituted by a fluorine atom, and most preferably a hydrogen atom.

And, R ⁵ and R ⁶ based hydrogen atom, a halogen atom, Z ¹ may be substituted with the alkyl group having 1 to 10 carbon atoms, the substituents of Z ² may be 6 to 14 carbon atoms of an aryl group, or may be substituted with Z ² A diphenylamine group (Y ³ and Y ⁴ are phenyl groups which can be substituted by Z ² , ie, -NY ³ Y ⁴ group) is preferred. A hydrogen atom, a fluorine atom, or a diphenylamine which can be substituted by a fluorine atom is preferred. The group is preferably a hydrogen atom or a diphenylamino group at the same time.

In addition, among these, R ¹ to R ⁴ are a hydrogen atom, a fluorine atom, and an alkyl group having 1 to 10 carbon atoms which may be substituted with a fluorine atom; R ⁵ and R ⁶ are a hydrogen atom, a fluorine atom, and a fluorine atom; Atomically substituted diphenylamino, X ¹ is -NY ¹ -or a single bond, and Y ¹ is preferably a hydrogen atom or a combination of methyl groups. R ¹ to R ⁴ are hydrogen atoms, and R ⁵ and R ^{6 are} simultaneously Is a hydrogen atom or a diphenylamino group, and X ¹ is -NH- or a combination of single bonds is preferred.

In formula (1), m1 and m2 independently represent an integer of 0 or more, and satisfy 1 ≦ m1 + m2 ≦ 20, but if the balance between the charge transportability of the obtained film and the solubility of the aniline derivative is taken into account, Then it is better to satisfy 2 ≦ m1 + m2 ≦ 8, it is better to satisfy 2 ≦ m1 + m2 ≦ 6, and it is better to satisfy 2 ≦ m1 + m2 ≦ 4.

In particular, the Y ¹ ~ Y ¹³ and R ¹ ~ R ^8, substituent group Z ¹ line or a halogen atom Z ³ may be substituted having 6 to 20 carbon atoms of the aryl group preferably, a halogen atom or may be substituted with Z ³ Phenyl is preferred, and the absence (ie, unsubstituted) is most preferred.

And, based substituent group Z ² may be preferably a halogen atom or an alkyl substituent of Z ³ 1 to 20 carbon atoms, the halogen atom, or an alkyl group substituted by Z ³ of the carbon atoms is preferably of 1 to 4 It is best to be absent (ie, non-substituted).

In addition, Z ³ is more preferably a halogen atom, more preferably a fluorine atom, and most preferably non-existent (that is, non-substituted).

In Y ¹ to Y ¹³ and R ¹ to R ⁸ , the carbon number of the alkyl group, alkenyl group, and alkynyl group is preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less.

The carbon number of the aryl group and the heteroaryl group is preferably 14 or less, more preferably 10 or less, and even more preferably 6 or less.

Moreover, the method for synthesizing the aniline derivative is not particularly limited, and examples include Bulletin of Chemical Society of Japan, 67, pp. 1749-1752, (1994), Synthetic Metals, 84, pp. 119- 120, (1997), Thin Solid Films, 520 (24), pp. 7157-7163, (2012), International Publication No. 2008 / Methods described in 032617, International Publication No. 2008/032616, International Publication No. 2008/129947, and the like.

Specific examples of the aniline derivative represented by the formula (1) include phenyldiphenylamine, phenyltriphenylamine, phenyltetraphenylamine, phenylpentaniline, tetraphenylamine (aniline tetramer), and octaaniline. (Aniline 8 polymer), hexadecylaniline (aniline 16 polymer), or those represented by the following formulae are not limited thereto.

Examples of the organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent on a silicon atom used as the charge-transporting varnish of the present invention include a dialkoxy group having a chlorine-containing monovalent hydrocarbon group as a substituent. Silanes and trialkoxysilanes, but trialkoxysilanes having a chlorine-containing monovalent hydrocarbon group as a substituent are preferred.

Examples of the chlorine-containing monovalent hydrocarbon group include a chlorinated alkyl group having 1 to 20 carbon atoms, a chlorinated alkenyl group having 2 to 20 carbon atoms, a chlorinated alkynyl group having 2 to 20 carbon atoms, and 6 to 20 carbon atoms. A chlorinated aryl group, etc., but preferably a chlorinated alkyl group having 1 to 20 carbon atoms, a chlorinated aryl group having 6 to 20 carbon atoms, a chlorinated alkyl group having 1 to 10 carbon atoms, and 6 to 10 carbon atoms A chloroaryl group is preferred.

Specific examples of the chlorinated alkyl group having 1 to 20 carbon atoms include the groups in which at least one hydrogen atom of the alkyl group having 1 to 20 carbon atoms is replaced with a chlorine atom.

More specific examples include chloromethyl, dichloromethyl, trichloromethyl, 1-chloroethyl, 1,1-dichloroethyl, 2-chloroethyl, and 2,2-dichloro Ethyl, 2,2,2-trichloroethyl, 1,1,2,2,2-pentachloroethyl, 3-chloropropyl, 3,3-dichloropropyl, 3,3,3- Trichloropropyl, 2,2,3,3,3-pentachloropropyl, 1,1,2,2,3,3,3-heptachloropropyl, etc.

Specific examples of the chlorinated alkenyl group having 2 to 20 carbon atoms include a group in which at least one hydrogen atom of the alkenyl group having 2 to 20 carbon atoms is replaced with a chlorine atom.

More specific examples include 1-chlorovinyl, 3-chloro-1-propenyl, and the like.

Specific examples of the chlorinated alkynyl group having 2 to 20 carbon atoms include the groups in which at least one hydrogen atom of the alkynyl group having 2 to 20 carbon atoms is replaced with a chlorine atom.

More specific examples include 1-chloroethynyl and 3-chloro-1-propynyl Wait.

Specific examples of the chlorinated aryl group having 6 to 20 carbon atoms include the group in which at least one hydrogen atom of the aryl group having 6 to 20 carbon atoms is replaced with a chlorine atom.

More specific examples include 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4,6-trichlorophenyl, perchlorophenyl, and 4-chloro-1-naphthalene And 4-chloro-2-naphthyl.

Examples of the organosilane compound that can be suitably used in the present invention include chloroalkyltrimethoxysilanes such as chloromethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, and 3-chloropropyltriethoxysilane. Alkoxysilane, 2-chlorophenyltrimethoxysilane, 3-chlorophenyltrimethoxysilane, 4-chlorophenyltrimethoxysilane, 2-chlorophenyltriethoxysilane, 3-chlorobenzene Chlorophenyltrialkoxysilanes such as triethoxysilane, 4-chlorophenyltriethoxysilane, etc. Among them, chlorophenyltrialkoxysilane is also preferred, and 4-chlorophenyltrisilane Alkoxysilanes are preferred, and 4-chlorophenyltrimethoxysilane is most preferred.

As long as the amount of the organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent does not adversely affect the contact angle of the obtained film or the characteristics of the organic EL element, that is, it is not particularly limited. The total mass of the impurities is usually about 0.1 to 50% by mass, preferably about 0.5 to 40% by mass, more preferably about 0.8 to 30% by mass, and even more preferably about 1 to 20% by mass.

The dopant used in the charge-transporting varnish of the present invention is not particularly limited as long as it is soluble in at least one solvent used in the varnish. Inorganic dopants and organic dopants can be used. Any quality.

Examples of the inorganic doping materials include inorganic acids such as hydrogen chloride, sulfuric acid, nitric acid, and phosphoric acid; aluminum (III) chloride (AlCl ₃ ), titanium (IV) tetrachloride (TiCl ₄ ), and tribromide Boron (BBr ₃ ), boron trifluoride ether complex (BF ₃ ‧OEt ₂ ), iron (III) chloride (FeCl ₃ ), copper (II) chloride (CuCl ₂ ), antimony pentachloride (V ) (SbCl ₅ ), antimony pentafluoride (V) (SbF ₅ ), arsenic pentafluoride (V) (AsF ₅ ), phosphorus pentafluoride (PF ₅ ), ginseng (4-bromophenyl) aluminum hexachloride Antimonate (TBPAH) and other metal halides; Cl ₂ , Br ₂ , I ₂ , ICl, ICl ₃ , IBr, IF ₄ and other halogens; heteropoly acids such as phosphomolybdic acid, phosphotungstic acid, etc.

Examples of the organic doping substance include benzenesulfonic acid, toluenesulfonic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalic acid, and p-dodecanoic acid. Benzenesulfonic acid, dihexylbenzenesulfonic acid, 2,5-dihexylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, 6,7-dibutyl-2-naphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, 3 -Dodecyl-2-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 4-hexyl-1-naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2-octyl-1-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 7- Hexyl-1-naphthalenesulfonic acid, 6-hexyl-2-naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, 2,7-dinonyl-4-naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, 2,7 -Dinonyl-4,5-naphthalenedisulfonic acid, 1,4-benzodioxane disulfonic acid compound described in International Publication No. 2005/000832, and arylsulfonic acid described in International Publication No. 2006/025342 Compounds, arylsulfonic compounds such as arylsulfonic acid compounds and polystyrenesulfonic acids described in International Publication No. 2009/096352; non-arylfluorene compounds such as 10-camphorsulfonic acid; 7,7,8,8- Tetracyanoquinone dimethane (TCNQ), Organic oxidants such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ).

These inorganic and organic dopant species can be used alone or in combination of two or more.

Among these doping materials, heteropolyacids are suitable. By using heteropolyacids as doping materials, it can be obtained not only from the sources of indium tin oxide (ITO), indium zinc oxide (IZO) A thin film which has a high hole accepting ability as a representative transparent electrode and exhibits a high hole transporting ability from a metal anode represented by aluminum, which is excellent in charge transportability.

Heteropolyacid means a structure having a heteroatom located at the center of a molecule represented by a chemical structure typically represented by a Keggin type represented by formula (B1) or a Dawson type represented by formula (B2), and is a vanadium (V) Oxygen-containing acids such as molybdenum (Mo), tungsten (W), etc. are polybasic acids formed by the condensation of isomeric polymeric acids with oxy-acids of different elements. Examples of the oxyacids of such dissimilar elements include oxyacids such as silicon (Si), phosphorus (P), and arsenic (As).

Specific examples of the heteropoly acid include phosphomolybdic acid, silomomolybdic acid, phosphotungstic acid, silototungstic acid, phosphotungstomolybdic acid, and the like. These may be used alone or in combination of two or more. In addition, the heteropoly acid used in the present invention can be obtained as a commercial product, and it can also be combined by a known method. to make.

In particular, when the doping substance is composed of one type of heteropoly acid alone, the one type of heteropoly acid is preferably phosphotungstic acid or phosphomolybdic acid, but it is preferably phosphotungstic acid. When the doping substance is composed of two or more kinds of heteropoly acids, one of the two or more kinds of heteropoly acids is preferably phosphotungstic acid or phosphomolybdic acid, but phosphotungstic acid is more preferable.

Moreover, under quantitative analysis such as elemental analysis of heteropoly acids, even if the number of elements is more or less than the structure shown in the general formula, it is only necessary to obtain it as a commercially available product or to synthesize it by a known synthesis method. Can be used in the present invention.

That is, for example, in general, phosphotungstic acid is represented by the chemical formula H ₃ (PW ₁₂ O ₄₀ ) ‧nH ₂ O, and phosphomolybdic acid is represented by the chemical formula H ₃ (PMo ₁₂ O ₄₀ ) ‧nH ₂ O, Under quantitative analysis, even if the amount of P (phosphorus), O (oxygen), W (tungsten) or Mo (molybdenum) in this formula is larger or smaller, as long as it is obtained as a commercially available product, Or those suitable for synthesis according to a known synthesis method can be used in the present invention. At this time, the mass of the heteropoly acid specified in the present invention does not refer to the mass of pure phosphotungstic acid (phosphotungstic acid content) in the composition or the commercially available product, but refers to the form and The full mass in a state that can be separated by a known synthesis method includes hydrated water or other impurities.

Moreover, an arylsulfonic acid compound can also be suitably used as a doping substance. In particular, an arylsulfonic acid compound represented by the formula (2) or (3) is preferred.

A ¹ represents O or S, but O is preferred.

A ² represents a naphthalene ring or an anthracene ring, but a naphthalene ring is preferred.

A ³ represents a 2- to 4-valent perfluorobiphenyl, p represents a combination number of A ¹ and A ³ and satisfies an integer of 2 ≦ p ≦ 4, A ³ is a divalent perfluorobiphenyl, and p is 2 is preferred.

q represents the number of sulfonic acid groups bound to A ² and is an integer satisfying 1 ≦ q ≦ 4, but 2 is the best.

A ⁴ to A ⁸ each independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, or a halogenated alkenyl group having 2 to 20 carbon atoms, A ⁴ At least 3 of ~ A ⁸ are each a halogen atom.

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

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

Other examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms include It is the same as the above, but a halogen atom is preferably a fluorine atom.

Among these, A ⁴ to A ⁸ are a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms, In addition, it is preferable that at least three of A ⁴ to A ⁸ are fluorine atoms, and a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, or 2 carbon atoms. ~ 5 fluorinated alkenyl groups, and at least 3 of A ⁴ ~ A ⁸ are preferably fluorine atoms, with hydrogen atom, fluorine atom, cyano group, perfluoroalkyl group having 1 to 5 carbon atoms or carbon number 1 It is more preferred that the perfluoroalkenyl group of ~ 5, and A ⁴ , A ⁵ and A ^{8 are} all fluorine atoms.

Moreover, a perfluoroalkyl group refers to a group in which all hydrogen atoms of an alkyl group are replaced with fluorine atoms, and a perfluoroalkenyl group refers to a group in which all hydrogen atoms of an alkenyl group are replaced with fluorine atoms.

r represents the number of sulfonic acid groups bound to the naphthalene ring, and is an integer satisfying 1 ≦ r ≦ 4, but 2 to 4 is preferred, and 2 is most preferred.

The molecular weight of the aryl sulfonic acid compound used as the doping substance is not particularly limited. When considering the solubility to the organic solvent at the same time as the charge transporting oligomer, it is preferably 2000 or less, more preferably It is 1500 or less.

Hereinafter, specific examples of a suitable arylsulfonic acid compound used as a doping substance in the present invention are exemplified, but are not limited thereto.

When the dopant substance is contained in the charge-transporting varnish of the present invention, the amount of dopant substance can be appropriately determined because it takes into consideration the type of dopant substance and the desired degree of charge-transporting property, so it cannot be specified in general. In other words, the mass ratio is in the range of 0.01 to 50 with respect to the charge transporting substance 1.

As the organic solvent used in the preparation of the charge-transporting varnish, a highly soluble solvent that can well dissolve the charge-transporting substance, the doping substance, and the organic silane compound can be used.

Examples of such a highly soluble solvent include cyclohexanone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, 1,3 -Organic solvents such as dimethyl-2-imidazolinone, diethylene glycol monomethyl ether, N, N-dimethylisobutyric acid ammonium amine, etc., but not limited thereto. These solvents can be used singly or as a mixture of two or more. The amount used can be 5 to 100% by mass based on the entire solvent used in the varnish.

In addition, the charge transporting substance, the doping substance, and the organosilane compound are preferably in a state of being completely dissolved or uniformly dispersed in any of the above-mentioned solvents, and more preferably completely dissolved.

Moreover, in the present invention, by making the varnish contain at least one kind having a viscosity of 10 to 200 mPa · s at 25 ° C, especially having a viscosity of 35 to 150 mPa · s, and a boiling point of 50 to 300 ° C under normal pressure (atmospheric pressure), In particular, a high-viscosity organic solvent at 150 to 250 ° C makes it easy to adjust the viscosity of the varnish. As a result, it becomes possible to prepare a varnish that imparts a high flatness film in accordance with the method of cloth used and which has good reproducibility.

Examples of the high-viscosity organic solvent include cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octanediol, diethylene glycol, dipropylene glycol, triethylene glycol, Tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, propylene glycol, hexanediol, and the like are not limited thereto. These solvents may be used alone or in combination of two or more.

In the present invention, with respect to the entire solvent used in the varnish, the addition ratio of the high-viscosity organic solvent is preferably in a range that does not precipitate solids. As long as the solid is not precipitated, the addition ratio is 5 to 90% by mass as good.

In addition, for the purpose of improving the wettability of the substrate, adjusting the surface tension of the solvent, adjusting the polarity, and adjusting the boiling point, etc., it can also be 1 to 90% by mass relative to the entire solvent used in the varnish, preferably 1 Mix with other solvents at a ratio of ~ 50% by mass.

Examples of such a solvent include propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol monoethyl ether. Acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diacetone alcohol, γ-butyrolactone , Ethyl lactate, n-hexyl acetate, etc., but not limited to these. These solvents can be used alone or in combination. More than one species is used.

The viscosity of the varnish of the present invention is appropriately set according to the thickness of the film to be produced or the solid content concentration, etc., and is usually 1 to 50 mPa · s at 25 ° C. The surface tension of the varnish of the present invention is appropriately set depending on the coating method to be used, and is usually 20 to 50 mN / m.

In addition, the solid content concentration of the charge-transporting varnish in the present invention is suitably set after taking into consideration the varnish viscosity and surface tension, or the thickness of the film to be produced, and is usually about 0.1 to 10.0% by mass. In the case of coatability, it is preferably about 0.5 to 5.0% by mass, and more preferably about 1.0 to 3.0% by mass. Moreover, solid content means a charge transporting substance and a dopant substance.

By applying the charge-transporting varnish described above to a substrate and firing, a charge-transporting film can be formed on the substrate.

The coating method of the varnish is not particularly limited, and examples thereof include a dipping method, a spin coating method, a transfer printing method, a roll coating method, a bristle coating method, an inkjet method, a spray method, and a slit coating method. For cloth method, it is better to adjust the viscosity and surface tension of the varnish according to the coating method.

In addition, when the varnish of the present invention is used, the firing environment is not particularly limited, and a thin film having a uniform film-forming surface and high charge transportability can be obtained not only in the atmospheric environment, but also in an inert gas such as nitrogen or in a vacuum.

The firing temperature is appropriately set within a range of about 100 to 260 ° C after considering the use of the obtained film, the degree of charge transportability imparted to the obtained film, the type of solvent or the boiling point, and the like. When the thin film is used as a hole injection layer of an organic EL element, it is preferably about 140 to 250 ° C, and more preferably about 145 to 240 ° C.

In addition, for firing, it is possible to apply a temperature change of more than two stages for the purpose of exhibiting a high uniform film-forming property or reacting it on a substrate. The heating system uses, for example, a hot plate or an oven. It can be performed using appropriate equipment.

The film thickness of the charge-transporting thin film is not particularly limited. When it is used as a hole injection layer in an organic EL device, it is preferably 5 to 200 nm. As a method for changing the film thickness, there are methods such as changing the solid content concentration in the varnish, or changing the amount of the solution on the substrate during coating.

The charge transporting film of the present invention described above has excellent charge transportability and flatness. In addition, toluene, stubs, chloroform, 3-phenoxytoluene, tetrahydronaphthalene, etc. contained in the varnish used when forming the hole transporting layer or the light emitting layer of the organic EL element on the film by a wet process. The organic solvent can be suitable for coating.

Therefore, the film obtained from the charge-transporting varnish of the present invention can be suitably used in an electronic device such as an organic EL element having a multilayer structure formed by a wet process.

An example of a method for manufacturing an OLED device having a hole injection layer composed of a film obtained from the charge-transporting varnish of the present invention is as follows.

The electrode substrate used is preferably cleaned in advance with a liquid such as a detergent, alcohol, pure water and the like, for example, the anode substrate is subjected to UV ozone treatment, oxygen-plasma treatment, etc. before use. Surface treatment is good. However, when the anode material contains an organic substance as a main component, the surface treatment may not be performed.

According to the method described above, the charge-transporting varnish of the present invention is coated on the anode substrate and fired to form a hole injection layer on the electrode. This is introduced into a vacuum evaporation device, and an OLED element is formed by vapor deposition in the order of a hole transporting layer, a light emitting layer, an electron transporting layer, an electron transporting layer / hole blocking layer, and a cathode metal. Moreover, if necessary, an electron blocking layer may be provided between the light emitting layer and the hole transporting layer.

Examples of the anode material include transparent electrodes represented by indium tin oxide (ITO) and indium zinc oxide (IZO), or metal anodes composed of a metal represented by aluminum or an alloy thereof, and the like. It is preferable to perform a flattening process. It is also possible to use a polythiophene derivative or a polyaniline derivative having a high charge-transporting property.

Examples of other metals constituting the metal anode include rhenium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, Cadmium, indium, thallium, lanthanum, cerium, praseodymium, neodymium, giant, thorium, thorium, thorium, thorium, thorium, ', thorium, thorium, thorium, thorium, thorium, tungsten, thallium, thallium, thallium, iridium, platinum, gold, Titanium, lead, bismuth, or these alloys are not limited to these.

Examples of the material for forming the hole transport layer include (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spiro dimers, N, N'-bis (naphthalene- 1-yl) -N, N'-bis (phenyl) -benzidine (α-NPD), N, N'-bis (naphthalene-2-yl) -N, N'-bis (phenyl) -bi Aniline, N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) -benzidine, N, N'-bis (3-methylphenyl) -N, N ' -Bis (phenyl) -9,9-cyclocyclobifluorene, N, N'-bis (naphthalene-1-yl) -N, N'-bis (phenyl) -9,9-cyclobifluorene, N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) -9,9-dimethyl-fluorene, N, N'-bis (naphthalene-1-yl)- N, N'-bis (phenyl) -9,9-dimethyl-fluorene, N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) -9,9 -Diphenyl-fluorene, N, N'-bis (naphthalene-1-yl) -N, N'-bis (phenyl) -9,9-diphenyl-fluorene, N, N'-bis (naphthalene -1-yl) -N, N'-bis (phenyl) -2,2'-dimethylbenzidine, 2,2 ', 7,7'-methyl (N, N-diphenylamino) -9,9-cyclocyclobifluorene, 9,9-bis [4- (N, N-bis-biphenyl-4-yl-amino) phenyl] -9H-fluorene, 9,9-bis [4 -(N, N-bis-naphthalen-2-yl-amino) phenyl] -9H-fluorene, 9,9-bis [4- (N-naphthalen-1-yl-N-phenylamino)- Phenyl] -9H-fluorene, 2,2 ', 7,7'-[[N-naphthyl (phenyl) -amino] -9,9-cyclobifluorene, N, N'-bis (phenanthrene -9-based ) -N, N'-bis (phenyl) -benzidine, 2,2'-bis [N, N-bis (biphenyl-4-yl) amino] -9,9-cyclobifluorene, 2 , 2'-bis (N, N-diphenylamino) -9,9-cyclobifluorene, di- [4- (N, N-bis (p-tolyl) amino) -phenyl] Cyclohexane, 2,2 ', 7,7'-tetrakis (N, N-bis (p-tolyl)) amino-9,9-cyclocyclobifluorene, N, N, N', N'- Tetra-naphthalen-2-yl-benzidine, N, N, N ', N'-tetra- (3-methylphenyl) -3,3'-dimethylbenzidine, N, N'-bis ( Naphthyl) -N, N'-bis (naphthyl-2-yl) -benzidine, N, N, N ', N'-tetrakis (naphthyl) -benzidine, N, N'-bis (naphthalene-2 -Yl) -N, N'-diphenylbenzidine-1,4-diamine, N ¹ , N ⁴ -diphenyl-N ¹ , N ⁴ -bis (m-tolyl) benzene-1,4 -Diamine, N ² , N ² , N ⁶ , N ⁶ -tetraphenylnaphthalene-2,6-diamine, ginseng (4- (quinolin-8-yl) phenyl) amine, 2,2'- Bis (3- (N, N-bis (p-tolyl) amino) phenyl) biphenyl, 4,4 ', 4 "-para [3-methylphenyl (phenyl) amino] triphenyl Triarylamines (m-MTDATA), 4,4 ', 4 "-reference [1-naphthyl (phenyl) amino] triphenylamine (1-TNATA), etc., 5,5"- Oligothiophenes and the like of bis- {4- [bis (4-methylphenyl) amino] phenyl} -2,2 ': 5', 2 "-bitrithiophene (BMA-3T) and the like.

Examples of the material for forming the light-emitting layer include ginseng (8-hydroxyquinoline) aluminum (III) (Alq ₃ ), bis (8-hydroxyquinoline) zinc (II) (Znq ₂ ), and bis (2-formaldehyde). -8-hydroxyquinoline) -4- (p-phenylphenolate) aluminum (III) (BAlq), 4,4'-bis (2,2-diphenylvinyl) biphenyl, 9,10 -Bis (naphthalene-2-yl) anthracene, 2-t-butyl-9,10-bis (naphthalene-2-yl) anthracene, 2,7-bis [9,9-bis (4-methylphenyl) ) -Fluoren-2-yl] -9,9-bis (4-methylphenyl) fluorene, 2-methyl-9,10-bis (naphthalene-2-yl) anthracene, 2- (9,9- (Cyclobicyclo-2-fluorene) -9,9-cyclobicyclofluorene, 2,7-bis (9,9-cyclobicyclofluoren-2-yl) -9,9-cyclobicyclofluorene, 2- [9,9-bis (4-methylphenyl) -fluoren-2-yl] -9,9-bis (4-methylphenyl) fluorene, 2,2'-difluorenyl-9,9- Rotary bisbifluorene, 1,3,5-ginsyl (fluoren-1-yl) benzene, 9,9-bis [4- (fluorenyl) phenyl] -9H-fluorene, 2,2'-bis (9, 10-diphenylanthracene), 2,7-difluorenyl-9,9-cyclocyclobifluorene, 1,4-bis (fluoren-1-yl) benzene, 1,3-bis (fluoren-1-yl) ) Benzene, 6,13-bis (biphenyl-4-yl) fused pentabenzene, 3,9-bis (naphthalene-2-yl) fluorene, 3,10-bis (naphthalene-2-yl) fluorene, ginseng [ 4- (fluorenyl) -phenyl] amine, 10,10'-bis (biphenyl-4-yl) -9,9'-bianthracene, N, N'-bis (naphthalene-1-yl) -N , N'-diphenyl- [1,1 ': 4', 1 ”: 4”, 1 ”'-Tetraphenyl] -4,4”'- Amine, 4,4'-bis [10- (naphthalene-1-yl) anthracene-9-yl] biphenyl, dibenzo {[f, f ']-4,4', 7,7'-tetrabenzene Group} diindeno [1,2,3-cd: 1 ', 2', 3'-lm] pyrene, 1- (7- (9,9'-bianthran-10-yl) -9,9- Dimethyl-9H-fluoren-2-yl) fluorene, 1- (7- (9,9'-bianthran-10-yl) -9,9-dihexyl-9H-fluoren-2-yl) fluorene, 1,3-bis (carbazole-9-yl) benzene, 1,3,5-gins (carbazole-9-yl) benzene, 4,4 ', 4 "-syn (carbazole-9-yl) tri Phenylamine, 4,4'-bis (carbazole-9-yl) biphenyl, 4,4'-bis (carbazole-9-yl) -2,2'-dimethylbiphenyl, 2,7 -Bis (carbazole-9-yl) -9,9-dimethylfluorene, 2,2 ', 7,7'-di (carbazole-9-yl) -9,9-cyclobifluorene, 2 , 7-bis (carbazole-9-yl) -9,9-bis (p-tolyl) fluorene, 9,9-bis [4- (carbazole-9-yl) -phenyl] fluorene, 2 ,, 7-bis (carbazol-9-yl) -9,9-cyclocyclobifluorene, 1,4-bis (triphenylsilyl) benzene, 1,3-bis (triphenylsilyl) benzene, bis (4-N, N-diethylamino-2-methylphenyl) -4-methylphenylmethane, 2,7-bis (carbazole-9-yl) -9,9-dioctyl Samarium, 4,4 "-bis (triphenylsilyl) -p-terphenyl, 4,4'-bis (triphenylsilyl) biphenyl, 9- (4-t-butylphenyl) -3,6-bis (triphenylsilyl) -9H-carbazole, 9- (4-t-butylphenyl) -3,6-bistrityl-9H-carbazole, 9- ( 4-t-ding Phenyl) -3,6-bis (9- (4-methoxyphenyl) -9H-fluoren-9-yl) -9H-carbazole, 2,6-bis (3- (9H-carbazole -9-yl) phenyl) pyridine, triphenyl (4- (9-phenyl-9H-fluoren-9-yl) phenyl) silane, 9,9-dimethyl-N, N-diphenyl -7- (4- (1-phenyl-1H-benzo [d] imidazol-2-yl) phenyl) -9H-fluoren-2-amine, 3,5-bis (3- (9H-carbazole -9-yl) phenyl) pyridine, 9,9-cyclobifluoren-2-yl-diphenyl-phosphine oxide, 9,9 '-(5- (triphenylsilyl) -1,3 -Phenylene) bis (9H-carbazole), 3- (2,7-bis (diphenylphosphonium) -9-phenyl-9H-fluorene-9-yl) -9-phenyl-9H -Carbazole, 4,4,8,8,12,12-hexa (p-tolyl) -4H-8H-12H-12C-azadibenzo [cd, mn] pyrene, 4,7-bis ( 9H-carbazole-9-yl) -1,10-morpholine, 2,2'-bis (4- (carbazole-9-yl) phenyl) biphenyl, 2,8-bis (diphenylphosphine) Fluorenyl) dibenzo [b, d] thiophene, bis (2-methylphenyl) diphenylsilane, bis [3,5-bis (9H-carbazole-9-yl) phenyl] diphenyl Silane, 3,6-bis (carbazole-9-yl) -9- (2-ethyl-hexyl) -9H-carbazole, 3- (diphenylphosphonium) -9- (4- (di Phenylphosphonium) phenyl) -9H-carbazole, 3,6-bis [(3,5-diphenyl) phenyl] -9-phenylcarbazole, etc. Co-evaporated together to form hair Floor.

Examples of the light-emitting doping include 3- (2-benzothiazolyl) -7- (diethylamino) coumarin, 2,3,6,7-tetrahydro-1,1,7 , 7-tetramethyl-1H, 5H, 11H-10- (2-benzothiazolyl) quinazinyl [9,9a, 1gh] coumarin, quinacridone, N, N'-dimethyl -Quinacridone, ginseng (2-phenylpyridine) iridium (III) (Ir (ppy) ₃ ), bis (2-phenylpyridine) (ethylpyridinate) iridium (III) (Ir (ppy) ₂ (acac)), reference [2- (p-tolyl) pyridine] iridium (III) (Ir (mppy) ₃ ), 9,10-bis [N, N-bis (p-tolyl) amino] Anthracene, 9,10-bis [phenyl (m-tolyl) amino] anthracene, bis [2- (2-hydroxyphenyl) benzothiazolyl] zinc (II), N ¹⁰ , N ¹⁰ , N ^{10 '} , N ^10' -tetra (p-tolyl) -9,9'-bianthrene-10,10'-diamine, N ¹⁰ , N ¹⁰ , N ^{10 '} , N ^10' -tetraphenyl-9, 9'-Bianthracene-10,10'-diamine, N ¹⁰ , N ^{10 '} -Diphenyl-N ¹⁰ , N ^10' -Dinaphthyl-9,9'-Bianthan-10,10'-di Amine, 4,4'-bis (9-ethyl-3-carbazole vinylidene) -1,1'-biphenyl, fluorene, 2,5,8,11-tetra-t-butylfluorene, 1 , 4-bis [2- (3-N-ethylcarbazole) vinyl] benzene, 4,4'-bis [4- (di-p-tolylamino) styryl] biphenyl, 4- (Di-p-tolylamino) -4 '-[(di-p-tolylamino) styryl] fluorene, bis [3,5- Difluoro-2- (2-pyridyl) phenyl- (2-carboxypyridyl)] iridium (III), 4,4'-bis [4- (diphenylamino) styryl] biphenyl, Bis (2,4-difluorophenylpyridyl) bis (1-pyrazolyl) borate iridium (III), N, N'-bis (naphthalene-2-yl) -N, N'-bis (phenyl) ) -Gins (9,9-dimethylarylene), 2,7-bis {2- [phenyl (m-tolyl) amino] -9,9-dimethyl-fluoren-7-yl } -9,9-dimethyl-fluorene, N- (4-((E) -2- (6 ((E) -4- (diphenylamino) styryl) naphthalene-2-yl) (Vinyl) phenyl) -N-phenylaniline, fac-iridium (III), (1-phenyl-3-methylbenzimidazoline-2-ylidene-C, C ^{2 '} ), mer-iridium (III) Preference (1-phenyl-3-methylbenzimidazoline-2-ylidene-C, C ^{2 '} ), 2,7-bis [4- (diphenylamino) styryl] -9,9-cyclobifluorene, 6-methyl-2- (4- (9- (4- (6-methylbenzo [d] thiazol-2-yl) phenyl) anthracene-10-yl ) Phenyl) benzo [d] thiazole, 1,4-bis [4- (N, N-diphenyl) amino] styrylbenzene, 1,4-bis (4- (9H-carbazole- 9-yl) styryl) benzene, (E) -6- (4- (diphenylamino) styryl) -N, N-diphenylnaphthalene-2-amine, bis (2,4- Difluorophenylpyridine) (5- (pyridin-2-yl) -1H-tetrazolyl) iridium (III), bis (3-trifluoromethyl-5- (2-pyridyl) pyrazole) ( (2,4-difluoro Phenyl) diphenylphosphite) iridium (III), bis (3-trifluoromethyl-5- (2-pyridyl) pyrazolyl) (benzyldiphenylphosphite) iridium (III), bis ( 1- (2,4-difluorobenzyl) -3-methylbenzimidazolium) (3- (trifluoromethyl) -5- (2-pyridyl) -1,2,4-triazole radical ) Iridium (III), bis (3-trifluoromethyl-5- (2-pyridyl) pyrazolium) (4 ', 6'-difluorophenylpyridyl) iridium (III), bis (4' , 6'-difluorophenylpyridyl) (3,5-bis (trifluoromethyl) -2- (2'-pyridyl) pyrazolyl) iridium (III), bis (4 ', 6'- Difluorophenylpyridyl) (3- (trifluoromethyl) -5- (2-pyridyl) -1,2,4-triazolyl) iridium (III), (Z) -6-podyl- N- (6-podylquinoline-2 (1H) -subunit) quinoline-2-amine-BF ₂ , (E) -2- (2- (4- (dimethylamino) styryl group ) -6-methyl-4H-pyran-4-ylidene) malononitrile, 4- (dicyanomethylene) -2-methyl-6-pyrrolidin-9-alkenyl-4H- Pyran, 4- (dicyanomethylene) -2-methyl-6- (1,1,7,7-tetramethylpyrrolidine-9-alkenyl) -4H-pyran, 4- (Dicyanomethylene) -2-t-butyl-6- (1,1,7,7-tetramethyljupyridin-4-yl-vinyl) -4H-pyran Benzamidinemethane) phenanthroline (III), 5,6,11,12-tetraphenyl fused tetrabenzene, bis (2-benzo [b] thien-2-yl-pyridine) (acetamidine Pyruvate) iridium (III), ginseng (1-phenylisoquinoline) iridium (III), bis (1-phenylisoquinoline) (acetamidopyruvate) iridium (III), bis [1- ( 9,9-dimethyl-9H-fluoren-2-yl) -isoquinoline] (ethylpyruvate) iridium (III), bis [2- (9,9-dimethyl-9H-fluorene- 2-yl) quinoline] (acetamidopyruvate) iridium (III), ginseng [4,4'-di-t-butyl- (2,2 ')-bipyridine] ruthenium (III) ‧bis ( Hexafluorophosphate), ginseng (2-phenylquinoline) iridium (III), bis (2-phenylquinoline) (acetamidopyruvate) iridium (III), 2,8-di-t-butyl -5,11-bis (4-t-butylphenyl) -6,12-diphenyl fused tetrabenzene, bis (2-phenylbenzothiazolyl) (ethylpyruvate) iridium (III ), 5,10,15,20-tetraphenyltetrabenzoporphyrin platinum, fluorene (II) bis (3-trifluoromethyl-5- (2-pyridine) -pyrazolyl) dimethylphenyl Phosphine, osmium (II) bis (3- (trifluoromethyl) -5- (4-t-butylpyridyl) -1,2,4-triazolyl) diphenylmethylphosphine, osmium (II) ) Bis (3- (trifluoromethyl) -5- (2-pyridyl) -1,2,4-triazole) dimethylphenylphosphine, fluorene (II) bis (3- (trifluoromethyl) ) -5- (4-t-butylpyridyl) -1,2,4-triazolyl) dimethylphenylphosphine, bis [2- (4-n-hexylphenyl) quinoline] (ethyl Fluorenylpyruvate) iridium (III), reference [2- (4-n- Phenyl) quinoline] iridium (III), reference [2-phenyl-4-methylquinoline] iridium (III), bis (2-phenylquinoline) (2- (3-methylphenyl) ) Pyridinium) iridium (III), bis (2- (9,9-diethyl-fluoren-2-yl) -1-phenyl-1H-benzo [d] imidazolium) (ethylpyridinylpyruvate) ) Iridium (III), bis (2-phenylpyridine) (3- (pyridin-2-yl) -2H-chromene-2-root) iridium (III), bis (2-phenylquinoline) (2 , 2,6,6-tetramethylheptane-3,5-acid di) iridium (III), bis (phenylisoquinoline) (2,2,6,6-tetramethylheptane-3 , 5-diacid) iridium (III), iridium (III) bis (4-phenylthieno [3,2-c] pyridyl-N, C ^{2 '} ) acetamidopyruvate, (E) -2 -(2-t-butyl-6- (2- (2,6,6-trimethyl-2,4,5,6-tetrahydro-1H-pyrrolo [3,2,1-ij] quine 8-yl) vinyl) -4H-pyran-4-ylidene) malononitrile, bis (3-trifluoromethyl-5- (1-isoquinolinyl) pyrazolyl) (methyl Diphenylphosphine) ruthenium, bis [(4-n-hexylphenyl) isoquinoline] (acetamidopyruvate) iridium (III), platinum (II) octaethylporphine, bis (2-methyl Dibenzo [f, h] quinoxaline) (ethylpyruvate) iridium (III), [[4-n-hexylphenyl) oxyquinoline] iridium (III), and the like.

Examples of the material forming the electron transporting layer / hole blocking layer include 8-hydroxyhydroxyquinoline-lithium, 2,2 ', 2 "-(1,3,5-petroleum tolyl) -ginseng (1 -Phenyl-1-H-benzimidazole), 2- (4-biphenyl) 5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,9-di Methyl-4,7-diphenyl-1,10-morpholine, 4,7-diphenyl-1,10-phenoline, bis (2-methyl-8-hydroxyquinoline) -4- ( Phenylphenolate) aluminum, 1,3-bis [2- (2,2'-bipyridin-6-yl) -1,3,4-oxadiazo-5-yl] benzene, 6,6 '-Bis [5- (biphenyl-4-yl) -1,3,4-oxadiazo-2-yl] -2,2'-bipyridine, 3- (4-biphenyl) -4 -Phenyl-5-t-butylphenyl-1,2,4-triazole, 4- (naphthalene-1-yl) -3,5-diphenyl-4H-1,2,4-triazole 2,2,9-bis (naphthalene-2-yl) -4,7-diphenyl-1,10-morphine Phthaloline, 2,7-bis [2- (2,2'-bipyridin-6-yl) -1,3,4-oxadiazo-5-yl] -9,9-dimethylfluorene, 1,3-bis [2- (4-t-butylphenyl) -1,3,4-oxodiazo-5-yl] benzene, ginseng (2,4,6-trimethyl-3 -(Pyridin-3-yl) phenyl) borane, 1-methyl-2- (4- (naphth-2-yl) phenyl) -1H-imidazole [4,5f] [1,10] morpholine , 2- (naphthalene-2-yl) -4,7-diphenyl-1,10-morpholine, phenyl-diamidinophosphine oxide, 3,3 ', 5,5'-tetra [(m -Pyridyl) -phenyl-3-yl] biphenyl, 1,3,5-gins [(3-pyridyl) -phenyl-3-yl] benzene, 4,4'-bis (4,6-diphenyl -1,3,5-triazin-2-yl) biphenyl, 1,3-bis [3,5-bis (pyridin-3-yl) phenyl] benzene, bis (10-hydroxybenzo [h ] Quinoline) beryllium, diphenylbis (4- (pyridin-3-yl) phenyl) silane, 3,5-bis (fluoren-1-yl) pyridine, and the like.

Examples of the material for forming the electron injection layer include lithium oxide (Li ₂ O), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), lithium fluoride (LiF), sodium fluoride (NaF), and fluorine Magnesium (MgF ₂ ), cesium fluoride (CsF), strontium fluoride (SrF ₂ ), molybdenum trioxide (MoO ₃ ), aluminum, Li (acac), lithium acetate, lithium benzoate, and the like.

Examples of the cathode material include aluminum, magnesium-silver alloy, aluminum-lithium alloy, lithium, sodium, potassium, and cesium.

Examples of the material forming the electron blocking layer include ginseng (phenylpyrazole) iridium.

The manufacturing method of the PLED element using the charge-transporting varnish of the present invention is not particularly limited, and examples thereof include the following methods.

In the above-mentioned OLED device manufacturing, instead of performing a vacuum evaporation operation of a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer, By forming in the order of the hole-transporting polymer layer and the light-emitting polymer layer, a PLED element having a charge-transporting film formed of the charge-transporting varnish of the present invention can be produced.

Specifically, the charge-transporting varnish of the present invention is coated on the anode substrate, and the hole injection layer is formed by the above method, and the hole-transporting polymer layer and the light-emitting polymer layer are sequentially formed thereon. It was formed, and then the cathode was evaporated to make a PLED element.

The cathode and anode materials used can be the same as those used in the production of the above OLED elements, and can be subjected to the same cleaning treatment and surface treatment.

Examples of the formation method of the hole-transporting polymer layer and the light-emitting polymer layer include, for example, adding a hole-transporting polymer material or a light-emitting polymer material, or a material to which a dopant is added, to a solvent It is a method of dissolving or uniformly dispersing, and coating on a hole injection layer or a hole transporting polymer layer, and then firing them to form a film.

Examples of hole-transporting polymer materials include poly [(9,9-dihexylfluorene-2,7-diyl) -co- (N, N'-bis {p-butylphenyl}- 1,4-diaminophenylphenyl)], poly [(9,9-dioctylfluorene-2,7-diyl) -co- (N, N'-bis {p-butylphenyl}- 1,1'-biphenyl-4,4-diamine)], poly [(9,9-bis {1'-pentene-5'-yl} fluorene-2,7-diyl) -co -(N, N'-bis {p-butylphenyl} -1,4-diaminophenylene)], poly [N, N'-bis (4- Butylphenyl) -N, N'-bis (phenyl) -benzidine], poly [(9,9-bisdioctylfluorene-2,7-diyl) -co- (4,4'- (N- (p-butylphenyl)) diphenylamine)] and the like.

Examples of the light-emitting polymer material include polyfluorene derivatives such as poly (9,9-dialkylfluorene) (PDAF), and poly (2-methoxy-5- (2'-ethylhexyloxy). (1,4-phenylene vinylene) (MEH-PPV) and other polyphenylene vinylene derivatives, poly (3-alkylthiophene) (PAT) and other polythiophene derivatives, polyvinyl carbazole (PVCz), etc.

Examples of the solvent include toluene, stubble, chloroform, 3-phenoxytoluene, and tetrahydronaphthalene. Examples of the dissolving or uniform dispersion method include methods such as stirring, heating and stirring, and ultrasonic dispersion.

The coating method is not particularly limited, and examples thereof include an inkjet method, a spray method, a dipping method, a spin coating method, a transfer printing method, a roll coating method, and a bristle coating method. In addition, the coating is preferably performed under an inert gas such as nitrogen or argon.

Examples of the firing method include a method of heating in an oven or a hot plate under an inert gas or in a vacuum.

[Example]

Hereinafter, the present invention will be described more specifically with examples and comparative examples, but the present invention is not limited by the following examples. Moreover, the devices used are as shown below.

(1) Substrate cleaning: Substrate cleaning device made by Changzhou Industry Co., Ltd. (decompression plasma system)

(2) Coating of varnish: Spincoater MS-A100 made by Mikasa

(3) Film thickness measurement: Fine shape measurement made by Kosaka Laboratory Surcoder ET-4000

(4) Contact angle measurement: Contact angle meter made by Kyowa Interface Chemistry Co., Ltd.

(5) Production of components: Multi-function evaporation deposition system C-E2L1G1-N made by Changzhou Industry Co., Ltd.

(6) Measurement of EL element brightness, etc .: (with) Tech World I-V-L measurement system

[1] Modulation of charge-transporting varnish [Example 1]

Under a nitrogen environment, 0.062 g of the aniline derivative represented by the formula [1] synthesized according to the method described in International Publication No. 2013/084664 and 0.309 g of phosphotungstic acid (manufactured by Japan New Metals Corporation) were dissolved in 1 1,3-dimethyl-2-imidazolinone (hereinafter abbreviated as DMI) in 4.8 g. To the obtained solution, 5.4 g of 2,3-butanediol (hereinafter abbreviated as 2,3-BD) and 1.8 g of ethyl diethylene glycol acetate (hereinafter abbreviated as EDGAc) were added and stirred. 0.011 g of 4-chlorophenyltrimethoxysilane was added to the obtained solution, and then stirred to prepare a charge-transporting varnish (solid content: 3.0% by mass).

[Comparative Example 1-1]

Under a nitrogen environment, 0.062 g of the aniline derivative represented by the formula [1] and 0.309 g of phosphotungstic acid (manufactured by Nippon Shinmetals Co., Ltd.) were dissolved in 4.8 g of DMI. To the obtained solution, 2,3-BD5.4 g and EDGAc 1.8 g were added and stirred to prepare a charge-transporting varnish (solid content: 3.0% by mass).

[Comparative Example 1-2]

A charge-transporting varnish (solid content: 3.0% by mass) was prepared in the same manner as in Example 1 except that 0.011 g of 4-chlorophenyltrimethoxysilane was replaced with 0.011 g of ethyltrimethoxysilane.

[Comparative Example 1-3]

Except substituting 0.011 g of 4-chlorophenyltrimethoxysilane for 0.011 g of trimethoxy (3,3,3-trifluoropropyl) silane, the same procedure as in Example 1 was performed to prepare a charge-transporting varnish. (3.0 mass% solid content).

[Comparative Example 1-4]

A charge transporting varnish (solid content: 3.0% by mass) was prepared in the same manner as in Example 1 except that 0.011 g of 4-chlorophenyltrimethoxysilane was replaced with 0.011 g of trimethoxy (phenyl) silane. .

[Comparative Example 1-5]

Except replacing 0.011 g of 4-chlorophenyltrimethoxysilane with triethoxy Except for 0.011 g of perfluoro (perfluorophenyl) silane, a charge transporting varnish (solid content: 3.0% by mass) was prepared in the same manner as in Example 1.

For the charge-transporting varnishes prepared in Example 1 and Comparative Examples 1-1 to 1-5, the contact angle was measured by the following method.

Each charge-transporting varnish was formed into a film on an indium tin oxide (ITO) substrate by spin coating, and dried on a hot plate at 80 ° C. for 1 minute in the air, and heated and fired at 230 ° C. for 15 minutes. And made into a thin film. For the obtained films, the contact angles of 3-phenoxytoluene and tetralin were measured. The results are shown in Table 1.

When the contact angle of the solvent used for the upper layer material is 10 ° or more, the upper layer material is repelled during lamination, and a uniform film may not be obtained. As shown in Table 1, the contact angle of the solvent on the film made from the charge-transporting varnish of Example 1 to which 4-chlorophenyltrimethoxysilane was added as an organic silane compound having a chlorine-containing monovalent hydrocarbon group, and No organic added The contact angle of the solvent on the film produced by the charge-transporting varnish of Comparative Example 1-1 of the silane compound was not different, that is, the added chlorine-containing organic silane compound did not affect the wettability of the upper layer. In addition, since the contact angle is 3 ° or less, it does not cause repulsion during lamination, and the upper layer has good coatability, and it is expected that the upper layer material will form a uniform film.

[2] Two-layer components

The substrate used in the evaluation of the electrical characteristics was a glass substrate (hereinafter referred to as an ITO substrate) having a thickness of 150 nm and a thickness of 25 nm × 25 mm × 0.7 t which was patterned on the surface. The ITO substrate is used after removing impurities on the surface using an O ₂ plasma cleaning device (150W, 30 seconds).

[Example 2]

The varnish obtained in Example 1 was applied to an ITO substrate using a spin coater, dried at 80 ° C for 1 minute, and fired at 230 ° C for 15 minutes in an atmospheric environment to form a uniform film of 30 nm on the ITO substrate (Hole injection layer). Using an evaporation apparatus (vacuum degree 1.0 × 10 ^-5 Pa), N, N'-bis (1-naphthyl) -N, N'-diphenylbenzidine (α-NPD) was sequentially laminated thereon. And aluminum thin film to obtain a two-layer element. The film thicknesses were 30 nm and 100 nm, respectively, and vapor deposition was performed under the condition that the vapor deposition rate was 0.2 nm / second.

In addition, in order to prevent the characteristics from being deteriorated due to the effects of oxygen and water in the air, the two-layer element is sealed with a sealing substrate, and then its characteristics are evaluated. Sealing is performed in the following order.

In a nitrogen environment with an oxygen concentration of 2 ppm or less and a dew point of -85 ° C or less, the device was housed between sealing substrates, and the sealing substrates were bonded together with a bonding material (manufactured by MORESCO, Moresco Moisture cut WB90US (P)). At this time, a water-capturing agent (manufactured by Dynac, HD-071010W-40) was stored in the sealing substrate together with the device. The bonded sealing substrate was irradiated with UV light (wavelength 365 nm, irradiation amount 6,000 mJ / cm ² ), and then annealed at 80 ° C. for 1 hour to harden the adhesive material.

[Comparative Examples 2-1 to 2-5]

Except that the varnish obtained in Example 1 was used instead of the varnish obtained in Comparative Examples 1-1 to 1-5, a two-layer element was produced by the same method as in Example 2.

For each manufactured two-layer element, the current density at a driving voltage of 3V was measured. The results are shown in Table 2.

As shown in Table 2, it can be seen that when the varnish (Comparative Example 1-1) was never added with an organic silane compound, The film made of the varnish of the organic silane compound (Comparative Examples 1-2, 1-4), and the film made from the varnish of Example 1 has excellent charge transportability.

In addition, it was found that the film has the same level of charge transportability as that of a film made of a varnish (Comparative Examples 1-3, 1-5) containing a fluorine-containing organic silane compound.

[3] Manufacturing and characteristic evaluation of organic EL elements [Example 3]

Using the varnish obtained in Example 1, the same method as in Example 2 was used to form a 30 nm uniform thin film on the ITO substrate.

Next, on a thin-film ITO substrate, N, N'-bis (1-naphthyl) -N, N'-diphenylbenzidine was laminated using an evaporation apparatus (vacuity degree 1.0 × 10 ^-5 Pa). (α-NPD) 30 nm. Next, CBP and Ir (PPy) ₃ were co-evaporated. In the co-evaporation system, the vapor deposition rate is controlled so that the concentration of Ir (PPy) ₃ becomes 6%, and 40 nm is laminated. Next, thin films of BAlq, lithium fluoride, and aluminum were sequentially laminated to obtain an organic EL device. At this time, the deposition rates of BAlq and aluminum were 0.2 nm / second and the deposition rates of lithium fluoride were 0.02 nm / second. The film thicknesses were 20 nm, 0.5 nm, and 100 nm, respectively.

The organic EL element was sealed by a sealing substrate in the same manner as in Example 2.

[Comparative Example 3-1]

An organic EL device was produced in the same manner as in Example 3, except that the varnish obtained in Comparative Example 1-1 was used instead of the varnish obtained in Example 1-1.

For each manufactured element, the brightness, current density, and current efficiency at a driving voltage of 10 V were measured. The results are shown in Table 3.

As shown in Table 3, when compared with the element of Comparative Example 3-1, it was found that the luminance of the element of Example 3 was higher, and other element characteristics were also maintained.

As can be understood from the results of Tables 1 to 3, the coatability of the upper layer can be maintained only when the charge-transporting varnish of the present invention containing an organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent is used. And achieve good brightness characteristics.

Claims (10)

A charge-transporting varnish comprising a charge-transporting substance, a doping substance, an organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent, and an organic solvent. The charge-transporting varnish according to claim 1, wherein the organic silane compound having a chlorine-containing monovalent hydrocarbon group as a substituent is a trialkoxysilane compound substituted with a chlorine-containing monovalent hydrocarbon group. The charge-transporting varnish according to claim 1 or 2, wherein the aforementioned chlorine-containing monovalent hydrocarbon group is at least one selected from a chlorinated alkyl group having 1 to 20 carbon atoms and a chlorinated aryl group having 6 to 20 carbon atoms. The charge-transporting varnish according to claim 1 or 2, wherein the organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent is chlorophenyltrialkoxysilane. The charge-transporting varnish according to claim 1 or 2, wherein the aforementioned doping substance is a heteropoly acid. A charge-transporting film produced by using the charge-transporting varnish according to any one of claims 1 to 5. An electronic device having a charge-transporting film as claimed in claim 6. An organic electroluminescence device having a charge-transporting film as claimed in claim 6. The organic electroluminescence device according to claim 8, wherein the charge transporting film is a hole injection layer or a hole transport layer. A method for manufacturing a charge-transporting film, which is characterized in that the charge-transporting varnish according to any one of claims 1 to 5 is coated on a substrate and a solvent is evaporated.