KR102388046B1 - Charge-transporting varnish - Google Patents

Abstract

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

Description

Charge-transporting varnish {CHARGE-TRANSPORTING VARNISH}

The present invention relates to charge transporting varnishes.

BACKGROUND ART Organic electroluminescence (EL) devices are expected to be put to practical use in fields such as displays and lighting, and various developments regarding materials and device structures have been made for the purpose of low voltage driving, high luminance, long lifespan, and the like.

In an organic EL device, a plurality of functional thin films are used, and one of them, the hole injection layer, is responsible for the transfer of charges between the anode and the hole transport layer or the light emitting layer, which is an important function to achieve low voltage driving and high luminance of the organic EL device. carry out

A method of forming the hole injection layer is roughly divided into a dry process represented by a vapor deposition method and a wet process represented by a spin coating method. Comparing these processes, the wet process can efficiently produce a thin film with high flatness over a large area, so in particular in the field of display, the wet process is not only used for the hole injection layer but also for the formation of the upper layers such as the hole transport layer and the light emitting layer. It is often used (refer to Patent Document 1).

Under these 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). However, as for the wet process material for the hole injection layer, improvement is still required. .

In particular, since it can contribute to the luminance characteristics of an organic EL device, higher uniformity is required not only for the hole injection layer but also for the hole transport layer (see Patent Document 8). There is a demand for a material capable of realizing excellent applicability of the hole transport layer and the light emitting layer formed by the wet process thereon.

Japanese Patent Laid-Open No. 2008-78181 International Publication No. 2006/025342 International Publication No. 2008/032616 International Publication No. 2008/129947 International Publication No. 2010/041701 International Publication No. 2010/058777 International Publication No. 2013/042623 Japanese Patent Laid-Open No. 2008-27646

The present invention has been made in consideration of the above circumstances, and a charge-transporting varnish capable of supplying a thin film exhibiting excellent luminance characteristics when applied to an organic EL device, having high flatness and high charge transporting properties, and excellent coatability of the upper layer material. aims to provide

The inventors of the present invention, as a result of repeated intensive studies to achieve the above object, use a charge-transporting varnish comprising a charge-transporting material, a dopant material, and an organosilane compound containing a chlorine atom, thereby improving flatness and charge-transporting properties. The present invention was completed by discovering that a thin film excellent in the applicability of the upper layer material could be produced, and that when the thin film was applied to an organic EL device, good luminance characteristics and the like could be realized.

In addition, Patent Documents 3 and 4 disclose a thin film obtained from a charge-transporting varnish comprising an oligoaniline derivative, an electron-accepting or hole-accepting dopant substance, a silane compound, and an organic solvent, and an organic EL device comprising the same. The silane compound used in or the charge-transporting varnish containing the same is not specifically disclosed, and there is no description teaching or suggesting that the thin film obtained from the varnish is excellent in the applicability of the upper layer material applied thereon.

That is, the present invention is

1. A charge-transporting varnish comprising a charge-transporting substance, a dopant substance, an organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent, and an organic solvent;

2. The charge-transporting varnish of 1 wherein the organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent is a chlorine-containing monovalent hydrocarbon group-substituted trialkoxysilane compound;

3. A charge-transporting varnish of 1 or 2 in which the chlorine-containing monovalent hydrocarbon group is at least one selected from an alkyl chloride group having 1 to 20 carbon atoms and an aryl chloride group having 6 to 20 carbon atoms;

4. The charge-transporting varnish according to any one of 1 to 3, wherein the organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent is chlorophenyltrialkoxysilane;

5. The charge-transporting varnish of any one of 1 to 4, wherein the dopant material is a heteropolyacid;

6. A charge-transporting thin film produced using the charge-transporting varnish of any one of 1 to 5;

7. An electronic device having the charge-transporting thin film of 6;

8. An organic electroluminescent device having the charge-transporting thin film of 6;

9. The organic electroluminescence device of 8, wherein the charge-transporting thin film is a hole injection layer or a hole transport layer;

10. A method for producing a charge-transporting thin film, comprising applying the charge-transporting varnish of any one of 1 to 5 on a substrate and evaporating the solvent

provides

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 realizing good luminance characteristics is obtained.

In addition, although the thin film obtained from the charge-transporting varnish of the present invention contains a chlorine atom-containing monovalent hydrocarbon group derived from a silane compound, the contact angle of the solvent used for the upper layer material on the surface thereof is obtained without adding a silane compound. There is no difference with the thin film.

In addition, the charge-transporting varnish of the present invention can produce a thin film excellent in charge-transporting property with good reproducibility even when various wet processes capable of forming a film on a large area, such as spin coating or slit coating, are used. It can sufficiently respond to progress in

In addition, the thin film obtained from the charge-transporting varnish of the present invention can also be used as an antistatic film or an anode buffer layer of an organic thin film solar cell.

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

The charge-transporting varnish according to the present invention contains a charge-transporting material, a dopant material, an organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent, and an organic solvent.

Here, charge-transporting property is synonymous with electroconductivity, and hole-transporting property is synonymous with it. The charge-transporting material may have charge-transporting properties by itself, or may have charge-transporting properties when used together with a dopant material (electron-accepting material). The charge-transporting varnish may have a charge-transporting property in itself, and the solid film obtained by it may have a charge-transporting property.

The charge-transporting material used in the present invention is not particularly limited as long as it has charge-transporting properties. For example, charge-transporting monomers, charge-transporting oligomers or polymers used in the field of organic EL devices, etc. can be suitably used, Since a charge-transporting varnish which supplies a charge-transporting thin film with high flatness can be prepared with good reproducibility, a charge-transporting oligomer is preferable.

Specific examples of the charge-transporting oligomer include aniline derivatives (arylamine derivatives) such as oligoaniline derivatives, N,N'-diarylbenzidine derivatives, N,N,N',N'-tetraarylbenzidine derivatives, oligothiophene derivatives, and thiophene derivatives. and various hole-transporting substances such as thiophene derivatives such as enothiophene derivatives and thienobenzothiophene derivatives, and pyrrole derivatives such as oligopyrrole derivatives. Among them, arylamine derivatives and thiophene derivatives are preferred, An arylamine derivative is more preferable.

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

The molecular weight is more preferably 300 or more, more preferably 400 or more, from the viewpoint of obtaining a thin film excellent in higher charge transport properties with good reproducibility, and from the viewpoint of preparing a uniform varnish that supplies a thin film with high flatness with good reproducibility, 8,000 or less is preferable, 7,000 or less are more preferable, 6,000 or less are still more preferable, and 5,000 or less are still more preferable.

In addition, from the viewpoint of preventing the charge-transporting substance from being separated when thinned, the charge-transporting substance such as a charge-transporting oligomer preferably has no molecular weight distribution (dispersity is 1) (that is, it is preferably a single molecular weight).

Although the thing represented by Formula (1) is mentioned as a specific example of an aniline derivative, It is not limited to this.

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, -NY ¹ - indicates

Y ¹ is each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ , an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, or Z ² which may be substituted , 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 linear, branched or cyclic, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s- a C1-C20 linear or branched alkyl group, such as a butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group; Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, bicyclobutyl group, bicyclopentyl group, bicyclohexyl group, bicyclohep and a cyclic alkyl group having 3 to 20 carbon atoms such as a tyl group, a bicyclooctyl group, a bicyclononyl group and a bicyclodecyl group.

Specific examples of the alkenyl group having 2 to 20 carbon atoms include an ethenyl group, n-1-propenyl group, n-2-propenyl group, 1-methylethenyl group, n-1-butenyl group, n-2-butenyl group, n-3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl-1-propenyl group, 1-methyl-2- A propenyl group, n-1-pentenyl group, n-1-decenyl group, n-1-eicosenyl group, etc. are mentioned.

Specific examples of the alkynyl group having 2 to 20 carbon atoms include ethynyl group, n-1-propynyl group, n-2-propynyl group, n-1-butynyl group, n-2-butynyl group, n-3-butynyl group, 1-methyl-2-propynyl group, n-1-pentinyl group, n-2-pentynyl group, n-3-pentinyl group, n-4-pentynyl group, 1-methyl-n-butynyl group, 2-methyl -n-butynyl group, 3-methyl-n-butynyl group, 1,1-dimethyl-n-propynyl group, n-1-hexynyl group, n-1-decynyl group, n-1-pentadecinyl group, n-1-eicosinyl group, etc. are mentioned.

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

Specific examples of the heteroaryl group having 2 to 20 carbon atoms include 2-thienyl group, 3-thienyl group, 2-furanyl group, 3-furanyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group , 3-isoxazolyl group, 4-isoxazolyl group, 5-isoxazolyl group, 2-thiazolyl group, 4-thiazolyl group, 5-thiazolyl group, 3-isothiazolyl group, 4-iso A thiazolyl group, 5-isothiazolyl group, 2-imidazolyl group, 4-imidazolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group etc. are mentioned.

R ⁷ and R ⁸ may be each independently substituted with a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or 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, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with 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 group.

Y ² to Y ¹³ each independently represent an alkyl 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, which may be substituted with Z ¹ , or Z ² , which may be substituted , 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 amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an aryl group having 6 to 20 carbon atoms or an aryl group having 2 carbon atoms which may be substituted with Z ³ . It is a heteroaryl group of -20.

Z ² is a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an alkyl group having 1 to 20 carbon atoms, which may be substituted with Z ³ , an alkyl group having 2 to carbon atoms It is an alkenyl group of 20 or an alkynyl group of 2 to 20 carbon atoms.

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

A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as a halogen atom.

In addition, as the alkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group of R ⁷ , R ⁸ and Y ² to Y ¹³ , the same as those described above can be mentioned.

Among these, R ⁷ and R ⁸ are preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ , more preferably a hydrogen atom or a methyl group which may be substituted with Z ¹ , and both are most preferably a hydrogen atom. .

L represents the number of repeating units of the divalent alkylene group represented by -(CR ⁷ R ⁸ )- and is an integer of 1 to 20, preferably 1 to 10, more preferably 1 to 5, and 1 to 2 Furthermore, it is more preferable, and 1 is optimal.

In addition, when L is 2 or more, some R< ⁷ > may be mutually same or different, and some R< ⁸ > may also mutually be same or different.

In particular, as X ¹ , -NY ¹ - or a single bond is preferable. Moreover, as Y< ¹ >, a hydrogen atom or a C1-C20 alkyl group which may be substituted with Z< ¹ > is preferable, A hydrogen atom or a methyl group which may be substituted with Z< ¹ > is more preferable, and a hydrogen atom is optimal.

R ¹ to R ⁴ may be each independently substituted with a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or 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, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with 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 is represented (Y ² to Y ¹³ have the same meaning as above). Examples of the halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group include those similar to those described above.

In particular, in formula (1), as R ¹ to R ⁴ , a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , or an aryl group having 6 to 14 carbon atoms which may be substituted with Z ² . Preferably, a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a fluorine atom is more preferable, and both are most preferably a hydrogen atom.

R ⁵ and R ⁶ may be substituted with a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms optionally substituted with Z ¹ , an aryl group having 6 to 14 carbon atoms optionally substituted with Z ² , or Z ² . A diphenylamino group (the -NY ³ Y ⁴ group in which Y ³ and Y ⁴ is a phenyl group optionally substituted with Z ² ) is preferable, and a hydrogen atom, a fluorine atom, or a diphenylamino group optionally substituted with a fluorine atom is more preferable and at the same time, a hydrogen atom or a diphenylamino group is more preferable.

And among these, R1 ^{- R4} is a hydrogen atom, a fluorine atom, a C1 ^- C10 alkyl group which ^may be substituted with a fluorine atom, R5 and R6 are a hydrogen atom, a fluorine atom, and diphenyl which may be substituted with a fluorine atom. A combination of an amino group, X ¹ is -NY ¹ - or a single bond, and Y ¹ is preferably a hydrogen atom or a methyl group, R ¹ to R ⁴ are hydrogen atoms, R ⁵ and R ⁶ are simultaneously a hydrogen atom or a diphenylamino group , X ¹ is -NH- or a combination of a single bond is more preferable.

In the formula (1), m1 and m2 independently represent an integer of 0 or more and satisfy 1≤m1+m2≤20, but considering the balance between the charge transport properties of the resulting thin film and the solubility of the aniline derivative, It is preferable to satisfy 2≦m1+m2≦8, more preferably satisfy 2≦m1+m2≦6, and even more preferably satisfy 2≦m1+m2≦4.

In particular, in Y ¹ to Y ¹³ and R ¹ to R ⁸ , the substituent Z ¹ is preferably a halogen atom or an aryl group having 6 to 20 carbon atoms which may be substituted with Z ³ , and is a halogen atom or Z ³ . The phenyl group which may be substituted is more preferable, and the thing which does not exist (that is, unsubstituted thing) is optimal.

The substituent Z ² is preferably a halogen atom or an alkyl group having 1 to 20 carbon atoms which may be substituted with a halogen atom or Z ³ , more preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms which may be substituted with Z ³ , Those that do not exist (ie are not substituted) are optimal.

And, as for Z ³ , a halogen atom is preferable, a fluorine atom is more preferable, and the thing which does not exist (that is, unsubstituted thing) is optimal.

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

Further, 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.

The method for synthesizing the aniline derivative is not particularly limited, but 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. 2008/032617, International Publication No. 2008/032616, International Publication No. 2008/129947, etc. are mentioned.

Specific examples of the aniline derivative represented by the formula (1) include phenyldianiline, phenyltrianiline, phenyltetraaniline, phenylpentaaniline, tetraaniline (aniline tetramer), octaaniline (aniline octamer), and hexadecaniline (aniline 16). monomer) and those represented by the following formula, but are not limited thereto.

Examples of the organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent on a silicon atom used in the charge-transporting varnish of the present invention include dialkoxysilane and trialkoxysilane having a chlorine-containing monovalent hydrocarbon group as a substituent. Although phosphorus is mentioned, The trialkoxysilane which has a chlorine-containing monovalent|monohydric hydrocarbon group as a substituent is preferable.

Examples of the chlorine-containing monovalent hydrocarbon group include an alkyl chloride group having 1 to 20 carbon atoms, an alkenyl chloride group having 2 to 20 carbon atoms, an alkynyl chloride group having 2 to 20 carbon atoms, and an aryl chloride group having 6 to 20 carbon atoms. However, an alkyl chloride group having 1 to 20 carbon atoms and an aryl chloride group having 6 to 20 carbon atoms are preferable, and an alkyl chloride group having 1 to 10 carbon atoms and an aryl chloride group having 6 to 10 carbon atoms are more preferable.

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

More specifically, chloromethyl group, dichloromethyl group, trichloromethyl group, 1-chloroethyl group, 1,1-dichloroethyl group, 2-chloroethyl group, 2,2-dichloroethyl group, 2,2,2-trichloroethyl group , 1,1,2,2,2-pentachloroethyl group, 3-chloropropyl group, 3,3-dichloropropyl group, 3,3,3-trichloropropyl group, 2,2,3,3,3 -pentachloropropyl group, 1,1,2,2,3,3,3-heptachloropropyl group, etc. are mentioned.

As a specific example of the C2-C20 chlorinated alkenyl group, the group etc. which substituted at least 1 hydrogen atom of the C2-C20 alkenyl group mentioned above with a chlorine atom are mentioned.

More specifically, 1-chloroethenyl group, 3-chloro-1-propenyl group, etc. are mentioned.

As a specific example of a C2-C20 alkynyl chloride group, the group etc. which substituted at least 1 hydrogen atom of the C2-C20 alkynyl group mentioned above with a chlorine atom are mentioned.

More specifically, 1-chloroethynyl group, 3-chloro-1-propynyl group, etc. are mentioned.

As a specific example of a C6-C20 chloride aryl group, the group etc. which substituted at least 1 hydrogen atom of the C6-C20 aryl group mentioned above with a chlorine atom are mentioned.

More specifically, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2,4,6-trichlorophenyl group, perchlorophenyl group, 4-chloro-1-naphthyl group, 4-chloro-2-naphthyl group and the like.

Examples of the organosilane compound that can be suitably used in the present invention include chloroalkyltrialkoxysilane such as chloromethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, and 3-chloropropyltriethoxysilane; -Chlorophenyl trimethoxysilane, 3-chlorophenyl trimethoxysilane, 4-chlorophenyl trimethoxysilane, 2-chlorophenyl triethoxysilane, 3-chlorophenyl triethoxysilane, 4 -Chlorophenyl trialkoxysilane, such as chlorophenyl triethoxysilane, etc. are mentioned, Among these, chlorophenyl trialkoxysilane is preferable, 4-chlorophenyl trialkoxysilane is more preferable, 4-chlorophenyl Trimethoxysilane is optimal.

The amount of the organic silane compound used as a substituent having a chlorine-containing monovalent hydrocarbon group is not particularly limited as long as it does not adversely affect the contact angle of the resulting thin film or the characteristics of the organic EL device, but with respect to the total mass of the charge transporting material and the dopant material , It is usually about 0.1-50 mass %, Preferably it is about 0.5-40 mass %, More preferably, it is about 0.8-30 mass %, More preferably, it is about 1-20 mass %.

The dopant material used in the charge-transporting varnish of the present invention is not particularly limited as long as it dissolves in at least one kind of solvent used in the varnish, and either an inorganic dopant material or an organic dopant material may be used.

Examples of the inorganic dopant material include inorganic acids such as hydrogen chloride, sulfuric acid, nitric acid and phosphoric acid; Aluminum (III) chloride (AlCl ₃ ), titanium (IV) tetrachloride (TiCl ₄ ), boron tribromide (BBr ₃ ), boron trifluoride complex (BF ₃ OEt ₂ ), iron (III) chloride (FeCl) ₃ ), copper(II) chloride (CuCl ₂ ), antimony (V) pentafluoride (SbCl ₅ ), antimony (V) pentafluoride (SbF ₅ ), arsenic pentafluoride (V) (AsF ₅ ), pentafluoride metal halides such as phosphorus (PF ₅ ) and tris(4-bromophenyl)aluminum hexachloroantimonate (TBPAH); halogens such as Cl ₂ , Br ₂ , I ₂ , ICl, ICl ₃ , IBr, and IF ₄ ; Heteropolyacids, such as phosphomolybdenic acid and phosphotungstic acid, etc. are mentioned.

Examples of organic dopant substances include benzenesulfonic acid, tosylic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecylbenzenesulfonic acid, and dihexylbenzenesulfonic acid. Fonic acid, 2,5-dihexylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, 6,7-dibutyl-2-naphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, 3-dodecyl-2-naphthalenesulfonic acid, hexylnaphthalene Sulfonic acid, 4-hexyl-1-naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2-octyl-1-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 7-hexyl-1-naphthalenesulfonic acid, 6-hexyl-2-naphthalene Sulfonic acid, dinonylnaphthalenesulfonic acid, 2,7-dynonyl-4-naphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, 2,7-dynonyl-4,5-naphthalenedisulfonic acid, International Publication No. 2005/ 1,4-benzodioxanedisulfonic acid compound described in 000832, arylsulfonic acid compound described in International Publication No. 2006/025342, arylsulfonic acid compound described in International Publication No. 2009/096352, aryl such as polystyrenesulfonic acid sulfone compounds; non-arylsulfone compounds such as 10-camphorsulfonic acid; organic oxidizing agents such as 7,7,8,8-tetracyanoquinodimethane (TCNQ) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ); there is.

These inorganic and organic dopant substances may be used individually by 1 type, and may be used in combination of 2 or more types.

Among these dopant materials, heteropolyacid is suitable, and by using heteropolyacid as the dopant material, not only the fixed hole capacity from the transparent electrode typified by indium tin oxide (ITO) and indium zinc oxide (IZO), but also aluminum It is possible to obtain a thin film excellent in charge transport properties that exhibits the fixed hole capacity from the metal anode.

Heteropolyacid is a Keggin type represented by Formula (B1) or a Dawson type chemical structure represented by Formula (B2), and has a structure in which a hetero atom is located at the center of the molecule, vanadium (V), molybdenum It is a polyacid formed by condensing isopolyacid which is an oxygen acid, such as (Mo) and tungsten (W), and an oxygen acid of a different element. As the oxygen acid of such a different element, the oxygen acid of silicon (Si), phosphorus (P), and arsenic (As) is mainly mentioned.

Specific examples of the heteropolyacid include phosphomolybdenic acid, silicomolybdenic acid, phosphotungstic acid, siliceous tungstic acid, phosphotungstomolybdenic acid, and the like, and these may be used alone or in combination of two or more. . In addition, the heteropolyacid used by this invention can be obtained as a commercial item, and can also be synthesize|combined by a well-known method.

In particular, when the dopant material is composed of one type of heteropolyacid alone, the one type of heteropolyacid is preferably phosphotungstic acid or phosphomolybdenic acid, and phosphotungstic acid is optimal. Further, when the dopant material is composed of two or more types of heteropolyacids, one of the two or more types of heteropolyacids is preferably phosphotungstic acid or molybdenic phosphophosphoric acid, and more preferably phosphotungstic acid.

In addition, in quantitative analysis such as elemental analysis, heteropolyacid is obtained as a commercial product even if the number of elements is large or small from the structure represented by the general formula, or synthesized appropriately according to a known synthesis method. As long as it is one, it 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 phosphomolybdenic acid is represented by the chemical formula H ₃ (PMo ₁₂ O ₄₀ )·nH ₂ O, respectively. In the analysis, even if the number of P (phosphorus), O (oxygen) or W (tungsten) or Mo (molybdenum) in this formula is large or small, it is obtained as a commercial product, or a known synthesis. As long as it is synthesized appropriately according to the method, it can be used in the present invention. In this case, the mass of the heteropoly acid defined in the present invention is not the mass (phosphotungstic acid content) of pure phosphotungstic acid in a compound or a commercial product, but in a form available as a commercially available product and in a form that can be isolated by a known synthetic method, It means the total mass in the state including other impurities, etc.

Also, an arylsulfonic acid compound may be suitably used as the dopant material. In particular, the arylsulfonic acid compound represented by Formula (2) or (3) is preferable.

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

^Although A2 represents a naphthalene ring or an anthracene ring, a naphthalene ring is preferable.

A ³ represents a divalent to tetravalent perfluorobiphenyl group, p represents the number of bonds between A ¹ and A ³ and is an integer satisfying 2≤p≤4, but A ³ is a divalent perfluorobiphenyl group , it is also preferable that p is 2.

q represents the number of sulfonic acid groups bonded to A ² and is an integer satisfying 1≤q≤4, but 2 is optimal.

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. , at least 3 of A ⁴ to A ⁸ are halogen atoms.

Examples of the halogenated alkyl group having 1 to 20 carbon atoms include trifluoromethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2,2-pentafluoroethyl group, 3,3,3-trifluoro Propyl group, 2,2,3,3,3-pentafluoropropyl group, 1,1,2,2,3,3,3-heptafluoropropyl group, 4,4,4-trifluorobutyl group , 3,3,4,4,4-pentafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 1,1,2,2,3,3,4 and a 4,4-nonafluorobutyl group.

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

Other examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms include the same ones as described above, but the 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, Further, at least 3 of A ⁴ to A ⁸ are preferably a fluorine atom, 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 a fluorinated alkyl group having 2 to 5 carbon atoms It is a fluorinated alkenyl group, and at least three of A ⁴ to A ⁸ are more preferably a fluorine atom, and a hydrogen atom, a fluorine atom, a cyano group, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkyl group having 1 to 5 carbon atoms. It is a perfluoroalkenyl group of, and ^it is further more preferable that A4, ^A5 , and ^A8 are a fluorine atom.

In addition, a perfluoroalkyl group is a group in which all the hydrogen atoms of an alkyl group were substituted by fluorine atoms, and a perfluoroalkenyl group is a group in which all the hydrogen atoms of an alkenyl group were substituted by fluorine atoms.

r represents the number of sulfonic acid groups couple|bonded with the naphthalene ring, and is an integer which satisfies 1≤r≤4, 2-4 are preferable and 2 is optimal.

The molecular weight of the arylsulfonic acid compound used as the dopant material is not particularly limited, but considering solubility in an organic solvent when used together with a charge-transporting oligomer, it is preferably 2000 or less, and more preferably 1500 or less.

Hereinafter, in this invention, although the specific example of the arylsulfonic acid compound suitable as a dopant substance is given, it is not limited to these.

When a dopant material is included in the charge-transporting varnish of the present invention, the amount of the dopant material to be used is appropriately determined in consideration of the type of dopant material, the desired degree of charge-transporting property, and the like. , it is in the range of 0.01 to 50 with respect to the charge-transporting substance 1 in terms of mass ratio.

As an organic solvent used when preparing a charge-transporting varnish, the high solubility solvent which can melt|dissolve a charge-transporting substance, a dopant substance, and an organosilane compound favorably can be used.

Examples of such a highly soluble solvent include cyclohexanone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and 1,3-dimethyl-2-imida. Although organic solvents, such as zolidinone, diethylene glycol monomethyl ether, and N,N- dimethyl isobutyric acid amide, are mentioned, It is not limited to these. These solvents can be used individually by 1 type or in mixture of 2 or more types, The usage-amount can be made into 5-100 mass % with respect to the whole solvent used for a varnish.

In addition, it is preferable that the charge-transporting substance, the dopant substance, and the organosilane compound are all completely dissolved or uniformly dispersed in the solvent, more preferably completely dissolved.

Further, in the present invention, the varnish has a viscosity of 10 to 200 mPa·s, particularly 35 to 150 mPa·s at 25° C., and a high viscosity organic solvent having a boiling point of 50 to 300° C., particularly 150 to 250° C. at normal pressure (atmospheric pressure), at least By containing one type, adjustment of the viscosity of a varnish becomes easy, as a result, a thin film with high flatness is supplied with good reproducibility, and varnish preparation suitable for the application|coating method to be used is attained.

Examples of the high-viscosity organic solvent include cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, Triethylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, propylene glycol, hexylene glycol, etc. , but is not limited thereto. These solvents may be used independently and may be used in mixture of 2 or more types.

It is preferable that the addition ratio of the high-viscosity organic solvent with respect to the whole solvent used for the varnish of this invention exists in the range where solid does not precipitate, As long as solid does not precipitate, the addition ratio is preferably 5-90 mass %.

In addition, for the purpose of improving wettability to the substrate, adjusting the surface tension of the solvent, adjusting the polarity, adjusting the boiling point, etc., other solvents are 1 to 90% by mass, preferably 1 to the total solvent used in the varnish. You can also mix in the ratio of -50 mass %.

As such a solvent, for example, propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol Cole monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diacetone Alcohol, gamma -butyrolactone, ethyl lactate, n-hexyl acetate etc. are mentioned, However, It is not limited to these. These solvents can be used individually by 1 type or in mixture of 2 or more types.

Although the viscosity of the varnish of this invention is suitably set according to the thickness etc. of the thin film to produce, solid content concentration, etc., it is 1-50 mPa*s at 25 degreeC normally. In addition, although the surface tension of the varnish of this invention is set suitably according to the application method etc. to be used, it is 20-50 mN/m normally.

In addition, the solid content concentration of the charge-transporting varnish in the present invention is appropriately set in consideration of the viscosity and surface tension of the varnish, the thickness of the thin film to be produced, etc. Considering improvement, Preferably it is about 0.5-5.0 mass %, More preferably, it is about 1.0-3.0 mass %. In addition, the solid content means a charge-transporting material and a dopant material.

A charge-transporting thin film can be formed on the substrate by applying and firing the charge-transporting varnish described above on the substrate.

The method for applying 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 brush coating method, an inkjet method, a spraying method, a slit coating method, and the like. It is preferable to control the viscosity and surface tension of

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

The firing temperature is appropriately set within the range of about 100 to 260° C. in consideration of the purpose of the resulting thin film, the degree of charge transport properties imparted to the resulting thin film, the kind and boiling point of the solvent, etc. When using as an injection|pouring layer, about 140-250 degreeC is preferable, and about 145-240 degreeC is more preferable.

In addition, at the time of baking, for the purpose of expressing higher uniform film-forming property or advancing a reaction on a base material, you may give two or more steps of temperature change, and heating is suitable, for example, such as a hot plate and oven, This can be done using the device.

Although the film thickness of a charge-transporting thin film is not specifically limited, When using as a hole injection layer in organic electroluminescent element, 5-200 nm is preferable. As a method of changing a film thickness, there exist methods, such as changing the solid content concentration in a varnish, and changing the amount of solution on the board|substrate at the time of application|coating.

The charge-transporting thin film of the present invention described above has excellent charge-transporting properties and flatness. In addition, on the thin film, organic solvents such as toluene, xylene, chloroform, 3-phenoxytoluene and tetralin contained in a varnish used when forming a hole transport layer or a light emitting layer of an organic EL device by a wet process are A suitable coating film can be formed.

Therefore, the said thin film obtained from the charge-transporting varnish of this invention can be used suitably for electronic devices, such as an organic electroluminescent element which has a multilayer structure formed by a wet process.

The example of the manufacturing method of the OLED element which has a hole injection layer which consists of a thin film obtained from the charge-transporting varnish of this invention is as follows.

The electrode substrate to be used is preferably cleaned by liquid washing with detergent, alcohol, pure water, etc. in advance. For example, in the case of an anode substrate, it is preferable to perform surface treatment such as UV ozone treatment or oxygen-plasma treatment immediately before use. Do. However, when the anode material has an organic substance as a main component, it is not necessary to perform surface treatment.

By the above method, the charge-transporting varnish of the present invention is applied and fired on the anode substrate to produce a hole-transporting layer on the electrode. This is introduced into a vacuum vapor deposition apparatus, and a hole transport layer, a light emitting layer, an electron transport layer, an electron transport layer/hole block layer, and a cathode metal are sequentially deposited to obtain an OLED device. Moreover, you may provide an electron blocking layer between a light emitting layer and a positive hole transport layer as needed.

Examples of the anode material include a transparent electrode typified by indium tin oxide (ITO) and indium zinc oxide (IZO), and a metal anode made of a metal typified by aluminum or an alloy thereof. . Polythiophene derivatives or polyaniline derivatives having high charge transport properties can also be used.

In addition, as other metals constituting the metal anode, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, Cadmium, Indium, Scandium, Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Hafnium, Thallium, Tungsten, Rhenium, Osmium, Iridium, Osmium, Iridium Although gold, titanium, lead, bismuth, these alloys, etc. are mentioned, It is not limited to these.

As a material for forming the hole transport layer, (triphenylamine)dimer derivative, [(triphenylamine)dimer]spirodimer, N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl) -Benzidine (α-NPD), N,N'-bis(naphthalen-2-yl)-N,N'-bis(phenyl)-benzidine, N,N'-bis(3-methylphenyl)-N,N' -Bis(phenyl)-benzidine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-9,9-spirobifluorene, N,N'-bis(naphthalene-1 -yl)-N,N'-bis(phenyl)-9,9-spirobifluorene, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-9,9- Dimethyl-fluorene, N,N'-bis(naphthalen-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(naphthalen-1-yl)-N,N'-bis(phenyl)-9,9- Diphenyl-fluorene, N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine, 2,2',7,7'-tetra kiss (N,N-diphenylamino)-9,9-spirobifluorene, 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'-tetrakis[N-naphthalenyl (phenyl)-amino]-9,9-spirobifluorene, N ,N'-bis(phenanthren-9-yl)-N,N'-bis(phenyl)-benzidine, 2,2'-bis[N,N-bis(biphenyl-4-yl)amino]-9 ,9-spirobifluorene, 2,2'-bis(N,N-diphenylamino)-9,9-spirobifluorene, di-[4-(N,N-di(p-tolyl) )Amino)-phenyl]cyclohexane, 2,2',7,7'-tetra(N,N-di(p-tolyl))amino-9,9-spirobifluorene, N,N,N ',N'-Tetra-naphthalen-2-yl-benzidine, N,N,N',N'-tetra-(3-methylphenyl)-3,3'-dimethylbenzidine, N,N'-di(naphthalene yl)-N,N'-di(naphthalen-2-yl) -Benzidine, N,N,N',N'-tetra(naphthalenyl)-benzidine, N,N'-di(naphthalen-2-yl)-N,N'-diphenylbenzidine-1,4-diamine , N ¹ ,N ⁴ -diphenyl-N ¹ ,N ⁴ -di(m-tolyl)benzene-1,4-diamine, N ² ,N ² ,N ⁶ ,N ⁶ -tetraphenylnaphthalene-2,6 -diamine, tris(4-(quinolin-8-yl)phenyl)amine, 2,2'-bis(3-(N,N-di(p-tolyl)amino)phenyl)biphenyl, 4,4',4''-tris[3-methylphenyl (phenyl)amino]triphenylamine (m-MTDATA), 4,4',4''-tris[1-naphthyl (phenyl)amino]triphenylamine (1- triarylamines such as TNATA), 5,5''-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2''-terthiophene (BMA-3T) ) and the like oligothiophenes.

Examples of the material for forming the light emitting layer include tris(8-quinolinolate)aluminum(III)(Alq ₃ ), bis(8-quinolinolate)zinc(II)(Znq ₂ ), and bis(2-methyl-8- Quinolinoleate)-4-(p-phenylphenolate)aluminum(III)(BAlq), 4,4'-bis(2,2-diphenylvinyl)biphenyl, 9,10-di(naphthalene-2) -yl)anthracene, 2-t-butyl-9,10-di(naphthalen-2-yl)anthracene, 2,7-bis[9,9-di(4-methylphenyl)-fluoren-2-yl]- 9,9-di(4-methylphenyl)fluorene, 2-methyl-9,10-bis(naphthalen-2-yl)anthracene, 2-(9,9-spirobifluoren-2-yl)-9 , 9-spirobifluorene, 2,7-bis (9,9-spirobifluoren-2-yl) -9,9-spirobifluorene, 2- [9,9-di (4 -Methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl)fluorene, 2,2'-dipyrenyl-9,9-spirobifluorene, 1,3,5- Tris(pyren-1-yl)benzene, 9,9-bis[4-(pyrenyl)phenyl]-9H-fluorene, 2,2'-bi(9,10-diphenylanthracene), 2,7- Dipyrenyl-9,9-spirobifluorene, 1,4-di(pyren-1-yl)benzene, 1,3-di(pyren-1-yl)benzene, 6,13-di(biphenyl) -4-yl)pentacene, 3,9-di(naphthalen-2-yl)perylene, 3,10-di(naphthalen-2-yl)perylene, tris[4-(pyrenyl)-phenyl]amine , 10,10'-di(biphenyl-4-yl)-9,9'-bianthracene, N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-[1,1 ': 4',1'': 4'',1''-quaterphenyl]-4,4'''-diamine, 4,4'-di[10-(naphthalen-1-yl)anthracene- 9-yl]biphenyl, dibenzo{[f,f']-4,4',7,7'-tetraphenyl}diindeno[1,2,3-cd:1',2',3' -lm]perylene, 1-(7-(9,9'-bianthracen-10-yl)-9,9-dimethyl-9H-fluoren-2-yl)pyrene, 1-(7-(9) ,9'-Bianthracen-10-yl)-9,9-dihexyl-9H-fluoren-2-yl)pyrene, 1,3-bis(carbazol-9-yl)benzene, 1,3,5 -tris(carbazol-9-yl)benzene, 4,4',4''-tris(carbazol-9-yl)triphenylamine, 4,4'-bis(carbazol-9-yl)biphenyl, 4,4'-bis(carbazole-9 -yl)-2,2'-dimethylbiphenyl, 2,7-bis(carbazol-9-yl)-9,9-dimethylfluorene, 2,2',7,7'-tetrakis ( Carbazol-9-yl)-9,9-spirobifluorene, 2,7-bis(carbazol-9-yl)-9,9-di(p-tolyl)fluorene, 9,9-bis [4-(carbazol-9-yl)-phenyl]fluorene, 2,7-bis(carbazol-9-yl)-9,9-spirobifluorene, 1,4-bis(triphenylsilyl) ) Benzene, 1,3-bis (triphenylsilyl) benzene, bis (4-N, N-diethylamino-2-methylphenyl) -4-methylphenylmethane, 2,7-bis (carbazol-9-yl) )-9,9-dioctylfluorene, 4,4''-di(triphenylsilyl)-p-terphenyl, 4,4'-di(triphenylsilyl)biphenyl, 9-(4-t- Butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole, 9-(4-t-butylphenyl)-3,6-ditrityl-9H-carbazole, 9-(4-t -Butylphenyl)-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-carbazol-9-yl)phenyl ) pyridine, 9,9-spirobifluoren-2-yl-diphenyl-phosphine oxide, 9,9'-(5-(triphenylsilyl)-1,3-phenylene)bis(9H-carba) sol), 3-(2,7-bis(diphenylphosphoryl)-9-phenyl-9H-fluoren-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-di(9H-carbazol-9-yl)-1,10-phenantrol Lin, 2,2'-bis(4-(carbazol-9-yl)phenyl)biphenyl, 2,8-bis(diphenylphosphoryl)dibenzo[b,d]thiophene, bis(2-methylphenyl) ) diphenylsilane, bis[3,5-di(9H-carbazol-9-yl)phenyl]diphenylsilane, 3,6-bi S(carbazol-9-yl)-9-(2-ethyl-hexyl)-9H-carbazole, 3-(diphenylphosphoryl)-9-(4-(diphenylphosphoryl)phenyl)-9H- Carbazole, 3,6-bis[(3,5-diphenyl)phenyl]-9-phenylcarbazole, etc. are mentioned, You may form a light emitting layer by co-evaporating with a light emitting dopant.

As the luminescent dopant, 3-(2-benzothiazolyl)-7-(diethylamino)cumarin, 2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H ,11H-10-(2-benzothiazolyl)quinolidino[9,9a,1gh]cumarin, quinacridone, N,N'-dimethyl-quinacridone, tris(2-phenylpyridine)iridium (III)(Ir(ppy) ₃ ), bis(2-phenylpyridine)(acetylacetonate)iridium(III)(Ir(ppy) ₂ (acac)), tris[2-(p-tolyl)pyridine]iridium (III)(Ir(mppy) ₃ ), 9,10-bis[N,N-di(p-tolyl)amino]anthracene, 9,10-bis[phenyl(m-tolyl)amino]anthracene, bis[2 -(2-hydroxyphenyl)benzothiazolate]zinc (II), N ¹⁰ ,N ¹⁰ ,N ^{10 '} ,N ^10' -tetra(p-tolyl)-9,9'-bianthracene-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 '} -Dinaphthalenyl-9,9'-bianthracene-10,10'-diamine, 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-bi Phenyl, perylene, 2,5,8,11-tetra-t-butylperylene, 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene, 4,4'-bis[4 -(di-p-tolylamino)styryl]biphenyl, 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene, bis(3,5- Difluoro)-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III), 4,4'-bis[4-(diphenylamino)styryl]biphenyl, bis(2 ,4-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate iridium (III), N,N'-bis(naphthalen-2-yl)-N,N'-bis(phenyl)- Tris(9,9-dimethylfluorenylene), 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)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzene amines, fac- Iridium(III)tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2 ^' ), mer-iridium(III)tris(1-phenyl-3-methylbenzimidazoline- 2-ylidene-C,C ^2' ), 2,7-bis[4-(diphenylamino)styryl]-9,9-spirobifluorene, 6-methyl-2-(4-(9) -(4-(6-methylbenzo[d]thiazol-2-yl)phenyl)anthracen-10-yl)phenyl)benzo[d]thiazole, 1,4-di[4-(N,N-di Phenyl)amino]styrylbenzene, 1,4-bis(4-(9H-carbazol-9-yl)styryl)benzene, (E)-6-(4-(diphenylamino)styryl)-N ,N-diphenylnaphthalen-2-amine, bis(2,4-difluorophenylpyridinato)(5-(pyridin-2-yl)-1H-tetrazolate)iridium (III), bis( 3-Trifluoromethyl-5-(2-pyridyl)pyrazole)((2,4-difluorobenzyl)diphenylphosphinate)iridium(III), bis(3-trifluoromethyl-5 -(2-pyridyl)pyrazolate)(benzyldiphenylphosphinate)iridium(III), bis(1-(2,4-difluorobenzyl)-3-methylbenzimidazolium)(3- (trifluoromethyl)-5-(2-pyridyl)-1,2,4-triazolate)iridium(III), bis(3-trifluoromethyl-5-(2-pyridyl)pyrazole rate) (4',6'-difluorophenylpyridinate)iridium(III), bis(4',6'-difluorophenylpyridinato)(3,5-bis(trifluoromethyl) )-2-(2'-pyridyl)pyrrolate)iridium(III), bis(4',6'-difluorophenylpyridinato)(3-(trifluoromethyl)-5-(2) -Pyridyl)-1,2,4-triazolate)iridium (III), (Z)-6-mesityl-N-(6-mesitylquinoline-2(1H)-ylidene)quinoline-2- Amine-BF ₂ , (E)-2-(2-(4-(dimethylamino)styryl)-6-methyl-4H-pyran-4-ylidene)malononitrile, 4-(dicyano Methylene)-2-methyl-6-juulrolidyl-9-enyl-4H-pyran, 4-(dicyanomethylene)-2-methyl-6-(1,1,7,7-tetramethyljurolidyl) -9-enyl)-4H-pyran, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljuulrolidin-4-yl-vinyl) -4H-pyran, tris(dibenzoylmethane)phenanthrolineeuropium (III), 5,6,11,12-tetraphenylnaphthacene, bis(2-benzo[b]thiophen-2-yl-pyridine) (acetylacetonate) iridium (III), tris (1-phenylisoquinoline) iridium (III), bis (1-phenylisoquinoline) (acetylacetonate) iridium (III), bis [1- (9,9-) Dimethyl-9H-fluoren-2-yl)-isoquinoline](acetylacetonate)iridium(III), bis[2-(9,9-dimethyl-9H-fluoren-2-yl)quinoline]( Acetylacetonate) iridium (III), tris [4,4'-di-t-butyl- (2,2')-bipyridine] ruthenium (III) bis (hexafluorophosphate), tris (2-phenyl) Quinoline) iridium (III), bis (2-phenylquinoline) (acetylacetonate) iridium (III), 2,8-di-t-butyl-5,11-bis (4-t-butylphenyl)-6, 12-diphenyltetracene, bis(2-phenylbenzothiazolate)(acetylacetonate)iridium(III), 5,10,15,20-tetraphenyltetrabenzoporphyrinplatinum, osmium(II)bis(3- Trifluoromethyl-5-(2-pyridine)-pyrazolate)dimethylphenylphosphine, osmium(II)bis(3-(trifluoromethyl)-5-(4-t-butylpyridyl)-1 ,2,4-triazolate)diphenylmethylphosphine, osmium(II)bis(3-(trifluoromethyl)-5-(2-pyridyl)-1,2,4-triazole)dimethylphenyl Phosphine, osmium(II)bis(3-(trifluoromethyl)-5-(4-t-butylpyridyl)-1,2,4-triazolate)dimethylphenylphosphine, bis[2-( 4-n-hexylphenyl)quinoline](acetylacetonate)iridium(III), tris[2-(4-n-hexylphenyl)quinoline]iridium(III), tris[2-phenyl-4-methylquinoline]iridium (III), bis(2-phenylquinoline)(2-(3-methylphenyl)pyridinate)iridium(III),bis(2-(9,9-diethyl-fluoren-2-yl)-1- Phenyl-1H-benzo [d] imidazolato) (acetylacetonate) iridium (III), bis (2-phenylpyridine) (3- (pyridin-2-yl) -2H-chromen-2-onate) Iridium (III), bis (2-phenylquinoline) (2,2,6,6-tetramethyl Tylheptane-3,5-dionate)iridium(III), bis(phenylisoquinoline)(2,2,6,6-tetramethylheptane-3,5-dionate)iridium(III), iridium(III) )bis(4-phenylthieno[3,2-c]pyridinato-N,C ^{2 '} )acetylacetonate, (E)-2-(2-t-butyl-6-(2-( 2,6,6-trimethyl-2,4,5,6-tetrahydro-1H-pyrrolo[3,2,1-ij]quinolin-8-yl)vinyl)-4H-pyran-4-ylidene ) malononitrile, bis(3-trifluoromethyl-5-(1-isoquinolyl)pyrazolate)(methyldiphenylphosphine)ruthenium, bis[(4-n-hexylphenyl)isoquinoline] (acetylacetonate) iridium (III), platinum (II) octaethyl pophine, bis (2-methyldibenzo [f,h] quinoxaline) (acetylacetonate) iridium (III), tris [(4-n- Hexylphenyl) isoquinoline] iridium (III) etc. are mentioned.

As a material for forming the electron transport layer/hole blocking layer, 8-hydroxyquinolinolate-lithium, 2,2',2''-(1,3,5-benzintolyl)-tris(1-phenyl-1- H-benzimidazole), 2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole, 2,9-dimethyl-4,7-diphenyl -1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, bis(2-methyl-8-quinolinolate)-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-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole, 2,9-bis(naphthalen-2-yl)-4,7- Diphenyl-1,10-phenanthroline, 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-oxadiazo-5-yl]benzene, tris(2,4,6-trimethyl -3-(pyridin-3-yl)phenyl)borane, 1-methyl-2-(4-(naphthalen-2-yl)phenyl)-1H-imidazo[4,5f][1,10]phenantrol Lin, 2-(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline, phenyl-dipyrenylphosphine oxide, 3,3',5,5'-tetra[(m -Pyridyl)-phen-3-yl]biphenyl, 1,3,5-tris[(3-pyridyl)-phen-3-yl]benzene, 4,4'-bis(4,6-diphenyl -1,3,5-triazin-2-yl)biphenyl, 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene, bis(10-hydroxybenzo[h]qui Nolineto)beryllium, diphenylbis(4-(pyridin-3-yl)phenyl)silane, 3,5-di(pyren-1-yl)pyridine, etc. are mentioned.

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

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

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

Although the manufacturing method of the PLED element using the charge-transporting varnish of this invention is not specifically limited, The following method is mentioned.

In manufacturing the OLED device, instead of performing vacuum deposition of the hole transporting layer, the light emitting layer, the electron transporting layer, and the electron injection layer, the hole transporting polymer layer and the light emitting polymer layer are sequentially formed by the charge transporting varnish of the present invention. A PLED device having a thin film can be fabricated.

Specifically, the charge transporting varnish of the present invention is applied on an anode substrate to prepare a hole injection layer by the above method, a hole transporting polymer layer and a light emitting polymer layer are sequentially formed thereon, and a cathode is further deposited to form a PLED device. do it with

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

As a method for forming the hole transporting polymer layer and the light emitting polymer layer, a solvent is added to a hole transporting polymer material or a light emitting polymer material, or a material added with a dopant material thereto, dissolved or uniformly dispersed, and a hole injection layer or a hole transporting polymer layer After apply|coating on top, the method of forming into a film by baking each is mentioned.

As the hole transporting polymer material, 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)], poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]-and capped with polysilses Quoxane, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)], etc. can

Examples of the luminescent polymer material include polyfluorene derivatives such as poly(9,9-dialkylfluorene) (PDAF), poly(2-methoxy-5-(2'-ethylhexoxy)-1,4-phenylenevinyl) and polyphenylene vinylene derivatives such as ene) (MEH-PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

Examples of the solvent include toluene, xylene, chloroform, 3-phenoxytoluene, and tetralin, and examples of the dissolution or homogeneous dispersion method include stirring, heating stirring, ultrasonic dispersion and the like.

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 brush coating method. In addition, it is preferable to perform application|coating under inert gas, such as nitrogen and argon.

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

Example

Hereinafter, the present invention will be described in more detail by way of Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, the apparatus used is as follows.

(1) Substrate cleaning: Choshu Sangyo Co., Ltd. substrate cleaning device (pressure-reduced plasma method)

(2) Varnish application: Mikasa Co., Ltd. spin coater MS-A100

(3) Film thickness measurement: Kosaka Kenkyusho Co., Ltd. micro-shape measuring instrument Surfcoder ET-4000

(4) Contact angle measurement: Kyowa Kaimen Chemical Co., Ltd. contact angle meter

(5) Fabrication of element: Choshu Sangyo Co., Ltd. multi-function vapor deposition system system C-E2L1G1-N

(6) Measurement of luminance, etc. of EL elements: I-V-L measurement system manufactured by Techworld Co., Ltd.

[1] Preparation of charge-transporting varnish

[Example 1]

0.062 g of an aniline derivative represented by Formula [1] synthesized according to the method described in International Publication No. 2013/084664 and 0.309 g of tungstic phosphotungstic acid (manufactured by Nippon Shinkinzoku Co., Ltd.) in a nitrogen atmosphere with 1,3-dimethyl It was dissolved in 4.8 g of -2-imidazolidinone (hereinafter abbreviated as DMI). To the obtained solution, 5.4 g of 2,3-butanediol (hereinafter abbreviated as 2,3-BD) and 1.8 g of ethyldiglycol acetate (hereinafter abbreviated as EDGAc) were added and stirred. After adding 0.011 g of 4-chlorophenyl trimethoxysilane to the obtained solution, it stirred again, and the charge-transporting varnish was prepared (solid content 3.0 mass %).

[Comparative Example 1-1]

0.062 g of an aniline derivative represented by Formula [1] and 0.309 g of phosphotungstic acid (manufactured by Nippon Shinkinzoku Co., Ltd.) were dissolved in 4.8 g of DMI in a nitrogen atmosphere. To the obtained solution, 5.4 g of 2,3-BD and 1.8 g of EDGAc were added and stirred to prepare a charge-transporting varnish (solid content 3.0% by mass).

[Comparative Example 1-2]

Except having changed 0.011 g of 4-chlorophenyl trimethoxysilane into 0.011 g of ethyl trimethoxysilane, it carried out similarly to Example 1, and prepared the charge-transporting varnish (solid content 3.0 mass %).

[Comparative Example 1-3]

A charge-transporting varnish 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(3,3,3-trifluoropropyl)silane ( solid content 3.0% by mass).

[Comparative Example 1-4]

Except having changed 0.011 g of 4-chlorophenyl trimethoxysilane into 0.011 g of trimethoxy (phenyl) silane, it carried out similarly to Example 1, and prepared the charge-transporting varnish (3.0 mass % of solid content).

[Comparative Example 1-5]

A charge-transporting varnish 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 triethoxy(perfluorophenyl)silane (solid content 3.0% by mass).

With respect to the charge-transporting varnishes produced 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 on an indium tin oxide (ITO) substrate by spin coating, dried in the air at 80° C. for 1 minute on a hot plate, and fired at 230° C. for 15 minutes to prepare a thin film. With respect to the obtained thin film, the contact angle of 3-phenoxytoluene and tetralin was measured. A result is shown in Table 1.

organosilane compounds Contact angle (°) 3-Phenoxytoluene tetralin Example 1 4-Chlorophenyltrimethoxysilane 3° or less 3° or less Comparative Example 1-1 doesn't exist 3° or less 3° or less Comparative Example 1-2 Ethyl trimethoxysilane 20 17.5 Comparative Example 1-3 Trimethoxy (3,3,3-trifluoropropyl) silane 27.7 34.3 Comparative Example 1-4 trimethoxy(phenyl)silane 3° or less 3° or less Comparative Example 1-5 Triethoxy (perfluorophenyl) silane 19.1 18.3

When the contact angle of the solvent used for the upper layer material is 10 degrees or more, the upper layer material may be splashed off at the time of lamination|stacking, and a uniform film|membrane may not be obtained. As shown in Table 1, the contact angle of the solvent on the thin film prepared from the charge-transporting varnish of Example 1 to which 4-chlorophenyltrimethoxysilane, which is an organosilane compound having a chlorine-containing monovalent hydrocarbon group, was added was organic silane. The contact angle of the solvent on the thin film prepared from the charge-transporting varnish of Comparative Example 1-1 in which the phosphorus compound was not added did not change and the added chlorine-containing organosilane compound did not affect the wettability of the upper layer. Moreover, since the contact angle is 3 degrees or less, it does not come off at the time of lamination|stacking, and the applicability|paintability of an upper layer is favorable, and it is expected that the upper layer material is uniformly formed into a film.

[2] Two-layer device

A glass substrate (hereinafter abbreviated as ITO substrate) having a size of 25 mm × 25 mm × 0.7 t was used as the substrate for evaluating the electrical properties. The ITO substrate was used after removing impurities on the surface using an O ₂ plasma cleaning apparatus (150 W, 30 seconds).

[Example 2]

The varnish obtained in Example 1 was applied to the ITO substrate using a spin coater, dried at 80° C. for 1 minute, and further fired at 230° C. for 15 minutes in an atmospheric atmosphere, and a 30 nm uniform thin film on the ITO substrate. (hole injection layer) was formed. On it, a thin film of N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD) and aluminum was sequentially laminated using a vapor deposition apparatus (vacuum degree of 1.0×10 ^-5 Pa). and a two-layer device was obtained. The film thicknesses were 30 nm and 100 nm, respectively, and the deposition rate was 0.2 nm/sec.

In addition, in order to prevent characteristic deterioration due to the influence of oxygen in the air, water, etc., the two-layer element was sealed with a sealing substrate, and then the characteristics were evaluated. Sealing was performed in the following procedure.

In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -85° C. or less, the element was placed on a sealing substrate, and the sealing substrate was bonded to each other with an adhesive (MORESCO Co., Ltd., Moresco Moisture Cut WB90US(P)). At this time, a desiccant (manufactured by Dynic Co., Ltd., HD-071010W-40) was put together with the element in the sealing substrate. After irradiating UV light (wavelength 365 nm, irradiation amount 6,000 mJ/cm ² ) with respect to the bonded sealing substrate, it annealed at 80 degreeC for 1 hour, and the adhesive material was hardened.

[Comparative Examples 2-1 to 2-5]

A two-layer element was produced in the same manner as in Example 2 except that the varnish obtained in Comparative Examples 1-1 to 1-5 was used instead of the varnish obtained in Example 1.

For each produced two-layer element, the current density at a driving voltage of 3 V was measured. A result is shown in Table 2.

current density
(mA/cm ² ) Example 2 1470 Comparative Example 2-1 950 Comparative Example 2-2 1190 Comparative Example 2-3 1590 Comparative Example 2-4 970 Comparative Example 2-5 1720

As shown in Table 2, the thin film prepared from the varnish of Example 1 was obtained by adding a varnish not containing an organosilane compound (Comparative Example 1-1) or an organosilane compound containing no halogen atom. It turns out that it has the outstanding charge transport property compared with the thin film produced from the varnish (Comparative Examples 1-2, 1-4).

Moreover, it turns out that it has a charge-transporting property of the same degree as compared with the thin film produced from the varnish (Comparative Examples 1-3, 1-5) to which the fluorine-containing organosilane compound was added.

[3] Manufacturing and characterization of organic EL devices

[Example 3]

Using the varnish obtained in Example 1, in the same manner as in Example 2, a 30 nm uniform thin film was formed on the ITO substrate.

Next, with respect to the ITO substrate on which the thin film was formed, N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD) using a vapor deposition apparatus (vacuum degree 1.0×10 ^-5 Pa) ) was laminated at 30 nm. Subsequently, CBP and Ir(PPy) ₃ were co-deposited. For co-deposition, the deposition rate was controlled so that the concentration of Ir(PPy) ₃ was 6%, and 40 nm was laminated. Then, thin films of BAlq, lithium fluoride, and aluminum were sequentially laminated to obtain an organic EL device. At this time, the deposition rate was performed under the conditions of 0.2 nm/sec for BAlq and aluminum, and 0.02 nm/sec for lithium fluoride, respectively, and the film thicknesses were set to 20 nm, 0.5 nm, and 100 nm, respectively.

Then, in the same manner as in Example 2, the organic EL element was sealed with the sealing substrate.

[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 of the fabricated elements, the luminance, current density, and current efficiency at a driving voltage of 10 V were measured. A result is shown in Table 3.

current density
(mA/cm ² ) luminance
(cd/m ² ) current efficiency
(cd/A) Example 3 32 7900 24.4 Comparative Example 3-1 30 7300 24.4

As shown in Table 3, when compared with the device of Comparative Example 3-1, it can be seen that the luminance of the device of Example 3 is high and other device characteristics are also maintained.

In addition, as can be understood from the results of Tables 1 to 3, 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, while maintaining the coatability of the upper layer , it was possible to realize good luminance characteristics.

Claims (10)

A charge-transporting substance, a dopant substance, an organosilane compound having a chlorine-containing monovalent hydrocarbon group as a substituent, and an organic solvent;
The charge-transporting varnish characterized in that the organosilane compound having the chlorine-containing monovalent hydrocarbon group as a substituent is chlorophenyltrialkoxysilane. The method of claim 1,
The charge-transporting varnish, characterized in that the chlorophenyl trialkoxysilane is 4-chlorophenyltrialkoxysilane. 3. The method of claim 2,
The charge-transporting varnish, characterized in that the 4-chlorophenyl trialkoxysilane is 4-chlorophenyl trimethoxysilane. The method of claim 1,
A charge-transporting varnish, wherein the charge-transporting material is a charge-transporting oligomer. The method of claim 1,
A charge-transporting varnish, characterized in that the dopant material is a heteropolyacid. A charge-transporting thin film produced using the charge-transporting varnish according to any one of claims 1 to 5. An electronic device having the charge-transporting thin film according to claim 6 . An organic electroluminescent device having the charge-transporting thin film according to claim 6 . 9. The method of claim 8,
The organic electroluminescence device, characterized in that the charge-transporting thin film is a hole injection layer or a hole transport layer. A method for producing a charge-transporting thin film, comprising applying the charge-transporting varnish according to any one of claims 1 to 5 on a substrate and evaporating the solvent.