WO2014141998A1

WO2014141998A1 - Charge-transporting varnish

Info

Publication number: WO2014141998A1
Application number: PCT/JP2014/055781
Authority: WO
Inventors: 直樹中家; 春香古賀
Original assignee: 日産化学工業株式会社
Priority date: 2013-03-11
Filing date: 2014-03-06
Publication date: 2014-09-18
Also published as: KR102270150B1; KR20150127675A; TW201500333A; JPWO2014141998A1; CN105074949A; CN105074949B; JP6135752B2; TWI620731B

Abstract

Provided is a charge-transporting varnish that contains: a charge-transporting substance comprising an aniline derivative that is represented by formula (1); a dopant substance comprising a heteropoly acid; an organosilane compound; and an organic solvent. The charge-transporting varnish can be fired at temperatures below 200 °C, and a thin film that is produced under such firing conditions has a high degree of flatness, has high charge-transporting properties, and exhibits excellent luminance characteristics when applied to an organic EL element. (In the formula, X¹ represents -NY¹- or the like, Y¹ and R¹-R⁶ each independently represent a hydrogen atom or the like, m and n each independently represent an integer of 0 or more, and 1 ≤ m + n ≤ 20 is satisfied. When m or n is 0, X¹ represents -NY¹-.)

Description

Charge transport varnish

The present invention relates to a charge transporting varnish. More specifically, the present invention relates to a charge transporting varnish containing a charge transporting material composed of a predetermined aniline derivative, a dopant material composed of a heteropolyacid, and an organosilane compound.

In an organic electroluminescence (hereinafter referred to as organic EL) element, a charge transporting thin film made of an organic compound is used as a light emitting layer or a charge injection layer.
The method for forming the charge transporting thin film is roughly classified into a dry process typified by vapor deposition and a wet process typified by spin coating. Compared with the dry process and the wet process, the wet process can efficiently produce a thin film with a large area and high flatness. Therefore, in the field where a large area of the thin film such as an organic EL element is desired, the thin film is obtained by the wet process. Is often formed.

In view of this point, the present inventors have developed a charge transporting varnish for producing a charge transporting thin film applicable to various electronic devices by a wet process (see Patent Document 1).
However, in the recent organic EL element field, a substrate made of an organic compound has come to be used instead of a glass substrate because of the trend toward lighter and thinner devices, and it can be fired at a lower temperature than before, In such a case, a varnish that provides a thin film having good charge transportability is also demanded. However, existing varnishes may not sufficiently meet these requirements.

JP 2002-151272 A

The present invention has been made in view of the above circumstances, and can be fired at a temperature lower than 200 ° C., and the thin film produced under such firing conditions has high flatness and high charge transportability. An object of the present invention is to provide a charge transporting varnish capable of exhibiting excellent luminance characteristics when applied to an organic EL element.

As a result of intensive studies in order to achieve the above object, the present inventors have determined that a charge transporting varnish containing a charge transporting material composed of a predetermined aniline derivative, a dopant material composed of a heteropolyacid, and an organosilane compound. Can be fired at a low temperature of less than 200 ° C., the thin film produced under such firing conditions has high flatness and high charge transportability, and the thin film is applied to the hole injection layer. In this case, it was found that an organic EL element capable of realizing excellent luminance characteristics was obtained, and the present invention was completed.

That is, the present invention
1. A charge transporting varnish comprising a charge transporting material comprising an aniline derivative represented by formula (1), a dopant material comprising a heteropolyacid, an organosilane compound, and an organic solvent;

(In formula (1), X ¹ represents —NY ¹ —, —O—, —S—, — (CR ⁷ R ⁸ ) ₁ — or a single bond, and Y ¹ , independently of each other, represents a hydrogen atom. it may be substituted with Z ^1, an alkyl group having 1 to 20 carbon atoms, optionally substituted alkenyl or alkynyl group having 2 to 20 carbon atoms having 2 to 20 carbon atoms or Z ^2,, carbon Represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, and R ¹ to R ⁸ independently of one another are 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, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z ¹ ; Z ² may be substituted with, ants having 6 to 20 carbon atoms Le group or heteroaryl group having a carbon number of ^{2 ~ 20, -NHY 2, -NY} 3 Y 4, -C (O) Y 5, -OY 6, -SY 7, -SO 3 Y 8, -C (O) Represents an OY ⁹ , —OC (O) Y ¹⁰ , —C (O) NHY ¹¹ , or —C (O) NY ¹² Y ¹³ group, and Y ² to Y ¹³ are each independently substituted with 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, or an aryl group having 6 to 20 carbon atoms that may be substituted with Z ^2. 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 Z ³ An optionally substituted aryl group having 6 to 20 carbon atoms or 2 to 2 carbon atoms Represents 0 heteroaryl group, 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, may be substituted with a carboxylic acid group or Z ^3, Represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, and Z ³ represents a halogen atom, nitro group, cyano group, amino group, aldehyde group, hydroxyl group , A thiol group, a sulfonic acid group, or a carboxylic acid group, l represents an integer of 1 to 20, m and n each independently represent an integer of 0 or more, and satisfy 1 ≦ m + n ≦ 20 Provided that when m or n is 0, X ¹ represents —NY ¹ —. )
2. 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 aryl group having 6 to 14 carbon atoms which may be substituted with Z ^2. Wherein R ⁵ and R ⁶ are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , or a carbon atom having 6 to 14 carbon atoms which may be substituted with Z ² . 1 charge transporting varnish which is an aryl group or a diphenylamino group optionally substituted with Z ² ;
3. 1 or 2 charge transporting varnishes wherein the heteropolyacid comprises phosphotungstic acid;
4). The ratio (W _D / W _H ) of the mass (W _D ) of the dopant material to the mass (W _H ) of the charge transporting material satisfies 1.0 ≦ W _D / W _H ≦ 11.0. Any charge transport varnish,
5. The charge transporting varnish according to any one of 1 to 4, wherein the organosilane compound is a dialkoxysilane compound, a trialkoxysilane compound, or a tetraalkoxysilane compound,
6). A charge transporting thin film produced using any one of the charge transporting varnishes 1 to 5,
7). An electronic device having six charge transporting thin films;
8). An organic electroluminescence device having six charge transporting thin films,
9. 8. The organic electroluminescence device according to 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, characterized in that the charge-transporting varnish according to any one of 1 to 5 is applied onto a substrate and baked;
11. 10. A method for producing a charge-transporting thin film, characterized by firing at less than 200 ° C.,
12 And a method for producing an organic electroluminescence device using the charge transporting thin film.

The charge transport varnish of the present invention has a high flatness and a high charge transport property even when fired at a low temperature of less than 200 ° C. When the thin film is applied to a hole injection layer An organic EL element capable of realizing excellent luminance characteristics can be obtained. Therefore, by using the charge transporting varnish of the present invention, it is possible to achieve high yield and low cost by reducing the manufacturing process conditions, or to reduce the weight and size of the device.
In addition, the charge transporting varnish of the present invention can produce a thin film excellent in charge transporting properties with good reproducibility even when using various wet processes capable of forming a film over a large area such as a spin coating method or a slit coating method. It can sufficiently cope with recent progress in the field of organic EL elements.
Furthermore, the thin film obtained from the charge transporting varnish of the present invention can be used as an antistatic film, an anode buffer layer of an organic thin film solar cell, or the like.

Hereinafter, the present invention will be described in more detail.
The charge transporting varnish according to the present invention includes a charge transporting material composed of an aniline derivative represented by the formula (1), a dopant material composed of a heteropolyacid, an organic silane compound, and an organic solvent.
Here, the charge transportability is synonymous with conductivity and is synonymous with hole transportability. The charge transporting substance itself may be charge transporting, or may be charge transporting when used with an electron accepting substance. The charge transporting varnish may itself have a charge transporting property, and the resulting solid film may have a charge transporting property.

In the formula (1), X ¹ represents —NY ¹ —, —O—, —S—, — (CR ⁷ R ⁸ ) ₁ — or a single bond, and when m or n is 0, NY ¹ -is represented.

Y ¹ is independently of each other a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z ¹ , or It represents 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 .

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 Linear or branched having 1 to 20 carbon atoms such as -butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group and n-decyl group Chain alkyl group: cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, bicyclobutyl group, bicyclopentyl group, bicyclohexyl group, bicycloheptyl group, bicyclooctyl And a cyclic alkyl group having 3 to 20 carbon atoms such as a group, a bicyclononyl group and a bicyclodecyl group.

Specific examples of the alkenyl group having 2 to 20 carbon atoms include 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-propenyl group, n- 1-pentenyl group, n-1-decenyl group, n-1-eicocenyl group and the like can be 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, and n-3-butynyl. Group, 1-methyl-2-propynyl group, n-1-pentynyl group, n-2-pentynyl group, n-3-pentynyl 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-pentadecynyl group, n- Examples include 1-eicosinyl group.

Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 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-isothiazolyl group, 5-isothiazolyl group, 2-imidazolyl group, Examples include 4-imidazolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, and the like.

R ⁷ and R ⁸ are 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. Or 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 which may be substituted with Z ² , or carbon Heteroaryl groups of 2 to 20, —NHY ² , —NY ³ Y ⁴ , —C (O) Y ⁵ , —OY ⁶ , —SY ⁷ , —SO ₃ Y ⁸ , —C (O) OY ⁹ , — Represents an OC (O) Y ¹⁰ , —C (O) NHY ¹¹ , or —C (O) NY ¹² Y ¹³ group, and Y ² to Y ¹³ may each independently be substituted with Z ^1. An alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or 2 to 20 represents an alkynyl group, or 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 .

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
In addition, examples of the alkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group of R ⁷ to R ⁸ and Y ² to Y ¹³ are the same as those described above.

Among these, as R ⁷ and R ⁸ , a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may be substituted with Z ¹ is preferable, and a hydrogen atom or a methyl group which may be substituted with Z ¹ Groups are more preferred, both of which are hydrogen atoms.

l represents the number of repeating units of a 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, ˜2 is even more preferred, with 1 being optimal.
When l is 2 or more, the plurality of R ⁷ may be the same as or different from each other, and the plurality of R ⁸ may be the same as or different from each other.

In particular, X ¹ is preferably —NY ¹ — or a single bond. Y ¹ is 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 optionally substituted with Z ¹ , Hydrogen atoms are optimal.

R ¹ to R ⁶ are 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. Or 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 which may be substituted with Z ² , or carbon Heteroaryl groups of 2 to 20, —NHY ² , —NY ³ Y ⁴ , —C (O) Y ⁵ , —OY ⁶ , —SY ⁷ , —SO ₃ Y ⁸ , —C (O) OY ⁹ , — Represents an OC (O) Y ¹⁰ , —C (O) NHY ¹¹ , or —C (O) NY ¹² Y ¹³ group (Y ² to Y ¹³ are as defined above), and these halogen atoms, alkyls A group, an alkenyl group, an alkynyl group, an aryl group and a heteroaryl group Te include those similar to the above.

In particular, in the formula (1), R ¹ to R ⁴ may be substituted with a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹ , or Z ^2. An aryl group having 6 to 14 carbon atoms is preferable, 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 all hydrogen atoms are optimal.
R ⁵ and R ⁶ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms that may be substituted with Z ¹ , or an aryl group having 6 to 14 carbon atoms that may be substituted with Z ² Or a diphenylamino group optionally substituted with Z ² (Y ³ and Y ⁴ are phenyl groups optionally substituted with Z ² —NY ³ Y ⁴ group), preferably a hydrogen atom, a fluorine atom Or a diphenylamino group optionally substituted with a fluorine atom, more preferably a hydrogen atom or a diphenylamino group.

Among these, R ¹ to R ⁴ are hydrogen atoms, fluorine atoms, alkyl groups having 1 to 10 carbon atoms which may be substituted with fluorine atoms, R ⁵ and R ⁶ are hydrogen atoms, fluorine atoms, Diphenylamino group optionally substituted with a fluorine atom, X ¹ is —NY ¹ — or a single bond, and Y ¹ is preferably a hydrogen atom or a combination of methyl groups, and R ¹ to R ⁴ are hydrogen atoms R ⁵ and R ⁶ are simultaneously a hydrogen atom or a diphenylamino group, and X ¹ is more preferably a combination of —NH— or a single bond.

In the formula (1), m and n each independently represent an integer of 0 or more and satisfy 1 ≦ m + n ≦ 20, but considering the balance between the charge transportability of the resulting thin film and the solubility of the aniline derivative. Then, it is preferable to satisfy 2 ≦ m + n ≦ 8, more preferably 2 ≦ m + n ≦ 6, and still more preferably satisfy 2 ≦ m + n ≦ 4.

The alkyl group, alkenyl group and alkynyl group of Y ¹ to Y ¹³ and R ¹ to R ⁸ are 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. Y ¹ to Y ¹³ may be substituted with an acid group or Z ¹ which is 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 ^3. And the aryl group and heteroaryl group of R ¹ to R ⁸ are substituted with a halogen atom, nitro group, cyano group, amino group, aldehyde group, hydroxyl group, thiol group, sulfonic acid group, carboxylic acid group, or Z ³ may be an alkyl group having 1 to 20 carbon atoms, may be substituted with Z ² is an alkenyl group or an alkynyl group having 2 to 20 carbon atoms having 2 to 20 carbon atoms, these radicals Furthermore 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 may be substituted with Z ³ is a carboxylic acid group, (halogen atom, similar to the above Stuff.)

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. ^A phenyl group which may be substituted with ³ is more preferred, and optimally absent (ie, unsubstituted).
Further, the substituent Z ² is a halogen atom or preferably an alkyl group which may having 1 to 20 carbon atoms optionally substituted by Z ^3, halogen atoms or carbon atoms and optionally substituted by Z ³ 1 ~ 4,, It is more preferable that the alkyl group is not present (that is, unsubstituted).
Z ³ is preferably a halogen atom, more preferably fluorine, and optimally not present (that is, unsubstituted).

In Y ¹ to Y ¹³ and R ¹ to R ⁸ , the alkyl group, alkenyl group, and alkynyl group preferably have 10 or less carbon atoms, more preferably 6 or less, and even more preferably 4 or less.
The carbon number of the aryl group and heteroaryl group is preferably 14 or less, more preferably 10 or less, and even more preferably 6 or less.

The molecular weight of the aniline derivative used in the present invention is usually 300 to 5,000, but is preferably 4000 or less, more preferably 3000 or less, and still more preferably 2000 or less, from the viewpoint of enhancing the solubility.
The method for synthesizing the aniline derivative used in the present invention is not particularly limited, but Bulletin of Chemical Society of Japan (1994, Vol. 67 p. 1749-1752), Synthetic Metals (1997, 84, 119-120), Thin Solid Films (2012, 520 (24) 7157-7163), International Publication No. 2008/032617. , International Publication No. 2008-032616, International Publication No. 2008-129947, and the like.

Hereinafter, in the present invention, preferred aniline derivatives are listed, but not limited thereto.

The charge transporting varnish of the present invention contains a heteropolyacid.
A heteropolyacid has a structure in which a heteroatom is located at the center of a molecule, typically represented by a Keggin type represented by formula (A) or a Dawson type chemical structure represented by formula (B), and vanadium ( V), molybdenum (Mo), tungsten (W), and other polyacids such as isopolyacids that are oxygen acids and oxygenates of different elements are condensed. Examples of the oxygen acid of such a different element mainly include silicon (Si), phosphorus (P), and arsenic (As) oxygen acids.

Specific examples of the heteropolyacid include phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, and lintongue molybdic acid. These may be used alone or in combination of two or more. Good. In addition, the heteropolyacid used by this invention is available as a commercial item, and can also be synthesize | combined by a well-known method.
In particular, when the dopant substance is composed of only one type of heteropolyacid, the one type of heteropolyacid is preferably phosphotungstic acid or phosphomolybdic acid, and phosphotungstic acid is most suitable. Further, when the dopant substance is composed of two or more types of heteropolyacids, one of the two or more types of heteropolyacids is preferably phosphotungstic acid or phosphomolybdic acid, and more preferably phosphotungstic acid.
Heteropolyacids are available as commercial products in quantitative analysis such as elemental analysis, even if the number of elements is large or small from the structure represented by the general formula, or appropriate according to known synthesis methods. As long as it is synthesized, 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 phosphomolybdic acid is represented by the chemical formula H ₃ (PMo ₁₂ O ₄₀ ) · nH ₂ O, respectively. In the quantitative 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, Alternatively, as long as it is appropriately synthesized according to a known synthesis method, it can be used in the present invention. In this case, the mass of the heteropolyacid defined in the present invention is not the mass of pure phosphotungstic acid (phosphotungstic acid content) in the synthesized product or commercially available product, but a commercially available form and a known synthesis. In a form that can be isolated by the method, it means the total mass in a state containing hydration water and other impurities.

In the present invention, the heteropolyacid, preferably phosphotungstic acid, is about 1.0 to 11.0, preferably about 1.5 to 10.0, more preferably, with respect to the charge transporting substance 1 in terms of mass ratio. By setting it to about 2.0 to 9.5, more preferably about 2.5 to 9.0, and more preferably about 3.0 to 8.5, high brightness is obtained when used in an organic EL device. A charge transporting thin film can be obtained with good reproducibility.
That is, in such a charge transporting varnish, the ratio of the mass (W _D ) of the heteropolyacid to the mass (W _H ) of the charge transport material is 1.0 ≦ W _D / W _H ≦ 11.0, preferably 1.5 ≦ W _D / W _H ≦ 10.0, more preferably 2.0 ≦ W _D / W _H ≦ 9.5, even more preferably 2.5 ≦ W _D / W _H ≦ 9.0, Preferably, 3.0 ≦ W _D / W _H ≦ 8.5 is satisfied.

For the charge transporting varnish of the present invention, in addition to the above-mentioned aniline derivatives and heteropolyacids, other known charge transporting substances and dopant substances may be used.

The charge transporting varnish of the present invention contains an organosilane compound.
Examples of the organosilane compound include dialkoxysilane compounds, trialkoxysilane compounds, and tetraalkoxysilane compounds, which may be used alone or in combination of two or more.
In particular, as the organosilane compound, a dialkoxysilane compound or a trialkoxysilane compound is preferable, and a trialkoxysilane compound is more preferable.

Examples of the tetraalkoxysilane compound, trialkoxysilane compound, and dialkoxysilane compound include those represented by the formulas (2) to (4).
Si (OR ⁹ ) ₄ (2)
SiR ¹⁰ (OR ⁹ ) ₃ (3)
Si (R ¹⁰ ) ₂ (OR ⁹ ) ₂ (4)

In the formula, R ^{9 s} , independently of each other, may be substituted with Z ⁴ , 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, or Represents 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 ⁵ , and R ¹⁰ may be independently substituted with Z ⁶ , 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, or an aryl group having 6 to 20 carbon atoms which may be substituted with Z ⁷ or 2 carbon atoms Represents ~ 20 heteroaryl groups.

Z ⁴ represents a halogen atom or 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 ⁸ , and Z ⁵ represents a halogen atom or Z ⁸ It represents an optionally substituted 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.

Z ⁶ is a halogen atom, optionally substituted by Z ⁸ , an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms, an epoxycyclohexyl group, a glycidoxy group, a methacryloxy group, an acryloxy group, a ureido Represents a group (—NHCONH ₂ ), thiol group, isocyanate group (—NCO), amino group, —NHY ¹⁴ group, or —NY ¹⁵ Y ¹⁶ group, and Z ⁷ may be substituted with a halogen atom or Z ⁸ Preferably 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 epoxycyclohexyl group, a glycidoxy group, a methacryloxy group, an acryloxy group, a ureido group (—NHCONH ₂ ), Represents a thiol group, an isocyanate group (—NCO), an amino group, —NHY ¹⁴ group, or —NY ¹⁵ Y ¹⁶ group, ¹⁴ to Y ¹⁶ are independently of each other, optionally substituted with Z ⁸ , 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, a carbon number An aryl group having 6 to 20 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms is represented.
Z ⁸ represents a halogen atom, an amino group, a nitro group, a cyano group, or a thiol group.

In formulas (2) to (4), a halogen atom, 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, an aryl group having 6 to 20 carbon atoms, and Examples of the heteroaryl group having 2 to 20 carbon atoms are the same as those described above.
In R ⁹ and R ¹⁰ , the alkyl group, alkenyl group, and alkynyl group preferably have 10 or less carbon atoms, more preferably 6 or less, and still more preferably 4 or less.
The carbon number of the aryl group and heteroaryl group is preferably 14 or less, more preferably 10 or less, and even more preferably 6 or less.

R ⁹ is an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms which may be substituted with Z ⁴ , or aryl having 6 to 20 carbon atoms which may be substituted with Z ^5. groups are preferred, it may be substituted with Z ^4, alkyl group or alkenyl group having 2 to 6 carbon atoms having 1 to 6 carbon atoms or more preferably a phenyl group which may be substituted with Z ^5,, Z ⁴ Is more preferably an alkyl group having 1 to 4 carbon atoms which may be substituted with, or a phenyl group which may be substituted with Z ⁵ , and further a methyl group or an ethyl group which may be substituted with Z ⁴ preferable.
Further, as R ¹⁰ is preferably an aryl group an alkyl group or Z carbon atoms 6 substituted ⁷ to 20, the to 1 carbon atoms which may be ~ 20 substituted with Z ^6, substituted with Z ⁶ carbon atoms which may be have 1-10 alkyl group or more preferably an aryl group which may having 6 to 14 carbon atoms optionally substituted by Z ^7, ~ 1 carbon atoms which may be substituted with Z ⁶ 6, alkyl group, or more preferably more aryl group to 10 carbon atoms 6 optionally substituted by Z ^7, alkyl groups of Z ⁶ is - 1 carbon atoms which may be 4-substituted, the substituents at or Z ^7, More preferred is an optionally substituted phenyl group.
The plurality of R ⁹ may be all the same or different, and the plurality of R ¹⁰ may all be the same or different.

Z ⁴ is preferably a halogen atom or an aryl group having 6 to 20 carbon atoms which may be substituted with Z ⁸ , more preferably a fluorine atom or a phenyl group which may be substituted with Z ^8. Is optimal (ie, is unsubstituted).
Z ⁵ is preferably a halogen atom or an alkyl group having 6 to 20 carbon atoms which may be substituted with Z ⁸ , and is a fluorine atom or having 1 to 10 carbon atoms which may be substituted with Z ⁸ . Alkyl groups are more preferred and optimally absent (ie, unsubstituted).

On the other hand, the Z ^6, a halogen atom, a phenyl group which may be substituted with Z ^8, which may be substituted furanyl group Z ^8, epoxycyclohexyl group, a glycidoxy group, a methacryloxy group, an acryloxy group, a ureido group, thiol group, isocyanate group, an amino group, an optionally substituted phenylamino group Z ⁸ or better diphenylamino group optionally substituted by Z ⁸ are preferably, more preferably a halogen atom, a fluorine atom or absent, (That is, unsubstituted) is even more preferred.
As the Z ^7, halogen atom, Z alkyl group having 1 carbon atoms which may be 20 substituted by ^8, which may be substituted furanyl group Z ^8, epoxycyclohexyl group, a glycidoxy group, a methacryloxy group, acryloxy group, ureido group, a thiol group, isocyanate group, amino group, phenyl amino group optionally substituted by Z ⁸ or better diphenylamino group preferably be substituted with Z ^8,, more preferably a halogen atom, It is even more preferable that the fluorine atom or not exist (that is, unsubstituted).
Z ⁸ is preferably a halogen atom, more preferably a fluorine atom or not (ie, unsubstituted).

Specific examples of the organosilane compound that can be used in the present invention will be given below, but the present invention is not limited thereto.
Specific examples of dialkoxysilane compounds include dimethyldimethoxysilane, dimethyldiethoxysilane, methylethyldimethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, methylpropyldimethoxysilane, methylpropyldiethoxysilane, diisopropyldimethoxysilane, and phenylmethyl. Dimethoxysilane, vinylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, 3-methacryloxy Propylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, γ-aminopropyl Chill diethoxy silane, N- (2- aminoethyl) aminopropyl methyl dimethoxy silane, 3,3,3-trifluoropropyl methyl dimethoxy silane, and the like.

Specific examples of trialkoxysilane compounds include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, Pentyltrimethoxysilane, pentyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxy Silane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, Nyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, γ-methacryloxy Propyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, triethoxy (4- (trifluoromethyl) phenyl) silane, dodecyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, (triethoxysilyl) Cyclohexane, perfluorooctylethyltriethoxysilane, triethoxyfluorosilane, tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, pentafluorophenyltrimethoxysila Pentafluorophenyltriethoxysilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, heptadecafluoro-1,1,2,2-tetrahydrodecyltriethoxysilane, triethoxy-2-thienylsilane, 3- ( And triethoxysilyl) furan.

Specific examples of the tetraalkoxysilane compound include tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane and the like.

Among these, 3,3,3-trifluoropropylmethyldimethoxysilane, triethoxy (4- (trifluoromethyl) phenyl) silane, 3,3,3-trifluoropropyltrimethoxysilane, perfluorooctylethyltriethoxysilane Pentafluorophenyltrimethoxysilane and pentafluorophenyltriethoxysilane are preferred.

The content of the organosilane compound in the charge transporting varnish of the present invention is usually 0. 0 with respect to the total mass of the charge transporting material and the heteropolyacid in consideration of maintaining the high charge transportability of the resulting thin film. The amount is about 1 to 50% by mass, preferably about 0.5 to 40% by mass, more preferably about 0.8 to 30% by mass, and still more preferably 1 to 20% by mass.

As the solvent used in preparing the charge transporting varnish, a highly soluble solvent that can dissolve the charge transporting substance and the dopant substance satisfactorily can be used. Examples of such highly soluble solvents include organic solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, and diethylene glycol monomethyl ether. Can be used. These solvents can be used alone or in combination of two or more, and the amount used can be 5 to 100% by mass with respect to the total solvent used in the varnish.
Note that it is preferable that the charge transporting substance and the dopant substance are either completely dissolved in the solvent or uniformly dispersed.

In addition, the charge transport varnish of the present invention preferably contains other solvents for the purpose of improving wettability to the substrate, adjusting the surface tension, viscosity, boiling point, etc. of the varnish, and adding such solvents. Thus, it becomes easy to prepare a varnish according to the coating method used, the firing temperature, and the like, and a thin film having high flatness and high charge transportability can be obtained with good reproducibility.
Such other solvents are not particularly limited, and examples thereof include cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, triethylene glycol, and the like. Propylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, propylene glycol, hexylene glycol, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol Monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol Bruno methyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diacetone alcohol, .gamma.-butyrolactone, ethyl lactate, n- hexyl acetate, and the like. These solvents can be used singly or in combination of two or more, and the amount used is preferably within the range where no solid precipitates, and is usually 1 for the whole solvent used for varnish. It is ˜95% by mass, preferably 5 to 90% by mass.

The viscosity of the varnish of the present invention is appropriately set according to the thickness of the thin film to be produced and the solid content concentration, but is usually 1 to 50 mPa · s at 25 ° C.
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. In consideration of improving the coatability of the varnish, it is preferably 0.5 to 5.0% by mass, more preferably 1.0 to 3.0% by mass.

A charge transporting thin film can be formed on a base material by applying the charge transporting varnish described above on the base material and baking it.
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 brush coating, an ink jet method, a spray method, and a slit coating method. It is preferable to adjust the viscosity and surface tension of the varnish according to the above.

Further, when the varnish of the present invention is used, the firing atmosphere is not particularly limited, and the film formation surface is uniform not only in the air atmosphere but also in a condition where there is not enough oxygen such as an inert gas atmosphere or a vacuum. In addition, a thin film having high charge transportability can be obtained.

The firing temperature is appropriately set within a range of about 100 to 260 ° C. in consideration of the use of the obtained thin film, the degree of charge transportability imparted to the obtained thin film, and the like. When used as a hole injection layer, it is preferably about 140 to 250 ° C., more preferably about 150 to 230 ° C., but the varnish of the present invention can be fired at a low temperature of less than 200 ° C., particularly 150 to 190 ° C. In this case, two or more stages of temperature changes may be applied for the purpose of expressing higher uniform film forming properties or causing the reaction to proceed on the substrate. The heating may be performed by, for example, a hot plate or an oven. What is necessary is just to perform using an appropriate apparatus.

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

Examples of materials used and methods for producing an OLED element using the charge transporting varnish of the present invention include the following, but are not limited thereto.
The electrode substrate to be used is preferably cleaned in advance by liquid cleaning with a detergent, alcohol, pure water or the like. For example, the anode substrate is subjected to surface treatment such as UV ozone treatment or oxygen-plasma treatment immediately before use. It is preferable. However, when the anode material is mainly composed of an organic material, the surface treatment may not be performed.

The example of the manufacturing method of the OLED element which has a positive hole injection layer which consists of a thin film obtained from the charge transportable varnish of this invention is as follows.
The charge transporting varnish of the present invention is applied on the anode substrate, and baked by the above method to form a hole injection layer on the electrode. This is introduced into a vacuum deposition apparatus, and a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode metal are sequentially deposited to form an OLED element. In order to control the light emitting region, a carrier block layer may be provided between arbitrary layers.
Examples of the anode material include transparent electrodes typified by indium tin oxide (ITO) and indium zinc oxide (IZO), and those subjected to planarization treatment are preferable. Polythiophene derivatives and polyaniline derivatives having high charge transporting properties can also be used.

Examples of the material for forming the hole transport layer include (triphenylamine) dimer derivative (TPD), N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine (α-NPD), [(tri Phenylamine) dimer] triarylamines such as spiro-dimer (Spiro-TAD), 4,4 ′, 4 ″ -tris [3-methylphenyl (phenyl) amino] triphenylamine (m-MTDATA), 4,4 Starburst amines such as', 4 "-tris [1-naphthyl (phenyl) amino] triphenylamine (1-TNATA), 5,5" -bis- {4- [bis (4-methylphenyl) amino] Phenyl} -2,2 ′: 5 ′, 2 ″ -terthiophene (BMA-3T) and the like.

Materials for forming the light emitting layer include tris (8-quinolinolato) aluminum (III) (Alq ₃ ), bis (8-quinolinolato) zinc (II) (Znq ₂ ), bis (2-methyl-8-quinolinolato) ( p-phenylphenolate) aluminum (III) (BAlq), 4,4′-bis (2,2-diphenylvinyl) biphenyl (DPVBi), and the like. The light emitting layer may be formed by co-evaporation.
Examples of the electron transport material include Alq ₃ , BAlq, DPVBi, (2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole) (PBD), triazole derivatives ( TAZ), bathocuproine (BCP), silole derivatives and the like.

Examples of the luminescent dopant include quinacridone, rubrene, coumarin 540, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), tris (2-phenylpyridine) iridium ( III) (Ir (ppy) ₃ ), (1,10-phenanthroline) -tris (4,4,4-trifluoro-1- (2-thienyl) -butane-1,3-dionate) europium (III) ( Eu (TTA) ₃ phen) and the like.

Examples of the material for forming the carrier block layer include PBD, TAZ, and BCP.
Materials 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 ), strontium fluoride (SrF ₂ ), Liq, 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, cesium and the like.

Although the manufacturing method of the PLED element using the charge transportable varnish of this invention is not specifically limited, The following methods are mentioned.
In the preparation of the OLED element, instead of performing the vacuum deposition operation of the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer, the hole transport polymer layer and the light emitting polymer layer are sequentially formed. A PLED element comprising a charge transporting thin film formed by the charge transporting varnish of the invention can be produced.
Specifically, the charge transporting varnish of the present invention is applied on the anode substrate to prepare a hole injection layer by the above method, and a hole transporting polymer layer and a light emitting polymer layer are sequentially formed thereon. Then, a cathode electrode is vapor-deposited to obtain a PLED element.

As the cathode and anode material to be used, the same materials as those used in the production of the OLED element can be used, and the same cleaning treatment and surface treatment can be performed.
The hole transporting polymer layer and the light emitting polymer layer can be formed by adding a solvent to a hole transporting polymer material or a light emitting polymer material, or a material obtained by adding a dopant substance to the hole transporting polymer material. And a method in which the film is uniformly dispersed and applied onto the hole injection layer or the hole transporting polymer layer, and then deposited by evaporation of the solvent.
As the hole transporting polymer material, 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] -endcapped with polysilicon Ruschixoxane, poly [(9,9-didioctylfluoreni -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), poly (2-methoxy-5- (2′-ethylhexoxy) -1,4-phenylenevinylene) (MEH). And polyphenylene vinylene derivatives such as -PPV), polythiophene derivatives such as poly (3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

Examples of the solvent include toluene, xylene, chloroform, and the like. Examples of the dissolution or uniform dispersion method include methods such as stirring, heating and stirring, and ultrasonic dispersion.
The application 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. The application 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.

Hereinafter, although a synthesis example, an Example, and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example. In addition, the apparatus used is as follows.
(1) ¹ H-NMR measurement: High resolution nuclear magnetic resonance apparatus manufactured by Varian (2) Substrate cleaning: Substrate cleaning apparatus manufactured by Choshu Sangyo Co., Ltd. (low pressure plasma method)
(3) Varnish application: Mikasa Co., Ltd. spin coater MS-A100
(4) Film thickness measurement: Fine shape measuring machine Surfcorder ET-4000 manufactured by Kosaka Laboratory Ltd.
(5) Fabrication of EL element: Multi-function vapor deposition system C-E2L1G1-N manufactured by Choshu Industry Co., Ltd.
(6) Measurement of EL element luminance, etc .: IV World measurement system manufactured by Tech World (7) Measurement of EL element life: Organic EL luminance life evaluation system PEL-105S manufactured by Eetchy Co., Ltd.

[1] Synthesis of charge transport material [Synthesis Example 1] Synthesis of aniline derivative

To a mixed suspension of 4,4′-diaminodiphenylamine 10.00 g (50.19 mmol), 4-bromotriphenylamine 34.17 g (105.40 mmol), and xylene (100 g), tetrakis (triphenylphosphine) palladium was added. 0.5799 g (0.5018 mmol) and 10.33 g (105.40 mmol) of tertiary butoxy sodium were added, and the mixture was stirred at 130 ° C. for 14 hours under nitrogen.
Thereafter, the reaction mixture was filtered, and saturated brine was added to the filtrate for separation, and then the solid obtained by distilling off the solvent from the organic layer was recrystallized using 1,4-dioxane. The desired aniline derivative was obtained (yield: 22.37 g, yield: 65%).
¹ H-NMR (CDCl ₃ ): δ 7.83 (S, 2H), 7.68 (S, 1H), 7.26-7.20 (m, 8H), 7.01-6.89 (m, 28H).

[2] Preparation of charge transporting varnish [Example 1-1]
0.206 g of the aniline derivative obtained in Synthesis Example 1 and 0.412 g of phosphotungstic acid (manufactured by Kanto Chemical Co., Inc.) were dissolved in 4.0 g of diethylene glycol monomethyl ether under a nitrogen atmosphere. To the obtained solution, 16.0 g of propylene glycol monomethyl ether was added and stirred, and 0.021 g of 3,3,3-trifluoropropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and phenyltrimethoxysilane were added thereto. 0.041 g (manufactured by Shin-Etsu Chemical Co., Ltd.) was added and further stirred to prepare a charge transporting varnish.

[Examples 1-2 to 1-8]
The amounts of aniline derivative and phosphotungstic acid used were 0.155 g and 0.464 g, 0.124 g and 0.495 g, 0.103 g and 0.515 g, 0.088 g and 0.530 g, respectively. A charge transporting varnish was prepared in the same manner as in Example 1-1 except that 077 g and 0.541 g, 0.069 g and 0.550 g, 0.056 g and 0.562 g were used.

[Example 1-9]
0.309 g of the aniline derivative obtained in Synthesis Example 1 and 0.619 g of phosphotungstic acid were dissolved in 6.0 g of diethylene glycol monomethyl ether under a nitrogen atmosphere. To the obtained solution, 24.0 g of propylene glycol monomethyl ether was added and stirred, 0.028 g of pentafluorophenyltriethoxysilane (manufactured by Scientific Industrial Association Ltd.) was added thereto, and further stirred to obtain a charge transporting varnish. Prepared.

[Examples 1-10 to 16]
The amount of aniline derivative and the amount of phosphotungstic acid used were 0.232 g and 0.696 g, 0.186 g and 0.742 g, 0.155 g and 0.773 g, 0.133 g and 0.795 g, respectively. A charge transporting varnish was prepared in the same manner as in Example 1-9 except that the amount was 116 g and 0.812 g, 0.103 g and 0.825 g, 0.084 g and 0.843 g.

[Example 1-17]
A charge transporting varnish was prepared in the same manner as in Example 1-11 except that the amount of pentafluorophenyltriethoxysilane used was 0.046 g.

[Example 1-18]
0.148 g of N, N′-diphenylbenzidine (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.594 g of phosphotungstic acid are dissolved in 8.0 g of 1,3-dimethyl-2-imidazolidinone under a nitrogen atmosphere. I let you. To the obtained solution, 12.0 g of cyclohexanol and 4.0 g of propylene glycol were added and stirred, and 0.025 g of 3,3,3-trifluoropropyltrimethoxysilane and 0.049 g of phenyltrimethoxysilane were added thereto. The mixture was further stirred to prepare a charge transporting varnish.
N, N′-diphenylbenzidine was recrystallized using 1,4-dioxane and then used after thoroughly drying under reduced pressure.

[Example 1-19]
A charge transporting varnish was prepared in the same manner as in Example 1-18, except that the amount of N, N′-diphenylbenzidine and the amount of phosphotungstic acid used were 0.124 g and 0.619 g.

[Comparative Example 1]
A charge transporting varnish was prepared in the same manner as in Example 1-1 except that 0.021 g of 3,3,3-trifluoropropyltrimethoxysilane and 0.041 g of phenyltrimethoxysilane were not added.

[3] Manufacture and characteristic evaluation of organic EL device [Example 2-1]
The varnish obtained in Example 1-1 was applied to an ITO substrate using a spin coater, then dried at 50 ° C. for 5 minutes, and further baked at 160 ° C. for 15 minutes in an air atmosphere. A uniform thin film of 30 nm was formed. As the ITO substrate, a glass substrate of 25 mm × 25 mm × 0.7 t in which indium tin oxide (ITO) is patterned on the surface with a film thickness of 150 nm is used, and an O ₂ plasma cleaning apparatus (150 W, 30 seconds) before use. To remove impurities on the surface.
Next, N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine (α-) is applied to the ITO substrate on which the thin film has been formed using a vapor deposition apparatus (degree of vacuum: 1.0 × 10 ⁻⁵ Pa). NPD), tris (8-quinolinolato) aluminum (III) (Alq ₃ ), lithium fluoride, and aluminum thin films were sequentially laminated to obtain an organic EL device. At this time, the deposition rate was 0.2 nm / second for α-NPD, Alq ₃ and aluminum, and 0.02 nm / second for lithium fluoride, and the film thicknesses were 30 nm, 40 nm, and 0.2 nm, respectively. The thickness was 5 nm and 120 nm.
In addition, in order to prevent the characteristic deterioration by the influence of oxygen in the air, water, etc., after sealing the organic EL element with the sealing substrate, the characteristic was evaluated. Sealing was performed according to the following procedure.
In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -85 ° C or less, the organic EL element is placed between the sealing substrates, and the sealing substrate is bonded with an adhesive (XNR5516Z-B1 manufactured by Nagase ChemteX Corporation). It was. At this time, a water catching agent (manufactured by Dynic Co., Ltd., HD-071010W-40) was placed in the sealing substrate together with the organic EL element.
The bonded sealing substrate was irradiated with UV light (wavelength: 365 nm, irradiation amount: 6000 mJ / cm ² ), and then annealed at 80 ° C. for 1 hour to cure the adhesive.

[Examples 2-2 to 2-17 and Comparative Example 2]
In the same manner as in Example 2-1, except that the varnish obtained in Examples 1-2 to 1-17 and Comparative Example 1 was used instead of the varnish obtained in Example 1-1, respectively. An organic EL device was produced.

[Examples 2-18 to 2-19]
Instead of the varnish obtained in Example 1-1, the varnish obtained in Examples 1-18 to 1-19 was used, except that the varnish was calcined at 180 ° C. for 15 minutes instead of being calcined at 160 ° C. for 15 minutes. Produced an organic EL device by the same method as in Example 2-1.

The current density and luminance at a driving voltage of 5 V of the organic EL device produced above were measured. The results are shown in Table 1.
In addition, a durability test of the organic EL elements produced in Examples 2-1 to 2-6 was performed. The luminance half-life (initial luminance 5000 cd / m ² ) is shown in Table 2.

As shown in Table 1, when the charge transporting varnish of the present invention containing an organosilane compound in addition to a predetermined aniline derivative and heteropolyacid is used, it is fired at a low temperature of less than 200 ° C. of 160 to 180 ° C. In contrast, an EL device having excellent luminance characteristics could be produced, whereas when a charge transporting varnish containing no organosilane compound (Comparative Example 2) was used, good luminance characteristics could not be realized.

As shown in Table 2, the organic EL device provided with the charge transporting thin film produced in the example showed excellent durability.

Claims

A charge transporting varnish comprising a charge transporting material comprising an aniline derivative represented by the formula (1), a dopant material comprising a heteropolyacid, an organosilane compound, and an organic solvent.

(In the formula (1), X 1 represents —NY 1 —, —O—, —S—, — (CR 7 R 8 ) 1 — or a single bond,
Y 1 is independently of each other a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z 1 , or Represents 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 ;
R 1 to R 8 are 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. Or 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 which may be substituted with Z 2 , or carbon Heteroaryl groups of 2 to 20, —NHY 2 , —NY 3 Y 4 , —C (O) Y 5 , —OY 6 , —SY 7 , —SO 3 Y 8 , —C (O) OY 9 , — Represents an 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, or an alkynyl group having 2 to 20 carbon atoms, which may be substituted with Z 1 , or Represents 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 ;
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 having 6 to 20 carbon atoms which may be substituted with Z 3 Group or a heteroaryl group having 2 to 20 carbon atoms,
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 having 1 to 20 carbon atoms which may be substituted with Z 3 A alkenyl group having 2 to 20 carbon atoms or an alkynyl group having 2 to 20 carbon atoms,
Z 3 represents 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,
l represents an integer of 1 to 20, m and n each independently represents an integer of 0 or more, and satisfies 1 ≦ m + n ≦ 20. However, when m or n is 0, X 1 represents —NY 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 aryl group having 6 to 14 carbon atoms which may be substituted with Z 2. And
R 5 and R 6 are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms that may be substituted with Z 1 , an aryl group having 6 to 14 carbon atoms that may be substituted with Z 2 , 2. The charge transporting varnish according to claim 1, which is a diphenylamino group which may be substituted with Z2.
The charge transporting varnish according to claim 1 or 2, wherein the heteropolyacid contains phosphotungstic acid.
The ratio (W D / W H ) of the mass (W D ) of the dopant material to the mass (W H ) of the charge transport material satisfies 1.0 ≦ W D / W H ≦ 11.0. 4. The charge transporting varnish according to any one of items 1 to 3.
The charge transporting varnish according to any one of claims 1 to 4, wherein the organic silane compound is a dialkoxysilane compound, a trialkoxysilane compound, or a tetraalkoxysilane compound.
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 electroluminescence device comprising the charge transporting thin film according to claim 6.
The organic electroluminescence device according to claim 8, wherein 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 onto a base material and baking.
The method for producing a charge transporting thin film according to claim 10, wherein baking is performed at less than 200 ° C.
A method for producing an organic electroluminescence device using the charge transporting thin film according to claim 6.