JP2011202124A - Composition for charge transporting film, organic electroluminescence element, organic el display and organic el lighting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for a charge transporting film, which can form a film uniformly in formation of an organic thin film by a wet film-forming method, has excellent storage stability, and does not cause industrial problems, and to provide an electroluminescence element having an organic layer formed by a wet film-forming method, which has a uniform light emitting surface and a low voltage, causes no short circuit or dark spots and has a long driving life.SOLUTION: The composition for a charge transporting film includes a polymer having a dissociative group, an electron-accepting compound and an organic solvent, in which the content of large aggregates having a particle size (2R) of a micron order is low when observed by scanning microscopic light scattering.

Description

The present invention relates to a charge transport film composition used for forming an organic layer or the like of an organic electroluminescence device.
The present invention also relates to an organic electroluminescent device having an organic layer formed of a composition for a charge transport film.

In recent years, an electroluminescent element (organic electroluminescent element) using an organic thin film has been developed. Examples of the method for forming the organic thin film in the organic electroluminescence device include a vacuum deposition method and a wet film formation method.
Among these, since the vacuum deposition method can be laminated, it has an advantage that the charge injection from the anode and / or the cathode can be improved and the exciton light-emitting layer can be easily contained.

On the other hand, the wet film formation method does not require a vacuum process, is easy to increase in area, and can be easily mixed with a plurality of materials having various functions in one layer (coating liquid). There is.
As an example of forming an organic layer by a wet film forming method, Patent Documents 1 and 2 disclose an invention of an organic electroluminescent element in which a hole injection layer and a light emitting layer are formed by a wet film forming method. However, when an organic thin film is formed by a wet film-forming method using a conventional composition, the film may not be formed uniformly. Therefore, an organic electroluminescence device having an organic layer formed by a wet film formation method using the composition causes unevenness on the light emitting surface, short circuit, or dark spots due to charge concentration. There was a problem. In addition, due to a decrease in the storage stability of the composition used in the wet film formation method, industrial problems such as a decrease in yield and a short pot life may occur.

JP 2007-110093 A JP 2007-335852 A

In view of the above circumstances, the inventors of the present invention can form a uniform film when an organic thin film is formed by a wet film formation method, and the charge is excellent in storage stability of the composition and causes no industrial problems. It is an object to provide a composition for a transport film.
It is another object of the present invention to provide an organic electroluminescent device that does not cause a short circuit or a dark spot in an organic electroluminescent device having an organic layer formed by a wet film formation method.

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by static light scattering measurement as long as the composition satisfies the following conditions, and the present invention has been achieved.
That is, the gist of the present invention is as follows.
The present invention is a composition for a charge transport film comprising a dissociative polymer, an electron accepting compound and an organic solvent, and in a static light scattering measurement, when the scattering angle (2θ) is 8 °,
It exists in the composition for charge transport films characterized by satisfy | filling following formula (1) (Hereinafter, it may be called "the composition for charge transport films of this invention.").

I _ms / I _m0 ≦ 35 (1)
(In formula (1), I _ms represents the corrected scattering intensity of the charge transport film composition, and is a value calculated as I _ms = I _s × 100 / T _s .
I _m0 represents the corrected scattering intensity of the organic solvent contained in the charge transport film composition, and is a value calculated as I _m0 = I ₀ × 100 / T ₀ .

Also, I _s by a static light scattering measurement, the scattering intensity of the charge transport coating composition,
I ₀ is the scattering intensity of the organic solvent contained in the composition for a charge transport film by static light scattering measurement,
T _s is the transmittance (%) of the charge transport film composition at the light scattering measurement wavelength, measured by transmittance.
T ₀ is the transmittance (%) of the organic solvent contained in the composition for charge transport film at the light scattering measurement wavelength by transmittance measurement,
Represents. )
Moreover, it exists in an organic electroluminescent element, the organic electroluminescent display containing this, and organic electroluminescent illumination.

The composition for a charge transport film of the present invention has high storage stability without generation of aggregates due to various solutes such as a polymer having a dissociable group or an electron-accepting compound, and an increase over time. In the case of forming an organic layer by a film forming method, it is possible to form a film uniformly, and there is no disadvantage from an industrial viewpoint, for example, it is filtered uniformly without clogging.
Moreover, the organic electroluminescent element which has the organic layer formed by the wet film-forming method using the composition for charge transport films of this invention does not produce a short circuit or a dark spot. For this reason, the organic electroluminescent element of the present invention has a long driving life.

Therefore, the organic electroluminescent device of the present invention is a light source (for example, a light source of a copying machine, a liquid crystal display or an instrument back) utilizing characteristics of a flat panel display (for example, for OA computers or wall-mounted televisions) or a surface light emitter. The technical value is high when applied to light sources), display boards, and marker lamps.
The charge transport film composition of the present invention has high storage stability, and can form a uniform film when forming an organic layer by a wet film formation method, and does not cause a disadvantage from an industrial viewpoint. Therefore, it can be effectively used not only for organic electroluminescent elements but also for organic devices such as electrophotographic photosensitive members, photoelectric conversion elements, organic solar cells, and organic rectifying elements.

It is sectional drawing which shows typically an example of the structure of the organic electroluminescent element of this invention.

Hereinafter, embodiments of the composition for a charge transport film, the organic electroluminescence device, the organic EL display and the organic EL lighting of the present invention will be described in detail. However, the description of the constituent elements described below is the embodiment of the present invention. It is an example (representative example), and the present invention is not specified in these contents unless it exceeds the gist.
<Composition for charge transport film>
The charge transport film composition of the present invention is a charge transport film composition containing a dissociative polymer, an electron accepting compound and an organic solvent, and has a scattering angle (2θ) of 8 in static light scattering measurement. When it is, it is a composition for charge transport films satisfying the following formula (1).

I _ms / I _m0 ≦ 35 (1)
(In formula (1), Ims represents the corrected scattering intensity of the composition for a charge transport film, and is a value calculated as I _ms = I _s × 100 / T _s .
I _m0 represents the corrected scattering intensity of the organic solvent contained in the charge transport film composition, and I _m0 = I
It is a value calculated as ₀ × 100 / T ₀ .

Also, I _s by a static light scattering measurement, the scattering intensity of the charge transport coating composition,
I ₀ is the scattering intensity of the organic solvent contained in the composition for a charge transport film by static light scattering measurement,
T _s is the transmittance (%) of the charge transport film composition at the light scattering measurement wavelength, measured by transmittance.
T ₀ is the transmittance (%) of the organic solvent contained in the composition for charge transport film at the light scattering measurement wavelength by transmittance measurement,
Represents. )
In the light scattering measurement, a measurement method is appropriately selected depending on the transmittance of the cell filled with the charge transport film composition. When measuring by static light scattering, the transmittance is not particularly limited, but the transmittance of a laser having a wavelength of usually 550 to 800 nm, preferably 600 to 700 nm, particularly preferably a He—Ne laser (wavelength 633 nm). Usually, it is 5% or more, preferably 8% or more, more preferably 10% or more.

If the transmittance is too low, the scattering intensity decreases and noise increases, which may prevent accurate measurement. The upper limit of the transmittance is not particularly limited.
[Static light scattering measurement]
The static light scattering measurement in the present invention means that the corrected scattering intensity is calculated by obtaining the scattering intensity and transmittance.

Although the scattering intensity can be obtained by performing the static light scattering measurement, in the present invention, the corrected scattering intensity is obtained from the scattering intensity and the transmittance by further measuring the transmittance.
(1. Measurement method)
In order to perform the static light scattering measurement, for example, a polymer film dynamics analyzer DYNA-3000 (manufactured by Otsuka Electronics Co., Ltd.) is used.

Charge transport film composition (hereinafter referred to as “measurement sample”) containing a dissociative polymer, an electron accepting compound and an organic solvent, and an organic solvent contained in the charge transport film composition (hereinafter referred to as “measurement”) For each of the “solvents”, the scattering intensity with respect to the scattering angle (2θ) of each of the measurement sample and the measurement solvent is obtained by measuring with the polymer film dynamics analyzer. The scattering intensity of the measurement sample is I _s , and the scattering intensity of the measurement solvent is I ₀ . The measurement conditions are Vv scattering conditions. For the measurement, a He—Ne laser (wavelength 633 nm) is used.

Here, when the scattering angle (2θ) is 8 °, the scattering intensity Is of the measurement sample is Is (8 °), and the scattering intensity I ₀ of the measurement solvent is I ₀ (8 °).
In order to measure the transmittance, for example, a fiber multichannel spectrometer USB2000 (manufactured by Ocean Optics) is used.
The transmittance of each of the measurement sample and the measurement solvent can be obtained by measuring each of the measurement sample and the measurement solvent with the fiber multichannel spectrometer. Using the obtained transmittance, the scattering intensity is corrected for absorption. The transmittance of the measurement sample is T _s (%), and the transmittance of the measurement solvent is T ₀ (%). Here, the transmittance is measured at the light wavelength (hereinafter referred to as “light scattering measurement wavelength”) used in measuring the scattering intensity. In this case, the transmittance is measured using a He—Ne laser (wavelength 633 nm). .

A corrected scattering intensity is calculated from the transmittance and scattering intensity obtained above. When the scattering angle (2θ) is 8 °, each of the scattering intensity of the measurement sample and the scattering intensity of the measurement solvent is applied to the following formula, thereby correcting the corrected scattering intensity I _ms of the measurement sample and the measurement solvent. The corrected scattering intensity I _m0 is calculated. That is, for the above I _s (8 °), the following formula (1-1
) To calculate the corrected scattering intensity. Further, the following formula (1-2) is used for I ₀ (8 °).
The corrected scattering intensity is calculated.

I _ms = I _s × 100 / T _s (1-1)
I _m0 = I ₀ × 100 / T ₀ (1-2)
Here, the _{I ms} obtained from _{I s (8 °) I ms} (8 °), the _{I m0} obtained from _{I 0 (8 °) I m0} (8 °), and to.
In the present invention, in the static light scattering measurement, when the scattering angle (2θ) is 8 °, satisfying the following formula (1) means satisfying the following formula (2-1).

I _ms / I _m0 ≦ 35 (1)
I _ms (8 °) / I _m0 (8 °) ≦ 35 (2-1)
In the present invention, I _ms / I _m0 is 35 or less, preferably 25 or less, more preferably 10 or less, particularly preferably 5 or less, and most preferably 3 or less. I _ms / I _m0 is usually 1 or more, but may be 0 or more and less than 1 due to fluctuations in the measurement sample, measurement system temperature, laser intensity, or the like.

Further, when the value of I _ms / I _m0 is within the above range, the composition has good storage stability, and when an organic layer is formed by a wet film forming method, it is easy to form a film, and further filtration is performed. When this is done, clogging is less likely to occur, and disadvantages are less likely to occur from an industrial point of view.
In order to obtain this effect, it is preferable to satisfy the above formula (1) particularly when the scattering angle (2θ) is 8 ° and 15 °. The calculation method of I _ms / I _m0 when the scattering angle (2θ) is 15 ° is the same as that when the scattering angle (2θ) is 8 °.

Furthermore, in the present invention, when the scattering angle (2θ) is 8 ° ≦ 2θ ≦ 15 °, I _ms / I _m0 always satisfies the above formula (1), and the filterability is further good. This is preferable in that the storage stability of the composition is hardly lowered.
The composition for charge transport films always satisfies the above formula (1) when the scattering angle (2θ) is 8 ° ≦ 2θ ≦ 15 °. The scattering angle (2θ) is 8 ° ≦ 2θ ≦ 15 °. This means that when the corrected scattering intensity is obtained in the same manner as described above, I _ms / I _m0 ≦ 35.

Note that the measuring device used for specifying the present invention is not limited to the above measuring device as long as the same measurement as described above is possible, and other measuring devices may be used. Is preferably used.
(2. Reason)
In the static light scattering measurement, the reason why the effect of the present invention can be obtained by satisfying the formula (1) when the scattering angle (2θ) is 8 ° is considered as follows.

In the small-angle scattering region, according to the Mie scattering theory, the larger the particle size, the larger the scattering intensity tends to be exhibited.
For example, when a particle is irradiated with a laser having an oscillation wavelength in the visible light wavelength region, specifically, a He—Ne laser (wavelength 633 nm) used in static light scattering measurement, the particle size is a micron order particle. If present, there is a tendency to show a large scattering intensity.

Therefore, by measuring in the small angle scattering region, the ratio including aggregates whose particle size is on the order of microns can be confirmed.
In the present invention, the small angle scattering region is a Guinier region (qR <1).
Further, the scattering angle (2θ) to be measured is estimated from the particle radius (R) using qR <1. Here, the wave number q is represented by the following formula (3).

q = (4πn / λ) × sin θ (3)
(In formula (3), n represents the refractive index of the solvent, λ represents the wavelength (nm) of the incident light, and θ represents a value half the scattering angle (2θ).)
Using the above formula (3), the region of the scattering angle (2θ) where a large scattering intensity is observed when the particle size (2R) is 1 μm is estimated. When the particle diameter (2R) is 1 μm, q <1 / R = 2 μm ⁻¹ , where q = 2 μm ⁻¹ is simply set. If the scattering angle (2θ) is simply calculated using this and the above equation (3) (for example, n = 1.5, λ = 633 nm), the scattering angle (2θ) is calculated as 8 °. That is, a large aggregate having a particle size of the order of microns exhibits a large scattering intensity when the scattering angle (2θ) is 8 ° or less.

In the present invention, the scattering intensity when the scattering angle (2θ) is 8 ° is measured by static light scattering measurement, and evaluation is performed using the obtained scattering intensity. That is, when the scattering angle (2θ) is 8 °, a composition having a small scattering intensity has a small proportion of aggregates having a particle size (2R) in the micron order.
More specifically, since the aggregate is not contained only in the organic solvent contained in the composition, when the scattering angle (2θ) is 8 °, the corrected scattering intensity of the composition is the organic solvent (composition If it is larger than the corrected scattering intensity of the organic solvent contained in the product, it means that the ratio of large aggregates having a particle size (2R) in the order of microns contained in the composition is large. . In addition, when the corrected scattering intensity of the composition is approximately the same as the corrected scattering intensity of the organic solvent, the ratio of the large aggregates having a particle size (2R) in the order of microns contained in the composition Means small.

Similarly, when the particle size (2R) is 0.5 μm, the scattering angle (2θ) is calculated to be 15 °. That is, when incident light having a wavelength of 633 nm is used and the scattering angle (2θ) is 15 ° and the scattering intensity is large, the ratio of containing aggregates having a particle size (2R) larger than 0.5 μm Means big.
From the above, when I _ms / I _m0 when the scattering angle (2θ) is 8 ° is 10 or less, the ratio of containing large aggregates having a particle size of micron order contained in the composition is small. Means. In other words, the small proportion of large aggregates having a particle size on the order of microns brings about the effect of the present invention of improving storage stability.

[Dissociable polymer]
The composition for a charge transport film of the present invention contains a polymer having a dissociable group (hereinafter sometimes referred to as “dissociable polymer”).
(1. About molecular weight)
When the layer containing the dissociative polymer is formed by a wet film forming method, the weight average molecular weight is usually 3,000,000 or less, preferably 1 in terms of solubility, film forming property, and heat resistance. It is 1,000,000 or less, more preferably 500,000 or less, and usually 1,000 or more, preferably 2,500 or more, more preferably 5,000 or more.

The number average molecular weight (Mn) of the dissociative polymer in the present invention is usually 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, and usually 500 or more, preferably 1,500 or more, more preferably 3,000 or more.
Furthermore, the dispersibility (Mw / Mn) of the dissociative polymer in the present invention is usually 10 or less, preferably 2.5 or less, more preferably 2.0 or less, preferably 1.0 or more, more preferably 1.1 or more, particularly preferably 1.2 or more.

Within the above range, purification is easy, and the dissociative polymer has good solubility in organic solvents and charge transportability, which is preferable.
The weight average molecular weight (and number average molecular weight) in the present invention is determined by SEC (size exclusion chromatography) measurement. In SEC measurement, the elution time is shorter for higher molecular weight components and the elution time is longer for lower molecular weight components, but using the calibration curve calculated from the elution time of polystyrene (standard sample) with a known molecular weight, the elution time of the sample is changed to the molecular weight. By converting, the weight average molecular weight (and number average molecular weight) is calculated.

(About dissociable groups)
The dissociable group is a group that is soluble in a solvent, and represents a group that is thermally dissociated at 70 ° C. or higher from a bonded group (for example, a hydrocarbon ring). In addition, the dissociation of the dissociable group reduces the solubility of the polymer in the solvent.
However, a reaction in which other atoms are bonded after dissociation, for example, a group dissociated by hydrolysis is excluded. A group dissociating by hydrolysis has an active proton in the molecule after dissociation. If this active proton is present in the device, the device characteristics may be affected.

Such a dissociable group is preferably bonded to a hydrocarbon ring, and the hydrocarbon ring is preferably condensed to an aromatic hydrocarbon ring having no polar group. The group is thermally dissociated by a reverse Diels-Alder reaction. More preferably.
The temperature at which heat dissociates is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, preferably 300 ° C. or lower, more preferably 240 ° C. or lower.

Within the above range, the synthesis of the polymer is easy, and the compound does not easily decompose during film formation.
In particular, a group having a three-dimensional structure that suppresses intermolecular stacking is preferable because it is excellent in solubility. An example of a reaction in which a dissociable group dissociates from a compound is shown below.

In the case of the above reaction formula, the dissociable group is a portion surrounded by a round frame having the structure shown below.

Examples of such dissociable group dissociation include, for example, desulfinylacetamide (see JACS, V124, No. 30, 2002, 8813), deolefination, dealcoholization, dealkylation (H. Kwart and K. King, Department). of Chemistry, Universality of Delaware, New York, Delaware 19771, p415-447 (1967), O. Diels and
K. Alder, Ber. 62, 554 (1929) and M.M. C. Kloetzel, Org. Reactions, 4, 6 (1948)), 1,3-dioxole (see ND Field, J. Am. Chem. Soc., 83, 3504 (1961)), dediene (R. Huisgen, M.). Seidel, G. Wallbilich, and H. Knupfer, Tetrahedron, 17, 3 (1962)), deisoxazole (R. Huisgen and M, Christi, Angew. Chem. Inter. Ed. Engl., 5, 456 (19). )), Detriazole (see R. Kreher and J. Sebert, Z. Natureforach, 20B, 75 (1965)) and the like.

Among these, it is particularly preferable that the hydrocarbon ring to which the dissociable group is bonded is an etheno group or a ring containing an ethano group because the dissociable group is more stable and easy to synthesize.
The etheno group or ethano group is preferably contained in a hydrocarbon ring, and the hydrocarbon ring is preferably a 6-membered ring.
The dissociative polymer in the present invention preferably contains a partial structure represented by the following chemical formula (U1) or (U2) in the repeating unit as a repeating unit having a partial structure to which a dissociable group is bonded. In this case, the content of the repeating unit (U1) or (U2) in the polymer chain is preferably 10 mol% or more, more preferably 30 mol% or more.
(Repeating unit)

(When the polymer has a structure represented by the formula (U1) or the formula (U2) in the main chain repeating unit, the formula (U1) or the formula (U2) represents a divalent group.
When the polymer has a structure represented by the formula (U1) or the formula (U2) in the side chain, the formula (U1) or the formula (U2) represents a monovalent group, and is represented by X ² and X ⁴ The terminal of the group to be formed is a hydrogen atom.

In formula (U1):
X ¹ and X ² are each independently a divalent aromatic hydrocarbon ring group having 6 to 50 carbon atoms that may have a substituent, or 5 carbon atoms that may have a substituent. Represents a divalent aromatic heterocyclic group of 50 or less.
Ring A ⁰ represents an aromatic ring to which a dissociable group is bonded, and may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. However, since the electrochemical stability is excellent, the charge is locally An aromatic hydrocarbon ring is preferable because it is difficult to be present. The aromatic ring may have a substituent, and the substituents may form a ring directly or via a divalent linking group.

S ¹ , S ² , R ^{41 to} R ⁴⁶ are each independently a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an aromatic hydrocarbon ring group which may have a substituent, An aromatic heterocyclic group which may have a substituent, an aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy which may have a substituent A group, an acyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, an acyloxy group which may have a substituent, It represents an arylamino group which may have a substituent, a heteroarylamino group which may have a substituent, or an acylamino group which may have a substituent.

In the formula (U2),
S ^{11 to} S ¹⁴ , R ^{51 to} R ⁵⁶ , X ³ , X ⁴ and ring B ⁰ are each independently as S ¹ , S ² , R ^{41 to} R ⁴⁶ , X ¹ , X ² and ring A ^0. It is the same as that shown.
n ¹ ~n ⁴ each independently represent an integer of 0 to 5. )
When the rings A ⁰ and B ⁰ are aromatic hydrocarbon rings, the number of carbon atoms in the aromatic hydrocarbon ring is usually 6 or more. Moreover, it is 40 or less normally, Preferably it is 30 or less, More preferably, it is 20 or less. Further, when the rings A ⁰ and B ⁰ are aromatic heterocycles, the number of nuclear carbons of the aromatic heterocycle is usually 3 or more, preferably 4 or more, more preferably 5 or more. Moreover, it is 50 or less normally, Preferably it is 30 or less, More preferably, it is 20 or less.

Examples of the aromatic hydrocarbon ring include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzopyrene ring, chrysene ring, benzochrysene ring, triphenylene ring, fluoranthene ring, and fluorene ring. Is mentioned.
Among the above, it is preferable that the ring A ⁰ and the ring B ⁰ are each independently selected from the group consisting of a benzene ring, a naphthalene ring, an anthracene ring, and a tetracene ring.

  Examples of the aromatic heterocycle include furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolo Pyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, quinoline ring, isoquinoline ring Quinoxaline ring, perimidine ring, quinazoline ring, quinazolinone ring, and the like.

Further, in the chemical formulas (U1) and (U2), the ring A ⁰ and the ring B ⁰ are the same or different two or more kinds of ring structural units of 1 or more and 10 or less, directly, or an oxygen atom, a nitrogen atom, a sulfur atom,
A structure in which a chain group which may contain a hetero atom having 1 to 20 nuclear carbon atoms and a divalent linking group having one or more divalent groups selected from aliphatic groups having 1 to 20 carbon atoms is used. It is also possible. The ring structural unit to be connected may be the same or different aromatic hydrocarbon ring or aromatic heterocycle as the above aromatic hydrocarbon ring or aromatic heterocycle. Moreover, these aromatic hydrocarbon rings and aromatic heterocycles may have a substituent.

Examples of the substituent for ring A ⁰ or ring B ⁰ include a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, an n-butyl group, an isobutyl group, and a tert-butyl group having 1 to 10 carbon atoms. Linear or branched alkyl group; alkenyl group having 1 to 8 carbon atoms such as vinyl group, allyl group and 1-butenyl group; alkynyl group having 1 to 8 carbon atoms such as ethynyl group and propargyl group; benzyl group and the like An aralkyl group having 2 to 8 carbon atoms; an arylamino group such as a phenylamino group, a diphenylamino group and a ditolylamino group; a heteroarylamino group such as a pyridylamino group, a thienylamino group and a dithienylamino group; an acetylamino group and a benzoyl group An acylamino group such as an amino group; an alkoxy group having 1 to 8 carbon atoms such as a methoxy group, an ethoxy group, or a butoxy group; An acyloxyl group having 1 to 15 carbon atoms, such as an yloxyl group, a methylcarbonyloxyl group, an ethylcarbonyloxyl group, a hydroxycarbonylmethylcarbonyloxyl group, a hydroxycarbonylethylcarbonyloxyl group, a hydroxyphenylcarbonyloxyl group; a phenyloxy group , 1-naphthyloxy group, 2-naphthyloxy group and the like, aryloxyl groups having 10 to 20 carbon atoms, and the like. These substituents may be directly to each other, or —O—, —S—,>CO,> SO ₂ , — (C _x H _2x ) —, —O— (C _y H _2y ) —, substituted or unsubstituted. May be bonded via a divalent linking group such as an alkylidene group having 2 to 20 carbon atoms, an alkylene group having 2 to 20 carbon atoms which may have a substituent, and may form a cyclic structure. . Said x and y represent the integer of 1-20, respectively.

As for these substituents, only one type, or two or more types may be substituted in any combination, or two or more may be substituted with ring A ⁰ or ring B ⁰ .
S ¹ , S ² , R ^{41 to} R ⁴⁶ , S ^{11 to} S ¹⁴ , and R ^{51 to} R ⁵⁶ in the chemical formula (U1) and the chemical formula (U2) are each independently a hydrogen atom;
Hydroxyl group;
The number of carbon atoms which may have a substituent such as a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, an n-butyl group, an isobutyl group and a tert-butyl group is usually 1 or more and usually 50 or less. Preferably 10 or less linear or branched alkyl groups;
An aromatic hydrocarbon ring group having usually 5 to 50 nuclear carbon atoms which may have a substituent; an aromatic heterocyclic group having 5 to 40 nucleus carbon atoms which may have a substituent;
An aralkyl group having usually 6 or more, preferably 7 or more, usually 50 or less, preferably 8 or less, optionally having a substituent such as a benzyl group;
An alkoxy group having 1 or more, usually 50 or less, preferably 8 or less carbon atoms which may have a substituent such as a methoxy group, an ethoxy group or a butoxy group;
An aryloxy group having usually 5 or more, preferably 6 or more, and usually 50 or less, preferably 15 or less nuclear carbon atoms which may have a substituent such as phenyloxy group, 1-naphthyloxy group, 2-naphthyloxy group, etc. Group;
An acyl group having usually 2 or more and 50 or less nuclear carbon atoms which may have a substituent;
An alkenyl group having 1 to 8 carbon atoms which may have a substituent such as vinyl group, allyl group or 1-butenyl group; carbon which may have a substituent such as ethynyl group or propargyl group An alkynyl group having a number of usually 1 to 8,
The number of nuclear carbon atoms which may have a substituent such as acryloyloxyl group, methylcarbonyloxyl group, ethylcarbonyloxyl group, hydroxycarbonylmethylcarbonyloxyl group, hydroxycarbonylethylcarbonyloxyl group, hydroxyphenylcarbonyloxyl group is usually 2 Or more, usually 50 or less, preferably 15 or less acyloxy group;
An arylamino group having usually 6 or more and 50 or less nuclear carbon atoms, which may have a substituent such as a phenylamino group, a diphenylamino group or a ditolylamino group;
A heteroarylamino group having usually 5 or more and 50 or less nuclear carbon atoms which may have a substituent such as a pyridylamino group, a thienylamino group, a dithienylamino group;
Or the acylamino group whose carbon number which may have substituents, such as an acetylamino group and a benzoylamino group, is 2-50 normally.

Such a dissociable group can prevent stacking between molecules due to its bulky molecular structure before heat treatment, or the polymer can have good solubility in an organic coating solvent. . Further, since the dissociable group is dissociated from the polymer by the heat treatment, the solubility of the compound after heating in the solvent can be remarkably suppressed, and the organic layer containing the compound is imparted with an organic solvent coating resistance. I can do it. Therefore, it becomes easy to further form an organic thin film on the organic layer formed using the dissociable polymer in the present invention by a wet film forming method.
(Regarding formula (4))
The dissociative polymer contained in the charge transport film composition of the present invention is preferably a polymer containing a repeating unit represented by the following formula (4) from the viewpoint of excellent hole transport ability.

(In the formula, m represents an integer of 0 to 3,
Ar ³¹ and Ar ³² each independently represent a direct bond, a divalent aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar ^{33 to} Ar ³⁵ each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ³³ and Ar ³⁵ represent a monovalent group, and Ar ³⁴ represents a divalent group.

However, Ar ³¹ and Ar ³² are not simultaneously a direct bond. )
(About Ar ^{31 to} Ar ³⁵ )
In formula (4), Ar ³¹ and Ar ³² are each independently a direct bond, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocycle which may have a substituent. Ar ^{33 to} Ar ³⁵ each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.

Examples of the aromatic hydrocarbon group which may have a substituent include, for example, a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, and acenaphthene. Examples thereof include a group derived from a 6-membered monocyclic ring or a 2-5 condensed ring, such as a ring, a fluoranthene ring, and a fluorene ring.
Examples of the aromatic heterocyclic group which may have a substituent include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, and a carbazole ring. , Pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine Ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, sinoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring, etc. ring It can be mentioned groups derived from 2-4 fused rings.

Ar ^{31 to} Ar ³⁵ are each independently from a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, a thiophene ring, a pyridine ring, and a fluorene ring from the viewpoint of solubility in a solvent and heat resistance. A group derived from a ring selected from the group consisting of
In addition, as Ar ^{31 to} Ar ³⁵ , a group in which one or two or more rings selected from the above group are directly bonded or connected by a —CH═CH— group is preferable, and a biphenyl group and a terphenyl-derived group are Further preferred.

Examples of the substituent that the aromatic hydrocarbon group that may have a substituent and the aromatic heterocyclic group that may have a substituent may have the following (substituent group Z): Group described in the above.
(Substituent group Z)
Preferably an alkyl group having 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, such as a methyl group or an ethyl group;
An alkenyl group having preferably 2 to 24 carbon atoms, more preferably 2 to 12 carbon atoms, such as a vinyl group;
An alkynyl group having preferably 2 to 24 carbon atoms, more preferably 2 to 12 carbon atoms, such as an ethynyl group;
Preferably an alkoxy group having 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, such as a methoxy group and an ethoxy group;
Preferably an aryloxy group having 4 to 36 carbon atoms, more preferably 5 to 24 carbon atoms, such as a phenoxy group, a naphthoxy group, and a pyridyloxy group;
An alkoxycarbonyl group having preferably 2 to 24 carbon atoms, more preferably 2 to 12 carbon atoms, such as a methoxycarbonyl group and an ethoxycarbonyl group;
A dialkylamino group having preferably 2 to 24 carbon atoms, more preferably 2 to 12 carbon atoms, such as a dimethylamino group and a diethylamino group;
A diarylamino group having preferably 10 to 36 carbon atoms, more preferably 12 to 24 carbon atoms, such as a diphenylamino group, a ditolylamino group, and an N-carbazolyl group;
An arylalkylamino group having preferably 6 to 36 carbon atoms, more preferably 7 to 24 carbon atoms, such as a phenylmethylamino group;
An acyl group having preferably 2 to 24 carbon atoms, preferably 2 to 12 carbon atoms, such as an acetyl group and a benzoyl group;
Halogen atoms such as fluorine atoms and chlorine atoms;
A haloalkyl group having preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, such as a trifluoromethyl group;
Preferably an alkylthio group having 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group;
A phenylthio group, a naphthylthio group, a pyridylthio group and the like, preferably an arylthio group having 4 to 36 carbon atoms, more preferably 5 to 24 carbon atoms;
A silyl group having preferably 2 to 36 carbon atoms, more preferably 3 to 24 carbon atoms, such as a trimethylsilyl group and a triphenylsilyl group;
A siloxy group having preferably 2 to 36 carbon atoms, more preferably 3 to 24 carbon atoms, such as a trimethylsiloxy group and a triphenylsiloxy group;
A cyano group;
A phenyl group, a naphthyl group, etc., preferably 6 to 36 carbon atoms, more preferably 6 to 2 carbon atoms.
4 aromatic hydrocarbon radicals;
An aromatic heterocyclic group having preferably 3 to 36 carbon atoms, more preferably 4 to 24 carbon atoms, such as a thienyl group and a pyridyl group.

Each of the above substituents may further have a substituent, and examples thereof include the groups exemplified in the substituent group Z.
The molecular weight of the substituent that the aromatic hydrocarbon group and the aromatic heterocyclic group in Ar ^{31 to} Ar ³⁵ may have is preferably 500 or less, more preferably 250 or less, including the substituted group.

From the viewpoint of solubility in a solvent, the aromatic hydrocarbon group and the aromatic heterocyclic group that may be possessed by Ar ^{31 to} Ar ³⁵ are each independently an alkyl group having 1 to 12 carbon atoms and A C1-C12 alkoxy group is preferable.
In addition, when m is 2 or more, the repeating unit represented by the formula (4) has two or more Ar ³⁴ and Ar ³⁵ . In this case, Ar ³⁴ and Ar ³⁵ may be the same or different. Further, Ar ³⁴ and Ar ³⁵ may be bonded to each other directly or via a linking group to form a cyclic structure.

(About 2-2.m)
M in Formula (4) represents an integer of 0 or more and 3 or less.
It is preferable that m is 0 from the viewpoint that the dissociative polymer has improved solubility in an organic solvent and film formability.
Further, m is preferably 1 or more and 3 or less from the viewpoint of improving the hole transport ability of the polymer.

(Percentage of dissociable groups)
The dissociable group may be contained in a portion other than the repeating unit of the dissociative polymer. The number of dissociable groups contained in the dissociable polymer chain is preferably 5 or more on average, more preferably 10 or more on average, and more preferably 50 or more on average.
Within the above range, it is preferable in that the solubility of the organic layer formed using the dissociative polymer in the organic solvent is sufficiently lowered.

Hereinafter, although the preferable specific example of the dissociative polymer in this invention is shown below, this invention is not limited to these.
[Concrete example]

The dissociative polymer in the present invention is preferably a conjugated polymer from the viewpoint of having sufficient charge transporting ability and sufficient solubility in a solvent because it comprises a repeating unit having a conjugated structure.
More specifically, it is preferably a polymer composed of a repeating unit represented by the formula (4).

(Glass transition temperature, other physical properties)
The glass transition temperature of the dissociative polymer in the present invention is usually 50 ° C. or higher, preferably 80 ° C. or higher, more preferably 100 ° C. or higher, from the viewpoint of driving stability including the heat resistance of the organic electroluminescent device. It is 300 degrees C or less.
The ionization potential of the dissociative polymer is usually 4.5 eV or more, preferably 4.8 eV or more, and usually 6.0 eV or less, preferably 5.7 eV or less, from the viewpoint of excellent charge transport ability.

(Content in the composition)
The content of the dissociating polymer in the charge transport film composition of the present invention is usually 1% by weight or more, preferably 2% by weight or more, and usually 6% by weight or less, preferably 5% by weight or less. . If the content of the dissociable polymer is too small, the charge transport ability may be insufficient. Moreover, when there is too much, the solubility with respect to the organic solvent of the composition for charge transport films | membranes may fall. When two or more different dissociative polymers are used in combination, the total content thereof is included in the above range.

(Advantages of being a polymer having a dissociable group)
In the case of stacking by a wet film forming method, the lower layer of the layer formed by the wet film forming method needs to have low solubility in a solvent.
Conventionally, a crosslinkable group has been used as a method for reducing the solubility in a solvent. When using a crosslinkable group, crosslinkable groups couple | bond together and the solubility with respect to a solvent will fall.

Further, since the crosslinkable groups must be bonded to each other, an unreacted crosslinkable group may remain when a layer is formed. If an unreacted crosslinkable group remains, when the obtained device is energized, the crosslinkable group may cause a redox reaction, which may affect the lifetime of the device.
On the other hand, in the case of a dissociable group, since it is a self-contained reaction, there are few unreacted dissociable groups in the formed layer compared with a crosslinkable group, and it is hard to be influenced by the drive lifetime of the element obtained.

Furthermore, after the dissociation reaction, the structure becomes an aromatic ring system, so that it is relatively stable to the redox reaction as compared to after the crosslinking of the crosslinkable group.
From these, the polymer having a dissociable group has a longer driving life of the resulting device.
[Electron-accepting compound]
The electron-accepting compound is preferably a compound having an oxidizing power and the ability to accept one electron from the above-described hole transporting compound, specifically, a compound having an electron affinity of 4 eV or more is preferable, and 5 eV or more. The compound which is the compound of these is further more preferable.

Examples of such electron-accepting compounds include triarylboron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids. Examples thereof include one or more compounds selected from the group.
The electron-accepting compound contained in the charge transport film composition of the present invention is an ionic compound having a structure in which at least one organic group is bonded to an element belonging to Groups 15 to 17 of the periodic table with a carbon atom. It is preferable that it is a compound represented by any one of the following formulas (I-1) to (I-3).

In formulas (I-1) to (I-3), R ¹¹ , R ²¹ and R ³¹ each independently represents an organic group bonded to A ^{1 to} A ³ via a carbon atom, and R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ each independently represent a substituent. Two or more adjacent groups among R ^{11 to} R ³⁴ may be bonded to each other to form a ring.
The type of R ¹¹ , R ²¹ and R ³¹ is not particularly limited as long as it does not impair the effects of the present invention as long as it is an organic group having a carbon atom at the bonding portion with A ^{1 to} A ³ . The organic group in the present invention is a group containing at least one carbon atom.

The molecular weights of R ¹¹ , R ²¹ and R ³¹ are each a value including the substituent, and are usually 1000 or less, preferably 500 or less. Preferred examples of R ¹¹ , R ²¹ and R ³¹ include alkyl groups, alkenyl groups, alkynyl groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups from the viewpoint of delocalizing positive charges. Among them, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferable because it delocalizes positive charges and is thermally stable.

  Examples of the aromatic hydrocarbon group include a monovalent group derived from a 5- or 6-membered monocyclic ring or a 2-5 condensed ring, and a group capable of delocalizing a positive charge on the group. Specific examples thereof include monovalent groups derived from a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluorene ring, and the like. Can be mentioned.

  The aromatic heterocyclic group is a monovalent group derived from a 5- or 6-membered monocyclic ring or a 2-4 condensed ring, and includes a group that can delocalize a positive charge on the group. Specific examples thereof include furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, triazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, Pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline And monovalent groups derived from a ring, an isoquinoline ring, a sinoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, an azulene ring, and the like.

Examples of the alkyl group include linear, branched, or cyclic alkyl groups having a carbon number of usually 1 or more and usually 12 or less, preferably 6 or less. Specific examples include methyl group, ethyl group, n-propyl group, 2-propyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group and the like.
Examples of the alkenyl group include those having usually 2 or more, usually 12 or less, preferably 6 or less. Specific examples include a vinyl group, an allyl group, and a 1-butenyl group.

Examples of the alkynyl group include those having usually 2 or more, usually 12 or less, preferably 6 or less. Specific examples include ethynyl group and propargyl group.
The type of R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ is not particularly limited as long as the effects of the present invention are not impaired. The molecular weights of R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ are each a value including the substituent, and are usually 1000 or less, preferably 500 or less. Examples of R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ include hydrogen atom, alkyl group, alkenyl group, alkynyl group, aromatic hydrocarbon group, aromatic heterocyclic group, amino group, alkoxy group, aryl Oxy, acyl, alkoxycarbonyl, aryloxycarbonyl, alkylcarbonyloxy, alkylthio, arylthio, sulfonyl, alkylsulfonyl, arylsulfonyl, sulfonyloxy, cyano, hydroxyl, thiol, silyl Groups and the like. Among them, like R ¹¹ , R ^21, and R ³¹ , an organic group having a carbon atom at the bond portion with A ^{1 to} A ³ is preferable from the viewpoint of high electron acceptability. Examples include an alkyl group, an alkenyl group, Alkynyl groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups are preferred. In particular, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferable because it has a large electron accepting property and is thermally stable.

Examples of the alkyl group, alkenyl group, alkynyl group, aromatic hydrocarbon group and aromatic heterocyclic group are the same as those described above for R ¹¹ , R ²¹ and R ³¹ .
Examples of the amino group include an alkylamino group, an arylamino group, and an acylamino group.
Examples of the alkylamino group include alkylamino groups having one or more alkyl groups usually having 1 or more carbon atoms and usually 12 or less, preferably 6 or less carbon atoms. Specific examples include methylamino group, dimethylamino group, diethylamino group, dibenzylamino group and the like.

Examples of the arylamino group include arylamino groups having at least one aromatic hydrocarbon group or aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. It is done. Specific examples include phenylamino group, diphenylamino group, tolylamino group, pyridylamino group, thienylamino group and the like.
The acylamino group includes an acylamino group having one or more acyl groups having usually 2 or more carbon atoms and usually 25 or less, preferably 15 or less carbon atoms. Specific examples include an acetylamino group and a benzoylamino group.

The alkoxy group includes an alkoxy group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less. Specific examples include a methoxy group, an ethoxy group, and a butoxy group.
Examples of the aryloxy group include aryloxy groups having an aromatic hydrocarbon group or an aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. Specific examples include phenyloxy group, naphthyloxy group, pyridyloxy group, thienyloxy group and the like.

Examples of the acyl group include acyl groups having usually 1 or more carbon atoms and usually 25 or less, preferably 15 or less. Specific examples include formyl group, acetyl group, benzoyl group and the like.
The alkoxycarbonyl group includes an alkoxycarbonyl group having usually 2 or more carbon atoms and usually 10 or less, preferably 7 or less. Specific examples include a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of the aryloxycarbonyl group include those having an aromatic hydrocarbon group or an aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 15 or less. Specific examples include a phenoxycarbonyl group and a pyridyloxycarbonyl group.
Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having usually 2 or more carbon atoms and usually 10 or less, preferably 7 or less. Specific examples include an acetoxy group and a trifluoroacetoxy group.

The alkylthio group includes an alkylthio group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less. Specific examples include a methylthio group and an ethylthio group.
The arylthio group includes an arylthio group having usually 3 or more, preferably 4 or more, and usually 25 or less, preferably 14 or less. Specific examples include a phenylthio group, a naphthylthio group, and a pyridylthio group.

Specific examples of the alkylsulfonyl group and the arylsulfonyl group include a mesyl group and a tosyl group.
Specific examples of the sulfonyloxy group include a mesyloxy group and a tosyloxy group.
Specific examples of the silyl group include a trimethylsilyl group and a triphenylsilyl group.

As described above, the groups exemplified as R ¹¹ , R ²¹ , R ³¹ and R ¹² , R ²² , R ²³ , R ^{32 to} R ³⁴ are further substituted with other substituents unless they are contrary to the gist of the present invention. May be. The type of the substituent is not particularly limited, and examples thereof include the groups exemplified above as R ¹¹ , R ²¹ , R ³¹ and R ¹² , R ²² , R ²³ , R ^{32 to} R ^34, as well as halogen atoms, cyano Group, thiocyano group, nitro group and the like. Among these, from the viewpoint of not hindering the heat resistance and electron acceptability of the ionic compound (electron accepting compound), an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an aromatic hydrocarbon group, an aromatic heterocyclic ring. Groups are preferred.

In formulas (I-1) to (I-3), A ¹ and A ² are elements after the third period (third to sixth periods) of the periodic table, and A ³ is after the second period of the periodic table (second To 6th period), A ¹ represents an element belonging to Group 17 of the long-period periodic table, A ² represents an element belonging to Group 16 and A ³
Represents an element belonging to Group 15.
Among these, from the viewpoint of electron acceptability and availability, elements before the fifth period of the periodic table are preferable. That is, A ¹ is preferably any ^one of an iodine atom, a bromine atom, and a chlorine atom, A ² is preferably any one of a tellurium atom, a selenium atom, and a sulfur atom, and A ³ is preferably an antimony atom, an arsenic atom, Either a phosphorus atom or a nitrogen atom is preferable. In particular, from the viewpoint of electron acceptability and stability of the compound, A ¹ in formula (I-1) is a bromine atom or iodine atom, and A ² in formula (I-2) is selenium atom or sulfur. An electron-accepting compound that is an atom, and an electron-accepting compound in which A ³ in the formula (I-3) is a nitrogen atom are preferable. Among them, an electron-accepting compound in which A ¹ in the formula (I-1) is an iodine atom, An electron-accepting compound in which A ³ in formula (I-3) is a nitrogen atom is most preferable.

In formulas (I-1) to (I-3), Z ₁ ^{n1 to} Z ₃ ⁿ³ each independently represents a counter anion. The type of the counter anion is not particularly limited, and may be a monoatomic ion or a complex ion. However, the larger the size of the counter anion, the more the negative charge is delocalized, and the positive charge is also delocalized thereby increasing the electron accepting ability. Therefore, the complex ion is preferable to the monoatomic ion.
n _{1 to} n ₃ are each independently an arbitrary positive integer corresponding to the ionic value of the counter anions Z ₁ ^{n1 to} Z ₃ ⁿ³⁻ . The values of n _{1 to} n ₃ are not particularly limited, but all are preferably 1 or 2, and most preferably 1.

Specific examples of Z ₁ ^{n1- to} Z ₃ ^n3- include hydroxide ion, fluoride ion, chloride ion, bromide ion, iodide ion, cyanide ion, nitrate ion, nitrite ion, sulfate ion, sulfite. Ion, perchlorate ion, perbromate ion, periodate ion, chlorate ion, chlorite ion, hypochlorite ion, phosphate ion, phosphite ion, hypophosphite ion, borate ion , Isocyanate ion, hydrosulfide ion, tetrafluoroborate ion, hexafluorophosphate ion, hexachloroantimonate ion; carboxylate ion such as acetate ion, trifluoroacetate ion, benzoate ion; methanesulfonic acid, trifluoromethane Sulfonate ions such as sulfonate ions; Alkoxy ions such as methoxy ions and t-butoxy ions And tetrafluoroborate ions and hexafluoroborate ions are preferred.

The counter anions Z ₁ ^{n1 to} Z ₃ ⁿ³ are represented by any of the following formulas (I-4) to (I-6) from the viewpoint of the stability of the compound and the solubility in organic solvents. The complex ion represented by the formula (I-6) is preferable because the negative charge is delocalized and the positive charge is delocalized to increase the electron accepting ability. Ions are more preferred.

In formulas (I-4) and (I-6), E ¹ and E ³ each independently represent an element belonging to Group 13 of the long-period periodic table. Of these, a boron atom, an aluminum atom, and a gallium atom are preferable, and a boron atom is preferable from the viewpoint of stability of the compound and ease of synthesis and purification.
In formula (I-5), E ² represents an element belonging to Group 15 of the long-period periodic table. Among these, a phosphorus atom, an arsenic atom, and an antimony atom are preferable, and a phosphorus atom is preferable from the viewpoint of stability of the compound, synthesis and purification, and toxicity.

In the formulas (I-4) and (I-5), X represents a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom, and the fluorine atom, A chlorine atom is preferred, and a fluorine atom is most preferred.
In formula (I-6), Ar ^{1 to} Ar ⁴ each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group. Examples of the aromatic hydrocarbon group and aromatic heterocyclic group are derived from the same 5- or 6-membered monocyclic ring or 2-4 condensed ring as those exemplified above for R ¹¹ , R ²¹ and R ³¹ . A monovalent group is mentioned. Among these, a monovalent group derived from a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, or an isoquinoline ring is preferable from the viewpoint of stability and heat resistance of the compound.

The aromatic hydrocarbon group and aromatic heterocyclic group exemplified as Ar ^{1 to} Ar ⁴ may be further substituted with another substituent as long as they do not contradict the gist of the present invention. The type of the substituent is not particularly limited, and any substituent can be applied, but an electron-withdrawing group is preferable.
Examples of preferable electron-withdrawing groups as the substituent that Ar ^{1 to} Ar ⁴ may have include halogen atoms such as fluorine atom, chlorine atom and bromine atom; cyano group; thiocyano group; nitro group; mesyl group Alkylsulfonyl groups such as tosyl group; arylsulfonyl groups such as tosyl group; acyl groups such as formyl group, acetyl group, benzoyl group and the like, usually having 1 or more, usually 12 or less, preferably 6 or less; methoxycarbonyl group, ethoxycarbonyl An alkoxycarbonyl group having 2 or more carbon atoms, usually 10 or less, preferably 7 or less; a phenoxycarbonyl group, a pyridyloxycarbonyl group or the like, and usually having 3 or more carbon atoms, preferably 4 or more and usually 25 or less. An aryloxycarbonyl group having an aromatic hydrocarbon group or an aromatic heterocyclic group of preferably 15 or less; A fluorine atom on a linear, branched or cyclic alkyl group having usually 1 or more, usually 10 or less, preferably 6 or less, such as a sulfonyl group; an aminosulfonyl group; a trifluoromethyl group or a pentafluoroethyl group And a haloalkyl group substituted with a halogen atom such as a chlorine atom.

Among them, it is more preferable that at least one group out of Ar ^{1 to} Ar ⁴ has one or more fluorine atoms or chlorine atoms as substituents. In particular, it is most preferably a perfluoroaryl group in which all of the hydrogen atoms of Ar ^{1 to} Ar ⁴ are substituted with fluorine atoms from the viewpoint of efficiently delocalizing negative charges and having an appropriate sublimation property. preferable. Specific examples of the perfluoroaryl group include a pentafluorophenyl group, a heptafluoro-2-naphthyl group, and a tetrafluoro-4-pyridyl group.

  The molecular weight of the electron-accepting compound in the present invention is usually 100 or more, preferably 300 or more, more preferably 400 or more, and usually 5000 or less, preferably 3000 or less, more preferably 2000 or less. If the molecular weight of the electron-accepting compound is too small, delocalization of the positive charge and negative charge is insufficient, which may reduce the electron accepting ability. If the molecular weight of the electron-accepting compound is too large, the electron accepting compound The active compound itself may interfere with charge transport.

  Specific examples of the electron-accepting compound in the present invention are listed below, but the present invention is not limited thereto.

  Among the above specific examples, A-1 to 48, A-54, A-55, A-60 to 62, and A-64 to 75 are preferable from the viewpoint of electron acceptability, heat resistance, and solubility in organic solvents. A-79 to 83, B-1 to 20, B-24, B-25, B-27, B-30 to 37, B-39 to 43, C-1 to 10, C-19 to 21, C -25 to 27, C-30, C-31, D-15 to 28, and more preferably A-1 to 9, A-12 to 15, A-17, A-19, A-24. A-29, A-31 to 33, A-36, A-37, A-65, A-66, A-69, A-80 to 82, B-1 to 3, B-5, B-7 -10, B-16, B-30, B-33, B-39, C-1 to 3, C-5, C-10, C-21, C-25, C-31, D-17 to 28 And the most Preferably, A-1 to 7, a compound of A-80, D-21~24.

The method for producing the electron-accepting compound described above is not particularly limited, and can be produced using various methods. As an example, Chem. Rev. 66, 243, 1966, and J. Am. Org. Chem. 53, page 5571, 1988, and the like.
The composition for a charge transport film of the present invention may contain any one of the above-described electron-accepting compounds alone, or may contain two or more kinds in any combination and ratio. Two or more electron-accepting compounds corresponding to any one of the formulas (I-1) to (I-3) may be combined, and two or more electron-accepting properties corresponding to different formulas may be used. You may combine a compound.

The content of the above-described electron-accepting compound in the charge transport film composition of the present invention is usually 0.1% by weight or more, preferably 1% by weight or more, and usually 100%, based on the above-mentioned dissociative polymer. % By weight or less, preferably 40% by weight or less.
Within the above range, the driving voltage is low and the film formability is good, which is preferable.
When two or more kinds of electron-accepting compounds are used in combination, the total content is included in the above range.

[Organic solvent]
The organic solvent is preferably an organic solvent that dissolves the dissociative polymer in the present invention in an amount of usually 0.05% by weight or more, preferably 0.5% by weight or more, and more preferably 1% by weight or more. In addition, it is preferable to dissolve 0.005% by weight or more of the electron-accepting compound, more preferably 0.05% by weight or more, and even more preferably 0.5% by weight or more.

Specific examples of the organic solvent include aromatic organic solvents, halogen-containing organic solvents, ether-based organic solvents, and ester-based organic solvents.
Specific examples of the aromatic organic solvent include toluene, xylene, methicylene, cyclohexylbenzene, pentafluoromethoxybenzene, ethyl (pentafluorobenzoate), etc.
Specific examples of the halogen-containing organic solvent include 1,2-dichloroethane, chlorobenzene, o-dichlorobenzene, and the like.
Specific examples of the ether organic solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethoxybenzene , Anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4
-Aromatic ethers such as methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, diphenyl ether, etc.
Specific examples of the ester organic solvent include aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, And aromatic esters such as n-butyl benzoate.

Because it is necessary to dissolve the dissociative polymer, and the ability to dissolve the cation radical of the hole injection / transport material resulting from the mixture of the hole transport material such as the dissociative polymer and the electron accepting compound is high. Preferably, an ether organic solvent and an ester organic solvent are used.
These may be used alone or as a mixed organic solvent of two or more.

  As an organic solvent contained in the composition for a charge transport film of the present invention, the vapor pressure at 25 ° C. is 2 mmHg or more, preferably 3 mmHg or more, more preferably 4 mmHg or more (however, the upper limit is preferably 10 mmHg or less). And an organic solvent having a vapor pressure at 25 ° C. of less than 2 mmHg, preferably 1 mmHg or less, more preferably 0.5 mmHg or less.

The concentration of these organic solvents in the composition is usually 10% by weight or more, preferably 30%.
% By weight or more, more preferably 50% by weight or more. In addition to the organic solvents described above, various other organic solvents may be included as necessary as the organic solvent. Examples of such other organic solvents include amide organic solvents such as N, N-dimethylformamide and N, N-dimethylacetamide, and dimethyl sulfoxide. Moreover, various additives, such as a leveling agent and an antifoamer, may be included.

  In addition, it is widely known that moisture may promote deterioration of the performance of the organic electroluminescent element, particularly brightness reduction during continuous driving, in order to reduce moisture remaining in the coating film as much as possible. Among these organic solvents, those having a solubility of water at 25 ° C. of 1% by weight or less are preferable, and organic solvents having a solubility of 0.1% by weight or less are more preferable. Moreover, as an organic solvent, the organic solvent whose surface tension in 20 degreeC is less than 40 dyn / cm normally, Preferably it is 36 dyn / cm or less, More preferably, it is 33 dyn / cm or less. Examples of the organic solvent include organic solvents having a vapor pressure at 25 ° C. of 10 mmHg or less, preferably 5 mmHg or less and usually 0.1 mmHg or more. By using such an organic solvent, it is possible to prepare a composition suitable for a process for producing an organic electroluminescent device by a wet film forming method and suitable for the properties of a dissociative polymer.

[Physical properties of charge transport film composition]
The viscosity of the composition for a charge transport film of the present invention depends on the concentration of solids, but is usually 15 mPas or less, preferably 10 mPas or less, more preferably 8 mPas or less, and usually 2 mPas or more, preferably 3 mPas or more, more preferably 5 mPas or more.
Within this range, it is preferable in that a film can be uniformly formed during film formation by a wet film formation method.

The viscosity was measured using a rotary viscosity measuring device. Usually, the viscosity depends on the temperature and the number of rotations measured. The above values are measured values under measurement conditions of a measurement temperature of 23 ° C. and a measurement rotation number of 20 rotations.
[Additive]
Moreover, the composition for charge transport films of the present invention may contain various additives such as coating improvers such as a leveling agent and an antifoaming agent, if necessary. In this case, as the organic solvent, an organic solvent that dissolves both the dissociative polymer and the additive at 0.05% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more should be used. Is preferred.

<Application>
The composition for a charge transport film of the present invention has high storage stability, and when an organic layer is formed by a wet film formation method, it can be formed uniformly and does not cause a disadvantage from an industrial viewpoint. It is preferably used for an organic electroluminescence device.
In addition, the wet film forming method in the present invention is a spin coating method, dip coating method, die coating method, bar coating method, blade coating method, roll coating method, spray coating method, capillary coating method, composition jet method, screen printing. The method of forming into a film using the composition containing organic solvents, such as a printing method, a gravure printing method, a flexographic printing method, and offset printing. From the viewpoint of easy patterning, a die coating method, a roll coating method, a spray coating method, a composition jet method, and a flexographic printing method are preferable.

<Method for producing composition for charge transport film>
Although an example of the manufacturing method of the composition for charge transport films | membranes of this invention is shown below, this invention is not limited to these.
In particular, the composition for a charge transport film of the present invention can be produced by using a combination of the methods described below, particularly preferable methods.

[1] Addition form / method
When mixing the dissociative polymer, the electron accepting compound and the organic solvent contained in the charge transport film composition of the present invention, the dissociating polymer and the electron accepting compound to be mixed are each independently a solid. It may also be a solution.
It is preferable to mix the dissociable polymer and the electron-accepting compound together in a solution state.

In this case, as long as each organic solvent does not impair the effects of the present invention, different organic solvents may be used as long as they are within the range of the organic solvent described above, or two or more organic solvents may be mixed and used.
Further, it is preferable that either the dissociative polymer or the electron-accepting compound is mixed in a solid state and either one is mixed in a solution state. In this case, it is preferable to add the solid to the solution in that it can be added while confirming the dissolution of the solid.

Furthermore, it is preferable that the dissociative polymer and the electron-accepting compound are both solid, and after these are pulverized and mixed, they are dissolved in an organic solvent.
When mixed as a solid as described above, the particle size is usually 5 cm or less, preferably 1 cm or less, more preferably 5 mm or less, and usually 0.5 mm or more.
[2] Dissolution process
In the manufacturing method of the composition for charge transport films of this invention, it has a melt | dissolution process normally.

The dissolution step refers to a step of stirring a solid in an organic solvent so that it cannot be visually confirmed that the solid is floating.
(solubility condition)
The temperature in the dissolving step is usually 20 ° C. or higher, preferably 40 ° C. or higher, and usually lower than the boiling point of the organic solvent, preferably 10 ° C. lower than the boiling point of the organic solvent. If the upper limit is exceeded, the organic solvent may partially evaporate and the concentration may change. If the lower limit is not reached, the organic solvent used may solidify or the solubility may decrease, and the desired concentration may not be obtained. There is.

The atmosphere in the dissolution step is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include an inert gas. As an inert gas, nitrogen, argon, etc. are mentioned, for example, Nitrogen is preferable at the point which is easy to handle.
[3] Ultrasonic treatment, light irradiation treatment, heat treatment
The production method for obtaining the charge transport film composition of the present invention preferably includes at least one of ultrasonic treatment, light irradiation treatment, and heat treatment.

Moreover, there is no restriction | limiting in particular unless the effect of this invention is impaired, the time which performs a process may be performed in a melt | dissolution process, and may be performed after a melt | dissolution process.
In addition, these processes may perform any one kind of process independently, and may perform a process in combination.
(Sonication)
When performing ultrasonic treatment, it is preferable to use a vibrator of 28 kHz.

The ultrasonic time in the ultrasonic treatment is usually 5 minutes or longer, preferably 10 minutes or longer, and usually 2 hours or shorter, preferably 1 hour or shorter.
If the upper limit is exceeded, the polymer may be decomposed, and if the lower limit is not reached, dissolution may be insufficient.
(Light irradiation treatment)
When performing the light irradiation treatment, it is preferable to use a high-pressure mercury lamp. The high pressure mercury lamp is a greenish bluish white (5,700 K) light source composed of emission lines of 404.7 nm, 435.8 nm, 546.1 nm, 577.0 nm, and 579.1 nm, and is 253.7 nm, 365
. With 0 nm UV irradiation.

  Although it does not specifically limit as an ultraviolet irradiation method, You may irradiate directly to the prepared composition, and you may irradiate an ultraviolet ray in a suitable container. When the container transmits ultraviolet rays, the container may be irradiated with ultraviolet rays, and when the container shields the ultraviolet rays, for example, the lid may be opened and the ultraviolet rays may be irradiated from the opening. The apparatus used for the ultraviolet irradiation is not particularly limited, and a xenon lamp, a mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, an ultraviolet fluorescent lamp, a D2 lamp, a carbon arc lamp, an LED, or the like is used.

Further, the liquid temperature of the composition when the composition contains a solvent is not particularly limited, but is usually room temperature, but may be further cooled or heated.
The dose of the ultraviolet radiation is typically 10 mJ / cm ² or more, preferably 100 mJ / cm ² or more, more preferably 600 mJ / cm ² or more, usually 50000mJ / cm ² hereinafter, preferably 1
0000mJ / cm ² or less, more preferably 5000 mJ / cm ² or less. Within the above range, it is preferable because the electron mobility from the dissociative polymer to the electron accepting compound is sufficient, and the dissociative polymer is hardly deteriorated.

Usually, since ultraviolet rays are absorbed on the surface of the composition, it is preferable to stir the composition uniformly after irradiation with ultraviolet rays or to irradiate ultraviolet rays while stirring.
As the irradiation area of the ultraviolet rays, it is preferable that the entire container containing the composition is irradiated with ultraviolet rays, but a part of the composition may be irradiated. In that case, it is preferable to stir the composition after ultraviolet irradiation, and it is also preferable to irradiate the composition while stirring.

(Heat treatment)
As the heating means in the heat treatment, a known technique can be used as long as the effects of the present invention are not impaired.
Specifically, a method in which a dissociative polymer, an electron accepting compound, and an organic solvent are placed in a heatable container, the temperature is adjusted with a heating bath while stirring, and the mixture is heated and stirred. A water bath, an oil bath, etc. are used as a heating bath.

Moreover, after dissociating a polymer, an electron-accepting compound, and an organic solvent are put into a heating container and stirred, heat treatment can be performed by placing the dissociating polymer, an electron-accepting compound, and an organic solvent in a constant-temperature bath whose temperature can be controlled. From the viewpoint of safety, a method by heating and stirring using a heating bath is preferable.
The heating temperature in the heat treatment is usually 40 ° C. or higher, preferably 80 ° C. or higher, and usually lower than the boiling point of the organic solvent, preferably 10 ° C. lower than the boiling point of the organic solvent.

When two different kinds of organic solvents are used, the boiling point as the upper limit is based on the boiling point of the lowest boiling organic solvent.
If this upper limit is exceeded, there is a risk that the organic solvent will bump, and the concentration of the organic solvent will change due to evaporation of the organic solvent. On the other hand, if the lower limit is not reached, there is no possibility of heat treatment and there is a risk of insufficient dissolution.

The heating time in the heat treatment is usually 1 hour or longer, preferably 5 hours or longer, and usually 36 hours or shorter, preferably 24 hours or shorter. If the upper limit is exceeded, the organic solvent may evaporate, and if the lower limit is not reached, dissolution may be insufficient.
The reason why the charge transport film composition of the present invention can be produced by performing at least one of ultrasonic treatment, light irradiation treatment, and heat treatment is presumed as follows.

By performing any one of ultrasonic treatment, light irradiation treatment, and heat treatment, the disaggregation state of the dissociative polymer is relaxed, so that the dissociative polymer and the electron-accepting compound are easily brought close to each other. Due to this proximity, the dissociative polymer becomes a cation radical state in the molecule, becomes an ion pair state with the electron accepting compound which is an anion radical, and the aggregation of the polymer and the electron accepting compound is less likely to occur. A composition for a charge transport film having a small proportion containing large aggregates on the order of microns can be produced.

[4] Filtration process
In the manufacturing method of the composition for charge transport films of this invention, it is preferable to include a filtration process. Moreover, it is preferable to perform the filtration process in this invention after a melt | dissolution process.
The filter hole used in the filtration step is usually 5 μm or less, preferably 0.5 μm or less, and usually 0.1 μm or more.

If the upper limit is exceeded, insolubles may be mixed in, and if the lower limit is not reached, filtration may not be possible and clogging may occur.
[Film formation method]
As described above, since the organic electroluminescent element is formed by laminating a plurality of layers made of organic compounds, it is very important that the film quality is uniform. When a layer is formed by a wet film formation method, a known film formation method such as a coating method such as a spin coating method or a spray method, or a printing method such as an ink jet method or a screen method can be adopted depending on the material and properties of the base. .

In the case of using a wet film forming method, the charge transport film composition of the present invention is applied onto a layer corresponding to the lower layer of the layer to be formed by a technique such as spin coating or dip coating, and dried to form a layer. Form.
After coating, the film of the charge transport film composition is dried by heating or the like. As a drying method, a heating step is usually performed. Examples of the heating means used in the heating step include a clean oven, a hot plate, infrared rays, a halogen heater, microwave irradiation and the like. Among them, a clean oven and a hot plate are preferable in order to uniformly apply heat to the entire film.

  The heating temperature in the heating step is preferably heated at a temperature equal to or higher than the boiling point of the solvent used in the charge transport film composition as long as the effects of the present invention are not significantly impaired. Moreover, it is preferable to heat at the temperature more than the temperature which the dissociative group mentioned above dissociates in a layer. In the case of a mixed solvent containing two or more types of solvents used in the charge transport film composition, at least one type is preferably heated at a temperature equal to or higher than the boiling point of the solvent. In consideration of an increase in the boiling point of the solvent, the heating step is preferably performed at 120 ° C or higher, preferably 410 ° C or lower.

  In addition to heating, in the case of irradiation with active energy such as light, a method of irradiating directly using an ultraviolet / visible / infrared light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a halogen lamp, an infrared lamp, Or the mask aligner incorporating the above-mentioned light source, the method of irradiating using a conveyor type | mold light irradiation apparatus, etc. are mentioned. In active energy irradiation other than light, for example, there is a method of irradiation using a so-called microwave oven that irradiates a microwave generated by a magnetron.

As the irradiation time, it is preferable to set conditions necessary for sufficient insolubilization reaction to occur, but irradiation is usually performed for 0.1 second or longer, preferably 10 hours or shorter.
The irradiation of active energy such as heating and light may be performed alone or in combination. When combined, the order of implementation is not particularly limited.
In order to reduce the amount of moisture contained in the layer and / or moisture adsorbed on the surface after execution, the irradiation of active energy such as heating and light is preferably performed in an atmosphere containing no moisture such as a nitrogen gas atmosphere. For the same purpose, when combined with heating and / or irradiation with active energy such as light, it is particularly preferable to perform at least the process immediately before the formation of the light emitting layer in an atmosphere containing no moisture such as a nitrogen gas atmosphere.

<Organic electroluminescent device>
The organic electroluminescent device of the present invention is an organic electroluminescent device having an anode and a cathode, and an organic layer disposed between the anode and the cathode on a substrate, and at least one of the organic layers has the charge transport of the present invention. It is a layer formed of a film composition.
The organic layer may be a single layer or a laminate of two or more layers. Examples of the organic layer include a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and the like, and a layer formed by the charge transport film composition of the present invention. The organic electroluminescent element which is a layer adjacent to the anode has an effect that no short circuit or dark spot occurs. Therefore, it is usually preferable that the layer formed of the charge transport film composition of the present invention is a hole injection layer. Moreover, it is preferable that it has a positive hole injection layer, a positive hole transport layer, and a light emitting layer as an organic layer, and all these are formed by the wet film-forming method. Moreover, the organic electroluminescent element of this invention may have an inorganic layer.

Hereinafter, an example of a layer structure of an organic electroluminescence device produced by the method of the present invention, a general formation method thereof, and the like will be described with reference to FIG.
FIG. 1 is a schematic cross-sectional view showing a structural example of an organic electroluminescent device manufactured by the method of the present invention. In FIG. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, and 4 is a hole. The transport layer, 5 represents a light emitting layer, 6 represents a hole blocking layer, 7 represents an electron transport layer, 8 represents an electron injection layer, and 9 represents a cathode.

In addition, in such an organic electroluminescent element, when the organic layer between the anode and the cathode is formed by a wet film forming method, the material of each layer described below is dispersed or dissolved in an organic solvent to form a wet film. A composition for a film may be prepared and formed using the wet film-forming composition.
[substrate]
The substrate serves as a support for the organic electroluminescence device, and quartz or glass plates, metal plates or metal foils, plastic films, sheets, or the like are used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, polysulfone or the like is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic electroluminescent element may be deteriorated by the outside air that has passed through the substrate, which is not preferable. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also a preferable method.

[anode]
The anode plays a role of hole injection into the layer on the light emitting layer side.
This anode is usually made of metal such as aluminum, gold, silver, nickel, palladium, platinum, metal oxide such as indium and / or tin oxide, metal halide such as copper iodide, carbon black, or poly It is composed of conductive polymers such as (3-methylthiophene), polypyrrole and polyaniline.

  The anode is usually formed by a sputtering method, a vacuum deposition method, or the like. In addition, when forming an anode using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, and conductive polymer fine powder, an appropriate binder resin solution is used. The anode can also be formed by dispersing and coating the substrate. Further, in the case of a conductive polymer, a thin film can be directly formed on a substrate by electrolytic polymerization, or an anode can be formed by applying a conductive polymer on a substrate (Appl. Phys. Lett. , 60, 2711, 1992).

The anode usually has a single-layer structure, but it can also have a laminated structure composed of a plurality of materials if desired.
The thickness of the anode varies depending on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and is usually 1000 nm or less, preferably about 500 nm or less. When opaqueness is acceptable, the thickness of the anode is arbitrary, and the anode may be the same as the substrate. Furthermore, it is also possible to laminate different conductive materials on the anode.

For the purpose of removing impurities adhering to the anode and adjusting the ionization potential to improve the hole injection property, the anode surface is treated with ultraviolet (UV) / ozone, oxygen plasma or argon plasma. Is preferred.
[Hole injection layer]
The hole injection layer is a layer having a function of transporting holes from the anode to the light emitting layer, and is usually formed on the anode.

In order to exhibit this function, the hole injection layer is preferably a layer formed of the charge transport film composition of the present invention.
(Film formation method)
After the charge transport film composition of the present invention is prepared, the composition is wet-deposited, wet-deposited on a layer corresponding to the lower layer of the hole injection layer (usually an anode), and dried to obtain a positive charge. A hole injection layer is formed.

The temperature in the wet film formation is preferably 10 ° C. or higher, and preferably 50 ° C. or lower, in order to prevent film defects due to the formation of crystals in the composition.
The relative humidity in the wet film formation is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.01 ppm or more and usually 80% or less.
After film formation, the film of the composition for charge transport film of the present invention is dried by heating or the like. When the drying method is heating, the heating means is not particularly limited, and examples thereof include a clean oven, a hot plate, an infrared ray, a halogen heater, and microwave irradiation. Among them, a clean oven and a hot plate are preferable in order to uniformly apply heat to the entire film.

  Moreover, as for heating temperature, unless the effect of this invention is impaired remarkably, it is preferable to heat at the temperature more than the boiling point of the organic solvent used for the composition for charge transport films of this invention. In the case of a mixed organic solvent containing two or more organic solvents used in the charge transport film composition of the present invention, it is preferable that at least one kind is heated at a temperature equal to or higher than the boiling point of the organic solvent. In consideration of an increase in the boiling point of the organic solvent, the heating step is preferably performed at 120 ° C. or higher, preferably 410 ° C. or lower.

The heating time is not particularly limited as long as the heating temperature is equal to or higher than the boiling point of the organic solvent of the composition for charge transport film of the present invention and the film formed by wet film formation is sufficiently insolubilized, but preferably 10 seconds. Above, and usually 180 minutes or less. Within the above range, a uniform film tends to be formed, which is preferable. Heating may be performed in two steps.
The film thickness formed by the above method is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[Hole transport layer]
The organic electroluminescent element of the present invention preferably has a hole transport layer.
The method for forming the hole transport layer according to the present invention is not particularly limited, but the hole transport layer is preferably formed by wet film formation from the viewpoint of reducing dark spots.
In the case of the organic electroluminescence device having the configuration shown in FIG. 1, the hole transport layer can be formed on the hole injection layer.

  The material that can be used for the hole transport layer is preferably a material that has a high hole transport property and can efficiently transport the injected holes. Therefore, it is preferable that the ionization potential is small, the transparency to visible light is high, the hole mobility is large, the stability is high, and impurities that become traps are not easily generated during manufacturing or use. In many cases, it is in contact with the light-emitting layer, so it is preferable not to quench the light emitted from the light-emitting layer or reduce the efficiency by forming an exciplex with the light-emitting layer.

As a material for such a hole transport layer, any material that has been conventionally used as a material for a hole transport layer may be used. For example, what was illustrated as a hole transportable compound contained in the composition for charge transport films of this invention is mentioned. In addition, two or more condensed aromatic rings including two or more tertiary amines represented by 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl are substituted with nitrogen atoms. Aromatic diamine (Japanese Patent Laid-Open No. 5-234681), 4,4 ′
, 4 ″ -tris (1-naphthylphenylamino) triphenylamine and other aromatic amine compounds having a starburst structure (J. Lumin., 72-74, 985, 1997), triphenylamine Spiro compounds such as aromatic amine compounds (Chem. Commun., 2175, 1996), 2,2 ′, 7,7′-tetrakis- (diphenylamino) -9,9′-spirobifluorene (Synth. Metals,
91, 209 (1997), carbazole derivatives such as 4,4′-N, N′-dicarbazolebiphenyl, and the like. Further, for example, polyvinyl carbazole, polyvinyl triphenylamine (Japanese Patent Laid-Open No. 7-53953), polyarylene ether sulfone (Polym. Adv. Tech., 7, 33, 1996) containing tetraphenylbenzidine, etc. Can be mentioned.

In the case of forming a hole transport layer by a wet film formation method, a composition for forming a hole transport layer is prepared, followed by film formation and heat drying. The composition for forming a hole transport layer contains an organic solvent in addition to the hole transport compound. The organic solvent is the same as that used in the charge transport film composition of the present invention. The film forming conditions, heat drying conditions, and the like are the same as in forming the hole injection layer.
The film formation conditions and the like for forming the hole transport layer by vacuum vapor deposition are as follows.

(Formation of hole transport layer by vacuum evaporation)
When forming the hole transport layer by vacuum deposition, one or more of the constituent materials of the hole transport layer (the aforementioned hole transport compound, electron accepting compound, etc.) are placed in a vacuum vessel. Put in crucibles (in case of using two or more kinds of materials, put them in each crucible), evacuate the inside of the vacuum vessel to about 10 ⁻⁴ Pa with a suitable vacuum pump, and then heat the crucible (two or more kinds) When using materials, heat each crucible) and evaporate by controlling the amount of evaporation (when using two or more materials, evaporate by independently controlling the amount of evaporation) and place it facing the crucible. A hole transport layer is formed on the anode of the substrate. In addition, when using 2 or more types of materials, those hole mixtures can also be put into a crucible, and it can heat and evaporate and can form a positive hole transport layer.

The degree of vacuum at the time of vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 × 10 ⁻⁶ Torr (0.13 × 10 ⁻⁴ Pa) or more, usually 9.0 × 10 ⁻⁶ Torr. (12.0 × 10 ⁻⁴ Pa) or less. The deposition rate is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 Å / second or more and usually 5.0 Å / second or less. The film forming temperature at the time of vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 10 ° C. or higher, preferably 50 ° C. or lower.

The hole transport layer may contain various light emitting materials, electron transport compounds, binder resins, coatability improvers, and the like in addition to the hole transport compound.
The hole transport layer may be a layer formed by crosslinking a crosslinkable compound. The crosslinkable compound is a compound having a crosslinkable group, which will be described later, and forms a network-like aromatic amine-based polymer by crosslinking. The crosslinkable compound may be any of a monomer, an oligomer, and a polymer, and among them, an aromatic amine-based polymer is preferable. The crosslinkable compound may have only 1 type, and may have 2 or more types by arbitrary combinations and ratios.

Moreover, a crosslinkable group means the group which reacts with the same or different group of the other molecule | numerator located in the vicinity, and produces | generates a novel chemical bond. For example, the group which reacts with the same or different group of the other molecule | numerator located in the vicinity by irradiation of a heat | fever and / or active energy ray, and produces | generates a novel chemical bond is mentioned.
Examples of crosslinkable groups include cyclic ethers such as oxetane groups and epoxy groups; unsaturated double bonds such as vinyl groups, trifluorovinyl groups, styryl groups, acrylic groups, methacryloyl groups, cinnamoyl groups; benzocyclobutane groups, etc. Is mentioned.

  There is no particular limitation on the number of crosslinkable groups that the monomer, oligomer or polymer having a crosslinkable group has, but it is usually less than 2.0, preferably 0.8 or less, more preferably 0.5 or less per charge transport unit. Number is preferred. This is to keep the relative dielectric constant of the crosslinkable compound within a suitable range. Moreover, if the number of crosslinkable groups is too large, reactive active species are generated, which may adversely affect other materials. Here, when the material forming the network-like aromatic amine polymer is a monomer, the charge transport unit is a monomer itself, and indicates a skeleton excluding a crosslinkable group (main skeleton). Even when other types of monomers are mixed, the main skeleton of each monomer is shown. When the material forming the network polymer is an aromatic amine-based polymer, in the case of a structure in which conjugation is broken organically, the repeated structure is used as a charge transport unit. Further, in the case of a structure in which conjugation is widely linked, the minimum repeating structure exhibiting charge transporting property is the structure of a monomer. Examples include polycyclic aromatics such as naphthalene, triphenylene, phenanthrene, tetracene, chrysene, pyrene, and perylene, fluorene, triphenylene, carbazole, triarylamine, tetraarylbenzidine, 1,4-bis (diarylamino) benzene, and the like. It is done.

  Furthermore, it is preferable to use a hole transporting compound having a crosslinkable group as the crosslinkable compound. Examples of hole transporting compounds include nitrogen-containing aromatic compound derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives, phthalocyanine derivatives, porphyrin derivatives; triphenylamine derivatives Silole derivatives; oligothiophene derivatives, condensed polycyclic aromatic derivatives, metal complexes and the like. Among them, nitrogen-containing aromatic derivatives such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, carbazole derivatives; triphenylamine derivatives, silole derivatives, condensed polycyclic aromatic derivatives, metal complexes, etc. Particularly preferred are triphenylamine derivatives. The molecular weight of the crosslinkable compound is usually 5000 or less, preferably 2500 or less, preferably 300 or more, more preferably 500 or more.

In order to form a hole transport layer by crosslinking a crosslinkable compound, a coating liquid (composition for forming a hole transport layer) in which a crosslinkable compound is dissolved or dispersed in an organic solvent is usually prepared, and wet film formation is performed. To form a film and crosslink.
In addition to the crosslinkable compound, the coating solution may contain an additive that accelerates the crosslinking reaction. Examples of additives that accelerate the crosslinking reaction include: crosslinking initiators and crosslinking accelerators such as alkylphenone compounds, acylphosphine oxide compounds, metallocene compounds, oxime ester compounds, azo compounds, onium salts; condensed polycyclic hydrocarbons; And photosensitizers such as porphyrin compounds and diaryl ketone compounds. Further, it may contain a coating property improving agent such as a leveling agent and an antifoaming agent; an electron accepting compound: a binder resin, and the like.

The organic solvent used for the coating solution is the same as that exemplified as the organic solvent for forming the hole injection layer. In the coating solution, the crosslinkable compound is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, usually 50% by weight or less, preferably 20% by weight or less, more preferably. Contains 10% by weight or less.
After forming the coating solution on the lower layer, the crosslinkable compound is crosslinked to form a network polymer by heating and / or irradiation with active energy rays. The heating method after film formation is not particularly limited, and examples thereof include heat drying and reduced pressure drying. As conditions for the heat drying, the layer formed at 120 ° C. or higher, preferably 400 ° C. or lower is heated. The heating time is usually 1 minute or longer, preferably 24 hours or shorter. The heating means is not particularly limited, and means such as placing a laminated body having a deposited layer on a hot plate or heating in an oven is used. For example, conditions such as heating on a hot plate at 120 ° C. or more for 1 minute or more can be used.

  In the case of active energy ray irradiation, a method of direct irradiation using an ultraviolet, visible, or infrared light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a halogen lamp, or an infrared lamp, or a mask aligner incorporating the aforementioned light source And a method of irradiating using a conveyor type light irradiation device. In active energy ray irradiation other than light, for example, there is a method of irradiation using a device that irradiates a microwave generated by a magnetron, a so-called microwave oven. As the irradiation time, it is preferable to set conditions necessary for reducing the solubility of the film, but irradiation is usually performed for 0.1 seconds or longer, preferably 10 hours or shorter.

Heating and active energy ray irradiation may be performed alone or in combination. When combined, the order of implementation is not particularly limited.
Heating and active energy ray irradiation are preferably performed in an atmosphere containing no moisture such as a nitrogen gas atmosphere in order to reduce the amount of moisture contained in the layer and / or moisture adsorbed on the surface after implementation. For the same purpose, when combined with heating and / or active energy ray irradiation, it is particularly preferable to perform at least the step immediately before the formation of the light emitting layer in an atmosphere containing no moisture such as a nitrogen gas atmosphere.

The thickness of the hole transport layer is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 100 nm or less.
[Light emitting layer]
When a hole injection layer is provided on the hole injection layer or a hole transport layer, a light emitting layer is provided on the hole transport layer. The light emitting layer is a layer which is excited by recombination of holes injected from the anode and electrons injected from the cathode between the electrodes to which an electric field is applied, and becomes a main light emitting source.

<Light emitting layer material>
The light emitting layer contains at least a material having a light emitting property (light emitting material) as a constituent material thereof, and preferably a compound having a hole moving property (hole transporting material) or an electron moving property. The compound (electron transport material) which has this. There is no particular limitation on the light-emitting material, and a material that emits light at a desired light emission wavelength and has favorable light emission efficiency may be used. Moreover, it is preferable to contain two or more charge transport materials. Furthermore, the light emitting layer may contain other components as long as the effects of the present invention are not significantly impaired. In addition, when forming a light emitting layer with a wet film-forming method, it is preferable to use the material of a monomer amount in any case.

(Luminescent material)
Any known material can be applied as the light emitting material. For example, a fluorescent material or a phosphorescent material may be used, but a phosphorescent material is preferable from the viewpoint of internal quantum efficiency.
For the purpose of improving the solubility in a solvent, it is preferable to reduce the symmetry and rigidity of the molecules of the luminescent material or introduce a lipophilic substituent such as an alkyl group.

Hereinafter, although the example of a fluorescent dye is mentioned among light emitting materials, a fluorescent dye is not limited to the following illustrations.
Examples of fluorescent dyes that give blue light emission (blue fluorescent dyes) include naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis (2-phenylethenyl) benzene, and derivatives thereof.

Examples of fluorescent dyes that give green light emission (green fluorescent dyes) include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al (C ₉ H ₆ NO) ₃ .
Examples of fluorescent dyes that give yellow light (yellow fluorescent dyes) include rubrene and perimidone derivatives.
Examples of fluorescent dyes that give red luminescence (red fluorescent dyes) include DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzoates. Examples thereof include thioxanthene derivatives and azabenzothioxanthene.

As the phosphorescent material, for example, a long-period type periodic table (hereinafter referred to as a long-period type periodic table when referred to as “periodic table” unless otherwise specified) is selected from the seventh to eleventh groups. And an organometallic complex containing a metal.
Preferred examples of the metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

  As the ligand of the complex, a ligand in which a (hetero) aryl group such as a (hetero) arylpyridine ligand or a (hetero) arylpyrazole ligand and a pyridine, pyrazole, phenanthroline, or the like is connected is preferable. A pyridine ligand and a phenylpyrazole ligand are preferable. Here, (hetero) aryl represents an aryl group or a heteroaryl group.

  Specific examples of the phosphorescent material include tris (2-phenylpyridine) iridium, tris (2-phenylpyridine) ruthenium, tris (2-phenylpyridine) palladium, bis (2-phenylpyridine) platinum, tris (2- Phenylpyridine) osmium, tris (2-phenylpyridine) rhenium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, octaphenyl palladium porphyrin, and the like.

  The molecular weight of the compound used as the light emitting material is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 10,000 or less, preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, and usually 100 or more, Preferably it is 200 or more, More preferably, it is 300 or more, More preferably, it is the range of 400 or more. If the molecular weight of the luminescent material is too small, the heat resistance will be significantly reduced, gas generation will be caused, the film quality will be reduced when the film is formed, or the morphology of the organic electroluminescent element will be changed due to migration, etc. Sometimes come. On the other hand, if the molecular weight of the luminescent material is too large, it tends to be difficult to purify the luminescent material, or it may take time to dissolve in the solvent.

In addition, any 1 type may be used for the luminescent material mentioned above, and 2 or more types may be used together by arbitrary combinations and a ratio.
The proportion of the light emitting material in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.05% by weight or more, preferably 0.3% by weight or more, more preferably 0.5% by weight.
In addition, it is usually 35% by weight or less, preferably 25% by weight or less, and more preferably 20% by weight or less. If the amount of the light emitting material is too small, uneven light emission may occur. If the amount is too large, the light emission efficiency may be reduced. In addition, when using together 2 or more types of luminescent material, it is made for the total content of these to be contained in the said range.

(Hole transport material)
The light emitting layer may contain a hole transport material as a constituent material thereof. Here, among the hole transport materials, examples of the monomer-amount hole transport material include various compounds exemplified as (monomer-amount hole transport material) in the above-described hole injection layer, for example, 4 , 4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl, which includes two or more tertiary amines and two or more condensed aromatic rings substituted with nitrogen atoms Aromatic amine compounds having a starburst structure such as diamine (Japanese Patent Laid-Open No. 5-234811), 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine (Journal of Luminescence, 1997, Vol. 72-74, pp. 985), an aromatic amine compound consisting of a tetramer of triphenylamine (Chemical Communication) , 1996, pp. 2175), spiro compounds such as 2,2 ′, 7,7′-tetrakis- (diphenylamino) -9,9′-spirobifluorene (Synthetic Metals, 1997, Vol. 91, pp.). .209) and the like.

In the light emitting layer, only one type of hole transport material may be used, or two or more types may be used in any combination and ratio.
The ratio of the hole transport material in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, Moreover, it is 65 weight% or less normally, Preferably it is 50 weight% or less, More preferably, it is 40 weight% or less. If the amount of the hole transport material is too small, it may be easily affected by a short circuit, and if it is too large, the film thickness may be uneven. In addition, when using together 2 or more types of hole transport materials, it is made for the total content of these to be contained in the said range.

(Electron transport material)
The light emitting layer may contain an electron transport material as a constituent material thereof. Here, among the electron transport materials, examples of the monomer amount electron transport material include 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND) and 2,5-bis. (6 ′-(2 ′, 2 ″ -bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), bathophenanthroline (BPhen), 2,9-dimethyl-4,7-diphenyl -1,10-phenanthroline (BCP, bathocuproine), 2- (4-biphenylyl) -5- (p-tertiarybutylphenyl) -1,3,4-oxadiazole (tBu-PBD), 4,4 '-Bis (9-carbazole) -biphenyl (CBP), etc. In the light emitting layer, only one type of electron transport material may be used, and two or more types may be used in any combination and ratio. It may be used in combination.

The ratio of the electron transport material in the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, The amount is usually 65% by weight or less, preferably 50% by weight or less, and more preferably 40% by weight or less. If the amount of the electron transporting material is too small, it may be easily affected by a short circuit, and if it is too large, the film thickness may be uneven. In addition, when using together 2 or more types of electron transport materials, it is made for the total content of these to be contained in the said range.
(Formation of light emitting layer)
When the light emitting layer is formed by the wet film formation method according to the present invention, a composition for wet film formation is prepared by dissolving the above materials in an appropriate organic solvent, and the film formation process, preferably drying is performed using the composition. It is formed through a process. Details of these steps are the same as those described above. In addition, when forming another organic layer with the wet film-forming method based on this invention, you may use a vapor deposition method or another method for formation of a light emitting layer.

  As the organic solvent for the light emitting layer to be contained in the wet film forming composition for forming the light emitting layer by the wet film forming method according to the present invention, any solvent can be used as long as the light emitting layer can be formed. . However, a material capable of dissolving the light-emitting material, the hole transport material, and the electron transport material is preferable. Specifically, the solubility of the light emitting material, the hole transport material or the electron transport material is usually 0.01% by weight or more, particularly 0.05% by weight or more, and particularly 0.1% by weight at room temperature / normal pressure. It is preferable to dissolve the above.

Suitable examples of the organic solvent for the light emitting layer are the same as those described for the charge transport film composition of the present invention.
The ratio of the organic solvent for the light-emitting layer to the wet film-forming composition for forming the light-emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.01% by weight or more, preferably 0.1%. % By weight or more, more preferably 0.5% by weight or more, and usually 70% by weight or less, preferably 60% by weight or less, more preferably 50% by weight or less. In addition, when mixing and using 2 or more types of organic solvents as an organic solvent for light emitting layers, it is made for the sum total of these organic solvents to satisfy | fill this range.

After the wet film formation of the composition for wet film formation for forming the light emitting layer, the obtained coating film is dried and the organic solvent for the light emitting layer is removed to form the light emitting layer. The method of the wet film forming method is not limited as long as the effect of the present invention is not significantly impaired, and any of the methods described above can be used.
The thickness of the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 3 nm or more, preferably 5 nm or more, and usually 200 nm or less, preferably 100 nm or less. If the light emitting layer is too thin, defects may occur in the film, and if it is too thick, the driving voltage may increase.

[Hole blocking layer]
A hole blocking layer may be provided between the light emitting layer and an electron injection layer described later. The hole blocking layer is a layer stacked on the light emitting layer so as to be in contact with the cathode side interface of the light emitting layer.
The hole blocking layer has a role of blocking holes moving from the anode from reaching the cathode and a role of efficiently transporting electrons injected from the cathode toward the light emitting layer.

  The physical properties required for the material constituting the hole blocking layer include high electron mobility, low hole mobility, large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). It is expensive. Examples of the material for the hole blocking layer satisfying such conditions include bis (2-methyl-8-quinolinolato) (phenolato) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanolato) aluminum, and the like. Mixed metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes, distyrylbiphenyl derivatives, etc. Triazole derivatives such as styryl compounds (JP-A-11-242996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (JP-A-7 -41759), phenanthroline derivatives such as bathocuproine (JP-A-10-79297), and the like. That. Further, a compound having at least one pyridine ring substituted at the 2,4,6-positions described in International Publication No. 2005-022962 is also preferable as a material for the hole blocking layer.

In addition, the material of a hole-blocking layer may use only 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
There is no restriction | limiting in the formation method of a hole-blocking layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods.
The thickness of the hole blocking layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.
[Electron transport layer]
You may provide an electron carrying layer between a light emitting layer and the below-mentioned electron injection layer.

The electron transport layer is provided for the purpose of further improving the light emission efficiency of the device, and can efficiently transport electrons injected from the cathode between the electrodes to which an electric field is applied in the direction of the light emitting layer. Is formed.
The electron transporting compound used for the electron transporting layer is usually a compound that has high electron injection efficiency from the cathode or the electron injection layer and has high electron mobility and can efficiently transport the injected electrons. Is used. Examples of the compound satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadiazole derivatives , Distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compounds ( JP-A-6-207169), phenanthroline derivative (JP-A-5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinonediimine, n-type hydrogenated amorphous silicon carbide , N-type zinc sulfide, n-type Sele Zinc oxide and the like.

In addition, only 1 type may be used for the material of an electron carrying layer, and 2 or more types may be used together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of an electron carrying layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods.

The thickness of the electron transport layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.
[Electron injection layer]
The electron injection layer plays a role of efficiently injecting electrons injected from the cathode into the light emitting layer. In order to perform electron injection efficiently, the material for forming the electron injection layer is preferably a metal having a low work function. Examples include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the film thickness is preferably from 0.1 nm to 5 nm.

  Furthermore, an organic electron transport compound represented by a metal complex such as a nitrogen-containing heterocyclic compound such as bathophenanthroline or an aluminum complex of 8-hydroxyquinoline is doped with an alkali metal such as sodium, potassium, cesium, lithium, or rubidium ( (As described in JP-A-10-270171, JP-A-2002-1000047, JP-A-2002-1000048, etc.), it is possible to improve the electron injection / transport properties and achieve excellent film quality. preferable. In this case, the film thickness is usually 5 nm or more, preferably 10 nm or more, and is usually 200 nm or less, preferably 100 nm or less.

In addition, only 1 type may be used for the material of an electron injection layer, and 2 or more types may be used together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of an electron injection layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods.
[cathode]
The cathode plays a role of injecting electrons into a layer (such as an electron injection layer or a light emitting layer) on the light emitting layer side.

  As the material of the cathode, it is possible to use the material used for the anode, but in order to perform electron injection efficiently, a metal having a low work function is preferable, for example, tin, magnesium, indium, calcium, A suitable metal such as aluminum or silver or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

In addition, only 1 type may be used for the material of a cathode, and 2 or more types may be used together by arbitrary combinations and a ratio.
The thickness of the cathode is usually the same as that of the anode.
Further, for the purpose of protecting the cathode made of a low work function metal, it is preferable to further stack a metal layer having a high work function and stable to the atmosphere because the stability of the device is increased. For this purpose, for example, metals such as aluminum, silver, copper, nickel, chromium, gold and platinum are used. In addition, these materials may be used only by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Other layers)
The organic electroluminescent element according to the present invention may have another configuration without departing from the gist thereof. For example, as long as the performance is not impaired, an arbitrary layer may be provided between the anode and the cathode in addition to the layers described above, and an arbitrary layer may be omitted.
[Electron blocking layer]
Examples of the layer that may be included include an electron blocking layer.

  The electron blocking layer is provided between the hole injecting layer or the hole transporting layer and the light emitting layer, and prevents electrons moving from the light emitting layer from reaching the hole injecting layer. Increases the recombination probability of holes and electrons, and has the role of confining the generated excitons in the light-emitting layer and the role of efficiently transporting holes injected from the hole injection layer toward the light-emitting layer. . In particular, when a phosphorescent material or a blue light emitting material is used as the light emitting material, it is effective to provide an electron blocking layer.

  The characteristics required for the electron blocking layer include high hole transportability, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1). Furthermore, in the present invention, when the light emitting layer is produced by a wet film formation method, the electron blocking layer is also required to be compatible with the wet film formation. Examples of the material used for such an electron blocking layer include a copolymer of dioctylfluorene and triphenylamine typified by F8-TFB (International Publication No. 2004/084260).

In addition, the material of an electron blocking layer may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no restriction | limiting in the formation method of an electron blocking layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods.
Further, at the interface between the cathode and the light emitting layer or the electron transport layer, for example, lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), lithium oxide (Li ₂ O), cesium carbonate (II) (CsCO ₃ ), etc. are formed. It is also an effective method to improve the efficiency of the device by inserting a very thin insulating film (0.1 to 5 nm) (Applied Physics Letters, 1997, Vol. 70, pp. 152; No. 74586; IEEE
Transactions on Electron Devices, 1997, Vol. 44, pp. 1245; SID 04 Digest, pp. 154 etc.).

[Hole relaxation layer]
Examples of the layer that may be included further include a hole relaxation layer.
The hole relaxation layer is a layer formed adjacent to the cathode side of the light emitting layer, and is a layer that functions to relax the accumulation of holes at the interface between the light emitting layer and the hole relaxation layer. It also has a role of efficiently transporting electrons toward the light emitting layer.

In addition, you may have a hole relaxation layer between the said application | coating light emitting layer and the previous vapor deposition light emitting layer.
The ionization potential of the hole relaxation layer is usually 5.5 eV or more, preferably 5.6 eV or more, more preferably 5.7 eV or more, and usually 6.7 eV or less, preferably 6.4 eV or less, more preferably 6.0 eV or less. It is. If the value of the ionization potential is too large or too small, there is a possibility that holes are retained at the interface between the light emitting layer and the hole relaxation layer.

The ionization potential (Ip) can be measured by an ionization potential measuring apparatus PCR-101 (manufactured by Optel).
The thickness of the hole relaxation layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.3 nm or more, more preferably 0.5 nm or more, preferably 100 nm or less, more preferably 50 nm or less. It is. If the film thickness is too thin, defects may occur in the thin film, and if it is too thick, the drive voltage may increase.

The hole relaxation layer is preferably formed by vapor deposition. As the vapor deposition film forming method, a vacuum vapor deposition method, a laser transfer method, a resistance heating method, an electron beam method, PVD (physical vapor deposition), and CVD (chemical vapor deposition) are preferable, and a vacuum vapor deposition method is more preferable.
Although the electron transport layer is usually formed adjacent to the cathode side of the hole relaxation layer, the difference in ionization potential between the hole relaxation layer and the electron transport layer is arbitrary as long as the effect of the present invention is not significantly impaired. , Usually less than 0.5 eV, preferably less than 0.3 eV, more preferably less than 0.2 eV. If the difference in ionization potential is too large, holes may accumulate in the hole relaxation layer and cause deterioration.

Moreover, in the layer structure demonstrated above, it is also possible to laminate | stack components other than a board | substrate in reverse order. For example, in the case of the layer configuration of FIG. 1, the other components on the substrate are in the order of cathode, electron injection layer, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode. It may be provided.

Furthermore, it is also possible to constitute the organic electroluminescent element according to the present invention by laminating components other than the substrate between two substrates, at least one of which is transparent.

Further, a structure in which a plurality of components (light emitting units) other than the substrate are stacked in a plurality of layers (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, instead of the interface layer between the steps (between the light emitting units) (when the anode is ITO and the cathode is Al, these two layers), for example, a charge made of vanadium pentoxide (V ₂ O ₅ ) or the like. When a generation layer (Carrier Generation Layer: CGL) is provided, a barrier between steps is reduced, which is more preferable from the viewpoint of light emission efficiency and driving voltage.

Furthermore, the organic electroluminescent device according to the present invention may be configured as a single organic electroluminescent device, or may be applied to a configuration in which a plurality of organic electroluminescent devices are arranged in an array. You may apply to the structure by which the cathode is arrange | positioned at XY matrix form.
Each layer described above may contain components other than those described as materials unless the effects of the present invention are significantly impaired.

<Organic EL display>
The organic EL display of the present invention uses the organic electroluminescent element of the present invention as described above. There is no restriction | limiting in particular about the model and structure of the organic electroluminescent display of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.
For example, the organic EL display of the present invention is formed by a method as described in “Organic EL Display” (Ohm, published on August 20, 2004, Shizushi Tokito, Chiba Adachi, Hideyuki Murata). can do.

<Organic EL lighting>
The organic EL illumination of the present invention uses the above-described organic electroluminescent element of the present invention. There is no restriction | limiting in particular about the model and structure of the organic EL illumination of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.

EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.
Example 1
First, a substrate in which an indium tin oxide (ITO) transparent conductive film (manufactured by Sanyo Vacuum Co., Ltd., sputtered film) is patterned on a glass substrate in a 2 mm-wide stripe shape is super After washing in the order of sonic cleaning, rinsing with ultrapure water, sonic cleaning with ultrapure water, and rinsing with ultrapure water, they were dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.
(Formation of hole injection layer)
100 parts by weight of a polymer having a repeating structure of the following formula (I) (weight average molecular mass 85,000), 20 parts by weight of a compound represented by the following formula (II), and 5880 parts by weight of cyclohexylbenzene as a solvent, After stirring at room temperature for 3 hours, the mixture was heated on a 100 ° C. hot plate for 3 hours to prepare a hole injection layer coating solution (A1).

A hole injection layer was formed on the cleaned ITO substrate by spin coating using the above-described coating solution for hole injection layer. The spin coating was performed in an air atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, the rotation speed was 2000 rpm, and the rotation time was 30 seconds. After coating, after heating and drying on a hot plate at 80 ° C. for 1 minute, the insoluble portion is wiped off and baked in an oven atmosphere at 230 ° C. for 1 hour. The compound represented by the formula (I) is represented by the following formula (III). This was converted to a compound having a thickness of 27 nm.

(Formation of hole transport layer)
Next, a hole transport layer was formed on the hole injection layer. The hole injection layer-coated substrate was placed in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a moisture concentration of 1.0 ppm, and the hole transport layer coating solution preparation, spin coating, and baking were all performed in the glove box.
A polymer having a repeating structure of the following formula (IV) (weight average molecular mass 95000) was dissolved in cyclohexylbenzene as a solvent to prepare a 1.4% by weight solution to prepare a hole transport layer coating solution.

On the hole injection layer, a hole injection layer was formed by spin coating using the above hole transport layer coating solution. The number of rotations was 1500 rpm, and the rotation time was 120 seconds. After application, the film was pre-dried at 230 ° C. for 10 seconds on a hot plate, and then unnecessary portions on the electrode were wiped off, and then baked on the hot plate at 230 ° C. for 1 hour to form a 27 nm-thick hole transport layer.
(Formation of light emitting layer)
Next, a light emitting layer was formed on the hole transport layer. Preparation of the light emitting layer coating solution, spin coating, and baking were all performed in a nitrogen glove box having an oxygen concentration of 1.0 ppm and a moisture concentration of 1.0 ppm without being exposed to the atmosphere.
(Preparation of luminescent layer coating solution)
100 parts by weight of a compound represented by the following formula (V) and 10 parts by weight of a compound represented by the following formula (VI) are dissolved in cyclohexylbenzene as a solvent to prepare a 4% by weight solution, and a light emitting layer is applied. A liquid was prepared.

(Light-emitting layer coating)
On the hole transport layer, a light emitting layer was formed by spin coating using a light emitting layer coating solution. The rotation speed was 2000 rpm and the rotation time was 120 seconds. After coating, after pre-drying at 130 ° C. for 10 seconds on a hot plate, unnecessary portions on the electrode were wiped off, and then dried by vacuum heating on the hot plate at 130 ° C. for 1 hour to form a light-emitting layer having a thickness of 50 nm. .

The substrate was once taken out into the atmosphere and immediately placed in the chamber of the vacuum deposition apparatus. The chamber was roughed with a rotary pump and then depressurized with a cryopump. The degree of vacuum was 1.0 × 10 ⁻⁴ Pa. A vapor deposition mask was disposed in a predetermined area on the substrate, and necessary vapor deposition materials were previously placed in separate molybdenum boats in the chamber.
(Formation of electron transport layer 1)
A crucible containing a material represented by the following formula (VII) was heated by current application and deposited on the light emitting layer. The degree of vacuum during the deposition was 1.0 × 10 ⁻⁴ Pa, the deposition rate was 0.7 Å / s, and the electron transport layer 1 was formed with a film thickness of 10 nm.

(Formation of electron transport layer 2)
Next, the crucible containing Alq ₃ represented by the following formula (VIII) was heated by current application and deposited on the electron transport layer 1. The degree of vacuum during the deposition was 1.0 × 10 ⁻⁴ Pa, the deposition rate was 1.0 Å / s, and the electron transport layer 2 was formed with a film thickness of 30 nm.

(Cathode formation)
Next, the substrate was once taken out into the atmosphere, and a 2 mm wide striped shadow mask as a mask for cathode vapor deposition was arranged so as to be orthogonal to the ITO ITO stripe of the anode, and immediately placed in the vapor deposition apparatus. The chamber was roughed with a rotary pump and then depressurized with a cryopump. The degree of vacuum was 3.0 × 10 ⁻⁴ Pa. As a cathode, first, a molybdenum boat containing lithium fluoride (LiF) was energized and heated and deposited on the electron transport layer. Deposition conditions were such that the degree of vacuum during deposition was 3.0 × 10 ⁻⁴ Pa, the deposition rate was 0.1 Å / s, and the film thickness was 0.5 nm. Finally, a molybdenum boat containing aluminum was heated by energization to deposit a cathode. Deposition conditions were such that the degree of vacuum during deposition was 4.0 × 10 ⁻⁴ Pa, the deposition rate was 3.0 Å / s, and a film thickness of 80 nm was formed.

(Sealing)
Next, the substrate was once taken out into the atmosphere and immediately transferred to a glove box substituted with nitrogen. In a nitrogen-substituted glove box, a hygroscopic sheet is attached to the concave portion of the sealing glass plate, and a UV curable resin coating is applied around the concave portion of the sealing glass plate with a dispenser. Were sealed so as to be sealed with a sealing glass plate, and UV light was irradiated with a UV lamp to cure the UV curable resin.

As described above, an organic electroluminescent element was obtained.
(Element evaluation)
When this element was energized, uniform blue light emission with no light emission defects was obtained.
When this device was made to emit light at a luminance of 1000 cd / m 2, the current luminous efficiency was 4.63 cd / A.

In addition, when this element was turned on with an initial luminance of 2000 cd / m ² and light was emitted with constant current conduction, the time until the luminance was reduced to half was 600 hours.
(Hole injection layer coating solution static light scattering measurement)
Static hole light scattering measurement is performed on the hole injection layer coating solution (A1), and the value of I _ms / I _m0 when the scattering angle (2θ) is 8 ° and 15 °, and 8 ° ≦ 2θ ≦ 15 ° Table 1 shows the maximum value of I _ms / I _m0 when.

(Example 2)
A device was fabricated in the same manner as in Example 1, except that the hole injection layer coating solution (A1) was changed to the hole injection layer coating solution (A2) prepared as described below. Example 1
In the same manner as above, device evaluation and static light scattering measurement of the coating solution for the hole injection layer were performed.
In preparation of the coating solution for the hole injection layer, 100 parts by weight of the polymer having a repeating structure of the above formula (I), 20 parts by weight of the compound represented by the above formula (II), and 5880 parts by weight of cyclohexylbenzene as a solvent are mixed. And stirred at room temperature for 3 hours.

Next, 1 g of this solution is put in a brown glass bottle, and 31 mW / cm ² of ultraviolet rays is irradiated for about 33 seconds from the opening of the bottle having a diameter of 10 mmφ using an exposure apparatus UX-1000SM-ACS01 (manufactured by USHIO INC.). That is, UV light having a light amount of 1000 mJ / cm ² was irradiated to prepare a hole injection layer coating solution (A2). The light source used in the UX-1000SM-ACS01 is an ultra-high pressure mercury lamp, and the main wavelengths of the irradiated ultraviolet rays are 365 nm (i-line), 405 nm (h-line), and 436 nm (g-line). The operation so far was performed at normal temperature, normal pressure, and normal humidity.

(Element evaluation)
When the obtained device was energized, blue light emission of a uniform light emitting surface free from light emitting defects was obtained.
When this device was made to emit light at a luminance of 1000 cd / m ² , the current luminous efficiency was 4.72 cd / A.

In addition, when this element was turned on with an initial luminance of 2000 cd / m ² and light was emitted with constant current conduction, the time until the luminance was reduced to half was 600 hours.
(Hole injection layer coating solution static light scattering measurement)
Static hole light scattering measurement is performed on the hole injection layer coating solution (A2), and the value of I _ms / I _m0 when the scattering angle (2θ) is 8 ° and 15 °, and 8 ° ≦ 2θ ≦ 15 ° Table 1 shows the maximum value of I _ms / I _m0 when.

(Example 3)
A device was fabricated in the same manner as in Example 2, except that the hole injection layer coating solution (A2) was changed to the hole injection layer coating solution (A3) prepared as described below. Further, in the same manner as in Example 1, element evaluation and static light scattering measurement of the hole injection layer coating solution were performed.
In the preparation of the coating solution for the hole injection layer, the same exposure apparatus UX-1000SM-ACS01 (made by USHIO INC.) As in Example ² was irradiated with 31 mW / cm ² of ultraviolet rays for about 162 seconds from the opening. A hole injection layer coating solution (A3) was prepared in the same manner as in Example 2 except that UV light with a light amount of 5000 mJ / cm ² was irradiated.

(Element evaluation)
When the obtained device was energized, blue light emission of a uniform light emitting surface free from light emitting defects was obtained. The current luminous efficiency when this device was made to emit light at a luminance of 1000 cd / m ² was 4.75 cd / A.
In addition, when this element was turned on with an initial luminance of 2000 cd / m ² and light was emitted with constant current conduction, the time until the luminance was reduced to half was 600 hours.

(Static light scattering measurement of hole injection layer coating solution)
Static hole light scattering measurement was performed on the hole injection layer coating solution (A3), and the value of I _ms / I _m0 when the scattering angle (2θ) was 8 ° and 15 °, and 8 ° ≦ 2θ ≦ 15 ° Table 1 shows the maximum value of I _ms / I _m0 when.
(Comparative Example 1)
A device was fabricated in the same manner as in Example 1, except that the hole injection layer coating solution (A1) was changed to the hole injection layer coating solution (A4) prepared as described below. Further, in the same manner as in Example 1, element evaluation and static light scattering measurement of the hole injection layer coating solution were performed.

In the preparation of the hole injection layer coating solution, a hole injection layer coating solution (A4) was prepared in the same manner as in Example 1 except that heating was not performed on a 100 ° C. hot plate for 3 hours.
(Element evaluation)
When the obtained device was energized, blue light emission was obtained. When the light emitting surface was observed with a microscope, a lot of minute shading unevenness was observed.
When this device was made to emit light at a luminance of 1000 cd / m ² , the current luminous efficiency was 3.82 cd / A.

In addition, when this element was lit at an initial luminance of 2000 cd / m ² and light was emitted with a constant current, the time until the luminance was reduced to half was 300 hours.
(Hole injection layer coating solution static light scattering measurement)
The hole injection layer coating solution (A4) is subjected to static light scattering measurement, and the value of I _ms / I _m0 when the scattering angle (2θ) is 8 ° and 15 °, and 8 ° ≦ 2θ ≦ 15 ° Table 1 shows the maximum value of I _ms / I _m0 when.

(Comparative Example 2)
A device was fabricated in the same manner as in Example 2, except that the hole injection layer coating solution (A2) was changed to the hole injection layer coating solution (A5) prepared as described below. Further, in the same manner as in Example 1, element evaluation and static light scattering measurement of the hole injection layer coating solution were performed.
In preparation of the coating solution for the hole injection layer, the exposure apparatus UX-1000SM-ACS01 similar to that in Example 2 was irradiated with 31 mW / cm ² of ultraviolet light from the opening for about 16 seconds, that is, the light amount was 500 mJ / cm ^2. A hole injection layer coating solution (A5) was prepared in the same manner as in Example 2 except that the UV light was irradiated.

(Element evaluation)
When this element was energized, blue light emission was obtained. When the light emitting surface was observed with a microscope, a lot of minute shading unevenness was observed.
When this device was made to emit light at a luminance of 1000 cd / m ² , the current luminous efficiency was 4.11 cd / A.

In addition, when this element was lit at an initial luminance of 2000 cd / m ² and emitted with constant current, the time until the luminance was reduced to half was 350 hours.
(Hole injection layer coating solution static light scattering measurement)
Static hole light scattering measurement was performed on the hole injection layer coating solution (A5), and the value of I _ms / I _m0 when the scattering angle (2θ) was 8 ° and 15 °, and 8 ° ≦ 2θ ≦ 15 ° Table 1 shows the maximum value of I _ms / I _m0 when.

  From the above results, it can be seen that the organic electroluminescence device having an organic layer formed using the composition for charge transport film of the present invention has a uniform light emitting surface, high luminous efficiency, and long luminance half life.

The composition for a charge transport film of the present invention has high storage stability, can form a film uniformly when forming an organic layer by a wet film formation method, and does not cause a disadvantage from an industrial viewpoint.
In addition, an organic electroluminescent device having an organic layer formed by a wet film formation method using the charge transport film composition of the present invention does not cause a short circuit or a dark spot, and has a long driving life.
Thus, the present invention provides a light source (for example, a copier) utilizing characteristics of various fields in which an organic electroluminescent element is used, for example, a flat panel display (for example, for an OA computer or a wall-mounted television) or a surface light emitter. Can be suitably used in the fields of a light source, a liquid crystal display and a backlight light source of instruments), a display panel, a marker lamp and the like.

1 Substrate
2 Anode
3 Hole injection layer
4 hole transport layer
5 Light emitting layer
6 Hole blocking layer
7 Electron transport layer
8 Electron injection layer
9 Cathode

Claims (14)

A charge transport film composition comprising a polymer having a thermally dissociable soluble group, an electron accepting compound and an organic solvent,
In the static light scattering measurement, the charge transport film composition satisfies the following formula (1) when the scattering angle (2θ) is 8 °.
I _ms / I _m0 ≦ 35 (1)
(In formula (1), I _ms represents the corrected scattering intensity of the charge transport film composition, and is a value calculated as I _ms = I _s × 100 / T _s .
I _m0 represents the corrected scattering intensity of the organic solvent contained in the charge transport film composition, and is a value calculated as I _m0 = I ₀ × 100 / T ₀ .
Also, I _s by a static light scattering measurement, the scattering intensity of the charge transport coating composition,
I ₀ is the scattering intensity of the organic solvent contained in the composition for a charge transport film by static light scattering measurement,
T _s is the transmittance (%) of the charge transport film composition at the light scattering measurement wavelength, measured by transmittance.
T ₀ represents the transmittance (%) of the organic solvent contained in the charge transport film composition at the light scattering measurement wavelength by transmittance measurement. ) The charge according to claim 1, wherein, in the static light scattering measurement, when the scattering angle (2θ) is 8 ° and 15 °, I _ms and I _m0 satisfy the above formula (1). A composition for a transport membrane. In the static light scattering measurement, when the scattering angle (2θ) is 8 ° ≦ 2θ ≦ 15 °, I _ms and I _m0 always satisfy the equation (1), 3. The charge transport film composition according to 2. The polymer having the thermally dissociable soluble group is
The aromatic dissociation-soluble group is bonded to a hydrocarbon ring having an aromatic ring in a repeating unit and bonded to the aromatic ring, according to any one of claims 1 to 3. The composition for charge transport films as described.   The composition for charge transport film according to any one of claims 1 to 4, wherein the thermally dissociable soluble group is a group thermally dissociated by a reverse Diels-Alder reaction.   The composition for charge transport film according to any one of claims 1 to 5, wherein the thermally dissociable soluble group is a group that thermally dissociates at 100 ° C or more and 300 ° C or less.   The charge transport film composition according to claim 1, wherein the thermally dissociable soluble group is an etheno group or a ring containing an ethano group. The composition for a charge transport film according to any one of claims 1 to 7, wherein the polymer contains a structure represented by the following formula (U1) or formula (U2) in a repeating unit. object.

(When the polymer has a structure represented by the formula (U1) or the formula (U2) in the main chain repeating unit, the formula (U1) or the formula (U2) represents a divalent group.
When the polymer has a structure represented by the formula (U1) or the formula (U2) in the side chain, the formula (U1) or the formula (U2) represents a monovalent group, and is represented by X ² and X ⁴ The terminal of the group to be formed is a hydrogen atom.
In formula (U1):
X ¹ and X ² are each independently a divalent aromatic hydrocarbon ring group having 6 to 50 carbon atoms that may have a substituent, or 5 carbon atoms that may have a substituent. Represents a divalent aromatic heterocyclic group of 50 or less.
Ring A ⁰ represents an aromatic ring to which a dissociable group is bonded, and may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. However, since the electrochemical stability is excellent, the charge is locally An aromatic hydrocarbon ring is preferable because it is difficult to be present. The aromatic ring may have a substituent, and the substituents may form a ring directly or via a divalent linking group.
S ¹ , S ² , R ^{41 to} R ⁴⁶ are each independently a hydrogen atom, a hydroxyl group, an alkyl group which may have a substituent, an aromatic hydrocarbon ring group which may have a substituent, An aromatic heterocyclic group which may have a substituent, an aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy which may have a substituent A group, an acyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, an acyloxy group which may have a substituent, It represents an arylamino group which may have a substituent, a heteroarylamino group which may have a substituent, or an acylamino group which may have a substituent.
In the formula (U2),
S ^{11 to} S ¹⁴ , R ^{51 to} R ⁵⁶ , X ³ , X ⁴ and ring B ⁰ are each independently as S ¹ , S ² , R ^{41 to} R ⁴⁶ , X ¹ , X ² and ring A ^0. It is the same as that shown.
n ¹ ~n ⁴ each independently represent an integer of 0 to 5. ) The charge transport film composition according to any one of claims 1 to 8, wherein the polymer having a thermally dissociable soluble group contains a repeating unit represented by the following formula (4).

(In the formula, m represents an integer of 0 to 3,
Ar ³¹ and Ar ³² each independently represent a direct bond, a divalent aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar ^{33 to} Ar ³⁵ each independently represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ³³ and Ar ³⁵ represent a monovalent group, and Ar ³⁴ represents a divalent group.
However, Ar ³¹ and Ar ³² are not simultaneously a direct bond. ) The charge transport film according to claim 1, wherein the electron-accepting compound is selected from the group consisting of compounds represented by any of the following formulas (I-1) to (I-3): Composition.

(In formulas (I-1) to (I-3), R ¹¹ , R ²¹ and R ³¹ each independently represents an organic group bonded to A ^{1 to} A ^{3 through a} carbon atom. R ¹² , R ²² , R ²³ and R ^{32 to} R ³⁴ each independently represents a substituent, and two or more adjacent groups of R ^{11 to} R ³⁴ may be bonded to each other to form a ring.
A ¹ and A ² are elements after the third period (third to sixth periods) of the periodic table, A ³ is an element after the second period (second to sixth periods) of the periodic table, and A ¹ is A ² represents an element belonging to Group 16 of the long-periodic periodic table, and A ³ represents an element belonging to Group 15 of the long-periodic periodic table. .
Z ₁ ^{n1 − to} Z ₃ ⁿ³ each independently represents a counter anion.
n _{1 to} n ₃ are each independently an arbitrary positive integer corresponding to the ionic value of the counter anion Z ₁ ^{n1 − to} Z ₃ ^{n3 −} . )   It is an organic electroluminescent element, The composition for charge transport films as described in any one of Claims 1-10 characterized by the above-mentioned.   In the organic electroluminescent element which has an organic layer arrange | positioned between an anode and a cathode and this anode and a cathode on a board | substrate, at least one layer of this organic layer uses the composition for charge transport films | membranes of Claim 11. An organic electroluminescent device, characterized in that the organic electroluminescent device is an organic layer formed in the above manner.   An organic EL display comprising the organic electroluminescent element according to claim 12.   An organic EL illumination comprising the organic electroluminescent element according to claim 12.

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