HK1128714B - Composition, method for preparing film, and functional element and method for preparing the same - Google Patents

Description

Composition, method for producing film, functional element, and method for producing functional element

This application is a divisional application of PCT application with application number CN00800987.2 (international application date: 3/29/2000), entitled "method for producing composition and film, and functional element and method for producing the same", which is at the state of entry.

Technical Field

The present invention relates to a composition (discharge composition) capable of stable discharge for forming a functional material pattern film by a discharge device, a film production method for forming a uniform film (functional film) by using the composition, a functional element (display element) having a light-emitting material layer formed by using the composition, particularly a functional element (display element) such as an organic EL element suitable for light-emitting display use, and a production method thereof.

Background

Conventionally, patterning of functional materials has been performed by photolithography. Since this method has disadvantages of high cost and complicated process, patterning of a functional material by an ejection device, which is easy and can reduce the cost, has been studied recently. In particular, methods using inkjet printing apparatuses are being studied.

For example, as an example of fine patterning using an inkjet printing apparatus, a color filter for a liquid crystal display is manufactured. This is an example of a color filter which is formed by appropriately discharging red, green, and blue dyes, pigment inks, or the like, respectively, by a printing apparatus having a nozzle for discharging three colors of red, green, and blue inks. The inks used in such manufacturing processes are typically water-soluble polar inks. In such a water-soluble ink, a solvent such as glycerin is often added to prevent clogging of the nozzle due to drying.

For example, a method of forming a light-emitting material by applying ink to a light-emitting material such as an organic fluorescent material and discharging and supplying the ink (composition) onto a substrate by an ink jet method has been employed, and a color display device having a structure in which the light-emitting material layer is sandwiched between an anode and a cathode, particularly an organic EL (electroluminescence) display device using an organic light-emitting material as a light-emitting material has been developed.

Such a color display device (organic EL display device) can be manufactured, for example, as follows.

First, the fluorescent material is dissolved in an appropriate solvent to prepare an ink. This ink (composition) is discharged so as to cover the transparent electrode on the substrate with a transparent electrode as an anode of the organic EL display device. Here, the electrode is formed on one surface, or has a pattern shape such as a rectangular shape or a mosaic shape, and has a structure that can be driven by connecting a power source. Then, the ink solvent is dried to remove the ink solvent, thereby forming a light-emitting material layer, and then a metal having a small work function, for example, a metal such as silver, lithium, calcium, or aluminum is deposited on the light-emitting material layer by a method such as vapor deposition or thermal spraying, thereby forming a cathode. Thus, a display device having a structure in which the light-emitting material layer is sandwiched between an anode and a cathode was obtained.

The conventional pattern forming method by the inkjet printing method has very excellent features such as no plate making, resource saving, and labor saving, but has a disadvantage that it is limited by the material used for the composition (ejection composition).

In the inkjet method, a solvent such as ethanol or water is used as a solvent component of the discharge composition, but a functional material having a non-polarity or weak polarity or a polymer functional material (such as a light-emitting material) is not dissolved in the solvent. Further, there are disadvantages that the functional material cannot be used because of reaction with water and alcohol or decomposition due to alcohol.

Further, when a solvent that dissolves a non-polar material well, such as benzene, toluene, or xylene, is used as a solvent for dissolving a functional material, the solvent has a disadvantage that clogging of the nozzle is likely to occur due to a low boiling point (high vapor pressure) and easy drying. In addition, during ejection or in the process of film formation after ejection, vaporization heat is carried away by volatilization of the solvent, and the temperature of the ejected composition is lowered to promote deposition of the functional material. In addition, when the functional material is a multi-component system, there is a disadvantage that phase separation occurs, resulting in non-uniformity, and the original function of the functional film cannot be fulfilled.

Further, when a material having a low solubility, which cannot be used easily as described above, is forcibly used to increase the concentration of the composition to be discharged, precipitation, clogging, and the like occur. When the concentration is thinned to prevent clogging, there is a disadvantage that it is necessary to eject the functional material several times to exhibit the characteristics of the functional material, and the number of steps is increased.

The invention provides a composition which can be used as a functional material by an ink jet printing method instead of a conventional photolithography method for patterning a functional material, and which comprises a non-polar or weakly polar material and a reactive material that is easily reactive with water.

Yet another object of the present invention is to provide a composition which can prevent clogging at the time of ejection, achieve stable ejection, prevent precipitation of contents during ejection, and further prevent phase separation in film formation after ejection. Another object of the present invention is to provide a method for manufacturing a uniform film (functional film), a functional element (display element) such as an organic EL element, and a method for manufacturing the same.

Disclosure of Invention

The present invention achieves the above object by providing a composition characterized by comprising a functional material and a solvent containing at least one benzene derivative having at least one substituent group in which the total number of carbon atoms of the substituent group is 3 or more.

The invention also provides a method for manufacturing the film, which is characterized by adopting the composition. The present invention also provides a functional element having a light-emitting material layer formed between a first electrode and a second electrode, the light-emitting material layer being formed using the composition, and a method for manufacturing the functional element.

Drawings

The first figure is a perspective view schematically showing the steps of manufacturing an organic EL device, which is a functional thin film and a functional device using the composition of the present invention. The second figure schematically shows a schematic cross-sectional view of a part of the steps for producing an organic EL element as a functional element using the composition of the present invention (substrate formation step to via injection/transport layer formation step). The third figure is a schematic cross-sectional view schematically showing a part of the process for producing an organic EL element as a functional element using the composition of the present invention (light-emitting layer formation process to sealing process).

Detailed Description

The composition and the method for producing the film of the present invention, and the functional element and the method for producing the functional element are described in detail below.

The composition of the present invention is characterized by comprising a functional material and a solvent containing at least one benzene derivative having at least one substituent group in which the total number of carbon atoms is 3 or more.

The phrase "the total number of carbon atoms in the substituent is 3 or more" as used herein means that the total number of carbon atoms (sum) of all the substituents substituted on the benzene derivative is 3 or more. Therefore, for example, even if a methyl group or an ethyl group having 1 or 2 carbon atoms has one substituent, the number of carbon atoms added to other substituents becomes 3 or more, and these are included in the aforementioned benzene derivatives of the present invention.

The benzene derivative used in the composition of the present invention has 1 or more substituents as described above. Such a substituent is not particularly limited as long as the total number of carbon atoms in the whole substituent is 3 or more, and examples thereof include a linear or branched aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and the like, and these hydrocarbon groups may contain a hetero atom such as an oxygen atom, a nitrogen atom, a sulfur atom, and the like. The substituents may be bonded to each other to form a cyclic structure such as a cycloalkane ring.

The total number of carbon atoms of the benzene derivative is 3 or more, but from the viewpoint of further improving the solubility of the nonpolar or weakly polar functional material, it is preferably 3 to12, and more preferably 3 to 6.

The aforementioned benzene derivatives are used in the composition of the present invention as a solvent containing at least it. The solvent may be a single solvent composed of 1 of the above-exemplified benzene derivatives or a mixed solvent composed of two or more of the above-mentioned benzene derivatives, or may be a mixture of the above-mentioned benzene derivatives and a solvent other than the above-mentioned benzene derivatives.

Examples of the solvent other than the benzene derivative include a benzene derivative having 1 or more substituents with a total number of carbon atoms of 2 or less (less than 3) such as xylene and toluene, a benzene compound having no substituents, and a benzene derivative substituted with a substituent having no carbon atom.

The functional material used in the composition of the present invention is not particularly limited, and any material which is nonpolar or weakly polar, or a reactive material which is easily reactive with water may be used. As such a functional material, a material suitable for the use of the present invention can be used, and examples thereof include a light-emitting material such as an organic EL material, a precursor of silica glass, a material for a color filter, a conductive material such as an organic metal compound, a dielectric material, a semiconductor material, and the like, and particularly, an organic EL material, a precursor of silica glass, a material for a color filter are preferable.

The composition of the present invention can be used for various purposes, but is particularly suitable for an ink jet method.

When the composition essentially containing the benzene derivative of the present invention is used, the selectivity of the soluble material is particularly increased, and at least drying during ejection can be prevented to enable stable ejection, and a uniform, homogeneous and fine film (functional film) can be obtained. In order to produce such an excellent film, the composition of the present invention may be discharged and supplied to be applied to a substrate, and then the substrate may be subjected to heat treatment (heating). Specifically, there may be mentioned a method in which the composition of the present invention is discharged from a discharge device and applied to a substrate, and then the substrate is treated at a temperature higher than the temperature at the time of extrusion. The ejection temperature is generally room temperature, and the substrate is heated after ejection. By such a treatment, the content precipitated by the decrease in the solvent volatilization temperature after the ejection is redissolved, and a uniform and homogeneous film can be obtained without phase separation.

The temperature of the heat treatment showed no effect at around room temperature, and the effect was observed at 40 ℃ or higher. If the heating exceeds 200 ℃, the solvent evaporation effect becomes null. Therefore, the heat treatment temperature is preferably 40 to 200 ℃. More preferably, the temperature is 50 to 200 ℃ so that a more uniform and homogeneous functional film can be obtained. By setting the heat treatment temperature in this manner, the following effects can be obtained. In particular, when a composition (ink) is discharged by an ink jet method, it is considered that the solvent vaporizes, the temperature of the ink droplets decreases, and the content precipitates. When the content of the ink is composed of 2 or more components, the content may change from a homogeneous mixing system to a heterogeneous mixing system. In this case, phase separation occurs in the luminescent material, so that chromaticity, luminous efficiency, and the like that can be obtained in a uniform system cannot be obtained. Therefore, by heating the composition in the above temperature range, the content of the composition discharged is redissolved, and the composition has an effect of further homogenizing.

In addition, in the production of the film, not only the heat treatment (heating), but also the pressure reduction, pressurization or a combination of these with heating may be performed as necessary.

For example, as a combination of reduced pressure and heating, it is preferable to remove the solvent under reduced pressure immediately after the heating treatment. The pressure at the time of pressure reduction is preferably 20X 10 in view of obtaining a more uniform and homogeneous functional film^-3mmHg (Torr) or less. By doing so, phase separation of the contents can be prevented when the composition is concentrated. That is, when the re-dissolved content is concentrated, the solvent is removed at once, and the content is uniformly fixed before being made non-uniform, whereby the non-uniformity (phase separation) of the content can be prevented, and the desired emission intensity and chromaticity for the original purpose can be obtained in the formed light-emitting material layer.

The time from the start of the heating process to the start of the pressure reduction is set according to the ejection amount and the characteristics of the material.

The ejection device used when the composition of the present invention is used in the ink jet method for producing the above-mentioned film (functional film) includes an ink jet printer, a dispenser, and the like, and is preferably an ink jet printer.

On the other hand, when the composition of the present invention is used, an excellent functional element such as an organic EL element useful particularly for light emitting display applications can be obtained. Specifically, a display device including a light-emitting material layer formed using the composition of the present invention between a first electrode and a second electrode (preferably, a device including a positive hole injection/transport layer further provided between the first electrode and the light-emitting material layer) can be obtained.

The term "hole injection/transport layer" as used herein means a layer having a function of injecting a hole such as a hole into the interior of the layer and a function of transporting the hole such as a hole into the interior of the layer. The provision of such a hole injection/transport layer is preferable in particular because of improvement in element characteristics such as light emission efficiency and life of the organic EL element.

Further, as the functional element, a so-called multicolor display element which is thin, light, low in power consumption, and high in viewing angle and which uses an organic light-emitting material is exemplified, and for example, a display which has a plurality of pixels in addition to the above-mentioned organic EL element and in which a switching element such as a thin film transistor is provided for each pixel, and the like is exemplified.

In the case of manufacturing a display device as such an excellent functional element, it is preferable to perform the following steps and the like. That is, the composition of the present invention is selectively supplied onto a substrate having a first electrode, and preferably subjected to heating, or reduced pressure, pressurization, or a combination thereof with heating to form a luminescent material layer pattern, and then a second electrode is formed on the luminescent material layer pattern (preferably, a solution containing a polar solvent is used on the substrate having the first electrode, a positive hole injection/transport layer is formed by an ink-jet method, and then the luminescent material layer pattern is formed on the positive hole injection/transport layer, particularly preferably, a solution using a nonpolar solvent is used). Thus, an excellent organic EL device or the like can be obtained.

The luminescent material layer of the functional film using the composition of the present invention in the functional element is preferably formed by the method for producing the film (functional film).

Examples of the polar solvent-containing solution (composition) used for forming the positive hole injection/transport layer include solutions in which a polythiophene derivative such as polyethylene dioxythiophene (ポリユチレンジオキシチオフエン) and a component such as polyvinyl sulfonic acid are mixed with a polar solvent such as α -butyrolactone, N-methylpyrrolidone, 1, 3-dimethyl-2-imidazolidinone or a derivative thereof, and glycol ethers such as carbitol acetate and butyl carbitol acetate. The use of such a polar solvent is preferable because stable ejection can be achieved without clogging of the ejection orifice and the film-forming property is excellent.

The compositions of the invention are described in detail below in terms of preferred embodiments thereof.

First embodiment

The first embodiment of the composition of the present invention is a composition used for forming a functional material pattern film by using a discharge device, which is a composition comprising a functional material and a solvent containing at least a benzene derivative having 1 or more substituents and having a total of 3 or more carbon atoms of the substituents.

According to the present embodiment, a nonpolar or weakly polar functional material can be dissolved well to increase the selectivity of the functional material, and in the case of using a solvent having a relatively low vapor pressure, clogging at the time of solvent ejection can be prevented from occurring and stable ejection can be enabled from the viewpoint of slow drying.

As the solvent suitable for the first embodiment, which contains at least a benzene derivative having 1 or more substituents and in which the sum of the carbon atoms of the substituents is 3 or more, a single solvent such as cumene, cymene, cyclohexylbenzene, dodecylbenzene, diethylbenzene, pentylbenzene, dipentylbenzene, butylbenzene, tetralin, and tetramethylbenzene, or a mixed solvent of these solvents can be considered. Alternatively, xylene, toluene, benzene, etc. may be added to these single solvents or mixed solvents as appropriate. By using a single solvent or a mixed solvent exemplified herein, it becomes possible to dissolve a composition of a non-polar or weakly polar functional material. That is, the selectivity of the material becomes large. Further, by using such a single solvent or a mixed solvent, clogging of pores can be prevented.

The boiling point of the benzene derivative used in the composition of the first embodiment is preferably above 200 ℃. Examples of such solvents include dodecylbenzene, cyclohexylbenzene, tetrahydronaphthalene, dipentylbenzene, and pentylbenzene. By using these solvents, volatilization of the solvents can be further prevented, and is preferable.

As the benzene derivative used in the composition of the first embodiment, dodecylbenzene is preferable. The dodecylbenzene may be a single n-dodecylbenzene or a mixture of isomers.

Such a solvent has a boiling point of 300 ℃ or higher and a viscosity of 6 mPas or higher (20 ℃), and it is not limited to a single solvent, but it is preferable that a solvent other than the single solvent is added to prevent the composition from drying. On the other hand, the viscosity of the solvent other than dodecylbenzene is relatively low, and therefore, the viscosity can be adjusted by adding such a solvent, which is very preferable.

As a functional material suitable for the first embodiment, an organic EL material can be considered. Particularly, an organic EL material made of a nonpolar or weakly polar material is preferable. For example, EL materials composed of (poly) p-phenylene vinylene ((ポリ) パラフエニレンビニレン), polyphenylene (ポリ フ エ ニ レ ン), polyfluorene, and polyvinylcarbazole derivatives, and other low-molecular organic EL materials and high-molecular organic EL materials soluble in benzene derivatives are also conceivable. It is also possible to use, for example, rubrene, perylene, 9, 10-diphenylanthracene, tetraphenylbutadiene, naphthyridone, (ナイルレツド), coumarin 6, quinacridone, polythiophene derivatives, etc. It is also possible to use an electron transporting material or a hole transporting material as a surrounding material of the organic EL display.

In addition to the organic EL material, polysilazane (for example, an oriental flame product), an organic SOG material, and the like, which are frequently used as a precursor of silica glass for an interlayer insulating film of a semiconductor or the like, can be considered as a functional material suitable for the first embodiment.

Further, as a functional material forming the composition of the first embodiment, a material for a color filter is also preferable. As the material for the color filter, various sublimation dyes such as a sumicaka fast red dye B (trade name, dye manufactured by sumitomo chemical), a kayalong fast yellow GL (trade name, dye manufactured by japan chemical industries), a maesalpinian fast brilliant blue-B (trade name, dye manufactured by mitsubishi chemical industries), and the like can be selected.

Further, an organometallic compound may be used as the functional material. Or any functional material may be used as the composition as long as it is dissolved in the solvent.

By using the composition in the first state, a functional film such as a patterning film of a functional material using an ejection device can be produced. The method for producing such a functional film can be carried out according to the method for producing a film described above. That is, the composition of the first embodiment is discharged and supplied to be applied to a substrate, and then the substrate is heat-treated at preferably 40 to 200 ℃. In particular, the first embodiment is more preferable because a more uniform and homogeneous functional film can be obtained by setting the heating temperature to 50 to 200 ℃. In the first embodiment, it is preferable to heat the substrate while applying pressure during the high-temperature treatment. By doing so, volatilization of the solvent upon heating can be delayed, and re-dissolution of the contents becomes more perfect. As a result, a more uniform and homogeneous functional film can be obtained. The pressure during the pressurization is preferably 1520 to 76000mmHg (2 to 100 atm) in order to obtain a more uniform and homogeneous functional film.

For the heat treatment of the composition of the first embodiment, it is preferable to remove the solvent by, for example, reducing the pressure as described above before the composition is completely dried.

As the ejection device suitable for the composition in the first state, an inkjet printing device, a dispenser, and the like can be used, and the inkjet printing device is more preferable because of its fineness and accuracy, and a fine functional film can be produced simply and at low cost by using the inkjet printing device.

By using the composition of the first embodiment, a display device such as an organic EL device useful as the functional element (preferably, a display device in which a positive hole injection/transport layer is provided between the first electrode and the light-emitting material layer) can be obtained as appropriate.

Second embodiment

A second embodiment of the composition of the present invention is a composition containing a solvent including at least dodecylbenzene and at least one fluorene-based polymer derivative of the following compounds 1 to 5. That is, in the second embodiment, in the composition of the present invention, as a solvent suitable for the second embodiment of the present invention, which includes at least a benzene derivative having 1 or more substituents and having a total number of carbon atoms of the substituents of 3 or more, a solvent containing at least dodecylbenzene is used, and as a functional material suitable for the second embodiment, at least one fluorene polymer derivative of the compounds 1 to 5 is used.

This embodiment is more preferable than the first embodiment, and the following results are obtained from the viewpoint of the slow drying property by using a solvent having a low vapor pressure such as dodecylbenzene. That is, it is possible to prevent clogging at the time of solvent ejection and to stably eject the solvent, and it is particularly preferable that a uniform film without phase separation can be obtained by heating and pressurizing or immediately reducing the pressure after heating, which will be described later.

The present embodiment is more preferable than the first embodiment as described above, and therefore, the details described in the first embodiment can be suitably used in places not described in detail below.

Compound 1

Compound 2

Compound 3

Compound 4

Compound 5

The second embodiment is described in detail. The composition of this embodiment is obtained by using dodecylbenzene as a solvent, and when the composition is used as an ink composition for forming a pattern by an ink jet method, the composition exhibits a slow-drying effect of dodecylbenzene, and therefore excessive drying at the time of ejection from an ink head can be prevented, and particularly clogging in the ink head can be prevented. Further, even after the ejection, the ejection material remains in a liquid state on the ejection target material, and there is a possibility that post-treatment such as heating may be performed. Further, the fluorene polymer derivatives (compounds 1 to 5) having the above-mentioned specific structures have high emission intensity when used in combination as a light-emitting material, and have good solubility in dodecylbenzene due to their low polarity, and thus, by combining such a light-emitting material with a solvent, it is possible to perform patterning favorably, particularly as a constituent member of an organic EL display device.

As the solvent for the composition of the second embodiment, various second solvents capable of dissolving the luminescent material may be used in combination in dodecylbenzene. Preferably, a solvent having a boiling point of 140 ℃ or higher is used in combination. As such a second solvent having a boiling point of 140 ℃ or higher, cymene, tetralin, cumene, decahydronaphthalene, durene, cyclohexylbenzene, dihexylbenzene, tetramethylbenzene, dibutylbenzene, and the like can be used. Particularly, a solvent containing a compound having a substituent having 3 or more carbon atoms on the benzene ring is preferably used. Furthermore, solvents having a boiling point of 180 ℃ or higher such as tetralin, 1, 2, 3, 4-tetramethylbenzene, 1, 2, 3, 5-tetramethylbenzene, cyclohexylbenzene, decahydronaphthalene and dibutylbenzene are preferably used. By adding these solvents, the concentration and drying speed of the ink composition can be adjusted. But also has the effect of reducing the high viscosity of dodecylbenzene. Further, a composition using tetralin as the solvent having a boiling point of 180 ℃ has an advantage that the concentration thereof can be concentrated. Further, as the solvent, toluene, xylene, chloroform, carbon tetrachloride, and the like can be used.

As the light-emitting material suitable as the functional material in the second embodiment, in addition to the specific fluorene-based polymer derivative, a (poly) p-phenylene vinylene derivative, a polyphenylene derivative, a polyvinylcarbazole derivative, a polythiophene derivative, a perylene dye, a coumarin dye, a rhodamine dye, a nonpolar or weakly polar material, or the like is preferably used, and other low-molecular organic EL materials and polymer organic EL materials soluble in a benzene derivative may be used. It is also possible to use, for example, rubrene, perylene, 9, 10-diphenylanthracene, tetraphenylbutadiene, naphthyridone (ナイルレツド), coumarin 6, quinacridone, etc. Further, it is possible to suitably use a hole transport material, an electron transport material, or the like constituting the organic EL display device.

Further, as the light-emitting material, a compound (6) having the following structure may be added.

Compound 6

By using the composition of the second embodiment, a display device such as an organic EL device useful as the functional element (preferably, a display device in which a positive hole injection/transport layer is provided between the first electrode and the light-emitting material layer) can be obtained as appropriate in the same manner as in the first embodiment.

In the case of producing the luminescent material layer using the composition according to the second embodiment, for example, after the composition is discharged from the discharge device and applied to the substrate, the substrate is heated at a temperature higher than the temperature at the time of discharge (preferably 40 to 200 ℃ C.). The heat treatment step is preferably carried out at a higher temperature, and when a solvent having a low boiling point is used, drying may be terminated immediately after ejection, and there is a possibility that this step cannot be sufficiently obtained. According to the present embodiment, since dodecylbenzene is used as a high boiling point solvent, the content of the composition discharged by the heat treatment is redissolved and further homogenized, and the above-mentioned effect is extremely great.

The heat treatment of the composition is preferably performed at the same temperature as in the case of the first embodiment. Further, the heat treatment of the composition is preferably performed under pressure as in the first embodiment, and further, in the heat treatment of the composition, it is preferable to remove the solvent by, for example, reducing the pressure before the composition is completely dried.

Third embodiment

The third embodiment of the composition of the present invention is a composition comprising a functional material and a solvent containing at least one benzene derivative having 1 or more substituents, the sum of the carbon atoms of the substituents being 3 or more, and the vapor pressure (room temperature, the same applies hereinafter) being 0.10 to 10 mmHg. That is, the third embodiment is a composition of the present invention, wherein the solvent containing at least a benzene derivative having 1 or more substituents and having a total carbon number of 3 or more is used as the solvent containing at least a benzene derivative having a vapor pressure of 0.10 to 10mmHg, which is suitable for the third embodiment of the present invention.

The present embodiment can dissolve a nonpolar or weakly polar functional material well, and can prevent clogging of a hole when a solvent is ejected, thereby enabling stable ejection, and can prevent precipitation of a content during ejection and phase separation when a film is formed after ejection. In particular, if a solvent having a vapor pressure within the above range is used, the film can be formed in a state of no phase separation at room temperature by the property of accelerating drying, in a state of being difficult to dry to some extent and not causing phase separation of the material.

Examples of the solvent containing at least one benzene derivative having a vapor pressure of 0.10 to 10mmHg used in the composition of the third embodiment include 1, 2, 3, 4-tetramethylbenzene, 1, 2, 3, 5-tetramethylbenzene, cyclohexylbenzene, pentylbenzene, mesitylene, cumene, cymene, diethylbenzene, tetrahydronaphthalene, and decahydronaphthalene, and among them, 1, 2, 3, 5-tetramethylbenzene is particularly preferable.

The benzene derivative is preferably a mixture of at least one benzene derivative having a vapor pressure of 0.10 to 0.50mmHg and at least one benzene derivative having a vapor pressure of 0.50 to 10 mmHg.

Here, the benzene derivative having a vapor pressure of 0.10 to 0.50mmHg is preferably tetramethylbenzene or cyclohexylbenzene.

The benzene derivative having a vapor pressure of 0.50 to 10mmHg is preferably diethylbenzene and/or mesitylene.

The functional material suitable for the composition of the third embodiment is not particularly limited, and for example, the organic EL material, the precursor material of silica glass, and the like can be applied to the present embodiment, and at least one of fluorene polymer derivatives is particularly preferable, and the compounds 1 to 5 used in the composition of the second embodiment are particularly preferable. Therefore, as the functional material used in this embodiment, the light-emitting material described in the foregoing second embodiment as the functional material is suitably used.

In addition, the composition of the third embodiment can provide a specific excellent element by removing the solvent by heating or a combination of heating and reduced pressure after film formation. In this case, the heating temperature is preferably 40 to 200 ℃, particularly preferably 50 to 100 ℃. The pressure at the time of decompression is preferably 20X 10^-3mmHg or less. And after being ejected (after being ejected on the whole surface of the substrate)The droplets may be left as they are or may be formed into a film by heating or a combination of heating and pressure reduction.

By using the composition of the third embodiment, similarly to the first and second embodiments, a display device such as an organic EL device useful as the functional element (preferably, a display device in which a positive hole injection/transport layer is provided between the first electrode and the light-emitting material layer) can be obtained as appropriate.

The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

Examples of the first embodiment

Examples 1 to1

A 0.1 μm polyvinylcarbazole film was formed by a spray coating method by applying a polyvinylcarbazole solution in tetrahydrofuran to the electrode-carrying side surface of the ITO (indium tin oxide) transparent electrode-attached glass substrate. On the film, a 0.1 wt% mixed solution of xylene/tetralin of polyhexylhydroxyphenylvinylene (xylene/tetralin: 1/4, volume ratio) was discharged in a predetermined shape by using an ink jet printing apparatus. Further, aluminum was evaporated thereon.

The wires are led out from ITO and aluminum, ITO is used as an anode, aluminum is used as a cathode, and 10 volts are applied, so that the LED lamp emits light in orange in a specified shape. In the case of ejecting an ink using xylene as a solvent, the drying speed was high and clogging occurred, so that the ink could not be used immediately.

Examples 1 to 2

In a mixed solution of cymene/tetralin (cymene/tetralin) (1/1), a 20 wt% xylene solution of polysilazane (manufactured by eastern process) was prepared at 20% (volume ratio) with respect to the mixed solution. The polysilazane solution thus obtained was ejected by an ink jet device to be fully wetted on a plastic liquid crystal panel surface, and then dried. The reverse side was also treated in the same manner to obtain a double-sided polysilazane film. The plate was placed in a constant temperature and humidity bath at 85 ℃ and 90% for 20 minutes to prepare a silica glass film. After the panel was taken out and dried, the two polarizers were bonded from both sides so as to be orthogonal.

By this method, the amount of polysilazane used is drastically reduced as compared with the sputtering method, and a silica glass film is formed with almost no loss. Also, the gas transmittance of the liquid crystal panel is improved and the life of the liquid crystal panel is also improved.

Examples 1 to 3

In a mixed solution of cymene/tetralin (cymene/tetralin 1/1), a 20 wt% xylene solution of polysilazane (manufactured by eastern process) was prepared at 20% (volume ratio) with respect to the mixed solution. The polysilazane solution thus obtained was discharged onto a silicon substrate on which a semiconductor element and aluminum wiring were formed by an ink jet apparatus, and was coated over the entire surface. After coating, the coating was dried at 150 ℃ for 20 minutes and then baked at 350 ℃ for 2 hours in a steam atmosphere.

As a result, a flat film having almost the same characteristics as those of the spray method can be obtained due to the silica glass action. However, the amount is reduced by about two digits.

Examples 1 to 4

Embodiments of the present invention are described in further detail. As shown in fig. 1, on electrodes divided into ITO (indium tin oxide) transparent electrodes having a mosaic shape and a glass substrate with a bank surrounding the transparent electrodes, the following ejection compositions in which organic EL materials emitting red, green, and blue colors are dissolved are printed by an ink jet printing apparatus arranged in a mosaic shape for each color. The solid content relative to the solvent was 0.4% (w/v). In FIG. 1, 2, 3, 4 and 5 respectively represent a nozzle, a glass substrate, an ITO transparent electrode, a bank (partition wall) and a composition (ink droplet).

Ejection composition

Solvent dodecylbenzene/tetralin (1/1, volume ratio)

Red polyfluorene/perylene dyes (98/2, weight ratio)

Green polyfluorene/coumarin dye (98.5/1.5, weight ratio)

Blue polyfluorene

The substrate obtained by the ejection was heated at 100 ℃ to remove the solvent, and then 2000 angstroms of aluminum was deposited on the substrate by a suitable metal mask.

The wires are led out from ITO and aluminum, ITO is used as an anode, aluminum is used as a cathode, and 15 volts are applied, so that the LED lamp can emit light in red, green and blue in a specified shape. In contrast to the conventional method in which the ink is ejected only in xylene as a solvent, which is a case where the drying speed is high and the clogging occurs, the ink cannot be used immediately. Further, since the substrate is heated after the ejection to re-dissolve the content, the content can be prevented from being separated, and there is no problem in the emission spectrum or the like. When a low boiling point solvent such as xylene is used, drying is started immediately after ejection, and the content precipitates due to removal of vaporization heat, etc., resulting in phase separation and change in emission spectrum, which is not preferable.

If the ITO electrodes are connected to TFT elements, a display similar to a liquid crystal display commonly used at present can be manufactured by organic EL.

Examples 1 to 5

The substrate ejected in the same manner as in examples 1 to 4 was dried at 100 ℃ for 1 minute, and immediately thereafter, the solvent was removed under reduced pressure (2 mmHg). The substrate thus obtained was used to produce a panel and lit up in the same manner as in examples 1 to 4, and the same results as in examples 1 to 4 were obtained.

Examples 1 to 6

The substrates discharged in the same manner as in examples 1 to 4 were placed in a glass bell jar, and nitrogen gas was introduced thereinto to change the internal pressure to 2 atmospheres, followed by drying at 100 ℃ to remove the solvent. The substrate thus obtained was used to produce a panel and lit up in the same manner as in examples 1 to 4, and the same results as in examples 1 to 4 were obtained.

Examples of the second embodiment

Example 2-1

This example produced a color display device.

The steps in this example can also be explained by referring to fig. 1, similarly to the example of the first embodiment. That is, in the structure shown in fig. 1, the ITO transparent electrodes 3 are formed in a dot pattern, are independent of each other, are directly connected to a TFT element (not shown), form a pixel, and can be driven. Banks 4 are formed so as to divide each pixel (dot of the ITO transparent electrode 3) by a boundary portion of each pixel, and a composition (ink composition) 5 ejected from an ejection hole is supplied to and adhered to the ITO transparent electrode spaced by the banks 4. Since the composition uses three-color light-emitting materials, a multicolor light-emitting display can be manufactured.

First, three compositions were prepared by mixing a light-emitting material with a solvent according to the formulation shown in table 1 below as a composition (ink composition). The light-emitting material is selected from the compounds 1 to 5 which are characteristic of the present invention, and further, a compound 6 is used as necessary.

Next, the composition was discharged onto a substrate (TFT substrate) having banks 4 made of polyimide and TFTs provided for each pixel, using an ink jet apparatus. The size of the discharged region (region partitioned by the bank 4) was 30 μm × 30 μm, the pitch was 70 μm, and the composition (ink composition) discharge pitch was 70 μm. The ink can be ejected well without causing clogging in the ink ejection head, and a substrate in which three kinds of inks are arranged in a mosaic shape can be obtained.

TABLE 1

	Luminescent material	Solvent(s)
			R (Red) ink	10.70 g of Compound 20.2 g of Compound 60.1 g	100ml of dodecylbenzene, 100ml of tetralin
G (Green) ink	10.76 g of Compound 20.2 g of Compound 40.04 g	100ml of dodecylbenzene, 100ml of tetralin
			B (blue) ink	10.78 g of Compound 20.15 g of Compound 30.07 g	100ml of dodecylbenzene, 100ml of tetralin

The substrate was heat-treated on a hot plate at 100 ℃ in a nitrogen atmosphere to obtain a light-emitting layer. The thickness of the obtained luminescent layer is 0.08 to 0.1 μm. Further, lithium fluoride (100nm), calcium (100nm), and aluminum (150nm) were sequentially deposited on the light-emitting layer, and the resulting stacked structure was sealed with an epoxy resin to obtain an organic EL display device.

The TFT elements provided on the ITO transparent electrodes (heads) are driven at 10 volts, and thus a desired color (corresponding to the color of the light-emitting layer provided on the pixel) can be displayed on a pixel-by-pixel basis. In particular, the peak ratio (440nm/530nm) of the emission wavelength spectrum of 440nm and 530nm measured for the pixels from which the G ink was ejected was 1.0, and a visually excellent green color was exhibited.

Examples 2 to 2

Three compositions (ink compositions) were prepared by mixing luminescent materials with solvents having compositions shown in the following table 2, and the compositions were discharged onto a substrate (TFT substrate) having banks 4 made of polyimide as shown in fig. 1 by using an ink jet device in the same manner as in example 2-1. The size of the discharged region (region partitioned by the bank 4) was 30 μm × 30 μm, the pitch was 70 μm, and the discharge pitch was 70 μm. The ink can be ejected well without causing clogging in the ink ejection head, and a substrate in which three kinds of inks are arranged in a mosaic shape can be obtained.

TABLE 2

	Luminescent material	Solvent(s)
			R (Red) ink	10.70 g of Compound 20.2 g of Compound 50.1 g	100ml of dodecylbenzene, 100ml of tetralin
G (Green) ink	10.76 g of Compound 20.2 g of Compound 40.04 g	100ml of dodecylbenzene, 100ml of tetralin
			B (blue) ink	Compound 10.78 g20.15 g of compound 30.07 g	100ml of dodecylbenzene, 100ml of tetralin

The substrate was heat-treated on a hot plate at 100 ℃ in a nitrogen atmosphere to obtain a light-emitting layer. The thickness of the obtained luminescent layer is 0.08 to 0.1 μm. Further, lithium fluoride (100nm), calcium (100nm) and aluminum (150nm) were deposited in this order on the light-emitting layer, and the resulting laminate structure was sealed with an epoxy resin to obtain an organic EL display device.

The TFT elements provided on the ITO transparent electrodes (heads) are driven at 10 volts, and a desired color (corresponding to the color of the light-emitting layer provided on the pixel) can be displayed on a pixel-by-pixel basis. But also animation can be displayed. In particular, the peak ratio (440nm/530nm) of the emission wavelength spectrum of 440nm and 530nm measured for the pixel from which the G ink was ejected was 1.0, and a visually excellent green color was exhibited.

Examples 2 to 3

In the same manner as in example 2-1, first, three kinds of compositions (ink compositions) having the compositions shown in table 1 were prepared, and the inks were discharged onto a TFT substrate having banks 4 made of polyimide as shown in fig. 1 by using an ink jet apparatus. The ink jet head can eject ink well without causing clogging.

The substrate was heat-treated on a hot plate at 100 ℃ for 1 minute in a nitrogen atmosphere, and the solvent was immediately removed under reduced pressure (mercury column 1mmHg), whereby a light-emitting layer was obtained. The thickness of the obtained luminescent layer is 0.08 to 0.1 μm. Further, lithium fluoride (100nm), calcium (100nm), and aluminum (150nm) were sequentially deposited on the light-emitting layer, and the resulting stacked structure was sealed with an epoxy resin to obtain an organic EL display device.

The TFT elements provided on the ITO transparent electrodes (heads) are driven at 10 volts, and a desired color (corresponding to the color of the light-emitting layer provided on the pixel) can be displayed on a pixel-by-pixel basis. But also animation can be displayed. In particular, the peak ratio (440nm/530nm) of the emission wavelength spectrum of 440nm and 530nm was 1.8 in the pixel measurement of the ejected G ink, and a more preferable green color was exhibited.

Examples 2 to 4

First, three kinds of compositions (ink compositions) having the compositions shown in table 1 were prepared in the same manner as in example 1, and the inks were discharged onto a TFT substrate having banks 4 made of polyimide as shown in fig. 1 by using an ink jet apparatus. The ink jet head can eject ink well without causing clogging.

The substrate was heat-treated on a hot plate at 100 ℃ for 1 minute in a nitrogen atmosphere of 2 pressures, and the solvent was immediately removed under reduced pressure (mercury column 1mmHg), to obtain a light-emitting layer. The thickness of the obtained luminescent layer is 0.08 to 0.1 μm. Further, lithium fluoride (100nm), calcium (100nm), and aluminum (150nm) were sequentially deposited on the light-emitting layer, and the resulting stacked structure was sealed with an epoxy resin to obtain an organic EL display device.

The TFT elements provided on the ITO transparent electrodes (heads) are driven at 10 volts, and a desired color (corresponding to the color of the light-emitting layer provided on the pixel) can be displayed on a pixel-by-pixel basis. But also animation can be displayed. In particular, the peak ratio (440nm/530nm) of the emission wavelength spectrum of 440nm and 530nm was 2.0 in the pixel measurement of the ejected G ink, and a more preferable green color was exhibited.

Examples 2 to 5

In the composition shown in Table 2-2, 100ml of cyclohexylbenzene was mixed instead of tetralin, and the mixture was mixed with a luminescent material in the same manner as in example 2-1 to prepare three compositions (ink compositions), and the three compositions were discharged onto a TFT substrate having banks 4 made of polyimide by using an ink jet apparatus as shown in FIG. 1. The discharge interval was 70 μm, and a substrate in which three kinds of inks were arranged in a mosaic pattern was obtained.

The substrate was heat treated on a hot plate at 130 ℃ in a nitrogen atmosphere. The thickness of the obtained luminescent material layer is 0.08-0.1 μm, and lithium fluoride (100nm), calcium (100nm) and aluminum (150nm) are sequentially evaporated on the luminescent material layer.

The TFT elements provided on the ITO transparent electrodes (heads) are driven at 10 volts, and a desired color (corresponding to the color of the light-emitting layer provided on the pixel) can be displayed on a pixel-by-pixel basis. But also animation can be displayed.

Examples 2 to 6

Three kinds of compositions (ink compositions) were prepared in the same compositions as in examples 2 to 5, and the inks were discharged onto a TFT substrate having banks 4 made of polyimide as shown in fig. 1 by using an ink jet device in the same manner as in examples.

The substrate was heat-treated on a hot plate at 180 ℃ for 1 minute in a nitrogen atmosphere of 2 atmospheres, and immediately after that, the solvent was removed under reduced pressure (1mmHg) to obtain a luminescent material layer. The thickness of the obtained luminescent layer is 0.08 to 0.1 μm. Further, lithium fluoride (100nm), calcium (100nm), and aluminum (150nm) were sequentially deposited on the light-emitting layer. The periphery of the resulting laminated structure was sealed with an epoxy resin to obtain an organic EL display device.

When the TFT elements provided on the ITO transparent electrodes (heads) are driven with 10 v, a desired color (corresponding to the color of the light-emitting layer provided on the pixel) can be displayed for each pixel. But also animation can be displayed.

Comparative example 2-1

A composition (ink composition for R (red)) containing a light-emitting material in accordance with a solvent was prepared in the composition shown in table 3 below, and ejection was attempted on a substrate (TFT substrate) having banks 4 made of polyimide as shown in fig. 1 by using an ink jet device in the same manner as in example 2-1. However, clogging occurs in the ink jet head, and the light emitting layer cannot be formed on the substrate.

TABLE 3

	Luminescent material	Solvent(s)
			R (Red) ink	70.98 g of Compound 80.02 g	Xylene (200 ml)

The light-emitting material compounds 7 and 8 used in this example are compounds having the following structures.

Compound 7

Compound 8

Examples of the third embodiment

Example 3-1

First, as compositions, compositions 1 to 6 (three types of R (red), G (green), and B (blue) were prepared by blending a polymer compound of a functional material (light-emitting material) and a solvent according to the formulations shown in tables 4 to 9 below. The polymer compound is selected from compounds 1 to 5 which are particularly suitable as the functional material in the third embodiment.

TABLE 4 (composition 1)

TABLE 5 (composition 2)

TABLE 6 (composition 3)

TABLE 7 (composition 4)

TABLE 8 (composition 5)

TABLE 9 (composition 6)

The vapor pressure (room temperature) of the solvents used in compositions 1 to 6 was as follows.

Xylene 13.80

Mesitylene 1.73

1, 2, 3, 4-Tetramethylbenzene 0.23

Diethyl benzene 0.70

Cyclohexylbenzene 0.193

Dodecyl benzene 0.0000125

The above compositions were evaluated for solution stability, ejection property and phase separation according to the following criteria. The evaluation results are shown in table 10.

Solution stability: evaluation was made by observing whether or not precipitation (change in turbidity) was visible when the mixture was left at room temperature for two or more days from the preparation. In addition, a change in haze at 650nm was observed for the G, B composition and a change in haze at 700nm was observed for the R composition.

O: no turbidity change (clear solution)

X: turbidity change (with precipitation)

Ejection property: the flight of the composition (ink) droplets from the piezo-driven ink jet head (MJ-930C, manufactured by エプソン) was observed.

Very good: is excellent.

O: good (somewhat curved in flight, but patterned).

X: causing flight bending and plugging of the hole.

Phase separation: after patterning of R, G, B each color, the PL or EL emission spectra of the naturally dried film was evaluated.

O: the short wavelength spectrum from compound 1 was not observed.

X: a short wavelength spectrum from compound 1 can be observed.

Watch 10

However, in the composition 6, the phase separation was changed to ". smallcircle" when the composition was subjected to heat treatment or heat treatment under pressure after ejection, as in the conditions of examples 2-1 to 2-6.

Examples 3 to 2

Substrate formation

A substrate having the pixel shown in fig. 2(a) was formed as follows. On the substrate 11 with TFT, ITO12 and SiO were formed by photolithography₂13 and polyimide 14 are patterned. Such SiO₂And polyimide is a part constituting a bank (dam). At this time, in SiO₂A round opening portion of phi 28 μm was provided thereon, and further, a round opening portion of phi 32 μm was provided on the polyimide thereon, thereby forming a round pixel 15 composed of these two opening portions. This pixel pitch a is 70. 5 μm. By SiO₂And the circular pixels spaced by polyimide are components formed by applying a composition containing an organic EL material to be described later by an ink jet method.

Plasma treatment of substrates

Then, O is performed in the direction of the arrow in FIG. 2(B) on the substrate on which the circular pixels are formed₂And CF₄Continuous atmospheric plasma treatment. Such plasma treatment conditions are as follows. That is, the power was set to 300W and the electrode-substrate distance was set to 1mm under atmospheric pressure. And, for O₂Plasma of O₂The gas flow rate was set to 80ccm, the helium gas flow rate was set to 10L/min, the tape transport speed was set to 10mm/s, and for CF₄Plasma of CF₄The gas flow rate was set to 100cm, the helium gas flow rate was set to 10L/min, and the tape transport speed was set to 5 mm/s.

Ink-jet method for forming a positive hole injection/transport layer

The compositions having the compositions shown in table 11 were prepared into ink compositions for a positive hole injection/transport layer.

TABLE 11

Material	Content (wt%)
		Mixed liquid of polyethylene dihydroxy thiophene/polyvinyl sulfonic acid	11.08
Polyvinyl sulfonic acid	1.44
		Isopropanol (I-propanol)	10
N-methyl pyrrolidone	27.48
		1, 3-dimethyl-2-imidazolidinone	50

As shown in FIG. 2C, the ink composition 17 for the positive hole injection/transport layer was discharged at 20pl from an ink jet head (head MJ-930C manufactured by エプソン Co.) 16, and applied and patterned on each pixel electrode. After the coating, the solvent was removed in vacuum (ltorr) at room temperature for 20 minutes, and then heat-treated in the atmosphere at 200 ℃ (on a hot plate) for 10 minutes, thereby forming the positive hole injection/transport layer 18 (see fig. 2 (D)). The thickness of the obtained positive hole injection/transport layer 18 was 40 nm.

Formation of light-emitting layer by ink-jet method

As shown in fig. 3E and F, composition 2 of table 5 used in example 3-1, which was a light-emitting composition 19, was discharged at 20pl from an ink jet head (head MJ-930C manufactured by エプソン), and was applied by patterning on each pixel electrode in the order of B, R, G, thereby forming light-emitting layers 20 of the respective colors (see fig. 3G). After the light-emitting layer 20 was formed, the substrate was baked at 60 ℃ for 30 minutes under a reduced pressure of not more than lTorr.

Electrode sealing step

After the light-emitting layer was formed, lithium fluoride (thickness: 2nm), calcium (thickness: 20nm) and aluminum (thickness: 20nm) were formed by vapor deposition to prepare an electrode (cathode) 21. Finally, the electrodes are sealed with an epoxy resin 22 to produce the color organic EL panel 10 (see fig. 3H).

Examples 3 to 3

Color organic EL panels were produced by the same procedure as in example 3-2, except that light-emitting layers of the respective colors were formed using composition 3 of table 6 used in example 3-1.

Examples 3 to 4

Color organic EL panels were produced by the same procedure as in example 3-2, except that light-emitting layers of the respective colors were formed using composition 4 of table 7 used in example 3-1.

Examples 3 to 5

Color organic EL panels were produced by the same procedure as in example 3-2, except that light-emitting layers of the respective colors were formed using composition 5 of table 8 used in example 3-1.

Industrial applicability of the invention

As described above, the composition of the present invention can be used in an inkjet printing method instead of a conventional photolithography method for patterning a functional material, and a material having a non-polarity or weak polarity or a material having reactivity with water can be used as a functional material, thereby preventing clogging at the time of ejection, achieving stable ejection, and preventing precipitation of contents during ejection and phase separation at the time of film formation after ejection.

The functional film of the present invention is a uniform, homogeneous and fine film formed by using the composition. The display device of the present invention is a display device provided with a light-emitting material layer formed using the composition, and is particularly suitable for use in an organic EL element or the like for light-emitting display applications.

In addition, by the method for manufacturing a display device of the present invention, an arrangement of films having different functions can be easily obtained. On the other hand, since a necessary amount of material is used in a necessary portion, the amount of material can be reduced as compared with a method such as a spray coating method.

Claims (7)

1. A method for producing an organic electroluminescent element, wherein a composition is selectively supplied onto a substrate having a first electrode to form a luminescent material layer pattern, and then a second electrode is formed on the luminescent material layer pattern, thereby producing an organic electroluminescent element,

composition I: the organic BL material is composed of at least one solvent containing benzene derivatives which have more than one substituent and the total number of carbon atoms of the substituent is more than 3, wherein the boiling point of the benzene derivatives is more than 200 ℃;

composition II: the organic EL material is composed of a solvent containing at least one benzene derivative having at least one substituent and the total number of carbon atoms of the substituent is more than 3, and the organic EL material, wherein the solvent containing at least one benzene derivative contains other solvents with the boiling point of more than 140 ℃;

composition III: the organic EL material is composed of a solvent containing at least one benzene derivative which has more than one substituent and the total number of carbon atoms of the substituent is more than 3, and the organic EL material, wherein the solvent containing at least one benzene derivative contains other solvents with the boiling point of more than 180 ℃;

composition IV: the organic EL material is composed of at least one solvent containing benzene derivatives which have more than one substituent and the total number of carbon atoms of the substituent is more than 3, and the organic EL material, wherein the vapor pressure of the benzene derivatives at room temperature is 0.10-10 mmHg, and the benzene derivatives are 1, 2, 3, 4-tetramethyl benzene;

composition V: the organic EL material is composed of a solvent containing at least one benzene derivative which has more than one substituent and the total number of carbon atoms of the substituent is more than 3, and an organic EL material, wherein the vapor pressure of the benzene derivative at room temperature is 0.10-10 mmHg, and the benzene derivative is a mixture of at least one benzene derivative with the vapor pressure of 0.10-0.50 mmHg and at least one benzene derivative with the vapor pressure of 0.50-10 mmHg; or

Composition VI: comprising a solvent containing at least one benzene derivative having at least one substituent and having 3 or more total carbon atoms, and an organic EL material, wherein the organic EL material is at least one fluorene polymer derivative, and the fluorene polymer derivative is a compound of the following compounds 1 to 4,

compound 1

Compound 2

Compound 3

Compound 4.

2. The method of manufacturing an organic electroluminescent element according to claim 1, wherein the organic electroluminescent element is obtained by forming a hole injection/transport layer on the substrate having the first electrode by an ink-jet method using a solution containing a polar solvent, and then forming a pattern of the luminescent material layer on the hole injection/transport layer.

3. The method for producing an organic electroluminescent element according to claim 1, wherein the benzene derivative is dodecylbenzene in the composition I.

4. The method for producing an organic electroluminescent element according to claim 1, wherein in the composition II, the benzene derivative is dodecylbenzene, and the other solvent having a boiling point of 140 ℃ or higher is at least one selected from the group consisting of cymene, tetralin, cumene, decalin, durene, cyclohexylbenzene, dihexylbenzene, tetramethylbenzene and dibutylbenzene.

5. The method for producing an organic electroluminescent element as claimed in claim 1, wherein the benzene derivative having a vapor pressure of 0.10 to 0.50mmHg in the composition V is tetramethylbenzene.

6. The method for producing an organic electroluminescent element as claimed in claim 1, wherein the benzene derivative having a vapor pressure of 0.10 to 0.50mmHg in the composition V is cyclohexylbenzene.

7. The method for producing an organic electroluminescent element according to claim 1, wherein the benzene derivative having a vapor pressure of 0.50 to 10mmHg in the composition V is diethylbenzene and/or mesitylene.