JPH1012384A - Organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element requiring few manufacturing processes capable of easily achieving a large area and improved in electroluminescent luminance by using a polymer compound soluble in various solvents and capable of easily forming a thin film with no pin hole. SOLUTION: This electroluminescence element is provided with a thin film containing a polymer compound obtained by polymerizing a compound expressed by a formula between opposite electrodes of which at least one electrode is crystal or semi-crystal. In addition, electron ray irradiation is applied to this thin film layer. In the formula, L denotes a dihybrid link group, R denote a hydrogen atom, an alkyl group, an allyl group, a cyclic ester group, a non-cyclic ester group, a cyclic ether group, and an non-cyclic ether group. A denotes a complex cycle. N is 1 or 2, and R may be identical or different when n is 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organic electroluminescence device, and more particularly to an organic electroluminescence device using a polymer obtained by polymerizing a heterocyclic compound having a specific side chain. It is.

[0002]

2. Description of the Related Art Conventionally, an inorganic fluorescent material such as ZnS has been used as an electroluminescent element, and is used for a planar light source for a backlight of a liquid crystal display, a display device such as a flat panel display, and the like. However, it required an AC high voltage to emit light. On the other hand, focusing on the high fluorescence efficiency of organic compounds, research on electroluminescent devices using organic compounds has been carried out for a long time. For example, W.S. Helflish, D.M.
Williams et al. Have obtained blue light emission using an anthracene crystal [“Journal of Chemical Physics”, Vol.
2 (1966)]. Also Vincent, Barl
ow et al. have manufactured a light-emitting device in which a condensed polycyclic compound is formed by a vacuum evaporation method ["Thin Solid Films", Vol. 99, p. 171 (1982)]. However, in each case, a high voltage was required, and the emission intensity was low.

In recent years, Eastman Kodak C.I. W. T
ang et al. used a metal such as magnesium having a small work function as an electron injection electrode, an organic fluorescent dye as a light emitting layer,
Using a triphenyldiamine derivative as a hole transport layer, an organic electroluminescent device in which these were laminated was fabricated, and an electroluminescent device capable of emitting light at a low direct current voltage was fabricated [Journal of Applied Physics Letter (J .Appl.Phy
s. Lett. Vol. 51, p. 913 (1987)
Year)]. As inspired by this, research and development of organic electroluminescent devices using low molecular weight compounds are being actively conducted.

On the other hand, as an organic electroluminescence device using a polymer compound, a device using poly (p-phenylenevinylene) or poly (alkylthiophene) has been studied [“Japanese Journal of Applied”.・ Physics (Jpn. J. App
l. Phys. 30) 1938 (1991)
Year)].

[0005] The organic electroluminescence element is driven at a lower voltage than the inorganic electroluminescence element.
Many attempts have been made on device structures, organic fluorescent dyes, organic charge transport materials, and the like because of high brightness and easy diversification of emission colors.

The electron beam has been used for pattern processing, resist formation, surface treatment of various base materials, and the like. Above all, when a polymer compound is irradiated with an electron beam, the polymer is excited by the electron beam, depending on the intensity of the electron beam,
Cross-linking between molecules and breaking of molecular chains occur. This phenomenon is applied to processing and surface treatment.

[0007]

However, most of the organic electroluminescent devices reported so far have a light emitting layer, a hole transport layer, an electron transport layer, and the like. Most of the organic compounds obtained are low molecular compounds, and in order to form a thin film, it is necessary to vacuum-deposit the compounds forming each layer,
There is a problem that a manufacturing process becomes complicated to obtain a large-area thin film without pinholes.

The present invention has been made in view of such a problem, and an object thereof is to provide a polymer compound which is easily soluble in many solvents and can easily form a pinhole-free thin film. It is an object of the present invention to provide an organic electroluminescent device which can be manufactured with a small number of manufacturing steps, can easily achieve a large area, and has improved electroluminescence luminance.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve this problem, and as a result, have found that a large-area thin film having no pinholes, which is easily soluble in organic solvents such as chloroform and tetrahydrofuran. Using a polymer compound obtained by polymerizing a compound represented by the following general formula (I) which is easily obtained, a thin film layer containing the polymer compound is opposed to at least one of which is transparent or translucent by an appropriate method. It has been found that a large-area organic electroluminescence device can be easily manufactured by forming the device between the electrodes. In addition, after forming the thin film layer on one of the opposing electrodes at least one of which is transparent or translucent by an appropriate method, the thin film layer is irradiated with an electron beam before the other electrode is provided. As a result, the present inventor has found that an organic electroluminescence device having improved electroluminescence luminance can be manufactured, and the present invention has been completed.

[0010]

Embedded image

In the formula (I), L represents a divalent linking group;
Represents a hydrogen atom, an alkyl group, an aryl group, a cyclic ester group, a non-cyclic ester group, a cyclic ether group, or a non-cyclic ether group. A represents a heterocyclic ring. n is 1 or 2, and when n is 2, R may be the same or different.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the organic electroluminescence device of the present invention will be described in detail.

The compound represented by formula (I) used in the present invention will be described in more detail. A represents a heterocyclic ring, preferably thiophene, furan or pyrrole, and particularly preferably thiophene. L represents a divalent linking group;
Examples of the valent linking group include an alkylene group and —C (O) CH ₂
—, —C (O) NR ¹ — (R ¹ represents an alkyl group),
-C (O)-and-(O) S (O)-are preferred. Particularly preferably, an alkylene group is preferred. R represents a hydrogen atom, an alkyl group, an aryl group, a cyclic ester group, a non-cyclic ester group, a cyclic ether group, a non-cyclic ether group, and as the cyclic ester group, β-lactone, γ-lactone, δ
-A substituent containing a lactone or the like is preferable. The acyclic ester _{group, -C (O) OC p H} 2p + 1 (p is an integer of from 1 to 25.) Is preferred. As the cyclic ether group, a substituent containing oxirane, oxolane, furan, or dioxane is preferable. The non-cyclic ether group, -OC _t H _{2t +} 1 ether group (t is representing. An integer from 1 to 25) represented by, -C _u H _2u OC _v H
_{2v + 1} (u represents an integer from 1 to 5, v is 1 to 25
Represents an integer up to. ) Is preferred. Particularly preferred are alkyl groups, and particularly preferred are straight-chain alkyl groups, and particularly preferred are those having 1 to 25 carbon atoms.

Among the compounds represented by the general formula (I) used in the present invention, a particularly preferred compound is a thiophene compound having a substituent at the 3-position and / or 4-position. Substituents containing an alkylcarbamoyloxy bond are preferred.

A thiophene compound having a substituent containing an N-alkylcarbamoyloxy bond at the 3- and / or 4-position can be obtained, for example, by reacting 2- (3'-thienyl) ethanol with an alkyl isocyanate. Examples of the alkyl isocyanates include propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, heptyl isocyanate, octyl isocyanate, nonyl isocyanate, decyl isocyanate, dodecyl isocyanate,
In addition to linear alkyl isocyanates such as octadecyl isocyanate and docosyl isocyanate, aliphatic cyclic isocyanates such as cyclohexyl isocyanate may be used. Also, 2- (3'-thienyl)
In addition to ethanol, 3- (3'-thienyl) propanol, 4- (3'-thienyl) butanol, 3,4-bis (hydroxymethyl) thiophene, 3,4-bis (2-
A thiophene derivative having a hydroxyl group at a terminal and bonded to a thiophene ring by a methylene chain, such as (hydroxyethyl) thiophene, can also be used.

As a method for polymerizing or copolymerizing the thiophene derivative, there are an electrolytic oxidation polymerization method and a chemical oxidation polymerization method. In the present invention, the chemical oxidation polymerization method is preferably used. Examples of the catalyst for chemical oxidation polymerization include compounds known as Lewis acids such as aluminum chloride, iron chloride, molybdenum chloride, tungsten chloride, tin chloride, antimony chloride and arsenic pentafluoride. Among these, those having no oxidizing power such as aluminum chloride or those having weak oxidizing power may be used together with oxidizing agents such as copper chloride, manganese dioxide, and oxygen.

The amount of the catalyst may be changed according to the amount of the thiophene derivative used in the reaction. If the amount is too small, the polymerization hardly proceeds, and if the amount is too large, the undoping becomes difficult. Generally, the amount of the thiophene derivative and the amount of the catalyst are 1: 1 in molar ratio.
To 1:20, preferably 1: 2 to 1:15.

Examples of the solvent used for chemical oxidative polymerization include halogen solvents such as chloroform and dichloroethane;
Aromatic solvents such as nitrobenzene and dichlorobenzene can be used, and these may be used alone or in combination of two or more.

The polymerization can be carried out by dissolving the thiophene derivative in a halogen-based solvent such as chloroform or dichloroethane, and then adding the above catalyst. Optimization of the reaction conditions can be performed by changing the reaction temperature, the amount and the addition rate of the catalyst, the amount of the solvent, and the like. In order to obtain a highly soluble polythiophene derivative with less cross-linking reaction between polymer compounds, it is preferable to carry out the reaction at a temperature lower than room temperature and gradually add a catalyst.

The polymer compound after the completion of the chemical oxidation polymerization is generally in a doped state and has conductivity as it is, but has poor solubility. In order to improve the solubility in an organic solvent such as chloroform, it is necessary to reduce the polymer by undoping. Dedoping can be easily performed by reducing these polymer compounds with water or the like, but generally, a trace amount of a polymerization catalyst may remain. For complete undoping, a reducing agent such as hydrazine may be used as necessary.

The solvent used for forming the thin film containing the polymer compound used in the present invention includes halogen-based solvents such as dichloromethane, dichloroethane, trichloroethane, chloroform, carbon tetrachloride, chlorobenzene, dichlorobenzene, nitrobenzene and the like. Aromatic solvents, cyclic ether solvents such as dioxane, dioxolan, and tetrahydrofuran, and aprotic polar solvents such as dimethyl sulfoxide, dimethylformamide, and N-methylpyrrolidone, but are not limited thereto.

In the present invention, a method for forming a thin film layer on a conductive substrate can be obtained by applying a solution obtained by dissolving the polymer compound used in the present invention in a solvent and drying it. . Examples of the coating method include, but are not limited to, a dip coating method, a spin coating method, a spray coating method, and a curtain coating method.

The organic electroluminescent device of the present invention basically has a structure in which a thin film layer containing at least the polymer compound used in the present invention is sandwiched between a pair of electrodes (anode and cathode). Can be The polymer compound serves as both a light-emitting layer and a charge (hole and electron) transport layer in a single layer, but if necessary, a light-emitting layer, a hole transport layer, and an electron transport layer may be interposed. A fluorescent compound may be added to the compound layer.

At least one of the pair of electrodes used in the organic electroluminescence device of the present invention is a transparent or translucent electrode. Examples thereof include indium tin oxide (ITO) and tin oxide (NES).
A) An electrode formed by forming Pd, Pt, Au, Ag, Cu, or the like on a glass or transparent film by vacuum evaporation, sputtering, plating, or the like.

The thickness of the thin film layer is from 5 nm to 5 nm.
0 μm, preferably 10 nm to 10 μm. Further, the thickness of the light emitting layer used as needed,
0.1 nm to 1 μm, preferably 1 nm to 0.1
μm, and the thickness of the hole transport layer is 0.5 nm.
To 5 μm, preferably 5 nm to 0.5 μm, and the thickness of the electron transport layer is 0.2 nm to 2 μm.
m, preferably from 2 nm to 0.2 μm.

Among the pair of electrodes used in the organic electroluminescence device of the present invention, the electrode serving as the electron injection cathode is not particularly limited, but a material having a small work function is preferable. For example, Ca, Mg, In, A
1, Ag, Mg-Ag alloy, Mg-In alloy, Mg-A
1 alloy and the like.

The accelerating voltage of the electron beam used in the present invention is 1
00 to 1000 kV, preferably 150 to 350 kV.
kV, and the absorbed dose is 0.1 to 20 Mrad, preferably 1 to 15 Mrad. As the electron beam accelerator, for example, an electro curtain system, a scanning type, a double scanning type, or the like is used, but is not limited thereto.

The atmosphere for electron beam irradiation in the present invention may be air, but it is preferable that the atmosphere is replaced with an inert gas such as nitrogen, helium or carbon dioxide.

[0029]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Synthesis Example (1) 3.74 g of n-propyl isocyanate and 5.13 g of 2- (3-thienyl) ethanol were mixed at 110 ° C.
Stir for hours. 30 ml of hexane is added to the reaction solution, which is further refluxed for 1 hour. After allowing the reaction solution to cool,
Further, 20 ml of hexane was added, and the mixture was cooled. The lower phase of the reaction solution separated into two phases was taken out, refluxed three times with hexane, and then hexane was removed with a rotary evaporator to obtain 1- (N-propylcarbamoyloxy). -2-
(3'-thienyl) ethane was obtained. After dissolving 1.0 g of the obtained monomer in 50 ml of chloroform,
Under a nitrogen gas atmosphere, 5.0 g of anhydrous ferric chloride was added, and the mixture was stirred for 24 hours to perform chemical oxidation polymerization. After completion of the reaction, 500 ml of chloroform was added to the reaction solution, and then 10
Pour into 00 ml of deionized water and mix well.
Thereafter, only the chloroform phase was taken out using a separatory funnel, and washing with deionized water was further repeated.When the deionized water phase was no longer colored by iron ions or the like, the chloroform phase was separated and chloroform was removed using a rotary evaporator. After removal, drying under vacuum gave poly {3- [2- (N-propylcarbamoyloxy) ethyl] thiophen-2,5-diyl}. When the molecular weight of this polymer was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 5,500 and the weight average molecular weight (Mw) was 13,000 in terms of polystyrene.

Synthesis Example (2) 4.36 g of n-butyl isocyanate and 5.13 g of 2- (3-thienyl) ethanol are mixed and stirred at 120 ° C. for 2 hours. 50 ml of hexane is added to the reaction solution, which is further refluxed for 1 hour. After allowing the reaction solution to cool,
The lower phase of the reaction solution separated into two phases was taken out, 50 ml of hexane was added thereto, and the mixture was cooled with ice. The precipitated crystals were collected by filtration, and the crystals were recrystallized three times from hexane. Drying was performed under reduced pressure to obtain 1- (N-butylcarbamoyloxy) -2- (3′-thienyl) ethane. After dissolving 1.0 g of the obtained monomer in 50 ml of chloroform, 5.0 g of anhydrous ferric chloride was added under a nitrogen gas atmosphere, and the mixture was stirred for 24 hours to perform chemical oxidation polymerization. After the reaction is completed, add 500
After adding ml, the mixture was poured into 1000 ml of deionized water and sufficiently stirred. Thereafter, only the chloroform phase was taken out using a separatory funnel, and washing with deionized water was further repeated.When the deionized water phase was no longer colored by iron ions or the like, the chloroform phase was separated and chloroform was removed using a rotary evaporator. After the removal, the product is dried under vacuum to obtain poly {3- [2- (N-butylcarbamoyloxy) ethyl] thiophene-2,5-
Jill｝ was obtained. When the molecular weight of this polymer was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 5 in terms of polystyrene.
000 and the weight average molecular weight (Mw) was 12,000.

Synthesis Example (3) 5.59 g of n-hexyl isocyanate and 5.13 g of 2- (3-thienyl) ethanol were mixed at 140 ° C.
Stir for hours. 50 ml of hexane is added to the reaction solution, which is further refluxed for 1 hour. After allowing the reaction solution to cool,
Crystals precipitated by cooling on ice are collected by filtration, and further recrystallized from hexane three times. After filtration, the crystals are dried under vacuum to give 1- (N-hexylcarbamoyloxy).
-2- (3'-Thienyl) ethane was obtained. After dissolving 1.0 g of the obtained monomer in 50 ml of chloroform, 5.0 g of anhydrous ferric chloride was added under a nitrogen gas atmosphere.
Was added, and the mixture was stirred for 24 hours to perform chemical oxidation polymerization. After the reaction was completed, 500 ml of chloroform was added to the reaction solution, which was then poured into 1000 ml of deionized water, and sufficiently stirred. Thereafter, only the chloroform phase was removed using a separatory funnel, and the washing with deionized water was repeated,
When the color of the deionized water phase was eliminated by iron ions or the like, the chloroform phase was separated, chloroform was removed by a rotary evaporator, and then dried under vacuum to obtain poly {3- [2- (N-hexyl). Carbamoyloxy) ethyl] thiophene-2,5-diyl} was obtained. When the molecular weight of this polymer was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 11,000 and the weight average molecular weight (Mw) was 47000 in terms of polystyrene.

Synthesis Example (4) 6.83 g of n-octyl isocyanate and 5.13 g of 2- (3-thienyl) ethanol were mixed at 140 ° C.
Stir for hours. 50 ml of hexane is added to the reaction solution, which is further refluxed for 1 hour. After allowing the reaction solution to cool,
Crystals precipitated by cooling with ice are collected by filtration, and recrystallized three times from hexane. After filtration, the crystals are dried under vacuum to give 1- (N-octylcarbamoyloxy).
-2- (3'-Thienyl) ethane was obtained. After dissolving 1.0 g of the obtained monomer in 50 ml of chloroform, 5.0 g of anhydrous ferric chloride was added under a nitrogen gas atmosphere, and the mixture was stirred for 24 hours to perform chemical oxidation polymerization. After completion of the reaction, after adding 500 ml of chloroform to the reaction solution,
Poured into 1000 ml of deionized water and stirred well. Thereafter, only the chloroform phase was taken out using a separatory funnel, and washing with deionized water was further repeated.When the deionized water phase was no longer colored by iron ions or the like, the chloroform phase was separated and chloroform was removed using a rotary evaporator. After removal, the residue was dried under vacuum to obtain poly {3- [2- (N-octylcarbamoyloxy) ethyl] thiophene-2,5-diyl}. When the molecular weight of this polymer was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 9000 and the weight average molecular weight (Mw) was 23,000 in terms of polystyrene.

Synthesis Example (5) 9.30 g of n-dodecyl isocyanate and 5.13 g of 2- (3-thienyl) ethanol were mixed at 140 ° C.
Stir for hours. Cyclohexane 20m in this reaction solution
1 and reflux for an additional hour. Hexane 1
After adding 00 ml and refluxing for 30 minutes and allowing the reaction solution to cool,
Crystals precipitated by cooling on ice are collected by filtration, and further recrystallized three times from hexane. After filtration, the crystals are dried under vacuum to give 1- (N-dodecylcarbamoyloxy).
-2- (3'-Thienyl) ethane was obtained. After dissolving 1.0 g of the obtained monomer in 50 ml of chloroform, 5.0 g of anhydrous ferric chloride was added under a nitrogen gas atmosphere, and the mixture was stirred for 24 hours to perform chemical oxidation polymerization. After completion of the reaction, after adding 500 ml of chloroform to the reaction solution,
Poured into 1000 ml of deionized water and stirred well. Thereafter, only the chloroform phase was taken out using a separatory funnel, and washing with deionized water was further repeated.When the deionized water phase was no longer colored by iron ions or the like, the chloroform phase was separated and chloroform was removed using a rotary evaporator. After removal, the residue was dried under vacuum to obtain poly {3- [2- (N-dodecylcarbamoyloxy) ethyl] thiophen-2,5-diyl}. When the molecular weight of this polymer was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 6700 and the weight average molecular weight (Mw) was 29000 in terms of polystyrene.

Synthesis Example (6) 13.0 g of n-octadecyl isocyanate and 2- (3
-Thienyl) ethanol 5.13 g,
And stir for 2 hours. Cyclohexane 3 in this reaction solution
Add 0 ml and reflux for an additional hour. Further, 100 ml of hexane was added thereto, and the mixture was refluxed for 30 minutes, and the reaction solution was allowed to cool. Then, crystals precipitated by cooling with ice were collected by filtration, and recrystallized three times from hexane, filtered, and dried under vacuum. This gave 1- (N-octadecylcarbamoyloxy) -2- (3'-thienyl) ethane. After dissolving 1.0 g of the obtained monomer in 50 ml of chloroform, 5.0 g of anhydrous ferric chloride was added under a nitrogen gas atmosphere, and the mixture was stirred for 24 hours to perform chemical oxidation polymerization. After the reaction was completed, 500 ml of chloroform was added to the reaction solution, which was then poured into 1000 ml of deionized water, and sufficiently stirred. Thereafter, only the chloroform phase was taken out using a separatory funnel, and washing with deionized water was further repeated.When the deionized water phase was no longer colored by iron ions or the like, the chloroform phase was separated and chloroform was removed using a rotary evaporator. After removal, drying under vacuum gave poly {3- [2- (N-octadecylcarbamoyloxy) ethyl] thiophene-2,5-diyl}. When the molecular weight of this polymer was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 10 in terms of polystyrene.
000, and the weight average molecular weight (Mw) was 36,000.

Example 1 The polymer compound obtained in the above Synthesis Example (1) was spin-coated from a chloroform solution on an ITO coated glass (manufactured by Sanyo Vacuum Co., Ltd.) having a sheet resistance of about 14 Ω / □. A uniform thin film layer having a thickness of 200 nm without pinholes was formed. This was dried for 1 hour under a vacuum of 10 ^-3 torr, and then vacuum-evaporated (SGC-8 manufactured by Showa Vacuum Co., Ltd.).
Using MII), 100 nm of aluminum was vacuum-deposited on the thin film layer under a vacuum of 1 × 10 ⁻⁵ torr to produce a device. Yellow light emission was obtained by applying a DC voltage of 25 V to the device using the ITO electrode as an anode and the aluminum electrode as a cathode. The electroluminescent luminance at this time was measured using a luminance meter (LS-100 manufactured by Minolta).
Table 1 shows the results.

Example 2 In Example 1, a magnesium-silver (weight ratio: 10: 1) alloy electrode was used instead of the aluminum electrode.
A device was prepared in the same manner as in Example 1 except that vacuum deposition was performed, and by applying a DC voltage of 20 V in the same manner, yellow light emission was obtained.

Example 3 An element was manufactured in the same manner as in Example 1 except that a transparent polyethylene terephthalate film provided with a 20 nm-thick ITO by sputtering was used instead of the ITO coated glass. , DC voltage 30
By applying V in the same manner, yellow luminescence was obtained.

Example 4 In Example 1, before an aluminum electrode was formed by vacuum evaporation, an electron beam was irradiated by an electron beam irradiation apparatus (Curetron manufactured by Nissin High Voltage) at an acceleration voltage of 200 kV and an absorbed dose of 1.0 Mrad. A device was prepared in the same manner as in Example 1 except that irradiation was performed, and yellow light emission was obtained by applying a DC voltage. In addition, the electroluminescence luminance at this time was measured in the same manner. Table 1 shows the results.

Example 5 A device was prepared in the same manner as in Example 4 except that the absorbed dose of the electron beam was changed to 3.0 Mrad, and a DC voltage was applied to measure the electroluminescence luminance of the device. . Table 1 shows the results.

Example 6 A device was prepared in the same manner as in Example 4, except that the absorbed dose of the electron beam was changed to 5.0 Mrad, and a DC voltage was applied to measure the electroluminescence luminance of the device. . Table 1 shows the results.

Example 7 In Example 4, the absorbed dose of the electron beam was changed to 10.0 Mrad.
A device was prepared in the same manner as in Example 4 except that the above conditions were changed, and a DC voltage was applied to measure the electroluminescence luminance of the device. Table 1 shows the results.

[0043]

[Table 1]

Example 8 The polymer compound obtained in the above synthesis example (2) was uniformly and spin-coated on a ITO coated glass (manufactured by Geomatec) having a sheet resistance of about 10 Ω / □ from a chloroform solution by a spin coating method. A thin film layer having a thickness of 150 nm without holes was formed. This was dried for 1 hour under a vacuum of 10 ^-3 torr, and then vacuum-evaporated (SGC-8 manufactured by Showa Vacuum Co., Ltd.).
Using MII), 100 nm of aluminum was vacuum-deposited on the thin film layer under a vacuum of 1 × 10 ⁻⁵ torr to produce a device. Yellow light emission was obtained by applying a DC voltage of 25 V to the device using the ITO electrode as an anode and the aluminum electrode as a cathode. The electroluminescent luminance at this time was measured using a luminance meter (LS-100 manufactured by Minolta). Table 2 shows the results.

The emission spectrum of electroluminescence of this device was measured using a multi-channel photometer (IMUC-7000 manufactured by Otsuka Electronics Co., Ltd.). When measured at a gain of 10.0 from a measurement wavelength region of 400 nm to 700 nm, the spectrum shown in FIG. 1A was obtained.

Example 9 An element was prepared in the same manner as in Example 8, except that a magnesium-silver (weight ratio of 5: 5) alloy electrode was vacuum-deposited at 100 nm instead of the aluminum electrode, and a DC voltage was applied. As a result, yellow luminescence was obtained.

Example 10 An element was prepared in the same manner as in Example 8 except that a calcium electrode was vacuum-deposited at 100 nm instead of the aluminum electrode, and a DC voltage was applied.
A yellow luminescence was obtained.

Example 11 An element was prepared in the same manner as in Example 8, except that a transparent polyethylene terephthalate film provided with a 20 nm thick ITO by sputtering was used instead of the ITO coated glass. By applying a DC voltage, yellow luminescence was obtained.

Example 12 In Example 8, before an aluminum electrode was formed by vacuum evaporation, the electron beam was irradiated by an electron beam irradiation apparatus (Curetron manufactured by Nisshin High Voltage) at an acceleration voltage of 250 kV and an absorbed dose of 2.0 Mrad. A device was produced in the same manner as in Example 8 except that irradiation was performed, and yellow light emission was obtained by applying a DC voltage. In addition, the electroluminescence luminance at this time was measured in the same manner. Table 2 shows the results.

Example 13 A device was prepared in the same manner as in Example 8 except that the absorbed dose of the electron beam was changed to 4.0 Mrad, and a DC voltage was applied to measure the electroluminescence luminance of the device. . Table 2 shows the results.

Example 14 A device was prepared in the same manner as in Example 8, except that the absorbed dose of the electron beam was changed to 8.0 Mrad, and a DC voltage was applied to measure the electroluminescence luminance of the device. . Table 2 shows the results.

Example 15 In Example 8, the absorbed dose of the electron beam was changed to 12.0 Mrad.
A device was prepared in the same manner as in Example 8 except that the above-mentioned conditions were changed, and a DC voltage was applied to measure the electroluminescence luminance of the device. Table 2 shows the results.

[0053]

[Table 2]

Example 16 The procedure of Example 8 was repeated, except that the polymer obtained in Synthesis Example (5) was used instead of the polymer obtained in Synthesis Example (2). An element was fabricated in the same manner, and when a DC voltage was applied, orange light emission was obtained. The emission spectrum of electroluminescence was measured in the same manner as in Example 8, and the spectrum shown in FIG. 1B was obtained.

Example 17 In Example 8, the polymer compound obtained in Synthesis Example (5) was used in place of the polymer compound obtained in Synthesis Example (2).
An element was prepared in the same manner as in Example 8, except that an indium (weight ratio of 7: 3) electrode was vacuum-deposited at 100 nm, and orange light emission was obtained by applying a DC voltage of 20 V in the same manner.

Example 18 The procedure of Example 8 was repeated, except that the polymer obtained in Synthesis Example (6) was used instead of the polymer obtained in Synthesis Example (2). An element was fabricated in the same manner, and when a DC voltage was applied, orange light emission was obtained.

Example 19 In Example 8, the polymer compound obtained in Synthesis Example (6) was used in place of the polymer compound obtained in Synthesis Example (2), and a magnesium electrode was used instead of the aluminum electrode. Was prepared in the same manner as in Example 8 except that was vacuum-deposited by 150 nm, and by applying a DC voltage of 20 V in the same manner, orange light emission was obtained.

Comparative example

Synthesis Example (7) 1.0 g of 3-dodecylthiophene (manufactured by Tokyo Chemical Industry Co., Ltd.)
Was dissolved in 50 ml of chloroform, 5.0 g of anhydrous ferric chloride was added under a nitrogen gas atmosphere, and the mixture was stirred for 24 hours to perform chemical oxidation polymerization. After the reaction was completed, 500 ml of chloroform was added to the reaction solution, which was then poured into 1000 ml of deionized water, and sufficiently stirred. Thereafter, only the chloroform phase was taken out using a separatory funnel, and washing with deionized water was further repeated.When the deionized water phase was no longer colored by iron ions or the like, the chloroform phase was separated and chloroform was removed using a rotary evaporator. After the removal, the poly (3- (3-
Dodecylthiophene). When the molecular weight of this polymer was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 29000 and the weight average molecular weight (Mw) was 82 in terms of polystyrene.
000.

Comparative Example 1 The procedure of Example 8 was repeated except that the polymer obtained in Synthesis Example (7) was used instead of the polymer obtained in Synthesis Example (2). Similarly, when a device was prepared and a DC voltage was applied, only weak yellow light emission was obtained. When the emission spectrum of this electroluminescence was measured in the same manner as in Example 8, FIG.
Was obtained.

[0061]

The polymer compound obtained by polymerizing the compound represented by the general formula (I) used in the present invention is easily soluble in many organic solvents and forms a thin film without pinholes. By using this polymer compound,
An organic electroluminescence element capable of easily increasing the area can be manufactured, and excellent emission characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 shows emission spectra of electroluminescence in Examples and Comparative Examples of the present invention.

Claims (4)

[Claims] 1. A thin film layer containing a polymer compound obtained by polymerizing a compound represented by the following general formula (I) between opposed electrodes at least one of which is transparent or translucent. Characteristic organic electroluminescent element. Embedded image (In the formula (I), L represents a divalent linking group, and R represents a hydrogen atom, an alkyl group, an aryl group, a cyclic ester group, a non-cyclic ester group, a cyclic ether group, or a non-cyclic ether group. Represents a heterocyclic ring. N is 1 or 2, and when n is 2, Rs may be the same or different.) 2. The organic electroluminescence device according to claim 1, wherein the thin film layer is irradiated with an electron beam. 3. The organic electroluminescent device according to claim 1, wherein the heterocyclic ring of A serving as a skeleton of the compound represented by the general formula (I) is thiophene, furan, or pyrrole. 4. The compound represented by the general formula (I) is 1-
3. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device is (N-alkylcarbamoyloxy) -2- (3'-thienyl) ethane.