JP3459687B2 - EL device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent device having a light emitting layer made of a light emitting substance and capable of directly converting the applied electric field energy into light energy by applying an electric field.

More specifically, unlike conventional incandescent lamps, fluorescent lamps, light emitting diodes, etc., it has the characteristics of large area, high resolution, thinness, light weight, high speed operation, and complete solid state device.
The present invention relates to an electroluminescent element used for an electroluminescence (EL) panel which may meet high requirements.

[0003]

2. Description of the Related Art The electroluminescence phenomenon of organic materials is 1963 P.
observed with an anthracene single crystal by J. Ope et al.
Chem. Phys. 38 (1963) 2042), followed by 1965 Helfinch and Schneid.
er has succeeded in observing a relatively strong injection type EL by using a solution electrode system with high injection efficiency (Phys.
ev. Lett. 14 (1965) 229).

Since then, US Pat. No. 3,172,862,
US Patent 3,173,050, US Patent 3,710,1
67, J. Chem. Phys. 44 (1966) 29
02, J. Chem. Phys. 50 (1969) 14
364, J.I. Chem. Phys. 58 (1973) 1
542, or Chem. Phys. Lett. 36
As reported in (1975) 345 and the like, studies have been conducted on forming an organic light-emitting substance from a conjugated organic host substance and a conjugated organic activator having a condensed benzene ring. Naphthalene, anthracene, phenanthrene, tetracene,
Pyrene, benzopyrene, chrysene, picene, carbazole, fluorene, biphenyl, terphenyl, triphenylene oxide, dihalobiphenyl, trans-stilbene, 1,4-diphenylbutadiene, etc. are shown as examples of organic host substances, and anthracene, tetracene,
And pentacene were mentioned as examples of activators. However, all of these organic light-emitting substances existed as a single layer having a thickness of more than 1 μm, and a high electric field was required for light emission. For this reason, research on thin-film devices by the vacuum deposition method has been advanced (for example, Thin Solid Film).
s 94 (1982) 171, Polymer 24
(1983) 748, Jpn. J. Appl. Phy
s. 25 (1986) L773). However, although thinning was effective in reducing the driving voltage, it was not possible to obtain a practically high-luminance device.

However, in recent years, Tangs et al. (App
l. Phys. Lett. 51 (1987) 913 or US Pat. No. 4,356,429) devised an EL device in which two extremely thin layers (a charge transport layer and a light emitting layer) were laminated by vacuum vapor deposition between an anode and a cathode, and at a low driving voltage. Realized high brightness. This type of stacked organic EL device has been actively researched since then, and is disclosed in, for example, JP-A-59-194393, US Pat. No. 4,539,507, and JP-A-59-19439.
3, U.S. Pat. No. 4,720,432, JP-A-63-264
692, Appl. Phys. Lett. 55 (198
9) 1467, JP-A-3-163188 and the like.

Furthermore, Jpn. J. Appl. Phy
s. 27 (1988) L269 and L713, an EL device having a three-layer structure in which the functions of carrier transport and light emission are separated has been reported, and restrictions on carrier transport performance are alleviated when selecting a dye for the light emitting layer that determines the emission color. It also suggests that the degree of freedom in selection increases considerably, and that holes and electrons (or excitons) can be effectively confined in the central light emitting layer to improve light emission.

A vacuum evaporation method is generally used to form a laminated organic EL element, but it has been reported that an element having a considerable brightness can be obtained also by the casting method (for example, 50th Society of Applied Physics, Japan). Academic Conference Lecture Proceedings 10
06 (1989) and Proceedings of the 50th Academic Meeting of the Society of Biological Society of Japan 1041 (1990)).

Furthermore, even a mixed one-layer type EL device formed by a dip coating method from a solution in which polyvinylcarbazole as a hole transport compound, oxadiazole derivative as an electron transport compound and coumarin 6 as a light emitter are mixed, has a considerably high luminous efficiency. It is reported that you can get it (for example,
Proceedings 1086 (19)
91)).

As mentioned above, recent advances in organic EL devices suggest a remarkably wide range of potential applications.

[0010]

However, the history of these studies is still shallow, and the studies for materials and devices have not been sufficiently conducted. At present, there is still a problem in terms of durability such as light output with higher brightness, deterioration with time due to long-term use, and deterioration due to atmospheric gas containing oxygen or moisture. Further, in consideration of application to a full-color display or the like, problems such as diversification of emission wavelengths for precisely selecting emission hues of blue, green and red have not yet been sufficiently solved.

An object of the present invention is, firstly, to provide an electroluminescence device having an extremely high brightness light output.

Secondly, it is intended to provide an electroluminescent device having various emission wavelengths, exhibiting various emission hues, and having extremely high heat resistance and durability.

Thirdly, it is to provide an electroluminescent device material which is easy to manufacture and can be provided at a relatively low cost.

[0014]

The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, are composed of an anode and a cathode and one or more layers of organic compounds sandwiched between them. In the electroluminescent device, it has been found that at least one of the organic compound layers contains a polycarbonate polymer having a charge-transporting group in at least a side chain, which is extremely suitable. I arrived.

Hereinafter, this polycarbonate polymer is referred to as a charge-transporting polycarbonate polymer.

By using a charge-transporting group as a side chain,
The charge transport capacity is improved. As the charge transporting group,
Der which nitrogen and the benzene ring having the structure bound
Ri is a group having a group having a preparative triphenylamine structure, a group or a biphenyl diamine structure having a hydrazone structure.

[0017] As radicals having triphenylamine structures are those represented by the following following general formula (C).

[0018]

[Outside 10] (In the general formula (C), any one of R _{21 to} R ₂₆ becomes a divalent group and is bonded to carbon in the main chain of the polycarbonate polymer via — (CH ₂ ) _c —. Represents an integer of 5. R _{21 to} R ₂₆ are hydrogen, halogen, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, and a substituent. An alkoxy group which may have a group, an arylamino group which may have a substituent, an aryl ether group which may have a substituent or an amino aryl ether which may have a substituent, or R ₂₁ and the R ₂₂ is, or as a substituent of the R ₂₃ and R ₂₄ are, or binds to R ₂₅ and the R ₂₆ are bonded to may form a carbocyclic or heterocyclic ring .R ₂₁ to R ₂₆ is for example an amino group, a halogen or the like.) as R ₂₁ to R _26, in particular coal C1-4 alkyl group or an alkoxy group, or a chlorine or bromine are preferred.

Preferred compounds of general formula (C) are shown below.

[0020]

[Outside 11]

[0021]

[Outside 12]

[0022]

[Outside 13]

[0023]

[Outside 14]

[0024]

[Outside 15]

[0025]

[Outside 16]

[0026] As group having a hydrazone structure are those represented by the following following general formula (D).

[0027]

[Outside 17] (In the general formula (D), any one of R _{27 to} R ₃₀ becomes a divalent group and is bonded to carbon of the main chain of the polycarbonate polymer via — (CH ₂ ) _d —. Represents an integer of 5. R ₂₇ and R ₂₈ are hydrogen, halogen, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, and a substituent. An alkoxy group which may have a group, an alkylidene group which may have a substituent, or a monovalent group containing a condensed polycyclic hydrocarbon,
R ₂₉ and R ₃₀ are an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, It represents an alkylidene group which may have a substituent or a monovalent group containing a condensed polycyclic hydrocarbon, and at least one of R ₂₉ and R ₃₀ is an aryl group. The substituent bonded to R _{27 to} R ₃₀ is preferably, for example, an amino group or halogen. As R ₂₇ and R ₂₈ , an alkyl group or an alkoxy group having 1 to 4 carbon atoms, chlorine or bromine is particularly preferable. As R ₂₉ and R ₃₀ , an alkyl group or an alkoxy group having 1 to 4 carbon atoms is particularly preferable.

Preferred compounds of the general formula (D) are shown below.

[0029]

[Outside 18]

[0030]

[Outside 19]

[0031]

[Outside 20]

[0032] group having a biphenyl diamine structure are those represented by the following following general formula (E).

[0033]

[Outside 21] (In the general formula (E), R₃₁~ R₃₄One of them is a divalent group
And then- (CH₂)_e-Through polycarbonate weight
It bonds to the carbon in the main chain of the coalescence. e represents an integer of 0 to 5
You R₃₁And R₃₃Is an alkyl group which may have a substituent,
Having an alkenyl group or a substituent which may have a substituent
R is a good alkoxy group₃₂And R ₃₄Is a substituent
Alkyl groups that may have and alkyl groups that may have substituents
Nyl group, aryl group which may have a substituent or substituent
Represents an alkoxy group which may have. R₃₁~ R₃₄Combined with
As the substituent to be added, for example, an amino group, halogen and the like are preferable.
Good ) R₃₁~ R₃₄As an alkyl group of 1 to 4 or
Alkoxy groups are preferred.

Preferred compounds of the general formula (E) are shown below.

[0035]

[Outside 22]

[0036]

[Outside 23]

[0037] as a charge transporting polycarbonate polymer used in the present invention are those having a repeating unit represented by the following following general formula (A).

[0038]

[Outside 24] (In the general formula (A), R _{1 to} R ₈ are hydrogen, halogen, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, and an aryl group which may have a substituent. Or, it represents an alkoxy group which may have a substituent R ₉ and R _10.
Is a group containing one selected from the general formulas (C), (D) and (E), and the other is hydrogen, an alkyl group which may have a substituent, or a substituent. Is an alkenyl group or an aryl group which may have a substituent, or R ₉ and R ₁₀ are both the above general formulas (C) and (D).
And a group including a group selected from (E). Further, the charge-transporting polycarbonate polymer used in the present invention is preferably one having a repeating unit represented by the general formula (A) and a repeating unit represented by the following general formula (B).

[0039]

[Outside 25] (In the general formula (B), R _{11 to} R ₁₈ represent hydrogen, halogen, an alkyl group which may have a substituent or an aryl group which may have a substituent. X represents

[0040]

[Outside 26] R ₁₉ and R ₂₀ are hydrogen,
It represents halogen, an alkyl group which may have a substituent or an aryl group which may have a substituent, or R ₁₉ and R ₂₀ may be bonded to each other to form a carbocycle or a heterocycle. a shows the integer of 0-2000, b shows the integer of 0-20. The substituent bonded to R _{11 to} R ₂₀ is preferably, for example, an amino group or halogen. ) The repeating unit of the general formula (A) and the general formula (B)
The composition ratio with the repeating unit of is 0 <(A) /
((A) + (B)) ≦ 1, more preferably 0.1 ≦ (A) /
((A) + (B)) ≦ 1 is preferable.

Specific examples of the divalent phenol type polycarbonate unit compound represented by the general formula (B) include bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) ether and bis (4-hydroxyphenyl). ) Sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ketone, 1,1
-Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A; BPA), 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4- Hydroxyphenyl)
Cyclohexane (bisphenol Z; BPZ), 2,2
-Bis (4-hydroxy-3,5-dibromophenyl)
Propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3-chlorophenyl) )propane,
2,2-bis (4-hydroxy-3-methylphenyl)
Propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, α, ω -Bis [3
-(0-Hydroxyphenyl) propyl] polydimethylsiloxane and the like are preferable.

The molecular weight of the charge-transporting polycarbonate polymer used in the electroluminescent device of the present invention is preferably 1,000 to 1,000,000, more preferably 2,000 to 700,000 on a weight average basis. In the present invention, the molecular weight is a value measured by the GPC method.

Next, synthesis examples of the charge transporting polycarbonate polymer used in the present invention will be shown.

Synthesis Example 1 580 m of 8.8% (w / v) aqueous sodium hydroxide solution
188.4 g of a dihydric phenol having the triphenylamine structure of the following structural formula (1) and 0.1 g of hydrosulfite were added to 1 and dissolved. To this, 360 ml of methylene chloride was added, and while stirring at 15 ° C,
2.0 g of pt-butylphenol (PTBP) was added, and then 51 g of phosgene was blown in over 60 minutes.

[0045]

[Outside 27]

After the completion of blowing, the reaction solution was emulsified by vigorous stirring, 0.2 ml of triethylamine was added after emulsification, and the mixture was stirred for about 1 hour for polymerization.

The polymerization solution was separated into an aqueous phase and an organic phase, the organic phase was neutralized with phosphoric acid, and the washing was repeated until the pH of the washing solution became neutral. Then, 470 ml of isopropanol was added to precipitate the polymer. Let The precipitate was filtered and then dried to obtain a powder polymer.

This polymer had an intrinsic viscosity [η] of 0.46 dl / g at a temperature of 20 ° C. in a solution of methylene chloride in a concentration of 0.5 g / dl.

The above-obtained polymer thus obtained was analyzed by infrared absorption spectroscopy.
As a result of analyzing from 1650 cm ^-1Carboni in the position
Absorption by ru radical, 1240cm^-1Ether bond at position
Must be absorbed by and has a carbonate bond
Was confirmed. Moreover, 3650-3200 cm^-1Position of
Almost no absorption due to hydroxyl groups was observed.

Therefore, this polymer was recognized as a polycarbonate polymer composed of the following repeating units.

[0051]

[Outside 28]

Synthesis Example 2 Except that 199.6 g of the dihydric phenol of the following structural formula (2) was used in place of the dihydric phenol of the structural formula (1),
The same procedure as in Synthesis Example 1 was performed.

[0053]

[Outside 29] The obtained polymer had an intrinsic viscosity [η] of 0.46 dl / g.
Then, the infrared absorption spectrum analysis confirmed that this polymer was a polycarbonate polymer having the following repeating units.

[0054]

[Outside 30]

Synthesis Example 3 The same procedure as in Synthesis Example 1 was carried out except that 194 g of the following divalent phenol represented by the structural formula (3) was used instead of the divalent phenol represented by the structural formula (1).

[0056]

[Outside 31] The obtained polymer had an intrinsic viscosity [η] of 0.46 dl / g.
Then, the infrared absorption spectrum analysis confirmed that this polymer was a polycarbonate polymer having the following repeating units.

[0057]

[Outside 32]

Synthesis Example 4 Except that 205.2 g of the dihydric phenol of the following structural formula (4) was used in place of the dihydric phenol of the structural formula (1),
The same procedure as in Synthesis Example 1 was performed.

[0059]

[Outside 33] The obtained polymer had an intrinsic viscosity [η] of 0.46 dl / g.
Then, the infrared absorption spectrum analysis confirmed that this polymer was a polycarbonate polymer having the following repeating units.

[0060]

[Outside 34]

Synthesis Example 5 Synthesis Example 1 was repeated except that 308 g of the following divalent phenol represented by the structural formula (5) was used in place of the divalent phenol represented by the structural formula (1).

[0062]

[Outside 35] The obtained polymer had an intrinsic viscosity [η] of 0.48 dl / g.
Then, the infrared absorption spectrum analysis confirmed that this polymer was a polycarbonate polymer having the following repeating units.

[0063]

[Outside 36]

Synthesis Example 6 Instead of the dihydric phenol of structural formula (1), 99.8 g of dihydric phenol of structural formula (2) and bisphenol A were used.
The same procedure as in Synthesis Example 1 was performed except that 45.6 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0066]

[Outside 37]

Synthesis Example 7 Instead of the dihydric phenol of the structural formula (1), 20.0 g of the dihydric phenol of the structural formula (2) and bisphenol A were used.
The same procedure as in Synthesis Example 1 was performed except that 82.1 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0069]

[Outside 38]

Synthesis Example 8 Instead of the dihydric phenol of the structural formula (1), 59.9 g of the dihydric phenol of the structural formula (2) and bisphenol A were used.
The same procedure as in Synthesis Example 1 was performed except that 63.8 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0072]

[Outside 39]

Synthesis Example 9 The same procedure as in Synthesis Example 1 was carried out except that 188 g of the following divalent phenol represented by the structural formula (6) was used in place of the divalent phenol represented by the structural formula (1).

[0074]

[Outside 40] This polymer has a concentration of 0.5 g using methylene chloride as a solvent.
The intrinsic viscosity [η] of the solution of / dl at a temperature of 20 ° C was 0.46 dl / g.

The above-obtained polymer thus obtained was analyzed by infrared absorption spectroscopy.
As a result of analyzing from 1650 cm ^-1Carboni in the position
Absorption by ru radical, 1240cm^-1Ether bond at position
Must be absorbed by and has a carbonate bond
Was confirmed. Moreover, 3650-3200 cm^-1Position of
Almost no absorption due to hydroxyl groups was observed.

Therefore, this polymer was recognized as a polycarbonate polymer composed of the following repeating units.

[0077]

[Outside 41]

Synthesis Example 10 Except that 236.4 g of the dihydric phenol of the following structural formula (7) was used in place of the dihydric phenol of the structural formula (1),
The same procedure as in Synthesis Example 1 was performed.

[0079]

[Outside 42] The obtained polymer had an intrinsic viscosity [η] of 0.47 dl / g.
Then, the infrared absorption spectrum analysis confirmed that this polymer was a polycarbonate polymer having the following repeating units.

[0080]

[Outside 43]

Synthesis Example 11 Instead of the dihydric phenol of structural formula (1), 94 g of dihydric phenol of structural formula (6) and bisphenol A4 were used.
The same procedure as in Synthesis Example 1 was performed except that 5.6 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0083]

[Outside 44]

Synthesis Example 12 Instead of the dihydric phenol of structural formula (1), 18.8 g of dihydric phenol of structural formula (6) and bisphenol A were used.
The same procedure as in Synthesis Example 1 was performed except that 82.1 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0086]

[Outside 45]

Synthesis Example 13 Instead of the dihydric phenol of the structural formula (1), 56.4 g of the dihydric phenol of the structural formula (6) and bisphenol A were used.
The same procedure as in Synthesis Example 1 was performed except that 63.8 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0089]

[Outside 46]

Synthesis Example 14 Except that 197.6 g of the dihydric phenol having the following structural formula (8) was used in place of the dihydric phenol having the structural formula (1),
The same procedure as in Synthesis Example 1 was performed.

[0091]

[Outside 47] This polymer has a concentration of 0.5 g using methylene chloride as a solvent.
The intrinsic viscosity [η] of the solution of / dl at a temperature of 20 ° C was 0.47 dl / g.

The above-obtained polymer thus obtained was analyzed by infrared absorption spectroscopy.
As a result of analyzing from 1650 cm ^-1Carboni in the position
Absorption by ru radical, 1240cm^-1Ether bond at position
Must be absorbed by and has a carbonate bond
Was confirmed. Moreover, 3650-3200 cm^-1Position of
Almost no absorption due to hydroxyl groups was observed.

Therefore, this polymer was recognized as a polycarbonate polymer composed of the following repeating units.

[0094]

[Outside 48]

Synthesis Example 15 Synthesis Example 15 was repeated except that 236 g of the dihydric phenol represented by the following structural formula (2) was used instead of the dihydric phenol represented by the structural formula (1).

[0096]

[Outside 49] The obtained polymer had an intrinsic viscosity [η] of 0.47 dl / g.
Then, the infrared absorption spectrum analysis confirmed that this polymer was a polycarbonate polymer having the following repeating units.

[0097]

[Outside 50]

Synthesis Example 16 Instead of the dihydric phenol of structural formula (1), 98.8 g of dihydric phenol of structural formula (8) and bisphenol A were used.
The same procedure as in Synthesis Example 1 was performed except that 45.6 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0100]

[Outside 51]

Synthesis Example 17 Instead of the dihydric phenol of the structural formula (1), 23.6 g of the dihydric phenol of the structural formula (9) and bisphenol A were used.
The same procedure as in Synthesis Example 1 was performed except that 82.1 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0103]

[Outside 52]

Synthesis Example 18 70.8 g of dihydric phenol of structural formula (9) and bisphenol A were used instead of dihydric phenol of structural formula (1).
The same procedure as in Synthesis Example 1 was performed except that 63.8 g was used.

The intrinsic viscosity [η] of the obtained polymer was 0.4.
At 6 dl / g, this polymer was confirmed to be a polycarbonate polymer having the following repeating unit by infrared absorption spectrum analysis.

[0106]

[Outside 53] In the light emitting device of the present invention, the compound composed of the above-mentioned charge transporting polycarbonate polymer is formed between the anode and the cathode by a solution coating method, a hot pressing method or the like. The thickness of the organic layer is less than 2 μm, preferably less than 0.5 μm, and it is preferable to make the film thinner.

The present invention will be described in more detail below with reference to the drawings.

FIG. 1 shows a structure in which an anode, a light emitting layer and a cathode are sequentially provided on a substrate. The light emitting device used here is useful when it has a single hole transporting ability, an electron transporting ability and a light emitting ability by itself, or when a compound having each characteristic is mixed and used.

FIG. 2 shows a structure in which an anode, a hole transport layer, an electron transport layer and a cathode are sequentially provided on a substrate. In this case, the light-emitting substance uses a material having a hole-transporting property, an electron-transporting property, or both in each layer, and is used in combination with a simple hole-transporting substance or electron-transporting substance having no light-emitting property. Useful in cases.

FIG. 3 shows a structure in which an anode, a hole transport layer, a light emitting layer, an electron transport layer and a cathode are sequentially provided on a substrate. This separates the functions of carrier transport and light emission, and is used in combination with a compound having hole transporting property, electron transporting property, and light emitting property in a timely manner to greatly increase the degree of freedom of material selection and to increase the light emission. Since various compounds having different wavelengths can be used, the emission hue can be diversified. Further, it becomes possible to effectively confine holes and electrons (or excitons) in the central light emitting layer to improve the light emitting efficiency.

The compounds of the present invention are compounds having extremely high charge transporting ability as compared with conventional compounds, and can be used in any of the forms shown in FIGS. 1, 2 and 3 as required. .

Further, the compounds of the present invention are shown in FIG. 1, FIG. 2 and FIG.
In any of the above cases, two or more kinds of the above compounds may be used if necessary.

In the present invention, at least one of the organic compound layers constituting the electroluminescent element is a compound comprising the above-mentioned charge-transporting polycarbonate polymer. If necessary, an electrophotographic photoreceptor is used. Hole-transporting compounds that have been studied in fields and hole-transporting luminescent compounds that have been known so far (for example, compounds shown in Table 1)
Alternatively, two or more kinds of electron-transporting compounds and known electron-transporting luminescent compounds (for example, compounds listed in Table 2) can be used.

[0114]

[Outside 54]

[0115]

[Outside 55]

An electroluminescent device using the compound of the present invention is
Generally, the polymer is used alone or in combination with a suitable binder resin to form a thin film.

The binder can be selected from a wide range of binder resins, for example, polyvinyl carbazole resin, polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin. , Methacrylic resin, phenolic resin, epoxy resin,
Examples thereof include silicone resin, polysulfone resin, and urea resin, but are not limited thereto. You may use these individually or in mixture of 2 or more types as a homopolymer or a copolymer polymer.

As the anode material, a material having a work function as large as possible is preferable, and examples thereof include nickel, gold, platinum, palladium, selenium, rhenium, iridium and alloys thereof, tin oxide, indium tin oxide (ITO), and copper iodide. Is preferred. Further, a conductive polymer such as poly (3-methylthiophene), polyphenylene sulfide or polypyrrole can also be used.

On the other hand, as the cathode material, silver, lead, tin, magnesium, aluminum, calcium, manganese, indium, chromium or an alloy thereof having a small work function is used.

At least one of the materials used for the anode and the cathode is 50 in the emission wavelength region of the device.
%, It is preferable to transmit more light.

The electroluminescent element of the present invention is a conventional incandescent lamp,
Unlike fluorescent lamps or light emitting diodes, large area,
It is a high resolution, thin, light weight, high speed operation, complete solid-state device, and is used for electroluminescence (EL) panels which may meet high requirements.

As the transparent substrate used in the present invention, glass, plastic film or the like is used.

Hereinafter, the present invention will be specifically described with reference to examples.

[0124]

【Example】

(Example 1) Indium tin oxide (ITO) film (50n)
m) A 120 nm light emitting layer made of the polycarbonate polymer (weight average molecular weight 25000) of Synthesis Example 1 was provided on the transparent anode of glass by a casting method, and 170 nm of the cathode made of Mg / Ag (10/1) alloy was vacuumed. It was formed by vapor deposition to prepare a device as shown in FIG.

When the anode and the cathode of the element thus prepared were connected with a lead wire and a DC power source was connected and a voltage of 10 V was applied, a current density of 10.8 mA / cm ² was passed through the element and 0.20 mW A light output of / cm ² was confirmed.

Then, the current density as it is (10.8 m
A / cm ² ) was maintained for 90 hours, and after 90 hours, an optical output with a final output of 0.17 mW / cm ² was obtained with an applied voltage of 12V.

(Examples 2 to 5) Instead of the polycarbonate polymer of Synthesis Example 1 used in Example 1 above, Synthesis Example 2 (Example 2), Synthesis Example 3 (Example 3), and Synthesis Example 4 ( An element was prepared in the same manner as in Example 1 except that Example 4) and Synthesis Example 17 (Example 5) were used.

Then, a current having a current density of 11.0 mA / cm ^{2 was} passed through the obtained devices for 100 hours. The results at that time are shown in Table 3 below.

[0129]

Comparative Examples 1 and 2 Example 2 was repeated except that the compound of the following structural formula and a polycarbonate A resin (weight average molecular weight 25000) were used in place of the polycarbonate polymer of Synthesis Example 1 used in Example 1 above. An element was formed in the same manner as in.

[0131]

[Outside 56]

Then, a current having a current density of 11.0 mA / cm ² was passed through the obtained devices for 100 hours in the same manner as in Examples 2-5. The results at that time are shown in Table 4 below.

[0133]

As is clear from Tables 3 and 4, it is understood that the device using the compound of the present invention is extremely excellent in light output and durability as compared with the device using the comparative compound.

[0135]

The electroluminescent device using the compound of the present invention can obtain light emission of extremely high brightness at a low applied voltage and is extremely excellent in durability.

Further, the element can be prepared by the casting method or the like, and it is possible to easily prepare the element having a large area at a relatively low cost.

[Brief description of drawings]

FIG. 1 is a typical cross-sectional view of an electroluminescent device according to the present invention.

FIG. 2 is a typical cross-sectional view of an electroluminescent device according to the present invention.

FIG. 3 is a typical sectional view of an electroluminescent device according to the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etsukazu Sakakibara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kiyoshi Sakai 3-30-2 Shimomaruko, Ota-ku, Tokyo Ki Within the Canon Inc. (72) Inventor Noriyoshi Ogawa 2-12 Shinshu-cho, Toyonaka City, Osaka Prefecture Mitsubishi Gas Chemicals Co., Ltd. Inside the Osaka Plant (56) Reference JP-A-5-310904 (JP, A) JP-A-4 -320420 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05B 33/14 H05B 33/22 C09K 11/06 G03G 5/07

Claims (5)

(57) [Claims] 1. An anode and a cathode, and a device sandwiched between them.
Electric field emission composed of one or more layers of organic compounds
In the optical element, At least one of the organic compound layers has a charge transport property.
Polymer having a group of at least in the side chain
ContainsThen The polycarbonate polymer is represented by the following general formula (A):
Has a repeating unit Electric field generation characterized by
Optical element.[Outer 1] (In the general formula (A), R ₁ ~ R ₈ Is hydrogen, halogen, substituent
An alkyl group which may have a substituent or an alkyl group which may have a substituent
Kenyl group, optionally substituted aryl group or substituent
The alkoxy group which may have a group is shown. R ₉ And R
_Ten One of the following general formulas (C), (D) and (E)
Shows charge-transporting groups, including selected ones, the other being water.
Element, optionally substituted alkyl group, having a substituent
Good alkenyl group or aryl which may have a substituent
Represents a radical or R ₉ And R _Ten Both are the following general
A battery containing one selected from formulas (C), (D) and (E)
It shows the group of cargo transportability. ) [Outside 2] (In the general formula (C), R _{twenty one} ~ R ₂₆ One of them is a divalent group
And then- (CH ₂ ) _c R in the general formula (A) in combination with-
₉ Or R _Ten Becomes c shows the integer of 0-5. R _{twenty one} ~
R ₂₆ Is hydrogen, halogen, or an alkyl which may have a substituent.
Group, optionally substituted alkenyl group, substituted
May have an aryl group or a substituent Good alkoxy
Group, an arylamino group which may have a substituent, a substituent
Optionally having an aryl ether group or a substituent
Also represents a good aminoaryl ether group. Or R _{twenty one} When
R _{twenty two} Or, or R _{twenty three} And R _{twenty four} Or, or R _{twenty five} And R
₂₆ And may combine to form a carbocycle or heterocycle.
Yes. ) [Outside 3] (In the general formula (D), R ₂₇ ~ R ₃₀ One of them is a divalent group
And then- (CH ₂ ) _d R in the general formula (A) in combination with-
₉ Or R _Ten Becomes d shows the integer of 0-5. R ₂₇ Over
And R ₂₈ Is hydrogen, halogen, or an alkyl which may have a substituent.
Group, an alkenyl group which may have a substituent, a substituent
Optionally aryl group, optionally substituted alkyl group
Si group, an alkylidene group which may have a substituent, or a condensed group
A monovalent group containing a polycyclic hydrocarbon, R ₂₉ And R ₃₀ Is
Alkyl group which may have a substituent, which may have a substituent
Alkenyl group, aryl group which may have a substituent,
Alkoxy group, which may have a substituent, or substituent, which may have a substituent
Alkylidene group or condensed polycyclic hydrocarbon containing one
Indicates a valent group, R ₂₉ And R ₃₀ At least one of them is an ant
Group. ) [Outside 4] (In the general formula (E), R ₃₁ ~ R ₃₄ One of them is a divalent group
And then- (CH ₂ ) _e R in the general formula (A) in combination with-
₉ Or R _Ten Becomes e shows the integer of 0-5. R ₃₁ Over
And R ₃₃ Is an alkyl group which may have a substituent or has a substituent.
Alkenyl groups or substituents
Rucoxy group, R ₃₂ And R ₃₄ May have a substituent
Alkyl group, alkenyl group which may have a substituent,
May have a substituent, may have an aryl group or a substituent
It shows a good alkoxy group. ) 2. The polycarbonate polymer has a repeating unit represented by the general formula (A) and a repeating unit represented by the following general formula (B), and the repeating unit of the general formula (A): The electroluminescent device according to claim 1, wherein the composition with the repeating unit of the following general formula (B) is 0 <(A) / ((A) + (B)) ≦ 1 in molar ratio. [Outside 5] (In the general formula (B), R _{11 to} R ₁₈ represent hydrogen, halogen, an alkyl group which may have a substituent or an aryl group which may have a substituent. X represents [external formula 6] R ₁₉ and R ₂₀ are hydrogen,
It represents a halogen, an alkyl group which may have a substituent or an aryl group which may have a substituent, or R ₁₉ and R ₂₀ may combine with each other to form a carbocycle or a heterocycle. a shows the integer of 0-200, b shows the integer of 0-20. ) 3. The electroluminescent device according to claim 2, wherein the composition ratio is 0.1 ≦ (A) / ((A) + (B)) ≦ 1. 4. The electroluminescent device according to claim 1, wherein the weight average molecular weight of the polycarbonate polymer is 1,000 to 1,000,000. 5. The electroluminescent device according to claim 4, wherein the molecular weight is 2000 to 700,000.