JP2003313240A - Vinyl polymer and organic electroluminescent element made by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the heat resistance of an organic electroluminescent element. <P>SOLUTION: At least one organic layer (particularly hole transfer layer) between a pair of electrodes of an organic electroluminescent (EL) element is formed from a polymer of a vinyl compound represented by formula (1) (wherein R<SP>1</SP>and R<SP>2</SP>may be the same or different and are each H, a halogen atom, an alkyl group, or an alkoxy group). The polymer has a glass transition temperature of about 200-250°C and high heat resistance. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vinyl polymer useful for forming an organic electroluminescence device having excellent heat resistance, a vinyl compound useful as a raw material for the vinyl polymer, and an organic electroluminescence device using the vinyl polymer. Regarding the device.

[0002]

2. Description of the Related Art An organic electroluminescence element (hereinafter sometimes referred to as "organic EL element") is used in a display device. This organic EL element requires heat resistance in addition to properties such as high brightness, high light emission, full-color display property, durability, and a large amount of heat generated during driving. In particular, when the organic EL element is used for indoor lighting, it is expected that a large amount of Joule heat will be generated. In addition, in in-vehicle display applications, heat resistance is an important factor because the surrounding environment may become hot. As described above, as the use of the organic EL element is expanded, it is practically important to improve the heat resistance of the organic EL element.

The organic thin film used for the organic EL element is usually
It is in an amorphous glass state from the viewpoint of moldability.
Further, in order to manufacture an element having high heat resistance, it is necessary to use an organic material having a high glass transition temperature for forming a thin film.

Regarding the materials for organic EL devices, several kinds of materials forming amorphous glass have been reported so far. However, the glass transition temperature (T
Most of g) are low at or below 150 ° C and around 150 ° C. For example, as a hole transport material, Tg is 75 to 1
Compounds represented by the following formulas (2a) to (2f) at 51 ° C. have been proposed, and as an electron transport material, Tg is 107 to 136.
Compounds represented by the following formulas (3a) to (3c) at ℃ have been proposed. Further, as a light emitting material, Tg is 84 to 13
Examples thereof include compounds represented by the following formulas (4a) to (4c) at 2 ° C. Compounds (2a) to (2f), (3a) to (3c), and (4
a) to (4c) are compounds found by the present inventors.

[0005]

[Chemical 3]

[0006]

[Chemical 4]

[0007]

[Chemical 5]

With such a material, it is difficult to improve the heat resistance of the organic EL element because of its low glass transition temperature. Further, these materials also have insufficient moldability.

As a polymer organic EL device material, π
A main chain type polymer having an electronic system as a main chain and a side chain type polymer having a side chain are known. These materials are excellent in moldability. Examples of the main chain type polymer include materials represented by the following formula.

[0010]

[Chemical 6]

On the other hand, the side chain type polymer has a variety of choices of the π electron system chromophore which is the side chain and is also excellent in chemical stability. Furthermore, the main chain has a non-conjugated structure. Since it is also easy, molding processability can be easily imparted. It also has the advantage that it has excellent photoconductivity and that the standard oxidation-reduction potential is constant regardless of the doping rate.
The present inventors have previously reported, as such a side chain type polymer, a polymer having carbazole, ferrocene, triphenylamine, pyrene, perylene, oligothiophenes and the like as a π electron side chain group. It has been clarified that these polymers can be applied to positive electrode materials for secondary batteries, p-type semiconductor materials for photoelectric conversion elements, electrochromic materials, and the like (Synth.Met., 41-43,303).
1 (1991) and references cited therein, such as M
acromolecules, 28,723 (1995), Synth.Met., 81,157 (199
6), Maclomolecules, 30,380 (1997), Synth.Met., 103,969
(1999), and Electrochim. Acta, 45, 1543 (2000)). However, even with the polymeric materials described in these documents,
The glass transition temperature is low and it is difficult to improve heat resistance.

Thus, in order to improve the heat resistance and molding processability of the organic EL device, a polymer material having a high glass transition temperature is required.

[0013]

Therefore, an object of the present invention is to provide a vinyl polymer having excellent heat resistance and moldability and useful as a material for an organic EL device, and a vinyl compound useful for obtaining this vinyl polymer. To do.

Another object of the present invention is to provide an organic EL device having excellent heat resistance.

[0015]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned objects, the present inventors have found that a vinyl polymer obtained from a novel vinyl compound having a tris (biphenylyl) amine skeleton as a π-electron side chain group is obtained. They have found that they are useful as hole transport materials for organic EL devices and have high heat resistance, and completed the present invention.

That is, the vinyl compound of the present invention is represented by the following formula (1).

[0017]

[Chemical 7]

(Where R is¹And R²Are the same or different,
Hydrogen atom, halogen atom, alkyl group or alkoxy group
Indicates) In the above formula, R¹And R²Is a hydrogen atom, halogen atom
Child, straight chain or branched chain C _1-6Alkyl group or C_1-6Arco
It may be a xy group or the like.

The vinyl polymer of the present invention has a unit represented by the following formula (2).

[0020]

[Chemical 8]

(Wherein R ¹ and R ² are the same or different,
A hydrogen atom, a halogen atom, an alkyl group or an alkoxy group is shown.) The glass transition temperature of the vinyl polymer is 200 to 25.
It may be about 0 ° C.

The present invention also includes an organic electroluminescence device having at least one organic layer containing the vinyl polymer between a pair of electrodes. The organic layer is
You may comprise from the hole transport layer containing the said vinyl polymer.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION [Vinyl Compound] The vinyl compound (vinyl monomer) represented by the above formula (1) is a novel compound. In the formula (1), the halogen atom represented by R ¹ and R ² includes fluorine, chlorine, bromine and iodine atoms. As the alkyl group, a linear or branched C _1-6 alkyl group such as a methyl group, an ethyl group, an n-propyl group, a sec-propyl group, an n-butyl group, an s-butyl group or a t-butyl group (preferably Is a C _1-4 alkyl group) and the like. Examples of the alkoxy group include C _1-6 alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group and t-butoxy group (preferably C _1-4 alkoxy group, especially C _1-2 alkoxy group). To be

The substitution position of R ¹ and R ² is not particularly limited and may be any of o-, m- and p-positions, but is usually p-position. The substitution position of the vinyl group is not particularly limited and may be any of o-, m-, and p-positions of the phenyl group, but it is usually the m- or p-position.

In the above formula (1), the bonding sites of the two benzene rings constituting the biphenylyl group are not particularly limited,
The other benzene ring may be at any of the o-, m-, and p-positions with respect to the benzene ring bonded to the nitrogen atom.
p-position. That is, a preferred biphenylyl group is
It is a 4-phenylphenyl group.

The vinyl monomer is, for example, a method for producing a triarylamine (eg, Tetrahedron Lett., 3
9 (1998) 2367) and aromatic coupling reactions (eg C
hem.Rev., 95 (1995) 2457).

More specifically, the vinyl compound (1) in which the biphenylyl group is a 4-phenylphenyl group is, for example,
The bis (biphenylyl) halogenation represented by the formula (1c) by the reaction between the aniline represented by the formula (1a) and the halogenated biphenyl compound represented by the formula (1b) and the halogenation reaction according to the following reaction scheme It can be obtained by producing phenylamine and reacting the obtained bis (biphenylyl) halogenated phenylamine (1c) with p- (dihydroxyboro) styrene represented by the formula (1f). The p- (dihydroxyboro) styrene represented by the formula (1f) can be obtained by preparing the corresponding Grignard reagent (1e) from the halostyrene (1d) and reacting it with boric acid.

[0028]

[Chemical 9]

(In the formula, X represents a halogen atom. R ¹ and R ² are the same as above.) The halogen atom represented by X includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a bromine atom and an iodine atom. (In particular, a bromine atom) is preferable.

The reaction between the aniline (1a) and the halogenated biphenyl compound (1b) can be carried out in the presence of a base, if necessary, using a catalyst. Halogenated biphenyl compound
The amount of (1b) used is usually about 1.5 to 2.5 mol, preferably about 1.8 to 2.2 mol, per 1 mol of aniline (1a).

As the base, an inorganic base such as an alkali metal alkoxide can be used. Examples of the alkali metal alkoxide include sodium methoxide,
Alkali metal C _1-6 alkoxides such as sodium ethoxide and sodium t-butoxide (especially sodium C
_1-4 alkoxide, etc.) and the like. The proportion of alkali metal alkoxide is based on 1 mol of aniline.
The amount is 0.5 to 10 moles, preferably 1 to 5 moles, and more preferably about 2 to 3 moles.

The reaction may be carried out in the presence of a catalyst. As the catalyst, a palladium catalyst such as bis (dibenzalacetone) palladium [Pd (dba) ₂ ] can be used. The palladium catalyst is, for example, 1,1′-
Bis (diphenylphosphino) ferrocene (DPPF)
It is desirable to use it in combination with a phosphorus ligand such as.
The amount of the palladium catalyst used can be selected from the range of 0.001 to 1 mol, preferably 0.001 to 0.5 mol, per 1 mol of aniline. When the palladium catalyst and the phosphorus ligand are used in combination, the ratio of the palladium catalyst and the phosphorus ligand is the former / the latter (molar ratio) = 1/10.
Is about 5/1, preferably 1/5 to 2/1, and more preferably about 1/3 to 1/1.

The reaction is carried out in a solvent inert to the reaction, for example, aliphatic hydrocarbons (hexane etc.), alicyclic hydrocarbons (cyclohexane etc.), aromatic hydrocarbons (benzene, toluene etc.), alcohols. (Methanol, ethanol, isopropyl alcohol, butanol, etc.), Esters (ethyl acetate, butyl acetate, isobutyl acetate, etc.), Ethers (dioxane, diethyl ether, tetrahydrofuran, etc.), Nitriles (acetonitrile, benzonitrile, etc.), sulfoxide It can be carried out in the presence of a group (such as dimethyl sulfoxide). The reaction solvent is usually a hydrocarbon, for example,
Aromatic hydrocarbons such as toluene are used.

By halogenating the biphenylamine compound produced by the reaction of the aniline (1a) and the halogenated biphenyl compound (1b), the compound represented by the formula (1c) can be produced. The biphenylamine compound produced by the reaction of aniline (1a) and the halogenated biphenyl compound (1b) may be separated and purified from the reaction mixture and subjected to the halogenation reaction, or may be subjected to the halogenation reaction without separation and purification. Good. The halogenation reaction can be carried out by a conventional method, for example, using N-halodicarboxylic acid imide [particularly N-bromosuccinimide (NBS)]. The amount of the N-halodicarboxylic acid imide used is, for example, 0.5 to 5 mol, preferably 0.
It is about 7 to 2 mol, and particularly about 1 to 2 mol. If necessary, the reaction may be carried out in the presence of a radical generator (eg, an azo compound such as azobisisobutyronitrile, an organic peroxide such as benzoyl peroxide). Furthermore, the reaction may be carried out in the presence of a solvent. Such solvents include amides (formamide, acetamide, dimethylformamide (DMF),
Dimethylacetamide etc.), halogenated hydrocarbons (chloroform etc.) etc. are included. Preferred solvents are halogenated hydrocarbons.

In the reaction between the aniline (1a) and the halogenated biphenyl compound (1b) and the halogenation reaction,
When a solvent is used, the reaction temperature can be selected from the range of 0 ° C to the reflux temperature, for example, 50 to 120 ° C, preferably 6 ° C.
It is about 0 to 100 ° C. The reaction can be carried out under normal pressure, reduced pressure or increased pressure. In addition, the reaction may be performed under an atmosphere of an inert gas (eg, nitrogen, argon, helium, etc.).

The bis (biphenylyl) halogenated phenylamine (1c) thus formed is, if necessary, used in a conventional method, for example, a separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, or the like. They may be separated and purified by a separation means combining these and then subjected to the reaction with p- (dihydroxyboro) styrene (1f).

The reaction between the produced bis (biphenylyl) halogenated phenylamine (1c) and p- (dihydroxyboro) styrene (1f) is usually carried out by using a base (alkali metal hydroxide such as sodium hydroxide or potassium hydroxide). Compounds, inorganic bases such as alkali metal carbonates such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and organic bases). This reaction may optionally be carried out in the presence of a catalyst. As the catalyst, a palladium catalyst such as palladium tetrakis (triphenylphosphine) can be used. The proportion of the base is 0.5 to 3 mol, preferably 0.8 to 3 mol, per 1 mol of bis (biphenylyl) halogenated phenylamine.
The amount is 2 mol, more preferably about 1 to 1.5 mol.
The ratio of the catalyst is 0.0001 to 0.5 mol, based on 1 mol of bis (biphenylyl) halogenated phenylamine,
It is preferably about 0.001 to 0.1 mol.

The reaction may be carried out in the presence of a solvent such as the reaction solvent exemplified above. The reaction temperature can be selected from the above reaction temperature range, and the reaction can be carried out under normal pressure, reduced pressure or elevated pressure. The reaction may be carried out under an atmosphere of an inert gas (eg, nitrogen, argon, helium, etc.).

The p- (dihydroxyboro) styrene represented by the formula (1f) can be obtained by preparing the corresponding Grignard reagent (1e) from the halostyrene (1d) and reacting it with boric acid. For example, p- (dihydroxyboro) styrene (1f) is, for example, p-halostyrene (p-bromostyrene, p-iodostyrene, etc.).
And magnesium metal are reacted in ether (acyclic ether such as diethyl ether, cyclic ether such as tetrahydrofuran) to give a Grignard reagent (p
-Vinylphenylmagnesium halide) (1e) is formed and the Grignard reagent is treated sequentially with orthoboric acid and water to give p- (dihydroxyboro) styrene.
(1f) can be obtained. As the reaction solvent, ether, which does not substantially contain water or alcohol is preferably used.

In the reaction of the compound (1d) with magnesium, the ratio of metallic magnesium can be selected from an excess amount, for example, in the range of about 1 to 10 mol, relative to 1 mol of p-halostyrene. The reaction temperature for obtaining the Grignard reagent (1e) is not particularly limited, and may be, for example, −20 ° C. to 50 ° C.
It is preferably about -10 ° C to 30 ° C.

The ratio of orthoboric acid to the Grignard reagent (1e) is 1 to 1 mol of the Grignard reagent (1e).
It is about 10 mol. The proportion of water depends on the Grignard reagent (1
e) It can be selected from an excess mole with respect to 1 mole, for example, a range of about 0.5 to 50 moles.

These reactions may be carried out under reduced pressure or increased pressure, but they are usually carried out under normal pressure. Also, the reaction is
Inert gas (eg nitrogen, argon, helium, etc.)
You may go under the atmosphere.

After completion of the reaction, the produced vinyl compound (1) is separated by a conventional method, for example, separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography or a combination thereof. It can be easily separated and purified by means.

Examples of the vinyl compound represented by the above formula (1) include 4- [bis (biphenyl-4-yl) amino] -4'-vinylbiphenyl; 4- [bis (4-halobiphenyl-4) -Yl) amino] -4'-vinylbiphenyl, for example 4- [bis (4-chlorobiphenyl-4)
-Yl) amino] -4'-vinylbiphenyl, 4- [bis (4-bromobiphenyl-4-yl) amino] -4 '
- vinyl biphenyl, 4- [bis (4-fluoro-biphenyl-4-yl) amino] -4'-vinyl biphenyl and the like; 4- [bis (4-C _1-6 alkyl-4-
Il) amino] -4′-vinylbiphenyl, for example 4
-[Bis (4-methylbiphenyl-4-yl) amino]
-4′-vinylbiphenyl, 4- [bis (4-ethylbiphenyl-4-yl) amino] -4′-vinylbiphenyl, 4- [bis (4-isopropylbiphenyl-4-yl) amino] -4′- Vinyl biphenyl, 4- [bis (4-t-butylbiphenyl-4-yl) amino]-
4'-vinyl biphenyl and the like; 4- [bis (4-C _1-6
Alkoxybiphenyl-4-yl) amino] -4'-vinylbiphenyl, such as 4- [bis (4-methoxybiphenyl-4-yl) amino] -4'-vinylbiphenyl, 4- [bis (4-ethoxybiphenyl) -4-yl)
Amino] -4'-vinylbiphenyl, 4- [bis (4-
t-butoxybiphenyl-4-yl) amino] -4′-
Examples thereof include vinyl biphenyl and the like, and compounds corresponding to these and having different substitution positions, for example, 4- [bis (biphenyl-4-yl) amino] -4′-vinyl biphenyl; 4- [bis (3-halobiphenyl -4-yl) amino] -4'-vinylbiphenyl; 4- [bis (3-C
_1-6 alkylbiphenyl-4-yl) amino] -4'-
Vinyl biphenyl; 4- [bis (3-C _1-6 alkoxybiphenyl-4-yl) amino] -4′-vinylbiphenyl and the like are also included.

Vinyl compound (1) thus obtained
Are useful in producing polymers that exhibit excellent hole transporting ability.

[Vinyl Polymer] The vinyl polymer of the present invention has a unit represented by the formula (2), and is obtained by polymerizing at least the vinyl compound (1) in the presence of a radical initiator. You can The vinyl compounds (1) can be used alone or in combination of two or more. That is, the vinyl polymer having the unit (2) may be a homopolymer or copolymer of the vinyl compound (1), or may be a copolymer of the vinyl compound (1) and another copolymerizable monomer. Good. Such a vinyl polymer has a π-electron side chain, and in addition to having an excellent hole transport function, it has high moldability and chemical stability. In particular, it has an extremely high glass transition temperature, and thus has high heat resistance. Can be greatly improved.

Examples of the copolymerizable monomer include aromatic vinyl monomers (styrene, vinyltoluene, styrene such as α-methylstyrene, or substitution products thereof), vinyl cyanide monomers (eg, acrylonitrile). Unsaturated polycarboxylic acids or acid anhydrides thereof (eg maleic acid, itaconic acid, citraconic acid or acid anhydrides thereof), imide monomers [eg maleimide, N-alkylmaleimide (eg N- C _1-4 alkylmaleimide etc.), N-cycloalkylmaleimide (eg N-
Cyclohexylmaleimide etc.), N-arylmaleimide (eg N-phenylmaleimide etc.)], acrylic monomer [eg (meth) acrylic acid, (meth)
(Meth) acrylic acid C _1-20 alkyl ester such as methyl acrylate], vinylcarbazoles (N-vinylcarbazole, dibromo-N-vinylcarbazole,
N-vinylcarbazolyl ethyl vinyl ether, etc.),
Vinylferrocenes, N, N-diarylaminoaryl C _2-4 alkyl (meth) acrylates (N, N-diphenylaminophenylethyl (meth) acrylate, etc.), condensed cyclic vinyl compounds (vinylpyrene, vinylperylene, perylenylethyl ( (Meth) acrylate etc.)
Can be exemplified. These copolymerizable monomers can be used alone or in combination of two or more. The amount of the copolymerizable monomer used in all the monomers is usually 0.1 to 30% by weight, preferably 1 to 20% by weight, more preferably 1 to 20% by weight.
It can be selected from the range of about 10% by weight.

Examples of the radical initiator include conventional radical initiators such as azo compounds [azobisisobutyronitrile (AIBN), dimethylazoisobutyrate, benzenediazonium chloride] and peroxides (benzoylperoxide). Oxide, di-t-butyl peroxide,
t-butyl perbenzoate, hydrogen peroxide, etc.) and the like. The ratio of the radical initiator is not particularly limited, and is 0.0 to 100 parts by weight of the total amount of vinyl monomers.
The amount is 1 to 20 parts by weight, preferably 0.1 to 10 parts by weight, and more preferably 1 to 5 parts by weight.

The polymerization can be carried out by a conventional method, for example, a solution polymerization method, a suspension polymerization method or the like, and a solution polymerization method is usually used. As the solvent for the solution polymerization, various solvents capable of dissolving the produced polymer, for example, hydrocarbons, esters, ketones, ethers and the like can be used, but usually aromatic hydrocarbons such as benzene and toluene. Is used.

The polymerization temperature is not particularly limited and is 0 to 200.
It can be selected from a wide range of about ℃. In the solution polymerization method, it is usually lower than the reflux temperature of the solvent, for example, room temperature (20 to 30 ° C.
Temperature) to 100 ° C, preferably about 50 to 100 ° C. The polymerization time is not particularly limited and may be 0.5 to 72 hours,
Preferably, it can be selected from the range of about 5 to 48 hours. The polymerization is usually performed in an inert gas atmosphere. Examples of the inert gas include nitrogen, helium, argon gas and the like.

The polymer formed is prepared by conventional methods, eg,
Separation and purification can be performed using a precipitation method using a solubilizing solvent and a poor solvent, a method such as column chromatography, or the like.

The glass transition temperature of the vinyl polymer (2) is, for example, 160 to 280 ° C. (eg 180 to 28).
0 ° C.), preferably 200-270 ° C. (eg 200
Up to 250 ° C), and more preferably 210 to 250 ° C. When such a vinyl polymer having a high Tg is used as a material for an organic EL device, an organic EL device having extremely high heat resistance can be obtained.

Weight average molecular weight M of vinyl polymer (2)
w (polystyrene conversion) is 5,000 to 500,000
It is 0, preferably about 5,000 to 100,000, preferably about 10,000 to 50,000. The number average molecular weight Mn is 5,000 to 500,000, preferably 5,000 to 100,000, more preferably 10,
It is about 000 to 40,000. The molecular weight distribution Mw / Mn of the vinyl polymer (2) is, for example, 1 to 3,
It is preferably about 1 to 2 (particularly 1 to 1.7).

Specific examples of such vinyl polymers include polymers having a unit represented by the following formula.

[0055]

[Chemical 10]

Such a vinyl polymer (2) can easily form a uniform and transparent amorphous glass by various film forming methods, for example, various coating methods such as spin coating and casting.

[Organic EL Element] The organic EL element of the present invention comprises a pair of electrodes and an organic layer interposed between the electrodes, and the organic layer has at least the unit represented by the formula (2). Contains vinyl polymer. The organic layer may be composed of at least one layer containing a vinyl polymer. In a typical example, the organic layer can be composed of a hole transport layer, a light emitting layer, and an electron transport layer, and may be composed of a hole transport layer and a light emitting electron transport layer.

The organic layer composed of the vinyl polymer usually has a hole transporting function and constitutes a hole transporting layer. The vinyl polymer (2) can also be used as a host layer for a luminescent dopant dye. The dopant dye is not particularly limited, and a luminescent compound described later, for example, a substituent (halogen atom,
C _1-4 alkyl group, C _1-4 alkoxy group, carbonyl group,
Condensed polycyclic hydrocarbons that may have amino groups, dialkylamino groups, cyano groups, etc. (rubrene, pyrene, chrysene, perylene, coronene, etc.), substituents (halogen atoms, C _1-4 alkyl groups) , C _1-4 alkoxy groups, carbonyl groups, amino groups, dialkylamino groups, cyano groups, etc., condensed heterocyclic compounds (quinacridones (dimethylquinacridone, diethylquinacridone, etc.), coumarin-6, etc.) And so on.

FIG. 1 is a schematic sectional view showing an example of the organic EL device of the present invention. In this example, the organic EL device includes a transparent electrode (anode) 2 formed on a transparent substrate (glass substrate or the like) 1, a hole transport layer 5 formed on the transparent electrode and containing the vinyl polymer, It has a laminated structure including a light emitting layer 4 formed on the hole transporting layer, an electron transporting layer 6 formed on the light emitting layer, and a cathode 3 formed on the electron transporting layer. The anode 2 and the cathode 3
Lead wires 9a and 9b are respectively connected to.

FIG. 2 is a schematic sectional view showing another example of the organic EL device of the present invention. In the organic EL device shown in FIG. 2, the transparent electrode 2 and the hole transport layer 5 are the same as those in the device shown in FIG.
An anode buffer layer (hole injection layer) 7 is interposed between the anode and the cathode. Furthermore, in FIG. 3 showing still another example of the organic EL device of the present invention, a hole transport layer 5 formed on a transparent electrode (anode) 2 and composed of a vinyl polymer,
Emissive electron transport layer 8 formed on this hole transport layer
And a cathode 3 formed on the luminescent electron transport layer 8 and having a laminated structure. Further, in the organic EL device shown in FIG. 4, in the device shown in FIG. 3, an anode buffer layer (hole injection layer) 7 is interposed between the transparent electrode (anode) 2 and the hole transport layer 5. .

In order to impart a light emitting function to the hole transport layer composed of the vinyl polymer having the unit (2), an organic compound or a polymer having a light emitting function may be added, A light emitting layer composed of an organic compound or a polymer having a light emitting function may be laminated on the hole transport layer. The electron-transporting layer can be composed of an organic compound or polymer having an electron-transporting function, and may be formed as a luminescent electron-transporting layer having both a light-emitting function and an electron-transporting function.

The hole transport layer may be composed of the vinyl polymer having the unit (2) alone or may be used in combination with the hole transport compound. Examples of the organic compound having a hole transport function include N, N′-diphenyl-N,
N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine (TPD), N, N'-diphenyl-N, N'-bis (1-naphthyl) -1,1 '-Biphenyl-4,4'-diamine (NPD), 1,1-bis [(di-4-tolylamino) phenyl] cyclohexane,
N, N, N ', N'-tetra (3-methylphenyl)-
1,3-diaminobenzene (PDA), 4,4 ', 4 "
-Tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), 4,4 ', 4 "-
Tris (1-naphthylphenylamino) triphenylamine (1-TNATA), 4,4 ′, 4 ″ -tris (2
-Naphthylphenylamino) triphenylamine (2-
TNATA), 4,4 ′, 4 ″ -tri (N-carbazolyl) triphenylamine (TCTA), 1,3,5-tris [4- (3-methylphenylphenylamino) phenyl] benzene (m-MTDAPB) And aromatic tertiary amines such as triphenylamine, phthalocyanines, etc. These hole transport compounds can be used alone or in combination of two or more.

As the organic compound or polymer having a light emitting function (light emitting compound), a compound which emits light when excited by electrons and / or holes can be used. Examples of the emission center-forming compound include bis (C _1-6 alkyl-benzoxazolyl) thiophene such as 2,5-bis (5-tert-butyl-2-benzoxazolyl) -thiophene and the above formula ( BMA-nT represented by 4b)
(N = 1 to 4), PhAMB-1 represented by the formula (4c)
C, coumarins such as T, Nile red, coumarin 6 and coumarin 7, 4- (dicyanomethylene) -2-methyl-6-
4 such as (p-dimethylaminostyryl) -4H-pyran
-(Dicyano C _1-4 alkylene) -2-C _1-4 alkyl-6
-(P-diC _1-4 alkylaminostyryl) -4H-pyran, containing at least one heteroatom selected from oxygen atom such as quinacridone (dimethylquinacridone, diethylquinacridone, etc.), nitrogen atom and sulfur atom Heterocyclic compounds (which may have a substituent (halogen atom, C _1-4 alkyl group, C _1-4 alkoxy group, carbonyl group, amino group, dialkylamino group, cyano group, etc.)); rubrene, pyrene , Condensed polycyclic hydrocarbons such as chrysene, perylene and coronene; tetra C _6-12 aryl-1,3-butadiene such as 1,1,4,4-tetraphenyl-1,3-butadiene (TPB); Bis (2- (4-C _1-4 alkylphenyl) C _2-4 alkynyl) benzene such as 1,4-bis (2- (4-ethylphenyl) ethynyl) benzene; 4,4 ′ -Bis (2,2'-diphenylvinyl) biphenyl and other bis (2,2'-diC
_{6-12 arylvinyl} ) biphenyl; N, N, N-tris (terphenylamine) (p represented by the above formula (4a)
-TTA) and the like. These luminescent compounds can be used alone or in combination of two or more.

Examples of the organic compound having an electron transporting function include oxadiazole derivatives [for example, 2-
(4-biphenyl) -5- (4-tert-butylphenyl)-
1,3,4-oxadiazole (PBD), 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (B
ND), 1,3-bis [5- (4-tert-butylphenyl) -1,3,4-oxadiazolyl] benzene (BPO
B), 1,3,5-tris [5- (4-tert-butylphenyl) -1,3,4-oxadiazolyl] benzene (compound represented by the above formula (3a): TPOB), 1,3,
5-tris [5- (1-naphthyl) -1,3,4-oxadiazolyl] benzene (TNOB) and other optionally substituted oxadiazole derivatives having a C _6-20 aryl group]; diphenoquinone Class [eg 3, 5,
Diphenoquinones that may have a substituent (C _1-10 alkyl group etc.) such as 3 ′, 5′-tetrakis-tert-butyldiphenoquinone; 1,2,3,4,5-pentaphenyl- 1,3-Cyclopentadiene (PPCP); tris (8-quinolinolato) aluminum (Alq ₃ ), bis (benzoquinolinolato) beryllium complex, tris (1
Quinolinolato complexes such as 0-hydroxybenzo [h] quinolinolato) beryllium complex; 1,3,5-tris [5-
(Dimesitylboryl) -2-thienyl] benzene, 5,
5'-bis (dimesitylboryl) -2,2'-bithiophene (compound represented by the formula (3b): BMB-2
T), 5,5 ''-bis (dimesitylboryl) -2,
2 ′: 5 ′, 2 ″ -terthiophene (the above formula (3c)
Compounds represented by: BMB-3T) and other thiophenes. Of these, oxadiazoles such as TPOB; quinolinolato complexes such as Alq ₃ ;
Preference is given to thiophenes such as 3,5-tris [5- (dimesitylboryl) -2-thienyl] benzene and BMB-2T and BMB-3T. The compounds having an electron transport function may be used alone or in combination of two or more. The Alq ₃ and 1,3,5-tris [5- (dimesitylboryl) -2-thienyl] benzene are respectively represented by the following formulas (3d) and (3e),
Compound (3e) was prepared by the present inventors in Chem. Lett., 2001,
Reported on page 614.

[0065]

[Chemical 11]

Examples of the organic polymer having an electron transporting function and / or a hole transporting function include, for example, a vinyl polymer having a hole transporting functional group and / or an electron transporting functional group in a main chain or a side chain, such as polyphenylene. Vinylenes [eg, C _6-12 arylene vinylene which may have a substituent (such as C _1-10 alkoxy group) such as polyphenylene vinylene, poly (2,5-dimethoxyphenylene vinylene), polynaphthalene vinylene, etc.] Or a copolymer]; polyphenylenes (particularly polyparaphenylenes) [eg, having a substituent such as polyparaphenylene or poly (2,5-dimethoxyparaphenylene) (C _1-10 alkoxy group, etc.) a homo- or copolymer] of phenylene; polythiophenes [poly (3-alkylthiophene) poly C _1-20, such as a Kill thiophenes, poly (3-cyclohexyl) poly C _3-20 cycloalkyl thiophenes such as poly (3- (4-n-hexyl-phenyl) thiophene) substituents such as (C _1-10 alkyl group) C _6-20 arylthiophenes and other thiophenes such as homopolymers or copolymers; poly C
Polyfluorenes such as _1-20 alkylfluorene; polyvinylcarbazole (eg, poly-N-vinylcarbazole (PVK)); polystyrenes (eg, poly-4-N, N-diphenylaminostyrene, poly-4-)
(5-naphthyl-1,3,4-oxadiazole) styrene); poly (meth) acrylamide (for example, poly (N- (p-diphenylamino) phenylmethacrylamide), poly (N, N'-diphenyl-). N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,
4'-diaminomethacrylamido) (PTPDMA)) or other vinyl polymer having a hole-transporting functional group and / or an electron-transporting functional group in the main chain or side chain; poly-C _1-4 alkylphenyl such as polymethylphenylsilane Examples thereof include silane; a polymer having an aromatic amine derivative in its side chain or main chain; or a copolymer thereof. These organic polymers having an electron transporting function and / or a hole transporting function may be used alone or in combination of two or more.

The material for the anode buffer layer (hole injection layer) is a conventional material for the anode buffer layer, for example, poly (3,4-ethylenedioxythiophene) (PEDOT) represented by the following formula (5a). And so on. PEDOT may be used alone, but the following formula (5
polystyrene sulfonate (PSS) represented by b)
May be used after being chemically doped. PEDOT doped with PSS is available as "BAYTRON P AI 4083" from Bayer Co., Ltd. in the state of water / methanol solution.

[0068]

[Chemical 12]

(In the formula, p and q represent integers of 1 or more) The thickness of layers (hole transport layer, light emitting layer, electron transport layer, light emitting electron transport layer, etc.) constituting the organic EL device is particularly There is no limitation, and each is 5 nm to 1 μm, preferably 10 to 80
0 nm, more preferably 30 to 500 nm, especially 50
Is about 300 nm.

A transparent conductive film (for example, an indium-tin-oxide (ITO) film, a tin oxide film, a zinc oxide film, an aluminum film, etc.) is used as the anode of the organic EL element, and a work is used as the cathode. A highly conductive metal having a small function (for example, magnesium, lithium, aluminum, or silver), calcium, or the like is used. When magnesium is used as the cathode, a small amount (for example, 1 to 10) is used in order to improve the adhesiveness with the organic EL device film.
Wt%) silver may be co-deposited. Preferred cathodes include magnesium-silver alloy electrodes, aluminum electrodes,
Examples thereof include a calcium electrode, a lithium / aluminum laminated electrode, a lithium fluoride / aluminum laminated electrode and the like.

The layers (hole transporting layer, light emitting layer, electron transporting layer, light emitting electron transporting layer, etc.) constituting the organic EL device are
It can be formed by a conventional method, for example, vapor deposition (vacuum vapor deposition method etc.), coating or casting (spin coating method etc.).
Further, a hole transport compound (hole transport component), a light emitting compound (light emitting component) and an electron transport compound (electron transport component)
When the components of each functional layer such as, for example, are inferior in film-forming property, they may be used in combination with a binder resin, if necessary, within a range that does not impair the hole transport function, the light emitting property, and the electron transport function. Examples of the binder resin include various thermoplastic resins [olefin resins such as polyethylene and polypropylene; styrene resins such as polystyrene and rubber-modified polystyrene (HIPS); acrylic resins (polymethyl (meth) acrylate); polyvinyl alcohol, etc. Vinyl alcohol-based polymer; Vinyl-based resin such as polyvinyl chloride;
Polyamide resin such as 6-nylon; Polyester resin [Alkylene arylate resin such as polyalkylene terephthalate (polyethylene terephthalate) etc.]; Fluorine resin; Polycarbonate; Polyacetal; Polyphenylene ether; Polyphenylene sulfide; Polyether sulfone; Polyether ketone Thermoplastic polyimide; thermoplastic polyurethane; norbornene-based polymer, etc., thermosetting resin [phenolic resin, amino resin (urea resin, melamine resin, etc.), thermosetting acrylic resin, unsaturated polyester resin, alkyd resin,
Diallyl phthalate resin, epoxy resin, silicone resin, etc.] can be used. These binder resins can be used alone or in combination of two or more. As the binder resin, a resin which has a film-forming ability and is soluble in a solvent is usually used.

The proportion of the binder resin in the hole transport layer, the light emitting layer, the electron transport layer and the light emitting electron transport layer is, for example,
It may be 1 to 70% by weight, preferably 5 to 50% by weight, more preferably 10 to 30% by weight.

The organic EL device of the present invention uses a conventional method, for example, the transparent electrode is formed on a transparent substrate, and vapor deposition and coating of a coating solution (for example, spin coating) are applied on the transparent electrode. By sequentially forming the above organic layers (hole transport layer, light emitting layer, electron transport layer and light emitting electron transport layer, anode buffer layer (hole injection layer)), and forming a cathode on the organic layer. Can be manufactured.

As the substrate, for example, a transparent substrate (eg, glass plate such as soda glass, non-alkali glass, quartz glass, etc., or polymer sheet or film such as polyester, polysulfone, polyether sulfone etc.) is used. Able and flexible organic EL
A polymer film can be used to fabricate the device.

The organic EL device of the present invention can be applied to various display devices, for example, mobile information communication devices such as mobile phones,
It is useful as a display device for data or image processing devices (computer systems) such as personal computers and television systems.

[0076]

The polymer obtained from the specific novel vinyl compound (1) is excellent in moldability, has a high glass transition temperature, is excellent in heat resistance, and is also excellent in the hole transport function. Therefore, the vinyl compound (1) and its polymer are useful as a material for an organic EL device, and can significantly improve the heat resistance of the organic EL device.

[0077]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples.

Example 1 (1) Vinyl compound: Synthesis of 4- [bis (4'-t-butylbiphenyl-4-yl) amino] -4'-vinylbiphenyl (VBAB) (a) Bis (4'- Synthesis of t-butylbiphenylyl) -4-bromophenylamine 21 mmol of aniline and 41 mmol of 4-t-butyl-4′-bromobiphenyl were dissolved in 120 ml of toluene, and to this solution was added 52 mmol of sodium t-butoxide, And 0.2 mmol of Pd (dba) ₂ and DPPF
Mixture with 0.3 mmol (Pd (dba) ₂ / DPP
F) was added, and the mixture was reacted at 90 ° C. for 15 hours in an inert gas (nitrogen gas) atmosphere. Then, the reaction product was separated by silica gel column chromatography, dissolved in 100 ml of chloroform, 10 mmol of N-bromosuccinimide (NBS) was added, and the temperature was adjusted to 1 at 25 ° C. in an inert gas (nitrogen gas) atmosphere. Reacted for hours. The reaction product is purified by silica gel column chromatography,
N, N-bis (4-t-butylbiphenyl) -N- (4
-Bromophenyl) amine was obtained.

(B) Synthesis of 4- (dihydroxyboro) styrene 16 mmol of 4-bromostyrene and magnesium 1
6 mmol was reacted with 50 ml of tetrahydrofuran in an inert atmosphere (nitrogen gas) at a temperature of 25 ° C. for 1 hour,
A Grignard reagent represented by the formula (1e) was prepared, 29 mmol of orthoboric acid was added to the reaction mixture, and the mixture was reacted in an inert atmosphere (nitrogen gas) at a temperature of 0 ° C. for 1 hour, and then 1 mol of water was added. Then, the mixture was stirred at a temperature of 80 ° C. for 24 hours to obtain p- (dihydroxyboro) styrene represented by the formula (1f).

(C) Synthesis of 4- [bis (4'-t-butylbiphenyl-4-yl) amino] -4'-vinylbiphenyl (VBAB) N, N-bis obtained in step (a) above (4-t-
Butylbiphenyl) -N- (4-bromophenyl) amine (7.6 mmol) and the p-obtained in step (b) above.
7.6 mmol of (dihydroxyboro) styrene was dissolved in 100 ml of toluene, and in the presence of 0.15 mmol of palladium tetrakis (triphenylphosphine) and 100 mmol of sodium carbonate in an inert atmosphere (nitrogen gas) at a temperature of 80 ° C. After reacting for 24 hours, VBAB was obtained.

The obtained VBAB was subjected to various spectrum measurements and elemental analysis. The spectrum was measured by the following method.

¹ H-NMR spectrum and ¹³ C-NMR
Spectra are deuterochloroform (CDCl ₃ )
Or deuterodimethyl sulfoxide (d ₆ -DMS
O) in tetramethylsilane (TMS) as an internal standard
Was measured by a Varian Unity-plus 300 NMR spectrometer. Mass spectrum: GCMS-QP5000
It measured using the spectrometer (made by Shimadzu Corporation). UV
For the visible spectrum and the fluorescence spectrum, the sample was dissolved in chloroform at a ratio of 1.5 × 10 ⁻⁵ mol / L, and the sample was dissolved in U-2010 spectrometer (manufactured by Hitachi Ltd.).
And F-4500 fluorescence spectrometer (manufactured by Hitachi Ltd.).

NMR (CDCl ₃ ) (ppm): 1.3
6 (s, 18H), 5.25 (d, 1H), 5.78
(D, 1H), 6.71 (dd, 1H), 7.28 (d
d, 2H), 7.44 (d, 4H), 7.47 (d, 4)
H), 7.51 (d, 4H) Mass spectrum (m / e): 611.5 Peak wavelength of absorption spectrum (uv): λmax352n
m (absorption coefficient εmax60250) Peak wavelength of fluorescence spectrum: Fmax436nm Elemental analysis (C H N): Calculated: C = 90.30%; H = 7.41%; N = 2.
29% measured value; C = 90.29%; H = 7.43%; N = 2.
33% (2) 2,2′-azobisisobutyronitrile (AIBN) as a radical initiator for synthesizing poly VBAB (PVBAB), and 0.01 mol of the vinyl compound VBAB obtained in the step (1), respectively. /
ml and a benzene solution containing 1.0 mol / ml in concentration were degassed, heated at 65 ° C. for 36 hours with shaking to polymerize, and then purified by reprecipitation with benzene and methanol three times, Yellow-white powdery PVBAB was obtained (yield 40% in terms of VBAB).

(A) Identification of PVBAB The obtained PVBAB was subjected to various spectrum measurements and elemental analyzes in the same manner as VBAB.

NMR (CDCl ₃ ) (ppm): 1.2
2-1.42 (m, 21H), 7.58-8.91.
(M, 24H) Peak wavelength of absorption spectrum (uv): λmax 346n
m (Extinction coefficient εmax 55000) Peak wavelength of fluorescence spectrum: Fmax 408 nm (b) Molecular weight Further, polystyrene-converted number average molecular weight Mn from GPC
Was 21,000 and the weight average molecular weight Mw was 39,000.

(C) Solubility When the solubility of PVBAB was evaluated under the condition of a temperature of 25 ° C., PVBAB was readily soluble in organic solvents such as benzene, THF, toluene and chloroform.

(D) Measurement of electron absorption spectrum PVBAB in benzene (1 × 10 ^-5 mol / ml)
70 nm in thickness by spin coating on the substrate using
A thin film of (700Å) was formed. An electronic absorption spectrum was measured using this thin film. Results are shown in FIG. As is clear from FIG. 5, the PVBAB thin film was uniform and transparent. Also, Optical Band Gap is 3.2 eV, and L
The energy level of UMO was -2.4 eV.

(E) Measurement of glass transition temperature (Tg) Differential scanning calorimetry was carried out under the conditions of a temperature rising rate of 5 ° C./min.
The glass transition temperature (Tg) of VBAB was measured. PVB
The DSC curve of AB is shown in FIG. From the DSC curve of FIG. 6, the Tg of PVBAB was 229 ° C., which was a very high glass transition temperature exceeding 200 ° C.

(F) Cyclic voltammogram Sweep using a dichloromethane solution containing PVBAB (1 × 10 ⁻³ mol / ml) and Bu ₄ ClO ₄ (1 × 10 ⁻⁴ mol / ml) as a supporting electrolyte. 100 mV speed
Cyclic voltammogram measurement was performed at s ^-1 . The results are shown in Fig. 7. Even after repeated potential sweep, not observed new oxidation wave and the reduction waves, the potential difference E _pa -E _pc between peaks of the oxide wave reduction wave is 0.062V, the i _{p c} / i _pa in formula Nicholson 1, it was found that the anodic oxidation process of PVBAB was electrochemically reversible and the radical cation species were stably present. The oxidation potential E _{1/2 of} PVBAB with respect to Ag / Ag + reference electrode was 0.58 vs. Ag
/ Ag ⁺ (0.01 mol / ml). Thus, PVBAB shows a low oxidation potential, and it is understood that it is suitable as a hole transport layer of an organic EL device.

(3) Preparation of Organic EL Device Using PVBAB as Hole Transport Layer The organic EL device shown in FIG. 4 was prepared according to the following procedure. That is, ITO (Indium-
(Tin-oxide) electrode 2 formed on the ITO substrate, poly (3,4-ethylenedioxythiophene) represented by the formula (5a) (PEDOT) polystyrene sulfonate represented by the formula (5b) (PSS). ) Is chemically doped [BAYTRON P AI 4083, manufactured by Bayer Co., Ltd.] by spin coating.
An anode buffer layer (hole injection layer) 7 having a thickness of 100 nm (1000Å) was formed.

Then, a tetrahydrofuran solution of PVBAB was applied onto the anode buffer layer by spin coating to form a hole transport layer having a thickness of 70 nm. further,
Tris (8-quinolinolato) aluminum (Alq ₃ ) represented by the formula (3d) is vacuum-deposited on the hole transporting layer to form a luminescent electron transporting layer having a thickness of 30 nm.
On this luminescent electron transport layer, a back electrode (area: 4 mm) made of an alloy of magnesium and silver (volume ratio 10: 1)
² ) (MgAg electrode) was vapor-deposited to obtain an organic EL device.

(4) Evaluation of organic EL device (a) Luminescent property When a voltage of 3 V or more was applied between the ITO electrode and the MgAg electrode of the manufactured organic EL device, green light emission was obtained. The EL spectrum of the organic EL element is Alq ₃
It is shown in FIG. 8 together with the fluorescence spectrum of the deposited film. As is clear from FIG. 8, the EL spectrum of the organic EL element is Al
Since it agrees well with the fluorescence spectrum of the q ₃ evaporated film,
It is considered that the light emitting species of the organic EL element is Alq ₃ .

Regarding the EL element, the maximum brightness was 11,500 cd · m ^{−2 at} 12 V and the brightness was 100 cd · m ² .
The luminous efficiency at m ⁻² was 2.0 lm · W ⁻¹ and the quantum yield was 1.0%, and high-luminance and highly efficient green light emission was obtained.

(B) Heat resistance Organic EL under reduced pressure of 0.1 Torr while changing temperature
The element was driven at a constant current, and the heat resistance was evaluated by measuring the luminance of the element at each temperature. The relationship between temperature and brightness is shown in FIG. Note that in FIG. 9, the brightness is attenuated as the temperature rises, but this attenuation is based on a decrease in the fluorescence quantum yield of the light emitting material and a decrease in the balance between holes and electrons. It is not based on material deterioration.
This was confirmed by the fact that when the element which has been heated once is returned to room temperature, the same luminance as before heating is restored again. As described above, the organic EL element of the example can be stably driven even in a high temperature range around 150 ° C.

Example 2 In the production of the organic EL of Example 1, the anode buffer layer was formed of PEDOT and the thickness of the Alq ₃ layer was set to 8.
An organic EL device was produced in the same manner as in Example 1 except that the thickness was 0 nm.

The obtained organic EL device exhibited green light emission based on the light emission of Alq ₃ as in Example 1 when a voltage of 3.0 V was applied. FIG. 10 shows the relationship between the applied voltage of the device and the emission brightness and current density. The maximum luminance of the obtained device is 11,500 cd · m ^-2 (12 V) and the luminance is 300.
The luminous efficiency at cd · m ⁻² was 2.0 lm · W ⁻¹ , which showed a good hole transporting ability.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an organic EL device of the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the organic EL element of the present invention.

FIG. 3 is a schematic cross-sectional view showing still another example of the organic EL element of the present invention.

FIG. 4 is a schematic sectional view showing another example of the organic EL element of the present invention.

5 is an electronic absorption spectrum of the PVBAB thin film obtained in Example 1. FIG.

6 is a DSC of PVBAB obtained in Example 1. FIG.
It is a curve.

FIG. 7 is a cyclic voltammogram of PVBAB obtained in Example 1.

FIG. 8 is an EL of the organic EL device obtained in Example 1.
It is a fluorescence spectrum of the spectrum and Alq ₃ vapor deposition film.

FIG. 9 is a graph showing changes in emission luminance of the organic EL device obtained in Example 1 with changes in temperature.

FIG. 10 is a graph showing the relationship between the applied voltage, the emission luminance, and the current density of the organic EL device obtained in Example 2.

[Explanation of symbols]

1 ... Glass substrate 2 ... Anode 3 ... Cathode 4 ... Light emitting layer 5 ... Hole transport layer 6 ... Electron transport layer 7 ... Anode buffer layer 8 ... Luminescent electron transport layer 9a, 9b ... Lead wire

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuyuki Moriwaki             3-13-13-306 Onohara East, Minoh City, Osaka Prefecture (72) Inventor Kenji Okumoto             Osaka Prefecture Toyonaka City Miyayamacho 4-1-32 F-term (reference) 3K007 AB14 AB18 CB04 DB03                 4H006 AA01 AB46 AB92                 4J100 AB07P BA04P BA05P BA28P                       BB00P BC43P CA01 DA25                       DA61 JA32 JA43

Claims (6)

[Claims] 1. A vinyl compound represented by the following formula (1). [Chemical 1] (In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.) 2. R¹And R²But hydrogen atom and halogen source
Child, straight chain or branched chain C _1-6Alkyl group or C_1-6Arco
The vinyl compound according to claim 1, which is a xy group. 3. A vinyl polymer having a unit represented by the following formula (2). [Chemical 2] (In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.) 4. The vinyl polymer according to claim 3, which has a glass transition temperature of 200 to 250 ° C. 5. An organic electroluminescence device having at least one organic layer containing the vinyl polymer according to claim 3 between a pair of electrodes. 6. The organic electroluminescence device according to claim 5, wherein the organic layer is a hole transport layer containing a vinyl polymer.