NOVEL POLYMERIZABLE MONOMER AND POLYMER OF THE POLYMERIZABLE MONOMER, AND MATERIAL FOR ORGANIC DEVICE, HOLE INJECTION/TRANSPORT MATERIAL AND ORGANIC ELECTROLUMINESCENT ELEMENT EACH COMPRISING THE POLYMER

TECHNICAL FIELD

The invention relates to a novel polymerizable monomer having a polymerizable functional group (a functional group which causes a chemical reaction in which two or more molecules of one unit compound are bonded to form a compound of which the molecular weight is an integral multiple of the unit compound), a polymer having it as a repeating unit, a material for an organic device, a hole-injecting/transporting material and an organic electroluminescence device each comprising the polymer.

An organic electroluminescence (EL) device is a self-emission device utilizing the principle that a fluorescent compound emits light by the recombination energy of holes injected from an anode and electrons injected from a cathode when an electric field is impressed. Since C. W. Tang et al. of Eastman Kodak Co. reported a low-voltage driven organic EL device in the form of a stacked type device (Non-Patent Document 1), studies on organic EL devices wherein organic materials are used as the constituent materials have actively been conducted. Tang et al. use tris(8-quinolinolato)aluminum in an emitting layer and a triphenyldiamine derivative in a hole-transporting layer. The advantages of the stack structure are to increase injection efficiency of holes to the emitting layer, to increase generation efficiency of excitons generated by recombination by blocking electrons injected from the cathode, to confine the generated excitons in the emitting layer, and so on. Like this example, as the structure of the organic EL device, a two-layered type of a hole-transporting (injecting) layer and an electron-transporting emitting layer, and a three-layered type of a hole-transporting (injecting) layer, an emitting layer and an electron-transporting (injecting) layer are widely known. In such stack structure devices, their device structures and fabrication methods have been contrived to increase recombination efficiency of injected holes and electrons.

In recent years, practical application of a display or an illumination device using such organic EL device has been actively studied. A reduction in cost and an increase in screen size can be mentioned as important subjects for realizing such practical application. Under such circumstances, as compared with conventional vacuum deposition type organic EL devices, there is an increasing demand for a coating (solution) type organic EL device. A coating type organic EL device is expected to have such advantages that utilization efficiency of raw materials is high, film formation for attaining a large screen is facilitated, and costs incurred for apparatuses are decreased since no vacuum system is required.

As organic EL materials for a coating type organic device, low-molecular materials and high-molecular materials can be mentioned. In order to attain uniform coating and to obtain a device with a stacked structure, high molecular materials are thought to be preferable. In particular, development of a material for a high-molecular hole-transporting (injecting) layer which can function as the common layer of a display or an illumination device has been desired.

As the material for the high-molecular hole-transporting (injecting) layer, a polymer having a repeating unit obtained by substituting a low-molecular hole-transporting material with a vinyl group is known (Documents 1 to 10).

However, in an organic EL device having the above-mentioned polymer in a hole-transporting (injecting) layer, device performance such as life (half life) and luminous efficiency is not necessarily sufficient. In particular, there is a problem that, if such organic EL devices are subjected to high-luminance or high-temperature driving, which is practical in applications such as a display and an illuminator, the life thereof is significantly shortened.

RELATED ART DOCUMENTS
Patent Documents

Patent Document 1: JP-A-H07-90255

Patent Document 2: JP-A-H08-54833

Patent Document 3: JP-A-H08-269133

Patent Document 4: JP-A-2001-098023

Patent Document 5: JP-A-2002-110359

Patent Document 6: JP-A-2003-313240

Patent Document 7: JP-A-2004-059743

Patent Document 8: JP-A-2006-237592

Patent Document 9: JP-A-2008-198989

Patent Document 10: JP-A-2008-218983

Non-Patent Document

Non-Patent Document 1: C. W. Tang, S. A. Vanslyke, Applied Physics Letters, Vol. 51, Page 913, 1987

SUMMARY OF THE INVENTION

An object of the invention is to provide a novel polymerizable monomer and a polymer having it as a repeating unit which is useful as a material for a coating type organic device, in particular as a hole-injecting/transporting material, as well as to provide an organic EL device which is improved in device performance such as life and luminous efficiency and hence is suited for practical application.

That is, the invention provides the following polymerizable monomer, a polymer having it as a repeating unit, an organic device material, a hole-injecting/transporting material, a material for an organic electroluminescence device (organic EL device) and an organic EL device each comprising the polymer.

1. A polymerizable monomer represented by the following formula (1) which is substituted by one or more groups comprising a polymerizable functional group:

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wherein Ar¹and Ar⁴to Ar⁶are independently a substituted or unsubstituted aryl group having 6 to 40 carbon atoms that form a ring (hereinafter referred to as “ring carbon atoms”);

Ar², Ar³and L¹are a substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms; and

the substituents for L¹and Ar¹to Ar⁶when they are substituted are independently one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 atoms that form a ring (hereinafter referred to as “ring atoms”), a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group and a hydroxyl group.

2. A polymerizable monomer represented by the following formula (2) which is substituted by one or more groups comprising a polymerizable functional group:

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wherein Ar⁷to Ar¹⁰are independently a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms, and at least one of Ar⁷to Ar¹⁰is an aryl group containing a fused polycyclic aromatic group having 10 to 40 ring carbon atoms;

the substituents for Ar⁷to Ar¹⁰when they are substituted are independently one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group and a hydroxyl group; and

L²is a group selected from groups represented by the following formula:

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wherein R²to R⁷are independently a group selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group, and a hydroxyl group;

g and h are independently an integer of 0 to 4; and

i and j are independently an integer of 0 to 3.

3. A polymerizable monomer represented by the following formula (3) which is substituted by one or more groups comprising a polymerizable functional group:

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wherein Ar¹³to Ar¹⁵are independently a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms;

Ar¹²and L³area substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms;

Ar¹¹is a substituted or unsubstituted aryl group comprising a fused polycyclic aromatic group having 10 to 40 ring carbon atoms; and

the substituents for L³and Ar¹¹to Ar¹⁵when they are substituted are independently one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group and a hydroxyl group.

4. The polymerizable monomer according to one of 1 to 3, wherein at least one of the aryl groups bonded to the nitrogen atoms in the formulas (1) to (3) is selected from the group consisting of groups represented by the following formulas (4) to (7):

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wherein R⁸to R¹⁵are independently one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atom, a halogen atom, a nitro group, a cyano group and a hydroxyl group;

a, c, d, e and g are independently an integer of 0 to 4;

b, f and h are independently an integer of 0 to 3;

Ar¹⁶is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms or a heterocyclic group having 3 to 30 ring atoms;

L⁴to L⁶are independently a single bond or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms; and

the substituents for L⁴to L⁶when they are substituted are one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group and a hydroxyl group.

5. The polymerizable monomer according to one of 1, 3 and 4 wherein L¹and L³to L⁶are independently selected from the group consisting of a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenylylene group, a substituted or unsubstituted terphenylylene, group and a substituted or unsubstituted fluorenylylene group.

6. The polymerizable monomer according to one of 1 to 5, which is substituted by only one group comprising a polymerizable functional group.

7. The polymerizable monomer according to one of 1 to 6, wherein at least one of Ar¹and Ar⁴to Ar⁶in the formula (1), at least one of Ar⁷to Ar¹⁰in the formula (2) and at least one of Ar¹¹and Ar¹³to Ar¹⁵in the formula (3) are substituted by the group comprising a polymerizable functional group.

8. The polymerizable monomer according to 7, wherein an aromatic group at a terminal in the formulas (1) to (3) is substituted by the group comprising a polymerizable functional group, and the polymerizable functional group and the part other than the terminal aromatic group in the formulas (1) to (3) are bonded to the terminal aromatic group at the para position.

9. The polymerizable monomer according to one of 1 to 8, wherein the group comprising a polymerizable functional group is selected from the groups of the following (i) to (v):

(i) a group comprising a vinyl group or a vinylidene group shown below:

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wherein R¹⁷is a hydrogen atom, an alkyl group having 1 to 50 carbon atoms or a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms; L⁷is a divalent linking group; and n is an integer of 0 or 1:

(ii) a group comprising an N-maleimide group shown below:

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wherein L⁸is a divalent linking group and n is an integer of 0 or 1:

(iii) a group comprising a norbornenyl group shown below:

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wherein L⁹is a divalent linking group and n is an integer of 0 or 1:

(iv) a group comprising an acetylenyl group shown below:

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wherein R¹⁸is a hydrogen atom, an alkyl group having 1 to 50 carbon atoms or a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms; L¹⁰is a divalent linking group; and n is an integer of 0 or 1: and

(v) a group comprising a cyclopolymerizable or ring-opening polymerizable functional group selected from the group consisting of a group having a substituted or unsubstituted norbornene skeleton other than the group (iii), a group having a substituted or unsubstituted epoxy group or a substituted or unsubstituted oxetane group; a functional group having a lactone structure or a lactum structure; a cyclooctatetraene group or a 1,5-cyclooctadiene group; and 1,ω-diene group, an o-divinylbenzene group and a 1,ω-diyne group.

10. The polymerizable monomer according to 9, wherein L⁷to L¹⁰independently comprise one linking group or a linking group formed by bonding, in an arbitral order, of two or more linking groups, the linking group being selected from the following divalent linking groups:

—L¹¹—, —O—, —C(═O)—, —C(═O)O—, —OC(═O)—, —C(═O)NR¹⁹—, —NR²⁰C(═O)—, —NR²¹—, —S—, —C(═S)—

wherein L¹¹is one group or a group formed by bonding, in an arbitral order, of two or more groups, the group being selected from the group consisting of a substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms, a substituted or unsubstituted divalent heterocyclic group having 3 to 40 ring atoms, a substituted or unsubstituted alkylene group having 1 to 50 carbon atoms, a substituted or unsubstituted vinylene group, a substituted or unsubstituted vinylidene group and an ethynylene group; and

R¹⁹to R²¹are independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 50 carbon atoms and a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms.

11. A polymer comprising a repeating unit derived from one or two or more selected from the group consisting of the polymerizable monomers according to one of 1 to 10.

12. A material for an organic device comprising the polymer according to 11.

13. A hole-injecting/transporting material comprising the polymer according to 11.

14. A material for an organic electroluminescence device comprising the polymer according to 11.

15. An organic electroluminescence device comprising one or a plurality of organic thin film layers comprising an emitting layer between a cathode and an anode and at least one layer of the organic thin film layers comprising the polymer according to 11.

16. The organic electroluminescence device according to 15 wherein the organic thin film layers comprise one or both of a hole-transporting layer and a hole-injecting layer, and one or both of the hole-transporting layer and the hole-injecting layer comprises the polymer according to 11.

17. The organic electroluminescence device according to 15 or 16 wherein one or both of the hole-transporting layer and the hole-injecting layer comprises the polymer according to 11 as a main component.

18. The organic electroluminescence device according to one of 15 to 17 wherein the emitting layer comprises one or both of a styrylamine compound and an arylamine compound.

19. The organic electroluminescence device according to one of 16 to 18 wherein the organic thin film layers comprise one or both of the hole-transporting layer and the hole-injecting layer and one or both of the hole-injecting layer and the hole-transporting layer comprises an acceptor material.

20. The organic electroluminescence device according to one of 15 to 19 which can emit blue light.

According to the invention, it is possible to provide a novel polymerizable monomer which is useful as a hole-injecting/transporting material of an organic device, in particular, an organic EL device or the like, and a polymer having it as a repeating unit, and it is possible to provide an organic EL device improved in device performance such as life and luminous efficiency and suffers only slight deterioration even when it is subjected to high-temperature driving which is particularly practical in applications of a display or illumination, and hence is suited for practical use.

Further, since a hole-injecting/transporting layer can be formed homogenously by a coating method, the invention is effective for a reduction in cost and an increase in screen size in applications such as a display and illumination.

MODE FOR CARRYING OUT THE INVENTION

The structures represented by the formulas (1) to (3) given below are hole-transporting units improved in hole mobility and heat resistance. However, these units have poor solubility in a solvent as they are, and hence, they could not ensure the viscosity required of a coating liquid and homogeneity of a coating film (pinholeless). Therefore, only a deposition process can be applied, and hence, an increase in screen size and a reduction in cost of a display or an illumination device in the future are difficult to be realized.

According to the invention, by further adding a polymerizable functional group to the hole-transporting units improved in hole mobility and heat resistance as those represented by the formulas (1) to (3), solubility of the monomer in a polymerization solvent is enhanced, whereby a polymer can be synthesized at a high yield. Further, the resulting polymer has high solubility in a solvent, and hence, the viscosity required of a coating liquid and homogeneity of a coating film (pinholeless) can be ensured, whereby an increase in size and a reduction in cost of a display or illumination in the future become possible.

Further, the resulting polymer is effective as a hole-injecting/transporting material of an organic device, in particular, an organic EL device or the like. By using such material, it has become possible to provide an organic EL device which is improved in device performance such as life and luminous efficiency and hence, useful in applications of a display or illumination. In particular, it has become possible to provide a practical organic EL device which suffers only a slight degree of deterioration even if it is subjected to practical high-temperature driving.

The invention will be explained in detail according to the following embodiments.

Embodiment 1: Novel polymerizable monomer (hereinafter referred to as polymerizable monomers (1) to (3))

Embodiment 2: Polymer

Embodiment 3: Material comprising the polymer (a material for an organic device, a hole-injecting/transporting material, a material for an organic electroluminescence device)

Embodiment 4: Organic electroluminescence device

Embodiment 1
Poymerizable Monomer (1)

A polymerizable monomer represented by the following formula (1) which is substituted by one or more groups comprising a polymerizable functional group:

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In the formula, Ar¹and Ar⁴to Ar⁶are independently a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms;

Ar², Ar³and L¹are a substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms; and

the substituents for L¹and Ar¹to Ar⁶when they are substituted are independently one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group and a hydroxyl group.

The monomer represented by the formula (1) is characterized in Ar¹—Ar²—Ar³—, in particular. Due to the presence of an aryl group having at least three aromatic rings, the resulting polymer has improved solubility in a solvent, whereby homogeneity of a coating film is improved, and high temperature resistance of an organic device, in particular, an organic EL device is improved. As examples of this Ar¹—Ar²—Ar³—, a p-terphenyl-4-yl group, a p-terphenyl-3-yl group and a p-terphenyl-2-yl group are preferable, with a p-terphenyl-4-yl group being more preferable. The reason therefor is as follows. Interaction between side chains is suppressed to reduce the amount of an excimer or an exciplex generated. As a result, device performance such as hole-transporting properties of the polymer is improved, and the polymerization reaction ratio is improved to decrease the amount of monomers remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

In the formula (1), it is preferred that at least one of the aryl groups bonded to the nitrogen atoms, that is Ar⁴to Ar⁶, be selected from the group consisting of groups represented by the following formulas (4) to (7). If the aryl group bonded to the nitrogen atoms is any one of these groups, in addition to the above-mentioned effects brought about by the use of the structure of the formula (1), the resulting polymer has improved device performance such as hole-transporting properties as well as improved reduction resistance (resistance to electrons), durability and life of an organic device, in particular, an organic EL device, are improved.

Groups represented by the following formulas (4) to (7) may be substituted by the group comprising a polymerizable functional group which substitutes the unit represented by the formula (1). However, in order to further improve reduction resistance (resistance to electrons), it is more preferred that groups represented by the following formulas (4) to (7) be not substituted by a group comprising the polymerizable functional group, but only Ar¹⁶be substituted.

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In the formula, R⁸to R¹⁵are independently one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atom, a halogen atom, a nitro group, a cyano group and a hydroxyl group;

a, c, d, e and g are independently an integer of 0 to 4;

b, f and h are independently an integer of 0 to 3;

L⁴to L⁶are independently a single bond or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms; and

L⁴is substituted at an arbitral position of the 1^stto the 4^thpositions of dibenzofuran or dibenzothiophene. Of these positions, the 2^ndand 4^thpositions are preferable, with the 4^thposition being more preferable. L⁶is substituted at an arbitral position of the 1^stto the 4^thpositions of carbazole, and the 2^ndand the 3^rdpositions are preferable, with the 3^rdposition being further preferable. The reasons therefor are as follows. Synthesis is easy, and due to easiness in purification, a high degree of purity can be attained easily, and as a result, durability and life of an organic device, in particular, an organic EL device, are improved.

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Dibenzofuran Substitution Position

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Carbazole Substitution Position

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Dibenzothiophene Substitution Position

It is preferred that L¹in the formula (1) and L⁴to L⁶in the formulas (4) to (7) be independently selected from the group consisting of a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenylylene group, a substituted or unsubstituted terphenylylene group and a substituted or unsubstituted fluorenylylene group.

By selecting these groups, durability and life of an organic device, in particular, an organic EL device, are further improved.

A polymerizable functional group is a functional group which causes a chemical reaction in which two or more molecules of one unit compound are bonded to form a compound of which the molecular weight is an integral multiple of the unit compound.

Examples of the polymerizable functional group include a group containing a double bond such as a substituted or unsubstituted vinyl group, a group which causes an addition reaction such as a substituted or unsubstituted acetylene group (ethynyl group), a group which causes a ring-opening polymerization such as a substituted or unsubstituted norbornene skeleton-containing group (norbornenyl group), a group having a cyclic ether such as a substituted or unsubstituted epoxy group or a substituted or unsubstituted oxetane group; a group which causes a ring-opening polymerization such as a functional group having a lactone structure or a lactum structure; and a group which causes a cyclopolymerization such as 1,ω-diene.

It is essential that the polymerizable monomer represented by the formula (1) be substituted by one or more groups comprising a polymerizable functional group. It is preferred that the monomer represented by the formula (1) be substituted by only one group comprising a polymerizable functional group. The reason therefor is as follow. If the polymerizable monomer is substituted by only one group comprising a polymerizable functional group, it is possible to conduct a polymerization reaction without causing a cross-linking reaction. Therefore, after the formation of a polymer, the polymer can be subjected to a purification treatment such as reprecipitation, and as a result, there is no monomer remaining unreacted or other impurities, exerting only small adverse effects on durability and life of an organic device, in particular, an organic EL device.

It is preferred that at least one of the aryl groups represented by Ar¹and Ar⁴to Ar⁶in the formula (1) be substituted by the group comprising a polymerizable functional group.

It is preferred that a terminal aromatic ring contained in Ar¹and Ar⁴to Ar⁶in the formula (1) be substituted by the group comprising a polymerizable functional group. It is more preferred that a terminal aromatic ring contained in Ar¹in the formula (1) be substituted by the group comprising a polymerizable functional group. The reason therefor is as follows. Due to such substitution, solubility of the monomer or the resulting polymer in a solvent is improved, and as a result, not only homogeneity of a coating film of the polymer is improved but also the polymerization reaction ratio becomes high to decrease the amount of a monomer remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

Further, it is preferred that the polymerizable functional group and the part other than the terminal aromatic group contained in the aryl groups in the formula (1) (Ar¹and Ar⁴to Ar⁶) be bonded to the terminal aromatic group at the para position (for example, if the terminal aromatic group is a phenylene group, at the 1^stand 4^thpositions). The reason therefor is as follows. Due to such bonding, interaction between side chains is suppressed to reduce the amount of an excimer or an exciplex generated. As a result, device performance such as hole-transporting properties of the polymer is improved, and the polymerization reaction ratio is improved to decrease the amount of monomers remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

It is preferred that the group comprising a polymerizable functional group be selected from the following groups of (i) to (v).

Such polymerizable functional group has high reactivity, and hence, exhibits a high polymerization ratio. As a result, the amount of a monomer remaining unreacted is decreased, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

(i) A group comprising a vinyl group or a vinylidene group shown below:

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wherein R¹⁷is a hydrogen atom, an alkyl group having 1 to 50 carbon atoms or a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms; L⁷is a divalent linking group; and n is an integer of 0 or 1.

(ii) A group comprising an N-maleimide group shown below:

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wherein L⁸is a divalent linking group and n is an integer of 0 or 1.

(iii) A group comprising a norbornenyl group shown below:

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wherein L⁹is a divalent linking group and n is an integer of 0 or 1.

(iv) A group comprising an acetylenyl group shown below.

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For example, a group having a substituted or unsubstituted norbornene skeleton other than the group (iii), a group having a cyclic ether such as a group having a substituted or unsubstituted epoxy group or a substituted or unsubstituted oxetane group; a functional group having a lactone structure or a lactum structure; a group which causes ring-opening polymerization such as cyclooctatetraene group or a 1,5-cyclooctadiene group; and a group which causes cyclopolymerization such as a 1,ω-diene group, an o-divinylbenzene group and a 1,ω-diyne group can be mentioned.

In the group comprising the polymerizable functional group of the above formulas (i) to (iv), it is preferred that L⁷to L¹⁰be independently one linking group or a linking group formed by bonding, in an arbitral order, of two or more linking groups, the linking group being selected from the group consisting of the following divalent linking groups:

—L¹¹—, —O—, —C(═O)—, —C(═O)O—, —OC(═O)—, —C(═O)NR¹⁹—, —NR²⁰C(═O)—, —NR²¹—, —S—, —C(═S)—

L¹¹is one group or a group formed by bonding, in an arbitral order, of two or more groups, the group being selected from the group consisting of a substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms, a substituted or unsubstituted divalent heterocyclic group having 3 to 40 ring atoms, a substituted or unsubstituted alkylene group having 1 to 50 carbon atoms, a substituted or unsubstituted vinylene group, a substituted or unsubstituted vinylidene group and an ethynylene group; and

—C(═O)— denotes a carbonyl bond and —C(═S)— denotes a thiocarbonyl bond.

By selecting such linking group, solubility of the monomer in a polymerization solvent is improved, the polymerization reaction ratio is improved to decrease the amount of monomers remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, are improved. Further, since solubility of the polymer in a coating solvent is improved to enable a homogenous coating film to be obtained, such linking group is suited to film formation for obtaining a large-size screen.

Specific examples of the groups relating to the formulas (1), (4) to (7) and the groups comprising a polymerizable functional group represented by the formulas (i) to (iv) and the substituents are given below.

Example of an Aryl Group:

Specific examples of the aryl groups include a phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, biphenyl-2-yl group, biphenyl-3-yl group, biphenyl-4-yl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, p-t-butyl phenyl group, p-(2-phenylpropyl)phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenyl-4-yl group, 4″-t-butyl-p-terphenyl-4-yl group, fluorene-1-yl group, fluorene-2-yl group, fluorene-3-yl group and fluorene-4-yl group.

Of these, a phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, biphenyl-2-yl group, biphenyl-3-yl group, biphenyl-4-yl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, a p-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, fluorene-2-yl group and fluorene-3-yl group are preferable, with a phenyl group, 1-naphthyl group, 2-naphthyl group, m-tolyl group, p-tolyl group, fluorene-2-yl group and fluorene-3-yl group being more preferable.

Examples of an Arylene Group:

Specific examples of an arylene group are selected from divalent groups obtained by removing one aromatic hydrogen group from the aryl group mentioned above.

Of these, a 1,4-phenylene group, a 1,3-phenylene group, a 1,4-naphthylene group, a 1,10-anthrylene group, a 4,4′-biphenylylene group, a 3,4′-biphenylylene group, a 4,3′-biphenylylene group, a 4,4″-p-terphenylylene group, a 3,4″-p-terphenylylene group, a 4,3″-p-terphenylylene group, a 1,4-tolylene group, a 4,4″-fluorenylene group and a 3,3″-fluorenylene group are preferable, with a 1,4-phenylene group, a 1,4-naphthylene group, a 1,10-anthrylene group, a 4,4″-biphenylylene group, a 3,4′-biphenylylene group, a 4,4″-p-terphenylylene group, a 2,7-fluorenylene group and a 3,6-fluorenylene group being more preferable.

Examples of the substituent when the aryl group and the arylene group, etc. mentioned above are substituted and examples of other groups are given below. The same groups as those mentioned above are omitted.

Specific examples of an alkyl group include a methyl group, an ethyl group, a propyl group, and an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 2-hydroxyisobutyl group, a 1,2-dihydroxyethyl group, a 1,3-dihydroxyisopropyl group, a 2,3-dihydroxy-t-butyl group and a 1,2,3-trihydroxypropyl group. A methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a tert-butyl group are preferable.

Of these, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s-butyl group and a t-butyl group are preferable.

Specific examples of a cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, a cyclohexylethyl group, a 4-fluorocyclohexyl group, a 1-adamantyl group, 2-adamantyl group, a 1-norbonyl group and a 2-norbonyl group. A cyclopentyl group and a cyclohexyl group are preferable.

The alkoxy group, the cycloalkoxy group and the aryloxy group are a group in which an oxygen atom is intervened at the substitution position of the alkyl group, the cycloalkyl group and the aryl group which are mentioned above.

The aralkyl group is a group in which the above-mentioned alkyl group is substituted by the above-mentioned aryl group.

Specific examples of the trialkylsilyl group include a trimethylsilyl group, a vinyldimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a propyldimethylsilyl group, a tributylsilyl group, a t-butyldimethylsilyl group, a tripentylsilyl group, a triheptylsilyl group and a trihexylsilyl group. A trimethylsilyl group and a triethylsilyl group are preferable. The silyl group may be the same or different alkyl groups.

Specific examples of the triarylsilyl group include a triphenylsilyl group and a trinaphthylsilyl group. A triphenylsilyl group is preferable. The silyl group may be substituted by the same or different aryl groups.

Specific examples of the dialkylarylsilyl group include a dimethylphenylsilyl group, a diethylphenylsilyl group, a dipropylphenylsilyl group, a dibutylphenylsilyl group, a dipentylphenylsilyl group, a diheptylphenylsilyl group, a dihexylphenylsilyl group, a dimethylnaphthylsilyl group, a dipropylnaphthylsilyl group, a dibutylnaphthylsilyl group, a dipentylnaphthylsilyl group, a diheptylnaphthylsilyl group, a dihexylnaphthylsilyl group, a dimethyl anthrylsilyl group, a diethylanthrylsilyl group, a dipropylanthrylsilyl group, a dibutylanthrylsiyl group, a dipentylanthrylsilyl group, a diheptylanthrylsilyl group, a dihexylanthrylsilyl group and a diphenylmethyl group. A dimethylphenylsilyl group and a diethylphenylsilyl group are preferable.

Specific examples of the alkyldiarylsilyl group include a methyldiphenylsilyl group, an ethyldiphenylsilyl group, a propyldiphenylsilyl group, a butyldiphenylsilyl group, a pentyldiphenylsilyl group and a heptyldipheny silyl group. A methyldiphenylsilyl group and an ethyldiphenylsilyl group are preferable.

Examples of the heterocyclic group include a 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthridinyl group, 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, 1,7-phenanthrolin-2-yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group, 1,7-phenanthrolin-6-yl group, 1,7-phenanthrolin-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group, 1,8-phenanthrolin-2-yl group, 1,8-phenanthrolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group, 1,8-phenanthrolin-6-yl group, 1,8-phenanthrolin-7-yl group, 1,8-phenanthrolin-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9-phenanthrolin-2-yl group, 1,9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1,9-phenanthrolin-6-yl group, 1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl group, 1,10-phenanthrolin-3-yl group, 1,10-phenanthrolin-4-yl group, 1,10-phenanthrolin-5-yl group, 2,9-phenanthrolin-1-yl group, 2,9-phenanthrolin-3-yl group, 2,9-phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group, 2,9-phenanthrolin-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group, 2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl group, 2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl group, 2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group, 2,7-phenanthrolin-5-yl group, 2,7-phenanthrolin-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group, 2,7-phenanthrolin-10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiadinyl group, 2-phenothiadinyl group, 3-phenothiadinyl group, 4-phenothiadinyl group, 10-phenothiadinyl group, 1-phenoxadinyl group, 2-phenoxadinyl group, 3-phenoxadinyl group, 4-phenoxadinyl group, 10-phenoxadinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-furazanyl group, 2-thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group, 3-(2-phenylpropyl)pyrrol-1-yl group, 2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group, 2-t-butyl-1-indolyl group, 4-t-butyl-1-indolyl group, 2-t-butyl-3-indolyl group and 4-t-butyl-3-indolyl group.

Of these, a 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group and 9-carbazolyl group are preferable.

As the mono- or dialkylamino group, an amino group which is substituted by the above-mentioned alkyl group is mentioned.

As the mono- or diarylamino group, an amino group which is substituted by the above-mentioned aryl group is mentioned.

As the alkylarylamino group, an amino group which is substituted by the above-mentioned alkyl group and the above-mentioned aryl group is mentioned.

Specific examples of a halogen atom include fluorine, chlorine and bromine.

Of these, fluorine is preferable. The reason therefor is that, since fluorine allows the surface tension of the resulting polymer to be lowered, a more homogeneous coating film can be formed.

Further, in the alkyl group, the cycloalkyl group, the aryl group, the alkoxy group, the cycloalkoxy group, the aryloxy group having 6 to 30 ring carbon atoms, the aralkyl group, the heterocyclic group, the mono- or dialkylamino group, the mono- or diarylamino group, the alkylarylamino group, the trialkylsilyl group, the triarylsilyl group, the dialkylarylsilyl group or the alkyldiarylsilyl group as mentioned above, the hydrogen atom may be substituted by a halogen atom. Of the halogen atoms, a fluorine atom is preferable. The reason therefor is that, since fluorine allows the surface tension of the resulting polymer to be lowered, a more homogeneous coating film can be formed.

Polymerizable Monomer (2)

A polymerizable monomer represented by the following formula (2) which is substituted by one or more groups comprising a polymerizable functional group:

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In the formula, Ar⁷to Ar¹⁰are independently a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms, and at least one of Ar⁷to Ar¹⁰is an aryl group containing a fused polycyclic aromatic group having 10 to 40 ring carbon atoms;

L²is a group selected from groups represented by the following formula:

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In the formula, R²to R⁷are independently a group selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group, and a hydroxyl group;

g and h are independently an integer of 0 to 4; and

i and j are independently an integer of 0 to 3.

The characteristic feature of the monomer represented by the formula (2) is that at least one of Ar⁷to Ar¹⁰is a substituted or unsubstituted aryl group containing a fused polycyclic aromatic group having 10 to 40 ring carbon atoms, and L²is a substituted or unsubstituted biphenylylene or a substituted or unsubstituted fluorenylylene group represented by the above formulas. By this feature, solubility of the resulting polymer in a solvent is improved, whereby not only homogeneity of a coating film is improved but also durability to high temperatures of an organic device, in particular, an organic EL device, is improved.

Further, in the formula (2), it is preferred that at least one of the aryl groups bonded to the nitrogen atoms (N), i.e. at least one of Ar⁷to Ar¹⁰, be selected from the group consisting of groups represented by the above formulas (4) to (7). By allowing at least one of Ar⁷to Ar¹⁰to be a group selected from the group consisting of groups represented by the above formulas (4) to (7), in addition to the above-mentioned advantageous effects brought by the use of the structure of the formula (2), not only device performance such as hole-transporting properties but also reduction resistance (resistance to electrons) of the resulting polymer is improved, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

The groups represented by the formulas (4) to (7) may be substituted by the group comprising a polymerizable functional group. However, in order to further improve reduction resistance (resistance to electrons), it is more preferred that the groups represented by the following formulas (4) to (7) be not substituted by the group comprising a polymerizable functional group and that only Ar¹⁶be substituted.

At least one of Ar⁷to Ar¹⁰is an aryl group containing a fused polycyclic aromatic ring group having 10 to 40 ring carbon atoms.

As examples of the aryl group containing the fused polycyclic aromatic ring having 10 to 40 ring carbon atoms, naphthalene, phenanthrene, fluoranthene, anthracene, pyrene, perylene, coronene, chrysene, picene, dinaphthyl, trinaphthyl, phenylanthracene, diphenylanthracene, fluorene, triphenylene, rubicene, benzanthracene, dibenzanthracene, acenaphthofluoranthene, tribenzopentaphene, fluoranthenofluoranthene, benzodifluoranthene, benzofluoranthene and diindenoperylene may be mentioned. Some aromatic rings may be hydrogenated. In particular, naphthalene, phenanthrene, fluoranthene, anthracene, pyrene, perylene, coronene, chrysene, phenylanthracene, diphenylanthracene, fluorene and acenaphthofluoranthene are preferable.

Examples of the aryl group, the arylene group, the substituent and other groups in the formula (2) are the same as those for the polymerizable monomer (1).

It is preferred that at least one of the aryl groups in the formula (2), i.e. at least one of Ar⁷to Ar¹⁰, be substituted by the group comprising a polymerizable functional group. It is more preferred that a terminal aromatic ring contained in the aryl groups in the formula (2) be substituted by the group comprising a polymerizable functional group. The reason therefor is as follows. Due to such substitution, solubility of the monomer or the resulting polymer in a solvent is improved, and as a result, not only homogeneity of a coating film of the polymer is improved but also the polymerization reaction ratio becomes high to decrease the amount of a monomer remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

Further, it is preferred that the polymerizable functional group and the part other than the terminal aromatic group contained in the aryl groups in the formula (2) be bonded to the terminal aromatic group at the para position (for example, if the terminal aromatic group is a phenylene group, at the 1^stand 4^thpositions). The reason therefor is as follows. Due to such bonding, Interaction between side chains is suppressed to reduce the amount of an excimer or an exciplex generated. As a result, device performance such as hole-transporting properties of the polymer is improved, and the polymerization reaction ratio is improved to decrease the amount of monomers remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device are improved.

It is preferred that other groups than the aryl group containing a fused polycyclic aromatic ring having 10 to 40 ring carbon atoms be substituted by the group comprising a polymerizable functional group. The reason therefor is that, by such substitution, the introduction position or number of a polymerizable functional group can be selected easily, and a polymerizable functional group can be introduced easily, whereby the polymerization reaction ratio of the resulting monomer is improved.

Polymerizable Monomer (3)

A polymerizable monomer represented by the following formula (3) which is substituted by one or more groups comprising a polymerizable functional group:

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In the formula, Ar¹³to Ar¹⁵are independently a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms;

Ar¹²and L³area substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms;

Ar¹¹is a substituted or unsubstituted aryl group comprising a fused polycyclic aromatic group having 10 to 40 ring carbon atoms; and

The characteristic feature of the monomer represented by the formula (3) is that Ar¹¹is a substituted or unsubstituted aryl group having a fused polycyclic aromatic group having 10 to 40 ring carbon atoms. By this feature, solubility of the resulting polymer in a solvent is improved, whereby not only homogeneity of a coating film is improved but also durability to high temperatures of an organic device, in particular, an organic EL device, is improved.

Further, in the formula (3), it is preferred that at least one of the aryl groups bonded to the nitrogen atoms (N), i.e. at least one of Ar¹³to Ar¹⁵, be selected from the group consisting of groups represented by the above formulas (4) to (7). By allowing at least one of Ar¹³to Ar¹⁵to be a group selected from the group consisting of groups represented by the above formulas (4) to (7), in addition to the above-mentioned advantageous effects brought by the used of the structure of the formula (3), not only device performance such as hole-transporting properties but also reduction resistance (resistance to electrons) of the resulting polymer is improved, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

The polymerizable functional group and the group comprising a polymerizable functional group are the same as those for the polymerizable monomer (1). The groups represented by the following formulas (4) to (7) may be substituted by the group comprising a polymerizable functional group. However, In order to further improve reduction resistance (resistance to electrons), it is more preferred that the groups represented by the following formulas (4) to (7) be not substituted by the group comprising a polymerizable functional group and that only Ar¹⁶be substituted.

Examples of the aryl group, the arylene group, the substituent and other groups in the formula (3) are the same as those for the polymerizable monomer (1) and examples of the aryl group containing a fused polycyclic aromatic ring having 10 to 40 ring carbon atoms are the same as those for the polymerizable monomer (2).

The polymerizable functional group and the group comprising a polymerizable functional group are explained above referring to the polymerizable monomer (1). Therefore, a detailed explanation thereof is omitted. It is preferred that the monomer be substituted by only one group comprising a polymerizable functional group. The reason therefor is as follows. If the polymerizable monomer is substituted by only one group comprising a polymerizable functional group, it is possible to conduct a polymerization reaction without causing a cross-linking reaction. Therefore, after the formation of a polymer, the polymer can be subjected to a purification treatment such as reprecipitation, and as a result, there is no monomer remaining unreacted or other impurities, exerting only small adverse effects on durability and life of an organic device, in particular, an organic EL device. It is preferred that at least a terminal aromatic ring group contained in at least one of the aryl groups in the formula (3), i.e. Ar¹¹and Ar¹³to Ar¹⁵, be substituted by the group comprising a polymerizable functional group. The reason therefor is as follows. Due to such substitution, solubility of the monomer or the resulting polymer in a solvent is improved, and as a result, not only homogeneity of a coating film of the polymer is improved but also the polymerization reaction ratio becomes high to decrease the amount of a monomer remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, is improved.

It is more preferred that a terminal aromatic ring group contained in Ar¹³to Ar¹⁵be substituted by the group comprising a polymerizable functional group. The reason therefor is that, by such substitution, the introduction position or number of a polymerizable functional group can be selected easily, and a polymerizable functional group can be introduced easily, whereby the polymerization reaction ratio of the resulting monomer can be improved.

Further, it is preferred that the polymerizable functional group and the part other than the terminal aromatic group contained in the aryl groups in the formula (3), i.e. Ar¹¹and Ar¹³to Ar¹⁵, be bonded to the terminal aromatic group at the para position (for example, if the terminal aromatic group is a phenylene group, at the 1^stand 4^thpositions). The reason therefor is as follows. Due to such bonding, interaction between side chains is suppressed to reduce the amount of an excimer or an exciplex generated. As a result, device performance such as hole-transporting properties of the polymer is improved, and the polymerization reaction ratio is improved to decrease the amount of monomers remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

In the formulas (3) and (4) to (7), it is preferred that L³to L⁶are independently are a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenylylene group, a substituted or unsubstituted terphenylylene group or a substituted or unsubstituted fluorenylylene group.

By selecting such functional group, durability and life of an organic device, in particular, an organic EL device, will be further improved.

Examples of the polymerizable monomers (1) to (3) of the invention will be given below:

Example of the Polymerizable Monomer (1):

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Example of the Polymerizable Monomer (2)

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Example of the Polymerizable Monomer (3):

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Example of the polymerizable monomer (1) to (3) in which at least one of the aryl groups bonded to the nitrogen atoms (N) is a group represented by the above formulas (4) to (7):

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Embodiment 2
Polymer

The polymer of the invention is a polymer having a repeating unit derived from one or two or more selected from the group consisting of the polymerizable monomers (1) to (3) of the invention.

That is, the polymer of the invention comprises one of the followings:

(a) a homopolymer having a repeating unit derived from one monomer selected from the group consisting of the polymerizable monomers (1) to (3)

(b) a copolymer having a repeating unit derived from two or more monomers selected from the group consisting of the polymerizable monomers (1) to (3)

(c) a copolymer having a repeating unit derived from one or two ore more monomers selected from the group consisting of the polymerizable monomers (1) to (3) and a repeating unit derived from other monomers

The copolymer (c) contains preferably 50 mol % or more, more preferably 70 mol % or more, of the monomer component of the polymerizable monomers (1) to (3). If the amount of the polymerizable monomer component of the invention is smaller than 50 mol %, advantageous effects of the polymerizable monomer of the invention may not be fully exhibited.

No specific restrictions are imposed on the bonding manner of the copolymers (b) and (c), and they may be any of a random copolymer, an alternate copolymer, a block copolymer, a graft copolymer, a random block copolymer, a comb-like copolymer and a star-like copolymer. However, the polymer of the invention is more directed to a liner copolymer than a cross-linked or net-work polymer.

The copolymer (c) may be any of a random copolymer containing a repeating unit A (for example, the polymerizable monomers (1) to (3)) and a repeating unit B (other monomers) (-ABBABBBAAABA-), an alternate copolymer (-ABABABABABAB-), a block copolymer (-AAAAAABBBBBB-) and a graft copolymer (either the repeating unit A or the repeating unit B may be the main chain or the side chain).

No specific restrictions are imposed on the molecular weight of the polymer of the invention. The polymer of the invention includes polymers with various molecular weights ranging from an oligomer equals to or larger in size than a dimer to an unltra high molecular weight polymer. The polymer of the invention has a number average molecular weight (Mn) of preferably 10³to 10⁸, more preferably 5×10³to 10⁶. The weight average molecular weight (Mw) thereof is preferably 10³to 10⁸, more preferably 5×10³to 10⁶. Although there are no specific restrictions on the molecular weight distribution represented by Mw/Mn, an Mw/Mn of 10 or less is preferable, with 3 or less being further preferable. If the molecular weight is too large, gelation occurs to make formation of a homogeneous film impossible in the fabrication of a device. A too small molecular weight makes control of solubility difficult. The both molecular weights were obtained by using a size exclusion chromatography (SEC) and by calibrating with standard polystyrene.

The copolymer (c) may contain a repeating unit derived from a monomer other than the above-mentioned polymerizable monomers (1) to (3). That is, it may contain a repeating unit derived from other monomers.

As examples of other monomers, in particular, a polymerizable monomer in which a monoamine-, diamine- or triamine-based aromatic compound shown below is substituted by a group containing a polymerisable group is preferable.

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Ar^ato Ar^eare independently a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms; L^aand L^bare independently a substituted or unsubstituted arylene group having 6 to 40 ring carbon atoms; examples of the aryl group and the arylene group are the same as those mentioned above;

substituents of Ar^ato Ar^eand L^aand L^bare independently one or more groups selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, an aryloxy group having 6 to 30 ring carbon atoms, an aralkyl group having 7 to 31 carbon atoms wherein the aryl part has 6 to 30 ring carbon atoms, a heterocyclic group having 3 to 30 ring atoms, a mono- or dialkylamino group having an alkyl group having 1 to 20 carbon atoms, a mono- or diarylamino group having an aryl group having 6 to 30 ring carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 18 to 30 ring carbon atoms, a dialkylarylsilyl group or an alkyldiarylsilyl group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, an alkylarylamino group having 8 to 30 carbon atoms wherein the aryl part has 6 to 20 ring carbon atoms, a halogen atom, a nitro group, a cyano group and a hydroxyl group.

In this way, solubility of the polymer in a coating solvent or hole-injecting and transporting properties can be improved.

It is particularly preferred that a terminal aromatic group of Ar^ato Ar^ebe substituted by the group containing a polymerizable functional group.

Further, it is further preferred that the polymerizable functional group and the part other than the terminal aromatic group in the above formula be bonded to the terminal aromatic group at the para position (for example, if the terminal aromatic group is a phenylene group, at the 1^stand 4^thpositions). The reason therefor is as follows. Due to such bonding, interaction between side chains is suppressed to reduce the amount of an excimer or an exciplex generated. As a result, device performance such as hole-transporting properties of the polymer is improved, and the polymerization reaction ratio is improved to decrease the amount of monomers remaining unreacted, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

The polymer of the invention can be produced by subjecting a monomer to an addition polymerization, a cyclopolymerization or a ring-opening polymerization.

Although no specific restrictions are imposed on the polymerization method for the polymer of the invention, radical polymerization, ionic polymerization, living polymerization, radical living polymerization, coordination polymerization or the like can be used, for example. In particular, radical polymerization or cationic polymerization is preferable.

As the polymerization initiator of radical polymerization, an azo compound and a peroxide can be mentioned, for example. Azobisisobutyronitrile (AIBN), an azobisisobutylic acid diester derivative and benzoyl peroxide (BPO) are preferable.

As the initiator of cationic polymerization, various strong acids (p-toluenesulfonic acid, trifluoromethanesulfonic acid, or the like) and lewis acid are preferable.

Although no specific restrictions are imposed on the polymerization solvent, an aromatic hydrocarbon solvent such as toluene and chlorobenzene, a halogenated hydrocarbon solvent such as methylene chloride, dichloromethane and chloroform, an ether solvent such as teterahydrofuran and dioxane, an amide solvent such as dimethylformamide, an alcohol solvent such as methanol, an ester solvent such as ethyl acetate and a ketone solvent such as acetone, or the like can be given. By selecting a suitable solvent, it is possible to conduct solution polymerization in which polymerization is conducted in a homogeneous system and precipitation polymerization in which a generated polymer is precipitated.

These organic solvents may be used either singly or in combination of two or more. It is preferred that the organic solvent be used in an amount such that the concentration of the monomer be 0.1 to 90% by weight, more preferably 1 to 50% by weight.

The polymerization temperature is not particularly restricted insofar as a reaction medium keeps the liquid state. The polymerization temperature is preferably −100 to 200° C., with 0 to 120° C. being more preferable. The reaction time varies depending on reaction conditions such as reaction temperature, but one hour or longer is preferable, with 2 to 500 hours being more preferable.

As for the polymerization product according to a known method, a reaction solution is added to a lower alcohol such as methanol to allow precipitation, and precipitates thus deposited are filtered out and dried, whereby an intended polymer can be obtained. If the purity of the polymer is low, purification may be conducted by a normal method such as re-precipitation, Soxhlet continuous extraction and column chromatography.

By conducting purification in this way, an unreacted monomer and impurities such as a polymerization catalyst are removed, whereby durability and life of an organic device, in particular, an organic EL device, are improved.

Embodiment 3
Material Comprising the Polymer

The polymer obtained by the above-mentioned method can be suitably used as a material for the following organic devices, a hole-injecting and transporting material and a material for an organic electroluminescence device. The polymer enables an organic device obtained, in particular, an organic EL device, to have improved device properties such as life and luminous efficiency. In addition, even when a device is subjected to high-temperature driving which is practical in applications of a display or illumination, the display suffers only a slight degree of deterioration, whereby an organic EL device suited to practical use can be provided.

Further, since a homogeneous hole-injecting/transporting layer can be formed by the coating method, a material comprising the polymer of the invention is suited for a reduction in cost or an increase in screen size in applications of a display or illumination.

Examples of the organic device include, in addition to an organic EL device, an organic TFT, a photoelectric conversion device such as organic solar cell and an image sensor.

Examples of the organic EL device include a planar emitting body such as a flat panel display of a wall-hanging television, general or special illumination devices, backlight of a copier, a printer, or a liquid crystal display, light sources for instruments, a display panel and a navigation light.

The polymer of the invention can also be used as an electrophotographic photoreceptor.

Embodiment 4
Organic Electroluminescence Device

The organic electroluminescence device of the invention (hereinafter often referred to as the organic EL device) comprises one or a plurality of organic thin film layers comprising an emitting layer between a cathode and an anode wherein at least one layer of the organic thin film layers comprises the polymer of the invention.

In the organic EL device of the invention, it is preferred that the organic thin film layers comprise one or both of a hole-transporting layer and a hole-injecting layer, and that one or both of the hole-transporting layer and the hole-injecting layer comprise the polymer of the invention.

Further, it is more preferred that the polymer of the invention be contained as the main component of one or both of the hole-transporting layer and the hole-injecting layer.

In the organic EL device of the invention, it is preferred that the emitting layer contain one or both of a styrylamine compound and an arylamine compound.

If one or both of the hole-transporting layer and the hole-injecting layer is included, it is preferred that an acceptor material be contained in one or both of the hole-injecting layer and the hole-transporting layer. It is particularly preferred that an acceptor material be contained in a layer which is adjacent to an anode.

By allowing an acceptor material to be contained, density of holes in the hole-injecting/transporting layer can be improved or hole transportability can be improved. As a result, the resulting organic EL device has a lowered driving voltage and carrier balance is improved to enable the resulting organic EL device to have a long life.

An acceptor is preferably an organic compound which has an electron attracting substituent or an electron deficient ring.

As the electron-attracting substituent, a halogen, CN—, a carbonyl group, an aryl boron group or the like can be given, for example.

Examples of the electron-deficient ring include, though not limited thereto, a compound selected from the group consisting of 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 2-imidazole, 4-imidazole, 3-pyrazole, 4-pyrazole, pyridazine, pyrimidine, pyrazine, cinnoline, phthalazine, quinazoline, quinoxaline, 3-(1,2,4-N)-triazolyl, 5-(1,2,4-N)-triazolyl, 5-tetrazolyl, 4-(1-O,3-N)-oxazole, 5-(1-O,3-N)-oxazole, 4-(1-S,3-N)-thiazole, 5-(1-S,3-N)-thiazole, 2-benzoxazole, 2-benzothiazole, 4-(1,2,3-N)-benzotriazole, and benzimidazole.

It is preferred that the above-mentioned acceptor be a quinodimethane derivative.

Compounds represented by the following formulas (1a) to (1i) can be given as a quinoid derivative. It is more preferred that the quinoid derivative be a compound represented by the formulas (1a) and (1b):

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In the formulas (1a) to (1i), R¹to R⁴⁸are independently a hydrogen atom, a halogen atom, a fluoroalkyl group, a cyano group, an alkoxy group, an alkyl group or an aryl group, with hydrogen and a cyano group being preferable.

In the formulas (1a) to (1i), X is an electron-attracting group which is formed of one of the following structures (j) to (p). The structures (j), (k) and (l) are preferable.

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In the formula, R⁴⁹to R⁵²are independently hydrogen, a fluoroalkyl group, an alkyl group, an aryl group or a heterocyclic group. R⁵⁰and R⁵¹may be bonded to form a ring.

In the formulas (1a) to (1i), Y is —N═ or —CH═.

As the halogen represented by R¹to R⁴⁸, fluorine and chlorine are preferable.

As the fluoroalkyl group represented by R¹to R⁴⁸, a trifluoromethyl group and a pentafluoroethyl group are preferable.

As the alkoxyl group represented by R¹to R⁴⁸, a methoxy group, an ethoxy group, an iso-propoxy group, and a tert-butoxy group are preferable.

As the alkyl group represented by R¹to R⁴⁸, a methyl group, an ethyl group, a propyl group, an iso-propyl group, a tert-butyl group and a cyclohexyl group are preferable.

As the aryl group represented by R¹to R⁴⁸, a phenyl group and a naphthyl group are preferable.

Examples of the fluoroalkyl group, the alkyl group and the aryl group represented by R⁴⁹to R⁵²are the same those represented by R¹to R⁴⁸.

The heterocyclic ring represented by R⁴⁹to R⁵²is preferably a substituent represented by the following formulas:

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If R⁵⁰and R⁵¹form a ring, X is preferably a substituent represented by the following formula:

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In the formula, R⁵¹′ and R⁵²′ are independently a methyl group, an ethyl group, a propyl group and a tert-butyl group.

Specific examples of the quinoid derivative include the following compounds:

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The content of an acceptor contained in the acceptor-containing layer is preferably 1 to 100 mol % relative to the entire layer, more preferably 50 to 100 mol %.

Further, the hole-injecting/transporting layer may contain fullerene. As examples of fullerene, a carbon cluster compound represented by C60 can be given. C70, C76, C78, C82, C84, C90, C96 or the like other than C60 may also be mentioned.

It is preferred that the organic EL device of the invention emit blue light. An organic EL device which emits blue light generally has a shorter device life. However, by using the polymer of the invention in the organic thin film layers, life of the device is hardly shortened even if it is subjected to practical high-luminance and high-temperature driving.

The representative device structures of the organic EL device of the invention are given below.

(1) Anode/emitting layer/cathode

(2) Anode/hole-injecting layer/emitting layer/cathode

(3) Anode/emitting layer/electron-injecting layer/cathode

(4) Anode/hole-injecting layer/emitting layer/electron-injecting layer/cathode

(5) Anode/organic semiconductor layer/emitting layer/cathode

(6) Anode/organic semiconductor layer/electron blocking layer/emitting layer/cathode

(7) Anode/organic semiconductor layer/emitting layer/adhesion-improving layer/cathode

(8) Anode/hole-injecting layer/hole-transporting layer/emitting layer/electron-injecting layer/cathode

(9) Anode/insulating layer/emitting layer/insulating layer/cathode

(10) Anode/inorganic semiconductor layer/insulating layer/emitting layer/insulating layer/cathode

(11) Anode/organic semiconductor layer/insulating layer/emitting layer/insulating layer/cathode

(12) Anode/insulating layer/hole-injecting layer/hole-transporting layer/emitting layer/insulating layer/cathode

(13) Anode/insulating layer/hole-injecting layer/hole-transporting layer/emitting layer/electron-injecting layer/cathode

Of these, the structure (8) is preferably used. The device structure is, however, not limited to those mentioned above.

The organic EL device of the invention is fabricated by stacking on a transparent substrate a plurality of layers having the layer structures as mentioned above. The transparent substrate as referred to herein is a substrate for supporting the organic EL device, and is preferably a flat and smooth substrate having a 400-to-700-nm-visible-light transmittance of 50% or more.

Specific examples thereof include glass plates and polymer plates. Examples of the glass plate, in particular, include soda-lime glass, barium/strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass and quartz. Examples of the polymer plate include polycarbonate, acrylic polymer, polyethylene terephthalate, polyethersulfone and polysulfone.

<Anode>

As the conductive material used for the anode of the organic EL device of the invention, one having a work function larger than 4 eV is suitable, and carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum and palladium, alloys thereof, oxidized metals such as tin oxide and indium oxide which are used for an ITO substrate and a NESA substrate and an organic conductive resin such as a polythiophene and polypyrrole are used.

As the conductive material used for the cathode, one having a work function smaller than 4 eV is suitable, and magnesium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese, aluminum, lithium fluoride and alloys thereof are used, but usable materials are not limited thereto. Representative examples of the alloy include, though not limited thereto, a magnesium/silver alloy, a magnesium/indium alloy and a lithium/aluminum alloy. The amount ratio of an alloy is controlled by the temperature of the deposition source, atmosphere, vacuum degree or the like, and a suitable ratio is selected. If necessary, the anode and the cathode each may be formed of two or more layers.

This cathode can be formed by making the electrode substances into a thin film by vapor deposition, sputtering or some other methods.

In the case where light is emitted from the emitting layer through the cathode, the cathode preferably has a light transmittance of larger than 10%.

The sheet resistance of the cathode is preferably several hundreds Ω/□ or less, and the film thickness thereof is usually from 10 nm to 1 μm, preferably from 50 to 200 nm.

In the organic EL device, pixel defects based on leakage or a short circuit are easily generated since an electric field is applied to a super thin film. In order to prevent this, it is preferable to insert an insulative thin layer between the pair of electrodes.

Examples of the material used in the insulating layer include aluminum oxide, lithium fluoride, lithium oxide, cesium fluoride, cesium oxide, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, aluminum nitride, titanium oxide, silicon oxide, germanium oxide, silicon nitride, boron nitride, molybdenum oxide, ruthenium oxide and vanadium oxide. A mixture or a laminate of these materials may also be used.

The emitting layer of the organic EL device has the following functions (1), (2) and (3) in combination.

(1) Injection function: function of allowing injection of holes from the anode or hole-injecting layer and injection of electrons from the cathode or electron-injecting layer upon application of an electric field

(2) Transporting function: function of moving injected carriers (electrons and holes) due to the force of an electric field

(3) Emitting function: function of allowing electrons and holes to recombine to emit light

Note that electrons and holes may be injected into the emitting layer with different degrees, or the transportation capabilities indicated by the mobility of holes and electrons may differ. It is preferable that the emitting layer move either electrons or holes.

The polymer of the invention may be used in the plurality of organic thin film layers as mentioned above, if necessary. Further, an emitting material, a doping material, a hole-injecting material or an electron-injecting material which are known in the art can be used. It is also possible to use the polymer of the invention as the doping material. By allowing the organic thin film layers as mentioned above to be formed of a plurality of layers, the organic EL device can be prevented from a lowering of luminance or life by quenching. If necessary, an emitting material, a doping material, a hole-injecting material or an electron-injecting material may be used in combination. Further, by using a doping material, improvement in luminance or luminous efficiency can be attained, and red or blue emission can be obtained. Moreover, the hole-injecting layer, the emitting layer and the electron-injecting layer may respectively be formed of two or more layers. In this case, in the case of the hole-injecting layer, a layer which injects holes from the electrode is referred to as the hole-injecting layer and a layer which receives holes from the hole-injecting layer and transports the holes to the emitting layer is referred to as the hole-transporting layer. Similarly, in the case of the electron-injecting layer, a layer which injects electrons from the electrode is referred to as the electron-injecting layer and a layer which receives electrons from the electron-injecting layer and transports the electrons to the emitting layer is referred to as the electron-transporting layer. Each of these layers is selected and used according to the factors such as the energy level, heat resistance, adhesiveness to the organic layers or the metal electrode of the material.

Examples of the host material or the doping material which can be used in the emitting layer together with the polymer of the invention include, though not limited thereto, fused polymer aromatic compounds such as naphthalene, phenanthrene, rubrene, anthracene, tetracene, pyrene, perylene, chrysene, decacyclene, coronene, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, fluorene, spirofluorene, 9,10-diphenenylanthracene, 9,10-bis(phenylethyl)anthracene and 1,4-bis(9′-ethynylanthracenyl)benzene and derivatives thereof, organic metal complexes such as tris(8-quinolinolate)aluminum and bis-(2-methyl-8-quinolinolate)-4-(phenylphenolinate)aluminum, triarylamine derivatives, styrylamine derivatives, stilbene derivatives, coumarin derivatives, pyrane derivatives, oxazone derivatives, benzothiazole derivatives, benzoxazole derivatives, benzimidazole derivatives, pyrazine derivatives, cinnamate derivatives, diketo-pyrrolo-pyrrole derivatives, acrylidone derivatives, quinacrylidone derivatives and fluoranthene derivatives.

The hole-injecting/transporting layer is a layer which helps injection of holes to the emitting layer, and transports the holes to the emission range. It has a large hole mobility, and normally has a small ionization energy of 5.6 eV or less. As the material for such hole-injecting/transporting layer, a material which transports holes to the emitting layer at a lower electric field is preferable. Further, it is preferred that the mobility of holes be at least 10⁻⁴cm²/V·sec when applying an electric field of 10⁴to 10⁶V/cm.

As mentioned above, the polymer of the invention is particularly preferably used in the hole-injecting/transporting layer.

If the polymer of the invention is used in the hole-transporting region, the hole-injecting/transporting layer may be formed by using the hole-transporting material of the invention alone or in a mixture with other materials.

As the other material for forming the hole-injecting/transporting layer in a mixture with the polymer of the invention, any materials which have the above preferable properties can be used as without particular limitation. The material for forming the hole-injecting/transporting layer can be arbitrarily selected from materials which have been widely used as a material transporting carriers of holes in photoconductive materials and known materials used in a hole-injecting/transporting layer of organic EL devices. In the invention, a material which has a hole-transporting capability and can be used in the hole-transporting region is referred to as the hole-transporting material.

Specific examples of other materials than the polymer of the invention used in the hole-injecting/transporting layer include, though not limited thereto, a phthalocyanine derivative, a naphthalocyanine derivative, a porphyrin derivative, oxazole, oxadiazole, triazole, imidazole, imidazolone, imidazolethione, pyrazoline, pyrazolone, tetrahydroimidazole, oxazole, oxadiazole, hydrazone, acylhydrazone, polyarylalkane, stilbene, butadiene, benzidine-type triphenylamine, styrylamine-type triphenylamine, diamine-type triphenylamine, derivatives thereof, polymer materials such as polyvinyl carbazole, polysilane, conductive polymers (polyaniline and polythiophene) and a polymer of polymerizable monomers in which the above-mentioned monoamine-, diamine-, and triamine-based aromatic compounds are substituted by the group comprising a polymerizable functional group.

Of the hole-injecting materials which can be used in the organic EL device of the invention, a still further effective hole-injecting material is an aromatic tertiary amine derivative and a phthalocyanine derivative.

Examples of the aromatic tertiary amine derivatives include, though not limited thereto, triphenylamine, tritolylamine, tolyldiphenylamine, N,N′-diphenyl-N,N′-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine, N,N,N′,N′-(4-methylphenyl)-1,1′-phenyl-4,4′-diamine, N,N,N′,N′-(4-methylphenyl)-1,1′-biphenyl-4,4′-diamine, N,N′-diphenyl-N,N′-dinaphthyl-1,1′-biphenyl-4,4′-diamine, N,N′-(methylphenyl)-N,N′-(4-n-butylphenyl)-phenathrene-9,10-diamine, N,N-bis(4-di-4-tolylaminophenyl)-4-phenyl-cychlohexane or an oligomer or a polymer having these aromatic tertiary amine skeleton.

Examples of the phthalocyanine (Pc) derivative include, though not limited thereto, phthalocyanine derivatives and naphthalocyanine derivatives such as H₂Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc, ClInPc, ClSnPc, Cl₂SiPc, (HO)AlPc, (HO)GaPc, VOPc, TiOPc, MoOPc and GaPc-O—GaPc. Further, it is preferred that the organic EL device of the invention comprise, between the emitting layer and the anode, a layer, a hole-transporting layer or a hole-injecting layer, for example, which contains the aromatic tertiary amine derivative and/or the phthalocyanine derivative as mentioned above.

Next, an explanation is made on the electron-injecting/transporting layer. The electron-injecting/transporting layer is a layer which helps injection of electrons to the emitting layer and transports the electrons to the emission region, and has a large electron mobility. The adhesion-improving layer is one of the electron-injecting layers which is formed of a material which has particularly good adhesion to the cathode.

Further, it is known that, in an organic EL device, since emitted light is reflected by an electrode (the cathode, in this case), light which is directly outcoupled from the anode interferes with light outcoupled after being reflected by the electrode. In order to utilize this interference effect efficiently, the film thickness of the electron-transporting layer is appropriately selected in a range of several nm to several μm. If the thickness is particularly large, in order to avoid an increase in voltage, it is preferred that the electron mobility be at least 10⁻⁵cm²/Vs or more when an electric field of 10⁴to 10⁶V/cm is applied.

Specific examples of the material used in the electron-injecting layer include, though not limited thereto, fluorenone, anthraquinodimethane, diphenoquinone, thiopyrane dioxide, oxazole, oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane, anthrone, and derivatives thereof. Further, sensitization is possible by adding an electron-accepting material to a hole-injecting material and an electron-donating material to an electron-injecting material.

In the organic EL device of the invention, a still further effective electron-injecting material is a metal complex compound and a nitrogen-containing five-membered derivative.

Examples of the metal complex compound include, though not limited thereto, 8-hydroxyquinolinate lithium, bis(8-hydroxyquinolinate)zinc, bis(8-hydroxyquinolinolate)copper, bis(8-hydroxyquinolinate)manganese, tris(8-hydroxyquinolinate)aluminum, tris(2-methyl-8-hydroxyquinolinate)aluminum, tris(8-hydroxyquinolinate)gallium, bis(10-hydroxybenzo[h]quinolinate)beryllium, bis(10-hydroxybenzo[h]quinolinate)zinc, bis(2-methyl-8-quinolinate)chlorogallium, bis(2-methyl-8-quinolinate)(o-cresolate)gallium, bis(2-methyl-8-quinolinate)(1-naphtholate)aluminum and bis(2-methyl-8-quinolinate)(2-naphtholate)gallium.

As the nitrogen-containing five-membered derivative, oxazole, thiazole, oxadiazole, thiadiazole and triazole derivatives are preferable. Specific examples include, though not limited thereto, 2,5-bis(1-phenyl)-1,3,4-oxazole, dimethyl POPOP, 2,5-bis(1-phenyl)-1,3,4-thiazole, 2,5-bis(1-phenyl)-1,3,4-oxadiazole, 2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-oxadiazole, 2,5-bis(1-naphthyl)-1,3,4-oxadiazole, 1,4-bis[2-(5-phenyloxadiazolyl)]benzene, 1,4-bis[2-(5-phenyl oxadiazolyl)-4-tert-butylbenzene], 2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-thiadiazole, 2,5-bis(1-naphthyl)-1,3,4-thiadiazole, 1,4-bis[2-(5-phenylthiadiazolyl)]benzene, 2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-triazole, 2,5-bis(1-naphthyl)-1,3,4-triazole and 1,4-bis[2-(5-phenyltriazoly)]benzene.

In the organic EL device of the invention, the emitting layer may contain, in addition to the polymer of the invention, at least one of an emitting material, a doping material, a hole-injecting material and an electron-injecting material in the same layer. In order to improve stability to temperature, humidity, atmosphere or the like of the organic EL device of the invention, it is possible to provide a protective layer on the surface of the device, or to protect the entire device with silicone oil, a resin or the like.

In the organic EL device of the invention, in order to allow it to emit light efficiently, it is preferred that at least one of the surfaces be fully transparent in the emission wavelength region of the device. In addition, it is preferred that the substrate also be transparent. The transparent electrode is set such that predetermined transparency can be ensured by a method such as deposition or sputtering by using the above-mentioned conductive materials. It is preferred that the electrode on the emitting surface have a light transmittance of 10% or more. Although no specific restrictions are imposed on the substrate as long as it has mechanical and thermal strength and transparency, a glass substrate and a transparent resin film can be given. Examples of the transparent resin film include polyethylene, an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, polypropylene, polystyrene, polymethylmethacrylate, polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyetheretherketone, polysulfone, polyethersulfone, a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, polyvinyl fluoride, a tetrafluoroethylene-ethylene copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, polyester, polycarbonate, polyurethane, polyimide, polyether imide, polyimide and polypropylene.

Each layer of the organic EL device of the invention can be formed by a known method such as a dry film-forming method such as vacuum vapor deposition, sputtering, plasma, and ion plating and a wet film-forming method such as spin coating, dipping and flow coating. Although there are no particular restrictions on the film thickness of each layer, it is required to set it to a suitable film thickness. If the film thickness is too large, a large voltage is required to be applied in order to obtain a certain optical output, resulting in poor efficiency. If the film thickness is too small, pinholes or the like are generated, and hence, a sufficient luminance cannot be obtained even if an electric field is applied. The film thickness is normally in the range of 5 nm to 10 μm, with the range of 10 nm to 0.2 μm being further preferable.

As the method for forming a layer containing the polymer of the invention (the hole-injecting/transporting layer, in particular), forming a solution of the polymer into a film can be mentioned, for example. As the film-forming method, the spin coating method, the casting method, the microphotogravure coating method, the photogravure coating method, the bar coating method, the roll coating method, the slit coating method, the wire bar coating method, the dip coating method, the spray coating method, the screen printing method, the flexo printing method, the offset printing method, the ink-jet method, the nozzle printing method or the like can be mentioned. When a pattern is formed, the screen printing method, the flexo printing method, the offset printing method and the ink jet printing method are preferable. Film formation by these methods can be conducted under conditions which are well known by a person in the art, and hence the details thereof are omitted.

After the film formation, the film is heated (200° C. at most) under vacuum and dried to remove the solvent. No polymerization reaction by light or heating at high temperatures (200° C. or higher) is necessary. Therefore, deterioration of performance by light or heating at high temperatures can be suppressed.

It suffices that the solution for film formation contain at least one kind of the polymer of the invention. In addition to the above-mentioned materials, it may contain a hole-transporting material, an electron-transporting material, an emitting material, an acceptor material, a solvent and an additive such as a stabilizer. The content of the polymer in the solution for film formation is preferably 20 to 100 wt %, more preferably 40 to 100 wt % relative to the total weight of the composition excluding the solvent. The amount ratio of the solvent is preferably 1 to 99.9 wt % relative to the solution for film formation, with 80 to 99 wt % being more preferable.

The solution for film formation may contain an additive for controlling the viscosity and/or the surface tension, for example, a thickener (a high molecular compound, a poor solvent for the high-molecular compound of the invention, or the like), a viscosity reducing agent (a low-molecular compound or the like), a surfactant or the like. In order to improve storage stability, an antioxidant which does not affect the performance of the organic EL device, such as a phenol-based antioxidant and a phosphor-based antioxidant may be contained.

Examples of the usable high-molecular compounds include insulative resins such as polystyrene, polycarbonate, polyarylate, polyester, polyamide, polyurethane, polysulfone, polymethylmethacrylate, polymethylacrylate and cellulose, copolymers thereof, photoconductive resins such as poly-N-vinylcarbozole and polysilane and conductive resins such as polythiophene and polypyrrole.

Example of the solvent for the solution for film formation include chlorine-based solvents such as chloroform, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene and o-dichlorobenzene; ether-based solvents such as tetrahydrofuran, dioxane, dioxolane, and anisole; aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon-based solvents such as cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane; ketone-based solvents such as acetone, methylethylketone, cyclohexanone, benzophenone and acetophenone; ester-based solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, methyl benzoate and phenyl acetate; polyvalent alcohols such as ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethoxy ethane, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, 1,2-hexanediol and derivatives thereof; alcohol-based solvents such as methanol, ethanol, propanol, isopropanol and cyclohexanol; sulfoxide-based solvents such as dimethylsulfoxide; and amide-based solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide can be mentioned. These organic solvents may be used alone or in combination of two or more. Of these, in respect of solubility, homogeneity of a coating film, viscosity properties or the like, aromatic hydrocarbon-based solvents, ether-based solvents, aliphatic hydrocarbon-based solvents, ester-based solvents and ketone-based solvents are preferable. Toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, n-propylbenzene, isopropyl benzene, n-butyl benzene, isobutylbenzene, 5-butylbenzene, n-hexylbenzene, cyclohexylbenzene, 1-methylnaphthalene, tetralin, 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, anisole, ethoxybenzene, cyclohexane, bicyclohexyl, cyclohexeny cyclohexanone, n-heptylcyclohexane, n-hexylcyclohexane, decaline, methyl benzoate, cyclohexanone, 2-propylcyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-octanone, 2-nonanone, 2-decanone, dicyclohexylketone, acetophenone and benzophenone are more preferable.

The organic EL device can be fabricated by forming an anode, optionally a hole-injecting/transporting layer, an emitting layer, and optionally an electron-injecting/transporting layer, and further forming a cathode using the materials and methods exemplified above. The organic EL device can be fabricated in the order reverse to the above, i.e., the order from a cathode to an anode.

EXAMPLES

The invention will be explained below in detail with reference to Examples, which should not be construed as limiting the scope of the invention.

(Synthesis of Various Monomers)

Synthesis of Intermediate A

Intermediate A was synthesized according to the following scheme.

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In an argon atmosphere, to a 500 mL-three neck flask provided with a condenser tube, 2.4 g (40 mmol) of acetoamide, 7.5 g (48 mmol) of bromobenzene, 6.2 g (32 mmol) of copper iodide, 4.3 g (48 mmol) of N,N-dimethylethylenediamine, 22.4 g (160 mol) of potassium carbonate and 200 mL of dehydrated xylene were added. The resultant was stirred with heating at 100° C. overnight. After the reaction was completed, the reaction solution was filtered, and filtrates obtained were washed with water. The xylene phase was concentrated, and crystals deposited were isolated, and washed with 100 mL of toluene and 200 mL of methanol, whereby 2.7 g of pale yellow powder was obtained (Intermediate a, yield 50%).

In an argon atmosphere, to a 300 mL-three neck flask provided with a condenser tube, 2.7 g (20 mmol) of intermediate (a), 6.3 g (24 mmol) of 4-anisolyl-1-bromobenzene, 3.1 g (16 mmol) of copper iodide, 2.1 g (24 mmol) of N,N-dimethylethylenediamine, 11.2 g (80 mol) of potassium carbonate and 100 mL of dehydrated xylene were added. The resultant was stirred with heating at 100° C. overnight. After the reaction was completed, the reaction solution was filtered, and the resultant was washed with water. The xylene phase was concentrated, crystals deposited were isolated, and purified by column chromatography by using toluene as an eluent, whereby 4.4 g of pale yellow powder was obtained (Intermediate b, yield 70%).

To a 300 mL-three neck flask provided with a condenser tube, 4.4 g (14 mmol) of intermediate (b), 5.6 g (100 mmol) of potassium hydroxide, 100 mL of ethanol and 100 mL of toluene were added. The resultant was stirred with heating at 80° C. overnight. After the reaction was completed, the toluene phase which had been washed with water was concentrated, crystals deposited were isolated, and washed with 100 mL of toluene and 100 mL of methanol, whereby 2.8 g of pale yellow powder was obtained (Intermediate c, yield 73%).

In an argon atmosphere, to a 300 mL-three neck flask provided with a condenser tube, 5.5 g (10 mmol) of 4-bromo-tris(p-biphenyl)amine, 2.8 g (10 mmol) of intermediate (c), 0.02 g (0.1 mmol) of palladium acetate, 0.1 g (0.5 mmol) of tri-t-butylphosphine, 0.7 g (7 mmol) of sodium t-butoxide and 100 mL of dry toluene were added. The resultant was stirred with heating at 100° C. overnight. After the reaction was completed, crystals deposited were filtered, and purified by column chromatography by using toluene as an eluent, whereby 6.0 g of pale yellow powder was obtained (Intermediate d, yield 80%).

Next, in an argon atmosphere, in a 300 mL-three neck flask, 6.0 g (8 mmol) of intermediate (d) was dissolved in 100 mL of dehydrated methylene chloride. After cooling the resulting solution at 10° C., a methylene chloride solution of 2.11 g (8.4 mmol) of boron tribromide was added dropwise, followed by stirring at room temperature for 4 hours. After the reaction liquid was treated with water, the methylene chloride phase was extracted and concentrated. Column chromatography was conducted by using toluene as an eluent, whereby 5.3 g of pale yellow powder was obtained (Intermediate e, yield 90%).

In an argon atmosphere, in a 300 mL-three neck flask, 3.7 g (5.0 mmol) of intermediate (e) and 1.0 g (10 mmol) of diisopropylamine were dissolved in 100 mL of dehydrated methylene chloride. After cooling the resulting solution at 0° C., a dehydrated methylene chloride solution of 3.1 g (11 mmol) of trifluoromethanesulfonic anhydride was added dropwise, followed by stirring at room temperature for 21 hours. Next, the reaction solution was neutralized in a 5% aqueous sodium carbonate solution, and the methylene chloride phase was extracted and concentrated. Column chromatography was conducted by using toluene as a solvent, whereby 3.8 g of pale yellow powder was obtained (Intermediate A, yield 88%).

Monomers (1) to (5) were synthesized according to the following synthesis scheme.

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Example 1

In an argon atmosphere, to a 100 mL-three neck flask provided with a condenser tube, 2.6 g (3 mmol) of intermediate (A), 0.4 g (3 mmol) of 4-vinylphenylboronic acid, 0.7 g (60 μmol) of tetrakis(triphenylphosphine)palladium (0), 1.0 g (9 mmol) of sodium carbonate and 50 mL of dry toluene were added. The resultant was stirred with heating at 80° C. for 24 hours. After the reaction was completed, crystals deposited were filtered out, and column chromatography was conducted by using a toluene solvent, whereby 2.0 g of pale yellow powder was obtained. The powder was confirmed to be an intended product (1) by NMR, MS or the like (yield 80%).

Example 2

In an argon atmosphere, to a 100 mL-three neck flask provided with a condenser tube, 2.6 g (3 mmol) of intermediate (A), 0.4 g (3 mmol) of 4-hydroxyphenylboronic acid, 0.7 g (60 μmol) of tetrakis(triphenylphosphine)palladium (0), 1.0 g (9 mmol) of sodium carbonate and 50 mL of dry toluene were added. The resultant was stirred with heating at 80° C. for 24 hours. After the reaction was completed, crystals deposited were filtered out, and column chromatography was conducted by using a toluene solvent, whereby pale yellow powder (phenol derivative) was obtained.

Subsequently, in an argon atmosphere, in a 100 mL-three neck flask, the above-obtained phenol derivative and 0.5 g (5 mmol) of triethylamine were dissolved in 50 mL of dehydrated toluene. After cooling the resulting solution at 0° C., a dehydrated toluene solution of 0.3 g (3 mmol) of methacrylic chloride was added dropwise, followed by stirring at room temperature for 10 hours. Deposited salts were filtered out, and the filtrate was concentrated. Column chromatography was conducted by using toluene as a solvent, whereby 1.8 g of pale yellow powder was obtained. The powder was confirmed to be an intended product (2) by NMR, MS or the like (yield 67%).

Example 3

In an argon atmosphere, to a 100 mL-three neck flask provided with a condenser tube, 2.6 g (3 mmol) of intermediate (A), 0.6 g (3 mmol) of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline, 0.7 g (60 μmol) of tetrakistriphenylphosphine palladium (0), 1.0 g (9 mmol) of sodium carbonate and 50 mL of dry toluene were added. The resultant was stirred with heating at 80° C. for 24 hours. After the completion of the reaction, crystals deposited were filtered out. Column chromatography was conducted by using a toluene solvent, whereby pale yellow powder was obtained (aniline derivative).

Subsequently, in an argon atmosphere, in a 100 mL-three neck flask, the above-obtained aniline derivative and 0.5 g (5 mmol) of triethylamine were dissolved in 50 mL of dehydrated toluene. After cooling the resulting solution at 0° C., a dehydrated toluene solution of 0.3 g (3 mmol) of methacrylic chloride was added dropwise, followed by stirring at room temperature for 10 hours. Deposited salts were filtered out, and the filtrate was concentrated. Column chromatography was conducted by using toluene as a solvent, whereby 1.6 g of pale yellow powder was obtained. The powder was confirmed to be an intended product (3) by NMR, MS or the like (yield 60%).

Example 4
Diels-Alder Reaction
Reaction of the Product Obtained in Example 1 and Cyclopentadiene

All of the reactions were conducted in an argon atmosphere. To a 200 mL-three neck flask provided with a condenser tube, 1.18 g (molecular weight: 819.04, 1.44 mmol) of compound (1) synthesized in the same manner as in Example 1 and 144 mL of a solvent toluene were added, and the resultant was stirred with heating to allow the compound (1) to be completely dissolved in the toluene. This solution was allowed to stand to room temperature. Subsequently, 10 g (molecular weight: 66.10, 150 mmol) of cyclopentadiene which had been distilled immediately before use and a small amount of p-toluenesulfonic acid were added, and the resultant was allowed to react at room temperature for 2 hours. The resultant was then allowed to further react at 75° C. for 5 hours. This reaction liquid was poured to a large amount of hexane (about 1000 mL), and solid components generated were filtered out. The solids components were purified by means of column chromatography by using a methylene chloride/hexane mixed solvent as an eluent, whereby 0.80 g (molecular weight: 885.14, 0.90 mmol) of pale yellow powder (compound (4), yield 63%) was obtained. The powder was confirmed to be an intended product by NMR, MS or the like.

Example 5

In an argon atmosphere, to a 100 mL-three neck flask provided with a condenser, 2.6 g (3 mmol) of intermediate (A), 0.4 g (3 mmol) of 4-hydroxyphenylboronic acid, 0.7 g (60 μmol) of tetrakistriphenylphosphine palladium (0), 1.0 g (9 mmol) of sodium carbonate and 50 mL of dry toluene were added. The resultant was stirred with heating at 80° C. for 24 hours. After the completion of the reaction, crystals deposited were filtered out, and column chromatography was conducted by using a toluene solvent, whereby pale yellow powder was obtained (phenol derivative).

Subsequently, in an argon atmosphere, in a 100 mL-three neck flask, the phenol derivative and 0.6 g (6 mmol) of diisopropylamine were dissolved in 50 mL of dehydrated methylene chloride. After cooling at 0° C., a dehydrated methylene chloride solution of 1.6 g (6 mmol) of trifluoromethanesulfonic anhydride was added dropwise, and the resultant was stirred at room temperature for 21 hours. Next, the reaction solution was neutralized in a 5% aqueous sodium carbonate solution, and the methylene chloride phase was extracted and concentrated. Column chromatography was conducted by using toluene as a solvent, whereby 2.3 g of pale yellow powder was obtained (Intermediate f, yield 80%).

In an argon atmosphere, in a 100 mL-three neck flask, 2.3 g (molecular weight: 941.07, 0.90 mmol) of the above-obtained intermediate f was dissolved in 50 mL of N,N-dimethylformamide (DMF). To the resulting solution, 0.12 g (molecular weight: 98.22, 1.22 mmol) of trimethylsilylacetylene, 3.5 mg (molecular weight: 383.57, 0.0091 mmol) of bis(benzonitrile)palladium(II) chloride complex, 1.7 mg of copper iodide (molecular weight: 190.45, 0.089 mmol), 0.20 g of triethylamine (molecular weight: 101.19, 2.0 mmol) and 1.5 mg (molecular weight: 202.32, 0.0074 mmol) of tri-tert-butylphosphine were added. The resultant was stirred with heating at 80° C. for 10 hours. A large amount of ethyl acetate was added to the reaction solution and the resultant was filtered through celite to allow ethyl acetate and DMF to be distilled off under reduce pressure, whereby a crude product of intermediate (g) was obtained.

Subsequently, in a 100 mL-three neck flask, the crude product of intermediate (g) was dissolved in 100 mL of methylene chloride. To the resulting solution, 0.26 mg (molecular weight: 261.46+18n, about 1.0 mmol) of TBAF (Tetra-n-butylammonium fluoride) was added, and the resultant was allowed to react at room temperature for 5 hours. The methylene chloride was distilled off under reduced pressure from this reaction liquid. The reaction liquid was purified by column chromatography by using a methylene chloride/hexane mixed solvent as an eluent, whereby 0.25 g (molecular weight: 817.03, 0.31 mmol) of an intended compound (compound (5), yield 34%) was obtained. The compound was confirmed to be the intended product by NMR, MS or the like.

Example 6

An intermediate was synthesized in the same manner as in the synthesis of intermediate (a), except that 4-bromo-1-phenylbenzene was used instead of bromobenzene. Further, an intended product (6) was obtained in the same manner as in Example 1, except that the above-obtained intermediate was used instead of intermediate A. The structure of the intended product was shown in Table 1. The same applies to the following examples.

Example 7

An intermediate was synthesized in the same manner as in the synthesis of intermediate (a), except that 4-bromo-p-terphenyl was used instead of bromobenzene, and in the synthesis of intermediate (b), 4-methoxy-1-bromobenzene was used instead of 4-anisolyl-1-bromobenzene. Further, an intended product (7) was obtained in the same manner as in Example 1, except that the above-obtained intermediate was used instead of intermediate A and vinyl magnesium bromide was used instead of 4-hydroxyphenylboronic acid.

Synthesis of Intermediate B

Intermediate B was synthesized according to the following scheme, with reference to the synthesis method of intermediate A.

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(Me is a methyl group)

Synthesis of Intermediate C

Intermediate C was synthesized according to the following scheme, with reference to the synthesis method of intermediate A.

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(Me is a Methyl Group)
Example 8

An intended product (8) was obtained in the same manner as in Example 1, except that intermediate B was used instead of intermediate A.

Example 9

An intended product (9) was obtained in the same manner as in Example 2, except that intermediate B was used instead of intermediate A.

Example 10

An intended product (10) was obtained in the same manner as in Example 3, except that intermediate B was used instead of intermediate A.

Example 11

An intended product (11) was obtained in the same manner as in Example 4, except that intermediate B was used instead of intermediate A.

Example 12

An intended product (12) was obtained in the same manner as in Example 5, except that intermediate B was used instead of intermediate A.

Example 13

An intended product (13) was obtained in the same manner as in Example 1, except that intermediate C was used instead of intermediate A.

Example 14

An intended product (14) was obtained in the same manner as in Example 2, except that intermediate C was used instead of intermediate A.

Example 15

An intended product (15) was obtained in the same manner as in Example 3, except that intermediate C was used instead of intermediate A.

Example 16

An intended product (16) was obtained in the same manner as in Example 4, except that intermediate C was used instead of intermediate A.

Example 17

An intermediate was synthesized in the same manner as in the synthesis of intermediate (a), except that the following compound was used instead of bromobenzene, and an intended product (17) was obtained in the same manner as in Example 1, except that the above-obtained intermediate was used instead of intermediate A.

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Example 18

An intermediate was synthesized in the same manner as in the synthesis of intermediate (a), except that the following compound was used instead of bromobenzene, and an intended product (18) was obtained in the same manner as in Example 1, except that the above-obtained intermediate was used instead of intermediate A.

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Example 19

An intermediate was synthesized in the same manner as in the synthesis of intermediate (a), except that the following compound was used instead of bromobenzene, and an intended product (19) was obtained in the same manner as in Example 1, except that the above-obtained intermediate was used instead of intermediate A.

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Example 20

An intermediate was synthesized in the same manner as in the synthesis of intermediate (a), except that the following compound was used instead of bromobenzene, and an intended product (20) was obtained in the same manner as in Example 1, except that the above-obtained intermediate was used instead of intermediate A.

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Example 21

An intermediate was synthesized in the same manner as in the synthesis of intermediate (a), except that the following compound was used instead of bromobenzene, and an intended product (21) was obtained in the same manner as in Example 1, except that the above-obtained intermediate was used instead of intermediate A.

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(Synthesis of Polymer)
Example 22
Cationic Polymerization
(1) Preparation of a Trifluoromethanesulfonic Acid Solution

In a nitrogen stream, commercially-available trifluoromethanesulfonic acid (25 g, 0.167 mol, molecular weight: 150.08, specific gravity: 1.70) was added to dehydrated methylene chloride, and the concentration was adjusted to 1.0 M (the total amount of the solution: 167 mL). Trifluoromethanesulfonic acid was not mixed completely homogenously with methylene chloride. Therefore, the resulting solution was sufficiently stirred to allow the trifluoromethanesulfonic acid to be suspended in the solution, and the resulting suspension was used in the subsequent reaction.

(2) Polymerization of Compound (1) of Example 1 (Cationic Polymerization)

A 500 mL-three neck flask provided with a reflux tube was fully replaced by nitrogen. In a nitrogen stream, the flask was charged with the monomer compound (1) obtained in Example 1 (1.18 g, 1.44 mmol) and dehydrated methylene chloride (200 mL), and the resultant was stirred under reflux for 1 hour until the monomer compound was completely dissolved. After cooling to room temperature, 4.32 mL (4.32 mmol) of the suspension of trifluoromethanesulfonic acid prepared in (1) above was added. The solution was stirred at room temperature for 4 hours, whereby a polymerization reaction was conducted.

(3) Post Treatment after the Reaction

The reaction liquid was poured to a large amount of methanol (800 mL) with stirring to allow solids (polymer) to be deposited. The solids were separated by filtration. Subsequently, the solids were dissolved in toluene (100 mL) at room temperature, and the resulting solution was poured to a large amount of methanol (800 mL) with stirring, while being filtered by means of filter paper, whereby the solids (polymer) were deposited. Further, methanol was separated by filtration, followed by sufficient drying, thereby to obtain 0.82 g (yield 70%) of the polymer. The polymer obtained had a number average molecular weight of 7000.

Example 23
Radical Polymerization

A 500 mL-three neck flask provided with a reflux tube was fully replaced by nitrogen. In a nitrogen stream, the flask was charged with the monomer compound (2) obtained in Example 2 (1.22 g, 1.44 mmol) and dehydrated methylene chloride (200 mL), and the resultant was stirred under reflux for 1 hour until the monomer compound was completely dissolved. The resultant was cooled to room temperature. Then, a solution obtained by dissolving 20 mg of benzoyl peroxide (BPO) as a radical polymerization initiator in 15 mL of dehydrated methylene chloride was added at room temperature. Subsequently, a polymerization reaction was conducted at 70° C. for 48 hours in nitrogen.

After the completion of the reaction, re-precipitation was conducted three times by using toluene as a good solvent and methanol as a poor solvent, whereby 0.90 g of a polymer was obtained. The resulting polymer had a number average molecular weight of 12,000.

Examples 26, 27, 29, 31, 32 and 33

In each example, a polymer was synthesized in the same manner as in Example 22 (cationic polymerization) using the monomer obtained in Examples 7, 8, 13, 17, 19 and 21, respectively.

Examples 24, 25, 28 and 30

In each example, a polymer was synthesized in the same manner as in example 23 (radical polymerization) using the monomer obtained in Examples 3, 6, 9 and 14, respectively.

The above-mentioned monomers and polymers obtained therefrom and the polymerization method are summarized in Table 1.

TABLE 1

Device

Poly-

fabrication

Mono-
mer
Poly-
and

Exam-

mer
exam-
merization
evaluation

ples
Monomer
No.
ples
method
examples

1

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(1)
22
Cationic
34

2

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(2)
23
Radical
35

3

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(3)
24
Radical
36

4

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(4)
—
—
—

5

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(5)
—
—
—

6

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(6)
25
Radical
37

7

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(7)
26
Cationic
38

8

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(8)
27
Cationic
39

9

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(9)
28
Radical
40

10

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(10)
—
—
—

11

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(11)
—
—
—

12

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(12)
—
—
—

13

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(13)
29
Cationic
41

14

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(14)
30
Radical
42

15

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(15)
—
—
—

16

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(16)
—
—
—

17

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(17)
31
Cationic
43

18

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(18)
—
—
—

19

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(19)
32
Cationic
44

20

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(20)
—
—
—

21

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(21)
33
Cationic
45

Example 34
Fabrication and Evaluation of Organic EL Device

A glass substrate (GEOMATEC CO., LTD.) of 25 mm×75 mm×1.1 mm thick with an ITO transparent electrode was subjected to ultrasonic cleaning with isopropyl alcohol for 5 minutes, and cleaned with ultraviolet rays and ozone for 30 minutes.

On the cleaned glass substrate provided with a transparent electrode, a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid (PEDOT:PSS) which is used in the hole-injecting layer was formed into a 10 nm-thick film by the spin coating method (PSS is an acceptor).

Subsequently, as a hole-transporting polymer, the polymer obtained in Example 22 was used, a 1,4-dioxane solution (1.0 wt %) thereof was prepared, and the solution was formed into a 40 nm-thick film by the spin coating method, followed by drying at 100° C. for 30 minutes.

Subsequently, the following compound EM1 was deposited to form a 40 nm-thick emitting layer. Simultaneously, as the material for the emitting layer, the following amine compound D1 having a styryl group was deposited such that the weight ratio of EM1 and D1 became 40:2.

On this film, the following Alq was formed into a 10 nm-thick film. This layer functions as an electron-injecting layer. Subsequently, Li as a reducing dopant (Li source: manufactured by SAES Getters Co., Ltd.) and Alq were co-deposited, thereby to form an Alq:Li film (film thickness: 10 nm). Metal aluminum was deposited on this Alq:Li film to form a metal cathode, sealed with glass in nitrogen, whereby an organic EL device was fabricated.

Electric current was passed through the device to evaluate the performance thereof. The organic EL device emitted blue light, had a luminous efficiency of 6.9 cd/A and a luminous half life at room temperature LT50 of 3300 hr@1000 cd/m².

This device was driven in an oven of 60° C. The luminous half life LT50 was 1300 hr@1000 cd/m².

Therefore, the ratio of the luminous half life at 60° C. to the luminous half life at room temperature was 0.39.

As is apparent from the above, the device of this example was improved in luminous efficiency and life, and the life thereof was lowered only slightly even when it was driven at high temperatures. The results of device evaluation are shown in Table 2.

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Example 35

An organic EL device was fabricated in the same manner as in Example 34, except that the polymer obtained in Example 23 was used as the hole-transporting polymer. Electric current was passed through the device to evaluate the performance thereof. The organic EL device emitted blue light, had a luminous efficiency of 6.5 cd/A and a luminous half life at room temperature LT50 of 3000 hr@1000 cd/m².

This device was driven in an oven of 60° C. The luminous half life at room temperature LT50 was 1100 hr@1000 cd/m².

Therefore, the ratio of the luminous half life at 60° C. to the luminous half life at room temperature was 0.37.

Examples 36 to 45

An organic EL device was fabricated in the same manner as in Example 34, except that the polymers shown in Table 2 were used as the hole-transporting polymers. The results of device evaluation are shown in Table 2.

Example 46
Device Fabrication and Evaluation

An organic EL device was fabricated in the same manner as in Example 34, except that the following arylamine compound D2 was used instead of the amine compound D1 having a styryl group as the material for the emitting layer. The organic EL device was evaluated in the same manner as in Example 34. The results are shown in Table 2.

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(Me is a Methyl Group)
Comparative Example 1
TPD Polymer

An organic EL device was fabricated and evaluated in the same manner as in Example 34, except that the polymer having the following structural unit which had been synthesized based on the production example given in JP-A-H08-269133 was used as the hole-transporting polymer.

Electric current was passed through the device to evaluate the performance thereof. The organic EL device emitted blue light, had a luminous efficiency of 3.0 cd/A and a luminous half life LT50 at room temperature of 700 hr@1000 cd/m².

This device was driven in an oven of 60° C. The luminous half life LT50 was 150 hr@1000 cd/m².

Therefore, the ratio of the luminous half life at 60° C. to the luminous half life at room temperature was 0.21

The device of this Comparative Example was inferior to those of Examples in luminous efficiency and life. In addition, this device suffered a significant lowering in life when it was driven at high temperatures. (see Table 2)

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Comparative Example 2

An organic EL device was fabricated and evaluated in the same manner as in Comparative Example 1, except that the dopant was changed to D2 as the material for the emitting layer.

Electric current was passed through the device to evaluate the performance thereof. The organic EL device emitted blue light, had a luminous efficiency of 3.5 cd/A and a luminous half life LT50 at room temperature of 800 hr@1000 cd/m².

This device was driven in an oven of 60° C. The luminous half life at room temperature LT50 was 200 hr@1000 cd/m².

Therefore, the ratio of the luminous half life at 60° C. to the luminous half life at room temperature was 0.25.

TABLE 2

Half life

Hole-
Host in
Dopant in

Luminous
Luminance half life
Luminance half
ratio: 60° C./

transporting
emitting
emitting
Emission
efficiency
at room temperature
life at 60° C.
Room

polymer
layer
layer
color
(cd/A)
(hr@1000 cd/m²)
(hr@1000 cd/m²)
temperature

Example 34
Example 22
EM1
D1
Blue
6.9
3,300
1,300
0.39

Example 35
Example 23
EM1
D1
Blue
6.5
3,000
1,100
0.37

Example 36
Example 24
EM1
D1
Blue
6.7
3,200
1,200
0.38

Example 37
Example 25
EM1
D1
Blue
6.8
3,000
1,200
0.40

Example 38
Example 26
EM1
D1
Blue
6.8
3,100
1,200
0.39

Example 39
Example 27
EM1
D1
Blue
6.8
2,200
700
0.32

Example 40
Example 28
EM1
D1
Blue
6.5
2,100
700
0.33

Example 41
Example 29
EM1
D1
Blue
6.8
2,800
1,000
0.36

Example 42
Example 30
EM1
D1
Blue
6.5
2,800
1,000
0.36

Example 43
Example 31
EM1
D1
Blue
6.9
3,500
1,600
0.46

Example 44
Example 32
EM1
D1
Blue
6.9
3,300
1,500
0.45

Example 45
Example 33
EM1
D1
Blue
6.7
3,000
1,400
0.47

Example 46
Example 22
EM1
D2
Blue
7.0
3,400
1,300
0.38

Com. Ex. 1
TPD polymer
EM1
D1
Blue
3.0
700
150
0.21

Com. Ex. 2
TPD polymer
EM1
D2
Blue
3.5
800
200
0.25

INDUSTRIAL APPLICABILITY

According to the invention, it is possible to provide a novel polymerizable monomer having a polymerizable functional group, as well as a polymer having it as a repeating unit, which is effective as the hole-injecting/transporting material of an organic device, in particular, an organic EL device. The invention can provide an organic EL device which is suited to practical use since it is improved in device properties such as life and luminous efficiency and suffers only a slight degree of deterioration even when subjected to high-temperature driving which is especially practical in applications such as a display and an illuminator.

In addition, since a homogenous hole-injecting/transporting layer can be formed by the coating method, the organic EL device of the invention is effective for a reduction in cost or an increase in screen size in applications of a display or illumination.

Although only some exemplary embodiments and/or examples of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments and/or examples without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention.

The documents described in the specification are incorporated herein by reference in its entirety.

NOVEL POLYMERIZABLE MONOMER AND POLYMER OF THE POLYMERIZABLE MONOMER, AND MATERIAL FOR ORGANIC DEVICE, HOLE INJECTION/TRANSPORT MATERIAL AND ORGANIC ELECTROLUMINESCENT ELEMENT EACH COMPRISING THE POLYMER

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