JP2005097589A - Phosphorescent polymer compound and organic light emitting device using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phosphorescent polymer material achieving high light emitting efficiency at a low voltage, which can cope with area enlargement and mass production, and an organic light emitting device using this. <P>SOLUTION: This phosphorescent polymer compound is characterized by comprising a hole-carrying monomer unit having a triphenylamine structure expressed by formula (1) and a phosphorescent monomer unit. The organic light emitting device employs the compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a phosphorescent polymer compound, a flat display panel, and an organic light emitting device (OLED) for a backlight used therein.

  Organic light-emitting devices have been developed since 1987 when Kodak's CW Tang et al. Showed high-luminance emission (Non-patent Document 1: Appl. Phys. Lett., 51, 913, 1987). The device structure has been improved rapidly, and recently it has been put into practical use from displays for car audio and mobile phones. In order to further expand the applications of this organic EL (electroluminescent) element, development of materials for improving luminous efficiency and durability, development of full-color display, and the like are being actively conducted. In particular, when considering expansion to medium-sized panels, large-sized panels, or lighting applications, it is necessary to further increase the luminance by improving the light emission efficiency. However, light emission from the excited singlet state, that is, fluorescence is used in the present light emitting material, and the exciton generation ratio of the excited singlet state and the excited triplet state in electrical excitation is 1: 3. For this reason, the upper limit of the internal quantum efficiency of light emission in the organic EL has been 25% (corresponding to an external quantum efficiency of 5% when the external extraction efficiency is 20%).

  On the other hand, MA Baldo et al. Use an iridium complex that emits phosphorescence from an excited triplet state at room temperature to achieve an external quantum efficiency of 7.5% (assuming an external extraction efficiency of 20%, the internal quantum efficiency is equivalent to 37.5%) It was shown that it was possible to exceed the value of 5% of the external quantum efficiency that has been conventionally set as the upper limit. Furthermore, high efficiency of nearly 20% has been achieved by devising the host material and device configuration (Non-patent Document 2: Appl. Phys. Lett., 90, 5048, 2001). It is attracting attention as a method. Specifically, 4,4′-N, N′-dicarbazole biphenyl (CBP) or the like is used as a host material (Patent Document 1: International Publication No. 01/45512 pamphlet).

  However, this phosphorescent iridium complex is a low-molecular compound and is formed by a vacuum deposition method. This vacuum deposition method is a film forming method that is currently widely used for low molecular weight light emitting materials. However, it requires vacuum equipment, and the organic thin film is formed with a uniform thickness as the area increases. In addition, it is difficult to form a high-definition pattern, and is not necessarily a method suitable for mass production of large-area panels.

  On the other hand, as an element manufacturing method suitable for an increase in area and mass production, a method of forming a film of a polymer light emitting material by a spin coating method, an ink jet method, a printing method, or the like has been developed. Although these methods are widely used in fluorescent light-emitting polymer materials, phosphorescent light-emitting polymer materials have also been developed, and phosphorescent light-emitting materials having a phosphorescent light-emitting site and a carrier transporting site in the side chain are being developed. It has been reported that an external quantum efficiency exceeding 5% can be obtained using a conductive polymer material (Non-patent Document 3: Proceedings of The 11th International Workshop on Inorganic and Organic Electroluminescence (EL2002), p.283-286, 2002). In this document, a vinyl carbazole structure is used for the hole transport site.

  However, the above-described phosphorescent polymer material still has an external quantum efficiency of only 6%, which slightly exceeds the limit of fluorescence emission of 5%. Is not obtained.

WO 01/45512 pamphlet Appl.Phys.Lett., 51, 913, 1987 Appl.Phys.Lett., 90, 5048, 2001 Proceedings of The 11th International Workshop on Inorganic and Organic Electroluminescence (EL2002), p.283-286, 2002

  To date, high-efficiency phosphorescent polymer materials suitable for large-area and mass-production have been developed. The organic light emitting element which has been obtained has not been obtained yet. In view of the above, an object of the present invention is to provide a phosphorescent polymer material capable of obtaining high luminous efficiency at a low voltage and suitable for large area and mass production, and an organic light emitting device using the same.

  The inventors of the present invention considered that the hole transport site used in the phosphorescent polymer material so far has a vinyl carbazole structure, so that the driving voltage is high and the power efficiency is low. As a result, the inventors have found that the use of a triphenylamine structure reduces the driving voltage and improves the external quantum efficiency, thereby completing the present invention.

（式中、Ｒ¹〜Ｒ²⁷はそれぞれ独立して、水素原子、ハロゲン原子、シアノ基、アミノ基、炭素数１〜６のアルキル基、または炭素数１〜６のアルコキシ基を表す。また、Ｒ¹〜Ｒ¹⁹のうち、同一のフェニル基の隣接する炭素原子にそれぞれ結合している基は、互いに結合して縮合環を形成してもよい。Ｒ²⁸は、水素原子、または炭素数１〜６のアルキル基を表す。Ｘは、単結合、酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）、−ＣＯ−、または炭素数１〜２０の２価の有機基（但し、有機基は酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）および−ＣＯ−からなる群より選択される原子、もしくは基によって置換されていてもよい。）を表す。ｐは０または１である。）と燐光発光性モノマー単位を含むことを特徴とする燐光発光性高分子化合物。
２．式（２）で示されるモノマー単位：

（式中、Ｒ²⁹〜Ｒ³⁴はそれぞれ独立して、水素原子、炭素数１〜６のアルキル基または炭素数１〜６のアルコキシ基を表す。Ｘは、単結合、酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）、−ＣＯ−、または炭素数１〜２０の２価の有機基（但し、有機基は酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）および−ＣＯ−からなる群より選択される原子、もしくは基によって置換されていてもよい。）を表す。ｐは０または１である。）と燐光発光性モノマー単位を含む前記１に記載の燐光発光性高分子化合物。
３．さらに電子輸送性モノマー単位を含む前記１または２に記載の燐光発光性高分子化合物。
４．電子輸送性のモノマー単位の電子輸送性部位が、オキサジアゾール誘導体、トリアゾール誘導体、トリアジン誘導体、ベンゾオキサゾール誘導体、イミダゾール誘導体、およびキノリノール誘導体金属錯体から選択される前記３に記載の燐光発光性高分子化合物。
５．前記燐光発光性モノマー単位が重合性基と燐光発光部位を含み、燐光発光部位が燐光発光性高分子の側鎖に含まれる前記１または２に記載の燐光発光性高分子化合物。
６．前記燐光発光性モノマー単位が遷移金属錯体を含む前記１または２に記載の燐光発光性高分子化合物。
７．陽極と陰極に挟まれた一または複数の高分子層を含む有機発光素子において、前記高分子層の少なくとも一層が前記１乃至６のいずれか１項に記載の燐光発光性高分子化合物を含む有機発光素子。
８．陽極が、ＵＶオゾン照射処理又は高周波プラズマ処理されている前記７に記載の有機発光素子。
９．高周波プラズマ処理が、有機物を含むガスによる処理である前記８に記載の有機発光素子。
１０．有機物を含むガスが、フルオロカーボン及び／またはメタンの少なくとも一種以上を含むガスである前記９に記載の有機発光素子。
１１．高周波プラズマ処理が、酸素及び／またはアルゴンの少なくとも一種以上を含むガスによる処理である前記８に記載の有機発光素子。 That is, the present invention relates to the following phosphorescent polymer compound and organic light emitting device.
1. Monomer unit represented by formula (1):

(Wherein R ^{1 to} R ²⁷ each independently represents a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Among R ^{1 to} R ¹⁹ , groups bonded to adjacent carbon atoms of the same phenyl group may be bonded to each other to form a condensed ring, and R ²⁸ is a hydrogen atom or 1 carbon atom. And X represents a single bond, an oxygen atom (—O—), a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, Represents an alkyl group having 1 to 4 carbon atoms or a phenyl group), -CO-, or a divalent organic group having 1 to 20 carbon atoms (provided that the organic group is an oxygen atom (-O-), a sulfur atom (- S -), - SO -, - SO 2 -, - NR- ( where, R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, phenylene And an atom selected from the group consisting of -CO-, or an optionally substituted group.), P is 0 or 1, and a phosphorescent monomer unit. A phosphorescent polymer compound characterized by the above.
2. Monomer unit represented by formula (2):

(Wherein R ^{29 to} R ³⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. X represents a single bond, an oxygen atom (—O— ), Sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group), —CO—, or a divalent organic group having 1 to 20 carbon atoms (where the organic group is an oxygen atom (-O-), a sulfur atom (-S -), - SO - , - SO 2 -, - NR- ( Here, R Represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.) And an atom selected from the group consisting of —CO—, or a group, which may be substituted. 1. The phosphorescent polymer compound according to 1 above, which comprises a phosphorescent monomer unit.
3. 3. The phosphorescent polymer compound according to 1 or 2 further comprising an electron transporting monomer unit.
4). 4. The phosphorescent polymer according to 3 above, wherein the electron transporting site of the electron transporting monomer unit is selected from oxadiazole derivatives, triazole derivatives, triazine derivatives, benzoxazole derivatives, imidazole derivatives, and quinolinol derivative metal complexes. Compound.
5). 3. The phosphorescent polymer compound according to 1 or 2, wherein the phosphorescent monomer unit includes a polymerizable group and a phosphorescent site, and the phosphorescent site is contained in a side chain of the phosphorescent polymer.
6). 3. The phosphorescent polymer compound according to 1 or 2, wherein the phosphorescent monomer unit contains a transition metal complex.
7). 7. An organic light emitting device comprising one or more polymer layers sandwiched between an anode and a cathode, wherein at least one of the polymer layers is an organic material containing the phosphorescent polymer compound described in any one of 1 to 6 above. Light emitting element.
8). 8. The organic light-emitting device as described in 7 above, wherein the anode is subjected to UV ozone irradiation treatment or high-frequency plasma treatment.
9. 9. The organic light emitting device according to 8, wherein the high frequency plasma treatment is treatment with a gas containing an organic substance.
10. 10. The organic light-emitting device according to 9, wherein the gas containing an organic substance is a gas containing at least one of fluorocarbon and / or methane.
11. 9. The organic light-emitting device according to 8 above, wherein the high-frequency plasma treatment is treatment with a gas containing at least one of oxygen and / or argon.

式中、Ｒ¹〜Ｒ²⁷はそれぞれ独立して、水素原子、ハロゲン原子、シアノ基、アミノ基、炭素数１〜６のアルキル基、または炭素数１〜６のアルコキシ基を表す。また、Ｒ¹〜Ｒ¹⁹のうち、同一のフェニル基の隣接する炭素原子にそれぞれ結合している基は、互いに結合して縮合環を形成してもよい。Ｒ²⁸は、水素原子、または炭素数１〜６のアルキル基を表す。Ｘは、単結合、酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）、−ＣＯ−、または炭素数１〜２０の２価の有機基（但し、有機基は酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）および−ＣＯ−からなる群より選択される原子、もしくは基によって置換されていてもよい。）を表す。ｐは０または１である。 Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
According to the present invention, there is provided a phosphorescent polymer compound containing a monomer unit represented by the formula (1) and a phosphorescent monomer unit.

In the formula, R ^{1 to} R ²⁷ each independently represent a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. In addition, among R ^{1 to} R ¹⁹ , groups bonded to adjacent carbon atoms of the same phenyl group may be bonded to each other to form a condensed ring. R ²⁸ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X is a single bond, an oxygen atom (—O—), a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms) Represents a phenyl group), -CO-, or a divalent organic group having 1 to 20 carbon atoms (provided that the organic group is an oxygen atom (-O-), a sulfur atom (-S-), -SO-, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group) and an atom or group selected from the group consisting of —CO— May be). p is 0 or 1;

  The phosphorescent polymer compound of the present invention is a copolymer comprising a monomer unit represented by the formula (1) and a phosphorescent monomer unit. The monomer unit represented by the formula (1) is composed of a part of a triphenylamine structure, a part that forms a polymer chain derived from a carbon-carbon double bond, and a linking group X that connects these parts.

As R < ¹ > -R < ²⁷ > in Formula (1), a hydrogen atom, a halogen atom, a cyano group, an amino group, a C1-C6 alkyl group, or a C1-C6 alkoxy group can be mentioned. Examples of the halogen atom used for R ^{1 to} R ²⁷ include fluorine, chlorine, bromine, and iodine. Examples of the alkyl group having 1 to 6 carbon atoms used for R ^{1 to} R ²⁷ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tertiary butyl group, an amyl group, and a hexyl group. be able to. Examples of the alkoxy group having 1 to 6 carbon atoms used for R ^{1 to} R ²⁷ include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an isobutoxy group, and a tertiary butoxy group. In addition, among R ^{1 to} R ¹⁹ , groups bonded to adjacent carbon atoms of the same phenyl group may be bonded to each other to form a condensed ring.
p is 0 or 1;

  Preferable specific examples of the triphenylamine structure in the formula (1) include structures shown in the formulas (T-1) to (T-11).

Examples of R ²⁸ in formula (1) include a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms used for R ²⁸ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tertiary butyl group, an amyl group, and a hexyl group. .

式中、Ｒ²⁹〜Ｒ³⁴はそれぞれ独立して、水素原子、炭素数１〜６のアルキル基または炭素数１〜６のアルコキシ基を表す。
Ｘは、単結合、酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）、−ＣＯ−、または炭素数１〜２０の２価の有機基（但し、有機基は酸素原子（−Ｏ−）、硫黄原子（−Ｓ−）、−ＳＯ−、−ＳＯ₂−、−ＮＲ−（但し、Ｒは水素原子、炭素数１〜４のアルキル基、フェニル基を表す。）および−ＣＯ−からなる群より選択される原子、もしくは基によって置換されていてもよい。）を表す。ｐは０または１である。 Particularly preferred monomer units of the formula (1) are those having the structure represented by the formula (2).

In the formula, R ^{29 to} R ³⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.
X is a single bond, an oxygen atom (—O—), a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms) Represents a phenyl group), -CO-, or a divalent organic group having 1 to 20 carbon atoms (provided that the organic group is an oxygen atom (-O-), a sulfur atom (-S-), -SO-, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group) and an atom or group selected from the group consisting of —CO— May be). p is 0 or 1;

As the linking group X in the formula (1) or (2), a single bond, an oxygen atom (—O—), a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (provided that R Represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group), -CO-, or a divalent organic group having 1 to 20 carbon atoms (provided that the organic group is an oxygen atom (-O-), A group consisting of a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group) and —CO—. More optionally selected atoms or groups may be substituted). Oxygen atom (—O—), sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a phenyl group. ), -CO-, one or more of these may be contained alone or in combination with other groups. Examples of the linking group X include those having structures represented by formulas (S-1) to (S-15).

Here, R ³⁵ , R ³⁶ and R ³⁷ each independently represent a methylene group or a substituted or unsubstituted phenylene group. k, m and n are each independently 0, 1 or 2.

（式中、（ＰＬ）は燐光発光部位、Ｙは式（１）におけるＸと同様に定義される連結基、Ｒ³⁸は同じくＲ²⁸と同様に定義される置換基である。）。 The phosphorescent monomer unit in the phosphorescent polymer of the present invention is composed of a phosphorescent light emitting site, a portion that forms a polymer chain derived from a carbon-carbon double bond, and a linking group that connects them. That is, typically

(Wherein (PL) is a phosphorescent moiety, Y is a linking group defined in the same manner as X in formula (1), and R ³⁸ is a substituent defined in the same manner as R ²⁸ ).

  As the phosphorescent moiety (PL) in the phosphorescent monomer unit, a monovalent group of a compound that emits phosphorescence at room temperature can be used, but a monovalent group of a transition metal complex is preferable. That is, it is sufficient that one or more ligands are coordinated to the central atom M and any of these ligands is bonded to the linking group Y. The transition metal (M) used in the above transition metal complex includes the first transition element series of the periodic table, that is, Sc of atomic number 21 to Zn of 30 and the second transition element series, that is, Y of 48 of atomic number 39 to 48. Cd of the third transition element series, that is, any metal atom from Hf of atomic number 72 to Hg of 80. Among these transition metals, Pd, Os, Ir, Pt and Au are preferable, and Ir and Pt are particularly preferable.

  In addition, as a ligand of the above transition metal complex, G. Wilkinson (Ed.), Comprehensive Coordination Chemistry (Plenum Press, 1987), Akio Yamamoto, “Organometallic Chemistry-Fundamentals and Applications” 1982) can be used. Among them, halogen ligands, nitrogen-containing heterocyclic ligands (phenylpyridine ligands, benzothienylpyridine ligands, benzoquinoline ligands, quinolinol ligands, bipyridyl ligands, terpyridines Ligands, phenanthroline ligands, etc.), diketone ligands (acetylacetone ligand, dipivaloylmethane ligand, etc.), carboxylic acid ligands (acetic acid ligand, etc.), phosphorus coordination Of these, a trioxide phosphine ligand, a phosphite ligand, a carbon monoxide ligand, an isonitrile ligand, and a cyano ligand are preferred. In addition, pyrazolylborate ligands (hydrotrispyrazolylborate, tetrakispyrazolylborate, etc.) can also be used.

Specific preferred specific examples of the ligand of the transition metal complex include those having structures represented by formulas (L-1) to (L-10).

  One transition metal complex may contain a plurality of types of ligands. Furthermore, a binuclear complex or a polynuclear complex can also be used as the transition metal complex.

The linking group (Y) in the phosphorescent monomer unit is a part that bonds the transition metal complex (PL) and a polymer chain derived from a carbon-carbon double bond. Examples of the linking group include a single bond, an oxygen atom (—O—), a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R is a hydrogen atom, and has 1 to 4 carbon atoms). Represents an alkyl group, a phenyl group), -CO-, or a divalent organic group having 1 to 20 carbon atoms (provided that the organic group is an oxygen atom (-O-), a sulfur atom (-S-),- SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group) and an atom or group selected from the group consisting of —CO— May be substituted). As the divalent organic group having 1 to 20 carbon atoms used for the linking group, the structure represented by the formulas (S-1) to (S-15) is the same as the case of the linking group X in the formula (1). Things can be mentioned.

  The monomer arrangement in the copolymer comprising the monomer unit represented by the formula (1) and the phosphorescent monomer unit may be any of a random copolymer, a block copolymer, and an alternating copolymer. .

  The phosphorescent copolymer of the present invention may contain a third monomer unit in addition to the monomer unit represented by the formula (1) and the phosphorescent monomer unit. As the third monomer unit, other phosphorescent monomer units, hole transporting monomer units, electron transporting monomer units, and bipolar monomer units can be used, Among these, an electron transporting monomer unit is particularly preferable.

  The electron transporting monomer unit that can be used as the third monomer unit is composed of an electron transporting site, a part that forms a polymer chain derived from a carbon-carbon double bond, and a linking group that connects them. The

Examples of the electron transporting site in the electron transporting monomer unit include monovalent groups of oxadiazole derivatives, triazole derivatives, triazine derivatives, benzoxazole derivatives, imidazole derivatives, and quinolinol derivative metal complexes. Specific examples include the structures shown in formulas (E-1) to (E-5).

The linking group in the electron transporting monomer unit is a part that binds the electron transport site and a polymer chain derived from a carbon-carbon double bond. Examples of the linking group include a single bond, an oxygen atom (—O—), a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R is a hydrogen atom, and has 1 to 4 carbon atoms). Represents an alkyl group, a phenyl group), -CO-, or a divalent organic group having 1 to 20 carbon atoms (provided that the organic group is an oxygen atom (-O-), a sulfur atom (-S-),- SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group) and an atom or group selected from the group consisting of —CO— May be substituted). As the divalent organic group having 1 to 20 carbon atoms used for the linking group, the structure represented by the formulas (S-1) to (S-15) is the same as the case of the linking group X in the formula (1). Things can be mentioned.

The degree of polymerization of the polymer used in the present invention is preferably 5 to 10,000, more preferably 10 to 5,000.
Since the molecular weight of the polymer is determined by the molecular weight of the constituent monomer and the degree of polymerization, it is difficult to determine a suitable range for the molecular weight of the polymer used in the present invention. For example, the molecular weight of the polymer used in the present invention is preferably 1,000 to 2,000,000, more preferably 5,000 to 1,000,000 in terms of weight average molecular weight independently of the degree of polymerization.

  Here, as a method for measuring molecular weight, for example, the method described in “Basics of Polymer Chemistry” edited by the Society of Polymer Science (Tokyo Kagaku Dojin, 1978), that is, GPC method (gel permeation chromatography), permeation Examples thereof include a method using pressure, a light scattering method, and an ultracentrifugation method.

  In the phosphorescent polymer of the present invention, the number of repeating phosphorescent monomer units is r, the number of repeating carrier transporting monomer units (the sum of the number of repeating hole transporting monomer units and the number of repeating electron transporting monomer units). Is the ratio of the number of repeating phosphorescent monomer units to the total number of repeating monomer units, that is, the value of r / (r + s) is preferably 0.0001 to 0.2. is there. Further, it is more preferably 0.001 to 0.1. The monomer unit of the formula (1) is generally a hole transporting monomer unit.

  FIG. 1 is a cross-sectional view showing an example of the structure of the organic light-emitting device of the present invention. Between the anode (2) and the cathode (6) provided on the transparent substrate (1), 4) An electron transport layer (5) is sequentially provided. In addition, the organic light emitting device configuration of the present invention is not limited to the example of FIG. 3) hole transport material, light emitting material, layer containing electron transport material, 4) hole transport material, layer containing light emitting material, 5) layer containing light emitting material, electron transport material, 6) Any one of the single layers of the light emitting material may be provided. Moreover, although the light emitting layer shown in FIG. 1 is one layer, two or more light emitting layers may be laminated | stacked.

  In the organic light emitting device of the present invention, the light emitting layer can be formed only from the above phosphorescent polymer compound. In addition, in order to supplement the carrier transport property of the phosphorescent polymer compound, another carrier transport compound can be mixed to form a composition, whereby the light emitting layer can be formed. That is, when the hole transport property of the phosphorescent polymer compound of the present invention is supplemented, the hole transport compound can be mixed, and when the electron transport property is supplemented, the electron transport compound can be mixed. . Here, the carrier transporting compound mixed with the phosphorescent polymer compound may be either a low molecular compound or a polymer compound.

  Examples of the low molecular weight hole transporting compound mixed with the phosphorescent polymer compound include TPD (N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine), α-NPD (4 , 4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), m-MTDATA (4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine) A triphenylamine derivative etc. can be illustrated. In addition, as a polymer hole transporting compound to be mixed with the phosphorescent polymer compound, polyvinylcarbazole, a polymer obtained by introducing a polymerizable functional group into a triphenylamine-based low molecular compound, for example, Examples thereof include a polymer compound having a triphenylamine skeleton disclosed in JP-A-8-15575.

On the other hand, examples of the low molecular electron transport compound mixed with the phosphorescent polymer compound include quinolinol derivative metal complexes such as Al (q) ₃ (trisaluminum quinolinol; q represents quinolinol or a derivative thereof), Examples thereof include oxadiazole derivatives, triazole derivatives, imidazole derivatives, and triazine derivatives. The polymer electron transport compound to be mixed with the phosphorescent polymer compound is a polymer obtained by introducing a polymerizable functional group into the above low molecular electron transport compound, for example, Poly PBD etc. which are indicated by 10-1665 gazette can be illustrated.

  In addition, for the purpose of improving the physical properties of the film obtained by forming the phosphorescent polymer compound, a polymer compound that does not directly contribute to the emission characteristics of the phosphorescent polymer compound is mixed. It can also be used as a light emitting material as a composition. For example, PMMA (polymethyl methacrylate) or the like can be mixed to impart flexibility to the resulting film.

  In the organic light emitting device of the present invention, TPD (N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine), α-NPD (4, 4) 4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), m-MTDATA (4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine) and the like Examples thereof include phenylamine derivatives and polyvinyl carbazole. In addition, a polymer obtained by introducing a polymerizable functional group into a triphenylamine-based low molecular weight compound, for example, a high molecular compound having a triphenylamine skeleton disclosed in JP-A No. 8-175575 can be used. Furthermore, polymer materials such as polyparaphenylene vinylene and polydialkylfluorene can also be used. These hole transport materials may be used alone, but may be mixed or laminated with different hole transport materials. The thickness of the hole transport layer is not particularly limited, but is preferably 1 nm to 5 μm, more preferably 5 nm to 1 μm, and further preferably 10 nm to 500 nm.

In the organic light emitting device of the present invention, as an electron transport material for forming an electron transport layer, quinolinol derivative metal complexes such as Al (q) ₃ (tris aluminum quinolinol), oxadiazole derivatives, triazole derivatives, imidazole derivatives, triazine derivatives Etc. can be illustrated. Further, a polymer obtained by introducing a polymerizable functional group into the above low molecular electron transport compound, for example, poly PBD (2- (4-tert-Butylphenyl) disclosed in JP-A-10-1665. ) -5- (4-biphenylyl) -1,3,4-oxadiazole) can also be used. These electron transport materials are used alone, but may be mixed or laminated with different electron transport materials. Although the thickness of an electron carrying layer is not specifically limited, 1 nm-5 micrometers are preferable, 5 nm-1 micrometer are more preferable, 10 nm-500 nm are further more preferable.

  The phosphorescent polymer compound used for the light emitting layer, the hole transport material used for the hole transport layer, and the electron transport material used for the electron transport layer are each formed as a single layer. Each layer can also be formed. Examples of the polymer material used for this include polymethyl methacrylate, polycarbonate, polyester, polysulfone, polyphenylene oxide, and the like.

  The above light emitting layer, hole transport layer and electron transport layer method can be formed by resistance heating vapor deposition method, electron beam vapor deposition method, sputtering method, ink jet method, spin coating method, printing method, spray method, dispenser method, etc. In the case of low molecular compounds, resistance heating vapor deposition and electron beam vapor deposition are mainly used, and in the case of high molecular compounds, ink jet, printing, and spin coating methods are mainly used.

  Further, a hole block layer may be provided adjacent to the cathode side of the light emitting layer for the purpose of preventing holes from passing through the light emitting layer and efficiently recombining with electrons in the light emitting layer. Examples of the material used for this include triazole derivatives, oxadiazole derivatives, phenanthroline derivatives, and the like.

  As the anode material of the organic light emitting device of the present invention, known transparent conductive materials such as conductive polymers such as ITO (indium tin oxide), tin oxide, zinc oxide, polythiophene, polypyrrole, and polyaniline can be used. The surface resistance of the electrode made of this transparent conductive material is preferably 1 to 50Ω / □ (ohm / square). As a method for forming these anode materials, an electron beam evaporation method, a sputtering method, a chemical reaction method, a coating method, or the like can be used. The thickness of the anode is preferably 50 to 300 nm.

In addition, an anode buffer layer may be inserted between the anode and the hole transport layer or the organic layer laminated adjacent to the anode for the purpose of relaxing the injection barrier against hole injection. For this, copper phthalocyanine, a mixture of polyethylene dioxythiophene (PEDOT) and polystyrene sulfonic acid (PPS), or the like can be used. Further, the surface of the anode can be used after being subjected to various surface treatments. The “surface treatment of the anode” referred to here is performed after the anode is formed on the transparent substrate. Specifically, for example, UV ozone irradiation treatment or high-frequency plasma treatment can be exemplified. Further, examples of the high frequency plasma treatment include (1) coating treatment or etching treatment with a gas containing an organic substance such as fluorocarbon or methane, or (2) etching treatment with a gas such as oxygen or argon.
Any one of these processes may be performed, or a plurality of methods may be performed. Moreover, when performing several methods, there is no restriction | limiting in particular in the order.
The coating treatment by high frequency plasma treatment here is also referred to as “plasma polymerization method”. In addition, the degree of the film treatment or the etching treatment can be controlled by the implementation conditions such as temperature, voltage, and degree of vacuum. Specifically, in the case of coating treatment, it is possible to control the film quality such as the film thickness, water repellency, peel strength or hardness of the thin film to be formed. In the case of etching treatment, the surface is washed or smoothed. Alternatively, it is possible to perform processing that is aggressively scraped off.
The surface treatment of the anode of the organic light emitting device of the present invention is preferably a high frequency plasma treatment, and most preferably a plasma polymerization method using a fluorocarbon gas.

  As the cathode material of the organic light emitting device of the present invention, it is preferable from the viewpoint of electron injection efficiency to use alkali metals such as Li and K having a low work function and alkaline earth metals such as Mg, Ca and Ba. It is also desirable to use Al, MgAg alloy, Al and alkali metal alloys such as AlLi and AlCa, which are chemically stable compared to these metals. In order to achieve both electron injection efficiency and chemical stability, alkali metals such as Cs, Ca, Sr, and Ba are disclosed in JP-A-2-15595 and JP-A-5-111172. Alternatively, a thin layer (about 0.01 to 10 μm) of alkaline earth metal may be sandwiched under the Al layer (the cathode side is the upper side and the anode side is the lower side). As a film forming method of these cathode materials, a resistance heating vapor deposition method, an electron beam vapor deposition method, a sputtering method, an ion plating method, or the like can be used. The thickness of the cathode is preferably 10 nm to 1 μm, and more preferably 50 to 500 nm.

  As the substrate of the organic light emitting device according to the present invention, an insulating substrate transparent to the emission wavelength of the light emitting material can be used. Besides glass, PET (polyethylene terephthalate), polycarbonate, PMMA (polymethyl methacrylate) and the like can be used. Transparent plastic can be used.

The present invention will be described in more detail below with typical examples. Note that these are merely illustrative examples, and the present invention is not limited to these.
The measuring apparatus used is as follows.
1) ¹ H-NMR, ¹³ C-NMR
JNM EX270 made by JEOL
270Mz solvent: deuterated chloroform 2) GPC measurement (molecular weight measurement)
Column: Shodex KF-G + KF804L + KF802 + KF801
Eluent: Tetrahydrofuran (THF)
Temperature: 40 ° C
Detector: RI (Shodex RI-71)
3) ICP elemental analysis ICPS 8000 made by Shimadzu Corporation

下記の操作により、ＴＰＤ（Ｎ，Ｎ'−ビス（３−メチルフェニル）−Ｎ，Ｎ'−ジフェニルベンジジン）に重合性基（ビニル基）を結合させた化合物（１−１）（以下、viTPDという。）を合成した。 Example 1: Synthesis of polymerizable compound viTPD (1-1)

A compound (1-1) in which a polymerizable group (vinyl group) is bonded to TPD (N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine) by the following operation (hereinafter referred to as viTPD). Was synthesized.

(1) Formylation of TPD

Under an argon atmosphere, 11.2 ml of phosphorus oxychloride was added to 200 ml of dehydrated N, N-dimethylformamide, stirred for 30 minutes, and then N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine (TPD ) 51.7 g was added and stirred at 80 ° C. for 2 hours. After the reaction, the reaction solution was added dropwise to 2.5 L of 1.0 M aqueous sodium carbonate solution, and the resulting precipitate was collected by filtration. This precipitate was dissolved in 500 ml of dichloromethane, and 500 ml of pure water was further added. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). The solvent was distilled off to obtain TPD-CHO (1-2) as a yellow solid. Yield 21.6g. Yield 40%. ^When identified by ¹ H-NMR, it was a mixture of two isomers (isomer a and isomer b). ^From the integral value of ¹ H-NMR, the ratio of isomers was estimated as isomer a: isomer b = 28: 72.

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 10.06 (s, 1H, —CHO (isomer b)), 9.82 (s, 1H, —CHO (isomer a)), 7.7-6.8 (m, 25H , ArH (isomer a + isomer b)), 2.54 (s, 3H, —CH ₃ (isomer b)), 2.32 (s, 3H, —CH ₃ (isomer a)), 2.28 (s, 3H , -CH ₃ (isomer a + isomer b)).

(2) Vinylation of TPD-CHO Under argon atmosphere, 100 ml of dehydrated benzene and 50 ml of dehydrated THF were added to 7.86 g of methyltriphenylphosphonium bromide, cooled to 0 ° C, and 13.8 ml of 1.6M butyllithium hexane solution was added dropwise using a syringe. The mixture was then stirred for 10 minutes to obtain a phosphorane solution. Under an argon atmosphere, 100 ml of dehydrated benzene was added to 10.89 g of TPD-CHO (1-2), and then the above phosphorane solution was added using a syringe. After reacting by stirring at room temperature for 2 hours, the reaction solution was analyzed by TLC. As a result, TPD-CHO, which was the raw material, still remained. Stir for 2 hours. Pure water and dichloromethane were added to the reaction solution, and the aqueous layer was extracted twice with dichloromethane. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). The desired product was obtained by lyophilization from a benzene solution. Yield 8.26g. Yield 72%. ^When identified by ¹ H-NMR, it was a mixture (1-1) of two kinds of isomers (viTPD isomer a and viTPD isomer b).

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 7.5-6.8 (m, 25H (isomer a + isomer b) + 1H (isomer b), ArH (isomer a + isomer b) + -CH = CH ₂ (isomer b)), 6.67 (dd, 1H, J = 17.4, 11.2Hz, -CH = CH ₂ (isomer a)), 5.64 (d, 1H, J = 17.8Hz, -CH = CH ₂ (cis) (isomer a)), 5.58 (d, 1H, J = 17.6 Hz, -CH = CH ₂ (cis) (isomer b)), 5.21 (d, 1H, J = 11.1 Hz, -CH = CH ₂ (trans) (isomer b)), 5.16 (d, 1H, J = 15.4Hz, -CH = CH ₂ (trans) (isomer a)), 2.26 (s, 6H, -CH ₃ (isomer) Isomer a + isomer b)).

Example 2: Synthesis of polymerizable compound viPMTPD (2-1)

(1) Ditrylation of 3,3′-dimethylbenzidine Under an argon atmosphere, 80 ml of dehydrated xylene was added to 5 g of 3,3′-dimethylbenzidine and 11.30 g of 3-iodotoluene, and the mixture was heated to about 50 ° C. To this, 6.82 g of tert-butoxypotassium, 230 mg of palladium acetate, and 460 mg of tri-tert-butylphosphine were sequentially added, and the mixture was stirred at 120 ° C. for 4 hours. After cooling to room temperature, 50 ml of pure water was added to the reaction solution, and the mixture was extracted twice with ethyl acetate. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: mixed solvent of ethyl acetate-hexane). After the solvent was distilled off, recrystallization from methanol gave 3,3′-dimethyl-N, N′-di-m-tolylbenzidine (2-2). Yield 4.00g. Yield 49%. Identification was performed by ¹ H-NMR.

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 7.42 (d, 2H, J = 1.6 Hz, ArH), 7.36 (dd, 2H, J = 8.2, 2.0 Hz, ArH), 7.28 (d, 2H, J = 8.1Hz, ArH), 7.16 (t, 2H, J = 8.0Hz, ArH), 6.81 (m, 4H, ArH), 6.73 (d, 2H, J = 7.6Hz, ArH), 5.37 (s, 2H, -NH), 2.31 (s, 12H , -CH 3).

(2) Tolylation of 3,3′-dimethyl-N, N′-di-m-tolylbenzidine 3,3′-dimethyl-N, N′-di-m-tolylbenzidine (2- 2) 50 ml of dehydrated xylene was added to 4.00 g and 2.64 g of 3-iodobenzene and heated to about 50 ° C. To this, 1.27 g of tert-butoxypotassium, 225 mg of palladium acetate, and 200 mg of tri-tert-butylphosphine were sequentially added, and the mixture was stirred at 120 ° C. for 4 hours. After cooling to room temperature, 30 ml of pure water was added to the reaction solution, and the mixture was extracted twice with ethyl acetate. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and then purified by silica gel column chromatography (developing solution: toluene-hexane mixed solvent). After the solvent was distilled off, recrystallization from hexane gave 3,3′-dimethyl-N, N, N′-tri-m-tolylbenzidine (2-3). Yield 3.37g. Yield 70%. Identification was performed by ¹ H-NMR.

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 7.45 (d, 2H, J = 2.7 Hz, ArH), 7.43 (d, 2H, J = 8.1 Hz, ArH), 7.4-7.0 (m, 6H, ArH ), 6.9-6.7 (m, 8H, ArH), 5.40 (s (br), 1H, -NH), 2.32 (s, 6H, -CH ₃ ), 2.25 (s, 6H, -CH ₃ ), 2.08 ( s, 3H, -CH ₃ ).

(3) Styrylation Under an argon atmosphere, 20 ml of dehydrated toluene was added to 1.93 g of 3,3′-dimethyl-N, N, N′-tri-m-tolylbenzidine (2-3) and 589 mg of tert-butoxypotassium. Thereafter, 0.58 ml of 4-bromostyrene, 9.0 mg of palladium acetate, and 28.3 mg of tri-tert-butylphosphine were sequentially added, and the mixture was refluxed with stirring for 3.5 hours. After cooling to room temperature, 20 ml of pure water and 20 ml of ethyl acetate were added, and the aqueous layer was further extracted twice with dichloromethane. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and then purified by silica gel column chromatography (developing solution: toluene-hexane mixed solvent). The solvent was distilled off and lyophilized from benzene to obtain viPMTPD (2-1) as a white solid. Yield 1.66 g. Yield 71%. Identification was performed by ¹ H-NMR.

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 7.5-6.7 (m, 22H, ArH), 6.65 (dd, 1H, J = 17.4, 10.9 Hz, -CH = CH ₂ ), 5.61 (d, 1H, J = 17.6Hz, -CH = CH ₂ (cis)), 5.12 (d, 1H, J = 11.1Hz, -CH = CH ₂ (trans)), 2.25 (s, 9H, -CH ₃ ), 2.08 (s , 6H, -CH ₃ ).

Example 3: Synthesis of copolymer poly- (viTPD-co-IrST)

  In a closed container, 920 mg of viTPD (1-1) prepared in Example 1 and 80 mg of IrST (formula (3-1), synthesized according to the method described in JP-A-2003-113246) were placed and dehydrated. After adding 9.0 ml of toluene, 181 μl of a 0.1M toluene solution of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the freeze degassing operation was repeated 5 times. Sealed in vacuum and stirred at 60 ° C. for 72 hours. After the reaction, the reaction solution was dropped into 300 ml of acetone to cause precipitation. Further, reprecipitation purification with toluene-acetone was repeated twice, followed by vacuum drying at 50 ° C. overnight to obtain 750 mg of poly- (viTPD-co-IrST) as a pale yellow solid. The molecular weight of the obtained copolymer was estimated as number average molecular weight (Mn) 19700, weight average molecular weight (Mw) 50300, and molecular weight distribution index (Mw / Mn) 2.55 from GPC measurement in terms of polystyrene. The iridium element content in the copolymer was 1.5% by mass based on ICP elemental analysis. From this, the copolymerization ratio of the copolymer was estimated to be viTPD: IrST = 94.4: 5.6 (mass ratio).

Example 4: Synthesis of copolymer poly- (viPMTPD-co-IrST)

  In a sealed container, 920 mg of viPMTPD (2-1) and 80 mg of IrST (3-1) prepared in Example 2 were added, 8.4 ml of dehydrated toluene was added, and then 0.1M toluene of V-601 (manufactured by Wako Pure Chemical Industries). 169 μl of the solution was added, and the freeze degassing operation was repeated 5 times. Sealed in vacuum and stirred at 60 ° C. for 72 hours. After the reaction, the reaction solution was dropped into 300 ml of acetone to cause precipitation. Further, reprecipitation purification with toluene-acetone was repeated twice, followed by vacuum drying at 50 ° C. overnight to obtain 812 mg of poly- (viPMTPD-co-IrST) as a pale yellow solid. The molecular weight of the obtained copolymer was estimated as number average molecular weight (Mn) 24300, weight average molecular weight (Mw) 59400, and molecular weight distribution index (Mw / Mn) 2.44 by GPC measurement in terms of polystyrene. The iridium element content in the copolymer was 1.6% by mass based on ICP elemental analysis. From this, the copolymerization ratio of the copolymer was estimated to be viPMTPD: IrST = 94.0: 6.0 (mass ratio).

Example 5: Synthesis of copolymer poly- (viTPD-co-viPBD-co-IrST)

Place 460 mg of viTPD (1-1), viPBD (formula (5-1), synthesized according to the method described in JP-A-10-1665) 460 mg, IrST (3-1) 80 mg in a sealed container. After adding 10.8 ml of dehydrated toluene, 217 μl of 0.1M toluene solution of V-601 (manufactured by Wako Pure Chemical Industries) was added, and the freeze degassing operation was repeated 5 times. The mixture was sealed under vacuum and stirred at 60 ° C. for 96 hours. After the reaction, the reaction solution was dropped into 300 ml of acetone to cause precipitation. Further, reprecipitation purification with toluene-acetone was repeated twice, followed by vacuum drying at 50 ° C. overnight to obtain 789 mg of poly- (viTPD-co-viPBD-co-IrST) as a pale yellow solid. The molecular weight of the obtained copolymer was estimated as number average molecular weight (Mn) 21400, weight average molecular weight (Mw) 46600, and molecular weight distribution index (Mw / Mn) 2.17 from GPC measurement in terms of polystyrene. The iridium element content in the copolymer was 1.5% by mass based on ICP elemental analysis. From this and ¹³ C-NMR measurement, the copolymerization ratio of the copolymer was estimated as viTPD: viPBD: IrST = 43.1: 51.3: 5.6 (mass ratio).

Example 6: Synthesis of copolymer poly- (viPMTPD-co-viPBD-co-IrST)

Put viPMTPD (2-1) 460 mg, viPBD (5-1) 460 mg, IrST (3-1) 80 mg in a sealed container, add 10.5 ml of dehydrated toluene, and then add 0.15 ml of V-601 (manufactured by Wako Pure Chemical Industries). 211 μl of M toluene solution was added, and freeze deaeration operation was repeated 5 times. The mixture was sealed under vacuum and stirred at 60 ° C. for 96 hours. After the reaction, the reaction solution was dropped into 300 ml of acetone to cause precipitation. Further, reprecipitation purification with toluene-acetone was repeated twice, followed by vacuum drying at 50 ° C. overnight to obtain 810 mg of poly- (viPMTPD-co-viPBD-co-IrST) as a pale yellow solid. The molecular weight of the obtained copolymer was estimated as number average molecular weight (Mn) 26600, weight average molecular weight (Mw) 62200, and molecular weight distribution index (Mw / Mn) 2.34 from GPC measurement in terms of polystyrene. The iridium element content in the copolymer was 1.5% by mass based on ICP elemental analysis. From this and the result of ¹³ C-NMR measurement, the copolymerization ratio of the copolymer was estimated to be viPMTPD: viPBD: IrST = 44.2: 50.2: 5.6 (mass ratio).

Example 7: Synthesis of copolymer poly- (viTPD-co-viOXD7-co-IrST)

Put viTPD (1-1) 460 mg, viOXD7 (7-1) 460 mg, IrST (3-1) 80 mg in a sealed container, add 11.7 ml of dehydrated toluene, and then add 0.1 ml of V-601 (manufactured by Wako Pure Chemical Industries). 235 μl of M toluene solution was added, and freeze deaeration operation was repeated 5 times. The mixture was sealed under vacuum and stirred at 60 ° C. for 96 hours. After the reaction, the reaction solution was dropped into 300 ml of acetone to cause precipitation. Further, reprecipitation purification with toluene-acetone was repeated twice, followed by vacuum drying at 50 ° C. overnight to obtain 750 mg of poly- (viTPD-co-viOXD7-co-IrST) as a pale yellow solid. The molecular weight of the obtained copolymer was estimated as number average molecular weight (Mn) 19700, weight average molecular weight (Mw) 67300, molecular weight distribution index (Mw / Mn) 3.42 from GPC measurement in terms of polystyrene. The iridium element content in the copolymer was 1.5% by mass based on ICP elemental analysis. From this and ¹³ C-NMR measurement, the copolymerization ratio of the copolymer was estimated to be viTPD: viOXD7: IrST = 46.4: 48.0: 5.6 (mass ratio).

Example 8: Synthesis of copolymer poly- (viTPD-co-viPBD-co-IrST (R))

ViTPD (1-1) 460 mg, viPBD (5-1) 460 mg, IrST (R) (Formula (8-1), synthesized according to the method described in JP-A-2003-147021) in a sealed container. After adding 80 mg of dehydrated toluene and adding 10.8 ml of dehydrated toluene, 215 μl of 0.1M toluene solution of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and freeze deaeration operation was repeated 5 times. The mixture was sealed under vacuum and stirred at 60 ° C. for 96 hours. After the reaction, the reaction solution was dropped into 300 ml of acetone to cause precipitation. Further, reprecipitation purification with toluene-acetone was repeated twice, followed by vacuum drying at 50 ° C. overnight to obtain 773 mg of poly- (viTPD-co-viPBD-co-IrST (R)) as a light red solid. Obtained. The molecular weight of the obtained copolymer was estimated as number average molecular weight (Mn) 22100, weight average molecular weight (Mw) 50100, and molecular weight distribution index (Mw / Mn) 2.27 from GPC measurement in terms of polystyrene. The iridium element content in the copolymer was 1.6% by mass based on ICP elemental analysis. From this and ¹³ C-NMR measurement, the copolymerization ratio of the copolymer was estimated as viTPD: viPBD: IrST (R) = 42.9: 50.2: 6.9 (mass ratio).

Example 9: Synthesis of polymerizable compound viMeOTPD (9-1)

(1) Bismethoxyphenylation of N, N′-diphenylbenzidine Under an argon atmosphere, 160 ml of dehydrated toluene was added to 11.30 g of N, N′-diphenylbenzidine and 17.30 g of 4-iodoanisole and heated to about 50 ° C. To this, 9.05 g of tert-butoxypotassium, 302 mg of baradium acetate, and 816 mg of tri-tert-butylphosphine were sequentially added, and the mixture was refluxed with stirring for 4 hours. After cooling to room temperature, 100 ml of pure water was added to the reaction solution, and the mixture was extracted twice with ethyl acetate. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: ethyl acetate-hexane mixed solvent). After the solvent was distilled off, recrystallization from hexane gave MeOTPD (9-2). Yield 11.98 g. Yield 65%. Identification was performed by ¹ H-NMR.

¹ H-NMR (270 MHz, CDC1 ₃ , ppm): 7.40 (d, 4H, J = 8.6 Hz, ArH), 7.21 (d, 4H, J = 7.3 Hz, ArH), 7.2-7.0 (m, 12H, ArH ), 6.95 (t, 2H, J = 7.4, ArH), 6.85 (d, 4H, J = 8.9Hz, ArH), 3.81 (s, 6H, -OCH 3).

(2) Formylation of MeOTPD Under argon atmosphere, 1.12 ml of phosphorus oxychloride was added to 20 ml of dehydrated N, N-dimethylformamide, stirred for 30 minutes, and then 5.49 g of MeOTPD (9-2) was added. Stir for hours. After the reaction, the reaction solution was added dropwise to 250 mL of 1.0 M aqueous sodium carbonate solution, and the resulting precipitate was collected by filtration. This precipitate was dissolved in 50 ml of dichloromethane, and 50 ml of pure water was further added. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). The solvent was distilled off to obtain MeOTPD-CHO (9-3) as a yellow solid. Yield 2.65g. Yield 46%. Identification was performed by ¹ H-NMR.
¹ H-NMR (270 MHz, CDCl ₃ , ppm): 10.08 (s, 1H, —CHO), 7.7-6.8 (m, 25H, ArH), 3.85 (s, 6H, —OCH ₃ ).

(3) Vinylation of MeOTPD-CHO Under argon atmosphere, 20 ml of dehydrated benzene and 10 ml of dehydrated THF were added to 2.14 g of methyltriphenylphosphonium bromide, cooled to 0 ° C., and 3.75 ml of 1.6 M butyl lithium hexane solution was added dropwise using a syringe. The mixture was then stirred for 10 minutes to obtain a phosphorane solution. Under an argon atmosphere, 20 ml of dehydrated benzene was added to 2.31 g of MeOTPD-CHO (9-3), and then the above phosphorane solution was added using a syringe. After stirring at room temperature for 2 hours, 20 ml of pure water and dichloromethane were added to the reaction solution, and the aqueous layer was extracted twice with dichloromethane. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and then purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). ViMeOTPD was obtained by lyophilization from a benzene solution. Yield 1.72g. Yield 75%. Identification was performed by ¹ H-NMR.

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 7.5-6.8 (m, 25H, ArH), 6.65 (dd, 1H, J = 17.6, 10.9 Hz, one CH = CH ₂ ), 5.62 (d, 1H, _{J = 17.3Hz, -CH = CH 2} (cis)), 5.12 (d, 1H, J = 11.1Hz, -CH = CH 2 (trans)), 3.80 (s, 6H, -OCH 3).

Example 10: Synthesis of polymerizable compound viNPD (10-1)

(1) Formylation of 4,4′-bis (N-naphthyl-N-phenyl-amino) biphenyl Under argon atmosphere, 2.24 ml of phosphorus oxychloride was added to 40 ml of dehydrated N, N-dimethylformamide and stirred for 30 minutes. Thereafter, 11.77 g of 4,4′-bis (N-naphthyl-N-phenyl-amino) biphenyl was added, and the mixture was stirred at 80 ° C. for 2 hours. After the reaction, the reaction solution was added dropwise to 500 ml of 1.0 M aqueous sodium carbonate solution, and the resulting precipitate was collected by filtration. This precipitate was dissolved in 100 ml of dichloromethane, and 100 ml of pure water was further added. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). The solvent was distilled off to obtain NPD-CHO (10-2) as a yellow solid. Yield 3.21g. Yield 26%. Identification was performed by ¹ H-NMR.
^{1 H-NMR (270MHz, CDC1} 3, ppm): 9.90 (s, 1H, -CHO), 7.8-6.8 (m, 31H, ArH).

(2) Vinylation of NPD-CHO Under argon atmosphere, 20 ml of dehydrated benzene and 10 ml of dehydrated THF were added to 2.68 g of methyltriphenylphosphonium bromide, cooled to 0 ° C., and 4.69 ml of 1.6 M butyl lithium hexane solution was added dropwise using a syringe. The mixture was then stirred for 10 minutes to obtain a phosphorane solution. Under an argon atmosphere, 20 ml of dehydrated benzene was added to 3.08 g of NPD-CHO (10-2), and then the above phosphorane solution was added using a syringe. After stirring at room temperature for 2 hours, 20 ml of pure water and dichloromethane were added to the reaction solution, and the aqueous layer was extracted twice with dichloromethane. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and then purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). It was lyophilized from a benzene solution to obtain viNPD (10-1). Yield 2.43g. Yield 79%. Identification was performed by ¹ H-NMR.

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 7.8-6.8 (m, 31H, ArH), 6.68 (dd, 1H, J = 17.4, 10.9 Hz, -CH = CH ₂ ), 5.63 (d, 1H, _{J = 17.6Hz, -CH = CH 2} (cis)), 5.15 (d, 1H, J = 11.1Hz, -CH = CH 2 (trans)).

Example 11: Synthesis of polymerizable compound viPTPD (11-1)

(1) Ditrylation of N, N′-diphenyl-1,4-phenylenediamine Under an argon atmosphere, 5.21 g of N, N′-diphenyl-1,4-phenylenediamine, 9.59 g of 4-iodotoluene and 100 ml of dehydrated toluene And heated to about 50 ° C. To this, 5.39 g of potassium tert-butoxy, 90 mg of baradium acetate, and 243 mg of tri-tert-butylphosphine were added in this order, and the mixture was refluxed with stirring for 4 hours. After cooling to room temperature, 50 ml of pure water was added to the reaction solution, and the mixture was extracted twice with ethyl acetate. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: a mixed solution of toluene-hexane). After the solvent was distilled off, recrystallization from hexane gave PTPD (11-2). Yield 6.43g. Yield 73%. Identification was performed by ¹ H-NMR.
¹ H-NMR (270 MHz, CDC 1 ₃ , ppm): 7.5-6.8 (m, 22H, ArH), 2.25 (s, 6H, —CH ₃ ).

(2) Formylation of PTPD In an argon atmosphere, 1.12 ml of phosphorus oxychloride was added to 20 ml of dehydrated N, N-dimethylformamide, stirred for 30 minutes, and then 4.41 g of PTPD (11-2) was added. Stir for hours. After the reaction, the reaction solution was added dropwise to 250 ml of 1.0 M aqueous sodium carbonate solution, and the resulting precipitate was collected by filtration. This precipitate was dissolved in 50 ml of dichloromethane, and 50 ml of pure water was further added. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). The solvent was distilled off to obtain PTPD-CHO (11-3) as a yellow solid. Yield 2.06g. Yield 44%. Identification was performed by ¹ H-NMR.
¹ H-NMR (270 MHz, CDCl ₃ , ppm): 9.99 (s, 1H, —CHO), 7.7-6.8 (m, 21H, ArH), 2.28 (s, 6H, —CH ₃ ).

(3) Vinylation of PTPD-CHO Under argon atmosphere, 20 ml of dehydrated benzene and 10 ml of dehydrated THF were added to 2.14 g of methyltriphenylphosphonium bromide, cooled to 0 ° C., and 3.75 ml of 1.6 M butyllithium hexane solution was used with a syringe. The solution was added dropwise and stirred for 10 minutes to obtain a phosphorane solution. Under an argon atmosphere, 20 ml of dehydrated benzene was added to 1.87 g of PTPD-CHO (11-3), and then the above phosphorane solution was added using a syringe. After stirring at room temperature for 2 hours, 20 ml of pure water and dichloromethane were added to the reaction solution, and the aqueous layer was extracted twice with dichloromethane. The organic layer was dried over magnesium sulfate, concentrated under reduced pressure, and then purified by silica gel column chromatography (developing solution: dichloromethane-hexane mixed solvent). It was freeze-dried from a benzene solution to obtain viPTPD (11-1). Yield 1.46g. Yield 78%. Identification was performed by ¹ H-NMR.

¹ H-NMR (270 MHz, CDCl ₃ , ppm): 7.5-6.9 (m, 21H, ArH), 6.66 (dd, 1H, J = 17.6, 11.1 Hz, -CH = CH ₂ ), 5.62 (d, 1H, _{J = 17.3Hz, -CH = CH 2} (cis)), 5.14 (d, 1H, J = 10.8Hz, -CH = CH 2 (trans)).

Comparative Example 1: Synthesis of copolymer poly- (VCz-co-viPBD-co-IrST) N-vinylcarbazole (VCz) 460 mg, viPBD (5-1) 460 mg, and IrST (3-1) 80 mg were placed in a sealed container. After adding 5.60 ml of dehydrated toluene, 3.70 ml of 0.1M toluene solution of V-601 (low VOC type radical initiator, manufactured by Wako Pure Chemical Industries, Ltd.) was added, and freeze degassing operation was repeated 5 times. Sealed in vacuum and stirred at 60 ° C. for 72 hours. After the reaction, the reaction solution was dropped into 500 ml of methanol to cause precipitation. Further, reprecipitation purification with toluene-acetone was repeated twice, followed by vacuum drying at 50 ° C. overnight to obtain 953 mg of poly- (VCz-co-viPBD-co-IrST) as a pale yellow solid. The molecular weight of the obtained copolymer was estimated as number average molecular weight (Mn) 4700, weight average molecular weight (Mw) 12500, and molecular weight distribution index (Mw / Mn) 2.64 from GPC measurement in terms of polystyrene. The iridium element content in the copolymer was 1.9% by mass based on ICP elemental analysis. From this, the copolymerization ratio of the copolymer was estimated to be VCz: viPBD: IrST = 45.7: 47.2: 7.1 (mass ratio).

Example 12: Production of organic light-emitting device and evaluation of EL light emission characteristics On one surface of a 25 mm square glass substrate, with ITO (indium tin oxide) in which two ITO electrodes with a width of 4 mm serving as an anode were formed in a stripe shape An organic light emitting device was manufactured using a substrate (Nippo Electric Co., LTD.). First, poly (3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (trade name “Vitron P”, manufactured by Bayer Co., Ltd.) on the ITO (anode) of the substrate with ITO is rotated at 3500 rpm. After coating under the condition of a coating time of 40 seconds, drying was performed at 60 ° C. for 2 hours under reduced pressure in a vacuum dryer to form an anode buffer layer. The film thickness of the obtained anode buffer layer was about 50 nm.

  Next, a coating solution for forming a layer containing a light emitting material and an electron transport material was prepared. That is, 45 mg of poly- (viTPD-co-IrST) synthesized in Example 3 and 45 mg of poly-vinylPBD synthesized by the method described in JP-A-10-1665 were added to 2910 mg of toluene (special grade, manufactured by Wako Pure Chemical Industries). The resulting solution was filtered through a filter having a pore size of 0.2 μm to obtain a coating solution. Next, on the anode buffer layer, the prepared coating solution was applied by spin coating under the conditions of a rotation speed of 3000 rpm and a coating time of 30 seconds, and dried at room temperature (25 ° C.) for 30 minutes, whereby the light emitting layer was formed. Formed. The film thickness of the obtained light emitting layer was about 100 nm. Next, the substrate on which the light emitting layer is formed is placed in a vapor deposition apparatus, and cesium is vapor deposited at a vapor deposition rate of 0.01 nm / s to a thickness of 2 nm (as a cesium source, an alkali metal dispenser manufactured by SAES Getters is used) Subsequently, aluminum was deposited as a cathode at a deposition rate of 1 nm / s to a thickness of 250 nm, and the device 1 was manufactured. The cesium and aluminum layers are formed in two stripes with a width of 3 mm perpendicular to the extending direction of the anode, and four organic light emitting elements 4 mm long × 3 mm wide per glass substrate. Produced.

Using a programmable DC voltage / current source TR6143 manufactured by Advantest Co., Ltd., voltage was applied to the organic EL element to emit light, and the emission luminance was measured using a luminance meter BM-8 manufactured by Topcon Corporation. The resulting light emission starting voltage, maximum luminance, and external quantum efficiency at 100 cd / m ² lighting are shown in Table 2 (each value is an average value of four elements formed on one substrate).

  As described in Table 1, with respect to the element 1, the elements 2 to 7 were produced in the same manner as the element 1 except that the light emitting materials synthesized in Examples 4 to 8 and Comparative Example 1 and other materials were changed. did. Table 2 shows the results of evaluating the EL emission characteristics of these elements in the same manner as the element 1.

  From Tables 1 and 2, the phosphorescent property using a triphenylamine structure for the hole transporting portion of the present invention is compared with the light emitting device using a phosphorescent polymer using vinylcarbazole for the hole transporting portion as a comparative example. It can be seen that a light-emitting element using a polymer has a low emission start voltage, a high maximum luminance, and a high external quantum efficiency.

  Provided is a phosphorescent polymer material which can obtain high luminous efficiency at a low voltage and is suitable for large area and mass production by using the phosphorescent polymer compound of the present invention, and an organic light emitting device using the same. Is possible.

It is sectional drawing of one embodiment of an organic light emitting element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Anode 3 Hole transport layer 4 Light emitting layer 5 Electron transport layer 6 Cathode

Claims (11)

Formula (1):

(Wherein R ^{1 to} R ²⁷ each independently represents a hydrogen atom, a halogen atom, a cyano group, an amino group, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Among R ^{1 to} R ¹⁹ , groups bonded to adjacent carbon atoms of the same phenyl group may be bonded to each other to form a condensed ring, and R ²⁸ is a hydrogen atom or 1 carbon atom. And X represents a single bond, an oxygen atom (—O—), a sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, Represents an alkyl group having 1 to 4 carbon atoms or a phenyl group), -CO-, or a divalent organic group having 1 to 20 carbon atoms (provided that the organic group is an oxygen atom (-O-), a sulfur atom (- S -), - SO -, - SO 2 -, - NR- ( where, R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, phenylene And an atom selected from the group consisting of -CO-, or an optionally substituted group, and p is 0 or 1. The monomer unit represented by and phosphorescent A phosphorescent polymer compound comprising a monomer unit. Formula (2):

(Wherein R ^{29 to} R ³⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. X represents a single bond, an oxygen atom (—O— ), Sulfur atom (—S—), —SO—, —SO ₂ —, —NR— (wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group), —CO—, or a divalent organic group having 1 to 20 carbon atoms (where the organic group is an oxygen atom (-O-), a sulfur atom (-S -), - SO - , - SO 2 -, - NR- ( Here, R Represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.) And an atom selected from the group consisting of —CO—, or a group, which may be substituted. The phosphorescent polymer according to claim 1, comprising a monomer unit represented by formula (1) and a phosphorescent monomer unit. Compound.   The phosphorescent polymer compound according to claim 1, further comprising an electron transporting monomer unit.   The highly phosphorescent light-emitting region according to claim 3, wherein the electron transporting site of the electron transporting monomer unit is selected from an oxadiazole derivative, a triazole derivative, a triazine derivative, a benzoxazole derivative, an imidazole derivative, and a quinolinol derivative metal complex. Molecular compound.   The phosphorescent polymer compound according to claim 1 or 2, wherein the phosphorescent monomer unit includes a polymerizable group and a phosphorescent site, and the phosphorescent site is contained in a side chain of the phosphorescent polymer.   The phosphorescent polymer compound according to claim 1 or 2, wherein the phosphorescent monomer unit contains a transition metal complex.   In the organic light emitting device including one or a plurality of polymer layers sandwiched between an anode and a cathode, at least one of the polymer layers includes the phosphorescent polymer compound according to any one of claims 1 to 6. Organic light emitting device.   The organic light emitting element according to claim 7, wherein the anode is subjected to UV ozone irradiation treatment or high frequency plasma treatment.   The organic light-emitting device according to claim 8, wherein the high-frequency plasma treatment is treatment with a gas containing an organic substance.   The organic light emitting element according to claim 9, wherein the gas containing an organic substance is a gas containing at least one of fluorocarbon and / or methane.   The organic light-emitting device according to claim 8, wherein the high-frequency plasma treatment is treatment with a gas containing at least one of oxygen and / or argon.

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