JP2008280506A - Material for organic electronics, organic electronic element and organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for organic electronics which can be easily used in a multilayer element capable of forming a high-quality thin film and of emitting phosphorescence. <P>SOLUTION: The organic electronic material comprises a polymer or oligomer having, in one molecule, one or more polymerizable substituents and one or more metal complex structural units, wherein it is preferable that the metal complex contains Ir or Pt as the central metal atom and has a carbazole ring as the structural unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic electronics material, and an organic electronics element and an organic electroluminescence element (hereinafter sometimes referred to as an organic EL element) using the organic electronics material.

  Organic electronics elements are elements that perform electrical operations using organic substances, and are expected to exhibit features such as energy saving, low cost, and flexibility, and are attracting attention as a technology that can replace conventional inorganic semiconductors based on silicon. ing.

  Among organic electronics elements, organic EL elements are attracting attention as applications for large-area solid-state light sources as an alternative to incandescent lamps and gas-filled lamps, for example. It is also attracting attention as the most powerful self-luminous display that can replace the liquid crystal display (LCD) in the flat panel display (FPD) field, and its commercialization is progressing.

  The organic EL element has a configuration in which a thin film made of an organic compound is sandwiched between a cathode and an anode, and the method of forming the thin film is roughly divided into a vapor deposition method and a coating method. The vapor deposition method is a technique in which a low molecular compound is mainly used and a thin film is formed on a substrate in a vacuum, and commercialization by the vapor deposition method has preceded. On the other hand, the coating method is a method of forming a thin film on a substrate using a coating liquid, such as ink jet or printing, and the use efficiency of the material is high, and it is suitable for large area and high definition. This is an indispensable technique for screen organic EL displays.

Although organic EL elements using either method have been energetically studied so far, low luminous efficiency and short element lifetime still pose major problems. As one means for solving this problem, multilayering is performed in an organic EL element by a vapor deposition method.
FIG. 1 shows an example of a multilayered organic EL element. In FIG. 1, a layer responsible for light emission is referred to as a light emitting layer, and when it has other layers, a layer in contact with the anode is referred to as a hole injection layer, and a layer in contact with the cathode is referred to as an electron injection layer. In addition, when another layer exists between the light emitting layer and the hole injection layer, it is referred to as a hole transport layer, and when another layer exists between the light emitting layer and the electron injection layer, Called.

  When film formation is performed by a vapor deposition method, multilayering can be easily achieved by performing vapor deposition while sequentially changing the compounds to be used. On the other hand, in the case of the coating method, in order to increase the number of layers, it is necessary to have a method that does not change the already formed layer when forming a new layer.

  Many organic EL devices by the coating method are formed using a polythiophene: polystyrene sulfonic acid (PEDOT: PSS) hole injection layer, which is formed using an aqueous dispersion, and an aromatic organic solvent such as toluene. The light emitting layer has a two-layer structure. In this case, since the PEDOT: PSS layer is not dissolved in toluene, a two-layer structure can be produced.

  However, when the lamination is performed using a similar solvent, the lower layer is dissolved, so that it is difficult to further increase the number of layers in the organic EL element by the coating method. In order to cope with this problem, a technique is known in which a low molecular compound having a polymerizable substituent is applied and the solubility is changed by polymerization to form a multilayer structure (for example, Non-Patent Document 1, Patent Document 1). However, low-molecular compounds tend to be crystallized, and there is a problem that it is difficult to form a high-quality thin film.

  On the other hand, in recent years, phosphorescent organic EL elements have been actively developed in order to increase the efficiency of organic EL elements. In the phosphorescent organic EL element, not only singlet state energy but also triplet state energy can be used, and the internal quantum yield can be increased to 100% in principle. In the phosphorescent organic EL element, phosphorescence is extracted by doping a host material with a metal complex light emitting material containing a heavy metal such as platinum or iridium as a dopant that emits phosphorescence (see, for example, Non-Patent Documents 2 to 4). ).

  The emission of this phosphorescent dopant has a dependence on the host material. The basic performance required for the host material includes a hole transport property and an electron transport property, and the host material has a high triplet state energy level. Generally, CBP (4,4′- A carbazole derivative such as Bis (Carbazol-9-yl) -biphenyl) is preferably used (for example, see Patent Document 2).

  However, a charge transport material such as CBP used as a host material in an organic EL element using a phosphorescent material is easily crystallized, and film formation by a coating method is difficult. In addition, even when a low-molecular phosphorescent material is dissolved or dispersed in a solvent to prepare a coating liquid, the solubility and dispersibility are poor, so a uniform and stable coating liquid cannot be obtained, and film formation Even if possible, there were drawbacks such as poor film stability.

  On the other hand, in general, polyfluorene derivatives, polyparaphenylene vinylene (PPV) derivatives, and the like are widely used in the organic EL elements by the coating method, but these have a low triplet state energy level and are phosphorescent organic EL elements. It was insufficient as a host material. From such a background, a material that can be formed and laminated by a coating method and that can utilize phosphorescence has been strongly desired.

JP 2006-279007 A JP 2003-68466 A Kengo Hirose, Daisuke Kumaki, Nobuaki Koike, Satoshi Kuriyama, Seiichiro Ikehata, Shizushi Tokito, 53rd Joint Physics Conference on Applied Physics, 26p-ZK-4 (2006) M.M. A. Baldo et al. , Nature, vol. 395, p. 151 (1998) M.M. A. Baldo et al. , Applied Physics Letters, vol. 75, p. 4 (1999) M.M. A. Baldo et al. , Nature, vol. 403, p. 750 (2000)

  In order to increase the efficiency and life of the organic EL element, it is preferable to divide the organic layer into multiple layers and separate the functions of each layer. In order to achieve this, there has been a demand for a material that can form a high-quality thin film by coating without dissolving the lower layer during upper film formation. Furthermore, from the viewpoint of high efficiency, it has been desired that such a material is a phosphorescent material.

  In view of the above problems, an object of the present invention is to provide a phosphorescent organic electronic material that can be easily multilayered and can form a high-quality thin film. Furthermore, an object of the present invention is to provide an organic electronics element and an organic EL element using the organic electronics material.

  As a result of intensive studies, the present inventors have stably and easily used a polymer or oligomer having one or more polymerizable substituents and one or more metal complex structures in the molecule. Since a high-quality phosphorescent thin film can be formed, the present inventors have found that the polymer or oligomer is suitable for a material for organic electronics and have completed the present invention.

  That is, the present invention relates to a material for organic electronics comprising a polymer or oligomer having one or more polymerizable substituents and one or more metal complex structural units in the molecule.

  The central metal of the metal complex structural unit possessed by the polymer or oligomer is preferably Ir or Pt.

  The polymer or oligomer contained in the organic electronics material of the present invention preferably has a polydispersity of greater than 1.0 and a number average molecular weight of 1,000 or more and 100,000 or less. preferable.

  Examples of the polymerizable substituent that the polymer or oligomer has include an oxetane group, an epoxy group, a vinyl group, an acrylate group, and a methacrylate group.

（式中、Ｒ、Ｒｘ、Ｒｙ、Ｒｚ、Ｒｖ、およびＲｗは、それぞれ独立に、−Ｒ^１、−ＯＲ^２、−ＳＲ^３、−ＯＣＯＲ^４、−ＣＯＯＲ^５、−ＳｉＲ^６Ｒ^７Ｒ^８、または下記一般式（９ａ）〜（１１ａ）いずれか

（式中、Ｒ^１〜Ｒ^１１は、それぞれ独立に、水素原子、炭素数１〜２２個の直鎖、環状もしくは分岐アルキル基、または炭素数２〜３０個のアリール基もしくはヘテロアリール基を表し、ａ、ｂ、およびｃは、それぞれ独立に、１以上の整数を表す。）を表す。ただし、複数のＲｘ、Ｒｙ、Ｒｚ、Ｒｖ、およびＲｗにおいて、それぞれの少なくとも１つは、水素原子以外の基である。ｘ、ｙ、およびｚは、それぞれ独立に、１〜４の整数である。） The polymer or oligomer preferably further has a structural unit represented by any of the following general formulas (1a) to (8a) or a carbazole structural unit.

(Wherein, R, Rx, Ry, Rz, Rv, and Rw are each ^{independently, -R 1, -OR 2, -SR} 3, -OCOR 4, -COOR 5, -SiR 6 R 7 R 8, Or any one of the following general formulas (9a) to (11a)

(In the formula, R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms. , A, b, and c each independently represents an integer of 1 or more. However, in the plurality of Rx, Ry, Rz, Rv, and Rw, at least one of each is a group other than a hydrogen atom. x, y, and z are each independently an integer of 1 to 4. )

（式中、ＭはＩｒまたはＰｔである。ＭがＩｒのとき、ｍ＝２、ｎ＝１であり、ＭがＰｔのとき、ｍ＝３、ｎ＝１、またはｍ＝１、ｎ＝１である。環Ａは置換基Ｒを有していても良い窒素原子を含む環状構造を表す。環Ｂは置換基Ｒを有していても良い炭素原子を含む環状構造を表す。Ｒは、それぞれ独立に、−Ｒ^１、−ＯＲ^２、−ＳＲ^３、−ＯＣＯＲ^４、−ＣＯＯＲ^５、−ＳｉＲ^６Ｒ^７Ｒ^８、または一般式（９ａ）〜（１１ａ）いずれか

（式中、Ｒ^１〜Ｒ^１１は、それぞれ独立に、水素原子、炭素数１〜２２個の直鎖、環状もしくは分岐アルキル基、または炭素数２〜３０個のアリール基もしくはヘテロアリール基を表し、ａ、ｂ、およびｃは、それぞれ独立に、１以上の整数を表す。）を表す。Ｘは、Ｒから、さらに１つの水素原子を除去した基を表す。Ａｒは、ポリマーまたはオリゴマーの主鎖の一部となる、一般式（１６ａ）〜（２１ａ）いずれか

（式中、Ｒは、一般式（１２ａ）〜（１５ａ）におけるＲと同じである。）で表される３価または４価の基を表す。） As a metal complex structural unit, the structure represented by either of the following general formula (12a)-(15a) is mentioned, for example.

(Wherein M is Ir or Pt. When M is Ir, m = 2, n = 1, and when M is Pt, m = 3, n = 1, or m = 1, n = 1. Ring A represents a cyclic structure containing a nitrogen atom which may have a substituent R. Ring B represents a cyclic structure containing a carbon atom which may have a substituent R. R is ^{independently, -R 1, -OR 2, -SR} 3, -OCOR 4, -COOR 5, either -SiR ⁶ R ⁷ R ⁸ or the general formula, (9a) ~ (11a)

(In the formula, R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms. , A, b, and c each independently represents an integer of 1 or more. X represents a group obtained by further removing one hydrogen atom from R. Ar is any one of the general formulas (16a) to (21a), which is a part of the main chain of the polymer or oligomer.

(Wherein R is the same as R in formulas (12a) to (15a)) and represents a trivalent or tetravalent group. )

  The material for organic electronics of the present invention may further contain a polymerization initiator.

  The present invention also relates to an organic electronics element produced using the above-mentioned organic electronics material, and more particularly to an organic electroluminescence element.

  The organic electroluminescent element is preferably formed by laminating at least an anode, a light emitting layer, and a cathode, and the light emitting layer is a layer formed using the organic electronics material.

  The polymer or oligomer contained in the material for organic electronics of the present invention has a polymerizable substituent, so that the solubility is changed by a polymerization reaction, and also has a metal complex structural unit, and thus exhibits high luminous efficiency. Therefore, the material for organic electronics of the present invention is a very useful material capable of forming a thin film that emits light with high quality and high efficiency stably and easily by a coating method. The material for organic electronics of the present invention is preferably used for improving the light emission efficiency, color purity, and productivity of an organic electronics element, particularly an organic EL element that forms a thin film by a coating method.

  The organic electronic material of the present invention includes a polymer or oligomer having one or more polymerizable substituents and one or more metal complex structures in the molecule. Hereinafter, the polymer or oligomer will be described in detail.

  In the present invention, the polymerizable substituent is a substituent capable of forming a bond between two or more molecules by causing a polymerization reaction, and details thereof will be described below.

  Examples of the polymerizable substituent include a group having a carbon-carbon multiple bond (for example, vinyl group, acetylene group, butenyl group, acrylic group, acrylate group, acrylamide group, methacryl group, methacrylate group, methacrylamide group, arene group, And allyl group, vinyl ether group, vinylamino group, furyl group, pyrrole group, thiophene group, silole group, etc.), a group having a small ring (for example, cyclopropyl group, cyclobutyl group, epoxy group, oxetane) Groups, diketene groups, episulfide groups, etc.), lactone groups, lactam groups, or groups containing siloxane derivatives. In addition to the above groups, combinations of groups capable of forming an ester bond or an amide bond can also be used. For example, a combination of an ester group and a hydroxyl group, an ester group and an amino group, or the like. The polymerizable substituent is particularly preferably a group having a small ring or a group having a carbon-carbon multiple bond from the viewpoint of reactivity, more preferably an oxetane group, an epoxy group, a vinyl group, an acrylate group, or a methacrylate group. An oxetane group is preferred and the most preferred.

  In addition, the polymerizable substituent may be introduced as a side chain of the polymer or oligomer, or may be introduced at the terminal, and may be introduced as a side chain or introduced into the terminal. In particular, when introduced at the terminal, the influence on the properties of the polymer or oligomer main chain is small, which is preferable.

  The central metal of the metal complex structure is preferably iridium or platinum. When used as an organic EL material, iridium having a high triplet emission efficiency is more preferable.

  In the polymer or oligomer used in the present invention, it is desirable to control the polydispersity in order to improve film forming stability. The polydispersity range is preferably greater than 1.0, more preferably 1.1 or more and 5.0 or less, and most preferably 1.2 or more and 3.0 or less. If the polydispersity is too small, aggregation tends to occur after film formation. The polydispersity of the polymer or oligomer is (weight average molecular weight / number average molecular weight). In the present invention, the weight average molecular weight and number average molecular weight of a polymer or oligomer are values when measured in terms of polystyrene using gel permeation chromatography.

  In addition, it is desirable to control the molecular weight of the polymer or oligomer used in the present invention in order to improve film formation stability. The range of the number average molecular weight is preferably 1,000 or more and 100,000 or less, and more preferably 1,000 or more and 10,000 or less. If the molecular weight is less than 1,000, film-forming stability tends to decrease. In addition, when the above-described polymerizable substituent is introduced, if the number average molecular weight is too large, the change in solubility is small even when a polymerization reaction is performed, and the lamination tends to be difficult. In addition, in this invention, the number average molecular weight of a polymer or an oligomer is a number average molecular weight when measured in polystyrene conversion using gel permeation chromatography.

  In addition to the metal complex structural unit, the polymer or oligomer used in the present invention usually has another structural unit that functions as a host material. In order to efficiently perform triplet light emission, it is desirable that other structural units have a high energy level in the triplet state. For this purpose, it is effective to limit the conjugate length of the polymer or oligomer.

  Therefore, the polymer or oligomer in the present invention is, as a structural unit for limiting the conjugation length, an m-phenylene group or a substituent other than a hydrogen atom in at least one ortho position of the bonding position with an adjacent structural unit. It preferably has a group containing an aromatic ring. Examples of such structural units include the following general formula.

（式中、Ｒ、Ｒｘ、およびＲｙは、それぞれ独立に、−Ｒ^１、−ＯＲ^２、−ＳＲ^３、−ＯＣＯＲ^４、−ＣＯＯＲ^５、−ＳｉＲ^６Ｒ^７Ｒ^８、または（９ａ）〜（１１ａ）いずれか

（ただし、Ｒ^１〜Ｒ^１１は、それぞれ独立に、水素原子、炭素数１〜２２個の直鎖、環状もしくは分岐アルキル基、または炭素数２〜３０個のアリール基もしくはヘテロアリール基を表し、ａ、ｂ、およびｃは、それぞれ独立に、１以上の整数を表す。）を表す。ただし、複数のＲｘおよびＲｙにおいて、それぞれの少なくとも１つは、水素原子以外の基である。ｘ、ｙ、およびｚは、それぞれ独立に、１〜４の整数である。）

(Wherein, R, Rx, and Ry are each ^{independently, -R 1, -OR 2, -SR} 3, -OCOR 4, -COOR 5, -SiR 6 R 7 R 8 or, (9a) ~ ( 11a) Either

(However, R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms, a, b, and c each independently represents an integer of 1 or more. However, in the plurality of Rx and Ry, at least one of each is a group other than a hydrogen atom. x, y, and z are each independently an integer of 1 to 4. )

  A group having a substituent other than a hydrogen atom in at least one or more of the ortho positions of the bonding positions connecting the aromatic rings in the group is also preferable as the structural unit. Examples of such structural units include the following general formula.

（式中、Ｒ、Ｒｚ、Ｒｖ、およびＲｗは、それぞれ独立に、−Ｒ^１、−ＯＲ^２、−ＳＲ^３、−ＯＣＯＲ^４、−ＣＯＯＲ^５、−ＳｉＲ^６Ｒ^７Ｒ^８、または（９ａ）〜（１１ａ）いずれか

（ただし、Ｒ^１〜Ｒ^１１は、それぞれ独立に、水素原子、炭素数１〜２２個の直鎖、環状もしくは分岐アルキル基、または炭素数２〜３０個のアリール基もしくはヘテロアリール基を表し、ａ、ｂ、およびｃは、それぞれ独立に、１以上の整数を表す。）を表す。ただし、複数のＲｚ、Ｒｖ、およびＲｗにおいて、それぞれの少なくとも１つは、水素原子以外の基である。）

(Wherein, R, Rz, Rv, and Rw are each ^{independently, -R 1, -OR 2, -SR} 3, -OCOR 4, -COOR 5, or ^{-SiR 6 R 7 R 8, (} 9a) ~ (11a)

(However, R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms, a, b, and c each independently represents an integer of 1 or more. However, in the plurality of Rz, Rv, and Rw, at least one of each is a group other than a hydrogen atom. )

  A carbazole group is also preferable as a triplet-emitting host material as a structural unit having a high triplet state energy level. Examples of such structural units include, for example, the following general formula.

（式中、Ｒは、それぞれ独立に、−Ｒ^１、−ＯＲ^２、−ＳＲ^３、−ＯＣＯＲ^４、−ＣＯＯＲ^５、−ＳｉＲ^６Ｒ^７Ｒ^８、または（９ａ）〜（１１ａ）いずれか

（ただし、Ｒ^１〜Ｒ^１１は、それぞれ独立に、水素原子、炭素数１〜２２個の直鎖、環状もしくは分岐アルキル基、または炭素数２〜３０個のアリール基もしくはヘテロアリール基を表し、ａ、ｂ、およびｃは、それぞれ独立に、１以上の整数を表す。）を表す。）

(In the formula, each R is independently -R ¹ , -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ , or (9a) to (11a).

(However, R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms, a, b, and c each independently represents an integer of 1 or more. )

が挙げられる。 The structure of the metal complex is, for example,

Is mentioned.

In the formula, M is Ir or Pt. When M is Ir, m = 2 and n = 1, and when M is Pt, m = 3, n = 1, or m = 1 and n = 1.
Ring A is a cyclic structure containing a nitrogen atom. Ring B is a cyclic structure containing a carbon atom. Ring A and ring B may each have a substituent R.
Ring A includes a structure such as pyridine, quinoline, imidazole, pyrazole, benzothiazole, benzoxazole, benzotriazole, oxazole or benzimidazole which may have a substituent R.
Ring B may have a substituent R, benzene, biphenyl, terphenyl, naphthalene, anthracene, tetracene, fluorene, phenanthrene, chrysene, pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole , Thiophene, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxiadiazole, benzothiadiazole, benzotriazole, benzothiophene, carbazole and the like.

R is each independently —R ¹ , —OR ² , —SR ³ , —OCOR ⁴ , —COOR ⁵ , —SiR ⁶ R ⁷ R ⁸ , or any one of the general formulas (9a) to (11a) (provided that R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms, a, b And c each independently represents an integer of 1 or more.

Ｒは、一般式（１２ａ）〜（１５ａ）におけるＲと同じである。 X represents a group obtained by further removing one hydrogen atom from R.
Ar represents a trivalent or tetravalent group represented by any one of the general formulas (16a) to (21a), which is part of the main chain of the polymer or oligomer.

R is the same as R in the general formulas (12a) to (15a).

  The metal complex used as the structural unit of the polymer or oligomer used in the present invention can be produced by various synthetic methods known to those skilled in the art. For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. 2001.123. Can be used.

  As an example, a synthesis scheme of an Ir complex is described below. Other metal complexes can be obtained by the same method.

(Synthesis scheme of Ir complex)

Below, the example of the substituent which the metal complex structural unit in this invention and another structural unit have is given.
Examples of -R ¹ include a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, cyclopropyl group, butyl group, isobutyl group, tert-butyl group, cyclobutyl group, pentyl group, isopentyl group, neopentyl group, Cyclopentyl group, hexyl group, cyclohexyl group, heptyl group, cycloheptyl group, octyl group, nonyl group, decyl group, phenyl group, naphthyl group, anthryl group, fluorenyl group, furan residue, thiophene residue, pyrrole residue, oxazole Residues, thiazole residues, imidazole residues, pyridine residues, pyrimidine residues, pyrazine residues, triazine residues, quinoline residues, quinoxaline residues can be mentioned.
Examples of —OR ² are hydroxyl group, methoxy group, ethoxy group, propoxy group, butoxy group, tert-butoxy group, octyloxy group, tert-octyloxy group, phenoxy group, 4-tert-butylphenoxy group, 1- Examples thereof include a naphthyloxy group, a 2-naphthyloxy group, and a 9-anthryloxy group.
Examples of —SR ³ include a mercapto group, a methylthio group, an ethylthio group, a tert-butylthio group, a hexylthio group, an octylthio group, a phenylthio group, a 2-methylphenylthio group, and a 4-tert-butylphenylthio group. it can.
Examples of —OCOR ⁴ include a formyloxy group, an acetoxy group, and a benzoyloxy group.
Examples of —COOR ⁵ include a carboxyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a tert-butoxycarbonyl group, a phenoxycarbonyl group, and a naphthyloxycarbonyl group.
Examples of —SiR ⁶ R ⁷ R ⁸ include a silyl group, a trimethylsilyl group, a triethylsilyl group, a triphenylsilyl group, and the like.
Here, R ^{1 to} R ¹⁰ may have a substituent, and examples of the substituent include a halogen atom, a cyano group, an aldehyde group, an amino group, an alkyl group, an alkoxy group, an alkylthio group, a carboxyl group, and a sulfone. An acid group, a nitro group, etc. can be mentioned. These substituents may be further substituted with a halogen atom, a methyl group or the like.
In the present invention, a, b, and c in (9a) to (11a) are preferably integers of 1 to 4.

  Next, the polymer or oligomer used in the present invention can be produced by various synthetic methods known to those skilled in the art. For example, in the case of producing a polymer or oligomer in which each monomer unit constituting the polymer or oligomer has an aromatic ring and the aromatic rings are bonded to each other, T. Yamamoto et al., Bull. Chem. Soc. Jap. 51, No. 7, p. 2091 (1978) and M. Zembayashi et al., Tet. Lett. 47, page 4089 (1977). In particular, Suzuki (A. Suzuki), Synthetic Communications, Vol. 11, no. 7, p. The method reported in 513 (1981) is common for the production of polymers or oligomers. This reaction causes a Pd-catalyzed cross-coupling reaction (usually called “Suzuki reaction”) between an aromatic boronic acid derivative and an aromatic halide, and the corresponding aromatic ring By using for the reaction which couple | bonds (monomer), the polymer or oligomer used by this invention can be manufactured.

This reaction also requires soluble Pd compounds in the form of Pd (II) salts or Pd (0) complexes. Pd (OAc) ₂ and PdCl ₂ (dppf) complexes with 0.01-5 mol% Pd (Ph ₃ P) ₄ , tertiary phosphine ligands are generally preferred based on the aromatic ring (monomer) used in the reaction Pd source. This reaction also requires a base, with aqueous alkaline carbonate or bicarbonate being most preferred. The reaction can also be promoted in a nonpolar solvent using a phase transfer catalyst. As the solvent, N, N-dimethylformamide, toluene, anisole, dimethoxyethane, tetrahydrofuran or the like is used.

  The content ratio of the metal complex structural unit in the polymer or oligomer is preferably 1 to 30 mol% with respect to the entire structural unit constituting the polymer or oligomer. If it is less than 1 mol%, the energy of the host material cannot be efficiently transferred to the metal complex, the emission of the host material increases, and the color purity of the emission tends to decrease. On the other hand, if it exceeds 30 mol%, a large amount of expensive metal complex structural units are required, and the cost tends to increase. More preferably, it is 2-20 mol%, More preferably, it is 3-15 mol%.

  Moreover, in order to improve hole transport property and improve luminous efficiency, it is preferable to contain 10-99 mol% of carbazole groups with respect to the whole structural unit which comprises a polymer or an oligomer. More preferably, it is 20-80 mol%, More preferably, it is 25-75 mol%, Most preferably, it is 25-50 mol%.

  In addition to the polymer or oligomer, the organic electronics material of the present invention may further contain a polymerization initiator. The polymerization initiator is preferably one that expresses the ability to polymerize a polymerizable substituent by application of heat, light, microwave, radiation, electron beam, and the like, and is not particularly limited. It is preferable that the polymerization is initiated by, and more preferable is a polymerization initiator that initiates polymerization by light irradiation (hereinafter referred to as a photoinitiator). As the photoinitiator, those that exhibit the ability to polymerize a substituent capable of being polymerized by irradiation with light of 200 to 800 nm are preferable, and are not particularly limited. For example, when the polymerizable substituent is an oxetane group, iodonium salts, sulfonium salts, and ferrocene derivatives are preferable from the viewpoint of reactivity, and the following compounds are exemplified.

（Ｒは、それぞれ独立に、一般式（１ａ）〜（８ａ）におけるＲと同じである。）

(R is independently the same as R in formulas (1a) to (8a).)

  The photoinitiator may be used in combination with a photosensitizer in order to improve photosensitivity. Examples of the photosensitizer include anthracene derivatives and thioxanthone derivatives.

  The blending ratio of the polymerization initiator is preferably in the range of 0.1% by weight to 10% by weight and in the range of 0.2% by weight to 8% by weight with respect to the total weight of the organic electronics material. More preferably, it is particularly preferably in the range of 0.5 wt% to 5 wt%. When the blending ratio of the polymerization initiator is less than 0.1% by weight, stacking tends to be difficult, and when it exceeds 10% by weight, device characteristics tend to deteriorate.

  In addition to the polymer or oligomer, a carbon material such as carbon nanotube or fullerene can be further blended with the organic electronics material of the present invention in order to adjust electrical characteristics.

  In order to form various layers used for an organic electronics element or the like using the organic electronics material of the present invention, for example, there are the following methods. The solution containing the material for organic electronics of the present invention is, for example, an inkjet method, a casting method, a dipping method, a relief printing, an intaglio printing, an offset printing, a flat plate printing, a relief printing, an offset printing, a screen printing, a gravure printing or the like, After coating on a desired substrate by a known method such as spin coating, a polymer or oligomer polymerization reaction is advanced by light irradiation, heat treatment or the like to cure the coating layer. By repeating such an operation, it becomes possible to increase the number of organic electronics elements and organic EL elements using a coating method.

  The coating method as described above can be usually carried out at a temperature range of -20 to + 300 ° C, preferably 10 to 100 ° C, particularly preferably 15 to 50 ° C. Although not particularly limited, examples thereof include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene, mesitylene, anisole, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, and ethyl cellosolve acetate.

  In addition, a light source such as a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a fluorescent lamp, a light emitting diode, or sunlight can be used for the light irradiation. Moreover, the said heat processing can be performed on a hotplate or in oven, and can be implemented at the temperature range of 0- + 300 degreeC, Preferably it is 20-250 degreeC, Most preferably, it is 80-200 degreeC.

  The material for organic electronics of the present invention can be used alone as a functional material of an organic electronics element. Moreover, the organic electronics material of the present invention is used alone as a hole injection layer, a hole transport layer, an electron block layer, a light emitting layer, a hole block layer, an electron transport layer, and an electron injection layer of an organic EL element. It is most preferable to use as a light emitting layer.

  The organic electronics element and the organic EL element of the present invention may be provided with a layer containing the organic electronics material of the present invention, and the structure thereof is not particularly limited. The general structure of organic EL is disclosed in, for example, US Pat. No. 4,539,507, US Pat. No. 5,151,629, etc., and polymer-containing organic EL elements Is disclosed in, for example, International Publication No. 90/13148 and European Patent Publication No. 0438486. These usually have a structure including an electroluminescent layer (light emitting layer) between a cathode (cathode) at least one of which is transparent and an anode (anode). Furthermore, a structure in which one or more electron injection layers and / or electron transport layers are inserted between the electroluminescent layer (light emitting layer) and the cathode, one or more hole injection layers and / or hole transport In some structures, the layer is inserted between the electroluminescent layer (light emitting layer) and the anode.

  The cathode material is preferably a metal or metal alloy such as Li, Ca, Mg, Al, In, Cs, Ba, Mg / Ag, LiF, and CsF. As an anode, a metal (eg, Au) or other material having metal conductivity formed on a transparent substrate (eg, glass or transparent polymer), eg, an oxide (eg, ITO: indium oxide / tin oxide) Can be used.

  As described above, the organic electronics material of the present invention can be used as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like of an organic EL element. Most preferably, it is used. The thickness of these layers is not particularly limited, but is preferably 5 to 100 nm, more preferably 10 to 80 nm, and still more preferably 20 to 60 nm.

  The invention is illustrated by the following examples without however being limited thereto.

丸底フラスコに、３−エチル−３−ヒドロキシメチルオキセタン（５０ｍｍｏｌ）、４−ブロモベンジルブロミド（５０ｍｍｏｌ）、ｎ−ヘキサン（２００ｍＬ）、テトラブチルアンモニウムブロミド（２．５ｍｍｏｌ）、及び５０重量％水酸化ナトリウム水溶液（３６ｇ）を加え、窒素雰囲気下、７０℃で６時間加熱撹拌した。室温（２５℃）まで冷却後、水２００ｍＬを加え、生成物をｎ−ヘキサンで抽出した。溶媒留去後、シリカゲルカラムクロマトグラフィーと減圧蒸留によって精製し、重合可能な置換基を有するモノマーＡを無色油状物として９．５１ｇ得た。収率６７重量％。
^１Ｈ−ＮＭＲ（３００ＭＨｚ，ＣＤＣｌ_３，δｐｐｍ）；０．８６（ｔ，Ｊ＝７．５Ｈｚ，３Ｈ），１．７６（ｑ，Ｊ＝７．５Ｈｚ，２Ｈ），３．５７（ｓ，２Ｈ），４．３９（ｄ，Ｊ＝５．７Ｈｚ，２Ｈ），４．４５（ｄ，Ｊ＝５．７Ｈｚ，２Ｈ），４．５１（ｓ，２Ｈ），７．２２（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ），７．４７（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ）。 Example 1
<Synthesis of Monomer (Oxetane Monomer) A with Polymerizable Substituent>

In a round bottom flask, 3-ethyl-3-hydroxymethyloxetane (50 mmol), 4-bromobenzyl bromide (50 mmol), n-hexane (200 mL), tetrabutylammonium bromide (2.5 mmol), and 50 wt% hydroxylation. A sodium aqueous solution (36 g) was added, and the mixture was heated and stirred at 70 ° C. for 6 hours under a nitrogen atmosphere. After cooling to room temperature (25 ° C.), 200 mL of water was added, and the product was extracted with n-hexane. After the solvent was distilled off, the residue was purified by silica gel column chromatography and reduced pressure distillation to obtain 9.51 g of monomer A having a polymerizable substituent as a colorless oil. Yield 67% by weight.
¹ H-NMR (300 MHz, CDCl ₃ , δ ppm); 0.86 (t, J = 7.5 Hz, 3H), 1.76 (q, J = 7.5 Hz, 2H), 3.57 (s, 2H) ), 4.39 (d, J = 5.7 Hz, 2H), 4.45 (d, J = 5.7 Hz, 2H), 4.51 (s, 2H), 7.22 (d, J = 8) .4 Hz, 2H), 7.47 (d, J = 8.4 Hz, 2H).

ジ（μ−クロロ）テトラキス（２−（２−ピリジル）ベンゾチエニル）ジイリジウム［（Ｉｒ（ｂｔｐ）_２Ｃｌ）_２］ １．０ｇ（０．７５ｍｍｏｌ）、３−（２，５−ジブロモ−ベンジル）−ペンタン−２，４−ジオン ０．６６ｇ（１．９ｍｍｏｌ）、炭酸ナトリウム １．０ｇ（７．５ｍｍｏｌ）、及び脱水ＤＭＦ ３３ｍｌを１００ｍＬナス型フラスコに入れ、窒素でバブリングしながら、室温で５日間撹拌した。反応溶液に酢酸エチルを加え、水洗を繰返しＤＭＦを除去した。溶媒を留去し、アルミナカラムクロマトグラフィーを用いて精製を行い、Ｉｒ錯体Ａを０．６１ｇ得た。収率４２％。
^１Ｈ−ＮＭＲ（３００ＭＨｚ，ＣＤＣｌ_３，δｐｐｍ）；１．７４（ｓ，６Ｈ），３．６８（ｓ，２Ｈ），６．２４（ｄ，Ｊ＝７．８Ｈｚ，２Ｈ）、６．８２（ｔ，Ｊ＝７．２Ｈｚ，２Ｈ）、７．０４−７．６８（ｍ，１１Ｈ）、７．８１（ｔ，Ｊ＝７．５Ｈｚ，２Ｈ）、８．５１（ｄ，Ｊ＝５．７Ｈｚ，２Ｈ）。
ＭＳ（Ｃ_３８Ｈ_２７Ｂｒ_２ＩｒＮ_２Ｏ_２Ｓ_２；Ｍｏｌ．Ｗｔ．：９５９．７９）実測値９５９．９。 <Synthesis of Ir complex A>

Di (μ-chloro) tetrakis (2- (2-pyridyl) benzothienyl) diiridium [(Ir (btp) ₂ Cl) ₂ ] 1.0 g (0.75 mmol), 3- (2,5-dibromo-benzyl ) -Pentane-2,4-dione (0.66 g, 1.9 mmol), sodium carbonate (1.0 g, 7.5 mmol), and dehydrated DMF (33 ml) were placed in a 100 mL eggplant-shaped flask and stirred at room temperature for 5 hours while bubbling with nitrogen. Stir for days. Ethyl acetate was added to the reaction solution, and washing with water was repeated to remove DMF. The solvent was distilled off and purification was performed using alumina column chromatography to obtain 0.61 g of Ir complex A. Yield 42%.
¹ H-NMR (300 MHz, CDCl ₃ , δ ppm); 1.74 (s, 6H), 3.68 (s, 2H), 6.24 (d, J = 7.8 Hz, 2H), 6.82 ( t, J = 7.2 Hz, 2H), 7.04-7.68 (m, 11H), 7.81 (t, J = 7.5 Hz, 2H), 8.51 (d, J = 5.7 Hz) , 2H).
_{MS (C 38 H 27 Br 2} IrN 2 O 2 S 2; Mol.Wt.: 959.79) Found 959.9.

<Synthesis of oligomer A>

  In a glove box, tris (dibenzylideneacetone) dipalladium (0) (25 mmol), t-butylphosphine (200 mmol), and anisole (6.25 mL) were mixed to prepare a Pd catalyst solution. In a sealable fluororesin container, 1,4-bis (pinacolborolane) -2,5-bis-hexyloxy-benzene (0.4 mmol), N-phenyl-3,6-dibromocarbazole (0.26 mmol), Ir complex A (0.06 mmol), monomer A having a polymerizable substituent (0.16 mmol), anisole (3 ml), 10% tetraethylammonium hydroxide aqueous solution (8 mL), and the Pd catalyst solution (1 mL) were added. And sealed in a nitrogen atmosphere. The sealed container was irradiated with microwaves, and stirred at 90 ° C. for 1 hour. The reaction solution was extracted, washed with water, poured into a methanol / water mixed solvent (9: 1), and the precipitated oligomer was filtered off. The reprecipitation was repeated three times for purification, and 0.12 g of oligomer A having a polymerizable substituent and a repeating unit having a metal complex and a repeating unit having a carbazole group was obtained. The number average molecular weight of the obtained oligomer A was 3004 in terms of polystyrene, and the polydispersity was 1.44.

<Preparation of thin film>
(Example 2)
A coating solution in which oligomer A (5 mg) and anisole (1 ml) were mixed was spin-coated on a quartz substrate at 2000 rpm, and then heated and dried on a hot plate at 80 ° C. for 15 minutes. When this glass substrate was irradiated with light of 365 nm, uniform red light emission was obtained. When this quartz substrate was excited with 365 nm light using a spectrofluorometer, a spectrum having a maximum absorption wavelength at 619 nm was obtained.

(Comparative Example 1)
A coating solution in which CBP (5 mg), Ir (btp) ₂ (acac) (0.15 mg), and anisole (1 ml) were mixed was spin-coated on a quartz substrate at 2000 rpm, and then on a hot plate at 80 ° C., 15 Heated for minutes to dry. When this quartz substrate was irradiated with 365 nm light, there was uneven color and uniform light emission could not be obtained.

で表される光開始剤（０．１３ｍｇ）、及びアニソール（１．２ｍｌ）を混合した塗布溶液を、３０００ｒｐｍで石英基板にスピンコートした後、メタルハライドランプを用いて光照射（３Ｊ／ｃｍ^２）し、ホットプレート上で１８０℃、６０分間加熱して硬化させた。この層の膜厚を触針式段差計（ＡＭＢＩＯＳ社製ＸＰ−２）で測定したところ、３２ｎｍであった。この石英基板をシャーレに移し、３０秒間アニソール中に浸した。石英基板を取り出し、ホットプレート上で８０℃、１５分間加熱して乾燥させたのち、再び膜厚を測定したところ、２７ｎｍであった。 <Evaluation of solubility of thin film>
(Example 3)
Oligomer A (4.4 mg), the following chemical formula

A coating solution in which a photoinitiator represented by the formula (0.13 mg) and anisole (1.2 ml) are mixed is spin-coated on a quartz substrate at 3000 rpm, and then irradiated with light using a metal halide lamp (3 J / cm ² ). Then, it was cured by heating at 180 ° C. for 60 minutes on a hot plate. It was 32 nm when the film thickness of this layer was measured with the stylus type level difference meter (XP-2 by AMBIOS). This quartz substrate was transferred to a petri dish and immersed in anisole for 30 seconds. The quartz substrate was taken out, heated on a hot plate at 80 ° C. for 15 minutes and dried, and the film thickness was measured again to be 27 nm.

(Comparative Example 3)
In the synthesis of the oligomer A of Example 1, an oligomer B having no polymerizable substituent was synthesized in the same manner except that the monomer A having a polymerizable substituent was changed to bromobenzene. The number average molecular weight of the obtained oligomer B was 4092 in terms of polystyrene, and the polydispersity was 1.51. When this oligomer B was used to produce a thin film in the same manner as in Example 3, the film thickness was 39 nm. This quartz substrate was transferred to a petri dish and immersed in anisole for 30 seconds. When the quartz substrate was taken out, the thin film was dissolved.
Oligomer B is shown below.

  Since the organic electronics material of the present invention can form a thin film stably and easily by a coating method and emits light with high efficiency, the organic electronics element, particularly the organic EL element that forms a thin film by a coating method, This material is extremely useful for improving color purity and productivity.

It is sectional drawing which shows an example of the multilayered organic EL element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cathode 2 Electron injection layer 3 Electron transport layer 4 Light emitting layer 5 Hole transport layer 6 Hole injection layer 7 Anode 8 Substrate

Claims (11)

  An organic electronic material comprising a polymer or oligomer having one or more polymerizable substituents and one or more metal complex structural units in a molecule.   The material for organic electronics according to claim 1, wherein the central metal of the metal complex structural unit is Ir or Pt.   The organic electronic material according to claim 1 or 2, wherein the polydispersity of the polymer or oligomer is greater than 1.0.   The material for organic electronics according to any one of claims 1 to 3, wherein the number average molecular weight of the polymer or oligomer is 1,000 or more and 100,000 or less.   The organic electronics material according to any one of claims 1 to 4, wherein the polymerizable substituent is an oxetane group, an epoxy group, a vinyl group, an acrylate group, or a methacrylate group. The material for organic electronics according to any one of claims 1 to 5, wherein the polymer or oligomer has a structural unit represented by any of the following general formulas (1a) to (8a) or a carbazole structural unit.

(Wherein, R, Rx, Ry, Rz, Rv, and Rw are each ^{independently, -R 1, -OR 2, -SR} 3, -OCOR 4, -COOR 5, -SiR 6 R 7 R 8, Or any one of the following general formulas (9a) to (11a)

(In the formula, R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms. , A, b, and c each independently represents an integer of 1 or more. However, in the plurality of Rx, Ry, Rz, Rv, and Rw, at least one of each is a group other than a hydrogen atom. x, y, and z are each independently an integer of 1 to 4. ) The organic electronics material according to any one of claims 2 to 6, wherein the metal complex structural unit is represented by any one of the following general formulas (12a) to (15a).

(Wherein M is Ir or Pt. When M is Ir, m = 2, n = 1, and when M is Pt, m = 3, n = 1, or m = 1, n = 1. Ring A represents a cyclic structure containing a nitrogen atom which may have a substituent R. Ring B represents a cyclic structure containing a carbon atom which may have a substituent R. R is ^{independently, -R 1, -OR 2, -SR} 3, -OCOR 4, -COOR 5, either -SiR ⁶ R ⁷ R ⁸ or the general formula, (9a) ~ (11a)

(In the formula, R ^{1 to} R ¹¹ each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms. , A, b, and c each independently represents an integer of 1 or more. X represents a group obtained by further removing one hydrogen atom from R. Ar is any one of the general formulas (16a) to (21a), which is a part of the main chain of the polymer or oligomer.

(Wherein R is the same as R in formulas (12a) to (15a)) and represents a trivalent or tetravalent group. )   Furthermore, the material for organic electronics in any one of Claims 1-7 containing a polymerization initiator.   The organic electronics element produced using the organic electronics material in any one of Claims 1-8.   The organic electroluminescent element produced using the material for organic electronics in any one of Claims 1-8.   An organic electroluminescence device comprising at least an anode, a light emitting layer and a cathode, wherein the light emitting layer is a layer formed using the organic electronics material according to claim 1. Electroluminescence element.

Images