JP5555977B2 - Material for organic electronics, and organic electronics element and organic electroluminescence element using the same - Google Patents

Description

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

  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 of an organic compound is sandwiched between a cathode and an anode, and the method of forming the thin film is roughly classified into a vapor deposition method and a coating method. The vapor deposition method is a method of forming a thin film on a substrate in a vacuum mainly using a low molecular compound, and commercialization has preceded. On the other hand, the coating method is a method of forming a thin film on a substrate using a solution such as ink jet or printing, which is highly efficient in using materials, is suitable for large area and high definition. This is an indispensable technique for EL displays. However, organic EL elements using either method still have great problems, despite their intensive research, low light emission efficiency and short element life. As one means for solving this problem, organic EL elements are multilayered by vapor deposition.

  FIG. 1 shows an example of a multilayered organic EL element. In FIG. 1, the layer responsible for light emission is described as the light emitting layer 1, and the layer in contact with the anode 2 is described as the hole injection layer 3, and the layer in contact with the cathode 4 is described as the electron injection layer 5. Further, when a different layer exists between the light emitting layer 1 and the hole injection layer 3, it is described as a hole transport layer 6, and when a different layer exists between the light emitting layer 1 and the electron injection layer 5, the electron transport It is described as layer 7. In FIG. 1, 8 is a substrate.

  Here, when forming a film by a vapor deposition method, multilayering can be easily achieved by performing vapor deposition while sequentially changing the compound to be used. On the other hand, when a film is formed or multilayered by a coating method, a method is required in which the already formed layer does not change when a new layer is formed. Therefore, many organic EL devices by the coating method use a hole injection layer made of polythiophene: polystyrenesulfonic acid (PEDOT: PSS), which is formed using an aqueous dispersion, and an aromatic organic solvent such as toluene. It has a two-layer structure of a light emitting layer for film formation. In this case, since the PEDOT: PSS layer is not dissolved in toluene, a two-layer structure can be produced.

  The reason why it is difficult to further increase the number of layers in the organic EL device by the coating method is that the lower layer dissolves when lamination is performed with a similar solvent. In order to cope with this problem, a technique is known in which a low molecular compound having a polymerizable substituent is applied and then 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.

  In other words, in order to solve the problems of the current organic EL elements, a high-quality thin film (organic layer) is formed by a coating method that allows easy film formation even in a large area, and the functions of each layer are separated by multilayering. is important.

  By the way, in recent years, phosphorescent organic EL elements have been actively developed in order to increase the efficiency of organic EL elements. In this 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.

  Further, in a 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 phosphorescent dopant (for example, Non-Patent Document 2, Non-Patent Document 2). Reference 3 and Non-Patent Document 4). The emission of this phosphorescent dopant has a dependence on the host material. Examples of basic performance required for the host material include a hole transport property and an electron transport property, and a host material having a high triplet state energy level. Generally, CBP (4,4′-Bis A carbazole derivative such as (Carbazol-9-yl) -biphenyl) is preferably used (for example, see Patent Document 2). However, a charge transport material such as CBP is easily crystallized, and film formation by a coating method is difficult.

JP 2006-279007 A JP 2003-068466 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 view of the above problems, an object of the present invention is to provide a material for organic electronics that can be easily multilayered and can form a high-quality thin film.
Another object of the present invention is to provide an organic electronics element and an organic EL element which are more efficient and have a longer life than those of the conventional materials using the organic electronics material of the present invention.

（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又は下記一般式（１５ａ）〜（１７ａ）

（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、環状若しくは分岐アルキル基、又は炭素数２〜３０個のアリール基若しくはヘテロアリール基を表し、ａ、ｂ及びｃは、１以上の整数を表す。）を表し、Ｘ及びＹは、それぞれ独立に、前記Ｒのうち、水素原子を１つ以上有する基から、さらに１つの水素原子を除去した基を表し、Ｚは、前記Ｒのうち、水素原子を２つ以上有する基から、さらに２つの水素原子を除去した基を表し、Ａｒは、置換又は非置換のアリーレン基及び／又はヘテロアリーレン基を表し、Ｅは、重合可能な置換基を含む基を表し、ｘは、０又は１の整数であり、ｎは、２以上の整数である。）
前記一般式（１ａ）〜（１４ａ）において、好ましくは、ｎの数平均が２〜２０である。
さらに、本発明の有機エレクトロニクス用材料は、イリジウム錯体又は白金錯体を含んでいてもよい。
また、さらに、本発明の有機エレクトロニクス用材料は、重合開始剤を含んでいてもよい。
また、本発明は、上記の有機エレクトロニクス用材料を用いて作製された有機エレクトロニクス素子、または、上記の有機エレクトロニクス用材料を用いて作製された有機エレクトロルミネセンス素子に関する。
本発明の有機エレクトロルミネセンス素子の態様として、例えば、少なくとも陽極、発光層及び陰極が積層されてなる有機エレクトロルミネセンス素子であって、前記発光層が上記の有機エレクトロニクス用材料により形成された層である有機エレクトロルミネセンス素子；少なくとも陽極、正孔輸送層、発光層及び陰極が積層されてなる有機エレクトロルミネセンス素子であって、前記正孔輸送層が上記の有機エレクトロニクス用材料により形成された層である有機エレクトロルミネセンス素子；少なくとも陽極、正孔注入層、発光層及び陰極が積層されてなる有機エレクトロルミネセンス素子であって、前記正孔注入層が上記の有機エレクトロニクス用材料により形成された層である有機エレクトロルミネセンス素子などがある。 As a result of intensive studies, the present inventors have stably and easily formed a high-quality thin film using a polymer or oligomer having one or more polymerizable substituents and a repeating unit having carbazole. In addition, the present inventors have found that the solubility is changed by a polymerization reaction, and further found that this material is useful as a material for organic electronics, thereby completing the present invention.
That is, this invention relates to the material for organic electronics containing the polymer or oligomer which has a repeating unit which has a 1 or more polymerizable substituent and has a carbazole group.
Examples of the polymerizable substituent include oxetane group, epoxy group, vinyl group, acryloyloxy group, and methacryloyloxy group. In one embodiment of the present invention, the polymer or oligomer has the polymerizable substituent at the end.
The number average molecular weight of the polymer or oligomer is preferably 1,000 or more and 100,000 or less, and the polydispersity of the polymer or oligomer is preferably larger than 1.0.
Examples of the polymer or oligomer include polymers or oligomers having a structure represented by the following general formulas (1a) to (14a).

(Wherein, R, ^-R 1 each ^{independently, -OR 2, -SR 3, -OCOR} 4, -COOR 5, -SiR 6 R 7 R 8 or the following general formula (15a) ~ (17a)

(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 represent an integer of 1 or more.) X and Y each independently removed one hydrogen atom from a group having one or more hydrogen atoms out of the R. Z represents a group obtained by removing two hydrogen atoms from a group having two or more hydrogen atoms out of R, and Ar represents a substituted or unsubstituted arylene group and / or heteroarylene group. E represents a group containing a polymerizable substituent, x is an integer of 0 or 1, and n is an integer of 2 or more. )
In the general formulas (1a) to (14a), the number average of n is preferably 2 to 20.
Furthermore, the material for organic electronics of the present invention may contain an iridium complex or a platinum complex.
Furthermore, the organic electronics material of the present invention may contain a polymerization initiator.
The present invention also relates to an organic electronics element produced using the organic electronics material or an organic electroluminescence element produced using the organic electronics material.
As an aspect of the organic electroluminescent element of the present invention, for example, an organic electroluminescent element in which at least an anode, a light emitting layer and a cathode are laminated, wherein the light emitting layer is formed of the above-mentioned organic electronics material. An organic electroluminescence device comprising at least an anode, a hole transport layer, a light emitting layer, and a cathode, wherein the hole transport layer is formed of the material for organic electronics. An organic electroluminescent device comprising at least an anode, a hole injection layer, a light emitting layer and a cathode, wherein the hole injection layer is formed of the above-mentioned organic electronics material. There is an organic electroluminescence element which is a layer.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the material for organic electronics which can be multilayered easily and can form a good-quality thin film, Organic electroluminescent element, especially organic EL formed by forming a thin film by the apply | coating method It is also possible to improve the light emission efficiency, the light emission lifetime, and the productivity of the element.

（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又はポリエーテルである下記一般式（１５ａ）〜（１７ａ）

（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、環状若しくは分岐アルキル基、又は炭素数２〜３０個のアリール基若しくはヘテロアリール基を表し、ａ、ｂ及びｃは、１以上の整数、好ましくは１〜４の整数を表す。）を表し、Ｘ及びＹは、それぞれ独立に、前記Ｒのうち、水素原子を１つ以上有する基から、さらに１つの水素原子を除去した基を表し、Ｚは、前記Ｒのうち、水素原子を２つ以上有する基から、さらに２つの水素原子を除去した基を表し、ｘは、０又は１の整数である。） The material for organic electronics of the present invention is characterized by comprising a polymer or oligomer having one or more polymerizable substituents in the molecule and a repeating unit having a carbazole group in the molecule. is there. Here, the “repeating unit having a carbazole group” is an atomic group having a carbazole group and is not particularly limited as long as it has a carbazole group. For example, the following general formulas (18a) to (24a) Is mentioned.

(In the formula, each R is independently -R ¹ , -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ or a polyether represented by the following general formulas (15a) to ( 17a)

(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 represent an integer of 1 or more, preferably an integer of 1 to 4, and X and Y are each independently a group having one or more hydrogen atoms among the R. Furthermore, Z represents a group from which one hydrogen atom has been removed, Z represents a group in which two hydrogen atoms have been further removed from a group having two or more hydrogen atoms in R, and x represents an integer of 0 or 1 It is. )

  The polymer or oligomer used in the present invention has one or more “polymerizable substituents”. Here, the “polymerizable substituent” means 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, acryloyl group, acryloyloxy group, acrylamide group, methacryloyl group, methacryloyloxy group, methacrylamide group , a Lil group, vinyloxy group, a vinyl amino group, a furyl group, a pyrrole group, a thiophene group, and a silole group), group (e.g., having a small ring, a cyclopropyl group, a cyclobutyl group, an epoxy group, oxetane Groups, diketene groups, episulfide groups, etc.), lactone groups, lactam groups or groups containing siloxane derivatives.

  In addition to the above groups, a combination of groups capable of forming an ester bond or an amide bond can be used as a polymerizable substituent. For example, a combination of an ester group and an amino group, an ester group and a hydroxyl group, or the like. As the polymerizable substituent, an oxetane group, an epoxy group, a vinyl group, an acryloyloxy group, and a methacryloyloxy group are particularly preferable from the viewpoint of reactivity, and an oxetane group is most preferable.

  In addition, the polymerizable substituent may be introduced as a side chain of the polymer or oligomer used in the present invention, may be introduced at the terminal, or may be introduced at both the side chain and 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.

  Hereinafter, the details when the polymerizable substituent is introduced at the terminal of the polymer or oligomer will be described.

（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又はポリエーテルである下記一般式（１５ａ）〜（１７ａ）

（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、環状若しくは分岐アルキル基、又は炭素数２〜３０個のアリール基若しくはヘテロアリール基を表し、ａ、ｂ及びｃは、１以上の整数、好ましくは１〜４の整数を表す。）を表し、Ｘ及びＹは、それぞれ独立に、前記Ｒのうち、水素原子を１つ以上有する基から、さらに１つの水素原子を除去した基を表し、Ｚは、前記Ｒのうち、水素原子を２つ以上有する基から、さらに２つの水素原子を除去した基を表し、Ａｒは、置換若しくは非置換のアリーレン基及び／又はヘテロアリーレン基を表し、Ｅは重合可能な置換基を含む基を表し、ｘは、０又は１の整数であり、ｎは、２以上の整数である。） Examples of the polymer or oligomer in the present invention when a polymerizable substituent is introduced at the terminal of the polymer or oligomer include the following general formulas (1a) to (14a).

(In the formula, each R is independently -R ¹ , -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ or a polyether represented by the following general formulas (15a) to ( 17a)

(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 represent an integer of 1 or more, preferably an integer of 1 to 4, and X and Y are each independently a group having one or more hydrogen atoms among the R. Furthermore, Z represents a group from which one hydrogen atom has been removed, Z represents a group in which two hydrogen atoms have been further removed from a group having two or more hydrogen atoms, and Ar represents a substituted or unsubstituted group. An arylene group and / or a heteroarylene group is represented, E represents a group containing a polymerizable substituent, x is an integer of 0 or 1, and n is an integer of 2 or more. )

  Ar in the general formulas (1a) to (14a) represents a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, or a group in which a substituted or unsubstituted arylene group and a heteroarylene group are combined. Here, the arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon, and the heteroarylene group is an atom obtained by removing two hydrogen atoms from an aromatic compound having a hetero atom. A group. The arylene group and heteroarylene group may be substituted or unsubstituted. As a substituent which an arylene group and heteroarylene group have, the substituent R in the said General formula (1a)-(14a) is mentioned, for example.

  Examples of the arylene group include phenylene, biphenyl-diyl, terphenyl-diyl, naphthalene-diyl, anthracene-diyl, tetracene-diyl, fluorene-diyl, phenanthrene-diyl, and examples of the heteroarylene group include Pyridine-diyl, pyrazine-diyl, quinoline-diyl, isoquinoline-diyl, acridine-diyl, phenanthroline-diyl, furan-diyl, pyrrole-diyl, thiophene-diyl, oxazole-diyl, oxadiazole-diyl, thiadiazole-diyl, Examples include triazole-diyl, benzoxazole-diyl, benzooxadiazole-diyl, benzothiadiazole-diyl, benzotriazole-diyl, and benzothiophene-diyl.

（上記構造式（１）〜（３０）中、Ｒは、上記一般式（１ａ）〜（１４ａ）、（１８ａ）〜（２４ａ）における置換基Ｒと同様であり、構造式（２９）、（３０）におけるｌ、ｍ、ｎは、１〜５の整数であり、２〜４の整数であることが好ましい。） Examples of the arylene group and / or heteroarylene group which may be substituted or unsubstituted are shown in the following structural formulas (1) to (30).

(In the structural formulas (1) to (30), R is the same as the substituent R in the general formulas (1a) to (14a) and (18a) to (24a). 30) l, m and n are integers of 1 to 5, preferably 2 to 4.

  In the above general formulas (1a) to (14a), Ar represents the above structural formula (29) having a phenylene group, a fluorene-diyl group, a phenanthrene-diyl group, or a condensed ring structure from the viewpoints of solubility and chemical stability. Or (30) is preferable. In addition, when the organic electronics material of the present invention is used in the light emitting layer of a phosphorescent organic EL device, it is desirable that the band gap be large in order to efficiently cause energy transfer to the phosphorescent dopant. The structural formula (29) or (30) having a polycyclic structure is preferable.

The substituent R in the general formulas (1a) to (14a), (18a) to (24a) and the structural formulas (1) to (30) is an unsubstituted one, that is, a hydrogen atom. Or an alkyl group represented by —R ¹ , an aryl group, a heteroaryl group, a hydroxyl group represented by —OR ² , an alkoxy group, an aryloxy group, or a heteroaryloxy group from the viewpoint of polymerization reactivity and heat resistance. preferable.

また、上記一般式（１ａ）〜（１４ａ）、（１８ａ）〜（２４ａ）のＺは、前記置換基Ｒ（好ましくは−Ｒ^１）のうち、水素原子を２つ以上有する基から、さらに２つの水素原子を除去した基を表し、例えば、下記構造式（３６）、（３７）が挙げられる。Ｚは、置換基を有していてもよい。

In the general formulas (1a) to (14a) and (18a) to (24a), X and Y each independently represent one or more hydrogen atoms in the substituent R (preferably -R ¹ ). A group obtained by further removing one hydrogen atom from the group to be represented is not particularly limited, and examples thereof include the following structural formulas (31) to (35). X and Y may have a substituent.

Z in the above general formulas (1a) to (14a) and (18a) to (24a) is further represented by 2 from the group having two or more hydrogen atoms in the substituent R (preferably -R ¹ ). It represents a group from which two hydrogen atoms have been removed, and examples include the following structural formulas (36) and (37). Z may have a substituent.

E in the above general formulas (1a) to (14a) is, for example, the above-described polymerizable substituent in an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, a carbazole group, or a group formed by combining these. Is a group in which one or more are bonded. E may be the same or different. As an aryl group and heteroaryl group, the group similar to Ar in the said General formula (1a)-(14a) is mentioned, for example. E is preferably an oxetane group-containing group, and examples thereof include the following structural formulas (38 ′) to (42).

  In the general formulas (1a) to (14a), the number average of the number of repetitions n is 2 or more, preferably 2 or more and 100 or less, and more preferably 2 or more and 20 or less. If n is too small, the film-forming stability is lowered, and if it is too large, the change in solubility is small even when a polymerization reaction is carried out, and lamination may be difficult.

  The number average molecular weight of the polymer or oligomer used in the present invention 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, the film-forming stability tends to be lowered, and if it exceeds 100,000, the change in solubility is small even when a polymerization reaction is carried out, and the lamination tends to be difficult. In addition, 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.

  The polydispersity of the polymer or oligomer used in the present invention 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, the film tends to aggregate after film formation, and if it is too large, the device characteristics tend to deteriorate. The polydispersity of the polymer or oligomer refers to (weight average molecular weight / number average molecular weight) when measured in terms of polystyrene using gel permeation chromatography.

  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, when producing a polymer in which each monomer unit has an aromatic ring and the aromatic rings are bonded to each other, Yamamoto (T. Yamamoto, Bull. Chem. Soc. Jap., 51, No. 7, 2091 (1978)) and Zenbayashi (M. Zembayashi, Tet. Lett., 47: 4089 (1977)) can be used, but Suzuki (A. Suzuki) (Synthetic Communications, Vol. 11, No. 7, p. 513 (1981)) is common for polymer production.

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 together, 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 to 5 mole percent Pd (Ph ₃ P) ₄ , tertiary phosphine ligand, based on aromatic reactants, are generally preferred Pd sources. Furthermore, this reaction also requires a base, with aqueous alkaline carbonates or bicarbonates being most preferred. The reaction can also be promoted in a nonpolar solvent using a phase transfer catalyst. As the nonpolar solvent, N, N-dimethylformamide, toluene, anisole, dimethoxyethane, tetrahydrofuran or the like is used.

  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 not particularly limited as long as it exhibits the ability to polymerize a polymerizable substituent by application of heat, light, microwave, radiation, electron beam, and the like. It is preferably one that initiates polymerization by heating, and more preferably one that initiates polymerization by light irradiation (hereinafter referred to as a photoinitiator).

The photoinitiator is not particularly limited as long as it exhibits the ability to polymerize a polymerizable substituent by irradiation with light of 200 nm to 800 nm. For example, when the polymerizable substituent is an oxetane group. In view of reactivity, iodonium salts, sulfonium salts, and ferrocene derivatives are preferable, and the following compounds (43) to (47) are exemplified.

  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. It is more preferable that the range is 0.5 to 5% by weight. 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 by using the organic electronics material of the present invention, for example, a solution containing the organic electronics material of the present invention is, for example, an ink jet method, a casting method, or an immersion method. Coating on a desired substrate by a known method such as a printing method such as a printing method, letterpress printing, intaglio printing, offset printing, flat plate printing, letterpress reverse printing, screen printing, gravure printing, spin coating, etc. It can be carried out by advancing the polymerization reaction of the polymer or oligomer by heat treatment or the like, and changing (curing) the solubility of 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 there is no limitation, for example, chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene, mesitylene, anisole, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, ethyl cellosolve acetate and the like can be mentioned.

  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 or mixed with other materials and used as a functional material of an organic electronics element. In addition, the organic electronics material of the present invention may be used alone or mixed with other materials to form a hole injection layer, a hole transport layer, an electron block layer, a light emitting layer, a hole block layer, an electron transport of an organic EL element. It can be used as a layer or an electron injection layer.

  When the material for organic electronics of the present invention is used for a light emitting layer of a phosphorescent organic EL device, a metal complex containing a central metal such as Ir or Pt can be added in addition to the polymer or oligomer.

The metal complex containing a central metal such as Ir or Pt to be used is not particularly limited, and examples of the Ir complex include Ir (ppy) ₃ (tris (2-phenylpyridine) iridium) (MA) that emits green light. Baldo et al., Applied Physics Letters, vol.75, p.4 (1999)) or red light emission (btp ₂ ) Ir (acac) (bis (2- (2′-benzo [4,5- α] thienyl) pyridinate-N, C ³ ) iridium (acetyl-acetonate)) (see Adachi et al., Appl. Phys. Lett., 78 no. 11, 2001, 1622), Ir (piq) ₃ (Tris (1 -Phenylisoquinoline) iridium) and the like. Examples of the Pt complex include 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-forphineplatinum (PtOEP) that emits red light. The phosphorescent material can be a small molecule or a dendrid species, such as an iridium nucleus dendrimer. Moreover, these derivatives can also be used conveniently.

  The organic electronics element and the organic EL element of the present invention are not particularly limited as long as the organic electronics element and the organic EL element of the present invention have a layer formed using the organic electronics material of the present invention. In addition, the general structure of organic EL includes, for example, those disclosed in US Pat. No. 4,539,507, US Pat. No. 5,151,629, etc. The organic EL element is disclosed, for example, in International Publication No. 90/13148, European Patent Application No. 04384861, and the like. These organic ELs usually include an electroluminescent layer (light emitting layer) between a cathode (cathode) and an anode (anode) in which at least one of the electrodes is transparent. Furthermore, 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 cases, a 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 the anode material, a metal (eg, Au) or other material having metal conductivity, an oxide (eg, ITO: indium oxide / tin oxide) is used on a transparent substrate (eg, glass or transparent polymer). You can also.

  As described above, the material for organic electronics 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, or the like of an organic electronics element. Are preferably used as a hole injection layer, a hole transport layer, and a light emitting layer, more preferably used as a hole transport layer and a light emitting layer, and most preferably used as a light emitting layer. 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.

  By using the organic electronic material of the present invention, a good quality thin film can be formed. Here, a good quality thin film is a film with high surface smoothness, that is, a thin film with low surface roughness. The surface roughness can be measured by using a high-resolution microscope such as a probe microscope (SPM) or an atomic force microscope (AFM). As a value indicating the surface roughness, for example, arithmetic average roughness (Ra) can be used. The arithmetic average roughness (Ra) is preferably 1.0 nm or less, and more preferably 0.5 nm or less. When the surface smoothness is low, generally, when applied to an organic electronic device, there is a tendency that a short circuit or an increase in resistance value tends to occur, and device characteristics may be deteriorated.

  Examples of the present invention will be described below, but the present invention is not 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、窒素下、７０℃で６時間加熱攪拌した。
室温（２５℃）まで冷却後、水２００ｍＬを加え、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））。 <Synthesis of a monomer having a polymerizable substituent>
(Monomer Synthesis Example 1)

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% sodium hydroxide An aqueous solution (36 g) was added, and the mixture was heated with stirring at 70 ° C. for 6 hours under nitrogen.
After cooling to room temperature (25 ° C.), 200 mL of water was added and extracted with n-hexane. After distilling off the solvent, the residue was purified by silica gel column chromatography and vacuum distillation to obtain 9.51 g of monomer A having a polymerizable substituent as a colorless oil (yield 67 wt%, 1H-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)).

グローブボックス中で、トリス（ジベンジリデンアセトン）ジパラジウム（０）（２５ｍｍｏｌ）、ｔ−ブチルホスフィン（２００ｍｍｏｌ）及びアニソール（６．２５ｍＬ）を混合し、Ｐｄ触媒溶液を調製した。ついで、密閉可能なフッ素樹脂製容器に、２，７−ビス（４，４，５，５−テトラメチル−１，３，２−ジオキサボロラン−２−イル）−９，９−ジオクチルフルオレン（０．４ｍｍｏｌ）、Ｎ−フェニル−３，６−ジブロモカルバゾール（０．３２ｍｍｏｌ）、重合可能な置換基を有するモノマーＡ（０．１６ｍｍｏｌ）及びアニソール（３ｍｌ）、１０重量％水酸化テトラエチルアンモニウム水溶液（８ｍＬ）、上記で調製したＰｄ触媒溶液（１ｍＬ）を入れ、窒素雰囲気下で密閉した。
密閉容器へマイクロ波を照射し、９０℃、１時間加熱撹拌した。反応溶液を抽出、水洗し、メタノール／水混合溶媒（９：１）に注ぎ、析出したポリマーをろ別した。再沈殿を３回繰り返し行って精製し、重合可能な置換基を有し、かつカルバゾール基を有する繰り返し単位を有するオリゴマーＡを得た。なお、得られたオリゴマーの数平均分子量はポリスチレン換算で３５０１、多分散度は１．５２であった。得られたオリゴマーＡのＮＭＲスペクトルを図２に、ＧＰＣクロマトグラムを図３に示す。 <Synthesis of an oligomer having a polymerizable substituent and a repeating unit having a carbazole group>
(Oligomer synthesis example 1)

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. Subsequently, 2,7-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9,9-dioctylfluorene (0. 4 mmol), N-phenyl-3,6-dibromocarbazole (0.32 mmol), monomer A having a polymerizable substituent (0.16 mmol) and anisole (3 ml), 10 wt% tetraethylammonium hydroxide aqueous solution (8 mL) The Pd catalyst solution (1 mL) prepared above was added and sealed under 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 polymer was separated by filtration. The reprecipitation was repeated three times for purification, and an oligomer A having a polymerizable substituent and a repeating unit having a carbazole group was obtained. The oligomer obtained had a number average molecular weight of 3501 in terms of polystyrene and a polydispersity of 1.52. The NMR spectrum of the resulting oligomer A is shown in FIG. 2, and the GPC chromatogram is shown in FIG.

モノマーとして、１，４−ビス（ピナコルボロラン）−２，５−ビス−ヘキシルオキシ−ベンゼン（０．４ｍｍｏｌ）、Ｎ−フェニル−３，６−ジブロモカルバゾール（０．３２ｍｍｏｌ）及び重合可能な置換基を有するモノマーＡ（０．１６ｍｍｏｌ）を用い、オリゴマー合成例１と同様の方法で合成を行い、重合可能な置換基を有し、かつカルバゾール基を有する繰り返し単位を有するオリゴマーＢを得た。なお、得られたオリゴマーの数平均分子量はポリスチレン換算で３２６７、多分散度は１．５０であった。得られたオリゴマーＢのＮＭＲスペクトルを図４に、ＧＰＣクロマトグラムを図５に示す。 (Oligomer synthesis example 2)

As monomers, 1,4-bis (pinacolborolane) -2,5-bis-hexyloxy-benzene (0.4 mmol), N-phenyl-3,6-dibromocarbazole (0.32 mmol) and polymerizable substituents Using monomer A (0.16 mmol), synthesis was performed in the same manner as in oligomer synthesis example 1 to obtain oligomer B having a polymerizable substituent and a repeating unit having a carbazole group. In addition, the number average molecular weight of the obtained oligomer was 3267 in polystyrene conversion, and the polydispersity was 1.50. The NMR spectrum of the resulting oligomer B is shown in FIG. 4, and the GPC chromatogram is shown in FIG.

モノマーとして、４，９−ビス（４，４，５，５−テトラメチル−１，３，２−ジオキサボロラン−２−イル）−１０ｂ−オクチル−１，２，３，１０ｂ−テトラヒドロフルオランテン（０．４ｍｍｏｌ）、Ｎ−フェニル−３，６−ジブロモカルバゾール（０．３２ｍｍｏｌ）及び重合可能な置換基を有するモノマーＡ（０．１６ｍｍｏｌ）を用い、オリゴマー合成例１と同様の方法で合成を行い、重合可能な置換基を有し、かつカルバゾール基を有する繰り返し単位を有するオリゴマーＣを得た。なお、得られたオリゴマーの数平均分子量はポリスチレン換算で３４１４、多分散度は１．５１であった。 (Oligomer synthesis example 3)

As a monomer, 4,9-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -10b-octyl-1,2,3,10b-tetrahydrofluoranthene ( 0.4 mmol), N-phenyl-3,6-dibromocarbazole (0.32 mmol), and monomer A (0.16 mmol) having a polymerizable substituent, and synthesized in the same manner as in oligomer synthesis example 1. Thus, an oligomer C having a polymerizable substituent and a repeating unit having a carbazole group was obtained. In addition, the number average molecular weight of the obtained oligomer was 3414 in polystyrene conversion, and the polydispersity was 1.51.

モノマーとして、１，４−ビス（ピナコルボレート）−２，５−ジシクロヘキシルベンゼン（０．４ｍｍｏｌ）、Ｎ−フェニル−３，６−ジブロモカルバゾール（０．３２ｍｍｏｌ）及び重合可能な置換基を有するモノマーＡ（０．１６ｍｍｏｌ）を用い、オリゴマー合成例１と同様の方法で合成を行い、重合可能な置換基を有し、かつカルバゾール基を有する繰り返し単位を有するオリゴマーＤを得た。なお、得られたオリゴマーの数平均分子量はポリスチレン換算で２２２８、多分散度は１．３７であった。 (Oligomer synthesis example 4)

Monomers having 1,4-bis (pinacorborate) -2,5-dicyclohexylbenzene (0.4 mmol), N-phenyl-3,6-dibromocarbazole (0.32 mmol) and polymerizable substituents as monomers Using A (0.16 mmol), synthesis was performed in the same manner as in oligomer synthesis example 1 to obtain an oligomer D having a polymerizable substituent and having a repeating unit having a carbazole group. In addition, the number average molecular weight of the obtained oligomer was 2228 in polystyrene conversion, and the polydispersity was 1.37.

<Production of organic EL element>
Example 1 Application Example as Light-Emitting Layer
On a glass substrate on which ITO (Indium Tin Oxide) is patterned to a width of 1.6 mm, a PEDOT: PSS dispersion (Stark Vitech, CH8000 LVW233) is spin-coated at 4000 rpm, and 200 ° C. in air on a hot plate. / 10 minutes by heating to form a hole injection layer (thickness 40 nm). The subsequent steps were performed in a dry nitrogen environment.
Next, a coating solution in which the oligomer A (20 mg), (btp ₂ ) Ir (acac) (0.6 mg) and anisole (1 ml) obtained above were mixed on the hole injection layer was spun at 2000 min ⁻¹ . After coating, it was dried by heating at 80 ° C. for 15 minutes on a hot plate to form a light emitting layer (thickness 80 nm).
Furthermore, the glass substrate obtained above was transferred into a vacuum deposition machine, and Ba (film thickness: 3 nm) and Al (film thickness: 100 nm) were deposited in this order on the light emitting layer to form electrodes.
After electrode formation, the substrate is moved into a dry nitrogen environment without opening to the atmosphere, and the sealing glass and ITO substrate in which 0.4 mm of counterbore is added to 0.7 mm non-alkali glass are coated with a photocurable epoxy resin. The organic EL element was produced by sealing by using and bonding. The subsequent steps were performed in the atmosphere at room temperature (25 ° C.).
When a voltage was applied using ITO as an anode and Al as a cathode of this organic EL element, uniform red light emission was observed at about 8V.

(Comparative Example 1)
An EL device was produced in the same manner as in Example 1 except that CBP was used instead of the oligomer A. However, many dark spots were generated, and uniform light emission could not be obtained.

で表される光開始剤（０．１３ｍｇ）、トルエン（０．７５ｍｌ）を混合した塗布溶液を、３０００ｒｐｍで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、正孔輸送層（２０ｎｍ）を形成した。
次いで、得られたガラス基板を真空蒸着機中に移し、ＣＢＰとＩｒ（ｐｉｑ）_３の共蒸着膜（４０ｎｍ）、ＢＡｌｑ（５ｎｍ）、Ａｌｑ_３（３０ｎｍ）、ＬｉＦ（０．５ｎｍ）、Ａｌ（１００ｎｍ）の順に蒸着し、窒素環境中で封止を行った。
この有機ＥＬ素子のＩＴＯを陽極、Ａｌを陰極として電圧を印加したところ、約５Ｖで赤色発光が観測され、輝度１０００ｃｄ／ｍ^２における電流効率は５．２ｃｄ／Ａであった。
また、寿命特性として、０．７ｍＡの定電流を印加しながらトプコン社製ＢＭ−７で輝度を測定し、輝度が初期輝度（１４００ｃｄ／ｍ^２）から半減する時間を測定したところ、６０時間であった。 Example 2 Application Example as Hole Transport Layer
In the same manner as in Example 1, a hole injection layer (40 nm) was formed using a PEDOT: PSS dispersion. The subsequent steps were performed in a dry nitrogen environment.
Next, the oligomer A (3.1 mg) obtained above on the hole injection layer, the following chemical formula

A coating solution in which a photoinitiator represented by the formula (0.13 mg) and toluene (0.75 ml) are mixed is spin-coated at 3000 rpm, and then irradiated with light using a metal halide lamp (3 J / cm ² ) to form a hot plate. The above was heated and cured at 180 ° C. for 60 minutes to form a hole transport layer (20 nm).
Next, the obtained glass substrate was transferred into a vacuum deposition machine, and a co-deposited film of CBP and Ir (piq) ₃ (40 nm), BAlq (5 nm), Alq ₃ (30 nm), LiF (0.5 nm), Al ( 100 nm) in order and sealed in a nitrogen environment.
When voltage was applied using ITO as an anode and Al as a cathode of this organic EL element, red light emission was observed at about 5 V, and the current efficiency at a luminance of 1000 cd / m ² was 5.2 cd / A.
Moreover, as a lifetime characteristic, the luminance was measured with Topcon BM-7 while applying a constant current of 0.7 mA, and the time when the luminance was reduced to half from the initial luminance (1400 cd / m ² ) was measured. there were.

(Comparative Example 2)
An organic EL device was produced in the same manner as in Example 2 except that the hole transport layer containing the oligomer A was not formed. When a voltage was applied to this organic EL element, red light emission was observed at about 6 V, the current efficiency at a luminance of 1000 cd / m ² was 4.0 cd / A, and Example 2 was 1.3 times that of Comparative Example 2. Efficiency was obtained. Further, when the lifetime characteristics were measured, the luminance was reduced by half in 5 hours. In Example 2, the lifetime was 12 times that of Comparative Example 2.

Example 3 Application Example as Hole Transport Layer and Light-Emitting Layer
In the same manner as in Example 1, a hole injection layer (40 nm) was formed using a PEDOT: PSS dispersion, and subsequently, a hole transport layer containing oligomer A was formed in the same manner as in Example 2.
Further, a coating solution in which oligomer A (10 mg), Ir (piq) ₃ (0.5 mg) and anisole (0.7 ml) were mixed was spin-coated at 2000 rpm, and then heated on a hot plate at 80 ° C. for 5 minutes. And dried to form a light emitting layer (40 nm). The hole transport layer and the light emitting layer could be formed without crossing each other.
Next, the obtained glass substrate was transferred into a vacuum deposition machine, and BAlq (5 nm), Alq ₃ (30 nm), LiF (0.5 nm), and Al (100 nm) were deposited in this order, and sealed in a nitrogen environment. It was.
When voltage was applied using ITO as the anode and Al as the cathode of this organic EL element, red light emission was observed at about 6 V, and the current efficiency at a luminance of 1000 cd / m ² was 4.5 cd / A.

<Evaluation of film quality>
(Example 4)
A toluene solution of oligomer A was spin-coated on a quartz substrate and dried by heating at 80 ° C. for 5 minutes on a hot plate to prepare a thin film having a thickness of 40 nm. Using a probe microscope (Nanopics NPX-100, manufactured by Seiko Instruments Inc.), the surface shape of this thin film was observed in a 4 μm × 4 μm range in a damping mode. When arithmetic mean roughness (Ra) was calculated | required from the obtained image, it was 0.2 nm.

(Comparative Example 3)
A thin film was produced in the same manner as in Example 4 using a CBP toluene solution. The arithmetic average roughness (Ra) was 1.2 nm, which was 6 times that of Example 4.

It is the schematic which shows an example of the multilayered organic EL element. It is a graph which shows the NMR spectrum of the obtained oligomer A. It is a graph which shows the GPC chromatogram of the obtained oligomer A. It is a graph which shows the NMR spectrum of the obtained oligomer B. It is a graph which shows the GPC chromatogram of the obtained oligomer B.

Explanation of symbols

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

Claims (10)

An organic electronics material comprising a polymer or oligomer having one or more polymerizable substituents and a unit having a carbazole group,
The polymer or oligomer has a structure represented by any of the following general formulas (1a) to (6a) ,
The number average molecular weight of the polymer or oligomer is 1,000 or more and 100,000 or less,
A material for organic electronics, wherein the polymerizable substituent contains an oxetane group .

(Wherein, R, ^-R 1 each ^{independently, -OR 2, -SR 3, -OCOR} 4, -COOR 5, -SiR 6 R 7 R 8, or the following general formula (15a) ~ (17a) 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 represent represent.) an integer of 1 or more, a r represents a substituted or unsubstituted arylene group and / or a heteroarylene group, E is a group containing a polymerizable substituent N represents an integer of 2 or more. ) The organic electronics material according to claim 1 , wherein the polydispersity of the polymer or oligomer is greater than 1.0. The organic electronics material according to claim 1 or 2 , wherein a number average of n in the general formulas (1a) to (6a) is 2 to 20. Furthermore, the material for organic electronics in any one of Claims 1-3 containing an iridium complex or a platinum complex. Furthermore, the material for organic electronics in any one of Claims 1-4 containing a polymerization initiator. The organic electronics element produced using the material for organic electronics in any one of Claims 1-5 . The organic electroluminescent element produced using the material for organic electronics in any one of Claims 1-5 . 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 of the organic electronics material according to any one of claims 1 to 5. Sense element. It is an organic electroluminescent element formed by laminating at least an anode, a hole transport layer, a light emitting layer, and a cathode, and the hole transport layer is formed of the organic electronics material according to any one of claims 1 to 5. An organic electroluminescence device which is a layer. It is an organic electroluminescent element formed by laminating at least an anode, a hole injection layer, a light emitting layer, and a cathode, and the hole injection layer is formed of the organic electronics material according to any one of claims 1 to 5. An organic electroluminescence device which is a layer.

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